JP2002337113A - Method for manufacturing coated wood material, and coated wood material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a coated wood material which is excellent in physical properties of a paint film, light resistance of the paint film, adhesion to a substrate of the paint film, adhesion between the paint film layers or productivity of the coated wood material, and provide the coated wood material. SOLUTION: The method for manufacturing the coated wood material 101 is equipped with an electron beam curing process wherein the wood material 102 having a plurality of semi-cured paint films 112, 113, 114 and 115 and an uncured paint film 116 applied onto the paint film 112 and the like is irradiated with an electron beam to cure the uncured paint film 116 and a plurality of the semi-cured paint film 112 and the like under that are also cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a coated wooden material obtained by coating a wooden material and a coated wooden material.

[0002]

2. Description of the Related Art Conventionally, wooden materials have been widely applied for the purpose of protecting the surface of the wooden material and for providing a beautiful appearance to the surface of the wooden material. For painting, discard,
There are coloring, undercoating, intermediate coating, and topcoating. As a method of curing these coating films, a thermosetting method of drying and curing the coating film by, for example, blowing hot air on the coating film, or an ultraviolet curing method of irradiating the coating film with ultraviolet light to cure the coating film is adopted. Have been.

[0003] A concrete description will be given of the case where a wooden material is subjected to discarding, coloring, undercoating, intermediate coating, and topcoating. By irradiating ultraviolet light to the discarded coating film, or by using them together, the discarded coating film is semi-cured. Next, a colored paint is applied on the semi-cured discarded coating film, and then the colored coating film is semi-cured by the above method. In addition, the undercoating film and the intermediate coating film are sequentially formed in the same manner. Thereafter, a top coat is applied on the semi-cured intermediate coat, and the top coat is completely cured by the above method.

[0004]

However, in the thermal curing method and the ultraviolet curing method, the energy used for curing the coating film is relatively low, so that the coating film may not be sufficiently cured. In particular, as in the above-described example, a plurality of semi-cured coating films (discarded coating film, colored coating film, undercoating film and intermediate coating film) are stacked, and finally the outermost surface coating film (overcoating film) In addition, when the entire coating film was cured, the internal coating film was often not sufficiently cured. For this reason, the film strength is low,
There were problems such as abrasion, scratching and cracking on the coating film surface. In addition, because of the low crosslinking density of the cured coating film, the surface of the coating film did not exhibit sufficient stain resistance and chemical resistance. Further, these problems appear remarkably immediately after the coating film is cured, and frequently cause problems during post-processing. That is, when a coating film is formed by a heat curing method or an ultraviolet curing method, there are difficulties in physical properties of the coating film.

[0005] The coating materials used in the heat curing method or the ultraviolet curing method contain, for example, a heat-reactive component such as a quick-drying isocyanate and an ultraviolet-reactive component such as a photoinitiator. That is, even when the coating film is cured, the photosensitizer remains in the coating film, and the light resistance is significantly reduced. In addition, an ultraviolet absorber may be added to the paint for the purpose of preventing scorching of the coated wooden material. However, if this is added, the ultraviolet curing method causes significant curing failure. For this reason, the addition amount of the ultraviolet absorber cannot be increased, and the burn of the coated wooden material cannot be sufficiently suppressed. In other words, the heat curing method or the ultraviolet curing method has difficulty in the light resistance of the coating film.

[0006] Further, the first layer coating film formed on the wood material (for example, a discarded coating film in the above-mentioned example) needs to be penetrated into the base material and cured, and thus contains, for example, a urethane coating material. A method of using a two-part paint and thermally curing the same, or a method of using a two-part paint made of, for example, a paint obtained by mixing an isocyanate in an ultraviolet-curable resin and curing the combined use of heat and ultraviolet light is used. , Has been widely adopted. But,
In such a curing method using a two-part paint, a long drying time is required, and the paint has a limited usable time, so that the efficiency and workability are poor, and moreover, the paint film is hardened. Immediately after curing, the adhesion of the coating film was not sufficiently exhibited.
That is, in the heat curing method or the curing method using both heat and ultraviolet light, the adhesion of the coating film to the substrate is difficult.

[0007] In the thermal curing method and the ultraviolet curing method,
When forming a multi-layer coating film, in order to increase the adhesion between the coating films, it is necessary to set strict curing conditions for the formation of each coating film and to obtain an appropriate semi-cured state. For example, if the underlying coating film is too hard, that is, if it is hardened too much, the adhesion to the coating film on it will be weak and delamination may occur. On the other hand, if the curing of the underlying coating film is too weak, that is, if the curing is insufficient, a part where the curing is insufficient will eventually remain in the coating film, and the physical properties of the coating film deteriorate. That is, it has been difficult to obtain the optimum adhesion between the coating layers by the heat curing method or the ultraviolet curing method.

[0008] In the thermosetting method, the coating film is cured by a low-energy thermal action, so that it takes a long time to cure.
A large drying oven is required for mass production. on the other hand,
In the ultraviolet curing method, much of the input electric power is converted into heat that is not related to curing, so that the electric power consumption is increased more than necessary. In other words, the heat curing method and the ultraviolet curing method have difficulty in the productivity of the painted wooden material.

The present invention has been made in view of the above-mentioned circumstances, and has been made in consideration of the physical properties of a coating film, light resistance of the coating film, adhesion of the coating film to a substrate, adhesion between coating film layers, and coating of a wooden material. An object of the present invention is to provide a method for producing a coated wooden material having excellent productivity and a coated wooden material.

[0010]

Means for Solving the Problems, Action and Effect The solution is a method for producing a coated wooden material obtained by coating a wooden material, wherein the semi-cured first coating film and the first coating film are applied on the first coating film. An electron beam is irradiated to the wooden material having the uncured second coating film to cure the uncured second coating film and the semi-cured first coating film thereunder. This is a method for producing a painted wooden material having a wire curing step.

According to the present invention, in the electron beam curing step, an uncured second surface is irradiated by irradiating an electron beam.
The coating is cured and the underlying semi-cured first coating is also cured. If the coating film is cured using an electron beam, the coating film on the surface to which the electron beam is directly irradiated (second coating film)
Not only that, but also the internal coating film (first coating film) can be completely cured, and crosslinking can be sufficiently completed. It is considered that the energy due to the electron beam is higher than the energy in the case of heat or ultraviolet light. Therefore, the strength of the coating film is high, and the physical properties of the coating film such as abrasion, scratching and cracking on the coating film surface can be improved. Further, the crosslink density of the coating film is high, and the contamination and chemical resistance of the coating film surface can be sufficiently exhibited. Further, the maximum physical properties of the coating film can be exhibited immediately after the production of the coated wooden material. That is, the physical properties of the coating film can be improved.

Also, in the present invention, the semi-cured first coating film inside the coating film is completely cured, so that the first coating film is blended into the first coating film in order to semi-curing with heat or ultraviolet rays. Heat reaction components and ultraviolet reaction components can be reduced. In addition, even if the ultraviolet absorber is incorporated into the paint, curing failure does not occur, so that there is no particular limitation on the amount of addition. Therefore, the light resistance of the coating film is good, and it is possible to sufficiently suppress burns generated in the painted wooden material.

Further, according to the present invention, 1 is formed on a wooden material.
The coating film of the layer can be completely cured by the electron beam. For this reason, by using a one-component paint for forming the first-layer coating film, the drying time can be shortened and the working time can be extended, and the efficiency and workability can be improved. Further, the adhesion between the cured coating film and the wooden material can be sufficiently exhibited immediately after the curing.

In the present invention, the semi-cured first coating film inside the coating film is also completely cured, so that the curing of the first coating film is too weak, that is, the curing is insufficient. In the end, this can be completely cured with an electron beam. Therefore, even if the curing conditions of the first coating film are not strictly set, the insufficiently cured portion will not remain in the coating film, and the physical properties of the coating film will not be reduced. In addition, if care is taken to prevent the first coating film from being excessively hardened, that is, to prevent the hardening from proceeding more than necessary, the adhesion between the coating film layers can be improved. For this reason, there is no need to make the curing conditions of the first coating film too strict.

The curing of the coating film by the irradiation of the electron beam is as follows.
High-speed processing is possible as compared with the thermal curing method or the ultraviolet curing method, and high irradiation energy can be obtained with a small amount of electricity consumption.

Further, in the above method for producing a coated wooden material, it is preferable that the second coating film is a method for producing a coated wooden material which is a coating film that forms the outermost surface of the coated wooden material.

