Coloring composition and coloring method

Abstract

To provide a coloring composition good in water resistance of a metal pigment and dispersibility of the metal pigment and capable of giving a colored material good in metallic luster.SOLUTION: An aqueous coloring composition contains a metal pigment, water, and an organic solvent. The metal pigment is metal particles surface-treated with a compound represented by formula (1) or formula (2). The organic solvent contains an organic solvent (A) having a water solubility at 20°C of 1,000 g / L or more and an organic solvent (B) having a water solubility at 20°C of 100 g / L or less. (R1-)P(O)(OH)2 (1) and (R2-O-)aP(O)(OH)3-a (2) (where R1 and R2 each independently represent a C12 or higher hydrocarbon group which may be substituted with one or more substituents; and a represents 1 or 2).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a coloring composition, a coloring method, and a pigment dispersion. [Background technology]

[0002] Compositions such as inks and paints containing metal pigments such as aluminum have been developed for the production of articles with a metallic luster. In recent years, from the viewpoints of global environmental friendliness and ease of handling, aqueous compositions containing water as the main solvent have been preferred over non-aqueous compositions containing organic solvents as the main solvent in the development of compositions.

[0003] For example, Patent Document 1 discloses a water-based metallic ink using an aluminum pigment. The aluminum pigment disclosed in Patent Document 1 is surface-treated with a fluorine-based treatment agent to prevent the metallic luster from decreasing in water. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-140359 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the metallic pigments in water-based metallic inks still have insufficient water resistance, and there are problems in that the surface condition changes due to oxidation that progresses over time in the aqueous medium, resulting in a loss of dispersion stability and brilliance.

[0006] Therefore, there is a demand for a coloring composition that provides metal pigments with good water resistance and dispersion stability and that can give colored products with excellent metallic luster. [Means for solving the problem]

[0007] One aspect of the coloring composition according to the present invention is The coloring composition is a water-based coloring composition, Contains a metal pigment, water, and an organic solvent, The metal pigment is a metal particle whose surface has been treated with a compound represented by formula (1) or formula (2), The organic solvents include an organic solvent (A) having a water solubility of 1000 g / L or more at 20°C and an organic solvent (B) having a water solubility of 100 g / L or less at 20°C. (R 1 -)P(O)(OH)2···(1) (R 2 -O-) a P(O)(OH) 3-a ···(2) (In the formula, R 1 , R 2 each independently represents a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents, and a represents 1 or 2.

[0008] One aspect of the coloring method according to the present invention is to The method includes a step of applying the coloring composition to an object to be colored.

[0009] The pigment dispersion according to the present invention comprises: The pigment dispersion used in the preparation of any of the above coloring compositions contains the metal pigment, water, the organic solvent (A), and the organic solvent (B). DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes embodiments of the present invention. The embodiments described below are examples of the present invention. The present invention is not limited to the following embodiments, and includes various modified forms that are implemented within the scope of the present invention. Note that not all of the configurations described below are necessarily essential configurations of the present invention.

[0011] In this specification, "(meth)acrylic" refers to acrylic or methacrylic, and "(meth)acrylate" refers to acrylate or methacrylate. In addition, a "coloring composition" may also be referred to as a "composition," and a coloring composition may also be referred to as an "ink composition" or "ink."

[0012] 1. Coloring composition The coloring composition according to the present embodiment contains a metal pigment, water, and an organic solvent. The coloring composition is a composition that is applied to an object to be colored and used to color the object. Examples of the coloring composition include, but are not limited to, ink and paint.

[0013] Conventionally, metallic pigments in aqueous coloring compositions have had problems such as insufficient water resistance and changes in surface condition due to oxidation that progresses over time in an aqueous medium, resulting in impaired dispersion stability and glitter. Furthermore, when treating the surface of a metallic pigment, oxidation of the metallic pigment may progress during the treatment, resulting in a decrease in gloss and a tendency for the metallic pigment to aggregate. The aqueous coloring composition of the present embodiment provides excellent water resistance, dispersion stability, and glitter.

[0014] 1.1.Metallic pigments The metal pigment is a metal particle whose surface has been treated with a surface treatment agent. More specifically, the metal pigment includes an embodiment in which the surface treatment agent is attached to the surface of the metal particle by chemical bonding or physical adsorption.

[0015] 1.1.1. Metal particles The metal particles are composed of a metal material in at least a portion of the visible portion thereof, for example, the entire portion or the vicinity of the outer surface thereof, and have the function of imparting metallic luster to a colored product produced using the coloring composition.

[0016] The metal particles may be any particles as long as the region, including the surface area, is made of a metal material. For example, the entire particles may be made of a metal material, or the particles may have a base made of a non-metallic material and a coating made of a metal material that covers the base. Furthermore, the metal particles may have a passive film, such as an oxide film, formed on their surface. Even with such metal particles, problems such as water resistance and metallic luster have traditionally arisen. However, the coloring composition of the present embodiment can provide excellent water resistance, metallic luster, and other effects.

[0017] The metal material constituting the metal particles can be a single metal or various alloys. Examples include aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, iron, copper, and alloys containing at least one of these metals. Of these, the metal particles are preferably made of aluminum or an aluminum alloy, and more preferably aluminum. One reason aluminum and aluminum alloys are preferred is that they have a lower specific gravity than metals such as iron. This allows the metal pigment dispersed in the ink to settle very slowly, which tends to prevent uneven concentration and allow the composition to be stored for a longer period of time. Furthermore, a metal pigment containing aluminum or aluminum alloy particles can further enhance the gloss and luxurious feel of a colored product produced using the coloring composition while suppressing increases in production costs.

[0018] Among various metal materials, aluminum and aluminum alloys inherently exhibit superior glossiness. However, when particles made of these materials are used in a composition, the following problems may arise. Specifically, the storage stability (water resistance) of the composition is likely to be low, and when the composition is used as an inkjet composition, problems such as decreased ejection stability due to increased viscosity caused by gelation are likely to occur. In contrast, even when the metal pigment uses metal particles made of aluminum or an aluminum alloy, these problems can be reduced by surface-treating the metal particles with a specific surface treatment agent described below in this embodiment. Specifically, when the metal particles are aluminum or an aluminum alloy, the effects of the composition of this embodiment become more pronounced.

[0019] The metal particles may be of any shape, such as spherical, spindle-shaped, or needle-shaped, but are preferably scaly. This allows the main surfaces of the metal particles to be easily arranged on the object to which the composition is applied so as to conform to the surface shape of the object. As a result, the glossiness and other properties of the metal material constituting the metal particles can be more effectively exhibited in the resulting colored body, thereby providing the colored body with excellent glossiness and a luxurious feel. Furthermore, when the metal particles are scaly, the colored body also tends to have excellent abrasion resistance.

[0020] In this specification, the term "scale-like" refers to a shape such as a flat plate or curved plate, in which the area when viewed from a predetermined angle, for example, when viewed in a plan view, is larger than the area when viewed from an angle perpendicular to the viewing direction. In particular, when viewed from a direction in which the projected area is largest, i.e., the area S1 [μm 2 ] and the area S0 [μm 2The ratio S1 / S0 to S1 / S0 is preferably 2 or more, more preferably 5 or more, and even more preferably 8 or more. It is further preferably 10 or more, and even more preferably 20 or more. It is further preferably 30 or more. There is no particular upper limit for S1 / S0, but it is preferably 1000 or less, more preferably 500 or less, and even more preferably 100 or less. It is further preferably 80 or less.

