Moisture-proof paper on the back of flooring materials and decorative flooring materials

Abstract

To provide rear face moisture-proof paper for a floor material which can suppress occurrence of warpage and pull-bending caused by humidity atmosphere.SOLUTION: Moisture-proof paper 2 includes a moisture-proof layer having a paper base material 2A, an anchor coat layer 2B containing first polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group and carboxylate, a vapor-deposited layer 2C, and an overcoat layer 2D containing second polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic acid anhydride group and carboxylate provided in this order. The moisture-proof paper 2 has moisture vapor permeability of 3.0 g / m2 24 hours or less, and can suppress occurrence of warpage and pull-bending in a decorative material 4 for a floor containing the moisture-proof paper 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to moisture-proof paper backing for flooring materials and a floor decorative material using the same. [Background technology]

[0002] Conventionally, floor decorative materials are constructed by attaching a decorative sheet onto a wood substrate.

[0003] Wood substrates for flooring include those obtained from high-quality logs (e.g., lauan plywood, a hardwood), but due to restrictions on timber harvesting and other factors, it is difficult to obtain logs, leading to a growing shortage of materials. This problem is particularly serious for hardwoods such as lauan. For this reason, efforts are being made to develop wood substrates that can be used in place of lauan plywood. Lauan alternatives include plywood, medium-density fiberboard (MDF), veneer, board materials, and other multilayered wood substrates. Commonly known are those in which a decorative sheet, printed with a solid print layer to provide hiding properties or a patterned layer to enhance design, is attached to the surface of the lauan alternative.

[0004] However, these lauan substitutes have the problem that they experience a larger dimensional change per 1% change in moisture content than lauan plywood, making them more susceptible to dimensional changes in response to changes in the surrounding environment. Specifically, the dimensional change per 1% moisture content of lauan plywood is 0.015 to 0.02%, while that of MDF and PB is around 0.045%, and that of softwood plywood (e.g., radiata pine) is around 0.025%. As a result, lauan substitutes are prone to warping and bending (the floor surface becoming misaligned) due to changes in humidity.

[0005] To solve the above problems, methods such as applying paint to the backside of the lauan substitute material to which a decorative sheet has been attached, attaching a synthetic resin sheet such as polyvinyl chloride, polyethylene, or polypropylene, or attaching a moisture-proof sheet made of paper / polyethylene / paper are known (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-193267 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-260109 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-097321 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the moisture-proof papers described in Patent Documents 1 to 3 have a moisture permeability of at most 20 g / m 2 On the other hand, as a surface decorative sheet, it has low moisture permeability (2 g / m 2 Because decorative sheets are often laminated (for periods of 24 hours or less), the degree of expansion and contraction on both sides is different. Therefore, if the moisture content of a wood-based substrate is lower than the equilibrium moisture content of the wood-based substrate under ambient conditions, the surface of the floor decorative material that is not laminated with the decorative sheet will absorb moisture, causing the surface to expand. If the moisture content is higher than the equilibrium moisture content of the wood-based substrate, the surface will release moisture and shrink. However, the surface laminated with the decorative sheet exhibits almost no moisture absorption or release, resulting in deformation (warping and dimensional changes) of the floor decorative material. Therefore, if such floor decorative materials are used for long periods as flooring, their performance is insufficient to prevent the warping and bending of lauan substitute materials. To prevent warping, the moisture permeability of the back surface (the surface not laminated with the decorative sheet) must be made the same as that of the front surface (the surface laminated with the decorative sheet).

[0008] Thus, even if a lauan substitute material with a dimensional change of more than 0.02% per 1% moisture content change is used as the wood substrate and a decorative sheet with low moisture permeability is laminated on one side to try to suppress warping and other problems in the lauan substitute material, this is not sufficient, and there is a need for the development of a decorative floor material that can further suppress the occurrence of warping and bending.

[0009] The present invention has been made to solve the above-mentioned unresolved problems, and aims to provide a moisture-proof backed paper for flooring and a decorative floor material that can suppress the occurrence of warping and bending due to a humid atmosphere, even when using a wood substrate whose dimensional change per 1% moisture content change is greater than 0.02%. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, according to one aspect of the present invention, there is provided a moisture-proof backed paper for flooring materials, which comprises a moisture-proof layer formed in this order: a paper base material; an anchor coat layer containing a first polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester; a vapor deposition layer; and an overcoat layer containing a second polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester. According to another aspect of the present invention, there is provided a floor decorative material comprising a wooden base material, a decorative sheet provided on one side of the wooden base material, and the above-mentioned aspect of moisture-proof backside paper for flooring provided on the other side of the wooden base material. [Effects of the Invention]

[0011] According to one aspect of the present invention, even if a wood substrate having a dimensional change of more than 0.02% per 1% moisture content change is used as the wood substrate, warping and other problems caused by a humid atmosphere can be suppressed. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view schematically illustrating an example of a floor decorative material according to one embodiment of the present invention. [Figure 2] FIG. 1 is a cross-sectional view schematically showing an example of moisture-proof paper included in a floor decorative material. [Figure 3] FIG. 1 is a cross-sectional view schematically showing an example of a decorative sheet included in a floor decorative material. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of each thickness, etc., differ from the actual ones. Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical idea of ​​the present invention, and the technical idea of ​​the present invention does not specify the materials, shapes, structures, etc. of the components as described below. The technical idea of ​​the present invention can be modified in various ways within the technical scope defined by the claims.

[0014] <Configuration> As shown in Figure 1, a floor decorative material 4 according to the present invention comprises a wooden substrate 1, a decorative sheet 3 provided on one surface (front surface) of the wooden substrate 1, and a moisture-proof paper for flooring back surface (hereinafter simply referred to as moisture-proof paper) 2 provided on the other surface (back surface) of the wooden substrate 1. The decorative sheet 3 and the moisture-proof paper 2 are attached to the wooden substrate 1 with an adhesive.

