JP6346707B1 - Cosmetic material - Google Patents

Abstract

The present invention provides a decorative material having excellent design properties, which has excellent impact resistance, and is less visible from the surface of a design layer of warpage and appearance defects on the surface of a plywood. A plywood having a first layer and a second layer in order from the top, and a decorative material having a design layer on the first layer, wherein (1) the first layer and the second layer are (2) the thickness of the first layer is less than 1.0 mm, (3) the specific gravity of the second layer is greater than the specific gravity of the first layer, and (4) the design layer is A decorative material characterized in that it is a synthetic resin decorative sheet having a total thickness of 0.2 mm or more and 0.7 mm or less. [Selection figure] None

Description

  The present invention relates to a decorative material.

  Conventionally, a wooden layer of HDF or a lauan plywood laminated with a lauan material is used as a wooden base material for a decorative material such as a flooring decorative material. Note that plywood is a thin plate of wood called a single plate (tanban) cut with a rotary race, slicer, etc., and the fiber directions of the single plate are substantially perpendicular to each other, and a plurality of single plates are bonded. Laminated wood board.

  Lauan lumber is limited in logging due to resource depletion. For this reason, the amount of Lauan wood in the market has been drastically reduced, and it is being considered to use plywood other than Lauan wood as much as possible as a wooden base material (to remove Lauan wood) to reduce the amount of Lauan wood used. As such plywood, plywood using conifer plywood or fast-growing trees is used.

  However, the delawn material has insufficient hardness because the hardness is not sufficient, and the appearance defect of the surface of the plywood using the delaminated material is a defect in the decorative material in which the design layer is laminated on the surface of the plywood. There is a problem of being visually recognized.

  As a plywood that has solved the above-mentioned problems, it has been proposed to use a plywood in which a wooden base material (MDF, HDF, etc.) having a hard surface and a smooth surface is bonded to the surface of the delaminated material as a flooring material. (For example, refer to Patent Documents 1 and 2).

  However, MDF and HDF have a large dimensional change rate as compared with the delaminated material, so that a decorative material using these plywoods has a problem of warping.

  Further, instead of pasting a wooden base material having a smooth surface, a flooring decorative material using a decorative sheet in which a hard resin layer is provided on the back surface of the decorative sheet to form a thick film has been proposed (for example, Patent Documents). 3).

  The floor decorative material described in Patent Document 3 has room for study on improvement of impact resistance and suppression of warpage. In order to give more sufficient impact resistance, it is necessary to increase the thickness of the decorative sheet. The shrinkage stress due to the linear expansion difference between the decorative sheet and the wood plywood generated when the temperature changes is applied to the decorative material. Warping occurs, a load is generated between the decorative sheet and the wooden plywood, and in some cases, a part of the wooden plywood is cracked, and the appearance defects are visually recognized on the surface of the decorative material, resulting in a decrease in design. There are things to do.

  Accordingly, it is desired to develop a cosmetic material having excellent design properties that is excellent in impact resistance, and that is less visible from the surface of the design layer with respect to warpage and appearance defects on the surface of the plywood.

JP 2004-107905 A JP 2012-214981 A JP 2013-083142 A

  An object of the present invention is to provide a decorative material having excellent design properties, which is excellent in impact resistance, in which the warp and the visual defect of the appearance defects on the surface of the plywood are suppressed from the surface of the design layer.

  As a result of intensive studies, the present inventors have found that the first layer and the second layer are woody in the decorative material having the design layer on the first layer of the plywood having the first layer and the second layer in order from the top. The first layer has a thickness of less than 1.0 mm, the second layer has a specific gravity greater than that of the first layer, and the design layer has a thickness of 0.2 to 0.7 mm. The present invention has been completed by finding that the above-described object can be achieved by using a makeup sheet.

That is, the present invention relates to the following cosmetic materials.
1. A decorative material having a design layer on the first layer of a plywood having a first layer and a second layer in order from the top,
(1) The first layer and the second layer are made of wood.
(2) The thickness of the first layer is less than 1.0 mm,
(3) The specific gravity of the second layer is greater than the specific gravity of the first layer,
(4) The design layer is a synthetic resin decorative sheet having a total thickness of 0.2 to 0.7 mm.
A cosmetic material characterized by that.
2. Item 2. The cosmetic material according to Item 1, wherein the synthetic resin decorative sheet has a thickness of 0.3 mm to 0.6 mm.
3. Item 2. The decorative material according to Item 1, wherein the synthetic resin decorative sheet has a synthetic resin backer layer on the plywood side.
4). Item 4. The cosmetic material according to Item 3, wherein the synthetic resin backer layer has a Martens hardness of 50 to 300 N / mm ² .
5. Item 2. The cosmetic material according to Item 1, wherein the outermost layer of the synthetic resin decorative sheet is an ionizing radiation curable resin layer.
6). Item 6. The decorative material according to Item 5, wherein the synthetic resin decorative sheet has the ionizing radiation curable resin layer as an electron beam curable resin layer.
7). Item 2. The cosmetic material according to Item 1, wherein the first layer is a poplar veneer and the second layer is a eucalyptus veneer.
8). Item 2. The cosmetic material according to Item 1, wherein the first layer is a Chinese poplar veneer.
9. Item 2. The cosmetic material according to Item 1, wherein the first layer is a hardwood veneer.
10. Item 2. The cosmetic material according to Item 1, wherein the specific gravity of the first layer is less than 0.50, and the specific gravity of the second layer is 0.50 or more.
11. Item 2. The cosmetic material according to Item 1, wherein the thickness of the first layer is 0.6 mm or more and 0.8 mm or less. 12 Item 2. The cosmetic material according to Item 1, wherein the second layer has nodes on at least a part of the surface on the first layer side, and the nodes of the first layer are fewer than the nodes of the second layer. .
13. Item 2. The decorative material according to Item 1, wherein the number of layers of the plywood is five or seven.
14 Item 2. The cosmetic material according to Item 1, which is a flooring cosmetic material.

  The decorative material of the present invention is excellent in impact resistance, the visual recognition from the surface of the design layer of the warp and the appearance defect of the surface of the plywood is suppressed, and the design material is excellent.