[0021] For example, 50 random particles may be observed, and the average value calculated for these particles may be used as this value. Observation may be performed using, for example, an electron microscope, an atomic force microscope, or the like. Alternatively, the volume average particle diameter (D50) and the average thickness, which will be described later, may be used, and the units may be unified to obtain the volume average particle diameter (D50) / average thickness, which may then be used to define the above-mentioned range.

[0022] When the metal particles are scaly, the average thickness of the metal particles is preferably 5 nm or more and 90 nm or less. The lower limit of the average thickness of the metal particles is not particularly limited, but is more preferably 10 nm or more, and even more preferably 15 nm or more. When the metal particles are scaly, the upper limit of the average thickness of the metal particles is not particularly limited, but is more preferably 70 nm or less, even more preferably 50 nm or less, particularly preferably 30 nm or less, more particularly preferably 20 nm or less, and even more particularly preferably 15 nm or less.

[0023] When the metal particles are scaly and have an average thickness of 5 nm or more and 90 nm or less, preferably within the above range, the above-mentioned effect of the scaly particles becomes more pronounced.

[0024] The average thickness of metal particles can be measured using an atomic force microscope (AFM) in the same manner as the average thickness of metal pigments described below. For example, measurements are taken of 50 random metal particles using the atomic force microscope, and the average value is calculated. In other words, the average thickness is the arithmetic mean thickness.

[0025] The preferred range and measurement method for the volume average particle diameter (D50) of the metal particles can be the same as for the volume average particle diameter (D50) of the metal pigment, which will be described later. That is, the volume average particle diameter D50 is measured using a laser diffraction / scattering particle size distribution analyzer.

[0026] The metal particles may be produced by any method, but when they are made of aluminum, they are preferably obtained by forming an aluminum film by a vapor deposition method and then pulverizing the film. This method also reduces the variation in properties between particles. Furthermore, by using this method, even relatively thin metal particles can be suitably produced.

[0027] When producing metal particles using such a method, the metal particles can be suitably produced, for example, by forming a film made of aluminum on a substrate. The substrate can be, for example, a plastic film such as polyethylene terephthalate. The substrate may also have a release agent layer on the film-forming surface.

[0028] The pulverization is preferably carried out by applying ultrasonic vibrations to the film in a liquid, which makes it possible to easily obtain metal particles having the aforementioned particle diameter and to suppress variations in size, shape, and properties among the individual metal particles.

[0029] Furthermore, when grinding is performed by the above-described method, the liquid that can be suitably used may be alcohols, hydrocarbon compounds, ether compounds, or polar compounds such as propylene carbonate, γ-butyrolactone, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, cyclohexanone, acetonitrile, etc. Use of such a liquid can suppress undesired oxidation of the metal particles, while improving productivity of the metal particles and sufficiently reducing variations in size, shape, and properties among the individual particles.

[0030] 1.1.2.Surface treatment agents The metal pigment is a metal particle whose surface has been treated with a surface treatment agent represented by formula (1) or (2). The surface treatment agent used to treat the surface of the metal particle is a compound represented by the following general formula (1) or (2). (R 1 -)P(O)(OH)2···(1) (R 2 -O-) a P(O)(OH) 3-a ···(2) (In the formula, R 1 , R 2 each independently represents a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents, and a represents 1 or 2.

[0031] The compound represented by the above general formula (1) (substituted or unsubstituted alkyl phosphonic acid) is a compound in which the hydrogen atom of the phosphonic acid is (R 1 These compounds are substituted with alkyl groups. Because the steric hindrance caused by the alkyl moiety is small, they tend to be uniformly distributed on the surface of metal particles, improving the dispersion stability and gloss of the metal pigment.

[0032] The compound represented by the above general formula (2) is a compound in which one or two of the three hydroxyl groups of phosphoric acid are esterified with a substituted or unsubstituted alkyl group.

[0033] The compound represented by general formula (2) is a substituted or unsubstituted alkyl diester (di-form) when a is 1, and is a substituted or unsubstituted alkyl monoester (mono-form) when a is 2. When the compound represented by general formula (2) is a 1 (di-form), the steric hindrance caused by the presence of two substituted or unsubstituted alkyl moieties increases the effect of making it difficult for water to approach the metal particle surface, and the metal pigment tends to have better water resistance. Note that hereinafter, the "monoester" may be referred to as the "mono-form" and the "diester" may be referred to as the "di-form."

[0034] In the above formula, R 1 and R 2 is a divalent hydrocarbon group having a carbon skeleton with 12 or more carbon atoms. The carbon arrangement of the divalent hydrocarbon group may be linear, branched, or cyclic. Furthermore, the divalent hydrocarbon group may contain saturated or unsaturated bonds. Furthermore, the two bonding positions of the divalent hydrocarbon group are arbitrary.

[0035] R 1 , R 2 may be independently substituted with one or more substituents. For example, the substituent may be substituted with one or more of a carboxyl group, a hydroxyl group, an amino group, or an oxyalkylene-containing group. When R has a substituent, 1 or R 2 The dispersion stability of the metal pigment tends to be excellent when the carbon atom is bonded to the carbon atom that is farthest from P or O. Of these, the oxyalkylene-containing group is a group having an oxyalkylene structure, and the oxyalkylene structure is also called an alkylene oxide structure.

[0036] The oxyalkylene-containing group has one or more alkylene oxide units, and may have two or more. In particular, it may have a structure in which a plurality of alkylene oxide units are repeated. The number of repeating alkylene oxide units is preferably 10 or less, more preferably 4 or less. The lower limit is 1 or more, preferably 2 or more, more preferably 3 or more. The number of carbon atoms in the alkylene oxide unit is preferably 1 or more and 4 or less.

[0037] Examples of divalent hydrocarbon groups having a carbon skeleton with 12 or more carbon atoms include divalent saturated hydrocarbon groups having no double bonds or triple bonds between carbon atoms, and divalent unsaturated hydrocarbon groups having double bonds or triple bonds between carbon atoms. The divalent hydrocarbon group may be an aromatic hydrocarbon group whose carbon skeleton has an aromatic ring structure, or a chain or cyclic aliphatic hydrocarbon group. Chain aliphatic hydrocarbon groups are particularly preferred because of their superior dispersion stability. The aliphatic hydrocarbon group having a chain skeleton may be branched or linear, with linear types being preferred because of their superior dispersion stability, ejection stability, gloss, etc. 1 , R 2 is preferably a hydrocarbon group that is not substituted with a substituent, that is, an unsubstituted hydrocarbon group.

[0038] The compound represented by the general formula (1) and the compound represented by the general formula (2) are represented by R 1 , R 2 are each independently preferably a hydrocarbon group having from 14 to 32 carbon atoms, more preferably a hydrocarbon group having from 15 to 30 carbon atoms, even more preferably a hydrocarbon group having from 16 to 22 carbon atoms, and particularly preferably a hydrocarbon group having from 16 to 20 carbon atoms. By doing so, the dispersion stability and water resistance of the coloring composition become better, and even if sedimentation of the components occurs, the components can be more easily redispersed.

[0039] In addition, R in the above general formula (1) and the above general formula (2) 1 , R 2and preferably have the same number of carbon atoms, and more preferably are hydrocarbon groups with the same structure. This increases the tendency for the surface treatment agent to adhere uniformly to the metal particle surfaces, and makes it possible to achieve a more balanced and favorable water resistance and glossiness of the colored product.

