Composite pigment

Abstract

To provide a composite pigment enabling unconventional distinctive coloring.SOLUTION: This composite pigment comprises metal flakes and a colored pigment deposited on at least a portion of the surface of the metallic flakes. The colored pigment has an average ratio of the major axis to the minor axis of 1.60 to 100.SELECTED DRAWING: None

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates generally to composite pigments, and more particularly to composite pigments having pigments deposited on metal flakes. [Background technology]

[0002] Color pigments have small primary particle diameters and are prone to re-aggregation, making their color development prone to change. For this reason, in JP-A-5-214257 (Patent Document 1), the color development is stabilized by coating the surface of flaky particles that are larger than the color pigment with the color pigment. Such composite pigments are suitable for use in cosmetics because the fine color pigment particles are less likely to remain on the skin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-214257 Summary of the Invention [Problem to be solved by the invention]

[0004] However, although the method described in Patent Document 1 stabilizes the color development of color pigments, it is not sufficient to meet the growing demand for a variety of color tones in recent years.

[0005] Therefore, an object of the present invention is to provide a composite pigment that can produce a unique color that has not been previously available. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors have found that controlling the shape of the color pigment attached to the surface of metal flakes makes it possible to produce unique colors that have not been seen before. Based on this finding, the present invention is configured as follows.

[0007] The composite pigment according to the present invention comprises metal flakes and a color pigment attached to at least a portion of the surface of the metal flakes, the color pigment having an average ratio of the major axis to the minor axis of 1.60 or more and 100 or less.

[0008] In this way, it is possible to provide a composite pigment that can produce a unique color that has not been previously available. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a scanning electron microscope photograph of the composite particles of Example 1. [Figure 2] FIG. 1 is a view showing a scanning electron microscope photograph of the composite particles of Example 2. [Figure 3] FIG. 2 is a view showing a scanning electron microscope photograph of the composite particles of Comparative Example 1. [Figure 4] FIG. 1 is a view showing a scanning electron microscope photograph of the composite particles of Example 3. [Figure 5] FIG. 1 is a view showing a scanning electron microscope photograph of the composite particles of Comparative Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0010] The composite pigment of the present invention will be described in detail below with reference to specific examples. Note that the present invention is not limited to the following embodiments, and various modifications are possible within the scope of the technical concept of the present invention.

[0011] <Composite pigment> The composite pigment according to the present invention comprises metal flakes as the metal pigment and a color pigment attached to at least a portion of the surface of the metal flakes. The color pigment attached to the metal flakes has an average ratio of the major axis to the minor axis of 1.60 or more and 100 or less. The composition of the composite pigment will be described below.

[0012] <Metal flakes> The metal flakes used as the metallic pigment may consist of metal only, or may have a surface coated with a light-transmitting material, or may be flakes in which the surface of a core material made of a material other than metal is coated with metal.

[0013] The aspect ratio of metal flakes is the ratio of the volume average particle diameter D to the average thickness. 50 The aspect ratio of the metal flakes is preferably 2 or more and 200 or less, and more preferably 40 or more and 100 or less. If the aspect ratio is less than 2, there is a risk that the flakes will not be uniformly oriented when applied, resulting in poor color development, and if the aspect ratio is greater than 200, there is a risk that the flakes will break when mechanical shear is applied during processing, resulting in poor color development.

[0014] The average particle diameter D of the metal flakes used in the present invention 50 The average particle size is preferably 5 μm or more and 500 μm or less, and more preferably 10 μm or more and 300 μm or less. If the average particle size is less than 5 μm, the ratio of the corners to the surface of one metal flake becomes high, which may cause light scattering and result in poor color development, and if the average particle size is more than 500 μm, the flakes may break if mechanical shear is applied during processing, which may result in poor color development.

[0015] The metal constituting the metal flakes is not particularly limited and any known metal can be used, but at least one selected from the group consisting of (a) aluminum, copper, nickel, tin, titanium, and zinc, (b) an alloy containing at least one of the above (a), and (c) stainless steel is preferably used. Among these, aluminum or an aluminum alloy is particularly preferably used because it is inexpensive and has high brightness.

[0016] When the surface of the metal flakes is coated with a translucent material, any known translucent material can be used without any particular limitation. Among them, translucent substrates made of silica, alumina, glass, mica, resin, and composites thereof are preferably used because of their high translucency.

