JPH1034072A - Decorative coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly decorative coating finished surface having strong flip-flop feeling and excellent coloring property (depth of color, high clean tone). SOLUTION: In the coating for a base body 1 of an automotive body, etc., a decorative coating material composition consisting of a combined system of a granular transparent iron oxide pigment consisting of manganese-containing hematite shown by a general formula: α-Fe2- XMnx O3 (x=0.1-0.7) and a coherence mica pigment and/or a pearl mica pigment as pigment components is applied on a primary (including intercoating) coating film layer 2 to form a colored base coating film layer 3 and form a clear coating film layer 4. By the mutual action of the transparent iron oxide pigment contained in the colored base coating film layer 3 and the mica pigment 6, a high decorative effect is obtained. Also, since the covering property of the colored base coating film layer 3 is high, these top coating films 3, 4 can be formed by a two-coating and one baking coating method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of painting a design of an automobile body and the like, and more particularly, to a method of painting a design capable of exhibiting excellent design properties such as a strong flip-flop feeling, and a design using the same. The present invention relates to a paint film structure and a paint composition for design coating used therefor.

[0002]

2. Description of the Related Art In general, coating of an automobile body is carried out by applying an undercoating mainly by electrodeposition coating for preventing corrosion of a substrate, and then applying an intermediate coating for improving smoothness of a coated surface or ensuring chipping resistance. Then, a top coat is applied as a finish coat. Here, a top coat that forms a decorative coating film and gives a beautiful appearance to a vehicle body is particularly important in increasing the commercial value of an automobile.

[0003] Conventionally, as a top coat of the vehicle body, a solid color paint that develops various colors with a color pigment (opaque solid pigment) and a metallic pigment such as aluminum flake or the like are combined by using a metallic pigment such as aluminum flake. There is a metallic color painting that gives a glossy feeling. In recent years, as a design coating corresponding to diversification and individualization of needs, there are a colored mica coating which is a color coating using a mica pigment, a pearl mica coating having a unique pearl luster, and an interference mica coating.

[0004] Here, according to the metallic coating, light incident on the coating film is reflected by aluminum flakes in the coating film and shines, whereby a unique metallic feeling and a brilliant feeling can be obtained. In this metallic coating, when the observation angle is gradually inclined from the direction perpendicular to the coating surface, the brightness decreases and the chromaticity changes. The shades and shades of color that occur on the painted surface due to the appearance of different colors depending on the viewing angle in this way are called "flip-flop feeling", which effectively provides a smooth three-dimensional effect according to the curved shape of the car body Can be expressed. In addition, such a metallic coating is generally applied to a metallic base paint containing a metallic pigment such as aluminum flake and a coloring pigment, and further to a clear paint for improving the surface gloss and protecting from contamination by a chemical substance or the like. 2 coats that are painted and bake-hardened together
It is performed with bake specification.

[0005] Such a flip-flop feeling can be obtained to some extent by pearl mica coating, interference mica coating, and colored mica coating using mica pigments.

[0006] The pearl mica coating uses a transparent pearl mica pigment in which the surface of mica (mica) is thinly coated with titanium dioxide, and the incident light interferes with multiple reflections on the surface to produce milky pearls. Gives gloss. And
Specifically, this pearl mica coating is performed by applying a coating composition containing a pearl mica pigment on the surface of a color base (solid color base) coating layer of a color base coating containing a normal coloring pigment. And further forming a clear coating layer of a clear paint on the surface. In other words, this pearl mica coating as a top coat is formed with a three-layer coating structure, and the color is determined by the reflected light of the color pigment of the color base coating layer and the interference reflected light of the pearl mica pigment of the pearl mica coating layer. Be composed. The coating specification is generally a three-coat two-bake method including a baking step of a color base coating layer.

On the other hand, interference mica coating uses an interference mica pigment as a pigment component. This interference mica pigment, like the pearl mica pigment, is a thin layer of titanium dioxide coated on mica.In this case, the titanium dioxide layer is thicker, and the reflected light interferes with the thickness of the mica to give a color. Presents an interference color. In the interference mica coating, the interference mica pigment is transparent, that is, light-transmitting, and has a low hiding power. Therefore, similarly to the pearl mica coating, a color base coating layer containing a coloring pigment, an interference mica including the interference mica It is generally formed in a three-layer coating structure of a base coating layer and a clear coating layer. Therefore, the coating specification is generally a three-coat two-bake system. The interference mica pigment may be used for metallic coating in combination with aluminum flake.

[0008] The colored mica coating uses a colored mica pigment in which titanium dioxide coating mica is further coated with iron oxide. Specifically, since this colored mica pigment has a low transparency and a relatively strong hiding power, the colored mica coating is, like the metallic coating, a colored mica-based coating layer containing the same together with a normal coloring pigment and a clear coating. And a two-layer coating structure. Therefore, the coating specification is a two-coat one-bake method.

[0009]

As described above, according to the coating method using mica pigments such as pearl mica pigment, interference mica pigment and colored mica pigment, unlike the metallic coating, the surface of the mica pigment is different from the metallic coating. By the interference light generated by the multiple reflection of the above, it is possible to obtain a design finish surface with a unique glitter. Also, with that,
A flop feeling can also be obtained.

However, the stronger the flip-flop feeling, the better in terms of design. However, in the case of pearl mica coating using transparent pearl mica pigment and interference mica pigment and interference mica coating, However, depending on the hue and lightness conditions of the color base coating layer containing the color pigment, a sufficiently strong flip-flop feeling may not always be obtained, and in the case of the color mica coating using the color mica pigment, Even when it was adjusted, there was a tendency that a little flip-flop feeling was obtained. In addition, colored mica coating can be performed by a simple coating process using a two-coat one-bake method. However, in the case of pearl mica coating and interference mica coating, a color base coating layer is formed to form a color base coating layer. This further required a coating step including a baking step of the coating composition.

