JP2017159537A - Multilayer resin sheet, layered sheet, method for producing multilayer resin sheet, method for producing layered sheet, and method for producing foaming wall paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer resin sheet from which a foaming wall paper having excellent scratch resistance while having sufficient interlaminar adhesiveness can be produced even under a high-temperature and high-humidity environment; to provide a layered sheet; to provide methods for producing such a multilayer resin sheet and such a layered sheet; and to provide a method for producing a foaming wall paper.SOLUTION: The multilayer resin sheet includes: a first layer including a foaming agent-containing resin composition including a first resin and a foaming agent; and a second layer including a foaming agent-free resin composition including a second resin and no foaming agent. In the multilayer resin sheet, the first resin includes an ethylene homopolymer or a copolymer of ethylene and another olefin, containing 50 mol% or more of an ethylene unit, and the second resin includes a polyethylene having a density of 0.920 g/cmor more.SELECTED DRAWING: None

Description

  The present invention relates to a multilayer resin sheet, a laminated sheet, a method for producing a multilayer resin sheet, a method for producing a laminated sheet, and a method for producing foamed wallpaper. More specifically, the present invention relates to a method for producing foamed wallpaper that can be used for wall decoration of buildings such as detached houses, apartment houses, stores, office buildings, etc., multilayer resin sheets and laminated sheets used therefor, and these It relates to the manufacturing method.

  As foam wallpaper used for wall decoration of buildings, etc., vinyl chloride resin foam wallpaper and plastic foam wallpaper in which a paper base is provided with a resin layer of vinyl chloride resin or other plastics are widely used.

  As a method for producing these foamed wallpaper, a resin composition containing a foaming agent is laminated on a base material while being formed into a sheet by a melt extrusion molding method such as a T-die, or separately sheeted and dried afterwards. A method of foaming a resin sheet printed on the surface as needed after obtaining a laminated sheet in which a resin sheet is provided on the substrate by laminating a substrate by lamination or heat lamination (For example, see Patent Document 1 below). These methods are advantageous in terms of production efficiency as compared with a coating method in which a resin composition is applied and dried on a substrate and a calendering method.

  As a technique for improving the surface strength of a foamed wallpaper, a foamed wallpaper in which a non-foamed resin layer is provided on a foamed resin layer has been proposed (see, for example, Patent Documents 2 and 3 below).

Patent No. 4629188 JP 2007-31893 A JP 2007-313900 A

  However, even the foamed wallpaper described in Patent Documents 2 and 3 may cause a problem in practical use, and there is room for further improvement. On the other hand, when a non-foamed resin layer with increased surface strength is provided to enhance scratch resistance, if the interlaminar adhesion at the interface between the foamed resin layer and the non-foamed resin layer deteriorates, for example, posters etc. on wallpaper After affixing, there may be a problem that delamination occurs when the posted material is peeled off, and the design properties are greatly impaired. Such a problem becomes prominent particularly when the laminated sheet is placed in a high-temperature and high-humidity environment or when the wallpaper is used in a high-temperature and high-humidity environment.

  The present invention has been made in view of the above circumstances, and is a multilayer resin sheet capable of producing a foam wallpaper having excellent scratch resistance while having sufficient interlayer adhesion even in a high temperature and high humidity environment. An object of the present invention is to provide a laminated sheet, a production method thereof, and a production method of foamed wallpaper.

In order to solve the above problems, the present invention includes a first layer comprising a foaming agent-containing resin composition containing a first resin component and a foaming agent, a second resin component, and a foaming agent. A multilayer resin sheet having a second layer made of a non-foaming agent-containing resin composition, wherein the first resin component contains an ethylene homopolymer or an ethylene unit of 50 mol% or more, ethylene and other Provided is a multilayer resin sheet comprising a copolymer with olefin, wherein the second resin component comprises polyethylene having a density of 0.920 g / cm ³ or more.

  By using the multilayer resin sheet of the present invention, it is possible to produce a foamed wallpaper excellent in scratch resistance while having sufficient interlayer adhesion even in a high temperature and high humidity environment.

  Regarding the reason why such an effect can be obtained, the present inventors can obtain the effect of improving the scratch resistance by the second layer by combining the first layer and the second layer containing the specific resin component, and at a high temperature and high level. It is assumed that even if the resin component is gradually crystallized in a wet environment, the strain between the first layer and the second layer can be reduced, and the adhesion at the interface of the laminated structure is sufficiently secured. To do.

  The first resin component preferably further contains a silane crosslinkable resin. By including the silane crosslinkable resin in the first resin component, only the first layer can be selectively crosslinked. Accordingly, when the first layer is foamed, the followability of the second layer with respect to the first layer can be improved, so that the adhesion between both layers can be improved and the surface strength can be improved. Further, when the first resin component is cross-linked, it is not necessary to cross-link by electron beam irradiation or heat, and yellowing of the base material or resin can be suppressed.

  It is preferable that the foaming agent-free resin composition further includes at least one selected from the group consisting of a phenol radical scavenger and a hindered amine radical scavenger. By including at least one selected from the group consisting of a phenolic radical scavenger and a hindered amine radical scavenger in the foaming agent-free resin composition, a multilayer resin sheet having excellent weather resistance can be obtained. The foamed wallpaper produced from such a multilayer resin sheet is unlikely to deteriorate in scratch resistance with time.

  The foaming agent-free resin composition may further contain an ultraviolet absorber. Thereby, a multilayer resin sheet having further excellent weather resistance can be obtained.

  Moreover, this invention provides a laminated sheet provided with a base material and the multilayer resin sheet which concerns on the said this invention provided on this base material.

  Furthermore, this invention is a manufacturing method of the multilayer resin sheet which concerns on the said invention, Comprising: The said 1st layer and the said said by extruding the said foaming agent containing resin composition and the said foaming agent non-containing resin composition, respectively A step of forming a second layer, or a step of forming the first layer and the second layer by coextrusion molding at least the foaming agent-containing resin composition and the foaming agent-free resin composition, A method for producing a multilayer resin sheet is provided. According to the method for producing a multilayer resin sheet of the present invention, a multilayer resin sheet having a resin layer containing a foaming agent and a resin layer containing no foaming agent can be efficiently produced.

  Furthermore, this invention is a manufacturing method of the laminated sheet which concerns on the said invention, Comprising: The manufacturing method of a laminated sheet provided with the process of laminating the multilayer resin sheet obtained by said method on the base material is provided.

  In the method for producing a laminated sheet, in the cross-linking step of cross-linking part or all of the resin contained in the multilayer resin sheet before or during lamination on the substrate, or the resin contained in the multilayer resin sheet in the laminated sheet You may further provide the bridge | crosslinking process which bridge | crosslinks a part or all of a part. According to the laminated sheet obtained by obtaining such a crosslinking step, it is possible to suppress gas escape during foaming, and it is easy to obtain a foamed resin layer that is uniform and has little gas escape from the surface.

