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CN-121993667-A - Multi-layer tube for an air conditioning system of a motor vehicle

CN121993667ACN 121993667 ACN121993667 ACN 121993667ACN-121993667-A

Abstract

A tube (10) for an air conditioning system of a motor vehicle, the tube comprising an inner tube (12) located at a radially inner position and configured to carry a fluid to be delivered, wherein the inner tube (12) is made of one of PA6/66, PA6T/6 or EX1, an outer tube (14) located at a radially outer position, wherein the outer tube (14) is made of a polyamide having a ratio of the number of methylene CH 2 to the number of amide groups CONH in the macromolecular repeat unit of greater than or equal to 8, wherein EX1 is a reactive thermoplastic composition comprising a continuous phase of at least one thermoplastic polymer, and a discontinuous phase based on at least one reactivity enhancing chemical dispersed in the continuous phase.

Inventors

  • Katya Rosie
  • Giuseppe Parent
  • Florence Erro

Assignees

  • 哈特奇桑有限公司

Dates

Publication Date
20260508
Application Date
20251110
Priority Date
20241108

Claims (12)

  1. 1. A tube (10) for an automotive vehicle air conditioning system, the tube comprising: an inner tube (12) located at a radially inner position and configured to carry a fluid to be delivered, wherein the inner tube (12) is made of one of the materials PA6/66, PA6T/6 or EX1, -An outer tube (14) in a radially external position, wherein the outer tube (14) is made of polyamide having a ratio of the number of methylene CH 2 to the number of amido CONH in the macromolecular repeat unit of greater than or equal to 8; Wherein EX1 is the following material: A reactive thermoplastic composition comprising a continuous phase based on at least one thermoplastic polymer, and a discontinuous phase based on at least one reactivity enhancing chemical dispersed in the continuous phase, wherein the reactivity enhancing chemical is capable of being incompatible with the at least one thermoplastic polymer, and wherein the enhancing chemical is selected from the group consisting of epoxy resins, polyorganosiloxanes having SiH functional groups, diisocyanates or polyisocyanates, and mixtures thereof, wherein the thermoplastic composition is free of any compatibilizing agent between the continuous phase and the discontinuous phase, and comprises the product of an in situ grafting, branching and/or crosslinking reaction, wherein the product is obtained by reactive mixing of the continuous phase and the discontinuous phase at a shear rate of greater than 10 2 s -1 , the product of an in situ reaction between the reactivity enhancing chemical and polymer chains of the at least one thermoplastic polymer being such that the polymer chains of the at least one thermoplastic polymer have a grafted, branched or crosslinked structure, and the discontinuous phase is homogeneously dispersed in the continuous phase.
  2. 2. The tube according to claim 1, wherein the outer tube (14) is made of one of the following materials PA610, PA612, PA12, PA11, PA1012 or PA10T.
  3. 3. The tube according to claim 1 or 2, wherein the inner tube (12) is made of PA 6/66.
  4. 4. Tube according to claim 1 or 2, wherein the inner tube (12) is made of EX 1.
  5. 5. Tube according to claim 4, wherein the inner tube (12) is made of a material called EX 2: The EX1 material, wherein the at least one thermoplastic polymer is selected from homopolymers and copolymers of olefins, aliphatic polyamides of polyphthalamides, semiaromatic polyamides of polyphthalamides and aromatic polyamides of polyphthalamides, polyimides (PI), polyamide-imides (PAI), polyetherimides (PEI), thermoplastic elastomers (TPE), polyphenylsulfone, polyethersulfone (PES), polystyrene (PS), polysulfone (PSU), polyesters, polyethylene oxides and other olefin-based monomers, polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK), block copolymers thereof, and mixtures thereof.
  6. 6. The tube according to any one of the preceding claims, comprising at least one intermediate tube (16), said intermediate tube (16) being radially interposed between said inner tube (12) and said outer tube (14).
  7. 7. The tube according to claim 6, wherein the intermediate tube (16) is made of EVOH.
  8. 8. A tube according to any one of the preceding claims, wherein the thickness of the inner tube (12) is greater than the thickness of the outer tube (14).
  9. 9. Tube according to claim 5, wherein the inner tube (12) is made of a material called EX 3: the EX2 material, wherein the discontinuous phase is based on at least one epoxy resin and preferably an amide crosslinking system with or without an acrylated amide blocking agent or a methacrylated amide blocking agent, wherein the continuous phase is selected from the group consisting of polyphthalamide aliphatic polyamides, polyphthalamide semi-aromatic polyamides and polyphthalamide aromatic polyamides.
  10. 10. An air conditioning system for a motor vehicle comprising a tube (10) according to any one of the preceding claims.
  11. 11. A motor vehicle comprising the air conditioning system of claim 10.
  12. 12. A method for manufacturing a tube (10) according to any one of claims 1 to 9, comprising the step of extruding both the inner tube (12) and the outer tube (14) simultaneously.

