JP6168112B2 - Ink set, ink jet recording method and recorded matter - Google Patents

Description

  The present invention relates to an ink set, an ink jet recording method, and a recorded matter, and more particularly, to an ink set, an ink jet recording method, and a recorded matter capable of forming a coating film having a metallic luster.

  Conventionally, in order to form a coating film having a metallic luster on printed matter, gold powder made from brass, aluminum fine particles, etc., printing ink using silver powder as a pigment, foil press printing using metal foil, metal foil is used. The thermal transfer method that has been used is used.

  However, a coating film made of printing ink using gold powder or silver powder has a large average particle diameter of 10 to 30 μm, and a matte metallic luster is obtained, but it is difficult to obtain a mirror gloss. there were. Also, in foil stamping or thermal transfer using metal foil, an adhesive is applied to the print medium, a smooth metal foil is pressed onto the print medium, the recording medium and the metal foil are in close contact and heated, and the metal foil and the recording medium are thermally melted. Take the method of wearing. For this reason, relatively good gloss can be obtained, but since the number of manufacturing processes increases and pressure and heat are applied during the manufacturing processes, there is a limitation that the recording medium is limited to recording media that are resistant to heat and deformation.

  In recent years, many applications of inkjet in printing have been seen, and one of the applications is metallic printing. For example, Japanese Patent Laid-Open No. 2002-179960 discloses a technique in which a metal film is formed on the surface of plastic spherical particles, and an ink composition containing the pigment is subjected to a printing process by ink jet printing (Patent Document 1). ). However, in order to obtain a high metallic luster, it is necessary to deform and flatten the sphere and smooth the surface. In this technique, it is said that it is necessary to simultaneously perform the press treatment with a roller and the heat treatment. Therefore, it is inevitable that the apparatus and the manufacturing process are complicated in this respect, and the recording medium is also limited.

  Japanese Patent Laid-Open No. 2003-292836 also discloses a technique using an ink composition in which a precious metal colloid such as gold or silver is dispersed (Patent Documents 2 and 3). However, when the noble metal colloid is prioritized in dispersion stability and the particle diameter is reduced to several nanometers to several tens of nanometers, color development derived from plasmon absorption appears, and a metallic luster cannot be obtained as an ink composition. In this case, after the coating film is dried, a metallic luster is obtained by fusing the colloidal particles by heat treatment at 150 ° C. or higher. When the particle size is increased in favor of metallic luster, the dispersion stability is lowered, the problem of aggregation and sedimentation cannot be avoided, and the shelf life of the ink composition is remarkably reduced. Further, it is obvious that using a noble metal as a material greatly increases the cost of the ink composition, and therefore can only be used for high value-added applications, which is disadvantageous in terms of cost.

  A conventional metallic ink composition has a method in which a metal pigment and a color material are mixed and used as a single ink composition. In this method, an ink composition in which the metal pigment and the color material are separated when printed. There is a problem that only the metal pigment settles and aggregates during storage of the object, and only the color material is absorbed in the recording medium, and only the metal pigment remains on the surface. It was the cause of printing failure.

JP 2002-179960 A Japanese Patent Laid-Open No. 2003-292836 JP 2003-306625 A

  The present invention focuses on aluminum as a relatively inexpensive metal material, and forms a coating film having a metallic luster of an arbitrary color tone on a printed matter by forming an ink set including an ink composition having a high metallic mirror gloss. An object of the present invention is to provide an ink set that can be used.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive studies. As a result, due to metal pigment dispersions, ink compositions, ink jet recording methods and recorded materials using specific metal pigments, it has been impossible in the past. It was found that a printed matter having a high specular gloss was obtained. The present invention has been made on the basis of such knowledge, and provides the following inventions.

  [1] At least one selected from the group consisting of an oil-based ink composition containing a metal pigment, a chromatic ink composition containing a chromatic pigment, a black ink composition containing a black pigment, and a white ink composition containing a white pigment An ink set comprising at least one kind of oil-based ink composition.

  Preferred embodiments of the invention are as follows. [2] When the metal pigment is a tabular grain and the major axis on the plane of the tabular grain is X, the minor axis is Y, and the thickness is Z, the area of the tabular grain in the XY plane The ink set according to [1], wherein the 50% average particle diameter R50 of the obtained equivalent circle diameter is 0.5 to 3 μm and the metal pigment satisfies the condition of R50 / Z> 5. [3] The ink set according to [1] or [2], wherein the metal pigment is aluminum or an aluminum alloy; [4] the metal pigment is prepared by crushing a metal vapor-deposited film. [1] The ink set according to any one of [3]; [5] The oil-based ink composition containing the metal pigment contains the metal pigment, an organic solvent, and a resin. [6] The ink set according to any one of [4]; [6] Any one of [1] to [5], wherein the pigment concentration of the oil-based ink composition is 0.1 to 10.0% by weight. [7] The ink set according to [5] or [6], wherein the organic solvent contains one or more alkylene glycol ethers that are liquid at normal temperature and pressure; [8] The organic solvent is , Alkylene glycol diether, alkylene glycol [9] The ink set according to [5] or [6], wherein the resin is polyvinyl butyral, cellulose acetate butyrate, polyacryl polyol, polyurethane, vinyl chloride-vinyl acetate copolymer And / or the ink set according to any one of [5] to [8], which is at least one selected from the group consisting of resin emulsions thereof; [10] The oil-based ink composition is at least 1 The ink set according to any one of [5] to [9], comprising at least one kind of acetylene glycol-based and / or silicone-based surfactant; [11] The chromatic pigment is an organic pigment, and the black pigment Is carbon black and the white pigment is titanium dioxide and / or a hollow resin emulsion [1] [10] In the ink set according to any one of [10]; [12] In an ink jet recording method for performing recording by discharging a droplet of an ink composition and attaching the droplet to a recording medium, [1] to [11] ] An ink jet recording method for forming an image using the ink set according to any one of the above; [13] An oil-based ink composition containing the metal pigment, the chromatic ink composition, the black ink composition, An inkjet recording method according to [12], wherein at least one selected from the group consisting of white ink compositions is simultaneously ejected to form an image; [14] An oil-based ink composition containing the metal pigment; [15] The inkjet recording method according to [12], wherein an image having an arbitrary color tone is formed using the chromatic color ink composition after forming an image by using the chromatic color ink composition; After forming an image using the oil-based ink composition, an image having an arbitrary color tone is formed using the chromatic ink composition, and then an image is formed using the black ink composition and / or the white ink pigment. The inkjet recording method according to [12]; [16] The inkjet recording method according to any one of [12] to [15], wherein the method of discharging the ink composition is a non-heating method; 17] The inkjet recording method according to any one of [12] to [16], wherein the recording medium is heated and printed; [18] The heating temperature is from 30 ° C to 80 ° C. [19] The inkjet recording method according to [18], wherein the heating is performed before and / or simultaneously with printing and / or after printing; [20] [12] to [19] ] Recorded matter recorded by the inkjet recording method according to any one of 1).

