JPS6254673B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing decorative plywood, and in detail,
To provide a method for smoothly attaching thin decorative paper of about 15-35 g/m ² to a plywood surface.

Conventional decorative paper laminated plywood is made by applying 50 to 100 g of vinyl acetate resin emulsion type adhesive to the plywood surface.
After applying about ² m2, blow hot air at about 90 to 110 degrees Celsius from the top surface to disperse the moisture in the adhesive to the point where it is not sticky to the touch (dry to the touch). 15~ with printed patterns etc.
It was manufactured by continuously layering thin decorative papers of about 35 g/m ² and pressing them together using one or several roll presses or flat plate presses.

However, in the case of decorative plywood manufactured by the conventional method, as shown in Fig.
This caused the eyes to become thinner, making it difficult to achieve a smooth makeup surface.

The reason for this is that the adhesive 2 is a hydrophilic emulsion type, so when the adhesive 2 is dry to the touch, the moisture in the adhesive 2 swells the decorative paper 3 and forms a film with the adhesive forming a sagging layer. It is thought that this is to draw them inwards.

Therefore, in order to prevent eye thinning, it is best to scatter the water in the adhesive applied to the plywood surface as much as possible to improve drying, but if the drying time of the adhesive is prolonged using the conventional method, the adhesive will be removed from the surface layer. Film formation progresses too much and the adhesive strength with the decorative paper is extremely reduced. For this reason, those skilled in the art have been forced to use an attachment method that focuses on the adhesive strength with the decorative paper without drying the adhesive to an extreme degree, sacrificing smoothness to some extent.

The present invention has been made to solve the above problems, and its gist is that the emulsion type thermoplastic synthetic resin adhesive applied to the surface of the plywood is rapidly heated at high temperature to sufficiently disperse moisture. At the very least, the purpose is to quickly form a film, bring the film into an active softening state, and then apply the decorative paper.

That is, after applying a conventional hydrophilic thermoplastic synthetic resin emulsion type adhesive alone or a mixture of a part of a thermosetting synthetic resin adhesive to the plywood surface,
By heating at a high temperature of 130℃ or higher, the moisture in the adhesive is rapidly and sufficiently dispersed to rapidly form a film, and at the same time, the thermoplastic synthetic resin in the emulsion type adhesive is activated to soften the film. This is a method for producing decorative thin paper laminated plywood, which is characterized in that thin decorative paper is layered on the top surface and pressed using one or several heating rolls or a flat press at a temperature of 120° C. or higher.

To explain the present invention in more detail with reference to the drawings, Fig. 2 shows a decorative plywood obtained by the present invention. First, the surface of the plywood 1 is coated with a commonly used hydrophilic thermoplastic synthetic resin emulsion type adhesive alone or with a thermosetting synthetic resin. Adhesive 2 containing a portion of adhesive is applied.

What is hydrophilic thermoplastic synthetic resin emulsion type adhesive? Emulsion type adhesives such as commonly used vinyl acetate resin emulsion type, ethylene vinyl acetate copolymer resin, acrylic vinyl acetate copolymer resin, SBR, NBR latex type etc. say.

Hydrophilic thermosetting synthetic resin adhesives include urea resins and melamine resins, which can be added in an amount of about 20 parts by weight to thermoplastic synthetic resin adhesives.

If the amount of the thermosetting synthetic resin adhesive exceeds 20 parts by weight, the thermoplasticization of the adhesive in the subsequent process will be insufficient and the adhesive strength with the decorative paper will be impaired, which is not preferable.
The application method and amount of adhesive 2 are the same as before, 50~
It is sufficient if it is within the range of ^about 100g/m2.

Next, the surface of the adhesive 2 is heated at a high temperature of 130° C. or higher to rapidly and sufficiently disperse the moisture in the adhesive 2 to rapidly form a film, and at the same time activate the thermoplastic resin in the emulsion type adhesive. to soften the coating. Heating at a high temperature of 130℃ or higher causes the moisture in the applied adhesive to be rapidly dispersed not only from the surface of the adhesive layer but also from within, thereby activating the molecules of the thermoplastic resin and removing moisture. This is to remove the adhesive sufficiently to form a film rapidly, and to soften the film to exhibit the adhesive strength of the emulsion type adhesive. Therefore, the heating temperature is also 130 to 150℃.
The heating method is preferably one using infrared rays or far infrared rays rather than the conventional hot air method. The heating time may be appropriately determined depending on the type of adhesive used, the amount applied, and the heating method.

