JP2017088746A - Resin composition, and manufacturing method of resin sheet, laminate sheet and foam wallpaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition having excellent foaming properties and sufficient printability, and also to provide a manufacturing method of a resin sheet, a laminate sheet and a foam wallpaper.SOLUTION: A foam wall paper includes a base material and a resin foam layer disposed on the base material. A resin composition is for forming the resin foam layer. The resin composition includes a filler, a foaming agent, a foam auxiliary and a resin content. The foam auxiliary includes, in an aromatic ring, an aromatic carboxylic acid metal salt having secondary or higher alkyl group or cycloalkyl group.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition, and a method for producing a resin sheet, a laminated sheet, and 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., a resin sheet used therefor, and a method for producing a laminated sheet, In addition, the present invention relates to a resin composition.

  As wallpaper used for wall decoration of buildings, etc., vinyl chloride wallpaper in which a resin layer of vinyl chloride resin is provided on a paper base material is widely used. In recent years, in consideration of the environment, non-chlorinated thermoplastic resins such as ethylene-vinyl acetate copolymers have been used (for example, see Patent Documents 1 and 2 below).

  As a method for producing such foamed wallpaper, a resin composition containing a foaming agent is melt-extruded and laminated on a base material, or is separately sheeted by a T-die extrusion method, and later applied to dry lamination or heat lamination. After laminating the base material to obtain a laminated sheet with a resin sheet provided on the base material, the resin sheet with the surface printed thereon is heated as necessary to decompose and foam the foaming agent. There is a way to make it.

  In foamed wallpaper of a type to which such a thermal decomposition type foaming agent is added, it is known that a fatty acid metal salt is used as a foaming aid for the purpose of accelerating the decomposition of the foaming agent and adjusting the decomposition temperature. For example, Patent Document 3 discloses that zinc stearate and zinc octylate are used as foaming aids.

Japanese Patent Laid-Open No. 6-47875 JP 2001-347611 A JP 2010-228416 A

  However, the resin sheet for foamed wallpaper containing the above-described fatty acid metal salt so as to obtain a high foaming ratio is used for products such as printing on the surface, such as ink adhesion, pattern pattern transferability, etc. Printability sometimes deteriorated.

  The present invention has been made in view of the above circumstances, and provides a resin composition having good foamability and sufficient printability, and a method for producing a resin sheet, a laminated sheet, and foamed wallpaper. Objective.

  In order to solve the above problems, the present invention is a resin composition for forming a foamed resin layer of foamed wallpaper comprising a base material and a foamed resin layer provided on the base material. A resin containing an agent, a foaming agent, a foaming aid, and a resin component, wherein the foaming aid contains an aromatic carboxylic acid metal salt having a secondary or higher alkyl group or cycloalkyl group in the aromatic ring A composition is provided.

  According to the resin composition of the present invention, a resin sheet having good foamability and sufficient printability can be formed. The present inventors infer the reason why such an effect is obtained as follows. First, as a factor that decreases the printability of a resin sheet containing a conventional fatty acid metal salt, the surfactant activity of the fatty acid metal salt is very strong, and bleeds out to the surface on which printing is performed or the printing interface after printing. It is conceivable that the fatty acid metal salt decreases the wettability of the surface and the ink affinity, or decreases the adhesion of the ink. On the other hand, in the present invention, by using an aromatic carboxylic acid metal salt having a surface activity lower than that of the fatty acid metal salt and further having a bulky alkyl group in the aromatic ring, foaming property is obtained. The present inventors consider that the printability is maintained because the bleeding out to the surface on which printing is performed or the printing interface after printing can be reduced while sufficiently obtaining the effect of improving printing.

  In addition, according to the resin composition of the present invention, for example, a sufficient non-foaming layer is provided on the surface of the laminated sheet to ensure sufficient printability without requiring treatment such as blocking the bleeding out of the foaming aid. Therefore, a resin sheet having both sufficient printability and good foamability can be formed with a simpler sheet structure.

  The resin component preferably contains a non-chlorine thermoplastic resin. In this case, it is possible to realize a foam wallpaper having a smaller influence on the environment.

