JP7040524B2 - Cosmetic material - Google Patents

Description

The present invention relates to a decorative material.

Conventionally, as a wood base material for a decorative material such as a floor decorative material, a wood layer such as HDF or a lauan plywood on which a lauan material is laminated has been used. The plywood is a thin wood veneer called a veneer cut by a rotary race, slicer, etc., and the fiber directions of the veneer are almost perpendicular to each other, and a plurality of veneers are bonded together. It is a laminated wood board.

Logging of Lauan wood is restricted due to resource depletion issues. Therefore, the distribution volume of Lauan lumber in the market is drastically decreasing, and it is considered to suppress the use of Lauan lumber by using plywood (so-called de-Lauan lumber) that does not use Lauan lumber as much as possible as a wood base material. As such plywood (de-lawan lumber), plywood using coniferous plywood or early-maturing wood for a part or all of the plywood is used.

However, since the de-Lauan material is not sufficiently hard, the impact resistance is inferior, and the appearance defect of the surface of the plywood using the de-Lauan material is visually recognized in the decorative material in which the design layer is laminated on the surface of the plywood. There's a problem.

As a plywood that solves the above-mentioned problems, it has been proposed to use a plywood in which a wood base material (MDF, HDF, etc.) having a hardness and a smooth surface is bonded to the surface of the de-lawan material as the floor material. (See, for example, Patent Documents 1 and 2).

However, since MDF and HDF have a large dimensional change rate as compared with the de-Lauan material, the decorative material using these plywoods has a problem that warpage occurs.

Further, instead of laminating a wood base material having a smooth surface, a floor 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, and the shrinkage stress due to the linear expansion difference between the decorative sheet and the wood plywood generated when the temperature changes makes the decorative material. Warpage occurs, a load is generated between the decorative sheet and the wood plywood, and in some cases, a part of the wood plywood is cracked, and appearance defects are visually recognized on the surface of the decorative material, resulting in deterioration of design. I have something to do.

Therefore, it is desired to develop a decorative material having excellent impact resistance, warpage, and design.

Japanese Unexamined Patent Publication No. 2004-107905 Japanese Unexamined Patent Publication No. 2012-214981 Japanese Unexamined Patent Publication No. 2013-083142

An object of the present invention is to provide a decorative material having excellent impact resistance, warpage, and design.

As a result of diligent research, the present inventors have found that in a decorative material having a design layer on the first layer of plywood having at least the first layer and the second layer in order from the top, the first layer and the second layer are made of wood. It is a material, the thickness of the first layer is less than 1.0 mm, the specific gravity of the second layer is larger than the specific gravity of the first layer, and the design layer is a synthetic resin having a thickness of 0.20 or more and 0.70 mm or less. It has been found that the above-mentioned object can be achieved by the configuration of the decorative sheet, and the present invention has been completed.

That is, the present invention relates to the following decorative materials.
1. 1. A decorative material having a design layer on the first layer of plywood having at least the first layer and the second layer in order from the top.
(1) The first layer and the second layer are made of wood, and 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 larger than the specific gravity of the first layer.
(4) The design layer is a synthetic resin decorative sheet having a total thickness of 0.20 or more and 0.70 mm or less.
A decorative material characterized by that.
2. 2. Item 2. The decorative material according to Item 1, wherein the synthetic resin decorative sheet has a thickness of 0.25 mm or more and 0.45 mm or less.
3. 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 3. The decorative 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 decorative material according to Item 1, wherein the surface layer of the synthetic resin decorative sheet is an ionizing radiation curable resin layer.
6. Item 5. The decorative material according to Item 5, wherein the synthetic resin decorative sheet is an electron beam curable resin layer in which the ionizing radiation curable resin layer is an electron beam curable resin layer.
7. Item 2. The decorative 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 decorative material according to Item 1, wherein the first layer is a Chinese poplar veneer.
9. Item 2. The decorative material according to Item 1, wherein the first layer is a hardwood veneer.
10. Item 2. The decorative material according to Item 1, wherein the first layer has a specific gravity of less than 0.50, and the second layer has a specific density of 0.50 or more.
11. Item 2. The decorative material according to Item 1, wherein the thickness of the first layer is 0.6 mm or more and 0.9 mm or less.
12. Item 2. The decorative material according to Item 1, wherein the second layer has knots on at least a part of the surface on the side of the first layer, and the knots of the first layer are less than the knots of the second layer. ..
13. Item 2. The decorative material according to Item 1, wherein the number of layers of the plywood is 5 or 7 layers.
14. Item 2. The decorative material according to Item 1, which is a decorative material for floors.
15. A decorative sheet made of synthetic resin used for the design layer of the decorative material according to Item 1.

The decorative material of the present invention is excellent in impact resistance, warpage, and design.

It is a schematic diagram which shows an example of the layer structure of the plywood which constitutes the decorative material of this invention. It is a schematic diagram which shows an example of the layer structure of the plywood which constitutes the decorative material of this invention. It is a two-sided view which shows an example of the decorative material of this invention. It is a schematic diagram which shows an example of the synthetic resin decorative sheet which constitutes the decorative material of this invention. It is a figure which shows the diamond indenter (a) used for the measurement of Martens hardness, the schematic diagram (b) of a pushing operation, and an example (c) of a pushing load and displacement. It is a schematic diagram which shows an example of the measuring method of the dent amount in the impact resistance test evaluation. It is a schematic diagram which shows an example of the warp amount d in the warp amount evaluation. It is a schematic diagram which shows an example of the agglutination crack of the 1st layer in the appearance evaluation. It is a schematic diagram which shows an example of the specific gravity measuring method. (A) is a diagram in which plywood is cut out to a certain size, and (b) is a diagram in which the thickness of the layer to be measured is reduced. It is a schematic diagram which shows an example of the specific gravity measuring method. (A) is a diagram in which plywood is cut out to a certain size, (b) is a diagram in which the layer laminated on the layer to be measured is removed from the surface in the thickness direction, and (c) is a measurement. It is the figure which made the thickness of the target layer 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" (a surface visually recognizable after construction). Therefore, in the present specification, the direction in which the uppermost layer (surface protective layer, etc.) of the design layer of the decorative material exists is referred to as "upper", and the opposite side thereof is referred to as "back" or "lower". Further, in the plywood constituting the decorative material of the present invention, the surface on the first layer side of the plywood is the so-called "front surface", which is the surface on the side laminated with the design layer. Therefore, in the present specification, the direction of the surface of the plywood on the first layer side is referred to as "upper", and the opposite side thereof is referred to as "back" or "lower".

1. 1. Decorative material The decorative material of the present invention is a decorative material having a design layer on the first layer of plywood having at least the first layer and the second layer in order from the top, and (1) the first layer and the decorative material. The second layer is 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 larger than the specific gravity of the first layer, and (4). The design layer is characterized in that the total thickness is 0.20 or more and 0.70 mm or less.

