JPH11320593A - Manufacture of laminate and molding plate used for the manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a laminate having a small warpage and to reuse a mold releasable material by using a metal plate having better thermal conductivity than that of a stainless steel as a molding plate brought into direct contact with a prepreg layer of the laminate, and coating a contact surface of the plate with a mold releasable resin. SOLUTION: A plurality of sets each sandwiching a layer 1 of a prepreg obtained by impregnating a sheet-like fiber base material with a thermosetting resin and drying it between molding plates 3 via a mold releasable resin film or a mold releasable metal foil 2 are provided. After the plural sets are inserted between heating platens in a superposed state on a carrier plate 4 via a cushioning material 5, it is heat pressure molded to manufacture the laminate. In this case, a metal plate made of an aluminum having good thermal conductivity than that of a stainless steel is used as the plate 3 in contact with the layer 1, and a surface of the plate 3 opposed to the layer 1 is coated with a mold releasable resin such as a silicone resin or the like. Thus, a warpage at the time of molding is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate in which a prepreg layer obtained by impregnating and drying a sheet-like fiber base material with a thermosetting resin is sandwiched between molding plates and heated and pressed between hot plates. The present invention relates to a method for manufacturing a board. On one or both sides of the laminate,
A metal foil such as a copper foil is integrated as needed during the heat and pressure molding. However, the present invention is particularly applicable to a laminated plate in which the metal foil is not integrated on both surfaces or the metal foil is integrated only on one surface. It is a method suitable for the production of The present invention also relates to a molding plate used for manufacturing such a laminated board.

[0002]

2. Description of the Related Art Laminated sheets are prepared by impregnating and drying a sheet-like fiber base material with a thermosetting resin to advance the curing of the thermosetting resin to a B stage, and applying the prepreg layer to a molding plate. It is manufactured by sandwiching and heating and pressing this between hot plates. FIG. 1 shows a state in which a plurality of laminated plates are formed between hot plates. A release resin film or a release metal foil 2 is disposed on both sides of a prepreg layer 1 which is stacked by a number necessary for manufacturing one laminate, and this is placed on a pair of forming plates 3. Between them. The plurality of sets are superimposed on the carrier plate 4, put between hot plates, and heated and pressed through the cushion material 5. The molding plate is for imparting smoothness to the surface of the laminate,
Usually, it is made of a stainless steel plate having high hardness without rusting.
In addition, a metal foil such as a copper foil is integrated on one or both sides of the laminate as needed during the heat and pressure molding, but the metal foil is not integrated on both sides or the metal foil is integrated only on one side. In the production of a laminated board to be formed, as shown in FIG. 1, a release resin film or a release metal foil is arranged on a prepreg layer, whereby the molded laminate and the molding plate are separated. It prevents sticking.

[0003]

Since a forming plate made of a stainless steel plate has a low thermal conductivity, if it is arranged between hot plates, the temperature gradient in the laminating direction becomes large. When a laminate is formed using such a molding plate, thermal distortion during heating and cooling remains in the laminate, and the laminate tends to warp. In addition, since the mold release resin film or mold release metal foil adheres to the molded laminate, a new mold release resin film or mold release metal foil is required for each molding, and the mold release resin film or The releasable metal foil is peeled off from the laminate after molding and discarded. The problem to be solved by the present invention is to use a forming plate made of a stainless steel plate,
Another object of the present invention is to manufacture a laminate having a small warpage, which enables repeated use of a release material.

[0004]

In order to solve the above-mentioned problems, a method of manufacturing a laminated board according to the present invention uses a metal plate having better heat conductivity than stainless steel as a forming plate directly in contact with a prepreg layer. I do. Then, the mold release resin is applied to the surface of the metal plate to be used which faces the prepreg layer. When a metal plate having better heat conductivity than stainless steel is used as a forming plate, the temperature difference in the thickness direction of the prepreg or the laminated plate formed by molding the prepreg during heating / cooling becomes small, and no thermal distortion remains in the laminated plate. Warpage and deformation of the laminate can be reduced. Since the release resin applied to the surface of the metal plate is not easily peeled off from the molding plate, it can be used repeatedly.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The forming plate used in the method according to the present invention is made of aluminum, copper, or an alloy containing these, which has better heat conductivity than stainless steel.
The release resin applied to the surface of the molding plate is a silicone resin or a fluororesin. The production of the laminated board is performed by sandwiching a prepreg layer between molding plates, and then heating and press-molding the prepreg layers. Therefore, the mold release plate may be coated with the release resin on the surface facing the prepreg layer. However, when a plurality of laminated plates are formed between hot plates as shown in FIG. 1, the forming plate located in the middle serves as a forming plate for forming the laminated plates located on both sides thereof. Fulfill. From such a viewpoint, it is advantageous that the mold release plate is coated with a release resin on both sides. When the thickness of the molding plate is reduced, the formation of the sheet-like fiber base material used in the prepreg is transferred, and the surface of the laminated plate is unevenly formed to impair the appearance. When using a forming plate made of an aluminum plate, the thickness of the forming plate is set to 0.3 mm or more when the sheet-like fiber base material is a woven fabric,
In the case of a non-woven fabric, the thickness is preferably 0.7 mm or more.

