JP6728872B2 - Resin composition, method for producing resin sheet, method for producing laminated sheet, and method for producing foamed wallpaper - Google Patents

Description

The present invention relates to a resin composition, a method for producing a resin sheet, a method for producing a laminated sheet, and a method for producing foamed wallpaper. More specifically, the present invention relates to a resin composition that can be used for wall decoration of buildings such as detached houses, collective housing, shops, and office buildings, as well as a method for producing a resin sheet, a laminated sheet, and a foamed wallpaper.

As a wallpaper used for the wall decoration of a building, a vinyl chloride wallpaper in which a resin layer of a vinyl chloride resin is provided on a paper base material is widely used. In recent years, in consideration of the environment, a halogen-free resin such as an ethylene-vinyl acetate copolymer has been used (see, for example, Patent Documents 1 and 2 below).

As a method for producing these foamed wallpapers, first, a resin composition containing a foaming agent is melt extrusion coated and laminated on a substrate, or sheeting is separately performed by a T-die extrusion method, and then dry lamination or By laminating the base materials by thermal lamination, a laminated sheet having a resin sheet provided on the base materials is obtained. Then, if necessary, the resin sheet having the surface printed thereon is heated to decompose and foam the foaming agent. These methods are advantageous in production efficiency as compared with the method of coating and drying the resin composition on the substrate.

The resin sheet for foamed wallpaper is subjected to a crosslinking treatment with an electron beam or the like in order to adjust the physical properties so that a sufficient expansion ratio can be obtained when foamed, and a good foaming state in which outgassing is not noticeable is obtained. (See, for example, Patent Document 3 below). However, electron beam irradiation has a problem in manufacturing cost such that the paper base material may be yellowed and the electron beam irradiation apparatus is expensive.

JP-A-6-47875 JP, 2001-347611, A Patent No. 3923969

The present inventors have conducted a study on a resin sheet that can be crosslinked by means other than an electron beam, and a resin sheet containing a silane crosslinkable resin can be sufficiently crosslinked by heat or moisture, resulting in a good foaming state. It was found that it can be formed. On the other hand, it was also found by the study by the present inventors that a gel may be generated when a resin composition containing a silane crosslinkable resin is extrusion-molded.

The present invention has been made in view of the above circumstances, and uses a resin composition that can be cross-linked by heat or moisture and is less likely to cause gelation even when extrusion-molded, and the resin composition is used. It is an object to provide a method for producing a resin sheet, a method for producing a laminated sheet, and a method for producing a foamed wallpaper.

That is, the present invention 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, which comprises a foaming agent and a filler. And a resin component containing a silane crosslinkable resin having a melting point of 70° C. or higher.

Since the resin composition of the present invention contains the above-mentioned specific silane crosslinkable resin, it can be crosslinked by heat or moisture, and gel is less likely to be generated even when it is extrusion molded. According to the resin composition of the present invention, a resin sheet having a sufficiently small amount of gel and capable of being crosslinked by heat or moisture can be obtained by extrusion molding. The reason why such an effect is obtained is that a silane crosslinkable resin having a melting point of 70° C. or higher is unlikely to be in an excessively molten state during extrusion molding, and the crosslinking reaction proceeds due to excessive heat from a cylinder or the like. The present inventors presume that this was sufficiently suppressed.

In addition, the resin sheet molded from the resin composition of the present invention is unlikely to change the crosslinked state after the crosslinking treatment, and has a good foaming state even when a storage period is provided before the foaming step. A foamed wallpaper can be stably obtained.

The resin component preferably further contains a polyolefin resin. By using such a resin component, the flexibility of the resin can be improved, and it becomes easy to realize a foamed wallpaper having a foamed resin layer in a good foamed state and having excellent workability.

The present invention also provides a method for producing a resin sheet, which comprises a resin sheet forming step of forming a resin sheet by extruding the resin composition according to the present invention.