The decorative material of the present invention having the above-mentioned characteristics finally suppresses the amount of dent as plywood by receiving the impact applied to the first layer even in the second layer when an impact is applied from the first layer side of the plywood. Will be done. Therefore, the decorative material of the present invention having the design layer on the first layer of the plywood can exhibit excellent impact resistance in combination with having the design layer of the synthetic resin decorative sheet.

Further, since the plywood itself has excellent impact resistance, the decorative material of the present invention has a thick backer layer of, for example, 1 mm or more when laminated with a design layer of a synthetic resin decorative sheet to form a decorative material. It is not necessary to use a decorative sheet, and warpage and cracking caused by the difference in linear expansion rate between the design layer of the synthetic resin decorative sheet and plywood are suppressed, and the design is excellent.

In addition, in this specification, "plywood" uses a veneer (tanban) cut by a rotary race, a slicer, etc., and the fiber directions of the veneer are substantially perpendicular to each other, and a plurality of veneers are bonded. It means a wood veneer that has been laminated. It is more preferable that three or more odd-numbered veneers are laminated so that the grain of wood is orthogonal to each other.

Further, the "specific gravity" in the present specification is a value measured by the following measuring method. That is, the plywood is cut into a certain size, for example, a size of 10 × 10 cm (FIG. 9 (a)). The surface area of the plywood at this time is 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 under a temperature condition 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 dried plywood are measured. Next, the layer to be measured (first layer) is scraped from the surface in the thickness direction to remove a part of the layer to be measured to reduce the thickness of the layer to be measured (FIG. 9 (b)). The weight m1 (g) and the thickness h1 (cm) of the plywood after removing a part of the layer to be measured are measured. From the above measured values, 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 )] (Equation)
In the above formula, the unit is g / cm ³ , but the unit is omitted and the specific gravity is used.

When the layer to be measured is not located on the outermost surface layer of the plywood (for example, the second layer 22 in FIG. 10A), the layer laminated on the outermost surface layer side of the layer to be measured (for example, the first layer). 1 layer) is scraped from the surface in the thickness direction to remove all of it, and the layer to be measured is used as the outermost layer (FIG. 10 (b)), and a part of the layer to be measured is removed by the above-mentioned measurement method and measured. The thickness of the target layer may be reduced (FIG. 10 (c)), and the specific gravity may be measured.

Further, when measuring the specific gravity, three plywoods are arbitrarily cut out, each specific gravity G is calculated by the above-mentioned method, and the average value of the three is used as the measured value of the specific gravity. In addition, the specific gravity is basically measured in the part excluding the node.

[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.

(1st layer)
As described later, the type of the tree of the first layer is not limited as long as the specific gravity is smaller than the specific density of the second layer. As the first layer, hardwood veneer is preferable. Specific examples of the first layer include poplar veneer, eucalyptus veneer, and falcata veneer, which are early-maturing trees. Among these, poplar veneer is more preferable in that it has a relatively high specific density among low specific densities, has excellent surface smoothness, and has few knots. Further, as the poplar veneer, a poplar veneer using Chinese poplar can be preferably used.

In addition, in this specification, "poplar" means Populus nigra represented by Salixaceae, American aspen, European aspen, etc., and includes breeding species and interspecific hybrids thereof. It also includes American white wood called yellow poplar of the Magnolia family.

Further, in the present specification, "Chinese poplar" is often referred to as Italian poplar or warm-zone poplar, and means early-maturing poplar bred and bred in China.

The specific density of the first layer is not particularly limited as long as it is smaller than the specific gravity of the second layer described later, but the specific gravity of the first layer is preferably less than 0.50, and the preferable lower limit value is more than 0.40, 0.42. As mentioned above, 0.45 or more is mentioned, and preferable upper limit values are 0.48 or less and 0.47 or less. The range of the specific gravity of the first layer is particularly preferably 0.42 or more and 0.47 or less. With the specific gravity in the above range, the decorative material of the present invention exhibits even better 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, most of the impact applied from the first layer side of the plywood is received by the first layer, and the amount of the dent of the first layer increases, so that the dent is concerned. Deteriorates the appearance. The thickness of the first layer is preferably 0.9 mm or less, more preferably 0.8 mm or less. The thickness of the first layer is preferably 0.3 mm or more, more preferably 0.5 mm or more, further preferably 0.6 mm or more, and may occur due to the difference in shrinkage between the first layer and the second layer. 0.7 mm or more is particularly preferable in order to avoid sexual cracking. When the thickness of the first layer is within the above range, slight irregularities such as knots, grain, cracks, and chips of the second layer are further suppressed from being visually recognized from the surface of the decorative material. The thickness range of the first layer is particularly preferably 0.6 mm or more and 0.9 mm or less.

The first layer preferably has no conspicuous knots on its surface, and more preferably has no knots. The smoothness of the surface of the plywood is further improved by making the knots on the surface of the first layer inconspicuous or having no knots. Further, even if the first layer has knots on the surface, it is preferable that the number of the first layer is smaller than that of the second layer.

(2nd layer)
As long as the specific gravity of the second layer is larger than the specific gravity of the first layer, the type of the tree is not limited. As the second layer, a eucalyptus veneer is preferable because it has a relatively high specific gravity.

The specific density of the second layer is larger than the specific gravity of the first layer. The specific gravity of the second layer is preferably 0.50 or more, more preferably 0.55 or more. The upper limit is preferably 0.90 or less, more preferably 0.75 or less, further preferably 0.65 or less, and particularly preferably less than 0.60. With the specific gravity in the above range, the plywood constituting the decorative material of the present invention exhibits even more excellent impact resistance and excellent machinability during processing. The range of the specific gravity of the second layer is particularly preferably 0.55 or more and less than 0.60.

The thickness of the second layer is not particularly limited, but 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 knots on at least a portion of the surface. Since the plywood has the first layer, even if the second layer has knots on at least a part of the surface, the projection on the surface of the plywood is suppressed and the projection on the surface of the decorative material is suppressed. Is also suppressed.

The layer structure of the plywood has at least a first layer and a second layer, and is not particularly limited as long as several veneers, which are thinly cut plywood logs, are bonded together. In the plywood, it is more preferable that the odd-numbered veneers are bonded so that the grain of wood is orthogonal to each other.

The plywood may have a layer structure having another woody layer as long as it has at least the first layer and the second layer in order from the top. In such a layer structure, the first layer is the outermost surface, the second layer is laminated under the first layer, and another wood layer is further laminated under the first layer to have an odd number of wood layers. The layer structure can be mentioned. As such a layer structure, for example, as in the plywood 1 of FIG. 1, a plywood having a first layer 11 / a second layer 12 / a third layer 13 / a fourth layer 14 / a fifth layer 15 in order from the top. Like the plywood 2 in FIG. 2, the plywood having the 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, and may be any number of layers, but 3 to 9 layers are preferable, and 5 to 7 layers are more preferable. Further, the number of wood layers of the plywood is preferably an odd number in that the warp of the plywood and the decorative material can be further suppressed.