  According to the ink set, ink jet recording method and recorded matter of the present invention, by using an ink composition containing a metal pigment, an image having a high metallic gloss (so-called metallic gloss) can be formed on a recording medium. Furthermore, by combining the chromatic color ink composition, the black ink composition, and the white ink composition to constitute an ink set, an image that cannot be realized by a conventional ink set, that is, an image having a metallic luster of an arbitrary color tone. Can be formed.

[Ink set]
As described above, the ink set of the present embodiment includes an oil-based ink composition containing a metal pigment, a chromatic color ink composition containing a chromatic color pigment, a black ink composition containing a black pigment, and a white ink composition containing a white pigment. And at least one oil-based ink composition selected from the group consisting of materials. This makes it possible to form an image in which a metallic luster is added to the color tone of the chromatic pigment, black pigment, and white pigment.

  The metal pigment (also referred to as a metallic pigment) is a tabular grain. When the major axis on the plane of the tabular grain is X, the minor axis is Y, and the thickness is Z, the XY plane of the tabular grain is X-Y plane. It is preferable that the 50% average particle diameter R50 of the equivalent-circle diameter calculated | required from the area of is 0.5-3 micrometers, and is a metal pigment which satisfy | fills the conditions of R50 / Z> 5.

  A “tabular grain” refers to a grain having a substantially flat surface (XY plane) and a substantially uniform thickness (Z). Since the plate-like particles are prepared by crushing a metal vapor-deposited film, metal particles having a substantially flat surface and a substantially uniform thickness can be obtained. Therefore, the major axis on the plane of the tabular grains can be defined as X, the minor axis as Y, and the thickness as Z.

  “Equivalent circle diameter” is the diameter of the circle when assuming that the substantially flat surface (XY plane) of the tabular particles of the metallic pigment is a circle having the same projected area as the projected area of the particles of the metallic pigment. It is. For example, when the substantially flat surface (XY plane) of the tabular grain of the metallic pigment is a polygon, the diameter of the circle obtained by converting the projected surface of the polygon into a circle is calculated by using the diameter of the metallic pigment. It is called the equivalent-circle diameter of a tabular grain.

  The 50% average particle diameter R50 of the equivalent circle diameter determined from the area of the XY plane of the tabular grains is more preferably 0.5 to 3 μm from the viewpoint of metallic luster and printing stability, and is preferably 0.75 to 0.75. More preferably, it is 2 μm.

  Further, in terms of the relationship between the 50% average particle diameter R50 of the equivalent circle diameter and the thickness Z, it is preferable that R50 / Z> 5 from the viewpoint of securing a high metallic luster.

  The metallic pigment is preferably aluminum or an aluminum alloy from the viewpoint of cost and ensuring a metallic luster. When an aluminum alloy is used, another metal element or non-metal element that can be added to aluminum is not particularly limited as long as it has a metallic luster, but silver, gold, platinum, nickel, chromium, tin Zinc, indium, titanium, copper and the like, and at least one of these simple substances or alloys thereof and mixtures thereof is preferably used.

  The method for producing the metallic pigment includes, for example, the metal or alloy layer of the composite pigment base material and the release resin having a structure in which a release resin layer and a metal or alloy layer are sequentially laminated on a sheet-like substrate surface. Tabular grains are obtained by peeling off from the sheet-like substrate, crushing and refining at the boundary of the layers. And when the major axis on the plane of the obtained tabular grains is X, the minor axis is Y, and the thickness is Z, 50% average grains of the equivalent circle diameter determined from the area of the XY plane of the tabular grains A material having a diameter R50 of 0.5 to 3 μm and a condition satisfying R50 / Z> 5 is collected.

  The major axis X, minor axis Y, and equivalent circle diameter on the plane of the metallic pigment (tabular particles) can be measured using a particle image analyzer. As the particle image analyzer, for example, flow type particle image analyzers FPIA-2100, FPIA-3000, and FPIA-3000S manufactured by Sysmex Corporation can be used.

  The metal or alloy layer is preferably formed by vacuum deposition, ion plating or sputtering.

  The metal or alloy layer has a thickness of 20 nm to 100 nm. Thereby, a pigment having an average thickness of 20 nm to 100 nm is obtained. By setting it to 20 nm or more, it is excellent in reflectivity and glitter, and the performance as a metallic pigment is enhanced. By setting it to 100 nm or less, increase in apparent specific gravity can be suppressed and dispersion stability of the metallic pigment can be secured. .

  The release resin layer in the composite pigment raw material is an undercoat layer of the metal or alloy layer, but is a peelable layer for improving the peelability from the sheet-like substrate surface. As the resin used for the peeling resin layer, for example, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polyacrylic acid, polyacrylamide, cellulose derivative, polyvinyl butyral, acrylic acid polymer, or modified nylon resin is preferable.

  A layer is formed by applying a solution of one or a mixture of the above to a recording medium and drying. After coating, additives such as a viscosity modifier can be contained.

