Printing ink and printed material

Abstract

To provide a printing ink with a high brightness (L value) as well as superior image clarity, diffusivity, and weather resistance, and a printed material.SOLUTION: A printing ink contains a binder resin, a pigment and a liquid medium, where the binder resin includes an acrylic resin; the pigment includes a flaky lustrous pigment; the content of the acrylic resin in the total solid mass of the printing ink is 5-45 mass%; and the mass ratio of the acrylic resin to the flaky lustrous pigment is 25 / 75-45 / 55.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a printing ink and a printed matter.

[0002] More specifically, the present invention relates to a printing ink and a printed matter having glittering properties. [Background technology]

[0003] Generally, there are various types of sheets with metallic designs, such as those that have been subjected to metal deposition on a film, those that realize metallic luster by laminating polymers with different refractive indices to cause interference reflection of visible light, and those that are obtained by making ink using fine metal fragments and printing the ink on a film. Among them, the method of making ink using metal fragments as a pigment and printing the ink has attracted attention as a practical means because it is simple and low-cost. In the prior art, various methods have been used to increase the dispersibility of the metal fragments when making the ink, such as applying some kind of treatment to the metal surface of the metal fragments or selecting the type and functional group of the resin that serves as the ink binder (Patent Documents 1 and 2).

[0004] Patent Document 1 describes a high-brightness ink that imparts a metallic design and has excellent peel strength, and a laminate sheet that uses the ink and has a metallic design and the ductility required for molding. Meanwhile, Patent Document 2 describes an invention called a high-brightness gravure ink composition that can provide printed matter with high brightness without using aluminum foil or aluminum vapor deposition film and has high adhesion to plastic substrate films. However, even when using the inks described in Patent Documents 1 and 2, it is difficult to obtain printed matter with the metallic luster and brilliance of a metal vapor-deposited film, such as mirror reflection, and there are problems such as a dulling of the inherent metallic luster and a flickering of the printed surface. Furthermore, Patent Document 3 discloses a glittering paint that requires the combined use of expensive gold, silver, and copper, but a formulation that does not require the combined use of gold, silver, and copper is desired.

[0005] In addition to the conventional sensory evaluation of glitter, it is possible to quantify the brightness of the sample surface and the light reflectance in terms of lightness (L value). In other words, the brighter the sample surface is and the higher the reflectance, the higher the lightness (L value). In addition, indexes have been proposed, such as image clarity, which indicates how clearly and undistorted the image of an object reflected on the sample surface is, and diffusion, which is a numerical value of the angular distribution of reflected light intensity, which indicates how much light is reflected in which direction when light is incident. In other words, the dullness of the sense of luminance and the fluctuation of the printed surface as described above are reflected in image clarity and diffusion.

[0006] In addition, sheets and printed matter having the above-mentioned metallic design are expected to be used in various indoor and outdoor environments, and it is necessary to impart weather resistance to the printed matter in order to withstand such environments. Patent Document 1 describes that the binder resin contains at least one of a carboxyl group, a phosphate group, a sulfonic acid group, a nitrate group, an amino group, and / or a salt thereof. Patent Document 2 describes that the binder resin contains an acid-modified vinyl chloride-vinyl acetate copolymer resin having an acid value of 2 mgKOH / g or more, and a polyurethane resin. Such resins are likely to deteriorate in high temperature and humidity environments or environments where external light is directly or indirectly taken in, which is expected to result in a decrease in brilliance (glossiness), a decrease in adhesion, and delamination. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2004-35849 A [Patent Document 2] Patent Publication No. 2022-54590 [Patent Document 3] JP 2006-169268 A Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a printing ink, a printed matter, and a laminate that have high lightness (L value) and excellent image clarity, diffusion and weather resistance. [Means for solving the problem]

[0009] As a result of extensive research into the above problems, the present inventors have found that the above problems can be solved by using the packaging material described below, and have thus completed the present invention.

[0010] [1] A printing ink containing a binder resin, a pigment and a liquid medium, The binder resin includes an acrylic resin, The pigment includes a flake-like luster pigment, The content of the acrylic resin in the total solid content mass of the printing ink is 5 to 45 mass%, A printing ink, wherein a mass ratio of the acrylic resin to the flaky glittering pigment is 25 / 75 to 45 / 55.

