Inkjet recording method and inkjet recording apparatus

Abstract

To provide an inkjet recording method that uses a metallic ink composition and a colored ink composition to obtain a color metallic image with reduced color mixing of both compositions.SOLUTION: An inkjet recording method includes: a metallic ink adhesion step of ejecting a metallic ink composition containing a metallic pigment from an inkjet head and adhering it to a recording medium; a heating step of heating the metallic ink composition adhering to the recording medium by an infrared heater; and a colored ink adhesion step of ejecting a colored ink composition containing a coloring material from the inkjet head and adhering it to the metallic ink composition on the recording medium. The metallic ink composition and the colored ink composition are water-based ink or solvent-based ink.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an inkjet recording method and an inkjet recording apparatus. [Background technology]

[0002] An inkjet recording method is known in which minute ink droplets are ejected from nozzles of an inkjet head of an inkjet recording device to record an image on a recording medium. Inkjet recording methods have been actively developed, and attempts have been made to form glossy images using the inkjet recording method.

[0003] For example, Patent Document 1 discloses an inkjet recording method using metallic ink and color ink, and studies have been made to obtain images with improved aesthetics, such as forming a colored metallic gloss image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-256665 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the metallic ink composition and the colored ink composition are printed in an overlapping manner on a recording medium, there are cases in which the colors of the two inks are mixed together. [Means for solving the problem]

[0006] One aspect of the inkjet recording method according to the present invention comprises: a metallic ink deposition step of ejecting a metallic ink composition containing a metallic pigment from an inkjet head and depositing the ink on a recording medium; a heating step of heating the metallic ink composition attached to the recording medium by an infrared heater; a color ink depositing step of ejecting a color ink composition containing a coloring material from an inkjet head and depositing the color ink composition on the recording medium; Equipped with The metallic ink composition and the colored ink composition are water-based inks or solvent-based inks.

[0007] One aspect of the inkjet recording apparatus according to the present invention is to an inkjet head that ejects the metallic ink composition; Infrared heater, an inkjet head that ejects the above-mentioned colored ink composition; Equipped with Recording is carried out by the above-mentioned ink jet recording method. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view of an inkjet recording apparatus according to an embodiment. [Diagram 2] Schematic diagram of the cross section of an IR heater. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The following describes an embodiment of the present invention. The embodiment described below is an example of the present invention. The present invention is not limited to the following embodiments, and includes various modified forms that are implemented within the scope of the present invention. Note that not all of the configurations described below are essential configurations of the present invention.

[0010] 1. Inkjet recording method The inkjet recording method according to this embodiment includes a metallic ink applying step, a heating step, and a colored ink applying step.

[0011] 1.1.Metallic ink application process In the metallic ink applying step, a metallic ink composition containing a metallic pigment is ejected from an inkjet head to be applied to a recording medium.

[0012] 1.1.1.Metallic ink composition The metallic ink composition contains a metallic pigment.

[0013] (1) Metallic pigments The metallic pigment is not limited as long as it can form an image having metallic luster. The shape of the metallic pigment particles is not particularly limited, and may be, for example, tabular, spherical, columnar, etc. Among them, it is more preferable that the metallic pigment is a tabular particle in order to more efficiently express the metallic luster.

[0014] Here, the term "flat particle" refers to a particle having a substantially flat surface (XY plane) and a substantially uniform thickness (Z). Flat particles can be produced, for example, by crushing a metal deposition film, and can be obtained as metal particles having a substantially flat surface and a substantially uniform thickness. Therefore, the major axis of the flat particle on the plane can be defined as X, the minor axis as Y, and the thickness as Z.

[0015] The material of the metallic pigment may be various metals such as aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, copper, etc., or alloys thereof, etc., but aluminum or an aluminum alloy is preferable from the viewpoint of cost and ensuring excellent metallic luster. When an aluminum alloy is used, the metal element or nonmetal element to be alloyed is not particularly limited, but examples thereof include silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, copper, etc., and at least one of these simple substances, their alloys, and their mixtures is preferably used.

[0016] A method for producing a metallic pigment includes, for example, peeling a composite pigment base material having a structure in which a peelable resin layer and a metal or alloy layer are sequentially laminated on the surface of a sheet-like substrate at the interface between the metal or alloy layer and the peelable resin layer, and pulverizing and micronizing the composite pigment base material to obtain tabular particles. The metal or alloy layer is preferably formed by vacuum deposition, ion plating or sputtering.

[0017] The thickness of the metal or alloy layer is preferably, for example, 10 nm or more and 100 nm or less. More preferably, 20 nm or more and 100 nm or less. By setting it in the above range, the reflectivity and brilliance are excellent, and the performance as a metallic pigment is improved, and by setting it to 100 nm or less, the increase in apparent specific gravity can be suppressed and the dispersion stability of the metallic pigment can be improved. In addition, the average thickness of the metallic pigment, which is a plate-like particle, may be set in the above range. The average thickness is measured, for example, as follows. An ink containing the metallic pigment is diluted, the diluted liquid is applied to a substrate and dried, and the thickness of the dried metallic pigment is measured by AFM. Measurements are performed at 50 random points and the average value is calculated.

[0018] The volume average particle size of the metallic pigment is not particularly limited, but is preferably 0.30 μm or more and 1.00 μm or less. The volume average particle size is preferably 0.30 μm or less and 0.90 μm or less, more preferably 0.35 μm or more and 0.80 μm or less. The volume average particle size refers to the median diameter D50 of the volume distribution measured by using a laser diffraction / scattering method for a particle dispersion. When the volume average particle size is above the above range, the reflectivity and brilliance of the recorded material are superior, and when it is below the above range, the dispersion stability and ejection property are superior, which is preferable.

[0019] The peelable resin layer in the composite pigment base material is an undercoat layer for the metal or alloy layer, but is a peelable layer for improving the peelability from the sheet-like substrate surface. The resin used for this peelable resin layer is preferably, for example, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polyacrylic acid, polyacrylamide, cellulose derivatives, polyvinyl butyral, acrylic acid polymers, or modified nylon resins.

[0020] The peelable resin layer is applied by commonly used methods such as gravure coating, roll coating, blade coating, extrusion coating, dip coating, spin coating, etc. After coating and drying, the surface is smoothed by calendaring, if necessary.

[0021] Examples of the sheet-like substrate include, but are not limited to, polyester films such as polytetrafluoroethylene, polyethylene, polypropylene, and polyethylene terephthalate, polyamide films such as nylon 66 and nylon 6, polycarbonate films, triacetate films, and release films such as polyimide films. A preferred sheet-like substrate is polyethylene terephthalate or a copolymer thereof.

[0022] The metal or alloy layer may be sandwiched between protective layers, as exemplified in JP-A-2005-68250. Examples of the protective layer include a metal / alloy layer, a metal oxide layer, and an organic film layer. The metal / alloy layer is a layer of metal (including semi-metal) or alloy made of a material different from the metal or alloy of the pigment base. The metal oxide layer is a layer of oxide of metal (including semi-metal), and may be a film formed by natural oxidation of the metal or alloy of the pigment base. Examples include an alumina layer and a silicon oxide layer. It may also be a ceramic layer. The organic film layer may be, for example, a resin layer, and may be a resin layer in which the peeling resin layer remains as a protective resin layer, or may be a resin layer different from the peeling resin.

[0023] The silicon oxide layer, which is an example of the metal oxide layer, is not particularly limited as long as it is a layer containing silicon oxide, but is preferably formed from a silicon alkoxide such as tetraalkoxysilane or a polymer thereof by a sol-gel method. The silicon oxide layer can be formed, for example, by applying an alcohol solution in which a silicon alkoxide or a polymer thereof is dissolved, and then heating and baking the applied solution.

[0024] Furthermore, when a metal oxide film layer is to be formed, it can be formed, for example, by applying an alcohol solution in which a metal alkoxide or a polymer thereof is dissolved, and then heating and baking it.

[0025] The method for the peeling treatment from the sheet-like substrate is not particularly limited, but a method in which the composite pigment base material is immersed in a liquid, or a method in which the composite pigment base material is immersed in a liquid and simultaneously subjected to ultrasonic treatment, and the peeling treatment and the pulverization treatment of the peeled composite pigment are performed are preferred.

[0026] The tabular metallic pigment obtained as described above has a peelable resin layer that acts as a protective colloid, and a stable dispersion can be obtained simply by carrying out a dispersion treatment in a solvent.

[0027] When the metallic ink composition is a water-based composition, it is more preferable that the metallic pigment is surface-treated so that the metal is less likely to react with moisture and oxygen. Even when the metallic ink composition is a solvent-based composition, it is preferable that the metallic pigment is surface-treated so that the metal is less likely to react with oxygen and moisture. It is more preferable that the surface is treated so as to prevent the deterioration of the surface.

[0028] Here, "water-based ink" refers to an ink that contains at least water as the main solvent component among solvent inks that contain a solvent component that dissolves or disperses the solid components contained in the ink. Examples of the solvent include water and organic solvents. Water-based inks contain 20% by mass or more of water based on the total mass of the ink. The water content is more preferably 40% by mass or more, even more preferably 50% by mass or more, and particularly preferably 60% by mass or more.

[0029] Moreover, "solvent-based ink" refers to ink in which the main component of the solvent constituting the ink is an organic solvent. A solvent-based ink contains less than 20% by mass of water (does not contain more than 20% by mass) relative to the total mass of the ink. It is preferably 10% by mass or less, more preferably 1% by mass or less, and more preferably 0.1% by mass or less. Moreover, the content of the organic solvent relative to the total mass of the ink is preferably 10% by mass or more, more preferably 40% by mass or more, preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 80% by mass.

[0030] It is preferable that the metallic ink composition is not a UV ink (an ink used for recording that is cured by exposure to ultraviolet light or the like).

[0031] When the metallic pigment is subjected to a surface treatment, it is more preferable to perform the surface treatment with a fluorine compound or a silane compound. In this way, the metallic luster of the surface of the metallic pigment particles is better maintained, so that an image with better luster can be formed. In addition, when the surface treatment is performed, the base particles may or may not have the above-mentioned protective layer.

[0032] A specific example of the surface treatment method is to react a fluorine compound or a silane compound with the metallic pigment particles (base particles), for example by heating.

[0033] As such a fluorine compound, a compound containing fluorine and one or more selected from phosphorus, sulfur, and nitrogen as constituent elements can be preferably used, and specific examples include fluorine-based phosphonic acid, fluorine-based carboxylic acid, fluorine-based sulfonic acid, and salts thereof, etc. With these fluorine-based compounds, a phosphoric acid group, a carboxyl group, a sulfonic acid group, etc. can be bonded to the surface of the base particle to form a coating.

[0034] In addition, the fluorine compound has a perfluoroalkyl group (C n F2 n+1), and more preferably the number of carbon atoms in the perfluoroalkyl group is from 1 to 6. When the fluorine compound has such a structure, it is easy to obtain a metallic pigment having further excellent gloss and dispersibility, and the weather resistance tends to be better when an image is recorded.

[0035] Furthermore, the fluorine compound may contain silicon, and such a compound can be called a silicon-containing fluorine compound, but in this specification, it is treated as being included in the fluorine compound.

[0036] Examples of the fluorine compound include phosphorus-containing fluorine compounds, silicon-containing fluorine compounds, fluorine-containing fatty acids, fluorine-containing isocyanate compounds, etc. From the viewpoint of superior gloss, phosphorus-containing fluorine compounds and silicon-containing fluorine compounds are preferred.

