JPH07247458A - Pigment ink composition for aqueous ball point pen - Google Patents

Abstract

PURPOSE:To obtain the subject ink composition containing (di)glycerol monomethyl ether, a pigment, a dispersant and water, reduced in blur of a written character and capable of reducing abrasion of a ball holder and remarkably improving writing performance because of its excellent smoothness. CONSTITUTION:This ink composition contains (A) an ether selected from (di) glycerol monomethyl ethers (B) a pigment, (C) a dispersant (preferably a water- soluble polymer such as a polyacrylic acid salt) and (D) water, preferably in a ratio of 1 to 30wt.% component (A), 5 to 15wt.% component (B), 0.1 to 10wt.% component (C) and 40 to 90wt.% component (D), respectively based on the whole composition. In addition, the component (A) is recommendably used in the form of a mixture with a water-soluble organic solvent such as ethylene glycol capable of improving non-drying properties. In this case, the content of the water-soluble organic solvent is preferably 5 to 40wt.% based on the whole composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pigment ink composition for water-based ballpoint pens.

[0002]

2. Description of the Related Art Conventional aqueous pigment inks for ballpoint pens are
In addition to water, a water-soluble solvent such as glycol or glycerin is used as a main component solvent in order to suppress ink drying at the pen tip (non-drying property), and a pigment is dispersed as a colorant. However, if it is left as it is, the lubricity is poor, and the friction resistance between the ball and the seat of the ball increases when the ball rotates during writing, causing rattling of the ball and uneven outflow of ink. There is a drawback that the property significantly decreases. For the purpose of improving such drawbacks, it has been attempted to add a lubricity improver such as unsaturated fatty acid or potassium oleate. However, with such a method, sufficient lubricity cannot be obtained, an unreadable phenomenon occurs due to wear of the ball seat, and even if sufficient lubricity is obtained, the surface tension of the ink is reduced. Was significantly reduced, and there was a practical problem such that the handwriting was likely to bleed.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to prevent the surface tension from being extremely lowered, so that the handwriting is less likely to bleed, and to have sufficient lubricity so that the ball seat is worn by smooth ball rotation. The present invention intends to provide a pigment ink for water-based ballpoint pens, which has a significantly improved non-drying property while providing a comfortable writing feeling while remarkably improving the writing performance.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has achieved the above-mentioned object by adding glycerin monomethyl ether or diglycerin monomethyl ether to a pigment ink composition. The inventors have found what can be achieved and have completed the present invention based on this finding.

The aqueous pigment ink composition for a ballpoint pen of the present invention is characterized by containing at least one ether selected from the group consisting of glycerin monomethyl ether and diglycerin monomethyl ether, a pigment, a dispersant, and water. The ether content is preferably 0.5 to 40% by weight of the total composition, more preferably 1
~ 30% by weight.

A first aqueous pigment ink composition for a ball-point pen of the present invention is characterized by containing a pigment, a dispersant, water, and glycerin monomethyl ether. Preferably, glycerin monomethyl ether is added to 0.5% of the total composition.
-40% by weight, pigment 2-30% by weight of the composition, dispersant 0.1-10% by weight of the composition, and water 40-90.
It is an aqueous pigment ink composition for a ball-point pen, which is contained by weight%.

The second aqueous pigment ink composition for a ball-point pen of the present invention is characterized by containing a pigment, a dispersant, water, and diglycerin monomethyl ether. Preferably, diglycerin monomethyl ether is 0.5 to 40% by weight of the total composition amount, the pigment is 2 to 30% by weight of the composition,
Dispersant is 0.1-10% by weight of the composition, and water is 40%.
It is a pigment ink composition for water-based ballpoint pens containing about 90% by weight.

The ether used in the ink composition of the present invention is at least one ether selected from the group consisting of glycerin monomethyl ether and diglycerin monomethyl ether, and the content thereof is 0.5 to 40 of the total composition. % By weight is preferable, but more preferably 1 to
It is 30% by weight. If it is 0.5% by weight or less, sufficient lubricity cannot be obtained and improvement in writing performance cannot be expected, and if it is 40% by weight or more, the viscosity of the ink becomes high and the outflow deteriorates, which is not suitable.

The ether used in the ink composition of the present invention may be mixed with a water-soluble organic solvent. 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 ( Examples thereof include carbitols such as methyl carbitol) and diethylene glycol monoethyl ether (ethyl carbitol), glycol ether esters such as ethylene glycol monoethyl ether acetate. These improve the non-drying property. In addition, the content is based on the total composition,
It is usually 40% by weight or less, preferably 5 to 40% by weight.

The type of pigment used in the ink composition of the present invention is not particularly limited, and any of inorganic and organic pigments commonly used in aqueous pigment ink compositions can be used. . As an inorganic pigment,
Examples thereof include titanium oxide, carbon black, and metal powder. Examples of organic pigments include azo lake,
Examples thereof include insoluble azo pigments, chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dye lakes, nitro pigments and nitroso pigments. Specifically, phthalocyanine blue (CI.74160), phthalocyanine green (CI.74260), Hansa Yellow 3G
(C.I. 11670), Disazo Yellow GR (C.I.
I. 21100), Permanent Red 4R (C.I.
12335), Brilliant Carmine 6B (C.I.
5850), quinacridone red (C.I. 4650)
0) etc. can be used. These pigments may be used alone or in combination of two or more, and the content thereof is usually 2 to 5 based on the weight of the entire composition.
30% by weight, preferably 5 to 15% by weight.

