JP2022064710A - Flaky pigment, dispersion, coating, and coating layer - Google Patents

Abstract

To provide a flaky pigment having excellent durability, and having high visible-light transmissivity and infrared-ray reflectivity, and a dispersion, a coating, and a coating layer.SOLUTION: A flaky pigment has a first zinc sulfide layer, a second zinc sulfide layer, and a silver-containing metal layer disposed between the first zinc sulfide layer and the second zinc sulfide layer.SELECTED DRAWING: None

Description

The present invention relates to scaly pigments, dispersions, paints, and coatings.

Conventionally, a window film having functionality such as heat insulation, shading, prevention of debris scattering at the time of breakage, antifouling, dustproof, trauma prevention, antireflection, etc. has been proposed by being attached to windows of automobiles, buildings, etc. ing.
In recent years, there has been increasing interest in energy-saving measures, and from the viewpoint of reducing the load on cooling equipment, window films that can be attached to the window glass of buildings, automobiles, etc. to block the transmission of heat rays from sunlight. Development is in progress.

As the infrared reflective pigment used for such a window film, for example, a multilayer film in which a first metal film containing silver and a second metal oxide film containing titanium oxide or the like are alternately laminated is used. It has been proposed (see, for example, Patent Document 1). A second metal oxide film is arranged on both the upper surface and the lower surface (outermost surface) of such a multilayer film.

Japanese Unexamined Patent Publication No. 2019-85482

However, if the metal oxide film is arranged on the outermost surface of the multilayer film as in the above proposal, the durability is lowered, and surface treatment is required in order to handle the multilayer film as a pigment. In addition, if reactive film formation is performed as a film formation condition for the metal oxide film, the metal film will be oxidized and it will be difficult to obtain the desired infrared reflectivity. Therefore, there is also a problem in film formation of the metal oxide film. There is. Further, in the above proposal, there is a problem that it is difficult to match the simulated value and the measured value, and it is difficult to design the pigment.

An object of the present invention is to solve the above-mentioned problems in the prior art and to achieve the following objects. That is, an object of the present invention is to provide a scaly pigment, a dispersion liquid, a paint, and a coating film having excellent durability, high visible light transparency and infrared reflectivity.

The means for solving the above problems are as follows. That is,
<1> With the first zinc sulfide layer,
With the second zinc sulfide layer,
A silver-containing metal layer between the first zinc sulfide layer and the second zinc sulfide layer,
It is a scaly pigment characterized by having.
<2> The scaly pigment according to <1> above, which transmits visible light and reflects infrared rays.
<3> The scaly pigment according to any one of <1> to <2>, wherein the silver-containing metal layer has an average thickness of 9 nm or more and 18 nm or less.
<4> The scaly pigment according to any one of <1> to <3>, wherein the average thickness of the first zinc sulfide layer and the second zinc sulfide layer is 9 nm or more and 50 nm or less.
<5> The scaly pigment according to any one of <1> to <4>, which has a region having an infrared reflectance of 45% or more between a wavelength of 900 nm or more and 1100 nm or less.
<6> The scaly pigment according to any one of <1> to <5>, wherein the visible light transmittance at a wavelength of 550 nm is 70% or more.
<7> A dispersion liquid containing the scaly pigment according to any one of <1> to <6> and an organic solvent.
<8> The paint is characterized by containing the scaly pigment, the organic solvent, and the binder according to any one of <1> to <6>.
<9> A coating film comprising the scaly pigment and the binder according to any one of <1> to <6>.

According to the present invention, scaly pigments, dispersions, paints, and coatings that can solve the above-mentioned problems in the past, achieve the above-mentioned objects, have excellent durability, and have high visible light transmittance and infrared reflection. A membrane can be provided.

FIG. 1 is a schematic view showing an example of a scaly pigment of the present invention. FIG. 2 is a graph showing the results of measuring and simulating the transmittance and reflectance of the film-forming film produced in Example 1. FIG. 3 is a graph showing the results of measuring and simulating the transmittance and reflectance of the film-forming film produced in Comparative Example 1. FIG. 4 is a graph showing the results of measuring and simulating the transmittance and reflectance of the film-forming film produced in Comparative Example 2. FIG. 5 is an SEM photograph of the scaly pigment of Example 1. FIG. 6 is a diagram showing a volume-based particle size distribution of the scaly pigment of Example 1. FIG. 7 is a graph showing the results of measuring the transmittance of the film-forming films of Experimental Examples 1 to 6. FIG. 8 is a graph showing the results of measuring the reflectance of the film-forming films of Experimental Examples 1 to 6. FIG. 9 is an enlarged view of FIG. FIG. 10 is a graph showing the results of simulating the reflectance when the thickness of the ZnS layer is fixed at 20 nm in a film-forming film having a layer structure of ZnS / Ag / ZnS. FIG. 11 is a graph showing the result of simulating the transmittance when the thickness of the ZnS layer is fixed at 20 nm in the film-forming film having the layer structure of ZnS / Ag / ZnS. FIG. 12 is a graph showing the result of simulating the transmittance when the thickness of the Ag layer is fixed at 14 nm in the film-forming film having a layer structure of ZnS / Ag / ZnS. FIG. 13 is a graph showing the results of simulating the transmittance when the thickness of the Ag layer is fixed at 14 nm in the film-forming film having a layer structure of ZnS / Ag / ZnS. FIG. 14 is a graph showing the results of measuring the transmittance of the coating film in Examples 2 to 4. FIG. 15 is a graph showing the results of measuring the reflectance of the coating film in Examples 2 to 4. FIG. 16 is a graph showing the results of the transmittance of the film-forming film produced in Example 1 before and after the heat resistance and moisture resistance test. FIG. 17 is a graph showing the results of the transmittance of the film-forming film produced in Example 1 before and after the water resistance test. FIG. 18 is a graph showing the results of the transmittance of the film-forming film produced in Example 1 before and after the salt water resistance test.

