Decorative floor material

Abstract

To provide a decorative floor material having scratch resistance capable of withstanding scratches caused by a heavy load and providing comfort when walking thereon.SOLUTION: A decorative floor material includes a wood base material, a cushion layer, and a decorative sheet laminated at least in this order, the decorative sheet having a backer layer on the side with the cushion layer, the cushion layer having a thickness of 0.5 mm or more and 5 mm or less, the decorative sheet having a thickness of 300 μm or more and 600 μm or less, and the backer layer having a thickness of 100 μm or more and 350 μm or less. In the rate of change in the measured value of durometer hardness measured in accordance with JIS K 7215:1986 by bringing an indenter of a durometer hardness tester into contact with the surface on the side with the decorative sheet (derived by the method of the following formula (1)) is 2% or more and 6% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to floor coverings. [Background technology]

[0002] BACKGROUND ART Conventionally, decorative floor materials having a decorative sheet laminated on the surface thereof have been used as floor materials applied to the floor surfaces of buildings.

[0003] As a decorative sheet to be used as a floor decorative material, a decorative sheet provided with a backer layer having a hard layer and a soft layer has been proposed in order to provide scratch resistance and comfort when walking on it.

[0004] For example, Patent Document 1 discloses a decorative sheet for flooring comprising a decorative sheet intermediate having one or more layers laminated on the front surface of a base sheet, and a synthetic resin backer layer on the back surface of the base sheet, wherein the synthetic resin backer layer is composed of two or more layers consisting of a hard layer and a soft layer, and at least the layer in contact with the base sheet is a hard layer.

[0005] Furthermore, decorative floor materials have been proposed that place emphasis on comfort, taking into account factors such as the warmth felt when walking, by replacing the soft layer with a foam.

[0006] For example, Patent Document 2 discloses a floor decorative material in which at least a foamed resin layer and a decorative sheet are laminated in this order on a wood substrate, characterized in that (1) the decorative sheet has a synthetic resin backing layer laminated as the bottom layer, (2) the synthetic resin backing layer has an upper yield point load or maximum point load of 90 N or more as determined from a load-elongation curve obtained by a tensile test in accordance with JIS K7127, and a thickness of less than 0.5 mm, and (3) the foamed resin layer has a 0.2% yield strength of 2 N or more as determined from a load-elongation curve obtained by a tensile test in accordance with JIS K7127, and the elongation of the foamed resin layer at the point showing the 0.2% yield strength on the load-elongation curve is 5% or more, and the expansion ratio is 2 to 20 times. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-106654 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-189979 Summary of the Invention [Problem to be solved by the invention]

[0008] In recent years, there has been a demand for decorative floor materials that are scratch-resistant enough to withstand heavy scratching and are comfortable to walk on.

[0009] Conventional floor decorative materials have room for further improvement in terms of the above-mentioned problems. [Means for solving the problem]

[0010] After extensive research, the inventors discovered that all of the above problems can be solved by setting the thicknesses of the cushion layer (soft layer), decorative sheet, and backer layer (hard layer) provided on the decorative sheet that make up the floor decorative material within a specific range, and by controlling the rate of change in the measured durometer hardness of the surface provided with the decorative sheet within a specific range, and thus completed the present invention.

[0011] The present invention provides a decorative floor material comprising a wood base material, a cushion layer, and a decorative sheet laminated at least in this order, the decorative sheet having a backer layer on the side with the cushion layer, the cushion layer having a thickness of 0.5 mm or more and 5 mm or less, the decorative sheet having a thickness of 300 μm or more and 600 μm or less, and the backer layer having a thickness of 100 μm or more and 350 μm or less, wherein the rate of change in the measured durometer hardness (derived by the method of the following formula (1)) measured in accordance with JIS K 7215:1986 by contacting the indenter of a durometer hardness tester with the surface with the decorative sheet is 2% or more and 6% or less.

number

[0012] In the floor decorative material of the present invention, the cushion layer preferably has a thickness of 0.8 mm or more and 3.5 mm or less. The cushion layer preferably contains a flame retardant. The thickness of the decorative sheet is preferably 300 μm or more and 580 μm or less. The decorative sheet preferably has a surface protective layer on the side opposite to the backer layer. The surface protection layer preferably comprises two or more ionizing radiation curable resin layers, and has a total thickness of 10 μm or more and 50 μm or less. Furthermore, the thickness of each of the two or more ionizing radiation curable resin layers is preferably 5 μm or more and 25 μm or less. Of the two or more ionizing radiation curable resin layers, the ionizing radiation curable resin layer located on the farthest side from the side where the backer layer is provided preferably has the highest hardness. Furthermore, it is preferable that the decorative sheet has a transparent resin layer between the backer layer and the surface protective layer, and that the transparent resin layer contains a phosphorus-based flame retardant in an amount of 5% by mass or more and 15% by mass or less relative to the mass of the transparent resin layer. It is also preferable that the wood substrate further includes a cork layer on the side opposite to the cushion layer. It is also preferable that the surface on the side where the decorative sheet is provided has an uneven shape. [Effects of the Invention]

