JPH1182822A - Fuel hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve adhesiveness of a fluororesin with regard to a fuel hose used for automobiles and the like by providing the inner circumferential surface of the utmost inner layer of a rubber hose body with a fluororesin layer and forming the fluororesin layer with a copolymer of a vinylidene fluoride and a chlorotrifluoroethylene. SOLUTION: A rubber tube body 1 of a single layer composition is manufactured. Fluororesin powder is stuck and melted on a specific portion of the inner circumferential surface of the rubber tube body 1 by powder coating. As heating methods to be followed in that case are such as putting the rubber tube body 1, whose inner circumferential surface is coated with fluororesin powder, into a heating oven and heating the whole body. A fuel hose 3 with a fluororesin layer 2 formed on a specific portion on the inner circumferential surface of the rubber tube body 1 can be obtained by taking out the rubber tube body 1 having fluororesin powder melted and membraned on it by heating at a final process from the oven and cooling it. The hose 3, which is composed of a bellows 3a in the center and a cylindrical part 3b on both ends, is made the fuel hose 3 by inserting a metal pipe 4 into the cylindrical parts 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel hose used for a fuel pipe of an automobile or the like. The present invention can provide a highly reliable fuel hose having excellent resistance to gasoline, particularly alcohol-blended gasoline, sour gasoline, and the like.

[0002]

2. Description of the Related Art In recent years, since it is necessary to reduce the amount of gasoline released into the atmosphere in relation to environmental issues, regulations on gasoline permeation of fuel hoses used for fuel pipes of automobiles and the like have become increasingly strict. Become an old NB
A single-layer fuel hose made of R / PVC (acrylonitrile-butadiene-polyvinyl chloride blended rubber) or the like cannot sufficiently cope with such gasoline permeation regulations.

[0003] Further, alcohol-blended gasoline used for purifying exhaust gas from automobiles has a higher gasoline permeation rate than gasoline containing no alcohol. Therefore, a fuel hose having more excellent gasoline permeation resistance has been desired. I have.

[0004] Conventionally, there has been a proposal to meet the above demand by forming a fuel hose into multiple layers, in particular, by making one of the layers a fluororesin layer having extremely excellent gasoline resistance. Many have been made. In these proposals, an unvulcanized rubber tubular body and an extruded fluororesin layer are laminated and vulcanized and bonded (the former), and a fluororesin powder is melted by powder coating on a vulcanized rubber tubular body. They can be roughly classified into those to be attached (the latter).

As an example of the former, Japanese Patent Application Laid-Open No. 8-118549
Japanese Patent Application Laid-Open Publication No. H11-157, discloses an invention in which a rubber tubular body made of unvulcanized epichlorohydrin rubber containing an organic phosphonium salt and an extruded fluororesin layer are laminated and vulcanized. JP-A-8-169085 discloses an epichlorohydrin compounded with 1,8-diazabicyclo [5,4,0] undecene-7 salt (hereinafter simply referred to as "DBU salt") and an organic phosphonium salt. An outer rubber tubular body made of unvulcanized rubber or the like, and a DBU
It discloses an invention in which an extruded fluororesin layer is laminated between an unvulcanized NBR or an innermost rubber tubular body made of an unvulcanized fluororubber containing a salt or an organic phosphonium salt and subjected to vulcanization. .

As an example of the latter, Japanese Patent Laid-Open No. 6-255004
In the publication, a fluororesin powder is electrostatically applied to the inner peripheral surface of a vulcanized rubber tubular body, and then heated and cooled to form a two-layer structure in which a fluororesin layer is formed on the inner peripheral surface of the rubber tubular body. An invention for a fuel hose is disclosed. Further, in the present invention, in order to ensure the adhesion between the rubber tubular body and the fluororesin layer, in place of the former vulcanization bonding in the prior art,
The inner periphery of the rubber tubular body is subjected to a pre-adhesion treatment such as a sodium etching treatment, a corona treatment, and a low-temperature plasma treatment.

