Pigment composition and coloring method

Abstract

To provide a pigment composition having excellent dispersibility of a base metal pigment in an aqueous composition and excellent gloss of a body to be colored using the composition.SOLUTION: There is provided a pigment composition which comprises a base metal pigment, a dispersant and water, wherein the base metal pigment is metal particles, the surface of which is treated with a compound represented by formula (1) or formula (2) and the dispersant contains an amine compound having a polyester structure and is aqueous. (R1-)P(O)(OH)2 (1), (R2-O-)aP(O)(OH)3-a (2). (In the formulae, R1 and R2 each independently represents a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents, and a is 1 or 2.)SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a pigment composition and a coloring method.

Background Art

[0002] Conventionally, pigment compositions containing base metal pigments such as aluminum, which are used to produce colored bodies having a metallic luster, have been developed. In recent years, from the viewpoints of environmental aspects and ease of handling, aqueous compositions having water as the main solvent have been preferred over non-aqueous compositions having an organic solvent as the main solvent in the development of compositions. For example, Patent Document 1 discloses an aqueous composition containing a base metal pigment surface-treated with a fluorine-based compound.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in terms of the dispersibility of the base metal pigment in the aqueous composition and the luster of the colored body using the composition, it was still insufficient.

Means for Solving the Problems

[0005] One aspect of the pigment composition according to the present invention contains a base metal pigment, a dispersant, and water, the base metal pigment is metal particles whose surface is treated with a compound represented by formula (1) or formula (2), the dispersant contains an amine compound having a polyester structure, and is aqueous. (R 1 -)P(O)(OH)2···(1) (R 2 -O-)a P(O)(OH) 3-a ···(2) (In the formula, R 1 , R 2 are each independently a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents. a is 1 or 2.)

[0006] One aspect of the coloring method according to the present invention is where the pigment composition of the above aspect is a coloring composition, and includes a step of attaching the coloring composition to a coloring object.

Mode for Carrying Out the Invention

[0007] Embodiments of the present invention will be described below. The embodiments described below illustrate examples of the present invention. The present invention is not limited to the following embodiments, and also includes various modified forms implemented within the scope not changing the gist of the present invention. Note that not all of the configurations described below are essential configurations of the present invention.

[0008] 1. Pigment Composition The pigment composition according to an embodiment of the present invention contains a base metal pigment, a dispersant, and water. The base metal pigment is metal particles whose surface is treated with a compound represented by formula (1) or formula (2). The dispersant includes an amine compound having a polyester structure and is aqueous. (R 1 -)P(O)(OH)2···(1) (R 2 -O-) a P(O)(OH) 3-a ···(2) (In the formula, R 1 , R 2 are each independently a hydrocarbon group having 12 or more carbon atoms which may be substituted with one or more substituents. a is 1 or 2.)

[0009] In the case of base metal pigments such as aluminum contained in aqueous compositions, surface treatment is performed using surface treatment agents to obtain properties such as water resistance and leafing (the effect of adhering base metal pigments to the surface of the object to be coated in parallel or nearly parallel manner, mainly due to the action of surface tension). Furthermore, surface treatment using specific long-chain alkyl phosphate-based treatment agents (hereinafter also referred to as "specific surface treatment agents") has been investigated, as they are superior to conventional fluorine-based surface treatment agents in terms of water resistance and dispersion stability, and are also advantageous from an environmental standpoint. However, even when using such specific surface treatment agents, the dispersibility of base metal pigments in aqueous compositions and the gloss of the object to be colored using the composition were still insufficient.

[0010] We have recently discovered that using an amine compound having a polyester structure as a dispersant results in superior dispersibility, gloss, and water resistance with the above-mentioned specific surface treatment agent. This is presumed to be because the phosphorus-containing acid group of the above-mentioned specific surface treatment agent tends to result in a relatively low pH (for example, acidic around pH 5), and the above-mentioned amine compound, which is activated and positively charged at around this pH, dissolves easily in the aqueous composition. In other words, this is thought to improve compatibility and dispersibility. In addition, when the above-mentioned amine compound is included, it is easier to maintain the pH of the aqueous composition on the original acidic side, reducing the likelihood of the surface treatment agent detaching or being replaced on the base metal pigment surface, and thus improving water resistance.

[0011] In the present invention, "pigment composition" refers to a composition containing a pigment. Examples of pigment compositions, though not limited to these, include coloring compositions and pigment dispersions.

[0012] A "coloring composition" is a composition used to color an object to be colored. Examples of coloring compositions, though not limited to them, include inks and paints.

[0013] A "pigment dispersion" is a composition used in the preparation of a coloring composition. The pigment concentration in the pigment dispersion is relatively higher than the pigment concentration in the coloring composition, and is higher than the pigment concentration in the coloring composition prepared using the pigment dispersion.

[0014] The following describes each component included in the pigment composition according to this embodiment.

[0015] 1.1 Base metal pigments The pigment composition according to this embodiment contains a base metal pigment. The base metal pigment is a metal particle whose surface has been treated with a specific surface treatment agent, which will be described later. More specifically, it is presumed that the phosphorus-containing acid group portion of the specific surface treatment agent is chemically bonded to the surface of the metal particle. In this case, the specific surface treatment agent itself is not necessarily bonded to the surface of the metal particle by hydrogen bonds or intermolecular forces, etc., and may be a metal particle having residues of the specific surface treatment agent. That is, in the case of the base metal pigment, it is thought that the OH groups that may be present on the surface of the metal particle react with the phosphorus-containing acid group portion of the specific surface treatment agent, thereby bonding the metal particle and the specific surface treatment agent by covalent bonds. Alternatively, the specific surface treatment agent may adhere to the surface of the metal particle by physical adsorption, etc. In this way, it is thought that the specific surface treatment agent adheres to the metal particle by bonding, physical adsorption, etc.

[0016] The content of base metal pigments is not particularly limited, but is preferably 0.1 to 30% by mass, more preferably 0.1 to 15% by mass, even more preferably 0.1 to 5.0% by mass, and more preferably 0.3 to 3.0% by mass, relative to the total mass of the pigment composition. More preferably, the amount is 0.5 to 2.0% by mass, and more preferably 0.7 to 1.5% by mass. On the other hand, 10 to 30% by mass is preferred, and 20 to 30% by mass is more preferred. When the base metal pigment content is within the above range, the dispersion stability of the pigment composition tends to improve, and the gloss also tends to be better.

[0017] 1.1.1 Metal particles The metal particles are composed of a metallic material in at least a portion of their visible surface, for example, the entire particle or the area near the outer surface is composed of a metallic material. The metal particles have the function of imparting metallic luster to colored products manufactured using a pigment composition.

[0018] [Materials] The metal particles only need to be composed of a metallic material in at least the region including the vicinity of the surface. For example, the entire metal particle may be composed of a metallic material, or it may have a base made of a non-metallic material and a coating made of a metallic material covering the base. Furthermore, the metal particles may have an oxide film or the like, such as a passivation film, formed on their surface.

[0019] The metallic material constituting the metal particles must contain a base metal, and it is more preferable that it consists of a base metal. Here, "base metal" in this invention refers to any metal whose ionization tendency is greater than that of hydrogen, and includes elements of metals such as alkali metals, alkaline earth metals, aluminum, iron, zinc, lead, copper, nickel, cobalt, and chromium, as well as alloys thereof.

