JPH0841409A - Aqueous ink composition for ballpoint pens - Google Patents

Abstract

PURPOSE:To provide an ink composition for water-based ball point pen, containing a benzothiazole compound, a colorant and water, capable of being stored for a long period without causing corrosion of a pen point and making it possible to write smoothly. CONSTITUTION:This ink composition for water-based ball point pen contains (A) preferably 0.1 to 10.0wt.% benzothiazole compound represented by formula I or II (R' and R'' are each H or methyl), (B) preferably 0.5 to 30wt.% colorant such as a direct dye and (C) preferably 40 to 90wt.% water. In addition, the water-based ball point pen used in this case is preferably equipped with a tip holder made of a material such as stainless steel and a pen point having a sintered hard alloy ball.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ballpoint pen ink and a water-based ballpoint pen. Specifically, it relates to improvement of the corrosion resistance of the pen tip of a ballpoint pen.

[0002]

2. Description of the Related Art Cemented carbide is used for a metal member of a ball used for a pen tip of an aqueous ball-point pen. Cemented Carbide is a powder of carbide of a metal of group IVa, Va, VIa of the periodic table of elements Fe,
WC, which is an alloy of Co and Ni that are sintered and bonded by an iron group metal.
-Co type and WC-TiC-Ta (Nb) C-Co type. When this metal member is used, there is a problem that the metal member is corroded due to a corrosive component contained in the ink and writing becomes impossible. For the purpose of improving such a problem, Cr ₃ C ₂ is added to the cemented carbide ball used for the pen tip. Further, Japanese Patent Publication No. 49-45333 discloses an ink containing benzotriazole as a corrosion inhibitor. However, Cr is added to the cemented carbide ball
_{Even if 3} C ₂ is added or benzotriazole is added to the ink, the corrosion resistance is not sufficient, and the problem that writing becomes impossible when stored for a long time has not been solved.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink for water-based ballpoint pens that does not corrode the nib even when stored for a long period of time and maintains a high writability level.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, by incorporating a benzothiadiazole compound into an ink composition,
It has been found that the above-mentioned object is achieved, and the present invention has been completed based on this finding.

The aqueous ink composition for a ballpoint pen of the present invention is characterized by containing a benzothiadiazole compound, a colorant and water. Preferably, the composition comprises 0.1 to 10.0% by weight of the benzothiadiazole compound, 0.5 to 30% by weight of colorant, and 40 to 90% by weight of water.
This is an aqueous ink composition for a water-based ballpoint pen.

The aqueous ballpoint pen of the present invention comprises an ink container filled with an aqueous ballpoint pen ink containing a benzothiadiazole compound, a colorant and water, a chip holder made of at least one material selected from stainless steel, brass and nickel silver, And a nib having a cemented carbide ball.

Examples of the benzothiadiazole compound used in the ink composition of the present invention include compounds of the formula:

Embedded image (However, R'is hydrogen or a methyl group) benzothiadiazole [when R'is hydrogen, benzo-1,
2,5-thiadiazole], the formula

Embedded image (However, R ″ is hydrogen or a methyl group), benzothiadiazole [when R ″ is hydrogen, benzo-1,
2,3-thiadiazole] can be shown. The content of the benzothiadiazole compound is preferably 0.1 to 10.0% by weight of the total composition, more preferably 0.1 to 5.0% by weight. If it is 0.1% by weight or less, sufficient corrosion resistance cannot be obtained, and if it is 10.0% by weight or more, a precipitate is generated over time, which is unsuitable.

A water-soluble organic solvent may be used in the ink composition of the present invention. Examples of the solvent include water-soluble polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerin, cellosolves such as ethylene glycol monomethyl ether (methyl cellsolve), ethylene glycol monoethyl ether (ethyl cellosolve), and diethylene glycol monomethyl ether ( Carbitols such as methyl carbitol) and diethylene glycol monoethyl ether (ethyl carbitol),
Examples thereof include glycol ether esters such as ethylene glycol monoethyl ether acetate.
These solvents have the effect of improving the non-drying property.
The content is usually 40% by weight or less, preferably 5 to 40% by weight, based on the entire composition. 40% by weight
If it exceeds the limit, the ink will be lined up when writing on paper and it will be difficult to dry, which is not preferable.

