JP2021100994A - Active energy ray-curable ink and cured coating film - Google Patents

Abstract

To provide an active energy ray-curable ink enabling obtaining a cured coating film which has excellent metallic designability (high gross value) compared to a conventional active energy ray-curable ink using flaky aluminum particles, and to provide a cured coating film.SOLUTION: An active energy ray-curable ink contains scaly indium particles. In preferred aspects, an average thickness of the scaly indium particles is 60nm or less, a cumulative 50% volume particle diameter D50 of the scaly indium particles is 0.7 μm or less, a polymerizable compound is contained, and a polymerization initiator is further contained.SELECTED DRAWING: None

Description

The present invention relates to an active energy ray-curable ink and a cured coating film.

In recent years, a method of blending a metal pigment into an ink composition has been developed in order to obtain a coating film having a brilliant feeling, and various inks such as water-based inks, organic solvent-based inks, and active energy ray-curable inks have been developed. Attempts have been made to blend metal pigments with respect to the form.

For example, in order to obtain a cured coating film having a brilliant feeling and excellent abrasion resistance, an active energy ray-curable composition using scaly aluminum particles as a brilliant metal pigment has been proposed (for example, Patent Documents). 1).

JP-A-2017-52870

In Patent Document 1, the ejection stability and abrasion resistance are evaluated by using an active energy ray-curable ink containing scaly aluminum particles, but the metal design (high gloss value) is evaluated. Not. Further, in Patent Document 1, the use of scaly indium particles and the active energy ray-curable ink containing scaly indium particles are superior to the active energy ray-curable ink containing scaly aluminum particles. There is no description or suggestion that the designability (high gloss value) can be realized, and the features of the present invention are not clarified at all.

An object of the present invention is to solve the above-mentioned problems in the past and to achieve the following object. That is, the present invention provides an active energy ray-curable ink that can obtain a cured coating film having excellent metal-like design (high gloss value) as compared with the conventional active energy ray-curable ink using scaly aluminum particles. It is an object of the present invention to provide a cured coating film.

The means for solving the above-mentioned problems are as follows. That is,
<1> An active energy ray-curable ink characterized by containing scaly indium particles.
<2> The active energy ray-curable ink according to <1>, wherein the scaly indium particles have an average thickness of 60 nm or less.
<3> The active energy ray-curable ink according to any one of <1> to <2>, wherein the cumulative 50% volume particle size D _{50 of the scaly indium particles is 0.7 μm or less.}
<4> The active energy ray-curable ink according to any one of <1> to <3>, which contains a polymerizable compound.
<5> The active energy ray-curable ink according to <4>, wherein the polymerizable compound contains a monofunctional monomer and a polyfunctional monomer.
<6> The active energy ray-curable ink according to any one of <1> to <5>, which further contains a polymerization initiator.
<7> A cured coating film obtained by applying the active energy ray-curable ink according to any one of <1> to <6>.
<8> The difference (Gs20 ° -Gs60 °) between the gloss value (Gs20 °) at an incident angle of 20 ° and the gloss value (Gs60 °) at an incident angle of 60 ° is 150 or more, and the ratio (Gs20 ° / Gs60 °). ) Is the cured coating film according to <7>, which satisfies at least one of 1.3 or more.

According to the present invention, the above-mentioned problems in the prior art can be solved and the above-mentioned object can be achieved, and the metal-like design property (high gloss) is superior to that of the conventional active energy ray-curable ink using scaly aluminum particles. It is possible to provide an active energy ray-curable ink and a cured coating film that can obtain a cured coating film having a value).

FIG. 1 is a graph showing the results of volume-based particle size distribution in the scaly indium particles of Production Examples 2 to 6 and the scaly aluminum particles of Comparative Production Example 2. FIG. 2 is an SEM photograph of the cured coating film of Example 15 at an inclination angle of 90 °. FIG. 3 is an SEM photograph of the cured coating film of Example 15 at an inclination angle of 60 °. FIG. 4 is an SEM photograph of the cured coating film of Comparative Example 4 at an inclination angle of 90 °. FIG. 5 is an SEM photograph of the cured coating film of Comparative Example 4 at an inclination angle of 60 °.

(Active energy ray-curable ink)
The active energy ray-curable ink of the present invention preferably contains scaly indium particles, preferably contains a polymerizable compound and a polymerization initiator, and further contains other components as necessary.

According to the active energy ray-curable ink containing scaly indium particles of the present invention, excellent metal design (high gloss value) is obtained as compared with the conventional active energy ray-curable ink using scaly aluminum particles. A cured coating film having is obtained.
The scaly indium particles used in the present invention have a cumulative 50% smaller volume particle size than the conventional scaly aluminum particles, and a bimodal distribution having two peaks of ultrafine particles and fine particles can be obtained (). (See FIG. 1). When such scaly indium particles are used in an active energy ray-curable ink, a cured coating film that is extremely densely packed and has a low surface roughness Ra can be obtained. The spatial ratio (the ratio of the space existing between the particles in the particle packing layer) indicating the degree of filling is reduced by the inclusion of the ultrafine particles in the gaps between the ultrafine particles in the presence of the ultrafine particles and the fine particles. , It is considered to be densely packed. Further, the surface roughness Ra of the coating film can be made extremely low by the above-mentioned dense filling in addition to the small cumulative 50% volume particle size. It is considered that, as a result, the gloss value, which is an index indicating the metal-like design, can be increased, and excellent metal-like design can be exhibited.

<Scaly indium particles>
The indium particles used in the active energy ray-curable ink of the present invention are scaly particles. The scaly particles may also be referred to as flaky particles, flat particles, flake-like particles, and the like.
In the present invention, the scaly particles mean particles having a substantially flat surface and having a thickness substantially uniform in the direction perpendicular to the substantially flat surface. Further, the scaly particles mean particles having a shape in which the thickness is very thin and the length of a substantially flat surface is very long. The length of the substantially flat surface is the diameter of a circle having the same projected area as the projected area of the scaly particles.
The shape of the substantially flat surface is not particularly limited and may be appropriately selected depending on the intended purpose. For example, substantially rectangular, approximately square, approximately circular, approximately elliptical, approximately triangle, approximately quadrangle, approximately pentagon, approximately. Examples include polygons such as hexagons, substantially heptagons, and approximately octagons, and random indefinite shapes. Among these, a substantially circular shape or a substantially elliptical shape is preferable.
The scaly indium particles may have one layer or two or more layers may be laminated to form primary particles. Further, the primary particles of scaly indium may be aggregated to form secondary particles.
The scaly indium particles are made of indium having a purity of 95% or more and may contain a trace amount of impurities, but alloys with other metals are not included.

