Laminate

Abstract

To provide a laminate having excellent adhesion, density, leveling properties, and heat sealability.SOLUTION: A laminate includes, in this order, a paper substrate including a size agent, a printed layer, and a surface protective layer. The laminate is characterized in that the printed layer includes a binder resin, a surfactant, and a coloring agent; the binder resin includes an acrylic resin (A) and / or a urethane resin (B); and the content of the surfactant is 0.05-20 mass% based on 100 mass% of the printed layer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a laminate. [Background technology]

[0002] In recent years, it has become common for product packaging and other wrapping materials to be printed for decoration and surface protection. Furthermore, the quality of the printing, including its design, aesthetic appeal, and sense of luxury, can stimulate consumer purchasing intent, and therefore has significant industrial value.

[0003] Traditionally, laminate packaging materials using plastic film have been primarily used for packaging. For example, Patent Document 1 describes an invention relating to a laminate packaging material consisting of a base material, a printing layer, an adhesive layer, and a sealant layer, in which biomass resin is used in the printing layer and the adhesive layer. However, laminate packaging materials use a large amount of plastic film made from petroleum-derived materials, and from the viewpoint of reducing plastic waste, environmental responsibility, and carbon neutrality, there is a desire to switch to paper (paper-based packaging materials), and technological development is underway.

[0004] Patent Document 2 describes a laminate having acid-resistant paper, an ink layer, and a polyethylene layer in that order, but there is no mention of the ink layer containing a surfactant, raising concerns about the low smoothness of the ink layer. Patent Document 3 describes a laminate having a paper substrate, a barrier layer, and a heat seal layer in that order, but there is no mention of the amount of surfactant added to each of the layers, and since the heat seal layer does not contain polyethylene resin, there are concerns about low leveling and heat sealability. Patent Document 4 describes a laminate having a paper substrate, a protective layer, and a heat seal layer, but the protective layer is not specified as being made of urethane resin, and furthermore, there is no mention of the amount of surfactant added, so there is no mention of adhesion, concentration, leveling, and heat seal strength. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-051796 [Patent Document 2] Japanese Patent Publication No. 2013-213111 [Patent Document 3] Japanese Patent Publication No. 2021-138434 [Patent Document 4] International Publication No. 2021 / 106926 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention aims to provide a laminate with excellent adhesion, density, leveling properties, and heat sealability. [Means for solving the problem]

[0007] As a result of diligent research into the aforementioned problems, the inventors have found that the above problems can be solved by using the laminate described below, and have thus come to the present invention. [Effects of the Invention]

[0008] The present invention makes it possible to provide a laminate with excellent adhesion, density, leveling properties, and heat sealability.

[0009] In other words, the present invention relates to a laminate having a paper substrate containing a sizing agent, a printed layer, and a surface protective layer in that order, The printed layer comprises a binder resin, a surfactant, and a colorant. The binder resin comprises acrylic resin (A) and / or urethane resin (B), The present invention relates to a laminate in which the content of the surfactant is 0.05 to 20% by mass of the printed layer at 100% by mass.

[0010] That is, the present invention relates to the laminate, wherein the surfactant contains at least one selected from the group consisting of an acetylene-based compound, an alcohol alkoxylate-based surfactant, a silicon-based surfactant, an acrylic-based surfactant, and a fluorine-based surfactant.

[0011] That is, the present invention relates to the laminate, wherein the total solid content of the acrylic resin (A) and the urethane resin (B) is 75% by mass or more in 100% by mass of the solid content of the binder resin.

[0012] That is, the present invention relates to the laminate, wherein the weight average molecular weight of the acrylic resin (A) is 25,000 or more.

[0013] That is, the present invention relates to the laminate, wherein the urethane resin (B) contains at least one selected from the group consisting of a structure derived from polyester polyol, a structure derived from polyether polyol, and a structure derived from polycarbonate polyol.

[0014] That is, the present invention relates to the laminate, wherein the printing layer further contains a hydrocarbon-based wax.

[0015] That is, the present invention relates to the laminate, wherein the solid content mass ratio of the surfactant and the binder resin in the printing layer is 1:99 to 50:50.

[0016] That is, the present invention relates to the laminate, wherein the solid content mass ratio of the surfactant and the colorant in the printing layer is 1:99 to 40:60.

[0017] That is, the present invention relates to the laminate, wherein the sizing agent is at least one selected from the group consisting of a rosin resin, an alkenyl succinate, an alkyl ketene dimer, a polyvinyl alcohol resin, and a starch resin.

[0018] That is, the present invention relates to the laminate, wherein the surface protection layer contains at least one selected from the group consisting of a polyolefin resin, a cellulose resin, an acrylic resin (A'), and a urethane resin (B').

[0019] That is, the present invention relates to the laminate, wherein the mass ratio of the sizing agent content in the paper base material per unit area to the surfactant content in the printing layer per unit area is 0.1:99.9 to 50:50.

[0020] That is, the present invention relates to the laminate, which is for a packaging container.

[0021] That is, the present invention is a method for manufacturing a laminate having a paper base material containing a sizing agent, a printing layer, and a surface protection layer in this order, including a step of printing a printing ink containing a binder resin, a surfactant, and a colorant on the paper base material to form the printing layer, wherein the binder resin contains an acrylic resin (A) and / or a urethane resin (B), and the surfactant is 0.05 to 20% by mass in 100% by mass of the printing layer, and relates to a method for manufacturing a laminate.

[0022] That is, the present invention relates to the method for manufacturing the laminate, wherein the printing ink further contains a solvent, and the solvent contains an alcohol solvent at 1 to 70% by mass in all the solvents of the printing ink.

Embodiments for Carrying Out the Invention

[0023] The embodiments of the present invention will be described in detail below. However, the description of the embodiments or requirements described below is an example of the embodiments of the present invention, and the present invention is not limited to these contents unless it exceeds the gist thereof.

[0024] <Laminate> A laminate comprising a paper substrate containing a sizing agent, a printing layer, and a surface protective layer in this order, wherein the printing layer comprises a binder resin, a surfactant, and a colorant, the binder resin comprises an acrylic resin (A) and / or a urethane resin (B), and the surfactant content is 0.05 to 20% by mass of 100% by mass of the printing layer. Furthermore, the laminate of the present invention may also have other layers, such as a barrier layer or a heat seal layer. The use of the laminate is not particularly limited, but it is preferably for packaging materials, and more preferably for packaging containers formed from the laminate into a container shape.

[0025] When forming a printed layer on a substrate, the coloring pigments contained in the ink used to form the printed layer remain largely on the surface of the paper substrate, while the binder resin penetrates into the interior of the paper substrate. As a result, the pigment concentration becomes high on the surface of the printed layer, and the strength of the printed layer tends to decrease. Therefore, by using a paper substrate containing acrylic resin (A) and / or urethane resin (B), as well as a surfactant and a sizing agent in the ink, it is possible to suppress excessive ink penetration into the paper substrate and improve the adhesion between the paper substrate and the printed layer, thereby achieving excellent adhesion, density, leveling properties, and heat sealability.

[0026] The following are preferred examples of the laminated structure of the laminate in the present invention, but they do not limit the present invention in any way. In the following examples, " / " represents the boundary of each layer. Paper base material / printing layer / surface protection layer Paper substrate / Printing layer / Anchor layer / Surface protective layer Barrier layer / Paper substrate / Printing layer / Surface protection layer Barrier layer / Paper substrate / Printing layer / Anchor layer / Surface protection layer Heat seal layer / Paper substrate / Printing layer / Surface protection layer Heat seal layer / Paper substrate / Printing layer / Anchor layer / Surface protection layer Heat seal layer / Barrier layer / Paper substrate / Printing layer / Surface protection layer Heat seal layer / Barrier layer / Paper substrate / Printing layer / Anchor layer / Surface protection layer

[0027] <Paper substrate containing sizing agent> The paper substrate containing the sizing agent used in the present invention only needs to contain the sizing agent in the paper substrate, and the manufacturing method is not limited. For example, it can be obtained by bonding a mixture of plant fibers and the sizing agent described below to papermaking using the method described in Japanese Patent Application Publication No. 2021-075827, or by applying a coating agent containing the sizing agent to the paper substrate and removing the volatile components. In 100% by mass of a paper substrate containing a sizing agent, the sizing agent content is preferably 0.01 to 5% by mass, more preferably 0.05 to 2% by mass, and even more preferably 0.1 to 1% by mass. When the content is within the above range, adhesion, concentration, leveling properties, and heat sealability tend to improve. The mass ratio of the sizing agent content in the paper substrate per unit area to the surfactant content in the printed layer per unit area is preferably 0.1:99.9 to 50:50, more preferably 1:99 to 30:70, even more preferably 5:95 to 20:80, and particularly preferably 7:93 to 15:85. When the ratio is within the above range, adhesion, concentration, leveling properties, and heat sealability tend to improve. The mass ratio of the sizing agent content in the paper substrate per unit area to the acrylic resin (A) and urethane resin (B) content in the printed layer per unit area is preferably 0.1:99.9 to 30:70, more preferably 0.2:99.8 to 10:90, and even more preferably 0.3:99.7 to 5:95. When the ratio is within the above range, adhesion, density, leveling properties, and heat sealability tend to improve.