Incidentally, iron oxide pigments are known as coloring pigments.

Iron oxide pigments are the most typical general-purpose coloring pigments. Hematite (α-Fe ₂ O ₃ ) is a reddish brown pigment (Vengara), maghematite (γ-Fe ₂ O ₃ ) is a brown pigment, and magnetite (FeO _x · Fe ₂ O
₃ , x = 0-1) are widely used as black pigments. And, as these iron oxide pigments, there are those having various shapes such as needle shape, granular shape, plate shape, spindle shape,
In addition, various sizes are obtained.

In addition to these, a transparent iron oxide pigment made of manganese-containing hematite in which manganese is dissolved in red iron oxide has been developed. This transparent iron oxide pigment is synthesized by a wet method, has a fine granular shape (isotropic shape), and has a black yellow color (oak color) due to containing manganese.

The present inventors have repeatedly conducted various trials and errors on a design coating method using a mica pigment, and found that a granular transparent iron oxide pigment composed of manganese-containing hematite is:
When used in combination with metallic pigments, they are nothing but black and yellow transparent pigments, but when used in combination with interference mica pigments and / or pearl mica pigments, a strong flip-flop feeling and excellent color development It has been found that it is possible to obtain a highly designed painted surface having the following characteristics, and that it can be obtained by a simple coating process using a two-coat one-bake method.

Therefore, the present invention provides a design coating method capable of obtaining a highly designed painted surface having a strong flip-flop feeling and excellent color development, and which can be obtained by a simple coating process. An object of the present invention is to provide a design coating film structure and a coating composition for design coating.

[0016]

That is, a design coating method according to the present invention comprises a step of applying an undercoat to a substrate surface to form an undercoat layer, and forming an undercoat layer on the undercoat layer by the general formula: α _{-Fe 2-x Mn x O 3} (x = 0.1~0.7) and granular transparent iron oxide pigments consisting of manganese-containing hematite represented by, and the interference mica pigment mica surface becomes covered with titanium dioxide A step of applying a coating composition containing a color pigment comprising a combination of at least one of the pearl mica pigments to form a colored base coating layer, and applying a clear coating on the colored base coating layer And forming a clear coating layer.

Further, decorative paint coating structure according to the present invention, the undercoating film layer formed on the substrate surface, is formed on the undercoating film layer, the general _{formula: α-Fe 2-x Mn} x O _{3. One of} a granular transparent iron oxide pigment composed of manganese-containing hematite represented by (x = 0.1 to 0.7), an interference mica pigment having a mica surface coated with titanium dioxide, and a pearl mica pigment A colored base coating layer containing a colored pigment composed of a combination of the above and a clear coating layer formed on the colored base coating layer.

In the design coating method and the design coating film structure according to the present invention, "undercoat" and "undercoat" are used regardless of their specific purposes before the topcoat is applied. And all the coating films formed by the coating. Therefore, for example, the middle coat and the middle coat in the case of coating the body of an automobile are “undercoat” and “undercoat”, respectively.

Furthermore, decorative paint coating composition according to the present invention, a resin component consisting of film-forming resin as a vehicle, the general _{formula: α-Fe 2-x Mn} x O 3 (x = 0.1~ 0.7) A pigment comprising a combination of a granular transparent iron oxide pigment composed of manganese-containing hematite represented by the formula: and one or more of an interference mica pigment and a pearl mica pigment whose mica surface is coated with titanium dioxide. And components.

As described above, in the present invention, as the pigment components, a granular transparent iron oxide pigment composed of manganese-containing hematite represented by the above general formula, an interference mica pigment and / or
Or, because a color pigment consisting of a combination system with a pearl mica pigment is used, by the interaction of these pigments,
As is clear from the test results described below, strong flip
A flop feeling and excellent color developing properties, that is, excellent color depth and high hue without turbidity can be obtained together with a unique luster characteristic of mica pigment. The reason why such a high design property is obtained is considered to be related to the wavelength-transmittance characteristics of the transparent iron oxide pigment, but is not clear. In addition, since the transparent iron oxide pigment has a high hiding power, a colored base coating layer of a coating composition containing a coloring pigment composed of a combination of the transparent iron oxide pigment and a mica pigment has a single coating layer on the undercoat coating layer. It can be formed as a film layer. Therefore, a coating specification of two coats and one bake combined with the coating of the clear paint is possible, and a highly designed painted surface can be formed by a simple coating process.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The design coating method, the design coating film structure and the coating composition for design coating used therewith will be described in more detail below.

FIG. 1 is an explanatory view schematically showing a coating film structure by the design coating method of the present invention.

As shown in FIG. 1, the design coating method according to the present invention basically includes a step of forming an undercoat layer 2 by applying an undercoat to the surface of a substrate 1,
A step of forming a colored base coating layer 3 by coating a coating composition containing a color pigment thereon, and a step of forming a clear coating layer 4 by applying a clear coating on the colored base coating layer 3 It consists, where the colored base coating film layer 3, the general _{formula: α-Fe 2-x Mn} x O 3 (x = 0.1~0.7) consists of manganese-containing hematite represented by granular transparent A coloring pigment composed of a combination of an iron oxide pigment 5 and one or more mica pigments 6 of an interference mica pigment whose mica surface is coated with titanium dioxide and a pearl mica pigment is included. The light incident on the colored base coating layer 3 is reflected by the mica pigment 6 as interference light, and a part of the light is reflected by the transparent iron oxide pigment 5, thereby exhibiting high designability as described above. .

