Multilayer structure and interior material

Abstract

To provide a multilayer structure that is equipped with a layer containing an aqueous emulsion-based adhesive, but offers blocking resistance and maintains peeling strength at a relatively high temperature (around 40°C).SOLUTION: A multilayer structure comprises: (A) a layer composed of a resin composition containing an ethylene-vinyl alcohol copolymer (a1); (B) an anchor coat layer; and (C) an adhesive layer composed of a composition containing an aqueous emulsion-based adhesive (c1), where the aqueous emulsion-based adhesive (c1) satisfies specific conditions.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a multi-layer structure and an interior material. [Background technology]

[0002] In recent years, resin moldings mainly made of polyvinyl chloride resin layers have been widely used as interior materials for buildings. However, wallpapers containing these polyvinyl chloride resin layers and decorative panels (hereinafter sometimes abbreviated as wallpapers) used for ceiling materials, wall materials, floor materials, furniture, etc. in ordinary homes, hospitals, clinics, restaurants, factories, ships, trains, automobiles, etc. are easily contaminated by cigarette smoke, fingerprints, graffiti, various food colorings, etc. In addition, the plasticizer for polyvinyl chloride resin bleeds out onto the surface of the wallpaper, and dust adheres to the bleed-out plasticizer, making the wallpapers containing the polyvinyl chloride resin layer even more susceptible to contamination. On the other hand, wallpapers mainly made of polyolefin resins, which have recently begun to be used, have less problems with plasticizer bleeding out, but are similarly easily contaminated by the above-mentioned various types of dirt.

[0003] To address this problem, a technique is known in which a film made of an ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) or an EVOH composition is laminated onto the surface of wallpaper to improve stain resistance. For example, Patent Document 1 describes that by using a multilayer film having a composition layer containing a vinyl alcohol-based polymer resin composition and an inorganic antibacterial agent, and an adhesive layer containing an aqueous emulsion-based adhesive and an oxidizing agent, it is possible to provide a multilayer film that has a stain-preventing function and adhesive strength while having a substantially zero VOC content. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-282834 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the case of the above-mentioned conventional multilayer films, blocking may become a problem when the multilayer film is wound into a roll. Also, it has been found that wallpaper obtained using the above-mentioned conventional multilayer films may not be able to maintain a high peel strength between the wallpaper and the adhesive layer when exposed to a relatively high temperature environment (such as 40°C).

[0006] The present invention has been made to solve the above-mentioned problems, and can provide a multilayer structure and an interior material that have blocking resistance and can maintain peel strength even in a relatively high temperature (about 40°C) environment, even if the multilayer structure has a layer containing an aqueous emulsion-based adhesive. [Means for solving the problem]

[0007] The above purpose is [1] A multilayer structure comprising a layer (A) made of a resin composition containing an ethylene-vinyl alcohol copolymer (a1) (hereinafter sometimes abbreviated as "EVOH (a1)"), an anchor coat layer (B), and an adhesive layer (C) made of a composition containing an aqueous emulsion-based adhesive (c1), wherein the aqueous emulsion-based adhesive (c1) satisfies the following condition (1): [Condition (1): 100 parts by mass of the aqueous emulsion adhesive (c1) and 82.9 parts by mass of a urethane prepolymer with a nonionic terminal isocyanate, which is a urethane curing agent, were mixed and stirred at 23°C for 10 minutes to prepare a coating liquid. The coating liquid was applied onto an EVOH layer (ethylene unit content 44 mol%, saponification degree 99.5 mol%, MFR (190°C, under a load of 2160 g) 5 g / 10 min, thickness 12 μm) so that the thickness after drying would be 0.2 μm, and the coating liquid was dried at 60°C for 5 minutes to prepare an EVOH layer. After forming a coating liquid layer on the layer, a water-based emulsion adhesive (c1) is applied onto the coating liquid layer so that the thickness after drying is 2 μm, and an adhesive layer is formed by drying at 60°C for 5 minutes, and a non-foamed polyvinyl chloride wallpaper substrate is laminated onto the adhesive layer, and after heat sealing under conditions of a pressure of 0.1 MPa, a temperature of 130°C, and a heating time of 1 second using a thermal gradient sheet seal tester, the interlayer peel strength between the EVOH layer and the coating liquid layer, measured in accordance with JIS K6854-3 (1999), is 1 N / 15 mm or less.]; [2] The multilayer structure according to claim 1, wherein the layer (A) comprises a modified polyolefin (a2); [3] The multilayer structure of [2], wherein the modified polyolefin (a2) is a maleic anhydride modified polyolefin; [4] The multilayer structure of [2] or [3], wherein the mass ratio (a1) / (a2) of the EVOH (a1) to the modified polyolefin (a2) in the layer (A) is 40 / 60 to 95 / 5; [5] An interior material comprising the multilayer structure of any one of [1] to [4] and a substrate (D); This is achieved by providing Effect of the Invention