[0013] The present invention can provide a decorative floor material that has scratch resistance that can withstand scratches caused by heavy loads and is comfortable to walk on. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view in the thickness direction showing an example of the floor decorative material of the present invention. [Figure 2] FIG. 2 is a cross-sectional view in the thickness direction showing a preferred example of the decorative sheet that constitutes the floor decorative material of the present invention. [Figure 3] FIG. 3 is a diagram illustrating a method for measuring the hardness of an ionizing radiation curable resin layer. [Figure 4] FIG. 4 is a diagram illustrating the combustion test. DETAILED DESCRIPTION OF THE INVENTION

[0015] <Floor decorative material> The decorative floor material of the present invention comprises a wood base material, a cushion layer, and a decorative sheet laminated at least in this order, the decorative sheet having a backer layer on the side with the cushion layer, the cushion layer having a thickness of 0.5 mm or more and 5 mm or less, the decorative sheet having a thickness of 300 μm or more and 600 μm or less, and the backer layer having a thickness of 100 μm or more and 350 μm or less, and the rate of change in the measured durometer hardness (derived by the method of the following formula (1)) measured in accordance with JIS K 7215:1986 by contacting the indenter of a durometer hardness tester with the surface with the decorative sheet is 2% or more and 6% or less.

number

[0016] FIG. 1 is a cross-sectional view in the thickness direction showing an example of the floor decorative material of the present invention. As shown in FIG. 1, the floor decorative material 1 comprises a wood substrate 2, a cushion layer 3, and a decorative sheet 4 laminated in this order. Furthermore, a cork layer 5 is provided on the side of the wood base material 2 opposite to the cushion layer 3.

[0017] (Percentage change in durometer hardness measurements) The decorative floor material of the present invention has a change rate of 2% or more and 6% or less in the measured durometer hardness measured in accordance with JIS K 7215:1986 by contacting the indenter of a durometer hardness tester with the surface on which the decorative sheet is provided. When the rate of change in the measured value of durometer hardness is within the above range, the decorative floor material can be provided with scratch resistance and comfort when walking on it.

[0018] The rate of change in durometer hardness measured in accordance with JIS K 7215:1986 (also simply referred to as the rate of change in durometer hardness measurement) is preferably 2.5% or more, and more preferably 5% or less, and more preferably 4.5% or less.

[0019] The rate of change in the measured value of durometer hardness is measured in accordance with JIS K7215:1986 using a durometer hardness tester type A (manufactured by Teclock Corporation). The indenter of the hardness tester is placed against the outermost surface of the floor decorative material (the surface with the decorative sheet), and the value immediately after (0 s) and the value after 15 seconds (15 s) are read. This measurement is carried out at five random points on the floor decorative material, and the average value of the value immediately after (0 s) and the value after 15 seconds (15 s) is calculated. The rate of change is calculated using the following formula:

number

[0020] Each component of the floor decorative material will be described below.

[0021] <Wood base material> The floor decorative material of the present invention comprises a wood substrate.

[0022] Examples of the wood substrate include medium density fiberboard (MDF), high density fiberboard (HDF), and particleboard (PB), as well as wood plywood made from lauan, conifers, and plantation trees. Among these, medium density wood fiberboard (MDF) and high density wood fiberboard (HDF) are preferred from the viewpoint of excellent surface quality (smoothness) and scratch resistance.

[0023] The thickness of the wood substrate is not particularly limited, but is preferably, for example, 2 mm or more and 15 mm or less.

[0024] <Cushion layer> The floor decorative material of the present invention includes a cushion layer.

[0025] The resin forming the cushion layer is preferably a thermoplastic resin, such as polypropylene (PP), polyethylene, ethylene-propylene copolymer, ethylene-methacrylic acid copolymer (EMMA), ethylene-vinyl acetate copolymer (EVA), polyurethane, polyvinyl chloride, etc.

[0026] The cushioning layer may be foamed. In this case, examples of resins that form the cushion layer include polypropylene (PP), polyethylene (PE), ethylene-propylene copolymer, acrylic, ethylene-methacrylic acid copolymer (EMMA), ethylene-vinyl acetate copolymer (EVA), polyurethane, polyvinyl chloride, polymethylene, polymethylpentene, polyethylene terephthalate (PET), polybutylene terephthalate, polycarbonate, polyarylate, polyimide, polystyrene, polyamide, and ABS.

[0027] Examples of foaming agents contained in the resin that forms the cushion layer include inorganic foaming agents such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, and ammonium nitrite; nitroso compounds such as N,N'-dimethyl-N,N'-dinitrosoterephthalamide and N,N'-dinitrosopentamethylenetetramine; azo compounds such as azodicarbonamide, azobisformamide, azobisisobutyronitrile, azocyclohexylnitrile, azodiaminobenzene, and barium azodicarboxylate; sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, p,p'-oxybis(benzenesulfonyl hydrazide), and diphenylsulfone-3,3'-disulfonyl hydrazide; and azide compounds such as calcium azide, 4,4'-diphenyldisulfonyl azide, and p-toluenesulfonyl azide. Among these, the thermal decomposition type foaming agent is preferred.

[0028] The content of the foaming agent can be appropriately set depending on the type of foaming agent, the expansion ratio, and the like.

