JPS6144832Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention relates to the structure of painted plywood by improving the hardened paper layer impregnated with a thermosetting synthetic resin for the paint film base that is adhered to the core material, thereby reducing the thickness of the hardened paper layer. The present invention aims to improve moisture barrier performance, and to obtain lightweight and inexpensive plywood.

Conventionally, in this type of painted plywood, as illustrated in FIG. 1, a thermosetting synthetic resin liquid such as phenol resin, polyester resin, epoxy resin, or diallyl phthalate resin is applied to a core material 1 such as plywood or particle board. A structure is known in which a cured paper layer 2 impregnated with and cured is adhered as a base layer for a coating film, and a coating film 3 is applied and formed on the surface of the cured paper layer 2.

Compared to plywood of this conventional structure, which uses a decorative veneer made of natural wood and is surface-painted, the undercoating and sanding processes can be omitted, and the core material is also easily available. Although it has advantages such as being able to process it at low cost and being able to obtain a durable finish, the thickness of the hardened paper layer 2 must be at least 1.0 mm, preferably 1.3 mm or more, which increases the overall weight. However, it is not only expensive, but also has drawbacks such as deterioration of the wood quality of the plywood.

Therefore, in order to compensate for the drawbacks of the conventional plywood mentioned above,
When the thickness of the cured paper layer 2 is reduced, its moisture blocking ability decreases, and as a result, the core material made of wood absorbs and expels moisture from the outside air, swells and contracts, and the surface of the coating film 3 There were problems such as the occurrence of minute irregularities and the inability to achieve a beautiful smooth surface such as a mirror finish.

This invention is aimed at solving the above-mentioned conventional drawbacks, and will be explained below based on the embodiment shown in FIG.

As shown in FIG. 2, numeral 10 in the figure is a painted plywood in which a hardened paper layer 12 impregnated with a thermosetting synthetic resin is adhered to a core material 11 such as plywood or particle board, and a coating film 13 is applied thereon. A metal foil 14 made of aluminum foil is interposed in the paper layer 12 through a manufacturing process described later, and countless minute holes 15 are formed in the metal foil 14.
It has a configuration in which a hole is provided.

That is, in order to manufacture the above-mentioned painted plywood 10,
A metal foil 14 is sandwiched between multiple sheets of impregnated paper impregnated with a thermosetting synthetic resin liquid such as phenol resin, polyester resin, epoxy resin, or diallyl phthalate resin, and the metal foil 14 is formed into a mold for heating at a desired high temperature and applying high pressure. A thin plate-shaped cured paper 12 is separately formed in advance by heat-pressure curing in a wafer, and then the adhesive side surface of the cured paper 12 is sanded, and then the cured paper 12 is pasted onto the core material 11 using an adhesive. Ru. Then, after sanding the opposite surface of the cured paper 12 adhered to the core material 11, a coating film 13 is formed on the surface.

By the way, in the above example, the thickness of the cured paper layer constituting the painted plywood was 0.2 to 0.5 mm, and the thickness of the metal foil was 0.10 to 0.3 mm, including the adhesive layer.
The metal foil is formed to have an overall thickness of 0.6 to 1.0 mm, and it is more preferable to apply a surface treatment for adhesion to the surface of the metal foil that is sandwiched between the impregnated papers during thermoforming of the hardened paper. . Furthermore, when making minute holes in metal foil, the holes are made so that they are evenly distributed over the entire surface, and in the case of circular holes, the diameter of the holes is 1.
mm or less, preferably 0.5 mm or less.

Therefore, according to the above-mentioned configuration according to this invention, since the metal foil is interposed in the thermosetting synthetic resin-impregnated hardened paper layer that is adhered to the core material, the moisture barrier performance can be prevented without decreasing. Since the thickness of the hardened paper layer can be reduced, the weight can be reduced, and this also facilitates bending, making it possible to manufacture curved plywood. Also,
Since the metal foil has minute holes, it has a slight moisture permeability, so even if it is left in high humidity outside air for a long time, the cured paper layer will not swell or the metal foil and the cured paper layer will separate. Moisture does not aggregate or stay at the interface, reliably preventing the occurrence of unevenness on the surface of the coating film, and the moisture permeability of the plywood can be freely changed by adjusting the area of the perforations, even if it is thin. It has moisture resistance similar to that of thick plywood, and has excellent durability and aesthetic effects.

Specific example: In a laminate made of aluminum foil sandwich phenol resin with a hardened paper layer of 0.6 mm, the aluminum foil has 16 through holes with a radius of 0.3 mm per ¹ cm2, 4 holes in the vertical direction and 4 holes in the horizontal direction. When holes were uniformly drilled throughout the material, moisture permeability comparable to that of a phenolic resin laminate with a thickness of 1.15 mm was obtained.

When this laminate was glued to a lauan core material and the surface was painted with black enamel using unsaturated polyester resin, a plywood that was durable against changes in the surrounding environment was obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part of an example of a conventional coated plywood, and FIG. 2 is a cross-sectional view of a main part of an embodiment of a coated plywood according to the present invention, partially enlarged. 10... Painted plywood, 11... Core material, 12... Cured paper layer, 13... Paint film, 14... Metal foil, 15...
...Minute pores.

Claims (1)

[Scope of Claim for Utility Model Registration] A coated plywood in which a hardened paper layer impregnated with a thermosetting synthetic resin is adhered to a core material and a coating film is formed on the surface of the hardened paper layer, in which minute holes are formed in the hardened paper layer. Plywood characterized by having perforated metal foil interposed therebetween.