The colorants used in the ink composition of the present invention are pigments and water-soluble dyes. The type of pigment is not particularly limited, and any one of inorganic and organic pigments conventionally used in water-based ink compositions can be used. The inorganic pigments include, for example, titanium oxide, carbon black, metal powder, and the like, and the organic pigments include, for example, azo lake, insoluble azo pigment, chelate azo pigment, phthalocyanine pigment, perylene and perinone pigment, anthraquinone pigment, quinacridone pigment. , Dye lakes, nitro pigments, nitroso pigments and the like. Specifically, phthalocyanine blue (C.
I. 74160), phthalocyanine green (C.I.
74260), Hansa Yellow 3G (C.I. 1167)
0), disazo yellow GR (C.I. 21100), permanent red 4R (C.I. 12335), brilliant carmine 6B (C.I. 15850), quinacridone red (C.I. 46500) and the like can be used.

As the water-soluble dye, any of a direct dye, an acid dye, an edible dye and a basic dye can be used. An example of a direct dye is described below. C. I. Direct Black 17, the same 19, the same 22, the same 32, the same 38, the same 51,
71, C.I. I. Direct Yellow 4, the same 26, the same 4
4, 50, C.I. I. Direct Red 1, same 4, same 2
3, ibid 31, ibid 37, ibid 39, ibid 75, ibid 80, ibid 8
1, the same 83, the same 225, the same 226, the same 227, C.I. I.
Direct Blue 1, 1, 15, 71, 86, 10
6, 119, and the like. An example of the acid dye will be described below. C. I. Acid black 1, same 2, same 2
4, the same 26, the same 31, the same 52, the same 107, the same 109, the same 110, the same 119, the same 154, C.I. I. Acid Yellow 7, Same 17, Same 19, Same 23, Same 25, Same 29, Same 3
8, ibid 42, ibid 49, ibid 61, ibid 72, ibid 78, ibid 11
0, 141, 127, 135, 142, C.I.
I. Acid Red 8, the same 9, the same 14, the same 18, the same 2
6, 27, 35, 37, 51, 52, 5
7, ibid 82, ibid 87, ibid 92, ibid 94, ibid 111, ibid 1
29, 131, 138, 186, 249, 2
54, 265, 276, C.I. I. Acid Violet 15, 17, 17, C.I. I. Acid Blue 1, 7
Ibid 9, ibid 15, ibid 22, ibid 23, ibid 25, ibid 40, ibid 4
1, the same 43, the same 62, the same 78, the same 83, the same 90, the same 9
3, 103, 112, 113, 158, C.I.
I. Acid Green 3, 9th, 16th, 25th, 2nd
7 and the like. Most of the food dyes are contained in the direct dyes or the acid dyes. I. Food Yellow 3 can be mentioned. An example of the basic dye will be described below. C. I. Basic Yellow 1, 2, 2, 21, C.I. I. Basic Orange 2, the same 14, the same 32, C.I. I. Basic Red 1, the same 2, the same 9, the same 14, C.I. I. Basic Violet 1, Same 3, Same 7, C.I. I. Basic Green 4, C.I. I. Basic Brown 12, C.I. I. Basic Black 2, 8 and the like.

These colorants may be used alone or in combination of two or more, and their content in the entire composition is usually 0.5 to 30% by weight, preferably 1 to 30% by weight. It is in the range of 15% by weight. If it is stored for a long period of time even if it exceeds 30% by weight, the pigment may agglomerate or the dye may be deposited on the pen tip, causing writing failure.
If it is less than 0.5%, the coloring becomes low and the hue when written on a paper becomes unclear, which is not preferable.

When a pigment is used as a colorant, it is necessary to use a dispersant. This dispersant has a function of adsorbing to the surface of the pigment particles to disperse the pigment in water, and a nonion, an anionic surfactant or a water-soluble polymer is used. Water-soluble polymers are preferably used.

As the nonionic surfactant, there are polyoxyalkylene higher fatty acid ester, higher fatty acid partial ester of polyhydric alcohol, higher fatty acid ester of sugar, and the like. Specifically, fatty acid ester of glycerin, polyglycerin fatty acid ester, Propylene glycol fatty acid ester, pentaerythritol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene phytosterol, polyoxy Ethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene castor oil Polyoxyethylene lanolin, polyoxyethylene lanolin alcohols, polyoxyethylene alkyl amines, polyoxyethylene fatty acid amides,
Examples include polyoxyethylene alkylphenyl formaldehyde condensates.

Examples of the anionic surfactant include alkylated sulfonates of higher fatty acid amides and alkylallyl sulfonates, and specifically, alkyl sulfates, polyoxyethylene alkyl ether sulfates, N-
Acyl amino acid salts, N-acyl methyl taurine salts, polyoxyethylene alkyl ether acetates, alkyl phosphates, polyoxyethylene alkyl ether phosphates and the like.