The dispersant in the composition of the present invention is used to disperse the pigment in water by adsorbing it on the surface of the pigment particles, and nonionic, anionic surfactant or water-soluble polymer is used. To be A water-soluble polymer is preferably used. Nonionic surfactants include polyoxyalkylene higher fatty acid esters, higher fatty acid partial esters of polyhydric alcohols, higher fatty acid esters of sugars, and the like. Specifically, fatty acid esters of glycerin, polyglycerin fatty acid esters, 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, polyoxyethylene polyoxy Propylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene castor oil, polyoxy Chirenranorin, 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 salts, 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 resin, or a styrene maleic acid resin in the form of a salt to be water-soluble is used. As the alkali metal forming a salt, sodium and potassium are typical, and as the amine, an aliphatic primary primary such as mono-, di- or tri-methylamine is used.
Typical examples are tertiary amines, alcohol amines such as tertiary amines, mono-, di- or tri-propanolamines, methylethanolamine, methylpropanolamine and dimethylethanolamine, and ammonia, morpholine and N-methylphorine. The content of the dispersant is 0.1 to 10% by weight in the composition.

The content of water used in the composition of the present invention is not particularly limited, but is preferably 40 to 90%.

In addition to the above, in the ink composition of the present invention, as a lubricant, potassium linoleate, sodium ricinoleate, potassium oleate, sodium oleate, etc. may be used, and as a preservative, phenol, sodium benzoate, benzoisothiazoline may be used. In addition, benzotriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, etc. may be contained as a rust preventive, and triethanolamine, monoethanolamine, diethanolamine, ammonia, etc. may be contained as a pH adjusting agent.

[0016]

The water-based ink composition of the present invention has excellent lubricity and improves writing performance. Although its detailed mechanism of action is not clear, glycerin monomethyl ether used in the present invention, a hydroxyl group in the structure of diglycerin monomethyl ether, and oxygen at the ether bond show an adsorption action on the metal surface, and Hydrocarbon chains are lined up on the opposite side. Therefore, it is presumed that the viscosity of glycerin monomethyl ether and diglycerin monomethyl ether itself gives a lubricity by forming a lubricating film between the balls and the seats of the balls. Further, due to the influence of the dispersant, it is considered that when used in a ballpoint pen, there is little bleeding and good lubricity can be obtained.

[0017]

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 inks of Examples and Comparative Examples were obtained by stirring and mixing each component for 3 hours with a stirrer, dispersing them with a sand mill for 5 hours, and further removing coarse particles with a centrifuge. The inks obtained in each of the examples and comparative examples were evaluated by the following writing test. The results are shown in Table 1.

The ball sinking measurement method in the written test is as follows. Ball sinking: 500m under the conditions of a writing angle of 60 degrees, a writing speed of 5.5m / min, and a load of 100g using a spiral handwriting tester.
The worn depth of the seat of the ball after writing, that is, the reduced length of the protruding length of the ball protruding from the holder, was measured. In the test of writing feeling and blurring of handwriting, a predetermined ink was filled in a ballpoint pen having a ball diameter of 0.5 mm, a spiral wire having a height of about 1.5 cm was drawn 10 times, and the judgment was made according to the following criteria. Writing feel: ○ Smooth and stable writing quality △ Rugged and hard writing quality × Rugged and hard writing quality, with line breaks and directionality Handwriting blurring: ○ Clear handwriting without blurring Very unclear handwriting

Example 1 A black aqueous ballpoint pen pigment ink was prepared with the following formulation. Pigment: Carbon black [“Carbon Black MA100” manufactured by Mitsubishi Kasei Co., Ltd.] 8.0% by weight Solvent: Glycerin 10.0 Solvent: Ethylene glycol 5.0 Ether: Glycerin monomethyl ether 5.0 Dispersant: Styrene acrylic acid resin Ammonium salt 3.0 Lubricant: Potassium oleate 0.3 pH adjuster: Triethanolamine 0.5 Preservative: Benzisothiazoline ["Proxel BDN" manufactured by Zeneca Corporation) 0.1 Anticorrosion agent: Benzotriazole 0 .1 Water: Purified water 68.0 Total 100.0

Example 2 A blue water-based ballpoint pen pigment ink was prepared with the following formulation. Pigment: Phthalocyanine Blue [“Chromofine Blue 4965” manufactured by Dainichiseika Co., Ltd.] 8.0% by weight Solvent: Glycerin 5.0 Solvent: Propylene glycol 7.0 Ether: Glycerin monomethyl ether 10.0 Dispersant: Styrene maleic acid Resin ammonium salt 3.0 Lubricant: Potassium linoleate 0.5 pH adjuster: Triethanolamine 0.7 Preservative: Benzisothiazoline ["Proxel BDN" manufactured by Zeneca Corp.) 0.1 Rust inhibitor: benzotriazole 0.1 Water: Purified water 65.6 Total 100.0

Comparative Example 1 A black aqueous pigment ink was obtained in the same manner as in Example 1 except that glycerin monomethyl ether was not used and ethylene glycol was 10%.

