MXPA99007646A - Metal tubing coated with multiple layers of polymeric materials - Google Patents

Abstract

Una tubería de metal revestida adaptada, comprende:un tubo de metal;una capa interior de un primer material polimérico unida a dicho tubo para proporcionar protección contra la corrosión. El primer material polimérico tiene una alta cristalinidad, un bajo factor de humectación de menos que 0.05, y un alto módulo de flexibilidad de al menos 100 MPa. Una capa exterior de un segundo material polimérico moldeada por extrusión alrededor de la capa interior para absorber la energía del impacto y eliminar las vibraciones mecánicas y ruidos acústicos. El segundo material polimérico tiene un alto factor de humectación de al menos 0.05 y un bajo módulo de flexibilidad de al menos 50 Mpa. El segundo material polimérico es un polímero de fases múltiples que tiene al menos un componente polímero, con una temperatura de transición a vidrio por debajo de la temperatura ambiente.

Description

METAL PIPE COATED WITH MULTIPLE LAYERS OF POLYMERIC MATERIALS • FIELD OF THE INVENTION This invention relates to metal pipe products, and more particularly, to metal pipes used in the automotive industry for applications such as brake lines, fuel lines and transmission oil cooling lines.

BACKGROUND OF THE INVENTION 15 Pipes used in automotive applications require resistance to corrosion and deterioration that will ultimately lead to the useful life of a vehicle. Also, the pipes could have resistance to abrasion consistent with an automotive environment, (ie impacts with stones and splinters). Finally, the pipes must be capable of isolating and absorbing mechanical vibrations and acoustic noise. To meet these requirements, the coating (s) protectors are usually applied to metal pipes REF .: 031095 which will be used in automotive applications. The coatings used in the industry have been • characterized in general by one or both of the following. First, a metallic substrate is deposited on the surface 5 of the stainless steel tube. Usually this is a sacrificial coating where the substrate wears out before the metal pipe. Second, a protective coating is deposited on the substrate to maintain the corrosive medium of the initiation of • 10 corrosion and to provide increased resistance against abrasion. Examples of prior materials and combinations of materials that use a substrate and / or protective layers in the automotive industry include: tin alloy and lead (an alloy of nominally lead 85% and tin 15%); paint rich in zinc on the tin and lead alloy; a zinc-aluminum alloy (consisting of 95% zinc and 5% aluminum, available under the trademark GALFAN); paint rich in aluminum on a coating of GALFA ?; electroplated zinc or zinc-nickel: PVF or PVDF over electroplated zinc; aluminum in hot bath; epoxy and nylon. These materials have been used as protectors and / or substrate layers in various combinations, but have experienced deficiencies that limit their usefulness. The prior art coating materials and methods have presented only limited resistance to deterioration and chipping of stone impacts and abrasion). Often, a shrinkable thermoplastic metal cover 5 is applied around the conventionally coated tubes to provide improved resistance to deterioration and splintering. Such methods, however, are very expensive and are not always effective. For example, shrinkable plastic metal covers have limited only 10 the ability to absorb or isolate mechanical vibrations and acoustic noises. Also, the use of shrinkable plastic metal covers prevent their use under the end assemblies or connectors, thereby exposing the end of the tube to corrosion. In order to overcome all the problems (ie, corrosion, deterioration, abrasion, chipping, stone impacts, mechanical vibration, acoustic noise) found in fluid and automotive transport pipe applications, simultaneously, properties of specific polymers can be adjusted. for the lining of the tube. Since not only polymeric material is effective in combating all problems, an effective product will take into account the relationship of polymer structures and properties, as well as the processing of materials and engineering considerations. ----- -. » . aa.-S .. a. d ^^ a ^^ te ^ A .---. . ^ t ----- »- *. > r.-. ----- ---- R - »», - »-.-L ----- W-WWW --- > ..--- l .---; --j »1 J-»? r? i - »- * ~ -. Accordingly, the present invention provides a single layer polymeric coating.

