JP2019126937A - Glossy image forming method and glossy image forming device - Google Patents

Abstract

To provide a glossy image forming method that can form a glossy image having higher glossiness by image formation in an intermediate transfer system through use of a metal ink composition and an intermediate transfer body.SOLUTION: The glossy image forming method includes the steps of: applying a metal ink composition containing metal nanoparticles using an ink jet head 128 to an ink application region provided on a surface of an intermediate transfer body 105 to form a metal glossy layer, the ink application region having a surface roughness Ra of more than or equal to 5 nm and less than or equal to 100 nm; applying an adhesion layer composition containing a resin component to the side of the metal glossy layer opposite to the intermediate transfer body using an ink jet head 138 to form an adhesion layer; and bringing the adhesion layer and a base material P into close contact with each other to transfer the adhesion layer and the metal glossy layer to a surface of the base material P.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gloss image forming method and a gloss image forming apparatus.

  Aluminum pigments, pearl pigments, and the like are used for the purpose of developing metallic luster in recorded materials such as labels, packages, publicly printed materials, and photographs. These pigments are applied as ink compositions by analog printing techniques, including offset printing, gravure printing, screen printing, etc., to form areas that emit metallic gloss colors in the recording.

  In recent years, nano-sized particles containing metal such as gold, silver, and copper (hereinafter, also simply referred to as “metal nanoparticles”) are used to produce a recorded material with a high-definition region that emits a metallic luster color. Many methods for forming an image using ink containing a glitter pigment (hereinafter also referred to as “metal ink composition”) are known. For example, Patent Document 1 discloses a method of forming a glossy image by an inkjet method on a non-ink-absorbent or low-absorbent recording medium using a metal ink composition containing silver nanoparticles. ing.

  In Patent Documents 2 and 3, a release layer is provided on a release film or sheet, and a metal ink composition is applied on the release layer by an inkjet method to form an image layer having glitter. Next, a thermal transfer medium is disclosed in which an adhesive layer is formed by applying a material containing an adhesive compound on the image layer. In image formation with this thermal transfer medium, the thermal transfer medium and the substrate are arranged so that the adhesive layer of the thermal transfer medium and the surface of the substrate face each other, and the thermal transfer medium and the substrate are bonded by heating. The image is transferred to the substrate by peeling off.

  Furthermore, in Patent Document 4, an ink in which metal particles are dispersed in a solvent is printed on a printing medium having a smooth printing surface to form a metallic ink layer containing metal particles on the printing surface side, and then A method for printing a metallic print is disclosed, which includes inverting the print medium and transferring the smooth metallic ink layer side to a transfer material as a display surface. Patent Document 4 also discloses that a metallic ink layer is transferred directly or indirectly via an adhesive layer to a transfer material.

JP2012-101491A JP 2012-148491 A JP 2012-162682 A JP 2012-166470 A

  When an image is directly formed on the surface of a substrate such as paper by an inkjet method using a metal ink composition as in Patent Document 1 described above, the glossiness of the image may be insufficient. In particular, when the smoothness of the surface of the substrate is low, the surface of the image formed thereon also becomes rough following the surface of the substrate, and therefore the glossiness is considered to be reduced.

  On the other hand, even if an image is formed by transfer according to the methods described in Patent Documents 2 to 4, sufficient gloss may not be obtained.

  The present invention has been made in view of the above problems, and a glossy image forming method capable of forming a glossy image having higher glossiness by image formation of an intermediate transfer method using a metal ink composition and an intermediate transfer member. It is an object of the present invention to provide a gloss image forming apparatus.

  A method for forming a glossy image for solving the above-described problem is a metal ink composition containing metal nanoparticles in an ink application region having a surface roughness Ra of 5 nm or more and 100 nm or less provided on the surface of an intermediate transfer member. Forming a metallic gloss layer, and applying an adhesive layer composition containing a resin component to the opposite side of the intermediate glossy body of the metallic gloss layer to form an adhesive layer; And a step of bringing the adhesion layer and the substrate into close contact with each other and transferring the adhesion layer and the metallic luster layer onto the surface of the substrate.

  In addition, a glossy image forming apparatus for solving the above problems includes an intermediate transfer body having an ink application region having a surface roughness Ra of 5 nm or more and 100 nm or less on a surface thereof, and a metal ink composition containing metal nanoparticles. A metallic gloss layer forming portion that is applied to the ink application region to form a metallic gloss layer, and an adhesion layer composition containing a resin component is applied to the opposite side of the metallic gloss layer to the intermediate transfer member to adhere An adhesion layer forming portion that forms a layer; a substrate conveyance portion that conveys a substrate to which the metallic gloss layer and the adhesion layer are transferred from the intermediate transfer body; and the adhesion layer and the substrate are adhered to each other. And a transfer portion for transferring the adhesion layer and the metallic gloss layer on the surface of the substrate.

  INDUSTRIAL APPLICABILITY According to the present invention, a glossy image forming method and gloss for forming a glossy image having excellent glossiness regardless of the type of substrate by forming an image by an intermediate transfer method using a metal ink composition and an intermediate transfer member. An image forming apparatus is provided.

FIG. 1 is a schematic diagram showing an outline of a glossy image forming apparatus according to an embodiment of the present invention.

  The glossiness of an image formed using metal nanoparticles greatly depends on the arrangement of the metal nanoparticles in the image. Also, the arrangement of metal nanoparticles in the image formed directly on the substrate is affected by the roughness of the surface of the substrate. Therefore, when an image is directly formed on a substrate having low smoothness by the method described in Patent Document 1 or the like, it is considered that the metal nanoparticles are difficult to finely arrange on the surface of the substrate, and the gloss of the obtained image is hardly enhanced. Be

  When forming an image using an intermediate transfer body, the metal nanoparticles are arranged on the surface of the intermediate transfer body, so the arrangement of metal nanoparticles in the formed image is affected by the roughness of the intermediate transfer body. receive. Therefore, if the surface of the intermediate transfer member is sparse, it is considered that the metal nanoparticles are difficult to be densely arranged in the image before transfer, and it is difficult to obtain an image with high glossiness. In addition, when forming a glossy image using metal nanoparticles, the surface of the intermediate transfer member is required when forming an image using an organic dye or the like in order to arrange the metal nanoparticles densely. It is thought that the roughness of is different.

  As a result of repeated experiments and considerations based on the above idea, the present inventor provided an ink application region having a surface roughness Ra of 5 nm to 100 nm on the surface of the intermediate transfer member, and a metal ink composition in the ink application region. It was found that the glossiness of an image containing metal nanoparticles can be sufficiently enhanced by forming an image with the addition of the above, and the present invention has been completed.

  Hereinafter, embodiments of the present invention will be described in detail.

1. TECHNICAL FIELD The present embodiment relates to a method for forming a glossy image. In the present embodiment, a metal ink composition containing metal nanoparticles is applied to an ink application region provided on the surface of an intermediate transfer member and having a surface roughness Ra of 5 nm or more and 100 nm or less to form a metallic gloss layer. Forming an adhesion layer by applying an adhesion layer composition containing a resin component on the opposite side of the metallic gloss layer to the intermediate transfer member, and forming the adhesion layer and the base material And a step of transferring the adhesion layer and the metallic gloss layer onto the surface of the base material by closely adhering.

1-1. Step of Forming a Metallic Gloss Layer In this step, a metallic ink composition containing metallic nanoparticles is applied to an ink application region provided on the surface of the intermediate transfer member and having a surface roughness Ra of 5 nm to 100 nm. .

1-1- (A) Intermediate Transfer Member The intermediate transfer member used in the present embodiment has an ink application region having a surface roughness Ra of 5 nm or more and 100 nm or less on at least a part of its surface. The shape of the intermediate transfer member is not particularly limited, and may be a sheet shape, a roller shape, a drum shape, a belt shape, or the like. When the intermediate transfer member is in the form of a belt, if it is in the form of an endless belt (endless belt), the same intermediate transfer member can be used continuously and repeatedly, which is extremely preferable from the viewpoint of productivity.

  The intermediate transfer member is a polyethylene terephthalate (PET) film, 1,4-polycyclohexylene dimethylene terephthalate film, polyethylene naphthalate (PEN) film, polyphenylene sulfide film, polystyrene (PS) film, polypropylene (PP) film, polysulfone Film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, cellulose derivative such as cellulose acetate, polyethylene (PE) film, polyvinyl chloride film, nylon film, nylon film, polyimide film, ionomer film, etc. preferable.

  The intermediate transfer body has an ink application region in which the surface roughness Ra, which is the center line average roughness, is 5 nm or more and 100 nm or less. The surface roughness Ra of the ink application region is preferably 10 nm or more and 80 nm or less. If the surface roughness Ra of the ink application area is 5 nm or more, the adhesion between the intermediate transfer member and the layer formed thereon is not too high, and transfer failure hardly occurs. Further, when the surface roughness Ra is 100 nm or less, the glossiness of the image due to the roughness of the surface of the intermediate transfer member hardly occurs.

  The surface roughness Ra of the ink application area is defined by the method defined in JIS B0601, and can be measured, for example, using a color 3D laser microscope VK-9700 (manufactured by Keyence Corporation).

  The ink application area may be provided on at least a part of the surface of the intermediate transfer member. Therefore, the surface roughness Ra of the entire surface of the intermediate transfer member may be in the above range (that is, the ink application region is provided in the entire intermediate transfer member), or the surface roughness Ra of only a portion thereof is in the above range It may be inside (that is, the ink application area is provided only in a part of the intermediate transfer member). When the ink application area is provided only in a part of the intermediate transfer member, the ink application area is assumed to exist in the entire area used for image formation.

