JP2001234096A - Water-based ink composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based ink composition capable of developing colors of plural hues in one drawn line when used in writing utensils, etc., and good in follow-up properties of the ink without causing settling of an aluminum powder pigment and ink discoloration even in long-term storage and capable of carrying out the continuous writing. SOLUTION: This water-based ink composition comprises a pigment converted into a chromatic state by subjecting an aluminum powder to coloring treatment and having 10-100 μm average particle diameter, a dye having a hue different from the hue assumed by the pigment, water and a viscosity modifier.

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, and more particularly to a water-based ink composition that can be suitably used as an ink for a writing instrument such as a water-based ballpoint pen.

[0002]

2. Description of the Related Art Conventionally, writing implement inks have been required to obtain a stable writing line exhibiting a single hue, and the coloring agents used in the writing implement inks may be used alone or by mixing several kinds of pigments and dyes. Tones, and have been provided in the required writing line hue. These inks have a wavelength of 1 μm (the wavelength of visible light), which is the limit size that can be judged by human eyes, by reducing pigment particles to improve stability or improving the solubility of the dye itself. Lower limit 0.
It was adjusted so as not to produce colorant particles having a color of more than 5 μm). On the other hand, as an example of a writing implement ink using a colorant having a particle size of 1 μm or more, an aqueous ink of a writing line color using aluminum powder and exhibiting a feeling of luminance such as a metallic tone or a pearl tone is known. (Japanese Unexamined Patent Publication (Kokai) No. 63-72771), since aluminum itself does not exhibit a chromatic color, it only gives a sense of brightness to a writing line, and only exhibits a single color drawing line color.
Further, a pearlescent aqueous ink containing a pearl pigment, which is obtained by coating mica with a metal oxide and utilizing its transmission refraction and reflection, is known (JP-A-5-117569).
Since this pigment utilizes transmission refraction, it has a drawback that chromatic coloring is weak. Further, an aqueous ink using a pigment obtained by subjecting a metal powder to a coloring treatment is also known (WO 9).
Japanese Patent Application Laid-Open No. 8/26014), since the colorant is a single color, it only presents a single color. A water-based ink using a pigment obtained by subjecting a metal powder to a coating treatment and an organic pigment is also known (WO98 / 40441). However, since pigments are used in combination, metal coloring is performed when the ink is dried. The organic pigment aggregates around the pigment and only presents a single color.

[0003]

SUMMARY OF THE INVENTION According to the present invention, when used in a writing instrument or the like, a plurality of hues can be formed in one drawing line, and even if the aluminum powder pigment is settled or discolored even during long-term storage. Good ink follow-up
An object of the present invention is to provide a composition for an aqueous ink that can be continuously written.

[0004]

Means for Solving the Problems As a result of diligent research, the present inventors have used a chromatic color aluminum powder pigment which has been subjected to a coloring treatment, and blended a viscosity modifier for preventing pigment sedimentation and separation with water. It has been found that the aqueous ink obtained by this method satisfies the above-mentioned problems, and has completed the present invention.

That is, the present invention provides the following (1) to (4)
Exists. (1) An aqueous solution containing a pigment having an average particle diameter of 10 μm to 100 μm obtained by subjecting an aluminum powder to a coloring treatment and coloring, a dye having a hue different from the hue exhibited by the pigment, water, and a viscosity modifier Ink composition. (2) The aqueous ink composition according to the above (1), wherein the content of the chromatic pigment obtained by subjecting the aluminum powder to a coloring treatment is 0.5 to 15% by weight. (3) The aqueous ink composition according to the above (1) or (2), wherein the content of the dye is 0.1 to 15% by weight. (4) The ink viscosity is 800 mPa · s or more and 5000
The aqueous ink composition according to any one of the above (1) to (3), which is less than mPa · s and is used for a ballpoint pen.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Pigments obtained by subjecting aluminum powder used in the present invention to coloring and coloring (hereinafter referred to as "colored aluminum powder pigments") include, for example, a chemical adsorption method and a vacuum evaporation method. Is a pigment obtained by adsorbing and coating a color pigment on the surface of aluminum powder by applying the above method. By blending this into the ink, it provides a clearer and more glossy color than conventional metal powder pigments (aluminum, iron, etc.) Excellent multicolor coloring can be provided.