The present invention also provides a method for producing a laminated sheet, comprising a laminated sheet forming step of obtaining a laminated sheet by laminating a resin sheet obtained by the method for producing a resin sheet according to the present invention on a substrate.

The manufacturing method of the laminated sheet, a crosslinking step of crosslinking a part or all of the resin component contained in the resin sheet before or during lamination on the substrate, or the resin component contained in the resin sheet in the laminated sheet. A cross-linking step of cross-linking a part or the whole may be further provided.

The cross-linking is preferably performed using superheated steam. By carrying out the cross-linking reaction using superheated steam, the reaction efficiency of the cross-linking reaction can be increased, and it becomes possible to efficiently produce a laminated sheet having desired properties.

Further, the present invention is a method for producing a foamed wallpaper comprising a substrate and a foamed resin layer provided on the substrate, wherein a laminated sheet is prepared by the method for producing a laminated sheet according to the present invention. Provided is a method for producing a foamed wallpaper, which comprises a foaming step of forming a foamed resin layer by foaming a foaming agent contained in the laminated sheet.

According to the present invention, it is possible to crosslink by heat and moisture, and a resin composition in which gel is less likely to occur even when extrusion-molded, a method for producing a resin sheet using the resin composition, and a laminated sheet A manufacturing method and a manufacturing method of a foam wallpaper can be provided.

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

Hereinafter, each component contained in the resin composition will be described in more detail.

<Foaming agent>
Examples of the foaming agent according to the present embodiment include azo foaming agents such as azodicarbonamide, hydrazide foaming agents such as p-toluenesulfonylhydrazide, and nitroso foaming agents such as N,N′-dinitrosopentamethylenetetramine. And the like. These can be used alone or in combination of two or more. The content of the foaming agent is not particularly limited, but the total amount thereof is preferably 2 to 30 mass% based on the total amount of the resin composition. When the content of the foaming agent is in the above range, it is possible to suppress yellowing caused by the foaming agent remaining in the foamed wallpaper after foaming, and it is possible to produce a foamed wallpaper having good compression recovery and touch. ..

As the foaming agent, for example, a commercially available product such as VINIHOL AC#3C-K2 (produced by Eiwa Kasei Co., Ltd., azodicarbonamide-based foaming agent) can be used.

<Filler>
Examples of the filler include inorganic fillers and organic fillers. Examples of the inorganic filler include calcium carbonate and titanium dioxide, and 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, and 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 70% by mass based on the total amount of the resin composition. Reasons for adding the filler include ensuring the concealing property of the foamed wallpaper, reducing the calories burned per unit area, and reducing the manufacturing cost by increasing the bulk, but the content of the filler does not affect the total amount of the resin composition. When the content is 10 to 70% by mass as a standard, it is possible to produce a foamed wallpaper that has a low burning calorie while maintaining a good hiding property as a foamed wallpaper and that has a low manufacturing cost.

As the filler, for example, commercially available products such as Softon 1000 (manufactured by Bihoku Powder Chemical Co., Ltd., calcium carbonate), TYPEK CR-60-2, TYPEK CR-60 (above, titanium dioxide manufactured by Ishihara Sangyo Co., Ltd.) and the like. Can be used.

<resin content>
Examples of the resin component include silane crosslinkable resin and polyolefin resin.

As the silane crosslinkable resin, for example, a silane crosslinkable polyolefin resin or the like can be used. Examples of the silane crosslinkable polyolefin-based resin include resins in which a hydrolyzable silyl group is mainly introduced into a side chain of a polyolefin-based polymer as a matrix. As such a resin, for example, a resin obtained by introducing a hydrolyzable silyl group into a side chain of a polymer such as a low density polyethylene type, a high density polyethylene type, an ethylene-vinyl acetate copolymer type, a polypropylene type and the like can be mentioned. .. Crosslinking is carried out by hydrolysis of the substituted silyl group. A polyolefin resin having the silyl group at the terminal may be included.

