JP5283250B2 - Water-based ink composition, method for producing the same, and writing instrument - Google Patents

Abstract

The invention aims at providing a water base metallic ink composition which less suffers from the reaction of metal powder pigment with water and is thus excellent in storage stability. A water base ink composition containing a metal powder pigment and water as the essential components, which further contains at least one phosphoric ester compound selected from among phosphoric esters represented by the general formula (1) and salts thereof: (1) wherein R<SUP>1</SUP> is C<SUB>6-18</SUB> alkyl or alkenyl; R<SUP>2</SUP> is hydrogen or R<SUP>3</SUP>(OCH<SUB>2</SUB>CH<SUB>2</SUB>)<SUB>n</SUB> (wherein R<SUP>3</SUP> is C<SUB>6-18</SUB> alkyl or alkenyl); and n is 0 to 3.

Description

  The present invention relates to a water-based ink composition containing a metal pigment, a method for producing the same, and a writing instrument using the water-based ink composition.

An ink composition that contains an aluminum powder pigment, a brass powder pigment, or the like and can make the handwriting metallic has been already known and is in practical use (for example, Patent Document 1). In addition, a double color ink composition that can produce a double color handwriting that further generates a contour line around the metallic handwriting has been proposed and put into practical use (for example, Patent Document 2). . These ink compositions are provided, for example, in the form of a ballpoint pen.
JP 2002-194261 A Japanese Patent Laid-Open No. 2002-60666

  In a so-called aqueous ink composition containing a metal powder pigment and containing water as a solvent, it is necessary to prevent the reaction between the metal and water. When the metal reacts with water, it may cause discoloration of the metal powder pigment and generation of hydrogen gas. Further, in the double color ink composition, the reaction between the metal and water may cause discoloration of the colorant (particularly water-soluble dye). Discoloration of the metal powder pigment and colorant has the disadvantage that the color and texture of the handwriting are not desired. In addition, when the ink composition is filled in an ink storage tube and the tube is plugged (that is, as a writing instrument) and stored for a long period of time, if hydrogen gas is generated, the plug may come loose or come off. There is.

  It is already known that these problems can occur. For this reason, the metal powder pigment is generally subjected to water resistance treatment and then used for the production of a water-based ink composition (for example, Patent Document 1 0013). However, it has been found that even when a metal powder pigment subjected to water resistance treatment is used, a reaction between the metal and water may occur.

  This invention is made | formed in view of this situation, and it aims at providing the water-based ink composition excellent in the storage stability by which reaction with a metal-powder pigment and water was suppressed more.

As a result of investigations by the present inventors, it has been found that when a specific phosphate compound and / or a salt thereof is contained in the ink composition, it is effective in suppressing the reaction between aluminum and water. It came to devise. That is, the present invention is an ink composition containing at least a metal powder pigment and water, comprising at least one phosphate ester compound selected from a phosphate ester compound represented by the following chemical formula (1) and a salt thereof: A water-based ink composition is provided.
(In the formula, R ¹ is an alkyl group or alkenyl group having 6 to 18 carbon atoms, R ² is hydrogen or R ³ (OCH ₂ CH ₂ ) _n (R ³ is an alkyl group having 6 to 18 carbon atoms). Or n is 0 to 3).

  In the water-based ink composition of the present invention, the metal powder pigment may be subjected to water resistance treatment in advance. In that case, the water-based ink composition of the present invention contains the specific phosphoric ester compound in addition to the water-resistant treatment agent previously contained in the metal powder pigment. Here, when the ink composition contains only the phosphoric acid ester compound represented by the above chemical formula (1), the “phosphoric acid ester compound” refers to the phosphoric acid ester compound. When only the salt of the phosphate ester compound represented by (1) is included, this salt is indicated, and when the ink composition contains both the phosphate ester compound represented by the above chemical formula (1) and its salt Refers to both compounds.

  The phosphate ester compound is preferably contained in the ink composition in an amount of 0.01% by mass to 2.0% by mass. If the content of the phosphate ester compound is too small, the reaction between the metal powder pigment and water cannot be sufficiently suppressed, and even if the content is large, the obtained effect remains unchanged.

  The water-based ink composition of the present invention may be a dual color ink composition. In that case, the water-based ink composition further includes a colorant.

  The water-based ink composition of the present invention is preferably used as an ink for a writing instrument. Therefore, the present invention also provides a writing instrument using the water-based ink composition of the present invention as an ink. The writing instrument is preferably a ballpoint pen.