The colored aluminum powder pigment can be produced, for example, by a wet method, a dry method, or the like shown below.
First, in the wet method, for example, as disclosed in JP-A-2-142865, at least one carboxylic acid obtained by thermally polymerizing one or more carboxylic acids having a double bond is used.
A carboxylic acid polymer having two double bonds and two carboxyl groups and an aluminum powder pigment are stirred in an organic solvent, and a cake obtained by filtering the mixture and a colorant component are mixed or stirred in the presence of the organic solvent. , A method for producing by removing excess organic solvent, or a thermopolymerized carboxylic acid and a colorant component are stirred in an organic solvent, and the cake and the colorant component which are filtered are stirred and mixed in the presence of the organic solvent, Further, a method of dispersing and stirring this in an organic solvent, adding a monomer having three or more radically polymerizable double bonds and a polymerization initiator, polymerizing the mixture, removing excess organic solvent therefrom, and producing the mixture may be mentioned. . As the colorant component at this time, any organic pigment or inorganic pigment can be used as long as it can be dissolved in the organic solvent to be used. It is necessary that the coloring agent component be adsorbed. Specific examples of such colorants include, in organic pigments, azo chelate pigments, insoluble azo pigments, phthalocyanine pigments, sulene pigments, indigo pigments, perinone pigments, perylene pigments, phthalone pigments, dioxazine pigments, Examples thereof include quinacridone pigments, isoindolinone pigments, and metal complex pigments. Examples of the inorganic pigment include graphite, iron oxide, cobalt blue, carbon black, and titanium oxide.

In the dry method, the pigment can be manufactured by washing the surface of an aluminum powder pigment with an acid or an organic solvent, vaporizing a chromatic metal compound by a vacuum deposition method, a sputtering method, or the like, and coating and coating the compound. Specific examples of such metal compounds include chromatic metal compounds such as gold, silver, copper, nickel, hastelloy, iron oxide, cobalt oxide, and titanium oxide.

In the present invention, as the colored aluminum powder pigment, a pigment obtained by adsorbing a colored pigment on aluminum powder and further covering the surface with a synthetic resin is used.
It is even more desirable because it has a strong resistance to acids and other corrosive chemicals.

The average particle size of the colored aluminum powder pigment is
It is preferably about 10 to 100 μm. Average particle size is 10μ
If it is less than m, the hue of the pigment particles may not be recognized in the writing line. If the average particle size exceeds 100 μm, problems such as sedimentation and separation of the particles themselves, clogging at the pen tip, and deterioration of writing resistance may occur.

As a colored aluminum powder pigment, for example, a vacuum evaporation type ELSI Silver # 200
(74 μm); Gold # 200 (74 μm), R
ed # 200 (74 μm), Blue # 200 (74 μm)
m), Green # 200 (74 μm), Violet
# 200 (74 µm) or more, manufactured by Oike Kogyo Co., Ltd., or a chemical adsorption type Friend Color F350RG (30 µm)
m), F350BG (30 μm), F350RE (30
μm), F350OR (30 μm), F350GR (3
0 μm), F350BL (30 μm) or more, manufactured by Showa Aluminum Powder Co., Ltd., Astroflake # 5LG (100
μm), # 5DG (100 μm), # 5XG (100 μm)
m), # 5NG (100 μm) {or more, manufactured by Fukuda Metal Foil & Powder Co., Ltd.}, colored Al paste WH2600 (50 μm)
m), RE2600 (50 μm), GD2600 (50
μm), GR2600 (50 μm), BL2600 (5
0 μm) {or more, commercially available products such as Toyo Aluminum Co., Ltd.} can be advantageously used (the above parentheses indicate the average particle diameter).

The amount of the colored aluminum powder pigment is 0.5 to 15% by weight based on the total amount of the ink (hereinafter simply referred to as "%").
) Is preferable. If the amount used is less than 0.5%, the coloring properties of the writing lines may not be sufficient. If the amount used exceeds 15%, the solid content increases, the viscosity of the ink increases, and the fluidity decreases. There is a tendency that poor writing tends to occur, such as a decrease in ink follow-up properties.

