JP7359658B2 - Inkjet print manufacturing method and image forming method - Google Patents

Description

The present invention relates to a method for producing an inkjet print and an image forming method. More specifically, the present invention relates to a method for producing an inkjet print and an image forming method, which are capable of producing an inkjet print that suppresses bleeding at the interface between the respective inks and has a glossy appearance.

Conventionally, techniques have been developed for forming an inkjet image on a substrate using ultraviolet curable ink to produce printed matter. Patent Document 1 proposes a technique in which a UV-curable ink is applied to a three-dimensional medium, and landed ink droplets are irradiated with ultraviolet rays to temporarily cure the ink to maintain the dot shape of the ink.

By the way, printed matter in which the base material is painted in two or more different colors has been developed. For such prints, the first color of paint is usually applied to the base material, dried and cured, and then a part or all of the area to which the first color of paint was applied is masked, and then the second color of paint is applied. It can be produced by applying a paint and drying (curing) it again.

JP2006-327142A

The inkjet printer described in Patent Document 1 is characterized in that temporary curing is performed immediately after the ink lands so that the dot shape of the ink droplets does not collapse, thereby preventing the ink from flowing and causing the dot shape to collapse. In this case, since the ink droplets retain their dot shape through temporary curing, the formed image has a grainy surface and poor gloss. Therefore, it is difficult for the inkjet printer described in Patent Document 1 to produce a glossy inkjet image.

By the way, when using paint to paint a base material in two or more different colors, as mentioned above, a drying (curing) process is required each time one color of paint is applied, or the second and subsequent colors are applied. Since a masking step is required each time before printing, the manufacturing process is complicated and the production efficiency of printed products is low. Therefore, it is possible to use an inkjet method to apply two or more colors in one painting process. However, in this case, bleeding may occur at the interface where the applied inks come into contact.

The present invention has been made to solve these problems, and uses an inkjet method to apply two or more different colors of ink in a single painting process, thereby simplifying the manufacturing process. An object of the present invention is to provide a method for manufacturing an inkjet print and an image forming method, which can suppress bleeding at the interface between the respective inks and produce an inkjet print that has a glossy appearance.

When applying a plurality of inks using an inkjet method, the inventors have developed a method that allows each ink to be applied by separating the areas to which each ink is applied, and by temporarily curing the ink after each ink is applied. By making the ink flow after temporary curing, the shape of the ink droplets is purposely flattened, and the ink droplets are bonded together to form a film, which improves the resulting inkjet image. The present invention was completed by focusing on the ability to impart gloss. The method for manufacturing an inkjet print and the method for forming an image according to the present invention that solves the above problems mainly include the following configurations.

(1) An inkjet process of applying a first ink and a second ink onto a substrate by an inkjet method; and a temporary curing process of temporarily curing the applied first ink and second ink. , a main curing step of further curing the applied first ink and second ink, wherein the base material has a first region and a second region different from the first region. and a third region between the first region and the second region, and the inkjet step includes applying the first ink to the first region and applying the first ink to the second region. It is a step of applying the second ink to a region, and the temporary curing step reduces the fluidity of the first ink and the second ink, and also reduces the fluidity of the first ink and the second ink. A method for manufacturing an inkjet print, the step of causing at least one of the first region and the second region to flow so as to protrude from at least one of the first region and the second region to cover the third region.

According to such a configuration, at least one of the first ink and the second ink is cured to the extent that it flows appropriately in the temporary curing step. As a result, the ink flows, the shape of the ink droplets becomes flat, and the ink droplets combine to form a film. Thereby, the resulting print can be given gloss. In addition, after the flowing ink flows so as to cover the third region, the inks come into contact with each other. At this time, each ink is temporarily hardened to the extent that it flows appropriately, so it is difficult to mix. As a result, the resulting print is less likely to bleed at the interface. The resulting print may be coated with two or more different colors of ink using an inkjet method. Therefore, the present method for producing a printed product can simplify the production process compared to a conventional method in which masking and drying steps are performed using paint.

(2) The base material has an inclined surface inclined at a predetermined angle with respect to the horizontal direction, and at least a part of the first region is formed at a position above the second region on the inclined surface. In the temporary curing step, the fluidity of the first ink and the second ink is reduced to cause the first ink to flow beyond the first region, and the third ink is The method for producing an inkjet print according to (1), which is a step of covering the area.

According to such a configuration, in the temporary curing step, at least a portion of the other ink (the first ink) is higher than one of the inks (the second ink) among the inks applied to the inclined surface. When applied to a location, such other ink (first ink) flows appropriately and covers the third area before contacting the second ink. As a result, the printed matter obtained is less likely to bleed at the boundary surface even on an inclined surface.

(3) The base material has a horizontal surface formed in a substantially horizontal direction, and the temporary curing step is performed by reducing the fluidity of the first ink and the second ink. a step of flowing ink and the second ink so as to protrude from the first region and the second region, and covering the third region with the first ink and the second ink, (1) The method for producing an inkjet print as described.

According to such a configuration, in the temporary curing step, both inks applied to the horizontal surface flow appropriately and cover the third region. As a result, the printed matter obtained is less likely to bleed at the boundary surface even on the horizontal plane.

(4) an inkjet step of applying a first ink and a second ink onto a substrate by an inkjet method; and a temporary curing step of temporarily curing the applied first ink and second ink. , a main curing step of further curing the applied first ink and second ink, wherein the base material has a first region and a second region different from the first region. and a third region between the first region and the second region, and the inkjet step includes applying the first ink to the first region and applying the first ink to the second region. It is a step of applying the second ink to a region, and the temporary curing step reduces the fluidity of the first ink and the second ink, and also reduces the fluidity of the first ink and the second ink. An image forming method comprising the step of causing at least one of the first region and the second region to flow so as to protrude from at least one of the first region and the second region to cover the third region.

According to such a configuration, at least one of the first ink and the second ink loses some fluidity in the temporary curing step compared to before the temporary curing, but is not completely cured. As a result, the ink can flow even after temporary hardening, the shape of the ink droplets becomes flat, and the ink droplets combine to form a film. Thereby, the obtained inkjet image can be given gloss. In addition, after the flowing ink flows so as to cover the third region, the inks come into contact with each other. At this time, each ink is temporarily hardened to the extent that it flows appropriately, so it is difficult to mix. As a result, the resulting inkjet image is less likely to bleed at the interface. The resulting inkjet image may be coated with two or more different colors of ink depending on the inkjet method. Therefore, this image forming method can form an image in a simpler manner than the conventional method of painting a base material in two or more different colors using paints.

