JP5027046B2 - Wood board - Google Patents

Description

  The present invention relates to a wooden board used for a building material for a house such as a flooring material, a counter, and a door.

  Due to the recent increase in genuineness, nature, and health, there is a need for building materials for homes that have a natural and textured feel. Wood has been widely used for fittings and furniture since ancient times as a veneer or a solid material because of its beautiful grain, good touch, moderate strength, and good workability. However, because there are problems such as easy to get dirty, easy to scratch, easy to break, and easy to wear, it is conceivable to create a thick coating on the surface to solve these problems. There was a problem that the appearance was sacrificed, such as damage to the surface.

In order to avoid the formation of a coating film having a thick surface, which causes damage to the wood texture, it has been widely practiced to impregnate wood with a resin. In the old days, wood has been put into a sealed container, and after reducing the pressure, the resin is injected, and the resin is impregnated inside the wood by pressurization. There was a problem as shown.
(1) In the impregnating equipment that can be sealed, the treatment method becomes a batch type in order to impregnate the resin by depressurization and pressurization, and the treatment time is longer than the continuous production method.
(2) A large facility with a capacity of about 2 m in diameter and a length of about 5 m is required to process a flooring material or a counter material having a length of about 2 to 4 m, which is not suitable for the production of a small lot.
(3) Since the impregnation treatment is performed by immersing wood in the resin, when the resin is cured inside the wood, the resin adhering to the surface of the wood is also cured to form a cured resin, which takes time to remove.
(4) Since the structure of the wood is not uniform, if the entire wood is dipped, resin impregnation variation is likely to occur. If there is variation in resin impregnation, the resin will cure and shrink, causing warping and cracking in the wood. If a large amount of resin enters the interior, a feeling of resin occurs and the wood texture is impaired.

  Therefore, in recent years, in view of such a point, resin impregnation in a continuous production system utilizing current coating equipment is also seen. For example, the aim is to impregnate only the surface layer where the highest performance is required by reducing the viscosity and molecular weight of the resin, and without making a thick coating on the surface, wood texture, chemical resistance and contamination resistance It is considered that such a method for making the coating film performance such as property compatible is effective (see, for example, Patent Documents 1 and 2).

  However, simply by impregnating the wood surface layer with a low viscosity and low molecular weight resin, it is not possible to completely cover the wood cells. In practice, an alkaline bleach used for baths and kitchens is not used. When the chemical resistance test was carried out by hanging on the surface of the wood, there was a problem that the portion of the wood cell that was not completely covered with the resin was discolored and whitened, particularly in the canal portion. Therefore, if a large amount of the above resin is impregnated and applied so that the wood cells are completely covered, the resin is filled in the concave portions such as the pipe portions on the surface of the wood, and the wood texture is impaired. there were.

By the way, Patent Document 3 discloses an aqueous coloring paint using an ultraviolet curable resin having an average molecular weight of 1600 to 15000. The UV curable resin having such an average molecular weight is used for tack-free and dry-curing, and does not describe protection of the canal portion on the wood surface, but rather is a recess in the canal portion on the wood surface. It is described that the inside is filled. This water-based colored paint is intended to improve the adhesion between the colored layer and the clear layer, and is essentially different from the present invention which forms a coating film that exhibits a good wood texture. .
JP 2006-152142 A JP 2002-146270 A JP 2004-339500 A

  The present invention has been made in view of the circumstances as described above, and it is an object of the present invention to provide a wood board on which a coating film exhibiting a good wood texture is formed and which has good coating film properties. .

  In order to solve the above problems, the wood board of the present invention is characterized by the following.

First, a thin film protective layer having a thickness of 5 to 50 μm of a polymer resin having an average molecular weight of 10,000 or more is formed on the surface of a wooden substrate, and a low-viscosity resin is applied thereon and cured. A coating layer is formed.

  Second, in the first invention, the low-viscosity resin includes a fluorine-based resin or a silicone-based resin.

  Third, in the first invention or the second invention, the thin film protective layer contains a color pigment.

  Fourthly, in any one of the first to third inventions, the surface of the wooden substrate is subjected to a sea urchin process.

