JP2016088039A - Fluororesin composite sheet and method for bonding fluororesin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluororesin composite sheet that has a backing material capable of suppressing deterioration in adhesive strength with time even due to ultraviolet rays and temperature change as much as possible in adhesively bonding a fluororesin film to an object surface using an adhesive and has versatility and to provide a method for bonding a fluororesin film.SOLUTION: A fluororesin composite sheet is used, which is produced by thermally welding, on the rear face of a molten fluororesin film, a backing material having at least a molten fluororesin fiber made of the same material as the molten fluororesin film integrated with one kind or two or more kinds of base material fibers selected from among a glass fiber, a carbon fiber, a metal fiber, an aramid fiber, a polyimide fiber and a polyester fiber. The backing material is produced by thermally welding an outer layer material formed of a woven fabric or a nonwoven fabric composed of the molten fluororesin fiber and the base material fiber or formed of a woven fabric composed of the base material fiber and an intermediate layer material formed of a nonwoven fabric composed of the molten fluororesin fiber and a thermoplastic resin fiber capable of being thermally welded to the base material fiber.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluororesin composite sheet and a method for joining a fluororesin film, and more particularly to a fluororesin composite sheet for adhering a fluororesin film to an object surface or using itself as a sheet material for a tent. Further, the present invention relates to a method for joining a fluororesin film in which the fluororesin film is adhered to the object surface.

  Conventionally, when a non-adhesive fluororesin film is adhered to another object surface, a method of performing a surface modification by imparting a hydrophilic group to the fluororesin film surface by chemical or plasma irradiation is generally used. However, in the ocean where there is a lot of ultraviolet rays or outdoors where the temperature changes every day, the adhesive strength tends to decrease due to the deterioration of the adhesive interface. Here, for the chemical surface modification, a method of treating one side of the film by wet etching using a metal sodium solution is used. However, this method has a problem that it is difficult to handle due to excessive environmental load. Further, the surface modification by plasma irradiation has a drawback that the plasma processing apparatus becomes large and the apparatus cost is high. In addition, storage management from the surface modification of the fluororesin film to the bonding work is required, and not only is there concern about the quality of adhesion due to variations in the modified surface, but also the effect of surface modification over time. There is also a problem of fading.

  Patent Document 1 is a composite sheet in which a fluororesin film, a heat-fusible web including a fluororesin staple fiber having a branch, and a base fabric made of a woven fabric or a knitted fabric are combined in this order, The bond between the fluororesin film and the heat-sealable web is a bond by heat-seal, the bond between the web and the base fabric is a bond in which fibers in the web are thrown into the base fabric, and the base An air-impermeable fluorine-based composite sheet formed by heat-sealing fibers in a web entangled with a fabric is disclosed. Further, as the fluororesin staple fiber having a branch, that is, the fluororesin staple fiber having a branch before heat fusion, a staple fiber of semi-fired PTFE, a staple fiber of fired or semi-fired vinyl ether-modified PTFE, or ethylene- Examples include tetrafluoroethylene copolymer (ETFE) staple fibers, and the heat-fusible web before heat-sealing may be composed only of fluororesin staple fibers having branches, or has branches. It is said that a fluororesin fiber and / or a non-fluororesin fiber other than the fluororesin staple fiber may be included. Further, as the fibers constituting the base fabric, glass fibers, carbon fibers, metal fibers, polyimide fibers, para-aramid fibers, meta-aramid fibers, composite fibers obtained by combining these, or mixed fibers thereof are preferable.

  Patent Document 2 discloses a fluororesin film-coated steel sheet in which a heat-sealing film of a thermoplastic fluororesin film is formed on a surface of a steel sheet by interposing a base treatment layer made of a mixed resin of a fluororesin and a heat-resistant resin. Is disclosed. The reason why the heat treatment durability adhesion, film adhesion, wear resistance, etc. of the fluororesin film-coated steel sheet is improved by interposing the base treatment film is because the S═O or —O— bonding group constituting the heat resistance resin is used. Suppose that it brings about strong bond with the steel sheet surface, and the upper fluororesin film provides strong adhesion due to the affinity with the fluororesin contained in the base treatment layer.

