JP2007118542A - Buffering rubber sheet having heat resistance and mold releasability - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a buffering rubber sheet having heat resistance and mold releasability, excellent in the adhesiveness of a rubber sheet and a mold releasable resin film and capable of being enhanced in durability. <P>SOLUTION: The buffering rubber sheet 16 having heat resistance and mold releasability is constituted by integrating glass cloth 18 with one side of the rubber sheet 17 comprising a fluororubber or a silicone rubber and bonding a mold releasable fluoroplastic resin film 20 with a melting point of 300-350°C having an adhesive layer 19 to the glass cloth 18 by the adhesive layer 19. The rubber sheet 17 and the glass cloth 18 are integrated by laminating the glass cloth 18 to one side of an unvulcanized rubber sheet 17 containing a vulcanizing agent to heat and vulcanize the unvulcanized rubber sheet 17. The fluoroplastic resin film 20 preferably comprises a polytetrafluoroethylene resin or a tetrafluoroethylene/perfluoroalkoxyethylene copolymer resin. Further, as the adhesive for forming the adhesive layer 19, a silicone adhesive is preferable. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used when connecting a panel for a screen and a circuit, a device for controlling the panel, etc. in a module manufacturing process of a flat display panel (FPD), particularly a liquid crystal display (LCD) of 10 inches or more. The present invention relates to a shock-absorbing rubber sheet having heat resistance and releasability.

  A connecting jig used to connect a screen panel and a control circuit in the FPD is a metal plate having a width of 1 to 2 mm and a length of the FPD panel. The length of the FPD panel is about 1000 mm for a panel having a 40-inch screen. Then, using the connecting jig, an adhesive called anisotropic conductive film (ACF, Anisotropic Conductive Film), that is, an epoxy resin as a matrix and an adhesive in which metal powder as conductive particles is dispersed, Adhesive film (TCP) is adhered to a panel and a control circuit. At that time, in order to cure the ACF, the connecting jig is heated to 300 ° C. or higher which exceeds the ACF curing temperature (about 200 ° C.). When TCP is pressure-bonded to the panel and control circuit with a connection jig heated to a high temperature, the TCP tends to be distorted, so an elastic cushioning rubber sheet is placed between the connection jig and TCP. To avoid it.

Further, when the TCP is connected to the panel, the control circuit, and the like with the ACF using a connection jig, the buffer rubber sheet may be bonded to the adhesive protruding around the lead wire. In order to prevent this, a release film such as polytetrafluoroethylene resin (PTFE) is interposed between the connecting jig and the buffer rubber sheet. In that case, the cushioning rubber sheet and the release film are required to be integrated from the viewpoint of simplification of setting and superior heat transfer. In order to meet such a demand, a composite sheet in which a heat-resistant resin film such as a fluororesin film is bonded to a silicone rubber sheet with a silicone adhesive has been proposed (see, for example, Patent Document 1). Furthermore, a release sheet for thermocompression bonding is known in which surface activation treatment is performed on one surface of a glass fiber reinforced fluororesin sheet, and vulcanized silicone rubber is laminated and integrated on that surface (for example, Patent Document 2). See).
JP 2001-18330 A (pages 2 and 5) JP 2004-168025 A (page 2, page 5 and page 6)

  However, in the composite sheet described in Patent Document 1, when exposed to a high temperature during use, the difference between the thermal expansion coefficients of the silicone rubber sheet and the fluororesin film is large. However, there is a problem that a part that floats from the silicone rubber sheet is generated. Accordingly, such a composite sheet lacks durability. Further, in the thermocompression-bonding release sheet described in Patent Document 2, since the glass fibers for reinforcing the fluororesin sheet are dispersed in the fluororesin and hardly exist on the surface, the fluororesin sheet substantially There was a problem similar to that of the composite sheet of Patent Document 1. The surface of the fluororesin sheet has been subjected to a surface activation treatment, but has not yet been able to solve the problem of peeling at high temperatures.

  Accordingly, an object of the present invention is to provide a buffer rubber sheet having excellent heat resistance and releasability that can improve durability and excellent adhesion between the rubber sheet and the release resin film. is there.

  In order to achieve the above object, the heat-resistant and releasable cushioning rubber sheet according to the first aspect of the present invention has a glass cloth integrated on at least one surface of a rubber sheet made of fluororubber or silicone rubber. And a release fluororesin film having a melting point of 300 to 350 ° C. having an adhesive layer is bonded to the glass cloth by the adhesive layer.