[0029] When the thermally decomposable foaming agent is used, foaming can be achieved by heating. The heating conditions are not limited as long as they allow the formation of a foamed cushion layer by decomposition of the thermally decomposable foaming agent.

[0030] The cushion layer may contain additives such as wood flour and inorganic substances, if necessary. Examples of the inorganic substances include silica, ilmenite, kaolin, bentonite, mica, talc, calcium carbonate, and aluminum hydroxide.

[0031] The cushion layer may contain a flame retardant, if necessary. Examples of the flame retardant include metal hydroxides such as aluminum hydroxide and magnesium hydroxide, antimony trioxide, inorganic ammonium phosphate, dehydrated minerals, and expandable graphite. The flame retardant contained in the cushion layer may be used alone or in combination of two or more.

[0032] The amount of the flame retardant contained in the cushion layer is preferably 5% by mass or more and 20% by mass or less, and more preferably 8% by mass or more and 15% by mass or less, relative to the mass of the cushion layer.

[0033] The cushion layer has a thickness of 0.5 mm or more and 5 mm or less. By ensuring that the thickness of the cushion layer is within the above range, the rate of change in the measured durometer hardness value can be controlled within a specific range, thereby imparting scratch resistance and comfort when walking on the floor decorative material. The thickness of the cushion layer is preferably 0.8 mm or more, more preferably 1 mm or more, and is preferably 3.5 mm or less, more preferably 3 mm or less.

[0034] <Decorative sheet> The decorative floor material of the present invention comprises a decorative sheet.

[0035] FIG. 2 is a cross-sectional view in the thickness direction showing a preferred example of the decorative sheet that constitutes the floor decorative material of the present invention. As shown in FIG. 2, the decorative sheet 4 has a backer layer 11, a substrate sheet 12, a design layer 13, a transparent resin layer 14, and a surface protection layer 15 laminated in this order. The surface protection layer 15 has two ionizing radiation curable resin layers 16 and 17 . Each component of the decorative sheet will be described below.

[0036] (Backer layer) The decorative sheet has a backer layer on the side having the cushion layer. By providing the decorative sheet with a backer layer, it is possible to impart scratch resistance that can withstand high-load scratches and impact resistance.

[0037] The backer layer can be produced by molding the resin composition into a sheet (film) by a calendering method, an inflation method, a T-die extrusion method, or the like. Co-extrusion film formation can easily form two or more resin layers, and for extrusion film formation, a multi-manifold type or feed block type T-die can be used, for example.

[0038] The resin forming the backer layer is preferably a thermoplastic resin, such as polypropylene (PP), polyethylene (PE), ethylene-propylene copolymer, acrylic, polyurethane, polyvinyl chloride, polymethylene, polymethylpentene, polyethylene terephthalate (PET), polybutylene terephthalate, polycarbonate, polyarylate, polyethylene naphthalate-isophthalate copolymer, polyimide, polystyrene, polyamide, ABS, etc. Of these, polypropylene is preferred.

[0039] The backing layer may contain additives such as wood flour and inorganic substances, if necessary. Examples of the inorganic substances include silica, ilmenite, kaolin, bentonite, mica, talc, calcium carbonate, and aluminum hydroxide.

[0040] The thickness of the backer layer is 100 μm or more and 350 μm or less. From the viewpoint of providing suitable impact resistance, the thickness of the backer layer is preferably 120 μm or more, more preferably 150 μm or more, and even more preferably 200 μm or more.

[0041] (Base sheet) The decorative sheet preferably has a substrate sheet.

[0042] Examples of the base sheet include polyester-based resins such as polyethylene terephthalate (PET); polyolefin-based resins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer resin, ethylene-propylene-butene copolymer resin, and olefin-based thermoplastic elastomer; polyurethane-based resins such as acrylic-modified urethane-based resin, polyester-modified urethane-based resin, and vinyl chloride-vinyl acetate copolymer-modified urethane-based resin; acrylic resins; polycarbonate-based resins; polystyrene-based resins; vinyl chloride-based resins, vinyl acetate-based resins, and vinyl chloride-vinyl acetate copolymer resins.

[0043] The thickness of the substrate sheet is preferably, for example, 30 μm or more and 300 μm or less.

[0044] (Picture layer) The decorative sheet preferably includes a pattern layer.

[0045] The pattern layer can be formed with any desired pattern, such as wood grain, stone grain, sand grain, tiled pattern, brickwork pattern, fabric pattern, leather-striped pattern, geometric figures, letters, symbols, and abstract patterns.

[0046] The design layer can be formed by printing with a printing ink containing a known pigment or dye as a colorant, using a resin such as a polyvinyl resin, a polyester resin, an acrylic resin, a polyvinyl acetal resin, or a cellulose resin as a binder.

[0047] Methods for forming the design layer include known printing methods such as gravure printing, offset printing, silk screen printing, transfer printing from a transfer sheet, sublimation transfer printing, and ink jet printing.

[0048] The thickness of the design layer is preferably, for example, 0.1 μm or more and 10 μm or less.

[0049] (Transparent resin layer) The decorative sheet preferably includes a transparent resin layer.

