JPS61152436A - Manufacture of laminated sheet - Google Patents

Abstract

PURPOSE:To obtain the laminated sheet having an uniform thickness distribution by a method wherein heating and pressing for laminating and integrating prepregs are effected under a condition that the end faces of lamination are covered by liquid covering material. CONSTITUTION:A vessel 7 is put on a lower hot plate 13 and a block, consisting of laminated laminating bodies 6 of perpreg, a mirror plate 5, a cushion 3 and a carrier plate 12, is inserted into the vessel 7 to press them preliminarily with proper pressure and temperature while the liquid covering material 8 is introduced into the vessel 7 under a condition that the laminated materials are clamped properly. In case the covering material 8 is liquid in the initial condition thereof, it can be introduced by using a pump 14, however, in case the material is solid in a normal temperature, it can be thrown into the vessel 7 from the upper rim thereof and melting of the material at a forming temperature can be waited. When the forming effected by above-described method is finished, the liquid covering material 8 is discharged and, thereafter, the laminated sheet is taken out of the vessel 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention is directed to the field of manufacturing technology for laminates made of thermosetting resins.

[Background Art] Conventionally, thermosetting resin laminates are produced by preparing a so-called prepreg, which is a base material impregnated with a thermosetting resin, and laminating a plurality of prepregs, and if necessary, coating one or both sides with metal foil. It was manufactured by stacking layers (usually made of copper foil), sandwiching them between mirrored plates, and pressing them together under heat. This heat-pressing process often uses a multi-stage press equipped with a plurality of hot platens to produce a plurality of laminates at once.

By the way, when the prepreg laminate is heated and pressurized by the hot platen, the collapsed material melted by the heating flows out from the end face of the laminate exposed to the atmosphere, and as a result, the end of the laminate as a product is damaged. The disadvantage was that the resin content of the plate was reduced, and the plate thickness became thinner or inconsistent. Furthermore, since the temperature distribution between the so-called top plate and the carrier plate is not uniform, there is a problem that the plate thickness becomes uneven due to the difference in stacking position.

[Object of the Invention] The present invention was made with the object of improving the non-uniformity of the thickness of a laminate that occurs in the laminate manufacturing process, particularly in the pressing process.

[Disclosure of the Invention] This invention is a method for manufacturing a laminate made of a thermosetting resin, in which prepregs are laminated and heated and pressurized to integrate them while the end surfaces of the laminated prepregs are covered with a liquid coating material. The present invention provides a method for manufacturing a laminate, which is characterized by performing the following steps.

The present invention will be explained below with reference to drawings shown as examples. FIG. 1 is a schematic diagram for explaining the pressing process of a laminate according to the present invention. In this figure, 1.13 is a heating plate, 2 is a top plate, 3.11 is a cushion, 4.6.10 is a stainless steel mirror plate, 5.9 is a prepreg, 7 is a heat-resistant container,
8 is a sealing liquid, 12 is a carrier plate, and 14 is a pump.

In the above, the heating plate 1.13, the cushion 31.11,
The mirror plate 4.6.10, the carrier plate 13, etc. are not much different from those used in the manufacturing method of ordinary laminates. A feature of this invention is that the end faces of the prepreg laminate are coated with a liquid coating material 8, and at least a part of the heating and pressing is performed. In the case of FIG. 1, the process is carried out in a liquid coating material 8 filled in a container 7. The end face, which is normally exposed to the atmosphere, is coated with a liquid coating material to eliminate non-uniformity in temperature distribution and to prevent resin from flowing out from the end face.

The liquid coating material for end face coating used in this case is:
Although there is no particular limitation, it is sufficient as long as it is liquid at least near the pressing temperature (so-called molding temperature) and is inert to the resin constituting the laminate. Therefore, even if the material is solid before the temperature is raised, it only needs to melt and become liquid at the molding temperature. Of course, it may be in a liquid state before use. As the liquid coating material, for example, polyethylene resin is used. Other inert heat media may also be used.

The liquid coating material used also varies depending on the resin used for the laminate. For example, if it is an epoxy resin, the molding temperature is 170 to 175°C, so any material that becomes liquid at around that temperature can be used.

When actually forming, a container 7 is placed on the lower heating plate 13, and a block in which the prepreg laminate 6, mirror plate 5, cushion 3, and carrier plate 12 are stacked is placed in the container 7, and Preliminarily pressed at an appropriate pressure and temperature, and in an appropriately tightened state, the liquid coating material 8 is poured into the container 7.
to be introduced into the Note that it is important to feed the liquid coating material 8 after the preliminary molding to prevent the liquid coating material 8 from entering the glabella of the prepreg laminate 6. If the liquid coating material 8 is in a liquid state from the beginning, it can be fed using the pump 14, but if it is solid at room temperature, it can be fed from the upper edge of the container 7 and then heated at the molding temperature. You can also wait for it to melt.

When the molding by the conventional method is completed, the liquid coating material 8 is discharged,
If necessary, collect it and take out the laminate. Note that the liquid coating material 8 may be freely used for cooling the laminate after the molding is completed. Alternatively, the refrigerant can be injected after the liquid coating material 8 is discharged.

The liquid dressing 8 is preferably injected as far as possible to the level of the upper end of the block, ie to the extent that it is completely immersed in the liquid dressing 8. Further, since the volume of the block is reduced during the molding process and the level of the upper end is lowered, it is preferable that the upper heating plate 1 and the like be placed in a size that can fit into the container 7.

In addition to the method described above, in order to make the heating temperature uniform during the molding process, surface heaters may be placed on both sides of each mirror plate for molding. FIG. 2 is a schematic diagram showing such an example. In this figure, 15.26
is a heating plate, 16 is a top plate, 25 is a carrier plate, 17.24 is a cushion, 18.23 is a surface heater,
19.22 is a mirror plate, and 20.21 is a prepreg laminate. Although the surface heaters 18 and 23 may be made of any material, they are preferably made of a material that can withstand pressure and heating, have high rigidity, and have a large flatness. Ceramic heaters are usually used, and electric heating is recommended.

In addition, as for the techniques necessary for manufacturing a laminate other than those described above, it is sufficient to employ conventional methods.

[Effects of the Invention] The present invention is a method for manufacturing a laminate made of thermosetting resin, in which prepregs are laminated and heated and pressurized to integrate them while the end surfaces of the stacked prepregs are covered with a liquid coating material. Since this method is characterized by the fact that a laminate plate having a uniform thickness distribution can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing another embodiment. 1.13 is the heating plate 2, the top plate 3 is the cushion 4, 6.10 is the stainless steel mirror plate 5.9, the prepreg 7 is the heat-resistant container 8, and the sealing liquid 12 is the carrier plate. 14 is a pump 15. 26 is a heating plate 16 is a top plate 25 is a carrier plate 17. 24 is a cushion 18. 23 is a surface heater 19. 22 is a mirror plate 20. 21 is a prepreg laminate Patent applicant Agent Matsushita Electric Works Co., Ltd. Patent attorney Toshimaru Takemoto (and 2 others) Figure 1 Figure 2

Claims (2)

[Claims] (1) A method for manufacturing a laminate made of thermosetting resin, which includes a process in which prepregs are laminated and heated and pressurized to integrate them while the stacked end surfaces of the prepregs are coated with a liquid coating material. A method for producing laminates characterized by: (2) The manufacturing method according to claim 1, characterized in that the process of coating the stacked end faces of the prepreg with a liquid coating material and heating and pressurizing them is carried out in a container filled with the liquid coating material.