Composite pigment

Abstract

Provided is a composite pigment that makes it possible to achieve new and distinctive coloring. The present invention includes glass flakes and a coloring pigment that is adhered to at least a portion of the surface of the glass flakes. The average of the ratio of the long diameter of the coloring pigment to the short diameter is 1.70–100.

Description

composite pigment

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

[0002] Color pigments have small primary particle diameters and are prone to re-aggregation, which makes their color development prone to change. For this reason, JP-A-5-214257 (Patent Document 1) stabilizes color development 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.

[0003] Japanese Patent Application Publication No. 5-214257

[0004] However, although the method described in Patent Document 1 stabilizes the color development of color pigments, it is not sufficient to meet the increasing 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.

[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 glass 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 glass flakes and a color pigment attached to at least a portion of the surface of the glass flakes, and the color pigment has an average ratio of the major axis to the minor axis of 1.70 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.

[0009] 1 is a diagram showing a schematic diagram of one of the color pigments on the glass flakes of the composite pigment. FIG. 2 is a diagram showing a scanning electron microscope photograph of the composite particles of Example 1. FIG. 3 is a diagram showing a scanning electron microscope photograph of the composite particles of Comparative Example 1.

[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] The composite pigment according to the present invention includes glass flakes and a color pigment attached to at least a portion of the surface of the glass flakes. The color pigment attached to the glass flakes has an average ratio of the major axis to the minor axis of 1.70 or more and 100 or less. The composition of the composite pigment will be described below.

[0012] <Glass Flakes> The glass flakes may be made of glass only, or the surfaces of the glass flakes may be coated with a light-transmitting material. Alternatively, the glass flakes may be made of a core material made of a material other than glass and the surface of the core material is coated with glass.

[0013] The aspect ratio of glass flakes is the ratio of the volume average particle diameter D to the average thickness t. ５０ The ratio (D ５０ / t). The aspect ratio of the glass 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 2 or more, a composite pigment containing glass flakes is likely to be uniformly oriented when applied, resulting in good color development. If the aspect ratio is 200 or less, when mechanical shear is applied during processing, the glass flakes are unlikely to break, resulting in good color development. On the other hand, if the aspect ratio is less than 2, uniform orientation may not be achieved when applied, resulting in poor color development. If the aspect ratio is greater than 200, when mechanical shear is applied during processing, the flakes may break, resulting in poor color development.

[0014] Average particle diameter D of the glass flakes used in the present invention ５０is preferably 5 μm or more and 300 μm or less, and more preferably 10 μm or more and 100 μm or less. If the average particle size is 5 μm or more, scattering at the corners of the glass flakes is reduced, resulting in good color development. If the average particle size is 300 μm or less, breakage of the glass flakes is unlikely to occur when mechanical shear is applied during processing, resulting in good color development. On the other hand, if the average particle size is less than 5 μm, the ratio of the corners to the surface of one glass flake becomes high, which may cause light scattering and result in poor color development. If the average particle size is more than 300 μm, breakage of the flakes may occur when mechanical shear is applied during processing, resulting in poor color development.

[0015] The thickness of the glass flakes used in the present invention is preferably 0.1 μm to 8 μm, more preferably 0.3 μm to 1 μm. If the thickness is 8 μm or less, uniform orientation is likely to occur when applied, resulting in good color development. If the thickness is 0.1 μm or more, the glass flakes are unlikely to break when subjected to mechanical shear during processing, resulting in good color development.

[0016] The glass flakes used in the present invention preferably have a high surface smoothness and high transparency. The material of the glass flakes is not particularly limited, and known glass flakes can be used. Generally, glass containing silicon dioxide as the main component, such as soda-lime glass, borosilicate glass, crystallized glass, quartz glass, lead glass, C-glass flakes, and E-glass flakes, can be used.

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

[0018] The surface of the glass flakes may be coated with a metal oxide, and the metal oxide is preferably at least one selected from the group consisting of silica, alumina, zirconia, iron oxide, zinc oxide, and titanium oxide.

[0019] As the glass flakes, commercially available glass flakes may be used, for example, the product name "FT1018FY" manufactured by Nippon Sheet Glass Co., Ltd.

