JP2021138844A - Composition for forming brilliant coating film - Google Patents

Abstract

To provide a composition for forming a brilliant coating film, which can form a coating film which changes its brilliance and hue very drastically depending on the angle of observation.SOLUTION: Provided is a composition for forming a brilliant coating film, comprising brilliant particles P and a coloring pigment C. The brilliant particle comprises aluminum, a reflective layer covering the aluminum, and an iron oxide layer covering the reflective layer. In a coating film of 20 μm thickness formed on standard coat paper by using the composition for forming a brilliant coating film, when visible light is made incident on the coating film at an incident angle of 45°, an a* value of L*a*b* color system of light emitted in a direction tilted by 75° from a regular reflection direction towards the incident direction is less than 17 and a b* value is less than 5.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composition for forming a brilliant coating film.

In recent years, various coating film forming compositions for enhancing the design of various products such as automobiles and home appliances have been developed. One of them is a coating film forming composition capable of forming a coating film whose color changes depending on the observation angle (hereinafter, also referred to as "color shift"). As such a coating film forming composition, Patent Document 1 describes a composition containing a silica flake pigment coated with titanium oxide. The coating film obtained from the composition changes color from green close to yellow to green close to blue. However, in the technique of Patent Document 1, discoloration is caused by utilizing the interference of light, and the range of discoloration is limited. That is, it has been difficult to significantly change the color of the obtained coating film with the coating film forming composition containing the silica flake pigment.

On the other hand, Patent Document 2 proposes a coating film-forming composition containing aluminum-based particles and a coloring pigment. According to the coating film forming composition, the color and brightness of the obtained coating film can be changed more significantly than when the silica flake pigment is contained. Further, Patent Document 3 describes that the aluminum-based particles and the coloring pigment are included in the coating film forming composition in order to enhance the saturation, brightness, hiding power and the like of the obtained coating film.

Japanese Unexamined Patent Publication No. 2011-25101 Japanese Unexamined Patent Publication No. 2018-80276 Special Table 2018-524447

Among the above, according to the technique of Patent Document 2, it is possible to greatly change the color and brightness of the coating film. However, in recent years, it has been required to further increase the range of change in the color and brightness of the coating film, and it is desired to provide a composition for forming a brilliant coating film capable of forming such a coating film.

The present invention has been made in view of the above problems. Specifically, it is an object of the present invention to provide a composition for forming a brilliant coating film capable of forming a coating film whose brightness and color change significantly depending on the observation angle.

The present invention provides the following composition for forming a brilliant coating film.
[1] A composition for forming a brilliant coating film containing brilliant particles and a coloring pigment, wherein the brilliant particles include aluminum, a reflective layer covering the aluminum, and an iron oxide layer covering the reflective layer. A coating film having a thickness of 20 μm, which is formed on a standard coated paper using the composition for forming a brilliant coating film, has a normal reflection direction when visible light is incident on the coating film at an incident angle of 45 °. For forming a brilliant coating film, ^{the L *} a ^* b ^* color system a ^* value of light emitted in a direction inclined by 75 ° toward the incident direction is less than 17, and the b ^{* value is less than 5.} Composition.

[2] The composition for forming a brilliant coating film according to [1], wherein the amount of iron element per 1 part by mass of aluminum element in the brilliant particles is 0.05 to 4 parts by mass.

[3] The composition for forming a brilliant coating film according to [1] or [2], wherein the reflective layer contains silicon dioxide.

[4] The composition for forming a brilliant coating film according to [3], wherein the amount of the silicon element per 1 part by mass of the aluminum element in the brilliant particles is 0.05 to 0.5 parts by mass.

[5] The composition for forming a brilliant coating film according to any one of [1] to [4], further comprising a fatty acid amide compound.
[6] The composition for forming a brilliant coating film according to any one of the above [1] to [5], which is a composition for a paint.
[7] The composition for forming a brilliant coating film according to any one of [1] to [5], which is a composition for ink.

According to the composition for forming a brilliant coating film of the present invention, it is possible to form a coating film whose brightness and color change significantly depending on the observation angle.

FIG. 1 is a diagram schematically showing the reflection of light in a coating film obtained from the composition for forming a brilliant coating film of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the present specification, the numerical range indicated by "-" means a numerical range including the numerical values described before and after "-".

In the notation of a group (atomic group) in the present specification, the notation that does not indicate whether it is substituted or unsubstituted includes both those having no substituent and those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
The notation "(meth) acrylic" herein represents a concept that includes both acrylic and methacryl. The same applies to similar notations such as "(meth) acrylate".

<Composition for forming a brilliant coating film>
The composition for forming a brilliant coating film of the present invention is a composition for forming a coating film whose brightness changes greatly depending on an observation angle and whose color also changes greatly. The composition for forming a brilliant coating film of the present invention is a composition for forming a brilliant coating film containing brilliant particles and a coloring pigment, and the brilliant particles are aluminum, a reflective layer covering the aluminum, and the like. A coating film having a thickness of 20 μm, which has an iron oxide layer covering the reflective layer and is formed on a standard coated paper using the composition for forming a brilliant coating film, is visible to the coating film at an incident angle of 45 °. ^{When light is incident, the L *} a ^* b ^* color system a ^* value of the light emitted in the direction inclined by 75 ° from the normal reflection direction toward the incident direction is less than 17, and the b ^* value is 5. Is less than.

The present inventors have a specific structure of the glitter particles contained in the composition for forming a glitter coating film, and the above-mentioned a ^* value and b ^* value of the coating film formed on the standard coated paper are predetermined. It was found that by designing the composition so as to be within the range, the brightness of the obtained coating film changes greatly, and the color also changes greatly.

The reason is not clear, but the following mechanism is inferred. As shown in the schematic diagram of FIG. 1, in the coating film containing the glitter particles P and the coloring pigment C, when light is incident from a certain direction (the direction indicated by L in FIG. 1), the light is reflected in each direction. Will be done. The light reflected by the glitter particles P and the coloring pigment C is mainly reflected in the specular reflection direction. Depending on the characteristic of strongly reflecting light on the brilliant particle P (brilliance), the specular reflection direction of light (direction indicated by R in FIG. 1) or a direction close to this (direction indicated by H in FIG. 1), these are summarized below. (Also referred to as “highlight H side”), the light reflected by the brilliant particles P is mainly observed rather than the light reflected from the coloring pigment C. On the other hand, in a direction greatly separated from the specular reflection direction R, for example, a direction close to the incident direction L of light (hereinafter, the direction indicated by S in FIG. 1, hereinafter also referred to as “shade S side”) as a whole. Since the reflected light is weakened, the color derived from the coloring pigment C is mainly observed rather than the reflected light from the glittering particles P.

When the glittering particles P contained in such a coating film have a reflective layer between the aluminum and the iron oxide layer, more light is reflected to the highlight H side by the reflective layer. Further, in the glittering particles P, the light reflected at the interface between the aluminum and the reflective layer and the light reflected at the interface between the iron oxide layer and the reflective layer interfere with each other, and the light becomes more complicated on the highlight H side. Is reflected in. Therefore, when light is incident from a certain direction, the brightness of the coating film on the highlight H side is remarkably increased, and the color derived from the brilliant particles P is observed more strongly on the highlight H side. Therefore, the change in brightness becomes much larger than that in the conventional coating film, and the range of change in color is widened.

Here, the bright particles used in the composition for forming a bright coating film of the present invention are coated with iron oxide, and the color thereof is close to red to yellow. Therefore, when observing the coating film of the composition for forming a brilliant coating film, many colors close to red or yellow are observed on the highlight H side.

On the other hand, in the present invention, when light is incident on the coating film from a certain direction, the a ^* value of the coating film observed on the shade S side close to the incident direction is less than 17, and the b ^* value is less than 5. As described above, the composition of the composition for forming a brilliant coating film is adjusted. ^{When the a *} value on the shade S side is less than 17, and the b ^* value is less than 5, blue, green, or a color close to this is observed on the shade S side. That is, on the shade S side, a color having a hue greatly different from that of red or yellow (for example, blue or green) is observed. Therefore, when the observation angle is changed from the shade S side to the highlight H side, the color of the coating film changes from the color derived from the coloring pigment C to the color of the brilliant particles P, and the brightness changes from a low state to a high state. Change. Therefore, according to the composition for forming a brilliant coating film of the present invention, it can be said that a coating film capable of deep design expression can be obtained.

Here, the "chromaticity" of the coating film obtained from the above-mentioned composition for forming a brilliant coating film in the present specification will be described in detail below.

The chromaticity of the coating film is measured as follows. First, a coating film of the composition for forming a brilliant coating film having a thickness of 20 μm is formed on a standard coated paper. Then, as shown in FIG. 1, visible light having a wavelength of 400 to 700 nm is incident on the coating film at an incident angle of 45 ° (from the direction indicated by L in FIG. 1). Further, the specular reflection direction (direction indicated by R in FIG. 1) at this time is set to 0 °, the light source side is set to be positive, and the side away from the light source is set to negative. Then, the shade S side (the direction indicated by S in FIG. 1, the angle θ2 = 75 ° from the specular reflection direction) and the highlight H side (the direction indicated by H in FIG. 1, the angle θ1 = 15 ° from the specular reflection direction). In, the a ^* value and the b ^* value of the L ^* a ^* b ^* color system are measured. ^{Further, the a *} value and the b ^* value of the shade S side (75 °) and the highlight H side (−15 °) are similarly measured at another part of the coating film. Then, the average of the measured values at the three points on the coating film is defined as the chromaticity (a ^* value and b ^* value) on the shade S side (75 °) and the highlight H side (-15 °), respectively. In addition, in this specification, the said standard coated paper means the coated paper which conforms to the Japan color standard of ISO standard.