It is a schematic diagram which shows an example of the laminated constitution of the plywood which comprises the decorative material of this invention. It is a schematic diagram which shows an example of the laminated constitution of the plywood which comprises the decorative material of this invention. It is a 2nd page figure which shows an example of the decorative material of this invention. It is a schematic diagram which shows an example of the synthetic resin-made decorative sheet which comprises the decorative material of this invention. It is a figure which shows the diamond indenter (a) used for measurement of Martens hardness, the schematic diagram (b) of pushing operation, and an example (c) of pushing load and displacement. It is a schematic diagram which shows an example of the measuring method of the amount of dents in impact resistance test evaluation. It is a schematic diagram which shows an example of the curvature amount d in curvature amount evaluation. It is a schematic diagram which shows an example of the cohesive crack of the 1st layer in external appearance evaluation. It is a schematic diagram which shows an example of the measuring method of specific gravity. (A) is the figure which cut out the plywood into the fixed magnitude | size, (b) is the figure which made thin the thickness of the layer which is a measuring object. It is a schematic diagram which shows an example of the measuring method of specific gravity. (A) is a diagram in which a plywood is cut out to a certain size, (b) is a diagram in which a layer laminated on the layer to be measured is scraped in the thickness direction from the surface, and all are removed, and (c) is a measurement. It is the figure which made thickness of the layer which is object thin.

  Hereinafter, the decorative material of the present invention will be described in detail. In the decorative material of the present invention, the uppermost layer of the design layer (for example, the surface protective layer when the surface protective layer is formed) is a so-called “front surface” (surface visually recognized after construction). Therefore, in this specification, the direction in which the uppermost layer (surface protective layer or the like) of the design layer of the decorative material exists is referred to as “upper” and the opposite side is referred to as “back” or “lower”. In the plywood constituting the decorative material of the present invention, the surface on the first layer side of the plywood is a so-called “front surface”, and is the surface on the side laminated with the design layer. Therefore, in this specification, the direction of the surface on the first layer side of the plywood is referred to as “up”, and the opposite side is referred to as “back” or “down”.

1. The decorative material of the present invention is a decorative material having a design layer on the first layer of a plywood having at least a first layer and a second layer in order from the top, wherein (1) the first layer and The second layer is a wood material, (2) the thickness of the first layer is less than 1.0 mm, (3) the specific gravity of the second layer is greater than the specific gravity of the first layer, (4) The design layer is a synthetic resin decorative sheet having a total thickness of 0.2 to 0.7 mm.

  In the decorative material of the present invention having the above characteristics, the plywood constituting the decorative material has at least a first layer and a second layer in order from the top, and the first layer and the second layer are wood materials, Since the specific gravity of the second layer is larger than the specific gravity of the first layer, the hardness of the second layer is harder than the hardness of the first layer. For this reason, when the impact is applied from the first layer side of the plywood, the impact applied to the first layer is higher than the first layer because the thickness of the first layer is less than 1.0 mm. By receiving even a layer, the amount of dents as a plywood is finally suppressed. For this reason, the decorative material of this invention which has a design layer on the 1st layer of the said plywood can show the outstanding impact resistance combined with the design layer being a synthetic resin decorative sheet.

  Further, since the decorative material of the present invention is excellent in impact resistance, it is necessary to use a decorative sheet having a thick backer layer of, for example, 1 mm or more when laminated with a synthetic resin decorative sheet. In addition, the warpage and cracking caused by the shrinkage stress due to the difference in linear expansion between the synthetic resin decorative sheet and the plywood are suppressed, and since the projection on the surface of the decorative material is suppressed, the design is excellent.

  In this specification, “plywood” means a single board (tanban) cut by a rotary lace, a slicer, etc., and the plurality of single boards are bonded by making the fiber directions of the single boards substantially perpendicular to each other. This means a laminated wooden board. In addition, it is more preferable that the single plate is laminated so that three or more odd-numbered sheets are orthogonal to each other.

In addition, “specific gravity” in the present specification is a value measured by the following measuring method. That is, the plywood is cut out to a certain size, for example, 10 × 10 cm (FIG. 9A). The surface area of the plywood at this time is defined as S (cm ² ). In the case of the above-mentioned 10 × 10 cm, S is 100 cm ² . The cut plywood is left to dry in a dryer at a temperature of 103 ± 2 ° C. for 72 hours. Next, when the layer to be measured for measuring the specific gravity is located on the outermost layer (for example, the first layer), the weight m0 (g) and the thickness h0 (cm) of the plywood after drying are measured. Next, the layer to be measured (first layer) is shaved in the thickness direction from the surface to remove a part of the layer to be measured, thereby reducing the thickness of the layer to be measured (FIG. 9B). The weight m1 (g) and thickness h1 (cm) of the plywood after removing a part of the layer to be measured are measured. From the measured value, the specific gravity G of the layer to be measured is measured based on the following formula.
G = [m0 (g) −m1 (g)] / [(h0 (cm) −h1 (cm)) × S (cm ² )] (formula)

  When the layer to be measured is not located on the outermost layer of the plywood (for example, the second layer 22 in FIG. 10A), the layer (for example, the first layer stacked on the outermost layer side of the layer to be measured) 1 layer) is removed from the surface in the thickness direction, and the layer to be measured is made the outermost layer (FIG. 10 (b)), and a part of the layer to be measured is removed by the measurement method described above and measured. The specific layer may be measured by reducing the thickness of the target layer (FIG. 10C).

  Moreover, when measuring specific gravity, arbitrarily cut out three plywood, calculate each specific gravity G by the above-mentioned method, and let the average value of the three be the measured value of specific gravity.

[plywood]
The plywood constituting the decorative material of the present invention has at least a first layer and a second layer in order from the top. In the decorative material of the present invention, the first layer and the second layer are wood materials. Hereinafter, each layer will be described.

(First layer)
As will be described later, the tree species of the first layer is not limited as long as the specific gravity of the second layer is larger than the specific gravity of the first layer. The first layer is preferably a hardwood veneer. Specific examples of the first layer include poplar veneers, eucalyptus veneers, and Falkata veneers that are fast-growing trees. Among these, a poplar single plate is more preferable because it has a relatively high specific gravity among low specific gravity, excellent surface smoothness, and few nodes. Moreover, as the poplar single plate, a poplar single plate using Chinese poplar can be preferably used.