JP 2002-160332 A JP-A-5-162243

  However, since the connection between the web and the base fabric is a connection in which the fibers in the web are thrown into the base fabric in a thrown-in manner, there is a problem in the bonding strength, and the web and the fabric due to secular change. There is a risk of peeling from the base fabric. Moreover, the thing of patent document 2 needs to interpose the mixed resin of a fluororesin and a heat resistant resin as a base | substrate on the surface of a steel plate, and to mount the thermoplastic fluororesin film on it, and to heat-process the whole Therefore, when the steel plate is large or has a three-dimensional shape, the lining operation becomes difficult.

  Therefore, in view of the above-mentioned situation, the present invention intends to solve the problem that when a fluororesin film is bonded to an object surface using an adhesive, a decrease in adhesive strength over time is suppressed as much as possible even by ultraviolet rays or temperature changes. It is in the point which provides the joining method of the versatile fluororesin composite sheet | seat provided with the backing material which can be used, and a fluororesin film.

  In order to solve the above-mentioned problems, the present invention provides at least a molten fluororesin fiber of the same material as the molten fluororesin film, glass fiber, carbon fiber, metal fiber, aramid fiber, polyimide fiber on the back surface of the molten fluororesin film. And the fluororesin composite sheet | seat characterized by heat-welding the backing material integrated with the 1 type (s) or 2 or more types of base fiber selected from polyester fiber was comprised (Claim 1). In the present invention, “the molten fluororesin fiber and the base fiber are integrated” means that the fibers are physically intertwined, and the molten fluororesin fiber is thermally welded to the molten fluororesin film. In that case, the base fiber is also indirectly bonded to the molten fluororesin film.

  Here, the molten fluororesin is preferably one selected from PFA, PVDF, FEP, ETFE, and PCTFE (Claim 2).

  Further, the backing material is more preferably a single layer or a plurality of layers of a woven fabric composed of a continuous fluororesin fiber and a base fiber (Claim 3).

  And it is more preferable that the woven fabric composed of the continuous fibers of the molten fluororesin continuous fiber and the base fiber is a plain woven fabric or a twill woven fabric in which the continuous fibers of the molten fluororesin continuous fiber and the base fiber are alternately arranged ( Claim 4).

  Moreover, it is also preferable that the backing material is a non-woven fabric or a twill woven fabric made of a molten fluororesin long fiber and a base fiber long fiber (Claim 5).

  Further, the backing material is composed of an intermediate layer material and an outer layer material, and the outer layer material is a single layer or a plurality of layers of a woven fabric composed of continuous fibers of a base fiber, and the intermediate layer material is the molten fluorine. A non-woven fabric comprising a molten fluororesin long fiber of the same material as the resin film and a thermoplastic resin long fiber that can be thermally welded to the base fiber, and the intermediate layer material and the outer layer material are disposed on the back surface of the molten fluororesin film. It is also preferable to heat weld (Claim 6).

  Here, it is preferable that the thermoplastic resin long fibers of the intermediate layer material are PET long fibers.

  The outer layer material is more preferably a plain woven fabric made of continuous fibers of base fibers (claim 8).

  And this invention adheres the above-mentioned fluororesin composite sheet to the object surface with an adhesive, and thereby adheres the molten fluororesin film to the object surface via a backing material. (Claim 9).