The decorative coating composition for forming the colored base coating layer 3 comprises a resin component consisting of a film-forming resin as a vehicle, that is, a resin binder, and a transparent iron oxide pigment 5 thereof. An interference mica pigment or a pearl mica pigment 6 is formed. These components will be described in more detail below.

<Resin Binder> As the resin binder as a vehicle component, any resin material can be used as long as it is a resin capable of forming a film. For example, acrylic resin, polyester resin, urethane resin, epoxy resin Preferably, a curable resin such as a resin or a polyether resin can be used. More specifically, a thermosetting resin composition such as an acrylic-melamine-based, polyester-melamine-based, or acrylic-polyisocyanate-based can generally be preferably used.

[0026] Transparent iron oxide pigments used in the <Transparent iron oxide pigments> present invention have the general formula: is made of a manganese-containing hematite represented by _{α-Fe 2-x Mn x} O 3. This is obtained by dissolving manganese in hempite bengara, and can be generally obtained by a known wet synthesis method. Then, the transparent iron oxide pigment obtained thereby has a black-yellow color (oak color) due to manganese contained therein, while a transparent iron oxide pigment composed of general hematite exhibits reddish brown.

Here, the manganese content of the transparent iron oxide pigment having light transmittance, that is, the value of x in the above general formula is in the range of 0.1 to 0.7. When the content of manganese is too low, and x is generally less than 0.1, the effect of manganese on the color development is weak, and the effect of improving the hiding power cannot be sufficiently obtained. However, too much content tends to reduce its transparency. Therefore, the content of manganese is limited to x = 0.7, and is preferably equal to or less than x = 0.7.

The shape of the transparent iron oxide pigment in the present invention is a granular particle. Here, the granular particles refer to particles exhibiting a substantially isotropic shape such as a spherical shape, a polyhedral shape, a hexahedral shape, and an octahedral shape. It is preferable that the diameter of the particles is as small as possible in order to ensure transparency, and it is generally preferable that the average particle diameter is in the range of 0.005 to 0.5 μm. That is, when the average particle size is larger than 0.5 μm, the shape of the particles in the coating film can be recognized, and it tends to be difficult to obtain a soft glittering texture. On the other hand, an average particle size smaller than 0.005 μm generally makes production difficult. A more preferred particle size is 0.01 to 0.05 μm in average particle size.

The transparent iron oxide pigment can be blended at an arbitrary ratio depending on the desired color. Generally, however, the pigment concentration (PWC) is preferably 5 to 40%. And more preferably 8 to 20%. That is, if the content is too small and the pigment concentration is generally lower than 5%, it is practically difficult to secure a sufficient hiding power. On the other hand, hiding power is improved more as the content of this pigment is increased,
If the amount is too large, not only does the effect thereof reach a plateau, but also the transparency of the colored base coating film layer tends to decrease, and the glittering texture tends to be impaired. Therefore, it is preferable to mix the pigment at a concentration lower than the pigment concentration of 40%.

<Mica Pigment> As the mica pigment, one or both of a pearl mica pigment and an interference mica pigment which are light-transmitting are used. Here, the pearl mica pigment is formed by coating the surface of a scale-like mica with a thin layer of titanium dioxide, and the reflected light interferes to give a milky white pearl luster. In addition, the interference mica pigment is a mica surface coated with titanium dioxide like the pearl mica pigment, but the titanium dioxide layer is thicker than in the case of the pearl mica pigment, and the reflected light interferes and is colored. Depending on the thickness of the titanium dioxide layer, gold, silver, yellow, green, red, blue,
It exhibits a unique interference color of various colors such as purple. In addition, as these mica pigments, those obtained by coating the surface of mica (mica) thinly with tin dioxide and further coating it with titanium dioxide can also be used.

Such pearl mica pigments and interference mica pigments can be used alone or in appropriate combination, respectively, but a stronger flip-flop feeling can be obtained by using interference mica pigments. it can. The interference mica pigments can also be used in an appropriate combination of two or more types having different interference colors, whereby a design painted surface having a unique color mix feeling can be formed.

Further, the amount of the mica pigment to be added can be set at an arbitrary ratio according to a desired color tone or the like. However, when the content is too small, the glittering effect of fine particles independently shining is not sufficiently exhibited, and the flip-flop feeling tends not to be sufficiently obtained. Also, the more the composition, the higher the brightness of the painted surface, but if it is too large, the increase in brightness will not only reach a plateau,
On the contrary, there is a possibility that the high-quality glitter is impaired. Therefore, the compounding amount of the mica pigment is such that the pigment concentration (PWC) is 5
A range of ~ 30% is generally preferred.

It is necessary to use these mica pigments in combination with the above-mentioned granular transparent iron oxide pigments, but the amount of each can be determined independently. However,
In general, the compounding amount is 1: 3 to 3: 1 by weight.
Degree is preferable, and the total amount is based on the pigment concentration (PW
C) is preferably about 15 to 35%.

<Other Ingredients> In the coating composition for design coating used in the present invention, other inorganic pigments or organic pigments may be used as coloring pigments, if necessary, for example, by adjusting the color tone or Can be used to supplement. However, the compounding amount is preferably minimized so as not to impair the high designability obtained by using the color pigment comprising the above-mentioned combination system.

The coating composition may contain additives such as a pigment dispersant, a viscosity modifier, a stabilizer, an antistatic agent, an antioxidant and an ultraviolet absorber, as in the case of general coatings. Can be blended.

