JPS58222167A - Recording ink for ink jet - Google Patents

Abstract

PURPOSE:To provide the titled yellow ink with good ejection stability and response, excellent in storage stability, and capable of forming images of high quality over a long period, by using a particular water-soluble dye. CONSTITUTION:About 0.5-8wt%, based on the total amt. of ink, water-soluble. dye [one or more of C.I. Direct Yellow 44 (dye of formula I ), 86, 100, 142 and 144, and C.I. Acid Yellow 1 (dye of formula II), 3, 17, 23 and 42], water, a wetting agent (e.g., glycerol), and an antiseptic or mildewproofing agent (e.g., sodium 2, 2-dimethyl-6-acetoxy-dioxane-1, 3-dehydroacetate) are mixed to prepare a recording ink for ink jet.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a yellow inkjet recording ink.

When obtaining a color image by an inkjet recording method, there is a method in which a plurality of color inks are ejected from a plurality of nozzles. At this time, in order to perform good recording of color images, the inkjet recording ink must satisfy all of the following conditions.

(aJ Ink viscosity, surface tension, specific conductivity, and density must be maintained within appropriate ranges as ink physical property values according to droplet generation method, droplet flight direction, and control direction; (b) Long-term storage , No precipitation occurs due to chemical changes, etc. during long-term use or when recording is stopped, and the physical properties of the ink do not change (the ejection nozzle of the recording device is
Generally, the diameter is about 10 to 60 μm, and if the nozzle is clogged due to precipitation, only droplets can be ejected1. Even if the nozzle is not completely tied, solids or sticky substances may adhere to the nozzle or the vicinity, or the desired amount may be removed when preparing the ink. If the ink physical property value adjusted to the value f changes, the recording performance, ejection response, and ejection stability will deteriorate. (C) The tone of the recorded image must match the intended tone (in the case of a multicolor image, the gray scale must be small so that it can be clearly distinguished from other colors). (In addition, the color tone must not change with long-term storage or use.) (d) The recorded image must have sufficiently high contrast and clarity (with conventional inks, the dye content in the ink If an attempt is made to increase the contrast of the image 11 by increasing the ratio, clogging of the discharge nozzle tends to occur.

Therefore, there is a need for dyes that have high solubility in the solvent used in ink and a high extinction coefficient. (e)
(f) the recorded image has water resistance, light resistance and abrasion resistance; and (f) it dries quickly after printing. (With conventional ink, in order to prevent nozzle clogging due to drying of the ink inside the nozzle during printing pauses, the ink contains a large amount of wetting agent. (Use special paper with high ink absorption.This not only causes significant image blurring but also makes it impossible to use many ordinary papers.)However, many proposals regarding ink have been made with this method. However, no ink has emerged that satisfies all of the above conditions.

Therefore, an object of the present invention is to provide an inkjet recording ink that satisfies the above-mentioned conditions as an inkjet recording ink and eliminates the above-mentioned drawbacks. More specifically, the present invention does not cause clogging of the ejection nozzle, deterioration or precipitation during storage, has good ejection stability and ejection response, and has good ink physical properties even when used for long periods of continuous circulation. The purpose of the present invention is to provide an inkjet recording ink which has a small change in value, has excellent weather resistance, has good color reproducibility, has little blurring, and is clear with high density.

In order to achieve the above object, the inkjet recording ink of the present invention contains C and I as water-soluble dyes.

Direct Yellow 44.86.100, 142.14
4 and C, 1, Acid Yellow 1.3.17.23
．． It is characterized by using at least one kind of 42.

Examples of water-soluble dyes used in the present invention are described below.

``144 Rei''° lower -1 (Kaido'Tani) 44 The following structural formula (RI) -Yellow-2 (Kaidogaya color) 5 - Structural formula COONa NO2 The water-soluble explosive dye selected in the present invention is It has a solubility of 2% □ or more in water.Also, its dissolved state is quite good, and when it is filtered through a 0.2 to 1 μm filter, it can be filtered without clogging the filter. Further, the dye of the present invention belongs to the yellow dye group in color inkjet recording, and can be contained in a proportion of 0.5 to 80% by weight in the total weight of the ink.When recording on no-size paper ,
Density 0.8 or more, hue difference 15% or less, and Blaine 2
It has a characteristic of less than 10% and can be used as the three primary colors of yellow.

In addition to the water-soluble dye, the inkjet recording ink of the present invention mainly contains water, a wetting agent, and an antiseptic and fungicidal agent.
Preservatives, viscosity modifiers, etc. may be added.

