JP6492482B2 - Resin composition, resin sheet, laminated sheet and foamed wallpaper - Google Patents

Description

  The present invention relates to a resin composition, a resin sheet, a laminated sheet, and foamed wallpaper. More specifically, the present invention relates to a foam wallpaper that can be used for decorating a wall of a building such as a detached house, an apartment house, a store, or an office building, and a resin composition, resin sheet, and laminated sheet used therefor.

  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, resins containing no halogen such as ethylene-vinyl acetate copolymer have been used (for example, see Patent Documents 1 to 3 below). A foam wallpaper using a highly versatile polyethylene resin has also been proposed. (For example, see Patent Document 4 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. To obtain a laminated sheet with a resin sheet provided on the substrate, and then heat the resin sheet printed on the surface as necessary to decompose and foam the foaming agent. There is a way to make it. These methods are advantageous in terms of production efficiency as compared with a method of applying and drying a resin composition on a substrate.

Japanese Patent Laid-Open No. 6-47875 JP 2001-347611 A Japanese Patent No. 4552877 Patent No. 4946942

  However, extrusion film formation has a problem that when the resin is melted using a screw, the resin temperature rises due to shear heat generation, and the foaming agent is easily decomposed inside the extruder. When an ethylene-vinyl acetate copolymer is used, there is a further concern about corrosion of the extruder, excessive thickening due to a combination of a polar compound and an inorganic filler, and the like.

  On the other hand, the resin composition for foam wallpaper is required to have a satisfactory foaming state in which a sufficient foaming ratio is obtained when the formed resin sheet is foamed and the outgassing is not noticeable. It is done. In addition, although the said patent document 4 discloses evaluation of surface hardness, curl resistance, and crack resistance, nothing is mentioned about foamability.

  The present invention has been made in view of the above circumstances, and is a resin that can obtain a resin sheet that can achieve both a sufficient foaming ratio and a good foamed state in which outgassing is not noticeable by foaming when foamed. It aims at providing a composition, a resin sheet using the same, a lamination sheet, and a foam wallpaper.

  A method for adjusting the melt viscosity of a resin defined by a melt flow rate (MFR) or the like as a countermeasure against shearing heat generation is known. However, the present inventors have found that even when a resin having the same MFR is used, there is a large difference in foamability of the resin sheet formed by extrusion. Therefore, as a result of further investigation, the present inventors focused on strain hardening of low density polyethylene, and by combining low density polyethylene having specific elongational viscosity characteristics with a resin composition in combination with ultra low density polyethylene. The inventors have found that a resin sheet having good foamability can be formed by extrusion film formation, and have completed the present invention based on this finding.

That is, the present invention is 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, the foaming agent, and a low density A test piece containing polyethylene and ultra-low density polyethylene, which was formed into a thickness of 1 mm by a T-die extruder and cut into a size of 12 mm in length and 12 mm in width, was at a temperature of 120 ° C. and a strain rate. When stretched in the film-forming direction under the condition of 0.1 (/ s), the stretching viscosity from 1 second to 10 seconds after stretching starts is in the range of 1 × 10 ⁵ (Pa · s) or less, and stretching starts Provided is a resin composition having an extension viscosity after 20 seconds greater than the extension viscosity after 10 seconds from the start of elongation and in the range of 1 × 10 ⁵ (Pa · s) or more.

  According to the resin composition of the present invention, it is possible to obtain a resin sheet that can achieve both a sufficient expansion ratio and a good foamed state in which outgassing is not noticeable by foaming.

  In this specification, extrusion film formation means that a material containing a thermoplastic resin is heated and melted using an extruder equipped with a melting screw, and then the molten resin is discharged from a die provided with slit-like gaps, thereby forming a film. This is a method for obtaining a shaped product. Extrusion film formation includes not only a method for producing a film-form product alone, but also a method for directly or once cooling and laminating on a sheet as a substrate.