Description

Multi-layer tube for an air conditioning system of a motor vehicle Technical Field The present invention relates to a multilayer tube for an air conditioning system of a motor vehicle. The tube is configured to convey a fluid circulating in an air conditioning system. Background In the automotive field, pipes currently used in air conditioning systems are made of aluminium, possibly provided with rubber pipes. This solution can ensure the product function but has some drawbacks due to heavy weight, poor vibration damping, generally high costs, risk of permanent deformation. Furthermore, the connection between the pipe end and the pipe must be achieved by brazing or cold deformation, which require a lot of energy. US2023/055055A1 discloses a hose for transporting a refrigerant comprising an inner layer, a reinforcing layer and an outer layer. The inner layer and the outer layer each include a thermoplastic resin composition having an islands-in-the-sea structure including a matrix containing a thermoplastic resin and domains containing an elastomer. The thermoplastic resin composition of the outer layer has a water vapor permeability coefficient of 10.0 g.mm/(m2.24h) or less than 10.0 g.mm/(m2.24h) at a temperature of 60 ℃ and a relative humidity of 100%. The thermoplastic resin composition of the inner layer has an oxygen permeability coefficient of 0.05cm3 mm/(m 2 day mmHg) or less than 0.05cm3 mm/(m 2 day mmHg) at a temperature of 21 ℃ and a relative humidity of 50%. The water vapor permeation amount of the hose is 6.0 mg/(240 h.cm 2) or less than 6.0 mg/(240 h.cm 2). The hose has a hydrofluoroolefin HFO-1234yf penetration of 170 g/(m2.72h) or less than 170 g/(m2.72h), and the hose has an outer surface with a mass of 3000g/m2 or less than 3000g/m2 per 1m 2. Disclosure of Invention It is an object of the present invention to provide a tube which overcomes the disadvantages of the prior art. According to the invention, this object is achieved by a tube having the technical features recited in the attached independent claims. In particular, these technical features allow the tube to have improved mechanical strength, maintaining its insulating properties even after bending. Another advantage is that the tube can be manufactured easily, quickly and economically while ensuring good heat insulating properties. It is to be understood that the appended claims are an integral part of the technical teaching provided in the following detailed description of the invention. In particular, the appended dependent claims define some preferred embodiments of the invention, which include some optional technical features. Further features and advantages of the invention will become apparent in the following detailed description, which is provided herein by way of non-limiting example only, with particular reference to the accompanying drawings, which are summarized below. Drawings Fig. 1 is a perspective view of a tube made in accordance with an exemplary embodiment of the present invention. Fig. 2 is a perspective view of a tube made in accordance with another exemplary embodiment of the present invention. Detailed Description Referring to the drawings, reference numeral 10 generally indicates a tube for an air conditioning system of a motor vehicle, said tube 10 comprising: An inner tube 12 located at a radially inner position and configured to carry a fluid to be delivered, wherein the inner tube 12 is based on, in particular made of, one of PA6/66, PA6T/6 or "EX1" (which will be defined later), An outer tube 14 in a radially external position, wherein the outer tube 14 is based on, in particular made of, a polyamide having a ratio of the number of methylene CH 2 to the number of amido CONH in the macromolecular repeat unit of greater than or equal to 8. For example, the tube 10 may be used in a motor vehicle, such as an automobile. In particular, the tube 10 can be applied in an air conditioning system of a motor vehicle, in particular for a high-pressure liquid line. The inner tube 12 is configured to carry a fluid to be delivered, in particular a refrigerant fluid, such as a refrigerant liquid or a refrigerant gas. The coolant fluid that can flow in the inner tube 12 may be known per se. The inner tube 12 has low permeability to gases used in the air conditioning circuit (e.g., R-1234YF, R134a, R290 or R744), thereby limiting its diffusion to the outside environment. The material PA6/66, PA6T/66 or PA6T/6 from which the inner tube 12 is made is a specific type of polyamide. Preferably, the inner tube 12 is based on PA6/66, in particular made of PA 6/66. Such materials provide a particularly satisfactory level of permeation resistance to gases used in air conditioning circuits. According to some preferred variants of the invention, the inner tube 12 is based on, in particular made of, the material defined in any one of claims 11 to 16 of patent EP2415824B1 or in any one of claims 13 to 24 of patent FR2963624B 1. For ex