TW202130752A - Ink composition for aqueous ballpoint pen being characterized by at least containing an aluminum pigment and 8 mass% to 25 mass% of dense urethane-based particles with the average particle size of 0.3[mu]m to 10[mu]m - Google Patents

Abstract

This invention provides an ink composition for an aqueous ballpoint pen and an aqueous ballpoint pen, wherein the ink composition is applicable to a fine-writing ballpoint pen to stably discharge ink, and to provide excellent lightness feeling of tracing lines without causing ball falling. The ink composition for the aqueous ballpoint pen, provided by this invention, is characterized by at least containing an aluminum pigment and 8 mass% to 25 mass% of dense urethane-based particles with the average particle size of 0.3[mu]m to 10[mu]m. In addition, the aqueous ballpoint pen provided by this invention is characterized by being filled with the ink composition for the aqueous ballpoint pen.

Description

Ink composition for water-based ball pen

The present invention relates to an ink composition for water-based ball pens containing aluminum pigments.

In the past, water-based ballpoint pens using aluminum powder as a pigment have been able to obtain bright lines, but their performance is the one that influences the size of the aluminum powder. Although large aluminum pigments show a strong sense of brilliance, they tend to cause a problem that the gaps in the pen tip are easily clogged. Especially in the case of a so-called fine-character ball pen with a ball diameter of 0.5 mm or less, the gap change is small, and the aforementioned problems are more likely to occur. In addition, since the so-called small ink discharge amount of the fine-character ball pen is small, there is also a problem that it is difficult to obtain a bright feeling.

Therefore, as inventions such as water-based ball pens to solve such problems, for example, 1) In order to suppress the aggregation of metal particles, balls of acrylic resin, styrene/acrylic copolymer, polyolefin, etc. are blended. In order to prevent the abrasion of the base, the ball-point pen and other writing instruments made of shaped resin particles (for example, refer to Patent Document 1) and 2) Ballpoint pens (for example, refer to Patent Documents 2 and 3), 3) The cleanliness of the ball of the ballpoint pen tip is movable within a specified range, and the ballpoint pen that can be rotated by holding it (for example, refer to Patent Document 4), etc.

However, even if the technical contents (inventions) of the above-mentioned Patent Documents 1 to 4 are known, the so-called fine-character ball pens with a ball diameter of 0.5 mm or less are not yet sufficiently effective, and the ball diameter exceeds Compared with a ball pen of φ0.5mm, the ball retention force is reduced, and the ball tends to fall off due to the usage conditions. In addition, although the design of the ballpoint pen tip may remedy this tendency, there may be disadvantages such as reduced writing feeling and reduced ink discharge. Furthermore, the holding of the ball is performed by pressing the tip of the holder that holds the ball, but the pressing part is worn due to writing, or by the embedding between the inner surface of the pressing part and the ball. The problem of localized stress and strain caused by solid objects, reduced holding force, and impact, etc., may cause the ball to fall off and make it impossible to write. Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Laid-Open No. 2010-125841 (application scope, examples, etc.) Patent Document 2: Japanese Patent Application Laid-Open No. 2014-129440 (application scope, examples, etc.) Patent Document 3: Japanese Patent Application Laid-Open No. 2017-119862 (application scope, examples, etc.) Patent Document 4: Japanese Patent Application Laid-Open No. 11-28887 (application scope, examples, figure 1, etc.)

The problem to be solved by the invention

In view of the above-mentioned problems of the prior art, the present invention intends to eliminate such problems, and provides a water-based ball-point pen ink that has stable ink discharge performance, excellent brilliance in line drawing, and does not cause the ball to fall off even if it is called a fine-character ball pen. The composition and the water-based ballpoint pen serve as the purpose. Means to solve the problem

The inventors of the present inventors have conducted diligent research in view of the above-mentioned conventional problems, and found that by containing at least a specific amount of aluminum pigment and particles with specific physical properties with an average particle diameter in a specified range, the water-based ballpoint pen for the above-mentioned purpose can be obtained. Ink composition, etc., and finally completed the present invention.

That is, the water-based ball pen ink composition of the present invention is characterized by containing at least an aluminum pigment and 8-25% by mass of dense urethane-based particles with an average particle diameter of 0.3-10 μm. In addition, the water-based ballpoint pen of the present invention is characterized in that it is equipped with the ink composition for water-based ballpoint pen having the above-mentioned structure. In the present invention, the lower limit xx to the upper limit zz of the numerical range include those of xx and zz. Invention effect

According to the present invention, there is provided an ink composition for a water-based ball-point pen and a water-based ball-point pen, which have stable ink discharge performance, excellent brilliance of line drawing, and no rolling-off of balls.

In the following, embodiments of the present invention will be described in detail. The water-based ink composition for a ball pen of the present invention is characterized by containing at least an aluminum pigment and 8-25% by mass of dense urethane-based particles with an average particle diameter of 0.3-10 μm.

