JPH08104806A - Fuel hose and resin composition therefor - Google Patents

Abstract

PURPOSE: To obtain an inexpensive, high-performance fuel hose free from any problem of safety during its production and having high structural strength. CONSTITUTION: This fuel hose is made up of a tubular inner layer 2 made of a fluororesin and an outer layer 3 made of polyamide resin and directly laminated on the outer peripheral surface of the inner layer 2. The outer layer 3 is made by incorporating 100 pts.wt. of a polyamide resin with (A) 2-20 pts.wt. of at least one of a group II metal oxide and group II metal hydroxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel hose used for a fuel pipe for gasoline or the like in an automobile or the like and a resin composition used therefor.

[0002]

2. Description of the Related Art Generally, in automobiles and the like, a fuel hose used for fuel piping has a multi-layered structure in which layers formed of resins having various characteristics are combined. Among these multi-layer fuel hoses, as shown in FIG.
The inner layer 2 is made of fluororesin, and the outer layer 3a made of polyamide resin is directly laminated on the outer peripheral surface of the inner layer 2
The fuel hose 1 having a layered structure is used as a prize. That is, the fluororesin has excellent corrosion resistance against chemicals and gasoline, and particularly has excellent resistance to sour gasoline produced by oxidation of gasoline (sour gasoline resistance), so that the inner layer that directly contacts the fuel is formed. The best material. Polyamide resin is also suitable as the outer layer of the fuel hose because it has excellent chemical resistance and heat resistance, abrasion resistance, and moldability. As described above, the two-layer fuel hose manufactured by using the fluororesin and the polyamide resin, which are excellent in various characteristics, has high performance and long life as compared with fuel hoses having other configurations.

In the production of such a two-layer fuel hose consisting of a fluororesin inner layer and a polyamide resin outer layer, a special adhesion treatment is performed on the surface of the fluororesin. This is because the fluororesin is difficult to adhere to, so that treatment with an adhesive does not provide sufficient adhesive strength, making it difficult to obtain a fuel hose having practical structural strength. If more adhesive strength is required,
An adhesive such as a urethane adhesive is used after the above-mentioned adhesion treatment. Examples of the adhesion treatment include activation treatment performed under wet conditions such as sodium complex treatment, and plasma treatment such as corona discharge treatment and glow discharge (for example, JP-A 2-10).
No. 7371).

[0004]

Then, a practical fuel hose is manufactured by the above-mentioned bonding process and the subsequent bonding process using an adhesive agent. However, such a bonding process has various problems. First of all, by carrying out such a treatment, the manufacturing process becomes extremely complicated and the manufacturing efficiency is lowered. As a result, the cost of the obtained fuel hose becomes high.
Further, the sodium complex solution used in the above sodium complex treatment, the organic solvent used for dissolving the adhesive, and the like are harmful to the human body, and thus have a safety problem. Further, in order to perform the plasma treatment, special equipment and devices such as a plasma generator and a chamber for maintaining a high degree of vacuum are required, so that the cost of the obtained fuel hose becomes higher.

As described above, the fuel hose manufactured by the conventional method has a problem in safety in manufacturing, and
There is also the problem of high costs. However, as described above, since the fuel hose including the fluororesin inner layer and the polyamide resin outer layer has high performance, the problem of adhesiveness between the above resins is improved, and a problem in terms of manufacturing and cost is solved. It is strongly desired to solve

The present invention has been made in view of the above circumstances, has no problem in safety in production, has high performance, has a high adhesive strength between layers, and is a low-cost fuel hose and a resin composition used therefor. The purpose is to provide.

[0007]

To achieve the above object, the present invention provides a fuel hose comprising a tubular inner layer and an outer layer directly laminated on the outer peripheral surface of the tubular inner layer,
The tubular inner layer is formed of a fluororesin, the outer layer is formed of a polyamide resin containing the following component (A), and the content ratio of the component (A) is 100 parts by weight of the polyamide resin. The first gist is a fuel hose set within a range of 2 to 20 parts by weight. (A) At least one of an oxide of a metal belonging to Group II of the periodic table and a hydroxide of a metal belonging to Group II of the periodic table.

A fuel hose having a tubular inner layer and an outer layer directly laminated on the outer peripheral surface of the tubular inner layer, wherein the tubular inner layer comprises a polyamide resin containing the following component (A): A second fuel hose is formed in which the outer layer is formed by using a fluororesin, and the content ratio of the component (A) is set in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the polyamide resin. Use as a summary. (A) At least one of an oxide of a metal belonging to Group II of the periodic table and a hydroxide of a metal belonging to Group II of the periodic table.

The component (A) is blended with the polyamide resin, and the blending ratio of the component (A) is set within the range of 2 to 20 parts by weight with respect to 100 parts by weight of the polyamide resin. Items are the third gist.

[0010]

That is, the inventors of the present invention, as means for solving the above problems, have focused on a resin composition which is a constituent material of a fuel hose, rather than an improvement of a conventional adhesion treatment such as plasma treatment. Then, the adhesiveness between the fluororesin and the polyamide resin was improved. Then, a fuel hose was manufactured by making a resin composition containing various compositions and additives as a prototype, and an oxide of a metal belonging to Group II of the Periodic Table and a metal belonging to Group II of the Periodic Table shown above were produced. It was found that the polyamide resin containing at least one of the hydroxides of [(A) component] in a specific ratio has excellent adhesiveness to the fluororesin. Therefore, when a fuel hose is manufactured by using this special polyamide resin and a normal fluororesin, the fluororesin inner layer and the polyamide resin can be formed without the need for an adhesion treatment such as a plasma treatment or an adhesion treatment using an adhesive. The inventors have found that it is possible to firmly bond the outer layer with the outer layer, and have reached the present invention. In particular, among the above components (A), magnesium oxide is preferably used as the metal oxide, and calcium hydroxide is more preferably used as the metal hydroxide, from the viewpoint of high reaction efficiency.

