JP2005315406A - Hose for transporting refrigerant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hose for transporting a refrigerant having superior gas barrier property, and further having superior dynamic durability such as impulse-proof performance, and flexibility. <P>SOLUTION: This hose for transporting the refrigerant has a resin layer mainly composed of polyamide applying metaxylene diamine as constitutional unit. Preferably, this hose for transporting the refrigerant has a stacked resin layer 1 formed by stacking a first resin layer 1a mainly composed of polyamide 6 as an innermost layer, and a second resin layer 1b mainly composed of polyamide applying metaxylene diamine as constitutional unit and stacked on an outer periphery of the innermost layer. The first resin layer 1a carries dynamic durability and flexibility, and the second resin layer 1b carries gas barrier property. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a refrigerant transport hose suitable as a piping hose for an automobile car cooler, an air conditioner, etc., and in particular, a refrigerant excellent in gas barrier properties (refrigerant permeation resistance) and excellent in dynamic durability and flexibility. It relates to a transport hose.

  Refrigerant transport hoses used for piping and the like of automobile air conditioners are roughly classified into high pressure lines and low pressure lines. The high-pressure line is a line that supplies high-temperature refrigerant compressed into a gas-liquid mixture by a compressor to the condenser at high pressure. The low-pressure line is a line for returning the low-pressure / low-temperature refrigerant evaporated by the evaporator to the compressor.

  The refrigerant transport hose has excellent gas barrier properties that can reliably prevent the leakage of refrigerant (Freon), flexibility to ensure the routing of the refrigerant transport hose in narrow spaces, and durability Properties such as aging resistance, impact resistance, and mechanical strength are required, but especially for gas barrier properties, the amount of refrigerant leakage in the high-pressure line is significant due to its mechanism, so high gas barrier properties are required. It has been.

  In order to ensure gas barrier properties and flexibility, the conventional refrigerant transport hose has an innermost layer made of a composite resin obtained by adding a polyolefin as a flexibility-imparting agent to a polyamide-based resin such as polyamide 6 (nylon 6). It is arranged as a gas barrier layer and has a multilayer structure in which a rubber layer is coated on the outer periphery. In the innermost layer, although the flexibility is improved by blending the polyolefin, the gas barrier property of the polyolefin itself is inferior to that of polyamide, and as a result, the gas barrier property of the innermost layer made of the composite resin is impaired.

  Therefore, in order to solve this problem, the present applicant firstly used a refrigerant transport hose excellent in gas barrier properties and flexibility, in which the innermost layer was polyamide 6:58 to 72 parts by weight and polyolefin: 42 to 28 parts by weight. Proposal of a refrigerant transport hose consisting of a resin layer with a sea-island structure in which the sea phase is polyamide 6, the island phase is polyolefin, and the polyamide 6 is dispersed in a dispersed manner in the polyolefin island phase (Japanese Patent Laid-Open No. 2000-120944).

In this refrigerant transport hose, since the innermost resin layer has the polyamide 6 phase scattered in the form of scattered dots in the polyolefin island phase, the polyolefin island phase is present inside the original volume of the polyolefin. The apparent volume fraction increases by the amount of the polyamide 6 phase. Thus, when the apparent volume fraction of the island phase of polyolefin becomes large, the improvement effect of the softness | flexibility provision effect similar to the case where the compounding quantity of polyolefin is increased is acquired. For this reason, the blending amount of the actual polyolefin can be kept low, and therefore a good flexibility improvement effect can be obtained without causing a decrease in gas barrier properties due to the blending of the polyolefin.
JP 2000-120944 A

  However, even the refrigerant transport hose disclosed in Japanese Patent Application Laid-Open No. 2000-120944 cannot be said to have sufficient gas barrier properties, particularly in high-pressure line applications, and further improvements are required.

  An object of the present invention is to provide a refrigerant transport hose which is excellent in gas barrier properties and also excellent in dynamic durability such as impulse resistance and flexibility.