The aluminum pigment can be used in the present invention. Generally speaking, if aluminum is pulverized and pulverized in the presence of a ball mill or grinder in the presence of a pulverizing medium, it is manufactured by pulverizing and pulverizing it as a pigment for water-based ink. The manufacturing method, properties (powder, paste, etc.), particle size (average particle diameter, thickness), etc., are not particularly limited. For example, those commercially available as aqueous inks can be used. Preferably, from the viewpoint that the effect of the present invention can be more exhibited, the average particle diameter is desirably 20 μm or less, and it is desirably 5 to 16 μm.

As the aluminum pigments that can be used, commercially available products include, for example, WXM series in which the aluminum surface is treated with phosphorus compounds, WL series in which the aluminum surface is treated with molybdenum compounds, and aluminum flakes. EMR series [above made by Toyo Aluminium Co., Ltd.] and SW-120PM [above made by Asahi Kasei Chemical Co., Ltd.] coated with high-density silicon dioxide. These can be used alone or in combination of two or more.

The content of these aluminum pigments is preferably 0.1 to 20% by mass relative to the total amount of the water-based ink composition for writing instruments (hereinafter, simply referred to as "the total amount of ink composition") (hereinafter, the "mass%" is simply referred to as Is "%"), preferably 2-10%. When the content of the aluminum pigment is less than 0.1%, the gloss cannot be obtained. On the other hand, when the content exceeds 20%, the writing feeling may be reduced, and the stability of the ink may be impaired.

The urethane-based particles used in the present invention are dense and have an average particle diameter of 0.3 to 10 μm. In the present invention, the term "dense" refers to particles such as hollow particles or microcapsule particles that have no voids (including single voids, multiple voids, and porous shapes), and there are no voids in the particles. The average particle diameter of the urethane-based particles used is 0.3-10 μm, and the lower limit is desirably preferably 0.5 μm or more, more preferably 0.9 μm or more, and particularly preferably 1.0 μm or more. On the other hand, the desired upper limit is preferably 8 μm or less, more preferably 6 μm or less. When the average particle size is less than 0.3 μm, the aluminum pigment surface may be coated with particles on the writing line, which may impair the brightness. On the other hand, when the average particle size exceeds 10 μm, the dispersion and stability of the particles are difficult, and the inside of the pen tip is likely to be clogged. Bad. In the present invention, the "average particle diameter" refers to the value of D50 calculated on the basis of volume by the laser diffraction method. Here, the measurement of the average particle size by the laser diffraction method can be performed, for example, by using the particle size distribution analyzer HRA9320-X100 of Nikkiso Co., Ltd.

The urethane-based particles used in the present invention have a certain size (range of the above-mentioned average particle diameter) as described above, and dense particles become important. In the present invention, by using those that become dense particles, it becomes easier to control the strength of the particles compared with particles such as microcapsules. It is desirable that the urethane-based particles to be used preferably have a 10% strength measured by a micro-compression test of 30 MPa or less. As a result, the urethane-based particles can become soft particles even if they are dense, and because they are soft, they have the characteristic of not causing the balls to fall off even if they are pinched between the pressed rubber and the balls. In addition, when the 10% strength is set to 5 MPa or more, the ink will flow out more stably. That is, by setting the aforementioned 10% strength to 5-30 MPa, it becomes possible to have both excellent ink flow stability and the characteristics of not causing the balls to fall off. In the present invention, the "micro compression test" can be performed, for example, using MCT-510 manufactured by Shimadzu Corporation. In this case, it can be set as the average of 5 particles. This 10% strength can be calculated by the following formula. C(x)=(2.48×P)/(π×d ² ) C(x): 10% strength/MPa P: test force when 10% of particle size is displaced/N d: particle size/mm

The urethane-based particles used are dense, if they have the above average particle size, and if the 10% strength measured by a micro-compression test has the above characteristics, it is particularly preferred, and it can be a commercially available product. It may be produced by the production method described later, and the urethane-based particles may be colored if they have the above-mentioned characteristics. Coloring When the urethane-based particles of the present invention are used as a coloring material (coloring agent), compared with microcapsule particles, since the color development property is high, the addition amount can be reduced. The microcapsule particles limit the amount of color material that can be contained, and also have problems such as the shell hindering color development. In the present invention, the urethane-based particles in the coloring are used as a coloring agent to increase the freedom of ink blending. Furthermore, in the present invention, when the urethane-based particles are not colored and other colorants are not included in the ink composition, the hue of the ink composition becomes aluminum pigment + uncolored urethane-based particles , And become silver (aluminum pigment + uncolored urethane-based particles).

