JPH10101977A - Ink jet recording ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording ink excellent in storage stability, water resistance and antimold properties. SOLUTION: This ink essentially consists of a colorant, a water-soluble organic solvent, water, 0.01-5.0wt.%, based on the total weight of the ink, acetylene glycol/alkylene oxide adduct represented by the formula (wherein R1 to R4 are each a lower alkyl; l is an integer of 2 or 3; and m and n are each an integer of 1 or greater), and 2-8wt.%, based on the total weight of the ink, polyethyleneimine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink used in an ink jet recording type printer.

[0002]

2. Description of the Related Art In general, inks used in ink jet recording type printers are known in which various coloring materials are dissolved or dispersed in water or a medium comprising water and various organic solvents. In order to reproduce a color image, inks of each color of yellow, cyan, magenta, and black have been put to practical use.

[0003] Ink jet recording inks are required to be excellent in defoaming properties, because bubbles are generated in the ink flow path in the recording head, resulting in missing dots in the recorded image. In order to provide an ink having excellent defoaming properties, for example, JP-A-6-256696 proposes to use an acetylene glycol-based surfactant.

[0004] However, the ink described in the above publication is
It does not achieve the property of high storage stability required for ink jet recording inks, especially storage stability against sudden temperature changes. In addition, the mold resistance of the ink itself is poor,
Also, the water resistance of the printed image is inferior.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording ink having a high storage stability, which is excellent in antifungal property and water resistance of a printed image.

[0006]

The present invention relates to an ink containing at least a coloring material, a water-soluble organic solvent and water, wherein the ink has the formula (A):

[0007]

Embedded image

Wherein R _{1 to} R ₄ are lower alkyl groups, l is an integer of 2 or 3, and m and n are integers of 1 or more.
The present invention provides an inkjet recording ink containing 0.01 to 5.0% by weight of an alkylene oxide adduct of acetylene glycol represented by the formula (1) and 2 to 8% by weight of polyethyleneimine.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Coloring materials used in the ink of the present invention include acid dyes, direct dyes, basic dyes, reactive dyes, and the like.
Food dyes, disperse dyes, oil-soluble dyes, vat dyes, various pigments and the like can be used, and among them, water-soluble dyes are preferable. The content of the colorant in the ink composition is determined by the type of the colorant and the ink medium component, the characteristics required for the ink, and the like, but is generally 0.5 to 10% by weight, preferably 2 to 6% by weight in the ink. It is contained in the range of weight%.

The ink for ink jet recording needs to adjust the surface tension of the ink to a certain range in order to suppress the bleeding of the ink and to stabilize the nozzle dischargeability of the ink jet recording apparatus. Usually, a surfactant is added to the ink. In the present invention, the surface tension of the ink is reduced by adding an alkylene oxide adduct of acetylene glycol represented by the above formula (A) as a surfactant to the ink. ~ 50 dyn / cm (25
℃). Since the surfactant of the formula (A) hardly changes due to the temperature of the compound itself, the use of the surfactant improves the stability of the surface tension and the viscosity with respect to the temperature change of the ink.

In the formula (A), R ₁ and R ₂ are the same lower alkyl group having 1 to 5 carbon atoms, preferably 2 carbon atoms.
And 4 lower alkyl groups, particularly preferably an isobutyl group. R ₃ and R ₄ are the same lower alkyl group having 1 to 5 carbon atoms, preferably a methyl group. As the alkylene oxide to be added, ethylene oxide and propylene oxide are preferable. Particularly preferred is ethylene oxide. m and n may be the same or different, and m + n is 2 to 60, preferably 2 to 30, and more preferably 6 to 20.

As the alkylene oxide adduct of acetylene glycol, a commercially available product of formula (A) wherein R ₁ = R ₂ = isobutyl, R ₃ = R ₄ = methyl and l = 2, Olfin E1004 (m + n = 3.5) ) (Manufactured by Nissin Chemical Industry Co., Ltd.), Olfin E1010 (m + n = 10) (manufactured by Nissin Chemical Industry Co., Ltd.) and Surfynol 485 (m + n = 3)
0) (manufactured by AIR PRODUCTS, USA) are known, and any of them is suitably used for the ink of the present invention.