[0040] Specific examples of the compound represented by the general formula (1) include dodecylphosphonic acid (laurylphosphonic acid), tetradecylphosphonic acid (myristylphosphonic acid), hexadecylphosphonic acid (cetylphosphonic acid), and octadecylphosphonic acid (stearylphosphonic acid), and one or more selected from these are preferred. More preferred are one or more selected from hexadecylphosphonic acid (cetylphosphonic acid) and octadecylphosphonic acid (stearylphosphonic acid), with octadecylphosphonic acid (stearylphosphonic acid) being even more preferred.

[0041] Specific examples of the mono-compound represented by the general formula (2) include monooctyl phosphate, monolauryl phosphate, monoisotridecyl phosphate, and monostearyl phosphate, and one or more selected from these are preferred. One or more selected from monoisotridecyl phosphate and monostearyl phosphate are more preferred, and monostearyl phosphate is even more preferred.

[0042] Specific examples of the di-isomer of the compound represented by the general formula (2) include dioctyl phosphate, dilauryl phosphate, diisotridecyl phosphate, and distearyl phosphate, and one or more selected from these are preferred. More preferred are one or more selected from diisotridecyl phosphate and distearyl phosphate, and even more preferred is distearyl phosphate.

[0043] Among the compounds represented by formula (2), compounds where a is 2, i.e., phosphate diesters (diesters), have two alkyl groups, and more alkyl groups can be introduced onto the surface of the metal particles, which increases the hydrophobicity of the pigment surface and improves the water resistance of the pigment.

[0044] It is more preferable that the surface treatment agent contains either a compound represented by formula (1) or a compound represented by formula (2) in which a is 2. This increases the tendency for the surface treatment agent to adhere uniformly to the surfaces of the metal particles, thereby achieving a better balance between water resistance and gloss.

[0045] The surface treatment agent is preferably present in an amount of 0.5% by mass to 60% by mass, preferably 1% by mass to 50% by mass, more preferably 5% by mass to 40% by mass, and even more preferably 20% by mass to 40% by mass, relative to the total mass (100% by mass) of the metal particles. With such a ratio, water resistance is improved and even if the components settle, the components can be more easily redispersed.

[0046] The mass of the surface treatment agent is the mass of the surface treatment agent contained in the coloring composition. When the surface treatment agent contained in the coloring composition is a surface treatment agent adhered to metal particles, the mass of the surface treatment agent is also the mass of the surface treatment agent adhered to the metal particles.

[0047] The coloring composition according to the present embodiment may contain a surface treatment agent other than the above-described surface treatment agent, as long as the effect of the present invention is not impaired. Examples of such surface treatment agents include fluorine-based compounds. As the fluorine-based compound, a compound containing fluorine and one or more elements selected from phosphorus, sulfur, and nitrogen as constituent elements can be preferably used. Specific examples of the fluorine-based compound include fluorine-based phosphonic acid, fluorine-based carboxylic acid, fluorine-based sulfonic acid, and salts thereof.

[0048] The surface treatment of metal particles with a surface treatment agent may be carried out, for example, by adding the surface treatment agent to a liquid when a metal film formed by a vapor phase deposition method is pulverized in the liquid to form metal particles.

[0049] 1.1.3.Volume average particle size The volume average particle diameter D50 of the metal pigment treated with the surface treatment agent is preferably 15 μm or less, and more preferably 200 nm or more. Furthermore, the volume average particle diameter D50 may be within the range described below.

[0050] The particle size of the metallic pigment in a coloring composition is appropriate depending on the application. For example, when the coloring composition is used as a paint, the volume average particle size D50 of the metallic pigment, in which the metal particles have been treated with a surface treatment agent, is preferably 15 μm or less, more preferably 10.0 μm or less, even more preferably 3 μm or more to 9 μm or less, and even more preferably 5 μm or more to 7 μm or less. When the coloring composition is used as a paint, using a metallic pigment with such particle size can provide a colored product with good water resistance, and a larger particle size can provide an even more excellent metallic luster. Moreover, the large particle size of the metallic pigment can provide a paint in which the components are easily redispersible, despite the tendency for sedimentation of the components.

[0051] On the other hand, for example, when the coloring composition is used as an inkjet ink, the volume average particle diameter D50 of the metal pigment in which the metal particles are treated with a surface treatment agent is preferably 2 μm or less, more preferably 1 μm or less, even more preferably 200 nm or more and 800 nm or less, and particularly preferably 300 nm or more and 500 nm or less.

[0052] When the coloring composition is used as an inkjet ink, clogging of nozzles during inkjet ejection can be further reduced if the particle size of the metallic pigment is within the above range. Furthermore, if the particle size of the metallic pigment is within the above range, good water resistance and sufficient dispersibility can be more easily obtained even if the specific surface area of ​​the metallic pigment is large.

[0053] The volume average particle diameter D50 of the metal pigment can be measured in the same manner as described in the section on metal particles.

[0054] 1.2.Water The coloring composition of this embodiment is an aqueous composition. That is, the coloring composition contains water. In this specification, a composition containing 20% ​​by mass or more of water in the liquid medium components is referred to as an aqueous composition. The water content of the liquid medium components is preferably 30% by mass or more and 100% by mass, more preferably 40% by mass or more and 90% by mass or less, and even more preferably 50% by mass or more and 80% by mass or less. The liquid medium is a solvent component such as water or an organic solvent.

[0055] The water content is preferably 20% by mass or more, more preferably 30% by mass or more and 99% by mass or less, even more preferably 40% by mass or more and 90% by mass or less, and even more preferably 50% by mass or more and 80% by mass or less, relative to 100% by mass of the coloring composition.

[0056] The water used is preferably pure water or ultrapure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, etc. In particular, water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is preferred because it can inhibit the growth of mold and bacteria for a long period of time.

[0057] 1.3.Organic Solvents The coloring composition according to the present embodiment contains an organic solvent (A) having a water solubility of 1000 g / L or more at 20° C. and an organic solvent (B) having a water solubility of 100 g / L or less at 20° C. The water solubility indicates the maximum mass of the organic solvent that does not separate or cause the entire liquid to become cloudy when the organic solvent is mixed with 1 L of water at 20° C.

[0058] Examples of the organic solvent (A) having a water solubility of 1000 g / L or more at 20°C include, but are not limited to, 1,2-hexanediol, propylene glycol, hexylene glycol, triethylene glycol monomethyl ether (TEGMME), propylene glycol monobutyl ether (PGMBE), ethyl lactate, propylene glycol monomethyl ether (PGMME), triethylene glycol, ethanol, and 3-methoxy-3-methylbutanol.

[0059] Examples of organic solvents (B) having a water solubility of 100 g / L or less at 20°C include, but are not limited to, 2-phenoxyethanol, 1-butanol, butyl lactate, 2-ethylhexanol, 2-butanol, etc. The water solubility of 1-butanol at 20°C is 70 g / L. Diethylene glycol diethyl ether (DEGDEE), butyl lactate, 2-ethylhexanol, and 2-butanol all have a water solubility of 0 g / L or less, but are miscible in the coloring composition due to their compatibility with organic solvent (A) and other solvents.

[0060] The organic solvent (A) and the organic solvent (B) are preferably selected from alkanediols, glycols, glycol ethers, monohydric alcohols, and esters. By selecting the organic solvent (A) and the organic solvent (B) in this manner, the dispersion stability of the metal pigment may be further improved.