The urethane-based particles used are polymers or copolymers with urethane bonds, which are obtained by reacting isocyanate components (including diisocyanate components) and polyol components (including diol components) Examples of these include urethane particles (polyester urethane particles, polycarbonate urethane particles, polyether urethane particles, etc.), urethane particles・At least one of urea particles. The urethane-based particles to be used are preferred, and it is desirable to use those obtained by the following production method. The method for preparing urethane-based particles can be carried out by the following steps 1) to 3): 1) Preparation of an oil phase containing organic solvents and isocyanate monomers or isocyanate prepolymers and containing water-insoluble dyes when colored , 2) The preparation of the water phase by mixing water and dispersant, 3) The step of mixing the above-mentioned oil phase and the water phase to emulsify the components of the oil phase and then polymerize it.

The oil phase contains organic solvents, isocyanate monomers or isocyanate prepolymers, and water-insoluble dyes when colored. This organic solvent may contain a plurality of kinds. This oil phase can be achieved by heating the organic solvent to a specified temperature, adding water-insoluble dyes and stirring when coloring, and then adding the above-mentioned monomers or prepolymers, and then adding other organic solvents if necessary. Make. As the organic solvent, for example, phenyl glycol, benzyl alcohol, ethylene glycol monobenzyl ether, ethyl acetate, etc. can be used. In addition, phenyl alkyl sulfonate, ethylhexyl phthalate, dodecyl phthalate, ethylhexyl trimellitate, diethylene glycol dibenzoate, Dipropylene glycol dibenzoate, liquid xylene resin, etc.

As the isocyanate monomer or prepolymer, for example, hexamethylene diisocyanate, toluene (Tolylene) diisocyanate, diphenylmethane diisocyanate, xylene (Xylylene) diisocyanate, isophorone diisocyanate, isocyanate prepolymer can be used. Polymer and so on. As the isocyanate prepolymer, it is preferable to use a trimer such as a triol adduct of the above-mentioned isocyanate, an isocyanurate modified body, etc., from the viewpoint of changing the polymerization to good curing. In addition, as an auxiliary prepolymer together with the above-mentioned trimer, a dimer such as the above-mentioned isocyanate allophanate modified body can be used. In this preparation method, the above-mentioned 10% strength adjustment can be performed by selecting and adjusting the content of the isocyanate component (monomer or prepolymer, auxiliary monomer, auxiliary prepolymer) used, etc. In addition, the average particle size can be adjusted by controlling the stirring conditions during polymerization.

As the water-insoluble dye used for coloring, it is water-insoluble at room temperature. For example, salt-forming dyes, disperse dyes, oil-soluble dyes, etc. can be used, but from the viewpoint of color development, it is preferable to use Salt dye. Examples of salt-forming dyes include dyes having chemical structures of azo series, metal complex salt azo series, anthraquinone series, and metal phthalocyanine series. For example, Valifast (registered trademark) Black of Oriental Chemical Industry Co., Ltd. can be used. 1807, Valifast (registered trademark) Blue 2620, Valifast (registered trademark) Brown 2402, Valifast (registered trademark) Green 1501, Valifast (registered trademark) Orange 2210, Valifast (registered trademark) Pink 2310, Valifast (registered trademark) Red 1355, Valifast (Registered trademark) VIOLET 1701, Valifast (registered trademark) Yellow 1101, etc.

As the disperse dye, for example, at least one dye selected from the group consisting of C.I. Disperse Yellow 198, C.I. Disperse Yellow 42, C.I. Disperse Red 92, C.I. Disperse Violet 26, C.I. Disperse Violet 35, C.I. Disperse Blue 60, and C.I. Disperse Blue 87 can be used. Oil as a soluble dye, for example, Oil Black 860, Oil Blue 613, Oil Brown BB, Oil Green 530, Oil Orange 201, Oil Pink 312, Oil Red 5B, Oil Scarlet 318, Oil Yellow 105 of Dongfang Chemical Industry Co., Ltd. can be used. Wait.

The water phase can be made by mixing water and a dispersant. As a dispersing agent, although polyvinyl alcohol can be used, for example, it is not limited to this.

The emulsification and polymerization steps can be carried out by emulsifying the above-mentioned oil phase ingredients, and in the further polymerization step, putting the oil phase into the water phase, and heating to a specified temperature using a homogenizer, etc., while emulsifying and mixing , To obtain colored urethane-based particles and uncolored urethane-based particles.

Furthermore, in addition to the above-mentioned emulsion polymerization, urethane-based particles by a phase separation method can be produced. This manufacturing method consists of making a dye-containing solution during coloring, making a solution containing a protective colloid, and polymerizing isocyanate monomers or isocyanates. The dye-containing solution can be prepared by heating and dissolving the water-insoluble dye in an organic solvent. As the water-insoluble dye and organic solvent, the organic solvent used by the above-mentioned emulsion polymerization can be used.

