MXPA06001911A - Impact-modified polyamide hollow body - Google Patents

Abstract

Hollow bodies made from impact-modified polyamide. Fuel line hoses for both liquid fuel delivery and fuel vapor recovery.

Description

HOLLOW BODY POLYAMIDE MODIFIED IMPACT FIELD OF THE INVENTION The invention concerns hollow bodies made of modified impact polyamide. The hollow bodies according to the invention comprise, as a single layer, (1) at least one layer Ll comprising an aromatic polyamide and an impact modifier, and, optionally, (2) at least one layer L2 comprising an aliphatic polyamide . Preferred hollow bodies disclosed include the conduit, for example the conduit useful in the automotive industry for, for example, moving fluids such as gasoline, engine vapor, etc. Additional advantages and other aspects of the present invention will be set forth partially in the description that follows and will be partially obvious to those who have experience in the art of examining what follows or can be learned from the practice of the present invention. The advantages of the present invention can be realized and obtained as indicated in the appended claims. As will be realized the present invention is capable of other and different modalities, and its various details are capable of remodifications in several obvious aspects, all without departing from the present invention. The invention is to be considered as illustrative in nature, and not restrictive. BACKGROUND OF THE INVENTION Polymeric hollow body articles have many uses including the handling of liquids and storage containers, hoses, conduits, and pipes. The use of polymeric hollow bodies, such as conduits and hoses, is increasing. One such application is hoses and lines of fuel lines of motor vehicles. Currently this application includes the use of both monolayer and multilayer aliphatic polyamide (PA), high heat elastomer composites, and textured polytetrafluoroethylene (PTFE). At the same time there is also a trend towards higher temperatures in both passenger and diesel under-the-hood applications. While textured PTFR and high heat elastomer components can be used in these higher heat environments, the constructions are often complex and expensive. The use of aliphatic polyamide also has limitations in these high heat applications. In particular, PA12 has limitations with respect to both fuel permeation and long-term heat at higher temperatures present in newer vehicles. Multilayer constructions are often subject to delamination, especially where fluoropolymer layers are present, and generally require special chemical bond between layers as in U.S. 6,524,671. There are different requirements for the steam return line and the liquid fuel line in the current fuel systems. In the steam line, one of the primary requirements is the protective property to prevent vapors from escaping into the environment, as well as long-term mechanical and thermal requirements. The mechanical requirements include sufficient flexibility and impact resistance for both manufacturing and safety. In addition to requirements for steam lines, the liquid lines include the requirement that essentially, none of the components in the fuel line contaminate the fuel, which could lead to problems, such as clogging of the fuel injectors.

SUMMARY OF THE INVENTION The present invention addresses the problems of the prior art and provides a hollow body comprising, as a single layer, (l) at least one layer Ll comprising an aromatic polyamide and an impact modifier, and optionally, ( 2) at least one layer L2 comprising an aromatic polyamide. In a preferred embodiment Ll is the single layer of the hollow body. In another preferred embodiment, the layers Ll and L2 are in direct contact with each other and are the single layers comprised in the hollow body. In a further preferred embodiment the hollow body comprises three and only three contiguous layers, in the order L1 / L2 / L1. In yet a further preferred embodiment the hollow body comprises two or more contiguous Ll layers. In a further preferred embodiment the hollow body is constituted by any number of contiguous layers of the order [(Ll) n / (L2) m] x, where x is any integer of 1 or greater, n is any integer of 1 or greater and m is any integer (for example 0, 1, 2, etc.). In another preferred embodiment, the hollow body does not contain a fluoropolymer layer, where the hollow body of the invention is a multilayer construction, each of the layers Ll and L2 may be the same or different from each other. The hollow bodies of the invention can be made in any desired way from the identified materials to produce the layers Ll and L2, such as by extrusion, such techniques are well known to those skilled in the art. Preferably, the hollow body of the invention is in the form of a tube or hose, these terms are used interchangeably herein. The size, shape, thickness of the wall, texture of the surface, etc. of the hollow bodies of the invention are not limited in any way.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is an illustration of an adaptation by extrusion useful for extruding monolayer hoses in accordance with the invention. Figure 2 is an illustration of an extrusion fitting used to extrude multilayer hoses in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION As used herein, the term "hollow body" means any structure having an empty or concave part. In particular, the hollow body can have the shape of a tube, hose or conduit, a container, etc. The term "inner layer" means the intimate layer of the hollow body on the same side as the concave or empty part of this body. Typically, the inner layer is brought into contact with the "content" provided to fill, flow through, etc. the hollow body of the invention. The term "outer layer" means the outermost layer of the hollow body on the side away from the concave or empty part; that is, there are no other layers of the hollow body immediately adjacent to and external to the outer layer. Of course, these terms "inner layer" and "outer layer" only apply to multilayer embodiments of the invention. Where the hollow body is constituted by an individual layer, it is called "monolayer". Hollow bodies within the scope of this invention include containers for handling and storing liquids, conduits, pipes, and hoses. In particular, certain embodiments of the present invention are hoses for steam and fuel lines for motor vehicles, air, aquatic, recreational vehicles, and agricultural and industrial equipment including both liquid fuel release lines and vapor recovery lines. Polyamides Polyamides are, generally speaking, polymers that contain a repeating amide (CONH) functionally. Typically, the polyamides are formed by reacting the diacid and diamine monomer units (eg, nylon 6,6), or by polymerization of an amino carboxylic acid or caprolactam (eg, nylon 6). Polyamides are well-known materials. Polyamides that are useful herein include those described in U.S. Pat. 6,531,529, 6,359,055, 5,665,815, 5,436,294, 5,447,980, RE34,447, 6,524,671 (DuPont), 6,306,951 (BP Corp.) and 5,416,189 as well as those marketed by Solvay Advanced Polymers under the trade names Amodel® and IXEF®. The invention concerns both aromatic and aliphatic polyamides. The aromaticity of the aromatic recurring units may be due to the diacid and / or the diamine for the polyamides resulting from the polycondensation. Preferably, the polyamides used herein, especially the aromatic polyamides, are prepared by polycondensation. Ll Composition of Polyamide L-polyamide compositions for hollow bodies useful herein comprise an aromatic polyamide and an impact modifier. Aromatic Polyamide Aromatic polyamides are polymers comprising more than 50 mole% of "Type 1" repeating units, based on 100 mole percent repeating units in the polymer. Type 1 repetition units have at least one CONH group in the polymer chain. In addition, Type 1 repeat units are characterized in that at least 30 mole% thereof comprises an aromatic group. Accordingly, the minimum content of repeating units containing aromatic group in an aromatic polyamide herein is more than 15 mol% based on 100 mol% repeat units in the polymer. Preferably the aromatic polyamide of the invention comprises at least 20 mol% based on 100 mol% of monomers forming the polyamide, of monomers comprising an aromatic group. Although not required, said aromatic groups typically originate in the polycondensation reaction between diacid monomers and diamine. The aromatic groups can be derived from diacid and / or diamine monomers. Diacid monomers include terephthalic acid, isophthalic acid, phthalic acid (1,2-benzenecarboxylic acid), etc. In preferred embodiments, the aromatic polyamide comprises at least 30 mol%, based on 100 mol% of monomers forming the polyamide, of monomers comprising an aromatic group, including 35, 40, 45, 50, 55, 60, 65, 70 , 75, 80, 85, etc% molar. One class of preferred aromatic polyamides are PMXDAs, ie aromatic polyamides comprising more than 50 mol% of recurring units formed by the polycondensation reaction between at least one aliphatic diacid and metaxylylenediamine. The aliphatic diacid may be particularly adipic acid.