  The resin component can include at least an ethylene homopolymer or a copolymer of ethylene and another olefin. Ethylene homopolymers or copolymers of ethylene and other olefins are considered less suitable for printing than other polar resins (eg, ethylene-vinyl acetate polymers, acrylic resins and polyester resins). However, the printability can be sufficiently ensured by the combination with the above aromatic carboxylic acid metal salt. Further, by using such a nonpolar thermoplastic resin, it is possible to minimize the thickening effect when various fillers such as titanium dioxide or calcium carbonate are added. By minimizing the thickening effect, the draw resonance is improved and the film-forming stability is improved. In addition, the excessive increase in screw rotation torque and resin pressure in the extruder can be suppressed, and at the same time, heat generation of the resin due to shearing is minimized. It is also possible to limit to the limit.

  It is preferable that content of the said aromatic carboxylic acid metal salt exists in the range of 50-100 mass parts with respect to 100 mass parts of foaming agents. When the content of the aromatic carboxylic acid metal salt is within the above range, it is possible to form a resin sheet that can achieve both good foamability and sufficient printability at a higher level.

  It is preferable that content of the said aromatic carboxylic acid metal salt exists in the range of 1-10 mass parts with respect to 100 mass parts of resin parts. When the content of the aromatic carboxylic acid metal salt is within the above range, it is possible to form a resin sheet that can achieve both good foamability and sufficient printability at a higher level.

  Moreover, this invention provides the manufacturing method of a resin sheet provided with the resin sheet formation process which forms a resin sheet by carrying out extrusion film forming of the resin composition concerning the said invention.

  The present invention also includes a resin sheet forming step of forming a resin sheet by extrusion film formation of the resin composition according to the present invention, and a laminated sheet formation in which a resin sheet is laminated on a substrate to obtain a laminated sheet And a process for producing a laminated sheet.

  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 resin sheet before or during lamination on the substrate, or the resin content contained in the resin sheet in the laminated sheet You may further provide the bridge | crosslinking process which bridge | crosslinks part or all. Thereby, the gas escape at the time of foaming can be suppressed, and the foamed resin layer with little gas escape from the surface can be obtained.

  The present invention is also a method for producing a foam wallpaper comprising a base material and a foamed resin layer provided on the base material, wherein the resin composition according to the present invention is formed by extrusion film formation. A resin sheet forming step of forming a sheet, a laminate sheet forming step of laminating a resin sheet on a substrate to obtain a laminate sheet, and a foamed resin layer by foaming a foaming agent contained in the resin sheet in the laminate sheet A foaming step of forming a foam wallpaper.

  In the method for producing foamed wallpaper, a crosslinking step for crosslinking a part or all of the resin contained in the resin sheet before or during lamination on the substrate, or the resin content contained in the resin sheet in the laminated sheet You may further provide the bridge | crosslinking process which bridge | crosslinks part or all. Thereby, the gas escape at the time of foaming can be suppressed, and the foamed resin layer with little gas escape from the surface can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the manufacturing method of the resin composition which has favorable foamability, and sufficient printability, and a resin sheet, a lamination sheet, and a foam wallpaper.

[Resin composition]
The resin composition according to the present embodiment is a resin composition for forming a foamed resin layer of a foamed wallpaper comprising a base material and a foamed resin layer provided on the base material, and a filler, A foaming agent, a foaming aid, and a resin component.

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

  The content of the filler is not particularly limited, but the total amount is preferably 10 to 60% by mass based on the total amount of the resin composition. Reasons for adding the filler include ensuring the concealment of the foamed wallpaper, reducing the calories burned per unit area, reducing the manufacturing cost by increasing the bulk, etc., but containing fillers (particularly inorganic fillers) When the amount is 20 to 40% by mass based on the total amount of the resin composition, it is possible to produce a foam wallpaper having a low combustion calorie while ensuring good concealability as the foam wallpaper and having a low production cost.

  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.

  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 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 auxiliary agent according to this embodiment may be an aromatic carboxylic acid metal salt having a secondary or higher alkyl group or cycloalkyl group in the aromatic ring (hereinafter, referred to as an aromatic carboxylic acid metal salt according to this embodiment). )including. Examples of the aromatic carboxylic acid metal salt according to this embodiment include those generally represented by the following formula (1) when the metal is monovalent.
_{^{R f -COO - M 1 + (}} 1)
In the formula (1), R _f represents an aromatic ring having a secondary or higher alkyl group or cycloalkyl group, and M ₁ represents a monovalent metal element. Examples of the monovalent metal element include sodium, lithium, potassium, and the like.

