JPH0113505B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a water-based ink composition for writing instruments.
Specifically, water-based ink is used for markers such as felt-tip pens and writing instruments such as water-based ballpoint pens, and is particularly applied to writing instruments with metal parts on the liquid contact surface, and provides effective writing performance without corroding the metal parts. Regarding. As the metal member, copper and copper alloys such as brass, bronze, and nickel silver, aluminum, etc. are used from the viewpoint of workability and economy, and are applied as pen body holding members for markers, tip members for water-based ballpoint pens, or container members. has been done. However, this type of metal member is corrosive,
It is essential to use inks that inhibit corrosion, and inks containing various corrosion inhibitors have been proposed. However, not only is the performance unsatisfactory in terms of corrosion resistance, but the addition of corrosion inhibitors limits the type of dye and reduces the performance as an ink for writing instruments. Not obtained. For example, the
Publication No. 45333 discloses an ink containing benzotriazole as a corrosion inhibitor, but when this ink is applied to a water-based ballpoint pen equipped with a tip member made of a copper alloy, it prevents corrosion of the member over time. This cannot be resolved, and not only does the smooth rotation of the ball become obstructed, but it also causes problems such as discoloration of handwriting. In addition, the degree of corrosion varies greatly depending on the type of dye applied in combination with dyes, such as Brilliant Blue FCF (CI42090),
Supranor Blue-B (CI42645), Brilliant Indocyanine 6B (CI42660), Supranor Cyanine G (CI42655), Brilliant Blue
Triphenylmethane blue dyes such as FFR (CI42735), eosin (CI45380), aciturodamine (CI45100), rose bengal (CI45440),
The degree of corrosion is particularly high for xanthene red dyes such as acidophloxin (CI45410), which poses a practical problem. Furthermore, when an ink containing approximately 2% by weight of benzotriazole is applied to the water-based ballpoint pen, needle-shaped crystals are precipitated on the surface of the metal member after one month at 50°C, impeding smooth ink flow. Not only will it be damaged, but it will also reduce the product value. In addition, there are other defects such as ink oozing or ink splashing from the tip, making it impossible to provide clear handwriting performance. In order to eliminate the defects of the conventional inks described above, the present inventors have conducted various studies and found that it is effective to add an amine salt of methylbenzotriazole. The amine salt of methylbenzotriazole used in the present invention is represented by the following general formula.

