JP2005334717A - Method for forming multi-layer coating film, film structure and coated article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare a blue multi-layer coating film having an excellent color feeling, or a feeling of blue with high saturation and excellent depth and transparency in the shade, to various industrial products, e.g. car body skins. <P>SOLUTION: The subject method comprises coating a base-coat coating material (A) onto a base material to form a film, coating a metallic base coating material (B) containing a bright pigment and showing a light transmission as film in the visible-light region of ≥40% onto the film of (A) and coating a top clear coating material (C) onto the film of (B), and the base-coat coating material (A) and/or the metallic base coating material (B) contains the ultramarine blue pigment. A film structure and a coated article are also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method, a coating film structure, and a coated article that can form a metallic coating film that is blue and excellent in color retention and depth of shade.

As a design for automobiles and industrial products, there is a demand for a metallic coating color that is blue and excellent in color retention. Blue-based metallic paint color with excellent color accumulation is a highlight (observation of the coating film in the vicinity of specular reflection light) with a strong brightness and a white color with almost no color, shade (regular reflection) (Observed at an angle not affected by light) refers to a coating color that exhibits a high blue saturation and has little turbidity or color flop (color change to red or yellow) and excellent depth and transparency.

    As a method of obtaining a metallic coating film that is blue and excellent in depth and transparency, a base paint containing scaly glittering pigment and blue pigment is applied, and a clear paint is applied on the obtained coating film. Then, the so-called 2C1B process for simultaneously curing them, a color base paint containing a color pigment such as a blue pigment, and the like, and a metallic base paint containing a scaly glittering pigment on the obtained coating film are applied. Further, a so-called 3C1B process in which a clear paint is applied onto the obtained coating film and these are simultaneously cured is already known. For example, in Patent Document 1, as a method for obtaining an excellent appearance with high saturation, a color base paint, an inorganic fired pigment, and a glitter pigment-containing base paint containing a scaly glitter pigment and a clear paint are sequentially applied. A method for forming a pearl coating consisting of: However, the inorganic fired pigment may have insufficient coloring power.

    Patent Document 2 discloses that as a blue pigment composition having sharpness, color development, and depth, cobalt phthalocyanine and / or low chlorinated cobalt phthalocyanine and copper phthalocyanine and / or low chlorinated copper phthalocyanine are simultaneously pigmented. Pigment compositions and coating compositions using the same are described. However, when a phthalocyanine pigment is used as a coloring pigment, the shade may become muddy red and dichroism may occur.

    A blue-based metallic coating can be formed by applying a base paint containing a blue coloring pigment and a luster pigment, and then applying a top clear coating on the resulting coating. Even when a clear and transparent ultramarine pigment is used as the color pigment, the depth is not sufficient.

JP 2003-236462 A JP-A-10-231439

An object of the present invention is to provide a method for forming a multi-layer coating film and a coated article which are blue-based and have a deep feeling and a shaded color retention feeling.

The present invention
1. A metallic base paint (B) containing a bright pigment on the coating film obtained by coating the base coat paint (A) on the substrate and having a light transmittance of 40% or more in the visible light region of the coating film. ), And a top clear coating (C) is coated on the obtained coating film, which is a method for forming a multilayer coating film, wherein the base coat coating (A) and / or the metallic base coating (B) is an ultramarine pigment. A method for forming a multilayer coating film, comprising:
2. 2. The method for producing a multilayer coating film according to 1, wherein the ultramarine pigment is coated with one or more metal oxides selected from silicon, aluminum, zirconium and titanium.
3. The method for forming a multilayer coating film according to item 1 or 2, wherein the L value, which is the brightness of the obtained multilayer coating film, is 30 or more
Obtained by the coating film structure obtained by the multilayer coating film forming method according to any one of 4.1 to 3 and the multilayer coating film forming method according to any one of 5.1 to 3 Painted articles,
About.

According to the method of the present invention, a metallic base paint containing a glittering pigment is applied onto a coating film obtained by applying a base coat paint onto a substrate, and a top clear coating is further applied onto the obtained coating film. A multi-layer coating film that paints, and by blending a specific ultramarine pigment into the base coat paint and / or metallic base paint, a multi-layer coating film that is blue and excellent in shades and depth of shade. Can be obtained.

