JPS6337175A - Aqueous ink composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition suitable for printing, writing tools, recorders, stamps, etc., causing neither precipitation in preservation nor nozzle clogging, providing picture images with improved light resistance and water resistance, containing specific water-soluble dye. CONSTITUTION:The aimed ink composition containing at least one water-soluble dye shown by the formula [R1 is OH or (substituted)amino; R2 is H, OH or (substituted)amino; M is H, alkali metal, quaternary ammonium or basic amine; Ar is (substituted)aryl; m is 0 or 1; n is 1 or 2]. The amount of the dye added is preferably 1.5-6.0pts.wt. based on 100pts.wt. ink.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] [The present invention is an improved product]/Regarding a water-based ink for recording prizes, it is also applicable as a water-based ink for printing, writing instruments, recorders, and stamps.

[Prior Art] In inkjet recording, in order to perform good recording over a long period of time, it is necessary that the ink used satisfies the following conditions.

1> Ink viscosity, surface tension, specific conductivity, and density must be within appropriate ranges as ink physical properties depending on the droplet generation method and droplet flying direction control method.

2) During long-term storage, long-term use, or recording breaks, precipitation should not occur due to chemical changes, or the physical properties of the ink should not change.

3) The recorded image should have sufficiently high contrast and be 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, 5) The recorded image must of course be a clear image without any smearing, with excellent water resistance, light resistance, and abrasion resistance.

To date, many proposals have been made for inkjet recording inks to satisfy the above requirements, but the current situation is that no one has yet been found that fully satisfies all of the above conditions. .

The above-mentioned required properties are particularly matched by dyes among the materials used in ink, and the development of new dyes has been awaited to satisfy these demands.

[Objective] The purpose of the present invention is to provide a water-based ink for inkjet recording that solves the above-mentioned problems of the prior art. Specifically, it has excellent jetting characteristics, is free from clogging, and has particularly clear images. The objective is to provide water-based ink with excellent water resistance, water resistance, and light resistance.

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

- Throwing coins (However, in the above symbol for throwing coins, R1 is a hydroxyl group, an amino group, a substituted amino group, R2 is hydrogen,
Hydroxyl group, amino group, substituted amino group, M is hydrogen, alkali metal, quaternary ammonium, basic amine, Ar is substituted or unsubstituted aryl group, m is O or 1
, n is 1 or 2. ) The content of the dye expressed in the above-mentioned coin is 0.5 to 20.0 parts by weight, preferably 1.0 parts by weight, based on 100 parts by weight of the ink.
5 to 6.0 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 density of the resulting image will be insufficient; if it exceeds 20.0 parts by weight, precipitates will form in the ink over a long period of time. Therefore, inkjet recording tends to be inaccurate.

Further, in order to adjust the color tone or make the dye black, other blue dyes, red dyes, and yellow dyes can be used together with the dye of the present invention. Blue dyes that can be used in combination include C, 1
, Direct Blue-1, -8, -71, -76, -8
6, -108, -200, -201, -202, -23
6ya C, 1, acid blue-1, -7, -9, -15
, -175, -249, etc., but red dyes include C,1, Direct Red -1, -9, -15, -17, -28, -
37, -62, -75, -81, -83, -89, -9
9, -220, -225, -227 and C, 1, acid red -35, -44, -52, -82, -92, -9
4, -115, -131, -134, -154, -18
6, -249, -254, -289, etc., but yellow dyes include C, 1, Direct Yellow -12, -27, -28,
-33, -39, -44, -50, -58, -85, -
86, -87, -88, -100, -110, -142
, -144, C,1, acid yellow -7, -17,
-23, -42, -44, -79, -99, -142, etc., others C,1, Direct Orange 26, C,1,
Examples include Reactive Blue 2.

Specific examples of water-soluble dyes used in the present invention are listed below.

However, this compound Only the substituent C when expressed as is exemplified below.

Nine death , ゎ,. O charge 4□1,8 age. . Ok, 13 years old.

For example, the dye shown in specific example (1) is 3.6-bis(4
-aminostyryl)-9-ethylcarbazole 4.3g
was added to 250 ml of 3% hydrochloric acid and stirred at below 5°C, and an aqueous solution of 1.5 g of sodium nitrite dissolved in 20 ml of water was gradually added to diazotize the mixture. After stirring for 1 hour, remaining nitrous acid was eliminated with sulfamic acid to obtain a diazo solution.

Next, 7.2 g of sodium 1-amino-8-naphthol-3,6-disulfonate was dissolved in 10% sodium carbonate aqueous fj,
The mixture was dissolved in 300 ml and stirred at 5°C or below, and the diazotized solution was slowly added thereto and stirred for 3 hours to perform coupling. After completion, 50 g of a sample was added and salted out, and the precipitated dye was filtered, washed with 200 ml of 10% saline, and dried.