[0011] [2] The printing ink according to [1], wherein the flake-like photoluminescent pigment contains aluminum.

[0012] [3] A printing ink according to claim [1] or [2], wherein the content of acrylic resin in the total mass of the binder resin is 80 mass% or more.

[0013] [4] A printing ink according to any one of [1] to [3], wherein the acid value of the acrylic resin is 300 mg KOH / g or less.

[0014] [5] The printing ink according to any one of [1] to [4], wherein the acrylic resin has a glass transition temperature of 30 to 130°C.

[0015] [6] The printing ink according to any one of [1] to [5], wherein the weight-average molecular weight of the acrylic resin is 10,000 to 100,000.

[0016] [7] A printing ink according to any one of [1] to [6], wherein the liquid medium contains an organic solvent.

[0017] [8] A printing ink according to any one of [1] to [7], wherein the combined mass ratio of the ester-based organic solvent and the ketone-based organic solvent in the total mass of the liquid medium is 75 mass% or less.

[0018] [9] A printing ink according to any one of [1] to [8], wherein the mass ratio of the alcohol-based organic solvent to the total mass of the liquid medium is 40 mass% or more.

[0019]

[10] A printed matter having a substrate and a glossy printing layer made of the printing ink according to any one of [1] to [9].

[0020]

[11] The printed matter according to

[10] , further comprising a colored printed layer.

[0021]

[12] The printed matter according to

[10] or

[11] , having a 20° gloss value of 700 or more measured from the substrate side.

[0022]

[13] A method for producing a printed matter having a substrate and a glossy printed layer made of a printing ink, comprising: The printing ink comprises a binder resin, a pigment, and a liquid medium; The binder resin includes an acrylic resin, The pigment includes a flake-like luster pigment, The content of the acrylic resin in the total solid content mass of the printing ink is 5 to 45 mass%, The mass ratio of the acrylic resin to the flaky glittering pigment is 25 / 75 to 45 / 55; A method for producing a printed matter, comprising a step of forming a glossy printed layer by intaglio printing the printing ink on the substrate. Effect of the Invention

[0023] The present invention makes it possible to provide a printing ink, a printed matter, and a laminate that have high lightness (L value) and excellent image clarity, diffusion, and weather resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The embodiment of the present invention will be described in detail below with reference to examples, but the matters described below are examples or representative examples of the embodiment of the present invention, and the present invention is not limited to these contents as long as it does not deviate from the gist of the invention. Hereinafter, "printing ink" may be simply expressed as "ink", but this has the same meaning.

[0025] The present invention relates to a printing ink containing a binder resin, a pigment, and a liquid medium, the binder resin containing an acrylic resin, the pigment containing a flake-like glittering pigment, and a content of the acrylic resin in the total solid content mass of the printing ink being 5 to 45 mass%, By using a printing ink in which the mass ratio of the acrylic resin to the flaky luster pigment is 25 / 75 to 45 / 55, it is possible to provide printed matter with high brightness (L value) and excellent image clarity, diffusion and weather resistance.

[0026] <Binder resin> The ink of the present invention contains a binder resin, and the binder resin contains an acrylic resin. The binder resin refers to the binding resin in the ink of the present invention, and is preferably a thermoplastic resin soluble in an organic solvent. By containing the binder resin, not only does it become easier to hold the glittering pigment in the coating film, but also the adhesion between the ink and the substrate is improved. In addition, since the acrylic resin has both transparency and weather resistance, the use of the acrylic resin can satisfy all of the lightness (L value), image clarity, diffusion degree, and weather resistance. Furthermore, depending on the substrate, the solvent used may cause the substrate to swell and reduce its luster. However, since acrylic resins are soluble in alcohol-based solvents, which have relatively little effect on substrates, the substrate can be selected from a wider range of substrates.

[0027] In the present invention, the content of the binder resin in the total solid content of the printing ink is preferably 5% by mass or more and 55% by mass or less, more preferably 25 to 50% by mass, and even more preferably 30 to 45% by mass. By being in the above range, the ink has good adhesion to the substrate, and good brightness, image clarity, and diffusivity.