  The refrigerant transport hose of the present invention is characterized by having a resin layer mainly composed of polyamide having meta-xylenediamine as a structural unit.

  In order to further improve the gas barrier property of the conventional refrigerant transport hose, the present inventor has paid particular attention to a polyamide made of metaxylenediamine having excellent gas barrier performance. However, the polyamide made of meta-xylenediamine is excellent in gas barrier performance, but the material itself is very hard, so it has sufficient durability performance such as impulse resistance after long-term heat aging and vibration durability test required for a hose. I found out that I could not be satisfied. That is, the required properties cannot be satisfied only by replacing the innermost polyamide 6 made of a composite resin of polyamide 6 and polyolefin with a polyamide made of metaxylenediamine. Therefore, the present inventors provide a layer mainly composed of a polyamide (hereinafter sometimes referred to as “polyamide MX”) having metaxylenediamine having excellent gas barrier properties as a gas barrier layer, and further serving as an innermost layer. The present invention has been completed by finding that the above-mentioned problems can be solved by providing a resin layer having flexibility and dynamic durability.

  In the present invention, in particular, the first resin layer mainly composed of polyamide 6 is used as the innermost layer, and the second resin layer mainly composed of polyamide containing metaxylenediamine as a constituent unit is laminated on the outer periphery of the innermost layer. It is preferable to have a laminated structure, and thereby to realize a refrigerant transport hose that has excellent durability performance such as impulse resistance after long-term thermal aging, vibration durability test after impulse test, and gas barrier performance. Can do.

  In the present invention, the first resin layer and the second resin layer may have an alternately laminated structure.

  In the present invention, the first resin layer preferably has a thickness of 50 to 500 μm, and the second resin layer preferably has a thickness of 10 to 200 μm. Moreover, it is preferable that the 1st resin layer and the 2nd resin layer are integrally molded by co-extrusion.

  The first resin layer contains polyamide 6:58 to 72 parts by weight and polyolefin: 42 to 28 parts by weight (however, the total of polyamide 6 and polyolefin is 100 parts by weight), and the sea phase is. It is preferably polyamide 6 and has an island-island structure in which the island phase is polyolefin and the polyamide 6 is dispersed in the form of dots in the island phase of the polyolefin.

  Further, the second resin layer may be composed only of polyamide having meta-xylenediamine as a structural unit, but may also include polyamide having a structural unit of metaxylenediamine and polyolefin. good. When the second resin layer includes a polyamide having a structural unit of metaxylenediamine and a polyolefin, in particular, the sea phase is a polyamide having a structural unit of metaxylenediamine, the island phase is a polyolefin, and It is preferable that the island phase has a sea-island structure in which polyamide is dispersed in the form of dots.

  ADVANTAGE OF THE INVENTION According to this invention, the hose for refrigerant | coolant transport excellent in gas barrier property, a softness | flexibility, and durability is provided.

  Embodiments of the refrigerant transport hose of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an embodiment of the refrigerant transport hose of the present invention. FIGS. 2A and 2B are perspective views showing another embodiment of the laminated resin layer of the refrigerant transport hose according to the present invention.

  The refrigerant transport hose 10 of FIG. 1 is configured by covering an inner tube layer 3 composed of a laminated resin layer 1 and an inner tube rubber layer 2 with an outer rubber 5 via an intermediate rubber layer 4 including a reinforcing thread. Yes. Note that an adhesive layer may be provided between the laminated resin layer 1 and the inner tube rubber layer 2 as necessary.

  The laminated resin layer 1 is composed of an innermost first resin layer 1a mainly responsible for durability and flexibility, and a second resin layer 1b mainly responsible for gas barrier properties laminated on the outer periphery thereof.