The cumulative 50% volume particle size D ₅₀ of the scaly indium particles is preferably 0.7 μm or less, more preferably 0.6 μm or less, further preferably 0.5 μm or less, and particularly preferably 0.4 μm or less.
When the cumulative 50% volume particle size D ₅₀ is 0.7 μm or less, the surface roughness Ra of the coating film is lowered, and the gloss value, which is an index showing the metal-like design, can be increased, resulting in an excellent metal-like design. Can express sex. There is an advantage.
The cumulative 50% volume particle diameter (D ₅₀ ) is a particle size corresponding to 50% of the cumulative volume distribution of the particle size distribution curve obtained by the laser diffraction method, and it is assumed that the non-spherical indium particles are perfect spheres. This is the particle size of the indium particles as measured. However, the actual indium particles are 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 indium particles.
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 indium particles is preferably 60 nm or less, more preferably 50 nm or less, still more preferably 45 nm or less. When the average thickness is 60 nm or less, the surface roughness Ra of the coating film is lowered, the gloss value which is an index showing the metal-like design property can be increased, and the excellent metal-like design property can be exhibited. There is.
The average thickness of the scaly indium particles in the present invention is defined as the length of the shortest portion of the scaly indium particles in the three-dimensional direction.
The average thickness can be obtained from, for example, scanning electron microscope (SEM) observation, fluorescent X-ray analysis (XRF), ultraviolet-visible spectroscopy, etc., and the average thickness of indium particles is the average vapor deposition of an indium vapor deposition film. Same as thickness.
When using a scanning electron microscope (SEM) observation, the average thickness of the indium particles is obtained by observing the cross section using a scanning electron microscope (SEM) and measuring the thickness of the indium particles at 5 to 10 points. It is the value that was set.
When X-ray fluorescence analysis (XRF) is used, the thickness of the indium vapor deposition film can be measured by quantitative analysis of XRF by creating a calibration curve for the thickness and the X-ray intensity of indium. That is, the average thickness of the indium particles can be easily measured.
When the ultraviolet-visible spectroscopy method is used, the reflectance of the indium-deposited film can be measured by an ultraviolet-visible spectrophotometer, and the film thickness can be calculated from the obtained spectrum.

_{The ratio (D 50} (nm) / average thickness (nm)) of the cumulative 50% volume particle size (D ₅₀ ) (nm) to the average thickness (nm) is preferably 50 or more, more preferably 100 or more. preferable.
_{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 a fluorescent X-ray analysis method. It is a ratio calculated by dividing by the average thickness obtained from. Therefore, _{the ratio of "D 50} (nm) / average thickness (nm)" is a ratio different from a parameter generally called an aspect ratio.

The scaly indium particles preferably have an organic substance layer on at least a part of the surface thereof, preferably on one surface on the release layer side. The organic substance layer is a layer of organic matter used as a release layer in the method for producing scaly indium particles. This organic layer has a function of suppressing the aggregation of the scaly indium particles, and exerts a sufficient function even if it is formed on a part of the surface of the scaly indium particles instead of the entire surface.
Having an organic layer on at least a part of the surface of the scaly indium particles means that gas chromatography-mass spectrometry (GC / MS), TG-DTA / DSC, and scanning transmission electron microscope (CS) It can be analyzed by Scanning Transmission Electron Microscope-Energy Dispersive X-ray Analysis (STEM-EDX).
Examples of the material of the organic material layer include the same materials as those of the organic material constituting the release layer described later.

<Manufacturing method of scaly indium particles>
The method for producing scaly indium particles includes a release layer forming step, a vacuum deposition step, and a peeling step, and further includes other steps as necessary.

<< Release layer forming process >>
The release layer forming step is a step of providing a release layer on the base material, and is carried out by the release layer forming means.

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

-Release layer-
As the release layer, various organic substances that can be dissolved in the subsequent release step can be used. Further, if the organic material constituting the release layer is appropriately selected, the organic substance adhering to and remaining on the adhering surface of the island-shaped structural film can function as a protective layer for the scaly indium particles, which is preferable.
The protective layer has a function of suppressing aggregation, oxidation, elution of scaly indium particles into a solvent, and the like. In particular, it is preferable to use the organic substance used for the release layer as a 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 acid co-weight. Examples thereof include coalescence, modified nylon resin, rosin resin, polyvinyl butyralidone, urethane resin, polyester resin, polyether resin, and alkyd resin. These may be used alone or in combination of two or more. Among these, cellulose acetate butyrate (CAB) is preferable because of its high function as a 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. , 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 thereof include a method, a curtain coating method, a slide coating method, a die coating method, a spray coating method, an organic vapor deposition method, and a CVD method. These may be used alone or in combination of two or more.

<< Vacuum deposition process >>
The vacuum deposition step is a step of vacuum-depositing a metal layer containing scaly indium particles on the release layer, and is carried out by a vacuum deposition means.

The average vapor deposition thickness of the metal layer containing the scaly indium particles is preferably 60 nm or less, more preferably 55 nm or less, further preferably 50 nm or less, and particularly preferably 45 nm or less. The average vapor deposition thickness of the metal layer containing the scaly indium particles is the same as the average thickness of the indium particles.
When the average vapor deposition thickness of the metal layer is 60 nm or less, the surface roughness Ra of the coating film is lowered, and the gloss value, which is an index showing the metal-like designability, can be increased, resulting in excellent metal-like designability. It has the advantage of being able to be expressed.
The average vapor deposition thickness is determined by, for example, using a fluorescent X-ray analysis method (XRF), an ultraviolet-visible spectrophotometer, or using a scanning electron microscope (SEM) after forming scaly indium particles. Observation is performed, the thickness of the scaly indium particles at 5 to 10 points is measured, and the average value is the average value.

The metal layer is preferably an island-like structural film. The island-shaped structural film can be formed by various methods such as a vacuum vapor deposition method, a sputtering method, and a plating method. Among these, the vacuum vapor deposition method is preferable.
The vacuum vapor deposition method is preferable to the plating method in that it can form a film on a resin substrate, does not generate waste liquid, etc., and it can increase the degree of vacuum and has a high film formation rate (deposited rate). Preferable over the method.
The vapor deposition rate in the vacuum vapor deposition method is preferably 10 nm / sec or more, and more preferably 10 nm / sec or more and 80 nm / sec or less.