The ink of the present invention contains 0.01 to 5% by weight of an alkylene oxide adduct of acetylene glycol,
Preferably from 0.1 to 5% by weight, more preferably from 0.1 to 2% by weight.
It is contained in the range of weight%. If it is less than 0.01%, the effect of enhancing the stability by the addition becomes insufficient, and 5%
If the amount is larger, the stability of the ink against a change in temperature is lowered, which is not preferable.

[0014] The ink of the present invention contains polyethyleneimine. By the addition of polyethyleneimine, it has become possible to achieve storage stability against a rapid temperature change, water resistance of a printed image, and even higher antifungal property, which cannot be obtained with conventional inks.

Polyethyleneimine is a linear polymer represented by the following formula:-[CH ₂ CH ₂ NH]-, but may have a branch containing a primary, secondary, or tertiary amino nitrogen. Good. Usually, commercially available polyethyleneimine is a compound having a branch in the polymerization of ethyleneimine.
Polyethyleneimine having a molecular weight of 200 to 10,000, particularly 250 to 2,000 is preferably used.

By adding polyethyleneimine, it is possible to adjust the viscosity to a level suitable for ink jet recording, ink jetting and supply, and fixability to recording paper without impairing the coloration of the ink or the properties of the ink alone. Becomes Further, unlike polyethylene glycol which is conventionally used as a thickener, it also has a chelating action and an antibacterial action, so that polyethyleneimine also contributes to the chemical and thermal stability of the ink.

The content of polyethyleneimine is 2 to 8% by weight, preferably 3 to 7% by weight based on the total weight of the ink of the present invention. If the amount of polyethyleneimine is less than 2% by weight, the effect of the present invention cannot be obtained. If the amount of polyethyleneimine exceeds 8% by weight, the viscosity of the ink becomes too high, and the ink responsiveness and replenishability are lowered, and fixing is performed. It is not preferable because the speed is reduced.

The water-soluble organic solvent used in the ink of the present invention is preferably a polyhydric alcohol having 3 hydroxyl groups, wherein OH (CxH _2x O) _y H (where x and y are 2 ≦ x and 2 ≦ x (Indicating an integer satisfying × y ≦ 6), a (mono, di, tri) alkylene glycol, a lower alkyl ether of the (mono, di, tri) alkylene glycol and a mixture thereof. Including. Glycerin is illustrated as a polyhydric alcohol having 3 hydroxyl groups.

As the (mono, di, tri) alkylene glycol, ethylene glycol, propylene glycol,
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 are exemplified. When a polyhydric alcohol is used as the water-soluble organic solvent, it is preferably added in an amount of 1 to 20% by weight, preferably 6 to 14% by weight, based on the total amount of the ink.
When a (mono, di, tri) alkylene glycol is used, it is preferably added in an amount of 1 to 30% by weight, preferably 6 to 14% by weight, based on the total weight of the ink.

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 lower alkyl ether of (mono, di, tri) alkylene glycol is contained, the content is preferably 1 to 30% by weight, especially 4 to 10% by weight based on the total weight of the ink.

By adding the above-mentioned polyhydric alcohol, (mono, di, tri) alkylene glycol, lower alkyl ether of (mono, di, tri) alkylene glycol and polyalkylene glycol, the moisturizing property of the ink is improved. It is also useful for stabilizing viscosity and surface tension. The total amount of the polyhydric alcohol, the (mono, di, tri) alkylene glycol, the lower alkyl ether of the (mono, di, tri) alkylene glycol and the polyalkylene glycol is from 10 to the total weight of the ink.
It is added in an amount of 30% by weight, preferably 13 to 25% by weight. If the addition amount is less than 10% by weight, the above effect cannot be achieved. If the addition amount exceeds 30% by weight, the viscosity of the ink becomes too high, the ink flying response and the replenishing property decrease, and the fixing speed also decreases. It is not preferable because it becomes slow.

The ink of the present invention preferably contains an aliphatic alcohol. As the aliphatic alcohol, an alkyl alcohol having 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, and isopropyl alcohol, is used. Aliphatic alcohol accounts for 0.1 to 15 of the total weight of the ink.
% By weight, more preferably 1 to 6% by weight. The addition of the aliphatic alcohol improves the drying property of the ink and improves the fixing property of the ink. However, this effect cannot be obtained if the addition amount is small, and if the addition amount exceeds 15% by weight, clogging of the nozzle and the like may occur. This is not preferable because inconvenience is likely to occur.

