JP4810951B2 - Wall decoration sheet - Google Patents

Description

  The present invention relates to a decorative sheet for wall covering.

  Conventionally, as a decorative sheet for wall covering (foamed wallpaper), a sheet-like base material laminated with a foamed resin layer of vinyl chloride resin is known. In recent years, in consideration of the environment, halogen-free resins such as ethylene-vinyl acetate copolymer (hereinafter also referred to as “EVA”) acrylic resin and olefin resin have been used for the foam resin layer (Patent Documents 1 to 3). 3 etc.).

  For example, an emulsion containing acrylic resin and EVA is prepared with a microcapsule-type foaming agent added. After coating and drying on a paper-based substrate, a pattern is printed on the surface, then heated and foamed, and then an embossed plate A foamed wallpaper having an uneven pattern formed on the outermost surface is known.

  Moreover, after forming a foaming agent-containing resin layer comprising a resin composition obtained by adding a pyrolytic foaming agent to EVA on a paper substrate using a T-die extruder, a pattern pattern layer is printed on the surface, and further heated. A foamed wallpaper is known in which an uneven pattern is formed by embossing after foaming.

  By the way, when the resin layer (foamed resin layer / non-foamed resin layer) is mainly composed of EVA, there is a problem that the surface strength (particularly scratch resistance) of the wall covering decorative sheet is insufficient.

  In order to improve the problem, for example, in Patent Document 4, a non-foamed resin layer (surface protective layer) composed of a polyethylene resin having a specific density and thickness is laminated on a foamed resin layer made of an ethylene-based resin. Measures to do are disclosed. It is described that by adopting such a configuration, it is possible to provide a foamed wallpaper having high scratch resistance and less warping (curling).

However, the improved decorative sheet for wall covering has room for further improvement in terms of scratch resistance and curling. This is because they tend to affect the durability and workability in actual use.
Japanese Patent Laid-Open No. 6-47875 JP 2000-255011 A JP 2001-347611 A JP 2004-52371 A

  The present invention mainly provides a decorative sheet for wall covering having a non-foamed resin layer (surface protective layer) containing a polyethylene resin, which has high scratch resistance and curling is suppressed. With a purpose.

  As a result of intensive studies, the present inventor has found that the above object can be achieved when a specific modifier is added to the non-foamed resin layer, and has completed the present invention.

  That is, this invention relates to the following decorative sheet for wall covering.

1. A decorative sheet for wall covering in which at least a foamed resin layer and a non-foamed resin layer are sequentially formed on a paper substrate,
(1) The foamed resin layer is formed by foaming the foaming agent-containing resin layer,
(2) The decorative sheet for wall covering, wherein the non-foamed resin layer has a thickness of 10 to 15 μm and contains a linear low density polyethylene resin and an ethylene-α-olefin copolymer.

  2. The decorative sheet for wall covering according to Item 1, wherein the ethylene-α-olefin copolymer is contained in an amount of 20 to 50% by weight in the non-foamed resin layer.

  3. Item 3. The decorative sheet for wall covering according to Item 1 or 2, wherein the foaming agent-containing resin layer contains an ethylene-vinyl acetate copolymer as a resin component.

  4). Item 4. The decorative sheet for wall covering according to any one of Items 1 to 3, wherein the foaming agent is a pyrolytic foaming agent.

  5. Item 5. The decorative sheet for wall covering according to any one of Items 1 to 4, wherein the foaming agent-containing resin layer comprises an ethylene-vinyl acetate copolymer, an inorganic filler, a pigment, a pyrolytic foaming agent, and a cell regulator.

  6). Item 6. The decorative sheet for wall covering according to any one of Items 1 to 5, wherein at least one of the foamed resin layer and the non-foamed resin layer is resin-crosslinked by electron beam irradiation.

  7). Item 7. The wall covering decorative sheet according to any one of Items 1 to 6, which has an uneven pattern formed by embossing.

