JP4671345B2 - Method for producing heat-resistant rubber sheet - Google Patents

Description

The present invention is a heat-resistant rubber sheet used in applications where heat and pressure act simultaneously, for example, a vacuum press machine that is a vacuum pressurizing laminator capable of uniformly pressing a laminated molded product having an uneven surface. The present invention relates to a method for producing a heat-resistant rubber sheet that can be suitably used as a diaphragm attached to a panel.

  Laminated molded products manufactured by laminating and integrating a plurality of plate-shaped, sheet-shaped, and film-shaped molding materials under heat and pressure in a vacuum atmosphere include printed wiring boards and flexible laminated substrates. For vacuum lamination molding, a vacuum press as shown in Patent Document 1 below is used, and the material to be molded is tightly pressed by a diaphragm which is a rubber film attached to one or both of the upper and lower heating plates. Vacuum lamination molding is performed. As this diaphragm, a heat-resistant rubber sheet such as silicone rubber having high stretchability is used.

In addition, when a workpiece such as a printed circuit board is thermally cured with a hot plate of a hot press device, a cushion sheet is interposed between the hot plate of the hot press device and the workpiece to be uniformly pressurized. As this cushion sheet, it is conceivable to use a heat-resistant rubber sheet such as silicone rubber having high elasticity.
JP 2000-135739 A

  However, the above heat-resistant rubber sheet is inherently large in adhesiveness, and even if a rubber material with as low an adhesiveness as possible is selected and used, it adheres to the hot platen of a vacuum press machine, or is a laminate film or processed material of a laminated molded product. There is a problem in that it adheres to a PET film for conveyance and the like and hinders the molding operation, and it is necessary to perform a separate release treatment such as applying a release agent to the surface of the vulcanized rubber sheet.

In view of the above problems, the present invention eliminates the trouble of performing a release treatment after vulcanization molding of a rubber sheet, and has a molding efficiency and heat resistance with a mold release layer formed on the surface simultaneously with the vulcanization molding of the rubber sheet. It is an object to provide a method for producing a rubber sheet.

The present invention has the following configuration in order to solve the above problems.
(1) A method for producing a heat-resistant rubber sheet comprising a heat-resistant rubber layer, wherein a release layer made of a fluororesin is formed on at least one surface ,
Laminating a cloth layer composed of heat-resistant fibers impregnated with a fluororesin on the surface of an unvulcanized heat-resistant rubber layer , heating and pressurizing them to vulcanize , and then peeling the cloth layer the method for producing a heat-resistant rubber sheet, characterized in that the surface of the heat-resistant rubber layer by transferring the eye and fluororesin of the fabric layer forming the release layer.

According to the present invention, the release layer having the cloth eyes made of a fluororesin is integrated on one side or both sides of the heat-resistant rubber sheet by the transfer simultaneously with the molding, and there is an advantage that the release treatment is efficiently performed. Yes, reduction of molding cost can be expected.

  An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing a usage state of a heat-resistant rubber sheet (hereinafter referred to as a rubber sheet) of the present embodiment.

  The rubber sheet 1 of this embodiment is used as the film bodies 18 and 19 having stretchability, flexibility, heat resistance, and the like for tightly pressing the material to be molded in the vacuum laminating apparatus 10 that is a vacuum press machine. The vacuum laminating apparatus 10 includes an upper plate 11 and a lower plate 12 which are provided so as to be close to and away from each other, an upper plate 13 provided on the lower surface of the upper plate 11, and a lower plate provided on the upper surface of the lower plate 12. 14 and a sealed space 17 for accommodating a material to be molded is formed between frame bodies 15 and 16 sandwiching film bodies 18 and 19 provided on opposing surfaces of the upper board 13 and the lower board 14, respectively. The upper board 13 is provided with a heating device (not shown) for heating the material to be molded. Also, an air suction device (not shown) for evacuating the space between the upper board 13 and the film body 18 and the space between the lower board 14 and the film body 19 and an air compression supply device (see FIG. (Not shown), the film bodies 18 and 19 are brought into close contact with the upper board 13 and the lower board 14 by sucking air in the space, and the film bodies 18 and 19 are expanded by supplying compressed air to the space. Then, the workpiece is separated from the upper board 13 and the lower board 14 and the material to be molded is pressed between the film bodies 18 and 19. The material to be molded may be heated and pressed only on the film body 18, and the film body 19 may be omitted.