  The buffer rubber sheet having heat resistance and releasability according to the invention of claim 2 is the invention according to claim 1, wherein the integration of the rubber sheet and the glass cloth is not added with a vulcanizing agent. The vulcanized rubber sheet is heated and vulcanized in a state where a glass cloth is bonded to at least one surface of the vulcanized rubber sheet.

  The buffer rubber sheet having heat resistance and releasability according to claim 3 is the invention according to claim 1 or 2, wherein the release fluororesin film is a polytetrafluoroethylene resin. Alternatively, it is a film formed of a tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin.

  The buffer rubber sheet having heat resistance and releasability according to claim 4 is the invention according to any one of claims 1 to 3, wherein the adhesive forming the adhesive layer is a silicone-based It is characterized by being an adhesive.

According to the present invention, the following effects can be exhibited.
The rubber sheet for cushioning having heat resistance and releasability according to claim 1 has a melting point having a glass cloth integrated on at least one surface of a rubber sheet made of fluoro rubber or silicone rubber and having an adhesive layer. A release fluororesin film at 300 to 350 ° C. is bonded to the glass cloth by the adhesive layer. Since the rubber sheet is formed of fluoro rubber or silicone rubber, it has heat resistance, and since it is integrated with the glass cloth, thermal expansion is suppressed. Moreover, since the adhesive layer of the fluororesin film for release is bonded to a glass cloth having a small thermal expansion instead of a rubber sheet having a large thermal expansion, good adhesiveness is exhibited. Even when the cushioning rubber sheet is exposed to a high temperature after bonding, the occurrence of a difference in thermal expansion is suppressed by the glass cloth interposed between the rubber sheet and the fluororesin film, and the adhesive force is maintained. Accordingly, the adhesion between the rubber sheet and the release resin film is excellent, and the durability can be improved.

  In the buffer rubber sheet having heat resistance and releasability according to claim 2, the rubber sheet and the glass cloth are integrated on at least one surface of the unvulcanized rubber sheet containing the vulcanizing agent. It is performed by heating and vulcanizing in a state of bonding. Therefore, in addition to the effect of the invention according to the first aspect, the rubber sheet and the glass cloth can be integrated easily and reliably.

  In the rubber sheet for cushioning having heat resistance and releasability according to claim 3, the fluororesin film for release is made of polytetrafluoroethylene resin or tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin. It is a formed film. For this reason, in addition to the effect of the invention which concerns on Claim 1 or Claim 2, heat resistance can fully be exhibited.

  In the rubber sheet for cushioning having heat resistance and releasability according to the invention described in claim 4, the adhesive forming the adhesive layer is a silicone adhesive. Therefore, in addition to the effect of the invention according to any one of claims 1 to 3, the affinity for the glass cloth can be increased and the adhesive force can be improved.

In the following, embodiments that are considered to be the best of the present invention will be described in detail.
The panel for the screen in the FPD and the printed circuit board having the control circuit and the like are electrically connected by bonding the conductive thin film (TCP) with the anisotropic conductive film (ACF) as an adhesive. ing. The conductive thin film is a film obtained by blending a conductive powder (metal powder or the like) with a silicone material (silicone rubber) or a non-silicone material. The thickness is about 30 to 70 μm, and the volume resistivity is about 5 × 10 ^{−4 to} 5 × 10 ⁻¹ Ω · cm. The anisotropic conductive film is an adhesive in which, for example, an epoxy resin is used as a matrix and conductive powder is dispersed. The curing temperature of the epoxy resin is about 200 ° C. As the conductive powder, nickel, silver, copper, graphite (graphite), carbon black or the like is used.

  As shown in FIG. 2 (a), using the connecting jig 11, one side of the conductive thin film 12 is bonded to the screen panel 14 with the anisotropic conductive film 13, and the conductive thin film 12 The panel 14 and the printed circuit board 15 are electrically connected via the conductive thin film 12 by bonding the other side part to the printed circuit board 15. The connection jig 11 is made of metal, has a width of 1 to 2 mm, and a length of the FPD panel 14, and one side edge in the length direction is formed thin like a knife. The connecting jig 11 is heated to a high temperature exceeding its curing temperature, for example, 300 ° C. or higher in order to cure the anisotropic conductive film 13. In that case, the shock-absorbing rubber sheet is bonded to the connection jig 11 and the panel 14 or the printed circuit board 15 so that the entire conductive thin film 12 is uniformly bonded to the panel 14 or the printed circuit board 15 by the connection jig 11. It is inserted between. Here, the buffering property means that when the conductive thin film 12 is bonded to the panel 14 or the printed circuit board 15 with the connecting jig 11, a part of the conductive thin film 12 is distorted (warped) and floats, This is a property that assists this so that there is no part that is not sufficiently transmitted.

