Luster paint, luster coating film, luster laminated coating film, and coated article

Abstract

To provide a luster paint, a luster coating film, a luster laminated coating film, and a coated article that enable securing luster even with a comparatively small amount of indium particles incorporated.SOLUTION: A luster paint comprising scaly indium particles, a plasticizer, and a solvent, wherein the scaly indium particles are contained in an amount of 20 to 70 wt.% per 100 wt.% of solid content of the luster paint, and the plasticizer is an aliphatic dibasic acid ester and is contained in an amount of 10 to 85 wt.% per 100 wt.% of solid content of the luster paint.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a glitter paint, a glitter coating film, a glitter multi-layer coating film, and a coated article.

[0002] Electroless plating and vapor deposition are known methods for imparting brilliance (mirror finish) to plastic housings, etc. However, due to concerns about the environmental impact of plating and the need for expensive capital investment and low productivity of vapor deposition, various methods for creating mirror designs other than these have been investigated.

[0003] As a method for forming such a mirror design, for example, there has been a method using silver colloid or a silver complex solution.

[0004] However, these methods also have problems such as poor weather resistance and corrosion resistance, making it difficult to widely deploy them for industrial use.

[0005] Therefore, in recent years, a method of imparting brilliance by using a paint containing indium particles has been investigated.

[0006] For example, Patent Document 1 describes a coated article having: "(a) an undercoat coating layer formed from an undercoat paint, which is provided directly or indirectly on an article to be coated; and (b) a metal-containing coating layer, which is provided directly or indirectly on the undercoat coating layer, and which has a pigment weight concentration (PWC) of vapor-deposited indium thin film flakes of 72.7% or more, wherein the undercoat paint is (α) a two-component curable coating material containing an isocyanate compound as a curing agent; (β) acrylic lacquer, (γ) melamine-based paint, or (δ) an active energy ray-curable coating material containing a (meth)acrylic compound having two or more (meth)acryloyl groups in one molecule and forming a three-dimensional network structure by crosslinking and curing, and a polymerization initiator, wherein the (meth)acrylic compound is a diacrylate compound and a urethane (meth)acrylate; the average thickness of the vapor-deposited indium thin film flakes is 0.100 μm or less and 0.010 μm or more, and the cumulative 50% volume particle diameter D50 is 1.00 μm or less; a volumetric particle size distribution showing the relationship between the particle size of the vapor-deposited indium thin film flakes and the volume fraction of the vapor-deposited indium thin film flakes at that particle size, the volumetric particle size distribution having a first peak and a second peak having a particle size larger than that of the first peak; a volume V1 of the vapor-deposited indium thin film flakes at the first peak and a volume V2 of the vapor-deposited indium thin film flakes at the second peak satisfy (V1 / V2)×100≧25%; a particle size P1 of the deposited indium thin film flakes at the first peak and a particle size P2 of the deposited indium thin film flakes at the second peak satisfy the relationship 6.0≦P2 / P1≦12; The document states that "the coated article has a radio wave transmittance of 75% or more in both the 24 GHz band and the 78 GHz band," and that this makes it possible to "provide a coated article having a coating film that has excellent mirror design and radio wave transmittance and a low coating film formation temperature." [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 7146311 Summary of the Invention [Problem to be solved by the invention]

[0008] However, indium particles are a very expensive material, which tends to make paints and painted products expensive.

[0009] In order to ensure high brilliance, for example, as described in Patent Document 1 above, it has been necessary to incorporate indium particles (vapor-deposited indium thin film flakes in Patent Document 1) to such an extent that the pigment weight concentration (pigment weight % in 100% by weight of paint solids) exceeds 70% by weight. On the other hand, with regard to radio wave transmittance, which is one of the characteristics of coatings using indium particles, there was a tendency for the radio wave transmittance to decrease as the pigment weight concentration of indium particles increased.

[0010] The present invention has been made with the above-mentioned matters in mind, and aims to provide a bright paint, a bright coating film, a bright multilayer coating film, and a coated article that can ensure brightness even when the amount of indium particles blended is relatively small. [Means for solving the problem]

[0011] In order to solve the above problems, a bright paint comprising scaly indium particles, a plasticizer, and a solvent has been developed. Specific embodiments are listed below.

[0012] (Embodiment 1) A lustrous paint comprising scaly indium particles, a plasticizer, and a solvent, wherein the scaly indium particles are contained in an amount of 20 to 70% by weight based on 100% by weight of the solid content of the lustrous paint, and the plasticizer is an aliphatic dibasic acid ester and is contained in an amount of 10 to 85% by weight based on 100% by weight of the solid content of the lustrous paint. The content of the scaly indium particles is preferably 25 to 60% by weight, more preferably 30 to 50% by weight, based on 100% by weight of the solid content of the bright coating material.