[0028] <Acrylic resin> In the present invention, "acrylic resin" refers to a polymer having an acrylic monomer as a constituent unit. In addition, "acrylic monomer" refers to a monomer having an acrylic group or a methacryloyl group, and "methacrylic and acrylic" may be collectively abbreviated as "(meth)acrylic". In addition, "methacrylate and acrylate" may be collectively abbreviated as "(meth)acrylate".

[0029] The content of the acrylic resin in the total solid content mass of the printing ink is 5 to 45 mass%, preferably 10 to 44 mass%, more preferably 20 to 43 mass%, and even more preferably 25 to 42 mass%. By being in this range, the adhesion to the substrate, image clarity, diffusion degree, and weather resistance are improved. Furthermore, the content of the acrylic resin in the total solid content mass of the binder resin is preferably 80 mass% or more, more preferably 85 mass% or more, and even more preferably 90 mass% or more. By being in this range, the range of substrate selection is broadened as described above, and weather resistance is improved.

[0030] The acid value of the acrylic resin is preferably 300 mgKOH / g or less, more preferably 270 mgKOH / g or less, and even more preferably 240 mgKOH / g or less. When the acid value is 300 mgKOH / g or less, the adhesion to the substrate is good. Also, when the acid value is 240 mgKOH / g or less, the weather resistance may be good.

[0031] The glass transition temperature (Tg) of the acrylic resin is preferably 30 to 130° C., more preferably 35 to 110° C., and even more preferably 40 to 90° C. If the glass transition temperature is 30° C. or higher, moldability is good, and if it is 130° C. or lower, the surface hardness increases and scratch resistance is good. Also, if it is 110° C. or lower, weather resistance is good.

[0032] The weight average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 100,000, and more preferably 20,000 to 80,000. By making the weight average molecular weight 10,000 or more, moldability and surface hardness are both excellent, and weather resistance is also excellent. By making the mass average molecular weight 100,000 or less, resistance such as chemical resistance required for printing ink is excellent.

[0033] As the acrylic resin, commercially available products such as Joncryl 690, Joncryl 819, Joncryl 678, and Joncryl 682 (manufactured by BASF), BR100, BR102, BR115, and BR605 (manufactured by Mitsubishi Chemical Corporation) can be used.

[0034] (Combined Resin) In the present invention, it is possible to use resins other than acrylic resins as the binder resin. The binder resin is not limited to the following, but examples thereof include urethane resins, cellulose resins, polyamide resins, vinyl chloride copolymer resins, rosin resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, chlorinated polypropylene resins, styrene resins, dammar resins, styrene-maleic acid copolymer resins, polyester resins, alkyd resins, terpene resins, phenol-modified terpene resins, ketone resins, cyclized rubbers, chlorinated rubbers, butyral, polyacetal resins, petroleum resins, and modified resins thereof. These resins can be used alone or in combination of two or more.

[0035] In the binder resin, the mass ratio of the acrylic resin to the other resin used in combination is preferably 100:0 to 80:20, more preferably 100:0 to 85:15, and further preferably 100:0 to 90:10.

[0036] <Pigments> The printing ink of the present invention contains a pigment, and the pigment contains a flaky glittering pigment. The flaky glittering pigment is preferably one derived from a metal vapor deposition film. When the glittering pigment is flaky, the pigment is easily oriented and diffuse reflection is less likely to occur, resulting in good image clarity and diffusion.

[0037] The content of the flaky luster pigment in the total solid content mass of the printing ink is preferably 55 to 80 mass%, more preferably 57 to 75 mass%, and more preferably 58 to 70 mass%. By being in this range, the brightness, image clarity, and diffusion degree are improved. Furthermore, the content of the flaky luster pigment in the total pigment mass is preferably 80 mass% or more, more preferably 85 mass% or more, and even more preferably 90 mass% or more, and may be 100%. By being in this range, the brightness, image clarity, and diffusion degree are improved.

[0038] The average particle size of the flaky luster pigment used in the present invention is preferably 10 μm or less. The average particle size is preferably 1 to 10 μm, more preferably 3 to 10 μm, and even more preferably 5 to 8 μm. If the average particle size of the flaky luster pigment is 1 μm or more, the lightness (L value) of the ink coating film tends to be high, and if it is 10 μm or less, the orientation of the flaky luster pigment tends to be uniform, so diffuse reflection is unlikely to occur, and image clarity and diffusion degree are good.

