JP2016075141A - Decorative material for floor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative material for a floor for restraining the occurrence of warping and pull-bending, even when laminating a decorative sheet of low moisture permeability on its obverse surface, by using a lauan substitution material larger than 0.02% in a dimensional variation per a 1% moisture content change as a wooden base material.SOLUTION: A decorative material for a floor is provided for laminating a moisture preventive film 5 on a reverse surface of a wooden base material 3, by laminating a decorative sheet 1 on an obverse surface of the woden base material 3, and in the decorative material for the floor, (1) the wooden base material 3 is larger than 0.02% in a dimensional variation per a 1% moisture content change, (2)a moisture preventive film 5 is 7 g/m2.24 hours or less in moisture permeability, (3)a decorative sheet 1 is 7 g/m2.24 hours or less in moisture permeability and (4) the wooden base material 3 is 6-10 wt.% in the average moisture content.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a floor decorative material in which warping and curving are suppressed.

  Conventionally, as a wood-based decorative board used as a decorative material for a floor of a house, it has a natural wood design via an adhesive on the upper surface of a wooden base material (for example, hardwood lauan plywood) obtained from a good quality log. The thing which stuck the decorative sheet is known.

  As the woody base material, the above-mentioned hardwood lauan is frequently used. However, in recent years, raw materials are difficult to obtain due to lack of natural resources, timber cutting restrictions, etc., and the material shortage is progressing. This problem is particularly acute for hardwoods such as Lauan. Therefore, the development of a wood base material that can be used in place of the Lauan plywood is being promoted. Examples of Lawan alternative materials include softwood plywood, wood fiber separated from wood-based waste wood, or wood board obtained by molding and solidifying wood fragments with an adhesive (for example, medium density wood fiber board: MDF, high density wood fiber board) : HDF, particle board: PB), there is an early-wood plywood made of early-wood.

  However, these lauan alternative materials have a problem that the dimensional change amount per 1% moisture content change is larger than that of the lauan plywood, and the dimensional change easily occurs according to the change of the surrounding environment. Specifically, the amount of dimensional change per 1% moisture content of Lauan plywood is 0.015 to 0.02%, but about 0.045% for MDF and PB, and 0 for softwood plywood (for example, Radiata Pine). It is about 0.025%. For this reason, the Lawan alternative material has a characteristic that warp and bend (the right angle of the floor surface shifts) easily occur due to changes in humidity.

In order to improve the above problem, it has been proposed to laminate a moisture-proof sheet on the back surface of the Lawan alternative material (for example, Patent Documents 1 to 3). However, the moisture-proof sheets described in Patent Documents 1 to 3 have a moisture permeability of about 20 g / m ² · 24 hours at the most, and the performance is insufficient to prevent warping and bending of the Lauan alternative material. In recent years, in particular, a decorative sheet having a low water vapor transmission rate (2 g / m ² · 24 hours or less) is often laminated on the front surface of the Lawan alternative material, so that the water vapor transmission rate on the back surface is equal to or higher than that of the front surface. There is a need to reduce moisture permeability.

  From the above, even when a lauan substitute material having a dimensional change per 1% moisture content change larger than 0.02% is used as a wooden base material and a decorative sheet with low moisture permeability is laminated on the front surface, Development of a decorative material for floors in which the occurrence of warping and curving is suppressed is desired.

JP 2001-193267 A JP 2001-260109 A JP 2006-097321 A

  The present invention uses a Lauan alternative material whose dimensional change per 1% moisture content change is larger than 0.02% as a wooden base material, and even when a decorative sheet with low moisture permeability is laminated on the front surface. An object of the present invention is to provide a floor decorative material in which the occurrence of warping and curving is suppressed.

  As a result of intensive studies, the present inventor has found that the above object can be achieved when a specific moisture-proof film is used, and has completed the present invention.

That is, the present invention relates to the following floor decorative material.
1. A decorative sheet for flooring in which a decorative sheet is laminated on the front surface of the wooden substrate, and a moisture-proof film is laminated on the back surface of the wooden substrate,
(1) The wooden base material has a dimensional change per 1% moisture content change larger than 0.02%, (2) the moisture-proof film has a moisture permeability of 7 g / m ² · 24 hours or less,
(3) The decorative sheet has a moisture permeability of 7 g / m ² · 24 hours or less,
(4) The wooden substrate has an average moisture content of 6 to 10% by weight.
A decorative material for floors.
2. The wood substrate is at least one selected from the group consisting of medium density wood fiber board (MDF), high density wood fiber board (HDF), particle board (PB), softwood plywood, and early-wood plywood, Item 10. The floor decorative material according to Item 1.
3. Item 3. The floor decorative material according to Item 1 or 2, wherein the moisture-proof film has at least a synthetic resin base material layer and a vapor deposition layer.
4). Item 4. The floor decorative material according to Item 3, wherein the moisture-proof film has a primer layer between the synthetic resin substrate layer and the vapor deposition layer.
5. Item 4. The floor decorative material according to Item 3, wherein the moisture-proof film is composed of the synthetic resin base material layer / primer layer / the deposited layer / surface coat layer.
6). Item 6. The floor decorative material according to any one of Items 3 to 5, further comprising a primer layer on one or both surfaces of the moisture-proof film.
7). The floor decorative material according to any one of Items 1 to 6, wherein the decorative sheet and the moisture-proof film are laminated on the wooden base material with an adhesive.
8). The floor decorative material according to any one of Items 1 to 7, which is a floor heating floor material.