According to the above-mentioned invention, after the first and second coating films are cured in the electron beam curing step, 1 second coating film is further applied on the second coating film.
Layers or multiple layers of coatings can also be formed. In this case, if a conventional heat curing method or ultraviolet curing method is employed to cure the coating film applied on the second coating film, the problem described in the conventional problem may occur. On the other hand, in the present invention, the second coating film to be cured in the electron beam curing step is a coating film that forms the outermost surface of a painted wooden material as a final product. Therefore, it is possible to produce a coated wood material which is more excellent in physical properties of the coating film, light resistance of the coating film, adhesion of the coating film to the substrate, adhesion between the coating layers, and productivity of the coated wood material.

Further, in the method for producing a coated wooden material according to any one of the above, it is preferable that the semi-cured first coating film is a method for producing a coated wooden material that is semi-cured by irradiation of ultraviolet rays. .

When the first coating film is semi-cured by the thermosetting method, it generally takes time to semi-cure the coating film. In addition, the production line becomes longer. In contrast, in the present invention, the first
Since the coating film is semi-cured by the ultraviolet curing method, the time for semi-curing the first coating film can be shortened, and the productivity can be further improved.

Further, in the method for producing a coated wooden material according to any one of the above, the semi-cured first coating film is a method for producing a coated wooden material in which a plurality of semi-cured coating films are overlapped. Good.

In order to improve the physical properties and appearance of the coated wooden material, it is preferable to apply the coating in such a manner that a plurality of coating films are laminated on the wooden material. In particular, it is preferable to form a state in which the plurality of coating films are laminated in a state of being semi-cured, and then to cure the film. In the present invention, since the first coating film is formed by overlapping a plurality of semi-cured coating films, the physical properties and appearance of the painted wooden material can be particularly improved.

Another solution is a method for producing a coated wooden material obtained by coating a wooden material, the method comprising applying a waste paint to the wooden material, and applying an ultraviolet ray to the paint film of the waste paint. Irradiating, and a semi-curing step of semi-curing the discarded coating film, a coloring step of applying a coloring paint on the semi-cured discarded coating film, and applying ultraviolet rays to the coating film of the coloring paint. Irradiate,
A semi-curing step of semi-curing the colored coating, a sub-coating step of applying a sub-coat on the semi-cured colored coating, and irradiating the coating of the under coating with ultraviolet light, Undercoat semi-curing step of semi-curing, an intermediate coating step of applying an intermediate coating on the semi-cured undercoat coating, and irradiating the coating of the intermediate coating with ultraviolet light to semi-cure the intermediate coating. An intermediate coating semi-curing step, a top coating step of applying a top coating on the semi-cured intermediate coating film, and irradiating the coating of the top coating with an electron beam to cure the top coating and And an electron beam curing step of also curing the semi-cured intermediate coating film, undercoat film, colored coating film and discarded coating film.

According to the present invention, not only the top coat which is directly irradiated with the electron beam by the electron beam, but also the inner coat (intermediate coat, undercoat, colored coat and discard coat). Can be completely cured, and crosslinking can be sufficiently performed. Therefore, the strength of the coating film is high, and the physical properties of the coating film such as abrasion, scratching and cracking on the coating film surface can be improved. Further, the crosslink density of the coating film is high, and the contamination and chemical resistance of the coating film surface can be sufficiently exhibited. Further, the maximum physical properties of the coating film can be exhibited immediately after the production of the coated wooden material. That is, the physical properties of the coating film can be improved.

In the above invention, the semi-cured coatings (intermediate coating, undercoating, colored coating, and discarded coating) inside are completely cured by an electron beam. The heat-reactive component and the UV-reactive component to be incorporated in these coating films for semi-curing with UV light or ultraviolet light can be reduced. Therefore, the light resistance of the coating film can be improved. Even if an ultraviolet absorber is incorporated into the coating, each coating film can be completely cured by an electron beam regardless of the ultraviolet absorber, and curing failure does not occur. Instead, the amount of the ultraviolet absorber added may be larger than usual (for example, 1% or more). If you do this,
Furthermore, the light resistance of the coating film is improved, and burns generated in the painted wooden material can be sufficiently suppressed.

In the above invention, the discarded coating film which comes into direct contact with the wooden material is completely cured by the electron beam. For this reason, a one-component paint can be used for forming a discarded coating film, so that the drying time can be shortened and the working time can be extended, and the efficiency and workability can be improved. Can be. By using an electron beam, a discarded coating film that has penetrated wood material can be surely cured. In addition, the adhesion between the hardened waste coating film and the wooden material can be sufficiently increased immediately after the hardening.

In the above invention, the semi-cured coating films (intermediate coating film, undercoating film, colored coating film, and discarded coating film) are completely cured by an electron beam. Is too weak, that is, even if the curing is insufficient, it can be finally completely cured with an electron beam. Therefore, even if the curing conditions of the internal coating film are not strictly set, the insufficiently cured portion is finally left in the coating film, and the physical properties of the coating film are not deteriorated. Also, if care is taken not to cure too much, good adhesion between coating layers can be obtained. Thus, setting of the curing conditions in the semi-curing step of each coating film is also facilitated. In particular, in the present invention, the lower layer of the colored coating, after the formation of the colored coating, UV curing can not be cured afterwards, the discarded coating, once in close contact with the colored coating in a semi-cured state, It can be completely cured by an electron beam curing process. Therefore, the adhesion between the discarded coating film and the colored coating film can be improved.

The curing of the coating film by the irradiation of the electron beam is as follows.
High-speed processing is possible as compared with the thermal curing method or the ultraviolet curing method, and high irradiation energy can be obtained with a small amount of electricity consumption.

In the above-mentioned invention, the top coat cured in the electron beam curing step is the coat that forms the outermost surface of the painted wooden material as the final product. Therefore, it is possible to produce a coated wood material which is more excellent in physical properties of the coating film, light resistance of the coating film, adhesion of the coating film to the substrate, adhesion between the coating layers, and productivity of the coated wood material.

In the above invention, the semi-cured coatings (intermediate coating, undercoating, colored coating and discarded coating) inside are semi-cured by ultraviolet rays. Curing time can be shortened, and productivity can be further improved. In particular, in the present invention, since the inner coating film is also completely cured in the electron beam curing step, it is sufficient for all the inner coating films to be semi-cured to a touch-dry (so-called tack-free) state. In particular, the amount of the photoinitiator contained in the inner coating film can be made smaller than usual (for example, 1 part by weight or less). Further, by forming the next coating film to the extent of dryness to the touch, the adhesion between the coating films can be further increased. That is, it is more preferable that the film is semi-cured to a touch-dry state in the half-curing step of the coating, the semi-curing step of the coloring, the semi-curing step of the undercoating, and the semi-curing step of the intermediate coating. Further, in the above invention, four layers of an intermediate coating film, an undercoat coating film, a colored coating film, and a discarded coating film are formed as semi-cured coating films inside, and each coating film inside is once semi-cured. Since the next coating film is formed after this, the physical properties and appearance of the painted wooden material can be particularly improved.

Still another solution is a method for producing a coated wooden material in which a wooden material is applied. The method includes the steps of applying a waste paint to the wooden material, and applying ultraviolet light to the paint film of the waste paint. Irradiation, a semi-curing step of semi-curing the discarded coating film, a coloring step of applying a coloring paint on the semi-cured discarded coating film, and heating the coating film of the coloring paint A thermosetting step of drying and curing the colored coating film, an undercoating step of applying an undercoat paint on the cured colored coating film, and irradiating the undercoat paint film with ultraviolet light to obtain an undercoat paint film. Undercoat semi-curing step of semi-curing, an intermediate coating step of applying an intermediate coating on the semi-cured undercoat coating, and irradiating the coating of the intermediate coating with ultraviolet light to semi-cure the intermediate coating. Intermediate coating semi-curing process and top coating for applying a top coating on the semi-cured intermediate coating film And irradiating the coating film of the top coating with an electron beam to cure the top coating, and also to cure the semi-cured intermediate coating, undercoat and discard coating under it. And a process for producing a coated wooden material.