<Coating Method> Then, as shown in FIG. 1, when the substrate 1 as an object to be coated is designed and designed, first, an appropriate undercoat is applied to the surface thereof to form an undercoat layer 2. Here, when the base 1 is an outer body plate of an automobile, the undercoating layer 2 may include an undercoating and an intermediate coating by electrodeposition coating. It may include a coating film or a chipping-resistant coating film. Further, for example, when the substrate 1 is made of plastic, the undercoat film layer 2 can be a coating film formed by primer coating. Further, when the substrate 1 is a building, the undercoat layer 2 may include a waterproof coating. That is, this undercoating and the resulting undercoating layer 2
Can be an appropriate coating performed before the overcoating according to the substrate 1 as an object to be coated, and a coating layer formed by the coating. Therefore, the undercoating and the undercoating coating layer 2 by the It may be omitted depending on the type of the base 1 or the like.

Then, as a top coat for finishing, the surface of the undercoat layer 2 is spray-coated with a decorative paint composition containing a color pigment comprising a combination of the above-mentioned transparent iron oxide pigment and mica pigment. The colored base coating layer 3 which exhibits high design properties as described above is formed. In addition, this coloring base coating film layer 3
It can be formed with a thickness similar to that of a normal metallic base coating film, and can generally be formed with a thickness of about 10 to 30 μm. And even with such a relatively thin film thickness, the transparent iron oxide pigment has a strong hiding power,
The undercoat coating layer 2 can be sufficiently hidden.

Further, a clear paint for protecting the surface of the colored base coating layer 3 is applied to form a substantially completely transparent clear coating layer 4. As the resin of the clear coating material, an acrylic resin such as an acrylic / melamine resin is suitable, but an alkyd resin, a urethane resin, or any other resin having high transparency can be used as appropriate. Note that the clear coating layer 4 not only protects the colored base coating layer 3 as a design coating, but also gives the colored base coating layer 3 a glossiness and a depth due to its color. However, the clear coating layer 4 is not absolutely necessary and may be omitted as appropriate in some cases. In that case, the colored base coating layer 3 will be formed as a single finished coating.

In this case, the baking hardening treatment for forming the colored base coating layer 3 and the clear coating layer 4 can be performed for each coating film. However, energy can be saved or the number of coating steps can be reduced. It is preferable to carry out in combination also from the point of. That is, these colored base coating layer 3 and clear coating layer 4
After applying the above-mentioned decorative paint composition, it can be formed by applying a clear paint in a wet-on-wet manner and then baking them simultaneously. That is, 2
The coating can be performed by a one-bake method.

In this manner, various objects to be coated can be coated with the design according to the present invention. This design coating is particularly suitable for coating the body of an automobile, but can be similarly applied to the coating of other vehicles, home appliances, and even buildings.

[0041]

The present invention will be more specifically described below with reference to examples and comparative examples.

FIG. 2 shows the types and amounts of the pigment components used in the design coating methods of Examples 1 to 6 of the present invention, which were experimentally performed, and the evaluation test of the coating film formed thereby. It is a table | surface figure which shows a result. FIG. 3 shows the types and amounts of the pigment components used in the coating methods of Comparative Examples 1 to 6 performed for comparison with the examples, and evaluation tests of the coating films formed thereby. It is a table | surface figure which shows a result.

That is, a transparent base iron oxide pigment (TPO) composed of manganese-containing hematite and one of a pearl mica pigment and an interference mica pigment are blended in the types and amounts shown in FIG. A decorative paint composition for a paint film layer was prepared, and then applied to a test panel previously coated with an undercoat, and then a clear paint was applied to prepare a paint composition of Examples 1 to 6 of the present invention. Design painting was done. Then, the coating film formed thereby was observed, and the flip-flop feeling, the coloring property, and the hiding power were evaluated.
Further, for comparison with these examples, a coating composition for a colored base coating layer was prepared with the types and amounts of the pigments shown in FIG. The coating of Comparative Example 6 was performed, and the flip-flop feeling and the like of the formed coating film were evaluated.

In detail, in each of the examples, the design paint composition for the colored base coating film layer was prepared by dispersing each pigment in an organic solvent solution of a resin component comprising a film-forming resin in advance. This was performed by preparing an iron oxide pigment dispersion paste and a mica pigment dispersion paste, and mixing a predetermined amount of these pigment dispersion pastes.

[Preparation of Transparent Iron Oxide Pigment Dispersion Paste] A dispersion paste of a transparent iron oxide pigment was prepared as follows.

[0046] Here, the transparent iron oxide pigments of the general formula Mn is dissolved in the iron _{oxide: α-Fe 2-x Mn} x O 3 (x = about 0.3) Oak consisting of manganese-containing hematite represented by A color (black yellow) transparent iron oxide pigment (“transparent iron oxide TPO” manufactured by Titanium Industry Co., Ltd.) was used. In addition, this transparent iron oxide pigment has a granular form, and its particle diameter is mainly about 0.03.
μm, which is substantially free from particles of 0.04 μm or more (average particle diameter of about 0.02 μm). Also,
This pigment has heat resistance of 300 ° C. and is excellent in dispersion stability because it is non-magnetic. In addition, this granular transparent iron oxide pigment is described as "TPO" in FIG. 2 and FIG.

