Laminate and manufacturing method thereof

Abstract

The present invention provides a laminate having excellent laminate appearance (free from streaky stains and ink loss) and laminate strength, and a method for producing the same. [Solution] A laminate having a substrate 1, a printing layer, an adhesive layer, and a substrate 2 in this order, wherein the printing layer contains an acrylic resin and a compound (A), the compound (A) contains at least one compound selected from the group consisting of an acetylene-based compound, an alcohol alkoxylate-based compound, and a siloxane-based compound, and the content of the acrylic resin is 5% by mass or more in 100% by mass of the printing layer.

Description

[Technical Field]

[0001] The present invention relates to a laminate and a method for producing the same. [Background technology]

[0002] Gravure printing and flexographic printing are widely used to impart beauty and functionality to printed materials. However, in recent years, the performance requirements for printing inks have become more diverse year by year due to the diversification of packaging materials and the advancement of packaging technology, as well as efforts to address environmental issues from a legal perspective. In order to reduce the environmental impact, the use of water-based printing inks has progressed rapidly, and ensuring performance in water-based inks has become an issue, with the entire industry working to improve printability and printing effectiveness.In particular, because water-based inks contain a large amount of water, there have been issues with poor drying during printing, resulting in reduced laminate strength and poor appearance of the laminated product.

[0003] Patent Document 1 describes a laminate obtained by printing an ink containing a water-based acrylic resin on a plastic film and then laminating it. However, because the water-based acrylic ink does not contain an acetylene-based compound, an alcohol alkoxylate-based compound, or a siloxane-based compound, there is a concern that the appearance of the laminate may be deteriorated. Patent Document 2 describes a laminate obtained by printing an ink containing a water-based urethane resin and a water-soluble acrylic resin on a plastic film and then laminating the printed layer. However, because the solid content of the water-soluble acrylic resin in the printed layer of the laminate is less than 5% by mass, there is a concern that the laminate strength and appearance may be reduced. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-155694 [Patent Document 2] Patent Publication No. 2021-63189 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a laminate having excellent laminate appearance (free from streaky stains and ink loss) and laminate strength, and a method for producing the same. [Means for solving the problem]

[0006] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using the packaging material described below, and have thus completed the present invention.

[0007] That is, the present invention is a laminate having a substrate 1, a printing layer, an adhesive layer, and a substrate 2 in this order, the printed layer contains an acrylic resin and a compound (A), the compound (A) contains at least one compound selected from the group consisting of an acetylene-based compound, an alcohol alkoxylate-based compound, and a siloxane-based compound; The laminate has a content of the acrylic resin of 5% by mass or more relative to 100% by mass of the printed layer.

[0008] That is, the present invention relates to the laminate, wherein the adhesive layer has a glass transition temperature of 60°C or lower.

[0009] That is, the present invention relates to the laminate, wherein the adhesive layer is a layer formed using a solventless adhesive.

[0010] That is, the present invention relates to the laminate, wherein the acrylic resin has an acid value of 3 to 250 mgKOH / g.

[0011] That is, the present invention relates to the laminate, wherein the acrylic resin has a glass transition temperature of 0 to 110°C.

[0012] That is, the present invention relates to the laminate, wherein the acrylic resin has a minimum film-forming temperature, and the minimum film-forming temperature is 50°C or lower.

[0013] That is, the present invention relates to the laminate, wherein the printed layer further contains a hydrazine derivative.

[0014] That is, the present invention relates to the laminate, wherein the printed layer further contains an antifoaming agent, and the content of the antifoaming agent is 0.01 to 2% by mass relative to 100% by mass of the printed layer.

[0015] That is, the present invention relates to the laminate, wherein the printed layer further contains an extender pigment, and the extender pigment is at least one selected from the group consisting of barium sulfate, calcium carbonate, kaolin clay, and silica.

[0016] That is, the present invention relates to the laminate, wherein the substrate 1 contains an olefin-based resin.

[0017] That is, the present invention is a method for producing a laminate having a substrate 1, a printing layer, an adhesive layer, and a substrate 2 in this order, a step of printing a printing ink containing an acrylic resin and a compound (A) on the substrate 1 to form the printed layer; and applying an adhesive to the printing layer to form the adhesive layer. The present invention relates to a method for producing a laminate, wherein the compound (A) comprises at least one selected from the group consisting of an acetylene-based compound, an alcohol alkoxylate-based compound, and a siloxane-based compound.

[0018] That is, the present invention relates to a method for producing the laminate, wherein the printing ink further contains an amine compound.

[0019] That is, the present invention relates to the method for producing the laminate, wherein the printing ink further contains an organic solvent having a boiling point of 130°C or higher. [Effects of the Invention]

[0020] It is possible to provide a laminate that is excellent in laminate appearance (no streaky stains or ink loss) and laminate strength, and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0021] <Laminate> The laminate has a substrate 1, a printing layer, an adhesive layer, and a substrate 2 in this order, characterized in that the printing layer contains an acrylic resin and a compound (A), the compound (A) contains at least one compound selected from the group consisting of an acetylene-based compound, an alcohol alkoxylate-based compound, and a siloxane-based compound, and the content of the acrylic resin is 5% by mass or more in 100% by mass of the printing layer. The laminate of the present invention is preferably a packaging material.

[0022] The compatibility of the acrylic resin and compound (A) in the printed layer (1) improves the leveling properties of the printed layer, (2) improves film-forming properties, and (3) improves the adhesion between the substrate 1 and the printed layer, resulting in excellent laminate appearance (no streaky stains or ink loss) and laminate strength. Note that the above-mentioned effects are based on scientific considerations, and the present invention is not limited to those that exhibit only these effects.

[0023] <Print layer> The printed layer of the present invention contains an acrylic resin and a compound (A), and the compound (A) contains at least one compound selected from the group consisting of acetylene-based compounds, alcohol alkoxylate-based compounds, and siloxane-based compounds. The printed layer preferably further contains a hydrazine derivative and / or an antifoaming agent. The printed layer can be formed by printing the printing ink described below using a known printing method and then removing the volatile components.

[0024] <Acrylic resin> Acrylic resin is a synthetic resin whose main component is a derivative of acrylic acid or methacrylic acid. Acrylic resins can be synthesized using solution polymerization and emulsion polymerization. Solution polymerization involves polymerizing acrylic monomers (described below) in a solvent to obtain a resin with a uniform molecular weight distribution. Meanwhile, emulsion polymerization involves emulsifying acrylic monomers (described below) in water and then polymerizing them using a surfactant, making it possible to efficiently produce a high-molecular-weight resin. A styrene-acrylic resin obtained by polymerizing an acrylic monomer (described below) and a styrene monomer (described below) is preferred. The styrene-acrylic resin may have acrylic monomers and styrene monomers bonded alternately, or may have acrylic blocks and styrene blocks.

[0025] The acrylic resin used in the present invention is preferably a water-soluble acrylic resin, more preferably a water-soluble acrylic resin and / or an emulsion-type acrylic resin, and more preferably an emulsion-type acrylic resin from the viewpoint of laminate strength. The water-soluble acrylic resin is an acrylic resin that dissolves in water, while the emulsion-type acrylic resin is a milky white liquid acrylic resin that disperses in water without dissolving.

