JP2021187971A - Aqueous ink composition for writing utensil - Google Patents

Abstract

To provide an aqueous ink composition for writing utensils containing a pearl pigment which suppresses aggregation of the pearl pigment, suppresses generation of a hard cake containing the pearl pigment, is excellent in re-dispersibility of the pearl pigment settled with the lapse of time, and is excellent in temporal stability.SOLUTION: An aqueous ink composition for writing utensils contains acrylic silicone-based resin emulsion, a pearl pigment, non-association type alkali swellable (meth)acrylic emulsion, a dispersant, water, and an aqueous solvent.SELECTED DRAWING: None

Description

The present invention relates to a water-based ink composition for writing instruments that exhibits brilliance by a pearl pigment, particularly a water-based ink composition for an ink-free marking pen.

A marking pen is known as a writing instrument using a water-based ink composition. The marking pen usually includes a holder made of a hollow cylinder, an ink storage portion inside the hollow cylinder, and a porous pen tip communicating with the holder, and a water-based ink composition is transferred from the ink storage portion to a porous fiber bundle or the like. It is a writing tool that enables writing by supplying it to the pen tip, which is a quality molded body, by capillarity. Of these, a marking pen in which the ink accommodating portion is simply a hollow container inside a hollow cylinder is called an ink-free type or a direct liquid type.
In writing instruments such as marking pens, water-based ink compositions containing metal powder pigments such as aluminum pigments have been used so far in order to obtain brush marks of metallic luster colors such as gold and silver. However, the aluminum pigment reacts with water in the water-based ink composition to generate hydrogen gas, which has a problem in terms of stability over time. It is also known to use an aluminum pigment that has been water-resistant with a phosphoric acid ester or fatty acid, but the untreated aluminum surface is exposed due to crushing or bending in the dispersion process, and hydrogen gas is generated in contact with water. There was a problem left to do. Further, when the handwriting containing the aluminum pigment is exposed to water for a long time, the oxidation of aluminum progresses, and there is a possibility that the brilliance is lost and the color fades.

As a pigment to obtain a metallic glossy brush that does not react with water and does not generate hydrogen gas, flaky mineral inorganic particles such as mica, flaky metal, etc. are used as the core material. It is known to add a pearl pigment in which the surface of the core material is coated with a thin film of a metal oxide such as titanium oxide to an aqueous ink composition for writing instruments. However, since the water-based ink composition for writing instruments using the pearl pigment has a weak ink fixing property on the paper surface, it is necessary to add a fixing agent such as a water-based resin emulsion as described in Patent Document 1. Further, the specific gravity is larger than that of the aluminum pigment, and sedimentation occurs in the water-based ink composition for writing instruments, which aggregates, which causes problems in terms of dispersion stability and temporal stability.
In particular, when used in an ink-free marking pen, the pearl pigment may settle over time in the ink containing portion and aggregate to form a hard cake. When a hard cake is formed, it becomes difficult to redisperse because stirring cannot be easily achieved, and the pen tip, which is a porous molded body, is clogged, resulting in shading (color separation) in the handwriting. ) And blurring occurred, and in some cases, writing may become impossible.

Patent Document 2 describes that a cellulose derivative such as sodium carboxymethyl cellulose (CMC) is added in order to prevent aggregation and precipitation of the pearl pigment in the aqueous ink composition. However, when a cellulose derivative is used in a particularly large amount, the brilliant feeling of the pearl pigment may be lost.

Japanese Unexamined Patent Publication No. 5-117569 Japanese Unexamined Patent Publication No. 2009-46660

INDUSTRIAL APPLICABILITY In the water-based ink composition for writing instruments containing a pearl pigment, the present invention suppresses aggregation of the pearl pigment, suppresses the formation of a hard cake containing the pearl pigment, has excellent redispersibility of the pearl pigment settled over time, and has excellent aging. An object of the present invention is to provide a water-based ink composition for writing instruments having excellent stability.

As a result of diligent studies to solve the above-mentioned problems, the present inventor has found that the above-mentioned problems can be solved by the following water-based ink composition for writing instruments and a marking pen, and has completed the present invention. Specifically, it is as follows.
[1] Acrylic silicone resin emulsion,
Pearl pigment,
Non-associative alkaline swelling (meth) acrylic emulsion,
Dispersant,
Water and aqueous solvents,
A water-based ink composition for writing instruments containing.
[2] A marking pen filled with the water-based ink composition for writing instruments according to [1].
[3] An ink-free marking pen having a pen tip and an ink accommodating portion, and accommodating the water-based ink composition for writing instruments of [1] in the ink accommodating portion.