When a thin film of indium particles is formed on the release layer, individual indium atoms flying from the vapor deposition source lose energy by interacting with the base material and are adsorbed on the base material when they reach the surface of the base material. It diffuses on the surface of the material, collides with indium atoms, and bonds to form a three-dimensional nucleus. When the number of atoms exceeds a certain critical value, the formed three-dimensional nuclei merge with the adjacent three-dimensional nuclei and grow into islands to form an island-like structural film due to the acquisition of surface-diffusing atoms on the substrate. Form. Such an island-shaped structural film retains the morphology of the film when it is on the substrate, but when it is peeled off from the substrate, it splits and individual islands become indium particles.
The shape of the finally obtained indium particles, the cumulative 50% volume particle size, and the volume ratio of ultrafine particles to fine particles (V1 / V2) × 100 are the average film thickness of the island-shaped structural film (hereinafter, simply “thickness”). It can be controlled by changing). Since the average film thickness of the island-shaped structural film can be measured by utilizing the interference of the film during film formation, the desired shape and size can be obtained by obtaining the relationship with the shape and size of the indium particles in advance. Indium particles having a scent can be easily obtained. In addition, the operating factors that affect the shape of indium particles, the cumulative 50% volume particle diameter, and the volume ratio of ultrafine particles to fine particles include the film formation method and the energy of indium flying to the substrate (kinetic energy, temperature, etc.). ), Surface free energy of the base material and the release layer, cooling method / temperature of the base material, film formation rate, pressure at the time of film formation, and the like.

<< Peeling process >>
The peeling step is a step of peeling the metal layer by dissolving the peeling layer, and is carried out by a peeling means.
The solvent capable of dissolving the release layer is not particularly limited as long as it is a solvent capable of dissolving the release layer, and can be appropriately selected depending on the intended purpose. However, it is used as it is as an organic solvent for active energy ray-curable ink. Those that can be used are preferable.

Examples of the solvent capable of dissolving the release layer include alcohols such as methanol, ethanol, propanol, isopropanol, butanol, octanol, dodecanol, ethylene glycol and propylene glycol; ethers such as tetrahydrone; acetone, methyl ethyl ketone, acetyl acetone and the like. Ketones; 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, triethylene 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 acetate and other glycol ethers; phenols, cresol and other phenols; pentane , Hexane, heptane, octane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, octadecane, octadecene, benzene, toluene, xylene, trimesin, nitrobenzene, aniline, methoxybenzene and other aliphatic or aromatic hydrocarbons; dichloromethane, chloroform, trichloroethane , Aliphatic or aromatic chloride hydrocarbons such as chlorobenzene and dichlorobenzene; sulfur-containing compounds such as dimethylsulfoxide; nitrogen-containing compounds such as dimethylformamide, dimethylacetamide, acetonitrile, propionitrile and benzonitrile. These may be used alone or in combination of two or more.

By dissolving the release layer, the island-like structural film is separated from the base material, the island-like structural film is split, and individual islands become indium particles. As a result, a scaly indium particle dispersion can be obtained without going through a pulverization step, but pulverization and classification may be performed as necessary. When the primary particles of the scaly indium particles are agglomerated, they may be crushed if necessary.
Further, if necessary, various treatments may be performed for recovering the scaly indium particles and adjusting the physical properties. For example, the particle size of the scaly indium particles may be adjusted by classification, the scaly indium particles may be recovered by a method such as centrifugation or suction filtration, or the solid content concentration of the dispersion may be adjusted. Further, the solvent may be replaced, or the viscosity may be adjusted by using an additive. A dispersant may be added, but if an appropriate organic substance is selected as the release layer, a brilliant pigment dispersion liquid composed of scaly indium particles having good dispersibility can be obtained. It does not have to be added.

<< Other processes >>
Examples of the other steps include a step of taking out the peeled metal layer as a dispersion liquid, a step of recovering the island-shaped metal layer as scaly indium particles from the dispersion liquid, and the like.

The content of the scaly indium particles is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 3% by mass or more, and 4% by mass, based on the total amount of the active energy ray-curable ink. More than 80% by mass is particularly preferable, 5% by mass or more and 60% by mass or less is more preferable, 5% by mass or more and 40% by mass or less is particularly preferable, and 5% by mass or more and 20% by mass or less is most preferable. If the content is less than 0.1% by mass, the glossiness of the cured coating film may be lowered. When the content is 80% by mass or less, the ink can be more suitable for printing, which is preferable.
The suitable content of the scaly indium particles in the ink varies depending on the method of applying the active energy ray-curable ink and can be appropriately selected. For example, in the case of the bar coating method and the spin coating method, 5 mass is used. % Or more and 80% by mass or less are preferable. In the case of the inkjet method, it is preferably 1% by mass or more and 20% by mass or less.

<Polymerizable compound>
The polymerizable compound is a compound that undergoes a polymerization reaction by active energy rays (ultraviolet rays, electron beams, etc.) and is cured.
The active energy ray-curable ink of the present invention preferably contains a monofunctional monomer and a polyfunctional monomer as the polymerizable compound, and preferably contains an oligomer if necessary. It is preferable to include a monofunctional monomer and a polyfunctional monomer because it is possible to achieve both a viscosity suitable for printing and a curing rate.

-Monofunctional monomer-
The monofunctional monomer means a polymerizable monomer having one ethylenically unsaturated double bond.
Examples of the polymerizable monomer having one ethylenically unsaturated double bond include phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobolonyl (meth) acrylate, and 2-hydroxyethyl (meth) acrylate. 4-Hydroxybutyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isooctyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 2-ethoxy Ethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydixyl ethyl (meth) acrylate, ethyl diglycol (meth) ) Acrylate, Cyclic Trimethylol Propaneformal Mono (Meta) Acrylate, Imid (Meta) Acrylate, Isoamyl (Meta) Acrylate, Ethoxysuccinic Acid (Meta) Acrylate, Trifluoroethyl (Meta) Acrylate, ω-carboxypolycaprolactone Mono ( Meta) acrylate, N-vinylformamide, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, methylphenoxyethyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, Tribromophenyl (meth) acrylate, ethoxylated tribromophenyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, (meth) acryloylmorpholine, phenoxydiethylene glycol (meth) acrylate, vinyl caprolactam, vinyl pyrrolidone, 2-hydroxy- 3-Phenoxypropyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, stearyl (meth) acrylate, diethylene glycol monobutyl ether (meth) acrylate, Lauryl (meth) acrylate, isodecyl (meth) acrylate, 3,3,5-trimethylcyclohexanol (meth) acrylate, isooctyl (meth) acrylate, octyl / decyl (meth) acrylate, tridecyl (meth) acrylate Acrylate, caprolactone (meth) acrylate, ethoxylated (4) nonylphenol (meth) acrylate, methoxypolyethylene glycol (350) mono (meth) acrylate, methoxypolyethylene glycol (550) mono (meth) acrylate and the like can be mentioned. These may be used alone or in combination of two or more.

