Black coloring composition and black pigment dispersion

Abstract

This invention provides an extremely high-quality black coloring composition that achieves both high blackness and a beautiful gloss. [Solution] Organic solvent, dispersant, thermosetting resin, specific surface area of ​​250 m² 2 The black coloring composition contains fine carbon black particles in a specified amount per gram and hollow silica with a median diameter D50 of 300 nm or less.

Description

[Technical Field]

[0001] The present invention relates to a black coloring composition having extremely high jet-black properties, and a black pigment dispersion that can be suitably used in the preparation of the same. [Background technology]

[0002] To enhance aesthetic appeal, it is common practice to color automobiles, home appliances, and building interior materials black. The most common methods of coloring involve printing or applying a black coloring composition to the object to be colored using various printing methods such as spraying, screen printing, and inkjet printing, or coating methods using brushes or spin coating, thereby forming a black coating on the object's surface.

[0003] As a black coloring composition, there is a demand for a jet-black color to enhance the aesthetic appeal of the object being colored. Here, jet black means that the object is extremely black to the human eye and also has a lustrous sheen like lacquer.

[0004] Existing black coloring compositions that exhibit jet-black properties widely use carbon black as a colorant, which is excellent in terms of price, safety, and availability, and are dispersed in solvents such as water or organic solvents.

[0005] Existing black coloring compositions using carbon black have a certain degree of jet blackness, but in recent years, there has been a demand for even higher levels of jet blackness to further improve design and aesthetics. Specifically, what is needed is a black coloring composition that has an extremely high degree of blackness, which allows it to be perceived as a perfect black even when the coated surface is observed for several minutes, without appearing as a whitish black or dark gray, and that also possesses a lustrous sheen that evokes a sense of beauty.

[0006] To meet these demands, methods have been investigated to enhance the deep blackness of carbon black-based black coloring compositions. The main existing methods include the following:

[0007] One method involves using carbon black with small primary particles (referring to the individual domains of the carbon black that make up the aggregate) to obtain a colored composition with high jet-black properties.

[0008] However, the inventors' research has revealed that this method results in a coating that is a somewhat whitish, blurry black, failing to achieve the high level of blackness demanded by the market. Furthermore, it also has problems such as reduced dispersion stability and worsened storage stability.

[0009] Furthermore, a technique has been proposed in which dry silica or resin particles are mixed into a colored composition containing carbon black (e.g., Patent Document 1).

[0010] However, this method is intended for anti-reflective purposes, and silica is used as a matting agent. Therefore, the inventors' research has revealed that this method does not produce sufficient gloss and cannot achieve the beautiful luster demanded by the market.

[0011] Furthermore, as a method for coloring to a highly jet black, there is a method that uses a laminate combining a black coating layer made of a black pigment such as carbon black and a low refractive index coating layer made of silicon compounds, etc. (Patent Document 2, etc.). However, this method is complicated, lacks convenience and workability, and is expensive. Moreover, it was not possible to obtain a coating that combined high blackness and gloss using this method alone. As described above, conventional black compositions using carbon black as a coloring agent have not been able to achieve both high blackness and a glossy finish, and therefore lacked the deep blackness required by the market. The present inventors have proposed a solution to this problem using a black pigment dispersion and a black coloring composition containing carbon black and silica having specific physical properties (Patent Document 3). This method can provide a black coloring composition that combines significantly higher levels of deep blackness and gloss compared to previous technologies. However, the market demands even higher levels of deep blackness and gloss. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2020-97730 [Patent Document 2] Japanese Patent Publication No. 2019-181852 [Patent Document 3] WO / 2024 / 029631 [Overview of the project] [Problems that the invention aims to solve]

[0013] The objective of the present invention is to resolve the problems of the above-mentioned existing technologies. Specifically, the objective is to provide a new black coloring composition that uses carbon black as a colorant, has a high degree of blackness that makes it appear blacker to the human eye, while also possessing a beautiful gloss that gives an aesthetic impression, and can be manufactured and applied in the same way as conventional coloring compositions without undergoing any special processes, thereby providing a new black coloring composition with high jet-blackness. [Means for solving the problem]

[0014] Therefore, the present inventors conducted diligent studies to achieve the above objective and discovered that a new black coloring composition can be obtained that exhibits extremely high jet blackness when formed into a coating film, by using an organic solvent, a dispersant, and a thermosetting resin, using fine-particle carbon black with a specific surface area of ​​a predetermined or greater as a colorant, and adding fine-particle silica having predetermined characteristics. This led to the present invention. Furthermore, the inventors have invented a black coloring dispersion liquid that can be suitably used to prepare the above black coloring composition, containing an organic solvent, a dispersant, fine-particle carbon black with a specific surface area of ​​a predetermined or greater, and fine-particle silica having predetermined characteristics.