The present invention is a method for producing the water-based ink composition of the present invention as described above.
Dispersing at least one compound selected from the phosphoric acid ester compound represented by the chemical formula (1) and a salt thereof in water;
Dispersing the metal powder pigment in water in which the phosphate ester compound is dispersed, and dispersing other components in water in which the phosphate ester compound and the metal powder pigment are dispersed, A method for producing a water-based ink composition is provided. According to this production method, the phosphate ester compound can be brought into good contact with the metal powder pigment in water, and the water resistance of the metal powder pigment can be further improved. Therefore, this manufacturing method is used when an ink composition is manufactured using a metal powder pigment that does not exhibit sufficient water resistance when a water-based ink composition is formed even though the water-resistant treatment is applied. It is preferably applied to.

The present invention also provides a method for improving the water resistance of a metal powder pigment contained in a water-based ink composition.
Dispersing at least one phosphate ester compound selected from the phosphate ester compound represented by the chemical formula (1) and a salt thereof in water;
Dispersing the metal powder pigment in water in which the phosphoric acid ester compound is dispersed, and water in which the phosphoric acid ester compound and the metal powder pigment are dispersed in the water-based ink composition. And a water-resistant treatment method for a metal powder pigment contained in a water-based ink composition. This treatment method is particularly used when a water-based ink composition is produced using a metal powder pigment that does not exhibit sufficient water resistance when it is made into a water-based ink composition even though it has been subjected to a water-resistant treatment in advance. Furthermore, it is preferably used as a method for improving the water resistance of the metal powder pigment.

  In the water-based ink composition of the present invention, the water resistance of the metal powder pigment is further improved by the specific phosphoric ester compound, and the reaction between the metal powder pigment and water is further suppressed. Therefore, the water-based ink composition of the present invention is less likely to cause discoloration and generation of hydrogen gas due to the reaction between the metal powder pigment and water, and is excellent in storage stability. Writing instruments (especially ballpoint pens) that use the aqueous ink composition of the present invention as ink give handwriting of a certain quality over a long period of time, and are less likely to cause looseness or detachment of the stopper, so that the user does not feel inconvenience. Can be used with confidence. The method for producing a water-based ink composition of the present invention is characterized in that a specific phosphate ester compound and a metal powder pigment are first dispersed in water. Due to this feature, the production method of the present invention makes it possible to obtain a water-based ink composition in which the water resistance of the metal powder pigment is effectively improved by the specific phosphate ester compound.

  The water-based ink composition of the present invention is an ink composition containing at least a metal powder pigment and water, and contains a specific phosphate ester compound. Hereinafter, the components contained in the water-based ink composition of the present invention will be described.

(Phosphate ester compounds)
In order to improve the water resistance of the metal powder pigment and prevent the reaction between the metal powder pigment and water, the water-based ink composition of the present invention comprises a phosphate ester compound represented by the following chemical formula (1) and a salt thereof. Including at least one selected compound.

In the chemical formula (1), R ¹ is an alkyl group or alkenyl group having 6 to 18 carbon atoms, R ² is hydrogen or R ³ (OCH ₂ CH ₂ ) _n (R ³ is 6 to 18 carbon atoms). N is 0-3. That is, the phosphoric acid ester compound represented by the chemical formula (1) is a monoester or a diester in which ethylene oxide is added to the alkyl or alkenyl of the phosphoric acid, or the alkyl or alkenyl group.

R ¹ is an alkyl group or alkenyl group having 6 to 18 carbon atoms, preferably an alkyl group having 6 to 18 carbon atoms, and more preferably an alkyl group having 10 to 13 carbon atoms. The following reasons can be considered as the reason why the number of carbon atoms should be 6-18, but it should be noted that the present invention is not limited by these reasons. First, if the number of carbon atoms is less than 6, the oily part protecting the metal powder pigment is shortened, and therefore the ability to protect the metal powder pigment is considered to be reduced. When the number of carbon atoms exceeds 18, it is considered that the molecular bulk is so large that it is difficult to adsorb on the surface of the metal powder pigment. R ¹ may be either linear or branched, and is preferably linear. When R ¹ is linear, the steric hindrance of the phosphate ester compound is reduced, collisions are unlikely to occur, and the surface of the metal powder pigment can be protected more densely and water resistance can be improved. Specific examples of R ¹ include octyl, decyl, tridecyl, lauryl, cetyl, stearyl, oleyl, and hexadecyl, and lauryl is particularly preferable as R ¹ .