According to the present invention, in a water-based ink composition for writing instruments containing a pearl pigment, aggregation of the pearl pigment is suppressed, formation of a hard cake containing the pearl pigment is suppressed, and the redispersibility of the pearl pigment settled over time is excellent. , A water-based ink composition for writing instruments having excellent stability over time can be obtained. This water-based ink composition for writing instruments can be suitably used as a water-based ink composition for marking pens, particularly ink-free marking pens.

[Aqueous ink composition for writing instruments]
<Acrylic silicone resin emulsion>
The acrylic silicone resin emulsion contained in the water-based ink composition for writing instruments of the present invention is an emulsion of a copolymer of an acrylic compound and a silicone compound, and is used as a film-forming agent for forming a stroke.
Examples of acrylic silicone resin emulsions include CHALINE E (Nissin Kagaku Kogyo), PRIMAL PR-29, PRIMAL JP-130S (trade name manufactured by Dow Chemical Japan), Polysol AP-3900, Polysol AP-4710, etc. (Showa). Commercially available products such as Denko's product name)), AE980, AE982 (E-Tech's product name), etc. can be used.

The content of the acrylic silicone resin emulsion as the resin solid content is 10 to 80% by mass, preferably 20 to 70% by mass, and most preferably 20 to 45% by mass in the water-based ink composition for writing tools of the present invention. This makes it possible to impart excellent heat resistance and adhesiveness to the handwriting produced by the water-based ink composition for writing instruments.
If the content of the resin solid content of the resin emulsion in the water-based ink composition for writing instruments exceeds 80% by mass, the viscosity of the water-based ink composition for writing instruments becomes high, so that the outflow of ink from the writing instruments may deteriorate. .. On the other hand, if it is less than 10% by mass, the adhesiveness, water resistance and temperature water resistance of the handwriting by the water-based ink composition for writing instruments may be deteriorated.

<Pearl pigment>
The pearl pigment contained in the water-based ink composition for writing instruments of the present invention is a pigment having both mirror-like luster and pearl-like luster in addition to various color tones, in order to impart colorability and brilliance to the handwriting. Used.
As the pearl pigment, the core material is flaky inorganic particles such as mica, silica, and alumina, and the surface of the core material is one or more of metal oxides such as titanium oxide and iron oxide and metal compounds such as metal nitride. Those coated with can be used. In addition, naturally derived products produced from bismuth oxychloride, fish scales, fish skin, shellfish and the like can be used. As the pearl pigment, one or more kinds selected from these groups are used.

The pearl pigment obtained by coating a core material with a metal compound is one in which incident light is reflected multiple times by a layer of metal oxide and gloss is recognized, and the type of metal compound (metal oxide) to be coated and the type of metal oxide are recognized. By adjusting the film thickness, various color tones can be adjusted. The pearl pigment obtained by coating the core material with a metal compound is preferably used in the present invention because it is excellent in availability, safety, stability and the like. In the present invention, a surface-treated product with improved weather resistance may be used.

A wide variety of pearl pigments obtained by coating a core material with a metal compound are commercially available, and any of them can be used in the present invention. For example, commercially available pearl pigments include Iriodin, Xirallic, Color Stream and Bi-flair (above, Merck Japan), ULTIMICA and PEARL-GLAZE (Nippon Koken Kogyo), Paliocrom and Variocrom (BASF), TAYCAPEARL (Taika). Company), etc., one or more selected from the group consisting of each product number of the product name.

In the present invention, as pearl pigments, Iriodin (100, 103, 111, 151, 153, 201, 215, 217, 219, 225, 235, 289, 300, 302, 323, 502, 504, 520, 524, 530) Etc. (manufactured by Merck Japan), ULTIMICA (SB-100, SD-100, RYB-100, RYD-100, YB-100, YD-100, RB-100, RD-100, VB-100, VD-100 , GB-100, GD-100 (manufactured by Nippon Koken Kogyo Co., Ltd.), PEARL-GLAZE (MB-100R, MG-100R, MR-100R, MV-100R, MRB-100R, MY-100R, MB-100RF, Selected from the group consisting of MG-100RF, MRB-100RF, MY-100RF, MF-100, etc. (manufactured by Nippon Koken Kogyo Co., Ltd.), TAYCAPEARL (TP-500, TPX-720, etc. (manufactured by TAYCA)), etc. 1 It is preferable to use seeds or more.