Comparative Example 2 Glycerin 1 without using glycerin monomethyl ether
Prepared as in Example 2 except 0%, propylene glycol 12%, potassium linoleate 0.7%, triethanolamine 1.0% and purified water 65.1%. Then, a blue water-based pigment ink was obtained.

Example 3 A black aqueous ballpoint pen pigment ink was prepared with the following formulation. Pigment: Carbon black [“Carbon Black MA100” manufactured by Mitsubishi Kasei Co., Ltd.] 8.0% by weight Solvent: Ethylene glycol 15.0 Ether: Diglycerin monomethyl ether 5.0 Dispersant: Styrene acrylic acid resin ammonium salt 3.0 Lubricant: Potassium linoleate 0.5 pH adjuster: Triethanolamine 0.7 Preservative: Benzisothiazoline ["Proxel BDN" manufactured by Zeneca Corp.) 0.1 Antirust agent: Benzotriazole 0.1 Water: Purification Water 67.6 Total 100.0

Example 4 A red aqueous ballpoint pen pigment ink was prepared with the following formulation. Pigment: Red pigment [Fuji Dye Co., Ltd. "RED K"] 8.0% by weight Solvent: Glycerin 10.0 Ether: Diglycerin monomethyl ether 10.0 Dispersant: Styrene maleic acid resin ammonium salt 3.0 Lubricant : Sodium ricinoleate 0.5 pH adjuster: Triethanolamine 0.7 Preservative: Benzisothiazoline ["Proxel BDN" manufactured by Zeneca Corp.) 0.1 Rust inhibitor: Benzotriazole 0.1 Water: Purified water 67 .6 total 100.0

Comparative Example 3 A black aqueous pigment ink was prepared in the same manner as in Example 3, except that diglycerin monomethyl ether was not used and ethylene glycol was 20%.

Comparative Example 4 Glycerin 20% and sodium ricinoleate 0.7% without using diglycerin monomethyl ether,
Triethanolamine was adjusted to 1.0%, and purified water was added to 67.
A red aqueous pigment ink was obtained in the same manner as in Example 4, except that the amount was 1%.

Table 1 shows the results of examining the ball sinking, the writing feeling, and the bleeding state of the handwriting in the writing test with the ballpoint pens using the inks obtained in Examples 1 to 4 and Comparative Examples 1 to 4.

[0028]

[Table 1] As described above, the aqueous pigment ink of the present invention has very little ball sinking, has a smooth writing feel, and is less likely to cause handwriting to bleed.

[0029]

INDUSTRIAL APPLICABILITY When used in a ball-point pen, the aqueous pigment ink composition for a ball-point pen of the present invention is suitable for use in a ball-point pen with less blurring of handwriting, good lubricity, and less wear of a ball seat due to rotation of the ball. It keeps the ink outflow and gives a smooth writing feeling. Further, since the ink is prevented from being dried by the pen tip, it is possible to prevent the ink from being easily scraped. Further, it can be suitably used as an ink composition for inkjet because it suppresses dry-up at the tip of the pen or the orifice, prevents clogging, and has less bleeding at the printed part.

Claims (8)

[Claims] 1. An aqueous pigment ink composition for a ballpoint pen, which comprises at least one ether selected from the group consisting of glycerin monomethyl ether and diglycerin monomethyl ether, a pigment, a dispersant, and water. 2. The glycerin monomethyl ether and the diglycerin monomethyl ether are added to a total composition of 0.
The pigment ink composition for water-based ballpoint pens according to claim 1, which comprises 5 to 40% by weight. 3. An aqueous pigment ink composition for a ball-point pen, which comprises a pigment, a dispersant, water, and glycerin monomethyl ether. 4. Glycerin monomethyl ether is 0.5 to 40% by weight of the total composition, pigment is 2 to 30% by weight of the composition, dispersant is 0.1 to 10% by weight of the composition, and water is 40%. The pigment ink composition for water-based ballpoint pens according to claim 3, wherein the pigment ink composition is contained in an amount of ˜90% by weight. 5. The aqueous pigment ink composition for a ballpoint pen according to claim 4, wherein the dispersant is a water-soluble polymer. 6. An aqueous pigment ink composition for a ball-point pen, which contains a pigment, a dispersant, water, and diglycerin monomethyl ether. 7. Diglycerin monomethyl ether in an amount of 0.5 to 40% by weight of the total composition, a pigment in an amount of 2 to 30% by weight, a dispersant in an amount of 0.1 to 10% by weight of the composition, and water. The pigment ink composition for water-based ballpoint pens according to claim 3, which is contained in an amount of 40 to 90% by weight. 8. The aqueous pigment ink composition for a ballpoint pen according to claim 7, wherein the dispersant is a water-soluble polymer.