(Scale pigment)
The scaly pigment of the present invention comprises a first zinc sulfide layer, a second zinc sulfide layer, and a silver-containing metal layer between the first zinc sulfide layer and the second zinc sulfide layer. , And further with other layers as needed.

In the present invention, the structure having the silver-containing metal layer between the first zinc sulfide layer and the second zinc sulfide layer, that is, the first zinc sulfide layer and the silver-containing metal layer. By forming the second zinc sulfide layer and the second zinc sulfide layer in this order, symmetry can be ensured and the optical characteristics of the pigment can be made uniform.
In addition, zinc sulfide (ZnS) is a stable material with a large refractive index (refractive index: 2.36), high infrared reflectivity and visible light transmission, and is sparingly soluble in water and has excellent durability. Therefore, it is possible to impart excellent durability, visible light transmission, and infrared reflectivity to the scaly pigment.

<Metal layer containing silver>
The silver (Ag) -containing metal layer preferably has a silver content of 80% by mass or more, more preferably 85% by mass or more, further preferably 90% by mass or more, and further preferably 95% by mass, from the viewpoint of visible light transmission. Mass% or more is particularly preferable. The silver-containing metal layer may contain palladium (Pd), copper (Cu), gold (Au), titanium (Ti), bismuth (Bi), or the like, in addition to silver (Ag).
The silver content in the metal layer can be measured, for example, by X-ray fluorescence analysis (XRF).
When the object and effect of the present invention can be obtained, as the metal layer, in addition to the silver-containing metal layer, aluminum (Al), copper (Cu), gold (Au), titanium (Ti), and iron. A metal layer containing (Fe), chromium (Cr), tin (Sn), indium (In), silicon (Si), bismuth (Bi), palladium (Pd) or an alloy thereof can also be used.

The average thickness of the silver-containing metal layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 9 nm or more and 18 nm or less. If the average thickness of the silver-containing metal layer is less than 9 nm, silver may be oxidized, the infrared reflection performance may be deteriorated, and the heat shielding property may be deteriorated. On the other hand, when the average thickness of the silver-containing metal layer exceeds 18 nm, metal reflection is conspicuous and infrared reflection performance is high, but visible light transmission performance may not be obtained.
As the average thickness of the silver-containing metal layer, for example, when manufactured by the physical vapor deposition method, the thickness of the silver-containing metal layer is measured at 5 to 10 points and averaged. It is the same as the average vapor deposition thickness.
Examples of the method for measuring the average thickness include scanning electron microscope (SEM) observation, fluorescent X-ray analysis (XRF), and ultraviolet-visible spectroscopy.
When the average thickness is obtained by observation with the scanning electron microscope (SEM), the cross section of the thin-film vapor-deposited film containing the silver is observed using the scanning electron microscope (SEM), and the silver at 5 to 10 places is observed. The thickness of the contained metal layer can be measured, and the average vapor deposition thickness can be taken as the average thickness.
When the average thickness is obtained by the fluorescent X-ray analysis method (XRF), the thickness of the silver-containing metal layer at 5 to 10 points may be measured by quantitative analysis, and the average value may be used as the average thickness. can.
When the average thickness is obtained by the ultraviolet-visible spectroscopy method, the reflectance of the silver-containing metal layer is measured at 5 to 10 points by an ultraviolet-visible spectrophotometer, and the silver is contained from the obtained reflectance spectrum. The thickness of the metal layer to be formed can be calculated, and the average value can be used as the average thickness.

<First and second zinc sulfide layers>
The content of zinc sulfide (ZnS) in the first and second zinc sulfide layers is preferably 98% by mass or more, more preferably 99% by mass or more, still more preferably 99.9% by mass or more.
The zinc sulfide content in the first and second zinc sulfide layers can be measured, for example, by fluorescent X-ray analysis (XRF).
The average thickness of the first and second zinc sulfide layers is preferably 9 nm or more and 50 nm or less, and more preferably 9 nm or more and 30 nm or less. If the average thickness of the first and second zinc sulfide layers is less than 9 nm, zinc sulfide may become a discontinuous film and the visible light transmittance may decrease. On the other hand, if the average thickness of the first and second zinc sulfide layers exceeds 50 nm, an interference color due to the zinc sulfide layers may occur, and high visible light transmittance may not be obtained.

