Composition for forming anchor coat layer and laminate having anchor coat layer

Abstract

To provide a laminate (for example, an overlap film) having an anchor coat layer formed by use of an aqueous anchor coat layer-forming composition, the laminate being capable of enhancing various properties including scratch resistance, wrinkle resistance, blocking resistance, and heat resistance while ensuring adhesion as a laminated film, and to provide an aqueous anchor coat layer-forming composition for forming an anchor coat layer that constitutes the laminate.SOLUTION: An anchor coat layer-forming composition for forming an anchor coat layer disposed between a heat shrinkable film and an ink layer is a composition containing a binder resin and water, wherein the binder resin contains a chlorinated polyolefin resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for forming an anchor coat layer and a laminate having an anchor coat layer. [Background technology]

[0002] Overwrap film is a type of packaging material that is attached to various adherends, such as containers containing food or daily necessities, by heat shrinking. For example, many cup containers containing instant noodles are wrapped and packaged with an overlap film provided with a design print layer such as a picture, trademark, product description, etc. Incidentally, an overlap film using a heat-shrinkable polyolefin film is known. If a polyolefin film is corona discharge treated, problems can arise during post-processing, such as when the film is sealed and packaged using a fusing heater, as the corona discharge treatment can cause the sealed area to peel off, making packaging difficult. For this reason, it is necessary to print without corona discharge treatment. If corona discharge treatment is not performed, a possible configuration is to provide an anchor coat layer between the heat-shrinkable polyolefin film and the design print layer in order to improve adhesion between the polyolefin film and the design print layer. For example, an overlap film has been proposed that has a heat-shrinkable polyolefin film, an anchor coat layer laminated adjacent to the heat-shrinkable polyolefin film, and a design print layer laminated adjacent to the anchor coat layer (see, for example, Patent Document 1). Patent Document 1 describes an anchor coat layer formed by applying a coating liquid in which a chlorinated polyolefin resin is dissolved in an organic solvent and drying the coating film. Patent Document 1 also describes a design print layer formed on the anchor coat layer using a solvent ink containing a urethane resin as a binder resin, a colorant, and a solvent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-141403 Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Document 1, solvent-based anchor coating agents have traditionally been used to form anchor coats. However, in recent years, there has been a desire to switch to water-based agents for environmental conservation and health and safety reasons. For environmental conservation and safety and hygiene reasons, it is desirable to use water-based inks for the ink (printing layer), and there is also a need to provide anchor coating agents that have excellent adhesion when water-based inks are used. If the anchor coating agent and ink are water-based, it can also reduce the deterioration over time of the flexographic plates used during printing. Therefore, an object of the present invention is to provide a laminate (e.g., an overlap film) having an anchor coat layer formed using an aqueous anchor coat layer-forming composition, which can improve various properties such as scratch resistance, crumple resistance, blocking resistance, and heat resistance while ensuring adhesion as a laminate film, and to provide an aqueous anchor coat layer-forming composition for forming the anchor coat layer that constitutes the laminate. [Means for solving the problem]

[0005] As a result of intensive research into solving the above-mentioned problems, the present inventors have found that by incorporating a binder resin containing a chlorinated polyolefin resin and water into a composition for forming an anchor coat layer, a laminate (e.g., an overlap film) having an anchor coat layer formed from the aqueous composition for forming an anchor coat layer can solve the above-mentioned problems of the present invention, and have thus completed the present invention.

[0006] That is, the present invention includes the following aspects. [1] A composition for forming an anchor coat layer to be disposed between a heat-shrinkable film and an ink layer, Contains a binder resin and water, The composition for forming an anchor coat layer, wherein the binder resin contains a chlorinated polyolefin resin. [2] The composition for forming an anchor coat layer according to [1], wherein the binder resin further contains at least one resin selected from the group consisting of polyurethane resin, acrylic resin, styrene-maleic anhydride resin, and rosin resin. [3] The composition for forming an anchor coat layer according to [1] or [2], further comprising at least one of wax and silica. [4] A laminate comprising a heat-shrinkable film, an anchor coat layer, and an ink layer laminated in this order, The anchor coat layer is a laminate formed using the composition for forming an anchor coat layer according to any one of [1] to [3]. [5] The laminate according to [4], wherein the heat-shrinkable film is a polyolefin film. [6] The laminate according to [4] or [5], wherein the ink layer is a layer formed using an aqueous ink composition. [7] The laminate according to [6], wherein the ink layer contains at least one resin selected from the group consisting of a urethane resin and an acrylic resin. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a laminate (e.g., an overlap film) having an anchor coat layer formed using an aqueous anchor coat layer-forming composition, which can improve various properties such as scratch resistance, crumple resistance, blocking resistance, and heat resistance while ensuring adhesion as a laminate film, and an aqueous anchor coat layer-forming composition for forming the anchor coat layer that constitutes the laminate. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described in detail below. Note that the following explanation of the constituent elements is an example for explaining the present invention, and the present invention is not limited to these contents.

