JP2019011397A - Water-based ink composition for writing instrument, and writing instrument using the same - Google Patents

Abstract

To provide an ink composition for writing instrument excellent in color development and fixability, and writing instrument using the same.SOLUTION: There are provided a water-based ink composition for writing instrument containing a pigment, a guar gum derivative, a hardly water soluble resin, and water, in which V/U is 0.0005≤V/U≤0.05, wherein total content of the pigment based on total amount of the ink composition is U, and total content of the guar gum derivative based on total amount of the ink composition is V and X/V is 5≤X/V≤75, wherein total content of the hardly water soluble resin based on total amount of the ink composition is X, and writing instrument using the same.SELECTED DRAWING: None

Description

  The present invention relates to a water-based ink composition for a writing instrument. More specifically, the present invention relates to a water-based ink composition for a writing instrument that is excellent in color development and fixing properties of handwriting ink when written on paper, cloth, and the like. The present invention also relates to a writing instrument using the composition.

  Conventionally, ink compositions for writing instruments that can be written on paper and cloth are known, and among them, water-based ink compositions using water as the main solvent have a low environmental impact and high safety, It has been actively studied. Such an ink composition uses a colorant or a fixing agent to fix the ink on the surface of paper or cloth, and attempts to obtain a clear handwriting. (Patent Document 1)

  Patent Document 1 describes an ink for a writing instrument using a pigment, water, and a resin emulsion having a specific film-forming temperature. The handwriting formed with this ink has high fixability, and the handwriting written on the cloth is made difficult to peel off from the cloth during washing.

  However, when the ink composition described in Patent Document 1 is used to write on the surface of a writing material having a large gap between fibers such as paper and cloth, the ink composition passes through the gap between the fibers. Since the penetrating into the cursive body and the colorant hardly stays on the surface of the cursive body, the handwriting sometimes becomes unclear.

JP 2005-290237 A

  In the present invention, even when writing on the surface of a writing body having a large gap between fibers such as paper and cloth, the coloring agent passes through the gap between the fibers and does not enter the inside of the writing body. An object of the present invention is to provide an ink composition for a writing instrument that can retain the agent on the fiber surface of the writing surface and has excellent color development and fixing properties of handwriting.

  The water-based ink composition for a writing instrument according to the present invention includes a pigment, a guar gum derivative, a sparingly water-soluble resin, and water. The total content of the pigment with respect to the total amount of the ink composition is U, and the total content of the guar gum derivative is V. V / U is in the range of 0.0005 ≦ V / U ≦ 0.05, and X / V is 5 ≦ X / V ≦ when the total content of the poorly water-soluble resin is X. It is characterized by being in the range of 75.

  The writing instrument according to the present invention is characterized by containing the composition.

  ADVANTAGE OF THE INVENTION According to this invention, even when writing on the surface of a to-be-written object with large gaps between fibers, such as paper and cloth, the ink composition for writing instruments which exhibits the outstanding coloring property of a handwriting and the high fixability of a handwriting is provided. Is done.

  Hereinafter, embodiments of the present invention will be described in detail. In the present specification, “part”, “%”, “ratio” and the like indicating the composition are based on mass unless otherwise specified, and the content is based on the mass of the water-based ink composition for writing instruments. % By mass of the constituents of

  The water-based ink composition for writing instruments according to the present invention (hereinafter sometimes referred to as “water-based ink composition”, “ink composition” or “composition”) includes a pigment, a guar gum derivative, and a poorly water-soluble composition. A water-soluble resin and water. Hereafter, each component which comprises the water-based ink composition by this invention is demonstrated.

(Pigment)
In the present invention, the pigment can be arbitrarily selected from conventionally known inorganic pigments, organic pigments, and glossy bright pigments, and can be preferably used. Specific examples of inorganic pigments include carbon black, titanium oxide, zinc oxide, iron black, yellow iron oxide, dials, metal oxides such as complex oxide pigments, and ultramarine blue, and organic pigments include azo. Pigments, indigo pigments, phthalocyanine pigments, quinacridone pigments, thioindigo pigments, selenium pigments, perinone pigments, perylene pigments, phthalone pigments, dioxane pigments, isoindolinone pigments, metal complex pigments, Examples include methine / azomethine pigments, diketopyrrolopyrrole pigments, and examples of glossy glitter pigments include aluminum pigments and glass flake pigments.
As the composition of the present invention, a pigment dispersion obtained by dispersing the pigment in a solvent can be used. Examples of the pigment dispersion used in the present invention include SP series (manufactured by Fuji Dye Co., Ltd.), SANDYESUPERCOLOR series (manufactured by Sanyo Dye Co., Ltd.), EMACOL series (manufactured by Sanyo Dye Co., Ltd.), and Lumicol series (Nippon Fluorescent Chemical Co., Ltd.). MCROPIGMO series (manufactured by Co., Ltd.), (made by Orient Chemical Co., Ltd.), WA series (manufactured by Dainichi Seika Kogyo Co., Ltd.), etc.
In the water-based ink composition of the present invention, it is preferable to use a metal oxide as the pigment, and it is particularly preferable to use titanium oxide. By using such a pigment, it is combined with other pigments for complementary color. With this, various colors can be realized.

  In the water-based ink composition of the present invention, the pigment is preferably surface-treated with a coating material. Examples of the coating material include inorganic oxides such as silica, alumina, zirconia, and zinc oxide, and molybdenum. Metal or phosphate is preferred. This is because the surface treatment of the pigment with the above coating material suppresses aggregation of the pigments in the ink, stabilizes the dispersion of the pigment, and suppresses the reaction between the pigment and water, thereby suppressing the generation of bubbles. Because you can. Furthermore, when a pigment containing metal is subjected to a shearing force from a mixer or the like during ink production, the pigment is prevented from being deformed or damaged, and metal ions are prevented from eluting, thereby improving the ink stability over time. Is possible. Considering the dispersion stability in the ink, the pigment coating material is more preferably an inorganic oxide containing silica or alumina.

  About the pigment, the coating amount of the pigment surface-treated with the coating material is 0.01% by mass to 20% by mass with respect to 100 parts by mass of the pigment mass after the surface treatment with the coating material. It is preferable that it is 0.1% by mass to 8.0% by mass. When the coating amount is within the above numerical range, it is possible to facilitate the dispersion of the water-based ink composition and the suppression of metal elution.

  In the present invention, when a pigment surface-treated with an inorganic oxide is used, the pigment surface-treated with an inorganic oxide in a water-based ink composition has a positive value or a negative value in consideration of dispersion stability in the ink. It is preferable to have a surface charge of the value of, especially when using a pigment treated with an inorganic oxide containing silica, it is preferred to have a negative value of surface charge and treated with an inorganic oxide containing alumina. When using a pigment, it preferably has a positive value. Such a pigment exhibits good dispersibility in the composition, but dispersibility and redispersibility can be further improved by combining with a pigment dispersant described later. When the surface-treated pigment has the above surface charge, the surface-treated pigment is preferably titanium oxide in consideration of dispersion stability in the ink.

  The average particle diameter of the pigment is preferably 0.01 μm to 30 μm, more preferably 0.05 μm to 15 μm, and still more preferably 0.1 μm to 5 μm. If the average particle diameter of the pigment is within the above numerical range, even when writing on a writing material having a large gap between fibers such as paper and cloth, the pigment does not easily enter the gap between the fibers, and the clear color developability. It is because it is easy to obtain. In addition, when a water-based ink composition containing a pigment having an average particle diameter within the above numerical range is used for a writing instrument such as a marker, ink discharge properties can be improved. The average particle size of the pigment is, for example, 50% volume cumulative particle size distribution measured by a laser diffraction method using a laser diffraction particle size distribution analyzer (trade name “Microtrac HRA9320-X100”, Nikkiso Co., Ltd.). It can be measured by the particle size (D50) at the time. In the present specification, the “average particle diameter” of the pigment refers to an average particle diameter based on volume unless otherwise specified.