  As shown in FIGS. 1A and 1B, the rubber sheet 16 for buffering is a release fluororesin film having a glass cloth 18 integrated on one side of a rubber sheet 17 and an adhesive layer 19. 20 (hereinafter also simply referred to as a fluororesin film) is bonded to the glass cloth 18 by the adhesive layer 19. The buffering property of the buffering rubber sheet 16 is manifested mainly by the elasticity of the rubber sheet 17. FIG. 1 schematically shows the buffer rubber sheet 16 and does not strictly represent the thickness or the like. As the rubber sheet 17, fluorine rubber or silicone rubber is used from the viewpoint of heat resistance.

  As the fluororubber, vinylidene fluoride-trifluoroethylene copolymer rubber, vinylidene fluoride-hexafluoropropylene copolymer rubber, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer rubber, etc. are used. . Silicone rubber is a polymer having a siloxane bond (Si—O—Si) as a skeleton, and various types can be obtained by changing the skeleton structure, the degree of polymerization, or the organic group of the side chain. Such silicone rubber has excellent heat resistance, weather resistance, electrical characteristics, and the like. As the silicone rubber, for example, millable type silicone rubber is used. This millable silicone rubber is mainly composed of a linear polymer having a polymerization degree of 3000 to 10000, and contains a silica-based reinforcing filler, a wetting agent, and various additives. A vulcanizing agent is added at the time of use. This is a type of rubber that cures by heating. Like ordinary organic rubber, it is called a millable type because it is processed through plasticization, addition of a vulcanizing agent, and roll work using a roll mill.

  The thickness of the rubber sheet 17 is appropriately set according to the purpose, but is preferably 150 to 500 μm from the viewpoint of buffering properties and heat transfer properties. When this thickness is less than 150 μm, the buffering property is not sufficiently exhibited, and the conductive thin film 12 may partially adhere to the panel 14 or the printed board 15. On the other hand, when the thickness exceeds 500 μm, the rubber sheet 17 becomes too thick and the heat conductivity is deteriorated, and the heat is not sufficiently transferred from the connecting jig 11 to the anisotropic conductive film 13. In some cases, poor adhesion with the panel 14 or the printed circuit board 15 may be caused.

  The glass cloth 18 is a woven fabric in which a glass yarn obtained by twisting a glass fiber in the same manner as a synthetic fiber is processed into a woven fabric using a loom. As the glass fiber, a long fiber is usually used. This glass cloth 18 is excellent in heat resistance and has a very small coefficient of thermal expansion. By integrating the glass cloth 18 on one side of the rubber sheet 17, when the rubber sheet 17 is exposed to a high temperature, thermal expansion hardly occurs on that side.

  The thickness of the glass cloth 18 is preferably 10 to 100 μm and more preferably 30 to 50 μm from the viewpoint that the thinner the glass cloth 18, the better the buffering properties during use. When the thickness is less than 10 μm, the reinforcing property of the rubber sheet 17 is not preferable. On the other hand, when the thickness exceeds 100 μm, the hard glass cloth 18 becomes too thick, and the cushioning property when the cushioning rubber sheet 16 is used tends to deteriorate.

  The rubber sheet 17 and the glass cloth 18 are integrated by heating and vulcanizing with the glass cloth 18 bonded to one side of an unvulcanized rubber sheet 17 containing a vulcanizing agent. At this time, the glass cloth 18 is partially or wholly embedded in the rubber sheet 17 so that the anchor effect is exhibited and bonded. Specifically, a vulcanizing agent is blended with unvulcanized rubber, processed into an unvulcanized sheet by calendaring or the like, and a glass cloth 18 is bonded thereto, and heated and vulcanized in that state. . As the vulcanizing agent, organic peroxides such as 2,5-dimethyl-2,5-ditertiary butyl peroxyhexane and p-methylbenzoyl peroxide are used. The heating temperature for vulcanization is preferably 160 to 180 ° C. The heating time is preferably 5 to 60 minutes. In vulcanization, it is preferable to heat and pressurize with a heating press.