In the resin composition of the present invention, the density of the ultra-low density polyethylene is preferably 0.875 g / cm ³ or less. In this case, the curl resistance of the foamed wallpaper obtained by foaming the resin sheet obtained by extrusion film formation, the scratch resistance of the foamed resin layer and the high foaming ratio can be balanced at a high level, and the curl resistance is improved. The ease of construction of the foam wallpaper can be improved.

Moreover, it is preferable that the mixture ratio of the said low density polyethylene and the said ultra-low density polyethylene is 60 / 40-90 / 10 by mass ratio. In this case, the curl resistance of the foamed wallpaper obtained by foaming the resin sheet obtained by extrusion film formation, the scratch resistance of the foamed resin layer, and the high foaming ratio can be balanced at a high level. In particular, when the ultra-low density polyethylene is an ultra-low density polyethylene having a density of 0.875 g / cm ³ or less, the above-described effect is easily obtained.

  The resin composition of the present invention can contain a silane crosslinkable resin. In this case, the resin sheet obtained by extrusion film formation can be subjected to a crosslinking treatment by a silane coupling reaction, thereby more reliably suppressing gas escape during foaming, and foaming with uniform and less gas escape from the surface. A resin layer can be formed. Moreover, said crosslinking process can suppress that the paper base yellowing and mechanical strength fall compared with the crosslinking process by an electron beam.

  The resin composition of the present invention contains a first filler having a 50% average particle diameter of 0.2 to 0.3 μm and a second filler having a 50% average particle diameter of 1 to 5 μm. be able to. In this case, the foamed wallpaper obtained by foaming the resin sheet obtained by extrusion film formation can have a more stable foamed state.

  In this specification, the 50% average particle size is a median value when the particle sizes are arranged in order of size. The particle size is measured by a commercially available particle size distribution analyzer.

  The present invention also provides a resin sheet obtained by extrusion film formation of the resin composition according to the present invention. This resin sheet may be subjected to a crosslinking treatment.

  The present invention also provides a laminated sheet comprising a base material and the resin sheet according to the present invention provided on the base material.

  The inventor is also a foam wallpaper comprising a base material and a foamed resin layer provided on the base material, the foaming agent contained in the resin sheet in the laminated sheet according to the invention being foamed The resulting foamed wallpaper is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition which can obtain the resin sheet which can satisfy | fill both a sufficient foaming ratio and the favorable foaming state where gas escape is not conspicuous when it foams by extrusion film formation, Resin sheet using the same A laminated sheet and foamed wallpaper can be provided.

It is a figure which shows the measurement chart of the extensional viscosity of resin A-1.

[Resin composition]
The resin composition according to the present embodiment 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, and a foaming agent , A low-density polyethylene and an ultra-low-density polyethylene, a low-density polyethylene formed into a thickness of 1 mm by a T-die extruder, and a test piece cut to a size of 12 mm in length and 12 mm in width was heated to 120 ° C. When the film is stretched in the film-forming direction at a strain rate of 0.1 (/ s), the elongation viscosity from 1 second to 10 seconds after the start of stretching is in the range of 1 × 10 ⁵ (Pa · s) or less. The extension viscosity at 20 seconds after the start of extension is greater than the extension viscosity at 10 seconds after the start of extension and is in the range of 1 × 10 ⁵ (Pa · s) or more.

  Examples of the foaming agent according to the present embodiment include azo foaming agents such as azodicarbonamide, hydrazide foaming agents such as p-toluenesulfonyl hydrazide, and nitroso foaming agents such as N, N′-dinitrozopentamethylenetetramine. These can be used, and 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.

As the low density polyethylene according to the present embodiment, for example, a polymer having a density in a range of 0.90 to 0.930 g / cm ³ and polymerized by a high pressure method can be used.