The content of the monofunctional monomer is preferably 20% by mass or more and 80% by mass or less, and 50% by mass or more and 70% by mass or less, based on the total amount of the polymerizable compound (total amount of the monofunctional monomer and the polyfunctional monomer). Is more preferable. If the content is less than 20% by mass, the viscosity becomes high and it may not be suitable for printing. On the other hand, if the content exceeds 80% by mass, the curing rate becomes slow and may not be suitable for printing.

-Polyfunctional monomer-
The polyfunctional monomer means a monomer having two or more ethylenically unsaturated double bonds, and preferably has two or more and ten or less ethylenically unsaturated double bonds.
Examples of the polyfunctional monomer include hexadiol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, polyethylene glycol di (meth) acrylate, and dipropylene glycol di (meth) acrylate. , Tripropylene glycol tri (meth) acrylate, neopentyl glycol di (meth) acrylate, bispentaerythritol hexa (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (Meta) acrylate, ethoxylated 1,6-hexanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate , Tetraethylene glycol di (meth) acrylate, 2-n-butyl-2-ethyl 1,3-propanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, 1,3-butylene glycol di (Meta) acrylate, trimethylolpropane hydroxypivalate (meth) acrylate, ethoxylated trimethylolpropane di (meth) acrylate, ethoxylated trimethylolpropane di (meth) acrylate, neopentyl glycol-modified trimethylolpropane di (meth) acrylate , Stearate-modified pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, tetramethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, pentaerythritol tetra (meth) acrylate, caprolactone-modified trimethylol Propanetri (meth) acrylate, propoxylate glyceryltri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) Acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, dipentaerythritol hydroxypenta (meth) acrylate, neopentyl glycol oli Go (meth) acrylate, 1,4-butanediol oligo (meth) acrylate, 1,6-hexanediol oligo (meth) acrylate, trimethylolpropane oligo (meth) acrylate, pentaerythritol oligo (meth) acrylate, neo ethoxylated Pentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, ethoxylated trimethyl propantri (meth) acrylate, propoxylated trimethylol propanthry (meth) acrylate, etc. Can be mentioned. These may be used alone or in combination of two or more.

The content of the polyfunctional monomer is preferably 20% by mass or more and 80% by mass or less, and 30% by mass or more and 50% by mass or less, based on the total amount of the polymerizable compound (total amount of the monofunctional monomer and the polyfunctional monomer). Is more preferable. If the content is less than 20% by mass, the curing rate becomes slow and may not be suitable for printing. On the other hand, if the content exceeds 80% by mass, the viscosity becomes high and it may not be suitable for printing.

− Oligomer −
Examples of the oligomer include those having an ethylenically unsaturated double bond, and a polyfunctional oligomer having two or more ethylenically unsaturated double bonds is preferable, and specifically, an aromatic urethane oligomer and an aliphatic urethane. Examples include oligomers, epoxy acrylate oligomers, polyester acrylate oligomers, and other special oligomers.
As the oligomer, an appropriately synthesized oligomer may be used, or a commercially available product may be used. Examples of the commercially available products include UV-2000B, UV-2750B, UV-3000B, UV-3010B, UV-3200B, UV-3300B, UV-3700B, UV-6640B, UV- of Nippon Synthetic Chemical Industry Co., Ltd. 8630B, UV-7000B, UV-7610B, UV-1700B, UV-7630B, UV-6300B, UV-6640B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7630B, UV-7640B, UV-7650B, UT-5449, UT-5454; CN902, CN902J75, CN929, CN940, CN944, CN944B85, CN959, CN961E75, CN961H81, CN962, CN963, CN963A80, CN963B80, CN963E75, CN963B80, CN963E75 CN965, CN965A80, CN966, CN966A80, CN966B85, CN966H90, CN966J75, CN968, CN969, CN970, CN970A60, CN970E60, CN971, CN971A80, CN971J75, CN972, CN973, CN973A80, CN973 CN981, CN981A75, CN981B88, CN982, CN982A75, CN982B88, CN982E75, CN983, CN984, CN985, CN985B88, CN986, CN998, CN991, CN992, CN994, CN996, CN997, CN999, CN9001, CN9001 CN9008, CN9009, CN9010, CN9011, CN9013, CN9018, CN9019, CN9024, CN9025, CN9026, CN9028, CN9029, CN9030, CN9060, CN9165, CN9167, CN9178, CN9290, CN9782, CN9783, CN9788, CN9893; EBECRYL210, EBECRYL220, EBECRYL230, EBECRYL270, KRM8200, EBECRYL5129, EBECRYL8210, EBECRYL8301, EBECRYL8804, EBECRYL8807, EBECRYL9260, KRM7735, KRM8296, KRM8452, EBECRYL4858, EBECRYL8402, EBECRYL9270, EBECRYL8311, EBECRYL8701 and the like. These may be used alone or in combination of two or more.

<Polymerization initiator>
The active energy ray-curable ink of the present invention preferably contains a polymerization initiator.
The polymerization initiator may be any one capable of generating active species such as radicals and cations by the energy of active energy rays and initiating the polymerization of a polymerizable compound (monomer or oligomer).
As the polymerization initiator, known radical polymerization initiators, cationic polymerization initiators, base generators and the like can be used alone or in combination of two or more. Among these, it is preferable to use a radical polymerization initiator.
The content of the polymerization initiator is preferably 0.1% by mass or more and 20% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less with respect to the total amount of the active energy ray-curable ink.
Examples of the radical polymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, and the like. Examples thereof include ketooxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.
Further, in addition to the above-mentioned polymerization initiator, a polymerization accelerator (sensitizer) can also be used in combination. The polymerization accelerator is not particularly limited, but for example, trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, -2-ethylhexyl p-dimethylaminobenzoate, N, Amine compounds such as N-dimethylbenzylamine and 4,4'-bis (diethylamino) benzophenone are preferable, and the content thereof may be appropriately set according to the polymerization initiator used and the amount thereof.

<Organic solvent>
The active energy ray-curable ink of the present invention preferably contains an organic solvent.
The organic solvent is not particularly limited, and an organic solvent used for peeling the scaly indium particles can be used, for example, polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, and the like. Examples thereof include nitrogen heterocyclic compounds, amides, amines and sulfur-containing compounds. These may be used alone or in combination of two or more.

Examples of alcohols include alcohols such as methanol, ethanol, propanol, isopropanol, butanol, octanol, dodecanol, ethylene glycol and propylene glycol; ethers such as tetrahydrone; ketones such as acetone, methyl ethyl ketone and acetyl acetone; methyl acetate. , Ethyl acetate, butyl acetate, phenyl acetate and other esters, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4 -Butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4- Pentandiol, 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexane Diol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanediol, 1,2,3-butanetriol, 2,2,4- Examples thereof include trimethyl-1,3-pentanediol.