[0020] Among the above-mentioned metal materials, it is preferable that the metal particles consist of aluminum or an aluminum alloy. Because such base metals have a relatively low specific gravity, they tend to have better dispersion stability in the pigment composition. Furthermore, while such base metals are preferable from the viewpoint of ensuring gloss and cost, they can be oxidized in the presence of moisture, which can reduce gloss and cause the metal particles to aggregate. In contrast, if the metal particles are surface-treated with a specific surface treatment agent described later, they will have good gloss and dispersibility, and the desirable properties of such base metals can be enjoyed.

[0021] 〔shape〕 The shape of the metal particles is not particularly limited, but examples include flake-shaped, spherical, spindle-shaped, and needle-shaped particles. Among these, the flake shape is preferred. Because the metal particles are flake-shaped, the base metal pigment can be arranged on the substrate to which the pigment composition is attached so that the main surface conforms to the surface shape of the substrate, and the gloss and other properties inherent to the base metal pigment tend to be expressed more effectively.

[0022] In the present invention, "scale-like" means plate-like, and for example, when observed from a predetermined angle, the area when viewed from a planar perspective is larger than the area when observed from an angle perpendicular to the direction of observation. In particular, the area S1 [μm²] when observed from the direction that maximizes the projected area, i.e., when viewed from a planar perspective. 2 ] and the area S0 [μm²] observed from the direction perpendicular to the observation direction that yields the largest observed area. 2 The ratio S1 / S0 to ] is preferably 2 or more, more preferably 5 or more, even more preferably 8 or more, even more preferably 10 or more, particularly preferably 20 or more, and most particularly preferably 30 or more. The upper limit of S1 / S0 is not particularly limited, but is preferably 1000 or less, more preferably 500 or less, even more preferably 100 or less, and particularly preferably 80 or less. On the other hand, 300 to 700 is preferred, and 400 to 600 is more preferred. Note that the term "scale-like" also includes shapes such as flat plates and curved plates.

[0023] The value of the above ratio S1 / S0 can be determined, for example, by observing any 50 particles and adopting the average value calculated for these particles. Observations can be performed using, for example, an electron microscope or an atomic force microscope. Alternatively, the volume-average particle diameter D50 and the average thickness of the base metal pigment, as described later, can be used, and after matching the units, the value can be expressed as volume-average particle diameter D50 / average thickness, and this can be used as the above range.

[0024] The preferred volume-average particle diameter D50 and average thickness for metal particles can be the same as those for base metal pigments, as described later. The preferred measurement method can also be the same.

[0025] [Manufacturing method] The metal particles may be manufactured by any method, but it is preferable that they be obtained by forming a film made of a base metal using a vapor deposition method, and then crushing the film. By using this method, even relatively thin metal particles can be suitably manufactured, and variations in properties between individual metal particles can be suppressed.

[0026] When producing metal particles using such a method, it is preferable to form a film made of a base metal on a substrate, for example. As the substrate, a plastic film such as polyethylene terephthalate can be used. Furthermore, the substrate may have a release agent layer on the film-forming surface.

[0027] Furthermore, grinding is preferably carried out by applying ultrasonic vibrations to the film in a liquid. This makes it easy to obtain metal particles with the desired particle size and tends to reduce variations in size, shape, and properties between individual metal particles.

[0028] Furthermore, when grinding using the method described above, suitable liquids include alcohols, hydrocarbon compounds, ether compounds, and polar compounds such as propylene carbonate, γ-butyrolactone, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, cyclohexanone, and acetonitrile. By using such liquids, oxidation of metal particles can be reduced while achieving particularly excellent metal particle productivity. In addition, variations in size, shape, and properties between individual metal particles tend to be reduced.

[0029] 1.1.2 Surface treatment agents Base metal pigments are metal particles whose surfaces have been treated with a compound represented by formula (1) or formula (2) (specific surface treatment agent). (R 1 -)P(O)(OH)2···(1) (R 2 -O-) a P(O)(OH) 3-a ...(2) (In the formula, R 1 , R 2 (a is 1 or 2.)

[0030] The compound represented by formula (1) above is one in which the hydrogen atoms of the phosphonic acid are R 1 These are compounds substituted with a group. Such compounds are R 1 Because the steric hindrance caused by the base portion is relatively small, the metal particles tend to be uniformly arranged on the surface, resulting in a better gloss for base metal pigments.

[0031] The compound represented by formula (2) above has one or two of the three hydroxyl groups of phosphoric acid as R 2 It is a compound esterified with a group. When a in formula (2) above is 1, that is, one of the three hydroxyl groups of phosphoric acid is R 2 When esterified with the group, R 2 by base site The steric hindrance is reduced, making it easier to uniformly arrange the metal particles on the surface, and tending to improve the dispersion stability and gloss of the base metal pigment. When a in formula (2) above is 2, that is, 2 of the 3 hydroxyl groups of phosphoric acid are R 2 When esterified with the group, R 2 The steric hindrance caused by the base portion becomes greater, increasing the effect of making it more difficult for water to approach the metal particle surface, and there is a tendency for base metal pigments to have better dispersibility and water resistance. When surface treatment is performed with the compound represented by formula (2) above, it is preferable that the compound represented by formula (2) above contains a compound in which a is represented by 2.

[0032] In the above formula, R 1and R 2 R is a hydrocarbon group having a carbon skeleton with 12 or more carbon atoms, which is a hydrocarbon group having a skeleton in which 12 or more carbon atoms are bonded in succession. In formula (1) above, R 1 In the above formula (2), R 2 One of the carbon atoms in the carbon skeleton with 12 or more carbon atoms is directly bonded to the oxygen atom of (RO-) O, and that oxygen atom is directly bonded to the phosphorus atom of P. That is, R bonded to P 1 The position of R connected to O. 2 Its location is not particularly limited.

[0033] Examples of hydrocarbon groups having a carbon skeleton with 12 or more carbon atoms include saturated hydrocarbon groups that do not have double or tripolymer bonds between carbon atoms, and unsaturated hydrocarbon groups that have double or tripolymer bonds between carbon atoms. 1 and R 2 The hydrocarbon group may be an aromatic hydrocarbon group having an aromatic ring structure in its carbon skeleton, or a linear or cyclic aliphatic hydrocarbon group. A linear aliphatic hydrocarbon group is particularly preferred because it offers superior dispersion stability and other advantages. The linear aliphatic hydrocarbon group may be branched or linear, but the linear type is preferred because it offers superior dispersion stability, discharge stability, and gloss.

[0034] The compound represented by formula (1) or formula (2) above is R in formula (1). 1 Or R in formula (2) above 2 However, independently, it is preferably a hydrocarbon group having 14 to 34 carbon atoms, more preferably a hydrocarbon group having 15 to 30 carbon atoms, even more preferably a hydrocarbon group having 15 to 26 carbon atoms, particularly preferably a hydrocarbon group having 15 to 22 carbon atoms, and most particularly preferably a hydrocarbon group having 16 to 20 carbon atoms. 1 , R 2 When the number of carbon atoms is within the above range, the material tends to exhibit superior dispersibility, gloss, and water resistance.

[0035] In the above formula, R 1and R 2 R is a hydrocarbon group which may be substituted with one or more substituents. That is, R 1 and R 2 It is sufficient if it contains carbon atoms and hydrogen atoms, has at least one bond between carbon atoms and hydrogen atoms, and has one or more unsubstituted hydrogen atoms.