  In this embodiment, a low-density polyethylene film is formed into a thickness of 1 mm using a T-die extruder, and a test piece cut into a size of 12 mm in length and 12 mm in width is prepared. This test piece is manufactured by Anton Paar. Using Physica MCR301, by measuring the extension viscosity from 1 second to 20 seconds after the start of stretching when stretched in the film forming direction at a temperature of 120 ° C. and a strain rate of 0.1 (/ s), The low density polyethylene which concerns on embodiment can be selected.

The extension viscosity from 1 second to 10 seconds after the start of extension is in the range of 1 × 10 ⁵ (Pa · s) or less, the extension viscosity after 20 seconds from the start of extension is greater than the extension viscosity after 10 seconds from the start of extension, and By using low-density polyethylene in the range of 1 × 10 ⁵ (Pa · s) or more, it is possible to balance the gas holding force and the expansion force during foaming while maintaining good extrudability such as a T-die. And a high foaming ratio and a good foamed state can be obtained. In addition, since the viscosity in a molten state tends to increase when the elongation viscosity from 1 second after the start of elongation to 10 seconds later exceeds 1 × 10 ⁵ (Pa · s), the resin pressure or The motor load tends to increase, the film-forming stability during sheeting tends to decrease, and it becomes difficult to obtain sufficient productivity. In addition, when the elongation viscosity is smaller than the elongation viscosity after 10 seconds from the start of elongation, or less than 1 × 10 ⁵ (Pa · s) when the elongation is less than 1 × 10 ⁵ (Pa · s). It becomes difficult to suppress the bubble breakage, and it becomes difficult to obtain a sufficient gas holding force, so that the foaming ratio tends to be lowered.

In the present embodiment, from the viewpoint of extrusion stability at the time of film formation, 1 second after the start of elongation when the test piece is stretched in the film-forming direction at a temperature of 120 ° C. and a strain rate of 0.1 (/ s). elongational viscosity of up to 10 seconds after the can, is preferably in the range of ^{10~1 × 10 5 (Pa · s} ), more in the range of ^{1 × 10 2 ~1 × 10 5} (Pa · s) preferable. Also, from the viewpoint of the balance between extrusion stability and foaming stability during film formation, the extension viscosity after 10 seconds from the start of extension is preferably in the range of 1 × 10 ² to 1 × 10 ⁵ (Pa · s). More preferably, it is in the range of 1 × 10 ³ to 1 × 10 ⁵ (Pa · s). Further, from the viewpoint of foaming stability, the extension viscosity after 20 seconds from the start of extension is preferably in the range of 1 × 10 ⁵ to 1 × 10 ⁸ (Pa · s), and 1 × 10 ⁵ to 1 × 10 ^7. More preferably, it is in the range of (Pa · s). In addition, from the viewpoint of the balance between extrusion stability and foaming stability during film formation, the extension viscosity from 10 seconds to 20 seconds after the start of extension is in the range of 1 × 10 ³ to 1 × 10 ⁸ (Pa · s). Preferably, it exists in the range of 1 * 10 < ⁴ > -1 * 10 < ⁷ > (Pa * s). In addition, when the extension viscosity after 20 seconds from the start of extension, or the extension viscosity from 10 to 20 seconds after the start of extension exceeds the above range, the gas holding power tends to be superior to the expansion force, and the expansion ratio is increased. It becomes difficult.

  The low density polyethylene is not particularly limited in terms of its molecular weight, melting point, melt flow rate (MFR), etc., as long as it satisfies the above conditions of elongation viscosity, but the melting point is preferably 90 ° C. to 115 ° C., preferably 100 ° C. to 110 ° C. is more preferable. When the melting point is 115 ° C. or lower, it is not necessary to melt and mold the resin at a higher temperature, and there is little possibility that the foaming agent will decompose during molding. On the other hand, if the melting point is 90 ° C. or higher, sufficient heat durability in actual use can be obtained. The MFR is preferably 8 to 150, more preferably 20 to 50. If the resin has an MFR of 8 or more, shear heat generated during molding can be suppressed, the processing temperature can be easily controlled, and the foaming agent is less likely to decompose 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. Further, in terms of molecular structure, it is desirable to have a branched structure, and a long branched chain is still more desirable. Also, it is desirable that there are many branch points.