[Formula] (In the formula, R ₁ , R ₂ , and R ₃ each represent hydrogen, an alkyl group, or an alkanol group.) These compounds include methylbenzotriazole diethylamine salt, methylbenzotriazole cyclohexylamine salt, methyl Examples include benzotriazole/isopropylamine salt, methylbenzotriazole/morpholine salt, methylbenzotriazole/monoethanolamine salt, methylbenzotriazole/diethanolamine salt, methylbenzotriazole/triethanolamine salt, and the like. In the above, triethanolamine, diethanolamine or monoethanolamine is particularly preferably used as the amine of the amine salt in view of solubility in an aqueous medium, rust prevention effect, etc. When blending these into ink, the effective range of addition is 0.2 to 4.0% by weight, and if it is less than this range, the rust preventive effect on copper alloys will be poor.
On the other hand, if the amount exceeds this range, the dye may change color or cause a precipitate to form over time. The present invention is an ink in which the above-mentioned methylbenzotriazole amine salt, dye, and water are blended as essential components, and each component is dissolved. As a dye, it goes without saying that the above-mentioned triphenylmethane dyes and xanthene dyes, which are difficult to put into practical use because they increase the degree of corrosion when combined with conventional benzotriazole, can be blended effectively without any problems. Conch (CI35255), Nigroshin Black (CI50420), Irgalan Black
GBL (CI Ashido Black 131), Phthalocyanine Blue G (CI74180), Supranor Brylled 3B (CI18130), Newcoccin (C.
I.16255), naphthol yellow S (CI10316), tartrazine (CI19140), etc. are effectively applied. In addition to the above-mentioned essential components, the ink of the present invention may contain the following various components in order to impart suitability as an ink for writing instruments. For example, polyhydric alcohols such as ethylene glycol, diethylene glycol, and glycerin, sulfur-containing agents such as dimethyl sulfoxide, sulfolane, and thiodiethylene glycol are used to suppress evaporation, dye solubility, or improve handwriting performance. In addition, various surfactants are used to improve ink flow, and in water-based ballpoint pen inks, fatty acid metal salts and fatty acid Amine salts, dithiocarbamates, naphthenic acid metal salts, silicone-based activators, fluorine-based activators, phosphate ester-based activators, and the like are used. In addition, for the purpose of improving writing distance or handwriting performance, styrene maleic acid resin,
polyvinylpyrrolidone, polyvinyl alcohol,
Water-soluble resins such as cellulose derivatives, dextrins, and oligosaccharides are used. To prevent mold growth, sodium benzoate, dioxin, carbolic acid, 1:
Sodium salt of 2benziisothiarizon-3-one, etc. are added. Next, an example will be described. Numbers in the following formulations indicate parts by weight. Example 1 Acidophloxin 2.0 Eosin 1.5 Tartrazine 1.0 Ethylene glycol 10.0 Glycerin 5.0 Triethanolamine salt of methylbenzotriazole 2.0 Polyvinylpyrrolidone 0.2 Dioxine 0.1 Water 78.2 The above components were heated to 50 to 60°C and dissolved with stirring for 2 hours. A red ink for a water-based ballpoint pen was obtained. Comparative Example 1 A comparative ink was obtained by replacing the triethanolamine salt of methylbenzotriazole in the formulation of Example 1 with benzotriazole. Example 2 Brilliant Blue FCF 4.0 Acid Dred FB 1.0 Propylene Glycol 5.0 Diethylene Glycol 10.0 Diethanolamine salt of methylbenzotriazole 1.0 Neugen P (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., nonionic activator)
0.3 Water 78.7 The above components were heated to 50 to 60°C and dissolved with stirring for 2 hours to obtain a water-based blue ink for ballpoint pens. Comparative Example 2 A comparative ink was obtained by replacing the diethanolamine salt of methylbenzotriazole in the formulation of Example 2 with benzotriazole. Example 3 Black G Conc 7.0 DMSO 10.0 Thiodiethylene glycol 10.0 Monoethanolamine salt of methylbenzotriazole 1.0 Triethanolamine salt of methylbenzotriazole 2.0 Potassium stearate 0.2 Sodium benzoate 1.0 Water 68.8 Warm the above ingredients to 50-60°C The mixture was stirred and dissolved for 2 hours to obtain a water-based black ink for ballpoint pens. Comparative Example 3 A comparative ink was obtained by replacing the monoethanolamine salt of methylbenzotriazole and the triethanolamine salt of methylbenzotriazole in the formulation of Example 3 with benzotriazole. Example 4 Priliant Blue FCF 2.0 Phthalocyanine Blue G 2.0 Tartrazine 1.0 Propylene Glycol 10.0 DMSO 5.0 Cyclohexylamine salt of methylbenzotriazole 1.0 Water 79.0 The above components were heated to 50 to 60°C and dissolved with stirring for 2 hours to prepare a water-based ballpoint pen. I got green ink. Comparative Example 4 A comparative ink was obtained by replacing the monoethanolamine salt of methylbenzotriazole in the formulation of Example 4 with benzotriazole. The inks of Examples 1 to 4 and Comparative Examples 1 to 4 were used as samples for the following corrosion test and ink popping test. A. Explanation of test method (1) Corrosion test Sample ink was collected in a commercially available 30 c.c. glass bottle, a brass ballpoint pen tip was put into the ink, and after the bottle was tightly capped, it was left in a constant temperature bath at 80℃ for 30 days. Remove the chip and observe the state of the metal surface using a metallurgical microscope. (2) Corrosion test For the sample ink, fill a commercially available water-based ballpoint pen with a brass tip with an appropriate amount of ink and use it as a product. After making continuous circles on commercially available report paper and confirming that the writing was in good condition, it was left in a constant temperature bath at 40℃ for 3 months.
Check the writing condition of each sample,
Observe the corrosion status of the chip surface using a metallurgical microscope. (3) Ink popping test Regarding the sample ink, after filling an appropriate amount of ink into a commercially available water-based ballpoint pen using a brass tip, it was left in an inverted position (downward writing position) for 30 minutes.
After leaving it for a minute, remove the cap and observe whether ink is coming out from the tip. B Test results The results of the corrosion test are shown in Table-1.
The results of the ink popping test are shown in Table 2.

[Table] Judgment Criteria (1) Observation of chip surface condition ◎; Good metallic luster, no corrosion observed at all. ○: Metallic luster has weakened, but there is no corrosion. △; Metallic luster is dull, and there is partial corrosion on the metal surface. ×: No metallic luster, corrosion was observed on the metal surface, and needle-shaped crystals were precipitated. (2) Observation of writing condition ◎; Writing condition is good. ○: The initial color tone may become lighter in some cases, but the writing condition is generally good. Δ: There is an initial fading phenomenon, and there is some directionality. ×; Brush feel is rough, lines are broken, and directionality occurs frequently.

[Table] As seen in the above test results, the ink of the example of the present invention has significantly superior performance compared to the ink of the comparative example, and is put into practical use. Note that the example inks relate to water-based ballpoint pen inks,
The ink of the present invention can be effectively used in various writing instruments that include a metal member on the liquid contact surface.

Claims (1)

[Claims] 1. Contains a dye, an amine salt of methylbenzotriazole, and water as essential components, and the amine salt of methylbenzotriazole is present in an amount of 0.2 to 4.0 in the ink.
A water-based ink composition for writing instruments that is formulated in a proportion of % by weight. 2. The aqueous ink composition for writing instruments according to claim 1, wherein the amine of the amine salt of methylbenzotriazole is triethanolamine, diethanolamine or monoethanolamine.