[0050] Examples of the transparent resin layer include polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ionomer, polymethylpentene, acrylic acid ester, methacrylic acid ester, polycarbonate, and cellulose triacetate.

[0051] The transparent resin layer may contain a flame retardant, if necessary.

[0052] Examples of the flame retardant contained in the transparent resin layer include expanded graphite, hydrated metal flame retardants, inorganic phosphate flame retardants, and metal phosphinate flame retardants, and phosphorus-based flame retardants such as inorganic phosphate flame retardants and metal phosphinate flame retardants are preferred. The flame retardant contained in the transparent resin layer may be used alone or in combination of two or more.

[0053] The inorganic phosphate is not particularly limited, and examples thereof include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium amide polyphosphate, and aluminum polyphosphate.

[0054] The metal phosphinate is not particularly limited, and examples thereof include calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum phosphinate, aluminum dimethylphosphinate, zinc phosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, methylenebis(methylphosphinate) phenylene-1,4-bis(methylphosphinate), calcium phenylene-1,4-bis(methylphosphinate), magnesium phenylene-1,4-bis(methylphosphinate), aluminum phenylene-1,4-bis(methylphosphinate), zinc phenylene-1,4-bis(methylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, and zinc diphenylphosphinate.

[0055] The content of the flame retardant contained in the transparent resin layer is preferably 5% by mass or more, and more preferably 6% by mass or more, relative to the mass of the transparent resin layer. Furthermore, the content of the flame retardant contained in the transparent resin layer is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 10% by mass or less, relative to the mass of the transparent resin layer. By setting the lower limit of the content of the flame retardant contained in the transparent resin layer within the above range, the flame retardancy and fire spread resistance of the floor decorative material can be further improved. Also, by setting the upper limit of the content of the flame retardant contained in the transparent resin layer within the above range, the occurrence of whitening scratches in the floor decorative material can be further suppressed.

[0056] The thickness of the transparent resin layer is preferably, for example, 10 μm or more and 300 μm or less.

[0057] (Surface protective layer) The decorative sheet preferably has a surface protective layer on the side opposite to the side on which the backer layer is provided.

[0058] The surface protective layer is preferably a layer obtained by curing an ionizing radiation curable resin (also referred to as an ionizing radiation curable resin layer).

[0059] The ionizing radiation curable resin is a resin that is cured by irradiation with ionizing radiation, i.e., electromagnetic waves or charged particle beams that have an energy quantum capable of polymerizing or crosslinking molecules, such as ultraviolet (UV) rays or electron beams (EB), as well as electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as α-rays and ion beams. Specifically, the ionizing radiation curable resin can be appropriately selected from commonly used polymerizable monomers and polymerizable oligomers.

[0060] As the polymerizable monomer, for example, a (meth)acrylate monomer having a radically polymerizable unsaturated group in the molecule is suitable, and among these, a polyfunctional (meth)acrylate monomer is preferred. The polyfunctional (meth)acrylate monomer may be a (meth)acrylate monomer having two or more ethylenically unsaturated bonds in the molecule, and preferred examples include diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. These (meth)acrylate monomers can be used alone or in combination of two or more. In this specification, (meth)acrylate means acrylate or methacrylate.

[0061] Preferred examples of the polymerizable oligomer include oligomers having a radically polymerizable unsaturated group in the molecule, such as (meth)acrylate oligomers such as urethane (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, polyester (meth)acrylate oligomers, polyether (meth)acrylate oligomers, and acrylic (meth)acrylate oligomers. These polymerizable oligomers can be used alone or in combination of two or more.

[0062] The surface protective layer preferably comprises two or more ionizing radiation curable resin layers.

[0063] Of the two or more ionizing radiation curable resin layers, it is preferable that the ionizing radiation curable resin layer located on the farthest side from the side where the backer layer is provided has the highest hardness.

[0064] When the ionizing radiation curable resin layer has three or more layers, it is preferable that the hardness of the ionizing radiation curable resin layer increases in order from the layer located most opposite to the side where the backer layer is provided. The hardness of the ionizing radiation curable resin layer can be adjusted by appropriately selecting the ionizing radiation curable resin that forms the ionizing radiation curable resin layer.

[0065] The hardness of the ionizing radiation curable resin layer refers to nanoindentation hardness measured using a surface film physical property tester, Triboindenter (registered trademark) "TI-950" (manufactured by HYSITRON Corporation).