  The fluororesin composite sheet of the present invention formed as described above has a molten fluororesin fiber of at least the same material as the molten fluororesin film, glass fiber, carbon fiber, metal fiber, aramid fiber, polyimide on the back surface of the molten fluororesin film. Since a backing material in which one or two or more base fibers selected from fibers and polyester fibers are integrated together is heat-welded, a molten fluororesin film, a molten fluororesin fiber, and a molten fluorine The molten fluororesin film and the backing material are firmly integrated by heat-welding the contact parts between the resin fibers, and when the backing material is bonded to another object surface with an adhesive, it adheres to the base fiber. Because it has good compatibility with the agent, it can be firmly bonded, and as a result, a molten fluororesin film with poor adhesion can be used as a backing material. It can adhere well to the surface of the object through. In addition, when an adhesive is applied to a backing material composed of molten fluororesin fibers and substrate fibers, the adhesive penetrates to the gap between the fibers inside the backing material, so that the adhesiveness is further improved. This bonding method is not affected by ultraviolet rays or temperature changes, unlike the etched adhesive interface, and the substrate fibers and fluororesin fibers are hardly deteriorated outdoors. Even underneath, a decrease in the adhesive strength of the fluororesin film can be suppressed as much as possible, and the weather resistance is excellent. Further, when the base fiber is glass fiber, carbon fiber, or metal fiber, shrinkage during heat welding can be suppressed due to the presence of the base fiber.

  In addition, when the backing material is composed of a nonwoven fabric or a woven fabric in which the molten fluororesin fiber and the base fiber are physically entangled, the molten fluororesin film and the molten fluoro The resin fiber and the contact portion between the molten fluororesin fibers are firmly bonded. And in order to reduce surface frictional resistance with a fluid, when forming a riblet-like unevenness | corrugation on the fluororesin film surface, an uneven | corrugated shape can be hold | maintained with a backing material.

  In addition, when the backing material is a single layer or a plurality of layers of a woven fabric composed of a continuous fiber of a molten fluororesin and a base fiber, the tensile strength is increased particularly when it is composed of a plain woven fabric. It is also possible to use the resin composite sheet itself for curtains of various structures as a tent film having high tear strength. In addition, when the fluororesin composite sheet is bonded to the object surface, a concavo-convex shape appears on the molten fluororesin film in accordance with the concavo-convex due to the web of the backing material made of woven fabric.

  Further, the backing material is composed of an intermediate layer material and an outer layer material, and the outer layer material is a single layer or a plurality of layers of a woven fabric composed of continuous fibers of a base fiber, and the intermediate layer material is the molten fluorine. A non-woven fabric comprising a molten fluororesin long fiber of the same material as the resin film and a thermoplastic resin long fiber that can be thermally welded to the base fiber, and the intermediate layer material and the outer layer material are disposed on the back surface of the molten fluororesin film. When heat-welded, the molten fluororesin film and the molten fluororesin fiber of the intermediate layer material are fused together by heat welding in a state where the intermediate layer material and the outer layer material are laminated on the molten fluororesin film. At the same time, the thermoplastic resin long fibers of the intermediate layer material and the base fiber of the outer layer material and the contact portions of the thermoplastic resin long fibers are thermally welded, so that the molten fluororesin film, During ~ It can be integrally welded layer material and the outer layer material to each other. Of course, in this case as well, since the base fiber is present in the outermost layer, it can be firmly adhered to the surface of another object with an adhesive.

  When the fluororesin composite sheet of the present invention is adhered to the surface of a seawater immersion structure such as a ship, it can suppress the attachment of aquatic organisms such as barnacles and can be easily peeled off even if aquatic organisms adhere. This improves the maintainability. Furthermore, corrosion of the steel material can be prevented by adhering the fluororesin composite sheet to the surface of the steel material.