[0026] The acid value of the acrylic resin is preferably 3 to 250 mgKOH / g, more preferably 60 to 220 mgKOH / g, and even more preferably 120 to 200 mgKOH / g. When the acid value of the acrylic resin is within the above range, the appearance (ink bleed) of the laminate tends to be improved. The glass transition temperature (Tg) of the acrylic resin is preferably 0 to 110°C, more preferably 20 to 100°C, and even more preferably 40 to 80°C. When the glass transition temperature is within the above range, the laminate strength tends to be improved. Furthermore, emulsion-type acrylic resins have a minimum film-forming temperature. When the acrylic resin has a minimum film-forming temperature, the minimum film-forming temperature is preferably 50°C or less, more preferably -30 to 30°C, and even more preferably -10 to 20°C. When the minimum film-forming temperature of the acrylic resin is within the above range, the appearance (ink bleed, streaky stains) and laminate strength of the laminate tend to be improved. In the present invention, when multiple types of acrylic resins are used, the respective values ​​calculated using the following weighted average calculation formulas are used as the acid value, glass transition temperature, weight average molecular weight, and minimum film-forming temperature of the acrylic resin. (Equation 1) Acid value [mgKOH / g] when n types of acrylic resins are included TIFF0007800642000001.tif46157 (Equation 2) Glass transition temperature [°C] when n types of acrylic resins are included TIFF0007800642000002.tif42170 (Equation 3) Weight average molecular weight when n types of acrylic resins are included TIFF0007800642000003.tif38170 (Equation 4) Minimum film-forming temperature when n types of acrylic resins with minimum film-forming temperatures are included TIFF0007800642000004.tif36170

[0027] Acrylic monomers are important for inks because their properties improve the ink's drying speed, gloss, water resistance, and abrasion resistance. Specific compounds include methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Each of these monomers has a different alkyl group, which affects the ink's properties differently. Methyl acrylate is a small molecule and can speed up the ink's curing speed. Ethyl acrylate is a slightly larger molecule and provides flexibility and tackiness to the ink. Butyl acrylate and 2-ethylhexyl acrylate are even larger molecules and can improve the ink's durability and flexibility.

[0028] Styrenic monomers refer to a group of compounds based on styrene. Styrene itself consists of an ethylene group attached to a benzene ring, and various chemical modifications of this structure result in a wide variety of derivatives. Specific examples include alkyl-substituted styrenes such as methylstyrene, ethylstyrene, and propylstyrene, in which the hydrogen atoms on the benzene ring are replaced with methyl, ethyl, and propyl groups, respectively. Halogenated styrenes, such as chlorostyrene and bromostyrene, also exist, in which the hydrogen atoms on the benzene ring are replaced with chloro or bromo groups. Furthermore, sulfonylstyrenes and aminostyrenes, which contain specific sulfur- or nitrogen-containing functional groups, are also known.

[0029] <Basic compound that neutralizes acrylic resin> It is preferable that the ionic groups in the acrylic resin be neutralized with a basic compound. Examples of basic compounds include sodium hydroxide, potassium hydroxide, ammonia, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, ethanolamine, propanolamine, diethanolamine, N-methyldiethanolamine, dimethylamine, diethylamine, triethylamine, N,N-dimethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-propanol, and morpholine. These may be used alone or in combination of two or more. Ammonia is preferred as the basic compound in terms of water resistance of printed matter, residual odor, etc.

[0030] Commercially available acrylic resins include BASF's Joncryl 52J, 60J, 63J, 70J, HPD-96J, HPD-196, PDX-7357, PDX-7616A, PDX-7732, and PDX-7164. , Neocryl A-1092, A-1094, A-2092, A-1127, A-1125 manufactured by COVESTRO, and Hi-Loss-X YL-1098, GL-2439, X-2010L manufactured by Seiko PMC Corporation.

[0031] The content of the acrylic resin is 5% by mass or more, preferably 10 to 60% by mass, and more preferably 20 to 50% by mass, based on 100% by mass of the printed layer. When the content of the acrylic resin is within the above range, the leveling property of the printed layer is excellent, and the laminate appearance (streaky stains, ink loss) tends to be improved.

[0032] <Resins other than acrylic resins> The printing layer used in the present invention may contain a resin other than the above-mentioned acrylic resin, such as a urethane resin, a styrene-maleic anhydride resin, a polyester resin, a rosin-modified maleic acid resin, a cellulose-based resin, or a chlorinated polyolefin. The aqueous resin may be used alone or in combination of two or more. The mass ratio of the acrylic resin to the resin other than the acrylic resin is preferably 50:50 to 100:0, and more preferably 80:20 to 100:0. When the mass ratio of the acrylic resin to the resin other than the acrylic resin is within the above range, the printing layer has excellent leveling properties, which tends to improve the laminate appearance (reduction of streaky stains), laminate appearance (reduction of ink loss), and laminate strength.

[0033] <Compound (A)> The compound (A) used in the present invention contains at least one selected from the group consisting of acetylene-based compounds, alcohol alkoxylate-based compounds, and siloxane-based compounds, and is preferably an acetylene-based compound. The compound (A) is also preferably a surfactant. The HLB value of the compound (A) is preferably 3 to 14, more preferably 3 to 9. When the HLB value of the compound (A) is within the above range, the appearance (ink bleed) of the laminate tends to be improved. The content of the compound (A) is preferably 0.1 to 10 mass%, more preferably 0.2 to 7 mass%, even more preferably 0.3 to 4 mass%, and particularly preferably 0.5 to 2 mass%, based on 100 mass% of the printed layer. When the content of the compound (A) is within the above range, the appearance (streaky stains, ink bleed) and laminate strength of the laminate tend to be improved.

[0034] <Acetylene-based compounds> The acetylene compound used in the present invention refers to a compound having an acetylene group, and specific compound names include 2-butyne-1,4-diol, 3-methyl-1-butyne-3-ol, and 4-pentyne-1,3-diol. Among these, it is preferable to use an acetylene glycol compound having an acetylene group at the center and a symmetrical structure. The HLB value of the acetylene compound is preferably 3 to 14, and more preferably 3 to 9. When the HLB value of the acetylene compound is within the above range, the appearance (ink release) of the laminate tends to be improved.

[0035] Commercially available acetylene compounds that can be used include Olfine E1010, Olfine E1020, Surfynol 104, Surfynol 420, Surfynol 440, Surfynol 465, and Surfynol 485 manufactured by Nissin Chemical Industry Co., Ltd.

[0036] <Alcohol alkoxylate compounds> The alcohol alkoxylate compound used in the present invention is a compound formed by bonding an alkoxy group to an alcohol.

[0037] Commercially available alcohol alkoxylate compounds include BYK-DYNWET800 manufactured by BYK Japan.

[0038] <Siloxane compounds> The siloxane compounds used in this invention have a basic structure consisting of alternating bonds between silicon and oxygen atoms, and are used in a variety of industrial fields due to their unique physical and chemical properties. Specifically, they have the effect of reducing surface tension at interfaces, thereby providing effects for controlling emulsification, dispersion, foaming, cleaning, and smoothness. There are many types of siloxane compounds, and particularly representative examples include polydimethylsiloxane, amino-modified silicone oil, and methylpolysiloxane.

[0039] Commercially available siloxane compounds that can be used include TEGO WET 260 and TEGO TWIN 4000 manufactured by EVONIK, and BYK-302 and 333 manufactured by BYK Japan.

[0040] <Coloring agent> The print layer may further contain a colorant. As the colorant, pigments such as inorganic colorants and organic colorants can be suitably used. Examples of inorganic colorants include titanium oxide, zinc oxide, zinc sulfide, aluminum hydroxide, chromium oxide, carbon black, and mica. From the viewpoints of coloring power, hiding power, chemical resistance, and weather resistance, titanium oxide is preferred as a white colorant, and titanium oxide having a basic pigment surface is more preferred. Examples of organic colorants include organic pigments and dyes commonly used in inks, paints, and recording materials. Examples of such organic colorants include azo-based, phthalocyanine-based, anthraquinone-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethine azo-based, dicetpyrrolopyrrole-based, and isoindoline-based pigments. Any compound listed in the Color Index can be used as the colorant. It is preferable to use copper phthalocyanine for indigo ink and CI Pigment Yellow 83 for yellow ink in terms of lightfastness. The content of the colorant is preferably 20 to 80% by mass, and more preferably 30 to 70% by mass, relative to 100% by mass of the printed layer.