[0008] The multilayer structure and interior material of the present invention, even if it is a multilayer structure having a layer containing an aqueous emulsion-based adhesive, has blocking resistance and can maintain peel strength even in a relatively high temperature (about 40°C) environment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The multilayer structure of the present invention comprises a layer (A) made of a resin composition containing EVOH (a1), an anchor coat layer (B), and an adhesive layer (C) made of a composition containing an aqueous emulsion adhesive (c1), and the aqueous emulsion adhesive (c1) satisfies the following condition (1): [Condition (1): 100 parts by mass of the aqueous emulsion adhesive (c1) and 82.9 parts by mass of a urethane prepolymer with a nonionic terminal isocyanate, which is a urethane curing agent, are mixed and stirred at 23°C for 10 minutes to prepare a coating liquid, and the coating liquid is applied onto an EVOH layer (ethylene unit content 44 mol%, saponification degree 99.5 mol%, MFR (190°C, under a load of 2160 g) 5 g / 10 minutes, thickness 12 μm) so that the thickness after drying is 0.2 μm, and the coating liquid is dried at 60°C for 5 minutes to prepare an EVOH coating liquid. After forming a coating liquid layer on the layer, a water-based emulsion adhesive (c1) is applied onto the coating liquid layer so that the thickness after drying is 2 μm, and an adhesive layer is formed by drying at 60°C for 5 minutes. A non-foamed polyvinyl chloride wallpaper base material is laminated onto the adhesive layer, and heat-sealed using a thermal gradient sheet seal tester under conditions of a pressure of 0.1 MPa, a temperature of 130°C, and a heating time of 1 second. The interlayer peel strength between the EVOH layer and the coating liquid layer, measured in accordance with JIS K6854-3 (1999), is 1 N / 15 mm or less.]

[0010] By providing the multilayer structure of the present invention with layer (A), various properties required for wallpaper, such as stain prevention function, surface strengthening function, chemical resistance, and non-adsorption of odors, tend to be improved. In addition, by providing the multilayer structure of the present invention with anchor coat layer (B), peel strength tends to be improved. In addition, by providing the multilayer structure of the present invention with adhesive layer (C), blocking resistance is improved and peel strength tends to be maintained even in a relatively high temperature (about 40°C) environment. The factors for the aqueous emulsion adhesive (c1) to satisfy condition 1 will be described later, but it is particularly important that the aqueous emulsion adhesive (c1) has a low content of "functional groups that are highly reactive with isocyanate groups."

[0011] In this specification, " / " and " / / " may be used to indicate a layer structure, where " / " means that the layers are directly laminated and " / / " means that the layers are laminated directly or via an adhesive layer.

[0012] (Layer(A)) The multilayer structure of the present invention comprises a layer (A) made of a resin composition containing EVOH (a1). By providing the multilayer structure of the present invention with the layer (A), various properties required for wallpaper, such as stain prevention function, surface strengthening function, chemical resistance, and non-adsorption of odors, tend to be improved. EVOH (a1) is a copolymer having an ethylene unit and a vinyl alcohol unit, and is obtained, for example, by saponifying a copolymer containing ethylene and a vinyl ester using an alkali catalyst or the like. A representative vinyl ester is vinyl acetate, but other fatty acid vinyl esters (vinyl formate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, vinyl versatate, etc.) can also be used.

[0013] The lower limit of the ethylene unit content of EVOH (a1) is preferably 20 mol%, more preferably 23 mol%, and even more preferably 25 mol%. The upper limit of the ethylene unit content of EVOH (a1) is preferably 60 mol%, more preferably 55 mol%, and even more preferably 50 mol%. When the ethylene unit content is equal to or more than the lower limit, the water resistance of the layer (A) tends to be improved. Conversely, when the ethylene unit content is equal to or less than the upper limit, the stain prevention function of the layer (A) tends to be improved. The ethylene unit content of EVOH (a1) is 1 It can be determined by H-NMR measurement.

[0014] The lower limit of the saponification degree of EVOH (a1) is preferably 90 mol%, more preferably 95 mol%, and even more preferably 99 mol%. When the saponification degree of EVOH (a1) is equal to or higher than the lower limit, the stain prevention function of the layer (A) is improved. The saponification degree means the ratio of the number of vinyl alcohol units to the total number of vinyl alcohol units and vinyl ester units in EVOH (a1). The upper limit of the saponification degree may be 99.99 mol%. The saponification degree of EVOH (a1) is 1 It can be determined by H-NMR measurement.

[0015] EVOH (a1) may contain other monomer units other than ethylene, vinyl ester and vinyl alcohol, so long as the effects of the present invention are not impaired. In particular, by introducing a modifying group containing a primary hydroxyl group having a specific structure, the gas barrier property and moldability of EVOH (a1) may be compatible at a high level. The content of other monomer units is preferably 10 mol% or less, more preferably 5 mol% or less, even more preferably 1 mol% or less, and particularly preferably substantially not contained. Examples of such other monomers include alkenes such as propylene, butylene, pentene, and hexene; 3-acyloxy-1-propene, 3-acyloxy-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-methyl-1-butene, 4-acyloxy-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-methyl -1-butene, 4-acyloxy-2-methyl-1-butene, 4-acyloxy-3-methyl-1-butene, 3,4-diacyloxy-2-methyl-1-butene, 4-acyloxy-1-pentene, 5-acyloxy-1-pentene, 4,5-diacyloxy-1-pentene, 4-acyloxy-1-hexene, 5-acyloxy-1-hexene, 6-acyloxy-1-hexene, 5,6-diacyloxy ester group-containing alkenes or saponification products thereof, such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, or other unsaturated acids or their anhydrides, salts, or mono- or dialkyl esters; nitriles such as acrylonitrile and methacrylonitrile; amides such as acrylamide and methacrylamide; olefin sulfonic acids or salts thereof, such as vinyl sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid; vinyl silane compounds such as vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tri(β-methoxy-ethoxy) silane, and γ-methacryloxypropyl methoxy silane; alkyl vinyl ethers, vinyl ketones, N-vinyl pyrrolidone, vinyl chloride, and vinylidene chloride.