[0015] In other words, the present invention discloses: (1) Specific surface area is 250 m 2 A black pigment dispersion characterized by containing at least carbon black (1g or more), hollow silica with a median diameter D50 of 300nm or less, an organic solvent, and a dispersant. (2) A black coloring composition characterized by comprising the black pigment dispersion described in (1) above and a thermosetting resin. (3) Specific surface area of ​​250 m 2 A black coloring composition characterized by comprising carbon black of 1 / g or more, hollow silica with a median diameter D50 of 300 nm or less, an organic solvent, a dispersant, and a thermosetting resin. (4) The black coloring composition described in (3) above, characterized in that the weight concentration of carbon black [weight of carbon black / (weight of dispersant solids + weight of thermosetting resin solids + weight of carbon black + weight of hollow silica)] is 5 to 15%. (5) The black coloring composition according to (3) above, characterized in that when the coating film is 3.0 μm thick, the brightness is such that the brightness SCE L* is 2.0 or less and the SCI L* is 22.5 or less when measured from the coating film surface, and the gloss at 60° of the coating film is 70 GU or more when measured from the coating film surface. (6) The black coloring composition according to (3) above, characterized in that the weight ratio (A) / (B) of carbon black (A) to hollow silica (B) is in the range of 0.33 or more and 4.10 or less. (7) A method for producing a black colored composition, characterized by adding a thermosetting resin to the black pigment dispersion described in (1) above. (8) A coloring method characterized by printing and applying the black coloring composition described in (3) above to a substrate. (9) Carbon black with a specific surface area of 250 m 2 / g or more, hollow silica with a median diameter D50 of 300 nm or less, a dispersant, and a thermosetting resin, and a coating film characterized by containing at least these components. (10) When measured from the coating film surface side, the lightness SCE L* is 2.0 or less and the SCI L* is 22.5 or less, and the 60° gloss of the coating film is 70 GU or more when measured from the coating film surface. The coating film described in (9) above is characterized by these properties. (11) A method for manufacturing a coating film, characterized by including a step of applying and curing the black coloring composition described in (3) above to a substrate. (12) At least carbon black (A) and hollow silica (B) with a median diameter D50 of 300 nm or less are contained in a ratio such that the weight ratio (A) / (B) is 0.33 or more and 4.10 or less, and the carbon black concentration is 2 to 30% by weight. Both carbon black (A) and hollow silica (B) are dispersed in an organic solvent with a dispersed particle size D50 of 150 nm or less. A black pigment dispersion liquid is characterized by these properties. (13) A method for manufacturing a black pigment dispersion liquid, characterized by mixing at least carbon black (A) and hollow silica (B) with a median diameter D50 of 300 nm or less in an organic solvent in a ratio such that the weight ratio (A) / (B) is 0.33 or more and 4.10 or less, and the carbon black concentration is 2 to 30% by weight, and dispersing until D50 becomes 150 nm. (14) A method for manufacturing a black coloring composition, characterized by mixing at least carbon black (A) and hollow silica (B) with a median diameter D50 of 300 nm or less in an organic solvent in a ratio such that the weight ratio (A) / (B) is 0.33 or more and 4.10 or less, and the carbon black concentration is 2 to 30% by weight, dispersing until D50 becomes 150 nm, and further adding a thermosetting resin in an amount such that the solid content concentration is 10 to 50% by weight of the entire composition. And (15) A method for producing a black coloring composition, characterized in that a hollow silica having a weight ratio (A) / (B) of carbon black (A) to hollow silica (B) with a median diameter D50 of 300 nm or less and a thermosetting resin having a solid content concentration of 10 to 50% by weight of the whole composition are added to a black pigment dispersion liquid in which 2 to 30% by weight of carbon black (A) is dispersed in an organic solvent. It is.

Effect of the Invention

[0016] By using the black coloring composition of the present invention, a coating film exhibiting extremely high jet blackness can be formed on the surface of a coloring object as a black coloring composition using carbon black as a coloring material, which can contribute to improving the design and aesthetics of the object. Further, by using the black pigment dispersion liquid of the present invention, the black pigment dispersion liquid can be produced.

Brief Description of the Drawings

[0017] [Figure 1] It is a figure which shows the SEM photograph (100,000 times) of the hollow silica dispersion liquid obtained in Example 2. [Figure 2] It is a figure which shows the SEM photograph (100,000 times) of the hollow silica dispersion liquid obtained in Example 2. [Figure 3] It is a figure which shows the SEM photograph (100,000 times) of the hollow silica dispersion liquid obtained in Example 2. [Figure 4] It is a figure which shows the SEM photograph (100,000 times) of the hollow silica dispersion liquid obtained in Example 11. [Figure 5] It is a figure which shows the SEM photograph (100,000 times) of the hollow silica dispersion liquid obtained in Example 11. [Figure 6] It is a figure which shows the SEM photograph (100,000 times) of the hollow silica dispersion liquid obtained in Example 11. [Figure 7] It is a figure which shows the SEM photograph (100,000 times) of the hollow silica dispersion liquid obtained in Example 12.​​This figure shows an SEM image (100,000x magnification) of the hollow silica dispersion obtained in Example 12. [Figure 9] This figure shows an SEM image (100,000x magnification) of the hollow silica dispersion obtained in Example 12. [Figure 10] This figure shows a graph of the relationship between the rate of cracking of hollow silica in a hollow silica dispersion and SCI L*. [Modes for carrying out the invention]

[0018] <Definition of the word> In this invention, "coloring composition" means a composition that can be used to color any object, and "black coloring composition" means a coloring composition that can color an object black. So-called paint compositions or their precursors also fall under this category. In this invention, "pigment dispersion" refers to a composition in which a pigment is dispersed in a liquid medium. In this invention, "coating film" refers to a film layer formed on the coated surface of a substrate (regardless of material or shape, this refers to an object to which the coloring composition is applied) by applying or printing the coloring composition onto the substrate.

[0019] The black pigment dispersion of the present invention contains at least carbon black, hollow silica, an organic solvent, and a dispersant. The black coloring composition of the present invention contains at least carbon black, hollow silica, an organic solvent, a dispersant, and a thermosetting resin. Each of these components will be described below. <Departure materials> (Carbon Black) In this invention, carbon black is used as the coloring agent. The type of carbon black used in this invention is not particularly limited, and Ketjenblack, furnace black, acetylene black, thermal black, etc., can be used. Furthermore, one type of carbon black can be used alone, or two or more types can be used in combination.

[0020] The carbon black used in this invention has a specific surface area of ​​250 m². 2Characterized in that it is 300 m 2 / g or more, preferably the specific surface area is 350 m 2 / g or more, more preferably the specific surface area is 400 m 2 / g or more, even more preferably 500 m 2 / g or more is most preferred. Carbon black with a specific surface area of 250 m 2 / g or more absorbs more light when formed into a coating film and exhibits excellent blackness. The specific surface area of the carbon black in the present invention refers to the measured value by the nitrogen gas adsorption method according to ASTM D6556.

[0021] The DBP oil absorption amount of the carbon black used in the present invention is not particularly limited, but it is preferably 170 cc / 100 g or less, particularly preferably 120 cc / 100 g or less. When the DBP oil supply amount is within the above range, the wettability of the pigment with respect to the solvent is good, so the dispersion state can be relatively easily stabilized, contributing to the improvement of blackness and storage stability. The DBP oil absorption amount in the present invention refers to the value measured according to ASTM D2414.

[0022] It is preferable to use acidic carbon black having polar groups such as hydroxyl groups and carboxyl groups on the surface for the carbon black used in the present invention. Acidic carbon black having polar groups has good compatibility with vehicles such as solvents and dispersants, and is excellent in dispersibility and dispersion stability in the coloring composition. In particular, when using carbon black with a large specific surface area, the dispersant may not reach the entire carbon black particles and it may be difficult to exert the dispersion effect. Therefore, it is preferable to use acidic carbon black having many polar groups to improve the compatibility.