  Hereinafter, the floor decorative material of the present invention will be described in detail.

The flooring decorative material of the present invention is a flooring decorative material in which a decorative sheet is laminated on the front surface of a wooden substrate, and a moisture-proof film is laminated on the back surface of the wooden substrate,
(1) The wooden base material has a dimensional change per 1% moisture content change larger than 0.02%, and (2) the moisture-proof film has a moisture permeability of 7 g / m ² · 24 hours or less. It is characterized by. The moisture permeability is a measured value in an environment of a temperature of 40 ° C. and a humidity of 90% RH according to JIS Z0208 (moisture permeability test method (cup method)). Hereinafter, the moisture permeability in the present specification indicates a measured value under the conditions.

The floor decorative material of the present invention having the above characteristics has a moisture-proof film having a moisture permeability of 7 g / m ² · 24 hours or less, so that the moisture permeability of the back surface of the wooden substrate is kept low. Therefore, even when a laminating substitute material with a dimensional change per 1% moisture content change larger than 0.02% is used as a wooden base material and a decorative sheet with low moisture permeability is laminated on the front surface, the wooden base Since the moisture permeability of the front surface and the back surface of the material can be set to the same level, the occurrence of warping and bending of the floor decorative material is sufficiently suppressed. Such a flooring material of the present invention is suitable as a flooring material to be constructed on the floor surface of various buildings and as a flooring material used for floor heating as a special application.

Hereinafter, each structure of the decorative material for floors of this invention is demonstrated.
(Wood base)
As the woody base material of the present invention, a Lawan alternative material is used. In other words, it is a material that replaces the conventional lauan plywood and the like, for example, at least one of medium density wood fiber board (MDF), high density wood fiber board (HDF), particle board (PB), softwood plywood, and early mature plywood Use seeds. Examples of early mature trees include poplar, falkata, acacia, chamelere, eucalyptus, terminaria and the like. These Lauan alternative materials have a dimensional change per 1% moisture content change greater than 0.02%.

In addition, the “dimensional change per 1% water content” in the present specification is a dimensional change measured by the following procedure.
(1) Prepare a test piece of wood base material cut to 300 mm × 303 mm.
(2) In a normal temperature (25 ° C.) environment, the current dimensions (length of four sides) of the test piece are measured with a caliper. (3) The test piece is left in a 40 ° C. oven (humidity free, dry atmosphere≈0%) for one week.
(4) After one week, the weight and dimensions (length of four sides) of the test piece are measured.
(5) The dimensional change rate per 1% moisture content change is measured from the measurement data of both conditions.

  The thickness of the wooden substrate is not particularly limited, but is preferably about 2 to 15 mm, and more preferably about 2 to 12 mm.

  In the present invention, an average moisture content is 6 to 10% by weight as a wooden base material, and the moisture content in the central part is the peripheral part in preparation for the case where the flooring decorative material is cut and used depending on the construction site. It is preferable to use a wooden substrate having a range of -1% to + 2% compared to the moisture content. When the size of the wood base material is, for example, about 150 mm long × 1840 mm wide (especially, the length of the short side is 200 mm or less), the warp or curl due to the deviation of the moisture content between the central part and the peripheral part of the wooden base material Is likely to occur. Therefore, by setting the moisture content characteristic of the wooden base material to the above-described conditions, it is possible to suppress the occurrence of warping and curving even when the floor decorative material is cut and used. In addition, as a case where the decorative material for floors is cut and used, specifically, a case where the floor decorative material is applied to a corner portion of a room where the decorative material for flooring is applied (by the wall or around the pillar) is assumed.

  The average moisture content of the wooden substrate is preferably 6 to 10% by weight, and more preferably 6.5 to 8% by weight. If the average moisture content is within the above range, it is easy to suppress the occurrence of curving and warping after cutting. Among these, when using the flooring decorative material for floor heating, it is preferable to set the average moisture content to 6 to 9% by weight.

  The moisture content of the wood base material is preferably in the range of -1% to + 2%, and in the range of -0.5% to + 1%, as compared with the moisture content of the central part. Is more preferable. In addition, the peripheral part of a wooden base material means the range of 5 cm around a wooden base material, and the center part of a wooden base material means the inside of the wooden base material except the said peripheral part.

In addition, the average moisture content and moisture content difference (hereinafter, “moisture content difference” in the present specification indicates the moisture content difference between the peripheral portion and the central portion of the wood substrate) is measured by the following procedure. Is the value to be
(A) As shown in FIG. 3, a woody base material having a length of 303 mm and a width of 1818 mm is prepared.
(B) A range of 5 cm from the periphery of the wooden base material is defined as the peripheral portion, and the inside thereof is defined as the central portion. As shown by 1 to 35 in FIG. 3, 35 samples of 5 cm × 5 cm are evenly collected, and the moisture content is measured by a total dry method. The all-dry method is a method in which each sample is left in an oven at 105 ° C. for 3 days, and then the moisture content of each sample is measured from the following calculation formula. Before leaving is referred to as before processing, and after leaving is referred to as after processing.