[0013] This bright paint can ensure sufficient brightness even when the content of the scaly indium particles is relatively small, at 20 to 70% by weight, based on 100% by weight of the solid content of the bright paint. Furthermore, since the content of scaly indium particles is relatively small, radio wave transmittance is also excellent.

[0014] (Embodiment 2) The glitter paint according to embodiment 1, wherein the plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU).

[0015] This bright paint can ensure even greater brightness even when the content of scaly indium particles is relatively small.

[0016] (Embodiment 3) The glittering paint according to embodiment 1 or 2, which does not contain a polymer as a binder resin. Here, "polymer" refers to a material with a molecular weight of 10,000 or more. Furthermore, "not containing a polymer as a binder resin" means that the material does not substantially contain a "polymer" as a binder resin, and is intended to exclude, for example, a material in which a "polymer" is used as a surface treatment agent for scaly indium particles, resulting in the inclusion of a "polymer" in the lustrous paint. More specifically, for example, it means that the material does not contain 5% by weight or more of a polymer with a molecular weight of 10,000 or more per 100% by weight of the paint solids.

[0017] This bright paint can ensure even greater brightness even when the content of scaly indium particles is relatively small.

[0018] (Embodiment 4) The glittering paint according to any one of Embodiments 1 to 3, further comprising a dispersant. The content of the dispersant is preferably 5 to 30% by weight, more preferably 10 to 25% by weight, and most preferably 15 to 20% by weight, in terms of solid content, based on 100% by weight of the paint solid content.

[0019] This bright paint has high dispersibility of the scaly indium particles, and the paint has improved stability.

[0020] (Embodiment 5) The glittering paint according to any one of embodiments 1 to 4, wherein the plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU), and the paint contains a dispersant.

[0021] This bright paint can ensure even greater brightness even when the content of scaly indium particles is relatively small.

[0022] (Embodiment 6) A lustrous paint comprising scaly indium particles, a plasticizer, a dispersant, and a solvent, wherein the scaly indium particles are contained in an amount of 20 to 70% by weight based on 100% by weight of the solid content of the lustrous paint, and the plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU) and is contained in an amount of 10 to 85% by weight based on 100% by weight of the solid content of the lustrous paint. The content of the scaly indium particles is preferably 25 to 60% by weight, more preferably 30 to 50% by weight, based on 100% by weight of the solid content of the bright coating material.

[0023] This bright paint can ensure even greater brightness even when the blend amount of scaly indium particles is relatively small.

[0024] (Embodiment 7) A glittering coating film comprising scaly indium particles and a plasticizer, wherein the scaly indium particles are contained in an amount of 20 to 70% by weight based on 100% by weight of the glittering coating film, and the plasticizer is an aliphatic dibasic acid ester and is contained in an amount of 10 to 85% by weight based on 100% by weight of the glittering coating film. Here too, the content of the scaly indium particles is preferably 25 to 60% by weight, more preferably 30 to 50% by weight, based on 100% by weight of the solid content of the bright coating material.

[0025] This bright coating film can ensure sufficient brightness even when the content of the scaly indium particles is relatively low, 20 to 70% by weight, based on 100% by weight of the bright coating film. Furthermore, since the content of scaly indium particles is relatively small, radio wave transmittance is also excellent.

[0026] (Embodiment 8) The glossy coating film according to embodiment 7, wherein the plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU).

[0027] This bright coating film can ensure even greater brightness even when the content of flaky indium particles is relatively small.

[0028] (Embodiment 9) The glitter coating film according to embodiment 7 or 8, which does not contain a polymer as a binder resin. Here, "polymer" refers to a material with a molecular weight of 10,000 or more. Furthermore, "not containing a polymer as a binder resin" means that the material does not substantially contain a "polymer" as a binder resin, and this excludes, for example, a case in which a "polymer" is used as a surface treatment agent for scaly indium particles, resulting in the inclusion of a "polymer" in the lustrous paint. For example, this means that the material does not contain more than 5% by weight of a polymer with a molecular weight of 10,000 or more per 100% by weight of the paint solids.

[0029] This bright coating film can ensure even greater brightness even when the content of flaky indium particles is relatively small.

[0030] (Embodiment 10) The glittering coating film according to any one of embodiments 7 to 9, further comprising a dispersant. The content of the dispersant is preferably 5 to 30% by weight, more preferably 10 to 25% by weight, and most preferably 15 to 20% by weight, based on 100% by weight of the glittering coating film.

[0031] This bright coating film has high dispersibility of the scaly indium particles.