[0039] The average thickness of the flaky luster pigment used in the present invention is preferably 100 nm or less, and more preferably 30 nm or less. When the thickness is within this range, the orientation of the flaky luster pigment is easily aligned, making it difficult for diffuse reflection to occur and improving image clarity and diffusion.

[0040] The flaky bright pigment used in the present invention can be made of metals such as aluminum, indium, silver, copper, nickel, titanium, chromium, etc., or alloys containing these metals. Aluminum is preferred because it is inexpensive and provides good lightness (L value) and image clarity.

[0041] The flake-like bright pigment is obtained by peeling off a metal thin film (hereinafter also referred to as a vapor deposition film) formed by vacuum-depositing the metal or its alloy on a plastic film from the plastic film, and crushing and stirring the peeled metal thin film. This makes it possible to form a very thin film that is easily uniformly oriented, resulting in good lightness (L value), image clarity, and diffusivity. The metal vapor deposition film is not limited, and may be a vapor deposition film obtained by vacuum deposition using, for example, a resistance heating method, a high-frequency induction heating method, or an electron beam heating method.

[0042] When the printed matter requires resistance such as water resistance and alkali resistance, it is preferable to use a flaky luster pigment that is surface-coated with a protective film such as silica. Since resistance is significantly improved, it is preferable to use them according to the purpose.

[0043] The pigment may include pigments other than the above-mentioned flaky luster pigments, and may include leafing or non-leafing aluminum powder obtained by crushing aluminum metal while spreading it, inorganic pigments, organic pigments, dyes, etc. Examples of inorganic pigments include yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine, cobalt blue, etc., and examples of organic pigments include soluble azo-based, insoluble azo-based, azo-based, phthalocyanine-based, halogenated phthalocyanine-based, anthraquinone-based, anthanthrone-based, dianthraquinonyl-based, anthrapyrimidine-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethine azo-based, flavanthrone-based, diketopyrrolopyrrole-based, isoindoline-based, indanthrone-based, and other pigments. In addition, any pigment designated by a CI pigment number in the Color Index can be used.

[0044] The mass ratio of the acrylic resin to the above-mentioned flaky glittering pigment in the printing ink is 25 / 75 to 45 / 55, more preferably 30 / 70 to 44 / 56, and even more preferably 35 / 65 to 43 / 57. By being in the range of 25 / 75 to 45 / 55, it is possible to improve image clarity and diffusion while maintaining the ink's stability over time and printability.

[0045] <Alkoxysilane> The printing ink of the present invention may contain an alkoxysilane. The alkoxy group of the alkoxysilane undergoes hydrolysis to become silanol, which forms a hydrogen bond with the hydroxyl group on the surface of the flaky luster pigment. Furthermore, dehydration condensation occurs due to the drying heat during printing, and the flaky luster pigment is bonded to the flaky luster pigment through a stronger chemical bond. As a result, the compatibility of the flaky luster pigment with the binder resin decreases, and the flaky luster pigment is more likely to be oriented in the process of forming a dry film, which is thought to improve image clarity and diffusion. Examples of alkoxysilanes include methoxysilane, ethoxysilane, etc. Silane coupling agents having a reactive group such as an epoxy group or a methacryl group are also suitable.

[0046] <Liquid medium> The printing ink of the present invention contains a liquid medium. The liquid medium may be any liquid medium capable of dissolving the binder resin, and may be any of organic solvents, water, and mixtures thereof, but it is preferable that the liquid medium contains an organic solvent from the viewpoint of drying properties. Of 100% by mass of the liquid medium, the organic solvent is preferably contained in an amount of 80 to 100% by mass, more preferably 90 to 100% by mass, and even more preferably 95 to 100% by mass.

[0047] <Organic solvent> As the organic solvent that can be used in the present invention, known organic solvents such as aromatic organic solvents such as toluene and xylene, ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, ester organic solvents, and alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol monopropyl ether, and propylene glycol monomethyl ether can be used, and they may be mixed and used. Among them, organic solvents that do not contain aromatic organic solvents such as toluene and xylene (non-toluene organic solvents) are preferable from the viewpoint of environmental compatibility. In addition, ketone organic solvents and ester organic solvents may cause the substrate to swell and deteriorate, resulting in a decrease in the brilliance of the printed matter, so that the mass ratio of the ester organic solvent and the ketone organic solvent in the liquid medium is preferably 75 mass% or less, more preferably 65 mass% or less, and even more preferably 55 mass% or less. In this case, "mass% or less" also includes the case of 0. On the other hand, alcohol-based organic solvents are preferred because they are less likely to swell or deteriorate the substrate, and the mass ratio of the alcohol-based organic solvent in the liquid medium is preferably 15 mass% or more, more preferably 40 mass% or more, more preferably 50 mass% or more, and even more preferably 60 mass% or more. In addition, when it is within the above range, the brightness, image clarity, and diffusion degree tend to be improved.