  The first resin layer 1a preferably contains polyamide 6:58 to 72 parts by weight and polyolefin: 42 to 28 parts by weight (however, the total of polyamide 6 and polyolefin is 100 parts by weight). A polyolefin island phase is dispersed in the sea phase, and a polyamide 6-polyolefin composite resin having a structure in which polyamide 6 is dispersed in the island phase of the polyolefin in the form of dots. Here, when the polyamide 6 of the polyamide 6-polyolefin composite resin is less than 58 parts by weight, the gas barrier property is inferior even if the morphology of the specific sea-island structure is used. On the other hand, when the amount of polyamide 6 is more than 72 parts by weight, even if it is a morphology of the specific sea-island structure, the flexibility is inferior.

  Even if the polyamide 6-polyolefin composite resin is in the composition range of the specific polyamide 6-polyolefin, good gas barrier properties and flexibility can be obtained when the specific sea-island structure morphology is not exhibited. Can not. In order to achieve the best gas barrier properties and flexibility, particularly for polyamide 6 (the total of polyamide 6 constituting the sea phase and the polyamide 6 phase existing in the form of scattered dots in the island phase of polyolefin). It is preferable that the ratio of the polyamide 6 phase existing in the form of dots in the island phase of the polyolefin (hereinafter, the ratio is referred to as “scattered dispersion”) is about 2.5 to 30% by weight. If this proportion is less than 2.5% by weight, the above-mentioned effect due to the presence of the polyamide 6 phase in the form of scattered dots in the polyolefin island phase cannot be sufficiently obtained. Conversely, if it exceeds 30% by weight, The polyamide 6 phase as the sea phase is too small and the gas barrier property may be lowered.

  The size of the polyolefin island phase and the size of the polyamide 6 phase in the polyolefin island phase are approximately 0.4 to 1.5 microns for the polyolefin island phase and 0. It is preferable that it is about 05-0.5 micron.

  In addition, as polyolefin, modified EPR (ethylene-propylene copolymer), modified EPDM (ethylene-propylene-diene terpolymer), ionomer, α-olefin copolymer, modified IR (isoprene rubber), modified SEBS. (Styrene-ethylene-butylene-styrene copolymer), halogenated isobutylene-paramethylstyrene copolymer, ethylene-acrylic acid modified product, and a mixture containing these as a main component.

  Additives such as anti-aging agents and oxidative degradation agents may be added to the polyamide 6-polyolefin composite resin constituting the innermost layer, if necessary.

In addition, as a method of forming the morphology of the specific sea-island structure of the polyamide 6-polyolefin composite resin,
(1) A method in which polyamide 6 and polyolefin are kneaded at a predetermined mixing ratio to form a master batch, and then the master batch and polyamide 6 are kneaded.
(2) A method of melt-kneading polyamide 6 and a polyolefin blend by high shear.
Etc.

  The polyamide MX, which is the main component of the second resin layer 1b, that is, a metaxylenediamine of polyamide having metaxylenediamine as a structural unit is represented by the following structural formula, for example.

  In the present invention, the polyamide MX may be a homopolymer composed only of such metaxylenediamine, or may be a copolymer of metaxylenediamine and another monomer. In the case of a copolymer, metaxylenediamine is preferably contained in an amount of 60% by weight or more.

  In the present invention, the second resin layer 1b may be composed only of such polyamide MX, and in this case, remarkably excellent gas barrier properties can be obtained in the second resin layer. Further, the second resin layer 1b may be made of a polymer alloy by adding such a polyamide MX as a main component and adding other components, for example, a polyolefin acting as a flexibility-imparting agent.

  Here, as the polyolefin used for the second resin layer 1b, modified EPR (ethylene-propylene copolymer), modified EPDM (ethylene-propylene-diene terpolymer), ionomer, α-olefin copolymer. Modified IR (isoprene rubber), modified SEBS (styrene-ethylene-butylene-styrene copolymer), halogenated isobutylene-paramethylstyrene copolymer, ethylene-acrylic acid-modified product, ethylene-ethyl acrylate copolymer, and Examples thereof include acid-modified products and mixtures containing them as main components.

