Laminate

Abstract

This multilayer body (1) comprises: a base material (2); a first resin layer (3) which is arranged on at least one surface of the base material (2) and contains a first resin component; and a second resin layer (4) which is arrange on one surface of the first resin layer (3) and contains a second resin component. The first resin component contains a first ethylene / unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1). The proportion of the first ethylene / unsaturated carboxylic acid copolymer (A1) relative to the total amount of the first resin component is 25% by mass to 90% by mass. The first acrylic polymer (B1) has a glass transition temperature of -30°C to 15°C. The second resin component contains a second ethylene / unsaturated carboxylic acid copolymer (A2). The proportion of the second ethylene / unsaturated carboxylic acid copolymer (A2) relative to the total amount of the second resin component is 95% by mass or more.

Description

[Technical field]

[0001] The present invention relates to a laminate comprising a substrate and a resin layer. [Background technology]

[0002] In various industrial fields, laminates in which various functional resin layers are coated on the surface of a substrate are widely used. More specifically, for example, laminates in which an aqueous dispersion of a resin is applied to a substrate and then dried are known as laminates. In addition, for example, the following aqueous dispersions are known as aqueous dispersions. That is, the aqueous dispersion contains a resin component and water. The resin component contains composite particles (C) and resin particles (E). The composite particles (C) contain an ethylene-unsaturated carboxylic acid copolymer (A) and an acrylic polymer (B). The resin particles (E) contain an ethylene-unsaturated carboxylic acid copolymer (A) as an olefin copolymer (D) (see, for example, Patent Document 1 (Example 1)). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2016 / 076130 Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the application, the laminate may be required to have better blocking resistance.

[0005] Furthermore, the laminate is required to have water resistance, oil resistance, and heat sealability, as well as improved production efficiency.

[0006] The present invention provides a laminate that is excellent in blocking resistance, water resistance, oil resistance, heat sealability and production efficiency. [Means for solving the problem]

[0007] The present invention [1] includes a laminate comprising a substrate, a first resin layer disposed on at least one side of the substrate and containing a first resin component, and a second resin layer disposed on the one side of the first resin layer and containing a second resin component, the first resin component containing a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1), the proportion of the first ethylene-unsaturated carboxylic acid copolymer (A1) being 25% by mass or more and 90% by mass or less with respect to the total amount of the first resin component, and the glass transition temperature of the first acrylic polymer (B1) being -30°C or more and 15°C or less, the second resin component containing a second ethylene-unsaturated carboxylic acid copolymer (A2), the proportion of the second ethylene-unsaturated carboxylic acid copolymer (A2) being 95% by mass or more with respect to the total amount of the second resin component.

[0008] The present invention [2] includes the laminate according to the above [1], wherein the first resin component includes composite particles (C1) containing the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1).

[0009] The present invention [3] is characterized in that the amount of the first resin layer is 1 g / m 2 More than 14g / m 2 The amount of the second resin layer is 1 g / m or less. 2 More than 14g / m 2 or less, and the total amount of the first resin layer and the second resin layer is 2 g / m 2 More than 15g / m 2 The laminate comprises the laminate described in [1] or [2] above, which is as follows: Effect of the Invention

[0010] The laminate of the present invention comprises a substrate, a first resin layer containing a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1), and a second resin layer containing a second ethylene-unsaturated carboxylic acid copolymer (A2). In the first resin layer, the proportion of the ethylene-unsaturated carboxylic acid copolymer (A1) is adjusted to a predetermined range. In the first resin layer, the glass transition temperature of the first acrylic polymer (B1) is adjusted to a predetermined range. In the second resin layer, the proportion of the second ethylene-unsaturated carboxylic acid copolymer (A2) is a predetermined value or more.

[0011] In such a laminate, the second resin layer also has excellent blocking resistance. Therefore, the laminate has excellent blocking resistance. Furthermore, the first resin layer also has excellent water resistance and oil resistance. Therefore, the laminate has excellent water resistance and oil resistance.

[0012] Furthermore, the first resin layer has excellent blocking resistance, so that even if the second resin layer is not disposed, the substrate and the first resin layer can be transported efficiently, and the second resin layer can be laminated efficiently, resulting in improved production efficiency of the laminate.

[0013] In addition, by disposing the second resin layer on one side of the first resin layer, the laminate exhibits excellent heat seal properties.

[0014] As a result, the laminate of the present invention has excellent blocking resistance, water resistance, oil resistance, heat sealability and production efficiency. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing one embodiment of a laminate of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In Figure 1, the laminate 1 comprises a base material 2, a first resin layer 3 arranged (laminated) on one side of the surface of the base material 2 (the upper side of the paper), and a second resin layer 4 arranged (laminated) on one side of the surface of the first resin layer 3 (the upper side of the paper).

[0017] Examples of the substrate 2 include fiber substrates, plastic substrates, and metal substrates. Examples of the fiber substrates include paper, woven fabric, and nonwoven fabric. Examples of the plastic substrates include films made of resin. Examples of the resins include cellophane, polyethylene, ethylene-vinyl acetate copolymers, ionomers, polypropylene, polyamide (nylon), polyester, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymers, polycarbonate, polystyrene, and polyacrylonitrile copolymers. Examples of the metal substrates include thin films made of metal. Examples of the metals include aluminum, gold, silver, copper, nickel, zinc, titanium, cobalt, indium, and chromium.

[0018] Further, a vapor-deposited film can also be used as the substrate 2. The vapor-deposited film is formed by vapor-depositing the above-mentioned metal and / or its oxide onto a film made of the above-mentioned resin.

[0019] These substrates 2 can be used alone or in combination of two or more kinds. As the substrate 2, a fiber substrate is preferable, and paper is more preferable.

[0020] The substrate 2 may be subjected to a surface treatment as required. Examples of the surface treatment include a corona discharge treatment and a chemical conversion treatment.

[0021] The thickness of the substrate 2 is, for example, 0.1 μm or more, or preferably 1 μm or more. The thickness of the substrate 2 is, for example, 1000 μm or less, or preferably 500 μm or less.

[0022] In Fig. 1, the first resin layer 3 is laminated on one surface of the substrate 2. The first resin layer 3 contains a first resin component.

[0023] More specifically, the first resin layer 3 is, for example, a dried coating film of a dispersion liquid of a first resin component (hereinafter, may be referred to as a first coating material).

[0024] The first resin component contains a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1).

[0025] The first ethylene-unsaturated carboxylic acid copolymer (A1) is obtained by copolymerization of the A1 monomer component (a1). The A1 monomer component (a1) contains ethylene and an unsaturated carboxylic acid.

[0026] The unsaturated carboxylic acid is a monomer having at least one ethylenically unsaturated bond and a carboxyl group. Examples of the unsaturated carboxylic acid include unsaturated monobasic acids, unsaturated dibasic acids, and salts thereof. Examples of the unsaturated monobasic acids include acrylic acid, methacrylic acid, and crotonic acid. Examples of the unsaturated dibasic acids include maleic acid, fumaric acid, and itaconic acid. Examples of the salts include sodium salts, potassium salts, and ammonium salts. These can be used alone or in combination of two or more. From the viewpoint of water resistance and oil resistance, the unsaturated carboxylic acid is preferably an unsaturated monobasic acid, more preferably acrylic acid, methacrylic acid, and salts thereof, and particularly preferably methacrylic acid and its salts.

[0027] In addition, the unsaturated carboxylic acid may be used in combination with a vinyl ester, if necessary. Examples of the vinyl ester include vinyl carboxylate. Examples of the vinyl carboxylate include vinyl acetate and vinyl propionate. These can be used alone or in combination of two or more. When vinyl esters and unsaturated carboxylic acids are used in combination, the ratio between them is appropriately set according to the purpose and application.

[0028] In the monomer component (a1) for A1, preferably, vinyl esters are not used in combination. More specifically, the monomer component (a1) for A1 preferably comprises ethylene and an unsaturated carboxylic acid.

[0029] In the monomer component (a1) for A1, the content ratio of ethylene and unsaturated carboxylic acid (and vinyl esters (hereinafter the same) blended as necessary) is appropriately set according to the purpose and application.

[0030] For example, the amount of ethylene is, for example, 75% by mass or more, preferably 78% by mass or more, and more preferably 80% by mass or more, based on the total amount of ethylene and the unsaturated carboxylic acid. Also, the amount of ethylene is, for example, 90% by mass or less, preferably 88% by mass or less, and more preferably 85% by mass or less, based on the total amount of ethylene and the unsaturated carboxylic acid. below It is.

