JPH0767780B2 - Manufacturing method of molded plywood - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a molded plywood by laminating and integrating a wood veneer and a metal plate, and the wood veneer and the metal plate each have a desired shape in advance. It is preformed, and the powder adhesive is applied to it, then they are laminated and heated and pressed to integrate them, so that a thick and uniform adhesive layer can be obtained. Made it possible to manufacture molded plywood with high durability.

[Prior art and its problems]

Conventionally, a method is known in which an adhesive is applied to a wood veneer and a metal plate such as an aluminum alloy plate to be laminated, inserted into a molding die, heated and pressed, and molded to obtain a molded plywood having a desired shape. ing.

In a molded plywood laminated and integrated with such a metal plate, since the adhesiveness between the wood veneer and the metal plate is insufficient although there is an advantage that a relatively thin material with high rigidity can be obtained,
There is a problem that the veneer peels off or splits after molding, and thus there is a problem that thick wood veneer or metal plate cannot be used. Further, even when used under high temperature or high temperature and high humidity, there is a problem that the wood veneer or the like peels off due to insufficient adhesion durability.

[Means for Solving the Problems] Therefore, in the present invention, a wood veneer and a metal plate are preformed in advance, and a powder adhesive is applied to the wood veneer, which is then laminated and heated and pressed to form an adhesive. The above-mentioned problems were solved by adopting a manufacturing method in which is cured and integrated.

The details will be described below.

First, a wood veneer and a metal plate are prepared. As the wood veneer here, a natural wood veneer having a thickness of 0.2 to 0.8 mm is used, but since it is preformed, a thick veneer having a thickness of 0.5 mm or more can be used without any problem. As the tree species, beech wood or the like having good flexibility is preferable from the viewpoint of moldability, but it is not limited to this. Moreover, it is preferable to use a decorative veneer with a beautiful wood grain pattern as the wood veneer serving as the surface material. Further, as the wood veneer, it is possible to use a wood veneer that has been subjected to a resin treatment to impart flexibility to improve the formability. Examples of the resin treatment include a method of impregnating a wood veneer with an aqueous resin such as vinyl acetate emulsion, EVA emulsion, urethane resin emulsion and drying.

As a metal plate, an aluminum plate with a thickness of 0.2-1 mm,
Although an aluminum alloy plate, a steel plate, etc. are used, an aluminum plate and an aluminum alloy plate are preferable from the viewpoint of easy post-processing. This metal plate is used after being subjected to surface treatment such as degreasing treatment, alkali treatment, acid treatment for improving adhesiveness, primer coating treatment for improving adhesiveness, and phosphate treatment.

Then, the wood veneer and the metal plate are preformed to have a shape substantially the same as the shape of the final product. This molding is performed at a temperature of 25 to 120 ° C. at a pressure of 0.1 to 3 MPa using a molding die. In the case of resin-treated wood veneer, the veneer is wrapped with a release film such as polypropylene film or fluorine resin film. This molding can be carried out not only by molding the wood veneer and the metal plate separately, but also by stacking them simultaneously. In addition, the metal plate may be subjected to the preforming and then the surface treatment.

Next, a powder adhesive is applied to the surfaces of these wood veneer and metal plate. As the powder adhesive here, epoxy resin-based, vinyl chloride resin-based, phenol resin-based, melamine resin-based thermosetting polyester resin-based, thermosetting acrylic resin-based adhesives, etc. are used, among which epoxy A resin-based powder adhesive is preferable, and an epoxy resin-based adhesive using imidazoles as a curing agent is particularly preferable. The powder adhesive is applied by an electrostatic coating method such as an electrostatic spray method or an electrostatic fluidized dipping method, and is applied to both or one side of a wood veneer or a metal plate to form a surface material. The exposed surface of the plate or metal plate is of course excluded. The coating amount is about 50-200 g / m ^{2 on} one side, and the thickness of the adhesive layer after adhesion is about 5
The thickness is adjusted to be about 0 to 200 μm.

Then, the wood veneer coated with the powder adhesive and the metal plate are laminated in a predetermined laminating order, and then the wood veneer is inserted into a molding die and heated and pressed to melt and cure the powder veneer. And the metal plate or wood veneer are bonded together to form the target molded plywood. The heating and pressing conditions at this time differ depending on the type of powder adhesive, the wood veneer, the number of laminated metal plates, etc.
The pressure is usually 0.1 to 3 MPa, the temperature is 60 to 150 ° C., and the time is 10 to 60 minutes.

The molded plywood thus obtained is subjected to various woodworking processes, if necessary, further subjected to surface coloring and surface coating, and then used.

In such a molded plywood, since the wood veneer and the metal plate are preformed, thick ones can be used for these, and even if a thick one is used, the veneer is split,
Does not peel off. In addition, since a rough shape is obtained in advance by preforming, there is no need to apply a very high pressure at the time of heating and pressurizing at the time of bonding and integration, so that the flow of the adhesive is small and a thick wall The advantage of using the powder adhesive that an adhesive layer is obtained can be fully utilized.
Furthermore, since a powder adhesive is used, the adhesive layer can be easily thickened, and since the adhesive layer is thick, this adhesive layer simultaneously functions as a stress relaxation layer, and the adhesiveness, especially under high temperature and high temperature, Improves adhesiveness under high humidity. Also,
Due to its high adhesiveness, the wood veneer or metal plate does not peel off even in post-processing such as cutting and cutting.

