JPH02223441A - Manufacture of decorative laminate - Google Patents

Abstract

PURPOSE:To obtain the decorative laminate having no occurrence of wood end-breakage and further capable of being emboss-worked by a method in which a thermosetting emulsion layer is formed first on a wooden base plate, and on said layer, a conventional adhesive layer is formed, and then an a adhesive sheet has been placed on said layer, they are press bonded mutually. CONSTITUTION:The surface of the wooden base plate of a particle board or fiber board, etc., is coated with thermosetting emulsion and is dried. next, the surface of the emulsion is coated with the conventional adhesive such as urea- vinyl acetate synthetic resin or urea synthetic resin. A decorative sheet is placed on said adhesive, and a decorative laminate is obtained by pressure-bonding them. As the thermosetting emulsion, the material in which metallic salt is added into thermoplastic resin, is preferably used. In this decorative laminate, the breakage in the side end part of the decorative laminate due to the shock of a saw does not occur. By using thermosetting emulsion, the uneven emboss pattern due to the heat in pressing under heating may be formed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing decorative laminates.

[Prior Art and Its Disadvantages] Conventionally, in the manufacturing method of this type of decorative board, a common adhesive is applied onto a wooden substrate such as a particle board using a spreader such as a roll coater, and then a decorative sheet is placed.
Decorative boards were manufactured by bonding under pressure using a roll press or flat plate press.

However, when the decorative board is cut with a saw such as a running saw, the impact of the saw causes the side edges of the decorative board to chip (hereinafter referred to as wood edge chipping). Particularly, when a thin decorative paper of 50 g/m 2 or less was used for pasting, chipping of wood edges was noticeable.

[Object of the Invention] The object of the present invention is to eliminate the above-mentioned chipping of the wood end, and also to enable the embossing to be clearly embossed.

[Structure of the Invention] The present invention applies a thermosetting emulsion to a wooden substrate such as a particle board or a fiberboard and then dries it. In this method, a vinyl acetate-based synthetic resin or the like is applied onto the thermosetting emulsion, and then a decorative sheet is placed and bonded under pressure to produce a desired decorative board.

Examples of the wood substrate include boards using wood fibers, wood powder, or wood chips, such as particle board and fiberboard. In addition, as the thermosetting emulsion, for example, reactive monomers such as ethylene glycol diacrylate, N-methylol acrylamide, methylol methacrylamide, or alkoxymethylol methacrylamide, which is an etherification of these, may be added to vinyl acetate. A copolymerized, heat-resistant thermosetting emulsion is desirable. Furthermore, poval, acrylic acid, ethyl acrylate such as ethyl acrylate, emulsion obtained by copolymerizing N-methylolacrylamide with vinyl acetate/acrylic resin, vinyl acetate resin, urea/vinyl acetate resin, etc. A thermosetting emulsion with improved heat resistance by adding a metal salt such as zirconyl nitrate or zinc chloride to the emulsion may also be used. The glass transition temperature (hereinafter referred to as Tg) of the various thermosetting emulsions described above is required to be in a temperature range of 70°C or higher. A thermosetting emulsion having a Tg of less than 70° C. is not preferable because it causes adhesion failure (a phenomenon commonly referred to as puncture) due to the heat generated during heating and pressing as described below.

After the above-mentioned thermosetting emulsion is applied to a wooden substrate, it is forcedly dried by means such as far infrared rays or hot air, and then a urea φ vinyl acetate-based synthetic resin adhesive or the like is further applied to the wooden substrate. The coating amount is preferably in the range of 20 to 100 gem2, and if the coating amount is too large or too small, it will cause poor adhesion and is inappropriate. A decorative sheet, such as titanium paper, mixed paper, resin-impregnated paper, etc., is placed on the wooden substrate coated with the adhesive and bonded under pressure to obtain a decorative board. In addition to applying the above-mentioned urea/vinyl acetate-based synthetic resin adhesive onto the wooden substrate, it may also be applied to the back side of the above-mentioned decorative sheet, or alternatively, to both the top of the wooden substrate and the back side of the decorative sheet. Needless to say, it may be applied by coating.

By the method described above, it is possible to obtain a decorative board that does not suffer from wood edge chipping. In other words, simply applying a thermosetting resin adhesive such as a urea resin adhesive onto a wooden substrate will cause the adhesive to be too hard and cause chips, etc. on the substrate underneath the adhesive to come off due to the impact of the saw. So-called wood end chipping occurs, and wood end chipping can be improved by simply applying a thermoplastic resin adhesive such as vinyl acetate resin emulsion due to the inherent flexibility of this thermoplastic resin adhesive. The problem of poor surface hardness and paper-to-paper strength of decorative boards still remains. Therefore, in view of the above two circumstances, the thermosetting emulsion adhesive according to the present invention is applied to a wooden substrate to form a thermosetting emulsion layer on the surface of the wooden substrate, and then a thermosetting resin adhesive is applied on top of the thermosetting emulsion layer. By forming an adhesive layer and adhering a decorative sheet under pressure, a decorative board that does not cause wood edge chipping can be obtained.

