JP2589238B2 - Hose for transporting refrigerant and its joint structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hose for transporting refrigerant and a joint structure thereof, and more particularly to a hose suitably used for piping of a car cooler or an air conditioner of an automobile, and a joint structure of such a hose.

[0002]

2. Description of the Related Art Conventionally, a hose for transporting a refrigerant such as chlorofluorocarbon gas is integrally formed of an inner tube layer, an outer tube layer on the outer side thereof, and a fiber reinforcing layer interposed between both layers. A three-layer structure is known. In such a hose, the inner tube layer is generally formed of acrylonitrile-butadiene copolymer rubber (NBR) or chlorosulfonated polyethylene rubber (CSM), and the fiber reinforcing layer is formed of polyester fiber, rayon. Fibers, and a net formed by using yarns made of organic fibers such as nylon fibers, and the outer tube layer is formed of an elastomer or terpolymer obtained from an ethylene-propylene-non-conjugated polyene (diene) terpolymer. Is formed of rubber-like elastic material (EPDM) or chloroprene rubber (CR). A spiking hole extending from the outer surface of the outer tube layer to the fiber reinforcing layer is provided at an appropriate position in the outer tube layer. It does not stay between the layers. This is because if the permeated Freon gas stays in the multilayered hose wall, that portion will swell and cause delamination.

[0003] However, such a hose having a structure entirely formed of a rubber layer except for a fiber reinforcing layer is flexible and easy in piping work; it has a good seal with joints such as nipples. In general, rubber materials, particularly rubber materials such as NBR and CSM used as the inner tube layer have gas permeability, although they have advantages such as airtightness. When a low-molecular-weight gas such as chlorofluorocarbon gas is used, there is an inherent disadvantage that gas leakage occurs. In other words, in a conventional hose using such a rubber material as a main constituent material, refrigerant gas such as chlorofluorocarbon, which is circulated and circulated in the hose, leaks to the outside through the hose wall, thereby gradually reducing the amount of circulated refrigerant. Therefore, there is a problem in maintenance that cooling performance is inferior for long term and gas charging (filling of refrigerant) must be performed frequently in order to maintain cooling capacity. . In particular, improvement of gas permeability in such a hose for transporting refrigerant has become a major issue in response to a recent social problem of destruction of the atmospheric ozone layer due to chlorofluorocarbon gas.

[0004] Therefore, in order to improve the refrigerant impermeability of such hoses, it has been studied to form one layer of the inner tube layer of the hose from a resin material having excellent refrigerant impermeability. For example, a hose in which a layer made of a polyamide resin such as nylon 6, nylon 66, or a copolymer thereof is used as one of the inner tube layers has been disclosed. While the impermeability is greatly improved, such a polyamide resin is extremely rigid, which causes a problem that the flexibility of the entire hose is lost. Further, if the thickness of the polyamide resin layer is reduced in order to ensure flexibility, there arises a problem that the intended refrigerant gas impermeability is impaired.

[0005] As described above, the conventional hoses have advantages and disadvantages for transporting the refrigerant, and in recent years, in a situation where a further improvement in the impermeability of the refrigerant gas is required, there is a problem in terms of quality. Was also not satisfied.

[0006]

Here, the present invention has been made in view of such circumstances, and an object thereof is to provide a refrigerant transport hose, while maintaining its excellent refrigerant impermeability. It is to improve its flexibility at the same time. Further, the present invention also provides a joint structure for such a refrigerant transport hose, which is sufficiently durable and can provide a joint structure capable of withstanding long-term use under severe conditions.
That is the subject.

[0007]

In order to solve the problem, the present invention has a single-layer or multilayer inner tube layer, an outer tube layer concentrically located radially outside the inner tube layer, and an inner tube layer interposed between both layers. In a hose integrally formed from a fiber reinforcing layer, a single layer of the inner tube layer or one of the multiple layers of the inner tube layer has a weight ratio of the modified polyolefin to the polyamide resin of 40/60 to 10 /. 90. A refrigerant transport hose comprising a resin composition in which 1 to 10% by weight of ε-caprolactam is added to and contained in the 90 blend.

In the refrigerant transport hose according to the present invention, the inner tube layer is advantageously provided integrally with the inner resin layer made of the resin composition and a radially outer side of the inner resin layer. A plurality of layers including an outer rubber layer made of a non-polar rubber material, and the inner resin layer and the outer rubber layer are preferably formed of a chlorinated rubber-based adhesive.
It will be adhered via an agent or a phenolic adhesive.

