JPH0375003B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing a decorative wood material used as a finishing material for construction such as flooring or as a surface material for furniture. (Prior art and its problems) Wood has traditionally been widely used for decorative materials, other interior materials, furniture, etc. because it has advantages such as good workability and beautiful wood grain. There were problems in that the material was damaged, abraded, chipped, dented, and even fuzzed, and it also attracted pollutants and changed color, resulting in staining in a short period of time. For this reason, a coating film is applied to the wood surface, but it is said that in order to solve the above problems, it is necessary to provide a uniform coating film with a thickness of 30 μm or more on the wood surface. As a result, the paint film creates an excessive gloss on the wood surface, impairing the textured appearance.Additionally, in order to apply a paint film of such thickness, an undercoating and drying process is required. There was a problem that the process had to be repeated, resulting in a decrease in productivity. In order to eliminate these problems and improve durability, so-called WPC materials are known, which are made by injecting synthetic resin liquid into the minute voids of wood and curing it. Even in wood that has been
This is insufficient to prevent water and contaminants from entering the wood structure or the interface between wood and synthetic resin, and as above, it is necessary to cover the surface with a uniform coating film, which reduces the fine grains of wood. The problem was that it was not possible to take advantage of it. The present invention was made in view of these problems, and it provides an appearance that emphasizes the antique cosmetic properties of wood, which is imprinted with oil and fat, which has a deep oil finish that is inherent to wood. The present invention provides a method for producing a decorative wood material with improved properties, especially stain resistance. (Means for Solving the Problems) In order to achieve the above object, the method for producing a wood decorative material in the present invention is to fill a thin wood board in which the hydroxyl groups in the wood component have been acetylated with a lipophilic synthetic resin liquid. After curing, the synthetic resin adhering to the surface layer of the synthetic resin injection-treated thin wood board is exposed by grinding, and oil and fat are applied to the exposed surface so as not to form a uniform coating. It is characterized by penetration and layering. The wood species of the thin wood board may be either softwood or hardwood, but in order to facilitate the acetylation treatment and resin injection treatment, it is recommended to use a thin wood board with a thickness of 0.2 to 10 mm. preferable. In order to acetylate the thin wood board, the thin wood board is impregnated with an aqueous solution of metal acetate such as sodium acetate or potassium acetate as a catalyst in the absence of a catalyst or as a catalyst, dried, and then treated with acetic anhydride or chloroacetic anhydride. Immerse in the acetic anhydride reaction solution at 100-150℃.
By heating at a temperature of from several minutes to several hours, the hydroxyl groups in the wood component are replaced with the acetyl groups of acetic anhydride. Thereafter, the excess reaction solution is drained, and the wood laminate is washed and dried. The synthetic resin injection treatment of the wood veneers takes place after this acetylation treatment. As the resin liquid to be injected, prepolymers such as lipophilic unsaturated polyesters, epoxy resins, and acrylic urethane resins, and polymerizable monomers such as styrene monomers, methyl methacrylate, styrene oxide, and epichlorohydrin may be used alone or in mixtures. In order to facilitate injection into thin wood boards, it may be diluted with a solvent such as toluene or xylene as necessary, or a polymerization initiator such as benzoyl peroxide, a plasticizer or an appropriate coloring agent may be mixed. You can leave it there. Among these resin liquids, if you use a resin liquid made by diluting a prepolymer such as an unsaturated polyester resin with a polymerizable monomer such as a styrene monomer, it can be injected into thin wood boards at a particularly high filling rate, and it can be heated and cured. The subsequent pressure resistance and dimensional stability are good. As a means of injecting such a resin liquid into a thin wood board, a dipping method, a reduced pressure method, a pressure method, or a reduced pressure method is adopted. After injection, the thin wood board is heated to 80 to 150°C.