In addition, with decorative boards that are embossed while applying a common adhesive once and then placing a decorative sheet I and adhering under pressure, the adhesive layer itself may be unevenly sucked into the surface of the wooden substrate. Since thickness unevenness occurs, it is difficult to obtain a uniform embossed shape. Since the crosslinking density of the thermosetting emulsion is lower than that of adhesives made of thermosetting resins such as urea resin, it has corresponding thermoplasticity, and when heated and pressed at a temperature of 18 or higher, it will not cause unevenness due to heat. Formation of embossed patterns can be expected. Furthermore, in the present invention, since the thermosetting emulsion layer is dried and a water-based thermosetting resin adhesive is applied thereon, the moisture in this adhesive acts as a plasticizer, and the unevenness caused by the heat is reduced. Embossed pattern formation is encouraged.

In this way, in the present invention, since a layer of a commonly used thermosetting resin adhesive is formed on the dried and hardened thermosetting emulsion layer, the penetration of the commonly used adhesive into the wooden substrate is prevented and the adhesive is uniformly coated. The thickness of the adhesive layer is maintained. Therefore, when the decorative sheet is placed on the adhesive layer 1- and heat-pressed, a decorative sheet having a uniform and clear embossed shape can be obtained.

However, FF sheets with improved surface hardness and interpaper strength (
When adhesively bonding (hard coated paper) to a wooden substrate under pressure, a thermo+if plastic resin adhesive such as a vinyl acetate resin emulsion can also be used instead of the thermosetting resin adhesive layer.

[Effects of the Invention] As described above, the present invention involves forming a thermosetting emulsion layer on a wooden substrate, then forming a common adhesive layer such as a thermosetting adhesive thereon, and Since the decorative sheet is placed on the board and bonded under pressure to obtain the decorative board, the side edges of the decorative board will not be chipped due to the impact of the saw, so-called wood edge chipping. Furthermore, since the commonly used adhesive used in the decorative board described in 1-1 is a thermosetting resin adhesive, in addition to adhering the decorative sheet, it also penetrates into the decorative sheet and improves surface hardness and interpaper strength. ” In addition, as mentioned in the section of the structure of the invention, due to the individual properties of the thermosetting emulsion layer, when heat-pressed and embossed, a decorative board with a clearly and uniformly embossed shape can be obtained. be able to.

[Example 1] 40g/m2Pha of N-methylolacrylamide-modified vinyl acetate emulsion was applied to a 15tm particle board by roll spray and die, and after drying by far infrared heating method, urea/vinyl acetate emulsion was applied on top of it. 50g/m2 of resin adhesive was applied, and titanium paper (30g/m2) was placed and laminated on top of it, and heated at 140°C915
A desired decorative board was obtained by hot pressing at Kgf/m for 25 seconds.

[Example 2] In Example 1, using titanium paper (50 g/m2),
A desired decorative board was obtained using the same method except that the pressing time was changed to 30 seconds.

[Example 3] In Example 1, 20 g/m2 of N-methylolacrylamide-modified vinyl acetate emulsion was applied and 40 g/m2 of urea resin was applied to the back side of titanium paper (30 g/m?), and then the titanium paper was heated to 15 m+n. The desired decorative board was obtained by the same method except for laminating it on particle board and applying matte embossing.

[Example 4] In Example 1, a heat-resistant zirconyl nitrate-modified vinyl acetate emulsion was used as a thermosetting emulsion.
0g/B2 was coated and dried, and then a urea/melamine thermosetting resin adhesive was coated at 20g/m2, and a desired decorative board was obtained in the same manner except for satin finish enhancement and L.

[Comparative Example 1] Urea resin 90g/mz on 15mm particle board
was coated and dried, then laminated with titanium paper (30g/m'), then 140°0, 15Kgf/ml, 2
A decorative board was obtained by hot pressing for 5 seconds.

[Comparative Example 2] In Comparative Example 1, 90 g/m of urea/vinyl acetate resin was used instead of 90 g/m of urea resin, the basis weight of titanium paper was changed from 30 g/m' to 5 (Ig/m2), and the urea resin was changed to 5 (Ig/m2). A decorative board was obtained in the same manner except that the time was changed to 30 seconds.

[Comparative Example 3J In Comparative Example 1, 80 g/m2 of urea resin was applied to a hardboard, and an embossed decorative board was obtained in the same manner except that it was embossed with a satin finish.

"Comparative Test" - The surface properties of the decorative laminates obtained in Examples and Comparative Examples were examined. The results are as follows.

Claims (2)

[Claims] (1) In a method for manufacturing a decorative board obtained by pressure-bonding a decorative sheet to a wooden substrate such as particle board or fiberboard using an adhesive, a thermosetting emulsion is applied to the surface of the wooden substrate and dried. After that, a commonly used adhesive such as a urea/vinyl acetate based synthetic resin adhesive is interposed between the decorative sheet and the decorative sheet. (2) The method for manufacturing a decorative board according to claim 1, characterized in that the thermosetting emulsion is a thermoplastic resin to which a metal salt is added.