The specific gravity of the pearl pigment is preferably 1 to 6, more preferably 1 to 5. Since the water-based ink composition for writing instruments of the present invention can suppress the settling of pearl pigments, even if an inorganic pigment having a large specific gravity is used, writing lines having brilliant or concealing properties can be stably drawn without color unevenness or density unevenness. be able to.
Since the pearl pigment becomes glossy due to regular multiple reflections on parallel surfaces having different refractive indexes, the gloss becomes weak when the particle size is smaller than 5 μm. Therefore, the particle size is preferably 5 μm or more. However, if the particle size is larger than 100 μm, the pen tip of a ball, a marking pen, a pen tip made of fiber such as a brush pen, or a pen tip made of a sponge-like continuous porous body may become clogged with ink and writing may not be possible. It is desirable that the particle size is 60 μm or less.
The pearl pigment may be used as it is, or may be used as a dispersion, a paste or the like dispersed in an organic solvent such as water or propylene glycol monomethyl ether.

The content of the pearl pigment is 0.5 to 15% by mass, preferably 1 to 10% by mass, based on the entire water-based ink composition for writing instruments.
If the content of the pearl pigment in the water-based ink composition for writing instruments exceeds 15% by mass, the viscosity of the water-based ink composition for writing instruments becomes high, so that the outflow of ink from the writing instruments may be deteriorated. On the other hand, if it is less than 0.5% by mass, the color development and brilliance of the handwriting may be deteriorated.

<Non-association type alkaline swelling type (meth) acrylic emulsion>
The non-associative alkaline swelling (meth) acrylic emulsion contained in the water-based ink composition for writing instruments of the present invention has excellent solubility or dispersibility in the water-based ink composition for writing instruments, and adjusts the viscosity of the ink composition. In addition, it is used to prevent the precipitation of pigment components, especially pearl pigments, and to suppress the generation of hard cakes.

The non-associative alkaline swelling (meth) acrylic emulsion used in the present invention is different from the acrylic silicone resin emulsion and contains (meth) acrylic acid and (meth) acrylic acid ester as monomer components. It is an emulsion of a copolymer (ASE (Alkali-Soluble Emulsion) type).
The non-associative alkaline swelling (meth) acrylic emulsion is a low-viscosity liquid in the acidic region, and when it is neutralized with a base, it expands and the molecules are entangled with each other and spread over the entire dispersion medium. , Exhibits viscosity adjustment function (viscosity thickening action).
Examples of the base include ammonia (water), amines (for example, mono, di or triethanolamine, dimethylethanolamine, N-methylethanolamine, N-methyldiethanolamine, diisopropanolamine, etc.), and inorganic bases (sodium hydroxide, water). Potassium oxide, etc.). The water-based ink composition for writing tools containing a non-associative alkaline swelling (meth) acrylic emulsion preferably has a pH value of more than 7, preferably 8 or more, and is preferably swelled and stabilized. Considering the stability of other components such as colorants, the pH value is preferably 10 or less.

The non-associative alkaline swelling type (meth) acrylic emulsion can impart a thixotropic behavior to a water-based ink composition for writing instruments, and becomes highly viscous in a stationary state, and a hard cake of a pigment or the like settled or settled. When a shearing force is applied to the water-based ink composition for writing instruments by shaking the writing instrument before writing, the viscosity decreases and the ink outflow property is satisfied. It returns to the initial high viscosity state and can suppress liquid dripping and the like.

The non-associative alkaline swelling (meth) acrylic emulsion of the present invention is an associative alkaline swelling (meth) acrylic emulsion containing a copolymer having an associative hydrophobic group (HASE (Hydrophobically modified Alkali-Soluble Emulsion) type). It is different from an emulsion. Examples of the associative hydrophobic group include a chain-like or cyclic hydrocarbon group, an aromatic hydrocarbon group, an alkyl halide group, an organosilicon group, a fluorocarbon group and the like, and have a co-weight having an associative hydrophobic group. Hydrophobic chain transfer agents (eg, dodecyl mercaptan), hydrophobic monomers (eg, decyl methacrylate, nonionic vinyl monomers), hydrophobic group-containing alcohols (eg, dodecanol), nonionic surfactants in obtaining coalescence. Etc. are introduced (modified) into the copolymer.