[0017] The content of metal flakes relative to the total weight of the composite pigment of the present invention is preferably 10% by weight or more and 99.9% by weight or less, and more preferably 70% by weight or more and 99.5% by weight or less. If the content of metal flakes is less than 10% by weight, the coated surface may become rough when applied, resulting in poor color development and making it difficult to obtain the luster characteristic of metal. If the content of metal flakes is more than 99.9% by weight, the color development of the color pigment will be weak.

[0018] <Coloring pigments> Examples of color pigments that can be used in the composite pigment of the present invention include azo pigments such as Red No. 2, Red No. 3, Red No. 102, Red No. 104, Red No. 105, Red No. 106, Red No. 201, Red No. 202, Red No. 203, Red No. 204, Red No. 226, Yellow No. 4, Yellow No. 5, Orange No. 201, Blue No. 1, Green No. 3, and Black No. 401. Commercially available particles of these color pigments have a small ratio of the long diameter to the short diameter (long diameter / short diameter). However, contacting the color pigment with ammonia or a compound containing an amino group can result in the formation of needle-shaped crystals with a long diameter / short diameter ratio of 1.60 or greater.

[0019] When unevenness is formed on the surface of a metal flake by adhering a color pigment having an average major axis / minor axis ratio of 1.60 to 100, it is possible to exhibit a characteristic color not previously seen. The average major axis / minor axis ratio of the color pigment is preferably 1.60 to 15.0, and more preferably 2.0 to less than 15.0. It is practically difficult to grow color pigment crystals until the average major axis / minor axis ratio exceeds 100. In this specification, the average major axis / minor axis ratio is determined by observing the surface of the composite pigment with a scanning electron microscope, measuring 30 or more randomly selected color pigment crystals, and taking the arithmetic mean of the measurements.

[0020] The coverage of the metal flakes with the color pigment is preferably 10% or more, more preferably 20% or more, as the percentage (%) of the surface of the metal flakes covered with the color pigment relative to the surface area of ​​the metal flakes. In this specification, the coverage is determined by observing the surface of the composite pigment with a scanning electron microscope and calculating the percentage (%) of the area occupied by the color pigment in one field of view relative to the area of ​​a randomly selected field of view on the surface of the composite pigment. If the coverage is less than 10%, the color of the pigment will be weak, and sufficient effect may not be obtained.

[0021] In the composite pigment according to the present invention, other inorganic pigments such as iron oxide and titanium oxide may be attached to the surface of the metal flakes in addition to a color pigment having an average major axis / minor axis ratio of 1.60 or more and 100 or less.

[0022] <Protective layer> The composite pigment of the present invention may be coated with a protective layer, if necessary.

[0023] The material of the protective layer is not particularly limited as long as it is transparent and does not impair the color development of the pigment. Examples of the material for the protective layer include metal oxides, metal hydroxides, metal oxide hydrates, resins, and composites thereof, and may be appropriately selected from these depending on the purpose. As a method for forming the protective layer, known methods for coating pigments can be used.

[0024] By forming the protective layer, the adhesion of the color pigment becomes stronger, and the resistance to the removal of the color pigment and the resistance to elution by water or solvents can be further improved.

[0025] As the protective layer, for example, a metal oxide coating film made of silica, alumina, zirconia, titania, etc. Among them, a metal oxide coating film made of silica or alumina is preferred because it can be easily formed using a sol-gel method and can be produced at low cost.

[0026] The method for coating a composite pigment with a metal oxide coating is not particularly limited, but examples include a method in which a metal oxide coating is precipitated by hydrolyzing an alkoxide of the metal contained in the metal oxide coating using a sol-gel method, a method in which an alkali is added to a metal salt solution of the metal contained in the metal oxide coating to neutralize and precipitate the metal oxide coating, and a method in which a metal powder is contacted with a solution in which an organometallic compound is dissolved in an organic solvent and the metal powder is oxidized by heat treatment to form a metal oxide coating. Among these, it is preferable to form a metal oxide coating by the sol-gel method. The sol-gel method allows for a uniform metal oxide coating.

[0027] The amount of the protective layer is not particularly limited, but is preferably 1 part by weight to 200 parts by weight, and more preferably 10 parts by weight to 100 parts by weight, per 100 parts by weight of the composite pigment before the protective layer is applied. If the amount is less than 1 part by weight, the protective layer cannot be formed over the entire surface of the pigment, and the protective layer's performance cannot be achieved. If the amount is more than 200 parts by weight, the protective layer may be too thick, resulting in poor color development. The amount of the protective layer can be appropriately determined depending on the specific surface area of ​​the metal flakes, the coverage rate of the color pigment, etc.

