JP6921901B2 - Aqueous ink composition for writing tools and writing tools using it - Google Patents

Description

The present invention relates to a water-based ink composition for writing tools and a writing tool using the same.

Conventionally, as a water-based ink composition for writing instruments capable of leaving a writing line having brilliance, an ink composition containing a metal powder such as aluminum, a gelling agent, and spherical resin particles is known (see, for example, Patent Document 1). ).

In addition, as a similar water-based ink composition for writing utensils, Patent Document 2 discloses an ink composition containing a metal pigment coated with water, a water-soluble solvent and a silicate, and Patent Document 3 discloses a metal. Ink compositions containing powder pigments, colorants, water, water-soluble organic solvents, natural polysaccharides and cellulose derivatives are disclosed.

However, the writing line formed by using the conventional ink composition as described above has low friction resistance, and there is a possibility that the writing line may be peeled off due to friction, and there is room for improvement. From this point of view, Patent Document 4 proposes an ink composition containing an acrylic acid ester in order to improve the adhesiveness of the writing line, and the writing formed by using this ink composition. Even if it was a wire, it could not be said that the abrasion resistance was sufficient.

Japanese Unexamined Patent Publication No. 2010-126715 Japanese Unexamined Patent Publication No. 2014-231553 Japanese Patent No. 3774546 Japanese Unexamined Patent Publication No. 2013-124360

The present inventor has recently added a specific component to a water-based ink composition containing glittering pigment particles, so that the writing line formed by a marker or the like using the water-based ink composition has a high smoothness. It was found that the property can be imparted, and as a result, the scratch resistance of the writing line can also be improved.

The present invention is based on such findings, and an object of the present invention is to provide a water-based ink composition for writing instruments capable of forming high slipperiness and abrasion resistance on a writing line.

The water-based ink composition for writing instruments according to the present invention comprises bright pigment particles, polyolefin resin particles, and a solvent, and has a viscosity index n at 20 ° C. of 0.7 to 1.0. Is to be.

Further, the writing tool according to the present invention is characterized in that it contains the above-mentioned water-based ink composition for writing tools.

According to the present invention, it is possible to impart high slipperiness to a writing line formed by using the water-based ink composition, and it is possible to realize a writing line having high abrasion resistance.

In the present specification, "part", "%", "ratio" and the like indicating the composition are based on mass unless otherwise specified.

(Aqueous ink composition for writing tools)
The water-based ink composition for writing instruments according to the present invention (hereinafter, sometimes referred to as "water-based ink composition") comprises bright pigment particles, polyolefin resin particles, and a solvent.

The viscosity index n of the water-based ink composition according to the present invention at 20 ° C. is 0.7 to 1.0. Here, the viscosity index n refers to n in the viscosity formula ^{represented by S = αD n.} S is the shear stress (dyn / cm ² = 0.1 Pa), D is the shear rate (s ^-1 ), and α is the viscosity coefficient. The viscosity index n can be calculated by measuring the ink viscosity using an E-type rotational viscometer (DV-II + Pro, cone-type rotor CPE-42, manufactured by Brookfield). The viscosity index n of the water-based ink composition is more preferably 0.80 to 1.00, still more preferably 0.85 to 0.98. When the viscosity index n of the water-based ink composition is within the above numerical range, the ink ejection property when used for a writing instrument such as a marker can be improved, and in particular, the writing property on a non-penetrating recording medium such as a film can be improved. Can be improved.

The viscosity of the aqueous ink composition at 20 ° C., a shear rate of 380 sec ^-1 , and a rotation speed of 100 rpm is preferably 1 to 50 mPa · s, and more preferably 3 to 30 mPa · s. When the viscosity of the water-based ink composition is within the above numerical range, the ink ejection property when used for a writing instrument such as a marker can be improved. In particular, considering the improvement of writeability for a non-permeable recording medium such as a film, 5 to 15 mPa · s is more preferable. The viscosity can be measured using an E-type rotational viscometer (manufactured by Brookfield).