[0007] Of the above, the former conventional technique has good adhesion between the rubber tubular body and the fluororesin layer by vulcanization adhesion, but since the fluororesin layer is extruded, the layer of the fluororesin layer is extruded. It is difficult to reduce the thickness to, for example, 0.2 mm or less. Although it is possible to make this layer thickness about 0.2 to 0.5 mm, there are considerable technical difficulties in extruding as a good tubular body having no problems in dimensions and quality with this layer thickness. . As a result, there is a problem that the flexibility of the fuel hose is lost due to the fluororesin layer, and the fuel hose is cracked or peeled off due to vibration of the vehicle body.

Further, in the most effective embodiment in which the fluororesin layer is formed on the inner periphery of the rubber tubular body, the fluororesin layer is formed at a point where the sealing property of the hose connection portion is deteriorated, and at a portion such as a bellows shape. There was also a problem that it was difficult.

On the other hand, in the latter prior art, the thickness of the fluororesin layer is set to 0.5 mm or less or 0.1 mm or less.
It is easy to reduce the thickness to 2 mm or less, and the powder coating site for the rubber tubular body can be selected. Therefore, even when the fluororesin layer is formed on the inner periphery of the rubber tubular body, the above-described problem of the sealing property can be avoided, and the fuel hose can be used. The shape of the bellows and the like can be accommodated. Therefore, when focusing on these points, it is considered that the latter conventional fuel hose is more preferable.

[0010]

However, although not pointed out in the invention of the latter, such as the invention disclosed in Japanese Patent Application Laid-Open No. 6-255004, the melting temperature of powder-coated ordinary fluororesin is considerably high. However, there is a problem that the rubber tubular body is thermally degraded when it is melted and adhered to the rubber tubular body and cannot be put to practical use. On the other hand, there are fluororesins such as vinylidene fluoride homopolymer having a low melting temperature. However, these resins have high rigidity, so that the flexibility of the fuel hose is impaired and the adhesiveness becomes insufficient.

Further, since the pre-adhesion treatment such as the sodium etching treatment in the above invention has a problem of complicating the manufacturing process, a simpler and more effective adhesion between the powder-coated fluororesin layer and the rubber tubular body is achieved. It is desirable to develop a means for improving power.

Therefore, the present invention provides a fuel hose having a fluororesin layer in which a fluororesin powder is melt-adhered to the inner periphery of a rubber tubular body by powder coating, to prevent thermal deterioration of the rubber tubular body and maintain flexibility of the fuel hose. It is another object of the present invention to ensure effective adhesion between the rubber tubular body and the fluororesin layer by simple means.

The inventor of the present application has found that, if a fluororesin powder having a predetermined monomer composition is used, it is possible to prevent both thermal deterioration of a rubber tubular body during fusion adhesion and to maintain flexibility of a hose, and the advantage of the powder coating method. By taking advantage of the fact that the fluororesin layer is made thinner, it is possible to further secure the flexibility of the hose, and even with the fluororesin powder coating method,
By compounding the right additives with the right rubber material,
The required adhesion can be achieved without using vulcanized adhesion,
And completed the present invention.

[0014]

[Means for Solving the Problems]

(Structure of the First Invention) A first invention of the present application for solving the above problems.
The invention (invention of claim 1) is a fuel hose including a single-layer or multi-layer rubber tubular body and a fluororesin layer formed on an inner peripheral surface of an innermost layer thereof. A fuel hose in which a fluororesin layer is formed of a copolymer of vinylidene fluoride and chlorotrifluoroethylene.

(Structure of the Second Invention) The structure of the second invention of the present application (the invention according to claim 2) for solving the above problems is as follows.
The layer thickness of the fluororesin layer in the first invention is 0.5 mm
The following is a fuel hose.

(Structure of Third Invention) The structure of the third invention (the invention according to claim 3) for solving the above-mentioned problem is as follows.
The thickness of the fluororesin layer in the second invention is 0.05 to
0.2 mm fuel hose.

(Structure of the Fourth Invention) The structure of the fourth invention (the invention according to claim 4) for solving the above-mentioned problem is as follows.
A fuel hose, wherein the fluororesin layer according to the first to third inventions is formed by melting and adhering a fluororesin powder to the inner peripheral surface of the innermost layer of the rubber tubular body by powder coating.

(Structure of Fifth Invention) The structure of the fifth invention of the present application (the invention according to claim 5) for solving the above problems is as follows.
A fuel hose, wherein the molar ratio of vinylidene fluoride (A) and chlorotrifluoroethylene (B) constituting the fluororesin according to the first to fourth inventions is A / B = 98/2 to 85/15. is there.