  The release resin layer is applied by generally used gravure coating, roll coating, blade coating, extrusion coating, dip coating, spin coating, or the like. After coating and drying, the surface is smoothed by calendaring if necessary.

  Although the thickness of the resin layer for peeling is not specifically limited, 0.5-50 micrometers is preferable, More preferably, it is 1-10 micrometers. If it is less than 0.5 μm, the amount as a dispersion resin is insufficient, and if it exceeds 50 μm, when it is rolled, it tends to peel off at the interface with the pigment layer.

  The sheet-like substrate is not particularly limited, but may be a polyester film such as polytetrafluoroethylene, polyethylene, polypropylene, or polyethylene terephthalate, a polyamide film such as 66 nylon or 6 nylon, a polycarbonate film, a triacetate film, a polyimide film, or the like. An example is a moldable film. A preferable sheet-like substrate is polyethylene terephthalate or a copolymer thereof.

Although the thickness of these sheet-like base materials is not specifically limited, 10-150 micrometers is preferable.
If it is 10 μm or more, there is no problem in handleability in the process or the like, and if it is 150 μm or less, it is rich in flexibility and there is no problem in roll formation, peeling and the like.

  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 silicon oxide layer and a protective resin layer.

  The silicon 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.

  An alcohol solution in which the silicon alkoxide or a polymer thereof is dissolved is applied and heated and fired to form a silicon oxide layer coating film.

  The protective resin layer is not particularly limited as long as it is a resin that does not dissolve in the dispersion medium, and examples thereof include polyvinyl alcohol, polyethylene glycol, polyacrylic acid, polyacrylamide, and cellulose derivatives. Or it is preferable to form from a cellulose derivative.

  A layer obtained by applying an aqueous solution of one or a mixture of two or more of the above resins and performing drying or the like is formed. The coating solution can contain additives such as a viscosity modifier.

  The silicon oxide and the resin are applied by the same method as the application of the release resin layer.

  Although the thickness of the said protective layer is not specifically limited, The range of 50-150 nm is preferable. If it is less than 50 nm, the mechanical strength is insufficient, and if it exceeds 150 nm, the strength becomes too high, so that pulverization / dispersion becomes difficult, and peeling may occur at the interface with the metal or alloy layer.

  Further, a color material layer may be provided between the “protective layer” and the “metal or alloy layer”.

  The color material layer is introduced to obtain an arbitrary colored composite pigment, and can contain a color material capable of imparting an arbitrary color tone and hue in addition to the metallic luster and glitter of the metallic pigment used in the present invention. If it is, it will not specifically limit. The color material used for the color material layer may be either a dye or a pigment. Moreover, as a dye and a pigment, a well-known thing can be used suitably.

  In this case, the “pigment” used in the color material layer means a natural pigment, a synthetic organic pigment, a synthetic inorganic pigment or the like defined in the field of general pigment chemistry. This is different from that processed into a laminated structure.

  A method for forming the color material layer is not particularly limited, but it is preferable to form the color material layer by coating.

  Further, when the color material used in the color material layer is a pigment, it is preferable to further include a color material dispersion resin. Examples of the color material dispersion resin include a pigment, a color material dispersion resin, and other materials as necessary. It is preferable to form a resin thin film by dispersing or dissolving the additive in a solvent and forming a uniform liquid film by coating as a solution and then drying.

  In the production of the composite pigment base material, it is preferable in terms of work efficiency that both the colorant layer and the protective layer are formed by coating.

  As the composite pigment base material, a layer structure having a plurality of sequentially laminated structures of the release resin layer and a metal or alloy layer is also possible. At that time, the total thickness of the laminated structure composed of a plurality of metal or alloy layers, that is, the metal or alloy layer excluding the sheet-like base material and the exfoliating resin layer immediately above it-exfoliating resin layer-metal or alloy layer Alternatively, the thickness of the release resin layer-metal or alloy layer is preferably 5000 nm or less. When it is 5000 nm or less, even when the composite pigment base material is rolled up, it is difficult to cause cracking and peeling and is excellent in storage stability. In addition, when pigmented, it is excellent in glitter and preferable.

  Moreover, although the structure where the resin layer for peeling and the metal or alloy layer were laminated | stacked in order on both surfaces of the sheet-like base material surface is mentioned, it is not limited to these.

  The peeling treatment method from the sheet-like substrate is not particularly limited, but is a method that is performed by immersing the composite pigment raw material in a liquid, or ultrasonic treatment is performed at the same time as the immersion in the liquid. A method of pulverizing the composite pigment separated from the treatment is preferred.

  In the pigment obtained as described above, the release resin layer has a role of a protective colloid, and a stable dispersion can be obtained only by performing a dispersion treatment in a solvent. In the ink composition using the pigment, the resin derived from the release resin layer also has a function of imparting adhesiveness to a recording medium such as paper.

  The oil-based ink composition used in the ink set of the present embodiment contains the above-described metallic pigment, an organic solvent, and a resin.

  The concentration of the metallic pigment in the ink composition is preferably 0.1 to 10.0% by weight.

  When the concentration of the metallic pigment in the ink composition is 0.1% by weight or more and less than 1.5% by weight, a glossy surface like a half mirror is obtained by ejecting an amount of ink that cannot sufficiently cover the printing surface, Although a feeling of gloss can be felt, it is possible to print a texture that allows the background to show through, and a high gloss metallic glossy surface can be formed by discharging a sufficient amount of ink to cover the printing surface. Therefore, for example, it is suitable for forming a half mirror image on a transparent recording medium or for expressing a highly glossy metallic glossy surface. Further, when the concentration of the metallic pigment in the ink composition is 1.5% by weight or more and 3.0% by weight or less, the metallic pigment is randomly arranged on the printing surface, so that high gloss cannot be obtained and the matte tone is obtained. A metallic gloss surface can be formed. Therefore, for example, it is suitable for forming a shielding layer on a transparent recording medium.