Water content (%) = {(weight before treatment−weight after treatment) / weight after treatment} × 100
(C) The average value of 35 samples is defined as “average moisture content”.
(D) The value obtained by subtracting the average value of the peripheral samples (20 samples) from the average value of the central samples (15 samples) is defined as “moisture content difference”.
(Decorative sheet)
A decorative sheet is laminated on the front surface of the wooden substrate. The decorative sheet preferably has a moisture permeability of 7 g / m ² · 24 hours or less at a temperature of 40 ° C. and a humidity of 90%, more preferably 5 g / m ² · 24 hours or less. The structure of the decorative sheet is not limited, but for example, a decorative sheet having a pattern layer (solid ink layer / pattern ink layer), a transparent resin layer, and a surface protective layer in order on the base sheet is preferable. Hereinafter, this decorative sheet will be exemplarily described.

  The base sheet is 1) paper such as thin paper, fine paper, kraft paper, Japanese paper, titanium paper, resin-impregnated paper, inter-paper reinforced paper, etc. 2) wood fiber, glass fiber, asbestos, polyester fiber, vinylon fiber, rayon Examples thereof include one or two or more laminates of woven or non-woven fabric made of fibers and the like, and 3) sheets of synthetic resin such as polyolefin, polyester, polyacryl, polyamide, polyurethane, and polystyrene.

  As for the thickness of a base material sheet, about 20-300 micrometers is preferable. The substrate sheet may be colored as necessary. Further, the surface may be subjected to surface treatment such as corona discharge treatment, plasma treatment, or ozone treatment.

  The pattern layer is composed of a pattern ink layer and / or a solid ink layer. The pattern layer can be formed by a printing method such as gravure printing, offset printing or silk screen printing. Examples of the pattern of the pattern ink layer include a wood grain pattern, a stone pattern, a cloth pattern, a skin pattern, a geometric pattern, characters, symbols, line drawings, various abstract patterns, and the like. The solid ink layer is obtained by solid printing of colored ink. The pattern layer is composed of one or both of a pattern ink layer and a solid ink layer.

  As the ink used for the pattern layer, as a vehicle, chlorinated polyolefin such as chlorinated polyethylene and chlorinated polypropylene, polyester, polyurethane composed of isocyanate and polyol, polyacryl, polyvinyl acetate, polyvinyl chloride, and vinyl chloride-vinyl acetate are used. A polymer, a cellulose-based resin, a polyamide-based resin, or the like may be used alone or in combination, and a pigment, a solvent, various auxiliary agents, and the like may be added thereto to make an ink. Among these, from the viewpoint of environmental problems, adhesion to the printing surface, and the like, one or a mixture of two or more of polyester, polyurethane composed of isocyanate and polyol, polyacryl, polyamide-based resin, and the like is preferable.

  A transparent resin layer will not be specifically limited if it is a transparent resin layer, For example, it can form suitably with a transparent thermoplastic resin.

  Specifically, soft, semi-rigid or rigid polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer Examples include polymers, ionomers, acrylic esters, and methacrylic esters. Among the above, polyolefin resins such as polypropylene are preferable.

  The transparent resin layer may be colored. In this case, a colorant may be added to the thermoplastic resin. As the colorant, pigments or dyes used in the picture layer can be used.

  For the transparent resin layer, fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, UV absorbers, light stabilizers, radical scavengers, soft components (eg rubber) Various additives such as may be included.

  The surface protective layer (transparent surface protective layer) is provided for imparting surface physical properties such as scratch resistance, abrasion resistance, water resistance and stain resistance required for a decorative sheet. As the resin for forming the surface protective layer, a curable resin such as a thermosetting resin or an ionizing radiation curable resin is preferable. In particular, ionizing radiation curable resins are preferable from the viewpoint of high surface hardness, productivity, and the like.

  Examples of thermosetting resins include unsaturated polyester resins, polyurethane resins (including two-component curable polyurethane), epoxy resins, amino alkyd resins, phenol resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, and melamines. -Urea co-condensation resin, silicon resin, polysiloxane resin and the like.

  A curing agent such as a crosslinking agent and a polymerization initiator, and a polymerization accelerator can be added to the resin. For example, as curing agents, isocyanates, organic sulfonates, etc. can be added to unsaturated polyester resins, polyurethane resins, etc., organic amines, etc. can be added to epoxy resins, peroxides such as methyl ethyl ketone peroxide, azoisobutyl nitrile, etc. A radical initiator can be added to the unsaturated polyester resin.

  Examples of the method for forming the surface protective layer with a thermosetting resin include a method in which a solution of a thermosetting resin is applied by a coating method such as a roll coating method or a gravure coating method and then dried and cured. The coating amount of the solution is about 5 to 30 μm, preferably about 5 to 20 μm in terms of solid content.

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

  Examples of the ionizing radiation include visible light, ultraviolet light (near ultraviolet light, vacuum ultraviolet light, etc.), X-rays, electron beams, ion beams, etc. Among them, ultraviolet light and electron beams are preferable.

  As the ultraviolet light source, a light source such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, or a metal halide lamp can be used. The wavelength of ultraviolet light is about 190 to 380 nm.

  As the electron beam source, various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type can be used. The energy of the electron beam is preferably about 100 to 1000 keV, more preferably about 100 to 300 keV. The irradiation amount of the electron beam is preferably about 2 to 15 Mrad.

  The ionizing radiation curable resin is sufficiently cured when irradiated with an electron beam, but it is preferable to add a photopolymerization initiator (sensitizer) when it is cured by irradiation with ultraviolet rays.