  Polyolefins, especially those modified with acid anhydrides such as maleic anhydride, alkyl acrylate esters such as glycidyl methacrylate, epoxies, and modified products thereof, can obtain a fine alloy structure based on polyamide. It is possible and preferable.

  When the second resin layer 1b is composed of a polyamide MX-polyolefin composite resin, the gas barrier property is lowered when the polyolefin content in the second resin layer 1b is too large, so that the second resin layer is configured. The content in the polyamide MX-polyolefin composite resin is preferably 40% by weight or less, particularly preferably 30% by weight or less. When the content of the polyolefin in the polyamide MX-polyolefin composite resin exceeds 40% by weight, the sea phase and the island phase are reversed in the sea-island structure described later, and the gas barrier property is remarkably lowered. However, since the polyolefin content in the polyamide MX-polyolefin-based composite resin constituting the second resin layer is too small, the effect of improving the flexibility and durability due to the blending of the polyolefin cannot be sufficiently obtained. For example, it is preferably 10% by weight or more, particularly 20% by weight or more.

  When a modified polyolefin such as acid-modified polyolefin is used as the polyolefin, a large amount of the resin causes gelation of the resin, and when extruding, it causes poor appearance such as rough skin (fisheye). When used, the content in the polyamide MX-polyolefin-based composite resin constituting the second resin layer is preferably 30% by weight or less, for example, 5 to 25% by weight.

  Thus, by blending polyolefin with polyamide MX, flexibility and durability are improved, but a decrease in gas barrier properties is inevitable. However, by adopting a fine alloy structure of polyamide MX and polyolefin, in particular, the island phase of polyolefin is dispersed in the sea phase of polyamide MX and the polyamide MX is dispersed in the form of dots in the island phase of polyolefin. With such a structure, a decrease in gas barrier properties due to blending of polyolefin can be suppressed, which is preferable.

  In particular, the ratio of the polyamide MX phase existing in the form of dots in the island phase of the polyolefin to the polyamide MX (the total of the polyamide MX constituting the sea phase and the polyamide MX phase existing in the form of dots in the island phase of the polyolefin) (Hereinafter, the ratio is referred to as “scattered dispersion”.) Is preferably about 2.5 to 30% by weight. If this proportion is less than 2.5% by weight, the effect of having the polyamide MX phase present in the form of scattered dots in the polyolefin island phase cannot be sufficiently obtained. As a result, the gas barrier property may be lowered due to too little polyamide MX phase.

  The size of the polyolefin island phase and the size of the polyamide MX phase in the polyolefin island phase are approximately 0.4 to 1.5 μm in the size of the polyolefin island phase and 0.05 in the size of the polyamide MX phase. It is preferable that it is about -0.5 micrometer.

  The polyamide in the second resin layer of the present invention does not necessarily need to be polyamide MX, and may contain a polyamide such as polyamide 6 other than polyamide MX. It is preferable for ensuring the gas barrier property that 51% by weight or more of the total polyamide component in the resin layer is a metaxylenediamine component.

  Moreover, you may add additives, such as an anti-aging agent and an oxidation degradation agent, to resin which comprises the 2nd resin layer as needed.

The polyamide MX-polyolefin-based composite resin resin, in particular, the polyamide-based composite resin having a sea-island structure as described above can be produced, for example, by the following method (1) or (2).
(1) A method in which polyamide MX and polyolefin are kneaded at a predetermined blending ratio to form a master batch, and then the master batch and polyamide MX are kneaded.
(2) A method of melt-kneading polyamide MX and a polyolefin blend by high shear.

  In the laminated resin layer 1 of the refrigerant transport hose 10 of FIG. 1, the thickness of the resin layer mainly composed of polyamide 6 as the first resin layer is preferably as thick as possible in terms of durability of the hose. On the other hand, when the film thickness increases, the flexibility of the hose is sacrificed. Therefore, the thickness of the first resin layer is preferably 50 to 500 μm, particularly 100 to 300 μm.