<Other layers>
Examples of the other layer include a peeling layer for peeling a laminate composed of the first and second zinc sulfide layers and the silver-containing metal layer from the base material by dissolving.

The pigment having the silver-containing metal layer between the first zinc sulfide layer and the second zinc sulfide layer of the present invention is scaly. The scaly pigment is preferably in the form of particles, and may be referred to as scaly particles, flaky particles, tabular particles, flake-like particles, or the like.
In the present invention, the scaly pigment means particles having a substantially flat surface and having a substantially uniform thickness in the direction perpendicular to the substantially flat surface.
The shape of the substantially flat surface is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a substantially circular shape, a substantially elliptical shape, a substantially triangular shape, a substantially quadrangle, a substantially pentagonal shape, a substantially hexagonal shape, and a substantially heptagon. Examples include polygons such as quadrangles and substantially octagons, and random indefinite shapes.

The cumulative 50% volume particle diameter _D50 of the scaly pigment is preferably 0.5 μm or more and 100 μm or less, more preferably 1 μm or more and 30 μm or less, and 10 μm from the viewpoint of dispersibility when dispersed in the dispersion liquid and the coating material. More preferably 30 μm or less.
When the cumulative 50% volume particle diameter D ₅₀ is less than 0.5 μm, excellent performance as a coating film is obtained, but it may be difficult to obtain a size effect.
The cumulative 50% volume particle diameter D ₅₀ is a particle size corresponding to 50% of the volume distribution cumulative amount of the particle size distribution curve obtained by the laser diffraction method, and the non-spherical scaly pigment is assumed to be a perfect sphere. It is the average length of the major axis and the minor axis of the scaly pigment when measured. However, the actual scaly pigment is not spherical, but scaly with long and short sides. Therefore, the D ₅₀ is a value different from the actual length (major axis) in the long side direction and the length (minor axis) in the short side direction of the scaly pigment.
Examples of the means using the laser diffraction method include a laser diffraction / scattering type particle size distribution measuring instrument.

The average thickness of the scaly pigment is preferably 25 nm or more, more preferably 40 nm or more. The upper limit of the average thickness of the scaly pigment is preferably 120 nm or less.
The ratio of the scaly pigments (cumulative 50% volume particle diameter D ₅₀ / average thickness) is preferably 80 or more, more preferably 300 or more.
The ratio of "D ₅₀ (nm) / average thickness (nm)" in the present invention is obtained by observing D ₅₀ measured by a laser diffraction method with a scanning electron microscope (SEM) or analyzing fluorescent X-rays. It is a ratio calculated by dividing by the obtained average thickness. Therefore, the ratio of "D ₅₀ (nm) / average thickness (nm)" is different from the parameter generally called the aspect ratio.

The scaly pigment can transmit visible light and reflect infrared rays.
The scaly pigment preferably has a region (point, range) having an infrared reflectance of 45% or more, and more preferably 50% or more, between wavelengths of 900 nm or more and 1100 nm or less. That is, it suffices to have at least one region having an infrared reflectance of 45% or more between the wavelengths of 900 nm or more and 1100 nm or less. Since the infrared reflectance increases with an increase in wavelength, the infrared reflectance at a wavelength of 1100 nm is preferably 45% or more, and more preferably 50% or more.
The scaly pigment preferably has a visible light transmittance of 70% or more, and more preferably 80% or more at a wavelength of 550 nm.
The infrared reflectance and visible light transmittance can be measured using, for example, a spectrophotometer (SolidSpec-3700, manufactured by Shimadzu Corporation) or the like.

Here, the scaly pigment has a structure having a metal layer containing the silver between the first zinc sulfide layer and the second zinc sulfide layer, and specifically, it is shown in FIG. Has an aspect. The scaly pigment 10 of FIG. 1 has a structure in which a first zinc sulfide layer 1, a silver-containing metal layer 2, and a second zinc sulfide layer 3 are laminated in this order.

(Manufacturing method of scaly pigment)
In the method for producing a scaly pigment of the present invention, a release layer is formed on a substrate, a first zinc sulfide layer is formed on the release layer by a vapor phase method, and silver is formed on the first zinc sulfide layer. A metal layer containing zinc sulfide is formed by a vapor phase method, and a second zinc sulfide layer is formed on the silver-containing metal layer by a vapor phase method to obtain a laminate, and then the laminate is obtained from the substrate. Is peeled off and the laminate is crushed, whereby the scaly pigment 10 as shown in FIG. 1 can be efficiently produced.

More specifically, the method for producing a scaly pigment of the present invention includes a release layer forming step, a first zinc sulfide layer forming step, a silver-containing metal layer forming step, and a second zinc sulfide layer forming. It includes a step, a peeling step, a crushing step, and if necessary, other steps.

<Peeling layer forming process>
The peeling layer forming step is a step of providing the peeling layer on the base material.