[0031] For example, the content of the unsaturated carboxylic acid is, for example, 10% by mass or more, preferably 12% by mass or more, more preferably 15% by mass or more, based on the total amount of ethylene and the unsaturated carboxylic acid. For example, the content of the unsaturated carboxylic acid is, for example, 25% by mass or less, preferably 22% by mass or less, more preferably 20% by mass or less, based on the total amount of ethylene and the unsaturated carboxylic acid.

[0032] In the monomer component (a1) for A1, when the content ratio of ethylene and unsaturated carboxylic acid is within the above range, excellent water resistance and oil resistance can be obtained.

[0033] The polymerization method of the monomer component (a1) for A1 is not particularly limited, and a known polymerization method is adopted. For example, the monomer component (a1) for A1 is polymerized in water under normal pressure. In the polymerization, for example, a polymerization initiator is mixed.

[0034] The polymerization initiator is not particularly limited, and examples thereof include hydrogen peroxide, organic peroxides, and persulfates. Examples of organic peroxides include cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxybenzoate, and lauroyl peroxide. Examples of persulfates include ammonium persulfate, potassium persulfate, and sodium persulfate. Examples of azo compounds include azobisisobutyronitrile. Examples of polymerization initiators include known redox initiators. These can be used alone or in combination of two or more. The mixing ratio of the polymerization initiator is appropriately set according to the purpose and application.

[0035] In the polymerization of the monomer component (a1) for A1, an emulsifier (surfactant) is added as necessary. Examples of the emulsifier include anionic surfactants, nonionic surfactants, and cationic surfactants.

[0036] Examples of anionic surfactants include sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium alkyldiphenyletherdisulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium stearate, potassium oleate, sodium dioctylsulfosuccinate, sodium polyoxyethylene alkylether sulfate, sodium polyoxyethylene alkylether sulfate, sodium polyoxyethylene alkylphenylether sulfate sodium dialkylsulfosuccinate, sodium stearate, sodium oleate, and sodium tert-octylphenoxyethoxypolyethoxyethyl sulfate. Examples of nonionic surfactants include polyoxyethylene lauryl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleylphenyl ether, polyoxyethylene nonylphenyl ether, oxyethylene-oxypropylene block copolymer, tert-octylphenoxyethyl polyethoxyethanol, and nonylphenoxyethyl polyethoxyethanol. Examples of cationic surfactants include lauryl trimethyl ammonium chloride and stearyl trimethyl ammonium chloride. These can be used alone or in combination of two or more. Examples of emulsifiers include anionic surfactants, and more preferably, sodium dodecylbenzenesulfonate. The blending ratio of the emulsifier is appropriately set according to the purpose and application.

[0037] In addition, in the polymerization of the monomer component (a1) for A1, additives are added as necessary. Examples of additives include pH adjusters, metal ion sequestering agents, molecular weight regulators, and chain transfer agents. These can be used alone or in combination of two or more. The mixing ratio of the additives is appropriately set depending on the purpose and application.

[0038] The polymerization method of the monomer component (a1) for A1 is described in known documents, such as JP-B-7-008933, JP-B-5-039975, JP-B-4-030970, JP-B-42-000275, JP-B-42-023085, JP-B-45-029909, and JP-A-51-062890.

[0039] The polymerization temperature and polymerization time of the monomer component (a1) for A1 are appropriately set depending on the type and amount of the monomer component (a1) for A1.

[0040] As a result, a first ethylene-unsaturated carboxylic acid copolymer (A1) is obtained as a polymer of the A1 monomer component (a1).

[0041] From the viewpoint of dispersion stability, the first ethylene-unsaturated carboxylic acid copolymer (A1) is preferably neutralized by adding a neutralizing agent to the reaction solution after completion of the polymerization.

[0042] Examples of the neutralizing agent include basic compounds. Examples of the basic compounds include inorganic basic compounds and organic basic compounds. Examples of the inorganic basic compounds include sodium hydroxide and potassium hydroxide. Examples of the organic basic compounds include ammonia, triethylamine, triethanolamine, and dimethylethanolamine. These can be used alone or in combination of two or more kinds.

[0043] The amount of the neutralizing agent added is, for example, 5 mol or more, preferably 30 mol or more, and more preferably 50 mol or more, per 100 mol of carboxy groups in the first ethylene-unsaturated carboxylic acid copolymer (A1). The amount of the neutralizing agent added is, for example, 200 mol or less, and preferably 150 mol or less, per 100 mol of carboxy groups in the first ethylene-unsaturated carboxylic acid copolymer (A1).

[0044] After the neutralizing agent is added to the reaction-terminated liquid, the reaction-terminated liquid is preferably held at a predetermined temperature for a predetermined time. The holding temperature is, for example, 40° C. or higher, preferably 50° C. or higher. The holding temperature is, for example, 90° C. or lower, preferably 80° C. or lower. The holding time is, for example, 30 minutes or longer, preferably 1 hour or longer. The holding time is, for example, 12 hours or shorter, preferably 10 hours or shorter.

[0045] As a result, the copolymer is neutralized and hydrated in the reaction-completed liquid, and is further swollen and softened.

[0046] Furthermore, when an unsaturated monobasic acid and / or an unsaturated dibasic acid is used as the unsaturated carboxylic acid, the unsaturated monobasic acid and / or the unsaturated dibasic acid become their salts by the above-mentioned neutralization and hydration.

[0047] The degree of neutralization of the first ethylene-unsaturated carboxylic acid copolymer (A1) is, for example, 30% or more, preferably 50% or more, and for example, 200% or less, preferably 150% or less.

[0048] The weight average molecular weight (standard polystyrene equivalent) of the first ethylene-unsaturated carboxylic acid copolymer (A1) is, for example, 10,000 or more, preferably 30,000 or more. The weight average molecular weight (standard polystyrene equivalent) of the first ethylene-unsaturated carboxylic acid copolymer (A1) is, for example, 200,000 or less, preferably 150,000 or less. The weight average molecular weight is measured by gel permeation chromatography (GPC) (hereinafter the same).

[0049] The first ethylene-unsaturated carboxylic acid copolymer (A1) has a melting point of, for example, 55° C. or more, preferably 65° C. or more, and for example, 110° C. or less, preferably 100° C. or less. The melting point can be determined by DSC (differential scanning calorimetry) (hereinafter the same).

[0050] In the above method, preferably, a dispersion in which resin particles of the first ethylene-unsaturated carboxylic acid copolymer (A1) are dispersed in water is obtained.

[0051] The dispersion of the first ethylene-unsaturated carboxylic acid copolymer (A1) has a solid content concentration of, for example, 10 mass% or more, preferably 20 mass% or more. The dispersion of the first ethylene-unsaturated carboxylic acid copolymer (A1) has a solid content concentration of, for example, 60 mass% or less, preferably 50 mass% or less.

[0052] The first ethylene-unsaturated carboxylic acid copolymer (A1) has an average particle size (measurement method: light scattering measurement) of, for example, 0.01 μm or more, preferably 0.02 μm or more. The first ethylene-unsaturated carboxylic acid copolymer (A1) has an average particle size (measurement method: light scattering measurement) of, for example, 10 μm or less, preferably 1 μm or less.

[0053] The dispersion of the first ethylene-unsaturated carboxylic acid copolymer (A1) can also be obtained as a commercially available product. Examples of commercially available products include Chemipearl S100 (ethylene content in raw material: 85% by mass, type of unsaturated carboxylic acid: methacrylic acid, neutralized with sodium hydroxide, solid content 27%, manufactured by Mitsui Chemicals), Chemipearl S80N (ethylene content in raw material: 80% by mass, type of unsaturated carboxylic acid: acrylic acid, neutralized with ammonium hydroxide, solid content 24%, manufactured by Mitsui Chemicals), Chemipearl S650 (ethylene content in raw material: 80% by mass, type of unsaturated carboxylic acid: methacrylic acid, neutralized with sodium hydroxide, solid content 27%, manufactured by Mitsui Chemicals), and Chemipearl S300 (ethylene content in raw material: 86.5% by mass, type of unsaturated carboxylic acid: methacrylic acid, neutralized with sodium hydroxide, solid content 35%, manufactured by Mitsui Chemicals). These can be used alone or in combination of two or more types.

[0054] Such a first ethylene-unsaturated carboxylic acid copolymer (A1) improves the water resistance and oil resistance of the first resin layer 3. Moreover, the above-mentioned first ethylene-unsaturated carboxylic acid copolymer (A1) improves the blocking resistance of the first resin layer 3. Moreover, the above-mentioned first ethylene-unsaturated carboxylic acid copolymer (A1) improves the heat seal property of the laminate 1 including the first resin layer 3 and the second resin layer 4.