[0036] R 1 and R 2 If R has no substituents, 1 and R 2 R is a hydrocarbon group consisting of carbon atoms and hydrogen atoms. For example, R 1 and R 2 Examples of groups that are chain-like aliphatic hydrocarbon groups include alkyl groups, alkenyl groups, and alkynyl groups.

[0037] R 1 and R 2 If some of the hydrogen atoms in the hydrocarbon group are substituted with substituents, the number of substituents is R 1 and R 2 The number of hydrogen atoms in the hydrocarbon group is preferably 50% or less, and more preferably 10% or less, when the molecule has no substituents. The number of substituents is preferably 5 or less, more preferably 3 or less, even more preferably 2 or less, and particularly preferably 1 or less. The number of substituents is 0 or more, and the lower limit of the number of substituents when substituted is 1 or more. It is preferable that the substituent is located on the carbon atom furthest from the phosphorus atom in the formula, as this tends to result in better dispersion stability.

[0038] Examples of substituents include carboxyl groups, hydroxyl groups, amino groups, and oxyalkylene-containing groups. Of these, oxyalkylene-containing groups are groups having an oxyalkylene structure, which is also called an alkylene oxide structure. The alkylene-containing group has one or more alkylene oxide units, and may have two or more. In particular, it may have a structure in which multiple 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, and more preferably 3 or more. The number of alkylene carbon atoms in the alkylene oxide unit is preferably 1 or more and 4 or less. Note R 1 and R 2 It is preferable that this is an unsubstituted hydrocarbon group that is not substituted with substituents.

[0039] Examples of compounds represented by formula (1) above include dodecylphosphonic acid (laurylphosphonic acid), tetradecylphosphonic acid (myristylphosphonic acid), hexadecylphosphonic acid (cetylphosphonic acid), octadecylphosphonic acid (stearylphosphonic acid), and it is preferable that one or more are selected from these. More preferably, one or more are selected from hexadecylphosphonic acid and octadecylphosphonic acid, and it is even more preferable that it is octadecylphosphonic acid.

[0040] Examples of compounds represented by formula (2) above, where a is 1, include monooctyl phosphate, monolauryl phosphate, monoisotridecyl phosphate, and monostearyl phosphate, and it is preferable that one or more are selected from these. More preferably, it is one or more selected from monoisotridecyl phosphate and monostearyl phosphate, and even more preferably monostearyl phosphate. Examples of compounds represented by formula (2) above, where a is 2, include dioctyl phosphate, dilauryl phosphate, diisotridecyl phosphate, and distearyl phosphate, and it is preferable that one or more are selected from these. More preferably, it is one or more selected from diisotridecyl phosphate and distearyl phosphate, and even more preferably distearyl phosphate.

[0041] The compound represented by formula (1) or formula (2) is preferably present in an amount of 0.5 to 60% by mass, more preferably 1 to 50% by mass, more preferably 5 to 45% by mass, even more preferably 10 to 40% by mass, particularly preferably 15 to 37% by mass, even more preferably 20 to 35% by mass, and especially preferably 25 to 35% by mass, based on 100% by mass of metal particles. Furthermore, the compound represented by formula (1) or formula (2) is also preferably present in an amount of 20% by mass or more, more preferably 24% by mass or more, even more preferably 27% by mass or more, and particularly preferably 30% by mass or more, based on 100% by mass of metal particles. When such mass is within the above range, the water resistance tends to be superior. This mass can also be said to be the amount of compound represented by formula (1) or formula (2) attached to the surface of the metal particles.

[0042] From a similar viewpoint, the compound represented by formula (1) or formula (2) is preferably present in an amount of 0.01 to 0.72% by mass, more preferably 0.10 to 0.60% by mass, even more preferably 0.20 to 0.50% by mass, particularly preferably 0.25 to 0.45% by mass, and most particularly preferably 0.30 to 0.40% by mass, based on 100% by mass of the pigment composition. This mass can also be said to be the amount of compound represented by formula (1) or formula (2) attached to the surface of the metal particles.

[0043] The pigment composition according to this embodiment may contain surface treatment agents other than the specified surface treatment agent described above, as long as the effects of the present invention are not impaired. Examples of such surface treatment agents include: Examples include fluorinated compounds. Preferably, fluorinated compounds include compounds containing fluorine and one or more elements selected from phosphorus, sulfur, and nitrogen as constituent elements. Specifically, examples include fluorinated phosphonic acids, fluorinated carboxylic acids, fluorinated sulfonic acids, and salts thereof.

[0044] Surface treatment of metal particles with a surface treatment agent may be carried out, for example, by including the surface treatment agent in the liquid when forming metal particles by crushing a metal film formed by a vapor phase deposition method in a liquid.

[0045] 1.1.3 Particle size and thickness The volume average particle size D50 of the base metal pigment is preferably 3 to 15 μm. In this case, the lower limit is more preferably 4 μm or more, even more preferably 5 μm or more, and particularly preferably 6 μm or more. In this case, the upper limit is more preferably 13 μm or less, even more preferably 11 μm or less, even more preferably 9 μm or less, particularly preferably 8.5 μm or less, even more preferably 8 μm or less, and especially preferably 7.5 μm or less. When the volume average particle size D50 of the base metal pigment is within the above range, when the pigment composition is used as a paint, it tends to have good water resistance, and a colored product with even better metallic luster due to the larger particle size is obtained. In addition, even if sedimentation of the components occurs, it tends to be possible to make a paint in which the components can be easily redispersed.

[0046] On the other hand, the volume average particle size D50 of the base metal pigment is preferably 1 μm or less. In this case, the upper limit is more preferably 0.80 μm or less, even more preferably 0.70 μm or less, particularly preferably 0.60 μm or less, and most particularly preferably 0.50 μm or less. In this case, the lower limit is not particularly limited, but is preferably 0.10 μm or more, more preferably 0.20 μm or more, and even more preferably 0.30 μm or more. When the volume average particle size D50 of the base metal pigment is within the above range, when the pigment composition is used as an inkjet ink composition, it tends to reduce nozzle clogging during inkjet ejection. In addition, when the particle size of the base metal pigment is within the above range, even if the specific surface area of ​​the base metal pigment is large, it tends to have good water resistance, and even if sedimentation of the components occurs, it tends to result in an ink that can be easily redispersed.

[0047] The volume-average particle size D50 refers to the median diameter of the volume distribution measured using a laser diffraction / scattering particle size distribution analyzer for a pigment composition. When multiple measurement results are expressed as the cumulative abundance ratio for each size, D50 represents the particle size that corresponds to exactly 50% of the median value in the cumulative distribution. In the case of flaky metal particles, the volume-average particle size D50 shall be determined based on the shape and size of the metal particles when converted to a spherical form.

[0048] The average thickness of the base metal pigment is preferably 30 nm or less. The lower limit of the average thickness of the base metal pigment is not particularly limited, but is preferably 3 nm or more, more preferably 5 nm or more, even more preferably 7 nm or more, and particularly preferably 9 nm or more. The upper limit of the average thickness of the base metal pigment is preferably 25 nm or less, more preferably 23 nm or less, even more preferably 21 nm or less, particularly preferably 19 nm or less, even more preferably 17 nm or less, and especially preferably 15 nm or less. When the average thickness of the base metal pigment is within the above range, the leafing properties tend to be improved and the gloss tends to be superior.

