JP2022061311A - Image formation method - Google Patents

Abstract

PURPOSE: To provide an image formation method which uses a brilliant ink and can form an image which is excellent in glossiness and scratch resistance.SOLUTION: An image formation method comprises: a step for applying a photo-curing ink to a recording medium for forming a photo-curing ink layer; a step for applying to the photo-curing ink layer, a brilliant ink including a brilliant pigment whose number average particle diameter is 100 nm or smaller, for forming a brilliant ink layer; and a step for radiating light to the photo-curing ink layer, or applying heat for curing the photo-curing ink layer for forming a cured layer of the photo-curing ink.SELECTED DRAWING: None

Description

The present invention relates to an image forming method.

In recent years, the uses of printed recording media (hereinafter, also referred to as printed matter) have been diversified, and printed matter is used in a wide range of applications such as office use and commercial use. With the diversification of applications, in addition to printed matter expressed by conventional color materials such as cyan, magenta, yellow, and black, it is expressed by color materials having unconventional visual effects such as metallic luster. Printed matter is required.

As the color material having a metallic luster, it is preferable to use a silver color material because it can exhibit high luster and image quality. By mixing the silver color material with the conventional color material, it is possible to obtain a printed matter having a full-color image having high glossiness and reproducibility, so that it can be used for various purposes.

Patent Document 1 describes a water-based ink containing metal nanoparticles, a resin, and a polyhydric alcohol, which can enhance the ejection stability of the water-based ink and the brilliance, scratch resistance, and water resistance of the formed image. The ink is disclosed.
Patent Document 2 discloses an inkjet recording method that can suppress ink ejection twist by using silver particles.
Further, Patent Documents 3 and 4 describe a method of forming an image having excellent brilliance by inkjet using an active energy ray-curable ink containing silver particles.

However, when a brilliant ink containing silver particles is used to impart brilliance to an image, the smaller the solid content other than the silver particles, for example, a surfactant or resin, the higher the glossiness is likely to be obtained, while the ink is dispersed. There are problems with stability and image stability. Further, Patent Document 2 relates to a method of ejecting ink by the action of heat energy, that is, a bubble jet (registered trademark) method of inkjet ejection stability.
It is an object of the present invention to provide an image forming method capable of forming an image having excellent glossiness and excellent scratch resistance by using a glittering ink.

The present invention that solves the above problems relates to an image forming method as described below.
A process of applying photocurable ink on a recording medium to form a photocurable ink layer, and
A step of applying a brilliant ink containing a brilliant pigment having a number average particle diameter of 100 nm or less on the photocurable ink layer to form a brilliant ink layer.
A step of curing the photocurable ink layer by irradiating the photocurable ink layer with light or applying heat to form a cured layer of the photocurable ink.
Image forming method having.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an image forming method capable of forming an image having excellent glossiness and excellent scratch resistance by using a glittering ink.

FIG. 1 is a perspective explanatory view showing an example of a recording device. FIG. 2 is a perspective explanatory view showing an example of the main tank.

Hereinafter, embodiments of the present invention will be described, but the following description exemplifies examples of embodiments in the present invention, and does not limit the scope of the claims.

<< Bright ink >>
The glitter ink of the present embodiment contains silver particles, and may contain a polymer compound such as an organic solvent, water, and a resin, and other components, if necessary.
In the present embodiment, the brilliant ink is an ink that imparts brilliance to an image formed by a chromatic color ink or an achromatic color ink. Glitter refers to, for example, a property characterized by the mirror glossiness of an image (Japanese Industrial Standards (JIS) Z8741). The types of brilliance include, for example, brilliance that mirror-reflects light, matte-like brilliance, and the like, each of which can be characterized by the high or low mirror gloss.

In addition, giving brilliance to an image formed by chromatic ink or achromatic ink (hereinafter, also referred to as "image formed by chromatic ink or the like") means that chromatic ink or achromatic ink is applied. It is not limited to the case where the brilliant ink is later applied to the region to exhibit brilliance, but also the case where the chromatic ink or the like is later applied to the region to which the brilliant ink is applied to exhibit brilliance. This includes the case where the brilliant ink, the chromatic color ink, and the like are applied at the same time to exhibit the brilliant property. In other words, as long as the image formed by the chromatic ink or the like has brilliance as a result, the process of forming the image is not particularly limited. The chromatic color ink is an ink containing a chromatic color material, and the achromatic ink is an ink containing an achromatic color material. The achromatic color represents a series of colors from white to gray to black, and the chromatic color represents all colors other than the achromatic color.

<Silver particles>
The glitter ink contains silver particles. In the present embodiment, the "silver particles" are preferably particles containing at least one selected from silver, a silver compound, and a silver alloy, and more preferably particles containing silver. When a silver alloy is used, the other metallic or non-metallic element that can be added to silver is not particularly limited, and is, for example, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, and copper. Etc., and those having a metallic luster are preferable, and those having a white metallic luster are more preferable. The silver particles are metal particles having a high degree of whiteness among various metal particles, and are preferable because various metal colors can be realized by combining with a coloring material of another color or an ink containing a coloring material of another color. Further, silver constituting silver particles is stable even in water because its reactivity with water is weak. As a result, it is possible and preferable to develop a water-based bright ink that can reduce the environmental load. Further, the silver particles include spherical silver particles and flat plate-shaped silver particles as described below, and may contain silver particles having other shapes, if necessary.

-Shape and diameter of silver particles-
The silver particles include silver particles having a diameter of 40 nm or less, but most of the particles having a diameter of 40 nm or less often have a spherical shape. In the present embodiment, the term "spherical" includes the shape of a true sphere and a shape similar to a true sphere such as an ellipsoid. For example, when the particles in the ink are photographed with a transmission microscope (TEM) or the like, the particles in the ink are photographed. It means that the silver particles observed in the unit field of view of the photograph are rounded, and the value obtained by dividing the minimum diameter of the silver particles by the maximum diameter is 0.6 or more and 1.0 or less.

The number average particle diameter (hereinafter, also referred to as “average particle diameter”) of the spherical silver particles is 100 nm or less, and preferably 40 nm or less. Further, the average particle diameter of the spherical silver particles is preferably 5 nm or more. When the average particle diameter of the spherical silver particles is 100 nm or less, the dispersion stability of the spherical silver particles in the glitter ink is improved. In addition, it is possible to improve the glossiness and image quality of the image formed by using the brilliant ink.

In this embodiment, the average particle size of the spherical silver particles is measured as follows. First, 1 to 3 μl of a dispersion containing spherical silver particles or a brilliant ink is collected, and a frozen body is prepared by a high-pressure freezing method. Next, after cutting the frozen body, a carbon replica membrane having a cross section is produced. Furthermore, the replica film is placed on a grid for a transmission microscope (TEM), observed by TEM, the maximum diameter of spherical silver particles in a TEM image in the range of 5 μm × 5 μm is measured, and the arithmetic mean value is calculated as the number. The average particle size.

-Content of silver particles-
The content of the silver particles is preferably 1.0% by mass or more and less than 15.0% by mass, and more preferably 2.0% by mass or more and 13.0% by mass or less with respect to the mass of the brilliant ink. preferable. When the content of the silver particles is 1.0% by mass or more, the glossiness and image quality of the image formed by using the glitter ink can be improved. Further, when it is less than 15.0% by mass, the dispersion stability and the storage stability of the brilliant ink are improved, and for example, the ejection stability in the case of ejection by an inkjet method is improved.

-Surfactant content-
The amount of the surfactant in the present invention represents the total amount of the content of the surfactant added when preparing the ink and the content of the surfactant (dispersant) contained in the silver particle dispersion. When the mass ratio of the surfactant to the total amount of the ink is 0.4% or more and 1.6% or less, the silver particles of the ink can maintain high stability, and further, so-called non-non-form, represented by vinyl chloride and PET. The ink can be uniformly wetted and spread on the permeable medium to form a uniform and highly glossy print layer. As long as the ink is produced within the range of the amount of the surfactant, it is possible to exhibit high glossiness even on a medium having a receiving layer, for example, glossy paper or coated paper.

-Amount of resin-
The amount of the resin in the present invention is the ratio of the solid content mass to the total ink mass. When the content is 0.1% or less, a uniform and highly glossy print layer can be formed on a so-called impermeable medium typified by vinyl chloride or PET. In addition, it is possible to obtain a printed matter that also has the ability to prevent show-through when the media are stacked. From the viewpoint of preventing show-through, the resin content is more preferably 0.05% or more and 0.08% or less.

-Dispersion form of silver particles-
The silver particles are preferably dispersed in a dispersion medium such as water as a silver colloid having a protective colloid attached to the surface. As a result, the dispersibility of the silver particles is improved, and the storage stability of the glitter ink is improved. The silver colloid may be prepared by any method, and can be obtained, for example, by preparing a solution containing silver ions and reducing the silver ions with a reducing agent in the presence of the protective colloid. When producing a silver colloid by these methods, if a surfactant or the like is added at any time before and after the reduction reaction, the dispersion stability of the metal particles is further improved. The protective colloid is PET, which is not particularly limited as long as it is an organic substance that protects the surface of silver particles, but an organic compound having a carboxyl group, a polymer dispersant, and the like are preferable.