  The content of the pigment in the water-based ink composition is preferably 1% by mass to 40% by mass, and more preferably 2% by mass to 30% by mass with respect to the total amount of the ink composition. If the content of the pigment is within the above numerical range, it is possible to prevent a decrease in ink discharge properties and maintain the sharpness and concealment of the water-based ink composition and the handwriting formed using the same. Can do.

(Pigment dispersant)
The aqueous ink composition of the present invention preferably contains a pigment dispersant. By combining the pigment dispersant and the pigment, it is possible to suppress aggregation of the pigments and improve the stability of the ink. The pigment dispersant used in the present invention is not particularly limited as long as it has an effect of enhancing the dispersibility of the pigment. However, when using a pigment surface-treated with an inorganic oxide, the dispersion stability of the pigment is taken into consideration. It is preferable to use a pigment dispersant having an anionic adsorption group or a cationic adsorption group.

When a pigment surface-treated with an inorganic oxide containing silica is used in the composition of the present invention, the pigment dispersant preferably has a cationic adsorption group. Considering the stability of the ink composition, the acid basicity of the ink composition is preferably near neutral, but the pigment in the ink composition in this liquid property has a negative surface charge, Cationic adsorptive groups are easily adsorbed to the pigment by electric attraction, and can be easily dispersed.
Specific examples of the pigment dispersant having a cationic adsorptive group include DISPERBYK-184 and DISPERBYK-2055 (manufactured by Big Chemie Co., Ltd.), which are preferably used. The pigment dispersant having a cationic adsorption group used in the present invention is not limited to these. One or more pigment dispersants can be used.
In consideration of the dispersibility of the pigment, DISPERBYK-184 is particularly preferable as the pigment dispersant having a cationic adsorption group.

Moreover, when using the pigment surface-treated with the inorganic oxide containing an alumina for a composition, it is preferable that a pigment dispersant has an anionic adsorption group. In the acid basicity, since the pigment has a positive surface charge, the anionic adsorptive group is easily adsorbed to the pigment by electric attraction, and can be easily dispersed.
Specific examples of the pigment dispersant having an anionic adsorptive group include DISPERBYK-190, DISPERBYK-194N, DISPERBYK-2010 (manufactured by Big Chemie Co., Ltd.) and are preferably used. The pigment dispersant having an anionic adsorptive group used in the present invention is not limited to these. One or two or more pigment dispersants can be used. In consideration of the dispersibility of the pigment, DISPERBYK-190 is particularly preferable as the pigment dispersant having an anionic adsorption group.

  The content of the pigment dispersant in the present invention is preferably 0.01% by mass to 5% by mass, and 0.05% by mass to 3% by mass based on the total amount of the ink composition in terms of solid content of the active ingredient. % Is more preferable. Further, when the total content of the pigment surface-treated with the inorganic oxide is S and the total content of the pigment dispersant with respect to the total amount of the ink composition is T, T / S is 0.005 ≦ T / S ≦ 0.5 is preferable, and 0.01 ≦ T / S ≦ 0.2 is more preferable. When the content of the pigment dispersant and the ratio of the content of the pigment dispersant and the content of the pigment surface-treated with the inorganic oxide are within the above numerical range, the dispersibility of the pigment is improved, and the ink composition It can suppress that the viscosity of becomes too high.

(Guar gum derivative)
It is important that the aqueous ink composition according to the present invention comprises a guar gum derivative.
The guar gum derivative is adsorbed to pigment particles and polyolefin particles described later in the ink composition to form a bulky aggregate of the pigment, thereby writing on a writing material having a large gap between fibers such as paper and cloth. At this time, the pigment is prevented from penetrating the inside of the writing body through the gap between the fibers, and the pigment is easily attached to the fiber on the surface of the writing body, thereby improving the coloring property of the handwriting. . In addition, the guar gum derivative imparts shear thinning to the ink composition, suppresses handwriting bleeding during writing, and suppresses the pigment in the ink composition from forming a hard cake. It is possible to suppress ink leakage from the ink discharge portion of the writing instrument when a writing instrument using an object, particularly a ballpoint pen, is left standing.
Guar gum is a polysaccharide in which galactose (α-D-galactopyranose) is α- (1-6) -linked to a linear main chain (β- (1-4) -D-mannopyranose) composed of mannose. Mannose and galactose are constituted in a ratio of 2: 1. Its main chain has a linear structure due to β-bond of mannose, and since the hydroxyl group in the guar gum molecule exists on the cis side, when the guar gum comes into contact with a substance having a hydroxyl group such as cellulose, the hydroxyl groups of each other Are easy to bond and a strong bond is easily formed.

  The guar gum derivatives used in the present invention include a cationized guar gum obtained by modifying guar gum with a quaternary ammonium salt, a carboxymethylated guar gum added with a carboxymethyl group, a hydroxypropyl guar gum added with a hydroxypropyl group, and a guar gum modified with a cationic property. Amphoteric guar gum, which is a mixture of a guar gum modified product having an anionic property, and has an affinity for the cellulose that guar gum has, and is stably dispersed in the ink composition, resulting in a bulky aggregation of the pigment. By forming the aggregate, it can be preferably used because the coloring property of the handwriting is improved. In particular, when writing on the surface of a writing material such as a cloth having a large gap between fibers, it can be suitably used by using a water-based ink composition for cloth containing a guar gum derivative as in the present invention. is there.

Among these guar gum derivatives, in combination with a poorly water-soluble resin described later in the ink composition, considering that it is easy to improve the color development of handwriting, cationized guar gum, carboxymethylated guar gum, hydroxy Propyl guar gum is preferred.
In particular, hydroxypropyl guar gum forms a cross-linked structure in the ink composition, and a bulky pigment aggregate is easily formed. Therefore, hydroxypropyl guar gum is effective in improving the color developability of handwriting and can be preferably used. Further, when hydroxypropyl guar gum is used, it is easy to obtain an effect of improving water resistance and lubricity. Therefore, when used for a ballpoint pen, the lubricating effect of the ball is obtained and the writing quality is easily improved, which is effective.

  The guar gum derivative used in the present invention is a cationized guar gum, which is modified with glycidyltrimethylammonium chloride to obtain O- [2-hydroxy-3- (trimethylammonio) propyl] guar gum chloride. Series (trade names: JAGUAR C-14S, JAGUAR C-17, JAGUARC-500, JAGUAR OPTIMA, JAGUAR EXCEL, manufactured by Sanki Co., Ltd.), and as carboxymethylated guar gum, trade name: MEYPROID840 (Tricrystal Manufactured by the company), as the hydroxypropyl guar gum, JAGUAR HP series (manufactured by Sanki Co., Ltd.), and as the amphoteric guar gum, trade name: MEYPROID K (manufactured by Sanki Co., Ltd.) Company Ltd.) and the like, can be preferably used.

  When the cationized guar gum is used in the aqueous ink composition of the present invention, the pigment preferably has a negative surface charge in the ink composition. Since the cationized guar gum is ionized in the ink composition to become a cation, this combination makes it easy for the pigment and the cationized guar gum to be adsorbed by an electric attractive force to form a bulky agglomerate. The color developability and the fixability can be improved.