-Base material-
The base material is not particularly limited as long as it has a smooth surface, and various materials can be used. Among these, a resin film having flexibility, heat resistance, solvent resistance, and dimensional stability, a metal, and a composite film of a metal and a resin film can be appropriately used.
Examples of the resin film include a polyester film, a polyethylene film, a polypropylene film, a polystyrene film, a polyimide film and the like. Examples of the metal include copper foil, aluminum foil, nickel foil, iron foil, alloy foil and the like. Examples of the composite film of the metal and the resin film include a laminate of the resin film and the metal.

-Release layer-
As the peeling layer, various organic substances or solvents such as water that can be dissolved in the subsequent peeling step can be used. Further, if the organic material constituting the release layer is appropriately selected, the organic substance adhering to or remaining on the silver-containing metal layer or the first and second zinc sulfide layers can be removed from the protective layer of the scaly pigment. It is suitable because it can function as.
The protective layer has a function of suppressing aggregation, oxidation, elution into a solvent, and the like of the scaly pigment. In particular, it is preferable to use the organic substance used for the peeling layer as the protective layer because it is not necessary to separately provide a surface treatment step.
Examples of the organic substance constituting the release layer that can be used as the protective layer include cellulose acetate butyrate (CAB), other cellulose derivatives, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polyacrylic acid, polyacrylamide, and acrylic. Examples thereof include acid copolymers and modified nylon resins. These may be used alone or in combination of two or more. Among these, cellulose acetate butyrate (CAB) is preferable from the viewpoint of high function as the protective layer.

The method for forming the release layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an inkjet method, a blade coating method, a gravure coating method, a gravure offset coating method, a bar coating method, and a roll coating method can be selected. , Knife coat method, air knife coat method, comma coat method, U comma coat method, AKKU coat method, smoothing coat method, micro gravure coat method, reverse roll coat method, 4 roll coat method, 5 roll coat method, dip coat Examples include the method, the curtain coat method, the slide coat method, and the die coat method. These may be used alone or in combination of two or more.

<First zinc sulfide layer forming step>
The first zinc sulfide layer forming step is a step of forming a first zinc sulfide layer on the peeling layer by a vapor phase method.

Examples of the vapor phase method include a vapor deposition method and a sputtering method, which are collectively referred to as a physical vapor deposition (PVD).

<Silver-containing metal layer forming process>
The silver-containing metal layer forming step is a step of forming a silver-containing metal layer on the first zinc sulfide layer by a vapor phase method.

Examples of the vapor phase method include a vapor deposition method and a sputtering method, which are collectively referred to as a physical vapor deposition (PVD).

<Second zinc sulfide layer forming step>
The second zinc sulfide layer forming step is a step of forming a second zinc sulfide layer on the silver-containing metal layer by a vapor phase method.
As described above, a laminate in which the first zinc sulfide layer, the silver-containing metal layer, and the second zinc sulfide layer are laminated in this order is formed on the release layer of the base material.

Examples of the vapor phase method include a vapor deposition method and a sputtering method, which are collectively referred to as a physical vapor deposition (PVD).

<Peeling process>
The peeling step is a step of peeling the laminate by dissolving the peeling layer.
The solvent capable of dissolving the peeling layer is not particularly limited as long as it is a solvent capable of dissolving the peeling layer, and can be appropriately selected depending on the intended purpose.

The solvent capable of dissolving the release layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, methanol, ethanol, propanol, isopropanol, butanol, octanol, dodecanol, ethylene glycol, propylene glycol and the like can be selected. Alcohols; Ethers such as tetrahydrones; Ketones such as acetone, methyl ethyl ketone, acetyl acetone; Esters such as methyl acetate, ethyl acetate, butyl acetate, phenyl acetate; Ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethylene Glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol Diethyl Ether, Triethielene Glycol Monomethyl Ether, Triethylene Glycol Monoethyl Ether, Triethylene Glycol Monobutyl Ether, Propylene Glycol Monomethyl Ether, Propylene Glycol Monoethyl Ether, Dipropylene Glycol Monomethyl Ether, Dipropylene Glycol Monoethyl Ether, Diethylene Glycol Monomethyl Ether Glycol ethers such as acetate; phenols such as phenol and cresol; pentane, hexane, heptane, octane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, octadecene, benzene, toluene, xylene, trimesine, nitrobenzene, aniline, methoxy Aliphatic or aromatic hydrocarbons such as benzene; aliphatic or aromatic chloride hydrocarbons such as dichloromethane, chloroform, trichloroethane, chlorobenzene, dichlorobenzene; sulfur-containing compounds such as dimethylsulfoxide; dimethylformamide, dimethylacetamide, acetonitrile, propio Examples thereof include nitrogen-containing compounds such as nitrile and benzonitrile, and water. These may be used alone or in combination of two or more.

<Crushing process>
The crushing step is a step of crushing the laminate peeled from the base material in the peeling step.