  Furthermore, the present invention is a method for producing a foam wallpaper comprising a base material and a foamed resin layer provided on the base material, the foaming agent contained in the first layer in the laminated sheet according to the present invention. A foamed wallpaper manufacturing method comprising a foaming step of forming a foamed resin layer by foaming a foam.

  According to the present invention, a multilayer resin sheet capable of producing a foam wallpaper having excellent scratch resistance while having sufficient interlayer adhesion even in a high temperature and high humidity environment, a laminated sheet, and a production method thereof, In addition, a method for producing foamed wallpaper can be provided.

  In this specification, the ethylene unit contained in the copolymer means a structural unit derived from ethylene.

[Multilayer resin sheet]
The multilayer resin sheet according to the present embodiment includes a first layer composed of a foaming agent-containing resin composition containing a first resin component and a foaming agent, and a foam containing a second resin component and no foaming agent. And a second layer made of an agent-free resin composition.

<Foaming agent-containing resin composition>
The first resin component in the foaming agent-containing resin composition includes an ethylene homopolymer or a copolymer of ethylene and another olefin containing 50 mol% or more of ethylene units. By using such a resin component, the influence on the environment can be made smaller than in the case of using a halogen-based resin such as polyvinyl chloride resin. Furthermore, the film formation stability during extrusion molding is further improved, and the foamed cells when foaming agent is foamed become finer, and a multilayer for realizing a foamed wallpaper having a better foamed state. A resin sheet can be obtained. In addition to the above, since the surface energy of the base resin is large, the effect of improving the ink affinity due to the reduction of bleed out is more greatly exhibited.

  In addition, ethylene homopolymers and copolymers of ethylene and other olefins are nonpolar non-halogen thermoplastic resins, and by using these, the increase in viscosity when the amount of filler is increased can be further suppressed. Therefore, high quality wallpaper can be produced stably.

  Examples of the ethylene homopolymer include low density polyethylene synthesized by a high pressure method, high density polyethylene not containing a comonomer synthesized by a medium pressure method, and the like. Among these, low density polyethylene is preferable.

Low density polyethylene, for example, those having a density in the range of 0.91 g / cm ³ or more 0.94 g / cm ³ or less. The density of low-density polyethylene is preferably not 0.91 g / cm ³ or more 0.93 g / cm ³ or less, more preferably 0.92 g / cm ³ or more 0.93 g / cm ³ or less. The molecular weight, melting point, melt flow rate (MFR) and the like of the low density polyethylene are not particularly limited, but the melting point is preferably 50 ° C to 140 ° C, more preferably 60 ° C to 110 ° C. When the melting point is 140 ° C. or lower, it is not necessary to melt the resin and mold it at a higher temperature, and the foaming agent can be prevented from being decomposed during molding. On the other hand, if the melting point is 50 ° C. or higher, thermal durability in actual use can be easily obtained. The MFR is preferably from 3 to 150, more preferably from 4 to 100. If MFR is 3 or more, shear heat generation that occurs during molding can be suppressed, the processing temperature can be easily controlled, and the foaming agent can be prevented from being decomposed during molding. On the other hand, if MFR is 150 or less, the mechanical strength of the produced foamed wallpaper is maintained, and a layer excellent in workability and durability is easily formed.

  Examples of the low density polyethylene include Novatec LD LC802A, Novatec LD LC604, Novatec LD LJ902, Novatec LD LJ802A (above, manufactured by Nippon Polyethylene Co., Ltd.), Ube Polyethylene J2516 (produced by Ube Maruzen Polyethylene Co., Ltd.), Petrocene 202, 209 ( As described above, commercially available products such as Tosoh Corporation) can be used.

  Examples of copolymers of ethylene and other olefins containing 50 mol% or more of ethylene units include linear low density polyethylene, ultra low density polyethylene, and high density polyethylene obtained by copolymerization with a comonomer. These can be used singly or in combination of two or more. Among these, ultra-low density polyethylene is preferable.

The ultra low density polyethylene, for example, those having a density in the range of less than 0.85 g / cm ³ or more 0.91 g / cm ^3. The density of the ultra-low density polyethylene is preferably 0.86 g / cm ³ or more and 0.90 g / cm ³ or less, more preferably 0.87 g / cm ³ or more and 0.90 g / cm ³ or less, and still more preferably 0.87 g / cm ³ or more and 0.90 g / cm ³ or less, particularly preferably 0.88 g / cm ³ or more and 0.90 g / cm ³ or less, and most preferably 0.89 g / cm ³ or more and 0.90 g or less. / Cm ³ or less. The molecular weight, melting point, MFR and the like of the ultra-low density polyethylene are not particularly limited, but the melting point is preferably 50 to 100 ° C, more preferably 55 to 90 ° C. If the melting point is 100 ° C. or lower, it is not necessary to melt the resin and mold it at a higher temperature, and the foaming agent can be prevented from being decomposed during molding. On the other hand, if the melting point is 50 ° C. or higher, thermal durability in actual use can be easily obtained. The MFR is preferably from 3 to 150, more preferably from 4 to 100. If MFR is 3 or more, shear heat generation that occurs during molding can be suppressed, the processing temperature can be easily controlled, and the foaming agent can be prevented from being decomposed during molding. On the other hand, if MFR is 150 or less, the mechanical strength of the produced foamed wallpaper is maintained, and a layer excellent in workability and durability is easily formed.

  Examples of the ultra-low density polyethylene include Tafmer DF840, DF940, DF7350 (all manufactured by Mitsui Chemicals), Kernel KJ-640T (manufactured by Nippon Polyethylene Co., Ltd.), Excellen FX CX5508 (manufactured by Sumitomo Chemical Co., Ltd.), Engage 8400. / 8407 (manufactured by Dow Chemical Co., Ltd.), Evolue P SP90100 (manufactured by Prime Polymer Co., Ltd.), LumiTac 09L54A (manufactured by Tosoh Corporation) and the like can be used.

  As linear low-density polyethylene, commercial items, such as Nipolon-LM55, LM65, LM70, LM75 (above, Tosoh Corporation make), can be used, for example.

  Moreover, the 1st resin part may contain the silane crosslinkable resin. Examples of the silane crosslinkable resin include a resin having a hydrolyzable silyl group. For example, a silane crosslinkable polyolefin resin or the like can be used. Examples of the silane crosslinkable polyolefin resin include a resin in which a hydrolyzable silyl group is mainly introduced into a side chain in a polyolefin polymer as a matrix. Examples of such a resin include a resin in which a hydrolyzable silyl group is mainly introduced into a side chain in a polymer such as a low density polyethylene, a high density polyethylene, an ethylene-vinyl acetate copolymer, and a polypropylene. Crosslinking is performed by hydrolysis of substituted silyl groups. In addition, the polyolefin resin which this silyl group is located in the terminal may be contained.