  In the present specification, the term “poplar” refers to cottonwood willows, American black willows, European black willows and the like represented by the willow family, and their breeding species and interspecific hybrids are also included. Also included are American whitewoods called yellow poplars of magnolia family.

  Further, in this specification, “Chinese poplar” is often referred to as Italian poplar or warm-zone poplar, and means a fast-growing poplar that is bred and grown in China.

  The specific gravity of the first layer is not particularly limited as long as it is smaller than the specific gravity of the second layer described later. The specific gravity of the first layer is preferably less than 0.50, and more preferably 0.40 or more and 0.47 or less. Due to the specific gravity within the above-mentioned range, the decorative material of the present invention exhibits much more excellent impact resistance.

  The thickness of the first layer is less than 1.0 mm. When the thickness of the first layer is 1.0 mm or more, the first layer receives most of the impact applied from the first layer side of the plywood, and the dent amount of the first layer increases. This reduces the appearance. The thickness of the first layer is preferably 0.9 mm or less, and more preferably 0.8 mm or less. The thickness of the first layer is preferably 0.3 mm or more, more preferably 0.4 mm or more, further preferably 0.5 mm or more, and particularly preferably 0.6 mm or more. When the thickness of the first layer is in the above range, it is further suppressed that minor irregularities such as nodes, grain, cracks, and chips of the second layer are visually recognized from the surface of the decorative material.

  The first layer preferably has no nodes on the surface. When the first layer has no nodes on the surface, the smoothness of the surface of the plywood is further improved. Further, even if the first layer has a node on the surface, it is preferable that the first layer has fewer nodes than the second layer.

(Second layer)
As the second layer, the tree species is not limited as long as the specific gravity is larger than the specific gravity of the first layer. As the second layer, a eucalyptus veneer is preferable in that it has a relatively high specific gravity.

  The specific gravity of the second layer is greater than the specific gravity of the first layer. The specific gravity of the second layer is preferably 0.50 or more, and more preferably 0.55 or more. Due to the specific gravity within the above-mentioned range, the decorative material of the present invention exhibits much more excellent impact resistance.

  The thickness of the second layer is preferably 1.0 mm or more, and preferably 1.3 mm or more. When the lower limit of the thickness of the second layer is within the above range, the decorative material of the present invention exhibits even more excellent impact resistance.

  The second layer may have a node on at least a part of the surface. Since the plywood has the first layer, even if the second layer has a node on at least a part of the surface, it is suppressed from being projected on the surface of the plywood, and is projected on the surface of the decorative material. Is also suppressed.

  The layer structure of the plywood is not particularly limited as long as it has at least a first layer and a second layer, and several single plates, which are thin plates obtained by thinly cutting thick wood, are bonded together. In the above-mentioned plywood, it is more preferable that the above-mentioned single plate is bonded so that odd-numbered sheets are so that the grain is mutually orthogonal.

  As long as the plywood has at least the first layer and the second layer in order from the top, the plywood may have a layer configuration having another woody layer. As such a layer configuration, the first layer is the outermost surface, the second layer is stacked under the first layer, and another wooden layer is stacked thereunder, so that the layer configuration has an odd number of wooden layers. Is mentioned. As such a layer configuration, for example, a plywood having a first layer 11 / second layer 12 / third layer 13 / fourth layer 14 / fifth layer 15 in order from the top, like the plywood 1 in FIG. Like the plywood 2 in FIG. 2, a plywood having a first layer 21 / second layer 22 / third layer 23 / fourth layer 24 / fifth layer 25 / sixth layer 26 / seventh layer 27 in order from the top. Can be mentioned. The number of wood layers of plywood is not limited to 5 or 7 layers, and may be any number, but 3 to 9 layers are preferable, and 5 to 7 layers are more preferable. Moreover, it is preferable that the number of the wood layers of the said plywood is an odd number at the point which can suppress further the curvature of a plywood and a decorative material.

  In the plywood 1 shown in FIG. 1, the same layer of veneer is used as the first layer 11 on the front surface called the face and the fifth layer 15 on the back surface called the back, and the second layer 12 to the fourth layer. 14 may be the same tree species, but it is preferable to use the same tree species veneer as the first layer 11, the third layer 13, and the fifth layer 15. The second layer 12 and the fourth layer 14 are preferably made of the same tree species. As a specific layer structure of the plywood of FIG. 1, a layer structure having poplar single plate / eucalyptus single plate / poplar single plate / eucalyptus single plate / poplar single plate in order from the top is mentioned.

  In the plywood 2 shown in FIG. 2, the same layer of single veneer is used as the first layer 21 on the front surface called the face and the seventh layer 27 on the back surface called the back, and the second layer 22 to the sixth layer. A single plate of the same tree species may be used as the first layer 21, the third layer 23, the fifth layer 25, and the seventh layer 27. The second layer 22, the fourth layer 24, and the sixth layer 26 are preferably made of the same tree species. As a specific layer structure of the plywood of FIG. 2, the layers having poplar single plate / eucalyptus single plate / poplar single plate / eucalyptus single plate / poplar single plate / eucalyptus single plate / poplar single plate in order from the top. A configuration is mentioned.

[Design layer]
The decorative material of the present invention has a design layer on the first layer of the plywood. That is, in the decorative material of the present invention, the design layer is laminated on the surface of the first layer opposite to the side on which the second layer is laminated. Hereinafter, the design layer will be described.

  In the decorative material of the present invention, the design layer is a synthetic resin decorative sheet. In the present specification, a synthetic resin decorative sheet is a decorative sheet in which almost all layers constituting the decorative sheet are made of synthetic resin. As will be described later, the synthetic resin is formed on some layers such as a surface protective layer. Other additives such as inorganic fillers and organic substances may be included.

  The total thickness of the design layer is 0.2 mm or more. If the total thickness of the design layer is less than 0.2 mm, the decorative material is inferior in impact resistance. The total thickness of the design layer is preferably 0.3 mm or more, and more preferably 0.4 mm or more. The total thickness of the design layer is 0.7 mm or less. When the total thickness of the design layer exceeds 0.7 mm, the decorative material is warped. The total thickness of the design layer is preferably 0.6 mm or less.

  The design layer is a synthetic resin decorative sheet. By using a synthetic resin decorative sheet as the design layer, the decorative material of the present invention can exhibit excellent impact resistance, and is excellent in weather resistance and water resistance. Hereinafter, the structure of the synthetic resin decorative sheet will be specifically described.

