JPS59196220A - Manufacture of laminate - Google Patents

Abstract

PURPOSE:To facilitate the releasing of mirror plates, by placing a prescribed sheets of prepreg layer upon layer that have been impregnated with a thermosetting resin, placing them between mirror plates with biaxially stretched films inserted between the mirror plates and them, and heating and pressing them. CONSTITUTION:In a case wherein a prescribed sheets of prepreg that have been obtained by impregnating base materials with a thermosetting resin followed by drying are placed layer upon layer, the prepregs are sandwiched between mirror plates, and they are heated and pressed to obtain a laminate, biaxially stretched synthetic resin films are inserted between the prepregs and the mirror plates. Thus by inserting the biaxially stretched synthetic resin films between the prepregs and the mirror plates, which films are hardly shrunk and would not be shrunk in one direction when heated and pressed, the releasing of the mirror plates can be easily performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a laminate that can be quickly released from a mirror plate.

A laminate is manufactured by stacking a predetermined number of prepregs obtained by impregnating and drying a thermosetting resin into a base material, sandwiching the prepregs between mirror plates, and applying heat and pressure. After cooling, the mirror plate is removed (dismantled), but it is difficult to release the mirror plate from the mold, especially for epoxy resin laminates, so a synthetic resin film is interposed between the prepreg and the mirror plate to release the mold. I'm making it easy.

However, the problems with this method are as follows.

(1) The film interposed between the prepreg and the mirror plate may shrink when heated and pressurized, resulting in poor mold release of the mirror plate. To prevent this, it is possible to increase the film size, but there is a tendency for the film to get caught when being fed into the press.

(2) Since the above-mentioned film has a directional shrinkage, the mirror plate and the prepreg may slip in the shrinking direction of the film during heating and pressing, and there is a risk that one of them may pop out from between the press hot platens.

The present invention provides a method for producing a laminate in which the mirror plate can be smoothly released from the mold without causing the above-mentioned troubles during heating and pressing.

That is, in the present invention, the synthetic resin film interposed between the prepreg and the mirror plate is made of biaxially rolled tallate, etc., and shrinkage during heating and pressing is small (and the shrinkage does not occur in one direction).

Next, one aspect of the present invention will be explained in detail.

Example prepreg (epoxy resin impregnated glass cloth base material, size 1
A biaxially stretched polypropylene film (size 101,070 x 107
Q.

The temperature was 160°C, with a thickness of 40μ) interposed.

The mixture was heated and pressurized at a pressure of 1009/c for 1 hour. the result,
Although the polypropylene film shrank to 101065 x 1065, no slipping occurred and the mold releasability was good.

Comparative example Uniaxially stretched polypropylene film (size 1070X1
070, thickness 40 μm), and heat and pressure molding was performed in the same manner as in the example except for the following. As a result, the polypropylene film shrunk in one direction to 10'75 x 1055.

The specular plate and the prepreg came into contact with each other in some areas, resulting in defective mold release. As mentioned above, in the present invention, the shrinkage force of the film interposed between the prepreg and the specular plate is 1 tJX, N, resulting in defective mold release. There is no need to use large size 0 film, so there is no risk of trouble when inserting it into the press heating plate (1°) Also, the above film shrinks in one direction (there is no force), so prepreg and mirror plate pickpocket]
Its industrial value is extremely high, as it does not cause any problems.

patent applicant

Claims (1)

[Claims] A method for manufacturing a laminate in which a predetermined number of prepregs obtained by impregnating and drying a thermosetting resin on a base material is sandwiched between mirror plates and heated and pressed, in which a biaxially stretched synthetic resin film is interposed between the prepreg and the mirror plate. A method for manufacturing a laminate, characterized by the following.