JP5214103B2 - Metallic pigment, ink composition, and ink jet recording method - Google Patents

Description

  The present invention relates to a metallic pigment, an ink composition, and an inkjet recording method. More specifically, it is possible to create a printed matter having a metallic luster, stable printing is possible even with a printer using an ink jet nozzle having a nozzle diameter of 30 μm or less, and no heat treatment is required. The present invention relates to a metallic pigment, an ink composition, and an inkjet recording method that enable inkjet recording without limitation.

Conventionally, in order to reproduce metallic luster on printed matter, pigments made of metals or alloys such as aluminum, gold, silver, brass, printing inks made of pearl pigments, adhesive foils, and transfer foils by heat fusion have been used. It was.
In addition, with the recent development of inkjet printing technology, there is an increasing demand for obtaining printed matter having a metallic luster even in inkjet printing.
On the other hand, in the aluminum pigment currently marketed for metallic pigments, the average particle diameter is 10 μm or more (for example, refer to Patent Documents 1 and 2), and a fine nozzle (diameter 30 μm or less) of an inkjet printer and a filtration filter are used. It is very difficult to pass. Further, these aluminum pigments have a drawback that it is difficult to obtain a mirror gloss because the particle diameter is too large. In addition, since the aluminum pigment reacts with the surrounding water when the particle size is reduced, it is very difficult to reduce the particle size to 1 μm or less by the conventional pulverization method or atomization method. A pigment having an average particle diameter of 200 nm or less, which is the average particle diameter of the pigment used, cannot be prepared.

  On the other hand, there is a method of forming a metal thin film on a substrate using a noble metal colloid such as gold or silver, but metal colloid particles having an average particle diameter of several tens of nm cannot reproduce the metallic luster. For example, stable gold colloidal particles have a particle diameter of about 10 to 20 nm, and in this state, the color of the colloidal dispersion is purple. In this case, it is necessary to heat at 150 ° C. or higher in order to obtain a gold thin film. Further, by adding a protective colloid, it is possible to stably disperse a gold colloid having a larger particle diameter. In this case, however, a metal thin film cannot be obtained unless the protective colloid is decomposed and removed. For these reasons, the method using metal colloid requires some post-treatment after printing. In particular, when heat treatment is performed, there is a drawback that the print media is very limited. In the case of pressurizing treatment, there is a disadvantage that the printing medium is limited, and an equipment burden that requires pressurizing equipment is naturally generated (see, for example, Patent Document 3). Further, noble metals (Au, Ag, Ru, Rh, Pd, Os, Ir, Pt) are usually used as metal colloids, but they are difficult to use for decoration, decoration, advertisement printing, etc. from the viewpoint of cost.

US Pat. No. 4,233,195 US Pat. No. 5,662,738 JP 2004-175832 A

  Therefore, the object of the present invention is to solve the problems of the prior art and to create a printed matter having a metallic luster, and it is possible to perform stable printing even with a printer using an inkjet nozzle having a nozzle diameter of 30 μm or less. Another object of the present invention is to provide a metallic pigment, an ink composition, and an ink jet recording method that enable ink jet recording which does not require a heat treatment or the like and is not limited to a print medium (recording medium).

  The present inventor has established the stability of printing in ink jet recording by setting the factors involved in the average particle size of the metallic pigment using the metal foil pieces contained in the ink composition and the maximum particle size in the particle size distribution within a specific range. In addition, the present inventors have found that the gloss of the recorded matter is improved and have reached the present invention.

That is, the present invention is achieved by the following configuration.
(1) A metallic pigment having an average thickness of 30 to 100 nm, a metal foil piece having a 50% average particle size of 1.0 μm or more and 4.0 μm or less, and a maximum particle size in a particle size distribution of 12 μm or less.
(2) The metal or metal compound layer and the release resin layer of the pigment base material in which the metal foil piece has a structure in which a release resin layer and a metal or metal compound layer are sequentially laminated on a sheet-like substrate surface. The metallic pigment according to (1), wherein the metallic pigment is peeled off and pulverized from the sheet-like substrate with the interface of
(3) The metallic pigment according to (2), wherein the metal or metal compound layer is produced by a vacuum deposition method.
(4) The metallic pigment according to (2), wherein the peeling and pulverization are performed by ultrasonic treatment in the liquid of the pigment raw material.