  Commercially available products such as Novatec LD LC802A, Novatec LD LC604 (above made by Nippon Polyethylene), Ube Polyethylene J2516 (made by Ube Maruzen Polyethylene) can be used as the low density polyethylene that satisfies the above conditions of elongation viscosity.

  The content of the low density polyethylene in the resin composition according to this embodiment is preferably 10 to 70% by mass and more preferably 30 to 50% by mass based on the total amount of the resin composition.

Examples of the ultra-low density polyethylene according to the present embodiment include ethylene and other olefins having a density in the range of 0.85 to 0.90 (particularly 0.85 to less than 0.90) g / cm ^3. These copolymers can be used. Examples of other olefins include α-olefins having 3 to 20 carbon atoms.

In this embodiment, it is preferable to use ultra-low density polyethylene having a density of 0.875 g / cm ³ or less. In this case, the curl resistance of the foamed wallpaper obtained by foaming the resin sheet obtained by extrusion film formation, the scratch resistance of the foamed resin layer and the high foaming ratio can be balanced at a high level, and the curl resistance is improved. The ease of construction of the foam wallpaper can be improved. In addition, in the ultra-low density polyethylene having a density exceeding 0.875 g / cm ³ , the blending amount necessary for ensuring easy workability tends to increase. On the other hand, in order to maintain fire prevention performance, The amount of low density polyethylene inevitably decreases because of the need to keep the total amount of minutes within a certain range. As a result, the number of long chain branches necessary for obtaining good foaming is reduced, making it difficult to increase the foaming ratio.

  Examples of ultra-low density polyethylene include Tafmer DF7350 (manufactured by Mitsui Chemicals), Kernel KJ-640T (manufactured by Nippon Polyethylene), Excellen FX CX5508 (manufactured by Sumitomo Chemical), Engage 8400/8407 (manufactured by Dow Chemical), Evolue P SP90100 Commercial products such as (made of prime polymer) can be used.

  The content of the ultra-low density polyethylene in the resin composition according to the present embodiment is preferably 5 to 50% by mass and more preferably 10 to 30% by mass based on the total amount of the resin composition.

In the resin composition of the present embodiment, the blending ratio of the low density polyethylene and the ultra low density polyethylene is preferably 60/40 to 90/10 in terms of mass ratio, and is 70/30 to 80/20. It is more preferable. By setting the blending ratio of both in such a range, the curl resistance of the foamed wallpaper obtained by foaming the resin sheet obtained by extrusion film formation, the scratch resistance of the foamed resin layer, and the high foaming ratio are at a high level. Can be balanced. In particular, when the ultra-low density polyethylene is an ultra-low density polyethylene having a density of 0.875 g / cm ³ or less, the above-described effect is easily obtained.

  The resin composition of this embodiment can contain a silane crosslinkable resin. In this case, the resin sheet obtained by extrusion film formation can be subjected to a crosslinking treatment by a silane coupling reaction, thereby more reliably suppressing gas escape during foaming, and foaming with uniform and less gas escape from the surface. A resin layer can be formed. Moreover, said crosslinking process can suppress that the paper base yellowing and mechanical strength fall compared with the crosslinking process by an electron beam.

  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 type, a high density polyethylene type, an ethylene-vinyl acetate copolymer system, or a polypropylene type. . 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 randomly copolymerizing a polyolefin polymer monomer and an ethylenically unsaturated silane compound in a container, 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 used in combination with the polyolefin-based resin and a resin different from the polyolefin-based resin 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 be used. Therefore, the combined resins cannot be generally classified, 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 silane crosslinkable resin in the resin composition according to the present embodiment is preferably 1 to 20% by mass and more preferably 3 to 10% by mass based on the total amount of the resin composition.