  The structure of the synthetic resin decorative sheet is not particularly limited, and for example, a base sheet, a pattern layer (solid ink layer / pattern ink layer), a transparent adhesive layer, a transparent resin layer, and a surface protective layer are preferable. . A substrate sheet, a pattern layer (solid ink layer / pattern ink layer), and a surface protective layer in this order can also be used. Further, as shown in FIG. 4A, the synthetic resin decorative sheet 6 (a) and the synthetic resin decorative sheet 6 (b) of FIG. It is also preferable to have a pattern layer (solid ink layer / pattern ink layer) 613, a transparent adhesive layer (not shown), a transparent resin layer 614 and a surface protective layer 615 in this order. Hereinafter, this design layer will be described as an example. In addition, a synthetic resin backer layer is a layer made of a synthetic resin that is laminated on the back surface of a design layer and that relaxes the influence of surface irregularities such as a wooden substrate and imparts impact resistance to the design layer.

(Substrate sheet)
As a base material sheet, the 1 type, or 2 or more types of laminated body of synthetic resin sheets, such as polyolefin, polyester, polyacryl, polyamide, polyurethane, and polystyrene, is mentioned.

  The thickness of the base sheet is preferably about 20 to 300 μm. The substrate sheet may be colored as necessary. Further, the surface may be subjected to surface treatment such as corona discharge treatment, plasma treatment, ozone treatment or the like, or a primer which is a base coating for improving the adhesion with an adjacent layer may be applied.

(Picture layer)
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.

(Transparent adhesive layer)
The transparent adhesive layer is provided between the pattern layer and the transparent resin layer as necessary. The transparent adhesive layer can be obtained, for example, by applying and drying a known dry lamination adhesive such as a two-component curable urethane resin.

  The thickness of the transparent adhesive layer after drying is preferably about 0.1 to 30 μm, and more preferably about 1 to 5 μm.

(Transparent resin layer)
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 Synthetic resins such as polymers, ionomers, acrylic acid esters, and methacrylic acid esters are exemplified. 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.

(Surface protective layer)
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 the design layer. The resin forming the surface protective layer preferably includes at least one curable resin such as a thermosetting resin or an ionizing radiation curable resin. In particular, ionizing radiation curable resins are preferable from the viewpoint of high surface hardness, productivity, and the like. Furthermore, from the viewpoint of further improving the weather resistance, an electron beam curable resin is most preferable.

  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 50 μm, preferably about 5 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 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-ray, electron beam, ion beam, etc. Among them, ultraviolet light and electron beam are preferable, and electron beam is more 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 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 5 to 50 μm, preferably about 5 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, Examples include diamond, gold sand and glass fiber.

  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.

(Backer layer made of synthetic resin)
As shown in FIGS. 4 (a) and 4 (b), the synthetic resin decorative sheet is synthesized on the lowermost layer of the synthetic resin decorative sheets 6 (a) and 6 (b), that is, on the plywood side of the design layer. It is preferable to have a resin backer layer 611. By having the synthetic resin backer layer, the impact resistance of the decorative material of the present invention is further improved.

  Examples of the resin constituting the synthetic resin 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-cyclohexanedimethanol, polyethylene terephthalate substituted with diethylene glycol, etc., so-called trade name PET-G (manufactured by Eastman Chemical Company)], polybutylene terephthalate, polyethylene naphthalate, polyethylene naphthalate-isophthalate copolymer, Polycarbonate, polyarylate, polyimide, polystyrene, polyamide, ABS and the like can be mentioned. These resins can be used alone or in combination of two or more.

Martens hardness of the synthetic resin backer layer is preferably 20~350N / mm ^2, more preferably 50~300N / mm ^2, more preferably ^{50~250N / mm 2, 75~250N / mm} 2 is particularly preferred. When the lower limit of the Martens hardness of the synthetic resin backer layer is within the above range, the impact resistance of the decorative material of the present invention is further improved. Moreover, when the upper limit of the Martens hardness of the synthetic resin backer layer is within the above range, the cohesive cracking of the plywood of the decorative material of the present invention is further suppressed.

  In this specification, Martens hardness is a value measured using a surface film physical property tester (PICODERTOR HM-500, manufactured by Fisher Instruments Co., Ltd.), and a specific measurement method is as follows. .

In this measurement method, using a diamond indenter (Vickers indenter) shown in FIG. 5 (a), a diamond indenter is pushed into a measurement sample as shown in FIG. 5 (b), and a pyramidal indentation h formed on the surface is formed. The surface area A (mm ² ) is calculated from the length of the diagonal line, and the hardness is obtained by dividing the test load F (N).

  The indentation condition is that at room temperature (laboratory environment temperature), as shown in the image diagram of FIG. 5C, first, a load of 0 to 5 mN is first applied for 10 seconds, and then the load of 5 mN is held for 5 seconds. Finally, unloading from 5 to 0 mN 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 the synthetic resin backer layer, the Martens hardness of the cross section of the synthetic resin backer layer was measured. In this case, the synthetic resin decorative sheet is embedded in a resin (cold curing type epoxy two-component curable resin), allowed to stand at room temperature for 24 hours or more and then cured, and then the cured embedded sample is mechanically polished. The cross section of the synthetic resin backer layer was exposed, and the Martens hardness of the cross section was measured by pushing a diamond indenter into the cross section.

  The Martens hardness of the synthetic resin backer layer can be appropriately set by 1) mixing a plurality of resin components, 2) adding an elastomer to the resin, or the like.

  The thickness of the synthetic resin backer layer is preferably 0.1 to 0.6 mm, more preferably 0.15 to 0.45 mm, and still more preferably 0.20 to 0.40 mm. When the lower limit of the thickness of the synthetic resin backer layer is within the above range, the impact resistance of the decorative material of the present invention is further improved. Moreover, when the upper limit of the thickness of the synthetic resin backer layer is within the above range, warping of the decorative material of the present invention is further suppressed.

  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, and then known dry lamination adhesives such as a two-component curable urethane resin on the pattern layer A synthetic resin layer backer layer prepared by laminating a transparent resin layer via a dry lamination method, a T-die extrusion method, etc., further forming a surface protective layer to produce a design layer intermediate, and a T-die extrusion method, etc. And a design layer intermediate can be performed by a method of laminating by thermal lamination.