[0016] EVOH (a1) may be modified as necessary by urethanization, acetalization, cyanoethylation, oxyalkylenation, etc. Oxyalkylenation can be carried out using an epoxy compound, such as epoxyethane (ethylene oxide), epoxypropane, 1,2-epoxybutane, 2,3-epoxybutane, 3-methyl-1,2-epoxybutane, 1,2-epoxypentane, 3-methyl-1,2-epoxypentane, 1,2-epoxyhexane, 2,3-epoxyhexane, 3,4-epoxyhexane, 3-methyl-1,2-epoxyhexane, 3-methyl-1,2-epoxyheptane, 4-methyl-1,2-epoxyheptane, 1, Examples of such epoxy alkanols include 2-epoxyoctane, 2,3-epoxyoctane, 1,2-epoxynonane, 2,3-epoxynonane, 1,2-epoxydecane, 1,2-epoxydodecane, epoxyethylbenzene, 1-phenyl-1,2-propane, 3-phenyl-1,2-epoxypropane, various alkyl glycidyl ethers, various alkylene glycol monoglycidyl ethers, various alkenyl glycidyl ethers, various epoxy alkanols such as glycidol, various epoxy cycloalkanes, and various epoxy cycloalkenes. Among these, 1,2-epoxybutane, 2,3-epoxybutane, epoxypropane, epoxyethane, or glycidol is preferred, and epoxypropane or glycidol is more preferred.

[0017] The melt flow rate (MFR) of EVOH (a1) (190°C, under a load of 2160 g) is preferably 0.1 to 30 g / 10 min, more preferably 0.3 to 25 g / 10 min, and even more preferably 0.5 to 20 g / 10 min. However, for those having a melting point near or exceeding 190°C, the MFR is measured under a load of 2160 g at multiple temperatures equal to or higher than the melting point, and is plotted on a semi-logarithmic graph with the reciprocal of absolute temperature on the horizontal axis and the logarithm of MFR on the vertical axis, and is expressed as a value extrapolated to 190°C.

[0018] The EVOH (a1) may be used alone or in combination of two or more kinds.

[0019] From the viewpoint of suppressing gloss, the layer (A) preferably contains a modified polyolefin (a2). The modified polyolefin (a2) is not particularly limited as long as the polyolefin has a modifying group, but the modifying group is preferably a functional group reactive with a hydroxyl group, and more preferably an acid-modified polyolefin. The functional group of the modified polyolefin (a2) includes carboxylic acid, carboxylate, and boronic acid group or a boron-containing group that can be converted to a boronic acid group in the presence of water, an isocyanate group, an amide group, an epoxy group, etc., but it is preferable that the modified polyolefin (a2) is a carboxyl group-containing modified polyolefin obtained by chemically bonding an unsaturated carboxylic acid or its anhydride to an olefin-based polymer by addition reaction, graft reaction, etc., and the unsaturated carboxylic acid or its anhydride includes maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride, etc., but maleic anhydride is preferable. Specific examples of the modified polyolefin (a2) include one or a mixture of two or more selected from acid-modified polyethylene, acid-modified polypropylene, acid-modified ethylene-ethyl acrylate copolymer, acid-modified ethylene-vinyl acetate copolymer, acid-modified ethylene-α-olefin copolymer, etc. Among them, acid-modified ethylene-α-olefin copolymer is preferred. Examples of the acid-modified ethylene-α-olefin copolymer include acid-modified products such as ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-octene copolymer, ethylene-1-butene-1-hexene copolymer, ethylene-1-butene-4-methyl-1-pentene copolymer, and ethylene-1-butene-1-octene copolymer, and maleic anhydride-modified products are preferred. The modified polyolefin (a2) may be a blend with unmodified polyolefin, but is preferably composed of only modified polyolefin.

[0020] The modification method includes, for example, a method of copolymerizing a vinyl compound having the above-mentioned functional group, a method of adding to a double bond present in a small amount in a polyolefin, and a method of grafting to introduce a functional group into a side chain. The modification method other than copolymerization is not particularly limited, and may include a method of reacting in a solution or a method of reacting in an extruder. These modified polyolefins (a2) may be used alone or in combination.

[0021] The mass ratio (a1) / (a2) of the EVOH (a1) and the modified polyolefin (a2) in the layer (A) is preferably 40 / 60 to 95 / 5. When the mass ratio (a1) / (a2) is 40 / 60 or more, the stain prevention function of the layer (A) is improved, and the film formability also tends to be improved. When the mass ratio (a1) / (a2) is 95 / 5 or less, the gloss of the layer (A) tends to be suppressed. The lower limit of the mass ratio (a1) / (a2) is more preferably 60 / 40, and further preferably 70 / 30. The upper limit of the mass ratio (a1) / (a2) is more preferably 90 / 10.

