JPH0790621B2 - Foam plastic composite board - Google Patents

Description

TECHNICAL FIELD The present invention relates to a foamed plastic composite plate in which a foamed plastic layer is used as a core material and metal plates are bonded to both surfaces thereof.

[Conventional technology]

A composite plate in which a synthetic resin such as polyolefin is bonded as a core material between two metal plates made of aluminum, iron, stainless steel or the like is well known (see, for example, Japanese Patent Publication No. 39-4739).

Since this type of composite plate has the properties of both metal and synthetic resin, it has various features such as light weight, impact resistance, and ease of processing. Applications include building materials, interior / exterior members, etc., and various improvements suitable for each application have been made.

[Problems to be solved by the invention]

In order to improve the lightness and heat resistance of a composite plate and to make it more economical, it has been practiced to foam a synthetic resin of a core material. In this case, when a metal plate having a thickness of about 0.2 mm is used and the expansion ratio of the synthetic resin is increased, the metal surface of the composite plate is apt to be depressed due to pressure or impact, which causes a problem of reduction in surface pressure strength.

For example, use a synthetic resin such as polyethylene and adjust the expansion ratio.
When it is 1.3 times or more, the surface pressure strength of the composite plate is so low that it is difficult to put it to practical use. Therefore, the synthetic resin is crosslinked. Although the foamed plastic itself is improved by increasing the hardness of the material, etc.
If it is more than double, it is difficult to obtain a composite plate having a practical surface pressure strength.

Heretofore, in the case of a composite plate composed of a foamed plastic having a higher expansion ratio and a metal plate, the metal plate has been thickened to increase the surface pressure strength. However, due to this, there is a problem that the composite plate becomes heavy even though the foamed plastic is used, and the price also rises. Therefore, a composite plate having both light weight and high strength has been demanded.

[Means for solving problems]

The present inventors have made various studies in view of the improvement of the foamed plastic composite plate, and as a result of interposing an ordinary synthetic resin layer between the foamed plastic layer and the metal plate, a lightweight and high-strength composite plate is obtained. The present invention has been reached by knowing that it can be obtained.

That is, the gist of the present invention is to provide a composite plate in which metal plates are bonded to both sides of a foamed plastic layer, the expansion ratio of the foamed plastic is 2 times or more, and there is no foaming state between the foamed plastic layer and the metal plate. And a thickness of the metal plate is 0.03 to 0.3 mm, and a thickness of the synthetic resin layer is 0.1 to 1.0 mm.

Hereinafter, the present invention will be described in detail.

As the resin constituting the foamed plastic, any resin can be used as long as it can be foamed to obtain a hard foam. Specifically, as foamed plastic, foamed polyurethane,
Examples thereof include expanded polystyrene, expanded vinyl chloride resin, expanded polyethylene, expanded phenolic resin, expanded urea resin, and the like. In particular, expanded polyurethane is preferable because it has large mechanical strength and elasticity.

When the expansion ratio of the foamed plastic is 2 times or more, the significance of the present invention arises. Below that, the surface pressure strength of the obtained composite plate is practically sufficient. Therefore, it is necessary to provide a synthetic resin layer described later. Lost. It is preferably 5 times or more, and particularly preferably 10 times or more. The upper limit of the expansion ratio is not particularly limited, but it is preferably 40 times or less in order to prevent the strength of the composite plate from decreasing. The thickness of the foamed plastic layer may be appropriately determined according to the desired thickness of the composite plate, but usually 1
Approximately 50 mm.

As the metal plate bonded to both surfaces of the foamed polyurethane layer, a metal plate made of a metal such as aluminum, iron, copper, titanium, tin, nickel or an alloy thereof is used. Particularly, it is preferable to use a plate made of aluminum, iron or stainless steel. The thickness of the metal plate is 0.03 to 0.3 mm in order to reduce the weight of the composite plate obtained from this and to bring about the effect of the present invention.
And In particular, iron and stainless steel have high strength, and therefore the thickness is preferably 0.15 mm or less.