  Silane crosslinkable polyolefin resin is a method of random copolymerization in a container of polyolefin polymer monomer and ethylenically unsaturated silane compound, or using a peroxide in the polyolefin polymer melt. It can be obtained by a method of graft copolymerizing a silane compound. Here, the polyolefin polymer as a matrix can be used alone or in combination of two or more of the above resins. Further, the base polyolefin-based resin may be a combination of the polyolefin-based resin and a resin different from the polyolefin-based resin as long as mixing or decomposition of the resins is allowed. The degree of mixing or dispersion varies greatly depending on the type of extruder to be used, and an appropriate compatibilizer can be used. Therefore, the combined resins cannot be generally distinguished, but are preferably the same type of resins. Specific examples of the silane crosslinkable resin include “LINKLON” manufactured by Mitsubishi Chemical Corporation.

  The first resin component may contain a resin component other than those described above as long as the effects of the present invention are not impaired. Such a resin component is not particularly limited. For example, in addition to halogen-based resins such as polyvinyl chloride resin, as non-halogen-based resins, for example, copolymers of ethylene and other olefins other than those described above, Polyolefin resin (single olefin polymer such as polypropylene, polybutene, polymethylpentene, etc., random or block copolymer of two or more olefins), styrene resin (polystyrene, acrylonitrile / styrene copolymer (AS), acrylonitrile)・ Butadiene / styrene copolymer (ABS), etc.), ethylene copolymer (ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-acrylic acid copolymer, ethylene- Ethyl acrylate copolymer, ethylene - methyl acrylate copolymer, ethylene - methacrylic acid copolymer) and the like. These can be used alone or in combination of two or more. These resin components are 20 parts by mass or less with respect to 100 parts by mass of the total amount of the ethylene homopolymer or the copolymer of ethylene and other olefins containing 50 mol% or more of ethylene units. Is preferable, and it is more preferable that it is 10 mass parts or less. From the viewpoint of sufficiently exerting the effects of the present invention, it is more preferable not to include these resin components.

  The content of the first resin is preferably from 30 to 95% by mass based on the total amount of the foaming agent-containing resin composition, from the viewpoint of film formability of the resin sheet, More preferably, it is 90 mass%, It is still more preferable that it is 55-80 mass%, It is still more preferable that it is 60-80 mass%.

  As the foaming agent according to the present embodiment, for example, a pyrolytic foaming agent can be used. Examples of the pyrolytic foaming agent include azo foaming agents such as azodicarbonamide (ADCA), azobutyronitrile, and diazoaminobenzene, hydrazide foaming agents such as p-toluenesulfonyl hydrazide, and N, N′-di. Examples thereof include nitroso-based foaming agents such as nitrosopentamethylenetetramine. Among these, ADCA is preferable because it has little toxicity, easily adjusts the foaming start temperature, and has a wide application range. These can be used alone or in combination of two or more.

  Examples of the foaming agent include VINYHALL AC # 3C-K2 (manufactured by Eiwa Kasei Co., Ltd., azodicarbonamide-based foaming agent), Cellular D (manufactured by Eiwa Kasei Co., Ltd., nitroso-based foaming agent), Neoselbon SB # 51 (Yewa Kasei). Commercial products such as a hydrazide-based foaming agent (manufactured by Corporation) can be used.

  Although content of a foaming agent is not restrict | limited in particular, It is preferable that the total amount is 1-20 mass% on the basis of the foaming agent containing resin composition whole quantity. When the content of the foaming agent is within the above range, it is possible to obtain a foamed resin layer in which gas escape from the surface due to generation of excessive gas is suppressed.

  The foaming agent-containing resin composition according to this embodiment may be colored by adding a pigment or the like as necessary. Coloring by adding a pigment may be transparent, translucent, or opaque. Examples of the pigment include inorganic pigments such as iron oxide and carbon black, and organic pigments such as aniline black and phthalocyanine blue.

  In addition, the foaming agent-containing resin composition according to the present embodiment includes, as necessary, a filler, a flame retardant other than the filler, a foaming aid, a cell conditioner, a stabilizer, a lubricant, a silane crosslinking aid, an acrylic. Known additives such as a system crosslinking aid and an isocyanurate-based crosslinking aid can be used.

  Examples of the filler include inorganic fillers and organic fillers. Examples of inorganic fillers include calcium carbonate, titanium dioxide, and hydrated metal compounds. Examples of the organic filler include melamine cyanurate, polytetrafluoroethylene (PTFE), wood flour, cellulose and derivatives thereof. These fillers can be used alone or in combination of two or more.

  Especially, it is preferable that a hydrated metal compound and calcium carbonate are included as an inorganic filler. By using a hydrated metal compound and calcium carbonate in combination as a filler, a multilayer resin sheet excellent in scratch resistance can be obtained more effectively.

  A hydrated metal compound refers to a metal compound that dehydrates by heating. Such a hydrated metal compound can release moisture by heating. Examples of the hydrated metal compound include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, manganese hydroxide, iron hydroxide, zinc hydroxide, copper hydroxide and the like.

  The hydrated metal compound preferably has a particle size. The average particle size of the hydrated metal compound is preferably 5 μm or less, and more preferably 3 μm or less. By setting the average particle size of the hydrated metal compound to 5 μm or less, the surface area is increased and a large amount of water is dehydrated at one time. As a result, the amount of water used for the silane crosslinking reaction is increased, and crosslinking is performed more efficiently. The lower limit of the average particle size of the hydrated metal compound is preferably 0.01 μm or more, and more preferably 0.1 μm or more, from the viewpoint of suppressing an increase in viscosity. The average particle size of the hydrated metal compound is a 50% average particle size corresponding to the median value of the particle size distribution, and can be measured using, for example, a commercially available particle size distribution measuring apparatus.

  The hydrated metal compound may be subjected to various surface treatments from the viewpoint of improving dispersibility, moldability, flame retardancy, and the like. Examples of the hydrated metal compound subjected to such surface treatment include, from the viewpoint of improving dispersibility and moldability, for example, nitrate anion-treated aluminum hydroxide, high-temperature hydrothermally treated aluminum hydroxide, and the like. From the viewpoint of improving flame retardancy, for example, nitrate-treated aluminum hydroxide, zinc stannate surface-treated aluminum hydroxide, nickel compound surface-treated magnesium hydroxide, etc., phlogopite treatment, silicone treatment, silicone polymer treatment, etc. Examples include hydrated metal compounds that have been treated.