[0009] (Anchor Coat Layer Forming Composition) The anchor coat layer-forming composition of the present invention is a composition used to form an anchor coat layer disposed between a heat-shrinkable film and an ink layer. A detailed description of a "laminate" (eg, an overlap film) having a heat-shrinkable film, an ink layer, and an anchor coat layer disposed therebetween will be provided below. The anchor coat layer-forming composition of the present invention contains a binder resin and water. The anchor coat layer-forming composition of the present invention is a water-based (aqueous) composition rather than an organic solvent-based composition. The binder resin contains at least a chlorinated polyolefin resin. In the present invention, by adding at least a chlorinated polyolefin resin as a binder resin to an aqueous anchor coat layer-forming composition containing a binder resin and water, it is possible to produce a laminate that has the adhesion required for a laminate film and can also improve various properties such as scratch resistance, crumpling resistance, blocking resistance, and heat resistance, as will be shown in the examples below. In addition, an ink layer (printed layer) formed with a water-based ink has good adhesion to an anchor coat layer formed using a water-based anchor coat layer-forming composition.

[0010] <Binder resin> The binder resin according to the present invention contains at least a chlorinated polyolefin resin. The binder resin according to the present invention may further contain other binder resins in addition to the above-mentioned chlorinated polyolefin resin. Other binder resins according to the present invention include: There are no particular limitations, and binder resins used in general water-based liquid printing inks can be used. for example, Polyurethane resin; rosin-based resins; Polyvinyl alcohols; Polyvinylpyrrolidones; Polyacrylic acid; Acrylic copolymers such as acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer; Styrene-acrylic acid resins such as styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, and styrene-α-methylstyrene-acrylic acid-acrylic acid alkyl ester copolymer; Styrene-maleic acid; Styrene-maleic anhydride; Vinylnaphthalene-acrylic acid copolymer; Vinylnaphthalene-maleic acid copolymer; Vinyl acetate copolymers such as vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinylethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer; and salts thereof. The above-mentioned other examples of binder resins can be used in combination as appropriate to satisfy the desired physical properties.

[0011] Among these, the other binder resin according to the present invention is preferably at least one of polyurethane resin, acrylic resin, styrene-maleic anhydride resin, and rosin resin, because of their easy availability.

[0012] The binder resin is contained in the anchor coat layer forming composition in an amount of preferably 10.0 to 50.0% by mass, and more preferably 15.0 to 35.0% by mass.

[0013] <<Chlorinated polyolefin resin>> The anchor coat layer-forming composition contains at least a chlorinated polyolefin resin as a binder resin component. The chlorinated polyolefin resin according to the present invention is not particularly limited as long as it is a polyolefin resin in which at least a portion of the hydrogen atoms have been substituted with chlorine atoms. Examples of chlorinated polyolefin resins include chlorinated polyethylene, chlorinated polypropylene, and acrylic-modified or urethane-modified chlorinated polyolefin resins obtained by modifying chlorinated polyethylene or chlorinated polypropylene with an acrylic polymer or urethane polymer having an ethylenically unsaturated bond. The chlorinated polyolefin resin is preferably used in the form of an emulsion of the chlorinated polyolefin resin, which is obtained by chlorinating a polyolefin resin and emulsifying it. The weight average molecular weight of the chlorinated polyolefin resin is preferably from 5,000 to 300,000, more preferably from 40,000 to 220,000, and even more preferably from 50,000 to 150,000. Furthermore, the chlorinated polyolefin resin preferably has a chlorine content of 15 to 45% by mass to improve adhesion to substrates. From the viewpoint of solubility in organic solvents, the chlorine content is more preferably 26 to 43% by mass. Here, the chlorine content refers to the mass % content of chlorine atoms in 100% by mass of the chlorinated polyolefin resin. The chlorinated polyolefin resin is contained in the anchor coat layer forming composition in an amount of preferably 10.0 to 50.0 mass %, more preferably 15.0 to 35.0 mass %, in terms of solid content. The chlorinated polyolefin resin is preferably contained in an amount of 50.0 to 95.0 mass % relative to 100 mass % of the binder resin in the anchor coat layer-forming composition, and more preferably contained in an amount of 60.0 to 80.0 mass % in terms of solid content.

[0014] Among the resins exemplified above as other binder resins, some resins will be described below.