The pH of the aqueous ink composition is preferably 6.0 to 10.0, more preferably 7.0 to 9.0. If the pH of the water-based ink composition is within the above numerical range, the metal pigment particles may corrode or the dispersibility may decrease even if the glitter pigment particles are metal pigment particles. Can be prevented. In the present invention, the pH value can be measured at 20 ° C. by, for example, an IM-40S type pH meter (manufactured by DKK-TOA CORPORATION).

(Glittering pigment particles)
As the glittering pigment particles, metal pigment particles are generally used. The material of the metal pigment particles is not particularly limited, and examples thereof include aluminum, brass, stainless steel, bronze, titanium oxide, iron oxide, aluminum oxide, and alloys thereof. Among these, aluminum is preferable because it has a small specific gravity and can prevent the precipitation of bright pigment particles and the accompanying deterioration of hard cake formation and redispersibility. The particles are not limited to metal pigment particles, and inorganic materials such as mica and pearl mica can also be used.

The shape of the pigment particles can be arbitrarily selected, but is preferably needle-shaped, plate-shaped or square because it can more diffuse light and improve the brilliance.

The glittering pigment particles are preferably the metal pigment particles coated with a coating material such as silica, phosphate, molybdenum, or silicate. By coating the metal pigment particles with a coating material such as silica, it is possible to prevent the glitter pigment particles in the aqueous ink composition from settling over time and forming a hard cake. Among the above coatings, silica coating is preferable from the viewpoint of low reactivity with a solvent and high stability, and phosphate coating and molybdenum coating are preferable from the viewpoint of cost reduction.

The amount of the metal pigment particles coated with silica or the like, that is, the ratio of the mass of the coating material such as silica to 100 parts by mass of the metal pigment particles is preferably 3 to 20 parts by mass, and is preferably 11 to 20 parts by mass. Is more preferable. When the coating amount is within the above numerical range, it is possible to sufficiently prevent the water-based ink composition from forming a hard cake without impairing the brilliance of the metal pigment particles.

The average particle size of the bright pigment particles is preferably 1 μm to 30 μm, more preferably 3 μm to 20 μm, and even more preferably 3 μm to 10 μm. When the average particle size of the glittering pigment particles is within the above numerical range, the glittering property of the water-based ink composition and the writing line formed by using the water-based ink composition can be maintained, and the glittering pigment particles are the water-based ink. Even when it is precipitated in the composition, its redispersibility can be improved. Further, when an aqueous ink composition containing bright pigment particles having an average particle size within the above numerical range is used for a writing instrument such as a marker, the ink ejection property can be improved. The average particle size of the bright pigment particles is measured by a laser diffraction method using a laser diffraction type particle size distribution measuring machine (trade name "Microtrac HRA9320-X100", Nikkiso Co., Ltd.) when the cumulative volume of the particle size distribution is 50%. It can be measured by the particle size (D50) of. In the present specification, the "average particle size" of the bright pigment particles refers to the volume-based average particle size unless otherwise specified.

When the average particle size of the bright pigment particles is D μm and the average thickness is d μm, the aspect ratio (D / d) of the bright pigment particles is preferably 1 to 100, preferably 10 to 50. More preferred. This is because when the aspect ratio (D / d) of the brilliant pigment particles is within the above numerical range, the metal pigment particles are given high brilliance and it is easy to suppress ink clogging at the pen tip.

The content of the bright pigment particles in the water-based ink composition is preferably 1 to 15% by mass, more preferably 2 to 8% by mass, based on the total mass of the water-based ink composition. When the content of the brilliant pigment particles is within the above numerical range, deterioration of the ink ejection property can be prevented, and the brilliance of the water-based ink composition and the writing line formed by using the water-based ink composition is maintained. be able to.

(Polyolefin resin particles)
Examples of the material of the polyolefin resin particles include polyolefins such as polyethylene and polypropylene, and mixtures thereof. When polyethylene is used, low-density polyethylene, linear low-molecular-weight polyethylene, high-density polyethylene, modified polyethylene, modified high-density polyethylene and the like can be used. The molecular weight of these polyolefins is not particularly limited, but for example, polyolefins having a weight average molecular weight of 500 to 10000 are preferable, and polyolefins having a weight average molecular weight of 3000 to 8000 are more preferable. When the weight average molecular weight of the polyolefin resin particles is within the above numerical range, the water-based ink composition has higher slipperiness with respect to the writing line formed when writing is performed using a writing instrument such as a marker. Along with this, high abrasion resistance can be imparted. The polyolefin resin particles may contain a material other than polyolefin, if necessary.

