JPS5842457A - Manufacture of decorative plywood - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing decorative plywood in which the occurrence of cracks in decorative surface materials is extremely reduced.

Conventional general decorative plywood is made by layering thin sheets of Japanese pine, Japanese toga, etc., coated with an adhesive and one of which is pre-impregnated with a thermosetting resin solution. This was made by heat-pressure welding. However, in the above method, it was not possible to form a uniform adhesive layer because the adhesive penetrated into the conduit of the wood base material during thermopressure bonding. For this reason, stress due to expansion and contraction of the wood base material is locally concentrated on the surface decorative material at non-uniform areas of the adhesive layer, causing cracks to occur in those areas. In addition, unevenness in the adhesive layer reduces the adhesive strength, and as a result, the surface decorative material tends to peel off.However, if a large amount of adhesive is applied, it not only takes a long time to bond, but also causes the adhesive layer to peel off easily. Excessive adhesive may seep out and be wasted, and may also cause problems such as spoiling the aesthetic appearance.

Therefore, the present invention can prevent the surface decorative material from cracking and also prevent the surface decorative material from peeling off. The purpose is to provide a method for manufacturing vanity units. In order to achieve this object, the present invention has a structure in which a metal foil having a large number of holes is adhered to the surface of a plywood board with an adhesive. It is characterized in that a surface decorative material impregnated with a saturated polyester resin is layered on the surface of the metal foil and bonded under heat and pressure. The adhesive used in the present invention is not limited to those mentioned above, but includes plasticizers, fillers, etc. in the adhesive composition.
There is no problem in adding modifiers, additives, etc. Furthermore, the adhesive may be applied by scattering a powder or by applying a liquid with a brush or the like. Further, the amount of coating may be adjusted as appropriate. Decorative wood veneers such as Japanese pine and Japanese toga are used as surface cosmetics. Various types of metal foil can be used, such as iron foil, steel foil, and aluminum foil, but iron foil is the most preferable in terms of workability, adhesion, crack resistance, and economic efficiency, especially if galvanized. It also has excellent durability and rust prevention properties.

Its thickness is set to 0.
The distance is preferably about 0.01 to 0.08 m. In addition, the lower limit of the occupancy rate of the holes provided in the metal foil to the metal foil is set at approximately 10% in consideration of the diffusion of water vapor generated during hot pressure, and the upper limit is set at approximately 50% in order to not drastically reduce the strength of the metal foil. It is better to use %. The shape of the holes is preferably circular in order to avoid stress concentration on the metal foil, and the size is preferably between 2.0 and 20.0 - in terms of area, and a large number of holes are preferably scattered at equal intervals. is good.

In the method of the present invention, the metal foil provided between the plywood and the surfacing grip absorbs stress from contraction and expansion due to moisture absorption and desorption of the plywood, making it difficult to have an adverse effect on the surface cosmetics and preventing cracks. Occurrence becomes extremely rare. Furthermore, the adhesion to plywood and decorative surface materials is also significantly improved because the adhesive penetrates into the pores of the metal foil.

Example 1 The cross-sectional structure of the decorative plywood of this example is shown in FIG. 1. As shown in FIG.
0.001//m, and on top of this, coated with iron foil (metal foil) 3 with a thickness of 0.05 m and a diameter of 3.
The mvi circular holes 4 were arranged at almost equal intervals and the occupancy rate of the circular holes 40 to the total area of the iron foil 3 was 20%, and the conditions were 120° C. and 6 k#/d. Glue the string for 15 minutes. At this time, the water vapor evaporates efficiently from the circular holes 4, and the adhesive 2 extends to the circular holes 4, so that the adhesive force of the iron foil 3 to the plywood 1 is sufficiently increased. Furthermore, apply the same adhesive 2 as above on this iron foil 3 at 100.1i+
/'m'', then immersed in a resin solution containing 100 parts by weight of unsaturated polyester resin and lit part benzoyl peroxide in advance, and applied the resin solution under a reduced pressure of 3 to 20 uJ (H). 0.6III thick Japanese pine veneer (surface decorative paulownia) 5 impregnated with 120° C. and 6°C for 15 minutes under heat-pressure bonding to obtain a decorative plywood. When a plane peel test was performed on the decorative plywood, the base material was destroyed, and its good adhesion was confirmed.This decorative plywood also received the Ministry of Agriculture, Forestry and Forestry Notification No. 165 of 1971.
The cold and heat cyclic B test specified in No. 0 was conducted, but the temperature was 80℃.
Even after repeating the treatment twice for 2 hours and 2 hours at -20°C, no cracks were generated at all.

Example 2 In this example, as in Example 1, FIGS.
This will be explained using figures. Adhesive 2, which is a mixture of 100 parts by weight of unsaturated polyester resin and 5 parts by weight of penzoyl peroxide, is applied uniformly to plywood 1 at a ratio of 100V'1rl, and a circular hole with a thickness of 0.08 mm and a diameter of 5 mm is formed on the plywood 1. A steel foil 3 in which 4 occupies 10% of the total area is pasted, and the same adhesive 2 used in Example 1 is evenly applied on top of it at a rate of 10017 m. The same Japanese pine veneers 5 as used were overlapped and bonded under hot pressure at 120° C. and 6 kg/cIi for 15 minutes. When the decorative plywood thus obtained was subjected to the same tests as in Example 1, no peeling was observed and no cracking was observed.

Comparative Example 1 When iron foil having no holes was used under the same conditions as in Example 1, the American pine veneer peeled off at the interface and its adhesion was poor.

Comparative Example 2 Instead of using metal foil as in the past, just double the amount of adhesive and apply it evenly on plywood at a ratio of 2009/rrl, and then overlay a Japanese pine veneer on top of it and heat it at 120°C. ,
After heat-pressure bonding for 15 minutes under the conditions of 6 kg A-II, a plane peel test was performed and no peeling was observed, but a large amount of cracking occurred in the cold/heat cycle B test.

As explained above, according to this method, a metal foil with holes formed between the base material and the decorative surface material is interposed and these are bonded together, thereby improving crack resistance and adhesion. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic structure of decorative plywood made by the method according to the present invention, and FIG. 2 is a perspective view of the metal foil. In the drawing, 1 is plywood, 2 is adhesive, 3 is iron foil, 4 is hole, and 5 is surface decorative material. Figure 1 Figure 2 323-

Claims (1)

[Claims] A metal foil with a large number of holes is attached to the surface of the plywood using an adhesive, and then the adhesive is applied to the surface of the metal foil, and a surface decorative material pre-impregnated with an unsaturated polyester resin is applied to the metal foil. A method for manufacturing decorative plywood, characterized in that the decorative plywood is layered on the surface and bonded under heat and pressure.