(Structure of the Sixth Invention) The structure of the sixth invention of the present application (the invention according to claim 6) for solving the above problems is as follows.
At least the innermost layer of the rubber tubular body according to the first to fifth inventions is formed of an organic ammonium salt, an organic phosphonium salt,
Epichlorohydrin rubber, NBR, fluoro rubber, NBR-P containing at least one polyamine-based additive
It is a fuel hose formed with any of VC.

(Structure of Seventh Invention) The structure of the seventh invention of the present application (the invention according to claim 7) for solving the above problems is as follows.
The fuel hose according to the sixth aspect, wherein the rubber material forming at least the innermost layer of the rubber tubular body contains at least one of the organic ammonium salt and the organic phosphonium salt and the polyamine-based additive. is there.

(Structure of Eighth Invention) The structure of an eighth invention (an invention according to claim 8) for solving the above problems is as follows.
The organic ammonium salt according to the sixth or seventh invention is 1,8-diazabicyclo [5,4,0] undecene-7.
Fuel hose, which is salt.

[0022]

[Action and Effect of the Invention]

(Functions and Effects of the First Invention) In the first invention, a fluororesin layer made of a copolymer of vinylidene fluoride and chlorotrifluoroethylene is formed on the inner peripheral surface of the innermost layer of a single-layer or multilayer rubber tubular body. Therefore, it is possible to provide a highly reliable fuel hose having excellent resistance and permeation resistance to gasoline, particularly alcohol-blended gasoline and sour gasoline.

The fluororesin is melted at a temperature at which the powder does not thermally deteriorate the rubber tubular body, and the formed fluororesin layer is not relatively high in rigidity. Therefore, even when formed by melting and adhering, thermal deterioration of the rubber tubular body can be avoided, and the flexibility of the fuel hose can be maintained. As a result, the adhesion between the rubber tubular body and the fluororesin layer can be improved.

(Functions and Effects of the Second and Third Inventions) In the second and third inventions, the thickness of the fluororesin layer is set to 0.5 mm or less, more preferably 0.05 to 0.2 mm. Thus, the flexibility of the fuel hose can be more sufficiently secured.

Moreover, since the fluororesin layer is made of a copolymer of vinylidene fluoride and chlorotrifluoroethylene, when the fluororesin layer is formed by melting and adhering by powder coating, the effects described above with respect to the first invention are obtained. While maintaining the above, it is possible to easily and satisfactorily perform such thinning of the fluororesin layer.

(Function / Effect of the Fourth Invention) In the fourth invention, since the fluororesin layer is formed on the inner peripheral surface of the innermost layer of the rubber tubular body, the fluororesin layer has improved gasoline resistance and gasoline permeation resistance. It is most effective.

Further, since this fluororesin layer is formed by powder coating of a fluororesin powder composed of a copolymer of vinylidene fluoride and chlorotrifluoroethylene, the rubber hose is not thermally degraded and the fuel hose is made flexible. Properties can be maintained, and the adhesion between the rubber tubular body and the fluororesin layer can be improved. Further, by forming the fluororesin layer except for the inner peripheral surface of the end portion of the rubber tubular body, the sealing property of the hose connection portion can be ensured, and the fluororesin layer can be formed without trouble even on a fuel hose having a bellows shape or the like.

(Function / Effect of Fifth Invention) The molar ratio of vinylidene fluoride (A) to chlorotrifluoroethylene (B) in the fluororesin constituting the fluororesin layer is A / B = 98/2 to 85/15. In particular, the lowering of the melting temperature of the fluororesin powder, the maintenance of the flexibility of the fluororesin layer, and the gasoline permeation resistance are easily compatible.

(Functions and Effects of Sixth to Eighth Inventions) Sixth Invention
In the present invention, a single-layer rubber tubular body or at least an innermost layer of a multilayer rubber tubular body is formed of any of the above-mentioned predetermined types of rubber, and the rubber includes an organic ammonium salt, an organic phosphonium salt, Since at least one kind of polyamine-based additive is contained, even when the fluororesin layer is formed by a powder coating method, the necessary adhesion between the rubber tubular body and the fluororesin layer is not based on vulcanization adhesion. Can be secured.