[0028] <Sizing agent> The sizing agents used in the present invention can include, for example, rosin resins, alkenyl succinates, alkyl ketene dimers, styrene-acrylic copolymer resins, styrene-maleic acid copolymer resins, maleic acid resins, polyvinyl alcohol resins, starch resins, casein resins, vinyl acetate resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymer resins, urethane resins, acrylic resins, epoxy resins, polysaccharide esters, styrene elastomer resins such as styrene-butadiene copolymer resins, etc. One of the above sizing agents may be used alone, or two or more may be used in any proportion. In particular, it is preferable that at least one is selected from the group consisting of rosin resins, alkenyl succinates, alkyl ketene dimers, polyvinyl alcohol resins, and starch resins, more preferably at least one is selected from the group consisting of rosin resins, alkenyl succinates, and alkyl ketene dimers, and even more preferably an alkyl ketene dimer. When the above compounds are used, adhesion, concentration, and leveling properties tend to improve.

[0029] <Coating agent containing sizing agent> The coating agent used in the present invention, which contains a sizing agent, contains a sizing agent and a solvent, and is preferably water-based from the viewpoint of environmental impact. A known method can be used for applying a coating agent containing a sizing agent. For example, the coating can be applied using a sizing press machine such as a vertical two-roll sizing press coater, a horizontal two-roll sizing press coater, an inclined two-roll sizing press coater, a gate roll coater, or a rod metering sizing press.

[0030] <Additives other than sizing agents> The paper substrate containing a sizing agent used in the present invention may contain additives other than the sizing agent. For example, known additives such as yield enhancers such as aluminum sulfate and polyacrylamide, paper strength enhancers such as urea formaldehyde resin and melamine formaldehyde resin, and fillers such as talc and kaolin can be used.

[0031] <Print layer> The printing layer of the present invention comprises a binder resin, a surfactant, and a colorant. The printing layer is formed by printing a printing ink (hereinafter also referred to as aqueous ink when the solvent is an aqueous solvent), and either an oil-based ink or an aqueous ink can be used, but from the viewpoint of adhesion, leveling properties, and concentration, it is preferable to use an aqueous ink. The printing layer is located between the paper substrate and the surface protective layer, and the printing layer can be formed, for example, by printing aqueous ink onto the paper substrate using a gravure printing machine, and the coating amount of the printing layer is 0.1 to 4 g / m². 2 Preferably, it is 1-3 g / m 2 It is preferable that it be so.

[0032] <Binder resin> The binder resin used in the present invention includes an acrylic resin (A) and / or a urethane resin (B). Furthermore, the binder resin may also contain resins other than acrylic resin and urethane resin, such as polylactic acid resin, rosin-based resin, vinyl acetate resin, vinyl acetate copolymer resin, and styrene-maleic acid copolymer resin. These resins can be used individually or in mixtures of two or more. The binder resin content in the printed layer is preferably 40 to 90% by mass, and more preferably 60 to 80% by mass, of 100% by mass of the printed layer. When the content is within this range, adhesion, density, leveling properties, and heat sealability tend to improve. The solid content of the acrylic resin (A) and urethane resin (B) in the printed layer is preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 90% to 100% by mass, based on 100% by mass of the binder resin. When the content is within the above range, adhesion, density, leveling properties, and heat sealability tend to improve. The solid content of the acrylic resin (A) and urethane resin (B) in the printed layer is preferably 40 to 90% by mass, and more preferably 60 to 80% by mass, based on 100% by mass of the printed layer. The solid content of the acrylic resin (A) in the printed layer is preferably 40 to 90% by mass, and more preferably 60 to 80% by mass, based on 100% by mass of the printed layer. The solid content of the urethane resin (B) in the printed layer is preferably 40 to 90% by mass, and more preferably 60 to 80% by mass, based on 100% by mass of the printed layer. When the content is within the above ranges, adhesion, density, leveling properties, and heat sealability tend to improve.

[0033] <Acrylic resin (A)> The acrylic resin used in the present invention preferably contains an aqueous acrylic resin emulsion (a-1) and / or a water-soluble acrylic resin (a-2), and more preferably contains both an aqueous acrylic resin emulsion (a-1) and a water-soluble acrylic resin (a-2). The acid value of acrylic resin (A) is preferably 5 to 200 mg KOH / g, more preferably 20 to 100 mg KOH / g, and even more preferably 30 to 80 mg KOH / g. When the acid value is 5 mg KOH / g or higher, adhesion and heat sealability tend to be good, and when the acid value is 200 mg KOH / g or lower, concentration and leveling tend to be good. The glass transition temperature of acrylic resin (A) is preferably -20 to 130°C, and more preferably 0 to 50°C. When it is within the above range, adhesion, leveling, and heat sealability are improved. The weight-average molecular weight of acrylic resin (A) is preferably 25,000 to 600,000. When it is within the above range, adhesion, leveling, and heat sealability tend to be improved. Furthermore, when the acrylic resin (A) has multiple components, the acid value, glass transition temperature, and weight-average molecular weight were calculated using the following formula. (Formula 1) Acid value [mgKOH / g] when n types of acrylic resin (A1~An) are included. JPEG0007831504000001.jpg39130 (Equation 2) Glass transition temperature [°C] when n types of acrylic resin (A1~An) are included. JPEG0007831504000002.jpg36170 (Equation 3) Weight-average molecular weight when n types of acrylic resin (An) are included JPEG0007831504000003.jpg34170

[0034] <Water-based acrylic resin emulsion (a-1)> The acid value of the aqueous acrylic resin emulsion (a-1) is preferably 5 to 80 mg KOH / g, and more preferably 20 to 60 mg KOH / g. When it is within the above range, adhesion, concentration, and heat sealability tend to improve. The glass transition temperature of the aqueous acrylic resin emulsion (a-1) is preferably -20 to 60°C, and more preferably 0 to 40°C. When it is within the above range, adhesion, leveling, and heat sealability tend to improve. The weight-average molecular weight of the aqueous acrylic resin emulsion (a-1) is preferably 10,000 to 600,000, more preferably 50,000 to 500,000, even more preferably 100,000 to 400,000, and particularly preferably 200,000 to 300,000. When it is within the above range, adhesion, leveling, and heat sealability tend to improve. The emulsion particle size of the aqueous acrylic resin emulsion (a-1) is preferably 10 to 300 nm, and more preferably 60 to 100 nm. When the particle size is within this range, the concentration, leveling properties, and heat sealability tend to improve.

[0035] The aqueous acrylic resin emulsion (a-1) is a polymer or copolymer obtained by polymerizing monomer components mainly composed of (meth)acrylic acid and / or (meth)acrylate, and may hereafter be referred to as aqueous (meth)acrylic resin. Furthermore, it is preferably a styrene-acrylic copolymer resin. Here, "(meth)acrylic acid" refers to the combined use of "acrylic acid" and "methacrylic acid." "(meth)acrylate" refers to the combined use of "acrylate" and "methacrylate."

[0036] Examples of the above (meth)acrylates include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, behenyl acrylate, trimethylcyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; aromatic (meth)acrylates such as phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxydiethylene glycol (meth)acrylate; Heterocyclic (meth)acrylates such as tetrahydrofurfree (meth)acrylate and oxetane (meth)acrylate; alkoxypolyalkylene glycol (meth)acrylates such as methoxypolypropylene glycol (meth)acrylate and ethoxypolyethylene glycol (meth)acrylate; Examples include N-substituted (meth)acrylamides such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, diacetone(meth)acrylamide, and acryloylmorpholine; amino group-containing (meth)acrylates such as N,N-dimethylaminoethyl(meth)acrylate and N,N-diethylaminoethyl(meth)acrylate; and nitriles such as (meth)acrylonitrile.

[0037] In one embodiment, the monomer components constituting the aqueous (meth)acrylic resin may further include ethylenically unsaturated monomers other than (meth)acrylic acid and / or (meth)acrylate. Examples of ethylenically unsaturated monomers include styrene monomers such as styrene and α-methylstyrene, vinyl monomers such as vinyl acetate and vinyl chloride, and carboxyl group-containing ethylenically unsaturated monomers such as itaconic acid, maleic acid, fumaric acid, and crotonic acid. Among these, it is preferable to use styrene monomers because they make it easy to obtain excellent gloss.

[0038] In one embodiment, the aqueous (meth)acrylic resin may be a copolymer of (meth)acrylic acid and / or (meth)acrylate and a styrene monomer. More specifically, the aqueous (meth)acrylic resin may be a copolymer obtained by copolymerization of (meth)acrylic acid, (meth)acrylate and styrene.

[0039] While not particularly limited, specific examples of monomer combinations constituting aqueous (meth)acrylic resins include acrylic acid / styrene / n-butyl methacrylate / 2-ethylhexyl acrylate, acrylic acid / methyl methacrylate / 1,4-cyclohexanedimethanol monoacrylate / n-butyl methacrylate / 2-ethylhexyl acrylate, acrylic acid / styrene / n-butyl methacrylate, methacrylate / methyl methacrylate / styrene, acrylic acid / styrene / n-butyl methacrylate / 2-ethylhexyl acrylate, and the like.