R ² is hydrogen or R ³ (OCH ₂ CH ₂ ) _n . When R ² is hydrogen, the compound of the chemical formula (1) is a monoester, and when R ² is R ³ (OCH ₂ CH ₂ ) _n , the compound of the chemical formula (1) is a diester. When R ² is R ³ (OCH ₂ CH ₂ ) _n , R ¹ and R ³ may be the same or different. Preferred embodiments and the number of carbon atoms, etc. R ³ is, because as has been described in connection with the earlier R ^1, description thereof is omitted.

  In chemical formula (1), n is an integer of 0-3. When n is 0, the compound is an alkyl or alkenyl phosphate compound. When n is 1 to 3, the compound is an ester compound obtained by adding ethylene oxide to an alkyl group or alkenyl group. When n exceeds 3, the distance between the metal powder pigment and the alkyl group or alkenyl group becomes large, and it becomes difficult to obtain a sufficient water resistance improvement effect by the phosphate ester compound. n is preferably 2 or less, more preferably 1-2.

In the present invention, as the phosphate ester compound represented by the chemical formula (1), two or more different R ¹ compounds may be mixed and used, or a mixture of monoester and diester may be used. Generally, the phosphate ester compound represented by the chemical formula (1) is obtained as a mixture of a monoester and a diester.

In the present invention, a salt that is a neutralized product of the phosphate compound represented by the chemical formula (1) and a base may be used. This is because the salt of the phosphate ester compound is easily dissolved during production. The cation forming a pair with the oxygen atom of phosphoric acid is not particularly limited, and may be, for example, metal ions such as sodium ion, potassium ion and magnesium ion, ammonium ion, and organic base ion. The cation may be a monovalent cation or may be a divalent cation. The cation is preferably a sodium ion or a potassium ion because of easy ion dissociation. In the compound represented by the chemical formula (1), when R ² is R ³ (OCH ₂ CH ₂ ) _n , the salt becomes a dialkyl phosphate salt, and when R ² is hydrogen, The salt becomes a monoalkyl phosphate ester salt. The salt of a phosphate ester compound can be obtained, for example, by neutralizing a phosphate ester compound with sodium hydroxide or triethanolamine.

More specifically, the phosphate ester compound that can be used in the present invention is “phosphanol ML-220” (R ¹ = R ³ = C ₁₂ H ₂₅ , n = 2, mono (R ² = H): Di (R ² = R ³ (OCH ₂ CH ₂ ) _n ) = 7: 3, HLB = 12.5), “phosphanol ML-200” (R ¹ = R ³ = C ₁₂ H ₂₅ , n = 0 , Mono: di = 7: 3, HLB = 10.0), “phosphanol SM-172” (R ¹ = R ³ = C ₈ H ₁₇ , n = 0, mono: di = 1: 1, HLB = 10.5), “phosphanol ED-200” (R ¹ = R ³ = C ₈ H ₁₇ , n = 1, mono: di = 1: 1, HLB = 11.4), “phosphanol RL— 210 "(R ¹ = R ³ = C ₁₈ H ₃₇ , n = 2, mono: di = 1: 1, HLB = 5.4 ), “Phosphanol RS-410” (R ¹ = R ³ = C ₁₃ H ₂₇ , n = 3, mono: di = 1: 1, HLB = 9.0), “phosphanol GF-339 (R ¹ = R ³ = mixture of C ₆ H _{13 to} C ₁₀ H ₂₁ , n = 0, mono: di = 1: 1, HLB = 10.0), “phosphanol GF-199” (R ¹ = R ³ = C ₁₂ H ₂₅ , n = 0, mono: di = 1: 1, HLB = 5.5), “phosphanol GF-185” (R ¹ = R ³ = C ₁₃ H ₂₇ , n = 0, mono : Di = 1: 1, HLB = 5.2), “Phosphanol RL-310” (R ¹ = R ³ = C ₁₈ H ₃₇ , n = 3, mono: di = 1: 1, HLB = 5. 7) (or, Toho Chemical Industry Co., Ltd.), "Nikkol DDP-2" _{^{(R 1 = R 3 = C}} 12 H 25 ~C 15 Mixture of _{31, n = 2, HLB =} 6.5) ( or, Nikko Chemicals Co., a Ltd.) and their salts. In particular, “phosphanol ML-220” and / or a salt thereof is preferably used.

