JPH07242851A - Pigment ink composition for aqueous ball point pen - Google Patents

Abstract

PURPOSE:To obtain a pigment ink composition for aqueous ball point pen, containing galactomanan, a pigment, a dispersant, a lubricant and water, reduced in abrasion of the ball holder, remarkably reduced in blur of a written letter or a printed part and excellent in discharge properties, smoothness and feeling in writing. CONSTITUTION:This pigment ink composition for aqueous ball point pen contains (A) preferably 0.01 to 20wt.% galactomanan, (B) preferably 2 to 30wt.% pigment such as titanium oxide, (C) preferably 0.1 to 10wt.% dispersant such as a water-soluble polymer, e.g. a polyglycerol fatty acid ester, (D) preferably 0.01 to 5wt.% lubricant such as potassium linolate and (E) preferably 40 to 90wt.% water.

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 order to suppress ink drying at the pen tip (non-drying property), a water-soluble solvent such as glycol or glycerin is used in addition to water as a main component solvent, and a pigment is dispersed as a colorant. However, as it is, the lubricity is poor and the friction resistance between the ball and the ball seat increases when the ball rotates during writing, causing defects such as rattling of the ball and uneven ink outflow. , The writability is remarkably reduced. For the purpose of improving such defects, it has been attempted to add a lubricity improver such as unsaturated fatty acid or potassium oleate. However, if the lubricity improver is increased to improve the lubricity, there is a problem of practicality such that the handwriting is easily bleeded. On the other hand, if the lubricity improver is not sufficiently added, the lubricity cannot be obtained and The phenomenon of inability to write occurs due to wear of the seat.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art. It is difficult for the handwriting to bleed and has sufficient lubricity to allow smooth ball rotation for ball seating. The present invention intends to provide a pigment ink for water-based ballpoint pens, which has less abrasion and has a markedly improved writing performance, gives a comfortable writing feeling, and is also excellent in non-drying property.

[0004]

As a result of intensive studies to solve the above problems, the present inventor has found that the above object can be achieved by incorporating galactomannan into the pigment ink composition. The present invention has been completed based on this finding.

The aqueous ball-point pen pigment ink composition of the present invention is characterized by containing galactomannan, a pigment, a dispersant, a lubricity improver and water. Preferably, the content of each component of the total composition is 0.01 of galactomannan.
-20% by weight, 2-30% by weight of pigment, 0.1% of dispersant
It is an aqueous pigment ink composition for a ball-point pen containing 10 to 10% by weight, 0.01 to 5% by weight of a lubricity improver, and 40 to 90% by weight of water.

[0006] The galactomannan used in the ink composition of the present invention is a polysaccharide having galactose and mannose as constituent components, and the composition varies depending on the preparation method, but generally, the content ratio of galactose and mannose is from 1: 3 to 1. :
At around 4, the structure is a β-1,4-linked mannose residue chain with a side chain of one galactose residue with an α-1,6 bond at different frequencies. Expression

[Chemical 1] The galactomannan represented by can be shown. Galactomannan is effective as a dispersant either alone or in combination with other polymers or surfactants. The content of galactomannan is preferably 0.01 to 20% by weight of the total composition, more preferably 0.5 to 1% by weight. The effect varies depending on the molecular weight. A relatively high molecular weight one is effective even if the content is small, but a low molecular weight one is not effective unless the content is large.

There are no particular restrictions on the type of pigment used in the ink composition of the present invention, and it is possible to use any of the inorganic and organic pigments conventionally used in water-based pigment ink compositions. it can. 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 (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 selected in the range of 2 to 30% by weight, preferably 5 to 15% by weight based on the weight of the entire composition. Be done.

The dispersant in the composition of the present invention is for adsorbing on the surface of pigment particles to disperse the pigment in water, and examples thereof include nonion, anionic surfactant and water-soluble polymer. . It is preferably a water-soluble polymer. 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 amide, a polyoxyethylene alkyl phenyl formaldehyde condensate.

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.

Examples of water-soluble polymers include polyacrylic acid salts, 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. 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 dimethylethanolamine, as well as ammonia, morpholine and N-methylphorine. The content of the dispersant is 0.1 to 10% by weight in the composition.

Examples of the lubricity improver used in the ink composition of the present invention include potassium linoleate, sodium ricinoleate, potassium oleate, sodium oleate and the like. The preferred content is 0.
01 to 5% by weight, more preferably 0.5 to 3.0% by weight
Is.

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

The ink composition of the present invention may contain 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. The content thereof is usually 40% by weight or less, preferably 5 to 40% by weight, based on the entire composition.

In addition to the above, if necessary, preservatives such as phenol and sodium benzoate, rust preventives such as benzotriazole, dicyclohexylammonium nitrite and diisopropylammonium nitrite, and pH adjusting agents such as triethanolamine , Monoethanolamine, diethanolamine, ammonia, etc. may be contained.

The viscosity of the ink composition of the present invention is 15 mPa.
s or less is preferable. If this viscosity is exceeded, the ballpoint pen ink may not flow out sufficiently.

In the production of the ink composition of the present invention, each component is stirred and mixed in a stirrer for 3 to 5 hours, dispersed in a sand mill for 5 to 7 hours, and coarse particles are removed by a centrifuge. Get by. The order in which the components are mixed is not particularly limited, but the viscosity of the ink is increased by adding galactomannan, so that the viscosity of the ink should be 1
It is necessary to pay attention to the order of compounding in order to keep it at 5 mPa · s or less.

When the ink composition of the present invention is used in a ballpoint pen, it has less bleeding and good lubricity, but it is considered that this is due to the viscosity due to the content of galactomannan and the dispersant.