The silane crosslinkable polyolefin resin is a method of randomly copolymerizing a monomer of a polyolefin polymer and a silane compound having an ethylenically unsaturated group or an epoxy group in a container, or a peroxide of a melt of the polyolefin polymer. Can be obtained by a method of graft-copolymerizing the above silane compound with. Here, as the polyolefin-based polymer as a matrix, one kind of ethylene homopolymer or a copolymer of ethylene and another olefin described later can be used alone or in combination of two or more kinds. Further, as the base polyolefin-based resin, the above-mentioned polyolefin-based resin and a resin different from the above-mentioned polyolefin-based resin may be used in combination as long as mixing or dispersion of the resins is allowed. The degree of mixing or dispersion varies greatly depending on the type of extruder used, and an appropriate compatibilizer can also be used. Therefore, the combined resins cannot be unconditionally classified, but the same kind of resin is preferable.

Examples of the silane compound having an ethylenically unsaturated group include a silane compound having a vinyl group, a silane compound having an acryloyl group, and a silane compound having a methacryloyl group. Examples of the silane compound having a vinyl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentyloxysilane, vinyltriphenoxysilane, vinyltribenzyloxy. Examples thereof include silane, vinyl trimethylenedioxysilane, vinyltriethylenedioxysilane, vinyltripropionyloxysilane, vinyltriacetoxysilane, and vinyltricarboxysilane. Examples of the silane compound having an acryloyl group include 3-acryloxypropyltrimethoxysilane. Examples of the silane compound having a methacryloyl group include 3-methacryloxypropylmethyldimethoxysilane.

Examples of the silane compound having an epoxy group include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and 3-glycidoxypropylmethyldimethoxysilane.

The resin composition according to the present embodiment contains a silane crosslinkable resin having a melting point of 70° C. or higher. A silane crosslinkable resin having a melting point of 70° C. or higher is unlikely to be in an excessively melted state during extrusion molding, and suppresses the progress of a crosslinking reaction (silane coupling reaction) due to excessive heat from a cylinder or the like. It is thought to be done. By containing such a silane crosslinkable resin, the resin composition according to the present embodiment can obtain a resin sheet having a sufficiently small amount of gel and capable of being crosslinked by heat or moisture even when extrusion-molded. You can From this point of view, the lower limit of the melting point of the silane crosslinkable resin is preferably 100° C. or higher, and more preferably 110° C. or higher. On the other hand, the upper limit of the melting point of the silane crosslinkable resin is not particularly limited, but may be, for example, 200° C. or lower, 150° C. or lower.

The melting point of the silane crosslinkable resin can be adjusted by, for example, the type of the olefin-based monomer used in the copolymerization. Further, as the silane crosslinkable resin having a melting point of 70° C. or higher, for example, commercially available products such as Rinklon HM600A (manufactured by Mitsubishi Chemical Corporation) can be used.

The content of the silane crosslinkable resin having a melting point of 70° C. or higher in the resin composition according to the present embodiment is not particularly limited, but the molding stability and the crosslinkability such as generation of gel and surface roughness are high. From the viewpoint of achieving both levels, the amount is preferably 1 to 40% by mass, more preferably 10 to 30% by mass, and further preferably 10 to 20% by mass, based on the total amount of the resin composition.

Further, the content of the silyl group in the silane crosslinkable resin having a melting point of 70° C. or higher in the resin composition according to the present embodiment is preferably 0.1 to 5 mass% based on the silane crosslinkable resin, and 0 0.5-3 mass% is more preferable, and 1-2 mass% is still more preferable.

The resin component according to the present embodiment preferably further contains a polyolefin resin in addition to the silane crosslinkable resin having a melting point of 70° C. or higher.

