JP2006297225A - Method of forming porcelain color tone coating film and porcelain color tone coated product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming a porcelain color tone coating film exhibiting porcelain color tone having deep and pale blue feeling, and a porcelain color tone coated product. <P>SOLUTION: In the method of forming the porcelain color tone coating film, (I) a color base coating film showing L* of 60-100, a* of (+1.5) to (-1.5) and b* of (-1) to (-20) in a color gamut of L*a*b* system of a dry coating film to be formed, (II) a mica flake pigment-containing coating film containing a white mica flake pigment (a) and a blue interference mica flake pigment (b) in (a)/(b)=4/6-7/3 (mass ratio) and (a)+(b)=1-30 mass% (in coating film solid portion) are formed on a base material in this order by a 3 coat 1 bake system or 3 coat 2 bake system. The porcelain color tone coated product is obtained by this method. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for forming a ceramic toning coating film exhibiting a “ceramic tone color with a sense of depth and pale blue” which is a pale blue porcelain tone color of celadon or blue white porcelain, and a ceramic toning coating product.
In the present invention, the “tone-like and pale blue-tone ceramic tone” is a glaze based on a transparent color close to light blue made from ash as a porcelain made from a clay made of clay by crushing stone (Yuyaku) is a pale blue or pale green ceramic celadon texture, or a white base represented by Imari ware, with transparent glazing, and baked white porcelain and celadon porcelain. At the same time as expressing the texture of blue-white porcelain, which is a pale blue porcelain like the middle, the subtle changes in “blueness” and “whiteness” when observing the formed coating film while changing the angle A deep color tone that is visible while crossing.

The following method has been proposed as a method for expressing a ceramic-like design by forming a coating film.
For example, Patent Document 1 discloses a ceramic style in which paint A (colored base paint) and paint B, which have relatively higher viscosities than paint B (clear paint), are sprayed at the same time and the film thickness varies depending on the location. A coating method suitable for an inner wall or an outer wall of a building or the like that obtains a coating film having the appearance (structure) is disclosed.
Patent Document 2 discloses a color base layer having a Munsell lightness of 5 or more and a fine balloon made of glass or plastic as an upper layer as a coating film structure having a ceramic tone used for car body painting of automobiles. A structure provided with a large number of clear layers is disclosed, and it is described that the diffused reflection of light due to internal reflection in the balloon and the color of the color base layer combine to generate a ceramic-like color that shines lightly. .
Furthermore, Patent Document 3 discloses that acrylic resin is 45 to 50% by weight, thinner is 40 to 45% by weight, and additives such as a surface tension adjusting agent and an anti-settling agent are used as a coating laminate used for overcoating of a vehicle body. The glass bead base layer, which is a paint in which 5 to 1.0% by weight of the resin system is mixed with 2 to 5% by weight of glass beads having a diameter of 50 to 100 μm, is adjusted to a slightly lighter color than Sky Blue. In other words, the glass beads included in the glass bead base layer are slightly refracted and reflected by the glass beads contained in the glass bead base layer, resulting in a celadon appearance (color tone). ) Is obtained.

  However, the painting method of Patent Document 1 is a method of forming a ceramic-like structural appearance with a coating film, and since the color gamut of the paint to be used is not set, “ceramic tone with a sense of depth and light blue” Cannot be obtained. In the painting method of Patent Document 2, the lightness of the color base coating film is set, but the color gamut of the clear layer using the fine balloon is not set, and the fine balloon having no interference is used. Therefore, it is not possible to obtain a “ceramic tone with deep and light blue”. In the coating method of Patent Document 3, although the color base layer is light blue, the color gamut of the glass bead base layer in which 2 to 5% by weight of the glass beads are mixed is not set, and glass beads having no interference are used. Therefore, it is not possible to obtain a “ceramic tone with deepness and pale blue”.

Japanese Patent Laid-Open No. 11-76917 Japanese Patent Laid-Open No. 5-43824 JP-A-1-118576

  An object of the present invention is to provide a ceramic toning coating film forming method and a ceramic toning coating product exhibiting a “ceramic tone color tone with a feeling of depth and pale blue”.

