Adhesive composition and structure comprising at least one layer of the said composition

Abstract

The invention relates to an adhesive composition comprising at least one polyamide noted A, with a mean number of carbon atoms per nitrogen atom, noted C.sub.A, of between 4 and 8.5 and advantageously between 4 and 7; at least one polyamide noted B, with a melting point of greater than or equal to 180° C. and a mean number of carbon atoms per nitrogen atom, noted C.sub.B, of between 7 and 10 and advantageously between 7.5 and 9.5; at least one polyamide noted C, with a mean number of carbon atoms per nitrogen atom, noted C.sub.C, of between 9 and 18 and advantageously between 10 and 18; at least 50% by weight of the said composition being formed from one or more polyamides chosen from polyamides A, B and C, the mass-weighted mean of the heats of fusion of these polyamides in the said composition being greater than 25 J/g (DSC), the mean number of carbon atoms per nitrogen atom of the polyamides A, B and C also satisfying the following strict inequality: C.sub.A<C.sub.B<C.sub.C, and also to multilayer structures using the said composition.

Claims

1. An adhesive composition comprising: at least one polyamide (A), with a mean number of carbon atoms per nitrogen atom (CA), from 4 and 8.5; at least one polyamide (B), with a melting point of greater than or equal to 180° C. and a mean number of carbon atoms per nitrogen atom(CB), from 7 to 10; and at least one polyamide (C), with a mean number of carbon atoms per nitrogen atom(CC), from 9 to 18; wherein at least 50% by weight of the composition is formed from polyamides A, B and C, wherein said polyamides in the composition have a mass-weighted mean of heats of fusion of greater than 25 J/g (DSC), and wherein polyamide A comprises from 8% to 33% by weight of the total weight of polyamides present in the composition, polyamide B comprises from 34% to 84% by weight of the total weight of polyamides present in the composition, and polyamide C comprises from 8% to 33% by weight of the total weight of polyamides present in the composition and wherein additionally the mean number of carbon atoms per nitrogen atom of each polyamides A, B and C also satisfying the following: CA<CB<CC and (CB−CA) and/or (CC−CB) is from 2 to 3.

2. The composition according to claim 1, wherein polyamide A has a melting point greater than or equal to 210° C. and polyamide C has a melting point that is less than 200° C.

3. The composition according to claim 1, wherein polyamide A is chosen from PA6, PA4.6 and PA6.6, polyamide B is chosen from PA6.10 and PA6.12, and polyamide C is chosen from PA10.10, PA11, PA12, PA10.12 and PA6.18.

4. The adhesive composition of claim 1, wherein the polyamide A has a mean number of carbon atoms per nitrogen atom, CA, from 4 and 7.

5. The adhesive composition of claim 1, wherein the polyamide noted B has a mean number of carbon atoms per nitrogen atom, CB, from 7.5 and 9.5.

6. The adhesive composition of claim 1, wherein the polyamide C has a mean number of carbon atoms per nitrogen atom, CC, from 10 to 18.

7. The adhesive composition of claim 1, which comprises from 50% to 76% by weight of polyamide B relative to the total weight of polyamides present in the composition.

8. A method for transferring or storing a fluid comprising transferring or storing a fluid in a structure prepared, at least in part, from an adhesive composition according to claim 1.

9. The method according to claim 8, wherein the fluid is an oil, a brake fluid, a urea solution, a glycol-based coolant liquid, a non-biofuel, or a biofuel.

10. The composition according to claim 1, wherein each of the polyamides A, B and C has a heat of fusion of greater than 25 J/g (DSC).

11. The composition according to claim 1, wherein the adhesive composition has an adhesion force of at least 60 N/cm.

12. An adhesive composition consisting of: at least one polyamide (A), with a mean number of carbon atoms per nitrogen atom (CA), from 4 to 8.5; at least one polyamide (B), with a melting point of greater than or equal to 180° C. and a mean number of carbon atoms per nitrogen atom (CB), from 7 to 10; at least one polyamide (C), with a mean number of carbon atoms per nitrogen atom(CC), from 9 to 18; wherein said polyamides in the composition have a mass-weighted mean of heats of fusion of greater than 25 J/g (DSC), and wherein polyamide A comprises from 8% to 33% by weight of the total weight of polyamides present in the composition, polyamide B comprises from 34% to 84% by weight of the total weight of polyamides present in the composition, and polyamide C comprises from 8% to 33% by weight of the total weight of polyamides present in the composition and wherein additionally the mean number of carbon atoms per nitrogen atom of each polyamides A, B and C also satisfies the following conditions: CA<CB<CC and (CB−CA) or (CC−CB) is from 2 to 3.