Examples of the polyolefin resin include ethylene homopolymers and copolymers of ethylene and other olefins. Ethylene homopolymers and copolymers of ethylene and other olefins are nonpolar non-halogen thermoplastic resins, and by using these, ethylene-methyl methacrylate copolymer resin, ethylene-vinyl acetate copolymer resin. As compared with the case where a resin and a polar resin such as an ionomer resin are used, an increase in the viscosity when the amount of the filler is increased is suppressed, so that a high-quality wallpaper can be stably produced.

Examples of the ethylene homopolymer include low density polyethylene synthesized by the high pressure method and high density polyethylene containing no comonomer synthesized by the medium and low pressure method. Of 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), etc. 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 at a higher temperature when molding the resin, and the foaming agent can be prevented from decomposing during molding. On the other hand, when the melting point is 50° C. or higher, the thermal durability in actual use is easily obtained. The MFR is preferably 3 to 150, more preferably 4 to 100. When the MFR is 3 or more, shearing heat generated during molding can be suppressed, the processing temperature can be easily controlled, and decomposition of the foaming agent during molding can be suppressed. On the other hand, when the MFR is 150 or less, the mechanical strength of the produced foam wallpaper is maintained, and a layer having excellent workability and durability is easily formed.

As the low-density polyethylene, for example, commercially available products such as Novatec LD LC802A, Novatec LD LC604, Novatec LD LC600A (all manufactured by Nippon Polyethylene Co., Ltd.), and Ube Polyethylene J2516 (manufactured by Ube Maruzen Polyethylene Co., Ltd.) can be used.

High density polyethylene, for example, those density is largely 0.960 g / cm ³ or less in the range from 0.940 g / cm ^3. The density of high-density polyethylene is preferably at 0.945 g / cm ³ or more 0.955 g / cm ³ or less. The molecular weight, melting point, melt flow rate (MFR), etc. of the high-density polyethylene are not particularly limited, but the melting point is preferably 120°C to 150°C, more preferably 130°C to 150°C. When the melting point is 150° C. or lower, it is not necessary to melt the resin at a higher temperature when molding the resin, and it is possible to suppress decomposition of the foaming agent during molding. On the other hand, when the melting point is 120° C. or higher, it becomes easy to obtain thermal durability in actual use. The MFR is preferably 3 to 150, more preferably 4 to 100. When the MFR is 3 or more, it is possible to suppress shear heat generation during molding, facilitate control of processing temperature, and suppress decomposition of the foaming agent during molding. On the other hand, when the MFR is 150 or less, the mechanical strength of the produced foamed wallpaper is maintained, and a layer having excellent workability and durability is easily formed.

As the high-density polyethylene, for example, commercially available products such as Novatec HD HJ490 (manufactured by Nippon Polyethylene Co., Ltd.), M6910 (manufactured by Keiyo Polyethylene Co., Ltd.) and Suntec J311 (manufactured by Asahi Kasei Chemicals Co., Ltd.) can be used.

Examples of copolymers of ethylene and other olefins include linear low-density polyethylene, ultra-low-density polyethylene, and high-density polyethylene obtained by copolymerization with comonomers. Alternatively, two or more kinds can be used in combination. Among them, 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 further 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 /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. When the melting point is 100° C. or less, it is not necessary to melt the resin at a higher temperature when molding the resin, and the foaming agent can be prevented from decomposing during molding. On the other hand, when the melting point is 50° C. or higher, the thermal durability in actual use is easily obtained. The MFR is preferably 3 to 150, more preferably 4 to 100. When the MFR is 3 or more, shearing heat generated during molding can be suppressed, the processing temperature can be easily controlled, and decomposition of the foaming agent during molding can be suppressed. On the other hand, when the MFR is 150 or less, the mechanical strength of the produced foam wallpaper is maintained, and a layer having excellent workability and durability is easily formed.