  As shown in FIG. 4, an uneven pattern may be formed by embossing from the transparent resin layer side or 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.

  Since the decorative material of the present invention has the above-described configuration, it has excellent impact resistance, and the visual recognition from the surface of the design layer of the warpage and the appearance defects on the surface of the plywood is suppressed, and the design material is excellent.

2. Manufacturing method of decorative material The manufacturing method of the decorative material is not particularly limited, and can be manufactured by a conventionally known method. As said manufacturing method, the manufacturing method including the process of laminating | stacking a design layer on the 1st layer of a plywood is mentioned, for example.

  The method for laminating the design layer on the first layer of the plywood is not particularly limited, and examples thereof include a method for laminating these layers via an adhesive layer. Examples of the adhesive for forming the adhesive layer include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ionomer, butadiene / acrylonitrile rubber, neoprene rubber, natural Examples thereof include an adhesive containing rubber or the like as an active ingredient. Although the thickness of an adhesive bond layer is not limited, About 0.1-50 micrometers is preferable.

  By the steps described above, the design layer is laminated on the first layer of the plywood, and the decorative material is manufactured.

(Plywood manufacturing method)
In addition, the plywood used for a decorative material can be manufactured with the following manufacturing methods, for example.
A method for producing a plywood having a first layer and a second layer in order from at least the top,
(I) Step 1 for laminating the first layer and the second layer, and (II) After the step 1, the surface of the first layer is polished so that the thickness of the first layer is 1.0 mm. Having step 2 of adjusting to less than
(1) The first layer and the second layer are made of wood.
(2) The thickness of the first layer is less than 1.0 mm,
(3) The method for producing plywood, wherein the specific gravity of the second layer is larger than the specific gravity of the first layer.
The manufacturing method of the plywood is referred to as manufacturing method 1. Hereinafter, the manufacturing method 1 will be described.

(Process 1)
Step 1 is a step of laminating the first layer and the second layer. About the said 1st layer, the said 2nd layer, those thickness, and specific gravity, it is the same as the content demonstrated in the above-mentioned plywood.

  The method for laminating the first layer and the second layer is not particularly limited, and an adhesive is applied and laminated between the first layer and the second layer, and a press machine such as a multistage hot press machine is used. Then, lamination may be performed by hot pressing for about 3 to 7 minutes under conditions of a pressure of about 0.69 to 1.18 MPa and a temperature of about 100 to 130 ° C.

  When the plywood has the first layer, the second layer, and the other wood layers as shown in FIGS. 1 and 2, the adhesive is applied between the layers and laminated, and then laminated by the above-mentioned hot press. Good. The adhesive used between the layers is not shown in FIGS. 1 and 2 and is omitted. Moreover, the adhesive bond layer formed with an adhesive agent is not contained in layers, such as a 1st layer-a 7th layer which form the plywood demonstrated above.

  It does not specifically limit as an adhesive agent, The well-known adhesive for woodwork can be used widely. As an adhesive, for example, polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ionomer, butadiene-acrylonitrile rubber, neoprene rubber, natural rubber and the like are effective ingredients. Adhesives to be used. Examples of the thermosetting adhesive include melamine-based, phenol-based, urea-based (such as vinyl acetate-urea) adhesives.

  By the step 1 described above, the first layer and the second layer are laminated.

(Process 2)
Step 2 is a step of polishing the surface of the first layer after Step 1 and adjusting the thickness of the first layer to less than 1.0 mm. By laminating the first layer and the second layer in step 1 and then polishing the surface of the first layer in step 2, the thickness of the first layer can be made uniform.

  The polishing method for polishing the surface of the first layer is not particularly limited, and polishing can be performed using a sanding belt, a planar, a buff, a brush, or the like. Among these, a polishing method using a sanding belt is preferable in that the surface of the first layer after polishing can be smoothed.

  In step 2, the thickness of the first layer after polishing may be less than 1.0 mm, and the thickness of the first layer before polishing may be 1.0 mm or more. The thickness of the first layer before polishing is not particularly limited, and is about 0.8 to 1.3 mm.

  In step 2, the thickness of the first layer may be adjusted by polishing the surface of the first layer and also polishing the wood layer on the surface opposite to the surface on which the first layer of the produced plywood is laminated. For example, as shown in FIG. 1, when the plywood 1 has the fifth layer 15 on the opposite surface of the first layer 11, the surface of the first layer 11 is polished and the surface of the fifth layer 15 is also polished. May be. In addition, as shown in FIG. 2, when the plywood 2 has the seventh layer 27 on the surface opposite to the first layer 21, the surface of the first layer 21 is polished and the surface of the seventh layer 27 is also polished. May be.

  By the step 2 described above, the thickness of the first layer is adjusted to less than 1.0 mm.

Moreover, the plywood used for a decorative material can also be manufactured with the following manufacturing methods. A method for producing a plywood having a first layer and a second layer in order from at least the top,
(I) A step of preparing a poplar veneer having an air-dry specific gravity of 0.4 to 0.47 as the first layer and a eucalyptus veneer having an air-dry specific gravity of 0.5 to 0.9 as the second layer. 1,
(II) Step 2 of laminating the first layer and the second layer, and
(III) The manufacturing method of the plywood which has the process 3 which polishes the surface of the said 1st layer after the said process 2, and adjusts the thickness of the said 1st layer to less than 1.0 mm.

  Step 1 in the production method 2 prepares a poplar veneer having an air-dry specific gravity of 0.4 to 0.47 as a first layer and a eucalyptus veneer having an air-dry specific gravity of 0.5 to 0.9 as a second layer. It is a process to do. In the manufacturing method 2, the 1st layer and 2nd layer whose air-dry specific gravity is the said range are prepared, and it uses for the process 2 demonstrated below.

  Steps 2 and 3 in manufacturing method 2 are the same as steps 1 and 2 in manufacturing method 1 described above, except that the first layer and the second layer having an air-dry specific gravity within the above range prepared in step 1 are used. It is. In the manufacturing method 2, a poplar veneer having an air-dry specific gravity of 0.4 to 0.47 is used for the first layer, and a eucalyptus veneer having an air-dry specific gravity of 0.5 to 0.9 is used for the second layer. A plywood having excellent impact resistance can be produced.

