JP2900739B2 - Continuous hose manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous method for producing a hose in which an innermost layer is formed of a thermoplastic resin having a fluorine atom in its molecular skeleton (hereinafter referred to as "fluorinated thermoplastic resin").

[0002]

2. Description of the Related Art As a hose having an innermost layer made of a fluorine-based thermoplastic resin, for example, a copolymer of ethylene tetrafluoride-ethylene (ETF) as shown in FIG.
E), an innermost layer 11 is formed, and an outer layer 12 made of a polyamide resin is laminated on the outer peripheral surface of the innermost layer.
Layered hoses are known. The hose in which the innermost layer is formed of a fluorine-based thermoplastic resin has excellent properties such as corrosion resistance to chemicals and gasoline,
For example, it is used as a hose for automobile fuel piping. However, the fluorine-based thermoplastic resin has a drawback that adhesion to other materials such as a polyamide resin is low. Therefore, in order to manufacture this hose, it is necessary to perform a special pre-adhesion treatment. As such pre-adhesion treatment, a method using a metal sodium complex solution has been conventionally performed. In this pretreatment method, for example, in the case of manufacturing a hose having the above-mentioned two-layer structure, a cylindrical innermost layer formed by ETFE is immersed in a complex solution of sodium metal, then pulled up, washed and dried. Is the way. According to this pretreatment method, since the outer peripheral surface of the innermost layer made of ETFE is activated, it can be bonded to the outermost layer made of a polyamide resin, but requires immersion, washing, and drying steps.
There is a disadvantage that the manufacturing process becomes long. In addition, as described above, continuous processing and high-speed processing are difficult due to the presence of the immersion, washing, and drying steps, and thus there is a disadvantage that productivity is low.

[0003]

On the other hand, as a pre-adhesion treatment between a fluorine-based thermoplastic resin and another material, application of a glow discharge plasma treatment under vacuum has been proposed. Used for processing. This method has an excellent pretreatment effect, and it is possible to obtain a sheet having a high adhesive strength. However, the plasma treatment is a pretreatment method under a vacuum, and thus requires special equipment and equipment. That is, in order to stabilize the glow discharge and obtain a good plasma state, 1 × 10 ⁻⁵ to 1 × 1
It is necessary to maintain a very high vacuum in the range of ⁰ Torr. For this reason, there is a disadvantage that special equipment and devices such as a processing space having a high degree of hermeticity and a high-performance vacuum pump are required. Further, since it is necessary to maintain a high degree of vacuum, it is inevitably a batch process, so that it is difficult to apply this to a continuous method for producing a hose that is a long product. In other words, when trying to apply this to hose products, after extruding the innermost layer,
This is temporarily wound on a reel, transferred to the plasma processing space, and subjected to batch processing. According to this, steps such as winding and transport of the innermost layer onto a reel are indispensable, and thus cannot be applied to actual production.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a continuous hose manufacturing method capable of continuously manufacturing a hose in which the innermost layer is formed of a fluorine-based thermoplastic resin.

[0005]

In order to solve the above-mentioned object, a continuous production method of a hose according to the present invention comprises the steps of: extruding the innermost layer when manufacturing a hose in which the innermost layer is formed of a fluorine-based thermoplastic resin; continuously formed by, after performing adhesion pretreated successively by plasma treatment under atmospheric pressure on the outer peripheral surface of the innermost layer is the formed polyamide resin layer by extrusion molding on the outer circumferential surface of the innermost layer Are continuously bonded and formed.

[0006]

In other words, the present inventors have conducted a series of studies focusing on the application of a plasma processing method capable of obtaining a high adhesive force in order to achieve the above object. As a result, as the above-mentioned plasma processing method, after performing the pre-bonding treatment on the outer peripheral surface of the innermost layer made of a fluorine-based thermoplastic resin by plasma treatment under atmospheric pressure, using another material on the outermost surface of the innermost layer The present inventors have found that if the outer layer made of a polyamide resin is bonded and formed by extrusion molding, it is possible to manufacture the hose continuously and at a high speed without using any special equipment and apparatus, and reached the present invention.

