JP6647694B2 - Glitter coating composition, glitter coating, and method for forming glitter coating - Google Patents

Description

  The present invention provides a glittering coating material in which the luminance changes from a solid color to a metallic color depending on the viewing angle, and the hue also greatly changes, and a glittering coating composition for producing the same, and formation of a glittering coating film About the method.

  2. Description of the Related Art In recent years, in the field of painting, not only a solid color but also a glittering coating film having a glittering glitter has become widespread and has gained popularity in the field of automobiles and the like. This glittering coating film contains glittering pigments such as aluminum metal flakes and silica flakes, which give a glittering glitter. In addition, the surface of the glitter pigment may be coated with an organic pigment or an inorganic pigment, and the light reflected by the surface coating layer and the light reflected by the surface of the glitter pigment passing through the surface coating layer and inside. Can be imparted, and the color changes depending on the viewing angle.

  For example, in Patent Document 1, a silica flake coated with titanium oxide is used as a pigment, and by including this in a coating film, it has a glittering glitter, and from a green color close to yellow to a blue color depending on a viewing angle. Coatings which turn green are described.

JP 2011-25101 A

  However, in the conventional glittering coating as described in Patent Document 1, the range of discoloration is limited, and although it changes from solid color to metallic color depending on the angle, it is difficult to greatly change the hue. Met.

  The present invention has been made in view of the above-described conventional circumstances, and while the luminance changes significantly from a solid color to a metallic color depending on the viewing angle, a glitter paint composition in which the hue also greatly changes, a glitter paint, Another object of the present invention is to provide a method for forming a glittering coating film.

  The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the surface of aluminum particles or silica particles is formed of a blue-based solid color having a specific color gamut with a glitter pigment coated with iron oxide. It has been found that the above problem can be solved by dispersing in a coating film.

That is, the glitter coating composition of the present invention is a glitter coating composition obtained by adding a glitter pigment to a base coating composition capable of forming a solid color coating film,
The brilliant pigment is an iron oxide-coated brilliant pigment in which the surface of aluminum particles or silica particles is coated with iron oxide. The brilliant pigment is based on 100 parts by mass of the resin component in the brilliant coating composition. Pigment is contained in a range of 5 parts by mass or more and 25 parts by mass or less,
The color gamut of the solid color measured by specular reflection at an incident angle of 20 ° of the coating film formed by the base coating composition has an L (20 °) of 17 to 22 and a (20 °) of − It is 1.0 or more and 1.0 or less, and b (20 °) is -3.0 or more and -1.8 or less.

The coating film formed by the glittering coating composition of the present invention has a color shift index defined by the following formula (1) of 0.5 or more, and the luminance greatly changes from a solid color to a metallic color depending on the viewing angle. The hue also changes greatly.

Here, the technical significance of the color shift index is as follows.
B in the color gamut is yellow in the positive direction and blue in the negative direction. Since the iron oxide-coated glitter pigment contained in the glitter coating composition of the present invention has a strong yellowish color due to the effect of the coated iron oxide, the value of b increases in the positive direction. On the other hand, the base coating composition contained in the glittering coating composition of the present invention has a b (20 °) of −3.0 or more and −1.8 or less, and forms a solid color coating film having a strong tendency to blue. I do.
Therefore, when the reflected light of the coating film formed by the glittering coating composition of the present invention changes the hue from the yellowish color of iron oxide depending on the angle to the solid color blue caused by the base coating composition, , B (20 °) −b (40 °) increases. Conversely, when the color does not change much between yellow and blue depending on the angle, the value of b (20 °) −b (40 °) becomes small. That is, the value of b (20 °) −b (40 °) can quantitatively represent a change in hue between yellow and blue. Here, the reason for dividing the value of b (20 °) −b (40 °) by the value of b (40 °) is to indicate the change in hue by a relative value.

  More preferably, the solid gamut of the solid color measured by specular reflection at an incident angle of 20 ° of the coating film formed by the base coating composition has L (20 °) of 18 or more and 21 or less, and a ( (20 °) is -0.9 or more and 0.9 or less, and b (20 °) is -2.8 or more and -1.7 or less.