  When the carboxymethylated guar gum is used in the aqueous ink composition of the present invention, the pigment preferably has a positive surface charge in the ink composition. Since carboxymethylated guar gum is ionized in the ink composition to become an anion, this combination makes it easier for the pigment and carboxymethylated guar gum to adsorb by electric attraction and form bulky aggregates. Further, the color development property and fixing property of the handwriting can be improved.

In addition, cationized guar gum and hydroxypropyl guar gum are easily neutralized in the ink composition, so that the effect of improving the color development and fixability of the handwriting is easily expressed. It is preferable to use a neutralizing agent. Specific examples of the neutralizing agent include organic acids such as citric acid, lactic acid, malic acid and acetic acid, and inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid, which are preferably used. In view of good dispersion stability of the aggregate composed of cationized guar gum or hydroxypropyl guar gum and pigment in the ink composition, the neutralizing agent is more preferably an organic acid.
The content of the neutralizing agent may be an amount such that the pH value of the ink composition containing the neutralizing agent is 6 to 7, and can be arbitrarily set according to the content of the cationized guar gum or hydroxypropyl guar gum. .

  The content of the guar gum derivative in the present invention is preferably 0.005% by mass to 1% by mass with respect to the total amount of the ink composition, and more preferably 0.03% by mass to 0.5% by mass. More preferred. More preferably, it is 0.05 mass%-0.3 mass%. When the content of the guar gum derivative is within the above range, the ink viscosity is excessively high and the ink discharge property is not lowered when writing, and adsorbs with the pigment to form a bulky agglomerate. The color developability can be improved.

  Further, in consideration of the fixability, color developability and writing property of handwriting, when the total content of the pigment with respect to the total amount of the ink composition is U and the total content of the guar gum derivative with respect to the total amount of the ink composition is V, V / U is preferably 0.0005 ≦ V / U ≦ 0.05, more preferably 0.001 ≦ V / U ≦ 0.03. In further consideration, 0.002 ≦ V / U ≦ 0.025 is preferred. As long as it is within the above numerical range, the pigment is more easily fixed on the surface of the writing surface, the color development is good, the viscosity of the ink composition is not too high, and the ink ejection property is good. It is because it is easy to make it excellent writing property.

(Slightly water-soluble resin)
The water-based ink composition according to the present invention contains a hardly water-soluble resin. The poorly water-soluble resin is a resin having a solubility in water (amount of solute with respect to 100 g of water) of less than 1.0 g. In the ink composition, the above-mentioned bulky aggregate, pigment, and polyolefin described later By bonding to the particles and adhering to the writing surface at the time of writing, the fixability and abrasion resistance of the handwriting are improved, and the coloring property of the handwriting is improved. Therefore, in the water-based ink composition of the present invention, the combination of the guar gum derivative and the poorly water-soluble resin improves the fixability of the handwriting and the color developability, so it is important to use both.
In the present invention, the poorly water-soluble resin is preferably used as an emulsion or a dispersion, whereby the poorly water-soluble resin can take a stable dispersed state.

Specific examples of the poorly water-soluble resin used in the ink composition of the present invention include acrylic resins, urethane resins, styrene-butadiene resins, alkyd resins, ketone resins, sulfoamide resins, maleic acid resins, and polyvinyl acetate resins. , Ethylene vinyl acetate resin, vinyl chloride vinyl acetate resin, copolymer of styrene and maleate ester, styrene-acrylonitrile resin, cyanate modified polyalkylene glycol, ester gum, xylene resin, urea resin, urea aldehyde resin, phenol resin, Alkylphenol resin, terpene phenol resin, rosin resin and its hydrogenated compounds, rosin phenol resin, polyvinyl butyral, polyvinyl acetal, polyvinyl alkyl ether, polyamide resin, polyolefin resin, nylon resin, polyester resin Can cyclohexanone resins can include, can be preferably used. These can be used alone or in combination of two or more.
In consideration of improvement in handwriting color development, handwriting fixability, and abrasion resistance, the composition of the present invention may contain at least one selected from polyolefin resins, acrylic resins, nylon resins, and polyester resins. preferable. In consideration of the handwriting performance, the composition further preferably contains a polyolefin resin or an acrylic resin, and particularly preferably contains a polyolefin resin.
By including a polyolefin resin or an acrylic resin, the ink composition of the present invention can achieve both good color developability and high handwriting fixability and abrasion resistance. It is effectively expressed by using the poorly water-soluble resin together.

Examples of the polyolefin resin used in the present invention include polymers made of olefins such as ethylene, propylene, or butene, as well as polymers and modified products of olefins and monomers other than olefins. Polyethylene, polypropylene, polybutene, ethylene propylene copolymer, ethylene butene copolymer, propylene butene copolymer, ethylene propylene butene copolymer, copolymer of ethylene and acrylic acid, copolymer of ethylene and methacrylic acid A polymer, a copolymer of ethylene and maleic anhydride, a copolymer of ethylene and vinyl acetate, or the like can be preferably used. In consideration of the color developability and fixability of the water-based ink composition, the polyolefin resin used in the ink composition is more preferably a copolymer of ethylene and acrylic acid, and more preferably a copolymer of ethylene and acrylic acid. Particularly preferred is a polymer modified to a self-emulsifying type.
Specific examples of the polyolefin resin suitable for the present invention include a polyolefin resin (manufactured by Sumitomo Seika Co., Ltd., product name: Syxen A type, which is obtained by alkali neutralizing a copolymer of ethylene and acrylic acid and making it a self-emulsifying type. L type, N type) and modified polyolefin resin (manufactured by Unitika Ltd., product names: Arrow Base C series, D series, S series).

  The acrylic resin used in the present invention is a polymer containing acrylic acid or methacrylic acid in the repeating unit, and it is possible to use a single type or a plurality of types of acrylic resins. Specifically, acrylic ester resins, acrylic styrene resins, acrylic silicon resins, acrylic urethane resins, acryl nitrile resins, acrylic styrene nitrile resins, acrylic vinyl acetate resins, methacrylic ester resins, and the like can be preferably used. Among these acrylic resins, an acrylic styrene resin is preferable, and a self-crosslinking acrylic styrene copolymer resin is more preferable in view of further improving the fixability and scuff resistance of handwriting.

  Although the molecular weight of the acrylic resin is not particularly limited, those having a mass average molecular weight of 1,000 to 1,000,000 are generally used.

  Specific examples of the acrylic resin that can be used in the present invention include the JONCRYL series (manufactured by BASF Corporation), the primal AC series (manufactured by Rohm and Haas Japan Co., Ltd.), the JSRAE series (manufactured by JSR Corporation), Examples include the vinyl series (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), the nicazole series (manufactured by Nippon Carbide Industries Co., Ltd.), and the ultrasol series (manufactured by Aika Industry Co., Ltd.).

  The nylon resin or polyester resin used in the present invention is not particularly limited as long as it exhibits the effect of improving the color developability of the ink composition, the fixability of handwriting, and the abrasion resistance. A polymer having an amide bond repeating unit and an aliphatic skeleton, for example, may be mentioned Sepoljon PA (manufactured by Sumitomo Seika Co., Ltd.) which is a copolymer nylon. Examples of polyester resins include: Saturated copolyester resins (product names: Elitel KA series, KT series, manufactured by Unitika Ltd.), which are polycondensates of polyvalent carboxylic acids and polyhydric alcohols, are preferred.