[0040] Emulsion resins can be prepared according to methods known in the art. For example, emulsion resins can be prepared by emulsion polymerization under conditions in which monomer components are emulsified into micelles and dispersed in water. For example, emulsion polymerization can be carried out in the presence of ammonium persulfate and sodium metabisulfite. After emulsion polymerization, the acid value of the resin can be adjusted as needed by adding a basic compound such as aqueous ammonia.

[0041] In one embodiment, the aqueous (meth)acrylic resin may be neutralized to improve its solubility or dispersibility in aqueous solvents. For example, after introducing acidic groups such as carboxyl groups during resin synthesis, some or all of them can be neutralized to increase hydrophilicity. Neutralization of carboxyl groups can be carried out using amines such as triethylamine or other basic compounds.

[0042] The water-based acrylic resin emulsion (a-1) may be a commercially available product; for example, HE-1335, X-436, QE-1042, etc., manufactured by Seikoh PMC can be used.

[0043] <Water-soluble acrylic resin (a-2)> The acid value of the water-soluble acrylic resin (a-2) is preferably 200 mg KOH / g or less, more preferably 20 to 150 mg KOH / g, and even more preferably 40 to 100 mg KOH / g. When it is within the above range, adhesion, concentration, and heat sealability tend to improve. The glass transition temperature of the water-soluble acrylic resin (a-2) is preferably 40 to 130°C, and more preferably 60 to 120°C. When it is within the above range, adhesion, leveling, and heat sealability tend to improve. The neutralizing agent for the water-soluble acrylic resin (a-2) is preferably ammonia, organic amine, alkali metal hydroxide, etc., and more preferably ammonia. When the above neutralizing agent is used, concentration and leveling tend to improve. The weight-average molecular weight of the water-soluble acrylic resin (a-2) is preferably 1500 to 50000, more preferably 1500 to 30000, and even more preferably 1500 to 8000. Within the above range, adhesion, leveling, and heat sealability tend to improve.

[0044] The monomers constituting the water-soluble acrylic resin (a-2) can be the same as those described in <Acrylic Resin (A)> for <Aqueous Acrylic Resin Emulsion (a-1)>.

[0045] The water-soluble acrylic resin (a-2) used in the present invention may be a commercially available product, such as BASF's "Joncryl 67, Joncryl 678, Joncryl 680, Joncryl 819".

[0046] The solid content ratio of the aqueous acrylic resin emulsion (a-1) and the water-soluble acrylic resin (a-2) is preferably 95:5 to 60:40, and more preferably 90:10 to 80:20. When the ratio is within this range, adhesion, leveling, and heat sealability tend to improve.

[0047] <Urethane resin (B)> The urethane resin used in the present invention is preferably an aqueous urethane resin, and is obtained by reacting a urethane prepolymer having isocyanate groups at its ends, which is formed by reacting a polyisocyanate (b-1), a polymer polyol (b-2), and a compound (b-3) having a carboxyl group and at least two active hydrogen-containing groups in the molecule, with an organic diamine (b-4). The acid value of the aqueous urethane resin used in this invention is preferably 25 to 65 mgKOH / g, and more preferably 25 to 45 mgKOH / g. When it is within this range, adhesion, concentration, leveling properties, and heat sealability are improved. The weight-average molecular weight of the aqueous urethane resin is preferably 5,000 to 100,000, more preferably 10,000 to 70,000, and even more preferably 20,000 to 40,000. When it is within this range, adhesion, leveling properties, and heat sealability are improved. The glass transition temperature of the aqueous urethane resin is preferably -20 to 60°C, and more preferably 0 to 40°C. When it is within this range, adhesion, leveling properties, and heat sealability tend to improve.

[0048] As the polyisocyanate (b-1) used in the aqueous urethane resin of the present invention, various known aromatic, aliphatic, or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzylu isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropyl diisocyanate, methylene diisocyanate, 2,2,4-tri 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(isocyanate-methyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimer isocyanates obtained by converting the carboxyl groups of dimer acids to isocyanate groups. These can be used individually or in combination of two or more. Isophorone diisocyanate is preferred in terms of reactivity and other factors.

[0049] The number-average molecular weight of the polymer polyol (b-1) used in the aqueous urethane resin of the present invention is preferably 3000 or less, that is, the number-average molecular weight of each polymer polyol (b-1) used is preferably 3000 or less. When it is within the above range, adhesion is improved. The number-average molecular weight is calculated from the hydroxyl value, which is the value obtained by esterifying or acetylating the hydroxyl groups in the resin, back titrating the remaining acid with an alkali, and converting the amount of hydroxyl groups in 1 g of resin to the number of mg of potassium hydroxide, in accordance with JIS K0070.

[0050] Examples of the polymer polyol (b-1) include polyester polyol, polyether polyol, polycaprolactone diol, polycarbonate polyol, polyolefin polyol, castor oil polyol, hydrogenated castor oil polyol, dimer diol, and hydrogenated dimer diol. Preferably, it is at least one selected from the group consisting of polyester polyol, polyether polyol, and polycarbonate polyol, more preferably polyester polyol and / or polyether polyol, and even more preferably polyester polyol. When the above polyol is used, adhesion, concentration, leveling properties, and heat sealability tend to improve.

[0051] (Polyester polyol) Polyester polyols are dehydration condensates or polymers of polycarboxylic acids or polycarboxylic acid anhydrides, such as 1,2-propanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,4-pentanediol, 3-methyl-1,5-pentanediol, 2,5-hexanediol, 2-methyl-1,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, and 2,2,4-trimethyl-1,6-hexanediol. Examples include 1,2-propanediol, 1,3-butanediol, and 2-methyl-1,3-propanediol. Examples include low molecular weight polyols having a branched structure, such as 1,4-pentanediol, 3-methyl-1,5-pentanediol, 2,5-hexanediol, 2-methyl-1,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, and 2,2,4-trimethyl-1,6-hexanediol, and dehydration condensates or polymers of polycarboxylic acids such as adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, superiic acid, azelaic acid, sebacic acid, trimellitic acid, and pyromellitic acid, or their anhydrides. These can be used individually or in combination of two or more. Polyester polyols preferably have a branched structure, and by using low-molecular-weight polyols having the above-mentioned branched structure, a branched structure can be introduced into the polyester polyol.

[0052] When polymer polyol (b-1) contains polyester polyol, the polyester polyol content is preferably 30 to 99% by mass, more preferably 50 to 97% by mass, and even more preferably 80 to 95% by mass, based on 100% by mass of polymer polyol. When the content is within the above range, adhesion, concentration, and leveling properties tend to improve.

[0053] (Polyether polyol) Suitable examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, and copolymers thereof. The polyether polyol preferably contains constituent units derived from polyethylene glycol, and more preferably contains 0.1 to 25% by mass, 2 to 15% by mass, and even more preferably 2 to 10% by mass, per 100% by mass of the polyether polyol.

[0054] (Polycarbonate polyol) The polycarbonate polyol is not limited by its manufacturing method or the type of diol it comprises, but a polycondensate product obtained by transesterification of a diol made of alkylene glycol with a carbonate compound is preferred. Furthermore, the polycarbonate polyol is preferably an alicyclic and / or aliphatic polycarbonate diol.

[0055] Suitable examples of the above-mentioned diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 1,10-decanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butynediol, 2,2,4-trimethyl-1,3-pentanediol, 1,4-cyclohexanedimethanol, diethylene glycol, polypropylene glycol, and dipropylene glycol, which can be used individually or in combination of two or more. 3-methyl-1,5-pentanediol and other polycarbonate polyols having a branched diol structure are preferred. The carbonate compound is not particularly limited, but examples include dialkyl carbonates, diaryl carbonates, or alkylene carbonates. Specific examples of carbonate compounds include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and dibutyl carbonate, diaryl carbonates such as diphenyl carbonate, and alkylene carbonates such as ethylene carbonate.

[0056] In the aqueous urethane resin of the present invention, the active hydrogen-containing group refers to a group having active hydrogen, such as a hydroxyl group or an amino group, that reacts with an isocyanate group.

[0057] Examples of compounds (b-3) used in the aqueous urethane resin of the present invention that have a carboxyl group and at least two active hydrogen-containing groups in their molecule include dimethylolalkanoates such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutyric acid, and 2,2-dimethylolvaleric acid; and diamine-type amino acids such as glutamine, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid, and diaminobenzenesulfonic acid. These can be used individually or in combination of two or more.

[0058] The organic diamine (b-4) used in the aqueous urethane resin of the present invention is an organic diamine having a hydroxyl group in an amount of 50% to 100% by weight. If the amount of organic diamine having a hydroxyl group is less than 50% by weight, the resolubility in water-alcohol is poor.

[0059] Examples of organic diamines having a hydroxyl group that can be used in the aqueous urethane resin of the present invention include 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine. These can be used individually or in combination of two or more.

[0060] Examples of organic diamines that do not have a hydroxyl group and can be used in the aqueous urethane resin of the present invention include ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, and various other known dimeramines obtained by converting the carboxyl group of a dimer acid to an amino group. These can be used individually or in combination of two or more.

[0061] The aqueous urethane resin used in this invention can be obtained by methods such as the acetone method, which uses an organic solvent that is inert to isocyanate and hydrophilic, or by a solvent-free synthesis method that does not use any solvent. In this invention, the acetone method was used, which uses an organic solvent to reduce viscosity and allow the synthesis reaction to proceed uniformly and smoothly.