In the method of the present invention, the base material is a metal such as iron, zinc or aluminum, an alloy of these metals, a molded product plated or vapor-deposited with these metals, and a molded product made of glass, plastic or foam. Materials such as things can be mentioned. A treated material obtained by subjecting these materials to a degreasing treatment or a surface treatment can also be used as a base material. Furthermore, a coating film forming material in which an undercoat coating film or an intermediate coating film is formed on the substrate can be used as the substrate, and the coating film forming material is particularly preferable.

    The undercoat coating film is formed to conceal the surface of the material or impart corrosion resistance and rust resistance to the material, and can be obtained by coating and curing the undercoat paint. The type of the undercoat paint is not particularly limited, and examples thereof include an electrodeposition paint and a solvent-type primer.

    The intermediate coating film is formed to conceal the surface of the material or the undercoating film, or to impart adhesion or chipping resistance. It can be obtained by applying and curing a paint. The type of the intermediate coating is not particularly limited, and known ones can be used. For example, an organic solvent-based or water-based intermediate coating containing a thermosetting resin composition and a color pigment can be preferably used.

    In the method of the present invention, in the case of using a base coating film and / or an intermediate coating film formed as a base material, the base coating film and / or the intermediate coating film is heated and described later after crosslinking and curing. Although the paint of the next step can be applied, the paint of the next step can also be applied in a state where the undercoat and / or intermediate coat is uncured. Include.

    In the method of the present invention, the base coat paint (A) is applied on the substrate as described above. The base coat paint (A) is a paint for determining a hue in a multilayer coating film, particularly a hue in a shade portion, and can contain a ultramarine pigment.

The ultramarine pigment is one of the synthetic colored pigments and is represented by the general formula [Na _x Al _x Si _(12-x) O ₂₄ · Na _y S _z ]. As the ultramarine pigment, conventionally known pigments can be used for paints, inks, plastics, or painting materials. From the viewpoint of weather resistance and acid resistance of the coating film, silicon, aluminum, zirconium Those coated with one or more metal oxides selected from titanium can be particularly preferably used. The average primary particle diameter of the ultramarine pigment is preferably 0.3 to 6 μm, more preferably 0.5 to 3 μm from the viewpoint of coloring power and transparency.

    In the method of the present invention, when the ultramarine pigment is added to the base coat paint (A), the content thereof is 50 parts by weight or less, preferably 0. 0 parts by weight based on 100 parts by weight of the resin solid content in the paint composition. It is 5-35 weight part, More preferably, it is 1-25 weight part.

    The base coat paint (A) in the method of the present invention can contain other color pigments in addition to the above-mentioned ultramarine pigment. As the other colored pigments, conventionally known pigments for ink and paint can be used singly or in combination of two or more. Specific examples of the color pigment include metal oxide pigments such as titanium oxide and iron oxide, composite metal oxide pigments such as titanium yellow, carbon black, azo pigments, quinacridone pigments, diketopyrrolopyrrole pigments, and perylene pigments. Pigments, perinone pigments, benzimidazolone pigments, isoindoline pigments, isoindolinone pigments, metal chelate azo pigments, phthalocyanine pigments, indanthrone pigments, dioxane pigments, indigo pigments, etc. it can.

    When using the above-mentioned color pigment, the blending amount thereof is 50 parts by weight or less with respect to 100 parts by weight of the resin solid content in the base coat paint (A) from the viewpoint of coloring power and finished appearance of the obtained coating film. Is preferred, with 1 to 30 parts by weight being particularly preferred.

    In the method of the present invention, the base coat paint (A) can contain a bright pigment in addition to the ultramarine pigment and the colored pigment. Examples of the luster pigment include flaky metal pigments such as aluminum, copper, nickel alloy, and stainless steel, flaky metal pigments whose surfaces are coated with metal oxides, and flaky metal pigments that have a color pigment chemically adsorbed on the surface. , Scaly aluminum pigments that have formed an aluminum oxide layer by causing a redox reaction on the surface, aluminum solid-plated iron oxide pigments, glass flake pigments, glass flake pigments coated with metal oxides on the surface, colored on the surface Glass flake pigment with chemically adsorbed pigment, interference mica pigment coated with titanium dioxide on the surface, reduced mica pigment with reduced interference mica pigment, colored mica with colored pigment chemisorbed on the surface or coated with iron oxide Pigment, graphite pigment coated with titanium dioxide on the surface, silica flake coated with titanium dioxide on the surface, Lumina flake pigments, plate-like iron oxide pigments, holographic pigments, synthetic mica pigments, cholesteric liquid crystal polymer pigments having a helical structure, and the like oxy bismuth pigments chloride. Of these, scaly metal pigments and mica pigments are preferred, and particularly preferred are aluminum flake pigments and interference mica pigments whose surfaces are coated with titanium oxide. May be used as appropriate.