[0061] The types of such organic solvent (A) and organic solvent (B) may be those described later in the organic solvent section, and among them, those that satisfy the water solubility of the organic solvent (A) or organic solvent (B) described above are organic solvent (A) or organic solvent (B).

[0062] The organic solvent (B) preferably has a water solubility of 70 g / L or less at 20°C, more preferably 50 g / L or less, even more preferably 30 g / L or less, and particularly preferably 10 g / L or less. The lower limit is 0 g / L or more. In an aqueous coloring composition, the organic solvent (B) may be dissolved in the solvent component due to the presence of the organic solvent (A), for example.

[0063] The organic solvent (B) is more preferably selected from aromatic monohydric alcohols and aliphatic monohydric alcohols having 4 or more carbon atoms. The aliphatic monohydric alcohols having 4 or more carbon atoms are preferably aliphatic monohydric alcohols having 4 to 10 carbon atoms, and more preferably aliphatic monohydric alcohols having 4 to 8 carbon atoms.

[0064] The aromatic monohydric alcohol is a monohydric alcohol having an aromatic ring, such as a benzene ring or a naphthalene ring. The aromatic monohydric alcohol may have an aromatic ring and an alkylene skeleton moiety to which a hydroxyl group is bonded. The alkylene skeleton moiety to which a hydroxyl group is bonded preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms.

[0065] Examples of such organic solvents (B) include, but are not limited to, 2-phenoxyethanol, benzyl alcohol, 1-butanol, 2-butanol, 2-ethylhexanol, etc. By selecting the organic solvent (B) in this way, the dispersion stability of the metal pigment may be further improved in some cases.

[0066] The content ratio (B / A) (mass ratio) of the organic solvent (A) to the organic solvent (B) is preferably 0.05 to 1.5, more preferably 0.1 to 1.2, even more preferably 0.1 to 0.9, and particularly preferably 0.1 to 0.5. A range of 0.15 to 0.4 is even more preferable. By keeping the content ratio (B / A) within this range, the dispersion stability of the metal pigment may be further improved.

[0067] Furthermore, the total content of organic solvent (A) and organic solvent (B) is preferably 8% by mass or more and 75% by mass or less, and more preferably 10 to 60% by mass. Furthermore, it is more preferably 15% by mass or more and 45% by mass or less, even more preferably 20% by mass or more and 42% by mass or less, even more preferably 20% by mass or more and 40% by mass or less, particularly preferably 25% by mass or more and 40% by mass or less, and particularly preferably 30% by mass or more and 40% by mass or less. By keeping the total content of organic solvent (A) and organic solvent (B) within this range, the dispersion stability of the metal pigment may be further improved.

[0068] It is more preferable that the content of organic solvent (A) is 5% by mass or more and 50% by mass or less, and / or the content of organic solvent (B) is 1% by mass or more and 30% by mass or less, based on the total amount of the composition. By setting the contents within these ranges, the dispersion stability of the metallic pigment may be further improved.

[0069] The content of organic solvent (A) is more preferably 10 to 45 mass%, further preferably 20 to 40 mass%, and particularly preferably 25 to 35 mass%, based on the total amount of the composition. The content of organic solvent (B) is more preferably 2 to 25 mass%, further preferably 3 to 20 mass%, particularly preferably 3 to 15 mass%, and even particularly preferably 4 to 10 mass%, based on the total amount of the composition.

[0070] 1.4.Other Ingredients The coloring composition may contain various substances such as those listed below, as long as the function is not impaired.

[0071] 1.4.1. Organic Solvents The coloring composition contains the organic solvents (A) and (B) and may contain other solvents (organic solvents) other than these. However, the content of solvents other than the organic solvent (A) or the organic solvent (B) is preferably small, and may not be contained at all.

[0072] The organic solvents will be described below. Among the organic solvents, those that satisfy the water solubility of the organic solvent (A) or the organic solvent (B) described above are organic solvent (A) or organic solvent (B), and those that do not satisfy the water solubility of the organic solvent (A) or the organic solvent (B) are other organic solvents.

[0073] Examples of such solvents include esters, alkylene glycol ethers, cyclic esters, nitrogen-containing solvents, alcohols, polyhydric alcohols, etc. Among these, there are organic solvents (A) and (B), and those having a water solubility of more than 100 g / L at 20°C and less than 1000 g / L at 20°C correspond to other organic solvents.

[0074] Examples of the nitrogen-containing solvent include cyclic amides and non-cyclic amides. Examples of the non-cyclic amides include alkoxyalkyl amides.

[0075] Examples of esters include glycol monoacetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and methoxybutyl acetate; Examples of glycol diesters include ethylene glycol diacetate, propylene glycol diacetate, dipropylene glycol diacetate, ethylene glycol acetate propionate, ethylene glycol acetate butyrate, diethylene glycol acetate butyrate, diethylene glycol acetate propionate, diethylene glycol acetate butyrate, propylene glycol acetate propionate, propylene glycol acetate butyrate, dipropylene glycol acetate butyrate, and dipropylene glycol acetate propionate.

[0076] The alkylene glycol ethers may be monoethers or diethers of alkylene glycol, and alkyl ethers are preferred. Specific examples include alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether; and ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and tripropylene glycol monobutyl ether. Examples of alkylene glycol dialkyl ethers include ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol methyl butyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol dimethyl ether.

[0077] Among the alkylene glycols, diethers tend to dissolve or swell the resin in the ink composition more easily than monoethers, and are therefore preferred in that they can further improve the abrasion resistance.

[0078] Examples of cyclic esters include cyclic esters (lactones) such as β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, β-butyrolactone, β-valerolactone, γ-valerolactone, β-hexanolactone, γ-hexanolactone, δ-hexanolactone, β-heptanolactone, γ-heptanolactone, δ-heptanolactone, ε-heptanolactone, γ-octanolactone, δ-octanolactone, ε-octanolactone, δ-nonalactone, ε-nonalactone, and ε-decanolactone, as well as compounds in which the hydrogen atom of the methylene group adjacent to the carbonyl group of these cyclic esters is substituted with an alkyl group having 1 to 4 carbon atoms.

[0079] Examples of alkoxyalkylamides include 3-methoxy-N,N-dimethylpropionamide, 3-methoxy-N,N-diethylpropionamide, 3-methoxy-N,N-methylethylpropionamide, 3-ethoxy-N,N-dimethylpropionamide, 3-ethoxy-N,N-diethylpropionamide, 3-ethoxy-N,N-methylethylpropionamide, 3-n-butoxy-N,N-dimethylpropionamide, 3-n-butoxy-N,N-diethylpropionamide, 3-n-butoxy-N,N-methylethylpropionamide, 3-n-propoxy-N,N-dimethylpropionamide, Examples include N-dimethylpropionamide, 3-n-propoxy-N,N-diethylpropionamide, 3-n-propoxy-N,N-methylethylpropionamide, 3-iso-propoxy-N,N-dimethylpropionamide, 3-iso-propoxy-N,N-diethylpropionamide, 3-iso-propoxy-N,N-methylethylpropionamide, 3-tert-butoxy-N,N-dimethylpropionamide, 3-tert-butoxy-N,N-diethylpropionamide, and 3-tert-butoxy-N,N-methylethylpropionamide.

[0080] Examples of cyclic amides include lactams, such as pyrrolidones such as 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, and 1-butyl-2-pyrrolidone, which are preferred in terms of accelerating the formation of a resin film, with 2-pyrrolidone being particularly preferred.