FIG. 2 is a schematic cross-sectional view showing the rubber sheet 1 of the present embodiment. The rubber sheet 1 is composed of a heat-resistant rubber layer 2 formed of silicone rubber and a heat-resistant reinforcing cloth 3 made of, for example, polyester fiber embedded in the rubber layer 2, and on one surface of the rubber sheet 1. A release layer 4 and a textured layer 5 are formed on the other side of the back surface. The heat-resistant rubber layer 2 is not limited to a single silicone rubber layer, and may be formed by laminating a plurality of grades including high-strength type silicone rubber, for example, silicone rubber layers having different hardnesses.

  FIG. 3 shows a molding process of the rubber sheet 1, wherein the surface of the unvulcanized rubber layer 2 is coated with a glass cloth 6 impregnated with a fluororesin, and a cloth 7 made of heat-resistant fibers is laid on the back surface. After these laminated sheets are pressure-heated and vulcanized and molded by a press, the glass cloth 6 and the cloth 7 are peeled off and molded.

  The release of the glass cloth 6 and the release layer 4 to which the fluororesin is transferred are formed on the surface of the rubber layer 2 by the peeling of the glass cloth 6, and the cloth is transferred to the back of the rubber layer 2 by the peeling of the cloth 7. A textured layer 5 is formed.

  FIG. 4 shows an example of a material to be molded, for example, a flexible substrate 20, in which the film bodies 18 and 19 made of the rubber sheet 1 are pressed and pressed, and a copper foil 23 is laminated on a base film 22 having flexibility. And a support film 24 that protects the copper foil 23 laminated on the surface of the circuit board 21. A film body 18 is disposed above the flexible substrate 20. Further, a PET film 25 used for a conveyance belt for a molding material is provided below the circuit board 21, and a film body 19 is disposed below the PET film 25.

  In this state, a vacuum press is performed by the vacuum laminating apparatus 10 in a state where a plurality of films and the like are laminated. At this time, in the case of the film body 18 using the rubber sheet 1 of this embodiment, the upper plate of the film body 18 Since the release layer 4 is formed in advance on the surface which is the surface facing 13, adhesion to the upper board 13 is prevented and no molding problems occur, while the surface faces the support film 24. Since the textured layer 5 is formed in advance on the back surface, adhesion to the support film 24 is prevented.

  Further, in the case of the film body 19 using the rubber sheet 1 of the present embodiment, the release layer 4 is formed in advance on the surface that is the surface facing the lower board 14 of the film body 19. While the adhesion is prevented, since the textured layer 5 is formed in advance on the back surface, which is the surface facing the PET film 25, the adhesion with the PET film 25 is prevented.

  In addition, this invention is not restricted to the said Example, In addition to not forming the textured layer of the rubber sheet 1 back surface, the heat resistant rubber layer 2 is not restricted to silicone rubber, but has high heat resistance according to the use temperature. Various rubbers such as fluorine rubber can be used. The fluororesin-impregnated glass cloth 6 can use heat-resistant fibers such as m-aramid fiber and polyimide fiber in place of the glass cloth, and the fluororesin particularly limits the type of fluororesin as long as it has releasability. A material such as a resin having excellent releasability other than fluororesin can be used.

  The fabric 7 for forming the textured layer 5 may be a woven fabric or a non-woven fabric made of heat-resistant fibers. For example, heat-resistant fibers such as polyester, aramid, polyimide, and glass can be selected. Moreover, the said heat resistant fiber can be similarly used for the reinforcement cloth embed | buried in the rubber layer 2 regardless of a kind.

Schematic explanatory drawing which shows the use condition of a heat resistant rubber sheet. The schematic sectional drawing of a heat resistant rubber sheet. The figure which shows the formation process of a heat resistant rubber sheet. The figure which shows the lamination | stacking state at the time of carrying out lamination molding of the flexible substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat resistant rubber sheet 2 Heat resistant rubber layer 3 Heat resistant reinforcement cloth 4 Release layer 5 Textured layer 6 Glass cloth 7 Cloth 10 Vacuum laminating apparatus 11 Upper plate 12 Lower plate 13 Upper plate 14 Lower plate 15, 16 Frame 17 Sealed space 18, 19 Film body 20 Flexible substrate 21 Circuit board 22 Base film 23 Copper foil 24 Support film 25 PET film

Claims (1)

A method for producing a heat-resistant rubber sheet comprising a heat-resistant rubber layer, wherein a release layer made of a fluororesin is formed on at least one surface ,
Laminating a cloth layer composed of heat-resistant fibers impregnated with a fluororesin on the surface of an unvulcanized heat-resistant rubber layer , heating and pressurizing them to vulcanize , and then peeling the cloth layer the method for producing a heat-resistant rubber sheet, characterized in that the surface of the heat-resistant rubber layer by transferring the eye and fluororesin of the fabric layer forming the release layer.

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