[0015] <<Polyurethane resin>> The polyurethane resin is not particularly limited as long as it is a polyurethane resin obtained by reacting a polyol with a polyisocyanate. As the polyol, for example, various known polyols generally used in the production of polyurethane resins can be used, and one or more of them may be used in combination. For example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, Saturated or unsaturated low molecular weight polyols (1) such as ethylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, and pentaerythritol; these low molecular weight polyols (1) and sebacic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, and trimellitic acid polyester polyols (2) obtained by dehydration condensation or polymerization of polycarboxylic acids such as methyl acrylate, pyromellitic acid, or their anhydrides; polyester polyols (3) obtained by ring-opening polymerization of cyclic ester compounds, for example, lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone); polycarbonate polyols (4) obtained by reacting the above-mentioned low-molecular-weight polyols (1) with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene, or the like; polybutadiene glycols (5); glycols (6) obtained by adding ethylene oxide or propylene oxide to bisphenol A; and acrylic polyols (7) obtained by copolymerizing, in one molecule, one or more hydroxyethyl groups, hydroxypropyl acrylate, hydroxybutyl acrylate, etc., or the corresponding methacrylic acid derivatives, with, for example, acrylic acid, methacrylic acid, or an ester thereof.

[0016] Examples of polyisocyanates include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are generally used in the production of polyurethane resins. For example, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene Aromatic polyisocyanates such as zenediisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3-3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and diphenylmethane-2,4-diisocyanate;Aliphatic or alicyclic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanatomethyl)cyclohexane, 1,4-di(isocyanatomethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate can be used. These polyisocyanates can be used alone or in combination of two or more. Among these, these diisocyanate compounds can be used alone or in combination of two or more. Chain extenders can also be used. Examples of chain extenders include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, and dicyclohexylmethane-4,4'-diamine, as well as amines having a hydroxyl group in the molecule, such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine. These chain extenders can be used alone or in combination of two or more. Monovalent active hydrogen compounds can also be used as end-capping agents for the purpose of terminating the reaction. Examples of such compounds include dialkylamines such as di-n-butylamine and alcohols such as ethanol and isopropyl alcohol. Furthermore, when it is particularly desired to introduce carboxyl groups into the polyurethane resin, amino acids such as glycine and L-alanine can be used as reaction terminators. These end-capping agents can be used alone or in combination. The weight average molecular weight of the polyurethane resin is preferably 10,000 to 100,000, and more preferably in the range of 15,000 to 80,000.

[0017] <<Acrylic resin>> The acrylic resin is not particularly limited as long as it is a copolymer of polymerizable monomers whose main component is a (meth)acrylic acid ester. Examples of polymerizable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, iso-octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, iso-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and phenoxyethyl (meth)acrylate. The polymerization method is also not particularly limited, and those obtained by known methods such as bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used. The weight average molecular weight of the acrylic resin is preferably 5,000 to 200,000, and more preferably in the range of 10,000 to 100,000.

[0018] <<Rosin-based resin>> The rosin-based resin can be any commonly used rosin and / or a commonly used rosin derivative. Specifically, the rosin or rosin derivative is a rosin or a carboxyl group-containing derivative thereof. Examples of the rosin include gum rosin, wood rosin, tall oil rosin, disproportionated rosin, hydrogenated rosin, and polymers thereof. Examples of the rosin derivative include a carboxyl group-containing derivative such as a rosin derivative to which an unsaturated carboxylic acid such as maleic acid, fumaric acid, itaconic acid, or crotonic acid has been added. In the present invention, the rosin-based resin is preferably a rosin-based acid resin. In the present invention, it is particularly preferable to use a rosin-modified maleic acid resin, which is a maleic acid derivative of rosin, or a rosin-modified fumaric acid resin, which is a fumaric acid derivative of rosin. The rosin-modified maleic acid resin or rosin-modified fumaric acid resin used in the present invention is not particularly limited, and any known rosin-modified maleic acid resin or rosin-modified fumaric acid resin can be used. The rosin-modified maleic acid resin or rosin-modified fumaric acid resin preferably has an acid value of 25 mgKOH / g or more and 320 mgKOH / g or less, and particularly preferably has an acid value of 100 mgKOH / g or more and 320 mgKOH / g or less. As the rosin-based acid resin, for example, the Marquid series manufactured by Arakawa Chemical Industries, Ltd. can be used.

[0019] <Water> The water used in the present invention may be water alone or may be used as a mixed solvent in which water is mixed with a water-soluble solvent that is miscible with water. The main component of the solvent components in the composition for forming an anchor coat layer is water, but as long as the effects of the present invention are achieved when used in an aqueous anchor coat layer, a small amount of water-soluble solvent may be contained in addition to water. The proportion of water in the solvent component is preferably 50.0 to 100.0% by mass, for example, in 100% by mass of the solvent component.

[0020] Specific examples of water include natural water, purified water, distilled water, ion-exchanged water, pure water, and ultrapure water (for example, Milli-Q water). Examples of water-soluble solvents include alcohol solvents such as methanol, ethanol, n-propanol, and isopropanol; ketone solvents such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol, and propylene glycol; alkyl ethers of polyalkylene glycols; and lactam solvents such as N-methyl-2-pyrrolidone. In the present invention, water alone may be used, or a mixture of water and a water-soluble solvent that is miscible with water may be used. However, from the viewpoints of safety and environmental impact, water alone is more preferred.