As a fuel hose obtained by using the above-mentioned special polyamide resin and fluororesin, in addition to the fuel hose having a fluororesin inner layer and a special polyamide resin outer layer, a special polyamide is used. Even if the fuel hose has a fluororesin outer layer formed on the outer peripheral surface of the resin inner layer and the polyamide resin inner layer, that is, even if the fuel hose has a structure opposite to the above structure, the fluororesin and the polyamide resin respectively have The inventors have found that it is possible to firmly bond both layers to each other by utilizing the excellent characteristics, and arrived at the present invention.

Further, a fuel hose having these structures,
In each fuel hose having a structure including a fluororesin inner layer and a polyamide resin outer layer, and a structure including a polyamide resin inner layer and a fluororesin outer layer, if a conductivity is imparted to either the inner layer or the outer layer, the hose This is more preferable because it is possible to prevent the occurrence of vehicle fire due to the generation of sparks due to static electricity generated by the flow of fuel inside.

In the fluororesin inner layer or the fluororesin outer layer, the flexural modulus is 100 to 1
When the pressure is set to 700 MPa, the flexibility is excellent, and the attaching property and the sealing property at the time of hose piping are excellent.

Next, the present invention will be described in detail.

The fuel hose of the present invention has two configurations. First, an example of two forms will be shown. This fuel hose is a multi-layered hose (first fuel hose) having a tubular inner layer made of fluororesin and an outer layer made of a special polyamide resin on the outer peripheral surface of the tubular inner layer.

The fluororesin which is the material for forming the tubular inner layer is not particularly limited, and those generally used in the field of fuel hoses can be used. Among such fluororesins, those having a low vinylidene fluoride content are preferable. This is because when the content of vinylidene fluoride in the fluororesin, which is the material for forming the tubular inner layer, is high,
This is because corrosion may occur due to an amine compound that is added as an additive (detergent, etc.) to fuel such as gasoline. As such a resin having a low vinylidene fluoride content, for example, a fluororesin containing no vinylidene fluoride, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) , Tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE) and the like. Then, as the fluororesin having a low vinylidene fluoride content (60 mol% or less), vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene- Examples thereof include a hexafluoropropylene copolymer and a graft polymer of polyvinylidene fluoride and a vinylidene fluoride-hexafluoropropylene copolymer. These can be used alone or in combination of two or more. It is also possible to use a mixture of these fluororesins with an acrylic elastomer. Among the above-mentioned fluororesins, ETFE, PTFE, FE are preferable because those having a low vinylidene fluoride content are preferable.
P, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer (molar ratio = 2/6/2)
And the like are preferably used.

Further, it is preferable to use a fluororesin having a flexural modulus of 100 to 1700 MPa. This is because a fluororesin generally has a high rigidity, and a resin having a small content of vinylidene fluoride as described above has a strong tendency. A fuel hose made of such a high-rigidity fluororesin is difficult to mount along an arbitrary shape, for example, when it is connected to an engine room of an automobile, or a pipe to be fitted with this fuel hose. This is because there is a possibility that the fitting property with the like will deteriorate and the sealing property will deteriorate. However, such a problem can be solved by using a fluororesin having a bending elastic modulus in the above specific range. A more preferable range of the bending elastic modulus is 100 to 1300 MPa. Within this range, the properties such as the attaching property of the fuel hose and the sealing property are remarkably improved.

Next, the material for forming the outer layer directly laminated on the outer peripheral surface of the tubular inner layer is a resin composition comprising a polyamide resin mixed with a special additive.

The polyamide resin is not particularly limited, and examples thereof include those conventionally used in the field of fuel hoses. For example, nylon 6, nylon 66, nylon 610, nylon 612,
Nylon 11, nylon 12, or copolymers or mixtures thereof are preferably used. For the purpose of imparting flexibility, it is also possible to use a mixture of the above polyamide resin with a plasticizer or an elastomer, or a copolymer of the above polyamide resin with a polyether or polyester.

The polyamide resin is blended with the following component (A) as a special additive.

(A) At least one of an oxide of a metal belonging to Group II of the periodic table and a hydroxide of a metal belonging to Group II of the periodic table.

Among the above-mentioned component (A), magnesium oxide (Mg oxide) is an oxide of a metal belonging to Group II of the periodic table.
O), calcium oxide (CaO), zinc oxide (Zn)
O), beryllium oxide (BeO) and the like. These may be used alone or in combination of two or more. Among them, it is particularly preferable to use magnesium oxide (MgO) because of its high reaction efficiency.

Among the above components (A), hydroxides of metals belonging to Group II of the periodic table include calcium hydroxide [Ca (OH) ₂ ] and magnesium hydroxide [Mg].
(OH) ₂ ], zinc hydroxide [Zn (OH) ₂ ], beryllium hydroxide [α-Be (OH) ₂ , β-Be (O
H) ₂ ] and the like. These may be used alone or in combination of two or more. Among them, calcium hydroxide [Ca (OH) ₂ ] is particularly preferable because of its high reaction efficiency.