According to the present invention, not only the top coat which is directly irradiated with the electron beam by the electron beam, but also the inner coats (intermediate coat, undercoat, and discard coat) are completely cured. And crosslinking can be sufficiently performed. Therefore,
The coating film strength is high, and the physical properties of the coating film such as abrasion, scratching and cracking on the coating surface are good. Also,
The crosslink density of the coating film is high, and the contamination and chemical resistance of the coating film surface are good. Further, the maximum physical properties of the coating film can be exhibited immediately after the production of the coated wooden material. That is, the physical properties of the coating film can be improved.

Further, in the above invention, the semi-cured coating film (intermediate coating film, undercoating film, and discarded coating film) is completely cured with an electron beam. The heat-reactive component and the UV-reactive component to be incorporated into these coating films for semi-curing can be reduced. Therefore, the light resistance of the coating film can be improved. In addition, even if the ultraviolet absorber is blended in the paint, each coating film can be completely cured by the electron beam regardless of the ultraviolet absorber,
Since curing failure does not occur, there is no particular limitation on the addition amount, and the addition amount of the ultraviolet absorber is larger than usual (for example, 1%
Above). In this case, the light resistance of the coating film is further improved, and burns generated in the coated wooden material can be sufficiently suppressed.

[0033] In the above invention, the discarded coating film that is in direct contact with the wooden material is also completely cured by the electron beam. For this reason, since a one-part paint can be used for forming a discarded coating film,
Efficiency and workability can be improved by shortening the drying time or extending the pot life. By using an electron beam, a discarded coating film that has penetrated wood material can be surely cured. In addition, the adhesion between the hardened waste coating film and the wooden material can be sufficiently increased immediately after the hardening.

In the above invention, the semi-cured coating films (intermediate coating film, undercoating film, and discarded coating film) are completely cured by an electron beam, so that the curing of these coating films is insufficient. However, it can be finally completely cured. Therefore,
Even without strictly setting the curing conditions for these internal coatings,
Insufficiently cured portions are finally left in the coating film, and the physical properties of the coating film do not deteriorate. Also, if care is taken not to cure too much, good adhesion between coating layers can be obtained. Thus, setting of the curing conditions in the semi-curing step of each coating film is also facilitated. In particular, in the present invention, the lower layer of the colored coating, after the formation of the colored coating, UV curing can not be cured afterwards, the discarded coating, once in close contact with the colored coating in a semi-cured state, It can be completely cured by an electron beam curing process. Therefore, the adhesion between the discarded coating film and the colored coating film can be improved.

The curing of the coating film by the irradiation of the electron beam is as follows.
High-speed processing is possible as compared with the thermal curing method or the ultraviolet curing method, and high irradiation energy can be obtained with a small amount of electricity consumption.

In the above invention, the top coat cured in the electron beam curing step is the outermost surface of the coated wood material as the final product. Therefore, it is possible to produce a coated wood material which is more excellent in physical properties of the coating film, light resistance of the coating film, adhesion of the coating film to the substrate, adhesion between the coating layers, and productivity of the coated wood material.

In the above invention, the semi-cured coating films (intermediate coating film, undercoating film, and discarded coating film) are semi-cured by ultraviolet rays. Can be shortened, and the productivity can be further improved. In particular, in the present invention, since the inner coating film is also completely cured in the electron beam curing step, the inner coating film only needs to be semi-cured to a touch-dry (so-called tack-free) state. The amount of the photoinitiator contained in the coating film may be smaller than usual (for example, 1 part by weight or less). Further, by forming the next coating film to the extent of dryness to the touch, the adhesion between the coating films can be further increased. That is, it is more preferable that the film is semi-cured to a touch-dry state in the semi-curing step, the semi-curing step, and the semi-curing step. Further, in the above invention, since the inner semi-cured coating film has four layers of an intermediate coating film, a primer coating film, a colored coating film, and a discarded coating film, the physical properties and appearance of the painted wood material are improved. In particular, it can be improved. In particular, middle coat, undercoat,
In addition, since the next coating film is formed after the semi-cured coating film is once cured, the physical properties and appearance of the coated wooden material can be particularly improved.

Still another solution is a method for producing a coated wooden material in which a wooden material is applied, wherein a coloring step of applying a coloring paint to the wooden material, and irradiating the coating film of the coloring paint with ultraviolet rays. A semi-curing step of semi-curing the colored coating, a sub-coating step of applying an undercoat on the semi-cured colored coating, and an inter-coating step of applying an intermediate coating on the coating of the under coating. Irradiating ultraviolet rays to the coating film of the intermediate coating, an intermediate coating / undercoating semi-curing step of semi-curing the intermediate coating film and the undercoating film thereunder, and a top coating paint on the semi-cured intermediate coating film A topcoating step of applying the above, and irradiating the coating of the above topcoat with an electron beam to cure this topcoat, and also cure the semi-cured middlecoat, undercoat and colored coating thereunder. And a method of producing a coated wooden material.

According to the present invention, not only the top coat which is directly irradiated with the electron beam by the electron beam, but also the inner coat (intermediate coat, undercoat, and colored coat) is completely cured. And crosslinking can be sufficiently performed. Therefore, the strength of the coating film is high, and the physical properties of the coating film such as abrasion, scratching and cracking on the coating film surface are good. Further, the crosslink density of the coating film is high, and the contamination and chemical resistance of the coating film surface are good. Further, the maximum physical properties of the coating film can be exhibited immediately after the production of the coated wooden material. That is, the physical properties of the coating film can be improved.

In the above invention, the semi-cured coating films (intermediate coating film, undercoating film, and colored coating film) are completely cured with an electron beam. It is possible to reduce the amount of heat-reactive components and UV-reactive components to be incorporated into these coatings for curing. Therefore, the light resistance of the coating film can be improved. In addition, even if the ultraviolet absorber is blended in the paint, each coating film can be completely cured by the electron beam regardless of the ultraviolet absorber,
Since curing failure does not occur, there is no particular limitation on the addition amount, and the addition amount of the ultraviolet absorber is larger than usual (for example, 1%
Above). In this case, the light resistance of the coating film is further improved, and burns generated in the coated wooden material can be sufficiently suppressed.

Further, in the above invention, the colored coating film which is in direct contact with the wooden material is completely cured by the electron beam. For this reason, since a one-component paint can be used for forming a colored coating film,
Efficiency and workability can be improved by shortening the drying time or extending the pot life. Further, the adhesion between the cured colored coating film and the wooden material can be sufficiently increased immediately after the curing.

In the above invention, the semi-cured coating films (intermediate coating film, undercoat coating film, and colored coating film) are completely cured by an electron beam, so that these coating films are insufficiently cured. Even if it does, it can be finally completely cured. Therefore,
Even without strictly setting the curing conditions for these internal coatings,
Insufficiently cured portions are finally left in the coating film, and the physical properties of the coating film do not deteriorate. Also, if care is taken not to cure too much, good adhesion between coating layers can be obtained. Thus, setting of the curing conditions in the semi-curing step of each coating film is also facilitated.

The curing of the coating film by the irradiation of the electron beam is as follows.
High-speed processing is possible as compared with the thermal curing method or the ultraviolet curing method, and high irradiation energy can be obtained with a small amount of electricity consumption.

Further, in the above invention, the top coat to be cured in the electron beam curing step is a coat that forms the outermost surface of the coated wooden material as the final product. Therefore, it is possible to produce a coated wood material which is more excellent in physical properties of the coating film, light resistance of the coating film, adhesion of the coating film to the substrate, adhesion between the coating layers, and productivity of the coated wood material.

In the above invention, the semi-cured coating films (intermediate coating film, undercoat coating film, and colored coating film) are semi-cured by ultraviolet rays. It can be shortened, and the productivity can be further improved. In particular, in the present invention, since the inner coating film is also completely cured in the electron beam curing step, the inner coating film only needs to be semi-cured to a touch-dry (so-called tack-free) state. The amount of the photoinitiator contained in the coating film may be smaller than usual (for example, 1 part by weight or less). Further, by forming the next coating film to the extent of dryness to the touch, the adhesion between the coating films can be further increased. That is, in the coloring semi-curing step, the undercoat / intermediate semi-curing step,
It is more preferable that the composition is semi-cured to the touch-dry state. Further, in the above invention, as the internal coating film, the intermediate coating film, the undercoat coating film, and the colored coating film are formed, so that the physical properties of the painted wood material are good, Since no semi-curing step of the intermediate coating film is provided, the cost can be reduced.