As a result of intensive studies in view of the above-mentioned problems, the present inventors have found that in a 3 coat 1 bake or 3 coat 2 bake coating system, an L ^* a ^* b ^* display system of a dry coating film formed on a substrate. In the color gamut, the L ^* value is 60 to 100, the a ^* value is +1.5 to −1.5, and the b ^* value is −1 to −20, that is, the color base has high brightness, close to achromatic color, and bluish Form a coating film without curing the color base coating film in a 3-coat 1-bake coating system, or cure the color base coating film in a 3-coat 2-bake coating system, and then apply a mica flake pigment-containing coating film to white mica flakes. Pigment (a) and blue interference mica flake pigment (b) are mixed into (a) / (b) = 4/6 to 7/3 (mass ratio) and (a) + (b) = 1 to 30 mass% ( Mycuffs contained in the solid content of the coating) By using chromatography click pigment paints, it found that the ceramic tone color coating exhibiting "deepness and light blue sense of ceramic tone color" is obtained, leading to the present invention.

That is, the present invention
1. A ceramic toning coating film forming method for sequentially performing the following steps (1) to (4) (hereinafter also referred to as A invention (3-coat 1-bake coating system)):
(1) L ^* value is 60 to 100, a ^* value is +1.5 to -1.5 and b in the color gamut of the dry coating film formed in the L ^* a ^* b ^* display system with respect to the substrate. ^* Step of forming a color base coating film having a value of -1 to -20;
(2) The white mica flake pigment (a) and the blue interference mica flake pigment (b) with respect to the color base coating film are (a) / (b) = 4/6 to 7/3 (mass ratio) and A step of forming a mica flake pigment-containing coating film containing (a) + (b) = 1-30 mass% (in the solid content of the coating film);
(3) A step of forming a clear coating film on the mica flake pigment-containing coating film;
(4) a step of curing the color base coating film, the mica flake pigment-containing coating film, and the clear coating film;
2. Ceramic toning coating film forming method for sequentially performing the following steps (1) to (4 ′) (hereinafter also referred to as B invention (3-coat 2-bake coating system)):
(1) L ^* value is 60 to 100, a ^* value is +1.5 to -1.5 and b in the color gamut of the dry coating film formed in the L ^* a ^* b ^* display system with respect to the substrate. ^* Step of forming a color base coating film having a value of -1 to -20;
(1 ′) Step of curing the color base coating film (2) For the color base coating film, white mica flake pigment (a) and blue interference mica flake pigment (b) are (a) / (b) = A step of forming a mica flake pigment-containing coating film containing 4/6 to 7/3 (mass ratio) and (a) + (b) = 1 to 30 mass% (in the solid content of the coating film);
(3) A step of forming a clear coating film on the mica flake pigment-containing coating film;
(4 ′) a step of curing the mica flake pigment-containing coating and the clear coating;
3. In the color gamut in the L ^* a ^* b ^* display system of the dried coating film on which the color base coating film is formed, the L ^* value is 70 to 100, the a ^* value is +1.5 to −1.5, and the b ^* value. -1 to -6 ceramic toning coating film forming method;
4. Ceramic toning paint painted by the above ceramic toning coating film forming method;
I will provide a.

According to the method for forming a ceramic color tone coating film of the present invention, it is possible to obtain a ceramic color tone paint exhibiting a design exhibiting a “certain color tone with a sense of depth and light blue”.
The ceramic toning coating film of the present invention has an L ^* value of 60 to 100 and an a ^* value of +1.5 in the color gamut of the dry coating film formed on the base material in the L ^* a ^* b ^* display system. A color base coating film having a value of ˜−1.5 and a b ^* value of −1 to −20, a white mica flake pigment (a), and a blue interference mica flake pigment (b) (a) / (b) = 4 / 6-7 / 3 (mass ratio) and (a) + (b) = 1 to 30% by mass (in the solid content of the coating film) . Therefore, when the ceramic toning coating film of the present invention is viewed from above, the color tone of the mica flake pigment-containing coating film expressed by the white mica flake pigment and the blue interference mica flake pigment is visible through the coating film. A composite color with the color tone of the color base coating film of the specified color gamut is developed, and at the same time as `` texture of celadon '' and `` texture of blue and white porcelain '', the formed composite coating film was observed while changing the angle Sometimes, the “blueness” and “whiteness” are perceived to cross each other while slightly changing, and the effect of the present invention is considered to be “ceramic tone with deepness and pale blueness”. It is done.
Since the coating film obtained by the present invention exhibits the above-mentioned design, it is preferably used in fields requiring a ceramic-like color tone such as a vehicle outer plate such as an automobile or a two-wheeled vehicle, an outer surface of a container, a coil coating, and the home appliance industry.