[0037] The phosphorus-containing fluorine compound is a compound having a phosphorus-containing group and a fluorine-containing group. The fluorine-containing group may be a perfluoroalkyl structure described later. The phosphorus-containing group may be, for example, a phosphoric acid group, a phosphorous acid group, a phosphonic acid group, or a phosphinic acid group.

[0038] The silicon-containing fluorine compound is a compound having a silicon-containing group and a fluorine-containing group, which will be described later. The fluorine-containing group may be a perfluoroalkyl structure, which will be described later. The silicon-containing group may be an alkoxysilyl group. When the silicon-containing fluorine compound is used, it is easy to obtain a metallic pigment having excellent gloss and dispersibility, and the weather resistance tends to be better when an image is recorded.

[0039] Examples of silicon-containing fluorine compounds, for example, fluorine-containing compounds having a perfluoroalkyl structure, are not particularly limited, but include, for example, CF3-CH2CH2-Si(OCH3)3, CF3(CF2)3-CH2CH2-Si(OCH3)3, CF3(CF2)5-CH2CH2-Si(OCH3)3, CF3(CF2)5-CH2CH2-Si(OC2H5)3, CF3(CF2)7-CH2CH2-Si(OCH3)3, CF3(CF2)11 -CH2CH2-Si(OC2H5)3, CF3(CF2)3-CH2CH2-Si(CH3)(OCH3)2, CF3(CF2)7-CH2CH2-Si(CH3)(OCH3)2, CF3(CF2)8-CH2CH2-Si(CH3)(OC2H5)2, and CF3(CF2)8-CH2CH2-Si(C2H5)(OC2H5)2, and 1H,1H,2H,2H-perfluorodecyltriethoxysilane.

[0040] The above-mentioned perfluoroalkyl structure may be a perfluoroalkyl ether structure (C n F 2n+1 O) can also be used. Therefore, a fluorine compound having a perfluoroalkyl ether structure can also be used. The fluorine-containing silane compound having a perfluoroalkyl ether structure is not particularly limited, but examples thereof include CF3O(CF2O)6-CH2CH2-Si(OC2H5)3, CF3O(C3F6O)4-CH2CH2-Si(OCH3)3, CF3O(C3F6O)2(CF2O)3-CH2CH2-Si(OCH3)3, CF3O(C3F6O)8-CH2CH2-Si(OCH3)3, CF3O(C4F9O)5-CH2CH2-Si(OCH3)3, CF3O(C4F9O)5-CH2CH2-Si(CH3)(OC2H5)2, and CF3O(C3F6O)4-CH2CH2-Si(C2H5)(OCH3)2.

[0041] Examples of the phosphorus-containing fluorine compound include phosphorus-containing fluorine compounds having a perfluoroalkyl structure. Examples of the perfluoroalkyl structure include the perfluoroalkyl structures of the compounds described above or below. Examples of the phosphorus-containing fluorine compound include compounds represented by the general formula P(O)R n (OH) 3-n The compound represented by the formula (1) is an integer of 1 to 3. R is a perfluoroalkyl group (perfluoroalkyl structure). For example, 2-(perfluorohexyl)ethylphosphonic acid is mentioned.

[0042] Furthermore, the fluorine compound may be a fluorine-containing fatty acid, such as CF3-CH2CH2-COOH, CF3(CF2)3-CH2CH2-COOH, CF3(CF2)5-CH2CH2-COOH, CF3(CF2)6-CH2CH2-COOH, CF3(CF2)7-CH2CH2-COOH, and CF3(CF2)9-CH2CH2-COOH, or esters thereof.

[0043] Furthermore, the fluorine compound may be a fluorine-containing isocyanate compound having a chemical structure represented by the following formula (1), for example. R f NCO (1) Here, in formula (1), R f CF3(CF2) m - or CF3 (CF2) m (CH2) l where m is an integer between 2 and 18 inclusive, and l is an integer between 1 and 18 inclusive.

[0044] On the other hand, examples of silane compounds include tetramethoxysilane and tetraethoxysilane. , tetrapropoxysilane, tetrabutoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, trimethoxyphenylsilane, triethoxyphenylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and the like.

[0045] The skeleton of the silane compound is not particularly limited, and examples thereof include dimethyldimethoxysilane, diethyldiethoxysilane, 1-propenylmethyldichlorosilane, propyldimethylchlorosilane, propylmethyldichlorosilane, propyltrichlorosilane, propyltriethoxysilane, propyltrimethoxysilane, styrylethyltrimethoxysilane, tetradecyltrichlorosilane, 3-thiocyanatepropyltriethoxysilane, p-tolyldimethylchlorosilane, p-tolylmethyldichlorosilane, p-tolyltrichlorosilane, p-tolyltrimethoxysilane, p-tolyltriethoxysilane, di-n-propyldi-n-propoxysilane, diisopropyldiisopropoxysilane, di-n- butyldi-n-butyloxysilane, di-sec-butyldi-sec-butyloxysilane, di-t-butyldi-t-butyloxysilane, octadecyltrichlorosilane, octadecylmethyldiethoxysilane, octadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyldimethylchlorosilane, octadecylmethyldichlorosilane, octadecylmethoxydichlorosilane, 7-octenyldimethylchlorosilane, 7-octenyltrichlorosilane, 7-octenyltrimethoxysilane, octylmethyldichlorosilane, octyldimethylchlorosilane, octyltrichlorosilane, 10-undecenyldimethylchlorosilane, undecyltrichlorosilane, vinyldimethylchlorosilane, Methyldodecyldimethoxysilane, methyldodecyldiethoxysilane, methyloctadecyldimethoxysilane, methyloctadecyldiethoxysilane, n-octylmethyldimethoxysilane, n-octylmethyldiethoxysilane, triacontyldimethylchlorosilane, triacontyltrichlorosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltriisopropoxysilane, methyltri-n-butyloxysilane, methyltri- sec-butyloxysilane, methyltri-t-butyloxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-propoxysilane, ethyltriisopropoxysilane, ethyl-n-butyloxysilane, ethyltri-sec-butyloxysilane, ethyltri-t-butyloxysilane, n-propyltrimethoxysilane, isobutyltrimethoxysilane, n-hexyltrimethoxysilane, hexadecyltrimethoxysilane, n-octyltrimethoxysilane, n -Dodecyltriethoxysilane, n-octadecyltrimethoxysilane, n-propyltriethoxysilane, isobutyltriethoxysilane, n-hexyltriethoxysilane, hexadecyltriethoxysilane, n-octyltriethoxysilane, n-dodecyltrimethoxysilane, n-octadecyltriethoxysilane, 2-[2-(trichlorosilyl)ethyl]pyridine, 4-[2-(trichlorosilyl)ethyl]pyridine, diphenyldimethoxysilane, diphenyldiethoxysilane , 1,3-(trichlorosilylmethyl)heptacosane, dibenzyldimethoxysilane, dibenzyldiethoxysilane, phenyltrimethoxysilane, phenyltrimethyldimethoxysilane, phenyldimethylmethoxysilane, phenyldimethoxysilane, phenyldiethoxysilane, phenylmethyldiethoxysilane, phenyldimethylethoxysilane, benzyltriethoxysilane, benzyltrimethoxysilane, benzylmethyldimethoxysilane, benzyldimethylmethoxysilane, Benzyldimethoxysilane, benzyldiethoxysilane, benzylmethyldiethoxysilane, benzyldimethylethoxysilane, benzyltriethoxysilane, dibenzyldimethoxysilane, dibenzyldiethoxysilane, 3-acetoxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, 4-aminobutyltriethoxysilane, (aminoethylaminomethyl)phenethyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 6-(aminohexylaminopropyl)trimethoxysilane, p-aminophenyltrimethoxysilane, p-aminophenylethoxysilane, m-aminophenyltrimethoxysilane, m-aminophenylethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, ω-aminoundecyltrimethoxysilane, amyltriethoxysilane, benzoxasilepin dimethyl ester, 5-(bicycloheptenyl)triethoxysilane , bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, 8-bromooctyltrimethoxysilane, bromophenyltrimethoxysilane, 3-bromopropyltrimethoxysilane, n-butyltrimethoxysilane, 2-chloromethyltriethoxysilane, chloromethylmethyldiethoxysilane, chloromethylmethyldiisopropoxylane, p-(chloromethyl)phenyltrimethoxysilane, chloromethyltriethoxysilane, chlorophenyltriethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane, 2-cyanoethyltriethoxysilane, 2-cyanoethyltrimethoxysilane, cyanomethylphenethyltriethoxysilane, 3-cyanopropyltriethoxysilane, 2-(3-cyclohexenyl)ethyltrimethoxysilane, 2-(3-cyclohexenyl)ethyltriethoxysilane, 3-cyclohexenyltrichlorosilane, 2-(3-cyclohexenyl)ethyltrichlorosilane,2-(3-cyclohexenyl)ethyldimethylchlorosilane, 2-(3-cyclohexenyl)ethylmethyldichlorosilane, cyclohexyldimethylchlorosilane, cyclohexylethyldimethoxysilane, cyclohexylmethyldichlorosilane, cyclohexylmethyldimethoxysilane, (cyclohexylmethyl)trichlorosilane, cyclohexyltrichlorosilane, cyclohexyltrimethoxysilane, cyclooctyltrichlorosilane, (4-cyclooctenyl)trichlorosilane, cyclopentyltrichlorosilane, cyclopentyl ethyltrimethoxysilane, 1,1-diethoxy-1-silacyclopent-3-ene, 3-(2,4-dinitrophenylamino)propyltriethoxysilane, (dimethylchlorosilyl)methyl-7,7-dimethylnorpinane, (cyclohexylaminomethyl)methyldiethoxysilane, (3-cyclopentadienylpropyl)triethoxysilane, N,N-diethyl-3-aminopropyl)trimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxy Silane, (furfuryloxymethyl)triethoxysilane, 2-hydroxy-4-(3-triethoxypropoxy)diphenyl ketone, 3-(p-methoxyphenyl)propylmethyldichlorosilane, 3-(p-methoxyphenyl)propyltrichlorosilane, p-(methylphenethyl)methyldichlorosilane, p-(methylphenethyl)trichlorosilane, p-(methylphenethyl)dimethylchlorosilane, 3-morpholinopropyltrimethoxysilane, (3-glycidoxypropyl)methyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, Trimethoxysilane, 1,2,3,4,7,7,-hexachloro-6-methyldiethoxysilyl-2-norbornene, 1,2,3,4,7,7,-hexachloro-6-triethoxysilyl-2-norbornene, 3-iodopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, (mercaptomethyl)methyldiethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane,3-Methacryloxypropyltrimethoxysilane, Methyl {2-(3-trimethoxysilylp, propylamino)ethylamino}-3-propionate, 7-octenyltrimethoxysilane, RN-α-phenethyl-N'-triethoxysilylpropylurea, SN-α-phenethyl-N'-triethoxysilylpropylurea, phenethyltrimethoxysilane, phenethylmethyldimethoxysilane, phenethyldimethylmethoxysilane, phenethyldimethoxysilane, phenethyldiethoxysilane, phenethylmethyldiethoxysilane, phenethyldimethylethoxysilane, phenethyl Iethoxysilane, (3-phenylpropyl)dimethylchlorosilane, (3-phenylpropyl)methyldichlorosilane, N-phenylaminopropyltrimethoxysilane, N-(triethoxysilylpropyl)dansylamide, N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole, 2-(triethoxysilylethyl)-5-(chloroacetoxy)bicycloheptane, (S)-N-triethoxysilylpropyl-O-menthocarbamate, 3-(triethoxysilylpropyl) p-nitrobenzamide, 3-(triethoxysilyl)propyl succinic anhydride, N-[5-(trimethoxysilyl)-2-aza-1-oxo-pentyl]caprolactam, 2-(trimethoxysilylethyl)pyridine, N-(trimethoxysilylethyl)benzyl-N,N,N-trimethylammonium chloride, phenylvinyldiethoxysilane, 3-thiocyanatopropyltriethoxysilane, N-{3-(triethoxysilyl)propyl}phthalamic acid, 1-trimethyl N-(3-trimethoxysilylpropyl)pyrrole, N-trimethoxysilylpropyl-N,N,N-tributylammonium bromide, N-trimethoxysilylpropyl-N,N,N-tributylammonium chloride, N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride, vinylmethyldiethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyldimethylethoxysilane, vinylmethyldichlorosilane, vinylphenyldichlorosilane, vinylphenyldiethoxysilane, vinylphenyldimethylsilane, vinylphenylmethylchlorosilane, vinyltriphenoxysilane, vinyltris-t-butoxysilane, adamantylethyltrichlorosilane, allylphenyltrichlorosilane, (aminoethylaminomethyl)phenethyltrimethoxysilane, 3-aminophenoxydimethylvinylsilane, phenyltrichlorosilane, phenyldimethylchlorosilane, phenylmethyldichlorosilane, benzyltrichlorosilane, benzyldimethyl chlorosilane, benzylmethyldichlorosilane, phenethyldiisopropylchlorosilane, phenethyltrichlorosilane, phenethyldimethylchlorosilane, phenethylmethyldichlorosilane, 5-(bicycloheptenyl)trichlorosilane, 5-(bicycloheptenyl)triethoxysilane, 2-(bicycloheptyl)dimethylchlorosilane, 2-(bicycloheptyl)trichlorosilane, 1,4-bis(trimethoxysilylethyl)benzene, bromophenyltrichlorosilane, 3-phenoxypropyldimethylchlorosilane, 3-phenoxypropyltrichlorosilane, t-butylphenylchlorosilane, t-butylphenylmethoxysilane, t-butylphenyldichlorosilane, p-(t-butyl)phenethyldimethylchlorosilane, p-(t-butyl)phenethyltrichlorosilane, 1,Examples of the silane include 3-(chlorodimethylsilylmethyl)heptacosane, ((chloromethyl)phenylethyl)dimethylchlorosilane, ((chloromethyl)phenylethyl)methyldichlorosilane, ((chloromethyl)phenylethyl)trichlorosilane, ((chloromethyl)phenylethyl)trimethoxysilane, chlorophenyltrichlorosilane, 2-cyanoethyltrichlorosilane, 2-cyanoethylmethyldichlorosilane, 3-cyanopropylmethyldiethoxysilane, 3-cyanopropylmethyldichlorosilane, 3-cyanopropylmethyldichlorosilane, 3-cyanopropyldimethylethoxysilane, 3-cyanopropylmethyldichlorosilane, and 3-cyanopropyltrichlorosilane.

