JP2008230244A - Manufacturing method for fuel hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a fuel hose, which can prevent the separation of an outside rubber layer at a leading end. <P>SOLUTION: In this manufacturing method for the fuel hose comprising a resin layer 12 and the outside rubber layer 13 superposed on the outer periphery of the resin layer 12, after the resin layer 12 is formed by extrusion molding, microwave plasma treatment is applied to an outer peripheral surface of the resin layer 12 under reduced pressure in advance of the extrusion molding of the outside rubber layer 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a fuel hose having a structure in which a resin layer is formed in a rubber layer.

  As a fuel hose for automobiles (fuel transport hose), in order to improve low fuel permeability, fluorine having low fuel permeability as an intermediate layer in a peripheral wall (rubber layer) constituting the fuel hose. A material in which a resin layer made of a resin such as a resin is formed has been proposed (see, for example, Patent Document 1).

That is, the structure of the fuel hose has a three-layer structure in which an inner rubber layer / resin layer / outer rubber layer is formed. The hose is usually manufactured by extrusion from the inner layer in order. Is done.
JP 2004-150457 A

  By the way, the outer rubber layer has a high temperature at the time of extrusion molding and is then naturally cooled. At this time, the outer rubber layer tends to shrink in the axial direction of the hose as the temperature decreases after extrusion. In addition, the outer rubber layer and the inner resin layer have a weak adhesive force. For these reasons, the outer rubber layer is peeled off from the resin layer at the tip of the hose and gradually increases in diameter toward the tip. If the tip portion remains in such an expanded state, there is a difficulty in that the tip portion does not adhere to the resin layer in the subsequent process, or the appearance deteriorates. Therefore, the tip is tied with a tape or string to prevent the outermost rubber layer from peeling off (expanding diameter), but such work hinders the production efficiency, so improvement is achieved. It has been demanded.

  In addition, when the manufactured hose is shipped as a product, the tip portion with the enlarged diameter is cut, so that there is a problem that the material cost of the tip portion is wasted.

  The present invention has been made in view of such circumstances, and provides a method for producing a fuel hose capable of increasing the adhesive force between the outer rubber layer and the resin layer so that the outer rubber layer at the tip is not peeled off. Objective.

  In order to achieve the above object, a method for producing a fuel hose according to the present invention is a method for producing a fuel hose comprising a resin layer and an outer rubber layer laminated on the outer periphery of the resin layer, wherein the resin layer is formed by extrusion molding. Then, prior to extrusion molding of the outer rubber layer, the outer peripheral surface of the resin layer is subjected to microwave plasma treatment under reduced pressure.

  That is, in the method for producing a fuel hose of the present invention, the outer peripheral surface of the inner resin layer is subjected to microwave plasma treatment under reduced pressure prior to extrusion molding of the outer rubber layer. Thereby, the outer peripheral surface can be formed into an appropriate rough surface, and even if the treatment is a short-time treatment, the contact angle of the treated surface with water can be significantly reduced. And the high tack property comes to be obtained in the outer peripheral surface of the resin layer which carried out the microwave plasma process under pressure reduction. This is thought to be due to the fact that the treated surface is exposed to the atmosphere and functional groups such as hydroxyl groups and carboxyl groups are attached. For this reason, when the outer rubber layer is extruded on the outer peripheral surface of the resin layer subjected to the microwave plasma treatment, the outer rubber layer strongly adheres to the outer peripheral surface of the resin layer. As a result, even if the outer rubber layer is cooled and tends to contract in the axial direction of the hose, the outer rubber layer is not peeled off from the resin layer at the tip, and does not expand.

  In the corona arc discharge that has been conventionally performed as a surface modification treatment, there is a problem that pinholes are likely to be generated due to frequent occurrence of abnormal discharge, and that local treatment is likely to occur. Further, in general plasma processing excluding microwave plasma processing, for example, RF vacuum plasma processing with a high frequency (RF) power source having a frequency band of about 13.56 MHz, a problem that tackiness is not improved so much, There is a problem that the reforming speed is slow. Therefore, even if such a treatment is performed on the outer peripheral surface of the resin layer, the surface modification effect as good as that of the microwave plasma treatment cannot be obtained.