(5) An ink composition containing the metallic pigment according to any one of (1) to (4).
(6) The ink composition according to (5), which contains a silicone-based surfactant, a polyoxyethylene-based surfactant, or an acetylenic diol-based surfactant.
(7) The ink composition according to (5) or (6), which contains a binder resin.
(8) The ink composition according to (7), wherein the binder resin is polyvinyl butyral or cellulose acetate butyrate.
(9) An ink jet recording method using the ink composition according to any one of (5) to (8) and an ink jet head having a nozzle diameter of 30 μm or less.
(10) The inkjet recording method according to (9), wherein the ratio (average particle diameter / nozzle diameter) between the 50% average particle diameter of the metallic pigment and the nozzle diameter of the inkjet head is 0.15 or less.

  The metallic pigment, ink composition, and inkjet recording method of the present invention can produce a printed matter having a metallic luster, can be stably printed even with a printer using an inkjet nozzle having a nozzle diameter of 30 μm or less, heat treatment, etc. Therefore, inkjet recording that does not limit the print medium (recording medium) is possible.

Hereinafter, the metallic pigment, ink composition and ink jet recording method of the present invention will be described in detail.
The metallic pigment of the present invention is a metal foil piece having an average thickness of 30 to 100 nm and a 50% average particle size of 1.0 μm or more and 4.0 μm or less, and the maximum particle size in the particle size distribution is 12 μm or less.
Since the metallic pigment of the present invention has the above-mentioned factors related to the average particle size and particle size distribution, it is possible to produce a printed matter having a metallic luster and is stable even in a printer using an ink jet nozzle having a nozzle diameter of 30 μm or less. Printing is possible.
In order to obtain metallic luster with conventional metallic pigments, aluminum pigments require an average particle size of 10 μm or more, generally the average particle size is 20 μm or more, and the maximum particle size in the particle size distribution exceeds 30 μm. End up. In this case, it cannot be used for an ink jet printer using an ink jet nozzle having a nozzle diameter of 30 μm or less.

  Further, the metallic pigment of the present invention preferably has a maximum particle size in the particle size distribution of 10 μm or less. In particular, when an inkjet nozzle having a diameter of 20 μm is used, the maximum particle size in the particle size distribution needs to be 10 μm or less. In addition, when performing stable printing using an inkjet nozzle having a diameter of 20 μm, the average particle size of the particle size distribution must be 4.0 μm or less.

  The metallic pigment of the present invention is not particularly limited as long as it uses a metal foil piece and satisfies the above-mentioned regulations relating to the average particle size and particle size distribution. For example, the release resin layer and the metal on the sheet-like substrate surface Alternatively, a composite pigment base material having a structure in which a metal compound layer is sequentially laminated may be peeled and pulverized from the sheet-like substrate with an interface between the metal or metal compound layer and the release resin layer as a boundary. .

The metal or metal compound used for the metal or metal compound layer of the composite pigment base material for producing the metallic pigment of the present invention is not particularly limited as long as it has a function such as having a metallic luster. However, aluminum, silver, gold, nickel, chromium, tin, zinc, indium, titanium, copper, and the like are used, and at least one of these simple metals, metal compounds, alloys thereof, and mixtures thereof is used.
The metal or metal compound layer is preferably formed by vacuum deposition, ion plating or sputtering. The thickness of these metal or metal compound layers is not particularly limited, but is preferably in the range of 30 to 100 nm. If it is less than 30 nm, it is inferior in reflectivity and glitter, and the performance as a metal pigment is lowered. If it exceeds 100 nm, the apparent specific gravity increases, and the dispersion stability of the metallic pigment decreases. An unnecessary increase in the metal or metal compound layer only causes sedimentation due to an increase in the weight of the particles, and the reflectivity and brightness are not significantly changed even with a film thickness larger than this.

The release resin layer in the composite pigment base material for producing the metallic pigment of the present invention is an undercoat layer of the metal or metal compound layer, but for improving the peelability from the sheet-like substrate surface. It is a peelable layer. The resin used for this release resin layer is not particularly limited, but for example, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polyacrylic acid, polyacrylamide, cellulose derivative, polyvinyl butyral, acrylic acid copolymer, or modification Nylon resin is preferred.
A layer is formed by applying a solution of one or a mixture of two or more of the above resins and drying. The coating solution can contain additives such as a viscosity modifier.

The release resin layer is applied by commonly 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 the thickness is less than 0.5 μm, the amount as a dispersion resin is insufficient.

