JP5909963B2 - Floor decorative material - Google Patents

Description

  The present invention relates to a flooring decorative material having excellent scratch resistance and impact resistance even when a thin-layer single-sided decorative sheet is used.

Conventionally, as a decorative material for a floor of a house, a material in which a decorative sheet having a design of natural wood is pasted on the front surface of a wooden base material made of various plywoods or wood fiber boards is known (Patent Document 1). etc). Such a decorative sheet for floor is required to have excellent scratch resistance in addition to the decorative performance. As a decorative sheet for floors, for example, it is known that a transparent resin layer and further a surface protective layer are provided in order on the pattern layer provided on the base material sheet in order to express scratch resistance characteristics. .
In the production of a floor decorative sheet, if the number of manufacturing steps increases, naturally the production cost and loss increase accordingly, and therefore the number of manufacturing steps is required to be reduced.

  On the other hand, in the conventional decorative material for floors, when the paint is applied to the actual machining cut portion and the groove cutting portion, the paint is difficult to adhere to the cut end surface of the decorative sheet, so that a linear shape along the cut surface of the decorative sheet cutting portion is obtained. There is a problem that the appearance quality is deteriorated. Therefore, in order to prevent the above disadvantage from occurring, it is desired to make the decorative sheet for floors thinner.

  As a floor decorative sheet with a reduced number of manufacturing steps and a thin film, for example, a single-layer back-printed floor decorative sheet can be considered, but in order to conceal the base material laminated on the back surface of the decorative sheet. Therefore, it is necessary to use an ink containing a large amount of pigment. Use of such an ink deteriorates the adhesion between the decorative sheet and the substrate, and as a result, the decorative sheet is easily peeled off (Patent Document 2 and the like).

  On the other hand, as a floor decorative sheet with a reduced number of manufacturing steps and a thin film, for example, a floor decorative sheet with a single-layer surface printing specification can be considered, but the decorative sheet is easy to take a picture by scratching with a high load. The scratch resistance is greatly reduced. This problem is caused because the load is not dispersed because the decorative sheet is a thin film. And in order to eliminate this problem, when the said decorative sheet is laminated | stacked on the wooden base material with low surface specific gravity, although scratch resistance improves, impact resistance deteriorates.

  Therefore, in consideration of the balance between the wooden base material and the decorative sheet, it is hoped that a floor decorative material with excellent scratch resistance and impact resistance will be developed even when a thin single-layer surface printed decorative sheet is used. It is rare.

JP 2006-97321 A Japanese Patent Laid-Open No. 2001-181985

  An object of the present invention is to provide a flooring decorative material excellent in scratch resistance and impact resistance even when a thin-layer single-sided decorative sheet is used.

  As a result of intensive studies, the inventor has found that the above object can be achieved by setting the physical properties of the surface protective layer, the base sheet, and the wooden base material, which are the outermost layers of the decorative sheet, to a specific range. The invention has been completed.

That is, the present invention relates to the following floor decorative material.
1. A decorative floor material in which a decorative sheet is laminated on a wooden substrate,
(1) The wood base material is composed of one wood layer or two or more wood layers, and the surface density of the wood layer in contact with the decorative sheet is 0.7 g / cm ³ or more,
(2) The decorative sheet has a base sheet, a pattern layer and a surface protective layer in order,
(3) The tensile modulus of the base sheet is 1000 MPa or more,
(4) The surface protective layer has a thickness of 15 to 60 μm,
(5) The Martens hardness of the surface protective layer is 90 to 240 N / mm ² .
Flooring cosmetics.
2. Item 2. The floor decorative material according to Item 1, wherein the surface protective layer contains an ionizing radiation curable resin.
3. Item 3. The floor decorative material according to Item 1 or 2, wherein the surface protective layer contains an electron beam curable resin.
4). Item 4. The floor decorative material according to any one of Items 1 to 3, wherein the base sheet has a tensile elastic modulus of 1200 MPa or more.
5. Item 5. The floor decorative material according to any one of Items 1 to 4, wherein the surface protective layer has a thickness of 20 to 40 µm.
6). Item 6. The floor decorative material according to any one of Items 1 to 5, wherein the base sheet has a thickness of 90 µm or less.