The shape of the polyolefin resin particles is not particularly limited and can take any shape such as spherical, needle-shaped, plate-shaped, and square, but the spherical shape tends to reduce the frictional resistance. Since it is easy to impart high slipperiness to the writing line, it is preferably spherical.

The average particle size of the polyolefin resin particles is preferably 0.1 μm to 35 μm. When the average particle size of the polyolefin resin particles is within the above numerical range, the water-based ink composition has higher slipperiness with respect to the writing line formed when writing is performed using a writing instrument such as a marker. Along with this, high abrasion resistance can be imparted. Further, from the viewpoint of maintaining the brilliance of the water-based ink composition and its writing line while imparting high abrasion resistance, it is more preferably 0.1 to 20 μm, and 0.5 μm to 10 μm. It is more preferable, and it is particularly preferable that it is 0.5 μm to 5 μm. The average particle size of the polyolefin resin particles can be measured by the Coulter counter method.

The content of the polyolefin resin particles in the water-based ink composition is preferably 0.01 to 10% by mass, more preferably 0.1 to 2% by mass, based on the total mass of the water-based ink composition. , 0.1 to 1.5% by mass, more preferably. When the content of the polyolefin resin particles is within the above numerical range, the ink ejection property and the water-based ink composition, and the brilliance of the writing line formed by using the ink composition can be maintained, and the writing line can be maintained with respect to the writing line. Higher slipperiness can be imparted.

The compounding ratio of the polyolefin resin particles to the bright pigment particles is preferably 0.01 to 1.0 times, more preferably 0.05 to 0.5 times, based on the mass. When the compounding ratio is within the above numerical range, the brilliance of the water-based ink composition and the writing line formed by using the water-based ink composition can be maintained, and the writing line can be imparted with even higher slipperiness. Can be done.

(solvent)
Examples of the solvent include water and a mixed solvent of water and an organic solvent. As the 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, propanol, isopropyl alcohol, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, mineral spirit and the like can be used as the organic solvent. can. The content of the organic solvent is preferably 30% by mass or less, more preferably 20% by mass or less, based on the total mass of the solvent.

The content of the solvent in the water-based ink composition is preferably 20 to 90% by mass, more preferably 30 to 80% by mass, based on the total mass of the water-based ink composition. When the content of the solvent is within the above numerical range, the stability of the water-based ink composition can be maintained and good writing performance can be obtained.

(Agglutination control agent)
The water-based ink composition preferably contains an agglutination control agent. The coagulation control agent can prevent the water-based ink composition from forming a hard cake and improve the redispersibility. As the aggregation control agent, for example, an elastic polymer, a cellulose derivative, or the like can be used, and it is particularly preferable to use two or more of these in combination.

(Elastic polymer)
By including the elastic polymer in the water-based ink composition, the redispersibility of the water-based ink composition can be improved. In addition, the elastic polymer can improve the fixability of the water-based ink composition, and can further improve the scratch resistance of the writing line formed by using the elastic polymer.

In the present invention, the elastic polymer means a polymer having elasticity in a solid state. Examples of such polymers include styrene-olefin elastomers, olefin elastomers, acrylic elastomers, and styrene-acrylics, which are composed of styrene and olefins such as butadiene, isoprene, ethylene / butylene, ethylene / propylene, and vinylisoprene. Elastomers such as elastomers, urethane elastomers, polyester elastomers, polyamide elastomers, vinyl acetate elastomers, vinyl chloride elastomers, fluoroelastomers, synthetic rubbers such as natural rubber and silicon rubber, and ethylene resins such as ionomer resins. Examples include resin. Of these, styrene-butadiene elastomers and acrylic elastomers are preferably used. It is more preferable to use a styrene-butadiene elastomer because it is possible to impart an effect of easily suppressing the cracking of the writing line (bending strength) even if the writing line has elasticity and the writing recording medium is bent. The molecular weight of the elastic polymer is not particularly limited, and for example, a weight average molecular weight of 1,000 or more is preferable depending on the physical properties of the target water-based ink composition. On the other hand, those having a weight average molecular weight of 1,000,000 or less can be used.