1 shows a fluororesin composite sheet of the present invention, wherein (a) is a cross-sectional view of a basic form in which a molten fluororesin film and a backing material are laminated, and (b) is a cross-section of a form in which the backing material is composed of an intermediate layer material and an outer layer material. FIG. 1 shows a method for bonding a fluororesin film of the present invention, wherein (a) is a partial cross-sectional view of a state in which the fluororesin composite sheet of FIG. 1 (a) is bonded to an adherend, and (b) is a fluorine of FIG. 1 (b). It is a fragmentary sectional view of the state where the resin compound sheet was bonded to the adherend. It is a simplified explanatory view showing a method for manufacturing the fluororesin composite sheet of Example 1. It is the top view which showed typically the example of the woven fabric which consists of a molten fluororesin continuous fiber and a glass continuous fiber. 3 is a cross-sectional view schematically showing the fluororesin composite sheet of Example 1. FIG. 6 is a simplified explanatory view showing a method for producing a fluororesin composite sheet of Example 2. FIG. It is simplified explanatory drawing which shows the manufacturing method of the fluororesin composite sheet of a comparative example. It is the fragmentary sectional view which showed typically the state which adhere | attached the fluororesin composite sheet which heat-welded the backing material which consists of two layers of woven fabrics on the fluororesin film to the adherend with the adhesive agent.

  The present invention is a joining technique that enables a fluororesin film having poor adhesion to be favorably adhered to another object surface. As shown in FIG. 1 (a), the fluororesin composite sheet A of the present invention has at least a molten fluororesin fiber of the same material as the molten fluororesin film 1, glass fiber, carbon on the back surface of the molten fluororesin film 1. This is a structure in which a backing material 2 in which one or more base fibers selected from fiber, metal fiber, aramid fiber, polyimide fiber and polyester fiber are integrated is heat-welded. In the present embodiment, glass fiber is used as the base fiber, but other carbon fiber, metal fiber, aramid fiber, polyimide fiber, or polyester fiber may be used alone or in combination or in combination. .

  Here, the molten fluororesin is PFA (melting type tetrafluoroethylene resin), PVDF (polyvinylidene fluoride resin), FEP (copolymer of tetrafluoroethylene and hexafluoropropylene), ETFE (tetrafluoroethylene). Ethylene copolymer of ethylene and ethylene) and PCTFE (polychlorotrifluorinated ethylene resin) can be used favorably. Melting | fusing point is 310 degreeC for PFA, 151-178 degreeC for PVDF, 260 degreeC for FEP, 270 degreeC for ETFE, and 220 degreeC for PCTFE.

  The molten fluororesin fiber in the molten fluororesin film 1 and the backing material 2 is formed by laminating the backing material 2 on the back surface of the molten fluororesin film 1 and heating it to a temperature higher than the melting point of the molten fluororesin while pressing from above and below. And the contact portion between the molten fluororesin fibers in the backing material 2 are also thermally welded to produce the fluororesin composite sheet A. This bonding by welding is not affected by ultraviolet rays or temperature changes, unlike the etched adhesion interface. Moreover, since both the fluororesin fiber and the glass fiber are materials that are hardly deteriorated outdoors, they have excellent weather resistance. Here, the glass fiber in the backing material 2 in the fluororesin composite sheet A is in a form partially exposed on the back surface, and serves as an anchor for bonding the glass fiber to the surface of another object. Glass fiber is a material that is very suitable for bonding, and various ordinary adhesives can be used. Here, the other object surface (bonded object) to which the fluororesin composite sheet A is bonded is not only an iron-based material such as a steel material but also other metal materials that can be bonded with an adhesive, concrete, wood, and the like. It doesn't matter.

  Moreover, in typical embodiment, the said backing material 2 is a single layer or multiple layers of the woven fabric which consists of a fusion | melting fluororesin continuous fiber and a glass continuous fiber. Here, it is more preferable that the woven fabric composed of the molten fluororesin continuous fiber and the glass continuous fiber is a plain woven fabric in which the molten fluororesin continuous fiber and the glass continuous fiber are alternately arranged. By using a woven fabric, the molten fluororesin fiber and the glass fiber are physically entangled, further enhancing the adhesive effect of the adhesive, and the adhesive penetrates into the gaps between the fibers, further increasing the adhesive force. . In addition to plain weave, twill weave and other woven fabrics may be used, but it is desirable that the ratio of the molten fluororesin fiber and glass fiber exposed on the surface is 1: 1.