  The aqueous ink composition of the present invention preferably contains 0.01 mass% to 2.0 mass%, preferably 0.01 mass% to 1.0 mass%, of the phosphate ester compound represented by the chemical formula (1). It is more preferable, and it is still more preferable to contain 0.02 mass%-0.5 mass%. When a salt of a phosphate ester compound represented by the chemical formula (1) is included, the ratio of the salt is preferably within the above range, or when both the salt and the phosphate ester compound are included, It is preferable that the ratio of the mass of the total is within the above range. Therefore, when an ink composition is produced as the aqueous solution of the phosphoric acid ester compound represented by the chemical formula (1) and / or its salt, for example, the amount of the phosphoric acid ester compound and water contained in the entire ink is taken into consideration. Then, the input amount of the aqueous solution is adjusted.

  The reason why the discoloration and the generation of hydrogen gas due to the reaction between the metal powder pigment and water are suppressed by including the specific phosphate ester compound in the ink composition according to the present invention is as follows. Can be considered. Usually, in a metal powder pigment, the metal powder exists in a state of being overlapped as scale-like particles. In the production of the water-based ink composition, usually, with stirring, the metal powder pigment has been subjected to a water-resistant treatment in advance such that the particles that overlap each other are separated or the particles are cracked during the stirring. Even if it exists, it is thought that the surface which is not water-resistant processed may be exposed. When such a surface is exposed, water resistance is lowered, and the above-described problems are considered to occur. The specific phosphate ester compound is presumed to effectively impart water resistance to the newly exposed surface that has not been subjected to the water resistance treatment. However, this assumption does not affect the present invention.

(Metal powder pigment)
The metal powder pigment is not particularly limited as long as it has a metallic luster, and for example, an aluminum pigment, a brass pigment, or the like can be used. Examples of the aluminum pigment include “Alpaste WJP-U75C”, “Alpaste WE1200”, “Alpaste WXM7675”, “Alpaste WXM0630”, “Alpaste WXM0650”, “Alpaste WXM0620” (above, Toyo Aluminum ( Co., Ltd.), “1110W”, “2172SW” (manufactured by Showa Aluminum Powder Co., Ltd.), “aluminum paste AW”, “aluminum paste FW” (manufactured by Asahi Kasei Chemicals Corporation), and the like. Further, colored aluminum pigments such as “F500RG-W”, “F500BG-W”, “F701GR-W”, “F701RE-W” (manufactured by Showa Aluminum Powder Co., Ltd.) can also be used. The aluminum pigment may be a leafing type or a non-leafing type.

  Examples of brass pigments include “BS-605”, “BS-607” (above, Toyo Aluminum Co., Ltd.), “Bronze Powder P-555”, “Bronze Powder P-777” (above, Nakajima Metal Foil Powder). Kogyo Co., Ltd.).

  As the metal powder pigment, only one kind of the exemplified pigments may be used, or two or more kinds may be used in combination. The average particle diameter of the metal powder pigment can be appropriately selected according to the type of the pigment, and is usually about 5 to 50 μm.

  In the present invention, a metal powder pigment that has been subjected to water resistance treatment in advance may be used. The water resistance treatment can be performed by a known method. For example, the water resistance treatment can be performed using a phosphoric acid-containing solution. Water-resistant metal powder pigments are also commercially available, and such commercially available products may be used. Specifically, the above-mentioned “Alpaste WXM0650”, “Alpaste WXM0620” (both manufactured by Toyo Aluminum Co., Ltd.) and the like can be preferably used as the aluminum powder pigment subjected to water resistance treatment.

  The metal powder pigment is preferably contained in the water-based ink composition in an amount of 2 to 15% by mass, more preferably 1 to 10% by mass. If the content of the metal powder pigment is too small, when used as a writing instrument, the glitter of the handwriting is insufficient, and the concealing property is insufficient, and the metallic handwriting may not be obtained. When there is too much content of a metal powder pigment, solid content will increase, and when using it as a writing implement, the outflow property from a nib may fall, and also a nib may be clogged.

(water)
The water-based ink composition of the present invention contains water that functions as a dispersion medium and / or solvent for dispersing and / or dissolving the metal powder pigment and other components. As water, normally used water, for example, ion-exchanged water and distilled water can be used. The water content is not particularly limited, and is appropriately selected according to the content of the metal powder pigment and other components and the viscosity to be obtained. For example, the content of water may be in the range of 1% by mass to 80% by mass, and preferably about 20% by mass to 70% by mass.

