JPH0422952B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a water-based ink for ballpoint pens, and more particularly to a water-based ink for ballpoint pens that has excellent lubricity and has a smooth writing feel. Conventional water-based inks for ballpoint pens are made by adding direct dyes, acid dyes, basic dyes, etc. to an aqueous solution of water-soluble organic solvents such as glycol solvents, glycol ether solvents, glycol ether ester solvents, and amine solvents as evaporation inhibitors. These are low viscosity water-based inks made by dissolving water-soluble dyes and adding preservatives and anionic or nonionic surfactants as appropriate, but these water-based inks lack lubricity,
The problem is that there is a lot of friction between the ball and the tip, and when writing, there is a lot of friction between the ball and the tip, and when writing, there is abrasion noise between the ball and the tip, and the writing taste is not smooth. Abrasion occurs on the synthetic resin or metal ball seat, and the clearance between the ball and the tip from which ink is drawn is blocked, resulting in insufficient ink being drawn to the tip of the ball, resulting in poor handwriting. There was a problem that the writing became blurred, making it difficult to write smoothly. In recent years, attempts have been made to add water-soluble cutting oil to water-based ink in order to solve these problems, but satisfactory effects have not been obtained and new problems have arisen, such as blurring of handwriting. ing. Therefore, the present inventors have completed the present invention as a result of intensive research in order to solve the above-mentioned problems.
The gist of the present invention is a water-based ink for ballpoint pens comprising at least a water-soluble dye, a compound represented by the following general formula (), a water-soluble organic solvent, and water. (In the formula, 1 to 3 of R ₁ to R ₄ represent -PO(OH) ₂ and the residue represents -COOH.) What is particularly important in the present invention is that Why is it that the water-based ink of the present invention using the compound represented by the above general formula () has excellent lubricity, prevents friction between the ball and the chip, and prevents friction between the ball and the chip? Although it is not certain whether this has the effect of preventing wear of the ball seat part, it is speculated as follows. The phosphoric acid group and carboxyl group in the compound represented by the general formula () exert some action on the ball and the chip, and improve lubricity in order to minimize the frictional resistance between the ball and the chip. It seems to make the writing smoother. Next, each component used in the present invention will be explained in detail. Acid dyes, direct dyes, and basic dyes can be used as water-soluble dyes.As acid dyes, CIAcid
Yellow 23, CIAcid Yellow 42, CIAcid
Red 18, CIAcid Red 52, CIAcid Red 87,
CIAcid Blue 1, CIAcid Blue 9, CIAcid
Blue 90, CIAcid Black 2, etc. Direct dyes include CIDirect Black 19, CIDirect
Black 38, CIDirect Blue 86, CIDirect Blue
15, CIDirect Red 80, CIDirect Red 75, C.
I.Direct Red 28, etc., and these can be used alone or in combination. In addition, as basic dyes, CIBasic Yellow 35, CIBasic
Red 1, CIBasic Violet 1, CIBasic Blue
7, CIBasic Blue 9, etc., and can be used alone or in combination. Therefore, the amount of these water-soluble dyes used is 0.5 to 25% of the total amount of ink.
% by weight, preferably 1.0-20% by weight. Next, the compound represented by the general formula () is used for the purpose of imparting lubricity to the ink of the present invention, and its usage amount is 0.01 to 10% by weight, preferably 0.05 to 5% by weight based on the total amount of the ink. It is. If it is less than 0.05% by weight, the effect is small, and if it is more than 5% by weight, no further effect can be obtained and it is disadvantageous in terms of cost. Water-soluble organic solvents include ethylene glycol,
Glycols such as diethylene glycol and propylene glycol; glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; carbitols such as diethylene glycol monomethyl ether and diethylene glycol monoethyl ether;
Examples include sulfolane, thiodiethylene glycol, acetin, etc., and these can be used alone or in combination, and the amount used is 5 to 40% by weight, preferably 10 to 35% by weight, based on the total amount of the ink. Water is used as the main solvent, and the amount used is 50 to 85% by weight based on the total amount of the ink. In addition to the above-mentioned components, various additives such as preservatives, activators, and rust preventives may be used as necessary. Next, the method for manufacturing the ink of the present invention will be briefly described. The ink of the present invention can be produced by a simple operation of mixing and dissolving the above-mentioned components, but the ink can be obtained more easily by heating and stirring at an appropriate level. Hereinafter, the present invention will be explained in more detail with reference to Examples. In the examples, "parts" indicate "parts by weight." Example 1 CIAcid Black 2 10.0 copies

Compound A represented by the formula: 0.2 parts Ethylene glycol 25.0 parts Water 64.6 parts Neugen P (surfactant, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
0.2 parts Mix each of the above ingredients and heat to 40-60℃, approx. 1 part
A black ink was obtained by stirring for a period of time. Comparative Example 1 A black ink was obtained in the same manner as in Example 1, except that Compound A in Example 1 was removed and water was added in the same amount. Example 2 CIAcid Red 52 8.0 parts

Compound B represented by the formula: 0.5 parts Propylene glycol 20.0 parts Ethylene glycol monoethyl ether 10.0 parts Water 61.4 parts Proxel GXL (preservative) 0.1 part A red ink was obtained using the above components in the same manner as in Example 1. Comparative Example 2 A red ink was obtained in the same manner as in Example 2, except that Compound B in Example 2 was removed and water was added in the same amount. Example 3 CIBasic Blue 7 3.0 copies

Compound C represented by the formula: 2.0 parts Ethylene glycol 25.0 parts Sulfolane 5.0 parts Water 64.6 parts BTL (preservative) 0.4 parts A blue ink was obtained using the above components in the same manner as in Example 1. Example 4 A blue ink was obtained in the same manner as in Example 3 except that Compound C of Example 3 was reduced to 0.02 part and water was added in an amount equivalent to the reduced amount. Comparative Example 3 A blue ink was obtained in the same manner as in Example 3, except that Compound C in Example 3 was removed and water was added in the same amount. Example 5 CIDirect Black 38 8.0 copies

Compound D represented by the formula: 1.0 parts Diethylene glycol 15.0 parts Diethylene glycol monoethyl ether 15.0 parts Water 60.4 parts Score Roll 900 (surfactant, Kao Atlas Co., Ltd.)
(manufactured by) 0.4 parts Phenol (preservative) 0.2 parts A black ink was obtained using the above ingredients in the same manner as in Example 1. Comparative Example 4 A black ink was obtained in the same manner as in Example 5 except that Compound D was removed from Example 5 and water was added in the same amount. The inks obtained in Examples 1 to 5 and Comparative Examples 1 to 4 above were filled into a commercially available water-based metal ballpoint pen (Super Ball BH16, manufactured by Pentel Co., Ltd.), and the writing distance was
Table 1 shows the results of testing for the amount of ball sinking after writing and the presence or absence of unpleasant sounds during writing.

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Claims (1)

[Scope of Claims] 1. A water-based ink for ballpoint pens comprising at least a water-soluble dye, a compound represented by the following general formula (), a water-soluble organic solvent, and water. (In the formula, 1 to 3 of R ₁ to R ₄ represent -PO(OH) ₂ and the residue represents -COOH.)