The total thickness of the plywood is not particularly limited, and considering the ease of construction when used as an interior material, it is preferably 5.0 mm or more and 30.0 mm or less, and the lower limit is more preferably 5.5 mm or more. 5 mm or more and 9.0 mm or more are particularly preferable. The upper limit is more preferably 15.5 mm or less, further preferably 12.5 mm or less. The thickness is particularly preferably 9.0 mm or more and 12.5 mm or less. In this case, the number of layers of the wood layer is preferably 5 to 7, and particularly preferably 7 layers. Further, in the case of a thickness of about 15 mm, 9 layers are particularly preferable. The thickness of a general wood flooring material such as a flooring material for a living room or a corridor is usually about 8 mm, about 12 mm, about 15 mm, or the like. Further, when laminating the design layers described later, the total layer thickness including the design layer is generally about 8 mm, about 12 mm, and about 15 mm.

In the plywood 1 of FIG. 1, the same type of veneer of wood is used as the first layer 11 on the front surface called the so-called face and the fifth layer 15 on the back surface called the so-called back. The veneer of the same type of tree may be used for the second layer 12 to the fourth layer 14, or the veneer of the same type of tree as the first layer 11 and the fifth layer 15 may be used for the third layer 13. May be good. Further, it is preferable to use veneer of the same type of tree for the second layer 12 and the fourth layer 14. To exemplify such a specific layer structure of the plywood of FIG. 1, in order from the top, a layer structure having a poplar veneer / eucalyptus veneer / poplar veneer / eucalyptus veneer / poplar veneer / poplar veneer / Examples thereof include a layer structure having a eucalyptus veneer / eucalyptus veneer / eucalyptus veneer / poplar veneer.

In the plywood 2 of FIG. 2, the same type of wood veneer is used as the first layer 21 on the front surface called the so-called face and the seventh layer 27 on the back surface called the so-called back. The same type of tree veneer may be used as the second layer 22 to the sixth layer 26, but the same type of tree may be used as the first layer 21, the third layer 23, the fifth layer 25, and the seventh layer 27. It is preferable to use the veneer of. Further, it is preferable to use veneer of the same type of tree for the second layer 22, the fourth layer 24 and the sixth layer 26. As a specific layer structure of the plywood of FIG. 2, a layer having a poplar veneer / eucalyptus veneer / poplar veneer / eucalyptus veneer / poplar veneer / eucalyptus veneer / poplar veneer in order from the top. Composition and layer composition with poplar veneer / eucalyptus veneer / eucalyptus veneer / eucalyptus veneer / eucalyptus veneer / eucalyptus veneer / poplar veneer, poplar veneer / eucalyptus veneer / eucalyptus veneer / poplar veneer / A layer structure having a eucalyptus veneer / eucalyptus veneer / poplar veneer can be 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.

FIG. 3 shows an example of the decorative material. FIG. 3 is a two-view view showing an example of the decorative material of the present invention. The decorative material shown in FIG. 3 is formed by laminating the design layer 5 on the first layer 21 of the plywood 2. In the decorative material shown in FIG. 3, the plywood is subjected to sane (actual) processing, and the male sane A, which is a convex portion protruding toward the upper side of the paper surface, and the concave portion formed on the lower side of the paper surface. Has a female plywood B. The decorative material shown in FIG. 3 is further suitable as a floor decorative material because it can be sewn together by fitting the male sane A and the female sane B by applying the sane processing. Can be used for.

Hereinafter, the design layer will be described.

In the decorative material of the present invention, the design layer is a decorative sheet made of synthetic resin. In the present specification, the synthetic resin decorative sheet is a decorative sheet in which most of the layers constituting the decorative sheet are made of synthetic resin, and includes a thermoplastic resin and a thermosetting resin, and has a surface as described later. A part of the layer such as the protective layer may contain an inorganic filler other than the synthetic resin and an additive such as an organic substance.

The total thickness of the design layer is 0.20 mm or more. If the total thickness of the design layer is less than 0.20 mm, the decorative material is inferior in impact resistance. The total thickness of the design layer is preferably 0.25 mm or more, more preferably 0.30 mm or more. When the lower limit of the total thickness of the design layer is within the above range, the impact resistance of the decorative material is further improved. The total thickness of the design layer is 0.70 mm or less. If the total thickness of the design layer exceeds 0.70 mm, the decorative material may be warped. The total thickness of the design layer is preferably 0.6 mm or less, more preferably 0.45 mm or less. When the upper limit of the total thickness of the design layer is within the above range, the warp of the decorative material can be further suppressed. It should be noted that 0.25 mm or more and 0.45 mm or less are particularly preferable.

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

The configuration of the synthetic resin decorative sheet is not particularly limited, and for example, one having 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 in this order is preferable. .. Further, a material having a base sheet, a pattern layer (solid ink layer / pattern ink layer), and a surface protection layer in this order can also be used. Further, as in the synthetic resin decorative sheet 6 (a) of FIG. 4 (a) and the synthetic resin decorative sheet 6 (b) of FIG. 4 (b), the base sheet 612 is placed on the synthetic resin backer layer 611. , A pattern layer (solid ink layer / pattern ink layer) 613, a transparent adhesive layer (not shown), a transparent resin layer 614, and a surface protection layer 615 are also preferable. Hereinafter, this design layer will be described as an example. The synthetic resin backer layer is made of synthetic resin, which is laminated so as to be located on the back surface side of the design layer, alleviates the influence of surface irregularities such as a wooden base material, and imparts impact resistance to the design layer itself. It is a layer and constitutes a part of the design layer.

(Base sheet)
Examples of the base material sheet include one or more laminated bodies of synthetic resin sheets such as polyolefin, polyester, polyacrylic acid, polyamide, polyurethane, and polystyrene.

The thickness of the base sheet is preferably about 20 to 300 μm. The base sheet may be colored if necessary. Further, the surface may be subjected to surface treatment such as corona discharge treatment, plasma treatment, ozone treatment, etc., or may be coated with a primer which is a base paint for enhancing adhesion with an adjacent layer.

(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 grain pattern, a cloth pattern, a leather pattern, a geometric pattern, characters, symbols, line drawings, and various abstract patterns. The solid ink layer is obtained by solid printing of colored ink. The pattern layer is composed of one or both of the pattern ink layer and the solid ink layer.

The ink used for the pattern layer includes chlorinated polyethylene such as chlorinated polyethylene and chlorinated polypropylene, polyester, polyurethane composed of isocyanate and polyol, polyacrylic, polyvinyl acetate, polyvinyl chloride, and vinyl chloride-vinyl acetate as vehicles. A polymer, a cellulose-based resin, a polyamide-based resin, or the like may be used alone or in combination of two or more, and a pigment, a solvent, various auxiliary agents, or the like may be added to the mixture to form an ink. Among these, one or a mixture of two or more of polyester, polyurethane composed of isocyanate and polyol, polyacrylic acid, polyamide-based resin, etc. is preferable from the viewpoint of environmental problems, adhesion to the printed surface, and the like.

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

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

(Transparent resin layer)
The transparent resin layer is not particularly limited as long as it is a transparent resin layer, and can be suitably formed by, for example, a transparent thermoplastic resin.