In the aromatic carboxylic acid metal salt according to this embodiment, the metal is preferably divalent. When a metal is bivalent, what is generally represented as following formula (2) is mentioned.
^{_{[R f -COO] 2 - M}} 2 2+ (2)
In the formula (2), R _f represents an aromatic ring having a secondary or higher alkyl group or cycloalkyl group, and M ₂ represents a divalent metal element.

  Examples of the aromatic ring include monocyclic aromatic rings and polycyclic aromatic rings. Examples of the monocyclic aromatic ring include benzene, furan, pyrrole, and pyridine. Examples of the polycyclic aromatic ring include naphthalene and anthracene. From the viewpoints of material cost, melting point of metal salt, handleability, etc., benzene is preferable.

  Examples of the secondary or higher alkyl group include an alkyl group having 3 to 4 carbon atoms such as an isopropyl group, a sec-butyl group, and a tert-butyl group. As said cycloalkyl group, C3-C6 cycloalkyl groups, such as a cyclopropyl group and a cyclohexyl group, are mentioned, for example. Among these, an isopropyl group and a tert-butyl group are preferable from the viewpoint of easy availability of the compound. Two or more of these secondary and higher alkyl groups and cycloalkyl groups may be present on the aromatic ring, and in this case, each alkyl group may be the same or different.

  Examples of the metal element include barium, magnesium, calcium, and zinc. In particular, when the metal element is zinc, the activity as a foaming aid is very strong, which is particularly useful.

  Moreover, the aromatic carboxylic acid metal salt which concerns on this embodiment may have a 1 or 2 or more polar functional group in an aromatic ring. When the aromatic ring has a polar functional group, examples of the polar functional group include a hydroxyl group, a primary alkyl group, a sulfonyl group (sulfonate ester), a phosphonyl group (phosphite ester), and a trifluoromethyl group. Can be mentioned.

  The substitution position of the secondary or higher alkyl group or cycloalkyl group on the aromatic ring is not particularly limited. For example, in the case where the aromatic ring is benzene, from the viewpoint of availability of the compound, aromatic The para-position of the group carboxylic acid metal salt is preferred.

  The aromatic carboxylic acid metal salt according to the present embodiment is preferably p-tert-butylbenzoic acid zinc salt, p-sec-butylbenzoic acid zinc salt, 4-isopropylbenzoic acid zinc salt, or the like from the viewpoints described above. These can be used alone or in combination of two or more.

  As content of the aromatic carboxylic acid metal salt which concerns on this embodiment, it is preferable to exist in the range of 50-100 mass parts with respect to 100 mass parts of foaming agents, and it exists in the range of 50-80 mass parts. More preferably, it is still more preferably in the range of 50 to 70 parts by mass. When the content is in the range of 50 to 100 parts by mass with respect to 100 parts by mass of the foaming agent, a resin composition having better printability and expansion ratio can be obtained.

  As content of the aromatic carboxylic acid metal salt which concerns on this embodiment, it is preferable to exist in the range of 1-10 mass parts with respect to 100 mass parts of resin parts mentioned later, and in the range of 2-6 mass parts It is more preferable that When the content is in the range of 1 to 10 parts by mass with respect to 100 parts by mass of the resin content, a resin composition having better printability and expansion ratio can be obtained. That is, when the content is 1 part by mass or more, the effect as a foaming assistant for the aromatic carboxylic acid metal salt is sufficiently obtained, and the decomposition efficiency of the foaming agent can be further improved, and 10 parts by mass or less. If it is, it is hard to receive the influence of the aromatic carboxylic acid metal salt which exists on the surface of the resin sheet formed into a film, and it can maintain printability more favorable.

  The foaming aid of the present embodiment may contain a foaming aid other than the above-described aromatic carboxylic acid metal salt as long as the effects of the present invention are not impaired. Examples of such 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, and fatty acid metal salts such as zinc stearate, calcium laurate, and zinc octylate. In addition to the system, urea system, zinc chloride, zinc oxide and the like can be mentioned.

  Moreover, as content of the aromatic carboxylic acid metal salt with respect to foaming adjuvant, it is preferable to exist in the range of 50-100 mass% on the basis of foaming adjuvant whole quantity, and it exists in the range of 75-100 mass%. It is more preferable. If the content is in the range of 50 to 100% by mass based on the total amount of the foaming aid, a resin sheet having better printability can be obtained.

