JPS6286069A - Water-based ink composition - Google Patents

Abstract

PURPOSE:To obtain a black water-based ink which has excellent discharge characteristics, being free of clogging and gives a printed image with excellent definition, water resistance, and light resistance, by using a water-soluble dye comprising a specified tetraazo compound. CONSTITUTION:A water-based ink composition containing a water-soluble dye of formula I, wherein R1 is H, alkyl, alkoxy, halogen or sulfo group; R2 is H, alkyl, alkoxy or halogen; R3 and R4 are each H, amino, nitro, halogen, alkyl, carboxyl, carbamoyl, sulfamoyl, cyano or sulfo group; M is a cation of, e.g., H, Na, K, Li or an organic amine; n is 1 or 2. Examples of compounds of formula I include those of formulas II, III, and IV. The content of the dye of formula I is 0.5-20pts.wt., preferably 1.5-6pts.wt., based on 100pts.wt. ink.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a water-based ink composition suitable for printing, writing instruments, recorders, and scumbu, and particularly Infusiera 1 to black light blue having excellent performance for printing. The present invention relates to an ink composition.

In conventional inkjet recording, in order to perform good recording at υ for a long time, the ink used must meet the following conditions]1
It is necessary to satisfy the following.

1) The viscosity, surface tension, specific conductivity, and density of the ink should be within appropriate ranges as physical properties of the ink according to the droplet generation method and the droplet flying direction control method.

2) Precipitation should not occur due to chemical changes or changes in the physical properties of the ink during use, during use, or during recording.

3) The recorded image has a sufficiently high contrast l~ and is clear.

4) The printed image dries quickly.

In order to meet the above requirements, it is required that the molecular extinction coefficient of the dye used in the ink is sufficiently high, and that the solubility of the dye in water and a wetting agent is sufficiently high.

Furthermore, the ink used in full-color printers, etc. must 5) exhibit a color tone with excellent purity, and 6) the recorded image must be clear, without smearing, with excellent water resistance, light resistance, and abrasion resistance. It is required that it must be.

To date, many proposals have been made for inkjet recording inks to meet the above requirements.
At present, no material has yet been obtained that satisfactorily satisfies all of the above conditions.

The properties required above are particularly influenced by the dye among the materials used in the ink, and in order to satisfy these requirements, a new dye (F11) has been awaited.

Normally, water-based ink compositions basically consist of a dye, a polyhydric alcohol or its ether known as a wetting agent, and water, and may optionally contain additives such as antifungal agents. It is.

In conventional black water-based ink, dyes include c, r, direct black -4, -17, -19, -32, -3.
8, -51, -75, -112, -154 etc. and C1■,
Acid Black -1, -2, zu, ~24, -28, -
There are direct dyes such as 94 and acid dyes.

However, among these dyes, direct dyes have poor solubility, so it is not possible to sufficiently increase image density and contrast by increasing their content.

Furthermore, although acidic dyes have good solubility, the water resistance of images is particularly poor, so special treated paper must be used.

Purpose The present invention provides an aqueous ink composition that solves the above-mentioned conventional drawbacks, and more specifically, has excellent jetting properties, is free from clogging, and has particularly good image clarity, water resistance, and light resistance. This provides an excellent black water-based ink.

Structure The present inventor has discovered that the use of a specific dye as a means to solve the above-mentioned drawbacks brings about sufficient effects, and has thus arrived at the present invention. In other words, the ink composition of the present invention is characterized by containing at least one water-soluble dye represented by the following general formula.

R1; hydrogen, alkyl group, alkoxy group, halogen, sulfone l! ! Base R2: hydrogen, Arnyal group, alkoxy group, halogen R3, R4: hydrogen, AmimuL nitro group, sulfonic acid group,
Halogen, alkyl group, carboxyl group, carbamoyl group, sulfamoyl group, cyano group M; indicates a cation such as hydrogen, sodium, potassium, lithium, or organic amine.

n=1 or 2゜The content of the dye represented by the above general formula is 10 in the ink.
0.5 to 20 parts by weight, preferably 1.5 parts by weight per 1 part
~6 parts by weight is suitable. If it is less than 0.5 parts by weight, its effectiveness as a coloring agent will be weakened, and the color tone of the image produced by 1q will be insufficient, and if it exceeds 20 parts by weight, precipitation will occur in the ink if left for a long time. Infusiella [-
There is a tendency for insufficient recording to be carried out.