According to the first invention, a thin film protective layer having a thickness of 5 to 50 μm of a polymer resin having an average molecular weight of 10,000 or more is formed on the surface of the wood substrate, and a low-viscosity resin is applied thereon and cured. As a result of the coating layer being formed, the conventional problems can be solved, and the appearance of a high-quality wood texture with a natural feeling and texture can be achieved. Contamination can be realized.

  According to the second invention in which the low-viscosity resin contains a fluorine-based resin or a silicone-based resin, in addition to the effects of the first invention, chemicals and dirt substances are removed by the water-repellent effect of the fluorine-based resin or the silicone-based resin. A repelling phenomenon is observed, and further effects such as resistance to dirt and ease of wiping off can be expected.

  According to the third invention in which the color pigment is contained in the thin film protective layer, in addition to the effects of the first invention and the second invention, the design of the wooden board can be more effectively enhanced.

  According to the fourth invention in which the surface of the wooden substrate is processed, in addition to the effects of the first to third inventions, the unevenness of the surface of the wooden substrate is emphasized. The texture can be further enhanced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view of a wood board according to the present embodiment.

  As shown in FIG. 1, in the wood board according to the present embodiment, a thin film protective layer 3 of a polymer resin is formed on the surface of a wood base material 1 having a recess formed by a passage 8 on the surface, and a low viscosity is formed thereon. The coating film layer 4 formed by applying and curing the resin is formed.

  The thin film protective layer 3 formed on the surface of the wood substrate 1 is formed by curing a polymer resin having an average molecular weight of 10,000 or more, preferably 100,000 to 1,000,000, and has a thickness of 5 to 50 μm, preferably 10 It is a resin film in the range of ˜30 μm. Such a polymer resin is hardly impregnated into the wooden base material 1 and the thin film protective layer 3 is formed as a film. In forming the thin film protective layer 3, it is desirable to use a material obtained by diluting the polymer resin in a solvent such as water, an organic solvent such as toluene, xylene or alcohol. In particular, when water is used as a solvent, wood cells can be swelled, which makes it difficult for the polymer resin to permeate the wooden substrate 1 and facilitates the formation of a thin film. When a polymer resin solution diluted with a solvent such as water or an organic solvent is applied to the surface of the wooden substrate 1, the drying rate of the film is appropriately adjusted by volatilization of water or the organic solvent. For this reason, immediate drying of the film can be suppressed, thereby making it possible to form a stable film having no fleshiness (feeling that it has been thickly coated) and having few defects and a substantially uniform thickness. By forming the thin film protective layer 3 on the surface of the wooden base material 1 in this way, the low-viscosity resin applied from above becomes difficult to penetrate into the wooden base material 1, and the coating film is stable even if thin. Is formed. As a result, a high-quality wood texture can be obtained, and chemical resistance and contamination resistance can be improved.

As such a polymer resin liquid, for example, an aqueous urethane-based or acrylic-based emulsion or dispersion having a solid concentration of about 10 to 50% can be mentioned, and this can be applied in an amount of about 3 to 8 g / scale ^2. Can be applied as a guide. By using an aqueous emulsion or dispersion, the viscosity does not increase so much even if the average molecular weight is increased, so that it does not become difficult to apply. Such an aqueous emulsion or dispersion may be a one-component type or a two-component type. In the case of the one-component type, molecules are fused and cured by evaporating water. In the case of the two-component type, isocyanate is used as a curing agent, and the isocyanate is crosslinked and cured so as to fill the space between the polymers. Although two-liquid liquefaction causes a problem of pot life, a tough film having better chemical properties can be formed. Further, the presence of isocyanate improves the adhesion due to bonding with the hydroxyl group of wood, and further, if there is a hydroxyl group in the low-viscosity resin applied on the film, the adhesion is improved. Regarding the application method to the wooden substrate 1, a roll coater is used in consideration of productivity, and a sponge roll coater is used in consideration of effective application to the concave portion (8 parts of the canal) on the surface of the wooden substrate 1. preferable. As a solvent in the polymer resin solution, water is desirable because it swells wood cells and the resin does not easily penetrate and forms a film. Furthermore, water is desirable from the environmental point of view.