In the present invention, there is also provided a joint structure in which the end of the hose for transporting refrigerant as described above is connected to the end of the nipple by external fitting, and the outer peripheral surface of the nipple is connected to the hose. The joint structure of a hose for transporting a refrigerant, characterized in that the joint between the inner peripheral surface and the inner peripheral surface is sealed with a chlorine-based elastomer in which an acid acceptor is dispersed and contained, is also the gist of the invention.

In such a joint structure, the acid acceptor generally contains 5 to 25% by weight of the chlorine-based elastomer.
At a ratio of.

[0011]

In essence, the present invention has been made by conducting various studies with the aim of imparting flexibility to a polyamide resin used as a material constituting one layer of a hose. As a result, ethylene and / or propylene are used as basic components. A modified polyolefin such as a graft polymer obtained by graft-polymerizing an unsaturated carboxylic acid or a derivative thereof to a polyolefin to be formed, and a polyamide resin selected from nylon 6, nylon 66, nylon 12, or a copolymer thereof. Ε-caprolactam is mixed at a ratio of 1 to 10% by weight with a blend obtained by blending at a mixing ratio of The gas impermeability and flexibility of the hose at the same time Found that crimped can, it was accomplished the present invention.

Further, when a non-polar rubber layer such as ethylene propylene rubber, butyl rubber, halogenated butyl rubber or the like is adopted as a rubber layer adjacent to the outer side of one resin layer of the inner tube layer made of such a resin composition, In particular, they have found that the adhesiveness between the resin layer and the rubber layer can be significantly improved.

Further, during the course of a series of studies on the sealing agent used for the joint structure of the refrigerant transport hose as described above, the inventors of the present invention have conducted chlorinated polyethylene,
It has been found that when a chlorine-based elastomer such as chlorosulfonated polyethylene is used as a sealing agent, it exhibits extremely excellent properties such as adhesion, heat resistance, and light resistance. However, if the chlorine-based elastomer is used as a sealing agent in a joint structure for a long period of time, the unreacted chlorine remaining in the elastomer may oxidize and degrade the resin layer on the inner peripheral surface of the hose, causing cracks and the like. I understood.
In addition, it was found that when a chlorine-free non-chlorine-based elastomer was used, the resin layer did not deteriorate as described above, but the heat resistance and adhesion were poor, and a practical product could not be obtained. Therefore, a further study was made on a method for reducing the activity of chlorine by improving the above-mentioned chlorine-based elastomer and a method for improving heat resistance and adhesion by improving a non-chlorine-based elastomer. As a result, MgO, PbO, etc. When the acid acceptor is dispersed and contained, it is found that such an acid acceptor traps chlorine in the elastomer to form a halide, and the resin layer on the inner peripheral surface of the hose does not deteriorate. It was able to develop further.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific preferred embodiments of the present invention will be shown below, and the configuration of the present invention will be clarified more specifically.

First, FIG. 1 shows one of the typical structures of a hose for transporting refrigerant according to the present invention. Here, reference numeral 2 denotes a resin layer serving as an innermost layer of a hose, which is composed of a resin composition comprising three components of a modified polyolefin, a polyamide resin, and ε-caprolactam. An inner pipe rubber layer 4 having a predetermined thickness is integrally formed adjacent to the resin layer 2 radially outward, and a fiber reinforcing layer 6 is further formed on the outer side of the inner pipe rubber layer 4. An outer tube rubber layer 8 is formed on the outside to form a hose having an integral laminated structure as a whole.

In the hose having such a configuration, the present invention provides a resin layer 2 constituting one layer (inner layer) of the inner tube layer.
As described above, the modified polyolefin and polyamide and ε
-A resin composition having a predetermined composition with caprolactam, thereby greatly improving the flexibility of the hose as compared with a case where the conventional resin composition is merely composed of only a polyamide resin, and is sufficient. This is to provide a refrigerant impermeability. However, regarding the refrigerant impermeability, the resin layer 2 made of the resin composition according to the present invention is used.
Is slightly inferior to a layer composed of only a polyamide resin, but since the resin layer 2 composed of the resin composition according to the present invention is rich in flexibility, its thickness is increased by an amount inferior to the refrigerant impermeability. By doing so, it is possible to impart a refrigerant impermeability that can sufficiently oppose the layer made of only the polyamide resin without impairing the flexibility of the resin layer 2.

