JPH0456725B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention aims to provide a natural wood decorative metal plate which can be bent and has excellent quality, with high production efficiency and economically. Conventionally, natural wood decorative boards have been widely used mainly in housing-related industries. These decorative boards are made by attaching a thin veneer of natural wood (hereinafter referred to as a board) to a wood base material such as plywood with an adhesive whose main component is a thermosetting resin.
It is produced using thermocompression bonding. Since these decorative boards are made of combustible material as a base material, there is always a risk of fire, and due to the characteristics of the base material, bending is impossible, so the design is unavoidably monotonous. If only to eliminate the risk of fire, the base material can be replaced with an inorganic material, but the base material is fragile and easily damaged.
Due to the characteristics of the base material, the weight increases, which poses great difficulties in transportation, construction, etc. An even more fundamental problem is that these also cannot be bent, so the design remains monotonous. Therefore, if a decorative board using a metal plate as the base material could be provided, the danger of fire would be eliminated. In addition, due to the characteristics of the base material, it can be bent and various curved surfaces can be obtained, dramatically improving the design. Furthermore, by making the metal plate thinner, it becomes possible to reduce the weight. Currently, a typical example of a decorative board based on a metal plate is a PVC steel plate with wood grain printed on the surface, but these lack a realistic feel and are not hygroscopic, so various problems such as condensation have been pointed out. There is. However, if we could provide a natural wood decorative metal plate, the precious wood itself would be the surface, giving it a real feel, and it would also have moisture absorption properties.
The problem of dew condensation is also alleviated, and a wide range of applications can be expected as a decorative board unlike any other. Therefore, while conventional natural wood decorative laminates were limited to applications mainly in the housing-related industry, their applications are expanding all at once, and they are now being used for decorative applications in new fields such as the vehicle industry such as automobiles and trains, and the ship and aircraft industries. It can also be used for boards. Furthermore, in the housing industry, if such decorative boards are used in high-rise buildings, etc., weight reduction can be achieved, and they are also useful in preventing fire accidents, so they are extremely useful. However, although such decorative laminates are desired in all fields, they have not been provided to the world mainly because they cannot be bent. In other words, simply gluing a plate and a metal plate together will cause cracks to occur at the bent portion of the plate surface during the bending process, making it impossible to obtain the surface beauty that is the lifeblood of a decorative plate, and due to this fatal defect. It was never possible to reach the stage where it could be put into practical use. However, in an attempt to obtain these decorative boards, for example, in Japanese Patent Publication No. 49-6086, a method was proposed in which a fibrous sheet was impregnated with an adhesive, a dried sheet adhesive was interposed between the adhesive board and the metal plate, and then heated and pressed. has been done. In these methods, the process of impregnation → drying → adhesion is extremely complicated, and since the adhesive is impregnated into the fibrous sheet and dried, it is heated and melted to adhere, which results in dotted adhesion, making it difficult to achieve reliable adhesion. Due to the lack of heat resistance, which is the essential drawback of heat melt bonding, there is a drawback that it lacks compatibility with the test method specified by the Japanese Agricultural Standards (hereinafter referred to as JAS method), leading to bonding uncertainty and quality problems. Since then, it has not yet been put into practical use. Therefore, in view of this current situation, the inventors of the present invention have developed a manufacturing method to obtain a natural wood decorative metal plate that has excellent quality as a decorative board, can be bent to meet multi-purpose uses, and is also economically efficient and economical. As a result of repeated research for multiple purposes, including selection of adhesives and examination of bonding methods, with the aim of establishing a method, the manufacturing method of the present invention was established, and the present invention was completed. The present invention consists of a natural wood decorative veneer, a porous sheet-like material, and a metal plate, and consists of an aqueous latex containing an aqueous dispersion of an acid group-containing polyurethane resin, and a crosslinking agent selected from an epoxy compound and an aziridine ring compound. A method for producing a natural wood-decorated metal plate, characterized in that it is crimped in an undried state using a water-based adhesive consisting of a combination of a water-based latex containing a hydroxyl group-containing water-soluble polymer and an isocyanate-based compound. Pertains to. In this case, the adhesive penetrates into the porous sheet-like material interposed between the natural wood decorative veneer and the metal plate during bonding, so that the three are integrated. When such a state is achieved, we discover that all of our intended objectives can be satisfied. That is, in the case of conventional plywood substrates, when an adhesive is applied, a phenomenon in which the adhesive is sucked into the plywood inevitably occurs, and as a result, when a porous sheet is placed in the middle as in the case of the present invention, The amount of adhesive that permeates into the porous sheet decreases, and the amount that permeates into the adhesive plate further decreases. Therefore, in this case, it is necessary to reapply the adhesive, which increases the number of steps, which is disadvantageous in terms of work and economy.