--Organic compound with carboxyl group ---
Organic compounds having a carboxyl group include carboxylic acids. The carboxylic acid is not particularly limited as long as it can cover silver particles, and for example, monocarboxylic acids such as aliphatic monocarboxylic acids and aromatic monocarboxylic acids, aliphatic polycarboxylic acids and aromatic polycarboxylic acids, and the like. Examples thereof include hydroxycarboxylic acids (or oxycarboxylic acids) such as polycarboxylic acids, hydroxymonocarboxylic acids and hydroxypolycarboxylic acids. Among these organic compounds having a carboxyl group, hydroxycarboxylic acids such as aliphatic hydroxycarboxylic acids (aliphatic hydroxymonocarboxylic acid and aliphatic hydroxypolycarboxylic acid) are preferable. Among the aliphatic hydroxycarboxylic acids, further, alicyclic hydroxycarboxylic acid (or hydroxycarboxylic acid having an alicyclic skeleton, for example, C6-34 alicyclic hydroxycarboxylic acid such as coli acid, preferably C10-34 fat Acyclic hydroxycarboxylic acid, more preferably C16-30 alicyclic hydroxycarboxylic acid). In particular, polycyclic aliphatic hydroxycarboxylic acids such as cholic acid are preferable because they have a bulky structure and have a large effect of suppressing the aggregation of silver particles.

In addition, these carboxylic acids may form a salt, and may be an anhydride, a hydrate and the like. The carboxylic acid is preferably an organic compound that does not form a salt (particularly, a salt with a basic compound such as a salt with an amine). The organic compound having a carboxyl group may be used alone or in combination of two or more.

The molecular weight of the organic compound having a carboxyl group is, for example, preferably 1000 or less, more preferably 800 or less, and further preferably 600 or less. The pKa value of the organic compound having a carboxyl group is, for example, preferably 1 or more, and more preferably 2 or more.

－－Polymer dispersant －－
The polymer dispersant is not particularly limited as long as it can cover silver particles, but an amphipathic polymer dispersant (or oligomer-type dispersant) can be preferably used. Examples of the polymer dispersant include polymer dispersants usually used for dispersing colorants in the fields of paints and inks. Such dispersants include cellulosic resins (styrene- (meth) acrylic acid copolymer, styrene-maleic anhydride copolymer, etc.) and acrylic resins (methyl (meth) acrylic acid- (meth) acrylic acid. (Copolymer, etc.), water-soluble urethane resin, water-soluble acrylic urethane resin, water-soluble epoxy resin, water-soluble polyester-based resin, cellulose derivative (alkyl cellulose such as ethyl cellulose, alkyl-hydroxyalkyl cellulose such as ethyl hydroxyethyl cellulose, hydroxyethyl cellulose) , Hydroxyalkyl cellulose such as hydroxypropyl cellulose, Carboxyalkyl cellulose such as carboxymethyl cellulose, etc.), Polyvinyl alcohol, Polyalkylene glycol (liquid polyethylene glycol, polypropylene glycol, etc.), Natural polymer (gelatin, dextrin, etc.), Polyethylene sulfonic acid It contains salts, formalin condensates of naphthalene sulfonic acid, and the like. A typical polymer dispersant (amphipathic polymer dispersant) includes a resin (water-soluble resin or water-dispersible resin) containing a hydrophilic unit composed of a hydrophilic monomer.

The polymer dispersant may have a functional group. Examples of such a functional group include an acid group (or an acidic group, for example, a carboxyl group (or an acid anhydride group), a sulfo group (sulfonic acid group), etc.), a hydroxyl group, and the like. These functional groups may be contained in the polymer dispersant alone or in combination of two or more. Of these functional groups, the polymer dispersant preferably has an acid group, particularly a carboxyl group.

When the polymer dispersant has an acid group (carboxyl group, etc.), at least a part or all of the acid groups (carboxyl group, etc.) form a salt (a salt with an amine, a metal salt, etc.). You may be doing it. However, in the present embodiment, a polymer dispersant in which an acid group such as a carboxyl group does not form a salt (particularly, a salt with a basic compound) can be preferably used.

The number average molecular weight of the polymer dispersant is preferably 1500 or more and 100,000 or less, more preferably 2000 or more and 80,000 or less, further preferably 3000 or more and 50,000 or less, and particularly preferably 7,000 or more and 20,000 or less.

Hereinafter, commercially available polymer dispersants (or at least dispersants composed of amphipathic dispersants) will be specifically exemplified. Examples of the polymer dispersant include Solsperse 13240, Solsperse 13940, Solsperse 32550, Solsperse 31845, Solsperse 24000, Solsperse 26000, Solsperse 27000, Solsperse 28000, Solsperse 41090, etc. 160, Disperbic 161, Disperbic 162, Disparbic 163, Disperbic 164, Disparbic 166, Disparbic 170, Disperbic 180, Disperbic 182, Disparbic 184, Disperbic 190, Disparbic 191. Disperbic series such as Disparbic 193, Disparbic 194, Disparbic 2001, Disparbic 2050 [manufactured by BIC Chemie Co., Ltd.]; EFKA-46, EFKA-47, EFKA-48, EFKA-49, EFKA-1501, EFKA- 1502, EFKA-4540, EFKA-4550, Polymer 100, Polymer 120, Polymer 150, Polymer 400, Polymer 401, Polymer 402, Polymer 403, Polymer 450, Polymer 451, Polymer 452, Polymer 453 [manufactured by EFKA Chemical Co., Ltd.] Ajispar series such as Ajispar PB711, Ajispar PAl11, Ajispar PB811, Ajispar PB821, Ajispar PW911 [manufactured by Ajinomoto Co., Ltd.]; Floren DOPA-158, Floren DOPA-22, Floren DOPA-17, Floren TG-700, Floren TG Floren series such as -720W, Floren-730W, Floren-740W, Floren-745W [manufactured by Kyoeisha Chemical Co., Ltd.]; John Krill series such as John Krill 678, John Krill 679, John Krill 62 [manufactured by Johnson Polymer Co., Ltd.] ] And so on.
Of these, Disperbic 190 and Disperbic 194, which are polymer dispersants having an acid group, are preferable.

<Organic solvent>
The organic solvent that can be used in this embodiment preferably has a boiling point of 240 ° C. or lower, but the organic solvent that can be used is not particularly limited, and a water-soluble organic solvent can be used. Examples thereof include ethers such as polyhydric alcohols, polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines and sulfur-containing compounds.
Specific examples of polyhydric alcohols include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, 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- Examples thereof include 1,3-pentanediol and petriol.
Examples of the polyhydric alcohol alkyl ethers include polyhydric alcohol alkyl such as 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. Ethers, etc. can be mentioned.
Examples of 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. 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 amines include monoethanolamine, diethanolamine, triethylamine and the like.
Examples of sulfur-containing compounds include dimethyl sulfoxide, sulfolane, and thiodiethanol.
Examples of other organic solvents include propylene carbonate and ethylene carbonate.
It is preferable to use an organic solvent having a boiling point of 240 ° C. or lower because it not only functions as a wetting agent but also has good drying properties. Among them, 3-methoxy-3-methyl-1-butanol, 1,2-propanediol, and 3-ethyl-3-methylhydroxyoxetane are particularly preferable.

As the organic solvent, a polyol compound having 8 or more carbon atoms and a glycol ether compound are also preferably used. Specific examples of the polyol compound having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Specific examples of the glycol ether compound include polyhydric alcohol alkyls such as 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. Ethers; Examples thereof include polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

Further, examples of the organic solvent include oxetane compounds such as 3-ethyl-3-hydroxymethyloxetane.

The content of the organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of the drying property and ejection reliability of the brilliant ink, 5% by mass or more with respect to the mass of the brilliant ink. It is preferably 60% by mass or less, and more preferably 10% by mass or more and 60% by mass or less.

<Water>
The content of water in the glitter ink is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of the drying property and ejection reliability of the glitter ink, 10% by mass or more and 90% by mass or less is used. It is preferably 20% by mass or more and 60% by mass or less, more preferably.

<Resin>
The glitter ink of the present embodiment does not have to contain a resin, but preferably contains a resin. The print layer formed on the recording medium using the brilliant ink containing the resin can stably maintain the structure in which the silver particles are spread without agglomeration. In addition, even if silver particles aggregate, the area where they aggregate can be reduced, so that the b * value, which is the chromaticity (chromaticity value) of the image, does not change significantly when the printed matter is stored at high temperature for a long period of time. Excellent. The resin is preferably a water-soluble resin that is soluble in water or a water-dispersible resin that can be dispersed in water, and may be used alone or in combination.