Description

EXAMPLES

(1) Unless otherwise mentioned, the examples are in the form of pipes with an outside diameter of 8 mm and an inside diameter of 6 mm, i.e. a thickness of 1 mm. These dimensions are characteristic of the dimensions of pipes encountered in the motor vehicle field.

(2) These pipes are manufactured by extrusion or coextrusion according to the standard processes for obtaining pipes.

(3) In the attached appendices, “nc” means not communicated.

1/ Comparative Examples

(4) 1.1 Structures of the Counterexamples

(5) The following representative structures of the prior art were prepared and tested:

(6) TABLE-US-00001 1 PA11Cu Binder coPA PA6Oy 2 PA11Cu Binder PPg PA6Oy 3 PA11Cu Binder PA610 + PA6Oy PA6 4 PA11Cu Binder PA612 + PA6Oy PA6 5 PA11Cu Binder PA610 + PA6Oy PA12 6 PA11Cu Binder PA6 + PA6Oy PA12 + imod 7 PA11Cu PA612 PA6Oy 8 PA11Cu PA610 PA6Oy 9 PA11Cu Binder PA610 + PA6Oy PA6 + imod 10 PA11Cu Binder PA610 + EVOH PA6OyE PA12 11 PA11Cu PA612 EVOH PA6OyE 12 PA11Cu PA610 EVOH PA6OyE 13 PA11Cu Binder coPA EVOH PA6OyE 14 PA11Cu PA6a 15 PA11Cu PA610 16 PA11Cu 17 PA6a 18 PPAa 19 EVOH 20 PVDFf 21 PA11Cu PA6a 22 PA11Cu EVOH PA11Cu 23 PA12-TL 24 PA12-TL PPAa 25 PA12-TL PPAb

(7) Each line defines a monolayer structure (structures 16 to 19) or multilayer structure, of which the materials in each of these layers are given the columns. For example, the structure defined on line 8 is a three-layer structure successively comprising a stack of a layer of PA11Cu, on a layer of PA610, which is itself in contact with a layer of PA6Oy. The meaning of the materials used to prepare these structures is given below.

(8) 1.2 Evaluation and Results of the Structures of the Counterexamples

(9) The results of the structures of the counterexamples are given in the table in Appendix 3.

(10) The meanings of the measurements given in the table are as follows:

(11) Column 1: Measurement of the Adhesion Force Expressed in N/cm.

(12) This is reflected by measuring the peel force, expressed in N/cm, and measured on a pipe 8 mm in diameter that has been conditioned for 15 days at 50% relative humidity at 23° C.

(13) The value given concerns the weakest interface, i.e. the least adherent interface of the multilayer, when there is the greatest risk of delamination. Peeling at the interface is performed by subjecting one of the parts to traction at an angle of 90° and at a speed of 50 mm/minute according to the following process.

(14) A strip of pipe 9 mm wide is taken by cutting. This strip is thus in the form of a tile and still has all the layers of the original pipe. Separation of the two layers of the interface, which it is desired to evaluate, is initiated using a knife. Each of the layers thus separated is placed in the jaws of a tensile testing machine. Peeling is performed by pulling these two layers apart at 180° and at a speed of 50 mm/minute. The strip, and thus the interface, is itself maintained at 90° relative to the direction of traction.

(15) The assessment criteria take this into account and are:

(16) VG=very good, >80

(17) G=good, between 80 and >60

(18) Av.=average (acceptable), between 60 and >30

(19) P=poor, between 30 and 10

(20) VP=very poor, <10.

(21) Column 2: Measurement of the Adhesion Force Expressed in N/cm

(22) This test is the same as for column 1, except that the interior of the tube is filled with a biofuel E50 at 80° C. for 200 hours. The biofuel E50 is a mixture comprising, by mass, 50% ethanol, 44% petroleum spirit L, 5% water and 1% methanol according to the standard B31 5220 of the company Peugeot SA, the “L” petroleum spirit being reference lead-free petroleum spirit of the European standard, referenced under the code E-H-003. These test conditions are much more severe than the preceding ones. The assessment criteria take this into account and are:

(23) VG=very good, >40

(24) G=good, >30 to ≦40

(25) Av.=average (acceptable), >20 to ≦30

(26) P=poor, >10 to ≦20

(27) VP=very poor, ≦10.

(28) Column 3: Qualitative Estimation of the Cold Shock Over the Temperature Range, from the Results of Columns 4, 5 and 6.