[0046] By surface-treating the base particles with such a fluorine compound or silane compound, a coating can be formed, and an image with good gloss can be formed. Note that two or more of the above fluorine compounds and silane compounds may be selected for the surface treatment.

[0047] The concentration of the metallic pigment in the metallic ink composition is from 0.1% by mass to 10.0% by mass, more preferably from 0.5% by mass to 8.0% by mass, and even more preferably from 1.0% by mass to 5.0% by mass.

[0048] (2) Other ingredients The metallic ink composition may contain the following components in addition to the metallic pigment.

[0049] (water) The metallic ink composition may contain water, whether it is a solvent-based ink or a solvent-based ink. As the water, it is preferable to use pure water or ultrapure water such as ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, etc. In particular, water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is preferable because it can suppress the growth of mold and bacteria for a long period of time.

[0050] (Organic solvent) The metallic ink composition may contain a solvent. The solvent is not particularly limited, but may be, for example, a glycol ether-based solvent. Examples of the glycol ether-based solvent include a compound represented by the following general formula (2). R 1 O-(R 2 O) m -R 3 (2) (In formula (2), R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R 2 is an alkylene group having 2 to 4 carbon atoms, R 3 is a hydrogen atom, an acetyl group, or an alkyl group having 1 to 6 carbon atoms. 1 and R 3 At least one of the groups is an alkyl group having 1 to 6 carbon atoms. m is an integer of 1 to 7.

[0051] Specific examples of the compound represented by the above general formula (2) include glycol monoethers such as methyl glycol, methyl diglycol, methyl triglycol, isopropyl glycol, isopropyl diglycol, butyl glycol, butyl diglycol, butyl triglycol, isobutyl glycol, isobutyl diglycol, hexyl glycol, hexyl diglycol, methyl propylene glycol, methyl propylene diglycol, methyl propylene triglycol, propyl propylene glycol, propyl propylene diglycol, butyl propylene glycol, butyl propylene diglycol, butyl propylene triglycol, and methyl propylene glycol acetate; and glycol diethers such as dimethyl glycol, dimethyl diglycol, dimethyl triglycol, methyl ethyl diglycol, diethyl diglycol, dibutyl diglycol, and dimethyl propylene diglycol.

[0052] In addition, in the above formula (2), R 2 or R 3 , especially R 3is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, in particular in terms of improved print unevenness, gloss, and dot size. 1 and R 3 In terms of excellent wetting and spreading of the ink, glycol monoethers in which one is hydrogen and the other is an alkyl group are preferred. In terms of drying properties and printing stability of the printed matter, glycol monoethers in which one is hydrogen and the other is an alkyl group are preferred. 2 The carbon number of the ethylene glycol (mono- or di-)ether is preferably 2 or 3, and more preferably 2.

[0053] The metallic ink composition contains alkylene glycol, which is a type of glycol ether solvent. It is also preferable that the composition contains choline ethers or alkylene glycol ether esters.

[0054] The alkylene glycol ethers may be monoethers or diethers of alkylene glycol, and alkyl ethers are preferred. Specific examples include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, and propylene glycol monomethyl ether. and alkylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl butyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol methyl butyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and tripropylene glycol dimethyl ether.

[0055] Examples of the alkylene glycol ether esters include glycol monoacetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and methoxybutyl acetate; Examples of glycol diesters include ethylene glycol diacetate, propylene glycol diacetate, dipropylene glycol diacetate, ethylene glycol acetate propionate, ethylene glycol acetate butyrate, diethylene glycol acetate butyrate, diethylene glycol acetate propionate, diethylene glycol acetate butyrate, propylene glycol acetate propionate, propylene glycol acetate butyrate, dipropylene glycol acetate butyrate, and dipropylene glycol acetate propionate.

[0056] The metallic ink composition also preferably contains a lactone. By containing a cyclic lactone, it is possible to dissolve a part of a low-absorbency recording medium (for example, a vinyl chloride resin) and allow the ink composition to penetrate into the inside of the recording medium. By allowing the ink composition to penetrate into the inside of the recording medium in this way, it is possible to improve the abrasion resistance of the image recorded on the recording medium.

[0057] The term "lactone" refers to a general term for a cyclic compound having an ester group (-CO-O-) in the ring. The lactone is not particularly limited as long as it is included in the above definition, but is preferably a lactone having 2 to 9 carbon atoms. Specific examples of such lactones include α-ethyl lactone, α-acetolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, ε-caprolactone, ζ-enantiolactone, η-caprylolactone, γ-valerolactone, γ-heptalactone, γ-nonalactone, β-methyl-δ-valerolactone, 2-butyl-2-ethylpropiolactone, α,α-diethylpropiolactone, etc., and among these, γ-butyrolactone is particularly preferred. The lactones exemplified above may be used alone or in combination of two or more.

[0058] The metallic ink composition may further contain other solvents. In addition, the metallic ink composition may contain solvents such as esters, ketones, alcohols, amides, alkanediols, and pyrrolidones in addition to the compounds exemplified above.

[0059] When the metallic ink composition is a solvent-based ink, the total solvent content, when the total mass of the composition is 100 mass%, is preferably 40 mass% or more, more preferably 50 mass% or more, even more preferably 60 mass% or more, and particularly preferably 70 mass% or more; the upper limit is preferably 99 mass% or less, and more preferably 98% or less.

[0060] On the other hand, when the metallic ink composition is an aqueous ink, the total content of the solvent is, when the total mass of the ink composition is 100 mass%, preferably 5 mass% or more, more preferably 10 mass% or more, even more preferably 15 mass% or more, and particularly preferably 20 mass% or more, and the upper limit is more preferably 50 mass% or less.

[0061] (Surfactant) The metallic ink composition may contain a silicone-based surfactant, a fluorine-based surfactant, or a polyoxyethylene derivative which is a nonionic surfactant, from the viewpoint of reducing the surface tension and improving the wettability with the recording medium.

[0062] As the silicone surfactant, polyester-modified silicone or polyether-modified silicone is preferably used. Specific examples include BYK-315, 315N, 347, 348, BYK-UV3500, 3510, 3530, and 3570 (all manufactured by BYK Japan).

[0063] As the fluorine-based surfactant, it is preferable to use a fluorine-modified polymer. Specific examples thereof include BYK-340 (manufactured by BYK Japan), Megafac series such as Megafac F-251, 430, 477, 552, 553, 554, 556, 557, 559, 562, 563, 565, Megafac R-40 (manufactured by DIC Corporation), Surflon S-242, 243, 386, Examples of such surfactants include the Surflon series (manufactured by AGC Seiki Chemical Co., Ltd.), such as 420, 431, 611, 647, 651, 656, 658, and 693; and the Futergent series (manufactured by Neos Corporation), such as Futergent 251, 208M, 212M, 215M, 250, 209F, 222F, 245F, 208G, 218GL, 240G, 212P, 220P, 228P, FTX-218, and DFX-18.

[0064] As the polyoxyethylene derivative, it is preferable to use an acetylene glycol surfactant.Specific examples include Surfynol 82, 104, 465, 485, TG (all manufactured by Air Products Japan Co., Ltd.), Olfin STG, E1010 (all manufactured by Nissin Chemical Co., Ltd.), Nissan Nonion A-10R, A-13R (all manufactured by NOF Corp.), Flourene TG-740W, D-90 (manufactured by Kyoeisha Chemical Co., Ltd.), Noigen CX-100 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), etc.

[0065] The surfactant may contain an acetylene glycol surfactant or a polysiloxane surfactant. The acetylene glycol surfactant and the polysiloxane surfactant can increase the wettability of the recording surface of a recording medium and the like, thereby increasing the permeability of the ink. Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyne-3-ol, and 2,4-dimethyl-5-hexyne-3-ol. In addition, commercially available acetylene glycol surfactants can be used, such as Olfin E1010, STG, and Y (all manufactured by Nissin Chemical Industry Co., Ltd.), and Surfynol 104, 82, 465, 485, and TG (all manufactured by Air Products and Chemicals Inc.). As the polysiloxane-based surfactant, commercially available products can be used, such as BYK-347 and BYK-348 (both manufactured by BYK Japan Co., Ltd.). Furthermore, the metallic ink composition can also contain other surfactants such as anionic surfactants, nonionic surfactants, and amphoteric surfactants.