[0055] The first acrylic polymer (B1) is obtained by polymerization of a monomer component (b1) for B1. The monomer component (b1) for B1 contains, for example, a (meth)acrylic acid ester. Here, (meth)acrylic refers to acrylic and / or methacrylic (hereinafter the same).

[0056] Examples of (meth)acrylic acid esters include (meth)acrylic acid esters having an alkyl moiety with 1 to 12 carbon atoms. Examples of (meth)acrylic acid esters having an alkyl moiety with 1 to 12 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate. These can be used alone or in combination of two or more.

[0057] The type of (meth)acrylic acid ester is selected so that the glass transition temperature of the first acrylic polymer (B1) is in the range described below.

[0058] More specifically, the (meth)acrylic acid ester is preferably a (meth)acrylic acid ester having an alkyl moiety having 1 to 4 carbon atoms, more preferably methyl (meth)acrylate and n-butyl (meth)acrylate, even more preferably methyl methacrylate, n-butyl methacrylate, and n-butyl acrylate, and particularly preferably n-butyl acrylate.

[0059] Furthermore, the monomer component (b1) for B1 may contain a copolymerizable monomer, if necessary. The copolymerizable monomer is a monomer that is copolymerizable with a (meth)acrylic acid ester.

[0060] The copolymerizable monomer may, for example, be a functional group-containing vinyl monomer.

[0061] Examples of functional group-containing vinyl monomers include carboxy group-containing vinyl monomers, hydroxy group-containing vinyl monomers, amino group-containing vinyl monomers, glycidyl group-containing vinyl monomers, cyano group-containing vinyl monomers, sulfonic acid group-containing vinyl monomers, acetoacetoxy group-containing vinyl monomers, phosphoric acid group-containing compounds, amide group-containing vinyl monomers, and salts thereof.

[0062] Examples of the carboxyl group-containing vinyl monomer include (meth)acrylic acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, and crotonic acid. Examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate. Examples of the amino group-containing vinyl monomer include 2-aminoethyl (meth)acrylate, 2-(N-methylamino)ethyl (meth)acrylate, and 2-(N,N-dimethylamino)ethyl (meth)acrylate. Examples of the glycidyl group-containing vinyl monomer include glycidyl (meth)acrylate. Examples of the cyano group-containing vinyl monomer include (meth)acrylonitrile. Examples of the sulfonic acid group-containing vinyl monomer include allylsulfonic acid and methallylsulfonic acid. Examples of the acetoacetoxy group-containing vinyl monomer include acetoacetoxyethyl (meth)acrylate. Examples of the phosphoric acid group-containing compound include 2-methacryloyloxyethyl acid phosphate. Examples of the amide group-containing vinyl monomer include (meth)acrylamide. Examples of the salt include sodium salt, potassium salt, and ammonium salt. These can be used alone or in combination of two or more kinds.

[0063] Copolymerizable monomers also include vinyl esters, aromatic vinyl monomers, N-substituted unsaturated carboxylic acid amides, heterocyclic vinyl compounds, vinylidene halide compounds, α-olefins, dienes, and crosslinkable vinyl monomers.

[0064] Examples of vinyl esters include vinyl acetate and vinyl propionate. Examples of aromatic vinyl monomers include styrene, α-methylstyrene, and divinylbenzene. Examples of N-substituted unsaturated carboxylic acid amides include N-methylol (meth)acrylamide. Examples of heterocyclic vinyl compounds include vinylpyrrolidone. Examples of halogenated vinylidene compounds include vinylidene chloride and vinylidene fluoride. Examples of α-olefins include ethylene and propylene. Examples of dienes include butadiene. Examples of crosslinkable vinyl monomers include compounds containing two or more vinyl groups, more specifically, methylene bis (meth) acrylamide, divinyl benzene, and polyethylene glycol chain-containing di (meth) acrylate. These can be used alone or in combination of two or more.

[0065] The type of copolymerizable monomer is selected so that the glass transition temperature of the first acrylic polymer (B1) falls within the range described below.

[0066] More specifically, the copolymerizable monomer is preferably a functional group-containing vinyl monomer or an aromatic vinyl monomer, more preferably a carboxy group-containing vinyl monomer or styrene, and even more preferably styrene.

[0067] In the monomer component for B1, the ratio of the (meth)acrylic acid ester to the copolymerizable monomer is selected so that the glass transition temperature of the first acrylic polymer (B1) falls within the range described below.

[0068] For example, the (meth)acrylic acid ester is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more, based on the total amount of the (meth)acrylic acid ester and the copolymerizable monomer. Also, the (meth)acrylic acid ester is, for example, 90% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on the total amount of the (meth)acrylic acid ester and the copolymerizable monomer. % The following is the result.

[0069] In addition, the copolymerizable monomer is, for example, 10 mass% or more, preferably 20 mass% or more, more preferably 30 mass% or more, and still more preferably 40 mass% or more, based on the total amount of the (meth)acrylic acid ester and the copolymerizable monomer. % In addition, the amount of the copolymerizable monomer relative to the total amount of the (meth)acrylic acid ester and the copolymerizable monomer is, for example, 90% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less, further preferably 60% by mass or less, and particularly preferably 50% by mass or less.

[0070] In the monomer component for B1, the copolymerizable monomer is preferably selected depending on the form of the first acrylic polymer (B1).

[0071] For example, when the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1) do not form composite particles (C1) described below, but the first acrylic polymer (B1) forms a single resin particle, the copolymerizable monomer preferably contains a functional group-containing vinyl monomer and an aromatic vinyl monomer.

[0072] For example, the content of the functional group-containing vinyl monomer relative to the total amount of copolymerizable monomers is, for example, 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more. Also, the content of the functional group-containing vinyl monomer relative to the total amount of copolymerizable monomers is, for example, 80% by mass or less, preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 30% by mass or less, particularly preferably 10% by mass or less.

[0073] For example, the aromatic vinyl monomer is, for example, 20% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, and particularly preferably 90% by mass or more, based on the total amount of copolymerizable monomers. For example, the aromatic vinyl monomer is, for example, 99% by mass or less, preferably 97% by mass or less, and more preferably 95% by mass or less, based on the total amount of copolymerizable monomers.

[0074] Furthermore, for example, when the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1) form the composite particle (C1) described below, the copolymerizable monomer preferably does not contain a functional group-containing vinyl monomer, and more preferably, the aromatic vinyl monomer is, for example, 100 mass% based on the total amount of the copolymerizable monomers.

[0075] The polymerization method of the monomer component (b1) for B1 is not particularly limited, and a known polymerization method is adopted. For example, the monomer component (b1) for B1 is polymerized in water under normal pressure. In the polymerization, for example, the polymerization initiator described above is mixed in an appropriate ratio.

[0076] In the polymerization of the monomer component (b1) for B1, the above-mentioned emulsifier (surfactant) and additives are added in an appropriate ratio, if necessary.

[0077] The polymerization temperature and polymerization time of the B1 monomer component (b1) are appropriately set according to the type and amount of the B1 monomer component (b1). For example, the polymerization temperature is, for example, 30°C or higher, preferably 50°C or higher. The polymerization temperature is, for example, 95°C or lower, preferably 85°C or lower. The polymerization time is, for example, 1 hour or higher, preferably 2 hours or higher. The polymerization time is, for example, 30 hours or lower, preferably 20 hours or lower.

[0078] As a result, a first acrylic polymer (B1) is obtained as a polymer of the B1 monomer component (b1).

[0079] The weight average molecular weight (standard polystyrene equivalent) of the first acrylic polymer (B1) is, for example, 5,000 or more, preferably 10,000 or more. The weight average molecular weight (standard polystyrene equivalent) of the first acrylic polymer (B1) is, for example, 1,000,000 or less, preferably 500,000 or less.

[0080] The glass transition temperature of the first acrylic polymer (B1) is −30° C. or higher, preferably −10° C. or higher, and more preferably −5° C. or higher.

[0081] When the glass transition temperature of the first acrylic polymer (B1) is higher than the lower limit, the first resin layer 3 has excellent blocking resistance. Therefore, even if the second resin layer 4 is not disposed, the transport efficiency of the substrate 2 and the first resin layer 3 is excellent, and the lamination efficiency of the second resin layer 4 is excellent. As a result, the production efficiency of the laminate 1 is improved.

[0082] The glass transition temperature of the first acrylic polymer (B1) is 15° C. or lower, preferably 10° C. or lower, and more preferably 5° C. or lower.