A wide variety of non-associative alkaline swelling (meth) acrylic emulsions are commercially available, and any of them can be used in the present invention. For example, as a commercially available non-associative alkaline swelling (meth) acrylic emulsion, one selected from the group consisting of appropriate product numbers under trade names such as PRIMAL (Dow Chemical Japan) and Rheovis (BASF). The above can be mentioned.

In the present invention, as a non-associative alkaline swelling (meth) acrylic emulsion, for example, PRIMAL (ASE-60, ASE-75, ASE-95NP, ASE-108NP, ASE-1000, G-111, etc. From Chemical Japan), Rheovis (AS 1125 (Latekoll D), AS 1130 (Viscalex HV 30), AS 1237 (Viscalex VM), AS 1337 (Viscalex VG 2), AS 1956, etc. (BASF)) It is preferable to use one or more selected from the group.

The content of the non-associative alkaline swelling (meth) acrylic emulsion is 0.01 to 5% by mass, preferably 0.02 to 3% by mass, more preferably 0.02 to 3% by mass in the water-based ink composition for writing utensils, as the resin solid content thereof. Is 0.03 to 1% by mass. As a result, the viscosity of the water-based ink composition for writing instruments can be set in an appropriate range, and the generation of hard cake can be suppressed even when sedimentation occurs in the ink composition.
When the content of the non-associative alkaline swelling (meth) acrylic emulsion in the water-based ink composition for writing instruments exceeds 5% by mass as the resin solid content, the viscosity of the water-based ink composition for writing instruments becomes high. There is a risk that the outflow of ink from the writing instrument will worsen. On the other hand, if it is less than 0.01% by mass, the pigment settled in the ink composition, particularly the pearl pigment, forms a hard cake, which may worsen the outflow of the ink and reduce the brilliance of the handwriting. There is.

<Dispersant>
The dispersant contained in the water-based ink composition for writing instruments of the present invention has an effect of stabilizing the dispersion of pearl pigments, colorants and the like and preventing the precipitation of pigments, and itself has good dispersibility in water. It is a thing. The dispersant may function as a vehicle / fixing agent for forming a coating film of a water-based ink composition for writing instruments.
The dispersant is not particularly limited as long as it is used for a water-based ink composition for writing instruments, particularly a water-based ink composition for marking pens, and commercially available ones can be used. For example, a water-soluble resin, a resin emulsion, a surfactant, or the like can be used.

Examples of the water-soluble resin include water-soluble (meth) acrylic resin, water-soluble maleic acid-based resin, water-soluble styrene- (meth) acrylic resin, water-soluble styrene-maleic acid-based resin, polyvinylpyrrolidone-based resin, and polyvinyl. One or more selected from the group consisting of alcohol-based resins, water-soluble urethane-based resins, cellulose-based resins such as sodium carboxymethyl cellulose and the like can be mentioned. The resin emulsion is other than the acrylic silicone resin emulsion, and further is other than the non-associative alkali swelling type (meth) acrylic emulsion, for example, a (meth) acrylic acid ester emulsion or a vinyl acetate emulsion. One or more selected from the group consisting of emulsions, urethane-based emulsions and the like can be mentioned. Examples of the surfactant include anionic, cationic, nonionic and amphoteric surfactants, and examples thereof include anionic surfactants such as alkylbenzene sulfonic acid (salt), alkyl sulfosuccinic acid and alkyl phenyl phosphate ester. Examples thereof include nonionic surfactants such as activators, polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters, polyoxyalkylene alkyl aryl ethers, sorbitan esters, and alkyl phosphate esters.
In the present invention, among these dispersants, nonionic surfactants having a wetting / penetrating function, an emulsifying function and a dispersing function, particularly a polyoxyalkylene alkyl ether (for example, Naroacty (trade name manufactured by Sanyo Chemical Industries, Ltd.)). )) Is preferably used.