Here, the composition for forming a brilliant coating film of the present invention has an a ^* value (hereinafter, also referred to as “a ^* _{(75 °)} ”) observed on the shade S side (75 °) of −50 or more 17 More preferably, it is designed to be less than. Further, ^{it is more preferable that b *} _{(75 °)} is designed to be -50 or more and less than 5. When the composition for forming a brilliant coating film is designed so that the color of the coating film on the shade S side satisfies these, the color becomes larger on the highlight H side and the shade S side (depending on the observation angle). Change. In addition, a ^* _{(75 °)} and b ^* _{(75 °)} can be adjusted by the type and combination of coloring pigments described later.

^{On the other hand, the a *} value (hereinafter, also referred to as "a ^* _{(-15 °)} ") observed on the highlight H side (-15 °) of the coating film of the composition for forming a brilliant coating film of the present invention is It is preferably designed to be -30 to 90, and the b ^* value (hereinafter, also referred to as “b ^* _{(−15 °)} ”) is more preferably designed to be -30 to 90. a ^* _{(-15 °)} is more preferably -20 to 60, and b ^* _{(-15 °)} is more preferably -20 to 60. When a ^* _{(-15 °)} and b ^* _{(-15 °)} are designed to be in the above range, red, yellow, or a color close to this is observed on the highlight H side. In addition, a ^* _{(-15 °)} and b ^* _{(-15 °)} can be adjusted by the amount of iron element of the brilliant particles described later.

Furthermore, the composition for forming a brilliant coating film of the present invention is preferably designed so that the hue change index of the coating film, which is obtained by the following formula, is 0.5 or more. The hue change index of the coating film is more preferably 0.6 or more, further preferably 0.7 or more, further preferably 1.0 or more, and particularly preferably 1.5 or more. The hue change index is observed on the shade S side (75 °) and the highlight H side (-15 °) at the coordinates with ^{the a *} value on the horizontal axis and the b ^{* value on the vertical axis.} Represents the slope of the straight line connecting these when each color is represented. The larger the hue change index of the coating film, the greater the change in the hue of the coating film. In the present specification, hue is one of the three family attributes of color, and is a difference in hue such as red, orange, yellow, green, blue, and purple. That is, the fact that the hue change index of the coating film is large means that the hue (color appearance such as red, orange, yellow, green, blue, and purple) changes greatly depending on the observation angle. ^{The a *} value and b ^* value in the equation are values obtained by the above method.

Further, the composition for forming a brilliant coating film of the present invention is preferably designed so that the discoloration index of the coating film, which is obtained by the following formula, is larger than 10. The discoloration index of the coating film is more preferably 20 or more, further preferably 30 or more, more preferably 50 or more, still more preferably 60 or more. The discoloration index of the coating film is the color observed on the shade S side (75 °) and the color observed on the highlight H side (-15 °), with the a ^* value on the horizontal axis and the b ^* value on the vertical axis. Represents these distances when expressed in the coordinates to be. The fact that the distance is large means that the ^{coordinates consisting of the a *} value and the b ^* value change greatly depending on the observation angle. That is, the fact that the discoloration index of the coating film is large means that the ^{coordinates consisting of the a *} value and the b ^* value change greatly depending on the observation angle, and the degree of discoloration changes greatly. ^{The a *} value and b ^* value in the equation are values obtained by the above method.

Then, when the composition for forming a brilliant coating film is designed so that the hue change index of the coating film and the discoloration index of the coating film satisfy the above values, the coating film of the brilliant coating film forming composition becomes From the shade S side to the highlight H side, the color is very large and easily changes.

The composition for forming a brilliant coating film is also described as an ^{L *} a ^* b ^* color system L ^* value (hereinafter, "L ^* _{(75 °)} ") on the shade S side (75 °) of the coating film. ) Is preferably designed to be 30 or more, more preferably 42 or more, further preferably 50 or more, and particularly preferably 60 or more. On the other hand, ^{the upper limit of L *} _{(75 °)} is preferably designed to be 150 or less, more preferably 120 or less, further preferably 100 or less, and particularly preferably 90 or less.

^{In addition, the upper limit of the L *} a ^* b ^* color system L ^* value (hereinafter, also referred to as "L ^* _{(-15 °)} ") on the highlight S side (-15 °) of the coating film is 1 or more. The lower limit of L ^* _{(-15 °)} is more preferably 5 or more, further preferably 10 or more, and particularly preferably 20 or more. On the other hand, ^{it is preferable that the upper limit of L *} _{(-15 °)} is 90 or less, more preferably 70 or less, further preferably 50 or less, and particularly preferably 40 or less.

^{When the L *} values on the shade S side (75 °) and highlight H side (-15 °) satisfy the above ranges, respectively, on the shade S side (75 °) and highlight H side (-15 °) of the coating film, respectively. , Each color becomes easier to see vividly, and the color change of the coating film becomes easier to recognize. L ^* _{(75 °)} and L ^* _{(-15 °)} can be measured by the same method as the above-mentioned chromaticity (a ^* value and b ^{* value) measurement.} That is, a coating film of the composition for forming a brilliant coating film having a thickness of 20 μm is formed on a standard coated paper, and the coating film has an incident angle of 45 ° (from the direction indicated by L in FIG. 1) and a wavelength of 400 to 700 nm. It is the ^{L *} value on the shade S side (75 °) and the highlight H side (-15 °) when visible light is incident.

Hereinafter, each component of the composition for forming a brilliant coating film will be described. The composition for forming a brilliant coating film may further contain a fatty acid amide compound, a solvent, various additives, and the like, if necessary.

(1) Bright particles The bright particles have aluminum as a core, a reflective layer covering the aluminum, and an iron oxide layer covering the reflective layer. That is, it is a particle having two layers of a reflective layer and an iron oxide layer on aluminum.

The aluminum contained in the brilliant particles may usually be in the form of particles, and it is preferable that the aluminum is in the form of flat particles from the viewpoint that the brightness and color are easily changed depending on the angle. A passivation layer may be arranged around the aluminum as long as the object and effect of the present invention are not impaired.

When the aluminum is flat, its shape may be flat or partially curved. The flat plate shape is particularly preferable from the viewpoint that the glittering particles can be easily aligned in one direction in the coating film, that is, the color and brightness of the coating film can be changed significantly. When the aluminum is flat, the shape of the flat surface is not particularly limited, and any shape such as a circular shape, an elliptical shape, or a polygonal shape may be used.

On the other hand, the reflective layer is a layer formed between aluminum and an iron oxide layer, and is a layer for reflecting light at the interface between aluminum and the reflective layer and / or at the interface between the reflective layer and the iron oxide layer. Is. The reflective layer is preferably a layer containing _{silicon dioxide (SiO 2).} When the reflective layer contains silicon dioxide, the brightness on the highlight side is significantly increased and the range of color change is widened. Whether or not the brilliant particles contain silicon dioxide can be determined by the amount of silicon elements when the brilliant particles are analyzed by an energy dispersive fluorescent X-ray analyzer or the like.

The reflective layer may cover the entire surface of the particulate aluminum, or may cover only a part of the particulate aluminum. However, from the viewpoint of increasing the change in the color and brightness of the obtained coating film, it is preferable that the reflective layer covers substantially the entire surface of the particulate aluminum.

The degree of coverage of the reflective layer can be specified, for example, by the ratio of the amount of elements constituting the reflective layer (here, the amount of silicon element) to the amount of aluminum element in the glittering particles. The amount of silicon element in the glitter particles is preferably 0.05 to 0.5 parts by mass, more preferably 0.08 to 0.4 parts by mass, and 0.1 to 1 part by mass with respect to 1 part by mass of the aluminum element in the glitter particles. 0.3 parts by mass is more preferable. When the amount of silicon element is 0.05 parts by mass or more, the color change and the brightness change of the obtained coating film become sufficiently large. On the other hand, when the amount of silicon element is 0.5 parts by mass or less, the reflective layer does not become excessively thick, and the light reflectivity by the brilliant particles tends to be good.

The iron oxide layer is a layer formed so as to cover the reflective layer, and is a layer containing iron oxide. The iron oxide layer may be formed so as to cover all of the reflective layer and aluminum, or may be formed so as to cover only a part of the iron oxide layer. However, from the viewpoint of making the color of the glittering particles uniform, it is preferable that the iron oxide layer is formed on substantially the entire surface.