  Examples of the photopolymerization initiator in the case of a resin system having a radically polymerizable unsaturated group include acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether, Michler benzoylbenzoate, Michler ketone, diphenyl sulfide, dibenzyl disulfide. , Diethyl oxide, triphenylbiimidazole, isopropyl-N, N-dimethylaminobenzoate and the like can be used. In the case of a resin system having a cationic polymerizable functional group, for example, at least one kind such as an aromatic diazonium salt, an aromatic sulfonium salt, a metallocene compound, a benzoin sulfonic acid ester, and a freeloxysulfoxonium diallyl iodosyl salt. Can be used.

  Although the addition amount of a photoinitiator is not specifically limited, Generally it is about 0.1-10 weight part with respect to 100 weight part of ionizing radiation curable resins.

  As a method for forming a protective layer with an ionizing radiation curable resin, for example, a solution of an ionizing radiation curable resin may be applied by a coating method such as a gravure coating method or a roll coating method. The coating amount of the solution is generally about 5 to 30 μm, preferably about 5 to 20 μm as a solid content.

  In order to further impart scratch resistance and abrasion resistance to the surface protective layer formed from the ionizing radiation curable resin, an inorganic filler may be blended. 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, Examples include diamond, gold sand and glass fiber.

  The addition amount of the inorganic filler is about 1 to 80 parts by weight with respect to 100 parts by weight of the ionizing radiation curable resin.

  Lamination of each layer is, for example, by forming a pattern layer (solid ink layer, pattern ink layer) on one side of the base sheet by printing in order, and then bonding a known dry lamination such as a two-component curable urethane resin on the pattern layer. A transparent resin layer can be laminated by a dry lamination method, a T-die extrusion method or the like via an agent, and a surface protective layer can be formed.

  An uneven pattern may be formed by embossing from the surface protective layer side. The concavo-convex pattern can be formed by heating press, hairline processing or the like. Examples of the uneven pattern include a conduit groove, a stone plate surface unevenness, a cloth surface texture, a satin finish, a grain, a hairline, and a line groove.

  The decorative sheet may have a synthetic resin layer (so-called backer layer) having a thickness of 100 μm or more in the lowermost layer (layer that adheres to the wooden substrate). In addition, a backer layer means the buffer layer aiming at shock absorption etc. in the decorative material for floors. Examples of the material constituting the backer layer include polypropylene, ethylene-vinyl alcohol copolymer, polymethylene, polymethylpentene, polyethylene terephthalate, and high heat-resistant polyalkylene terephthalate [for example, a part of ethylene glycol is 1,4- Polyethylene terephthalate substituted with cyclohexanedimethanol or diethylene glycol, so-called trade name PET-G (manufactured by Eastman Chemical Company)], polybutylene terephthalate, polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, polycarbonate, poly Examples include arylate, polyimide, polystyrene, polyamide, and ABS. These resins can be used alone or in combination of two or more. The upper limit of the thickness of the backer layer is not limited, but 600 μm is appropriate.

When laminating the decorative sheet on the wooden substrate, a known adhesive can be used. Examples of the adhesive include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ionomer, butadiene / acrylonitrile rubber, neoprene rubber, natural rubber, and the like as active ingredients. Adhesives to be used. Although the thickness of an adhesive bond layer is not limited, About 0.1-50 micrometers is preferable.
(Dampproof film)
The moisture-proof film is provided on the back surface of the wooden substrate. In the present invention, a moisture-proof film having a moisture permeability of 7 g / m ² · 24 hours or less at a temperature of 40 ° C. and a humidity of 90% is used. Among them, the moisture permeability is preferably 5 g / m ² · 24 hours or less.

  The moisture-proof film is not limited as long as the above moisture permeability is satisfied. For example, a synthetic resin film such as an olefin-based thermoplastic resin such as polyethylene or polypropylene, or an ester-based thermoplastic resin such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate is used. Can be used. Among these, those having at least a synthetic resin base material layer and a vapor deposition layer are particularly preferable. Hereinafter, this aspect will be described by way of example.

  Synthetic resin base layers include polyethylene, polypropylene, ethylene-propylene copolymers, ethylene-vinyl alcohol copolymers, olefinic thermoplastic resins such as mixtures thereof; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, Ester thermoplastic resins such as polyethylene naphthalate-isophthalate copolymer, polycarbonate, and polyarylate; Acrylic thermoplastic resins such as polymethyl methacrylate, ethyl polymethacrylate, and polybutyl acrylate; polyimide, polyurethane, Non-halogen thermoplastic resins such as polystyrene and acrylonitrile-butadiene-styrene resin are exemplified.

  The synthetic resin substrate layer may be a sheet stretched in a uniaxial or biaxial direction, or may be unstretched. It is preferable that the synthetic resin base material layer is further laminated with a vapor deposition layer. From the positioning as the base material on which the vapor deposition layer is formed, the mechanical strength is strong and the dimensional stability is biaxial. The sheet | seat extended | stretched is preferable. The appropriate thickness of the synthetic resin base material layer is approximately 9 to 25 μm.

  Examples of the vapor deposition layer include an inorganic vapor deposition layer composed of a metal thin film typified by aluminum, and an inorganic oxide vapor deposition layer composed of an inorganic oxide thin film typified by silicon oxide, magnesium oxide, and aluminum oxide. The vapor deposition layer is formed on the synthetic resin base material layer by a known vapor deposition method such as a vacuum vapor deposition method or a plasma activated chemical reaction vapor deposition method. More preferably, it is an inorganic oxide vapor deposition layer whose vapor deposition layer is transparent.

