JP2012219202A - Nonaqueous ink composition for inkjet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous ink composition for inkjet which has appropriate viscosity and records an image having excellent glossiness.SOLUTION: The nonaqueous ink composition for inkjet contains a glittering pigment, a compound represented by general formula (1), and an organic solvent. The compound represented by general formula (1) is at least one compound selected from triacetin, propionin, and tributyrin. The content of the compound represented by general formula (1) is ≥5 mass% and ≤40 mass% (wherein, R, Rand Rin general formula (1) independently represent 1C-3C alkyl groups).

Description

  The present invention relates to a non-aqueous ink composition for inkjet.

  Conventionally, as a method of forming a coating film having a metallic luster on a printed material, gold powder produced from brass, aluminum fine particles, etc., printing ink using silver powder as a pigment, foil press printing using metal foil, metal foil was used. Thermal transfer systems have been used.

  In recent years, in addition to the above-described method for forming a coating film having a metallic luster, many examples of application to an ink jet method have been found, and one of them is metallic printing. Metallic printing using an inkjet method is mainly performed using an inkjet printer or the like. In printing using an ink jet printer, it is necessary to adjust the viscosity of the ink within an appropriate range from the viewpoint of improving the ejection stability of the ink and forming a good image on the recording medium. For example, Patent Document 1 discloses a non-aqueous ink composition containing a metal pigment, an organic solvent, and a cellulose acetate butyrate resin.

JP 2009-256565 A

  However, when a metallic gloss image is recorded on a recording medium using a conventional non-aqueous ink composition containing a pigment made of a metal such as aluminum (hereinafter also simply referred to as “metal pigment”), it is good for inkjet use. Depending on the component added to adjust the viscosity range, the glossiness of the recorded image may be lowered.

  An object of some embodiments of the present invention is to solve at least a part of the above-described problems, and to provide a non-aqueous ink composition for inkjet that can record an image having excellent gloss while having a good viscosity. It is to provide.

  The present invention can be realized as the following aspects or application examples.

[Application Example 1]
One aspect of the non-aqueous ink composition for inkjet according to the present invention is:
It contains a luster pigment, a compound represented by the following general formula (1), and an organic solvent.

(In the general formula (1), R ¹ , R ² and R ³ each independently represents an alkyl group having 1 to 3 carbon atoms.)
According to the non-aqueous ink composition for inkjet of Application Example 1, an image having excellent glossiness can be recorded while having a good viscosity as an inkjet application.

[Application Example 2]
In application example 1,
The compound represented by the general formula (1) may be at least one selected from triacetin, propionin and tributyrin.

[Application Example 3]
In application example 1 or application example 2,
The content of the compound represented by the general formula (1) may be 5% by mass or more and 40% by mass or less.

[Application Example 4]
In any one of Application Examples 1 to 3,
The glitter pigment is a tabular grain,
When the major axis on the plane of the tabular grains is X, the minor axis is Y, and the thickness is Z,
The 50% average particle diameter R50 of the equivalent circle diameter determined from the area of the XY plane of the tabular grains is 0.5 μm or more and 3 μm or less and can satisfy the condition of R50 / Z> 5.

[Application Example 5]
In any one of Application Examples 1 to 4,
The glitter pigment may be aluminum or an aluminum alloy.

[Application Example 6]
In any one of Application Examples 1 to 5,
The organic solvent can contain at least one of alkylene glycol ethers and lactones.

[Application Example 7]
In any one of Application Examples 1 to 6,
The viscosity at a measurement temperature of 20 ° C. can be 2 mPa · s or more and 8 mPa · s or less.

  Hereinafter, preferred embodiments of the present invention will be described. The embodiment described below describes an example of the present invention. In addition, the present invention is not limited to the following embodiments, and includes various modifications that are implemented within a range that does not change the gist of the present invention.

1. Non-aqueous ink composition for inkjet The non-aqueous ink composition for inkjet according to an embodiment of the present invention (hereinafter, also simply referred to as “brilliant ink”) includes a glitter pigment, an organic solvent, the following general formula ( And a compound represented by 1). In the present invention, the “non-aqueous ink composition” means that water is not intentionally added when the ink composition is produced, and the ink composition is inevitably mixed during production or storage. It may contain a small amount of moisture.

  Hereinafter, each component contained in the glitter ink in the present embodiment will be described in detail.