According to the present invention, since two or more different colors of ink can be applied using an inkjet method, the manufacturing process can be simplified, bleeding at the interface between each ink can be suppressed, and glossiness can be improved. It is possible to provide a method for manufacturing an inkjet print and an image forming method that can produce an inkjet print with the applied inkjet print.

FIG. 1A is a schematic cross-sectional view for explaining one embodiment of the present invention. FIG. 1B is a schematic plan view for explaining one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view for explaining one embodiment of the present invention. FIG. 3A is a schematic cross-sectional view for explaining one embodiment of the present invention. FIG. 3B is a schematic plan view for explaining one embodiment of the present invention. FIG. 4A is a schematic cross-sectional view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 4B is a schematic plan view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 5A is a schematic cross-sectional view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 5B is a schematic plan view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 6A is a schematic cross-sectional view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 6B is a schematic plan view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 7A is a schematic cross-sectional view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 7B is a schematic plan view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 8A is a schematic cross-sectional view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 8B is a schematic plan view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 9A is a schematic cross-sectional view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 9B is a schematic plan view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 10A is a schematic cross-sectional view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 10B is a schematic plan view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 11A is a schematic cross-sectional view for explaining a method of manufacturing a printed matter using a conventional paint. FIG. 11B is a schematic plan view for explaining a method of manufacturing a printed matter using a conventional paint.

<Print manufacturing method and image forming method>
A method for manufacturing a printed product according to an embodiment of the present invention includes an inkjet step of applying a first ink and a second ink onto a base material by an inkjet method, and an inkjet step of applying a first ink and a second ink onto a base material, The method includes a temporary curing step of temporarily curing the ink, and a main curing step of further curing the applied first ink and second ink. The base material has a first region, a second region different from the first region, and a third region between the first region and the second region. The inkjet process is a process of applying a first ink to a first area and applying a second ink to a second area. The temporary curing step reduces the fluidity of the first ink and the second ink, and at least one of the first ink and the second ink is added to the first region and the second region. This is a step of causing the fluid to flow so as to protrude from at least one side to cover the third region. Further, the image forming method of one embodiment of the present invention includes an inkjet step of applying a first ink and a second ink onto a base material by an inkjet method, and an inkjet step of applying a first ink and a second ink onto a base material, The method includes a temporary curing step of temporarily curing the ink, and a main curing step of further curing the applied first ink and second ink. The base material has a first region, a second region different from the first region, and a third region between the first region and the second region. The inkjet process is a process of applying a first ink to a first area and applying a second ink to a second area. The temporary curing step reduces the fluidity of the first ink and the second ink, and at least one of the first ink and the second ink is added to the first region and the second region. This is a step of causing the fluid to flow so as to protrude from at least one side to cover the third region.

According to the printed matter manufacturing method and image forming method of the present embodiment (hereinafter collectively referred to as the present embodiment), at least one of the first ink and the second ink is used in the temporary curing step. , cured to the extent that it is moderately fluid. As a result, the ink flows, the shape of the ink droplets becomes flat, and the ink droplets combine to form a film. Thereby, the resulting print can be given gloss. In addition, after the flowing ink flows so as to cover the third region, the inks come into contact with each other. At this time, each ink is temporarily hardened to the extent that it flows appropriately, so it is difficult to mix. As a result, the resulting print is less likely to bleed at the interface. The resulting print may be coated with two or more different colors of ink using an inkjet method. Therefore, in this embodiment, the manufacturing process can be simplified compared to a method of painting a base material in two or more different colors using conventional paints. Each configuration will be explained below. Note that, in order to simplify the explanation, this embodiment will exemplify a case where two types of ink (a first ink and a second ink) are used. This embodiment is the same even when three or more types of ink are used.

(Inkjet process)
The inkjet process is a process of applying a first ink and a second ink onto a base material using an inkjet method.

The method of applying the first ink and the second ink to the base material by an inkjet method is not particularly limited. These methods include continuous methods such as charge modulation method, microdot method, charged jetting control method, ink mist method, and on/off methods such as piezo method, pulse jet method, bubble jet (registered trademark) method, and electrostatic suction method. An example is a demand method.

The inkjet device that discharges ink using an inkjet method is not particularly limited. Inkjet devices include serial type inkjet devices and line type inkjet devices, as well as inkjet devices that have a head mounted on the tip of a robot arm, or inkjet devices that have a serial mechanism on the tip of a robot arm. good.

In this embodiment, each nozzle for applying the first ink and the second ink, and each means (for example, an ultraviolet irradiation lamp (UV irradiation lamp)) for performing temporary curing and main curing described below are both , can be provided at any position of the inkjet device.

The base material to which the first ink and the second ink are applied is not particularly limited. For example, the base material is a metal plate such as a steel plate, aluminum or stainless steel, a plastic plate or film such as acrylic, polycarbonate, ABS, polypropylene, polyester, or vinyl chloride, a ceramic plate, concrete, wood, glass, etc. These substrates are preferably treated with a pretreatment agent before printing. Examples of the pretreatment agent include fluorine-based paints, silicone-based paints, acrylic silicone-based paints, acrylic-based paints, epoxy-based paints, and urethane-based paints. Examples of methods for applying these pretreatment agents to the substrate include a spray method, a roll coater method, a curtain flow coater method, a brush coating method, a spatula coating method, a dipping method, and an inkjet method. Moreover, the base material of this embodiment may have various designs (for example, silver-based or pearl-based designs) expressed by applying paint to the surface.

The base material has a region (first region) to which a first ink described below is applied and a region (second region) to which a second ink is applied. The first region and the second region are regions provided at arbitrary positions on the base material, and the regions do not overlap with each other. Further, the base material has a third region between the first region and the second region, to which the first ink and the second ink are not applied. At least one of the first ink and the second ink flows into the third region from at least one of the first region and the second region in a temporary curing step to be described later. This is the area covered by any ink.