The mixing ratio of at least one of the oxide of the metal belonging to Group II of the periodic table and the hydroxide of the metal belonging to Group II of the periodic table [component (A)] is 100 weight% of polyamide resin. 2 for each part (hereinafter abbreviated as "part")
It is preferably set to a ratio of -20 parts, particularly preferably 4-15 parts. That is, when the blending ratio of the component (A) is less than 2 parts, the adhesiveness with the fluororesin which is a material for forming the inner layer becomes poor, and when it exceeds 20 parts, the polyamide resin composition is formed. This is because the mechanical strength of the outer layer is poor.

Further, either one of the fluororesin forming the tubular inner layer and the polyamide resin containing a special additive forming the outer layer is used as a fuel (gasoline, etc.).
Conductivity is preferably imparted for the purpose of releasing static electricity generated when the water flows inside the hose. To give conductivity to the above fluororesin or the above polyamide resin,
For example, the purpose can be achieved by blending a conductive agent. Examples of the conductive agent include carbon black and fine stainless fibers. And
The mixing ratio of the conductive agent is preferably set in the range of 0.5 to 16 parts with respect to 100 parts of the fluororesin or 100 parts of the polyamide resin. When the conductive agent is blended in this range, the volume resistivity of the layer provided with conductivity of the obtained fuel hose becomes 10 ¹⁰ Ω · cm or less, and the generated static electricity can be discharged to the outside of the hose and escaped. Become. As a result, it is possible to prevent accidents such as ignition of fuel due to static electricity.

In the present invention, the adhesion mechanism between the fluororesin tubular inner layer and the polyamide resin composition outer layer is considered to be as follows. That is, in the process of forming a laminate of the fluororesin inner layer and the polyamide resin composition outer layer, at the resin interface between them, the release of fluorine atoms from the molecular skeleton of the fluororesin and the formation of double bonds occur. Due to the formation of the double bond due to the elimination of the fluorine atom, an adhesive force is generated from the reaction action of the double bond and the laminated outer layer of the polyamide resin composition. HF, which is considered to be generated by the detachment of the fluororesin from the molecular skeleton
Is neutralized by reacting with a compound generally called an acid acceptor. Therefore, by keeping the HF concentration during the reaction below a certain amount, the detachment of fluorine molecules is promoted. The oxides of metals belonging to Group II of the periodic table and the hydroxides of metals belonging to Group II of the periodic table have such an acid accepting action. Therefore, the released fluorine atom is
The above metal oxide contained in the polyamide resin composition,
Stabilizes by reacting with metal hydroxide. With this stabilization,
Furthermore, while the defluorination reaction proceeds in the fluororesin, the double bond generated in the molecular skeleton interacts with the polyamide resin, and the effect of improving the adhesive strength at the interface can be obtained.

The above-mentioned polyamide resin is generally compounded with at least one of an oxide of a metal belonging to Group II of the periodic table and a hydroxide of a metal belonging to Group II of the periodic table [component (A)]. A different resin kneader is used, and the resin composition is obtained by kneading. Among the above resin kneaders,
A twin-screw kneading extruder is preferably used.

A polyamide resin (resin composition) containing such a special additive as described above has a unique advantage of being excellent in adhesiveness with a fluororesin, and has chemical resistance, heat resistance and abrasion resistance. It also has the original characteristics of polyamide resin such as moldability. Therefore, this resin composition can be used not only for the production of the fuel hose of the present invention but also for a resin product which needs to be produced by adhering a fluororesin and a polyamide resin. This makes it possible to improve the production efficiency of the resin product produced by adhering the fluororesin and the polyamide resin, and contribute to cost reduction.

The fuel hose of the present invention can be manufactured without performing the adhesive treatment or the adhesive treatment, but may be produced by using these treatments together. When used in combination with these treatments, it is possible to obtain a fuel hose with even better structural strength.

Next, the production of the first fuel hose will be described.

The first fuel hose is made of the above material, for example, as follows. A fluororesin (which is mixed with a conductive agent as necessary) and a polyamide resin which is blended with the above-mentioned special additive (which is blended with a conductive agent as needed) are prepared. Then, using a two-layer extruder equipped with a two-layer crosshead, these resins are coextruded with the fluororesin and the polyamide resin under the conditions of 220 to 300 ° C., preferably 250 to 300 ° C. A polyamide resin outer layer is directly laminated on the outer peripheral surface of the resin inner layer. As described above, the polyamide resin firmly adheres to the fluororesin during this extrusion molding. The adhesive force between the two resin layers is sufficient as a fuel hose within the range of 1 to 2 N / mm. In the production of the first fuel hose, heat treatment may be performed on the hose after the coextrusion molding. By this heat treatment, the adhesion between the fluororesin tubular inner layer and the polyamide resin outer layer is further strengthened. The condition of this heat treatment is usually 100 to 180 ° C. × 1.
0 to 60 minutes, preferably 120 to 160 ° C x 30 to 60
Minutes. In this way, as shown in FIG. 1, the fuel hose 1 including the fluororesin tubular inner layer 2 and the polyamide resin outer layer 3 directly laminated on the outer peripheral surface of the tubular inner layer 2 (first Fuel hose).
In the fuel hose 1 having the two-layer structure, the thickness of the tubular inner layer 2 is usually set in the range of 0.05 to 1.0 mm, preferably 0.1 to 0.5 mm. In addition, the outer layer 3
Is usually set in the range of 0.5 to 4.0 mm, preferably 0.5 to 2.0 mm.

