JP2001182867A - Low permeability hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low permeability hose provided with an inner surface layer which is formed by simultaneously extruding two layers of a barrier layer of the inmost layer and an outside elastic layer, a reinforcing layer, and an outer surface layer. SOLUTION: This hose can be manufactured simply and in low costs without requiring a long time, has low permeability, low extraction performance, and has a good performance as a transporting hose for a refrigerant, gasoline, LPG, and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-permeability hose used for transporting refrigerant such as freon (HFC134a) for automobile air conditioning, transporting gasoline, transporting liquefied LPG, and the like.

[0002]

2. Description of the Related Art
For various transport hoses, a thermoplastic resin containing polyamide as a main component is used as an innermost layer (barrier layer), and butyl rubber, EPDM, NBR, etc. are used as an outer elastic layer. An inner layer is formed by bonding using an adhesive such as a chlorinated rubber-based material, a reinforcing layer is further coated on the inner layer, and an outer layer is further coated and vulcanized to form an integrated hose. I have.

However, these hoses are manufactured by extruding a barrier layer on a mandrel to form a barrier layer having a thickness of about 0.05 to 0.2 mm, and then applying an adhesive on the barrier layer. After further covering the elastic layer,
Provide a reinforcing layer, extrude and coat the outer surface layer to form an unvulcanized hose, and coat the outer surface with a cloth tape or a thermoplastic resin (resin mold) having a melting point higher than the vulcanization temperature. After vulcanizing and integrating, the cloth tape or the resin mold is peeled off, and the mandrel is pulled out with water pressure or the like to complete the hose.

[0004] Therefore, considerable man-hours and labor are required, and the production cost of the hose is also high.

SUMMARY OF THE INVENTION The present invention has been made to improve the above circumstances, eliminates the use of a mandrel, requires no labor, is simple and economical, and has low permeability and low extraction for transportation of refrigerants and the like. An object of the present invention is to provide a hose having excellent properties.

[0006]

In order to achieve the above object, the present invention provides (1) an inner layer, a reinforcing layer, and an outer layer, wherein the inner layer is an innermost barrier layer. And a low permeability hose characterized by being formed by simultaneously extruding two layers of an outer layer and an outer elastic layer, and (2) an inner layer, a reinforcing layer, and an outer layer, wherein the inner layer is That the innermost barrier layer and the outer elastic layer and the adhesive layer interposed between the barrier layer and the elastic layer and adhering these two layers are formed by simultaneously extruding three layers. Provide a low permeability hose characterized by:

The low-permeability hose of the present invention does not use a mandrel for the production thereof, and the two-layer simultaneous extrusion of a barrier layer and an elastic layer is preferably used for forming the inner surface layer, preferably a barrier layer, an adhesive layer,
Since the three-layer coextrusion of the elastic layer is used, it can be manufactured easily and at low cost without any trouble. In addition, in the obtained hose, the barrier layer and the elastic layer are surely integrated, and in particular, the barrier layer and the elastic layer are firmly joined to each other by interposing an adhesive layer between the barrier layer and the elastic layer, and the flexible hose is flexible. High precision while maintaining the properties, and has low permeability and low extractability. For this reason, in the refrigerant transport hose for air conditioning of automobiles, the refrigerant permeation can be suppressed to a low level, and in transporting gasoline and LPG, extraction from the inner surface layer is prevented, and coloring of gasoline and LP are prevented.
It is possible to prevent the extract from adhering to the G device.

Hereinafter, the present invention will be described in more detail.
As shown in FIGS. 1 and 2, the hose of the present invention includes an inner surface layer 10, a reinforcing layer 20 covering the inner surface layer 10, and an outer surface layer 30 further covering the inner surface layer 10. ,
It has an innermost barrier layer 12 and an outer elastic layer 14. In this case, as shown in FIG.
Preferably, an adhesive layer 16 for adhering the barrier layer 12 and the elastic layer 14 is interposed between the elastic layer 2 and the elastic layer 14.