As the dye in the present invention, any dye can be used without limitation as long as it is water-soluble and has a hue different from that of the colored aluminum powder pigment. Such a dye exhibits its own coloration in the area adsorbed and penetrated into the object to be written in the writing line, and hardly develops a color on the colored aluminum powder pigment, so that both the dye and the colored aluminum powder pigment are written on the writing line. Color development becomes possible. The dyes may be used alone or in combination of two or more as long as they have different hues from the colored aluminum powder pigment.

Specific examples of preferably usable dyes include CI Direct Yellow (Direct Y) as a direct dye.
ellow) 4, CI Direct Yellow 26, CI Direct Yellow 44, CI Direct Yellow 50, CI
Direct Red 1, CI Direct Red 4, CI Direct Red 23, CI Direct Red 31, CI Direct Red 37, CI Direct Red 39, CI Direct Red 75, CI Direct Red 80, CI Direct Red 81, CI Direct Red 83, CI Direct Red 225, CI
Direct Red 226, CI Direct Red 227, C.
I. Direct Violet 9, C.
I. Direct Blue 1, CI Direct Blue 2, CI Direct Blue 15, CI Direct Blue 71, CI Direct Blue 86, CI Direct Blue 106, CI Direct Blue 119, CI
Direct Green 30, Direct Black 154, and Direct Black 187.

Examples of basic dyes include CI Basic Yellow 1 and CI Basic Yellow.
2, CI Basic Yellow 21, CI Basic Yellow 25, CI Basic Orange
2, CI Basic Orange 14, CI Basic Orange 32, CI Basic Red 1, C.
I. Basic Red 2, CI Basic Red 9, C.
I. Basic Red 14, CI Basic Violet 3, CI Basic Blue (Basic)
Blue) 1, CI Basic Blue 9, CI Basic Brown 12, and the like.

Examples of the acid dyes include CI Acid Yellow 1, CI Acid Yellow 7, CI Acid Yellow 17, CI Acid Yellow 19, CI Acid Yellow 23, CI Acid Yellow 25, CI Acid Yellow 29, and CI Acid Yellow. 38, CI Acid Yellow 42, CI Acid Yellow 49, CI Acid Yellow 61, CI Acid Yellow 72, CI Acid Orange (AcidOrange) 7, CI Acid Red (Acid Red) 1, CI Acid Red 8, CI Acid Red 9, CI Acid Red 13, CI Acid Red 14, CI Acid Red 18, CI Acid Red 2
6, CI Acid Red 27, CI Acid Red 35,
CI Acid Red 37, CI Acid Red 51, CI
Acid Red 52, CI Acid Red 57, CI Acid Red 82, CI Acid Red 87, CI Acid Red 92, CI Acid Red 94, CI Acid Red 115, CI Acid Red 129, CI Acid Red 131, CI Acid Violet (Acid Violet) )
7, CI Acid Violet 17, CI Acid Violet 18, CI Acid Blue 1, CI
Acid Blue 7, CI Acid Blue 9, CI Acid Blue 22, CI Acid Blue 23, CI Acid Blue 25, CI Acid Blue 40, CI Acid Blue 41, CI Acid Blue 43, CI Acid Blue
62, CI Acid Blue 74, CI Acid Blue 7
8, CI Acid Blue 90, CI Acid Green (Ac
id Green) 3, CI Acid Green 7, CI Acid Green 9, CI Acid Green 16, CI Acid Brown 39, and the like.

The amount of the above dye is based on the total composition.
It is preferably about 0.1 to 15%, more preferably 1 to 5%. If the amount of the dye is less than 0.1%, the desired effect may not be sufficiently obtained due to the weak coloring property of the dye color of the writing line, and when stored for more than 15%, the pigment may aggregate. In addition, the dye itself may be deposited and clog the pen tip, causing poor writing.