-Water-soluble resin-
The water-soluble resin is not particularly limited, and is not particularly limited, for example, proteins such as gelatin and casein, natural rubber such as Arabic rubber, glucoxide such as savonin, cellulose derivatives such as methyl cellulose, carboxymethyl cellulose and hydroxymethyl cellulose, and lignin sulfonic acid. Natural polymers such as salt and cellac, polyacrylic acid salt, polyacrylamide, styrene-acrylic acid copolymer salt, vinyl naphthalene-acrylic acid copolymer salt, styrene-maleic acid copolymer salt, vinyl naphthalene-maleic acid Examples include copolymer salts, sodium salts of β-naphthalene sulfonic acid horimarin condensates, ionic polymers such as polyphosphate, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polypropylene glycol, polyethylene oxide, polyvinyl methyl ether, polyethylene imine and the like. Be done. As the water-soluble resin, an appropriately synthesized resin may be used, or a commercially available product may be used. Further, these may be used alone or in combination of two or more kinds of water-soluble resins.

-Water-dispersible resin-
The water-dispersible resin is not particularly limited, and is, for example, a urethane resin, a polyester resin, an acrylic resin, a vinyl acetate resin, a styrene resin, a butadiene resin, a styrene-butadiene resin, and a vinyl chloride resin. , Acrylic styrene resin, acrylic silicone resin and the like. Resin particles made of these resins may be used. A brilliant ink can be obtained by mixing resin particles with a material such as silver particles or an organic solvent in the state of a resin emulsion in which water is used as a dispersion medium. As the water-dispersible resin, a synthetic resin may be used, or a commercially available product may be used. Further, these may be used alone or in combination of two or more kinds of water-dispersible resins.

The average particle size of the resin particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 nm or more and 30 nm or less from the viewpoint of obtaining good image quality and glossiness. The print layer formed on the recording medium using a brilliant ink containing resin particles having an average particle diameter of 10 nm or more and 30 nm or less can stably maintain a structure in which silver particles are spread without agglomeration. Further, even if the silver particles aggregate, the area where the silver particles aggregate can be reduced. Therefore, when the printed matter is stored at a high temperature for a long period of time, it is excellent in that the b * value, which is the chromaticity (chromaticity value) of the image, does not change significantly.

In this embodiment, the average particle size of the resin particles is measured as follows. First, 1 to 3 μl of a dispersion containing resin particles or a brilliant ink is collected, and a frozen body is prepared by a high-pressure freezing method. Next, after cutting the frozen body, a carbon replica membrane having a cross section is produced. Furthermore, the replica film is placed on a grid for a transmission type microscope (TEM), observed by TEM, the maximum diameter of the resin particles is measured in the TEM image in the range of 5 μm × 5 μm, and the arithmetic average value is the number average particle. The diameter.

-Resin content-
The content of the resin can be appropriately selected depending on the intended purpose, but is 0.01% by mass or more with respect to the mass of the brilliant ink from the viewpoint of good scratch resistance, imageability and metallic luster. It is preferably 0.05% by mass or more and 0.08% by mass or less, more preferably.

<Surfactant>
As the surfactant, any of a silicone-based surfactant, a fluorine-based surfactant, an amphoteric surfactant, a nonionic surfactant, and an anionic surfactant can be used.
The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Of these, those that do not decompose even at high pH are preferable. Examples of the silicone-based surfactant include side chain modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, single-ended modified polydimethylsiloxane, and side chain double-ended modified polydimethylsiloxane. Those having a polyoxyethylene group and a polyoxyethylene polyoxypropylene group as the modifying group are particularly preferable because they exhibit good properties as an aqueous surfactant. Further, as the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include compounds in which a polyalkylene oxide structure is introduced into the Si portion side chain of dimethylsiloxane.
Examples of the fluorine-based surfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. Polyoxyalkylene ether polymer compounds are particularly preferred because they have low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonic acid salt. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylic acid salt. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a poly having a perfluoroalkyl ether group in the side chain. Examples thereof include salts of oxyalkylene ether polymers. The counter ions of the salts in these fluorine-based surfactants include Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , and NH (CH ₂ CH ₂ OH). ₃ etc. can be mentioned.
Examples of the amphoteric tenside include laurylaminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Examples of the nonionic surfactant include polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, and polyoxyethylene sorbitan. Examples thereof include a fatty acid ester and an ethylene oxide adduct of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, lauryl salt, polyoxyethylene alkyl ether sulfate salt and the like.
These may be used alone or in combination of two or more.

The silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, side chain-modified polydimethylsiloxane, double-ended modified polydimethylsiloxane, one-ended modified polydimethylsiloxane, side. Examples thereof include polydimethylsiloxane modified at both ends of the chain, and a polyether-modified silicone-based surfactant having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group exhibits good properties as an aqueous surfactant, and is particularly effective. preferable.
As such a surfactant, an appropriately synthesized one may be used, or a commercially available product may be used. As commercially available products, for example, they can be obtained from Big Chemie Co., Ltd., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., Kyoeisha Chemical Co., Ltd. and the like.
The above-mentioned polyether-modified silicone-based surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a polyalkylene oxide structure represented by the general formula (S-1) is dimethylpoly. Examples thereof include those introduced into the Si part side chain of siloxane.

（但し、一般式（Ｓ－１）式中、ｍ、ｎ、ａ、及びｂは、それぞれ独立に、整数を表わし、Ｒは、アルキレン基を表し、Ｒ’は、アルキル基を表す。）
上記のポリエーテル変性シリコーン系界面活性剤としては、市販品を用いることができ、例えば、ＫＦ－６１８、ＫＦ－６４２、ＫＦ－６４３（信越化学工業株式会社）、ＥＭＡＬＥＸ－ＳＳ－５６０２、ＳＳ－１９０６ＥＸ（日本エマルジョン株式会社）、ＦＺ－２１０５、ＦＺ－２１１８、ＦＺ－２１５４、ＦＺ－２１６１、ＦＺ－２１６２、ＦＺ－２１６３、ＦＺ－２１６４（東レ・ダウコーニング・シリコーン株式会社）、ＢＹＫ－３３、ＢＹＫ－３８７（ビックケミー株式会社）、ＴＳＦ４４４０、ＴＳＦ４４５２、ＴＳＦ４４５３（東芝シリコン株式会社）などが挙げられる。

(However, in the general formula (S-1), m, n, a, and b each independently represent an integer, R represents an alkylene group, and R'represents an alkyl group.)
Commercially available products can be used as the above-mentioned polyether-modified silicone-based surfactant, for example, KF-618, KF-642, KF-643 (Shinetsu Chemical Industry Co., Ltd.), EMALEX-SS-5602, SS-. 1906EX (Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (Big Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.) and the like can be mentioned.

上記一般式（Ｆ－１）で表される化合物において、水溶性を付与するためにｍは０～１０の整数が好ましく、ｎは０～４０の整数が好ましい。

上記一般式（Ｆ－２）で表される化合物において、ＹはＨ、又はＣｍＦ_２ｍ＋１でｍは１～６の整数、又はＣＨ_２ＣＨ（ＯＨ）ＣＨ_２－ＣｍＦ_２ｍ＋１でｍは４～６の整数、又はＣｐＨ_２ｐ＋１でｐは１～１９の整数である。ｎは１～６の整数である。ａは４～１４の整数である。
上記のフッ素系界面活性剤としては市販品を使用してもよい。この市販品としては、例えば、サーフロンＳ－１１１、Ｓ－１１２、Ｓ－１１３、Ｓ－１２１、Ｓ－１３１、Ｓ－１３２、Ｓ－１４１、Ｓ－１４５（いずれも、旭硝子株式会社製）；フルラードＦＣ－９３、ＦＣ－９５、ＦＣ－９８、ＦＣ－１２９、ＦＣ－１３５、ＦＣ－１７０Ｃ、ＦＣ－４３０、ＦＣ－４３１（いずれも、住友スリーエム株式会社製）；メガファックＦ－４７０、Ｆ－１４０５、Ｆ－４７４（いずれも、大日本インキ化学工業株式会社製）；ゾニール（Ｚｏｎｙｌ）ＴＢＳ、ＦＳＰ、ＦＳＡ、ＦＳＮ－１００、ＦＳＮ、ＦＳＯ－１００、ＦＳＯ、ＦＳ－３００、ＵＲ、キャプストーンＦＳ－３０、ＦＳ－３１、ＦＳ－３１００、ＦＳ－３４、ＦＳ－３５（いずれも、Ｃｈｅｍｏｕｒｓ社製）；ＦＴ－１１０、ＦＴ－２５０、ＦＴ－２５１、ＦＴ－４００Ｓ、ＦＴ－１５０、ＦＴ－４００ＳＷ（いずれも、株式会社ネオス社製）、ポリフォックスＰＦ－１３６Ａ，ＰＦ－１５６Ａ、ＰＦ－１５１Ｎ、ＰＦ－１５４、ＰＦ－１５９（オムノバ社製）、ユニダインＤＳＮ－４０３Ｎ（ダイキン工業株式会社製）などが挙げられ、これらの中でも、Ｃｈｅｍｏｕｒｓ社製のＦＳ－３１００、ＦＳ－３４、ＦＳ－３００、株式会社ネオス製のＦＴ－１１０、ＦＴ－２５０、ＦＴ－２５１、ＦＴ－４００Ｓ、ＦＴ－１５０、ＦＴ－４００ＳＷ、オムノバ社製のポリフォックスＰＦ－１５１Ｎ及びダイキン工業株式会社製のユニダインＤＳＮ－４０３Ｎが特に好ましい。 As the fluorine-based surfactant, a compound having 2 to 16 carbon atoms substituted with fluorine is preferable, and a compound having 4 to 16 carbon atoms substituted with fluorine is more preferable.
Examples of the fluorine-based surfactant include a perfluoroalkyl phosphate ester compound, a perfluoroalkylethylene oxide adduct, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Among these, the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because it has less foaming property, and is particularly a fluorine-based compound represented by the general formula (F-1) and the general formula (F-2). Surfactants are preferred.