  The content of the brilliant pigment in the brilliant coating composition may be appropriately selected according to the composition of the base coating composition, but is preferably based on 100 parts by mass of the resin component in the brilliant coating composition of the present invention. It is necessary that the brilliant pigment is contained in an amount of at least 5 parts by mass or more and at most 25 parts by mass or less (here, the resin component also includes a curing agent). According to the test results of the inventors, when the glitter pigment is less than 5 parts by mass or more than 25 parts by mass with respect to 100 parts by mass of the resin component in the glitter coating composition, the color shift index is 0. .5, and further, a large change from a solid color to a metallic color depending on the viewing angle may not be recognized.

  A step of coating the glitter coating composition of the present invention on the surface of a substrate (coating step) and a step of curing the glitter coating composition coated on the substrate to form a coating film (curing step) By doing so, it becomes a brilliant paint in which the luminance varies widely from a solid color to a metallic color depending on the viewing angle, and the hue greatly changes from a blue-based color to a red-based color. In addition, the glittering coating product thus obtained can exhibit glittering properties without forming a clear coating film on the glittering base coating film.

Further, the glittering coating product of the present invention is a glittering coating product having a glittering coating film formed on the surface of a substrate,
The glitter coating film is obtained by dispersing a glitter pigment in a solid color coating film,
The brilliant pigment is an iron oxide-coated brilliant pigment in which the surface of aluminum particles or silica particles is coated with iron oxide. The brilliant pigment is based on 100 parts by mass of the resin component in the brilliant coating composition. Pigment is contained in a range of 5 parts by mass or more and 25 parts by mass or less,
The color gamut of the solid color measured with specular reflection light at an incident angle of 20 ° has an L (20 °) of 17 or more and 22 or less, a (20 °) of -1.0 or more and 1.0 or less, b (20 °) is −3.0 or more and −1.8 or less.
In this glittering coating, the color shift index of the glittering coating film defined by the above-described formula (1) is 0.5 or more, and the luminance greatly changes from a solid color to a metallic color depending on the viewing angle. Also vary greatly.

Cross-section and reflection when the solid pigmented coating contains the iron oxide-coated brilliant pigment (left side) and when the solid pigmented coating contains the organic pigment-coated brilliant pigment (right side). It is a schematic diagram of light. The vertical axis represents the solid color (a) of the coating film containing no glittering pigment, and the horizontal axis represents the parts by weight of the iron oxide-coated glittering pigment with respect to 100 parts by weight of the resin component in the glittering coating composition. 6 is a graph showing a color shift determination result.

<Glitter coating composition>
In the glitter coating composition of the present invention, a glitter pigment is added to a base coating composition capable of forming a solid color coating film. Here, the brilliant pigment refers to a pigment that imparts glittering properties such as metallic or pearl to the coating film by being dispersed in the coating film. Further, the solid color means a single color that does not contain a glittering pigment.

As the glitter pigment, an iron oxide-coated glitter pigment obtained by coating the surface of aluminum (Al) particles or silica (SiO ₂ ) particles with iron oxide is used. The aluminum (Al) particles and the silica (SiO ₂ ) particles are preferably flaky (that is, flake-like) particles from the viewpoint of increasing glitter.

  These glitter pigments are added to a base paint composition capable of forming a solid color coating film to provide a glitter paint composition of the present invention. The content ratio of the iron oxide-coated glittering pigment is included in the range of 5 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the resin component in the glittering coating composition. What is necessary is just to adjust suitably according to the kind of glitter pigment.

  As the base coating composition, a solid color coating film can be formed, and the color gamut of the solid color measured by specular reflection at an incident angle of 20 ° is L (20 °) of 17 or more and 22 or less, It is a requirement that a (20 °) is −1.0 or more and 1.0 or less, and b (20 °) is −3.0 or more and −1.8 or less. As long as the coating composition satisfies this requirement, the type of the coating component is not particularly limited. For example, acrylic resin coating, epoxy resin coating, urethane resin coating, melamine resin coating, polyester resin coating, fluororesin coating, etc. A coating composition can be used. The type of the pigment to be added is not limited as long as the solid color falls within the above range, and an organic pigment or an inorganic pigment can be used.

  The color gamut of the solid color of the coating film may be slightly different depending on the thickness of the coating film and the material and color of the base, but in the present specification, the coating was applied on a white polycarbonate plate with a thickness of 20 μm. It is defined as L (20 °) a (20 °) b (20 °) value when measured using a painted object. This color gamut indicates that the solid color is blue. The thickness of the coating film is preferably 15 μm or more and 30 μm or less, more preferably 20 μm or more and 25 μm or less. If the thickness of the coating film is less than 15 μm, the solid feeling may be overemphasized, and if the thickness of the coating film exceeds 30 μm, the metallic feeling may be overemphasized.

