JPH11170382A - Manufacture of laminated sheet and forming plate thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the repeated use of releasable resin films and the manufacturing of laminated sheets possible by a method wherein each forming plate is made of metallic material having a better thermal conductivity than that of a stainless steel and is used under the condition that a releasable resin film is thermally fused to its surface opposing to a prepreg layer. SOLUTION: A forming plate 3 is made of an aluminum or copper material having a better thermal conductivity than that of a stainless steel or an alloy material including them. A releasable resin film, which covers the surface of the forming plate 3 is an fluororesin film or the like. A laminated sheet is manufactured by forming under heat and pressure by pinching a prepreg layer 1 between forming plates 3. Accordingly, in the forming plate 3, the releasable resin film 2 is integrated with the forming plate 3 through its surface opposite to the prepreg layer 1. The forming plate 3, on both the sides of which the releasable resin films 3 are integratedly formed, is more profitable. As a result, the heat conduction at the forming of the laminated sheet becomes quicker, resulting in realizing a uniform heat distribution in the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a laminate in which a prepreg layer which has been impregnated with a thermosetting resin into a sheet-like fiber base and dried to form a B-stage is heated and pressed between hot plates. The laminate is formed by integrating a metal foil such as a copper foil on one or both sides as necessary at the time of heat and pressure molding. This is a method suitable for manufacturing a laminate in which foils are integrated. The present invention also relates to a molding plate used for manufacturing such a laminated board.

[0002]

2. Description of the Related Art A laminated board is manufactured by impregnating a sheet-like fiber base material with a thermosetting resin and drying to prepare a B-staged prepreg, and forming the prepreg layer by heating and pressing between hot plates. You. FIG. 1 shows a state in which a plurality of laminated plates are formed between hot plates. Release resin films 2 are arranged on both surfaces of a prepreg layer 1 which is stacked by the number required for manufacturing one laminated board, and sandwiched between a pair of molding plates 3. 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 forming plate is for imparting smoothness to the surface of the laminated plate, and is usually made of a stainless material having high hardness without rust. In addition, metal foil such as copper foil is integrated into one or both sides of the laminate as necessary during hot press molding, but metal foil is not integrated on both sides or metal foil is integrated only on one side In the manufacture of laminated boards,
As shown in FIG. 1, a release resin film is disposed on the prepreg layer, so that sticking between the formed laminate and the forming plate does not occur.

[0003]

A plate made of stainless steel has a low thermal conductivity and a large temperature gradient in the heat transfer direction. When a laminate is formed using such a forming plate, thermal distortion during heating and cooling remains in the laminate, and the laminate is easily warped. In addition, since the mold release resin film adheres to the formed laminate, a new mold release resin film is required for each molding, and the mold release resin film is peeled off from the laminate after molding and discarded. The problem to be solved by the present invention is to manufacture a laminate having a small warpage, which enables repeated use of a release resin film.

[0004]

In order to solve the above-mentioned problems, in the method of manufacturing a laminate according to the present invention, a forming plate made of a metal material having better heat conductivity than stainless steel is used. And, for the molding plate used,
A releasable resin film is integrated on the surface facing the prepreg layer by heat fusion.

[0005] When the heat conduction of the forming plate is improved, the temperature difference in the thickness direction of the prepreg and the laminated plate formed from the prepreg during heating and cooling is reduced, and no thermal distortion remains in the laminated plate. Warpage and deformation can be kept small. The releasable resin film integrated with the surface of the molding plate by heat fusion does not peel off from the molding plate, so that it can be used repeatedly. In order to cover the surface of the molding plate with the release resin, a means of applying the resin to the surface of the molding plate is conceivable, but it is difficult to make the coating uneven and the thickness to be uniform. Therefore, if the coating of the surface of the molding plate with the release resin is realized by heat fusion of the release resin film to the surface of the molding plate as in the present invention, the thickness can be made uniform and the molding plate can be made uniform. Can sufficiently fulfill the function of imparting smoothness to the surface of the laminate.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A forming plate used in the method according to the present invention is made of an aluminum or copper material having better heat conductivity than stainless steel, or an alloy material containing these materials. The release resin film covering the surface of the molding plate is a fluororesin film or the like. The molding plate made of a metal material having good heat conductivity has low hardness. Therefore,
When such a forming plate is used in direct contact with the metal foil when forming a metal foil-clad laminate, the friction between the two contact surfaces due to the difference in thermal expansion between the metal foil and the forming plate is used. In addition, the abrasion of the molding plate becomes remarkable.
However, if the release resin film is integrated with the molding plate by thermal fusion, there is no such concern.