Examples of ultra-low density polyethylene include Tuffmer DF140, DF940, DF7350 (above, manufactured by Mitsui Chemicals, Inc.), Kernel KJ640T (manufactured by Nippon Polyethylene Co., Ltd.), Excellen FX CX5508 (manufactured by Sumitomo Chemical Co., Ltd.), Engage 8400/8407. Commercially available products such as (manufactured by Dow Chemical Co.) and Evolue P SP90100 (manufactured by Prime Polymer Co., Ltd.) can be used.

When the resin component according to the present embodiment further contains the above polyolefin resin, the total amount thereof is preferably 10 to 80% by mass, and preferably 20 to 70% by mass, based on the total amount of the resin composition. It is more preferable that the amount is 40 to 70% by mass.

Further, the resin component according to the present embodiment preferably contains ultra low density polyethylene as the polyolefin resin. In this case, the content of the ultra low density polyethylene is preferably 10 to 100% by mass, more preferably 10 to 90% by mass, and 30 to 90% by mass based on the total amount of the polyolefin resin. It is more preferable that the amount is 30 to 80% by mass.

Further, the resin component according to the present embodiment more preferably contains low density polyethylene and/or high density polyethylene in addition to the ultra low density polyethylene as the polyolefin resin. In this case, the total content of the low-density polyethylene and/or the high-density polyethylene is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, based on the total amount of the polyolefin resin. It is more preferably 40 to 60% by mass.

When the resin component according to the present embodiment further contains the polyolefin resin, the polyolefin resin has a difference in melting point between the polyolefin resin and the above-mentioned silane crosslinkable resin of 30° C. or less. Is preferably included. By including such a polyolefin-based resin, the compatibility with the silane crosslinkable resin is improved, and a resin for producing a high-quality foamed wallpaper, which is more effectively provided with a good expansion ratio and a good bubble state. You can get a sheet. From such a viewpoint, the difference in melting point is more preferably 10° C. or less.

In addition, the resin component according to the present embodiment may include a silane crosslinkable resin other than the above-mentioned silane crosslinkable resin having a melting point of 70° C. or higher within a range that does not impair the effects of the present invention. When such a silane crosslinkable resin is contained, its content is preferably 30% by mass or less based on the total amount of the silane crosslinkable resin contained in the resin composition. From the viewpoint of sufficiently exerting the effects of the present invention, it is more preferable not to include such a silane crosslinkable resin.

Further, the resin composition according to the present embodiment may be colored by adding a pigment or the like, if necessary. The coloring by the addition of the 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 amount of the pigment added is preferably 5 to 50% by mass, more preferably 10 to 30% by mass, based on the total amount of the resin composition.

In addition, known additives such as flame retardants, cell regulators, stabilizers, lubricants, foaming aids, silane crosslinking aids and the like can be used in the resin composition, if necessary.

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

Examples of the cell adjusting agent include acrylic acid ester-based resins and methacrylic acid ester-based resins.

Examples of the stabilizer include radical scavengers such as amine-based antioxidants and hindered amine-based light stabilizers, phosphorus-based and sulfur-based peroxide decomposers, and phenol-based antioxidants and other heat stabilizers. To be

Examples of the lubricant include fatty acid-based lubricants such as stearic acid and lauric acid, fatty acid amide-based substances such as stearic acid amide and oleic acid amide, and metal soap-based lubricants such as zinc stearate, calcium laurate, and zinc octylate. .. As the lubricant, for example, commercially available products such as ADEKA STAB AP-546 and ADEKA STAB OF-101 (above, manufactured by ADEKA Corporation) can be used.

Examples of the foaming aid include urea-based lubricants, zinc chloride, zinc oxide, and the like, in addition to the metal soap-based lubricants described above.

Examples of the silane crosslinking aid include tin-based crosslinking aids such as dioctyltin dilaurate.

[Resin sheet manufacturing method]
The method for producing a resin sheet according to the present embodiment includes a resin sheet forming step of forming a resin sheet by extruding the resin composition according to the present embodiment described above.