1.1. Compound Represented by General Formula (1) The glitter ink according to this embodiment contains a compound represented by the following general formula (1).

In the general formula ^{(1), R 1, R} 2, R 3 each independently represent a 1 to 3 of alkyl group carbon atoms. The alkyl group having 1 to 3 carbon atoms may be a linear or branched alkyl group, such as a methyl group, an ethyl group, an n-propyl group, or an iso-propyl group.

  One of the functions of the compound represented by the general formula (1) is to adjust the viscosity of the glitter ink. When the compound represented by the general formula (1) is used, it becomes easy to adjust the glitter ink to a viscosity suitable for inkjet applications.

  Further, the compound represented by the general formula (1) does not include a group (particularly, a hydroxyl group) that easily absorbs moisture in the structure. In this way, when a compound that does not have a group that easily absorbs moisture is used, it is possible to reduce inhalation of moisture in the air into the glitter ink, so that a glitter pigment (described later) contained in the glitter ink. Can be reduced from reacting with moisture and the like, and the glossiness of the recorded image is hardly lowered.

  As described above, the compound represented by the general formula (1) is excellent in the viscosity adjusting function of the glitter ink, and it is difficult to reduce the gloss of the image recorded by the glitter ink. Since an excellent image can be recorded, it is very useful.

  Examples of the compound represented by the general formula (1) include triacetin, propionin and tributyrin.

  The content of the compound represented by the general formula (1) is preferably 5% by mass or more and 40% by mass or less, more preferably 5% by mass or less and 30% by mass or less, with respect to the total mass of the glitter ink. Especially preferably, it is 10 mass% or more and 30 mass% or less. When the content of the compound represented by the general formula (1) is within the above range, the viscosity of the glitter ink can be easily adjusted to a viscosity range suitable for inkjet applications, and the discharge stability of the glitter ink is excellent. It will be. On the other hand, when the content of the compound represented by the general formula (1) exceeds the above range, the viscosity of the glitter ink may increase, and the discharge stability of the glitter ink may decrease. Further, when the content of the compound represented by the general formula (1) is less than the above, the viscosity of the glitter ink may be decreased, and the discharge stability of the glitter ink may be decreased.

1.2. Bright pigment The bright ink according to the present embodiment contains a bright pigment. As the glitter pigment, any pigment can be used as long as it is within a range in which ink droplets can be ejected by an ink jet recording method. The glitter pigment has a function of imparting glitter when the glitter ink is deposited on the recording medium. Examples of such bright pigments include pearl pigments and metal pigments. Specific examples of the pearl pigment include pigments having pearly luster and interference gloss such as titanium dioxide-coated mica, fish scale foil, and bismuth oxychloride. On the other hand, specific examples of the metal pigment include particles of aluminum, silver, gold, platinum, nickel, chromium, tin, zinc, indium, titanium, copper, etc., and these simple substances or alloys thereof, and mixtures thereof. At least one selected from can be used.

  Among the bright pigments exemplified above, aluminum or an aluminum alloy is preferable from the viewpoint of high glossiness and cost. When an aluminum alloy is used, the other metal element or non-metal element added to aluminum is not particularly limited as long as it has glitter, but silver, gold, platinum, nickel, chromium, tin, Zinc, indium, titanium, copper and the like can be mentioned, and at least one selected from these can be preferably used.

  Since the compound represented by the general formula (1) contained in the glitter ink has low reactivity with metals, it is not necessary to perform a special surface treatment on the metal pigment. Moreover, it is not necessary to perform a special surface treatment on the metal pigment by selecting a component having low reactivity to the metal from components such as an organic solvent described later contained in the glitter ink.

  The glitter pigment used in the present embodiment preferably has a 50% average particle diameter (d50) in terms of a sphere by a light scattering method of 0.8 μm or more and 1.2 μm or less.

  Here, the “sphere-converted 50% average particle diameter (d50) by light scattering method” is a value obtained as follows. That is, the diffracted and scattered light generated by irradiating the particles in the dispersion medium with light is measured by a detector disposed in front, side, and rear of the dispersion medium. Using the measured values obtained, assuming that the particles that are originally indefinite are spherical, a cumulative curve is obtained with the total volume of the particle population converted to a sphere equal to the volume of the particles as 100%, The point at which the cumulative value at that time is 50% is defined as “50% average particle diameter (d50) in terms of sphere by light scattering method”. Examples of the measuring apparatus include a laser diffraction / scattering particle size distribution measuring instrument (manufactured by Seishin Co., Ltd., product name “LMS-2000e”). When the 50% average particle diameter (d50) in terms of sphere by the light scattering method is in the above range, an image having high glitter can be recorded on the recording medium, and the ejection stability of the ink from the nozzles is also improved. .