Alternatively, another solution is a method for producing a coated wood material in which a wood material is applied, wherein a coloring step of applying a coloring paint to the wood material, and heating the coating film of the coloring paint, A thermosetting step of drying and curing the colored coating film,
An undercoating step of applying an undercoat on the cured colored coating film, an intermediate coating step of applying an intermediate coating on the undercoat coating film, and irradiating the intermediate coating film with ultraviolet light, A semi-curing / undercoating semi-curing step of semi-curing the coating film and the undercoating film thereunder, a top-coating step of applying a top-coating material on the semi-cured intermediate coating film, and an electron beam And an electron beam curing step of curing the semi-cured intermediate coat film and the undercoat film under the film while curing the top coat film.

According to the present invention, not only the top coat which is directly irradiated with the electron beam by the electron beam but also the inner coat (intermediate coat and undercoat) can be completely cured. In addition, crosslinking can be sufficiently performed. Therefore, the coating film strength is high, the abrasion property on the coating film surface, the scratch property,
Good physical properties of the coating film such as cracking property. Further, the crosslink density of the coating film is high, and the contamination and chemical resistance of the coating film surface are good. Further, the maximum physical properties of the coating film can be exhibited immediately after the production of the coated wooden material. That is, the physical properties of the coating film can be improved.

In the above invention, since the semi-cured coating films (intermediate coating film and undercoating film) inside are completely cured by an electron beam, it is necessary to semi-curing these coating films by heat or ultraviolet rays. It is possible to reduce the amount of heat-reactive components and UV-reactive components contained in these coating films. Therefore, the light resistance of the coating film can be improved. Even if an ultraviolet absorber is incorporated into the coating, each coating film can be completely cured by an electron beam regardless of the ultraviolet absorber, and curing failure does not occur. Instead, the amount of the ultraviolet absorber added may be larger than usual (for example, 1% or more). In this case, the light resistance of the coating film is further improved, and burns generated in the coated wooden material can be sufficiently suppressed.

In the above invention, the semi-cured coating films (intermediate coating film and undercoating film) inside are completely cured by an electron beam. Therefore, even if these coating films are insufficiently cured, Finally, it can be completely cured. Therefore, even if the curing conditions of the internal coating film are not strictly set, the insufficiently cured portion is finally left in the coating film, and the physical properties of the coating film are not deteriorated. Also, if care is taken not to cure too much, good adhesion between coating layers can be obtained. Thus, setting of the curing conditions in the semi-curing step of each coating film is also facilitated.

The curing of the coating film by electron beam irradiation is as follows.
High-speed processing is possible as compared with the thermal curing method or the ultraviolet curing method, and high irradiation energy can be obtained with a small amount of electricity consumption.

Further, in the above invention, the topcoat film cured in the electron beam curing step is a film forming the outermost surface of the painted wooden material as the final product. Therefore, it is possible to produce a coated wood material which is more excellent in physical properties of the coating film, light resistance of the coating film, adhesion of the coating film to the substrate, adhesion between the coating layers, and productivity of the coated wood material.

Further, in the above invention, since the semi-cured coating films (intermediate coating film and undercoat coating film) inside are semi-cured by ultraviolet rays, it is possible to shorten the time for semi-curing these coating films. And productivity can be further improved. In particular, in the present invention, since the inner coating film is also completely cured in the electron beam curing step, it is sufficient for all the inner coating films to be semi-cured to a touch-dry (so-called tack-free) state. In particular, the amount of the photoinitiator contained in the inner coating film can be made smaller than usual (for example, 1 part by weight or less). Furthermore, by forming the top coat in a state where the middle coat is cured to the extent of touch-drying, the adhesion between the middle coat and the top coat can be further improved. That is,
In the intermediate coating semi-curing step, it is more preferable to semi-cur to a touch-dry state. In the above invention, since three layers of the inner coating film, the undercoat coating film, and the colored coating film are formed as the inner coating film, the physical properties of the coated wood material are good,
Since it does not include a semi-curing step of the discarded coating film and the intermediate coating film, the cost can be reduced.

Another solution is a coated wooden material obtained by coating a wooden material, wherein the coating film is cured by irradiation with an electron beam.
In the adhesion test described in 5400, 100 squares (= 10 × 10) of 2 mm squares were prepared according to the square grid tape method, and the adhesive tape was peeled off and peeled off. Is a coated wooden material having an initial adhesion of 5% or less of the entire area.

According to the present invention, the coated wood material already has sufficiently high adhesion to the coating film immediately after the coating film is cured by an electron beam (immediately after the production of the coated wood material). Specifically, according to the grid tape method of the adhesion test described in JIS-K5400, 100 grids of 2 mm square (=
10 × 10), and when the adhesive tape was peeled off and peeled off, the area where the coating film was peeled was 5% or less of the entire area. Since such painted wood material has sufficiently exhibited the physical properties of the coating film immediately after production, after the painted wood material production, without leaving it for a certain period of time, it can be shipped or easily processed thereafter. be able to.

[0055]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a partially enlarged cross-sectional view of the coated wooden material 101 of the first embodiment. The painted wooden material 101 is one in which the entire surface of the wooden material 102 is painted. Its size is about 30cm x about 180c
It has a substantially plate shape of mx about 1.2 cm.

The wood material 102 has a thickness of about 1.0 to
A decorative veneer (0.3 mm) is provided on the surface of a base plywood obtained by laminating a plurality of layers of 3.0 mm lauan veneers alternately vertically and horizontally.
This is a decorative plywood with a veneer veneer. On the other hand, the coating film 111 formed on the entire surface of one side of the wooden material 102 includes a discarded coating film 112 formed directly on the wooden material 102, a colored coating film 113 formed thereon, and further formed thereon. An undercoating film 114, an intermediate coating film 115 further formed thereon, and a topcoating film 116 further formed thereon. The discarded coating film 112 is composed of the wooden material 102 and the coating film 11.
1 to improve the adhesion to
It is formed in order to make wood grain etc. which stand out. The colored coating film 113 is mainly formed by filling a conduit, a groove, or the like on the surface of the wooden material 102 to make the wooden material look more beautiful by highlighting the grain of the wooden material 102. The undercoat 114 is formed on the colored coating 113 and the like in order to improve the adhesion with the colored coating 113 and the like. The intermediate coat 115 is formed on the undercoat 114 in order to improve the abrasion resistance and the like of the painted wooden material 101. The top coat 116 is formed on the middle coat 115 in order to make the appearance of the painted wooden material 101 more beautiful.

Immediately after the coating 111 is cured (immediately after the production of the coating 101), the adhesion of the coating 111 is already high. Specifically, of the adhesiveness described in JIS-K5400, 100 squares of 2 mm square (= 1) according to the square tape method.
0 × 10), when the adhesive tape is peeled off and peeled off, good adhesion is obtained in which the peeled area of the coating film 111 is 5% or less of the entire area. Such a painted wooden material 10
No. 1 shows the physical properties of the coating film 111 sufficiently immediately after the production, so that the production or subsequent processing can be performed without leaving the coated wood material 101 for a certain period of time after the production.

Next, a method of manufacturing the above-described coated wooden material 101 will be described. In addition, the outline of the manufacturing process of each embodiment and each comparative embodiment described below is collectively described in FIG.

First, the surface of the wooden material 102 is
Polish with sandpaper. Then, in the disposing step, a disposing paint is applied to the wooden material 102. Specifically, a disposable paint (IST No. 1 manufactured by Natco Co., Ltd.)
50) is applied to the entire surface of one side of the wooden material 102 by a rubber natural roll coater. Part of the waste paint applied to the wooden material 102 penetrates the wooden material 102. This base coat paint (IST No. 150) has a base resin made of urethane acrylate, and contains 1 part by weight of a photoinitiator with respect to 100 parts by weight of the base resin. After that, in the discarding semi-curing step, the discarded coating film 112 is irradiated with ultraviolet rays to be semi-cured. Specifically, the discarded coating film 112 is irradiated with 60 mJ / cm ² of ultraviolet light by an ultraviolet irradiation dryer, so that the discarded coating film 112 is semi-cured.