[0032] (Embodiment 11) The glossy coating film according to any one of embodiments 7 to 10, wherein the plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU), and the coating film contains a dispersant.

[0033] This bright coating film can ensure even greater brightness even when the content of flaky indium particles is relatively small.

[0034] (Embodiment 12) A glittering coating film comprising scaly indium particles, a plasticizer, and a dispersant, wherein the scaly indium particles are contained in an amount of 20 to 70% by weight based on 100% by weight of the glittering coating film, and the plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU) and is contained in an amount of 10 to 85% by weight based on 100% by weight of the glittering coating film. Here too, the content of the scaly indium particles is preferably 25 to 60% by weight, more preferably 30 to 50% by weight, based on 100% by weight of the solid content of the bright coating material.

[0035] This bright coating film can ensure even greater brightness even when the content of flaky indium particles is relatively small. Furthermore, since the content of scaly indium particles is relatively small, radio wave transmittance is also excellent.

[0036] (Embodiment 13) A glittering multilayer coating film comprising an undercoat coating film, a glittering coating film according to any one of embodiments 7 to 12 formed on the undercoat coating film, and a topcoat coating film formed on the glittering coating film.

[0037] This glittering multilayer coating film can ensure sufficient glittering even when the content of scaly indium particles in the glittering coating film is relatively low. Furthermore, since the content of flaky indium particles in the glittering coating is relatively small, the coating also has excellent radio wave transmittance.

[0038] (Embodiment 14) A coated article having the glittering multilayer coating film according to embodiment 13.

[0039] This coating can ensure sufficient brilliance. Furthermore, the multilayer coating film of the coated object has excellent radio wave transmittance. [Effects of the Invention]

[0040] According to the present invention, it is possible to provide a bright paint, a bright coating film, a bright multilayer coating film and a coated article that can ensure brightness even when the amount of indium particles blended is relatively small. DETAILED DESCRIPTION OF THE INVENTION

[0041] The following describes examples of the glitter paint, the glitter coating film, the glitter multi-layer coating film, and the coated article, but the present invention is not limited to the following embodiments.

[0042] First, the glittering paint will be illustrated. The glittering paint is composed of scaly indium particles, a plasticizer, and a solvent. In addition to these materials, the glittering paint may also contain a dispersant. Each element will be illustrated below.

[0043] 1. Scaly indium particles The scaly indium particles are a material for imparting brilliance to a brilliance coating film obtained by applying a brilliance paint, etc. As the scaly indium particles, for example, flaky indium particles made of indium with a purity of 95% or more can be used.

[0044] Scaly indium particles are indium particles having a generally flat surface and a generally uniform thickness in the direction perpendicular to the flat surface, with the thickness being very thin and the length of the flat surface (the length of the longest part) being very long. More specifically, the term "scaly" refers to indium particles having a very large aspect ratio (average particle diameter / thickness), for example, an aspect ratio of 2 to 1,000. Here, the average particle diameter refers to the 50% particle diameter (D50%) measured by a laser diffraction scattering method.

[0045] The thickness of the scaly indium particles is preferably 0.005 to 2 μm, more preferably 0.01 to 0.1 μm. Scaly indium particles with a thickness of 0.005 μm or more increase the gloss of the coating film. On the other hand, if the thickness of the scaly indium particles is 2 μm or less, the appearance of the coating film can be maintained in a good condition. In particular, if the thickness of the scaly indium particles is 0.1 μm or less, a coating film with a more metallic tone can be easily obtained. The thickness of the scaly indium particles is measured using an electron microscope.

[0046] The average particle size of the scaly indium particles is preferably 0.01 to 10 μm, more preferably 0.01 to 2 μm. If the average particle size of the scaly indium particles is 0.01 μm or more, scaly indium particles having a thickness of 0.01 μm or less are easily obtained. On the other hand, if the average particle size of the scaly indium particles is 10 μm or less, a smooth metallic coating film is easily obtained.

[0047] The scaly indium particles may be used in the form of a liquid or paste dispersed in a solvent such as an organic solvent. The surfaces of the scaly indium particles may be surface-treated with a surface treatment agent such as a fatty acid or a silane coupling agent, or may be coated with a transparent resin.

[0048] Examples of scaly indium particles include those obtained by pulverizing a vapor-deposited indium thin film obtained by vapor deposition or a rolled indium thin film obtained by rolling, etc. Among these, those obtained by pulverizing a vapor-deposited indium thin film are preferred, since a coating film with a more metallic appearance can be easily obtained. The vapor-deposited indium thin film can be obtained, for example, by vapor-depositing indium onto a substrate film such as polyethylene terephthalate to form a vapor-deposited indium thin film on the substrate film, and then peeling the formed vapor-deposited indium thin film from the substrate film. The vapor-deposited indium thin film can be crushed into irregular shapes to form flaky indium particles. As the scaly indium particles obtained in this manner, for example, Leaf Powder (registered trademark) manufactured by Oike Kogyo Co., Ltd. is commercially available.