However, when a metal plate is used as the base material as in the present invention, the above-mentioned adhesive suction does not occur, and the adhesive applied on the metal plate permeates through the porous sheet material. In order to reach the mounting plate which is the surface material, use a specific adhesive as the adhesive, and complete the crimping while it is not dry.
The adhesive spreads over the entire surface of the bonded area, ensuring reliable bonding strength, and the above bonding process is performed with extremely simple operations of applying the adhesive and pressing, making it highly efficient and economically advantageous. be. Next, specific points for carrying out the present invention will be explained. Natural wood decorative veneer means a thin veneer of natural wood. Examples of the type include a thin veneer of precious wood, a board with plywood, or a thin veneer made by adhesively laminating precious wood called artificial heather and then slicing it. The porous sheet may be any material as long as it can be penetrated by the adhesive, and a typical example is a fibrous material. The types include organic substances such as natural polymers such as cellulose, semi-synthetic polymers such as viscose rayon, and synthetic polymers such as polyester, and inorganic substances such as glass fibers and asbestos. Examples include: In this case, they may be combined with each other. Specific materials include recycled paper such as paper waste, Japanese paper such as hanshi paper, shoji paper, western paper such as kraft paper, and nonwoven fabrics made using one or more of natural, semi-synthetic, and synthetic fibers. paper, glass wool paper, asbestos paper, etc. can be used. Among these, preferred are those in the form of coarse fibrous materials that are easily penetrated by the adhesive, such as recycled waste paper such as paper waste, Japanese paper, nonwoven fabric, and glass wool paper. Although the thickness of the sheet-like material is not particularly limited, it is necessary to select a thickness that allows the adhesive to penetrate throughout, since if the adhesive does not penetrate throughout, delamination will occur and the adhesive performance will deteriorate. Examples of the metal plate include steel plates such as steel plates, galvanized steel plates, and tin-coated steel plates, metal plates such as aluminum plates and copper plates, stainless steel plates, and metal plates made of alloys such as duralumin and brass. In this case, treatments such as surface treatment and resin coating may be applied to prevent corrosion. The adhesive used in the present invention is a combination of the following two, and has the following characteristics. A: A combination of an aqueous latex containing an aqueous dispersion of acid group-containing polyurethane resin and a crosslinking agent selected from epoxy compounds and aziridine ring compounds B: A combination of an aqueous latex containing a hydroxyl group-containing water-soluble polymer and an isocyanate compound (I) ) A has a urethane bond in its molecule, and B forms a urethane bond through a crosslinking reaction between a hydroxyl group and an isocyanate compound. Both of these materials have elastic properties as polymers with urethane bonds, and are effective in relieving stress during bending, contributing to the prevention of cracks at the bent portions of the plate surface. (b) Adhesion of metal plates is difficult, and adhesives are generally easy to peel off, but both A and B have high polarity based on urethane bonds, and at the same time, the acid groups of A and the isocyanate of B before crosslinking Excellent adhesion to the metal surface due to the synergistic effect of the properties of high affinity with the base metal surface, preventing the adhesive film from separating from the metal surface due to stress during bending, resulting in stable adhesion. . (c) A is a crosslinked structure due to the reaction between an acid group and a crosslinking agent, B