Here, as the barrier layer, it is preferable to use a thermoplastic resin containing a polyamide resin as a main component. In this case, nylon 6 and nylon 66 can be used as the polyamide-based resin, and it is preferable to use a polymer alloy in which a polyolefin resin such as polyethylene is blended.

The elastic layer is preferably made of a thermoplastic elastomer containing a polyolefin resin and either EPDM or NBR rubber. This thermoplastic elastomer can be made of EPDM or NBR rubber for the soft phase and polyethylene or polypropylene for the hard phase.
01-73 (manufactured by AES Japan) can be used.

As the adhesive layer, a maleic acid-modified polyolefin resin can be used, and as a commercial product, Admer NF300 (manufactured by Mitsui Chemicals, Inc.) can be used.

In the present invention, the inner layer is formed by simultaneously extruding two layers of the barrier layer and the elastic layer, preferably by simultaneously extruding three layers of the barrier layer, the adhesive layer and the elastic layer. Therefore, the inner surface layer can be formed at a stroke without any trouble, and the inner layer can be made flexible, airtight, and excellent in gas permeation resistance and durability.

The inner and outer diameters of the inner layer are determined by
It is appropriately selected according to the place of use and the like, and is not particularly limited, but the inner diameter is 7.5 to 15.5 mm and the outer diameter is 10.0.
mm or more. In this case, the thickness of the barrier layer is 0.05 to 0.5 mm, particularly 0.1 to 0.2 mm
Is preferred in terms of flexibility, gas permeability resistance, and the like. The elastic layer has a thickness of 0.5 to 2.0 mm, especially 1.
It is preferable to set it to 0 to 1.5 mm. Further, the adhesive layer is usually 0.01 to 0.5 mm, particularly 0.05 to 0.1 mm.
mm, and by interposing an adhesive layer, it is possible to reliably prevent the separation of the barrier layer and the elastic layer at the mounting part of the bracket, etc., and to surely prevent the crack of the barrier layer. Can be.

The reinforcing layer may be made of one or more fibers, for example, polyethylene terephthalate fiber, nylon fiber, vinylon fiber, aramid fiber, steel wire having a diameter of about 0.2 to 0.5 mm, stainless steel wire, or the like. It can be formed by a method such as knitting by a common method using the combination, and this may be a spiral structure or the like.

The material of the outer layer is not particularly limited, but is preferably formed from the same thermoplastic elastomer as the elastic layer of the inner layer from the viewpoint of manufacturability and the like. The thickness is 0.5 to 1.5 mm, particularly 0.8 to 1.0 mm
It is preferable that

[0016]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[Examples and Comparative Examples] A thermoplastic elastomer containing a polyolefin resin and a rubber component was used as an elastomer.
Es Japan Santoprene 201-73 (soft phase EPDM, hard phase polypropylene) is used as the elastic layer material, nylon 6 and a polyolefin polymer alloy are used as the barrier layer, and Admer NF300 (maleic acid modified by Mitsui Chemicals) is used as the adhesive layer. These materials were extruded simultaneously in three layers using a three-layer extruder to produce a tube having an inner diameter of 11.4 mm and an outer diameter of 14.4 mm, which was used as an inner surface layer (Example 1). ~
5). Further, an inner surface layer was formed in the same manner as above except that the elastic layer and the barrier layer were simultaneously extruded without using the adhesive layer (Example 6).

For comparison, an inner surface layer in which only an elastic layer and a barrier layer were respectively extruded in a single layer, and an inner layer in which a barrier layer was extruded in a single layer, and an elastic layer was extruded thereon were prepared (Comparative Example 1). ~ 3).

Next, on each inner surface layer, 1
500 denier polyethylene terephthalate (PE
T) Two fibers were combined and knitted using a 24-bobbin knitting machine to a thickness of about 1.0 mm.

Further, the above-mentioned Santoprene 201-73 was extruded with a thickness of 0.8 mm as an outer surface layer on the reinforcing layer, and was coated to produce a hose having an inner diameter of 11.2 mm and an outer diameter of 18.0 mm.