[0066] The surfactant preferably contains an acetylene glycol surfactant or a polysiloxane surfactant. The acetylene glycol surfactant and the polysiloxane surfactant can increase the wettability and the permeability of the coating object. Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyne-3-ol, and 2,4-dimethyl-5-hexyne-3-ol. The acetylene glycol surfactant may be a commercially available product, such as Olfin E1010, STG, and Y (all manufactured by Nissin Chemical Industry Co., Ltd.), Surfynol 104, 82, 465, 485, and TG (all manufactured by Air Products and Chemicals Inc.). As the polysiloxane surfactant, commercially available products can be used, such as BYK-347 and BYK-348 (both manufactured by BYK Japan Co., Ltd.). In addition, other surfactants such as anionic surfactants, nonionic surfactants, and amphoteric surfactants can also be added to the water-based paint composition. Examples of such surfactants include Disperbyk102 (manufactured by BYK Japan Co., Ltd.) and Disparlon DA-325 (manufactured by Kusumoto Chemical Co., Ltd.).

[0067] When a surfactant is used in the metallic ink composition, the content of the surfactant in the composition is preferably 0.05% by mass or more and 3% by mass or less, and more preferably 0.5% by mass or more and 2% by mass or less.

[0068] (resin) The metallic ink composition may contain a resin for fixing the metallic pigment to a recording medium (hereinafter, also referred to as a "fixing resin").

[0069] Examples of fixing resins include acrylic resins, rosin-modified resins, phenolic resins, terpene resins, polyester resins, polyamide resins, epoxy resins, vinyl acetate resins, vinyl chloride resins, fiber-based resins such as cellulose acetate butyrate, vinyltoluene-α-methylstyrene copolymer resins, etc. Among these, at least one resin selected from the group consisting of acrylic resins and vinyl chloride resins is preferred. By including these fixing resins, the fixing property to the recording medium can be improved, and the abrasion resistance can also be improved.

[0070] The solid content of the fixing resin in the metallic ink composition is preferably 0.05% by mass or more and 15% by mass or less, and more preferably 0.1% by mass or more and 10% by mass or less. When the resin content is within the above range, excellent fixation properties can be obtained for low absorbency recording media.

[0071] As the acrylic resin, a copolymer made of a conventionally known polymerizable monomer can be used. As the polymerizable monomer, for example, acrylic acid esters such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, etc.; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, etc.; acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, mono-n-butyl maleate, mono-n-butyl fumarate, mono-n-butyl itaconate, etc., as well as hydroxyl group-containing (meth)acrylic acid esters, amide group-containing monomers, glycidyl group-containing monomers, cyano group-containing monomers, hydroxyl group-containing allyl compounds, tertiary amino group-containing monomers, alkoxysilyl group-containing monomers, etc. can be used alone or in combination. The acrylic resin may be a copolymer of an acrylic monomer and another monomer, such as a styrene-acrylic resin, and is preferably an acrylic resin using 90% by mass or more of the acrylic monomer, more preferably 95% by mass or more, and even more preferably 99% by mass or more of the monomer.

[0072] The acrylic resin may be a commercially available product, such as ACRYPET MF (trade name, manufactured by Mitsubishi Rayon Co., Ltd., acrylic resin), Sumipex LG (trade name, manufactured by Sumitomo Chemical Co., Ltd., acrylic resin), Paraloid B series (trade name, manufactured by Rohm and Haas Co., Ltd., acrylic resin), Parapet G-1000P (trade name, manufactured by Kuraray Co., Ltd., acrylic resin), and UC-3000 (trade name, manufactured by Toagosei Co., Ltd., acrylic resin). In the present invention, the acrylic monomer includes a (meth)acrylic monomer, and for example, (meth)acrylic acid means one or both of acrylic acid and methacrylic acid, and (meth)acrylate means one or both of acrylate and methacrylate.

[0073] When the metallic ink composition contains an acrylic resin, an image with better fixability can be formed.

[0074] Examples of vinyl chloride resins include copolymers of vinyl chloride with other monomers such as vinyl acetate, vinylidene chloride, acrylic acid, maleic acid, and vinyl alcohol. Among these, copolymers containing structural units derived from vinyl chloride and vinyl acetate (hereinafter also referred to as "vinyl chloride-vinyl acetate copolymers") are preferred, and vinyl chloride-vinyl acetate copolymers having a glass transition temperature of 60 to 80°C are more preferred.

[0075] The vinyl chloride-vinyl acetate copolymer can be obtained by a conventional method, for example, suspension polymerization. Specifically, water, a dispersant, and a polymerization initiator are charged into a polymerization vessel, and after degassing, vinyl chloride and vinyl acetate are injected to carry out suspension polymerization, or a part of the vinyl chloride and vinyl acetate are injected to start the reaction, and the remaining vinyl chloride is injected during the reaction to carry out suspension polymerization.

[0076] The vinyl chloride-vinyl acetate copolymer preferably contains 70 to 90% by mass of vinyl chloride units as its composition. If the content is within the above range, the copolymer is stably dissolved in the ink composition, and therefore has excellent long-term storage stability. Furthermore, the copolymer has excellent ejection stability and excellent fixability to a recording medium.

[0077] The vinyl chloride-vinyl acetate copolymer may contain other structural units, such as carboxylic acid units, vinyl alcohol units, etc., in addition to the vinyl chloride units and vinyl acetate units, as necessary. Examples of monomers that give hydroxyalkyl acrylate units include hydroxyalkyl acrylate units, and particularly vinyl alcohol units are preferred. They can be obtained by using monomers that correspond to the above-mentioned units. Specific examples of monomers that give carboxylic acid units include maleic acid, itaconic acid, maleic anhydride, itaconic anhydride, acrylic acid, and methacrylic acid. Specific examples of monomers that give hydroxyalkyl acrylate units include hydroxyethyl (meth)acrylate and hydroxyethyl vinyl ether. The content of these monomers is not limited as long as it does not impair the effects of the present invention, but can be copolymerized within a range of, for example, 15% by mass or less of the total amount of monomers.

[0078] Furthermore, the vinyl chloride-vinyl acetate copolymer may be a commercially available product, for example, Solvine CN, Solvine CNL, Solvine C5R, Solvine TA5R, Solvine CL, Solvine CLL (all manufactured by Nissin Chemical Industry Co., Ltd.).

[0079] The average degree of polymerization of these resins is not particularly limited, but is preferably 150 to 1100, and more preferably 200 to 750. When the average degree of polymerization of these resins is within the above range, they dissolve stably in the metallic ink composition, and therefore the long-term storage stability is excellent. Furthermore, they are excellent in ejection stability, and excellent fixability to the recording medium can be obtained. The average degree of polymerization of these resins is calculated by measuring the specific viscosity, and is based on the "JIS The average degree of polymerization can be calculated in accordance with the method for calculating the average degree of polymerization described in "K6720-2".

[0080] Furthermore, the number average molecular weight of these resins is not particularly limited, but is preferably from 10,000 to 50,000, and more preferably from 12,000 to 42,000. The number average molecular weight can be measured by GPC, and can be determined as a relative value converted into polystyrene.

[0081] (others) In addition to the above components, the metallic ink composition may contain substances for imparting specified performance, such as chelating agents such as ethylenediaminetetraacetate (EDTA), preservatives, viscosity adjusters, dissolution aids, antioxidants, and fungicides.

[0082] When the metallic ink composition is a water-based ink, a tertiary amine, an alkanediol, a polyhydric alcohol, a pyrrolidone derivative, a pH adjuster, a buffer solution, or the like may be added.

[0083] Tertiary amines have the function of improving the water dispersibility and storage stability of metallic pigments. Examples of tertiary amines include hydroxylamines such as triethanolamine, tripropanolamine, tributanolamine, N,N-dimethyl-2-aminoethanol, and N,N-diethyl-2-aminoethanol. Among these, triethanolamine and tripropanolamine are preferred in that they can further improve water dispersibility, and triethanolamine is more preferred in that they can improve storage stability in addition to water dispersibility.

[0084] The buffer solution may be any of the conventionally known buffer solutions, so long as it can maintain the pH of the metallic ink composition in the range of, for example, 5.0 to 8.5. Examples of the buffer solution that may be used include Good's buffers such as 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), morpholinoethanesulfonic acid (MES), carbamoylmethyliminobisacetic acid (ADA), piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-(2-acetamido)-2-aminoethanesulfonic acid (ACES), cholamine hydrochloride, N,N-bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES), N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid (TES), acetamidoglycine, tricine, glycineamide, and bicine, phosphate buffer solutions, and Tris buffer solutions.

[0085] The alkanediol can increase the wettability of the recording surface of a recording medium and the like, thereby increasing the permeability of the ink. As the alkanediol, a 1,2-alkanediol having 4 to 8 carbon atoms, such as 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, or 1,2-octanediol, is preferred. Among these, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol having 6 to 8 carbon atoms are more preferred because they have particularly high permeability into a recording medium.

[0086] For example, when the aqueous ink composition is applied to an inkjet recording device, the polyhydric alcohol can suppress drying of the aqueous ink composition and prevent clogging of the inkjet recording head with the aqueous ink composition.

[0087] Examples of pyrrolidone derivatives include N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-pyrrolidone, and 5-methyl-2-pyrrolidone.

[0088] Examples of pH adjusters include potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydroxide, lithium hydroxide, potassium hydroxide, ammonia, diethanolamine, triethanolamine, triisopropanolamine, potassium carbonate, sodium carbonate, and sodium hydrogen carbonate.

[0089] 1.1.2. Properties and physical characteristics of metallic ink composition When the metallic ink composition is a solvent-based ink, it may contain 40.0% by mass or more of a glycol ether-based solvent based on the total amount of the composition. In this case, a better recorded matter can be obtained using the solvent-based ink. In this case, the glycol ether-based solvent is more preferably 50% by mass or more, more preferably 60% by mass or more. The upper limit is not limited, but 99% by mass or less is preferable.

[0090] The metallic ink composition may contain 40.0% by mass or more of a glycol ether solvent having a flash point of 70.0° C. or less, based on the total amount of the composition. In this case, it is possible to obtain better recorded matter using the solvent-based ink. The content is preferably 50 to 99% by mass, more preferably 60 to 90% by mass.

[0091] With regard to the flash point, if the flash point measured by the TAG closed cup flash point tester is not 80°C or lower, the flash point measured by the Cleveland open cup flash point tester shall be used; if the flash point measured by the TAG closed cup flash point tester is 80°C or lower and the kinetic viscosity of the solvent at the flash point is less than 10 cSt, the flash point measured by the TAG closed cup flash point tester shall be used; if the kinetic viscosity of the solvent at the flash point is 10 cSt or higher, the flash point measured by the Seta closed cup flash point tester shall be used.

[0092] Examples of glycol ether solvents having a flash point of 70.0° C. or less include diethylene glycol methyl ethyl ether (64° C.), diethylene glycol dimethyl ether (56° C.), and dipropylene glycol dimethyl ether (65° C.).

[0093] The flash point is, for example, preferably from 50° C. to 70° C., more preferably from 55° C. to 70° C., even more preferably from 60° C. to 70° C., and particularly preferably from 62° C. to 68° C. When the flash point is 70° C. or less, the effect of improving the drying property of the ink composition is good, and prevention of color mixing, improvement of gloss, and prevention of show-through are more excellent and preferable.

[0094] In addition, glycol ether solvents include those with a flash point of over 70°C. Examples of glycol ether solvents having a flash point of more than 70° C. include diethylene glycol diethyl ether (flash point: 71° C.) and triethylene glycol monobutyl ether (156° C.).

[0095] The flash point of a glycol ether solvent having a flash point of more than 70° C. is preferably 160° C. or less, and more preferably 120° C. or less, which is preferable in terms of excellent wetting and spreading of the ink onto the recording medium.