Then, an acrylic resin ("Acridic A-322-50" manufactured by Dainippon Ink and Chemicals, Inc.)
(Solid content 50%), 160.0 g of the granular transparent iron oxide pigment, 128.0 g of toluene, and 32.0 g of n-butanol were dispersed in a sand mill for 120 minutes to give a rubbing particle size of 0.04 μm. After that, 224.0 g of an acrylic resin (same as above), 80.0 g of a melamine resin (“Super Beckamine L-125-60” manufactured by Dainippon Ink and Chemicals, Inc./solid content 60%), and toluene 1
72.8 g and n-butanol 43.2 g were added (total 1000.0 g), and the mixture was stirred with a sand mill for 30 minutes to prepare a transparent iron oxide pigment-dispersed paste.

[Preparation of Mica Pigment Dispersion Paste] 80.0 g of the following mica pigments a to f, 512.0 g of an acrylic resin (same as above), and 106.7 g of a melamine resin (same as above)
g and amide wax ("Dispalon 6900-2"
0X "Kusumoto Kasei Co., Ltd./solid content 20%) 16.0 g
, Toluene 228.2 g, and n-butanol 57.1
and m were mixed (1000.0 g in total) to prepare mica pigment pastes a to f, respectively.

The following mica pigments a to f were used: a; Pearl mica pigment (milky white) [Iriodin 103W]
II ”(Merck) b; interference mica pigment (gold)“ Iriodin 205WII ”
(Merck) c; interference mica pigment (red) "Iriodin 215WII"
(Merck) d; interference mica pigment (purple) "Iriodin 219WII"
(Merck) e; interference mica pigment (blue) "Iriodin 225WII"
(Merck) f: interference mica pigment (green) "Iriodin 235WII"
(Merck).

Each of these mica pigments is composed of particles having a particle size of 10 to 40 μm in which the mica surface is coated with tin dioxide, and further coated with titanium dioxide. Present.

[Preparation of Paint Composition for Colored Base Coating Layer (Design Paint Composition)] The above-mentioned transparent iron oxide pigment (TPO)
Mix the dispersion paste and mica pigment dispersion paste,
The colored base coating film-preparable coating composition (colored base layer coating composition) used in Examples 1 to 6 was prepared as follows.

Example 1 25 parts by weight of the transparent iron oxide pigment-dispersed paste and 75 parts by weight of the mica pigment-dispersed paste a were uniformly mixed to prepare a coating composition for a colored base layer used in Example 1. . Therefore, this coating composition has a granular transparent iron oxide pigment (TP) as a pigment component.
O) at a pigment concentration (PWC) of 10% and pearl mica pigment a at a pigment concentration of 15%.

Example 2 25 parts by weight of the above-mentioned transparent iron oxide pigment-dispersed paste and 75 parts by weight of the above-mentioned mica pigment-dispersed paste b were uniformly mixed to prepare a coating composition for a colored base layer used in Example 2. . Therefore, the pigment concentration (PWC) of this coating composition is determined by the granular transparent iron oxide pigment (T
PO) 10% and interference mica pigment b 15%.

Embodiment 3 In Embodiment 3, the blending ratio of the transparent iron oxide pigment in Embodiment 2 is increased and the blending ratio of the mica pigment is reduced. That is, 50 parts by weight of the transparent iron oxide pigment-dispersed paste and 50 parts by weight of the mica pigment-dispersed paste b were uniformly mixed to obtain a coating composition for a colored base layer used in Example 3. Therefore, the pigment concentration (PWC) of this coating composition is 20% of granular transparent iron oxide pigment (TPO) and 10% of interference mica pigment b.

Example 4 75 parts by weight of the transparent iron oxide pigment-dispersed paste and 25 parts by weight of the mica pigment-dispersed paste c were uniformly mixed to prepare a coating composition for a colored base layer used in Example 4. . Therefore, the pigment concentration (PWC) of this coating composition is determined by the granular transparent iron oxide pigment (T
PO) 30% and interference mica pigment c 5%.

Example 5 In Example 5, a plurality of kinds of interference mica pigments were combined and mixed as mica pigments.
That is, 25 parts by weight of the transparent iron oxide pigment dispersion paste,
37.5 parts by weight of the mica pigment dispersion paste d and 37.5 parts by weight of the mica pigment dispersion paste e were uniformly mixed to prepare a coating composition for a colored base layer used in Example 5. Therefore, the pigment concentration (PW
C) is a granular transparent iron oxide pigment (TPO) 10%, an interference mica pigment d 7.5%, and an interference mica pigment e 7.5%.

Example 6 In Example 6, a plurality of types of interference mica pigments were combined and compounded as mica pigments, and the amount of the mica pigments was relatively small. That is, 75 parts by weight of the transparent iron oxide pigment-dispersed paste, 12.5 parts by weight of the mica pigment-dispersed paste f and 12.5 parts by weight of the mica pigment-dispersed paste c are uniformly mixed,
A coating composition for a colored base layer of Example 6 was prepared. Therefore, the pigment concentration (PWC) of this coating composition is 30% granular transparent iron oxide pigment (TPO), and the interference mica pigment c
2.5% and interference mica pigment f2.5%.

<Comparative Examples 1 and 2>
In Comparative Examples 1 and 2, hematite (α) was used as the transparent iron oxide pigment used in the coating composition for the colored base layer.
-Fe2 O3) and a needle-shaped red transparent iron oxide pigment ("Transparent iron oxide TOR", Titanium Industry Co., Ltd.)
) Is blended. Note that this needle-shaped transparent iron oxide pigment (transparent red iron oxide) is referred to as “TO
R ”.