The content of the dispersant is 0.1 to 10% by mass, preferably 0.5 to 5% by mass in the water-based ink composition for writing instruments. If the content of the dispersant in the water-based ink composition for writing instruments exceeds 10% by mass, the fixability of the handwriting may deteriorate. On the other hand, if it is less than 0.1% by mass, the dispersion of the pigment becomes poor and coarse particles remain, which may lead to poor ink outflow.

<Water>
The water-based ink composition for writing instruments of the present invention contains water that functions as a dispersion medium and / or a solvent for dispersing and / or dissolving the constituent components. As the water, for example, tap water, purified water, distilled water, ion-exchanged water, and pure water are used. Preferably, ion-exchanged water, distilled water and the like are used.
The water content can be appropriately adjusted according to the content, viscosity, etc. of each component in the water-based ink composition for writing instruments. For example, it can be 5 to 90% by mass, preferably 10 to 80% by mass, and more preferably 10 to 70% by mass in the water-based ink composition for writing instruments. If the water content is less than 5% by mass, there is a risk of blurring during writing and deterioration of storage stability. If it exceeds 90% by mass, a sufficient color development effect may not be obtained (color is light).

<Aqueous solvent>
The aqueous solvent which may be contained in the aqueous ink composition for writing tools of the present invention can be used without particular limitation as long as it is an aqueous solvent having good solubility in water. An aqueous solvent derived from the above-mentioned acrylic silicone resin emulsion is also included. The aqueous solvent can also be used as a viscosity modifier, a desiccant or a wetting agent for an aqueous ink composition for writing instruments.
The aqueous solvent is not particularly limited, but glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and polyethylene glycol, polyhydric alcohols such as glycerin and trimethylolpropane, and ethylene. One or more selected from the group consisting of glycol ethers such as glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monopropyl ether can be mentioned.

The content of the aqueous solvent is, for example, 0 to 20% by mass, preferably 0.1 to 20% by mass, and most preferably 1 to 10% by mass in the water-based ink composition for writing instruments. If the content of the water-based solvent exceeds 20% by mass, the drying speed of the water-based ink composition for writing instruments becomes slow, and the handwriting may become sticky. On the other hand, if it is less than 0.1% by mass, the water-based ink composition for writing instruments tends to dry with the pen tip, and the ink may not easily come out.

<Colorant>
The water-based ink composition for writing instruments of the present invention may contain a colorant other than the pearl pigment in order to obtain a handwriting of a desired color tone. For example, one or more selected from the group consisting of inorganic pigments, organic pigments, colored resin balls, dyes and the like exhibiting arbitrary color tones can be used.
The colorant has properties such as good writing property without blurring, good drying property and cap-off property, good sedimentation stability of components in ink, and excellent storage stability. If so, it can be used without particular limitation.

Examples of the inorganic pigment include carbon black, titanium oxide, zinc oxide, red iron oxide, yellow iron oxide, ultramarine, dark blue, metal powder such as aluminum powder and bronze powder, fluorescent pigment, glass flakes, and brilliant pigment. One or more selected from the group can be used.
Examples of the organic pigment include known coloring pigments such as phthalocyanine, azo, quinacridone, anthracinone, dioxane, indigo, thioindigo, perinone, perylene, indolinone, and azomethine, and fluorescent pigments. One or more species selected from the group can be used.
As the colored resin sphere, a spherical, amorphous, hollow, flat or the like resin sphere is colored with one or more of an inorganic pigment, an organic pigment or a dye exhibiting an arbitrary color tone. Examples of the resin material forming the colored resin sphere include polyethylene, polypropylene, vinyl chloride, polymethacrylate, benzoguanamine, melamine resin, nylon and the like.
As the dye, a water-soluble dye is preferable, and any of a direct dye, an acid dye, an edible dye, and a basic dye can be used. For example, one or more selected from the group consisting of colored dyes and fluorescent dyes such as anthraquinone-based, methine-based, carbonium-based, and metal complex salt-based dyes can be used.

When the water-based ink composition for writing instruments of the present invention contains a colorant, it may be appropriately adjusted so as to have a desired color tone. For example, it can be contained in an amount of 0 to 35% by mass, preferably 0.1 to 35% by mass, preferably 1 to 30% by mass, based on the total amount of the water-based ink composition for writing instruments. If the content of the colorant exceeds 35% by mass, the solid content increases, which may adversely affect the fluidity, viscosity, handleability, sedimentation stability, handwriting blurring, manufacturing cost, and the like. Further, if it is less than 0.1% by mass, color development may be deteriorated depending on the contained pearl pigment.