In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10 and n is preferably an integer of 0 to 40 in order to impart water solubility.

In the compound represented by the above general formula (F-2), Y is H or CmF _{2m + 1} and m is an integer of 1 to 6, or CH ₂ CH (OH) CH ₂ -CmF _{2m + 1} and m is 4 to 6. It is an integer, or CpH _{2p + 1} and p is an integer of 1 to 19. n is an integer of 1 to 6. a is an integer of 4 to 14.
Commercially available products may be used as the above-mentioned fluorine-based surfactant. Examples of this commercially available product include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Full Lard FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Co., Ltd.); Megafuck F-470, F -1405, F-474 (all manufactured by Dainippon Ink and Chemicals Co., Ltd.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by The Chemours Company); FT-110, FT-250, FT-251, FT-400S, FT-150, FT- 400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omniova), Unidyne DSN-403N (manufactured by Daikin Industries Co., Ltd.) Among these, FS-3100, FS-34, FS-300 manufactured by The Chemours Company, FT-110, FT-250, FT-251 manufactured by Neos Co., Ltd., FT-400S, FT-150, etc. FT-400SW, Polyfox PF-151N manufactured by Omniova Co., Ltd. and Unidyne DSN-403N manufactured by Daikin Industries Co., Ltd. are particularly preferable.

The content of the surfactant in the glitter ink is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.001% by mass or more and 5% by mass or less, preferably 0.05% by mass or more. More preferably, it is 5% by mass or less.

<Defoamer>
The defoaming agent is not particularly limited, and examples thereof include a silicone-based defoaming agent, a polyether-based defoaming agent, and a fatty acid ester-based defoaming agent. These may be used alone or in combination of two or more. Among these, a silicone-based defoaming agent is preferable because it has an excellent defoaming effect.

<Preservatives and fungicides>
The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one and the like.

<Rust inhibitor>
The rust preventive is not particularly limited, and examples thereof include acidic sulfites and sodium thiosulfate.

According to the embodiment of the present invention described later, benzotriazole and benzimidazole are particularly preferable because they can improve the rust preventive function and the stability of silver particles.

<pH adjuster>
The pH adjusting agent is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

<Physical characteristics>
The physical characteristics of the brilliant ink are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension, pH and the like are preferably in the following ranges.
The viscosity of the brilliant ink at 25 ° C. is preferably 1.0 mPa · s or more and 30.0 mPa · s or less, preferably 5.0 mPa, from the viewpoint of improving the print density and character quality and obtaining good ejection properties. -S or more and 30.0 mPa · s or less is more preferable, and 5 mPa · s or more and 25 mPa · s or less is further preferable. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. As the measurement conditions, it is possible to measure at 25 ° C. with a standard cone rotor (1 ° 34'× R24), a sample liquid volume of 1.2 mL, a rotation speed of 50 rpm, and 3 minutes.
The surface tension of the brilliant ink is preferably 35 mN / m or less, preferably 32 mN / m or less at 25 ° C. from the viewpoint that the brilliant ink is suitably leveled on the recording medium and the drying time of the brilliant ink is shortened. Is more preferable.
The pH of the brilliant ink is preferably 7 to 12, more preferably 8 to 11, from the viewpoint of preventing corrosion of the metal member that comes into contact with the liquid.

<< Achromatic and achromatic inks >>
The brilliant ink of the present embodiment is used together with a chromatic color ink or an achromatic color ink to impart brilliance to an image formed by a chromatic color ink or the like. The chromatic color ink contains a chromatic color material, and may contain other components such as an organic solvent, water, and a resin, if necessary. Further, the achromatic color ink contains an achromatic color material, and may contain other components such as an organic solvent, water, and a resin, if necessary. The chromatic color ink and the achromatic color ink will be described below, but the components other than the chromatic color material and the achromatic color material can be the same components as the brilliant ink, so the description thereof will be omitted. ..

<Colorful ink>
The chromatic color ink includes a chromatic color material and the like. Achromatic colors represent all colors except achromatic colors (colors in the series from white to gray to black). An image formed only with chromatic ink does not have brilliance.

-Coloring material of chromatic color-
The chromatic color material is not particularly limited, and pigments and dyes can be used. As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Further, a mixed crystal may be used as the pigment.
As the pigment, for example, a yellow pigment, a magenta pigment, a cyan pigment, a green pigment, an orange pigment and the like can be used.
Specific examples of the pigment include C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, 185, 213, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Calcium 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium Red), 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 213, 219, 224, 254, 264, C.I. I. Pigment Violet 1 (Rhodamine Lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15: 1, 15: 2, 15: 3, 15: 4 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment Greens 1, 4, 7, 8, 10, 17, 18, 36, etc.
Specific examples of the dye include, for example, C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142, C.I. I. Acid Red 52,80,82,249,254,289, C.I. I. Acid Blue 9,45,249, C.I. I. Direct Yellow 1,12,24,33,50,55,58,86,132,142,144,173, C.I. I. Direct Red 1,4,9,80,81,225,227, C.I. I. Direct Blue 1,2,15,71,86,87,98,165,199,202, C.I. I. Reactive red 14, 32, 55, 79, 249 and the like can be mentioned.

The content of the chromatic color material in the chromatic color ink is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass, from the viewpoint of improving the image density, good fixing property and ejection stability. % Or more and 10% by mass or less.

<Achromatic ink>
The achromatic ink includes an achromatic color material and the like. Achromatic color represents a series of colors from white to gray to black. An image formed only with achromatic ink does not have brilliance.

-Achromatic color material-
The achromatic color material is not particularly limited, and pigments and dyes can be used. As the pigment, an inorganic pigment or an organic pigment can be used. These may be used alone or in combination of two or more. Further, a mixed crystal may be used as the pigment.
As the pigment, for example, a black pigment, a white pigment, or the like can be used.
Specific examples of the pigment include carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black and channel black, copper, iron (CI pigment black 11), titanium oxide and the like. Metals of the above, organic pigments such as aniline black (CI pigment black 1) can be mentioned.
Specific examples of the dye include, for example, C.I. I. Acid Black 1,2,24,94, C.I. I. Hood Black 1, 2, C.I. I. Direct Black 19,38,51,71,154,168,171,195, C.I. I. Reactive Black 3, 4, 35 can be mentioned.

The content of the achromatic color material in the achromatic ink is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass, from the viewpoint of improving the image density, good fixing property and ejection stability. % Or more and 10% by mass or less.

<< Ink set >>
The brilliant ink of the present embodiment is preferably combined with a chromatic ink or an achromatic ink to form an ink set. By using this ink set, it is possible to impart brilliance to an image formed by chromatic ink or achromatic ink.
Further, the achromatic color and chromatic color ink described above are solvent-based inks containing water and the like similar to the brilliant ink, and the method of forming the achromatic color layer and the chromatic color layer with the (light) curable ink described later is also a brilliant layer. Can be toned

<< Recording medium >>
The recording medium to which the glitter ink of the present embodiment is applied is not particularly limited, and examples thereof include glossy paper having a receiving layer on the surface, a non-permeable base material, and the like. A receiving layer (porous or the like) may or may not be formed in advance on the surface of the recording medium. Further, the recording medium is not limited to that generally used as a recording medium, and wallpaper, flooring, building materials such as tiles, cloth for clothing such as T-shirts, textiles, leather and the like can be appropriately used. .. Further, ceramics, glass, metal, or the like can be used by adjusting the configuration of the path for transporting the recording medium.

The non-permeable base material is a base material having a surface having a low water permeability and absorbability, and includes a material that does not open to the outside even if there are many cavities inside, and more quantitatively, A substrate having a water absorption of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method. As the impermeable substrate, for example, a plastic film such as a vinyl chloride resin film, a polyethylene terephthalate (PET) film, polypropylene, polyethylene, or a polycarbonate film can be preferably used.