In order to further improve the gas barrier property of the vapor deposition layer, a surface coat layer may be provided on the vapor deposition layer. Examples of the surface coat layer include polyvinyl alcohol resins. Moreover, the general formula ^{_{R 1 n M (OR 2)}} m ( where in the ^formula, R 1, ^{R 2} represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more M represents an integer of 1 or more, and n + m represents a valence of M), and a polyvinyl alcohol resin and / or an ethylene / vinyl alcohol copolymer. Furthermore, a composition prepared by polycondensation by a sol-gel method in the presence of a sol-gel method catalyst, an acid, water and an organic solvent can be mentioned. Further, by combining polyvinyl alcohol and an ethylene / vinyl alcohol copolymer, gas barrier properties, water resistance, weather resistance and the like are remarkably improved. A silane coupling agent or the like may be added to the composition. A surface coat layer is obtained by applying these resins or compositions on the vapor deposition layer by a known coating method such as a roll coating method or a gravure coating method. The surface coat layer also functions as a protective layer for the vapor deposition layer, and a thickness of about 1 to 10 μm is appropriate.

  The synthetic resin substrate layer and / or the surface coat layer may be subjected to a surface treatment such as a corona treatment, if necessary. By such surface treatment, the adhesive strength with the adjacent layer can be further increased.

  In the present invention, a primer layer may be further provided between the synthetic resin substrate layer and the vapor deposition layer and on one or both sides of the moisture-proof film. Therefore, a suitable aspect of the moisture-proof film is, for example, an aspect of “synthetic resin substrate layer / primer layer / deposition layer / surface coat layer”, and further provided with a primer layer on one or both sides of the moisture-proof film. An aspect may be sufficient.

  These primer layers are provided in order to increase the adhesion between the synthetic resin base material layer and the vapor deposition layer and to increase the adhesion when the moisture-proof film is laminated on another layer.

  Examples of the resin used for such a primer layer include ester resins, urethane resins, acrylic resins, polycarbonate resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral resins, nitrocellulose resins, and the like. These resins can be used alone or in combination. The primer layer can be formed using an appropriate application means such as a roll coating method or a gravure printing method.

  Among these, the primer layer is preferably formed from (i) a copolymer of acrylic resin and urethane resin and (ii) isocyanate. That is, the copolymer of (i) an acrylic resin and a urethane resin is composed of an acrylic polymer component having a hydroxyl group at the terminal (component A), a polyester polyol component having a hydroxyl group at both ends (component B), and a diisocyanate component (component). C) is mixed and reacted to form a prepolymer, and a chain extender (component D) such as diamine is further added to the prepolymer to extend the chain. By this reaction, polyester urethane is formed and an acrylic polymer component is introduced into the molecule to form an acrylic-polyester urethane copolymer having a hydroxyl group at the terminal. The acrylic-polyester urethane copolymer is formed by reacting and curing the terminal hydroxyl group with the isocyanate (ii).

  As the component A, a linear acrylate polymer having a hydroxyl group at the terminal is used. Specifically, linear polymethyl methacrylate (PMMA) having a hydroxyl group at the terminal is preferable because it is excellent in weather resistance (particularly, characteristics against photodegradation) and can be easily copolymerized with urethane. The component A is an acrylic resin component in the copolymer, and those having a molecular weight of 5000 to 7000 (weight average molecular weight) are preferably used because of particularly good weather resistance and adhesiveness. In addition, the component A may be used only having a hydroxyl group at both ends, but a mixture having a conjugated double bond at one end is mixed with the above-mentioned one having a hydroxyl group at both ends. Also good.

  Component B reacts with diisocyanate to form polyester urethane and constitutes a urethane resin component in the copolymer. The component B is a polyester diol having hydroxyl groups at both ends. Examples of the polyester diol include an addition reaction product of a diol compound having an aromatic or spiro ring skeleton and a lactone compound or a derivative thereof, or an epoxy compound, a condensation product of a dibasic acid and a diol, and a cyclic ester compound. Examples thereof include a derived polyester compound. Examples of the diol include short-chain diols such as ethylene glycol, propylene glycol, diethylene glycol, butanediol, hexanediol, and methylpentenediol; and alicyclic short-chain diols such as 1,4-cyclohexanedimethanol. it can. Examples of the dibasic acid include adipic acid, phthalic acid, isophthalic acid, terephthalic acid and the like. Preferred as the polyester polyol is adipic acid using adipic acid or a mixture of adipic acid and terephthalic acid as the acid component, particularly preferably adipic acid, and 3-methylpentenediol and 1,4-cyclohexanedimethanol as the diol component. Polyester.

  In the primer layer, the urethane resin component formed by the reaction of the component B and the component C gives flexibility to the primer layer and contributes to improvement in adhesion. Moreover, the acrylic resin component which consists of an acrylic polymer contributes to a weather resistance and blocking resistance in the said primer layer. In the urethane resin, the molecular weight of the component B may be within a range in which a urethane resin capable of sufficiently exhibiting flexibility in the primer layer is obtained. Adipic acid or a mixture of adipic acid and terephthalic acid, and 3-methylpentanediol In the case of polyester diol composed of 1,4-cyclohexanedimethanol, 500 to 5000 (weight average molecular weight) is preferable.