  The resin component according to the present embodiment preferably contains a non-chlorine thermoplastic resin from the viewpoint of further reducing the influence on the environment. Non-chlorine thermoplastic resins include, for example, ethylene homopolymers, copolymers of ethylene and other olefins, polyolefin resins (polypropylene, polybutene, polymethylpentene, etc.), styrene resins (polystyrene, acrylonitrile / styrene resins) , Acrylonitrile / butadiene / styrene resin, etc.), ethylene copolymer (ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer) Polymer, ethylene-methacrylic acid copolymer, etc.). These can be used alone or in combination of two or more.

  Especially, it is preferable that the non-chlorine-type thermoplastic resin which concerns on this embodiment is nonpolar. By using such a non-polar non-chlorine thermoplastic resin, the thickening effect when the above-mentioned filler is added can be minimized, and high-quality wallpaper can be stably produced. it can. Moreover, it is more preferable that such a nonpolar non-chlorine thermoplastic resin contains an ethylene homopolymer or a copolymer of ethylene and another olefin. By using an ethylene homopolymer or a copolymer of ethylene and another olefin, 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 exhibited more greatly.

  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. If 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 is less likely to decompose during molding. On the other hand, if the melting point is 50 ° C. or higher, sufficient heat durability in actual use can be obtained. The MFR is preferably from 3 to 150, more preferably from 4 to 100. If the MFR is 3 or more, shear heat generated during molding can be suppressed, the processing temperature can be easily controlled, and there is little possibility that the foaming agent will be decomposed during molding. On the other hand, if the MFR is 150 or less, the mechanical strength of the produced foamed wallpaper is maintained, and the workability and durability are excellent.

  As low-density polyethylene, for example, commercially available products such as Novatec LD LC802A, Novatec LD LC604 (manufactured by Nippon Polyethylene Co., Ltd.), Ube Polyethylene J2516 (produced by Ube Maruzen Polyethylene Co., Ltd.) can be used.

  Examples of the copolymer of ethylene and other olefins include linear low density polyethylene, ultra-low density polyethylene, high density polyethylene obtained by copolymerization with a comonomer, and the like. Alternatively, two or more types can be used in combination. 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 0.88 g / cm ³ or more 0.91 g / cm ^3. The density of the ultra-low density polyethylene is preferably 0.88 g / cm ³ or more and 0.90 g / cm ³ or less, more preferably 0.89 g / cm ³ or more and 0.90 g / cm ³ or less. The molecular weight, melting point, MFR, etc. of the ultra-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. If 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 is less likely to decompose during molding. On the other hand, if the melting point is 50 ° C. or higher, sufficient heat durability in actual use can be obtained. The MFR is preferably from 3 to 150, more preferably from 4 to 100. If the MFR is 3 or more, shear heat generated during molding can be suppressed, the processing temperature can be easily controlled, and there is little possibility that the foaming agent is decomposed during molding. On the other hand, if the MFR is 150 or less, the mechanical strength of the produced foamed wallpaper is maintained, and the workability and durability are excellent.

  Examples of the ultra-low density polyethylene include Tafmer DF140, DF940, DF7350 (all of which are manufactured by Mitsui Chemicals, Inc.), Kernel KJ-640T (manufactured by Nippon Polyethylene Co., Ltd.), Excellen FX CX5508 (manufactured by Sumitomo Chemical Co., Ltd.), Commercial products such as Engage 8400/8407 (manufactured by Dow Chemical Co., Ltd.) and Evolue P SP90100 (Prime Polymer Co., Ltd.) can be used.

  The non-chlorine thermoplastic resin as a resin component may contain a 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 content of the non-chlorine thermoplastic resin in the resin component is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and 80% by mass or more. It is particularly preferable that it is 90% by mass or more. In particular, the resin component is most preferably made of a non-chlorine thermoplastic resin.

  The total resin content is preferably 20 to 80% by mass, more preferably 40 to 75% by mass, and 50 to 70% by mass based on the total amount of the resin composition. More preferably it is. In this case, the resin component may be cross-linked.

  The resin content according to this embodiment preferably has a chlorine atom content of 0 to 10 mass%, more preferably 0 to 5 mass%. In particular, it is more preferable that the resin component according to this embodiment does not contain a chlorine atom. Examples of the method for calculating the chlorine atom content in the resin component include the oxygen flask combustion method described in JIS-K-7229.