- First Ink The first ink is preferably a UV-curable inkjet ink because it can be applied to various base materials and is easy to dry (cure). A UV curable inkjet ink contains a reactive monomer or a reactive oligomer and a photopolymerization initiator.

The first ink contains a dye, a pigment, a binder resin, a dispersant, a solvent, and various optional components as necessary. Optional components include, for example, heat stabilizers, antioxidants, preservatives, antifoaming agents, penetrants, reduction inhibitors, leveling agents, pH adjusters, polymerization inhibitors, ultraviolet absorbers, and light stabilizers. These can be selected as appropriate.

- Reactive monomer The reactive monomer is not particularly limited. For example, reactive monomers include hexafunctional acrylates such as dipentaerythritol hexaacrylate and modified products thereof; pentafunctional acrylates such as dipentaerythritol hydroxypentaacrylate; pentaditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, etc. Tetrafunctional acrylates; trifunctional acrylates such as trimethylolpropane triacrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, glyceryl triacrylate; hydroxypivalic acid neopentyl glycol diacrylate, polytetramethylene glycol Diacrylate, trimethylolpropane acrylic acid benzoate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate Acrylate, neopentyl glycol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, dimethylol-tricyclodecanedi acrylate, bifunctional acrylates such as bisphenol A diacrylate; and caprolactone acrylate, tridecyl acrylate, isodecyl acrylate, isooctyl acrylate, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl-diglycol diacrylate, 2-hydroxybutyl Acrylate, 2-acryloyloxyethyl hexahydrophthalic acid, neopentylfuricol acrylic acid benzoate, isoamyl acrylate, lauryl acrylate, stearyl acrylate, butoxyethyl acrylate, ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, methoxy- Polyethylene glycol acrylate, methoxydipropylene glycol acrylate, phenoxyethyl acrylate, phenoxy-polyethylene glycol acrylate, nonylphenol acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3 - phenoxypropyl acrylate, 2-acryloyloxyethyl-succinic acid, 2-acryloyloxyethyl-phthalic acid, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid, and other monofunctional acrylates. Reactive monomers may be used in combination.

When a reactive monomer is blended, the content of the reactive monomer is not particularly limited. For example, the content of the reactive monomer is preferably 50 parts by mass or more based on 100 parts by mass of the ink. Further, the content of the reactive monomer is preferably 85 parts by mass or less per 100 parts by mass of the ink. When the content of the reactive monomer is within the above range, the viscosity of the ink can be easily adjusted, and ejection failure is less likely to occur during inkjet printing. The ink also tends to be properly cured.

- Reactive oligomer The reactive oligomer is not particularly limited. For example, reactive oligomers include urethane acrylate, polyester acrylate, epoxy acrylate, silicone acrylate, polybutadiene acrylate, and the like. Reactive oligomers may be used in combination.

The weight average molecular weight (Mw) of the reactive oligomer is not particularly limited. For example, the Mw of the reactive oligomer is preferably 1000 or more. Further, the Mw of the reactive oligomer is preferably 50,000 or less. In this specification, the Mw of the reactive oligomer is a value measured by, for example, GPC (gel permeation chromatography), and is measured using a high-speed GPC device (manufactured by Tosoh Corporation, HLC-8120GPC). obtain.

When a reactive oligomer is blended, the content of the reactive oligomer is not particularly limited. For example, the content of the reactive oligomer is preferably 1 part by mass or more, more preferably 5 parts by mass or more, per 100 parts by mass of the ink. Further, the content of the reactive oligomer is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, per 100 parts by mass of the ink. When the content of the reactive oligomer is within the above range, the inkjet layer of the resulting printed product tends to exhibit excellent toughness, flexibility, and adhesion.

- Photopolymerization initiator The photopolymerization initiator is not particularly limited. For example, photopolymerization initiators include benzoins, benzyl ketals, aminoketones, titanocenes, bisimidazoles, hydroxyketones, and acylphosphine oxides. A photopolymerization initiator may be used in combination.

When a photopolymerization initiator is blended, the content of the photopolymerization initiator is not particularly limited. For example, the content of the photopolymerization initiator is preferably 1 part by mass or more, more preferably 3 parts by mass or more, based on 100 parts by mass of the ink. Further, the content of the photopolymerization initiator is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the ink. When the content of the photopolymerization initiator is within the above range, polymerization tends to proceed.

- Binder resin A binder resin is preferably included in order to, for example, adjust the viscosity of the ink, adjust the hardness of the obtained print, and control the shape.

The type of binder resin is not particularly limited. For example, binder resins include fluororesin, epoxy resin, diallyl phthalate resin, silicone resin, phenol resin, unsaturated polyester resin, polyimide resin, polyurethane resin, melamine resin, urea resin, ionomer resin, ethylene ethyl acrylate resin, Acrylonitrile acrylate styrene copolymer resin, acrylonitrile styrene resin, acrylonitrile chloride polyethylene styrene copolymer resin, ethylene vinyl acetate resin, ethylene vinyl alcohol copolymer resin, acrylonitrile butadiene styrene copolymer resin, vinyl chloride resin, chlorinated polyethylene resin, polyvinylidene chloride Resin, cellulose acetate resin, polyoxymethylene resin, polyamide resin, polyarylate resin, thermoplastic polyurethane elastomer, polyetheretherketone resin, polyethersulfone resin, polyethylene, polypropylene, polycarbonate resin, polystyrene, polystyrene maleic acid copolymer resin, Polystyrene acrylic acid copolymer resin, polyphenylene ether resin, polyphenylene sulfide resin, polybutadiene resin, polybutylene terephthalate resin, acrylic resin, methylpentene resin, polylactic acid, polybutylene succinate resin, butyral resin, formal resin, polyvinyl alcohol, polyvinyl pyrrolidone , ethyl cellulose, carboxymethyl cellulose, gelatin, and copolymer resins thereof. The binder resin may be appropriately selected in consideration of film strength, viscosity, residual viscosity of the inkjet ink, dispersion stability of coloring material, thermal stability, non-coloring property, water resistance, and chemical resistance. A binder resin may be used in combination.

The content of binder resin is not particularly limited. For example, the binder resin preferably accounts for 1% by mass or more, more preferably 3% by mass or more, in the ink in terms of solid content. Further, the binder resin preferably accounts for 40% by mass or less, more preferably 30% by mass or less, in the ink in terms of solid content.