The wetting agent is used to prevent the ink from drying out and clogging the nozzle when ink jetting is stopped, and includes glycerin, diethylene glycol, ethylene glycol, triethylene glycol, and polypropylene. Aliphatic polyhydric alcohols such as glycol and polyethylene glycol and alkyl ether fatty conductors of these polyhydric alcohols can be used. In addition, a mixture of water and a water-soluble organic solvent as shown below may be used. Examples of the above water-soluble organic solvents include:
For example, amines such as triethanolamine, nitrogen-containing repeating ring systems such as N-methyl-2-pyrrolidone, 2-pyrrolidone, and 1,3-dimethylimidazolidinone, and oxycarboxylic acids such as valerolactone and caprolactone. There are intramolecular ester types, ethylene glycol monomethyl ether acetate (7ffi), and other selonlube acetate types.

As a water-soluble preservative, 2,2-dimethyl-6-7
Examples include setoxydioxane-1,3-dehyde 9-acetate, p-hydroxybenzoic acid butyl ester, potassium urbate, sodium 2-pyridinethiol-1-oxide, and anionic surfactants. Commercially available products of this type include the product name Pulltop 66 (manufactured by Kurade Yakuhin Kogyo Co., Ltd.) and Biocide 83.
0 (manufactured by Daima), etc.

Further, as the viscosity modifier, any well-known substance can be used as long as it is effective without adversely affecting the solvent and dye used. For example, polyvinyl Examples include alcohol, hydroxyethylcellulose, carboxymethylcellulose 2, methylcellulose, water-soluble acrylic resin, gum arabic, dextrin, casein, cutin, gum tragacanth, and polyvinylpyrrolidone.

As a pH adjuster that can be suitably used in the present invention, 10- is any substance that can control the pH of the ink within the range of 90 to 11.0 without adversely affecting the ink to be prepared. For example, amines such as jetanolamine and triethanolamine, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and ammonium hydroxide can be used.

In addition, substances that can be added to the inkjet recording ink of the present invention include specific electrical conductivity regulators, chelating reagents, and Rust inhibitors can be added.

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

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

Examples of the rust preventive include acidic average rRtJi, sodium thiosulfate, ammonium thioglycolic acid improbyl ammonium nitrite, Seinan RO taerythritol, dicyclohexylammonium nitrite, and the like.

Adjusting the surface tension of the inkjet recording liquid of the present invention, which is a mixture of the above components as appropriate, to a value of 40 dyne/m (25° C.) or more suppresses image blurring and ensures ejection stability. It is necessary for

The present invention will be explained in more detail by the following examples, but is not limited thereto.

In the figures, percentages are expressed by weight.

Example 1°C, 1, Acid Yellow 3 (Daiwa Kasei, Yellow≠47) 5.5
% diethylene glycol 12゜0
%Glycerin 4.0
% ion exchange water 80.29
% Sodium dehydroacetate 0.2
%Sodium Thiosulfate 0
0.1% or more of the composition was mixed, stirred, heated at 80° C. for 3 hours, cooled naturally, and filtered through a 0.22 μm Millipore filter to prepare yellow ink. Triethanolamine was added to the awns until the pH reached 1 o. When dyeing this ink on no-size paper, Wrattsn filter JI625.5
The density measurement through 8.47 showed a relative error of 5.0% and a grayness of 10.4 at 13.

Surface tension 7=61. Odyne/n (20℃)
Viscosity η-1.70 c, p, (
30℃) Conductivity = 3.20 mt7/(2
(2.5° C.) Next, various tests were conducted using this ink as follows.

1) Image clarity and image drying properties: When inkjet recording was performed on commercially available high-quality paper using a nozzle with an inner diameter of 60 μm at a particle formation frequency of 100 KHz, a clear image 1iI was obtained. The drying time of the recorded matter was within 10 seconds at room temperature and humidity.

2) Storage: Seal the ink in a glass container and store at -20°C for 1 month, 4
It was stored at ℃ for 1 month, at 20 ℃ for 1 year, and at 90 ℃ for 1 week, but -14 = No precipitation was observed. In general, no changes were observed in the physical properties or color tone of the ink, and the jetting stability: After 1,000 hours of continuous front-distribution jet recording, there was no clogging of the nozzle or change in the jetting direction. We were able to achieve a stable record.

Injection response: After jet recording was performed according to 1) above, the jet was left at room temperature and humidity for one month and at 40°C and 60% R and H for one week, and then jet recording was performed again. ,
Similar to 3) above, stable records were achieved.

Example 2゜Diethylene glycol 12.0%
Glycerin 4.0% Ioa-exchanged water 80.29% Acid sulfate 02% Butylethyl p-hydroxybenzoate 0.01%
An ink was prepared in the same manner as in Example 1 except for using the above composition. No size paper showed relative error of 132 and grayness of 95. As a result of numerous tests, the same results as in Example 1 were obtained.