    When the above-mentioned glitter pigment is used, the blending amount thereof is preferably 50 parts by weight or less, more preferably 1 part from the point of glitter of the coating film with respect to 100 parts by weight of the resin solid content in the base coat paint (A). -30 parts by weight.

    As the resin component used in the base coat paint (A) of the present invention, a thermosetting resin composition is preferable. Specifically, for example, an acrylic resin, a polyester resin, or an alkyd having a crosslinkable functional group such as a hydroxyl group. Examples include those in which a base resin such as resin or urethane resin and a crosslinking agent such as melamine resin, urea resin, or polyisocyanate compound (including a block body) are used in combination, such as an organic solvent and / or a solvent such as water. It can be used by dissolving or dispersing.

    Further, for the base coat paint (A), if necessary, a solvent such as water or an organic solvent, a rheology control agent, a pigment dispersant, an anti-settling agent, a curing catalyst, an antifoaming agent, an antioxidant, an ultraviolet absorber, etc. These various additives, extender pigments and the like can be appropriately blended.

    The base coat paint (A) in the method of the present invention can be prepared by mixing and dispersing the aforementioned components.

    The base coat paint (A) in the method of the present invention can be applied by a method such as electrostatic spray coating, air spray, airless spray, and the film thickness is in the range of 0.5 to 30 μm based on the cured coating film. It is preferable from the point of the smoothness of a coating film, More preferably, it is 5-25 micrometers. In the case of spray coating, the base coat paint (A) usually has a solid content of 15 to 50% by weight, preferably 20 to 40% by weight, and a viscosity at 20 ° C. of 11 to 15 seconds / during coating. It is preferable to adjust so that it becomes Ford cup # 4. The coating film itself of the base coat paint (A) can be crosslinked and cured usually at a temperature of about 70 to about 150 ° C.

    In the method of the present invention, the metallic base paint (B) can be further applied to the uncured or cured coating surface of the base coat paint (A).

    The metallic base paint (B) in the method of the present invention is a paint for determining the glitter feeling in the multilayer coating film, which comprises a glitter pigment as an essential component, and a resin component and a solvent such as water or an organic solvent as main components. Furthermore, it is a liquid paint obtained by blending ultramarine pigments, color pigments and other paint additives as required, and is a colorless or colored transparent coating film having an excellent glitter feeling due to the glitter pigment. To form.

    The coating film made of the metallic base paint (B) in the method of the present invention is a spectrophotometer obtained by peeling off a coating obtained by drying and curing after coating on a smooth PTFE plate so as to have a film thickness of 25 μm. The light transmittance in the visible light region (wavelength 400 nm to 700 nm) measured with “MPS-2450” (trade name: manufactured by Shimadzu Corporation) is preferably 40% or more, and more preferably 50% or more. The light transmittance in the visible light region is a ratio of transmitting visible light rays, and means that the larger the numerical value, the higher the transparency.

    As the bright pigment blended in the metallic base paint (B) in the method of the present invention, the same bright pigments that can be used in the base coat paint (A) can be appropriately used.

    A preferable blending amount of the glitter pigment is 0.1 to 20 parts by weight with respect to 100 parts by weight of the vehicle solid content in the metallic base paint (B). If it is less than 0.1 part by weight, the glitter in the shade part is insufficient, and if it exceeds 20 parts by weight, the appearance of the coating film may be deteriorated. More preferably, it is 0.5 to 10 parts by weight.

    In the method of the present invention, an ultramarine pigment can be blended in the base coat paint (A) and / or the metallic base paint (B). When the ultramarine pigment is blended in the metallic base paint (B), the amount added may be determined as appropriate, but is preferably 30 parts by weight or less, preferably 100 parts by weight or less of the vehicle solid content in the metallic base paint (B). Is suitably in the range of 0.1 to 10 parts by weight. As the ultramarine pigment blended in the metallic base paint (B), the same pigments as those usable in the base coat paint (A) described above can be used.