  The organic solvent is preferably a polar organic solvent such as alcohols (for example, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, isopropyl alcohol, or fluorinated alcohol), ketones (for example, acetone, methyl ethyl ketone, Or cyclohexanone), carboxylic acid esters (eg, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, or ethyl propionate), or ethers (eg, diethyl ether, dipropyl ether, tetrahydrofuran, Alternatively, dioxane or the like can be used.

  In particular, the organic solvent preferably contains one or more alkylene glycol ethers that are liquid at normal temperature and pressure.

  Alkylene glycol ethers are ethylene glycols based on methyl, n-propyl, i-propyl, n-butyl, i-butyl, hexyl and 2-ethylhexyl aliphatic, allyl with double bonds and phenyl groups. Ether and propylene glycol ether, colorless and odorless, with ether and hydroxyl groups in the molecule, so it is liquid at room temperature with both alcohol and ether properties . Moreover, there are a monoether type in which only one hydroxyl group is substituted and a diether type in which both hydroxyl groups are substituted, and these can be used in combination.

  In particular, the organic solvent is preferably a mixture of alkylene glycol diether, alkylene glycol monoether, and lactone.

  As alkylene glycol monoether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, Diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol Over monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether and the like.

  Examples of the alkylene glycol diether include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, tetra Ethylene 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, etc. It is below.

  Examples of the lactone include γ-butyrolactone, δ-valerolactone, and ε-caprolactone.

  By setting it as such a suitable structure, the objective of this invention can be achieved further.

  Examples of the resin used in the oil-based ink composition include acrylic resin, styrene-acrylic resin, rosin-modified resin, terpene resin, polyester resin, polyamide resin, epoxy resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer. Examples include coalescence, fiber-based resin (for example, cellulose acetate butyrate, hydroxypropyl cellulose), polyvinyl butyral, polyacryl polyol, polyvinyl alcohol, polyurethane and the like.

  Non-aqueous emulsion type polymer fine particles (NAD = Non Aqueous Dispersion) can also be used as the resin. This is a dispersion in which fine particles such as a polyurethane resin, an acrylic resin, and an acrylic polyol resin are stably dispersed in an organic solvent. Examples of polyurethane resins include “Samprene IB-501” and “Samprene IB-F370” manufactured by Sanyo Chemical Industries, Ltd., and acrylic polyol resins include “N-2043-60MEX” and “N” manufactured by Harima Chemical Co., Ltd. -2043-AF-1 "and the like.

  The resin emulsion is preferably added in an amount of 0.1% by weight to 10% by weight in the ink composition in order to further improve the fixability of the pigment to the recording medium. If the addition amount is excessive, the printing stability cannot be obtained, and if it is too small, the fixing property is insufficient.

  The ink composition preferably contains at least one glycerin, polyalkylene glycol, or saccharide. The total amount of the one or more kinds of glycerin, polyalkylene glycol, or saccharide is preferably added in the ink composition in the range of 0.1 wt% to 10 wt%.

  With such a preferable configuration, it is possible to stabilize ink discharge and improve the image quality of the recorded matter while suppressing drying of the ink and preventing clogging.

  The polyalkylene glycol is a linear polymer compound having a repeating structure of an ether bond in the main chain, and is produced, for example, by ring-opening polymerization of a cyclic ether.

  Specific examples of the polyalkylene glycol include polymers such as polyethylene glycol and polypropylene glycol, ethylene oxide-propylene oxide copolymers and derivatives thereof. As the copolymer, any copolymer such as a random copolymer, a block copolymer, a graft copolymer, and an alternating copolymer can be used.

  Preferable specific examples of the polyalkylene glycol include those represented by the following formula.

_{HO- (CnH 2 nO) m-} H
(In the above formula, n represents an integer of 1 to 5, and m represents an integer of 1 to 100).

In the above formula, (CnH ₂ nO) m may be a constant or a combination of two or more numbers within the range of the integer value n. For example, when n is 3, it is (C ₃ H ₆ O) m, and when n is a combination of 1 and 4, it is (CH ₂ O—C ₄ H ₈ O) m. Further, the integer value m may be one constant or a combination of two or more numbers within the range. For example, in the above example, when m is a combination of 20 and 40, it is (CH ₂ O) _20- (C ₂ H ₄ O) ₄₀ , and when m is a combination of 10 and 30, (CH ₂ O ) ₁₀ - (a C ₄ H ₈ O) _30. Further, the integer values n and m may be arbitrarily combined within the above range.

  Examples of the saccharide include monosaccharides such as pentose, hexose, heptose, and octose; polysaccharides such as disaccharides, trisaccharides, and tetrasaccharides; or sugar derivatives that are derivatives thereof, reduced derivatives such as deoxyacids, aldonic acid, and uronic acid. Examples include oxidized derivatives, dehydrated derivatives such as glycosene, amino acids, thiosugars, and the like. Polysaccharides refer to sugars in a broad sense and include substances that exist widely in nature, such as alginic acid, dextrin, and cellulose.

  The oil-based ink composition preferably contains at least one acetylene glycol surfactant and / or silicone surfactant. The surfactant is preferably added in an amount of 0.01% by weight to 10% by weight with respect to the pigment content in the ink composition.

  By adopting such a suitable configuration, the wettability of the oil-based ink composition to the recording medium can be improved, and quick fixability can be obtained.

  Examples of the acetylene glycol surfactant include Surfynol 465 (trademark), Surfynol 104 (trademark) (trade name, manufactured by Air Products and Chemicals, Inc.), Olfin STG (trademark), Olfine E1010 (trademark) ( As mentioned above, trade names, manufactured by Nissin Chemical Co., Ltd.) and the like are preferable.

  As the silicone surfactant, polyester-modified silicone or polyether-modified silicone is preferably used. Specific examples include BYK-347, BYK-348, BYK-UV3500, BYK-UV3510, BYK-UV3530, BYK-UV3570 (Bicchemy Japan Co., Ltd.).