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

The transparent resin layer may be colored. In this case, a colorant may be added to the thermoplastic resin. As the colorant, a pigment or dye used in the pattern layer can be used.

The transparent resin layer includes a filler, a matting agent, a foaming agent, a flame retardant, a lubricant, an antistatic agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a radical scavenger, and a soft component (for example, rubber). Various additives such as may be included.

(Surface protective layer)
The surface protective layer (transparent surface protective layer) is provided to impart surface physical properties such as scratch resistance, wear resistance, water resistance, and stain resistance required for the design layer. The resin forming the surface protective layer preferably contains at least one type of curable resin such as a thermosetting resin or an ionizing radiation curable resin. In particular, the ionizing radiation curable resin is preferable from the viewpoint of high surface hardness, productivity and the like. Further, the electron beam curable resin is most preferable from the viewpoint of further improving the weather resistance.

Examples of the thermosetting resin include unsaturated polyester resin, polyurethane resin (including two-component curable polyurethane), epoxy resin, aminoalkyd resin, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, and melamine. -Urea cocondensation resin, silicon resin, polysiloxane resin and the like can be mentioned.

A curing agent such as a cross-linking agent and a polymerization initiator, and a polymerization accelerator can be added to the resin. For example, as a curing agent, isocyanate, organic sulfonate, etc. can be added to unsaturated polyester resin, polyurethane resin, etc., organic amine, etc. can be added to epoxy resin, peroxide such as methyl ethyl ketone peroxide, azoisobutylnitrile, etc. A radical initiator can be added to the unsaturated polyester resin.

Examples of the method of forming the surface protective layer with the thermosetting resin include a method of applying a solution of the thermosetting resin by a coating method such as a roll coating method and a gravure coating method, and drying and curing the solution. The amount of the solution applied is approximately 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 cross-linking polymerization reaction by irradiation with ionizing radiation and changes into a three-dimensional polymer structure. For example, one or more of prepolymers, oligomers and monomers having a polymerizable unsaturated bond or an epoxy group in the molecule that can be crosslinked by irradiation with ionizing radiation can be used. For example, acrylate resins such as urethane acrylates, polyester acrylates and epoxy acrylates; silicon resins such as siloxane; polyester resins; epoxy resins and the like can be mentioned.

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

As the ultraviolet source, a light source of 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 rays is about 190 to 380 nm.

As the electron beam source, for example, various electron beam accelerators such as cockcroftwald type, van de Graaff type, resonance transformer type, insulated core transformer type, linear type, dynamistron type, and 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 by irradiating it with an electron beam, but when it is cured by irradiating it with ultraviolet rays, it is preferable to add a photopolymerization initiator (sensitizer).

In the case of a resin system having a radically polymerizable unsaturated group, the photopolymerization initiator is, for example, acetophenone, benzophenone, thioxanthone, benzoin, benzoin methyl ether, Michler benzoyl benzoate, 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 cationically polymerizable functional group, for example, at least one of an aromatic diazonium salt, an aromatic sulfonium salt, a metallocene compound, a benzoin sulfonic acid ester, a freeleoxysulfoxonium diallyl iodosyl salt and the like. Can be used.

The amount of the photopolymerization initiator added is not particularly limited, but is generally about 0.1 to 10 parts by mass with respect to 100 parts by mass of the ionizing radiation curable resin.

As a method for forming the protective layer with the ionizing radiation curable resin, for example, a solution of the ionizing radiation curable resin may be applied by a coating method such as a gravure coating method or a roll coating method. The amount of the solution applied is approximately 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 of the ionizing radiation curable resin, an inorganic filler may be blended. Examples of the inorganic filler include powdered aluminum oxide, silicon carbide, silicon dioxide, calcium titanate, barium titanate, magnesium pyrobolate, zinc oxide, silicon nitride, zirconium oxide, chromium oxide, iron oxide, and boron nitride. Examples thereof include diamond, Kongo sand, and glass fiber.

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

(Synthetic resin backer layer)
As shown in FIGS. 4 (a) and 4 (b), the synthetic resin decorative sheet is synthesized on the bottom 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 backer layer made of synthetic resin, 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, polyethylene, polymethylpentene, polyethylene terephthalate, and highly 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 terephthalate, polyethylene naphthalate-isophthalate copolymer, Examples thereof include amorphous polyester (A-PET), polycarbonate, polyarylate, polyimide, polystyrene, polyamide, ABS and the like. These resins can be used alone or in combination of two or more.

The Martens hardness of the synthetic resin backer layer is preferably 20 to 350 N / mm ² , more preferably 50 to 300 N / mm ² , further preferably 50 to 250 N / mm ² , and particularly preferably 75 to 250 N / mm ² . 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. Further, 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 the present specification, the Martens hardness is a value measured using a surface film physical property tester (PICODETOR HM-500, manufactured by Fisher Instruments Co., Ltd.), and a specific measuring method is as follows. ..

In this measuring method, the diamond indenter (Vickers indenter) shown in FIG. 5 (a) is used to push the diamond indenter into the measurement sample as shown in FIG. 5 (b) to form a pyramid-shaped depression h on the surface. 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).

As the pushing condition, at room temperature (laboratory environment temperature), as shown in the image diagram shown in FIG. 5 (c), a load of 0 to 5 mN was first applied for 10 seconds, and then a load of 5 mN was held for 5 seconds. Finally, unloading from 5 to 0 mN is performed in 10 seconds. The hardness obtained by F / A based on the surface area A and the test load F is the Martens hardness.

In this specification, the Martens hardness of the cross section of the synthetic resin backer layer was measured in order to avoid the influence of the hardness of the layers other than the synthetic resin backer layer. At this time, a synthetic resin decorative sheet is embedded in a resin (cold-curing type epoxy two-component curing resin), left at room temperature for 24 hours or more to cure, 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, and the like.

The thickness of the synthetic resin backer layer is preferably 0.10 to 0.60 mm, more preferably 0.13 or more and 0.15 or more as the lower limit, and more preferably 0.45 or less and 0.30 or less as the upper limit. It is more preferably 0.25 or less and 0.20 or less. 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. Further, when the upper limit of the thickness of the synthetic resin backer layer is within the above range, the warp of the decorative material of the present invention is further suppressed. In addition, 0.13 to 0.25 is a particularly preferable range.

For laminating each layer, for example, a pattern layer (solid ink layer, pattern ink layer) is formed by printing on one surface of the base sheet, and then a transparent resin is laminated on the pattern layer by a T-die extrusion method or the like. A transparent resin layer is laminated by a dry lamination method via a known dry lamination adhesive such as a two-component curable urethane resin, and a surface protective layer is further formed to prepare a design layer intermediate, and T-die extrusion is performed. This can be done by laminating the synthetic resin layer backer layer produced by the method or the like and the design layer intermediate by thermal laminating.

As shown in FIG. 4, the synthetic resin decorative sheet may be embossed from the transparent resin layer side or the surface protection layer side to form an uneven pattern. The uneven pattern can be formed by a 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 perforated groove.