<Method of forming glittering coating film>
In order to form a glittering coating film using the glitter coating composition described above, first, as a coating step, the glitter coating composition is coated on the surface of a substrate. The substrate is not particularly limited, but iron, plastic, wood, pottery, and the like can be used. In order to improve the adhesion to the base material, a chemical conversion treatment film may be formed or coated with a base paint.

  Next, as a curing step, a heat is applied to the coated glittering coating composition or ultraviolet rays or the like are applied to form a coating film. In addition, in the conventional method for forming a glitter coating film, coating with a clear paint is often performed in the end, but in the glitter paint composition of the present invention, coating with a clear paint does not need to be performed. It is a great feature of the method for forming a glitter coating film of the present invention that the glitter is sufficiently exhibited even in this case.

−Principle−
The reason why the brilliant coating of the present invention changes from solid color to metallic color depending on the viewing angle, and furthermore the hue also changes significantly is not completely elucidated, but is presumed to be due to the following reasons. .
That is, as shown in the left side of FIG. 1, when the iron oxide-coated brilliant pigment is dispersed in the solid color coating film, the iron oxide-coated brilliant pigment having a large specific gravity sinks, and the solid color coating is laid thereon. A membrane will be present. For this reason, the light entering obliquely (shade portion) has a longer optical path through the solid color coating film at a higher angle, and the influence of the solid color S increases. On the other hand, the light incident from the front (highlight) has a short optical path through the solid color coating film, so that the light is hardly affected by the solid color, and is reflected by the iron oxide-coated brilliant pigment to form a metallic color M. Get closer. As a result, the color gamut greatly changes from the solid color S to the metallic color M depending on the viewing angle.
On the other hand, as shown in the right side of FIG. 1, when the organic pigment-coated glittering pigment is dispersed in the solid color coating film, the organic pigment-coated glittering pigment having a small specific gravity exists near the surface without sinking. For this reason, even if the light is incident from an oblique direction (shade portion), the light path passing through the solid color coating film is short, and is hardly affected by the solid color, and the metallic color M is obtained. As a result, although the color changes due to the interference color, the phenomenon that the color gamut from the solid color S to the metallic color M greatly changes depending on the viewing angle does not occur.

<Example>
Hereinafter, examples embodying the present invention will be described in comparison with comparative examples.
The glitter pigments used in Examples and Comparative Examples and the transparent pigments for preparing solid colors are listed below.
Meoxal AtacamaRed: iron oxide-coated aluminum pigment, manufactured by Merck, particle size 5-25 μm, highlight color: red
Paliocrom SparkringRed L3505: Iron oxide coated aluminum pigment, manufactured by BASF, average particle diameter 20 μm, highlight color: red
FriendColor D451 RE: Colored aluminum pigment, made by Toyo Aluminum, average particle size 11μm, Highlight color: Red
FriendColor D111 RE: colored aluminum pigment, made by Toyo Aluminum, average particle size 23μm, highlight color: red
Colorstream LavaRed: Iron oxide-coated silica flake pigment, manufactured by Merck, particle size 5-40 μm, highlight color: red
CZ-9665: Highly transparent pigment, manufactured by Hikitsu Bix Co., Ltd. Highlight color: Blue

(Preparation of base coating compositions (1) to (5))
By performing the following steps S1 to S3, base coating compositions (1) to (5) capable of forming a solid color coating film were prepared.
Step S1 (Preparation of acrylic resin composition)
The flask was charged with 56.2 parts by mass of methyl isobutyl ketone and heated to 90 ° C. under a N ₂ atmosphere. And separately, 20.0 parts by weight of methyl methacrylate, 3.0 parts by weight of 2hydroxyethyl methacrylate, 20.0 parts by weight of butyl methacrylate, 0.5 part by weight of methacrylic acid and an oil-soluble azo initiator 1,1'-Azobis (cyclohexane-1- A solution prepared by mixing 0.3 parts by mass of carbonitrile) was dropped into the flask containing methyl isobutyl ketone over 100 minutes, and after the entire amount was charged, the polymerization reaction was performed by continuing stirring for 3 hours. An acrylic resin composition was obtained.
・ Step S2 (Preparation of clear paint)
19.8 parts by mass of ethyl acetate and 0.2 parts by mass of a silicon-based surface conditioner (BYK333 manufactured by BYK-Chemie) were added to 80.0 parts by mass of the acrylic resin composition obtained in step S1, and mixed to prepare a clear paint.
Step S3 (Preparation of base coating compositions (1) to (5))
To the clear paint obtained in step S2, a predetermined amount of an isocyanate-based curing agent (basonate HI-100) and a blue-based color pigment CZ-9665 (highly transparent processed pigment manufactured by Nikko Bix Co., Ltd.) (Table 1) References) were added and mixed to prepare base coating compositions (1) to (5) capable of forming a solid color.

