JPH0617025B2 - Multilayer board manufacturing method - Google Patents

Description

Description: [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for producing a multilayer board in which a substrate layer and a surface layer are firmly integrated and which has an excellent appearance.

(Prior Art) Conventionally, as a method of integrating a substrate layer and a surface layer of a multi-layer board, a method of pressure bonding with an adhesive, a method of forming a substrate layer and adhering to a surface-treated film, etc. There are used a method of coating and printing an agent layer and then integrating them, or a method of surface-treating the substrate layer side to form an adhesive layer and then forming a film and the like.

(Problems to be Solved by the Invention) However, in any of the above methods, at least two steps of molding and integration are required in order to integrate them after molding the substrate layer and the surface layer, respectively. It has the drawback of being difficult to manufacture. Further, the molding material, which is a raw material for the multilayer board, is mixed with an internal mold release agent so as not to adhere to the mold during the production thereof. Further, since the internal mold release agent is leached onto the surface of the multilayer board during molding, the adhesiveness of the multilayer board is significantly reduced. To improve this adhesion,
Before the bonding, it was necessary to add other steps such as treating the surface and providing an adhesive layer in advance.

On the other hand, the appearance of the multilayer board is damaged due to the pressure bonding process between the substrate layer and the surface layer, and in order to improve the appearance of this surface layer, the surface layer should be formed before the substrate layer and the surface layer are integrated. There is a drawback that problems such as an increase in the number of steps and an increase in cost due to material cost occur because the method of improving treatment or adding and blending an improving agent for the surface layer and in the molding material is adopted.

The present invention has been made in order to solve the above-mentioned drawbacks, has excellent adhesiveness between the substrate layer and the surface layer, is free from blistering and peeling, and can be produced in one step, and is free from warpage, fogging, and a good surface appearance. It is intended to provide a method for manufacturing a multilayer board.

[Structure of the Invention] (Means for Solving the Problems) As a result of earnest research aimed at achieving the above-mentioned object, the present inventors have provided unevenness on the contact surface between two resin layers of a substrate layer and a surface layer, The inventors have found that the above object can be achieved by integrally molding two resin layers in one step of non-demolding continuous molding, and completed the present invention. That is, the present invention, in the production of a multilayer plate consisting of a thermosetting resin substrate layer and a thermosetting resin surface layer, to form a thermosetting resin molding material using a roughened mold, A molding layer having irregularities on one side is obtained in the mold, and subsequently, another thermosetting resin molding material is charged on the irregular surface of the molding layer to form a surface layer, In the method for producing a multilayer board, the surface layer is brought into close contact with and integrated with the molded body layer corresponding to the substrate layer, and then the mold is released. Further, it is a method for producing a multilayer board, in which the surface layer is formed by using a roughened mold to form a satin finish on the surface side of the multilayer board.

The mold used in the present invention is not particularly limited in its structure, but is usually composed of an upper mold, a frame, and a lower mold, and an aluminum alloy mold is also used as the mold material in the case of small-scale production. The surface of the upper mold which is in contact with the molding material is roughened so that a molding layer of thermosetting resin having irregularities on one surface can be obtained. As a method for roughening the surface of the mold, known methods such as sand blasting, acid treatment, and forming can be used. However, depending on the properties of the two resin layers to be adhered and integrated, the purpose, etc. The roughness is determined, and a more suitable method is selected for the roughening. Also, when the surface of the multilayer board is made to have a matte surface, the mold is roughened and used by the same method as described above. Furthermore, a multi-layer board having an arbitrary thickness can be obtained by appropriately selecting the thickness of the frame of the mold. It is not necessary to roughen the mold unless the surface of the multi-layer plate has a matte surface or a desired processing. In this case, a multi-layer plate having a normal light selection can be obtained.

A release agent is used to release the upper mold from the roughened mold. This release agent has a great influence on the adhesion between the molded body layer and the surface layer integrated thereon. That is,
When a mold release agent is attached to the surface of the molded body layer, a sufficient anchor effect between the molded body layer and the surface layer cannot be obtained, and when the molded body layer and the surface layer are integrated, adhesive defects such as blistering and peeling appear. . Further, if the release agent adheres to the surface of the surface layer, it will adversely affect the appearance such as flow marks and cloudiness. Therefore, it does not adhere to the surface as a release agent like silicone-based agents,
Those having a low adhesive property such as a fluorine type are preferable.