[0022] The layer (A) may contain an antibacterial agent (a3) ​​from the viewpoint of antibacterial properties. Examples of the antibacterial agent (a3) ​​include compounds containing metal ions such as silver, copper, and zinc, and organic antibacterial agents supported on inorganic compound solids. Among them, inorganic antibacterial agents containing at least one ion selected from the group consisting of silver ions, copper ions, and zinc ions are preferred from the viewpoint of effective antibacterial properties even with a small amount added. These inorganic antibacterial agents may be used alone or in combination. The content of the inorganic antibacterial agent (a3) ​​is preferably 0.01 to 5 parts by mass, more preferably 0.03 to 3 parts by mass, still more preferably 0.05 to 2 parts by mass, and particularly preferably 0.1 to 1.5 parts by mass, based on 100 parts by mass of the EVOH (a1).

[0023] In the layer (A), boron compounds such as boric acids, borate esters, and borates, carboxylic acid compounds such as carboxylic acids / carboxylates, and phosphoric acid compounds such as various acids and their salts, such as phosphoric acid and phosphorous acid, can be blended within the range that does not hinder the object of the present invention. By blending these compounds alone or in combination, the water resistance and mechanical properties of the composition, or the thermal stability during melt molding, can be improved. Although not necessarily limited, the content of the boron compound is preferably 20 to 2000 ppm in terms of boron element, the content of the carboxylic acid compound is preferably 5 to 2000 ppm, and the content of the phosphoric acid compound is preferably 5 to 300 ppm in terms of phosphate radical.

[0024] The layer (A) may also contain a plasticizer, an antioxidant, a pigment, an ultraviolet absorber, an antistatic agent, a crosslinking agent, a filler, a reinforcing agent such as various fibers, a dispersing agent such as higher fatty acids, a thermoplastic resin other than the modified polyolefin (a2), and the like.

[0025] When the layer (A) does not contain modified polyolefin (a2), the proportion of EVOH (a1) in the resin constituting the layer (A) is preferably 70% by mass or more, more preferably 85% by mass or more, even more preferably 95% by mass or more, and may be 97% by mass or more, 99% by mass or more, or 100% by mass. The proportion of EVOH in the layer (A) is preferably 70% by mass or more, more preferably 85% by mass or more, even more preferably 95% by mass or more, and may be 97% by mass or more, or 99% by mass or more. When the layer (A) contains modified polyolefin (a2), the proportion of the total of EVOH (a1) and modified polyolefin (a2) in the resin constituting the layer (A) is preferably 70% by mass or more, more preferably 85% by mass or more, even more preferably 95% by mass or more, and may be 97% by mass or more, 99% by mass or more, or 100% by mass. The total proportion of the EVOH (a1) and the modified polyolefin (a2) in the layer (A) is preferably 70% by mass or more, more preferably 85% by mass or more, even more preferably 95% by mass or more, and may be 97% by mass or more or 99% by mass or more.

[0026] The thickness of the layer (A) is not particularly limited, but from the viewpoint of industrial productivity, it is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more. The thickness of the layer (A) is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less.

[0027] (Anchor coat layer (B)) The multilayer structure of the present invention includes an anchor coat layer (B). By including the anchor coat layer (B) in the multilayer structure of the present invention, the peel strength tends to be improved.

[0028] The material constituting the anchor coat layer (B) is not particularly limited as long as it is different from the aqueous emulsion adhesive (c1), and a known anchor coat agent can be used. The anchor coat agent is preferably one that exhibits good adhesion to the layer (A) and the adhesive layer (C), and examples thereof include polyurethane adhesives. Although known polyurethane adhesives can be used, it is preferable to use a two-liquid polyurethane adhesive in which a polyisocyanate component and a polyol component are mixed and reacted. As the two-liquid polyurethane adhesive, commercially available products can be used, and examples thereof include Takelac (registered trademark) and Takenate (registered trademark) manufactured by Mitsui Chemicals, Inc.

[0029] The thickness of the anchor coat layer (B) is not particularly limited, but is preferably 0.01 to 100 μm. When the thickness of the anchor coat agent (B) layer is 0.01 μm or more, the peel strength tends to improve. On the other hand, when the thickness of the anchor coat layer (B) is 100 μm or less, the blocking resistance tends to improve. The thickness of the anchor coat layer (B) is preferably 0.02 to 50 μm, more preferably 0.05 to 10 μm, and particularly preferably 0.1 to 5 μm.

[0030] (Adhesive layer (C)) The multilayer structure of the present invention comprises an adhesive layer (C) made of a composition containing an aqueous emulsion adhesive (c1). By providing the adhesive layer (C), the blocking resistance of the multilayer structure of the present invention is improved, and when the multilayer structure of the present invention is used as wallpaper, it tends to maintain peel strength even in a relatively high temperature (about 40°C) environment. Here, the aqueous emulsion adhesive means an adhesive in which a resin is uniformly dispersed in water. In addition, the "adhesive layer (C) made of a composition containing an aqueous emulsion adhesive (c1)" means an adhesive layer obtained by applying and drying a composition containing an aqueous emulsion adhesive (c1), so the adhesive layer (C) itself is not an emulsion.