  In the present embodiment, a color pigment may be added to this water-based urethane-based or acrylic-based emulsion or dispersion. Usually, wooden building materials are colored in order to enhance the design properties, but in this embodiment, by adding a color pigment to the polymer resin liquid to be the thin film protective layer 3, the formation of the thin film protective layer 3 and Both the coloring processes can be completed in one step, and productivity can be improved.

  In this embodiment, a low-viscosity resin is applied on the thin film protective layer 3 to form the coating film layer 4. The presence of the thin film protective layer 3 makes it difficult for the low-viscosity resin applied on the thin film protective layer 3 to penetrate into the wooden substrate 1, and the stable coating layer 4 can be formed even if the amount of resin applied is small. It can be formed on the thin film protective layer 3. “Low viscosity” in the low-viscosity resin applied on the thin film protective layer 3 refers to a viscosity at the time of coating, for example, 2000 mPa · s or less at 25 ° C. The lower limit is not particularly limited, but is actually about 10 mPa · s in consideration of being a resin. If the viscosity is higher than 2000 mPa · s, the concave portion on the surface of the wooden substrate 1 is filled, and the wood texture may be impaired, which is not preferable. In general, a resin solution diluted with a solvent or the like may be prepared to have a viscosity of 2000 mPa · s or less (25 ° C.). Further, the viscosity can be lowered by heating the wood substrate 1 and the resin.

As the low-viscosity resin used here, a resin containing a fluorine-based resin or a silicone-based resin is desirable. By applying such a resin on the thin film protective layer 3, a perfluoroalkyl group or an alkoxyl group exhibiting a water repellency effect is inclined on the surface to express higher chemical resistance and contamination resistance. Can do. On the contrary, if the thin film protective layer 3 is not provided, the wood base material 1 has a porous structure, so that the fluororesin or silicone resin penetrates the wood base material 1 and the perfluoroalkyl group or alkoxyl group is inclined. Inability to resist chemicals and contamination. Such a resin can be applied at a solid content concentration of 10 to 40% by a roll coater, a spray coater, or the like at about 3 to 10 g / scale ² . In order to enhance the adhesion with the thin film protective layer 3, isocyanate may be added in a range of, for example, 1 to 10% by weight, preferably 3 to 5%.

In addition to this, as the resin used, in view of productivity, a resin that is cured by ultraviolet rays (UV) can be used. Examples thereof include resins mainly composed of oligomers such as urethane acrylates, polyester acrylates, and polyether acrylates. By setting it as a 3-5 functional polyfunctional type, a highly crosslinked dense coating film can be formed. Such a resin can be applied with a roll coater or the like with a solid content concentration of 50 to 100% and a coating amount of 1 to 3 g / scale ² or so. In the case where the thin film protective layer 3 is not formed, in order to form a stable coating layer 4 on the surface of the wooden substrate 1, for example, at a solid content concentration of 50 to 100%, at least a coating amount of about 6 g / scale ² The above was necessary. In this case, the coating film layer 4 becomes thick and a feeling of fleshiness comes out, and the wood texture is impaired. In the present embodiment, since the thin film protective layer 3 is formed, the amount of resin applied may be smaller than the conventional amount as in the case of an application amount of 1 to 3 g / scale ² at a solid content concentration of 50 to 100%. A stable coating layer 4 can be formed. In addition, the wood texture is not impaired in such a range of application amount. Furthermore, since it is a UV-cured dense coating film, the scratch resistance can be improved.

  In the present embodiment, a top coat can be applied on the coating layer 4 with a roll coater or the like. Thereby, the coating film 5 of the top coating material is formed on the surface of the coating film layer 4. The top coating used for top coating is preferably a low-viscosity resin similar to the resin used for forming the coating layer 4, but is not particularly limited. For example, in order to improve chemical resistance and contamination resistance, a resin containing a fluorine resin or a silicone resin may be applied. Further, a solvent-free UV curable paint may be used in consideration of environmental aspects and productivity. By using highly cross-linked dense UV curable resin as the low viscosity resin and applying a resin containing fluorine-based resin or silicone-based resin as the top coat, chemical resistance and contamination resistance in addition to scratch resistance Can be improved. When applying the top coat, a wood board with a natural feeling can be obtained by matte finish without filling the 8 parts of the pipe. Furthermore, antifouling effects can be expected by applying a top coat.