[0083] When the glass transition temperature of the first acrylic polymer (B1) is below the above upper limit, the first resin layer 3 has excellent water resistance and oil resistance, and as a result, the laminate 1 has excellent water resistance and oil resistance.

[0084] The glass transition temperature is calculated based on the FOX formula (hereinafter the same).

[0085] In the above method, a dispersion in which resin particles of the first acrylic polymer (B1) are dispersed in water is preferably obtained.

[0086] The dispersion of the first acrylic polymer (B1) has a solid content concentration of, for example, 10 mass% or more, or preferably 20 mass% or more. The dispersion of the first acrylic polymer (B1) has a solid content concentration of, for example, 60 mass% or less, or preferably 50 mass% or less.

[0087] The first resin layer 3 contains the above-mentioned first acrylic polymer (B1), and thus has excellent water resistance and oil resistance.

[0088] The first resin component may further contain other resins, so long as it contains the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1).

[0089] Examples of the other resins include known binder resins, and more specifically, examples of the other resins include polyester resins and polyurethane resins.

[0090] The first resin component preferably does not contain any other resins and is composed of a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1).

[0091] The proportion of the first ethylene-unsaturated carboxylic acid copolymer (A1) is 25 mass% or more, preferably 30 mass% or more, more preferably 40 mass% or more, even more preferably 50 mass% or more, and particularly preferably 60 mass% or more, based on the total amount of the first resin component.

[0092] When the proportion of the first ethylene-unsaturated carboxylic acid copolymer (A1) is greater than the above lower limit, the first resin layer 3 has excellent blocking resistance, and therefore, even if the second resin layer 4 is not disposed, the transport efficiency of the substrate 2 and the first resin layer 3 is excellent, and the production efficiency of the laminate 1 is improved.

[0093] The proportion of the first ethylene-unsaturated carboxylic acid copolymer (A1) is 90 mass % or less, preferably 85 mass % or less, more preferably 80 mass % or less, even more preferably 75 mass % or less, and particularly preferably 70 mass % or less, based on the total amount of the first resin component.

[0094] When the proportion of the first ethylene-unsaturated carboxylic acid copolymer (A1) is below the above upper limit, the first resin layer 3 has excellent water resistance and oil resistance, and as a result, the laminate 1 has excellent water resistance and oil resistance.

[0095] In addition, the proportion of the first acrylic polymer (B1) is 10 mass% or more, preferably 15 mass% or more, more preferably 20 mass% or more, even more preferably 25 mass% or more, and particularly preferably 30 mass% or more, based on the total amount of the first resin component.

[0096] The proportion of the first acrylic polymer (B1) is 75 mass % or less, preferably 70 mass % or less, more preferably 60 mass % or less, even more preferably 50 mass % or less, and particularly preferably 40 mass % or less, relative to the total amount of the first resin component.

[0097] In the first resin component, the form of the first ethylene-unsaturated carboxylic acid copolymer (A1) and the form of the first acrylic polymer (B1) are not particularly limited.

[0098] For example, the first resin component can contain resin particles consisting solely of the first ethylene-unsaturated carboxylic acid copolymer (A1) and resin particles consisting solely of the first acrylic polymer (B1).

[0099] In such a case, the dispersion of the first resin component (first coating material) is prepared by a known method. For example, first, the A1 monomer component (a1) is polymerized by the above-mentioned method. This results in a dispersion of resin particles consisting of the first ethylene-unsaturated carboxylic acid copolymer (A1) alone (hereinafter, sometimes referred to as A1 dispersion).

[0100] Separately from the above-mentioned A1 dispersion, the B1 monomer component (b1) is polymerized by the above-mentioned method, thereby obtaining a dispersion of resin particles composed solely of the first acrylic polymer (B1) (hereinafter, sometimes referred to as B1 dispersion).

[0101] Then, the A1 dispersion and the B1 dispersion are mixed so that the ratio of the first ethylene-unsaturated carboxylic acid copolymer (A1) and the ratio of the first acrylic polymer (B1) are within the above ranges.

[0102] As a result, a dispersion of a first resin component (first coating material) is obtained as a mixture of a dispersion of the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1).

[0103] In addition, the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1) can form composite particles (C1).

[0104] That is, the first resin component can contain composite particles (C1) containing a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1).

[0105] From the viewpoints of water resistance, oil resistance and blocking resistance, the first resin component preferably contains composite particles (C1) containing a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1).

[0106] The composite particle (C1) contains, for example, a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1), and is preferably composed of the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1).

[0107] The structure of the composite particle (C1) is not particularly limited, and may be, for example, a core-shell structure or a dispersion structure. In the core-shell structure, the core layer is covered with the shell layer. In the dispersion structure, the dispersion phase is dispersed in the continuous phase. The structure of the composite particle (C1) is preferably a dispersion structure.

[0108] In the dispersed structure, for example, the continuous phase may be the first ethylene-unsaturated carboxylic acid copolymer (A1) and the dispersed phase may be the first acrylic polymer (B1). In addition, in the dispersed structure, for example, the continuous phase may be the first acrylic polymer (B1) and the dispersed phase may be the first ethylene-unsaturated carboxylic acid copolymer (A1). Preferably, the continuous phase is the first ethylene-unsaturated carboxylic acid copolymer (A1) and the dispersed phase is the first acrylic polymer (B1).

[0109] Such composite particles (C1) are produced by a known method.

[0110] For example, first, a dispersion of the first ethylene-unsaturated carboxylic acid copolymer (A1) is prepared by the above method. Next, a first acrylic polymer (B1) is synthesized in the dispersion of the first ethylene-unsaturated carboxylic acid copolymer (A1). This results in a composite particle (C1) containing the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1).

[0111] More specifically, in the above method, a dispersion in which the composite particles (C1) are dispersed in water (hereinafter, sometimes referred to as C1 dispersion) is obtained.

[0112] The composite particles (C1) have an average particle size (measurement method: light scattering measurement) of, for example, 1 nm or more, preferably 10 nm or more. The composite particles (C1) have an average particle size (measurement method: light scattering measurement) of, for example, 10 μm or less, preferably 1 μm or less.

[0113] The average particle size of the composite particles (C1) observed by an electron microscope is, for example, 50 nm or more, preferably 60 nm or more, more preferably 80 nm or more. The average particle size of the composite particles (C1) observed by an electron microscope is, for example, 300 nm or less, more preferably 200 nm or less, and even more preferably 120 nm or less.

[0114] The dispersion of the composite particles (C1) (hereinafter, C1 dispersion) can be used as it is as a dispersion of the first resin component (first coating material).

[0115] If necessary, the A1 dispersion and / or the B1 dispersion may be mixed with the C1 dispersion, and the mixing ratios thereof are adjusted so that the ratio of the first ethylene-unsaturated carboxylic acid copolymer (A1) and the ratio of the first acrylic polymer (B1) are each within the above range.

[0116] As the dispersion of the first resin component (first coating material), a mixture of a dispersion of the composite particles (C1) (C1 dispersion) and a dispersion of the first ethylene-unsaturated carboxylic acid copolymer (A1) (A1 dispersion) is more preferably used.

[0117] Furthermore, the dispersion liquid of the first resin component (first coating material) can contain additives in addition to the first resin component, if necessary.

[0118] Examples of additives include known additives such as fillers, emulsifiers, curing agents, crosslinking agents, film-forming aids, defoamers, anti-repellent agents, leveling agents, tackifiers, hardness-imparting agents, preservatives, thickeners, antifreeze agents, dispersants, inorganic pigments, and organic pigments. These additives can be used alone or in combination of two or more. The mixing ratio and timing of the additives are appropriately set according to the purpose and application.

[0119] The solid content of the first resin component dispersion (first coating material) is, for example, 10% by mass or more, preferably 20% by mass or more. The solid content of the first resin component dispersion (first coating material) is, for example, 60% by mass or less, preferably 50% by mass or less.

[0120] The first resin layer 3 is, for example, a dried coating film of the above-mentioned dispersion liquid of the first resin component (first coating material). That is, the first resin layer 3 can be obtained, for example, by applying the first coating material to one surface of the substrate 2 and drying it.

[0121] The method for applying the first coating material is not particularly limited, and examples of the application method include blade coating, air knife coating, curtain coating, gravure coating, roll coating, dip coating, and spray coating.

[0122] The drying method of the first coating material is not particularly limited. Drying methods include natural drying and heat drying. The drying temperature is, for example, 20°C or higher, preferably 80°C or higher. The drying temperature is, for example, 200°C or lower, preferably 180°C or lower. The drying time is, for example, 1 second or higher, preferably 10 seconds or higher. The drying time is, for example, 1 hour or shorter, preferably 30 minutes or shorter.