As a recording medium having a receiving layer having a receiving layer (porous) in advance, a commercially available product can be used. Examples of commercially available products include IJ film RM-1GP01 manufactured by Ricoh Co., Ltd. (average pore diameter of porous medium: 230 nm); NB-WF-3GF100 manufactured by Mitsubishi Paper Co., Ltd. (average pore diameter of porous medium: 210 nm), NB. -RC-3GR120 (porous average pore size: 250 nm); PT-201A420 (porous average pore size: 270 nm), SD-101A450 (porous average pore size: 250 nm), GL-101A450 (porous) manufactured by Canon Corporation. Quality average pore diameter: 240 nm), GP501A450 (porous average pore diameter: 250 nm), SP-101A450 (porous average pore diameter: 210 nm), PT-101A420 (porous average pore diameter: 240 nm), PR101 (porous average pore diameter: 240 nm) Average pore diameter: 270 nm); EJK-QTNA450 (porous average pore diameter: 200 nm), EJK-EPNA450 (porous average pore diameter: 210 nm), EJK-CPNA450 (porous average pore diameter: 220 nm), manufactured by Elecom Co., Ltd., EJK-RCA450 (Porous Medium Pore Diameter: 240 nm), EJK-CGNA450 (Porous Medium Pore Diameter: 190 nm), EJK-GANA450 (Porous Medium Pore Diameter: 180 nm), EJK-NANA450 (Porous Medium Pore Diameter: 170 nm) ), EJK-EGNA450 (Porous Medium Pore Diameter: 200 nm); WPA455VA (Porous Medium Pore Diameter: 200 nm), WPA450PRM (Porous Medium Pore Diameter: 210 nm), G3A450A (Porous Medium Pore Diameter: 210 nm), manufactured by Fujifilm Co., Ltd. : 220 nm), G3A450A (Porous Medium Pore Diameter: 210 nm), WPA420HIC (Porous Medium Pore Diameter: 280 nm); KA420SKKR (Porous Medium Pore Diameter: 240 nm), KA450PSKR (Porous Medium Pore Diameter: 240 nm) : 230 nm), KA450SLU (porous average pore size: 210 nm); BP71GAA4 manufactured by Brother Industries, Ltd. (porous average pore diameter: 220 nm) and the like.

<< Recording device, recording method >>
The brilliant ink of the present embodiment can be suitably used for various recording devices by an inkjet recording method, for example, a printer, a facsimile device, a copying device, a printer / fax / copier multifunction device, a three-dimensional modeling device, and the like.
In the present invention, the recording device and the recording method are devices capable of ejecting ink, various processing liquids, and the like to a recording medium, and a method for recording using the device. The recording medium means a medium to which ink and various treatment liquids can adhere even temporarily.
This recording device can include not only a head portion for ejecting ink, but also means related to feeding, transporting, and discharging paper of a recording medium, a pretreatment device, a device called a posttreatment device, and the like. ..
The recording device and the recording method may have a heating means used in the heating step and a drying means used in the drying step. The heating means and the drying means include, for example, means for heating and drying the printed surface and the back surface of the recording medium. The heating means and the drying means are not particularly limited, but for example, a hot air heater and an infrared heater can be used. Heating and drying can be performed before printing, during printing, after printing, and the like.
Further, the recording device and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, those that form patterns such as geometric patterns and those that form three-dimensional images are also included.
Further, the recording device includes both a serial type device that moves the discharge head and a line type device that does not move the discharge head, unless otherwise specified.
Further, as this recording device, it is possible to use not only a desktop type but also a wide recording device capable of printing on an A0 size recording medium, or, for example, continuous paper wound in a roll shape as a recording medium. A continuous book printer is also included.
An example of the recording device will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective explanatory view of the device. FIG. 2 is a perspective explanatory view of the main tank. The image forming apparatus 400 as an example of the recording apparatus is a serial type image forming apparatus. A mechanism portion 420 is provided in the exterior 401 of the image forming apparatus 400. Each ink container 411 of the main tank 410 (410s, 410c, 410m, 410y) for each color of silver (S), cyan (C), magenta (M), and yellow (Y) is packaged with, for example, an aluminum laminated film. It is formed of members. The ink container 411 is housed in, for example, a plastic container case 414. As a result, the main tank 410 is used as an ink cartridge for each color.
On the other hand, a cartridge holder 404 is provided behind the opening when the cover 401c of the main body of the apparatus is opened. A main tank 410 is detachably attached to the cartridge holder 404. As a result, each ink ejection port 413 of the main tank 410 and the ejection head 434 for each color communicate with each other via the supply tube 436 for each color, and ink can be ejected from the ejection head 434 to the recording medium.

The silver (S) ink described above is an example of the glitter ink of the present embodiment. Further, the color inks of each color of cyan (C), magenta (M), and yellow (Y) are examples of chromatic color inks. In addition to the above four types of ink, inks such as black (K) and white (W), which are examples of achromatic inks, may be additionally used. If additional ink is used, a liquid reservoir and liquid ejection head with the additional ink are added to the recording device. The recording device executes a step of applying silver ink (an example of the first ink applying step) from a silver ink ejection head (an example of the first ink applying means), and then applies the silver ink to the applied silver ink. , The step of applying cyan ink or the like (an example of the second ink applying step) from the ejection head of cyan ink or the like (an example of the second ink applying means) is executed so that at least a part of the ink is overlapped. This makes it possible to impart brilliance such as metallic luster to a chromatic or achromatic image.

This recording device can include not only a portion for ejecting ink but also a device called a pretreatment device, a posttreatment device, and the like.
As one aspect of the pretreatment device and the posttreatment device, it has a pretreatment liquid and a posttreatment liquid as in the case of inks such as silver (S), cyan (C), magenta (M), and yellow (Y). There is an embodiment in which a liquid accommodating portion and a liquid discharge head are added, and a pretreatment liquid or a posttreatment liquid is discharged by an inkjet recording method.
As another aspect of the pretreatment device and the posttreatment device, there is a mode in which a pretreatment device and a posttreatment device by, for example, a blade coating method, a roll coating method, and a spray coating method are provided other than the inkjet recording method.

The method of using the ink is not limited to the inkjet recording method, and can be widely used. In addition to the inkjet recording method, examples thereof include a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and a spray coating method.

<< Printed matter >>
The printed matter formed by using the brilliant ink of the present embodiment comprises the above-mentioned recording medium and a printed layer formed by the brilliant ink and the chromatic color ink or the achromatic color ink applied on the recording medium. Have.

<Print layer>
The print layer has a brilliant print layer formed by a brilliant ink on a curable ink layer, and further a chromatic color print layer formed by the chromatic ink or an achromatic print layer formed by the chromatic ink. There may be. The positional relationship between the brilliant print layer and the above-mentioned chromatic color print layer or achromatic color print layer is not particularly limited.

-Glittering print layer-
The brilliant printing layer is a layer containing silver particles, an appropriate amount of a surfactant, and if necessary, a resin or the like.
The average particle size of the silver particles is 100 nm or less, preferably 40 nm or less. Further, the average particle diameter of the spherical silver particles is preferably 5 nm or more. When the average particle diameter of the spherical silver particles is 100 nm or less, the glossiness and image quality of the image can be improved.

When the brilliant print layer contains a resin, the glossiness and image quality of the print layer are improved, and the scratch resistance is also improved.
The content of the resin is preferably 0.01% by mass or more and 2.0% by mass or less, and more preferably 0.01% by mass or more and 1.6% by mass or less with respect to the mass of the brilliant printing layer. When the content is within the above range, the glossiness and image quality of the print layer are improved, and the scratch resistance is also improved.
The resin contained in the print layer is preferably resin particles having an average particle diameter of 10 nm or more and 30 nm or less. The average particle size of the resin particles contained in the brilliant printed layer is obtained by measuring the maximum diameter of the resin particles in the TEM image in the range of 10 μm × 10 μm and calculating the average.

The layer thickness of the brilliant print layer is preferably 50 nm or more and 300 nm or less, more preferably 50 nm or more and 250 nm or less, further preferably 50 nm or more and 200 nm or less, and particularly preferably 50 nm or more and 180 nm or less. preferable. When the layer thickness of the brilliant print layer is within this range, the structural color tone derived from the absorption of plasmons of the silver particles is lowered, and the brilliant print layer having excellent metallic luster and image quality can be formed. Further, if the layer thickness of the printing layer is within this range, the vehicle of the brilliant ink can be immediately absorbed when the recording medium has a porous structure, and the metallic luster and the mapping can be obtained. It is possible to form a brilliant print layer having excellent properties. Further, the layer thickness of the brilliant print layer needs to be at least one silver particle. By arranging the silver particles on the recording medium in the horizontal direction for one layer or more, the interaction between the silver particles is increased, and a metal-like print layer having excellent image quality can be formed. The brilliant print layer for measuring the layer thickness is a layer after the brilliant ink applied to the recording medium is sufficiently dried. The layer thickness of the brilliant print layer is an average value of the layer thickness measured at 10 arbitrary points of the print layer. Examples of the method for measuring the layer thickness of the brilliant printed layer include a method of cutting a printed matter and observing the cut surface with a microscope such as an optical microscope, a laser microscope, an SEM, and a TEM.