<Other additives>
The water-based ink composition for writing instruments of the present invention may contain other additives, if necessary. The other additives are not particularly limited as long as they are used in the water-based ink composition for marking pens. Lubricants, antiseptic and antifungal agents, defoaming agents, leveling agents, UV absorbers, infrared absorbers, antioxidants, non-heat discoloring pigments, non-heat discoloring dyes, optical brighteners, non-fluorescent whitening agents, as needed One or more selected from the group consisting of viscosity regulators (thickeners), wetting agents, pH regulators, etc. other than the association type alkali swelling type (meth) acrylic emulsion can be used in an appropriate amount.
For example, as an antiseptic / antifungal agent, a benzoisothiazolin-based antiseptic / antifungal agent, a pentachlorophenol-based antiseptic / antifungal agent, a cresol-based antiseptic / antifungal agent, a propylene glycol-based antiseptic / antifungal agent, an iodine-based antiseptic / antifungal agent, etc. should be used. Can be done.

<Viscosity>
The viscosity of the water-based ink composition for writing instruments of the present invention may be appropriately set, for example, 1 to 100,000 mPa · s, preferably 100 to 20,000 mPa · s, and more preferably 1,000 to 10,000 mPa · s. It can be in the range of (E-type rotational viscometer (for example, TVE-type viscometer manufactured by Toki Sangyo Co., Ltd., 3 ° R14 cone, 0.5 rpm)). If the viscosity of the water-based ink composition for writing instruments is less than 1 mPa · s, the ink may flow out excessively from the tip of the writing instrument and it may not be possible to form handwriting accurately, and in terms of sedimentation stability of pearl pigments and the like. It can be a problem. If the viscosity exceeds 100,000 mPa · s, the viscosity may become too high and the ink may not flow out from the tip of the writing instrument, and in terms of ink handling, sedimentation stability, handwriting blurring, manufacturing cost, etc. It can be a problem.

<Manufacturing method of water-based ink composition for writing instruments>
The method for producing a water-based ink composition of the present invention is not particularly limited, and any known method for producing a water-based ink composition can be used.
For example, by putting all the above-mentioned components into a container, mixing and stirring with a device such as a ball mill, a bead mill, a roll mill, a henschel mixer, a homomixer, a propeller stirrer, a homogenizer, a high-pressure homogenizer, a kneader, and a dissolver to disperse the components. , Ink can be made.

For example, a dispersion was produced by putting some components of a water-based ink composition for writing instruments, for example, water, a pearl pigment, an acrylic silicone resin emulsion, etc. into a container, mixing and stirring with the above apparatus, and dispersing the ink. Later, the remaining components can be added, mixed and stirred to prepare a water-based ink composition for writing instruments.
In producing the water-based ink composition for writing instruments, coarse particles, gas, and bubbles may be removed by performing operations such as filtration, centrifugation, and defoaming. Means such as heating, cooling, pressurization, depressurization, and substitution with an inert gas can also be adopted when producing the water-based ink composition for writing instruments. Further, an aging step may be performed after preparing the water-based ink composition for writing instruments.

[Marking pen]
The marking pen of the present invention includes a pen tip made of a fiber core or a plastic core and an ink accommodating portion, and the water-based ink composition is accommodated in the ink accommodating portion.

In the present invention, it is particularly preferable to use an ink-free marking pen. The ink-free marking pen includes, for example, an ink accommodating portion, a stirrer provided in the ink accommodating portion, a valve, a pen tip, a shaft body, and a cap. In the ink-free marking pen, the void inside the shaft body serves as an ink accommodating portion, and the water-based ink composition for writing instruments is accommodated in this ink accommodating portion. In addition to the shaft body, a cylindrical center pole may be provided inside the shaft body, and the gap inside the center pole may be used as an ink accommodating portion. The ink container and the pen tip are connected via a valve, and the water-based ink composition in the ink container is supplied to the pen tip via the valve.