  In addition, the resin composition according to the present 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.

  The addition amount of the pigment is preferably 5 to 50% by mass, more preferably 10 to 30% by mass based on the total amount of the resin composition.

  Moreover, well-known additives, such as a flame retardant, a cell regulator, a stabilizer, and a lubricant, can be used for a resin composition as needed.

  Examples of the flame retardant include metal hydroxide flame retardants such as magnesium hydroxide and aluminum hydroxide, phosphorus flame retardants such as phosphate ester, and bromine flame retardants such as tetrabromobisphenol A.

  Examples of the cell modifier include acrylic ester resins and methacrylic ester resins.

  Stabilizers include, for example, radical scavengers such as phenol / amine antioxidants, hindered amine light stabilizers, peroxide decomposers such as phosphorus and sulfur, benzotriazoles, hydroxyphenyltriazines, and benzophenones. Examples include ultraviolet absorbers.

  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.

[Production method of resin sheet]
The manufacturing method of the resin sheet which concerns on this embodiment is equipped with the resin sheet formation process which forms a resin sheet by carrying out extrusion film forming of the resin composition which concerns on the said this embodiment.

  Examples of the extrusion film forming method include extrusion molding such as T-die extrusion method, T-die extrusion simultaneous lamination method, T-die extrusion tandem lamination method, circular die extrusion method, and circular die inflation extrusion method.

  In addition to extrusion molding, the resin sheet can also be produced by known molding methods such as injection molding, press molding, blow molding, calendar molding, coating molding, cast molding, dipping molding, vacuum molding, transfer molding, and the like.

  The resin composition can be used by appropriately pelletizing each component after melting, kneading and dispersing with an extruder. The extruder may be a single-screw extruder or a twin-screw extruder, but a twin-screw extruder is preferable in view of the influence on productivity and quality.

  Extrusion film forming conditions include an extrusion temperature of 100 ° C. to 160 ° C. and an extrusion pressure of 2 MPa to 50 MPa. From the viewpoint of setting the melting point of the polyethylene component to be equal to or higher than the melting point of the polyethylene component while suppressing the decomposition of the foaming agent component, the extrusion temperature is preferably 110 ° C to 150 ° C, more preferably 120 ° C to 140 ° C. From the viewpoint of extrusion stability, the extrusion pressure is preferably 3 MPa to 40 MPa, more preferably 3 MPa to 30 MPa.

  Although the thickness of a resin sheet can be suitably set according to a use, it can be 50 micrometers-200 micrometers, for example, if it is a foam wallpaper application.

  The manufacturing method of the resin sheet which concerns on this embodiment may further be equipped with the bridge | crosslinking process which bridge | crosslinks part or all of the resin part contained in the resin sheet mentioned above. Examples of the crosslinking treatment include heat treatment such as electron beam irradiation treatment and superheated steam treatment. When the resin composition contains the silane crosslinkable resin, superheated steam treatment and water crosslinking treatment can be performed.

  In the electron beam irradiation treatment, for example, the resin sheet can be subjected to crosslinking treatment by irradiating an electron beam from one side or both sides of the formed resin sheet. Although the electron beam irradiation conditions depend on the thickness of the foamed resin layer, an acceleration voltage of 150 kV to 300 kV and an irradiation dose of 10 kGy to 100 kGy are preferable. If the acceleration voltage is within the above range, it becomes easy to perform desired crosslinking on the resin sheet while suppressing yellowing of the resin sheet and changes in mechanical properties.

  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 resin sheet is arranged in a superheated steam atmosphere and the superheated steam is brought into contact with the resin sheet. 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.

  The crosslinking treatment of the resin sheet may be performed on the resin composition formed into a film, or may be performed after forming a laminated sheet to be described later.

[Production method of laminated sheet]
The manufacturing method of the lamination sheet which concerns on this embodiment is equipped with the said resin sheet formation process and the lamination sheet formation process of laminating | stacking a resin sheet on a base material and obtaining a lamination sheet.

  The laminating method is not particularly limited, and examples thereof include a method in which a resin sheet and a base material 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 performing pressure bonding using superheated steam, it becomes possible to laminate on the base material while maintaining the molten state of the surface of the resin sheet by superheated steam, and the leveling effect makes it possible to laminate the surface of the base material to be adhered. It is possible to suppress the unevenness from being transferred to the resin sheet. Moreover, when a resin sheet contains a silane crosslinkable resin, a silane crosslinkable resin can be bridge | crosslinked efficiently by superheated steam.