[0041] <Extender pigment> From the viewpoints of laminate strength and laminate appearance (streaky stains, ink loss), the printed layer preferably further contains an extender pigment. Examples of extender pigments include barium sulfate, calcium carbonate, magnesium carbonate, kaolin clay, mica, and silica, and these may be used alone or in combination of two or more. From the viewpoint of laminate appearance (streaky stains), at least one pigment selected from the group consisting of barium sulfate, calcium carbonate, kaolin clay, and silica is preferred, and at least one pigment selected from the group consisting of barium sulfate, calcium carbonate, and kaolin clay is more preferred. From the viewpoint of laminate strength, the content of the extender pigment is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 8% by mass or less, based on 100% by mass of the solids content of the printed layer.

[0042] <Additives> The printing layer may contain additives as needed. Examples of such additives include known additives used in printing inks, such as crosslinking agents (curing agents), antifoaming agents, waxes, plasticizers, and preservatives. Preferably, the printing layer contains a crosslinking agent and / or an antifoaming agent. Examples of crosslinking agents include hydrazine derivatives, silane coupling agents, and carbodiimides, with hydrazine derivatives being particularly preferred.

[0043] <Hydrazine derivatives> A hydrazine derivative generally refers to a compound in which the amide bond of a carboxylic acid is replaced with hydrazine (NH-NH). Specific names of hydrazine derivatives include adipic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, and terephthalic acid dihydrazide, with adipic acid dihydrazide being preferred. The content of the hydrazine derivative is preferably 0.1 to 2.0 mass %, and more preferably 0.2 to 0.8 mass %, relative to 100 mass % of the printed layer. When the content of the hydrazine derivative is within the above range, the laminate strength tends to be improved.

[0044] <Antifoaming agent> The defoaming agent used in the present invention acts on the interface to reduce surface tension, thereby destroying bubbles. This tends to improve the smoothness of the printed layer surface and improve the laminate strength and laminate appearance (reduction of streaky stains and ink loss). Specific examples include siloxane-based defoaming agents, alcohol-based defoaming agents, mineral oil-based defoaming agents, aliphatic derivative-based defoaming agents, and hydrocarbon-based defoaming agents. Among these, it is preferable to use at least one defoaming agent selected from the group consisting of siloxane-based defoaming agents, hydrocarbon-based defoaming agents, and aliphatic derivative-based defoaming agents, with a siloxane-based defoaming agent being more preferred. The content of the defoaming agent is preferably 0.01 to 3 mass% of the printed layer (100 mass%), more preferably 0.02 to 2 mass%, and even more preferably 0.03 to 1 mass%. When the content of the defoaming agent is 0.01 mass% or more, bubbles in the ink solution during printing are suppressed, which tends to improve the appearance of the print. When the content of the defoaming agent is 3 mass% or less, adhesive repellency during lamination is suppressed, which tends to improve the appearance of the laminate (streaky stains, ink loss) and the laminate strength.

[0045] <Siloxane-based defoaming agent> Siloxane-based defoamers are preferably those whose main component is silicone oil, whose basic structure is alternating bonds between silicon and oxygen atoms. Silicone oil has high surface activity, which can reduce the surface tension of liquids and prevent the formation of bubbles. Specific examples include polydimethylsiloxane (PDMS), amino-modified silicone oil, and epoxy-modified silicone oil. Each of these compounds has different properties, and they are selected depending on the usage environment and purpose.

[0046] Commercially available products that can be used as siloxane-based defoaming agents include TEGO FOAMEX 1488, 3062, 852, 810, 840, and 835 manufactured by EVONIK, and BYK-017, 1707, 024, and 094 manufactured by BYK Japan.

[0047] <Hydrocarbon-based defoaming agent> Hydrocarbon defoamers are compounds typically used to suppress or eliminate foam in oily systems. These defoamers are primarily based on hydrocarbons and exert their defoaming effect by reducing foam stability through surfactant activity. Specific compounds include polyalkylene glycols, alkyl benzenes, and mineral oils.

[0048] Commercially available products that can be used as hydrocarbon-based defoaming agents include TEGO FOAMEX K3 and K7 manufactured by EVONIK, and BYK-038, 039, and 1690SD manufactured by BYK Japan.

[0049] <Aliphatic derivative antifoaming agents> Aliphatic derivative defoamers contain specific aliphatic derivatives as their main components, which allows them to exhibit excellent defoaming effects. Specifically, these defoamers generally contain aliphatic derivatives such as fatty acid amides, fatty acid esters, and fatty acid ethers. These compounds have surface-active properties and reduce the surface tension of bubbles, thereby promoting bubble bursting and exerting a defoaming effect.

[0050] An example of a commercially available product that can be used as an aliphatic derivative defoaming agent is BYK-014 manufactured by BYK Japan.

[0051] The mass ratio of the total acrylic resin to the total antifoaming agent is preferably 99.9:0.1 to 90:10, and more preferably 99.8 to 95:5, which tends to improve the laminate appearance (ink loss) and laminate strength.

[0052] <Printing ink> The printing ink used in the present invention is preferably a water-based printing ink. The printing ink contains the above-mentioned acrylic resin, compound (A), and medium, and may further contain various materials and amine compounds described above in the <printing layer> section.

[0053] <medium> The printing ink used in the present invention contains water as a medium, and preferably further contains an organic solvent having a boiling point of 130° C. or higher, more preferably an organic solvent having a boiling point of 130 to 280° C. Examples of organic solvents having a boiling point of 130° C. or higher include ethylene glycol (boiling point 197° C.), propylene glycol (boiling point 188° C.), butylene glycol (boiling point 230° C.), hexylene glycol (boiling point 250° C.), dipropylene glycol (boiling point 230° C.), diethylene glycol (boiling point 244° C.), tripropylene glycol (boiling point 271° C.), triethylene glycol (boiling point 285° C.), propylene glycol monoethyl ether (boiling point 133° C.), and propylene glycol monopropyl ether. Examples of suitable ethylene glycol monomethyl ethers include propylene glycol monomethyl ether (boiling point 150°C), propylene glycol monobutyl ether (boiling point 170°C), dipropylene glycol monomethyl ether (boiling point 190°C), dipropylene glycol monoethyl ether (boiling point 132°C), tripropylene glycol monomethyl ether (boiling point 243°C), diethylene glycol monomethyl ether (boiling point 193°C), diethylene glycol monoethyl ether (boiling point 196°C), and diethylene glycol monobutyl ether (boiling point 231°C). In addition, organic solvents having a boiling point of less than 130°C may include, for example, methanol (boiling point 64°C), ethanol (boiling point 78°C), 1-propanol (boiling point 97°C), 2-propanol (boiling point 82°C), 1-butanol (boiling point 117°C), 2-butanol (boiling point 99°C), and isobutanol (boiling point 108°C). The total content of the media contained in the printing ink used in the present invention is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, based on 100% by mass of the printing ink. The water content is preferably 30 to 70% by mass, and more preferably 35 to 65% by mass, based on 100% by mass of the printing ink. The content of organic solvents with a boiling point of 130°C or higher is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of the printing ink. The preferred content of the organic solvent includes 0% by mass, but is preferably 0.2% by mass or more, more preferably 0.5% by mass or more.

[0054] <Amine compounds> From the viewpoint of laminate appearance (streaky stain prevention), the printing ink preferably contains an amine compound. The above-mentioned embodiment of <Basic compound for neutralizing acrylic resin> can be used as the amine compound. The boiling point of the amine compound is preferably -40 to 180°C, more preferably -40 to 100°C. When the boiling point of the amine compound is within the above range, the laminate appearance (streaky stain prevention) and laminate strength tend to be improved.

[0055] The method for producing the printing ink is not particularly limited, and the ink can be produced by dispersing and mixing the above-mentioned raw materials using a known dispersing machine such as a roller mill, ball mill, pebble mill, attritor, or sand mill. If the printing ink contains air bubbles or unexpectedly large particles, these particles are preferably removed by filtration or the like, as they will deteriorate the quality of the printed matter. Any conventionally known filter can be used.