  The wooden base material 1 in this embodiment can illustrate MDF, a plywood, or what stuck the veneer on the surface. For example, an oak veneer 2 having a thickness of 0.2 mm is bonded to the surface of a plywood having a thickness of 12 mm with an adhesive, and then processed with a nylon brush containing abrasive powder. Here, Uzukuri processing is as follows. In other words, a tool made by drying and bundling the roots of Susuki and wrapping it tightly with string is called `` Udukuri ''. Since the portion is hardly shaved, irregularities are formed on the surface. Such a processing method is referred to as “zukuri processing”. Actually, the processing is performed by brushing with a polyamide resin (nylon) brush, a wire brush or the like as described above. The veneer bonded to the plywood is not limited to the type of hardwood or coniferous tree, but a ring-hole material that stands out in the canal, such as oak, oak, tamo, and zelkova, is desirable. Since the pipe part is deeply cut by the scouring process, the unevenness becomes clearer, and even a veneer having a thickness of about 0.2 mm has a three-dimensional effect. Moreover, in order to prevent the veneer from cracking or to prevent dents due to casters or the like, the plywood may be a cross plywood or a reinforcing layer such as MDF may be inserted.

  FIG. 2 is a schematic cross-sectional view of a wooden board according to another embodiment. In addition, the same code | symbol is attached | subjected about the part same as the part shown in FIG. 1, and description is abbreviate | omitted.

  In this embodiment, before applying the emulsion or dispersion such as water-based urethane or acrylic that forms the thin film protective layer 3, in order to increase the mechanical strength (scratch and wear) of the wooden substrate 1, It is desirable to impregnate and cure a low-viscosity resin in the vicinity of the surface of the wooden substrate 1. For example, when the wood substrate 1 uses a plywood and a veneer bonded to its surface, the resin is impregnated in the vicinity of the surface by impregnating and curing a low-viscosity resin from the surface of the veneer. The hardened layer 6 is formed, and the mechanical strength of the veneer portion of the wooden substrate 1 can be increased. The resin used here is a resin having a lower viscosity than that used for forming the coating layer, for example, a resin having a low molecular weight of 100 mPa · s (25 ° C.) or less, which is applied after the thin film protective layer 3 is formed. By impregnating the resin, the mechanical strength can be improved without forming a thick coating film on the surface.

<Example 1>
An oak veneer having a thickness of 0.2 mm was bonded to the surface of the plywood having a thickness of 12 mm by a hot press using a vinyl acetate adhesive to obtain a wooden substrate. In order to emphasize the wood texture, the surface of the wood substrate was brushed with a nylon brush containing abrasive powder and processed into a lacquer.

Subsequently, the surface of the wood substrate is colored with a two-component aqueous polymer urethane resin diluted with water (Fresh Aqua SP100 2K, manufactured by Capital Paint Co., Ltd., solid content 28%, average molecular weight 500,000 to 600,000). After adding an agent and applying 6 g / scale ² using a roll coater, water was volatilized by IR drying.

Further, a solvent-diluted UV curable resin (UV sanding A, manufactured by Capital Paint Co., Ltd., 83% solid content, about 150 mPa · s (25 ° C.) in a solvent-diluted state) is 2 g / scale using a roll coater. ^After applying ² and volatilizing the solvent, the coating was cured by UV irradiation and the surface was polished with # 400 abrasive paper.