The solution containing the protective colloid agent can be prepared by dissolving the protective colloid agent in water. As the protective colloid agent, for example, a methyl vinyl ether-maleic anhydride copolymer or the like can be used. The polymerization of isocyanate monomers or isocyanate prepolymers can be done by adding a solution containing a dye to a solution containing a protective colloid that is heated to a specified temperature during coloring to disperse it into oil droplets and add it here The above-mentioned isocyanate monomer or isocyanate prepolymer is manufactured by maintaining the temperature and stirring.

These dense urethane-based particles can be used alone or in combination of two or more, and the content is desirably 8 to 25%, preferably 10 to 18% relative to the total amount of the ink composition. When the content of the dense urethane-based particles is less than 8%, the effect of the present invention cannot be exhibited. On the other hand, when the content exceeds 25%, the stability of the ink may be impaired, which is not preferable.

The water-based ball pen ink composition of the present invention contains at least 8-25% by mass of the above-mentioned aluminum pigment and dense urethane-based particles with an average particle diameter of 0.3-10 μm, in addition to these components, In a range that does not impair the effects of the present invention, for example, other color materials such as pigments or dyes, water-soluble organic solvents, and water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.) as residual solvents may be appropriately contained, and further , If necessary, it can contain various components commonly used in writing instrument water-based ink compositions, such as thickeners, lubricants, rust inhibitors, preservatives or antibacterial agents, pH adjusters, etc.

In the present invention, in addition to the above-mentioned aluminum pigments and urethane-based particles during coloring, other color materials (colorants) such as pigments or dyes can be used in combination as complementary color components if necessary. As a color material that can be used, within a range that does not impair the effects of the present invention, conventionally known inorganic and organic pigments such as dyes, titanium oxide, etc., which are dissolved or dispersed in water, and silica or mica can be used in appropriate amounts. The base material, and the surface layer is coated with iron oxide or titanium oxide pigments, etc. in multiple layers. Examples of dyes include acid dyes such as eosin, rose bengal, water yellow #6-C, acid red, water blue #105, brilliant blue FCF, nicotine NB, etc.; Direct black154, Direct Sky Blue5B, Violet B00B, etc. Dyes; basic dyes such as rhodamine, methyl violet, etc.

Examples of organic pigments include Azo lake, insoluble azo pigments, chelating agent azo pigments, phthalocyanine pigments, perylene and perylene pigments, nitroso pigments, and the like. More specifically, carbon black, titanium black, zinc oxide, iron oxide red, chromium oxide, iron black, cobalt blue, iron oxide yellow, chrome green, zinc sulfide, Lithopone, cadmium yellow, red , Cadmium red, yellow lead, molybdenum orange, zinc chromate, strontium chromate, white carbon, clay, talc, ultramarine, precipitated barium sulfate, barite powder, calcium carbonate, white lead, dark blue , Navy blue, manganese violet, brass powder, etc. inorganic pigments, CI Pigment Blue 15, CI Pigment Blue 17, CI Pigment Blue 27, CI Pigment Red 5, CI Pigment Red 22, CI Pigment Red 38, CI Pigment Red 48, CI Pigment Red 49, CI Pigment Red 53, CI Pigment Red 57, CI Pigment Red 81, CI Pigment Red 104, CI Pigment Red 146, CI Pigment Red 245, CI Pigment Yellow 1, CI Pigment Yellow 3, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 17, CI Pigment Yellow 34, CI Pigment Yellow 55, CI Pigment Yellow 74, CI Pigment Yellow 95, CI Pigment Yellow 166, CI Pigment Yellow 167, CI Pigment Organic pigments such as Orange 5, CI Pigment Orange 13, CI Pigment Orange 16, CI Pigment Violet 1, CI Pigment Violet 3, CI Pigment Violet 19, CI Pigment Violet 23, CI Pigment Violet 50, CI Pigment Green 7, etc. These color materials can be used alone or in a mixture of two or more.

Examples of usable water-soluble organic solvents include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, 3-butanediol, thiodiethylene glycol, and glycerin. Alcohols, or ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, etc., these can be used alone or in combination of two or more. The content of these water-soluble organic solvents is appropriately adjusted for each use of the water-based ink composition for writing instruments, relative to the total amount of the ink composition, in the range of 1% to 30%.

As the usable thickener, for example, it is desirable to be at least one selected from the group consisting of synthetic polymers, cellulose, and polysaccharides. Specifically, gum arabic, tragacanth gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, Welan gum, and succinoglycan can be cited. (succinoglycan), Diutan gum, dextran, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, starch glycolic acid and its salts, polyvinyl Pyrrolidone, polyvinyl methyl ether, polyacrylic acid and its salt, polyethylene oxide, copolymer of vinyl acetate and polyvinyl pyrrolidone, styrene-acrylic acid copolymer and its salt, etc.