[0031] The aqueous emulsion adhesive (c1) satisfies the following condition (1). [Condition (1): 100 parts by mass of the aqueous emulsion adhesive (c1) and 82.9 parts by mass of a urethane prepolymer with a nonionic terminal isocyanate, which is a urethane curing agent, were mixed and stirred at 23°C for 10 minutes to prepare a coating liquid. The coating liquid was applied onto an EVOH layer (ethylene unit content 44 mol%, saponification degree 99.5 mol%, MFR (190°C, under a load of 2160 g) 5 g / 10 min, thickness 12 μm) so that the thickness after drying would be 0.2 μm, and the coating liquid was dried at 60°C for 5 minutes to prepare an EVOH layer. After forming a coating liquid layer on the layer, a water-based emulsion adhesive (c1) is applied onto the coating liquid layer so that the thickness after drying is 2 μm, and an adhesive layer is formed by drying at 60°C for 5 minutes. A non-foamed polyvinyl chloride wallpaper base material is laminated onto the adhesive layer, and heat-sealed using a thermal gradient sheet seal tester under conditions of a pressure of 0.1 MPa, a temperature of 130°C, and a heating time of 1 second. The interlayer peel strength between the EVOH layer and the coating liquid layer, measured in accordance with JIS K6854-3 (1999), is 1 N / 15 mm or less.] The interlayer peel strength measured under condition (1) is influenced by the content of "functional groups having high reactivity with isocyanate groups" contained in the aqueous emulsion adhesive (c1) and the high reactivity of the functional groups themselves with isocyanate groups. That is, the aqueous emulsion adhesive (c1) preferably has a low content of functional groups having high reactivity with isocyanate groups, and when it has a functional group that can react with isocyanate groups, it is preferable that the functional group has low reactivity with isocyanate groups. When the aqueous emulsion adhesive (c1) satisfies condition (1), the blocking resistance of the multilayer structure of the present invention can be improved. In addition, the peel strength tends to be maintained even in a relatively high temperature (40°C) environment. The reason for this is unclear, but it is speculated that the aqueous emulsion adhesive (c1) is less likely to bleed out when it satisfies condition (1).

[0032] The aqueous emulsion adhesive (c1) is not particularly limited as long as it satisfies the condition (1), but is preferably an aqueous emulsion of a polymer having at least one monomer unit selected from the group consisting of ethylene, vinyl chloride, and vinyl acetate, and more preferably an aqueous emulsion of a copolymer having at least two monomer units selected from the group consisting of ethylene, vinyl chloride, and vinyl acetate. In addition, as long as it satisfies the condition (1), it may have a functional group that can react with an isocyanate group, but it is preferable that it does not have a functional group that can react with an isocyanate group. The aqueous emulsion adhesive (c1) may be used alone or in combination of two or more different aqueous emulsion adhesives (c1). In addition, two or more adhesive layers (C) may be provided.

[0033] The adhesive layer (C) may contain plasticizers, pigments, ultraviolet absorbers, antistatic agents, crosslinking agents, preservatives, antifungal agents, fillers, various fibers, film-forming assistants, antibacterial agents, stabilizers, reinforcing agents such as antifoaming agents, oxidizing agents, etc., as long as the object of the present invention is not impaired.

[0034] The proportion of the resin constituting the adhesive layer (C) that is the resin constituting the aqueous emulsion adhesive (c1) is preferably 70% by mass or more, more preferably 85% by mass or more, even more preferably 95% by mass or more, and may be 97% by mass or more, 99% by mass or more, or 100% by mass. The proportion of the dry matter of the aqueous emulsion adhesive (c1) that is the adhesive layer (C) is preferably 70% by mass or more, more preferably 85% by mass or more, even more preferably 95% by mass or more, and may be 97% by mass or more, or 99% by mass or more.

[0035] The thickness of the adhesive layer (C) is preferably 0.03 μm to 500 μm, more preferably 0.1 μm to 200 μm, even more preferably 0.5 μm to 100 μm, and particularly preferably 1 μm to 50 μm. When the thickness of the adhesive layer (C) is within the above range, the adhesive layer tends to have improved adhesion to the substrate (D) described below while improving blocking resistance.

[0036] (Multilayer structure) The multilayer structure of the present invention comprises a layer (A), an anchor coat layer (B) and an adhesive layer (C). The layer structure is not particularly limited, but it is preferable that the anchor coat layer (B) is provided between the layer (A) and the adhesive layer (C). From the viewpoint of improving the peel strength, it is more preferable that one surface is directly laminated to the layer (A) and the other surface is laminated to the adhesive layer (C), that is, the layer structure is layer (A) / anchor coat layer (B) / adhesive layer (C). From the viewpoint of the application of the wallpaper, it is preferable that the total thickness of the layer (A), the anchor coat layer (B) and the adhesive layer (C) in the multilayer structure of the present invention is 5 μm or more and 50 μm or less.

[0037] The multilayer structure of the present invention is preferably an interior material further comprising a substrate (D). Examples of the interior material include, but are not limited to, wallpaper and decorative boards. The substrate (D) when the interior material is used as wallpaper is not particularly limited, but is preferably provided with a wallpaper resin layer which is at least one selected from the group consisting of polyolefins and polyvinyl chloride. The wallpaper resin layer may contain known additives that wallpaper resins may contain. The substrate (D) for wallpaper preferably comprises a paper layer, and a known paper layer used for wallpaper can be used as the paper layer. The substrate (D) for wallpaper may comprise other layers known as substrates (D) for wallpaper in addition to the wallpaper resin layer and the paper layer. The substrate (D) for decorative boards is not particularly limited, but is preferably provided with a support layer such as gypsum board, plywood, particle board, steel plate, concrete plate, etc. The substrate (D) for decorative boards preferably comprises at least one layer selected from the group consisting of a paper layer and a resin layer. Examples of the resin layer include polyvinyl chloride, etc. At least one layer selected from the group consisting of a paper layer and a resin layer may be embossed to emphasize the three-dimensional effect. The base material (D) for decorative boards is preferably a laminate of a support layer and at least one layer selected from the group consisting of a paper layer and a resin layer. The base material (D) for decorative boards is used as a base material for printed decorative boards, decorative gypsum boards, PVC decorative boards, PVC steel boards, PVC non-combustible boards, etc.