[0018]

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. Batting was laid vertically on the inks obtained in the respective Examples and Comparative Examples, the ink was sucked up by a capillary force, and the inks were filled into polypropylene ink storage tubes each having an inner diameter of 8 mm and made by Mitsubishi Pencil Co., Ltd. A test for writing characters on a PPC paper by hand was conducted by using a ballpoint pen equipped with this ink containing tube and a stainless steel tip having a ball diameter of 0.5 mm.
The following criteria were used to evaluate the writing feeling and the blurring state of handwriting in the writing test. Writing feel: ○ Smooth and stable writing quality △ Rugged and hard writing quality × Rugged and hard writing quality, with line breaks and directionality. Blurring of handwriting: ○ Clear handwriting without blurring △ Blurring and unclear writing × Extremely unclear writing with remarkable blurring

Example 1 A black aqueous ballpoint pen pigment ink having the following contents was prepared. Carbon black: ["MA100" manufactured by Mitsubishi Kasei Co., Ltd.] 8.0 wt% galactomannan: ["JAGUAR 8111" manufactured by Sansho Co., Ltd.] 0.1 Solvent: Glycerin 10.0 Solvent: Ethylene glycol 10.0 Dispersant: Styrene acrylic acid resin ammonium salt 3.0 Lubrication improver: Potassium oleate 0.3 pH adjuster: Triethanolamine 0.5 Preservative: ["Proxel BD" (manufactured by ICI)] 0.1 Rust prevention Agent: Benzotriazole 0.1 Water: Purified water 67.9 Total 100.0

Example 2 A blue water-based ballpoint pen pigment ink was prepared with the following formulation. Phthalocyanine blue: ["Chromofine Blue 4965" manufactured by Dainichiseika Co., Ltd.] 8.0 wt% galactomannan: ["Sunfiber" manufactured by Taiyo Kagaku Co., Ltd.] 5.0 Solvent: Glycerin 5.0 Solvent: Propylene glycol 17.0 Dispersant: Styrene maleic acid resin ammonium salt 3.0 Lubrication improver: Potassium linoleate 0.5 pH adjuster: Triethanolamine 0.7 Preservative: ["Proxel BD" (manufactured by ICI)] 1 Anticorrosive: Benzotriazole 0.1 Water: Purified water 60.6 Total 100.0

Example 3 A black water-based ballpoint pen pigment ink was prepared with the following formulation. Carbon black: ["MA100" manufactured by Mitsubishi Kasei Co., Ltd.] 8.0 wt% galactomannan: [manufactured by "Sun Fiber" Taiyo Kagaku Co., Ltd.] 5.0 Solvent: Glycerin 10.0 Solvent: Ethylene glycol 10.0 Dispersant: Styrene acrylic acid resin ammonium salt 3.0 Lubrication improver: Potassium oleate 0.3 pH adjuster: Triethanolamine 0.5 Preservative: ["Proxel BD" (manufactured by ICI)] 0.1 Rust prevention Agent: Benzotriazole 0.1 Water: Purified water 63.0 Total 100.0

Example 4 A red aqueous ballpoint pen pigment ink was prepared with the following formulation. Red pigment: ["RED K" manufactured by Fuji Dye Co., Ltd.] 8.0 wt% galactomannan: ["JAGUAR 8111" manufactured by Sansho Co., Ltd.] 0.1 Solvent: Glycerin 10.0 Solvent: Diglycerin monomethyl ether 10.0 Dispersant: Styrene maleic acid resin ammonium salt 3.0 Lubrication improver: Sodium ricinoleate 0.5 pH adjuster: Triethanolamine 0.7 Preservative: ["Proxel BD" (manufactured by ICI)] 1 Anticorrosive: Benzotriazole 0.1 Water: Purified water 67.5 Total 100.0

Comparative Example 1 "JAGUAR 8111" from Example 1 [Sansei Co., Ltd.]
Manufactured) was prepared to obtain a black aqueous pigment ink.

Comparative Example 2 A blue water-based pigment ink was obtained by preparing a composition obtained by removing "Sunfiber" (Taiyo Kagaku KK) from Example 2.

Comparative Example 3 A black aqueous pigment ink was prepared by removing "Sunfiber" (Taiyo Kagaku Co., Ltd.) from Example 3 except that potassium oleate was reduced to 0.1%.

Comparative Example 4 From Example 4, "JAGUAR 8111" [Sansei Co., Ltd.]
Manufactured) to prepare a red aqueous pigment ink.

Table 1 shows the results of examining 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 water-based pigment ink of the present invention has a smooth writing feel and is less likely to cause handwriting bleeding.

[0029]

INDUSTRIAL APPLICABILITY The aqueous pigment ink composition for a ball-point pen of the present invention, when used in a ball-point pen, has less abrasion of a ball seat due to rotation of the ball, maintains proper ink outflow property, and has less bleeding of handwriting. Gives good lubricity and smooth writing feel. In addition, since the bleeding of the printed portion is small, it is extremely suitable as an ink composition for inkjet.

Claims (4)

[Claims] 1. An aqueous pigment ink composition for a ball-point pen, which contains galactomannan, a pigment, a dispersant, a lubricity improver, and water. 2. The aqueous pigment ink for a ballpoint pen according to claim 1, wherein the galactomannan is contained in an amount of 0.01 to 20% by weight based on the total composition. 3. The galactomannan is 0.01 to 20% by weight, the pigment is 2 to 30% by weight, the dispersant is 0.1 to 10% by weight, the lubricity improver is 0.01 to 5% by weight, and water is. 40
The composition is contained in an amount of about 90% by weight.
The pigment ink composition for water-based ballpoint pens as described above. 4. The aqueous pigment ink composition for a ballpoint pen according to claim 3, wherein the dispersant is a water-soluble polymer.