Suitable PMXDAs are particularly available as IXEF® PMXDAs from Solvay Advanced Polymers. Another class of preferred aromatic polyamides are polyphthalamides (PPA), ie aromatic polyamides comprising more than 50 mol% of recurring units formed by the polycondensation reaction between at least one of terephthalic acid, isophthalic acid, and phthalic acid and at least an aliphatic diamine. The aliphatic diamine can be, in particular, hexamethylenediamine, nonanodiamine, 2-methyl-1, 5-pentadiamine, and 1,4-diao-n-butane. Suitable polyphthalamides are particularly available as AMODEL® polyphthalamides from Solvay Advanced Polymers, LLC. Among the polyphthalamides, polyterephthalamides are preferred. Polyterephthalamides are defined as aromatic polyamides comprising more than 50 mol% of recurring units formed by the polycondensation reaction between terephthalic acid and at least one diamine. A group of preferred polyterephthalamides are polyterephthalamides consisting essentially of recurring units formed by the polycondensation reaction between terephthalic acid and at least one aliphatic diamine. In the polyterephthalamides of this group, the aliphatic diamine preferably comprises from 3 to 9 carbon atoms, and most preferably, comprises 6 carbon atoms. An example of aliphatic diamine comprising 6 carbon atoms is hexamethylenediamine. A second group of preferred polyterephthalamides are polyterephthalamides consisting essentially of recurring units formed by the polycondensation reaction between terephthalic acid, isophthalic acid and at least one aliphatic diamine. In this embodiment, the molar ratio of terephthalic acid and isophthalic acid can be from 50 to 80 (including 55, 60, 65, 70, and 75) for terephthalic acid and from 10 to 40 (including 15, 20, 25, and 35) for isophthalic acid. In another embodiment, the molar ratio can be from 35 to 65 for terephthalic acid and no more than 20 for isophthalic acid. A third group of preferred polyterephthalamides are polyterephthalamides consisting essentially of recurring units formed by the polycondensation reaction between terephthalic acid, at least one aliphatic diacid and at least one aliphatic diamine. In this embodiment, the molar ratio of terephthalic acid and aliphatic diacid can be from 50 to 80 (including 55, 60, 65, 70, and 75) for terephthalic acid and not more than 25 (including 5, 10, 15, and 20) for the aliphatic diacid. In another embodiment, the molar ratio can be from 35 to 65 for terephthalic acid and from 30 to 60 for the aliphatic diacid. A fourth group of preferred polyphthalamides are polyterephthalamides consisting essentially of recurring units formed by the polycondensation reaction between terephthalic acid, isophthalic acid, at least one aliphatic diacid and at least one aliphatic diamine. In this embodiment, the molar ratio of terephthalic acid and terephthalic diacid can be from 50 to 80 (including 55, 60, 65, 70 and 75) for terephthalic acid; from 10 to 40 (including 15, 20, 25, and 35) for isophthalic acid; and no more than 25 (including 5, 10, 15, and 20) for the aliphatic diacid. In another embodiment, the molar ratio can be from 35 to 65 for terephthalic acid; not more than 20 for isophthalic acid; and from 30 to 60 for the aliphatic diacid. Another preferred aromatic polyamide useful herein is one made from terephthalic acid, adipic acid, optionally isophthalic acid, and hexamethylene diamine. In another preferred embodiment the aromatic polyamide is a polyamide with at least 50 mol%, including up to 100 mol% of recurring units obtained by means of the polycondensation reaction between terephthalic, isophthalic, adipic acid; and at least one diamine, preferably an aliphatic. In this group, the molar ratio of terephthalic / isophthalic / adipic acid can be from 50 to 80 / from 10 to 40 / not more than 25. In another embodiment the molar ratio of terephthalic / isophthalic / adipic acid can be from 35 to 65 / not more than 20 / from 30 to 60. In preferred embodiments the diamine component for these acid mixtures is HMDA. In certain embodiments of the present invention, the dicarboxylic acid component used in the formation of the polyphthalamide comprises a molar ratio of aromatic dicarboxylic groups in the range from at least about 50 mol% of aromatic groups to about 100% aromatic groups. In a preferred embodiment of the present invention, the polyphthalamide polymer comprises from about 50 mol% to about 95 mol% of hexamethylene terephthalamide units, from about 25 mol% to about 0 mol% of hexamethylene isophthalamide units, and from about 50 mol% to about 5 mol% hexamethylene adipamide units. Another useful aromatic polyamide is one made from terephthalic acid, isophthalic acid and an aliphatic amine such as HMDA, for example, using a ratio of 70/30 TA / IA. Particularly suitable polyphthalamides for use in the present invention are available as AMODEL® A-1000, A-4000, A-5000, and A-6000 polyphthalamides from Solvay Advanced Polymers, LLC. Suitable polyphthalamides for use in the present invention are described in the aforementioned U.S. Patents. Nos. 5,436,294; 5,447,980; and RE34,447 of Poppe et al. Of course, more than one aromatic polyamide can be used in the polyamide Ll composition. Impact Modifier Impact modifiers useful herein are not particularly limited, as long as they impart useful properties to the aromatic polyamide component of the Ll layer of the invention, such as sufficient tensile elongation to deformation and rupture. For example, low modulus of elasticity functionalized polyolefin impact modifier with a vitreous transition temperature of less than 0 ° C is suitable for this invention, including the functionalized impact modifiers described in U.S. 5,436,294 and 5,447,980. Useful impact modifiers include polyolefins, preferably functionalized polyolefins, and especially elastomers such as SEBS and EPDM.