  The glitter pigment used in the present embodiment is preferably tabular grains. A “tabular grain” refers to a grain having a substantially flat surface (XY plane) and a substantially uniform thickness (Z). In addition, a substantially flat surface means the surface where the projected area of the said tabular grain becomes the maximum.

  The “equivalent circle diameter” is the diameter of a circle having an area equal to the projected area of the substantially flat surface (XY plane) of the 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 preferably 0.5 μm or more and 3 μm or less from the viewpoint of glitter and ejection stability. More preferably, it is not less than 75 μm and not more than 2 μm. When the 50% average particle diameter (R50) is less than 0.5 μm, the glitter tends to be insufficient. On the other hand, when the 50% average particle diameter (R50) exceeds 3 μm, the recording stability tends to decrease.

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

  The particle size distribution (CV value) of the glitter pigment is determined by the following formula (2).

CV value = (standard deviation of particle size distribution / average value of particle diameter) × 100 (2)
Here, the CV value obtained is preferably 60 or less, more preferably 50 or less, and particularly preferably 40 or less. By selecting a bright pigment having a CV value of 60 or less, an effect of excellent recording stability can be obtained.

  In addition, the relationship between the 50% average particle diameter (R50) of the equivalent circle diameter and the thickness Z is preferably R50 / Z> 5 from the viewpoint of securing high glitter. When the value of R50 / Z is 5 or less, the glitter tends to be insufficient. The thickness Z is measured using a transmission electron microscope or a scanning electron microscope. For example, a transmission electron microscope (manufactured by JEOL Ltd., product name “JEM-2000EX”), a field emission scanning electron microscope is used. (Manufactured by Hitachi, Ltd., product name “S-4700”). The thickness Z means an average thickness and is an average value obtained by performing the measurement 10 times.

  The maximum equivalent particle diameter Rmax obtained from the area of the XY plane of the tabular grains is preferably 10 μm or less from the viewpoint of preventing ink clogging in the ink jet recording apparatus. By setting Rmax to 10 μm or less, it is possible to prevent clogging of the nozzles of the ink jet recording apparatus and the mesh filter provided in the ink flow path.

  As the method for producing the glitter pigment, for example, a composite pigment base material having a structure in which a release resin layer and a metal or alloy layer are sequentially laminated on a sheet-like base material is prepared, and the composite pigment base material is prepared. Examples include a method of exfoliating from the sheet-like base material at the interface between the body metal or alloy layer and the exfoliating resin layer as a boundary, pulverizing and refining to obtain tabular grains. And among the obtained tabular grains, particles having a 50% average particle diameter (d50) in terms of sphere by light scattering method of 0.8 μm or more and 1.2 μm or less are collected. Or when the major axis on the plane of the obtained tabular grain is X, the minor axis is Y, and the thickness is Z, 50% average grain of the equivalent circle diameter determined from the area of the XY plane of the tabular grain Those having a diameter (R50) of 0.5 μm or more and 3 μm or less and satisfying the condition of R50 / Z> 5 are collected.

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

  The thickness of the metal or alloy layer is preferably 5 nm to 100 nm, more preferably 20 nm to 100 nm. Thereby, a bright pigment having an average thickness of preferably 5 nm to 100 nm, more preferably 20 nm to 100 nm is obtained. When it is 5 nm or more, it has excellent reflectivity and glitter, so the performance as a glitter pigment is enhanced, and when it is 100 nm or less, the increase in apparent specific gravity is suppressed and the dispersion stability of the glitter pigment is ensured. be able to.

  The release resin layer in the composite pigment base 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 release resin layer, for example, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polyacrylic acid, polyacrylamide, cellulose derivatives such as cellulose acetate butyrate, acrylic polymers, or modified nylon resins are preferable. A layer is formed by applying a solution of the above-mentioned one kind or a mixture of two or more kinds to a sheet-like substrate and drying. After coating, additives such as a viscosity modifier can be contained.

  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 may be smoothed by calendaring if necessary.