The glass transition temperature (Tg) of the elastic polymer is preferably 1 to 70 ° C, more preferably 2 to 60 ° C, and further preferably 2 to 20 ° C. When the glass transition temperature of the elastic polymer is within the above numerical range, the brilliance of the water-based ink composition and the writing line formed by using the aqueous ink composition and the abrasion resistance of the writing line can be improved. The Tg of the elastic polymer can be determined by differential scanning calorimetry.

The content of the elastic polymer in the water-based ink composition is preferably 0.1 to 10.0% by mass, preferably 0.1 to 5.0% by mass, based on the total mass of the water-based ink composition. Is more preferable.

(Cellulose derivative)
Examples of the cellulose derivative include carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl ethyl cellulose and salts thereof. Of these, carboxymethyl cellulose is preferable because it can prevent the bright pigment particles from forming a hard cake and reducing the redispersibility. It is considered that this is because the carboxyl group contained in carboxymethyl cellulose is easily adsorbed on the bright pigment particles and inhibits the aggregation of the bright pigment particles. Further, carboxymethyl cellulose is preferable because it has good solubility in an aqueous ink composition.

The content of the cellulose derivative in the water-based ink composition is preferably 0.1 to 10.0% by mass, preferably 0.5 to 5.0% by mass, based on the total mass of the water-based ink composition. Is more preferable.

(Water-soluble acrylic polymer)
The water-based ink composition preferably contains a water-soluble acrylic polymer. In the present invention, the water-soluble acrylic polymer contains acrylic acid or methacrylic acid as a repeating unit and has a water-soluble group in the side chain. The water-soluble group may be a carboxyl group derived from acrylic acid or methacrylic acid, or may be another water-soluble group. By including the water-soluble acrylic polymer in the water-based ink composition, the fixability of the water-based ink composition can be improved, and the scratch resistance of the writing line formed by using the water-soluble ink composition can be further improved. Further, it is preferable that the water-soluble acrylic polymer has a carboxyl group. This is because such a water-soluble acrylic polymer is adsorbed on the bright pigment particles and inhibits the aggregation of the bright pigment particles, so that it is possible to prevent their hard cake formation and deterioration of redispersibility. In particular, it is preferable to use the above-mentioned aggregation control agent in combination with a water-soluble acrylic polymer because the effect is strongly exhibited.

As the water-soluble acrylic polymer, a water-soluble acrylic resin, a water-soluble styrene-acrylic resin, or the like can be used. The molecular weight of these polymers is not particularly limited, but for example, those having a weight average molecular weight of 1000 to 100,000 are preferable.

The content of the water-soluble acrylic polymer in the water-based ink composition is preferably 0.1 to 7% by mass, more preferably 0.3 to 5% by mass, based on the total mass of the water-based ink composition. preferable.

(Surfactant with acetylene bond)
The water-based ink composition preferably contains a surfactant having an acetylene bond. By including such a surfactant in the water-based ink composition, the surface tension is lowered, the wettability of the water-based ink composition with respect to a non-permeable recording medium such as a film is improved, and the water-based ink composition is subjected to the non-penetrating recording medium. Writability can be improved. Among the surfactants, the surfactant having an acetylene bond has extremely high stability and can continuously exert the effect of improving the wettability.

Examples of the above-mentioned surfactant include acetylene alcohol-based surfactants and acetylene glycol-based surfactants. In particular, an acetylene glycol- based surfactant is preferable because it is excellent in volatility of the writing line after writing, that is, drying property, and can impart abrasion resistance in a short time.

The content of the surfactant having an acetylene bond in the water-based ink composition is preferably 0.01 to 2% by mass, preferably 0.1 to 1% by mass, based on the total mass of the water-based ink composition. It is more preferable, and it is more preferable that it is 0.1 to 0.8% by mass.

(Complementary color pigment)
The water-based ink composition may contain complementary pigments in order to adjust the color of the resulting writing line. The complementary color pigment is not particularly limited, and pigments of various colors such as red, blue, yellow, green, white, and black can be used. Examples of complementary color pigments include SP4359, SP5658 and SP9604 (manufactured by Fuji Dye Co., Ltd.).