As lubricants, nonionics such as fatty acid esters of polyhydric alcohols, higher fatty acid esters of sugars, and higher fatty acid esters of polyoxyalkylenes, which can also be used as surface treatment agents for pigments, or phosphoric esters and higher fatty acids Alkyl sulfonate of amide, anion of alkyl allyl sulfonate, etc., derivatives of polyalkylene glycol or fluorine-based surfactants, polyether modified polysiloxane, etc.

In addition, as rust inhibitors, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, saponin, etc. can be cited, and as preservatives or antibacterial agents, phenol, omadine (Omadine) can be cited. ), sodium benzoate, benzisothiazoline, benzimidazole compounds, etc. Examples of pH adjusters include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide, triethanolamine, diethanolamine, monoethanolamine, dimethylethanolamine, morpholine, triethylamine, etc. Amine compounds, ammonia, etc.

The water-based ink composition for a ballpoint pen of the present invention can be prepared by containing at least the above-mentioned aluminum pigment, and 8-25% by mass of dense urethane-based particles with an average particle diameter of 0.3-10μm, and adapting the other components to the ballpoint pen. The structure is appropriately combined, and the mixture is stirred and mixed with a mixer such as an emulsifier (Homomixer), a homogenizer (Homogenizer), or a disperser, and then the ink composition can be removed by filtration or centrifugal separation if necessary. Coarse particles, etc., to prepare an ink composition for water-based ballpoint pens. The resulting water-based ink composition for a ballpoint pen of the present invention is mounted on a ballpoint pen provided with a ballpoint pen tip for use.

The water-based ink composition for a ballpoint pen of the present invention constituted in this way becomes a so-called fine-character ballpoint pen with a ball diameter of φ0.5mm or less. The ink dischargeability is stable, and the tracing is excellent in brightness and does not cause the ball to fall off. The ink composition for a ballpoint pen is estimated as follows. The water-based ball pen ink composition of the present invention contains at least an aluminum pigment and 8-25% of urethane-based particles with an average particle diameter of 0.3-10 μm. By containing 8-25% of the urethane-based particles, although it is presumed, by suppressing the aggregation of aluminum pigments, and even if the urethane-based particles are embedded between the inner surface of the press part and the balls , There is no localized stress and strain, no reduction in ball retention, etc., it becomes a water-based ball pen ink composition that can obtain stable ink discharge, excellent brilliance of the line, and does not cause the ball to fall off.

As the water-based ballpoint pen of the present invention, for example, while the water-based ball-point pen ink composition of the above-mentioned composition is contained in an ink container (refill) for a ball-point pen, it has no phase with the water-based ink composition contained in the ink container. A substance that is soluble and has a relatively small specific gravity with respect to the aqueous ink composition, for example, at least one of polybutene, silicone oil, mineral oil, etc. can be used as the ink follower container. The structure of the ballpoint pen is not particularly limited. For example, the barrel itself may be used as an ink container, and the barrel may be provided with a connector structure (ink holding mechanism) filled with the above-structured water-based ink composition for ballpoint pens. Liquid ball pen.

In the water-based ball-point pen of the present invention, it is preferable to set the ball diameter of the water-based ball-point pen as D and the maximum outer ball size as L, as shown in FIG. The value is set at 27-37, and it is more desirable to set it at 28-36. X=(L/D)×100 ………(I) D: Ball diameter, L: Maximum outer ball size, L=(Outer ball size l + cleanliness m) It is more desirable to have the value of X represented by the above formula (I) and have a ball diameter (φ) of 0.5 mm or less, more preferably 0.3 mm or less, and particularly preferably 0.29 mm or less. By combining the water-based ball-point pen with this structure and the water-based ball-point pen ink composition with the above-mentioned characteristics, it is possible to obtain a water-based ball-point pen that is more resistant to floating balls and exhibits a better writing feeling.

In the water-based ball-point pen of the present invention, as a specific form of the water-based ball-point pen having the above-mentioned characteristics, the water-based ball-point pen of FIGS. 2 to 6 can be cited. Figure 2 shows an example of a ballpoint pen tip with a ball diameter (φ) of 0.5mm or less, more preferably 0.3mm or less, and particularly preferably 0.29mm or less, and Figure 3 shows another example of the ballpoint pen tip of Figure 2 , Figure 4 is a diagram showing the state of attaching the ballpoint pen tip of Figure 2 to the ink containing tube (pen core), and Figure 5 shows the ink containing tube (pen core) with the ballpoint pen tip of Figure 4 attached to the shaft Fig. 6 is a drawing showing another example of the water-based ball-point pen of Fig. 5 (press-type water-based ball-point pen body).