forms a crosslinked structure due to the reaction between hydroxyl groups and isocyanate groups. The partial formation of the crosslinked structure imparts toughness and makes A and B highly elastic, further improving the crack prevention effect during bending. In addition, the crosslinked structure improves heat resistance and water resistance by improving the poor heat resistance, which is a disadvantage of uncrosslinked structures, and the lack of water resistance due to the influence of emulsifiers, which is a disadvantage of water-based adhesives. Therefore, it is possible to obtain decorative laminates that are highly compliant with the JAS method, which is an important quality standard for decorative laminates, and are of excellent quality. Thus, the adhesives A and B of the present invention are indispensable because their properties provide a high degree of adhesion to metal surfaces, prevent cracks in decorative veneers, and provide excellent adhesive performance in terms of quality. be. The acid group-containing polyurethane resin aqueous dispersion of adhesive A of the present invention is a urethane resin obtained by subjecting an aromatic or aliphatic isocyanate compound and a polyester or polyether compound to a urethanization reaction, which is water-dispersed. The requirement is that the molecule must have an acid group such as a carboxyl group or a sulfonic acid group, and there are no limitations to the manufacturing method as long as this requirement is met. This polyurethane resin dispersion can be used alone or mixed with other aqueous latexes to form an adhesive. Other aqueous latexes include aqueous dispersions of resins or elastomers polymerized with one or more monomers selected from vinyl acetate, acrylic esters, methacrylic esters, acrylonitrile, ethylene, styrene, vinyl chloride, butadiene, chloroprene, etc. I can give an example.
This aqueous latex may optionally be copolymerized with a protective colloid such as polyvinyl alcohol or with a reactive monomer such as acrylic acid, methacrylic acid, glycidyl methacrylate, N-methylolacrylamide, etc., if necessary. The mixing ratio of the polyurethane aqueous dispersion and the aqueous latex based on solid content is 100 parts by weight of the former (hereinafter simply referred to as parts).
The latter is preferably 0 to 1000 copies. Among these polyurethane resins, aromatic or aliphatic polyester urethane resins containing 0.1 to 5% by weight of acid groups are preferred from the viewpoint of adhesion to metal surfaces. Note that a carboxyl group is particularly preferred as the acid group. The water-based latex to be mixed includes water dispersions of polyvinyl acetate, ethylene-vinyl acetate copolymer, acetate-vinyl acrylic copolymer, acrylic copolymer, and styrene stadiene copolymer, which have good adhesion to wooden parts such as wood boards. Liquid is preferred. As a crosslinking agent, 2
Compounds having more than one reactive group are used, specifically epoxy compounds such as glycerin diglycidyl ether and bisphenol type epoxy resin, melamine compounds such as di- or trimethylol melamine and its tethered products, and diphenyl Isocyanate compounds such as methane diisocyanate, 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane, 2,2'-bishydroxymethylbutanol-tris[3-(1-
Examples include aziridine ring compounds such as aziridinyl) propionate. Among these, preferred examples include epoxy compounds and aziridine ring compounds that have good reactivity with the acid group-containing aqueous urethane dispersion.