  The content of the filler is preferably 5% by mass or more based on the total amount of the foaming agent-containing resin composition, and 20% by mass or more, from the viewpoint of obtaining a foam wallpaper having excellent scratch resistance. More preferably, it is more preferably 25% by mass or more. On the other hand, the upper limit of the content of the filler is preferably 60% by mass or less, and preferably 50% by mass or less, based on the total amount of the foaming agent-containing resin composition, from the viewpoint of suppressing an increase in the viscosity of the resin composition. Is more preferable, it is still more preferable that it is 40 mass% or less, and it is still more preferable that it is 30 mass% or less.

  Examples of the flame retardant other than the filler include phosphorus-based flame retardants such as phosphate esters, bromine-based flame retardants such as tetrabromobisphenol A, and the like.

  Examples of foaming aids include aliphatic systems such as stearic acid and lauric acid, fatty acid amide systems such as stearic acid amide and oleic acid amide, urea systems such as biurea, metal chlorides such as zinc chloride, and zinc oxide. A metal oxide etc. are mentioned.

  Moreover, you may use a fatty-acid metal salt as a foaming adjuvant. By including a fatty acid metal salt, a resin sheet having good foamability can be obtained.

  The fatty acid metal salt is preferably a functional group-containing fatty acid metal salt having a functional group on the carbon chain of the fatty acid metal salt. Here, the carbon chain of the fatty acid metal salt refers to a linear hydrocarbon group constituting the fatty acid. The linear hydrocarbon group may be saturated or unsaturated, and preferably has 6 to 30 carbon atoms. However, when the number of carbon atoms decreases, the melting point of the metal soap (fatty acid metal salt) decreases. The number of carbon atoms is more preferably 10 to 24 from the viewpoint that it becomes liquid and difficult to handle, and that if the carbon chain is too long, the melting point becomes too high and the decomposability at the molding temperature decreases. Examples of fatty acids having such a hydrocarbon group include saturated fatty acids such as hexanoic acid, stearic acid, lauric acid, and behenic acid, dicarboxylic acids such as sebacic acid and azelaic acid, oleic acid, linoleic acid, and undecylenic acid. And the like, and the like.

  Examples of the functional group of the functional group-containing fatty acid metal salt include an organic group that is directly bonded to the linear hydrocarbon group. The number of functional groups is not particularly limited, and when the molecule has two or more functional groups, they may be the same as or different from each other.

  Examples of the functional group include a hydroxyl group, an alkyl group, a sulfonyl group (sulfonic acid ester), a sulfonyl group (phosphorous acid ester), a trifluoromethyl group, and the like. Among these, the functional group is preferably a readily available hydroxyl group. By using the hydroxyl group-containing fatty acid metal salt, the electrical intermolecular interaction resulting from the strong polarization of the hydroxyl group works more strongly, bleed out is more effectively reduced, and printability can be further improved. In particular, when an ethylene homopolymer or a copolymer of ethylene and another olefin is combined as the resin component, the surface energy of the base resin is large, so the effect of improving ink affinity by reducing bleed out is greater. It is possible to obtain a resin sheet or a laminated sheet as a foam raw material that is exhibited and has good printing characteristics.

  Examples of the functional group-containing fatty acid of the functional group-containing fatty acid metal salt include 2-ethylhexanoic acid, hydroxylauric acid, hydroxystearic acid, ricinoleic acid, dihydroxystearic acid, dihydroxylauric acid and the like.

  Examples of the metal of the functional group-containing fatty acid metal salt include barium, magnesium, calcium, zinc and the like, and are preferably at least one selected from the group consisting of magnesium, calcium and zinc. Among these, zinc is particularly useful because it has a very strong surface-active effect and strong activity as a foaming aid.

  From the viewpoints described above, the functional group-containing fatty acid metal salt according to this embodiment includes 2-ethylhexanoic acid zinc salt, hydroxylauric acid zinc salt, hydroxystearic acid zinc salt, dihydroxystearic acid zinc salt, and dihydroxylauric acid zinc salt. A metal salt of 12-hydroxystearic acid such as zinc 12-hydroxystearate is more preferable from the viewpoint of availability and cost. These functional group-containing fatty acid metal salts can be used alone or in combination of two or more.

  As content of a foaming adjuvant, it is preferable that the total amount exists in the range of 1-100 mass parts with respect to 100 mass parts of foaming agents, and it is more within the range of 2-50 mass parts. Preferably, it is in the range of 3 to 30 parts by mass. If content of the foaming adjuvant with respect to 100 mass parts of foaming agents exists in the said range, the effect as surfactant and foaming adjuvant can fully be exhibited.

  As the cell regulator, either an organic cell regulator or an inorganic cell regulator may be used, and examples thereof include silica, phosphate ester compounds, acrylic ester resins, and methacrylic ester resins. . Commercially available products such as ADK STAB HP-10 (manufactured by ADEKA), Irgafos 38 (manufactured by BASF Japan), and JPP-2000 (manufactured by Johoku Chemical Industry Co., Ltd.) can be used as the cell regulator. it can.

  Stabilizers include, for example, phenol / amine antioxidants, hindered amines, phenols and other radical scavengers, phosphorus and sulfur peroxides, benzotriazoles, hydroxyphenyltriazines, benzophenones And ultraviolet absorbers. From the viewpoint of suppressing discoloration, a phenol radical scavenger, a hindered amine radical scavenger, or the like may be used. As the radical scavenger, commercially available products such as Tinuvin 783 (manufactured by BASF Japan) can be used. Commercially available products such as Tinuvin 326 (manufactured by B.A.S.F. Japan) can be used as the ultraviolet absorber.

  Examples of the lubricant include fatty acid-based lubricants such as stearic acid and lauric acid, fatty acid amide-based compounds such as stearic acid amide and oleic acid amide, and fatty acid metal salt-based lubricants such as zinc stearate, calcium laurate and zinc octylate. It is done.

  Examples of the silane crosslinking aid include a tin-based crosslinking aid.

  Examples of the acrylic crosslinking aid include trimethylpropane triacrylate (TMPTA) and trimethylpropane trimethacrylate (TMPTMA).

  Examples of the isocyanurate-based crosslinking aid include triaryl isocyanurate.

<Foaming agent-free resin composition>
The foaming agent-free resin composition according to the present embodiment includes the second resin component and does not include the foaming agent.

The second resin component in the foaming agent-free resin composition includes polyethylene having a density of 0.920 g / cm ³ or more. By using polyethylene having a density of 0.920 g / cm ³ or more as the second resin component contained in the second layer in the multilayer resin sheet, the surface strength of the second layer is sufficiently secured, Sufficient interlayer adhesion with the second layer can be ensured. In view of the above, the density of the polyethylene as the second resin component is preferably from 0.930 g / cm ³ or more, more preferably 0.940 g / cm ³ or more, more preferably 0.950 g / cm ³ or more . On the other hand, the upper limit of the density of polyethylene is not particularly limited, but from the viewpoint of more effectively suppressing the strain between the first layer and the second layer accompanying crystallization, for example, 0.980 g / cm ³ or less is preferable, and 0.960 g / cm ³ or less is more preferable.