[0123] As a result, the first resin layer 3 is obtained as a dried coating film of the first coating material.

[0124] The amount of the first resin layer 3 is, for example, 0.5 g / m from the viewpoints of blocking resistance, water resistance, oil resistance, and heat sealability. 2 More than 1 g / m 2 That's all.

[0125] The amount of the first resin layer 3 is, for example, 30 g / m from the viewpoints of blocking resistance, water resistance, oil resistance, and heat sealability. 2 Preferably, 14 g / m or less 2 The following is the result.

[0126] Such a first resin layer 3 is a dried coating film of the above-mentioned dispersion liquid (first coating material) of the first resin component. Therefore, the first resin layer 3 has excellent water resistance and oil resistance, and further has excellent blocking resistance and productivity.

[0127] In Fig. 1, the second resin layer 4 is laminated on one surface of the first resin layer 3. The second resin layer 4 contains a second resin component.

[0128] More specifically, the second resin layer 4 is, for example, a dried coating film of a dispersion liquid of a second resin component (hereinafter, may be referred to as a second coating material).

[0129] The second resin component contains a second ethylene-unsaturated carboxylic acid copolymer (A2).

[0130] The second ethylene-unsaturated carboxylic acid copolymer (A2) is obtained by copolymerization of the monomer component (a2) for A2. The monomer component (a2) for A2 contains ethylene and the above-mentioned unsaturated carboxylic acid.

[0131] As the unsaturated carboxylic acid, from the viewpoint of water resistance and oil resistance, preferably, an unsaturated monobasic acid is used, more preferably, acrylic acid, methacrylic acid, and salts thereof are used, and particularly preferably, methacrylic acid and salts thereof are used.

[0132] In the monomer component (a2) for A2, the unsaturated carboxylic acid may be used in combination with the vinyl esters as necessary. When the vinyl esters and the unsaturated carboxylic acid are used in combination, the ratio between them is appropriately set according to the purpose and application.

[0133] In the monomer component (a2) for A2, preferably, vinyl esters are not used in combination. More specifically, the monomer component (a2) for A2 preferably comprises ethylene and an unsaturated carboxylic acid.

[0134] In the monomer component (a2) for A2, the content ratio of ethylene and unsaturated carboxylic acid (and vinyl esters (hereinafter the same) blended as necessary) is appropriately set according to the purpose and application.

[0135] For example, the amount of ethylene is, for example, 75% by mass or more, preferably 78% by mass or more, and more preferably 80% by mass or more, based on the total amount of ethylene and the unsaturated carboxylic acid. Also, the amount of ethylene is, for example, 90% by mass or less, preferably 88% by mass or less, and more preferably 85% by mass or less, based on the total amount of ethylene and the unsaturated carboxylic acid. below It is.

[0136] For example, the content of the unsaturated carboxylic acid is, for example, 10% by mass or more, preferably 12% by mass or more, more preferably 15% by mass or more, based on the total amount of ethylene and the unsaturated carboxylic acid. For example, the content of the unsaturated carboxylic acid is, for example, 25% by mass or less, preferably 22% by mass or less, more preferably 20% by mass or less, based on the total amount of ethylene and the unsaturated carboxylic acid.

[0137] In the monomer component (a2) for A2, when the content ratio of ethylene and unsaturated carboxylic acid is within the above range, excellent water resistance and oil resistance can be obtained.

[0138] The composition of the monomer component (a2) for A2 may be the same as or different from the composition of the monomer component (a1) for A1 described above. That is, the composition of the second ethylene-unsaturated carboxylic acid copolymer (A2) may be the same as or different from the composition of the first ethylene-unsaturated carboxylic acid copolymer (A1) described above.

[0139] From the viewpoint of adhesion between the first resin layer 3 and the second resin layer 4, the composition of the second ethylene-unsaturated carboxylic acid copolymer (A2) is preferably the same as the composition of the first ethylene-unsaturated carboxylic acid copolymer (A1).

[0140] The polymerization method of the monomer component (a2) for A2 is not particularly limited, and a known polymerization method is adopted. For example, the monomer component (a2) for A2 is polymerized in water under normal pressure. In the polymerization, for example, the polymerization initiator described above is mixed in an appropriate ratio.

[0141] In the polymerization of the monomer component (a2) for A2, the above-mentioned emulsifier (surfactant) and additives are added in an appropriate ratio, if necessary.

[0142] The polymerization temperature and polymerization time of the monomer component (a2) for A2 are appropriately set depending on the type and amount of the monomer component (a2) for A2.

[0143] As a result, the second ethylene-unsaturated carboxylic acid copolymer (A2) is obtained as a polymer of the A2 monomer component (a2).

[0144] The second ethylene-unsaturated carboxylic acid copolymer (A2), like the first ethylene-unsaturated carboxylic acid copolymer (A1), is preferably neutralized and hydrated by the above-mentioned method, and further subjected to a swelling and softening treatment, from the viewpoint of dispersion stability.

[0145] Furthermore, when an unsaturated monobasic acid and / or an unsaturated dibasic acid is used as the unsaturated carboxylic acid, the unsaturated monobasic acid and / or the unsaturated dibasic acid become their salts by the above-mentioned neutralization and hydration.

[0146] The degree of neutralization of the second ethylene-unsaturated carboxylic acid copolymer (A2) is, for example, 30% or more, preferably 50% or more, and for example, 200% or less, preferably 150% or less.

[0147] The weight average molecular weight (standard polystyrene equivalent) of the second ethylene-unsaturated carboxylic acid copolymer (A2) is, for example, 10,000 or more, preferably 30,000 or more. The weight average molecular weight (standard polystyrene equivalent) of the second ethylene-unsaturated carboxylic acid copolymer (A2) is, for example, 200,000 or less, preferably 150,000 or less.

[0148] The second ethylene-unsaturated carboxylic acid copolymer (A2) has a melting point of, for example, 55°C or more, preferably 65°C or more, and for example, 110°C or less, preferably 100°C or less.

[0149] In the above method, preferably, a dispersion in which resin particles of the second ethylene-unsaturated carboxylic acid copolymer (A2) are dispersed in water is obtained.

[0150] The dispersion of the second ethylene-unsaturated carboxylic acid copolymer (A2) has a solid content concentration of, for example, 10 mass% or more, preferably 20 mass% or more. The dispersion of the second ethylene-unsaturated carboxylic acid copolymer (A2) has a solid content concentration of, for example, 60 mass% or less, preferably 50 mass% or less.

[0151] The second ethylene-unsaturated carboxylic acid copolymer (A2) has an average particle size (measurement method: light scattering measurement) of, for example, 0.01 μm or more, preferably 0.02 μm or more. The second ethylene-unsaturated carboxylic acid copolymer (A2) has an average particle size (measurement method: light scattering measurement) of, for example, 10 μm or less, preferably 1 μm or less.

[0152] The dispersion of the second ethylene-unsaturated carboxylic acid copolymer (A2) can also be obtained as a commercial product. The commercial dispersion of the second ethylene-unsaturated carboxylic acid copolymer (A2) is, for example, the same as the commercial dispersion of the first ethylene-unsaturated carboxylic acid copolymer (A1) described above. These can be used alone or in combination of two or more kinds.

[0153] Such a second ethylene-unsaturated carboxylic acid copolymer (A2) improves the water resistance and oil resistance of the second resin layer 4. In addition, the second ethylene-unsaturated carboxylic acid copolymer (A2) improves the blocking resistance of the second resin layer 4. In addition, the second ethylene-unsaturated carboxylic acid copolymer (A2) improves the heat seal property of the laminate 1 including the first resin layer 3 and the second resin layer 4.

[0154] The second resin component may further contain other resins, so long as it contains the second ethylene-unsaturated carboxylic acid copolymer (A2).

[0155] An example of the other resin is a second acrylic polymer (B2).

[0156] The second acrylic polymer (B2) is obtained by polymerization of a monomer component (b2) for B2. The monomer component (b2) for B2 contains, for example, the above-mentioned (meth)acrylic acid ester. The monomer component (b2) for B2 can also contain the above-mentioned copolymerizable monomer in an appropriate ratio, if necessary.

[0157] For example, the (meth)acrylic acid ester is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more, based on the total amount of the (meth)acrylic acid ester and the copolymerizable monomer. Also, the (meth)acrylic acid ester is, for example, 90% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on the total amount of the (meth)acrylic acid ester and the copolymerizable monomer. % The following is the result.