[0020] <Colored Pigments> Examples of colored pigments 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. These colored pigments may be used alone or in combination of two or more. Commercially available particles of these colored pigments have a small ratio of the major axis to the minor axis (major axis / minor axis). However, by contacting the colored pigment with ammonia or a compound containing an amino group, needle-shaped crystals with a major axis / minor axis ratio of 1.70 or more can be formed.

[0021] When unevenness is formed on the surface of a glass flake by adhering a color pigment having an average major axis / minor axis ratio of 1.70 to 100, the glass flake can exhibit a characteristic color that has not been seen before. The average major axis / minor axis ratio of the color pigment is more preferably 1.70 to 15.0, and even more preferably 1.9 to 10.0. It is practically difficult to grow crystals of a color pigment until the average major axis / minor axis ratio exceeds 100.

[0022] Figure 1 shows a schematic diagram of one of the color pigments on glass flakes of the composite pigment of the present invention. 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 the major axis and minor axis and / or the major axis / minor axis ratio of 10 color pigment crystals randomly selected per field of view (provided that the entire color pigment is clearly recognizable), and then measuring the same for 10 different fields of view to calculate the arithmetic mean of the major axis / minor axis ratios for a total of 100 color pigment crystals. The major axis is the absolute maximum length of a single color pigment crystal in the field of view of the scanning electron microscope. The minor axis is the shortest distance between two lines parallel to the major axis when the color pigment is sandwiched between the two lines. The major axis and minor axis and / or the major axis / minor axis ratio can be calculated by printing out a scanning electron microscope photograph, placing a ruler over the crystal, and drawing a line, or by automatically calculating the ratio using a function provided in image software. As the imaging software, for example, WinROOF2003 manufactured by Mitani Shoji Co., Ltd. can be used. From the viewpoint of accuracy, it is preferable to use such imaging software.

[0023] The coverage of the glass flakes with the color pigment is preferably 10% or more, more preferably 20% or more, as a percentage (%) of the surface area of ​​the glass flakes covered with the color pigment relative to the surface area of ​​the glass flakes. In this specification, the coverage is determined by observing the surface of the composite pigment with a scanning electron microscope and expressing the percentage (%) of the area occupied by the color pigment in one field of view relative to the area of ​​one field of view randomly selected 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.

[0024] 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 glass flakes in addition to a color pigment having an average major axis / minor axis ratio of 1.70 or more and 100 or less.

[0025] <Protective Layer> The composite pigment of the present invention is preferably coated with a protective layer as needed. Forming a protective layer makes the adhesion of the color pigment stronger, and can further improve the resistance of the color pigment to detachment and elution by water or solvents.

[0026] The material of the protective layer is preferably a metal oxide such as silica, alumina, zirconia, titania, etc., and more preferably silica or alumina. A protective layer made of silica or alumina can be easily formed using a sol-gel method and can be formed at low cost.

[0027] The method for coating the 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, and 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. Among these, it is preferable to form the metal oxide coating by the sol-gel method. The sol-gel method allows for a uniform metal oxide coating.

[0028] The amount of the protective layer is not particularly limited, but is preferably 1 part by weight to 100 parts by weight, and more preferably 10 parts by weight to 40 parts by weight, relative to 100 parts by weight of the composite pigment before the protective layer is applied. If the amount of the protective layer is less than 1 part by weight, the protective layer may not be formed on the entire surface of the pigment, or the thickness of the protective layer may be extremely thin, resulting in an insufficient effect as a protective layer. On the other hand, if the amount of the protective layer is more than 100 parts by weight, the thickness of 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 glass flakes, the amount of color pigment applied, the coverage rate, etc.

[0029] <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 is preferably 5 μm or more and 300 μm or less, and more preferably 10 μm or more and 100 μm or less. ５０ If the average particle diameter D of the composite pigment is in the range of 5 μm or more and 300 μm or less, the color development is good. ５０ can be measured as the volume-average median diameter by dispersing a sample in an alcohol-based solvent and using a laser diffraction particle size distribution analyzer such as the MT3300EXII manufactured by Microtrac.