[0062] To obtain a urethane prepolymer having isocyanate groups at its termini, obtained by reacting a polyisocyanate (b-1), a polymer polyol (b-2), and a compound (b-3) having a carboxyl group and at least two active hydrogen-containing groups in its molecule, it is preferable to carry out the reaction at 50-100°C for 10 minutes to 10 hours. The endpoint of the reaction is determined by viscosity measurement, NCO peak measurement by IR measurement, NCO% measurement by titration, etc.

[0063] Furthermore, catalysts can be used in the prepolymer reaction. Known metal catalysts and amine catalysts can be used. Examples of metal catalysts include dibutyltin dilaurate, tin octoate, dibutyltin di(2-ethylhexoate), lead 2-ethylhexoate, 2-ethylhexyl titanate, iron 2-ethylhexoate, cobalt 2-ethylhexoate, zinc naphthenate, cobalt naphthenate, and tetra-n-butyltin. Examples of amine catalysts include tertiary amines such as tetramethylbutanediamine. These catalysts are used in concentrations of 0.001 to 1 mol% relative to the polymer polyol.

[0064] When reacting a urethane prepolymer with an organic diamine (hereinafter referred to as the chain extension reaction), it is preferable to carry out the reaction at 30-80°C for 10 minutes to 10 hours. The endpoint of the reaction is determined by viscosity measurement, NCO peak measurement by IR measurement, amine value measurement by titration, etc.

[0065] A reaction stopper may be used in the chain extension reaction. Examples of reaction stoppers include dialkylamines such as di-n-butylamine, as well as amines having hydroxyl groups such as monoethanolamine, diethanolamine, 2-amino-2-methyl-1-propanol, tri(hydroxymethyl)aminomethane, and 2-amino-2-ethyl-1,3-propanediol. Furthermore, monoamine-type amino acids such as glycine, alanine, glutamic acid, taurine, aspartic acid, aminobutyric acid, valine, aminocaproic acid, aminobenzoic acid, aminoisophthalic acid, and sulfamic acid can also be used.

[0066] Basic compounds used to neutralize the carboxyl groups incorporated into the aqueous urethane resin in the present invention include ammonia, monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, methyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine, 2-amino-2-methyl-1-propanol, and other organic amines; and inorganic alkalis such as sodium hydroxide and potassium hydroxide. One or more of these can be used in combination, but from the viewpoint of water resistance of printed materials and residual odor, water-soluble and highly volatile compounds that dissociate easily with heat are preferred, and ammonia is particularly preferred.

[0067] Examples of organic solvents that are inert to isocyanates and hydrophilic include ethers such as tetrahydrofuran and dioxane, esters such as ethyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, and amides such as dimethylformamide and N-methylpyrrolidone. However, since the aqueous nature of polyurethane is usually removed by vacuum distillation (solvent removal), and even when used without solvent removal, it is preferable to use a solvent with a lower boiling point than water to speed up the drying rate. When solvent removal is performed, for example, by adding water and a basic compound as a neutralizing agent to the reaction solution, and then raising the temperature and distilling off the required amount of solvent under normal pressure or reduced pressure. The aqueous urethane resin may be in the form of an emulsion resin or a water-soluble resin.

[0068] <Coloring agent> The printed layer contains a colorant. The content of the colorant is preferably 1 to 60% by mass, and more preferably 30 to 50% by mass, of the total mass of the printed layer. A pigment is preferred as the colorant, and either an organic pigment or an inorganic pigment can be used.

[0069] (Organic pigments) Specific examples of organic pigments are shown using their CI numbers from the Colour Index International (CI). Preferably, CI Pigment Red 57:1, CI Pigment Red 48:1, CI Pigment Red 48:2, CI Pigment Red 48:3, CI Pigment Red 146, CI Pigment Red 242, CI Pigment Yellow 83, CI Pigment Yellow 14, CI Pigment Orange 64, CI Pigment Orange 38, CI Pigment Orange 34, CI Pigment Orange 13, CI Pigment Yellow 180, CI Pigment Yellow 139, CI Pigment Red 185, CI Pigment Red 122, These are CI Pigment Red 178, CI Pigment Red 149, CI Pigment Red 144, CI Pigment Red 166, CI Pigment Violet 23, CI Pigment Violet 37, CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 15:4, CI Pigment Blue 15:6, CI Pigment Green 7, and CI Pigment Black 7. These may be used individually or in combination of two or more types.

[0070] (Inorganic pigments) Examples of inorganic pigments include titanium dioxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, aluminum hydroxide, silica, kaolin, clay, talc, aluminum particles, mica, bronze powder, chrome vermilion, lead yellow, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, iron black, titanium dioxide, and zinc oxide. Aluminum can be leafing or non-leafing, but the non-leafing type is preferred.

[0071] <Additives> The printed layer of the present invention may contain various additives as needed. Examples include dispersants, surfactants, waxes, leveling agents, defoaming agents, and film-forming aids. Specifically, various additives can be added, such as surfactants to adjust affinity with the base material, binder resin, colorants, etc.; dispersions of wax resin fine particles such as polyethylene wax to improve water friction resistance; inorganic fine particles, adhesive resins, and vinyl acetate resins to provide anti-slip properties; leveling agents to improve leveling properties; defoaming agents to provide anti-foaming properties; basic compounds such as sodium hydroxide and potassium hydroxide to provide resolubility; and glycol compounds to provide film-forming properties.

[0072] <Surfactants> While known surfactants can be used as the surfactant in the present invention, it is preferable that at least one is selected from the group consisting of acetylene-based surfactants, silicone-based surfactants, acrylic-based surfactants, fluorine-based surfactants, and alcohol alkoxylate-based surfactants, more preferably at least one is selected from the group consisting of acetylene-based surfactants, acrylic-based surfactants, and alcohol alkoxylate-based surfactants, and even more preferably an acetylene-based surfactant. When the above compounds are used, adhesion, concentration, leveling properties, and heat sealability tend to improve. The HLB value of the surfactant is preferably in the range of 1 to 17, more preferably in the range of 3 to 10, and even more preferably in the range of 4 to 8. When the value is within the above range, leveling properties and alcohol resistance tend to improve.

[0073] The solid content of the surfactant in the printed layer is preferably 0.05 to 20% by mass, more preferably 0.1 to 10% by mass, even more preferably 0.5 to 7% by mass, and particularly preferably 1 to 5% by mass, based on 100% by mass of the printed layer. When the content is within the above range, adhesion, concentration, leveling properties, and heat sealability are improved. The solid content mass ratio of surfactant to binder resin in the printed layer is preferably 1:99 to 50:50, more preferably 10:90 to 30:70, and even more preferably 20:80 to 40:60. When the ratio is within the above range, adhesion, concentration, leveling properties, and heat sealability tend to improve. The solid content mass ratio of surfactant to colorant in the printed layer is preferably 1:99 to 40:60, more preferably 3:97 to 30:70, and even more preferably 5:95 to 20:80. When the ratio is within the above range, adhesion, concentration, leveling properties, and heat sealability tend to improve.

[0074] <Acetylene-based surfactants> Acetylene-based surfactants are nonionic compounds having an acetylene group. It is even more preferable that the acetylene-based surfactant is an ethylene oxide adduct. Examples of commercially available acetylene glycol compounds include Olphine E1010 and Olphine E1020 from Nisshin Chemical Industry Co., Ltd., and Surfinol 104, Surfinol 420, Surfinol 440, Surfinol 465, and Surfinol 485 from Air Products and Chemicals Inc.

[0075] Examples of commercially available silicone-based surfactants include BYK-3480 and BYK-3481 from BYK Corporation; examples of commercially available acrylic-based surfactants include BYK-381 and BYK-3441 from BYK Corporation; examples of commercially available fluorine-based surfactants include Megafac F-552 and Megafac F-572 from DIC Corporation; and examples of commercially available alcohol alkoxylate-based surfactants include DYNWET800 from BYK Corporation.

[0076] <wax> The printed layer preferably contains wax. Examples of waxes include amide waxes and hydrocarbon waxes, with hydrocarbon wax being more preferable. Furthermore, the hydrocarbon wax is preferably polyethylene wax. The average particle size of the hydrocarbon wax is preferably 1.5 to 10 μm, and more preferably 2 to 5 μm. Within this range, adhesion and heat sealability are improved. The hardness (penetration) of the hydrocarbon wax at 25°C as specified in JIS K2207 is preferably 15 or less, more preferably 7 or less, even more preferably 3 or less, particularly preferably 1 or less, and preferably 0.01 to 1. Within this range, adhesion and heat sealability are improved. The density of the hydrocarbon wax at 23°C as specified in JIS K7112 (Method B) is 880 to 990 kg / m³. 3 Preferably, it is 900-940 kg / m 3 It is more preferable that the temperature falls within the above range. When the temperature falls within the above range, adhesion and heat sealability are improved. The melting point of hydrocarbon waxes in DSC measurement is preferably 90 to 150°C, and more preferably 100 to 125°C. When the temperature falls within the above range, adhesion and heat sealability tend to improve. The melting point of hydrocarbon waxes represents the melting point of the peak top (minimum value) of the endothermic peak in the DSC heating curve.