Hereinafter, embodiments of the present invention will be described in detail.
<Ceramic-tone coating film formation method>
The method of forming a ceramic-tone coating film of the present invention is as follows:
In the invention A, (1) L ^* value is 60 to 100 and a ^* value is +1.5 to −1 in the color gamut in the L ^* a ^* b ^* display system of the dried coating film formed on the substrate. Forming a color base coating film having a .5 and b ^* value of −1 to −20 (first step);
(2) The white mica flake pigment (a) and the blue interference mica flake pigment (b) with respect to the color base coating film are (a) / (b) = 4/6 to 7/3 (mass ratio) and (A) + (b) = 1 to 30% by mass (in the solid content of the coating film) A step of forming a mica flake pigment-containing coating (second step);
(3) A step of forming a clear coating on the mica flake pigment-containing coating (third step);
(4) a step of curing the color base coating film, the mica flake pigment-containing coating film and the clear coating film (fourth process);
In the invention B, as a step between the steps (1) and (2) of the invention A, (1 ′) a step of curing the color base coating film (step 1 ′); and step (3) of the invention A As the next step, (4 ′) the step of curing the mica flake pigment-containing coating and the clear coating (fourth step) is sequentially performed.

[First step]
In the ceramic toning coating film forming method of the present invention, as a first step, the L ^* value is 60 to 60 in the color gamut of the dry coating film to be formed on the L ^* a ^* b ^* display system. A color base coating film having an a ^* value of +1.5 to −1.5 and a b ^* value of −1 to −20 is formed.
If the above L ^* , a ^* and b ^* are out of the above range, a “ceramic tone having a feeling of depth and light blue” cannot be exhibited. More preferably, the L ^* value is 70 to 100, the a ^* value is +1.5 to −1.5, and the b ^* value is −1 to −6.
The L ^* value 100 is an upper limit value for brightness display. Here, the L ^* value, the a ^* value, and the b ^* value mean an index that represents an object defined in JIS Z8729 in color, and the L ^* value, the a ^* value, and the b ^* value are colorimeters (for example, (Trade name “SM Computer”, manufactured by Suga Test Instruments Co., Ltd.).

The base material is not limited, and metals such as iron, aluminum, copper, and alloys thereof; inorganic materials such as glass, cement, and concrete; polyethylene resin, polypropylene resin, and ethylene-vinyl acetate copolymer Resins, polyamide resins, acrylic resins, vinylidene chloride resins, polycarbonate resins, polyurethane resins, epoxy resins and other plastic materials such as various FRPs; natural or synthetic materials such as wood and fiber materials (paper, cloth, etc.), etc. Is mentioned.
In the ceramic toning coating film forming method of the present invention, a color base coating film of a specific color gamut is formed on the base material directly or through a base coating film, but is coated by the ceramic toning coating film forming method of the present invention. When the base material to be used is an automobile body or a part, it is preferable to preliminarily coat the base material by chemical conversion treatment, electrodeposition coating, or the like, and if necessary, intermediate coating or the like. The intermediate coating is performed for concealing the base, imparting chipping resistance, and ensuring adhesion with the top coat, and may also be used as a color base coating film.

The L ^* value is 60 to 100, the a ^* value is +1.5 to −1.5, and the b ^* value is −− in the color gamut of the dry coating film formed on the base material in the L ^* a ^* b ^* display system. For the formation of the color base coating film of 1 to -20, a color base paint containing a color pigment whose kind and amount are selected so as to be in the above color gamut is used.
In the case where the base material is undercoated with an undercoating or intermediate coating, etc., the obtained undercoat is wet on wet (W / W) or wet on dry (W / D). The first glittering paint can be applied by the method.
The W / W method is a coating method in which a base coating is applied and then dried by air drying or the like, and is applied to an uncured or semi-cured base coating film. On the other hand, the W / D method is This is a coating method in which the base coating film baked and cured is repeatedly applied.

  Examples of the color pigment contained in the color base paint include those conventionally used for paint, and examples of such an organic pigment include azo lake pigments, phthalocyanine pigments, indico pigments, and perylene. Pigments, quinophthalone pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, metal complex pigments and the like, and examples of inorganic pigments include yellow iron oxide, bengara, titanium dioxide, and carbon black. Can be mentioned.

The total content of the color pigments contained in the color base paint is preferably 0.01 to 70% by mass of PWC (Pigment Weight Content), and if less than 0.01% by mass, “a ceramic tone with a sense of depth and light blue” “Color tone” may not be obtained, and if it exceeds 70% by mass, the coating film appearance may be deteriorated.
As long as the effects of the present invention are not impaired, extender pigments conventionally used for paints can be used as necessary. Examples of such extender pigments include talc, calcium carbonate, precipitated barium sulfate, and silica.

