JPH0237536Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a mold for producing molded products of plastic foam or rubber foam for use in cushions for vehicles, furniture, etc.

Generally, in this type of mold, a release agent is applied to the inner surface of the mold in advance, and then a plastic foaming stock solution, such as a polyurethane foaming stock solution, is poured into the mold, sealed, and foaming and curing are performed by heating or at room temperature. A foam molded product of a predetermined shape is obtained. However, if the mold is used for a long period of time, the wax etc. normally contained in the mold release agent will accumulate on the inner surface of the mold and combine with a part of the foaming stock solution to form scale, resulting in the failure of the specified foam molded product. will not be able to obtain it. For this reason, the scale must be removed periodically, which requires a lot of trouble.

It has also been proposed to apply a silicone rubber layer with excellent mold release properties as a mold release agent, but this has the disadvantage that it peels off from the mold during short-term use.

In the present invention, as a result of intensive research aimed at improving these drawbacks, we have discovered a molding die that can be used for a long period of time and is provided with a mold release agent layer that does not generate scale or the like. That is, in the present invention, a glass cloth is interposed in a composite layer of a thin silicone resin layer and a thin epoxy resin layer to form a bonded base, and a reinforcing material such as glass cloth or metal powder is heated on the outside of the epoxy resin layer. It is characterized by a reinforcing layer impregnated with a curable resin and then cured, which is brought into close contact with the reinforcing layer.

The reason why the reinforcing layer is provided in the present invention is that when the above-mentioned base alone is injected into the mold for foaming by injecting the plastic foaming stock solution into the mold, it deforms under the foaming pressure and it is not possible to obtain the desired foamed molded product. A reinforcing layer is brought into close contact with the base to strengthen the base.

In this case, thermosetting resin such as epoxy resin or polyester resin alone has little effect, so it is formed by mixing reinforcing substances such as glass tip metal powder or glass cloth.

Note that the thickness of the reinforcing layer is usually 5 to 10 mm.

Also, if only a thin layer of silicone resin is used on the base,
Since there is a risk of scratching or peeling, the epoxy resin is composited with a glass cloth interposed therebetween. Furthermore, the glass cloth embedded in the composite layer cannot achieve its reinforcing purpose unless it is interposed between both the silicone resin thin layer and the epoxy resin thin layer. This can be achieved by providing one part of the silicone resin layer and the other part of the silicone resin layer so as to span the epoxy resin thin layer.

The thickness of the silicone resin layer is usually 2 to 3 mm.
The thickness of the epoxy resin layer is usually about 3 to 5 mm.

Next, an example of the present invention will be explained based on the drawings.

FIG. 1 is a sectional view showing an example of the mold forming die of the present invention, and FIG. 2 is an enlarged sectional view of section A in FIG. 1. That is, a glass cloth 4 is embedded in a silicone resin 3 having a thickness of about 2 mm so that its peaks protrude from the silicone resin layer, and an epoxy resin 5 is applied to the outside thereof to form a base 2. On the outside of the epoxy resin layer 5,
The mold for the present invention was obtained by impregnating a glass tip with epoxy resin and then hardening the reinforcing layer 1 having a thickness of about 7 mm.

Note that 6 is packing.

Therefore, when a urethane stock solution is injected into the mold of the present invention and heated or foamed at room temperature to form a urethane foam molded product, the silicone resin layer does not transfer to the foamed product, so foaming is not possible as in the conventional method. There is no need to apply silicone resin each time a molded product is molded, and it can be used as is many times, so there is no need for the complicated process of applying a mold release agent, and it is an expensive silicone resin. It can be manufactured at low cost since only a small amount of is needed. Furthermore, since scale is not generated from within the mold release agent, there is almost no problem caused by this, and there are remarkable effects such as no need for cleaning the mold at all.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the mold for the present invention, and FIG. 2 is an enlarged sectional view of section A in FIG. DESCRIPTION OF SYMBOLS 1...Reinforcement layer, 2...Base, 3...Silicone resin layer, 4...Glass cloth, 5...Epoxy resin layer.

Claims (1)

[Scope of utility model registration request] A glass cloth is interposed in the composite layer of a silicone resin thin layer and an epoxy resin thin layer to form a bonded base, and a reinforcing material such as glass cloth or metal powder is attached to the outside of the epoxy resin thin layer and thermosetting material is added. A molding die characterized by closely adhering a reinforcing layer impregnated with resin and then cured.