[0023] Carbon blacks that can be used in this invention include Raven 5000U3, Raven 5000UII, Raven 2800U, Raven 3000U, Raven 3500, Raven 2900U, Raven 2500U (all manufactured by Birla Carbon), #980, #960, #950, #900, #2300, #2350, #2600, #2650 (all manufactured by Mitsubishi Chemical Corporation), Colour Black FW-200, Colour Black FW-2, Colour Black FW-255, Colour Black FW-171, Colour Black FW-1, Colour Black FW-18, Colour Black FW-182, Colour Black FW-285, Colour Black FW-310, Special Black 6, Special Black 5, Printex 95, Printex Examples include the 90 (or higher, manufactured by Orion), but this list is not limited to these.

[0024] In the black coloring composition of the present invention, the concentration of carbon black is preferably 0.2 to 20% by weight. Particularly preferably 1 to 10% by weight, and most preferably 1.5 to 5% by weight. If the carbon black concentration in the black coloring composition is higher than this, the viscosity of the black coloring composition may increase, potentially reducing its film-forming ability. If the carbon black concentration in the black coloring composition is lower than this, it may become difficult to mold the coating film, or the color intensity of the molded coating film may be low. The weight ratio of carbon black in the solid content of the black coloring composition of the present invention is preferably 2 to 25% by mass, and particularly preferably 5 to 15% by mass, calculated as [weight of carbon black / (weight of dispersant solids + weight of resin solids + weight of carbon black + weight of silica)]. If this weight ratio of carbon black is less than 2% by mass, the light-shielding properties and jet blackness may decrease. On the other hand, if the weight ratio of carbon black is more than 25% by mass, re-aggregation and separation may occur, resulting in poor storage stability. In this invention, solid weight refers to the weight obtained by subtracting the weight of the solvent or dispersion medium contained in the dispersant and resin from their total weight, when the dispersant or resin is in solution or dispersion form. Therefore, the solid weight can be obtained by heating the dispersant and resin to completely evaporate the solvent or dispersion medium and calculating the difference between the weight before and after heating.

[0025] (Hollow silica) This invention incorporates hollow silica. In this invention, "hollow silica" refers to silica that has pores inside the particles. When silica particles are observed with a transmission electron microscope, two layers with different contrasts (an outer shell and a hollow part) can be observed, confirming that they are hollow. The proportion of the hollow part to the entire particle may be expressed as the hollowness ratio or porosity, and can be determined by measuring the length of each of the two layers toward the particle center using a transmission electron microscope and calculating the volume from that value. The hollowness ratio is not limited, but is usually around 20 to 95 vol%, preferably 25 to 90 vol%, and more preferably around 30 to 50 vol%. If it is too small, the effects of this invention may not be easily realized, and if it is too large, the particles may be prone to breaking.

[0026] The particle size of the hollow silica has a median diameter D50 of 300 nm or less. Within this range, it is particularly effective in suppressing the number of coarse particles and preventing defects such as blemishes and whitening, and the resulting gloss is especially lustrous. Preferably, the D50 is 250 nm or less, and most preferably, it is 150 nm or less. The median diameter D50 refers to the particle size at which the volume accumulation reaches 50% when the volume accumulation of the volume accumulation particle size distribution curve, measured by dynamic light scattering, is plotted from the smallest diameter side. In this invention, the following measurement method is used, but other methods may be used if similar results can be obtained. Measurement device: Dynamic light scattering particle size distribution analyzer (Microtrac Wave II, manufactured by Microtrac Bell Co., Ltd.) Settings: Particle refractive index 1.45, Solvent refractive index 1.38 Conditioning: Silica was added to the solvent (methyl ethyl ketone) to a concentration of 5% by weight, and the mixture was stirred for 15 minutes using a paint shaker (manufactured by Asada Iron Works Co., Ltd.) before measurement.

[0027] The method for producing hollow silica is not particularly limited, and any silica obtained by various known methods can be used. In addition, commercially available hollow silica products such as "JP-HS-070H" and "JP-JS-070HM" (both product names) manufactured by Sinosera can be suitably used. You may use one type of hollow silica alone, or you may use two or more different types in combination.

[0028] In this invention, hollow silica that has been surface-modified by conventionally known methods, such as hydrophobic treatment, can be used, but sufficient effects can be achieved even without surface modification.

[0029] In this invention, the mechanism by which the blackness as seen by the eye is dramatically improved by including hollow silica in a black coloring composition containing carbon black is not fully clear, but the inventors speculate that this is because the resulting coating film can absorb more light and has fewer irregularities compared to those produced by conventional techniques. The reason why it absorbs so much light is speculated to be as follows: Since hollow silica has a lower specific gravity than black pigment, when a black coloring composition is applied to the surface of a substrate and dries, the hollow silica concentrates near the surface of the coating film. Therefore, it is thought that the resulting coating film will have a high concentration of silica on the surface, while carbon black is distributed throughout the entire film. This effect is particularly pronounced in silica whose surface is modified with hydrophobic groups, because the hydrophobic groups have a higher affinity for air than the inside of the coating film → check the examples. When light is shone on a coating film in this state, reflection is kept extremely low because a low refractive index hollow silica layer is formed near the surface of the coating film. Light that passes through this area is taken into the coating film, and much of it cannot escape the coating film. Instead, it repeatedly refracts among the carbon black dispersed within the coating film, colliding with and being absorbed by the carbon black. For this reason, the coating film obtained with the black coloring composition of the present invention is thought to exhibit a higher degree of blackness compared to conventional coating films that do not use hollow silica, because more light collides with and is absorbed by the carbon black.

[0030] Furthermore, because both the carbon black and hollow silica present on the surface are fine particles and the surface of the coating is relatively smooth, reflected light is less likely to become scattered light, resulting in less whitening and bumps. For this reason, it is presumed that this method exhibits a more lustrous finish compared to conventional techniques such as those described in Patent Document 1, which use silica of 1 μm or larger to create surface irregularities and thereby achieve blackness.

[0031] The weight ratio (A) / (B) of carbon black (A) to hollow silica (B) in the black coloring composition of the present invention is preferably 0.33 to 4.10, and particularly preferably 0.33 to 1.00. If it is less than 0.33, scattered light will be increased, impairing gloss and potentially reducing blackness. If it is greater than 4.00, the aforementioned effects may not be fully exhibited. When hollow silica provided in the form of a dispersion is used, the weight of hollow silica in the dispersion (solid content weight), not the total weight of the dispersion, should be used as (B) above. The same numerical range is also preferred for (A) / (B) in the black coloring composition of the present invention. If the black coloring composition of the present invention is prepared by preparing the black pigment dispersion of the present invention as described later, and then adding a thermosetting resin, the (A) / (B) ratio will be maintained.