  The content of the hardly water-soluble resin is preferably 0.1% by mass to 10% by mass with respect to the total amount of the ink composition, and more preferably 0.2% by mass to 5% by mass. More preferably, it is 0.5-3 mass%. Further, when the total content of the guar gum derivative with respect to the total amount of the ink composition is V and the total content of the poorly water-soluble resin with respect to the total amount of the ink composition is X, X / V is 5 ≦ X / V ≦ 75. Preferably, 10 ≦ X / V ≦ 50, more preferably 15 ≦ X / V ≦ 40. If the ratio of the content of the hardly water-soluble resin or the content of the hardly water-soluble resin and the content of the guar gum derivative is within the above numerical range, the fixability to the writing surface of the pigment is further improved and excellent. This is because it is easy to write.

  In the present invention, the pigment, the guar gum derivative and the poorly water-soluble resin are used in combination, and the content ratio of the pigment and the poorly water-soluble resin, and the content ratio of the guar gum derivative and the poorly water-soluble resin, It is possible to improve handwriting fixability and color developability, and to achieve excellent writing properties, and it is important to use these components in combination to achieve a content ratio within a specific range. It is.

(solvent)
Examples of the solvent include water and a mixed solvent of water and an organic solvent. As water, conventional water such as ion-exchanged water, distilled water and tap water can be used. When a mixed solvent of water and an organic solvent is used, ethanol, normal propanol, isopropanol or the like is used as the organic solvent. be able to. Although diols or triols having a relatively high boiling point such as glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol and the like can be used, it is preferable that the blending amount is small. In addition, it is preferable that the content rate of an organic solvent is 1 mass%-30 mass% with respect to the total mass of a solvent, and it is more preferable that it is 1 mass%-20 mass%. In particular, the content of diols or triols is preferably 1% by mass to 10% by mass. If the content of the organic solvent is within the above numerical range with respect to the total mass of the solvent, it is possible to achieve both good dry-up performance and handwriting dryness.

  The content of the solvent in the water-based ink composition is preferably 20% by mass to 90% by mass and more preferably 30% by mass to 80% by mass with respect to the total amount of the ink composition. If the content of the solvent is within the above numerical range, each component can be stably dissolved or dispersed, and a bulky aggregate that is easily redispersible in an aqueous ink composition can be produced.

(Penetration agent)
The water-based ink composition of the present invention contains a penetrating agent to lower the surface tension of the ink composition to improve wettability, and to improve the writing property on non-penetrating surfaces such as glass, plastic, and wax that are easy to repel ink. It is possible.
Examples of the penetrant used in the present invention include a phosphate ester surfactant, a surfactant having an acetylene bond, a fluorosurfactant, a silicone surfactant, and a succinic surfactant. It is preferable to select and use more than one species. By incorporating the surfactant as described above into the water-based ink composition, the surface tension is lowered to improve the wettability of the water-based ink composition with respect to a non-permeable recording medium such as a film, and the non-permeable recording medium The writing property can be improved by improving the handwriting scraping and hollowing out of the ink.

Among the penetrants, preferred penetrants according to the present invention are phosphate ester surfactants and surfactants having an acetylene bond.
Phosphate-based surfactant is a surfactant having a phosphate group in its structure, and as described above, it has the effect of reducing the surface tension of the water-based ink composition and improving the writing property on the non-penetrating surface. In addition, when used as ink for writing on a ballpoint pen, the phosphate group is adsorbed on the metal surface such as a ball or ball chip, and exhibits lubricity, thereby reducing the wear of the ball seat and improving the writing quality. Bring.

  The phosphate ester-based surfactant used in the present invention has an HLB value = 7 + 11.7 log (Mw / Mo), (Mw) as a general formula in consideration of the wettability improving effect and the dissolution stability in the ink composition. The molecular weight of the hydrophilic group, Mo; the molecular weight of the lipophilic group) is preferably 4-18, more preferably 6-17.

Specific examples of the phosphate ester surfactant include Prisurf A212C (tridecyl alcohol), A208B (lauryl alcohol), A208F (short) from the Prisurf series (Daiichi Kogyo Seiyaku Co., Ltd.). Chain alcohol type), A215C (tridecyl alcohol type), A219B (lauryl alcohol type), and AL (styrene type), and one type or two or more types can be preferably used.
In consideration of wettability improvement effect and metal surface lubricity improvement effect, Plysurf A215C, A219B, and AL are more preferable among the above.

  A surfactant having an acetylene bond has very high stability, and can continuously improve wettability and improve writing performance. Examples of the surfactant having an acetylene bond include acetylene alcohol surfactants and acetylene glycol surfactants. In particular, an acetylene glycol-based surfactant is preferable because it is excellent in suppressing the generation of bubbles, and it is easy to exert the effect of smoothing the surface of the handwriting by suppressing the foaming of the handwriting during writing.

  The surfactant having an acetylene glycol bond used in the present invention has a general formula of HLB value = 20 × (mass% of hydrophilic group) = in consideration of the wettability improving effect and the dissolution stability in the ink composition. It is preferable that the HLB value calculated | required from 20x (the sum total of the formula weight of a hydrophilic group / molecular weight of surfactant) has an HLB value of 4-18, and it is more preferable to have an HLB value of 6-15, 7- It is particularly preferred to have an HLB value of 11.

Specific surfactants having an acetylene bond include olphine D-10A, olphin D-10PG, olphin E1004, olphin E1010, olphin E1020, olphin E1030W, olphin PD-001, olphin PD-002W, olphin PD-004, Orphin EXP. 4001, Olfine EXP. 4200, Olfine EXP. 4123, Olfine EXP. 4300, Surfinol 61, Surfinol 82, Surfinol 104 series, Surfinol 420, Surfinol 440, Surfinol 465, Surfinol 485, Surfinol SE, Surfinol SE-F, Surfinol 2502, Dynal 604, Dynal 607 Manufactured by Nissin Chemical Industry Co., Ltd., acetylenol EH, acetylenol EL, acetylenol E13T, acetylenol E40, acetylenol E60, acetylenol E81, acetylenol E100, acetylenol E200, acetylenol E300, acetylenol 85, manufactured by Kawaken Fine Chemical Co., Ltd. 1 type or 2 types or more can be preferably used. Of the above surfactants, dynol 604, dynol 607, and surfinol 2502 are particularly preferable in consideration of wettability improvement effect and handwriting foaming suppression effect.
In the water-based ink composition of the present invention, it is preferable to use the phosphoric ester surfactant and a surfactant having an acetylene glycol bond in combination, and by using both in combination, the writing property on the non-penetrating surface is further enhanced.

  The content of the penetrant in the present invention is preferably 0.001% by mass to 1.5% by mass and preferably 0.01% by mass to 0.7% by mass with respect to the total amount of the ink composition. More preferred. When the content is within the above numerical range, it is possible to achieve both the suppression of foaming of handwriting and the improvement of wettability.

  When the penetrant is used in combination, particularly when a phosphate ester surfactant and a surfactant having an acetylene glycol bond are used in combination, the total content of the phosphate ester surfactant with respect to the total amount of the aqueous ink composition is set to Y. When the total content of the surfactant having an acetylene glycol bond in the aqueous ink composition is Z, Y / Z is preferably 0.5 ≦ Y / Z ≦ 15, and 1 ≦ Y / Z ≦ 5 is more preferable. When Y / Z is within the above numerical range, it is possible to achieve both good writing properties for the non-penetrating surface, lubricity, suppression of foaming of handwriting, and dissolution stability of the penetrant.