As the water-soluble polymer, polyacrylic acid,
There are acrylic acid copolymers, maleic acid resins, and the like. Specifically, a resin such as an acrylic resin, a styrene acrylic acid resin, or a styrene maleic acid resin made into a salt form to be water-soluble is used. The alkali metal forming a salt is typically sodium or potassium, and the amine is an aliphatic primary to tertiary amine such as mono-, di- or tri-methylamine, mono-, di- or tri-amine. Typical examples are alcohol amines such as propanolamine, methylethanolamine, methylpropanolamine and dimethyletheramine, as well as ammonia, molyphorin and N-methylphorine. The content of the dispersant is usually 0.1 to 10% by weight in the composition.

The water used in the composition of the present invention is not particularly limited, but 40 to 90% by weight in the composition is desirable. If it is less than 40%, the amount of the relative solvent and the colorant increases, so it is difficult to volatilize,
When writing on paper, the ink becomes difficult to dry,
If it exceeds 0%, it will easily volatilize and the pen tip will dry,
It is not preferable because it causes poor writing.

In addition to the above, the composition of the present invention may contain a lubricant, a preservative, and a pH adjusting agent, if necessary. Examples of the lubricant include fatty acid salts such as potassium linoleate, sodium ricinoleate, potassium oleate, and sodium oleate, and the surfactants mentioned as the dispersant. As a preservative, phenol, isopropylmethylphenol, sodium pentachlorophenol, benzoic acid, sodium benzoate, dehydroacetic acid, sodium dehydroacetate, sorbic acid, potassium sorbate, 2-pyridinethiol-1 oxide sodium salt, 1,2-benz Isothiazoline-3-
On, 5-chloro-2-methyl-4-isothiazoline-
3-one, 2,4-thiazolylbenzimidazole, paraoxybenzoic acid ester and the like, amines or bases as pH adjusters, for example, various organic amines such as triethanolamine, monoethanolamine and diethanolamine, sodium hydroxide, and hydroxide. Inorganic alkaline agents of hydroxides of alkali metals such as lithium and potassium hydroxide, ammonia, etc. can be mentioned.

The ballpoint pen of the present invention includes a batting system,
The direct current method can be used. The batting type ball-point pen is composed of a barrel containing the batting that has absorbed the ink of the present invention, a relay core made of fiber bundles connected to the batting, a pen tip made of a ball and a tip holder, and the like. In addition, the direct current type ball-point pen is an ink tank for directly storing the ink of the present invention, and when the air in the ink tank expands due to a temperature rise, the ink pushed out from the ink tank drops from the pen tip or air hole. It is composed of an ink reservoir that retains temporarily so as not to prevent it, a ball, and a pen tip including a tip holder.

[0019]

The water-based ink composition of the present invention has excellent corrosion resistance of the pen tip, does not corrode even after long-term storage, and can maintain a high writability level. Although its detailed mechanism of action is not clear, when a benzothiadiazole compound undergoes a corrosion reaction on the metal surface to form a metal ion, the metal ion reacts with the benzothiadiazole compound, and the resulting film has a rust preventive effect. It is speculated that the coating film has the property of preventing corrosion from progressing and has the same effect on the metal composition used for the pen tip.

[0020]

EXAMPLES The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. The evaluation of the inks obtained in the respective examples and comparative examples was carried out by the judgments of the following corrosion resistance tests 1 and 2. Table 2 shows the results.

Corrosion resistance test 1: 5 g of ink was put in a test tube, 5 pieces of cemented carbide balls as a writing part of a ballpoint pen and 5 holders holding the same were immersed in the test tube, and then capped at 70 ° C. It was left for 30 days. Then, the temperature was returned to room temperature, and the surfaces of the ball and the holder were observed with an optical microscope. ◯: Has good metallic luster and no corrosion is observed. Δ: The metallic luster is weakened and slight corrosion is observed. ▲: The metallic luster is dull, and partial corrosion is observed on the metal surface. X: No metallic luster and corrosion is observed on the entire metal surface. In addition, a pen tip was assembled using the ball and the holder, an aqueous ballpoint pen was assembled, and the writing feeling was examined. The ink used was one in which each ball and holder were dipped. The writing feeling was judged according to the following criteria by drawing a spiral of about 1.5 cm in height 10 times. ◯: Smooth and stable writing quality Δ: Rugged and hard writing quality ×: Rugged and hard writing quality, and line cutting and directionality.