  Although the thickness of the resin layer for peeling is not specifically limited, Preferably it is 0.5 to 50 micrometer, More preferably, it is 1 to 10 micrometer. 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, It is preferable that they are 10 micrometers or more and 150 micrometers or less. 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 such a protective layer include a silicon oxide layer and a protective resin layer.

  The silicon oxide layer is not particularly limited as long as it contains silicon oxide, but it is preferably formed from a silicon alkoxide such as tetraalkoxysilane or a polymer thereof by a sol-gel method. A silicon oxide layer is formed by applying an alcohol solution in which 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 a cellulose derivative. Among these resins, it is preferably formed from a cellulose derivative such as polyvinyl alcohol or cellulose acetate butyrate. A layer is formed by applying an aqueous solution of one kind or a mixture of two or more kinds of the resins and drying. 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 to 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.

  As the composite pigment base material, a layer structure having a plurality of sequential laminated structures of the release resin layer, a metal or alloy layer, and a protective 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 substrate and the exfoliating resin layer immediately above the 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 one by one 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 base material is not particularly limited, but a liquid (solvent) is jetted onto the composite pigment base material, and the metal or alloy layer of the composite pigment base material after jetting is performed. A method of scraping and collecting the composite pigment raw material, a method of immersing the composite pigment raw material in a liquid, and an ultrasonic treatment at the same time as immersing in the liquid to perform a peeling treatment and a grinding treatment of the peeled composite pigment. The method of performing is preferred. In these methods, in addition to the peeled metal or alloy layer, the liquid used for the peeling treatment can also be recovered. Examples of the liquid (solvent) used in such a peeling treatment method include alkylene glycol ethers, lactone solvents, or mixtures thereof. The method for pulverizing and refining the peeled metal or alloy layer is not particularly limited, and may be a conventionally known method using a ball mill, a bead mill, an ultrasonic wave, a jet mill or the like.

  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 addition, in the ink using such a pigment, the resin derived from the release resin layer also has a function of imparting adhesiveness to the recording medium.

  The content of the glitter pigment in the glitter ink according to the present embodiment is preferably 0.5% by mass or more and 2.0% by mass or less. In addition, when the content of the glitter pigment in the glitter ink is 0.5% by mass or more and less than 1.7% by mass, the amount of ink that does not sufficiently cover the recording surface is ejected, so that the gloss of a half mirror is obtained. The surface, that is, the glossy feeling can be felt, but the texture can be recorded so that the background can be seen through, and the glossy surface with high glossiness is formed by ejecting an amount of ink that can sufficiently cover the recording surface. Can do. Therefore, for example, it is suitable for forming a half mirror image on a transparent recording medium or expressing a highly glossy glitter surface. Further, when the concentration of the glitter pigment in the glitter ink is 1.7% by mass or more and 2.0% by mass or less, the glitter pigment is randomly arranged on the recording surface, so that high gloss cannot be obtained, and the matte tone is not obtained. The bright surface can be formed. Therefore, it is suitable, for example, when a shielding layer is formed on a transparent recording medium.

1.3. Organic Solvent The glittering ink composition according to this embodiment is at least one selected from alkylene glycol ethers and lactones that are liquid at room temperature and normal pressure from the viewpoint of improving the fixability of a metallic gloss image to a recording medium. Preferably it contains seeds.

  Alkylene glycol ethers are ethylene based on aliphatic, double-bonded allyl and phenyl groups of methyl, n-propyl, i-propyl, n-butyl, i-butyl, hexyl, and 2-ethylhexyl. There are glycol ethers and propylene glycol ethers, which are colorless and have little odor and are liquid at room temperature. 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. Among these organic solvents, diether type alkylene glycol ethers are less reactive with glittering pigments than mono ether type alkylene glycol ethers because both hydroxyl groups are substituted. Therefore, when a bright pigment (for example, aluminum) that easily reacts with alcohol is used, it is preferable to use diether type alkylene glycol ethers.

  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 triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene group 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.

  The lactone is preferably a lactone having 6 or less carbon atoms, more preferably β-propiolactone, β-butyrolactone, γ-butyrolactone, γ-valerolactone, or ε-caprolactone.

  The alkylene glycol ethers and lactones that can be used in the glittering ink according to this embodiment preferably have a boiling point of 150 ° C. or higher, more preferably 180 ° C. or higher, under normal pressure.

  Further, the alkylene glycol ethers that can be used in the glitter ink composition according to the present embodiment have a vapor pressure at 20 ° C. of preferably 1 hPa or less, more preferably 0.7 hPa or less.

