JP4347324B2 - Wood-based decorative plywood and its manufacturing method - Google Patents

Description

  The present invention relates to a wood-based decorative plywood and a method for producing the same. More specifically, the present invention relates to a wood-based decorative plywood used for flooring and a method for producing the same.

  A decorative plywood having a surface specially processed using a plywood as a base material is often used as a flooring material. In recent years, a mirror finish is used to improve the quality.

Conventionally, when mirror-finishing with a processed material based on plywood, the surface of the plywood is swelled with sandpaper with a coarse particle size, and then carefully polished with a sandpaper with a fine particle size and smoothed. It is necessary to perform the polishing operation to be performed 3 to 5 times.
And also in the painting, the process of applying the sanding sealer, polishing the coating film and removing the roughness is repeated several times, and finally the mirror finish is possible. As described above, since painting and coating surface polishing are repeated many times, the work is very laborious and the surface of the cured coating film must also be ground, resulting in the problem of loss of raw materials.

  In addition, as a method of reducing the painting and polishing, there is a method in which a buffer (buffer material) is pasted on the surface of the base material after being polished to a certain extent. Become. Therefore, the mirror finish has a very high manufacturing cost.

  On the other hand, as a prior art described in Patent Document 1, there is a method in which a wooden board and decorative paper are bonded via a non-solvent radical polymerizable adhesive (for example, an unsaturated polyester resin adhesive containing an inorganic filler). . In this case, in particular, either the adhesive or the polymerization initiator of the adhesive is applied to the decorative paper side, and the other is applied to the wooden board side. I try to manufacture.

This conventional technology has a surface hardness that passes F type of Japan Agricultural Standard (JAS) of special plywood, even though decorative paper is pasted, and is suitable for counters, table tops, top plates of kotatsu, etc. A simple wood-based decorative board can be manufactured at low cost.
However, since this conventional technique does not perform mirror finishing at the same time, there is a drawback that it takes additional man-hours to perform mirror finishing.

JP-A-6-320675

  In view of the above circumstances, the present invention provides a decorative plywood surface-decorated with decorative paper, and can be mirror-finished and manufactured at low cost even if the decorative paper is thin and soft and easily affected by the base. An object is to provide a wood-based decorative plywood and its manufacturing method.

Wooden decorative plywood of the first invention is formed on the surface of the wood substrate, a melamine resin layer is mirror finished, is adhered to the surface of the melamine resin layer, Ri Do and a mirror-finished decorative paper, the The melamine resin layer is characterized by comprising an undercoat low molecular melamine resin layer and an overcoat polymer melamine resin layer .
The method for producing a wood-based decorative plywood according to the second aspect of the present invention is to apply a melamine resin to the surface of a wooden substrate to form a melamine resin layer, and when the melamine resin layer is uncured, heat is applied to the surface of the melamine resin layer. It comprises a step of applying a curable adhesive to form an adhesive layer, affixing a decorative paper on the upper surface of the adhesive layer, and heating and pressing using a press plate mirror-finished from the upper surface of the decorative paper , The application of the melamine resin is characterized in that a low molecular melamine resin is used as an undercoat and a high molecular melamine resin is used as an overcoat .
The method for producing a wood-based decorative plywood according to a third aspect of the present invention is characterized in that, in the second aspect , the melamine resin is overcoated by a second coating process, and the second coating is performed using a melamine resin containing an inorganic feeler. .

According to the first invention, the low molecular weight melamine resin used for the undercoating penetrates into the interior of the wooden base material and fills the internal conduits, etc., so that the hardness of the manufactured equipment can be kept high. The polymer melamine resin used for overcoating has a good film-forming property, so a hard coating can be formed on the surface of the substrate , and the melamine resin layer itself is mirror-finished so that it is adhered to the surface. The decorative paper also has a mirror finish. Further, since the cured melamine resin layer has a very high hardness, it becomes a mirror-finished decorative plywood with sufficiently high smoothness and hardness.
According to the second invention, the low molecular weight melamine resin used for the undercoat penetrates into the interior of the wooden base material and fills the internal conduits, etc., so that the hardness of the manufactured equipment can be kept high. The polymer melamine resin used for overcoating has a good film-forming property, so that a hard coating film can be formed on the surface of the substrate, and the surface of the decorative paper can be kept flat even if the decorative paper is thin and soft. Further, when the decorative paper is heated and pressurized via an adhesive when the melamine resin layer is uncured, the decorative paper is adhered while the melamine resin layer is cured, so that the manufacturing time can be shortened. Furthermore, since the surface of the press plate is mirror-finished, the surface of the melamine resin layer can be cured while being finished to a mirror-level smoothness when pressed. Further, the decorative paper to be adhered to the surface can be finished to a mirror surface by simultaneously applying pressure, and no further mirror finishing work is required, so the number of work steps can be reduced .
According to the third aspect of the invention, since the uppermost coating film formed by the second overcoating contains the temperament filler, the surface hardness of the coating film is improved.