[0021] The anchor coat layer-forming composition of the present invention may contain various additives in addition to the binder resin and water, if necessary. The various additives include a leveling agent, an antifoaming agent, a wax, and silica. For example, the anchor coat layer forming composition may contain at least one of wax and silica.

[0022] <Leveling agent> Examples of leveling agents include alcohol alkoxylate-based leveling agents, acetylene diol-based leveling agents, acrylic polymer-based leveling agents (e.g., Polyflow WS-314, manufactured by Kyoeisha Chemical Co., Ltd.), and modified silicone-based leveling agents (e.g., Polyflow KL-401, manufactured by Kyoeisha Chemical Co., Ltd.). Specific examples of alcohol alkoxylate leveling agents include alcohol ethoxylate and alcohol polyethoxylate, and examples of acetylene diol leveling agents include acetylene diol ethoxylate. The total amount of the leveling agent used is preferably 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and even more preferably 0.1 to 1% by mass, of the total amount of the anchor coat layer-forming composition. If the amount of the leveling agent added is 0.1% by mass or more of the total amount of the anchor coat layer-forming composition, the wettability with the substrate is improved and adhesion to the substrate can be maintained. If the amount of the leveling agent added is 5% by mass or less of the total amount of the anchor coat layer-forming composition, the abrasion resistance, water abrasion resistance, and scratch resistance will not be reduced.

[0023] <Antifoaming agent> In order to suppress foaming during printing, it is preferable to use an antifoaming agent. The antifoaming agent may be a silicone-based antifoaming agent or a non-silicone-based antifoaming agent. Specific examples of silicone-based antifoaming agents include DOWSIL FS Antifoam 013A (manufactured by Dow-Toray Co., Ltd.).

[0024] <Wax> The anchor coat layer forming composition may contain a wax. As the wax, for example, it is preferable to use polyolefin wax or fatty acid amide wax. Examples of polyolefin waxes include oxidized polyethylene wax and oxidized polypropylene wax. Examples of fatty acid amide waxes include saturated fatty acid amides such as stearic acid amide and palmitic acid amide, unsaturated fatty acid amides such as erucic acid amide, substituted amides, and aromatic amides.

[0025] The anchor coat layer can be formed by applying the anchor coat layer-forming composition of the present invention to a substrate such as a heat shrinkable film, and drying the coating film. The thickness of the anchor coat layer is not particularly limited, but is preferably 0.01 μm to 3 μm, and more preferably 0.05 μm to 2 μm, for example.

[0026] (Laminate) The laminate of the present invention has an anchor coat layer formed using the anchor coat layer-forming composition of the present invention. The laminate of the present invention is formed by laminating a heat-shrinkable film, an anchor coat layer, and an ink layer in this order.

[0027] <Layer structure of laminate> As described above, the laminate of the present invention is formed by laminating the heat-shrinkable film / anchor coat layer / ink layer in this order. By using the composition for forming an anchor coat layer of the present invention, adhesion between the anchor coat layer and the heat-shrinkable film substrate is good, and various properties such as scratch resistance, crumple resistance, blocking resistance, and heat resistance are also improved. A more preferred embodiment of the laminate of the present invention is, for example, a laminate in which a heat-shrinkable polyolefin film, an anchor coat layer, a design print layer, and a second print layer, a white print layer, are laminated in this order. For example, the anchor coat layer is provided directly in contact with the back surface of the heat-shrinkable polyolefin film, the design printing layer is provided directly in contact with the back surface of the anchor coat layer, and the second printing layer (white printing layer) is provided directly in contact with the back surface of the design printing layer.

[0028] <Heat-shrinkable film> The heat-shrinkable film is preferably a heat-shrinkable polyolefin film. Heat shrinkability refers to the property of shrinking when heated to a required temperature (for example, 70°C to 160°C). A heat shrinkable film heat shrinks in at least one direction (first direction) within its plane, and preferably in two orthogonal directions (first direction and second direction) within its plane.

[0029] The heat-shrinkable polyolefin film is a colorless or colored transparent heat-shrinkable film in which the main component resin constituting the film is a polyolefin-based resin. The heat-shrinkable polyolefin film is not particularly limited, and examples thereof include a polypropylene film made of polypropylene and a polyethylene film made of polyethylene, with a polypropylene film being preferred. Examples of polypropylene include propylene homopolymers and propylene-ethylene copolymers, and examples of polyethylene include polyethylene homopolymers and polyethylene copolymers. The thickness of the heat-shrinkable film is not particularly limited, and is, for example, preferably 10 μm to 60 μm, more preferably 12 μm to 40 μm.

[0030] <Ink layer> The ink layer according to the present invention is preferably an ink layer formed using a water-based ink (also called a water-based ink composition). In the laminate of the present invention, the anchor coat layer is an aqueous anchor coat layer formed from the aqueous anchor coat layer-forming composition described above, and therefore has excellent adhesion to the aqueous ink layer. The ink layer according to the present invention may be a single layer or may be formed from two or more layers. For example, the ink layer may be composed of two or more ink layers, including a design printed layer that displays various design displays such as a product name, a pattern, ingredient information, a barcode, a two-dimensional code, and warnings, and a second printed layer that is colorless and transparent, colored and transparent, a single color without a pattern, or multiple colors without a pattern. The design print layer and the second print layer may be made up of a plurality of layers.

