JPS6116974A - Water-based ink composition for ball point pens - Google Patents

Abstract

PURPOSE:The titled composition that is obtained by adding a specific amount of a soap of potassium oleate to an ink composition containing a water-soluble organic solvent and a water-soluble dye, thus showing good lubricity to prevent the wearing between the ball holder and the ball in a ball point pen. CONSTITUTION:The objective composition is obtained by adding 0.02-5.0wt% of potassium oleate soap to a composition of a water-soluble organic solvent such as ethylene glycol or methyl cellosolve, preferably in an amount of 5- 40wt% and water-soluble dyes. Further, an anticorrosive is desirably added in order to avoid the corrosion of the chip and improve the stability of the composition with the passage of time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a water-based ink composition for ballpoint pens, more specifically, it has excellent lubricity, has the effect of completely preventing wear between the ball holder of the tip and the ball, and has a flavor. This invention relates to a smooth aqueous ink composition for ballpoint pens.

BACKGROUND OF THE INVENTION Conventionally, water-based inks for ballpoint pens have been prepared by adding a water-soluble polyhydric alcohol such as a glycol solvent or a glycol ether ester solvent to an aqueous solution containing a water-soluble dye.

However, such water-based inks have poor lubricity, so when the ball rotates during writing, the gap between the ball and the holder becomes wider, causing the ball to wobble or rotate irregularly. As a result, there are disadvantages such as loss of good initial writing feel and non-uniform ink flow.

Problems to be Solved by the Invention The purpose of the present invention is to improve the drawbacks of the conventional water-based ink for ballpoint pens, to provide excellent lubricity, long-term stability, and prevention of bleeding, and to improve writing quality. An object of the present invention is to provide a smooth aqueous ink composition for a ballpoint pen.

Means for Solving the Problems As a result of various studies, the present inventors have found that by blending a predetermined amount of potassium oleate soap into an ink composition containing a water-soluble organic solvent and a water-soluble dye. We have found a way to achieve the objective, and based on this knowledge, we have completed the present invention.

That is, the present invention provides an ink composition comprising a water-soluble organic solvent and a water-soluble dye, and further contains 0.02 to 0.02% of potassium oleate soap, based on the weight of the entire ink composition.
The present invention provides an aqueous ink composition for a ballpoint pen containing 5.0% by weight.

Examples of the water-soluble organic solvent used in the water-based ink composition of the invention include water-soluble polyhydric alcohols such as ethylene glycol and propylene glycol, cellosolve solvents such as methyl cellosolve, and glycols such as ethylene glycol monoethyl ether acetate. Preferred examples include ether ester solvents. These water-soluble organic solvents may be used alone or in combination of two or more, and the preferred content thereof is in the range of 5 to 40% by weight based on the total composition.

1. The water-soluble dye used in the aqueous ink composition of the present invention can be arbitrarily selected from acid dyes, direct dyes, basic dyes, etc. that are used in ordinary aqueous ink compositions.

The water-based ink composition of the present invention is prepared by dissolving the above-mentioned water-soluble organic solvent and water-soluble dye in water, and adding a preservative and a preservative, if necessary.
A nonionic surfactant, a water-soluble resin, etc. are added to the aqueous solution, and a predetermined amount of potassium oleate soap is added to the aqueous solution.
It is obtained by containing lt.

In this way, the inclusion of potassium oleate soap dramatically improves the lubricity that could not be obtained with conventional water-based inks, and as a result, it is possible to make chips with metals such as brass, phosphor bronze, and stainless steel. Not only when it is made of synthetic resin, but also when it is made of synthetic resin, the wear of the ball seat of the tip that the ball comes into contact with during writing is reduced, and the wear of the tip is extremely small, making it an excellent product in the grooves that consume ink. It is possible to maintain the brush feel and smooth loaf flavor.

It is presumed that this effect is achieved because the potassium oleate soap forms a layer between the ball and the ball holder, lowering the coefficient of friction between the tip and the ball and increasing the lubrication effect.

The content of potassium oleate soap is in the range of 0.02 to 5.0% by weight based on the total ink composition.

If the amount is less than 0.022% by weight, the desired lubricity cannot be obtained, while if it exceeds 5.0% by weight, bleeding occurs when writing.

Furthermore, when using a metal ballpoint pen tip, it is desirable to add a rust inhibitor to the ink composition of the present invention in order to prevent corrosion of the tip and increase the stability of the composition over time. . This rust inhibitor can be selected as appropriate depending on the material of the chip, but when using copper alloys such as brass and phosphor bronze, which are the most common materials for chips, benzotriazole is added to the entire composition as a rust inhibitor. On the other hand, sail 05~
It is preferable to add in a range of 0.5 weight ratio.

Effects of the Invention The water-based ink composition for ballpoint pens of the present invention has excellent lubricity, prevents wear between the ball and ball holder, provides a smooth writing feel, and has excellent dye solubility and long-term stability. It also has excellent stability.

Example Next, the present invention will be further explained in detail with reference to Examples.

Sho 111 Water 84
．． 4 weight ratio ethylene glycol 10.0
Score roll 44900 0.1PR-
14 (manufactured by Kao Soap ■) 0.5 The above formulation was stirred at 40 to 60°C for 1 hour, cooled, and then filtered to prepare a water-based ink composition.

Also, for comparison, in the above composition, potassium oleate soap (PR-14)'! Not used for.

A water-based ink composition was prepared in the same manner except that the water content was 84.9% by weight.

500 on a writing tester using these water-based ink compositions.
After m writing 1~, the sinking of the ball and the writing feel were determined, and both compositions were compared. The results are shown in Table 1. Furthermore, the ink composition of the present invention was free from bleeding, had excellent dye solubility, and was excellent in long-term stability.

Example 2 Water 60.8% by weight (polyhydric alcohol) Score roll #900 0.1 (surfactant) Phenol 0.1 OS soap [manufactured by Kao Soap] 1.0 The above formulation was prepared in the same manner as in Example 1. A water-based ink composition of the present invention was prepared.

For comparison, in the above composition, without using potassium oleate soap (OS soap), the total water content was 61%.
．． ．． A water-based ink composition was prepared in the same manner except that the amount was 8% by weight.

500 on a writing tester using these water-based ink compositions.
After writing m, the sinking of the ball and the writing feel were determined and the two compositions were compared. The results are all shown in Table 2. The ink composition of the present invention was free from bleeding, had excellent dye solubility, and had excellent long-term stability.

Claims (1)

[Claims] 1 An ink composition comprising a water-soluble organic solvent and a water-soluble dye further contains 0.02 to 5.0% by weight of potassium oleate soap based on the weight of the entire ink composition. A water-based ink composition for ballpoint pens.