The ink of the present invention preferably contains an amphiphile. Examples of the amphiphilic substance include urea, amide, cyclic amide, and alkanolamine, and alkanolamine such as triethanolamine is particularly preferable. The amphiphile is used in an amount of 0.01 to 0.01% based on the total weight of the ink.
The content is 5% by weight, preferably 0.1 to 2% by weight. By adding an amphiphilic substance to the ink, the precipitation of crystals with the lapse of time is prevented and the stability of the ink is increased. However, if the amount is less than 0.01% by weight, the effect cannot be obtained. % Is not preferable because bleeding increases.

The ink of the present invention comprises NaOH and NaHCO
₃ and Na ₂ B ₄ O _{7 in} a mixture with at least one compound selected from the group consisting of
The content is preferably from 01 to 2% by weight, particularly preferably from 0.05 to 1% by weight. The weight ratio of NaOH to NaHCO ₃ and the like in the mixture is 1: 2 to 1:50, preferably 1: 5 to 1:30
It is preferable to adjust to. By adding these mixtures, high storage stability against a sudden temperature change and stability against a temperature change within an actual use temperature are improved, and nozzle clogging is also eliminated. Also, variation in dot diameter is suppressed.

It is preferable to add an alkali metal salt of ethylenediamine to the ink of the present invention. Sodium, as an alkali metal that forms a salt with ethylenediamine,
Potassium and the like are exemplified, but a sodium salt is preferred. As the alkali metal salt of ethylenediaminetetraacetic acid suitably used in the present invention, disodium salt,
Examples thereof include a trisodium salt and a tetrasodium salt, and a tetrasodium salt is particularly preferable. The addition of ethylenediaminetetraacetate prevents clogging of the nozzle discharge port, and improves the stability of the ink in the ink head in a high-temperature, high-humidity environment. Ethylenediaminetetraacetate is contained at 0.01 to 2% by weight, preferably 0.05 to 1% by weight, based on the total weight of the ink. 0.01
If the amount is less than 2% by weight, the effect of the addition cannot be obtained, and if the amount exceeds 2% by weight, the stability of the ink is adversely affected.

The ink of the present invention may contain known additives as necessary in addition to the above-mentioned components. Examples of the additive include an antifungal agent, a preservative, a pH regulator, a chelating agent, an oxygen absorber, a rust inhibitor, a quencher and the like. The ink of the present invention contains 60 to 90% by weight of water, more preferably 70 to 9% by weight.
It contains 0% by weight.

The ink-jet recording ink of the present invention comprises:
Any type of ink jet recording type printer can be applied. Since the ink of the present invention has a very low temperature dependency of viscosity and surface tension, it is particularly suitable for an ink jet recording apparatus using a piezo method in which a flying voltage is changed to change a diameter of an ink to be ejected to reproduce gradation. It can be suitably used.

Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.

EXAMPLES The components of the following Examples and Comparative Examples were mixed and dissolved with sufficient stirring. After the obtained mixture was filtered, the mixture was allowed to stand for 1 hour in a vacuum state to remove bubbles, thereby preparing an ink. The olphin used in the following Examples
E1010 (manufactured by Nissin Chemical Industry Co., Ltd.)
₁ = R ₂ = isobutyl, R ₃ = R ₄ = methyl, l = 2, m +
It is a compound where n = 10.

Example 1 Composition Composition ratio (% by weight) Water 78.4 Diethylene glycol 10.0 Polyethyleneimine: Epomin SP-006 (Molecular weight 600, manufactured by Nippon Shokubai Co., Ltd.) 4.5 C.I. I. 27755 (black dye) 4.6 Olfin-E1010 (Nissin Chemical Industry Co., Ltd.) 0.8 N (CH ₂ CH ₂ OH) ₃ 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 EDTA4Na 0.2 1 , 2-Benzoisothiazolin-3-one (fungicide) 0.1 Ethyl alcohol / isopropyl alcohol (1: 1) 1.0

Example 2 Composition Composition ratio (% by weight) Water 80.7 Triethylene glycol butyl ether 6.5 Polyethyleneimine (Epomin SP-006) 7.6 C.I. I. 27755 (black dye) 4.3 Olfin-E1004 (manufactured by Nissin Chemical Industry Co., Ltd.) 0.1 N (CH ₂ CH ₂ OH) ₃ 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 EDTA4Na 0.3 1,2-benzisothiazolin-3-one 0.1