The decorative sheet for wall covering of the present invention is a decorative sheet for wall covering in which at least a foamed resin layer and a non-foamed resin layer are sequentially formed on a paper-based substrate,
(1) The foamed resin layer is formed by foaming the foaming agent-containing resin layer,
(2) The non-foamed resin layer is characterized by containing a linear low density polyethylene resin and an ethylene-α olefin copolymer.

  In the decorative sheet for wall covering of the present invention, the non-foamed resin layer (surface protective layer) contains a linear low density polyethylene resin and an ethylene-α-olefin copolymer as resin components, and has high scratch resistance. Curling is suppressed. This is presumably because the linear low-density polyethylene resin effectively acts to develop the scratch resistance, and the ethylene-α-olefin copolymer acts as a modifier that contributes to curl suppression.

  Hereinafter, the wall-dressing decorative sheet will be described for each layer.

The paper-based substrate is not particularly limited as long as it has mechanical strength, heat resistance and the like suitable as a wallpaper substrate, and a fibrous sheet can be generally used.

  Specifically, among fiber sheets, flame retardant paper (pulp-based sheets treated with flame retardants such as guanidine sulfamate and guanidine phosphate); inorganic additives such as aluminum hydroxide and magnesium hydroxide Inorganic paper including; fine paper; thin paper and the like.

The basis weight of the paper quality substrate is not limited, but preferably about 50 to 300 g / ^{m 2,} about 50 to 80 g / ^{m 2} is more preferable.

Foamed resin layer The foamed resin layer is formed by foaming a foaming agent-containing resin layer.

  The foaming agent-containing resin layer includes a resin component, a foaming agent, other additives, and the like. Although it does not limit as a resin component, For example, ethylene copolymer resin is preferable. Among these, when the foaming agent-containing resin layer is formed by melt extrusion, melt extrusion is possible at a relatively low temperature, and foaming of the foaming agent in the machine (for example, abnormal foaming in the cylinder of the extruder) can be suppressed. From the viewpoint, EVA is preferable.

  As the foaming agent, a pyrolytic foaming agent is preferable. Examples of the thermally decomposable foaming agent include azo series such as azodicarbonamide (ADCA) and azobisformamide; and hydrazide series such as oxybenzenesulfonyl hydrazide (OBSH) and paratoluenesulfonyl hydrazide. The content of the pyrolytic foaming agent can be adjusted according to the type, the desired expansion ratio, and the like. Usually, about 1-20 weight part is preferable with respect to 100 weight part of resin of a foaming agent containing resin layer.

  Examples of other additives include inorganic fillers, pigments, cell regulators, and crosslinking aids.

  Examples of the inorganic filler include calcium carbonate, aluminum hydroxide, magnesium hydroxide, antimony trioxide, zinc borate, and a molybdenum compound.

  Examples of the pigment include the following. Examples of inorganic pigments include titanium oxide, zinc white, carbon black, black iron oxide, yellow iron oxide, yellow lead, molybdate orange, cadmium yellow, nickel titanium yellow, chrome titanium yellow, iron oxide (valve), and cadmium. Examples thereof include red, ultramarine blue, bitumen, cobalt blue, chromium oxide, cobalt green, aluminum powder, bronze powder, titanium mica, and zinc sulfide. Examples of organic pigments include aniline black, perylene black, azo (azo lake, insoluble azo, condensed azo), polycyclic (isoindolinone, isoindoline, quinophthalone, perinone, flavantron, anthrapyrimidine, anthraquinone, quinacridone, Perylene, diketopyrrolopyrrole, dibromoanthanthrone, dioxazine, thioindigo, phthalocyanine, indanthrone, halogenated phthalocyanine) and the like.

  Examples of the cell regulator include metal soaps and zinc compounds.

  Examples of the crosslinking aid include acrylic monomers. As addition amount of a crosslinking adjuvant, about 0-10 weight part is preferable with respect to 100 weight part of resin of a foaming agent containing resin layer, and 1-4 weight part is more preferable.

  Although the thickness of a foaming agent containing resin layer is not limited, About 10-200 micrometers is preferable.