Next, as a top coating, a solvent-free UV curable coating (Aurex 450FC matte, China Paint Co., Ltd., about 1500 mPa · s (25 ° C.)) is applied with 0.7 g / scale ² using a roll coater, A wood board was produced.
<Example 2>
In Example 1, except that the thin film protective layer made of an aqueous polymer resin was changed from a two-component aqueous polymer urethane resin to a one-component urethane resin (average molecular weight of 500,000 to 600,000). A wood board was produced in the same manner as in Example 1.
<Example 3>
In Example 1, a thin film protective layer made of a water-based polymer resin was changed from a two-component water-based polymer urethane resin to a two-component acrylic resin (for Wonder Hybrid Roll, manufactured by Capital Paint Co., Ltd., solid content: 37%. A wood board was produced in the same manner as in Example 1 except that the average molecular weight was changed to 200,000 to 300,000).
<Example 4>
In Example 1, instead of the solvent-diluted UV curable resin, 5 g / scale ^{2 of} fluorine-based resin (solid content 20%, about 15 mPa · s (25 ° C.) in a solvent-diluted state) containing 5% of isocyanate was added. A wood board was produced in the same manner as in Example 1 except that it was applied and dried and cured at room temperature, and surface polishing with # 400 abrasive paper or no top coating was applied.
<Example 5>
In Example 1, in place of the solvent-diluted UV curable resin, 5 g / scale ^{2 of} a silicone-based resin (solid content 20%, about 15 mPa · s (25 ° C.) in a solvent-diluted state) containing 5% of isocyanate. A wood board was produced in the same manner as in Example 1 except that it was applied and dried and cured at room temperature, and surface polishing with # 400 abrasive paper or no top coating was applied.
<Example 6>
In Example 1, 5 g / scale ^{2 was} applied as a top coat paint to a fluorine-based resin (solid content 20%, about 15 mPa · s (25 ° C.) in a solvent diluted state) containing 5% of isocyanate, and dried at room temperature. A wood board was produced in the same manner as in Example 1 except that it was cured.
<Example 7>
In Example 1, an impregnating sealer (UV sealer, manufactured by Capital Paint Co., Ltd., solid content) diluted with a solvent for the purpose of reinforcing the veneer part before forming a thin film protective layer made of an aqueous polymer resin. Apply about 90mPa · s (25 ° C) in a diluted state of 67% with a roll coater and apply 2g / scale ² , volatilize the solvent, cure the coating by UV irradiation, and polish # 320 A wood board was produced in the same manner as in Example 1 except that it was polished with paper.
<Comparative Example 1>
In Example 1, a wood board was produced in the same manner as in Example 1 except that the two-component aqueous polymer urethane resin was not applied.
<Comparative example 2>
In the same manner as in Example 1, a woody base material that was processed by making was manufactured.

Next, an impregnating sealer diluted with a solvent (UV sealer, manufactured by Capital Paint Co., Ltd., solid content 67%, approximately 90 mPa · s (25 ° C.) in a solvent diluted state) is 2 g / scale using a roll coater. ^After coating ² and evaporating the solvent, the coating was cured by UV irradiation and the surface was polished with # 320 abrasive paper.

Next, a UV curable resin diluted with a solvent (UV sanding A, manufactured by Capital Paint Co., Ltd., 83% solid content, about 150 mPa · s (25 ° C.) in a solvent diluted state) was applied at 4 g / After applying the scale ² , the solvent was volatilized, the coating film was cured by UV irradiation, and the surface was polished with # 400 abrasive paper.

Next, as a top coating, a solvent-free UV curable coating (Aurex 450FC matte, China Paint Co., Ltd., about 1500 mPa · s (25 ° C.)) is applied with 0.7 g / scale ² using a roll coater, A wood board was produced.
<Evaluation>
The wood boards produced in Examples 1 to 7 and Comparative Examples 1 and 2 were subjected to appearance evaluation, stain resistance test, scratch resistance test, and chemical resistance test. In addition, the scratch resistance test of Examples 4-5 was not implemented.
Appearance evaluation: Observe the surface of each wooden board visually, and evaluate the case where the canal remains and wood texture is "○", and the canal is buried and the wood texture is lost as "x" did.
Contamination resistance test: Household seasonings (soy sauce, sauce, mayonnaise, salad oil, ketchup) and beverages (coffee, tea) and ink are soaked in absorbent cotton and placed on the surface of each wooden board. The surface state after 24 hours was put on the watch glass and observed. All the pollutants used in the evaluation had no abnormalities such as discoloration, coloring, blistering, cracking, etc., and they were effective in repelling some of the pollutants. When all the pollutants did not have abnormalities such as discoloration, coloring, blistering, cracking, etc., “◯” was evaluated, and when some abnormalities were observed, “△” was evaluated.
Scratch resistance test: Using a special jig with two coins (new 10-yen coins) attached at an angle, load the special jig and scratch the surface of each wooden board at the edge of the coin. A load when scratches or whitening occurred was measured, and a load of 5.5 kg or more was evaluated as “◯”, and a load of less than 5.5 kg was evaluated as “X”. The greater the measurement load, the better the scratch resistance.
Chemical resistance test: Various household detergents such as acid, alkaline and neutral were soaked in absorbent cotton, placed on the surface of each wooden board, covered with a watch glass, and the surface condition after 24 hours was observed. For all household detergents used for evaluation, “○” when there is no abnormality such as discoloration, coloring, blistering, cracking, etc., some household detergents have abnormalities, and some surface conditions are abnormal. “Δ” was evaluated when “” was observed, and “X” was evaluated when all were abnormal.