  In another embodiment, it is also preferable that the backing material 2 is a nonwoven fabric made of molten fluororesin long fibers and glass long fibers. The thickness of the non-woven fabric is easy to adjust, and the contact part between the molten fluororesin long fibers in the non-woven fabric is welded by heat welding, so it is relatively high in strength, and after adhering to other object surfaces, glass fibers In addition to direct adhesion to the adhesive, the adhesive also penetrates between the fibers, so that the molten fluororesin film 1 can be reliably adhered via the nonwoven fabric.

  Further, as shown in FIG. 1B, the backing material 2 is composed of an intermediate layer material 3 and an outer layer material 4, and the outer layer material 4 is a single layer or a plurality of layers of woven fabric composed of continuous glass fibers. The intermediate layer material 3 is a nonwoven fabric composed of a molten fluororesin long fiber made of the same material as the molten fluororesin film and a thermoplastic resin long fiber that can be thermally welded to the glass fiber, and the molten fluororesin film The fluororesin composite sheet B is manufactured by thermally welding the intermediate layer material 3 and the outer layer material 4 to the back surface of 1.

  Also in this case, similarly to the above, the intermediate layer material 3 and the outer layer material 4 are laminated as the backing material 2 on the back surface of the molten fluororesin film 1, and the melting point of the molten fluororesin and the melting point of the thermoplastic resin or higher are applied while pressing from above and below. When the molten fluororesin film 1 and the molten fluororesin fiber of the intermediate layer material 3 and the contact portion between the molten fluororesin fibers are thermally welded, the thermoplastic resin long fiber of the intermediate layer material 3 and The fluororesin composite sheet in which the glass fiber of the outer layer material 4 and the contact portion between the thermoplastic resin long fibers are thermally welded, and the molten fluororesin film 1, the intermediate layer material 3, and the outer layer material 4 are welded and integrated with each other. A is manufactured. In this case, a combination in which the melting point of the molten fluororesin and the thermoplastic resin is close is preferable.

  Here, it is preferable that the thermoplastic resin long fibers of the intermediate layer material are PET (polyethylene terephthalate) long fibers. The melting point of the PET resin is 264 ° C. The PET resin is particularly preferable because it is very excellent in weather resistance, but other thermoplastic resins may be used depending on the melting point of the molten fluororesin.

  The outer layer material 4 is more preferably a plain woven fabric made of continuous glass fibers. A plain woven fabric made of continuous glass fibers suppresses the shrinkage of the molten fluororesin film 1 during heat welding, has high tear strength, and is excellent in weather resistance.

  Then, as shown in FIG. 2, the fluororesin film bonding method of the present invention is obtained by adhering the aforementioned fluororesin composite sheet A or B to an adherend 5 (object surface) with an adhesive, so The resin film 1 is bonded to the adherend 5 via the backing material 2. 2A shows a state in which the fluororesin composite sheet A of FIG. 1A is adhered to the adherend 5, and FIG. 2B shows the fluororesin composite sheet B of FIG. 5 shows a bonded state.

  Thus, the fluororesin composite sheet formed by thermally welding the backing material 2 to the back surface of the molten fluororesin film 1 has high tensile strength and tear strength, and can be used as a single tent film by itself.

Next, Embodiment 1 of the present invention will be described with reference to FIG. Table 1 shows the materials used and the pressure and heating conditions. As the molten fluororesin film 1, an FEP film having a thickness of 50 μm was used. The backing material 2 is a plain woven fabric in which FEP continuous fibers 6 (50 wt%) and glass continuous fibers 7 (50 wt%) are alternately arranged. The plain woven fabric used as the backing material 2 has a vertical and horizontal fiber density of 25.4 fibers / inch and a basis weight of 82.3 g / m ² . FIG. 4 schematically shows a backing material 2 made of plain woven fabric of FEP continuous fibers 6 and glass continuous fibers 7.