(29) Scale of qualitative values:

(30) VG=very good

(31) G+=good to very good (G++ between G+ and VG)

(32) G=good

(33) Av.+=average to good

(34) Av.=average (acceptable)

(35) P=poor/insufficient

(36) VP=very poor.

(37) Column 4: Shock Resistance at −30° C.

(38) This is a shock test according to the PSA protocol (company Peugeot SA) according to the standard B21 5540. The pipe is shocked according to this test protocol at −30° C. The percentage of breakage is noted (the lower the better).

(39) Column 5: Shock Resistance at −40° C.

(40) This is a shock test according to the VW protocol (Volkswagen company) according to the standard TL 52435. The tube is shocked according to this test protocol at −40° C. The percentage of breakage is noted.

(41) Column 6: Shock Resistance at −60° C.

(42) This is the same test as previously, but performed at −60° C.

(43) Column 7: Oxidative Ageing

(44) This is the resistance of the multilayer pipe to oxidative ageing in hot air. The pipe is aged in air at 150° C., and is then shocked with a shock according to the standard DIN 73378, this shock being performed at −40° C.: the half-life (in hours) is indicated, which corresponds to the time after which 50% of the tested pipes break. A qualitative comment accompanies this value.

(45) Columns 8 and 9: Efficiency of the Barrier Effect

(46) Column 8 is a qualitative assessment of the barrier effect, this effect being quantified (column 9) via a permeation measurement. The barrier effect is described qualitatively and quantitatively by a permeation measurement. The lower the permeability or permeation, the better the barrier efficiency. This is a measurement of the dynamic permeation (standard PSA B31 5210) in CE10 fuel at 40° C. in g.Math.mm/m.sup.2/24 hours. The fuel CE10 comprises 10% ethanol and 90% petroleum spirit of reference “fluid C”, which is a mixture in equal amounts of isooctane and toluene. The fuel circulates inside the pipe, and air is to the exterior.

(47) Column 10: Resistance to Zinc Chloride (Inner Face of the Pipe on the Joint Side, where the Pipe is Cut).

(48) Measurement of the resistance to zinc chloride is performed according to the standard SAE J2260. The pipes, bent beforehand with a radius of curvature of 40 mm, are immersed in a 50% ZnCl.sub.2 solution. The time after which cracks or the first break appear is noted.

(49) The assessment criteria are as follows:

(50) VG=very good, corresponds to a time ≧1500 hours

(51) G=good, corresponds to a time ≧800 hours

(52) Av.=average, corresponds to a time ≧400 hours

(53) P=poor, corresponds to a time ≦100 hours

(54) VP=very poor, corresponds to a time ≦1 hour.

(55) Column 11: Qualitative and Quantitative Estimation of the Flexibility of the Multilayer Pipe

(56) Good flexibility is advantageous for mounting on a vehicle. The term “good flexibility” means a modulus of flexure of less than 1000 MPa, measured according to the standard ISO178.

(57) VG=300-500 MPa

(58) G+=500-700 MPa

(59) G=700-900 MPa

(60) Av.=900-1200 MPa

(61) P=1500-2000 MPa

(62) VP=>2000 MPa

(63) The structures of the counterexamples illustrate that either the adhesion is insufficient, or the adhesion after immersion in the biofuel is insufficient, or the ageing, or the shock does not satisfy the desired criteria. For counterexample 23, the adhesion is not measured, since the structure is a monolayer.

2/ Examples of Adhesive Composition According to the Invention

(64) The compositions below according to the invention were prepared. The amounts of products are expressed as weight percentages relative to the total weight of the composition.

(65) TABLE-US-00002 1 2 3 4 5 6 7 8 9 PA6.10 45 53 — —   53.3 — 64 28 69 PA6.12 — — 53 — —   53.3 — — — PA6.14 — — — 53 — — — — — PA6 18 18 18 18 18 18 18 18 10 PA12 18 18 18 18 18 18 18 18 10 CoPE/EA/ 10 10 10 10 10 — — — 10 MAH Lotader EPR1 — — — — — 10 — — — hdPEf — — — — — — — 10 — hdPE — — — — — — — 25 — Plasticizer  8 — — — — — — — — Stab1  1  1  1  1 — — —  1  1 StabCu — — — —   0.7   0.7 — — — ΔHf (J/g) 61 61 65 64 61 65 61 62 61 10 11 12 13 14 15 16 17 18 PA6.10 12 12 12 — — — — — PA6.12 — — — 12 12 45 12 12 18 PA6f — — 41 41   41.3 — — — — PA6 24 24 — — — — — — — PA12 45 24 24 24 18 24 24 24 CoPE/EA/ 10 10 10 10 — — — — — MAH Lotader PA11 45 — — — — — — — — EPR1 — — — — 10 10 10 10 10 PPA — — — — — 18 53 — — MXD6 — — — — — — — 53 — amPASA — — — — — — — — 47 Plasticizer  8  8 12 12 12  8 — — — Stab1  1  1  1  1 —  1  1  1  1 StabCu — — — —   0.7 — — — — ΔHf (J/k) 56 57 63 64 64 57 44 52 29