(Polyolefin resin particles)
Further, the ink composition of the present invention can impart higher fixability and abrasion resistance to the handwriting by using polyolefin resin particles. Polyolefin resin particles are fine particles with surface lubricity consisting of polyolefins such as polyethylene and polypropylene, and mixtures thereof. When handwriting is subjected to external force such as rubbing, it prevents excessive force from being applied to the handwriting. This is a type of polyolefin resin different from the aforementioned poorly water-soluble resin.
The polyolefin may be a linear polyolefin, a polyolefin having a branched chain, a modified polyolefin having a functional group introduced therein, or the like. For example, when polyethylene is used as the polyolefin, low density polyethylene, linear low molecular weight polyethylene, high density polyethylene, modified polyethylene, modified high density polyethylene, and the like can be used. Although the molecular weight of these polyolefins is not particularly limited, for example, polyolefins having a mass average molecular weight of 500 to 100,000 are preferable, and the weight average molecular weight is more preferably 800 to 5,000. If the weight average molecular weight of the polyolefin resin particles is within the above numerical range, when this water-based ink composition is used for a writing instrument such as a marker, writing is performed with respect to the formed writing line, The high abrasion resistance accompanying it can be provided and a favorable handwriting can be obtained. The polyolefin resin particles may contain a material other than polyolefin as required.
Therefore, it is preferable to use the poorly water-soluble resin and the polyolefin resin in combination because the color development property of the handwriting, the fixing property of the handwriting, and the abrasion resistance are more likely to be improved, and in particular, writing on an impermeable recording medium. When writing, it is easy to write well.

  The shape of the polyolefin resin particles is not particularly limited, and can be any shape such as an indefinite shape, a spherical shape, a needle shape, a plate shape, or a square shape.

  The average particle diameter of the polyolefin resin particles is preferably 0.1 μm to 35 μm. If the average particle diameter of the polyolefin resin particles is within the above numerical range, when writing using this water-based ink composition for a writing instrument such as a marker, higher slipperiness with respect to the writing line formed, The high abrasion resistance accompanying it can be provided and a favorable handwriting can be obtained. Further, from the viewpoint of imparting high abrasion resistance, the thickness is more preferably 0.1 μm to 25 μm, further preferably 0.5 μm to 20 μm, and particularly preferably 0.5 μm to 15 μm. The average particle diameter of the polyolefin resin particles can be measured by a Coulter counter method.

  Specific examples of polyolefin resin particles that can be used in the present invention include Chemipearl W series, Chemipearl M series (both trade names, manufactured by Mitsui Chemicals), CERAFLOUR series, Aquacer series, Aquamat series (both products) Name, manufactured by Big Chemie Co., Ltd.).

  The content of the polyolefin resin particles in the water-based ink composition is preferably 0.01% by mass to 10% by mass and more preferably 0.2% by mass to 5% by mass with respect to the total amount of the ink composition. Preferably, it is most preferable in it being 0.5 mass%-5 mass%. When the content of the polyolefin resin particles is within the above numerical range, the ink ejection properties can be maintained, and higher slipperiness can be imparted to the writing lines.

(Other)
In addition, the water-based ink composition may contain a constitution material, an antiseptic agent, an antifoaming agent, a rust preventive agent, a pH adjuster, an air bubble inhibitor, an air bubble absorber, a shear thinning agent, a viscosity adjuster, and the like as necessary. May be included.

(Water-based ink composition for writing instruments)
The viscosity of the water-based ink composition according to the present invention is preferably low. The viscosity of the composition can be measured using an E-type rotational viscometer (manufactured by Brookfield). Specifically, the viscosity of the water-based ink composition at 20 ° C. is preferably 1 to 100 mPa · s, and preferably 2 to 70 mPa · s when measured at a rotation speed of 100 rpm (shear speed 380 sec ⁻¹ ). It is more preferable that More preferably, it is 5-40 mPa * s. Moreover, when it measures on the conditions whose rotation speed is 10 rpm (shear rate 38sec < ^-1 >), it is preferable that it is 1-600 mPa * s, and it is more preferable that it is 5-200 mPa * s. More preferably, it is 10-100 mPa * s. When the rotation speed is 1 rpm (shear speed 3.8 sec ⁻¹ ), it is preferably 1 to 3000 mPa · s, and more preferably 10 to 1500 mPa · s. More preferably, it is 20-400 mPa * s. If the viscosity of the water-based ink composition is within the above numerical range, ink ejection properties when used in a writing instrument such as a marker can be improved, and writing performance on a non-permeable recording medium such as a film can be improved. To do.

The surface tension of the water-based ink composition is preferably 10 to 40 mN / m in a 20 ° C. environment. If the surface tension is within the above numerical range, it tends to be able to prevent bleeding of writing lines and back-through to paper, improve the wettability of the water-based ink composition, and to the non-permeable recording medium Writability can be improved with good handwriting and voids. In consideration of writability, the surface tension of the water-based ink composition is preferably 20 to 30 mN / m. In particular, in the present invention, the surface activity having a phosphate ester surfactant or an acetylene bond in the structure. The agent is preferably used because it is suitable for adjusting the surface tension of the water-based ink composition.
The surface tension is determined by measuring by a vertical plate method using a platinum plate with a surface tension measuring instrument manufactured by Kyowa Interface Science Co., Ltd. in a 20 ° C. environment.

The pH value of the water-based ink composition is preferably 6 to 10, and more preferably 7 to 9. If the pH value of the water-based ink composition is within the above numerical range, it is possible to suppress discoloration and excessively high viscosity of the ink composition, and the ink composition is inorganic having silica or alumina. When a pigment treated with an oxide is used, the dispersibility of the pigment can be further improved by further using the pigment dispersant.
Moreover, when using a guar gum derivative like this invention, in order to acquire the above effects, if the pH value of a water-based ink composition shall be 6-10, a guar gum derivative will be stabilized in ink, and pigment of Since it is easier to improve the dispersion stability and the color development of handwriting, the pH value of the guar gum derivative is preferably 6 to 10, and more preferably, the pH value is preferably 6 to 8. The pH value can be measured, for example, at 20 ° C. with an IM-40S type pH meter (manufactured by Toa DKK Corporation).

  The reason why the water-based ink composition according to the present invention exhibits excellent color developability and fixability has not been elucidated in detail, but is presumed to be due to the following mechanism.

  When a pigment is used as the water-based ink composition, the pigment is pulverized and mixed so that the ink composition can obtain a sufficient coloring power. The ink composition thus obtained has a clear color tone, and a clear handwriting is obtained when writing on a smooth or dense writing surface, while a paper having a large gap between fibers of paper, cloth, etc. When writing, the pigment crushed into fine particles passes through the gaps between the fibers of paper, cloth, etc., and enters the periphery of the writing part and the inside of the writing body, resulting in a reduction in the coloring of the handwriting. .

  The water-based ink composition in the present invention solves such problems by further combining the guar gum derivative and the poorly water-soluble resin so that the content ratio is in a specific range.

  In the case of the water-based ink composition according to the present invention, the crushed pigment particles and the guar gum derivative are adsorbed to form a bulky aggregate. As a result, when writing on a writing material having a large gap between fibers, such as paper and cloth, a bulky aggregate is likely to be adsorbed to the fiber on the surface of the writing surface without passing through the gap between fibers. For this reason, it is considered that the color developability and the handwriting fixability are improved. Furthermore, since the poorly water-soluble resin can be combined with a pigment or a bulky aggregate to improve the fixability and abrasion resistance of the pigment or the bulky aggregate, the color development of the handwriting is further improved. be able to. In particular, when writing on the surface of a writing material such as a cloth having a large gap between fibers, it can be suitably used by making it a water-based ink composition for cloth.