[0096] The viscosity of the metallic ink composition at 20° C. is preferably 2 mPa·s or more and 15 mPa·s or less. When the viscosity of the metallic ink composition at 20° C. is within this range, an appropriate amount of the metallic ink composition is ejected from the nozzle, and deflection and scattering of the metallic ink composition can be further reduced, making the metallic ink composition suitable for use in inkjet recording devices.

[0097] The metallic ink composition can be obtained by mixing the above-mentioned components in an appropriate order and removing impurities as necessary by filtration, etc. As a method for mixing the components, a method in which the materials are added to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer and stirred and mixed is preferably used.

[0098] 1.2.Heating process In the inkjet recording method of this embodiment, the metallic ink composition attached to the recording medium is heated by an IR heater.

[0099] 1.2.1.Infrared heater (IR heater) The infrared radiation can be irradiated by, for example, an infrared heater (IR heater) as exemplified in the inkjet recording device described later. The type of the infrared heater is not particularly limited as long as the infrared radiation (IR) reaches the recording surface side of the recording medium.

[0100] The infrared rays irradiated in the heating step can heat the recording medium and / or the image formed on the recording medium, thereby evaporating volatile components contained in the image and drying it.

[0101] Heating by an IR heater can dry the composition intensively at the position where infrared rays are irradiated. Therefore, when the recording medium is transported, heating by infrared rays is not performed or is gentle at the position where infrared rays are not irradiated. Therefore, for example, even if an IR heater is disposed adjacent to a recording head, infrared rays can be prevented from being irradiated at that position immediately after the composition discharged from the recording head adheres to the recording medium. Therefore, drying of the adhered composition immediately after adhesion can be suppressed.

[0102] By using an IR heater in the heating step of this embodiment, for example, it is possible to suppress drying of the metallic ink composition immediately after it is applied to a recording medium, which allows sufficient time for leafing of the metallic pigment in the applied droplets when the metallic ink composition contains a plate-like metallic pigment.

[0103] Here, leafing refers to the phenomenon in which flat particles of a metallic pigment fall onto a recording medium while the normal direction of the flat particles approaches parallel to the normal direction of the recording medium. If leafing is sufficient, the metallic luster of the resulting image can be made very excellent. On the other hand, if leafing is insufficient, there will be many particles whose normal direction of the flat particles differs from the normal direction of the recording medium, and the image may have insufficient luster. Furthermore, leafing is likely to occur when liquid components are present in the metallic ink composition when it is applied to the recording medium. For example, there may be a decrease in the liquid components due to drying, thickening due to the decrease in the liquid components, or adhesion to the recording medium. The reduction in the liquid component due to absorption suppresses leafing. In the inkjet recording method of the present embodiment, the heating step is performed by irradiating infrared rays with an IR heater, so that leafing can be promoted and an image with excellent metallic luster can be obtained.

[0104] Infrared heating has good thermal efficiency and can suppress expansion and contraction of the recording medium due to heating (hereinafter also referred to as "damage to the recording medium" or "deformation due to thermal damage") while ensuring leafing time.

[0105] The surface temperature of the recording medium in the heating step is not particularly limited, but is, for example, from 25° C. to 70° C., preferably from 28° C. to 65° C., more preferably from 30° C. to 60° C., and even more preferably from 32° C. to 58° C. By keeping the temperature within this range, the metallic ink composition can be dried sufficiently, and color mixing when the colored ink composition is attached can be further suppressed.

[0106] The surface temperature of the recording medium can be measured, for example, by using an infrared sensor (IR sensor). In this specification, the surface temperature of the recording medium during the heating process refers to the highest surface temperature of the recording medium in the portion subjected to the process while the process is being performed.

[0107] In the heating step, the recording medium may be heated for a period of time during which the surface temperature of a portion of the recording medium to which the metallic ink composition is attached reaches 28° C. or higher for 1 second to 120 seconds, preferably 3 seconds to 100 seconds, more preferably 10 seconds to 80 seconds, and preferably 20 seconds to 60 seconds. In this way, the metallic ink composition can be dried and color mixing with the colored ink composition can be further suppressed. The period is more preferably 30.0 seconds to 50 seconds, and even more preferably 40.0 seconds to 45 seconds. The heating time during which the surface temperature of the recording medium reaches the above range when the heating step is performed using only an IR heater and the temperature is confirmed may be within the above range.

[0108] The heating step may be performed using other heating means in addition to the above-mentioned IR heater. Such heating means include a preheater, a platen heater, and / or an afterheater. When a preheater, a platen heater, or an afterheater is used, it is more preferable that these heaters are conductive heaters.

[0109] If heating using a conductive heater is further used in the heating step, the drying speed of the metallic ink composition and the colored ink composition in the heating step can be further increased, thereby further suppressing color mixing of the metallic ink composition and the colored ink composition.

[0110] When a preheater is used in the heating step, it is preferable not to raise the temperature of the recording medium too high when the metallic ink composition is applied, but using a preheater has the advantage that it is easier to maintain the temperature of the recording medium at a specific temperature when the metallic ink composition is applied.

[0111] Also, even when a platen heater is used in the heating step, it is preferable not to raise the temperature of the recording medium too high when the metallic ink composition is applied. However, the use of a platen heater has the advantage that the temperature of the recording medium when the metallic ink composition is applied can be easily maintained at a specific temperature. In addition, it is preferable to use a platen heater within a range in which leafing of the metallic ink composition is sufficient, since this can further promote drying by the IR heater.

[0112] The heating step is a step of moving air around the recording medium by a blower mechanism (blower type). The air blowing mechanism used to move the air around the recording medium may blow air at room temperature or may blow warm air (hot air), which is preferable. For example, warm air is blown onto the recording medium. By using air blowing in combination with the heating step, the drying efficiency of the metallic ink composition and the colored ink composition can be further increased, which is more preferable.

[0113] 1.3. Colored ink application process In the color ink applying step, a color ink composition containing a coloring material is ejected from an inkjet head to be applied to the metallic ink composition on the recording medium.

[0114] 1.3.1. Colored ink composition The colored ink composition is an ink composition that contains a coloring material.

[0115] (1) Coloring materials The coloring material contained in the coloring ink composition is a coloring material that colors an image formed by the metallic ink composition as a color metallic image. The "coloring material" is a coloring material for coloring a color other than the metallic color colored by the metallic ink. Examples of the coloring material include chromatic colors and a series of colors from white through gray to black (achromatic colors). The coloring material is a color selected from these colors. Chromatic colors are preferred. As the coloring material, either pigments or dyes can be used, but organic pigments are preferred from the viewpoint of storage stability such as light resistance, weather resistance, and gas resistance. Examples of the coloring ink composition include cyan ink, yellow ink, magenta ink, and black ink, which are called process color inks.

[0116] Specific examples of color pigments include azo pigments such as insoluble azo pigments, condensed azo pigments, azo lakes, and chelate azo pigments, polycyclic pigments such as phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments, dye chelates (e.g., basic dye chelates, acid dye chelates, etc.), dye lakes (basic dye lakes, acid dye lakes), nitro pigments, nitroso pigments, aniline black, and daylight fluorescent pigments. The above pigments may be used alone or in combination of two or more. More specifically, for example, CI Pigment Yellow 1 (Fast Yellow G), 2, 3, 12 (Disazo Yellow AAA), 13, 14, 16, 17, 24, 34, 35, 37, 42 (Yellow Iron Oxide), 53, 55, 73, 74, 75, 81, 83 (Disazo Yellow HR), 93, 94, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 1 29, 138, 139, 150, 153, 154, 155, 180, 185, 213, CI Pigment Red 1, 2, 3, 5, 7, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48:2 (Permanent Red 2B (Ba)), 48:2 (Permanent Red 2B (Ca)), 48:3 (Permanent Red 2B (Sr)), 48:4 (Permanent Red 2B (Mn)), 49:1, 52:2, 53:1, 57:1 (Brilliant Carmine 6B), 60:1, 63:1, 63:2, 64:1, 81 (Rhodamine 6G Lake), 83, 88, 101 (Red oxide), 104, 105, 106, 112, 114, 122 (Quinacridone Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 209, 219, CI Pigment Violet 19, CI Pigment Blue 1, 2, 15 (Phthalocyanine Blue R), 15:1, 15:2, 15:3 (Phthalocyanine Blue G), 15:4, 15:6 (Phthalocyanine Blue E), 16, 17:1, 22, 56, 60, 63, CI Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, etc. can be used.Pigments not listed in the Color Index may also be used.

[0117] In the case where a pigment is used as a coloring material in the color ink composition, the pigment is dispersed in a solvent. The dispersant used can be any dispersant that can be used in this type of pigment ink without any particular limitation, and examples of the dispersant include cationic dispersants, anionic dispersants, nonionic dispersants, surfactants, etc.

[0118] Examples of anionic dispersants include polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymers, vinyl acetate-acrylic acid ester copolymers, acrylic acid-acrylic acid alkyl ester copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-acrylic acid-acrylic acid alkyl ester copolymers, styrene-methacrylic acid-acrylic acid alkyl ester copolymers, styrene-α-methylstyrene-acrylic acid copolymers, styrene-α-methylstyrene-acrylic acid-acrylic acid alkyl ester copolymers, styrene-maleic acid copolymers, vinylnaphthalene-maleic acid copolymers, vinyl acetate-ethylene copolymers, vinyl acetate-fatty acid vinylethylene copolymers, vinyl acetate-maleic acid ester copolymers, vinyl acetate-crotonic acid copolymers, and vinyl acetate-acrylic acid copolymers.

[0119] Examples of the nonionic dispersant include polyvinylpyrrolidone, polypropylene glycol, and vinylpyrrolidone-vinyl acetate copolymer.

[0120] Examples of surfactants as dispersants include anionic surfactants such as sodium dodecylbenzenesulfonate, sodium laurate, and ammonium salts of polyoxyethylene alkyl ether sulfates, and nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl amines, and polyoxyethylene alkyl amides. In particular, from the viewpoint of increasing the dispersion stability of the pigment, it is preferable to use a styrene-(meth)acrylic acid copolymer.

[0121] Dyes may be used as coloring materials. Examples of such dyes include water-soluble dyes such as acid dyes, direct dyes, reactive dyes, and basic dyes, and water-dispersible dyes such as disperse dyes, oil-soluble dyes, and sublimation dyes.

[0122] The coloring materials exemplified above are preferred examples of coloring materials, and the present invention is not limited thereto. These coloring materials may be used alone or in combination of two or more kinds, or a pigment and a dye may be used in combination.

[0123] The content of the coloring material in the colored ink composition can be appropriately adjusted, but is preferably from 0.10% by mass to 20.0% by mass, more preferably from 0.20% by mass to 15.0% by mass, even more preferably from 1.0% by mass to 10.0% by mass, and even more preferably from 1.5% by mass to 5.0% by mass.

[0124] (2) Other ingredients The colored ink composition may contain the components exemplified above in "1.1.1. Metallic ink composition (2) Other components". The water, organic solvents, surfactants, resins, chelating agents, preservatives, viscosity modifiers, dissolution aids, antioxidants, antifungal agents, tertiary amines, alkanediols, polyhydric alcohols, pyrrolidone derivatives, pH adjusters, buffer solutions, and the like that may be contained in the colored ink composition, including their amounts, are as described above, and therefore will not be described here.

[0125] 1.3.2. Properties and physical characteristics of colored ink compositions The colored ink composition can be a water-based ink or a solvent-based ink. When the colored ink composition is a solvent-based ink, it is preferable to use a glycol ether as described above for the metallic ink. The composition may contain 40.0% by mass or more of an ether-based solvent based on the total amount of the composition, in which case better recorded matter can be obtained using a solvent-based ink.