The method used in the pulverization step is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a jet mill, a ball mill, a bead mill, a vibration mill, and an ultrasonic homogenizer.
Further, if necessary, various treatments may be performed for recovering the scaly pigment and adjusting the physical characteristics. For example, the particle size of the scaly pigment may be adjusted by classification, the scaly pigment may be recovered by a method such as centrifugation or suction filtration, or the solid content concentration of the dispersion may be adjusted. Further, solvent substitution may be performed, or viscosity may be adjusted by using an additive.

<Other processes>
Examples of the other steps include a step of taking out the pulverized scaly pigment as a dispersion liquid, a step of recovering the scaly pigment from the dispersion liquid, and the like.

(Dispersion)
The dispersion liquid of the present invention contains the scaly pigment of the present invention and an organic solvent, and further contains other components as necessary.
The dispersion liquid of the present invention may be either aqueous or solvent-based, but aqueous is preferable from the viewpoint of environmental friendliness.

The content of the scaly pigment is preferably 0.1% by mass or more and 50% by mass or less with respect to the total amount of the dispersion liquid.

-Organic solvent-
The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds and amides can be selected. Classes, amines, sulfur-containing compounds and the like. These may be used alone or in combination of two or more.

Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butanediol. 2,3-Butanediol, 3-Methyl-1,3-Butanediol, Triethyleneglycol, Polyethylene Glycol, Polypropylene Glycol, 1,2-Pentanediol, 1,3-Pentanediol, 1,4-Pentanediol, 2 , 4-Pentanediol, 1,5-Pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanediol, 1,2,3-butanetriol, 2,2,4-trimethyl-1, Examples include 3-pentanediol.

Examples of the polyvalent alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Be done.

Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-. Butyrolactone and the like can be mentioned.

Examples of the amides include formamide, N-methylformamide, N, N-dimethylformamide, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide and the like.

Examples of the amines include monoethanolamine, diethanolamine, triethylamine and the like.
Examples of the sulfur-containing compound include dimethyl sulfoxide, sulfolane, and thiodiethanol.

-Other ingredients-
The other components are not particularly limited and may be appropriately selected depending on the intended purpose. For example, water, a polymer, a cross-linking agent, an antioxidant, a filler, a polymerization inhibitor, a surface regulator, and an antistatic agent. , Antifoaming agent, viscosity modifier, light-resistant stabilizer, weather-resistant stabilizer, heat-resistant stabilizer, antioxidant, leveling agent, antiseptic antifungal agent, rust preventive agent, pH adjuster and the like.

-water-
As the water, for example, pure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, or ultrapure water can be used.

(paint)
The paint of the present invention contains the scaly pigment of the present invention, preferably contains an organic solvent and a binder, and further contains other components as necessary.
The paint of the present invention may be either water-based or solvent-based.

-Scale pigment-
The paint of the present invention may contain a brilliant pigment other than the scaly pigment, if necessary. Examples of the other brilliant pigments include metal pigments (for example, aluminum pigments), pigments obtained from natural mica (for example, pearl pigments), and glass flake pigments.
The content of the scaly pigment is not particularly limited and may be appropriately selected depending on the intended purpose.

-binder-
The binder is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyurethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene type. Examples thereof include resins, vinyl chloride resins, acrylic-styrene resins, acrylic-silicone resins, polyvinyl alcohol resins, polyether resins, alkyd resins, polyvinylpyrrolidone, and cellulose.
When the paint contains the binder, a paint having excellent fixability and dispersibility can be obtained.
The content of the binder is not particularly limited and may be appropriately selected depending on the intended purpose.

As the organic solvent and water in the coating material, the same organic solvent and water as in the dispersion liquid can be used.

-Other ingredients-
The other components are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include surfactants, antifoaming agents, antiseptic and antifungal agents, rust preventives and pH adjusters.

The paint of the present invention is, for example, an inkjet method, a gravure coating method, a screen printing method, a spray coating method, a spin coating method, a blade coating method, a gravure offset coating method, a bar coating method, a roll coating method, a knife coating method, and an air knife coating. Method, comma coat method, U comma coat method, AKKU coat method, smoothing coat method, micro gravure coat method, reverse roll coat method, 4-roll coat method, 5-roll coat method, dip coat method, curtain coat method, slide It can be used for coating methods such as a coating method and a die coating method. Among these, the bar coat method and the spray coating method are preferable.

(Coating film)
The coating film of the present invention contains the scaly pigment of the present invention and a binder, and further contains other components as necessary.
The coating film may be used alone, or may be a coated product formed by the above-mentioned coating method using the coating film of the present invention on a substrate.
The substrate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, plain paper, glossy paper, special paper, cloth, film, transparency sheet, general-purpose printing paper, automobile window glass and film, etc. Examples include building windowpanes and films, transparencies, and the like.

<Use>
Since the scaly pigment of the present invention has excellent durability, visible light transmission, and infrared reflectance, it can be widely used in various fields, for example, glass and film for vehicles, glass and film for building materials, and agriculture. It is suitably used for films and the like.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to these examples.