Particularly preferred are aziridine ring compounds having good room temperature curability. The amount of the crosslinking agent to be blended is preferably 0.5 to 40 parts per 100 parts of the solid content of the aqueous latex containing the acid group-containing polyurethane resin aqueous dispersion. The aqueous latex containing a hydroxyl group-containing water-soluble polymer of Adhesive B of the present invention refers to A containing a synthetic polymer such as polyvinyl alcohol, a cellulose derivative such as hydroxyethyl cellulose, etc. as a hydroxyl group-containing water-soluble polymer. The aqueous latex described in In order to contain this water-soluble polymer in an aqueous latex, an aqueous solution of this water-soluble polymer may be blended into the aqueous latex, or such a water-soluble polymer may be emulsion polymerized as a protective colloid. The water-soluble polymer is preferably polyvinyl alcohol from the viewpoint of adhesion to wood and reactivity with isocyanate, and the water-based latex is preferably polyvinyl acetate or ethylene vinyl acetate from the viewpoint of adhesion to wood. Aqueous dispersions of copolymers, acetic acid biacrylic copolymers, acrylic copolymers, and styrene-butadiene copolymers are good, and in particular, those in which acid groups such as carboxyl groups are introduced into these aqueous latexes are suitable for use on metal parts. This is preferable because it also improves adhesiveness. The amount of water-soluble polymer mixed into aqueous latex is 0.5 to 30 parts per 100 parts of solid content of aqueous latex.
It is better to make it a department. The isocyanate compound is preferably a compound having two or more isocyanate groups in the molecule, and isocyanates are reacted with diisocyanates such as diphenylmethane diisocyanate and hexamethylene diisocyanate, or polyethers or polyesters called urethane prepolymers, It may also have an isocyanate group remaining at the end. Among these, diphenylmethane diisocyanate is preferred. When this isocyanate compound is viscous or for the purpose of extending the pot life, it may be used after being diluted with a solvent or plasticizer such as toluene, ethyl acetate, or phthalate esters. The mixing amount of these isocyanate compounds is preferably 1 to 50 parts per 100 parts of the solid content of the aqueous latex containing the hydroxyl group-containing water-soluble polymer. Adhesives A and B contain thickeners, clay, talc, inorganic fillers such as silica powder, organic fillers such as wheat flour and wood flour, and urea to improve coating properties and other workability. A small amount of thermosetting resin such as formalin resin or phenol-formalin resin may be added as necessary. Furthermore, depending on the type and purpose of the metal plate, a rust preventive agent may also be added. Next, the standard bonding method of the present invention will be described. Usually, the adhesive of the present invention is applied to the surface of the metal plate by using a roll coater, air spray, brush, etc.
Apply 300g/ ^m2 . If the porous sheet is thin or has a coarse texture, set the amount to be applied less, and if the porous sheet is thick or has a fine texture, set the amount to be applied more. The preferred coating weight range is 80 to 200 g/ ^m2 . Thereafter, a porous sheet and a plate are placed on the coated surface. If the adhesive is applied and then crimped, the time between application and crimping is done while the adhesive is still in an undried state, so it is usually better to keep it within 30 minutes. If a longer period of time is required, it is preferable to water the plate or the like in advance to keep it undried. The crimping process is room temperature crimping,
Both heat and pressure bonding are possible. However, heat and pressure bonding is more advantageous in promoting adhesion both during drying and crosslinking. It should be noted here that when performing hot press bonding, if a large amount of moisture remains in the adhesive or the amount of crosslinking agent is small, punctures may occur due to the influence of water vapor, so high temperature press bonding of 100℃ or higher In this case, either wait until it is semi-dry or increase the amount of crosslinking agent. Therefore, the heat-pressing temperature is preferably 60 to 95°C from both the viewpoint of crosslinking promotion and production efficiency. The crimping time and crimping pressure are
Due to the mechanism in which the adhesive applied to the metal plate permeates through the porous sheet and adheres to and integrates with the plate,
Just choose the time and pressure that will allow you to do it.
For example, the crimping time is 1 to 1 when the crimping temperature is 60 to 95℃.