[0056] <Formation of printing layer> The printed layer can be formed by printing the printing ink onto a substrate, which will be described later. Suitable printing methods include known flexographic printing and gravure printing. The printing layer is obtained by applying the ink using the printing method and then drying and fixing it using an oven or the like. The drying temperature is usually about 40 to 100°C. The thickness of the printed layer is preferably 0.1 to 5 μm, more preferably 0.1 to 2.5 μm. The printing speed is preferably 100 to 300 m / min, more preferably 150 to 280 m / min, and even more preferably 200 to 250 m / min.

[0057] <Flexographic printing method> Flexographic printing is more preferably used as the printing method. Examples of anilox rolls that can be used in flexographic printing include ceramic anilox rolls with cell engravings and chrome-plated anilox rolls. To obtain a printed product with excellent dot reproducibility, anilox rolls with a line ruling of at least five times, preferably at least six times, the line ruling used in printing are preferred. For example, when the line ruling used is 75 lpi, anilox rolls with a line ruling of at least 375 lpi are preferred. The anilox roll capacity is preferably 1 to 10 cc / m2, from the viewpoint of the drying property and blocking property of the printing ink. 2 , more preferably 2 to 8 cc / m 2 is.

[0058] Plates used for flexographic printing include photosensitive resin plates that use ultraviolet curing with a UV light source, and elastomer material plates that use direct laser engraving. Regardless of the method used to form the image area of ​​the flexographic plate, a plate with a screening line count of 75 lpi or more is preferred. Any sleeve or cushion tape can be used to attach the plate.

[0059] Flexographic printing machines include CI type multicolor flexographic printing machines and unit type multicolor flexographic printing machines, and ink supply methods include chamber methods and two-roll methods, and any appropriate printing machine can be used.

[0060] <Adhesive layer> The adhesive layer in the present invention is not particularly limited as long as it can bond the respective layers. However, it is preferably at least one selected from the group consisting of olefin-based resins such as polypropylene resins and polyethylene resins, acrylic resins, ethylene-vinyl acetate copolymer-based resins, cured products of polyols and isocyanate-based curing agents, imine-based resins, isocyanate-based resins, polybutadiene-based resins, and titanium-based resins. It is more preferably a cured product of polyols and isocyanate-based curing agents. The adhesive layer may be a single layer or multiple layers. When multiple layers are used, it is preferred that the adhesive layer (first layer) contains an imine-based resin and / or an isocyanate-based resin, and the adhesive layer (second layer) contains an olefin-based resin. The adhesive layer can be formed using the above resins. The method for forming the adhesive layer is not particularly limited. Known processing methods such as solventless lamination, dry lamination, and extrusion lamination can be used. Solventless lamination is preferred. The solventless lamination method is a method of forming an adhesive layer using a solventless adhesive whose raw material is at least one selected from the group consisting of the above-mentioned resins. The glass transition temperature of the adhesive layer is preferably 60°C or lower, more preferably -10 to 60°C, and even more preferably 0 to 40°C. When the glass transition temperature of the adhesive is within the above range, the leveling properties of the adhesive layer are improved. Furthermore, the adhesive layer moderately relieves stress, which tends to improve the laminate appearance (streaky stains, ink loss) and laminate strength. The glass transition temperature is measured after curing the adhesive layer. When the adhesive layer is formed from multiple layers with different glass transition temperatures, the glass transition temperature is calculated as a weighted average of the glass transition temperatures of the individual layers.

[0061] The resin contained in the adhesive layer used in the present invention can be synthesized by the method described in JP-A-2006-306931 or the like. The method for controlling the glass transition temperature of the adhesive layer is not particularly limited. For example, the glass transition temperature of a resin synthesized by the above method or a commercially available resin such as EA-N373A / B, EA-N373A / EA-N6173, EA-N6001 / EA-N5510, EA-N6802 / EA-N5802, EA-N6008 / EA-N5618, TM-320 / CAT-13B, TM-340V / CAT-29B, TM-2314 / CAT-RT37, TM-569 / CAT-RT37, or TM-250HV / CAT-RT86L-60 manufactured by Toyo-Morton Co., Ltd. may be measured by the following method, and the corresponding resin may be used.

[0062] <Glass transition temperature of adhesive layer> Each adhesive solution was applied to a release-treated release sheet and dried, and then the solution was cured (aged) by keeping it at 40°C for 24 hours or 40°C for 96 hours to form an adhesive layer approximately 50 μm thick. The adhesive layer was cut into a size of 1.5 cm x 0.5 cm, peeled from the release sheet, and the glass transition temperature of the cut piece was measured using a dynamic viscoelasticity tester (IT Measurement Control Co., Ltd., DVA-200). The temperature range for the measurement was -150 to 250°C, and the heating rate was 10°C / min. The glass transition temperature was calculated from the peak-top temperature of the obtained tan δ waveform.

[0063] Preferred combinations of components in the printed layer and the adhesive layer include those in which the printed layer contains an acrylic resin and compound (A) and the adhesive layer contains at least one selected from the group consisting of olefin-based resins, acrylic resins, ethylene-vinyl acetate copolymer resins, and cured products of polyols and isocyanate-based curing agents, as well as those in which the printed layer contains an acrylic resin and compound (A) and the adhesive layer has a glass transition temperature of 60°C or lower. These combinations tend to (1) improve adhesion between the printed layer and the adhesive layer, (2) improve leveling of the adhesive layer, and (3) suppress dissolution of the printed layer, thereby further improving the laminate appearance (reducing streaks and ink loss) and laminate strength. The above effects are based on scientific considerations, and the present invention is not limited to those that exhibit these effects.

[0064] <Polyol> The polyol used in the adhesive layer may be any compound having two or more hydroxyl groups and may be selected from known polyols. Examples of polyols include polyester polyols, polycarbonate polyols, polycaprolactone polyols, polyether polyols, and polyolefin polyols. These polyols may be used alone or in combination of two or more. From the viewpoint of laminate appearance and laminate strength, the polyol preferably includes a polyether polyol and / or a polyester polyol.

[0065] <Polyether polyol> The polyether polyol may be any compound having two or more hydroxyl groups and two or more ether bonds in the molecule, and may be either a bifunctional polyether polyol or a trifunctional or higher functional polyether polyol. Alternatively, the polyether polyol may be one in which a urethane bond is introduced by reacting an isocyanate compound with a hydroxyl group. These polyether polyols may be used alone or in combination of two or more.

[0066] Examples of bifunctional polyether polyols include polyalkylene glycols such as polyethylene glycol, polytrimethylene glycol, polypropylene glycol, polytetramethylene glycol, and polybutylene glycol; polyethylene glycol / polypropylene glycol block copolymers; and propylene oxide-ethylene oxide random polyethers. Polyether polyols may also be prepared by addition polymerization of low-molecular-weight polyol initiators such as water, ethylene glycol, and propylene glycol with oxirane compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran. Examples of such addition polymers include propylene glycol-propylene oxide adducts.

[0067] Examples of tri- or higher functional polyether polyols include modified polyether polyols obtained by ring-opening polymerization of various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether, using a low-molecular-weight polyol such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, pentaerythritol, sorbitol, or sucrose as an initiator; and lactone-based polyester polyols obtained by polycondensation reaction of the above-mentioned aliphatic polyols with various lactones such as ε-caprolactone.

[0068] <Polyester polyol> Examples of polyester polyols include polyester polyols obtained by reacting a carboxyl group component with a hydroxyl group component, and polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone). Polyols may also be those in which a urethane bond has been introduced by reacting a portion of the hydroxyl groups with an isocyanate compound, or those in which a carboxyl group has been introduced by reacting a portion of the hydroxyl groups with an acid anhydride. The carboxyl group component of the polyester polyol obtained by reacting a carboxyl group component with a hydroxyl group component is preferably a polycarboxylic acid having carboxyl groups at both ends, such as acyclic aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, and fumaric acid; alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, and 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid; anhydrides or ester-forming derivatives of these aliphatic or aromatic dicarboxylic acids; and polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids, and dimer acids.