  And as shown in FIG. 3, the backing material 2 is laminated | stacked on the back surface of the said FEP film 1, the decorative board for mold release (product made from SUS) 8 and 8 is arrange | positioned on the upper and lower sides, and the board surface temperature was heated to 270 degreeC. The fluororesin composite sheet A is manufactured by thermally welding the FEP film 1 and the backing material 2 while being sandwiched by pressing machines 9 and 2.5 MPa for 10 minutes. FIG. 5 is a cross-sectional view schematically showing the fluororesin composite sheet A manufactured as described above.

Next, a second embodiment of the present invention will be described with reference to FIG. Table 2 shows the materials used and the pressure and heating conditions. As the molten fluororesin film 1, an FEP film having a thickness of 50 μm was used. The backing material 2 includes an intermediate layer material 3 and an outer layer material 4. The intermediate layer material 3 is a nonwoven fabric composed of FEP long fibers (50 wt%) and PET long fibers (50 wt%). The outer layer material 4 is a plain woven fabric made of continuous glass fibers. The fiber density in the vertical and horizontal directions is 18/25 mm in length, 10/25 mm in width, and the basis weight is 707 g / m ² .

  And as shown in FIG. 6, the intermediate | middle layer material 3 and the outer layer material 4 are laminated | stacked as the backing material 2 on the back surface of the said FEP film 1, and the decorative sheet for mold release (made from SUS) 8 and 8 is arrange | positioned on the upper and lower sides. The FEP film 1 and the intermediate layer material 3 and the intermediate layer material 3 and the outer layer material 4 are thermally welded by sandwiching 2.5 MPa for 10 minutes with a press machine 9 and 9 heated to 270 ° C., and the fluororesin composite sheet B Manufacturing.

<Comparative example>
A comparative example will be described with reference to FIG. Table 3 shows the materials used and the pressure and heating conditions. As the molten fluororesin film 1, an FEP film having a thickness of 50 μm was used. The backing material 2 is a plain woven fabric made of continuous glass fibers, and is a prepreg in which a base material is impregnated with a thermosetting epoxy resin. The glass fiber fabric has a vertical / horizontal fiber density of 44/25 mm in length, 22/25 mm in width, and a weight per unit area of 240 g / m ² . As the FEP film, one whose surface was modified by a corona discharge treatment method was used.

  And as shown in FIG. 7, the backing material 2 (prepreg) is laminated | stacked on the back surface of the said FEP film 1, the decorative board for mold release (product made from SUS) 8 and 8 is arrange | positioned on the upper and lower sides, and the board surface temperature is 160 degreeC. The FEP film 1 and the backing material 2 are adhered to each other with a press machine 9, 9 heated between 5 MPa and 10 min to produce a fluororesin composite sheet C.

<Evaluation test>
A weather resistance test was performed on the fluororesin composite sheets of Examples 1 and 2 and Comparative Example. The measuring instrument used was a sunshine weather meter (Suga Test Machine Co., Ltd., WEL-SUN-HCH-B type). The test time is 500 hours, the test conditions are black panel temperature 63 ° C. ± 3 ° C., rainfall conditions (1) rainfall rate 12 min / 60 min, and (2) rainfall 2100 ml ± 100 ml. The evaluation material size of each fluororesin composite sheet was 100 mm × 300 mm, and three sheets were used for each.

  Evaluation items are appearance, contamination, peel adhesion strength, and adhesion.

  The appearance was visually observed for changes before and after the test.

  Contamination was determined by a gray scale for contamination before and after the test (conforms to JIS L 0805). Table 4 shows the criteria for contamination.

  As for the peel adhesive strength, the adhesive strength of the fluororesin film before and after the test was confirmed with a T-type peel test piece (based on JIS K 6854). The evaluation method is based on obtaining the load when the bonded surface is torn by holding the unbonded end with the gripping portion of the testing machine, pulling it at a speed of 10 mm / min in the 90-degree direction of the bonded surface. The test piece dimensions were 300 mm long (225 mm bonded portion) × 25 mm wide, and 5 pieces were cut out from the evaluation materials used in the weather resistance test.