Useful functionalized polyolefin impact modifiers are available from commercial sources, including maleated polypropylenes and ethylene-propylene copolymers available as EXXELOR ™ PO and ethylene-propylene copolymer elastomer functionalized with maleic anhydride comprising about 0.6 weight percent of suspended succinic anhydride groups, such as EXXELOR® RTM. VA 1801 of the Exxon Mobil Chemical Company; acrylate-modified polyethylenes available as SURLYN®, such as SURLYN® 9920, methacrylic acid modified polyethylene from the DuPont Company; and PRIMACOR®, such as PRIMACOR® 1410 XT, polyethylene modified with acrylic acid, from the Dow Chemical Company; styrene-ethylene-butylene-styrene block copolymer (SEBS) modified with maleic anhydride, such as KRATON® FG 1901X, an SEBS that has been grafted with about 2% by weight of maleic anhydride, available from Kraton Polymers; terpolymer elastomer of ethylene-propylene-diene monomers (EPDM) functionalized with maleic anhydride, such as ROYALTUF® 498, an EPDM functionalized with 1% maleic anhydride, available from Crompton Corporation. The hollow bodies of the present invention are not limited to only those formed with these impact modifiers. Suitable functional groups in the impact modifiers include any chemical portion that can react with end groups of the polyamide to provide improved adhesion to the matrix for high temperatures. Other functionalized impact modifiers that can also be used in the practice of the present invention include higher ethylene-alpha-olefin polymers and higher ethylene-alpha olefin-diene polymers that have been provided with reactive functionality by grafting or copolymerized with carboxylic acids suitable reagents or their derivatives such as, for example, acrylic acid, methacrylic acid, maleic anhydride or their esters, and will have a tensile modulus up to about 3515 kg / cm2 (50,000 psi) determined in accordance with ASTM D-638. Suitable higher alpha-olefins include C3 to C8 alpha olefins such as, for example, propylene, butene-1, hexene-1 and styrene. Alternatively, copolymers having structures comprising said units can also be obtained by hydrogenation of suitable homopolymers and copolymers of polymerized 1-3-diene monomers. For example, polybutadienes having varying levels of suspended vinyl units are readily obtained, and these can be hydrogenated to provide ethylene-butene copolymer structures. Similarly, the hydrogenation of polyisoprenes can be • employed to provide equivalent ethylene-isobutylene copolymers. The functionalized polyolefins that can be used in the present invention include those having a melt index in the range of about 0.5 to about 200 g / 10 min. Suitable dienes for use in the preparation of ethylene-alpha-olefin-diene terpolymers are non-conjugated dienes having 4 to about 24 carbon atoms, examples of which include 1,4-hexadiene, dicyclopentadiene and alkylidene norbornenes such as -ethylidene 2- norbornene. Molar fractions of ethylene units and higher alpha-olefin units in the ethylene-alpha-olefin-olefin copolymer elastomers generally range from about 40:60 to about 95: 5. Ethylene-propylene copolymers having about 50 to about 85 mole percent of ethylene units and about 5 to about 50 mole percent of propylene units are included among these. In terpolymers comprising polymerized diene monomers, the content of diene units may vary up to about 10 mol%, and about 1 to about 5 mol% in certain embodiments. Corresponding block copolymers comprising two or more polymeric blocks are also suitable, each formed of one or more monomers selected from ethylene and the higher alpha-olefin. The functionalized polyolefins will generally further comprise about 0.1 to 10% by weight of functional groups. Other impact modifiers useful herein include those described in U.S. 6,765,062 (Ciba Specialty Chemicals Corporation) and EP 901 507 Bl (DuPont). Still other impact modifiers useful herein include acrylic impact modifiers marketed as Paraloid® impact modifiers by Rohm &; Haas. The amount of impact modifier present in the composition Ll is not limited to and preferably will be an amount sufficient to impart sufficient tensile elongation to the deformation and rupture. Generally, the polyamide composition Ll will comprise from about 2% by weight to about 40% by weight of impact modifier, based on the total weight of the composition Ll, including for example 5, 10, 15, 20, 25, 30 and 35% by weight. However, the impact modifier may be present in such small amounts as, for example, 0.1% by weight.