[0066] The indentation hardness (HIT) of the ionizing radiation curable resin layer was measured using a Tribo Indenter (registered trademark) "TI-950" as follows. (1) Using the Berkovich indenter shown in Figure 3(a), the Berkovich indenter 21 is pressed into the measurement sample 20 as shown in Figure 3(b) under the indentation conditions described below in the direction of the arrow indicating the load direction 22, and the "contact projected area (Ap) (mm ) corrected by the standard method of the instrument" is calculated from the triangular pyramid-shaped geometric shape formed on the surface. 2 The hardness is calculated by dividing the maximum test load (Fmax) by the Ap, i.e., HIT=Fmax / Ap. (2) Here, the indentation conditions were as follows: at room temperature (laboratory ambient temperature), as shown in Figure 3(c), for the ionizing radiation-curable resin layer on the outermost surface side (the side farthest from the side with the backer layer), a load of 0 to 100 μN was first applied over 10 seconds (i.e., 10 μN / s), then a load of 100 μN (Fmax) was held for 5 seconds, and finally, the load was reduced to 100 μN and released over 10 seconds. For the ionizing radiation-curable resin layer on the transparent resin layer side, a load of 0 to 50 μN was first applied over 5 seconds (i.e., 10 μN / s), then a load of 50 μN (Fmax) was held for 5 seconds, and finally, the load was reduced to 50 μN and released over 10 seconds. Typically, the indentation amount (h) is about 100 to 150 nm, so the thickness of the layer to be measured in the indentation direction should be 1.0 μm or more (preferably 1.5 μm or more). Ap is 24.50 [hmax-ε(hmax-hr)] 2(where ε is a correction factor due to the geometric shape of the indenter, and hr is the depth of the triangular pyramidal geometric shape remaining on the surface after unloading.) (3) When measuring hardness, the hardness of the cross section of the layer to be measured is measured to avoid the influence of the hardness of layers other than the layer that will be the measurement sample 20. That is, the decorative sheet is embedded in resin (a cold-setting type two-component epoxy resin) and left to harden at room temperature for 24 hours or more, and then the hardened embedded sample is mechanically polished to expose the cross section of the layer to be measured, and the hardness of the cross section of each layer is measured by pressing a Berkovich indenter 21 into the cross section of the layer to be measured (a position that avoids the fine particles if the layer contains fine particles such as filler). (4) The indentation hardness is measured at 10 locations to avoid bias, and the average values ​​of the 10 locations are used as the “hardness of the ionizing radiation curable resin layer on the outermost surface side” and the “hardness of the ionizing radiation curable resin layer on the side having the transparent resin layer.”

[0067] From the viewpoint of scratch resistance (suppressing scratches formed on the surface of the decorative sheet), the thickness of each of the two or more ionizing radiation curable resin layers is preferably 5 μm or more and 25 μm or less. The surface protection layer preferably has a total thickness of 10 μm or more and 50 μm or less.

[0068] (others) The decorative sheet may be provided with a primer layer or a transparent adhesive layer between the above-mentioned layers as appropriate.

[0069] The primer layer is not particularly limited, and a layer formed from a known primer agent can be used. Examples of the primer agent include a urethane resin-based primer agent made of an acrylic-modified urethane resin (acrylic urethane-based resin), a primer agent made of a urethane-cellulose-based resin (for example, a resin obtained by adding hexamethylene diisocyanate to a mixture of urethane and soluble nitrocellulose), and a resin-based primer agent made of an acrylic-urethane block copolymer.

[0070] The thickness of the primer layer is not particularly limited, but is preferably, for example, 0.5 μm or more and 10 μm or less.

[0071] The transparent adhesive layer is not particularly limited, and any known adhesive may be used. Examples include polyurethanes, acrylics, polyolefins, polyvinyl acetates, polyvinyl chlorides, vinyl chloride-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ionomers, as well as butadiene-acrylonitrile rubber, neoprene rubber, and natural rubber. These adhesives may be used alone or in combination of two or more.

[0072] The thickness of the transparent adhesive layer is not particularly limited, but is preferably, for example, from 0.5 μm to 30 μm.

[0073] Each layer constituting the decorative sheet may contain additives as required. Examples of the additives include lubricants such as silicone resins, waxes, and fluororesins, colorants such as dyes and pigments, antioxidants, ultraviolet absorbers, light stabilizers, radical scavengers, flame retardants, deodorizers, antibacterial agents, antiviral agents, antiallergens, and antifungal agents. The amount of additives to be added can be appropriately determined depending on the product characteristics.

[0074] (Uneven shape) The decorative floor material of the present invention preferably has an uneven shape on the surface on which the decorative sheet is provided. By providing an uneven shape on the surface on which the decorative sheet is provided, it is possible to provide a suitable design.

[0075] The uneven shape may have a center line average roughness Ra specified in JIS B 0601 (1982) in the range of 1 μm or more and 30 μm or less, and a maximum height Rz specified in JIS B 0601 (2001) in the range of 20 μm or more and 200 μm or less.

[0076] The method for forming the uneven shape is not particularly limited, and examples thereof include a method of embossing with heat and a method of transferring the uneven shape using a shaping sheet. Examples of heat embossing include embossing using a well-known sheet-type or rotary embosser. Examples of embossed patterns include sand grain, hairline, matte finish, wood grain vessel grooves, uneven stone surface, cloth surface texture, and linear grooves.

[0077] (Thickness of decorative sheet) The thickness of the decorative sheet is 300 μm or more and 600 μm or less. By ensuring that the thickness of the decorative sheet is within the above range, it is possible to impart scratch resistance that can withstand scratches under heavy loads and impact resistance. The thickness of the decorative sheet is preferably 320 μm or more and 580 μm or less. When the decorative sheet has the irregularities, the thickness of the decorative sheet is measured from the outermost layer where the irregularities are not formed to the surface opposite the surface protective layer. When an uneven shape is formed on each layer constituting the decorative sheet, the thickness is measured in the same manner (from the surface of the portion of each layer where an uneven shape is not formed to the surface opposite the surface protective layer side).