Examples of polyethylene having a density of 0.920 g / cm ³ or more include commercially available products such as Novatec HD HJ490 (manufactured by Nippon Polyethylene Co., Ltd.), M6910 (manufactured by Keiyo Polyethylene Co., Ltd.), Suntec J311 (manufactured by Asahi Kasei Chemicals Corporation). Can be used.

  Further, the second resin component may contain a silane crosslinkable resin. As the silane crosslinkable resin, the same silane crosslinkable resin contained in the first resin component described above can be used. In addition, from the viewpoint of obtaining a foam wallpaper superior in scratch resistance, the silane crosslinkable resin contained in the second resin component has a density of the base resin higher than that of the silane crosslinkable resin contained in the first resin component. It is preferable to use a high one.

The second resin component may contain a resin component other than polyethylene having a density of 0.920 g / cm ³ or more as long as the effects of the present invention are not impaired. The resin content is not particularly limited. For example, in addition to halogen-based resins such as polyvinyl chloride resin, non-halogen-based resins include, for example, ethylene homopolymers, copolymers of ethylene and other olefins. Polymer polyolefin resin (single olefin polymer such as polypropylene, polybutene, polymethylpentene, etc., random or block copolymer of two or more olefins), styrene resin (polystyrene, acrylonitrile / styrene copolymer (AS)) Acrylonitrile / butadiene / styrene copolymer (ABS), ethylene copolymer (ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid copolymer, etc.). These can be used alone or in combination of two or more. These resins are preferably 50 parts by mass or less and more preferably 20 parts by mass or less with respect to 100 parts by mass of the total amount of polyethylene having a density of 0.920 g / cm ³ or more. From the viewpoint of sufficiently exerting the effects of the present invention, it is more preferable not to include these resin components.

  The content of the second resin is preferably 50 to 100% by mass based on the total amount of the resin composition containing no foaming agent, from the viewpoint of film formability of the resin sheet. More preferably, it is -100 mass%.

  Moreover, each component (however, except a foaming agent) demonstrated in the said foaming agent containing resin composition may be included in the foaming agent non-containing resin composition which concerns on this embodiment as needed.

  Especially, it is preferable that the foaming agent non-containing resin composition which concerns on this embodiment contains radical scavengers, such as a phenol type radical scavenger and a hindered amine type radical scavenger. Thereby, the multilayer resin sheet excellent in weather resistance can be obtained, and the fall of the flaw resistance by deterioration with time can be suppressed. The content of the radical scavenger is preferably 0.01 to 2% by mass and more preferably 0.1 to 1% by mass based on the total amount of the foaming agent-free resin composition.

  In addition, although the thickness of each layer which comprises a multilayer resin sheet can be suitably set according to a use, for example, if it is a foam wallpaper application, the thickness of a 1st layer will be 40-100 micrometers and the thickness of a 2nd layer. It can be 5-40 micrometers.

  In addition to the first layer and the second layer, the multilayer resin sheet according to the present embodiment includes a second resin component and a third layer made of a second foaming agent-free resin composition containing no foaming agent. May be further provided. By further providing such a third layer, the foaming agent-containing resin composition can be co-extruded with two foaming agent-free resin compositions, and the foaming agent and the die come into contact with each other. Problems that occur, for example, a phenomenon in which foreign matter adheres to the edge portion of the discharge port (so-called “eyes”) can be reduced, and productivity can be further improved. From such a viewpoint, the multilayer resin sheet according to this embodiment preferably has a laminated structure in which the second layer, the first layer, and the third layer are laminated in this order.

  The third resin component in the second foaming agent-free resin composition is not particularly limited, and those similar to the first resin component and the second resin component described above can be used. From the viewpoint of further improving the adhesion to the base material to be described later, it is preferable to include ultra-low density polyethylene as the third resin component.

  In addition, the second foaming agent-free resin composition according to the present embodiment may include each component described in the foaming agent-containing resin composition (excluding the foaming agent) as necessary. Good.

  Although the thickness of the said 3rd layer can be suitably set according to a use, for example, if it is a foam wallpaper application, the thickness of a 3rd layer can be 1-20 micrometers.

[Method for producing multilayer resin sheet]
The multilayer resin sheet according to the present embodiment can be obtained by extruding the foaming agent-containing resin composition and the foaming agent-free resin composition described above, and optionally the second foaming agent-free resin composition. it can.

  There is no restriction | limiting in particular as the method of extrusion molding, For example, you may form a 1st layer and a 2nd layer by extruding the said foaming agent containing resin composition and a foaming agent non-containing resin composition, respectively. The first layer and the second layer may be formed by coextrusion molding at least the foaming agent-containing resin composition and the foaming agent-free resin composition. When the first layer and the second layer are formed by extruding the foaming agent-containing resin composition and the foaming agent-free resin composition, respectively, the first layer and the second layer are laminated to form a multilayer. A resin sheet can be manufactured.

  In the multilayer resin sheet further comprising the third layer, for example, by extruding the foaming agent-free resin composition, the foaming agent-containing resin composition, and the second foaming agent-free resin composition, respectively, Two layers, a first layer, and a third layer may be formed, or by coextrusion molding a foaming agent-free resin composition, a foaming agent-containing resin composition, and a second foaming agent-free resin composition A multilayer resin sheet having a laminated structure in which the second layer, the first layer, and the third layer are laminated in this order may be formed. Furthermore, the second layer and the first layer are obtained by co-extrusion molding the foaming agent-free resin composition and the foaming agent-containing resin composition, and by extruding the second foaming agent-free resin composition. And the third layer may be formed, or the foaming agent-containing resin composition and the second foaming agent-free resin composition are coextruded, and separately, the foaming agent-free resin composition is extruded. Thus, the second layer, the first layer, and the third layer may be formed.

  When the second layer, the first layer, and the third layer are formed by extruding the foaming agent-free resin composition, the foaming agent-containing resin composition, and the second foaming agent-free resin composition, respectively. A multilayer resin sheet can be produced by laminating the second layer, the first layer, and the third layer in this order.

  Examples of the coextrusion molding method include a coextrusion method such as a T die extrusion method, a T die extrusion simultaneous lamination method, and a T die extrusion tandem lamination method.