(Color gamut measurement of base coating compositions (1) to (5))
The color gamut of the base coating compositions (1) to (5) prepared as described above was measured. That is, each base coating composition is spray-coated on a white polycarbonate resin plate (polycarbonate sheet NF-2000C manufactured by Mitsubishi Gas Chemical Co., Ltd.), cured, and then solidified using SolidSpec3700 (manufactured by Shimadzu Corporation). The absorption spectrum was measured at 800 nm. At that time, the measurement was performed at an incident angle of 20 °, and the specular reflection light was received to obtain an absorption spectrum, and the values of L, a and b were determined. Table 1 shows the results.

(Examples 1 to 8)
In the glittering coating products of Examples 1 to 8, the base coating composition (3) shown in Table 1 was used, and various glittering pigments (In Examples 1 to 4, Meoxal AtacamaRed was used as iron oxide-coated aluminum flakes. In Examples 5 to 8, a glittering coating composition prepared by adding a predetermined amount (see Table 2) of iron oxide-coated aluminum flakes was used.

(Examples 9 to 13)
In the glittering coating products of Examples 9 to 13, the base coating compositions (1) to (5) shown in Table 1 were used, and a glittering pigment (iron oxide coating in Examples 9 and 11 to 13) was used. A glittering coating composition prepared by adding a predetermined amount (see Table 2) of Meoxal AtacamaRed as aluminum flakes and Meoxal AtacamaRed and Sparkling Red as iron oxide-coated aluminum flakes in Example 10 was used.

(Example 14)
In the glittering coating product of Example 14, the base coating composition (3) shown in Table 1 was used, and ColorStream LavaRed was used as the iron oxide-coated silica flake, based on 100 parts by mass of the resin component in the coating material. A glitter coating composition prepared by adding parts by mass was used.

(Comparative Examples 1-4)
The glitter paints of Comparative Examples 1 to 4 used the base paint composition (3) shown in Table 1, and added various glitter pigments (in Comparative Example 1, Meoxal Atacama Red as iron oxide-coated aluminum flakes, Comparative Example 2). In Comparative Example 3, a brilliant coating composition prepared by adding a predetermined amount (see Table 3) of FriendColor D451 RE as an organic pigment-coated aluminum flake and in Comparative Example 4 as FriendColor D111 RE as an organic pigment-coated aluminum flake was used. .

(Comparative Example 5 and Comparative Example 6)
In the glittering coating product of Comparative Example 5, the base coating composition (3) shown in Table 1 was used, and Meoxal AtacamaRed as an iron oxide-coated aluminum flake was used in an amount of 39.4 based on 100 parts by mass of the resin component in the coating material. A glitter coating composition prepared by adding parts by mass was used. Further, in the glittering coated product of Comparative Example 6, the base coating composition (2) shown in Table 1 was used, and Meoxal AtacamaRed as iron oxide-coated aluminum flakes was used in an amount of 2.6 parts by mass based on 100 parts by mass of the resin component. A glittering coating composition prepared by adding a part thereof was used.

(Comparative Examples 7 to 9)
The glittering coatings of Comparative Examples 7 to 9 were prepared using the base coating composition (3) shown in Table 1 and adding a predetermined amount (see Table 3) of Colorstream LavaRed as iron oxide-coated silica flakes. A bright coating composition was used.