  The resin composition of the present embodiment may contain a resin other than the above-described resins as long as the effects of the present invention are not impaired. Such resins include polyolefin resins (polypropylene, polybutene, polymethylpentene, etc.), styrene resins (polystyrene, acrylonitrile / styrene resins, acrylonitrile / butadiene / styrene resins, etc.), ethylene copolymers (ethylene-vinyl acetate copolymers). , Ethylene-methyl methacrylate copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc.). These can be used alone or in combination of two or more.

  The resin composition of this embodiment can contain a filler.

  Examples of the filler 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.

  In this embodiment, it may contain a first filler having a 50% average particle diameter of 0.2 to 0.3 μm and a second filler having a 50% average particle diameter of 1 to 5 μm. preferable. In this case, the foamed wallpaper obtained by foaming the resin sheet obtained by extrusion film formation can have a more stable foamed state. As the first filler, titanium dioxide, white calcium carbonate, zinc oxide, silica, talc and the like can be used. As the second filler, calcium carbonate, mica, talc, zinc oxide, metal powder, carbon black, pearl, barium sulfate, metal oxide, and the like can be used. The blending ratio of the first filler and the second filler is preferably 5/95 to 70/30 for the first filler / second filler from the viewpoint of concealability and scratch resistance. / 80-50 / 50 is more preferable.

  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, a lubricant, a foaming aid, a silane crosslinking aid, can be used for a resin composition as needed.

  Examples of the flame retardant include metal oxide 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, benzotriazole, hydroxyphenyl triazine, and benzophenone. 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.

  Examples of the foaming aid include urea, zinc chloride, zinc oxide and the like in addition to the fatty acid metal salt lubricant.

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

  The resin composition of this embodiment contains a crosslinking aid such as trimethylpropane / trimethacrylate, trimethylpropane / triacrylate, triallyl isocyanurate in order to efficiently crosslink the formed resin sheet. Is preferred.

  As a compounding quantity of the said crosslinking adjuvant, 0.01-5 mass parts is preferable with respect to 100 mass parts of resin components, and 0.1-1.0 mass part is more preferable. Within this range, the effect of adding a crosslinking aid can be sufficiently obtained, and blooming on the resin sheet surface layer can be easily prevented.

[Resin sheet]
The resin sheet according to the present embodiment is formed from the resin composition according to the present embodiment. The resin sheet according to the present embodiment can be obtained, for example, by extrusion film-forming the resin composition according to the present 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.

  The resin sheet according to the present embodiment is produced not only by extrusion molding but also 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. be able to.

  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 to 160 ° C. and an extrusion pressure of 2 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 decomposition of the foaming agent component, the extrusion temperature is preferably 110 to 150 ° C, more preferably 120 to 140 ° C. From the viewpoint of extrusion stability, the extrusion pressure is preferably 3 to 40 MPa, more preferably 3 to 30 MPa.

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

  The 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 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 crosslinked 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 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.

  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.

[Laminated sheet]
The laminated sheet according to the present embodiment includes a base material and the resin sheet provided on the base material. The laminated sheet can be obtained by laminating a resin sheet on a substrate. 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 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 It can suppress that the unevenness | corrugation of is transferred to a 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.

[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, for example, a step of laminating the above-described resin sheet on a substrate to obtain a laminated sheet, and a step of forming a foamed resin layer by foaming a foaming agent contained in the resin sheet. And can be obtained by a 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.

  As another embodiment, the foam wallpaper can be obtained by a method including a step of forming a foamed resin layer by foaming a foaming agent contained in the resin sheet in the laminated sheet.

  Furthermore, in the foamed wallpaper according to the present embodiment, the surface of the foamed resin layer opposite to the base material may have an uneven shape. 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 texture, a satin texture, a grained grain, a hairline, and a straight line groove. Can be selected as appropriate.