[0032] (Dispersant) The dispersant used in the present invention is not particularly limited, but dispersants with a polyether-based or polyester-based polymer structure, or pigment derivatives having a phthalocyanine skeleton structure are preferred because they exhibit good dispersibility with fine carbon black particles. Examples of commercially available polyether-based or polyester-based dispersants include the Solsperse series (9000, 13240, 13940, 17000, 20000, 24000, 26000, 28000, 32000, 32550, 33000, 33500, 34750, 35000, 37500, 38500, 39000, 56000, 71000, 75000, 75500, 76500) (Lubrisol), the Ajisper series (PB-821, PB-822, PB-824) (Ajinomoto Fine Techno), the Hinoact series (T-6000, T-8000) (Kawaken Fine Chemical), and TEGO. The DISPERS series (650, 651, 655, 670, 685) (Evonik), the Disparon series (#7004, DA-234, DA-320, DA-325, DA-330, DA-375, DA-703-50, DA-7301, KS-860) (Kusumoto Chemical Co.), the JEFFAMINE series (M-600, M-1000, M2005, M-2070, D-230, D-430, D-2000, D-4000, ED-600, ED-900, ED-2003) (Huntsman Co.), etc., can be suitably used. Furthermore, commercially available pigment derivatives having a phthalocyanine skeleton structure, such as the Solsperse series (5000, 12000) (Lubrizol), can be suitably used.

[0033] The total amount of dispersant used in the present invention is preferably 20 to 300 parts by weight, and more preferably 40 to 150 parts by weight, when the total amount of carbon black and hollow silica is 100 parts by weight. If the amount of dispersant is less than 20 parts by weight, the dispersant may not be able to exert its full potential, and the carbon black may not be sufficiently dispersed. If the amount of dispersant is greater than 300 parts by weight, the concentration of carbon black will be diluted, making it difficult to maintain the opacity of the coating film, and there is a risk that the film-forming properties during coating will deteriorate. As described later, it is preferable to use carbon black and hollow silica as pre-dispersed liquids using a dispersant as described above. In this case, the amount of dispersant is 20 to 300 parts by weight, preferably 40 to 150 parts by weight, per 100 parts by weight of carbon black. The amount of dispersant is 20 to 300 parts by weight, preferably 40 to 150 parts by weight, per 100 parts by weight of hollow silica. Within this range, in particular, a good dispersion state can be obtained at a sufficient concentration, resulting in a coating film with excellent jet blackness and gloss.

[0034] (Organic solvents) The organic solvent used in the present invention is not particularly limited, and known solvents can be appropriately selected. For example, methanol, ethanol, ethyl cellosolve, ethyl cellosolve acetate, diglyme, cyclohexanone, ethylbenzene, xylene, isoamyl acetate, n-amyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether Butyl ether, diethylene glycol monobutyl ether acetate, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether, triethylene glycol monoethyl ether acetate, liquid polyethylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoethyl ether acetate, lactic acid ester, ethyl ethoxypropionate, etc. can be suitably used. In addition to these organic solvents, water can also be used in combination as long as it does not hinder the effects of the present invention. Specifically, it is preferable that the amount of water be 5 parts by weight or less per 100 parts by weight of the organic solvent, more preferably 1 part by weight or less, and most preferably no water is included. By keeping the water content below the above ratio, the drying properties when applied as an ink can be improved. In the black coloring composition of the present invention, the solid content concentration is preferably 10 to 50% by weight. Particularly preferably 15 to 45% by weight, and most preferably 20 to 35% by weight. If it is too high, the viscosity of the black coloring composition will increase, which may impair film-forming properties. If it is too low, it may become difficult to mold the coating film, or the coloring density of the molded coating film may be low. Therefore, if the dispersant and / or the thermosetting resin described below are used in a form that includes them in a solvent or dispersion medium, the amount of solvent to be used should be determined by taking into account the amount of solvent or dispersion medium contained therein, so that the solid content concentration falls within the above range.

[0035] (thermosetting resin) The thermosetting resin that can be used in the black coloring composition of the present invention is not particularly limited. Examples of thermosetting resins include phenolic resins, amino resins, epoxy resins, unsaturated polyester resins, and acrylic resins. Epoxy resins, acrylic resins, and polyester resins used in paint applications are particularly suitable, and among these, acrylic resins, which have an acrylic structure, are preferred because they can form a coating film with high blackness. One type of thermosetting resin may be used, or two or more types may be used in combination. For example, Joncryl 67 (weight-average molecular weight: 12,500, acid value: 213), Joncryl 678 (weight-average molecular weight: 8,500, acid value: 215), Joncryl 586 (weight-average molecular weight: 4,600, acid value: 108), Joncryl 611 (weight-average molecular weight: 8,100, acid value: 53), Joncryl 680 (weight-average molecular weight: 4,900, acid value: 215), Joncryl 682 (weight-average molecular weight: 1,700, acid value: 238), Joncryl 683 (weight-average molecular weight: 8,000, acid value: 160), and Joncryl 690 (weight-average molecular weight: 16,500, acid value: 240) (all trade names, BASF Japan) can be suitably used. Among these, those with a weight-average molecular weight of 7,000 or more, and especially 8,000 or more, are preferred. In addition to these, there are various thermosetting resins used in black paints, and using those is also acceptable.

[0036] (Leveling agent) The black coloring composition of the present invention may contain a leveling agent as appropriate, for the purpose of preventing defects on the surface of the coating film, such as bubbles, craters, and pinholes. In the present invention, the leveling agent refers to resins such as acrylic, vinyl, fluorine, and silicone, which are commonly used as modifiers for the above purpose. There are no particular restrictions on the type of leveling agent or its mixing ratio; they can be selected appropriately depending on the application. Two or more different leveling agents can also be used in combination. Examples of leveling agents that can be used in the present invention include BYK-354, BYK-355, BYK-356, BYK-350, BYK-394, BYK-399, BYK-3440, BYK-3441, BYK-358N, BYK-361N (manufactured by Big Chemie Japan), Megafuck F410, Megafuck F477, Megafuck F510, Megafuck F552, Megafuck F554, and Examples include, but are not limited to, Gafac F555, Megafac F556, Megafac F557, Megafac F558, Megafac F559, Megafac F560, Megafac F561, Megafac F563, Megafac F565, Megafac F568, Megafac F569 (all from DIC Corporation), Polyflow KL-401, Polyflow KL-402 (both from Kyoeisha Chemical Co., Ltd.).