[0069] The hydroxyl group component is not particularly limited as long as it is a known component, but examples thereof include diols and tri- or higher functional polyols, and diols are preferred because diols inhibit excessive crosslinking when mixed with polyisocyanate and improve pot life. Examples of the diol include aliphatic diols such as ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3,3'-dimethylolheptane, and 1,4-bis(hydroxymethyl)cyclohexane; ether glycols such as polytetramethylene ether glycol and polyoxyethylene glycol; modified polyether diols obtained by ring-opening polymerization of the aliphatic diols with various cyclic ether bond-containing compounds such as ethylene oxide and tetrahydrofuran; lactone-based polyester polyols obtained by polycondensation reaction of the aliphatic diols with various lactones such as lactanoids and ε-caprolactone; and alkylene oxide adducts of bisphenols obtained by adding ethylene oxide or the like to bisphenols such as bisphenol A and bisphenol F. The diol is preferably an aliphatic diol, and more preferably at least one selected from the group consisting of ethylene glycol, diethylene glycol, neopentyl glycol, and 1,6-hexanediol.

[0070] Examples of the tri- or higher functional polyols include aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, and pentaerythritol; modified polyether polyols obtained by ring-opening polymerization of the aliphatic polyols with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether; and lactone-based polyester polyols obtained by polycondensation of the aliphatic polyols with various lactones such as ε-caprolactone. The tri- or higher functional polyol is preferably an aliphatic polyol, more preferably trimethylolpropane.

[0071] The polyol may be one in which urethane bonds are introduced into some of the hydroxyl groups by reacting an isocyanate compound with the polyol. Examples of the isocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate, and hydrogenated diphenylmethane diisocyanate.

[0072] The polyol may also be one in which a carboxyl group has been introduced by reacting an acid anhydride with a portion of the hydroxyl groups (hereinafter, this may be abbreviated as acid-modified). Examples of the acid anhydride include pyromellitic anhydride, mellitic anhydride, trimellitic anhydride, and trimellitic ester anhydride. Examples of trimellitic ester anhydride include ester compounds obtained by esterifying alkylene glycol or alkanetriol having 2 to 30 carbon atoms with trimellitic anhydride, and specific examples of the trimellitic ester anhydride include ethylene glycol bis-anhydrotrimellitate and propylene glycol bis-anhydrotrimellitate.

[0073] The weight-average molecular weight (Mw) of the polyol is preferably 500 to 80,000, and more preferably 1,000 to 50,000. When used as a solventless adhesive, from the viewpoint of improving adhesive strength, heat seal strength, and handleability, it is preferably 500 to 10,000, and more preferably 1,000 to 8,000. A weight-average molecular weight of 500 or more is preferable because the cohesive force of the polyurethane polyol is improved, and the adhesive strength and heat seal strength are improved. A weight-average molecular weight of 10,000 or less is preferable because the viscosity is reduced, and the appearance performance and handleability are improved.

[0074] The acid value of the polyol is not particularly limited, but is preferably 0 to 50 mgKOH / g, more preferably 0 to 40 mgKOH / g.The hydroxyl value of the polyol is not particularly limited, but is preferably 1 to 200 mgKOH / g, more preferably 10 to 150 mgKOH / g, even more preferably 20 to 120 mgKOH / g, and more preferably 50 to 120 mgKOH / g.

[0075] <Isocyanate-based curing agent> Isocyanate-based curing agents function as curing agents in reactive adhesives, and by having isocyanate groups that are reactive with hydroxyl groups, the adhesive strength and cohesive force of the adhesive are increased, and curing is possible at low temperatures around room temperature.

[0076] The isocyanate curing agent is preferably a diisocyanate or a urethane prepolymer which is a reaction product of a diisocyanate and a polyol, and various known aromatic, aliphatic, or alicyclic diisocyanates can be used as the diisocyanate. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylsilyl diisocyanate, methyl ... Representative examples include methylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimer diisocyanate in which the carboxyl groups of dimer acid are converted to isocyanate groups. Polyisocyanate compounds with three or more functional groups, such as adducts of trimethylolpropane, isocyanurates, and biuret compounds, can also be used. These can be used alone or in combination.

[0077] In an embodiment, the polyol and isocyanate curing agent are preferably used so that the molar equivalent ratio NCO / OH of the functional groups of the hydroxyl groups derived from the polyol and the isocyanate groups derived from the isocyanate resin is 1.5 to 8.0, and more preferably 2.0 to 5.0. An NCO / OH molar equivalent ratio of 2.0 or more is preferred because the viscosity of the derived polyisocyanate is reduced, improving appearance performance and pot life. An NCO / OH molar equivalent ratio of 5.0 or less is preferred because the cohesive strength of the derived polyisocyanate is improved, reducing residual tack.

[0078] <Adhesive> The adhesive used in the present invention can contain the materials described above in the <adhesive layer> section, and may also contain reaction catalysts, silane coupling agents, phosphoric acid or phosphoric acid derivatives, leveling agents, antifoaming agents, and the following additives, provided that the effects of the present invention are not impaired. Examples of additives include inorganic fillers such as silica, alumina, mica, talc, aluminum flakes, and glass flakes; layered inorganic compounds; stabilizers (antioxidants, heat stabilizers, UV absorbers, hydrolysis inhibitors, etc.); rust inhibitors, thickeners, plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, fillers, nucleating agents, and catalysts for adjusting the curing reaction. Furthermore, the adhesive may contain a medium, as described below, contained in the adhesive.

[0079] <Medium contained in adhesive> The medium contained in the adhesive can be the same as that described in the <printed layer> above. When the adhesive is oil-based, it is preferable to use an organic solvent.

[0080] <Formation of adhesive layer> The adhesive layer is formed by curing, for example, at 20 to 60°C for about one day to one week after a known lamination process such as a solventless lamination process. The lamination process is not limited, but examples include solventless lamination, dry lamination, and extrusion lamination, with solventless lamination being preferred. The thickness of the adhesive layer is not particularly limited and can be selected appropriately depending on the application. It is preferably in the range of 1.0 to 3.0 μm for solventless lamination, 1.0 to 5.0 μm for dry lamination, and 10 to 50 μm for extrusion lamination. Having the adhesive layer thickness within the above range improves physical properties such as lamination strength and heat seal strength, as well as the appearance of the laminate.

[0081] <Base material> The substrate 1 and the substrate 2 are not particularly limited and may be, for example, a conventionally known plastic film, paper, metal foil, etc., and are preferably a plastic film. The substrate 1 and the substrate 2 may be the same or different. The plastic film may be a film of a thermoplastic resin or a thermosetting resin, preferably a film of a thermoplastic resin, such as polyolefin, polyester, polyamide, polystyrene, vinyl chloride resin, vinyl acetate resin, ABS resin, acrylic resin, acetal resin, polycarbonate resin, or cellulose-based plastic. The substrate 1 and the substrate 2 may each have a barrier layer formed of a vapor-deposited film of one or more inorganic substances or inorganic oxides, such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), and yttrium (Y). The vapor-deposited film may be formed of two or more layers, and may be formed of the same material or different materials. Among the above, from the viewpoints of adhesion and gas barrier properties, the barrier layer is preferably formed of aluminum, aluminum oxide (alumina), or silicon oxide (silica).

[0082] The substrate 1 is preferably a plastic film. Examples of plastic films include those commonly used in packaging materials, such as polyester resin films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polylactic acid (PLA); polyolefin resin films such as polyethylene (PE) and polypropylene (PP); polystyrene resin films; polyamide resin films such as nylon 6 and poly-p-xylylene adipamide (MXD6 nylon); polycarbonate resin films; polyacrylonitrile resin films; polyimide resin films; and composites or mixtures thereof (e.g., nylon 6 / MXD6 / nylon 6, nylon 6 / ethylene-vinyl alcohol copolymer (EVOH) / nylon 6). Among these, polyolefin resin films such as polyethylene (PE) and polypropylene (PP) are preferred from the viewpoint of laminate strength.