Here, this needle-shaped transparent iron oxide pigment (TO
In the same manner as in the case of the granular transparent iron oxide pigment (TPO), R) is prepared by previously dispersing in a solution of a resin component in an organic solvent to prepare a pigment dispersion paste, and mixing this with a mica pigment dispersion paste. went. More specifically, this needle-shaped transparent iron oxide pigment-dispersed paste has 384.0 g of an acrylic resin (same as above) and 80.0 g of a melamine resin (same as above), similarly to the above-mentioned granular transparent iron oxide pigment-dispersed paste.
And 160.0 g of the needle-shaped transparent iron oxide pigment, 300.8 g of toluene, and 75.2 g of n-butanol were uniformly mixed.

The coating composition for the colored base layer used in Comparative Example 1 was replaced with the acicular transparent iron oxide pigment (TPO) in place of the granular transparent iron oxide pigment (TPO) in Example 2 as a pigment component. TOR). That is, 25 parts by weight of the acicular transparent iron oxide pigment-dispersed paste and 75 parts by weight of the mica pigment-dispersed paste b were uniformly mixed to prepare a coating composition for a colored base layer used in Comparative Example 1. Therefore, this coating composition, as a pigment component,
Acicular transparent iron oxide pigment (TOR) is converted to pigment concentration (PWC)
And the interference mica pigment b at a pigment concentration of 15%.

In Comparative Example 2, an acicular transparent iron oxide pigment (TOR) was used in place of the granular transparent iron oxide pigment (TPO) in Example 6. That is, 75 parts by weight of acicular transparent iron oxide pigment dispersion paste, 12.5 parts by weight of mica pigment dispersion paste c, and mica pigment dispersion paste f1
2.5 parts by weight were uniformly mixed to prepare a coating composition for a colored base layer used in Comparative Example 2. Therefore, the pigment concentration (PWC) of this coating composition is 30% of acicular transparent iron oxide pigment (TOR), 2.5% of interference mica pigment c, 2.5% of interference mica pigment.

Comparative Example 3 In Comparative Example 3, a colored mica pigment (“Iriodin 300WII” manufactured by Merck / particle size: 10 to 40 μm) was used instead of the interference mica pigment b in Example 2.
m, color tone: gold). Here, the colored mica pigment was previously dispersed in an organic solvent solution of a resin component to prepare a pigment-dispersed paste, as in the case of the pearl mica pigment and the interference mica pigment. Specifically, the dispersed paste of the colored mica pigment was prepared by mixing 80.0 g of the colored mica pigment with an acrylic resin (as described above).
512.0 g, and melamine resin (same as above) 106.7 g
And 16.0 g of amide wax (same as above), 228.2 g of toluene, and 57.1 g of n-butanol were uniformly mixed. Then, 75 parts by weight of the colored mica pigment-dispersed paste and 25 parts by weight of the above-mentioned granular transparent iron oxide pigment-dispersed paste were uniformly mixed to obtain a colored base layer coating composition of Comparative Example 3. Therefore, the pigment concentration (PWC) of this coating composition is determined by the granular transparent iron oxide pigment (TP).
O) 10%, colored mica pigment 15%.

Comparative Example 4 In Comparative Example 4, an aluminum powder pigment ("Alpaste 7640NS" manufactured by Toyo Aluminum Co., Ltd.) was used instead of the interference mica pigment b in Example 2.
(Solid content 64%). Here, as in the case of the mica pigment, this aluminum powder pigment (paste) was previously dispersed in an organic solvent solution of a resin binder to prepare and mix a pigment dispersion paste. In particular,
This aluminum powder pigment-dispersed paste was 125.0 g of the aluminum powder pigment (paste), 512.0 g of acrylic resin (same as above), 106.7 g of melamine resin (same as above), and amide wax (same as above).
0 g, toluene 192.2 g, and n-butanol 4
And 8.1 g. Then, 75 parts by weight of this aluminum powder pigment dispersion paste and 25 parts by weight of the above-mentioned granular transparent iron oxide pigment dispersion paste were uniformly mixed to obtain a coating composition for a colored base layer of Comparative Example 4. Therefore, this coating composition contains, as a pigment component, a granular transparent iron oxide pigment (TPO) at a pigment concentration (PWC) of 10%.
% And an aluminum powder pigment at a pigment concentration of 15%.

Comparative Example 5 The coating composition for a colored base layer used in Comparative Example 5 contains only the above-mentioned granular transparent iron oxide pigment (TPO) as a pigment component. Specifically, a coating composition for a colored base layer was formed only from a dispersion paste of a transparent iron oxide pigment composed of the above-mentioned granular Mn-containing hematite. Therefore, this coating composition has a granular transparent iron oxide pigment (TPO) having a pigment concentration (PWC) of 4%.
Include at 0% rate.

Comparative Example 6 The coating composition for a colored base layer used in Comparative Example 6 corresponds to a conventional interference mica paint, and contains only interference mica pigment b as a pigment component. Specifically, mica pigment dispersion paste b
A coating composition for a colored base layer was prepared from only this. Therefore, this coating composition contains the interference mica pigment b at a pigment concentration (PWC) of 20%.

[Preparation of Clear Coating] 466.7 g of acrylic resin (same as above) and 200.0 g of melamine resin (same as above)
g and a solvent ("Solvesso 100", Tonen Petrochemical Co., Ltd.)
257.0 g, n-butanol 64.3 g, and an ultraviolet absorber (“Tinuvin 384” manufactured by Ciba Geigy)
6.0 g of an antioxidant ("Tinuvin 123", manufactured by Ciba Geigy) was mixed with 6.0 g to obtain a clear paint.

[Formation of Decorative Paint Film] Using each of the above paint compositions for a colored base layer, a test panel was coated and finished as follows, and Examples 1 to 6 and Comparative Example 1 were applied.
In addition, the coating films according to Comparative Example 6 were formed.