In the present invention, the materials and shapes constituting the ink accommodating portion, stirrer, valve, pen tip, shaft body and cap included in the marking pen are not particularly limited, and general ones are appropriately used.
The pen tip is formed of a fiber core or a plastic core capable of supplying a water-based ink composition for writing instruments. When a fiber core is used, the pore ratio of the fiber core, the thread diameter of the fiber, the amount of impregnation of the water-based ink composition into the core, etc. should be adjusted according to the particle size of the inorganic pigment in order to facilitate the discharge of the inorganic pigment. Is preferable. In particular, when a large particle size inorganic pigment having an average particle size of 1 μm or more is used as the inorganic pigment, it is preferable that the pore ratio of the fiber core is 50 to 85%, and the thread diameter of the fiber used is 10 to 50 d (denier). ) Is preferable. Similarly, when a plastic core is used, it is preferable to adjust the ink flow path width according to the particle size of the inorganic pigment. In the marking pen, the shape of the tip of the pen tip is not particularly limited, and may be a chisel shape, a bullet shape, a brush pen shape, or the like. For example, in the case of a chisel shape having an inclined surface inclined with respect to the center line of the shaft body, a writing line can be drawn by contacting the inclined surface of the pen tip with the paper surface. At this time, the length of the inclined surface in the longitudinal direction is the line width of the writing line. The length of the inclined surface in the longitudinal direction is preferably 2 mm or more, and more preferably 2 to 5 mm from the viewpoint of ease of marking.

The marking pen of the present invention is provided with a stirrer such as a ball in the ink accommodating portion in order to surely form a brilliant handwriting, and the ink is agitated by shaking the main body immediately before writing. Since the water-based ink composition for writing instruments of the present invention has a sufficiently high effect of suppressing sedimentation of the pearl pigment and preventing the formation of a hard cake, the redispersibility of the pearl pigment is good by stirring the ink immediately before writing. Further, since a good dispersed state can be maintained, suitable writing performance without color unevenness or density unevenness can be obtained. In the present invention, it is also possible to use an ink-free marking pen that does not have a stirrer in the ink accommodating portion.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "part" means parts by mass.

[Components of Aqueous Ink Composition for Writing Instruments]
The following components were prepared as constituents of the water-based ink composition for writing instruments.
<Acrylic silicone resin emulsion>
・ PRIMAL PR-29 (Acrylic silicone resin emulsion (Dow Chemical Japan, trade name (solid content 43% by mass)))
<Dispersant>
-Polyoxyethylene alkyl ether (Naroacty CL-70 (trade name manufactured by Sanyo Chemical Industries, Ltd.))
<Pearl pigment>
-IRIODIN 123: Mica coated with titanium oxide and tin oxide (trade name manufactured by MERCK)
-IRIODIN 325: Mica coated with titanium oxide, silicon oxide, iron oxide and tin oxide (trade name manufactured by MERCK)
・ IRIODIN 522: Mica coated with iron oxide (trade name manufactured by MERCK)

<Colorant>
-Carbon black dispersion Monarch 800 (carbon black: trade name manufactured by Cabot) 17.0% by mass, ion-exchanged water 67.0% by mass, styrene-acrylic resin 30% by mass aqueous solution 11.3% by mass, ethylene glycol (MONO) Ethylene Glycol) 4.1% by mass, organic iodine-based antifungal agent 0.3% by mass, and benzoisothiazolin-based preservative 0.3% by mass were uniformly stirred and mixed, and dispersed using a medium. Carbon black dispersion.
・ PIGMENT BLUE 15: 1 dispersion
PV FAST BLUE A4R (PIGMENT BLUE 15: 1 (blue pigment): CLARIANT brand name) 17.0% by mass, ion-exchanged water 69.6% by mass, styrene-acrylic resin 34% by mass aqueous solution 10.0% by mass, PIGMENT obtained by uniformly stirring and mixing 2.6% by mass of propylene glycol, 0.5% by mass of an organic iodine-based antifungal agent, and 0.3% by mass of a benzoisothiazolin-based preservative, and dispersing them using a medium. BLUE 15: 1 dispersion.