  The ink application region can be formed by appropriately adjusting the type of resin used for the production of the intermediate transfer member and the production conditions so that the surface roughness Ra is 5 nm or more and 100 nm or less. In addition, the surface area Ra of the ink application region may be set to 5 nm or more and 100 nm or less by subjecting the surface layer of the intermediate transfer member to surface treatment, hot pressing, or physical or chemical polishing. It can be formed. In the case where an ink application region is provided in the entire intermediate transfer member, the surface roughness Ra of the intermediate transfer member can be adjusted by adjusting the type and amount of resin used for manufacturing the intermediate transfer member, the thickness of the surface layer, and the like It can be adjusted. Examples of the surface treatment include flame treatment, corona treatment, plasma treatment, polishing treatment, roughening treatment, active energy ray (UV / IR / RF, etc.) irradiation treatment, ozone treatment, surfactant treatment, silane coupling treatment. And organic-inorganic hybrid polymer treatment.

Of the above surface treatments, corona treatment and plasma treatment are preferred. If necessary, the intermediate transfer member may be provided with an undercoat layer (primer layer) on one side or both sides thereof. The primer treatment can be performed, for example, by applying a primer solution to an unstretched film at the time of film formation by melt extrusion of an intermediate transfer member that is a plastic film, and then stretching the film. The primer layer is, for example, a polyester resin, a polyacrylate resin, a polyvinyl acetate resin, a polyurethane resin, a styrene acrylate resin, a polyacrylamide resin, a polyamide resin, a polyether resin, a polystyrene resin, Polyethylene resins, polypropylene resins, polyvinyl chloride resins, polyvinyl alcohol resins, vinyl resins such as polyvinylidene chloride resins, polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral, cellulose resins, organic-inorganic hybrid resins, etc. It can be formed using Of these, the organic-inorganic hybrid polymer represented by RSiO _3/2 , which is particularly excellent in surface smoothness and interlayer adhesion, is preferable because of its high surface smoothness and interlayer adhesion. Among these, R is a mercapto. It is particularly preferable that it is an alkyl group having 1 to 6 carbon atoms having a group.

1-1- (B) Metal Ink Composition The metal ink composition used in the present embodiment contains metal nanoparticles, and if desired, a polymer dispersant that can be adsorbed to the metal nanoparticles and an emulsion resin. And a water based metal ink composition.

(1) Metal nanoparticles The metal nanoparticles are nano-sized metal particles, and the metal forming the metal nanoparticles may be any metal that exhibits a metallic luster when the metallic luster layer is formed.

  Examples of the above metals include gold, silver, copper, nickel, palladium, platinum, aluminum, zinc, chromium, iron, cobalt, molybdenum, zirconium, ruthenium, iridium, tantalum, mercury, indium, tin, lead, and tungsten, etc. Is included. Among them, gold, silver, copper, nickel, cobalt, tin, lead, chromium, zinc and aluminum are preferable because they can express high gloss and are inexpensive, and gold, silver, copper, tin, Chromium, lead and aluminum are more preferred, gold and silver are more preferred, and silver is particularly preferred. These metals can be used singly or in combination of two or more as an alloy or a mixture. In addition, two or more types of metal nanoparticles different in metal type or composition may be used in combination. The metal nanoparticles only need to contain these metals as main components, may contain a small amount of other components inevitably contained, and are surface-treated with citric acid or the like to improve dispersion stability. It is also good. Also, these metals may contain oxides.

The average particle size of the metal nanoparticles is not particularly limited, but it is preferably 3 nm or more and 100 nm or less, from the viewpoint of enhancing the dispersion stability and storage stability in the composition for producing the metallic gloss layer, and 10 nm The thickness is more preferably 80 nm or less, and still more preferably 15 nm to 50 nm. The average particle size of the metal nanoparticles can be the volume average particle size determined by the following procedure.
1) After applying a dispersion containing metal nanoparticles onto a glass plate, a sample obtained by vacuum degassing to volatilize the solvent component is subjected to SEM observation using JEOL JSM-7401F manufactured by JEOL Ltd. To measure the particle size of any 300 silver nanoparticles.
2) Based on the obtained measurement data, a particle size distribution based on volume is determined using image processing software Image J, and D50 (median diameter) thereof is taken as an average particle diameter (volume average particle diameter) in terms of volume.

  The content of the metal nanoparticles in the metal ink composition is not particularly limited, but from the viewpoint of sufficiently enhancing the ejection stability (dispersion stability) of the metal ink composition and the adhesion of the metal nanoparticles to the substrate, , Preferably from 1% by weight to 15% by weight, more preferably from 3% by weight to 12.5% by weight, and more preferably from 4% by weight to 10% by weight, based on the total weight of the metal ink composition. It is further preferred that

(2) Polymeric Dispersant The above-mentioned polymer dispersant is a compound having an adsorptive group capable of adsorbing to the surface of the above-mentioned metal nanoparticles and a hydrophilic structure.

  The polymer dispersant has an adsorptive group for adsorbing to the surface of metal nanoparticles. The above-mentioned adsorption group should just be a functional group which has strong adsorption power to the surface of metal particles. Examples of the adsorbing group include a primary to tertiary amino group, a quaternary ammonium group, a heterocyclic group having a basic nitrogen atom, a hydroxyl group, a carbonyl group, a carboxyl group, a phosphoric acid group, a sulfonic acid group, And thiol groups. The polymer dispersant can exhibit sufficient performance as a protective colloid of metal nanoparticles by having these adsorbing groups. The polymer dispersant preferably has an acid value. Examples of the polymer dispersant having an acid value include a polymer dispersant having a carboxyl group, a phosphate group, a sulfonate group, or the like as an adsorption group or a functional group. The acidic group is preferably a carboxyl group or a phosphoric acid group, more preferably a carboxyl group.

  The resin constituting the polymer dispersant is preferably a homopolymer or copolymer of a hydrophilic monomer. The copolymer of the hydrophilic monomer may be a copolymer of a hydrophilic monomer and a hydrophobic monomer.

  Examples of hydrophilic monomers include monomers containing a carboxyl group or an acid anhydride group ((meth) acrylic acid, unsaturated polyvalent carboxylic acids such as maleic acid, and maleic anhydride, etc.), and alkylene oxide modified (meth) ) Acrylic acid ester monomers (such as ethylene oxide-modified (meth) acrylic acid alkyl esters). In the present specification, (meth) acryl means both or one of acrylic and methacrylic.

  Examples of hydrophobic monomers include (meth) acrylate monomers such as methyl (meth) acrylate and ethyl (meth) acrylate, styrene monomers such as styrene, α-methylstyrene and vinyltoluene, ethylene, propylene And α-olefin monomers such as 1-butene, and carboxylic acid vinyl ester monomers such as vinyl acetate and vinyl butyrate.

  When the polymer dispersant is a copolymer, it may be a random copolymer, an alternating copolymer, a block copolymer, a comb copolymer, or the like. Among these, from the viewpoint of further improving the dispersibility of the metal nanoparticles, the polymer dispersant is preferably a comb block copolymer.

  The comb block copolymer means a copolymer including a linear polymer forming a main chain and another type of polymer grafted onto a constituent unit derived from a monomer constituting the main chain. Preferred examples of the comb block copolymer include a long chain containing a structural unit derived from a (meth) acrylic acid ester and a side chain containing a polyalkylene oxide group (such as an ethylene oxide-propylene oxide copolymer group). Included are comb-type block copolymers containing (chain polyalkylene oxide groups). In the comb-type block copolymer, since the graft-polymerized side chain causes steric hindrance, aggregation of metal nanoparticles can be further suppressed. As a result, the dispersibility of the metal nanoparticles is enhanced, and thus it is easier to suppress the ejection failure due to the aggregated metal nanoparticles.

  Further, the polymer dispersant preferably has an acid value of 1 mg KOH / g or more and 100 mg KOH / g or less. When the acid value is 1 mgKOH / g or more, the polymer dispersant has a tendency to be hydrophilic, so that the dispersibility of the metal nanoparticles in the water-based ink can be improved, and the ejection stability (dispersion of the water-based ink) Stability) can also be increased. On the other hand, when the acid value is 100 mgKOH / g or less, it is possible to solve a problem that may occur when a glossy layer is formed by an inject method as described later. For example, when the metallic gloss layer is formed by the ink jet method, it is possible to suppress a significant decrease in ejection stability (dispersion stability) from the ink jet head due to swelling of the polymer dispersant in the ink jet head. From the above viewpoint, the acid value of the polymer dispersant is preferably 3 mg KOH / g to 80 mg KOH / g, more preferably 5 mg KOH / g to 60 mg KOH / g, and more preferably 7 mg KOH / g to 50 mg KOH / g. It is more preferable that it is the following.

The acid value of the polymer dispersant may be measured according to JIS K 0070 using a stoichiometric method such as neutralization titration. Further, the type of the dispersant may be specified by Fourier transform infrared spectroscopy (FT-IR), ¹ H-NMR, and gas chromatography-mass spectrometry (GC / MS).

  The polymer dispersant preferably has a polyalkylene oxide structure in the molecule, and more preferably the above-mentioned comb block copolymer having a polyalkylene oxide group in a side chain. The polyalkylene oxide structure moderately reduces the cohesiveness of the metal nanoparticles due to steric hindrance. Thereby, it is considered that the water-based ink (or metal nanoparticles in the water-based ink) spreads moderately on the substrate and can form a smoother and higher gloss image.

  The polyalkylene oxide structure is preferably a polyalkylene oxide structure having 3 to 6 carbon atoms (polyethylene oxide structure, polypropylene oxide structure and polybutylene oxide structure). The polymer dispersant preferably has 3 or more and 80 or less polyalkylene oxide structures per molecule.

  The weight average molecular weight of the polymer dispersant is preferably 1,000 or more and 100,000 or less, and more preferably 2,000 or more and 50,000 or less.

  Examples of commercially available polymer dispersants include DISPERBYK-102, DISPERBYK-187, DISPERBYK-190, DISPERBYK-191, DISPERBYK-194N, DISPERBYK-199, DISPERBYK-2015, and DISPERBYK-2069 (all manufactured by BYK Chemie, "DISPERBYK" is a registered trademark of the company, EFKA 6220 (manufactured by BASF, "EFKA" is a registered trademark), and Solsperse 32000, Solsperse 44000, Solsperse 46000 (manufactured by Lubrizol), Floren TG-750W (Kyoeisha Chemical Company-made).