(66) The heats of fusion (ΔHf (J/g)) measured and reported in the above tables correspond to the mass-weighted mean of the heats of fusion of the polyamides present in the compositions. They are measured by DSC (Differential Scanning calorimetry) as defined above.

(67) The adhesive compositions 1 to 18 are prepared according to the method that is common to those skilled in the art, by compounding, i.e. they are mixed together in molten form in an extruder, typically a Werner & Pfleiderer twin-screw extruder.

(68) These adhesive compositions may be intended for making an adhesive layer within multilayer structures, such as those of the examples given in Appendix 1.

(69) There is an alternative to this method. It consists in using the adhesive composition according to the invention as additive in a layer of non-adhesive material. To do this, after having prepared an adhesive composition conventionally by compounding, the said adhesive composition is mixed in the desired amount with a non-adhesive composition, which constitutes one of the non-adhesive layers of the multilayer structure. This mixture prepared in the solid state by combining the two compositions is known as a “dry blend”.

(70) This technique allows a non-adhesive layer to be given the desired adhesion. This technique has the advantage of reducing the number of layers necessary for the multilayer structure.

(71) This technique (dry-blend) may lead to an adhesive composition according to the invention, since the characteristics of the composition according to the invention before mixing are concerned after mixing.

(72) The following compositions are obtained from dry-blend mixing and are, after mixing, compositions according to the invention:

(73) Composition 19:

(74) PA12-TL+20% of the adhesive composition 1 (base PA610)

(75) Composition 20:

(76) PA12-TL+20% of the adhesive composition 3 (base PA6)

(77) Composition 21

(78) PA6a+20% of the adhesive composition 1 (base PA610)

(79) Composition 22

(80) PPAa+20% of the adhesive composition 1 (base PA610)

(81) Composition 23

(82) PPAa+20% of the adhesive composition 11 (base PA12)

(83) All these examples of compositions obtained via the dry-blend technique are compositions comprising at least three polyamides C.sub.A, C.sub.B, C.sub.C, which are appropriately different and which satisfy the criteria of the invention.

3/ Evaluation and Results of the Adhesive Compositions 1 to 18 According to the Invention

(84) Compositions 1 to 18 defined in the above table were subjected to the shock performance test described above for columns 3 to 6 of Appendix 3 of the tests performed for the structures of the counterexamples.

(85) For some of these compositions, the modulus of flexure and the MFI are measured.

(86) TABLE-US-00003 1 2 3 4 5 6 7 8 9 Shock G VG VG VG VG VG Av. B nc performance PSA-30° C. 0 0 0 0 0 0 10 0 nc VW-40° C. 76.6 43.3 60 20 38 10 100 80 nc VW-60° C. 100 100 100 100 100 100 100 100 nc Modulus of 350 810 830 740 815 800 nc 1100 960 flexure MFI 235° C. 5 kg 2 0.7 0.8 0.7 0.6 0.7 nc 2.8 0.4 10 11 12 13 14 15 16 17 18 Shock VG G G G G Av. nc nc nc performance PSA-30° C. 0 0 0 0 0 0 nc nc nc VW-40° C. 0 33 47 53 40 80 nc nc nc VW-60° C. 30 100 100 100 100 100 nc nc nc Modulus of 300 350 340 350 335 680 1500 1600 1450 flexure MFI 235° C. 5 kg 8 2 15 14 17 nc — — 2.5 MFI 275° C. 5 kg — — — — — — — 5 — MFI 300° C. — — — — — — 12 — — 5 kg

(87) For these composition examples 1 to 18, the described properties correspond to the same definitions as for the tables in Appendix 2 and Appendix 3.

5/ Examples of Multilayer Structures

(88) Examples of multilayer structures according to the invention are collated in the table of Appendix 1.

(89) The results for the multilayer structures according to the invention featured in the table of Appendix 1 are given in the table of Appendix 2: the results reported in the columns correspond to the measurements defined above with the additional column 12.