<Viscosity adjuster>
・ ASE-60 25% aqueous dispersion:
PRIMAL ASE-60 (Non-associative alkaline swelling acrylic resin emulsion (trade name manufactured by Dow Chemical Japan Co., Ltd. (solid content 28% by mass)) 25% by mass, ion-exchanged water 61.9% by mass, 10% by mass hydroxylation An aqueous dispersion containing 12.5% by mass of an aqueous sodium solution, 0.3% by mass of an organic iodine-based antifungal agent, and 0.3% by mass of a benzoisothiazolin-based preservative.
・ TT-615 6.6% aqueous dispersion:
PRIMAL TT-615 (Alkaline association type acrylic resin emulsion (trade name manufactured by Dow Chemical Japan Co., Ltd. (solid content 30% by mass)) 6.6% by mass, ion-exchanged water 92.1% by mass, 28% by mass ammonia water 0 An aqueous dispersion containing 0.7% by mass, an organic iodine-based antifungal agent, 0.3% by mass, and a benzoisothiazolin-based preservative, 0.3% by mass.
・ TT-935 8.3% aqueous dispersion:
PRIMAL TT-935 (Alkaline-associated acrylic resin emulsion (trade name manufactured by Dow Chemical Japan Co., Ltd. (solid content 30% by mass)) 8.3% by mass, ion-exchanged water 89.4% by mass, 28% by mass ammonia water 1 An aqueous dispersion containing 0.7% by mass, an organic iodine-based antifungal agent, 0.3% by mass, and a benzoisothiazolin-based preservative, 0.3% by mass.
・ RM-12W:
PRIMAL RM-12W (Alkaline-associated urethane resin emulsion (Dow Chemical Japan, trade name (solid content 19% by mass))
・ SN thickener
SN Thickener 612 (Alkaline-associated urethane resin emulsion (trade name manufactured by San Nopco Ltd. (solid content 40% by mass)))
<Preservative>
・ Proxel XL-2: (Benzisothiazolin-3-one solution: product name manufactured by Lonza Japan)
<Antifungal agent>
・ Coatside PH2: (Organoiodine compound: Product name manufactured by Osaka Gas Chemical Co., Ltd.)
<Lubricant>
・ Ethylene glycol ・ Diethylene glycol <Antifoaming agent>
・ FS Antifoam 1277: (Product name manufactured by Toray Dow Corning)
<Surface tension adjuster>
Neocol YSK: Dialkylsulfosuccinate salt (trade name (70% by mass) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
<Leveling agent>
-BYK 348: Polyether-modified polydimethylsiloxane (trade name manufactured by BYK)

[Examples 1 to 7, Comparative Examples 1 to 4]
Using the above components in the amounts (parts by mass) shown in Table 1, a water-based ink composition for writing instruments was prepared by the following method.
Further, a marking pen was produced by the following method using the obtained water-based ink composition for writing instruments.

<Method of producing water-based ink composition for writing instruments>
After mixing the acrylic silicone resin emulsion (PRIMAL PR-29) with water, the dispersant (Naroacty CL-70) was added and stirred.
A pearl pigment was added to the obtained mixed liquid and stirred, and then the remaining components were added and stirred to obtain a water-based ink composition for writing instruments.

<How to make a marking pen>
The obtained water-based ink composition for writing instruments is filled in a pen body containing a stirrer, covered with a plastic valve, a fiber bundle tip with a urethane ring is attached as a pen tip, and a lower cap is attached. After tightening the screws, the upper cap was put on to make an ink-free marking pen.
The obtained ink-free marking pen is stored at 50 ° C. in an upright state with the pen tip up for one month, and then the pen is shaken to check the number of times until the stirrer moves. The evaluation of the thing was done as follows. The results are also shown in Table 1.
◯: The stirrer moves within 5 shakes △: The stirrer moves with 6 or more and 20 or less shakes ×: The stirrer does not move or the stirrer does not move at all unless it is 21 or more.

As is clear from the results of each Example / Comparative Example, by using a non-associative alkaline swelling (meth) acrylic emulsion as a viscosity modifier, the pearl pigment is redispersed even after storage for a certain period of time. It can be seen that a water-based ink composition for writing instruments having excellent properties can be obtained.

Claims (3)

Acrylic silicone resin emulsion,
Pearl pigment,
Non-associative alkaline swelling (meth) acrylic emulsion,
Dispersant,
Water and aqueous solvents,
A water-based ink composition for writing instruments containing. A marking pen filled with the water-based ink composition for writing instruments according to claim 1. Equipped with a pen tip and ink storage
An ink-free marking pen in which the water-based ink composition for writing instruments according to claim 1 is contained in the ink accommodating portion.