γ=60. Odyne /rvr, (2(JC
) η = 1.75 c, p, (at 30°C) =
2.2 mtF/cycle (22.5°C) Example 68 Nogu-Yellow 20H) Diethylene glycol 12.0%
Glycerin 4.0% Ion exchange water 80.29% Sodium dehydroacetate 0.2
% Sodium thiosulfate 0.01
% Using the above composition, an ink was prepared in the same manner as in Example 1. No size paper showed a relative error of 98 and a gray scale of 96. As a result of numerous tests,
Similar results as in Example 1 were obtained.

1 = 6.1. Odyne/Qn (20℃)
η = 1.80 c, p, (50C) = 2
, OmtF/e (22.5°C) Example 4° An ink was prepared in the same manner as in Example 1 except that the following composition was used, and the following results were obtained.

drazine conc,) diethylene glycol 12.0%
Glycerin 4.0% Ion exchange water 80.29%9
% Sodium dehydroacetate 0.2
%Sodium thiosulfate 0.0
1%17-1=61. Odyne/m (20°C) η=1.
80 c, p, (30'C) = 2.
0 mty/Sono (22,5℃) Example 5
An ink was prepared in the same manner as in Example 1 except that the following composition was used, and the following results were obtained.

Yellow (), cone) Diethylene glycol 12.0% Glycerin 4.0% Ion exchange water 8029% Dehydroacetate 0.2% Sodium thiosulfate 0.01% r =
60. Odyne107& (20℃)η=
1.80 c, p, (,50'c)c
=2.1 mVF/a! n(22.5°C) Example 6°=18- An ink was prepared in the same manner as in Example 1 except for using the following composition, and the following results were obtained.

-MR) Diethylene glycol 12.0%
Glycerin 4.0% Ion exchange water 80.29% Sodium dehydroacetate 02%
Sodium thiosulfate 0.01
%7 = 59.0 ayne/rn (2
0℃]η=1.90 c, p, (30
℃)=2.2 mσ/閤 (22,5℃
) Example Z An ink was prepared in the same manner as in Example 1 except that the following composition was used, and the following results were obtained.

Diethylene glycol 12.0%
Glycerin 4.0% Ion exchange water 80.29% Sodium dehydroacetate 02%
Sodium thiosulfate 0.01
%y=59.5 dyne/cIn (200
) η = 1.90 c, p, (30℃)
= 21 mυ/m (22.5°C) Example 8° An ink was prepared in the same manner as in Example 1, except that the following composition was added, and the following results were obtained.

RhoRL) Diethylene glycol 12.0%
Glycerin 4.0% Ion exchange water 80.29% Sodium dehydroacetate 02% Sodium thiosulfate 0.01%
γ=60. [1dyneloIn(20℃)η=1
．． 85 C,p, (30C)K=2
, 2 mty/CIn (22.5°C) Example 9 An ink was prepared in the same manner as in Example 1 except for using the following composition, and the following results were obtained.

Yellow 2RH) Diethylene glycol 12.0%
Glycerin 4.0%
Ion exchange water 80.29
% Sodium dehydroacetate 0.2
%Sodium Thiosulfate 0
．． 01%γ=(So, Odyne/m (2o℃
η = 1.85 c, p, (30℃
)t = 2.1 m'cV0+1
(22°5°C) Regarding other dyes used in the present invention, inkjet recording inks were prepared in the same manner as described in Example 21 above and their performance was tested. The results were obtained.

Patent Applicant Riko Co., Ltd. 122- Procedural Amendment August 1980, No. 11 Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office 1, Indication of the Case Patent Application No. 105281 of 1983 3, Person making the amendment Relationship with the case Patent applicant address: 1-3-6 Nakamagome, Ota-ku, Tokyo Name: +6
74) Ricoh Co., Ltd. -4, Agent 5, Amended Order [''I.J (Voluntary) Akira: 11/11/1-1 (Date of dispatch Akira)
) Contents of Z correction 1) In the table on page 5, add "disazo" to the 6th and 4th blanks in the structural formula column.

2) Correct the structural formula (2) in the second line from the bottom of page 6 as follows.

6) Correct the structural formula (3) in the first line of page 7 as follows.

4) Correct the structural formula (5) on page 7, line 3 as follows.

2- = 3-

Claims (1)

[Claims] As a water-soluble dye, C, 1, Direct Yellow 86.
100.142.144 and C, L Acid Yellow 1.3.17.23.42.