[0049] The average thickness of base metal pigments can be measured using an atomic force microscope (AFM). While not limited to this, for example, NanoNaviE-Sweep (SII Nanotechnologies) can be used. The measurement can be performed using atomic force microscopy with a device manufactured by Nology. For example, measurements are taken with any 50 base metal pigments and the average value is used. In other words, the average thickness is preferably the arithmetic mean thickness.

[0050] 1.2 Dispersant The pigment composition according to this embodiment contains a dispersant.

[0051] 1.2.1 Amine compounds having a polyester structure The dispersant contained in the pigment composition according to this embodiment includes an amine compound having a polyester structure.

[0052] The term "amine compound" is not particularly limited as long as it has one or more amine moieties in its molecular structure. The amine may be a primary amine, secondary amine, tertiary amine, or a salt thereof, and may also be a quaternary ammonium salt. It is preferable to have a large number of amine moieties. It is preferable to have a polyamine structure consisting of a large number of amine moieties.

[0053] The "polyester structure" is not particularly limited as long as it is a polymer structure having ester bonds. For example, it may be a polymer structure obtained by polycondensation from a diol such as terephthalic acid and a dicarboxylic acid such as 1,4-butanediol, or from a hydroxycarboxylic acid such as p-hydroxybenzoic acid, or it may be a polymer structure obtained by ring-opening polymerization of cyclic esters such as lactones.

[0054] In this specification, the polymer structure obtained by ring-opening polymerization of lactones in a "polyester structure" is referred to as a "polylactone structure."

[0055] The amine compound having a polyester structure is preferably an amine compound having a polylactone structure, and more preferably an amine compound having a polymer structure (polycaprolactone structure) obtained by ring-opening polymerization of ε-caprolactone. Such a compound can be made particularly excellent in terms of dispersibility, gloss, and water resistance with specific surface treatment agents.

[0056] Amine compounds having a polycaprolactone structure can also be commercially available, such as Lubrizol SOLPLUS® D510, Lubrizol SOLSPERSE® 39000, Lubrizol SOLSPERSE® 38500, Lubrizol SOLSPERSE® 32000, and Lubrizol SOLSPERSE® 24000.

[0057] Amine compounds having a polyester structure may further have substituents. Examples of such substituents include hydroxyl groups, alkoxy groups, carboxyl groups, carbonyl groups, amino groups, imino groups, pyrrolidone groups, cyano groups, azo groups, thiol groups, sulfo groups, nitro groups, halogens, and the like. Among these, it is preferable that the substituents include acidic groups such as hydroxyl groups, carboxyl groups, and sulfo groups, and basic groups such as amino groups, imino groups, and pyrrolidone groups.

[0058] The weight-average molecular weight (Mw) of the amine compound having a polyester structure is preferably 3,000 to 100,000, more preferably 10,000 to 80,000. The lower limit is more preferably 4,000 or more, even more preferably 5,000 or more, even more preferably 10,000 or more, particularly preferably 30,000 or more, even more preferably 40,000 or more, and especially preferably 50,000 or more. The upper limit is not particularly limited, but is more preferably 90,000 or less, even more preferably 80,000 or less, and particularly preferably 70,000 or less. The presence of steric hindrance results in relatively large steric hindrance, which can improve dispersibility. The weight-average molecular weight can be determined by known measurement methods such as gel permeation chromatography (GPC) on a polystyrene basis.

[0059] The weight-average molecular weight can be adjusted by changing the conditions (type and amount of monomer, heating conditions, type and amount of catalyst, etc.) when synthesizing amine compounds with a polyester structure.

[0060] The amine compound having a polyester structure preferably has an acid value of 5 to 80 mgKOH / g and an amine value of 5 to 80 mgKOH / g. The acid value is more preferably 10 to 60 mgKOH / g, even more preferably 20 to 50 mgKOH / g, particularly preferably 25 to 45 mgKOH / g, and most preferably 30 to 40 mgKOH / g. The amine value is more preferably 20 to 75 mgKOH / g, even more preferably 30 to 70 mgKOH / g, particularly preferably 35 to 65 mgKOH / g, most preferably 40 to 60 mgKOH / g, and especially preferably 45 to 55 mgKOH / g. When the acid value and amine value are within the above ranges, the amine compound dissolves more easily in aqueous compositions, improving compatibility and thus tending to yield better dispersibility. Furthermore, from a similar viewpoint, the amine value is preferably higher than the acid value, preferably 5 or more higher than the acid value, more preferably 10 or more higher than the acid value, and even more preferably 12 or more higher than the acid value. It is even more preferable that it is 13 to 20 higher.

[0061] The acid value and amine value can be measured using the measurement methods specified in JIS K 2501. The amine value refers to the number of milligrams (mg) of potassium hydroxide (KOH) equivalent to hydrochloric acid or perchloric acid required to neutralize the basic components contained in 1 g of the sample.

[0062] The acid value and amine value can be adjusted by changing the type and amount of acidic or basic groups introduced into the amine compound having a polyester structure, or by changing the type, amount, and ratio of monomers used in the synthesis. For example, they can be changed by adjusting the type and amount of polycarboxylic acid or polyamine used in the synthesis.

[0063] The amine compound having a polyester structure is preferably present in an amount of 0.1 to 50% by mass, more preferably 1 to 45% by mass, even more preferably 5 to 40% by mass, particularly preferably 10 to 35% by mass, even more preferably 15 to 30% by mass, and especially preferably 20 to 25% by mass, based on 100% by mass of metal particles. When the mass is within the above range, a good balance of dispersibility and gloss can be achieved.

[0064] From a similar viewpoint, the amine compound having a polyester structure is preferably present in an amount of 0.01 to 1.00% by mass, more preferably 0.05 to 0.80% by mass, even more preferably 0.10 to 0.60% by mass, particularly preferably 0.15 to 0.40% by mass, and most particularly preferably 0.20 to 0.30% by mass, based on 100% by mass of the pigment composition.

[0065] [Synthesis method] Amine compounds having a polyester structure can be synthesized by known methods. For example, they can be synthesized by reacting cyclic esters such as lactones with polyamines. This reaction can be easily carried out by heating a mixture of cyclic esters such as lactones and polyamines for a certain period of time. The heating temperature is not particularly limited, but for example, 50 to 200°C is preferred, 75 to 160°C is more preferred, and 80 to 120°C is even more preferred. The heating time is particularly While not limited to these, the reaction time is preferably 0.5 to 6 hours, more preferably 1 to 4 hours, and even more preferably 2 to 3 hours. Furthermore, catalysts and solvents such as acid catalysts (e.g., p-toluenesulfonic acid), amine catalysts, and organometallic catalysts may be used during the reaction.

[0066] 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 atoms of the methylene group adjacent to the carbonyl group are substituted with alkyl groups having 1 to 4 carbon atoms.

[0067] Polyamines are not particularly limited as long as they are compounds having two or more functional amino groups. Examples of polyamines include aliphatic diamines and aromatic diamines. Specifically, examples of polyamines include aliphatic diamines such as ethylenediamine, propylenediamine, 2,2-dimethyl-1,3-propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, isophoronediamine, and bicycloheptanediamine, as well as diethylenetriamine, hexylenediamine, triethylenetetramine, and tetraethylenepenta Examples include mine, xylylenediamine, diphenylmethanediamine, hydrogenated diphenylmethanediamine, hydrazine, polyamide polyamine, polyethylene polyimine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, bicycloheptanediamine, mensendiamine, diaminodicyclohexylmethane, isopropylitincyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1,3-bisaminomethylcyclohexane, and the like.