[0077] The hydrocarbon wax content is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.2 to 0.3% by mass, based on 100% by mass of the total solids content of the printing ink. When the content is within the above range, adhesion and heat sealability tend to improve.

[0078] <Solvents contained in printing inks> The solvent contained in the printing ink is preferably water as the main component, but polar organic solvents can also be used in addition to water. Specifically, it is preferable to include alcohol solvents, etc., depending on the printing conditions (speed, plate depth, design, drying temperature). The solvent content in the printing ink is preferably 40 to 80% by mass. Furthermore, the alcohol solvent content is preferably 1 to 70% by mass, more preferably 10 to 50% by mass, and even more preferably 15 to 35% by mass, of the total solvent contained in the printing ink. When the content is within the above range, adhesion, density, and leveling tend to improve. In this invention, the main component being water means that water has the highest content in the solvent.

[0079] Examples of the alcohol solvents mentioned above include methanol, ethanol, propanol, isopropanol, isobutanol, n-butanol, tert-butanol, hexanol, octanol, decanol, etc. These may be used individually or in combination.

[0080] <Method of manufacturing printing ink> Printing inks can be manufactured, for example, by dispersing pigments in an aqueous medium using a disperser with a resin, and then mixing the resulting pigment dispersion with resin, various additives, and organic solvents. Commonly used dispersers such as roller mills, ball mills, pebble mills, attritors, and sand mills can be used. The particle size distribution of the pigment in the pigment dispersion can be adjusted by appropriately adjusting the size of the grinding media in the disperser, the filling rate of the grinding media, the dispersion processing time, the discharge speed of the pigment dispersion, and the viscosity of the pigment dispersion. The viscosity of the printing ink at 25°C is preferably in the range of 50 mPa·s or more from the viewpoint of preventing pigment sedimentation and ensuring adequate dispersion, and 300 mPa·s or less from the viewpoint of workability during ink manufacturing and printing.

[0081] <Method for forming the printed layer> The printed layer can be formed, for example, by printing on a paper substrate containing a sizing agent using a printing ink, and then removing the solvent. The printing ink can be diluted as needed with a diluent consisting of water or a water-soluble organic solvent during printing, and then printed on various substrates. A mixed solvent of water and an alcohol solvent is preferred as the diluent, and from the viewpoint of ink storage stability and drying, a mass ratio of 30:70 to 90:10 is preferable. The printing method can include gravure printing, flexographic printing, screen printing, or other printing methods, with gravure printing being preferred.

[0082] (Gravure printing) Gravure version In gravure printing, the gravure plate is a cylindrical metal plate into which recesses of each color are formed by engraving, etching, or laser. There are no restrictions on the use of engraving or laser, and the settings can be arbitrarily determined according to the design. Line screens of 80 to 250 lines per inch are used as appropriate, with higher line screens allowing for finer printing. The thickness of the printed layer is preferably 0.1 μm to 100 μm.

[0083] Gravure printing press In a gravure printing press, one printing unit is equipped with the gravure plate and doctor blade. Multiple printing units are available, and units can be configured to accommodate organic solvent-based printing inks and image inks. Each unit has an oven drying unit. Printing is performed by rotary press using a roll printing method. The type of plate and doctor blade are selected as appropriate, according to the specifications.

[0084] <Surface protective layer> The surface protective layer used in the present invention can be formed from known resins, such as styrene resin, maleic acid resin, urethane resin (B'), polylactic acid resin, polyvinylpyrrolidone resin, starch resin, cellulose resin, polyolefin resin, and acrylic resin (A'). It is preferable to include at least one selected from the group consisting of polyolefin resin, cellulose resin, acrylic resin (A'), and urethane resin (B'), and more preferably a polyolefin resin. When using the above resins, the method for forming the surface protective layer is not particularly limited, but it can be formed by coating with a heated and melted resin or by applying a coating agent in which the resin is dissolved and dispersed in a solvent. The above resins can be used individually, or two or more can be used in combination. The thickness of the surface protective layer is preferably 1 to 30 μm, and more preferably 5 to 15 μm. The resin content of the surface protective layer is preferably 80 to 100% by mass, and more preferably 90 to 100% by mass, of 100% by mass of the surface protective layer. Within the above range, heat sealability tends to be good.

[0085] (Polyolefin resin) The polyolefin resin included in the surface protective layer includes polyethylene resins and polypropylene resins, with polyethylene resins being preferred from the viewpoint of heat sealability. The polyethylene resin may be a homopolymer or copolymer of ethylene, or a copolymer with other monomers such as vinyl acetate, and may have ionic properties. In particular, it is preferable that it be at least one selected from the group consisting of polyethylene resin, ethylene-vinyl acetate copolymer resin, and ethylene-based ionomer resin, more preferably polyethylene resin and / or ethylene-vinyl acetate copolymer resin, and even more preferably polyethylene resin.

[0086] (Acrylic resin (A')) The acrylic resin (A') contained in the surface protective layer can be described using the same information as for <acrylic resin (A)> in the <printing layer> section.

[0087] (Urethane resin (B')) The urethane resin (B') contained in the surface protective layer can be described using the same information as for the urethane resin (B) described in the printing layer section.

[0088] (Cellulose resin) As a cellulose-based resin, cellulose ester resin is preferred. Cellulose ester resin is a resin obtained by esterifying cellulose derived from non-edible plants such as wood fibers and cotton, and examples include cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, and nitrocellulose. From the viewpoint of heat resistance, nitrocellulose is preferred as the cellulose ester resin.

[0089] The cellulose resin is preferably such that its viscosity, measured in accordance with JIS K 6703-1995, satisfies any of the following conditions (1) to (3). The viscosity is the time it takes for a steel ball to fall through the isopropanol solution of the cellulose resin (steel ball fall time (seconds)). (1) The viscosity at a solution concentration of 12.2% is 1.5 to 16 seconds. (2) The viscosity at a solution concentration of 20.0% is 3.0 to 40 seconds. (3) The viscosity at a solution concentration of 25.0% is 0.1 to 22 seconds. In particular, the viscosity of the cellulose resin is preferably such that it satisfies the above condition (3). In the above condition (3), the viscosity at a solution concentration of 25.0% is preferably 0.5 to 15 seconds, and more preferably 0.5 to 9 seconds.

[0090] The weight-average molecular weight (Mw) of the cellulose resin is preferably 5,000 to 200,000, more preferably 10,000 to 100,000, and even more preferably 10,000 to 80,000. Furthermore, the glass transition temperature of the cellulose resin is preferably 80°C to 160°C.

[0091] <Anchor layer> The laminate of the present invention may further have an anchor layer, which is located between the printed layer and the surface protective layer. The method for forming the anchor layer is not particularly limited, but it can be formed by printing an imine-based anchor coating agent, a butadiene-based anchor coating agent, an isocyanate-based anchor coating agent, etc., using a known printing method such as gravure printing. The coating amount of the anchor layer is 0.1 to 3 g / m². 2 It is preferable that this be the case.

[0092] <Heat seal layer> The laminate of the present invention may further have a heat-seal layer, which is located on the paper substrate opposite to the side having the printed layer. The method for forming the heat-seal layer is not particularly limited, but it can be formed by coating with a heated and melted resin or by applying a coating agent in which a resin is dissolved and dispersed in a solvent or the like. For example, a heat seal layer can be formed by printing on the paper substrate surface opposite the printed layer using a heat sealant, and then drying and removing the volatile components. Gravure printing and flexographic printing are preferred printing methods in this case. For example, in gravure printing, the heat seal layer can be obtained by diluting it with a suitable viscosity and concentration as needed, supplying it to each printing unit either alone or in a mixture, applying it, and fixing the film by drying it in an oven. In addition, a heat seal layer can also be formed by coating it with molten resin.

[0093] The heat seal layer preferably contains a polyolefin resin and / or an acrylic resin. The polyolefin resin may be a homopolymer or copolymer of ethylene, propylene, butadiene, hexene, etc., or a copolymer with other monomers such as vinyl acetate, and may be ionic. In particular, it is preferably at least one selected from the group consisting of ethylene-vinyl acetate copolymer resin, acrylic resin, and ethylene-based ionomer resin, and more preferably ethylene-vinyl acetate copolymer resin and / or ethylene-based ionomer resin. In addition to the above, the heat seal layer may also contain urethane resin, polyethylene resin, polypropylene resin, etc. These may be used individually or in combination of two or more. The thickness of the heat seal layer is 1 to 30 μm, and preferably 5 to 20 μm.

[0094] <Barrier layer> The laminate of the present invention may further have a barrier layer, and it is preferable that the barrier layer is located on the side of the paper substrate opposite to the printed layer. The method for forming the barrier layer is not particularly limited, and an inorganic compound layer can be formed on the paper substrate by known methods such as vacuum deposition or sputtering. Alternatively, the barrier layer can be applied to the paper substrate by using the vapor-deposited paper described above. The barrier layer preferably contains an inorganic compound such as aluminum, alumina, or silica. The purity of the inorganic compound is preferably 99% by mass or higher, and more preferably 99.9% by mass or higher. [Examples]

[0095] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to these examples. It is not fixed and various modifications are possible. Unless otherwise noted, the notation "%" represents parts by mass and mass %. Examples 53-55 are for reference only.