Next, in the coloring step, a colored paint is applied on the semi-cured discarded coating film 112. Specifically, a coloring paint (Natco Co., Ltd. aqueous UV stain) is applied with a sponge natural roll coater, a part thereof is scraped off with a steel oyster roll coater, and further applied with a rubber natural roll coater. . The applied coloring paint is mainly filled in concave portions such as conduits and grooves on the surface of the wooden material 101. This colored paint (water-based UV stain)
The base resin is made of ester acrylate, and 1 part by weight of a photoinitiator is mixed with 100 parts by weight of the base resin. Then, in the coloring semi-curing step, the colored coating film 113 is irradiated with ultraviolet rays to be semi-cured. Specifically, the colored coating film 113 is dried by an ultraviolet irradiation dryer.
Is irradiated with ultraviolet rays of 60 mJ / cm ² , and the colored coating film 113 is semi-cured to a touch-dry state.

Next, in the undercoating step, an undercoat paint is applied on the semi-cured colored coating film 113. Specifically, an undercoat paint (IST No. 350, manufactured by Natco Corporation) is applied with a rubber natural roll coater, and the excess paint is scraped off with a steel oyster roll coater. In this undercoat paint (IST No. 350), the base resin is made of urethane acrylate, and the base resin 10
One part by weight of the photoinitiator is mixed with 0 part by weight.
Thereafter, in the undercoat semi-curing step, the undercoat film 114 is irradiated with ultraviolet rays to be semi-cured. Specifically, the undercoating film 114 is applied to the undercoating film 114 with an ultraviolet irradiation dryer at 60 mJ.
The undercoating film 114 is semi-cured to a touch-dry state by irradiating ultraviolet rays of / cm ² .

Next, in the intermediate coating step, an intermediate coating is applied on the semi-cured undercoat 114. Specifically, an intermediate coating material (IST No. 450 manufactured by Natco Corporation) is applied by passing twice through a rubber natural roll coater. In this intermediate coating (IST No. 450), the base resin is made of ester acrylate, and 1 part by weight of a photoinitiator is blended with 100 parts by weight of the base resin. Thereafter, in the intermediate coating semi-curing step, the intermediate coating film 115 is irradiated with ultraviolet rays to be semi-cured. Specifically, 60 mJ / c is applied to the intermediate coating film 115 by an ultraviolet irradiation dryer.
The intermediate coating film 115 is semi-cured to the touch-dry state by irradiating ultraviolet rays of m ² .

Next, in the polishing step, the surface of the coating film formed on the wooden material 102 is polished using sandpaper # 320. This polishing is performed to make the appearance of the paint look more beautiful. This is because when the intermediate coating film 114 is semi-cured, the surface of the coating film is fluffy and uneven.

Next, in the topcoating step, a topcoat is applied on the semi-cured intermediate coating film 115. Specifically, a top coat (IST No. 550, manufactured by Natco Corporation) is applied by passing through a rubber natural roll coater twice. Or you may apply using a curtain flow coater. In this top coat (IST No. 550), the base resin is made of ester acrylate. In this paint,
No photoinitiator is incorporated. Thereafter, in an electron beam curing step, the top coat 116 is irradiated with an electron beam to cure the top coat 116 and, at the same time, a semi-cured intermediate coat 115, an undercoat 114, and a colored coat 113 thereunder. The hard coating 112 is also cured. Specifically, using an electron beam irradiation dryer (manufactured by Nissin High Voltage Co., Ltd.), the irradiation conditions were set to an acceleration voltage of 300 keV and an electron dose of 50
It is set to kGy (= 5 Mrad) and the electron beam is irradiated toward the top coat 116. In this way, the painted wooden material 10
1 is completed.

According to such a manufacturing method, not only the top coat 116 to which the electron beam is directly irradiated but also the inner coats (the middle coat 115, the undercoat 114, the colored coat 113, and the discard coat). The film 112) can also be completely cured,
Crosslinking can also be performed sufficiently. Therefore, the coating film 111
And the physical properties of the coating film 111 such as abrasion, scratching, and cracking on the surface of the coating 111 can be improved. Further, the crosslinking density is high, and the coating film 111
Can also sufficiently exhibit surface contamination, chemical resistance, and the like. In addition, immediately after the production of the painted wooden material 101,
1 can exhibit the maximum physical properties. That is, the physical properties of the coating film 111 can be improved.

Also, the semi-cured coatings (intermediate coating 115, undercoat 114, colored coating 113 and discarded coating 112) inside the coating 111 are completely cured by electron beams. Therefore, because these coatings are semi-cured by heat or ultraviolet light,
It is possible to reduce the amount of UV-reactive components such as a heat-reactive component and a photoinitiator to be incorporated in these coating films (see Comparative Embodiments 1 and 2 described later). Therefore, a decrease in light resistance due to these components can be suppressed. It should be noted that even if the ultraviolet absorber is incorporated into the coating material, the curing failure does not occur, so that there is no particular limitation on the amount of addition. Therefore, for example, a paint such as a base coat or a middle coat is coated with an ultraviolet absorber in an amount larger than usual (for example, 1
%), A coating film can be formed without any problem,
Moreover, in particular, it is possible to provide a coated wood material in which the light resistance of the coating film 111 is good and burns generated in the coated wood material 101 can be sufficiently suppressed.

Further, the discarded coating film 112 formed directly on the wooden material 102 includes the portion that has penetrated into the wooden material,
It can be completely cured by electron beams. For this reason, since it is not necessary to give the thermosetting property as the discarded coating film 112, a one-component discarded paint can be used for forming the discarded coating film 112, and the drying time can be reduced. Or the working time can be extended, and the efficiency and workability can be improved. In addition, the adhesion between the hardened discarded coating film 112 and the wooden material 102 can be sufficiently exhibited immediately after the hardening.

Further, the semi-cured coating film (intermediate coating film 115, undercoat coating film 114, colored coating film 113, and discarded coating film 112) inside the coating film 111 is completely cured by an electron beam.
Even if these coatings are insufficiently cured, they can eventually be completely cured with an electron beam. Therefore, a portion that is insufficiently cured remains in the coating film 111 and the physical properties of the coating film 111 do not deteriorate. Also, if care is taken not to advance too much, the adhesion between the layers of the coating film 111 can be kept good. Therefore, it is not necessary to strictly set the curing conditions for each of the coating films (intermediate coating film 115 and the like) inside these, and each coating film can be easily semi-cured.

The curing of the coating film 111 by irradiation with an electron beam can be performed at a higher speed than that of a thermal curing method or an ultraviolet curing method, and a high irradiation energy can be obtained with a small electric power consumption. .

Further, in the first embodiment, the top coat 116 to be cured in the electron beam curing step is a coat that forms the outermost surface of the painted wooden material 1 as a final product. Therefore, there is no need to further form a coating film thereon and to cure it with heat, ultraviolet light, or the like, so that problems such as deterioration in physical properties of the coating film, which have conventionally occurred, do not occur. In addition, in the semi-curing step of coating, the semi-curing step of coloring, the semi-curing step of undercoating, and the semi-curing step of intermediate coating, the coating film is semi-cured by an ultraviolet curing method. Therefore, each coating film can be semi-cured in a shorter time than in the case of using a thermosetting method, and the production line can be shortened. In the first embodiment, a plurality of layers of coating films are formed on the wooden material 102. Moreover, each coating film is superposed in a semi-cured state. Therefore, the physical properties and appearance of the painted wooden material 101 can be further improved.

(Embodiment 2) Next, a second embodiment will be described. The description of the same parts as in the first embodiment will be omitted or simplified. See FIG. 5 for the outline of each step. Painted wooden material 201 of the second embodiment
Also, as shown in FIG.
02, paint film 112, colored film 213, undercoat film 11
4. Coating film 21 consisting of intermediate coating film 115 and top coating film 116
1 is formed. However, among these, the colored coating film 213
Are formed not by an ultraviolet curing method but by a thermosetting method. Other portions are the same as those in the first embodiment, and have the same functions and effects.

A method for manufacturing the coated wooden material 201 according to the second embodiment will be described. The discarding process and the semi-curing process are
In the same manner as in the first embodiment, a semi-cured discarded coating film 112 is formed on the wooden material 102. Next, in the coloring step,
A colored paint is applied on the semi-cured discarded coating film 112. Specifically, an aqueous stain manufactured by Natco Co., Ltd. is used as a colored paint, and is applied by a sponge natural roll coater, a steel oyster roll coater, or a rubber natural roll coater. This colored paint (water-based stain)
The base resin is made of acrylic. Thereafter, in a heat curing step, the colored coating film 213 is heated, dried and cured. Specifically, the colored coating film 21 was heated at 100 ° C. for 1 minute by an electronic jet drier.
3 is cured. In this step, unlike the first embodiment, the colored coating film 213 is almost completely cured.