[0030] The average thickness t of the composite pigment according to the present invention is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.3 μm or more and 0.6 μm or less. When the average thickness of the composite pigment is 10 μm or less, it is likely to be uniformly oriented when applied, resulting in good color development. When the average thickness t is 0.1 μm or more, the saturation is high and the color development is good. The average thickness of the composite pigment 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 this is observed with a scanning electron microscope. The thicknesses of 10 or more randomly selected composite particles from the obtained image are measured, and the arithmetic mean is calculated. When the thickness varies depending on the position within a single composite pigment particle, the thickness is measured at three or more positions using the above method, and the average of the three thicknesses is calculated.

[0031] The average aspect ratio of the composite pigment (the volume average particle diameter D ５０ The ratio of D ５０ / t) 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 more than 200, the covering ability of the pigment will be poor, which may result in poor color development.

[0032] <Composite Pigment Manufacturing Process> Next, the process for manufacturing the composite pigment according to the present invention will be described. In the process for manufacturing the composite pigment, a wet method or a solid phase method can be used. The shape of the colored pigment may be controlled before or after it is attached to the surface of the glass flakes.

[0033] <Wet Method> In a production process using a wet method, a color pigment and a compound having an amino group are dispersed in a solvent to prepare a dispersion (slurry or paste) of the color pigment, and glass flakes are dispersed in the color dispersion to obtain the composite pigment of the present invention.

[0034] Any known compound having an amino group can be used without any particular limitation, and specific examples thereof include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, triethanolamine, and silane coupling agents having an amino group.

[0035] Suitable solvents include alcohols, ester-based 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 mixed in as needed to prevent elution of color pigments.

[0036] The method for dispersing the color pigment in the solvent is not particularly limited, but examples thereof include dispersion methods using a grinding medium such as a ball mill, a bead mill, or a sand mill. 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 temperature during dispersion is also not particularly limited, and may be in the range of 0°C to 100°C.

[0037] In addition to the above-mentioned dispersion methods, suitable dispersion methods for adding glass flakes to a dispersion of a color pigment and further dispersing the color pigment to adhere it to the surface of the glass flakes include stirring with a stirrer or disperser or kneading with a kneader mixer or the like. 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 temperature during dispersion is also not particularly limited, and may be in the range of 0°C to 100°C.

[0038] <Solid Phase Method> In a production process using the solid phase method, for example, glass flakes and a colored pigment are stirred and mixed using a dry particle composite device, and then a compound having an amino group is dispersed in water or a solvent to obtain the composite pigment of the present invention.

[0039] The dry particle compositing apparatus may be, for example, Nobilta (registered trademark) NOB (manufactured by Hosokawa Micron Corporation) or Hybridization System (manufactured by Nara Machinery Works, Ltd.) The peripheral speed of the stirring blades of the dry particle compositing apparatus should be in the range of 5 to 60 m / s, or the motor power per unit particle weight should be 0.1 to 100 W / g, which is preferable for uniformly adhering the color pigment to the surface of the glass flakes.

[0040] The compound having an amino group is not particularly limited and known compounds can be used, such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, triethanolamine, and silane coupling agents having an amino group.

[0041] 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.

[0042] The dispersion method is not particularly limited, but for example, dispersion methods using a grinding medium such as a ball mill, bead mill, or sand mill, stirring with a stirrer or disperser, or kneading with a kneader mixer are suitable. 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 temperature during dispersion is also not particularly limited, and may be within the range of 0°C to 100°C.

[0043] <Protective Layer> In the protective layer formation step, a preferred method is, for example, to add an alkoxysilane and water to a solution in which a composite pigment is dispersed, and adjust the pH value of the solution with a hydrolysis catalyst to hydrolyze and condense the alkoxysilane, thereby precipitating silica on the surface of the composite pigment.

[0044] The composite pigment prepared above is dispersed in a non-polar solvent, and a hydrophilic solvent containing alkoxysilane and water, and a base catalyst are gradually added to the solution to hydrolyze and condense the alkoxysilane. 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 carry out hydrolysis before adding the base catalyst.

[0045] Examples of alkoxysilanes include tetraethoxysilane, tetraethoxysilane condensates, tetraisopropoxysilane, tetraisopropoxysilane condensates, etc. The alkoxysilanes described above can be used alone or in combination of two or more.