  The content of the above-mentioned polymer dispersant in the metal ink composition is not particularly limited, but from the viewpoint of sufficiently enhancing the dispersibility of metal nanoparticles in the metal ink composition and the adhesion to the substrate, metal nano It is preferably 1% by mass or more and 15% by mass or less, more preferably 2% by mass or more and 10% by mass or less, and further preferably 3% by mass or more and 8% by mass or less with respect to the total mass of the particles. preferable.

(3) Emulsion Resin The metal ink composition may contain an emulsion of an anionic resin as a binder resin. The emulsion resin interacts with the polymer dispersant adsorbed on the surface of the metal nanoparticles to enhance the adhesion of the metal nanoparticles to the substrate, and further, by the anti-discoloring agent adsorbed on the surface of the metal nanoparticles Decrease in glitter can be suppressed.

  The anionic resin is preferably a resin having high affinity with the polymer dispersant, and is a (meth) acrylic resin, urethane resin, polyolefin resin, polyester resin, polyvinyl chloride resin (for example, polyvinyl chloride polymer, Vinyl chloride-vinylidene chloride copolymer), epoxy resin, polysiloxane resin, fluorine resin, styrene copolymer (eg, styrene-butadiene copolymer, styrene- (meth) acrylate copolymer, etc.), and vinyl acetate A copolymer (for example, ethylene-vinyl acetate copolymer) can be appropriately selected and used. From the viewpoint of further improving the water resistance of the formed image, the anionic resin is composed of (meth) acrylic resin, urethane resin, polyolefin resin, polyvinyl chloride resin, epoxy resin, polysiloxane resin, fluorine resin, styrene copolymer. It is preferably selected from a coalescence and a vinyl acetate copolymer, and is preferably selected from a polyester resin, a urethane resin, and a (meth) acrylic resin.

  The anionic urethane resin is prepared by, for example, reacting a sulfonate-containing polyol (a1) and an organic polyisocyanate (a2) in an isocyanate group-excess atmosphere, and then adding a low-molecular polyol (a3-1) and an aqueous solvent. To obtain an emulsion of an isocyanate group-terminated prepolymer, and a low-molecular polyamine (a3-2) is added to the emulsion for further reaction.

  Examples of the sulfonate-containing polyol (a1) include sulfonate-containing polyester polyols, sulfonate-containing polyether polyols, and sulfonate-containing polycarbonate polyols.

  Examples of the organic polyisocyanate (a2) include aromatic diisocyanates including 4,4′-diphenylmethane diisocyanate and the like, aliphatic diisocyanates including 1,6-hexamethylene diisocyanate, and 1,4-tetramethylene diisocyanate and the like, o And aromatic aliphatic diisocyanates including, for example, xylene diisocyanate, m-xylene diisocyanate, and p-xylene diisocyanate, and alicyclic polyisocyanates including, for example, isophorone diisocyanate.

  The low molecular weight polyol (a3-1) and the low molecular weight polyamine (a3-2) may function as a chain extender. Examples of the low molecular polyol (a3-1) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, and 1,4-butanediol. Examples of the low molecular weight polyamine (a3-2) include ethylenediamine, propylenediamine, and diethylenetriamine.

  The aqueous solvent can be a mixed solvent of an organic solvent containing N-methylpyrrolidone (NMP) and propylene glycol dimethyl ether (DMPDG) and water.

  The (meth) acrylic resin can be obtained by polymerizing the monomer (b1) with the water-soluble initiator (b2) in an aqueous solution containing the polymeric emulsifier (b3).

  Examples of the monomer (b1) include (meth) acrylic acid alkyl ester containing methyl (meth) acrylate and ethyl (meth) acrylate, (meth) acrylic acid alkoxyalkyl ester containing methoxybutyl (meth) acrylate and the like. And aromatic vinyl compounds including styrene and α-methylstyrene, hydrolyzable silane group-containing vinyl compounds including vinyl triethoxysilane, and (meth) acrylamide compounds including N-methylol acrylamide and the like.

  Examples of the water-soluble initiator (b2) include sodium persulfate, potassium persulfate, and ammonium persulfate.

  The polymer emulsifier (b3) may be a water-soluble resin, and a carboxyl group-containing polymer can be used. The carboxyl group-containing polymer is a homopolymer of a carboxy group-containing unsaturated monomer or a copolymer of a carboxy group-containing unsaturated monomer and another monomer. Examples of the carboxy group-containing unsaturated monomer include (meth) acrylic acid. Examples of the monomer copolymerizable with the carboxy group-containing unsaturated monomer include those similar to the monomer (b).

  The emulsion resin may be a commercially available water dispersion resin. Examples of the commercially available water dispersion resin include SE841E and SE1658 (made by Taisei Fine Chemical Co., Ltd.) which are acrylic resin water dispersions, Vylonal MD1200 which is a polyester resin water dispersion, Vylonal MD1245 and Vylonal MD2000 (all are Toyobo Co., Ltd.). And “Vylonal” are registered trademarks of the company, and Superflex 210 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “Superflex” is a registered trademark of the company) is a polyurethane resin aqueous dispersion.

  The average particle diameter of the anionic resin emulsion is preferably 10 nm or more and 200 nm or less, and more preferably 30 nm or more and 100 nm or less. The average particle size of the emulsion can be a volume average particle size determined using a particle size distribution measuring apparatus based on a dynamic light scattering method.

  The solid content of the emulsion in the water-based ink is preferably 0.01% by mass or more and 0.1% by mass or less based on the total mass of the metal nanoparticles and the polymer dispersant. When the solid content is 0.01% by mass or more, the abrasion resistance of the formed image can be further improved. If the said solid content is 0.1 mass% or less, the brightness (reflectance) of the image formed can be raised more. From the above viewpoint, the solid content of the emulsion in the water-based ink is more preferably 0.02% by mass or more and 0.1% by mass or less, and 0.03% by mass or more and 0.1% by mass or less. Is more preferred.

(4) Dispersion medium The metal ink composition contains water as a dispersion medium. The dispersion medium is preferably water from the viewpoint of safety to the human body and ease of processing, but a known organic solvent may optionally be included together with water for viscosity adjustment and the like.

Examples of the organic solvent which may be contained in the ink include the following organic solvents.
Glycol ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether (DEGEE), diethylene glycol monobutyl ether (DEBE), triethylene glycol monomethyl ether, triethylene glycol monomethyl ether. Ethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether (tetra EGME), tetraethylene glycol monoethyl ether (tetra EGEE), tetraethylene glycol monopropyl ether (tetra EGPE), tetraethylene glycol monobutyl ether (tetra EGBE) , B propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether (DPGME), dipropylene glycol monoethyl ether (DPGEE), dipropylene glycol monopropyl ether (DPGPE),
Examples of polyhydric alcohols include ethylene glycol, glycerin, 2-ethyl-2- (hydroxymethyl) -1,3-propanediol, tetraethylene glycol, triethylene glycol, tripropylene glycol, and 1,2,4-butanetriol. , Diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, 1,6-hexanediol, 1,2-hexanediol, 1,5-pentanediol, 1,2-pentanediol, 2,2-dimethyl-1,3 -Propanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 3-methyl-1,3-butanediol, 2-methylpentane-2,4-diol, 2- Methyl-1,3-propanediol,
Amines (ethanolamine, 2- (dimethylamino) ethanol, etc.), monohydric alcohols (methanol, ethanol, butanol, etc.), 2,2′-thiodiethanol, sulfolane, amides (N, N-dimethylformamide, etc.) , Heterocyclic rings (2-pyrrolidone, γ-butyrolactone, propylene carbonate, ethylene carbonate, etc.), acetonitrile and the like. These organic solvents can be used alone or in admixture of two or more.

  From the viewpoint of suppressing the occurrence of nozzle clogging due to drying of the water-based ink near the nozzle when discharging from the inkjet head when forming the metallic gloss layer by the inkjet method, the organic solvent contains a polyhydric alcohol. Is preferred. At this time, the content of the polyhydric alcohol in the aqueous ink is preferably 1% by mass or more and 10% by mass or less with respect to the total mass of the aqueous ink.

  When the organic solvent described above is contained in the ink, it is preferably 20% by mass or more and 50% by mass or less, and preferably 30% by mass or more and 50% by mass or less with respect to the total mass of the metal ink composition. More preferable.

(5) Other components The metal ink composition may contain a known surfactant (surface conditioner), thickener, leveling agent, preservative and the like. The metal ink composition may contain other additives such as inorganic fine particles, organic fine particles, mold release agents, dispersants, antistatic agents and the like, as long as the gloss is not significantly reduced.

  Examples of surfactants include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates and fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols and polyoxy acids Nonionic surfactants such as ethylene / polyoxypropylene block copolymers, cationic surfactants such as alkylamine salts and quaternary ammonium salts, and silicone-based and fluorine-based surfactants are included.

  Examples of commercially available silicone-based surfactants include KF-351A, KF-352A, KF-642 and X-22-4272, Shin-Etsu Chemical, BYK 307, BYK 345, BYK 347 and BYK 348, Big Chemie ("BYK "Is a registered trademark of the same company), as well as TSF4452, manufactured by Toshiba Silicone.

  The content of the surfactant, thickener, leveling agent, preservative, additive and the like is, for example, 0.001% by mass or more and less than 1.0% by mass with respect to the total mass of the metal ink composition, for example. be able to.

  However, from the viewpoint of further increasing the reflectance of the metallic gloss layer, the ink composition contains substantially the metal nanoparticles adsorbed with the polymer dispersant, the emulsion and solvent of the anionic resin, and optionally the required amount. It is preferable to consist of these surfactants. The total content of the metal nanoparticles adsorbed by the polymer dispersant, the emulsion of the anionic resin, and the solvent is preferably 90% by mass to 100% by mass with respect to the total mass of the ink composition. And 95% by mass or more and 100% by mass or less.