  On the other hand, the film thickness of the second resin layer composed of polyamide MX or having polyamide MX as the main component is preferably as thick as possible in terms of gas barrier performance. A great sacrifice of durability and durability. Accordingly, the thickness of the second resin layer is preferably 10 to 200 μm, particularly 20 to 100 μm.

  In the present invention, the laminated resin layer 1 composed of the first resin layer and the second resin layer is not necessarily composed of the first resin layer 1a and the second resin layer 1b as shown in FIG. It is not necessary to have a two-layer laminated structure in which layers are laminated one by one, and the total thickness of the hose is excessively thick, so that the flexibility is not lost, the cost is not increased, and the weight is not increased. It may be a structure. For example, as shown in FIG. 2 (a), the first resin layer 1a-1, the second resin layer 1b, and the first resin layer 1a-2 are laminated in this order from the inner side, thereby forming a three-layered alternately laminated structure. There may be. 2B, from the inside, the first resin layer 1a-1, the second resin layer 1b-1, the first resin layer 1a-2, the second resin layer 1b-2, It may be a five-layered alternately laminated structure in which the first resin layers 1a-3 are laminated in this order. Further, a stacked structure having a larger number of layers may be used. In the case of a laminated structure of three or more layers, the innermost layer and the outermost layer as the laminated resin layer are preferably the first resin layer. Thus, even in the case of a multi-layered alternately laminated structure, the preferred film thickness of each resin layer is as described above, but the total film thickness of a plurality of first resin layers or second resin layers is within the above range. Thus, it is preferable that the film thickness of each layer is slightly reduced. For example, in the laminated resin layer 1A having a three-layer structure shown in FIG. 2A, the first resin layers 1a-1 and 1a-2 each have a film thickness of 200 μm, and the second resin layer 1b has a film thickness of 100 μm. It can be. Further, in the laminated resin layer 1B having a five-layer structure shown in FIG. 2B, the first resin layers 1a-1 and 1a-3 each have a thickness of 100 μm, and the film of the first resin layer 1a-2. The thickness can be 200 μm, and the thickness of each of the second resin layers 1b-1 and 1b-2 can be 50 μm.

  The laminated resin layers 1, 1 </ b> A, 1 </ b> B according to the present invention having such a multi-layer structure can be easily manufactured by integral molding by co-extrusion of these resin layers, and in this case, The first resin layer and the second resin layer are both made of polyamide as a base resin, and because they are familiar, they are firmly bonded by co-extrusion. There is no need to perform any processing.

  There is no restriction | limiting in particular about the other structure of the refrigerant | coolant transport hose of this invention, The structure of the normal refrigerant | coolant transport hose is employable.

  For example, in the refrigerant transport hose 10 shown in FIG. 1, as the rubber constituting the inner tube rubber layer 2 and the jacket rubber 5, generally butyl rubber (IIR), chlorinated butyl rubber (C1-IIR), chlorinated polyethylene, chloro Sulfonated polyethylene, brominated butyl rubber (Br-IIR), isobutylene-bromoparamethylstyrene copolymer, EPR (ethylene-propylene copolymer), EPDM (ethylene-propylene-diene terpolymer), NBR (acrylonitrile) Butadiene rubber), CR (chloroprene rubber), hydrogenated NBR, acrylic rubber, blends of two or more of these rubbers, or blends with polymers based on these rubbers, preferably butyl rubber, EPDM System rubber is used. These rubbers can be applied with compounding recipes such as commonly used fillers, processing aids, anti-aging agents, vulcanizing agents, and vulcanization accelerators.

  The rubber type of the inner rubber layer 2 and the rubber type of the jacket rubber 5 may be the same type or different types.

  Moreover, the rubber | gum of the intermediate | middle rubber layer 4 should just have the adhesiveness with the inner tube | pipe rubber layer 2 and the jacket rubber 5, and there is no restriction | limiting in particular.