[0046] Examples of the base catalyst include ammonia, triethylamine, n-butylamine, ethylenediamine, sodium hydroxide, and potassium hydroxide. The base catalyst may be used alone or in combination of two or more of the above. The amount of the base catalyst used is preferably 0.05 to 50 g / L in terms of the content in the solvent.

[0047] <Cosmetics> The composite pigment of the present invention can be blended into cosmetics. Cosmetics that can be blended with the composite pigment of the present invention are not particularly limited, but specific examples include lip gloss, nail polish, eye shadow, foundation, face powder, and makeup base. Depending on the intended use, a base can be appropriately selected from extender pigments, resins, waxes, oils, petrolatum, and the like, and blended with the composite pigment of the present invention to obtain a cosmetic.

[0048] The blending amount of the composite pigment of the present invention in cosmetics varies depending on the application, but for example, in lip gloss it is preferably from 0.05% to 5% by mass, and more preferably from 0.1% to 2% by mass, and in eye shadow it is preferably from 1% to 30% by mass, and more preferably from 2% to 10% by mass.

[0049] The cosmetic may contain other extender pigments, functional powders, moisturizers, surfactants, ultraviolet absorbers, fragrances, preservatives and other additives, as long as they do not impair the effects of the composite pigment of the present invention.

[0050] The present invention can be summarized as follows.

[0051] (1) A composite pigment comprising glass flakes and a color pigment attached to at least a portion of the surface of the glass flakes, wherein the color pigment has an average ratio of the major axis to the minor axis of 1.70 or more and 100 or less.

[0052] (2) The composite pigment according to (1) above, wherein the color pigment is an azo pigment.

[0053] (3) The composite pigment according to (1) or (2) above, wherein the coverage of the glass flakes with the coloring pigment is 10% or more, in terms of the ratio (%) of the surface area of ​​the glass flakes covered with the coloring pigment to the surface area of ​​the glass flakes.

[0054] (4) Average particle diameter D ５０ The composite pigment according to any one of (1) to (3) above, wherein the particle size is 5 μm or more and 300 μm or less.

[0055] (5) A composite pigment according to any one of (1) to (4) above, having an average thickness t of 0.1 μm or more and 10 μm or less.

[0056] (6) Average particle diameter D relative to average thickness t ５０ The aspect ratio (D ５０ / t) is 2 or more and 200 or less.

[0057] (7) A cosmetic comprising the composite pigment described in any one of (1) to (6) above.

[0058] The composite pigment according to the present invention will be described in more detail below by showing specific production examples and test results.

[0059] Example 1 2 g of commercially available Red No. 202 (SUNCROMA (registered trademark) D&C RED7 CALAKE manufactured by DIC Corporation) as a color pigment and glass flakes (Nippon Sheet Glass Co., Ltd., average particle diameter (D ５０20 g of the powder (18 μm) was mixed with a glass rod. Then, using a dry particle compositer, the powder was stirred and mixed for 10 minutes at a motor power load of 2 W / g per unit weight to obtain a composite.

[0060] 20 g of the obtained composite was placed in a 0.5 L reaction vessel (Shibata Scientific Co., Ltd., cylindrical band-type separable flask), 300 g of ion-exchanged water mixed with 20 g of isopropyl alcohol was added, and 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane was added, followed by stirring for about 5 minutes to obtain a slurry. The obtained slurry was subjected to solid-liquid separation using a filter, and 20 g of the solid was placed in a 0.5 L reaction vessel, 120 g of isoparaffin was added, and the temperature in the system was raised to 40 ° C. Next, 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane was added, and a mixed solution obtained by diluting 11 g of tetraethoxysilane (TEOS) with 11 g of isopropyl alcohol was introduced over a period of about 20 minutes. At the same time, a mixed solution obtained by diluting 7 g of ion-exchanged water and 1 g of 25% ammonia water with 60 g of isopropyl alcohol (hereinafter referred to as "mixed solution A") was introduced over a period of about 70 minutes. The temperature within the system was then raised to 75°C. Next, 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane was added, and then a mixed liquid prepared by diluting 7 g of tetraethoxysilane (TEOS) with 7 g of isopropyl alcohol was added over approximately 20 minutes, followed by stirring for 120 minutes. The mixture was then subjected to solid-liquid separation using a filter and powdered in a dryer to obtain the composite pigment of Example 1.