  The ink composition of the present invention further contains a penetrating agent to lower the surface tension of the ink composition to improve wettability, and to improve the writing property on non-penetrating surfaces such as glass, plastic, and wax that are easy to repel ink. It is possible.

  In addition, the water-based ink composition according to the present invention is remarkably improved in abrasion resistance by containing polyolefin resin particles. This reason is presumed to be due to the following reasons. The handwriting formed using the water-based ink composition according to the present invention is formed by arranging the above-described bulky aggregate and polyolefin resin particles on the surface of the writing. Since the surface of the polyolefin resin particles has low frictional resistance, when the handwriting surface is abraded, excessive external force is suppressed from being applied to the handwriting and is not affected by peeling of the handwriting. Then, as the rubbing progresses, force is applied to the polyolefin resin particles and deformation occurs due to frictional heat and the like, thereby covering the surface of the handwriting. As a result, it is presumed that the surface of the handwriting is coated with the polyolefin resin, and the coefficient of friction on the surface of the handwriting is lowered and the handwriting is protected by the polyolefin resin.

  The water-based ink composition according to the present invention can be produced by any conventionally known method. Specifically, it can be produced by blending the necessary amounts of the above components and mixing them with various agitators such as propeller agitation, homodisper, or homomixer, and various dispersers such as a bead mill.

(Writing instrument)
The water-based ink composition of the present invention is used for a writing pen such as a fountain pen using a marking pen, a ball-point pen, or a metal pen point, such as a fiber tip, a felt tip, a plastic tip, or a pen tip or a ball-point tip. Can do. Among these, in order to improve the writing property with respect to a non-permeable recording medium such as a film, the pen tip is preferably a pen core or a ballpoint pen tip made of a fiber chip, a felt chip, or a plastic chip. Furthermore, it is more preferable to use it for a marking pen or a ballpoint pen.
The pore diameter of the pen core can be arbitrarily set as long as the bulky aggregate can pass through, and the porosity is preferably 50 to 80%. When the porosity of the pen core is within the above numerical range, the pigment is not clogged and an appropriate ink discharge amount can be maintained.

  The writing instrument of the present invention may be configured to be directly filled with a water-based ink composition, or may be provided with an ink container or ink occlusion body that can be filled with a water-based ink composition. In order to redisperse the pigment, the ink container preferably contains a stirring body such as a stirring ball for stirring the ink. Furthermore, examples of the shape of the stirring body include a spherical body and a rod-shaped body. The material of the stirrer is not particularly limited, but specific examples include metal, ceramic, resin, glass, etc. Among these, considering the stirring force for redispersing the pigment A metal material is preferably used, and a glass material is preferably used in consideration of cost. In addition, you may use multiple types and several types of materials for a stirring body.

  The appearance mechanism of the writing instrument of the present invention is not particularly limited, and examples thereof include a cap type, a knock type, a rotary type, and a slide type that include a cap that covers the pen tip. Further, it may be a retractable type that can accommodate the pen tip in the shaft cylinder.

  Further, the ink supply mechanism in the writing instrument is not particularly limited, for example, (1) a mechanism for supplying an ink guide core composed of a fiber bundle or the like as an ink flow rate adjusting member, and supplying a water-based ink composition to the pen tip; (2) A comb groove-shaped ink flow rate adjusting member is provided, and a mechanism for interposing the ink flow rate adjusting member to supply the water-based ink composition to the pen tip. (3) An ink flow rate adjusting member by a valve mechanism is provided. Examples thereof include a mechanism for supplying the ink composition first, and (4) a mechanism for supplying the water-based ink composition directly to the pen tip from the ink container or the shaft cylinder provided with the pen tip.

  In one embodiment, the writing instrument is a marking pen, and the nib is not particularly limited, and may be, for example, a fiber chip, a felt chip, a plastic chip, or the like. It may be a brush pen type.

  In one embodiment, the writing instrument is a ballpoint pen, and is preferably a ballpoint pen provided with an ink backflow preventer.

The present invention will be described below with reference to various examples.
Example 1
A water-based ink composition was obtained according to the following procedure. Raw materials and blending amounts are as follows.
1. The guar gum derivative was dissolved in half the amount of ion exchange water of the following blending amount, and citric acid was added later to obtain an aqueous solution of guar gum derivative.
2. The remaining amount of ion-exchanged water and raw materials other than guar gum derivatives and citric acid were mixed at room temperature for 1 hour to obtain a dispersion such as a pigment.
3. The ink composition for writing instruments was obtained by mixing the said guar gum derivative aqueous solution and dispersions, such as a pigment, at room temperature for 1 hour. The viscosity of the obtained water-based ink composition was measured with an E-type rotational viscometer (DV-II + Pro, cone-type rotor CPE-42, manufactured by Brookfield), and the viscosity at a shear rate of 3.8 sec ⁻¹ (rotational speed 1 rpm). Was 179.4 mPa · s.
Furthermore, as a result of measuring the pH of the water-based ink composition at 20 ° C. using an IM-40S type pH meter (manufactured by Toa DKK Co., Ltd.), the pH was 8.5.
Further, the surface tension of the obtained water-based ink composition was measured by a surface tension measuring instrument (in a 20 ° C environment, a vertical plate method, manufactured by Kyowa Interface Science Co., Ltd.), and found to be 36.5 mN / m.

・ Pigment 30% by mass
(Silica oxide, titanium oxide surface-treated with alumina, average particle size 0.26 μm, manufactured by Sakai Chemical Industry Co., Ltd., trade name: GTR-100)
・ Pigment dispersant 1.5% by mass
(Pigment dispersant having a cationic adsorption group, solid content 52%, manufactured by Big Chemie Co., Ltd., trade name: DISPERBYK-184)
・ Guar gum derivative 0.1% by mass
(Cationized guar gum, manufactured by Sanki Co., Ltd., trade name: JAGUAR C-500STD)
・ Slightly water-soluble resin 10% by mass
(Self-emulsifying type polyolefin dispersion, solid content 25%, manufactured by Sumitomo Seika Co., Ltd., trade name: Seixen L)
・ Citric acid 0.1% by mass
・ Diethylene glycol 2% by mass
・ Defoamer 0.3% by mass
(Silicone-based antifoaming agent, manufactured by BYK Chemie, trade name BYK-024)
-Preservative 0.2% by mass
(Benzisothiazoline-3-one, manufactured by Lonza Japan Ltd., trade name: Proxel XL-2)
・ Ion-exchanged water 55.80% by mass

(Examples 2-29, Comparative Examples 1-6)
The ink compositions of Examples 2 to 29 and Comparative Examples 1 to 6 were obtained by changing the types and addition amounts of the components to be blended as shown in Tables 1 to 5 with respect to Example 1.
In addition, about the ink composition of Examples 8, 9, and 10 and Comparative Examples 1 and 5, the ink composition for writing instruments was obtained by stirring and mixing the whole quantity of a raw material for 1 hour at room temperature.
In the ink compositions of Examples 1 to 29 and Comparative Examples 1 to 6, the sign of the surface charge value of the pigment surface-treated with an inorganic oxide was as follows.
Examples 1 to 7, 10 to 17, 19 to 29 (negative values)
Comparative examples 1 to 4 and 6 (negative values)
Examples 8 to 9 (positive values)
Comparative example 5 (positive value)