Such an effect is obtained by combining at least one of an organic ammonium salt and an organic phosphonium salt as in the seventh invention,
This is particularly remarkable when a polyamine-based additive is added, particularly when the organic ammonium salt is a DBU salt as in the eighth invention.

[0031]

Next, embodiments of the first to eighth inventions will be described. In the following, simply "the present invention"
When it says, it refers to 1st invention-8th invention collectively.

[Fuel Hose] The fuel hose of the present invention comprises a single-layer or multi-layer rubber tubular body and a fluororesin layer formed on the inner peripheral surface of the innermost layer. Hoses included without limitation. Although the use of the fuel hose is not limited, it is preferably used for fuel piping of gasoline, particularly alcohol-mixed gasoline and sour gasoline.

[Rubber Tubular Body] The rubber tubular body may have either a single-layer structure or a multi-layer structure. The rubber material constituting the rubber tubular body may be any rubber material used in the field of fuel hose, for example, epichlorohydrin rubber. , NBR, fluoro rubber, NBR-PVC, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, ethylene-propylene rubber and the like may be appropriately selected.

However, in order to enhance the adhesion between the rubber tubular body and the fluororesin layer, at least the innermost layer of the rubber tubular body having a single-layer structure or the rubber tubular body having a multi-layer structure is made of epichlorohydrin rubber, NBR, fluorine rubber. , NBR-PV
It is preferable to form with any of C.

The type of epichlorohydrin rubber is not limited, and any one used in the field of fuel hose may be appropriately selected. More preferably, epichlorohydrin homopolymer (CO), epichlorohydrin and ethylene oxide are used. (ECO) or those obtained by copolymerizing all of these with allyl glycidyl ether can be used.

The type of NBR is not limited, but the amount of bound acrylonitrile is 15 to 45%, especially 25 to 40%.
Are preferred.

The type of the fluororubber is not limited, but is more preferably a copolymer of vinylidene fluoride and 6-propylene fluoride, or a ternary copolymer of vinylidene fluoride and 4-fluoroethylene and 6-propylenepropylene. Vulcanized unvulcanized fluoro rubber such as a polymer, a copolymer of 4-fluoroethylene and propylene, or a blend of polyvinylidene fluoride and acrylic rubber can be used.

Although the type of NBR-PVC is not limited,
More preferably, the amount of bound acrylonitrile is 25-45.
%, Especially 30 to 40%, and a PVC blend amount of 15 to 40%, especially 25 to 35%.

[Additive of Rubber Tubular Body] The rubber material constituting at least the innermost layer of the rubber tubular body having a single-layer structure or the rubber tubular body having a multilayer structure includes organic ammonium salts, organic phosphonium salts, and polyamine-based additives. It is preferable to contain one or two or more of these in order to enhance the adhesion between the rubber tubular body and the fluororesin layer. When two or more kinds are contained, a combination of at least one of an organic ammonium salt and an organic phosphonium salt with a polyamine-based additive is particularly preferred. The polyamine-based additive has a preferable property that it acts as a vulcanizing agent when compounded with hydrin rubber or fluororubber.

The mixing ratio of these additives to the above-mentioned predetermined rubber layer is not particularly limited, but the content of the organic ammonium salt and the organic phosphonium salt is preferably 0.5 to 10 parts by weight per 100 parts by weight of the rubber. Part, particularly preferably 0.1 part.
5 to 7 parts by weight. If the mixing ratio is less than 0.5 part by weight, the effect tends to be insufficient, and if it exceeds 10 parts by weight, there is a concern that the mechanical strength and the compression set may be deteriorated.

On the other hand, the mixing ratio of the polyamine-based additive is preferably 0.1 to 100 parts by weight of rubber.
It is 10 parts by weight, particularly preferably 0.5 to 6 parts by weight.
If the blending ratio is less than 0.5 part by weight, the effect tends to be insufficient, and if it exceeds 10 parts by weight, there is a concern that crack growth in gasoline contact state is deteriorated.

The compounding of these additives with the rubber material constituting the predetermined rubber layer can be carried out by using a usual or known rubber compounding and mixing machine. In particular, it is preferable to use a Banbury mixer, a kneader or the like. Is preferred.