- Dispersant A dispersant is suitably included in order to disperse the above-mentioned pigment. The dispersant is not particularly limited. For example, the dispersant may be an anionic surfactant, a nonionic surfactant, a polymer dispersant, or the like. A dispersant may be used in combination.

When a dispersant is included in the ink, the content of the dispersant is appropriately determined depending on the type and content of the pigment to be dispersed. For example, the content of the dispersant is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, based on 100 parts by mass of the pigment. Further, the content of the dispersant is preferably 150 parts by mass or less, more preferably 80 parts by mass or less, based on 100 parts by mass of the pigment.

-Solvent A solvent is preferably included in the ink to dissolve the reactive oligomer and binder resin. The type of solvent is not particularly limited. Examples of the solvent include water, glycol ether solvents, acetate solvents, alcohol solvents, ketone solvents, ester solvents, hydrocarbon solvents, fatty acid ester solvents, aromatic solvents, and the like. Solvents may be used in combination. Among these, the solvent of the present embodiment preferably contains at least one of a glycol ether solvent and an acetate solvent. Glycol ether solvents and acetate solvents both have low viscosity and relatively high boiling points. Therefore, inks containing these as solvents have improved drying properties and better ejection stability during inkjet printing.

Returning to the description of the first ink as a whole, the viscosity of the first ink is not particularly limited. For example, the viscosity of the first ink is preferably 2 mPa·s or more, more preferably 5 mPa·s or more. Further, the viscosity of the first ink is preferably 50 mPa·s or less, more preferably 30 mPa·s or less. When the viscosity of the first ink is within the above range, the first ink is less likely to cause ejection failure from the inkjet head and has excellent ejection stability. In the present embodiment, the viscosity of the first ink can be measured using a B-type viscometer (manufactured by Toki Sangyo Co., Ltd., TVB-20LT, rotor rotation speed 60 rpm). Note that the method for adjusting the viscosity within the above range is not particularly limited. For example, the viscosity can be adjusted by the amount of each component added and the type and amount of the solvent. The viscosity may be adjusted by using a viscosity modifier such as a thickener, if necessary.

The surface tension of the first ink is not particularly limited. The surface tension of the first ink is preferably 20 dyne/cm or more, more preferably 22 dyne/cm or more at 25°C. Further, the surface tension of the first ink is preferably 40 dyne/cm or less, more preferably 35 dyne/cm or less at 25°C. When the surface tension is within the above range, the first ink has excellent ejection stability. In this embodiment, the surface tension can be measured using a static surface tension meter (plate method) (manufactured by Kyowa Interface Science Co., Ltd., CBVP-A3).

-Second Ink The second ink is similar to the first ink except that it exhibits a different hue from the first ink. That is, the second ink may contain a different dye or pigment than the first ink, thereby exhibiting a different hue, and may contain the same dye or pigment as the first ink in a different content. may exhibit different hues.

Further, it is preferable that the second ink does not mix with the first ink when it comes into contact with the first ink in the temporary curing step described below. Therefore, it is preferable that the viscosity difference and surface tension difference between the first ink and the second ink be as small as possible so that the first ink and the second ink are difficult to mix with each other.

Returning to the explanation of the inkjet process, the first ink and the second ink may be applied to the base material simultaneously by an inkjet device. Note that in the present embodiment, "applying at the same time" does not strictly require applying the first ink and the second ink "at the same time." In other words, the present embodiment uses ink of two or more different colors, compared to a conventional coating method in which a masking process and a drying process (main curing process in this embodiment) are provided between each coating process using a paint. It is characterized by being able to give. Therefore, for example, even if the first color ink (first ink) is applied and the first color ink is not temporarily ejected, the second color ink can be applied without performing the masking process or the main curing process. If ink (second ink) is applied, it is included in "simultaneously applying" in this embodiment. These can be adjusted as appropriate depending on the difference in area between the first region to which the first ink is applied and the second region to which the second ink is applied.

At the time the inkjet process is performed, the first ink has been applied to the first region of the substrate, and the second ink has been applied to the second region of the substrate. A third region to which the first ink and the second ink are not applied is formed between the first region and the second region. Further, at this point, the first ink and the second ink have not been cured. Therefore, the first ink and the second ink exhibit predetermined fluidity. In the subsequent temporary curing step, the first ink and the second ink are cured to such an extent that their fluidity is lost to some extent.

(temporary curing process)
The temporary curing step is a step of temporarily curing the applied first ink and second ink.

According to the temporary curing step, the fluidity of the first ink and the second ink decreases. As a result, at least one of the first ink and the second ink flows to protrude from at least one of the first region and the second region, and covers the third region.

When the third region is covered with at least one of the first ink and the second ink, the first ink and the second ink contact each other. At this time, since both the first ink and the second ink have been temporarily cured, their fluidity has been somewhat lost compared to before temporary curing. As a result, the first ink and the second ink are less likely to mix with each other and are less likely to bleed at the interface. The first ink and the second ink are further cured in the subsequent main curing step.

In this embodiment, the type of ink that covers the third region is not particularly limited. The third region may be covered by only one (for example, the first ink), or may be covered by both the first ink and the second ink.

- When the third area is covered with only one of the inks, for example, the base material has an inclined surface (which may be a curved surface) inclined at a predetermined angle with respect to the horizontal direction, and the third area is covered with only one of the inks. If at least a part of the region is formed above the second region on the inclined surface, the temporary curing step reduces the fluidity of the first ink and the second ink. The ink may flow beyond the first region to cover the third region. That is, on the inclined surface, a region (first region) to which one ink (for example, the first ink) is applied is a region (second region) to which the other ink (for example, the second ink) is applied. may be formed in a higher position than the In this case, the first ink flows downward from the first region and covers the third region. On the other hand, since the second ink is applied to the second region located below the first ink, it is difficult to flow to cover the third region. As a result, in the base material having such an inclined surface, the third region is covered with only one ink (the first ink). In this case, both the first ink and the second ink have been temporarily cured, and therefore have lost some fluidity compared to before being temporarily cured. As a result, even if the first ink flows and covers the third area and then comes into contact with the second ink, the first ink and the second ink are difficult to mix with each other, and the boundary Does not easily cause bleeding on surfaces. Therefore, the resulting print is less likely to bleed at the boundary surface even on an inclined surface.