It will take about 5 minutes. On the other hand, the pressure is usually 0.5-10Kg/cm ²
It is preferable to select a range of . In addition, if the porous sheet is thick and dense and it is difficult for the adhesive to penetrate, first glue the metal plate and the porous sheet, then apply the adhesive again on the porous sheet metal plate and attach the plate. A method of crimping can also be used. Further, the coating may be applied to any of the constituent adherends, typically by a method of coating one or both sides of a porous sheet using a roll coater, double-sided roll coater, air spray, or the like. Further, as a pressure bonding method, a hot press method, a roll laminator method, a vacuum press method, etc. can be widely used. The method for manufacturing a natural wood decorative metal plate of the present invention has the following advantageous features. (1) The porous sheet interposed between the attached plate and the metal plate has a structure that allows the adhesive to penetrate, and the most important function of this porous sheet is that it thickens the adhesive layer. be. Even with adhesives having high elasticity such as A and B, if the adhesive layer is thin, it may be difficult to completely eliminate cracks on the plate surface. If we relied only on adhesive and thickened the adhesive layer by increasing the amount of adhesive applied, it would be possible to prevent cracks, but since the adhesive is pressed in an undried state, excessive adhesive It oozes onto the surface of the board, causing stains and significantly detracting from its aesthetic appearance. Therefore, if a porous sheet is used, it will thicken the adhesive layer without excessively increasing the amount of adhesive applied, and the porous sheet will absorb excess adhesive, reducing leakage on the board surface. and the aesthetic appearance improves. In particular, in the case of the present invention, paper waste, which is a type of recycled paper, can be used as the porous sheet, so it has a much more economical advantage than the method of adding thickness to the adhesive layer using only an adhesive. It has the characteristics that can be imparted. (2) Since the adhesives A and B are both water-based adhesives, they are easy to handle, pose no risk of contaminating the working environment or causing fire, and can be used safely and with confidence as a non-polluting adhesive. (3) The bonding method can be the one normally used in the decorative board industry, which is an extremely difficult method in which the adhesive is applied to the base plate, then the porous sheet and the board are laminated in that order, and then they are pressed together when they are still wet. Since it can be carried out even in a simple process, production efficiency is high and existing equipment can be used, making it extremely efficient and economical. (4) Previously proposed method of Japanese Patent Publication No. 49-6086,
In other words, compared to the method using sheet adhesive,
The process is simple and the bonding is done in an undried state, so the bonding is stable without the problem of point adhesion.The bonding mechanism does not use hot melt bonding, so there is no lack of heat resistance, and the bonding performance is excellent. is much better. The thus obtained decorative board of the present invention has the following excellent characteristics. (1) It is a decorative board of excellent quality that complies with the advanced tests specified in the Japanese Agricultural Standards, such as the JAS Class 1 immersion peeling test and the JAS cold/heat cyclic A test. (2) In a bending test using a steel plate bending machine,
Since it does not crack even when bent at right angles, it can be freely processed into various curved surfaces, including sharp bending, and can be given a high degree of design. (3) Since the base material is a metal plate, there is little risk of fire. In addition, since there is no such decorative board, a decorative board with a real precious wood surface is provided in a field where PVC steel sheets with wood grain printing on the surface are used as a substitute, so it has a so-called depth that cannot be compensated for by printing technology. We can provide decorative panels that look like the real thing. Also, in the unlikely event of a fire accident, it will not emit toxic gas unlike PVC steel plates. It goes without saying that even if the decorative board of the present invention is subjected to burnout, the burnout will only occur on the surface. (4) When the decorative board of the present invention is used as an electromagnetic wave shielding material for computer-related equipment, etc., since the substrate is metal, it is conductive and causes electromagnetic interference (EMI).
It is effective in preventing accidents involving electronic devices such as computers, which have recently become a problem. In this way, unexpected and unknown uses can be expected. A detailed explanation will be given above using examples. Example 1 Carboxyl group-containing aromatic isyanate polyester polyurethane aqueous dispersion (resin content
44.8%, simply abbreviated as urethane Em), ethylene vinyl acetate copolymer aqueous dispersion containing polyvinyl alcohol (resin content 55.3%, simply abbreviated as EVAEm),
2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] (simply abbreviated as aziridine ring compound) as a crosslinking agent was blended as shown in Table 1 to prepare four types of adhesives A to A. I got a D.