[0081] Examples of alcohols include compounds in which one hydrogen atom of an alkane has been substituted with a hydroxyl group. The alkane preferably has 10 or fewer carbon atoms, more preferably 6 or fewer carbon atoms, and even more preferably 3 or fewer carbon atoms. The alkane has 1 or more carbon atoms, preferably 2 or more carbon atoms. The alkane may be linear or branched. Examples of alcohols include n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol, benzyl alcohol, and phenoxypropanol.

[0082] When the coloring composition contains an alcohol, it is more preferable to select the alcohol from aromatic monohydric alcohols and aliphatic monohydric alcohols having 4 or more carbon atoms. This may improve the dispersion stability of the metal pigment. Aromatic monohydric alcohols and aliphatic monohydric alcohols having 4 or more carbon atoms have relatively strong hydrophobicity and good affinity with the surface treatment agent for the metal pigment, thereby improving the aqueous dispersibility of the particles. In other words, these alcohols can function to bridge the hydrophobicity and hydrophilicity between the hydrophobicity of the surface of the metal pigment and the water molecules used as the solvent.

[0083] The aliphatic monohydric alcohol having 4 or more carbon atoms is preferably an aliphatic monohydric alcohol having 4 to 10 carbon atoms, more preferably an aliphatic monohydric alcohol having 4 to 8 carbon atoms. The aromatic monohydric alcohol is a monohydric alcohol having an aromatic ring, and examples of the aromatic ring include a benzene ring and a naphthalene ring. In the aromatic monohydric alcohol, the number of carbon atoms in the alkylene skeleton portion to which a hydroxyl group is bonded is preferably 1 to 4, more preferably 1 to 3.

[0084] The content (total content) of aromatic monohydric alcohols and / or aliphatic monohydric alcohols having 4 or more carbon atoms is preferably 0.5% by mass or more, more preferably 1% by mass or more, and particularly preferably 3% by mass or more, relative to the total mass of the coloring composition. The content of aromatic monohydric alcohols and / or aliphatic monohydric alcohols having 4 or more carbon atoms is preferably 40% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less. The content of aromatic monohydric alcohols and / or aliphatic monohydric alcohols having 4 or more carbon atoms is preferably within the above range relative to the total mass of the liquid medium components contained in the coloring composition.

[0085] Polyhydric alcohols have two or more hydroxyl groups in the molecule and can be divided into, for example, alkanediols and polyols.

[0086] Examples of alkanediols include compounds in which an alkane is substituted with two hydroxyl groups. Examples of alkanediols include ethylene glycol (also known as ethane-1,2-diol), 1,2-butanediol, 1,2-pentanediol, 1,2-octanediol, 1,3-propanediol, 1,3-butylene glycol (also known as 1,3-butanediol), 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 2,4-pentanediol, and 2-methyl-1,3 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 3-methyl-1,3-butanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-pentanediol, 3-methyl-1,5-pentanediol, 2-methylpentane-2,4-diol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, and the like.

[0087] Examples of polyols include condensates in which two or more molecules of alkanediols are intermolecularly condensed via the hydroxyl groups, compounds having three or more hydroxyl groups, etc. Among polyols, those with two hydroxyl groups are called glycols.

[0088] Examples of condensates in which two or more molecules of alkanediols are intermolecularly condensed via the hydroxyl groups thereof include dialkylene glycols such as diethylene glycol and dipropylene glycol, and trialkylene glycols such as tripropylene glycol.

[0089] The compound having three or more hydroxyl groups is a compound having an alkane or polyether structure as a backbone and having three or more hydroxyl groups, such as glycerin, trimethylolethane, trimethylolpropane, 1,2,5-hexanetriol, 1,2,6-hexanetriol, pentaerythritol, and polyoxypropylenetriol.

[0090] The organic solvents may be used alone or in combination of two or more.

[0091] Among the above organic solvents, it is preferable to include one or more selected from alkylene glycol ethers and cyclic esters, and it is particularly preferable to include one or more selected from tetraethylene glycol monobutyl ether and γ-butyrolactone.

[0092] The total content of all organic solvents is preferably 1% by mass or more, more preferably 5% by mass or more, and particularly preferably 10% by mass or more, relative to the total mass of the coloring composition. It is even more preferably 20% by mass or more, and even more preferably 30% by mass or more. The upper limit of the organic solvent content is preferably 80% by mass or less, preferably 60% by mass or less, preferably 50% by mass or less, and more preferably 40% by mass or less. It is also preferable that the organic solvent content be within the above range relative to the total mass of the liquid medium components contained in the coloring composition.

[0093] Dispersants The coloring composition may contain a dispersant. Examples of the dispersant include a resin dispersant and a polyoxyalkyleneamine compound, and the dispersant is selected from those that can improve the dispersion stability of the metal pigment in the coloring composition.

[0094] Examples of the resin dispersant include (meth)acrylic resins and salts thereof such as poly(meth)acrylic acid, (meth)acrylic acid-acrylonitrile copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid ester copolymer, vinyl acetate-(meth)acrylic acid copolymer, and vinylnaphthalene-(meth)acrylic acid copolymer; styrene-(meth)acrylic acid copolymer, styrene-(meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-α-methylstyrene-(meth)acrylic acid copolymer, and styrene-α-methylstyrene-(meth)acrylic acid copolymer. Examples of suitable water-soluble resins include styrene-based resins such as acrylic acid-(meth)acrylic acid ester copolymer, styrene-maleic acid copolymer, and styrene-maleic anhydride copolymer, and salts thereof; urethane-based resins and salts thereof which are polymeric compounds (resins) containing urethane bonds formed by the reaction of an isocyanate group and a hydroxyl group and may be linear and / or branched, and may have a crosslinked structure; polyvinyl alcohols; vinyl naphthalene-maleic acid copolymers and salts thereof; vinyl acetate-maleic acid ester copolymers and salts thereof; and vinyl acetate-crotonic acid copolymers and salts thereof.

[0095] The polyoxyalkyleneamine compound may be an amine compound having a polyoxyalkylene structure in the molecule. Commercially available polyoxyalkyleneamine compounds include JEFFAMIN M2070 (manufactured by Huntsman) and GENAMIN (M41 / 2000) (manufactured by Clariant).

[0096] When the coloring composition contains a dispersant, the lower limit of the content of the dispersant is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.06% by mass or more, and even more preferably 0.10% by mass or more. The upper limit of the content of the dispersant is not particularly limited, but is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, even more preferably 0.5% by mass or less, and particularly preferably 0.3% by mass or less.

[0097] Resin The coloring composition according to this embodiment may contain a resin. The resin can function as a binder. Examples of resins include acrylic resins, rosin-modified resins, terpene resins, polyester resins, polyamide resins, epoxy resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymers, cellulose-based resins (e.g., cellulose acetate butyrate, hydroxypropyl cellulose), polyvinyl butyral, polyacrylic polyols, polyvinyl alcohols, and urethane resins. Among these, it is preferable to include one or more selected from acrylic resins, polyester resins, urethane resins, and cellulose-based resins, and it is more preferable to include an acrylic resin. The acrylic resin is a resin obtained by polymerizing at least an acrylic monomer, and may be a copolymer resin of an acrylic monomer and another monomer. Examples of other monomers include vinyl monomers.