  The oil-based ink composition can be prepared by a known conventional method. For example, first, after mixing the metallic pigment, the dispersant, and the liquid medium described above, a pigment dispersion is prepared by a ball mill, a bead mill, an ultrasonic wave, a jet mill, or the like, and adjusted to have desired ink characteristics. To do. Subsequently, a binder resin, the liquid medium, and other additives (for example, a dispersion aid or a viscosity modifier) can be added with stirring to obtain a pigment ink composition.

  In addition, the composite pigment base may be sonicated in a liquid medium once to obtain a composite pigment dispersion, and then mixed with the necessary ink liquid medium. The ink composition may be directly subjected to ultrasonic treatment in an ink medium.

  The physical properties of the oil-based ink composition are not particularly limited. For example, the surface tension is preferably 20 to 50 mN / m. If the surface tension is less than 20 mN / m, the ink composition may spread or ooze out on the surface of the ink jet recording printer head, making it difficult to eject ink droplets. The surface tension is 50 mN / m. If it exceeds 1, the surface of the recording medium will not spread and good printing may not be possible.

  Next, the chromatic ink composition, black ink composition, and white ink composition used in the ink set of this embodiment will be described.

  The chromatic ink composition is an ink composition containing a chromatic pigment. “Chromatic colors” refers to all colors other than a series of colors (achromatic colors) ranging from white to gray to black. The chromatic pigment is preferably an organic pigment from the viewpoint of storage stability such as light resistance, weather resistance, and gas resistance.

  Specifically, insoluble azo pigments, condensed azo pigments, azo lakes such as azo lakes and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments, etc. Polycyclic pigments, dye chelates (eg basic dye chelates, acid dye chelates, etc.), dye rakes (basic dye rakes, acid dye rakes), nitro pigments, nitroso pigments, aniline black, daylight Examples thereof include fluorescent pigments. The above pigments can be used alone or in combination of two or more. More specifically, for example, C.I. I. 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, 129, 138, 139, 150, 153, 154, 155, 180, 185, 213, C.I. I. 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 rake), 83, 88, 101 (Bengara), 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, C.I. I. Pigment violet 19, C.I. I. 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, C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18, 36, etc. can be used.

  Any pigment that is not described in the color index can be used as long as it is insoluble in water.

  The black ink composition is an ink composition containing a black pigment. Examples of black pigments include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper oxide, iron oxide (CI pigment black 11), etc. Examples thereof include organic pigments such as metals and aniline black (CI Pigment Black 1), but carbon black having a relatively low specific gravity and difficult to settle in water is preferred for inkjet use. You may use these as 1 type or a 2 types of mixture.

  The white ink composition is an ink composition containing a white pigment. Examples of white pigments include Group IV element oxides such as titanium dioxide and zirconia dioxide. In addition, calcium carbonate, calcium sulfate, zinc oxide, barium sulfate, barium carbonate, silica, alumina, kaolin, clay, talc, clay, aluminum hydroxide, magnesium carbonate, white hollow resin emulsion, etc. are preferable, preferably these It is a 1 type, or 2 or more types of mixture selected from the group which consists of.

  The hollow resin emulsion is an oily dispersion containing hollow polymer fine particles, and the hollow polymer fine particles are composed of a plurality of fine particle subgroups, and the fine particle subgroups adjacent to each other in terms of the average particle size. An oil-based dispersion having an average particle size difference of less than 100 nm.

  From the viewpoint of whiteness, the primary particle diameter of the white pigment is preferably less than 1 · 壕.

  Here, the “primary particle diameter” refers to the size of a particle formed by collecting single crystals or crystallites close thereto. The primary particle size of the pigment is measured by electron microscopy. This is to measure the size of pigment particles from an electron micrograph, and is more reliable by dispersing the pigment in an organic solvent, fixing it to a support film, and performing image processing and measurement from a transmission electron micrograph. The value can be determined. Specifically, the minor axis diameter and the major axis diameter of each primary particle diameter are measured, and the diameter of a circle equal to the area is arithmetically determined as the primary particle diameter, and 50 or more pigments from a fixed visual field. Particles are randomly selected and an average value is obtained. Other measurement methods can be used as long as the same reliability can be obtained, but when there is a substantial difference in numerical values, the value obtained by the above method is adopted.

  The chromatic color ink composition and the black ink composition may be appropriately determined, but are 0.1 to 30% by weight, preferably 0.5 to 12% by weight in the ink composition. The content of the pigment in the white ink composition is preferably 1.0% by weight or more, more preferably 5.0% by weight or more, still more preferably 10% by weight or more and 20% by weight or less from the viewpoint of whiteness. .

  The ink composition used in the ink set of the present embodiment preferably uses a pigment as a colorant and contains a dispersant for dispersing the pigment. As the dispersant, those that can be used for this kind of pigment ink can be used without particular limitation, and examples thereof include a cationic dispersant, an anionic dispersant, a nonionic dispersant, and a surfactant.

  Examples of anionic dispersants include polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid. Copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid-alkyl acrylate copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-α-methylstyrene-acrylic acid copolymer Styrene-α-methylstyrene-acrylic acid-alkyl acrylate copolymer, styrene-maleic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene Copolymer, vinyl acetate-maleic ester Examples include copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and the like.

  Nonionic dispersants include polyvinyl pyrrolidone, polypropylene glycol, vinyl pyrrolidone-vinyl acetate copolymer, and the like.

  Surfactants as dispersants include anionic surfactants such as sodium dodecylbenzenesulfonate, sodium laurate, ammonium salt of polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkyl ester Nonionic surfactants such as oxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, and the like. In particular, it is preferable to use a styrene- (meth) acrylic acid copolymer from the viewpoint of enhancing the dispersion stability of the pigment.

  The oil-based ink composition used in the present embodiment can further contain other additives contained in a normal oil-based ink composition. Examples of such additives include stabilizers (for example, antioxidants or ultraviolet absorbers).

  As the antioxidant, for example, BHA (2,3-butyl-4-oxyanisole) or BHT (2,6-di-t-butyl-p-cresol) can be used, and as an ultraviolet absorber, For example, a benzophenone compound or a benzotriazole compound can be used.