A 300 × 400 mm tin plate was prepared as a test panel, and on one side surface thereof, a polyester coated as an intermediate coat on an electrodeposition coating film to approximate the actual coating of an automobile body. Apply a resin-based gray intermediate coating (Nippon Paint Co., Ltd.) at a temperature of 140 ° C.
For 18 minutes to form an undercoat layer (lightness L * value: 60) having a thickness of 40 μm.

Then, the paint composition for a paste-like colored base layer according to each of the above Examples and Comparative Examples was thinner (ethyl acetate / toluene / solvesso) on the test panel on which the gray undercoat layer was formed in advance. 150 = 50/3
0/20), and diluted to a dry film thickness of about 15 μm.
Spray-painted (Gun type: Weider 7)
1). Then, after a flash time of 4 minutes, the above clear paint was spray-coated wet-on-wet to a dry film thickness of about 35 μm (gun type:
Wider 61). Then, setting was performed for 10 minutes after the application, and baking was performed at a temperature of 140 ° C. for 18 minutes.

Thus, on the surface of the test panel, an undercoating layer, a colored base coating layer, and a clear coating layer were formed.
The design coating films of Examples 1 to 6 and the coating films of Comparative Examples 1 to 6 were respectively formed, which differed only in the pigment component and the content ratio of the pigmented base coating layer.

[Evaluation Test] Next, each of the thus formed coating films of Examples and Comparative Examples was visually observed, and the flip-flop feeling and the coloring property were evaluated. Separately, an evaluation test on the hiding power of the coating compositions for a colored base layer used in the examples and comparative examples was also performed. The details of each of these evaluation tests are as follows.

<Flip-flop feeling> The flip-flop feeling is obtained by bending the test panel on which the above-mentioned each coating film is formed, observing the painted surface as a curved surface, and visually observing the curved surface perpendicular to the line of sight. The flip-flop feeling (three-dimensional feeling) was evaluated from the difference in brightness between the convex part and the other part oblique to the eyes.

The evaluation was made in four grades of excellent, good, acceptable and unacceptable, that is, the flip-flop feeling was particularly excellent [excellent], the flip-flop feeling was excellent [good], and the flip-flop. The evaluation was performed in four stages: [good] with a slight feeling and [impossible] without a flip-flop feeling.

<Coloring Property> The surface of each of the above-mentioned coating films is visually observed, and the color depth and the high saturation (coloring without turbidity) of the finished surface of the coating are referred to as “coloring property”. Was evaluated.

In addition, the evaluation was the same as described above, in which the color developability was particularly excellent [excellent], the color developability was excellent [good],
Color development is not bad [OK], color development is bad [Not] 4
Performed in stages.

<Hiding power> The hiding power of the colored base coating film layer can be determined from the degree of transparency of the undercoating film layer in the gray color. The hiding power of the layer coating composition was evaluated. That is,
Appropriately dilute each of the above colored base layer coating compositions,
Apply to the surface of black and white hiding power test paper, flash off,
The above clear paint was applied wet-on-wet to a dry film thickness of about 35 μm, and after setting, it was baked at a temperature of 140 ° C. for 18 minutes. Then, the minimum thickness (concealing thickness) of the colored base coating layer when it is impossible to distinguish between a white portion and a black portion through the colored base coating layer (and the clear coating layer) formed in various thicknesses. Was measured.

When the concealing film thickness was 15 μm or less, it was evaluated as good (○), and when it exceeded 15 μm, it was evaluated as unacceptable (x).

[Test Results] The results of the above evaluation tests are shown in FIGS. 2 and 3 together with the types and amounts of the pigment components used in the coating composition for the colored base layer.

As shown in FIG. 2, a particulate manganese-containing hematite pigment (TPO) and a pearl mica pigment or an interference mica pigment are used in combination as a pigment component of a coating composition for a colored base layer, and a combination system thereof is used. Examples 1 to 6 in which a colored base coating layer colored with a pigment was formed
According to the design coating method of the present invention, excellent flip-flop feeling can be obtained in all cases, that is, a strong three-dimensional effect can be obtained on a curved surface portion, and excellent depth of color tone and high saturation (color developing property) can be obtained. ) Is obtained. Furthermore, the colored base coating layer has a high hiding power. Therefore, despite a thin coating layer of about 15 μm, it is possible to perform design coating with a single colored base coating layer, that is, a coating specification of two coats and one bake combined with a clear coating.

From the comparison of the examples, the interference mica pigment tends to have stronger flip-flop feeling and color development than the pearl mica pigment as the mica pigment (see Example 1 and Example 1). Example 2). In addition, the content of the mica pigment is more dominant than the content of the granular manganese-containing hematite pigment (TPO) with respect to the flip-flop feeling and the coloring property. There is also a tendency that the higher the target, the higher the designability can be obtained.

For these embodiments, as shown in FIG.
As a transparent iron oxide pigment, a needle-shaped hematite pigment (TOR) was used, and this was used in combination with an interference mica pigment. -No flop feeling, poor color developability, and low hiding power. On the other hand, as the transparent iron oxide pigment, a granular Mn-containing hematite pigment (TPO) is used as in the example. In Comparative Example 3, which is used in combination with a colored mica pigment, although the flip-flop feeling is slight, Poor. In Comparative Example 4 in which an aluminum pigment was used instead of the colored mica pigment, the flip-flop feeling was not bad, but was not as good as it was, and the coloring property was low. Further, as expected, it is expected that granular Mn-containing hematite pigment (TPO)
Comparative Example 5 and Comparative Example 6 in which the pigment and the interference mica pigment were used alone did not give a flip-flop feeling and had poor coloring properties. Moreover, in Comparative Example 6 using the interference mica pigment alone, the hiding power was low.