  The water-based ink composition of the present invention may contain commonly used components in addition to the metal powder pigment and water. Hereinafter, components that are usually used will be described.

(Thickener)
The water-based ink composition of the present invention may contain a thickener for imparting a desired viscosity to the ink and ensuring dispersion of the metal powder pigment. As a thickener, for example
-Microbial polysaccharides or derivatives thereof such as pullulan, welan gum, xanthan gum (or xanthan gum), leozan and rhamzan gum;
-Guar gum, locust bean gum, pectin, etc., which are water-soluble plant polysaccharides or derivatives thereof;
-Gelatin and casein, which are water-soluble animal polysaccharides or derivatives thereof;
-Cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose (CMC) and sodium and ammonium salts of celluloses such as hydroxypropyl cellulose;
Starchy derivatives, such as starch, cationic starch, dextrin, modified dextrin, and sodium starch glycolate;
-Vinyl-based synthetic polymers such as polyvinyl alcohol (PVA), polyvinyl pyrrolidone, and polyvinyl ether;
-Acrylic synthetic polymers such as sodium polyacrylate and carboxyvinyl polymer;
-Other synthetic polymers such as polyethylene oxide and methoxyethylene maleic acid copolymer can be exemplified. The water-based ink composition may contain one or more thickeners selected from these.

  The water-based ink composition of the present invention contains a thickener, preferably 0.15% by mass to 0.50% by mass, more preferably 0.20% by mass to 0.40% by mass. When there is too little content of a thickener, the dispersibility of a metal powder pigment will fall and a metal powder pigment may precipitate. When there is too much content of a thickener, the viscosity of an ink composition will become high, and when using it as a writing implement, the outflow property from a pen tip may fall.

(Coloring agent)
The water-based ink composition of the present invention may contain a colorant. The colorant is not particularly limited as long as it is well dissolved or dispersed in the water-based ink composition, and may be either a dye or a pigment. The same applies when the water-based ink composition is a double color ink composition. The dye as the colorant may be, for example, a water-soluble dye. The pigment as the colorant may be an inorganic pigment or an organic pigment. Specifically, as the colorant, for example, pigments (for example, titanium oxide, zinc white, carbon black, copper phthalocyanine, selenium, azo, quinacridone, anthraquinone, dioxane, indigo, thioindigo, perinone , Perylene, isoindolenone, azomethine pigments, fluorescent pigments, ethylene bismelamine, and ethylene bismelamine derivatives), dyes (anthraquinone dyes, methine dyes, carbonium dyes, and metal complex dyes) Etc.), or a colorant obtained by coloring a plastic pigment with a pigment or dye. You may use a coloring agent individually or in combination of 2 or more types. In addition, brighteners, such as glass flakes and pearl pigments, may be used with or in addition to the colorant.

  When the water-based ink composition of the present invention contains a colorant, it preferably contains 0.05% by mass to 15% by mass, and more preferably 1-10% by mass. If the content of the colorant is too small, for example, in the case of a double color ink composition, a sufficient double color effect may not be obtained. May not be enough. If the content of the colorant is too large, the flowability and viscosity may be adversely affected. However, the content of the colorant is not limited to these ranges, and may be appropriately selected according to the type of the colorant to be used. When the water-based ink composition of the present invention contains a brightening agent, the amount of the brightening agent is not particularly limited, but may be, for example, 0.5% by mass to 20% by mass.

(Water-soluble organic solvent)
The water-based ink composition of the present invention may contain a water-soluble organic solvent. A water-soluble organic solvent is added to prevent drying at the nib and to prevent freezing of the ink. In particular, in the case of a dual color ink composition, it is used to increase the dye penetration effect. . Specifically, the water-soluble organic solvent includes, for example, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and polyethylene glycol, polyhydric alcohols such as glycerin, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, And glycol ethers such as dipropylene glycol monomethyl ether and dipropylene glycol monopropyl ether. These organic solvents may be used alone or in combination of two or more.

  The content of the water-soluble organic solvent is not particularly limited, and is appropriately selected according to the type of the water-soluble organic solvent. For example, the content of the water-soluble organic solvent may be in the range of 1% by mass to 50% by mass, and preferably about 5% by mass to 30% by mass. If the content of the water-soluble organic solvent is too small, the ink composition tends to dry, and when it is used as a writing instrument, clogging may occur and the writing property may be deteriorated, and a good double coloring effect is obtained. It may not be possible. When there is too much content of the water-soluble organic solvent, a handwriting or a coating film will become difficult to dry.