Since the decorative material of the present invention has the above-mentioned structure, it is excellent in impact resistance, warpage and visibility of plywood surface defects from the design layer surface are suppressed, and it is excellent in designability.

2. 2. Method for Producing Decorative Material The method for producing the decorative material is not particularly limited, and the decorative material can be produced by a conventionally known method. Examples of the manufacturing method include a manufacturing method including a step of laminating a design layer on a first layer of plywood.

The method of laminating the design layer on the first layer of the plywood is not particularly limited, and examples thereof include a method of laminating these layers via an adhesive layer. Examples of the adhesive forming the adhesive layer include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, urethane, acrylic, urethane / acrylic, urethane / acrylic copolymer, and ethylene / acrylic acid. Examples thereof include water-soluble emulsion-based and solvent-based adhesives containing polymers, ionomers, butadiene / acrylic nitrile rubbers, neoprene rubbers, natural rubbers and the like as active ingredients, and reactive hot melt-based adhesives exemplified for PUR. Among these, a water-soluble emulsion adhesive and a reactive hot melt adhesive are preferable from the viewpoint of workability, and a reactive hot melt adhesive is more preferable from the viewpoint of excellent appearance after the laminating step. Examples of the curing method of the adhesive include one-component curing, two-component curing, thermosetting, moisture curing, and ionizing radiation curing such as electron beam and ultraviolet rays. The thickness of the adhesive layer is not limited, but is preferably about 0.1 to 50 μm.

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

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

(Step 1)
Step 1 is a step of laminating the first layer and the second layer. The first layer, the second layer, and their thickness and specific density are the same as those described in the above plywood.

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

When the plywood has a first layer, a second layer, and other woody layers as shown in FIGS. 1 and 2, an adhesive is applied between the layers of each layer and laminated, and the plywood is laminated by the above-mentioned thermal pressure press. Just do it. The adhesive used between the layers is not shown in FIGS. 1 and 2 and is omitted. Further, the adhesive layer formed by the adhesive is not included in the layers such as the first layer to the seventh layer forming the plywood described above.

The adhesive is not particularly limited, and known woodworking adhesives can be widely used. As the adhesive, for example, polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ionomer, butadiene-acrylic nitrile rubber, neoprene rubber, natural rubber and the like are used as active ingredients. Adhesive to be used. Further, examples of the thermosetting adhesive include melamine-based, phenol-based, and urea-based (vinyl acetate-urea-based, etc.) adhesives.

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

(Step 2)
Step 2 is a step of polishing the surface of the first layer after step 1 to adjust 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 planer, a buff, a brush, or the like. Above all, the 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 preferably about 0.8 to 1.3 mm.

In step 2, the surface of the first layer may be polished, and the wood layer on the surface opposite to the surface on which the first layer of the produced plywood is laminated may also be polished to adjust the thickness. 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. You may. Further, as shown in FIG. 2, when the plywood 2 has the 7th layer 27 on the opposite surface of the 1st layer 21, the surface of the 1st layer 21 is polished and the entire surface of the 7th layer 27 is polished. It may be polished for thickness adjustment or the like.

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

The plywood used as a decorative material can also be manufactured by the following manufacturing method.
A method for producing plywood having at least a first layer and a second layer in order from the top.
(I) A step of preparing a poplar veneer having an air-dry specific density of 0.40 or more and 0.47 or less as the first layer and a eucalyptus veneer having an air-dry specific density of 0.50 or more and 0.90 or less as the second layer. 1,
(II) Step 2 of laminating the first layer and the second layer, and
(III) A method for producing plywood, which comprises a step 3 of polishing the surface of the first layer after the step 2 to adjust the thickness of the first layer to less than 1.0 mm. The manufacturing method is referred to as manufacturing method 2.

In step 1 of the manufacturing method 2, a poplar veneer having an air-dry specific density of 0.40 or more and 0.47 or less is prepared as the first layer, and a eucalyptus veneer having an air-dry specific density of 0.50 or more and 0.90 or less is prepared as the second layer. It is a process to do. In the production method 2, the first layer and the second layer having the air-dry specific gravity in the above range are prepared and subjected to the step 2 described below.

Steps 2 and 3 in the manufacturing method 2 are the same as steps 1 and 2 in the manufacturing method 1 described above, except that the first layer and the second layer having the air-dry specific density in the above range prepared in the above step 1 are used. Is. In the production method 2, a poplar veneer having an air-dry specific density of 0.40 or more and 0.47 or less is used for the first layer, and a eucalyptus veneer having an air-dry specific density of 0.50 or more and 0.90 or less is used for the second layer. , It is possible to manufacture plywood having excellent impact resistance.

In the present specification, the air-dry specific gravity means the specific gravity calculated by dividing the weight of the wood in the air-dry state by its volume, and the air-dry state means that the water content is 15%. It is the state of the wood at that time.

By the manufacturing method 2 described above, the plywood used for the decorative material of the present 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 densities of each layer were measured from the produced plywood and found to be as follows.
Poplar veneer: 0.43
Eucalyptus veneer: 0.55

Example 1
(Making plywood)
As the first layer, a poplar veneer having a thickness of 1.3 mm and a specific density of 0.43 was prepared by slicing poplar. Further, 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. Further, the same poplar veneer as the first layer was prepared as the third layer, the fifth layer, and the seventh layer, and the same eucalyptus veneer as the second layer was prepared as the fourth layer and the sixth layer. The prepared poplar veneer and eucalyptus veneer are placed in order from the top to the first to seventh layers via a urea-based adhesive so that the grain directions of the adjacent wood layers are orthogonal to each other. A laminated wood layer was prepared by laminating so as to have a layer structure of poplar veneer / eucalyptus veneer / poplar veneer / eucalyptus veneer / poplar veneer.

The laminated body of the wood layer was hot-pressed for 5 minutes under the conditions of a pressure of 0.78 MPa and a temperature of 110 ° C. using a multi-stage hot press machine, and the layers were bonded together. By hot pressure pressing, the thickness of the poplar veneer was 1.2 mm, the thickness of the eucalyptus veneer was 2.5 mm, and the total thickness of the laminated body 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, the thickness of each of 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 the seventh layer is sanded and polished. By adjusting the thickness, a plywood having a total thickness of 11.5 mm was produced.

(Making synthetic resin decorative sheet)
Urethane cellulosic resin (100 parts by weight of a mixture of urethane and nitrified cotton with 5 parts by weight of hexamethylene diisocyanate added) is applied to one side of a 60 μm thick colored polypropylene film treated with double-sided corona discharge by a gravure coating method. , A backside primer layer was formed. The backside primer layer was 1 μm.

Next, a solid ink layer and a pattern ink layer were sequentially formed by gravure printing using a printing ink using an acrylic urethane resin (100 parts by weight of acrylic polyol plus 5 parts by weight of hexamethylene diisocyanate) as a binder, and wood grain and abstract. An ink layer of the pattern was formed. The ink layer was 3 μm.