[0031] As described above, the design print layer is a print layer on which various design displays such as product names, pictures, ingredient labels, bar codes, two-dimensional codes, and warnings are displayed. The design print layer includes a binder resin and a colorant. As the colorant, a conventionally known pigment or dye can be used.

[0032] As described above, the second printed layer is a colorless and transparent, colored and transparent, a single-colored and patternless printed layer, or a multicolored and patternless printed layer. The second print layer includes a binder resin and an inorganic pigment. Examples of inorganic pigments include colored pigments such as titanium oxide, zinc oxide, aluminum oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, carbon black, and graphite; extender pigments such as silica, calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide, and talc; and pearl pigments such as mica and metal oxide-coated mica. These inorganic pigments can be used alone or in combination. Among these, the inorganic pigment preferably contains at least one selected from metal oxides such as titanium oxide, zinc oxide, and aluminum oxide, silica, calcium carbonate, and mica, and more preferably contains titanium oxide.

[0033] The colorant contained in the design print layer is preferably, for example, a pigment, and examples thereof include inorganic pigments and organic pigments used in general inks, paints, recording agents, etc. 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 carbon black-based pigments. Other examples include carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, cromophtal yellow, cromophtal red, phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, daylight fluorescent pigments, etc. In addition, both non-acid-treated pigments and acid-treated pigments can be used.

[0034] Whether it is the design printing layer or the second printing layer, the ink (also called the ink composition) that forms the printing layer is composed of a colorant such as the pigment mentioned above, a binder resin, a solvent, and various other additives as necessary.

[0035] The binder resin contained in the water-based ink according to the present invention may be a water-dispersible or water-soluble resin, such as an acrylic resin or urethane resin that is used in general water-based liquid printing inks. The acrylic resin is not particularly limited, and examples thereof include a homopolymer or copolymer of (meth)acrylate, and a copolymer of a vinyl monomer copolymerizable with (meth)acrylate. Furthermore, a copolymer having an acid value is preferred for the purpose of imparting water dispersibility or water solubility. The urethane resin is not particularly limited, and examples thereof include urethane resins obtained by reacting a polyol such as polyether polyol, polyester polyol, or polycarbonate polyol with a polyol having a hydrophilic group such as an anionic group, a cationic group, a polyoxyethylene group, or a polyoxyethylene-polyoxypropylene group, and a polyisocyanate. The weight-average molecular weight of the urethane resin is not particularly limited, but generally, it should be 5,000 to 200,000, and preferably 20,000 to 150,000. Examples of the solvent (aqueous medium) contained in the aqueous ink include water and a mixed solvent obtained by mixing water with a water-soluble solvent that is miscible with water. Examples of water-soluble solvents include alcohol solvents such as methanol, ethanol, n-propanol, and isopropanol; ketone solvents such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol, and propylene glycol; alkyl ethers of polyalkylene glycols; and lactam solvents such as N-methyl-2-pyrrolidone. In the present invention, water alone may be used, or a mixture of water and a water-soluble solvent that is miscible with water may be used. However, from the viewpoints of safety and environmental impact, water alone is more preferred.

[0036] As described above, the ink composition may contain various additives, and may further contain, for example, at least one of wax and silica. The wax contained in the ink composition is as described above in the section <Wax> of (Anchor coat layer forming composition).

[0037] The design print layer can be formed by printing an ink containing a binder resin and a colorant using a known printing method. The second printed layer can be formed by printing an ink containing a binder resin and an inorganic pigment using a known printing method. For example, known printing methods include printing with liquid printing inks such as gravure inks and flexographic inks. The thickness of the design print layer is not particularly limited, but is preferably, for example, 0.1 μm to 5 μm, and the thickness of the second print layer is not particularly limited, but is preferably, for example, 0.5 μm to 5 μm.

[0038] <<Preferred embodiment of the ink layer>> As a preferred embodiment of the laminate including the ink layer, for example, An example of the structure is a heat-shrinkable film / aqueous anchor coat layer / aqueous ink layer. A method for producing an aqueous ink involves, for example, dispersing a pigment and water alone, or a mixture of water and a water-soluble solvent, a pigment dispersant, an antifoaming agent, etc., in a disperser to obtain a pigment dispersion. A binder resin, water, or water and a water-soluble solvent, and optionally additives such as a leveling agent, are added to the obtained pigment dispersion, followed by stirring and mixing to obtain an aqueous ink composition. A bead mill, Eiger mill, sand mill, gamma mill, attritor, or the like, which are commonly used in the production of gravure and flexographic printing inks, can be used as the disperser for production.