[Table] Using these adhesives A to D, apply each adhesive to a galvanized iron plate with a thickness of 0.5 mm at a coating amount of 150 g/m ² and apply it to a 180 μm acetate nonwoven fabric (manufactured by Nippon Vilene). ) and a 0.2 mm thick birch wood board was placed on it. After coating, heat and compression bonding was carried out using a hot press device within 10 minutes. The conditions were 70°C x 3 minutes x 5Kg/cm ² . After curing each of the thus bonded samples at room temperature for 2 days, performance was evaluated using the following test method. In addition, using the urethane adhesive (containing ethyl acetate, referred to as adhesive E) that does not contain acid groups as in Example 1 of Japanese Patent Publication No. 10887/1987, the same adhesive material and method as in Example 1 of the present invention were used. I did the gluing work. Adhesive E, a solvent-based urethane, could not be applied using a normal roll spreader due to the danger of organic solvents and the severe stringiness, so it was applied using a paint brush. Also, since it can be dangerous if it is not allowed to dry after application, it was allowed to dry for 20 minutes in a place without open flames before hot press bonding. Test method (1) JAS class 2 immersion peeling test (hot water test) The test method follows the JAS standard for special plywood. (Judgment) ◎: No abnormality in appearance ○: Slight cracking, but no blistering or peeling △: Conspicuous cracking, blistering, or peeling ×: Conspicuous cracking, blistering, or peeling (2) JAS Class 1 immersion peel test (Boiling water test) The test method follows the JAS standard for special plywood. (Judgment) Same as the above judgment (3) JAS cold and hot cyclic A test (dry cracking test) The test method follows the JAS standard for special plywood. (Judgment) ◎: No abnormality in appearance ○: Slight cracks (dry cracks) △: Conspicuous cracks ×: Severe cracks (4) Close contact test (Test method) Metal Make cuts parallel to and perpendicular to the wood grain of the board to make a 20mm square. The number of squares in this square is 100. Apply a cloth tape with strong adhesive called duct tape to this grid area and make sure it adheres well.Approximately 45cm
Peel it all at once at an angle of 30 degrees. (Judgment) The greater the number of squares that do not separate, the better the adhesion (maximum 100 pieces) (5) Bending test (Test method) A sample cut into 30 cm vertically and 15 cm horizontally is bent on an iron plate in the direction of the wood grain. Using a machine [manufactured by Morimitsu Co., Ltd.], bend the board at once to a right angle so that the surface of the board forms a mountain. (Judgment) Look at the mountain and the cracks around it. ◎: No cracks in the bent part ○: Fine cracks occur but are not noticeable △: Cracks are noticeable ×: Test results with severe cracks exposing the metal plate Samples bonded with adhesives A to E were
The test results are shown in Table 2.

【table】

[Table] , is a product of the present invention, which has excellent adhesive performance and does not crack at all even in a bending test. In the comparative example, a crosslinking agent was blended with an aqueous latex that did not contain urethane Em, but in the bending test, the cracks were severe and the metal surface was exposed, and the adhesion was poor and the adhesion performance was poor. Although the cross-linking agent is omitted, although it has flexibility, it lacks toughness and cracks open during the bending test, and its adhesion performance is also unsatisfactory. uses a polyurethane adhesive that does not contain acid groups, but its performance in the adhesion goblin test and bending test is insufficient. Example 2 Carboxyl group-containing aliphatic isocyanate polyester polyurethane aqueous dispersion (resin content
44.3%) and 20 parts of an aqueous polyvinyl acetate dispersion containing polyvinyl alcohol were mixed with 4,4'- as an aziridine ring compound.