[0049] These scaly indium particles (leaf powder manufactured by Oike Kogyo Co., Ltd.) are flaky indium particles made of indium with a purity of 95% or higher, and are characterized in that in a volume-based particle size distribution showing the relationship between the particle size of the indium particles and the volume fraction of the indium particles in that particle size, the flaky indium particles have a first peak and a second peak whose particle size is larger than the first peak, the volume V1 of the indium particles at the first peak and the volume V2 of the indium particles at the second peak satisfy the following formula: (V1 / V2) × 100≧25%, the particle size P1 of the indium particles at the first peak and the particle size P2 of the indium particles at the second peak satisfy the following formula: 6.0≦P2 / P1≦12, and the cumulative 50% volume particle size D50 of the indium particles is 0.70 μm or less.

[0050] 2. Plasticizers Next, examples of plasticizers will be described. In the glitter paint, an aliphatic dibasic acid ester is used as the plasticizer.

[0051] (1) Aliphatic dibasic acid ester The aliphatic dibasic acid ester can be obtained by esterifying an aliphatic dibasic acid such as adipic acid, azelaic acid, maleic acid, or sebacic acid with an alcohol. Examples of aliphatic dibasic acid esters that can be used include dibutyl adipate (DBA), diisobutyl adipate (DIBA), di-2-ethylhexyl adipate (DOA), diisononyl adipate (DINA), diisodecyl adipate (DIDA), bis-2-ethylhexyl azelaate (DOZ), dibutyl sebacate (DBS), di-2-ethylhexyl sebacate (DOS), diisononyl sebacate (DINS), dioctyl maleate (DOM), and diethyl succinate (DESU).

[0052] Among these aliphatic dibasic acid esters, dioctyl maleate (DOM) and diethyl succinate (DESU) are preferred in terms of brilliance. The mechanism by which the blending of dioctyl maleate (DOM) and diethyl succinate (DESU) improves brilliance is unclear, but it is speculated that the symmetrical molecular structure may be related. For example, it is thought that the molecular symmetry improves the orientation of the scaly indium particles.

[0053] 3. Dispersants Next, examples of dispersants will be described. Dispersants are optional components in the glittering paint. However, in order to suppress aggregation of the scaly indium particles and maintain a stable dispersion state in the glittering paint, it is preferable to add a dispersant.

[0054] In the glitter paint, any dispersant can be used as long as it can stably disperse scaly indium particles. However, blending a large amount of a dispersant with a high molecular weight (for example, a molecular weight exceeding 10,000) is not preferable in terms of glitter.

[0055] Generally, examples of dispersants include alkyl ether sulfates such as polyoxyethylene styrenated phenyl ether ammonium sulfate, polyoxyalkylene decyl ether sodium sulfate, polyoxyethylene tridecyl ether sodium sulfate, polyoxyethylene isodecyl ether ammonium sulfate, polyoxyethylene lauryl ether sodium sulfate, polyoxyethylene lauryl ether ammonium sulfate, polyoxyethylene alkyl ether sodium sulfate, polyoxyethylene oleyl cetyl ether ammonium sulfate, and polyoxyethylene oleyl cetyl ether sodium sulfate; alkyl sulfate ester salts; alkyl benzene sulfonates; alkyl phthalene sulfonates; polyoxyethylene alkyl ether sulfates; Known examples of alkyl phosphate salts include alkyl ether phosphate salts such as polyoxyethylene alkyl ether phosphate ester, polyoxyethylene lauryl ether phosphate ester, polyoxyethylene alkyl ether phosphate salt, polyoxyethylene tridecyl ether phosphate ester, and polyoxyethylene styrenated phenyl ether phosphate salt; alkyl ether acetate salts such as polyoxyethylene alkyl ether acetate salt and sodium polyoxyethylene lauryl ether acetate; and alkyl succinate salts such as disodium lauryl sulfosuccinate, disodium polyoxyethylene alkyl sulfosuccinate, disodium polyoxyethylene lauryl sulfosuccinate, and polyoxyethylene alkyl sulfosuccinate salts.