Next, a urethane-based adhesive was applied onto the pattern layer, and then a propylene-based resin was heated, melted and extruded from above with a T-die extruder so as to have a thickness of 80 μm to form a transparent resin layer.

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

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

Subsequently, embossing is performed from the surface protective layer side with a wood grain conduit-like embossed plate or a wood surface / abstract-like embossed plate having a plate depth of 50 μm to form a wood grain conduit-like or wood surface / abstract-like uneven pattern, and the thickness is 0.16 mm. Obtained the design layer intermediate.

A synthetic resin sheet (synthetic resin backer layer) was formed by co-extruding A-PET (amorphous polyester) 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 urethane-based adhesive layer was further interposed in the back surface primer layer of the design layer intermediate, and a synthetic resin backer layer was laminated by a dry laminating method to prepare a synthetic resin decorative sheet which is a design layer. The thickness of the synthetic resin decorative sheet was 0.41 mm. The synthetic resin decorative sheet is referred to as a decorative sheet (1).

(Making decorative material)
The surface of the synthetic resin decorative sheet on the backer layer side and the surface of the plywood on the first layer side are bonded together via a reactive hot melt adhesive (PUR) adhesive (thickness 50 μm), and have predetermined dimensions. A decorative material was prepared by cutting into (145 mm × 900 mm).

Example 2
The types and thicknesses of the trees in the first and second layers of plywood are as shown in Table 1, and the same veneers as in Example 1 are laminated as the third to seventh layers. That is, each layer from the first layer to the seventh layer is laminated by using the same manufacturing method as in Example 1 above, and the thickness is adjusted to make the poplar veneer 0.8 mm / eucalyptus veneer 2.5 mm /. Poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm / poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm, and the thickness is adjusted by sanding and polishing the poplar veneer as the 7th layer to plywood. The total thickness of was 11.5 mm. A decorative material was produced in the same manner as in Example 1 except for the above.

Example 3
The types and thicknesses of the trees in the first and second layers of plywood are as shown in Table 1, and the same veneers as in Example 1 are laminated as the third to seventh layers. That is, each layer from the first layer to the seventh layer is laminated by using the same manufacturing method as in Example 1 above, and the thickness is adjusted, so that the poplar veneer 0.6 mm / eucalyptus veneer 2.5 mm / Poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm / poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm, and the thickness is adjusted by sanding and polishing the poplar veneer as the 7th layer to plywood. The total thickness of was 11.5 mm. A decorative material was produced in the same manner as in Example 1 except for the above.

Example 4
The thickness of the transparent resin layer was changed to 60 μm, and the thickness of the synthetic resin backer layer was changed to 0.20 mm. As an exception, a synthetic resin decorative sheet was prepared in the same manner as in Example 1. The synthetic resin decorative sheet is referred to as a decorative sheet (2). A decorative material was produced in the same manner as in Example 3 except that the decorative sheet (2) was used instead of the decorative sheet (1).

Example 5
The thickness of the transparent resin layer was 60 μm, and 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 0.13 mm, and the Martens hardness was 160 N / mm ² . A decorative sheet made of synthetic resin was prepared in the same manner as in Example 1 except for the above. The synthetic resin decorative sheet is referred to as a decorative sheet (3). A decorative material was produced in the same manner as in Example 3 except that the decorative sheet (3) was used instead of the decorative sheet (1).

Example 6
As the first layer, a poplar veneer having a thickness of 1.3 mm and a specific density of 0.43 was prepared by slicing poplar. Further, as the second layer, a eucalyptus veneer having a thickness of 2.2 mm and a specific density of 0.55 was prepared by slicing eucalyptus. Further, the same poplar veneer as the first layer was prepared as the seventh layer, and the same eucalyptus veneer as the second layer was prepared as the third to sixth layers. The prepared poplar veneer and eucalyptus veneer are arranged so that the grain direction of the adjacent wood layer is orthogonal to each other, and the poplar veneer / eucalyptus veneer is sequentially applied from the first layer to the seventh layer via a urea-based adhesive. / Veneer of eucalyptus / Veneer of eucalyptus / Veneer of eucalyptus / Veneer of eucalyptus / Veneer of poplar was laminated to prepare a laminated wood layer.

The laminated body of the wood layer was hot-pressed for 5 minutes under the conditions of a pressure of 0.78 MPa and a temperature of 110 ° C. using a multi-stage hot press machine, and the layers were bonded together. By hot pressure pressing, the thickness of the poplar veneer was 1.2 mm, the thickness of the eucalyptus veneer was 2.0 mm, and the total thickness of the laminated body was 12.4 mm.

The first layer and the seventh layer were sanded and polished so that the thickness of the first layer was 0.8 mm and the total thickness of the plywood was 11.5 mm. That is, the thickness of each of the first layer to the sixth layer is 0.8 mm / 2.0 mm / 2.0 mm / 2.0 mm / 2.0 mm / 2.0 mm, and the seventh layer is sanded and polished. By adjusting the thickness, a plywood having a total thickness of 11.5 mm was produced. A decorative material was produced in the same manner as in Example 2 except for the above.

Example 7
(Making plywood)
As the first layer of plywood, a poplar veneer having a thickness of 1.4 mm and a specific density of 0.43 was prepared by slicing poplar. Further, as the second layer, a eucalyptus veneer having a thickness of 2.7 mm and a specific density of 0.55 was prepared by slicing eucalyptus. Further, the same poplar veneer as the first layer was prepared as the third layer, the fifth layer, and the seventh layer, and the same eucalyptus veneer as the second layer was prepared as the fourth layer and the sixth layer. The prepared poplar veneer and eucalyptus veneer are arranged so that the grain direction of the adjacent wood layer is orthogonal to each other, and the poplar veneer / eucalyptus veneer is sequentially applied from the first layer to the seventh layer via a urea-based adhesive. / Poplar veneer / Eucalyptus veneer / Poplar veneer / Eucalyptus veneer / Poplar veneer were laminated to prepare a laminated wood layer.

The laminated body of the wood layer was hot-pressed for 5 minutes under the conditions of a pressure of 0.78 MPa and a temperature of 110 ° C. using a multi-stage hot press machine, and the layers were bonded together. By hot pressure pressing, the thickness of the poplar veneer was 1.3 mm, the thickness of the eucalyptus veneer was 2.5 mm, and the total thickness of the laminated body was 12.7 mm.

Table 1 shows the types and thicknesses of the trees in the first and second layers of plywood. That is, each layer from the first layer to the seventh layer is made of poplar veneer 0.3 mm / eucalyptus veneer 2.5 mm / poplar veneer 1.3 mm / eucalyptus veneer 2.5 mm / poplar veneer 1.3 mm. / The eucalyptus veneer was 2.5 mm, and the thickness of the poplar veneer as the seventh layer was adjusted by sanding to make the total thickness of the plywood 11.5 mm. A decorative material was produced in the same manner as in Example 1 except for the above.

Example 8
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 . As an exception to this, a synthetic resin decorative sheet, which is a design layer, was prepared in the same manner as in Example 1. The synthetic resin decorative sheet is referred to as a decorative sheet (4).