[0028] <Composite pigment> The particle size of the composite pigment according to the present invention is the average particle size (volume average median diameter) D 50 The particle size is preferably 5 μm or more and 500 μm or less, and more preferably 5 μm or more and 300 μm or less. If the particle size is 5 μm or more, the composite pigment will not remain on the skin, and the covering effect of the composite pigment can be easily obtained, and the glossiness unique to metal flakes can be obtained. On the other hand, if the particle size is too large, it is likely to cause irritation when applied to the skin, so D 50 The average particle diameter D of the composite pigment is preferably 500 μm or less. 50 can be measured as the volume-average median diameter by dispersing the sample in an alcohol solvent and using a laser diffraction particle size distribution analyzer such as the MT3300EXII manufactured by Microtrac.

[0029] The average thickness of the composite pigment according to the present invention is preferably 0.05 μm or more and 250 μm or less, and more preferably 0.5 μm or more and 100 μm or less. A thickness of 0.5 μm or more and 100 μm or less allows for good pigment coating. The average thickness is determined by observing the cross section of the composite pigment with an electron microscope. Specifically, a coating film containing the composite pigment is embedded in epoxy resin, and a surface perpendicular to the coating film is removed by ion milling and observed with a scanning electron microscope. The thicknesses of 10 or more composite particles randomly selected from the obtained image are measured, and the arithmetic mean is calculated.

[0030] The average aspect ratio of the composite pigment (volume average particle diameter D 50 The aspect ratio is preferably 2 or more and 200 or less, and more preferably 40 or more and 100 or less. If the aspect ratio is less than 2, uniform orientation will not be achieved when applied, and if the aspect ratio is greater than 200, the pigment coverage will be poor, which may result in poor color development.

[0031] <Composite pigment manufacturing process> Next, the manufacturing process of the composite pigment according to the present invention will be described. The manufacturing process of the composite pigment can be performed by a wet method or a solid-phase method. The shape of the color pigment can be controlled before or after it is attached to the surface of the metal flakes.

[0032] <Wet method> In the manufacturing process using the wet method, a color pigment and a compound having ammonia or an amino group are dispersed in a solvent to prepare a dispersion (slurry or paste) of the color pigment, and metal flakes are dispersed in the color dispersion to obtain a composite pigment.

[0033] Examples of compounds having an amino group include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, triethanolamine, and silane coupling agents having an amino group.

[0034] Suitable solvents include alcohols, ester solvents, and mixtures thereof. Specific examples include, but are not limited to, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, butanol, normal propyl alcohol, ethyl acetate, butyl acetate, isopropyl acetate, and normal propyl acetate. Furthermore, aliphatic hydrocarbons and aromatic hydrocarbons may be added as needed to prevent elution of color pigments.

[0035] The method for dispersing the color pigment in the solvent is not particularly limited, but examples include dispersion methods using grinding media such as ball mills, bead mills, and sand mills. The dispersion time is also not particularly limited, but a range of 30 minutes to 30 hours is preferred for reasons of the design and productivity of the colorant. The dispersion temperature is also not particularly limited, and may be within the range of 0°C to 100°C.

[0036] In addition to the above-mentioned dispersion methods, suitable dispersion methods for adding metal flakes to a color pigment dispersion and adhering the color pigment to the surface of the metal flakes include stirring with a stirrer or disperser or kneading with a kneader mixer. The dispersion time is not particularly limited, but a range of 30 minutes to 30 hours is preferred for reasons of the degree of dispersion of the color pigment and productivity. The dispersion temperature is also not particularly limited, and may be in the range of 0°C to 100°C.

[0037] <Solid phase method> In the manufacturing process using the solid phase method, metal flakes and colored pigments are mixed by stirring using a dry particle composite device, and then ammonia or a compound having an amino group is dispersed in water or a solvent to obtain a composite pigment.

[0038] The dry particle compositing device may be, for example, Nobilta (registered trademark) NOB (manufactured by Hosokawa Micron Corporation) or Hybridization System (manufactured by Nara Machinery Manufacturing Co., Ltd.) The peripheral speed of the stirring blades of the dry particle compositing device should be in the range of 5 to 60 m / s, which is good for uniformly adhering the color pigment to the surface of the glass flakes.

[0039] Examples of compounds having an amino group include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, triethanolamine, and silane coupling agents having an amino group.