The viscosity modifier in the present invention is used for suppressing the sedimentation of the colored aluminum powder pigment and for imparting appropriate fluidity as an ink for writing implements. The viscosity modifier is preferably selected from those having such properties that the effect is not reduced even when used together with the colored aluminum powder pigment or dye in the aqueous ink composition. Specific examples of the viscosity modifier include, in the case of natural polysaccharides, guar gum, locust bingham, galactomannan, pectin and its derivatives, syllium pseudogum, tamarind dough gum and the like of seed polysaccharides;
Microbial xanthan gum, leosan gum, ramzan gum, welan gum, julan gum and the like; seaweed polysaccharide carrageenan, alginic acid and derivatives thereof; resin polysaccharide tarragant gum, cellulose and derivatives thereof, and the like. Examples thereof include polyacrylic acid and its cross-linked copolymer, polyvinyl alcohol, polyvinyl pyrrolidone and its derivatives, and polyvinyl methyl ether and its derivatives. One or more viscosity modifiers can be selected and used in accordance with the amount and type of the colorant in the ink component. Among the viscosity modifiers, microbial gums have a strong viscosity-imparting effect and stability of physical properties in long-term storage, but tend to have strong propagation of various bacteria and cohesion of fine powder pigments. In addition, polyacrylic acid and its cross-linked copolymer are stable against the aggregation of pigments and the propagation of various bacteria, but the viscosity-imparting properties tend to be inferior to natural polysaccharides. It is preferable to select according to the characteristics.

The amount of the viscosity modifier to be used is 0.01 to
Although it is preferable to be in the range of about 2.0%, the preferable addition amount varies depending on the type of the viscosity modifier. For example, about 0.01 to 1.0% is preferable for a natural polysaccharide, and for a synthetic polymer, About 0.1-2.0% is preferable. If the addition amount of the viscosity modifier is too small, the sedimentation of the colorant is likely to occur, and if the addition amount exceeds 2.0%, the fluidity of the ink decreases or a hard cake due to aggregation of the pigment occurs, Writing defects due to poor ink followability tend to occur. In general, the fluidity of an ink can be determined by the viscosity of the ink. For example, from the numerical value measured with an E-type viscometer, which is a general rotational viscometer, the viscosity value at 1 rpm is used to suppress the sedimentation of the colorant. Is 800 mPa
s or more. In order to impart this viscosity, it is necessary to optimize the amount of the viscosity modifier added. When the viscosity value is 5000 mPa · s or more,
As the fluidity of the ink decreases, the follow-up of the ink and the supply to the writing paper from the pen tip of the ballpoint pen deteriorates.
It is required to adjust the addition amount of the viscosity modifier within an appropriate range. Furthermore, the determination of hard cake formation can be determined by placing the ink composition in a test tube and leaving it to stand.If sedimentation is observed at the bottom of the test tube and sediment is not released even when the test tube is impacted, As a result, a hard cake is formed, the supply of ink in the ink supply mechanism of the writing implement is suppressed, and writing may be poor. Therefore, it is necessary to optimize the addition amount of the viscosity modifier.

The amount of water in the ink composition of the present invention is not particularly limited.
The degree is preferred. If the amount of water is less than 20%, the amount of the non-volatile component and the colorant component becomes relatively large, so that the writing line becomes difficult to dry and the dye tends to precipitate. Conversely, if the amount of water exceeds 90%, the volatile components increase, and the pen tip tends to dry, resulting in poor writing.

The ink composition of the present invention may further comprise, if necessary, for example, a water-soluble medium, a surfactant, a preservative,
An adjusting agent, a rust preventive, a dispersant, a resin emulsion, a fixing agent and the like can be added.

The water-soluble medium prevents drying of the pen tip of the writing instrument ink, prevents freezing of the ink at a low temperature, a dissolution aid that enhances the dissolution of the ink component, and smoothly rotates the ball in the metal tip when used in a ballpoint pen. It is used for the purpose of lubrication effect etc. Specific examples of the water-soluble medium include ethylene glycol, diethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, thiodiglycol, glycerin, diglycerin,
Water-soluble liquid media having a moisturizing property, such as -pyrrolidone, n-methyl-2-pyrrolidone, butylcarbitol dimethylformamide, dimethylimidazolidinone, and the like, and one or a plurality thereof may be selected and used. Can be.