- When the third area is covered by both inks On the other hand, for example, when the base material has a horizontal surface formed in a substantially horizontal direction, the temporary curing step is performed by covering the first ink and the second ink. By reducing the fluidity of the first ink and the second ink, the first ink and the second ink are made to flow beyond the first region and the second region, and the third ink is The area may be covered. That is, in the horizontal plane, not only the first ink but also the second ink flows. As a result, the third region formed between the first region and the second region is covered with both inks. In this case, both the first ink and the second ink have been temporarily cured, and therefore have lost some fluidity compared to before being temporarily cured. As a result, even if the first ink and the second ink flow and cover the third area and then come into contact with each other, the first ink and the second ink are difficult to mix with each other. Less likely to cause bleeding at the interface. Therefore, the obtained printed matter is less likely to bleed at the boundary surface even on the horizontal plane.

As described above, according to the present embodiment, regardless of the shape of the base material (whether it has an inclined surface or a horizontal surface, etc.), one or both of the inks can be made to flow as appropriate to form the third region. It is possible to form a covered, bleed-free interface. Therefore, this embodiment can be applied not only to planar substrates but also to three-dimensional substrates (molded bodies) having various surface shapes, and in such substrates, the boundary surface without bleeding can be can be formed.

Note that the width of the third region (the distance between the first region and the second region) is not particularly limited. The width of the third region can be adjusted as appropriate based on the type, physical properties, etc. of the flowing ink. For example, when ink is applied to the above-mentioned inclined surface, only the first ink flows to cover the third region. On the other hand, when ink is applied to a horizontal surface, both the first ink and the second ink flow to cover the third area. Therefore, the width of the third region on the inclined surface may be adjusted to be somewhat narrower than the width of the third region on the horizontal surface. Thereby, even if only the first ink flows, the third region is likely to be sufficiently covered.

The width of the third region is preferably 0.1 to 2 mm, more preferably 0.5 to 1.5 mm. By setting the width of the third region within the above range, a clearer boundary surface is likely to be formed.

The conditions for temporary curing in the temporary curing step are not particularly limited. The ink applied to the base material is temporarily cured by being irradiated with ultraviolet rays by a UV irradiation lamp attached to an inkjet device. Examples of UV irradiation lamps include mercury lamps, gas/solid lasers, and the like. Among these, the UV irradiation lamp is preferably a mercury lamp or a metal halide lamp. Further, the UV irradiation lamp may be an ultraviolet light emitting diode (UV-LED) or an ultraviolet laser diode (UV-LD).

The cumulative amount of ultraviolet rays during temporary curing is not particularly limited as long as it can temporarily cure the ink droplets to such an extent that they have appropriate fluidity. The integrated light amount is preferably 10 mJ/cm ² or more, more preferably 30 mJ/cm ² or more. Further, the cumulative light amount is preferably 500 mJ/cm ² or less, more preferably 300 mJ/cm ² or less. Note that the integrated light amount can be measured using, for example, an ultraviolet illuminance meter/light meter (UVPF-A2 manufactured by Eye Graphics Co., Ltd.) under the conditions of a measurement wavelength range of 365 nm. When the cumulative amount of light is within the above range, the first ink and the second ink have appropriate fluidity and can be temporarily cured to the extent that they do not mix when they come into contact with each other.

In this embodiment, the temporary curing process may be performed after the inkjet process as a process different from the inkjet process, or may be performed in parallel with the inkjet process.

When a temporary curing process is performed in parallel with the inkjet process, the temporary curing UV irradiation lamp used in the temporary curing process may be provided so as to follow the head of the inkjet device, or may be provided so as not to follow the head of the inkjet device. Good too. When provided so as to follow the head, the temporary curing UV irradiation lamp follows the head and sequentially temporarily cures droplets of inkjet ink applied to the base material. On the other hand, when the temporary curing UV irradiation lamp is provided so as not to follow the head, the temporary curing UV irradiation lamp appropriately sequentially temporarily cures the inkjet ink droplets applied to the base material, independently of the operation of the head.

- Main curing step The main curing step is a step of further curing the applied and temporarily hardened first ink and second ink. In the above-described temporary curing step, at least one of the first ink and the second ink flows to protrude from at least one of the first region and the second region, and flows into the third region. covered. By further curing (main curing) in this state, an inkjet image covering the third area is formed.

The conditions for main curing in the main curing step are not particularly limited. The ink applied to the base material is irradiated with ultraviolet rays by a UV irradiation lamp attached to an inkjet device, and is fully cured. Examples of UV irradiation lamps include mercury lamps, gas/solid lasers, and the like. Among these, the UV irradiation lamp is preferably a mercury lamp or a metal halide lamp. Further, the UV irradiation lamp may be an ultraviolet light emitting diode (UV-LED) or an ultraviolet laser diode (UV-LD).

The cumulative amount of ultraviolet light during main curing is not particularly limited. The integrated light amount is preferably 500 mJ/cm ² or more, more preferably 800 mJ/cm ² or more. Further, the integrated light amount is preferably 5000 mJ/cm ² or less, more preferably 3000 mJ/cm ² or less. Note that the integrated light amount can be measured using, for example, an ultraviolet illuminance meter/light meter (UVPF-A2 manufactured by Eye Graphics Co., Ltd.) under the conditions of a measurement wavelength range of 365 nm. When the cumulative amount of light is within the above range, the first ink and the second ink can be sufficiently cured.

It is preferable that the main curing step is performed after a predetermined standby time has elapsed from the temporary curing step. That is, in the temporary curing step, the fluidity of the first ink and the second ink is reduced, and at least one of the first ink and the second ink further flows to cover the third region. The main curing step is preferably performed after the third region is covered. Thereby, the inks can be fully cured so that the third region is sufficiently covered and the inks are not further mixed at the interface where they are in contact with each other.

The waiting time from the completion of the temporary curing process to the actual curing process is not particularly limited. The waiting time can be adjusted as appropriate depending on the degree of fluidity exhibited by the ink whose fluidity has been reduced by the temporary curing step, the width of the third region, the angle of the base material, and the like. For example, the waiting time is about 10 to 300 seconds.