The color base paint disperses the color pigment and the inorganic pigment or an extender pigment used as required by a vehicle, and is composed of a resin for forming a coating film and a crosslinking agent as required.
Examples of the resin for forming a coating film constituting the vehicle include (a) acrylic resin, (b) polyester resin, (c) alkyd resin, (d) fluororesin, (e) epoxy resin, and (f) polyurethane resin. (G) polyether resins and the like, and acrylic resins and polyester resins are particularly preferably used from the viewpoint of weather resistance. These can be used in combination of two or more. In addition, the coating film-forming resin includes a curable type and a lacquer type, and usually a curable type is used. In the case of a curable type, it is used by mixing with a crosslinking agent such as an amino resin, a (block) polyisocyanate compound, an amine, a polyamide, or a polyvalent carboxylic acid, and the curing reaction is carried out at room temperature or at room temperature. Can be advanced. Moreover, it is also possible to use together the coating-film formation resin of the type which does not have curability, and the coating-film formation resin of a type which has curability.

  As said (a) acrylic resin, the copolymer of an acryl-type monomer and another ethylenically unsaturated monomer is mentioned. Acrylic monomers that can be used for the copolymerization include methyl, ethyl, propyl, n-butyl, i-butyl, t-butyl, 2-ethylhexyl, lauryl, phenyl, benzyl, 2-hydroxy of acrylic acid or methacrylic acid. Esterified compounds such as ethyl and 2-hydroxypropyl, ring-opening adducts of caprolactone of acrylic acid or 2-hydroxyethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide and N-methylol acrylamide, polyvalent Examples include (meth) acrylic acid esters of alcohol. Examples of the other ethylenically unsaturated monomers copolymerizable with these include styrene, α-methylstyrene, itaconic acid, maleic acid, and vinyl acetate.

  As said (b) polyester resin, saturated polyester resin and unsaturated polyester resin are mentioned, For example, the condensate obtained by heat-condensing a polybasic acid and a polyhydric alcohol is mentioned. Examples of polybasic acids include saturated polybasic acids and unsaturated polybasic acids. Examples of saturated polybasic acids include phthalic anhydride, terephthalic acid, and succinic acid. Examples of unsaturated polybasic acids include Examples thereof include maleic acid, maleic anhydride, and fumaric acid. Examples of the polyhydric alcohol include dihydric alcohol and trihydric alcohol. Examples of the dihydric alcohol include ethylene glycol and diethylene glycol. Examples of the trihydric alcohol include glycerin and trimethylolpropane. It is done.

The above (c) alkyd resin includes modifiers such as the above-mentioned polybasic acids and polyhydric alcohols, oils and fats and fatty acids (soybean oil, linseed oil, coconut oil, stearic acid, etc.), natural resins (rosin, amber, etc.) An alkyd resin obtained by reacting can be used.
The (d) fluororesin comprises any one of vinylidene fluoride resin, tetrafluoroethylene resin or a mixture thereof, a polymerizable compound containing a fluoroolefin and a hydroxy group, and other copolymerizable vinyl compounds. Examples thereof include resins made of various fluorine-based copolymers obtained by copolymerizing a monomer mixture.

  As said (e) epoxy resin, the resin etc. which are obtained by reaction of bisphenol and epichlorohydrin are mentioned. Examples of bisphenol include bisphenol A and F. Examples of the bisphenol-type epoxy resin include Epicoat 828, Epicoat 1001, Epicoat 1004, Epicoat 1007, and Epicoat 1009 (all trade names, manufactured by Shell Chemical Co., Ltd.), and these are used with an appropriate chain extender. A chain-extended one can also be used.

  Examples of the polyurethane resin (f) include resins having a urethane bond obtained by reaction of various polyol components such as acrylic, polyester, polyether, and polycarbonate with a polyisocyanate compound. Examples of the polyisocyanate compound include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), and a mixture thereof (TDI), diphenylmethane-4,4 ′. -Diisocyanate (4,4'-MDI), diphenylmethane-2,4'-diisocyanate (2,4'-MDI), and mixtures thereof (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3 ' -Dimethyl-4,4'-biphenylene diisocyanate, xylylene diisocyanate (XDI), dicyclohexylmethane diisocyanate (hydrogenated HDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), hydrogenated xylylene diisocyanate (HXDI) Etc. It is.