  In the present specification, the air-dry specific gravity means a specific gravity calculated by dividing the weight of wood in the air-dried state by its volume, and the air-dried state has a moisture content of 15%. The state of the wood at the time.

  By the manufacturing method 2 demonstrated above, the plywood used for the decorative material of this invention can be manufactured.

  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.

In the following examples, comparative examples, and reference examples, the specific gravity of each layer was measured from the produced plywood, and the results were as follows.
Poplar single plate: 0.43
Eucalyptus veneer: 0.55

Example 1
(Production of plywood)
As a first layer, a poplar single plate having a thickness of 1.3 mm and a specific gravity of 0.43 was prepared by slicing poplar. Moreover, the eucalyptus single board of thickness 2.7mm and specific gravity 0.55 was prepared by slicing eucalyptus as a 2nd layer. The prepared poplar veneer and eucalyptus veneer are arranged in order from the top to the first to the seventh layer through the urea adhesive so that the grain direction of the adjacent wood layer is orthogonal, the poplar veneer / eucalyptus veneer / Lamination was carried out so as to have a layer structure of poplar single plate / eucalyptus single plate / poplar single plate / eucalyptus single plate / poplar single plate to prepare a laminate of wood layers.

  The laminate of the above wood layers was hot-pressed for 5 minutes under the conditions of a pressure of 0.78 MPa and a temperature of 110 ° C. using a multistage hot press, and the layers were bonded together. By hot pressing, the thickness of the poplar single plate was 1.2 mm, the thickness of the eucalyptus single plate was 2.5 mm, and the total thickness of the laminate was 12.3 mm.

  The first layer and the seventh layer were sanded and polished so that the thickness of the first layer was 0.9 mm and the total thickness of the plywood was 11.5 mm. That is, each thickness from the first layer to the sixth layer is 0.9 mm / 2.5 mm / 1.2 mm / 2.5 mm / 1.2 mm / 2.5 mm, and by sanding polishing the seventh layer The thickness was adjusted to produce a plywood having a total thickness of 11.5 mm.

(Production of synthetic resin decorative sheet)
A gravure coating method applies urethane cellulose resin (added 5 parts by weight of hexamethylene diisocyanate to 100 parts by weight of a mixture of urethane and nitrified cotton) on one side of a colored polypropylene film having a thickness of 60 μm subjected to double-sided corona discharge treatment. A back primer layer was formed. The back primer layer was 1 μm.

  Next, a solid ink layer and a pattern ink layer are sequentially formed by gravure printing using a printing ink containing an acrylic urethane resin (100 parts by weight of acrylic polyol and 5 parts by weight of hexamethylene diisocyanate) as a binder. A patterned ink layer was formed. The ink layer was 3 μm.

  Next, after applying a urethane-based adhesive on the pattern layer, a transparent resin layer was formed by heating and extruding a propylene-based resin with a T-die extruder so as to have a thickness of 80 μm.

  The transparent resin layer is subjected to corona discharge treatment, and a surface protective layer is applied to the treated surface by an acrylic urethane-based resin (100 parts by weight of acrylic polyol added with 5 parts by weight of hexamethylene diisocyanate) by a gravure coating method. A primer layer was formed. The primer layer for the surface protective layer was 1 μm.

  A urethane acrylate electron beam curable resin is applied onto the primer layer for the surface protective layer by a roll coating method, dried, and then applied to an uncured electron radiation curable resin layer in an environment having an oxygen concentration of 200 ppm or less ( A surface protective layer made of an electron radiation curable resin was formed by irradiating with an accelerating voltage of 175 KeV and an irradiation amount of 5 Mrad. The surface protective layer was 15 μm.

  Subsequently, embossing is performed from the surface protective layer side with a wood grain conduit embossed plate or a bark / abstract embossed plate with a plate depth of 50 μm to form a wood grain conduit or bark / abstracted uneven pattern with a thickness of 0.16 mm The intermediate of the design layer was obtained.

A synthetic resin sheet (synthetic resin backer layer) was formed by co-extrusion of A-PET with a T-die extruder. The thickness of the synthetic resin backer layer was 0.25 mm, and the Martens hardness was 150 N / mm ² .

  A synthetic resin backer layer was further laminated on the back primer layer of the design layer intermediate by a dry laminating method with a urethane adhesive layer interposed therebetween to produce a synthetic resin decorative sheet as a design layer. The synthetic resin decorative sheet was 0.41 mm. The synthetic resin decorative sheet is referred to as a decorative sheet (1).

(Production of cosmetic materials)
The synthetic resin backer layer side of the synthetic resin decorative sheet and the first layer side surface of the plywood are bonded together with a water-soluble emulsion adhesive and cut into a predetermined dimension (145 mm x 900 mm). A decorative material was prepared. The following water-soluble emulsion adhesives were used.

Water-soluble emulsion-based adhesive Main agent: “BA-10L” manufactured by Japan Coating Resin Co., Ltd., modified ethylene / vinyl acetate curing agent: “BA-11B” manufactured by Japan Coating Resin Co., Ltd., isocyanate-based compounding ratio: Main agent: Curing agent = 100: 2.5 (mass ratio)

Example 2
Table 1 shows the tree species and thicknesses of the first layer and the second layer of the plywood. That is, each layer from the first layer to the seventh layer is made of poplar single plate 0.8 mm / eucalyptus single plate 2.5 mm / poplar single plate 1.2 mm / eucalyptus single plate 2.5 mm / poplar single plate 1.2 mm. / The Eucalyptus veneer was 2.5 mm, and the thickness was adjusted by sanding polishing the poplar veneer as the seventh layer, so that the total thickness of the plywood was 11.5 mm. Other than that was carried out similarly to Example 1, and produced the cosmetic material.

Example 3
Table 1 shows the tree species and thicknesses of the first layer and the second layer of the plywood. That is, each layer from the first layer to the seventh layer is made of poplar single plate 0.6 mm / eucalyptus single plate 2.5 mm / poplar single plate 1.2 mm / eucalyptus single plate 2.5 mm / poplar single plate 1.2 mm. / The Eucalyptus veneer was 2.5 mm, and the thickness was adjusted by sanding polishing the poplar veneer as the seventh layer, so that the total thickness of the plywood was 11.5 mm. Other than that was carried out similarly to Example 1, and produced the cosmetic material.