The content of the complementary color pigment in the water-based ink composition is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass, based on the total mass of the water-based ink composition.

(others)
Further, the water-based ink composition may contain an antibacterial agent, a rust preventive agent, a pH adjuster, a bubble suppressant, a bubble absorber, a shear thinning agent, a viscosity adjusting agent and the like, if necessary.

(Manufacturing method of water-based ink composition)
The water-based ink composition for writing tools of the present invention can be produced by any conventionally known method. Specifically, each of the above components can be blended in a required amount and mixed with various stirrers such as a propeller stirrer, a homodisper, or a homomixer, or various dispersers such as a bead mill to produce the product.

(Stationery)
The water-based ink composition of the present invention can be used for a pen core such as a fiber tip, a felt tip, a plastic tip, a marker with a ballpoint pen tip as a pen tip, a ballpoint pen, or a writing instrument such as a fountain pen using a metal pen tip. can. Among them, in order to improve the writing property on a non-permeable recording medium such as a film, it is preferable that the pen core is a fiber tip or a felt tip. In particular, it is preferably used as a marker. The porosity of the pen core is preferably 50 to 80%. When the porosity of the pen core is within the above numerical range, the brilliant pigment particles are not clogged, and the brilliance can be maintained at an appropriate ink ejection amount and writing line.

The writing tool of the present invention may be configured to be directly filled with the water-based ink composition, or may be provided with an ink container or an ink occlusion body capable of filling the water-based ink composition.

The writing instrument of the present invention is not particularly limited, and may be a cap-type writing instrument provided with a cap covering the pen tip, or a haunting-type writing instrument capable of accommodating the pen tip in the barrel. Examples of the infestation mechanism of the pen tip of the infestation type writing instrument include a knock type, a rotary type, and a slide type.

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

In one embodiment, the writing instrument is a marker and the pen tip is not particularly limited and may be, for example, a fiber tip, felt tip or plastic tip, and the shape thereof is bullet-shaped, chisel-shaped or brush. It may be a pen type or the like.

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

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Example 101)
A water-based ink composition for writing tools was obtained by mixing and dissolving the following raw materials and blending amounts at 25 ° C. for 20 minutes using a stirrer. The viscosity of the obtained aqueous ink composition was measured with an E-type rotational viscometer (DV-II + Pro, cone-type rotor CPE-42, manufactured by Brookfield), and the viscosity index was calculated based on the viscosity. Specifically, the viscosity at 20 ° C. and a shear rate of 380 sec ^-1 (rotation speed 100 rpm) was 9.54 mPa · s, and the viscosity at a shear rate of 456 sec ^-1 (rotation speed 120 rpm) was 9.39 mPa · s. .. From these viscosities, the viscosity index was calculated to be 0.91. Further, as a result of measuring the pH of the aqueous ink composition at 20 ° C. using an IM-40S type pH meter (manufactured by DKK-TOA CORPORATION), the pH was 7.9.
Further, the compounding ratio of the polyolefin resin particles to the bright pigment particles of Example 101 was 0.10 times based on the mass.
・ Glittering pigment particles 12% by mass
(Silica-coated plate-shaped aluminum particles, average particle diameter: 7 μm, aspect ratio: 25, silica coating amount: 14 parts by mass, solid content: 40%, manufactured by Toyo Aluminum Co., Ltd., trade name: EMR-D6390)
-Polyolefin resin particles 0.5% by mass
(Modified polyethylene, average particle size: 8 μm, solid content: 100%, manufactured by Tetsutani Co., Ltd., trade name: CERAFLOUR929)
-Elastic polymer 7.5% by mass
(Styrene-butadiene elastomer, solid content: 46%, Tg: 5 ° C., manufactured by Asahi Kasei Chemicals Co., Ltd., trade name: L-1924)
-Cellulose derivative 1.75% by mass
(Carboxymethyl cellulose, solid content: 100%, degree of etherification: 0.70 to 0.80, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: cellogen 5A)
・ Water-soluble acrylic polymer 3% by mass
(Solid content: 30%, manufactured by Fuji Dye Co., Ltd., product name: A-29 NH3)
・ Surfactant 0.5% by mass
( Acetylene glycol- based surfactant, manufactured by Nissin Chemical Industry Co., Ltd., trade name: Orphine EXP4200)
・ Antibacterial agent 0.5% by mass
(Made by Lonza Japan Co., Ltd., Product name: Proxel XL-2)
・ Tap water 74.25% by mass