  As the component C, an aliphatic or alicyclic diisocyanate compound having two isocyanate groups in one molecule is used. Examples of the diisocyanate include tetramethylene diisocyanate, 2,2,4 (2,4,4) -1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and 1,4′-cyclohexyl. A diisocyanate etc. can be mentioned. As the diisocyanate component, isophorone diisocyanate is preferable in terms of physical properties and cost. When the above-mentioned components A to C are reacted, the equivalent ratio of the total hydroxyl group (may be an amino group) of the acrylic polymer, polyester polyol and chain extender described below and the isocyanate group is such that the isocyanate group becomes excessive. To.

  When the above three components A, B and C are reacted at 60 to 120 ° C. for about 2 to 10 hours, the isocyanate group of the diisocyanate reacts with the hydroxyl group at the end of the polyester polyol to form a polyester urethane resin component and an acrylic polymer. A compound in which diisocyanate is added to the terminal hydroxyl group is also mixed, and a prepolymer is formed in a state where excess isocyanate group and hydroxyl group remain. As a chain extender, for example, a diamine such as isophorone diamine or hexamethylene diamine is added to this prepolymer, the isocyanate group is reacted with the chain extender, and the chain is extended so that the acrylic polymer component is contained in the polyester urethane molecule. The (i) acrylic-polyester urethane copolymer introduced and having a hydroxyl group at the terminal can be obtained.

  Addition of isocyanate of (ii) to acrylic-polyester urethane copolymer of (i), coating method and coating liquid adjusted to necessary viscosity in consideration of coating amount after drying, gravure coating method, roll The primer layer may be formed by coating by a known coating method such as a coating method. The isocyanate of (ii) is not limited as long as it can be crosslinked and cured by reacting with the hydroxyl group of the acrylic-polyester urethane copolymer of (i). An aliphatic isocyanate can be used, and an aliphatic isocyanate is particularly desirable from the viewpoint of thermal discoloration prevention and weather resistance. Specifically, tolylene diisocyanate, xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate monomers, dimers, trimers and other multimers, or these And polyisocyanates such as derivatives (adducts) obtained by adding the above isocyanate to a polyol.

As the coating amount after drying of the primer layer is from 1 to 20 g / ^{m 2,} preferably from 1 to 5 g / ^{m 2.} Moreover, the said primer layer is good also as a layer which added additives, such as fillers, such as a silica powder, a light stabilizer, and a coloring agent, as needed.

  When laminating the moisture-proof sheet on the wooden substrate, a known adhesive can be used. Examples of the adhesive include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ionomer, butadiene / acrylonitrile rubber, neoprene rubber, natural rubber, and the like as active ingredients. Adhesives to be used. Although the thickness of an adhesive bond layer is not limited, About 0.1-50 micrometers is preferable.

Since the floor decorative material of the present invention has a moisture-proof film having a moisture permeability of 7 g / m ² · 24 hours or less, the moisture permeability of the back surface of the wooden substrate is suppressed to a low level. Therefore, even when a laminating substitute material with a dimensional change per 1% moisture content change larger than 0.02% is used as a wooden base material and a decorative sheet with low moisture permeability is laminated on the front surface, the wooden base Since the moisture permeability of the front surface and the back surface of the material can be set to the same level, the occurrence of warping and bending of the floor decorative material is sufficiently suppressed. Such a flooring material of the present invention is suitable as a flooring material to be constructed on the floor surface of various buildings and as a flooring material used for floor heating as a special application.

It is a schematic diagram (an example) of the decorative material for floors of the present invention. It is a schematic diagram which shows the curvature and curving of the decorative material for floors. It is a figure which shows the sample used for the measurement of the average moisture content of a wooden base material, and a moisture content difference. It is a schematic diagram of floor heating system test standard II.

1. Cosmetic sheet 2. 2. Adhesive layer Wood base material (Lawan alternative material)
4). 4. Adhesive layer Moisture barrier film

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Example 1
(1) A decorative sheet (0.4 mm) containing a synthetic resin layer is used to make a 5.5 mm thick MDF (woody base material) using an adhesive (BA-10L / BA-11B, 9 g / scale angle) manufactured by Chuo Rika Kogyo. Affixed to the front surface. The dimensional change rate per 1% change in moisture content of the MDF was 0.05%. In addition, the ergonal angle indicates the area of a plane represented by 303 mm in length × 303 mm in width (the same applies hereinafter).
(2) A moisture-proof film was bonded to the back surface of the MDF using an adhesive (BA-10L / BA-11B, 9 g / scale angle) manufactured by Chuo Rika Kogyo. The laminate in this state is referred to as a decorative board.
(3) The decorative board was cut into a size of 313 mm long × 1840 mm wide with a gang saw.
(4) Further, with a tenona processing machine, sag processing, end chamfering processing and V-groove processing (V-groove processing width is 1.5 mm width) were performed.
(5) Further, a paint was applied to the sanitized part, the end chamfered part, and the V-grooved part on the coating line (paint: a paint containing a two-component curable urethane resin).

  Through the above-mentioned process, floor decorative materials were produced.

  The moisture-proof film was produced as follows. That is, a biaxially stretched polyethylene terephthalate film having a thickness of 12 μm was prepared, and a primer layer made of a two-component curable urethane resin was provided on one side. Furthermore, the aluminum vapor deposition layer was provided on the primer layer. The film thus obtained is referred to as “deposited PET film”.