[0068] Amine compounds having a polyester structure containing acidic groups can also be synthesized by known methods. For example, (i) a method of reacting a polymer synthesized from cyclic esters such as lactones and polyamines (lactone-polyamine copolymer) with a polycarboxylic acid, (ii) a method of reacting a polymer synthesized from cyclic esters such as lactones and polycarboxylic acid (lactone-polycarboxylic acid copolymer) with a polyamine, and (iii) a method of reacting a polymer synthesized from cyclic esters such as lactones and polyamines (lactone-polyamine copolymer) with a polymer synthesized from cyclic esters such as lactones and polycarboxylic acid (lactone-polycarboxylic acid copolymer).

[0069] Cyclic esters such as lactones or the lactone copolymers can be readily reacted with polycarboxylic acids or the polycarboxylic acid copolymers. For example, this can be easily done by mixing cyclic esters such as lactones or the lactone copolymers with polycarboxylic acids or the polycarboxylic acid copolymers and heating for a certain period of time while removing water. The heating temperature is not particularly limited, but for example, 100 to 250°C is preferred, 120 to 200°C is more preferred, and 130 to 180°C is even more preferred. The heating time is not particularly limited, but for example, 1 to 10 hours is preferred, 2 to 6 hours is more preferred, and 2 to 3 hours is even more preferred. In addition, catalysts such as p-toluenesulfonic acid, amine catalysts, and organometallic catalysts, as well as solvents, may be used during the reaction.

[0070] Polycarboxylic acids are not particularly limited as long as they are compounds having two or more carboxyl groups. Specific examples of polycarboxylic acids include oxalic acid, succinic acid, tartaric acid, malic acid, citric acid, phthalic acid, isophthalic acid, terephthalic acid, and 2,6-naphthalenedicarbon. Examples include acids and adipic acid.

[0071] 1.2.2 Other Dispersants The pigment composition according to this embodiment may contain, as a dispersant, substances other than the amine compound having the polyester structure described above. Examples of such dispersants include resin dispersants and polyoxyalkylene amine compounds, which do not contain the amine compound having the polyester structure.

[0072] Examples of resin dispersants include (meth)acrylic resins and their salts 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, 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 water-soluble resins include styrene-based resins and their salts, such as lylic acid-(meth)acrylic acid ester copolymers, styrene-maleic acid copolymers, and styrene-maleic anhydride copolymers; urethane-based resins and their salts, which are polymer compounds (resins) containing urethane bonds formed by the reaction of isocyanate groups and hydroxyl groups, and which may be linear and / or branched, with or without crosslinking structures; polyvinyl alcohols; vinylnaphthalene-maleic acid copolymers and their salts; vinyl acetate-maleic acid ester copolymers and their salts; and vinyl acetate-crotonic acid copolymers and their salts.

[0073] Examples of polyoxyalkyleneamine compounds include amine compounds that have a polyoxyalkylene structure within their molecule. Examples of commercially available polyoxyalkyleneamine compounds include JEFFAMIN M2070 (manufactured by Huntsman) and GENAMIN (M41 / 2000) (manufactured by Clariant).

[0074] 1.3 Water The pigment composition according to this embodiment is an aqueous composition containing water as a solvent. In the present invention, "aqueous" means a composition in which the water content in the liquid medium component is 20% by mass or more. The water content is preferably 30 to 100% by mass, more preferably 40 to 90% by mass, and even more preferably 50 to 80% by mass of the liquid medium component. The liquid medium is a solvent component such as water or an organic solvent.

[0075] The water content is preferably 20% by mass or more, more preferably 30-99% by mass, even more preferably 40-90% by mass, and even more preferably 50-80% by mass, based on 100% by mass of the pigment composition.

[0076] It is preferable to use pure or ultrapure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, or distilled water. In particular, water that has been sterilized by ultraviolet irradiation or hydrogen peroxide addition is preferable because it can suppress the growth of mold and bacteria for a long period of time.

[0077] 1.4 Organic Solvents The pigment composition according to this embodiment may contain an organic solvent as a solvent. Examples of organic solvents include esters, alkylene glycol ethers, cyclic esters, nitrogen-containing solvents, alcohols, and polyhydric alcohols. Examples of nitrogen-containing solvents include cyclic amides and acyclic amides. Examples of acyclic amides include alkoxyalkylamides.

[0078] Esters include 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, and diethylene glycol monobutyl ether acetate. Examples include glycol monoacetates such as propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and methoxybutyl acetate, and glycol diesters such as ethylene glycol diacetate, diethylene 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.

[0079] The alkylene glycol ethers can be any monoether or diether of alkylene glycol, with alkyl ethers being preferred. Specific examples include 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 monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol monobutyl ether. Examples include alkylene glycol monoalkyl ethers such as ethyl ether; and alkylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl 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.

[0080] Furthermore, of the alkylene glycols mentioned above, diethers tend to dissolve or swell resins that may be contained in the composition more easily than monoethers, and are therefore preferred in that they can further improve frictional fastness.

[0081] As for cyclic esters, they are as described above, so we will omit further details.

[0082] 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, 3-n-propoxy-N,N-diethylpropionamide Examples include mido, 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, 3-tert-butoxy-N,N-methylethylpropionamide, etc.

[0083] Examples of cyclic amides include lactams, such as pyrrolidones including 2-pyrrolidone, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1-propyl-2-pyrrolidone, and 1-butyl-2-pyrrolidone. These are preferred in that they promote resin film formation, with 2-pyrrolidone being particularly preferred.

[0084] Examples of alcohols include compounds in which one hydrogen atom of an alkane is replaced by a hydroxyl group. The alkane preferably has 10 or fewer carbon atoms, more preferably 6 or fewer, and even more preferably 3 or fewer. The alkane has 1 or more carbon atoms, preferably 2 or more. The alkane may be linear or branched. Examples of alcohols include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert-butanol, iso-butanol, n-pentanol, 2-pentanol, 3-pentanol, and tert-pentanol, 2-phenoxyethanol, benzyl alcohol, and phenoxypropanol.

[0085] When a pigment composition contains alcohols, it is more preferable to select from aromatic monohydric alcohols or aliphatic monohydric alcohols with four or more carbon atoms. Such alcohols are water-soluble but have slightly high hydrophobicity, thus exhibiting good affinity with specific surface treatment agents applied to the metal particle surface. Therefore, they tend to improve the dispersibility of base metal pigments in water-based pigment compositions.

[0086] Aromatic monohydric alcohols are monohydric alcohols having an aromatic ring, such as a benzene ring or a naphthalene ring. In aromatic monohydric alcohols, the number of carbon atoms in the alkylene skeleton to which the hydroxyl group is bonded is preferably 1 to 4, and more preferably 1 to 3. Of the aliphatic monohydric alcohols having 4 or more carbon atoms, those with 4 to 10 carbon atoms are preferred, and those with 4 to 8 carbon atoms are more preferred.

[0087] 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, based on the total mass of the pigment composition. Furthermore, it 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. Furthermore, it is preferable that the content of aromatic monohydric alcohols and / or aliphatic monohydric alcohols having 4 or more carbon atoms be within the above range relative to the total mass of liquid media components contained in the pigment composition.