(90) Column 12: Antistatic Character

(91) This column indicates the antistatic character on the inner face of the multilayer pipe. The antistatic character is occasionally required in the specifications for certain countries. This character conventionally corresponds to a superficial resistivity value of less than or equal to 10.sup.6 ohms. This character may thus be an additional advantage in certain countries.

(92) The components of the structures used in examples have the following meanings:

(93) PA6.10 meaning Polyamide 6.10 of Mn (number-average molecular mass) 30 000 and having an excess of amine NH2 chain end relative to the COOH chain end, the concentration of NH2 chain end being 45 μeq/g. Its melting point is 223° C. and its heat of fusion is 61 kJ/kg.

(94) PA6.12 meaning Polyamide 6.12 of Mn (number-average molecular mass) 29 000 and having an excess of amine NH2 chain end relative to the COOH chain end, the concentration of NH2 chain end being 47 μeq/g. Its melting point is 218° C. and its heat of fusion is 67 kJ/kg.

(95) PA6.14 meaning Polyamide 6.14 of Mn (number-average molecular mass) 30 000 and having an excess of amine NH2 chain end relative to the COOH chain end, the concentration of NH2 chain end being 45 μeq/g. Its melting point is 202° C. and its heat of fusion is 66 kJ/kg.

(96) PA6 meaning Polyamide 6 of Mn (number-average molecular mass) 28 000. Its melting point is 220° C. and its heat of fusion is 68 kJ/kg.

(97) PA6f means Polyamide 6 of Mn (number-average molecular mass) 18 000. Its melting point is 220° C.

(98) PA12 meaning Polyamide 12 of Mn (number-average molecular mass) 35 000. Its melting point is 178° C. and its heat of fusion is 54 kJ/kg.

(99) PA11 meaning Polyamide 11 of Mn (number-average molecular mass) 29 000. Its melting point is 190° C. and its heat of fusion is 56 kJ/kg.

(100) PA11Cu denotes a composition based on polyamide 11 of Mn (number-average molecular mass) 29 000, containing 5% plasticizer BBSA (benzyl butyl sulfonamide), 6% impact modifier of ethylene/ethyl acrylate/anhydride type in a 68.5/30/1.5 mass ratio (MFI 6 at 190° C. under 2.16 kg) and 0.5% stabilizer based on copper iodide and potassium iodide of Polyadd P201 type (from Ciba). The melting point of this composition is 185° C.

(101) PA1210T-Cu denotes a coPA12/10.T, i.e. a copolyamide 12 with 50 mol % of 10.T, 10.T corresponding to the C10 linear diamine and T to terephthalic acid, this copolymer being of Mn 20 000, this copolymer being stabilized with 0.5% stabilizer based on copper iodide and potassium iodide of Polyadd P201 type (from Ciba).

(102) PA1010Cu denotes a composition based on polyamide 10.10 of Mn (number-average molecular mass) 33 000, containing 10.5% plasticizer BBSA (benzyl butyl sulfonamide), 12% anhydride-functionalized EPR Exxelor VA1801 (from Exxon) and 0.5% stabilizer based on copper iodide and potassium iodide of Polyadd P201 type (from Ciba). The melting point of this composition is 196° C.

(103) PA11-TL denotes a composition based on polyamide 11 of Mn (number-average molecular mass) 29 000, containing 5% plasticizer BBSA (benzyl butyl sulfonamide), 6% impact modifier of ethylene/ethyl acrylate/anhydride type in a 68.5/30/1.5 mass ratio (MFI 6 at 190° C. under 2.16 kg), and 1.2% organic stabilizers constituted of 0.8% phenol (Lowinox 44B25 from the company Great Lakes), 0.2% phosphite (Irgafos 168 from the company Ciba) and 0.2% UV stabilizer (Tinuvin 312 from the company Ciba). The melting point of this composition is 185° C.

(104) PA12-TL denotes a composition based on polyamide 12 of Mn (number-average molecular mass) 35 000, containing 6% plasticizer BBSA (benzyl butyl sulfonamide), 6% anhydride-functionalized EPR Exxelor VA1801 (from Exxon), and 1.2% organic stabilizers constituted of 0.8% phenol (Lowinox 44B25 from the company Great Lakes), 0.2% phosphite (Irgafos 168 from the company Ciba and 0.2% UV stabilizer (Tinuvin 312 from the company Ciba). The melting point of this composition is 175° C.