[0015] <Wood base material 1> The wood substrate 1 has a dimensional change of more than 0.02% per 1% moisture content change and an average moisture content of 6% to 10% by mass. A lauan substitute can be used as this wood substrate 1. Specifically, it is a material that can replace conventional lauan plywood, and examples of such materials include a substrate constructed by laminating at least one of medium-density fiberboard (MDF), high-density fiberboard (HDF), particleboard (PB), softwood plywood, and fast-growing tree plywood, or two or more boards selected from these boards. Examples of fast-growing trees include poplar, falcata, acacia, camellia, eucalyptus, and terminalia. These lauan substitutes have a dimensional change of more than 0.02% per 1% moisture content change.

[0016] In this embodiment, the "amount of dimensional change per 1% moisture content" is the amount of dimensional change measured by the following procedure. (1) Prepare a test piece of wood substrate 1 cut to 300 mm x 303 mm. (2) At room temperature (25°C), measure the current dimensions (lengths of the four sides) of the test piece with a vernier caliper. (3) The test piece is left in a 40°C oven (humidity-free, dry atmosphere ≒ 0% humidity) for one week. (4) After one week, measure the mass and dimensions (lengths of the four sides) of the test piece. (5) From the measurement data under both conditions, the dimensional change rate per 1% change in moisture content is calculated.

[0017] The thickness of the wood substrate 1 is not particularly limited, but is preferably about 2 mm or more and 15 mm or less, and more preferably about 2 mm or more and 12 mm or less. In this embodiment, in preparation for the case where the floor decorative material 4 is cut to suit the application location, it is preferable to use a wood substrate 1 having an average moisture content of 6% by mass or more and 10% by mass or less, and a moisture content in the center that is in the range of -1% to +2% compared to the moisture content in the peripheral parts.

[0018] When the size of the wood substrate 1 is, for example, approximately 150 mm long x 1840 mm wide (especially when the short side is 200 mm or less), warping and bending tend to occur due to a difference in moisture content between the center and periphery of the wood substrate 1. Therefore, by setting the moisture content characteristics of the wood substrate 1 to the above conditions, it is possible to prevent warping and bending even when the floor decorative material 4 is cut for use. A specific example of a situation in which the floor decorative material 4 is cut for use is when it is applied to a corner of a room (near a wall or around a pillar).

[0019] As mentioned above, the average moisture content of the wood substrate 1 is preferably 6% by mass or more and 10% by mass or less, and more preferably 6.5% by mass or more and 8.0% by mass or less. If the average moisture content is within the above range, it is easy to suppress the occurrence of bending or warping after cutting. In particular, when the floor decorative material is used for floor heating applications, it is preferable to set the average moisture content to 6% by mass or more and 9% by mass or less. The moisture content of the wood substrate 1 is preferably in the range of -1% to +2% in the center compared to the moisture content of the peripheral portion, and more preferably in the range of -0.5% to +1.0% in the center.

[0020] The peripheral part of the wooden substrate 1 refers to a 5 cm area around the wooden substrate 1, and the central part of the wooden substrate 1 refers to the inside of the wooden substrate 1 excluding the peripheral part. In addition, the average moisture content and moisture content difference (hereinafter, "moisture content difference" refers to the difference in moisture content between the peripheral part and the center part of the wood substrate 1) of the wood substrate 1 in this embodiment are values ​​measured by the following procedure. (A) Prepare a wooden substrate 1 measuring 303 mm in length and 1818 mm in width. (B) The area within 5 cm from the periphery of the wood base material 1 is defined as the peripheral area, and the area inside this is defined as the central area.

[0021] Thirty-five 5cm x 5cm samples were taken evenly from the wood substrate 1 prepared above, and the moisture content was measured using the total drying method. The total drying method involves leaving each sample in an oven at 105°C for three days, and then measuring the moisture content of each sample using the following calculation formula. The value before leaving is called pre-treatment, and the value after leaving is called post-treatment. Moisture content (%) = {(mass before treatment - mass after treatment) / mass after treatment} x 100 (C) The average value of the 35 samples is taken as the "average moisture content." (D) The "moisture content difference" is calculated by subtracting the average value of the samples (20 samples) from the average value of the samples (15 samples) in the center.

[0022] <Moisture-proof paper 2> Moisture-proof paper 2 has a moisture permeability of 3.0 g / m 2 - Less than 24 hours. The moisture permeability in this embodiment is measured in an environment of a temperature of 40°C and a humidity of 90% RH in accordance with JIS Z0208 (moisture permeability test method (cup method)). Hereinafter, the moisture permeability in this embodiment is measured under these conditions.

[0023] As shown in Figure 2, the moisture-proof paper 2 according to one embodiment of the present invention comprises a moisture-proof layer formed by laminating, in this order, a paper base material 2A, an anchor coat layer 2B which is a layer (PO layer) containing a first polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester, a vapor-deposited layer 2C, and an overcoat layer 2D which is a layer (PO layer) containing a second polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester. This results in a moisture permeability of 3.0 g / m 2 · It is possible to form the moisture-proof paper 2 so that the durability is 24 hours or less.

[0024] The floor decorative material 4 has a moisture permeability of 3.0 g / m 2 By providing moisture-proof paper 2, which has a moisture-proof property of 24 hours or less, on the back surface of the wooden substrate 1, the moisture permeability of the back surface of the wooden substrate 1 is significantly reduced. Therefore, even when a lauan substitute material with a dimensional change of more than 0.02% per 1% moisture content change is used as the wooden substrate 1 and a decorative sheet 3 with low moisture permeability is laminated on the surface, the moisture permeability of the back and front surfaces of the wooden substrate 1 can be set to be approximately the same. This allows the occurrence of warping and bending of the floor decorative material 4 to be sufficiently suppressed. The floor decorative material 4 according to this embodiment is suitable as a floor decorative material to be applied to the floor surfaces of various buildings and as a floor decorative material for special purposes such as floor heating.