[0088] Polyhydric alcohols are molecules that contain two or more hydroxyl groups. Polyhydric alcohols can be further classified into, for example, alkanediols and polyols.

[0089] Alkanediols include, for example, compounds in which an alkane is substituted with two hydroxyl groups. Examples of alkanediols include ethylene glycol (also known as ethane-1,2-diol), propylene glycol (also known as propane-1,2-diol), 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 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, and 2 Examples include 4-pentanediol, 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, and 2-methyl-2-propyl-1,3-propanediol.

[0090] Examples of polyols include condensates formed by the intermolecular condensation of two or more alkanediol molecules via hydroxyl groups, and compounds having three or more hydroxyl groups.

[0091] Examples of condensates formed by the intermolecular condensation of two or more alkanediol molecules at their hydroxyl groups include dialkylene glycols such as diethylene glycol and dipropylene glycol, and trialkylene glycols such as triethylene glycol and tripropylene glycol.

[0092] Compounds having three or more hydroxyl groups are compounds with an alkane or polyether structure as their backbone and containing three or more hydroxyl groups. Examples of compounds having three or more hydroxyl groups include glycerin, trimethylolethane, trimethylolpropane, 1,2,5-hexanetriol, 1,2,6-hexanetriol, pentaerythritol, and polyoxypropylenetriol.

[0093] The content of polyhydric alcohols is preferably 1 to 40% by mass, more preferably 3 to 35% by mass, and even more preferably 10 to 30% by mass, based on the total mass of the pigment composition.

[0094] The above organic solvents may be used individually or in combination of two or more.

[0095] The content of the organic solvent is preferably 1% by mass or more, more preferably 5% by mass or more, and particularly preferably 10% by mass or more, based on the total mass of the pigment composition. Furthermore, it is even more preferably 20% by mass or more, and even more preferably 30% by mass or more. The upper limit is preferably 60% by mass or less, preferably 50% by mass or less, and more preferably 40% by mass or less. Furthermore, it is preferable that the content of the organic solvent be within the above range relative to the total mass of the liquid medium components contained in the pigment composition.

[0096] 1.5 Other ingredients The pigment composition according to this embodiment may contain components other than those described above. Examples of such components include leveling agents, binders, polymerization accelerators, polymerization inhibitors, photopolymerization initiators, surfactants, penetration enhancers, humectants, colorants, fixatives, fungicides, preservatives, antioxidants, chelating agents, thickeners, sensitizers, and the like.

[0097] Any resin can be used as a binder, but acrylic resins, polyester resins, urethane resins, cellulose resins, etc. are preferred. Acrylic resins are acrylic The resin is obtained by polymerizing at least monomers, and may be a copolymer resin of acrylic monomer and other monomers. Examples of other monomers include vinyl monomer.

[0098] Preferred surfactants include silicone-based surfactants and acetylene glycol-based surfactants.

[0099] 2. Coloring method A coloring method according to one embodiment of the present invention is a coloring composition in which the above-mentioned pigment composition is a coloring composition, and comprises the step of attaching the coloring composition to an object to be colored.

[0100] According to the coloring method of this embodiment, since the above-mentioned pigment composition is used as the coloring composition, good dispersibility and gloss of the object to be colored can be achieved.

[0101] The shape of the object to be colored is not particularly limited and may be any form, such as a sheet, plate, or object. The material of the object to be colored is also arbitrary and may include, for example, paper, fabric, plastic, metal, glass, ceramics, or wood. Furthermore, the object to be colored can be anything that undergoes coloring, and is not limited to recording media.

[0102] The method of application to the object to be colored is not limited and can be performed by brush application, roller application, spray application, bar coater application, inkjet application, etc. The viscosity of the coloring composition can be selected by changing the type and concentration of components according to the application method.

[0103] The coloring method may include pretreatment steps and drying steps for the object to be colored. Including such steps may result in better gloss for the object to be colored.

[0104] 3. 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 refers to mass.

[0105] 3.1 Synthesis of Dispersants Of the dispersants listed in Tables 1-7 below, polylactone-amines 1-6 and polyesters are included. Polycarboxylic acids were synthesized by the following method.

[0106] [Polylactone-amine 1] 159 g of ε-caprolactone and 21 g of succinic acid were mixed. The mixture was heated under reduced pressure at 80°C for 1 hour to remove water. The mixture was heated to 160°C, 0.9 g of p-toluenesulfonic acid was added as a catalyst, and the mixture was heated for 2 hours. In this way, a polycarboxylic acid-added caprolactone polymer was obtained.

[0107] Next, 11.8 g of tetraethylenepentaamine was mixed with 88.2 g of the polycarboxylic acid-added caprolactone polymer obtained above, and the mixture was heated at 80°C for 2 hours. In this way, a polyamine polycarboxylic acid-added caprolactone polymer was obtained in which the polycarboxylic acid-added caprolactone polymer and tetraethylenepentaamine were bonded together.

[0108] The acid value, amine value, and volume-average molecular weight of the obtained polyamine polycarboxylic acid-added caprolactone polymer were measured. The amounts of ε-caprolactone, succinic acid, and tetraethylenepentaamine used in each step were adjusted to obtain polylactone-amine 1, resulting in an acid value of 35 mg KOH / g, an amine value of 50 mg KOH / g, and a volume-average molecular weight of 60,000.

[0109] [Polylactone-amines 2-6] In polylactone-amine 1, the amounts of ε-caprolactone, succinic acid, and tetraethylenepentaamine used in each step were adjusted to obtain polylactone-amines 2 to 6, so that the acid value, amine value, and volume-average molecular weight were as follows. • Polylactone-amine 2 (acid value 45 mg KOH / g, amine value 45 mg KOH / g, volume average molecular weight 60,000) • Polylactone-amine 3 (acid value 60 mg KOH / g, amine value 30 mg KOH / g, volume average molecular weight 60,000) • Polylactone-amine 4 (acid value 35 mg KOH / g, amine value 50 mg KOH / g, volume-average molecular weight 5000) • Polylactone-amine 5 (acid value 45 mg KOH / g, amine value 45 mg KOH / g, volume average molecular weight 5000) • Polylactone-amine 6 (acid value 60 mg KOH / g, amine value 30 mg KOH / g, volume-average molecular weight 5000)

[0110] [Polyester polycarboxylic acid] A carboxylic acid-terminated caprolactone polymer, which is part of the synthesis process for polylactone-amine 1, was used.

[0111] 3.2 Preparation of Pigment Composition A release layer was formed on a 20 μm PET substrate by coating it with a release resin solubilized with acetone using a roll coater. 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 prepared 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, obtaining an aluminum pigment peeling solution. Next, after removing the tetrahydrofuran with a centrifuge, an appropriate amount of diethylene glycol diethyl ether was added to obtain an aluminum particle suspension with an aluminum concentration of 5% by mass.

[0112] The aluminum particle suspension was ground by stirring using a bead mill until the desired average particle size was achieved, obtaining an aluminum particle suspension with an inkjet-ready particle size (volume average particle size D50 = 0.5 μm or less). In Examples 46 to 53, the suspension was ground to achieve the average particle size of the base metal pigments listed in Table 7 below.

