JPS629270B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a yellow water-based ink. More specifically, it relates to a yellow water-based ink that has good dissolution stability and good water resistance when written on paper. Conventional yellow water-based inks generally use acidic dyes because they require clear color tone and light resistance. However, acid dyes have the disadvantage of poor water resistance when written on paper. or,
Direct dyes are preferable in terms of water resistance, but they have the disadvantage that high concentration water-based ink cannot be obtained due to poor solubility, and when filled into felt-tip pens, dyes may precipitate on the pen tip over time. . An object of the present invention is to provide a dye that has good color tone and solubility like acid dyes, and has good water resistance like direct dyes. As a result of intensive research to obtain such a dye, the present inventors have achieved the object of the present invention by obtaining a dye having the structure of the following general formula and/or formula. (In the general formula, Q is

【formula】

Represents [formula]. ) This type of dye can be easily synthesized in the same way as basic acid dyes. For example, in the general formula, Q is

In the case of [Formula], the basic dyes are CI Acid Yellow 42 and CI Acid Yellow 44, which are substituted with an amino group. The presence of four amino groups in the dye facilitates hydrogen bonding with the hydroxyl groups of cellulose. It tends to aggregate due to the sizing agent (acidic) contained in the paper. It is thought that water resistance is improved because of these properties. Next, the dye of the present invention will be explained. All dyes have two sulfonic acid and four amino groups in their structures. The amount used is based on the total amount of ink.
A content of 0.5 to 20% by weight is desirable, and if it is less than 0.5% by weight, it is substantially dilute and may not be usable as a yellow ink, and if it is more than 20% by weight, it is uneconomical in terms of color tone, so it is preferably 2 to 15% by weight. be. In the ink solvent of the present invention, water and other known and publicly used alcohols, glycols, and glycol derivatives can be used as the main ingredient, and the amount of the solvent other than water used is 5 to 70% by weight based on the total amount of the ink. Other surfactants and preservatives may be used as necessary. The present invention can be easily achieved by preparing the yellow water-based ink by stirring the above-mentioned components at room temperature or at elevated temperature. Next, the present invention will be specifically explained using examples. In the examples, parts simply refer to parts by weight. Example 1

[Table] A yellow water-based ink of the present invention was obtained by stirring the above components at room temperature. Comparative example 1 Suminol Milling Prilliant Yellow
5G (CI Assisted Yellow 44, manufactured by Sumitomo Chemical Co., Ltd.,
A yellow aqueous ink was prepared by using 8.5 parts of the structure of Example 1, in which all amino groups were replaced with hydrogen, in place of the dye. Example 2

[Table] A yellow water-based ink of the present invention was obtained by stirring the above components at room temperature. Comparative Example 2 A yellow water-based ink was obtained by using the same amount of Diakyupro Yellow 2GL (CI Direct Yellow 39, manufactured by Mitsubishi Chemical Industries, Ltd.) in place of the dye in Example 2.
Each of the yellow water-based inks of Examples 1 and 2 and Comparative Examples 1 and 2 was filled into a commercially available felt-tip pen, and written on JISP3201 writing paper. One hour later, the handwriting was immersed in still water for 30 minutes. Next, the felt-tip pens filled with each water-based ink were left horizontally in a constant temperature and humidity room at 50°C and 30% humidity for one week, and the dye precipitation at the pen tip was observed. Pour 50ml of each yellow ink into a glass bottle, seal it, and bring it to 0°C.
The sample was left for one month and the state of precipitation of the dye was observed. The above results are shown in Table 1 below.

【table】

[Table] As shown in Table 1, the ink of the present invention has good water resistance and stability over time.

Claims (1)

[Scope of Claims] 1. A yellow water-based ink characterized by containing a dye represented by the general formula and/or formula. (Q in the general formula represents [formula] [formula].)