  Since the outer surface of the inner resin layer is subjected to microwave plasma treatment under reduced pressure prior to extrusion of the outer rubber layer, the fuel hose manufacturing method of the present invention has an outer periphery of the resin layer subjected to microwave plasma treatment. The outer rubber layer can be formed on the surface with a strong adhesive force, and peeling (expansion) at the tip of the outer rubber layer can be prevented. Moreover, even if the process is a short-time process, the effect of the process can be sufficiently obtained, so that productivity can be improved. As a result, the manufacturing efficiency of the hose can be improved, and the waste of removing the tip of the manufactured hose can be eliminated.

  In particular, according to the method for producing a fuel hose of the present invention, a resin layer made of a fluororesin such as tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV), which has poor mutual adhesion, and its outer peripheral surface Adhesion with the outer rubber layer located in the region can be performed firmly.

  Further, when the microwave plasma is a surface wave plasma, a high-density plasma can be generated in a wide area with a large area. Therefore, a high adhesion ( (Tackiness) is developed.

  In addition, the microwave plasma treatment is performed with microwaves having a frequency of 433 MHz to 2.45 GHz, so that the surface modification can be made better, so that the interlayer adhesion effect is excellent.

  Furthermore, the microwave plasma treatment is performed under a reduced pressure of 1 to 1000 Pa, so that the surface modification is made better, so that the interlayer adhesion effect is excellent.

The microwave plasma treatment is performed in a rare gas atmosphere such as helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe) or in a nitrogen (N ₂ ) atmosphere. Since the surface modification is made better, the interlayer adhesion effect is improved.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to this.

  The fuel hose manufacturing method of the present invention is performed, for example, as follows. That is, first, the inner rubber layer 11 and the resin layer 12 are continuously extruded into a cylindrical shape by the first extruder and the second extruder, respectively, to form a two-layer structure [the inner rubber layer 11 is the outer side, Is a cylindrical hose base 1a of the resin layer 12 (see FIG. 1). Next, the hose base 1a is cut into scales and then introduced into the microwave plasma processing apparatus 40 (see FIG. 3) (batch processing), and the outer peripheral surface of the resin layer 12 is decompressed while rotating the hose base 1a. Microwave plasma treatment under. And after taking out the hose base | substrate 1a from the microwave plasma processing apparatus 40, it introduce | transduces into a 3rd extruder, The cylindrical outer side rubber layer 13 (refer FIG. 2) is extrusion-molded on the outer peripheral surface of the resin layer 12. FIG. In this way, the fuel hose 1 is manufactured. When the fuel hose having the two-layer structure is not provided with the inner rubber layer 11, it can be manufactured by hollow extrusion molding. A resin mandrel can also be used.

  In the method for producing a fuel hose of the present invention, the outer peripheral surface of the resin layer 12 is formed into a rough surface by the microwave plasma treatment under reduced pressure as described above, and the treated surface is exposed to the atmosphere, so that hydroxyl groups and carboxyls are formed. By attaching a functional group such as a group, high tackiness is obtained (surface modification). Therefore, in the resin layer 12 subjected to the microwave plasma treatment, the adhesive force with the outer rubber layer 13 can be increased, and peeling (expansion) at the tip of the outer rubber layer 13 can be prevented. .

  That is, the fuel hose manufacturing method of the present invention is characterized by the microwave plasma treatment under reduced pressure on the resin layer 12, and the extrusion is performed by the first to third extruders performed in the preceding and subsequent steps. Is performed by a conventional method.