Examples of polyhydric 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, propylene glycol monomethyl ether, and propylene glycol monoethyl. Examples include ether.

Examples of the polyhydric alcohol aryl ether 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 so on.
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 amines include monoethanolamine, diethanolamine, triethylamine and the like.
Examples of sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol and the like.

<Other ingredients>
The active energy ray-curable ink of the present invention may contain other known components, if necessary. The other components are not particularly limited, but are, for example, surfactants, polymerization inhibitors, coloring materials, leveling agents, antifoaming agents, fluorescent whitening agents, penetration promoters, wetting agents (moisturizing agents), and fixing agents. Examples thereof include agents, viscosity stabilizers, fungicides, preservatives, antioxidants, ultraviolet absorbers, chelating agents, pH adjusters, thickeners and the like.

The active energy ray-curable ink of the present invention can be produced by using the above-mentioned various components, and the preparation means and conditions thereof are not particularly limited. For example, using a mixing device, scaly indium particles and a polymerizable compound can be produced. , A polymerization initiator, and other components are added in a predetermined amount and mixed to prepare the mixture.

(Curing coating film)
The cured coating film of the present invention is a cured product of a coating film obtained by applying the active energy ray-curable ink of the present invention.

The cured coating film has a difference (Gs20 ° −Gs60 °) of 150 or more and a ratio (Gs20 °) between a gloss value (Gs20 °) at an incident angle of 20 ° and a gloss value (Gs60 °) at an incident angle of 60 °. / Gs60 °) preferably satisfies at least one of 1.3 or more, a difference (Gs20 ° −Gs60 °) of 250 or more, and a ratio (Gs20 ° / Gs60 °) of at least 1.5 or more. It is more preferable to satisfy at least one of a difference (Gs20 ° −Gs60 °) of 350 or more and a ratio (Gs20 ° / Gs60 °) of 1.7 or more.
Here, the gloss value (Gs 20 °) at an incident angle of 20 ° indicates a reflection intensity close to that of a specular reflection component. The gloss value (Gs60 °) at an incident angle of 60 ° indicates a reflection intensity close to that of the diffusion component.

The difference (Gs20 ° -Gs60 °) indicates the mapping property, and the larger the difference (Gs20 ° -Gs60 °) between the regular reflection component (Gs20 °) and the diffusion component (Gs60 °), the more regular reflection of the incident light beam. Since it can be said that it contributes to the glossiness of the above, the larger the difference (Gs20 ° −Gs60 °), the more specular the image obtained on the printed surface is and the higher the mapability is, which is preferable.

The ratio (Gs20 ° / Gs60 °) shows mirror glossiness, and a mirror surface can be obtained by depositing a metal such as aluminum or silver on a smooth film or glass. At this time, the regular reflection component (G20) of glossiness is large. Since the diffuse reflection component (Gs20 °) becomes smaller, the ratio (Gs20 ° / Gs60 °) is approximately 2.
On the other hand, those with low specular gloss have both a normal reflection component (Gs20 °) and a diffuse reflection component (Gs20 °) of glossiness, but the regular reflection component (Gs20 °) becomes smaller and the ratio (Gs20 ° /). Gs60 °) is approximately 1. In other words, it can be said that the higher the mirror glossiness, the larger the ratio (Gs20 ° / Gs60 °), and the lower the mirror glossiness, the smaller the ratio (Gs20 ° / Gs60 °).
Here, the gloss value of the cured coating film can be measured using a gloss meter, for example, by a parallel light method based on JIS Z8741 "Mirror glossiness-measurement method", with incident angles of 20 ° and 60 °. it can.

The cured coating film preferably has an L ^* value (total reflection) of 75 or more, an L ^* value (diffuse reflection) of 40 or less, and an L ^* value (specular reflection) of 35 or more in the CIE Lab color system. No.
^{When the L *} value (total reflection), L ^* value (diffuse reflection), and L ^* value (specular reflection) of the CIE Lab color system are in the above numerical range, excellent metal design (high gloss) Value) can be played.
^{The L *} value (total reflection), L ^* value (diffuse reflection), and L ^* value (specular reflection) of the CIE Lab color system are in the wavelength range of 360 nm to 740 nm and the incident angle 8 using a specular colorimeter. It can be calculated from the reflection spectrum of °.

The cured coating film of the present invention is formed by applying the active energy ray-curable ink of the present invention onto a substrate to form a coating film, and irradiating the coating film with active energy rays to cure the coating film.

-Base material-
The base material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, or a composite material thereof may be used. Can be mentioned. Among these, plastic is preferable from the viewpoint of workability.

-Granting method-
The method for applying the active energy ray-curable ink of the present invention is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a spin coating method, an inkjet method, a spray method, a screen coating method, or an offset coating method. , Blade coat method, gravure coat method, gravure offset coat method, bar coat method, roll coat method, knife coat method, air knife coat method, comma coat method, U comma coat method, AKKU coat method, smoothing coat method, micro gravure coat method Examples thereof include a method, a reverse roll coating method, a 4-roll coating method, a 5-roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and a drip coating method. These may be used alone or in combination of two or more. Among these, the spin coating method, the inkjet method, the bar coating method, and the drip coating method are particularly preferable from the viewpoint of being able to realize excellent metallic colors.

-Curing-
Curing is a step of irradiating the coating film with active energy rays to cure the coating film.
As the active energy ray, in addition to ultraviolet rays, if it can impart the energy necessary for advancing the polymerization reaction of the polymerizable component in the ink, such as electron beam, α ray, β ray, γ ray, and X ray. Well, there is no particular limitation. In particular, when a high-energy light source is used, the polymerization reaction can proceed without using a polymerization initiator.

The light source of the active energy ray is not particularly limited and may be appropriately selected. Examples thereof include a mercury lamp, a metal halide lamp, and a UV-LED lamp.
The mercury lamp is a quartz glass arc tube filled with high-purity mercury (Hg) and a small amount of rare gas, and has a main wavelength of 365 nm and efficiently emits ultraviolet rays of 254 nm, 303 nm, and 313 nm. It emits light and has a high output of short-wavelength ultraviolet rays.
The metal halide lamp is a metal halide lamp in which a metal is encapsulated in the form of a halide in addition to mercury. It emits an active energy ray spectrum over a wide range from 200 nm to 450 nm, and is 300 nm or more and 450 nm or less as compared with a mercury lamp. It is characterized by a high output of long-wavelength ultraviolet rays.
The UV-LED lamp has the characteristics that the environmental load can be reduced, the apparatus can be made compact without generating ozone, and the active energy ray-curable ink of the present invention can be cured by the LED method having a long life and low power consumption. It is preferable as a lamp to be used when the light is used.