The modified polyolefin (A) constituting the resin composition for providing the resin layer 2 is obtained by converting a polyolefin such as a homopolymer of ethylene or propylene or a copolymer thereof into an unsaturated carboxylic acid or a derivative thereof. And those modified by graft polymerization of such a monomer. Examples of the unsaturated carboxylic acid used as such a graft polymerization component include unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; unsaturated dicarboxylic acids such as maleic acid and fumaric acid; and derivatives thereof.
Examples include acid anhydrides, amides, esters, acid halides, and the like. In addition, such a graft polymerization component is used in a range of 0.1 to 20 mol% in the resulting graft polymer.

The polyamide resin (B) to be blended with the modified polyolefin (A) includes
Nylon 6, Nylon 66, Nylon 12, Nylon 6
12, nylon 6/66, etc., and a combination of a plurality of these nylons is also possible.

The modified polyolefin (A)
Ratio (mixing ratio) of styrene and polyamide resin (B)
Is a weight ratio of A due to the balance between flexibility and refrigerant impermeability.
/ B = 40/60 to 10/90, preferably A / B = 30/70 to 20/80. In addition, when the modified polyolefin (A) and the polyamide resin (B) are blended, if the blended ratio of the modified polyolefin is large and the blended ratio of the polyamide resin is small, the refrigerant impermeability of the hose cannot be sufficiently increased. When the proportion of the modified polyolefin is small and the proportion of the polyamide resin is large, the flexibility of the hose is reduced.

According to the present invention, ε-caprolactam, which is widely used as a monomer of nylon 6, is added to the blend comprising the modified polyolefin (A) and the polyamide resin (B) at such a blend ratio. A resin composition mixed and contained in a proportion of 1 to 10% by weight, preferably 3 to 7% by weight in the whole composition, and forming one layer of the inner tube layer using the resin composition. As a result, the flexibility of the inner tube constituting layer made of the obtained resin composition, and eventually the hose, could be drastically improved. Note that ε
-In order to sufficiently exhibit the compounding effect of caprolactam, it is necessary to mix the compound in a proportion of at least 1% by weight, and when the compounding amount exceeds 10% by weight, the refrigerant impermeability of the hose deteriorates. In addition, a bloom phenomenon in which ε-caprolactam oozes on the surface of the hose is caused.

As described above, the resin layer 2, which is one layer of the hose inner tube layer, is composed of a resin composition of a predetermined ratio of a modified polyolefin, a polyamide resin and ε-caprolactam. Ε-caprolactam, which is one component of such a resin composition, is also used as a non-polar rubber material such as ethylene-propylene rubber (EPM), ethylene-propylene-diene terpolymer rubber (EPD).
M), a resin layer constituting the inner tube layer because of its good affinity with rubber materials having no polar functional group such as butyl rubber (IIR), halogenated butyl rubber (Cl-IIR, Br-IIR, etc.) In order to improve the adhesiveness between the inner tube rubber layer 4 and the inner tube rubber layer 4, it is desirable that the inner tube rubber layer 4 be formed of the above-described non-polar rubber material.

Incidentally, an adhesive is appropriately applied between the resin layer 2 and the inner tube rubber layer 4 constituting the inner tube layer, so that the two layers are further integrated. As an adhesive,
A chlorinated rubber-based adhesive, a phenol-based adhesive or the like is preferably used.

As the fiber reinforcing layer 6, those used for ordinary rubber hoses are employed as they are, for example, by braiding or spiral knitting of a yarn mainly composed of synthetic fibers such as polyester fiber and aramid fiber. It is formed. Further, the outer tube rubber layer 8 is the outermost layer of the hose, and is a layer that retains various properties such as light resistance, heat resistance, and water permeability of the hose. Rubber materials such as EPDM and Cl-IIR described above are suitably used. Needless to say, even if a rubber material other than such a rubber material is used, there is no problem.

Incidentally, as the structure of the refrigerant transport hose according to the present invention, various structures other than those shown in FIG. 1 can be appropriately adopted without departing from the spirit of the present invention. In another example of the hose for transporting refrigerant of the present invention, the inner tube layer is a single layer, which is composed of only the resin layer 2. Further, in still another example of the refrigerant transport hose according to the present invention shown in FIGS. 3 and 4, the innermost layer of the inner tube layer is provided on the inner surface of the resin layer 2 of the hose shown in FIGS. Inner rubber layer 1
0 is provided at a predetermined thickness. The inner rubber layer 10 is formed of a material rich in rubber elasticity, and the presence of the inner rubber layer 10 improves the sealing performance with joints such as nipples disposed at both ends of the hose. The layer configuration of such a hose is appropriately selected according to its use, and thereby it is possible to obtain a predetermined effect associated with each layer configuration.