  Specifically, for example, when co-extrusion molding of a foaming agent-containing resin composition and a foaming agent-free resin composition, the foaming agent-containing resin composition and the foaming agent-free resin composition are respectively separated into separate extruders (for example, A single-screw extruder, a twin-screw extruder, etc.), and after melting and kneading and dispersing them in a feed block type, a sheet is formed with a T-die, and a first composition comprising a foaming agent-containing resin composition Examples thereof include a method of obtaining a resin sheet comprising two layers of a second layer comprising a layer and a foaming agent-free resin composition.

  As a condition for extrusion molding of the foaming agent-containing resin composition with a T-die, it is preferable to set the extrusion temperature to 140 ° C. or lower from the viewpoint of setting the melting point of the first resin or higher while suppressing decomposition of the foaming agent component. The temperature is more preferably 135 ° C. or lower, and further preferably 130 ° C. or lower. Moreover, extrusion temperature can be made into melting | fusing point +10 degreeC or more of resin with the highest melting | fusing point. Thereby, it can suppress that resin is extruded in an unmelted state.

  As a condition for extrusion molding with a T-die of the foaming agent-free resin composition, the extrusion temperature is preferably 170 ° C. or lower and 165 ° C. or lower from the viewpoint of setting the melting point of the second resin or higher. More preferred is 155 ° C. or lower. Moreover, extrusion temperature can be made into melting | fusing point +10 degreeC or more of resin with the highest melting | fusing point. Thereby, it can suppress that resin is extruded in an unmelted state.

  Moreover, in the extrusion molding by T-die, from the viewpoint of efficiently melting the second resin component in the foaming agent-free resin composition while suppressing decomposition of the foaming agent component in the foaming agent-containing resin composition, for example, foaming When the second resin component in the resin-free resin composition is melted with an extruder, the resin component is melted at a relatively high temperature (for example, 140 ° C. or higher, preferably 150 ° C. or higher), and the foaming agent is a feed block type. A method of merging both at a relatively low temperature (for example, 135 ° C. or less, preferably 130 ° C. or less) may be used when merging with the containing resin composition. High-density polyethylene generally has a high melting point, so it is necessary to increase the extrusion molding temperature. However, when the resins merge in coextrusion molding, the resin composition of the foaming agent-containing resin composition is affected by the influence of the resin temperature of the foaming agent-free resin composition. There is a possibility that the foaming agent in the product will be decomposed. On the other hand, as mentioned above, when the foaming agent-free resin composition is melted with an extruder, the resin component is melted at a relatively high temperature, and when the resin composition is merged with the foaming agent-containing resin composition, it is merged at a relatively low temperature. By making it, decomposition | disassembly of a foaming agent can be suppressed. In addition, since the melting temperature of polyethylene is higher than the crystallization temperature, once it is melted at a high temperature, it is difficult to solidify even if the resin temperature is lowered to the vicinity of the melting point.

  The first layer in the multilayer resin sheet may be subjected to a crosslinking treatment. Examples of the crosslinking treatment include heat treatment such as electron beam irradiation treatment and superheated steam treatment. When the foaming agent-containing resin composition contains a silane crosslinkable resin, superheated steam treatment and water crosslinking treatment can be performed. In this case, the first layer can be cross-linked while being laminated with other layers.

  In the electron beam irradiation treatment, for example, the multilayer resin sheet can be crosslinked by irradiating an electron beam from one side or both sides of the molded multilayer resin sheet. Although the electron beam irradiation conditions depend on the thickness of the resin layer, an acceleration voltage of 150 to 300 kV and an irradiation dose of 10 to 100 kGy are preferable. If the acceleration voltage is within the above range, the electron beam can be sufficiently reached deep in the thickness direction of the resin sheet, and deterioration due to the electron beam on the backing paper can be suppressed. Moreover, if irradiation dose is in the said range, it will become easy to give desired bridge | crosslinking to a resin sheet, suppressing the yellowing of a resin sheet and the change of a mechanical physical property.

  Examples of the superheated steam treatment include a method in which superheated steam (also referred to as superheated steam) is treated for 20 seconds to 15 minutes in an environment of 130 ° C. to 280 ° C. The superheated steam treatment includes, for example, a method in which a sheet-like material is arranged in a superheated steam atmosphere and the superheated steam is brought into contact with the sheet-like material. Moreover, as a method of water-crosslinking, there is a method of water-crosslinking by curing for 1 day to 1 month in a temperature range of 40 ° C. to 70 ° C. in an environment with a humidity of 60% or more. There is a method of curing and hydrocrosslinking in an environment of a 90% constant temperature and humidity chamber.

[Laminated sheet]
The laminated sheet according to the present embodiment includes a base material and the multilayer resin sheet provided on the base material.

The base material is not particularly limited as long as it is usually used as a paper base material such as a conventional backing paper for foam wallpaper. As such a substrate, for example, a pulp-based flame retardant paper impregnated with a water-soluble flame retardant such as guanidine sulfamate or guanidine phosphate, or an inorganic agent such as magnesium carbonate, aluminum hydroxide, magnesium hydroxide or the like. Examples include mixed paper. These weighings may be 50 to 300 g / m ² or 60 to 160 g / m ² .

  In addition, from the viewpoint of improving the adhesion between the base material and the multilayer resin sheet, the surface of the base material on the side where the multilayer resin sheet is provided is easily adhered, for example, by corona discharge treatment, plasma treatment, ozone treatment, etc. You may give a process and may provide the easily bonding process layer formed from the acrylic-butyl copolymer, the polyurethane which consists of isocyanate and a polyol.

[Production method of laminated sheet]
The laminated sheet according to the present embodiment includes, for example, a step of laminating a multilayer resin sheet obtained by the above method on a base material. From the viewpoint of more effectively obtaining the effects of the present invention, the laminated sheet preferably includes a step of laminating the first layer in the multilayer resin sheet on the substrate.

  The laminating method is not particularly limited, and examples thereof include a method in which a multilayer resin sheet and a substrate are subjected to thermocompression bonding using a hot press machine, a method in which pressure bonding is performed using superheated steam, and the like. . According to the method of pressure bonding using superheated steam, it becomes possible to laminate onto the base material while maintaining the molten state of the surface of the sheet-like material with superheated steam, and the surface of the base material to be adhered by the leveling effect Can be prevented from being transferred to the multilayer resin sheet. Moreover, when the 1st layer in a multilayer resin sheet contains a silane crosslinkable resin, a silane crosslinkable resin can be bridge | crosslinked efficiently with superheated steam.

  The manufacturing method of the lamination sheet which concerns on embodiment forms a 1st layer and a 2nd layer by extruding the said foaming agent containing resin composition and a foaming agent non-containing resin composition, respectively, for example, the said 2nd After laminating the layer on the base material, a step of laminating the first layer on the surface of the second layer opposite to the base material may be provided.

