JP2010101373A - Refrigerant transport hose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerant transport hose whose structure is not complex, which is easy to manufacture, and which causes no leak of a refrigerant even when the hose is bent or deformed. <P>SOLUTION: The refrigerant transport hose 1 includes at least a refrigerant barrier layer 2 and rubber layers 3, 5. The refrigerant barrier layer 2 is a metal foil whose tensile elasticity is not more than 70 GPa, whose tensile strength is not less than 1 GPa, and whose elastic deformability is not less than 2.5%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a refrigerant transport hose.

Conventionally, as a hose for transporting a refrigerant used in a car air conditioner or the like, a hose in which a polyamide resin or a modified butyl rubber is arranged on an inner tube of the hose and used as a refrigerant barrier layer has been generally used. In addition, R134a has been conventionally used as the refrigerant, but the global warming potential of R134a has been a large problem of about 1700 times that of CO ₂ . For this reason, it has become an important technology for global environmental conservation to make refrigerant leakage from the hose as close to zero as possible.

  On the other hand, in order to improve the low permeability of the refrigerant transport hose, it has been considered to use a metal foil as the refrigerant barrier layer. However, a general metal has an elastic range of about 1% or less, and cannot follow when the hose is bent or deformed, and is destroyed, and the internal refrigerant leaks. Then, the hose provided with the structure which pinches | interposes metal foil with two or more resin layers was proposed (for example, patent documents 1-3).

JP 2001-165358 A JP 2004-232728 A JP 2004-92792 A

  If the hose has a structure in which such a metal foil is sandwiched between two or more resin layers, refrigerant leakage can be eliminated in principle. However, since such a hose has a complicated structure, there is a problem that the manufacturing process becomes complicated.

  The inventor diligently studied and found a refrigerant transport hose that solves the above problems, and completed the present invention.

The present invention includes the following (1) to (3).
(1) A refrigerant transport hose having at least a refrigerant barrier layer and a rubber layer, wherein the refrigerant barrier layer has a tensile elastic modulus of 70 GPa or less, a tensile strength of 1 GPa or more, and an elastic deformability of 2.5% or more. Is a refrigerant transport hose.
(2) the metal _{foil, Ti 3 (Nb, Ta,} V) + (Zr, Hf, Sc) + consists β type titanium alloy having a composition represented by O, hose transporting refrigerant according to the above (1) .
(3) The method for manufacturing a refrigerant transport hose according to (1) or (2) above, comprising the step of forming a rubber layer on the outer surface of the coolant barrier layer. Method.

  According to the present invention, it is possible to provide a refrigerant transport hose that is not complicated in structure, easy to manufacture, and that does not leak refrigerant even when the hose is bent or deformed. Moreover, the manufacturing method can be provided.

The hose of the present invention will be described in detail.
The hose of the present invention is a refrigerant transport hose having at least a refrigerant barrier layer and a rubber layer, wherein the refrigerant barrier layer has a tensile elastic modulus of 70 GPa or less, a tensile strength of 1 GPa or more, and an elastic deformability of 2.5% or more. It is the hose for refrigerant | coolant transport which is metal foil of this.

<Refrigerant barrier layer>
First, the refrigerant barrier layer will be described.
In the hose of the present invention, the refrigerant barrier layer is made of a metal foil having a tensile modulus of 70 GPa or less, a tensile strength of 1 GPa or more, and an elastic deformability of 2.5% or more. Here, the tensile modulus, tensile strength, and elastic deformability were measured in accordance with JIS K 7113 by using a metal foil cut into a No. 2 dumbbell shape and pulling at a tensile speed of 50 mm / min. This is the value obtained. However, the thickness of the cut-out No. 2 dumbbell-shaped test piece is the same as the thickness of the refrigerant barrier layer in the hose of the present invention, and may be different from the value (1-3 mm) defined in JIS K7113. is there. “Elastic deformability” has the same meaning as that described in paragraphs 0017 and 0026 of JP-A-2002-249836.
The tensile modulus is preferably 60 GPa or less, and more preferably 50 GPa or less.
The tensile strength is preferably 1.5 GPa or more, and more preferably 1.7 GPa or more.
The elastic deformability is preferably 3.0% or more.