[0113] After the grinding process, Jeffamine M-2070 was added as a poly(oxyethylene / oxypropylene)amine dispersant to an aluminum concentration ratio of 5%, and heat treatment was performed at 55°C for 1 hour under 40kHz ultrasonic irradiation to break down agglomeration and disperse the aluminum particles down to the primary particles.

[0114] A surface treatment agent was added to a suspension of aluminum particles dispersed down to the primary particle level, in the amounts listed in Tables 1-7 below. Subsequently, a dispersion of surface-treated aluminum pigment was obtained by heat treatment at 55°C for 3 hours under 40kHz ultrasonic irradiation.

[0115] The solvent was removed from the obtained aluminum pigment dispersion by centrifugation, and the dispersant was mixed so that the mass ratio of the dispersant to the aluminum pigment was as shown in Tables 1 to 7 for each example. Water was then added to replace the solvent with an aqueous solvent so that the aluminum pigment content was 20% by mass, and the mixture was stirred to obtain the pigment composition corresponding to each example. This pigment composition may be used as a pigment dispersion for preparing coloring compositions, or this pigment composition may be used as a coloring composition for paints and the like.

[0116] Furthermore, analysis of the solvent removed from the dispersion of surface-treated aluminum pigment after surface treatment revealed that no surface treatment agent was present in any of the examples. Therefore, it is presumed that the surface treatment agents in each of the examples in Tables 1-7 below are adhering to the metal particles contained in the composition.

[0117] Next, water, organic solvents, etc., were added to the above-mentioned pigment composition to obtain the pigment compositions for each example and comparative example, according to Tables 1 to 7 below. These pigment compositions are for coloring. These pigment compositions were used in the evaluation described later.

[0118] [Table 1]

[0119] [Table 2]

[0120] [Table 3]

[0121] [Table 4]

[0122] [Table 5]

[0123] [Table 6]

[0124] [Table 7]

[0125] Further explanation is provided regarding the descriptions in Tables 1-7 above. [Base metal pigments] In the table, "Particle Size D50" refers to the volume-average particle size D50, which was measured using a Microtrac MT-3300 (Microtrac-Bell, a laser diffraction / scattering particle size distribution analyzer). Furthermore, the average thickness of the base metal pigment in each example and comparative example was 15 nm. This was measured using atomic force microscopy with NanoNaviE-Sweep (manufactured by SII Nanotechnology Co., Ltd.), and the average value was calculated by measuring 50 arbitrary base metal pigments.

[0126] [Surface treatment agent] In the following explanation, the compound represented by formula (1) or formula (2) is referred to as a specific surface treatment agent. (R 1 -)P(O)(OH)2···(1) (R 2 -O-)a P(O)(OH) 3-a ...(2) (In the formula, R 1 , R 2 (a is 1 or 2.) • Octadecyl (C 18 H 37 )Phosphonic acid: A specific surface treatment agent represented by formula (1), "Product Code: O0371" manufactured by Tokyo Chemical Industry Co., Ltd. was used. • Octadecyl (C 18 H 37 ) Phosphoric acid: A specific surface treatment agent represented by formula (2), a 1:1 mixed product of mono-isomer (a = 1) and di-isomer (a = 2), manufactured by SC Organic Chemicals Co., Ltd., called "Phoslex The "A-18" was used. Dodecyl (C 12 H 25 )Phosphonic acid: A specific surface treatment agent represented by formula (1), "Product Code: D4809" manufactured by Tokyo Chemical Industry Co., Ltd. was used. Tridecyl (C) 13 H 27 )Phoslex: A specific surface treatment agent represented by formula (2), "Phoslex A-13" manufactured by SC Organic Chemicals Co., Ltd., which is a 1:1 mixture of mono and di forms, was used. Dodecyl (C 12 H 25 ) Phosphate: A specific surface treatment agent represented by formula (2), mono-body / di-body We used "Phoslex A-12," a 1:1 mixture product manufactured by SC Organic Chemicals Co., Ltd. Octyl (C8H) 17 )Phosphonic acid: Not classified as a specific surface treatment agent, so "Product Code: O0380" manufactured by Tokyo Chemical Industry Co., Ltd. was used. • FHP: Not a specified surface treatment agent; 2-(perfluorohexyl)ethylphosphonic acid, manufactured by Unimatec.

[0127] [Dispersant] • Polycarboxylate amine: Product name "Disparon 1831", manufactured by Kusumoto Kasei Co., Ltd. • Polyetheramine: Product name "T5000", manufactured by Mitsui Chemicals, Inc.

[0128] 3.3 Evaluation Method [Dispersibility] For each example and comparative example, a portion of a 5% by mass suspension of a base metal pigment containing 20kHz sonicated diethylene glycol diethyl ether, obtained during the manufacturing process of the aqueous composition, was taken out. To this, Esream AD-374M (manufactured by 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 (manufactured by Microtrac-Bell, a laser diffraction / scattering particle size distribution analyzer). This volume-average particle diameter D50 of the metal particles contained in the dispersion was used as the reference value.

[0129] In each example and comparative example, 100 ml of the final aqueous composition was placed in a glass container, sealed, and left at room temperature for one month. After standing, the container was shaken 10 times, and the volume-average particle size 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 size D50 of the metal particles contained in the aqueous composition to the reference value, the better the dispersibility (redispersibility) of the metal particles. A score of C or higher was considered a good level. The reference value was set to 100%. In the case where the average particle size of the metal particles was 3 μm or more, sedimentation of the metal particles was observed after standing for one month, but the dispersibility was evaluated after the metal particles were redispersed by shaking the container as described above. (Evaluation Criteria) A: The ratio of D50 metal particles contained in the aqueous composition to the standard value is less than 110%. B: The ratio of D50 metal particles contained in the aqueous composition to the standard value is 110% or more and less than 150%. C: The ratio of D50 metal particles contained in the aqueous composition to the standard value is 150% or more and less than 200%. D: The ratio of D50 metal particles contained in the aqueous composition to the standard value is 200% or more and less than 500%. E: The ratio of D50 metal particles contained in the aqueous composition to the standard value is 500% or more.

[0130] [Glossy] A modified Seiko Epson SC-S80650 was used to create recordings for each example. The inkjet head nozzle density was set to 360 npi and 360 nozzles. The pigment composition for each example was loaded into the inkjet head. The inkjet head drive waveform was optimized to ensure optimal ejection. A polyvinyl chloride film (Mactac5829R, manufactured by Mactac) was used as the recording medium. The ink adhesion amount in the recording pattern during recording was 5 mg / inch 2 The recording resolution was set to 1440 x 1440 dpi. In Examples 46-53, the coating was applied using a bar coater to achieve the same amount of coating as described above. These examples are suitable as paints.

[0131] For the printed portion of each example's record, a MINOLTA MULTI GLO gloss meter was used. Using SS 268, the gloss level was measured at a tilt angle of 60° and evaluated according to the following criteria. A higher value indicates better gloss. A score of C or higher was considered good. (Evaluation Criteria) A: Glossiness level of 400 or higher. B: Glossiness level is between 350 and 400. C: Glossiness level is between 300 and 350. D: Glossiness is between 250 and 300. E: Glossiness is less than 250.

