JPS6067575A - 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 Technical Field The present invention relates to a water-based ink with a red tone for various writing and recording purposes, and is particularly suitable as an inkjet recording ink.

BACKGROUND OF THE INVENTION Many patent applications have been filed regarding water-based inks using acid dyes and direct dyes listed in the Color Index as colorants. In addition, there are many types of dyes in the three basic colors of color reproduction: yellow, magenta, and cyan, but there is no dye that produces a good red color and satisfies the color material characteristics. do not have.

Purpose The present invention provides an aqueous ink with particularly good red color tone reproducibility, and particularly when used in inkjet recording, it facilitates improvement in jetting reliability and particle formation stability.

The present invention uses the following structural formulas (A) and (B) as colorants.
An aqueous ink characterized by containing:

Structural formula (B) (803M?) p It is.

Examples of the dye r1 corresponding to the above structural formula (A) are as follows.

COONa 803 Na I COONa 803 Na C0OH803Li 5- H3 COONa 803 Na OOH 6- Examples of dyes corresponding to structural formula (B) are as follows.

10-10- By coexisting in the water-based ink, the above two types of dyes make it possible to finely control the red color adjustment.
It improves the solubility of each species, increases the total dye concentration in the ink, and improves the image reflection density. It also provides more leeway in liquid physical property control and increases liquid stability.

The aqueous ink of the present invention contains water, a water-soluble organic solvent, an antiseptic and antifungal agent, and other commonly used additives.

Examples and comparative examples will be described below.

Example 1 Specific example A −+11 structural dye 2.0 wt% Specific example B
-+11 structural dye 2.5wt% diethylene glycol]-
Le 15,0wt% Glycerin 5,0wt% -11- Preservative and fungicide (Pultop 33 manufactured by Shikinichi Yakuhin) 0.3wt
% Pure water Remaining amount: A small amount of thorium hydroxide (adjusted to 110.5 liters) Mix and stir the above ingredients and stir and dissolve at 80°C for 3 hours. The solution was filtered through a membrane filter with a filter pore size of 0.2271 mφ to prepare ink (A).

Example 2 Specific example-8) Structural dye 2. Owt% Specific example B-(
81 structural beam Fl 3.0wt% polyethylene glycol (200) 20.0wt% glycerin s, owt
% Preservative Preservative Mold Agent Side LX-2) 0.4wt% Pure water Remaining amount Lithium hydroxide Small amount (DHlo, adjusted to 0) The above were mixed and stirred, and the mixture was stirred and dissolved at 75° C. for 4 hours. The solution was filtered through a membrane filter with a filter pore size of 0.22 μm to prepare ink (B).

Example 3 Specific example (A>-Structural dye of (7) 1.5 wt% Specific example (A) - (Structural dye of II o, 5 wt% Specific example (B)
- (Structural dye of 51 1.5wt% Specific example (B) - Old l
Structural dye 2.0wt% diethylene glycol 20
wt% Glycerin 10wt% Preservative and anti-mold agent (Pultop 33 manufactured by Shikinichi Yakuhin) 0.3wt
% Pure water Remaining amount Sodium hydroxide Small amount (EIHlo, adjusted to 3) Polyoxyethylene nonylphenyl ether o, 2 wt% Dissolved and filtered in the same manner as in Example 1 to obtain ink (C).

Comparative Example 1 13- Structural dye of Specific Example B-11 4.5wt% diethylene glycol 15.0wt% glycerin 5. Owt% Preservative preservative pull top 33) Pure water remaining
A small amount of sodium hydroxide (adjusted to IIHIo, 3) The above was dissolved and filtered in the same manner as in Example 1 to obtain ink (D).

Comparative Example 2 Specific Example A - (31 (7) Structural dye 5.Owt% Polyethylene glycol (200) 20.0wt% Glycerin g, owt% Preservative preservative Ka Shikiyaku pull top 33) 0.4wt
% Pure water Remaining amount Lithium hydroxide Small amount (adjusted to ρl-110.5) The above was dissolved and filtered in the same manner as in Example 2 to obtain ink (E).

14- Next, the following W value test was conducted using the ink described below.

1) Image clarity and image dryness: Particle frequency 100KH2 from a nozzle with an inner diameter of 30μm
Ink was jet-recorded on commercially available high-quality paper, ink-jet recording paper manufactured by Jujo Paper Industries, and Mitsubishi Paper Industries under the following conditions.

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, respectively.

3) Jetting stability: The jet recording described in 1) above was performed continuously for 1000 hours.

4) Jetting response: After jet recording was performed according to 1) above, the product was left at room temperature for one month and at 40° C. and 30% RH for one week, and then jet recording was performed again according to 1).

The test results for the above examples and comparative examples are shown in the table below.

As is clear from the above table, the ink of the present invention provides high tone images and stable recording even when used in inkjet recording.

In addition, the test results for inkjet recording described above indicate that even when used in water-based ballpoint pens, sign pens, fountain pens, etc., highly reliable and clear recordings can be stably obtained.

Patent applicant Rico Co., Ltd. Agent Patent Attorney Hidetake Komatsu Agent Patent Attorney Hiroshi Asahi 17-

Claims (1)

[Scope of Claims] A water-based ink characterized by containing as a coloring material, those having the following structural formulas (A) and (B). However, R1: hydrogen atom, -803M1, alkyl group,
Hydroxy group, R2: alkyl group, -COOM+, -803M. R3: hydrogen atom, alkyl group, =803! +, hydroxy group, C00M+, halogen group, m, n: any integer of 0, 1, 2.3, Ml:
Alkali metal, amine cation, ammonium ion, sum of R1 to R3, SO3M1 and -C00M1 is 2 or more, Structural formula (B) However, R4, R5: X-〇M2: H, Li, Na, K, amine or ammonium, p: an integer of 0, 1.2, the sum of p is 1 or more, R6: hydrogen, an alkyl group with 1 to 5 carbon atoms, an amino group, a hydroxyl group, or a halogen;