The impact modifier and the aromatic polyamide can be mixed together in any manner, and the mixing can take place before, for example, extrusion, or the material can be mixed in the extruder. Of course, more than one impact modifier can be used in the polyamide composition Ll. Composition of Polyamide L2 The composition of polyamide L2 useful in the present optical layers of the hollow body of the invention and comprises an aliphatic polyamide. The aliphatic polyamides are polymers comprising more than 50 mol% of "Type 2" repeating units, based on 100 mol% of repeating units in the polymer. Type 2 repeat units have at least one CONH group in the polymer chain. Type 2 repeat units are characterized in that less than 30 mol% thereof comprise an aromatic group. Accordingly, the maximum content of repeating units containing aromatic group in an aromatic polyamide herein is less than 15 mol%, based on 100 mol% of repeating units in the polymer. Preferably, the aromatic polyamide comprises more than 85 mol%, for example 90%, etc., based on 100 mol% of monomers comprising the polyamide, of monomers comprising an aliphatic group and having no aromatic group. Said aliphatic groups originate, in a polycondensation reaction, from diacid and diamine monomers. Preferred aliphatic diamines include those comprising 4 to 12 carbon atoms, such as hexamethylene diamine (HMDA), nonane diamine, 2-methyl-1,5-pentadiamine, and 1,4-diaminobutane, etc. A useful diacid source of aliphatic units is adipic acid. Useful examples of aliphatic polyamide L2 compositions include aliphatic polyamides such as PA6, PA6, 6, PA4.6, PAll, and PA6.12. Of course, more than one aliphatic polyamide can be used in the polyamide L2 composition. In addition, the impact modifiers described above can be used in the polyamide composition L2, if desired. Additives The polyamide compositions Ll and L2 can each, individually, optionally, further contain one or more additives. Useful additives include, for example, an external lubricant, such as PTFE or low density polyethylene (LDPE) to facilitate extrusion. Suitable powdered PTFE include POLYM1ST® F5A available from Solvay Solexis.

Another useful additive is a thermal stabilizer. Suitable thermal stabilizers include copper-containing stabilizers comprising a copper compound soluble in the polyamide and an alkali metal halide. More particularly, in certain embodiments the stabilizer comprises a copper (I) salt, for example cuprous acetate, cuprous stearate, a cuprous organic complex compound such as copper acetylacetonate, a cuprous halide or the like, and an alkali metal halide. . In certain embodiments of the present invention, the stabilizer comprises a copper halide selected from copper iodide and copper bromide and an alkali metal halide selected from the iodides and bromides of lithium, sodium, and potassium. The formulations comprising copper (I) halide, an alkali metal halide and a phosphorus compound can also be used to improve the stability of hollow bodies formed from polyphthalamide compositions during prolonged exposure at temperatures up to about 140 ° C. The amount of the stabilizer used is preferably the amount sufficient to provide a level from about 50 ppm to about 1000 ppm copper. Preferred compositions of the invention comprise an alkali metal halide and a copper (I) halide in a weight ratio in the range of from about 2.5 to about 10, more preferably from about 8 to about 10. Generally, the combined weight of compound of copper halide and alkali metal in a stabilized polyamide composition ranges from about 0.01% by weight to about 2.5% by weight. In certain different stabilized polyamide compositions used to form hollow bodies according to the present invention, the stabilizer is present in the range from about 0.1% by weight to about 1.5% by weight. A particularly suitable stabilizer for polyamide compositions according to the present invention comprises tablets of a 10: 1 weight mixture of potassium iodide and cuprous iodide with a binder of magnesium stearate. The potassium iodide / cuprous iodide thermal stabilizer provides protection against long-term thermal aging, such as exposure to car temperatures under the hood. Another useful additive is a filler such as reinforcing filler, or structural fibers. Structural fibers useful in the formation of filled articles and composite products include fiberglass, carbon or graphite fibers and fibers formed from silicon carbide, alumina, titania, boron and the like, as well as resin fibers designed for high temperatures such as such as, for example, poly (benzothiazole), poly (benzimidazole), polyarylates, poly (benzoxazole), aromatic polyamides, polyaryl ethers and the like, and may include mixtures comprising two or more of said fibers. Suitable fibers useful herein include glass fibers, carbon fibers and aromatic polyamide fibers such as fibers marketed by the DuPont Company under the trademark KEVLAR®. Another useful additive is an antioxidant. Useful antioxidants include Nauguard 445, phenols (for example Irganox 1010, Irganox 1098 from Ciba), phosphites, phosphonites (for example, Irgafos 168 from Ciba, P-EPQ from Clariant or Ciba), thiosynergists (for example Lowinox DSTDP from Great Lakes), interrupted amine stabilizers (eg Chimasorb 944 from Ciba), hydroxyl amines, benzofuranone derivatives, phenols modified with acryloyl, etc. Other fillers that can also be used in polyamide compositions according to the invention include antistatic additives such as carbon powders, multi-walled nanotubes and single-walled nanotubes as well as flakes, filler in the form of fibrous and spherical particles, fillers, reinforcement and nucleation such as talc, mica, titanium dioxide, potassium titanate, silica, kaolin, limestone, alumina, mineral fillers, and the like. Fills and structural fibers can be used alone or in any combination. Additional useful additives include, without limitation, pigments, colorants, flame retardants, and the like including those additives commonly used in the arts of resins. The additives can be used alone or in any combination, as necessary. For particular application it may also be useful to include plasticizers, lubricants, and mold releasing agents, as well as thermal, oxidizing and light stabilizers, and the like. The levels of said additives can be determined for the particular use contemplated by an expert in the art in view of this description. Methods The hollow bodies of the invention can be made by any technique known in the art or further developed, including in particular, extrusion. In this regard, one skilled in the art is able to form the hollow bodies of the invention as described herein using the polyamide compositions Ll and L2 in view of this description. The physical dimensions of the hollow body of the invention are not limited. When the hollow body of the invention is a tube or hose, preferred internal diameter ranges of, for example, 2 mm to 20 mm, more preferably, 3 mm to 18 mm. Preferred external diameters vary from 3 mm to 26 mm, more preferably 5 mm to 22 mm. The preferred total wall thicknesses range from 0.5 mm to 2.5 mm, more preferably 1 mm to 2 mm. Where the hollow body comprises two and only two layers, L1 / L2, the preferred thickness ratio L1 / L2 varies from 9 to 0.1, more preferably 4 to 0.25. Although Ll and L2 may each be internal and external layers in the invention, in configurations of the composition Ll in two layers it is preferable that the outer layer when the requirement is thermal resistance or chemical resistance. In such two-layer configurations, Ll is preferably the inner layer when the requirement is the protection resistance (low permeation). The configurations in three layers the composition Ll is both the inner layer and the outer layer, although the compositions of the inner and outer shells in such a configuration need not be identical.