  Although the thickness of the said metal foil is not specifically limited, It is preferable that it is 0.1-100 micrometers, It is more preferable that it is 1.0-30 micrometers, It is further more preferable that it is about 20 micrometers.

  In addition, if the said metal foil is a thin film which has said characteristic (tensile elastic modulus, tensile strength, and elastic deformability), the material etc. will not be specifically limited. Examples of the material of the metal foil include aluminum, copper, silver, gold, cobalt, iron, tin, nickel, lead, zinc, titanium, niobium, tantalum, vanadium, zirconium, and hafnium. Further, it may contain oxygen, nitrogen, carbon or the like (solid solution).

  The hose of the present invention having such a refrigerant barrier layer made of metal foil is not complicated in structure, is easy to manufacture, and does not leak refrigerant.

The metal foil is preferably made of a β-type titanium alloy having a composition represented by Ti ₃ (Nb, Ta, V) + (Zr, Hf, Sc) + O, and further 100 atomic% (at%) as a whole. In this case, 15 to 30 at% of a Va group element and 2.4 to 7 at% of O are included, and at least one metal element of Zr, Hf and Sc is 0.3 at% or more in total and Zr Is preferably 15 at% or less, Hf is 10 at% or less, Sc is 30 at% or less, and it is more preferably made of a β-type titanium alloy with the balance being Ti.

Here, the Va group elements include vanadium (V), niobium (Nb), tantalum (Ta), and protactinium (Pa). Among these, one or more of V, Nb and Ta are preferable, and Nb and / or Ta are more preferable.
The range of the Va group element amount is preferably 18 to 27 at%, more preferably 20 to 25 at%. This is because the tensile strength tends to be a more preferable value.

  Further, O is preferably 1.8 to 6.5 at%, and more preferably 2.0 to 6.0 at%. Further, all or part of O may be substituted with N and / or C. It is preferable that the solid solution form of O, N, and C is a metal foil that is an interstitial solid solution.

  Further, the total of one or more metal elements of any one of Zr, Hf and Sc is preferably 1 at% or more, and more preferably 5 at% or more. Moreover, it is preferable that it is 15 at% or less.

  Specific examples of the β-type titanium alloy having such a composition include Ti-23Nb-0.7Ta-2Zr-O and Ti-12Ta-9Nb-3V-6Zr-O.

  Although the manufacturing method of the said metal foil is not specifically limited, For example, when the whole powder is 100 atomic% (at%), it contains 15 to 30 at% Va group element and 2.4 to 7 at% O, One or more metal elements of any one of Zr, Hf and Sc are included in a total amount of 0.3 at% or more, Zr is 15 at% or less, Hf is 10 at% or less, Sc is 30 at% or less, and the balance is made of Ti A compacting process for pressure forming the raw material powder, a sintering process for heating and sintering the compact obtained in the compacting process, and a hot working of the sintered compact obtained in the sintering process for densification It is preferable to be obtained by a manufacturing method comprising a hot working step. Furthermore, it is more preferable to provide a cold working step for cold working the sintered body after the hot working step. This is because when such a cold working step is provided, the strength of the obtained metal foil is further improved.

  By applying such a manufacturing method (sintering method) instead of a so-called melting method, even when a large amount of Va group elements and O are contained, the β-type titanium alloy is stably prevented from macroscopic segregation. can get.

<Rubber layer>
Next, the rubber layer will be described.
In the hose of the present invention, the rubber layer is fixed to the refrigerant barrier layer. It is preferable that the refrigerant barrier layer is on the inner side and the rubber layer is laminated and fixed on the outer side. As a method of fixing the refrigerant barrier layer and the rubber layer, for example, an adhesive can be used, and a method of bonding by combining a primer and an overcoat adhesive is preferable.

  The kind of rubber constituting the rubber layer in the hose of the present invention is not particularly limited. Specifically, a rubber having good refrigerant permeation resistance and flexibility is preferably exemplified. More specifically, for example, polar such as butyl rubber (IIR), chlorinated butyl rubber (Cl-IIR), brominated butyl rubber (Br-IIR), ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), etc. Unfunctionalized rubber, acrylonitrile butadiene rubber (NBR), chlorosulfonated polyethylene rubber (CSM), chloroprene rubber (CR), butyl rubber (IIR), hydrogenated NBR (HNBR), isomonoolefin and p-methylstyrene And a copolymer rubber halide (BIMS).