From the results of this test, it can be seen from the test results that high designability having a strong flip-flop feeling and excellent color development (high color depth and high hue without turbidity) and a single colored base coating film High hiding power by the layer, as a pigment component,
In particular, it can be seen that it can be obtained only when a granular transparent iron oxide pigment composed of manganese-containing hematite is used in combination with one or more mica pigments of the interference mica pigment and the pearl mica pigment.

Although the present invention has been described by way of examples on a trial basis, the transparent iron oxide pigments, mica pigments, resin materials and the like specifically used here are only examples, and Any other pigment, resin material, or the like may be used within the technical range described above. Also, here, the painting was performed assuming the painting of the car body, but the design painting method of the present invention is not limited to the car body, for example, a vehicle other than a car such as a railway, or a home electric appliance, and the like. It can also be advantageously applied to building panels or buildings.

[0084]

As described above, the design coating method according to the present invention comprises a step of applying an undercoat to the surface of a substrate to form an undercoat layer, and forming an undercoat layer on the undercoat layer by the general formula: _{Fe 2-x Mn x O 3} (x = 0.1~0.7) and granular transparent iron oxide pigments consisting of manganese-containing hematite represented by, formed by coating a mica surface with titanium dioxide interference mica pigment and pearl A step of coating a coating composition containing a color pigment comprising a combination system with one or more of mica pigments to form a colored base coating layer, and applying a clear coating on the colored base coating layer Forming a clear coating layer.

[0085] In addition, decorative paint coating structure according to the present invention, the undercoating film layer formed on the substrate surface, is formed on the undercoating film layer, the general _{formula: α-Fe 2-x Mn} x O _{3. One of} a granular transparent iron oxide pigment composed of manganese-containing hematite represented by (x = 0.1 to 0.7), an interference mica pigment having a mica surface coated with titanium dioxide, and a pearl mica pigment A colored base coating layer containing a colored pigment composed of a combination of the above and a clear coating layer formed on the colored base coating layer.

[0086] Furthermore, decorative paint coating composition according to the present invention, a resin component consisting of film-forming resin as a vehicle, the general _{formula: α-Fe 2-x Mn} x O 3 (x = 0.1~ 0.7) A pigment comprising a combination of a granular transparent iron oxide pigment composed of manganese-containing hematite represented by the formula: and one or more of an interference mica pigment and a pearl mica pigment whose mica surface is coated with titanium dioxide. And components.

Therefore, according to the present invention, the colored base coating film layer is formed by a coating composition using a pigment comprising a combination of a specific transparent iron oxide pigment and a specific mica pigment. Due to the interaction of the pigments, a strong flip-flop feeling can be obtained, and excellent color developability, that is, a deep color feeling and a highly saturated color tone without turbidity can be obtained. In addition to these effects, a painted surface having high design properties can be obtained due to the unique glitter of the mica pigment in which beautifully colored particles shine independently.

Further, since the colored base coating layer formed by the coating composition using the pigment composed of the combined system is excellent in concealing properties, the single colored base coating layer can provide the above-described high designability. A paint film can be formed. Therefore, the colored base coating layer and the clear coating layer as the top coating film can be formed by a two-coat one-bake method, so that the conventional pearl mica coating or interference mica coating performed by a three-coat two-bake method As compared with the case of (1), there is an effect that the coating film with high design can be formed with a higher productivity by a simpler coating process and at a lower cost.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a coating film structure by a design coating method of the present invention.

FIG. 2 shows the types and amounts of pigment components used in the design coating methods of Examples 1 to 6 of the present invention, and the results of evaluation tests of the coating films formed thereby. FIG.

FIG. 3 is a table showing the types and amounts of pigment components used in the coating methods of Comparative Examples 1 to 6, and the results of evaluation tests on the coating films formed thereby. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Undercoat coating layer 3 Colored base coating layer 4 Clear coating layer 5 Granular transparent iron oxide pigment 6 Interference mica pigment (pearl mica pigment)

Claims (3)

[Claims] 1. A subjected to undercoating on the substrate surface, a step of forming an undercoat paint film layer, the undercoating film layer, the general _{formula: α-Fe 2-x Mn} x O 3 (x = 0. 1-0.7) from a combination system of a granular transparent iron oxide pigment composed of manganese-containing hematite represented by the formula (1) and one or more of an interference mica pigment and a pearl mica pigment whose mica surface is coated with titanium dioxide. A step of applying a coating composition containing a colored pigment to form a colored base coating layer, and a step of applying a clear coating on the colored base coating layer to form a clear coating layer. A design painting method characterized by performing. 2. A undercoating film formed on the substrate surface layer is formed on the undercoating film layer, the general _{formula: α-Fe 2-x Mn} x O 3 (x = 0.1~0.7 A) a colored transparent iron oxide pigment composed of manganese-containing hematite represented by the formula (1), and a color pigment composed of a combination of at least one of an interference mica pigment and a pearl mica pigment whose mica surface is coated with titanium dioxide. A design paint film structure comprising: a color base film layer; and a clear film layer formed on the color base film layer. A resin component consisting of 3. A film-forming resin as a vehicle, the general formula: consisting of manganese-containing hematite represented by _{α-Fe 2-x Mn x} O 3 (x = 0.1~0.7) For design coating, comprising a granular transparent iron oxide pigment and a pigment component comprising a combination of at least one of an interference mica pigment and a pearl mica pigment whose mica surface is coated with titanium dioxide. Paint composition.