[0096] <Hydroxyl value> The hydroxyl value is the amount of potassium hydroxide (in mg) required to neutralize the acetic acid bonded to the hydroxyl group when 1 g of the sample is acetylated, and was measured by the method described in JIS K 0070.

[0097] <Acid value> The acid value is the number of milligrams of potassium hydroxide required to neutralize the free fatty acids, resin acids, etc., contained in 1 g of the sample, and was measured by the method described in JIS K 0070.

[0098] <Amine value> The amine value was determined by the amount of potassium hydroxide in milligrams equivalent to the amount of hydrochloric acid required to neutralize the amino groups contained in 1 g of the sample, and was measured in accordance with JIS K 0070. 0.5 to 2 g of the sample was accurately weighed (sample solids: S g), and 50 mL of a methanol / methyl ethyl ketone = 60 / 40 (mass ratio) mixed solution was added to the weighed sample to dissolve it. Bromophenol blue was added to the resulting solution as an indicator, and the solution was titrated with a 0.2 mol / L ethanolic hydrochloric acid solution (titer: f). The endpoint was defined as the point where the solution color changed from green to yellow, and the titration volume (A mL) at this point was used to determine the amine value using the following formula (Equation 4). (Formula 4) Amine value = (A × f × 0.2 × 56.108) / S [mgKOH / g]

[0099] <Mass average molecular weight> The mass-average molecular weight was determined by measuring the molecular weight distribution using a gel permeation chromatography (GPC) apparatus (HLC-8220, manufactured by Tosoh Corporation) and calculating the converted molecular weight using polystyrene as a standard substance. The measurement conditions are shown below. Columns: The following columns were used, connected in series. • TSKgel SuperAW2500 manufactured by Tosoh Corporation • TSKgel SuperAW3000 manufactured by Tosoh Corporation • TSKgel SuperAW4000 manufactured by Tosoh Corporation • TSK Gelguard Column Super AWH manufactured by Tosoh Corporation Detector: RI (Differential Refractometer) Measurement conditions: Column temperature 40°C Eluent: Tetrahydrofuran Flow rate: 1.0mL / min

[0100] <Glass transition temperature (Tg)> The glass transition temperature was determined by differential scanning calorimetry (DSC). The measurement was performed using a Rigaku Corporation DSC8231 under the conditions of a measurement temperature range of -70 to 250°C and a heating rate of 10°C / min. The midpoint (inflection point) of the baseline shift based on the glass transition in the DSC curve was defined as the glass transition temperature.

[0101] <Measuring the thickness of the printed layer> Five 10cm square pieces were cut from a sample with a printed layer formed on a paper substrate, and five 10cm square pieces were also cut from a sample of paper substrate alone. The mass of each sample was measured, and the mass per unit area of ​​the printed layer was calculated using the following formula (Equation 5). Paper substrate K1 containing a sizing agent, as described later, was used as the paper substrate. (Formula 5) Mass per unit area of ​​the printed layer [g / m²] 2 ] = (Average mass of 5 samples of paper substrate / printed layer) - (Average mass of 5 samples of paper substrate)

[0102] <Synthesis Example 1> Synthesis of aqueous urethane resin PU1 solution In a reactor equipped with a thermometer, stirrer, reflux condenser, and nitrogen gas inlet, 178.2 parts of poly(3-methyl-1,5-pentaneadipate)diol with a number average molecular weight of 2000, 18.2 parts of polyethylene glycol with a number average molecular weight of 2000, 33.4 parts of dimethylolbutanoic acid, and 116.5 parts of isophorone diisocyanate were reacted in 200 parts of methyl ethyl ketone for 6 hours while introducing nitrogen gas to obtain a terminal isocyanate prepolymer. After cooling to 40°C, 100 parts of acetone were added to obtain a solvent solution of the terminal isocyanate prepolymer. Next, 646.3 parts of the obtained terminal isocyanate prepolymer solution were gradually added at room temperature to a mixture of 16.3 parts of 2-hydroxyethylethylenediamine and 400 parts of acetone, and reacted at 50°C for 3 hours to obtain a solvent-type urethane resin solution. Next, 9.76 parts of 28% aqueous ammonia and 500 parts of deionized water were gradually added to the solvent-type polyurethane resin solution to neutralize it and make it water-soluble. After further removing all of the methyl ethyl ketone and acetone under azeotropic distillation, water was added to adjust the viscosity and obtain an aqueous urethane resin PU1 solution (solid content 40%). The aqueous urethane resin PU1 is an aqueous urethane resin with an acid value of 30 mg KOH / g, a glass transition temperature of -40°C, and a weight-average molecular weight of 22,000, and has constituent units derived from polyester polyol.

[0103] <Synthesis Example 2> Synthesis of aqueous urethane resin PU2 solution In a reactor equipped with a thermometer, stirrer, reflux condenser, and nitrogen gas inlet, 146.19 parts of polytetramethylene glycol with a number average molecular weight of 2000, 35.55 parts of polyethylene glycol with a number average molecular weight of 2000, 21.57 parts of 2,2-dimethylolpropionic acid, and 84.07 parts of isophorone diisocyanate were reacted at a boiling point for 6 hours in 200 parts of methyl ethyl ketone to obtain a terminal isocyanate prepolymer. After cooling to 40°C, 100 parts of acetone were added to obtain a terminal isocyanate prepolymer solution. Next, 587.38 parts of the obtained terminal isocyanate prepolymer solution were gradually added at room temperature to a mixture of 8.73 parts of 2-hydroxyethylethylenediamine, 2.91 parts of isophoronediamine, and 400 parts of acetone, and reacted at 50°C for 3 hours to obtain a solvent-type polyurethane resin solution. Next, 9.76 parts of 28% aqueous ammonia and 450 parts of deionized water were gradually added to the solvent-type polyurethane resin solution to neutralize it and make it water-soluble. After further removing all of the methyl ethyl ketone and acetone under azeotropic distillation, water was added to adjust the viscosity and obtain an aqueous polyurethane resin PU2 solution (solid content 40%). The aqueous polyurethane resin PU2 is an aqueous urethane resin with an acid value of 30 mg KOH / g, a glass transition temperature of 25°C, and a weight-average molecular weight of 30,000, and has constituent units derived from polyether polyols.

[0104] <Synthesis Example 3> Synthesis of aqueous urethane resin PU3 solution In a reactor equipped with a thermometer, stirrer, reflux condenser, and nitrogen gas inlet, 235.6 parts of polycarbonate diol with a number average molecular weight of 2000 derived from 1,6-hexanediol units, 10.7 parts of polyethylene glycol with a number average molecular weight of 2000, 30.0 parts of 2,2-dimethylolpropanoic acid, and 250 parts of methyl ethyl ketone were mixed and stirred while nitrogen gas was introduced. 91.5 parts of isophorone diisocyanate were added dropwise over 1 hour, and the mixture was reacted at 80°C for 4 hours to obtain a terminal isocyanate prepolymer. After cooling to 30°C, 100 parts of isopropanol were added to obtain a solvent solution of the terminal isocyanate prepolymer. To the obtained terminal isocyanate prepolymer, a mixture of 2.7 parts of 2-aminoethylethanolamine and 150 parts of isopropanol was gradually added at room temperature, and the mixture was reacted at 40°C for 2 hours to obtain a solvent-type urethane resin solution. Next, 13.6 parts of 28% aqueous ammonia and 851 parts of deionized water were gradually added to the solvent-type urethane resin solution to neutralize it and make it water-soluble. After further removing methyl ethyl ketone and isopropanol by vacuum distillation, water was added to adjust the solid content to obtain an aqueous urethane resin PU3 solution (solid content 40%). The aqueous urethane resin PU3 is an aqueous urethane resin with an acid value of 35 mg KOH / g, a glass transition temperature of -15°C, and a weight-average molecular weight of 35,000, and has constituent units derived from polycarbonate polyol.

[0105] <Synthesis Example 4> Synthesis of Water-Based Urethane Resin PU4 Solution In a reactor equipped with a thermometer, stirrer, reflux condenser, and nitrogen gas inlet tube, 29.7 parts of dimethylolbutanoic acid, 156.4 parts of polyethylene glycol with a number average molecular weight of 2000, and 67 parts of hydride of alcohol-modified dicyclopentadiene polymer (number average molecular weight 610, hydroxyl value 200 mg KOH / g) were mixed and stirred while introducing nitrogen gas. 121.95 parts of isophorone diisocyanate were added dropwise over 1 hour, and the mixture was reacted at 80°C for 4 hours to obtain a terminal isocyanate prepolymer. The mixture was then cooled to 30°C to obtain the terminal isocyanate prepolymer. To the obtained terminal isocyanate prepolymer, a mixture of 550 parts of water, 85 parts of isopropyl alcohol, 20.25 parts of triethylamine, and 26.3 parts of adipic acid hydrazide was gradually added at room temperature, and the mixture was reacted at 40°C for 2 hours to obtain an aqueous urethane resin solution, PU4 solution (solids content 40%). Furthermore, the aqueous urethane resin solution PU4 is an aqueous urethane resin with an acid value of 30 mg KOH / g, a glass transition temperature of -20°C, and a weight-average molecular weight of 40,000, and contains constituent units derived from polyolefin polyols.