The following properties of the obtained hose were evaluated. Table 1 shows the results.

The reaction force when wound around a cylinder having a flexibility diameter of 200 mm was measured. When the flexibility is inferior, not only is the difficulty in piping increased, but also the vibration transmission characteristics are reduced.
Hereinafter, particularly, 30N or less was judged to be good.

Attachment fittings were attached to both ends of a 0.5 m airtight hose, and the inside of the hose was pressurized to 3.53 MPa with nitrogen gas.
In a state where both ends were sealed with metal fittings, the hose was immersed in water to check for gas leakage, and those without internal leakage were evaluated as having no abnormality.

[0024]Gas permeability As in the case of checking the airtightness, a fitting is attached to a 0.5 m hose.
Attachment, JASO M321-1
According to the method of 999, it was measured as follows. In the hose
1cm^Three0.6 g of HFC134a is enclosed per unit,
Leave in the temperature of 80 ° C for 96 hours, and after 24 hours and 96 hours
Measure the weight loss of HFC134a for a while, and calculate this value.
The amount of HFC134a was reduced, and JASO was added to this value.
Multiply by the specified coefficient of M321-1999 to obtain the transmission amount
Was. The results are in accordance with the JASO M321-1999
Standard of 9.7kg / m ^Two/ Year or less was defined as good.

[0025] was carried out as follows according to the method of the durability JASO M321-1999. Attach metal fittings to both ends of the hose with a length of 0.5 m, and repeatedly attach to the pressure tester in an inverted U-shape.
Repeated pressurization of 0 MPa and 3.53 MPa was repeated 150,000 times in an atmosphere at 100 ° C., and it was confirmed whether or not the hose burst or leaked. Furthermore, the same airtightness test as described above was performed on hoses that did not burst or leak. As in the case of gas permeability, it was determined that there was no abnormality in airtightness after repeated pressurization as a standard of JASO M321-1999.

[0026]

[Table 1]

[0027]

The hose of the present invention can be manufactured easily and inexpensively without any trouble, and has low permeability.
It has low extractability and has excellent performance as a hose for transporting refrigerants, gasoline, LPG, etc.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a hose according to one embodiment of the present invention.

FIG. 2 is a schematic perspective view of a hose according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 inner layer 12 barrier layer 14 elastic layer 16 adhesive layer 20 reinforcing layer 30 outer layer

Continued on the front page F-term (reference) 3H111 AA02 BA12 BA15 CB05 CB06 CB09 DA26 DB08 DB09 EA04 EA15 4F100 AK03A AK03C AK03G AK03J AK27C AK27J AK29C AK29J AK42B AK46A AK46J AK75C AL01C02A01C01A01C GB90 JB16C JD01 JD01A JK07C JK13 JK17 JL00

Claims (4)

[Claims] An inner surface layer, a reinforcing layer, and an outer surface layer, wherein the inner surface layer is formed by simultaneously extruding two layers of an innermost barrier layer and an outer elastic layer. Low permeability hose. 2. The barrier layer is mainly composed of a thermoplastic resin mainly composed of a polyamide resin, and the elastic layer is mainly composed of a thermoplastic elastomer containing a polyolefin resin and EPDM or NBR rubber. The low permeability hose according to claim 1, wherein 3. An inner surface layer, a reinforcing layer, and an outer surface layer, wherein the inner surface layer is interposed between the innermost barrier layer and the outer elastic layer, and between the barrier layer and the elastic layer to bond the two layers. A low-permeability hose formed by simultaneously extruding three adhesive layers with each other. 4. The barrier layer is mainly composed of a thermoplastic resin mainly containing a polyamide resin, and the elastic layer is mainly composed of a thermoplastic elastomer containing a polyolefin resin and EPDM or NBR rubber. And
The low permeability hose according to claim 3, wherein the adhesive layer is mainly composed of a polyolefin resin modified with maleic acid.