The degree of coverage of the bright particles with iron oxide can be specified, for example, by the ratio of the iron elements in the bright particles to the amount of aluminum elements in the bright particles. The amount of iron element in the glitter particles is preferably 0.05 to 4 parts by mass, more preferably 0.10 to 3.5 parts by mass, and 0.15 to 5 parts by mass with respect to 1 part by mass of the aluminum element in the glitter particles. 3.0 parts by mass is more preferable. When the amount of the iron element is 0.05 parts by mass or more, not only the color of the glittering particles becomes a desired color (for example, red or yellow), but also the strength is increased and it becomes difficult to crack when forming the coating film. .. On the other hand, when the amount of the iron element in the brilliant particles is 4 parts by mass or less, the brilliant particles are less likely to settle in the composition for forming the brilliant coating film. The color of the glittering particles can be adjusted by adjusting the amount of iron oxide.

Here, the average particle size of the brilliant particles is preferably 1 to 70 μm, more preferably 5 to 40 μm, and even more preferably 10 to 20 μm. When the average particle size is 1 μm or more, it becomes easy to handle the glittering particles. On the other hand, when the average particle size of the brilliant particles is 70 μm or less, the brilliant particles are less likely to crack during preparation or application of the composition for forming a brilliant coating film. In addition, the coatability of the composition for forming a brilliant coating film is improved.

The average particle size of the glittering particles is specified by observation with a scanning electron microscope. Specifically, the surface of 50 randomly selected brilliant particles is observed with a scanning electron microscope (SEM), and the average value of the particle sizes (maximum diameter) of the 50 particles is taken as the average particle size. In addition, in the brilliant particles, a part of a plurality of particles may be melted or bonded. In this case, the portion corresponding to the particles before melting or bonding is specified, and this is regarded as an approximate particle and the particle size (maximum diameter) is measured. The maximum diameter of the particles may be automatically determined by using image analysis software, or may be determined by measuring the maximum diameter from the obtained SEM image. When measuring the maximum diameter from the obtained SEM image, a straight line connecting arbitrary two points on the outer circumference of the glittering particles in the SEM image is drawn, and the position where the length of the straight line becomes the maximum is specified. Then, the length of the straight line at the relevant portion is measured, and this is set as the maximum diameter of the brilliant particles.

When the glittering particles are flat, the average thickness thereof is preferably 1 to 3,500 nm, more preferably 1 to 2000 nm, and even more preferably 2 to 1000 nm. When the average thickness of the flat brilliant particles is 3500 nm or less, the brilliant particles are likely to be oriented when the composition for forming a brilliant coating film is applied, and the colors on the highlight side and the shade side are different. Changes and brightness changes tend to be large. On the other hand, when the average thickness of the brilliant particles is 1 nm or more, the strength of the brilliant particles increases and it becomes difficult to crack.

The average thickness of the brilliant particles is measured by observing the cross section of 20 brilliant particles with a transmission electron microscope (TEM) and measuring the thickness (average value) thereof. Further, the average value of the thicknesses of the 20 glittering particles is calculated, and this is used as the average thickness.

When the glittering particles are flat, the average particle size with respect to the average thickness, that is, the aspect ratio expressed by the average particle size / average thickness is preferably 20 to 5000, more preferably 25 to 3000, and 30 to 2000. More preferred. When the aspect ratio is 20 or more, the color change and the brightness change of the obtained coating film tend to be large. On the other hand, when the aspect ratio is 5000 or less, the handleability of the glittering particles is good.

The amount of the glittering particles is appropriately selected depending on the use and coating method of the composition for forming a glittering coating film. It is preferably 1 to 60% by mass, preferably 3 to 50% by mass, based on the total solid content of the composition for forming a glittering coating film (the amount of the composition for forming a glittering coating film excluding volatile components such as a solvent). % Is more preferable, and 6 to 40% by mass is further preferable. When the amount of the brilliant particles is in the above range, the color change and the brightness change in the obtained coating film tend to be large.

The method for preparing the brilliant particles is not particularly limited, and the brilliant particles can be formed by a known method. However, it is preferable to form the reflective layer and the iron oxide layer by a wet method. When the reflective layer and the iron oxide layer are formed by a wet method, the reflective layer and the iron oxide layer can be formed with a substantially uniform thickness on the entire aluminum surface, and the glittering particles are less likely to have uneven color or uneven brightness.

Examples of the method for forming the reflective layer by the wet method include the following methods. First, particulate aluminum is dispersed in an organic solvent. Then, an organosilicon compound is added to the dispersion liquid, and the mixture is hydrolyzed and polycondensed to form a reflective layer around the particulate aluminum. The organosilicon compound may be any compound that becomes silicon dioxide by hydrolysis and polycondensation, and examples thereof include tetraalkoxysilane. The number of carbon atoms contained in each alkoxy group of tetraalkoxysilane is preferably 1 to 4, and specific examples of tetraalkoxysilane include tetraethoxysilane and the like.

Further, the hydrolysis and polycondensation of the organosilicon compound are preferably carried out in the presence of a catalyst such as a base or an acid. Examples of catalysts include sodium hydroxide solution, aqueous ammonia solution, phosphoric acid, acetic acid, oxalic acid and the like.

Further, the hydrolysis and polycondensation of the organosilicon compound are preferably carried out while heating at 40 to 80 ° C., and at this time, it is preferable to gradually heat the organosilicon compound over 10 to 48 hours. After forming a reflective layer around the particulate aluminum, it may be washed or dried as needed. The amount of the above-mentioned silicon element, that is, the thickness of the reflective layer is adjusted by the amount of the organosilicon compound added and the time of hydrolysis and polycondensation.

On the other hand, as a method for forming the iron oxide layer by the wet method, the following methods can be mentioned. The aluminum coated by the reflective layer is dispersed in an organic solvent. Then, an iron compound is added to the dispersion and hydrolyzed. As a result, an iron oxide layer is further formed around the reflective layer. Examples of iron compounds include inorganic salts such as iron nitrate, iron sulfate, and iron chloride; and organic salts such as iron acetate, iron formate, iron citrate, iron acetylacetonate, and ferrocene. The amount of iron element, that is, the thickness of the iron oxide layer and the color of the glittering particles can be adjusted by the amount of the iron compound added and the reaction time.

(2) Coloring Pigment The coloring pigment is a pigment for coloring a coating film, and the color of the coloring pigment is preferably a color significantly different from the color of the above-mentioned glitter particles. As mentioned above, the glittering particles are usually red to yellow. Therefore, the coloring pigment preferably contains a blue pigment, a white pigment, and a green pigment. Examples of blue pigments include organic pigments such as phthalocyanine pigments, quinacridone pigments, dioxazine pigments and perylene pigments; composite oxides such as bismuth vanadium oxide and inorganic pigments such as ultramarine blue and cobalt blue. The coloring pigment may contain only one type of blue pigment, or may contain two or more types. Among these, cobalt blue and phthalocyanine pigments are preferable from the viewpoint of colorability and transparency, and phthalocyanine pigments are more preferable.

Examples of white pigments include titanium oxide, zinc oxide, zinc carbonate, zinc sulfide, lithopone, lead sulfate, white lead, antimony oxide, aluminum nitride, boron nitride, zirconium oxide and the like.

Examples of green pigments include C.I. I. Pigment green (hereinafter, also referred to as “PG”) 36, PG7, PG58 and other phthalocyanine greens and the like are included.

Here, the coloring pigment may contain only one color pigment such as a blue pigment, a white pigment, and a green pigment, but it is preferable to combine, for example, a blue pigment, a green pigment, or the like with a pigment having high brightness. .. In particular, when a blue pigment, a green pigment, or the like is combined with a white pigment, the color change of the coating film tends to be large. The reason is not clear, but if the coating film contains a pigment with high lightness (white pigment, etc.), the color derived from the pigment becomes more vivid and easy to see even on the shade side, and from the highlight side to the shade side, the coating film It is thought that the color change will be large.

When the white pigment is combined with a blue pigment or a green pigment, the content of the white pigment with respect to 1 part by mass of the total amount of the coloring pigment is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and 0. 3 parts by mass or more is more preferable, and 0.5 parts by mass or more is particularly preferable. The content of the white pigment with respect to 1 part by mass of the total amount of the coloring pigment is preferably 0.99 parts by mass or less, more preferably 0.98 parts by mass or less, and further preferably 0.97 parts by mass or less. ^{When the amount of the white pigment is in the above range, the L *} value on the shade side and the highlight side of the coating film tends to fall within the above range.

The coloring pigment may contain a pigment other than a blue pigment, a white pigment, and a green pigment. Examples of pigments other than the above include organic pigments such as azo pigments and isoindolinone pigments; and inorganic pigments such as composite oxides, petals, and tan. The coloring pigment may contain only one kind of these, or may contain two or more kinds of these.

Here, the average primary particle size of the coloring pigment is preferably 0.01 to 2 μm, more preferably 0.01 to 1.5 μm, and even more preferably 0.02 to 1 μm. When the average primary particle size of the coloring pigment is 0.01 μm or more, the handleability is improved. On the other hand, when the average primary particle size of the coloring pigment is 2 μm or less, the color of the obtained coating film is unlikely to be uneven. The average primary particle size of the coloring pigment is specified by observation with a transmission electron microscope (TEM). Specifically, the primary particle diameters (maximum diameters) of 50 coloring pigments randomly selected by a transmission electron microscope (TEM) are measured, and the average value of the primary particle diameters of the 50 coloring pigments is the average primary grain size. Adopted as the diameter. The maximum diameter of the particles may be automatically determined by using image analysis software, or may be determined by measuring the maximum diameter from the obtained TEM image. The method of measuring the maximum diameter from the TEM image is the same as the method of obtaining the maximum diameter of the brilliant particles described above from the SEM image.