[0106] <Manufacturing Example 1> Manufacturing of Printing Ink W1 Phthalocyanine-based blue pigment (Toyo Color Co., Ltd. Lionol Blue FG-7400G (CI Pigment Blue 15:4, Solids 100%)) 10 parts, Water 13.5 parts, Aqueous acrylic resin emulsion AC1 50 parts (Weight-average molecular weight 240,000, Acid value 51 mg KOH / g, Glass transition temperature: 30℃, Solids 40%), Water-soluble acrylic resin solution AC3 10 parts (Weight-average molecular weight 5,000, Acid value: 50 mg KOH / g, Glass transition temperature: 110℃, Solids 40%), Isopropyl alcohol 15 parts, Acetylene-based surfactant (Solids 100%, HLB value = 6) 1 part, Polyethylene wax (Particle size (Coulter counter method): 3 μm, Hardness (Penetration): 1 or less, Solids 40%) 0.5 parts, Silicone-based defoamer (Solids 100%) Printing ink W1 was obtained by mixing 0.01 parts and dispersing them in a bead mill for 15 minutes.

[0107] <Manufacturing Examples 2-33, Comparative Manufacturing Examples 1-5> Manufacturing of Printing Inks W2-W38 Printing inks W2 to W32 were obtained using the same method as in Manufacturing Example 1, except that the raw materials and mixing ratios listed in Tables 1 and 2 were used. The properties of the raw materials used are as follows. • Aqueous acrylic resin emulsion AC2 (weight-average molecular weight 250,000, acid value 35 mg KOH / g, glass transition temperature: 25°C, solids content 40%) • Water-soluble acrylic resin solution AC4 (weight-average molecular weight 6000, acid value 80 mg KOH / g, glass transition temperature: 100°C, solids content 40%) • Water-soluble acrylic resin solution AC5 (weight-average molecular weight 5500, acid value 215 mg KOH / g, glass transition temperature: 85°C, solids content 40%) • Water-soluble acrylic resin solution AC6 (weight-average molecular weight 10000, acid value 41 mg KOH / g, glass transition temperature: 90°C, solids content 40%) • Vinyl chloride emulsion PVC1 (manufactured by Nisshin Chemical Co., Ltd., Vinibran 278, glass transition temperature: 30℃, solids content 40%) • Alcohol alkoxylate surfactant (100% solids, HLB value = 8) • Acrylic surfactant (100% solids, HLB value = 7) • Fluorine-based surfactant (100% solids, HLB value = 7) • Silicone-based surfactant (100% solids, HLB value = 14)

[0108] [Table 1-1]

[0109] [Table 1-2]

[0110] [Table 2-1]

[0111] [Table 2-2]

[0112] <Manufacturing Example 34> Manufacturing of coating agent S1 containing a sizing agent 2500 parts of alkyl ketene dimer (SE2360, manufactured by Seikoh PMC, 20% solids content) and 7500 parts of a mixed solvent (water / isopropanol = 1 / 1) were mixed and stirred to obtain coating agent S1 containing a sizing agent.

[0113] <Manufacturing Examples 35-39> Manufacturing of coating agents S2-6 containing sizing agents Coating agents S2-6 containing a sizing agent were obtained using the same method as in Production Example 34, except that the raw materials and mixing ratios listed in Table 3 were used. The properties of the raw materials used are as follows. • Rosin resin (manufactured by Arakawa Chemical Industries, Ltd., Polymalon 351T, solids content 20%) • Alkenyl succinate (manufactured by Arakawa Industries, SP864, solids content 20%) • Polyvinyl alcohol resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., Gosenal T-350, solids content 20%) • Starch resin (manufactured by Nippon Corn Starch Co., Ltd., SK-20, solids content 20%)

[0114] [Table 3]

[0115] <Manufacturing Example 40> Manufacturing of Overcoat Agent V1 72 parts of nitrocellulose nc1 (manufactured by NOBEL, product name NC DHX 5-10, NV. 70% (solvent: isopropyl alcohol), weight-average molecular weight: 10,000, viscosity at 25.0% solution concentration: 2 seconds) were mixed and dissolved in 33.6 parts of ethyl acetate and 33.6 parts of isopropyl alcohol to obtain a nitrocellulose resin solution (NC1) with a solid content of 30%. Next, 65.5 parts of the nitrocellulose resin solution NC1, 5.5 parts of N-propyl acetate, 3 parts of ethyl acetate, 5.5 parts of isopropyl alcohol, 5.4 parts of methylcyclohexane, 0.9 parts of methylpropylene glycol, 0.9 parts of water, 1.85 parts of diethylene glycol monobutyl ether (NV. 100%), and 3 parts of hexamene bisoleamide (NV. 100%) were stirred and mixed to obtain overcoat agent V1.

[0116] <Manufacturing Example 41> Manufacturing of Overcoat Agent V2 The following ingredients were added and stirred to obtain overcoat agent V2: 14.49 parts water, 60 parts aqueous acrylic emulsion AC1, 20 parts aqueous acrylic emulsion AC2, 2 parts diethylene glycol monobutyl ether, 3 parts polyethylene wax, 0.5 parts phosphate ester compound (Phosphanol RA-600, manufactured by Toho Chemical Industry Co., Ltd., polyoxyethylene alkyl ether phosphate ester, 100% solids), and 0.01 parts defoaming agent (TEGO® Foamex 1488, manufactured by EVONIC, 100% solids).

[0117] <Manufacturing Example 42> Manufacturing of Overcoat Agent V3 Water (14.49 parts), aqueous urethane resin (PU1) (80 parts), diethylene glycol monobutyl ether (2 parts), polyethylene wax (3 parts), phosphate ester compound (Phosphanol RA-600, manufactured by Toho Chemical Industry Co., Ltd., polyoxyethylene alkyl ether phosphate ester, 100% solids) (0.5 parts), and defoaming agent (TEGO® Foamex 1488, manufactured by EVONIC, 100% solids) (0.01 parts) were added, stirred, and mixed to obtain aqueous overcoat agent V3.

[0118] (Manufacturing of laminates) <Example 1> Production of laminate P1 500 parts of softwood kraft pulp (CSF drainage: 500 ml, solvent: water) and 500 parts of hardwood kraft pulp (CFS drainage: 500 ml, solvent: water) were mixed with 11 parts of cationized starch (Grain Processing Corporation, CHARGEMASTER R462) as a paper strengthening agent and 10 parts by mass of aluminum sulfate to obtain a paper stock. Using a Fourdrinier paper machine, the paper stock was formed into a base material k1 with a basis weight of 65 g / m 2 was obtained. Using a tabletop size press machine (manufactured by Kumagai Riki Kogyo Co., Ltd.) capable of simultaneously applying an equal amount of coating to both sides of the base material k1 obtained above, a coating agent S1 containing a sizing agent was applied so that the total dried coating amount on both sides was 0.3 g / m 2 and dried in an oven at 60°C to obtain a paper base material K1 containing a sizing agent. Printing ink W1 was diluted with a diluting solvent (water / isopropyl alcohol = 30 / 70) to a viscosity of 15 seconds (25°C) using a Zahn cup #3 (manufactured by Rheometric Scientific). Then, using a gravure printing machine equipped with a gravure plate engraved at 175 lines / inch, the diluted printing ink W1 was printed on the entire surface of the paper base material K1 containing a sizing agent under the conditions of a printing speed of 40 m / min and an in-line oven at 90°C to form a printing layer, and an intermediate laminate p1 having a structure of paper base material / printing layer was obtained. On the printing layer of the paper base material in the intermediate laminate p1, a polyethylene resin (melting point: 120°C) was heat-melted and extruded under the conditions of a resin temperature of 330°C, a coating speed of 80 m / min, and a coating thickness of 10 μm to form a surface protection layer. Further, on the opposite surface of the surface protection layer of the paper base material of the intermediate laminate p1, a polyethylene resin (melting point: 120°C) was heat-melted and extruded under the conditions of a resin temperature of 330°C, a coating speed of 80 m / min, and a coating thickness of 20 μm to obtain a laminate P1 having a structure of heat-sealing layer / paper base material / printing layer / surface protection layer. The coating amount of the printing layer of the laminate P1 was 2 g / m 2 was.

[0119] <Examples 2 to 25, 29 to 52, Comparative Examples 1 to 7> Production of laminates P2 to 25, 29 to 52, PP1 to 7 Laminates P2-25, 29-52, and PP1-7 were obtained in the same manner as in Example 1, except for changes to the raw materials and coating method described in Tables 3-6.