Soxhlet extraction was carried out with 200 ml of lactanol for 5 hours and desalted to obtain 0.2 g of the dye of Example (1).

Furthermore, specific examples of water-soluble dyes in which the substituent C of the above-mentioned -token is replaced with different groups will be shown.

(shi■3ノ4NU3b) These dyes can be easily synthesized. For example, the dye shown in Specific Example (17) is prepared by mixing 4.8 g of 2-amino-5-naphthol-7-sulfonic acid with 100 ml of water and caustic soda. 1. Dissolve in an aqueous solution of 0g.After adding 1.5g of sodium nitrite to this solution, add 1.5g of 3% hydrochloric acid while stirring at 5°C.
The mixture was added little by little to 50 ml of water for diazotization. After roughly stirring for 3 hours, remaining nitrous acid was eliminated with sulfamic acid to obtain a diazo solution.

3.8 g of m-phenylenediamine-4-sulfonic acid was added to this diazo liquid, and the mixture was stirred at 10°C for 15 hours for coupling. Thereafter, the mixture was stirred for 3 hours as I)H3 with sodium acetate to obtain a yellowish brown monoazo liquid. Add 150 ml of 10% caustic soda aqueous solution to this monoazo solution to make it alkaline. Next, 3.6-bis(4-aminostyryl)
-4.3g of 9-ethylcarbazole in 250ml of 3% hydrochloric acid
1 and stirred at below 5°C, and diazotized by slowly adding an aqueous solution of 1.5 g of sodium nitrite dissolved in 20 ml of water. After roughly stirring for 1 hour, remaining nitrous acid was eliminated with sulfamic acid to obtain a diazo solution.

Add this diazo solution to the previously alkaline monoazo solution by 5°.
The mixture was added under stirring at a temperature below C and allowed to react for 3 hours. After finishing, add 50g of common salt for salting out, filter the precipitated dye,
After washing with 250 ml of % saline solution, it was dried. Soxhlet extraction was carried out with 200 ml of methanol for 5 hours for desalting treatment to obtain 11.31 J of the dye of Example (17).

Specific examples of other water-soluble dyes in which the substituent C of the above-mentioned coin is replaced with a substituent different from the above-mentioned specific examples are shown below.

These dyes can be easily synthesized. For example, the dye shown in Variant Example (35) is P-chloroaniline 2
．． 6 g was added to 100 ml of 3% hydrochloric acid and stirred at below 5°C, and an aqueous solution of 1.5 g of sodium nitrite dissolved in 20 ml of water was slowly added to diazotize the mixture. After roughly stirring for 1 hour, remaining nitrous acid was eliminated with sulfamic acid to obtain a diazo solution.

Next, 7.2 g of sodium 1-amino-8-naphthol-3°6-disulfonate was added to 300 ml of water and stirred for 1 hour to form a uniform slurry.

The above diazo solution was added to this, stirred at 5°C for 5 hours, and then left in the refrigerator for 72 hours. Then with sodium acetate f)l-
The mixture was mixed with 1 and 3 and stirred for 3 hours to obtain a red monoazo liquid. Add 150 ml of 10% caustic soda aqueous solution to this monoazo solution to make it alkaline.

Meanwhile, 4.3 g of 3.6-bis(4-aminostyryl)-9-ethylcarbazole was added to 250 ml of 3% hydrochloric acid at 5°C.
Stir as follows, add 1.5 ml of sodium nitrite to 20 ml of water.
An aqueous solution in which g was dissolved was slowly added to diazotize the mixture. After roughly stirring for 1 hour, remaining nitrous acid was eliminated with sulfamic acid to obtain a diazo solution.

Add this diazo solution to the previously alkaline monoazo solution by 5°.
The mixture was added under stirring at a temperature below C and allowed to react for 3 hours. After finishing, add 60g of common salt for salting out and filter the precipitated dye to give 10%
It was washed with 250 ml of saline and then dried. methanol 2
The mixture was subjected to Soxhlet extraction using 00 ml for 5 hours and desalted to obtain 12.7 g of the dye of Example (35).

The ink of the present invention uses water as a solvent component, but in order to adjust the physical properties of the ink to desired values, to prevent the ink from drying, to improve the solubility of the dye, etc. It is also possible to use a mixture of an organic solvent 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 7-methyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene Alkyl ethers of polyhydric alcohols such as glycol monomethyl ether and triethylene glycol monoethyl ether, other N-methyl-2-pyrrolidone,
2-pyrrolidone, 1,3-dimethylimidazolidinone,
Filter with dimethylformamide, triethanolamine, etc.