  The foamed wallpaper according to the present embodiment may be provided with 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 pattern layer and a surface protective layer can be provided before foaming a 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 1-13, Comparative Examples 1-3)
Using a single screw extruder equipped with an inflation die, a resin composition having the composition shown in Tables 1 and 2 (the numerical values in the table indicate parts by mass) was formed at an extrusion temperature of 130 ° C. and a thickness of 100 μm, Each resin sheet was obtained.

  The resin sheets of Examples 1, 3 to 10 and Comparative Examples 1 to 4 were irradiated with an electron beam at an acceleration voltage of 200 kV and an irradiation dose of 60 kGy to crosslink the polyethylene resin. Further, the resin sheet of Example 2 was aged for 2 days in an environment of a temperature of 40 ° C. and a humidity of 90% to crosslink the silane crosslinkable resin.

Next, on the backing paper (KJ Special Paper, WK-665IHT, weight 65 g / m ² ), the resin sheets formed in Examples and Comparative Examples were placed and pressed for 30 seconds with a hot press heated at 110 ° C. And heat-sealed. Then, it heated for 25 second in 240 degreeC oven, the foaming agent was foamed, and the foaming wallpaper was produced.

[Evaluation of foam wallpaper]
The foamed wallpaper thus produced was evaluated for foaming magnification, surface condition, scratch resistance, and curl resistance according to the following methods.

(Foaming ratio)
The thickness T (μm) of the foamed wallpaper including the backing paper was measured using a thickness meter. From this value, the expansion ratio was calculated by the following formula.
Foaming ratio = [T- (thickness of backing paper)] / (thickness of resin sheet)
[The thickness of the backing paper and the thickness of the resin sheet are each 100 μm]

(Surface condition)
The presence or absence of gas escape from the surface layer was confirmed by visual observation, and evaluated according to the following criteria.
A: No hole is seen on the surface layer.
B: Crater-like holes were confirmed on the surface layer (with gas escape).

(Scratch resistance)
The following scratch resistance test was performed using a Hoffman scratch tester, and the maximum load (g) at which no scratch was observed was confirmed. However, since all of Examples and Comparative Examples include a foamed resin layer, in the evaluation of scratches, the determination was performed by removing the dents.
[Scratch resistance test]
Using a BYK-Gardener Hoffman scratch tester, set the scratch blade (the edge of a 7 mm diameter cylinder) so that it contacts the surface of the specimen at an angle of 45 degrees, and move to pull the scratch blade. And rubbed the surface. At that time, the load applied to the scratch blade was changed, and the maximum load that was not damaged was confirmed.

(Curl resistance)
Curl resistance was evaluated as a criterion for easy workability. Cut the foamed wallpaper into a 10cm square, immerse it in water at room temperature for 1 minute, take it out, measure it again, measure the elongation (only in the direction perpendicular to the fiber direction of the paper substrate), and follow the criteria below evaluated.
S: Elongation exceeds 2 mm (because the foamed resin layer follows the elongation due to swelling of the paper exceeding 2 mm, curling hardly occurs).
A: Elongation amount is 1 to 2 mm (because the foamed resin layer stretches 1 to 2 mm and follows the elongation due to the swelling of the paper, but curls, but does not cause any problem for the implementation).
B: Elongation amount is less than 1 mm (Because the foamed resin layer hardly follows the elongation due to the swelling of the paper, the foamed resin layer is curled greatly with the foamed resin layer inside).

  The following materials were used for each component shown in Tables 1 and 2.