(Other ingredients)
The water-based ink composition of the present invention may contain components other than the above as necessary. Specifically, polyoxyethylene alkali metal salt, dicarboxylic acid amide, N-oleyl sarcosine salt or the like may be added as a lubricant, and polyhydric alcohol or a derivative thereof (such as glycerin) is added as a wetting agent. Benzotriazole, tolyltriazole, or dicyclohexylammonium nitrate may be added as a rust inhibitor, and benzoisothiazoline compounds, pentachlorophenol compounds, cresol, etc. may be added as antiseptic / rust inhibitors. As an antifungal agent, methyl paraoxybenzoate and Amorden HS (trade name, manufactured by Daiwa Chemical Industry Co., Ltd.) may be added. In addition, various dispersants (for example, water-soluble acrylic resin, water-soluble maleic acid resin, water-soluble styrene-acrylic copolymer, water-soluble styrene-maleic acid copolymer), antifoaming agent, leveling agent, anti-aggregation agent , PH adjusting agents, and surfactants may be added.

  The viscosity of the water-based ink composition of the present invention is not particularly limited, and for example, it may have a viscosity of 1000 mPa · s to 10000 mPa · s. Here, the viscosity of the water-based ink composition is shown as a value measured under the condition of 3 ° (R14) cone rotation number 0.5 rpm (20 ° C.) using an ELD type viscometer. By setting the viscosity within this range, a writing instrument having excellent writing properties and stability over time can be provided, for example, in the form of a ballpoint pen. The viscosity can be adjusted with a thickener and water.

  The water-based ink composition of the present invention is preferably used as ink for various writing instruments. The writing instrument is preferably in the form of a core-type writing instrument such as a marker and a sign pen, or a ballpoint pen, which allows ink to ooze from the pen tip, and more preferably a ballpoint pen. A ballpoint pen is a writing instrument in which an ink storage tube loaded with ink is provided in a shaft, and ink is drawn out from a pen tip on which a small sphere is attached. The center-type writing instrument has a center core in which the fiber bundle is converged as an ink containing portion, and a pen tip (tip) for discharging the ink stored in the center core. As the tip, for example, a ball, fiber, plastic It is a writing instrument provided with a lead, a brush-like object, or a brush-like object.

  The writing instrument can be assembled using known members. For example, a ballpoint pen can be manufactured by loading ink into an ink containing tube formed of a known material and having a known size and assembling it with a known structure of a ballpoint pen tip of a known structure made of a known material. The ink storage tube is, for example, a synthetic resin pipe such as polyethylene and polypropylene, or a metal pipe. The ballpoint pen tip may be a normal one, and a difference between the ball diameter and the ball house inner diameter of, for example, 0.01 mm or more can be used. When a double color ink composition is used as the ink, it is preferable to use a ballpoint pen tip having a difference of 0.03 mm or more, particularly 0.03 mm to 0.04 mm. By increasing the difference between the ball diameter and the ball house inner diameter to be 0.03 mm or more, a good double coloring effect can be obtained.

  The core-type writing instrument can be prepared by preparing a core (ink containing portion) in which the fiber bundles are converged, filling the ink, and assembling it together with the pen tip by a known assembly method.

Next, the manufacturing method of the water-based ink composition of this invention is demonstrated. The production method of the present invention comprises:
Dispersing at least one phosphate ester compound selected from the phosphate ester compound represented by the chemical formula (1) and a salt thereof in water;
Dispersing the metal powder pigment in water in which the phosphate ester compound is dispersed, and dispersing other components in water in which the phosphate ester compound and the metal powder pigment are dispersed. In the production method of the present invention, it is important to disperse the phosphate ester compound, the metal powder pigment, and other components in water according to the above order. As long as this order is followed, the dispersion, demolding and filtration can be carried out using conventional methods. For example, components other than the metal powder pigment may be added at once or sequentially.

  The dispersion of the phosphate ester compound may be carried out by dispersing an aqueous solution in which the phosphate ester compound is dissolved in water. In that case, in the finally obtained water-based ink composition, it is necessary to adjust the concentration of the aqueous solution and the addition amount of the aqueous solution so that the content of the phosphoric ester compound and the content of water are as desired. .