[0098] The lower limit of the resin content is preferably 0.01% by mass or more, more preferably 0.06% by mass or more, even more preferably 0.10% by mass or more, and particularly preferably 0.15% by mass or more, relative to the total mass of the coloring composition. The upper limit of the resin content is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, even more preferably 0.5% by mass or less, and particularly preferably 0.3% by mass or less, relative to the total mass of the coloring composition.

[0099] 1.4.4. Other ingredients The coloring composition according to the present embodiment may further contain the following components: Examples of such components include a leveling agent, a polymerization accelerator, a polymerization inhibitor, a photopolymerization initiator, a dispersant, a surfactant, a penetration accelerator, a moisturizer, a colorant, a fixing agent, an antifungal agent, a preservative, an antioxidant, a chelating agent, a thickener, and a sensitizer.

[0100] Preferred examples of the surfactant include silicone surfactants and acetylene glycol surfactants.

[0101] 1.5. Effects, etc. In metallic pigments such as aluminum, whose surfaces are treated with a surface treatment agent to improve water resistance and leafing properties, the fluorine-based surface treatment agents that have been used to date have been insufficient in terms of dispersion stability, water resistance, and the metallic luster of printed materials, which is related to these factors. In particular, in water-based metallic compositions, metal pigments (especially aluminum pigments) can be oxidized by water, generating hydrogen. This can result in poor luster and in insufficient dispersion stability in aqueous media. Furthermore, when the particle size of the metallic pigment is large, if the particles settle during storage, the sediment may not disintegrate, resulting in poor dispersibility. Furthermore, there is a risk that the use of fluorine-based treatment agents may be restricted due to stricter regulations under treaties and other regulations.

[0102] In contrast, the coloring composition of the present embodiment uses a specific surface treatment agent, so that even if the particle size of the metallic pigment is somewhat large and sedimentation occurs, the sedimented components can be easily loosened by stirring, shaking the container, etc., and the coloring composition has excellent dispersibility and dispersion recovery. Furthermore, when the particle size is relatively large, the water resistance is excellent and the metallic luster of the coating film formed can be made better.

[0103] The coloring composition of the present embodiment contains the organic solvent (A) and the organic solvent (B), and thereby the affinity between the surface of the metal pigment, which is inclined to the hydrophobic side due to the improvement in water resistance, and water, which is the main medium, can be gradually improved, thereby improving the dispersion stability of the metal pigment and forming a colored product with good water resistance and metallic luster.

[0104] 2. Pigment dispersion The pigment dispersion is a pigment dispersion used in preparing the above-mentioned coloring composition, and is an aqueous pigment dispersion containing the above-mentioned metal pigment, water, an organic solvent (A), and an organic solvent (B). The pigment dispersion can be used to obtain a coloring composition by mixing other necessary components. Therefore, the content of the metal pigment in the pigment dispersion used in preparing the coloring composition is relatively higher than the content of the metal pigment in the coloring composition, and is also higher than the content of the metal pigment in a coloring composition prepared using the pigment dispersion.

[0105] This pigment dispersion can be used to prepare a coloring composition that can form a colored product with good water resistance and metallic luster and maintain good dispersibility. The desired coloring composition can be easily obtained by adding appropriate components to the pigment dispersion depending on the application, required viscosity, etc. of the coloring composition.

[0106] 3. Coloring method The coloring method includes a step of adhering the coloring composition to an object to be colored. The object to be colored may have any shape. The object to be colored may be made of any material. The method of adhering the composition to the object to be colored is not limited, and the composition may be applied by brush coating, roller coating, spray coating, bar coater coating, or inkjet coating. The viscosity and other properties of the coloring composition can be selected by changing the type and concentration of the components depending on the method of application.

[0107] The object to be colored may be anything that can be colored, and examples thereof include recording media, plates, and objects of any shape.

[0108] The coloring method may include a pretreatment step of the object to be colored, a drying step, etc. According to this coloring method, a coating film having good water resistance and gloss can be formed on the object to be colored.

[0109] 4. Examples and Comparative Examples The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" below is based on mass.

[0110] 4.1. Preparation of coloring composition (Production of metallic pigment dispersions) A release resin solubilized in acetone was coated onto a 20 μm PET substrate using a roll coater to form a release layer. The PET substrate with the release layer was transported to an aluminum vacuum deposition machine at a speed of 5 m / s, and an aluminum layer with a thickness of 15 nm was formed under reduced pressure. The aluminum / release resin / PET substrate was immersed in a tetrahydrofuran tank and irradiated with 40 kHz ultrasound to peel the aluminum pigment from the PET substrate, yielding an aluminum pigment peeling solution. The tetrahydrofuran was then removed using a centrifuge, and an appropriate amount of diethylene glycol diethyl ether was added to obtain an aluminum particle suspension with an aluminum concentration of 5% by mass.

[0111] The aluminum particle suspension was pulverized by stirring until the target average particle diameter was reached, thereby obtaining an inkjettable aluminum particle suspension with a volume average particle diameter D50 of 0.47 μm. In Examples 32 to 35, the pulverization was performed by adjusting the stirring time and intensity so as to achieve the average particle diameter of the metal pigment shown in the table.

[0112] In all examples, after the grinding step, Jeffamine M-2070 was added as a poly(oxyethylene / oxypropylene)amine dispersant to an aluminum concentration ratio of 5%, and the mixture was stirred and heat-treated at 55°C for 1 hour to break down the agglomerates and disperse the aluminum particles into primary particles, thereby producing an aluminum particle suspension. In Example 31, Jeffamine M-2070 was not added.

[0113] To the dispersed aluminum particle suspension, a surface treatment agent listed in Tables 1 to 8 was added. The surface treatment agent was added so that the mass ratio of the surface treatment agent to the aluminum particles was the mass ratio listed in the tables. The mixture was then stirred and heat-treated at 55°C for 3 hours, thereby surface-treating the aluminum particles with the surface treatment agent. In this way, a dispersion of surface-treated aluminum pigment was obtained.

[0114] The resulting aluminum pigment dispersion was centrifuged to remove the solvent and replace it with an aqueous solvent. At this time, water and organic solvent were added in amounts half that of the final composition, so that the solids concentration of the metal pigment was higher than in the final composition. At this point, the pigment dispersion was prepared. The remaining components listed in Tables 1 to 8 were then mixed to adjust the concentration, thereby preparing the coloring compositions of each Example and Comparative Example.

[0115] Except for Example 31, an amine dispersant (Jeffamine M-2070) was added as needed to achieve the amine dispersant content in the composition shown in the table.

[0116] Analysis of the solvent removed from the dispersion of the surface-treated aluminum pigment after the surface treatment revealed that no surface treatment agent was contained in any of the examples. From this, it is presumed that the surface treatment agent in each example in the table adheres to the metal particles contained in the composition.