On the other hand, the average dispersed particle size of the coloring pigment is preferably 2 μm or less, more preferably 0.01 to 1 μm, and even more preferably 0.05 to 0.5 μm. The average dispersed particle size is the particle size (secondary particle size) of the coloring pigment in the composition for forming a bright coating film. If the average dispersed particle size is excessively large, the hiding property is enhanced, and it becomes difficult to confirm the color and brightness of the glittering particles. When the average dispersed particle size is 2 μm or less, it is difficult to conceal the brilliant particles, and a high design property that makes the best use of the brilliant particles can be obtained. The average dispersed particle size is measured as follows. It is obtained by diluting (dispersing) a dispersion containing each coloring pigment or a dispersion so that the pigment content is 0.1% by mass, and performing dynamic light scattering measurement at 25 ° C. The measurement can be performed by, for example, a Zetasizer Nano ZS manufactured by Malvern. Then, a cumulant analysis (ISO13321) is performed from the light intensity distribution, and the obtained Z-Average value is used as the average dispersed particle size.

The amount of the coloring pigment contained in the composition for forming a brilliant coating film is appropriately selected according to the use of the composition for forming a brilliant coating film, a desired color, and the like. The amount of the coloring pigment is preferably 0.1 to 10% by mass, more preferably 0.3 to 5% by mass, and 0.4 to 3% by mass with respect to the total solid content of the composition for forming a brilliant coating film. Is even more preferable. When the amount of the coloring pigment is in the above range, the color change and the brightness change in the obtained coating film tend to be large.

The ratio of the amount of the coloring pigment to the amount of the bright particles in the composition for forming a bright coating film, that is, (amount of the coloring pigment) / (amount of the bright particles) is preferably 0.01 to 2. 0.02 to 1 is more preferable, and 0.03 to 0.8 is even more preferable. When the ratio of the amount of the coloring pigment to the amount of the brilliant particles is in the above range, the color change and the brightness change of the obtained coating film tend to be large.

(3) Coating Film Forming Component The composition for forming a brilliant coating film usually contains a coating film forming component for binding the brilliant particles and a coloring pigment to an object to be coated. The coating film-forming component contains a main agent that is a base of the coating film, and may further contain a curing agent for curing the main agent. In the present specification, the main agent means a curable resin such as a thermosetting resin, and the curing agent means a compound for curing the main agent (curable resin). Among them, a thermosetting resin is preferable as the main agent from the viewpoint of easily forming a coating film and enhancing the storage stability of the composition for forming a brilliant coating film.

Examples of the thermosetting resin include known (meth) acrylic resins, polyester resins, alkyd resins, polyurethane resins, etc., and the composition for forming a brilliant coating film may contain only one of these. , Two or more types may be included.

Further, in particular, a (meth) acrylic resin or a polyester resin is preferable among the thermosetting resins, and a (meth) acrylic resin is more preferable, from the viewpoint of easily suppressing the precipitation of bright particles and coloring pigments.

Examples of the (meth) acrylic resin include a polymer of a (meth) acrylic acid ester-based monomer, a copolymer of a (meth) acrylic acid ester-based monomer and another ethylenically unsaturated monomer, and the like. As used herein, the term (meth) acrylic refers to methacryl and / or acrylic. Further, the (meth) acrylic acid ester-based monomer and other ethylenically unsaturated monomers may have a functional group capable of reacting with a curing agent described later. Examples of functional groups that can react with the curing agent described below include hydroxyl groups, carboxyl groups, isocyanate groups, glycidyl groups, amino groups and the like.

Examples of (meth) acrylic acid ester-based monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, ter-butyl (meth) acrylate, and 2-ethylhexyl. (Meta) acrylate, isodecyl (meth) acrylate, n-lauryl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, n-stearyl (meth) acrylate, butoxydiethylene glycol (meth) acrylate, methoxypolyethylene glycol ( Meta) acrylate, methoxypolyethylene glycol (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate , Monofunctional (meth) acrylic acid ester-based monomers such as trifluoroethyl (meth) acrylate; diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1, 4-Butandiol di (meth) acrylate, neopentylglucol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, glycerindi (meth) acrylate , EO adduct di (meth) acrylate of bisphenol A, polyfunctional (meth) acrylic acid ester-based monomers such as trimethylpropantri (meth) acrylate and the like are included. When the (meth) acrylic resin is a polymer of a (meth) acrylic acid ester-based monomer, it may be a homopolymer thereof or a copolymer.

Examples of (meth) acrylic acid ester-based monomers having a functional group capable of reacting with a curing agent include monomers having a hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2 -Hydroxybutyl (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate and the like are included.

Further, examples of the ethylenically unsaturated monomer copolymerized with the above (meth) acrylic acid ester-based monomer include styrene-based monomers such as styrene and α-methylstyrene; vinyl-based monomers such as vinyl acetate and vinyl propionate. included.

Examples of ethylenically unsaturated monomers include monomers having a carboxyl group that can react with a curing agent, and examples thereof include unsaturated carboxylic acids such as (meth) acrylic acid, itaconic acid, maleic acid, and fumaric acid. Contains acid monomers and the like.

The amount of the main agent contained in the composition for forming a brilliant coating film depends on the use and coating method of the composition for forming a brilliant coating film, the desired viscosity, the amount of functional groups contained in the main agent, the amount of a curing agent, and the like. Is selected as appropriate. The amount of the main agent is preferably 20 to 95% by mass, more preferably 30 to 90% by mass, still more preferably 40 to 85% by mass, based on the total solid content of the composition for forming a brilliant coating film. When the amount of the main agent is 20% by mass or more, the glittering particles and the coloring pigment are likely to be bound to the object to be coated. On the other hand, when the amount of the main agent is 95% by mass or less, the amount of the brilliant particles and the coloring pigment is relatively sufficient, and the color change and the brightness change tend to be large in the obtained coating film.

On the other hand, the type of curing agent is appropriately selected according to the type of functional group contained in the main agent. Examples of the curing agent include amino resins, polyisocyanate compounds, blocked polyisocyanate compounds, epoxy group-containing compounds, carboxyl group-containing compounds, carbodiimide group-containing compounds, hydrazide group-containing compounds, semi-carbazide group-containing compounds and the like. The composition for forming a brilliant coating film may contain only one kind of these, or may contain two or more kinds of these.

When the main agent has a hydroxyl group, the curing agent is preferably an amino resin, a polyisocyanate compound, or a blocked polyisocyanate compound. On the other hand, when the main agent contains a carboxyl group, the curing agent is preferably a carbodiimide group-containing compound.

The amount of the curing agent is preferably 0.05 to 0.5 parts by mass, more preferably 0.1 to 0.4 parts by mass with respect to 1 part by mass of the main agent. When the amount of the curing agent is in the above range, the curability of the composition for forming a brilliant coating film becomes good.

(4) Fatty Acid Amide Compound The composition for forming a brilliant coating film preferably further contains a fatty acid amide compound. The fatty acid amide-based compound forms a network by hydrogen-bonding the fatty acid amide-based compounds to each other in the composition for forming a bright coating film, and interacts with the bright particles. Therefore, the dispersibility of the bright particles in the composition for forming a bright coating film is improved, and the storage stability is further improved. Further, since the bright particles are supported by the network structure, the composition for forming a bright coating film is less likely to be deteriorated over time. Further, the fatty acid amide compound does not easily affect the color and brightness of the coating film when the coating film is formed. The fatty acid amide compound may be a small molecule compound, an oligomer, a polymer, or the like.

Examples of fatty acid amide compounds include saturated fatty acid monoamides such as lauric acid amide, stearic acid amide, palmitic acid amide, caproic acid amide, capric acid amide, capric acid amide, myristic acid amide, behenic acid amide, and hydroxystearic acid amide. Saturated fatty acid monoamides such as oleic acid amides, erucic acid amides, ricinolic acid amides, brassic acid amides, esylate amides, linoleic acid amides, linolenic acid amides, rice sugar fatty acid amides, coconut fatty acid amides; Ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bisisostearic acid amide, ethylene bishydroxystearic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbechenic acid amide, hexamethylene bisstearic stearate Acid amide, N, N'-distearyl adipate amide, N, N'-distearyl sebacic acid amide, methylene bispalmitic acid amide, ethylene bispalmitic acid amide, methylene bisbechenic acid amide, ethylene bisbechenic acid amide, hexa Saturated fatty acid bisamides such as ethylene bispalmitic acid amide; unsaturated fatty acids such as ethylene bisoleic acid amides, hexamethylene bisoleic acid amides, N, N'-diorail adipic acid amides, N, N'-diorail sebacic acid amides, etc. Fatty acid bisamide; substitutional amides such as N-stearyl stealic acid amide, N-oleyl oleic acid amide, N-stearyl oleic acid amide, N-oleyl stealic acid amide, N-stearyl erucate amide, N-oleyl palmitate amide; N , N'-Aromatic bisamides such as distearylisophthalic acid amides, metaxylylene bisstearic acid amides; N, N'-2-hydroxyethylstearic acid amides, N, N'-ethylenebisoleic acid amides, N, N Branched amides such as'-xylene bisstearic acid amide, N, N'-diorail adipic acid amide, N, N'-diorail sebacic acid amide, N, N'-dystearyl isophthalic acid amide; palm oil fatty acid mono Ethanolamide, laurate monoethanolamide, myristic acid monoethanolamide, oleic acid monoethanolamide, coconut oil fatty acid diethanolamide, laurate diethanolamide, myristic acid diethanolamide, oleate diethanolamide, Alkanol amides such as coconut oil fatty acid monopropanol amide, lauric acid monopropanol amide, myristic acid monopropanol amide, oleic acid monopropanol amide, and polyoxyalkylene alkanol amide; are included.

