JP2820003B2 - Automotive resin hose and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin hose for an automobile used for a fuel pipe or the like of an automobile and a method for producing the same.

[0002]

2. Description of the Related Art Fluorine-based resins such as ethylene-tetrafluoroethylene copolymer (ETFE) have excellent corrosion resistance to chemicals and gasoline, and are therefore awarded as constituent materials of resin hoses used for fuel pipes of automobiles. Have been used. FIG. 3 shows such an automotive resin hose.
As shown in FIG. 2, there is known a hose having a two-layer structure in which an outer layer 12 made of a polyamide-based thermoplastic resin is laminated on the outer periphery of an inner layer 11 made of a fluorine-based resin. When manufacturing this hose, the fluorine resin and the polyamide thermoplastic resin are bonded using a resin adhesive such as a urethane adhesive, but before the bonding process, the surface of the fluorine resin is Special bonding pretreatment is performed. This is because the fluorine-based resin is hardly adherent, so that a treatment with an adhesive alone does not provide sufficient adhesive strength, making it difficult to obtain a practical hose. As this pretreatment, there is a metal sodium complex solution treatment method. As an example of this pretreatment method, when producing the above-described hose having a two-layer structure, there is a treatment method in which a cylindrical inner layer made of a fluororesin is immersed in a metal sodium complex solution, then pulled up, washed and dried. . According to this pretreatment method, since the outer peripheral surface of the inner layer made of the fluororesin is activated, it is possible to adhere to the outer layer made of the thermoplastic thermoplastic resin. However, since steps such as immersion and washing are required, there is a problem that the steps are long and complicated as a whole.
There are problems such as safety to the human body. The waste liquid generated during the above washing is also harmful and requires large-scale equipment to make it non-toxic, which increases the equipment cost. Therefore, the hose obtained by this method has a problem in that it has a problem in safety at the time of production and also has a problem in that the cost is high.

[0003]

On the other hand, as a pretreatment method other than the above, a corona discharge treatment method has been proposed and partially implemented. This pretreatment method is a method in which the number of steps is small and there is no problem in safety as compared with the above-mentioned method using a metal sodium complex solution. In addition, since special equipment and devices required for other discharge treatments such as a glow discharge treatment are not required, this is a method capable of keeping equipment costs low.
However, this corona discharge treatment method has a disadvantage that the effect of the pre-adhesion treatment is lower than the method using a metal sodium complex solution. Therefore, the resin hose for automobiles manufactured by this method has low adhesive strength and has a problem in practicality.

The present invention has been made in view of such circumstances, and provides a low-cost automotive resin hose having excellent adhesive strength and a method of manufacturing a highly efficient automotive resin hose having excellent safety. Its purpose is to

[0005]

In order to achieve the above object, the present invention relates to a resin hose for automobiles in which an outer layer made of a thermoplastic thermoplastic resin is laminated around an inner layer made of a fluororesin, The resin hose for automobiles in which the outer peripheral surface of the fluororesin inner layer is formed in a rough surface and an aminosilane-based coupling agent treatment layer is formed on the rough surface,
A method of manufacturing an automotive resin hose in which a polyamide-based thermoplastic resin outer layer is laminated and formed on the outer periphery of a fluorine-based resin inner layer, wherein the fluorine-based resin inner layer is formed by extrusion molding. After performing a pre-adhesion treatment by corona discharge treatment on the outer peripheral surface of the inner layer made of the fluorine-based resin, a treatment layer is formed by an aminosilane-based coupling agent treatment, and a polyamide-based treatment layer is formed on the aminosilane-based coupling agent treatment layer. A second aspect of the present invention is a method of manufacturing a resin hose for an automobile in which a thermoplastic resin outer layer is formed by extrusion molding.

[0006]

In other words, the present inventors have conducted a series of studies focusing on the treatment of the outer peripheral surface of the inner layer made of a fluororesin in order to solve the above problems. As a result, when the outer peripheral surface of the fluororesin inner layer is formed on a rough surface, and a treatment layer with an aminosilane coupling agent is formed on the rough surface, the polyamide thermoplastic resin outer layer formed thereon is It has been found that, at the contact surface between the two layers, the anchoring effect is caused by being cut into the concave portion of the rough surface, and the affinity between the two layers is significantly improved. And
The present inventors have found that a hose obtained by performing these two treatments has excellent adhesive strength without using an adhesive, and arrived at the present invention. Further, the outer peripheral surface of the inner layer made of the fluorine-based resin can be roughened by corona discharge treatment which has a small number of steps and has no problem in safety. In addition, aminosilane-based coupling agent treatment can be easily performed, and there is no problem in safety. Therefore, according to the present invention, it becomes possible to impart excellent adhesive strength to a resin hose for automobiles without using an adhesive, and also in the production thereof, excellent safety and high productivity are realized. become.