Examples of the extrusion molding method include T-die extrusion method, T-die extrusion simultaneous lamination method, T-die extrusion tandem lamination method, circular die extrusion method, circular die inflation extrusion method and the like.

The resin sheet can be manufactured by a known molding method such as injection molding, press molding, blow molding, calendar molding, coating molding, cast molding, dipping molding, vacuum molding and transfer molding, in addition to extrusion molding.

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

The extrusion molding conditions include an extrusion temperature of 100 to 160° C. and an extrusion pressure of 2 to 50 MPa. The extrusion temperature is preferably 110 to 150° C., and more preferably 120 to 140° C., from the viewpoint of suppressing the decomposition of the foaming agent component and increasing the melting point of the resin component or higher. From the viewpoint of extrusion stability, the extrusion pressure is preferably 3 to 40 MPa, more preferably 3 to 30 MPa.

The thickness of the resin sheet can be appropriately set according to the application, and for example, in the case of use as a foam wallpaper, it can be set to 50 to 200 μm.

The method for producing a resin sheet according to this embodiment may further include a crosslinking step of crosslinking a part or all of the resin component contained in the resin sheet described above. Examples of the cross-linking treatment include superheated steam treatment and water cross-linking treatment. From the viewpoint that the reaction efficiency of the cross-linking reaction can be increased and a resin sheet having desired characteristics can be efficiently produced, Steam treatment is preferred.

Examples of the superheated steam treatment include a method of performing superheated steam (also referred to as superheated steam) for 20 seconds to 15 minutes in an environment of 130 to 280°C. Examples of the superheated steam treatment include 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, the method of carrying out water-crosslinking by curing for 1 day to 1 month in a temperature range of 40 to 70° C. in an environment of humidity of 60% or more, and specifically 40° C. 90 %, and a method of water-crosslinking is performed.

The cross-linking treatment of the resin sheet may be performed on the molded resin composition, or may be performed after forming the laminated sheet described below.

[Manufacturing method of laminated sheet]
The method for manufacturing a laminated sheet according to this embodiment includes a laminated sheet forming step of laminating a resin sheet obtained in the resin sheet forming step on a base material to obtain a laminated sheet.

The laminating method is not particularly limited, and examples thereof include a method in which the resin sheet and the base material are thermocompression-bonded by using a heat press machine, a method in which pressure-bonding is performed by 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 the superheated steam, and by the leveling effect, the surface of the base material to be adhered It is possible to prevent the unevenness from being transferred to the resin sheet. When the resin sheet contains a silane crosslinkable resin, the silane crosslinkable resin can be efficiently crosslinked by superheated steam.

The above-mentioned base material is not particularly limited as long as it is one that has been usually used as a paper base material such as a conventional backing paper for wallpaper. Examples of such a base material include a pulp-based flame-retardant paper impregnated with a water-soluble flame retardant such as guanidine sulfamate and guanidine phosphate, or an inorganic agent such as magnesium carbonate, aluminum hydroxide or magnesium hydroxide. Examples include mixed papers made of inorganic materials. These weighing may be a 50 to 300 g / ^{m 2,} it may be 60 to 160 / ^{m 2.}

From the viewpoint of improving the adhesiveness between the base material and the resin sheet, the surface of the base material on which the resin sheet is provided may be subjected to an easy adhesion treatment such as corona discharge treatment, plasma treatment, or ozone treatment. It may be applied or may be provided with an easy adhesion treatment layer formed of an acrylic-butyl copolymer, polyurethane composed of isocyanate and polyol, or the like.

The method for producing a laminated sheet according to the present embodiment includes a crosslinking step of crosslinking a part or all of the resin component contained in the resin sheet before or during lamination on the substrate, or included in the resin sheet in the laminated sheet. It may further include a crosslinking step of crosslinking a part or all of the resin component. The cross-linking 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, laminating and crosslinking of the silane crosslinkable resin can be simultaneously performed by superheated steam.