[0078] <Cork layer> The floor decorative material of the present invention preferably further comprises a cork layer on the side of the wood substrate opposite to the side on which the cushion layer is provided. By providing the cork layer, the floor decorative material can be suitably provided with comfort when walking on it.

[0079] The cork layer can be made of so-called natural cork, which is a highly elastic material made by peeling and processing the cork tissue from the bark of cork oak, or so-called synthetic cork, which is made to resemble cork. Moreover, various commercially available products (cork sheets) may be used as the cork layer.

[0080] The density of the cork layer is, for example, 0.1 g / cm 3 More than 0.5g / cm 3 The following is preferred:

[0081] The thickness of the cork layer is preferably 1 mm or more and 3 mm or less.

[0082] <Other> The floor decorative material of the present invention may have an adhesive layer between each layer. As the adhesive layer, those exemplified for the decorative sheet can be used.

[0083] <Manufacturing method> The method for producing the floor decorative material of the present invention is not particularly limited, and may be a method in which the above-mentioned layers are laminated together via the above-mentioned adhesive.

[0084] The present specification discloses the following:

[0085] The present disclosure (1) is a decorative floor material comprising a wood base material, a cushion layer, and a decorative sheet laminated at least in this order, the decorative sheet having a backer layer on the side with the cushion layer, the cushion layer having a thickness of 0.5 mm or more and 5 mm or less, the decorative sheet having a thickness of 300 μm or more and 600 μm or less, and the backer layer having a thickness of 100 μm or more and 350 μm or less, wherein the indenter of a durometer hardness tester is abutted against the surface with the decorative sheet, and the change rate of the measured durometer hardness (derived by the method of the following formula (1)) measured in accordance with JIS K 7215:1986 is 2% or more and 6% or less.

number

[0086] The present invention will now be described in more detail with reference to examples, but is not limited to these examples.

[0087] The following materials were prepared for use in the examples and comparative examples.

[0088] Example 1 <Making decorative sheets> A substrate sheet made of a 60 μm thick colored polypropylene film was prepared, and a 2 μm thick pattern layer was printed on one side of the substrate. Furthermore, a 3 μm thick transparent adhesive layer was formed on the pattern layer using a two-component curing urethane-based dry laminating adhesive (mixed with polyester polyol 1,6-hexamethylene diisocyanate (HMDI)). Next, a transparent resin layer (10 μm of maleic acid-modified PP on the transparent adhesive layer side and 130 μm of random PP on the ionizing radiation cured resin layer side, for a total thickness of 140 μm) was laminated on top of the transparent adhesive layer using extrusion lamination. The transparent resin layer was subjected to a corona discharge treatment, and then a primer layer (3 μm thick) was formed on the treated surface by gravure coating with an acrylic urethane resin (a two-component curable polyurethane resin containing an acrylic polyol and a urethane polyol as base agents and 1,6-hexamethylene diisocyanate (HMDI) as a curing agent) to improve the adhesion of the surface protective layer. A urethane acrylate electron beam-curable resin A was gravure coated onto the primer layer as the first ionizing radiation-curable resin layer, and after drying, a urethane acrylate electron beam-curable resin B was similarly coated as the second ionizing radiation-curable resin layer. The uncured electron beam-curable resin layer was cured by irradiating it with an electron beam (accelerating voltage 175 keV, exposure dose 5 Mrad) in an environment with an oxygen concentration of 200 ppm or less. After curing, the first ionizing radiation-curable resin layer was 10 μm thick, and the second ionizing radiation-curable resin layer was 10 μm thick. Next, the outermost ionizing radiation cured resin layer (second layer) was embossed with a wood grain vessel-shaped embossing plate with a plate depth of 80 μm to form a wood grain vessel-shaped uneven pattern. A 120 μm-thick olefin film was then attached to the back surface of the substrate sheet (the side opposite to the side with the design layer) to form a backer layer. The backer layer was subjected to a corona discharge treatment, and a 2 μm-thick primer layer was formed on the treated surface to produce a decorative sheet.

[0089] <Production of floor decorative materials> The decorative sheet and a 1mm-thick polyethylene foam cushion were bonded together using a two-component curing urethane-based dry laminating adhesive (a mixture of polyester polyol 1,6-hexamethylene diisocyanate (HMDI)). The cushions used had been corona discharge treated on both sides. The bonded cushion-decorative sheet composite was then bonded to a wood substrate (particle board) via an adhesive layer formed by applying 7g / square shaku of emulsion-type two-component urethane adhesive BA-10L / BA-11B (manufactured by Chuo Rika Kogyo Co., Ltd.) to the wood substrate, producing a decorative flooring material.

[0090] Examples 2 to 4 In producing the decorative sheet, the transparent resin layer was adjusted to 100 μm (10 μm of maleic acid-modified PP on the transparent adhesive layer side, and 90 μm of random PP on the ionizing radiation cured resin layer side, for a total thickness of 100 μm), and the backer layer and cushion layer were each adjusted to the thicknesses listed in Table 1. Other production methods were the same as in Example 1.