As the fatty acid amide compound, a commercially available product may be used. Specific examples of commercially available products include Disparon 6300, Disparon 6500, Disparon 6600, Disparon 6650, Disparon 6700, Disparon 6900-10X, Disparon 6900-20X, Disparon 6810-20X, Disparon 6820-10X, Disparon 6820-20X, Disparon 6820-20X. -20X, Disparon F-9050, Disparon FS-6010, Disparon PFA-220, Disparon PFA-231, Disparon PFA-131, Disparon A603-10X, Disparon A603-20X, Disparon A650-20X, Disparon A670-20M, Disparon A670-20M -EZ, Disparon NS-5010, Disparon NS-5025, Disparon NS-5810, Disparon NS-5210, Disparon NS-5310 (all manufactured by Kusumoto Kasei Co., Ltd., Disparon is a registered trademark of the same company); Taren 7200-20, Tarren 8200 -20, Talen 8300-20, Talen 8700-20, Talen BA-600, Talen RCM-220, Talen M-1020XFS, Talen M-1021B, Floren RCM-210, Floren SP-1000, Floren SP-1000, Floren SP -1000AF, Floren RCM-230AF, Floren SH-290, Floren SH-295S, Floren SH-350, Floren HR-2, Floren HR-2G, Floren HR-4AF (all manufactured by Kyoei Chemical Co., Ltd.) and the like are included.

The amount of the fatty acid amide compound contained in the composition for forming a brilliant coating film is appropriately selected according to the use of the composition for forming a brilliant coating film, the coating method, the desired viscosity, and the like. The amount of the fatty acid amide compound is preferably 0.1 to 10% by mass, more preferably 0.3 to 5% by mass, and 0.5 to 3 with respect to the total solid content of the composition for forming a brilliant coating film. Mass% is more preferred. When the amount of the fatty acid amide compound is 0.1% by mass or more, a network of the fatty acid amide compounds is sufficiently formed in the composition for forming a bright coating film, and the dispersibility of the bright particles is enhanced. On the other hand, when the amount of the coating film forming component is 10% by mass or less, the brightness and color of the obtained coating film are likely to change.

(5) Other Components The composition for forming a brilliant coating film may contain components other than the above, if necessary. Examples of other components include solvents and various additives.

The type of solvent is not limited as long as it can uniformly disperse or dissolve the above-mentioned bright particles, coloring pigments, coating film-forming components and the like. Examples of solvents include hydrocarbons such as toluene and xylene; esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, ethylene glycol monomethyl ether acetate and butyl carbitol acetate; n-butyl ether, dioxane and ethylene glycol monomethyl. Ethers such as ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone; methanol, ethanol, isopropanol, n-butanol, sec-butanol, isobutanol, etc. Alcohols; ethers such as n-butyl ether, dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether; aromatic petroleum; etc. are included. The composition for forming a brilliant coating film may contain only one kind of these, or may contain two or more kinds of these. The amount of the solvent is appropriately selected according to the viscosity of the composition for forming a brilliant coating film and the like.

Examples of other components include known dispersants; benzotriazole-based absorbers, triazine-based absorbers, and ultraviolet absorbers such as salicylic acid derivative-based absorbers, benzophenone-based absorbers; light stabilizers such as hindered amines; A viscous agent; a defoaming agent; a surface conditioner; an anti-precipitation agent other than the above-mentioned fatty acid amide compound; a rust preventive agent; a chelating agent such as acetylacetone; a dehydrating agent; a plasticizing agent; and the like are included. These amounts are not particularly limited as long as they do not impair the object and effect of the present invention.

(6) Method for preparing a composition for forming a brilliant coating film The method for preparing a composition for forming a brilliant coating film is not particularly limited, and each of the above components may be mixed. However, when the coating film-forming component contains a main agent and a curing agent, a main agent-containing composition containing a coating film-forming component, bright particles, a coloring pigment, a solvent, etc., and a curing agent-containing composition containing a curing agent and a solvent. May be prepared separately to form a two-component type. When the composition for forming a brilliant coating film is a two-component type, the main agent-containing composition and the curing agent-containing composition are mixed at an appropriate timing such as immediately before coating.

The viscosity of the composition for forming a brilliant coating film is appropriately selected according to its application (coating method). For example, when the composition for forming a brilliant coating film is used as a composition for a paint (for example, when it is applied by spraying), it is measured with a B-type viscometer of the composition for forming a brilliant coating film at 23 ° C. and 60 rpm. The viscosity is preferably 100 to 800 mPa · s, more preferably 200 to 450 mPa · s.

On the other hand, when the composition for forming a brilliant coating film is used as a composition for ink (for example, when it is applied by screen printing), a B-type viscometer of the composition for forming a brilliant coating film is used at 23 ° C. and 20 rpm. The measured viscosity is preferably 600 to 3000 mPa · s, more preferably 1000 to 4000 mPa · s. When the viscosity of the composition for forming a brilliant coating film is in the above range, it becomes easy to apply by each method, and further, after application, the brilliant particles tend to be oriented in one direction. As a result, the change in brightness and the change in color become large from the shade to the highlight of the obtained coating film.

(7) Coating Film The composition for forming a brilliant coating film can be applied to an object to be coated by various known methods. The composition for forming a brilliant coating film may be, for example, a coating composition used for coating such as a spray coating method, an electrostatic coating method, a curtain coating coating method, a spin coating coating method, and a dipping coating method. Among these coating methods, a spray coating method, a curtain coat coating method, and a dipping coating method are preferable.

The composition for forming a brilliant coating film may be an ink composition used for printing such as a gravure printing method, a screen printing method, a gravure offset printing method, a flexographic printing method, and an inkjet printing method. Among these printing methods, a screen printing method and a gravure offset printing method are preferable.

After coating the composition for forming a brilliant coating film by the above coating method or printing method, heating or the like is performed as necessary to remove the solvent or the like in the composition for forming a brilliant coating film, or to form a brilliant coating film. By cross-linking the main agent in the composition for use, the composition for forming a brilliant coating film is cured.

The thickness of the coating film is appropriately selected according to the intended use, and the dry film thickness can be, for example, 1 to 200 μm.

The shape of the object to be coated of the composition for forming a brilliant coating film is not particularly limited, and may be a flat plate shape or a three-dimensional shape. The material of the object to be coated is also not particularly limited as long as it is a material that is not eroded by the above-mentioned composition for forming a brilliant coating film. Examples include metals such as iron, copper and aluminum and their alloys; various resins such as epoxy resins, polyethylene resins, polypropylene resins, polyamide resins and polyurethane resins; inorganic substances such as glass, cement and concrete; wood, fibers and the like. Includes natural or synthetic materials.

The use of the article coated with the composition for forming a brilliant coating film of the present invention is not particularly limited, and examples thereof include vehicles such as automobiles, airplanes, and ships; building materials; electronic / electrical / OA equipment; and miscellaneous goods. Etc., various fields are included.

Hereinafter, specific examples of the present invention will be described. It should be noted that these examples do not limit the scope of the present invention.

1. 1. Material [Glittering particles]
As the brilliant particles, the following brilliant particles 1 to 5, a commercially available colored aluminum pigment, or a commercially available aluminum paste were used.
・ Glitter particle 1: Prepared by the following synthesis method ・ Glitter particle 2: Prepared by the following synthesis method ・ Glitter particle 3: Prepared by the following synthesis method ・ Glitter particle 4: Prepared by the following synthesis method ・ Glitter Sex particles 5: Prepared by the following synthetic method ・ Colored aluminum pigment: FriendColor D111 RE (manufactured by Toyo Aluminum Co., Ltd., mineral spirit dispersion, average particle size 23 μm, average thickness: 140 nm, aspect ratio: 13.1, solid content 55 mass %)
-Aluminum paste: 6360NS (manufactured by Toyo Aluminum K.K., average particle size 10 μm, average thickness 250 nm, aspect ratio: 40, solid content 69% by mass)
The composition, average particle size, and average thickness of each glittering particle were specified as follows.

(Method of specifying the composition of glittering particles)
The amount of the element aluminum (Al), the amount of the element silicon (Si), and the amount of the iron element (Fe) were calculated by an energy dispersive fluorescent X-ray analyzer (EDX-720 manufactured by Shimadzu Corporation). Specifically, C (carbon) was set as a balance element (component), and the contents of aluminum element, silicon element and iron element were quantified by quantitative analysis by the fundamental parameter method (FP method).