(6) Physical Properties The viscosity of the above metal ink composition is preferably 1 cP or more and less than 100 cP, more preferably 1 cP or more and 50 cP or less, and more preferably 1 cP or more and 15 cP or less More preferably. If the viscosity of the metal ink composition is within the above range, it is considered that the ejection stability from the nozzles of the inkjet head is good even when the glossy layer is formed by the inkjet method.

  Furthermore, from the viewpoint of improving the ejection stability from the nozzles of the inkjet head, the surface tension of the metal ink composition is preferably 20 mN / m or more and 50 mN / m or less. From the viewpoint of enhancing the wettability with respect to the intermediate transfer member and making the formed image higher definition, the surface tension of the metal ink composition is more preferably 20 mN / m or more and 35 mN / m or less. The surface tension of the metal ink composition can be adjusted to the above range by changing the type or amount of the organic solvent or surfactant.

1-1- (C) Formation of Metallic Gloss Layer In the step, the metallic ink composition described above is applied to the ink application region provided on the surface of the intermediate transfer body described above to form a metallic gloss layer. The step, the step of forming an adhesion layer described later, and the step of forming a protective layer that is performed as desired are performed in a state where at least the ink application region of the intermediate transfer member is maintained horizontally. By forming the metallic gloss layer on the intermediate transfer member (ink application region) kept horizontal, it is possible to form a highly glossy image.

  The method for applying the metal ink composition to the ink application region of the intermediate transfer member is not particularly limited, and methods using analog printing including offset printing, gravure printing, and screen printing, gravure coaters, roll coaters, wire bars, etc. are used. And digital printing methods such as an inkjet method. The inkjet method is preferable from the viewpoint of forming a finer image and from the viewpoint of enhancing the glossiness of the image by easily arranging the metal nanoparticles more densely.

  The discharge method of the metal ink composition from the ink jet head may be either an on-demand method or a continuous method. On-demand inkjet heads include single-cavity, double-cavity, bender, piston, shear mode and shared wall electro-mechanical conversion systems, as well as thermal inkjets and bubble jets (bubble jets). It may be any of an electric-heat conversion system such as a Canon Inc. registered trademark type.

  In this step, the metal ink composition applied on the ink application region may be dried. The drying temperature at this time is preferably 30 ° C. or more and less than 100 ° C., and more preferably 30 ° C. or more and less than 80 ° C. By this step, a metallic luster layer is formed.

  Further, the dried ink may be heated. In particular, when emulsion resin particles are contained in the ink used, it is preferable to heat-fuse the emulsion resin particles by heating.

  The heating temperature of the ink may be any temperature at which the emulsion resin particles can be thermally fused, and is preferably set to be equal to or higher than the glass transition temperature of the emulsion resin particles. Specifically, the heating temperature is preferably 40 ° C. or higher, for example, and the upper limit temperature needs to be equal to or lower than the heat resistance temperature of the base material and the emulsion resin particles. Further, it is possible to form a film at a Tg or less of the emulsion resin particles by further adding a film forming aid to the ink. The upper limit of the heating temperature is not particularly limited as long as it does not cause deformation of the intermediate transfer member, but can be, for example, 100 ° C. or less.

  The drying step and the heating step may be performed separately or may be performed simultaneously. When drying and heating are performed simultaneously, it is preferable that the drying and heating temperature be equal to or higher than the glass transition temperature of the emulsion resin particles.

  The thickness of the metallic luster layer is preferably 0.05 μm or more and 0.5 μm or less, and more preferably 0.08 μm or more and 0.3 μm. By setting the thickness of the metallic gloss layer to the above-mentioned numerical range, it is possible to improve the thin line printability and the printability on a transferred object having unevenness on the surface while improving the glossiness.

1-2. Step of forming an adhesion layer In this step, an adhesion layer composition containing a resin component is applied to the opposite side of the metallic gloss layer to the intermediate transfer member to form an adhesion layer. By forming the adhesion layer, the image formed on the ink application region of the intermediate transfer body is brought into close contact with the substrate, and the image can be transferred to the substrate.

1-2 (A) Adhesion layer composition The adhesion layer composition used in the present embodiment has an adhesion property for adhering an image and a transfer destination substrate after forming the adhesion layer. It is. If the adhesion is stronger than the adhesion between the intermediate transfer member and the image, the image can be easily transferred from the intermediate transfer member.

  A composition containing a compound having adhesiveness can be used as an adhesive layer composition. Examples of compounds that can be used in the adhesive layer composition include ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polybutadiene resin, styrene-butadiene copolymer (SBR), styrene-ethylene-butene- Styrene copolymer (SEBS), acrylonitrile-butadiene copolymer (NBR), polyisoprene resin (IR), styrene-isoprene copolymer (SIS), acrylic ester copolymer, polyester resin, polyurethane resin, acrylic resin , Butyl rubber, and polynorbornene. Further, the adhesion layer is preferably formed of a thermoplastic resin having a Vicat softening point of 80 ° C. or less.

  Among these, polyester resins are preferable from the viewpoint of maintaining the smoothness of the metallic gloss layer and obtaining an image having high gloss.

  The Mn of the polyester resin is preferably 2000 or more and 25000 or less, and more preferably 3000 or more and 20000 or less. By setting the Mn of the polyester-based resin contained in the adhesive layer to the above numerical range, it is possible to improve the solvent resistance and the abrasion resistance while maintaining the transferability of the intermediate transfer member.

  Moreover, it is preferable that Tg of the said polyester-type resin is 20 to 90 degreeC, and it is more preferable that it is 50 to 80 degreeC. By setting the Tg of the polyester resin to the above numerical range, the transferability can be improved while the smoothness can be increased.

  The content of the polyester resin with respect to the total mass of the adhesion layer is preferably 50% by mass or more and 100% by mass or less, and more preferably 70% by mass or more and 100% by mass or less. By making content of the polyester-type resin in a contact | adherence layer into the said numerical range, adhesiveness with a to-be-transferred body and adhesiveness with a metallic luster layer body can be improved more.

  The adhesion layer may contain other resins or additives as long as the effects of the present invention are not impaired. Examples of such a resin include acrylic resins, polyurethane resins, vinyl resins, cellulose resins, melamine resins, polyamide resins, polyolefin resins, and styrene resins.

  Examples of the above additives include low melting substances such as waxes and plasticizers. Specific examples of the additive include phthalic acid ester, adipic acid ester, glycol ester, fatty acid ester, phosphoric acid ester, and chlorinated paraffin. The amount of these additives added is not particularly limited as long as it is selected in an amount necessary to develop preferable physical properties in combination with the material of the base adhesive layer, but generally the total mass of the adhesive layer It is preferably 10% by mass or less, and more preferably 5% by mass or less.

  The adhesion layer can improve transferability of the metallic gloss layer to printing paper having a large surface roughness. Printing paper usually has a roughness of Ra of 0.1 μm or more, and mat paper or fine paper has irregularities of 1 μm or more. From the viewpoint of causing the transfer layer to follow these irregularities, the thickness of the adhesion layer is preferably 10 μm or more, and more preferably 15 μm or more. Further, when retransferring to another transfer target (for example, paper such as plain paper or Japanese paper) having a large roughness, the thickness of the adhesion layer is preferably 30 μm or more. The upper limit of the film thickness of the adhesion layer is preferably 50 μm, more preferably 20 μm.

  By setting the thickness of the adhesion layer in the above numerical range, smoothness can be improved, a high gloss image can be obtained, and fine line reproducibility can be improved.

  Said material can be made to melt | dissolve in a solvent as needed, and can be set as an adhesion layer composition. As the solvent, acetone, methyl ethyl ketone, toluene, xylene and the like can be used.

  Alternatively, the adhesion layer can be formed by applying and drying latex ink containing latex resin particles by the method described above. The latex resin particles may have any of a uniform structure, a matrix structure, and a core-shell structure, but core-shell type latex resin particles are particularly preferable. The core-shell type latex resin particles have a shell layer containing a molten resin and a core containing an elastic resin. By using an elastic resin for the core, the adhesion layer is easily deformed at the temperature at the time of transfer, and the substrate having irregularities is deformed following the irregularities, thereby improving the smoothness of the metallic luster layer. can do. Furthermore, the shell layer made of a molten resin can sufficiently adhere the metallic luster layer and the adhesion layer, and can sufficiently adhere the adhesion layer and the substrate.

  In the latex ink, the core-shell type latex resin particles are preferably contained in an amount of 1% by mass or more and 25% by mass or less, more preferably 3% by mass or more and 20% by mass or less based on the total mass of the latex ink. More preferably, the content is from 18% to 18% by mass. When the amount of the core-shell type latex resin particles is in the above range, the balance between the drying speed and the viscosity increase of the latex ink tends to be in the desired range, the printability of the latex ink tends to be good, and the adhesion of the desired thickness It is easy to get a layer. The viscosity of the latex ink is appropriately selected according to the coating method of the latex ink, but is preferably 1 cps or more and 30 cps or less, and more preferably 2 cps or more and 20 cps or less.

  The core-shell type latex resin particles have a volume-based median diameter of preferably 50 nm to 500 nm, more preferably 70 nm to 300 nm, and still more preferably 80 nm to 250 nm. When the median diameter of the core-shell type latex resin particles is in the above range, nozzle clogging or the like hardly occurs when the latex ink containing the core-shell type latex resin particles is discharged from the coating apparatus. The volume-based median diameter of the core-shell type latex resin particles can be measured using “UPA-150” (manufactured by Microtrack).

(core)
The shape of the core of the core-shell latex resin particles is not particularly limited, but is preferably approximately spherical. The volume-based median diameter of the core is preferably 30 nm or more and 480 nm or less, more preferably 50 nm or more and 280 nm or less, and further preferably 60 nm or more and 230 nm or less. The volume-based median diameter of the core can be measured using “UPA-150” (manufactured by Microtrac).