The type of the organic ammonium salt is not limited. For example, various DBU salts such as a carboxylic acid DBU salt and a phenol resin DBU salt can be preferably used from the viewpoint of activating a fluororesin. Examples of the DBU salt of carboxylic acid include D-naphthoic acid shown in the following “Chemical formula 1”.
It is particularly preferable to use a BU salt or a DBU salt of sorbic acid alone or in combination to increase the adhesiveness.

Other examples of the organic ammonium salt include tetrabutylammonium hydrogen sulfate, tetramethylammonium hydrogensulfate, tetraethylammonium hydrogensulfate, trioctylmethylammonium hydrogensulfate, tridodecylmethylammonium hydrogensulfate, and trimethylbenzylammonium hydrogensulfate. Alone or in combination with each other,
Further, it can be preferably used in combination with the above DBU salt.

[0045]

Embedded image

Although the kind of the above-mentioned organic phosphonium salt is not limited, for example, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, tributyl (methoxypropyl) phosphonium chloride, benzyltriphenylphosphonium chloride, benzyltrioctylphosphonium chloride, tetrabutylphosphonium chloride Benzotriazole, trioctylethylphosphonium benzotriazole, tetraphenylphosphonium bromide and the like can be used alone or in combination.

Further, for example, a tetrabutyl group, a tetraoctyl group, a methyltrioctyl group, a butyltrioctyl group, a phenyltributyl group, a benzyltributyl group, a benzyltricyclohexyl group, a benzyltrioctyl group, a butyltriphenyl group, an octyltriphenyl group ,
Phosphonium benzotriazolate or tolyltriazo having one of benzyltriphenyl, diphenyldi (diethylamino), phenylbenzyldi (dimethylamino), trifluoromethylbenzyl, and tetrafluoropropyltrioctyl A rate or the like can also be used.

The type of the above-mentioned polyamine-based additive is not limited. For example, 1,6-hexamethylenediamine, triethylenetetramine, tetraethylenepentamine, triethylenediamine, paraphenylenediamine,
Hexamethylene diamine carbamate, ethylene diamine carbamate, N, N'-dicinnamylidene-1,6
-Hexanediamine, 4,4'-bis (aminocyclohexyl) methane carbamate, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane and the like can be used alone or in combination.

[Fluororesin Layer] In the present invention, the fluororesin layer is composed of a copolymer of vinylidene fluoride (A) and chlorotrifluoroethylene (B), and is one of the innermost layers in a single-layer or multilayer rubber tubular body. It is formed on the peripheral surface.

In this copolymer, the molar ratio of both A and B is not particularly limited, but the molar ratio of A / B is preferably from 98/2 to 85/15. It is more preferable to keep the melting temperature of the fluororesin too low and to maintain the flexibility of the fluororesin layer.

If the ratio of vinylidene fluoride is excessively deviated from the above range of the molar ratio, the melting temperature of the fluororesin increases, and the rigidity of the fluororesin layer increases, thereby increasing the rigidity of the fuel hose. In addition, there is a concern that a problem such as deterioration of adhesion between the rubber tubular body and the fluororesin layer may be caused. On the other hand, if the ratio of vinylidene fluoride is too small, the melting temperature of the fluororesin becomes too low, so that it is not possible to withstand the use temperature and there is a concern that the gasoline permeation resistance deteriorates.

The thickness of the fluororesin layer is not particularly limited. However, from the viewpoint of maintaining the flexibility of the fuel hose and the gasoline permeation resistance, the thickness is more preferably 0.5 mm or less, It is particularly preferable to set it to 0.2 mm.

The fluororesin constituting the fluororesin layer includes:
Various additives such as an antioxidant, a nucleating agent, a plasticizer, a coloring agent, and a flame retardant may be arbitrarily added as long as the action and effect of the present invention are not impaired. [Manufacture of Fuel Hose] The method of manufacturing the fuel hose according to the present invention is not limited as long as it is a substantially feasible method, but one embodiment of the manufacturing method will be described below. In this embodiment, the rubber tubular body has a single-layer structure, and as shown in FIG. 1, both ends are cylindrical and the center is bellows-shaped. It is an example of manufacture of the fuel hose in which the layer was formed.