A 0.2 g / m ² (dry state) surface coat layer made of PVA / silicate system is formed on the deposited PET film, and a laminate (synthetic resin substrate layer (PET) / deposition layer / surface coat layer) is formed. Was made. After the corona discharge treatment on both sides of the laminate, 2 g of a two-part curable resin obtained by adding a curing agent (isocyanate) to the main agent (mixture of urethane resin and nitrified cotton-based resin) as a solid content by gravure printing method is 5 g. The adhesive primer layer was formed on both sides by applying at a coating amount of / m ² . As a result, a moisture-proof film (moisture permeability of 1 g / m ² · 24 hours) was obtained.

Example 2
A floor decorative material was prepared in the same manner as in Example 1 except that a 9 mm thick particle board (0.09% dimensional change per 1% moisture content change) was used as the wooden substrate.

Example 3
A flooring decorative material was produced in the same manner as in Example 1 except that 12 mm thick softwood plywood (radiata pine, dimensional change rate per 1% moisture content change was 0.026%) was used as the wooden substrate.

Example 4
A flooring decorative material was prepared in the same manner as in Example 1 except that PE (polyethylene sheet, moisture permeability 7 g / m ² · 24 hours) was used as the moisture-proof film.

Comparative Example 1
A flooring decorative material was prepared in the same manner as in Example 1 except that the moisture-proof film was not used.

Comparative Example 2
A flooring decorative material was produced in the same manner as in Example 2 except that the moisture-proof film was not used.

Comparative Example 3
A flooring decorative material was prepared in the same manner as in Example 3 except that the moisture-proof film was not used.

Comparative Example 4
A floor decorative material was prepared in the same manner as in Example 1 except that a moisture-proof paper (polyethylene as a core layer and laminated on both sides with paper. Moisture permeability of 10 g / m ² · 24 hours) was used as the moisture-proof film. .

Conventional Example 1
A floor decorative material is produced in the same manner as in Example 1 except that a 12 mm thick lauan plywood (a dimensional change rate per 1% moisture content change is 0.016%) is used as a wooden substrate, and a moisture-proof film is not used. did.

Test example 1 (warp and bend in a 40 ° C atmosphere)
The floor decorative materials produced in Examples 1 to 4, Comparative Examples 1 to 4 and Conventional Example 1 are left in a 40 ° C. atmosphere (dry atmosphere) (for 7 days), and the amount of warping and bending of the floor decorative material is left. Was measured.

  A schematic diagram of the amount of warpage and the amount of bending is shown in FIG. The amount of warpage and the amount of bending were measured with a gap gauge. A warp amount of 20 mm / 1840 mm (a warp amount with respect to the horizontal length) or less is acceptable (suitable for practical use). In addition, a bending curve of 0.3 mm / 1840 mm (a bending curve with respect to the horizontal length) or less is acceptable (suitable for practical use). The results are shown in Table 1.

Test example 2 (warp and bend in a 40 ° C., 90% RH atmosphere)
The floor decorative materials produced in the examples and comparative examples were left in an atmosphere of 40 ° C. and 90% RH (for 7 days), and the amount of warping and bending of the floor decorative material was measured in the same manner as in Test Example 1. . The results are shown in Table 1.

As is clear from the results in Table 1 above, the floor decorative material of the present invention provided with a moisture-proof film having a moisture permeability of 7 g / m ² · 24 hours or less is a dimension due to the humidity of the wooden substrate due to the presence of the moisture-proof film. Changes are effectively suppressed. As a result, warping and curving of the floor decorative material are prevented, and the test results of Conventional Example 1 (using Lauan plywood) are closer.

Example 5
(1) Floor decorative sheet (0.16mm thickness, water vapor transmission rate: 3g / m ² · 24 hours) is 12mm thick using Chuo Rika Industries adhesive (BA-10L / BA-11B, 9g / scale angle) The particle board (PB) (woody base material) was bonded to the front surface. The dimensional change rate per 1% moisture content change of the PB was 0.045%, and the average moisture content was 6.5% by weight.
(2) Moisture-proof film (PET film + vapor deposition layer, water vapor transmission rate: 3g / m ² · 24 hours) using adhesive (BA-10L / BA-11B, 9g / scale angle) made by Chuo Rika Kogyo on the back of PB ). The laminate in this state is referred to as a decorative board.
(3) The decorative board was cut into a size of 313 mm long × 1840 mm wide with a gang saw.
(4) Further, with a tenona processing machine, sag processing, end chamfering processing and V-groove processing (V-groove processing width is 1.5 mm width) were performed.
(5) Further, a paint was applied to the sanitized part, the end chamfered part, and the V-grooved part on the coating line (paint: a paint containing a two-component curable urethane resin).

  A flooring decorative material was produced through the above steps. In addition, between each process, the decorative board was wrapped in PP film (30 micrometers thickness, water vapor transmission rate 15g), and the moisture-proof process was carried out.

Example 6
A flooring decorative material was produced in the same manner as in Example 5 except that the moisture-proof treatment using the PP film was not performed between the steps. Thereby, the moisture content of the peripheral part of a wooden base material was made higher than the center part.

Example 7
A flooring decorative material was prepared in the same manner as in Example 5 except that a PB base material having a moisture content of 2% higher than that of the peripheral part was used in the central part of the wooden base material.