[0048] In addition, in order to achieve brilliance in the present invention, the orientation of the brilliant pigment when the ink coating dries and hardens is important, and it is believed that the drying property (boiling point) of the organic solvent contained in the ink also has an effect on this. The organic solvent referred to here includes the organic solvent used to dissolve the binder resin and disperse the pigment. In particular, when the pigment ratio of the ink is high, it is preferable to contain both an organic solvent with a low boiling point (above 100°C or less) (fast-melting solvent) and an organic solvent with a high boiling point (above 100°C or more) (slow-melting solvent) from the viewpoint of preventing blurring of the printed surface by not drying too quickly and from the viewpoint of properly orienting the glittering pigment and improving the glittering. If the organic solvent in the ink is only a fast-melting solvent, it is possible to use a slow-melting solvent as a dilution solvent during printing, but from the viewpoint of solubility when diluting the ink, it is preferable to contain both a fast-melting solvent and a slow-melting solvent in the ink before dilution. The mass ratio of the fast-melting organic solvent to the slow-melting organic solvent is preferably 50:50 to 90:10, and more preferably 60:40 to 80:20.

[0049] Examples of fast-flowing solvents include methyl ethyl ketone, ethyl acetate, methanol, ethanol, n-propanol, isopropanol, etc. Examples of slow-flowing solvents include methyl isobutyl ketone, n-propyl acetate, isobutyl acetate, n-butanol, ethylene glycol monopropyl ether, propylene glycol monomethyl ether, toluene, xylene, etc.

[0050] <Additives> The printing ink of the present invention may contain known additives as appropriate. If necessary, known additives such as pigment derivatives, dispersants, wetting agents, adhesion aids, leveling agents, defoamers, antistatic agents, trapping agents, antiblocking agents, wax components, isocyanate-based curing agents, and silane coupling agents may be used.

[0051] <Ink manufacturing> The printing ink of the present invention can be produced, for example, by dispersing / mixing a binder resin and a pigment in a liquid medium.

[0052] The viscosity of the ink produced by the above method is preferably in the range of 40 to 500 cps at 25°C using a Brookfield viscometer. More preferably, it is 50 to 350 cps. This viscosity range corresponds to a viscosity of about 9 to 40 seconds using a Zahn cup #4. The viscosity of the ink can be adjusted by appropriately selecting the types and amounts of the raw materials used, such as the amounts of the binder resin, liquid medium, etc.

[0053] <Base material> The substrate that can be used for the printed matter of the present invention is not particularly limited, but a plastic substrate is preferred. For example, polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polycarbonate, and polylactic acid, polystyrene, polystyrene-based resins such as acrylonitrile-styrene copolymer (AS) resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, and acrylonitrile-ethylene-styrene copolymer (AES), acrylic, nylon, polyamide, polyvinyl chloride, polyvinylidene chloride, or a film-like substrate made of a composite material thereof can be mentioned. Among them, acrylic, polycarbonate, and co-extruded resins of acrylic and polycarbonate are preferred. The substrate may be coated with polyvinyl alcohol or the like, or may be surface-treated, such as corona discharge treatment.

[0054] <Print> The printing method for the ink of the present invention is not particularly limited, and examples thereof include letterpress printing, lithographic printing, intaglio printing, and stencil printing. Among these, intaglio printing is preferred, and examples thereof include gravure printing and flexographic printing, and gravure printing is preferred.

[0055] <Gravure printing> (Photogravure version) In the gravure printing, the gravure plate is a metal cylinder, and recesses are created in each color by engraving, etching, or laser. There are no restrictions on the use of engraving and laser, and they can be set arbitrarily according to the pattern. Lines per page are appropriately set from 75 to 350 lines, and the higher the line number, the finer the printing. The thickness of the printing layer is preferably 0.1 μm to 100 μm.