[0038] The inner layer material of the present invention may have layers other than the layer (A), the anchor coat layer (B), the adhesive layer (C) and the substrate (D) within a range that does not impair the effects of the present invention. Examples of the other layers include layers of polyesters such as polyethylene terephthalate, polyester elastomers, polyamides such as nylon-6 and nylon-66, polystyrene, polyvinylidene chloride, acrylic resins, vinyl ester resins, polyurethane elastomers, polycarbonates, chlorinated polyethylenes, and chlorinated polypropylenes.

[0039] The layer structure of the interior material of the present invention is preferably such that the substrate (D) is laminated on the adhesive layer (C) side of the multilayer structure, and more preferably such that the adhesive layer (C) and the substrate (D) are directly laminated. In addition, when the substrate (D) is a substrate (D) for wallpaper, it is preferable that the adhesive layer (C) is directly laminated with the resin layer for wallpaper. The layer structure of the interior material of the present invention is, for example, layer (A) / anchor coat layer (B) / adhesive layer (C) / substrate layer (D), and preferably layer (A) / anchor coat layer (B) / adhesive layer (C) / resin layer for wallpaper / / paper layer. The interior material of the present invention may have the other layer at any position of the layer structure.

[0040] The method for producing the multilayer structure and interior material of the present invention is not particularly limited. For example, the method includes a method in which an anchor coat agent is coated on a layer (A) and dried to form an anchor coat layer (B), an aqueous emulsion adhesive (c1) is coated on the anchor coat layer (B) and dried to form an adhesive layer (C) to produce a multilayer structure, and then thermally laminated with a substrate (D) to produce an interior material; a method in which an aqueous emulsion adhesive (c1) is coated on the anchor coat layer (B) on the substrate (D) and dried to form an adhesive layer (C), and then an anchor coat agent is coated on the adhesive layer (C) to produce an anchor coat layer (B) and a method of forming an interior material by laminating layer (A) on anchor coat layer (B) and thermally laminating it; a method of sequentially coating and drying an anchor coat agent and an aqueous emulsion adhesive (c1) on a suitable support (such as a Teflon (registered trademark) plate) (the order of forming the layers is not limited), peeling off the support to obtain a laminate of anchor coat layer (B) / adhesive layer (C), and then thermally laminating the laminate with layer (A) to form a laminate of layer (A) / anchor coat layer (B) / adhesive layer (C), and then thermally laminating the adhesive layer (C) and substrate (D) to produce an interior material; etc. Among these, a method of coating and drying an anchor coat agent on layer (A) to form an anchor coat layer (B), coating and drying an aqueous emulsion adhesive (c1) on the anchor coat layer (B) to form an adhesive layer (C) to produce a multilayer structure, and then thermally laminating the substrate (D) to produce an interior material is preferred. EXAMPLES

[0041] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples in any way.

[0042] (Materials used) EVOH(a1) a1-1: "EVAL (registered trademark) E105A" (EVOH, manufactured by Kuraray Co., Ltd., ethylene unit content 44 mol%, saponification degree 99.5 mol%, MFR (190°C, under a load of 2160 g) 5 g / 10 min) a1-2: "EVAL (registered trademark) F101A" (EVOH, manufactured by Kuraray Co., Ltd., ethylene unit content 32 mol%, saponification degree 99.5 mol%, MFR (190°C, under a load of 2160 g) 1 g / 10 min) Modified PO(a2) a2-1: Mitsubishi Chemical Corporation's "Modic (trademark) H511" (maleic anhydride modified HDPE) a2-2: "Modic (trademark) M545" (maleic anhydride modified LLDPE) manufactured by Mitsubishi Chemical Corporation Antibacterial agents (a3) A3-1: Zeomic AV10D (silver zeolite) manufactured by Sinanen Zeomix Co., Ltd. Adhesive (b1) b1-1: Urethane-based two-component adhesive (Mitsui Chemicals' "Takelac (registered trademark) W605" and "Takenate (registered trademark) WD725" are diluted 25 times with deionized water and mixed 1:1 in an aqueous dispersion) Water-based emulsion adhesive (c1) c1-1: "Vinyblan (trademark) 603" (vinyl acetate-vinyl chloride copolymer emulsion, manufactured by Nissin Chemical Industry Co., Ltd., solid content concentration 50% by mass) Adhesive with a peel strength of over 1.0 N / 15 mm under condition (1) (c'1) c'1-1: "Sumikaflex (trademark) 830" (ethylene-vinyl acetate-vinyl chloride copolymer emulsion, manufactured by Sumika Chemtex Corporation, solid content concentration 50% by mass)