Next, the present invention will be described in detail.

The automotive resin hose of the present invention is obtained by subjecting a fluororesin and a polyamide thermoplastic resin as raw materials to, for example, a corona discharge treatment in the air and a treatment with an aminosilane coupling agent. Can be made.

As the above-mentioned fluororesin, copolymers of ethylene and tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (CTFE), copolymers of ethylene and chlorotrifluoroethylene (ECTFE), copolymer of hexafluoropropylene and tetrafluoroethylene (FEP), fluorinated alkoxyethylene resin (PF
A), polytetrafluoroethylene (PTFE) and the like, which are used alone or in combination of two or more.
Among them, it is preferable to use ETFE.

[0010] A filler can be added to the fluororesin for the purpose of improving physical properties. Such fillers include titanium oxide, barium sulfate, calcium carbonate, silica, carbon black, magnesium silicate, aluminum silicate, zinc oxide, alumina, calcium sulfate, aluminum sulfate, calcium hydroxide, aluminum hydroxide, talc. , Molybdenum dioxide, whiskers, staple fibers, graphite, metal powder, silica sand, pumice powder, slate powder, mica powder, asbestos, glass spheres and the like. The mixing ratio of this filler is usually 100
It is set in the range of 0 to 30 parts by weight (hereinafter abbreviated as "part").

The above-mentioned polyamide-based thermoplastic resin is not particularly limited, and examples thereof include nylon 6, nylon 66, nylon 11, nylon 12, etc., which are excellent in abrasion resistance and the like, alone or in combination of two or more. Is done.

A plasticizer may be added to the polyamide-based thermoplastic resin in order to improve processing characteristics and flexibility. Examples of the plasticizer include sulfonamides and oxybenzoic esters. The mixing ratio of this plasticizer is usually 1% of the polyamide thermoplastic resin.
For 00 parts, it is set in the range of 0 to 20 parts. Also,
It is also possible to incorporate a filler used in the fluororesin.

The aminosilane-based coupling agent used in the above-mentioned aminosilane-based coupling agent treatment includes those represented by the following general formula (1).

[0014]

Embedded image

Specific examples of such an aminosilane-based coupling agent include γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, and N-β- (amino Ethyl)-
γ-aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane and the like. These may be used alone or as a mixture of two or more. Further, an additive such as phenol may be blended and used as a mixture mainly composed of the aminosilane-based coupling agent.

The corona discharge treatment in the atmosphere is a treatment using a high-frequency power supply. By combining the corona discharge treatment with the treatment with the aminosilane-based coupling agent, the automotive resin hose of the present invention using the above-described raw materials can be continuously manufactured, for example, as follows.
That is, first, as shown in FIG.
The mandrel 3 is supplied from the mandrel supply device 1 to the inner layer extruder 4 in a minute, and the inner layer extruder 4 extrudes the fluororesin inner layer 11 using the fluororesin. This inner layer 11 usually has an inner diameter of 5 to 50 mm,
The thickness is set in the range of 0.1 to 1 mm. Next, the mandrel 3 on which the inner layer 11 is formed passes through the water cooling zone 15 and is guided into the corona discharge treatment device 6. The inside of the processing device 6 is under general atmospheric conditions. And
Between the electrodes 7 is a processing zone, into which the mandrel 3 on which the inner layer 11 is formed is guided, and a high-frequency power source 8 is provided.
A pre-adhesion treatment by corona discharge treatment is performed on the outer peripheral surface of the inner layer 11. The conditions of this discharge processing are, for example, conditions of a frequency of 20 to 40 kHz and an output of 0.2 to 20 kW. In addition, the treatment time at this time is appropriately determined depending on conditions such as the type of the fluororesin, and is usually 1 to 6 times.
0 seconds. Then, the inner layer 11 subjected to the corona discharge treatment
Is discharged out of the processing device 6. Next, the outer peripheral surface of the inner layer 11 is subjected to an aminosilane-based coupling agent treatment by the coupling agent treatment device 16. This treatment is performed by dissolving the aminosilane-based coupling agent in a solvent such as methanol, applying the solution, and then drying the solution. The coating method is not particularly limited, but is performed by a method suitable for continuous production, such as a dipping method, a dropping method, or a spraying method. Examples of a method for drying the applied aminosilane-based coupling agent include a method such as hot-air drying. In this way, an aminosilane-based coupling agent-treated layer is formed on the outer peripheral surface of the inner layer 11.
Then, the fluororesin inner layer 1 on which this treatment layer is formed
The outer layer 1 is coated with an outer layer extruder 5 with a thickness of 0.2 to 2 mm.
The outer layer 12 made of a polyamide-based thermoplastic resin having a thickness of 2 mm is formed. Then, the mandrel 3 on which the inner layer 11 and the outer layer 12 are formed is wound by the mandrel winding machine 2.