[0120] <Example 26> Manufacturing of laminate P26 Printing ink W1 was diluted with a diluent solvent (water / isopropyl alcohol = 30 / 70) to a Zahn cup #3 (manufactured by Rigosha) for 15 seconds (25°C), and overcoat agent V1 was diluted with a diluent solvent (ethyl acetate / isopropyl alcohol = 70 / 30) to a Zahn cup #3 (manufactured by Rigosha) for 15 seconds (25°C). Then, the diluted printing ink W1 was printed over the entire surface of the paper substrate K1 containing the sizing agent using a gravure printing press equipped with a 175 lines / inch helio-engraved gravure plate, at a printing speed of 40 m / min and in an in-line oven at 90°C to form a printed layer, obtaining an intermediate laminate p26 having a paper substrate / printed layer structure. On the printed layer of the paper substrate in the intermediate laminate p26, a diluted overcoat agent V1 was printed using a gravure printing press equipped with a 175 lines / inch helio-engraved gravure plate at a printing speed of 40 m / min and an in-line oven at 90°C to form a surface protective layer. Furthermore, polyethylene resin (melting point: 120°C) was hot-melt extruded onto the opposite side of the surface protective layer of the paper substrate of the intermediate laminate p22 at a resin temperature of 330°C, a coating speed of 80 m / min, and a coating thickness of 20 μm to obtain laminate P26, which consists of a heat-seal layer / paper substrate / printed layer / surface protective layer. The coating amount of the printed layer of laminate P26 was 2 g / m². 2 That was the case.

[0121] <Examples 27 and 28, 53-55> Manufacturing of laminates P27, P28, and P53-55 Laminates P27, P28, and P53-55 were obtained in the same manner as in Example 26, except that the overcoat agents described in Tables 4 and 5 were used. The solvents used to dilute the overcoat agent are as follows: Overcoat agent V1: Ethyl acetate / isopropyl alcohol = 70 / 30 Overcoat agents V2 and V3: Water / Isopropyl alcohol = 30 / 70

[0122] <Characteristic Evaluation> The intermediate laminates p1-55 and pp1-7, and the laminates P1-55 and PP1-7 obtained in the above examples and comparative examples were evaluated as described below. The evaluation results are shown in Tables 4-6.

[0123] <Adhesion> The surface of the printed layer of the obtained intermediate laminate was subjected to a 15mm wide x 200mm cellophane tape, and the condition of the printed layer after rapidly peeling it off was evaluated according to the following criteria. Practicality levels are rated from A to C. Evaluation Criteria A: A 100% area print layer remained on the paper substrate. B: A printed layer covering 80% or more but less than 100% of the paper substrate remained. C: A printed layer covering 50% or more but less than 80% of the paper substrate remained. D: Less than 50% of the printed layer remained on the paper substrate.

[0124] <Concentration> The print density of the obtained intermediate laminate was measured using X-RiteeXact (density status: ISO status E, white reference: absolute value, filter: none, illuminant / observer field of view: D50 / 2°) manufactured by X-Rite. The practical level is A to C. A: Print layer density is 1.60 or higher B: Print layer density is 1.50 or higher, but less than 1.60. C: Print layer density is 1.40 or higher, but less than 1.50. D: Print layer density is less than 1.40

[0125] <Leveling properties> The degree of unevenness in the printing layer and coating of the resulting intermediate laminate was visually evaluated. The practical level is rated from A to C. (Evaluation Criteria) A: Those that show no unevenness in application or hardly any unevenness in application. B: Slightly uneven coating is visible. C: Some unevenness and uneven application are observed. D: Severely uneven application due to swimming.

[0126] <Heat sealability evaluation> Two samples measuring 15 mm x 100 mm were cut from the obtained laminate, designated as sample (1) and sample (2). The heat-sealed layer of sample (1) and the surface protective layer of sample (2) were placed in contact with each other. Furthermore, a PET silicone separator film (manufactured by Nipper Co., Ltd., thickness: 75 μm) was placed on top of the surface protective layer of sample (1), and the layers were heat-sealed from the PET silicone separator film side using the following apparatus and conditions. After heat sealing, the PET silicone separator film was peeled off sample (1), and the unsealed ends were fixed to a small tensile testing machine to evaluate the heat seal strength. The practical level is A to C. Heat sealing conditions Equipment: Heat seal tester manufactured by Tester Industries Co., Ltd., seal width: 10 mm from the edge of the sample, heater temperature: 200℃, seal pressure: 2 kg / cm 2 , Seal time: 1 sec Heat seal strength measurement conditions Equipment: Intesco small tensile testing machine (model; IM-20), specimen width: 15 mm, Peeling mode: 90° peeling, tensile speed: 300 mm / min Evaluation Criteria A: The heat seal strength is 5.0N or higher. B: The heat seal strength is 3.5N or more and less than 5.0N. C: The heat seal strength is 1.0N or more and less than 3.5N. D: The heat seal strength is less than 1.0 N.

[0127] [Table 4-1]

[0128] [Table 4-2]

[0129] [Table 4-3]

[0130] [Table 5-1]

[0131] [Table 5-2]

[0132] [Table 5-3]

[0133] [Table 6]

[0134] From the above results, Comparative Example 1 had poor concentration and leveling properties because the printed layer did not contain acrylic resin (A) and urethane resin (B). Comparative Examples 2 and 4 had poor adhesion and leveling properties because the amount of surfactant in the printed layer was less than the specified amount. Comparative Examples 3 and 5 had poor adhesion and heat sealability because the amount of surfactant in the printed layer exceeded the specified amount. Comparative Examples 6 and 7 had poor adhesion, concentration, leveling properties, and heat sealability because the paper substrate did not contain a sizing agent. In the other example, the printed layer contained acrylic resin (A) and / or urethane resin (B), the surfactant content in the printed layer was 0.05 to 20% by mass of 100% by mass of the printed layer, and the paper substrate contained a sizing agent, resulting in good adhesion, density, leveling properties, and heat sealability.

Claims

1. A laminate having, in this order, a heat seal layer, a paper substrate containing a sizing agent, a printing layer, and a surface protective layer, The printed layer comprises a binder resin, a surfactant, and a colorant. The binder resin comprises urethane resin (B), The urethane resin (B) has a polyester polyol structure and / or a polyether polyol structure derived from a polycarboxylic acid, The content of the surfactant is 0.05 to 20% by mass of 100% by mass of the printed layer. A laminate comprising the surface protective layer and the heat seal layer, each containing a polyolefin resin.

2. A laminate having, in this order, a heat seal layer, a paper substrate containing a sizing agent, a printing layer, and a surface protective layer, The printed layer comprises a binder resin, a surfactant, and a colorant. The binder resin comprises acrylic resin (A), The weight-average molecular weight of the acrylic resin (A) is 25,000 to 600,000. The content of the surfactant is 0.05 to 20% by mass of 100% by mass of the printed layer. A laminate comprising the surface protective layer and the heat seal layer, each containing a polyolefin resin.

3. The laminate according to claim 1 or 2, wherein the surfactant comprises at least one selected from the group consisting of acetylene-based surfactants, alcohol alkoxylate-based surfactants, silicone-based surfactants, acrylic-based surfactants, and fluorine-based surfactants.

4. The laminate according to claim 1 or 2, wherein the total solid content of acrylic resin (A) and urethane resin (B) is 75% by mass or more of the solid content of 100% by mass of the binder resin.

5. The laminate according to claim 1 or 2, wherein the printed layer further comprises a hydrocarbon wax.

6. The laminate according to claim 1 or 2, wherein the solid content mass ratio of the surfactant to the binder resin in the printed layer is 1:99 to 50:

50.

7. The laminate according to claim 1 or 2, wherein the solid content mass ratio of surfactant to colorant in the printed layer is 1:99 to 40:

60.

8. The sizing agent is rosin resin, alkenyl succinate, alkyl ketene dimer, polyvinyl It is at least one selected from the group consisting of alcohol resins and starch resins. The laminate described in item 1 or 2.

9. The laminate according to claim 1 or 2, wherein the mass ratio of the sizing agent content in the paper substrate per unit area to the surfactant content in the printed layer per unit area is 0.1:99.9 to 50:

50.

10. The laminate according to claim 1 or 2, wherein the mass ratio of the content of sizing agent in the paper substrate per unit area to the content of acrylic resin (A) and urethane resin (B) in the printed layer per unit area is 0.1:99.9 to 30:

70.

11. A laminate according to claim 1 or 2, for use as a packaging container.

12. A method for manufacturing a laminate having, in this order, a heat seal layer, a paper substrate containing a sizing agent, a printing layer, and a surface protective layer, Printing ink containing a binder resin, a surfactant, and a colorant onto the aforementioned paper substrate. The process includes forming the aforementioned printed layer, The binder resin comprises urethane resin (B), The urethane resin (B) has a polyester polyol structure and / or a polyether polyol structure derived from a polycarboxylic acid, The surfactant is present in an amount of 0.05 to 20% by mass of 100% by mass of the printed layer. A method for manufacturing a laminate, wherein the surface protective layer and the heat seal layer contain a polyolefin resin.

13. A method for manufacturing a laminate having, in this order, a heat seal layer, a paper substrate containing a sizing agent, a printing layer, and a surface protective layer, Printing ink containing a binder resin, a surfactant, and a colorant onto the aforementioned paper substrate. The process includes forming the aforementioned printed layer, The binder resin comprises acrylic resin (A), The weight-average molecular weight of the acrylic resin (A) is 25,000 to 600,000. The surfactant is present in an amount of 0.05 to 20% by mass of 100% by mass of the printed layer. A method for manufacturing a laminate, wherein the surface protective layer and the heat seal layer contain a polyolefin resin.

14. The printing ink further contains a solvent, and the solvent is an alcohol solvent, which is the entirety of the printing ink. A method for producing a laminate according to claim 12 or 13, comprising 1 to 70% by mass of the solvent.

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