[0040] Suitable solvents include aliphatic hydrocarbons, aromatic hydrocarbons, and mixtures thereof. Specific examples include, but are not limited to, normal paraffin, isoparaffin, toluene, xylene, solvent naphtha, kerosene, mineral spirits, and petroleum benzine. If necessary, a small amount of alcohol may be added to aid in dispersing the color pigment.

[0041] The dispersion method is not particularly limited, but suitable methods include dispersion using a grinding medium such as a ball mill, bead mill, or sand mill, stirring with a stirrer or disperser, and kneading with a kneader mixer. The dispersion time is also not particularly limited, but a range of 1 to 60 minutes is preferred for reasons of the degree of dispersion of the color pigment and productivity. The dispersion temperature is also not particularly limited, and may be in the range of 0 to 100°C.

[0042] <Protective layer> In the metal oxide coating formation process, a preferred method is, for example, to add alkoxysilane and water to a solution in which the composite pigment is dispersed, and adjust the pH value of the solution with a hydrolysis catalyst, thereby hydrolyzing and condensing the alkoxysilane to precipitate silica on the surface of the composite pigment.

[0043] The composite pigment prepared above is dispersed in a non-polar solvent, and a hydrophilic solvent containing silane alkoxide and water, and a base catalyst are gradually added to the solution to hydrolyze and condense the silane alkoxide. This allows a metal oxide coating made of amorphous silica to be formed on the surface of the composite pigment. To promote hydrolysis in the sol-gel method, an acid catalyst may be used to hydrolyze the pigment before adding the base catalyst.

[0044] Examples of silane alkoxides include tetraethoxysilane, tetraethoxysilane condensates, tetraisopropoxysilane, tetraisopropoxysilane condensates, etc. The silane alkoxides described above can be used alone or in combination of two or more.

[0045] Examples of the base catalyst include ammonia, triethylamine, n-butylamine, ethylenediamine, sodium hydroxide, and potassium hydroxide. The base catalyst may be one of the above-described catalysts or a combination of two or more of them. The amount of the base catalyst used is preferably 0.05 to 50 g / L in terms of the content in the solvent.

[0046] <Cosmetics> The composite pigment of the present invention can be blended into cosmetics. Examples of cosmetics that incorporate the composite pigment of the present invention are preferably eye shadow, blush, lip color, etc. By doing so, it is possible to provide cosmetics that stabilize the color development of the color pigment, prevent fine color pigment particles from remaining on the skin, and enable characteristic color development that has not been achieved before.

[0047] The present invention can be summarized as follows.

[0048] (1) A composite pigment comprising metal flakes and a color pigment attached to at least a portion of the surface of the metal flakes, wherein the color pigment has an average ratio of the major axis to the minor axis of 1.60 or more and 100 or less.

[0049] (2) The composite pigment according to (1) above, wherein the color pigment has an average ratio of the major axis to the minor axis of 1.60 or more and 15.0 or less.

[0050] (3) The composite pigment according to (1) or (2) above, wherein the color pigment is an azo pigment.

[0051] (4) A composite pigment according to any one of (1) to (3) above, wherein the coverage rate of the metal flakes with the coloring pigment is 10% or more, in terms of the ratio (%) of the surface area of ​​the metal flakes covered with the coloring pigment to the surface area of ​​the metal flakes.

[0052] (5) Average particle diameter D 50 The composite pigment according to any one of (1) to (4) above, wherein the particle size is 5 μm or more.

[0053] (6) A composite pigment according to any one of (1) to (5) above, having an average thickness of 0.05 μm or more and 250 μm or less.

[0054] (7) A composite pigment according to any one of (1) to (6), wherein the metal flakes are coated with a translucent material.

[0055] (8) The composite pigment according to any one of (1) to (7) above, wherein the metal flakes are at least one selected from the group consisting of (a) aluminum, copper, nickel, tin, titanium, and zinc, (b) an alloy containing at least one of the above (a), and (c) stainless steel.

[0056] (9) A cosmetic comprising the composite pigment according to any one of (1) to (8) above. [Example]

[0057] The composite pigment according to the present invention will be described in more detail below by showing specific production examples and test results.