Figure 2 shows a ball-point pen tip A of the cannonball type. The tip of the pen tip A is formed in a tapered shape, and a ball 10 having a ball diameter of, for example, 0.29 mm or less, is wrapped in a freely rotatable hollow holder 11 at the tip. . The water-based ballpoint pen C with this ballpoint pen tip A is connected to the ink container by connecting the rear end side of the ballpoint pen tip A, for example, as shown in FIG. 4, through a joint member 20 (or directly) with a backflow prevention mechanism The tube 25 constitutes the refill 30, for example, as shown in FIG. Furthermore, a base 31 is fixed to the tip of the shaft 33. In addition, the icon 26 in FIG. 4 is the ink composition for the water-based ball pen of the present invention, 27 is the ink follower, and the icon 35 in FIG. 5 is a clip. Here, the water-based ballpoint pen C is filled with the ink composition 26 for the water-based ballpoint pen of the present invention that is filled in the ink containing tube 25 through the ink flow path 12 that is sequentially tapered, and is supplied to the ball 10.

Fig. 3 shows that the tip of a thin tube 15 made of metal or the like is pressed on the inside. For example, a ball 16 having a diameter (ball diameter) of 0.29 mm or less is wrapped in a freely rotatable needle-shaped ball pen tip B. This ballpoint pen tip B is also the same as the above, and its rear end side is connected with an ink container and a shaft (not shown) to constitute a water-based ballpoint pen. 6 is a longitudinal sectional view showing an example of a press-type water-based ball-point pen body in which an ink containing tube (pen core) having a ball-point pen tip of FIG. 2 is attached to a press-type shaft body. This push-type water-based ballpoint pen body E has the ballpoint pen tip 40 of FIG. 2, and the pen tip 40 is passed through the joint member 45 having a backflow prevention mechanism, and the pen core 47 connected to the ink container 46 is stored in the non-slip member 48 of the push-type shaft 50. Furthermore, the icon 41 in the figure is a coil spring member with a thin line at the tip which is housed in the pen tip, and the tip of the coil spring pushes the ball outwards by the elastic force of the coil spring. In the figure, the symbol 42 is the water-based ball pen ink composition of the present invention, 43 is the ink follower with the above characteristics, 51 is the pressing portion, and 52 is the coating member for protecting the tip of the pen tip.

The material of the ball is not particularly limited as long as the ball diameter (φ) is 0.5 mm or less, more preferably 0.3 mm or less, and particularly preferably 0.29 mm or less. Metal members such as superhard, Those made of ceramic members, and in order to improve the durability, corrosion resistance, etc., of the surface of the ceramic members, a film-coated member, etc., can be cited. As the lower limit of the ball diameter, from the viewpoint of manufacturing technology, etc., it is about 0.1 mm. As the material of the holder, metal made of nickel silver, brass, stainless steel, synthetic resin, etc. can be mentioned. In addition, as the ink containing tube, a synthetic resin product that can confirm the transparency or translucency of the ink remaining amount can be cited, but it may also be a metal product. Moreover, the water-based ballpoint pen of the present invention is not limited to the structure of the ballpoint pen tip of Figs. 2 and 3, if it is used with a ball diameter (φ) of 0.5 mm or less, more preferably 0.3 mm or less, It is preferable that the ballpoint pen tip with a ball of less than 0.29mm is not particularly limited in the structure of the water-based ballpoint pen body including the ballpoint pen tip, and for example, it is applicable to water-based ballpoint pens of various structures including the push type. In addition, the material and size (inner diameter, length) of the ball holder, ink containing tube, and joint member (pin shaft) are appropriately set in accordance with the structure of the nib, ball diameter, ink follower, etc.

In the water-based ballpoint pen of the present invention structured in this way, even if it is equipped with a ball-point pen tip with a ball diameter (φ) of 0.5 mm or less, more preferably 0.3 mm or less, and particularly preferably 0.29 mm or less, By using the water-based ink composition for a ballpoint pen of the present invention, it can be a water-based ballpoint pen with stable ink discharge performance, excellent brilliance in drawing lines, and no ball falling off. Especially in the water-based ball pen of the present invention, as shown in Fig. 1, the ball diameter of the water-based ball pen is set as D, and the maximum outer ball size is set as L, by using X expressed by the above formula (I) A ballpoint pen tip with a value of 27-37, combined with the water-based ballpoint pen ink composition of the present invention, can obtain stable ink discharge performance , excellent brilliance of the line, and no ball falling off, and furthermore, can obtain float resistance A water-based ball pen with ball performance and a better writing feeling. In this water-based ballpoint pen, the smaller the ball diameter (φ), the more the effect of the present invention can be exerted. It is suitable to use the ball diameter of 0.5mm or less, more preferably 0.3mm or less, particularly preferably 0.29mm or less. Water-based ball pen. Example 1

Next, although the present invention will be explained in more detail by the production examples (preparation of urethane-based particles, etc.), examples, and comparative examples (preparation of water-based ballpoint pen ink composition), the present invention is not limited to The following examples and so on. <Production of urethane-based particles A to F and melamine particles G> The urethane-based particles A to F and the melamine particles G were produced by the blending composition shown in Table 1 below and the following method.