Example 3 Composition Composition ratio (% by weight) Water 72.8 Diethylene glycol 12.2 Polyethyleneimine (Epomin SP-006) 2.0 C.I. I. 27755 (black dye) 5.5 Orfin-E1010 (Nissin Chemical Industry) 4.5 N (CH ₂ CH ₂ OH) ₃ 0.9 Na ₂ B ₄ O ₇ / NaOH (19: 1) 0.2 EDTA4Na 1 .8 1,2-Benzoisothiazolin-3-one 0.1

Example 4 Composition Composition ratio (% by weight) Water 73.8 Diethylene glycol 7.0 Triethylene glycol polyethylene ether 7.0 Polyethylene imine (Epomin SP-006) 4.5 C.I. I. 19140 (yellow dye) 2.6 Orfin-E1010 (Nissin Chemical Industry) 2.8 N (CH ₂ CH ₂ OH) ₃ 1.8 NaHCO ₃ / NaOH (19: 1) 0.2 EDTA4Na 0.2 1, 2-benzoisothiazolin-3-one 0.1

Example 5 Composition Composition ratio (% by weight) Water 83.0 Diethylene glycol 6.2 Polyethyleneimine (Epomin SP-006) 4.3 C.I. I. 45100 (magenta dye) 2.5 Orfin-E1010 (Nissin Chemical Industry) 1.2 N (CH ₂ CH ₂ OH) ₃ 0.2 NaHCO ₃ / NaOH (19: 1) 0.2 EDTA4Na 0.5 1, 2-Benzoisothiazolin-3-one 0.1 Ethanol / isopropyl alcohol (1: 1) 1.8

Example 6 Composition Composition ratio (% by weight) Water 84.8 Triethylene glycol methyl ether 6.5 Polyethylene imine (Epomin SP-006) 4.2 C.I. I. 74180 (cyan dye) 3.0 Olfin-E1010 (Nissin Chemical Industry) 0.8 N (CH ₂ CH ₂ OH) ₃ 0.2 Na ₂ B ₄ O ₇ / NaOH (19: 1) 0.2 EDTA 4Na 0.2 1,2-benzisothiazolin-3-one 0.1

Example 7 Composition Composition ratio (% by weight) Water 78.7 Diethylene glycol 10.0 Polyethyleneimine (Epomin SP-006) 4.5 C.I. I. 27755 (black dye) 4.5 Orfin-E1010 (Nissin Chemical Co., Ltd.) 0.8 N (CH ₂ CH ₂ OH) ₃ 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.21, 2-Benzoisothiazolin-3-one 0.1 Ethyl alcohol 1.0

Example 8 Composition Composition ratio (% by weight) Water 78.8 Glycerin 10.0 Polyethyleneimine (Epomin SP-006) 4.5 C.I. I. 27755 (black dye) 4.5 Orfin-E1010 (Nissin Chemical Industry Co., Ltd.) 0.8 N (CH ₂ CH ₂ OH) ₃ 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.2 ethyl alcohol 1.0

Example 9 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.) 4.0 Water solubility Dye C.I. I. 45100 (red dye) 2.5 Surfactant “Olfin-E1010” (manufactured by Nissin Chemical Industry Co., Ltd.) 0.8 triethanolamine 0.2 NaB ₄ O ₇ / NaOH (19: 1) 0.2 ethylenediaminetetraacetic acid Tetrasodium 1.7 1,2-benzisothiazolin-3-one 0.1 Ethanol 1.5

Comparative Example 1 Composition Composition ratio (% by weight) Water 79.5 Diethylene glycol 10.0 Polyethyleneimine (Epomin SP-006) 4.5 C.I. I. 27755 (black dye) 4.5 N (CH ₂ CH ₂ OH) ₃ 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.2 1,2-benzisothiazolin-3-one 0.1 ethyl alcohol 1.0

Comparative Example 2 Composition Composition ratio (% by weight) Water 74.0 Diethylene glycol 10.0 Polyethyleneimine (MW600) 4.5 C.I. I. 27755 (black dye) 4.5 Orfin-E1010 (Nissin Chemical Industry Co., Ltd.) 5.5 N (CH ₂ CH ₂ OH) ₃ 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.21, 2-Benzoisothiazolin-3-one 0.1 Ethyl alcohol 1.0