[0158] In addition, the copolymerizable monomer is, for example, 10 mass% or more, preferably 20 mass% or more, more preferably 30 mass% or more, and still more preferably 40 mass% or more, based on the total amount of the (meth)acrylic acid ester and the copolymerizable monomer. % In addition, the amount of the copolymerizable monomer relative to the total amount of the (meth)acrylic acid ester and the copolymerizable monomer is, for example, 90% by mass or less, preferably 80% by mass or less, more preferably 70% by mass or less, further preferably 60% by mass or less, and particularly preferably 50% by mass or less.

[0159] In the monomer component for B2, the copolymerizable monomer is preferably selected depending on the form of the second acrylic polymer (B2).

[0160] For example, when the second ethylene-unsaturated carboxylic acid copolymer (A2) and the second acrylic polymer (B2) do not form composite particles (C2) described below, but the second acrylic polymer (B2) forms independent resin particles, the copolymerizable monomer preferably contains a functional group-containing vinyl monomer and an aromatic vinyl monomer.

[0161] In such a case, the ratio of the functional group-containing vinyl monomer to the total amount of copolymerizable monomers in the monomer component for B2 is, for example, the same as the ratio of the functional group-containing vinyl monomer to the total amount of copolymerizable monomers in the monomer component for B1 described above.

[0162] Furthermore, for example, when the second ethylene-unsaturated carboxylic acid copolymer (A2) and the second acrylic polymer (B2) form the composite particle (C2) described below, the copolymerizable monomer preferably does not contain a functional group-containing vinyl monomer, and more preferably, the aromatic vinyl monomer is, for example, 100 mass% based on the total amount of the copolymerizable monomers.

[0163] The composition of the monomer component (b2) for B2 may be the same as or different from the composition of the monomer component (b1) for B1 described above. That is, the composition of the second acrylic polymer (B2) may be the same as or different from the composition of the first acrylic polymer (B1) described above.

[0164] From the viewpoint of adhesion between the first resin layer 3 and the second resin layer 4, the composition of the second acrylic polymer (B2) is preferably the same as the composition of the first acrylic polymer (B1).

[0165] Moreover, the other resins are not limited to the second acrylic resin (B2), but may also include the binder resins described above.

[0166] The proportion of other resins (including the second acrylic resin (B2)) relative to the total amount of the second resin component is 5 mass% or less, preferably 3 mass% or less, more preferably 1 mass% or less, and particularly preferably 0 mass%.

[0167] That is, the proportion of the second ethylene-unsaturated carboxylic acid copolymer (A2) is 95 mass % or more, preferably 97 mass % or more, and more preferably 99 mass % or more, based on the total amount of the second resin component.

[0168] When the proportion of the second ethylene-unsaturated carboxylic acid copolymer (A2) is above the above lower limit, the second resin layer 4 has excellent blocking resistance, water resistance, oil resistance and heat sealability.

[0169] From the viewpoints of blocking resistance, water resistance, oil resistance and heat sealability, the proportion of the second ethylene-unsaturated carboxylic acid copolymer (A2) is particularly preferably 100 mass % based on the total amount of the second resin component.

[0170] In other words, the second resin component particularly preferably does not contain other resins (including the second acrylic resin (B2)) and consists of the second ethylene-unsaturated carboxylic acid copolymer (A2).

[0171] In the second resin component, the form of the second ethylene-unsaturated carboxylic acid copolymer (A2) and the form of other resins (including the second acrylic resin (B2)) that are blended as necessary are not particularly limited.

[0172] For example, the second resin component may contain only resin particles made of the second ethylene-unsaturated carboxylic acid copolymer (A2).

[0173] In such a case, the dispersion of the second resin component (second coating material) is prepared by a known method. For example, first, the A2 monomer component (a2) is polymerized by the above-mentioned method. This results in a dispersion of resin particles consisting of the second ethylene-unsaturated carboxylic acid copolymer (A2) (hereinafter, A2 dispersion).

[0174] The dispersion of the second ethylene-unsaturated carboxylic acid copolymer (A2) (hereinafter sometimes referred to as A2 dispersion) can be used as it is as a dispersion of the second resin component (second coating material).

[0175] Similarly to the above-mentioned first coating material, the second coating material may be a mixture of a dispersion of a second ethylene-unsaturated carboxylic acid copolymer (A2) and a mixture of a second acrylic polymer (B2) (hereinafter sometimes referred to as B2 dispersion).

[0176] In such a case, the B1 monomer component (b1) is polymerized by the above-mentioned method separately from the A2 dispersion liquid, thereby obtaining a dispersion liquid of resin particles composed solely of the first acrylic polymer (B1) (hereinafter, sometimes referred to as B1 dispersion liquid).

[0177] Then, the A2 dispersion and the B2 dispersion are mixed so that the ratio of the second ethylene-unsaturated carboxylic acid copolymer (A2) and the ratio of the second acrylic polymer (B2) are within the above ranges.

[0178] As a result, a dispersion of the second resin component (second coating material) is obtained as a mixture of the dispersion of the second ethylene-unsaturated carboxylic acid copolymer (A2) and the second acrylic polymer (B2).

[0179] Also, the second ethylene-unsaturated carboxylic acid copolymer (A2) and the second acrylic polymer (B2) can form composite particles (C2).

[0180] That is, the second resin component can contain composite particles (C2) containing a second ethylene-unsaturated carboxylic acid copolymer (A2) and a second acrylic polymer (B2).

[0181] The composite particle (C2) contains, for example, a second ethylene-unsaturated carboxylic acid copolymer (A2) and a second acrylic polymer (B2), and is preferably composed of the second ethylene-unsaturated carboxylic acid copolymer (A2) and the second acrylic polymer (B2).

[0182] The structure of the composite particle (C2) is not particularly limited, and may be the same as that of the composite particle (C1) described above. The composite particle (C2) is produced by the same method as that of the composite particle (C1).

[0183] The dispersion in which the composite particles (C2) are dispersed in water (hereinafter, may be referred to as C2 dispersion) can be used as it is as a dispersion of the second resin component (second coating material).

[0184] If necessary, the A2 dispersion may be mixed with the B1 dispersion and / or the C1 dispersion, and the mixing ratios thereof are adjusted so that the ratio of the second ethylene-unsaturated carboxylic acid copolymer (A2) and the ratio of the second acrylic polymer (B2) are each within the above range.

[0185] As the dispersion of the second resin component (second coating material), a dispersion of resin particles of the second ethylene-unsaturated carboxylic acid copolymer (A2) alone (A2 dispersion) is preferably used.

[0186] The dispersion of the second resin component (second coating material) may contain the above-mentioned additives as necessary. The mixing ratio and timing of the additives are appropriately set according to the purpose and application.

[0187] The solid content of the second resin component dispersion (second coating material) is, for example, 10% by mass or more, preferably 20% by mass or more. The solid content of the second resin component dispersion (second coating material) is, for example, 60% by mass or less, preferably 50% by mass or less.

[0188] The second resin layer 4 is, for example, a dried coating film of the above-mentioned dispersion liquid of the second resin component (second coating material). That is, the second resin layer 4 can be obtained, for example, by applying the second coating material to one surface of the first resin layer 3 and drying it.

[0189] The second coating material can be applied by the above-mentioned coating methods.

[0190] The second coating material may be applied, for example, to a dried coating film of the first resin component. Also, the second coating material may be applied to a coating film of the first resin component before drying (wet coating film).

[0191] The drying method of the second coating material is not particularly limited. Drying methods include natural drying and heat drying. The drying temperature is, for example, 20°C or higher, preferably 80°C or higher. The drying temperature is, for example, 200°C or lower, preferably 180°C or lower. The drying time is, for example, 1 second or higher, preferably 10 seconds or higher. The drying time is, for example, 1 hour or shorter, preferably 30 minutes or shorter.

[0192] As a result, the second resin layer 4 is obtained as a dried coating film of the second coating material.

[0193] The amount of the second resin layer 4 is, for example, 0.5 g / m from the viewpoints of blocking resistance, water resistance, oil resistance and heat sealability. 2 More than 1 g / m 2 That's all.

[0194] The amount of the second resin layer 4 is, for example, 30 g / m from the viewpoints of blocking resistance, water resistance, oil resistance, and heat sealability. 2 Preferably, 14 g / m or less 2 The following is the result.

[0195] Such a second resin layer 4 is a dried coating film of the above-mentioned dispersion liquid of the second resin component, and therefore the second resin layer 4 has particularly excellent blocking resistance and heat sealability.