  In the production method of the present invention, it is preferable to carry out the stirring for about 30 minutes to 2 hours after the metal powder pigment is added to the water in which the phosphate ester compound is dispersed. By stirring for this amount of time, the phosphate ester compound can be sufficiently adhered to the surface of the metal powder pigment to be dispersed, thereby imparting water resistance.

  You may implement the manufacturing method of the said invention as a water-resistant processing method of the metal powder pigment contained in a water-based ink composition. That is, when the metal powder pigment is contained in the water-based ink composition, it may be carried out in order to improve the water resistance when it does not exhibit sufficient water resistance.

The following were prepared as components constituting the water-based ink composition.
(Metal powder pigment)
Metal powder pigment 1:
“Alpaste WXM0650” (manufactured by Toyo Aluminum Co., Ltd.)
Leafing type, average particle size 7μm,
Aluminum powder about 60-80% by mass
Metal powder pigment 2:
“Alpaste WXM0620” (manufactured by Toyo Aluminum Co., Ltd.)
Leafing type, average particle size 15μm,
Aluminum powder about 60-80% by mass

(Phosphate compound)
-Phosphate ester compound 1:
Phosphanol ML-220 "(manufactured by Toho Chemical Industry Co., Ltd.)
R ¹ = R ³ = C ₁₂ H ₂₅ , n = 2, mono: di = 7: 3, HLB = 12.5
-Phosphate ester compound 2:
“Phosphanol SM-172” (manufactured by Toho Chemical Co., Ltd.)
R ¹ = R ³ = C ₈ H ₁₇ , n = 0, mono: di = 1: 1, HLB = 10.5
-Phosphate ester compound 3:
“Phosphanol GF-199” (manufactured by Toho Chemical Industry Co., Ltd.)
R ¹ = R ³ = C ₁₂ H ₂₅ , n = 0, mono: di = 1: 1, HLB = 5.5

-Phosphate ester compound 4:
"Phosphanol ED-200" (manufactured by Toho Chemical Industry Co., Ltd.)
R ¹ = R ³ = C ₈ H ₁₇ , n = 1, mono: di = 1: 1, HLB = 11.4
-Phosphate ester compound 5:
“Phosphanol RS-410” (manufactured by Toho Chemical Co., Ltd.)
R ¹ = R ³ = C ₁₃ H ₂₇ , n = 3, mono: di = 1: 1, HLB = 9.0
-Phosphate ester compound 6:
Nikkor DLP-10 (manufactured by Nikko Chemicals)
Diester compound of R ¹ = R ³ = C ₁₂ H ₂₅ , n = 10, HLB = 17.0

-Phosphate ester compound 7:
Nikkor DDP-6 (manufactured by Nikko Chemicals)
R ¹ = R ³ = C ₁₂ H _{25 to} C ₁₅ H ₃₁ , n = 6, HLB = 9.0
* R ¹ = R ³ is a mixture of C ₁₂ H ₂₅ , C ₁₃ H _27, C ₁₄ H ₂₉ , C ₁₅ H _31. Phosphate ester compound 8:
"Nikkor TDP-10" (manufactured by Nikko Chemicals)
Mixture of triester compounds of C ₁₂ H ₂₅ O (CH ₂ CH ₂ O) _{10 to} C ₁₅ H ₃₁ O (CH ₂ CH ₂ O) ₁₀ , HLB = 14.0
-Phosphate ester compound 9:
“Phosphanol PE-510” (manufactured by Toho Chemical Co., Ltd.)
R ¹ = R ³ = phenol, n = 0, mono: di = 1: 1
-Phosphate ester compound 10:
“Phosphanol RD-720” (manufactured by Toho Chemical Industry Co., Ltd.)
R ¹ = R ³ = C ₁₈ H ₃₇ , n = 7, mono: di = 1: 1, HLB = 14.4
-Phosphate ester compound 11:
“Phosphanol GB-520” (manufactured by Toho Chemical Industry Co., Ltd.)
R ¹ = R ³ = C ₁₈ H ₃₇ , n = 7, mono: di = 1: 1, HLB = 6.9

(Coloring agent)
・ Colorant 1: ACID YELLOW 73 (Hodogaya Chemical Co., Ltd., trade name “Uraninkonk”)
-Colorant 2: ACID RED 289 (Daiwa Kasei Co., Ltd.)
Colorant 3: ACID BLUE 104 (Daiwa Kasei Co., Ltd., trade name “ACID BLUE PI CONC”)
-Colorant 4: ACID GREEN 16 (Daiwa Kasei Co., Ltd.)
-Colorant 5: Pigment Red (Dainippon Ink Chemical Co., Ltd., “Shimra First Red 4127”)

(Pigment dispersant)
・ Product name "John Krill" (Johnson Polymer Co., Ltd., acrylic vinyl acetate emulsion)
(Thickener)
・ Product name "K7C233" (Ranzan gum, manufactured by Sanki Co., Ltd.)