<Use>
Since the active energy ray-curable ink and the cured coating film of the present invention have excellent metal-like design properties (high gloss value) as compared with the conventional active energy ray-curable ink using scaly aluminum particles. Widely used in various fields, for example, bright inks for inkjet or other printing, bright paints for painting in applications such as automobile interior / exterior members, home appliances, building materials, conductive pastes, decorative films, for 3D printers, etc. It is applied to metal-like filaments, melt-extruded, and metal-like design sheets and films in the casting method.

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

(Comparative Manufacturing Example 1)
<Preparation of scaly aluminum particles>
A solution containing 5% by mass of cellulose acetate butyrate (CAB) is applied on a polyethylene terephthalate (PET) film having an average thickness of 12 μm by a gravure coating method, dried at 110 ° C. or higher and 120 ° C. or lower, and a release layer is formed. Was formed. The amount of cellulose acetate butyrate (CAB) applied was 0.06 g / m ² ± 0.01 g / m ² . An aluminum vapor deposition film having an average vapor deposition thickness of 20 nm was formed on the release layer by a high-frequency induction heating / vacuum vapor deposition method at a vapor deposition rate of 40 nm / sec.
Next, butyl acetate was sprayed on the surface of the PET film on which the release layer and the aluminum vapor deposition film were formed to dissolve the release layer, and the aluminum vapor deposition film was scraped off with a doctor blade. The obtained aluminum particles were scaly.
Next, the obtained mixture of scaly aluminum particles and butyl acetate was pulverized using a fine pulverizer until it became primary particles. From the above, scaly aluminum particles of Comparative Production Example 1 were obtained.

(Comparative Manufacturing Example 2)
In Comparative Production Example 1, a dispersion of scaly aluminum particles of Comparative Production Example 2 was prepared in the same manner as in Comparative Production Example 1 except that an aluminum vapor deposition thin film having an average vapor deposition thickness of 40 nm was formed at a vapor deposition rate of 40 nm / sec. Obtained.

(Manufacturing Example 1)
<Preparation of scaly indium particles>
A solution containing 5% by mass of cellulose acetate butyrate (CAB) is applied on a polyethylene terephthalate (PET) film having an average thickness of 12 μm by a gravure coating method, dried at 110 ° C. or higher and 120 ° C. or lower, and a release layer is formed. Was formed. The amount of cellulose acetate butyrate (CAB) applied was 0.06 g / m ² ± 0.01 g / m ² .
Next, an indium-deposited film having an average vapor deposition thickness of 35 nm was formed on the release layer by a high-frequency induction heating / vacuum vapor deposition method at a vapor deposition rate of 30 nm / sec. The average vapor deposition thickness of the indium-film-deposited thin film is an average value obtained by observing the cross section using a scanning electron microscope (SEM) and measuring the thickness of the in-film-deposited thin film at five locations. The results are shown in Table 1. This average vapor deposition thickness is the same as the average thickness of the indium particles (hereinafter, the same applies).
Next, propylene glycol monomethyl ether (PGM) was sprayed on the PET film surface on which the release layer and the indium-deposited film were formed to dissolve the release layer, and the indium-deposited film was scraped off with a doctor blade. The obtained indium particles were scaly.
Next, the obtained mixture of scaly indium particles and propylene glycol monomethyl ether (PGM) was crushed using an ultrasonic homogenizer until it became primary particles. From the above, scaly indium particles of Production Example 1 were obtained.

(Manufacturing Example 2)
In Production Example 1, a dispersion of scaly indium particles of Production Example 2 was obtained in the same manner as in Production Example 1 except that an indium-deposited thin film having an average vapor deposition thickness of 37 nm was formed at a vapor deposition rate of 30 nm / sec.

(Manufacturing Example 3)
In Production Example 1, a dispersion of scaly indium particles of Production Example 3 was obtained in the same manner as in Production Example 1 except that an indium-deposited thin film having an average vapor deposition thickness of 43 nm was formed at a vapor deposition rate of 35 nm / sec.

(Manufacturing Example 4)
In Production Example 1, a dispersion of scaly indium particles of Production Example 4 was obtained in the same manner as in Production Example 1 except that an indium-deposited thin film having an average vapor deposition thickness of 51 nm was formed at a vapor deposition rate of 35 nm / sec.

(Manufacturing Example 5)
In Production Example 1, a dispersion of scaly indium particles of Production Example 5 was obtained in the same manner as in Production Example 1 except that an indium-deposited thin film having an average vapor deposition thickness of 55 nm was formed at a vapor deposition rate of 35 nm / sec.

(Manufacturing Example 6)
In Production Example 1, a dispersion of scaly indium particles of Production Example 6 was obtained in the same manner as in Production Example 1 except that an indium-deposited thin film having an average vapor deposition thickness of 66 nm was formed at a vapor deposition rate of 30 nm / sec.

<Formation of coating film>
Each of the obtained scaly particles was dispersed in a dispersion solvent (propylene glycol monomethyl ether (PM) and water in a mass ratio of 1: 1) to adjust the solid content to 2.5% by mass, and the scaly particle dispersion was prepared. Was prepared.
Each scaly particle dispersion was used to form a coating film on a glass substrate under the condition of a rotation speed of 500 rpm using a spin coater (MS-A150) manufactured by Mikasa Sports Co., Ltd.

Next, various characteristics of each of the obtained scaly particles and the coating film were evaluated as follows. The results are shown in Tables 1 to 3.

<Cumulative 50% volume particle size (D ₅₀ ) of each scaly particle, peak top of particle size, and volume ratio>
For the cumulative 50% volumetric particle size (D ₅₀ ) of each scaly particle, a laser diffraction / scattering type particle size distribution measuring device (device name: Laser Micron Sizer LMS-2000e, Seishin Co., Ltd., wet dispersion unit) was used. Then, using ethanol (trade name: Ekinen F-1, manufactured by Nippon Alcohol Sales Co., Ltd., refractive index: 1.360) as a dispersion medium, send a sample containing scaly particles to the measurement cell while stirring with a stirrer, and scaly. The volume particle size distribution of the shaped particles was measured, the volume of each peak was determined, and the volume ratio (V1 / V2) × 100 was determined. FIG. 1 shows the results of volume-based particle size distribution in the scaly indium particles of Production Examples 2 to 6 and the scaly aluminum particles of Comparative Production Example 2. The scaly indium particles of Production Examples 1 to 6 have a bimodal distribution, whereas the scaly aluminum particles of Comparative Production Examples 1 and 2 have only one peak and have a bimodal distribution. I don't have it.