A decorative material was produced in the same manner as in Example 1 except that the decorative sheet (4) was used instead of the decorative sheet (1).

Example 9
As the first layer of plywood, a poplar veneer having a thickness of 3.5 mm and a specific density of 0.43 was prepared by slicing poplar. Further, as the second layer, a eucalyptus veneer having a thickness of 3.5 mm and a specific density of 0.55 was prepared by slicing eucalyptus. Further, the same poplar veneer as the first layer was prepared as the third layer and the fifth layer, and the same eucalyptus veneer as the second layer was prepared as the fourth layer. The prepared poplar veneer and eucalyptus veneer are placed in order from the top to the first to fifth layers via a urea-based adhesive so that the grain directions of the adjacent wood layers are orthogonal to each other. / Poplar veneer / Eucalyptus veneer / Poplar veneer were laminated so as to have a layer structure, and a laminated wood layer was prepared.

The laminated body of the wood layer was hot-pressed for 5 minutes under the conditions of a pressure of 0.78 MPa and a temperature of 110 ° C. using a multi-stage hot press machine, and the layers were bonded together. By hot pressure pressing, the thickness of the poplar veneer was 3.2 mm, the thickness of the eucalyptus veneer was 3.2 mm, and the total thickness of the laminated body was 16.0 mm.

The number of plywood layers was 5, and the types and thicknesses of the trees in the first and second layers 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 of the poplar veneer was adjusted by sanding and polishing to make the total thickness of the plywood 11.5 mm. A decorative material was produced in the same manner as in Example 1 except for the above.

Example 10
The adhesive used to bond the surface of the synthetic resin decorative sheet on the backer layer side and the surface of the plywood on the first layer side was changed to a water-soluble emulsion adhesive, and the coating thickness was 35 μm. A decorative material was produced in the same manner as in Example 5 except that. 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-based curing agent: "BA-11B" manufactured by Japan Coating Resin Co., Ltd., Isocyanate-based compounding ratio: Main agent: Hardener = 100: 2.5 (mass ratio)

Example 11
The types and thicknesses of the trees in the first layer and the second layer were set as shown in Table 1, and the same veneers as in Example 1 were laminated as the third to seventh layers. That is, each layer from the first layer to the seventh layer is laminated by using the same manufacturing method as in Example 1 above, and the thickness is adjusted to adjust the thickness of the Falcata veneer 0.6 mm / eucalyptus veneer 2.5 mm /. Poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm / poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm, and the thickness is adjusted by sanding and polishing the poplar veneer as the 7th layer to plywood. The total thickness of was 11.5 mm. A decorative material was produced in the same manner as in Example 1 except for the above.

Example 12
As the first layer, a poplar veneer having a thickness of 1.3 mm and a specific density of 0.43 was prepared by slicing poplar. Further, as the second layer, a eucalyptus veneer having a thickness of 2.1 mm and a specific density of 0.55 was prepared by slicing eucalyptus. Further, the same poplar veneer as the first layer was prepared as the ninth layer, and the same eucalyptus veneer as the second layer was prepared as the third to eighth layers. The prepared poplar veneer and eucalyptus veneer are arranged so that the grain direction of the adjacent wood layer is orthogonal to each other, and the poplar veneer / eucalyptus veneer is sequentially applied from the first layer to the ninth layer via a urea-based adhesive. / Veneer eucalyptus / Veneer eucalyptus / Veneer eucalyptus / Veneer eucalyptus / Veneer eucalyptus / Veneer eucalyptus / Veneer poplar were laminated to prepare a laminated wood layer.

The laminated body of the wood layer was hot-pressed for 5 minutes under the conditions of a pressure of 0.78 MPa and a temperature of 110 ° C. using a multi-stage hot press machine, and the layers were bonded together. By hot pressure pressing, the thickness of the poplar veneer was 1.2 mm, the thickness of the eucalyptus veneer was 1.9 mm, and the total thickness of the laminated body was 15.7 mm.

The first layer and the ninth layer were sanded and polished so that the thickness of the first layer was 0.6 mm and the total thickness of the plywood was 14.5 mm. That is, the thicknesses of the first layer to the eighth layer are 0.6 mm / 1.9 mm / 1.9 mm / 1.9 mm / 1.9 mm / 1.9 mm / 1.9 mm / 1.9 mm, respectively. The thickness of the 9 layers was adjusted by sanding and polishing to prepare a plywood having a total thickness of 14.5 mm. A decorative material was produced in the same manner as in Example 4 except for the above.

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

(Making decorative material)
As a design layer, a veneer made of oak with a thickness of 0.20 mm was prepared. The veneer and the surface of the plywood on the first layer side were bonded together via a thermosetting vinyl acetate / urea adhesive.

Next, urethane acrylate-based ultraviolet curable paint ("Aurex No. 811", manufactured by Chugoku Paint Co., Ltd.) was applied to the surface of the veneer three times in the order of natural roll coating method, reverse roll coating method, and natural roll coating method. An undercoat layer composed of a coating film of 10 g / m ² was formed. Immediately, the undercoat layer was cured by irradiating it with ultraviolet rays in the air with an electrodeized ultraviolet lamp.

Next, an intermediate layer composed of a coating film of 12 g / m ² was formed on the cured undercoat layer by a natural roll coating method. Immediately, the intermediate layer was cured by irradiating it with ultraviolet rays in the air with an electrodeized ultraviolet lamp. The surface of the cured intermediate layer was polished with No. 360 polishing paper, and the powder generated during polishing was removed.

Next, a topcoat layer composed of a coating film of 10 g / m ² was formed on the surface of the cured intermediate layer by a natural roll coating method. In a nitrogen gas atmosphere having an oxygen concentration of 0.5%, the topcoat layer was irradiated with ultraviolet rays with an electrodeless ultraviolet lamp and cured to form a surface protective layer. A decorative material was produced by cutting to a predetermined size (145 mm × 900 mm). The thickness of the surface protective layer was 30 μm.

Comparative Example 2
The types and thicknesses of the trees in the first layer and the second layer were set as shown in Table 1, and the same veneers as in Example 1 were laminated as the third to seventh layers. That is, each layer from the first layer to the seventh woody layer was laminated by using the same manufacturing method as in Example 1 above, and the thickness was adjusted, so that the poplar veneer 1.2 mm / poplar veneer 2. 5 mm / poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm / poplar veneer 1.2 mm / eucalyptus veneer 2.5 mm, and the thickness is adjusted by sanding and polishing the poplar veneer as the 7th layer. , The total thickness of the veneer was 11.5 mm. A decorative material was produced in the same manner as in Example 1 except for the above.

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

(1) Impact resistance test (DuPont impact test)
Cosmetic materials obtained in Examples and Comparative Examples according to the DuPont impact test described in "JISK5600-5-3 (1999) General paint test method Mechanical properties of coating film-Section 3: Weight drop resistance DuPont type". A shooting mold having a hemispherical tip with a radius of 6.35 mm was allowed to stand on the surface of the shooting mold, and a weight of 500 g was dropped on the shooting mold from a height of 300 mm. The amount of dent was measured with a measuring instrument (Ozaki Seisakusho Co., Ltd. T2-127) as shown in FIG.