(105) PA6a denotes a composition based on polyamide 6 of Mn (number-average molecular mass) 28 000, containing 10% plasticizer BBSA (benzyl butyl sulfonamide), 12% functionalized EPR Exxelor VA1803 (from Exxon) and 1.2% organic stabilizers constituted of 0.8% phenol (Lowinox 44B25 from the company Great Lakes), 0.2% phosphite (Irgafos 168 from the company Ciba) and 0.2% UV stabilizer (Tinuvin 312 from the company Ciba). The melting point of this composition is 215° C.

(106) PA6pl denotes a composition based on polyamide 6 of Mn (number-average molecular mass) 18 000, containing 12% plasticizer BBSA and 1.2% organic stabilizers constituted of 0.8% phenol (Lowinox 44B25 from the company Great Lakes), 0.2% phosphite (Irgafos 168 from the company Ciba) and 0.2% UV stabilizer (Tinuvin 312 from the company Ciba). The melting point of this composition is 215° C.

(107) PA6Oy denotes an alloy composed of a matrix made of polyamide 6 of Mn 18 000 (for example Ultramid B3 from the company BASF) and 30% hdPE (high-density polyethylene) of density 0.96 and of melt flow index 0.3 (at 190° C. under 2.16 kg), 7% hdPE functionalized by grafting with 1% maleic anhydride, with a melt flow index of 1 (at 190° C. under 2.16 kg), 1.2% organic stabilizers (constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes), 0.2% phosphite Irgafos 168 from the company Ciba, and 0.2% UV stabilizer Tinuvin 312 from the company Ciba), the whole making 100%. The melting point of this composition is 220° C.

(108) PA6OyE denotes an alloy composed of a matrix made of polyamide 6 of Mn 18 000 (for example Ultramid B3 from the company BASF) and 25% hdPE (high-density polyethylene) of density 0.96 and of melt flow index 0.3 (at 190° C. under 2.16 kg), 10% functionalized EPR Exxelor VA1803 (from Exxon), 8% plasticizer BBSA (benzyl butyl sulfonamide), and 1.2% organic stabilizers constituted of 0.8% phenol (Lowinox 44B25 from the company Great Lakes), 0.2% phosphite (Irgafos 168 from the company Ciba) and 0.2% UV stabilizer (Tinuvin 312 from the company Ciba), the whole making 100%. The melting point of this composition is 220° C.

(109) PA11Impact-TL denotes a composition based on polyamide 11 of Mn (number-average molecular mass) 29 000, containing 20% impact modifier of ethylene/ethyl acrylate/anhydride type in a 68.5/30/1.5 mass ratio (MFI 6 at 190° C. under 2.16 kg), and 1.2% organic stabilizers constituted of 0.8% phenol (Lowinox 44B25 from the company Great Lakes), 0.2% phosphite (Irgafos 168 from the company Ciba) and 0.2% UV stabilizer (Tinuvin 312 from the company Ciba). The melting point of this composition is 190° C.

(110) PA11-C denotes a composition based on polyamide 11 of Mn (number-average molecular mass) 29 000, containing 10% plasticizer BBSA (benzyl butyl sulfonamide), 22% carbon black Ensaco 200 and 1.2% organic stabilizers (constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes, 0.2% phosphite Irgafos 168 from the company Ciba, and 0.2% UV stabilizer Tinuvin 312 from the company Ciba). The melting point of this composition is 185° C.

(111) PA1210T-TL denotes a coPA12/10.T, i.e. a copolyamide 12 with 50 mol % of 10.T, 10.T corresponding to the linear C.sub.10 diamine and T to terephthalic acid, this copolymer being of Mn 20 000, this copolymer being stabilized with 1.2% organic stabilizers constituted of 0.8% phenol (Lowinox 44B25 from the company Great Lakes), 0.2% phosphite (Irgafos 168 from the company Ciba) and 0.2% UV stabilizer (Tinuvin 312 from the company Ciba).

(112) PA11Impact denotes a composition based on polyamide 11 of Mn (number-average molecular mass) 29 000, containing 20% impact modifier of the ethylene/ethyl acrylate/anhydride type in a 68.5/30/1.5 mass ratio (MFI 6 at 190° C. under 2.16 kg), and 0.5% stabilizer based on copper iodide and potassium iodide of Polyadd P201 type (from Ciba). The melting point of this composition is 190° C.

(113) PA11pl denotes a composition based on polyamide 11 of Mn (number-average molecular mass) 35 000, containing 12% plasticizer BBSA (benzyl butyl sulfonamide) and 1.2% organic stabilizers (constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes, 0.2% phosphite Irgafos 168 from the company Ciba, and 0.2% UV stabilizer Tinuvin 312 from the company Ciba). The melting point of this composition is 185° C.