[0058] Example 1 (Process 1) 4.5 g of commercially available Red No. 202 (SUNCROMA (registered trademark) D&C RED7 CALAKE, manufactured by DIC Corporation) as a color pigment and 15 g of silica-coated aluminum flakes (manufactured by Toyo Aluminum Co., Ltd., average particle diameter 18 μm) as metal flakes were mixed with a glass rod. Next, using a dry particle compositer, the mixture was stirred and mixed for 5 minutes at a motor power load per unit weight of approximately 4 W / g to obtain a colored aluminum flake pigment.

[0059] (Process 2) 15 g of the resulting colored aluminum flake pigment was dispersed in 30 g of isopropyl alcohol and 220 g of ion-exchanged water, and 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane was added. The mixture was then stirred for approximately 5 minutes. This was subjected to solid-liquid separation using a filter, yielding a composite pigment in which needle-shaped crystals of the colored pigment adhered to the metal flakes. The composite pigment of Example 1 exhibited a bluish red color when viewed from any angle.

[0060] The obtained composite pigment was photographed at 20,000x magnification using a scanning electron microscope JSM-5510 (manufactured by JEOL Ltd.) (Figure 1). Using image software (WinLOOF), 30 or more points of the colored pigment attached to the surface of the metal flakes were taken from one field of view (white frame in Figure 1), and the ratio of the long diameter to the short diameter of each was measured and the average value was calculated. The average long diameter / short diameter ratio was 4.12. Furthermore, the coverage of the metal flakes was measured as the ratio (%) of the surface area of ​​the metal flakes covered by the colored pigment to the surface area of ​​the metal flakes within one field of view (white frame in Figure 1) of the above scanning electron microscope photograph, and was 81%. The average particle diameter D of the composite particles was 50 The major axis / minor axis ratio of the color pigment of the obtained composite pigment, the coverage rate (%) of the metal flake surface with the color pigment, and the average particle diameter D of the composite pigment were 50 The average thickness was measured in the following examples and comparative examples in the same manner.

[0061] <Example 2> 15 g of the colored aluminum flake pigment obtained in step 1 of Example 1 was dispersed in 120 g of isoparaffin, and 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane was added. A mixture of 20 g of isopropyl alcohol and 8.0 g of tetraethoxysilane (TEOS) was then added over 20 minutes. At the same time, a mixture of 10 g of ion-exchanged water, 1.2 g of 25% ammonia water, and 86 g of isopropyl alcohol was added over approximately 70 minutes. The temperature of the system was then raised to 75°C, and 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane and 5.5 g of tetraethoxysilane (TEOS) were added and stirred for 120 minutes. The resulting colored aluminum flake pigment slurry was subjected to solid-liquid separation using a filter and powdered using a dryer to obtain a composite pigment in which needle-shaped crystals of the colored pigment adhered to the metal flakes.

[0062] The composite pigment of Example 2 exhibited a bluish red color when viewed from any angle. A scanning electron microscope photograph of the composite pigment of Example 2 taken in the same manner as in Example 1 is shown in FIG.

[0063] The composite pigment of Example 2 has an average major axis / minor axis ratio of 4.35, a coverage rate of the metal flake surface by the color pigment of 70%, and an average particle diameter D 50 The average thickness of the composite pigment was 1.4 μm.

[0064] <Comparative Example 1> 28 g of Red No. 202 (DIC Corporation: SUNCROMA (registered trademark) D&C RED 7CALAKE) was dispersed in 75 g of isopropyl alcohol in a pot mill, and 1.5 mm zirconia balls were added and the mixture was milled at 100 rpm for 4 hours. 10 g of this color pigment slurry was mixed with 15 g of silica-coated aluminum flakes in a disperser to obtain a composite pigment in which the color pigment was adhered to the metal flakes.

[0065] The composite pigment of Comparative Example 1 exhibited a red color when viewed from any angle. A scanning electron microscope photograph of the composite pigment of Comparative Example 1 taken in the same manner as in Example 1 is shown in FIG.

[0066] The composite pigment of Comparative Example 1 had an average major axis / minor axis ratio of 1.56, a coverage rate of the metal flake surface by the color pigment of 35%, and an average particle diameter D 50 The average thickness of the composite pigment was 1.1 μm.