[0039] <Method of manufacturing laminate> The laminate of the present invention can be produced, for example, as follows. The anchor coat layer-forming composition is applied to a heat-shrinkable film substrate, and the coating film is dried to form the anchor coat layer. An ink (ink composition) is applied onto the anchor coat layer, and the coating film is dried to form an ink layer. Furthermore, by changing the type of ink, multiple ink layers (printed layers) can be formed in sequence, from the first ink layer (first printed layer) to the second ink layer (second printed layer), and then, as appropriate, the third ink layer (third printed layer), the fourth ink layer (fourth printed layer), etc.

[0040] <Application of laminates> The laminate of the present invention is used, for example, as an overwrap film for overwrap packaging, particularly for packaging cup noodles. The overlap film according to the present invention is used by being attached to various adherends by heat shrinking. An overlap film is used as a protective film by wrapping it around a single adherend, or as a protective and bundling film by wrapping it around an assembly of multiple adherends. The adherend is not particularly limited, and may be a container in which an article is stored, or the article itself. Examples of the substrate include containers containing instant foods such as instant noodles, dairy products such as yogurt, luxury foods such as jellies and puddings, beverages, seasonings, sanitary products such as shampoo, and fresh foods such as meat; and articles themselves such as dry batteries. When the adherend is a container containing an article, the external shape of the container is not particularly limited, and examples thereof include cylindrical shapes such as a cylindrical, elliptical, or rectangular cylinder; inverted truncated cone shapes such as an inverted truncated elliptical cone shape or an inverted truncated square pyramid; and irregular shapes such as a gourd shape. The material of the container is not particularly limited, and examples thereof include synthetic resin, foamed synthetic resin, metal, glass, ceramic, and wood.

[0041] <<Specific uses of overlap film>> In mechanical manufacturing processes, packages in which an adherend is wrapped in overlap film are usually produced as follows: For example, a long overlap film is formed into a cylindrical shape so as to wrap around the adherend, and both side edges along the MD (longitudinal direction) are heat-sealed, and the long overlap film formed into a cylindrical shape wrapping the adherend is thermally sealed in the TD on both the front and rear sides of the adherend, and then the overlap film, sealed on three sides with the adherend inside, is heated to heat shrink the package, thereby obtaining a package. [Example]

[0042] The present invention will be described in more detail below using examples. Of course, the present invention should not be limited to the scope of these examples. Hereinafter, "parts" and "%" are by mass unless otherwise specified.

[0043] (Preparation of various compositions) As a water-based composition for forming an anchor coat layer, a water-based anchor coat varnish of Preparation Example-AC1 shown in Table 1 below was prepared. To prepare a reference example, an oil-based anchor coat varnish of Preparation Example-AC2 shown in Table 2 below was prepared as an oil-based composition for forming an anchor coat layer. To prepare a reference example, an aqueous anchor coat varnish of Preparation Example-AC3 or Preparation Example-AC4 shown in Table 3 below was prepared, which is an aqueous anchor coat layer-forming composition, but uses a urethane resin or an acrylic resin as the binder resin instead of a chlorinated polypropylene resin. As the inks, water-based color inks of Preparation Example Color 1 to Preparation Example Color 2 shown in Table 4 below were prepared. As the inks, water-based white inks of Preparation Example-White 1 to Preparation Example-White 2 shown in Table 5 below were prepared.

[0044] [Table 1]

[0045] The raw materials used in the table are as follows: Chlorinated polypropylene resin: Commercially available aqueous chlorinated polypropylene resin solution with 30% solids. Leveling agent: Acetylene diol ethoxylate Antifoaming agent: DOWSIL FS Antifoam 013A (manufactured by Dow Toray Industries, Inc.)

[0046] <Preparation Example - AC1> 83.8 parts of a commercially available chlorinated polyolefin resin with a solid content of 30% was mixed with 10.0 parts of water, 3.0 parts of isopropyl alcohol, 3.0 parts of a leveling agent, and 0.2 parts of an antifoaming agent and stirred to prepare Preparation Example-AC1.

[0047] [Table 2]

[0048] The raw materials used in the table are as follows: Chlorinated polypropylene resin: Nippon Paper Industries Co., Ltd. "Super Chlon 360T, 60% solids" Rosin-modified maleic acid resin: "Marquid No. 31" manufactured by Arakawa Chemical Industries, Ltd. Ketone formaldehyde resin: Commercially available 100% solid ketone formaldehyde resin Cyclized rubber: Commercially available cyclized rubber with 100% solids content Silica: Fuji Silysia Chemical "Sylysia 436"

[0049] <Preparation example-AC2> 14.1 parts of chlorinated polyolefin resin solid content, 4.7 parts of rosin-modified maleic acid resin solid content, 0.9 parts of ketone formaldehyde resin solid content, 1.1 parts of cyclized rubber solid content, 37.7 parts of methylcyclohexane, 19.0 parts of normal propyl acetate, 11.5 parts of normal propyl alcohol, and 1.5 parts of silica were stirred to prepare Preparation Example-AC2.