Thereafter, in the same manner as in the first embodiment, an undercoating step, an undercoating semi-curing step, an intermediate coating step, an intermediate coating semi-curing step, a polishing step and a topcoating step are performed, and further, an electron beam irradiation step is performed. In the electron beam irradiation step, the top coat 116 is cured, and the semi-cured intermediate coat 115, undercoat 114, and discarded coat 112 are also cured. Even if the coated wooden material 201 is manufactured by such a method, the above-described Embodiment 1
Similarly to the above, it is possible to obtain a coated wooden material 201 excellent in physical properties of the coating film 211, light resistance of the coating film 211, adhesion to the base material of the coating film 211, adhesion between the layers of the coating film 211, or productivity. it can. Note that the painted wooden material 201 of the second embodiment is used.
Although the finished appearance is not inferior to that of the first embodiment, the cost is slightly increased because the colored coating film is dried and cured by heat.

(Embodiment 3) Next, a third embodiment will be described. The description of the same parts as in the first or second embodiment will be omitted or simplified. See FIG. 5 for the outline of each step. As shown in the partially enlarged cross-sectional view of FIG. 3, the painted wood material 301 of the third embodiment does not have a discarded paint film, and has a colored paint film 113, an undercoat paint film 114, an intermediate paint film 115, and a top paint film 116. Coating film 311 consisting of four layers
Are formed. On the other hand, in the manufacturing method, not only are there no steps related to the formation of the coating film, but also the method of forming the undercoating film 114 and the intermediate coating film 115 is different from those of the first and second embodiments. Other portions are the same as those in the first embodiment, and have the same functions and effects.

A method of manufacturing the coated wooden material 301 according to the third embodiment will be described. The surface of the wooden material 102 is polished in advance and transported to a place where a coloring process is performed. That is,
In the third embodiment, the disposing step and the semi-curing step are not performed. Then, in the same manner as in the first embodiment, a coloring step and a coloring semi-curing step are performed to form a semi-cured colored coating film 113 on the wooden material 102.

Next, in the undercoating step, in the first embodiment,
Similarly, the undercoat is applied on the semi-cured colored coating film 113. Thereafter, the undercoating semi-curing step is not performed, and the process proceeds to the intermediate coating step as it is. The intermediate coating process is the same as in the first embodiment.
Perform in the same manner as described above. Next, in the intermediate coating / undercoat semi-curing process,
The intermediate coating film 115 is irradiated with ultraviolet rays,
5 and the undercoat 114 below it are simultaneously semi-cured.
Specifically, the intermediate coat 1
15 is irradiated with 60 mJ / cm ² of ultraviolet light to apply the intermediate coating film 1
15 and the undercoat 114 are semi-cured.

After that, when the respective steps (polishing step, topcoating step, electron beam irradiation step) are performed in the same manner as in the first embodiment, the coated wooden material 301 is completed. Even when the painted wood material 301 is manufactured by such a method, the physical properties of the coating film 311, the light resistance of the coating film 311,
1, the adhesion to the substrate, the adhesion between the layers of the coating film 311,
Alternatively, it is possible to obtain a coated wooden material 301 having excellent productivity. Note that the painted wood material 301 of the third embodiment has a slightly inferior finish appearance as compared to the first and second embodiments, but does not form a discarded coating film and eliminates the undercoat semi-curing step. It can be manufactured at low cost.

(Embodiment 4) Next, a fourth embodiment will be described. The description of the same parts as in any of the first to third embodiments will be omitted or simplified. Also,
Please refer to FIG. 5 for the outline of each step. The coated wood material 401 of the fourth embodiment has the same structure as the third embodiment.
02, colored coating film 213, undercoating film 114, intermediate coating film 11
A coating film 411 composed of four layers of No. 5 and a top coating film 116 is formed. However, among them, the colored coating film 213 is formed by a thermosetting method as in the second embodiment. Other portions are the same as those in the third embodiment, and have the same functions and effects.

A method for manufacturing the coated wooden material 401 according to the fourth embodiment will be described. First, in the coloring step, a coloring paint is applied to the wooden material 102. Specifically, in the same manner as in the second embodiment, a water-based stain manufactured by Natco Corporation is used as a coloring paint, and is applied by a sponge natural roll coater, a steel oyster roll coater, or a rubber natural roll coater. After that, similarly to the second embodiment, in the thermal curing step, the colored coating film 213 is heated, dried, and cured. Specifically, the colored coating film 213 is cured by heating at 100 ° C. for 1 minute using an electronic jet drier. In this step, the colored coating film 2
13 hardens almost completely.

Thereafter, in the same manner as in the third embodiment, an undercoating step, an intermediate coating step, an intermediate coating / undercoating semi-curing step, a polishing step, and an overcoating step are performed, and further, an electron beam irradiation step is performed. In the electron beam irradiation step, while the top coat 116 is cured,
The intermediate coating film 115 and the undercoating film 114 in the semi-cured state are also cured. Even when the coated wooden material 401 is manufactured by such a method, similarly to the above-described first to third embodiments, the coating film 411 is formed.
Of the coating 411, the adhesion of the coating 411 to the substrate, the adhesion between the layers of the coating 411, or the productivity of the coated wooden material 401 can be obtained. In addition, similarly to Embodiment 3, although the finish appearance is slightly inferior to Embodiments 1 and 2, the coated wood material 401 of this embodiment does not form a discarded coating film and eliminates the undercoat semi-curing step. Therefore, it can be manufactured at lower cost.

Next, Comparative Examples 1 and 2 according to the prior art
Each of the painted wooden materials will be described. (Comparative Embodiment 1) The painted wood material of Comparative Embodiment 1 is related to the prior art corresponding to Embodiment 1 described above. This painted wood material has the same size and shape as the painted wood material 101 of the first embodiment. The same applies to the wood material 102 used. The coating film formed on the surface of the wooden material 102 includes a discarded coating film directly formed on the wooden material 102, a colored coating film thereon, a primer coating film thereon, and an intermediate coating film thereon. In that it consists of a film and five layers of a top coat on it,
This is the same as the first embodiment. However, the composition of each coating film is different from that of the first embodiment.

The coated wooden material of Comparative Example 1 is manufactured as follows. Note that portions similar to those of the first embodiment and the like are omitted or simplified. See FIG. 5 for the outline of each step. First, the surface of the wooden material 102 is polished in advance with sandpaper. Next, in the disposing step, a disposing paint is applied to the wooden material 102. Nitco Co., Ltd. IST No. 100 with respect to 100 parts by weight, IST No. A mixture of 10 parts by weight of 5 parts is used. IST No. In No. 100, the base resin is composed of urethane acrylate, and 3 parts by weight of the photoinitiator is mixed with 100 parts by weight of the base resin. IST N
o. In No. 10, the base resin is made of polyisocyanate. Therefore, this disposable paint is used in Embodiments 1 and 2.
It contains more photoinitiator than that used in 2. After that, in a discarding semi-curing step, the coating film of the discarding paint is irradiated with ultraviolet rays to be semi-cured. At this time, the discolored coating film is irradiated with ultraviolet rays of 120 mJ / cm ² . The reason that a larger amount of ultraviolet light is irradiated than in the first and second embodiments is that the coating film is semi-cured in consideration of the adhesion to the colored coating film described below, while the coating film does not remain in the coating film immediately after completion. This is because it is desired to advance the hardening of the discarded coating film as much as possible in order not to leave hardening components as much as possible.

Next, in the coloring step, a coloring paint is applied on the semi-cured discarded coating film. An aqueous stain manufactured by Natco Corporation is used for the coloring paint. This is the same as the paint used in the second and fourth embodiments. Thereafter, in a heat curing step, the coating film of the coloring paint is heated to dry and cure the coloring coating film. In this step, as in Embodiments 2 and 4, the colored coating film is almost completely cured.

Next, in the undercoating step, an undercoat is applied on the cured colored coating film. The undercoat paint includes IST No. 300 to 100 parts by weight,
IST No. A mixture of 10 parts by weight of 5 parts is used. IST No. In No. 300, the base resin is composed of urethane acrylate, and 3 parts by weight of the photoinitiator is mixed with 100 parts by weight of the base resin. IST N
o. No. 10 is a resin whose base resin is composed of polyisocyanate as described above. Therefore, this undercoat paint also
It contains a larger amount of photoinitiator than that used in Embodiments 1-4. Then, in the undercoat semi-curing step, the coating film of the undercoat paint is irradiated with ultraviolet rays to be semi-cured. At this time, the discolored coating film is irradiated with ultraviolet rays of 120 mJ / cm ² . Irradiation with a larger amount of ultraviolet light than in Embodiments 1 and 2 is because the undercoating film is semi-cured in consideration of the adhesion to the intermediate coating film described below, but is not cured in the coating film immediately after completion. This is because it is desired to advance the curing of the undercoating film as much as possible in order not to leave the component as much as possible.