(114) PA12-Cu denotes a composition based on polyamide 12 of Mn (number-average molecular mass) 35 000, containing 6% plasticizer BBSA (benzyl butyl sulfonamide), 6% anhydride-functionalized EPR Exxelor VA1801 (from Exxon) and 0.5% stabilizer based on copper iodide and potassium iodide of Polyadd P201 type (from Ciba). The melting point of this composition is 175° C.

(115) MXD.6 means Polyamide of MXD.6 type, MXD denoting m-xylylenediamine, of Mn 25 000, with a melting point of 237° C. and a heat of fusion of 46 kJ/kg. This type of polyamide is sold, for example, by the company Mitsubishi under the name MX Nylon.

(116) MXD6hi denotes a composition based on copolyamide of MXD.6 type and impact modifier, sold under the name Ixef BXT-2000 by the company Solvay. Its melting point is 237° C.

(117) PPA means polyphthalamide of copolyamide 6T/6 type of 71%/29% mass proportion, of Mn 13 500, also sold under the name Ultramid TKR4351 by the company BASF. Its melting point is 295° C. and its heat of fusion is 34 kJ/kg.

(118) PPAa denotes a composition based on polyphthalamide of coPA6.T/6.I/6.6, Amodel EXT1800 from the company Solvay. The melting point of this composition is 310° C.

(119) PPAb denotes a composition based on polyphthalamide of copolyamide 6.T/6 type, Ultramid TKR4351 from the company BASF, and 25% functionalized EPR Exxelor VA1803 (from Exxon), and 0.5% stabilizer based on copper iodide and potassium iodide of Polyadd P201 type (from Ciba). The glass transition temperature of this amorphous composition is 295° C.

(120) amPASA means polyphthalamide of coPA6.I/6.T copolyamide type, containing 70% by mass of unit 6.1, and of Mn 14 000. This product is amorphous, and its glass transition temperature Tg is 125° C.

(121) amPASAa denotes a polyphthalamide-based composition of the copolyamide coPA6.I/6.T type, containing 70% by mass of unit 6.1, and 25% functionalized EPR Exxelor VA1803 (from Exxon) and 0.5% stabilizer based on copper iodide and potassium iodide of Polyadd P201 type (from Ciba). The glass transition temperature of this amorphous composition is 115° C.

(122) coPE/EA/MAH meaning Ethylene-ethyl acrylate-maleic anhydride copolymer in a 68.5/30/1.5 mass ratio (MFI 6 at 190° C. under 2.16 kg) used as impact modifier. Its modulus of flexure is 30 MPa approximately, according to the standard ISO 178.

(123) EPR1 denoting a copolymer of ethylene and propylene of elastomeric nature functionalized with a group that is reacted with an anhydride function (at 0.5-1% by mass), of MFI 9 (at 230° C., under 10 kg), of the type Exxellor VA1801 from the company Exxon, used as impact modifier. Its modulus of flexure is 10 MPa approximately, according to the standard ISO 178.

(124) hdPE denotes a high-density polyethylene, of density 0.962, with a melting point of 136° C., of MFI at 190° C. under 2.16 kg of 0.6.

(125) hdPEf denoting a high-density polyethylene functionalized with a reactive group that can react with one of the chain ends (or other reactive functions) of the polyamide, of density 0.960, of melting point 134° C., and of MFI, at 190° C. under 2.16 kg, of 2.

(126) Stab1 denoting a mixture of organic stabilizers constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes and 0.2% phosphite Irgafos 168 from the company Ciba.

(127) StabCu denoting a mixture of mineral stabilizers based on copper iodide and potassium iodide of Polyadd P201 type (from Ciba).

(128) Plasticizer denoting benzyl butyl sulfonamide (BBSA).

(129) EVOH denotes an ethylene-vinyl alcohol copolymer, for example Soarnol DC3203RB from the company Nippon Gosei. The melting point of this composition is 183° C.

(130) EVOHim denotes a composition based on EVOH and functionalized EPR impact modifier Exxelor VA1803 (from Exxon). The melting point of this composition is 183° C.

(131) EVOH100 denotes an ethylene-vinyl alcohol copolymer containing 24% ethylene comonomer, manufactured by the company Eval under the name Eval M100B. The melting point of this composition is 194° C.

(132) PVDFf denotes a composition based on PVDF functionalized with maleic anhydride. The melting point of this composition is 170° C.