• Multiple in metal pipes, which manipulate the dynamic mechanical properties of polymeric materials 5 to achieve multiple elements against protection for metal pipes used in fluid or automotive transportation applications. By combining the unique dynamic mechanical properties of two layers of polymers, maximum effectiveness in corrosion resistance is provided and deterioration, abrasion, chipping and impact protection with stones. Moreover, the multi-layer coating of the present invention is effective to absorb impact energy and eliminate mechanical vibration and acoustic noise. fifteen BRIEF DESCRIPTION OF THE INVENTION The present invention provides an adaptation 20 of coated metal tubing. An inner layer of a first polymeric material is attached to a metal tube to provide protection against corrosion. The first polymeric material is characterized by a high crystallinity, a low wetting factor, and a high modulus of flexibility. Preferably the wetting factor is less than 0.05 and the modulus of flexibility is greater than 100 MPa. • An outer layer of a second polymeric material that rounds the inner layer absorbs the impact energy 5 and eliminates mechanical vibrations and acoustic noises. The second polymeric material has a high wetting factor and a low modulus of flexibility. Preferably, the wetting factor is greater than 0.05 and the modulus of flexibility is less than 50 MPa. He • The material of the outer layer is a multi-phase polymer having at least two polymer components. Each of these components has a different glass transition temperature, at least one of which will be below room temperature. fifteen BRIEF DESCRIPTION OF THE DRAWINGS • Figure 1 is a sectional view of a portion of a metal pipe fitting coated in accordance with the present invention; and Figure 2 is a sectional view of a pipe fitting of Figure 1 having a disassembled or cut end to facilitate connection to the end assemblies. i.

DETAILED DESCRIPTION OF THE DRAWINGS • Figure 1 illustrates a metal tube 10 coated in accordance with the present invention. The tube 10 is coated by an inner layer 12 of a first polymeric material and an outer layer 14 of a second polymeric material. The inner layer 12 is attached to the metal tube 10 and an outer layer 14 is molded by extrusion around the inner layer 12. The layers 12 and 14 are not join together through the use of an adhesive or some other bonding method. This is an advantage that the outer layer allows to be disassembled or cut to the tube ends. (figure 2), which facilitates the connection to the mounted ends or connectors. Many considerations are involved in the selection of the particular polymeric materials or blends which comprise the layers 12 and 14. The polymer of the inner layer may provide chemical resistance and prevent corrosion of the metal tube 10. The The polymer of the outer layer can absorb the impact energy as well as eliminate the mechanical vibration and acoustic noise. The polymer of the outer layer should also be treatable to be easily cut or removed or removed for end assemblies or connections. 25 The specific properties and structural attributes of particular polymers may be taken into account in order to achieve these results. For the polymer of the inner layer there is good chemical resistance, for example, it may have a high crystallinity. The high crystallinity, however, decreases the ability of a polymer to absorb the impact energy and isolate mechanical vibrations and acoustic noises. This function is provided by the polymer of the outer layer. Dynamic mechanical properties are the key • 10 in the determination of the polymer capacity of the outer layer to eliminate mechanical vibrations and acoustic noise. These dynamic mechanical properties are briefly described below: The modulus of a polymer is a function of temperature and frequency, w measured. The wetting factor of a polymer, so dw, is the ratio of the imaginary part of the modules Gw '' to the real part of the Gw 'module (the storage module). The natural frequency w0 is the lower noise frequency which can be eliminated by the mechanical system. The natural frequency w0, and the transmissibility T, of a mechanical system can be expressed as a function of the dynamic mechanical properties of polymers, as follows: ^^^^^^^ s ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^ w. = (KGo1) 1/2 M • Y T = + tan2 dw w2 / w02) G 'D7G' W) 2 + tan2 d w 1/2 where K is a model factor, M is the mass of the • 10 system, Go1 and G'w are the divided storage module of the polymer at the natural frequency w0 and the forced frequency wl, respectively, so dw is a measure of the wetting of the polymer at the forced frequency, and T is the transmissibility of the mechanical system. 15 Both dynamic and wetting modules are functions of temperature and frequency. These mechanical properties can be manipulated by adjusting the molecular structures of the polymers. In the end, a frequency vibration system can be reached lower by the reduction of the storage module of the polymer in question. In addition, the resonant tansmissibility can be suppressed by the selected polymers with high wetting factors. The inner layer 12, as stated above, is comprised of a polymeric material which is chosen for its liquid and chemical desistance. The layer 12 is attached to the outlined metal tube 10 and the corrosive medium is kept from reaching or attacking the tube 10. The polymer material selected by the layer 12 should be particularly resistant to corrosive media or fluids commonly encountered in automotive applications, such as brake fluids, machine oil and fuel. To reach the latter, the material • 10 polymeric of the inner layer 12 may have a high crystallinity and a low wetting factor. The wetting factor is the ratio of the imaginary part of the storage module to the real part of the module and, for the inner layer 12, it is preferably less than 0.05. The polymeric material of the inner layer 12 should have a modulus of flexibility of at least 100 MPa. Suitable polymeric materials for inner layer 12, include, but are not limited to polyimides (nylon), polyimides, polyesters, fluoroplastics (such as polyvinyl fluoride or polyvinylidene fluoride), epoxy, polyphenylene sulfides, polyacetals, phenolic resins , polyketones and polyolefins. The outer layer 14 is comprised of a polymeric material which is molded by extrusion around the layer 12.