  Further, when the third layer is provided, for example, after laminating the third layer on the base material, the first layer is laminated on the surface of the third layer opposite to the base material side, and You may provide the process of laminating the 2nd layer on the surface on the opposite side to the 3rd layer side of the 1st layer concerned. In addition, after laminating the third layer on the base material, laminating the first layer side of the laminate having the first layer and the second layer on the surface of the third layer opposite to the base material side Or after laminating the third layer side of the laminate having the first layer and the third layer onto the substrate, the second layer is opposite to the substrate side of the first layer. A step of laminating on the surface may be provided.

  The method for producing a laminated sheet according to the present embodiment includes a cross-linking step of cross-linking part or all of the resin contained in the multi-layer resin sheet before or during lamination on the substrate, or the multi-layer resin sheet in the multi-layer sheet A cross-linking step of cross-linking part or all of the resin component contained in the resin may be further provided. The crosslinking treatment can be the same as the method described in the method for producing the multilayer resin sheet. When the multilayer resin sheet contains a silane crosslinkable resin, lamination and crosslinking of the silane crosslinkable resin can be performed simultaneously with superheated steam.

[Method for producing foam wallpaper]
The foam wallpaper according to the present embodiment includes a base material and a foamed resin layer provided on the base material. Such foamed wallpaper can be obtained by a method for producing foamed wallpaper, which includes a foaming step of forming a foamed resin layer by foaming the foaming agent contained in the first layer in the laminated sheet.

  Foaming of the foaming agent can be performed by heating the multilayer resin sheet. The heating condition can be appropriately set depending on the components constituting the multilayer resin sheet, and is not particularly limited, but is preferably heated at 160 ° C. to 280 ° C. for 10 seconds to 120 seconds, and at 220 ° C. to 240 ° C. Heating for 20 to 40 seconds is more preferable, and heating at 220 ° C. for 40 seconds is more preferable.

  The method for producing foamed wallpaper according to the present embodiment includes a cross-linking step of cross-linking part or all of the resin contained in the multi-layer resin sheet before being laminated on the substrate, or a multi-layer resin sheet in a laminated sheet A cross-linking step of cross-linking part or all of the resin component contained in the resin may be further provided. The crosslinking treatment can be the same as the method described in the method for producing the multilayer resin sheet. When the resin sheet contains a silane crosslinkable resin, lamination and crosslinking of the silane crosslinkable resin can be performed simultaneously with superheated steam.

  Furthermore, in the manufacturing method of the foam wallpaper which concerns on this embodiment, the uneven | corrugated shape formation process which provides an uneven | corrugated shape in the surface on the opposite side to the base material of the said 2nd layer may be provided. An uneven | corrugated shape formation process can be equipped after the said foaming process, for example. The method for providing the uneven shape is not particularly limited. For example, by using heat at the time of heating and foaming, the surface side is a cooling embossing roll, the base material side is a rubber roll, Examples of the method include forming a concavo-convex shape on the surface by niping (embossing) and cooling. The uneven shape is not particularly limited, and examples thereof include a wood grain plate conduit groove, a stone plate surface unevenness, a cloth surface texturer, a satin texture, a grain texture, a hairline, and a single line groove. These can be appropriately selected according to the purpose, and a plurality of them may be combined.

  The method for producing foam wallpaper according to the present embodiment may include a printing step of providing a pattern layer and a surface protective layer. The pattern layer and the surface protective layer can be appropriately provided using known materials. If the object of the present invention can be achieved, the pattern layer and the surface protective layer may not be provided. The pattern layer and the surface protective layer can be provided using a known printing technique such as gravure coating. In addition, a printing process can be provided before the said foaming process, for example. That is, the pattern layer and the surface protective layer can be provided before foaming the foaming agent.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples.

[Foaming agent-containing resin composition]
Using a same-direction meshing twin screw extruder, while controlling the resin temperature at 120 ° C. so that the foaming agent is not decomposed, the pellets of the foaming agent-containing resin composition are prepared with the composition shown in Table 1 (unit: parts by mass). did.

  The following materials were used for each component shown in Table 1.

[Low density polyethylene]
Resin A: Novatec LD LJ802A (manufactured by Nippon Polyethylene Co., Ltd., trade name, melting point = 107 ° C., MFR = 27 (190 ° C.), density = 0.919 g / cm ³ , ethylene unit content = 100 mol%)

[Ultra low density polyethylene]
Resin B: Kernel KJ-640T (manufactured by Nippon Polyethylene Co., Ltd., trade name, melting point = 58 ° C., MFR = 30 (190 ° C.), density = 0.85 g / cm ³ , ethylene unit content = 88 mol%)

[Silane crosslinkable resin]
Resin C: Linkron SS732N (Mitsubishi Chemical Corporation, trade name, polyethylene base, melting point = 58 ° C., MFR = 13 (190 ° C.), density = 0.885 g / cm ³ )

[titanium dioxide]
Filler A: Taipei CR-60-2 (Ishihara Sangyo Co., Ltd., trade name)

[Calcium carbonate]
Filler B: Softon 1000 (Bihoku Powder Chemical Co., Ltd., trade name)

Foaming agent: VINYHALL AC # 3C-K2 (manufactured by Eiwa Kasei Kogyo Co., Ltd., trade name, azodicarbonamide foaming agent)

Foaming aid: Zn-St (Nitto Kasei Kogyo Co., Ltd., trade name, zinc stearate)

Silane crosslinking aid: Linkron LZ013 (Mitsubishi Chemical Corporation, trade name, polyethylene base)

Radical scavenger: Tinuvin 783 (trade name, manufactured by BASF Japan)

[Foaming agent-free resin composition]
Using the same direction meshing type twin screw extruder, pellets of the foaming agent-free resin composition were prepared with the composition shown in Table 2 (unit: parts by mass) while controlling the resin temperature at 150 ° C.

  The following materials were used for each component shown in Table 2.

[polyethylene]
Resin D: Novatec HD HJ490 (manufactured by Nippon Polyethylene Co., Ltd., trade name, melting point = 133 ° C., MFR = 25 (190 ° C.), density = 0.958 g / cm ³ , ethylene unit content = 100 mol%)

[polypropylene]
Resin E: Wintech WSX03 (manufactured by Nippon Polypro Co., Ltd., trade name, ethylene random polypropylene, melting point = 125 ° C., MFR = 25 (230 ° C.), density = 0.9 g / cm ³ , propylene content = 96 mol%)

[Silane crosslinkable resin]
Resin F: Linkron HM600A (Mitsubishi Chemical Corporation, trade name, polyethylene base, melting point = 132 ° C., MFR = 9 (190 ° C.), density = 0.955 g / cm ³ )

Ultraviolet absorber: Tinuvin 326 (manufactured by BASF Japan, trade name)

[Second foaming agent-free resin composition]
The resin B was prepared as a pellet of the second foaming agent-free resin composition.