(2) Repeated cold heat test Prepare a decorative material with a width of 145 mm and a length of 300 mm, let it stand on the base, and set "leave it at 80 ° C for 2 hours and then leave it at -20 ° C for 2 hours" as one cycle. , The cycle was repeated 10 cycles. Then, the amount of warpage and the appearance were evaluated by the following procedure.
If it is not possible to prepare a decorative material of the above size, use a decorative material with a similar shape when viewed in a plan view as much as possible, and perform evaluation by correcting the following evaluation criteria based on the size of the decorative material. It shall be.

(I) Evaluation of Warpage Amount As shown in FIG. 7, the maximum amount of warpage near the midpoint (150 mm) of the length of the decorative material was measured and evaluated according to the following evaluation criteria. In addition, in FIG. 7, FIG. 7 (a) shows the state before the test between the base 3 and the decorative material having the design layer 5 on the plywood 4, and FIGS. 7 (b) and 7 (c) show repeated cold heat. The base 3 and the decorative material after the test are shown, and d indicates the amount of warpage. When the state of FIG. 7 (c) is warped, as shown in FIG. 7 (d), the decorative material may be placed upside down on the base 3 and placed again, and the warp amount d may be measured. In addition, if the evaluation is B or higher in this test, it is 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 C: 1 mm or more

(Ii) Appearance evaluation The occurrence of appearance defects (projection of nodes in the second layer, agglutination cracks in the first layer) due to plywood on the surface of the decorative material was visually observed and evaluated according to the following evaluation criteria. As shown in FIG. 8, the agglutinated cracks in the first layer are cracks 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. Is. Further, if the evaluation is B or higher in this test, it can be evaluated that there is no problem in actual use.
A: Poor appearance cannot be confirmed B: Poor appearance can be confirmed but minor C: Poor appearance can be clearly confirmed

(3) Weather resistance test For the decorative materials of Examples 1 and 11 and Comparative Example 1, a sunshine weather meter: WEL-300 (manufactured by Suga Test Instruments Co., Ltd.) was used, and the design layer side of the decorative material was used under the following conditions. The appearance state when irradiated with sunshine carbon arc light for 1000 hours was visually evaluated. In addition, one cycle of step 1 → step 2 was set to 2 hours, and after one cycle, the test was repeated such as step 1 of the second cycle.
<Step 1>
・ Black panel temperature: 63 ° C, humidity: 50%
・ Operating time: 1 hour 42 minutes <Step 2>
-Tank temperature: 40 ° C, humidity: 90%
・ Driving time: 18 minutes

(4) Appearance Evaluation After Laminating The appearance of the synthetic resin decorative sheet and the surface of the plywood on the first layer side was visually observed via the adhesive shown in Table 1 and described below. It was evaluated according to the evaluation criteria. The surface of the synthetic resin decorative sheet on the backer layer side and the surface of the plywood on the first layer side were bonded together. Further, if the evaluation is B or higher in this test, it can be evaluated that there is no problem in actual use.
A: No appearance defects are seen and the appearance is good. B: Plywood defects such as plywood grain are not noticeable although they can be seen carefully. C: Plywood defects such as plywood grain can be clearly confirmed.

(5) Pencil hardness test The scratch resistance performance of each decorative material was evaluated using a pencil hardness tester. The test was conducted in accordance with JIS K5600-5-4 (1999), except that the tester was set to apply a load of 750 g to the tip of the pencil when the tester was in the horizontal position. Specifically, tests were conducted using pencils having HB and H cores in order from the one with the softest core hardness, and evaluation was performed according to the following evaluation criteria. If the evaluation is B or higher in this test, it can be evaluated that there is no problem in actual use.
A: No scratches occur when tested with a pencil with a hardness core of H B: No scratches occur even when tested with a pencil with a core with HB hardness, but a core with H hardness Scratches occur when testing with a pencil with C: HB hardness core Scratches occur when testing with a pencil

The results are shown in Table 1.

Reference example 1
The same plywood as the plywood used in Example 1 was prepared and used as the plywood of Reference Example 1.

Reference example 2
The same plywood as the plywood used in Example 2 was prepared and used as the plywood of Reference Example 2.

Reference example 3
The same plywood as the plywood used in Example 3 was prepared and used as the plywood of Reference Example 3.

Reference example 4
The same plywood as the plywood used in Example 7 was prepared and used as the plywood of Reference Example 4.

Reference example 5
The same plywood as the plywood used in Comparative Example 2 was prepared and used as the plywood of Reference Example 5.

Reference example 6
The same plywood as the plywood used in Example 9 was prepared and used as the plywood of Reference Example 6.

Reference example 7
The same plywood as the plywood used in Example 11 was prepared and used as the plywood of Reference Example 7.

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

The results are shown in Table 2.

1,2,4. Plywood 11,21. First layer 12,22. Second layer 13,23. Third layer 14,24. Fourth layer 15,25. Layer 5 111. Crack 211. First layer 221 with reduced thickness. Second layer with reduced thickness 26. Layer 6 27. Layer 7 3. 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. Amount of warp h. Pyramid-shaped depression m. Measuring instrument A. Male Sane B. Female sane

Claims (14)

A decorative material having a design layer on the first layer of plywood having at least the first layer and the second layer in order from the top.
(1) The first layer and the second layer are made of wood, and 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 larger than the specific gravity of the first layer.
(4) The design layer is a synthetic resin decorative sheet having a total thickness of 0.20 mm or more and 0.70 mm or less.
A decorative material characterized by that. The decorative material according to claim 1, wherein the synthetic resin decorative sheet has a thickness of 0.25 mm or more and 0.45 mm or less. The decorative material according to claim 1, wherein the synthetic resin decorative sheet has a synthetic resin backer layer on the plywood side. The decorative material according to claim 3, wherein the synthetic resin backer layer has a Martens hardness of 50 to 300 N / mm ² . The decorative material according to claim 1, wherein the surface layer of the synthetic resin decorative sheet is an ionizing radiation curable resin layer. The decorative material according to claim 5, wherein the synthetic resin decorative sheet is an electron beam curable resin layer in which the ionizing radiation curable resin layer is an electron beam curable resin layer. The decorative material according to claim 1, wherein the first layer is a poplar veneer and the second layer is a eucalyptus veneer. The decorative material according to claim 1, wherein the first layer is a Chinese poplar veneer. The decorative 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 decorative material according to claim 1, wherein the thickness of the first layer is 0.6 mm or more and 0.9 mm or less. The cosmetic according to claim 1, wherein the second layer has knots on at least a part of the surface on the side of the first layer, and the knots of the first layer are less than the knots of the second layer. Material. The decorative material according to claim 1, wherein the number of layers of the plywood is 5 or 7 layers. The decorative material according to claim 1, which is a decorative material for floors.

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