The layer 14 is not attached, or weakly bonded to the inner layer 12. It is complementary to the inner layer 12 • in that, while the inner layer 12 provides protection against corrosive and chemical liquids, the outer layer 5 14 provides resistance to chipping and deterioration of impact with stones and abrasion. The outer layer 14 is also responsible for absorbing the impact energy as well as eliminating mechanical vibration and acoustic noise. Heat insulation and protection thermal are also provided by the layer 14. The polymeric material of the outer layer 14 is a multi-phase polymer. The term "multiple phases" indicates that the material is a mixture or a copolymer of two or more polymers. By understanding two or For more polymeric components, the polymeric material of the outer layer can be adjusted with specific wetting characteristics (natural frequency and transmissibility) to isolate or absorb the forced frequencies of mechanical vibrations and acoustic noise. The multi-phase polymer of outer layer 14 has a high wetting factor of at least 0.05. Preferably, the wetting factor is between 0.1 and 0.3 in an application temperature range between -50 and 150 degrees Celsius. This high wetting factor provided for greater dissipation of impact energy makes the wetting factor lower in the inner layer. The modulus of flexibility of the polymer of the outer layer should be less than 50 MPa. A lower flexibility module means that the polymeric material is less rigid (more flexible) than the polymer of the inner layer. The thickness of the wall of the outer layer 14 should be greater than 50 microns. The preferred wall thickness is between 200 and 500 microns. The use of a multi-phase polymer having at least two different polymer components is advantageous in that each component will have a different glass transition temperature. At temperatures close to the glass transition temperature of a polymer, the polymer has a very high wetting factor. By providing a multi-phase polymer with multiple glass transition temperatures, therefore, high wetting factors over a wide temperature range will be provided and, consequently, the best ability will be provided to eliminate mechanical vibrations and acoustic noise under ambient environments. engineering service. Preferably, at least one of the polymer components of the outer layer will have a glass transition temperature below the temperature (22 celcius) and the other external polymer component will have a ^^^ | faith «igí» te ^^ »^^^ í ^^ j ^^^? ^ ttaMj» ^ ... ^ U, .T. J? SU. melting point above 100 degrees Celcius. It is also preferred that a polymer component is an elastic phase and • the other component is a thermoplastic phase. The outer layer 14 also has a high degree of heat resistance. Reflective heat fillers can be added to the polymer material of layer 14 to increase heat resistance. The multi-phase polymeric materials for outer layer 14 include, but are not limited to • 10 to copolymers or mixtures of polymers (or alloys) of polyamides, polyesters, polyolefins, polyurethanes and polyvinyl chloride. The thermoplastic polyolefin (TPO) is a specific example of a suitable polymer blend. Before the application of the layers 12 and 14 on the metal tube 10, the tube 10 can be treated on the sce with a substrate to further increase the corrosion resistance. Suitable materials for the treatment of the sce of the tube 10 include, chromate, phosphate, zinc, aluminum-rich paint, zinc-aluminum-rich substrates, zinc-nickel substrates or a mixture of these materials. This, in addition, will increase the resistance to corrosion. Joints, dynamic mechanical properties unique layers 12 and 14 combine to provide * Aj & amp; Ampf & & P * «. «- ~ - > ^ ~ * .-- o ^ fc - * -Sa-a ------ feu¿ »- ^ •«! > Notable embodiments and to achieve multiple protections for metal pipes used in fluid or automotive transportation applications. The inner layer 12 provides protection against corrosive liquids and dangerous chemicals, while the outer layer 14 provides resistance against deterioration, abrasion, chipping and impact with the stones, absorbs the energy of the impact and isolates or absorbs mechanical vibrations and acoustic noises . • 10 The following are examples of coatings of specific tubes adapted in accordance with the present invention. These examples are provided for illustrative purposes only and are not intended or construed as limiting the scope of this invention. 15 EXAMPLE 1 A steel tube was treated on the sce with a zinc-aluminum substrate. An inner layer comprising PVF (polyvinyl fluoride) was bonded to the treated sce of the steel pipe. An outer layer comprising a mixture of polyamide polymer and EPDM rubber was molded by extrusion onto the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for end assemblies or connections.