  The amount of the elastic resin relative to the total mass of the core-shell type latex resin particles is preferably 2% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 20% by mass or less, and more preferably 4% by mass or more. More preferably, it is 10 mass% or less. If the amount of the elastic resin is less than 2% by mass, it becomes difficult to maintain the shape of the adhesive layer even if heat is applied during transfer, and if it exceeds 10% by mass, the deformation becomes too large and the resolution decreases.

The elastic resin is a thermoplastic resin which has the property of being softened by heating to exhibit plasticity and solidified by cooling, and the storage elastic modulus G ′ (120) at 120 ° C. is 1 × 10 ⁴ to 1 × 10 ^It refers to a resin that is ⁶ dyn / cm ² . The storage elastic modulus G ′ (120) is more preferably 1 × 10 ^{4 to} 0.5 × 10 ⁵ dyn / cm ² . When the storage elastic modulus G ′ (120) is 1 × 10 ⁴ dyn / cm ² or more, the adhesive layer obtained from the latex ink coating film is hardly deformed by heat during foil transfer. As a result, it becomes easy to transfer the foil into a high-definition pattern. On the other hand, if the storage elastic modulus G '(120) of the core is excessively high, the foil can not be deformed even by the pressure at the time of transfer of the foil, and the adhesion of the foil decreases and the smoothness of the transfer surface is inferior. There are problems such as. On the other hand, as in this embodiment, when the elastic modulus of the core is 1 × 10 ⁶ dyn / cm ² or less, the core is deformed to some extent by the pressure during the transfer of the foil. The balance of the suppression of sex becomes suitable. The storage elastic modulus G ′ (120) of the elastic resin is appropriately adjusted according to the weight average molecular weight (polymerization degree) of the elastic resin.

  The storage elastic modulus G ′ (120) is measured by the following methods (1) to (4). The measurement is performed by a dynamic viscoelasticity measuring device.

(1) A dispersion of elastic resin (core) particles is placed in a measurement sample petri dish at 20 ± 1 ° C. and leveled. The petri dish is allowed to stand for 24 hours or more in an environment with a relative humidity of 50 ± 5% Rh. Take 0.6 g of a sample from the petri dish and load it into a compression molding machine. Then, a load of 3 t is applied for 30 seconds to produce a pellet of 1 cm in diameter.
(2) The pellet is loaded on a parallel plate of 0.977 cm in diameter.
(3) The measuring section temperature of the dynamic viscoelasticity measuring device is set to a temperature 20 ° C. lower than the softening point of the elastic resin measured by the method described later (softening point−20 ° C.), and the parallel plate gap is set to 3 mm. Compact the pellet.
(4) Thereafter, the measurement part temperature is set to 35 ° C., and the pellet is allowed to cool to 35 ° C. Then, while applying a sinusoidal vibration having a frequency of 1.0 Hz, the temperature of the measurement unit is increased at 5 ° C./min to 200 ° C. At this time, the complex elastic modulus G * at 120 to 150 ° C. is measured, and the storage elastic modulus G ′ (120) is obtained therefrom. The strain angle is controlled by automatic strain control of the measuring device.

  Here, the softening point of the above-mentioned elastic resin is measured by the flow tester method by the following method. The dispersion of elastic resin particles described above is placed in a measuring sample petri dish at a temperature of 20 ± 1 ° C. and flattened. The petri dish is allowed to stand for 12 hours or more in an environment with a relative humidity of 50 ± 5% Rh. Take 1.1 g of a sample from the petri dish and load it into a compression molding machine. Then, a load of 3 t is applied for 30 seconds to prepare a pellet of 1 cm in diameter.

  The sample is then placed in an environment of 24 ± 5 ° C. and a relative humidity of 50 ± 20% RH. Then, using a flow tester (for example, CFT-500D (manufactured by Shimadzu Corporation)), a cylindrical die with a load of 196 N (20 kg weight), a start temperature of 80 ° C., a remaining heat time of 300 seconds and a temperature rising rate of 6 ° C./min. From (1 mm × 1 mm), a piston with a diameter of 1 cm is extruded, and the temperature at which the offset value is 5 mm is taken as the softening point.

  The elastic resin may be a crystalline resin having a melting point, or may be any amorphous resin having a glass transition point without having a melting point. In the present embodiment, the crystalline resin refers to a resin having a clear endothermic peak rather than a stepwise endothermic change in differential scanning calorimetry (DSC). A clear endothermic peak is a peak whose half-width of the endothermic peak is within 15 ° C. when measured by differential scanning calorimetry (DSC) at a temperature rising rate of 10 ° C./min. In addition, the amorphous resin refers to a resin other than the crystalline resin which does not have a clear peak in the above-mentioned DSC.

  Examples of elastic resins contained in the core include styrene resins, (meth) acrylic resins, styrene- (meth) acrylic copolymer resins, vinyl resins such as olefin resins, polyester resins, and polyamide resins. , Known thermoplastic resins such as polycarbonate resin, polyether resin, polyvinyl acetate resin, polysulfone resin, polyurethane resin and the like are included. The core may contain only one kind of these resins or two or more kinds.

  The elastic resin contained in the core is a styrenic resin from the viewpoint of easy adjustment of the degree of polymerization for adjusting the storage elastic modulus G ′ (120) and good dispersibility after particle formation, A (meth) acrylic resin, a polyester resin, or a styrene- (meth) acrylic copolymer resin is preferable, and a styrene- (meth) acrylic copolymer resin is particularly preferable.

(Shell layer)
The shell layer of the core-shell latex resin particles is a layer formed around the core, and may be a layer completely covering the core or a layer covering only a part of the core. The shell layer contains a molten resin.

  In addition, it is preferable that the quantity of molten resin is 90-98 mass% with respect to the mass of the whole core-shell type latex resin, More preferably, it is 92-97 mass%, More preferably, it is 93-96 mass%. When the amount of the molten resin is 90% by mass or more, the adhesiveness of the foil or the like tends to be enhanced. On the other hand, when the amount of the molten resin is 98% by mass or less, the amount of the elastic resin is relatively sufficient, and the shape of the adhesive layer is easily maintained during the transfer of the foil.

  In the present embodiment, the molten resin is a thermoplastic resin having a melting point or glass transition temperature of 65 ° C. or less. The melting point or glass transition temperature of the molten resin is preferably 25 to 60 ° C., more preferably 30 to 50 ° C. When the melting point or glass transition temperature of the molten resin is 65 ° C. or lower, the shell layer is softened when the foil is transferred, and the adhesion to the foil or the substrate is increased. The melting point or glass transition temperature of the molten resin is adjusted by the weight average molecular weight (polymerization degree) of the molten resin, the type of the molten resin, and the like. The melting point or glass transition temperature of the shell layer is measured by differential scanning calorimetry (DSC).

  Here, the molten resin is, for example, a styrene resin, (meth) acrylic resin, styrene- (meth) acrylic copolymer resin, vinyl resin such as olefin resin, polyester resin, polyamide resin, polycarbonate resin, It may be a known thermoplastic resin such as polyether, polyvinyl acetate resin, polysulfone resin, polyurethane resin and the like. The core may contain only one kind of these resins or two or more kinds.

  Among these, a styrene resin, a (meth) acrylic resin, a polyester resin, or a styrene- (meth) acrylic copolymer resin has a low viscosity when melted and has a high sharp melt property. In particular, a styrene- (meth) acrylic copolymer resin is preferable.

(Preparation method of core-shell type latex resin particles)
The core-shell type latex resin particles can be produced in the same manner as the known method of producing core-shell type particles, but are preferably produced by the emulsion polymerization method from the viewpoint of particle controllability and dispersibility after particle formation.

  The latex ink contains a surfactant, an anti-drying agent (wetting agent), an anti-fading agent, an emulsion stabilizer, a penetration accelerator, an ultraviolet absorber, and a preservative as long as the glossiness of the formed image is not significantly impaired. Additives such as an agent, an antifungal agent, a pH adjuster, a surface tension adjuster, an antifoaming agent, a viscosity adjuster, a dispersant, a dispersion stabilizer, an antirust agent, and a chelating agent may be included.

1-2- (B) Formation of adhesion layer In the said process, the above-mentioned adhesion layer composition is given to the surface of the metallic luster layer mentioned above, and then it heats and dries to the temperature of 30 degreeC or more and 150 degrees C or less Form an adhesion layer. The application method is not particularly limited, but is a method by analog printing including offset printing, gravure printing, screen printing, etc., a method using a gravure coater, a roll coater, a wire bar, etc., a method by digital printing such as an inkjet method Is mentioned.

1-3. Transfer process In this process, the adhesion layer and the substrate are brought into close contact with each other, and the adhesion layer and the metallic luster layer are transferred onto the surface of the substrate.

  The substrate is not particularly limited, and may be a paper substrate with high water absorption, or a substrate with low water absorption such as gravure or coated paper for offset printing, or a film, plastic board (soft vinyl chloride, hard vinyl chloride) And water-absorptive substrates such as acrylic plates, polyolefins, etc.), glass, tiles and rubbers.

  Examples of the film include known plastic films. Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polyethylene films including high density polyethylene films and low density polyethylene films, polypropylene films, polyamide films such as nylon, polystyrene films, ethylene / vinyl acetate copolymer Included are biodegradable films such as combined (EVA) film, polyvinyl chloride (PVC) film, polyvinyl alcohol (PVA) film, polyacrylic acid (PAA) film, polycarbonate film, polyacrylonitrile film, and polylactic acid film . In order to impart gas barrier properties, moisture proof properties, and fragrance retention properties, polyvinylidene chloride may be coated on one or both surfaces of the film, or a metal oxide may be deposited. In addition, the film may be subjected to antifogging treatment. In addition, the film may be subjected to corona discharge and ozone treatment.

  The film may be a multilayer substrate in which a layer such as a PVA coat is provided on the surface of an absorbent substrate such as paper so that a region to be recorded is non-absorbable.

  The thickness of the film is preferably less than 0.25 mm.

  The transfer step can be performed while applying pressure with a roller or the like in order to uniformly adhere the adhesion layer and the substrate and to enhance the adhesion. In addition, in order to accelerate the drying or curing of the adhesion layer in close contact with the substrate, the transfer step can be performed while heating.