By such a continuous process, an aminosilane-based coupling agent treatment layer 17 is formed on the outer peripheral surface of the fluororesin inner layer 11 as shown in FIG. An automobile resin hose having the plastic resin outer layer 12 formed thereon can be manufactured.
In addition, as the electrode shape, a ball electrode can be used in addition to the line electrode as shown in FIG. In the above-mentioned manufacturing method, a manufacturing method using a mandrel is described. However, the manufacturing method is not limited to this. A resin hose for an automobile can be manufactured by performing the same process without using a mandrel.

As described above, by performing the corona discharge treatment, the outer peripheral surface of the fluororesin inner layer is roughened. Then, by forming a treatment layer with an aminosilane-based coupling agent, the amino group in the coupling agent molecule shows an affinity for the polyamide-based thermoplastic resin, and the Si-O structure in the molecule is converted to the fluorine-based resin. Since it shows affinity, the affinity between the fluorine-based resin and the polyamide-based thermoplastic resin is remarkably increased, and the adhesive strength between them is excellent without using an adhesive. As described above, by combining the surface roughening treatment by corona discharge treatment and the improvement in affinity by the aminosilane-based coupling agent, it is possible to produce an automotive resin hose having excellent adhesive strength without using an adhesive. It becomes possible. This is the most important feature of the present invention.

[0019]

As described above, the resin hose for an automobile of the present invention is a resin hose for an automobile in which a polyamide-based thermoplastic resin outer layer is formed on the outer periphery of a fluorine-based resin inner layer. The outer peripheral surface of the inner layer made of a resin-based resin is formed in a rough surface, and a treatment layer using an aminosilane-based coupling agent is formed on the rough surface. In other words, on the outer peripheral surface of the roughened fluororesin inner layer, the polyamide thermoplastic resin is bonded in a state of biting into the concave portion of the rough surface, so that a high anchoring effect is generated and aminosilane is generated. The affinity of the polyamide-based thermoplastic resin outer layer with respect to the fluorine-based resin inner layer is significantly increased by the system-based coupling agent-treated layer. As a result, the resulting automotive resin hose has excellent adhesive strength without using an adhesive. Further, since no adhesive is used and a metal sodium complex solution is not required, there is no problem in safety, and special equipment such as waste liquid treatment equipment is not required. Therefore, it is possible to keep the equipment cost low. In addition, in the present invention, the surface of the fluororesin can be easily and continuously roughened by a method such as a corona discharge treatment in the atmosphere. In addition, a normal method can be applied to the formation of the aminosilane-based coupling agent-treated layer. And since the said two processes can be made into a continuous process, the said resin hose for motor vehicles can be manufactured continuously and at high speed, and productivity will improve. Therefore, according to the present invention, a resin hose for automobiles having excellent adhesive strength and corrosion resistance can be provided at low cost.

Next, examples will be described together with comparative examples.

[0021]

Examples 1 and 2 Resin hoses for automobiles made of ETFE and nylon 12 were prepared according to the above-mentioned method. That is, first, as shown in FIG. 2, the mandrel 3 is supplied from the mandrel supplying device 1 to the inner extruder 4 at a speed of 5 m / min.
Using E, an inner layer 11 having an inner diameter of 6.0 mm and a thickness of 0.25 mm was formed on the outer periphery of the mandrel 3. Next, the mandrel 3 was guided through the water cooling zone 15 into the corona discharge treatment device 6. Then, the mandrel 3 on which the ETFE inner layer 11 was formed was guided to the treatment zone between the electrodes 7, and the outer periphery of the ETFE inner layer was subjected to corona discharge treatment at a frequency of 20 kHz and an output of 0.4 kW. After this treatment, the mandrel 3 was discharged out of the corona discharge treatment device 6, and the mandrel 3 was discharged from the coupling agent treatment device 16 in the first embodiment.
Was applied by dissolving γ-aminopropylethoxysilane (a) in Example 2, and N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane (b) dissolved in methanol. Then, this is dried, and the outer layer 12 having a thickness of 0.75 mm is formed using nylon 12 by the outer layer extruder 5.
Was formed to obtain a target resin hose for an automobile.

