JPS6143674A - water based ink - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous ink particularly suitable for inkjet recording, full color printers, and the like.

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

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

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, full-color ink used in printers, etc. must: 5) exhibit color tone with excellent purity;

Also, 6) The recorded image must of course be a clear image without smearing, with excellent water resistance, light resistance, and abrasion resistance.

is necessary.

In order to satisfy the above requirements, c, r,
Although it has been proposed to use Acid Red 254, 261, etc., at present no one has yet been obtained that fully satisfies all of the above conditions.

The properties required above are particularly influenced by the dyes among the materials used in the ink, and in order to satisfy these requirements, the development of new dyes has been underway.

Purpose The purpose of the present invention is to obtain an aqueous ink that satisfies all of the above-mentioned requirements for an ink.

Structure The present invention is a water-based ink characterized by containing at least one kind of water-soluble dye represented by the following general formula.

(R2) Butashi, X: GHz-1-CO-1-〇-1-S-
1-8Oz-1- R1, R2: Hydroxyl group, unsubstituted or substituted amine group: 0 or 1 R3, R4: Hydrogen, hydroxyl group, alkyl group, alkoxy group, halogen, cyano cloud, carboxyl group, sulfone group Any n+, n: 0 to 3 (same or different substituents may be used) M: cation such as hydrogen, lithium, sodium, potassium, or organic amine q: 1.2 or 3 In the above general formula used in the present invention Typical examples of water-soluble dyes for cough relief are shown below.

0H Although the ink of the present invention uses water as a solvent component, 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. , the following water-soluble organic solvents and water can also be used in combination.

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, others, N-methyl-2-gorolidone, 2-pyrrolidone, 1,3-dimethylimidazolidinone, dimethylformamide, triethanolamine 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 solubility of the dye and the effect of preventing clogging by preventing moisture evaporation. I can do it.

The content of the water-soluble organic solvent in the ink can range from 5 to 80% based on the total weight of the ink, but is preferably from 10 to 40% in view of viscosity, drying properties, etc.

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 and fungicidal agent, sodium dehydroacetate, sodium sorbate, subviridine thiol-1-oxitona 1~
Sodium benzoate, sodium pentachlorophenol, and the like can be used in the present invention.

As the pH adjuster, 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.

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,
These include inorganic salts such as ammonium chloride, sodium sulfate, and sodium carbonate, and water-soluble amines such as triethylamine.

Examples of chelating reagents include ethylenediamine, sodium tetraacetate, sodium nitrilotriacetate, sodium hydroxyoxyethylethylenediaminetriMlate,
Examples include sodium diethylenetriamine pentate and sodium lauryl diacetate.

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

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

Next, examples will be described. All percentages are by weight.

Example 1 After heating and stirring the following composition, the pH was adjusted to 1 with Na o+-+.
Adjust to 0,0, 0,2. Aqueous ink was obtained by filtration through a cz m filter.

Said N092 dye F31 3% diethylene glycol 22.5% glycerin
7.5% (Product name: Deltop 33, manufactured by Narita Pharmaceutical Co., Ltd.) 0.3% Ion-exchanged water 66.7% Example 2 Example 1 except that dye No. 015 was used instead of dye No. 2. The composition was the same.

Example 3 A water-based ink was prepared in the same manner as in Example 1 by mixing the following compositions.

Dye of N001 3% N-methylpyrrolidone 20% glycerin
10% (trade name Hokuside LX-If, manufactured by Hokukai Kagaku) 0.3% Ion-exchanged water 66.7% Example 4 The following compositions were mixed to prepare a water-based ink in the same manner as in Example 1.

Dye of NO,9 3% ethylene glycol 20% glycerin
10% Hokuside L X -If O,
3% ion exchange water 66.1% Example 5 In Example 4, dye No. 14 was used instead of dye No. 9.
The composition was the same except that the dye was used.

Example 6 A water-based ink was prepared in the same manner as in Example 1 by mixing with the following composition.