The thickness of the rubber layer is not particularly limited, but can be about 0.5 to 7.0 mm.
Further, the rubber layer may be formed of one layer or a plurality of layers.

Moreover, it is preferable that a rubber layer is an aspect which laminates | stacks two rubber layers on both sides of a reinforcement layer. That is, the rubber layer is preferably an embodiment in which an inner rubber layer, a reinforcing layer, and an outer rubber layer are laminated.
Each layer in this embodiment will be described.

<Inner rubber layer>
The type of rubber constituting the inner rubber layer is not particularly limited, but specifically, it is easy to design a rubber permeation resistant and flexible rubber, or a vulcanized adhesive formulation with good high-temperature adhesion to the reinforcing layer. Rubber is preferably exemplified.

  Specific examples of such rubber include butyl rubber (IIR), chlorinated butyl rubber (Cl-IIR), brominated butyl rubber (Br-IIR), ethylene-propylene rubber (EPM), and ethylene-propylene-diene rubber. (EPDM) or other non-polar functional group rubber, acrylonitrile butadiene rubber (NBR), chlorosulfonated polyethylene rubber (CSM), hydrogenated NBR (HNBR), copolymer rubber of isomonoolefin and p-methylstyrene And halides (BIMS).

The thickness of the inner rubber layer is not particularly limited, but is preferably about 0.5 to 4.0 mm, for example, because it tends to effectively improve the caulking property of the hose.
The inner rubber layer may be formed of one layer or a plurality of layers.

<Reinforcing layer>
The reinforcing layer may be formed in a blade shape or a spiral shape. Specifically, for example, a wire blade layer or a reinforcing layer is wound with a blade or a two-layer spiral in the opposite direction. Examples thereof include those wound, and those in which the inner rubber layer is interposed between two spiral windings in opposite directions. A reinforcing layer formed by braiding reinforcing yarns such as aramid fibers and polyester fibers is preferable because the hose of the present invention is excellent in flexibility.
The reinforcing layer may be formed of one layer or a plurality of layers.

<Outer rubber layer>
It is preferable to provide an outer rubber layer made of a rubber material as the outermost layer of the hose of the present invention. The type of rubber constituting the outer rubber layer is not particularly limited. Specifically, for example, chloroprene rubber (CR), butyl rubber (IIR), chlorosulfonated polyethylene rubber (CSM), ethylene- Examples include propylene rubber (EPM) and ethylene-propylene-diene rubber (EPDM).

Although the thickness of the said outer side rubber layer is not specifically limited, For example, it can be set as about 0.5-3.0 mm.
The outer rubber layer may be formed of one layer or a plurality of layers.

<Specific Embodiment of Hose of the Present Invention>
Next, the structure of the hose of the present invention will be specifically described. The hose of the present invention only needs to have a layer structure having at least a refrigerant barrier layer and a rubber layer. For example, the hose has a refrigerant barrier layer and a rubber layer, and the rubber layer is an inner rubber layer, a reinforcing layer, and an outer rubber layer. The hose comprised from can be mentioned. In this case, each layer and the reinforcing layer may be formed of one layer or may be formed of a plurality of layers.

Next, the hose of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing each layer of a hose that is a preferred embodiment of the hose of the present invention. The hose 1 has a refrigerant barrier layer 2, and has an inner rubber layer 3, a reinforcing layer 4, and an outer rubber layer 5 on the upper layer. As shown in FIG. 1, the rubber layer may have a three-layer structure in which the reinforcing layer 4 is sandwiched between the inner rubber layer 3 and the outer rubber layer 5, or may have an aspect without the reinforcing layer 4. Moreover, you may have another layer.

<Method of manufacturing hose>
The manufacturing method of the hose of this invention is not specifically limited. For example, a metal foil manufactured by the above method is vertically wound around the outer periphery of the mandrel (a tape-like laminate sheet having a width that can wrap around the hose is attached parallel to the axial direction of the hose so as to form a cylindrical shape without a gap. Then, after forming a refrigerant barrier layer and applying an adhesive on the upper surface, the rubber composition is extruded using a rubber crosshead die type extruder to form a rubber layer. .