  The (g) polyether resin is a polymer or copolymer having an ether bond, such as a polyoxyethylene polyether, polyoxypropylene polyether, polyoxybutylene polyether, bisphenol A or bisphenol. Examples thereof include polyether resins having at least two hydroxyl groups per molecule, such as polyethers derived from aromatic polyhydroxy compounds such as F. In addition, the polyether resin is reacted with a polyvalent carboxylic acid such as succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, or a reactive derivative such as these acid anhydrides. And a carboxyl group-containing polyether resin obtained.

  When the vehicle includes a cross-linking agent, the ratio of the resin for forming a coating film to the cross-linking agent is preferably 90 to 50% by mass of the resin for forming a film and 10 to 50% by mass of the cross-linking agent in terms of solid content. The film-forming resin is 85 to 60% by mass, and the crosslinking agent is 15 to 40% by mass. If the crosslinking agent is less than 10% by mass, the coating film may not be sufficiently crosslinked. On the other hand, when the crosslinking agent exceeds 50% by mass, the storage stability of the coating composition is lowered and the curing rate is increased, so that the appearance of the coating film may be deteriorated.

  The mass ratio of the solid content in the vehicle to the solid content in the color base paint is preferably 30/100 to 90/100. When the solid content mass ratio of the solid content in the vehicle / the solid content in the color base paint is less than 30/100, sufficient weather resistance cannot be obtained, and it is a coating film with the color base paint film. Adhesiveness with a mica flake pigment-containing coating film may be reduced, and if it exceeds 90/100, the appearance of the coating film may be reduced. The mass ratio of the solid content in the vehicle to the solid content in the color base paint is more preferably 40/100 to 80/100.

  In addition to the above components, the color base paint includes a polyamide wax which is a lubricating dispersion of an aliphatic amide, a polyethylene wax which is a colloidal dispersion mainly composed of oxidized polyethylene, a curing catalyst, an ultraviolet absorber, an antioxidant, and leveling. An agent, a surface conditioner such as silicon or organic polymer, an anti-sagging agent, a thickener, an antifoaming agent, a lubricant, a crosslinkable polymer particle (microgel) and the like can be appropriately added. These additives can usually improve the performance of paints and coating films by blending at a ratio of 15 parts by mass or less with respect to 100 parts by mass (based on solid content) of the vehicle.

  The color base paint is provided in a form in which the constituent components are usually dissolved or dispersed in a solvent. Any solvent can be used as long as it dissolves or disperses the vehicle, and an organic solvent and / or water can be used. Examples of the organic solvent include those usually used in the paint field. Examples include hydrocarbons such as toluene and xylene, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, butyl acetate, cellosolve acetate, and butyl cellosolve, and alcohols. Water is preferably used when the use of organic solvents is restricted from an environmental point of view. In this case, an appropriate amount of a hydrophilic organic solvent may be contained.

  A method for forming the color base coating film on the substrate is not particularly limited, but a spray method, a roll coater method, and the like are preferable. The dry film thickness of the color base coating film coated with the above color base paint is preferably 10 to 100 μm, and by maintaining the dry film thickness within this range, a ceramic tone exhibiting a “ceramic tone with a sense of depth and light blue” A color-tone coating film can be obtained, and if it is less than 10 μm, it is difficult to conceal the base, and if it exceeds 100 μm, there is a risk of causing a poor appearance of the coating film, more preferably 20 to 50 μm.

[First step]
In the method for forming a ceramic-tone coating film of the present invention, this process is not performed in the A invention, but is a process performed in the B invention, which is a process of curing the color base coating film. The baking conditions for curing are preferably baking at 120 to 160 ° C. for 5 to 60 minutes.

[Second step]
In the ceramic-tone coating film forming method of the present invention, as a second step, the W / W method is applied to the color base coating film that is not cured in the A invention, and the W / W coating is applied to the cured color base coating film in the B invention. This is a step applied by the D method, and the white mica flake pigment (a) and the blue interference mica flake pigment (b) are (a) / (b) = 4/6 to 7/3 with respect to the color base coating film. A mica flake pigment-containing coating film containing (mass ratio) and (a) + (b) = 1 to 30 mass% (in the solid content of the coating film) is formed.

  For the formation of the mica flake pigment-containing coating, white mica flake pigment (a) and blue interference mica flake pigment (b) are used as follows: (a) / (b) = 4/6 to 7/3 (mass ratio) In addition, a mica flake pigment-containing paint containing (a) + (b) = 1 to 30% by mass (in the solid content of the coating film) is used.