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 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 .

  Further, from the viewpoint of improving the adhesion between the base material and the resin sheet, the surface on the side of the base material where the resin sheet is provided is subjected to easy adhesion processing such as corona discharge treatment, plasma treatment, ozone treatment, etc. Alternatively, an easy adhesion treatment layer formed from an acrylic-butyl copolymer, polyurethane composed of isocyanate and polyol, or the like may be provided.

  The method for producing a laminated sheet according to the present embodiment includes a crosslinking step for crosslinking a part or all of the resin contained in the resin sheet before or during lamination on the substrate, or the resin sheet in the laminated sheet. A cross-linking step of cross-linking a part or all of the resin component may be further provided. The crosslinking treatment can be the same as the method described in the method for producing the 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.

[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 foam wallpaper includes the resin sheet forming step, the laminated sheet forming step, and a foaming step of forming a foamed resin layer by foaming a foaming agent contained in the resin sheet in the laminated sheet. It can be obtained by a wallpaper manufacturing method.

  Foaming of the foaming agent can be performed by heating the resin sheet. The heating conditions can be appropriately set depending on the components constituting the resin sheet, and are not particularly limited. However, heating is preferably performed at 160 ° C. to 280 ° C. for 10 seconds to 120 seconds, and 220 ° C. to 240 ° C. at 20 ° C. It is more preferable to heat for 2 seconds to 40 seconds, and further more preferable to heat at 220 ° C. for 40 seconds.

  The method for producing foam wallpaper according to the present embodiment is included in a resin sheet in a cross-linking step of cross-linking part or all of a resin content contained in a resin sheet before or during lamination on a base material, or a laminated sheet. A cross-linking step of cross-linking a part or all of the resin component may be further provided. The crosslinking treatment can be the same as the method described in the method for producing the 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 a foamed resin layer may be provided. An uneven | corrugated shape formation process can be equipped after the said foaming process, for example. The method of providing the uneven shape is not particularly limited. For example, by using heat at the time of superheated 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.

[Production of foam wallpaper]
(Examples 1-2, Comparative Examples 1-2)
Using a T-die having a coat hanger type manifold, using a barrier type screw with a screw diameter (D) of 65 mm and L / D = 32, the composition shown in Table 1 (the numerical values in the table indicate parts by mass) A resin composition having a thickness of 100 μm was formed at an extrusion temperature of 125 ° C. to obtain resin sheets, respectively.

  Each of the resin sheets was irradiated with an electron beam at an acceleration voltage of 200 kV and an irradiation dose of 50 kGy to crosslink the resin component.

Next, on the backing paper (KJ Special Paper Co., Ltd., WK-6651HT, weight 65 g / cm ² ), the resin sheets formed in Examples and Comparative Examples were placed, and the press pressure was applied with a hot press heated at 110 ° C. The laminate sheet was obtained by pressing and heat-sealing for 2 minutes under the condition of 5 MPa.

  After the corona discharge treatment was performed on the resin sheet side surface of the obtained laminated sheet, a fabric pattern was printed using a water-based ink (Daiichi Seika Kogyo Co., Ltd., Hydrick WP) with a gravure printing machine. Next, each laminated sheet was heated in an oven at 240 ° C. for 25 seconds to foam the foaming agent, thereby producing a foamed wallpaper.

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

[Low density polyethylene]
Resin A: Novatec LD LC604 (manufactured by Nippon Polyethylene Co., Ltd., trade name, density = 0.918 g / cm ³ )

[Ultra low density polyethylene]
Resin B: TAFMER DF140 (Mitsui Chemicals, trade name, density = 0.905 g / cm ³ )

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

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

Foaming agent: VINYHALL AC # 3C-2K (manufactured by Eiwa Kasei Kogyo Co., Ltd., trade name)

Foaming aid A: Z-46 (manufactured by Sakai Chemical Co., Ltd., trade name, zinc p-tert-butylbenzoate)
Foaming aid B: Zinc benzoate (manufactured by Junsei Chemical Co., Ltd.)
Foaming aid C: ADK STAB AP-546 (manufactured by ADEKA, trade name, zinc stearate)

Lubricant: ADK STAB AP-546 (manufactured by ADEKA, trade name, zinc stearate)

[Evaluation of foam wallpaper]
About the produced foamed wallpaper, the expansion ratio and the adhesion of ink were evaluated according to the following method.