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

The 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, but it is preferable to heat at 160 to 280° C. for 10 to 120 seconds, and 220 to 240° C. for 20 to 40 seconds. Heating is more preferable, and heating at 220° C. for 40 seconds is more preferable.

Further, the method for producing a foamed wallpaper according to the present embodiment may include a concavo-convex shape forming step of providing a concavo-convex shape on the surface of the foamed resin layer opposite to the base material. The uneven shape forming step can be provided, for example, after the foaming step. The method for providing the uneven shape is not particularly limited, but, for example, by utilizing the heat at the time of heat foaming, the surface side is the cooling embossing roll, the substrate side is the rubber roll, and two tolls are used. Examples include a method of forming an uneven shape on the surface by nipping (embossing) and cooling. The uneven shape is not particularly limited, but examples thereof include wood grain board conduit groove, stone board surface unevenness, cloth surface texturer, satin finish, grain, hairline, and line groove. These can be appropriately selected according to the purpose, and a plurality of them may be combined.

The method for producing the foamed wallpaper according to the present embodiment may include a printing step of providing the pattern layer and the surface protective layer. The pattern layer and the surface protective layer can be appropriately provided by 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 by using a known printing technique such as gravure coating. The printing process can be provided, for example, before the foaming process. That is, the pattern layer and the surface protection 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 resin sheet]
(Examples 1 to 6, Comparative Examples 1 to 3)
Using a T-die having a coat-hanger type manipulator, a flight screw with a dull mage having a screw diameter (D) of 15 mm and L/D (screw length divided by the screw diameter)=25 is shown in Table 1. A resin composition having a composition (numerical values in the table indicate parts by mass) was formed into a film having a thickness of 100 μm to obtain a resin sheet. At this time, the extrusion time of the resin composition was set to 60 minutes, the extrusion temperature was set to 115° C. for Examples 1, 3, 4, 6 and Comparative Examples 1 and 3, and Examples 2, 5 and Comparative Example 2 were used. For, the resin sheet was formed at an extrusion temperature of 150°C.

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

[Low density polyethylene]
Resin A: Novatec LD LC802A (manufactured by Nippon Polyethylene Co., Ltd., trade name, density=0.917 g/cm ³ , MFR=27, melting point=106° C.)

[High density polyethylene]
Resin B: Novatec HD HJ490 (manufactured by Nippon Polyethylene Co., Ltd., trade name, density=0.598 g/cm ³ , MFR=20, melting point=133° C.)

[Ultra low density polyethylene]
Resin C: Kernel KJ640T (manufactured by Japan Polyethylene Corporation, trade name, density=0.880 g/cm ³ , MFR=30, melting point=58° C.)

[Silane crosslinkable resin]
Resin D: Low density polyethylene base, silane crosslinkable resin with melting point = 106°C Resin E: High density polyethylene base, silane crosslinkable resin with melting point = 133°C Resin F: Ultra low density polyethylene base, melting point = 60°C A silane crosslinkable resin

[Calcium carbonate]
Filler A: Softon 1000 (trade name, manufactured by Bihoku Kouka Co., Ltd.)

[titanium dioxide]
Filler B: Taipaque CR-60 (trade name, manufactured by Ishihara Sangyo Co., Ltd.)
Foaming agent: Vinylhol AC#3C-K2 (produced by Eiwa Chemical Industry Co., Ltd., trade name, azodicarbonamide-based foaming agent)

Foaming aid: ADEKA STAB OF-101 (made by ADEKA Co., Ltd., trade name)

Silane cross-linking aid: Linkron LZ013 (trade name, manufactured by Mitsubishi Chemical Corporation)

[Evaluation of resin sheet]
With respect to the resin sheets produced in Examples and Comparative Examples, the number of gels was measured by visual measurement. The results are shown in Table 2.