[0056] (printing machine) In a gravure printing press, one printing unit is equipped with the gravure plate and doctor blade. There are many printing units, and each unit has an oven drying unit. Printing is performed by rotary printing, and a roll-to-roll printing method is used. The type of plate and the type of doctor blade are appropriately selected according to the specifications.

[0057] <Printed material> One embodiment of the present invention is a glittering printed matter having a plastic film substrate and a glittering printed layer made of the printing ink of the present invention. A glossy printed matter can be obtained by printing the printing ink of the present invention on a plastic film substrate and then thoroughly drying it to remove volatile components such as organic solvents. The thickness of the glittering print layer is preferably 0.1 to 5 μm, and more preferably 0.1 to 3 μm. When the thickness is 0.1 μm or more, the ink film properties are good, and when it is 5 μm or less, diffuse reflection is less likely to occur and glittering properties are good.

[0058] One embodiment of the present invention is a glittering printed matter having a plastic film substrate, a colored printed layer, and a glittering printed layer made of the printing ink of the present invention.

[0059] <Colored printing layer> The colored printed layer is provided to enhance the design of the glossy printed layer, and may be formed by printing ink, but is preferably a printed layer by gravure printing. It is also preferable that the colored printed layer is colored to such an extent that it does not interfere with the glossiness of the glossy printed layer. The colored printed layer is preferably located between the plastic film substrate and the glossy printed layer.

[0060] The printed layer preferably has a 20° gloss value measured from the substrate side of at least 700, more preferably at least 800, even more preferably at least 900, and particularly preferably at least 1000. When the 20° gloss value measured from the substrate side is at least 700, a glossy printed matter having high brightness and excellent image clarity and diffusion can be obtained.

[0061] <Laminate> One embodiment of the present invention is a laminate having a glossy printed layer made of the printing ink of the present invention on a plastic film substrate 1, an adhesive layer made of an adhesive provided on the glossy printed layer, and a substrate 2 bonded to the laminate. Other configurations include, but are not limited to, the following: Base material 1 / Colored printing layer / Glitter printing layer / Adhesive layer / Substrate 2 Surface protective layer / base material 1 / colored printing layer / glitter printing layer / adhesive layer / base material 2 Surface protective layer / colored printing layer / base material 1 / glitter printing layer / adhesive layer / base material 2 Base material 1 / Glitter printing layer / Colored printing layer / Adhesive layer / Substrate 2 EXAMPLES

[0062] The present invention will be described in detail below with reference to examples, but the following embodiments are merely examples of the present invention and the present invention is not limited to these examples. Note that parts and % in the present invention represent parts by mass and % by mass unless otherwise noted.

[0063] (Acid value) The acid value is the number of milligrams of potassium hydroxide required to neutralize the acid groups contained in 1 g of resin. Both were measured according to JIS K0070.

[0064] (glass transition temperature) The glass transition temperature (Tg) was determined according to the method described in JIS K0129. Specifically, it was determined by a DSC (differential scanning calorimeter). The measurement device used was a Rigaku Corporation DSC8231, with a measurement temperature range of -70 to 150°C, a heating rate of 10°C / min, and the midpoint between the end temperature and the end temperature of endothermic heat based on the glass transition in the DSC curve was taken as the glass transition temperature.

[0065] (Weight average molecular weight) The weight average molecular weight (Mw) was determined as a polystyrene-equivalent molecular weight by measuring the molecular weight distribution using a GPC (gel permeation chromatography) device (Shodex GPC System-21, manufactured by Showa Denko KK).

[0066] (Average particle size and average thickness of glitter pigment) The average particle size and average thickness of the luster pigment were observed using a scanning electron microscope (JSM-6390LA) manufactured by JEOL Ltd., and the average particle size and film thickness of the luster pigment were measured at four points on the obtained image, and the average values ​​were calculated.

[0067] (Example 1) [Production of printing ink S1] 2.1 parts of acrylic resin 1 was dissolved in 65.3 parts of isopropanol (hereinafter also referred to as IPA), and 32.6 parts of aluminum paste A (vapor-deposited aluminum: average particle diameter 8 μm, average thickness 25 nm, flake-like, liquid medium: propylene glycol monomethyl ether, solid content 10% by mass) was mixed to obtain printing ink S1.