EXAMPLE 2 • A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising 5 PVF (polyvinyl fluoride) was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyolefin polymer and EPDM rubber was molded by extrusion onto the inner layer. The outer layer was cut or disassembled to the ends of the tube • 10 provided for end assemblies or connections.

EXAMPLE 3 A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising of extrusion-molded nylon was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyolefin polymer and EPDM rubber was molded by extrusion onto the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections.

^ V-J ^ s * EXAMPLE 4 ^ A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising polyketone extrusion molded was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyamide polymer and EPDM rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled at the ends of the • 10 tube provided for end assemblies or connections.

EXAMPLE 5 A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising extrusion-molded polyketone was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyolefin polymer and EPDM rubber was molded by extrusion onto the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections.

EXAMPLE ^ P A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising 5 of PVF (polyvinyl fluoride) was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of PVC polymer (polyvinyl chloride) and nitrile rubber was molded by extrusion onto the inner layer. The outer layer was cut or disassembled • 10 the ends of the tube provided for the end assemblies or connections.

EXAMPLE 7 A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising PVF (polyvinyl fluoride) was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of PVC polymer (chloride of polyvinyl) and nitrile rubber was molded by extrusion onto the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections.

EXAMPLE 8 A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising 5 PVF (polyvinyl fluoride) was bonded to the treated surface of the steel pipe. An outer layer comprising a copolymer of thermoplastic polyester elastomer was molded by extrusion on the inner layer. The outer layer was cut or disassembled at the ends of the • 10 tube provided for end assemblies or connections.

EXAMPLE 9 A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising of extrusion-molded nylon was bonded to the treated surface of the steel pipe. An outer layer comprising a copolymer of thermoplastic elastomer of The polyester was molded by extrusion onto the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections.

EXAMPLE 10 A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising an epoxy was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyamide polymer and EPDM rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the assemblies # 10 of the end or connections.

EXAMPLE 11 A steel tube was treated on the surface with a zinc-aluminum substrate. An inner layer comprising an epoxy was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyolefin polymer and EPDM rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections. ^ »* ^ ^ ^ ^ ^ ^ ^^^^^^^ &^^^^^^ EXAMPLE 12 ^ A steel tube was glued to the surface with a zinc-nickel substrate. An inner layer comprising 5 of PVF was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyamide polymer and EPDM rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the assemblies • 10 end or connections.

EXAMPLE 13 A steel tube was treated on the surface with a zinc-nickel substrate. An inner layer comprising PVF was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyolefin polymer and EPDM rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections. - ' üí? - ?? i- EXAMPLE 14 A steel tube was treated on the surface with a zinc-nickel substrate. An inner layer comprising 5 of extrusion molded nylon was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyolefin polymer and EPDM rubber was molded by extrusion onto the inner layer. The outer layer was cut or disassembled to the ends of the tube • 10 provided for end assemblies or connections.

EXAMPLE 15 A steel tube was treated on the surface with a zinc-nickel substrate. An inner layer comprising polyketone extrusion molded was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyamide polymer and EPDM rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections.

EXAMPLE 16 A steel tube was treated on the surface with a zinc-nickel substrate. An inner layer comprising polyketone extrusion molded was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyolefin polymer and EPDM rubber was molded by extrusion onto the inner layer. The outer layer was cut or disassembled at the 10 ends of the tube provided for the end assemblies or connections.

EXAMPLE 17 A steel tube was treated on the surface with a zinc-nickel substrate. An inner layer comprising PVF was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of PVC polymer and nitrile rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections.