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

Floor decorative material of the present invention The floor decorative material of the present invention is a floor decorative material in which a decorative sheet is laminated on a wooden substrate,
(1) The wood base material is composed of one wood layer or two or more wood layers, and the surface density of the wood layer in contact with the decorative sheet is 0.7 g / cm ³ or more,
(2) The decorative sheet has a base sheet, a pattern layer and a surface protective layer in order,
(3) The tensile modulus of the base sheet is 1000 MPa or more,
(4) The surface protective layer has a thickness of 15 to 60 μm,
(5) The Martens hardness of the surface protective layer is 90 to 240 N / mm ² .
It is characterized by that. The floor decorative material of the present invention having the above-described characteristics is particularly that the surface density of the wood layer in contact with the decorative sheet of the wooden substrate is 0.7 g / cm ³ or more, and the tensile modulus of the substrate sheet is A single-layer surface-printed decorative sheet having a thickness of 1000 MPa or more, a thickness of the surface protective layer of 15 to 60 μm, and a Martens hardness of the surface protective layer of 90 to 240 N / mm ^2. Even when is used, it is excellent in scratch resistance and impact resistance.

Hereinafter, each structure of the decorative material for floors of this invention is demonstrated.
≪Wooden base material≫
The wood substrate used in the present invention is composed of one wood layer or two or more wood layers. That is, in the case of two or more layers, two or more wood layers are laminated. Each wood layer includes wood veneer, wood plywood, wood fiber board, particle board (PB), etc. In the case of wood veneer and wood plywood, tree species such as cedar, firewood, lawan, teak, eucalyptus, etc. is there. Examples of the wood fiber board include a medium density wood fiber board (MDF) and a high density wood fiber board (HDF). Among these, at least one selected from the group consisting of MDF, HDF, and particle board is preferable from the viewpoint of not projecting irregularities on the surface of the decorative sheet laminated on the wooden substrate and not impairing the appearance quality of the floor. .

  Strictly speaking, the wood plywood is obtained by bonding a plurality of thin plates, but in this specification, the wood plywood itself means one wood layer. A woody base material can be used combining 1 type (s) or 2 or more types of materials.

In the present invention, a wood layer having a surface density of 0.7 g / cm ³ or more is used as the wood layer in contact with the decorative sheet. That is, the surface density means the physical property of the wood layer when it is composed of one layer of wood, and means the physical property of the wood layer of the outermost layer (decorative sheet side) when it is composed of two or more layers. . Note that the above description of “wood layer in contact with the decorative sheet” means a wooden layer closest to the decorative sheet, and in fact, indirectly through an adhesive layer between the wooden layer and the decorative sheet. It also includes cases where they are in contact with each other.

The surface density of the wood layer in contact with the decorative sheet (hereinafter also referred to as “the wood layer”) may be 0.7 g / cm ³ or more. The surface density, especially in the case of wood fiberboard and particle board, is derived from the manufacturing method, considering that the density near the surface of the wood layer is larger than that near the center. It means the maximum density at. In addition, when the surface density of the said wood layer is less than 0.7 g / cm < ³ >, there exists a possibility that the outstanding impact resistance may not be obtained.

The surface density in this specification is a value measured by the following procedure with reference to FIG.
(1) Irradiate a certain amount of γ-rays in the plane direction (x direction) of the wood layer. Multiple points are irradiated continuously so that there are 25 points for a thickness of 1 mm (that is, 300 points when the thickness of the wood layer is 12 mm as shown in FIG. 2).
(2) Measure and record the radiation dose of gamma rays that have passed through the wood layer.
(3) Calculate the amount of transmission loss of γ rays by subtracting the amount of radiation after transmission in (2) from the amount of γ rays irradiated to the wood layer.
(4) The transmission loss amount per unit length is calculated by dividing the transmission loss amount of γ rays calculated in (3) above by the length (L) in the irradiation direction (x direction).
(5) Perform steps (1) to (4) on a resin plate (standard sample: density 1 g / cm ³ ) whose density has already been specified. Is calculated.
(6) Calculate the density of the wood layer by comparing the transmission loss per unit length of the wood layer with the transmission loss per unit length of the standard sample.
(7) The maximum value of the calculated multi-point density (300 points when the thickness of the wood layer is 12 mm as shown in FIG. 2) is defined as the surface density.

  When the wood substrate is composed of two or more wood layers, the density of the remaining layers (lower layers) excluding the outermost layer is not particularly limited.

  The thickness of the wooden substrate is not particularly limited, but is preferably about 2 to 15 mm, and more preferably about 6 to 12 mm.

≪Makeup sheet≫
A decorative sheet is laminated on the wooden substrate. The decorative sheet is not particularly limited as long as it has a base sheet, a pattern layer and a surface protective layer in this order. Hereinafter, this decorative sheet will be exemplarily described.