[0043] (Evaluation method) (1) Peel strength under condition (1) A peel strength test was carried out for the adhesive c1-1 and the adhesive c'1-1 used in the examples and comparative examples. First, EVOHa1-1 was formed into a film under the following conditions to obtain an EVOH film. Extruder: Labo Plastomill 20mm single screw extruder manufactured by Toyo Seiki Seisakusho Co., Ltd. Die: 300mm wide coat hanger type die Extrusion temperature: 210℃ Screen: 50 / 100 / 50 mesh Screw rotation speed: 40 rpm Discharge amount: 1.1kg / hour Cast roll temperature: 50℃ Line speed: 2.5m / min Film thickness: 12μm

[0044] Next, 100 parts by mass of the aqueous emulsion adhesive (c1) and 82.9 parts by mass of "Takenate (registered trademark) WD725" were stirred at 23°C for 10 minutes to prepare a coating liquid, and the coating liquid was applied to the EVOH film obtained above so that the thickness after drying would be 0.2 μm. The coating liquid was then dried at 60°C for 5 minutes to form a coating liquid layer on the EVOH film. After that, the aqueous emulsion adhesive (c1) was applied to the coating liquid layer so that the thickness after drying would be 2 μm, and the coating liquid layer was dried at 60°C for 5 minutes to form an adhesive layer. A non-foamed polyvinyl chloride wallpaper base material manufactured by Three A Corporation was laminated on the adhesive layer and heat-sealed using a thermal gradient sheet seal tester under conditions of a pressure of 0.1 MPa, a temperature of 130°C, and a heating time of 1 second. Test samples of 15 mm width were then cut out for measurement in accordance with JIS K6854-3 (1999), and the interlayer peel strength between the EVOH layer and the coating liquid layer was measured for the test samples according to the method described in JIS K6854-3 (1999).

[0045] (2) Blocking properties For the multilayer structures obtained in the examples and comparative examples, the end of the film piece in the length direction cut to a width of 10 cm and a length of 30 cm was attached to an aluminum tube with a diameter of 25 mm with tape, and a 1 kg weight was attached to the end of the opposite side of the length direction of the film piece to apply tension to the film piece, and the aluminum tube was rotated to wrap the film piece around the aluminum tube. With the 1 kg load applied, the film piece wrapped around the aluminum tube was treated at 45°C for 24 hours. The 1 kg weight was removed from the film piece after aging, and a test was performed using an autograph at a speed of 50 mm / min using the method described below, and the measured value (N / 100 mm) was used as an index for evaluating the blocking property. (Autograph test) The aluminum tube with the film piece attached was passed through a metal rod, and the aluminum can was fixed to the chuck at the bottom of the autograph while rotating. An acrylic plate was attached to the chuck at the top of the autograph, and the film was unwound from the aluminum tube around which it was wound, and the unwound film piece was fixed to the aluminum plate with adhesive tape. A tensile test (stroke 100 mm, tensile speed 50 mm / min) was performed under this condition, and the maximum value obtained was taken as the blocking property.

[0046] (3) Peel strength from wallpaper base layer For the wallpapers obtained in the examples and comparative examples, test samples with a width of 15 mm were cut out, and the peel strength between the wallpaper base layer and the adhesive layer (C) was measured for the test samples according to the method described in JIS K6854-3 (1999). In addition, for the wallpapers obtained in the examples and comparative examples after the heating test, the peel strength between the wallpaper base layer and the adhesive layer (C) was measured in the same manner as above.

[0047] (4) Gloss The surfaces of the multilayer structures obtained in the Examples and Comparative Examples were illuminated with light from a fluorescent lamp, and the gloss due to reflected light was visually confirmed and evaluated according to the following criteria. Evaluation: Criteria A: Almost no reflection of fluorescent light B: Slightly reflects fluorescent light C: When fluorescent light is reflected, the shape of the light source is clearly visible.

[0048] (5) Antibacterial properties The wallpapers obtained in the Examples and Comparative Examples were evaluated for antibacterial properties in accordance with the method described in JIS Z2801. ·Bacterial liquid concentration: 1 / 500NB ·Bacteria liquid drop amount: 0.4ml ·Storage temperature: 35±1℃ ·Storage humidity:>90%RH Storage time: 24±1 hours Bacteria used: Staphylococcus aureus (NBRC12732), Escherichia coli (NBRC3972) Sample size: n=3. Judgment criteria A: The number of Staphylococcus aureus and Escherichia coli bacteria was below the detection limit. B: The number of either or both of Staphylococcus aureus and Escherichia coli is above the detection limit and is 1 / 100 or less than the control area. C: The number of Staphylococcus aureus, Escherichia coli, or both exceeds 1 / 100 of the control.

[0049] Example 1 The peel strength under condition (1) was measured for the adhesive c1-1 used in Example 1 according to the method described in the above evaluation method (1). The results are shown in Table 1.