EXAMPLE 18 P A steel tube was treated on the surface with a zinc-nickel substrate. An inner layer comprising 5 of extrusion molded PVF was bonded to the treated surface of the steel pipe. An outer layer comprising a copolymer of thermoplastic polyester elastomer was molded by extrusion onto the inner layer. The outer layer was cut or disassembled at the ends of the • 10 tube provided for end assemblies or connections.

EXAMPLE 19 A steel tube was treated on the surface with a zinc-nickel substrate. An inner layer comprising of extrusion-molded nylon was bonded to the treated surface of the steel pipe. An outer layer comprising a copolymer of thermoplastic elastomer of The polyester was molded by extrusion onto the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections.

EXAMPLE 20 ^ P A steel tube was treated on the surface with a zinc-nickel substrate. Uses inner layer comprising 5 of an epoxy bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyamide polymer and EPDM rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the assemblies • 10 end or connections.

EXAMPLE 21 A steel tube was treated on the surface with a zinc-nickel substrate. An inner layer comprising an epoxy was bonded to the treated surface of the steel pipe. An outer layer comprising a mixture of polyolefin polymer and EPDM rubber was molded by extrusion on the inner layer. The outer layer was cut or disassembled to the ends of the tube provided for the end assemblies or connections.

Several factors of the present invention have been described with reference to the modalities shown and described. It should be understood, however, that modifications can be made without departing from the spirit and scope of the invention represented by the following claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear to • 10 from the present description of the invention. Having described the invention as above, the content of the following is claimed as property. fifteen • twenty Zt & Íti &.? A * ¿a? .i ^^^ - -! ^^^

Claims (27)