[0037] <Manufacturing method> The manufacturing method of the black coloring composition of the present invention is not particularly limited as long as it contains the essential components described above. However, it is extremely desirable to prepare a carbon black dispersion in advance by first dispersing carbon black and a dispersant in a liquid medium such as an organic solvent or water, then adding hollow silica to this carbon black dispersion and further dispersing it to obtain a black pigment dispersion containing carbon black and hollow silica, or by adding hollow silica and a thermosetting resin to the carbon black dispersion to obtain the black coloring composition of the present invention. This is because carbon black is a fine particle that is difficult to disperse, and by preparing a uniform dispersion in advance, it becomes easier to prevent the generation of coarse particles and obtain a coating film with a smooth and beautiful gloss. In particular, it is desirable to prepare carbon black dispersions and hollow silica dispersions in advance by dispersing carbon black and hollow silica in a dispersion medium, respectively, and then mix these with the thermoplastic resin. This is because hollow silica is a material with relatively small particle size and tends to aggregate, so keeping it in a dispersion state makes it easier to mix uniformly with other materials. Alternatively, these carbon black dispersions and silica dispersions may be mixed to form a black pigment dispersion, which may then be mixed with a thermoplastic resin. (Carbon black dispersion) 1. Method A carbon black dispersion can be prepared by mixing and dispersing carbon black that satisfies at least the above characteristics with any organic solvent and dispersant in the above proportions using a known method. The mixing and dispersion method is not particularly limited and can be carried out using known mixing and dispersion equipment such as a paint shaker, bead mill, planetary agitator, Henschel mixer, high-pressure homogenizer, or ultrasonic irradiator. 2. D50 In this case, the D50 of the dispersed particle size of carbon black in the carbon black dispersion is preferably 200 nm or less, more preferably 150 nm or less, and even more preferably 120 nm or less. By setting D50 to 150 nm or less, the number of coarse particles in the coating film and on the coating film surface can be suppressed, reducing the generation of scattered light and improving the blackness. 3. D90 The D90 of the carbon black dispersion particle size in the carbon black dispersion is preferably 300 nm or less, and particularly preferably 250 nm or less. Within this range, it is especially effective in suppressing the number of coarse particles in and on the surface of the coating film, reducing the generation of scattered light, and improving blackness. By setting the median diameter D50 of the carbon black in the carbon black dispersion to the above range, the brightness SCE L* and SCI L* of the resulting black colored composition, as well as the gloss at 60°, can be easily brought within the range described later. Furthermore, it is even more preferable if the 90% diameter D90 in the particle size distribution is also within the above range. 4. Viscosity The viscosity of the carbon black dispersion is preferably 1 Pa·s or less, and particularly preferably 100 mPa·s or less. Keeping the viscosity within this range ensures good handling during liquid transfer, stirring, and other manufacturing and usage processes. The viscosity of a carbon black dispersion can be measured by the following methods, but is not limited to these methods if similar results are obtained. Measuring device: E-type viscometer / cone plate type (RE-215L, manufactured by Toki Sangyo Co., Ltd.) Temperature: 25℃ The viscosity of a carbon black dispersion can be reduced by decreasing the carbon black content in the dispersion. Therefore, if the viscosity is outside the above range, the carbon black content can be appropriately adjusted within the range of the aforementioned blending ratio. 5. Concentration In the carbon black dispersion, the concentration of carbon black is preferably 2 to 30% by weight. Particularly preferably 5 to 20% by weight, and most preferably 10 to 15% by weight. If the concentration of carbon black in the dispersion is higher than this, the viscosity will be high and the dispersibility may decrease. If the concentration of carbon black in the dispersion is lower than this, the blending ratio of the black coloring composition will be limited, the design margin will be narrowed, and the coloring concentration may be lower.

[0038] (Hollow silica dispersion) The hollow silica dispersion can be prepared by mixing and dispersing at least hollow silica, any organic solvent, and a dispersant in the above-mentioned proportions using a known method. The mixing and dispersion method is not particularly limited, and any known mixing and dispersion device such as a paint shaker, bead mill, planetary agitator, Henschel mixer, high-pressure homogenizer, or ultrasonic irradiator may be used. As dispersion progresses, the hollow silica particles gradually begin to break. Since the SCI L* increases as the proportion of broken particles increases, it is desirable to disperse the particles moderately so that the degree of particle breakage does not increase excessively. For this reason, it is desirable to monitor the state of particle breakage and determine the dispersion time and conditions accordingly. This is as shown in Examples 6, 11, and 12 described later. The D50 of the silica dispersion particle size in a hollow silica dispersion is not particularly limited, but is usually 500 nm or less, particularly preferably 200 nm or less, even more preferably 150 nm or less, and most preferably 130 nm or less. The state of fracture in hollow silica particles is preferably such that the proportion of unfractured particles to the total number of particles is 30% or more, more preferably 50% or more, even more preferably 80%, and most preferably 90%. The proportion of fractured particles can be calculated by taking a photograph of the dispersion and counting the number of fractured and unfractured particles. (Measurements of D50 and D90) The D50 and D90 values ​​in these carbon black dispersions and hollow silica dispersions refer to those measured by the following method, but the measurement method is not limited to this if similar results can be obtained. Measurement device: Dynamic light scattering particle size distribution analyzer (Microtrac Wave II, manufactured by Microtrac-Bell) Settings: Particle refractive index 1.45, Solvent refractive index 1.38 Conditioning: Dilute the dispersion with methyl ethyl ketone until it reaches approximately 1000 times its original volume, within the measurement range of the instrument. Since the solid particles that may be present in the carbon black dispersion and silica dispersion are carbon black and silica, respectively, the measured D50 and D90 are indicators of the particle size distribution of the dispersed particles, which are the particle sizes that make up the carbon black and silica in the liquid. It can be inferred that the fact that both are within these ranges contributes to the effects of the present invention. Furthermore, since it is thought that these distributions are maintained without significant change even during the process of compounding the thermosetting resin, it can be inferred that this also contributes to the excellent performance of the black colored composition, and that such a state contributes to the performance of these excellent properties.