The resin liquid injected into the thin wood board is cured by heating and applying pressure for several minutes to several tens of minutes. The resin injection hardened thin wood board thus obtained is then ground to remove excess resin adhering to the surface and expose the surface layer of the thin wood board to reveal fine grains. This allows easy penetration and adhesion of oils and fats, which will be described later. As the grinding means, sandpaper, brush sander, buff sander, sandblasting, etc. may be used alone or in combination. In this way, when the surface layer portion of a thin wood board that has been subjected to resin injection hardening treatment is ground, the grinding state can be varied depending on the difference in resin injection density within the thin wood board. For example, when a resin liquid is mixed with a plasticizer, low-density areas or void areas such as wood conduits or spring wood areas can be greatly ground to create a raised grain pattern. After the surface of the resin injection hardened thin wood board is ground, oil is applied to the ground surface and allowed to penetrate. The oils and fats used include drying oils such as linseed oil and tung oil, semi-drying oils such as soybean oil and sesame oil, dehydrated castor oil, maleic oil, isomerized conjugate acid oil, ester synthetic drying oil, styrenated oil, and urethanized oil. , synthetic drying oils such as epoxy modified oils, oil-based varnishes, oil-based phenols, etc., and those with low molecular weight and good permeability into thin wood boards are particularly preferred. Note that an appropriate solvent, antioxidant, ultraviolet absorber, colorant, etc. may be added to the above-mentioned fat or oil. Application methods include spray, roll coater,
This is done using a reverse coater or dip coating. After coating, excess oil and fat on the coated surface is wiped off with a cloth or brush. This application process does not need to be repeated, nor does it require the use of special equipment for curing unlike conventional coatings. (Function) Untreated thin wood boards have hydroxyl groups in their wood components, so they are hydrophilic and easily absorb and release moisture, and as they absorb and release moisture, they expand and contract significantly. When the hydroxyl groups in the wood components are acetylated, it becomes difficult to absorb and release moisture, which not only reduces dimensional changes in the thin wood board, but also makes it nearly lipophilic, making it difficult for the injected resin liquid to penetrate into the microscopic voids within the thin wood board. This promotes hardening of the injected resin liquid even within the wood cell walls and at the cell wall interface, resulting in good filling. As a result, the resin and coloring agent penetrate into the fine grains of the wood, deepening the grain, and the wood hardly reacts with moisture, and furthermore, the injected resin prevents moisture from penetrating. In addition, the surface layer of the acetylated thin wood board that has been subjected to resin injection hardening treatment is ground to remove excess resin and expose the wood surface, and the exposed surface is coated with oil and fat, which penetrates into the wood cell wall. Penetration and adhesion to the sides are achieved, emphasizing the wood grain, and in conjunction with the filling of the resin described above, a deep wet color is obtained, as well as improved water repellency and inactivation against pollutants in the wood. Designed, water resistant,
It has improved weather resistance and maintains a beautiful appearance over a long period of time. (Example) Next, specific examples of the present invention will be shown. Example 1 A 1.5 mm thick oak veneer was treated with acetic anhydride (reactive agent).
After being immersed in water and heated at 125° C. for 1 hour in the absence of a catalyst for acetylation treatment, the wood was washed and dried to obtain an acetylated wood thin plate having an acetyl group content of 14%. A resin liquid prepared by adding 10 parts by weight of dibutyl phthalate and 1 part by weight of benzoyl peroxide to 100 parts by weight of unsaturated polyester was injected into the acetylated thin wood board under reduced pressure and then pressurized, and then hot pressed at 130°C. The material was hot-pressed for 20 minutes and polymerized and cured to obtain a resin-injected acetylated wood laminate. Next, the resin adhering to the surface layer of the resin-injected acetylated thin wood board was removed by grinding.