EXAMPLES Illustrative examples of the present invention are provided below, but are not limiting thereof. Table 1 describes four compositions. In addition, a control composition of AMODEL® A-1006 PPA unmodified was prepared. Table 1 The films of Examples 1, 2 and Cl were produced by extrusion. Specimens of ISO IBA tensile were drilled from the films. They were elongated at a head speed of 0.5 mm / min and tested under ISO 527 conditions. As shown in Table 1 below, the impact modifications produced polymeric compositions that had tensile elongation to average strain and rupture more high over the Cl control. In fact, the PPA compositions of the invention comprising the impact modifier have tensile elongation to strain and rupture twice as high as the control. The tensile elongation at the highest deformation and rupture provides greater latitude in the process parameters of the hollow bodies of the present invention.

Table 2 FUEL PERMEATION TESTS Fuel permeation tests were conducted on the example compositions, control, and comparative compositions. The results of the fuel permeation are shown in Table 3 below. The fuel permeation tests were performed on films of the same specimens as those listed in Table 2.

In addition to Examples 1 and 2 of modified impact PPA compositions, permeation measurements were also carried out on liquid crystal polymers (LCP) Vectra® A950, PA12, and the following unmodified PPA compositions: AMODEL® A- 1006-C, A-4000, and A-6000. These film specimens were prepared between two layers of removable high density polyethylene (HDPE). Table 3 The fuel tested is CTF1, a 45/45/10 volume mixture of isooctane / toluene / ethanol. See standard SAE J1681 rev. Jan. 2000. The permeability of the measured fuel was expressed as the number of grams of permeant that would pass through a 1 mm thick sheet and a surface area of 1 m2 in a period of one day. The results obtained with a grade of LCP (liquid crystal polymer) Vectra® A 950 exhibited superior protective properties, are given as a reference and illustrate the detection limits of the method. The permeability of the modified PPA, Examples 1 and 2, is superior to that of the aliphatic PA. PA12 is very permeable and a steady state was never achieved. Ethanol and toluene began to infiltrate very quickly after the test spread and the cells of these species quickly began to deplete. The tentative permeability values were calculated from the mass transfer measurements carried out at the beginning of the test via chromatography. It is believed that the tabulated values are lower than the current permeability values. Table 4 below summarizes the permeability results measured at 60 ° C on various fluoropolymers. As can be seen from Tables 3 and 4, all the PPA compositions of the invention (strengthened at 165 ° C or dried as molded) had comparable fuel permeations to fluoropolymers and higher to polyamides. Despite the fact that it is believed that the incorporation of elastomers in the polyamide compositions of the invention is detrimental to the protective properties of PPA, especially with respect to alcohol and aromatic components in the fuel, the protective properties were retained very well . As for the permeability of toluene and isooctane, the elastomer-modified polyphthalamide compositions are at least as good as the fluoropolymers listed in Table 4 and are superior to those of PA. For the ethanol component of the CTF1 fuel at 60 ° C, the modified polyphthalamides are only slightly less effective than the poly (vinylidene fluoride) (PVDF) homopolymer and the ethylene-tetrafluoroethylene (ETFE) copolymer, at least as good as the other fluoropolymers listed in Table 4, and greater than PA.