[0067] Example 3 A colored copper flake pigment was obtained in the same manner as in Step 1 of Example 1, except that 40 g of copper flakes ground to an average particle size of 16 μm were used as the metal flakes and 1.6 g of Red No. 202 were used as the colored pigment. 40 g of the resulting colored copper flake pigment was dispersed in 120 g of isoparaffin, and 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane was added. A mixture of 20 g of isopropyl alcohol and 4.4 g of tetraethoxysilane (TEOS) was then added over 20 minutes. Simultaneously, a mixture of 10 g of ion-exchanged water, 1.2 g of 25% ammonia water, and 86 g of isopropyl alcohol was added over approximately 70 minutes. The temperature of the system was then raised to 75°C, and 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane and 2.8 g of tetraethoxysilane (TEOS) were added, followed by stirring for 120 minutes. The slurry of the colored copper flake pigment obtained above was subjected to solid-liquid separation using a filter and powdered using a dryer to obtain a composite pigment in which needle-like crystals of the colored pigment were attached to the metal flakes.

[0068] The composite pigment of Example 3 exhibited a bluish red color when viewed from any angle. A scanning electron microscope photograph of the composite pigment of Example 3 taken in the same manner as in Example 1 is shown in FIG.

[0069] The composite pigment of Example 3 had an average major axis / minor axis ratio of 3.47, a coverage rate of the metal flake surface by the color pigment of 59%, and an average particle diameter D 50 The average thickness of the composite pigment was 1.0 μm.

[0070] <Comparative Example 2> 0.8 g of commercially available Red No. 202 (DIC Corporation: SUNCROMA (registered trademark) D&C RED7 CALAKE) was mixed with 20 g of copper flakes crushed to an average particle size of 16 μm using a glass rod. The mixture was then stirred and mixed for 5 minutes using a dry particle compositer at a motor power load of approximately 2.5 W / g per unit weight to obtain a composite pigment in which the color pigment was attached to the metal flakes.

[0071] The composite pigment of Comparative Example 2 exhibited a red color when viewed from any angle. A scanning electron microscope photograph of the composite pigment of Comparative Example 2 taken in the same manner as in Example 1 is shown in FIG.

[0072] The composite pigment of Comparative Example 2 was confirmed to have an average major axis / minor axis ratio of 1.44, a coverage rate of the metal flake surface by the color pigment of 55%, and an average particle diameter D 50 The average thickness of the composite pigment was 1.0 μm.

[0073] <Color measurement> 1.0 g of the composite pigment of each Example and Comparative Example and 9.0 g of Autoclear Super (manufactured by Nippon Paint Co., Ltd.) were placed in a PP cup and stirred for 120 seconds using a Mazerustar (manufactured by Kurabo Industries, Ltd.) under conditions of 9 rotations and 9 revolutions. The resulting paint was applied to coated paper using a 9-mil doctor blade. The coating film was dried and colorimetrically measured using a BYK-Maci (manufactured by BYK-Gardner). The results are shown in Table 1.

[0074] [Table 1]

[0075] As shown in Table 1, when comparing the aluminum flakes of Example 1, Example 2, and Comparative Example 1, b * The values ​​are very different. * a * b * At the value of b * The smaller the value, the stronger the blueness, and therefore it can be seen that in Examples 1 and 2, both the highlights and shades have a strong bluish tone.

[0076] In addition, when comparing Example 3 and Comparative Example 2, Example 3 has a higher b * The values ​​are smaller overall, indicating an increase in blueness.

[0077] The embodiments and examples disclosed above should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and includes all modifications within the meaning and scope of the claims.

Claims

1. Metal flakes; a color pigment adhered to at least a portion of the surface of the metal flakes; The color pigment is a composite pigment having an average ratio of the major axis to the minor axis of 1.60 or more and 100 or less.

2. The composite pigment according to claim 1 , wherein the color pigment has an average ratio of the major axis to the minor axis of 1.60 or more and 16.0 or less.

3. The composite pigment according to claim 1 , wherein the color pigment is an azo pigment.

4. 2. The composite pigment according to claim 1, wherein the coverage of the metal flakes with the color pigment is 10% or more, in terms of the percentage of the surface of the metal flakes that is covered with the color pigment relative to the surface area of ​​the metal flakes.

5. Average particle diameter D ５０ The composite pigment according to claim 1, wherein the particle size is 5 μm or more.

6. The composite pigment according to claim 1 , having an average thickness of 0.05 μm or more and 250 μm or less.

7. The composite pigment of claim 1 , wherein the metal flakes are coated with a translucent material.

8. The metal flakes are (a) aluminum, copper, nickel, tin, titanium, and zinc; (b) an alloy containing at least one of (a), and (c) Stainless steel The composite pigment according to claim 1, wherein the pigment is at least one selected from the group consisting of:

9. A cosmetic comprising the composite pigment according to any one of claims 1 to 8.

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