  By using alkylene glycol ethers that satisfy the conditions of high boiling point and low vapor pressure as described above, the burden of installing local exhaust equipment or exhaust gas treatment equipment is reduced, the work environment can be improved, and the surrounding environment can be improved. It is possible to reduce the environmental load.

  The glitter ink according to the present embodiment preferably contains at least one selected from alkylene glycol ethers and lactones as described above, and the content can be appropriately selected depending on printing characteristics. However, it is preferably 30% by mass or more and 95% by mass or less with respect to the total mass of the glitter ink.

  Further, the glittering ink according to this embodiment may further contain an organic solvent exemplified below in addition to the organic solvent exemplified above.

  Other organic solvents are preferably polar organic solvents, such as alcohols (eg, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, fluorinated alcohol), ketones (eg, acetone, methyl ethyl ketone, cyclohexanone, etc.) Carboxylic acid esters (eg, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, etc.), ethers (eg, diethyl ether, dipropyl ether, tetrahydrofuran, dioxane, etc.), etc. It is done.

1.4. Other Components Resin may be added to the glitter ink according to the present embodiment from the viewpoint of further improving the fixability of the metallic gloss image to the recording medium. Examples of the resin 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, and fiber resin (for example, Cellulose acetate butyrate, hydroxypropyl cellulose), polyvinyl butyral, polyacryl polyol, polyvinyl alcohol, polyurethane and the like.

  Among these resins, at least one selected from the group consisting of polyvinyl butyral, cellulose acetate butyrate, and polyacryl polyol is preferable, and cellulose acetate butyrate is more preferable. By adopting such a preferable configuration, it is possible to obtain preferable effects such as good rubbing resistance during drying, fixability, and high glitter.

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

  The resin content in the glitter ink according to the present embodiment is preferably 0.1% by mass or more and 10% by mass or less.

  The glitter ink according to the present embodiment may contain at least one kind of glycerin, polyalkylene glycol, or saccharide. In the case of adding one or more kinds of glycerin, polyalkylene glycol, or saccharide, the total addition amount is 0.1% by mass or more and 10% by mass or less based on the total mass of the glitter ink composition. It is preferable that 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 general formula (3).

_{HO- (C n H 2n O)} m -H ··· (3)
(In the above formula (3), n represents an integer of 1 to 5, and m represents an integer of 1 to 100.)
In the above formula, (C _n H _2n O) _m may be one 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 disaccharide, trisaccharide, and tetrasaccharide; or sugar alcohols that are derivatives thereof, reduced derivatives such as deoxyacid, aldonic acid, uronic acid, and the like. 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.

  A surfactant may be added to the glittering ink according to this embodiment. Examples of the surfactant that can be added include acetylene glycol surfactants. Specifically, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1- Hexin-3-ol and the like are listed, and commercially available products include Surfinol 104, 82, 465, 485, or TG (all available from Air Products and Chemicals. Inc.), Orphine STG, Orphine E1010 (Nisshin Chemical) Industrial Co., Ltd.), Nissan Nonion A-10R, A-13R (manufactured by NOF Corporation), Floren TG-740W, D-90 (manufactured by Kyoeisha Chemical Co., Ltd.), Emulgen A-90, A-60 (Kao Corporation) Company-made), Neugen CX-100 (Daiichi Kogyo Seiyaku Co., Ltd.) and the like. These polyoxyethylene derivatives may be added alone or in combination. Each surfactant, for example, by imparting volatilization suppression properties to the ink, prevents ink from evaporating in the tube that transports ink from the ink cartridge to the printer head and prevents solids from accumulating in the tube. It can be reduced.