[0050] [Table 3]

[0051] The raw materials used in the table are as follows: Water-based urethane resin solution: Taisei Fine Chemical Co., Ltd. "Acrit WBR-016U" Water-based acrylic resin solution: BASF "JONCRYL PDX-7741" Leveling agent: Acetylene diol ethoxylate Antifoaming agent: DOWSIL FS Antifoam 013A (manufactured by Dow Toray Industries, Inc.)

[0052] <Preparation example-AC3> A commercially available aqueous urethane resin solution containing 30% solids containing water was used as the aqueous urethane resin solution. 83.8 parts of this product, 10.0 parts of water, 3.0 parts of isopropyl alcohol, 3.0 parts of leveling agent, and 0.2 parts of antifoaming agent were mixed and stirred to produce Preparation Example-AC3.

[0053] <Preparation example-AC4> A commercially available aqueous acrylic resin solution containing 30% solids containing water was used as the aqueous acrylic resin solution. 83.8 parts of this product, 10.0 parts of water, 3.0 parts of isopropyl alcohol, 3.0 parts of leveling agent, and 0.2 parts of antifoaming agent were mixed and stirred to prepare Preparation Example-AC4.

[0054] [Table 4]

[0055] In the table, the following raw materials were used: Carbon black: CABOT "REGAL 330R Carbon Black" Water-based urethane resin solution: Taisei Fine Chemical Co., Ltd. "Acrit WBR-016U" Water-based acrylic resin solution: BASF "JONCRYL PDX-7741" Polyethylene wax: Mitsui Chemicals "Chemipearl W-400"

[0056] <Preparation Example - Color 1> 20.0 parts of carbon black, 48.8 parts of a commercially available aqueous urethane resin solution with a solid content of 30% containing water, 6.3 parts of normal propyl alcohol, and 23.0 parts of water were mixed and kneaded, and 1.9 parts of polyethylene wax was added to produce Preparation Example - Color 1.

[0057] <Preparation Example - Color 2> 20.0 parts of carbon black, 48.8 parts of a commercially available aqueous acrylic resin solution with a solid content of 30% containing water, 6.3 parts of normal propyl alcohol, and 23.0 parts of water were mixed and kneaded, and 1.9 parts of polyethylene wax was added to produce Preparation Example - Color 2.

[0058] [Table 5]

[0059] In the table, the following raw materials were used: Titanium oxide: Teika "TITANIX JR-808" Water-based urethane resin solution: Taisei Fine Chemical Co., Ltd. "Acrit WBR-016U" Water-based acrylic resin solution: BASF "JONCRYL PDX-7741" Polyethylene wax: Mitsui Chemicals "Chemipearl W-400"

[0060] <Preparation example-white 1> 28.0 parts of titanium oxide, 57.6 parts of a commercially available aqueous urethane resin solution with a solid content of 30% containing water, 4.2 parts of normal propyl alcohol, and 7.2 parts of water were mixed and kneaded, and 3.0 parts of polyethylene wax was added to produce Preparation Example - White 1.

[0061] <Preparation example-white 2> 28.0 parts of titanium oxide, 57.6 parts of a commercially available aqueous acrylic resin solution with a solid content of 30% containing water, 4.2 parts of normal propyl alcohol, and 7.2 parts of water were mixed and kneaded, and 3.0 parts of polyethylene wax was added to produce Preparation Example - White 2.

[0062] (Printing method) The oil-based anchor coat varnish described in Preparation Example was prepared with methylcyclohexane in a Zahn Cup #4 (manufactured by Rigo Co., Ltd.) for 10 seconds (25°C). The water-based anchor coat varnish and inks (water-based color inks, water-based white inks) described in the Preparation Examples were each prepared with water in a Zahn Cup #4 (manufactured by Rigo Co., Ltd.) for 10 seconds (25°C). Using a Windmill CI-type 6-color flexographic printing machine SOLOFLEX, various water-based or oil-based anchor coat varnishes or water-based inks were printed onto a biaxially oriented polypropylene film (thickness 15 μm) substrate to obtain laminates (printing ink laminates) with the configurations shown in Table 6 below. The printing order of the anchor coat varnish and ink was as shown in Table 6, with the anchor coat layer (first printed layer), color ink layer (second printed layer), and white ink layer (third printed layer) printed in that order.

[0063] The laminates (printing ink laminates) prepared in Table 6 were subjected to the following evaluations.

[0064] (Evaluation of laminate) [Adhesion before shrinkage] After printing the anchor coat layer and the ink layer, cellophane tape (manufactured by Nichiban Co., Ltd.) was applied to the printed surface, and then the tape was quickly peeled off, and the condition of the printed surface was evaluated visually. -Evaluation criteria- 3 The printed film does not peel off from the film at all 2 Less than 30% of the printed film surface area peels off from the film. 1 More than 70% of the printed film surface area peels off from the film.