In these exemplary hose configurations,
The thickness of the hose constituting layers such as the resin layer 2, the inner rubber layer 4, the inner rubber layer 10, and the outer rubber layer 8 constituting the inner tube layer is as follows.
It will be determined appropriately according to the type of material forming them, the thickness of the hose, its wall thickness, etc. In a practical hose size, for example, the thickness of the resin layer 2 is
The thickness is set to 0.05 to 0.5 mm, preferably about 0.15 mm, and the thickness of the inner tube rubber layer 4 is set to 1.0 to 3.0.
mm, preferably about 2 mm. However, the thicknesses of the resin layer 2 and the inner tube rubber layer 4 are appropriately selected from the viewpoint of a balance between flexibility and gas impermeability. Further, the thickness of the outermost outer tube rubber layer 8 is usually about 1 to 3 mm.

By the way, such a hose for transporting refrigerant according to the present invention can be manufactured by sequentially laminating the respective hose constituent layers, for example, as follows.

A) A resin or rubber composition for forming the inner tube layer (2, 4, 10) is extruded on a rubber or resin mandrel from an extruder to form a tubular body on the mandrel. By repeating this extrusion operation a plurality of times, or by simultaneously extruding, FIG. 1, FIG.
As shown in the above, an inner tube layer composed of a plurality of layers can be formed. At the time of such extrusion molding, an adhesive is appropriately applied between a plurality of layers constituting the inner tube layer.

B) Next, after applying an adhesive (rubber glue) to the outer peripheral surface of the inner tube layer composed of a single layer or a plurality of layers as necessary, a fiber reinforcing yarn is braided or spiral knitted. The fiber reinforcement layer (6) is formed by a method such as the following.

C) The formed fiber reinforcing layer (6)
After applying a predetermined adhesive (rubber glue or the like) to the outer peripheral surface of the rubber, the rubber composition for forming the outer tube layer is extruded thereon to form a desired outer tube rubber layer (8) to a predetermined thickness. I do.

D) The desired hose can be obtained by vulcanizing (crosslinking) the thus obtained laminated tube and integrating it, and then extracting the mandrel.
The vulcanization conditions at this time are usually 140 to 17
A temperature of about 0 ° C. and a vulcanization time of about 20 to 90 minutes will be employed.

By the way, such excellent features of the hose for transporting refrigerant according to the present invention can be clearly recognized from the following hose production and evaluation results.

First, various types of hoses having a multilayer structure shown in FIG.
Manufactured. In addition, in the manufacture of the hose, as described above,
Extrusion molding is performed sequentially from the innermost layer of the hose to obtain a multi-layer laminated tube, which is then heated and vulcanized to form a hose with an integral multi-layer structure (inner diameter: 11.0 mm). did. The composition of each rubber material used in Table 1 is as follows.

1) Cl-IIR compounding component blending amount (parts by weight) polymer 100 FEF carbon black 50 paraffin-based process oil 20 ZnO 5 stearic acid 1 tetramethylthiuram disulfide 1 2) EPDM compounding component compounding amount (parts by weight) Polymer (C ₃ ) 100 FEF carbon black 100 paraffin-based process oil 60 ZnO 5 stearin Acid 1 Sulfur 1 Tetramethylthiuram disulfide 2 N-Cyclohexyl-2-benzothiazylsulfenamide・13) NBR compounding component blending amount (parts by weight) polymer (AN = 42%) 100 FEF carbon black 60 dioctyl phthalate ... 10 ZnO ... 5 Stearic acid ... 1 Sulfur ... 1 Tetramethylthiuram disulfide ... ... 2 N-cyclohexyl-2-benzothiazylsulfenamide 1

The hose thus obtained was evaluated for its flexibility and refrigerant impermeability, and the adhesiveness between the resin layer (2) and the inner tube rubber layer (4). The results are shown in Table 1 below. In addition, each evaluation was performed as follows.