  Furthermore, depending on the type of resin component contained in the glossy ink composition and the adhesive layer composition, the glossy image formed product after the transfer step is subjected to a treatment such as heating or light (UV) irradiation to obtain a glossy layer. It is also possible to increase the strength of the adhesion layer.

1-4. Step of forming protective layer In the present embodiment, before the step of forming the metallic luster layer, the step of forming the protective layer by applying the protective layer composition to the ink application region of the intermediate transfer member is performed. Can do.

  The protective layer is a layer for protecting the glitter image after transfer. By providing the protective layer, the weather resistance of the glitter image can be improved.

  The protective layer used in the present embodiment is preferably formed from a resin or wax having a glass transition temperature (hereinafter abbreviated as Tg) of 40 ° C. or higher. A resin or wax having a Tg of 40 ° C. or higher can more effectively suppress thermal damage during thermal transfer printing and make it difficult to reduce the metallic gloss, as well as tailing and registration deviation of printing due to a reduction in printing resolution. The possibility of occurrence of printing defects can be further reduced. Tg can be a value measured based on a plastic transition temperature measurement method defined in JIS K7121.

  The thickness of the protective layer is preferably 0.5 μm or more and 30 μm or less, and more preferably 1 μm or more and 20 μm or less. By setting the thickness of the protective layer to 0.5 μm or more, it is possible to reduce the corrosion deterioration rate of the metallic gloss layer after being transferred to the base material, and to further enhance the effect of suppressing the metallic gloss reduction. Further, by setting the thickness of the protective layer to 30 μm or less, the thermal response at the time of thermal transfer printing can be accelerated and the transfer efficiency can be maintained high.

  Examples of the above resin include ethylene / vinyl acetate copolymer, vinyl chloride / vinyl acetate copolymer, acrylic resin, acrylic polyester resin, polyester resin, polyamide resin, epoxy resin, cellulose resin, petroleum Resin, rosin resin, terpene resin, polyvinyl acetate resin, chroman / indene resin, styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene -Styrene block copolymers such as butylene-styrene block copolymer (SEBS), polybutadiene rubber and the like are included. These resins may be used alone or in combination of two or more.

  Examples of the wax include lanolin, natural waxes such as carnauba wax and candelilla wax, petroleum waxes such as paraffin wax and microcrystalline wax, oxidized waxes, synthetic ester waxes, polyethylene waxes, α-olefins and maleic anhydride co Included are synthetic waxes such as polymer waxes. These waxes may be used alone or in combination of two or more. Moreover, you may use together the said resin and the said wax.

  Of these, acrylic resins, acrylic polyester resins and polyester resins are particularly preferred from the standpoint of printing resolution or adhesion to the metallic luster layer.

  In order to enable on-line operation, the protective layer is preferably formed by thermal transfer printing. However, the protective layer may be formed by a method using analog printing including offset printing, gravure printing, and screen printing, a method using a gravure coater, a roll coater, a wire bar, etc., a method using digital printing such as an inkjet method, and the like. Good. From the viewpoint of further improving the surface smoothness of the protective layer, the protective layer is preferably formed by thermal transfer printing or coating using a coater such as a gravure coater, roll coater, or wire bar.

  It is considered that the roughness of the surface of the intermediate transfer member is reflected almost as it is on the surface of the protective layer formed by these methods.

  In order to protect the image, a protective layer is preferably provided to cover the entire image. Thus, the protective layer composition can be applied to a part (only the part on which an image is formed) or the whole of the ink application area.

2. Glossy Image Forming Device This embodiment relates to a device for carrying out the above-described glossy image forming method.

  FIG. 1 is a schematic view showing an outline of a glossy image forming apparatus according to the present embodiment. The gloss image forming apparatus 100 is an apparatus for transferring a gloss image to the base material P transported on the transport path 200 to form a gloss image on the base material P, and includes the intermediate transfer body 105, the protective layer forming unit 110, and metal. The gloss layer forming unit 120, the adhesion layer forming unit 130, the drying unit 140, and the transfer unit 150 are included.

  The intermediate transfer member 105 is an endless belt-like intermediate transfer member having the above-described configuration. The intermediate transfer member 105 has an ink application region having a surface roughness Ra of 5 nm or more and 100 nm or less on at least a part of the surface. The shape of the intermediate transfer member 105 can be a sheet shape, a roller shape, a drum shape, a belt shape, or the like.

  The intermediate transfer member 105 may be subjected to the above-described surface treatment in order to improve the adhesion with the metallic gloss layer (or protective layer). In addition, the ink application region may be provided on at least a part of the surface of the intermediate transfer member 105. The ink application region can be formed by appropriately adjusting the type of resin used for manufacturing the intermediate transfer member 105 and the manufacturing conditions so that the surface roughness Ra is 5 nm or more and 100 nm or less. In addition, the surface area Ra of the ink application region should be 5 nm or more and 100 nm or less by subjecting the surface layer of the intermediate transfer member 105 to surface treatment, hot pressing, or physical or chemical polishing. It can also be formed.

  The protective layer forming unit 110 forms the above-described protective layer on the surface (ink application region) of the intermediate transfer member 105. In this embodiment, the protective layer forming unit 110 includes a supply roller 112, a thermal transfer roller 114, a release roller 116, and a collection roller 118, and forms a protective layer by thermal transfer printing. The supply roller 112 supplies a film-like protective layer applied to the surface of the base film, and brings the protective layer into contact with the surface of the intermediate transfer member 105 that moves (rotates). The thermal transfer roller 114 heat-presses the protective layer in contact with the surface of the intermediate transfer member 105 from the base film side, thereby bringing the intermediate transfer member 105 and the protective layer into close contact with each other. The release roller 116 and the collection roller 118 collect the base film.

  The protective layer forming unit 110 may form a protective layer by coating using a coater such as a gravure coater, roll coater, or wire bar, or may form a protective layer by an inkjet method or the like.

  Further, when a protective layer is unnecessary for the image to be formed, the protective layer forming unit 110 can be omitted.

  The metallic gloss layer forming unit 120 applies the above-described metallic ink composition to the surface of the ink application region of the intermediate transfer member 105 (when the protective layer is formed on the surface of the ink application region, the surface of the protective layer). Then, a metallic luster layer is formed. In this embodiment, the metallic gloss layer forming unit 120 includes an ink tank 122, an ink supply pipe 124, an ink supply tank 126, and an inkjet head 128, and applies a metallic ink composition by an inkjet method.

  The metallic gloss layer forming unit 120 may form a metallic gloss layer by applying a metal ink composition by a method using a gravure coater, a roll coater, or a wire bar.

  In addition, the metallic gloss layer forming unit 120 may have a drying unit that dries the applied metal ink composition.

  The adhesion layer forming unit 130 applies the above-mentioned adhesion layer composition to the surface of the metallic gloss layer (the surface of the metallic gloss layer opposite to the intermediate transfer member 105) to form an adhesion layer. In the present embodiment, the adhesion layer forming unit 130 includes the ink tank 132, the ink supply pipe 134, the ink supply tank 136, and the ink jet head 138, and applies the adhesion layer composition by the ink jet method.

  In addition, the adhesion layer formation part 130 may provide an adhesion layer composition by the method using a gravure coater, a roll coater, a wire bar, etc., and may form an adhesion layer.

  The drying unit 140 dries the formed metallic gloss layer and the adhesive layer. In the present embodiment, the drying unit 140 dries the metallic gloss layer and the adhesion layer with an infrared lamp.

  The transfer unit 150 presses the metallic gloss layer and the adhesion layer formed in the ink application area of the intermediate transfer member 105 against the substrate P by the pressure roller 152 and transfers the substrate P to the substrate P.

  Hereinafter, specific examples of the present invention will be described together with comparative examples, but the present invention is not limited thereto.

1. Preparation of intermediate transfer member (Intermediate transfer member 1)
A varnish containing an organic-inorganic hybrid resin having a polysiloxane structure not having a silsesquioxane structure and a polyfunctional acrylate-based curing agent (Arakawa Chemical Industries Co., Ltd., product name “Beamset 907D, viscosity: 3 cps”), type II On a liquid crystal polymer film (manufactured by Primatec, product name “BIAC BC50”, thickness: 50 μm), a roll coater was used to coat with a thickness of about 15 μm. The coated film was dried at 90 ° C. for 60 seconds, and then the varnish was cured with 300 mJ / cm ² of UV to obtain an intermediate transfer body 1. The intermediate transfer member 1 had a surface roughness Ra of 5 nm.

(Intermediate transfer member 2)
An intermediate transfer member 2 was obtained in the same manner as the intermediate transfer member 1 except that the coat thickness of the varnish was changed to about 10 μm. The intermediate transfer member 2 had a surface roughness Ra of 10 nm.

(Intermediate transfer body 3)
Silsesquioxane having an HS-C3H6-group as an organic group (Arakawa Chemical Industries, product name “Composeran SQ107”) 35 parts by mass, triallyl isocyanurate (Nippon Kasei Co., Ltd.) 15 parts by mass, ethylene glycol as a solvent Varnish was prepared by mixing 50 parts by mass of dimethyl ether and 0.08 parts by mass of 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF, product name “Irgacure 184”) as a photopolymerization initiator. The viscosity of the varnish was 2 cps. The varnish was coated on a type II liquid crystal polymer film (manufactured by Primatec, product name “BIAC BC50”, thickness: 50 μm) with a thickness of about 5 μm in a wet state using a bar coater. The coated film was dried at 90 ° C. for 60 seconds, and then the varnish was cured with 300 mJ / cm ² of UV to obtain an intermediate transfer body 3. The surface roughness Ra of the intermediate transfer member 3 was 30 nm.

(Intermediate transfer member 4)
An intermediate transfer member 4 was obtained in the same manner as the intermediate transfer member 3 except that the coat thickness of the varnish was changed to about 3 μm. The intermediate transfer member 4 had a surface roughness Ra of 50 nm.