Dye No. 15 3% diethylene glycol 20% glycerin
10% Hokuside 0.3% ion exchange water
66.7% Comparative Example 1 A water-based ink was prepared in the same manner as in Example 1 by mixing the following composition (b).

C, 1, Acid Red 2543% Diethylene Glycol 20% Glycerin
1096 Hokuside
0.3% ion-exchanged water 66.7% Comparative Example 2 The composition was the same as in Comparative Example 1 except that the dyes were C,1 and Acid Red 9.

The following tests were conducted on the water-based inks of Examples and Comparative Examples.

1) Image clarity and drying properties Particle frequency 100 kl (z
The results were evaluated by inkjet recording on commercially available high-quality paper. The dryness of the recorded material was measured at room temperature and humidity.

2) Water-resistant ordinary high-quality paper and commercially available water-resistant treated paper (manufactured by Mitsubishi Paper Mills, N
Printing was carried out on M Coco paper) and expressed as the amount of decrease (%) in main color density after being immersed in water at 30° C. for 1 minute.

3) Light resistance The printed sample was irradiated with a carbon arc lamp for 20 hours and was expressed as the amount of decrease (%) in the main color density.

4) Seal the preservative ink in a glass container and store at -20°C for 1 month.
It was stored at ℃ for 1 month, at 20℃ for 1 year, and at 90℃ for 1 hour.

5) Jetting Stability The jet recording described in 1) was performed continuously for 1000 hours to check whether the nozzle was clogged or there was no change in the jetting direction and stable recording could be performed.

6) Injection response □ After recording the jet according to 1), inject at room temperature and pressure.
After being left for several months and at 40° C. and 30% RH for one week, jet recording was performed again to check whether stable recording could be performed.

The results are summarized and presented in a table.

As can be seen from the above results, none of the comparative examples satisfied all test results 1) to 6), but satisfactory results were obtained in all tests in the examples.

Patent Applicant Ricoh Co., Ltd. - Agent Patent Attorney Hidetake Komatsu Agent Patent Attorney Hiroshi Asahi EF - Rudome Nerli Masato] (Voluntary) October 2, 1980 Commissioner of the Japan Patent Office Manabu Shiga 1. 11! Indication of the matter: Japanese Patent Application No. 59-164772 2. Name of the invention: water-based ink 3. Relationship with the person making the amendment: Patent application Name: Ricoh Co., Ltd. 5. Date of amendment order (voluntary).

(Attachment) ■The scope of claims in the description is amended as follows.

2. Claims: A water-based ink characterized by containing at least one water-soluble dye represented by the following general formula.

However, X: CHz-1-c〇-1-0-1-S-
1-3O2-1- R1: Water R group, unsubstituted or B-substituted amino group R2: Hydroxyl group 〇 or 1 R3, R4: Hydrogen, hydroxyl group, alkyl group, Al: Di1-
cy group, halogen, cyano group, carboxyl group, sulfone group m, n: o to 3 (same or different types of substituents may be used) M: hydrogen, cation such as lithium, sodium, potassium, or acetic amino q: 1.2 or 3'' (2) The general formula on page 5 of Mei Am is corrected as follows.

(2) "rrtl, R2: hydroxyl group, unsubstituted or substituted amine group" in line γ of the same page is corrected as follows.

rR+: water 1'l12 group, either unsubstituted or substituted amino group R2: water M group'' ■■, page 6 of the specification cylinder Representative example of soluble dye No. 0.6 is corrected as shown below.

■, Representative example No. 12 on page 8 of the same is amended as follows.

Claims (1)

[Scope of Claims] A water-based ink characterized by containing at least one water-soluble dye represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ However, X: -CH_2-, -CO-, -O-, -S-
, -SO_2-, -R_1, R_2: hydroxyl group, unsubstituted or substituted amino group l: 0 or 1 R_3, R_4: hydrogen, hydroxyl group, alkyl group, alkoxy group, halogen, cyano group, carboxyl group, sulfone group Any of m, n: 0 to 3 (same or different substituents may be used) M: cation such as hydrogen, lithium, sodium, potassium, or organic amine q: 1, 2 or 3