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a cross-sectional view of a wood-based decorative plywood A according to an embodiment of the present invention.
In the figure, A is a decorative plywood, which is composed of a wood-based substrate 1, a melamine resin layer 2, an adhesive layer 3, decorative paper 4, and a finished coating film 5 laminated on the surface thereof.

As the base material 1, any material such as a single board, a plywood board, a particle board, and an OSB board can be used as long as they are woody.
These woody substrates 1 have fine irregularities due to streaks and conduits, and also have undulations that are gently curved. Moreover, since cavities, such as a conduit | pipe and a damage | wound, exist also in the inside of the base material 1, in order to make the surface smooth and to raise hardness, the said melamine resin layer 2 is used.

The decorative paper 2 is made of pulp or synthetic resin. Examples of pulp-based materials include kraft paper, Japanese paper, and mixed paper, and reinforced paper impregnated with synthetic resin. Examples of synthetic resin materials include olefin sheets and polyethylene sheets, and thin films or slightly thick sheets are used. Incidentally, the 23g / m ² ~30g / m ² paper used in laminated veneer widely used as weighed. Since these decorative papers are thin and soft, they are easily affected by fine irregularities and undulations of the base material 1 as a base, but according to the production method of the present invention, they are finished to a mirror surface with extremely high smoothness.

The melamine resin used in the present invention is a thermosetting type and has a property of being cured by heating. Moreover, when it hardens | cures, it becomes a hard film | membrane and can form the coating film excellent in water resistance and a weather resistance. Furthermore, the price is low.
Moreover, in this invention, a low molecular type and a high molecular type are used properly for a melamine resin according to a use. The low molecular weight type is characterized by good penetration into wood. Therefore, it is used for impregnating the base material 1 and filling between wood fibers or a conduit. The polymer type is a blend of 5% to 10% of fine powder (10 μ to 100 μ) of an inorganic material, and has a feature that the film forming property for maintaining the shape of the coating film is good. Therefore, this polymer melamine resin is applied to the surface of the substrate 1 and used to form a surface coating film.

  If the adhesive 3 uses a thermosetting type, there exists an advantage that the said melamine resin can be hardened | cured and adhesion | attachment of a decorative sheet can be simultaneously carried out with a hot press with a hot press.

Next, the production method of the present invention will be described.
FIG. 2 is an explanatory view showing the first half of the method for producing a wood-based decorative plywood according to the present invention, and FIG. 3 is an explanatory view showing the second half.
Hereinafter, a description will be given with reference to FIGS. The following symbols (1) to (9) correspond to the symbols (1) to (9) in FIGS.
(1) A substrate 1 is prepared. As described above, the base material 1 at this stage has streaks, scratches, dents, undulations, and the like peculiar to the woody system.

(2) A melamine resin is applied to the surface of the substrate 1 to form the melamine resin layer 2. First, a low molecular melamine resin 2a is applied. Since this low molecular type melamine resin is a low molecule, it penetrates into the base material 1 and fills in the scratches and conduits in the base material 1.
Next, the polymer melamine resin 2 b is applied to the surface of the substrate 1. The melamine resin containing an inorganic feeler is used in the second overcoating in the second coating step. Since this polymer type melamine resin is a polymer, it has good film-forming properties, and a coating film having a certain thickness is formed on the surface of the substrate 1.
In addition, as an application means, an arbitrary one such as a roll coater is used.

(3) The applied melamine resin layer 2 is dried. For drying, a hot air dryer or the like is used, and hot air spraying or the like is used. In this step, the melamine resin layer 2 begins to harden, but proceeds to the next step in a semi-cured state.
The significance of this process is that it is difficult to apply adhesive for decorative paper if the melamine resin is a water-soluble type and a large amount of moisture remains. This is to prevent the adhesiveness of 1 from being inhibited. For this reason, the water | moisture content of the melamine resin layer 2 is diverged more than half by hot air drying around 60 ° C.

(4) When the melamine resin layer 2 is in an uncured state, a thermosetting adhesive such as a thermosetting type adhesive is applied to form the adhesive layer 3.
(5) The applied adhesive layer 3 is also dried with hot air. The significance of this step is to improve workability by temporary bonding, to reduce the amount of steam in the hot press, and to facilitate thermal bonding.