[0091] Examples 5 to 7 In producing the decorative sheet, ammonium polyphosphate was blended into the transparent resin layer in the amounts shown in Table 3, and the thickness of the transparent resin layer was adjusted to the values ​​shown in Table 3. Also, for the cushion layer, aluminum hydroxide and magnesium hydroxide were added so that the total content thereof would be the value shown in Table 3, and the thickness of the cushion layer was adjusted. The backer layers were adjusted to have the thicknesses shown in Table 3. Other manufacturing methods were the same as in Example 1.

[0092] Example 8 In producing the decorative sheet, the transparent resin layer was blended with expanded graphite to the content shown in Table 3, and the thickness was adjusted to the value shown in Table 3. The cushion layer was also used after adjusting the thickness by adding aluminum hydroxide and magnesium hydroxide so that the total content thereof was the value shown in Table 3. The backer layer was also adjusted to have the thickness shown in Table 3. The other production methods were the same as in Example 1.

[0093] (Comparative Examples 1 to 12) In producing the decorative sheet, a transparent resin layer of the thickness shown in Tables 1 and 2 was prepared (10 μm of maleic acid-modified PP on the transparent adhesive layer side, and the thickness of the random PP on the ionizing radiation-cured resin layer side was adjusted so that the total thickness was as shown in Tables 1 and 2). In addition, only the first layer (thickness 10 μm) of an ionizing radiation curable resin layer was coated. Furthermore, the backer layer and the cushion layer were adjusted to have the thicknesses shown in Table 1. Other manufacturing methods were the same as in Example 1. However, Comparative Example 1 was produced without forming a cushion layer, and Comparative Example 2 was produced without forming a backer layer.

[0094] (Comparative Example 13) In producing the decorative sheet, a transparent resin layer, a backer layer, and a cushion layer were prepared with thicknesses shown in Table 3. In addition, only the first layer was coated with an ionizing radiation curable resin layer. The other production methods were the same as in Example 1.

[0095] (Comparative Example 14) In producing the decorative sheet, a transparent resin layer, a backer layer, and a cushion layer were prepared with the thicknesses shown in Table 3. In addition, only the first layer was coated with an ionizing radiation curable resin layer. The flame retardants shown in Table 3 were added to the transparent resin layer and the cushion layer in the amounts shown. The other production methods were the same as in Example 1.

[0096] <Rate of change in durometer hardness measurement> The rate of change in the measured value of durometer hardness was measured in accordance with JIS K7215:1986 using a durometer hardness tester type A (manufactured by Teclock Corporation). The indenter of the hardness meter was placed on the outermost surface of the prepared floor decorative material (the surface with the decorative sheet), and the value immediately after (0 s) and the value after 15 seconds (15 s) were read. This measurement was performed at five arbitrary points on the floor decorative material, and the average value of the value immediately after (0 s) and the value after 15 seconds (15 s) was calculated. The rate of change in the measured value of durometer hardness was calculated using the following formula: The results are shown in Tables 1 and 2.

number

[0097] <Walking sensation evaluation> The floor decorative materials were evaluated by 25 people based on the sensations they felt when actually walking on them, according to the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria) ++: Over 80% of people answered that it was easy to walk on. +: Between 50% and 80% of people answered that it was easy to walk. -: Less than 50% of people answered that it was easy to walk

[0098] <Scratch resistance evaluation> Scratch resistance was evaluated using a Hamberger testing machine (manufactured by Hamberger Flooring GmbH & Co.KG, cutting jig tip material: tungsten), assuming the situation where furniture or the like is dragged. The test was performed by setting the load at 42 N, fixing the prepared floor decorative material on the test table with double-sided tape so that the decorative sheet side was the test surface, and then sliding the tester toward the front while pushing it in. The test surfaces were checked visually or by touch with the fingers for gouges and for Examples 5 to 8 and Comparative Examples 13 and 14 for whitening scratches, and were evaluated according to the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria for gouges) +: There are no cuts in the decorative sheet and the pattern can be seen -: The decorative sheet is torn, exposing the cushion layer or wood base material. (Evaluation criteria for whitening scratches) ++: Traces of the cutting tool of the testing machine on the decorative sheet are visible when viewed in oblique light. +: A state in which faint white marks from the cutting tool of the testing machine are visible intermittently on the decorative sheet. -: A state in which the cutting tool of the testing machine passes through a decorative sheet and leaves a clear white line.