  Next, as the release fluororesin film 20, a fluororesin film having a melting point of 300 to 350 ° C. is used from the viewpoint of heat resistance. When the melting point of the fluororesin is less than 300 ° C., the heat resistance is insufficient and the fluororesin film 20 is deformed at a high temperature, which is inappropriate. On the other hand, when the melting point of the fluororesin exceeds 350 ° C., the fluororesin becomes special, which makes it difficult to manufacture or obtain. Specific examples of the fluororesin include polytetrafluoroethylene resin (polytetrafluoroethylene resin, PTFE, melting point 327 ° C.) or tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). Polymerized resin, PFA, melting point 302 to 310 ° C.) and the like are preferably used.

  The thickness of the fluororesin film 20 is preferably thin from the viewpoint of heat transfer, and is preferably 10 to 100 μm, and more preferably 10 to 50 μm. When the thickness of the fluororesin film 20 is less than 10 μm, the shape retainability is deteriorated and the handleability is also lowered. On the other hand, when it exceeds 100 μm, the heat transfer property is deteriorated and the function of the buffer rubber sheet 16 is lowered.

The adhesive layer 19 provided on the fluororesin film 20 is not limited, but is preferably formed with a silicone-based adhesive. The silicone-based adhesive is made of silicone composed of siloxane bond (Si—O—Si), has an affinity for glass cloth 18 mainly composed of silicic acid (SiO ₂ ), and is excellent in adhesiveness. It is. Silicone rubber is used as the silicone-based adhesive, and there are a thermal crosslinking type that is crosslinked by heating and a crosslinking agent (curing agent) or a room temperature crosslinking type (RTV) that is crosslinked by moisture in the air, both of which are used. In the thermal crosslinking type, a crosslinked structure is formed by blending a silicone rubber with a filler and an organic peroxide and heating. On the other hand, the room temperature curable type has a reactive functional group in the silicone molecule and reacts with a crosslinking agent at room temperature to form a crosslinked structure. Examples of the reactive functional group include a hydroxyl group, and examples of the crosslinking agent include a low molecular silicon compound having an acetoxy group, an alkoxy group, and the like. In the present invention, the silicone adhesive represents a concept including a silicone adhesive in addition to the silicone adhesive. The silicone-based pressure-sensitive adhesive is, for example, a combination of silicone rubber and a low polymerization degree silicone resin. Usually, a peroxide such as benzoyl peroxide is added for crosslinking to increase the cohesive force.

  Now, the operation of this embodiment will be described. First, the glass cloth 18 is bonded to the rubber sheet 17 by heating and vulcanizing the glass cloth 18 in a state where the glass cloth 18 is bonded to one side of the unvulcanized rubber sheet 17 containing the vulcanizing agent. 18 is integrated. On the other hand, the adhesive layer 19 is formed on the fluororesin film 20 by coating the surface of the fluororesin film 20 with a silicone adhesive and drying it. Next, after the rubber sheet 17 and the glass cloth 18 are overlapped with the adhesive layer 19 of the fluororesin film 20, the adhesive rubber layer 19 is cured and bonded to obtain the buffer rubber sheet 16 shown in FIG.

  As shown in FIG. 2A, the obtained cushioning rubber sheet 16 is placed (set) between the conductive thin film 12 and the connecting jig 11. In this state, the connecting jig 11 is heated to 400 ° C., for example, and as shown in FIG. 2B, the anisotropic conductive film having one side edge in the length direction provided on the edge of the panel 14 is provided. 13, the conductive thin film 12 is pressed and heated, and the conductive thin film 12 is pressure-bonded to the panel 14.

  At this time, although the rubber sheet 17 is heated, since it is integrated with the glass cloth 18, thermal expansion is suppressed and thermal expansion of the fluororesin film 20 is also suppressed. Therefore, the adhesive force between the rubber sheet 17 and the fluororesin film 20 is sufficiently maintained even at high temperatures.