  Adhesiveness evaluated the adhesiveness of the fluorine film before and behind a test by the cross cut tape method (JISK5400 conformity). Table 5 shows the criteria for adhesion.

  Table 6 shows the evaluation results for these evaluation items.

  In the fluororesin composite sheets of Example 1 and Example 2, since the joining method is thermal welding of fluororesin, it can be seen that there is no change before and after the weather resistance test and the joining is maintained. Even if the surface of the fluororesin composite sheet of the comparative example is modified by plasma treatment or corona discharge treatment or chemical treatment on one side of the fluororesin film, the epoxy resin deteriorates due to ultraviolet rays in the weather resistance test, Peeling occurs at the film adhesion part. The fluororesin composite sheets of Example 1 and Example 2 did not change in appearance after the weather resistance test, and almost no contamination was observed. Of course, the peel adhesion strength was sufficiently strong and the adhesion was the highest. It was.

  FIG. 8 shows another embodiment of the present invention, in which a fluororesin in which a backing material 2 in which two layers of a woven fabric made of molten fluororesin continuous fiber and glass continuous fiber are laminated on the back surface of the molten fluororesin film 1 is heat-welded. 3 is a partial cross-sectional view schematically showing a state in which the composite sheet A is bonded to the surface of the adherend 5 with an adhesive 10. FIG.

A, B Fluororesin composite sheet 1 Molten fluororesin film 2 Backing material 3 Intermediate layer material 4 Outer layer material 5 Object 6 FEP continuous fiber 7 Glass continuous fiber 8 Mold release decorative plate 9 Press machine

Claims (9)

  One or two selected from at least a molten fluororesin fiber of the same material as the molten fluororesin film, glass fiber, carbon fiber, metal fiber, aramid fiber, polyimide fiber, and polyester fiber on the back surface of the molten fluororesin film A fluororesin composite sheet obtained by heat-welding a backing material in which at least one kind of base fiber is integrated.   The fluororesin composite sheet according to claim 1, wherein the molten fluororesin is one selected from PFA, PVDF, FEP, ETFE, and PCTFE.   The fluororesin composite sheet according to claim 1 or 2, wherein the backing material is a single layer or a plurality of layers of a woven fabric composed of continuous fibers of molten fluororesin and base fibers.   4. The fluororesin composite sheet according to claim 3, wherein the woven fabric comprising continuous molten fluororesin continuous fibers and base fibers is a plain woven fabric or twill woven fabric in which molten fluororesin continuous fibers and glass continuous fibers are alternately arranged. .   The fluororesin composite sheet according to claim 1 or 2, wherein the backing material is a non-woven fabric composed of a melted fluororesin long fiber and a base fiber.   The backing material comprises an intermediate layer material and an outer layer material, and the outer layer material is a single layer or a plurality of layers of a woven fabric made of continuous fibers of base fibers, and the intermediate layer material is the molten fluororesin film. A non-woven fabric comprising a molten fluororesin long fiber of the same material and a thermoplastic resin long fiber that can be thermally welded to the base fiber, and the intermediate layer material and the outer layer material are thermally welded to the back surface of the molten fluororesin film. The fluororesin composite sheet according to claim 1 or 2.   The fluororesin composite sheet according to claim 6, wherein the thermoplastic resin long fibers of the intermediate layer material are PET long fibers.   The fluororesin composite sheet according to claim 6 or 7, wherein the outer layer material is a plain woven fabric or a twill woven fabric made of continuous fibers of base fibers.   The fluorine resin composite sheet according to any one of claims 1 to 8 is adhered to the object surface with an adhesive, whereby the molten fluororesin film is adhered to the object surface via a backing material. Resin film bonding method.

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