Table 4 Extraction Data Although the exudation of the component components of the polymer fuel line is less critical in steam lines, the presence of such impurities in the liquid fuel line can lead to clogging of the injectors. The solution used for the extraction study consisted of a mixture of 15% methanol and 85% of a 50/50 mixture of toluene / isooctane by volume (CM 15 fuel). The procedure for the extraction comprised the placing of 15 grams of tablet in 80 ml of liquid stirred at 40 ° C for 168 hours, and the dry residue of the decanted solution was measured. The percents of extractables were measured for Examples 1 and 2 and were 0.17 and 0.20 respectively. Although they were not zero, the values of extractable materials are surprisingly low compared to the 8 to 12% of extractables that would be expected for plastified PA12 normally used as a monolayer hose. Comparison of Thermal Aging with PA12 Resistance to long-term thermal aging was considered extremely important for the feasibility of using polymers in fuel lines with ever-increasing temperature requirements in automobiles. A comparison of the stabilized versions of Examples 3 and 4 with thermally stabilized PA12 is provided in Table 5.

Table 5 As can be seen, PA12 suffers a catastrophic loss in Izod impact resistance after thermal aging. As a result, partially modified impact aromatic polyamides are a much safer selection. For the retention of impact properties after long-term exposure to elevated temperatures in the presence of air. Manufacture of Hoses from Modified Impact Polyphthalamide Monolayer Conduit The adaptation for extrusion of monolayer conduits is shown in Figure 1. The materials were dried before the fusion process. The extrusion of the conduit was carried out with a single screw extruder of 30 mm. The screw used was of a standard polyamide or polyethylene screw. Calibration and cooling were done with standard equipment. The cooling tank was under vacuum and in the spray mode. The data for Examples 1-4 are shown below (Table 6). In Table 6, the three zones marked Zl, Z2, and Z3 (rear facing) are where the temperature control can be applied to the extruder. Z4 is the temperature control of the die adapter, and Zcl, Zc2 and Zc3 and the control zones for the die. The die was adapted so that the dimensions of the duct were 8 mm OD and 6 mm ID. Table 6 Examples 1-4 and a PA12 control conduit made from Vestamida® L2140 were subjected to several tests in SAE J2260"NONMETALIC FUEL SYSTEM TUBING WITH ONE OR MORE LAYERS". This was done to establish the suitability of the PPA conduit for the intended applications. The results are summarized in Table 7. Table 7 The hose made from the composition of the Example 2 was pushed over a standard, non-split connector, which is a standard requirement for fuel line connector hose. The hose must be lengthened by approximately 50% in order to be pushed on the connector. This further illustrates the utility as a hose for fuel. The conduits of Examples 1-4 and a PA12 control were tested for tensile property in accordance with ISO 527-2. The results are shown in Table 8. Examples 1-4 showed higher resistance (22 to 35% than PA12).

Multilayer Duct The diagram in Figure 2 illustrates how the three extruders were configured for a three layer punch to produce multilayer pipes. The extruders are marked El, E2, and E3. He withheld the material Ll; E2 retained the material L2; and E3 retained the L2 or Ll material depending on whether two- or three-layer conduits were produced. All extruders were 20 mm in diameter and used polyamide or standard polyethylene screws. For the two-layer constructions, material L2 (PA 6, PA12, etc.) was introduced into both extruders E2 and E3. The PPA formulation of Example 2 was always introduced into the El extruder (inner layer). For the three-layer constructions, the L2 polyamide (PA 6, etc.) was introduced into the E2 extruder. The polyamide Ll (Formulation of PPA of Example 2) was introduced into the extruder El (inner layer) and E3 (outer layer). Calibration and cooling were done with the standard equipment. The cooling tank was under vacuum and in the spray mode. The material corresponding to the inner layer (layer # 1) was fed from the back of the die, while the corresponding input to the external layer (layer # 3) was located on the vertical side downward of the die. Prior to the extrusion runs, all grades of PPA and PA were dried. The data for Examples 5-8 are shown below (Table 9). In Table 9, the three zones marked Zl, Z2, and Z3 (rear facing) are where the temperature control can be applied to the extruder. The temperatures of the adapter, elbow to the inlet of the die, flow distributor and die are also shown in Table 9. Each of the extruders (El, E2, E3) was independently controlled. Table 9 Table 9 (Continued) Example 5. Co-extrusion of two layers of PPA (Ll) / PA 6 (L2) An extrusion run was started with HDPE in the inner layer (1) and Grilon® F50 PA6 in the two outer layers (2,3) . The intermediate temperature of 280 ° C was used to adjust the nozzle set. Both materials were extruded well at this temperature and a thin tube was produced. No adhesion was observed between PA 6 and PE.

After raising the temperatures (see Table 9), the HDPE in the inner layer (1) was replaced with PPA (Formulation Example 2), a multilayer tubular structure was obtained. Adhesion between the inner layer of Ll was demonstrated (Example of Formulation 2 of PPA) and the outer layer L2 (PA 6) of the co-extruded duct by means of duct extensions cut longitudinally in half and flexing and bending the resulting half of the duct.