After adhering to the plywood using a water-based vinyl urethane adhesive, and polishing the decorative surface with sandpaper (#240) to expose the surface layer of the thin wood board, apply 10 g of tung oil to the ^surface . Apply at the rate of
After allowing it to penetrate and leave for 20 to 30 minutes, the tung oil adhering to the surface was wiped off with a waste cloth, and then left to dry at room temperature for 48 hours to obtain a decorative material. Example 2 As a resin liquid injected into a 1.5 mm thick oak veneer,
The resin liquid used in the above example was mixed with 0.05% by weight of an oil dye (brown), and the oil was a synthetic drying oil (CP oil) made by adding cyclopentadiene to linseed oil, and one portion of cobalt octylate was added. A decorative material was obtained by carrying out the same treatment as in the above example using the added material in an amount of % by weight. Comparative Example 1 A commercially available urethane resin was applied to the surface of a 1.5 mm thick oak veneer without acetylation treatment or resin injection treatment.

【table】

[Table] In Tables 1 and 2 above, stain resistance 1 and 2, water resistance, and weather resistance were tested by the following tests. Stain resistance 1: Red crayon according to JAS-A test,
After applying black magic and blue ink, wipe it off. Stain resistance 2: Water-based ink was diluted 5 times, immersed in this diluted solution at 40°C for 24 hours, and then washed. Water resistance: The process of soaking in warm water at 80°C for 2 hours and then drying was repeated three times. Weather resistance: Exposure outdoors for 3 months. In addition, in the appearance of the decorative materials obtained in Examples 1 and 2 above, a thin heathered pattern appears compared to the decorative material obtained in Comparative Example 1, and the texture is not impaired. The deep makeup created by the bleeding of the dye is emphasized, and the acetylation treatment improves the adhesion of the injected resin to the wood cells, making it far more durable than ordinary WPC that is simply resin injected and hardened. It has the following. (Effects of the Invention) As described above, in the method for producing a wood decorative material according to the present invention, a thin wood board in which hydroxyl groups in wood components have been acetylated is filled with a lipophilic synthetic resin liquid and cured, and then the synthetic resin The synthetic resin adhering to the surface layer of the injection-treated thin wood board is ground to expose the surface of the treated wood thin board, and oil and fat are penetrated and layered so as not to form a uniform coating on the exposed surface. Since the hydroxyl groups in the wood components are acetylated, moisture absorption and desorption becomes difficult, and dimensional changes in the thin wood board are reduced.It also becomes close to lipophilic, so it absorbs into the microscopic voids within the thin wood board. The penetration of the injected base resin liquid is promoted, and the injected resin liquid adheres and hardens even within the wood cell walls and at the cell wall interface, resulting in good filling. Furthermore, the surface layer of the acetylated thin wood board that has been subjected to resin injection hardening treatment is ground to remove excess resin and expose the wood surface, and oil is applied to the exposed surface and permeated, allowing it to penetrate into the wood cell wall side. Penetration and adhesion of oils and fats are achieved, improving water repellency and inactivating contaminants on the wood, resulting in water resistance,
In addition to improving weather resistance, it is possible to obtain a deep and beautiful wood decorative board that shows even the fine grains without impairing the texture of the material compared to conventional wood decorative boards that have been coated with a coating. Furthermore, since there is no need to repeat the undercoating and drying processes unlike conventional painted wood decorative boards, productivity can be improved. In addition, compared to painted wooden decorative boards or conventional decorative boards that are simply treated with resin injection hardening, the stain resistance, water resistance, and weather resistance are significantly improved, providing a beautiful appearance over a long period of time, and improving the fabric finish. It can also be used for applications that are not suitable for painted finishes, such as floating finishes, etc., and can be repaired with commercially available wax, etc., and maintains good cosmetic properties.

Claims (1)

[Claims] 1. A thin wood board that has been treated to acetylate the hydroxyl groups in the wood components is filled with a lipophilic synthetic resin liquid and cured, and then the synthetic resin adhering to the surface layer of the thin wood board treated with synthetic resin injection is ground to obtain the above-mentioned treated wood. 1. A method for producing a decorative wood material, which comprises exposing the surface of a thin plate, and penetrating and layering oil and fat so as not to form a uniform coating film on the exposed surface.