Example 4
(Production of plywood)
As a first layer of plywood, a poplar single plate having a thickness of 1.4 mm and a specific gravity of 0.43 was prepared by slicing poplar. As the second layer, a eucalyptus veneer having a thickness of 2.7 mm and a specific gravity of 0.55 was prepared by slicing eucalyptus. Poplar veneer / eucalyptus veneer in order from the top to the seventh layer from the first layer through the urea adhesive so that the grain direction of the adjacent wood layer is orthogonal to the prepared poplar veneer and eucalyptus veneer A laminate of wood layers was prepared so as to have a layer structure of: / poplar single plate / eucalyptus single plate / poplar single plate / eucalyptus single plate / poplar single plate.

  The laminate of the above wood layers was hot-pressed for 5 minutes under the conditions of a pressure of 0.78 MPa and a temperature of 110 ° C. using a multistage hot press, and the layers were bonded together. By hot pressing, the thickness of the poplar single plate was 1.3 mm, the thickness of the eucalyptus single plate was 2.5 mm, and the total thickness of the laminate was 12.7 mm.

  Table 1 shows the tree species and thicknesses of the first layer and the second layer of the plywood. That is, each layer from the first layer to the seventh layer is made of poplar single plate 0.3 mm / eucalyptus single plate 2.5 mm / poplar single plate 1.3 mm / eucalyptus single plate 2.5 mm / poplar single plate 1.3 mm. / The Eucalyptus veneer was 2.5 mm, and the thickness was adjusted by sanding polishing the poplar veneer as the seventh layer, so that the total thickness of the plywood was 11.5 mm. Other than that was carried out similarly to Example 1, and produced the cosmetic material.

Example 5
The resin forming the synthetic resin sheet (synthetic resin backer layer) of the synthetic resin decorative sheet was changed to polypropylene resin (PP). The thickness of the synthetic resin backer layer was 0.25 mm, and the Martens hardness was 160 N / mm ² . The exception was the same as in Example 1, and a synthetic resin decorative sheet as a design layer was prepared. The synthetic resin decorative sheet is referred to as a decorative sheet (2).

  A cosmetic material was produced in the same manner as in Example 1 except that the decorative sheet (2) was used instead of the decorative sheet (1).

Example 6
As a first layer of plywood, a poplar single plate having a thickness of 3.5 mm and a specific gravity of 0.43 was prepared by slicing poplar. Moreover, the eucalyptus single board of thickness 3.5mm and specific gravity 0.55 was prepared by slicing eucalyptus as a 2nd layer. Poplar veneer / eucalyptus veneer in order from the top to the 5th layer from the 1st layer through the urea adhesive so that the grain direction of the adjacent wood layer is orthogonal to the prepared poplar veneer and eucalyptus veneer A laminate of wood layers was prepared by laminating so as to have a layer structure of / poplar single plate / eucalyptus single plate / poplar single plate.

  The laminate of the above wood layers was hot-pressed for 5 minutes under the conditions of a pressure of 0.78 MPa and a temperature of 110 ° C. using a multistage hot press, and the layers were bonded together. By hot pressing, the thickness of the poplar single plate was 3.2 mm, the thickness of the eucalyptus single plate was 3.2 mm, and the total thickness of the laminate was 16.0 mm.

  The number of plywood layers was five, and the tree species and thicknesses of the first layer and the second layer were as shown in Table 1. That is, each layer from the first layer to the fifth layer is made of poplar veneer 0.9 mm / eucalyptus veneer 3.2 mm / poplar veneer 3.2 mm / eucalyptus veneer 3.2 mm as the fifth layer. The thickness was adjusted by sanding polishing the poplar single plate, so that the total thickness of the plywood was 11.5 mm. Other than that was carried out similarly to Example 1, and produced the cosmetic material.

Comparative Example 1
(Production of plywood)
A plywood was produced in the same manner as in Example 1.

(Production of cosmetic materials)
As a veneer for forming the design layer, a 0.20 mm thick oak veneer was prepared. The veneer and the surface on the first layer side of the plywood were bonded together with a water-soluble emulsion adhesive.

Next, apply a urethane acrylate UV curable paint ("Aurex No. 811", manufactured by China Paint Co., Ltd.) three times in the order of natural roll coat method, reverse roll coat method and natural roll coat method to the surface of the veneer. An undercoat layer consisting of 10 g / m ² was formed. Immediately in the air, ultraviolet rays were irradiated with an electroded ultraviolet lamp to cure the undercoat layer.

Subsequently, the intermediate layer which consists of a coating film of 12 g / m < ² > was formed on the hardened undercoat layer with the natural roll coat method. Immediately in the air, the intermediate layer was cured by irradiating ultraviolet rays with an electroded ultraviolet lamp. The surface of the cured intermediate layer was polished with No. 360 polishing paper and the powder generated during polishing was removed.

Subsequently, the top coat layer which consists of a coating film of 10 g / m < ² > was formed in the cured intermediate | middle layer surface by the natural roll coat method. In a nitrogen gas atmosphere with an oxygen concentration of 0.5%, the surface coating layer was formed by irradiating the top coat layer with ultraviolet light using an electrodeless ultraviolet lamp to cure it. Cut into predetermined dimensions (145 mm × 900 mm) to produce a decorative material. The thickness of the surface protective layer was 30 μm.

Comparative Example 2
Table 1 shows the tree species and thicknesses of the first layer and the second layer. That is, each layer from the first layer to the seventh wood layer is made of poplar veneer 1.2 mm / poplar veneer 2.5 mm / poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm / poplar veneer 1 The thickness of the plywood was adjusted to 11.5 mm by sanding polishing the poplar veneer as the seventh layer. Other than that was carried out similarly to Example 1, and produced the cosmetic material.

(Evaluation)
The cosmetic materials of Examples and Comparative Examples produced as described above were evaluated by the following methods.

(1) Impact resistance test (DuPont impact test)
JISK5600-5-3 (1999) Coating General Test Method Mechanical Properties of Coating Film-Section 3: Weight Drop Resistance Surfaces of cosmetic materials obtained in Examples and Comparative Examples according to the DuPont impact test described in DuPont A shooting die having a hemispherical tip with a radius of 6.35 mm was allowed to stand on top, and a 500 g weight was dropped from a height of 300 mm onto the shooting die. The amount of dents was measured with a measuring instrument (Ozaki Mfg. Co., Ltd. T2-127) as shown in FIG.