＊１：ゲル多数により計測不可

*1: Cannot be measured due to a large number of gels

[Preparation of foam wallpaper]
On the backing paper (made by KJ special paper, WK-651HT, weight 65 g/m ² ), the resin sheet formed as above was placed, and pressed for 2 minutes under the condition of a press pressure of 5 MPa with a hot press machine heated at 110° C. And heat-sealed to obtain a laminated sheet.

Furthermore, after subjecting the resin sheet side surface to corona discharge treatment, a pattern pattern is printed at 1 g/m ² using a water-based ink (Hydric WP manufactured by Dainichi Seika Kogyo Co., Ltd.) by a gravure printing machine, and gravure coating is performed. A matte surface coating agent (Nisshin Chemical Industry Co., Ltd., Vinibran 890) was applied at 2 g/m ² using a machine (Kurashiki Spinning Co., Ltd., GP-10) to prepare a pre-crosslinking original fabric.

Each of the above pre-crosslinking raw fabrics was placed in a superheated steam furnace having a steam temperature of 140° C. and a superheated steam amount of 60 kg/hour, and sprayed with superheated steam for 5 minutes to crosslink the resin component to obtain a crosslinked laminated sheet. ..

Each of the laminated sheets obtained above was heated in an oven at 220° C. for 40 seconds to foam a foaming agent to prepare a foamed wallpaper. The following performance evaluation was performed on the produced foamed wallpaper. The results of performance evaluation of each foam wallpaper are shown in Table 3. All of the foamed wallpapers had good foamability and good bubble state, and were of practically no problem quality.

<Expansion ratio>
A cross section was taken out with a razor blade, and observed and measured with a microscope (VHX-600 (trade name) manufactured by Keyence Corporation).

<Bubble state>
The cell state was cross-sectioned with a razor blade and the presence or absence of gas escape on the surface was visually confirmed. In addition, when the shape of the cell was uniform to some extent, it was evaluated as “◯”, and when the cell size was large and a huge cell was seen, it was evaluated as “x”. If it is “◯”, it can be said that the bubble state is good.

Claims (8)

A resin composition used for forming a resin sheet for forming the foamed resin layer of a foamed wallpaper comprising a base material and a foamed resin layer provided on the base material,
A foaming agent, a filler, and a resin component containing a silane crosslinkable resin having a melting point of 110° C. or higher and a polyolefin resin,
The polyolefin resin, density including increased 0.960 g / cm ³ or less is high density polyethylene than 0.940 g / cm ^3,
A resin composition for forming the resin sheet by extrusion molding. The polyolefin resin, the density further comprises an ultra low density polyethylene is less than 0.85 g / cm ³ or more 0.91 g / cm ^3, the resin composition of claim 1. The resin composition according to claim 2, wherein the content of the ultra-low density polyethylene is 30 to 80 mass% based on the total amount of the polyolefin resin. A method for producing a resin sheet for a foam wallpaper, comprising a resin sheet forming step of forming a resin sheet by extruding the resin composition according to any one of claims 1 to 3. A method for producing a laminated sheet for foamed wallpaper, comprising a laminated sheet forming step of laminating a resin sheet obtained by the method according to claim 4 on a base material to obtain a laminated sheet. Crosslinking step of crosslinking the said part or all of the tree fat content that is part of the resin sheet before or during lamination is laminated on the substrate, or the resin sheet contained ∎ You can fat content of in the laminated sheet The method for producing a laminated sheet for foamed wallpaper according to claim 5, further comprising a crosslinking step of partially or entirely crosslinking. The method for producing a laminated sheet for foamed wallpaper according to claim 6 , wherein the cross-linking is performed using superheated steam. A method for producing a foamed wallpaper comprising a base material and a foamed resin layer provided on the base material,
A foamed wallpaper comprising a foaming step of preparing a laminated sheet by the method according to claim 5, and foaming the foaming agent contained in the laminated sheet to form a foamed resin layer. Method.