Although it does not specifically limit as a sheet-like base material in the composite pigment base material for manufacturing the metallic pigment of this invention, Polyester film, such as polytetrafluoroethylene, polyethylene, a polypropylene, a polyethylene terephthalate, 66 nylon, 6 nylon, etc. And a releasable film such as a polyamide film, a polycarbonate film, a triacetate film and a polyimide 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 metal compound layer may be sandwiched between protective layers. Examples of the protective layer include a silicon oxide layer and a protective resin layer.
Although a silicon oxide layer will not be specifically limited if it is a layer containing a silicon oxide, It is preferable to form from silicon alkoxides, such as tetraalkoxysilane, or its polymer by a sol-gel method.
A silicon oxide layer coating film is formed by applying an alcohol solution in which the silicon alkoxide or a polymer thereof is dissolved and baking it.

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. Preferably formed from a 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 metal compound layer.

Further, a color material layer may be provided between the “protective layer” and the “metal or metal compound 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. As the color material used for the color material layer, either a dye or a pigment may be used. 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, and as the color material dispersion resin, polyvinyl butyral, an acrylic acid copolymer, or the like is preferable. In this case, the color material layer is prepared by dispersing or dissolving a pigment, a color material dispersing resin and other additives as necessary in a solvent, and forming a uniform liquid film by spin coating as a solution, followed by drying. It is preferable to prepare as a resin thin film.
In the production of the composite pigment base material for producing the metallic pigment of the present invention, it is preferable in terms of work efficiency that both the colorant layer and the protective layer are formed by coating.

As a composite pigment base material for producing the metallic pigment of the present invention, a layer structure having a plurality of sequential laminated structures of the release resin layer and a metal or metal compound layer is also possible. At that time, the total thickness of the laminated structure composed of a plurality of metals or metal compound layers, that is, the metal or metal compound layer-exfoliation resin layer-metal or metal, excluding the sheet-like base material and the exfoliation resin layer immediately above it. Metal compound layer—Release resin layer—The thickness of the metal or metal compound 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 metal compound layer were laminated | stacked one by one on both surfaces of the sheet-like base material surface is also mentioned, it is not limited to these.

The metallic pigment of the present invention can be obtained by exfoliating the metal or metal compound layer of the composite pigment base material from the sheet-like base material with the release resin layer as a boundary, pulverizing and refining.
The peeling treatment method is not particularly limited, but is a method in which the composite pigment raw material is immersed in a liquid, or a composite pigment that has been subjected to ultrasonic treatment at the same time as being immersed in the liquid, and is peeled off from the peeling treatment. A method of performing the pulverization treatment is preferable.
In the metallic 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 metallic pigment, the resin derived from the release resin layer also has a function of imparting adhesiveness to a recording medium such as paper.

The metallic pigment of the present invention is dispersed and contained in an appropriate liquid medium to obtain an ink composition.
The liquid medium used in the ink composition using the metallic pigment of the present invention (hereinafter also referred to as the ink composition of the present invention) may be aqueous or organic.
The organic liquid medium is preferably a polar organic solvent, for example, 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 (for example, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, or ethyl propionate), or ethers (for example, diethyl ether, dipropyl ether, Tetrahydrofuran, dioxane or the like) can be used.
Other preferable organic solvents include, for example, a mixture of a diethylene glycol compound that is liquid at normal temperature and pressure and a dipropylene glycol compound that is liquid at normal temperature and pressure as described in WO 2002/055619. it can.

In the case of using an organic liquid medium, it is preferable that a polyoxyethylene derivative of a nonionic surfactant or a silicone surfactant is included.
As the polyoxyethylene derivative, an acetylenic diol surfactant can be used. The acetylene diol surfactant may have a polyoxyalkylene structure. Specific examples of the acetylenic diol-based surfactant include Surfynol 104, 82, 465, 485, or TG (all available from Air Products and Chemicals. Inc.), Orphin STG, and Orphin E1010 (all Nisshin Chemical Co., Ltd.) Product name).
In addition, as the polyoxyethylene derivative, other commercially available products can be used. Specific examples thereof include Nissan Nonion A-10R, A-13R (Nippon Yushi Co., Ltd.), Floren TG-740W, Examples include D-90 (Kyoeisha Chemical Co., Ltd.), Emulgen A-90, A-60 (Kao Corporation), or Neugen CX-100 (Daiichi Kogyo Seiyaku Co., Ltd.).