The surfactant is used for lubricating and wetting the ink itself.
It is used for the purpose of improving the effects of permeation, moisturizing, and the like. Specific examples thereof include polyoxyethylene and polyoxypropylene such as polyoxyethylene lauryl ether, derivatives of polyoxyethylene polyoxypropylene, and tetraglyceryl. Derivatives of glycerin or diglycerin or polyglycerin such as distearate, sorbitan derivatives such as sorbitan monooleate,
Examples thereof include a surfactant having a fluorinated alkyl group such as a perfluoroalkyl phosphate, and a polyether-modified silicone such as a polyethylene glycol adduct of dimethylpolysiloxane. One or more surfactants can be selected and used.

The pH adjuster is used for adjusting the pH value of the ink to a predetermined range or for stably maintaining the pH value. Specific examples thereof include ammonia, urea, monoethanolamine, diethanolamine, and the like. Examples thereof include triethanolamine, aminomethylpropanol and the like, alkali metal salts of carbonic acid and phosphoric acid such as sodium tripolyphosphate and sodium carbonate, and hydroxides of alkali metals such as sodium hydroxide. A species can be selected and used.

The preservative is used for the purpose of suppressing the deterioration of the ink by microorganisms such as molds and bacteria, and specific examples thereof include phenol, sodium omazine, sodium pentachlorophenol, 2-
Benzoisothiazoline-3-one, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, benzoic acid such as sodium benzoate, alkali metal salts such as sorbitanic acid and dehydroacetic acid, benzimidazole compounds, etc. And one or more of these can be selected and used.

The rust preventive is used for the purpose of suppressing the occurrence of corrosion due to an oxidation reaction and the like when the ink comes into contact with a metal member, thereby preventing the ink and the metal member from changing. Examples include benzotriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, tolyltriazole and the like, and one or more of these can be selected and used.

Examples of the dispersing agent include anionic surfactants such as alkylated sulfonate and alkylallyl sulfonate of higher fatty acid amide, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, acrylic acid copolymer, and the like. Water-soluble polymers such as acrylic methacrylic acid resin, styrene acrylic resin, maleic acid resin, and styrene maleic acid resin are mentioned.
Species or plural kinds can be selected and used.

The fixing agent is used for fixing the coloring agent on the writing line, and a water-soluble or water-dispersible film-forming substance can be selected and used. Specific examples of the fixing agent include a water-soluble acrylic polymer-based John Krill series (J-61J, J-62, J-354, etc .; manufactured by Johnson Polymer), a polyvinyl alcohol-based Poval series (manufactured by Chuo Gosei Co., Ltd.), Microbial polysaccharide-based pullulan (manufactured by Hayashibara Biochemical Laboratory), methylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like can be mentioned.

The resin emulsion is used to conceal the surface of the paper to be written, to improve the fluidity, to use a fixing aid, an anti-settling aid,
It is compounded for the purpose of abrasion suppression aids and the like, and specific examples thereof include Acronal YJ-110 manufactured by Mitsubishi Chemical Corporation.
0D, YJ-1800D, YJ-2773D, etc., such as Pontcoat SFC-241 and Paratecoll A-704, manufactured by Dainippon Ink, and Movinyl 742, manufactured by Hoechst Gosei Co., Ltd.
N, 749J, 081, 890, etc., Polysol C-10, AT-2000, AP-6730 manufactured by Showa Polymer Co., Ltd.
AE-116, AE-121, manufactured by Japan Synthetic Rubber Co., Ltd.
Nippol SX130 manufactured by Zeon Corporation such as T-371
2, LX303, G151, etc., and one or more of them can be selected and used as needed.

In order to produce the water-soluble ink composition of the present invention, various conventionally known methods can be employed. For example, after blending each of the above components, mixing and stirring with a stirrer such as a dissolver, or mixing and pulverizing with a ball mill or a three-roll etc., coarse particles of pigment particles or aluminum powder particles are optionally centrifuged or filtered. The water-soluble ink composition can be easily obtained by removing undissolved matter, mixed solid matter, and the like.

The aqueous ink composition of the present invention can be preferably used, for example, as a writing implement such as an aqueous ballpoint pen, a felt-tip pen, a marker, and the like, and an ink for a stamp.