Next, the present invention will be described in detail.

The pre-adhesion treatment used in the method of manufacturing the hose of the present invention is, for example, a plasma treatment under atmospheric pressure, which is one of the methods for forming a film on the surface of a base material such as a metal (JP-A-2-1517).
No. 1) can be applied.

Hereinafter, the present invention will be described based on examples together with comparative examples.

FIG. 1 is a schematic view of a hose manufacturing apparatus used in an embodiment of the present invention. In this embodiment, a hose having a two-layer structure in which the innermost layer is made of ETFE and the outer layer is made of a polyamide resin is continuously manufactured as follows.

That is, first, the mandrel 3 is supplied from the mandrel supply device 1 to the innermost extruder 4 at 6 to 10 m / min.
And the innermost extruder 4
The inner diameter of the mandrel 3 is 6.5 mm on the outer peripheral surface using TFE.
The innermost layer 11 is formed with a thickness of 0.25 mm. Then
The mandrel 3 on which the innermost layer 11 is formed passes through an air cooling zone 15 having a length of 2 m, and is guided into the plasma processing apparatus 6 through a seal portion 13. In addition, as shown in FIG. 2, the seal portion 13 is formed of a cone-shaped seal formed of an elastic body such as fluoro rubber. In the plasma processing apparatus 6, a gas mixture of a rare gas He and a monomer gas CF ₄ (mixing ratio) is supplied from the gas supply device 9 so that plasma is stably generated under the atmospheric pressure. : CF ₄ /
He = 2/100) is set to 500 per minute by the flow rate control valve 14.
The gas exhaust device 1 is supplied at a flow rate of
0 is exhausted outside the plasma processing apparatus 6. Thereby, the inside of the plasma processing apparatus is always maintained at a constant gas composition. As the rare gas, in addition to He, Ne, Ar, and the like can be used. The monomer gas may be an unsaturated hydrocarbon such as ethylene or propylene in addition to CF ₄ , or C ₂ F ₆ , CHF ₃ or SF.
Halogenated hydrocarbons such as ₆ , hydrocarbons having other functional groups, and the like can be used. The types of the rare gas and the monomer gas can be appropriately selected according to the conditions of the plasma treatment. The mixing ratio and the flow rate of the mixed gas can also be appropriately selected according to the conditions of the plasma processing. A space between the electrodes 7 is a plasma processing zone. The mandrel 3 on which the innermost layer 11 is formed is guided to this plasma processing zone, and pre-adhesion processing by plasma processing is performed on the outer peripheral surface of the innermost layer 3. . In the processing zone, the length of the effective zone is 2 m. As a condition of the plasma treatment, for example, a high frequency power supply 8 is applied to the electrode 7 under the conditions of a frequency of 3 kHz and a voltage of 3 kv to generate glow discharge plasma, and a pre-bonding process is performed. As described above, the supply speed of the mandrel 3 at this time is 6 to 10 m per minute, and the length of the effective zone is 2 m, so that the processing time is 12 to 20 seconds. The plasma treatment time is appropriately determined depending on conditions such as the type of the fluorine-based thermoplastic resin and the thickness of the innermost layer. The mandrel 3 that has passed through the plasma processing zone passes through the seal portion 13 and is discharged to the outside of the plasma processing apparatus 6. The mandrel 3 immediately has a thickness of 1. The outer layer 12 is formed using a polyamide resin with a thickness of 5 mm. The mandrel 3 on which the innermost layer 11 and the outer layer 12 are formed
Is wound by the mandrel take-up machine 2.

By such a continuous process, the innermost layer 11 as shown in FIG. 3 is made of a fluorine-based thermoplastic resin (ETF).
E), a hose having a two-layer structure in which the outer layer 12 is made of a polyamide resin can be manufactured continuously and at a high speed.

[0013]

Comparative Example On the other hand, as a comparative example, the same operation as in the example was performed except that the plasma treatment was not performed on the outer peripheral surface of the innermost layer 11 when a hose was manufactured using the above manufacturing apparatus. A layered hose was manufactured.