Next, thin decorative paper 3 is continuously layered on the surface of the softened adhesive 2 and pressed using one or several heated rolls or a flat press at 120° C. or higher. The thin paper decorative paper 3 is a conventional thin paper of about 15 to 35 g/m ² or is a commonly used decorative paper printed with one or more colors, and the surface of the decorative paper may be coated with a transparent paint in advance.

The pressure bonding is performed using one or more heated rolls or a flat press at a temperature of 120°C or higher, in order to exhibit adhesive strength without lowering the temperature of the softened adhesive.
Usually 130-140, which is the melting temperature of vinyl acetate resin.
The temperature is preferably about ℃ or higher.

As described above, according to the present invention, instead of attaching decorative paper with water contained in the adhesive film as in the past, the water in the adhesive film is rapidly dispersed by high-temperature heating and melted. Because it is bonded with a thermoplastic synthetic resin, the decorative paper does not swell due to the influence of moisture, and it can be adhered smoothly and strongly without being drawn into the vessel groove.

Examples of the present invention will be described below.

Example (1) Natural coating on the surface of lauan plywood (thickness) 2.5mm x (width) 910mm x (length) 1820mm. A vinyl acetate resin emulsion type adhesive was applied at a rate of 80 to 85 g/m ² using a reverse coater. Then, using a dryer with hot air and far infrared rays, four rolls heated to 150°C are heated to 150°C and 23 g/m ² decorative paper is continuously layered on the top surface of which the adhesive is melted by heating and drying at 130 to 140°C for 20 seconds. The desired smooth decorative plywood was obtained by passing through the gap with a linear pressure of 3 tons and crimping.

Example (2) National coating on the surface of lauan plywood (thickness) 4mm x (width) 1230mm x (length) 2450mm. An ethylene copolymerized vinyl acetate emulsion type adhesive was applied at a rate of 75 to 80 g/m ² using a reverse coater. Next, the adhesive is heated and dried for 15 seconds at 160-170℃ using a far-infrared dryer to melt the adhesive and apply 30g/m ² on the top surface.
Continuously layered decorative paper. Then, the desired smooth decorative plywood was obtained by pressing for 45 seconds at a pressure of 3 kg/cm ² using a flat press heated to 130°C.

Example (3) 100 parts by weight of vinyl acetate resin emulsion type adhesive and 10 parts by weight of urea resin adhesive were applied to the surface of lauan plywood of (thickness) 2.7 mm x (width) 910 mm x (length) 1820 mm.
80-85 g/m ² of adhesive added in parts by weight were applied.
Next, a dryer with hot air and far infrared rays produces 125 ~
The adhesive was melted by heating and drying at 135℃ for 30 seconds, then a 30g/ ^m2 unprinted decorative paper was layered continuously on the top surface, and then passed between six rolls heated to 150℃ with a linear pressure of 2 tons. After applying pressure and adhering it smoothly, pale yellow paint was applied to the top surface to obtain decorative plywood.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional decorative plywood, and FIG. 2 is a sectional view showing a decorative plywood of the present invention. 1...Plywood, 2...Adhesive, 3...Decorative paper, 4...Water pipe groove.

Claims (1)

[Claims] 1 After applying a commonly used hydrophilic thermoplastic synthetic resin emulsion type adhesive alone or a mixture of a part of thermosetting synthetic resin adhesive to the plywood surface, heat the adhesive to 130℃.
By heating at a high temperature above, the moisture in the adhesive is rapidly and sufficiently dispersed to rapidly form a film, and at the same time, the thermoplastic synthetic resin in the emulsion type adhesive is activated to soften the film, and the upper surface A method for manufacturing thin paper-attached decorative plywood, which comprises stacking thin paper decorative paper on top of the surface and pressing it with one or several heated rolls or a flat press at 120°C or higher.