Among these, particularly preferred are diethylene glycol,
Polyethylene glycol 200~eoo, triethylene glycol, ethylene glycol, glycerin, N
-Methyl-2-pyrrolidone, and by using these, it is possible to obtain high dye solubility and the effect of preventing clogging by preventing moisture evaporation.

The content of the aqueous organic solvent in the ink can range from 5 to 80% based on the total weight of the ink, but it is preferably used from 15 to 60% in view of viscosity, drying properties, etc.

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

For example, as the preservative and fungicide, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol, etc. can be used in the present invention.

t) Any substance can be used as the H adjuster as long as it can control the I)H of the ink within the range of 9.0 to 11,0 without adversely affecting the ink being prepared. .

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

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

Examples of rust preventives include acidic sulfites, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

In addition, water-soluble ultraviolet absorbers, water-soluble infrared absorbers, water-soluble polymer compounds, dye solubilizers, surfactants, etc. can be added depending on the purpose.

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

All percentages are by weight.

Example 1 (Blue ink) After heating the following composition to about 50'C and stirring and dissolving it,
An ink was prepared by filtration through a Teflon filter with a pore size of 0.22 μm.

Dye of specific example (1) 3.0% diethylene glycol 15.0% N-methyl-2-pyrrolidone 15.0% sodium dehydroacetate 0.2
% water 66.8%
Inks of Examples 2 to 21 and Comparative Examples 1 to 6 were produced in the same manner as Example 1 except that materials having the compositions shown below were used.

Example 2 (blue ink) Dye of specific example (3) 3.0% polyethylene glycol 200 15.0% triethylene glycol monomethyl ether 5.0% sodium dehydroacetate 0.2% water
76.8% Example 3 (blue ink) Dye of specific example (4) 3.0% diethylene glycol 20.0% 1.3-dimethylimidazolidinone 5.0% 2.2-dimethyl-6-acetoxy Dioxane-1.3 0.3% Water 71°7%
Example 4 (blue ink) Dye of specific example (5) 3.0% diethylene glycol 20.0% glycerin
5.0% 2.2-dimethyl-6-acetoxydioxane-1.3 0.3% Water 71.7% Example 5 (blue ink) Dye of specific example (9) 2.5% Polyethylene glycol 200 15.0% Triethylene glycol monomethyl ether 5.0% Sodium 2-pyridinethiol-1-oxide 0.3% Water
77.2% Example 6 (black ink) Dye of specific example (12) 2.0% C, 1, Direct Orange 26 1.0% diethylene glycol
15.0% N-methyl-2-pyrrolidone 15.
0% sodium dehydroacetate 0.2% water
66.8% Example 7 (
Black ink) Dye of specific example (13) 1.5% C, 1, Direct Red 227 1.0% C, 1, Direct Yellow 860.5% diethylene glycol 20
．． 0% glycerin 5.0% 2.2-
Dimethyl-6-acetoxydioxane-1.3 0.3% water
71.7% Example 8 Dye of Specific Example (17) 3.0% Diethylene glycol 15.0% N-methyl-2-pyrrolidone 15.0% Sodium dehydroacetate 0.2% Water 66.8% Example 9 Specific Dye of Example (19) 3.0% Polyethylene Glycol 200 15.0% Triethylene Glycol Monomethyl Ether 5.0% Sodium Dehydroacetate 0.2% Water
76.8% Example 10 Dye of specific example (21) 3.0% diethylene glycol 20.0% 1.3-dimethylimidazolidinone 5.0% 2.2-dimethyl-6-acetoxydioxane-1. 3 0.3% water
71.1% Example 11 Dye of specific example (24) 3.0% diethylene glycol 20.0% glycerin
5.0% 2.2-dimethyl-6-acetoxydioxane-1.3 0.3% water
71.7% Example 12 Dye of Specific Example (28) 3.0% Polyethylene Glycol 200 15.0% Triethylene Glycol Monomethyl Ether 5.0% Sodium 2-Pyridinethiol-1-oxide 0.3% Water
76.7% Example 13 Dye of Specific Example (31) 3.0% Diethylene glycol 15.0% N-methyl-2-pyrrolidone 15.0% Sodium dehydroacetate 0.2% Water 66.8% Example 14 Specific Dye of Example (32) 3.0% diethylene glycol 20.0% glycerin
5.0% 2.2-dimethyl-6-acetoxydioxane-1.3 0.3% water
71.7% Example 15 Dye of Specific Example (35) 3.0% Diethylene glycol 15.0% N-methyl-2-pyrrolidone 15.0% Sodium dehydroacetate 0.2% Water 66.8% Example 16 Specific Dye of Example (38) 3.0% Polyethylene Glycol 200 15.0% Triethylene Glycol Monoethyl Ether 5.0% Sodium Dehydroacetate 0.2% Water
76.8% Example 17 Dye of specific example (40) 3.0% diethylene glycol 20.0% 1.3-dimethylimidazolidinone 5.0% 2.2-dimethyl-6-acetoxydioxane-1.3 0 .3% water
71.7% Example 18 Dye of specific example (43) 3.0% diethylene glycol 20.0% glycerin
5.0% 2.2-dimethyl-6-acetoxydioxane-1.3 0.3% water
71.7% Example 19 Dye of Specific Example (45) 3.0% Polyethylene glycol 200 15.0% 1-heryethylene glycol monomethyl ether 5.0% Sodium 2-pyridinethiol-1-oxide 0.3% Water 76 .7% Example 20 Dye of specific example (48) 3.0% diethylene glycol 15. O% N-methyl-2-pyrrolidone 15.0% Sodium dehydroacetate 0.2%
Water 66.8%
Example 21 Dye of specific example (50) 3.0% diethylene glycol 20.0% glycerin
5.0% 2.2-dimethyl-6-acetoxydioxane-1.3 0.3% water
71.7% Comparative Example 1 C,1, Direct Black 32 3.0% Diethylene glycol 15.0% N-methyl-2-pyrrolidone 15.0% Sodium dehydroacetate 0
．． 2% water 66.
8% Comparative Example 2 C,1, Acid Black 2 3.0% Polyethylene Glycol 200 15.0% Triethylene Glycol Monomethyl Ether 5.0% Sodium Dehydroacetate 0.2% Water
76.8% Comparative Example 3 C,'1. Food Black 2 3.0% diethylene glycol 20.0% glycerin
5.0o62.2-dimethyl-6-acetoxydioxane-1.3 0.3% water
71.7% Comparative Example 4 C,1, Direct Blue 86 3.0% Diethylene Glycol 15.0% N-Medi-2-pyrrolidone 15.0% Sodium Dehydroacetate 0.
2% water 66.
8% Comparative Example 5 C,1, Acid Blue 1 3.0% Polyethylene Glycol 200 15.0% Triethylene Glycol Monomethyl Ether 5.0% Sodium Dehydroacetate 0.2% Water
76.8% Comparative Example 6 C,1, Acid Blue 93.0% Diethylene Glycol 20.0% Glycerin
5.0% 2.2-dimethyl-6-acetoxydioxane-1.3 0.3% water
71.7% Test Results The following tests were conducted for Examples 1 to 21 and Comparative Examples 1 to 6.