(Measuring method of average particle size and average thickness of brilliant particles)
The average particle size (primary particle size) of the glittering particles was specified by observation with a scanning electron microscope (SEM). Specifically, the surfaces of 50 randomly selected brilliant particles were observed with a scanning electron microscope, and the average value of the particle sizes (maximum diameters) of the 50 particles was taken as the average particle size. The brilliant particles may be partially melted or powder particles may be connected to each other. In this case, the portion corresponding to the particles before melting or bonding was identified, and this was regarded as an approximate particle and the particle size was measured. Further, the maximum diameter was obtained by measuring the maximum diameter from the SEM image. Specifically, a straight line connecting arbitrary two points on the outer circumference of the glittering particles in the SEM image was drawn, and the position where the length of the straight line became the maximum was specified. Then, the length of the straight line at the relevant portion was measured, and this was taken as the maximum diameter of the brilliant particles.

(Method for synthesizing brilliant particles 1)
To a round flask equipped with a reflux shrinker and a stirrer, 200 parts by mass of flat aluminum flakes (average particle size 20 μm, average thickness 600 nm) and 1500 parts by mass of isopropanol were added and stirred. Next, 600 parts by mass of water and 40 parts by mass of 25% by mass aqueous ammonia were added to the round flask and heated to 60 ° C. with stirring. Then, a mixed solution of 300 parts by mass of isopropanol and 300 parts by mass of tetraethoxysilane was added dropwise over 10 hours. Then, the mixture was stirred at 55 ° C. for 14 hours to obtain a suspension containing an aluminum powder coated with silicon dioxide. After cooling the suspension, it was filtered, washed with isopropanol, and dried in a dryer at 80 ° C. to obtain a silicon dioxide-coated aluminum powder.

75 parts by mass of the obtained silicon dioxide-coated aluminum powder was dispersed in 700 parts by mass of water, and the pH was adjusted to about 3. A 50% aqueous iron nitrate solution and an aqueous NaOH solution were added thereto, and the mixture was stirred while keeping the pH constant. When the obtained suspension turned red, the addition of the iron nitrate aqueous solution and the NaOH aqueous solution was stopped. The obtained suspension was filtered, washed with isopropanol, and dried in a dryer at 80 ° C. to obtain glittering particles 1 (iron oxide-coated aluminum particles). The average particle size of the obtained glitter particles 1 was 23 μm, and the average thickness was 1000 nm. In the glittering particles 1, the amount of silicon element per 1 part by mass of aluminum element was 0.14 part by mass, and the amount of iron element was 1.57 part by mass.

(Method for synthesizing glittering particles 2)
A silicon dioxide-coated aluminum powder was obtained in the same manner as in the method for synthesizing the glittering particles 1 described above. Then, 75 parts by mass of the silicon dioxide-coated aluminum powder was dispersed in 700 parts by mass of water, and the pH was adjusted to about 3. A 50% aqueous iron nitrate solution and an aqueous NaOH solution were added thereto, and the mixture was stirred while keeping the pH constant. When the obtained suspension turned yellow, the addition of the iron nitrate aqueous solution and the NaOH aqueous solution was stopped. Then, the same treatment as the method for synthesizing the glittering particles 1 was carried out to obtain the glittering particles 2 (iron oxide-coated aluminum particles). The brilliant particles 2 had an average particle size of 21 μm and an average thickness of 700 nm. Further, in the glittering particles 2, the amount of silicon element per 1 part by mass of aluminum element was 0.15 part by mass, and the amount of iron element was 0.61 part by mass.

(Method for synthesizing glittering particles 3)
A silicon dioxide-coated aluminum powder was obtained in the same manner as in the method for synthesizing the glittering particles 1 described above. Then, 75 parts by mass of the silicon dioxide-coated aluminum powder was dispersed in 700 parts by mass of water, and the pH was adjusted to about 3. A 50% aqueous iron nitrate solution and an aqueous NaOH solution were added thereto, and the mixture was stirred while keeping the pH constant. When the obtained suspension turned orange, the addition of the iron nitrate aqueous solution and the NaOH aqueous solution was stopped. Then, the same treatment as the method for synthesizing the glittering particles 1 was carried out to obtain the glittering particles 3 (iron oxide-coated aluminum particles). The brilliant particles 3 had an average particle size of 21 μm and an average thickness of 800 nm. Further, in the glittering particles 3, the amount of silicon element per 1 part by mass of aluminum element was 0.16 part by mass, and the amount of iron element was 1.17 part by mass.

(Method for synthesizing glittering particles 4)
The above-mentioned glitter particles 1 except that a mixed solution of 1600 parts by mass of isopropanol and 400 parts by mass of tetraethoxysilane was added dropwise over 10 hours using flat aluminum flakes (average particle size 20 μm, average thickness 210 μm). Glittering particles 4 (iron oxide-coated aluminum particles) were obtained in the same manner as in the synthesis method of. The brilliant particles 4 had an average particle size of 24 μm and an average thickness of 300 nm. Further, in the glittering particles 4, the amount of silicon element per 1 part by mass of aluminum element was 0.21 part by mass, and the amount of iron element was 1.56 part by mass.

(Method for synthesizing glittering particles 5)
Aluminum flakes and pentacarbonyl iron (Fe (CO) ₅ ) were reacted using a fluidized bed reactor. Specifically, 1500 g of aluminum flakes having an average particle size of 15 μm was charged into the reaction vessel of the fluidized bed reactor from the aluminum supply section installed at the upper part of the reaction vessel. Then, nitrogen gas was supplied at 1000 L / hour from a gas supply unit installed at the bottom of the reaction vessel, and the aluminum flakes were heated to 200 ° C. while flowing in the reaction vessel. Then, nitrogen and air were supplied from the gas supply unit so that the oxygen concentration in the reaction vessel was 2.5% by volume.

_{After that, 1665 ml of pentacarbonyl iron (Fe (CO) 5} ) is preheated and vaporized from the raw material gas supply unit provided near the central portion in the height direction of the reaction vessel, and is vaporized together with nitrogen gas at 200 L / hour for 35 hours. It was continuously supplied into the reaction vessel. As a result, pentacarbonyl iron (Fe (CO) ₅ ) was decomposed in the reaction vessel, and iron oxide (III) was precipitated on the surface of the aluminum flakes. The obtained glitter particles 5 (iron oxide-coated aluminum particles) had an average particle size of 16 μm and an average thickness of 300 nm. Further, in the glittering particles 5, the amount of iron element per 1 part by mass of the amount of aluminum element was 1.6 parts by mass, and the silicon element was not detected.

[Coloring pigment]
The following commercially available coloring pigments were used as the coloring pigments.
Blue pigment 1: Copper phthalocyanine dispersion (NCP-CZ9664BLUE manufactured by Nikko Bics, copper phthalocyanine blue content 5-10%, average dispersion particle size 248 nm)
-White pigment: Titanium dioxide dispersion (NCP-CZ051WHITE manufactured by Nikko Bics, titanium oxide content 12.5 to 17.5%, average dispersion particle size 187 nm)
-Green pigment: Copper phthalocyanine green dispersion (NCP-CZ405GREEN manufactured by Nikko Bics, copper phthalocyanine green content 7.5 to 12.5%, average dispersion particle size 309 nm)
-Blue pigment 2: Copper phthalocyanine blue dispersion (NCP-CZ9650BLUE manufactured by Nikko Bics, copper phthalocyanine blue content 12.5 to 17.5%, average dispersion particle size 192 nm)
-Yellow pigment: Isoindoline yellow dispersion (NCP-CZ306YELLOW manufactured by Nikko Bics, isoindoline yellow content 7.5 to 12.5%, average dispersion particle size 136 nm)
-Purple pigment: quinacridone violet dispersion (CZ-702, NCP-CZ702VIOLET manufactured by Nikko Bics, quinacridone pigment content 5-10, average dispersion particle size 178 nm)
-Red pigment: Diketopyrrolopyrrole red dispersion (NCP-CZ9102RED manufactured by Nikko Bics, diketopyrrolopyrrole pigment content 5-10, average dispersion particle size 272 nm)
-Brown pigment: Iron oxide brown dispersion (NCP-CZ9504BROWN manufactured by Nikko Bics, iron oxide content 5-10%, average dispersion particle size 284 nm)
The average dispersed particle size of each coloring pigment was determined by the following method.

-Method for measuring the average particle size of colored pigments A dispersion or dispersion containing each colored pigment is diluted (dispersed) so that the pigment content is 0.1% by mass, and dynamic light scattering is measured at 25 ° C. Asked by doing. The measurement was performed by a Zetasizer Nano ZS manufactured by Malvern. At this time, a cumulant analysis (ISO13321) was performed from the light intensity distribution, and the obtained Z-Average value was taken as the average dispersed particle size.