Comparative Example 3 Composition Composition ratio (% by weight) Water 84.2 Diethylene glycol 10.0 C.I. I. 27755 (black dye) 4.5 Orfin-E1010 (Nissin Chemical Industry Co., Ltd.) 0.8 N (CH ₂ CH ₂ OH) ₃ 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.21, 2-Benzoisothiazolin-3-one 0.1 Ethyl alcohol 1.0

Comparative Example 4 Composition Composition ratio (% by weight) Water 74.7 Diethylene glycol 10.0 Polyethyleneimine (Epomin SP-006) 8.5 C.I. I. 27755 (black dye) 4.5 Orfin-E1010 (Nissin Chemical Co., Ltd.) 0.8 N (CH ₂ CH ₂ OH) ₃ 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.21, 2-Benzoisothiazolin-3-one 0.1 Ethyl alcohol 1.0

Comparative Example 5 Composition Composition ratio (% by weight) Water 83.3 Diethylene glycol 10.0 C.I. I. 27755 (black dye) 4.5 Orfin-E1010 (Nissin Chemical Industry Co., Ltd.) 0.8 N (CH ₂ CH ₂ OH) ₃ 0.2 Ca (OH) ₂ / NaOH (19: 1) 0.2 ethanol 1 .0

25 of the inks of the obtained Examples and Comparative Examples
The surface tension at ℃, viscosity and pH, storage stability against thermal shock, and temperature dependence of surface tension and viscosity were examined. The mold resistance test of the ink and the water resistance of the obtained printed matter were examined. The measuring method is as follows:

1) Preservation property against thermal shock The thermal shock in which the ink stored at 25 ° C. in a polyethylene bottle is held at -20 ° C. and 50 ° C. for 1 hour each, is applied three times a day. The feeding was repeated for one week. Before and after that, the viscosity (25 ° C.) was measured, 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) Temperature Dependence The rate of change in surface tension and viscosity at ink temperatures of 10 ° C. and 35 ° C. was measured. Change rate 1)
It was ranked the same as.

3) Water resistance test Epson inkjet printer (MJ-500)
Was used.

The inks of Examples and Comparative Examples were filled in the ink cartridges of the above-described printers, and printed on Epson SF paper to check the water resistance. A one-color solid surface of an area of 5 × 5 mm was printed and air-dried for 24 hours. After measuring the density of the printing surface with a Sakura densitometer PDA65, the printed surface was immersed in pure water for 10 minutes, taken out, and air-dried. The color density was measured, and the difference in density before and after immersion in pure water was ranked in the same manner as in 1). 4) Mold prevention test Evaluated according to the following procedure using bacteria specified in JIS Z 2911 (mold resistance test method). 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. In addition, in the evaluation of each of the above tests, “△” indicates “no problem in practical use”.
This is limited to the case of binary printing, and may be inconvenient in practical use when gradation printing is performed by reducing the dot diameter or changing the dot diameter. Table 1 shows the results.

[0048]

[Table 1]

[0049]

According to the present invention, the ink of the present invention is
High storage stability against sudden temperature changes, high water resistance of printed images, and high antifungal effect.

Continued on the front page (72) Inventor Masami Asano 2-3-1-3 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Hideo Hotomi 2-chome, Azuchi-cho, Chuo-ku, Osaka-shi, Osaka No. 13 Osaka International Building Minolta Co., Ltd.

Claims (6)

[Claims] 1. An ink containing at least a coloring material, a water-soluble organic solvent and water, wherein the ink has the formula (A): (Wherein, R _{1 to} R ₄ are lower alkyl groups, l is an integer of 2 or 3, m and n are each an integer of 1 or more), and the alkylene oxide adduct of acetylene glycol represented by 0.01 to 5.0. 0% by weight and polyethyleneimine
An ink jet recording ink containing 8% by weight. 2. Polyethyleneimine having a molecular weight of 200 to 200.
2. 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, a formula: HO (C _x H _2x O) _y H (where x and y are 2 ≦ x and 2 ≦ x × y ≦ 6) Wherein the compound is selected from the group consisting of (mono, di, tri) alkylene glycols, lower alkyl ethers of the (mono, di, tri) alkylene glycols, and mixtures thereof. 3. The ink jet recording ink according to 1 or 2. 4. The total content of polyhydric alcohol, (mono, di, tri) alkylene glycol, (mono, di, tri) alkylene glycol lower alkyl ether and polyethyleneimine is 10 to 30% by weight based on the total weight of the ink.
The ink for inkjet recording according to claim 3, which is: 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 the alkanolamine based on the total weight of the ink.