[0083] When the substrate 2 is the outermost layer of the laminate, the substrate 2 is preferably a sealant substrate among plastic films. Examples of sealant base materials include polyethylenes such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE), acid-modified polyethylene, polypropylene (PP), acid-modified polypropylene, copolymerized polypropylene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid ester copolymer, ethylene-(meth)acrylic acid copolymer, and ionomer. Furthermore, by providing the sealant substrate with unevenness having a height difference of about several μm, it is possible to impart slipperiness and tearability to the packaging bag.

[0084] The thickness of the substrate 1 can be selected arbitrarily, but from the viewpoints of formability and transparency, it is preferably 5 μm to 50 μm, more preferably 10 μm to 40 μm. When the film thickness of the substrate 1 is 5 μm or more, the rigidity of the laminate increases, improving the strength of the laminate. For example, this is preferable because it can suppress the occurrence of delamination and wrinkling, which are likely to occur when the laminate of the present invention and the packaging bag of the present invention are subjected to impact. When the thickness of the substrate 1 is 50 μm or less, this is preferable because it can increase the flexibility of the laminate, making it easier to process, for example, when filling the packaging bag with contents.

[0085] The thickness of the substrate 2 can be selected arbitrarily, but from the viewpoint of strength as a packaging material, it is preferably 5 μm to 500 μm, more preferably 10 μm to 250 μm, and even more preferably 15 μm to 200 μm. A thickness of 5 μm or more for the substrate 2 is preferable because it increases the heat seal strength, allowing the packaging bag of the present invention to be filled with heavier contents, expanding the application of the packaging bag. Furthermore, a thickness of 500 μm or less for the substrate 2 is preferable because it leads to cost reduction and increases the flexibility of the laminate, improving, for example, the processability of filling the contents as described above.

[0086] The laminate of the present invention can be produced, for example, by printing a printing ink on a substrate 1, drying the ink, applying an adhesive, overlaying the substrate 2, and then curing the adhesive through an aging process. A plurality of printed layers and substrates 2 may be provided. For example, the printed layers may be configured as color printed layer / white printed layer, color printed layer / white printed layer / white printed layer, or color printed layer / color printed layer / white printed layer / white printed layer.

[0087] Examples of the structure of the laminate of the present invention are given below, but are not limited to these. When the laminate has multiple adhesive layers, at least one of the adhesive layers should be an adhesive layer formed from the solventless adhesive of the present invention. In the following, transparent vapor deposition refers to a vapor-deposited layer of silica or alumina. Biaxially oriented polypropylene (OPP) / printing layer / adhesive layer / non-oriented polypropylene (CPP), OPP / printing layer / adhesive layer / AL vapor deposition CPP, OPP / printing layer / adhesive layer / AL vapor deposition CPP, OPP / printed layer / adhesive layer / AL vapor-deposited polyethylene terephthalate (AL vapor-deposited PET) OPP / printed layer / adhesive layer / linear low-density polyethylene (LLDPE), OPP / printing layer / adhesive layer / EVOH / LLDPE PET / printing layer / adhesive layer / CPP, PET / printing layer / adhesive layer / AL vapor deposition CPP, PET / printed layer / adhesive layer / AL vapor-deposited PET, PET / printing layer / adhesive layer / LLDPE, PET / printing layer / adhesive layer / EVOH / LLDPE PET / printed layer / adhesive layer / nylon (NY) / CPP, PET / printing layer / adhesive layer / AL / CPP, PET / printing layer / adhesive layer / NY / AL / CPP, MDOPE / printing layer / adhesive layer / LLDPE, NY / printing layer / adhesive layer / CPP, NY / printing layer / adhesive layer / AL vapor deposition CPP, NY / printed layer / adhesive layer / AL vapor-deposited PET, NY / printing layer / adhesive layer / LLDPE,

[0088] <Manufacturing of laminate> The laminate of the present invention comprises a substrate 1, a printing layer, an adhesive layer, and a substrate 2 in this order, and is preferably produced by a production method including the following steps (1) and (2). Step (1): A basic step of forming the printing layer on a substrate 1 by flexographic printing with a printing ink containing an acrylic resin and at least one compound selected from the group consisting of an acetylene-based compound, an alcohol alkoxylate-based compound, and a siloxane-based compound. Step (2): A step of applying an adhesive containing a polyol and an isocyanate-based curing agent onto the printed layer to form the adhesive layer. [Example]

[0089] The present invention will be specifically described below with reference to examples and comparative examples. "Parts" and "%" mean "parts by mass" and "% by mass" unless otherwise specified. Examples 3, 4, 7 to 11, and 32 to 35 are reference examples.

[0090] [Method for measuring number average molecular weight (Mn) and weight average molecular weight (Mw)] The number-average molecular weight and weight-average molecular weight were measured using a GPC (gel permeation chromatography) "Shodex GPC System-21" manufactured by Showa Denko Co., Ltd. GPC is a liquid chromatography that separates and quantifies substances dissolved in a solvent based on differences in their molecular size. The solvent was tetrahydrofuran, and the molecular weight was determined in polystyrene equivalent.

[0091] [Method for measuring acid value (AV)] The acid value is the number of milligrams of potassium hydroxide required to neutralize the acidic components contained in 1 g of resin, and was calculated by potentiometric titration with a potassium hydroxide-ethanol solution in accordance with JIS K2501.

[0092] <Water-based ink production> (Preparation of Water-Based Ink (C-1)) Copper phthalocyanine (LIONOL BLUE FG7400-G manufactured by Toyo Color Co., Ltd.) 18.0 parts, calcium carbonate 2.0 parts, water-soluble acrylic resin AC1 (acid value 210 mg KOH / g, Tg 70 ° C, molecular weight 12000, solid content 30%) 48.0 parts, water 10.0 parts, 1-propanol 1.0 parts, stirred and mixed and milled with a sand mill, then water-based acrylic emulsion resin (AE1) 5.0 parts, water 8.25 parts, propylene glycol 3.0 parts, acetylene compound (acetylene glycol compound, HLB value: 4, solid content: 100%) 0.5 parts, polyethylene wax (particle size: 3 μm, penetration: <1, solid content: 40%, solvent: water) 2.0 parts, siloxane-based antifoaming agent (solid content: 100%) 0.05 parts of the above-mentioned acrylic acid, 0.2 parts of adipic acid dihydrazide (solid content 100%), and 2 parts of N,N-dimethylaminoethanol were mixed with stirring to prepare a water-based ink (C-1).

[0093] (Preparation of water-based inks (C-2 to C-30, CC-1 to CC-3)) Water-based inks C-2 to C-30 and CC-1 to CC-3 were prepared in the same manner as in C-1 above, except that the raw materials and ratios shown in Tables 1-1 to 1-3 were used. The raw materials used are as follows: Water-soluble acrylic resin AC2 (acid value 270 mg KOH / g, Tg 130°C, molecular weight 6000, solid content 30%) Acrylic emulsion resin AE1 (acid value 20 mg KOH / g, Tg 5°C, minimum film forming temperature 5°C, solid content 45%) Acrylic emulsion resin AE2 (acid value 60 mg KOH / g, Tg -5°C, minimum film forming temperature 0°C, solid content 45%) Acrylic emulsion resin AE3 (acid value 60 mg KOH / g, Tg 75°C, minimum film forming temperature 55°C, solid content 45%) Water-soluble urethane resin (acid value 35 mg KOH / g, Tg -10°C, solid content 30%) Alcohol alkoxylate compounds (solids 100%) Siloxane compounds (solid content 100%) Fluorine-based compounds (100% solids) Hydrocarbon-based defoamer (solids 100%) Aliphatic derivative defoamer (solid content 100%)

[0094] (Preparation of water-based ink (W-1)) 38.0 parts of titanium dioxide (Teika Titanix JR-805), 2.0 parts of calcium carbonate, 33.0 parts of aqueous acrylic resin AC1, 3.25 parts of water, and 1.0 part of 1-propanol were mixed and stirred, and then ground in a sand mill. Then, 15.0 parts of aqueous acrylic emulsion resin (AE1), 3.25 parts of water, 3.0 parts of propylene glycol, 0.5 parts of an acetylene glycol compound (acetylene glycol compound, HLB value: 4, solids content: 100%), 2.0 parts of polyethylene wax (particle size: 3 μm, penetration: <1, solids content: 40%, solvent: water), 0.05 parts of a silicone antifoaming agent (solids content: 100%), 0.2 parts of adipic acid dihydrazide, and 2 parts of N,N-dimethylaminoethanol were mixed and stirred to prepare aqueous ink (W-1).