  More specifically, the microwave plasma processing apparatus 40 used in the method of manufacturing the fuel hose of the present invention includes, for example, a structure as shown in FIG. In the figure, reference numeral 42 denotes a dielectric plate (quartz plate, alumina plate, etc.), and 43 denotes a metal wall provided with a window hole (for example, a metal provided with a plurality of slit-like window holes 5 as shown in FIG. 4). 49) is a waveguide. The waveguide 49 is connected to a microwave oscillator as shown in the figure, and the microwave oscillator is connected to a microwave power source as shown in the figure. In addition, a power monitor, an isolator, and a matching unit may be connected between the microwave oscillator and the waveguide 49 with a configuration and arrangement known in the art (recommended by a microwave power supply manufacturer, for example). (Not shown). Then, the microwave introduced from the microwave oscillator through the waveguide 49 is incident on the dielectric plate 42 through the window hole of the metal wall 43, whereby high density plasma can be generated. In the figure, reference numeral 41 denotes a box-shaped processing chamber. One end (left end in FIG. 3) of the processing chamber 41 is provided with a shaft 44 for attaching the hose base 1a, and the other end (in FIG. 3). Similarly, a rotation shaft 45 is provided at the right end). The rotating shaft 45 is connected to a variable speed motor provided outside the processing chamber 41 through a Wilson seal 46. The processing chamber 41 has a supply port 47 for supplying gas into the processing chamber 41 (supplying gas in the direction of the arrow in the figure) and a discharge port 48 for discharging the gas in the processing chamber 41 (arrow in the figure). In the direction, the gas is decompressed and exhausted).

  And the microwave plasma process of the hose base | substrate 1a outer peripheral surface (the outer peripheral surface of the resin layer 12) by the said microwave plasma processing apparatus 40 is performed as follows. That is, first, the cylindrical hose base 1a that has been cut and cut is attached to the microwave plasma irradiation apparatus, and then the inside of the processing chamber 41 is evacuated to a reduced pressure state. Then, if necessary, a plasma generating gas is supplied from the supply port 47 into the processing chamber 41. Next, high-density plasma is generated in the processing chamber 41 while the hose base 1a is rotated by a variable speed motor. In this way, the microwave plasma treatment is performed on the outer peripheral surface of the hose base 1a.

  In the apparatus shown in FIG. 3, the pressure difference (decompression) of the gas applied to the dielectric plate 42 becomes larger as the processing chamber 41 becomes wider or larger in area, so that the dielectric plate can withstand this. However, in order not to increase the thickness of the dielectric, it is possible to reduce the pressure difference from the processing chamber by reducing the pressure on the waveguide 49 side. However, in that case, a microwave or a dielectric seal on the microwave oscillator side of the waveguide 49 and a microwave leakage prevention mechanism such as a metal mesh at the exhaust system connecting part on the waveguide 49 side are installed. preferable. Further, when plasma is generated in the waveguide 49, as a solution, it is preferable to reduce the pressure on the waveguide 49 side to 10 Pa or less so as not to generate plasma in the waveguide 49.

  In the present invention, the microwave plasma treatment is performed under reduced pressure as described above. By doing so, even if the treatment is a short treatment, the treatment surface is in contact with water. The corner can be significantly reduced. And the high tack property comes to be obtained in the outer peripheral surface of the resin layer processed with the microwave plasma. The treatment time of the microwave plasma treatment that can obtain such an effect may be a short time, preferably 1 to 60 seconds.

  In particular, as in the apparatus shown in FIG. 3, when the microwave plasma is a surface wave plasma, a high-density plasma can be generated in a wide area with a large area. High adhesion (tackiness) comes to be expressed on the outer peripheral surface.

  Note that the microwave plasma treatment is preferably performed using microwaves having a frequency of 433 MHz to 2.45 GHz, and more preferably, treatment using microwaves having a frequency of 846 MHz, 896 MHz, 915 MHz, or 2.45 GHz. That is, by performing the treatment with the microwave having such a frequency, the surface modification can be more satisfactorily performed within the range of the Radio Law.

  In addition, the microwave plasma treatment is preferably performed under a reduced pressure of 1 to 1000 Pa because surface modification is better performed. The pressure in the processing chamber 41 is reduced using a pump or the like.

Examples of the plasma generating gas used in the microwave plasma treatment include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) rare gas, or nitrogen (N ₂ ). Among them, helium (He), argon (Ar), and nitrogen (N ₂ ) are preferable from the viewpoints of economy and ionization. These plasma generating gases are used alone or in combination of two or more.

  In addition, as described above, when the microwave plasma treatment is performed while rotating the cut hose base 1a in the processing chamber 41 as described above, the processing can be performed more uniformly. preferable.