The layers did not separate. Example 6. Co-extrusion of Two Layers of PPA (Ll) / PA 12 (L2) With the same adjustment as for the coextrusion of PA6 in Example 5, the Grilon® F50 PAß was replaced by Vestamide® L2140, PA 12 without plasticizing (PA 12 U). The cooling in the calibrator had to be adjusted to a lower temperature and an acceptable duct could be produced. Adhesion of the two layers (Formulation Example 2 of PPA and PA 12 U) as tested in the manner described above was excellent. The layers did not separate. Example 7. Co-extrusion of two layers of PPA (L1) / PA 12P (L2) Vestamide® L2140 (PA 12 U) was replaced with Vestamide® LX9013 (PA 12 highly plasticized, (PA 12 P). duct as in Example 5. The adhesion between the two layers (Formulation Example 2 of PPA and PA 12 P) which was tested in the manner described above was excellent.The layers did not separate Example 8.Co-extrusion of three layers of PPA (Ll) / PA 6 (L2) / PPA (Ll) The test was started with HDPE in the inner layer (1) and Grilon® F50 PA6 in the middle layer (2) and HDPE in the outer layer (3) The intermediate temperature of 280 was used ° C to adjust the set of matrices. Both materials extruded well at this temperature and a thin tube was produced. No adhesion was observed between PA 6 and PE. After raising the HDPE temperatures in the inner layer (1) and the outer layer (3)), PPA (Formulation Example 2) is introduced. A three layer construction was obtained. The adhesion between the three layers (Ll = Formulation 2 of PPA; L2 = PA 6; L3 = Formulation Example 2 of PPA) of the co-extruded conduit which was tested in the manner described above showed excellent adhesion. The layers did not separate. As described herein, in certain embodiments of the present invention, the hollow body comprises a monolayer structure of composition Ll. As used herein, a "monolayer" was formed from the single layer of a polymer composition wherein the polymer composition is substantially the same throughout the entire thickness of the layer. In certain embodiments of the present invention, the thickness of the monolayer may vary from about 500 microns to about 12.5 mm. In certain embodiments of the present invention, the thickness of the monolayer varies from about 750 microns to about 7 mm. The hollow bodies of the invention can be used in numerous articles of manufacture, machines, etc. such as powered devices with fossil fuel, etc. The fossil fuel-powered driving devices, as used herein, include motor vehicles such as automobiles, motorcycles, buses, and trucks, air, water, recreational vehicles, and agricultural and industrial equipment. The hollow bodies may have surfaces that are rough, smooth, corrugated, etc. these are of a constant total thickness or a variable thickness, etc. In addition, the hollow bodies of the invention can be used to enclose or encapsulate a content, and the content can vary widely. For example, the hollow body of the invention can be used as a cable protection system. In this regard, the invention is also described as actively containing or retaining its intended content - for example, the invention describes and facilitates a hollow body in the form of a fuel line, said fuel line optionally comprising fuel. The description of the invention written above provides a way and process of making and using it so that any expert in this art will be facilitated to elaborate and use it, this facility being provided in particular for the subject of the appended claims, which constitute a part of the original description and include a hollow body comprising, as single layers: (1) at least one layer Ll comprising an aromatic polyamide and an impact modifier, and, optionally, (2) at least one layer L2 comprising an aliphatic compound. Similarly, the preferred preferred embodiments of the invention include hollow bodies wherein the aromatic polyamide is a polyphthalamide; the aliphatic polyamide is an aliphatic nylon; the impact modifier is selected from the group consisting of EPDM, SEBS, and mixtures thereof; the aromatic polyamide is a polyamide having at least 50 mol% of recurring units obtained by means of a polycondensation reaction between at least one dicarboxylic acid selected from the group consisting of phthalic, terephthalic, and isophthalic acids and mixtures thereof and minus an aliphatic diamine; the polyphthalamide comprises from about 50% b molar to about 95% molar of hexamethylene terephthalamide units, from about 25 mol% to about 0 mol% of hexamethylene isophthalamide units, and from 50 mol% to about 5 mol% of hexamethylene adipamide units; the impact modifier is an elastomer, the elastomer is an elastomer based on functionalized polyolefins; the elastomer based on functionalized polyolefins is a styrene-ethylene-butylene-styrene block copolymer functionalized with maleic anhydride; the elastomer based on functionalized polyolefins is a monomeric ethylene-propylene-diene elastomer functionalized with maleic anhydride; the layers are contiguous layers of the order of [(Ll) n / (L2) m] x where x is any integer of 1 or greater, n is any integer of 1 or greater, and m is any integer; the layer Ll additionally comprises an external lubricant; the external lubricant is selected from the group consisting of polytetrafluoroethylene, low density polyethylene, and mixtures thereof; The layer Ll additionally comprises a thermal stabilizer comprising at least one copper salt (1) and at least one alkali metal halide, the thermal stabilizer comprises at least one copper halide selected from the group consisting of copper iodide and copper bromide. copper and at least one alkali metal halide selected from the group consisting of lithium, sodium, and potassium iodides and bromides; the hollow body consists of, as a single layer, a monolayer comprising an aromatic polyamide and an impact modifier; the hollow body is a hose, the hose comprises all or part of a vapor return line or a liquid fuel line; a device energized with fossil fuel, such as a car, comprising the hose of the invention; and a method for making a hollow body comprising as single layers, (1) at least one layer Ll comprising an aromatic polyamide and an impact modifier, and, optionally, (2) at least one layer L2 comprising an aliphatic polyamide , which comprises extruding an aromatic polyamide and an impact modifier, and optionally extruding an aliphatic polyamide, through a die. As used herein, a certain polymer is mentioned as being "obtained from" or "comprising", etc. one or more monomers (or monomer units) this description is of the finished polymer material by itself and the repeating units therein which constitute, wholly or partially, this finished product. A person skilled in the art will understand that, specifically speaking, a polymer does not include individual, unreacted "monomers," but is preferably made up of repeat units derived from the monomers that reacted. All references, patents, applications, tests, documents, publications, brochures, texts, articles, etc. which are mentioned herein, are incorporated herein by reference. Similarly, all brochures, technical information sheets, etc., for all commercially available materials are incorporated herein by reference. When a numerical limit or interval is declared, endpoints are included. As well, all values and subintervals in a numerical limit or range are specifically included as if they were explicitly transcribed. The above description is presented to facilitate an expert in the matter to elaborate and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Accordingly, the invention is not intended to be limited to the modes shown, but is to be in accordance with the broadest scope consistent with the principles and aspects described herein.