The above oil-based ink composition can be prepared by a known conventional method. For example, when a pigment is used as a coloring material, a pigment, a dispersant, and a mixture (part) of the diethylene glycol compound and the dipropylene glycol compound are first mixed, and then a ball mill, a bead mill, an ultrasonic wave, or a jet mill. The pigment dispersion is prepared by adjusting the ink properties to have desired ink characteristics. Subsequently, a binder resin, a mixture (remaining amount) of the diethylene glycol compound and the dipropylene glycol compound, and other additives (for example, a dispersion aid or a viscosity modifier) are added with stirring to obtain an oil-based pigment ink composition. Can be obtained.
Alternatively, an oil-based ink composition can be obtained by using a pigment and a dye in combination as a color material and by a method similar to the method for preparing the oil-based pigment ink composition.

[Inkjet recording method]
The ink jet recording method of this embodiment is an ink jet recording method in which an ink jet head is driven to eject ink composition droplets, and the ink droplets are attached to a recording medium to perform recording. An image is formed.

  When the oil-based ink composition containing the above-described metal pigment is used alone, the measured values of 20 °, 60 °, and 85 ° specular gloss specified in JIS Z8741 are values of 200, 200, 100 or more at the same time, respectively. It is possible to form an image having a metallic luster. By using this oil-based ink composition, it is possible to form an image having a desired metallic luster from a matte image to a glossy image.

  Specifically, when images having 20, 60, and 85 degree specular gloss values of 200 to less than 400, 200 to less than 400, and 100 or more as defined in JIS Z8741 are formed at the same time. An image having a matte tone (matte tone) metallic luster can be obtained.

  In addition, images with measured values of 20 °, 60 °, and 85 ° specular gloss specified by JIS Z8741 that are simultaneously 400 or more and less than 600, 400 or more and less than 600, and 100 or more are reflected in the formed image. It is possible to obtain a glossy metallic luster so that the indented object can be slightly discriminated.

  Furthermore, images having a metallic luster in which the measured values of 20 °, 60 °, and 85 ° specular gloss specified in JIS Z8741 are simultaneously 600 or more, 600 or more, and 100 or more have sharpness. Further, it is possible to obtain a metallic luster having a so-called “mirror gloss” so that an object reflected in the formed image can be clearly discriminated.

  The oil-based ink composition containing a metal pigment and the oil-based ink composition comprising the chromatic ink composition, the black ink composition, and the white ink composition can be simultaneously ejected to form an image. As a result, a metallic color tone can be imparted to the color tone of the chromatic pigment, black pigment, and white pigment.

  When the oil-based ink composition containing the metal pigment and the oil-based ink composition such as the chromatic color ink composition, the black ink composition, and the white ink composition are separately ejected, for example, the metal pigment is used. It is preferable to form an image using the chromatic color ink composition after forming an image having metallic luster using the oil-based ink composition. The metallic pigment hardly penetrates into the ink receiving layer regardless of whether or not the recording medium has the ink receiving layer, and is attached to the recording medium. On the other hand, when the pigment contained in the chromatic ink composition is ejected onto a recording medium having an ink receiving layer, it easily penetrates into the ink receiving layer. For this reason, when an oil-based ink composition containing a metal pigment is first ejected to form an adhesion layer of a metallic pigment on a recording medium and a pigment of a chromatic ink is adhered thereon, the pigment of the chromatic ink composition It becomes possible to develop colors more vividly.

  Further, after forming an image having metallic luster using the oil-based ink composition containing the metal pigment, an image having metallic luster of any color tone is formed using the chromatic color ink composition, and then the black ink An image can also be formed using the composition and / or a white ink pigment.

  Examples of the method for discharging the ink composition include the methods described below.

  As a first method, there is an electrostatic suction method, in which a strong electric field is applied between the nozzle and the acceleration electrode placed in front of the nozzle, and ink is continuously ejected from the nozzle in the form of droplets. This is a method in which a print information signal is applied to the deflection electrode while the ink droplet is flying between the deflection electrodes and recorded, or a method in which the ink droplet is ejected in response to the print information signal without being deflected.

  The second method is a method in which ink droplets are forcibly ejected by applying pressure to the ink liquid with a small pump and mechanically vibrating the nozzle with a crystal resonator or the like. The ejected ink droplet is charged simultaneously with the ejection, and a printing information signal is given to the deflection electrode and recorded while the ink droplet flies between the deflection electrodes.

  The third method is a method using a piezoelectric element (piezo element), in which pressure and a print information signal are simultaneously applied to an ink liquid by a piezoelectric element to eject and record ink droplets.

  The fourth method is a method in which the ink liquid is rapidly expanded in volume by the action of heat energy, and the ink liquid is heated and bubbled by a microelectrode in accordance with a print information signal to eject and record ink droplets.

  Any of the above methods can be used in the ink jet recording method of the present embodiment, but from the viewpoint of high-speed printing, the method of discharging the ink composition is preferably a non-heating method. That is, it is preferable to employ the first method, the second method, or the third method.

  There are no particular restrictions on the recording medium. For example, plain paper, inkjet paper (matte paper, glossy paper), plastic films such as glass and PVC, films with a plastic or receiving layer coated on a substrate, metal, printed wiring Various recording media such as a substrate 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 by heating the recording medium from the viewpoint of increasing the drying speed and obtaining high gloss.

  Heating is performed without bringing the recording medium into contact with the recording medium, such as heating by bringing a heat source into contact with the recording medium, irradiating infrared rays or microwaves (electromagnetic waves having a maximum wavelength of about 2,450 MHz), or blowing hot air. The method etc. are mentioned.

  The heating is preferably performed before printing and / or simultaneously with printing and / or after printing. In other words, the recording medium may be heated before printing, simultaneously, or after printing, and may be heated throughout printing. The heating temperature depends on the type of the recording medium, but is preferably 30 to 80 ° C, more preferably 40 to 60 ° C.