[0056] Commercially available dispersants include, for example, S-LEAM C-2091I (NOF Corporation), S-LEAM AD-374M (NOF Corporation), S-LEAM MP-071K (NOF Corporation), as well as S-LEAM SP-0201 (NOF Corporation), S-LEAM C20931 (NOF Corporation), S-LEAM 221P (NOF Corporation), S-LEAM AD-3172M (NOF Corporation), BYK-392 (BYK), DISPERBYK-2000 (BYK), DISPERBYK-2200 (BYK), DISPERBYK-2155 (BYK), and the like.

[0057] 4. Solvent Next, examples of solvents will be described. Solvents are used to disperse the scaly indium particles and plasticizers, and to adjust the viscosity of the glittering paint to optimize its applicability.

[0058] The solvent can be appropriately selected taking into consideration the compatibility with the plasticizer used in the glittering paint, the dispersibility of the scaly indium particles, the drying temperature, the drying time, etc. Solvents include organic solvents as well as water. When forming a glittering coating film on various plastic housings, it is desirable to select a solvent so that the glittering paint dries at a drying temperature of about 80±5°C and within 1 hour, preferably within 30 minutes.

[0059] Examples of organic solvents include alcohol-based solvents, ether-based solvents, ketone-based solvents, ester-based solvents, glycol ether-based solvents, phenol-based solvents, aliphatic or aromatic hydrocarbon-based solvents, aliphatic or aromatic chlorinated hydrocarbon-based solvents, sulfur-containing compound-based solvents, nitrogen-containing compound-based solvents, etc. These may be used alone or in combination of two or more.

[0060] 5. Glitter paint Next, an example of a glittering paint will be described. The glittering paint can be obtained by blending and mixing predetermined amounts of scaly indium particles, a plasticizer, and a solvent. In addition to these materials, a dispersant, an additive, etc. may also be added.

[0061] [Scaly indium particles] The scaly indium particles are blended in such a manner that the content of the scaly indium particles is 20 to 70% by weight based on 100% by weight of the solid content of the luster paint, preferably 25 to 60% by weight, more preferably 30 to 55% by weight, and most preferably 30 to 50% by weight based on 100% by weight of the solid content of the luster paint.

[0062] [Plasticizer] The aliphatic dibasic acid ester as a plasticizer is blended so that it accounts for 10 to 85% by weight (solid content) of the 100% by weight solid content of the glittering paint.The aliphatic dibasic acid ester as a plasticizer is blended so that it accounts for 15 to 80% by weight (solid content) of the 100% by weight solid content of the glittering paint. To explain the amount of plasticizer in more detail, if a dispersant, which will be described later, is not added, the amount of plasticizer is preferably 25 to 80% by weight, more preferably 30 to 75% by weight, and most preferably 33 to 72% by weight, based on 100% by weight of the solid content of the paint. On the other hand, when a dispersant, which will be described later, is blended, the amount of plasticizer blended is preferably 15 to 60% by weight, more preferably 20 to 55% by weight, and most preferably 25 to 50% by weight, based on 100% by weight of the solid content of the paint.

[0063] [Dispersant] The dispersant is an optional component. When a dispersant is added, it is preferably added in an amount of 30% by weight or less, more preferably 25% by weight or less, based on 100% by weight of the solid content of the glittering paint. When a dispersant is added, the lower limit of the amount added is not particularly limited, but it can be 10% by weight or more, or 15% by weight or more, based on 100% by weight of the solid content of the glittering paint.

[0064] [solvent] The solvent is blended so that the glossy paint has a viscosity that allows the desired coatability to be obtained. Note that coatability may vary depending on the type of solvent.

[0065] [others] The glitter paint may also contain small amounts of various additives. It is preferable that the glittering paint does not contain a polymer as a binder resin. "Polymer" refers to a material with a molecular weight of 10,000 or more. Furthermore, "does not contain a polymer as a binder resin" means that the paint does not substantially contain a "polymer" as a binder resin, and does not include, for example, a material in which a "polymer" is used as a surface treatment agent for scaly indium particles, resulting in the glittering paint containing a "polymer." For example, this means that the paint does not contain more than 5% by weight of polymers with a molecular weight of 10,000 or more per 100% by weight of the paint solids.

[0066] 6. Bright coating film Next, a glossy coating film will be illustrated. The glossy coating film can be obtained by applying the above-mentioned glossy paint to the surface of an object to be coated and then drying (volatilizing the solvent). The glossy coating film is composed of scaly indium particles and a plasticizer. In addition to these materials, the glossy coating film may also contain a dispersant, etc. When forming a glossy coating film on various plastic housings, the film is dried or cured at a temperature of about 80±5°C within one hour.

[0067] 7.Glitter laminated coating film Next, an example of a glittering multilayer coating film will be described. The glittering multilayer coating film is composed of an undercoat coating film, the above-mentioned glittering coating film formed on the undercoat coating film, and a topcoat coating film formed on the glittering coating film.