[0061] The obtained composite pigment was photographed at 10,000x magnification using a scanning electron microscope JSM-5510 (manufactured by JEOL Ltd.) (Figure 2). Using imaging software (WinROOF2023, manufactured by Mitani Shoji Co., Ltd.), 10 particles of the colored pigment attached to the surface of the glass flake were randomly selected per field of view, for a total of 100 particles across 10 fields of view, and the major axis / minor axis ratio of each was measured and the average value was calculated. In Figure 2, the 10 solid white objects at the ends of the arrows represent the 10 randomly selected colored pigment particles. The average major axis / minor axis ratio was 4.5.

[0062] Furthermore, the coverage of the glass flakes, which is the ratio (%) of the surface area of ​​the glass flakes covered with the color pigment to the surface area of ​​the glass flakes within one field of view (FIG. 2) of the scanning electron microscope photograph, was 90%.

[0063] In addition, the average particle diameter D of the composite particles １０ is 7.5 μm, and the average particle diameter of the composite particles D ５０ is 18 μm, and the average particle diameter of the composite particles D ９０ The average thickness is 1.8 μm, and the aspect ratio (D ５０ The ratio of the major axis to the minor axis of the color pigment of the obtained composite pigment, the coverage (%) of the glass flake surface with the color pigment, and the average particle diameter D of the composite pigment were also measured. ５０ , average particle diameter D of the composite pigment ９０ The average particle diameter D of the composite pigment was measured in the same manner in the following Examples and Comparative Examples. ５０ The particle size distribution can be measured by dispersing a sample in an alcohol-based solvent and using a laser diffraction particle size distribution analyzer such as the MT3300EXII manufactured by Microtrac.

[0064] The average thickness of the composite particles was determined by cutting the flat particles in a forcibly oriented state using ion milling or the like, and measuring the distance from one end of the particle to the other end in the thickness direction in an image of the cross-section taken with an optical microscope, laser microscope, SEM, or the like. Specifically, the thickness was determined using the following procedure: (Step 1) The flat particles were forcibly oriented in a resin or the like and completely solidified. (Step 2) The sample piece prepared in (Step 1) was cut perpendicular to the orientation direction using ion milling or the like to prepare a sample for cross-sectional observation. (Step 3) The sample for cross-sectional observation was photographed with an optical microscope, laser microscope, or SEM. (Step 4) The distance from one end of the particle to the other end in the thickness direction was measured using the "distance between two points" function of the analysis function for the obtained cross-sectional image. The analysis function can be performed using the analysis function provided with the microscope, or image analysis software (e.g., WinROOF2023). In addition to using the "distance between two points" function of the analysis function, displaying a gauge when photographing the cross-sectional image allows for easy measurement of the same distance using a ruler on the screen. (Step 5) At least 10 particles were randomly selected from the cross-sectional image, and the operation of (Step 4) was performed on each particle. The average value was taken as the particle thickness (μm).

[0065] The particle size corresponding to 10% of the cumulative volume from the smallest particle side is called D １０ The particle size corresponding to 50% of the cumulative volume from the smallest particle side is D ５０ The particle size corresponding to 90% of the cumulative volume from the smallest particle side is D ９０ If it is defined as (D ９０ -D １０ ) / D ５０ The value is preferably 3 or less, and more preferably 1.5 or less.

[0066] Example 2 A composite pigment of Example 2 was obtained in the same manner as in Example 1, except that the mixed solution A of Example 1 was introduced over a period of about 40 minutes.

[0067] The composite pigment of Example 2 had an average major axis / minor axis ratio of 10.0, a coverage of the glass flake surface with the color pigment of 90%, and an average particle diameter D １０ is 7.5 μm, average particle diameter D ５０is 18 μm, and the average particle diameter of the composite pigment D ９０ is 31 μm, the average thickness t of the composite pigment is 1.8 μm, and the aspect ratio (D ５０ / t) was 10.