  The base material sheet used in the present invention has a tensile elastic modulus of 1000 MPa or more. A preferable tensile elastic modulus is 1200 MPa or more, and more preferably 1200 to 6000 MPa. In addition, although an upper limit is not limited, when it is 6000 Mpa or more, it may be unable to roll, or when rolled, a curl may generate | occur | produce strongly. When the tensile modulus is less than 1000 MPa, there is a possibility that excellent scratch resistance cannot be obtained.

  The tensile elastic modulus is a value measured according to JIS K6734. Specifically, using a tensile tester (Tensilon universal tester RTC-1250A), both ends (A and B in FIG. 3) of the test sample (base sheet) punched into the shape shown in FIG. This is a value obtained by measuring the tensile elastic modulus (MPa) when pulled at a speed of / min.

  As a base material sheet, what was formed, for example with the thermoplastic resin is suitable. Specifically, polyvinyl chloride (PVC), polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene (PP), polycarbonate, polyethylene naphthalate, ethylene-vinyl acetate copolymer (EVA), ethylene- (meth) Acrylic acid copolymers, ethylene- (meth) acrylic acid ester copolymers, ionomers, polyacrylic acid esters, polymethacrylic acid esters and the like can be mentioned. Among these resins, the base sheet can be appropriately selected or used in combination of two or more resins so that the tensile elastic modulus of the base sheet is within the above range.

  The base material sheet may be colored. In this case, a coloring material (pigment or dye) can be added to the above thermoplastic resin for coloring. As the colorant, for example, inorganic pigments such as titanium dioxide, carbon black and iron oxide, organic pigments such as phthalocyanine blue, and various dyes can be used. These can be selected from one or more known or commercially available ones. Further, the addition amount of the colorant may be appropriately set according to the desired color tone. The substrate sheet may be transparent, but a colored substrate sheet is preferable in consideration of concealing the wooden substrate to be laminated.

  The base sheet contains various additives such as fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, antioxidants, UV absorbers, and light stabilizers as necessary. It may be.

  Although the thickness of a base material sheet is not specifically limited, 100 micrometers or less are preferable from a viewpoint of restraining the adhesion amount of a coating material in the actual process of a decorative sheet cross section, restraining cost (resource saving), etc. More preferably, it is 40-80 micrometers. Although a lower limit is not limited, when the concealability to the wooden base material to bond is considered, it is about 40 micrometers.

  Moreover, surface treatments such as corona discharge treatment, plasma treatment, and ozone treatment may be applied to the surface of the base sheet.

  The pattern layer (pattern 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 pattern-like (for example, conduit pattern) low-gloss printing layer may be provided on the pattern layer as necessary. The area provided with the low gloss printing layer is less glossy than the other areas, and the design is recognized as if the area is a concave portion by the optical illusion.

  As the ink used for the low gloss printing layer, one or a mixture of two or more polyvinyl acetal resins, urethane resins, etc. is used as a vehicle, and inks are added by adding pigments, solvents, various auxiliary agents, etc. Can be used.

The surface protective layer is the outermost layer. In the present invention, the thickness of the surface protective layer is 15 to 60 μm, and the Martens hardness is 90 to 240 N / mm ² . The thickness of the surface protective layer is preferably 20 μm or more from the viewpoint of improving scratch resistance, and preferably 40 μm or less from the viewpoint of impact resistance. If the thickness is less than 15 μm, excellent scratch resistance may not be obtained, and if it is thicker than 60 μm, excellent impact resistance may not be obtained. Moreover, Martens hardness is preferably 140 N / mm ² or more in view of scratch resistance, preferably 210N / mm ² or less from the viewpoint of impact resistance. When it is less than 90 N / mm ² , excellent scratch resistance may not be obtained, and when it is greater than 240 N / mm, excellent impact resistance may not be obtained.

  The Martens hardness of the surface protective layer can be appropriately adjusted by 1) mixing two or more kinds of resins having different hardnesses, or 2) mixing an elastomer with the resin. Further, when using an ionizing radiation curable resin, which will be described later, for the surface protective layer, it is possible to change the number of polymerizable functional groups contained in one molecule or to mix resins having different functional group numbers. The hardness can be adjusted to a desired value.

