JPH0788802A - Manufacture of wooden decorative material - Google Patents

Abstract

PURPOSE:To manufacture a fine wooden decorative material, in which the defect at scarf joint does not emerge outside, by a method wherein a wooden decorative veneer is laminatingly integrated with a wooden base material, which is formed in a continuous form by scarf jointing. CONSTITUTION:By applying a heat-softening synthetic resin liquid, which is elastic after curing, a coating layer 7, in which scarf joint 2 is filled with and imbedded in the resin liquid, is provided. After the curing of the resin liquid coating layer 7, the resin coated surface of the wooden base material 1 is ground by sanding or the like so as to expose the ground surface of the wooden base material. At this time, the surface coating layer 7 of the wooden base material is ground so as to leave the cured resin in the recessed part, in which the scarf joint 2 is filled with and imbedded in, its neighboring part and defective recessed parts 8 in order to flat the surface of the wooden base material. Next, the wooden decorative veneer 10 is laminated through a water-based adhesive 9 onto the wooden base material 1 and made into an integral body. Thus, the solvent of the water-based adhesive is fully permeated into the exposed surface layer of the wooden base material so as to turn the exposed surface layer into swollen state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, when a laminated wood decorative veneer is integrally laminated on a wood base material formed by scarf bonding to make it long, the scarf bonding portion is treated so as not to be conspicuous on the surface side. The present invention relates to a method of manufacturing a wood-based decorative material.

[0002]

2. Description of the Related Art Conventionally, as a base material for a long wooden decorative material such as a wooden flooring material, a veneer with few defects such as seams, cracks, pipes and wormholes has been used. In recent years, there has been a shortage of good veneers with few such defects, so short rectangular wood veneer pieces are joined in the vertical direction to form a long base material, and then the surface is coated with makeup. Lamination and integration of veneers are performed.

[0003]

However, when a base material is formed by using scarf joining as a vertical connecting means for short wood veneer pieces, a surface having a thickness of 1 is used as a decorative material.
If a decorative wood veneer such as a WPC board with transparency added by a resin injection sheet or resin is attached, the scarf joint of the base material is conspicuous from the surface side of the decorative wood veneer and the appearance is significantly impaired. become. For this reason, it is common practice to put a putty layer or an adhesive layer with high concealing property on the surface of the wooden base material before attaching the wood decorative veneer. If only done, there is a problem in that a convex portion or a striped shadow is generated around the scarf joint portion and the shadow is exposed to the outside, which lowers the commercial value.

The reason why such a convex portion or a striped shadow is generated is that the wood portion around the joint is compressed during the scarf joint and a compressive stress remains as compared with other portions, and the adhesive bond in this state. When the wood decorative veneer is integrated under heat and pressure with the adhesive, the moisture contained in the adhesive permeates through the mouth of the scarf joint, and the residual stress at the scarf joint is relieved by the high temperature heat during hot pressing. As a result, the peripheral part of the scarf joint is restored in the thickness direction more than other woody parts, and heat pressure is applied against this restoration, so excess pressure acts on the peripheral part of the scarf joint and the pressure is stronger than other parts. It is thought that this is because the scarf joint peripheral portion becomes darker in color and uneven coating of the paint occurs in other portions. The present invention has been made in view of the above problems, and an object thereof is to provide a method capable of producing a beautiful wooden decorative material in which a defect of a scarf joint does not appear to the outside. It is in.

[0005]

In order to achieve the above object, a method for producing a wood-based decorative material of the present invention is such that at least the surface of a wood-based base material having a scarf joint on the surface side is elastic after curing. By applying a thermosoftening synthetic resin liquid having a, the scarf joint portion is filled with a synthetic resin liquid, a resin coating layer embedded is provided, after curing the coating layer, leaving at least the scarf joint portion. The surface of the wood base material is exposed by grinding the coating layer, and the water-based adhesive is applied to the exposed surface, and then a wood decorative veneer is placed and laminated on the surface of the wood base material by heat pressure, and integrated. It is characterized by that.

[0006]

[Function] After applying a thermosoftening synthetic resin liquid having elasticity after curing to the surface of a wood base material having a scarf joint, the resin coating layer is ground leaving the scarf joint,
When the water-based adhesive is applied to the exposed wooden substrate surface, the solvent of the water-based adhesive permeates into the substrate from the surface layer because the wooden substrate is hydrophilic, and swells the permeated portion,
Since the hardened elastic resin is layered around the scarf joint, permeation of the solvent of the water-based adhesive from the mouth is prevented.

Next, when the wood decorative veneer is placed on the wood base material and then hot pressed, the surface part of the wood base material that is swollen by the permeation of the water-based adhesive from the surface layer is softened and pressed. On the other hand, since the scarf joint part filled with elastic resin does not swell from the wood mouth, even if it is restored due to the relaxation of residual stress to some extent, it will be buffered by the elasticity of the resin and the wood base material will be pressed uniformly over the entire surface. The wood decorative veneer is laminated and integrated without swelling or darkening only the scarf joint.