[0025] [Paper base material 2A] The paper substrate (paper substrate layer) 2A is not particularly limited and may be selected appropriately, as long as it is paper whose main component is plant-derived pulp. Specific examples of the paper substrate 2A include fine paper, special fine paper, coated paper, art paper, cast-coated paper, construction paper, kraft paper, and glassine paper. The thickness of the paper substrate 2A may be, for example, 30 μm or more and 100 μm or less, or 30 μm or more and 70 μm or less. Furthermore, the thickness of the paper substrate 2A is preferably 50% or more of the overall thickness of the moisture-proof paper 2, and if it is 70% or more, it can be said to have excellent environmental compatibility. It is also preferable that at least one of the front and back surfaces of the moisture-proof paper 2 is provided with a primer layer for adhesion.

[0026] [Anchor coat layer 2B] The anchor coat layer (PO layer) 2B is provided on the surface of the paper substrate 2A to improve adhesion between the paper substrate 2A and the vapor-deposited layer 2C (described later) and to improve the gas barrier properties of the moisture-proof paper 2 as a gas barrier laminate. The anchor coat layer 2B contains a first polyolefin having at least one selected from a carboxyl group, a carboxyl group salt, a carboxylic anhydride group, and a carboxylic acid ester. This anchor coat layer 2B has excellent flexibility and can suppress cracking of the vapor-deposited layer 2C (described later) after bending (folding), while also improving adhesion between the anchor coat layer 2B and the vapor-deposited layer 2C. Furthermore, by including the above-mentioned polyolefin, the anchor coat layer 2B can form a dense film due to the crystallinity of the polyolefin. Furthermore, since polyolefins have few polar groups, a gas barrier laminate (i.e., moisture-proof paper 2) with excellent water vapor barrier properties can be obtained.

[0027] The anchor coat layer 2B may contain other components in addition to the first polyolefin, such as polyolefins other than the first polyolefin, silane coupling agents, organic titanates, polyacrylics, polyesters, polyurethanes, polycarbonates, polyureas, polyamides, polyimides, melamine, and phenols. The content of the first polyolefin in the anchor coat layer 2B may be, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass.

[0028] The thickness of the anchor coat layer 2B may be, for example, 1 μm or more and 20 μm or less, preferably 2 μm or more and 10 μm or less, and more preferably 2 μm or more and 5 μm or less. If the thickness of the anchor coat layer 2 is 1 μm or more, the irregularities of the paper base material 2A described above can be efficiently filled, and the vapor-deposited layer 2C can be uniformly laminated. Furthermore, if the thickness of the anchor coat layer 2B is 20 μm or less, the vapor-deposited layer 2C can be uniformly laminated while suppressing costs.

[0029] Examples of solvents contained in the coating liquid for the anchor coat layer 2B include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, and butyl acetate. These solvents may be used alone or in combination. Among these, from the viewpoint of properties, methyl alcohol, ethyl alcohol, isopropyl alcohol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferred. Furthermore, from the viewpoint of the environment, methyl alcohol, ethyl alcohol, isopropyl alcohol, and water are preferred.

[0030] The anchor coat layer 2B can be formed by applying a coating liquid containing at least the first polyolefin and a solvent to the paper substrate 2A and then drying it. The smaller the average particle size of the first polyolefin in the coating liquid, the better, from the viewpoints of smoothing the coating surface after drying, uniformly depositing the vapor-deposited layer 2C, and improving barrier properties. Specifically, the average particle size of the first polyolefin in the coating liquid may be 1 μm or less, preferably 0.7 μm or less, and more preferably 0.5 μm or less. The lower limit of the average particle size of the first polyolefin is not particularly limited, but may be, for example, 1 nm or more.

[0031] [Vapour-deposited layer 2C] The vapor-deposited layer 2C is a layer formed by vapor-depositing a metal or an inorganic compound. The vapor-deposited layer 2C may be obtained by vapor-depositing aluminum, or may contain aluminum oxide (AlOx), silicon oxide (SiOx), or the like. The thickness of the vapor-deposited layer 2C may be appropriately set depending on the intended use, but is preferably 10 nm to 300 nm, more preferably 30 nm to 100 nm. A thickness of 10 nm or more of the vapor-deposited layer 2C facilitates sufficient continuity of the vapor-deposited layer 2C, while a thickness of 300 nm or less adequately prevents curling and cracking, and facilitates achieving sufficient moisture resistance and flexibility.

[0032] From the viewpoint of oxygen gas barrier performance and film uniformity, the vapor deposition layer 2C is preferably formed by a vacuum film formation method. There are known film formation methods such as vacuum evaporation, sputtering, and chemical vapor deposition (CVD), but vacuum evaporation is preferred due to its fast film formation rate and high productivity. Among vacuum evaporation methods, electron beam heating is particularly effective because the film formation rate can be easily controlled by the irradiation area and electron beam current, and the temperature of the vapor deposition material can be increased or decreased in a short time.

[0033] [Overcoat layer 2D] The overcoat layer (PO layer) 2D containing polyolefin is provided on the surface of the vapor-deposited layer 2C so as to be in contact with the vapor-deposited layer 2C, and contains a second polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester. The overcoat layer 2D may contain other components in addition to the second polyolefin, such as a silane coupling agent, organic titanate, polyacrylic, polyester, polyurethane, polycarbonate, polyurea, polyamide, polyolefin emulsion, polyimide, melamine, and phenol.

[0034] The content of the second polyolefin in the overcoat layer 2D may be, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass. The thickness of the overcoat layer 2D may be, for example, from 0.05 μm to 20 μm, preferably from 0.5 μm to 10 μm, and more preferably from 1 μm to 5 μm. Furthermore, if the thickness of the overcoat layer 2D is 20 μm or less, it is possible to suppress costs while sufficiently exhibiting adhesion to the vapor deposition layer 2C and barrier properties.