Furthermore, in order to make the color tone more pure black, other red dyes or yellow dyes can be used together with the dye of the present invention. Red dyes that can be used in combination include C, 1, Direct Red-1, -9, -11, -37, -62, -75, -
83, -99, -220, -227 and C, 1,7 side drop 87, -92, -94, -115, -131,
-154, -186, -254, etc., but yellow dyes include C,
1, Direct Yellow -12, -27, -28, -3
3, -39, -44, -50, -5&, -85, -86
, -87, -88, -100, -110, -142, -
144, c, r, acid yellow 4, -17, -23
, -29, -42, -99, etc.

Specific examples of the dye are listed below.

Naυ) 2) U3Na: Vau, 2) Go1 no 11-1
．． 1 These dyes can be easily synthesized.

For example, the dye shown in specific example (1) is prepared by adding ol 1 to aminohen/dit-IJ JL/2.40 to water GOml, l
Dissolved in 7 ml of U acid, 1.5 liters of sodium lil'I acid.
Diazotized with 9)-1 acid 7.2jJ, water 200
Add to the m1 solution. Adjust the pH to 3 with sodium acetate to 10
C. for 8 hours to prepare a monoazo dye solution. Next 4.
2.39 4'-diaminobenzanilide in 100ml of water
, dissolved in 7 ml of hydrochloric acid, tetrazotized with 1.5 g of sodium nitrite, added to a monoazo dye solution made alkaline with sodium carbonate at 5°C, and reacted for 1 hour. After completion, the dye was precipitated by diluting with common salt. Yield 1io, eg (yield 88
%〉.

The ink of the present invention uses water as a solvent component, and water is used for purposes such as adjusting the physical properties of the ink to desired values, preventing drying of the ink, and improving the solubility of dyes. It is also possible to use a mixture of the following water-soluble organic solvents and water.

Ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polyhydric alcohols such as glycerin, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoether, diethylene glycol monobutyl ether, triethylene glycol Alkyl ethers of polyalcohols such as ethylene glycol monomethyl ether, triethylene glycol monoethyl ether, etc., N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, dimethylformamide, Ethanolamine, etc.

Among these, particularly preferred are diethylene glycol,
These are polyethylene glycol 200-600, triethylene glycol, ethylene glycol, glycerin, and N-methyl-2-pyrrolidone, and by using these, it is possible to obtain high dye solubility and the effect of preventing clogging by preventing water evaporation. .

The content m of the above-mentioned water-soluble organic solvent in the ink is
It can be used in the range of 5 to 80% of f1, but the viscosity,
It is preferable to use it in a range of 10 to 40% from the viewpoint of drying properties and the like.

In addition to the dyes and solvents described above, conventionally known dyes and additives can be added to the ink of the present invention.

As the preservative, sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxitona-1helium, sodium benzoate, sodium pentachlorophenol, etc. can be used in the present invention.

p) -1 As the adjusting agent, any substance can be used as long as it can control the pH of the ink within the range of 9.0 to 11.0 without adversely affecting the ink being prepared. be able to.

Examples include amines such as jetanolamine and triethanolamine, hydroxides of alkali metal elements such as lithium hydroxide, sodium hydroxide, and potassium hydroxide;
ammonium hydroxide, lithium carbonate, sodium carbonate,
Examples include alkali metal carbonates such as potassium carbonate.

Specific electrical conductivity regulators include, for example, potassium chloride,
Examples include inorganic salts such as ammonium chloride, sodium sulfate, and sodium carbonate, and water-soluble amines such as triethanolamine.

Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sulfurium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sulfurium diethylenetriaminepentaacetate, and sodium laumyldiacetate.

Examples of rust preventives include acidic sulfites, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, tetranitrile pentaerythritol,
Examples include dicyclohexylammonium nitride i.

Depending on the purpose, water-soluble ultraviolet absorbers, water-soluble infrared absorbers, water-soluble polymer compounds, dye solubilizers,
Surfactants and the like can be added.