Examples of silicone surfactants include dimethylsiloxane, polyether-modified polydimethylsiloxane, methylstyrene-modified polydimethylsiloxane, olefin-modified polydimethylsiloxane, alcohol-modified polydimethylsiloxane, alkyl-modified polydimethylsiloxane, and polyester-modified polydimethylsiloxane. And methacryl-modified polydimethylsiloxane and amino-modified polydimethylsiloxane.
Moreover, BYK-307, 331, 333, 347, 348, UV-3500, UV-3510, UV-3530, UV-3570 (manufactured by Big Chemie Japan Co., Ltd.), KF-860, 8005, 6004, 351, 353 354L, 355A, 615A, 618, 6011, 6015, X-22-2426, 164C, 2404 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used.

In the case where an organic liquid medium is used, the content of the nonionic surfactant in the ink composition of the present invention can be selected as appropriate, but is preferably relative to the pigment content in the ink composition. Is 0.01 to 10% by weight, more preferably 0.05 to 3.0% by weight.
When using an organic liquid medium, the ink composition of the present invention preferably contains a binder resin.
Examples of the binder resin include acrylic resin, styrene acrylic resin, rosin modified resin, phenol resin, terpene resin, polyester resin, polyamide resin, epoxy resin, vinyl chloride vinyl acetate copolymer, and fibrous resin (for example, cellulose Acetate butyrate) or vinyltoluene-α-methylstyrene copolymer can be used. The binder resin can further improve the fixability of the pigment to the recording medium depending on the amount of the binder resin added. Furthermore, the viscosity of the ink composition of the present invention can be adjusted by the binder resin. The viscosity (viscosity at a temperature of 20 ° C.) of the ink composition of the present invention is, for example, 10 mPa · s, more preferably 5 mPa · s.

  In addition, the ink composition of the present invention can further contain other additives contained in a normal 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. As the surfactant, any of anionic, cationic, amphoteric or nonionic surfactants can be used.

The ink composition containing the metallic pigment of the present invention may contain glycol ether.
The glycol ether contained in the ink composition of the present invention includes methyl, n-propyl, i-propyl, n-butyl, i-butyl, hexyl, and 2-ethylhexyl aliphatic, allyl having a double bond, and There are ethylene glycol-based ether and propylene glycol-based ether based on each group of phenyl, and it is colorless and has little odor, and since it has an ether group and a hydroxyl group in the molecule, it has characteristics of both alcohols and ethers. It is liquid at room temperature.
Examples include 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, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene Recall monomethyl ether, and dipropylene glycol monoethyl ether.

The ink composition of the present invention can be prepared by a known conventional method. For example, first, a metallic pigment, a dispersant, and the liquid medium are mixed, and then 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. Subsequently, a pigment ink composition can be obtained by adding the liquid medium, nonionic surfactant, binder resin, and other additives (for example, a dispersion aid or a viscosity modifier) with stirring.
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 ink composition of the present invention 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.
In the ink composition according to the present invention, the metallic pigment is preferably 2% by weight (wt%) or less of the entire ink composition because a more stable printing result can be obtained.

  The ink composition of the present invention can be applied to various ink jet recording systems. That is, an electric field control method that discharges ink using electrostatic attraction, a drop-on-demand method (or pressure pulse method) that discharges ink using the driving pressure of a piezo element, and a bubble due to high heat The present invention can be applied to various ink jet recording systems such as a bubble or thermal jet system that ejects ink using pressure generated by forming and growing.

In the ink jet recording method using the ink composition of the present invention, it is preferable to use an ink jet head having a nozzle diameter of 30 μm or less.
The ratio of the average particle diameter of the metallic pigment of the present invention to the nozzle diameter of the inkjet head (average particle diameter / nozzle diameter) is preferably 0.15 or less.

The present invention will be described more specifically with reference to the following examples. However, the scope of the present invention is not limited to these examples.
[Example 1]
1. Production of Aluminum Pigment Dispersion (1) A resin film coating solution having the following composition was formed on a PET film having a film thickness of 100 μm by spin coating, and then dried to form a resin thin film layer.