[0035] Examples of solvents contained in the coating liquid for the overcoat layer 2D include water, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, n-pentyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, toluene, hexane, heptane, cyclohexane, acetone, methyl ethyl ketone, diethyl ether, dioxane, tetrahydrofuran, ethyl acetate, and butyl acetate. These solvents may be used alone or in combination. Among these, from the viewpoint of properties, methyl alcohol, ethyl alcohol, isopropyl alcohol, toluene, ethyl acetate, methyl ethyl ketone, and water are preferred. Furthermore, from the viewpoint of the environment, methyl alcohol, ethyl alcohol, isopropyl alcohol, and water are preferred.

[0036] The overcoat layer 2D can be formed by applying a coating liquid containing the second polyolefin and a solvent onto the vapor-deposited layer and drying it. The average particle size of the second polyolefin in the coating liquid is not particularly limited, but may be 1 μm or less, preferably 0.7 μm or less, and more preferably 0.5 μm or less.

[0037] The first polyolefin and the second polyolefin contained in the anchor coat layer 2B and the overcoat layer 2D, respectively, may be the same or different, but considering ease of production, it is preferable that they are the same. The overcoat layer 2D may contain other components in addition to polyolefin, as in the anchor coat layer 2B, which are the same as those in the anchor coat layer 2B. The overcoat layer 2D can be provided by applying a coating liquid containing the above-mentioned polyolefin and a solvent onto the vapor-deposited layer 2C and drying it.

[0038] The moisture-proof paper 2 according to this embodiment has a water vapor permeability (moisture permeability) of 3.0 g / m at 40°C and 90% RH. 2 - 24 hours or less, oxygen permeability at 30℃ and 70%RH is 3cc / m 2 ·24 hours·It is preferable that it is below ATM.

[0039] <Decorative sheet 3> The decorative sheet 3 is constructed by laminating, in this order from the side in contact with the wood substrate 1, a thermoplastic resin substrate sheet 3A, a printed layer 3B, a transparent resin layer 3C, a urethane resin layer 3D, and a urethane resin primer layer 3E. It is preferable that the transparent resin layer 3C, the urethane resin layer 3D, and the urethane resin primer layer 3E have sufficient transparency to allow the printed layer 3B to be seen from the urethane resin primer layer 3E side. The decorative sheet 3 has a moisture permeability of 7 g / m at a temperature of 40°C and a humidity of 90%. 2 24 hours or less is preferable, 5g / m 2 · 24 hours or less is even better.

[0040] [Base sheet 3A] The base sheet 3A is made of a thermoplastic resin. Examples of the base sheet 3A include synthetic resin sheets such as polyolefin, polyester, polyacrylic, polyamide, polyurethane, and polystyrene. Among these, polyolefin resins are preferred in terms of environmental compatibility, processability, and cost. The thickness of the base sheet 3A is preferably about 20 μm or more and 300 μm or less. The base sheet 3A may be colored as needed. The surface may also be subjected to a surface treatment such as corona discharge treatment, plasma treatment, or ozone treatment.

[0041] By using a polyolefin resin for the base sheet 3A, unlike fluorine-based resins, it can be incinerated without causing any problems. Polyethylene, polypropylene, or modified resins of these are commonly used as polyolefin resins, but polypropylene resins are preferred in consideration of surface hardness, heat resistance, etc. There are two types of polypropylene resins: random copolymer and homopolymer, and either can be used depending on the application. The base sheet 3A may also contain an ultraviolet absorber (benzotriazole, triazine, benzophenone, etc.) as a weather resistance agent. The amount added may vary depending on the desired weather resistance, but is preferably 0.1% by mass to 10% by mass, more preferably 1% by mass to 5% by mass, based on the resin solid content.

[0042] Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers such as 2-(2-hydroxy-5-t-butylphenyl)-2H-benzotriazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, and 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, as well as mixtures, modified products, polymers, and derivatives thereof. Examples of triazine-based ultraviolet absorbers include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol, 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-isooctyloxyphenyl)-s-triazine, as well as mixtures, modified products, polymers, and derivatives thereof. Examples of benzophenone-based absorbers include octabenzone, modified products, polymers, and derivatives thereof.

[0043] To prevent deterioration of the resin itself due to light, heat, water, etc., a hindered amine light stabilizer may be added to the base sheet 3A. The amount added may vary depending on the desired weather resistance, but is typically 0.1% to 10% by mass, preferably 1% to 5% by mass, based on the resin solids. Examples of hindered amine light stabilizers include bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, methyl(1,2,2,6,6-pentamethyl-4-poperidinyl)sebacate, decanedioic acid bis(2,2,6,6-tetramethyl-1(octyloxy)-4-piperidinyl)ester, and mixtures, modified products, polymers, and derivatives thereof.

[0044] The base sheet 3A can be obtained by appropriately blending the above materials and forming them into a film by extrusion molding, inflation molding, calendar molding, etc. The thickness of the base sheet 3A is preferably about 30 μm or more and 120 μm or less, taking into consideration ease of adhesive lamination processing, weather resistance, transparency, etc.

[0045] When titanium oxide is used in the base sheet 3A to function as a concealing layer, the total content of titanium oxide as the concealing layer and the added titanium oxide should be 23 parts by mass or more. When the base sheet 3A contains 23 parts by mass or more of titanium oxide as the concealing layer, no further titanium oxide may be added. However, if too much titanium oxide is added to the base sheet 3A, the titanium oxide will affect the film quality of the base sheet 3A, so the preferred content of titanium oxide in the base sheet 3A is 23 parts by mass or more and 40 parts by mass or less.

[0046] 3, titanium oxide may be applied to the surface of the base sheet 3A that contacts the printed layer 3B, providing a titanium oxide layer between the base sheet 3A and the printed layer 3B. Even when a titanium oxide layer is provided, the heat insulation properties of the base sheet 3A for the wood base material 1 are improved as long as the base sheet 3A contains 23 parts by mass or more of titanium oxide due to the titanium oxide layer. Under these conditions, the thickness of the titanium oxide layer is preferably 5 μm or more and 10 μm or less.