(Examples 102 to 105, Comparative Examples 101 to 104)
The ink compositions of Examples 102 to 105 and Comparative Examples 101 to 104 were obtained by changing the types and amounts of the components to be blended with respect to Example 101 as shown in Table 1. Details of the materials used in these examples are as follows.
<Polyolefin resin particles>
CERAFLOUR950 (modified high-density polyethylene, average particle size: 9 μm, solid content: 100%, manufactured by Tetsutani Co., Ltd.)
AQUAMAT272 (modified polyethylene, average particle size: 30 μm, solid content: 55%, manufactured by Tetsutani Co., Ltd.)
Chemipal W400 (small molecule polyethylene, spherical particles, weight average molecular weight: 7000, average particle size: 4 μm, solid content: 40%, manufactured by Mitsui Chemicals, Inc.)
Chemipal W401 (small molecule polyethylene, spherical particles, weight average molecular weight: 6000, average particle size: 1 μm, solid content: 40%, manufactured by Mitsui Chemicals, Inc.)
<Water-soluble acrylic polymer>
John Krill 60J (manufactured by BASF Japan Ltd.)
John Krill 70J (manufactured by BASF Japan Ltd.)

(Comparative Example 105)
The ink composition of Comparative Example 105 was obtained by changing the types and amounts of the components to be blended with respect to Example 101 as follows. As a result of measuring the viscosity of the aqueous ink composition at 20 ° C. and a shear rate of 380 sec ^-1 (rotation speed 100 rpm), the viscosity was 57.1 mPa · s. Further, as a result of measuring the viscosity of the aqueous ink composition at 20 ° C. and a shear rate of 456 sec ^-1 (rotation speed 120 rpm), the viscosity was 52.7 mPa · s. The viscosity index was 0.56. When the scratch resistance test (writing on a polypropylene sheet) described later was performed using the ink composition of Comparative Example 105, the writing line was not fixed and it was practically impossible.
-Glittering pigment particles 3.9% by mass
(Made by Toyo Aluminum Co., Ltd., Product name: EMR-D6390)
・ Complementary color pigment 1 17.3% by mass
(Solid content: 50%, manufactured by Nippon Fluorescent Co., Ltd., product name: Lumicol NKW2317G)
・ Complementary color pigment 2 25% by mass
(Solid content: 23%, manufactured by Fuji Dye Co., Ltd., product name: SP568)
・ Surfactant 1.0% by mass
(Phosphate ester, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Plysurf 213B)
・ Antibacterial agent 0.5% by mass
(Made by Lonza Japan Co., Ltd., Product name: Proxel XL-2)
・ Moisturizer 7.2% by mass
(Urea, manufactured by Wako Pure Chemical Industries, Ltd.)
・ PH adjuster 2.7% by mass
(Triethanolamine, manufactured by Wako Pure Chemical Industries, Ltd.)
・ Sugar 1.45% by mass
(Dextrin, manufactured by Sanwa Cornstarch Co., Ltd., trade name: Sandeck # 70)
・ Gelling agent 0.22% by mass
(Sakushino glycan, manufactured by Sansho Co., Ltd., product name: Maypoli)
・ Solvent 15% by mass
(Glycerin, manufactured by Lion Corporation, trade name: purified glycerin D)
・ Tap water 25.73% by mass

<Abrasion resistance test>
The ink container of the marker provided with the pen tip was filled with the water-based ink compositions obtained in Examples 101 to 105 and Comparative Examples 101 to 104, and the pen tip was impregnated with the water-based ink composition. For the pen tip, a pen core having a bullet-shaped polyester fiber core having a porosity of 65% was used. With this marker, writing was done on a writing test sheet and a polypropylene sheet. After leaving this writing line for one day, it is rubbed 50 times with a cotton cloth under a load of 200g using a Gakushin type friction fastness tester (manufactured by Tester Sangyo Co., Ltd.), and the writing line after rubbing is used as the initial writing line. In comparison, the abrasion resistance was evaluated according to the following criteria. The evaluation results are also summarized in Table 1. JIS P3201 writing paper A was used as the writing test paper.
The evaluation criteria are as follows.
A: There is no peeling of the writing line B: There is some peeling of the writing line but there is no practical problem C: There is peeling of the writing line but it is practical D: There is peeling of the writing line and it is practical Items of concern E: There is a lot of peeling of the writing line, and there is a great concern in practical use.