  The foamed resin layer is formed by foaming the foaming agent-containing resin layer. Thermally decomposable foaming agents decompose and foam when heated. The heating condition is not limited as long as it is equal to or higher than the decomposition temperature of the pyrolytic foaming agent. The heating temperature is preferably about 200 to 300 ° C., and the heating time is preferably about 10 to 40 seconds. The expansion ratio of the foamed resin layer with respect to the foaming agent-containing resin layer is about 7 to 20 times.

  The foamed resin layer may be cross-linked with the non-foamed resin layer described later, or one of them. Examples of the resin crosslinking means include electron beam irradiation.

  The foamed resin layer may be directly laminated on the paper base, or may be laminated via an adhesive layer.

Non-foamed resin layer (surface protective layer)
The non-foamed resin layer contains a linear low density polyethylene resin and an ethylene-α olefin copolymer.

The linear low density polyethylene resin (LLDPE) usually has a density of about 0.910 to 0.938 g / cm ³ , among which about 0.915 to 0.925 g / cm ³ is preferable. Among such LLDPEs, focusing on the production method, mLLDPE produced using a metallocene catalyst is preferable.

  The non-foamed resin layer can be formed substantially from LLDPE and an ethylene-α olefin copolymer. The content of the ethylene-α-olefin copolymer as a modifier is not limited, but is preferably contained in the non-foamed resin layer by about 20 to 50% by weight, more preferably about 30 to 40% by weight. By including the ethylene-α olefin copolymer, curling of the wall covering decorative sheet is suppressed. In addition, when content exceeds 50 weight%, there exists a possibility that abrasion resistance may fall.

  The thickness of the non-foamed resin layer is not limited, but is preferably about 5 to 30 μm, and preferably about 10 to 15 μm.

A pattern layer may be formed on the front surface of the non-foamed resin layer.

  The pattern layer imparts design properties to the foamed wallpaper. Examples of the design pattern include a wood grain pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather pattern, a geometric figure, a character, a symbol, and an abstract pattern. The pattern can be selected according to the type of foam wallpaper.

  The pattern pattern layer is formed, for example, by printing a pattern pattern on the front surface of the non-foamed resin layer. Examples of printing methods include gravure printing, flexographic printing, silk screen printing, and offset printing. As the printing ink, a known printing ink containing a colorant, a vehicle, and a solvent can be used.

  The pigment can be used as the colorant.

  The vehicle can be set according to the type of the base sheet. For example, acrylic resin, styrene resin, polyester resin, urethane resin, chlorinated polyolefin resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl Examples include butyral resins, alkyd resins, petroleum resins, ketone resins, epoxy resins, melamine resins, fluorine resins, silicone resins, fiber derivatives, and rubber resins.

  Examples of the solvent (or dispersion medium) contained in the printing ink include petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ethyl acetate, butyl acetate, and 2-methoxyacetate. Ester-based organic solvents such as ethyl and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol; acetone, methyl ethyl ketone, methyl isobutyl ketone Ketone organic solvents such as cyclohexanone; ether organic solvents such as diethyl ether, dioxane and tetrahydrofuran; dichloromethane, carbon tetrachloride, trichloroethylene, Chlorinated organic solvents such as tiger chloroethylene; and water.

  The thickness of the pattern layer is different from the type of pattern, but is preferably about 0.1 to 10 μm.

The front surface of the embossed wall covering decorative sheet may be provided with an uneven pattern by embossing.

  The embossed pattern can be given by, for example, a known embossed plate. For example, a desired embossed pattern can be formed by pressing the embossed plate after heating and softening the front surface of the foamed resin layer. Embossed patterns include wood grain plate conduit grooves, stone plate surface irregularities, cloth surface textures, satin texture, sand texture, hair lines, and multi-line grooves.

Manufacturing method of wall covering decorative sheet The manufacturing method of the wall covering decorative sheet according to the present invention is not limited. It can manufacture suitably with a method. The melt coextrusion can be performed by a T-die extruder, for example.