  Furthermore, a liquid nonionic polyoxyethylene derivative may be added as a surfactant at room temperature and atmospheric pressure. Specific examples thereof include, for example, polyoxyethylene cetyl ethers such as Nissan Nonion P-208 (manufactured by NOF Corporation), which are polyoxyethylene alkyl ethers; Nissan Nonion E-202S, E-205S (NOF Corporation) Polyoxyethylene oleyl ethers such as Emulgen 106 and 108 (manufactured by Kao Corporation); Nissan nonions HS-204, HS-205 and HS which are polyoxyethylene alkylphenol ethers -206, HS-208 (manufactured by NOF Corporation) and other polyoxyethylene octylphenol ethers; sorbitan monocaprylates such as Nissan Nonion CP-08R (manufactured by NOF Corporation), which is a sorbitan monoester; Nissan Nonion LP- 20 Sorbitan monolaurate such as (manufactured by NOF Corporation); Polyoxyethylene sorbitan monostearate such as Nissan Nonion OT-221 (manufactured by NOF Corporation) which is a polyoxyethylene sorbitan monoester; Florene G- Polycarboxylic acid polymer activator such as 70 (manufactured by Kyoeisha Chemical Co., Ltd.); polyoxyethylene higher alcohol ethers such as Emulgen 707 and 709 (manufactured by Kao Corporation); Poem J-4581 (manufactured by Riken Vitamin Co., Ltd.) Tetraglycerin oleates such as: Adequol NP-620, NP-650, NP-660, NP-675, NP-683, NP-686 (manufactured by Asahi Denka Kogyo Co., Ltd.), etc .; Adekacol CS-141E, Aliphatics such as TS-230E (Asahi Denka Kogyo Co., Ltd.) Acid esters; Sorgen 30 (Sorbitan sesquioleate manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Sorbitan monooleate such as Sorgen 40 (Daiichi Kogyo Seiyaku Co., Ltd.); Sorgen TW-20 (Daiichi Kogyo Seiyaku Co., Ltd.) And polyethylene glycol sorbitan monolaurate such as Sorgen TW-80 (Daiichi Kogyo Seiyaku Co., Ltd.).

1.5. Method for producing glitter ink The glitter ink according to the present embodiment can be produced by a known conventional method. Specifically, the following technique can be employed. First, after mixing the above-mentioned glitter pigment and solvent, a pigment dispersion is prepared by a ball mill, a bead mill, an ultrasonic wave, a jet mill or the like, and adjusted so as to have desired ink characteristics. Subsequently, the remaining portion of the solvent and other additives (for example, a resin or a surfactant) are added to the obtained pigment dispersion with stirring, whereby a non-aqueous ink composition can be obtained.

  In addition, the composite pigment base may be sonicated in a solvent to obtain a composite pigment dispersion, and then mixed with a necessary ink solvent. Alternatively, the composite pigment base may be directly used for ink. The ink can be used as it is by sonication in a solvent. In order to adjust the solid content concentration in the ink, a conventionally known method such as pressure filtration or centrifugal separation can be used.

1.6. Physical Properties The glitter ink according to this embodiment preferably has a surface tension at 20 ° C. of 20 mN / m or more and 50 mN / m from the viewpoint of the balance between the printing quality and the reliability as an ink composition for inkjet. More preferably, it is at least 40 mN / m. The surface tension is measured by using an automatic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) by confirming the surface tension when the platinum plate is wetted with ink in an environment of 20 ° C. be able to.

  From the same point of view, the viscosity at 20 ° C. of the glittering ink composition according to this embodiment is preferably 2 mPa · s or more and 8 mPa · s or less, and preferably 2 mPa · s or more and 5.5 mPa · s or less. It is more preferable. The viscosity is measured by using a viscoelasticity tester MCR-300 (manufactured by Physica), increasing the Shear Rate to 10 to 1000 in an environment of 20 ° C., and reading the viscosity at Shear Rate 200. Can be measured.

2. Inkjet Recording Method The inkjet recording method according to this embodiment is characterized in that the above-described glitter ink droplets are ejected and the droplets are attached to the surface of a recording medium to record an image. According to the ink jet recording method according to this embodiment, since the above-described glittering ink composition is used, a recorded matter having a high-quality gloss image can be obtained.

  The recording medium used in the inkjet recording method according to the present embodiment is not particularly limited. For example, the recording medium may be plain paper, inkjet dedicated paper (matte paper), glass, plastic film (vinyl chloride, polyvinyl butyral, etc.), and a substrate. Various recording media such as a plastic, a film coated with a receiving layer, metal, and a printed wiring board can be used. The recording medium used in the ink jet recording method according to this embodiment is preferably a film from the viewpoint of using a non-aqueous ink composition. Specific examples of the film include polyvinyl chloride, polyethylene terephthalate, polyethylene, polyvinylidene chloride, polyvinyl alcohol, polyester, polycarbonate, polyacrylonitrile, cellophane, nylon, ethylene vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, and ethylene. -A methacrylic acid copolymer etc. are mentioned.