Claims (19)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty, and therefore the content of the following is claimed as property: CLAIMS 1. A hollow body characterized in that it comprises as a single layer, (1) at least one layer Ll comprising an aromatic polyamide and an impact modifier, and, optionally, (2) at least one layer L2 comprising an aliphatic polyamide.
2. 2. The hollow body according to claim 1, characterized in that the aromatic polyamide is a polyphthalamide.
3. 3. The hollow body according to claim 2, characterized in that the hollow body comprises at least one layer L2.
4. 4. The hollow body according to claim 1, characterized in that the impact modifier is selected from the group consisting of EPDM, SEBS, and mixtures thereof. The hollow body according to claim 1, characterized in that at least one layer Ll comprises an aromatic polyamide obtained by means of the polycondensation reaction between hexamethylenediamine and a terephthalic / isophthalic / adipic acid composition where the molar ratio of terephthalic acids / isophthalic / adipic in said composition is from 50 to 80 / from 10 to 40 / not more than 25. The hollow body according to claim 2, characterized in that the polyphthalamide comprises from about 50 mol% to about 95 mol% of hexamethylene terephthalamide units, from about 25 mol% to about 0 mol% hexamethylene isophthalamide units, and from about 50 mol% to about 5 mol% hexamethylene adipamide units. The hollow body according to claim 1, characterized in that the impact modifier is an elastomer. 8. The hollow body according to claim 7, characterized in that the elastomer is an elastomer based on functionalized polyolefin. 9. The hollow body according to claim 8, characterized in that the elastomer based on the functionalized polyolefin is a styrene-ethylene-butylene-styrene block copolymer functionalized with maleic anhydride. The hollow body according to claim 8, characterized in that the elastomer based on the functionalized polyolefin is a monomeric ethylene-propylene-diene elastomer functionalized with maleic anhydride. The hollow body according to claim 6, characterized in that the impact modifier is selected from the group consisting of a monomeric ethylene-propylene-diene elastomer functionalized with maleic anhydride, a styrene-ethylene-butylene-block copolymer. styrene functionalized with maleic anhydride, and mixtures thereof. The hollow body according to claim 1, characterized in that said layers are contiguous layers of the order of [(Ll) n / (L2) m] x where X is any integer of 1 or greater, n is any integer of 1 or greater, and m is any integer. The hollow body according to claim 1, characterized in that the layer Ll additionally comprises an external lubricant. The hollow body according to claim 13, characterized in that the lubricant 20. The hollow body according to claim 1, characterized in that the hollow body is a hose. The hollow body according to claim 20, characterized in that the hose comprises all or part of a vapor return line or a liquid fuel line. 22. The hollow body according to claim 1, characterized in that the layer Ll additionally comprises an anti-oxidant. 23. The hollow body according to claim 22, characterized in that the anti-oxidant is selected from the group consisting of interrupted phenols, amines, and mixtures thereof. 24. The hollow body according to claim 1, characterized in that it comprises as a single layer, at least one layer Ll and at least one layer L2. 25. The hollow body according to claim 1, characterized in that it comprises, as single layers, a layer Ll and a layer L2. 26. An apparatus energized with fossil fuel characterized in that it comprises the hose according to claim 20. 27. The device energized with fossil fuel according to claim 26, characterized externally is selected from the group consisting of polytetrafluoroethylene, low density polyethylene. , and mixtures thereof. The hollow body according to claim 1, characterized in that the layer Ll additionally comprises a thermal stabilizer comprising at least one copper salt (I) and at least one alkali metal halide. The hollow body according to claim 15, characterized in that the thermal stabilizer comprises at least one copper halide selected from the group consisting of copper iodide and copper bromide and at least one alkali metal halide selected from the group consisting of of iodides and bromides of lithium, sodium, and potassium. 17. The hollow body according to claim 1, characterized in that it comprises as a single layer, at least one layer Ll. 18. The hollow body according to claim 17, characterized in that it comprises, as a single layer, a layer Ll. 19. The hollow body according to claim 17, characterized in that it comprises, as a single layer, at least two layers Ll. because the device energized with fossil fuel is a car. 28. A method for making a hollow body characterized in that it comprises, as single layers, (1) at least one layer Ll comprising an aromatic polyamide and an impact modifier, and, optionally, (2) at least one layer L2 comprising an aliphatic polyamide, which comprises extruding an aromatic polyamide and an impact modifier, and optionally extruding an aliphatic polyamide, through a die. The hollow body according to claim 1, characterized in that at least one layer Ll comprises an aromatic polyamide obtained by means of the polycondensation reaction between hexamethylenediamine and a terephthalic / isophthalic / adipic acid composition where the molar ratio of terephthalic acids / isophthalic / adipic in the acid composition is 50 to 80 / from 10 to 40 / not more than 25, because the impact modifier is selected from the group consisting of a monomeric ethylene-propylene-diene elastomer functionalized with maleic anhydride , a styrene-ethylene-butylene-styrene block copolymer functionalized with maleic anhydride, and mixtures thereof, and because the hollow body is a hose. 30. The hollow body according to claim 1, characterized in that it comprises, as single layers, three layers of L1 / L2 / L1, where Ll is both internal and external layer and L2 is the intermediate layer. 31. The hollow body according to claim 1, characterized in that it comprises, as single layers, two layers of L1 / L2, where Ll is the inner layer. 32. The hollow body according to claim 1, characterized in that it comprises, as single layers, two layers of L2 / L1, where Ll is the outer layer.