(Anti-mold agent)
・ Product name "Coat Side H", manufactured by Nippon Enviro Chemicals Co., Ltd.
(Preservative)
Benzoisothiazolin-3-one (trade name “Proxel XL-2”, manufactured by Arch Chemicals)

(Organic solvent)
Organic solvent 1: “Dauanol DPNP” (Dow Chemical Japan Co., Ltd., dipropylene glycol n-propyl ether)
・ Organic solvent 2: “Dowanol DPM” (manufactured by Dow Chemical Japan Co., Ltd., dipropylene glycol methyl ether)
・ Organic solvent 3: Glycerin ・ Organic solvent 4: Ethylene glycol

(Rust inhibitor)
Benzotriazole (BTA)
(PH adjuster)
Triethanolamine

  Using the above components, aqueous ink compositions for double color development having the compositions shown in Tables 1 and 2 were produced. First, a phosphoric acid ester compound aqueous solution (10% aqueous solution) was dispersed in ion-exchanged water in a predetermined amount of water. Next, the metal powder pigment was added and stirred at room temperature (about 20 ° C.) for 1 hour. Then, the remaining components were added, and the mixture was further stirred at room temperature (about 20 ° C.) for 1 hour.

  Examples 1 to 3 are examples in which the type of the colorant is changed. Example 4 is an example in which the type of solvent infiltrated with the colorant is changed for double color development. Examples 6-9 are the examples which changed the kind of phosphate ester compound. Example 10 is an example in which no pH adjuster is added. Example 11 is an example using a pigment as a colorant. Comparative Examples 1-6 are the examples which changed the kind of phosphate ester compound.

The obtained water-based ink composition was put into a polypropylene bottle, stoppered, and stored at 70 ° C. After storage, the appearance of the bottle was observed, and the ink composition was further dropped onto a filter paper, and the change in hue and the like were visually observed and evaluated according to the following criteria.
○: Dye discoloration, discoloration of aluminum powder pigment, and ink ejection are not observed even when stored at 70 ° C. for 1 week.
Δ: From 2 days to 1 week after the start of storage at 70 ° C., slight dye decolorization, discoloration of the aluminum powder pigment, and ink ejection were slightly observed.
X: After storage at 70 ° C. for 1 day, any of decolorization of the dye, discoloration of the aluminum powder pigment, and ejection of the ink was observed.

  In each of Examples 1 to 11, even when exposed to high temperatures, the aluminum powder pigment and water did not react or even reacted slightly, and showed good storage stability. On the other hand, Comparative Examples 1 to 6 using a phosphate ester compound or triester in which the number of n was more than 3 had low storage stability.

  The water-based ink composition of the present invention has excellent storage stability and is useful as various writing instruments or printing inks that give a metallic handwriting or coating film.

Claims (2)

An ink composition comprising at least a metal powder pigment and water, wherein at least one phosphate ester compound selected from a phosphate ester compound represented by the following chemical formula (1) and a salt thereof , or a mixture thereof : A water-based ink composition comprising a metal powder pigment that has been subjected to water resistance treatment in advance.

(In the formula, ^{R 1} is an alkyl group of 12 carbon atoms, ^{R 2} is hydrogen or _{^{R 3 (OCH 2 CH 2)}} n (R 3 is a is) alkyl group having 12 carbon atoms, n Is 0-3) Dispersing at least one phosphate ester compound selected from a phosphate ester compound represented by the chemical formula (1) and a salt thereof in water;
Dispersing a metal powder pigment that has been previously treated with water resistance in water in which the phosphoric ester compound is dispersed, and other components in water in which the phosphoric ester compound and the metal powder pigment are dispersed. A method for producing a water-based ink composition, comprising dispersing.

(In the formula, ^{R 1} is an alkyl group of 12 carbon atoms, ^{R 2} is hydrogen or _{^{R 3 (OCH 2 CH 2)}} n (R 3 is a is) alkyl group having 12 carbon atoms, n Is 0-3)