Hose A flexible hose (inner diameter: 11.0 mm) is cut into a length of 400 mm, one end of which is fixed on a flat plate, and the other end is bent to obtain a bending stress required to reach the flat plate. It was measured and evaluated. The smaller the value, the higher the flexibility. A refrigerant impermeable hose (inner diameter: 11.0 mm) was cut into a length of 500 mm, and 40 g of Freon 134a was sealed in a liquid state in the hose, and both ends were sealed.
The total weight was measured, and the number of grams of CFC permeated was determined and evaluated in comparison with the initial weight. A smaller value indicates that the refrigerant gas is more impermeable. Adhesive inner diameter: After halving the hose having a diameter of 11.0 mmφ, the peeling between the resin layer (2) and the inner tube rubber layer (4) was evaluated to make a qualitative judgment.

[0036]

[Table 1]

As is clear from the results shown in Table 1, the hose No. having a multilayer structure having the resin layer (2) composed of the resin composition according to the present invention. Nos. 1 to 8 have excellent performance in any of the hose flexibility, refrigerant impermeability, and adhesiveness to the inner tube rubber layer (4).

On the other hand, a hose in which the inner tube layer is made of only a rubber material, such as a conventional hose (No. 13)
Is significantly inferior in refrigerant impermeability, and a blend of modified polyolefin and polyamide resin has ε
-In the case of hoses (No. 10 and No. 12) using a composition containing no caprolactam, the hose flexibility is inferior, and the blending ratio of the modified polyolefin and the blending ratio of ε-caprolactam are extremely large. Even in this case, it is recognized that the refrigerant impermeability decreases.

Incidentally, when piping such a refrigerant transport hose according to the present invention, a joint structure as shown in FIG. 5 is generally used. In this joint structure, the end of the hose 14 is externally fitted to the connection end of the nipple 12 having an uneven outer peripheral surface, and the fitting part between the hose 14 and the nipple 12 contains an acid acceptor dispersed therein. Sealing is performed with a sealing agent 16 made of a chlorine-based elastomer that has been made, thereby effectively improving the adhesion between the hose 14 and the nipple 12.

The acid acceptor used here traps the generated halogen to form a halide and prevents the other components from deteriorating. Specifically, for example, MgO, PbO , Hydrotalcite, epoxy resin, dibasic phthalate, etc.
It is preferable to use gO (powder). When this MgO powder is used, it is preferable to use a powder having a particle size of about 19 μm because of excellent dispersibility in the elastomer. The dispersibility can be further improved by coating the surface of MgO with a surfactant such as a fatty acid ester in advance.

On the other hand, the chlorine-based elastomer serving as a base material in which such an acid acceptor is dispersed and contained refers to a chlorinated elastomer obtained by reacting chlorine with the elastomer, and includes chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, and the like. No. Among them, chlorosulfonated polyethylene rubber is preferred.

The amount of the acid acceptor to be added to the chlorine-based elastomer is 5 to 2 parts with respect to the solid content of the elastomer.
It is preferable that the content be within the range of 5% by weight. If the amount of the acid acceptor is less than 5% by weight, the effect of trapping the halogen by the acid acceptor is weak, and the deterioration of the hose resin layer cannot be completely prevented. If the amount is more than the weight%, the obtained elastomer composition has reduced tackiness, and the sealing property between the hose 14 and the nipple 12 is reduced.

The joint structure as described above can be formed by using each of the above materials, for example, as follows. That is, first, a chlorine-based elastomer is mixed with an acid acceptor such as MgO and a solvent such as toluene at an appropriate mixing ratio,
The mixture is uniformly kneaded by a mixer to prepare a fluid elastomer liquid. Next, as shown in FIG. 5, the prepared elastomer solution containing an acid acceptor is applied to the outer peripheral surface of the nipple 12 to form a layer having a predetermined thickness made of the sealing agent 16. A hose 1 in which one of the above-mentioned inner tube layers is constituted by a resin layer 2 made of a predetermined resin composition on a nipple 12 provided with an agent layer (16)
4 is externally fitted. Then, if necessary, a socket similar to the conventional one is externally fitted on the external fitting portion,
By pressing, the connection is completed and the desired joint structure is achieved.

According to such a joint structure, the hose 14
And the nipple 12 are sufficiently sealed, and the resin layer 2 on the inner peripheral surface of the hose 14 is hardly deteriorated even when used for a long time.

In the joint structure as described above, the acid-containing agent-containing elastomer liquid is applied to the outer peripheral surface of the nipple 12.
Conversely, there is no problem if the elastomer liquid containing the acid acceptor is applied to the inner peripheral surface of the hose 14 and then fitted to the nipple 12.

The excellent effects of such a joint structure are also apparent from the following experimental results.