  After melt extrusion, a pattern layer is formed on the surface of the non-foamed resin layer, and then the foaming agent-containing resin layer is changed to a foamed resin layer by heating. In addition, when performing resin crosslinking by electron beam irradiation, it is preferable to carry out prior to a foaming process.

  In the decorative sheet for wall covering of the present invention, the non-foamed resin layer contains a linear low density polyethylene resin and an ethylene-α-olefin copolymer as resin components, so that it has high scratch resistance and curling is suppressed. Has been. This is presumably because the linear low-density polyethylene resin effectively acts to develop the scratch resistance, and the ethylene-α-olefin copolymer acts as a modifier that contributes to curl suppression.

Examples 1-2 and Comparative Examples 1-4
A foaming agent-containing resin composition was prepared by mixing an ethylene-vinyl acetate copolymer resin, an inorganic filler, a pigment, a thermally decomposable foaming agent, a cell regulator and a crosslinking aid. The blending ratio of each component is shown in Table 1 below.

  A non-foamed resin composition was prepared by mixing mLLDPE and an ethylene-α-olefin copolymer. The blending ratio of each component is shown in Table 2 divided into Examples and Comparative Examples. The thickness of the non-foamed resin layer is also shown in Table 2.

  The composition was melt-extruded on a base paper (HPT-65 Hokuetsu Paper Manufacturing Co., Ltd.) using a T-die extruder to laminate a foaming agent-containing resin layer and a non-foamed resin layer. The thickness of the foamed resin layer was 90 μm.

  The resin sheet was irradiated with an electron beam (irradiation amount: 3 Mrad) to crosslink the resin. Next, after forming a pattern layer on the surface of the resin sheet, heating and foaming were performed by heating at 220 ° C. for 30 seconds. An uneven pattern was further provided on the resin sheet side by embossing.

  Through the above process, a wall covering decorative sheet was produced.

Test example 1
About the decorative sheet for wall covering produced in the Example and the comparative example, the presence or absence of curl and scratch resistance were evaluated.

  As for the presence or absence of curling, ◎ indicates that no curling is observed, ○ indicates that curling is hardly recognized, and × indicates that curling is clearly recognized.

  As for the scratch resistance, the scratch resistance was evaluated using a test method in the surface-enhanced product performance display prescribed by the Japan Vinyl Industry Association Vinyl Building Section Committee and the Wall Wholesaler Association. Evaluation is grade 5 when there is no change, grade 4 when there is a slight change in the surface, grade 3 when the surface is broken and the resin layer and foamed layer are visible, and surface is broken and the base material layer is visible (length) Less than 1 cm) was graded 2, and the surface was broken and the substrate layer was visible (length 1 cm or more) was graded 1.

  The evaluation results are shown in Table 3 below.

Claims (7)

A decorative sheet for wall covering in which at least a foamed resin layer and a non-foamed resin layer are sequentially formed on a paper substrate,
(1) The foamed resin layer is formed by foaming the foaming agent-containing resin layer,
(2) The decorative sheet for wall covering, wherein the non-foamed resin layer has a thickness of 10 to 15 μm and contains a linear low density polyethylene resin and an ethylene-α-olefin copolymer.   The decorative sheet for wall covering according to claim 1, wherein the ethylene-α-olefin copolymer is contained in an amount of 20 to 50% by weight in the non-foamed resin layer.   The decorative sheet for wall covering according to claim 1 or 2, wherein the foaming agent-containing resin layer contains an ethylene-vinyl acetate copolymer as a resin component.   The decorative sheet for wall covering according to any one of claims 1 to 3, wherein the foaming agent is a pyrolytic foaming agent.   The decorative sheet for wall covering according to any one of claims 1 to 4, wherein the foaming agent-containing resin layer comprises an ethylene-vinyl acetate copolymer, an inorganic filler, a pigment, a pyrolytic foaming agent, and a cell conditioner.   The decorative sheet for wall covering according to any one of claims 1 to 5, wherein at least one of the foamed resin layer and the non-foamed resin layer is resin-crosslinked by electron beam irradiation.   The decorative sheet for wall covering according to any one of claims 1 to 6, which has an uneven pattern formed by embossing.