[0039] (Black colored composition) As described above, the black coloring composition of the present invention preferably consists of a mixture of at least a predetermined carbon black dispersion, a hollow silica dispersion, and a thermosetting resin. The method of adding the thermosetting resin is not particularly limited; it is sufficient to measure it and pour it into the other components. If additives such as leveling agents are used, they can be added at any time during the preparation of the black coloring composition.

[0040] (Physical properties of the black colored composition) The black coloring composition of the present invention can achieve a lightness SCE L* of 3.5 or less and a lightness SCI L* of 22.5 or less when applied as a coating film with a thickness of 3.0 μm. Furthermore, it can also achieve an SCI L* of 22.0 or less. The lightness values ​​SCE L* and SCI L* are Lab color system values ​​used to evaluate the blackness of an object. Compared to other values ​​used to evaluate blackness, such as the Y value in the XYZ color system, the Lab color system is designed to more closely approximate human vision, and the L component value in particular is considered to be extremely close to human perception of lightness. These lightness values ​​SCE L* and SCI L* refer to the reflectance values ​​of light measured using a spectrophotometer in the Lab color space, using the SCE method (a measurement method that removes specular reflection from reflected light) and the SCI method (a measurement method that includes specular reflection in reflected light). Reflected light is broadly classified into specular reflection and diffuse reflection. SCI L* represents the total amount of reflected light, including specular reflection, while SCE L* represents the amount of diffuse reflection, excluding specular reflection. The reason something appears black to the naked eye is because light is absorbed by the object; the lower the total internal reflection, the blacker it appears. Therefore, the lower the SCI L* value, the blacker it appears. Conversely, a high SCI L* value means that a large amount of light is absorbed, and if this value is too high, a phenomenon known as "white blurring" can occur, where the coating appears whitish and blurry even when viewed closely. Furthermore, when reflected light is diffused, it appears matte, while less diffusion results in a glossy finish. Therefore, the lower the SCE L*, the more glossy the surface. Therefore, it is believed that if the brightness values ​​of the coating film, SCE L* and SCI L*, can both be kept low, a black and glossy coating film can be achieved. When both values ​​are below the above values, it is possible to achieve a level of blackness that is perceived as extremely black by the human eye. In this invention, the SCE L* of the coating film can be 3.5 or less, the SCI L* can be 22.5 or less, and even the SCI L* can be 22.0 or less. In other words, an extremely black and glossy coating film can be obtained. Furthermore, as mentioned above, SCI L* is an indicator of pre-reflected light, and this invention provides a coating film that maintains gloss while having an unprecedentedly high degree of blackness.

[0041] The measurement method for SCE L* and SCI L* is not particularly limited, but as an example, they can be measured by the following method. First, the black coloring composition of the present invention is applied to a 1.1 mm thick soda glass plate using a bar coater #10, and dried in an oven at 80°C for 5 minutes to produce a coated plate with a film thickness of approximately 3.0 μm after drying. Then, the obtained coated plate is placed with the coated film side facing up on the black portion of an opacity test paper, and measured using a spectrophotometer (Konica Minolta Japan, Inc., "CM-26dG").

[0042] As shown in the examples described later, methods that reduce the primary particle size of carbon black, such as the method described in Patent Document 1, cannot reduce the SCI L* to 25.6 or less, and methods using large-particle hydrophobic silica cannot reduce the SCE L* to 25.2 or less. Furthermore, no known method has been able to reduce the SCI L* to 22.5 or less. In other words, these conventional methods have not been able to suppress the amount of either total reflected light or diffuse reflected light.

[0043] In contrast, the mechanism by which the present invention can simultaneously satisfy SCE L* 3.5 or less and SCI L* 22.5 or less is not fully clear. However, it is believed that the brightness within the above range is achieved because the coating film formed by the black coloring composition of the present invention has unique properties: it has few surface irregularities and does not easily generate scattered light, yet it can capture light into the coating film and reduce total reflected light.

[0044] Furthermore, GU is used as an indicator of gloss. The black coloring composition of the present invention can achieve a gloss of 60 GU or more at 60° when the coating film thickness is 3.0 μm, and can even achieve 80 GU or more. In this invention, 60° gloss refers to the gloss measured using a gloss meter in accordance with the JIS standard JIS Z 8741-1997, under conditions of 60° from the measurement surface. The method for measuring the gloss of the coating film in this invention is not particularly limited as long as it uses a gloss meter or a spectrophotometer with a gloss measurement function that conforms to the JIS standard JIS Z 8741-1997, but as an example, it can be measured by the method described below. First, the black coloring composition of the present invention is applied to a 1.1 mm thick soda glass plate using a bar coater #10, and dried in an oven at 80°C for 5 minutes to produce a coated plate with a film thickness of 3.0 μm after drying. Then, the obtained coated plate is placed with the coated side facing up on the black portion of an opacity test paper, and measured using a spectrophotometer (Konica Minolta Japan, Inc., "CM-26dG"). By keeping the gloss of the coating film at 60° within the above range, a lustrous shine that is perceived as extremely beautiful by the human eye is achieved.

[0045] The black coloring composition of the present invention can achieve a brightness of SCE L* and SCI L*, as well as a gloss of 60°, all within the above ranges. In other words, it can provide a black coloring composition that is extremely black and has a glossy finish, meeting the market demand for an extremely deep black color. Furthermore, for brightness SCE L* and SCI L*, and gloss at 60°, a portion can be sampled during the mixing and dispersion process of the above materials to prepare a black colored composition using the method described in the next paragraph. This composition can then be coated using the method described later, and each index can be measured and confirmed. Dispersion can be continued until the values ​​fall within the range described later.