[0032]

As will be apparent from the examples described below, by combining a colored aluminum powder pigment with a dye exhibiting a hue different from the hue exhibited by this pigment, a plurality of hues can be formed in one drawing line. Can be. On the other hand, even when a colored aluminum pigment is combined with a pigment exhibiting a different hue, only a single hue can be obtained. The reason is presumed as follows. Dyes are a mechanism in which a functional group in a molecule absorbs light to form a color, and exists at the molecular level even in a written line, so that a wavelength of 400 nm in the visible light region is used.
When the light of up to 900 nm reaches the colored aluminum powder pigment without any hindrance, the hue and glitter of the colored aluminum powder pigment can be improved. On the other hand, pigments are a mechanism in which particles themselves absorb light and develop color,
When the pigment particles dry agglomerate in the writing line and form a lump of 400 nm or more, the amount and wavelength of visible light reaching the colored aluminum powder pigment are limited, inhibiting the color development of the colored aluminum pigment and exhibiting multiple colors. It is thought that it becomes difficult.

[0033]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the present invention is not limited thereto. Example 1 <Component> Compounding amount (parts by weight) Gold pigment: (* 1) 10.0 Blue dye: (dye concentration: 8.6%) (* 2) 5.0 Pigment dispersant: styrene-acrylic copolymer (Solid content 33%) (* 3) 5.0 Water-soluble medium: propylene glycol 20.0 Viscosity modifier: Xanthan gum 0.5 Lubricant: Potassium oleate 0.5 Purified water 59.0 * 1; Friend color F503BG (manufactured by Showa Aluminum Powder Co., Ltd.) * 2; water Blue # 300 (manufactured by Daiwa Kasei) * 3; Joncryl J354 (manufactured by Johnson Polymer) The above composition was stirred and then filtered to obtain an aqueous ballpoint pen ink. Was.

Example 2 <Component> Compounding amount (parts by weight) Gold pigment: (* 1) 12.0 Black dye: (Dye concentration: 13%) (* 2) 5.0 Pigment dispersant: styrene-acrylic Polymer (33% solid content) (* 3) 5.0 Water-soluble medium: glycerin 20.0 Viscosity modifier: xanthan gum 0.5 Lubricant: potassium oleate 0.5 Purified water 57.0 * 1; Friend color F503BG (manufactured by Showa Aluminum Powder Co., Ltd.) * 2; water Black 256L (manufactured by Daiwa Kasei Co., Ltd.) * 3: Joncryl J354 (manufactured by Johnson Polymer Co.) The above composition was stirred and filtered to obtain an aqueous ballpoint pen ink.

Example 3 <Component> Compounding amount (parts by weight) Blue pigment: (* 1) 10.0 Red dye: Red No. 102 1.0 Pigment dispersant: Styrene-acrylic copolymer (solid content: 33%) ) (* 2) 5.0 Water-soluble medium: propylene glycol 20.0 Viscosity modifier: Polyacrylic acid resin (* 3) 1.0 Lubricant: Potassium oleate 0.5 Purified water 62.5 * 1; Friend Color F503BLP (manufactured by Showa Aluminum Powder Co., Ltd.) * 2; Joncryl J354 (manufactured by Johnson Polymer) * 3; Hibiswako 104 (manufactured by Wako Pure Chemical Industries, Ltd.) Was.

Example 4 <Component> Amount (parts by weight) Blue pigment: (* 1) 10.0 Yellow dye: Yellow No. 4 1.0 Pigment dispersant: Styrene-acryl copolymer (solid content: 33%) ) (* 2) 5.0 Aqueous medium: Glycerin 20.0 Viscosity modifier: Guar gum 0.5 Lubricant: Potassium oleate 0.5 Purified water: 63.0 An ink for a ballpoint pen was obtained. * 1: Friend Color F503BLP (manufactured by Showa Aluminum Powder) * 2: John Krill J354 (manufactured by Johnson Polymer)

Example 5 <Component> Compounding amount (parts by weight) Red pigment: (* 1) 10.0 Blue dye: (dye concentration: 8.6%) (* 2) 5.0 Pigment dispersant: styrene- Acrylic copolymer (solid content 33%) (* 3) 5.0 Water-soluble medium: propylene glycol 20.0 Viscosity modifier: Locust bingham 0.5 Lubricant: Potassium oleate 0.5 Purified water: 59.0 * 1: Friend Color F503REP base (manufactured by Showa Aluminum Powder Co., Ltd.) * 2: water Blue # 300 (manufactured by Daiwa Kasei Co., Ltd.) * 3: Joncryl J354 (manufactured by Johnson Polymer Co.) An aqueous ballpoint pen ink was obtained.