(Resin layer coating solution)
Polyvinyl butyral resin (Esretk BL-10,
Sekisui Chemical Co., Ltd.) 3.0% by weight
Glycerin 2.0% by weight
IPA (isopropyl alcohol) remaining

(2) An aluminum vapor deposition layer having a film thickness of 70 nm was formed on the above resin layer using the following apparatus.
Apparatus: Vacuum device, VE-1010 type vacuum evaporation system

(3) The PET film having a laminate of the resin layer and the aluminum vapor deposition layer formed by the above method is simultaneously peeled, refined and dispersed in IPA using an ultrasonic disperser for 12 hours, and the dispersion processing accumulated time A 12 hour aluminum pigment (also referred to as metallic pigment) dispersion was prepared.
The pigment content of the aluminum pigment dispersion obtained by this method was 5.0 wt%.
Dispersing machine: Aswan Co., Ltd., ultrasonic cleaning machine VS-150

2. Particle size and particle size distribution evaluation The particle size and particle size distribution of the above aluminum pigment dispersion were measured using the following apparatus. The evaluation results are shown in Table 1 below.
Particle size and particle size distribution measurement: LMS-30 manufactured by Seishin Corporation

3. Measurement of average thickness The average thickness of the metallic pigment in the ink composition was evaluated by measuring 10 average thicknesses randomly selected from an electron microscope image and taking the average value.

4). Preparation of metallic pigment-containing ink composition Using the aluminum pigment dispersion prepared by the above method, a metallic pigment-containing ink composition 1 was prepared so as to have the following composition. After mixing and dissolving the solvent and additives to make an ink solvent, the pigment dispersion was added to the ink solvent, and further mixed and stirred at room temperature for 30 minutes.

(Metallic pigment-containing ink composition)
Aluminum pigment (solid component) 1 wt%
Glycerin 20 wt%
Triethylene glycol monobutyl ether 40 wt%
BYK-UV3500 0.1wt%
IPA (isopropyl alcohol) remaining

5. Filterability evaluation The filterability of the metallic pigment-containing ink composition after mixing and stirring was evaluated using a stainless mesh filter having a filtration accuracy of 10 μm. The evaluation results are shown in Table 1.

6). Recording / printing stability, glossiness evaluation Seiko Epson Co., Ltd. inkjet printer EM-930C (nozzle φ: 25 μm) is used to print on photographic paper <glossy> (model number KA450PSK) manufactured by the company, giving a metallic luster. It confirmed that the printing surface which has was obtained.
7. Comprehensive evaluation It judged as follows from the result of said 6.
A: The ink jet recording apparatus can be used without any problem.
B: It is difficult to use the ink jet recording apparatus.
C: It is determined that the ink jet recording apparatus cannot be used.

[Example 2]
The same operation as in Example 1 was performed. However, the dispersion treatment integration time of 12 hours was extended to 18 hours to prepare a metallic pigment-containing ink composition 2. Table 1 shows each evaluation result similar to that in Example 1.
Example 3
The same operation as in Example 1 was performed. However, the dispersion treatment integration time of 12 hours was extended to 24 hours to prepare a metallic pigment-containing ink composition 3. Table 1 shows each evaluation result similar to that in Example 1.
Example 4
The same operation as in Example 1 was performed. However, the dispersion treatment integration time of 12 hours was extended to 72 hours to prepare a metallic pigment-containing ink composition 4. Table 1 shows each evaluation result similar to that in Example 1.

Example 5
The same operation as in Example 1 was performed. However, the dispersion treatment time was extended to 18 hours, and the vapor deposition conditions were changed to form an aluminum vapor deposition film having a thickness of 32 nm, thereby preparing a metallic pigment-containing ink composition 5. Table 1 shows each evaluation result similar to that in Example 1.
Example 6
The same operation as in Example 1 was performed. However, the dispersion treatment time was extended to 18 hours, and the vapor deposition conditions were changed to form an aluminum vapor deposition film having a thickness of 92 nm, thereby preparing a metallic pigment-containing ink composition 6. Table 1 shows each evaluation result similar to that in Example 1.

[Comparative Example 1]
The same operation as in Example 1 was performed. However, the dispersion treatment integration time of 12 hours was shortened to 1 hour to prepare a metallic pigment-containing ink composition 7. Table 1 shows each evaluation result similar to that in Example 1.
[Comparative Example 2]
The same operation as in Example 1 was performed. However, the dispersion treatment integration time of 12 hours was shortened to 10 hours to prepare a metallic pigment-containing ink composition 8. Table 1 shows each evaluation result similar to that in Example 1.