[0065] [Scratch resistance before shrinkage] The ink layer surface of the resulting laminate (printed material) was rubbed back and forth with a fingernail 20 times, and the state of removal of the film from the printed surface was visually evaluated. -Evaluation criteria- 3 The printed film does not peel off from the film substrate at all. 2 Less than 30% of the printed film surface area peels off from the film substrate. 1 70% or more of the printed film surface area peels off from the film substrate.

[0066] [Crush resistance before shrinkage] The ink layer surfaces of the resulting laminate (printed matter) were rubbed back and forth five times, and the state of removal of the film from the printed surface was visually evaluated. -Evaluation criteria- 3 The printed film does not peel off from the film substrate at all. 2 Less than 30% of the printed film surface area peels off from the film substrate. 1 70% or more of the printed film surface area peels off from the film substrate.

[0067] [Adhesion after shrinkage] The resulting laminate (printed material) was shrunk in a thermostatic oven at 120° C. for 30 seconds. Next, cellophane tape (manufactured by Nichiban Co., Ltd.) was applied to the printed surface, and the tape was quickly peeled off, and the condition of the printed surface was visually evaluated. -Evaluation criteria- 3 The printed film does not peel off from the film substrate at all. 2 Less than 30% of the printed film surface area peels off from the film substrate. 1 70% or more of the printed film surface area peels off from the film substrate.

[0068] [Blocking resistance] The ink layer surface of the prepared laminate (printed material) was placed against the film substrate, and left for one day in a blocking tester under conditions of pressure: 0.5 MPa, temperature: 40°C, and humidity: 80%. After the test, the peeling properties and condition of the surface were evaluated. -Evaluation criteria- 4 When peeling the printed surfaces apart, there is no resistance and there are no particular problems with the surface. 3 When peeling the printed surfaces apart, there is some resistance and the surfaces are slightly stuck together. 2 When peeling the printed surfaces apart, there is resistance, but the ink layer does not peel off. 1 When peeling the printed surfaces apart, there is considerable resistance and the ink layer is peeling off.

[0069] [Heat resistance] The ink layer surface of the prepared laminate (printed material) is placed against a polystyrene sheet that represents the container in which the printed surface will be accumulated, and the sheets are pressed together with a heat seal bar at a pressure of 0.1 MPa for 1 second, and the extent to which the film on the printed surface has been removed is checked. Test temperature: 120℃ -Evaluation criteria- 4. The printed film does not come off at all on the polystyrene sheet. 3. The printed film is less than 30% of the surface area of ​​the polystyrene sheet. 2. The printed film covers less than 50% of the surface area of ​​the polystyrene sheet. 1. The printed film covers 70% or more of the surface area of ​​the polystyrene sheet.

[0070] (Examples 1 to 2, Reference Examples 1 to 4) The evaluation results for the laminates (printed materials) of the Examples and Reference Examples shown in Table 6 below are also shown in Table 6.

[0071] [Table 6]

[0072] The results of Examples 1 and 2 and Reference Examples 1 and 2 demonstrated that a laminate (printed material) having an anchor coat layer formed using the aqueous anchor coat layer-forming composition of the present invention has performance equivalent to that of a laminate (printed material) having an anchor coat layer formed using an oil-based anchor coat layer-forming composition (a laminate having excellent properties such as scratch resistance, crumple resistance, blocking resistance, and heat resistance while maintaining the adhesion of a laminate film), and that a laminate having equivalent performance can be formed using an aqueous anchor coat layer. Furthermore, a rating of 2 or higher in Table 6 indicates that the laminate is suitable for practical use. In this regard, Reference Examples 3 and 4, in which the binder resin in the anchor coat layer-forming composition was not a chlorinated polyolefin resin (more specifically, a chlorinated polypropylene resin) but a urethane resin or an acrylic resin, failed to achieve the intended effect of the present invention.

Claims

1. An anchor coat layer-forming composition for forming an anchor coat layer disposed between a heat-shrinkable film and an ink layer, Contains a binder resin and water, The composition for forming an anchor coat layer, wherein the binder resin contains a chlorinated polyolefin resin.

2. 2. The anchor coat layer forming composition according to claim 1, wherein the binder resin further contains at least one resin selected from the group consisting of polyurethane resin, acrylic resin, styrene-maleic anhydride resin, and rosin resin.

3. The composition for forming an anchor coat layer according to claim 1 , further comprising at least one of wax and silica.

4. A laminate comprising a heat-shrinkable film, an anchor coat layer, and an ink layer laminated in this order, A laminate, wherein the anchor coat layer is a layer formed using the composition for forming an anchor coat layer according to any one of claims 1 to 3.

5. The laminate according to claim 4 , wherein the heat shrinkable film is a polyolefin film.

6. The laminate according to claim 4 , wherein the ink layer is a layer formed using a water-based ink composition.

7. The laminate according to claim 6 , wherein the ink layer contains at least one resin selected from the group consisting of a urethane resin and an acrylic resin.

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