  In addition, the structure of the microwave plasma processing apparatus used for the manufacturing method of the fuel hose of the present invention is limited to the structure as shown in FIG. 3 as long as the microwave plasma processing can be performed under reduced pressure. Is not to be done.

  Examples of the material for forming the resin layer 12 to be subjected to the microwave plasma treatment include tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV), tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride-par. Fluoroalkyl vinyl ether copolymer, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (CTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), ethylene-tetrafluoroethylene Copolymer (ETFE), hexafluoropropylene-tetrafluoroethylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), etc. Heat of polyamide resin, aromatic polyamide, polyamide 11 (PA11), polyamide 11 (PA12), polyamide 6 (PA6), etc., ethylene-vinyl alcohol copolymer, polyester resin, polyarylene sulfide such as PPS, etc. A plastic resin. In particular, fluorine such as tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV), tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride-perfluoroalkyl vinyl ether copolymer because of its excellent low fuel permeability. Resins are preferred. When the resin layer 12 is a fluororesin layer, it is preferable in terms of interlayer adhesion that the microwave plasma treatment is performed in a non-oxygen atmosphere. Moreover, the thickness of this resin layer 12 is normally set to the range of 20-500 micrometers.

  According to the method for producing a fuel hose of the present invention, the resin layer 12 made of a fluororesin such as tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer (THV) having poor mutual adhesion (tackiness). However, the adhesiveness (tackiness) with the outer rubber layer 13 located on the outer peripheral surface can be firmly performed. This factor was examined by analyzing the C1s binding energy situation after each treatment on the inner peripheral surface of the fluororesin (THV815 manufactured by Dinion Co., Ltd.) with ESCA (X-ray photoelectron spectrometer). As shown in the graph of, when the microwave plasma treatment (10 second plasma treatment) is performed rather than the blank (untreated product) and the reduced pressure radio frequency (RF) plasma treatment (10 second plasma treatment), It was found that the C—F bond decreased and the C—O bond, C═O bond, C—H bond, etc. increased instead. This is presumably because fluorine atoms on the inner layer surface (outer peripheral surface) are released by the above treatment, and instead the treated surface is exposed to the atmosphere, and functional groups such as hydroxyl groups and carboxyl groups are attached. And it is thought that this functional group increases the hydrophilicity of the inner layer surface and contributes to the improvement of the interlayer adhesion. The chemical analysis can be analyzed by FT-IR in addition to ESCA (for example, ESCA5600 manufactured by ULVAC-PHI).

  The material for forming the outer rubber layer 13 formed on the outer peripheral surface of the resin layer 12 is, for example, acrylonitrile-butadiene copolymer rubber (NBR), NBR-PVC blend material obtained by blending NBR and polyvinyl chloride (PVC), Fluorine rubber (FKM), acrylic rubber (ACM), hydrin rubber, epichlorohydrin rubber, ethylene-propylene-diene terpolymer rubber (EPDM), natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR) Butyl rubber (IIR), halogenated-IIR, chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), chlorinated polyethylene rubber (CPE), and the like. In particular, the above-mentioned NBR, NBR-PVC blend material, hydrin rubber, CSM, CPE, etc., which are excellent in wear resistance, impact resistance, weather resistance, etc., are preferred for fuel hose applications. Moreover, the thickness of the outer rubber layer 13 is usually set in a range of 0.2 to 4 mm.

  The forming material of the inner rubber layer 11 formed on the inner peripheral surface of the resin layer 12 is the same as the forming material of the outer rubber layer 13, for example, acrylonitrile-butadiene copolymer rubber (NBR), NBR and poly NBR-PVC blend material blended with vinyl chloride (PVC), fluorine rubber (FKM), acrylic rubber (ACM), hydrin rubber, epichlorohydrin rubber, ethylene-propylene-diene terpolymer rubber (EPDM), natural rubber (NR) ), Butadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber (IIR), halogenated-IIR, chloroprene rubber (CR) and the like. In particular, the above-mentioned NBR, NBR-PVC blend material, FKM, etc., which are excellent in fuel resistance, are preferred for fuel hose applications. Moreover, the thickness of this inner rubber layer 11 is normally set in the range of 0.2 to 4 mm.