[0047] [Printing layer 3B] The printed layer 3B is provided for the purpose of imparting a desired design to the target decorative sheet 3. In this embodiment, the printed layer 3B having an appropriate design is provided on one surface of the base sheet 3A by means of a printing method or the like. The printed layer 3B is provided on the base sheet 3A using a suitable ink. Specifically, if the base sheet 3A made of a thermoplastic resin is made of polypropylene resin, a mixture of urethane resin and vinyl chloride-vinyl acetate copolymer resin is preferably used.

[0048] As the colorant for the printed layer 3B, a perylene-based black pigment is used, particularly as a black pigment. A typical perylene-based black pigment is perylene black. In this respect, this embodiment can improve the problem that existing decorative sheets 3 often use carbon black as a black pigment, which has low reflectance in the near-infrared light region (0.781 μm to 2.5 μm), resulting in heat storage due to the absorption of heat by infrared light. In addition, as a pigment other than the black pigment, at least one of isoindolinone, disazo, polyazo, diketopyrrolopyrrole, quinacridone, phthalocyanine, and titanium oxide is used in the printing layer 3B.

[0049] There are no particular limitations on the method for forming the printed layer 3B, and various conventionally known printing methods can be used, such as gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and ink-jet printing. Furthermore, in the case of a solid overall surface, in addition to the various printing methods described above, various coating methods can be used, such as roll coating, knife coating, air knife coating, die coating, lip coating, comma coating, kiss coating, flow coating, and dip coating. Other methods that can be used include hand-drawing, ink-flow printing, photography, laser beam or electron beam drawing, partial vapor deposition of metal or the like, and etching, as well as a combination of these methods.

[0050] Furthermore, prior to forming the printed layer 3B, if necessary, the surface of the base sheet 3A on which the printed layer 3B will be laminated may be subjected to a surface treatment such as corona treatment, ozone treatment, plasma treatment, ionizing radiation treatment, dichromate treatment, anchor or primer treatment, etc., to improve adhesion between the base sheet 3A and the printed layer 3B. There are no particular restrictions on the type of pattern that the printed layer 3B comprises, and it can be a wood grain pattern, a stone pattern, a fabric pattern, an abstract pattern, a geometric pattern, etc., which have traditionally been widely used in the field of decorative sheets 3, or a solid color if the purpose is simply to color or adjust the color; in short, any desired pattern can be adopted depending on the intended use of the decorative sheet 3.

[0051] [Transparent resin layer 3C] The transparent resin layer 3C is made of a transparent thermoplastic resin. Examples of materials for the transparent resin layer 3C include polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ionomer, acrylic acid ester, and methacrylic acid ester. Among these, polyolefin resins such as polypropylene are preferred. The transparent resin layer 3C may contain various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, UV absorbers, light stabilizers, radical scavengers, and soft components (e.g., rubber).

[0052] [Urethane resin layer 3D] The urethane-based resin layer 3D is made of, for example, a recoatable resin layer. The recoatable resin layer is made of a two-component curing urethane resin and is a layer that imparts recoatability to the surface of the topcoat layer (described below) with a post-coating electron beam or ultraviolet curing resin. The urethane resin of the recoatable resin layer is preferably a polyester polyol, and cellulose acetate butyrate is mixed with the polyester polyol as a blocking agent, and silica as a filler and antifoaming agent, and non-yellowing polyisocyanate as a curing agent are also added.

[0053] [Urethane resin primer layer 3E] The urethane resin primer layer 3E is made of a urethane resin. The urethane resin primer layer 3E is provided to further improve the adhesion of the urethane resin layer 3D. The urethane resin primer layer 3E is not necessarily provided.

[0054] In the decorative floor material 4 having the above-described configuration, known adhesives can be used to laminate the decorative sheet 3 to the wood substrate 1. Examples of adhesives include those containing polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ionomer, butadiene-acrylonitrile rubber, neoprene rubber, natural rubber, etc. as active ingredients. The thickness of the adhesive layer is not limited, but is preferably between 0.1 μm and 50 μm.

[0055] The floor decorative material 4 described above is appropriately post-coated with a coating liquid containing an ionizing radiation curable resin when used as a floor material or while being used as a floor material, and a top coat layer (not shown) is separately applied as a protective layer. The top coat layer is provided to impart surface properties such as scratch resistance, abrasion resistance, water resistance, and stain resistance required of the decorative sheet 3. As the resin for forming this top coat layer, an ionizing radiation curable resin is preferred from the viewpoints of high surface hardness, productivity, etc.

[0056] The ionizing radiation-curable resin is not limited as long as it undergoes a crosslinking polymerization reaction upon irradiation with ionizing radiation and changes into a three-dimensional polymer structure. For example, one or more prepolymers, oligomers, and monomers having a polymerizable unsaturated bond or epoxy group in the molecule that can be crosslinked upon irradiation with ionizing radiation can be used. Examples include acrylate resins such as urethane acrylate, polyester acrylate, and epoxy acrylate; silicon resins such as siloxane; polyester resins; and epoxy resins.

[0057] Ionizing radiation includes visible light, ultraviolet light (near ultraviolet light, vacuum ultraviolet light, etc.), X-rays, electron beams, ion beams, etc., and among these, ultraviolet light and electron beams are preferred. Usable ultraviolet light sources include ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, black light fluorescent lamps, and metal halide lamps. The wavelength of ultraviolet light is approximately 190 to 380 nm.

[0058] As the electron beam source, various electron beam accelerators can be used, such as Cockcroft-Waldt type, Van de Graaf type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, and high frequency type. The energy of the electron beam is preferably about 100 keV to 1000 keV, more preferably about 100 keV to 300 keV. The dose of the electron beam is preferably about 2 Mrad to 15 Mrad. Ionizing radiation curable resins are sufficiently cured by irradiation with electron beams, but when curing is performed by irradiation with ultraviolet rays, it is preferable to add a photopolymerization initiator (sensitizer).