(6) A decorative paper 4 is pasted on the upper surface of the adhesive layer 3.
(7) Heat and press from the upper surface of the decorative paper 4 using a flat hot plate type hot press.
Thereby, the decorative paper 4 is fixed to the melamine resin layer 2 through the adhesive layer 3 at a pressure of 10 to 15 MPa at 150 ° C. or higher.

The press plate 10 of the hot press used in the step (7) is polished with a 600 grain size abrasive and mirror-finished with a mirror puff.
(8) Therefore, the surface of the melamine resin layer 2 is hardened and finished to a smooth mirror surface. Therefore, the decorative paper 4 bonded to the front surface is also in contact with the smooth resin layer 2 on the back surface side, and the front surface side is pushed by the press plate 10 and is also smoothed, so that it is finished to a mirror surface.

(9) Finish coating is performed on the surface of the mirror-finished melamine resin layer 2 to form a finished coating film 5.

Example 1
The thickness adjusted tropical wood substrate 1 on the surface of 11.9 mm, a low-molecular melamine resin (resin content 50wt%) 15g / m ² was coated with a roll coater, after about 10 seconds, the polymer of the inorganic feeler formulation Type melamine resin was applied with a 102 g / m ² flow coater.
An example of blending the inorganic feeler can include 80 parts by weight of calcium carbonate and 20 parts by weight of titanium, but is not limited thereto.
Subsequently, it was dried for about 13 to 15 seconds in a hot air drying oven at 60 ° C. to dissipate 70% to 80% of water.
With the surface semi-dried, apply an acrylic resin adhesive for application of decorative paper at about 82 g / m ^2, apply hot air at about 80 ° C. for about 10 seconds to 15 seconds, and semi-dry the decorative paper 4 Was temporarily pasted with a laminator. Subsequently, the melamine resin layer 2 on the surface of the substrate 1 is cured and the decorative paper 4 is pasted and bonded simultaneously through a smooth specular hot plate at a temperature of 140 ° C. to 150 ° C. and a pressure of 15 kg / cm ² for 80 seconds. went.

As a finishing surface coating on the base material 1 on which the decorative paper 4 has been pasted, a non-solvent UV paint was applied undercoating 2 g / scale ² , intermediate coating 2 g / scale ² , top coating 3 g / scale ² and UV cured.
In this example, a desired mirror-finished product could be obtained by applying 7 g / scale ² .
Applying decorative paper 4 to the plywood using the conventional method to obtain the same mirror finish, undercoat 3g / scale ² → # 320 paper polishing → intermediate coating (1) 2g / scale ² → # 320 paper polishing → intermediate coating (2) 2 g / scale ² → # 320 paper polishing → intermediate coating (3) 2 g / scale ² → # 480 paper polishing → intermediate coating (4) 2 g / scale ² → # 520 paper polishing → top coat 3 g / scale ² Thus, a total coating amount of 15 g / scale ² was necessary. In comparison, in Example 1, 54% of paint was saved.
In addition, the surface hardness is a test method that measures the amount of dent when a 500g steel ball is dropped from a height of 1m, and the conventional finish is 0.53mm in average dent depth, which can be reduced to 0.42mm in the wood board according to the present invention. .

It is sectional drawing of the wood type decorative plywood which concerns on one Embodiment of this invention. It is explanatory drawing which shows the first half of the manufacturing method of the wood type decorative plywood which concerns on this invention. It is explanatory drawing which shows the second half of the manufacturing method of the wood type decorative plywood which concerns on this invention.

DESCRIPTION OF SYMBOLS 1 Base material 2 Melamine resin 3 Adhesive layer 4 Decorative paper 5 Finishing film 10 Press board

Claims (3)

A melamine resin layer formed on the surface of a wooden substrate and mirror-finished;
Is bonded to the surface of the melamine resin layer, Ri Do and a mirror-finished decorative paper,
The woody decorative plywood , wherein the melamine resin layer comprises an undercoat low molecular melamine resin layer and an overcoat polymer melamine resin layer . A melamine resin layer is formed by applying a melamine resin to the surface of the wooden substrate,
When the melamine resin layer is in an uncured state, a thermosetting adhesive is applied to the surface of the melamine resin layer to form an adhesive layer,
Affixing a decorative paper on the upper surface of the adhesive layer,
It consists of a step of heating and pressurizing using a press plate mirror-finished from the top surface of the decorative paper ,
The method for producing a wood-based decorative plywood, wherein the melamine resin is applied using a low-molecular melamine resin as an undercoat and a high-molecular melamine resin as an overcoat . 3. The method for producing a wood-based decorative plywood according to claim 2, wherein the top coating of the melamine resin is performed by a two-time coating process, and a melamine resin containing an inorganic feeler is used in the second top coating.

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