[Low density polyethylene]
Resin A-1: Novatec LD LJ802A (manufactured by Nippon Polyethylene, MFR = 27, density = 0.997)
Resin A-2: Ube polyethylene J2516 (Ube Maruzen polyethylene, MFR = 25, density = 0.916)
Resin A-3: Novatec LD LC604 (manufactured by Nippon Polyethylene, MFR = 8.4, density = 0.918)
Resin A-4: Petrocene 202 (manufactured by Tosoh Corporation, MFR = 22, density = 0.918)
Resin A-5: Ube polyethylene R300 (Ube Maruzen polyethylene, MFR = 0.35, density = 0.920)
Resin A-6: Petrocene 353 (manufactured by Tosoh Corporation, MFR = 145, density = 0.997)

  About Resin A-1 to A-6, the extensional viscosity was measured according to the following method. First, a test piece was prepared by forming low-density polyethylene into a thickness of 1 mm using a T-die extruder (molding at an extrusion temperature of 160 ° C. and a lip opening of 1 mm) and cutting it into a length of 12 mm and a width of 12 mm. Next, using a Physica MCR301 manufactured by Anton Paar, the test piece was stretched in the film forming direction at a temperature of 120 ° C. and a strain rate of 0.1 (/ s) for 20 seconds after the start of stretching. The elongational viscosity until later was measured. The results are shown in the table below. Moreover, the measurement chart at the time of measuring an extensional viscosity about resin A-1 is shown in FIG.

[Ultra low density polyethylene]
Resin B-1: Toughmer DF7350 (Mitsui Chemicals, MFR = 35, density 0.870)
Resin B-2: Kernel KJ-640T (Nippon Polyethylene, MFR = 30, density 0.880)
Resin B-3: Excellen FX CX5508 (manufactured by Sumitomo Chemical Co., Ltd., MFR = 75, density 0.890)

[Other resins]
Silane crosslinkable resin: Linkron XCF710N (Mitsubishi Chemical, low density polyethylene base)

[filler]
Calcium carbonate 1: Softon 1000 (manufactured by Bihoku powdering industry, 50% average particle size 2.2 μm)
Calcium carbonate 2: Softon 3200 (manufactured by Bihoku powdering industry, 50% average particle size 0.7 μm)
Calcium carbonate 3: BF200 (manufactured by Bihoku powdering industry, 50% average particle size 5 μm)
Calcium carbonate 4: BF300 (manufactured by Bihoku powdering industry, 50% average particle size 8 μm)
Titanium dioxide 1: Taipei CR-60 (Ishihara Sangyo, 50% average particle diameter 0.21 μm)
Titanium dioxide 2: Taipei A-220 (Ishihara Sangyo, 50% average particle size 0.16 μm)

[Foaming agent]
Azo-based foaming agent: VINYHALL AC # 3C-K2 (manufactured by Eiwa Chemical Industry Co., Ltd., average particle size 5 μm)

[Foaming aid]
Zinc-based foaming aid: ADK STAB OF101 (made by ADEKA)

[Other additives]
Silane crosslinking aid: LZ013 (Mitsubishi Chemical, polyethylene base)

Claims (13)

