JPS5928590B2 - water-based ink composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous ink composition, and its main purpose is to provide an aqueous ink composition having water resistance suitable for use in writing instruments, stamps, printing, and recording. It is on offer.

Conventionally, water-based ink compositions used for writing instruments, etc., have been made by mixing general water-soluble dyes with water and coal-based solvents. , for use in stamps, printing, and recording, the water resistance, light resistance, and corrosion resistance against metals were insufficient.

First of all, conventional water-based ink compositions have a low affinity for water-soluble dyes with the cellulose of paper, so if they are accidentally mixed onto documents that are being written on or have just been written on, water or When exposed to rain, the ink smudges, the letters become unclear, and the documents are stained.

In this case, a method of adding penetrants, activators, etc. may be considered as a measure to improve water resistance, but this method cannot achieve sufficient effects due to the inherent recessive nature of the dye structure. Next, writing materials made with conventional water-soluble ink compositions were subject to large color changes and staining when exposed to sunlight.

Furthermore, when acidic water-soluble dyes are used, they are highly corrosive to metals, causing discoloration and clogging. As a result of various studies to solve the above problems, the inventors of the present invention found that by using a yellow disazo dye of the general formula [wherein A is 1CO or
A water-based ink composition that has clear color tone, excellent water resistance and light resistance, is not corrosive to metals, and also has excellent performance as a complementary color to other colors such as black, red, orange, and green. They discovered that a product can be obtained and completed the present invention.

The aqueous ink composition according to the present invention is prepared by mixing the dye of general formula [1] with water, a water-compatible organic solvent, and, if necessary, a water-compatible surfactant. Examples of the water-compatible organic solvent to be mixed with the dye of general formula [1] include glycol solvents such as ethylene glycol, diethylene glycol, propylene glycol, and thiodiglycol, alcohol solvents, cellosolve solvents, and carbitol solvents. etc. Further, examples of the water-compatible active surfactant to be mixed with the dye of general formula [1] include penta-anionic surfactants, nonionic surfactants, amphoteric surfactants, and the like. The water-based ink composition thus obtained has a clear color tone, excellent water resistance and light resistance, is not corrosive to metals, and has excellent performance as a complementary color to other colors.

In short, the present invention is an aqueous composition that is optimal as an ink for writing instruments, an ink for stamps, an ink for dinit printing, an ink for recorders, and the like.

Next, five embodiments of the present invention will be explained regarding writing ink.

Example 1 Dye of the following formula 5 parts by weight (hereinafter, parts by weight are abbreviated as parts).

), 10 parts of ethylene glycol, 10 parts of diethylene glycol, 5 parts of thiodiglycol, 0.5 part of preservative, 0.5 part of butyl cellosolve, 0.2 part of Hytenol 08 (trade name), an anionic surfactant, and distilled water. 68.8 parts were mixed, heated and dissolved at 60 to 70°C, and then filtered to prepare a yellow aqueous ink composition according to the present invention. When the obtained ink composition was placed in a felt-tip pen container and a writing test was conducted, the ink did not fade at the pen tip, the ink always flowed out smoothly, the handwriting was clear in tone, and it had excellent water resistance. It had good durability and light resistance.

Example 2 A yellow aqueous ink composition according to the present invention was produced in the same manner as in Example 1, except that 5 parts of a dye of the following formula were used in place of the dye used in Example 1. I got it.

The obtained ink composition was similar to the composition of Example 1.
It had excellent performance. Example 3 5 parts of the dye of the following formula were mixed with 15 parts of ethylene glycol, 10 parts of diethylene glycol, 0.5 parts of preservative, and 0.5 parts of butyl cellosolve.
and 69.0 parts of distilled water and prepared in the same manner as in Example 1 to obtain a yellow aqueous ink composition according to the present invention.

The obtained ink composition had excellent performance similar to the composition of Example 1.

Example 4 A yellow aqueous ink composition according to the present invention was prepared in the same manner as in Example 3 in other respects, using 5 parts of a dye of the following formula in place of the dye used in Example 3. did.

The obtained ink composition had excellent performance as in Example 1. Example 5 (Example for complementary color of red ink) 1.5 parts of one of the dyes used in Examples 1 to 4, 4 parts of eosin (C.I. Assured 87), and 4 parts of phloxine (C.I. .Acid Dred 97) 2.5 parts, 10 parts of ethylene glycol, 10 parts of diethylene glycol, 5 parts of thiodiglycol, 0.5 part of preservative, 0.3 part of butyl cellosolve and 66.2 parts of distilled water, 50-60 parts ℃
After heating and dissolving the mixture, the mixture was filtered to prepare a red aqueous ink composition according to the present invention.

The resulting mixed aqueous ink composition had excellent performance similar to the composition of Example 1. Example 6 (Example for complementary color of green ink) 3 parts of one type of dye used in Examples 1 to 4 was added to 3 parts of water-soluble copper phthalocyanine (C.I. Direct Pull-86).
parts, 10 parts of ethylene glycol, 10 parts of diethylene glycol, 5 parts of propylene glycol, 0.5 parts of preservative,
The mixture was mixed with 0.5 parts of butyl cellosolve and 68.0 parts of distilled water, heated and dissolved at 50 to 60°C, and filtered to prepare a green water-based ink composition according to the present invention.

The resulting mixed color aqueous ink composition had excellent performance similar to the composition of Example 1.

Next, for comparison with the water-based ink composition according to the present invention 1 prepared in the above Examples, tartrazine (Food Yellow No. 4) and Sunset Elo, which are used in conventional yellow water-based ink compositions, Comparative ink compositions as shown in the following Reference Examples were prepared using C.I.Foodero-13 (trade name). Reference Example 1 A water-based ink composition was prepared by the method of Example 1 except that the dye in Example 1 was replaced with 5 parts of tartrazine.

Reference Example 2 A water-based ink composition was prepared according to the method of Example 1 except that only the dye in Example 1 was replaced with 15 parts of Sunset Elo.

Reference Example 3 1.5 parts of Sunset Elo 1 was used instead of "one of the dyes used in Examples 1 to 4" described in Example 5, and the rest was the same as Example 5. A red aqueous ink composition was prepared by color mixing.

Reference Example 4 In place of "one of the dyes used in Examples 1 to 4" described in Example 6, 1.5 parts of tartrazine was used, and the rest was the same as in Example 6. A green water-based ink composition was prepared by color mixing.

Table 1 shows a comparison between the performance of the aqueous ink compositions of the present invention obtained in the aforementioned Examples and the performance of the aqueous ink compositions also obtained in the aforementioned Comparative Examples.

Claims (1)

[Claims] 1 General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, A is -CO- or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ R is H, Cl, CH_3, OCH_3 or OC_2
H_5, R_1 are H, Cl, OH, NO_2, or COOH, R_2 is H, Cl, OH, or NO_2,
M represents H, Na, K or Li. ] A water-based ink composition characterized by containing a disazo dye represented by the following.