[0008]

EXAMPLE Next, an example of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the base material 1 of the wood decorative material has a short rectangular shape with a thickness of 1 to 20 mm. Veneer, plywood,
A plurality of wood base material pieces such as MDF and particle board are longitudinally scarf-joined to form a long length, and a long strip plate material having the scarf joint portion 2 is a single body or a laminated body in which a plurality of layers are laminated, or , Which is integrally laminated on a wooden board without joints is used. A synthetic resin adhesive such as urea, melamine, phenol, resorcinol, vinyl urethane, etc. is used as the scarf bonding adhesive 3, and the scarf bonding part 2 and its surrounding base material part are partially pressed 4 after being applied to the bonding end face. It is pressed and joined and bonded. At this time, since the scarf joint portion 2 and its peripheral portion are compressed by compression, the compressive stress remaining portion 5 is generated.

After the scarf is joined, the surface of the joined portion may be ground by sanding or the like, if necessary, so that a step or a bulge portion generated when the diagonally cut end faces of the wood base material piece are wrapped, and a surplus portion. Remove the adhesive from
The surface is a flat surface 6 on which a wood veneer to be described later can be laminated.

Then, as shown in FIG. 3, a thermosoftening synthetic resin liquid having elasticity after curing is applied to the surface of the wooden base material 1, and a coating layer 7 filled and embedded in the scarf joint portion 2 is formed. Set up. As such a thermosoftening synthetic resin liquid having elasticity after curing, there are vinyl acetate, ethylene vinyl acetate, acrylic resin, acrylic urethane resin, vinyl urethane resin, and these synthetic resin liquids contain heat such as urea and urea melamine. A curable resin may be added. Further, if necessary, a freon compound such as trichloromonofluoromethane or a substance that generates carbon dioxide gas such as sodium bicarbonate or calcium carbonate is added to the synthetic resin liquid to give it properties as a foam to improve elasticity and heat resistance. The curability may be accelerated, and in addition, a filler such as clay or a curing accelerator such as a catalyst may be added.

The above-mentioned thermosoftening synthetic resin is used as a resin liquid whose solid content is adjusted to 20 to 60% by a solvent, and is applied to the surface of a wooden base material with a knife coater, roll coater, flow coater, brush or the like. It is applied at a rate of 120 g / cm ² = 120 g / cm ² and then dried at 70 to 200 ° C. for several tens to several minutes to be cured. The synthetic resin liquid may be applied only to the scarf joint portion 2 and its peripheral portion, but if it is applied to the entire surface of the wooden base material 1, cracks, conduits, and wormholes existing on the surface of the wooden base material 1 may be applied. It is preferable that the defective concave portion 8 such as a press mark is also repaired.

After the resin liquid coating layer 7 is cured, as shown in FIG. 4, the resin coated surface of the wood base material 1 is ground by sanding or the like to expose the surface of the cloth base material of the wood base material. At this time, the surface coating layer 7 of the wood-based material is ground to make the surface flat so that the cured resin of the scarf joint portion 2 which is filled and embedded in the concave portion and its peripheral portion and the defective concave portion 8 remains. To do. Next, as shown in FIG. 5, a wooden decorative veneer 10 is laminated and integrated on the wooden base material 1 with an aqueous adhesive 9 interposed therebetween.

The water-based adhesive 9 is a urea-, urea-melamine co-condensate, formaldehyde-based adhesive such as phenol resin, water-based vinyl urethane, or acrylamide-based adhesive. It is desirable to add a pigment in order to improve the above-mentioned properties and to make the wood base material 1 have a similar color. This water-based adhesive 9 is applied to the surface of the wooden base material 1 at a rate of 30 to ²⁰⁰ g / m ² = after grinding the surface coating layer 7 of the wooden base material 1 by sanding or the like, for a few minutes to a few hours, It is left at room temperature to 80 ° C. to allow the water-based adhesive 9 to penetrate into the exposed surface layer of the wood base material 1.

As the wood decorative veneer 10, a WPC board, which is a natural wood veneer having a thickness of 1 mm or less, or a natural wood veneer, is filled with unsaturated polyester or an acrylic resin solution, and before or after the resin solution is cured. To use. Further, even a surface-coated single plate not subjected to WPC treatment is effective as long as it has a thickness of 1 mm or less.

After the wood decorative veneer 10 is laminated on the wood base material 1 with the water-based adhesive 9 interposed therebetween, when the wood-made decorative veneer 10 is hot pressed at 80 to 200 ° C. for several seconds to several minutes, the solvent of the water based adhesive 9 permeates from the surface layer. The swelling of the wood base material 1 causes the surface layer part to be softened by heat and to be pressed, while the scarf joint part 2 and its peripheral part filled with the elastic resin do not swell from the wood mouth, so some residual stress Even if it is restored by relaxation, it is buffered by the resilience of the resin, the wood base material 1 is uniformly pressed over the entire surface, and only the scarf joint portion is not swollen or darkened
It is possible to obtain a beautiful wooden decorative material in which 10 layers are laminated and integrated so that a stripe-shaped light and shade does not appear around the scarf joint and uneven color due to uneven absorption of paint does not occur.