With respect to the hoses of Examples and Comparative Examples thus obtained, the adhesive force between the innermost layer and the outer layer was measured by the following method.

[Adhesive Strength] The adhesive strength was measured in accordance with JIS-K6103. That is, as shown in FIG. 4, 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. Then, from the cut surface of this test sample, the innermost layer 1
1 and the outer layer 12 were peeled off, the peeled end was fixed to a gripping jig of a tensile tester, a tensile test was performed at a tensile speed of 25 mm / min, and the adhesive force between the two layers was determined from the obtained load. In FIG. 4, L indicates the length of the test sample.

From the above measurement of the adhesive strength, it can be seen that the hose obtained in the examples has an adhesive strength of 8 kg / 25 mm or more, and has a strong adhesive strength. Further, in the measurement of the adhesive force in this example, it was found that the innermost layer was destroyed, and the adhesive portion between the innermost layer and the outer layer was not peeled off. On the other hand, in the hose of the comparative example, the innermost layer and the outer layer were not bonded.

In this embodiment, ETFE is used as a fluorine-based thermoplastic resin as a material for forming the innermost layer. However, the present invention is not limited to this. Examples of fluorine-based thermoplastic resins other than ETFE include polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (CTFE), a copolymer of ethylene and chlorotrifluoroethylene (ECTFE), and hexafluoropropylene and tetrafluoroethylene. Copolymer (FEP),
Examples thereof include fluorinated alkoxyethylene resin (PFE) and polytetrafluoroethylene (PTFE), and the present invention can be effectively applied to these fluorine-based thermoplastic resins.

In this embodiment, the present invention is applied to the manufacture of a hose having a two-layer structure. However, the present invention is not limited to this. In other words, by combining a plasma processing apparatus under atmospheric pressure and an extruder, a continuous and high-speed hose can be formed even if a layer other than the innermost layer is a three- or more-layer hose made of a fluorine-based thermoplastic resin. Can be manufactured.

[0019]

As described above, according to the continuous manufacturing method of the hose of the present invention, when manufacturing a hose in which the innermost layer is formed of a fluoroplastic resin, the innermost layer is continuously formed by extrusion molding. After continuously performing the pre-adhesion treatment by plasma treatment under atmospheric pressure on the outer peripheral surface of the innermost layer formed above, the outer peripheral surface of the innermost layer is extruded to form a polymer.
A configuration is adopted in which an outer layer made of a mid resin is continuously formed by bonding. For this reason, even with a hose in which the innermost layer is formed of a fluorine-based thermoplastic resin having low adhesiveness to other materials,
It is possible to manufacture continuously and at high speed without complicated steps and without using special equipment and devices. As a result, the productivity of the hose is improved, and the apparatus can be manufactured at a low cost because the apparatus has a simple structure. Furthermore, according to the pre-adhesion treatment of the present invention, since the adhesiveness between the fluorine-based thermoplastic resin and other materials is high, a hose having excellent strength can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a hose manufacturing apparatus used in one embodiment of the present invention.

FIG. 2 is an explanatory view of a seal portion of the device.

FIG. 3 is an explanatory view of a hose having a two-layer structure in which an innermost layer is formed of a fluorine-based thermoplastic resin.

FIG. 4 is an explanatory diagram of an evaluation method of an adhesive force.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FIB29L 23:00 (56) References JP-A-1-154755 (JP, A) JP-A-4-145139 (JP, A) 62-235339 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 47/00-47/96 B29D 23/00-23/24 C08J 7/00-7/18

Claims (1)

(57) [Claims] In producing a hose in which the innermost layer is formed of a fluorine-based thermoplastic resin, the innermost layer is continuously formed by extrusion molding, and the outermost surface of the formed innermost layer is formed under atmospheric pressure. After continuous application of pre-adhesion treatment by plasma treatment, the outer peripheral surface of the innermost layer is extruded
A continuous method for producing a hose, comprising continuously bonding and forming an outer layer made of a polyamide resin .