[0126] The colored ink composition may contain 40.0% by mass or more of a glycol ether solvent having a flash point of 70.0° C. or less, based on the total amount of the composition, as described above for the metallic ink composition. In this case, it is possible to obtain better recorded matter using a solvent-based ink.

[0127] The viscosity of the colored ink composition at 20° C. is preferably from 2 mPa·s to 10 mPa·s, and more preferably from 3 mPa·s to 5 mPa·s. When the viscosity of the colored ink composition at 20° C. is within this range, an appropriate amount of the colored ink composition is ejected from the nozzle, and deflection and scattering of the colored ink composition can be further reduced, making the colored ink composition suitable for use in inkjet recording devices.

[0128] The colored ink composition can be obtained by mixing the above-mentioned components in an appropriate order and removing impurities as necessary by filtration, etc. As a method for mixing the components, a method in which the materials are added to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer and stirred and mixed is preferably used.

[0129] 1.4. Inkjet recording method In the inkjet recording method of this embodiment, an inkjet head is driven to eject droplets of the metallic ink composition and the colored ink composition, and the droplets are deposited on a recording medium to form an image.

[0130] In the case where a metallic ink composition containing a metallic pigment and a colored ink composition containing a coloring material are ejected separately, for example, it is preferable to form an image having a metallic luster using the metallic ink composition and then form an image using the colored ink composition.

[0131] Regardless of whether the recording medium has an ink-receiving layer or not, the metallic pigment does not easily penetrate into the ink-receiving layer and remains in a state of being attached to the recording medium. In contrast, the coloring material contained in the colored ink composition easily penetrates into the ink-receiving layer when ejected onto a recording medium having an ink-receiving layer. For this reason, if a metallic ink composition containing a metallic pigment is first ejected onto a recording medium to form an attachment layer of the metallic pigment, and then the coloring material of the colored ink composition is attached onto the layer, the color of the coloring material of the colored ink composition can be more vividly developed.

[0132] Examples of a method for ejecting the metallic ink composition or the colored ink composition include the methods described below.

[0133] The first method is the electrostatic attraction method, in which a strong electric field is applied between the nozzle and an accelerating electrode placed in front of the nozzle, causing ink to be continuously ejected from the nozzle in the form of liquid droplets, and a print information signal is applied to the deflection electrodes while the ink droplets fly between the deflection electrodes to record, or the ink droplets are ejected in response to the print information signal without being deflected.

[0134] The second method is to forcefully eject ink droplets by applying pressure to the ink liquid with a small pump and mechanically vibrating the nozzle with a quartz crystal oscillator, etc. The ejected ink droplets are charged at the same time as they are ejected, and a print information signal is applied to the deflection electrodes while the ink droplets fly between the deflection electrodes to record the data.

[0135] The third method is to use a piezoelectric element, which simultaneously applies pressure and a printing information signal to the ink liquid, ejecting ink droplets and recording.

[0136] The fourth method is to use thermal energy to rapidly expand the volume of the ink liquid, heating and foaming the ink liquid with microelectrodes in accordance with printing information signals, and ejecting and recording ink droplets.

[0137] Although any of the above methods use an inkjet head and can be used in the inkjet recording method of the present embodiment, from the viewpoint of high-speed printing, it is preferable that the method for ejecting the ink composition is a non-heating method, i.e., it is preferable to adopt the above-mentioned first method, second method or third method.

[0138] 1.4.1. Inkjet recording device The inkjet recording apparatus according to this embodiment includes an inkjet head that ejects the metallic ink composition described above, an infrared heater, and an inkjet head that ejects the colored ink composition described above.

[0139] According to this inkjet recording device, after the metallic ink is applied, the metallic ink composition is dried by an IR heater, and then the colored ink composition is applied. In this manner, the colored ink composition is applied in a state in which the metallic ink composition is sufficiently dried, so that a color metallic image of good quality can be obtained in which color mixing of the metallic ink composition and the colored ink composition is suppressed.

[0140] An example of an inkjet recording apparatus suitable for the inkjet recording method of the present embodiment will be described below with reference to the drawings. The inkjet recording apparatus for carrying out the inkjet recording method according to the present embodiment can easily carry out the metallic ink applying step, the heating step, and the colored ink applying step.

[0141] FIG. 1 is a schematic diagram showing a cross section of an inkjet recording apparatus 100. FIG. 2 is a schematic diagram showing a cross section of an IR heater. The inkjet recording apparatus 100 includes a recording head 12, a recording head 14, an IR heater 50, a pre-heater 82, a front cover 32, a rear cover 34, a platen heater 84, an after-heater 86, a transport roller 40, a supply roll 62, and a take-up roll 64. The operation of the inkjet recording apparatus 100 as a whole is controlled by a control unit (not shown). The IR heater 50 is an infrared heater used in the heating process described above.

[0142] The recording head 12 is provided upstream of the recording head in the transport direction (see the arrow in the figure) of the recording medium M. Between the recording head 12 and the recording head , an IR heater 50 is provided.

[0143] The recording head 12 is configured to eject at least a metallic ink composition from nozzles and deposit it onto the recording medium M, thereby performing recording. The recording head 12 is a line-type recording head, and as the recording medium M is transported by transport rollers 40, the relative position of the recording head 12 with respect to the recording medium M changes, allowing the metallic ink composition to be deposited to form a predetermined image. The recording head 12 is mounted on a housing (not shown).

[0144] The metallic ink composition is supplied to the recording head 12 via, for example, a cartridge, a tube, a tank, or the like. A conventionally known method can be used for ejecting the ink from the recording head 12. In this embodiment, a method of ejecting droplets by utilizing the vibration of a piezoelectric element, that is, an ejection method of forming ink droplets by mechanical deformation of an electrostrictive element, is used.

[0145] The recording head 14 performs recording by ejecting and depositing a colored ink composition from a nozzle. This is a configuration for recording on a medium M. The recording head 14 is a line-type recording head, and similarly to the recording head 12, when the recording medium M is transported by a transport roller 40, the relative position with respect to the recording medium M moves, and a predetermined image can be formed by depositing a colored ink composition. The recording head 14 is mounted on a housing (not shown).

[0146] The recording heads 12 and 14 may be serial type recording heads. In this case, the recording heads are mounted on a carriage (not shown). Recording is performed by performing main scanning, which deposits ink on the recording medium while the carriage moves in the main scanning direction (the direction perpendicular to the paper surface in the figure), and sub-scanning, which transports the recording medium in the transport direction, multiple times each. The main scanning and sub-scanning are performed alternately.

[0147] The color ink composition is supplied to the recording head 14 via, for example, a cartridge, a tube, a tank, or the like. A plurality of cartridges or the like may be mounted, and each of the plurality of cartridges may be filled with a different type of ink. The color ink composition is supplied to each nozzle of the recording head 14 from the cartridge or the like.

[0148] The IR heater 50 is provided between the recording head 12 and the recording head 14 in the transport direction of the recording medium M (see the arrow in the figure). This makes it possible to carry out a heating step of heating the metallic ink composition ejected from the recording head 12 and attached to the recording medium M. Thereafter, the colored ink composition ejected from the recording head 14 can be attached to the metallic ink composition after the heating step.

[0149] The position of the IR heater 50 is not limited to the position shown in the figure, and may be any position that allows heating of the metallic ink composition attached to the recording medium. For example, in the case of a serial type recording head, the IR heater 50 may be mounted on a carriage that carries the recording head 14 or 12. The recording heads 12 and 14 may be mounted on the same carriage, and the IR heater 50 may be mounted on the carriage. The position of the IR heater 50 in the conveying direction of the recording medium is preferably a position overlapping with the recording head 12 or 14, or a position between the recording heads 12 and 14. The recording head 12, the recording head 14, and the IR heater 50 may be mounted on the same carriage, and the IR heater 50 may be located between the recording heads 12 and 14.

[0150] By using the IR heater 50, the recording medium M can be heated by radiation using infrared radiation from the side of the recording medium M on which the metallic ink composition is attached. This allows heating to be performed without being affected by the thickness of the recording medium M, as compared to when the recording medium M is heated from its rear surface. In addition, although not shown, various types of fans may be provided that blow hot air or air at the same temperature as the environment onto the recording medium M to dry the ink and treatment liquid on the recording medium M. Details of the IR heater 50 will be described later.

[0151] In the inkjet recording apparatus 100, the recording medium M is a continuous medium, and is transported from the supply roll 82 towards the take-up roll 86. The recording medium M is transported by transport rollers 40. Although only a pair of transport rollers 40 is shown in the illustrated example, the number of transport rollers 40 is arbitrary. The inkjet recording apparatus 100 may also have a transport belt (not shown) or the like.

[0152] The inkjet recording apparatus 100 may include a preheater 82, which can heat the recording medium M before it reaches the recording head 12. The preheater 82 is a conductive heater. In the illustrated example, the preheater 82 is configured to come into contact with the surface of the recording medium M opposite to the recording surface. The preheater 82 may be arranged to heat both sides of the recording medium M. The preheater 82 may be located upstream of the recording head 12 in the transport direction of the recording medium M (see the arrow in the figure), and may be located upstream of the transport roller 40 in the transport direction of the recording medium M. It may be arranged on the downstream side in the direction (see the arrow in the figure).

[0153] The preheater 82 can quickly dry the metallic ink composition discharged by the recording head 12 from the time it is applied to the recording medium M. Heating of the recording medium M by the preheater 82 is performed as necessary. When heating is performed by the preheater 82, the recording medium M can be stabilized at a predetermined temperature. Heating by the preheater 82 is preferably controlled so that the surface temperature of the recording medium M is 40.0° C. or less, more preferably 35° C. or less, and even more preferably 30° C. or less. Meanwhile, 28° C. or more is preferable, and 30° C. or more is more preferable. The temperature is the maximum surface temperature of the recording medium M in the part heated by the preheater 82. The preheater 82 is a heater located upstream of the platen in the recording medium transport direction.

[0154] The inkjet recording apparatus 100 may also include a platen heater 84. This is provided at a position where the recording medium M corresponds to at least one of the recording head 12, the IR heater 50, and the recording head 14. In the illustrated example, the platen heater 84 is provided at a position where the recording medium M corresponds to all of the recording head 12, the IR heater 50, and the recording head 14. The platen heater 84 is a conductive heater. The platen heater 84 is configured to contact the surface of the recording medium M opposite to the recording surface. The conductive type is a heating method in which heat is applied to the recording medium M via a member that contacts the recording medium M to heat it. Although not illustrated, a blower mechanism may also be provided above the platen to perform heating by blowing air.

[0155] The platen heater 84 can quickly dry the metallic ink composition ejected by the recording head 12 from the moment it is applied to the recording medium M. The recording medium M is heated by the platen heater 84 as necessary. When heating is performed by the platen heater 84, the recording medium M can be stabilized at a predetermined temperature.

[0156] Heating by a conductive and / or blower type heating mechanism such as the platen heater 84 in the platen region is preferably controlled so that the surface temperature of the recording medium M is 40.0° C. or less, more preferably 35° C. or less, and even more preferably 30° C. or less. On the other hand, 28° C. or more is preferable, and 30° C. or more is more preferable. In this case, prevention of color mixing, gloss, and abrasion prevention are more excellent and preferable.

[0157] The platen heater 84 can quickly dry the metallic ink composition and the colored ink composition discharged by the recording head 12 and the recording head 14 from the time they are applied to the recording medium M.