First, epichlorohydrin rubber, NBR,
An unvulcanized rubber material, either fluororubber or NBR-PVC, is made to contain a DBU salt, injected by an injection molding machine, and vulcanized to produce a single-layer rubber tubular body 1 having the shape shown in FIG. I do.

Next, the fluororesin powder of the present invention is adhered to a predetermined portion of the inner peripheral surface of the rubber tubular body 1 (portion excluding the inner peripheral surface having a constant width from both ends of the opening) by powder coating and fused. Let it. Specifically, air and fluorine resin powder are supplied to the spray gun connected to the high voltage generator through an air pipe and a resin powder supply pipe, and negative or positive is supplied from the injection port of a long nozzle attached to the spray gun. Is sprayed and adhered, and heated and melted to make the fluororesin powder thinner.

As the heating method at this time, for example, a method in which the rubber tubular body 1 whose inner peripheral surface is coated with a fluororesin powder is put into a heating oven to heat the whole, or a method in which the inner peripheral surface is a fluororesin There is a method of inserting a rod-shaped heating device inside the rubber tubular body 1 coated with powder and heating from the inside.
The heating conditions are as follows.
Is appropriately set depending on the type of rubber constituting the above, but is usually from 150 to 250 ° C for 2 to 40 minutes, more preferably from 170 to 240 ° C for 3 to 35 minutes.

In the final step, the rubber tubular body 1 in which the fluorine-based resin powder is melted and thinned by heating is taken out of the oven and cooled, as shown in FIGS. 2 (A) and 2 (B). The fuel hose 3 in which the fluororesin layer 2 is formed on a predetermined portion of the inner peripheral surface of the body 1 can be obtained.
The fuel hose 3 has a bellows portion 3a located substantially in the center area,
And cylindrical end portions 3b located at both ends thereof. At the time of use, for example, as shown in FIG. 3, the other end 3b is used as a fuel hose by inserting and connecting the other end of the metal pipe 4 to the other end 3b.

The thickness of the fluororesin layer 2 in the fuel hose 3 is usually set in the range of 0.05 to 0.2 mm. The thickness of the rubber layer of the rubber tubular body 1 is usually 2-6.
mm, more preferably 3-5 mm.

In the above-mentioned manufacturing process, injection molding by an injection molding machine is described as a method for molding the rubber tubular body 1, but the invention is not limited thereto.
Depending on the shape and the like, a molding method such as extrusion molding can be used.

The rubber tubular body is not limited to the bellows shape as shown in FIG. 1, but may be a straight tube or a curved tube, and further has a single-layer structure as shown in FIG. The innermost layer is preferably epichlorohydrin rubber, NBR, fluoro rubber, NBR-PV
C may have a multilayer structure composed of two or more rubber layers.

When the rubber tubular body has a multilayer structure composed of two or more rubber layers, the rubber tubular body 1 is formed on the outer periphery of the rubber tubular body 1 along the shape of the rubber tubular body 1 with the rubber layer made of another rubber material described above. It is produced by forming Examples of the method for forming the rubber layer include a method in which a first layer is injection-molded and then a second layer is injection-molded on the outer periphery thereof, and a method in which multiple layers are simultaneously extruded.

[0062]

【Example】

[ Hose in which rubber tubular body has a single-layer structure ] Examples 1 to 11, 31 to 36 and 51 to 53 shown in Table 1, Table 2, Table 4 and Table 12 at the end, Comparative Examples 1 to 4 and 7 It is a single-layer rubber tubular body. Examples and comparative examples of these rubber tubular bodies are shown in Table 6 (A1 to A9, S1) at the end and Table 10 (A10 to A15) at the end (parts by weight). The same is true in the notation.) Epichlorohydrin rubber, and N in the formulation shown in Table 9 (V1).
BR-PVC was prepared and this was added to an 160
Vulcanization molding at 5 ° C for 5 minutes, inner diameter 35mm, thickness 4mm,
A single-layer rubber tubular body having a bellows shape with a length of 200 mm was produced.