[0095] [Table 1-1]

[0096] [Table 1-2]

[0097] [Table 1-3]

[0098] (Preparation of adhesives (AD-1 to AD-3)) The following raw materials were mixed and stirred to obtain adhesives AD-1 to AD-3. (AD-1) Polyol A-1 (polyether compound, solids 100%) Isocyanate-based hardener B-1 (aliphatic compound, solid content 100%) Polyol A-1 and isocyanate-based curing agent B-1 were mixed in a mass ratio of 100:50. (AD-2) Polyol A-2 (a combination of polyether and polyester compounds, solid content 100%) Isocyanate-based hardener B-2 (aromatic compound, solid content 100%) Polyol A-2 and isocyanate-based curing agent B-2 were mixed in a mass ratio of 80:100. (AD-3) Polyol A-3 (polyether compound, solids content 70%) Isocyanate-based hardener B-3 (aromatic compound, solid content 60%) Polyol A-3 and isocyanate-based curing agent B-3 were mixed in a mass ratio of 100:50.

[0099] <Adhesive evaluation> <Glass transition temperature of adhesive layer> Each adhesive solution was applied to a release-treated release sheet and dried, and then the solution was cured (aged) by keeping it at 40°C for 24 hours or 40°C for 96 hours to form an adhesive layer approximately 50 μm thick. The adhesive layer was peeled off from the release sheet, and the glass transition temperature was measured using a dynamic viscoelasticity tester. The temperature rise rate during the measurement was 10°C / min. The glass transition temperature was calculated from the peak-top temperature of the tan δ waveform obtained.

[0100] [Example 1] Laminate P-1 The water-based ink (C-1) was diluted with water to a viscosity of 12 seconds using a Zahn cup #4. In a room temperature environment, a flexographic plate (a photosensitive resin plate manufactured by KODAK, FLEXCELNXH digital flexographic plate, plate thickness 1.14 mm, screen ruling 150 lpi) and an anilox roll (900 lpi 3 cc / m) were applied to the corona-treated surface of a corona-treated polypropylene substrate ("FOR" manufactured by Futamura Chemical Co., Ltd., thickness 20 μm, hereinafter referred to as OPP) as the substrate 1. 2 Using a flexographic printing machine (MIRAFLEXCM) equipped with a printer, diluted water-based ink (C-1) was printed at a printing speed of 200 m / min, an intercolor dryer at 100°C, and a tunnel dryer at 100°C to form a printed layer (first layer) with a thickness of 1 μm, thereby obtaining an intermediate laminate p-1 having a configuration of "substrate 1 / printed layer (first layer)." Next, at room temperature, a solventless adhesive AD-1 was applied to the printed layer (first layer) using a laminator using a solventless lamination method (hereinafter referred to as NS) to form an adhesive layer (first layer).The adhesive layer (first layer) was then bonded to a 30 μm-thick unstretched polypropylene film ("FCMN" manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as CPP) as the substrate 2, with the corona-treated surface in contact, to obtain a 1000 m long laminate.The lamination speed was 250 m / min, and the thickness of the adhesive layer (first layer) was 2 μm.In addition, a mark was made at the end of lamination at a lamination speed of 250 m / min to determine the evaluation position in the laminate appearance evaluation described below. The laminated body was wound up on a paper tube and stored in an environment of 40°C and 65% RH, and then removed after 48 hours to obtain laminate P-1, which had a structure of "substrate 1 / printing layer (first layer) / adhesive layer (first layer) / substrate 2."

[0101] [Examples 2 to 29, 31, 41, and 42, and Comparative Examples 1 to 3] Laminates P-2 to P-29, P-31, P-41, and P-42, and PP-1 to PP-3 Laminates P-2 to P-29, P-31, P-41, P-42, and PP-1 to PP-3 were obtained in the same manner as in Example 1, except that the water-based ink and adhesive were changed according to Tables 2-1 to 2-4.

[0102] [Example 30] Laminate P-30 The water-based ink (C-1) was diluted with water to a viscosity of 12 seconds using Zahn cup #4, and the water-based ink (W-1) was diluted with water to a viscosity of 12 seconds using Zahn cup #4. In a room temperature environment, a flexographic plate (a photosensitive resin plate manufactured by KODAK, FLEXCELNXH digital flexographic plate, plate thickness 1.14 mm, screen ruling 150 lpi) and an anilox roll (900 lpi 3 cc / m) were applied to the corona-treated surface of a corona-treated polypropylene substrate ("FOR" manufactured by Futamura Chemical Co., Ltd., thickness 20 μm, hereinafter referred to as OPP) as the substrate 1. 2Using a flexographic printing machine (MIRAFLEXCM) equipped with a flexographic printer, diluted water-based ink (C-1) was printed at a printing speed of 200 m / min, an intercolor dryer temperature of 100°C, and a tunnel dryer temperature of 100°C, to form a printed layer (first layer) with a thickness of 1 μm. Next, a water-based ink (W-1) was printed on the printed layer (first layer) at room temperature to form a printed layer (second layer) having a thickness of 1 μm. The printing machine and printing conditions used were the same as those used in the method for forming the printed layer (first layer). Next, at room temperature, a solventless adhesive AD-1 was applied to the printed layer (second layer) using a laminator using a solventless lamination method (hereinafter referred to as NS) to form an adhesive layer (first layer). The adhesive layer (first layer) was then bonded to a 30 μm-thick unstretched polypropylene film ("FCMN" manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as CPP) as the substrate 2, with the corona-treated surface in contact, to obtain a 1000 m long laminate. The lamination speed was 250 m / min, and the thickness of the adhesive layer (first layer) was 2 μm. A mark was placed at the end of lamination at a lamination speed of 250 m / min to determine the evaluation position for the laminate appearance evaluation described below. The laminated body was wound up on a paper tube and stored in an environment of 40°C and 65% RH. After 48 hours, it was removed to obtain laminate P-30, which had a structure of "substrate 1 / printed layer (first layer) / printed layer (second layer) / adhesive layer (first layer) / substrate 2."

[0103] [Example 32] Laminate P-32 At room temperature, the printed layer (first layer) of the intermediate laminate p-1 was coated with solvent-based adhesive AD-3, the solids content of which had been adjusted to 30% with ethyl acetate, using a dry lamination method (hereinafter referred to as DL). This formed an adhesive layer (first layer). The adhesive layer (first layer) was then bonded to a 30 μm-thick unstretched polypropylene film ("FCMN" manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as CPP) as the substrate 2, with the corona-treated surface in contact, to obtain a 1000 m long laminate. The lamination speed was 200 m / min, and the thickness of the adhesive layer (first layer) was 2.95 μm. A mark was placed at the end of lamination at a lamination speed of 200 m / min to determine the evaluation position for the laminate appearance evaluation described below. The laminated body was wound up on a paper tube and stored in an environment of 40°C and 65% RH, and then removed after 48 hours to obtain laminate P-32, which had a structure of "substrate 1 / printing layer (first layer) / adhesive layer (first layer) / substrate 2."