Comparative Example 1 <Component> Compounding amount (parts by weight) Gold pigment: (* 1) 10.0 Blue pigment: (* 2) 5.0 Pigment dispersant: styrene-acrylic copolymer (solid content: 33) %) (* 3) 5.0 Water-soluble medium: propylene glycol 20.0 Viscosity modifier: Xanthan gum 0.5 Lubricant: Potassium oleate 0.5 Purified water: 59.0 * 1; Friend color F503BG (Showa Aluminum * 2; Lactimine color BlueFL2B conc (manufactured by Dainichi Seika) * 3; Joncryl J354 (manufactured by Johnson Polymer) The above-mentioned composition was stirred and filtered to obtain an aqueous ballpoint pen ink.

Comparative Example 2 <Component> Compounding amount (parts by weight) Aluminum pigment: (* 1) 12.0 Black dye: (Dye concentration: 13%) (* 2) 5.0 Pigment dispersant: styrene-acrylic Polymer (solid content 33%) (* 3) 5.0 Aqueous medium: glycerin 20.0 Viscosity modifier: xanthan gum 0.5 Lubricant: potassium oleate 0.5 Purified water: 57.0 * 1; aluminum Paste WB0230 (manufactured by Toyo Aluminum Co., Ltd.) * 2; water. Black256L (manufactured by Daiwa Kasei Co., Ltd.) * 3; Joncryl J354 (manufactured by Johnson Polymer Co.) The above composition was stirred and filtered to obtain an aqueous ballpoint pen ink.

Comparative Example 3 <Component> Compounding amount (parts by weight) Blue pigment: (* 1) 25.0 Red dye: Red No. 102 1.0 Pigment dispersant: Styrene-acryl copolymer (solid content: 33%) ) (* 2) 5.0 Water-soluble medium: propylene glycol 20.0 Viscosity modifier: polyacrylic acid resin (* 3) 1.0 Lubricant: Potassium oleate 0.5 Purified water: 47.5 or more The mixture was stirred and filtered to obtain an aqueous ballpoint pen ink. * 1; Friend Color F503 BLP (manufactured by Showa Aluminum Powder Co., Ltd.) * 2: Joncryl J354 (manufactured by Johnson Polymer) * 3;

Comparative Example 4 <Component> Compounding amount (parts by weight) Blue pigment: (* 1) 10.0 Yellow dye: Red No. 4 16.0 Pigment dispersant: Styrene-acrylic copolymer (solid content 33%) ) (* 2) 5.0 Water-soluble medium: glycerin 20.0 Viscosity modifier: guacam 0.5 Lubricant: potassium oleate 0.5 Purified water: 48.0 * 1; Friend Color F503 BLP (Showa aluminum powder) * 2; John Krill J354 (manufactured by Johnson Polymer Co.) The above composition was stirred and filtered to obtain an aqueous ballpoint pen ink.

Comparative Example 5 <Component> Compounding amount (parts by weight) Red pigment: (* 1) 10.0 Blue dye: (dye concentration: 8.6%) (* 2) 5.0 Pigment dispersant: styrene- Acrylic copolymer (solid content 33%) (* 3) 5.0 Water-soluble medium: propylene glycol 20.0 Viscosity modifier: Locust bingham 2.0 Lubricant: Potassium oleate 0.5 Purified water: 57.5 * 1; Friend Color F503REP base (manufactured by Showa Aluminum Powder Co., Ltd.) * 2; water. Blue # 300 (manufactured by Daiwa Kasei Co., Ltd.) * 3: Joncryl J354 (manufactured by Johnson Polymer Co., Ltd.) An aqueous ballpoint pen ink was obtained.