1) Image clarity An inkjet printer for Word Brosser Report 5600J manufactured by Ricoh was filled with the prepared ink and printing was performed.

Inks from which clear images were obtained are indicated by a circle in Table 1.

2) Light resistance of image The image sample obtained in 1) was exposed to a fade meter (carbon arc lamp, 63°C) for 3 hours, and the image density before and after light irradiation was measured using a Macbeth densitometer. The light resistance (
1 color rate) was determined.

Fading rate (%) = [1-(Image density after light irradiation/Image density before light irradiation)]xlOO 3) Water resistance of image The image sample obtained in 1) was immersed in water at 30'C for 1 minute. , Measure the image@density before and after immersion with a Macbeth densitometer, and (2
) The water resistance (fading rate %) was determined using the same formula as the formula in section ).

4) Place the preservative ink in a polyethylene container and heat at -20'C, 4
The samples were stored for 3 months under the following conditions: °C, 20°C, 50'C, and 70°C, and the changes in viscosity, surface tension, and electrical conductivity before and after storage were examined, as well as the presence or absence of precipitate precipitation. In Table 1, samples with no change in physical properties or generation of precipitates were marked as ○ no matter what conditions they were stored under.

5) After printing in nozzle clogging test 1), the print remains stationary at 20'C165%.
The paper was left in an RH environment for two months, and it was examined whether normal printing was possible again after being left in the environment.

One ink sample was tested using three printers.

In Table 1, the case where all three printers were able to print normally is shown as O, the case where one or two of the 13 printers were not able to print normally is shown as X, and the case where all three printers were not able to print normally is shown as XX. The 5600J printer is equipped with a device that automatically detects when the nozzle becomes clogged and cannot jet, or when the jet jet direction changes significantly compared to before it was left unused, and stops the printer's operation. is installed.

Table 1 Continuation of Table 1 [Effects] As explained above, the aqueous ink composition of the present invention does not cause problems such as precipitation during storage, and therefore does not cause nozzle clogging.

In addition, images drawn with this water-based ink are clear and have particularly excellent light resistance and water resistance.

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. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, among the symbols in the general formula above, R_1 is hydroxyl group, amino group, substituted amino group, R_2 is hydrogen, hydroxyl group, amino group, substituted amino group, M is hydrogen , alkali metal, quaternary ammonium, basic amine, Ar is a substituted or unsubstituted aryl group, m is 0 or 1, n is 1 or 2).