In order to manufacture a laminated board, first, a prepreg in which a thermosetting resin is impregnated and dried in a sheet-like fiber base material and curing of the thermosetting resin is advanced to a B stage is manufactured. The sheet-like fiber substrate is a woven fabric, a nonwoven fabric, or a mat made of paper, natural fibers, organic synthetic fibers, inorganic fibers, and the like, and is not particularly limited. The thermosetting resin is a phenol resin, an epoxy resin, a polyester resin, or the like, and is not particularly limited.

When the metal foil is integrated on only one side or the metal foil is not integrated on both sides when the prepreg layer is heated and pressed, the above-mentioned molding plate is used to form the prepreg coated surface with the release resin. Abut directly on the layer.

[0008]

EXAMPLE An aluminum plate (thickness 0.38 mm, coefficient of thermal expansion 12.8)
A molding plate was prepared by applying a silicone resin to a thickness of 20 μm on both surfaces having a PPM / ° C. and a thermal conductivity of 0.00203 BTU / sec. A prepreg layer having a resin content of 35% by weight obtained by impregnating and drying an epoxy resin varnish on a glass woven fabric is sandwiched between the molding plates, and a plurality of sets of the prepregs are
As shown in FIG.
cm ^2, 180 minutes at a temperature 165 ° C. by heating and pressing the laminate (size: 1000 × 1000 × 0.4mm) was prepared.
Even after the forming plate was repeatedly used five times in the production of the laminated plate, the releasability of the laminated plate and the forming plate was good, and no decrease in the releasability from the beginning was observed. There was no problem with the state of the silicone resin coating film applied to the molding plate and the appearance of the molded laminate. And this molding plate can be further used.

Conventional example SUS630 (thickness: 1.0 mm, thermal conductivity: 0.0014B)
(TU / sec) was used as a molding plate, and a laminate was produced in the same manner as in the example. A polypropylene film was interposed between the molding plate and the prepreg layer as a release resin film.

Table 1 shows the results of measuring the warpage of the laminates manufactured according to the above embodiment and the conventional example. In this method, the formed laminate was placed on a flat surface, and the amount of lift from the flat surface at the four corners of the laminate was measured.

[0011]

[Table 1]

The above embodiment is an example of manufacturing a laminated board in which metal foils are not integrated on both surfaces. In the above example, when a laminated plate in which a metal foil (copper foil) was integrated on one side was similarly manufactured, the molding plate could be used repeatedly as in the above example.

[0013]

As described above, according to the method of the present invention, the heat conduction during the molding of the laminate is accelerated to make the heat distribution uniform,
Warpage of the laminate can be suppressed to a small value. Further, since the molding plate having the surface coated with the release resin is used repeatedly, it is not necessary to newly prepare a release resin film or a release metal foil for each molding cycle. Further, a molding plate made of a stainless steel plate is used together with a release resin film or a release metal foil, from which dirt is transferred. The sheet thickness is set to 1 mm or more because it is necessary to perform mechanical polishing each time it is used. On the other hand, the molding plate according to the present invention does not need to be polished each time it is used, so that the plate thickness can be reduced. As a result, the number of sheets inserted between the hot plates can be increased, which is extremely effective from the viewpoint of molding efficiency and energy saving.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state of a conventional technique for forming a plurality of laminated plates between hot plates.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pre-preg layer 2 Release resin film or release metal foil 3 Molding plate 4 Carrier plate 5 Cushion material

Claims (2)

[Claims] 1. A prepreg in which a prepreg layer obtained by impregnating and drying a thermosetting resin in a sheet-like fiber base material is sandwiched between molding plates and heated and pressed between hot plates. As a molding plate that directly contacts the layer of
A method for manufacturing a laminate, comprising using a metal plate having better heat conductivity than stainless steel, and applying a release resin to a surface of the plate facing the prepreg layer. 2. A molding plate used for manufacturing a laminate, comprising a metal plate having better heat conductivity than stainless steel and having at least one surface coated with a release resin.