<Brightness test>
Writing was performed on a writing test paper and a polypropylene sheet using the markers used in the abrasion resistance test, and the brilliance of each writing line was visually evaluated according to the following criteria. The evaluation results are also summarized in Table 1. JIS P3201 writing paper A was used as the writing test paper. The evaluation criteria are as follows.
A: Has a high metallic luster B: Has a metallic luster C: Has no metallic luster

(Example 201)
An ink composition for writing utensils was obtained in the same manner as in Example 101 except that the following raw materials and blending amounts were changed as follows. Further, as a result of measuring and calculating the viscosity, viscosity index and pH in the same manner as in Example 101, the viscosity was 9.02 mPa · s (shear rate: 380 sec ^-1 , rotation speed: 100 rpm), 8.80 mPa · s (shear rate: 380 sec -1). Shear rate: 456 sec ^-1 , rotation speed: 120 rpm), viscosity index was 0.86, and pH was 8.0.
・ Glittering pigment particles 12% by mass
(Plate-shaped aluminum particles, manufactured by Toyo Aluminum Co., Ltd., trade name: EMR-D6390)
・ Polyolefin resin particles 1% by mass
(Mitsui Chemicals, Inc., product name: Chemipearl W401)
-Elastic polymer 7.5% by mass
(Styrene-butadiene elastomer, manufactured by Asahi Kasei Chemicals Co., Ltd., trade name: L-1924)
-Cellulose derivative 1.75% by mass
(Carboxymethyl cellulose, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Cellogen 5A)
・ Water-soluble acrylic polymer 3% by mass
(Made by Fuji Dye Co., Ltd., Product name: A-29 NH3)
・ Surfactant 0.5% by mass
( Acetylene glycol- based surfactant, manufactured by Nissin Chemical Industry Co., Ltd., trade name: Orphine EXP4200)
・ Antibacterial agent 0.5% by mass
(Proxel XL-2, manufactured by Lonza Japan Co., Ltd.)
・ Tap water 73.75% by mass

(Examples 202 to 207, Comparative Examples 201 to 206)
The ink compositions of Examples 202 to 207 and Comparative Examples 201 to 206 were obtained by changing the types and amounts of the components to be blended with respect to Example 201 as shown in Table 2. Details of the materials used in these examples are as follows.
<Complementary color pigment>
SP4359 (manufactured by Fuji Dye Co., Ltd., solid content: 23%)
SP5658 (manufactured by Fuji Dye Co., Ltd., solid content: 23%)
<Elastic polymer>
John Krill PDX-7341 (manufactured by BASF Japan Ltd., acrylic elastomer, Tg: 15 ° C., solid content: 49%)
AE986B (manufactured by E-Tech Co., Ltd., acrylic elastomer, Tg: 2 ° C, solid content: 35%,)
John Krill 352D (manufactured by BASF Japan Ltd., acrylic elastomer, Tg: 56 ° C., solid content: 45%)
<Surfactant>
Dynol 604 (manufactured by Nissin Chemical Industry Co., Ltd., acetylene glycol-based surfactant)
<Glittering pigment particles>
Stapa IL Hydrolan 2192 (manufactured by Ecult, plate-shaped aluminum particles, solid content: 40%, average particle size: 15 μm, silica coating amount: 4 parts by mass)

<Abrasion resistance test>
The above conditions and evaluation criteria were used except that the water-based ink composition to be filled in the ink container of the marker provided with the pen tip was changed to the water-based ink compositions obtained in Examples 201-207 and Comparative Examples 201-204. In the same way, the scratch resistance was evaluated. The evaluation results are summarized in Table 2.