[0059] For resin systems having radically polymerizable unsaturated groups, the photopolymerization initiator may be at least one of acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, Michler's benzoyl benzoate, Michler's ketone, diphenyl sulfide, dibenzyl disulfide, diethyl oxide, triphenyl biimidazole, isopropyl-N,N-dimethylaminobenzoate, etc. For resin systems having cationically polymerizable functional groups, the photopolymerization initiator may be at least one of aromatic diazonium salts, aromatic sulfonium salts, metallocene compounds, benzoin sulfonate esters, furyloxysulfoxonium diallyliodosyl salts, etc.

[0060] The amount of the photopolymerization initiator added is not particularly limited, but is generally about 0.1 to 10 parts by mass per 100 parts by mass of the ionizing radiation curable resin. The top coat layer can be formed from an ionizing radiation curable resin by, for example, applying a solution of the ionizing radiation curable resin by a coating method such as gravure coating or roll coating. The amount of the solution applied is generally 5 μm or more and 30 μm or less, and preferably 5 μm or more and 20 μm or less, in terms of solid content.

[0061] To further impart scratch resistance and abrasion resistance to a top coat layer formed from an ionizing radiation-curable resin, an inorganic filler may be blended in. Examples of inorganic fillers include powdered aluminum oxide, silicon carbide, silicon dioxide, calcium titanate, barium titanate, magnesium pyroborate, zinc oxide, silicon nitride, zirconium oxide, chromium oxide, iron oxide, boron nitride, diamond, emery sand, and glass fiber. The amount of inorganic filler added is about 1 part by mass or more and 80 parts by mass or less per 100 parts by mass of the ionizing radiation curable resin.

[0062] <Effects> The floor decorative material 4 according to one embodiment of the present invention has the following advantages. (1) Floor decorative material 4 has a moisture permeability of 3.0 g / m 2 ·Has moisture-proof paper 2 that is less than 24 hours. With this configuration, the floor decorative material 4 has low moisture permeability on the back surface of the wood substrate 1. Therefore, even when a lauan substitute material with a dimensional change of more than 0.02% per 1% moisture content change is used as the wood substrate 1 and a decorative sheet 3 is laminated on the surface, it is possible to set the moisture permeability on one side and the other side of the wood substrate 1 to be approximately the same. As a result, the occurrence of warping or bending of the floor decorative material 4 can be sufficiently suppressed. Such a floor decorative material 4 according to one embodiment of the present invention is suitable as a floor decorative material to be applied to the floor surfaces of various buildings and as a floor decorative material for special purposes such as floor heating.

[0063] (2) The floor decorative material 4 according to one embodiment of the present invention allows for free pattern expression using the printed layer 3B of the decorative sheet 3, and therefore flooring materials with special designs unique to rare wood species such as birch and cherry, which have pale white textures and are difficult to procure in large quantities due to quantitative constraints on natural resources, can be mass-produced inexpensively without problems such as color differences.

[0064] (3) When the urethane-based resin constituting the urethane-based resin layer 3D of the decorative sheet 3 is composed of a polyester-based polyol in particular, a topcoat layer is formed on the side of the decorative sheet 3 opposite the wood substrate 1, and when an ionizing radiation curable resin is applied as a post-coat and cured by irradiating it with ultraviolet light, part of the urethane-based resin undergoes UV cross-linking. Therefore, even if a top coat layer is formed by post-coating with an ionizing radiation curable resin, a floor decorative material 4 with excellent adhesion to the top coat layer can be obtained. In other words, a floor decorative material 4 with excellent suitability for post-coating can be provided.

[0065] That is, in the decorative sheet 3, a top coat layer made of an electron beam or ultraviolet curable resin can be formed on the surface opposite the base sheet 3A in a subsequent process, thereby imparting sufficient surface hardness and abrasion resistance to withstand rubbing against the user's body, belongings, furniture, and fixtures when used as a flooring material. In particular, when the top coat layer is composed of multiple layers, adding abrasion-resistant hard particles to appropriate layers can further improve surface hardness and abrasion resistance and also impart slip resistance. Furthermore, adding an antiviral agent to the top coat layer can also impart antiviral properties to the floor decorative material 4.

[0066] Furthermore, since the transparent resin layer 3C exists between the top coat layer formed in a later process and the printed layer 3B, even if the top coat layer is worn away due to some excessive disturbance from the surface, the printed layer 3B is protected by the transparent resin layer 3C, and therefore the image on the printed layer 3B will not be worn away unless all of the transparent resin layer 3C is worn away, so the layer can withstand wear from the surface for a long period of time.

[0067] Furthermore, in one embodiment of the present invention, the decorative floor material 4 in which this decorative sheet 3 is applied to a wooden substrate 1 not only retains the various advantages of the decorative floor sheet 3 described above, but also has the following excellent practical advantages when a top coat layer is formed in a subsequent process, since the substrate sheet 3A and transparent resin layer 3C made of a thermoplastic resin such as an olefin resin are interposed between the wooden substrate 1 as the substrate for flooring and the top coat layer made of a high-hardness electron beam or ultraviolet curable resin.

[0068] In other words, when looking at the physical properties of the surface of the floor decorative material 4, the hardness of the top coat layer made of electron beam or ultraviolet curable resin is moderately mitigated by the base sheet 3A and transparent resin layer 3C made of thermoplastic resin, resulting in excellent impact absorption and walkability as a flooring material, and also making it possible to maintain a moderate heat storage effect due to the low thermal conductivity of the thermoplastic resin. [Example]

[0069] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples in any way. Example 1 [Decorative sheet 3] The decorative sheet 3 of Example 1 was produced as follows. A 60 μm thick colored unstretched polypropylene resin film was used as the base sheet 3A, and one side of the base sheet 3A was subjected to corona treatment to adjust the wetting index to 38 dyn / cm or more.A concealing layer and a wood grain pattern printing layer 3B were sequentially printed on this corona-treated surface using a gravure printing method with a urethane resin-based ink.