(Adjustment of refrigerant transport hose)
<Example 1>
On the outer periphery of a mandrel having a diameter of 6 mm to which a release agent has been applied in advance, a tensile elastic modulus: 50 GPa, a tensile strength: 1.0 GPa, an elastic deformability: 2.5%, a 20 μm-thick β-type titanium alloy foil (rubber metal ( (Registered trademark), manufactured by Toyota Central Research Laboratories Co., Ltd.) was vertically wound to form a refrigerant barrier layer. The tensile modulus, tensile strength, and elastic deformability are values obtained by a method based on JIS-K7113. Here, a specimen obtained by cutting a β-type titanium foil into a No. 2 dumbbell shape was used. The tensile speed was 50 mm / min.
Next, Chemlok205 (manufactured by Lord Corporation) is applied and dried on the refrigerant barrier layer to form a film having a thickness of about 25 μm, and then Chemlok6108 (manufactured by Lord Corporation) is applied and dried to obtain a thickness. A film of about 25 μm was made.
Next, the HNBR rubber composition was extruded thereon using a rubber crosshead die type extruder to form an inner rubber layer having a thickness of 1.6 mm. The composition of the HNBR rubber composition is shown in Table 1.
Next, a reinforcing material made of aramid yarn was braided on the inner rubber layer (1500d, 80 pieces) to form a reinforcing layer.
Next, an EPDM rubber composition was extruded on the reinforcing layer using a rubber crosshead die type extruder to form an outer rubber layer having a thickness of 1.2 mm. The composition of the EPDM rubber composition is shown in Table 1.
And after vulcanizing at 150 degreeC, the mandrel was extracted and the hose A for refrigerant | coolant transport was created.

<Example 2>
Tensile elastic modulus: 70 GPa, tensile strength: 1.5 GPa, elastic deformability: 2.5%, and using a β-type titanium alloy foil having a thickness of 20 μm, the same as in Example 1, and a refrigerant transport hose B was created.

<Comparative Example 1>
Tensile elastic modulus: 80 GPa, tensile strength: 0.6 GPa, elastic deformability: 0.5%, except that an aluminum foil having a thickness of 20 μm was used, a refrigerant transport hose C was prepared in the same manner as in Example 1. did.

(Hose deformation test)
The straight hose was bent 180 degrees U-shaped (R = 60 mm) and then returned to the original straight state five times. Here, a specific part of the hose was bent. In this case, an elongation of about 4.5% is added to the metal foil in a state bent in a U shape.
Then, it was observed whether or not a crack was generated in the refrigerant barrier layer (β-type titanium alloy foil) at the site.
The results are shown in Table 2.

(Refrigerant permeation test)
A refrigerant permeation test was performed on the refrigerant transport hose before and after the hose deformation test.
The refrigerant permeation test was performed using HFC134a as a refrigerant, and using the hose gas permeation measuring method and measuring device described in JP-A-2001-349801 before and after the hose deformation test. That is, two 50 cm long hoses with metal fittings attached to both ends of the hose are prepared, heated in advance at 70 ° C. for 4 hours, and one hose is connected to a reservoir tank to reach 5.5 MPa at 20 ° C. Until the refrigerant was sealed. The other hose was sealed without enclosing the refrigerant. And the gas permeation amount was computed by measuring the mass after 72 hours at 120 degreeC, and refrigerant | coolant permeation resistance was investigated.
The results are shown in Table 2.

FIG. 1 is a perspective view of a preferred embodiment of the hose of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hose of this invention 2 Refrigerant barrier layer 3 Inner rubber layer 4 Reinforcement layer 5 Outer rubber layer

Claims (3)

A hose for transporting refrigerant having at least a refrigerant barrier layer and a rubber layer,
The refrigerant transport hose, wherein the refrigerant barrier layer is a metal foil having a tensile modulus of 70 GPa or less, a tensile strength of 1 GPa or more, and an elastic deformability of 2.5% or more. The refrigerant transport hose according to claim 1, wherein the metal foil is made of a β-type titanium alloy having a composition represented by Ti ₃ (Nb, Ta, V) + (Zr, Hf, Sc) + O.   The method for manufacturing a refrigerant transport hose according to claim 1, comprising a step of forming a rubber layer on an outer surface of the coolant barrier layer.

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