  Further, an ink receiving layer containing a resin may be formed on the outermost surface on the printing surface side of the film. Although it does not specifically limit as resin, For example, cellulose derivatives, such as a cellulose acetate butyrate (CAB) and a cellulose propionate (CP), a polyester resin, a polyurethane resin, a polyacryl resin, etc. are mentioned.

  The ink jet recording apparatus used in the ink jet recording method according to the present embodiment is not particularly limited, but a drop-on-demand ink jet recording apparatus is preferable. The drop-on-demand ink jet recording apparatus employs a piezoelectric element recording method in which recording is performed using a piezoelectric element disposed in a recording head, and heat generated by a heater of a heating resistance element disposed in the recording head. There are methods that employ a thermal jet recording method in which recording is performed using energy, and any recording method can be employed. In addition, since the non-aqueous ink composition according to the present embodiment has an advantage that it is inactive with respect to the discharge nozzle surface subjected to the ink repellent treatment, for example, an inkjet recording head having the discharge nozzle surface subjected to the ink repellent treatment. The ink jet recording method can be advantageously used in an ink jet recording method of discharging from a liquid crystal.

3. Examples Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to these examples. In the examples and comparative examples, “%” is based on mass unless otherwise specified.

3.1. Preparation of glitter pigment dispersion On a PET film with a film thickness of 100 μm, cellulose acetate butyrate (manufactured by ACROS ORGANICS, butylation rate 35-39%, weight average molecular weight 70000) 3.0% by mass and diethylene glycol diethyl ether (Japan) A resin layer thin film was formed on a PET film by uniformly applying a resin layer coating solution comprising 97% by mass of Emulsifier Co., Ltd. by a bar coating method and drying at 60 ° C. for 10 minutes.

  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 (The vacuum device company make, product name "VE-1010 type vacuum vapor deposition apparatus").

  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 glittering pigment dispersion having a time of 12 hours was prepared.

  The resulting bright pigment dispersion was filtered through a SUS mesh filter with 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. Thus, the glitter pigment dispersion was concentrated, and then the concentration of the glitter pigment dispersion was adjusted to obtain a glitter pigment dispersion having a concentration of 5% by mass.

  Then, using a flow type particle image analyzer (manufactured by Sysmex Corporation, product name “FPIA-3000S”), the diameter of the equivalent circle of the major axis (X direction) -minor axis (Y direction) plane of the resulting bright pigment is obtained. When 50% average particle diameter R50 and average particle diameter Rmax were measured, R50 = 1.03 μm and Rmax = 4.9 μm. Moreover, when the average film thickness Z (average value of 10 times measurement) of the obtained luster pigment was measured using the transmission electron microscope (The JEOL Co., Ltd. make, product name "JEM-2000EX"), Z was measured. = 0.02 µm. Furthermore, when R50 / Z was calculated based on the obtained measured values of R50 and Z, R50 / Z = 51.5. The particle size distribution value (CV value) was 44.0 as determined by the formula CV value = (standard deviation of particle size distribution / average value of particle diameter) × 100.

3.2. Preparation of glitter ink Using the glitter pigment dispersion prepared by the above method, glitter ink was prepared with the composition shown in Tables 1 and 2 (however, the numerical values in the table represent mass%). Specifically, various components shown in Tables 1 and 2 are mixed and dissolved to form an ink solvent, and then a bright pigment dispersion is added to the ink solvent, and then a magnetic stirrer is added at room temperature and normal pressure for 30 minutes. Was mixed and stirred to obtain a glitter ink containing a glitter pigment.

The materials used in the table are as follows.
Cellulose acetate butyrate (manufactured by ACROS ORGANICS, butylated rate of 35-39%, weight average molecular weight 70000)
・ Γ-Butyrolactone (manufactured by Kanto Chemical Co., Inc.)
・ Diethylene glycol diethyl ether (Nippon Emulsifier Co., Ltd.)
・ Tetraethylene glycol dimethyl ether (manufactured by Nippon Emulsifier Co., Ltd.)
・ Triethylene glycol monomethyl ether (manufactured by Junsei Co., Ltd.)
・ Tetraethylene glycol monobutyl ether (Nippon Emulsifier Co., Ltd.)
・ Propylene glycol (manufactured by Kanto Chemical Co., Ltd.)
・ Glycerin (manufactured by Kanto Chemical Co., Ltd.)
Paraloid B82 (product name, manufactured by Rohm and Haas, acrylic resin containing butyl methacrylate and ethyl acrylate, weight average molecular weight 120,000)
Paraloid B60 (product name, manufactured by Rohm and Haas, acrylic resin containing butyl methacrylate and methyl methacrylate, weight average molecular weight 50000)
・ Dimethyl succinate (manufactured by Kanto Chemical Co., Inc.)
P24N (product name, manufactured by Evonik Rohm, acrylic resin containing butyl methacrylate and methyl methacrylate, weight average molecular weight 180000)
・ Triacetin (manufactured by Daihachi Chemical Industry Co., Ltd.)
・ Tripropionin (manufactured by Tokyo Chemical Industry Co., Ltd.)
・ Tributyrin (Tokyo Chemical Industry Co., Ltd.)