[0132] 〔water resistance〕 Each example pigment composition was sealed in a pack and left in a 70°C constant temperature bath for 6 days. The amount of gas generated per unit mass of the composition was determined, and the water resistance was evaluated according to the following criteria. A lower amount of generated gas indicates better water resistance. A score of C or higher was considered a good level. (Evaluation Criteria) A: The amount of gas generated is less than 0.2 mL / g. B: Gas generation amount is 0.2 mL / g or more but less than 0.4 mL / g. C: Gas generation amount is 0.4 mL / g or more but less than 1.0 mL / g. D: Gas generation amount is 1.0 mL / g or more and less than 5.0 mL / g. E: Gas generation amount is 5.0 mL / g or more.

[0133] 3.4 Evaluation Results The evaluation results are shown in Tables 1-7 above.

[0134] As shown in Tables 1 to 7 above, each embodiment of the present invention, which contains a base metal pigment, a dispersant, and water, wherein the base metal pigment is metal particles whose surface is treated with a compound represented by formula (1) or formula (2) above, and the dispersant is an amine compound having a polyester structure and is water-based, showed good dispersibility and gloss.

[0135] A comparison of Examples 1-6 and Comparative Examples 1-3 showed that a dispersant containing an amine compound having a polyester structure could achieve both dispersibility and gloss, as well as good water resistance.

[0136] A comparison of Examples 7-30 and Comparative Examples 4-15 showed that when the base metal pigment was metal particles surface-treated with a specific surface treatment agent, both dispersibility and gloss could be achieved. Furthermore, water resistance tended to be improved.

[0137] The results from Examples 1-6 showed that amine compounds with a polyester structure tended to exhibit superior dispersibility, gloss, and water resistance when their molecular weight was higher. Furthermore, amine compounds with a polyester structure tended to exhibit superior dispersibility, gloss, and water resistance when their acid value and amine value were within a specific range.

[0138] The results from Examples 1 to 30 showed that various specific surface treatment agents could achieve both dispersibility and gloss. Furthermore, when the number of carbon atoms in the hydrocarbon group of the specific surface treatment agent was higher, dispersibility, gloss, and water resistance tended to be better.

[0139] The results from Examples 1 and 7, and Examples 31 to 34, showed that when the content of a specific surface treatment agent relative to metal particles was within a specific range, dispersibility, gloss, and water resistance tended to be better.

[0140] The results from Examples 1 and 35-37 show that both dispersibility and gloss can be achieved regardless of the solvent composition.

[0141] The results from Examples 1, 4, 7, and 10, and Examples 38-45, showed that when the content of the dispersant relative to the metal particles was within a specific range, the dispersibility and gloss tended to be better.

[0142] The results from Examples 1, 4, 7, and 10, and Examples 46-53, showed that when the volume-average particle size D50 of the base metal pigment was less than 9 μm, the dispersibility tended to be superior.

[0143] The following conclusions can be drawn from the embodiments described above.

[0144] One aspect of the pigment composition is: It contains a base metal pigment, a dispersant, and water. The base metal pigment is a metal particle whose surface has been treated with a compound represented by formula (1) or formula (2). The dispersant comprises an amine compound having a polyester structure. It is a water system. (R 1 -)P(O)(OH)2···(1) (R 2 -O-) a P(O)(OH) 3-a ...(2) (In the formula, R 1 , R 2 (a is 1 or 2.)

[0145] In one embodiment of the above pigment composition, The amine compound having the polyester structure may also be an amine compound having a polylactone structure.

[0146] In any embodiment of the above pigment composition, The amine compound having the polyester structure may have a weight-average molecular weight of 3,000 to 100,000.

[0147] In any embodiment of the above pigment composition, The amine compound having the polyester structure may have an acid value of 5 to 80 mgKOH / g and an amine value of 5 to 80 mgKOH / g.

[0148] In any embodiment of the above pigment composition, The amine compound having the polyester structure may be present in an amount of 0.1 to 50% by mass relative to 100% by mass of the metal particles.

[0149] In any embodiment of the above pigment composition, The compound represented by formula (1) or formula (2) may be present in an amount of 1 to 50% by mass relative to 100% by mass of metal particles.

[0150] In any embodiment of the above pigment composition, The aforementioned metal particles may consist of aluminum or an aluminum alloy.

[0151] In any embodiment of the above pigment composition, The volume-average particle size D50 of the base metal pigment may be 3 to 15 μm.

[0152] In any embodiment of the above pigment composition, The volume-average particle size D50 of the base metal pigment may be 1 μm or less.

[0153] In any embodiment of the above pigment composition, The compound represented by formula (1) or formula (2) is R in formula (1). 1 or the above formula (2 ) R 2 However, it may also be a hydrocarbon group having 15 to 30 carbon atoms.

[0154] In any embodiment of the above pigment composition, The metal particles may be in the form of flakes.

[0155] One method of coloring is: A pigment composition according to any of the above embodiments is a coloring composition, and the method comprises the step of attaching the coloring composition to an object to be colored.

[0156] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes configurations that are substantially identical to the configurations described in the embodiments, for example, configurations that have the same function, method and result, or configurations that have the same purpose and effect. The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as the configurations described in the embodiments. Furthermore, the present invention includes configurations that add known technology to the configurations described in the embodiments.

Claims

1. It contains a base metal pigment, a dispersant, water, and an organic solvent. The base metal pigment is a metal particle whose surface has been treated with a compound represented by formula (1) or formula (2). The dispersant comprises an amine compound having a polyester structure. The aforementioned organic solvent includes one or more alcohols and polyhydric alcohols. The aforementioned alcohols include monohydric alcohols having an aromatic ring. The aforementioned polyhydric alcohols include 1,2-hexanediol, A water-based pigment composition. (R １ -)P(O)(OH) ２ ・・・(1) (R ２ -O-) ａ P(O)(OH) ３－ａ ・・・(2) (In the formula, R １ , R ２ (a is 1 or 2.)

2. The pigment composition according to claim 1, wherein the amine compound having the polyester structure is an amine compound having a polylactone structure.

3. The pigment composition according to claim 1 or claim 2, wherein the amine compound having the polyester structure has a weight-average molecular weight of 3,000 to 100,000.

4. The pigment composition according to any one of claims 1 to 3, wherein the amine compound having the polyester structure has an acid value of 5 to 80 mgKOH / g and an amine value of 5 to 80 mgKOH / g.

5. The pigment composition according to any one of claims 1 to 4, wherein the amine compound having the polyester structure is present in an amount of 0.1 to 50% by mass based on 100% by mass of metal particles.

6. The pigment composition according to any one of claims 1 to 5, wherein the compound represented by formula (1) or formula (2) is present in an amount of 1 to 50% by mass with respect to 100% by mass of metal particles.

7. The pigment composition according to any one of claims 1 to 6, wherein the metal particles consist of aluminum or an aluminum alloy.

8. The pigment composition according to any one of claims 1 to 7, wherein the volume average particle size D50 of the base metal pigment is 3 to 15 μm.

9. The pigment composition according to any one of claims 1 to 7, wherein the volume average particle diameter D50 of the base metal pigment is 1 μm or less.

10. The compound represented by the formula (1) or formula (2) has R in the formula (1) １ or R in the formula (2) ２ being a hydrocarbon group having 15 to 30 carbon atoms, and the pigment composition according to any one of claims 1 to 9

11. The pigment composition according to any one of claims 1 to 10, wherein the metal particles are in the form of flakes.

12. A coloring method comprising the step of applying the coloring composition to an object to be colored, wherein the pigment composition according to any one of claims 1 to 11 is a coloring composition.

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