[0158] The surface temperature of the recording medium M by the IR heater 50 is preferably 30° C. or higher. It is further preferably 35° C. or higher, more preferably 40° C. or higher, particularly preferably 45° C. or higher, even more preferably 50° C. or higher, and particularly preferably 55° C. or higher. On the other hand, the upper limit is preferably 60° C. or lower, more preferably 50° C. or lower. In this case, it is preferable because it is more excellent in preventing color mixing, improving gloss, preventing abrasion, etc.

[0159] The temperatures of the conductive heating and the IR heater heating are the maximum surface temperatures of the part of the recording medium receiving the heating when the temperature is checked by assuming that the recording medium is heated only by the conductive heating and only by the IR heater, respectively.

[0160] The inkjet recording apparatus 100 may also include an after-heater 86. This is a heating mechanism that thoroughly dries and solidifies the ink composition applied to the recording medium M to complete recording. In other words, it is a heater for secondary heating or secondary drying. It is a heater for a post-heating process that will be described later. The heating mechanism is provided downstream of the platen area in the recording medium transport direction. do.

[0161] The after-heater 86 can be used in the post-heating step. By heating the recording medium M on which an image has been recorded, the volatile components such as moisture contained in the image evaporate and dissipate more quickly, and a film is formed by the resin contained in the ink composition. In this way, the film is firmly fixed or adhered on the recording medium M, and the film-forming properties are excellent, and a high-quality image can be obtained in a short time. The upper limit of the surface temperature of the recording medium M by the after-heater 86 is preferably 120.0°C or less, more preferably 100.0°C or less, and even more preferably 90.0°C or less. In addition, the lower limit of the surface temperature of the recording medium M is preferably 40°C or more, more preferably 45°C or more, and even more preferably 50°C or more. By the temperature being within the above range, a high-quality image can be obtained in a short time. The temperature is the maximum surface temperature of the part of the recording medium that is heated by the after-heater.

[0162] Although not shown, the inkjet recording apparatus 100 may have a cooling fan. After the ink recorded on the recording medium M is dried, the ink on the recording medium M is cooled by the cooling fan, whereby an ink coating film with better adhesion can be formed on the recording medium M.

[0163] The inkjet recording apparatus 100 has a front cover 32 and a rear cover 34. The front cover 32 and the rear cover 34 are provided as necessary, for example, to prevent an operator or the like from contacting the members inside the cover. The front cover 32 and the rear cover 34 may be configured to be freely opened and closed. The operation of each component of the inkjet recording apparatus 100 is controlled by a control unit (not shown).

[0164] 1.4.2.IR Heater FIG. 2 is a schematic diagram showing a cross section of an IR heater 50 as an example of an IR heater, as viewed from a direction intersecting the direction in which the recording medium M is transported. As shown in FIG. 2, the IR heater 50 has a tube 52 arranged along a direction intersecting the direction in which the recording medium M is transported, a heating element 51 inserted into the tube 52, and a support 53 that supports the tube 52. The tube 52 is preferably made of a metal material, and particularly made of iron. It is preferable that the total length of the tube 52 along the direction intersecting the direction in which the recording medium M is transported is sufficiently longer than the width of the recording medium M along the direction intersecting the direction in which the recording medium M is transported. This allows infrared rays to be reliably irradiated toward the entire image on the recording medium M passing under the tube 52.

[0165] The heating element 51 generates heat when electricity is applied, and is composed of an electric heating wire such as a nichrome wire. When the heating element 51 generates heat, the tube 52 is heated and infrared rays are emitted. This allows volatile components such as water in the ink to evaporate, and the image can be dried. The support 53 is appropriately configured to support the tube 52 from above, and in the illustrated example, the tube 52 is supported by the housing 71 via the support 53. In addition, in the illustrated example, infrared rays are irradiated onto the recording surface Ma of the recording medium M, and a platen heater 84 that supports the recording medium M is disposed on the back side of the recording medium M.

[0166] The heating temperature when the tube 52 is heated is, for example, 300° C. or more and 700° C. or less. The surface temperature of the recording medium M during heating is preferably, for example, 30.0° C. or more and 60.0° C. or less. The output of the IR heater 50, the conveying speed of the recording medium M, and the like may be controlled so that there is a region in which the surface temperature of the recording medium M is 30.0° C. or more for a period of 1.0 seconds or more and 120.0 seconds or less, or even for a period of 20.0 seconds or more and 120.0 seconds or less.

[0167] The surface temperature of the recording medium M can be detected by using, for example, an infrared sensor. It is.

[0168] According to the inkjet recording apparatus 100 described above, recording can be easily performed by the inkjet recording method of this embodiment. The position of the IR heater 50 in the inkjet recording apparatus 100 is not limited to the above-mentioned exemplary position, and the heater may be disposed at any position as long as the deposited metallic ink composition can be dried by the IR heater and the colored ink composition can be deposited on the layer of the metallic ink composition dried by the IR heater. Examples of such a position include fixing the heater to the downstream side of the recording head 12 that ejects the metallic ink composition in the transport direction of the recording medium M (see the arrow in the figure).

[0169] Furthermore, the position of the recording head 14 that ejects the colored ink composition is not limited. As another arrangement, for example, in the case of a serial type recording device, the recording head 12 that ejects the metallic ink composition may be arranged side by side in a direction intersecting the transport direction of the recording medium M (see the arrow in the figure), and after the metallic ink composition is applied to the recording medium M, the recording medium M may be returned to the upstream side in the transport direction, so that the colored ink composition is applied to the layer of the metallic ink composition.

[0170] 1.5. Recording medium The recording medium to which the inkjet recording method of the present embodiment is applied is not particularly limited, and various recording media such as plain paper, inkjet paper (matte paper, glossy paper), glass, plastic film such as PVC, film with a plastic or receiving layer coated on a substrate, metal, printed wiring board, etc. can be used. When the recording medium has an ink receiving layer, it is preferable to print the recording medium without heating from the viewpoint of not causing thermal damage. On the other hand, when the recording medium does not have an ink receiving layer, it is preferable to print the recording medium with heating from the viewpoint of increasing the drying speed and obtaining high gloss.

[0171] 1.6. Process sequence In the inkjet recording method of this embodiment, the color ink applying step can be performed after the metallic ink applying step, but it is also preferable that the color ink composition be applied to the metallic ink composition heated in the heating step in the color ink applying step. That is, the color ink applying step may be performed after the heating step. In this way, it is possible to further suppress color mixing between the metallic ink composition and the color ink composition, and it is also possible to further improve leafing of the metallic pigment.

[0172] 1.7.Other processes In the inkjet recording method of the present embodiment, a post-heating step may be carried out after the color ink depositing step. The post-heating step differs from the heating step described above in that the recording medium is heated in the post-heating step, and can accelerate the drying of the entire ink composition on the recording medium.

[0173] The heating step can be performed, for example, by using the above-mentioned after-heater. The after-heating step may be performed by using another heating mechanism such as an infrared heater, or may be performed by using a plurality of heating mechanisms in combination. The heating means is not limited to the heating means provided in the inkjet recording apparatus, and a drying means separate from the apparatus may be used.

[0174] When the post-heating step is included, the recorded matter can be dried more quickly, and show-through and rubbing after recording can be more unlikely to occur.

[0175] The temperature of the recording medium when the post-heating step is performed is not particularly limited, but can be set, for example, in consideration of the Tg of the resin contained in the recorded matter. The temperature of the recording medium reached by heating in the post-heating step is, for example, 30.0°C or higher and 120.0°C or lower, preferably 40.0°C or higher and 100. The temperature is 0°C or lower, more preferably 50.0°C or higher but 95.0°C or lower, and particularly preferably 50°C or higher but 90.0°C or lower.

[0176] 1.8. Effects, etc. According to the inkjet recording method described above, after the metallic ink application step, the heating step is performed by an IR heater. Therefore, leafing of the metallic pigment of the metallic ink composition is sufficiently advanced, and an image having excellent metallic luster can be obtained. In addition, since the metallic ink composition is dried well, color mixing is unlikely to occur even when the colored ink composition is applied, and a beautiful color metallic image can be obtained. Furthermore, when the colored ink application step is performed after the heating step, color mixing between the metallic ink composition and the colored ink composition can be further suppressed, and leafing of the metallic pigment can be further improved.

[0177] The metallic ink composition exhibits a metallic luster in an image by leafing the metallic pigment after being applied to a recording medium, but if the metallic ink composition is dried immediately after being applied, leafing cannot be sufficiently achieved. In the inkjet recording method of the present embodiment, an IR heater is used in the heating step to prevent drying or excessive drying, thereby obtaining an image with a high metallic luster.

[0178] On the other hand, if the colored ink composition is applied without or with little heating of the metallic ink composition, there is a risk of color mixing, but by performing a heating step using an IR heater, it is possible to obtain a good metallic luster and suppress color mixing. Heating using an IR heater can be performed to a degree that suppresses color mixing while also obtaining a metallic luster. One of the reasons for this advantage is thought to be that the IR heater can gently dry the layer of the applied ink composition to the inside.

[0179] When drying is performed strongly using a platen heater, the entire recording medium is heated, and drying begins at the same time as the metallic ink composition adheres to the recording medium, resulting in insufficient time for leafing of the metallic pigment. In the inkjet recording method of the present embodiment, an IR heater is used, so the temperature of the recording medium is not high when the metallic ink composition adheres to the recording medium. Therefore, leafing progresses sufficiently. Heating by the IR heater then begins, so that drying can be performed quickly after the start of heating while ensuring leafing time.

[0180] 2. Examples and Comparative Examples The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following, "parts" and "%" are based on mass unless otherwise specified. The evaluation was performed under an environment of a temperature of 25.0°C and a relative humidity of 40.0%, unless otherwise specified.

[0181] 2.1. Preparation of metallic pigments First, a 20 μm-thick polyethylene terephthalate (PET) film was coated with cellulose acetate butyrate resin (CAB) solubilized in acetone using a roll coater. After coating, the film was transported to an aluminum vacuum deposition machine at a speed of 5 m / s and 4 × 10 -3 Under a pressure of 10 kPa, an Al layer with a thickness of 17 nm or 28 nm was formed on the CAB / PET film. The prepared Al / CAB / PET film was immersed in an acetone bath and irradiated with ultrasonic waves of 40 kHz or less to peel the Al pigment from the PET film substrate. Next, after removing the acetone using a centrifuge, an appropriate amount of DEDG was added and ultrasonic waves of 40 kHz or less were irradiated and crushed. An appropriate amount of DEDG was added again to obtain a metallic pigment suspension containing flat Al particles at a concentration of 6%.

[0182] Next, FHP-2-OH (2-(perfluorohexyl)ethylphosphonic acid or 1H,1H,2H,2H-perfluorodecyltriethoxysilane) was added to the suspension containing the flat aluminum particles obtained as described above so that the mass ratio to the aluminum particles was the value shown in the table, and the mixture was surface-treated by irradiating it with ultrasonic waves of 40 kHz or less at a liquid temperature of 55°C for 3 hours. DisparBYK102 was then added and stirred to obtain a metallic pigment dispersion.

[0183] 2.2. Preparation of Ink Composition Each component was placed in a container so as to obtain the composition shown in Table 1, and mixed and stirred for 2 hours with a magnetic stirrer, and then filtered using a 5.0 μm PTFE membrane filter to obtain each of the metallic ink compositions (M1 to M6) and colored ink compositions (C1, C2). The values ​​in Table 1 indicate mass %. The mass of each ink composition was adjusted to 100 mass %.