[0050] EVOHa1-1 was formed into an EVOH film under the following conditions. Extruder: Toyo Seiki Seisakusho Co., Ltd. Labo Plastomill 20mm single screw extruder Die: 300mm wide coat hanger type die Extrusion temperature: 210℃ Screen: 50 / 100 / 50 mesh Screw rotation speed: 40 rpm Discharge amount: 1.1kg / hour Cast roll temperature: 50℃ Line speed: 2.5m / min Film thickness: 12μm

[0051] The adhesive b1-1 was applied to the obtained EVOH film so that the thickness after drying was 0.2 μm, and the film was dried in a dryer at 60 ° C for 5 minutes to provide an anchor coat layer (B). The adhesive layer c1-1 was applied to the anchor coat layer (B) so that the thickness after drying was 2 μm, and the film was dried in a dryer at 60 ° C for 5 minutes to provide an adhesive layer (C), thereby obtaining a multilayer structure (EVOH / anchor coat layer (B) / adhesive layer (C) = 12 μm / 0.2 μm / 2 μm). The obtained multilayer structure was evaluated for blocking properties and glossiness according to the methods described in the above evaluation methods (2) and (4). The results are shown in Table 1.

[0052] A non-foamed polyvinyl chloride wallpaper base material manufactured by Decorea Co., Ltd. was laminated on the adhesive layer (C) of the obtained multilayer structure, and the laminate was pressed with a heat press at a pressure of 1 kgf / cm. 2 The resulting wallpaper was heat laminated at a temperature of 130°C for a heating time of 1 second to produce wallpaper. The peel strength and antibacterial properties of the resulting wallpaper were evaluated according to the methods described in the evaluation methods (3) and (5) above. The results are shown in Table 1. In addition, a heating test was carried out in which the resulting multilayer structure was left at 40°C for 2 weeks, after which a non-foamed polyvinyl chloride wallpaper base material manufactured by Decorea Co., Ltd. was laminated on the adhesive layer (C) of the multilayer structure, and the multilayer structure was heated at a pressure of 1 kgf / cm using a heat press. 2 The wallpaper was then heat-laminated at a temperature of 130°C for a heating time of 1 second to produce a wallpaper after the heating test. The peel strength of the wallpaper after the heating test was evaluated according to the method described in the above evaluation method (3). The results are shown in Table 1.

[0053] Example 2 A multilayer structure and wallpaper were produced and evaluated in the same manner as in Example 1, except that a mixture of 80 parts by mass of EVOHa1-1 and 20 parts by mass of modified POa2-1 was dry-blended in a tumbler mixer for 10 minutes, and a resin composition was used that was mixed under the following conditions. The results are shown in Table 1.

[0054] (Examples 3 to 6, Comparative Example 1) A multilayer structure and wallpaper were produced and evaluated in the same manner as in Example 2, except that the type and content of EVOH (a1), the type and content of modified PO (a2), the type and content of antibacterial agent (a3), and the type of aqueous emulsion adhesive (c1) were changed as shown in Table 1. The results are shown in Table 1. The antibacterial agent (a3) ​​was mixed by dry blending EVOHa1-1 and modified POa2-2 at the same time.

[0055] Comparative Example 2 A multilayer structure and wallpaper were produced and evaluated in the same manner as in Example 2, except that the adhesive layer (C) was laminated directly on the EVOH film without providing the anchor coat layer (B). The results are shown in Table 1.

[0056] [Table 1]

Claims

1. A multilayer structure comprising: a layer (A) made of a resin composition containing an ethylene-vinyl alcohol copolymer (a1); an anchor coat layer (B); and an adhesive layer (C) made of a composition containing an aqueous emulsion adhesive (c1), wherein the aqueous emulsion adhesive (c1) satisfies the following condition (1): [Condition (1): 100 parts by mass of the aqueous emulsion adhesive (c1) and 82.9 parts by mass of a nonionic terminal isocyanate urethane prepolymer, which is a urethane curing agent, were mixed and stirred at 23°C for 10 minutes to prepare a coating liquid, which was then coated on an ethylene-vinyl alcohol copolymer layer (ethylene unit content 44 mol%, saponification degree 99.5 mol%, MFR (190°C, under a load of 2160 g) 5 g / 10 min, thickness 12 μm) so that the thickness after drying would be 0.2 μm, and the coating liquid was dried at 60°C for 5 minutes to prepare an ethylene-vinyl alcohol copolymer layer. After forming a coating liquid layer on the ethylene-vinyl alcohol copolymer layer, an aqueous emulsion adhesive (c1) is applied onto the coating liquid layer to a thickness of 2 μm after drying, and dried at 60° C. for 5 minutes to form an adhesive layer. A non-foamed vinyl chloride wallpaper substrate is laminated onto the adhesive layer, and heat-sealed using a thermal gradient sheet seal tester under conditions of a pressure of 0.1 MPa, a temperature of 130° C., and a heating time of 1 second. After that, the interlayer peel strength between the ethylene-vinyl alcohol copolymer layer and the coating liquid layer, measured in accordance with JIS K6854-3 (1999), is 1 N / 15 mm or less.]

2. 2. The multilayer structure of claim 1, wherein layer (A) comprises a modified polyolefin (a2).

3. 3. The multilayer structure according to claim 2, wherein the modified polyolefin (a2) is a maleic anhydride modified polyolefin.

4. 3. The multilayer structure according to claim 2, wherein the mass ratio (a1) / (a2) of the ethylene-vinyl alcohol copolymer (a1) to the modified polyolefin (a2) in the layer (A) is 40 / 60 to 95 / 5.

5. The multilayer structure according to claim 3, wherein the mass ratio (a1) / (a2) of the ethylene-vinyl alcohol copolymer (a1) to the modified polyolefin (a2) in the layer (A) is 40 / 60 to 95 / 5.

6. An interior material comprising the multilayer structure according to any one of claims 1 to 5 and a substrate (D).