[0104] [Example 33] Laminate P-33 At room temperature, adhesive AD-5 (manufactured by Toyo-Morton Co., Ltd., EL-420, imine-based adhesive) was printed onto the printed layer (first layer) of intermediate laminate p1 using an extrusion laminator equipped with a gravure plate with a plate depth of 15 μm at a printing speed of 150 m / min and an in-line oven temperature of 50°C to form an adhesive layer (first layer). Subsequently, polyethylene resin (AD-4) melted at a resin temperature of 315°C was applied onto the adhesive layer (first layer) using the laminator using an extrusion lamination method (hereinafter referred to as EL) to form an adhesive layer (second layer). The adhesive layer (second layer) was then bonded to the corona-treated surface of a 30 μm-thick unstretched polypropylene film (manufactured by Futamura Chemical Co., Ltd., "FCMN", hereinafter referred to as CPP) as substrate 2, to obtain a laminate 1000 m long. The lamination speed was 250 m / min, the thickness of the adhesive layer (first layer) was 0.5 μm, and the thickness of the adhesive layer (second layer) was 15 μm. The adhesive layer (first layer) and adhesive layer (second layer) were formed in-line. Furthermore, a mark was placed at the end of lamination at a lamination speed of 250 m / min to determine the evaluation position in the laminate appearance evaluation described below. The laminated body was wound up on a paper tube and stored in an environment of 40°C and 65% RH, and then removed after 48 hours to obtain laminate P-33, which had a structure of "substrate 1 / printing layer (first layer) / adhesive layer (first layer) / adhesive layer (second layer) / substrate 2."

[0105] [Examples 34 and 35] Laminates P-34 and P-35 Laminates P-34 and P-35 were obtained in the same manner as in Example 33, except that the adhesive was changed according to Table 2. The adhesives used are as follows: AD-6: EL-530A / EL-530B (isocyanate adhesive) was used. AD-7: Toyo Morton EL-451 (butadiene adhesive)

[0106] [Examples 36 to 40] Laminates P-36 to P-40 Laminates P-36 to P-40 were obtained in the same manner as in Example 1, except that the substrate 1 and the substrate 2 were changed according to Table 2-4. The substrates used are as follows: PET: Corona-treated polyester (PET) substrate (Toyobo "E5102", thickness 12 μm) NY: Corona-treated nylon substrate (Unitika "Emblem ON-RT", thickness 15 μm) MDOPE: Corona-treated uniaxially oriented polyethylene (MDOPE) substrate (Futamura Chemical Co., Ltd. "PE3K-H", thickness 25 μm) LLDPE: 50 μm thick polyethylene film (Mitsui Chemicals Tohcello "TUX-FCD") VMCPP: 25 μm thick aluminum-coated unstretched polypropylene film (Toray Industries, Inc. "2703")

[0107] <Evaluation of laminate> The resulting laminate was evaluated as follows, and the results are shown in Tables 2-1 to 2-4.

[0108] <Laminate appearance (streaky stains)> The obtained laminate was unwound from the paper tube, and the appearance was evaluated according to the following criteria at a point 10 m from the end of lamination toward the start of lamination (evaluation range: the entire range from the 10 m point to the 11 m point). A to C are ranges that pose no practical problems. A: No streaks (very good) B: Streaky stains occurred, and the stained area was less than 5% (good). C: Streaky stains occurred, and the stained area was 5% or more and less than 10% (usable). D: Streaky stains occur and stain area is 10% or more (cannot be used)

[0109] <Laminate appearance (ink bleed)> The obtained laminate was unwound from the paper tube, and the appearance was evaluated according to the following criteria at a point 10 m from the end of lamination toward the start of lamination (evaluation range: the entire range from the 10 m point to the 11 m point). A to C are ranges that pose no practical problems. A: No ink loss and uniform color throughout (very good) B: Ink loss occurred, and the ink loss area was less than 5% (good) C: Ink loss occurred, and the ink loss area was 5% or more but less than 10% (usable). D: Ink loss occurred and the ink loss area was 10% or more (unusable)

[0110] <Lamination strength> The resulting laminate was cut into a 15 mm wide and 300 mm long test piece. Based on JIS K6854, the T-peel strength [N / 15 mm] between substrate 1 and substrate 2 was measured using an Instron tensile tester at a temperature of 20°C and a relative humidity of 65% at a peel rate of 300 mm / min. The measurement was performed five times, and the average value was used to evaluate the results according to the following criteria. The resulting laminate was printed at a high speed of 200 m / min using printing ink, which shortened the time the printed layer spent in the in-line oven. This means that if the printed layer had poor film-forming properties, the laminate strength would tend to decrease. Therefore, these conditions are excessive compared to when a laminate is produced using low-speed printing. A to C are ranges that pose no practical problems. A: 1.5 [N / 15mm] or more (very good) B: 1.0 [N / 15mm] or more, less than 1.5 [N / 15mm] (good) C: 0.5 [N / 15mm] or more, less than 1.0 [N / 15mm] (usable) D: Less than 0.5 [N / 15mm] (unusable)

[0111] [Table 2-1]

[0112] [Table 2-2]

[0113] [Table 2-3]

[0114] [Table 2-4]

[0115] According to the evaluation results, in Comparative Example 1, the printed layer did not contain at least one compound selected from the group consisting of acetylene-based compounds, alcohol alkoxylate-based compounds, and siloxane-based compounds, but instead contained a fluorine-based compound, resulting in an unevenly formed adhesive layer and insufficient laminate strength. In Comparative Example 2, the printed layer did not contain at least one compound selected from the group consisting of acetylene-based compounds, alcohol alkoxylate-based compounds, and siloxane-based compounds, resulting in an unevenly formed printed layer, ink bleed through the laminate, and poor laminate appearance. In Comparative Example 3, the acrylic resin content in 100% by mass of the printed layer was less than 5% by mass, resulting in streaky stains on the laminate, poor laminate appearance, and insufficient laminate strength. On the other hand, in all of the Examples, streaky stains and ink bleed through the laminate did not occur, meaning that both excellent laminate appearance and high laminate strength were achieved.

Claims

1. A method for producing a laminate having a substrate 1, a printing layer, an adhesive layer, and a substrate 2 in this order, forming the printing layer on the substrate 1 by gravure printing or flexographic printing with a printing ink containing an acrylic resin and the compound (A); and applying a solvent-free adhesive onto the printing layer to form the adhesive layer. the compound (A) includes at least one selected from the group consisting of an acetylene-based surfactant compound, an alcohol alkoxylate-based surfactant compound, and a siloxane-based surfactant compound; The acrylic resin has an acid value of 120 to 250 mgKOH / g and a glass transition temperature of 0 to 80°C. A method for manufacturing a laminate.

2. The method for producing a laminate according to claim 1, wherein the adhesive layer has a glass transition temperature of 60°C or lower.

3. 3. The method for producing a laminate according to claim 1, wherein the acrylic resin has a minimum film-forming temperature, and the minimum film-forming temperature is 50°C or lower.

4. The method for producing a laminate according to claim 1 or 2, wherein the printed layer further contains a hydrazine derivative.

5. The method for producing a laminate according to claim 1 or 2, wherein the printed layer further contains an antifoaming agent, and the content of the antifoaming agent is 0.01 to 2% by mass relative to 100% by mass of the printed layer.

6. 3. The method for producing a laminate according to claim 1, wherein the printed layer further contains an extender pigment, and the extender pigment is at least one selected from the group consisting of barium sulfate, calcium carbonate, kaolin clay, and silica.

7. The method for producing a laminate according to claim 1 or 2, wherein the substrate 1 comprises an olefin-based resin.

8. The method for producing a laminate according to claim 1 or 2, wherein the printing ink further contains an amine compound.

9. The method for producing a laminate according to claim 1 or 2, wherein the printing ink further contains an organic solvent having a boiling point of 130°C or higher.

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