  The reinforcing system is not particularly limited as long as it is normally used. In general, polyester, wholly aromatic polyester, nylon, vinylon, rayon, aramid, polyarylate, polyethylene naphthalate and blended yarns thereof are used.

  The thickness of the inner tube rubber layer 2 is preferably about 0.8 to 4 mm from the viewpoint of flexibility. Furthermore, it is preferable that the thickness of the intermediate rubber layer 4 including the reinforcing yarn is about 0.5 to 5 mm, and the thickness of the outer rubber layer 5 is about 1 to 2 mm.

  Such a refrigerant transport hose of the present invention is manufactured by extruding and laminating the material of each constituent layer to a predetermined thickness on a mandrel and vulcanizing at 140 to 170 ° C. for 30 to 120 minutes according to a conventional method. can do.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

  The rubber ratios of the inner rubber layer, the intermediate rubber layer, and the outer rubber layer used in the following examples and comparative examples are as shown in Tables 1 to 3 below.

Example 1
The refrigerant transport hose having the configuration shown in FIG. 1 was manufactured by the following procedure.

  On a mandrel having a diameter of 11 mm, 72 parts by weight of polyamide 6 (“1022B” manufactured by Ube Industries, Ltd.) and 28 parts by weight of polyolefin (“Tuffmer MH5010” manufactured by Mitsui Petrochemical Co., Ltd.) were melt-kneaded and pelletized. And a polyamide MX (MX nylon “P6001” manufactured by Mitsubishi Gas Chemical Co., Ltd.) are coextruded to form a first resin layer 1a mainly composed of a polyamide 6 having a thickness of 100 μm and a polyamide having a thickness of 50 μm. After forming the laminated resin layer 1 with the second resin layer 1b made of MX, the inner layer rubber shown in Table 1 was extruded to a thickness of 1.2 mm. On top of this, 24 3,000 denier polyester reinforcing yarns were aligned and wound in a spiral shape, and the intermediate rubber shown in Table 2 was extruded to a thickness of 0.3 mm on this reinforcing yarn layer. Further, 3000 denier polyester was further formed thereon. Twenty-four reinforcing yarns were aligned and wound in a spiral shape in the opposite direction. Next, the jacket rubber shown in Table 3 was extruded to a thickness of 1.3 mm and vulcanized at 150 ° C. for 90 minutes to obtain a refrigerant transport hose.

  About the obtained refrigerant transport hose, the flexibility, dynamic durability and gas barrier property were investigated by the following methods, and evaluated as excellent (◎), good (○), normal (△), and defective (×), and the result Are shown in Table 4.

  In addition, the polyamide 6-polyolefin-based composite resin of the first resin layer (hereinafter, this resin blend is referred to as “blend A”) has a polyolefin island phase dispersed in the sea phase of polyamide 6 and the polyolefin island phase. The polyamide 6 was dispersed in the form of scattered dots having a dispersed particle size of 0.5 to 1.5 μm, and the dispersed ratio of scattered dots obtained from a transmission electron microscope image was 5.1% by weight.

[Flexibility test]
The load was measured when the hose was wound around a mandrel having a radius of 100 mm by a half turn.

[Dynamic durability test]
After enclosing PAG oil inside and preliminarily aging at 130 ° C for 30 days, attach the hose upside down with a mounting span of 270 mm, and perform the following repeated pressurization using PAG oil as a medium, The inner surface state after 150,000 rotations was observed.
Atmospheric temperature: 130 ° C
Pressure: 0.1 MPa to 3.5 MPa
Pressure cycle: 15 cpm
Number of times: 150,000 times

[Gas barrier property test]
Refrigerant HFC134a was sealed in a hose at 0.6 g / cm ³ and the amount of weight loss when left at 90 ° C. for 96 hours was measured as the refrigerant permeation amount.