The first fuel hose is not limited to the one having the two-layer structure described above, and a reinforcing thread layer is formed by using a reinforcing thread on the outer periphery of the outer layer 3 made of polyamide resin, or rubber or rubber is used. A reinforcing layer and a skin layer made of a flexible resin are formed, 3
A fuel hose having a multi-layer structure of more than one layer may be used.

The fuel hose having the above-mentioned multi-layer structure is shown in FIG.
The outer layer 3 made of polyamide resin and having the reinforcing layer 4 formed on the outer peripheral surface thereof as shown in FIG. In the figure,
The same parts as those in FIG. 1 are designated by the same reference numerals. By forming the reinforcing layer 4, flame resistance and chipping resistance are provided in addition to the basic characteristics such as sour gasoline resistance provided in the fuel hose having the two-layer structure. The reinforcing layer 4 is formed using rubber or a soft resin, and examples of the rubber include chlorosulfonated polyethylene rubber (CSM), chloroprene rubber (CR),
Acrylonitrile-polyvinyl chloride mixture (NBR
PVC), epichlorohydrin rubber (CO, ECO),
Examples thereof include ethylene propylene rubber (EPM or EPDM), which may be used alone or in combination of two or more kinds. Among these, because of its flame resistance and ozone resistance, CS
M, NBR / PVC, CO, ECO, EPM, EPDM
Is preferred. Examples of the soft resin include urethane-based, olefin-based, nitrile-based, and amide-based thermoplastic elastomers. Among these, it is preferable to use an amide type thermoplastic elastomer for the reason of weather resistance. The reinforcing layer 4 is formed, for example, by extruding the reinforcing layer 4 at the same time when the tubular inner layer 2 and the outer layer 3 are extrusion-molded using an extrusion molding machine, and then heat-vulcanizing in the same manner as above. You can This vulcanization condition is usually 150 to 180 ° C. × 20 to 60 minutes. The thickness of the reinforcing layer 4 is usually 0.5 to 5.
It is set to a range of 0 mm, preferably 0.5 to 3.0 mm.

Further, in the fuel hose having the above-mentioned multi-layer structure, as the fuel hose having the reinforcing thread layer formed thereon, as shown in FIG. 3, the outer layer 3 made of polyamide resin is provided on the outer periphery of the outer layer 3 with the reinforcing thread layer 5 interposed therebetween. A fuel hose having a four-layer structure in which is formed. As described above, when the reinforcing thread layer 5 is formed, the pressure resistance of the fuel hose is improved. As the reinforcing thread layer 5, a thread made of a natural material such as hemp or cotton, a synthetic thread such as a polyester thread or a vinylon thread, or a metal thread such as a wire is used. Of these, synthetic yarns such as polyester yarn and vinylon yarn are preferable because of their strength and light weight.
This reinforcing thread layer is used after producing a two-layer fuel hose,
It can be formed by using a braiding machine. Then, the outer skin layer 6 is formed on the outer periphery of the reinforcing yarn layer 5 by an extruder.
The fuel hose having the four-layer structure shown in FIG. 3 can be manufactured by forming the. The outer skin layer 6 is formed of the same rubber or soft resin as the reinforcing layer 4. The thickness of the outer skin layer 6 is usually 0.5 to 5.0 mm.
Is set, preferably in the range of 0.5 to 3.0 mm.

As another example of the first fuel hose, as shown in FIG. 4, in addition to the tubular inner layer 2 made of fluororesin and the outer layer 3 made of polyamide resin, a reinforcing layer 4, a reinforcing yarn layer 5, A five-layer fuel hose composed of the outer skin layer 6 may also be used. The fuel hose having such a combination has all the characteristics of flame resistance, chipping resistance, and pressure resistance. Such a fuel hose having a five-layer structure can be produced by combining the above-mentioned press molding machine and braiding machine. The thickness of each of the reinforcing layer 4, the reinforcing yarn layer 5, and the outer skin layer 6 is also the same as that of the fuel hose having the three-layer structure and the four-layer structure.

Next, other than the above-mentioned multi-layer fuel hose (first fuel hose) having a fluororesin inner layer and a polyamide resin outer layer formed on the outer peripheral surface of this inner layer The fuel hose (second fuel hose) will be described.

This fuel hose (second fuel hose) is
The hose has a multi-layer structure including a tubular inner layer made of a special polyamide resin and an outer layer made of a fluororesin on the outer peripheral surface of the tubular inner layer. That is, this second fuel hose corresponds to the above-mentioned fuel hose (first fuel hose).
In the above configuration (a fluororesin inner layer and a polyamide resin outer layer formed on the outer peripheral surface of the inner layer), the inner hose forming material and the outer layer forming material are used in reverse.

In this fuel hose (second fuel hose), a resin composition comprising a polyamide resin mixed with a special additive which is a material for forming the tubular inner layer, and directly laminated on the outer peripheral surface of the tubular inner layer. As the fluororesin, which is the material for forming the outer layer, the same material as that of the above-described fuel hose (first fuel hose) is used.

Similar to the first fuel hose, it is generated when fuel (gasoline, etc.) flows inside the hose in either one of the polyamide resin tubular inner layer and the fluororesin outer layer. Conductivity may be imparted for the purpose of releasing static electricity. As the material for imparting conductivity to the fluororesin or the polyamide resin, the same material as that of the fuel hose described above is used, and the compounding amount of the material is set similarly to that of the fuel hose described above.