[0046] <How to use> To use the black coloring composition of the present invention, it is sufficient to print or coat it onto the surface of the object. The black coloring composition of the present invention, when printed or coated onto the object, forms a coating film with excellent jet-black properties, contributing to improved aesthetics. As for the printing and coating methods, various printing methods such as spray printing, screen printing, and inkjet printing, as well as coating methods using brushes, spin coating, etc., are known methods that can be suitably used, but are not limited to these. After coloring, drying can be carried out using any method or apparatus, such as natural drying, heating in an oven or hot air dryer. In other words, by a method that includes the step of applying the black coloring composition to the object and curing it, the coating film of the present invention is obtained, (1) with a specific surface area of ​​250 m². 2 A coating film can be obtained that contains at least carbon black of 1 / g or more, silica with a D50 of 300nm or less, a dispersant, and a thermosetting resin, and a coating film of the same type as (1) and characterized in that, when measured from the coating surface, the lightness SCE L* is 3.5 or less, the SCI L* is 22.5 or less, and the gloss of the coating film at 60° is 60GU or more when measured from the coating surface. Here, the application method and curing method can be conventionally known methods without particular limitation. The application method here broadly includes printing, and the curing method can be conventionally known methods such as drying as described above without limitation. [Examples]

[0047] The present invention will be described in more detail below with reference to examples. Table 1 shows the physical properties and manufacturer names of the carbon black (CB), silica, and dispersant used in the examples and comparative examples. [Table 1]

[0048] (Preparation of carbon black dispersion 1) As carbon black, 15.0 parts by weight of Raben 5000U3 (manufactured by Birla Carbon Co., Ltd.), 37.5 parts by weight of TEGO DISPERS 670 (40% solids: 15 parts by weight, manufactured by Evonik Co., Ltd.) and 2.0 parts by weight of Solsperse 5000 (manufactured by Lubrizol Co., Ltd.) as dispersants, and 45.5 parts by weight of methyl ethyl ketone as an organic solvent were weighed out and placed in the same poly container (250 ml). An equal volume of 0.4-0.6 mm septum beads was then added to the poly container and placed in a paint shaker (manufactured by Asada Iron Works Co., Ltd.), where it was shaken and mixed for 3 hours to disperse the mixture. The resulting dispersion was designated as "Black Pigment Dispersion 1". The D50 and D90 values ​​of the obtained carbon black dispersion 1 were measured as follows. Measurement device: Dynamic light scattering particle size distribution analyzer (Microtrac Wave II, manufactured by Microtrac Bell Co., Ltd.) Conditioning: Dilute with methyl ethyl ketone until it enters the measuring range of the device, then measure. Settings: Particle refractive index 1.45, Solvent refractive index 1.38 The measurement results for D50 are shown in Table 2. The viscosity of carbon black dispersion 1 was measured by the following method. Measuring instrument: Cone plate viscometer (manufactured by Toki Sangyo Co., Ltd., "RE-215L") Conditioning: Undiluted solution Measurement temperature: 25℃ The results are shown in Table 2. [Table 2]

[0049] (Preparation of carbon black dispersions 2-6) The materials and mixing ratios of the carbon black dispersion were changed as shown in Table 2, and black pigment dispersions 2 to 6 were obtained in the same manner as black pigment dispersion 1. Viscosity, D50, and D90 were measured in the same manner as for carbon black dispersion 1. The measurement results are shown in Table 2. (Preparation of silica dispersion 1) 30.0 parts by weight of "JP-HS-070HM" (hollow silica manufactured by Sinosera), 2.25 parts by weight of Solspers 20000 (Lubrisol), 6.0 parts by weight of KBM-503 (silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd.), and 61.75 parts by weight of methyl ethyl ketone were weighed and placed in the same dispensing cup, and stirred at 500 rpm for 15 minutes using a dissolver. The resulting liquid was dispersed using a Staburst Lab (high-pressure homogenizer; manufactured by Sugino Machine Co., Ltd.). The resulting dispersion was designated as "Silica Dispersion 1". The viscosity, D50, and D90 of the silica dispersion were measured using the same method as the measurement of the black pigment dispersion described above. The results are shown in Table 3. (Preparation of silica dispersions 2-12) Silica dispersions 2 to 12 were obtained in the same manner as silica dispersion 1, except that silica listed in Table 3 was used instead of "JP-HS-070HM" and the dispersion conditions were changed from a starburst lab to a paint shaker. Viscosity, D50, and D90 were measured in the same manner as the black pigment dispersion described above. The results are shown in Table 3. [Table 3]

[0050] (Example 1) 5.3 parts by weight of carbon black dispersion 1, 2.7 parts by weight of silica dispersion 1, and 25.0 parts by weight of a thermosetting resin solution diluted to 25% by mass (a solution obtained by diluting Joncryl 611 (molecular weight: 8100, acid value: 53, manufactured by BASF) to 25% by weight with propylene glycol monomethyl ether acetate) were weighed and placed in a beaker. The mixture was then stirred by hand with a spoon for about 1 minute to obtain a black colored composition.

[0051] (Examples 2-12, Comparative Examples 1-6) A black colored composition was obtained in the same manner as in Example 1, except that the carbon black dispersion and silica dispersion were changed as shown in Table 4. In Comparative Example 1 only, the carbon black dispersion was prepared in parts 5.2 by weight and the silica dispersion in parts 2.6 by weight.

[0052] [Table 4]

[0053] (Fabrication of coated boards) The black coloring compositions of each example and comparative example were wet-coated onto a 1.1 mm thick soda glass plate using a bar coater #10, and dried in an oven preheated to 80°C for 5 minutes to obtain a coated plate with a film thickness of approximately 3.0 μm after drying.

[0054] (Measurement of coated plate) For each example and comparative example, the coated plate was placed with the coated surface facing upwards on the black portion of the opacity test paper. The jet blackness was visually confirmed, and the SCI L*, SCE L*, and GU at 60° on the coated surface were measured using a spectrophotometer (Konica Minolta Japan, Inc., "CM-26dG"). Based on visual inspection, items that showed no redness or yellowness, appeared extremely black even upon close inspection, and had a beautiful, glossy sheen were rated as "Excellent" (◎). Items that appeared black and generally had a glossy sheen were rated as "Good" (〇), while items that did not meet either of these criteria were rated as "Poor" (×). Furthermore, for the spectrophotometer measurement results, samples that met all of the following criteria were considered excellent (◎): SCI L* = 20.0 or less, SCE L* = 3.5 or less, and gloss at 60° = 60 GU or higher. Samples that met all of the following criteria were considered good (〇): SCI L* = 24.0 or less, SCE L* = 3.5 or less, and gloss at 60° = 60 GU or higher. Samples that did not meet any of these criteria were considered poor (×). The results are shown in Table 5 below.

[0055] [Table 5]

[0056] As shown in each example in Table 5, by using the black coloring composition of the present invention, it is possible to obtain a highly jet-black coating film that has extremely low brightness SCE L* and SCI L*, high blackness, and a glossy finish with a gloss of 60 GU or more at 60°.