Next, examples of the present invention and comparative examples will be shown. Example 1 100 parts of vinyl urethane resin having a solid content of 50% and calcium carbonate were applied to the surface of a wood base material obtained by scarf-bonding two wood veneers having a thickness of 1.5 mm and affixing it on plywood. 30 parts, 0.5 parts each of carbon black and red iron oxide are added to the heat-softening resin solution using a knife coater at a rate of 50 g / m ² = and dried in an oven at a temperature of 100 ° C for 2 minutes. Then, it was taken out, and the resin coating layer was ground with a sander so that the dry-cured resin remained in a filled state in the scarf joint portion and its peripheral portion to expose the plywood surface. Then, a urea melamine resin adhesive is applied to the surface of the wooden base material.
100 g / m ² = applied at a rate of 1 m through the adhesive
A WPC veneer prepared by injecting unsaturated polyester resin into a m-sized cypress veneer is placed and cured in an oven at 80 ° C for 1 minute, and then heat-pressed at 150 ° C for 5 minutes with a press board to make a wooden decorative board. Got

Example 2 In place of the WPC veneer used in Example 1, a cypress veneer having a thickness of 0.3 mm was used. A wooden decorative board was obtained by stacking and integrating.

Comparative Example 1 The surface of the wood base material was corrected to a flat surface by sanding the scarf joint without using the thermosoftening resin of Example 1, and then the WPC unit was bonded with the same adhesive as in Example 1. A wooden decorative board was obtained by laminating and integrating the boards by the same operation.

Comparative Example 2 In place of the heat-softenable resin of the example, a commercially available epoxy resin putty was rubbed into the scarf joint and filled, and sanded the next day, and then the same operation as in Example 1 was performed. A wood decorative board was obtained by laminating and integrating WPC veneers on the surface of the base material.

The wooden decorative boards obtained in Examples 1 and 2 above,
Comparing with the wood decorative boards obtained in Comparative Examples 1 and 2, in the wood decorative boards of Examples 1 and 2, the scarf joint by the thermosoftening resin and the repair portion around it were completely different from the WPC veneer surface. Although not conspicuous, swelling occurred at the scarf joint portion in the wood-based decorative board of Comparative Example 1, and in the wood-based decorative board of Comparative Example 2, the portion repaired by the putty was a darkened color of the wood decorative veneer. It was visible from the surface and impaired the appearance.

[0021]

As described above, according to the method for producing a wood-based decorative material of the present invention, a thermosoftening synthetic resin liquid having elasticity after curing is applied to the surface of a wood-based material provided with a scarf joint. By coating, a resin coating layer is provided in which the above-mentioned scarf joint is filled and embedded with a synthetic resin liquid, and after the coating layer is hardened, the scarf joint is left and the coating layer is ground to obtain a wood base material. The surface of the exposed wooden base material is exposed, and after applying the water-based adhesive to the exposed surface, the wooden decorative veneer is placed and laminated on the surface of the wooden base material by heat and pressure to be integrated. The solvent of the water-based adhesive can be sufficiently permeated into the surface layer of (1) to bring it into a swollen state, while the cured elastic resin can prevent the permeation of the solvent of the water-based adhesive to the peripheral portion of the scarf joint.

Therefore, when the wood decorative veneer is placed on the wood base material and then hot pressed, the surface part of the wood base material that is swollen due to the permeation of the water-based adhesive from the surface part is softened and pressed. On the other hand, since the scarf joint part filled with elastic resin does not swell from the wood mouth, it can be buffered by the resilience of the resin even if it is restored by the relaxation of some residual stress, so that the wooden base material It is possible to obtain a wooden veneer with a beautiful appearance that can be uniformly pressed over the entire surface and does not swell or darken only the scarf joint portion.

[Brief description of drawings]

FIG. 1 is a simplified vertical sectional view showing a state where scarf joining is performed,

FIG. 2 is a schematic vertical sectional view of a scarf-bonded base material,

FIG. 3 is a simplified cross-sectional view of a base material coated with a heat-softening synthetic resin liquid,

FIG. 4 is a simplified cross-sectional view after sanding,

FIG. 5 is a simplified cross-sectional view of a wooden decorative material.

[Explanation of symbols]

 1 Wood base material 2 Scarf joint 7 Synthetic resin coating layer 9 Water-based adhesive

Claims (1)

[Claims] 1. A synthetic resin liquid is applied to the scarf joint to fill and embed it by applying a thermosoftening synthetic resin liquid having elasticity after curing to the surface of a wood base material provided with a scarf joint. An applied resin coating layer is provided, and after the coating layer is cured, the surface of the wood-based substrate is exposed by grinding the coating layer leaving at least the scarf joint, and the water-based adhesive is applied to the exposed surface. After that, a wood decorative veneer is placed, and laminated on the surface of the wood base material by heat and pressure so as to be integrated, and a method for manufacturing a wood decorative material.