(Intermediate transfer member 5)
An intermediate transfer member 5 was obtained in the same manner as the intermediate transfer member 3 except that the coat thickness of the varnish was changed to about 1 μm. The intermediate transfer member 5 had a surface roughness Ra of 100 nm.

(Intermediate transfer member 6)
An intermediate transfer member 6 was obtained in the same manner as the intermediate transfer member 3 except that the coat thickness of the varnish was changed to about 0.5 μm. The intermediate transfer member 6 had a surface roughness Ra of 120 nm.

2. Preparation of Metal Ink Composition 2-1. Preparation of metal nanoparticle dispersion (silver nanoparticle dispersion 1)
Into a 1 L separable flask having a flat stirring blade and baffle plate, 8.6 g of DISPERBYK-190 (manufactured by BYK Chemie) and 269 g of ion-exchanged water are added and stirred to dissolve DISPERBYK-190. I did. Subsequently, 55 g of silver nitrate dissolved in 269 g of ion exchange water was added to the separable flask while stirring. Furthermore, 70 g of ammonia water was added and stirred, and then the separable flask was placed in a water bath and heated and stirred until the temperature of the solution was stabilized at 80 ° C. Thereafter, 144 g of dimethylaminoethanol was added to the separable flask, and the mixture was further stirred for 6 hours while maintaining at 80 ° C. to obtain a reaction solution containing silver nanoparticles.

  The obtained reaction liquid was put into a stainless steel cup, and 2 L of ion exchange water was further added, and then the pump was operated to perform ultrafiltration. When the solution in the stainless cup decreased, ion-exchanged water was added again, and purification was repeated until the filtrate had a conductivity of 100 μS / cm or less. Thereafter, the filtrate was concentrated to obtain a silver nanoparticle dispersion 1 having a solid content of 30 wt%.

  The ultrafiltration apparatus used was an ultrafiltration module AHP1010 (Asahi Kasei Co., Ltd., Molecular weight cut off: 50000, number of membranes used: 400) connected with a tube pump (Masterflex Co., Ltd.) by a tygon tube. .

The obtained silver nanoparticle dispersion liquid 1 was observed by SEM, and the volume average particle diameter of the nanoparticles was determined. Specifically, it was carried out according to the following procedure.
1) After applying the dispersion on a glass plate, vacuum degassing was performed to volatilize the solvent component to obtain a sample. The obtained sample was subjected to SEM observation using JEOL JSM-7401F manufactured by JEOL Ltd., and the particle diameters of arbitrary 300 silver nanoparticles were measured.
2) Based on the obtained measurement data, the image processing software Image J was used to obtain a volume-based particle size distribution, and D50 (median diameter) was defined as an average particle diameter (volume average particle diameter) in terms of volume.
According to the result of the above measurement, the average particle size of the silver nanoparticle dispersion 1 was 20 nm.

(Silver nanoparticle dispersion 2)
In the preparation of silver nanoparticle dispersion 1, silver nanoparticle dispersion 2 was prepared in the same manner as in silver nitrate dispersion, except that 70 g of the added amount of silver nitrate, 7.6 g of the dispersant, 89 g of ammonia water, and 183 g of dimethylaminoethanol were changed. Obtained.
The average particle diameter of the silver nanoparticle dispersion liquid 2 was determined in the same manner as the silver nanoparticle dispersion liquid 1 above. As a result, the average particle size was 50 nm.

(Silver nanoparticle dispersion 3)
The silver nanoparticle dispersion 3 was prepared in the same manner as in the preparation of the silver nanoparticle dispersion 1, except that the amount of silver nitrate added was 83 g, the dispersant was 8.3 g, the amount of aqueous ammonia was 71 g, and the amount of dimethylaminoethanol was 217 g. Obtained.
The average particle diameter of the silver nanoparticle dispersion liquid 3 was determined in the same manner as the silver nanoparticle dispersion liquid 1 above. As a result, the average particle size was 80 nm.

(Gold nanoparticle dispersion 1)
The gold nanoparticles used were commercially available particle dispersions (Sigma- Aldrich, Gold nanoparticles).
The average particle size of the gold nanoparticles was 50 nm.

2-2. Preparation of emulsion resin particle dispersion (emulsion resin particle dispersion 1)
In a flask equipped with a dehydrator, 10 parts by mass of terephthalic acid as an acid component, 190 parts by mass of isophthalic acid and 170 parts by mass of adipic acid, 32 parts by mass of ethylene glycol as a glycol component, and 510 parts by mass of neopentyl glycol And 0.2 part by mass of tetraisopropyl titanate as a reaction catalyst was added, and then a condensation reaction was carried out at 220 ° C. until an acid value of 1.0 or less and a water content of 0.05% or less was obtained to obtain polyester glycol 1 .

  In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen blowing pipe, 488 parts by mass of polyester glycol 1 obtained above, 13 parts by mass of trimethylolpropane, and 88 parts by mass of dimethylol propionic acid 252 parts by mass of isophorone diisocyanate and 670 parts by mass of methyl ethyl ketone were added and reacted at 75 ° C. for 4 hours to obtain a methyl ethyl ketone solution of a urethane prepolymer. This solution was cooled to 40 ° C. and neutralized by adding 40 parts by mass of triethylamine. Thereafter, 1850 parts by mass of ion-exchanged water was gradually added, emulsified and dispersed using a homogenizer, and stirred for 1 hour. The solvent was removed at 50 ° C. under reduced pressure, and ion exchange water was further added to obtain an emulsion resin particle dispersion 1 made of polyurethane having a nonvolatile content of about 20%. It was 40 nm when the average particle diameter of the obtained emulsion resin particle was measured similarly to the said silver nanoparticle dispersion liquid 1.

3. Preparation of Metal Ink Composition (Metal Ink Composition 1)
Metal ink composition 1 was prepared by mixing with the following composition.
Silver nanoparticle dispersion liquid 1 5 parts by mass Emulsion resin particle dispersion liquid 1 0.35 parts by mass Water 59.2 parts by mass Propylene glycol 10 parts by mass Triethylene glycol monomethyl ether 25.4 parts by mass Surfactant (BYK-348: Big Chemie 0.1 parts by mass

(Metal ink composition 2)
In preparing the metal ink composition 1, a metal ink composition 2 was prepared in the same manner except that the silver nanoparticle dispersion 2 was used instead of the silver nanoparticle dispersion 1.

(Metal ink composition 3)
In preparing the metal ink composition 1, the metal ink composition 3 was prepared in the same manner except that the silver nanoparticle dispersion liquid 3 was used instead of the silver nanoparticle dispersion liquid 1.

(Metal ink composition 4)
A metal ink composition 4 was prepared in the same manner except that the gold nanoparticle dispersion 1 was used in place of the silver nanoparticle dispersion 1 in the preparation of the metal ink composition 1.

(Metal ink composition 5)
In the preparation of the metal ink composition 1, the metal nanoparticle-containing ink 5 was prepared in the same manner except that the composition ratio of the silver nanoparticle dispersion 1 was changed to 50 parts by mass.

4. Preparation of adhesion layer composition 4-1. Preparation of Monomer Liquid Mixture 1 567 parts by mass of styrene, 165 parts by mass of n-butyl acrylate, 68 parts by mass of methacrylic acid, and 4 parts by mass of n-octylmercaptan are mixed, and these are mixed with “monomer mixture 1” did.

4-2. Preparation of Monomer Liquid Mixture 2 390 parts by mass of styrene, 40 parts by mass of methacrylic acid, and 13 parts by mass of n-octylmercaptan were mixed to obtain “monomer mixed liquid 2”.

4-3. Formation of Core 4 parts by mass of polyoxyethylene = sodium dodecyl ether sulfate and 3000 parts by mass of ion exchanged water are charged into a reaction vessel equipped with a stirring device, a temperature sensor, a cooling pipe and a nitrogen introducing device, and 230 rpm under nitrogen stream The temperature was raised to 80 ° C. while stirring at a stirring speed of.
After the temperature rise, an initiator solution in which 8 parts by mass of potassium persulfate (KPS) is dissolved in 200 parts by mass of ion-exchanged water is added, and the liquid temperature is brought to 75 ° C. The solution was added dropwise over 1 hour. After the dropping, the polymerization reaction was carried out by heating and stirring at 75 ° C. for 2 hours to prepare a dispersion liquid of “Core 1”.

4-4. Formation of Shell Layer 40 parts by mass (solid content conversion value) of the dispersion of the “core 1” in a reaction vessel equipped with a stirring device, temperature sensor, cooling pipe, and nitrogen introducing device, polyoxyethylene = sodium dodecyl ether sulfate 2 Part by mass and 1270 parts by mass of ion-exchanged water were added, and the temperature was heated to 80 ° C.
After heating, an initiator solution in which 10 parts by mass of potassium persulfate (KPS) was dissolved in 200 parts by mass of ion exchanged water was added to the dispersion. Thereafter, the liquid temperature was set to 80 ° C., and the “monomer mixed liquid 2” was added dropwise over 1 hour. The mixture was further heated and stirred at 80 ° C. for 2 hours to carry out a polymerization reaction, and then cooled to 28 ° C. to obtain a dispersion of core-shell type latex resin particles (A2).

4-5. Preparation of Adhesion Layer Composition The adhesion layer composition was prepared by mixing 58 parts by mass of the dispersion of the core-shell latex resin particles (A2) described above, 10 parts by mass of glycerin, 10 parts by mass of diethylene glycol, and 22 parts by mass of ion exchanged water. A product was prepared.

5. Preparation of Protective Layer Composition The following composition was mixed to prepare a protective layer composition.
Binder resin (polyester resin emulsion, manufactured by Toyobo Co., Ltd., trade name: Vylonal MD1500, solid content 30%) 25.0 parts by mass Water 46.9 parts by mass Propylene glycol 7.9 parts by mass Triethylene glycol monomethyl ether 20. 1 part by mass Surfactant (BYK-348: manufactured by Big Chemie) 0.1 part by mass

Examples 1-15, Comparative Examples 1-3
Glossy images were formed using the intermediate transfer members 1 to 5, the metal ink compositions 1 to 5, the adhesion layer composition, and the protective layer composition prepared above.