The fuel hose (second fuel hose) is manufactured in the same manner as the above-mentioned fuel hose (first fuel hose). That is, using a two-layer extruder equipped with a two-layer crosshead, the fluororesin and the polyamide resin are coextruded under the same conditions as described above, and the fluororesin outer layer is directly laminated on the outer peripheral surface of the polyamide resin inner layer. Form. In this way, a fuel hose (second fuel hose) having a structure including the fluororesin inner layer and the polyamide resin outer layer formed on the outer peripheral surface of the inner layer is manufactured.

Therefore, in the fuel hose thus produced (second fuel hose), the adhesion mechanism between the tubular inner layer made of the polyamide resin composition and the outer layer made of the fluororesin is, of course, the same as the first fuel described above. Think of it like a hose.

Regarding the thickness of each of the fuel hoses (second fuel hoses), the thickness of the polyamide resin tubular inner layer is usually 0.5 to 5 as in the case of the above-described fuel hoses (first fuel hoses). It is set to a range of 4.0 mm, preferably 0.5 to 2.0 mm. The thickness of the outer layer is usually set in the range of 0.05 to 1.0 mm, preferably 0.1 to 0.5 mm.

The fuel hose (second fuel hose) is not limited to the one having the two-layer structure described above, but like the first fuel hose described above, the outer periphery of the fluororesin outer layer is reinforced. A fuel hose having a multi-layered structure of three or more layers in which a reinforcing thread layer is formed by using a thread, or a reinforcing layer or an outer skin layer using rubber or a flexible resin is formed may be used.

As the fuel hose (second fuel hose) having such a multi-layer structure, there can be mentioned one having a reinforcing layer formed on the outer peripheral surface, as in the case of the fuel hose (first fuel hose) described above. . In this case, the material, the thickness of the reinforcing layer, the manufacturing conditions, etc. are the same as those of the fuel hose described above.

As the fuel hose having the above-mentioned multilayer structure,
Examples of the fuel hose having a reinforcing thread layer include a fuel hose having a four-layer structure in which an outer skin layer is formed on the outer circumference of a fluororesin outer layer via a reinforcing thread layer, like the fuel hose described above. The material of the reinforcing thread layer may be the same as described above, and the thickness of the reinforcing thread layer may be set in the same manner as in the fuel hose having the above-mentioned multilayer structure.

As another example of the second fuel hose, similar to the first fuel hose, in addition to the tubular inner layer made of polyamide resin and the outer layer made of fluororesin, a reinforcing layer, a reinforcing thread layer and an outer layer are provided. Another example is a fuel hose having a five-layer structure made of a skin layer. Fuel hoses with such a combination are flame resistant,
It has all the characteristics of chipping resistance and pressure resistance. Such a fuel hose having a five-layer structure can be produced by combining the above-mentioned press molding machine and braiding machine. The thickness of each of the reinforcing layer, the reinforcing yarn layer, and the outer skin layer is the same as that of the fuel hose having the three-layer structure and the four-layer structure.

Next, examples will be described together with comparative examples.

(1) First, a first fuel hose having a polyamide resin outer layer formed on the outer peripheral surface of a fluororesin tubular inner layer will be described.

[0049]

Example 1 First, a fuel hose having a two-layer structure consisting of a fluororesin inner layer and a polyamide resin outer layer was prepared using the materials and conditions shown in Table 1 below. That is, a polyamide resin (nylon 11) is mixed with a plasticizer and magnesium oxide, and a Labo Plastomill (model 80C10
0, manufactured by Toyo Seiki Co., Ltd.) at 230 ° C. to prepare a resin composition for forming an outer layer. This outer layer forming resin composition and the inner layer forming fluororesin (Neoflon EP52
1, manufactured by Daikin Co., Ltd., and a two-layer resin co-extruder having a crosshead structure are used to simultaneously extrude an inner layer and an outer layer at a temperature of 300 ° C. to form a two-layer fuel hose (inner diameter: 6 mm, A total thickness of 1 mm) was produced.

Next, with the materials and conditions shown in Table 1 below, a reinforcing layer, a reinforcing yarn layer, and an outer skin layer were formed on the outer periphery of the above-mentioned two-layer structure hose by using an extruder and a braiding machine. A fuel hose having a five-layer structure as shown in (4) was produced. The fiber reinforcement layer was formed by braiding. When forming the reinforcing layer and the outer skin layer, vulcanization was performed under the conditions of 150 ° C. × 30 minutes.

[0051]

Examples 2 to 22 and Comparative Examples 1 to 4 The same operations as in Example 1 were carried out using the materials and conditions shown in Tables 1 to 7 below.
A hose having a two-layer structure was produced. And Examples 13-1
No. 7 was a fuel hose having a two-layer structure as it was. In addition, in Examples 18 to 22, the reinforcing layer was formed by the above-described method to fabricate a three-layer fuel hose. Other examples,
In the comparative example, a fuel hose having a five-layer structure was produced in the same manner as in Example 1 above. The fiber reinforcement layer was formed by braiding. In the kneading step of the polyamide resin, when nylon 6 is used, the temperature condition is 270 ° C.
Set to.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

[Table 5]

[0057]

[Table 6]

[0058]

[Table 7]

[0059]

Example 23 Two parts of calcium oxide were used instead of magnesium oxide. Except for this, as shown in Table 8 below, a fuel hose having a five-layer structure (inner diameter 6.0 mm) was produced in the same manner as in Example 2.