    In the metallic base coating material (B) in the method of the present invention, a coloring pigment can be appropriately blended in addition to the above-described ultramarine pigment within a range that does not impair the transparency. The coloring pigment is not limited, and one or two or more conventionally known pigments can be used in combination for inks and paints. The amount of addition may be determined as appropriate, but it is 30 parts by weight or less, preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the vehicle solid content in the metallic base paint (B). .

    The metallic base paint (B) in the method of the present invention may contain a resin component as a vehicle in addition to the glitter pigment and the color pigment. As the resin component, the same resin as that which can be used in the base coat paint (A) can be used.

    Furthermore, various additives such as a solvent such as water or an organic solvent, a pigment dispersant, an antisettling agent, a curing catalyst, an antifoaming agent, an antioxidant, and an ultraviolet absorber are added to the metallic base paint (B) as necessary. An agent, extender, etc. can be appropriately blended.

    The metallic base paint (B) can be prepared by mixing and dispersing the aforementioned components. Usually, at the time of coating, the solid content is 30 to 60% by weight, preferably 35 to 50% by weight, based on the coating composition, and the viscosity at 20 ° C. is 20 to 25 seconds / Ford cup # 4. It is preferable to make adjustments.

    The metallic base paint (B) can be applied by a method such as electrostatic coating, air spray, airless spray, etc. The film thickness is a cured coating film from the viewpoint of the smoothness and glitter of the coating film. Is preferably in the range of 5 to 40 μm. The coating of the metallic base paint (B) itself can be crosslinked and cured at a temperature of about 70 to about 150 ° C.

    In the method of the present invention, the top clear paint (C) can be applied on the coating film on which the metallic base paint (B) has been applied and cured, but the metallic base paint (B) is not cured without being cured by heating. The top clear paint (C) can be applied on the coating film in the state.

    The top clear paint (C) in the method of the present invention is a colorless or colored transparent coating film comprising a resin component as a main component and further containing a paint additive, a solvent such as water or an organic solvent, if necessary. It is a liquid or powder paint to be formed.

    A conventionally well-known thing can be used for a top clear coating material (C) in the method of this invention without a restriction | limiting. For example, a liquid or powdery coating composition containing a base resin and a crosslinking agent can be applied. Examples of the base resin include acrylic resin, polyester resin, alkyd resin, fluororesin, urethane resin, and silicon-containing resin containing a crosslinkable functional group such as a hydroxyl group, a carboxyl group, a silanol group, and an epoxy group. . As a crosslinking agent, a melamine resin, urea resin, polyisocyanate compound, block polyisocyanate compound, epoxy compound or resin, carboxyl group-containing compound or resin, acid anhydride, alkoxysilyl group-containing, which can react with the functional group of the base resin Examples thereof include compounds or resins. Further, if necessary, additives such as a solvent such as water and an organic solvent, a curing catalyst, an antifoaming agent, an ultraviolet absorber, a rheology control agent, and an anti-settling agent can be appropriately blended.

    In the top clear paint (C) in the method of the present invention, a color pigment can be appropriately blended within a range not impairing transparency. As the color pigment, one or a combination of two or more conventionally known pigments for ink and paint can be blended. The amount of addition can be appropriately determined, but is preferably 30 parts by weight or less, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin solid content in the top clear paint (C). .

    The top clear paint (C) in the method of the present invention is prepared by mixing and dispersing the aforementioned components.

    The top clear coating (C) in the method of the present invention can be applied by a method such as electrostatic coating, air spraying, airless spraying, and the film thickness is based on the cured coating film from the viewpoint of the smoothness of the coating film. The thickness is preferably in the range of 15 to 50 μm, and more preferably in the range of 25 to 40 μm. When the top clear paint (C) is in a liquid state and is spray-coated, the solid content is usually 30 to 60% by weight, preferably 40 to 50% by weight, based on the coating composition. Moreover, it is preferable to adjust the viscosity at 20 ° C. to 18 to 25 seconds / Ford Cup # 4. The coating film of the top clear paint (C) itself can be usually cured at a temperature of about 70 to about 150 ° C.

    The multi-layer coating film obtained by the method of the present invention preferably has a lightness L value of 30 or more, more preferably 45 or more. Specifically, the L value here is obtained by applying the multilayer coating film obtained by the method of the present invention to various colorimeters such as “SM color computer” (colorimeter, trade name, manufactured by Suga Test Instruments Co., Ltd.). Can be obtained by measuring colors.