Next, in the intermediate coating step, an intermediate coating is applied on the semi-cured undercoat film. For the intermediate coating, IST No. Use 400. IST N
o. In No. 400, a base resin is composed of an ester acrylate, and 3 parts by weight of a photoinitiator is mixed with 100 parts by weight of the base resin. Therefore, this intermediate coating also contains a larger amount of photoinitiator than those used in the first and second embodiments. Thereafter, in the intermediate coating semi-curing step, the intermediate coating film is irradiated with ultraviolet rays to semi-cur the intermediate coating film.
At this time, the discolored coating film is irradiated with ultraviolet rays of 120 mJ / cm ² . The reason that a large amount of ultraviolet light is irradiated from the first to fourth embodiments is that the intermediate coating film is semi-cured in consideration of the adhesion to the top coating film described below, but is not cured in the coating film immediately after completion. This is because it is desired to advance the curing of the intermediate coating film as much as possible in order not to leave the component as much as possible.

Next, a polishing step is performed in the same manner as in the first embodiment. Next, in a top coat process, a top coat is applied on the semi-cured intermediate coat film. For the top coat, IST No. Use 500. IST No. 5
00, the base resin is made of ester acrylate,
3 parts by weight of the photoinitiator is mixed with 100 parts by weight of the base resin. Therefore, in this top coat, Embodiment 1
Unlike the topcoats used in Nos. 1 to 4 do not contain a photoinitiator, they contain a large amount of photoinitiator. After that, in the ultraviolet curing step, the coating film of the top coat is irradiated with ultraviolet light,
The top coat is cured, and the semi-cured intermediate coat, undercoat, and discarded coat under the top coat are also cured. At that time, the top coat is irradiated with ultraviolet rays of 240 mJ / cm ² . As described above, the painted wood material of Comparative Embodiment 1 is manufactured.

(Comparative Embodiment 2) On the other hand, the coated wooden material of Comparative Embodiment 2 is related to the prior art corresponding to Embodiment 3 described above. This painted wood material has the same size and shape as the painted wood material 301 of the third embodiment, and the wood material 102 used is also the same. The coating film formed on the surface of the wooden material 102 is a colored coating film directly formed on the wooden material 102, an undercoat film thereon, and an intermediate coating film thereon.
The third embodiment is the same as the third embodiment in that it further comprises four layers of a top coat. However, the composition of each coating film is different from that of the third embodiment.

The coated wooden material of Comparative Example 2 is manufactured as follows. Note that parts similar to those of the third embodiment and the like are omitted or simplified. See FIG. 5 for the outline of each step. First, the surface of the wooden material 102 is polished in advance. Next, in the coloring step, a colored paint is applied on the semi-cured discarded coating film. An aqueous stain manufactured by Natco Corporation is used for the coloring paint. This corresponds to the second and fourth embodiments.
And the same paint as that used in Comparative Example 1. Thereafter, in a heat curing step, the coating film of the coloring paint is heated to dry and completely cure the coloring coating film.

Next, in the undercoating step, an undercoat paint is applied on the cured colored coating film. As in Comparative Example 1, IST No. 300
With respect to 100 parts by weight of IST No. A mixture of 10 parts by weight of 5 parts is used. Thereafter, the process proceeds to the next intermediate coating process without performing the semi-curing process. In the intermediate coating process, an intermediate coating is applied on the undercoat film. As in Comparative Example 1, IST No. 40
Use 0. Thereafter, in the intermediate coating / undercoat semi-curing step, the coating film of the intermediate coating material is irradiated with ultraviolet rays to semi-harden the intermediate coating film and the underlying coating material thereunder. At this time, the intermediate coating film is irradiated with ultraviolet rays at 120 mJ / cm ² .

Next, a polishing step is performed in the same manner as in the first embodiment. Next, in an overcoating step, an overcoat is applied on the semi-cured intermediate coating film. As in Comparative Example 1, IST No. Use 500. Thereafter, in the ultraviolet curing step, the top coat is irradiated with ultraviolet light to cure the top coat and also to cure the semi-cured intermediate coat and the undercoat below. At that time, 240 mJ / cm ²
Irradiation of ultraviolet rays. As described above, the coated wooden material of Comparative Embodiment 2 is manufactured.

(Experimental Results) Next, in the first and third embodiments,
Various comparative experiments were conducted on the painted wood materials 101 and 301 according to the present invention and the painted wood materials according to the conventional techniques (Comparative Embodiments 1 and 2), and the usefulness of the present invention was examined. The result is shown in FIG.

In the comparative experiment shown in FIG.
The “adhesion after one week of painting”, “pencil hardness”, “scratching property”, “cracking property”, “contamination”, “chemical resistance”, “light resistance”, and “finished appearance” were investigated. "Initial adhesion" means that JIS-K540
0, according to the cross-cut tape method,
A cellophane tape peeling test was performed on a grid of 2 mm width (100 pieces = 10 × 10). Then, the area of the portion where the coating film remained without peeling was determined. In Comparative Example 1, the portion where the coating film was not peeled was 80, and in Comparative Example 2, it was 50, whereas in Embodiments 1 and 3, both were 100, that is, the coating film was not peeled at all. This indicates that the application of the present invention improves the adhesion of the coating film immediately after production.

The "adhesion one week after coating" was examined in the same manner as in the initial adhesion described above. As a result, in each of Comparative Examples 1 and 2 and Embodiments 1 and 3, 100, that is, the coating film was not peeled off at all. From this, it can be seen that the adhesion of the coating film after one week from the production is not different between the conventional coated wood material and the coated wood material according to the embodiment.

[0094] For the "pencil hardness", a test for scratching the coating film surface was conducted by a tester method based on JIS K5400. The hardness of the hardest pencil, which does not scratch the coating even when scratched with a pencil, was examined. As a result, it was "H" in Comparative Embodiment 1 and "HB" in Comparative Embodiment 2, whereas it was "3H" in Embodiments 1 and 3. From this, it is understood that the strength of the coating film is improved by applying the present invention.

In the case of "scratchability", a test was conducted in which a painted surface was rubbed with a 500 yen coin. When no abnormality was observed even when rubbed with a 500-yen coin, the result was evaluated as "O", slightly whitened as "△", and whitened as "X". As a result, in Comparative Examples 1 and 2, both were “×”,
In the first and third embodiments, both were “共 に”. This indicates that the application of the present invention improves the scratch property of the coating film.

In the "cracking property", two cycles were performed at 80 ° C. for 2 hours and at -20 ° C. for 2 hours based on the special plywood JAS standard. A sample with no abnormality was evaluated as “「 ”, a sample with slight cracking was evaluated as“ Δ ”, and a model with cracking was evaluated as“ x ”. As a result, "△" in Comparative Embodiment 1 and "X" in Comparative Embodiment 2, whereas "O" in both Embodiments 1 and 3. This indicates that the application of the present invention improves the cracking property of the coating film.

In the case of "contamination", an oil-based magic (red, black, blue ink) was applied based on the special plywood JAS standard, and a test was performed after wiping for 4 hours. A sample in which no abnormality was observed was evaluated as “○”, a model in which a slight color remained was evaluated as “△”, and a model in which the color remained was evaluated as “x”. As a result, Comparative Examples 1 and 2
In each of the first and third embodiments, the result was “○”. This indicates that the application of the present invention improves the physical properties of the coating film against stains.

In the "chemical resistance" test, a 1% aqueous solution of sodium carbonate and a 5% aqueous solution of acetic acid were added dropwise according to the JAS standard for special plywood, and a test was performed in which the sample was wiped off after standing for 6 hours. A sample with no abnormality was evaluated as “○”, a sample with slight change in gloss was evaluated as “Δ”, and a sample with whitening or change in gloss was evaluated as “x”. As a result, in Comparative Examples 1 and 2, both were “△”, while in Examples 1 and 3, both were “○”. This indicates that the application of the present invention improves the chemical resistance of the coating film.