[0117] [Table 1]

[0118] [Table 2]

[0119] [Table 3]

[0120] [Table 4]

[0121] [Table 5]

[0122] [Table 6]

[0123] [Table 7]

[0124] [Table 8]

[0125] The ingredients used in each table are as follows: Octadecylphosphonic acid (Tokyo Chemical Industry Co., Ltd.) Dodecylphosphonic acid (Tokyo Chemical Industry Co., Ltd.) Tridecylphosphonic acid (Tokyo Chemical Industry Co., Ltd.) Dodecylphosphonic acid (Tokyo Chemical Industry Co., Ltd.) Octylphosphonic acid (Tokyo Chemical Industry Co., Ltd.) Perfluorohexylphosphonic acid (Tokyo Chemical Industry Co., Ltd.) Silane coupling agent: Octadecyltrimethoxysilane (Tokyo Chemical Industry Co., Ltd.) Propylene glycol (water solubility 1000g / L or more) Hexylene glycol (water solubility 1000g / L or more) TEGMME: Triethylene glycol monomethyl ether (water solubility 1000g / L or more) PGMBE: Propylene glycol monobutyl ether (water solubility 1000g / L or more) PGMME: Propylene glycol monomethyl ether (water solubility 1000g / L or more) Ethyl lactate (water solubility 1000g / L or more) Triethylene glycol (water solubility 1000g / L or more) Ethanol (water solubility 1000g / L or more) 3-Methoxy-3-methylbutanol (water solubility 1000g / L or more) 2-phenoxyethanol (slightly water soluble, 100g / L or less) 1-butanol (slightly soluble in water, 100g / L or less) Butyl lactate (slightly water soluble, 100g / L or less) 2-Ethyl-hexanol (slightly soluble in water, 100g / L or less) 2-butanol (slightly soluble in water, 100g / L or less)

[0126] 4.2.Evaluation Method 4.2.1. Gloss evaluation Recorded materials of each example were created using a modified Seiko Epson SC-S80650. The nozzle density of the nozzle row of the inkjet head was 360 npi, 360 nozzles. The inkjet head was filled with the coloring composition of each example. The drive waveform of the inkjet head was optimized to ensure optimal ejection. A polyvinyl chloride film (Mactac5829R, manufactured by Mactac) was used as the recording medium. When recording, the amount of ink attached to the recording pattern was 5 mg / inch. 2 The recording resolution was 1440 x 1440 dpi. In Examples 32 to 35, the coating was applied using a bar coater so that the same amount of coating was obtained as above. These examples are particularly suitable as coating materials.

[0127] The gloss of the printed portion of each example was measured at a tilt angle of 60° using a gloss meter, MINOLTA MULTI GLOSS 268, and evaluated according to the following criteria: The higher this value, the better the gloss. A: Glossiness of 400 or more B: Glossiness is 350 or more and less than 400 C: Glossiness is 3000 or more and less than 350 D: Glossiness is 250 or more and less than 300 E: Glossiness less than 250

[0128] 4.2.2. Particle size (dispersibility) evaluation For each example and comparative example, a portion of a 5% by mass suspension of a metal pigment containing diethylene glycol diethyl ether obtained during the production process of the aqueous composition was taken, to which Esreem AD-374M (NOF Corporation), a dispersant that exhibits good dispersibility in non-aqueous media, was added to disperse the metal particles to form a dispersion. The volume average particle diameter D50 of the metal particles contained in this dispersion was measured using a Microtrac MT-3300 (Microtrac-Bell, laser diffraction / scattering particle size distribution analyzer). The volume average particle diameter D50 of the metal particles contained in this dispersion was used as the reference value.

[0129] 100 ml of the aqueous composition finally obtained in each Example and Comparative Example was placed in a glass container, sealed, and left at room temperature for one month. After leaving the container, the container was shaken 10 times, and the volume average particle diameter D50 of the metal particles contained in the composition was measured and compared with a reference value to evaluate the dispersibility of the metal particles according to the following criteria. The smaller the ratio of the volume average particle diameter D50 of the metal particles contained in the aqueous composition to the reference value, the better the dispersibility of the metal particles. The reference value is taken as 100%. In examples where the average particle diameter of the metal particles was 3 μm or more, sedimentation of the metal particles was observed after leaving the composition for one month. A: The ratio of D50 of metal particles contained in the aqueous composition to the standard value is less than 110%. B: The ratio of D50 of metal particles contained in the aqueous composition to the standard value is 110% or more and less than 150%. C: The ratio of D50 of metal particles contained in the aqueous composition to the standard value is 150% or more and less than 200%. D: The ratio of D50 of metal particles contained in the aqueous composition to the standard value is 200% or more and less than 500%. E: The ratio of D50 of metal particles contained in the aqueous composition to the standard value is 500% or more

[0130] 4.2.3.Water resistance evaluation The colored composition of each example was sealed in a pack and left in a thermostatic chamber at 70°C for 6 days, and the amount of gas generated per unit mass of the composition was determined and the water resistance was evaluated according to the following criteria. The smaller the amount of gas generated, the better the water resistance. (Evaluation criteria) A: The amount of gas generated is less than 0.2 ml / g B: The amount of gas generated is 0.2 ml / g or more and less than 0.4 ml / g C: The amount of gas generated is 0.4 ml / g or more but less than 1.0 ml / g D: The amount of gas generated is 1.0 ml / g or more and less than 5.0 ml / g E: The amount of gas generated is 5.0 ml / g or more.

[0131] 4.3.Evaluation Results In Table 1, the difference was confirmed by changing the organic solvent (B) with a water solubility of 100 g / L or less. In Table 2, the difference was confirmed by changing the organic solvent (A) with a water solubility of 1000 g / L or more. In Table 3, a comparative example was confirmed in which an organic solvent (B) with a water solubility of 100 g / L or less was not used. In Table 4, a comparative example was confirmed in which an organic solvent (A) with a water solubility of 1000 g / L or more was not used. In Table 5, the difference was confirmed by changing the content of organic solvent (A) and organic solvent (B). In Table 6, the difference was confirmed by changing the content of organic solvent (A) and organic solvent (B) and the content ratio "organic solvent (B) / organic solvent (A)". In Table 7, the difference was confirmed by changing the type of surface treatment agent. In Table 8, the difference was confirmed by changing the particle size of the metal pigment.

[0132] It was found that the aqueous coloring compositions of each example, which contain a metal pigment, which is metal particles whose surfaces have been treated with a specific surface treatment agent, water, and an organic solvent, and the organic solvent includes an organic solvent (A) having a water solubility of 1000 g / L or more at 20°C and an organic solvent (B) having a water solubility of 100 g / L or less at 20°C, all have good water resistance and dispersibility, and can produce colored products with excellent gloss.

[0133] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be combined as appropriate.

[0134] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations that replace non-essential parts of the configurations described in the embodiments. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations that add publicly known technology to the configurations described in the embodiments.

[0135] The following can be derived from the above-described embodiment and modifications.

[0136] The coloring composition is a water-based coloring composition, Contains a metal pigment, water, and an organic solvent, The metal pigment is a metal particle whose surface has been treated with a compound represented by formula (1) or formula (2), The organic solvents include an organic solvent (A) having a water solubility of 1000 g / L or more at 20°C and an organic solvent (B) having a water solubility of 100 g / L or less at 20°C. (R 1 -)P(O)(OH)2···(1) (R 2 -O-) a P(O)(OH) 3-a ···(2) (In the formula, R 1 , R 2 each independently represents a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents, and a represents 1 or 2.

[0137] This coloring composition provides good water resistance and excellent dispersibility of the metallic pigment, and can provide a colored product with good gloss.

[0138] In the coloring composition, The organic solvent (A) and the organic solvent (B) may be selected from alkanediols, glycols, glycol ethers, monohydric alcohols, and esters.

[0139] In the coloring composition, The content ratio (B / A) of the organic solvent (A) to the organic solvent (B) may be 0.1 or more and 1.5 or less.

[0140] This coloring composition also provides good dispersibility of the metal pigment.