The glitter coating composition prepared as described above was applied on a white polycarbonate plate so as to have a predetermined film thickness, and allowed to stand for 24 hours or more. The glitter of Examples 1 to 14 and Comparative Examples 1 to 9 was performed. A painted product was produced (see Tables 2 and 3).
Then, the white polycarbonate plate was broken along with the coating film, and the cross section was observed with an optical microscope (700 times) to measure the thickness of the coating film. Further, absorption spectra were measured by using SolidSpec3700 (manufactured by Shimadzu Corporation) to receive each specularly reflected light at an incident angle of 20 ° and 40 ° within a wavelength range of 300 nm to 800 nm. Furthermore, the values of L, a, and b at incident angles of 20 ° and 40 ° were determined from the results.
Further, the produced glittering coating was visually judged under the environment of a standard light source (SpectraLightQC D65 manufactured by X-rite) (this judgment is referred to as “color shift judgment”). At the time of observation, the illumination angle was changed, and changes in hue and luminance from highlight (low angle) to shade (high angle) were evaluated according to the following evaluation criteria.
：: A remarkable change in both hue and luminance is observed from high luminance red in highlight to solid blue in shade.
Δ: Changes in both hue and luminance from high luminance red in highlight to solid blue in shade.
X: There is no or very little change in hue and luminance from highlight to shade.
The evaluation was carried out by five designers and three technicians who have been engaged in color development for three years or more, each of which was individually evaluated, and the evaluation was decided by a majority vote of nine people.

  The results are shown in Tables 2 and 3. From this table, it was found that in the glittering coating products of Examples 1 to 14, the color shift index was in the range of 0.50 to 1.58, and the color changed significantly depending on the viewing angle. In the color shift determination, Examples 1 to 13 were evaluated as ○, and it was found that red was high in brightness at low angles but solid blue at high angles (shade portions). The color shift determination was evaluated as Δ in Example 14, indicating that both the hue and the luminance changed from the high-luminance red in the highlight to the solid blue in the shade.

On the other hand, in Comparative Examples 1 to 7, the color shift index was in the range of 0.25 to 0.38, and it was found that the change in color depending on the viewing angle was smaller than in Examples 1 to 14. In addition, the color shift was evaluated as x in the determination, and the bright red was not obtained even at a low angle, and a wide range of change from a metallic color to a solid color was not recognized. Although the color shift index was comparatively large at 0.76 in Comparative Example 8 and 1.01 in Comparative Example 9, both were evaluated as x in the color shift determination, and the hue / luminance change from highlight to shade was evaluated. Was hardly recognized

<Discoloration from solid color to metallic color depending on viewing angle>
In Examples 1 to 13 and Comparative Examples 1, 5, 6, 8 and 9 using the iron oxide-coated bright pigment, the vertical axis represents the solid color (a) of the coating film without the bright pigment, and the horizontal axis represents the horizontal axis. FIG. 2 is a graph showing the results of color shift determination when the axis is defined as 100 parts by mass of the resin component in the glittering coating composition and 100 parts by mass of the iron oxide-coated glittering pigment. From this figure, when the amount of the iron oxide-coated glittering pigment is less than 5 parts by mass or exceeds 25 parts by mass with respect to 100 parts by mass of the resin component in the glittering coating composition, the solid color changes from a solid color to a metallic color depending on the viewing angle. It was found that no discoloration was observed.

  The present invention is not limited to the description of the embodiment of the present invention. Various modifications are included in the present invention without departing from the scope of the claims and within the scope of those skilled in the art.

Claims (5)

A glitter paint composition in which a glitter pigment is added to a base paint composition capable of forming a solid color coating film,
The brilliant pigment is an iron oxide-coated brilliant pigment in which the surface of aluminum particles or silica particles is coated with iron oxide. The brilliant pigment is based on 100 parts by mass of the resin component in the brilliant coating composition. Pigment is contained in a range of 5 parts by mass or more and 25 parts by mass or less,
The base paint composition is obtained by adding a blue color pigment to a clear paint, and the amount of the blue color pigment added is specular reflection light at an incident angle of 20 ° of a coating film formed by the base paint composition. In the color gamut of the solid color measured in the above, L (20 °) is 17 or more and 22 or less, a (20 °) is -1.0 or more and 1.0 or less, and b (20 °) is -3. A brilliant coating composition, which is adjusted so as to be 0 or more and -1.8 or less. The glitter coating composition according to claim 1, wherein a color shift index defined by the following formula (1) of the coating film formed by the glitter coating composition is 0.5 or more.

A glittering coating product in which a glittering coating film is formed on the surface of the base material,
A glitter paint, wherein the glitter coat is formed using the glitter paint composition according to claim 1 or 2 . The glittering coated article according to claim 3, wherein the glittering coating film has a color shift index defined by the following formula (1) of 0.5 or more.

A coating step of coating the glitter coating composition according to claim 1 or 2 on a surface of a substrate,
Curing the glitter coating composition coated on the substrate to form a coating film.

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