Further, the temporary curing step and the main curing step may be performed continuously. In addition, in the temporary curing process, the curing conditions (for example, the cumulative amount of ultraviolet light) gradually become stricter depending on the extent to which the first ink or the second ink flows and covers the third area. It may be adjusted accordingly. This makes it possible to make the ink flow quickly at the beginning of the temporary curing process, and to tighten the curing conditions so that the fluidity of the ink is further reduced at the end of the temporary curing process. The curing performed after the inks come into contact with each other may be referred to as a main curing step. Thereby, in this embodiment, the time required for the temporary curing process can be shortened, and production efficiency can be further improved.

As described above, according to the present embodiment, at least one of the first ink and the second ink is cured to the extent that it flows appropriately in the temporary curing step. As a result, the ink flows and the shape of the ink droplet becomes flat. Thereby, the resulting print can be given gloss. In addition, after the flowing ink flows so as to cover the third region, the inks come into contact with each other. At this time, each ink is temporarily hardened to the extent that it flows appropriately, so it is difficult to mix. As a result, the resulting print is less likely to bleed at the interface. The resulting print may be coated with two or more different colors of ink using an inkjet method. Therefore, according to the present embodiment, the manufacturing process can be simplified compared to a method in which masking and drying steps are performed using a conventional paint.

As a result, this embodiment is suitable for various applications that require coloring in two or more different hues. For example, according to the present embodiment, a base material such as a metal plate such as a steel plate, aluminum, or stainless steel, a plastic plate or film such as acrylic, polycarbonate, ABS, polypropylene, polyester, or vinyl chloride, a ceramic plate, concrete, wood, or glass, etc. It is suitable for various applications using. These substrates may be treated by pre-treatment before printing. Examples of the pretreatment agent include fluorine-based paints, silicone-based paints, acrylic silicone-based paints, acrylic-based paints, epoxy-based paints, and urethane-based paints. Examples of methods for applying these pretreatment agents to the substrate include a spray method, a roll coater method, a curtain flow coater method, a brush coating method, a spatula coating method, a dipping method, and an inkjet method. Further, the base material may have various designs (for example, silver-based or pearl-based designs) expressed by applying paint to the surface.

Here, the printed matter obtained by this embodiment is less likely to cause bleeding on the boundary surface, and the design (inkjet image) obtained is clearer compared to the method of painting the base material in two or more colors using conventional paint. This point will be explained with reference to the drawings.

1A to 3B are schematic cross-sectional views for explaining this embodiment. FIG. 1A shows the state after the inkjet process (cross-sectional view), FIG. 1B shows the state after the inkjet process (plan view), FIG. 2 shows the state after the temporary curing process, and FIG. 3A shows the state after the main curing process. FIG. 3B shows the state after the main curing step (plan view).

As shown in FIGS. 1A and 1B, the first ink 1 is applied to the first region R1 of the base material 3 in the inkjet process. On the other hand, the second ink 2 is applied to the second region R2 of the base material 3. Note that the area to which the first ink 1 and the second ink 2 are not applied in the inkjet process is the third area R3.

In the inkjet process, both the first ink 1 and the second ink 2 have some fluidity. Therefore, in the subsequent temporary curing step, temporary curing is performed such that the fluidity of the first ink 1 and the second ink 2 is somewhat reduced.

As shown in FIG. 2, in the temporary curing step, the first ink 1 and the second ink 2 are temporarily hardened. In FIG. 2, an embodiment in which ultraviolet light A1 is irradiated is illustrated as a temporary curing means.

The fluidity of the first ink 1 and the second ink 2 irradiated with ultraviolet light A1 is somewhat reduced. However, the first ink 1 and the second ink 2 after temporary curing are not completely cured and have fluidity, although the fluidity is reduced compared to before temporary curing. Therefore, the first ink 1 and the second ink 2 both flow to cover the third region R3 and come into contact with each other. Arrow A2 indicates the direction of ink flow. The first ink 1 and the second ink 2 in contact have somewhat reduced fluidity and therefore are difficult to mix with each other. Further, due to the flow, the shapes of the first ink and second ink droplets are flattened, and the ink droplets are combined with each other to form a film. Thereby, the glossiness of the resulting print can be improved.

As shown in FIGS. 3A and 3B, in the main curing step, the first ink 1 and the second ink 2 are main cured. In FIG. 3A and FIG. 3B, an embodiment in which ultraviolet light A1 is irradiated is illustrated as a means for main curing.

The first ink 1 and the second ink 2 are cured to form an inkjet image on the substrate 3. As shown in FIGS. 3A and 3B, the cured first ink 1 and second ink 2 are unlikely to overlap near the interface. As a result, the resulting inkjet image has clear boundaries and is less likely to bleed. In addition, the obtained inkjet image does not have a coating level difference due to masking, which is seen in conventional images formed using masking processing. As a result, the resulting image has smooth color boundaries.

Next, a method of painting a base material in two or more colors using conventional paints will be explained. FIGS. 4A to 7B are a schematic cross-sectional view and a plan view for explaining a method of manufacturing a printed matter using a conventional paint. 4A shows a state (cross-sectional view) in which the first color paint 4 is applied to the base material 3, and FIG. 4B shows a state (top view) in which the first color paint 4 is applied to the base material 3. 5A shows a state (cross-sectional view) in which masking 6 is applied after drying the first color paint 4, and FIG. 5B shows a state (plan view) in which masking 6 is applied after drying the first color paint 4, FIG. 6A shows a state (cross-sectional view) in which the second color paint 5 is applied to the base material 3, and FIG. 6B shows a state (plan view) in which the second color paint 5 is applied to the base material 3, 7A shows a state (cross-sectional view) with the masking 6 removed, and FIG. 7B shows a state (plan view) with the masking 6 removed.

As shown in FIGS. 4A and 4B, for example, when the first color paint 4 is applied to the substrate 3 by spraying, the amount of paint applied is not uniform at the edges of the applied surface in many cases, and some A region with a small amount (region 4a) is formed. The applied first color paint 4 is then dried. In FIGS. 4A and 4B, an embodiment in which heat A3 is applied as a drying means is illustrated. As described above, the conventional method using paint requires a step of drying the first color paint 4 before applying the second color paint 5.