[Additive]
The following commercially available products were used as additives.
-Fatty acid amide wax ((fatty acid amide compound) manufactured by Kusumoto Kasei Co., Ltd., Disparon (registered trademark) PFA-220 (solid content: 20% by mass))
-Higher fatty acid amide ((fatty acid amide compound) manufactured by Kyoei Chemical Co., Ltd., Tarlen M-1020XFS (solid content: 20% by mass))
・ Sepiolite (manufactured by Torsa, PANGEL B20)
・ Organic bentonite (manufactured by Hojun, Esben)

2. Preparation of paint composition A
[Example 1]
(1) Preparation of (Meta) Acrylic Resin a (Main Agent) 100 parts by mass of butyl acetate was placed in a flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas introduction tube, and the temperature was raised to 120 ° C. Then, while stirring butyl acetate in the flask with a stirrer, 60 parts by mass of methyl methacrylate, 29.5 parts by mass of butyl acrylate, 8 parts by mass of -2-hydroxyethyl methacrylate, 0.5 parts by mass of acrylic acid, and A mixed solution consisting of 2 parts by mass of 1,1-azobis-1-cyclohexanecarbonitrile (manufactured by Wako Pure Chemical Industries, Ltd., V-40) was added dropwise over 2 hours. After completion of the dropping, the mixture was further stirred at 120 ° C. for 4 hours to react the remaining monomers. Then, the heating was stopped and the mixture was cooled to room temperature to obtain a dispersion liquid (solid content ratio: 50% by mass) of the (meth) acrylic resin a.

The obtained (meth) acrylic resin a had a number average molecular weight of 6,000 and a weight average molecular weight of 15,000. The glass transition temperature of the (meth) acrylic resin a theoretically calculated from the compounding ratio of the monomers used based on the Fox formula was 39 ° C., and the hydroxyl value was 35 mgKOH / g.

The number average molecular weight and the weight average molecular weight of the (meth) acrylic resin a were measured and calculated by gel permeation chromatography (GPC). The equipment, conditions, etc. used are as follows.
-Equipment used: HLC8220GPC (manufactured by Tosoh)
-Columns used: TSKgel SuperHZM-M, TSKgel GMHXL-H, TSKgel G2500HXL, and TSKgel G5000HXL (all manufactured by Tosoh Corporation)
-Column temperature: 40 ° C
-Standard substance: TSKgel standard polystyrene A1000, A2500, A5000, F1, F2, F4, and F10 (all manufactured by Tosoh Corporation)
-Detector: RI (differential refractometer) detector-Eluent: tetrahydrofuran-Flow velocity: 1 ml / min

(2) Preparation of Main Agent-Containing Composition A A mixture was prepared by mixing 90 parts by mass of the (meth) acrylic resin a and 90 parts by mass of butyl acetate, which are the main agents. Further, 6.7 parts by mass of blue pigment 1 (copper phthalocyanine blue) (0.5 parts by mass of a substantial amount of pigment) and 20 parts by mass of butyl acetate were added to the mixture, and the mixture was stirred with a disper. 0.002 parts by mass of dibutyl tin laurate (manufactured by Sakai Chemical Industry Co., Ltd., TN-12) was mixed with the obtained mixture to prepare a main agent-containing composition A.

(3) Preparation of Curing Agent-Containing Composition A 20 parts by mass of butyl acetate is added to 20 parts by mass of an isocyanate compound (isocyanurate modified hexamethylene diisocyanate: Duranate (registered trademark) TKA-100, manufactured by Asahi Kasei Co., Ltd.) as a curing agent. It was mixed to obtain a curing agent-containing composition A.

(4) Preparation of composition for coating material 206.7 parts by mass of the above-mentioned main agent-containing composition A ((meth) acrylic resin a: 90 parts by mass, 1: 0.5 parts by mass of blue pigment), the above-mentioned curing agent-containing composition 20 parts by mass of the product A (10 parts by mass of the isocyanate compound) and 6 parts by mass of the brilliant particles (brilliant particles 1) were mixed. Then, butyl acetate was further added so that the solid content ratio was 35% by mass to obtain a coating composition (A-1).

[Examples 2 to 12, Comparative Examples 1 to 8]
Other than adjusting the amount or type of the coloring pigment and the amount or type of the bright particles in the main agent-containing composition so that the types and contents of the coloring pigment and the glittering particles are the values shown in Tables 1 to 3. Prepared coating compositions (A-2 to A-20) in the same manner as in Example 1. The amount of the coloring pigment shown in Tables 1 to 3 is not the amount of the dispersion or the dispersion liquid added, but the actual amount of the pigment.

3. 3. Evaluation A
(Preparation of test plate)
The coating compositions prepared in the above Examples and Comparative Examples were applied to standard coated paper (OK Top Coat + manufactured by Oji Paper Co., Ltd.) by air spray so that the dry film thickness was 20 μm. After coating, the mixture was allowed to stand for 24 hours and further dried at 80 ° C. for 60 minutes to obtain a test plate having a coating film having a thickness of 20 μm.

(Evaluation by multi-angle colorimeter)
Visible light was incident on each test plate from a standard light source (SpectraLightQC D65 manufactured by X-rite) at an incident angle of 45 °. Then, when the specular reflection direction is 0 °, the light source side is positive from the specular reflection direction, and the side away from the specular reflection direction is negative, the L ^* a ^* b ^* color system L ^* value emitted in the 75 ° direction. (L ^* _{(75 °)} ), a ^* value (a ^* _{(75 °)} ) and b ^* value (b ^* _{(75 °)} ) were identified by BYK-mac (a multi-angle colorimeter manufactured by BYK Gardner). .. At the same time, the L ^* a ^* b ^* color system L ^* value (L ^* _{(-15 °)} ), a ^* value (a ^* _{(-15 °)} ) and b ^* value ( b ^* _{(-15 °)} ) was also specified. The measurement was repeated three times while changing the incident location of light, and the average value of each value was obtained. From the average value, the hue change index (change in hue) and the color change index (magnitude of color movement) were obtained based on the following formulas.

If the hue change index is designed to be larger than 0.5 and the color change index is larger than 10, the change in the color and brightness of the obtained coating film will be large.

(Visual evaluation (color shift evaluation))
For each of the test plates prepared in Examples and Comparative Examples, it was visually determined whether or not the color and brightness changed under the environment of a standard light source (SpectraLightQC D65 manufactured by X-rite). In making the judgment, the test plate is fixed parallel to the illumination, the test plate is observed from the front direction (highlight side) of the light source, then the observation angle is changed, and the test plate is obliquely oriented (shade side). ). The changes in hue (degree of color shift) and brightness from the highlight side to the shade side at that time were evaluated according to the following criteria.
5: Brightness and hue change significantly from highlight to shade 4: Brightness changes and hue changes significantly from highlight to shade 3: Brightness changes and hue changes from highlight to shade 2: Brightness changes from highlight to shade, but there is little change in hue 1: Brightness changes from highlight to shade, but hue does not change Note that the evaluation is a designer who has been engaged in color development for 3 years or more. A total of 4 people, 5 people and engineers, each evaluated themselves, and the evaluation was decided by a majority vote of 9 people. If the evaluation is 3 or more, there is no problem in practical use.

[result]
^{As shown in Tables 1 to 3 above, a *} _{(75 °) of the} coating film is less than 17 including bright particles in which a reflective layer and an iron oxide layer are formed on aluminum and a coloring pigment. When b ^* _{(75 °)} was set to less than 5 (Examples 1 to 12), the visual color shift evaluation was good. In particular, when the white pigment and the blue pigment were combined, the ^{values of both L *} _{(-15 °)} and L ^* _{(75 °)} became large, and the visual color shift evaluation was even better (Example). 10 and 11). It is considered that the white pigment makes it easier to observe the color derived from the bright particles and the color derived from the coloring pigment (blue pigment) vividly.

On the other hand, even if the brilliant particles and the coloring pigment are contained, if a ^* _{(75 °) of} the coating film is 17 or more or b ^* _{(75 °)} is 5 or more, it is visually observed. The color change was small in the color shift evaluation (Comparative Examples 1 to 4). In these coating films, a color derived from a coloring pigment was observed on the shade side. Further, when a ^* _{(75 °) of} the coating film is 17 or more, or b ^* _{(75 °)} is 5 or more, even if both the hue change index and the color change index are designed to be large, the color change is visually evaluated. Has become smaller. Since the reflected light is observed from different pigments (particles) depending on the observation angle, the change in the discoloration index and the hue change index becomes large even if the coloring pigment and the brilliant particles have similar colors. However, it is considered that the color change was small on the shade side and the highlight side visually because the color pigment and the brilliant particles had similar hues.

On the other hand, when bright particles having no reflective layer between the aluminum and the iron oxide layer are used, the a ^* _{(75 °)} of the coating film is less than 17, and the b ^* _{(75 °)} is Even if it was less than 5, there was little change in brightness in the visual color shift evaluation (Comparative Example 5). It is presumed that the bright particles having no reflective layer were less likely to reflect light than the bright particles having a reflective layer.

Further, when the luminous particles did not have not only the reflective layer but also the iron oxide layer, the a ^* _{(75 °)} of the coating film was less than 17, and the b ^* _{(75 °)} was less than 5. Even so, there was little change in brightness in the visual color shift evaluation (Comparative Examples 6 and 7).

Further, when the bright particles were not contained (Comparative Example 8), the color shift evaluation was low. Furthermore, when a colored aluminum pigment having no iron oxide layer as well as a reflective layer is used as the brilliant particles (Comparative Example 9), the b ^* _{(75 °) of the} coating film is 5 or more, and the color shift evaluation is also low. rice field.