[0184] [Table 1]

[0185] In Table 1, Al particles 1 were leaf-shaped particles with a thickness of 17 nm and a D50 of 0.5 μm. Al particles 2 were leaf-shaped particles with a thickness of 28 nm and a D50 of 0.7 μm. The fluorinated alkyl organophosphorus compound was FHP-2-OH (2-(perfluorohexyl)ethyl phosphonic acid) obtained from Unimatec Co., Ltd. The fluorinated alkylsilane compound was 1H,1H,2H,2H-perfluorodecyltriethoxysilane obtained from Sigma-Aldrich Co., Ltd. D50 is the volume average particle diameter, and was measured with a Microtrac MT-3300 (manufactured by Microtrac Bell Co., Ltd.). The thickness (average thickness) was measured by the method described above.

[0186] In Table 1, DEDG stands for diethylene glycol diethyl ether, MEDG stands for diethylene glycol methyl ethyl ether, and BTG-H stands for butyl triglycol. Represents.

[0187] DisparBYK102 is the trade name of a dispersant manufactured by BYK-Chemie, UC-3000 is an acrylic resin (fixing resin) manufactured by Toagosei Co., Ltd., and the vinyl chloride-vinyl acetate resin is a vinyl chloride-vinyl acetate copolymer manufactured by Nissin Chemical Industry Co., Ltd., trade name Solvine CL. The colorant PY155 used was CI Pigment Yellow 155. In addition, a 50% dispersant was used separately relative to the pigment, and was adjusted with the amount of DEDG.

[0188] 2.3.Evaluation Test 2.3.1. Recording tester A modified machine manufactured by Seiko Epson Corporation, SC-S606850, was used as a recording test machine. As shown in FIG. 1 in the detailed description above, an IR heater was provided between the recording head 12 that ejects the metallic ink composition and the recording head 14 that ejects the colored ink composition, with a gap of one head. The recording head had a nozzle density of 300 dpi. The recording head 12, the IR heater 50, and the recording head 14 were arranged in this order from the upstream side to the downstream side in the recording medium conveying direction and mounted on the same carriage. A serial type recording device was used. Recording was performed in four passes for each of the metallic ink and the colored ink.

[0189] In each example shown in Tables 2 and 3, the amount of the metallic ink composition adhered to the recording medium was 7.0 mg / inch 2 The amount of the color ink composition adhered to the recording medium was 3.5 mg / inch 2 The colored ink was printed on top of the metallic ink so as to obtain a yellow metallic image.

[0190] The surface temperature of the recording medium was set to the value shown in the table by heating with the IR heater, pre-heater, platen heater, and after-heater arranged as shown in Figure 1. In the table, the temperature in each heater column is the surface temperature (maximum temperature) of the part of the recording medium that was subjected to the heat when the temperature was confirmed by heating using only that one heater, and recording was performed by setting it to the temperature shown in the table. Therefore, if the recording medium is transported away from the position where it is subjected to heat, the temperature drops toward room temperature.

[0191] The recorded matter discharged from the printer was evaluated as follows: The recording medium was a polyvinyl chloride film, Scotchcal Graphics Film IJ8150 (manufactured by 3M).

[0192] 2.3.2. Evaluation of color mixing The color metallic images obtained in each example were visually evaluated for color mixing of the color inks attached onto the metallic ink layer. The evaluation was based on the following criteria, and the results are shown in Tables 2 and 3. A: It looks like a clear yellow metallic color. B: Looks like a slightly grayish metallic yellow color. C: Looks like a rather greyish yellow metallic color.

[0193] 2.3.3. Evaluation of gloss For each color metallic image obtained, a gloss meter (MINOLTA MULTI The gloss was measured at a tilt angle of 20° using a GLOSS 268. The results were evaluated according to the following criteria and are shown in Tables 2 and 3. A: Gloss measurement value is 600 or more. B: Gloss measurement value is 500 or more and less than 600. C: Gloss measurement value is 400 or more and less than 500. D: Gloss measurement less than 400.

[0194] 2.3.4. Evaluation of show-through In each example, a 10 cm x 10 cm pattern was continuously recorded on a roll-shaped recording medium at 1 cm intervals while the recording medium was being transported. After recording, the same type of recording medium was placed on top of the recording surface. A blocking tester (Tester Sangyo Co., Ltd. CO-201 permanent deformation tester) was used to measure the blocking strength of 5 kgf / cm 2 A load was applied to the recording medium. The recording medium was left for 10 hours at a temperature of 25°C and a humidity of 50% RH. After leaving the recording medium, the degree of adhesion between the recording mediums was checked. The results were evaluated according to the following criteria and are shown in Tables 2 and 3. A: It doesn't feel sticky. B: There is a feeling of adhesion, but no color transfer. C: There is color transfer, but the ink film is not peeled off. D: Peeling of the ink film is observed.

[0195] [Table 2]

[0196] [Table 3]

[0197] 2.4.Evaluation Results In each of the examples, which included a metallic ink application step, a heating step in which the metallic ink composition was heated by an IR heater, and a colored ink application step, excellent yellow metallic images with reduced color mixing were obtained. Furthermore, the gloss and prevention of show-through were also excellent. In contrast, in the comparative examples in which no IR heater was used, color mixing was noticeable.

[0198] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in the embodiments, or configurations that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0199] The following can be derived from the above-described embodiment and modified examples.

[0200] One aspect of the inkjet recording method is a metallic ink deposition step of ejecting a metallic ink composition containing a metallic pigment from an inkjet head and depositing the ink on a recording medium; a heating step of heating the metallic ink composition attached to the recording medium by an infrared heater; a color ink depositing step of ejecting a color ink composition containing a coloring material from an inkjet head and depositing the color ink composition on the recording medium; Equipped with The metallic ink composition and the colored ink composition are water-based inks or solvent-based inks.

[0201] According to this inkjet recording method, after the metallic ink application step, the heating step is performed by an IR heater. Therefore, leafing of the metallic pigment of the metallic ink composition progresses sufficiently, and an image having excellent metallic luster can be obtained. In addition, since the metallic ink composition dries well, color mixing is unlikely to occur even when a colored ink composition is applied, and a beautiful color metallic image can be obtained.

[0202] In the above-mentioned inkjet recording method, The metallic pigment may be a tabular particle.

[0203] According to this inkjet recording method, it is possible to obtain recorded matter having a better metallic luster.

[0204] In the above-mentioned inkjet recording method, The metallic ink composition and the colored ink composition may be solvent-based inks, each of which contains 40.0% by mass or more of a glycol ether-based solvent relative to the total amount of the composition.

[0205] According to this inkjet recording method, it is possible to obtain better recorded matter using solvent-based inks.

[0206] In the above-mentioned inkjet recording method, The metallic ink composition and the colored ink composition may each contain 40.0% by mass or more of a glycol ether solvent having a flash point of 70.0° C. or less, based on the total amount of the composition.

[0207] According to this ink jet recording method, it is possible to obtain better recorded matter using a solvent-based ink.

[0208] In the above-mentioned inkjet recording method, The metallic ink composition may contain an acrylic resin.

[0209] According to this inkjet recording method, an image with better fixability can be formed.

[0210] In the above-mentioned inkjet recording method, The metallic pigment may be surface-treated with a fluorine compound or a silane compound.

[0211] According to this ink jet recording method, it is possible to form an image with even better gloss.

[0212] In the above-mentioned inkjet recording method, The surface temperature of the recording medium in the heating step may be 30.0° C. or higher and 60.0° C. or lower.

[0213] According to this ink jet recording method, leafing of the attached metallic pigment is improved, so that an image with superior gloss can be obtained.

[0214] In the above-mentioned inkjet recording method, In the heating step, heating by a conductive heater may be further used.

[0215] According to this inkjet recording method, the drying speed of the metallic ink composition in the heating step is further increased, so that color mixing with the colored ink composition can be further suppressed.

[0216] In the above-mentioned inkjet recording method, After the color ink application step, a post-heating step may be carried out.

[0217] According to this inkjet recording method, show-through and rubbing after recording can be prevented more effectively.

[0218] In the above-mentioned inkjet recording method, The colored ink composition may be applied to the metallic ink composition heated in the heating step in the colored ink applying step.

[0219] According to this inkjet recording method, color mixing between the metallic ink composition and the colored ink composition can be further suppressed, and leafing of the metallic pigment can be further improved.

[0220] One aspect of the inkjet recording apparatus is an inkjet head that ejects the metallic ink composition; Infrared heater, an inkjet head that ejects the above-mentioned colored ink composition; Equipped with Recording is carried out by the above-mentioned ink jet recording method.

[0221] According to this inkjet recording apparatus, after the metallic ink is applied, the metallic ink composition is dried by an infrared heater, and then the colored ink composition is applied. In this case, the color ink composition is applied in a state in which the metallic ink composition is sufficiently dried, so that a color metallic image of good image quality in which color mixing of the metallic ink composition and the color ink composition is suppressed can be obtained. [Explanation of symbols]

[0222] 12, 14... recording head, 32... front cover, 34... rear cover, 40... transport roller, 50... IR heater, 51... heating element, 52... tube body, 53... support, 62... supply roll, 64... take-up roll, 71... housing, 72... guide, 82... pre-heater, 84... platen heater, 86... after-heater, 100... inkjet recording apparatus

Claims

1. a metallic ink deposition step of ejecting a metallic ink composition containing a metallic pigment from an inkjet head and depositing the ink onto a recording medium; a heating step of heating the metallic ink composition attached to the recording medium by an infrared heater; a color ink applying step of ejecting a color ink composition containing a color material from an inkjet head and applying it to the metallic ink composition on the recording medium; Equipped with the metallic ink composition contains an acrylic resin, the metallic ink composition and the colored ink composition are solvent-based inks, each containing a glycol ether-based solvent in an amount of 40.0% by mass or more relative to the total amount of the composition; the acrylic resin is dissolved in the metallic ink composition, which is a solvent-based ink; the inkjet head that ejects the metallic ink composition and the inkjet head that ejects the colored ink composition are mounted on a carriage, and the infrared heater is mounted on the carriage.

2. In claim 1, The ink jet recording method, wherein the metallic pigment is a tabular particle.

3. In claim 1 or claim 2, The inkjet recording method, wherein the metallic ink composition and the colored ink composition are solvent-based inks, each containing a glycol ether-based solvent in an amount of 50.0% by mass or more based on the total amount of the composition.

4. In claim 3, the metallic ink composition and the colored ink composition each contain 40.0% by mass or more of a glycol ether solvent having a flash point of 70.0°C or less, based on the total amount of the composition;

5. In any one of claims 1 to 4, The inkjet recording method, wherein the content of the acrylic resin in the metallic ink composition is 0.05% by mass or more and 15% by mass or less.

6. In any one of claims 1 to 5, The inkjet recording method, wherein the metallic pigment is surface-treated with a fluorine compound or a silane compound.

7. In any one of claims 1 to 6, The inkjet recording method, wherein the surface temperature of the recording medium in the heating step is 30.0°C or higher and 60.0°C or lower.

8. In any one of claims 1 to 7, An inkjet recording method, wherein the heating step further comprises heating with a conductive heater.

9. In any one of claims 1 to 8, An inkjet recording method, further comprising a post-heating step after the color ink applying step.

10. In any one of claims 1 to 9, an ink jet recording method, wherein the colored ink composition is applied to the metallic ink composition heated in the heating step in the colored ink applying step.

11. an inkjet head that ejects the metallic ink composition according to claim 1; Infrared heater and an inkjet head that ejects the colored ink composition according to any one of claims 1 to 10; Equipped with An inkjet recording apparatus that performs recording by the inkjet recording method according to any one of claims 1 to 10.

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