Example 8
A flooring decorative material was prepared in the same manner as in Example 5 except that a softwood plywood having a moisture content of 1.7% higher than that of the peripheral part was used in the central part of the wooden substrate.

Comparative Example 5
A flooring decorative material was produced in the same manner as in Example 6 except that PB having an average moisture content of 5.5% was used as the wooden substrate.

Comparative Example 6
A flooring decorative material was produced in the same manner as in Example 6 except that after tenon processing, the sample was left for one week without being subjected to moisture-proof treatment.

Comparative Example 7
A flooring decorative material was produced in the same manner as in Example 5 except that a PB base material having a moisture content of 2.5% higher than that of the peripheral part was used.

Comparative Example 8
A floor decorative material was prepared in the same manner as in Example 5 except that the average moisture content was adjusted to 10.5% and a PB base material having a moisture content at the center of the wood of 1.3% lower than the peripheral portion was used.

Test Example 3 (Evaluation of bendability and construction suitability after cutting a flooring decorative material)
<Evaluation of amount of curving after cutting>
The floor decorative material (length 313 mm × width 1840 mm) prepared in Examples 5 to 8 and Comparative Examples 5 to 8 was cut into about half (length 150 mm × width 1840 mm) at the center.

  The cut flooring was measured for the amount of lateral bending using a straight ruler and a gap gauge. The measurement was performed within 30 minutes after cutting. As for the amount of bending, the state where each sane side (male sane, female sane) is convex is defined as + display.

It should be noted that the amount of bending after cutting is allowable in the range of “−1.0 mm / horizontal 1840 mm to +0.7 mm / horizontal 1840 mm”.
<Evaluation of construction aptitude>
The floor decorative materials (313 mm long × 1840 mm wide) produced in Examples 5 to 8 and Comparative Examples 5 to 8 were first applied in the same size. Then, the floor decorative material cut into about a half (150 mm x 1840 mm) at the center was applied within 30 minutes after cutting, and the suitability after cutting was evaluated. The evaluation criteria were as follows.

  ○: As with the case before cutting, construction can be performed without any problem, and no gap is observed at the joint.

  (Triangle | delta): If it takes an effort, it can somehow be constructed, and a clearance gap is not recognized by a joint.

  X: Construction is difficult, and a gap exceeding 0.3 mm is observed at the joint.

Test example 4 (floor heating system test)
The floor decorative materials (313 mm long × 1840 mm wide) produced in Examples 5 to 8 and Comparative Examples 5 to 8 were subjected to a floor heating system test. The floor heating system is generally not installed at the corners of the room (by the walls or around the columns), but at the center of the room excluding the corners. Therefore, in Test Example 4, a floor heating system test was performed on a floor decorative material (length 313 mm × width 1840 mm).

  More specifically, a floor heating system test shown in FIG. 4 (finishing material / base material “II. Durability Performance Thermal Durability Test” 80 ° C. hot water × 1100 is used. Continuous hot water and gas company standard system).

About the test piece after the test,
(1) Pass if the gap displacement of the steel assembling part (fitting part) is 0.5 mm or less (2) Pass if the step displacement of the sash assembling part (fitting part) is 0.5 mm or less (3) Horizontal If the amount of warpage (= width warpage) in the direction (1840 mm) was less than 1 mm, the evaluation was made according to the acceptance criteria. Those that passed all were marked as ◯, and those that did not satisfy even one were marked as x.

  The evaluation and test results are shown in Table 2 below.

As is apparent from the results in Table 2 above, the average moisture content is particularly 6 to 10% by weight, and the moisture content in the central part is in the range of -1% to + 2% compared with the moisture content in the peripheral part. By using the woody base material, it is possible to effectively suppress the bending after cutting. Moreover, the floor decorative material of the present invention can be put to practical use as a floor heating floor material when the moisture permeability of the moisture-proof film is 7 g / m ² · 24 hours or less.

Claims (8)

A decorative sheet for flooring in which a decorative sheet is laminated on the front surface of the wooden substrate, and a moisture-proof film is laminated on the back surface of the wooden substrate,
(1) The wooden base material has a dimensional change per 1% moisture content change larger than 0.02%, (2) the moisture-proof film has a moisture permeability of 7 g / m ² · 24 hours or less,
(3) The decorative sheet has a moisture permeability of 7 g / m ² · 24 hours or less,
(4) The wooden substrate has an average moisture content of 6 to 10% by weight.
A decorative material for floors.   The wood base material is at least one selected from the group consisting of medium density wood fiber board (MDF), high density wood fiber board (HDF), particle board (PB), softwood plywood, and early-wood plywood. Item 10. The floor decorative material according to Item 1.   The said moisture-proof film is a decorative material for floors of Claim 1 or 2 which has a synthetic resin base material layer and a vapor deposition layer at least.   The floor moisture-proof material according to claim 3, wherein the moisture-proof film has a primer layer between the synthetic resin substrate layer and the vapor deposition layer.   The said moisture-proof film is the decorative material for floors of Claim 3 which consists of the said synthetic resin base material layer / primer layer / the said vapor deposition layer / surface coat layer.   The floor decorative material according to any one of claims 3 to 5, further comprising a primer layer on one or both surfaces of the moisture-proof film.   The said decorative sheet and the said moisture-proof film are the decorative materials for floors in any one of Claims 1-6 laminated | stacked on the said wooden base material with the adhesive agent.   The flooring decorative material according to any one of claims 1 to 7, which is a flooring for floor heating.