[Production of foam wallpaper]
(Examples 1-4, Comparative Examples 1-2)
The pellets of the foaming agent-containing resin compositions 1 to 3 prepared above, the pellets of the foaming agent-free resin compositions 4 to 9 and the pellets of the second foaming agent-free resin composition were used in combinations shown in Table 3. Thus, a multilayer resin sheet was produced. Specifically, pellets of the foaming agent-free resin composition were prepared using a screw 1 (screw diameter (D) 50 mm, L / D (screw length divided by screw diameter) = 28 single screw extruder). Extrusion, pellets of foaming agent-containing resin composition were extruded using screw 2 (single screw extruder with screw diameter (D) 65 mm, L / D = 28), and screw 3 (screw diameter (D) 50 mm, L / D = 28 single-screw extruder), the pellets of the second foaming agent-free resin composition were extruded and joined together in a feed block type, and then sheeted at a line speed of 20 m / min with a 700 mm wide T-die. From a second layer (thickness 20 μm) made of a foaming agent-free resin composition, a first layer (thickness 60 μm) made of a foaming agent-containing resin composition, and a second foaming agent-free resin composition The first A multilayer resin sheet comprising three layers (thickness 10 μm) was obtained. Moreover, the temperature setting value of each screw at the time of making it merge with a feed block type was 130 degreeC for screw 1, 130 degreeC for screw 2, and 130 degreeC for screw 3.

Next, the multilayer resin sheet formed as described above was placed on the backing paper (KJ Special Paper, WK-6651HT, weight 65 g / m ² ), and heated at 110 ° C. with a press pressure of 5 MPa. The laminate sheet was obtained by pressing for a minute and heat-sealing.

Furthermore, after the corona discharge treatment was applied to the surface on the second layer side, a pattern was printed at 1 g / m ² using a water-based ink (manufactured by Dainichi Seika Kogyo Co., Ltd., Hydrick WP) with a gravure printing machine. A matte surface coating agent (Nissin Chemical Industry Co., Ltd., Viniblanc 890) was applied at 2 g / m ² using a coating machine (manufactured by Kurashiki Boseki Co., Ltd., GP-10) to prepare a raw material before cross-linking.

  In Examples 1 to 3 and Comparative Examples 1 and 2, the obtained raw material before cross-linking was irradiated with an electron beam at an acceleration voltage of 180 kV and an irradiation dose of 70 kGy to cross-link the resin, and then the oven at 220 ° C. Was heated for 40 seconds to foam the foaming agent to produce a foam wallpaper.

  In Example 4, after curing for 72 hours in a constant temperature and humidity chamber at a temperature of 40 ° C. and a relative humidity of 90% RH, the silane crosslinkable resin was crosslinked, and then heated in an oven at 220 ° C. for 40 seconds to obtain a foaming agent. To make a foam wallpaper.

[Evaluation of multilayer resin sheet]
(Interlayer adhesion)
For the multilayer resin sheets prepared in Examples 1 to 4 and Comparative Examples 1 to 2, the tape is peeled after a 1 inch wide tape is applied to the second layer side, and the second layer peels off following the tape. Was evaluated as “B”, and “A” when no peeling occurred. The results are shown in Table 3.

(Interlayer adhesion under high temperature and high humidity)
The multilayer resin sheets of Examples 1 to 4 and Comparative Examples 1 to 3 stored for 1 week at a temperature of 40 ° C. and a humidity of 90%, and the multilayers of Examples 1 to 4 and Comparative Examples 1 to 3 stored for 1 week at a temperature of 80 ° C. About the resin sheet, it peels after sticking a 1-inch-wide tape on the second layer side, and the case where the second layer peels off following the tape is “B”, and the case where it does not peel is “A”. evaluated. The results are shown in Table 3.

[Evaluation of foam wallpaper]
(Scratch resistance)
The scratch resistance was evaluated using a Coins scratch tester. Specifically, the foam wallpaper was placed on a horizontal surface, and the surface condition was observed by scratching the foam wallpaper with a load of 800 g and 1000 g using a 10 yen coin at an angle of 45 °. The case where the test surface was not damaged was evaluated as “A”, and the case where the test surface was damaged was evaluated as “B”. The results are shown in Table 3.

(Weatherability)
After performing a weather resistance test for 288 hours and 576 hours using a sunshine fade meter, the surfaces were scratched in the same manner as described above at a load of 200 g, 400 g, 600 g and 800 g, and the surface state was observed. The case where the test surface was not damaged was evaluated as “A”, and the case where the test surface was damaged was evaluated as “B”. The results are shown in Table 3.

Claims (9)

A first layer composed of a foaming agent-containing resin composition containing a first resin component and a foaming agent, and a second layer composed of a foaming agent-free resin composition containing a second resin component and not containing a foaming agent. A multilayer resin sheet having a layer,
The first resin component contains an ethylene homopolymer or a copolymer of ethylene and another olefin containing 50 mol% or more of ethylene units,
The multilayer resin sheet in which the second resin component contains polyethylene having a density of 0.920 g / cm ³ or more.   The multilayer resin sheet according to claim 1, wherein the first resin component further includes a silane crosslinkable resin.   The multilayer resin sheet according to claim 1 or 2, wherein the foaming agent-free resin composition further comprises at least one selected from the group consisting of a phenol radical scavenger and a hindered amine radical scavenger.   The multilayer resin sheet according to any one of claims 1 to 3, wherein the foaming agent-free resin composition further comprises an ultraviolet absorber.   A laminated sheet comprising: a base material; and the multilayer resin sheet according to any one of claims 1 to 4 provided on the base material. A method for producing a multilayer resin sheet according to any one of claims 1 to 4,
Forming the first layer and the second layer by extruding the foaming agent-containing resin composition and the foaming agent-free resin composition, respectively, or at least the foaming agent-containing resin composition and the foaming agent; Forming the first layer and the second layer by coextrusion of a non-containing resin composition;
A method for producing a multilayer resin sheet. It is a manufacturing method of the lamination sheet according to claim 5,
The manufacturing method of a lamination sheet provided with the process of laminating the multilayer resin sheet obtained by the method of Claim 6 on the base material.   A crosslinking step of crosslinking a part or all of the resin contained in the multilayer resin sheet before or during lamination on the substrate, or the resin content contained in the multilayer resin sheet in the laminated sheet The manufacturing method of the lamination sheet of Claim 7 further equipped with the bridge | crosslinking process which bridge | crosslinks part or all. A foamed wallpaper manufacturing method comprising: a base material; and a foamed resin layer provided on the base material,
A method for producing foam wallpaper, comprising a foaming step of forming a foamed resin layer by foaming the foaming agent contained in the first layer in the laminated sheet according to claim 5.