[0060]

Example 24 20 parts of calcium oxide was used in place of magnesium oxide. Except for this, as shown in Table 8 below, a fuel hose having a five-layer structure (inner diameter 6.0 mm) was produced in the same manner as in Example 2.

[0061]

Example 25 2 parts of magnesium hydroxide was used instead of magnesium oxide. Except for this, as shown in Table 8 below, a fuel hose having a five-layer structure (inner diameter 6.0 mm) was produced in the same manner as in Example 2.

[0062]

Example 26 20 parts of magnesium hydroxide was used instead of magnesium oxide. Except for this, as shown in Table 8 below, a fuel hose having a five-layer structure (inner diameter 6.0 mm) was produced in the same manner as in Example 2.

[0063]

[Example 27] Instead of magnesium oxide, 10 parts of calcium oxide and 10 parts of magnesium hydroxide were used. Except for this, as shown in Table 8 below, a fuel hose having a five-layer structure (inner diameter 6.0 mm) was produced in the same manner as in Example 2.

[0064]

[Table 8]

[0065]

Examples 28 to 32 Next, a fuel hose having conductivity imparted to either the inner layer or the outer layer was prepared by blending carbon black with either the tubular inner layer forming material or the outer layer forming material. did. That is, with the materials and conditions shown in Table 9 below, Example 1
A hose having a two-layer structure was produced by performing the same operation as described in. Then, a fuel hose having a five-layer structure was produced in the same manner as in Example 1. The fiber reinforcement layer was formed by braiding. The volume resistivity of the layer to which conductivity is given is J
It was measured according to IS K 6911.

[0066]

[Table 9]

(2) Next, a fuel hose (second fuel hose) having a fluororesin outer layer formed on the outer peripheral surface of a polyamide resin tubular inner layer will be described.

[0068]

Example 33 First, a fuel hose having a two-layer structure consisting of a polyamide resin inner layer and a fluororesin outer layer was prepared according to the materials and conditions shown in Table 10 below. That is, a polyamide resin (nylon 11) is mixed with a plasticizer and magnesium oxide, and a Labo Plastomill (model 80
C100, manufactured by Toyo Seiki Co., Ltd.) was kneaded at 230 ° C. to prepare an inner layer forming resin composition. The resin composition for forming the inner layer and the fluororesin for forming the outer layer (Neoflon EP
521, manufactured by Daikin Co., Ltd., and a two-layer coextruder for resin having a crosshead structure, the inner layer and the outer layer are simultaneously extruded at a temperature of 300 ° C. to form a two-layer fuel hose (inner diameter: 6 mm, A total thickness of 1 mm) was produced.

Next, using the materials and conditions shown in Table 10 below, a reinforcing layer, a reinforcing yarn layer, and an outer skin layer were formed on the outer periphery of the above-mentioned two-layer structure hose by using an extruder and a braiding machine.
A fuel hose having a five-layer structure as shown in (in this case, the inner layer is made of polyamide resin and the outer layer is made of fluororesin) was produced. The fiber reinforcement layer was formed by braiding. In addition, at the time of forming the reinforcing layer and the outer skin layer,
Vulcanization was performed under the conditions of 0 ° C. for 30 minutes.

[0070]

[Examples 34 to 54, Comparative Examples 5 to 8] The same operations as in Example 33 were carried out using the materials and conditions shown in Tables 10 to 16 described below to produce hoses having a two-layer structure. Then, Examples 45 to 49 were used as they were as the two-layer fuel hose.
In addition, in Examples 50 to 54, the reinforcing layer was formed by the above-described method to fabricate a three-layer fuel hose. In the other Examples and Comparative Examples, a fuel hose having a five-layer structure was produced in the same manner as in Example 33 above. The fiber reinforcement layer was formed by braiding. In the kneading step of the polyamide resin, when nylon 6 was used, the temperature condition was set to 270 ° C.

[0071]

[Table 10]

[0072]

[Table 11]

[0073]

[Table 12]

[0074]

[Table 13]

[0075]

[Table 14]

[0076]

[Table 15]

[0077]

[Table 16]

[0078]

Example 55 2 parts of calcium oxide was used instead of magnesium oxide. Other than that, as shown in Table 17 described later, a five-layer fuel hose (inner diameter 6.0 mm) was produced in the same manner as in Example 34.

[0079]

Example 56 20 parts of calcium oxide was used instead of magnesium oxide. Other than that, as shown in Table 17 described later, a five-layer fuel hose (inner diameter 6.0 mm) was produced in the same manner as in Example 34.

[0080]

Example 57 2 parts of magnesium hydroxide was used instead of magnesium oxide. Other than that, as shown in Table 17 described later, a five-layer fuel hose (inner diameter 6.0 mm) was produced in the same manner as in Example 34.

[0081]

Example 58 20 parts of magnesium hydroxide was used instead of magnesium oxide. Other than that, as shown in Table 17 described later, a five-layer fuel hose (inner diameter 6.0 mm) was produced in the same manner as in Example 34.

[0082]

[Example 59] Instead of magnesium oxide, 10 parts of calcium oxide and 10 parts of magnesium hydroxide were used. Other than that, as shown in Table 17 described later, a five-layer fuel hose (inner diameter 6.0 mm) was produced in the same manner as in Example 34.