[0196] The second coating material may be applied together with the first coating material, and in this case, the coating method may be, for example, a curtain coating method.

[0197] When the first coating material and the second coating material are applied at the same time, the first coating material and the second coating material are dried at the same time. In such a case, the drying method includes natural drying and heat drying. The drying temperature is, for example, 20° C. or higher, preferably 80° C. or higher. The drying temperature is, for example, 200° C. or lower, preferably 180° C. or lower. The drying time is, for example, 1 second or higher, preferably 10 seconds or higher. The drying time is, for example, 1 hour or shorter, preferably 30 minutes or shorter.

[0198] As a result, a first resin layer 3 is obtained as a dried film of the first coating material. At the same time, a second resin layer 4 is obtained as a dried film of the second coating material.

[0199] The total amount of the first resin layer 3 and the second resin layer 4 is, for example, 1 g / m2 from the viewpoints of blocking resistance, water resistance, oil resistance, and heat sealability. 2 More than 2 g / m 2 That's all.

[0200] The total amount of the first resin layer 3 and the second resin layer 4 is, for example, 30 g / m 2 in terms of blocking resistance, water resistance, oil resistance, and heat sealability. 2 Preferably, 15 g / m or less 2 The following is the result.

[0201] In this manner, a laminate 1 including the substrate 2, the first resin layer 3 and the second resin layer 4 is obtained.

[0202] The laminate 1 has a total thickness of, for example, 0.1 μm or more, or preferably 1 μm or more. The laminate 1 has a total thickness of, for example, 1500 μm or less, or preferably 1000 μm or less.

[0203] Such a laminate 1 includes a substrate 2, a first resin layer 3 containing a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1), and a second resin layer 4 containing a second ethylene-unsaturated carboxylic acid copolymer (A2). In the first resin layer 3, the proportion of the ethylene-unsaturated carboxylic acid copolymer (A1) is adjusted to a predetermined range. In the first resin layer 3, the glass transition temperature of the first acrylic polymer (B1) is adjusted to a predetermined range. In the second resin layer 4, the proportion of the second ethylene-unsaturated carboxylic acid copolymer (A2) is a predetermined value or more.

[0204] In such a laminate 1, the second resin layer 4 has excellent blocking resistance. Therefore, the laminate 1 has blocking resistance. In addition, the first resin layer 3 has excellent water resistance and oil resistance. Therefore, the laminate 1 has excellent water resistance and oil resistance.

[0205] More specifically, in the laminate 1, blocking resistance is a property required for a layer disposed on the outer side (preferably the outermost surface), whereas water resistance and oil resistance are properties required for a layer disposed on the inner side.

[0206] Therefore, in the laminate 1, the second resin layer 4 having particularly excellent blocking resistance is disposed on the outer side. Furthermore, in the laminate 1, the first resin layer 3 having particularly excellent water resistance and oil resistance is disposed on the inner side.

[0207] As a result, the laminate 1 has excellent blocking resistance on the outer side, and excellent water resistance and oil resistance on the inner side.

[0208] Furthermore, the first resin layer 3 has excellent blocking resistance. Therefore, even if the second resin layer 4 is not disposed, the transport efficiency of the substrate 2 and the first resin layer 3 is excellent, and the lamination efficiency of the second resin layer 4 is excellent. As a result, the production efficiency of the laminate 1 is improved.

[0209] In addition, since the second resin layer 4 is disposed on one side of the first resin layer 3, the laminate 1 has excellent heat seal properties.

[0210] As a result, the laminate 1 has excellent blocking resistance, water resistance, oil resistance, heat sealability and production efficiency.

[0211] In the above description, the first resin layer 3 is disposed directly on one surface of the substrate 2. However, the first resin layer 3 does not have to be disposed directly on the surface of the substrate 2. That is, an intermediate layer may be interposed between the substrate 2 and the first resin layer 3. Examples of the intermediate layer include an undercoat layer and a primer layer.

[0212] In the above description, the second resin layer 4 is disposed directly on one surface of the first resin layer 3. However, the second resin layer 4 does not have to be disposed directly on the surface of the first resin layer 3. In other words, an intermediate layer may be interposed between the first resin layer 3 and the second resin layer 4. Examples of the intermediate layer include an undercoat layer and a primer layer.

[0213] Moreover, the first resin layer 3 and the second resin layer 4 may be disposed on at least one side of the base material 2. In other words, the first resin layer 3 and / or the second resin layer 4 may be disposed on the other side of the base material 2 relative to one side.

[0214] The laminate 1 described above is suitable for use as a packaging material in various industrial fields.

[0215] The packaged item to be packaged by the laminate 1 is not particularly limited. Examples of the packaged item include food, aromatic substances, and industrial products. Examples of the food include confectionery, tea leaves, and spices. Examples of the aromatic substances include tobacco and fragrant wood. Examples of the industrial products include medicines and paper. EXAMPLES

[0216] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited thereto. Note that the specific numerical values ​​of the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numerical values ​​defined as "equal to or less than") or lower limit values ​​(numerical values ​​defined as "equal to or more than" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention".

[0217] (1) First coating material Preparation example 1 (A1 dispersion) Chemipearl S100 (ethylene content in raw material: 85% by mass, type of unsaturated carboxylic acid: methacrylic acid, neutralized with sodium hydroxide, solid content 27%, manufactured by Mitsui Chemicals) was prepared as the first ethylene-unsaturated carboxylic acid copolymer (A1). Thus, an A1 dispersion was obtained.

[0218] Preparation example 2 (B1 dispersion) 44.5 parts by mass of styrene, 52.5 parts by mass of n-butyl acrylate, 3 parts by mass of methacrylic acid, and 0.2 parts by mass of n-dodecyl mercaptan (molecular weight regulator) were emulsified in 40 parts by mass of deionized water with 0.4 parts by mass of sodium dodecylbenzenesulfonate (emulsifier), and the resulting emulsion mixture was dropped into a reaction vessel over 2 hours, and then maintained at 80°C for 2 hours to complete the polymerization. This produced a first acrylic polymer (B1). This gave a B1 dispersion.

[0219] Preparation example 3 (C1 dispersion) 200 parts by mass of Chemipearl S100 (ethylene content in raw material: 85% by mass, type of unsaturated carboxylic acid: methacrylic acid, neutralized with sodium hydroxide, solids content 27%, manufactured by Mitsui Chemicals) as the first ethylene-unsaturated carboxylic acid copolymer (A1) and 27 parts by mass of deionized water were charged into a reaction vessel and heated to 80°C under a nitrogen stream, and 0.3 parts by mass of potassium persulfate was added.

[0220] Separately, 48.2 parts by mass of styrene, 51.8 parts by mass of n-butyl acrylate, and 0.2 parts by mass of n-dodecyl mercaptan (molecular weight regulator) were emulsified in 40 parts by mass of deionized water with 0.4 parts by mass of sodium dodecylbenzenesulfonate (emulsifier), and the resulting emulsion mixture was dropped into a reaction vessel over 2 hours, and then maintained at 80° C. for 2 hours to complete the polymerization. This resulted in the formation of a first acrylic polymer (B1) and a dispersion of composite particles (C1).

[0221] A part of the obtained aqueous dispersion was dried and the solid particles were observed under an electron microscope. As a result, composite particles (C1) having a particle diameter of 80 to 120 nm and a structure in which the first acrylic polymer (B1) was dispersed in a continuous phase of the first ethylene-unsaturated carboxylic acid copolymer (A1) were observed.

[0222] (2) Second coating material Preparation example 4 (A2 dispersion) Chemipearl S100 (ethylene content in raw material: 85% by mass, type of unsaturated carboxylic acid: methacrylic acid, neutralized with sodium hydroxide, solid content 27%, manufactured by Mitsui Chemicals) was prepared as the second ethylene-unsaturated carboxylic acid copolymer (A2). Thus, an A2 dispersion was obtained. Preparation example 5 (B2 dispersion) 44.5 parts by mass of styrene, 52.5 parts by mass of n-butyl acrylate, 3 parts by mass of methacrylic acid, and 0.2 parts by mass of n-dodecyl mercaptan (molecular weight regulator) were emulsified in 40 parts by mass of deionized water with 0.4 parts by mass of sodium dodecylbenzenesulfonate (emulsifier), and the resulting emulsified mixture was dropped into a reaction vessel over a period of 2 hours, and then the mixture was kept at 80° C. for 2 hours to complete the polymerization. 2 Acrylic polymer (B 2 ) was formed. This resulted in a B2 dispersion.