1. CLAIMS i. An adapted coated metal pipe, • characterized in that it comprises: 5 a metal tube; an inner layer of a first polymeric material bonded to said tube to provide protection against corrosion, the first polymeric material having a high crystallinity, a low wetting factor, and a • 10 high flexibility module; and an outer layer of a second polymeric material surrounding the inner layer to absorb the impact energy and eliminate mechanical vibrations and acoustic noises, said second polymeric material having a high wetting factor and a low modulus of flexibility, and said second polymeric material is a multi-phase polymer having at least two polymer components, each of said components having a different glass transition temperature. twenty
2. 2. An adapted coated metal pipe as claimed in claim 1, characterized in that said inner layer and said outer layer are not joined or are weakly joined.
3. 3. An adapted coated metal pipe as claimed in claim 1, characterized in that said polymeric material has a wetting factor of less than 0.05 and a modulus of flexibility of at least 100. 5 MPa.
4. 4. An adapted coated metal pipe as claimed in claim 1, characterized in that said second polymeric material has a factor of • 10 wetting of less than 0.05 and a modulus of flexibility less than 50 Mpa.
5. 5. A coated metal pipe adapted as claimed in claim 4, characterized in that said wetting factor of the second polymeric material has a value between 0.1 and 0.3 in a range of application temperature between -50 and 150 degrees Celcius.
6. 6. An adapted coated metal pipe as claimed in claim 1, characterized in that said outer layer has a wall thickness of at least 50 microns.
7. 7. An adapted coated metal pipe as claimed in claim 6, characterized in that • said wall thickness is between 200 and 500 microns.
8. 8. An adapted coated metal pipe as claimed in claim 1, characterized in that one of the components of said second polymeric material is an elastic phase and another of the components is a phase. • 10 thermoplastic.
9. 9. An adapted coated metal pipe as claimed in claim 1, characterized in that 15 the reflective heat fillers are placed in the second polymeric material to provide a high degree of heat resistance.
10. 10. An adapted coated metal pipe as claimed in claim 1, characterized in that the first polymeric material is selected from the group consisting of polyamides, polyimides, polyesters, fluoroplastics, epoxy, polyphenylene sulphides, 25 polyacetals, phenolic resins, polyketones and polyolefins,
11. 11. An adapted coated metal pipe as claimed in claim 1, characterized in that the second polymeric material is comprised of copolymers or polymer blends of polymers selected from the group consisting of polyamides, polyesters, polyolefins, polyurethanes and • 10 polyvinyl chloride.
12. 12. An adapted coated metal pipe as claimed in claim 1, characterized in that the metal pipe is treated on the surface with a substrate selected from the group of chromate, phosphate, zinc, paint rich in aluminum, zinc-aluminum, zinc-nickel or a mixture thereof.
13. 13. An adapted coated metal pipe characterized in that it comprises: a metal pipe; an inner layer of a first material 25 polymeric attached to said tube to provide protection ? It is against corrosion, said first polymeric material having a high crystallinity, a low wetting factor of 0 less than 0.05, and a high flexibility modulus of at least 100 MPa; and an outer layer of a second polymeric material not bound or weakly bound to said inner layer, the second polymeric material is a multi-phase polymer having at least two polymer components, each of the components having a • 10 transition temperature to different glass, at least one of the components has a glass transition temperature below room temperature.
14. 14. An adapted coated metal pipe as claimed in claim 13, characterized in that the second polymeric material is an amorphous copolymer of at least two polymer blocks, one of the blocks is a soft segment block having a temperature of 20 transition to glass below room temperature, and another of the blocks is a hard segment block that has a melting point above 100 degrees Celsius.
15. 15. An adapted coated metal pipe as claimed in claim 13, characterized in that - ^ P one of the components of the second polymeric material is an elastic phase and the other of the components is a phase 5 thermoplastic.
16. 16. A coated metal pipe characterized in that it comprises: a metal pipe; an inner layer of a first polymeric material bonded to said tube to provide protection against corrosion, said first polymeric material having a high crystallinity, a low wetting factor of 15 less than 0.05, and a high flexibility module of at least 100 MPa; and an outer layer of a second polymeric material not bonded or weakly bonded to said inner layer, to absorb the energy of the impact and to To eliminate mechanical vibrations and acoustic noises, the second polymeric material has a high wetting factor of at least 0.05 and a lower flexibility modulus of at least 50 MPa. 25
17. 17. An adapted coated metal pipe as claimed in claim 16, characterized in that ^ P said wetting factor of the second polymeric material is between 0.1 and 0.3 in a temperature range of 5 application between -50 and 150 degrees Celsius.
18. 18. An adapted coated metal pipe as claimed in claim 16, characterized in that • 10 the outer layer has a wall thickness of more than 50 microns.
19. 19. A coated metal pipe adapted as claimed in claim 18, characterized in that said wall thickness is between 200 microns and 500 microns.
20. 20. An adapted coated metal pipe as claimed in claim 16, characterized in that the reflective fillers are placed in the second polymeric material to provide a high degree of heat resistance.
21. 21. An adapted coated metal pipe characterized in that it comprises: • p a stainless steel pipe; and a coating layer of a material 5 polymeric which is not bound or weakly attached to said tube, said polymeric material has a wetting factor of at least 0.05 and a modulus of flexibility of at least 30 MPa.
22. • 22. An adapted coated metal pipe as claimed in claim 21, characterized in that said polymeric material is a copolymer or polymer blend of polymers selected from the group that 15 consists of polyamides, polyesters, polyolefins, polyurethanes and polyvinyl chloride.
23. 23. A coated metal pipe adapted as 20 is claimed in claim 21, characterized in that said wetting factor is between 0.1 and 0.3 in a range of application temperature between -50 and 150 degrees Celcius 25 ? ^^^ X4 j¡? M ^^
24. 24. An adapted coated metal pipe characterized in that it comprises: a steel pipe; an inner layer of a first material; and an outer layer of a second polymeric material which is not bound or weakly bonded to said interior, the second polymeric material has a high wetting factor of at least 0.05 and a modulus of flexibility of less than 30 MPa. • 10
25. 25. An adapted coated metal pipe as claimed in claim 24, characterized in that the first material is selected from the group consisting of nylon, polyvinyl chloride, polyvinylidene fluoride, epoxy or a coating rich in aluminum.
26. 26. A coated metal tubing adapted as claimed in claim 24, characterized in that the second polymeric material is comprised of copolymers or polymer blends of polymers selected from the group consisting of polyamides, polyesters, polyolefins, polyurethane and sodium chloride. polyvinyl. yada-á - ¡- t - »--- * ---- a &^ -. ¿^? '^ - ^ - ^? - l-- ib-
27. 27. An adapted coated metal pipe characterized because it comprises: • a metal tube; an inner layer of a first polymeric material bonded to the metal tube for protection against corrosion, said first polymeric material having a high crystallinity, a wetting factor of at least 0.05 and a modulus of flexibility of at least 100 MPa; and an outer layer of thermoplastic polyolefin the • which is not attached or is weakly bound to said inner layer. fifteen twenty 25