  In the above embodiment, the fuel hose 1 to be manufactured has a three-layer structure (inner rubber layer 11 / resin layer 12 / outer rubber layer 13). However, as described above, the inner rubber layer 11 is not provided, A fuel hose having a layer structure may be used. Further, a reinforcing layer formed by wrapping polyester reinforcing yarn or carbon fiber, another rubber layer, a resin layer, or the like may be formed on the outer periphery of the outer rubber layer 13. Further, a plurality of the resin layers 12 may be laminated so that the resin material of each layer is different. Further, another layer may be formed on the inner circumference of the inner rubber layer 11.

  The fuel hose 1 is used for automobiles, transportation equipment (industrial transportation vehicles such as airplanes, forklifts, excavators, cranes, railway vehicles, etc.) and the like, gasoline, alcohol mixed gasoline (gasohol), alcohol, hydrogen, It is suitably used as a fuel transportation hose for light oil, dimethyl ether, diesel, CNG (compressed natural gas), LPG (liquefied petroleum gas) and the like.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  As described below, a fuel hose having a three-layer structure was produced in the same manner as in the above embodiment, using the respective forming materials for the inner rubber layer, the resin layer, and the outer rubber layer.

(Preparation of inner rubber layer forming material)
NBR (manufactured by Nippon Zeon Co., Ltd., Nipol DN101) 100 parts by weight (hereinafter abbreviated as “part”), SRF (manufactured by Tokai Carbon Co., Ltd., Seast S), and plasticizer (manufactured by Asahi Denka Co., RS107) 20 parts And 5 parts of zinc oxide, 0.5 parts of sulfur, 2.1 parts of Noxeller TET (Ouchi Shinsei Co., Ltd.) which is a vulcanization accelerator, and Noxeller CZ (Ouchi Shinsei Science Co., Ltd.) which is a vulcanization accelerator. (Manufactured) 1.5 parts was added and kneaded using a Banbury and a mixing roll to prepare a material for forming the inner rubber layer.

[Material for forming resin layer]
A fluororesin (Dyneon, THV-815) was prepared.

(Preparation of outer rubber layer forming material)
100 parts NBR + PVC (Nippon ZEON Corporation, Nipol DN508SCR) 50 parts, SRF (Tokai Carbon Co., Seast S) 50 parts, plasticizer (Asahi Denka Co., RS107) 30 parts, zinc oxide 5 parts, sulfur 0 .5 parts, 2.1 parts of Noxeller TET (made by Ouchi Shinsei Co., Ltd.) which is a vulcanization accelerator, and 1.5 parts Noxeller CZ (made by Ouchi Shinsei Science Co., Ltd.) which is a vulcanization accelerator, A material for forming the outer rubber layer was prepared by kneading using a Banbury and a mixing roll.

[Production of fuel hose]
The inner rubber layer (inner diameter: 23 mm, thickness: 2 mm) and the resin layer (thickness: 150 μm) were continuously extruded into cylindrical shapes by the first and second extruders, and the hose base was produced. The scale was cut to a length of 40 cm. The hose substrate thus obtained was introduced into a microwave plasma processing apparatus, and the outer peripheral surface of the resin layer was subjected to microwave plasma processing. This microwave plasma treatment is performed under a reduced pressure of 13 Pa under an argon gas atmosphere while rotating the hose base (rotating at a speed of 1 rotation / second) with a reduced pressure microwave plasma processing apparatus as shown in FIG. The surface treatment (treatment by surface wave plasma) was performed for 2 seconds with microwaves having a frequency of 2.45 GHz. Thereafter, the hose base was introduced into a third extruder, and a cylindrical outer rubber layer (thickness 2 mm) was extruded on the outer peripheral surface of the resin layer. Thus, a fuel hose having a three-layer structure (inner diameter: 23 mm, outer diameter: 31 mm) was manufactured.

[Comparative Example 1]
In Example 1, instead of the microwave plasma treatment, RF vacuum plasma treatment (argon gas atmosphere; 67 Pa reduced pressure) with a frequency of 13.56 MHz was performed. The processing time was 60 seconds. Other than that was carried out similarly to the said Example 1, and obtained the fuel hose of 3 layer structure.