[0223] Preparation example 6 (C2 dispersion) 200 parts by mass of Chemipearl S100 (ethylene content in raw material: 85% by mass, type of unsaturated carboxylic acid: methacrylic acid, neutralized with sodium hydroxide, solids content 27%, manufactured by Mitsui Chemicals) as the second ethylene-unsaturated carboxylic acid copolymer (A2) and 27 parts by mass of deionized water were charged into a reaction vessel and heated to 80°C under a nitrogen stream, and 0.3 parts by mass of potassium persulfate was added.

[0224] Separately, 48.2 parts by mass of styrene, 51.8 parts by mass of n-butyl acrylate, and 0.2 parts by mass of n-dodecyl mercaptan (molecular weight regulator) were emulsified in 40 parts by mass of deionized water with 0.4 parts by mass of sodium dodecylbenzenesulfonate (emulsifier), and the resulting emulsion mixture was dropped into a reaction vessel over 2 hours, and then maintained at 80° C. for 2 hours to complete the polymerization. This resulted in the formation of a second acrylic polymer (B2) and a dispersion of composite particles (C2).

[0225] A part of the obtained aqueous dispersion was dried and the solid particles were observed under an electron microscope. As a result, composite particles (C2) having a particle diameter of 80 to 120 nm and a structure in which the second acrylic polymer (B2) was dispersed in a continuous phase of the second ethylene-unsaturated carboxylic acid copolymer (A2) were observed.

[0226] Examples 1 to 12 and Comparative Examples 1 to 8 (1) Base material Cup base paper as a substrate (Tokyo Paper, 200g / m 2 The substrate was then left to stand at 23° C. and 50% relative humidity for 24 hours to condition the moisture.

[0227] (2) First coating material Dispersion liquid A1, dispersion liquid B1, and dispersion liquid C1 were selected as shown in Tables 1 to 5. When two or more types of dispersion liquid were selected, these dispersion liquids were mixed. In this way, a first coating material was obtained.

[0228] Then, the first coating material was applied to the substrate using a bar coater (No. 4), thereby obtaining a wet coating film of the first coating material.

[0229] (3) Second coating material Dispersion liquid A2, dispersion liquid B2, and dispersion liquid C2 were selected as shown in Tables 1 to 5. When two or more types of dispersion liquid were selected, these dispersion liquids were mixed together. In this way, a second coating material was obtained.

[0230] Then, the second coating material was applied to the wet coating film of the first coating material using a bar coater (No. 5). This resulted in a wet coating film of the second coating material. As a result, a laminate including the substrate, the wet coating film of the first coating material, and the wet coating film of the second coating material was obtained.

[0231] (4) Drying A laminate including the substrate, the wet coating film of the first coating material, and the wet coating film of the second coating material was heated at 120° C. for 15 seconds.

[0232] This resulted in a first resin layer being obtained as a dry coating film of the first coating material, and a second resin layer being obtained as a dry coating film of the second coating material, resulting in a laminate including the substrate, the first resin layer, and the second resin layer.

[0233] <Evaluation> (1) Blocking resistance of the first resin layer Cup base paper as a substrate (Tokyo Paper, 200g / m 2 The substrate was then left to stand at 23° C. and 50% relative humidity for 24 hours to condition the moisture.

[0234] Next, the A1 dispersion, the B1 dispersion, and the C1 dispersion were selected as shown in Tables 1 to 5. When two or more types of dispersions were selected, these dispersions were mixed together. In this way, a first coating material was obtained.

[0235] The first coating material was then applied to the substrate using a bar coater (No. 4). This resulted in a wet coating film of the first coating material. This resulted in a laminate including the substrate and the wet coating film of the first coating material.

[0236] Thereafter, the laminate comprising the substrate and the wet coating film of the first coating material was heated at 120° C. for 15 seconds.

[0237] This resulted in a first resin layer being obtained as a dried coating film of the first coating material, resulting in a laminate including the substrate and the first resin layer.

[0238] The laminate obtained above was cut into a square of 5 cm length and width, and the first resin layers were overlapped on each other and pressed (0.5 kg / cm) at 40° C. for 10 seconds. 2 The first resin layers were then peeled away from each other with tweezers, and the blocking resistance was evaluated. The evaluation criteria are as follows.

[0239] ◯: The overlapping first resin layers were separated without resistance. Δ: Sticking was observed in part of the first resin layer. ×: Sticking was observed over the entire surface of the first resin layer.

[0240] (2) Blocking resistance of the second resin layer

[0241] The laminate comprising the substrate, the first resin layer, and the second resin layer was cut into a square measuring 5 cm in length and width, and the second resin layers were placed one on top of the other and pressed (0.5 kg / cm) at 40° C. for 10 seconds. 2 The second resin layers were then peeled away from each other with tweezers, and the blocking resistance was evaluated. The evaluation criteria are as follows.

[0242] ◯: The overlapping second resin layers were separated without resistance. Δ: Sticking was observed in part of the second resin layer. ×: Sticking was observed over the entire surface of the second resin layer.

[0243] (3) Oil resistance In the above laminate including the substrate, the first resin layer, and the second resin layer, the oil resistance of the second resin layer was evaluated by the kit method. The evaluation method was in accordance with the JAPAN TAPPI paper pulp test method (No. 41). The evaluation criteria are as follows.

[0244] ○: Kit value 6~10. △: Kit value 3~5. ×: Kit value 0~2.

[0245] (4) Water resistance In the above laminate including the substrate, the first resin layer, and the second resin layer, the water resistance of the second resin layer was evaluated by the Cobb method. The evaluation method was in accordance with ISO 535 (1991). The evaluation criteria are as follows.

[0246] ○: Cobb value less than 3.0. △: Cobb value 3.0 or more and less than 5.0. ×: Cobb value 5.0 or higher.

[0247] (5) Heat seal properties Two of the above laminates including a substrate, a first resin layer, and a second resin layer were prepared. The two laminates were then placed so that the second resin layers were in contact with each other, and heat-sealed. The heat-sealing temperature was 140°C, the heat-sealing time was 1.0 second, and the heat-sealing pressure was 2 kg / cm. 2 It was.

[0248] Thereafter, the peel strength of the heat-sealed portion was measured in T-mode (50 mm / min) using a tensile strength tester (manufactured by Shimadzu Corporation). The evaluation criteria are as follows.

[0249] ○: Peel strength is 500g / 15mm or more. ×: Peel strength less than 500g / 15mm.

[0250] [Table 1]

[0251] [Table 2]

[0252] [Table 3]

[0253] [Table 4]

[0254] [Table 5]

[0255] Details of the abbreviations in the table are given below. MAc: methacrylic acid MacNa: Sodium methacrylate ST: styrene nBA: n-butyl acrylate A1: First ethylene-unsaturated carboxylic acid copolymer (A1) A2: Second ethylene-unsaturated carboxylic acid copolymer (A2) B1: First acrylic polymer (B1) B2: Second acrylic polymer (B2) C1: Composite particle (C1) C2: Composite particle (C2)

[0256] The above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be interpreted as being limited. Modifications of the present invention that are obvious to those skilled in the art are included in the scope of the following claims. [Industrial Applicability]

[0257] The laminate of the present invention is suitably used in the field of packaging materials. [Explanation of symbols]

[0258] 1. Laminate 2 Base material 3 First resin layer 4 Second resin layer

Claims

1. A substrate; a first resin layer disposed on at least one side of the substrate and including a first resin component; a second resin layer disposed on the one side of the first resin layer and including a second resin component; Equipped with the first resin component includes a first ethylene-unsaturated carboxylic acid copolymer (A1) and a first acrylic polymer (B1); a ratio of the first ethylene-unsaturated carboxylic acid copolymer (A1) to the total amount of the first resin component is 25% by mass or more and 90% by mass or less; The glass transition temperature of the first acrylic polymer (B1) is −30° C. or more and 15° C. or less, The second resin component contains a second ethylene-unsaturated carboxylic acid copolymer (A2), A laminate, wherein a proportion of the second ethylene-unsaturated carboxylic acid copolymer (A2) is 95 mass% or more relative to the total amount of the second resin component.

2. The first resin component is The laminate according to claim 1 , comprising composite particles (C1) containing the first ethylene-unsaturated carboxylic acid copolymer (A1) and the first acrylic polymer (B1).

3. The amount of the first resin layer is 1 g / m ２ 14g / m or more ２ is as follows: The amount of the second resin layer is 1 g / m ２ 14g / m or more ２ is as follows: The total amount of the first resin layer and the second resin layer is 2 g / m ２ 15g / m or more ２ 2. The laminate of claim 1, wherein:

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