The b * value of the brilliant print layer is based on the color difference display method by the L * a * b * color system standardized by CIE (Commission International del'Eclairage). The b * value is preferably −7 to 0 in order for the glittering print layer to have high image quality and be silvery. As for the b * value, the bluish color becomes stronger toward the negative side, and conversely, the yellowish color becomes stronger toward the positive side. When the yellow color becomes stronger, the brilliant print layer approaches gold color, and when the b * value exceeds 0, the gold color is strongly expressed and the color tone becomes hard to say silver. On the contrary, when the b * value is less than -7, the bluish color becomes strong and the color tone becomes dark and different from the silver color tone. As for the method of measuring the b * value, it can be easily measured with a spectrocolorimeter.

The surface roughness Ra of the brilliant printed layer is preferably 20 nm or less. This makes it possible to obtain a print layer having excellent glossiness and image quality. The method for reducing the surface roughness Ra of the glittering printed layer to 20 nm or less is not particularly limited, but for example, it is preferable to reduce the average particle size of the spherical silver particles, and specifically, the average of the spherical silver particles. It is more preferable that the particle size is 40 nm or less.

Examples of the curable (clear) ink composition of the present invention include a heat-curable (clear) ink composition and an active energy ray-curable clear ink composition, but the active energy ray-curable clear ink composition is more suitable. Suitable.

<Polymerizable compound>
The curable (clear) ink composition of the present invention contains a polymerizable compound. The polymerizable compound indispensably contains a monofunctional polymerizable compound, and the content of the monofunctional polymerizable compound is 50% by mass or more and 90% by mass or less with respect to the total amount of the curable (clear) ink composition. Is preferable, and 70% by mass or more and 90% by mass or less is more preferable.

Examples of the monofunctional polymerizable compound include a monofunctional polymerizable compound having a static surface tension of 33 mN / m or less at 25 ° C. and a monofunctional polymerizable compound having a static surface tension of more than 33 mN / m at 25 ° C. ..

The monofunctional polymerizable compound having a static surface tension of 33 mN / m or less at -25 ° C is not particularly limited as a monofunctional polymerizable compound having a static surface tension of 33 mN / m or less at -25 ° C, depending on the intended purpose. It can be appropriately selected, for example, isobornyl (meth) acrylate (static surface tension at 25 ° C.: 33 mN / m), lauryl (meth) acrylate (static surface tension at 25 ° C.: 29 mN / m), isodecyl (meth). ) Acrylic (static surface tension at 25 ° C.: 28 mN / m), isooctyl (meth) acrylate (static surface tension at 25 ° C.: 28 mN / m), n-octyl (meth) acrylate (static surface tension at 25 ° C.) : 28 mN / m), isobutyl (meth) acrylate (static surface tension at 25 ° C: 25 mN / m), isononyl (meth) acrylate (static surface tension at 25 ° C: 28 mN / m), octyl / decyl (meth) Examples thereof include acrylate (static surface tension at 25 ° C.: 29 mN / m). These may be used alone or in combination of two or more. Among these, isobornyl (meth) acrylate is preferable from the viewpoint of increasing the hardness of the coating film.
The content of the monofunctional polymerizable compound having a static surface tension of 33 mN / m or less at 25 ° C. is 10% by mass or more and 30% by mass or less and 15% by mass with respect to the total amount of the curable (clear) ink composition. % Or more and 25% by mass or less are preferable. When the content is 10% by mass or more and 30% by mass or less, there are advantages that the ejection stability and the coating film hardness are excellent.
The static surface tension can be measured by, for example, a static surface tension measuring device.
Further, the above-mentioned photocurable ink which may be used as another kind of curable ink or curable chromatic color ink by adding the coloring materials, monomers and polymer materials described in JP-A-2020-117603 and JP-A-2019-163377 is heated. In the present invention, the curing of the present invention can also be obtained by applying heat because the curing proceeds to a certain extent.

<Polymerizable compound>
The active energy ray-curable composition of the present invention contains a polymerizable compound (monomer) as a curable component. Examples of the polymerizable compound include, but are not limited to, the monofunctional monomers described below. Further, these polymerizable compounds may be used in combination of two or more, if necessary.
Phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2 -Ethoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxyethylacrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, 2-hydroxyethyl acrylate, ethyldiglycol acrylate, cyclic trimetylolpropaneformal monoacrylate, imide acrylate, isoamyl acrylate. , Ethoxylated succinic acid acrylate, trifluoroethyl acrylate, ω-carboxypolycaprolactone monoacrylate, benzyl acrylate, methylphenoxyethyl acrylate, cyclohexyl acrylate, 4-t-butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, tribromophenyl acrylate. , Ethoxylated tribromophenyl acrylate, 2-phenoxyethyl acrylate, acryloylmorpholine, phenoxydiethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, 2- (2-ethoxyethoxy) ethyl Acrylate, stearyl acrylate, diethylene glycol monobutyl ether acrylate, lauryl acrylate, isodecyl acrylate, 3,3,5-trimethylcyclohexanol acrylate, isooctyl acrylate, octyl / decyl acrylate, tridecyl acrylate, caprolactone acrylate, ethoxylated (4) nonylphenol Examples thereof include acrylate, methoxypolyethylene glycol (350) monoacrylate, methoxypolyethylene glycol (550) monoacrylate, N-vinylformamide, N-vinylcaprolactam, vinylpyrrolidone and the like.

<Polyfunctional (meth) acrylate compound>
In the present invention, in addition to the above monofunctional monomer, a polyfunctional monomer having two or more ethylenically unsaturated double bonds can also be used. Examples include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, tetraethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol triacrylate, polypropylene. Glycol diacrylate, neopentyl glycol diacrylate, bispentaerythritol hexaacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, ethoxylated-1,6-hexanediol diacrylate, 1,4-butanediol diacrylate, 1,9-Nonandiol diacrylate, 2-n-butyl-2-ethyl-1,3-propanediol diacrylate, neopentyl glycol diacrylate hydroxypivalate, trimethylolpropane triacrylate hydroxypivalate, 1,3- Butylene glycol di (meth) acrylate, ethoxylated phosphate triacrylate, ethoxylated tripropylene glycol diacrylate, neopentyl glycol-modified trimethylolpropane diacrylate, stearic acid-modified pentaerythritol diacrylate, tetramethylolmethanetriacrylate, tetramethylolmethane Tetraacrylate, tetramethylolpropanetriacrylate, caprolactone-modified trimethylolpropanetriacrylate, propoxylate glyceryltriacrylate, dimethylolpropanetetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, Dipentaerythritol hydroxypentaacrylate, neopentyl glycol oligoacrylate, 1,4-butanediol oligoacrylate, 1,6-hexanediol oligoacrylate, trimethylolpropane oligoacrylate, pentaerythritol oligoacrylate, ethoxylated neopentylglycoldi (meth) ) Acrylic, propoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, ethoxylated trimethylolpropane triacrylate, propoxylated tri Examples include, but are not limited to, trimethylolpropane triacrylate.
If necessary, two or more kinds of these polyfunctional monomers may be used in combination.

The blending amount of the polyfunctional monomer, together with the polyfunctional oligomer described later, is, for example, 0.01 to 20% by mass, more preferably 5.0 to 15.0% by mass, based on the entire active energy ray-curable composition. be. Within this range, it is possible to obtain a cured product having both adhesion and a viscosity suitable for inkjet.

<Oligomer>
In the present invention, in addition to the monofunctional monomer, an oligomer having an ethylenically unsaturated double bond can be used. Examples thereof include aromatic urethane oligomers, aliphatic urethane oligomers, epoxy acrylate ligomers, polyester acrylate ligomers, and other special oligomers.

<Curing means>
Examples of the curing means for curing the curable clear ink composition of the present invention include heat curing or curing with active energy rays, and among these, curing with active energy rays is preferable.
The active energy rays used to cure the curable clear ink composition include ultraviolet rays, as well as polymerization reactions of polymerizable components in the composition such as electron beams, α rays, β rays, γ rays, and X-rays. It is not particularly limited as long as it can provide the energy necessary for advancing. In particular, when a high-energy light source is used, the polymerization reaction can proceed without using a polymerization initiator. Further, in the case of ultraviolet irradiation, mercury-free is strongly desired from the viewpoint of environmental protection, and replacement with a GaN-based semiconductor ultraviolet light emitting device is very useful industrially and environmentally. Furthermore, an ultraviolet light emitting diode (UV-LED) and an ultraviolet laser diode (UV-L)
D) has a small size, a long life, high efficiency, and low cost, and is preferable as an ultraviolet light source. It is more preferable to use a light emitting diode having a wavelength of 350 nm or more and 450 nm or less (particularly, a wavelength of 350 nm or more and 400 nm or less).

Further, in the present invention, after forming a curable ink layer, light or heat energy that does not reach complete curing is given as pre-curing before forming a brilliant ink layer on the curable ink layer, and the ink layer is brilliant in a semi-cured state. It is also possible to form a sex ink layer.

-Achromatic print layer and achromatic print layer-
The chromatic color printing layer is a layer containing a chromatic color material, and the achromatic color printing layer is a layer containing an achromatic color material. Further, the chromatic color printing layer or the achromatic color printing layer is preferably located on the brilliant printing layer, and more preferably constitutes the surface of the printing layer. The curable ink described above may or may not be a chromatic or achromatic printing layer.