As shown in FIGS. 5A and 5B, the dried first color paint 4 is masked 6 so as not to be overcoated when the second color paint 5 is applied. At this time, the masking 6 is not applied to areas where the first color paint 4 is not uniformly applied (area 4a, see FIG. 4A). Such a region 4a is overcoated with the second color paint 5. Further, in this way, the conventional method using paint requires masking 6 on the first color paint 4 before applying the second color paint 5.

As shown in FIGS. 6A and 6B, the second color paint 5 is applied. The applied second color paint 5 is then dried. In FIGS. 6A and 6B, an embodiment in which heat A3 is applied as a drying means is illustrated. As described above, the method using the conventional paint requires a second drying step for drying the second color paint 5 after applying the second color paint 5.

As shown in FIGS. 7A and 7B, when the masking 6 is removed, a printed product with a design is produced.

Here, as shown in FIGS. 7A and 7B, in the region R4, the first color paint 4 and the second color paint 5 are mixed. In such a region R4, for example, when the second color paint 5 has excellent light transmittance, or when the first color paint 4 is dark, the hues of each other influence each other, and two different colors A mixed border is formed. As a result, in the conventional method of painting the base material 3 in two or more colors, it is difficult to form clear boundary lines. Further, the conventional method requires a plurality of drying steps, requires masking 6 as an additional step, and has a complicated manufacturing process compared to the present embodiment.

Further, FIGS. 8A to 11B are a schematic cross-sectional view and a plan view for explaining a method of manufacturing a printed matter using a conventional paint, which is different from the above. 8A shows a state (cross-sectional view) in which the first color paint 4 is applied to the entire surface of the base material 3, and FIG. 8B shows a state (cross-sectional view) in which the first color paint 4 is applied to the entire surface of the base material 3 ( 9A shows a state (cross-sectional view) in which masking 6 is applied after drying the first color paint 4, and FIG. 9B shows a state (top view) in which masking 6 is applied after drying the first color paint 4. ), FIG. 10A shows a state (cross-sectional view) in which the second color paint 5 is applied to the entire surface, FIG. 10B shows a state (plan view) in which the second color paint 5 is applied to the entire surface, and FIG. 11A shows the state in which the second color paint 5 is applied to the entire surface. 11B shows a state (top view) with masking 6 removed. FIG. 11B shows a state (plan view) with masking 6 removed.

As shown in FIGS. 8A and 8B, the first color paint 4 is applied to the entire surface of the base material 3. As shown in FIGS. The applied first color paint 4 is then dried. In FIGS. 8A and 8B, an embodiment is illustrated in which heat A3 is applied as the drying means. As described above, the conventional method using paint requires a step of drying the first color paint 4 before applying the second color paint 5.

As shown in FIGS. 9A and 9B, the dried first color paint 4 is applied to the area that should be left as the first color so that when applying the second color paint 5, areas other than the desired area are not overcoated. Masking 6 is applied. As described above, the method using the conventional paint requires masking 6 on the first color paint 4 before applying the second color paint 5.

As shown in FIGS. 10A and 10B, the second color paint 5 is applied to the entire area where the masking 6 has been applied and the first paint 4 has been applied. The applied second color paint 5 is then dried. In FIGS. 10A and 10B, an embodiment in which heat A3 is applied as a drying means is illustrated. As described above, the method using the conventional paint requires a second drying step for drying the second color paint 5 after applying the second color paint 5.

As shown in FIGS. 11A and 11B, when the masking 6 is removed, a printed product with a design is produced.

Here, as shown in FIGS. 11A and 11B, in the area where the second color paint 5 is formed, the first color paint 4 is formed below it. Therefore, for example, if the second color paint 5 has excellent light transmittance or if the first color paint 4 is dark, the hue of the first color paint 4 will affect the hue of the second color paint 5. can affect Further, as shown in FIGS. 11A and 11B, a step corresponding to the thickness of the second color paint 5 is formed between the area where the second color paint 5 is formed and the area where the first color paint 4 is formed. can be done. Therefore, according to the conventional method of producing printed matter using paint, there is a risk that an image including undesired steps may be formed. Further, the first color paint 4 is applied to the entire surface including the area where the second color paint 5 is applied. Further, the second color paint 5 is applied to the entire surface including the masking 6, and then the portion corresponding to the masking 6 is removed. As a result, all of the conventional methods of producing printed matter using paints increase the cost required for painting. In addition, with the conventional method, it is difficult to remove only the masking 6 in the area corresponding to the first color paint 4 from the state shown in FIG. 10A. Therefore, in the state shown in FIG. 11A, by peeling off the masking 6, the surface coated with the second color paint 5 (particularly the surface that was in contact with the masking 6) is likely to be damaged.

In contrast, in this embodiment, inkjet inks of two or more colors can be applied simultaneously or consecutively, and when applying the inks of two or more colors, each ink is dried (cured) in separate steps. ) There is no need to do so. Further, additional steps such as masking processing are not required. Therefore, compared to the conventional method, the present embodiment not only can form a clearer design (inkjet image) especially at the boundary line, but also has a simpler manufacturing method and superior productivity.

Hereinafter, the present invention will be explained in more detail with reference to Examples. The present invention is not limited to these examples at all.

The raw materials used are shown below.
(Pigment dispersion Bk)
15 parts by mass of a black pigment (NIPEX35, manufactured by Orion Engineered Carbons Co., Ltd.), 10 parts by mass of a dispersant (solsperse 33000, manufactured by Nippon Lubrizol Co., Ltd.), and 75 parts by mass of IBXA (isobonyl acrylate, Pigment dispersion Bk was prepared by mixing and filtering the pigments (manufactured by Kyoeisha Kagaku Co., Ltd.) using a mixer.
(Pigment dispersion Y)
15 parts by mass of a yellow pigment (D1085J, manufactured by BASF Corporation), 7.5 parts by mass of a dispersant (solsperse 33000, manufactured by Nippon Lubrizol Co., Ltd.), and 77.5 parts by mass of IBXA (isobonyl acrylate, Pigment dispersion Y was prepared by mixing and filtering the pigments (manufactured by Kyoeisha Kagaku Co., Ltd.) using a mixer.
(reactive monomer)
SR420NS: 3,3,5-trimethylcyclohexanol acrylate, Arkema Co., Ltd. SR238F: Bifunctional acrylate monomer, 1,6-hexanediol diacrylate, Arkema Co., Ltd. FX-AO-MA: 2-(allyloxy) Methyl) methyl acrylate, manufactured by Nippon Shokubai Co., Ltd. (reactive oligomer)
CN991: Polyester urethane acrylate, manufactured by Arkema Co., Ltd. (photopolymerization initiator)
Irg184: 1-Hydroxycyclohexyl phenyl ketone, manufactured by BASF Irg819: Bis(2,4,6,-trimethylbenzoyl)-phenylphosphine oxide, manufactured by BASF (polymerization inhibitor)
UV10: Bis(2,2,6,6-tetramethyl-4-piperidyl-1-oxyl) sebacate, manufactured by BASF (leveling agent)
Megafac F-556: Oligomer containing fluorine-containing groups, hydrophilic groups, and lipophilic groups, manufactured by DIC Corporation