The present invention is characterized in that the synthetic resin layer is interposed between the foamed plastic layer and the metal plate, which makes it possible to obtain a composite plate excellent in lightness, rigidity and surface pressure strength.

There is no limitation on the synthetic resin constituting the synthetic resin layer, and any synthetic resin that can be used for ordinary extrusion molding can be used in a substantially non-foamed state. For example, polyolefin, polyvinyl chloride, polyamide, polycarbonate,
Examples thereof include polystyrene, polyhydroxy ether, vinyl acetate and the like, and from the viewpoint of moldability, a polyolefin resin, particularly polyethylene, polypropylene is preferable. The thickness of the synthetic resin layer is 0.1 to 1.0 mm. If it is too thin, the significance of providing the synthetic resin layer is lost.

The composite plate of the present invention comprises the above-mentioned foamed plastic layer, metal plate and synthetic resin layer, which are joined and integrated in a structure of metal plate-synthetic resin layer-foamed plastic layer-synthetic resin layer-metal plate. Yes, the total thickness is typically 2-50 mm, but is not limited to this depending on the application.

The method for producing the composite plate is not particularly limited as long as it is in the order of laminating, and conventionally known methods including a continuous method and a batch method are possible. For example, a foamed plastic layer formed into a sheet shape, a method of joining a synthetic resin layer to a metal plate by thermocompression bonding, a method of supplying a raw material mixture of the foamed plastic or a synthetic resin in a molten state between the metal plates are possible. .

In particular, the molten synthetic resin is supplied to the metal plate to form a synthetic resin layer on the metal plate, and the raw material mixture of the foamed plastic is continuously injected between the pair of metal-synthetic resin bonded bodies, and then, A method of obtaining a desired composite plate after the reaction of the foamed plastic is completed after foaming is industrially extremely preferable because continuous production is possible.

At the time of manufacturing the composite plate, an adhesive may be used for bonding between the layers, and if possible, it may be simply thermocompression bonded. When a polyolefin resin is used as the synthetic resin and a polyurethane foam is used as the foamed plastic, since the both do not have adhesiveness, it is possible to interpose a thin paper-like material such as waterproof paper between them for adhesion.

Incidentally, the synthetic resin layer and the foamed plastic layer of the present invention,
UV stabilizers such as stabilizers, lubricants, carbon black,
Various additives such as antioxidants can be added.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

Example A high density polyethylene in a molten state was supplied onto each of two aluminum plates having a thickness of 0.15 mm to coat them as a layer having a thickness of 0.3 mm. The aluminum plates coated with the obtained high-density polyethylene are placed so that the coating surfaces face each other, and the raw material mixture of foamed polyurethane is injected between them, and then the whole is placed in a mold with a space height of 3 mm to foam polyurethane. Let and thickness 3
A composite plate having a polyurethane foaming ratio of 6.4 times was obtained.

On the obtained composite plate, small spheres having a diameter of 1/8 inch (3.18 mm) were pressed and held for 20 seconds under a static load of 7 kg, and the depth of the recess was measured to measure the surface pressure strength. The average of 10 measurements is shown in the table below.

Comparative Examples 1 to 3 Composite plates having a thickness of 3 mm were obtained in the same manner as in Examples except that high-density polyethylene was not used and the expansion ratio of polyurethane was changed as shown in the following table.

The surface pressure strength of each of the obtained composite plates was measured. The results are shown in the table below.

[Effects of the Invention] The foamed plastic composite plate of the present invention has high heat insulation properties and sound insulation properties similar to the conventional products, and is extremely lightweight, yet has rigidity, surface pressure strength, impact resistance and the like. Since it is excellent in strength, it is industrially extremely useful.

Claims (1)

[Claims] 1. A composite plate obtained by bonding metal plates to both sides of a foamed plastic layer, wherein the foamed plastic has a foaming ratio of 2 or more, and a synthetic resin in a non-foamed state between the foamed plastic layer and the metal plate. A foamed plastic composite plate, wherein a layer is interposed, the thickness of the metal plate is 0.03 to 0.3 mm, and the thickness of the synthetic resin layer is 0.1 to 1.0 mm.