Six parts of an aqueous dispersion containing 25% bis(ethyleneiminocarbonylamino)diphenylmethane was blended as a crosslinking agent. This was used as an adhesive to adhere a 0.5 mm thick galvanized iron plate, a 0.25 mm thick oak wood plate, and various porous sheets, with varying amounts applied. Crimping was performed within 15 minutes after application. Crimping conditions are 80℃ x 2
After curing at room temperature for ² days, the test was conducted according to Example 1. The porous sheets used and the amount of coating are shown in Table 3. Table 3 No. Porous sheet Application amount (m ²
(a) Paper waste [trade name: Kojin Wiper Co., Ltd.] 100g (b) Hanshi paper 150g (c) Shoji paper 200g (d) Newspaper 150g (e) 80g titanium paper 240g However, only 80g titanium paper, metal 120g/ ^m2 once on the board
After coating, put titanium paper on top of it and apply 120g/
m ² of adhesive was applied. The test results are shown in Table 4.

[Table] Various porous sheets as shown in (a) to (e) above can be used in the present invention. In this case, the easier the adhesive penetrates, the better the results tend to be, but all porous sheets are highly compatible with JAS Class 1 immersion peel test, JAS Class 2 immersion peel test, JAS cold and hot cyclic A test, and bending test. also showed good results. Example 3 Aqueous latex obtained by blending 25 parts of calcium carbonate as an extender with 30 parts of a 15% polyvinyl alcohol aqueous solution and 70 parts of an aqueous dispersion of butadiene styrene copolymer containing carboxyl groups (resin content 50.3%). Diphenylmethane diisocyanate (trade name: Millionate MR, manufactured by Nippon Polyurethane Industries)
5 parts or 15 parts of the above were mixed, and an aluminum plate (thickness: 0.5 mm) was used as the metal plate, and the mixture was laminated in the same manner as in Example 1. Then, the same test as in Example 1 was carried out.
Table 5 shows the results. Materials laminated with an adhesive containing 5 parts or 15 parts of diphenylmethane diisocyanate are labeled as and.

[Table] Example 4 An adhesive containing 3 parts of a polyfunctional epoxy compound (trade name CR5L, manufactured by Dainippon Ink Industries) as a crosslinking agent instead of the aziridine ring compound per 100 parts of the aqueous latex obtained in Example 2. The test was carried out by laminating and testing in the same manner as in Example 1. As a result, the same results as in Example 1 were obtained. Example 5 Using the adhesive B of Example 1 and an aluminum plate with a thickness of 0.5 mm, apply it to a coating amount of 120 g/ ^m2 , place a 180 μ nonwoven fabric (acetate type, manufactured by Nippon Vilene), and adjust the thickness. A board with oak wood with a diameter of 0.2 mm was placed on it. Next, two sheets of the above-mentioned nonwoven fabric were stacked at a coating weight of 140 g/m ² , and three sheets of the nonwoven fabric were stacked at a coating weight of 160 g/m ² . Crimping was performed within 10 minutes after application. The pressure bonding method was a room temperature press method, and the conditions were room temperature x 60 minutes x 2.5Kg/ ^cm2 . After bonding and curing at room temperature for 5 days, the same test as in Example 1 was conducted. Similar results as in Example 1 were obtained.

Claims (1)

[Scope of Claims] 1 A natural wood decorative veneer, a porous sheet-like material, and a metal plate are the constituent elements, and are selected from an aqueous latex containing an aqueous dispersion of an acid group-containing polyurethane resin, an epoxy compound, and an aziridine ring compound. A natural wood-decorated metal characterized by being pressure-bonded in an undried state using a water-based adhesive consisting of a combination of a cross-linking agent or a combination of an aqueous latex containing a hydroxyl group-containing water-soluble polymer and an isocyanate compound. Method of manufacturing the board. 2. The manufacturing method according to claim 1, wherein the aqueous latex containing the acid group-containing polyurethane resin aqueous dispersion is the acid group-containing polyurethane resin aqueous dispersion alone. 3. The manufacturing method according to claim 1, which uses a plurality of porous sheet materials.