JPH0641489A - Water-base ink composition for ballpoint pen - Google Patents

Abstract

PURPOSE:To provide the ink compsn. which is excellent in lubricity and causes no blur of written lines by incorporating 1-(2',3'-dihydroxypropyl)benzotriazole into the compsn. CONSTITUTION:The compsn. comprises water, a colorant, a water-sol. org. solvent, and 1-(2',3'-dihydroxypropyl)benzotriazole in an amt. of about 0.01-5.0wt.% of the compsn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink composition for ballpoint pens, which has excellent lubricity, good writing quality, and less blurring of writing lines.

[0002]

2. Description of the Related Art A conventional water-based ink composition for ballpoint pens contains water, a colorant, and a water-soluble organic solvent such as a polyhydric alcohol or a derivative thereof as main components.
Further, an aqueous ink composition for a ballpoint pen, which further contains a lubricant such as a fatty acid or a salt thereof, has been known for the purpose of enhancing lubricity and improving writing quality.

[0003]

However, generally, when the lubricity of a water-based ink composition for a ballpoint pen is increased, there is a tendency that a writing line is easily blurred, so that it is necessary to improve the lubricity and prevent the writing line from spreading. It was difficult to make them compatible. The present invention is intended to solve the above problems in the prior art, and an object thereof is to provide a water-based ink composition for a ballpoint pen which has excellent lubricity and does not cause bleeding of a writing line.

[0004]

As a result of various studies to achieve the above object, the present inventors have found that 1- (2 ', 3'-dihydroxypropyl) benzo was added to an aqueous ink composition for ballpoint pens. By containing triazole,
The inventors have found that the improvement of lubricity and the prevention of bleeding of writing lines are both solved, and have completed the present invention.

That is, the water-based ink composition for a ball-point pen of the present invention is a 1- (2 ', 1- (2',
It is characterized by containing 3'-dihydroxypropyl) benzotriazole.

In the ink composition of the present invention, 1-
The compounding ratio of (2 ', 3'-dihydroxypropyl) benzotriazole is 0.01 to 5.0% by weight, preferably 0.1 to 2.0% by weight in the ink composition. When the compounding ratio is less than 0.01% by weight, the lubricity is not maintained for a long time, and when the compounding ratio exceeds 5.0% by weight, the performance is not further improved.

The water used in the ink composition of the present invention is not particularly limited, and its compounding ratio is not particularly limited, and is preferably 40 to 90% by weight in the ink composition. Is.

The colorant used in the ink composition of the present invention may be one used in general water-soluble ink compositions, and examples thereof include dyes such as acid dyes, direct dyes, and basic dyes. Alternatively, they may be selected from pigments such as inorganic pigments and organic pigments, and may be used alone or in combination of several kinds. The compounding ratio of these colorants varies depending on the types of dyes and pigments and the purpose of use, but is usually 1 to 15% by weight in the ink composition.

The water-soluble organic solvent used in the ink composition of the present invention is added for the purpose of preventing dryness and imparting antifreeze, and is a conventionally known non-drying water-soluble organic solvent, for example,
Polyhydric alcohols such as ethylene glycol, diethylene glycol and glycerin, glycol ethers such as methyl cellosolve and butyl cellosolve, glycol esters such as ethylene glycol monomethyl ether acetate, etc. are appropriately selected and used alone or in combination of two or more kinds. Can be added. The mixing ratio of these water-soluble organic solvents is 5 in the ink composition.
˜50 wt%, preferably 10-35 wt%.

If necessary, the ink composition of the present invention is conventionally used in water-based ink compositions such as preservatives, mildew-proofing agents, pH adjusting agents, rust-preventing agents, and various surfactants. It is also possible to include an auxiliary agent.

[0011]

The action of 1- (2 ', 3'-dihydroxypropyl) benzotriazole described above is not clear, but when this substance is contained in an aqueous ink composition for a ballpoint pen, it has the property of adsorbing to the metal surface of this substance. It is considered that this contributes to the improvement of lubricity and the difficulty of blurring the drawn lines. This point will be described in more detail in Comparative Examples and the like described later.

[0012]

EXAMPLES Hereinafter, the ink composition of the present invention will be described with reference to Examples and Comparative Examples. The ink compositions obtained in Examples and Comparative Examples were filled in ball-point pens under the same conditions, and the following tests were conducted. Ball sinking amount: The ball sinking amount (μm) was measured after writing for 500 m with a writing tester. Drawing line width: The width (mm) of the drawing line was measured after writing 500 m with a writing tester. Writing sensation: A circle with a diameter of 2 to 3 cm was drawn around 20 times by hand before and after writing with a writing tester, and the writing sensation at that time was evaluated as “smooth” or “squeaky”. Deterioration with time: After leaving it in a constant temperature bath of 40 ° C. for 60 days, a circle with a diameter of 2 to 3 cm was drawn around 20 times by handwriting, and the writing feeling at that time was evaluated as “smooth” or “squeaky”.