In the “light resistance”, a test was conducted in which irradiation was performed with a fading mercury lamp for 24 hours based on the JAS standard for special plywood. A sample with no abnormality was evaluated as “○”, a sample with slight discoloration was evaluated as “Δ”, and a sample with discoloration was evaluated as “X”. As a result, in Comparative Examples 1 and 2, both were “△”, while in Examples 1 and 3, both were “○”. This indicates that the application of the present invention improves the light resistance of the coating film.

In the “finished appearance”, the finished appearance of the coated wood was evaluated by visual observation and touch. ○ indicates that no abnormality was observed visually and to the touch, △ indicates that there was no abnormality in the visual but rough feeling, and × indicates that there was an abnormality in the visual and feel. Was evaluated. As a result, "△" in Comparative Embodiment 1 and "X" in Comparative Embodiment 2, whereas "O" in both Embodiments 1 and 3. This shows that the application of the present invention improves the finished appearance.

As described above, the coated wooden materials 101 and 301 according to Embodiments 1 and 3 have an initial adhesion, a pencil hardness, and a lower hardness than the coated wooden materials of the prior art (Comparative Examples 1 and 2).
Scratch resistance, crack resistance, contamination, chemical resistance, light resistance,
It can also be seen that both the finished and finished appearances are excellent. Also, it can be seen that the adhesion after one week of coating is the same as the conventional one.

In the above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to each of the above-described embodiments 1 to 4, and may be appropriately modified without departing from the spirit of the present invention. It goes without saying that you can do it. For example, in each of Embodiments 1 to 4, after forming all the coating films, each coating film is cured by an electron beam. However, the coating film can be cured with an electron beam in the course of forming the coating film. However, when the coating film to be the inner layer is completely cured with an electron beam, the adhesion between the coating films is reduced when a coating film is subsequently formed thereon. Therefore, it is preferable that the curing by the electron beam is performed after forming the outermost coating film.

In the first and second embodiments, a five-layer coating film is formed, and in the third and fourth embodiments, a four-layer coating film is formed. It can be formed, or a small number of coating films can be formed.
In general, when the number of coating films is increased, the appearance of painted wooden materials tends to be more beautifully finished. On the other hand, if the number of coating films is reduced, the number of man-hours required for manufacturing is reduced, and the amount of paint used is also reduced, so that the coated wood can be made more inexpensive.

[Brief description of the drawings]

FIG. 1 is a partially enlarged cross-sectional view of a painted wooden material according to a first embodiment.

FIG. 2 is a partially enlarged sectional view of a painted wooden material according to a second embodiment.

FIG. 3 is a partially enlarged sectional view of a painted wooden material according to a third embodiment.

FIG. 4 is a partially enlarged cross-sectional view of a painted wooden material according to a fourth embodiment.

FIG. 5 is an explanatory view showing a difference in a manufacturing method between each embodiment and each comparative embodiment.

FIG. 6 is an explanatory diagram showing a difference in physical properties between each embodiment and each comparative embodiment.

[Explanation of symbols]

 101, 201, 301, 401 Painted wood material 102 Wood material 111, 211, 311, 411 Paint film 112 Discard paint film 113, 213 Color paint film 114 Undercoat paint film 115 Intermediate paint film 116 Top paint paint film

────────────────────────────────────────────────── ─── front page continued (51) Int.Cl. ⁷ identifications FI theme coat Bu (reference) B05D 7/24 301 B05D 7/24 301T B27K 5/02 B27K 5/02 a 5/06 5/06 B F Term (Reference) 2B230 AA08 AA09 AA10 AA11 AA16 AA22 BA01 BA18 CC14 DA02 EA14 EA20 EB03 EB07 EB08 2B250 BA03 BA05 BA06 CA11 DA03 FA33 GA03 HA01 4D075 AE03 AE06 AE13 BB26Z BB27Y BB21 BB47 DC21

Claims (9)

[Claims] 1. A method for producing a coated wooden material coated with a wooden material, comprising: a semi-cured first coating film; and an uncured second coating film applied on the first coating film. A method for producing a coated wooden material comprising an electron beam curing step of irradiating a material with an electron beam to cure an uncured second coating film and also cure a semi-cured first coating film thereunder. 2. The method for producing a coated wooden material according to claim 1, wherein the second coating film is a coating film forming the outermost surface of the coated wooden material. 3. The method for producing a coated wooden material according to claim 1, wherein the semi-cured first coating film is semi-cured by irradiation with ultraviolet light. . 4. The method for producing a coated wooden material according to claim 1, wherein the semi-cured first coating film comprises a plurality of semi-cured coating films overlapping each other. A method for manufacturing wood. 5. A method for producing a painted wooden material coated with a wooden material, comprising: a disposing step of applying a disposable paint to the wooden material; A semi-curing step of semi-curing the discarded coating film; a coloring step of applying a coloring paint on the semi-cured discarded coating film; A coloring semi-curing step of semi-curing the coating film, an undercoating step of applying an undercoat paint on the semi-cured colored coating film, and irradiating the undercoat paint film with ultraviolet light, thereby semi-curing the undercoat paint film. An undercoat semi-curing step of curing, an intermediate coating step of applying an intermediate coating on the semi-cured undercoat film, and irradiating ultraviolet rays to the intermediate coating film to partially cure the intermediate coating film. Curing step, a topcoating step of applying a topcoating paint on the semi-cured intermediate coating film, The top coat is irradiated with an electron beam to cure the top coat, and also to cure the semi-cured intermediate coat, undercoat, colored coat and discard coat under the coat. A method for producing a coated wooden material, comprising a wire curing step. 6. A method for producing a coated wood material coated with a wood material, comprising: a discarding step of applying a discarded paint to the woody material; A semi-curing step of semi-curing the discarded coating film, a coloring step of applying a coloring paint on the semi-cured discarded coating film, and heating the coating film of the coloring paint to form the colored coating film A thermosetting step of drying and curing the undercoating step of applying an undercoat paint on the cured colored coating film, and irradiating ultraviolet rays to the undercoat paint film to partially cure the undercoat paint film. A semi-curing step, an intermediate coating step of applying an intermediate coating on the semi-cured undercoat, and an intermediate coating semi-curing step of irradiating the coating of the intermediate coating with ultraviolet light to semi-curing the intermediate coating. A topcoating step of applying a topcoat on the semi-cured intermediate coating film, An electron beam curing step of irradiating the coating film of the coating material with an electron beam to cure the overcoating film and also curing the semi-cured intermediate coating film, the undercoating film and the discarded coating film under the coating film. A method of manufacturing painted wood materials. 7. A method for producing a coated wood material coated with a wood material, comprising: a coloring step of applying a coloring paint to the wood material; A semi-curing step of semi-curing, an undercoating step of applying an undercoat on the semi-cured colored coating film, an intermediate coating step of applying an intermediate coating on the undercoat paint film, A middle coat / undercoat semi-curing step of irradiating the coating film with ultraviolet light to partially cure the intermediate coat film and the undercoat film thereunder, and a top coat step of applying a top coat on the semi-cured intermediate coat film An electron beam curing step of irradiating an electron beam to the coating film of the top coating material to cure the top coating film, and also curing the semi-cured intermediate coating film, the undercoating film, and the colored coating film thereunder. And a method for producing a coated wooden material. 8. A method for producing a coated wood material coated with a wood material, comprising: a coloring step of applying a coloring paint to the wood material; and heating the coating film of the coloring paint to dry the coloring coating film. A thermosetting step of curing and curing, a undercoating step of applying an undercoat on the cured colored coating, an intermediate coating step of applying an intermediate coating on the undercoat coating, and a coating of the intermediate coating. Irradiating ultraviolet rays, an intermediate coating / undercoat semi-curing step of semi-curing the intermediate coating film and the undercoat film thereunder, An electron beam curing step of irradiating the coating film of the top coat with an electron beam to cure the top coat and also curing the semi-cured intermediate coat and the undercoat below. Manufacturing method. 9. A coated wooden material coated with a wooden material, wherein the coating film is cured by irradiation with an electron beam. Immediately after the coating film is cured, the coating film is subjected to an adhesion test described in JIS-K5400. According to the crosscut tape method, 2
100 square mm squares (= 10 × 10), after peeling off the adhesive tape and peeling off, the coated wood material with initial adhesion is 5% or less of the total area of the coating. .