(Production Example 1: Urethane-based particles A) While heating 12.5 parts by mass of ethyl acetate as an organic solvent to 60°C, an isocyanurate modifier of hexamethylene diisocyanate (TLA-100, Asahi Kasei Chemical Co., Ltd.) was added as a prepolymer. Preparation) 8 parts by mass to prepare an oil phase solution. On the other hand, while heating 200 parts by mass of distilled water to 60°C, 15 parts by mass of polyvinyl alcohol (PVA-205, manufactured by Kuraray Corporation) as a dispersant was dissolved to prepare an aqueous phase solution. Next, the 60° C. water phase solution was poured into the oil phase solution, and then stirred with a homogenizer for 6 hours, and emulsified and mixed to complete the polymerization. The obtained dispersion was centrifuged to obtain urethane-based particles (non-coloring) A.

(Production Example 2: Urethane-based particles B) While heating 11.5 parts by mass of ethylene glycol monobenzyl ether as an organic solvent to 60°C, diphenylmethane diisocyanate (3 mol) of trimethylolpropane (1 Mole) adduct (D-109, manufactured by Mitsui Chemicals Co., Ltd.) was 7.2 parts by mass to prepare an oil phase solution. On the other hand, while heating 200 parts by mass of distilled water to 60°C, 15 parts by mass of polyvinyl alcohol (PVA-205, manufactured by Kuraray Corporation) as a dispersant was dissolved to prepare an aqueous phase solution. The 60°C water phase solution was poured into the oil phase solution, stirred with a homogenizer for 6 hours, and emulsified to complete the polymerization. The obtained dispersion was centrifuged to obtain urethane-based particles (red particles) B.

(Production Example 3: Urethane-based particles C) In addition to changing 2.8 parts by mass of water-insoluble dye (Valifast Red 1355, manufactured by Oriental Chemical Industry Co., Ltd.) to 2.4 parts by mass of water-insoluble dye (Valifast Blue 2620, Oriental Chemical Industry Co., Ltd.), and changing 11.5 parts by mass of ethylene glycol monobenzyl ether 9.6 parts by mass of benzyl alcohol, and 7.2 parts by mass of trimethylolpropane (1 mol) adduct of diphenylmethane diisocyanate (3 mol) (D-109, manufactured by Mitsui Chemical Co., Ltd.) was changed to six The allophanate modified body of methylene diisocyanate (D-178NL, manufactured by Mitsui Chemicals Co., Ltd.) was carried out in the same manner as the urethane-based particles B except for 7 parts by mass to obtain urethane System particles (blue particles).

(Production Example 4: Urethane-based particles D) Except that the isocyanurate modified body of hexamethylene diisocyanate (TLA-100, Asahi Kasei Chemical Co., Ltd.) was changed from 8 parts by mass to 15 parts by mass, the rest was performed in the same manner as the urethane-based particles A. Thus, urethane-based particles (non-coloring) D were obtained.

(Production Example 5: Urethane-based particles E) In Production Example 2, the stirring conditions during polymerization were changed to obtain urethane-based particles (red particles) E having different average particle diameters.

(Production Example 6: Urethane-based particles F) In Production Example 3, the stirring conditions during the polymerization were changed to obtain urethane-based particles (blue particles) F having different average particle diameters.

(Production Example 7: Melamine particles G) Except that 12.5 parts by mass of ethyl acetate was defined as 20 parts by mass of benzyl alcohol, 8 parts by mass of the isocyanurate modified body of hexamethylene diisocyanate (TLA-100, manufactured by Asahi Kasei Chemical Co., Ltd.) was changed to methylol. Except for 7 parts by mass of the base melamine, the others were carried out in the same manner as the production method of the urethane-based particles A, and the melamine particles (uncolored) G were obtained.

The 10% strength (MPa) and average particle diameter (μm) of the obtained urethane-based particles A to F and melamine particles G were measured by the following methods. The results are shown in Table 1 below. (Method for measuring 10% strength) Use Shimadzu Corporation's MCT-510, and calculate with the above formula. (Method of measuring average particle size) Measured using Nikkiso Co., Ltd. particle size distribution analyzer HRA9320-X100.

＜Preparation of ink composition for water-based ball pen＞ (Examples 1 to 8 and Comparative Examples 1 to 3) From the blending composition shown in Table 2 below (100% by mass in total), a water-based ball-point pen ink composition was prepared by a conventional method. For the obtained water-based ink composition (100% by mass) of each writing instrument, the water-based ball pen with the following composition was used, and the following evaluation method was used to evaluate the ink discharge performance (line drawing evaluation, ink flow rate) and ball retention Evaluate. The results of these are shown in Table 2 below.