(1) Substrate A gloss image was formed on the following substrate.
Coated paper: Oji Paper Co., Ltd. OK top coat +
Fine paper: Nippon Paper Industries npi fine
Art paper: made by Oji Paper Co., Ltd. OK Kim Fuji +

(2) Image formation conditions The inkjet recording apparatus had an intermediate transfer member, an ink tank, an ink supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head. As the intermediate transfer member, any one of the intermediate transfer members 1 to 5 produced above was used. The inkjet head is driven under the conditions of a droplet amount of 14 pl, a printing speed of 0.5 m / sec, an ejection frequency of 10.5 kHz, and a printing rate of 100%, and ejects a droplet of the metal ink composition onto the intermediate transfer member. The ink was allowed to land to form a glossy layer.

  When the image had a protective layer, the protective layer was formed on the intermediate transfer member using the protective layer composition described above under the same ink jet recording apparatus and conditions as described above before forming the glossy layer. Then, a gloss layer was formed on the protective layer using the metal ink composition under the above-described conditions.

Next, using an ink jet recording apparatus having the same piezo type ink jet nozzle, an adhesive layer having a thickness shown in Table 1 was formed on the gloss layer using the adhesive layer composition. The film thickness of the adhesion layer was adjusted by the amount of discharged droplets of ink jet.
After landing, it was dried with an infrared drying lamp for 3 seconds to form a laminated coating film.

  The resulting laminated coating film was transferred onto each substrate to obtain a glossy image.

Image formation by the screen method in Example 15 was performed as follows.
Optical images were formed in the same manner as in Examples 1 to 14 except that the gloss layer was formed by silk screen printing (mesh # 200).

  Moreover, in the case of image formation by the inkjet method which does not use an intermediate transfer body in Comparative Examples 1 and 2, an image was directly formed on a substrate using an inkjet recording apparatus having a piezoelectric inkjet nozzle. The inkjet recording apparatus includes an ink tank, an ink supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezoelectric inkjet head in this order from the upstream side to the downstream side through which ink flows. . The ink jet head is driven under the conditions of a droplet amount of 14 pl, a printing speed of 0.5 m / sec, an ejection frequency of 10.5 kHz, and a printing rate of 100%, and directly ejects droplets of the metal ink composition onto the substrate. And landed.

7). Evaluation Images were evaluated according to the following criteria.

7-1. Reflectance For the image-formed product formed by the above method, the reflectance at each wavelength of 10 nm is measured in the range of 450 nm to 650 nm using a spectrophotometer U4100, and the average value thereof is determined. evaluated.
(Evaluation criteria)
:: The above average value is 50% or more. :: The above average value is less than 50% 40% or more. Δ: The above average value is less than 40% 30% or more. ×: The above average value is less than 30%. did.

7-2. Weathering Resistance The following sulfur exposure test was performed on the obtained image-formed product to evaluate sulfuration resistance (weathering resistance).
That is, a petri dish containing sulfur powder was placed in a sealable glass bottle. Then, the obtained image-formed product was placed at a position 10 cm away from the petri dish containing sulfur powder, and the container was sealed. The vessel was then heated at 80 ° C. for 19 hours to expose the image former under a sulfur vapor atmosphere. Thereafter, the image formed product was taken out from the glass bottle, and the change in reflectance in the visible light region was measured.
Then, L *, a *, and b * were calculated from the reflectance, and the color difference ΔE * was calculated by applying to the following equation.
ΔE * = [(ΔL *) 2+ (Δa *) 2+ (Δb *) 2] 1/2
And it evaluated on the following references | standards.
(Evaluation criteria)
◎: ΔE * is less than 3 ○: ΔE * is 3 or more and less than 5 △: ΔE * is 5 or more and less than 10 ×: ΔE * is 10 or more The greater the value of the color difference ΔE *, the greater the change in reflectance and color. , Means that the sulfidation of silver nanoparticles in the metallic gloss layer is in progress.
○ It was judged that the above was practical.

  The evaluation results are shown in Table 1.

  As is apparent from Table 1, a glossy image is formed with a metal ink composition containing metal nanoparticles by an image forming method using an intermediate transfer body having an ink application region having a surface roughness Ra of 5 nm to 100 nm. In Examples 1 to 15 which were conducted, images having high reflectance, that is, high glossiness could be formed regardless of the type of the substrate. On the other hand, in the same image forming method of Comparative Example 3 as Example 1 except that the surface roughness of the intermediate transfer member exceeded 100 nm, an image having a sufficient reflectance could not be formed.

  Furthermore, when Examples 1-3 which are the same except the particle size of a metal nanoparticle are compared, it turns out that the particle size of a metal nanoparticle is optimal at about 50 nm. If the particle size of the metal nanoparticles is about 50 nm, the dispersibility of the metal nanoparticles is good, so the occurrence of nanoparticle aggregation is small, the surface roughness of the glossy layer due to the aggregates, It is thought that it is easy to achieve a high reflectance because the deterioration of the property is very difficult to occur. In addition, if the particle size of the metal nanoparticles is about 50 nm, the possibility that the surface roughness of the gloss layer will increase is low as it causes a decrease in reflectance.

  Comparing Examples 4 to 6 which are the same except for the thickness of the adhesion layer, it is possible to form an image having a very good reflectance when the thickness of the adhesion layer is 10 μm to 50 μm (Example 5). I understand. When the film thickness of the adhesion layer is 10 μm or more, the effect of causing the transfer layer to follow the unevenness of the substrate is high, and it is considered that the reflectance is increased. However, if the film thickness of the adhesion layer exceeds 50 μm (Example 6), leveling defects at the time of coating tend to occur, the film thickness of the adhesion layer becomes uneven, and the reflectance may decrease. It is believed that there is.

  An image excellent in reflectance and weather resistance could be formed not only when the glossy ink composition containing silver nanoparticles was used but also when the glossy ink composition containing gold nanoparticles (Example 13) was used. .

  In addition, the gloss images of Examples 7, 9, 11 and 12 provided with a protective layer had improved weather resistance compared to the gloss images of other examples having no protective layer.

  In addition, as long as the gloss layer forming means uses an intermediate transfer body, an image with high reflectance can be formed by either the inkjet method (Examples 1 to 14) or the screen method (Example 15). It was. However, comparing Examples 14 and 15 which are the same except that the means for forming the glossy layer is different, in Example 14 using the ink jet method, an image having a higher reflectance than Example 15 using the screen method is obtained. Could be formed. On the other hand, in Comparative Examples 1 and 2 in which the gloss image was formed directly on the substrate surface by the inkjet method not using an intermediate transfer member, it was not possible to achieve sufficient reflectance.

  When the gloss image forming method and the gloss image forming apparatus of the present invention are used, a gloss image having excellent gloss can be formed. Therefore, the present invention is expected to expand the range of application of the recorded matter having the luminosity, and to contribute to the development and spread of the technology in the field.

DESCRIPTION OF SYMBOLS 100 gloss image forming apparatus 105 intermediate transfer member 110 protective layer forming unit 112 supply roller 114 thermal transfer roller 116 release roller 118 collecting roller 120 metal glossy layer forming unit 122 ink tank 124 ink supply piping 126 ink supply tank 128 ink jet head 130 adhesive layer Forming unit 132 Ink tank 134 Ink supply piping 136 Ink supply tank 138 Ink jet head 140 Drying unit 150 Transfer unit 152 Pressure roller 200 Conveyance path

Claims (8)

Forming a metallic gloss layer by applying a metal ink composition containing metal nanoparticles to an ink application region provided on the surface of the intermediate transfer member and having a surface roughness Ra of 5 nm or more and 100 nm or less;
A step of providing an adhesion layer composition containing a resin component on the opposite side of the metallic gloss layer from the intermediate transfer body to form an adhesion layer;
Adhering the adhesion layer and the base material, and transferring the adhesion layer and the metallic luster layer to the surface of the base material;
A method for forming a glossy image.   The glossy image forming method according to claim 1, wherein the metal nanoparticles are particles having an average particle diameter of 10 nm to 80 nm.   The glossy image forming method according to claim 1, wherein the adhesion layer is a layer having a thickness of 10 μm to 50 μm. Before the step of forming the metallic gloss layer, the step of applying a protective layer composition to the ink application region of the intermediate transfer body to form a protective layer,
The step of forming the metallic gloss layer is a step of forming the metallic gloss layer on the ink application area where the protective layer is formed,
The method for forming a glossy image according to any one of claims 1 to 3, wherein the adhesion step is a step of transferring the protective layer, the metallic gloss layer, and the adhesion layer to a substrate.   The method for forming a glossy image according to any one of claims 1 to 4, wherein the metal ink composition is applied to the ink application region of the surface of the intermediate transfer body by an inkjet method. An intermediate transfer member having on the surface thereof an ink application region having a surface roughness Ra of 5 nm or more and 100 nm or less;
A metallic gloss layer forming portion for applying a metallic ink composition containing metallic nanoparticles to the ink application region to form a metallic gloss layer;
An adhesion layer forming part that forms an adhesion layer by applying an adhesion layer composition containing a resin component to the opposite side of the intermediate transfer body of the metallic gloss layer;
A substrate transport unit for transporting a substrate to which the metallic gloss layer and the adhesion layer are transferred from the intermediate transfer member;
A transfer part for bringing the adhesion layer and the substrate into close contact with each other, and transferring the adhesion layer and the metallic luster layer to the surface of the substrate;
A glossy image forming apparatus having:   The protective layer forming unit that forms a protective layer by applying a protective layer composition to the ink application region on the surface of the intermediate transfer body before the metallic gloss layer forming unit forms the metallic gloss layer. 7. The glossy image forming apparatus according to 6.   The gloss image forming apparatus according to claim 6, wherein the metal gloss layer forming unit applies the metal ink composition to the ink application area of the surface of the intermediate transfer member by an inkjet method.

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