[0083]

[Table 17]

[0084]

Examples 60 to 64 Next, a fuel hose having conductivity imparted to either the inner layer or the outer layer was prepared by blending carbon black with either the tubular inner layer forming material or the outer layer forming material. did. That is, the same operation as in Example 33 was performed under the materials and conditions shown in Table 18 below to produce a hose having a two-layer structure. Then, a fuel hose having a five-layer structure was produced in the same manner as in Example 33. The fiber reinforcement layer was formed by braiding. The volume resistivity of the layer provided with the conductivity was measured according to JIS K 6911.

[0085]

[Table 18]

Regarding the fuel hoses of the example product and the comparative example product thus obtained, the interlayer adhesive force (adhesiveness) between the inner layer and the outer layer, fuel permeability, sealability, flexibility and mechanical strength ( Tensile strength, elongation)
evaluated. The results are also shown in Tables 19 to 30 below. The above characteristics were measured according to the evaluation methods shown below.

[Adhesion between Inner Layer and Outer Layer] The adhesion test is as follows.
It was performed according to JIS K 6301. That is,
As shown in FIG. 6, the two-layer hose of the example product and the comparative example product was cut into a ring shape so as to have a length of 10 mm, and further cut in the longitudinal direction to obtain a test sample. Then, the inner layer 11 and the outer layer 12 were peeled from the cut surface of this test sample, the peeled ends were fixed to a gripping jig of a tensile tester, and a tensile test was performed at a pulling speed of 25 mm / min. The peel strength between the two layers was determined from the load, and the adhesiveness was evaluated. In the figure, L represents a length of the test sample of 10 mm.

[Fuel Permeability] First, two types of test mixed gasolines A and B were prepared. Mixed gasoline A is methyl t
The mixed gasoline of ert-butyl ether (MTBE) / regular gasoline = 15/85 (mixing ratio by weight) and the mixed gasoline B is ethanol / regular gasoline = 10/90 (mixing ratio by volume). Then, each of the mixed gasolines A and B was sealed in a fuel hose and left at a temperature of 40 ° C. for 168 hours. Then, after replacing with new mixed gasoline, the mixture was left at 40 ° C. for 72 hours, and the permeation amount per day was calculated from the weight change before and after the leaving.

[Sealability] Sealing performance after a fuel hose is externally fitted to the metal pipe 20 having the shape shown in FIG. 7 and subjected to heat deterioration (120 ° C. × 288 hours) at room temperature (25 ° C.) It was confirmed. The condition was 0.49 MPa, and it was confirmed whether fuel leaked at this time.

[Flexibility] As shown in FIG. 8, a loop was formed by using a fuel hose 21 having a length of 1 m, and the intersection thereof was held by hand, and the fuel hose 21 was pulled in the direction of the arrow. Then, the diameter of the ring in the R portion at the time of kinking was measured by further reducing the diameter of the ring.

[Mechanical Strength] Tensile strength and elongation of a polyamide resin outer layer or inner layer of the two-layer fuel hose of each Example product and Comparative Example product were examined. The tensile strength and elongation were measured according to ASTM D638.

[0092]

[Table 19]

[0093]

[Table 20]

[0094]

[Table 21]

[0095]

[Table 22]

[0096]

[Table 23]

[0097]

[Table 24]

[0098]

[Table 25]

[0099]

[Table 26]

[0100]

[Table 27]

[0101]

[Table 28]

[0102]

[Table 29]

[0103]

[Table 30]

From Tables 19 to 30 above, it can be seen that the fuel hoses of all the examples have excellent adhesiveness between the inner layer and the outer layer. From this, it can be said that the fuel hose of the present invention has excellent structural strength even if it is not subjected to an adhesive treatment or an adhesive treatment. Further, in the fuel hoses of all the example products, the polyamide resin outer layer or the polyamide resin inner layer was excellent in mechanical strength of the polyamide resin layer because the compounding ratio of the special additive was within the proper range. The fuel hoses of all the examples were excellent in sealing property and flexibility because the bending elastic modulus of the fluororesin inner layer or the fluororesin outer layer was set in an appropriate range. Further, the fuel hoses of all the examples were excellent in fuel permeability. Then, the fuel hoses of all the example products could be easily manufactured without going through complicated steps.

On the other hand, from Tables 29 and 30 above, in the fuel hoses of Comparative Examples 1 and 5, the inner layer and the outer layer did not adhere because the polyamide resin did not contain a special additive. Further, in the fuel hoses of Comparative Examples 2, 4, 6 and 8, since the blending ratio of the special additive exceeds the proper range, the machine of the polyamide resin outer layer or the polyamide resin inner layer is used. Was not strong enough. And
In the fuel hoses of Comparative Examples 3 and 7, the blending ratio of the special additive was too small, and the adhesion between the inner layer and the outer layer was extremely poor.

[0106]

As described above, the fuel hose of the present invention is
An outer layer is formed on the outer peripheral surface of the fluororesin tubular inner layer by using a polyamide resin mixed with a special additive [component (A)]. Polyamide resin containing this special additive does not have to undergo the usual heat vulcanization process without the need to perform adhesion treatment such as plasma treatment or subsequent adhesion treatment using the adhesive on the fluororesin. It firmly adheres to the fluororesin. Therefore, the fuel hose of the present invention can be manufactured without deteriorating the original performance by omitting the two steps of the bonding treatment step and the bonding step using an adhesive, which are required in the conventional fuel hose manufacturing. Become. Then, from the viewpoint that the polyamide resin layer using the special polyamide resin and the fluororesin layer have a strong adhesiveness, the outer surface of the tubular inner layer made of the special polyamide resin is a fluororesin outer layer. The fuel hose having the formed structure also has the same effect as described above. As a result, the fuel hose of the present invention maintains the same high performance as the conventional product and is extremely low in cost as compared with the conventional product.