The effects exhibited by the above embodiment will be described collectively below.
In the present embodiment, the shock-absorbing rubber sheet 16 having heat resistance and releasability has a glass cloth 18 integrated on one surface of the rubber sheet 17 and a fluororesin having a melting point of 300 to 350 ° C. having an adhesive layer 19. The film 20 is configured to be bonded to the glass cloth 18 by the adhesive layer 19. Since the rubber sheet 17 is made of fluoro rubber or silicone rubber, it has heat resistance and is integrated with the glass cloth 18 so that thermal expansion is suppressed. Further, since the adhesive layer 19 of the fluororesin film 20 is bonded not to the rubber sheet 17 having a large thermal expansion but to the glass cloth 18 having a small thermal expansion, good adhesiveness is exhibited. For this reason, when the buffer rubber sheet 16 is exposed to a high temperature, the occurrence of a difference in thermal expansion is suppressed by the glass cloth 18 between the rubber sheet 17 and the fluororesin film 20, and the adhesive force is maintained. Therefore, the adhesiveness between the rubber sheet 17 and the fluororesin film 20 is excellent, and the durability can be improved. Therefore, the setting of the buffer rubber sheet 16 can be simplified and the heat transfer advantage can be obtained.

  Further, the rubber sheet 17 and the glass cloth 18 are integrated by heating and vulcanizing the glass cloth 18 on one side of the unvulcanized rubber sheet 17 containing the vulcanizing agent. Thus, the rubber sheet 17 and the glass cloth 18 can be integrated easily and reliably. In addition, since the rubber sheet 17 and the glass cloth 18 are integrated, the heat transfer resistance at the interface can be reduced as compared with a case where the rubber sheet 17 and the glass cloth 18 are joined separately, and as a result, the temperature of the connecting jig 11 is lowered. Can do.

  -Furthermore, since the fluororesin film 20 is a film formed of a polytetrafluoroethylene resin or a tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin, the heat resistance can be sufficiently exhibited.

  -Since the adhesive agent which forms the adhesive bond layer 19 is a silicone type adhesive agent, the affinity with respect to the glass cloth 18 improves, and it can improve adhesive force.

Hereinafter, the embodiment will be described more specifically with reference to examples and comparative examples.
Example 1
Silicone rubber with characteristics of thickness 200μm, hardness (JIS K6249 type A hardness) 65 °, volume resistivity 50Ω · cm (GE Toshiba Silicone Co., Ltd., XE23-B6367, conductive millable silicone rubber) A calendar prepared by mixing and dispersing 100 parts by mass with 2 parts by mass of a vulcanizing agent (TC-8,2,5-dimethyl-2,5-ditertiary butyl peroxyhexane, manufactured by GE Toshiba Silicone Co., Ltd.) Processing was performed to prepare an unvulcanized rubber sheet 17. A glass cloth 18 having a thickness of 40 μm was bonded to one side of the obtained rubber sheet 17 and vulcanized by heating at 170 ° C. for 10 minutes to integrate the glass cloth 18 with the rubber sheet 17.

  On the other hand, an adhesive layer 19 having a thickness of 30 μm was provided by coating a silicone adhesive on the surface of a fluororesin (polytetrafluoroethylene, PTFE) film having a thickness of 25 μm. Then, the adhesive layer 19 was adhered to the glass cloth 18, whereby the release fluororesin film 20 was adhered to the rubber sheet 17, and the buffer rubber sheet 16 was obtained.

About the obtained rubber sheet 16 for buffering, durability was evaluated by the following method. That is, the deformed state of the rubber sheet 17 was visually observed after repeating the pressure bonding 10 times under the pressure bonding conditions of a temperature of 350 ° C., a pressure of 5 MPa, and a time of 20 seconds. The results are shown in Table 1.
(Examples 2-5 and Comparative Examples 1-3)
The same procedure as in Example 1 was performed except that the material and thickness of the rubber sheet 17, the type and thickness of the glass cloth 18, and the type and thickness of the fluororesin film 20 were changed as shown in Table 1. Here, in Comparative Example 1, FEP having a low melting point was used as the material of the resin film, and in Comparative Examples 2 and 3, the glass cloth 18 was not used. The obtained rubber sheet 16 for cushioning was evaluated for durability in the same manner as in Example 1, and the results are shown in Table 1. In addition, the symbol in Table 1 is shown next.

PTFE: polytetrafluoroethylene resin (melting point 327 ° C.)
PFA: Tetrafluoroethylene-perfluoroalkoxyethylene (perfluoroalkyl vinyl ether) copolymer resin (melting point: 302 to 310 ° C.)
FEP: Tetrafluoroethylene-hexafluoropropylene copolymer resin (melting point: 253-282 ° C.)