4. Preparation of composition for ink B
[Example 13]
(1) Preparation of (meth) acrylic resin b (main agent) High solve EDE (diethylene glycol diethyl ether manufactured by Toho Chemical Industry Co., Ltd.) is placed in a flask equipped with a stirrer, a thermometer, a reflux cooling device and a nitrogen gas introduction tube. It was charged in parts by mass and the temperature was raised to 90 ° C. Then, while stirring the solvent in the flask with a stirrer, 60 parts by mass of methyl methacrylate, 29.5 parts by mass of butyl acrylate, 8 parts by mass of -2-hydroxyethyl methacrylate, 0.5 parts by mass of acrylic acid, and 2 , 2'-Azobis (2-methylbutyronitrile)) (ABN-E, manufactured by Japan Finechem Company, Inc.) 1.2 parts by mass of a mixed solution was added dropwise over 2 hours. After completion of the dropping, the mixture was further stirred at 90 ° C. for 4 hours to react the remaining monomers. Then, the heating was stopped and the mixture was cooled to room temperature. A dispersion liquid of the (meth) acrylic resin b (solid content ratio: 60% by mass) was obtained.

The obtained (meth) acrylic resin b had a number average molecular weight of 15,000 and a weight average molecular weight of 21,000. The glass transition temperature of the (meth) acrylic resin b theoretically calculated from the compounding ratio of the monomers used based on the Fox formula was 39 ° C., and the hydroxyl value was 35 mgKOH / g. The number average molecular weight and the weight average molecular weight of the (meth) acrylic resin b were measured and calculated by gel permeation chromatography (GPC) in the same manner as in the (meth) acrylic resin a.

(2) Preparation of Main Agent-Containing Composition B 150 parts by mass (solid content: 90 parts by mass) of (meth) acrylic resin b, which is the main agent, and 13.3 parts by mass of blue pigment 1 (copper phthalocyanine blue) (substantial pigment) (0.5 parts by mass) was mixed and stirred. 0.002 parts by mass of dibutyl tin laurate (manufactured by Sakai Chemical Industry Co., Ltd., TN-12) was mixed with the obtained mixture to prepare a main agent-containing composition B.

(3) Preparation of Curing Agent-Containing Composition B 20 parts by mass of diethylene glycol diethyl ether in 20 parts by mass of an isocyanate compound (isocyanurate modified hexamethylene diisocyanate: Duranate (registered trademark) TKA-100, manufactured by Asahi Kasei Co., Ltd.) as a curing agent. Was mixed to obtain a curing agent-containing composition B.

(4) Preparation of composition for ink Main agent-containing composition B163.3 parts by mass ((meth) acrylic resin b: 90 parts by mass, blue pigment 1: 1 parts by mass) and curing agent-containing composition B20 parts by mass (isocyanate compound) : 10 parts by mass) and 12 parts by mass of brilliant particles (brilliant particles 1) are mixed, and diethylene glycol diethyl ether is further added so that the solid content ratio becomes 50% by mass, and the composition for ink (screen ink composition). (A-21) was obtained.

[Example 14 and Example 15]
Except that the amount or type of the coloring pigment in the main agent-containing composition B and the amount or type of the glittering particles were adjusted so that the types and contents of the coloring pigment and the glittering particles were the values shown in Table 4. Ink compositions (A-22 and A-23) were prepared in the same manner as in Example 13. The amount of the coloring pigment shown in Table 4 is not the amount of the dispersion or the dispersion liquid added, but the actual amount of the pigment.

5. Evaluation B
(Preparation of test plate)
The above composition for ink was printed on standard coated paper (OK Top Coat + manufactured by Oji Paper Co., Ltd.) using a # 100 mesh screen (printing pattern 100 mm × 100 mm) by a screen printing method. The obtained printed matter was allowed to stand in a dryer set at 80 ° C. for 60 minutes to be heat-cured. As a result, a test plate having a coating film having a thickness of 20 μm was obtained.

(Evaluation method)
Each test plate produced in Examples and Comparative Examples was evaluated by a multi-angle colorimeter and a visual evaluation (color shift evaluation) by the same method as described above. The results are shown in Table 4.

[result]
Even when the composition for ink is screen-printed, it contains bright particles in which a reflective layer and an iron oxide layer are formed on aluminum and a coloring pigment, and the a ^* _{(75 °) of the} coating film is less than 17. When b ^* _{(75 °)} was less than 5, (Examples 13 to 15), the visual color shift evaluation was good. It can be said that the composition for ink of the present invention can obtain a coating film whose color and brightness greatly change regardless of the coating method and the type of coating film forming component.

6. Preparation of paint composition C
[Example 16]
The main agent (meth) acrylic resin a was changed to Acrydic WMG-521 (manufactured by DIC, acrylic resin solution for baking (nonvolatile content 59 to 61% by mass, acid value 5.5 to 7.5 mgKOH / g)). Except that the curing agent isocyanate compound was changed to Amidia L-125-60 (made by DIC, isobutylated melamine (nonvolatile content 58 to 62% by mass)) to obtain the composition ratio (solid content ratio) shown in Table 5. A coating composition (A-24) was prepared in the same manner as in Example 2.

[Example 17]
Change the main agent (meth) acrylic resin a to Acrydic A-9510 (manufactured by DIC, moisture-curable silicone acrylic resin solution (nonvolatile content 49-51% by mass, acid value 3.0 mgKOH / g (MAX))). , The curing agent isocyanate compound was changed to Acrydic A-9585: a moisture-curable silicone acrylic resin solution (nonvolatile content 80% by mass) manufactured by DIC Corporation) to obtain the composition ratio (solid content ratio) shown in Table 5. A coating composition (A-25) was prepared in the same manner as in Example 2 except for the above.

7. Evaluation C
Similar to Example 2, a test plate having a coating film having a thickness of 20 μm was prepared, and evaluation by a multi-angle colorimeter and visual evaluation (color shift evaluation) were performed by the same method as described above. The results are shown in Table 5.

[result]
Even when the coating film-forming component of the coating composition is changed, the coating film a ^* _{( When} ^{b *} _{(75 °)} was less than 17, and b * (75 °) was less than 5, (Examples 16 and 17), the visual color shift evaluation was good. It can be said that the coating composition of the present invention can provide a coating film having a large change in color and brightness regardless of the type of coating film-forming component.

8. Preparation of paint composition D
[Examples 18 to 21]
Coating compositions (A-26) to (A-29) were prepared in the same manner as in Example 2 except that the additives shown in Table 6 were mixed.

9. Evaluation D
Similar to Example 2, a test plate having a coating film having a thickness of 20 μm was prepared, and evaluation by a multi-angle colorimeter and visual evaluation (color shift evaluation) were performed by the same method as described above. The results are shown in Table 6.

Further, after storing the above composition for paint at 25 ° C. for 72 hours (after storage stability test), a test plate is prepared using the composition for paint, and evaluation by a multi-angle colorimeter and visual evaluation (color). Shift evaluation) was performed. The results are shown in Table 6. For comparison, Table 6 also shows the results of the same test conducted on the coating composition of Example 2 described above.

[result]
By adding fatty acid amide wax or the like to the composition for paints, the color shift evaluation after the storage stability test was better than when these were not added (Example 2). (Examples 18 to 21). In particular, when a fatty acid amide compound (fatty acid amide wax or higher fatty acid amide) is contained (Examples 18 and 19), the color shift evaluation immediately after the composition is prepared is the same as in Example 2 in which no additive is added. There was no inferiority in comparison. Further, when no additive is added or when a mineral-based additive is added, it is difficult to obtain a sufficient color shift after the storage stability test of the coating composition, whereas a fatty acid amide-based compound is contained. In the cases (Examples 18 and 19), excellent color change and brightness change were large even after the storage stability test, and good color shiftability was observed. It is considered that such a result was obtained because the fatty acid amide compound formed a network and the dispersibility of the glittering particles was enhanced.

According to the composition for forming a brilliant coating film of the present invention, a coating film whose color and brightness greatly change depending on the observation position can be obtained. Therefore, the present invention is very useful for manufacturing home appliances, electronic devices, housings for image display devices, automobile interior parts, and the like.

C Color pigment P Bright particles

Claims (7)

Glittering particles and
Color pigments and
It is a composition for forming a brilliant coating film containing
The glittering particles have aluminum, a reflective layer covering the aluminum, and an iron oxide layer covering the reflective layer.
A coating film having a thickness of 20 μm formed on a standard coated paper using the composition for forming a brilliant coating film has a specular reflection direction to an incident direction when visible light is incident on the coating film at an incident angle of 45 °. ^{The L *} a ^* b ^* color system a ^* value is less than 17 and the b ^* value is less than 5 of the light emitted in the direction inclined by 75 ° toward.
A composition for forming a brilliant coating film. The amount of iron element per 1 part by mass of aluminum element in the brilliant particles is 0.05 to 4 parts by mass.
The composition for forming a brilliant coating film according to claim 1. The reflective layer contains silicon dioxide.
The composition for forming a brilliant coating film according to claim 1 or 2. The amount of silicon element per 1 part by mass of aluminum element in the glittering particles is 0.05 to 0.5 part by mass.
The composition for forming a brilliant coating film according to claim 3. Further containing fatty acid amide compounds,
The composition for forming a brilliant coating film according to any one of claims 1 to 4. A composition for paints,
The composition for forming a brilliant coating film according to any one of claims 1 to 5. Ink composition,
The composition for forming a brilliant coating film according to any one of claims 1 to 5.

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