Comparative Example 6 <Component> Compounding amount (parts by weight) Gold pigment: (* 1) 10.0 Blue dye: (dye concentration: 8.6%) (* 2) 5.0 Pigment dispersant: styrene Acrylic copolymer (solid content 33%) (* 3) 5.0 Water-soluble medium: propylene glycol 20.0 Viscosity modifier: polyacrylic acid resin (* 4) 0.2 Lubricant: potassium oleate 0.5 Purified water: 59.3 * 1; Friend Color F503BG (manufactured by Showa Aluminum Powder Co., Ltd.) * 2; water. Blue # 300 (manufactured by Daiwa Kasei Co., Ltd.) * 3; John Krill J354 (manufactured by Johnson Polymer) * 4; Hibiswako 104 (manufactured by Wako Pure Chemical Industries, Ltd.) The above formulation was stirred and filtered to obtain an aqueous ballpoint pen ink.

Test Examples The inks obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were tested by the following test methods. The results are shown in Tables 1 and 2. <Test method> (1) Average particle diameter: NI using photon correlation method within one week after ink preparation
The average particle diameter is measured using COMP 370 (manufactured by Nozaki Sangyo). After the ink is prepared, it is left at room temperature for 6 months, and then the particle size is measured in the same manner as in the initial stage. (2) Viscosity value: The viscosity value at 1 rpm is measured using an EMD type viscometer (manufactured by Toki Sangyo) within one week after ink preparation. After the ink is prepared, it is left at room temperature for 6 months, and the viscosity is measured in the same manner as in the initial stage. (3) Ink color development: 3.5 ink inside diameter without relay core
The ink was filled into a refill composed of a stainless steel nib having a ball diameter of 0.7 mm and a polypropylene ink storage tube having a length of 100 mm and a length of 100 m, and a ballpoint pen body A for evaluation was produced. Using the ballpoint pen body A for evaluation, writing was performed on Xerox M paper (absorbent paper; manufactured by Xerox Corporation), and the coloring of the written lines was visually confirmed. The evaluation criteria were a three-step evaluation as described below. ：: Two types of hues can be confirmed on the drawing line. Δ: Two types of hues can be confirmed by changing the visual angle of the drawing line. X: Only a single color hue is recognized. (5) Ink followability: Using the above-mentioned trial ballpoint pen body A, handwriting spiral writing was performed by hand, and the resulting drawing lines were visually observed for the ink breakability and the presence or absence of splitting. ◎: Not at all ○: Slightly present △: Slightly present ×: Very many

[0045]

[Table 1]

From Table 1, it is apparent that the ink of the present invention is stable with little change in the aggregation or thickening of the colored metal powder pigment particles over time.

[0047]

[Table 2]

From Table 2, it can be determined that the ink of the present invention is an ink having a plurality of coloring properties and good ink followability of the ink. In particular, in the present invention, a colored aluminum powder pigment,
By combining and combining a dye exhibiting a different hue with the hue exhibited by this pigment, it was confirmed that a plurality of hues were developed in one drawing line, but it was confirmed that a colored aluminum pigment and a pigment exhibiting a different hue were produced. In the combination (Comparative Example 1), only a single color hue was recognized, and the color developability was poor.

[0049]

As described above, the aqueous ink composition of the present invention uses a pigment obtained by subjecting an aluminum powder to a coloring treatment and a dye having a hue different from the hue of the pigment as a coloring agent, so that a single line is obtained. And a plurality of hues, and has excellent long-term storage stability, good ink followability, and is highly useful as an ink for writing implements.

Claims (4)

[Claims] 1. A pigment having an average particle diameter of 10 μm to 100 μm obtained by subjecting an aluminum powder to a coloring treatment and coloring, a dye having a hue different from the hue exhibited by the pigment, water, and a viscosity modifier. Aqueous ink composition. 2. A water-based ink composition according to claim 1, wherein the content of the chromatic pigment obtained by subjecting the aluminum powder to a coloring treatment is 0.5 to 15% by weight. 3. The aqueous ink composition according to claim 1, wherein the content of the dye is 0.1 to 15% by weight. 4. An ink having a viscosity of 800 mPa · s or more,
The aqueous ink composition according to any one of claims 1 to 3, which has a viscosity of less than 000 mPa · s and is used for a ballpoint pen.