  In the mica flake pigment-containing paint, the content ratio of the white mica flake pigment (a) and the blue interference mica flake pigment (b) is (a) / (b) = 4/6 to 7/3 (mass ratio). If it is out of this range, a “ceramic tone color tone with a deep feeling and a pale blue feeling” cannot be obtained, and a more preferable content ratio is (a) / (b) = 5/5 to 6/4 (mass ratio) ).

  In the mica flake pigment-containing paint, the total content (solid content) of the white mica flake pigment (a) and the blue interference mica flake pigment (b) together with the above ratio is (a) + (b) = 1 to 30% by mass (in the solid content of the coating film). When the total content is out of the above range, a “ceramic tone color tone with a feeling of depth and light blue” is not obtained, and a more preferable total content is (a) + (b) = 5 25% by mass (in the solid content of the coating film).

  The mica flake pigment contained in the mica flake pigment-containing paint is a pearl mica pigment having a coloring effect obtained by coating a surface of natural mica or synthetic mica with a thin film of metal oxide such as titanium dioxide. The diameter is preferably a small particle diameter, and the average particle diameter is 10 μm or less. When the average particle diameter exceeds 10 μm, there is a possibility that “a ceramic color tone with a feeling of depth and a pale blue color” may not be obtained. More preferable average particle diameters are 5 to 10 μm scaly particles. The color or interference color of the pearl mica pigment can be adjusted by changing the type and amount (coating thickness) of the metal oxide to be coated, but the white mica flake pigment (a) is natural mica. Titanium dioxide is obtained by coating with a thickness of 60 to 140 nm, and the blue interference mica flake pigment (b) is obtained by coating natural mica with titanium dioxide with a thickness of 140 to 350 nm.

Further, in the mica flake pigment-containing paint, the color pigment used in the color base paint can be used in the same manner for the color pigment that can be blended as necessary within the range not impairing the effects of the present invention.
Further, the vehicle used for the color base paint can be used in the same manner.

In the mica flake pigment-containing coating, in addition to the above components, additives used in the color base coating can be used in the same manner.
The mica flake pigment-containing paint is usually provided in a form in which the above-mentioned constituents are dissolved or dispersed in a solvent. As a solvent, the solvent used for the said color base coating material can be used similarly.

  A method for forming the mica flake pigment-containing coating film is not particularly limited, but a spray method, a roll coater method and the like are preferable. The dry film thickness of the mica flake pigment-containing coating film coated with the mica flake pigment-containing paint is preferably 5 to 50 μm. By maintaining the dry film thickness in this range, a “ceramic tone with a sense of depth and light blue” It is possible to obtain a ceramic toned coating film exhibiting “color tone”. If it is less than 5 μm, it is not possible to obtain a ceramic-tone coating film exhibiting a “tone-like color tone with a feeling of depth and light blue”, and if it exceeds 100 μm, the appearance of the coating film may be poor. ˜30 μm.

[Third step]
In the ceramic toning coating film forming method of the present invention, as a third step, the clear coating film is formed by applying a clear coating to the mica flake pigment-containing coating film by the W / W method. The clear coating film is formed by applying the clear paint by a well-known method such as a spray method or a roll coater method.
As the clear paint, those generally used as a clear top paint can be used, and for example, selected from acrylic resins, polyester resins, fluororesins, epoxy resins, polyurethane resins, polyether resins, and modified resins thereof. In addition, a mixture of at least one thermosetting resin and the above-described crosslinking agent can be used. A combination of a carboxyl group-containing polymer and an epoxy group-containing polymer described in JP-B-8-19315 is preferably used from the viewpoint of acid rain resistance.
The clear paint can take various forms such as a solvent type, a water-based type, and a powder type. As the solvent-based paint or water-based paint, a one-component paint may be used, or a two-component resin such as a two-component urethane resin paint may be used.
Moreover, additives such as a modifier, an ultraviolet absorber, a leveling agent, a dispersant, and an antifoaming agent can be blended with the clear coating as necessary.
In addition, it is preferable that the dry film thickness of the said clear coating film is 20-50 micrometers, and when it remove | deviates from this range, there exists a possibility of producing the coating-film external appearance defect, More preferably, it is 25-45 micrometers.

[Fourth step]
In the method for forming a ceramic toning coating film of the present invention, as the fourth step in the invention A, the step of simultaneously curing the color base coating film, the mica flake pigment-containing coating film and the clear coating film has a “feeling of depth”. It is possible to obtain a coating film exhibiting a “ceramic tone color with a light blue sensation”. The baking conditions for curing are preferably baking at 120 to 160 ° C. for 5 to 60 minutes.