The layer thickness of the chromatic color printing layer or the achromatic color printing layer is preferably 1 nm or more and 300 nm or less, and more preferably 2 nm or more and 250 nm or less. When the layer thickness of the chromatic color printing layer or the chromatic color printing layer is within this range, the brilliance exhibited by the brilliant printing layer is due to the chromatic color printing layer or the chromatic color printing layer formed on the brilliant printing layer. It can be suppressed from being concealed. As a result, it is possible to obtain a print layer which is a brilliant colored image having excellent glossiness and image quality and excellent color tone. The chromatic color printing layer or the achromatic color printing layer for which the layer thickness is measured is a layer after the chromatic color ink or the achromatic color ink applied to the recording medium is sufficiently dried. The layer thickness of the chromatic color print layer or the achromatic color print layer is an average value of the layer thickness measured at 10 arbitrary points of the print layer. Examples of the method for measuring the layer thickness of the chromatic color printing layer and the chromatic color printing layer include a method of cutting a printed matter and observing the cut surface with a microscope such as an optical microscope, a laser microscope, SEM, or TEM.

<< Use >>
The use of the brilliant ink of the present embodiment is not particularly limited and can be appropriately selected depending on the intended purpose, and can be applied to, for example, printed matter, paint, coating material, base material and the like. Further, it can be used not only for forming two-dimensional characters and images, but also as a three-dimensional modeling material for forming a three-dimensional stereoscopic image (three-dimensional model).
As a three-dimensional modeling apparatus for modeling a three-dimensional object, a known one can be used, and is not particularly limited, but for example, an apparatus provided with a means for accommodating bright ink, a means for supplying ink, a means for ejecting, a means for drying, and the like. Can be used. The three-dimensional model includes a three-dimensional model obtained by overcoating with ink. Further, a molded product obtained by processing a structure in which ink is applied on a base material such as a recording medium is also included. The molded product is, for example, a printed matter or structure formed in a sheet shape or a film shape, which has been subjected to molding processing such as heat stretching or punching. For example, an automobile, an OA device, an electric / electronic product. It is suitably used for molding after decorating the surface of equipment, meters of cameras, panels of operation parts, and the like.

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

<Preparation example of resin dispersion liquid containing resin particles>
In a nitrogen-substituted container equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer, polyester polyol (trade name: PTMG1000, manufactured by Mitsubishi Chemical Corporation, average molecular weight: 1,000) 200.4 g, 2,2 -The reaction was carried out using 15.7 g of dimethylol propionic acid, 48.0 g of isophorone diisocyanate, and 77.1 g of methyl ethyl ketone as an organic solvent, and 0.06 g of dibutyltin dilaurate (DMTDL, manufactured by Tokyo Chemical Corporation) as a catalyst. After the reaction was continued for 4 hours, 30.7 g of methyl ethyl ketone was supplied as a diluting solvent, and the reaction was further continued. After the reaction was carried out for a total of 6 hours, 1.4 g of methanol was added to terminate the reaction, whereby an organic solvent solution of urethane resin was obtained. The carboxyl group of the urethane resin was neutralized by adding 13.4 g of a 48 mass% potassium hydroxide aqueous solution to the organic solvent solution of the urethane resin, then 715.3 g of water was added, and after sufficient stirring, aging and By removing the solvent, a resin dispersion liquid 1 containing polyester urethane resin particles having a solid content concentration of 30% by mass was obtained.

<Preparation example of silver particle dispersion liquid containing silver particles>
(Silver particle dispersion 1)
66.8 g of silver nitrate, dispersant polymer having a carboxyl group (trade name: Disperbic 190, manufactured by Big Chemie Japan Co., Ltd., solvent: water, 40% by mass of non-volatile component, acid value: 10 mgKOH / g, amine value: 0 mgKOH / g ) 7.2 g and 2.2 g of cholic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were added to 100 g of ion-exchanged water and stirred vigorously to obtain a suspension. To the obtained suspension, gradually add 100 g of dimethylaminoethanol (manufactured by Wako Pure Chemical Industries, Ltd.) so that the water temperature does not exceed 50 ° C, and then heat in a water bath with a water temperature of 50 ° C for 3 hours. The mixture was stirred to obtain a reaction solution. The obtained reaction solution was filtered through a glass filter (trade name: GC-90, manufactured by ADVANTEC, average pore size: 0.8 μm) to obtain a silver particle dispersion 1 containing 20% by mass of silver particles.
A few μl of the obtained silver particle dispersion 1 was collected, a frozen body was prepared by a high-pressure freezing method, the frozen body was cut, and then a carbon replica film having a cross section was prepared. The replica film was placed on the TEM grid, observed with a transmission electron microscope (TEM) (manufactured by JEOL Ltd.), and almost all of the TEM images in the range of 5 μm × 5 μm had a spherical shape. When the maximum diameter of the silver particles was measured and the arithmetic average value was obtained, the number average particle diameter was 25 nm.

(Silver particle dispersion liquid 2 to 6)
In the preparation of the silver particle dispersion liquid 1, the average particle size of the silver particles was changed as shown in Table 2 below by adjusting the rate of addition of dimethylaminoethanol and the water temperature, but the same procedure as in Preparation Example 1 was carried out. Silver particle dispersions 2 to 6 containing 15% by mass of silver particles were obtained. With respect to the obtained silver particle dispersions 2 to 6, the shape of the silver particles was observed and the average particle size was determined in the same manner as in the silver particle dispersion 1. The results are shown in Table 1.

(Silver particle dispersion 7)
In the preparation of the silver particle dispersion 1, a silver particle dispersion 7 containing 20% by mass of silver particles was obtained in the same manner as in Preparation Example 1 except that cholic acid was replaced with propionic acid (manufactured by Wako Pure Chemical Industries, Ltd.). rice field. With respect to the obtained silver particle dispersion liquid 7, the shape of the silver particles was observed and the average particle diameter was determined in the same manner as in the silver particle dispersion liquid 1.
The results are shown in Table 1.

(Silver particle dispersion liquid 8)
50 g of silver nitrate was dissolved in 1 L of distilled water to obtain the first solution. On the other hand, 22.2 g of oxalic acid was dissolved in 1 L of distilled water to obtain a second solution. The first solution and the second solution were mixed to obtain a mixed solution containing silver oxalate. Impurities were removed from this mixture. 3 g of polyethylene glycol (dispersant) was added to 1 L of the mixed solution, and the mixture was stirred for 50 minutes while adding ultrasonic waves. As a result, silver oxalate was dispersed. This mixed solution was put into an autoclave. This mixed solution was pressurized at a pressure of 0.5 MPa. The mixture was heated to 155 ° C. with stirring at a rate of 900 rpm. Stirring was carried out at this temperature for 30 minutes to obtain a liquid containing fine particles containing silver as a main component. The average value of the arithmetic mean roughness Ra of these fine particles was 2.0 nm.
The liquid containing the fine particles containing silver as a main component was centrifuged to remove excess polyethylene glycol. Further, this precipitate was put into ethylene glycol monoethyl ether acetate (ECA) and stirred. The precipitate was removed and excess ethylene glycol monoethyl ether acetate was removed with a centrifuge. The precipitate was heat-dried for a predetermined time to obtain a silver particle dispersion liquid 8 which is a fine silver particle-containing composition. The composition contains 90% by weight of silver particles and 10% by weight of other substances (mainly ethylene glycol monoethyl ether acetate).
When the particle size of the silver particles obtained was confirmed with a transmission electron microscope (manufactured by JEOL Ltd.) in the same manner as the silver particle dispersion 1, the average particle size was 105 nm. The fine particles are flaky. The average thickness as observed by transmission electron microscopy was 30 nm.

(Silver particle dispersion 9)
In the preparation of the silver particle dispersion liquid 8, the silver particle dispersion was carried out in the same manner as in Preparation Example 8 of the silver particle dispersion liquid, except that the mixture charged into the autoclave was heated to 170 ° C. while being stirred at 1,200 rpm. Liquid 9 was obtained.
When the silver particles of the obtained silver particle dispersion 9 were observed with a transmission electron microscope (manufactured by JEOL Ltd.), the fine particles were flaky, the average particle diameter was 95 nm, and the average thickness was 28 nm. there were.

<Ink preparation example>
(Ink 1)
Silver particle dispersion 1 is 25.0% by mass, dimethylaminoethanol (manufactured by Wako Pure Chemical Industries, Ltd.) is 0.1% by mass, and 1,2-propanediol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) is 25.0% by mass. %, 3-methoxy-3-methyl-1-butanol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 10.0% by mass, 3-ethyl-3-hydroxymethyloxetane (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 5.0% by mass %, 0.12% by mass of resin dispersion 1, 0.5% by mass of LS-106 (polyoxyalkylene alkyl ether manufactured by Kao) as a surfactant, and Proxel LV (manufactured by Abyssia) as an antiseptic and antifungal agent. Add 0.1% by mass, 1,2,3-benzotriazole (manufactured by Tokyo Kasei Kogyo Co., Ltd.) to 0.04% by mass, and add the remaining amount of ion-exchanged water so that the total becomes 100% by mass and mix. After stirring, the mixture was filtered through a polypropylene filter having an average pore size of 0.2 μm (trade name: syringe filter, manufactured by Sartorius) to obtain [Ink 1].