Examples and comparative examples of the present invention are shown below.

All percentages are by weight.

Example 1 An ink was prepared by heating the following crude product to about 50° C., stirring and dissolving it, and then filtering it through a Teflon filter with a pore size of 0.22 μm. The physical properties of the ink are shown in Table-1.

Dye of specific example (1) 3.0% diethylene glycol 15.0% glycerin
5.0% Sodium dehydroacetate
0.2% water
Inks of Examples 2 to 5 and Comparative Examples 1 to 3 were prepared in the same manner as in Example 1 except that materials having the following compositions were used.

Example 2 Dye of specific example (7) 3.0% diethylene glycol 15.0% glycerin
5.0% Sodium dehydroacetate
0.2% water
7G, 8% Example 3 Specific example [Dye of 11 3.0% diethylene glycol 15.0% glycerin
5.0% Sodium dehydroacetate
0.2% water
76.8% Example 4 Specific example [111 dye 2.1% c,
r, Direct Yellow 86 0.9% Triethylene Glycol 10.0% 2.2'-Thiogetanol 10.0% Sodium Benzoate 0
．． 2% water
76.8% Example 5 Dye of Specific Example A 1.7% C, ■, Direct Red 227 o, 5% C, 1, Direct Yellow 0.8% Polyethylene Glycol 200
5,0% 1~lyeethylene glycol monomethyl ether 15,0% Sodium benzoate 0.2% Water
76.8% Comparative Example 1 Dye (C, i Direct Black 32) 3.0% Diethylene glycol 15.0% Glycerin 5.0% Sodium dehydroacetate 0.2% Water
76.8% Comparative Example 2 Dye (C, 1, Direct Black 51) 3.0% Diethylene glycol 15.0% Glycerin 5.0% Sodium dehydroacetate 0.2% Water
76.8% Comparative Example 3 Dye (C, 1, Acibuto Black 28) 3.0% Diethylene glycol 15.0% Glycerin 5.0% Sodium dehydroacetate 0.2% Water
76.8% Table 1 Physical properties of ink (carbon arc lamp, 63°C) Fading by the same method as 1-81 yp7. I asked for

Effects (I) Evaluation tests were conducted on the ink composition of Example 1 on four items. The results are shown below.

1) Image clarity and image drying properties: When the ink was jet-recorded on a commercially available high-quality paper using a particle frequency of 1100 kHz from a nozzle with an inner diameter of 30 μm, a clear black image without bleeding was obtained. The drying time of the recorded matter was within 10 seconds at room temperature and humidity.

2) Storage: The ink was sealed in a glass container and stored at -20°C for 1 month, 4°C for 1 month, 20°C for 1 year, and 90°C for 1 week, but no precipitation occurred. was not recognized. Further, no changes were observed in the physical properties or color tone of the ink.

3) Jetting stability: The jet recording described in 1) above was performed continuously for 1000 hours, and stable recording was achieved without clogging of the nozzle or change in the jetting direction.

4) Injection response: After performing jet recording according to 1) above, the jet was left at room temperature and humidity for one month and at 40°C and 30% R1-t for one week, and then jet recording was performed again according to 1). However,
As in 3) above, stable recording was possible.

([) When the inks of Examples 2 to 5 were tested for jetting response in the same manner as in Example 1, good results were obtained as in Example 1. On the other hand, in the case of Comparative Examples 1 to 3,
When left for one week at room temperature and humidity, and for three days at 40°C and 30% Rl-1, partial clogging of the nozzles occurred and the direction of ink jetting became extremely unstable, making jet recording impossible. .

Claims (1)

[Scope of Claims] A water-based ink composition characterized by containing at least one water-soluble dye represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ R_1; Hydrogen, alkyl group, alkoxy group, halogen,
Sulfonic acid group R_2; hydrogen, alkyl group, alkoxy group, halogen R_3, R_4; hydrogen, amino group, nitro group, sulfonic acid group, halogen, alkyl group, carboxyl group, carbamoyl group, sulfamoyl group, cyano group M; hydrogen, Indicates cations such as sodium, potassium, lithium, and organic amines. n=1 or 2.