〔Example〕

 Hereinafter, the present invention will be specifically described with reference to examples.

(Example 1) A 0.8 mm thick aluminum alloy plate has a thickness on each side.
A 0.5 mm thick beech veneer was further laminated with 0.5 mm thick bird's eye maple decorative veneer on the surface of the beech veneer to prepare a tray-shaped molded alloy with a shallow bottom.

The beech veneer and bird's eye maple decorative veneer were preformed into trays at a water content of about 20% at 80 ° C. and 0.5 MPa for 5 minutes. An aluminum alloy plate was similarly preformed.

Then, a powdered epoxy resin adhesive was electrostatically applied to both surfaces of the preformed beech veneer and the aluminum alloy plate. The coating amount was 100 to 200 g / m ² per side.

The compounding of the powdered epoxy resin-based adhesive is as follows: Epicoat 1001 (Okaka Shell Epoxy Co., Ltd.) 50 parts by weight Epicoat 1055 (Okaka Shell Epoxy Co., Ltd.) 50 parts by weight 2-Ethyl 4-methylimidazole 1 part by weight 2-Undecylimidazole 1 part by weight Behenic acid 0.5 part by weight Aqueous aerosil 0.5 part by weight, and these were melt-mixed and then pulverized to obtain 100 mesh passes.

Laminated aluminum alloy plate and beech veneer veneer and bird's eye maple veneer coated with powdered epoxy resin adhesive according to the above laminating order and insert into a molding die, 140 ° C, 1
It was heated and pressed under the conditions of MPa and 20 minutes, cooled and released to obtain a molded plywood.

After coloring this molded plywood, a non-wax type polyester resin paint was applied and polished.

With respect to this molded plywood, each item of adhesiveness, adhesive workability, crack defect rate, post-processing workability, finished appearance, and comprehensive judgment was examined. The results are shown in Table 1.

(Example 2) beech veneer and Birdseye maple decorative veneer urethane resin Emarujiyon the (Dai-ichi Kogyo Seiyaku Co., Ltd. Super deflection try # 200) was applied at 30 to 50 g / m ² brush, Nde inserted into a polypropylene 60 minutes The resin was cured and further treated by pressing at 100 ° C. and 0.3 MPa for 10 minutes. Using the resin-treated beech veneer and bird's eye maple decorative veneer, a molded plywood was prepared in the same manner as in Example 1, and the same items were examined.

(Example 3) Molded plywood was prepared in the same manner as in Example 2 except that a 50% aqueous solution of a polyethylene glycol monoacrylate resin liquid (Sumitomo Forestry Co., Ltd. Utsudofundeshiyon) was used in place of the urethane resin emulsion. It was created.

(Example 4) A precoated cosmetic material in which a bird's eye maple decorative veneer having a thickness of 0.2 mm was lined with a synthetic resin nonwoven fabric of 30 g / m ^{2 with} a urethane resin adhesive, and the surface was ground to form a colored coating film was used in Example 1.
It was used in place of the 0.5 mm thick bird's eye maple decorative veneer. The pre-molding of this pre-coated decorative material was carried out at 105 ° C. by inserting it into a vinyl fluoride release film. Others were the same as in Example 1 to obtain a molded plywood. Urethane resin paint was applied to the molded plywood to finish polishing.

(Comparative Example 1) In Example 1, the aluminum alloy plate, the beech veneer, and the bird's eye maple decorative veneer were not preformed, but the powder epoxy resin adhesive was applied in a flat plate state. It was created.

(Comparative Example 2) Instead of the powder epoxy resin-based adhesive in Example 1,
A molded plywood was prepared in the same manner by using a liquid epoxy resin adhesive having the following composition.

Araldide 136N (Ciba Geigy) 100 parts by weight Araldide HY-994 (Ciba Geigy) 40 parts by weight Application amount 100-
The molding conditions of 200 g / m ² were 80 ° C., 1.5 MPa, and 30 minutes.

(Comparative Example 3) In Comparative Example 2, an aluminum alloy plate, a beech veneer and a bird's eye maple decorative veneer were preformed. A liquid epoxy resin adhesive was applied in a flat plate state without shaping, and a molded plywood was prepared in the same manner.

As is clear from Table 1, in the case of not preforming,
It can be seen that the wood veneer is cracked and that the one using the liquid epoxy resin adhesive has poor adhesion durability.

〔The invention's effect〕

As described above, the method for producing the molded plywood of the present invention is to preform a wood veneer and a metal plate in advance, apply a powder adhesive to the wood veneer, and then laminate and heat and press them. The wood veneer and the metal plate having a large thickness can be used, and the wood veneer is not split or peeled. Further, since the powder adhesive is used, the thickness of the adhesive layer can be easily increased, the adhesive layer simultaneously functions as a stress relaxation layer, and the adhesive durability becomes high. Further, since the adhesive durability is high, the wood veneer and the metal plate are not peeled off even in the post-processing and the like.

Claims (1)

[Claims] 1. When manufacturing a molded plywood obtained by laminating and integrating a wood veneer and a metal plate, the wood veneer and the metal plate are preformed, and the preformed wood veneer and the metal plate are powder-bonded. A method for producing a molded plywood, which comprises applying these agents and then stacking and heating them.