In particular, by imparting conductivity to either one of the tubular inner layer and the outer layer made of the above-mentioned forming material, the occurrence of a vehicle fire due to sparks due to static electricity generated by the flow of fuel in the hose is prevented. It becomes possible to prevent it.

In the fuel hose of the present invention, if the tubular inner layer is formed by using a fluororesin having a bending elastic modulus within a specific range, the flexibility of the fuel hose becomes excellent. Since such a fuel hose can be piped along any shape, it can be easily attached to a place having a complicated piping structure such as an engine room of an automobile. Further, since such a fuel hose has excellent sealing properties and is firmly fitted and connected to another piping member such as a metal pipe, even if the fuel is fed under high pressure, the fitting part (connecting part) No fuel leaks or accidents such as disconnection of the fuel hose will occur. Furthermore, the polyamide resin (resin composition) blended with the special additive used in the fuel hose of the present invention is not only excellent in adhesiveness with the fluororesin, but also has chemical resistance, heat resistance, and chemical resistance originally possessed by the polyamide resin. It also has excellent properties such as wear resistance and formability. For this reason, this resin composition is not limited to the use of a fuel hose, and if it is used for other laminated products such as a sheet-like product composed of a fluororesin layer and a polyamide resin layer, a high-performance laminated product is obtained. Can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a fuel hose (first fuel hose) of the present invention.

FIG. 2 is an explanatory view showing another configuration of the fuel hose (first fuel hose) of the present invention.

FIG. 3 is an explanatory diagram showing another configuration of the fuel hose (first fuel hose) of the present invention.

FIG. 4 is an explanatory view showing another configuration of the fuel hose (first fuel hose) of the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a conventional fuel hose.

FIG. 6 is an explanatory diagram of a test sample used in the adhesion test.

FIG. 7 is an explanatory diagram of a metal pipe used when testing the sealability.

FIG. 8 is an explanatory diagram showing a state in which kink property is checked.

[Brief description of reference numerals]

 1 Fuel hose 2 Tubular inner layer 3 Outer layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location C08K 3/22 F16L 11/04 11/08 B (72) Inventor Tsutomu Kodama Komaki City, Aichi Prefecture Sotoyama character Utsutsu 3600 Tokai Rubber Industry Co., Ltd.

Claims (13)

[Claims] 1. A fuel hose comprising a tubular inner layer and an outer layer directly laminated on the outer peripheral surface of the tubular inner layer, the fuel hose comprising:
The tubular inner layer is formed of a fluororesin, the outer layer is formed of a polyamide resin containing the following component (A), and the content ratio of the component (A) is 100 parts by weight of the polyamide resin. The fuel hose is characterized by being set within a range of 2 to 20 parts by weight. (A) At least one of an oxide of a metal belonging to Group II of the periodic table and a hydroxide of a metal belonging to Group II of the periodic table. 2. The fuel hose according to claim 1, wherein conductivity is imparted to either one of the tubular inner layer and the outer layer. 3. The fuel hose according to claim 1, wherein the oxide of the metal belonging to Group II of the periodic table is magnesium oxide. 4. The fuel hose according to claim 1, wherein the hydroxide of the metal belonging to Group II of the periodic table is calcium hydroxide. 5. The fuel hose according to claim 1, wherein the tubular inner layer formed of a fluororesin has a bending elastic modulus in the range of 100 to 1700 MPa. 6. A fuel hose comprising a tubular inner layer and an outer layer directly laminated on the outer peripheral surface of the tubular inner layer, the fuel hose comprising:
The tubular inner layer is formed of a polyamide resin containing the following component (A), the outer layer is formed of a fluororesin, and the content ratio of the component (A) is 100 parts by weight of the polyamide resin. A fuel hose characterized by being set in a range of 2 to 20 parts by weight. (A) At least one of an oxide of a metal belonging to Group II of the periodic table and a hydroxide of a metal belonging to Group II of the periodic table. 7. The fuel hose according to claim 6, wherein conductivity is imparted to either one of the tubular inner layer and the outer layer. 8. The fuel hose according to claim 6 or 7, wherein the oxide of the metal belonging to Group II of the periodic table is magnesium oxide. 9. The fuel hose according to claim 6, wherein the hydroxide of the metal belonging to Group II of the periodic table is calcium hydroxide. 10. The fuel hose according to claim 6, wherein the flexural modulus of the outer layer formed of the fluororesin is in the range of 100 to 1700 MPa. 11. The polyamide resin is blended with the following component (A), and the blending ratio of the component (A) is set within the range of 2 to 20 parts by weight with respect to 100 parts by weight of the polyamide resin. A resin composition comprising: (A) At least one of an oxide of a metal belonging to Group II of the periodic table and a hydroxide of a metal belonging to Group II of the periodic table. 12. The resin composition according to claim 11, wherein the oxide of the metal belonging to Group II of the periodic table is magnesium oxide. 13. The hydroxide of a metal belonging to Group II of the periodic table is calcium hydroxide.
The resin composition according to 2.