Next, an Example is given and this invention is demonstrated more concretely. In the examples, a ultramarine pigment (Ultramarine Blue 17, trade name, manufactured by HOLLIDAY PIGMENTS, average particle size of 2.2 μm) whose surface is coated with silica was used.

Examples and Comparative Examples (1) Preparation of Substrate Cationic electrodeposition paint “Electron 9400HB” (trade name: Kansai Paint Co., Ltd.) on a steel plate (JISG 3141, size 400 × 300 × 0.8 mm) subjected to degreasing and zinc phosphate treatment Made of epoxy resin polyamine-based cationic resin using block polyisocyanate compound as curing agent) based on the cured coating film, electrodeposited to a film thickness of 20 μm, and heated at 170 ° C. for 20 minutes for crosslinking and curing To obtain an electrodeposition coating film.

On the obtained electrodeposited surface, an intermediate coating “Lugabake Intermediate Gray” (trade name: manufactured by Kansai Paint Co., Ltd., polyester resin / melamine resin type, organic solvent type) is applied to the film based on the cured coating film by air spray. The film was coated to a thickness of 30 μm, heated at 140 ° C. for 30 minutes to be crosslinked and cured to form an intermediate coating film, and the obtained intermediate coating plate was used as a substrate.
Preparation of paint Blending the luster and, if necessary, the color pigment in the ratio shown in Table 1 per 100 parts by weight (solid content) of a resin component comprising a hydroxyl group-containing acrylic resin (hydroxyl value 100, number average molecular weight 20000) and melamine resin Then, the mixture was agitated and mixed, diluted to an appropriate viscosity for coating, and an organic solvent-type paint having a solid content of about 25% was prepared to prepare a base coat paint and a metallic base paint.

(3) Preparation of test plate A test plate was prepared by applying the base coat paint, metallic base paint prepared in (2), and top clear paint (not shown in the table) in the following procedure.

(Base coat paint application)
The base coat paint prepared in (2) was applied to the intermediate coating plate prepared in (1) using a mini-bell type rotary electrostatic coating machine at a booth temperature of 20 ° C. and a humidity of 75%. It was painted so that the film thickness was.

(Painting of metallic base paint)
After the base coat paint is applied, it is allowed to stand at room temperature for 15 minutes, and then the metallic base paint prepared in (2) is applied to these uncured coating surfaces using a minibell-type rotary electrostatic coating machine, with a booth temperature of 20 ° C., The cured coating film was applied at a humidity of 75% so as to be about 30 μm.

(Coating of top clear paint)
After painting the metallic base paint, let it stand at room temperature for 15 minutes, and then top clear paint on these uncured paint surfaces (Luga Bake Clear, manufactured by Kansai Paint, trade name, acrylic resin / amino resin type, organic solvent type) Was coated using a mini-bell type rotary electrostatic coating machine so as to be about 30 μm as a cured coating film under the conditions of a booth temperature of 20 ° C. and a humidity of 75%. After coating, it was allowed to stand at room temperature for 15 minutes and then heated at 140 ° C. for 30 minutes in a hot-air circulating drying oven to simultaneously dry and cure the multilayer coating film to obtain a test plate.

Evaluation Test About the obtained test plate, the color retention in the shade portion was visually evaluated. Table 3 shows the results.

The coating film forming method of the present invention can be applied to various industrial products, particularly to the outer plate of an automobile body.

Claims (5)

A metallic base paint (B) containing a bright pigment on the coating film obtained by coating the base coat paint (A) on the substrate and having a light transmittance of 40% or more in the visible light region of the coating film. ), And a top clear coating (C) is coated on the obtained coating film, which is a method for forming a multilayer coating film, wherein the base coat coating (A) and / or the metallic base coating (B) is an ultramarine pigment. A method for forming a multilayer coating film, comprising: 2. The method for producing a multilayer coating film according to claim 1, wherein the ultramarine pigment is coated with one or more metal oxides selected from silicon, aluminum, zirconium and titanium. The lightness L value of the obtained multilayer coating film is 30 or more, The multilayer coating film formation method of Claim 1 or 2. The coating-film structure obtained by the multilayer coating-film formation method of any one of Claims 1-3. The coated article obtained by the multilayer coating-film formation method of any one of Claims 1-3.