(2) Prepare a cosmetic material with a 145 mm cold test width and a length of 300 mm, and let it stand on the base. “Leave at 80 ° C. for 2 hours, then leave at −20 ° C. for 2 hours” is one cycle. The cycle was repeated 10 times. Next, the amount of warpage and appearance were evaluated according to the following procedure.
If a cosmetic material of the above size cannot be prepared, use a cosmetic material with a similar shape when viewed in plan, and perform evaluation by correcting the following evaluation criteria with the size of the cosmetic material. Shall.

(I) Warpage amount evaluation As shown in FIG. 7, the maximum amount of warpage in the vicinity of the midpoint of the length of the decorative material (150 mm) was measured and evaluated according to the following evaluation criteria. In FIG. 7, FIG. 7A shows a state before the test of the base 3 and the decorative material having the design layer 5 on the plywood 4, and FIGS. 7B, 7 </ b> C, and 7 </ b> D. Indicates the base 3 and the decorative material after the cold heat test, and in FIGS. 7B, 7C, and 7D, d indicates the amount of warpage. In the state of FIG. 7B, the warpage amount d is a negative value, and in the state of FIG. 7C, the warpage amount d is a positive value. When the state shown in FIG. 7C is warped, as shown in FIG. 7D, the decorative material may be placed upside down on the base 3, and the warping amount d may be measured. Moreover, if it is evaluation more than B in this test, it will be evaluated that there is no problem in actual use.
A: Less than ± 0.6 mm B: -0.6 mm or more and less than -1 mm, or 0.6 mm or more and less than 1 mm C: -1 mm or less, or 1 mm or more

(Ii) Appearance evaluation The appearance of appearance defects (projection of nodes, cohesive cracking of the first layer) due to the plywood on the decorative board surface was visually observed and evaluated according to the following evaluation criteria. As shown in FIG. 8, the cohesive crack of the first layer is a crack 111 generated at the end of the first layer 11 in the decorative material having the synthetic resin decorative sheet 6 on the first layer 11 of the plywood 1. It is. Moreover, if it is evaluation more than B in this test, it can be evaluated that there is no problem in actual use.
A: Appearance failure cannot be confirmed B: Appearance failure can be confirmed but is minor C: Appearance failure can be clearly confirmed

(3) Weather resistance test About the decorative material of Example 1 and Comparative Example 1, using the sunshine weather meter: WEL-300 (manufactured by Suga Test Instruments Co., Ltd.), the sunshine was applied from the decorative layer side of the cosmetic material under the following conditions. The appearance state when irradiated with carbon arc light for 1000 hours was visually evaluated. Note that one cycle from Step 1 to Step 2 was set to 2 hours, and after one cycle, the test was repeated as Step 1 in the second cycle.
<Step 1>
Black panel temperature: 63 ° C, humidity: 50%
・ Operating time: 1 hour 42 minutes <Step 2>
・ Inside temperature: 40 ℃, Humidity: 90%
・ Operating time: 18 minutes

  The results are shown in Table 1.

Reference example 1
A plywood identical to the plywood used in Example 1 was produced and used as the plywood of Reference Example 1.

Reference example 2
A plywood identical to the plywood used in Example 2 was produced and used as the plywood of Reference Example 2.

Reference example 3
A plywood identical to the plywood used in Example 3 was produced and used as the plywood of Reference Example 3.

Reference example 4
A plywood identical to the plywood used in Example 4 was produced and used as the plywood of Reference Example 4.

Reference Example 5
A plywood identical to the plywood used in Comparative Example 2 was produced and used as the plywood of Reference Example 5.

Reference Example 6
A plywood identical to the plywood used in Example 6 was produced and used as the plywood of Reference Example 6.

(Evaluation)
The above-mentioned impact resistance test (DuPont impact test) was performed on the plywood of the reference example produced as described above.

  The results are shown in Table 2.

1,2,4. Plywood 11,21. 1st layer 12,22. Second layer 13,23. Third layer 14, 24. Fourth layer 15, 25. Fifth layer 111. Crack 211. The first layer 221. Second layer with reduced thickness 26. Sixth layer 27. Seventh layer3. Base 5 Design layers 6, 6 (a), 6 (b). Synthetic resin decorative sheet 611. Synthetic resin backer layer 612. Base sheet 613. Picture layer 614. Transparent resin layer 615. Surface protective layer d. Warpage amount h. Pyramid depression m. Measuring instrument

Claims (13)

A decorative material having a design layer on the first layer of a plywood having a first layer and a second layer in order from the top,
(1) The first layer and the second layer are made of wood.
(2) The thickness of the first layer is less than 1.0 mm,
(3) The specific gravity of the second layer is greater than the specific gravity of the first layer,
(4) The design layer is a synthetic resin decorative sheet having a total thickness of 0.2 mm to 0.7 mm.
A cosmetic material characterized by that.   The decorative material according to claim 1, wherein the synthetic resin decorative sheet has a thickness of 0.3 mm to 0.6 mm.   The decorative material according to claim 1, wherein the synthetic resin decorative sheet has a synthetic resin backer layer on the plywood side. The synthetic resin backer layer, Martens hardness is 50~300N / mm ^2, the decorative material according to claim 3.   The cosmetic material according to claim 1, wherein the outermost layer of the synthetic resin decorative sheet is an ionizing radiation curable resin layer.   The said synthetic resin decorative sheet is a decorative material according to claim 5, wherein the ionizing radiation curable resin layer is an electron beam curable resin layer.   The cosmetic material according to claim 1, wherein the first layer is a poplar veneer and the second layer is a eucalyptus veneer.   The cosmetic material according to claim 1, wherein the first layer is a Chinese poplar veneer.   The cosmetic material according to claim 1, wherein the first layer is a hardwood veneer.   The decorative material according to claim 1, wherein the specific gravity of the first layer is less than 0.50, and the specific gravity of the second layer is 0.50 or more.   The cosmetic material according to claim 1, wherein the thickness of the first layer is 0.6 mm or more and 0.8 mm or less.   The decorative material according to claim 1, wherein the number of layers of the plywood is 5 layers or 7 layers.   The decorative material according to claim 1, which is a floor decorative material.