3.3. Evaluation test of glitter ink 3.3.1. Ink Viscosity Measurement The viscosity at 20 ° C. of the glitter inks shown in Tables 1 and 2 was measured using a modular compact rheometer (manufactured by Anton Paar, model “PHYSICA MCR 300”). In addition, the value of the measured viscosity is a value when the shear rate is 200 S ⁻¹ at 20 ° C. The measurement results are also shown in Tables 1 and 2.

3.3.2. Glossiness measurement The glossiness prepared by the above method using an ink jet printer (model “SP-300V”, manufactured by J Roland DG Co., Ltd.) equipped with a print heater section and a dryer section whose temperature can be varied in the paper guide section. Fill the ink in the black row of the printer and print it solidly on a recording medium cut to A4 size (Sumitomo 3M Limited, product name “IJ-40”, polyvinyl chloride film for solvent inkjet printer). A record was obtained. The recording conditions were set so that the heater setting of the printer was “setting at which the temperature of the recording surface was 40 ° C.”. According to such a printer, after droplets of a non-aqueous ink composition are ejected and deposited on the recording medium, the droplets are allowed to pass through a heated print heater unit, and hot air (40 C.) can be obtained to obtain a recorded matter on which a metallic gloss image is recorded. Thereafter, the obtained recorded matter was left in a laboratory at room temperature (25 ° C.) for 5 hours.

  About the obtained image, the glossiness in 20 degree | times was measured using the glossiness meter (The product name "MULTITI Gloss 268" by Konica Minolta, Inc.), and it evaluated according to the following evaluation criteria. The evaluation results are also shown in Tables 1 and 2. Of the following evaluation criteria, “A” is a practically acceptable range.

A: 400 or more B: 300 or more and less than 399 C: 200 or more and less than 299 D: 199 or less

3.3.3. Evaluation Results According to Examples 1 to 5, by containing the compound represented by the general formula (1), the viscosity can be easily adjusted to be ejectable from the ink jet recording apparatus, and the recording is performed on the recording medium. It was found that the gloss of the printed image was excellent.

  According to Comparative Examples 1 to 12, various components were added so that the viscosity could be discharged from the ink jet recording apparatus, but the glossiness of the image recorded on the recording medium tends to decrease. I understood.

  The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

Claims (7)

A non-aqueous ink composition for inkjet, comprising a luster pigment, a compound represented by the following general formula (1), and an organic solvent.

(In the general formula (1), R ¹ , R ² and R ³ each independently represents an alkyl group having 1 to 3 carbon atoms.) In claim 1,
The non-aqueous ink composition for inkjet, wherein the compound represented by the general formula (1) is at least one selected from triacetin, propionin and tributyrin. In claim 1 or claim 2,
The non-aqueous ink composition for inkjet, wherein the content of the compound represented by the general formula (1) is 5% by mass or more and 40% by mass or less. In any one of Claims 1 thru | or 3,
The glitter pigment is a tabular grain,
When the major axis on the plane of the tabular grains is X, the minor axis is Y, and the thickness is Z,
The 50% average particle diameter R50 of the equivalent circle diameter determined from the area of the XY plane of the tabular grains is 0.5 μm or more and 3 μm or less, and satisfies the condition of R50 / Z> 5. Ink composition. In any one of Claims 1 thru | or 4,
The non-aqueous ink composition for inkjet, wherein the glitter pigment is aluminum or an aluminum alloy. In any one of Claims 1 thru | or 5,
The non-aqueous ink composition for inkjet, wherein the organic solvent contains at least one of alkylene glycol ethers and lactones. In any one of Claims 1 thru | or 6,
A non-aqueous ink composition for inkjet, having a viscosity at a measurement temperature of 20 ° C. of 2 mPa · s to 8 mPa · s.