Next, for Examples 1 to 3 and Comparative Examples 1 to 3, fluororesin powders shown in Table 1 were prepared, and for Examples 4 to 11 and Examples 31 to 36, and Comparative Examples 4 and 7, Although not shown in the table, the same fluororesin powder as in Example 2 was prepared, and for Examples 51 to 53, the same fluororesin powder not shown in the table but as in Example 1 was prepared. These were electrostatically coated to a thickness of 0.2 mm on the inner peripheral surface of the rubber tubular body according to each of the above examples. This electrostatic coating was performed by a corona discharge (minus charge) of 60 kv / 10 μA. Further, the rubber tubular body coated with these fluororesin powders was placed in an oven at 220 ° C.
After heating and melting under the condition of / 25 minutes, the tube was taken out of the oven and cooled, thereby obtaining a hose having a fluororesin layer formed on the inner peripheral surface of the rubber tubular body.

[ Hose having a rubber tubular body having a multilayer structure ] Examples 12 to 30, 37 shown in Tables 3, 5, and 13 at the end
50 to 54 to 60 and Comparative Examples 5 and 6 are rubber tubular bodies having a multilayer structure. For Examples and Comparative Examples of these rubber tubular bodies, see Table 6 (A1) and Table 10 (A10 to
Epichlorohydrin rubber having the composition shown in A15), Tables 7 (B1 to B6, T1) and Table 10 (B7 to B11) at the end.
Table 8 (C1 to C6, U1)
And FKM of the composition shown in Table 11 (C7 to C10), that is, fluororubber, and Table 9 (D1 to D6, V1) and Table 11 at the end
NBR-PVC having the composition shown in (D7 to D11) was prepared, and injection molding with vulcanization was performed under the same conditions as above to first form the inner layer, and then the composition shown in the “Outer layer” column in each of the above tables. The rubber material was subjected to injection molding with vulcanization under the same conditions as above to form an outer layer.

Examples 12 to 30, 37 thus obtained
Next, with respect to the rubber tubular bodies having a bellows shape and having a two-layer structure according to Comparative Examples 5 and 6, Examples 12 to 30 and 37 to 50 are not shown in the table. Is the same fluororesin powder as in Example 2, while Example 5
For 4 to 60, the same fluorine-based resin powder as in Example 1 was prepared, and a fluorine-based resin layer was formed on the inner peripheral surface of the rubber tubular body having a two-layer structure by the same process under the same conditions as described above. I got a new hose.

[ Evaluation of Hose ] Examples 1 to 60 and Comparative Example 1 in which the above-mentioned rubber tubular body has a single-layer structure or a multilayer structure.
For the hoses according to Nos. 1 to 7, the fuel impermeability and the adhesion between the rubber tubular body (in the case where the rubber tubular body has a multilayer structure, the inner layer thereof) and the fluororesin layer were examined as follows,
The results are shown in the table.

In Examples 1 to 3 and Comparative Examples 1 to 3, the film-forming properties (the state of the fluororesin on the inner surface of the rubber tubular body), the flexibility of the hose, and the hose at 100 ° C./7
The tensile elongation at break of the fluororesin layer after being deteriorated under the conditions of 2 hours was also examined as follows, and the results are shown in the table.

(Film Forming Property) The hose was split in half, and the state of film formation of the fluororesin on the inner peripheral surface of the rubber tubular body was evaluated.

(Flexibility) A load (N) was measured when one end of a hose (length: 200 mm) was fixed and the other end was displaced by 200 mm in a direction perpendicular to the axial direction of the hose.

(Tensile Elongation at Break of Fluorine Resin Layer) AS
It was measured according to TM D 638. Specifically, after cutting a strip-shaped fragment in the circumferential direction from the hoses according to the above-described predetermined examples and comparative examples, the strip is measured from the fluorine-based resin layer side to have a thickness of 0.5 mm. Sliced into.

The sliced section was punched with a dumbbell after being subjected to the above-mentioned deterioration conditions, and was cut at a tensile speed of 100 mm / min. And elongation at break was measured.

(Fuel impermeability) First, JIS K62
Fuel C and M15 [methanol /
Fuel C = 15/85 (volume mixing ratio)], two kinds of test gasoline were prepared, sealed in the hoses according to the respective examples, and left at a temperature of 40 ° C. for 168 hours. Next, after replacing the gasoline with the same new gasoline, the gasoline was further left for 72 hours at a temperature of 40 ° C., and the permeation amount of fuel per day was calculated from the change in weight of the renewed gasoline before and after being left, and is shown in the table.