[0068] [Undercoat] The primer coating film is a coating film formed on the surface of an object to be coated, and is usually obtained by applying a primer paint to the object to be coated and drying it. There are no particular restrictions on the primer coating film, as long as it ensures adhesion to the object to be coated, has a certain degree of surface smoothness, and is easy to apply the glossy paint to.

[0069] As the primer paint, for example, a two-component clear paint can be used. Considering the formation of a multilayer coating film on various plastic housings, it is preferable to use a primer paint that dries or hardens at a drying temperature of about 80±5°C within one hour. The applied film thickness of the primer paint varies depending on the solid content of the primer paint, but is preferably 10 to 35 μm, more preferably 20 to 25 μm.

[0070] [Glitter coating film] The above-mentioned glitter paint is applied onto the undercoat film and dried to form a glitter paint film. The glitter paint and glitter paint film are as described above, and therefore further explanation will be omitted. The infrared absorptivity of the glittering paint varies depending on the solid content of the glittering paint, but is preferably 30 to 80%, more preferably 45 to 75%. Because the glittering paint film has a thickness of 1 μm or less, an electromagnetic film thickness gauge cannot be used. After extensive investigation, we found that the infrared absorptivity is proportional to the thickness of the glittering paint film, and quantified it as described above. The infrared absorptivity was measured using an optical transmittance meter DST-2501 manufactured by Toa System Create Co., Ltd. A transparent acrylic resin plate was used as the measurement sample, and the glittering paint was applied to it and dried to form a glittering paint film, after which the infrared absorptivity was measured. The glittering paint was applied using a spray gun.

[0071] [Topcoat] The topcoat film is a coating film formed on the surface of the glossy coating film, and is usually obtained by applying a topcoat paint to the glossy coating film and drying it. The topcoat film is not particularly limited as long as it ensures adhesion to the glossy coating film and has a certain degree of surface smoothness.

[0072] As the topcoat paint, for example, a two-component clear paint can be used. Considering the formation of a multilayer coating film on various plastic housings, it is preferable to use a topcoat paint that dries or hardens at a drying temperature of about 80±5°C within one hour. The applied film thickness of the topcoat paint is preferably 8 to 32 μm, more preferably 18 to 22 μm, depending on the solid content of the topcoat paint. 8. Painted objects

[0073] Finally, an example of a coated object will be described. A coated object is an object to be coated in which the multilayer coating film is formed on a part or all of the object. The area where the multilayer coating film is formed has high brilliance.

[0074] The object to be coated on which the multilayer coating film is formed is not particularly limited, and examples thereof include the exterior and interior parts of automobiles, automobile parts such as bumpers and front grilles, exterior parts of electrical appliances such as mobile phones and information terminal devices, housings of makeup palettes and cosmetic palettes, and fishing tackle such as reels and lures.

[0075] The material of these objects to be coated is not particularly limited, but examples thereof include various metal materials such as iron and aluminum, various resin materials such as ABS resin and polyethylene resin, various plastic materials such as FRP, various inorganic materials such as glass and cement, and various fibrous materials such as paper and cloth. [Example]

[0076] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, the ratios and the like are based on weight.

[0077] Example 1 A glittering paint was prepared based on the formulation of Example 1 in Table 1 below. In Table 1, the figures in parentheses for the blend amounts of indium, plasticizer, and dispersant are the amounts of solids. The scaly indium particle content (wt % of the solid content) in Tables 1 and 2 is the content (wt %) of scaly indium particles in 100 wt % of the solid content of the luster paint, and is generally referred to as the pigment weight concentration (PWC). The plasticizer content (wt %) is the content (wt %) of plasticizer solids in 100 wt % of the luster paint solid content.

[0078] First, a scaly indium particle solution (product number: Leaf Powder 49CJ-1120, manufactured by Oike Industrial Co., Ltd.) was mixed with dioctyl maleate (product number: DOM, manufactured by Daihachi Chemical Industry Co., Ltd.), an aliphatic dibasic acid ester, as a plasticizer, and then thinner No. 5600 (manufactured by Ohashi Chemical Industry Co., Ltd.) was mixed as a solvent (diluent). The mixture was then thoroughly stirred until homogeneous, yielding the lustrous paint of Example 1. The 100% by weight of the scaly indium particle solution contains 20% by weight of scaly indium particles. In addition, in order to ensure blending accuracy, the plasticizer and dispersant (described later) are blended in the form of a solution (10% solids) diluted 10 times with thinner No. 5600.