＜Production of water-based ball pen＞ It is made of polypropylene ink receiving tube (inner diameter 4mm, length 113mm), stainless steel nib based on Fig. The refill of the composition was filled with the ink composition for water-based ball pens of Examples 1 to 8 and Comparative Examples 1 to 3. Then, an ink follower made of mineral oil, polybutene, and olefin-based elastomer is filled at the rear end of the ink. This refill was placed on the shaft of a ball pen (UM-151, manufactured by Mitsubishi Pencil Co., Ltd.) to make each water-based ball pen. When the ball diameter D (0.38 mm) of the water-based ball pen used in this example and the comparative example is set as the maximum ball outer dimension L, the value of X represented by the above formula (I) is in the range of 27-37.

[Ink dischargeability (line drawing evaluation, ink flow rate)] Write with a φ0.38mm ball pen (according to JISS6061) until all the ink is consumed, and evaluate the state of the line drawing per 100m and the ink flow rate using the following evaluation criteria (A to C). ＜Evaluation criteria for line drawing evaluation＞ A: Has sufficient brightness B: The brightness is slightly weak C: Insufficient brightness ＜Evaluation standard of ink flow＞ A: Keep a certain flow until the end. B: The flow rate decreases slightly in the latter half. C: Occurs when it is impossible to write on the way or when the flow rate is extremely reduced.

[Ball retention] After writing to 200m with the same ball pen as described above, drop the pen tip upward from a height of 1.8m, and evaluate it according to the following evaluation criteria (A, C). n=50 only ＜Assessment criteria for ball retention＞ A: Keep all balls. C: A ball pen that has fallen off.

Numbers 1 to 5 in Table 2 above are as follows. 1: J-4PM, average particle size 2.4μm, 10% strength 33MPa, PMMA, manufactured by Nejo Kogyo Co., Ltd. 2: EMERAL EMR-D7675, average particle size 16μm, silicon dioxide coating, manufactured by Toyo Aluminum 3: EMERAL EMR-D5680, average particle size 8μm, silicon dioxide coating, manufactured by Toyo Aluminum 4: RD-510Y, manufactured by Toho Chemical Industry Co., Ltd. 5: KELSAN AR, manufactured by Sanjing Company

When examining the above-mentioned Tables 1 and 2, the examples 1 to 8 which are the scope of the present invention are compared with the comparative examples 1 to 3 which are outside the scope of the present invention, and it is judged that the ink dischargeability (line drawing evaluation, ink flow rate) and ball retention are excellent. . Specifically, the examples 1, 4 to 6 were used together with aluminum pigments with uncolored urethane-based particles, only the aluminum pigments of Comparative Examples 1 to 3 were compared with aluminum pigments + melamine particles or acrylic particles. Confirm that the ink discharge performance (line drawing evaluation, ink flow rate) and ball retention are excellent. In addition, the use of colored urethane-based particles (blue, red) together with the aluminum pigments of Examples 2, 3, 7 and 8, also confirmed that the ink discharge performance is the same as the excellent color development ( Line drawing evaluation, ink flow rate), ball retention is also excellent. Industrial availability

Obtain a suitable water-based ink composition for a ballpoint pen in a ballpoint pen.

A: Ballpoint pen tip B: Roller ball pen tip C: Ball pen 10: Ball 11: retainer 12: Ink flow path 15: thin tube 16: ball 20, 45: Joint components 26, 42: Ink composition for water-based ball pen 27, 43: Ink follower 30, 47: Refill 32, 48: non-slip member 35: Clip 40: Ballpoint pen nib 46: Ink Containment Tube 50: Push-type shaft 51: pressing part 52: envelope member

Fig. 1 is an enlarged longitudinal sectional view showing an example of a ballpoint pen tip of an aqueous ballpoint pen equipped with the ink composition for an aqueous ballpoint pen of the present invention. [Fig. 2] A longitudinal sectional view showing the tip of the ball pen of Fig. 1. [Fig. [Fig. 3] A longitudinal sectional view showing another example of the tip of a ball pen. [Fig. 4] is a longitudinal sectional view showing the state of attaching the tip of the ball pen of Fig. 2 to the ink container (pen core). Fig. 5 is a longitudinal cross-sectional view showing an example of an embodiment of the water-based ballpoint pen of the present invention, showing a state in which the ink containing tube (pen core) of Fig. 4 is attached to the shaft body to form a water-based ballpoint pen. [Figure 6] shows another example of the embodiment of the water-based ballpoint pen of the present invention. It is a vertical cross-sectional view showing that the ink container (refill) of Figure 4 is attached to the push-type shaft body to form a push-type water-based ballpoint pen .

D: Ball diameter

L: Maximum outer ball size

l: Outer size of ball

m: cleanliness

Claims (2)

An ink composition for a water-based ball pen, characterized by containing at least an aluminum pigment and 8-25% by mass of dense urethane-based particles with an average particle diameter of 0.3-10 μm. A water-based ball-point pen characterized by carrying the ink composition for water-based ball-point pens as described in claim 1.

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