[0070] Next, a 20 μm thick ethylene-ethyl acrylate copolymer adhesive resin layer and a 90 μm thick random copolymer polypropylene resin containing 0.2% by mass of a light stabilizer and 0.3% by mass of an ultraviolet absorber were co-extrusion laminated onto the printed layer 3B to form a two-layer transparent resin layer 3C, which was then embossed with a vascular pattern using a metal embossing roll. After cooling and solidifying, the surface of the transparent resin layer 3C was corona treated to adjust the wetting index to 38 dyn / cm or more, and a two-component curing urethane resin was applied to the entire surface by gravure coating to a coating amount of 2 g / m after drying. 2 The resulting layer was dried and hardened to form a recoatable resin layer, that is, a urethane resin layer 3D, and the surface of the transparent resin layer 3C was made suitable for recoating with an electron beam or ultraviolet curable resin.

[0071] Thereafter, the back surface of the substrate sheet 3A (i.e., the surface opposite to the printed layer 3B) is subjected to a corona treatment to adjust the wetting index to 38 dyn / cm or more, and then a urethane resin primer agent containing silica powder is applied onto the urethane resin layer 3D by a gravure coating method in an amount of 1 g / m after drying. 2 was applied to form a urethane resin primer layer 3E, thereby producing a decorative floor sheet 3 before forming a top coat layer, which was then wound up in a roll. In this manner, the decorative sheet 3 used in Example 1 was produced.

[0072] After a few days, an acrylic ultraviolet curable resin was applied as a top coat layer on the urethane resin primer layer 3E of the decorative sheet 3 by gravure coating, with a coating amount of 3 g / m after curing. 2 Two layers were applied and cured so as to form a top coat layer consisting of two layers, an undercoat layer and a top coat layer, with a total thickness of 100 μm, thereby producing a decorative sheet 3 with a top coat layer. This decorative sheet 3 was attached to one side of a 5.5 mm thick MDF (wood substrate 1) using an adhesive (BA·10L / BA-11B, 9 g / square shaku) manufactured by Javan Coating Resin Co., Ltd. The dimensional change rate of the MDF per 1% moisture content change was 0.05%. Note that a shaku-kaku indicates the area of ​​a plane that is 303mm long x 303mm wide (same below).

[0073] [Moisture-proof paper 2] Clay-coated paper (55 g / m) as paper substrate 2A 2 A coating liquid containing a carboxyl group salt (product name: Chemipearl S100, ionomer-based, particle size (average particle size): 0.1 μm, solvent: water, IPA (isopropyl alcohol), manufactured by Mitsui Chemicals, Inc.) was applied onto the surface of the substrate using a bar coater, and the substrate was dried in an oven to form an anchor coat layer 2B. The thickness of the anchor coat layer 2B was 3 μm.

[0074] Next, aluminum was vapor-deposited onto the anchor coat layer 2B to form a vapor-deposited layer 2C. The thickness of the vapor-deposited layer 2C was 50 nm. A solution containing a carboxyl group salt (product name: Chemipearl S100, ionomer-based, particle size (average particle size): 0.1 μm, solvent: water, IPA, manufactured by Mitsui Chemicals, Inc.) was then applied onto the vapor-deposited layer 2C using a bar coater and dried in an oven to form an overcoat layer 2D, thereby obtaining a gas barrier laminate, i.e., moisture-proof paper 2. The thickness of the overcoat layer 2D was 3 μm. The weight of the paper substrate 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 82% by mass. A moisture-proof paper 2 was attached to the side of the MDF (wood base material 1) opposite the decorative sheet 3 using an adhesive (BA·10L / BA-11B, 9g / square foot) manufactured by Javan Coating Resin Co., Ltd., to create the floor decorative material 4 of Example 1.

[0075] <Example 2> A floor decorative material 4 was produced in the same manner as in Example 1, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Except for forming the anchor coat layer 2B from a solution containing a carboxyl group salt (product name: Chemipearl S300, ionomer-based, particle size (average particle size): 0.5 μm, solvent: water, IPA, manufactured by Mitsui Chemicals, Inc.), moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 1. The weight of the paper substrate 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 82 mass %.

[0076] Example 3 A floor decorative material 4 was produced in the same manner as in Example 1, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Except for forming the anchor coat layer 2B from a solution containing a carboxyl salt (product name: Chemipearl S500, ionomer-based, particle size (average particle size): 0.7 μm, solvent: water, IPA, manufactured by Mitsui Chemicals, Inc.), moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 1. The weight of the paper substrate 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 82 mass %.

[0077] Example 4 A floor decorative material 4 was produced in the same manner as in Example 1, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Except for changing the thickness of the anchor coat layer 2B to 1 μm, moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 1. The weight of the paper base material 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 85 mass %.

[0078] <Example 5> A floor decorative material 4 was produced in the same manner as in Example 1, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Except for using silica as the vapor-deposited layer 2C, moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 1. The weight of the paper base material 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 82 mass %.

[0079] Example 6 A floor decorative material 4 was produced in the same manner as in Example 1, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Except for using alumina as the vapor-deposited layer 2C, moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 1. The weight of the paper base material 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 82 mass %.

[0080] <Comparative Example 1> A floor decorative material 4 was produced in the same manner as in Example 2, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Except for forming the anchor coat layer 2B from a solution containing a carboxyl salt (product name: Chemipearl S300, ionomer-based, particle size (average particle size): 6 μm, solvent: water, IPA, manufactured by Mitsui Chemicals, Inc.), moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 2. The weight of the paper substrate 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 82 mass%.

[0081] <Comparative Example 2> A floor decorative material 4 was produced in the same manner as in Example 4, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Except for changing the thickness of the overcoat layer 2D to 1 μm, moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 4. The weight of the paper base material 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 88 mass %.