[0079] Then, a primer paint was applied to the ABS resin plate, which was the object to be painted, and then dried to form a primer coating film.On top of that, the glossy paint of Example 1 was applied and dried to form a glossy coating film. The primer paint used was Fine Finish (NXT) primer clear (manufactured by Ohashi Chemical Industry Co., Ltd.) mixed with hardener IP-60 (manufactured by Ohashi Chemical Industry Co., Ltd.) and thinner No. 6820 (manufactured by Ohashi Chemical Industry Co., Ltd.) in a weight ratio of 60:10:48. This was applied to an ABS resin plate (film thickness 20-25 μm) and dried at 80°C for 30 minutes to obtain a primer coating. A glitter paint was applied onto the obtained primer coating film and dried at 80°C for 30 minutes to obtain a glitter coating film. The infrared absorptivity of the glitter coating film was 45 to 75%.

[0080] Finally, a topcoat was applied to the resulting glossy coating film, which was then dried to form a topcoat film, yielding a glossy multilayer coating film. The topcoat was a mixture of Fine Finish (NXT) Clear Topcoat (Ohashi Chemical Industry Co., Ltd.), hardener IP-60 (Ohashi Chemical Industry Co., Ltd.), and thinner No. 6820 (Ohashi Chemical Industry Co., Ltd.) in a weight ratio of 80:10:88. This was applied to the glossy coating film (film thickness 18-22 μm) and dried at 80°C for 30 minutes to form a topcoat film. As a result, a glittering multi-layer coating film consisting of the undercoat coating film, the glittering coating film and the topcoat coating film was obtained.

[0081] The resulting multilayer coating film was evaluated for gloss value, L value, and adhesion, as well as for the appearance of the coating film.

[0082] The gloss value was measured in accordance with JIS Z8741-1997 Specular Gloss Measurement Method. The measurement was performed using a MULTI GLOSS 268 Plus made by Konica Minolta, Inc., at measurement angles of 20°, 60°, and 85°. A value of 700 or more at a measurement angle of 20° was evaluated as ○.

[0083] The L value was measured using a spectrophotometer CM-600d manufactured by Konica Minolta, Inc. A measured value of 60 or more was evaluated as ○.

[0084] Adhesion was evaluated using the so-called cross-cut tape peel test (JIS K5600-2014), and results without peeling were rated as ○. The appearance of the coating film was evaluated only for reference, as it can be affected by factors such as application conditions, and coatings with poor appearance were rated as △, even if other evaluations were good.

[0085] The multilayer coating film using the glitter paint of Example 1 was evaluated as having very good results.

[0086] [Table 1]

[0087] (Example 2) (Example 3) This is an example in which the blending amount of dioctyl maleate as a plasticizer is increased based on the blending amount of Example 1.

[0088] The multilayer coating films using the glitter paints of Examples 2 and 3 both had very good evaluation results.

[0089] (Example 4) (Example 5) (Example 6) This example is based on the formulation of Example 1, but the plasticizer was changed from dioctyl maleate to diethyl succinate (Daihachi Chemical Industry Co., Ltd., "Product No.: DESU"), which is also an aliphatic dibasic acid ester, and the amount of plasticizer added was varied.

[0090] The multilayer coating films using the glitter paints of Examples 4, 5 and 6 all had very good evaluation results.

[0091] (Comparative Example 1) (Comparative Example 2) (Comparative Example 3) This example is based on the formulation of Example 1, but the plasticizer was changed from dioctyl maleate, an aliphatic dibasic acid ester, to an adipic acid polyester (DIC Corporation, Product Number: W-2340-S), and the amount added was varied.

[0092] The multilayer coating films using the glitter paints of Comparative Examples 1, 2 and 3 did not give very good evaluation results.

[0093] (Comparative Example 4) to (Comparative Example 12) These are comparative examples in which various dispersants were added in place of the plasticizer and the amounts added varied based on the formulation of Example 1. The dispersants used were S-LEAM C-2091I (NOF Corporation), S-LEAM MP-071K (NOF Corporation), and S-LEAM AD-374M (NOF Corporation).

[0094] Of Comparative Examples 4 to 12, the multilayer coating film using the lustrous paint of Comparative Example 7 was relatively good in terms of gloss value and L value, but the system containing only a dispersant did not receive a very good evaluation compared to the system containing a plasticizer.

[0095] (Comparative Example 13) This is a comparative example in which neither a plasticizer nor a dispersant is blended.

[0096] The multilayer coating film using the glitter paint of Comparative Example 13 also did not give very good evaluation results.

[0097] From the above, it was found that the evaluation results of systems containing aliphatic dibasic acid esters, dioctyl maleate (DOM) or diethyl succinate (DESU), as plasticizers were good.