[0068] Example 3 To a pot mill having a diameter of 8 cm and an internal volume of 500 cc into which 200 g of zirconia beads having a diameter of 1 mm had been inserted, 70 g of commercially available Red No. 202 (manufactured by DIC Corporation: SUNCROMA (registered trademark) D&C RED7CALAKE) as a color pigment, 0.59 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane, and 180 g of isopropyl alcohol were added, and the color pigment was dispersed in the ball mill for 4 hours to prepare a colored slurry.

[0069] Then, 7 g of the colored slurry and 20 g of glass flakes (manufactured by Nippon Sheet Glass Co., Ltd., average particle size 18 μm) were mixed in a PP cup and dispersed with a glass rod. This process yielded a pigment in which Red No. 202 was adhered to the surface of the glass flakes.

[0070] 20 g of the resulting pigment was placed in a 0.5 L reaction vessel, 120 g of isoparaffin was added, and the temperature in the system was raised to 40°C. Next, 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane was added, and a mixed solution prepared by diluting 11 g of tetraethoxysilane (TEOS) with 11 g of isopropyl alcohol was introduced over approximately 20 minutes. At the same time, mixed solution A used in Example 1 was introduced over approximately 70 minutes. Thereafter, the temperature in the system was raised to 75°C. Next, 0.1 g of N-2-aminoethyl-3-aminopropylmethyldimethoxysilane was added, and a mixed solution prepared by diluting 7 g of tetraethoxysilane (TEOS) with 7 g of isopropyl alcohol was introduced over approximately 20 minutes. The mixture was then stirred for 120 minutes.

[0071] The mixture was then separated into solid and liquid using a filter and powdered using a dryer to obtain the composite pigment of Example 3.

[0072] The composite pigment of Example 3 had an average major axis / minor axis ratio of 1.9, a coverage of the glass flake surface with the color pigment of 90%, and an average particle diameter D １０ is 7.5 μm, average particle diameter D ５０is 18 μm, and the average particle diameter of the composite pigment D ９０ is 31 μm, the average thickness t of the composite pigment is 1.8 μm, and the aspect ratio (D ５０ / t) was 10.

[0073] Example 4 A composite pigment of Example 4 was obtained in the same manner as in Example 1, except that the mixed solution A of Example 1 was introduced over a period of about 5 minutes. The composite pigment of Example 4 had a major axis / minor axis ratio of 89, a coverage rate of the glass flake surface by the color pigment of 89%, and an average particle diameter D of the composite pigment of Example 4. １０ is 7.7 μm, average particle diameter D ５０ is 19 μm, the average particle diameter of the composite pigment D ９０ is 32 μm, the average thickness t of the composite pigment is 1.9 μm, and the aspect ratio (D ５０ / t) was 10.

[0074] Comparative Example 1 40 g of commercially available Red No. 202 (SUNCROMA (registered trademark) D&C RED 7 CALAKE, manufactured by DIC Corporation) as a color pigment and 400 g of glass flakes (manufactured by Nippon Sheet Glass Co., Ltd., average particle size 18 μm) were mixed with a glass rod. Next, using a dry particle compositer, the mixture was stirred and mixed for 3 minutes at a motor power per unit weight of 12.5 W / g, to obtain a composite pigment of Comparative Example 1.

[0075] 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 Figure 3. In Figure 3, the solid white areas at the ends of the 10 arrows represent 10 randomly selected colored pigments.

[0076] The composite pigment of Comparative Example 1 had an average major axis / minor axis ratio of 1.2, a coverage of the glass flake surface with the color pigment of 95%, and an average particle diameter D １０ is 8 μm, and the average particle diameter of the composite pigment D ５０ is 18 μm, and the average particle diameter of the composite pigment D ９０ is 31 μm, the average thickness t of the composite pigment is 1.8 μm, and the aspect ratio (D ５０ / t) was 10.

[0077] Comparative Example 2 2 g of commercially available Red No. 202 (SUNCROMA (registered trademark) D&C RED7C ALAKE, manufactured by DIC Corporation) as a color pigment and 20 g of glass flakes (average particle size 18 μm, manufactured by Nippon Sheet Glass Co., Ltd.) 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 per unit weight of 2 W / g, to obtain the glass flake pigment of Comparative Example 2.