[Recordings]
The recorded matter of this embodiment is recorded by the above-described ink jet recording method using the ink set described above. Since this recorded matter was obtained by the above-described ink jet recording method using the above-described ink set, a recorded matter having a metallic tone image having an arbitrary color tone can be obtained.

〔Example〕
1. Metallic Ink Composition (1) Preparation of Metallic Pigment Dispersion Film Thickness 100 / High PET PET Film, Cellulose Acetate Butyrate (Butylation Rate 35-39%, Kanto Chemical Co., Ltd.) 3.0% by Weight and Diethylene Glycol Diethyl A resin layer coating solution comprising 97% by weight of ether (manufactured by Nippon Emulsifier Co., Ltd.) was uniformly applied by a bar coating method, and dried at 60 ° C. for 10 minutes to form a resin layer thin film on the PET film.

  Next, the aluminum vapor deposition layer with an average film thickness of 20 nm was formed on said resin layer using the vacuum vapor deposition apparatus (VE-1010 type vacuum vapor deposition apparatus by a vacuum device company).

  Next, the laminate formed by the above method is simultaneously peeled, refined, and dispersed in diethylene glycol diethyl ether using a VS-150 ultrasonic disperser (manufactured by ASONE), and integrated ultrasonic dispersion treatment. A metallic pigment dispersion having a time of 12 hours was prepared.

  The obtained metallic pigment dispersion was filtered with a SUS mesh filter having an opening of 5 μm to remove coarse particles. Subsequently, the filtrate was put into a round bottom flask, and diethylene glycol diethyl ether was distilled off using a rotary evaporator. Thereby, the metallic pigment dispersion was concentrated, and then the concentration of the metallic pigment dispersion was adjusted to obtain a metallic pigment dispersion 1 having a concentration of 5% by weight.

  In addition, metallic pigment dispersions 2 and 3 having metallic pigments with varying deposition conditions and / or ultrasonic dispersion time were obtained.

  Then, using a particle diameter / particle size distribution measuring apparatus (FPIA-3000S manufactured by Sysmex Corporation), 50% average particle diameter R50 of the equivalent diameter of the major axis (X direction) -minor axis (Y direction) plane of each metallic pigment, The average film thickness Z was measured, and R50 / Z was calculated based on the measured values of R50 and Z obtained. The results are shown in Table 1.

(2) Preparation of metallic ink composition Metallic pigment ink compositions having the compositions shown in Tables 2 and 3 were prepared using the metallic pigment dispersion prepared by the above method. After mixing and dissolving the solvent and additives to make an ink solvent, the metallic pigment dispersion is added to the ink solvent, and further mixed and stirred with a magnetic stirrer at room temperature and normal pressure for 30 minutes to form a metallic pigment ink. It was set as the composition (S1-S7).

  In Tables 2 and 3, diethylene glycol diethyl ether (DEGDE) and tetraethylene glycol dimethyl ether (TEGDM) manufactured by Nippon Emulsifier Co., Ltd. were used. Further, 縺 | butyrolactone was manufactured by Kanto Chemical. Moreover, N-2043-AF-1 and N-2043-60MEX (polyacryl polyol resin emulsion) are those manufactured by Harima Chemical Co., Ltd., and IB-F370 (polyurethane resin) is BYK-3500 (manufactured by Sanyo Chemical Industries, Ltd.) Surfactant) manufactured by Big Chemie Japan was used. The unit is% by weight.

2. Color ink composition (1) Composition of color ink composition In the composition shown in Table 4 and Table 5, yellow ink composition, magenta ink composition, light magenta ink composition, cyan ink composition, light cyan ink composition, black Ink compositions and white ink compositions were prepared. “Dispersant” is a polyester polymer compound, “N-2043-AF-1” and “N-2043-60MEX” are the polyacryl polyol resin emulsion, and “mixed organic solvent” is , A mixed solvent of diethylene glycol diethyl ether (70% by weight), γ-butyrolactone (15% by weight) and tetraethylene glycol dimethyl ether (15% by weight). Moreover, the numerical value in Table 4 and Table 5 means weight%.

(2) Preparation method of each ink composition A bead mill filled with zirconia beads (2 mm) after stirring the pigment, the dispersant, and the mixed organic solvent (partially) among the compounding components at 3000 rpm with a dissolver for 1 hour. Pre-dispersed with. The average particle diameter of the pigment particles obtained by this preliminary dispersion was 5 μm or less.
Further, this dispersion was performed with a nanomill filled with zirconia beads (0.3 mm) to obtain a pigment dispersion. The average particle diameter of the pigment particles obtained by this main dispersion is 50 nm to 200 nm, although it varies depending on the pigment type.

While stirring the obtained pigment dispersion at 4000 rpm, N-2043-AF-1, a normal additive, a polyoxyethylene derivative, a hollow resin emulsion, and a mixed organic solvent (remainder) are mixed. The desired color ink composition (Y1 to W8) was obtained by adjusting the weight% shown in the composition.
In the same manner, desired color ink compositions (Y9 to W13) were obtained.

In addition, the said hollow resin emulsion was manufactured as follows.
(A) Polymer particle 1
In a 2 L reaction vessel, 80 parts of styrene, 5 parts of methacrylic acid, 15 parts of methyl methacrylate, 1 part of α-methylstyrene dimer, 14 parts of t-dodecyl mercaptan, 0.8 part of sodium dodecylbenzenesulfonate, potassium persulfate 1 0.0 part and 200 parts of water were added, stirred in nitrogen gas, heated to 80 ° C. and subjected to emulsion polymerization for 6 hours. The polymer particles 1 thus obtained had an average particle size of 150 nm (0.15 μm).