[0068] (Examples 2 to 26, Comparative Examples 1 to 6) [Production of printing inks S2 to S26, R1 to R6] Printing inks S2 to S26 and R1 to R6 were obtained in the same manner as in the production of printing ink S1, except that the raw materials and blending ratios were changed to those shown in Tables 1 and 2.

[0069] The abbreviations in Tables 1 and 2 are as follows: Acrylic resin 1: Acid value 280mgKOH / g, Tg 80℃, Mw 80000 Acrylic resin 2: Acid value 228mgKOH / g, Tg 60℃, Mw 50000 Acrylic resin 3: Acid value 75mgKOH / g, Tg 57℃, Mw 14500 Acrylic resin 4: Acid value 0mgKOH / g, Tg 50℃, Mw 55000 Acrylic resin 5: Acid value 230mgKOH / g, Tg 134℃, Mw 14000 Acrylic resin 6: Acid value 215mgKOH / g, Tg 85℃, Mw 8500 Acrylic resin 7: Acid value 0mgKOH / g, Tg 20℃, Mw 360000 Acrylic resin 8: Acid value 0mgKOH / g, Tg 105℃, Mw 120000 Acrylic resin 9: Acid value 0mgKOH / g, Tg50℃, Mw80000 Acrylic resin 10: Acid value 238mgKOH / g, Tg 56℃, Mw 1700 Vinyl chloride-vinyl acetate copolymer resin: Acid value 5.8mgKOH / g, Tg 70℃, Mw 69000 Urethane resin: Acid value 30mgKOH / g, Tg30℃, Mw45000 Indium paste: Leaf Powder 49CJ-1120 (manufactured by Oike Kogyo Co., Ltd., thin flake-shaped glitter pigment derived from metal vapor deposition film, average particle size 1 μm or less, average thickness 10 to 100 nm, liquid medium: propylene glycol monomethyl ether, solid content 20%) Silica-coated aluminum paste: EMRS-710 (manufactured by Toyo Aluminum, flake-like luster pigment derived from metal deposition film, average particle size 10 μm, average thickness 30 nm or less, liquid medium: propylene glycol monomethyl ether, solid content 10%) Aluminum paste B: 0231T-N (manufactured by Toyo Aluminum, average particle size 8 μm, average thickness 500 nm, not flaky, liquid medium: n-propyl acetate, solid content 60%) ·PGM: Propylene glycol monomethyl ether MEK: Methyl ethyl ketone

[0070] <Production of Printed Matter> The printing inks S1 to S26 and R1 to R6 obtained above were printed on an acrylic film (Technoloy, manufactured by Sumitomo Chemical Co., Ltd.) with a thickness of 75 μm at a printing speed of 120 m / min using a gravure plate (fine) with a stylus angle of 140 degrees and a screen line count of 250 lines / inch to obtain a printed matter. Note that S22 to S24 are examples with different film thicknesses of the luminous printing layer, and the coating amount was adjusted to achieve a predetermined film thickness.

[0071] <20° Gloss> From the substrate side of the printed matters produced in the above Examples and Comparative Examples, the 20° gloss value was measured using a surface reflection analyzer RA-532H manufactured by Canon Inc. The results are shown in Tables 1 and 2. The numerical values in the tables are as follows. 5: 1000 or more 4: 900 or more and less than 1000 3: 800 or more and less than 900 2: 700 or more and less than 800 1: Less than 700

[0072] <Performance Evaluation> The following evaluations were performed using the printed matters of the inks obtained in the above Examples and Comparative Examples. The evaluation results are shown in Tables 1 and 2.

[0073] <L value> From the substrate side of the printed matters produced in the above Examples and Comparative Examples, the L value was measured using a portable integrating sphere spectrocolorimeter Ci64 manufactured by X-Rite Inc. The evaluation criteria are shown below. In this evaluation, a high L value indicates that the printed matter has high lightness, a bright appearance, and a high brightness feeling. 5: 85 or more 4: 80 or more and less than 85 3: 70 or more and less than 80 2: 50 or more and less than 70 1: Less than 50 The evaluation that can be used in practice is 3 or more.