Examples 2 and 3
In Example 1, a refrigerant transport hose was manufactured in the same manner except that the film thicknesses of the first resin layer and the second resin layer were as shown in Table 4, and evaluated in the same manner. It is shown in Table 4.

Example 4
In Example 1, the first resin layer was not formed, only the second resin layer was formed, and the refrigerant transport hose was manufactured in the same manner except that the film thickness was as shown in Table 4. Similarly, Evaluation was performed and the results are shown in Table 4.

Example 5
As shown in FIG. 2 (a), the resin layer by coextrusion was a laminated resin layer 1A having a three-layer structure of the above blend A / the following blend B / the blend A, and the thickness of each layer was as shown in Table 4. Except for the above, a refrigerant transport hose was produced in the same manner as in Example 1, and evaluated in the same manner. The results are shown in Table 4.
Formulation B: Polyamide MX (Mitsubishi Chemical Co., Ltd. “S6001”) 80% by weight and polyolefin (Mitsui Chemicals Co., Ltd. “Toughmer MH5010”) 20% by weight were kneaded with the polyamide MX sea phase. Resin in which the island phase is dispersed, the dispersed particle diameter is 0.5 to 1.5 μm, and the scattered dispersion is 5.1% by weight.

Comparative Example 1
In Example 1, a refrigerant transport hose was produced in the same manner except that the second resin layer was not formed and only the first resin layer 1a-1 was used. This is shown in FIG.

  From Table 4, it can be seen that the refrigerant transport hose of the present invention exhibits excellent gas barrier properties, particularly in the case of being compatible with high-pressure lines, and is excellent in flexibility and dynamic durability.

It is a perspective view which shows embodiment of the hose for refrigerant | coolant transportation of this invention. It is a perspective view which shows other embodiment of the laminated resin layer of the hose for refrigerant | coolant transport which concerns on this invention.

Explanation of symbols

1, 1A, 1B Laminated resin layer 1a First resin layer 1b Second resin layer 2 Inner tube rubber layer 3 Inner tube layer 4 Intermediate rubber layer 5 Outer rubber 10
Refrigerant transport hose

Claims (9)

  A refrigerant transport hose comprising a resin layer composed mainly of polyamide having meta-xylenediamine as a structural unit.   In Claim 1, the 1st resin layer which has polyamide 6 as a main component is made into innermost layer, and the 2nd resin layer which has as a main component the polyamide which has metaxylenediamine as a structural unit is laminated | stacked on the outer periphery of this innermost layer. A refrigerant transport hose characterized by having a laminated structure.   3. The refrigerant transport hose according to claim 2, wherein the refrigerant transport hose has an alternately laminated structure of a first resin layer and a second resin layer.   4. The refrigerant transport hose according to claim 2, wherein the first resin layer has a thickness of 50 to 500 [mu] m, and the second resin layer has a thickness of 10 to 200 [mu] m.   The refrigerant transport hose according to any one of claims 2 to 4, wherein the first resin layer and the second resin layer are integrally formed by coextrusion.   The first resin layer according to any one of claims 2 to 5, wherein the first resin layer includes 58:72 parts by weight of polyamide 6 and 42-28 parts by weight of polyolefin (provided that the total of polyamide 6 and polyolefin is 100). The sea phase is polyamide 6, the island phase is polyolefin, and the island phase of the polyolefin has a sea-island structure in which polyamide 6 is dispersed in the form of dots. A refrigerant transport hose.   The refrigerant transport hose according to any one of claims 1 to 6, wherein the second resin layer is made of polyamide having metaxylenediamine as a structural unit.   The refrigerant transport hose according to any one of claims 1 to 6, wherein the second resin layer includes a polyamide having a structural unit of metaxylenediamine and a polyolefin.   9. The second resin layer according to claim 8, wherein the sea phase is a polyamide having meta-xylenediamine as a structural unit, the island phase is a polyolefin, and the polyamide is dispersed in a dispersed manner in the island phase of the polyolefin. A refrigerant transport hose having a sea-island structure configured as described above.

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