[0141] In the coloring composition, The total content of the organic solvent (A) and the organic solvent (B) may be 8% by mass or more and 45% by mass or less.

[0142] This coloring composition also provides good dispersibility of the metal pigment.

[0143] In the coloring composition, The organic solvent (B) may be selected from aromatic monohydric alcohols and aliphatic monohydric alcohols having 4 or more carbon atoms.

[0144] This coloring composition also provides good dispersibility of the metal pigment.

[0145] In the coloring composition, The content of the organic solvent (A) may be 5% by mass or more and 50% by mass or less, based on the total amount of the composition, and the content of the organic solvent (B) may be 1% by mass or more and 10% by mass or less, based on the total amount of the composition.

[0146] This coloring composition also provides good dispersibility of the metal pigment.

[0147] In the coloring composition, The metal pigment may have a volume average particle diameter D50 of 3 μm or more and 15 μm or less.

[0148] This coloring composition makes it possible to obtain a coating film with even better metallic luster.

[0149] In the coloring composition, The metal pigment may have a volume average particle diameter D50 of 1 μm or less.

[0150] This coloring composition makes it possible to obtain images with even better metallic luster.

[0151] In the coloring composition, In the formula (1) and formula (2), R 1 and R 2 may independently represent a hydrocarbon group having 12 to 30 carbon atoms which may be substituted with one or more substituents.

[0152] This coloring composition provides the metal pigment with even better water resistance.

[0153] In the coloring composition, It may also be used as a coating composition.

[0154] In the coloring composition, The metal particles may be made of aluminum or an aluminum alloy.

[0155] This coloring composition makes it possible to obtain colored products with even better metallic luster.

[0156] In the coloring composition, The surface treatment agent may be used in an amount of 1% by mass or more and 50% by mass or less relative to 100% by mass of the total mass of the metal particles.

[0157] This coloring composition makes it possible to obtain colored products with even better metallic luster.

[0158] In the coloring composition, The metal particles may be in the form of scales.

[0159] This coloring composition makes it possible to obtain colored products with even better metallic luster.

[0160] The coloring method is The method includes a step of applying any one of the above coloring compositions to an object to be colored.

[0161] This coloring method makes it possible to form a coating film with good water resistance and gloss.

[0162] The pigment dispersion is The pigment dispersion used in the preparation of any of the above coloring compositions contains the metal pigment, water, the organic solvent (A), and the organic solvent (B).

[0163] This pigment dispersion allows the preparation of a coloring composition that provides good water resistance and dispersibility of the metal pigment and is capable of forming an image with excellent gloss.

Claims

1. Contains a metal pigment, water, and an organic solvent, The metal pigment is a metal particle whose surface has been treated with a compound represented by formula (1) or formula (2), The organic solvent includes an organic solvent (A) having a water solubility of 1000 g / L or more at 20°C and an organic solvent (B) having a water solubility of 100 g / L or less at 20°C, the organic solvent (A) and the organic solvent (B) are selected from alkanediols, glycols, glycol ethers, monohydric alcohols, and esters; The aqueous coloring composition, wherein the content ratio (B / A) of the organic solvent (A) to the organic solvent (B) is 0.1 or more and 1.5 or less. (R 1 -)P(O)(OH) 2 ・・・(1) (R 2 -O-) a P(O)(OH) 3-a ・・・(2) (In the formula, R 1 , R 2 each independently represents a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents, and a represents 1 or 2.

2. A coating composition comprising a metal pigment, water, and an organic solvent, The metal pigment is a metal particle whose surface has been treated with a compound represented by formula (1) or formula (2), The organic solvent includes an organic solvent (A) having a water solubility of 1000 g / L or more at 20°C and an organic solvent (B) having a water solubility of 100 g / L or less at 20°C, the organic solvent (A) and the organic solvent (B) are selected from alkanediols, glycols, glycol ethers, monohydric alcohols, and esters; the content of the organic solvent (A) is 5% by mass or more and 50% by mass or less, based on the total amount of the composition, and the content of the organic solvent (B) is 1% by mass or more and 10% by mass or less, based on the total amount of the composition. (R 1 -)P(O)(OH) 2 ... (1) (R 2 -O-) a P(O)(OH) 3-a...(2) (In the formula, R 1 and R 2 independently represent a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents, and a represents 1 or 2.)

3. A coating composition comprising a metal pigment, water, and an organic solvent, The metal pigment is a metal particle whose surface has been treated with a compound represented by formula (1) or formula (2), The organic solvent includes an organic solvent (A) having a water solubility of 1000 g / L or more at 20°C and an organic solvent (B) having a water solubility of 100 g / L or less at 20°C, the organic solvent (B) is selected from aromatic monohydric alcohols and aliphatic monohydric alcohols having 4 or more carbon atoms, The aqueous coloring composition, wherein the content ratio (B / A) of the organic solvent (A) to the organic solvent (B) is 0.1 or more and 1.5 or less. (R 1 -)P(O)(OH) 2 ... (1) (R 2 -O-) a P(O)(OH) 3-a...(2) (In the formula, R 1 and R 2 independently represent a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents, and a represents 1 or 2.)

4. A coating composition comprising a metal pigment, water, and an organic solvent, The metal pigment is a metal particle whose surface has been treated with a compound represented by formula (1) or formula (2), The organic solvent includes an organic solvent (A) having a water solubility of 1000 g / L or more at 20°C and an organic solvent (B) having a water solubility of 100 g / L or less at 20°C, the organic solvent (B) is selected from aromatic monohydric alcohols and aliphatic monohydric alcohols having 4 or more carbon atoms, the content of the organic solvent (A) is 5% by mass or more and 50% by mass or less, based on the total amount of the composition, and the content of the organic solvent (B) is 1% by mass or more and 10% by mass or less, based on the total amount of the composition. (R 1 -)P(O)(OH) 2 ... (1) (R 2 -O-) a P(O)(OH) 3-a...(2) (In the formula, R 1 and R 2 independently represent a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents, and a represents 1 or 2.)

5. In any one of claims 1 to 4, The aqueous coloring composition has a total content of the organic solvent (A) and the organic solvent (B) of 8% by mass or more and 45% by mass or less.

6. In any one of claims 1 and 2, The aqueous coloring composition, wherein the organic solvent (B) is selected from aromatic monohydric alcohols and aliphatic monohydric alcohols having 4 or more carbon atoms.

7. In any one of claims 1 to 6, The aqueous coloring composition, wherein the metal pigment has a volume average particle diameter D50 of 3 μm or more and 15 μm or less.

8. In any one of claims 1 to 7, The aqueous coloring composition, wherein the metal pigment has a volume average particle diameter D50 of 1 μm or less.

9. In any one of claims 1 to 8, In the formulas (1) and (2), R 1 and R 2 each independently represents a hydrocarbon group having 12 to 30 carbon atoms which may be substituted with one or more substituents.

10. In any one of claims 1 to 9, A water-based coloring composition for use as a coating composition.

11. In any one of claims 1 to 10, The aqueous coloring composition, wherein the metal particles are made of aluminum or an aluminum alloy.

12. In any one of claims 1 to 11, The surface treatment agent is used in an amount of 1% by mass or more and 50% by mass or less relative to 100% by mass of the total mass of the metal particles.

13. In any one of claims 1 to 12, The water-based coloring composition, wherein the metal particles are scaly.

14. A coloring method comprising a step of applying the coloring composition according to claim 1 to an object to be colored.

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