The production of a laminate is carried out by sandwiching a prepreg layer between molding plates by heating and pressing. Therefore, the mold release plate may be formed by integrating the release resin film on the surface facing the prepreg layer. However, FIG.
As shown in (1), when a plurality of laminated plates are formed between hot plates, one forming plate located in the middle becomes a forming plate for forming laminated plates located on both sides thereof. From such a viewpoint, it is convenient for the mold plate to have a release resin film integrated on both surfaces thereof. However, it is not always necessary that the release resin films are integrated on both sides, but two mold plates with the release resin film integrated only on one side are integrated with the release resin film. They may be used in an overlapping manner, with the uncoated surface facing inward.

In order to manufacture a laminated board, first, a thermosetting resin is impregnated into a sheet-like fiber base and dried to manufacture a B-stage prepreg. Sheet-like fiber base material is paper,
It is a woven fabric, a nonwoven fabric, or a mat made of natural fibers, organic synthetic fibers, inorganic fibers, and the like, and is not particularly limited. In addition, thermosetting resin, phenolic resin, epoxy resin,
It is a polyester resin or the like and is not limited. Further, at the time of heat-press molding of the prepreg layer, a metal foil such as a copper foil can be integrated on one side or both sides as necessary, but the metal foil is integrated on only one side or the metal foil on both sides. It is effective to use the above-mentioned molding plate in the case where is not integrated.

[0009]

EXAMPLE A 55% aluminum-zinc alloy steel sheet (thickness: 1.0 mm, coefficient of thermal expansion: 0.00034 BTU / sec) was integrated with a fluororesin film (thickness: 12 μm) on both sides by heat welding. A plate was prepared. A prepreg layer having a resin content of 35% by weight obtained by impregnating and drying an epoxy resin varnish in a glass woven fabric is sandwiched between the above-mentioned molding plates, and a plurality of sets of the prepregs are put between hot plates as shown in FIG. And pressure 130
A laminate (dimensions: 1000 × 1000 × 0.4 mm) was manufactured by heating and pressing at a temperature of 165 ° C. for 180 minutes at a temperature of 165 kg / cm 2. Even after this molding plate was repeatedly used 300 times in the production of a laminated plate, the release properties of the laminated plate and the molding plate were good and no change was observed from the beginning, and the coating state of the fluororesin film on the molding plate There was no problem with the appearance of the formed laminate. And this molding plate can be further used.

Conventional example SUS630 (thickness: 1.0 mm, coefficient of thermal expansion: 0.0014)
(BTU / sec) was used as a molding plate, and a laminate was produced in the same manner as in the example.

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.

[0012]

[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 manufactured in the same manner, the forming plate could be used repeatedly as in the example. On the other hand, when a molding plate (55% aluminum / zinc alloy steel plate) not covered with the fluororesin film is used, the wear of the surface of the molding plate used to face the metal foil is repeated 40 times. Became noticeable.

[0014]

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. In addition, since a molding plate in which the release resin film is integrated by heat welding on the surface is used, the release resin film can be used repeatedly without preparing a new release resin film for each molding cycle.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a plurality of laminated plates are formed between hot plates.

[Explanation of symbols]

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

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 08 B29L 9:00

Claims (2)

[Claims] 1. A required number of B-staged prepregs obtained by impregnating and drying a thermosetting resin into a sheet-like fiber base material are stacked on each other, and the prepreg layer is sandwiched between forming plates and heated and pressed between hot plates. In the production of a laminate, a molding plate made of a metal material having better heat conductivity than stainless steel and having a release resin film integrated with a surface facing the prepreg layer by heat fusion is used as the molding plate. A method for producing a laminate, characterized in that: 2. A molding plate for forming a laminate, comprising a metal material having better heat conductivity than stainless steel, and a releasable resin film integrated on at least one surface by heat fusion.