上記実施例で使用した材料の詳細は以下の通りである。
・顔料（１）シリカ、アルミナにより表面処理された酸化チタン（平均粒子径：０．２６μｍ、堺化学工業株式会社製、商品名：ＧＴＲ−１００）
・顔料（２）シリカ、アルミナにより表面処理された酸化チタン（平均粒子径：０．２５μｍ、テイカ株式会社製、商品名：ＪＲ−７０７）
・顔料（３）シリカ、アルミナ、酸化亜鉛により表面処理された酸化チタン（平均粒子径：０．２７μｍ、テイカ株式会社製、商品名：ＪＲ−７０１）
・顔料（４）アルミナにより表面処理された酸化チタン（平均粒子径：０．２３μｍ、堺化学工業株式会社製、商品名：Ｒ−３２）
・顔料（５）アルミナにより表面処理された酸化チタン（平均粒子径：０．２１μｍ、テイカ株式会社製、商品名：ＪＲ−４０５）
・顔料（６）有機顔料水分散体（顔料含有比率２６質量％、山陽色素株式会社製、商品名ＳＡＮＤＹＥＳＵＰＥＲＣＯＬＯＵＲ ＢＬＵＥ ＧＬＬ−Ｅ）
・顔料（７）有機顔料水分散体（顔料含有比率３０質量％、山陽色素株式会社製、商品名ＳＡＮＤＹＥＳＵＰＥＲＣＯＬＯＵＲ ＲＥＤ １３２１−Ｅ）
・顔料（８）カーボンブラック水分散体（顔料含有比率２８．５質量％、山陽色素株式会社製、商品名ＳＡＮＤＹＥＳＵＰＥＲＣＯＬＯＵＲ ＢＬＡＣＫ Ｃ−Ｅ）
・顔料分散剤（１）カチオン性吸着基を有する顔料分散剤（固形分含有量５２％、ビッグケミー株式会社製、商品名：ＤＩＳＰＥＲＢＹＫ−１８４）
・顔料分散剤（２）アニオン性吸着基を有する顔料分散剤（固形分含有量４０％、ビックケミー株式会社製、商品名：ＤＩＳＰＥＲＢＹＫ−１９０）
・グアーガム誘導体（１）カチオン化グアーガム（三晶株式会社製、商品名：ＪＡＧＵＡＲ Ｃ−５００ＳＴＤ）
・グアーガム誘導体（２）カルボキシメチル化グアーガム（三晶株式会社製、商品名：ＭＥＹＰＲＯＩＤ ８４０Ｄ）
・グアーガム誘導体（３）両性グアーガム（三晶株式会社製、商品名：ＭＥＹＰＲＯＩＤ Ｋ）
・グアーガム誘導体（４）ヒドロキシプロピルグアーガム（三晶株式会社製、商品名：ＪＡＧＵＡＲ ＨＰ１２０）
・難水溶性樹脂（１）自己乳化型ポリオレフィン樹脂ディスパージョン（固形分含有量２５％、住友精化株式会社製、商品名：ザイクセンＬ）
・難水溶性樹脂（２）アクリル樹脂エマルション（固形分含有量４２％、ＢＡＳＦ株式会社製、商品名：ＪＯＮＣＲＹＬ ＰＤＸ−７３７０）
・ポリオレフィン樹脂粒子（１）変性ポリエチレンワックス（平均粒子径：８μｍ、固形分：１００％、ビックケミー株式会社製、商品名：ＣＥＲＡＦＬＯＵＲ９２９）
・ポリオレフィン樹脂粒子（２）変性ポリエチレンワックス（平均粒子径：６μｍ、固形分：１００％、ビックケミー株式会社製、商品名：ＣＥＲＡＦＬＯＵＲ９２５）
・ポリオレフィン樹脂粒子（３）低密度ポリエチレン（平均粒子径：６μｍ、４０％ディスパージョン、三井化学株式会社製、商品名：ケミパールＭ２００）
・ポリオレフィン樹脂粒子（４）低分子ポリエチレン（平均粒子径：０．６μｍ、 ４０％ディスパージョン、三井化学株式会社製、商品名：ケミパールＷ４００５）
・浸透剤（１）リン酸エステル系界面活性剤（第一工業製薬株式会社製、商品名：プライサーフ２０８Ｎ、ＨＬＢ：７）
・浸透剤（２）リン酸エステル系界面活性剤（第一工業製薬株式会社製、商品名：プライサーフＡ２１９Ｂ、ＨＬＢ：１６．２）
・浸透剤（３）アセチレン結合を有する界面活性剤（日信化学工業株式会社製、商品名：ダイノール６０４、ＨＬＢ：８）
・粘度調整剤（１）架橋型アクリル酸重合体（和光純薬工業株式会社製、商品名：ハイビスワコー１０４）
・粘度調整剤（２）架橋型アクリル酸重合体（和光純薬工業株式会社製、商品名：ハイビスワコー１０５）
・消泡剤 シリコーン系消泡剤（ビッグケミー株式会社製、商品名：ＢＹＫ−０２４）
・防腐剤 ベンゾイソチアゾリン−３−オン（ロンザジャパン株式会社、商品名：Ｐｒｏｘｅｌ ＸＬ−２）
・グアーガム誘導体用中和剤 クエン酸
・ｐＨ調整剤
・ジエチレングリコール