<Example 1>
Inkjet printing was performed on a horizontally placed steel plate base material under the following inkjet conditions to produce printed matter.

<Inkjet conditions>
Single pass method Dot size: 30pl
Nozzle diameter: 40μm
Drive voltage: 80V
Pulse width: 10μm
Frequency: 10kHz
Resolution: 400 x 800dpi
Coating amount: 15g/m ²
Base material temperature: 50℃ (warming)
Pattern: Two-color solid pattern of black and yellow (see Figure 3B)
Third area width: 1.0mm

<Temporary curing conditions>
After the inkjet process, temporary curing was performed under the following conditions.
Ultraviolet irradiation lamp: Metal halide lamp Irradiation intensity: 120mW/cm ²
Cumulative light amount: 60mJ/cm ²
Irradiation height: 40mm

<Main curing conditions>
After waiting for 180 seconds after the temporary curing step, main curing was performed under the following conditions.
Ultraviolet irradiation lamp: Metal halide lamp Irradiation intensity: 600mW/cm ²
Cumulative light amount: 1800mJ/cm ²
Irradiation height: 40mm

<Example 2>
A printed product of Example 2 was produced in the same manner as Example 1 except that the width of the third region was 0.5 mm.

<Example 3>
A printed product of Example 3 was produced in the same manner as Example 1 except that the width of the third region was 1.5 mm.

<Example 4>
A printed product in Example 4 was produced in the same manner as in Example 1, except that inkjet printing was performed on a steel plate base material fixed at an angle of 30 degrees from the horizontal. At this time, make sure that the area where the first ink is applied to make it black (first area) is above the area where the second ink is applied to make it yellow (second area). ink was applied. The first ink was flowed downward to cover the third region formed between the first region and the second region, thereby producing a print.

<Comparative example 1>
A printed product of Comparative Example 1 was produced in the same manner as in Example 1, except that the width of the third region was set to 0 mm (the third region was not provided and the first ink and the second ink were applied). .

<Comparative example 2>
Example 1 except that the width of the third region was 0 mm (the third region was not provided and the first ink and the second ink were applied), and the temporary curing step was not performed and the final curing was performed immediately after the inkjet step. A printed product of Comparative Example 2 was produced in the same manner.

The resulting prints were evaluated for image clarity and gloss according to the following evaluation criteria. The results are shown in Table 2.

<Image clarity of printed matter>
With respect to the obtained printed matter, the sharpness of the boundary surface was evaluated by visually confirming the boundary portion.
(Evaluation criteria)
○: The boundary was clearly formed.
×: The border was unclear, and a mixed color area was observed at the border.

<Glossiness of printed matter>
Using a gloss meter (handy gloss meter Gloss Checker IG-410, manufactured by Horiba, Ltd.), measurements were taken at 60 degrees for the black printed area and the yellow printed area for the obtained print. The glossiness was measured under the following conditions (incident angle: 60°, light receiving angle: 60°), and evaluated according to the following evaluation criteria. Note that the glossiness (blank) of the surface of the steel plate base material was 78.
(Evaluation criteria)
◎: Glossiness was 80 or more.
○: Glossiness was 50 or more and less than 80.
Δ: Glossiness was 20 or more and less than 50.
x: Glossiness was less than 20.

As shown in Table 2, according to the method for producing an inkjet print of the present invention, the boundaries between the black and yellow printed areas are clear, and each area has good gloss. showed that. On the other hand, according to the method for manufacturing an inkjet printed product of Comparative Example 1 in which the third area was not provided, the boundaries between the areas printed in black and yellow were unclear, and areas with mixed colors were observed. Furthermore, according to the method for manufacturing an inkjet printed product of Comparative Example 2 in which the temporary curing step was not adopted, the glossiness was low in each of the areas printed in black and yellow, and there was a grainy feel.

1 First ink 2 Second ink 3 Base material 4 First color paint 4a Region 5 Second color paint 6 Masking A1 Ultraviolet light A2 Flow direction of ink A3 Heat R1 First region R2 Second region R3 Third region Area R4 area

Claims (2)

an inkjet step of applying a first ink and a second ink onto a base material by an inkjet method;
a temporary curing step of temporarily curing the applied first ink and second ink;
a main curing step of further curing the applied first ink and the second ink,
The base material has a first region, a second region different from the first region, and a third region between the first region and the second region,
The base material has an inclined surface inclined at a predetermined angle with respect to the horizontal direction,
At least a portion of the first region is formed above the second region on the inclined surface,
The inkjet step is a step of applying the first ink to the first region and applying the second ink to the second region,
The temporary curing step lowers the fluidity of the first ink and the second ink to cause the first ink to flow beyond the first region, and to form the first ink in the third region. A method of manufacturing inkjet prints , which is a process of covering . an inkjet step of applying a first ink and a second ink onto a base material by an inkjet method;
a temporary curing step of temporarily curing the applied first ink and second ink;
a main curing step of further curing the applied first ink and the second ink,
The base material has a first region, a second region different from the first region, and a third region between the first region and the second region,
The base material has an inclined surface inclined at a predetermined angle with respect to the horizontal direction,
At least a portion of the first region is formed above the second region on the inclined surface,
The inkjet step is a step of applying the first ink to the first region and applying the second ink to the second region,
The temporary curing step lowers the fluidity of the first ink and the second ink to cause the first ink to flow beyond the first region, and to form the first ink in the third region. An image forming method that is a process of covering .

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