  Using the fuel hoses of Example 1 and Comparative Example 1 manufactured as described above, measurement and evaluation were performed according to the following methods.

[Peel test]
A peel test was performed in accordance with JIS-K6330. That is, the hose of the example product and the comparative product was cut into a ring shape so as to have a length of 25 mm, and further cut in the longitudinal direction to obtain a test sample. Next, a part of the end of the outer rubber layer was peeled off from the cut surface of this test sample, the peeled end was fixed to a gripping jig of a tensile tester, and a tensile test was performed at a pulling speed of 50 mm / min. The peel strength between the two layers (resin layer / outer rubber layer) was determined from the applied load. As a result, in Example 1, an interlayer adhesion of 4 N / cm was obtained, whereas in Comparative Example 1, only an interlayer adhesion of 0.63 N / cm was obtained.

  In addition, in order to see the increase / decrease of the interlayer adhesive force with the change of the processing time with respect to the outer peripheral surface of the resin layer, in Example 1, the interlayer adhesive force after the treatment for 5 seconds, 10 seconds, 20 seconds, and 60 seconds was the same as above. Measured. These results are also shown in Table 1 below.

  From the above results, it can be seen that even if the RF vacuum plasma treatment is performed for a long time, the interlayer adhesion is inferior to that obtained by performing the treatment of the present invention for a short time.

It is a schematic diagram which shows the hose base | substrate which consists of an inner side rubber layer and a resin layer. It is a schematic diagram which shows the fuel hose which consists of an inner side rubber layer, a resin layer, and an outer side rubber layer. It is explanatory drawing which shows a microwave plasma processing apparatus typically. It is a front view which shows an example of the metal wall provided with the window hole used for the said apparatus. It is a graph which shows the C1s bond energy condition of the fluororesin inner layer outer peripheral surface after each process by ESCA analysis.

Explanation of symbols

12 Resin layer 13 Outer rubber layer

Claims (10)

  A method for producing a fuel hose comprising a resin layer and an outer rubber layer laminated on the outer periphery of the resin layer, and after forming the resin layer by extrusion, prior to extruding the outer rubber layer, A method for producing a fuel hose, wherein the outer peripheral surface of the resin layer is subjected to microwave plasma treatment under reduced pressure.   The method for producing a fuel hose according to claim 1, wherein the microwave plasma is a surface wave plasma.   The method for producing a fuel hose according to claim 1 or 2, wherein the microwave plasma treatment is performed by a microwave having a frequency of 433 MHz to 2.45 GHz.   The method for producing a fuel hose according to any one of claims 1 to 3, wherein the microwave plasma treatment is performed under reduced pressure of 1 to 1000 Pa. The microwave plasma treatment is performed in an atmosphere of at least one rare gas selected from the group consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe) or nitrogen (N ₂ The method for producing a fuel hose according to any one of claims 1 to 4, which is performed in an atmosphere.   The method for producing a fuel hose according to any one of claims 1 to 5, wherein the microwave plasma treatment on the outer peripheral surface of the resin layer is performed while rotating a hose base body having the resin layer as an outermost layer.   The method for producing a fuel hose according to any one of claims 1 to 6, wherein the resin layer is made of a fluororesin, and the outer rubber layer is made of a blend material of acrylonitrile-butadiene copolymer rubber and polyvinyl chloride, or hydrin rubber.   The method for producing a fuel hose according to claim 7, wherein the fluororesin is a tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer or a tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride-perfluoroalkyl vinyl ether copolymer.   The said fuel hose is equipped with the inner side rubber layer in the inner periphery of the resin layer, and formation of the said resin layer is performed by the extrusion molding to the said inner side rubber layer outer peripheral surface. The manufacturing method of the fuel hose as described in 2.   The method for producing a fuel hose according to claim 9, wherein the inner rubber layer is made of acrylonitrile-butadiene copolymer rubber or a blend material of acrylonitrile-butadiene copolymer rubber and polyvinyl chloride.

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