[Step 4 ']
In the method for forming a ceramic toned coating film of the present invention, as the fourth step in the B invention, by the step of simultaneously curing the mica flake pigment-containing coating film and the clear coating film, “there is a feeling of depth and light blueness” A coating film exhibiting a “ceramic tone” can be obtained. The baking conditions for curing are preferably baking at 120 to 160 ° C. for 5 to 60 minutes.

<Painted object>
The coated product of the present invention is a product coated with a 3-coat 1-bake coating system (Invention A) or a 3-coat 2-bake coating system (Invention B) by the above-described method of forming a ceramic toning film, (I) In the color gamut in the L ^* a ^* b ^* display system of the dried coating film to be formed, the L ^* value is 60 to 100, the a ^* value is +1.5 to −1.5, and the b ^* value is − 1 to −20 color base coating film; (II) white mica flake pigment (a) and blue interference mica flake pigment (b), (a) / (b) = 4/6 to 7/3 (mass ratio) ) And (a) + (b) = 1 to 30% by mass (in the solid content of the coating film), the mica flake pigment-containing coating film is formed in this order.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited only to these Examples. In addition, unless otherwise indicated, a compounding quantity represents a mass part. The names of raw materials, paints, and equipment represent product names unless otherwise specified.

Examples 1-15, Comparative Examples 1-12
Preparation of base material Dal steel plate (length 300 mm, width 100 mm and thickness 0.8 mm) was subjected to chemical conversion treatment using a zinc phosphate treating agent ("Surfdyne SD2000", manufactured by Nippon Paint Co., Ltd.), followed by cationic electrodeposition coating (“Power Top U-50”, manufactured by Nippon Paint Co., Ltd.) was electrodeposited so that the dry film thickness was 25 μm. Subsequently, it baked for 30 minutes at 160 degreeC, and was set as the base material.

Preparation of color base paint Based on white polyester / melamine resin base color base paint, black, blue, yellow, red, green base color base, and 11 kinds of dry paint color gamuts as shown below. A color base paint was prepared.
(Hereinafter, for examples)
L ^* : 85 a ^* : +1 b ^* : −5
L ^* : 65 a ^* : +1 b ^* : −5
L ^* : 90 a ^* : +1 b ^* : −5
L ^* : 85 a ^* : -1 b ^* : -5
L ^* : 85 a ^* : +1 b ^* : -2
L ^* : 85 a ^* : +1 b ^* : −15
(Hereafter, for comparative examples)
L ^* : 50 a ^* : +1 b ^* : −5
L ^* : 85 a ^* : +5 b ^* : −5
L ^* : 85 a ^* : -5 b ^* : -5
L ^* : 85 a ^* : +1 b ^* : +5
L ^* : 85 a ^* : +1 b ^* : +25

Preparation of paint containing mica flake pigment Acrylic resin (styrene / methyl methacrylate / ethyl methacrylate / hydroxyethyl methacrylate / methacrylic acid copolymer, number average molecular weight about 20,000, hydroxyl value 45, acid value 15, solid content 50% by mass) Table 1 shows pigments of the following types with respect to a vehicle obtained by blending a melamine resin (“Uban 20SE”, manufactured by Mitsui Chemicals, Inc., solid content 60 mass%) at a solid mass ratio of 80:20. It mix | blended with the quantity (PWC). Next, the mixture was mixed with an organic solvent (toluene / xylene / ethyl acetate / butyl acetate mass ratio = 70/15/10/5) with a stirrer so as to obtain an appropriate coating viscosity, thereby preparing a mica flake pigment-containing coating.

Mica flake pigment (a-1): White mica flake pigment (average particle size 5.4 μm; “EXTERIOR CFS MEARLIN MAGNAPEARL 3103”, manufactured by ENGELHARD)
Mica flake pigment (a-2): White mica flake pigment (average particle diameter 18 μm; “EXTERIOR CFS MEARLIN MAGNAPEARL 1103”, manufactured by ENGEqLHARD)
Mica flake pigment (b-1): Blue interference mica flake pigment (average particle 7.9 μm; “EXTERIOR CFS MEARLIN MICRO BLUE”, manufactured by ENGELHARD)
Mica flake pigment (b-2): Blue interference mica flake pigment (average particle 22 μm; “EXTERIOR CFS MEARLIN LUMINA AQUA-BLUE”, manufactured by ENGELHARD)
Mica flake pigment (c): Green interference mica flake pigment (average particle size 7.7 μm; “EXTERIOR CFS MEARLIN MICRO GREEN” manufactured by ENGELHARD Co., Ltd.)
Colored pigment (P): Phthalocyanine blue pigment (“Cyanine Blue G314”, manufactured by Sanyo Kasei Co., Ltd.)