[0098] Next, a dispersant was added to the plasticizer-based system and a prototype evaluation was carried out. The formulation and evaluation results are shown in Table 2.

[0099] [Table 2]

[0100] Example 7 This system is based on the formulation of Example 1, but with the addition of a dispersant.

[0101] Although the multilayer coating film using the lustrous paint of Example 1, which did not contain a dispersant, showed better results, the multilayer coating film using the lustrous paint of Example 7 also showed very good evaluation results.

[0102] Example 8 This system is based on the formulation of Example 7, but with an increased amount of plasticizer.

[0103] The multilayer coating film using the glitter paint of Example 8 also showed very good evaluation results.

[0104] (Example 9) (Example 10) (Example 11) Based on the formulation of Example 7, this system changes the type of dispersant and the amount of dispersant added.

[0105] The multilayer coating films using the glitter coating materials of Examples 9, 10, and 11 all showed favorable evaluation results.

[0106] (Example 12) to (Example 17) This example is based on the formulations of Examples 7 to 11, but the plasticizer was changed from dioctyl maleate to diethyl succinate (Daihachi Chemical Industry Co., Ltd., "Product No. DESU"), which is also an aliphatic dibasic acid ester.

[0107] The multilayer coating films using the glitter coating materials of Examples 12 to 17 also all showed good evaluation results.

[0108] (Comparative Example 14) to (Comparative Example 18) Based on the formulations of Examples 7 to 11, this system changes the plasticizer from dioctyl maleate, an aliphatic dibasic acid ester, to an adipic acid polyester (DIC Corporation, Product Number: W-2340-S).

[0109] The multilayer coating films using Comparative Examples 14 to 18, which are systems in which an adipic acid-based polyester was blended as a plasticizer, did not generally give very good evaluation results.

[0110] In addition, preliminary studies have shown that photoluminescent paints containing materials with high molecular weights are prone to cloudiness and reduced color development through verification experiments in which polymers are added.

[0111] Furthermore, when the multilayer coating films of each example were checked for radio wave transmittance (attenuation and transmittance in the 24 GHz band and the 78 GHz band), good results were obtained in all cases.

[0112] The present invention has been described above with reference to specific embodiments and examples, but the present invention is not limited to the above embodiments, and various changes and modifications can be made by those skilled in the art without departing from the scope of the claims attached to the application of this application.

Claims

1. scaly indium particles; A plasticizer, A glitter paint comprising: The scaly indium particles are The content of the luster paint is 20 to 70% by weight based on 100% by weight of the solid content of the luster paint, The plasticizer is It is an aliphatic dibasic acid ester and is contained in an amount of 10 to 85% by weight based on 100% by weight of the solid content of the glittering paint. Bright paint.

2. The plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU), The bright paint according to claim 1.

3. Does not contain a polymer as a binder resin. The bright paint according to claim 1.

4. including a dispersant, The bright paint according to claim 1.

5. The plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU), including a dispersant, The bright paint according to claim 1.

6. scaly indium particles; A plasticizer, a dispersant; and A glitter paint comprising: The scaly indium particles are The content of the luster paint is 20 to 70% by weight based on 100% by weight of the solid content of the luster paint, The plasticizer is Dioctyl maleate (DOM) or diethyl succinate (DESU), which is contained in an amount of 10 to 85% by weight based on 100% by weight of the solid content of the bright paint. Bright paint.

7. scaly indium particles; A glitter coating film comprising a plasticizer, The scaly indium particles are The content of the luster coating film is 20 to 70% by weight based on 100% by weight of the luster coating film, The plasticizer is an aliphatic dibasic acid ester contained in the glossy coating film at 10 to 85% by weight; Bright coating film.

8. The plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU); The glittering coating film according to claim 7.

9. Does not contain a polymer as a binder resin. The glittering coating film according to claim 7.

10. including a dispersant, The glittering coating film according to claim 7.

11. The plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU), including a dispersant, The glittering coating film according to claim 7.

12. scaly indium particles; A plasticizer, A glitter coating film comprising a dispersant, The scaly indium particles are The content of the luster coating film is 20 to 70% by weight based on 100% by weight of the luster coating film, The plasticizer is dioctyl maleate (DOM) or diethyl succinate (DESU), which is contained in an amount of 10 to 85% by weight based on 100% by weight of the glitter coating film; Bright coating film.

13. A primer coating and The glittering coating film according to any one of claims 7 to 12 formed on the undercoat coating film; a topcoat coating film formed on the glossy coating film; A glossy multilayer coating film comprising:

14. A coated article having the glittering multilayer coating film according to claim 13.

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