In addition, the Martens hardness in this specification is a value measured using a surface film physical property tester (PICODENTOR HM-500, manufactured by Fisher Instruments Co., Ltd.), and a specific measurement method is as follows. is there. In this measurement method, using the diamond indenter (Vickers indenter) shown in FIG. 1 (a), the diamond indenter is pushed into the measurement sample as shown in FIG. 1 (b), and the diagonal line of the pyramidal depression formed on the surface is obtained. The surface area A (mm ² ) is calculated from the length of and the hardness is obtained by dividing the test load F (N). As shown in FIG. 1 (c), the indentation condition was that a load of 0 to 5 mN was first applied for 10 seconds, then held at a load of 5 mN for 5 seconds, and finally 5 Unloading to ~ 0mN is performed in 10 seconds. And the hardness calculated | required by F / A based on the surface area A and the test load F is the said Martens hardness. In addition, in this specification, in order to avoid the influence of the hardness of layers other than a surface protective layer, the Martens hardness of the cross section of the surface protective layer was measured. In this case, the decorative sheet is embedded with a resin (cold-curing type epoxy two-component curable resin), allowed to stand at room temperature for 24 hours or more and cured, and then the cured embedded sample is mechanically polished to provide a surface protective layer. The cross section was exposed, and the Martens hardness of the cross section was measured by pushing a diamond indenter into the cross section (at a position avoiding the fine particles such as inorganic filler in the surface protective layer).

  The resin for forming the surface protective layer can be appropriately selected within a range in which a predetermined Martens hardness can be obtained, but a curable type such as a thermosetting resin or an ionizing radiation curable resin (for example, an electron beam curable resin). Resins are preferred. 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 15 to 60 μm, preferably about 20 to 40 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 cross-linked 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 or electron beams are desirable.

  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.

  Photopolymerization initiators in the case of resin systems having radically polymerizable unsaturated groups include, for example, 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 mass parts with respect to 100 mass parts 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 15 to 60 μm, preferably about 20 to 40 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, Diamond, gold sand, glass fiber, etc. are mentioned.

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

  Lamination of each layer constituting the decorative sheet can be performed, for example, by a method in which a pattern layer (solid ink layer, pattern ink layer) is sequentially formed on one surface of the base sheet by printing, and then a surface protective layer is formed.

  An uneven pattern may be formed by embossing from the surface protective layer side, but it is preferable not to form the uneven shape because it may reduce the scratch resistance.

  When laminating the decorative sheet on the wood 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.

≪Others≫
You may provide a moisture-proof film in the back surface of a wooden base material. The moisture-proof film 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%, and more preferably has a moisture permeability of 5 g / m ² · 24 hours or less.

  The moisture-proof film is not particularly limited, and 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 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 an acrylic resin and a urethane resin and (ii) an 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 the terminal hydroxyl group with the isocyanate (ii) and curing.

  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 in which a conjugated double bond remains at one end is mixed with the one having a hydroxyl group at both ends. Also good.

  The 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, coating solution 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) may be any isocyanate that 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 film 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.

  The floor decorative material of the present invention is suitable as a floor decorative material to be applied to floor surfaces of various buildings and as a floor decorative material used for floor heating as a special application.

In the floor decorative material of the present invention, in particular, the surface density of the wooden layer in contact with the decorative sheet of the wooden base material is 0.7 g / cm ³ or more, and the tensile modulus of the base sheet is 1000 MPa or more. Furthermore, when the thickness of the surface protective layer is 15 to 60 μm and the Martens hardness of the surface protective layer is 90 to 240 N / mm ² , a thin-layer single-layer surface printed decorative sheet is used. Is excellent in scratch resistance and impact resistance.

It is a figure which shows the diamond indenter (a) used for the measurement of the Martens hardness in this specification, the schematic diagram (b) of pushing operation, and an example (c) of pushing load and displacement. It is a figure which shows an example (b) of the concept of the irradiation direction of a gamma ray with respect to the wood layer used for calculation of the surface density in this specification, a score (a), and a surface density. FIG. 2 is an example when a wood layer having a thickness of 12 mm is used. Since the thickness is 12 mm, γ rays are irradiated at 300 points in (a). Moreover, (b) is the figure which represented the density measured by the said 300 points | pieces by the horizontal axis (thickness direction z) and the vertical axis | shaft (density g / cm < ³ >). It is a schematic diagram (top view) which shows the shape of a sample in the case of measuring the tensile elasticity modulus of a sample. In the figure, R60 indicates the degree of curvature.