That is, first, six types of elastomer liquids were prepared according to Table 2 below, and they were applied to the outer peripheral surface of the nipple 12 as shown in FIG. 5, respectively. Hose for transporting refrigerant with structure 1
4 was externally fitted to form a joint structure. Then, after the formed joint portion was left at a temperature of 120 ° C. for 168 hours, the presence or absence of deterioration of the resin layer (2) in the hose 14, the sealability, and the adhesion were evaluated.

The presence or absence visual deterioration of the resin layer, to observe the resin layer of the hose 14 (2) within the peripheral surface was evaluated for the presence of cracks. ○ ・ ・ ・ No cracks × ・ ・ ・ Cracks Sealing The obtained joints were immersed in water, and nitrogen gas was added for 3 hours.
The mixture was allowed to pass at a gas pressure of 0 kg / cm ² for 5 minutes, and it was observed whether or not gas leaked from the joint portion to generate bubbles.・ ・ ・: No bubbles were generated. ・ ・ ・: Slight bubbles were generated. ・ ・ ・: Bubbles were generated. The nipple 12 of the adhesive joint was held with one hand and the hose 14 was pulled out with the other hand. It was evaluated whether the hose 14 was easily detached. ○ ・ ・ ・ Not detached △ ・ ・ ・ Slightly detached × ・ ・ ・ Easily detached

[0049]

[Table 2]

[0050]

As is apparent from the above description, in the refrigerant transport hose according to the present invention, one layer constituting the inner tube layer comprises a modified polyolefin, a polyamide resin and ε-caprolactam in a predetermined ratio. By being formed from a resin composition obtained by blending with a resin, it has excellent refrigerant impermeability and excellent flexibility at the same time, and is a car satisfying strict requirements in recent years. Ideal for cooler and air conditioner hoses.

Further, according to the joint structure of the hose for transporting refrigerant according to the present invention, due to the excellent durability, adhesion and sealing properties of the chlorine-based elastomer, no liquid leakage or the like occurs from the joint, and Of sufficient strength can be obtained,
Moreover, since the residual chlorine in the elastomer is trapped by the acid acceptor contained in the chlorine-based elastomer, the resin layer of the hose inner tube layer, which has been deteriorated and destroyed when it comes into contact with the chlorine-based elastomer, is not deteriorated. It can be used over a wide range.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a typical example of a refrigerant transport hose according to the present invention.

FIG. 2 is a hose cross-sectional view showing another example of the refrigerant transport hose according to the present invention.

FIG. 3 is a cross-sectional view of a hose for showing still another example of the hose for transporting refrigerant according to the present invention.

FIG. 4 is a cross-sectional view of another example of a refrigerant transport hose according to the present invention.

FIG. 5 is a partially sectional explanatory view showing an example of a joint structure according to the present invention.

[Explanation of symbols]

 2 resin layer 4 inner tube rubber layer 6 fiber reinforcement layer 8 outer tube rubber layer 10 inner surface rubber layer 12 nipple 14 hose 16 sealing agent

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location // B29K 21:00 23:00 67:00 105: 08 B29L 9:00

Claims (5)

(57) [Claims] 1. A monolayer or multilayer inner tube layer, an outer tube layer concentrically located radially outward of the inner tube layer, and a fiber reinforcing layer interposed between the two layers. A single layer of the inner tube layer or one of the layers of the inner tube layer has a weight ratio of the modified polyolefin to the polyamide resin of 40/6.
1 to 10% by weight of ε-
A refrigerant transport hose comprising a resin composition to which caprolactam is added and contained. 2. An outer rubber layer made of a non-polar rubber material, wherein the inner tube layer is integrally provided adjacent to an inner resin layer made of the resin composition and radially outside the inner resin layer. The refrigerant transport hose according to claim 1, wherein the hose includes a plurality of layers. 3. The method according to claim 1, wherein the inner resin layer and the outer rubber layer are
The hose for transporting a refrigerant according to claim 2, wherein the hose is bonded via a chlorinated rubber-based adhesive or a phenol-based adhesive. 4. A joint structure in which the end of the hose for transporting refrigerant according to claim 1 is connected to the end of a nipple by externally fitting the end, and an outer peripheral surface of the nipple and an inner periphery of the hose. A joint structure for a hose for transporting refrigerant, characterized in that a gap between the hose and the surface is sealed with a chlorine-based elastomer containing an acid acceptor dispersed therein. 5. The joint structure for a hose for transporting refrigerant according to claim 4, wherein the acid acceptor is contained in an amount of 5 to 25% by weight based on the chlorine-based elastomer.