(Ink 2 to 15)
[Ink 2] to [Ink 15] were obtained in the same manner as in Preparation Example 1 except that the amounts of the constituent components used in the preparation of Ink 1 were changed as shown in Table 2-1 and Table 2-2. .. The unit of the numerical value indicating the content of each component in Tables 2-1 and 2-2 is "mass%".

For the obtained inks 1 to 15, the average particle size of the silver particles was confirmed using a transmission electron microscope (manufactured by JEOL Ltd.) in the same manner as in the silver particle dispersion liquid 1. As a result, it was confirmed that the average particle size of the spherical silver particles in the inks 1 to 15 was the same as the average particle size of the silver particles in each silver particle dispersion.
The formulations of each ink are shown in Tables 2-1 to 2-2.

<Preparation example of photocurable ink>
(Photo-curing ink 1)
Each of the materials shown in Table 3 was added with stirring in sequence, and then stirred for 2 hours to prepare a photocurable ink 1. The photocurable ink 1 is a chromatic ink containing a magenta pigment.
The unit of the numerical value representing the content of each component in Table 3 is "mass%".

(Photo-curing ink 2-4)
Each of the materials shown in Table 3 was added with stirring in sequence, and then stirred for 2 hours to prepare photocurable inks 2 to 4. The photocurable inks 2 to 4 are achromatic (clear) inks.

<Image formation>
In the examples, images were formed by the methods shown in the following steps 1 to 5.
Step 1: Forming a photocurable ink layer on a recording medium Step 2: Early stage The photocurable ink layer is irradiated with UV light or heat is applied to form a curable layer. This step is positioned as a pre-curing step, and may or may not be present, and the photo-curing layer may or may not be completely cured. Step 3: A glittering ink layer is placed on the photo-curing ink layer. Step 4: Apply UV light from the glittering ink layer forming side or the recording selling body side (back surface side) to further promote the curing of the photocurable ink. When a transparent PET substrate is used as the recording medium, curing can be effectively promoted even by irradiation with light from the back surface. Step 5: Further, the recording medium is heated to promote drying for the purpose of completely volatilizing the residual volatile matter. However, this step 5 is not always essential.
Specifically, each of the above steps was performed as follows.

Using the recording media shown in Table 4, in a printing machine using a GEN5 head manufactured by Ricoh Co., Ltd., the ink ejection frequency is 28 kHz, the resolution is 600 dpi x 600 dpi, and the average thickness of the photocurable ink layer is 20 μm or more. A solid image was printed, and FJ800 (wavelength 395 nm) manufactured by Phoseon was used as a pre-curing step to irradiate UV with an illuminance of 1 W / cm ² so that the integrated light amount shown in Table 4 was obtained. The pre-curing conditions by heat are shown in Table 4. Regarding heat application, a method in which the recording medium is brought into close contact with a hot plate or the like may be used, or a method in which the recording medium is put into an oven to apply heat may be used. In this embodiment, the recording medium is put into an oven to apply heat. ..

Next, each of the obtained glitter inks 1 to 15 was filled in an inkjet printer (IPSiO GXe5500, manufactured by Ricoh Co., Ltd.), and in all of the examples, the above-mentioned photocuring was performed on a hot plate at a recording medium temperature of 55 ° C. A brilliant solid image was formed on a recording medium provided with a mold ink. After that, in order to further promote the curing degree of the UV-curing ink layer, FJ800 (wavelength 395 nm) manufactured by Phoseon was used again as the main curing step, and the UV was measured to have the integrated light amount shown in Table 4 at an illuminance of 1 W / cm ² . Was UV-irradiated. Further, when the step of heating and drying the recording medium (for the purpose of evaporating the residual volatile matter as necessary) is to be added, the temperature of the recording medium is adjusted to the temperature shown in Table 4 with a hot plate and the time shown in Table 4 is added. It was dried.
Then, using the formed solid image, the glossiness and the scratch resistance were evaluated according to the following evaluation method. The results are shown in Table 4.

[Evaluation of glossiness]
The 20 ° glossiness of the solid image was measured using a glossiness meter (Microtrigloss manufactured by BYK Gardener) and evaluated according to the following criteria. The evaluation is preferably A or higher.
S: 20 ° glossiness is 500 or more A: 20 ° glossiness is 400 or more and less than 500 B: 20 ° glossiness is 300 or more and less than 400 C: 20 ° glossiness is 100 or more and less than 300 D: 20 ° gloss Degree less than 100

[Evaluation of scratch resistance]
Set the dried printed matter on the Gakushin type friction fastness tester AB-301 (manufactured by Tester Sangyo Co., Ltd.), and use a friction element (load; 300 g) with a white cotton cloth (JIS L 0803 compliant) attached to the contact part. After rubbing 10 times, the degree of deterioration was visually observed and evaluated according to the following criteria. The desired level is A or higher.
[Evaluation criteria]
A: The number of scratches is less than 5, and the base is not visible.
B: The number of scratches is 5 or more and less than 10, and the base is not visible.
C: There are 10 or more scratches and the base is exposed.

Since PET is transparent, it also has brilliance from the opposite side. The scratch resistance of the surface opposite to the ink forming surface was A rank.

The present invention relates to the image forming method described in the following (1), and has the following embodiments (2) to (5).
(1) A step of applying a photocurable ink on a recording medium to form a photocurable ink layer, and
A step of applying a brilliant ink containing a brilliant pigment having a number average particle diameter of 100 nm or less on the photocurable ink layer to form a brilliant ink layer.
A step of curing the photocurable ink layer by irradiating the photocurable ink layer with light or applying heat to form a cured layer of the photocurable ink.
Image forming method having.
(2) A step of applying a photocurable ink on a recording medium to form a photocurable ink layer, and
A step of pre-curing the photo-curable ink layer by irradiating the photo-curable ink layer with light or applying heat to form a pre-cured layer of the photo-curable ink.
A step of applying a brilliant ink containing a brilliant pigment having a number average particle diameter of 100 nm or less on the pre-cured layer of the photocurable ink to form a brilliant ink layer.
A step of main-curing the pre-cured layer by irradiating the pre-cured layer of the photo-curable ink with light or applying heat to form a cured layer of the photo-curable ink.
Image forming method having.
(3) The step according to (1) or (2) above, wherein the step of forming the cured layer of the photocurable ink is performed by irradiating light from the glittering ink layer side or applying heat. Image formation method.
(4) The recording medium is transparent, and the step of curing the photocurable ink layer to form a cured layer of the photocurable ink is performed by irradiating light from the recording medium side or applying heat. The image forming method according to (1) or (2) above, which is carried out by the above.
(5) The image forming method according to any one of (1) to (4) above, wherein the bright pigment has a spherical shape and a number average particle diameter of 40 nm or less.

400 Image forming device 401 Image forming device exterior 401c Device body cover 404 Cartridge holder 410 Main tank 410s, 410c, 410m, 410y For each color of silver (S), cyan (C), magenta (M), yellow (Y) Main tank 411 Ink storage container 413 Ink discharge port 414 Storage container case 420 Mechanical unit 434 Discharge head 436 Supply tube

Japanese Unexamined Patent Publication No. 2019-0388893 Japanese Unexamined Patent Publication No. 2019-051629 Japanese Unexamined Patent Publication No. 2012-179756 JP-A-2015-150739

Claims (5)

A process of applying photocurable ink on a recording medium to form a photocurable ink layer, and
A step of applying a brilliant ink containing a brilliant pigment having a number average particle diameter of 100 nm or less on the photocurable ink layer to form a brilliant ink layer.
A step of curing the photocurable ink layer by irradiating the photocurable ink layer with light or applying heat to form a cured layer of the photocurable ink.
Image forming method having. A process of applying photocurable ink on a recording medium to form a photocurable ink layer, and
A step of pre-curing the photo-curable ink layer by irradiating the photo-curable ink layer with light or applying heat to form a pre-cured layer of the photo-curable ink.
A step of applying a brilliant ink containing a brilliant pigment having a number average particle diameter of 100 nm or less on the pre-cured layer of the photocurable ink to form a brilliant ink layer.
A step of main-curing the pre-cured layer by irradiating the pre-cured layer of the photo-curable ink with light or applying heat to form a cured layer of the photo-curable ink.
Image forming method having. The image forming method according to claim 1 or 2, wherein the step of forming the cured layer of the photocurable ink is performed by irradiating light from the glittering ink layer side or applying heat. The recording medium is transparent, and the step of curing the photocurable ink layer to form a cured layer of the photocurable ink is performed by irradiating light from the recording medium side or applying heat. The image forming method according to claim 1 or 2. The image forming method according to any one of claims 1 to 4, wherein the bright pigment has a spherical shape and a number average particle diameter of 40 nm or less.

Images