[0099] <Impact resistance evaluation> Impact resistance was evaluated using a DuPont impact tester (manufactured by Toyo Seiki, weight of dropped object: 500g, radius of impact point: 6.3mm), assuming a situation where a mobile phone or TV remote control was dropped on the floor. The test was conducted in the following manner, with reference to JIS K 5600-5-3:1999. The drop height of the test weight was set to 50 cm, and the prepared floor decorative material was firmly fixed on the test table with the decorative sheet side facing the test surface. The weight was then allowed to fall freely from the specified height to apply an impact. The test was carried out at five points per sample (floor decorative material) (when test points were adjacent, they were spaced at least 1.5 cm apart). The test surface of the prepared floor decorative material was observed visually or with oblique light (oblique light when a light source was shone at an angle close to parallel to the test surface), and the presence or absence of cracks was confirmed and evaluated according to the following criteria. The results are shown in Tables 1 and 2. (Evaluation criteria) ++: 1 or less cracks out of 5 +: Number of cracks is 2 to 3 out of 5 -: 4 or more cracks out of 5

[0100] <Combustion test> The prepared floor decorative material was cut into a size of 9 cm x 20 cm to prepare a test piece. As shown in Figure 4, a rectangular metal stand 33 was placed on the stand 32 of a commercially available household heater 31 (Zaiguru Handsome SJ-100 (product name)), and a test piece 35 was placed in a metal frame 34 installed on the stand, and a fire spread resistance test was conducted under the conditions of a heater angle of 45° and a heater output dial of 4. Specifically, the test specimen was preheated for 2 minutes using the household heater. Then, as shown in Figure 4, the end 36 of the test specimen on the heater side in the longitudinal direction was heated with a lighter 37 for 1 minute to ignite the end, causing the fire to spread in the longitudinal direction of the test specimen. The state of the fire spread was then visually observed, and the extent of the fire was evaluated as follows: (Evaluation criteria) A: Does not ignite B: Combustion range is within 40% C: Combustion range is over 40% to 75% D: Combustion range is over 75% to 92% E: Completely burned (over 92%)

[0101] [Table 1]

[0102] [Table 2]

[0103] [Table 3]

[0104] It was confirmed that the floor decorative materials in the examples have scratch resistance that can withstand scratches caused by heavy loads, are comfortable to walk on, and also have excellent impact resistance. Furthermore, in the floor decorative materials of Examples 5 to 8, by including a specific amount of flame retardant in the transparent resin layer and cushion layer, it was confirmed that in addition to scratch resistance that can withstand heavy scratches, comfort when walking, and impact resistance, whitening scratches can be suppressed and the material also has excellent flame retardancy. [Explanation of symbols]

[0105] 1. Floor decorative materials 2 Wood base material 3 Cushion layer 4 decorative sheets 5 Cork Layer 11 Backer Tier 12 Base material 13 Picture layer 14 Transparent resin layer 15 Surface protective layer 16, 17 Ionizing radiation-curable resin layer 20 Measurement sample 21 Berkovich indenter 22 Load direction 31 Household heater 32 Household heater stand 33 Metal rectangular stand 34 Metal Frame 35 test specimens 36 End of the test piece on the heater side in the longitudinal direction 37 Writer

Claims

1. A wood base material, a cushion layer, and a decorative sheet are laminated at least in this order, the decorative sheet has a backer layer on the side having the cushion layer, The thickness of the cushion layer is 0.5 mm or more and 5 mm or less, The thickness of the decorative sheet is 300 μm or more and 600 μm or less, The thickness of the backer layer is 100 μm or more and 350 μm or less, A decorative floor material in which the rate of change in the measured value of durometer hardness measured in accordance with JIS K 7215:1986 by contacting the indenter of a durometer hardness tester with the surface on which the decorative sheet is provided is 2% or more and 6% or less (derived by the method of the following formula (1)). [Equation 1] (In the formula (1), 0s is the hardness (0s value) measured in accordance with JIS K7215:1986, with the indenter of a durometer hardness tester abutting against the surface on the side comprising the decorative sheet, and 15s is the hardness (15s value) measured in accordance with JIS K7215:1986, with the indenter of a durometer hardness tester abutting against the surface on the side comprising the decorative sheet, 15 seconds later.)

2. 2. The floor decorative material according to claim 1, wherein the cushion layer has a thickness of 0.8 mm or more and 3.5 mm or less.

3. The floor decorative material according to claim 1 or 2, wherein the cushion layer contains a flame retardant.

4. 3. The floor decorative material according to claim 1, wherein the thickness of the decorative sheet is 300 μm or more and 580 μm or less.

5. 3. The floor decorative material according to claim 1, wherein the decorative sheet has a surface protective layer on the side opposite to the side on which the backer layer is provided.

6. 6. The floor decorative material according to claim 5, wherein the surface protective layer is made of two or more ionizing radiation curable resin layers and has a total thickness of 10 μm or more and 50 μm or less.

7. 7. The decorative floor material according to claim 6, wherein each of the two or more ionizing radiation curable resin layers has a thickness of 5 μm or more and 25 μm or less.

8. 7. The floor decorative material according to claim 6, wherein the hardness of the ionizing radiation curable resin layer located on the farthest side from the side where the backer layer is provided is the highest among the two or more ionizing radiation curable resin layers.

9. The decorative sheet has a transparent resin layer between the backer layer and the surface protective layer, and the transparent resin layer contains a phosphorus-based flame retardant in an amount of 5% by mass or more and 15% by mass or less relative to the mass of the transparent resin layer.

10. The floor decorative material according to claim 1 or 2, further comprising a cork layer on the side of the wood substrate opposite to the side on which the cushion layer is provided.

11. The decorative floor material according to claim 1 or 2, wherein the surface on the side where the decorative sheet is provided has an uneven shape.

Images