[0078] The color pigment of the composite pigment of Comparative Example 2 was crushed into a smooth layer, and the ratio of major axis to minor axis could not be measured. The coverage of the glass flake surface with the color pigment was 100%, and the average particle diameter D of the composite pigment was 100%. １０ is 7.7 μm, and the average particle diameter of the composite pigment D ５０ is 18 μm, and the average particle diameter of the composite pigment D ９０ is 31 μm, the average thickness t of the composite pigment is 1.8 μm, and the aspect ratio (D ５０ / t) was 10.

[0079] <Colorimetry> 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. The values ​​in the table are colorimetric values ​​measured at a viewing angle of 25°.

[0080]

[0081] As shown in Table 1, the composite pigments of Examples 1 to 4 did not have a significant difference in L* value and a* value compared to the composite pigments of Comparative Examples 1 and 2, but the b* value was 8 points or more lower, resulting in a hue that could not be obtained by conventional methods.

[0082] <Preparation of Lip Gloss> The ingredients in Section A in Table 2 were weighed into a disposable cup and mixed while melting in a hot water bath at 80 to 90°C. The composite pigment in Section B was then added and mixed, and the mixture was poured into a transparent container to prepare a lip gloss. The blending amounts of each ingredient in Table 2 are in mass %.

[0083]

[0084] The lip gloss of formula 1 had a vivid pink appearance. The lip gloss of formula 2 had excellent transparency and brightness, but some red pigment was observed to have fallen off and aggregated. When applied to the lips, formula 1 imparted a glossy feel and a healthy glow. Formula 2 imparted a glossy feel but no healthy glow.

[0085] <Preparation of Eye Shadow> The extender pigment and spherical powder of Category A shown in Table 3 were placed in a disposable cup and mixed with a spatula. The mixture was then placed in a mixer and mixed for 1 minute. The color pigment or the composite pigment of Example 1 or Comparative Example 1 was then added and mixed in the mixer for an additional 30 seconds. Subsequently, the raw materials of Category B were added to the mixer and mixed for an additional 1 minute. The resulting powder was removed, and an appropriate amount was placed in a mold and pressed to obtain an eye shadow. The amounts of each raw material in Table 3 are in mass %.

[0086]

[0087] The obtained eye shadow powder before pressing was measured using a spectrophotometer CM-5 (manufactured by Konica Minolta) to evaluate the chroma c*. The powder to be measured was filled into a small petri dish (φ3 mm) and subjected to measurement. The light source used was D65, and color measurement was performed using the SCE (specular reflection excluded) method at a viewing angle of 2°. The results are shown in Table 4.

[0088]

[0089] A bright pink color was observed from the eye shadow of Formula 3 containing the composite pigment of Example 1. Furthermore, when applied to the back of the hand and observed, a clear red color without dullness was visually recognized. Formula 4 containing the composite pigment of Comparative Example 1 had lower saturation than Formula 3. Formula 5 not containing the composite pigment had an even lower saturation and a slightly rough texture.

[0090] 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 the above description, and includes all modifications within the meaning and scope of the claims.

Claims

Glass flakes and a color pigment adhered to at least a portion of the surface of the glass flakes; The color pigment is a composite pigment having an average ratio of the major axis to the minor axis of 1.70 or more and 100 or less. 　 The composite pigment according to claim 1 , wherein the color pigment is an azo pigment.

2. The composite pigment according to claim 1, wherein a coverage rate of the glass flakes with the color pigment is 10% or more, where the percentage (%) of the surface of the glass flakes covered with the color pigment is 10% or more relative to the surface area of ​​the glass flakes. Average particle diameter D ５０ The composite pigment according to claim 1, wherein the particle size is 5 μm or more and 300 μm or less. 　 The composite pigment according to claim 1 , wherein the average thickness t is 0.1 μm or more and 10 μm or less. Average particle diameter D relative to average thickness t ５０ The aspect ratio (D ５０ 2. The composite pigment according to claim 1, wherein the value of (t) is 2 or more and 200 or less. 　 A cosmetic comprising the composite pigment according to any one of claims 1 to 6.

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