[0057] The specific surface area of ​​this invention is 250 m². 2 Examples 1 to 12, which used a black coloring composition containing carbon black of 1 / g or more and hollow silica with a median diameter D50 of 300 nm or less, all met the requirements of an SCI L* of 24.0 or less, an SCE L* of 3.5 or less, and a gloss of 60° of 60 GU or more, demonstrating a combination of high blackness and gloss. In particular, Examples 1 to 9, which contained small-particle hollow silica, all had an SCI L* of 20.0 or less, exhibiting extremely excellent jet blackness and gloss even when observed visually. In contrast, the specific surface area is 250 m² 2 Comparative Example 1, which did not contain carbon black of 1 / g or more, had a high SCE L* of 6.2. Comparative Example 2, which did not contain silica, had a high SCI L* of 26.5. Comparative Examples 5 and 6, which used non-hollow silica, and Comparative Examples 3 and 4, which used hollow silica with a median diameter D50 exceeding 300 nm, had high SCI Ls of 27.1 and 26.4, respectively, and were not visually black. This is likely because the particle size of the hollow silica was too large, making it difficult for it to align on the surface of the coating, thus reducing the light-gathering ability of the coating surface. Furthermore, none of these comparative examples appear black to the naked eye, nor do they exhibit a generally glossy sheen, making it clear that they fall far short of the present invention even by visual inspection.

[0058] Furthermore, comparing Examples 6, 11, and 12, in which only the dispersion time was changed, it can be seen that increasing the dispersion time increased SCI L and decreased SCI E. An increase in SCI L means an increase in total reflected light, resulting in less absorbed light and a decrease in blackness. On the other hand, a decrease in SCE L means a decrease in diffuse reflected light and an increase in gloss. It is presumed that the decrease in blackness is due to the reduction in the amount of light absorbed as the hollow silica cracks and the hollow portion decreases, and also because the surface of the coating film becomes smoother as the hollow silica becomes smaller. This is supported by observing the SEM images of the hollow silica dispersions used in Examples 6, 11, and 12 shown in Figures 1-9, which show that the proportion of cracked silica increases as the dispersion progresses. Table 6 shows the ratio of uncracked hollow silica to cracked hollow silica in the hollow silica dispersions used in Examples 6, 11, and 12, as visually counted values ​​and their average values ​​for each SEM image (three fields of view selected and photographed for each dispersion). Furthermore, the relationship between the proportion of cracked hollow silica and SCI L* obtained in this way is shown in Figure 10, and it can be seen that there is a correlation, and the larger the proportion of cracked hollow silica, the higher the SCI L*. Furthermore, while extending the dispersion time reduces SCE L, the visual color does not improve significantly. This indicates that superior blackness and gloss are not achieved simply by reducing SCE L, but rather that the presence of a certain amount of hollow silica contributes to a high blackness and glossy hue (jet black).

[0059] [Table 6]

[0060] From the above, it has been shown that the black coloring composition of the present invention has extremely high jet blackness compared to the black coloring composition obtained by the prior art.

Claims

1. Specific surface area is 250 m² 2 A black pigment dispersion characterized by containing at least carbon black in amounts of 1 / g or more, hollow silica with a median diameter D50 of 300 nm or less, an organic solvent, and a dispersant.

2. A black coloring composition characterized by comprising the black pigment dispersion and thermosetting resin described in claim 1.

3. Specific surface area is 250 m² 2 A black coloring composition characterized by comprising carbon black of 1 / g or more, hollow silica with a median diameter D50 of 300 nm or less, an organic solvent, a dispersant, and a thermosetting resin.

4. The black coloring composition according to claim 3, characterized in that the weight concentration of carbon black [weight of carbon black / (solid weight of dispersant + solid weight of thermosetting resin + weight of carbon black + weight of hollow silica)] is 5 to 15%.

5. The black coloring composition according to claim 3, characterized in that when the coating film is 3.0 μm thick, the brightness is such that the brightness SCE L* is 2.0 or less and the SCI L* is 22.5 or less when measured from the coating film surface, and the gloss at 60° of the coating film is 70 GU or more when measured from the coating film surface.

6. The black coloring composition according to claim 3, characterized in that the weight ratio (A) / (B) of carbon black (A) to hollow silica (B) is in the range of 0.33 or more and 4.10 or less.

7. A method for producing a black colored composition, characterized by adding a thermosetting resin to the black pigment dispersion described in claim 1.

8. A coloring method characterized by printing or coating a substrate with the black coloring composition described in claim 3.

9. Specific surface area is 250 m² 2 A coating film characterized by containing at least carbon black of 1 / g or more, hollow silica with a median diameter D50 of 300 nm or less, a dispersant, and a thermosetting resin.

10. The coating film according to claim 9, characterized in that when measured from the coating film surface side, the brightness SCE L* is 2.0 or less, the SCI L* is 22.5 or less, and the gloss of the coating film at 60° is 70 GU or more when measured from the coating film surface.

11. A method for producing a coating film, characterized by comprising the step of applying the black coloring composition described in claim 3 to a substrate and curing it.

12. A black pigment dispersion characterized by containing at least carbon black (A) and hollow silica (B) with a median diameter D50 of 300 nm or less in a weight ratio (A) / (B) of 0.33 to 4.10, and containing a carbon black concentration of 2 to 30% by weight, wherein both carbon black (A) and hollow silica (B) with a median diameter D50 of 300 nm or less are dispersed in an organic solvent with a dispersion particle size D50 of 150 nm or less.

13. A method for producing a black pigment dispersion, characterized by mixing at least carbon black (A) and hollow silica (B) with a median diameter D50 of 300 nm or less in an organic solvent in a weight ratio (A) / (B) of 0.33 to 4.10, and in a carbon black concentration of 2 to 30% by weight, and dispersing until the D50 is 150 nm.

14. A method for producing a black colored composition, characterized by mixing at least carbon black (A) and hollow silica (B) with a median diameter D50 of 300 nm or less in an organic solvent in a weight ratio (A) / (B) of 0.33 to 4.10 and in a carbon black concentration of 2 to 30% by weight, dispersing until the D50 is 150 nm, and further adding a thermosetting resin in an amount such that the solid content concentration is 10 to 50% by weight of the entire composition.

15. A method for producing a black colored composition, characterized by adding hollow silica (B) with a median diameter D50 of 300 nm or less in a proportion such that the weight ratio (A) / (B) of carbon black (A) to hollow silica (B) with a median diameter D50 of 300 nm or less is 0.33 or more and 4.10 or less, and a thermosetting resin in an amount such that the solid content concentration is 10 to 50% by weight of the entire composition, to a black pigment dispersion in which 2 to 30% by weight of carbon black (A) is dispersed in an organic solvent.

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