(Adhesion) An adhesion test was performed according to JIS K6256. That is, the end of the hose of each example has a width of 2
It was cut into a ring of 5 mm, and one portion of the ring was cut in the axial direction to obtain a test sample. From the cut surface portion of this test sample, the rubber layer and the fluororesin layer are peeled off from each other by a certain length, and the peeled rubber layer and the end of the fluororesin layer are respectively attached to a gripping jig of a tensile tester. After fixing, the tension speed was 25 mm / min. , And the peel strength between the two layers was determined from the measured load thus obtained, and was used as an initial value.

Next, Fuel in the hose according to the same example was used.
After C was sealed and allowed to stand at 40 ° C. for 72 hours, a test sample was obtained from the hose in the same manner as above, and a tensile test was performed as described above, and the obtained peel strength was defined as a value after fuel was sealed.

From the initial value of the peel strength and the value after fuel filling, a rubber tubular body (when the rubber tubular body has a multilayer structure,
The adhesiveness between the inner layer) and the fluororesin layer was evaluated.

[ Hose Evaluation Results ] From the results in each table, it can be seen that all the hoses of the examples have high adhesiveness and low fuel permeability.

In particular, when the hoses of Examples 1 to 3 were compared with the hoses of Comparative Examples 1 to 3, the former was found to be vinylidene fluoride (VDF) / chlorotrifluoroethylene (CTFE) as a fluorine resin in a molar ratio. = 98 / 2-85
/ 15 to use the fluororesin powder copolymerized in
It can be seen that all the characteristics are particularly excellent.

[0078]

[Table 1]

[0079]

[Table 2]

[0080]

[Table 3]

[0081]

[Table 4]

[0082]

[Table 5]

[0083]

[Table 6]

[0084]

[Table 7]

[0085]

[Table 8]

[0086]

[Table 9]

[0087]

[Table 10]

[0088]

[Table 11]

[0089]

[Table 12]

[0090]

[Table 13]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a rubber tubular body.

FIG. 2A is a cross-sectional view showing an example of the fuel hose of the present invention, and FIG. 2B is a cross-sectional view taken along line XX of FIG.

FIG. 3 is a cross-sectional view illustrating an application of the fuel hose of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rubber tubular body 2 Fluorine resin layer 3 Fuel hose 4 Metal pipe

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor: Kimihiro Murakami 3600, Gezu, Kogai, Komaki, Aichi Pref.

Claims (8)

[Claims] 1. A fuel hose comprising a rubber tubular body comprising a single layer or a multilayer, and a fluororesin layer formed on an inner peripheral surface of an innermost layer thereof, wherein the fluororesin layer is composed of vinylidene fluoride and chlorofluorocarbon. A fuel hose formed of a copolymer of trifluoroethylene. 2. The fuel hose according to claim 1, wherein the thickness of the fluororesin layer is 0.5 mm or less. 3. The layer thickness of the fluororesin layer is from 0.05 to 0.05.
The fuel hose according to claim 2, wherein the fuel hose has a diameter of 0.2 mm. 4. The method according to claim 1, wherein the fluororesin layer is formed by melting and adhering a fluororesin powder to the inner peripheral surface of the innermost layer of the rubber tubular body by powder coating. The fuel hose according to any one of the above. 5. Vinylidene fluoride (A) and chlorotrifluoroethylene (B) constituting the fluororesin
The fuel hose according to any one of claims 1 to 4, wherein the molar ratio of A / B is from 98/2 to 85/15. 6. At least the innermost layer of the rubber tubular body,
It is formed of any one of epichlorohydrin rubber, acrylonitrile butadiene rubber, fluororubber, and acrylonitrile butadiene-polyvinyl chloride blend rubber containing at least one of organic ammonium salt, organic phosphonium salt, and polyamine-based additive. The fuel hose according to claim 1. 7. A rubber material forming at least an innermost layer of the rubber tubular body, wherein at least one of the organic ammonium salt and the organic phosphonium salt and the polyamine-based additive are combined. Claim 6
A fuel hose according to claim 1. 8. The fuel hose according to claim 6, wherein the organic ammonium salt is a 1,8-diazabicyclo [5,4,0] undecene-7 salt.