  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
A primer layer (back surface primer layer) was provided on the back surface of a colored homopropylene film (base material sheet) having a tensile elastic modulus of 1200 MPa and a thickness of 80 μm. Next, a picture pattern layer is formed on the front surface of the base sheet by printing, and an ionizing radiation curable resin mainly composed of the following composition is applied to the picture pattern layer by a roll coating method to a thickness of 30 μm, Next, a surface protective layer was formed by irradiating and curing an electron beam under the conditions of an acceleration voltage of 175 keV and 5 Mrad using an electron beam irradiation apparatus in an environment with an oxygen concentration of 200 ppm or less, and a decorative sheet was produced. The Martens hardness in the cross-sectional direction of the surface protective layer was 140 N / mm ² (average value of 10 points of measurement).
70 parts by weight of bifunctional urethane acrylate oligomer (weight average molecular weight: 1500, Tg (glass transition temperature): 25 ° C., polyol component is polyester diol)
-Hexafunctional aliphatic urethane acrylate oligomer 30 parts by mass (weight average molecular weight: 1500, Tg (glass transition temperature): 200 ° C. or higher, manufactured by Kyoeisha Chemical Co., Ltd.)
Matting agent (11 μm silica) 14 parts by mass The decorative sheet prepared above is bonded to a particle board (woody base material) having a surface density of 1.0 g / cm ³ and a thickness of 12 mm via an adhesive. The floor decorative material was produced by bonding.

Examples 2-14 and Comparative Examples 1-6
By adjusting the content of each oligomer of Example 1 or changing the configuration of each layer, floor decorative materials as shown in Tables 1 and 2 were produced. In the table, PP means polypropylene, PET means polyethylene terephthalate, PB means particle board, and MDF means medium density wood fiber board.

Test example 1 (coin scratch test)
Two coins (10-yen coins) were set so as to contact at an angle of 45 ° (two-point support), and the testing machine was moved on the decorative material for each floor. The load (weight) of the testing machine was 3 kg, 5 kg, or 7 kg, and the presence or absence of pattern removal on the floor decorative material surface when the testing machine was dragged in the horizontal direction was evaluated. In addition, the pattern taken refers to a state in which a scratch reaches the pattern layer and the pattern appears to have disappeared visually. The evaluation criteria are as follows, and Δ or higher is acceptable.
◎: No significant pattern removal occurs even at 7 kg load ○: Significant pattern removal occurs at 7 kg load, no significant pattern removal occurs at 5 kg load △: Significant pattern removal occurs at 7 kg load 3 kg load In, no significant pattern removal occurs ×: Significant pattern removal occurs at 3 kg load
Test example 2 (steel ball drop test)
A steel ball having a mass of 286 g and a diameter of 4 cm was dropped from a height of 100 cm onto a test piece, and the presence or absence of surface cracks was evaluated. The evaluation criteria are as follows.
○: Surface crack does not occur ×: Surface crack occurs
Test example 3 (steel ball drop test)
A steel ball having a mass of 286 g and a diameter of 4 cm was dropped from a height of 100 cm onto a test piece, and the amount of dents was evaluated. In addition, about the test example 3, it carried out only with respect to Examples 12 to 14 and Comparative Example 6. The evaluation criteria are as follows.
○: Depression amount is less than 300 μm ×: Depression amount is 300 μm or more Tables 1 and 2 show the evaluation results.

Claims (6)

A decorative floor material in which a decorative sheet is laminated on a wooden substrate,
(1) The wood base material is composed of one wood layer or two or more wood layers, and the surface density of the wood layer in contact with the decorative sheet is 0.7 g / cm ³ or more,
(2) The decorative sheet has a base sheet, a pattern layer and a surface protective layer in order,
(3) The tensile modulus of the base sheet is 1000 MPa or more,
(4) The surface protective layer has a thickness of 15 to 60 μm,
(5) The Martens hardness of the surface protective layer is 90 to 240 N / mm ² .
Flooring cosmetics.   The floor covering material according to claim 1, wherein the surface protective layer contains an ionizing radiation curable resin.   The floor decorative material according to claim 1 or 2, wherein the surface protective layer contains an electron beam curable resin.   The flooring decorative material according to any one of claims 1 to 3, wherein the base sheet has a tensile elastic modulus of 1200 MPa or more.   The floor decorative material according to any one of claims 1 to 4, wherein the surface protective layer has a thickness of 20 to 40 µm. The floor decorative material according to any one of claims 1 to 5, wherein the base sheet has a thickness of 90 µm or less.

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