[0022]

Comparative Example 1 No corona discharge treatment was performed. And
The coupling agent treatment was performed using γ-aminopropylethoxysilane (a). Other than this, Examples 1 and 2
The same operation as described above was carried out to produce an automotive resin hose.

[0023]

Comparative Example 2 Vinylethoxysilane (c) was used as a coupling agent. Otherwise, the same operation as in Examples 1 and 2 was performed to produce an automotive resin hose.

[0024]

Comparative Example 3 No corona discharge treatment and no coupling agent treatment were performed. Otherwise, the same operation as in Examples 1 and 2 was performed to produce a resin hose for automobiles.

The automobile resin hoses of Examples 1 and 2 and Comparative Examples 1 to 3 thus obtained were subjected to a peeling test, a gasoline immersion test, and a heat aging test by the following methods. The results are shown in Table 1 below.

[Peeling Test] The peeling test was conducted according to JIS K61.
03. That is, as shown in FIG.
The hoses of the product of the example and the product of the comparative example were cut into a ring shape so as to have a length of 10 mm, and further cut in the longitudinal direction to obtain test samples. Next, the inner layer 11 and the outer layer 12 were peeled from the cut surface of the test sample, and the peeled ends were fixed to a gripping jig of a tensile tester, and the tensile speed was 25%.
A tensile test was performed at a rate of mm / min, and the peel strength between the two layers was determined from the obtained load. In the figures, L represents the length of the test sample of 10 mm.

[Gasoline Immersion Test] The test sample of the resin hose for automobile subjected to the above-mentioned peeling test was immersed in gasoline at a temperature of 40 ° C. for 168 hours, and the peeling strength was measured again by the above-mentioned measuring method.

[Heat Aging Test] A test sample of the automotive resin hose subjected to the above-mentioned peeling test was subjected to 168 at 125 ° C.
After heating for an hour, the peel strength was measured again by the above-mentioned measuring method.

[0029]

[Table 1]

From Table 1 above, it can be seen that the resin hoses for automobiles of Examples 1 and 2 have excellent adhesive strength. The peel strength after gasoline immersion and after the heat aging treatment hardly changed from the initial strength. In the measurement of the peel strength, it was the coupling agent layer that was destroyed. On the other hand, in the resin hoses for automobiles of Comparative Example Product 1 and Comparative Example Product 3, the inner layer and the outer layer were not bonded.
In addition, the resin hose for automobile of Comparative Example 2 had low adhesive strength, and was peeled off by gasoline immersion and heat aging.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a configuration of an automotive resin hose of the present invention.

FIG. 2 is an explanatory view showing an example of a method for producing a resin hose for an automobile of the present invention.

FIG. 3 is an explanatory view of a structure of a conventional resin hose for an automobile.

FIG. 4 is an explanatory diagram of a test sample used for a peel test.

[Explanation of symbols]

 Reference Signs List 11 inner layer made of fluororesin 12 outer layer made of polyamide thermoplastic resin 17 layer treated with aminosilane coupling agent

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 27:12 (72) Inventor Hiroaki Ito Komaki City, Aichi Pref. 58) Investigated field (Int.Cl. ⁶ , DB name) B29D 23/00-23/24 B29C 47/20-47/28 B67D 5/00 F16L 9/00-11/18 B32B 1/08

Claims (3)

(57) [Claims] 1. An automotive resin hose in which a polyamide-based thermoplastic resin outer layer is laminated on an outer periphery of a fluororesin inner layer, wherein the outer peripheral surface of the fluororesin inner layer is formed as a rough surface, An automotive resin hose, characterized in that an aminosilane-based coupling agent-treated layer is formed on the rough surface. 2. The resin hose for an automobile according to claim 1, wherein the outer peripheral surface of the inner layer made of a fluororesin is formed in a rough surface by corona discharge treatment. 3. A method for manufacturing a resin hose for an automobile, comprising a polyamide-based thermoplastic resin outer layer laminated on an outer periphery of a fluorine-based resin inner layer, wherein the fluororesin inner layer is formed by extrusion molding. After performing a pre-adhesion treatment by corona discharge treatment on the outer peripheral surface of the formed fluororesin inner layer, a treatment layer is formed by an aminosilane coupling agent treatment, and a polyamide is formed on the aminosilane coupling agent treatment layer. A method for producing an automotive resin hose, comprising forming an outer layer made of a thermoplastic resin by extrusion molding.