(Example 1)
A solution containing 5% by mass of cellulose acetate butyrate (CAB) is coated on a polyethylene terephthalate (PET) film having an average thickness of 25 μm by a gravure coating method at an amount of 0.06 g / m ² ± 0.01 g / m ² . And dried at 110 ° C. or higher and 120 ° C. or lower to form a release layer.
Next, zinc sulfide was formed on the release layer by an electron beam heating / vacuum vapor deposition method at a film formation rate of 40 nm / min. To form a first zinc sulfide layer having an average thickness of 20 nm. The average thickness of the first zinc sulfide layer is a value obtained by measuring the thicknesses of the first zinc sulfide layers at five locations by quantitative analysis using a fluorescent X-ray analysis method (XRF) and averaging them.

Next, silver was deposited on the first zinc sulfide layer by a sputtering method at a film formation rate of 3 nm / min. A metal layer containing silver having an average thickness of 12 nm was formed. The silver content in the metal layer measured by X-ray fluorescence analysis (XRF) was 85% by mass.

Next, a second zinc sulfide layer having an average thickness of 20 nm was formed on the silver-containing metal layer by the same method as the first zinc sulfide layer. The method of obtaining the average thickness of the silver-containing metal layer is the same as the method of obtaining the average thickness of the zinc sulfide layer. Table 1 shows the results of the average thickness of the first zinc sulfide layer, the second zinc sulfide layer, and the silver-containing metal layer.
As a result, a laminate (film-forming film) in which a release layer, a first zinc sulfide, a silver-containing metal layer, and a second zinc sulfide layer were laminated in this order on a PET film was obtained.

(Comparative Example 1)
In Example 1, instead of forming the first zinc sulfide layer and the second zinc sulfide layer, titanium oxide was formed at a film formation rate of 2 nm / min by a reactive sputtering method while introducing oxygen. To form a first titanium oxide layer and a second titanium oxide layer having an average thickness of 20 nm, a film-forming film was obtained.
With respect to the obtained film-forming film, the average thickness of each layer was measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
In Example 1, instead of forming the first zinc sulfide layer and the second zinc sulfide layer, Nb ₂ O ₃ was formed at a film formation rate of 2 nm / min by a reactive sputtering method while introducing oxygen. To form a first Nb ₂ O ₃ layer and a second Nb ₂ O ₃ layer having an average thickness of 20 nm, a film-forming film was obtained.
With respect to the obtained film-forming film, the average thickness of each layer was measured in the same manner as in Example 1. The results are shown in Table 1.

Next, with respect to the film-forming films of Example 1 and Comparative Examples 1 and 2, the transmittance and the reflectance were measured as follows, and the results of comparing the simulated values and the measured values of the transmittance and the reflectance were obtained. It is shown in FIGS. 2 to 4.

<Measurement of transmittance and reflectance>
For each film-forming film, a spectrophotometer (SolidSpec-3700, manufactured by Shimadzu Corporation) was used to realize the transmittance and reflectance of a wavelength of 300 nm or more and 2500 nm or less.
On the other hand, as the simulation software, optical thin film design software (TFVver.3, manufactured by Narry Software Co., Ltd.) was used, and the simulated values of the transmittance and the reflectance were obtained.
The transmittance was set to Air (air), that is, the state where no sample was placed, as 100% in both the actual measurement and the simulation.
The reflectance is the reflectance in the 5 ° specular reflection direction when light is incident from an angle 5 ° inclined from the normal direction of each film-forming film in both actual measurement and simulation. As for the reflectance, the reflectance when a mirror was installed instead of each film-forming film was set to 100%. In the actual measurement of the reflectance, a mirror made of aluminum was used.

From the results of FIG. 2, it was found that in Example 1, the simulated values and the measured values of the transmittance and the reflectance are relatively in agreement, and it is easy to design the pigment (film-forming film). On the other hand, from the results of FIGS. 3 and 4, in Comparative Examples 1 and 2, the simulated values of the transmittance and the reflectance do not match the actual side values, and it is difficult to design the pigment. have understood. It was found that when the average thickness of the single layer of the metal oxide layer was laminated under the reactive sputtering conditions as in Comparative Examples 1 and 2, the spectral spectrum did not match the simulation. It is considered that this is because oxygen (O ₂ ) at the time of reactive sputtering oxidizes silver (Ag).
On the other hand, in Example 1, since it is not necessary to introduce oxygen into the zinc sulfide (ZnS) layer to form a film, Ag is not oxidized, and the simulated value and the measured value are in agreement, which is excellent optics. It turned out that the characteristics can be realized.

<Making scale pigments>
Next, in Example 1, butyl acetate was sprayed onto the surface of the PET film on which the release layer and the laminate were formed to dissolve the release layer, and the laminate was scraped off with a doctor blade.
Next, in order to adjust the particle size, the obtained mixture of the laminate and butyl acetate was subjected to sonication and pulverized until the target cumulative 50% volume particle size was 18 μm. As a result, the scaly pigment of Example 1 was obtained. The SEM photograph of the obtained scaly pigment of Example 1 is shown in FIG. From the SEM photograph of FIG. 5, it was found that the pigment of Example 1 had a scaly shape.