The details of the materials used in the above examples are as follows.
Pigment (1) Titanium oxide surface-treated with silica and alumina (average particle size: 0.26 μm, manufactured by Sakai Chemical Industry Co., Ltd., trade name: GTR-100)
Pigment (2) Titanium oxide surface-treated with silica and alumina (average particle size: 0.25 μm, manufactured by Teika Co., Ltd., trade name: JR-707)
Pigment (3) Titanium oxide surface-treated with silica, alumina and zinc oxide (average particle size: 0.27 μm, manufactured by Teika Co., Ltd., trade name: JR-701)
Pigment (4) Titanium oxide surface-treated with alumina (average particle size: 0.23 μm, manufactured by Sakai Chemical Industry Co., Ltd., trade name: R-32)
Pigment (5) Titanium oxide surface-treated with alumina (average particle size: 0.21 μm, manufactured by Teika Co., Ltd., trade name: JR-405)
Pigment (6) Organic pigment aqueous dispersion (pigment content ratio 26 mass%, manufactured by Sanyo Dye Co., Ltd., trade name SANDYESUPERCOLOR BLUE GLL-E)
Pigment (7) Organic pigment aqueous dispersion (pigment content ratio 30% by mass, manufactured by Sanyo Dye Co., Ltd., trade name SANDYESUPERCOLOR RED 1321-E)
Pigment (8) Carbon black aqueous dispersion (pigment content ratio 28.5% by mass, manufactured by Sanyo Dye Co., Ltd., trade name SANDYESUPERCOLOR BLACK CE)
Pigment dispersant (1) Pigment dispersant having a cationic adsorption group (solid content: 52%, manufactured by Big Chemie Co., Ltd., trade name: DISPERBYK-184)
Pigment dispersant (2) Pigment dispersant having an anionic adsorptive group (solid content 40%, manufactured by Big Chemie Co., Ltd., trade name: DISPERBYK-190)
Guar gum derivative (1) Cationized guar gum (manufactured by Sanki Co., Ltd., trade name: JAGUAR C-500STD)
Guar gum derivative (2) Carboxymethylated guar gum (manufactured by Sanki Co., Ltd., trade name: MEYPROID 840D)
-Guar gum derivative (3) Amphoteric guar gum (manufactured by Sanki Co., Ltd., trade name: MEYPROID K)
Guar gum derivative (4) Hydroxypropyl guar gum (manufactured by Sanki Co., Ltd., trade name: JAGUAR HP120)
・ Slightly water-soluble resin (1) Self-emulsifying type polyolefin resin dispersion (solid content: 25%, manufactured by Sumitomo Seika Co., Ltd., trade name: Xyxen L)
・ Slightly water-soluble resin (2) Acrylic resin emulsion (solid content 42%, manufactured by BASF Corporation, trade name: JONCRYL PDX-7370)
Polyolefin resin particles (1) modified polyethylene wax (average particle size: 8 μm, solid content: 100%, manufactured by Big Chemie Co., Ltd., trade name: CERAFLOUR929)
Polyolefin resin particles (2) modified polyethylene wax (average particle size: 6 μm, solid content: 100%, manufactured by Big Chemie Co., Ltd., trade name: CERAFLOUR 925)
Polyolefin resin particles (3) Low density polyethylene (average particle size: 6 μm, 40% dispersion, manufactured by Mitsui Chemicals, trade name: Chemipearl M200)
Polyolefin resin particles (4) Low molecular polyethylene (average particle size: 0.6 μm, 40% dispersion, manufactured by Mitsui Chemicals, trade name: Chemipearl W4005)
-Penetration agent (1) Phosphate ester surfactant (Daiichi Kogyo Seiyaku Co., Ltd., trade name: Prisurf 208N, HLB: 7)
-Penetration agent (2) Phosphate ester surfactant (Daiichi Kogyo Seiyaku Co., Ltd., trade name: Prisurf A219B, HLB: 16.2)
・ Penetration agent (3) Surfactant having acetylene bond (manufactured by Nissin Chemical Industry Co., Ltd., trade name: Dynol 604, HLB: 8)
・ Viscosity modifier (1) Crosslinkable acrylic acid polymer (Wako Pure Chemical Industries, Ltd., trade name: Hibiswako 104)
・ Viscosity modifier (2) Crosslinkable acrylic acid polymer (Wako Pure Chemical Industries, Ltd., trade name: Hibiswako 105)
-Antifoaming agent Silicone-based antifoaming agent (manufactured by Big Chemie Co., Ltd., trade name: BYK-024)
-Antiseptic benzoisothiazolin-3-one (Lonza Japan Co., Ltd., trade name: Proxel XL-2)
・ Guar gum derivative neutralizer Citric acid ・ pH adjuster ・ Diethylene glycol

(Test and evaluation with ballpoint pen and marking pen)
The prepared water-based ink composition was evaluated as follows. The obtained result was as having described in Tables 1-5.
As the ballpoint pen used in the evaluation test, the following ballpoint pen was prepared and used.
Ballpoint pen: A ballpoint pen tip that rotatably holds a ball with a ball diameter of 1.0 mm is attached to the tip of an ink container (made of nylon), and is directly attached to the ink container that contains a metal ball with a diameter of 5.0 mm. The following tests and evaluations were performed as ballpoint pens filled with the water-based ink compositions obtained in Examples 1 to 27 and Comparative Examples 1 to 6.
Moreover, the following marking pen was created and used for the marking pen used by an evaluation test.
Marking pen: Incorporates a spherical stirring body made of a metal material with a diameter of 8 mm and an ink composition with a volume of 6 cm ³ in an ink container (inner dimensions: length 80 mm, diameter 16 mm) of a marking pen equipped with a pen tip. Then, the water-based ink composition obtained in Examples 28 to 29 was filled, and the pen tip was impregnated with the water-based ink composition, and the pen tip was a bullet-type polyester fiber core pen core with a porosity of 60%. The following tests and evaluations were performed as a marking pen.

(Evaluation of handwriting color development)
Writing was performed on the writing test medium with the above ballpoint pen and marking pen. The color developability of the handwriting at that time was visually observed. In addition, cotton cloth (manufactured by Nisshinbo, No. 60, cotton lawn) and a plastic film (made of polypropylene) were used as a medium for writing test.
A: The handwriting has no color unevenness and is clear B: The handwriting has some color unevenness but has no practical problem C: The handwriting has color unevenness and the density is low. There are practical concerns

(Evaluation of abrasion resistance test)
Writing was performed on a cotton cloth (Nisshinbo Co., Ltd., No. 60, cotton lawn) and a plastic film (made of polypropylene) with the above ballpoint pen and marking pen. After leaving this writing line for 1 day, it was rubbed and rubbed 50 times under a load of 200 g under cotton load (Nisshinbo Co., 60th, Cotton Lawn) using a Gakushin type friction fastness tester (manufactured by Tester Sangyo Co., Ltd.). The later handwriting was compared with the initial handwriting, and the abrasion resistance was evaluated according to the following criteria.
A: No handwriting peeling
B: Slight handwriting peeling but no problem in practical use C: Handwriting peeling D: Many handwriting peeling, impractical

(Evaluation of writability)
A writing test was conducted with the above ballpoint pen and marking pen. The color developability of the handwriting at that time was visually observed. A plastic film (made of polypropylene) was used as a medium for writing tests.
A: No repelling, faintness, good handwriting B: Slightly repelling, fainting but no practical problem C: Repelling, faintness D: Repelling, faintness, handwriting recognition Unusable

(Evaluation of writing quality)
Writing was performed on the writing test medium with the above ballpoint pen, and the writing taste at that time was subjected to sensory evaluation. In addition, a black paper (manufactured by Nagatoya Shoten Co., Ltd., color paper B5 medium thickness black, thickness 0.09 mm, density 80 g / m ² ) was used as a medium for writing test.
A: It was very smooth writing.
B: Smooth writing feeling C: A slightly heavy writing feeling was felt, but it was a level with no practical problem.
D: The writing was heavy and slippery.

Claims (8)

  A water-based ink composition for a writing instrument comprising a pigment, a guar gum derivative, a sparingly water-soluble resin, and water, wherein the total content of the pigment relative to the total amount of the ink composition is U, and the total content of the guar gum derivative relative to the total amount of the ink composition When the amount is V, V / U is 0.0005 ≦ V / U ≦ 0.05, and when the total content of the poorly water-soluble resin relative to the total amount of the ink composition is X, X / V Is a water-based ink composition for a writing instrument, wherein 5 ≦ X / V ≦ 75.   The aqueous ink composition for a writing instrument according to claim 1, wherein the guar gum derivative is one or more selected from carboxymethylated guar gum, cationized guar gum, hydroxypropyl guar gum, and amphoteric guar gum.   The water-based ink composition for a writing instrument according to claim 1 or 2, wherein the hardly water-soluble resin is one or more selected from a polyolefin resin, an acrylic resin, a nylon resin, or a polyester resin.   The water-based ink composition for a writing instrument according to any one of claims 1 to 3, wherein the pigment is a pigment whose surface is coated with silica or alumina.   The water-based ink composition for a writing instrument according to any one of claims 1 to 4, further comprising a polymer dispersant having an anionic adsorbing group or a cationic adsorbing group.   The water-based ink composition for a writing instrument according to any one of claims 1 to 5, further comprising a penetrant.   The water-based ink composition for a writing instrument according to claim 6, wherein the penetrant is one or more selected from a phosphate ester surfactant and a surfactant having an acetylene glycol bond. A writing instrument comprising the composition according to any one of claims 1 to 7.