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,
A foaming agent, low-density polyethylene, and ultra-low-density polyethylene having a density of 0.875 g / cm ³ or less ,
The content of the low density polyethylene is 10 to 70% by mass based on the total amount of the resin composition,
The content of the ultra-low density polyethylene is 5 to 50% by mass based on the total amount of the resin composition,
The low-density polyethylene was formed into a thickness of 1 mm by a T-die extruder, and a test piece cut into a size of 12 mm in length and 12 mm in width was produced under conditions of a temperature of 120 ° C. and a strain rate of 0.1 (/ s). When stretched in the film direction, the extension viscosity from 1 second to 10 seconds after the start of extension is in the range of 1 × 10 ⁵ (Pa · s) or less, and the extension viscosity after 20 seconds from the start of extension is 10 seconds from the start of extension. A resin composition that is larger than the later extensional viscosity and in the range of 1 × 10 ⁵ (Pa · s) or more. The resin composition according to claim 1, wherein a blending ratio of the low density polyethylene and the ultra low density polyethylene is 60/40 to 90/10 in mass ratio. The resin composition of Claim 1 or 2 containing a silane crosslinkable resin. 50% average particle diameter contains the first filler is 0.2 to 0.3 [mu] m, the second filler 50% average particle diameter of 1 to 5 [mu] m, a, of claim 1-3 The resin composition as described in any one. 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 foaming agent, low density polyethylene, and ultra low density polyethylene,
The content of the low density polyethylene is 10 to 70% by mass based on the total amount of the resin composition,
The content of the ultra-low density polyethylene is 5 to 50% by mass based on the total amount of the resin composition,
The blending ratio of the low density polyethylene and the ultra low density polyethylene is 60/40 to 90/10 in mass ratio,
The low-density polyethylene was formed into a thickness of 1 mm by a T-die extruder, and a test piece cut into a size of 12 mm in length and 12 mm in width was produced under conditions of a temperature of 120 ° C. and a strain rate of 0.1 (/ s). When stretched in the film direction, the stretching viscosity from 1 second to 10 seconds after the start of stretching is 1 × 10 ⁵ (Pa · s) or less, the extension viscosity after 20 seconds from the start of extension is greater than the extension viscosity after 10 seconds from the start of extension, and 1 × 10 ⁵ Resin composition in the range of (Pa · s) or more. The resin composition of Claim 5 containing a silane crosslinkable resin. The first filler having a 50% average particle diameter of 0.2 to 0.3 μm and the second filler having a 50% average particle diameter of 1 to 5 μm are contained in claim 5 or 6. The resin composition as described. 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 foaming agent, low density polyethylene, ultra-low density polyethylene, and a silane crosslinkable resin,
The content of the low density polyethylene is 10 to 70% by mass based on the total amount of the resin composition,
The content of the ultra-low density polyethylene is 5 to 50% by mass based on the total amount of the resin composition,
The low-density polyethylene was formed into a thickness of 1 mm by a T-die extruder, and a test piece cut into a size of 12 mm in length and 12 mm in width was produced under conditions of a temperature of 120 ° C. and a strain rate of 0.1 (/ s). When stretched in the film direction, the stretching viscosity from 1 second to 10 seconds after the start of stretching is 1 × 10 ⁵ (Pa · s) or less, the extension viscosity after 20 seconds from the start of extension is greater than the extension viscosity after 10 seconds from the start of extension, and 1 × 10 ⁵ Resin composition in the range of (Pa · s) or more. The first filler having a 50% average particle diameter of 0.2 to 0.3 μm and the second filler having a 50% average particle diameter of 1 to 5 μm. Resin composition. A resin sheet obtained by extrusion film-forming the resin composition according to any one of claims 1 to 9 . Obtained a tree fat composition by extrusion casting, crosslinking treatment that have been subjected to a resin sheet,
The resin composition is 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 foaming agent, low density polyethylene, and ultra low density polyethylene,
The content of the low density polyethylene is 10 to 70% by mass based on the total amount of the resin composition,
The content of the ultra-low density polyethylene is 5 to 50% by mass based on the total amount of the resin composition,
The low-density polyethylene was formed into a thickness of 1 mm by a T-die extruder, and a test piece cut into a size of 12 mm in length and 12 mm in width was produced under conditions of a temperature of 120 ° C. and a strain rate of 0.1 (/ s). When stretched in the film direction, the extension viscosity from 1 second to 10 seconds after the start of extension is in the range of 1 × 10 ⁵ (Pa · s) or less, and the extension viscosity after 20 seconds from the start of extension is 10 seconds from the start of extension. A resin sheet that is larger than the later extensional viscosity and in the range of 1 × 10 ⁵ (Pa · s) or more. A laminated sheet comprising: a base material; and the resin sheet according to claim 10 or 11 provided on the base material. A foam wallpaper comprising a base material and a foamed resin layer provided on the base material,
The foamed wallpaper obtained by foaming the foaming agent contained in the said resin sheet in the lamination sheet of Claim 12 .

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