<Measurement of particle size distribution>
For the obtained scaly pigment of Example 1, the particle size distribution was measured using a laser diffraction / scattering type particle size distribution measuring device (LSM-2000, manufactured by Seishin Corporation), and a cumulative 50% volume particle diameter _D50 was obtained. When determined, it was 18 μm. The result of the particle size distribution of Example 1 is shown in FIG.

(Experimental Examples 1 to 6)
<Optimization of average thickness of silver-containing metal layer and zinc sulfide layer>
In the same manner as in Example 1, the film-forming films of Experimental Examples 1 to 6 having the layer structure shown in Table 2 and the metal layer (Ag layer) and the zinc sulfide layer (ZnS layer) containing silver having an average thickness were prepared. bottom.

Next, the transmittance and reflectance of the obtained film-forming films of Experimental Examples 1 to 6 were measured in the same manner as in Example 1. The results are shown in FIGS. 7 to 9.
Further, in the case where the thickness of the ZnS layer was fixed at 20 nm in the film-forming film having a layer structure of ZnS / Ag / ZnS, a simulation was performed in the same manner as in Example 1 to determine the reflectance and the transmittance. The results are shown in FIGS. 10 and 11.
Further, in the case where the thickness of the Ag layer was fixed at 14 nm in the film-forming film having a layer structure of ZnS / Ag / ZnS, a simulation was performed in the same manner as in Example 1 to determine the transmittance. The results are shown in FIGS. 12 and 13.
Here, the Ag layer refers to a metal layer containing silver, and the ZnS layer refers to a zinc sulfide layer.

Next, the film-forming films of Experimental Examples 1 to 6 obtained were subjected to visible light transmission, infrared reflectivity, and comprehensive evaluation as follows. The results are shown in Table 2.

<Visible light transmission>
When the visible light transmittance at a wavelength of 550 nm was 70% or more, it was evaluated as “◯”, and when it was not satisfied, it was evaluated as “x”.

<Infrared reflectivity>
It was evaluated as "◯" if it had a region where the infrared reflectance was 45% or more between the wavelengths of 900 nm or more and 1100 nm or less, and "x" if it did not.

<Comprehensive evaluation>
If both the conditions of having a visible light transmittance of 70% or more at a wavelength of 550 nm and having a region having an infrared reflectance of 45% or more between wavelengths of 900 nm or more and 1100 nm or less are satisfied, " 〇 ”, and if either condition or both conditions were not satisfied, it was evaluated as“ × ”.

From the actual measurement results of Table 2 and FIGS. 7 to 9, the thickness of the Ag layer is 9 nm or more. Further, from the result of the simulation of FIG. 10, the lower limit of the thickness of the Ag layer is 9 nm based on the condition that the infrared reflectance is 45% or more between the wavelengths of 900 nm or more and 1100 nm or less.

From the result of the simulation of the visible light transmittance in FIG. 11, the upper limit of the thickness of the Ag layer is 18 nm based on the condition that the visible light transmittance at a wavelength of 700 nm is 50% or more.
From the result of the simulation of the visible light transmittance in FIG. 12, the lower limit of the thickness of the ZnS layer is 9 nm based on the condition that the visible light transmittance at a wavelength of 700 nm is 45% or more.
From the result of the simulation of the visible light transmittance in FIG. 13, the upper limit of the thickness of the ZnS layer is 50 nm based on the limit that the interference color becomes intense in the visible light wavelength region.

(Examples 2 to 4)
<Preparation of pigment dispersion>
The scaly pigment produced in Example 1 was dispersed with an organic solvent (butyl acetate) to prepare pigment dispersions of Examples 2 to 4 having the pigment concentrations shown in Table 3.

<Preparation of paint>
The compositions shown in Table 3 below were mixed to prepare the coating materials of Examples 2 to 4.

＊バインダー：ブチラール樹脂（商品名エスレック、積水化学株式会社製）：酢酸ブチル＝２０：８０（ブチラール樹脂２０質量％溶解品）
＊有機溶剤：酢酸ブチル：シクロヘキサノン＝１：１

* Binder: Butyl resin (trade name: Eslek, manufactured by Sekisui Chemical Co., Ltd.): Butyl acetate = 20:80 (20% by mass of butyl resin dissolved)
* Organic solvent: Butyl acetate: Cyclohexanone = 1: 1

<Coating film formation>
Next, each of the prepared paints was applied as a base material on a polyethylene terephthalate (PET) film having an average thickness of 125 μm by a bar coating method, and dried at 120 ° C. for 10 minutes to form a coating film.
Next, the transmittance and infrared reflectance of each of the obtained coating films were measured in the same manner as in Example 1. The results are shown in FIGS. 14 and 15.
From the results of FIGS. 14 and 15, by using a coating film containing a laminate designed with infrared reflectance and transmittance as a pigment, a coating film having high reflectivity in the infrared region and high transmittance in the visible light region. It turned out that it can be produced.