(B) Hollow polymer fine particle emulsion 1
To 10 parts (converted to solid content) of the polymer particles 1 obtained in the preceding item (a) together with 0.3 part of sodium lauryl sulfate, 0.5 part of potassium persulfate, and 400 parts of water, A cross-linkable polymerizable monomer composition comprising a mixture of 11.6 parts of divinylbenzene (purity 55% by weight; the remainder is a monofunctional vinyl monomer), 8.4 parts of ethyl vinylbenzene, 5 parts of acrylic acid, and 75 parts of methyl methacrylate. Was added, and the mixture was stirred at 30 ° C. for 1 hour, and further subjected to emulsion polymerization while stirring at 70 ° C. for 5 hours to obtain an aqueous dispersion. The obtained product was measured with a particle size analyzer (Microtrac UPA: Nikkiso Co., Ltd.) and found to have a particle size of 320 nm. When observed separately with a transmission electron microscope, it was a hollow polymer fine particle.

3. Ink Set Using each ink composition obtained in 1 and 2 above, an ink set was configured with the combinations shown in Tables 6 and 7.

4). Printing evaluation test (1) Printing evaluation test 1
Using the ink set shown in 3 above, Roland D.C. G. Two ink jet printers manufactured by SJ-540 Co., Ltd. are used, and the first ink jet printer has ink compositions corresponding to the corresponding color arrays, that is, a black ink composition, a yellow ink composition, and a magenta ink. The black ink, yellow ink, magenta ink, cyan ink, light magenta ink, light cyan ink composition are filled with the composition, cyan ink composition, light magenta ink composition, and light cyan ink composition, respectively. The ink composition was filled in the black row and the white ink composition was filled in the yellow row. Both ink jet printers were printed at a heating temperature of 50 ° C. as shown in the following printing pattern. As recording media, vinyl chloride sheet (Viewcal 2000 (white): manufactured by Sakurai Co., Ltd.), PET film (PG-50L: manufactured by Ramie Corporation), polycarbonate film (Iupilon FE-2000: Mitsubishi Engineering Plastics) Used). And sensory evaluation of the printed matter was performed based on the following evaluation criteria. The results are shown in Table 8.
AAA: Any metallic gloss from high metallic gloss to matte was obtained.
AA: A metallic gloss sufficient to clearly distinguish the reflected object was obtained.
A: A metallic gloss that can slightly distinguish an object reflected in an image was obtained.
B: A metallic gloss with a matte tone (matte tone) was obtained.
C: A metallic gloss was not obtained.

The printing pattern using the ink set is as follows.
a. Print pattern 1
Each ink composition was simultaneously ejected for printing.
b. Print pattern 2
After printing by discharging the metallic ink composition, printing was performed by discharging the chromatic color ink composition and the black ink composition. In this case, the gloss can be masked by printing the black ink composition on the metallic print.
c. Print pattern 3
After printing by discharging the metallic ink composition, printing was performed by discharging the chromatic color ink composition, and further printing was performed by discharging the white ink composition and the black ink composition. In this case, it is possible to change to a matte tone by printing the white ink composition on the glossy metallic print.

(2) Print evaluation test 2
An ink set is formed by combining the metallic ink composition S1 and the oil-based ink composition, and two ink jet printers PM-4000PX (manufactured by Seiko Epson) are used. The first ink jet printer has a black ink composition, The yellow ink composition, the magenta ink composition, the cyan ink composition, the light magenta ink composition, and the light cyan ink composition were filled in the corresponding color columns. In the second inkjet printer, the metallic ink composition S1 was filled in a black row. The white ink composition was filled in the yellow row.

  Then, printing was carried out on a photographic paper <glossy> (manufactured by Seiko Epson, model number: KA450PSK) having an ink receiving layer at room temperature as shown in the above printing pattern. Similarly, the same printing was performed using the metallic ink composition S2 instead of the metallic ink composition S1. Furthermore, sensory evaluation of the printed matter was performed based on the above evaluation criteria. The results are shown in Table 9.

  As shown in Table 9, a recorded matter having a metallic tone image having an arbitrary color tone could be obtained by the inkjet recording method using the ink set.

(3) Printing evaluation test 3
A printed matter was formed in the same manner as in the print evaluation test 1 of 4 (1) above, and a similar sensory evaluation of the printed matter was performed based on the same evaluation criteria. The results are shown in Table 10.

(4) Printing evaluation test 4
A printed material was formed in the same manner as the print evaluation test 2 in 4 (2) above, and a sensory evaluation of the printed material was performed based on the same evaluation criteria. The results are shown in Table 11.

  As shown in Table 11, a recorded matter having a metallic tone image having an arbitrary color tone could be obtained by the inkjet recording method using the ink set.

Claims (6)

An ink composition comprising a metal pigment;
A chromatic ink composition comprising a chromatic pigment;
A white ink composition containing a white pigment, and an ink jet recording method for discharging droplets and attaching the droplets to a recording medium,
The content of the white pigment in the white ink composition is 1 to 20% by weight,
The content of the chromatic pigment in the chromatic ink composition is 0.5 to 12% by weight ,
After forming an image having a metallic luster by ejecting an ink composition comprising a pre-Symbol metal pigments, on which, additionally ejecting the white ink composition ejected the chromatic ink composition, metals gloss Form an image ,
An ink jet recording method for forming the metallic gloss image in which a metallic metallic gloss is imparted to at least the color tone of the chromatic pigment and the white pigment .   When the ink composition containing the metal pigment is discharged onto a recording medium, the measured values of 20 °, 60 °, and 85 ° specular gloss specified in JIS Z8741 are 200 or more, 200 or more, and 100, respectively, simultaneously. The inkjet recording method according to claim 1, wherein an image showing the above numerical values can be formed. Furthermore, the ink jet recording method of Claim 1 or 2 using the ink set provided with the black ink composition containing a black pigment.   The inkjet recording method according to claim 3, wherein a content of the black pigment in the black ink composition is 0.5 to 12% by weight. As the chromatic ink composition, a set of at least one of a cyan ink composition and a light cyan ink composition, a magenta ink composition and a light magenta ink composition,
The inkjet recording method according to claim 1, comprising: Printing by heating the recording medium, ink jet recording method according to any one of claims 1-5.