Example 1 Water 65.3 parts by weight Propylene glycol 24.0 parts by weight Polyoxyethylene alkylallyl ether 0.2 parts by weight Phenol 0.1 parts by weight Benzotriazole 0.1 parts by weight 1- (2 ', 3 ′ -Dihydroxypropyl) benzotriazole 0.3 parts by weight Black dye (CI Direct Black # 19) 10.0 parts by weight With the above composition, the mixture is stirred at 40 to 60 ° C. for 1 hour, cooled, and then filtered. To obtain a water-based black ink composition for a ballpoint pen. The test results are shown in Table 1. Comparative Example 1 A water-based black ink composition was obtained by removing 1- (2 ', 3'-dihydroxypropyl) benzotriazole and replacing it with a water content of 65.6 parts by weight. It was The test results are shown in Table 1.

Example 2 Water 74.2 parts by weight Glycerin 20.0 parts by weight Polyoxyethylene alkylallyl ether 0.2 parts by weight Phenol 0.1 parts by weight 1- (2 ', 3'-dihydroxypropyl) benzotriazole 0 .1 part by weight Blue dye (Edible Blue No. 1) 5.4 parts by weight The same procedure as in Example 1 was carried out with the above composition to obtain an aqueous blue ink composition for a ballpoint pen. The test results are shown in Table 1. Comparative Example 2 Except for 1- (2 ′, 3′-dihydroxypropyl) benzotriazole, potassium oleate soap was replaced with 0.3 parts by weight, and the amount of water was 74.0 parts by weight. A water-based blue ink composition was obtained in the same manner as described above. The test results are shown in Table 1.

Example 3 Water 65.4 parts by weight Ethylene glycol 28.0 parts by weight Phenol 0.1 parts by weight Benzotriazole 0.1 parts by weight 1- (2 ', 3'-dihydroxypropyl) benzotriazole 0.1 parts by weight Parts Red Dye (Edible Red No. 102) 6.3 parts by weight The same procedure as in Example 1 was carried out with the above composition to give an aqueous red ink composition for ballpoint pens. The test results are shown in Table 1. Comparative Example 3 A water-based red ink composition was obtained by removing 1- (2 ', 3'-dihydroxypropyl) benzotriazole and replacing it with a water content of 65.5 parts by weight. It was The test results are shown in Table 1.

Example 4 Water 63.8 parts by weight Ethylene glycol 28.0 parts by weight 1- (2 ', 3'-dihydroxypropyl) benzotriazole 0.2 parts by weight Styrene acrylate resin 3.0 parts by weight Carbon black [ MA100, manufactured by Mitsubishi Kasei Co., Ltd.] 5.0 parts by weight The concentrated dispersion having the above composition is premixed, and then subjected to a dispersion treatment for 2 hours by a vertical sand mill, and then diluted with water to obtain the above composition. To obtain a water-based pigment black ink composition for ballpoint pens. The test results are shown in Table 1. Comparative Example 4 A water-based pigment was prepared in the same manner as in Example 4 except that 1- (2 ', 3'-dihydroxypropyl) benzotriazole was removed and sodium oleate soap was added in an amount of 0.2 part by weight. A black ink composition was obtained. The test results are shown in Table 1.

[0017]

[Table 1]

As is apparent from Table 1 above, Example 1
The ink compositions of Nos. 4 to 4 are Comparative Examples 1 to 4, respectively, which serve as controls.
The amount of ball sinking is smaller than that of the ink composition of No. 4, there is no change in the writing line width over time, and the writing feeling is excellent and there is no deterioration over time. Therefore, the water-based ink composition for a ball-point pen of the present invention containing 1- (2 ', 3'-dihydroxypropyl) benzotriazole has a smoother writing feel than the conventional ink composition and has less ball sinkage. Therefore, it has excellent lubricity. Further, the ink composition of the present invention has an effect of preventing bleeding because the width of the writing line does not change with time,
Furthermore, deterioration over time is prevented.

[0019]

According to the present invention, it is possible to solve the conventional problem of simultaneously improving the lubricity of a water-based ink composition for ballpoint pens and preventing the blurring of writing lines, and prevent the ink composition from deteriorating over time. it can. In addition, the ballpoint pen using the ink composition for a ballpoint pen of the present invention has the advantage that the writing quality is good and a clear writing line is obtained. Furthermore, since the amount of sinking of the ball is small, the wear of the ball seat in the ball holder that holds the ball is reduced, and the durability of the ball holder and the like is improved, which is an additional advantage.

Claims (1)

[Claims] 1. A water-based ink composition for a ballpoint pen, which comprises water, a colorant and a water-soluble organic solvent, 1- (2 ',
A water-based ink composition for ballpoint pens, which comprises 3'-dihydroxypropyl) benzotriazole.