[0074] <Mapping Property> Image clarity was measured from the substrate side of the printed matter produced in the above Examples and Comparative Examples using a Canon surface reflection analyzer RA-532H. The evaluation criteria are shown below. In this evaluation, high image clarity indicates that the image reflected on the surface of the printed matter appears clearer and less distorted. 5: 85% or more 4: 80% to less than 85% 3: 70% to less than 80% 2: 50% to less than 70% 1: Less than 50% A rating of 3 or above is considered practically usable.

[0075] <Dissemination rate> The degree of diffusion was measured from the substrate side of the printed matter produced in the above Examples and Comparative Examples using a surface reflection analyzer RA-532H manufactured by Canon Inc. The evaluation criteria are shown below. The degree of diffusion is smaller as the reflected light has a stronger regular reflection and the diffusion is smaller, which indicates that the degree of diffusion is better in the present invention. Less than 5:2 4:2 or more and less than 3 3:3 or more and less than 4 2:4 or more and less than 5 1:5 or more A rating of 3 or above is considered practically usable.

[0076] <Weather resistance> The printed matter produced in the above Examples and Comparative Examples was subjected to a weather resistance test using an accelerated weather resistance tester (xenon weather meter), and the printed matter after the test was visually evaluated from the substrate side. Test conditions: Black panel temperature 63°C, humidity 50% (relative humidity), irradiance 180W / m 2 (300nm~400nm), continuous irradiation, water spray time 12 minutes / 60 minutes irradiation 5: No change 4: The coating turns slightly yellow or white 3: The coating turns yellow or white 2: Gaps are observed between the substrate and the coating 1: Cracks appear on the coating A rating of 3 or above is considered practically usable.

[0077] [Table 1]

[0078] [Table 1]

[0079] [Table 2]

[0080] From the above results, it was found that the use of the printing ink of the present invention can achieve the objective of providing a printing ink with high lightness (L value) and excellent image clarity, diffusion and weather resistance, as well as a printed matter. In contrast, the comparative examples did not satisfy the evaluation criteria for at least one of lightness (L value), image clarity, diffusion and weather resistance.

Claims

1. A printing ink comprising a binder resin, a pigment and a liquid medium, The binder resin includes an acrylic resin, The pigment includes a flake-like luster pigment, The content of the acrylic resin in the total solid content of the printing ink is 5 to 45% by mass, A printing ink, wherein a mass ratio of the acrylic resin to the flaky glittering pigment is 25 / 75 to 45 / 55.

2. 2. The printing ink according to claim 1, wherein the flake-like luster pigment comprises aluminum.

3. 3. The printing ink according to claim 1, wherein the content of the acrylic resin in the total mass of the binder resin is 80 mass% or more.

4. 3. The printing ink according to claim 1, wherein the acrylic resin has an acid value of 300 mg KOH / g or less.

5. 3. The printing ink according to claim 1, wherein the acrylic resin has a glass transition temperature of 30 to 130°C.

6. 3. The printing ink according to claim 1, wherein the weight average molecular weight of the acrylic resin is from 10,000 to 100,000.

7. 3. A printing ink according to claim 1, wherein the liquid medium comprises an organic solvent.

8. 3. The printing ink according to claim 1, wherein the combined mass ratio of the ester-based organic solvent and the ketone-based organic solvent to the total mass of the liquid medium is 75 mass % or less.

9. 3. The printing ink according to claim 1, wherein the mass ratio of the alcohol-based organic solvent to the total mass of the liquid medium is 40 mass% or more.

10. A printed matter comprising a substrate and a glittering printed layer comprising the printing ink according to claim 1.

11. The printed matter according to claim 10, further comprising a colored printed layer.

12. The printed matter according to claim 10 or 11, which has a 20° gloss value of 700 or more as measured from the substrate side.

13. A method for producing a printed matter having a substrate and a glittering printed layer made of a printing ink, comprising: The printing ink comprises a binder resin, a pigment, and a liquid medium; The binder resin includes an acrylic resin, The pigment includes a flake-like luster pigment, The content of the acrylic resin in the total solid content of the printing ink is 5 to 45% by mass, The mass ratio of the acrylic resin to the flaky glittering pigment is 25 / 75 to 45 / 55; A method for producing a printed matter, comprising a step of forming a glossy printed layer by intaglio printing the printing ink on the substrate.

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