A thermosetting resin molding material is used for molding the molded body layer and the surface layer constituting the multilayer board. As the thermosetting resin, for example, phenol resin, unsaturated polyester resin, epoxy resin, polyimide resin, etc. are molded. Materials may be used, and these may be used alone or as a mixed system of two or more kinds. It is desirable that the thermosetting resin molding material is different in the material for manufacturing the first molded body layer and the material for forming the surface layer.
For example, when an unsaturated polyester resin molding material is used as the molding layer, good results are obtained by using an epoxy resin molding material for the surface layer.

The surface layer is formed by forming a molded body layer and then forming a spacer on the molded body layer, and the thickness of the spacer is arbitrary depending on the thickness of the surface layer in consideration of the characteristics required by the product. Can be controlled.

(Function) Since the thermosetting resin molded body layer having irregularities on one side is obtained using the roughened mold and the surface layer is formed on the irregularized surface, the molded body layer and the surface layer are different from each other. Fully adheres and integrates due to the anchor effect. Further, in this case, if a fluorine-based release agent having a low adhesive property is used, further adverse effects on the surface layer such as blistering, peeling and poor appearance are eliminated. If a matte surface is desired as the surface of the multilayer board, a roughened mold is used to
In the process, a multilayer board having a desired surface condition is obtained.

(Example) Next, the Example of this invention is described using drawing.

Example As shown in FIG. 1, a frame 2 having a thickness of 5 mm is attached to the lower mold 3, and the lower mold is treated with a release agent. The unsaturated polyester resin molding material 4a is loaded into the frame 2 of the lower mold 3, roughened by sandblasting, and then the upper mold 1 made of an aluminum alloy which has been treated with a fluorine-based mold release agent is placed thereon. As shown in the figure, heat and pressure molding were carried out to obtain an unsaturated polyester resin molded body layer 4 having irregularities on one side in the mold. Next, a spacer 5 having a thickness of 1 mm was attached on the frame 2 of the lower mold 3 as shown in FIG. Further, an epoxy resin molding material 6a is loaded on the molding layer 4 in the frame of the spacer 5, and an upper mold 7 prepared separately from the upper mold 1 and having a matte finish on one side is used (fourth).
Figure). Then, as shown in FIG. 5, the upper mold 7 was placed on the spacer 5, heated and pressure-molded, and the surface layer 6 was adhered and integrated on the molded body layer 4 to manufacture a multilayer board. The released multilayer plate was further heated to completely cure the surface layer. This multilayer board had a warp, two layers having pinholes adhered and integrated, and had a beautiful appearance.

Comparative Example In the example, the roughened upper mold 1 and the satin finished upper mold 7 were used.
A multi-layer board was manufactured in the same manner as in Example except that the upper mold which was not roughened was used in place of, and the upper mold 1 was not treated with a fluorine-based releasing agent. This multilayer board had blisters and was cloudy and had a poor appearance.

[Effects of the Invention] As is apparent from the above description, according to the manufacturing method of the present invention, the molded body layer and the surface layer are adhered and integrated by the anchor effect due to the unevenness formed on the molded body layer,
It was possible to obtain a multilayer board having an excellent appearance, which was free from peeling, warped in one step by pressing, and was free from fogging.

[Brief description of drawings]

FIG. 1 to FIG. 5 are process drawings schematically showing each step in a method for manufacturing a multilayer board of the present invention in a mold section. 1, 7 ... upper mold, 2 ... frame, 3 ... lower mold, 4a ... unsaturated polyester resin molding material, 4 ... unsaturated polyester resin molding layer, 5 ... spacer, 6b ... epoxy resin Molding material, 6 ... Surface layer.

Claims (2)

[Claims] 1. A method for producing a multilayer board comprising a thermosetting resin substrate layer and a thermosetting resin surface layer, the thermosetting resin molding material is molded using a roughened mold, A molding layer having irregularities on one surface is obtained in the mold, and subsequently, another thermosetting resin molding material is charged on the irregular surface of the molding layer to form a surface layer, A method for producing a multi-layer board, comprising: closely adhering a surface layer to a molded body layer corresponding to a substrate layer, and then removing from the mold. 2. The method for producing a multilayer board according to claim 1, wherein the surface layer is formed by using a mold having a roughened surface to form a satin finish on the surface side of the multilayer board.