(Foaming ratio)
The thickness (a) of the dried foamed resin layer before foaming was measured and used as the initial value. Next, the thickness (b) of the foamed resin layer of the foamed wallpaper after foaming in the foaming furnace was measured, and (b) / (a) was calculated as the foaming ratio. The results are shown in Table 2.

(Ink adhesion)
The adhesion test of the picture layer by a tape (Nichiban Co., Ltd., CT-24) was performed on the laminated sheet on which the textile pattern was printed. Regarding adhesion, “◎” indicates that the pattern layer remains 90% or more compared to before the test, “◯” indicates that the pattern layer is 80% or more and less than 90%, and “o” indicates that the pattern layer is 60% or more and less than 80%. “Δ” and less than 60% were evaluated as “x”. The results are shown in Table 2.

[Evaluation of laminated sheet]
In the same manner as described above, laminated sheets of Examples 1-2 and Comparative Examples 1-2 were obtained. About these laminated sheets, according to the following method, the wettability after a corona treatment and the contact angle with respect to ink were evaluated. The results are shown in Table 2.

(Wettability)
Corona discharge treatment was applied to the resin sheet side surface of the laminated sheet. The surface subjected to the corona discharge treatment was tested as described in JIS K6768 using a mixed liquid for wet tension test (manufactured by Wako Pure Chemical Industries, Ltd., mixed liquid for wet tension test No. 30 to No. 42), The wetting tension (mN / m = N / mm) of the resin sheet was measured.

(Contact angle)
The contact angle was measured using a portable contact angle meter PG-3 manufactured by Matsubo Co., Ltd., and the contact angle with respect to hydric ink (manufactured by Dainichi Seika Kogyo Co., Ltd., Hydrick WP).

Claims (10)

A resin composition for forming the foamed resin layer of a foam wallpaper comprising a base material and a foamed resin layer provided on the base material,
Including a filler, a foaming agent, a foaming aid, and a resin component;
The resin composition in which the said foaming adjuvant contains the aromatic carboxylic acid metal salt which has a secondary or more alkyl group or cycloalkyl group in an aromatic ring.   The resin composition according to claim 1, wherein the resin component includes a non-chlorine thermoplastic resin.   The resin composition according to claim 1 or 2, wherein the resin component includes at least an ethylene homopolymer or a copolymer of ethylene and another olefin.   The resin composition according to any one of claims 1 to 3, wherein the content of the aromatic carboxylic acid metal salt is in the range of 50 to 100 parts by mass with respect to 100 parts by mass of the foaming agent.   5. The resin composition according to claim 1, wherein the content of the aromatic carboxylic acid metal salt is in the range of 1 to 10 parts by mass with respect to 100 parts by mass of the resin content.   The manufacturing method of a resin sheet provided with the resin sheet formation process of forming a resin sheet by carrying out extrusion film-forming of the resin composition as described in any one of Claims 1-5. A resin sheet forming step of forming a resin sheet by extrusion-forming the resin composition according to any one of claims 1 to 5;
A laminated sheet forming step of obtaining a laminated sheet by laminating the resin sheet on a base material.   Cross-linking step of cross-linking part or all of the resin contained in the resin sheet before or during lamination on the substrate, or part of the resin contained in the resin sheet in the laminated sheet Or the manufacturing method of the lamination sheet of Claim 7 further equipped with the bridge | crosslinking process which bridge | crosslinks all. A foamed wallpaper manufacturing method comprising: a base material; and a foamed resin layer provided on the base material,
A resin sheet forming step of forming a resin sheet by extrusion-forming the resin composition according to any one of claims 1 to 5;
A laminated sheet forming step of obtaining a laminated sheet by laminating the resin sheet on a substrate,
A foaming wallpaper manufacturing method comprising: a foaming step of forming a foamed resin layer by foaming the foaming agent contained in the resin sheet in the laminated sheet.   Cross-linking step of cross-linking part or all of the resin contained in the resin sheet before or during lamination on the substrate, or part of the resin contained in the resin sheet in the laminated sheet Or the manufacturing method of the foam wallpaper of Claim 9 further equipped with the bridge | crosslinking process which bridge | crosslinks all.