(Example 301)
An ink composition for writing utensils was obtained in the same manner as in Example 101 except that the following raw materials and blending amounts were changed as follows. Further, as a result of measuring and calculating the viscosity, viscosity index and pH in the same manner as in Example 101, the viscosity was 9.02 mPa · s (shear rate: 380 sec ^-1 , rotation speed: 100 rpm), 8.80 mPa · s (shear rate: 380 sec -1). Shear rate: 456 sec ^-1 , rotation speed: 120 rpm), viscosity index was 0.86, and pH was 8.0.
・ Glittering pigment particles 12% by mass
(Plate-shaped aluminum particles, manufactured by Toyo Aluminum Co., Ltd., trade name: EMR-D6390)
・ Polyolefin resin particles 1% by mass
(Mitsui Chemicals, Inc., product name: Chemipearl W401)
-Elastic polymer 7.5% by mass
(Styrene-butadiene elastomer, manufactured by Asahi Kasei Chemicals Co., Ltd., trade name: L-1924)
-Cellulose derivative 1.75% by mass
(Carboxymethyl cellulose, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: cellogen 5A)
・ Water-soluble acrylic polymer 3% by mass
(Made by Fuji Dye Co., Ltd., Product name: A-29 NH3)
・ Surfactant 0.5% by mass
( Acetylene glycol- based surfactant, manufactured by Nissin Chemical Industry Co., Ltd., trade name: Orphine EXP4200)
・ Antibacterial agent 0.5% by mass
(Made by Lonza Japan Co., Ltd., Product name: Proxel XL-2)
・ Tap water 73.75% by mass

(Examples 302 to 308)
The ink compositions of Examples 302 to 308 were obtained by changing the types and amounts of the components to be blended with respect to Example 301 as shown in Table 3. Details of the materials used in these examples are as follows.
<Complementary color pigment>
SP4359 (manufactured by Fuji Dye Co., Ltd., solid content: 23%)
SP5658 (manufactured by Fuji Dye Co., Ltd., solid content: 23%)
<Elastic polymer>
John Krill PDX-7341 (manufactured by BASF Japan Ltd., acrylic elastomer, Tg: 15 ° C., solid content: 49%)
AE986B (manufactured by E-Tech Co., Ltd., acrylic elastomer, Tg: 2 ° C, solid content: 35%,)

<Time-lapse test>
The aqueous ink compositions of Examples 301 to 308 were placed in a close-opening glass test tube having a diameter of 15 mm and left at room temperature for 14 days. Then, each glass test tube once settled was shaken up and down, and the redispersed state of the aqueous ink composition was observed under a microscope. The aggregated state was evaluated according to the following criteria. The evaluation results obtained are summarized in Table 3. The evaluation criteria are as follows.
A: Easily redispersed by shaking B: Redispersed by shaking but taking a long time C: Not sufficiently redispersed by shaking D: Not redispersed by shaking

Claims (8)

It contains bright pigment particles, polyolefin resin particles, an agglutination control agent, and a solvent.
The compounding ratio of the polyolefin resin particles to the glittering pigment particles is 0.01 to 1.0 times based on the mass.
The viscosity index n at 20 ° C. is 0.7 to 1.0.
The aggregation control agent contains an elastic polymer and a cellulose derivative, and contains
The brilliant pigment particles are water-based ink compositions for writing instruments, characterized in that the metal pigment particles are coated with silica. The composition according to claim 1, wherein the pH value of the water-based ink composition for writing tools is 6.0 to 10.0. The composition according to claim 1 or 2, wherein the content of the polyolefin resin particles is 0.01 to 10% by mass based on the total mass of the water-based ink composition for writing utensils. The composition according to any one of claims 1 to 3, wherein the average particle size of the bright pigment particles is 1 μm to 30 μm. The composition according to any one of claims 1 to 4, wherein the average particle size of the polyolefin resin particles is 0.1 μm to 35 μm. The composition according to any one of claims 1 to 5, wherein the bright pigment particles have an aspect ratio of 1 to 100. The composition according to any one of claims 1 to 6 , further comprising a water-soluble acrylic polymer. A writing instrument comprising the composition according to any one of claims 1 to 7.