(Example 5)
<Durability test>
The film-forming film produced in Example 1 was subjected to a heat resistance / moisture resistance test, a water resistance test, and a salt water resistance test as follows.

-Heat and moisture resistance test-
Condition (1): The film-forming film produced in Example 1 is treated at 90 ° C. for 30 minutes using a dryer. The transmittance of a wavelength of 300 nm or more and 2500 nm or less was measured using (manufactured by Shimadzu Corporation). The results are shown in FIG.

Condition (2): The above-mentioned conditions (2) are applied to the film-forming film before and after the heat-resistant and moisture-resistant test in which the film-forming film produced in Example 1 is treated for 30 minutes using a constant temperature and humidity chamber (90% RH at 60 ° C.). In the same manner as in 1), the transmittance with a wavelength of 300 nm or more and 2500 nm or less was measured. The results are shown in FIG.

Condition (3): The film-forming film produced in Example 1 is treated at 90 ° C. for 1,000 hours at 90 ° C. for 1,000 hours, and the film-forming film before and after the heat resistance / moisture resistance test is the same as the above-mentioned condition (1). Then, the transmittance of a wavelength of 300 nm or more and 2500 nm or less was measured. The results are shown in FIG.

Condition (4): About the film-forming film before and after the heat and moisture resistance test in which the film-forming film produced in Example 1 is treated for 1,000 hours using a constant temperature and humidity chamber (condition of 90% RH at 60 ° C.). In the same manner as in the above condition (1), the transmittance with a wavelength of 300 nm or more and 2500 nm or less was measured. The results are shown in FIG.

From the results of FIG. 16, it was found that there was almost no change in the transmittance under the above conditions (1) to (4), and the film-forming film produced in Example 1 was excellent in heat resistance and moisture resistance.

-Water resistance test-
Condition (1): The film-forming film produced in Example 1 is immersed in water at room temperature (25 ° C.) and treated for 30 minutes. A transmittance of a wavelength of 300 nm or more and 2500 nm or less was measured using (manufactured by Shimadzu Corporation). The results are shown in FIG.

Condition (2): The film-forming film produced in Example 1 is immersed in cold water (5 ° C.) for 30 minutes, and the film-forming film before and after the water resistance test is subjected to the same procedure as in the above condition (1). The transmittance of a wavelength of 300 nm or more and 2500 nm or less was measured. The results are shown in FIG.

From the results of FIG. 17, it was found that there was almost no change in the transmittance under the above conditions (1) and (2), and the film-forming film produced in Example 1 was excellent in water resistance.

-Salt water resistance test-
Condition (1): The film-forming film produced in Example 1 was immersed in salt water (NaCl concentration: 5% by mass) for 8 hours. The container was kept warm in a water bath at 40 ° C. The film-forming film after immersion was rinsed with pure water, and the water was wiped off. The transmittance of the film-forming film before and after this salt water resistance test was measured using a spectrophotometer (SolidSpec-3700, manufactured by Shimadzu Corporation) with a wavelength of 300 nm or more and 2500 nm or less. The results are shown in FIG.

Condition (2): The film-forming film produced in Example 1 was immersed in salt water (NaCl concentration: 5% by mass) for 24 hours. The container was kept warm in a water bath at 40 ° C. The film-forming film after immersion was rinsed with pure water, and the water was wiped off. With respect to the film-forming film before and after this salt water resistance test, the transmittance of the film having a wavelength of 300 nm or more and 2500 nm or less was measured in the same manner as in the above condition (1). The results are shown in FIG.

From the results shown in FIG. 18, under the above conditions (1) and (2), the transmittance tends to decrease slightly, but no corrosion is observed, and the film-forming film produced in Example 1 has good salt water resistance. It turned out to be.

1 1st zinc sulfide layer 2 Silver-containing metal layer 3 2nd zinc sulfide layer 10 scaly pigment

Claims (9)

The first zinc sulfide layer and
With the second zinc sulfide layer,
A silver-containing metal layer between the first zinc sulfide layer and the second zinc sulfide layer,
A scaly pigment characterized by having. The scaly pigment according to claim 1, which transmits visible light and reflects infrared rays. The scaly pigment according to any one of claims 1 to 2, wherein the silver-containing metal layer has an average thickness of 9 nm or more and 18 nm or less. The scaly pigment according to any one of claims 1 to 3, wherein the first zinc sulfide layer and the second zinc sulfide layer have an average thickness of 9 nm or more and 50 nm or less. The scaly pigment according to any one of claims 1 to 4, which has a region having an infrared reflectance of 45% or more between a wavelength of 900 nm or more and 1100 nm or less. The scaly pigment according to any one of claims 1 to 5, wherein the visible light transmittance at a wavelength of 550 nm is 70% or more. A dispersion liquid containing the scaly pigment according to any one of claims 1 to 6 and an organic solvent. A coating material comprising the scaly pigment according to any one of claims 1 to 6, an organic solvent, and a binder. A coating film comprising the scaly pigment and the binder according to any one of claims 1 to 6.

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