[Comparative Example 3]
The same operation as in Example 1 was performed. However, the dispersion treatment time was extended to 18 hours, and the vapor deposition conditions were changed to form an aluminum vapor deposition film having a thickness of 25 nm, thereby preparing a metallic pigment-containing ink composition 9. Table 1 shows each evaluation result similar to that in Example 1.
[Comparative Example 4]
The same operation as in Example 1 was performed. However, the dispersion treatment time was extended to 18 hours and the vapor deposition conditions were changed to form an aluminum vapor deposition film having a thickness of 110 nm to prepare a metallic pigment-containing ink composition 10. Table 1 shows each evaluation result similar to that in Example 1.

In the table, X10, X50, and X90 indicate the particle diameters when the cumulative value from the small particle diameter side in the particle size distribution is 10%, 50%, and 90%, respectively. is the numerical value of X50, X _MAX shows the maximum particle diameter in the particle size distribution.

  As is apparent from Table 1, the metallic pigments of the respective examples according to the present invention obtained excellent results in both satisfactory printing stability and glossiness, but the factors involved in the average particle diameter were not specified. The metallic pigments of the respective comparative examples were unsatisfactory as ink jet ink compositions.

Example 7
Ink composition 11 was prepared in the same manner as in Example 3, except that the composition was as follows.

Aluminum pigment (solid component) 1 wt%
Polyvinyl butyral (Sekisui Chemical Co., Ltd., 3 wt%
ESREC BL-10)
Diethylene glycol diethyl ether 40 wt%
(Nippon Emulsifier Co., Ltd.)
Olfine E1010 (Nisshin Chemical Industry Co., Ltd.) 0.5wt%
Dipropylene glycol monomethyl ether remaining amount (manufactured by Nippon Emulsifier Co., Ltd.)

Example 8
Ink composition 12 was prepared in the same manner as in Example 7, except that the composition was as follows.

Aluminum pigment (solid component) 1 wt%
Cellulose acetate butyrate (Kanto Chemical Co., Ltd., 4 wt%
(Average molecular weight 16,000, butylation rate 50-54%)
Diethylene glycol diethyl ether 40 wt%
(Nippon Emulsifier Co., Ltd.)
Olfine E1010 (Nisshin Chemical Industry Co., Ltd.) 0.5wt%
Dipropylene glycol monomethyl ether remaining amount (manufactured by Nippon Emulsifier Co., Ltd.)

Example 9
Ink composition 13 was prepared in the same manner as in Example 7, except that the composition was as follows.

Aluminum pigment (solid component) 1 wt%
Cellulose acetate butyrate (Kanto Chemical Co., Ltd., 4 wt%
(Average molecular weight 16,000, butylation rate 50-54%)
Diethylene glycol diethyl ether 40 wt%
(Nippon Emulsifier Co., Ltd.)
BYK-UV3500 0.2wt%
(Made by Big Chemie Japan Co., Ltd.)
Dipropylene glycol monomethyl ether remaining amount (manufactured by Nippon Emulsifier Co., Ltd.)

[Measurement of specular gloss based on Japanese Industrial Standards]
Ink composition 3 (Example 3), ink composition 11 (Example 7), ink composition 12 (Example 8), ink composition 13 (Example 9) and ink composition 10 (Comparative Example 4) Using EM-930C (nozzle diameter: φ25 μm) manufactured by Seiko Epson Corporation, recording (solid printing) was performed on photographic paper (gloss; KA450PSK) manufactured by the same company. The recorded matter was evaluated for glossiness at 20 ° and 60 ° by a method based on JIS Z 8741 (1997) using a gloss meter MULTIGLOSS 268 manufactured by Konica Minolta Co., Ltd. The results are shown below.

  As is apparent from Table 2, it was confirmed that the ink composition of each example according to the present invention can provide a recording surface having an excellent metallic luster as compared with the ink composition of the comparative example.

Claims (4)

An ink composition containing a metallic pigment used for an inkjet head having a nozzle diameter of 30 μm or less ,
The ratio of the 50% average particle diameter of the metallic pigment to the nozzle diameter (average particle diameter / nozzle diameter) is 0.15 or less,
The metallic pigment has a foil strip of aluminum or an aluminum compound, wherein is 50% average particle diameter of 1.0μm or more 4.0μm or less, the maximum particle size is at 12μm or less, the average thickness before Kihakuhen An ink composition having a thickness of 30 nm or more and less than 100 nm . A binder resin, wherein the binder resin ink composition according to claim 1 is polyvinyl butyral or cellulose acetate butyrate.   An ink jet recording apparatus comprising the ink composition according to claim 1 and the head. A recorded matter recorded by the recording apparatus according to claim 3 .