Corrosion resistance test 2: A ball-point pen was filled with a predetermined ink, and a water-based ball-point pen was assembled using a cemented carbide ball, which is the writing part of the ball-point pen, and a holder holding it, and left standing sideways at room temperature for 360 days. The chip surface was observed with an optical microscope. ◯: Has good metallic luster and no corrosion is observed. Δ: The metallic luster is weakened and slight corrosion is observed. ▲: The metallic luster is dull, and partial corrosion is observed on the metal surface. X: No metallic luster and corrosion is observed on the entire metal surface. In addition, I examined the writing feeling. The writing feeling was judged according to the following criteria by drawing a spiral of about 1.5 cm in height 10 times. ◯: Smooth and stable writing quality Δ: Rugged and hard writing quality ×: Rugged and hard writing quality, and line cutting and directionality.

Example A (Ink A) A black water-based ballpoint pen pigment ink was prepared with the following formulation. Each component was stirred and mixed for 3 hours with a stirrer, dispersed for 5 hours with a side mill, and further obtained by removing coarse particles with a centrifuge. Pigment: Carbon black ("Carbon Black MA100" manufactured by Mitsubishi Kasei Co., Ltd.) 8.0 wt% Solvent: Glycerin 10.0 Solvent: Ethylene glycol 5.0 Dispersant: Styrene acrylic acid resin ammonium salt 3.0 Lubricant: Potassium oleate 0.3 pH adjuster: triethanolamine 0.5 Preservative: 1,2-benzisothiazolin-3-one ("Proxel BDN" manufactured by Zeneca Corp.) 0.1 Rust inhibitor: benzo-1, 2,5-Thiadiazole 0.2 Purified water: 72.9 Total 100.0

Example B (Ink B) A blue water-based ballpoint pen pigment ink having the following composition was prepared in Example A.
It was prepared in the same manner as described above. Pigment: Phthalocyanine Blue (“Chromofine Blue 4965” manufactured by Dainichiseika Co., Ltd.) 8.0% by weight Solvent: Glycerin 10.0 Solvent: Propylene glycol 7.0 Dispersant: Styrene maleic acid resin ammonium salt 3.0 Lubricant : Potassium linoleate 0.5 pH adjuster: triethanolamine 0.7 Preservative: 1,2-benzisothiazolin-3-one ("Proxel BDN" manufactured by Zeneca KK 0.1) Antirust agent: benzo-1 , 2,5-thiadiazole 0.2 Purified water: 70.5 Total 100.0

Example C (Ink C) A black ballpoint pen dye ink was prepared with the following composition. Each component was stirred at 40 to 60 ° C. for 1 hour, cooled, and then filtered. Dye: C.I. I. Direct Black # 19 5.0 wt% Solvent: Ethylene glycol 15.0 Lubricant: Potassium linoleate 0.3 pH adjuster: Triethanolamine 0.5 Preservative: 1,2-benzisothiazolin-3-one (Zeneca "Proxel BDN" 0.1 rust preventive agent: benzo-1,2,5-thiadiazole 0.2 purified water: 78.9 total 100.0

Comparative Example D (Ink D) A black aqueous ballpoint pen pigment ink was obtained in the same manner as Ink A except that benzo-1,2,5-thiadiazole was removed from Ink A and the amount of water was added.

Comparative Example E (Ink E) A blue water-based ballpoint pen pigment ink was obtained in the same manner as Ink B except that benzo-1,2,5-thiadiazole was removed from Ink B and the amount of benzotriazole was added.

Comparative Example F (Ink F) A black aqueous ballpoint pen dye ink was obtained in the same manner as Ink C except that benzo-1,2,5-thiadiazole was removed from Ink C and the amount of water was added.

Examples 1 to 12 and Comparative Examples 1 to 12 Filling a predetermined ink (Table 1) in a batting housed in a barrel, and Table 1 shows the material of the ball (diameter 0.5 mm) of the chip and the holder. An aqueous ballpoint pen was assembled instead as shown.
The results of the corrosion resistance test are shown in Table 2.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

EFFECTS OF THE INVENTION The bow pen using the ink for water-based ballpoint pen of the present invention does not cause corrosion on the pen tip even after long-term storage,
It is possible to maintain a high writability level.

Claims (4)

[Claims] 1. A benzothiadiazole compound, a colorant,
An aqueous ink composition for a ballpoint pen, which contains water. 2. The benzothiadiazole compound is contained in an amount of 0.1 to 10.0% by weight of the total composition.
The water-based ballpoint pen ink composition as described above. 3. A composition comprising 0.1 to 10.0% by weight of a benzothiadiazole compound, 0.5 to 30% by weight of a colorant, and 40 to 90% by weight of water.
The water-based ballpoint pen ink composition as described above. 4. A container tube containing an ink for a water-based ballpoint pen containing a benzothiadiazole compound, a colorant and water, a chip holder made of at least one material selected from stainless steel, brass and nickel silver, and a cemented carbide ball. A water-based ballpoint pen having a nib having.