<Peak area and area ratio>
For each scaly particle, the sum of the trapezoids in each subsection was approximated as a definite integral of the graph of the particle size distribution in which the X-axis is the particle size and the Y-axis is the volume%. That is, S = Σ1 / 2 × {y (i) + y (i + 1)} × {log (x (i + 1))-log (xi), where each point on the graph is (xi, yi) 0 ≦ i ≦ n. }, The area of each peak was obtained, and the area ratio (S1 / S2) × 100 was obtained.

<Gloss value>
The mirror glossiness was measured for each coating film. The gloss value is measured using a gloss meter (VG-7000, manufactured by Nippon Denshoku Kogyo Co., Ltd.) with a parallel light method based on JIS Z8741 "Mirror gloss-measurement method", and the incident angle is 20 ° (Gs20 °). And the measurement was performed at an incident angle of 60 ° (Gs60 °).

<Hue (L ^* value, a ^* value, b ^* value)>
Each coating film was calculated from an ultraviolet-visible near-red spectrophotometer (SolidSpec-3700, manufactured by Shimadzu Corporation), a reflection spectrum having a wavelength region of 300 nm to 800 nm and an incident angle of 5 °. L ^* values referred to herein indicates that of the total reflection of the L ^* value.

<Surface roughness (Ra)>
For each coating film, an arithmetic mean surface roughness Ra in the range of 30 μm × 30 μm was calculated using a scanning probe microscope (AFM, manufactured by Shimadzu Corporation, SPM-9600).

<Storage stability>
Each of the prepared scaly particles was dispersed in a dispersion solvent (PM (propylene glycol monomethyl ether and water in a mass ratio of 1: 1)) to prepare a scaly particle dispersion having a solid content adjusted to 2.5% by mass. The obtained scaly particle dispersion was placed in a glass bottle having a capacity of 30 mL (standard bottle No. 5, manufactured by AS ONE Co., Ltd.), sealed, and allowed to stand in an environment of 60 ° C. for 30 days to measure the appearance and differential pressure. The storage stability was evaluated according to the following criteria. The "differential pressure" was determined from (internal pressure of the glass bottle after the test)-(atmospheric pressure).
[Evaluation criteria]
◯: No change in appearance and differential pressure less than 5 kPa ×: Change in appearance and differential pressure 5 kPa or more

＊表１中の製造例１の「−」は未測定であることを示す。

* “-” In Production Example 1 in Table 1 indicates that the measurement has not been performed.

＊表２中の製造例１の「−」は未測定であることを示す。

* “-” In Production Example 1 in Table 2 indicates that the measurement has not been performed.

＊表３中の製造例１及び比較製造例１の「−」は未測定であることを示す。

* “-” In Production Example 1 and Comparative Production Example 1 in Table 3 indicates that the measurement has not been performed.

Here, in the volume-based particle size distribution showing the relationship between the particle size of the scaly indium particles and the volume ratio of the scaly indium particles in the particle size, the first peak and the particle size are larger than the first peak. The volume V1 of the scaly indium particles at the first peak and the volume V2 of the scaly indium particles at the second peak are expressed by the following equations (V1 / V2). It is preferable that × 100 ≧ 25% is satisfied, and the following formula, (V1 / V2) × 100 ≧ 35%, is satisfied, and it is more preferable that (V1 / V2) × 100 ≧ 50% is satisfied.
By satisfying the following equation, (V1 / V2) × 100 ≧ 25%, the surface roughness Ra of the coating film can be lowered, and the gloss value, which is an index showing the metal-like design, can be increased, which is an excellent metal. There is an advantage that the design can be expressed.

Further, in the volume-based particle size distribution showing the relationship between the particle size of the scaly indium particles and the volume ratio of the scaly indium particles in the particle size, the particle size P1 of the scaly indium particles at the first peak and the first The particle size P2 of the scaly indium particles at the peak of 2 preferably satisfies the following formula, P2 / P1 ≦ 12, more preferably P2 / P1 ≦ 10, further preferably P2 / P1 ≦ 8, and P2 /. P1 ≦ 7 is particularly preferable.
By satisfying the following equation, P2 / P1 ≦ 12, the surface roughness Ra of the coating film can be lowered, the gloss value, which is an index showing the metal-like design, can be increased, and excellent metal-like design can be exhibited. There is an advantage that it can be done.
The particle size P1 of the scaly indium particles at the first peak is preferably 0.075 μm or less.
The particle size P2 of the scaly indium particles at the second peak is preferably 0.75 μm or less, more preferably 0.6 μm or less, still more preferably 0.5 μm or less.

The above (V1 / V2) × 100 and P2 / P1 are obtained by measuring the volume-based particle size distribution showing the relationship between the particle size of the scaly indium particles and the volume ratio of the scaly indium particles in the particle size. You can ask. The volume-based particle size distribution can be measured by a laser diffraction / scattering particle size distribution measuring device or the like.

In the volume-based particle size distribution showing the relationship between the particle size of the scaly indium particles and the volume ratio of the scaly indium particles in the particle size, the area S1 of the scaly indium particles at the first peak and the second peak. The area S2 of the scaly indium particles in the above preferably satisfies the following formula, (S1 / S2) × 100 ≧ 20%, and more preferably satisfies the following formula, (S1 / S2) × 100 ≧ 30%. It is more preferable to satisfy the following formula, (S1 / S2) × 100 ≧ 50%, and it is particularly preferable to satisfy the following formula (S1 / S2) × 100 ≧ 70%.
By satisfying the following equation, (S1 / S2) × 100 ≧ 20%, the surface roughness Ra of the coating film can be lowered, and the gloss value, which is an index showing the metal-like design, can be increased, which is an excellent metal. There is an advantage that the design can be expressed.

From the results of Tables 1 to 3, the scaly indium particles of Production Examples 1 to 5 having an average thickness of 60 nm or less and a cumulative 50% volume particle size D _{50 satisfying 0.7 μm or less have an average thickness.} a 66 nm, and the cumulative 50% volume particle diameter D ₅₀ compared to the scaly indium particles of production example 6 is 0.78 .mu.m, lower the surface roughness Ra of the coating film, the index of the metallic design property It is clear that the gloss value can be increased and excellent metal-like design can be exhibited.
The average thickness and a cumulative 50% volume particle diameter D ₅₀ from the optimized manufacturing example 1-5 scaly indium particles as, select the scaly indium particles of Production Example 1, in Comparative Production Example 1 It was used in the following examples and comparative examples together with scaly aluminum particles. The same results as those of the scaly indium particles of Production Example 1 were obtained for the scaly indium particles of Production Examples 2 to 5.

(Examples 1 to 17 and Comparative Examples 3 to 5)
<Preparation of active energy ray-curable ink>
Based on the composition and content of Tables 4-1 to 4-4, active energy ray-curable inks of Examples 1 to 17 and Comparative Examples 3 to 5 were prepared by a conventional method.