表１に示したように、実施例１〜５のいずれも耐久性の評価で、緩衝用ゴムシート１６の変形は見られなかった。これに対して、比較例１では、樹脂フィルムの材料として融点の低いＦＥＰを使用したため、１回の圧着で樹脂フィルムと異方導電性フィルム１３とがくっつく結果となった。さらに、比較例２及び３ではガラスクロス１８を使用しなかったため、ゴムシート１７とフッ素樹脂フィルム２０との間で剥離が発生した。

As shown in Table 1, any of Examples 1 to 5 was evaluated for durability, and deformation of the buffer rubber sheet 16 was not observed. On the other hand, in Comparative Example 1, since FEP having a low melting point was used as the material of the resin film, the resin film and the anisotropic conductive film 13 were adhered to each other by one press bonding. Further, in Comparative Examples 2 and 3, since the glass cloth 18 was not used, peeling occurred between the rubber sheet 17 and the fluororesin film 20.

In addition, this embodiment can also be changed and embodied as follows.
When the adhesive layer 19 is formed on the surface of the fluororesin film 20, a primer layer for promoting adhesion can be formed on the surface of the fluororesin film 20 in advance.

  As a vulcanizing agent used for vulcanizing the unvulcanized rubber sheet 17, polyamine, carbamate, or the like can be used. Furthermore, secondary cross-linking can be performed as necessary. The secondary cross-linking can be performed, for example, by heating in a hot air oven under conditions of 180 to 260 ° C. and 2 to 8 hours.

The integration of the rubber sheet 17 and the glass cloth 18 may be performed by impregnating rubber on one side of the glass cloth 18 and then curing the rubber.
The glass cloth 18 can be integrated on both sides of the rubber sheet 17. In that case, integration of the rubber sheet 17 and the glass cloth 18 is performed by heating and vulcanizing the glass cloth 18 in a state where the glass cloth 18 is bonded to both surfaces of the unvulcanized rubber sheet 17 containing a vulcanizing agent. . The release fluororesin film 20 is bonded to one or both of the glass cloths 18.

Further, the technical idea that can be grasped from the embodiment will be described below.
The heat resistance and mold release according to any one of claims 1 to 4, wherein the rubber sheet has a thickness of 150 to 500 µm, and the glass cloth has a thickness of 10 to 100 µm. Rubber sheet for cushioning. When comprised in this way, in addition to the effect of the invention which concerns on any one of Claims 1-4, the buffer property of the rubber sheet for buffering and the reinforcement property of a rubber sheet can be improved.

  The rubber sheet for buffering having heat resistance and releasability according to claim 1, wherein the glass cloth is integrated on one side of the rubber sheet. In this case, the effect of the invention according to claim 1 can be effectively exhibited.

(A) is sectional drawing which shows the rubber sheet for buffering in embodiment which actualized this invention, (b) is the elements on larger scale of (a). (A) is sectional drawing which shows the state which has arrange | positioned the rubber sheet for buffering between an electroconductive thin film film and the jig for connection, (b) is the state which crimps | bonds an electroconductive thin film film to a panel with a jig for connection after that. FIG.

Explanation of symbols

  16 ... rubber sheet for buffering, 17 ... rubber sheet, 18 ... glass cloth, 19 ... adhesive layer, 20 ... fluororesin film for mold release.

Claims (4)

A glass cloth is integrated on at least one surface of a rubber sheet made of fluorine rubber or silicone rubber, and a release fluororesin film having an adhesive layer having a melting point of 300 to 350 ° C. is bonded to the glass cloth by the adhesive layer. A cushioning rubber sheet having heat resistance and releasability, wherein the rubber sheet is configured as described above. The integration of the rubber sheet and the glass cloth is performed by heating and vulcanizing with the glass cloth bonded to at least one surface of an unvulcanized rubber sheet containing a vulcanizing agent. The shock-absorbing rubber sheet according to claim 1, which has heat resistance and releasability. The said release fluororesin film is a film formed of polytetrafluoroethylene resin or tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin, according to claim 1 or 2. A rubber sheet for cushioning having heat resistance and releasability. The rubber sheet for buffering having heat resistance and releasability according to any one of claims 1 to 3, wherein the adhesive forming the adhesive layer is a silicone-based adhesive.

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