[0082] <Comparative Example 3> A floor decorative material 4 was produced in the same manner as in Example 2, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 2, except that the anchor coat layer 2B was formed from a solution containing a carboxyl salt (trade name: Chemipearl S300, ionomer-based, particle size (average particle size): 6 μm, solvent: water, IPA, manufactured by Mitsui Chemicals, Inc.) and the overcoat layer 2D was formed from a solution containing a carboxyl salt (trade name: Chemipearl S300, ionomer-based, particle size (average particle size): 6 μm, solvent: water, IPA, manufactured by Mitsui Chemicals, Inc.). The weight of the paper substrate 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 82 mass%.

[0083] <Comparative Example 4> A floor decorative material 4 was produced in the same manner as in Example 1, except that the moisture-proof paper 2 was different. The moisture-proof paper 2 was prepared by the following procedure. Except for forming the overcoat layer 2D from a solution containing a carboxyl salt (product name: Chemipearl S300, ionomer-based, particle size (average particle size): 6 μm, solvent: water, IPA, manufactured by Mitsui Chemicals, Inc.), moisture-proof paper (gas barrier laminate) 2 was obtained in the same manner as in Example 2. The weight of the paper substrate 2A in the moisture-proof paper (gas barrier laminate) 2 was approximately 82 mass %.

[0084] <Performance comparison> Moisture-proof performance The moisture permeability of the moisture-proof papers 2 produced in Examples 1 to 6 and Comparative Examples 1 to 4 was calculated in accordance with JIS Z 0208 "Test method for moisture permeability of moisture-proof materials (cup method)." The unit of moisture permeability is g / m. 2 24 hours, 3.0g / m 2 -If it is more than 24 hours, mark it as "×", 3.0g / m 2 - Less than 24 hours was marked as "Good." The evaluation results are shown in Table 1.

[0085] ·warp A comparative warpage test was conducted using the floor decorative materials 4 produced in Examples 1 to 6 and Comparative Examples 1 to 4. The floor decorative materials 4 were left for two weeks in a thermo-hygrostat at a temperature of 40°C and a humidity of 40%, and if the maximum warpage of the floor decorative material 4 in the width direction in a hygroscopic state was less than 0.5 mm, it was evaluated as "Good", and if it was 0.5 mm or more, it was evaluated as "Poor". The planar dimensions of the floor decorative material 4 were 303 mm x 1818 mm.

[0086] Warpage was measured using a measuring jig. The vertical change (mm) at the center of the width direction was taken as the warpage value, with a plus sign indicating convex warpage and a minus sign indicating concave warpage. The evaluation results are shown in Table 1.

[0087] [Table 1]

[0088] The results in Table 1 verify that the moisture-proof paper 2 of the floor decorative material 4 according to one embodiment of the present invention has excellent moisture-proof performance, and the results also show that the warping of the floor decorative material 4 is correlated with its moisture-proofing properties. In this way, in the floor decorative material 4 according to one embodiment of the present invention, the moisture-proof paper 2 effectively prevents dimensional changes in the wood substrate 1 due to humidity. Furthermore, by using the moisture-proof paper 2 according to one embodiment of the present invention, sufficient warping prevention effects can be achieved even in a floor decorative material 4 in which a decorative sheet 3 is used on one side of a wooden substrate 1.

[0089] The heat-shielding performance of the floor decorative material 4 of Example 1 was measured using the method for measuring the solar reflectance of a coating film specified in JIS standard K5602. The measurement was carried out using a spectrophotometer UV3600 (product name) manufactured by Shimadzu Corporation. It was confirmed that the solar reflectance of the coating film was 40% or more according to the JIS standard K5602.

[0090] Furthermore, the decorative sheet 3 used in the floor decorative material 4 of Example 1 was attached to one surface of an unpainted steel plate measuring 21 cm in length, 29.7 cm in width, and 0.5 mm in thickness using an adhesive to prepare a test specimen. A halogen bulb was then placed directly above the surface of the test specimen, 15 cm away from the surface. The temperatures of the front and back surfaces of the test specimen were measured every minute while irradiating the specimen with halogen light for 120 minutes, and the maximum temperature was recorded. The records confirmed that the maximum temperature was below 60°C. [Explanation of symbols]

[0091] 1 Wood base material 2. Moisture-proof paper 2A Paper base material 2B anchor coat layer 2C vapor deposited layer 2D overcoat layer 3 Decorative sheets 3A base sheet 3B printing layer 3C transparent resin layer 3D urethane resin layer 3E Urethane resin primer layer 4. Floor covering materials

Claims

1. A paper substrate; an anchor coat layer containing a first polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester; a deposition layer; an overcoat layer containing a second polyolefin having at least one selected from a carboxyl group, a salt of a carboxyl group, a carboxylic anhydride group, and a carboxylic acid ester; The moisture-proof layer includes the following layers arranged in this order: A moisture-proof backing paper for flooring, characterized in that the moisture permeability is 3.0 g / m 2 ·24 hours or less.

2. 2. The moisture-proof backed paper for flooring materials according to claim 1, wherein the thickness of the anchor coat layer is 1 μm or more.

3. 3. The moisture-proof backed paper for flooring materials according to claim 1, wherein the weight of the paper substrate is 50% by mass or more based on the weight of the moisture-proof backed paper for flooring materials.

4. A wood substrate and a decorative sheet provided on one surface of the wood base material; A floor decorative material comprising: the moisture-proof backing paper for flooring according to any one of claims 1 to 3, provided on the other surface of the wood substrate.

5. The wood base material has a dimensional change of more than 0.02% per 1% moisture content change, and an average moisture content in the range of 6% by mass or more and 10% by mass or less, The decorative sheet is a floor decorative material as described in claim 4, characterized in that it includes a laminate having a base sheet made of a thermoplastic resin provided on one side of the wood base material, a printed layer, a transparent resin layer, and a urethane-based resin layer provided in this order.

6. The floor decorative material according to claim 5, characterized in that the wood base material is made of a laminate of one or more boards selected from the group consisting of medium density wood fiberboard (MDF), high density wood fiberboard (HDF), particle board (PB), softwood plywood and fast-growing tree plywood.

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