Details of each component in Tables 4-1 to 4-4 are as follows.
・ Phenoxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.)
・ Trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.)
-Omnirad 184 (manufactured by BYK Adaptives & Instruments)
-BYK-UV3576 (manufactured by BYK Adaptives & Instruments)
・ Butyl acetate (manufactured by Daishin Chemical Co., Ltd.)
-Propylene glycol monomethyl ether (PGM) (manufactured by Daicel Chemical Industries, Ltd.)
-Scale-like indium particles: Scale-like indium particles prepared in Production Example 1-Scale-like aluminum particles: Scale-like aluminum particles prepared in Comparative Production Example 1.

Next, using the obtained active energy ray-curable inks of Examples 1 to 17 and Comparative Examples 3 to 5, each cured coating film was formed as follows.
Comparative Example 1 is an indium-deposited film formed on a polyethylene terephthalate (PET) film (thickness 75 μm, manufactured by Toyobo Co., Ltd.).
Comparative Example 2 is Roland D. G. It is an indium-deposited film formed on a vinyl chloride printing medium (glossy vinyl chloride, MV-G-18G) manufactured by the company.
Comparative Example 6 is an aluminum-deposited film formed on a polyethylene terephthalate (PET) film (thickness 75 μm, manufactured by Toyobo Co., Ltd.).

<Formation of bar coat cured coating film>
Using the active energy ray-curable inks of Examples 1 to 16 and Comparative Examples 3 to 5, Roland D.I. G. Using a bar coater (# 4, manufactured by Marukyo Giken Co., Ltd.) on vinyl chloride printing media (glossy vinyl chloride, MV-G-18G) manufactured by the company, each ink is applied at room temperature (25 ° C), and EYE Examples 1 to 16 having an average thickness of 3.0 ± 1.0 μm after being cured with an inverter GRANDAGE (ultraviolet irradiation device manufactured by Eye Graphics Co., Ltd.) at ^{a discharge amount of 86.96 W · min / m 2.} And the bar coat cured coating film of Comparative Examples 3 to 5 was formed.
Note that FIG. 2 shows an SEM photograph of the cured coating film containing the scaly indium particles of Example 15 at an inclination angle of 90 °, and FIG. 3 shows an inclination angle of the cured coating film containing the scaly indium particles of Example 15 at an inclination angle of 60 °. SEM photograph, FIG. 4 shows an SEM photograph at an inclination angle of 90 ° of the cured coating film containing the scaly aluminum particles of Comparative Example 4, and FIG. 5 shows an inclination angle of 60 of the cured coating film containing the scaly aluminum particles of Comparative Example 4. SEM photographs at ° are shown respectively.
From FIGS. 2 to 5, the cured coating film containing the scaly indium particles of Example 15 has a higher filling than the cured coating film containing the scaly aluminum particles of Comparative Example 4, and has no particle inclination or curl. It can be seen that it is a cured coating film.

<Formation of inkjet cured coating film>
Using the active energy ray-curable ink of Example 17, printing was performed with a material printer manufactured by Fuji Film Co., Ltd., cured with a UV-LED lamp, and the inkjet of Example 17 having an average thickness of 3.0 μm ± 1.0 μm. A cured coating was formed.

Next, various characteristics of each of the obtained cured coating films and vapor-deposited films were evaluated as follows. The results are shown in Tables 5 to 7.

<Glossiness (visual)>
The glossiness of each of the obtained cured coating films was evaluated according to the following criteria by visually observing the mirror surface condition and the like.
[Evaluation criteria]
5: Gloss with strong reflection 4: Gloss with reflection 3: Gloss with slight reflection 2: Metallic but no gloss 1: No metallic

<Gloss value>
For each of the obtained cured coating film and the thin-film deposition film, the gloss value was measured using the coating film surface and the vapor-deposited surface as measurement surfaces. The gloss value is measured using a gloss meter (VG-7000, manufactured by Nippon Denshoku Kogyo Co., Ltd.) and a parallel light method based on JIS Z8741 "Mirror gloss-measurement method". The gloss value (Gs60 °) at Gs20 °) and the incident angle of 60 ° was measured, and the difference (Gs20 ° −Gs60 °) and the ratio (Gs20 ° / Gs60 °) were calculated from these values.

<L ^* value (total reflection), L ^* value (diffuse reflection), L ^* value (specular reflection)>
For each of the obtained cured coating film and vapor-deposited film, the coating surface and the vapor-deposited surface were used as measurement surfaces, and a spectrocolorimeter (CM-3600A, manufactured by Konica Minolta Japan Co., Ltd.) was used in the wavelength range of 360 nm to 740 nm. , Incident angle 8 ° (total reflection), incident angle 8 ° (diffuse reflection), incident angle 8 ° (normal reflection) were measured, and L ^* value (total reflection), L ^* value (diffuse reflection), And the L ^* value (normal reflection) was calculated.

From the results of Tables 5 to 7, the cured coating film formed by using the active energy ray-curable ink containing the scaly indium particles of Examples 1 to 17 contains the scaly aluminum particles of Comparative Examples 3 to 5. It was found that it has excellent metal-like design (high gloss value) as compared with the cured coating film formed by using the active energy ray-curable ink.
In Examples 1 to 17, the scaly indium particles of Production Example 1 were used, but the cured coating film formed by using the active energy ray-curable ink containing the scaly indium particles of Production Examples 2 to 5 The same results as those of the scaly indium particles of Production Example 1 were obtained.

Claims (8)

An active energy ray-curable ink characterized by containing scaly indium particles. The active energy ray-curable ink according to claim 1, wherein the scaly indium particles have an average thickness of 60 nm or less. The active energy ray-curable ink according to any one of claims 1 to 2, wherein the cumulative 50% volume particle diameter D _{50 of the scaly indium particles is 0.7 μm or less.} The active energy ray-curable ink according to any one of claims 1 to 3, which contains a polymerizable compound. The active energy ray-curable ink according to claim 4, wherein the polymerizable compound contains a monofunctional monomer and a polyfunctional monomer. The active energy ray-curable ink according to any one of claims 1 to 5, further containing a polymerization initiator. A cured coating film which is a cured product of a coating film obtained by applying the active energy ray-curable ink according to any one of claims 1 to 6. The difference (Gs20 ° -Gs60 °) is 150 or more and the ratio (Gs20 ° / Gs60 °) is 1 between the gloss value (Gs20 °) at the incident angle of 20 ° and the gloss value (Gs60 °) at the incident angle of 60 °. .. The cured coating film according to claim 7, which satisfies at least one of 3 or more.

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