  The results are shown in Table 1.

  When the cross section of the wood board produced in Examples 1-7 was observed, the film | membrane by a polymer resin was observed on the surface of the oak veneer 2 in the wood base material 1 like FIG. It was confirmed that it was formed. It was also confirmed that a coating film layer 4 of UV curable resin was formed on the surface of the thin film protective layer 3, and a coating film 5 of top coating was formed thereon. Further, the wood board produced in Example 7 was formed with a thin film protective layer 3, a UV curable resin coating layer 4, and a top coating film 5 in the same manner as in Examples 1 to 3 and 6. In addition, oak It was also confirmed that a resin impregnated hardened layer 6 was formed near the surface of the veneer 2 as shown in FIG. In all of the wood boards of Examples 1 to 7, the road pipe 8 is formed on the surface of the oak veneer 2, but the thin film protective layer 3 and the UV curable resin coating layer 4 on the road pipe 8 are thin. From this, it was confirmed that a good wood texture was revealed, and it was also confirmed that the scratch resistance and chemical resistance were good. Further, in Examples 4 to 5, the coating layer 4 of the fluorine resin or silicone resin is formed, and in Example 6, the coating film 5 of the top coating material of the fluorine resin is formed. It was confirmed that there was an improvement.

  Since the wood board manufactured in Comparative Example 1 is directly coated with UV curable resin on the surface of the oak veneer 2 in the wood base material 1, as shown in FIG. It was confirmed that the impregnated cured layer 7 of the UV curable resin was formed by impregnating the mold resin, and the stable UV curable resin coating layer 4 covering the surface of the oak veneer 2 was not formed. Thereby, it was confirmed that the stain resistance, scratch resistance and chemical resistance were inferior. In Comparative Example 2, as shown in FIG. 3 (b), the coating layer 4 of the UV curable resin is formed on the surface of the oak veneer 2 in the wooden substrate 1, but it is applied to the surface of the oak veneer 2. Since the application amount of the UV curable resin was large, it was confirmed that most of the road pipe 8 on the surface of the oak veneer 2 was buried with the UV curable resin, and the wood texture was impaired.

It is a section schematic diagram of the wood board concerning the embodiment of the present invention. It is a cross-sectional schematic diagram of the wooden board which concerns on another embodiment of this invention. It is a cross-sectional schematic diagram of the wooden board in a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wood base material 2 Oak veneer 3 Thin film protective layer 4 Coating layer 5 Top coat coating 6 Resin impregnation hardening layer 7 UV hardening resin impregnation hardening layer 8 Road pipe

Claims (4)

A thin film protective layer having a thickness of 5 to 50 μm of a polymer resin having an average molecular weight of 10,000 or more is formed on the surface of the wood substrate, and a coating layer is formed by applying a low-viscosity resin thereon and curing it. Wood board characterized by being made.   The wood board according to claim 1, wherein the low-viscosity resin contains a fluorine-based resin or a silicone-based resin.   The wood board according to claim 1 or 2, wherein the thin film protective layer contains a color pigment.   The wooden board according to any one of claims 1 to 3, wherein the surface of the wooden base material is subjected to a sea urchin process.

Images