Preparation of Clear Paint The clear paint used was an acrylic / melamine resin-based clear paint 1 ("Superlac O-130 Clear", manufactured by Nippon Paint Co., Ltd.) or a clear paint containing a carboxyl group-containing polymer and an epoxy group-containing polymer. 2 (“Mac Flow O-520 Clear”, manufactured by Nippon Paint Co., Ltd.). Each was stirred and mixed with a viscosity adjusting solvent so as to obtain an appropriate coating viscosity with a stirrer, and prepared as a first clear paint and a second clear paint.

Formation of Ceramic Toning Coating Film Each polyester / melamine resin color base paint prepared above in the color gamut shown in Table 2 on the coated surface of the base material in the combination shown in Table 2 has a dry film thickness of 40 μm. In the A invention, it is set for 3 minutes after painting, or in the B invention, it is baked at a temperature of 140 ° C. for 30 minutes to form a color base coating film, and then the mica flake pigment-containing paint obtained above is dried. The coating was performed so that the thickness was 15 μm. The mica flake pigment-containing paint was applied at an atomizing pressure of 2.8 kg / cm ² using an electrostatic coating machine (“Auto REA”, manufactured by ABB Industry). After the coating, setting was performed for 3 minutes, and a clear coating of the type shown in Table 2 was applied so that the dry film thickness was 35 μm, setting was performed at room temperature for 10 minutes, and baking was performed at a temperature of 140 ° C. for 30 minutes.
The obtained coating film was used as a test plate to evaluate the design properties. The results are shown in Table 2.

Evaluation Method Designability: The test plate was visually evaluated.
3 ... Remarkably recognized as "ceramic tone with depth and pale blue" 2 ... 1 recognized as "certain tone with depth and pale blue" 1 ... "Ceramic tone with depth and pale blue" Is not allowed

  As is apparent from the results in Table 2, this example is a ceramic toning coating film formed by the ceramic toning coating film forming method of the present invention. A design that exhibits a "ceramic tone with a light blue sensation" was developed. On the other hand, the comparative example could not exhibit a “ceramic tone having a sense of depth and light blue”.

Claims (4)

Ceramic toning coating film forming method for sequentially performing the following steps (1) to (4):
(1) L ^* value is 60 to 100, a ^* value is +1.5 to -1.5 and b in the color gamut of the dry coating film formed in the L ^* a ^* b ^* display system with respect to the substrate. ^* Step of forming a color base coating film having a value of -1 to -20;
(2) For the color base coating film, white mica flake pigment (a) and blue interference mica flake pigment (b) are (a) / (b) = 4/6 to 7/3 (mass ratio) and A step of forming a mica flake pigment-containing coating film containing (a) + (b) = 1-30 mass% (in the solid content of the coating film);
(3) A step of forming a clear coating film on the mica flake pigment-containing coating film;
(4) A step of curing the color base coating film, the mica flake pigment-containing coating film, and the clear coating film. Ceramic toning coating film forming method for sequentially performing the following steps (1) to (4 ′):
(1) L ^* value is 60 to 100, a ^* value is +1.5 to -1.5 and b in the color gamut of the dry coating film formed in the L ^* a ^* b ^* display system with respect to the substrate. ^* Step of forming a color base coating film having a value of -1 to -20;
(1 ′) Step of curing the color base coating film (2) For the color base coating film, white mica flake pigment (a) and blue interference mica flake pigment (b) are (a) / (b) = A step of forming a mica flake pigment-containing coating film containing 4/6 to 7/3 (mass ratio) and (a) + (b) = 1 to 30 mass% (in the solid content of the coating film);
(3) A step of forming a clear coating film on the mica flake pigment-containing coating film;
(4 ′) A step of curing the mica flake pigment-containing coating and the clear coating. In the color gamut in the L ^* a ^* b ^* display system of the dried coating film on which the color base coating film is formed, the L ^* value is 70 to 100, the a ^* value is +1.5 to −1.5, and the b ^* value. It is -1 to -6, The method for forming a ceramic toning film according to claim 1 or 2. A ceramic toning coating product coated by the method for forming a ceramic toning coating film according to any one of claims 1 to 3.