(133) ETFE denotes a composition based on ETFE (ethylene-tetrafluoroethylene copolymer) known under the name EP7000, from the company Daikin. The melting point of this composition is 255° C.

(134) EFEP-C denotes an antistatic composition based on EFEP (ethylene-tetrafluoroethylene-hexafluoropropylene copolymer) known under the name RP5000AS, from the company Daikin. The melting point of this composition is 195° C.

(135) Binder coPA denotes a composition based on 40% copolyamide 6/12 (of ratio 70/30 by mass) of Mn 16 000, and 40% copolyamide 6/12 (of ratio 70/30 by mass) of Mn 16 000.

(136) Binder PPg denotes a composition based on PP (polypropylene) grafted with maleic anhydride, known under the name Admer QF551A from the company Mitsui.

(137) Binder PA610+PA6 denotes a composition based on PA610 (of Mn 30 000, and as defined elsewhere) and 36% PA6 (of Mn 28 000, and as defined elsewhere) and 1.2% organic stabilizers (constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes, 0.2% phosphite Irgafos 168 from the company Ciba, and 0.2% UV stabilizer Tinuvin 312 from the company Ciba).

(138) Binder PA612+PA6 denotes a composition based on PA612 (of Mn 29 000, and as defined elsewhere) and 36% PA6 (of Mn 28 000, and as defined elsewhere) and 1.2% organic stabilizers (constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes, 0.2% phosphite Irgafos 168 from the company Ciba, and 0.2% UV stabilizer Tinuvin 312 from the company Ciba).

(139) Binder PA610+PA12 denotes a composition based on PA610 (of Mn 30 000, and as defined elsewhere) and 36% PA12 (of Mn 35 000, and as defined elsewhere) and 1.2% organic stabilizers (constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes, 0.2% phosphite Irgafos 168 from the company Ciba, and 0.2% UV stabilizer Tinuvin 312 from the company Ciba).

(140) Binder PA6+PA12+imod denotes a composition based on 40% PA6 (of Mn 28 000, and as defined elsewhere), 40% PA12 (of Mn 35 000, and as defined elsewhere) and 20% functionalized EPR Exxelor VA1801 (from Exxon) and 1.2% organic stabilizers (constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes, 0.2% phosphite Irgafos 168 from the company Ciba, and 0.2% UV stabilizer Tinuvin 312 from the company Ciba).

(141) Binder PA610+PA6+imod denotes a composition based on 40% PA6.10 (of Mn 30 000, and as defined elsewhere), 40% PA6 (of Mn 28 000, and as defined elsewhere) and 20% impact modifier of ethylene/ethyl acrylate/anhydride type in a 68.5/30/1.5 mass ratio (MFI 6 at 190° C. under 2.16 kg), and 1.2% organic stabilizers (constituted of 0.8% phenol Lowinox 44B25 from the company Great Lakes, 0.2% phosphite Irgafos 168 from the company Ciba, and 0.2% UV stabilizer Tinuvin 312 from the company Ciba).

(142) Example of Manufacture of Multilayer Structures: In the Case of Pipes

(143) The multilayer pipes are prepared by coextrusion. A McNeill industrial multilayer extrusion line, equipped with five extruders, connected to a spiral-mandrel multilayer extrusion head, is used.

(144) The screws used are single extrusion screws having pitch profiles adapted to polyamides. In addition to the five extruders and the multilayer extrusion head, the extrusion line comprises: a die-punch assembly, located at the end of the coextrusion head; the inside diameter of the die and the outside diameter of the punch are chosen as a function of the structure to be produced and of the materials of which it is composed, and also of the dimensions of the pipe and the line speed; a vacuum box with an adjustable pressure-reduction level. In this box circulates water generally maintained at 20° C., in which is immersed a gauge for conforming the pipe in its final dimensions. The diameter of the gauge is adapted to the dimensions of the pipe to be made, typically from 8.5 to 10 mm for a pipe with an outside diameter of 8 mm and a thickness of 1 mm; a succession of cooling tanks in which water is maintained at about 20° C., for cooling the pipe along the path from the head to the drawing bench; a diameter measurer; a drawing bench.

(145) The 5-extruder configuration is used to produce pipes having from two layers to five layers. In the case of structures with less than five layers, several extruders are then fed with the same material.

(146) In the case of the structures comprising six layers, an additional extruder is connected and a spiral mandrel is added to the existing head, in order to produce the inner layer, in contact with the fluid.

(147) Before the tests, in order to ensure that the pipe has the best properties and good extrusion quality, it is checked that the extruded materials have a residual moisture content before extrusion of less than 0.08%. If this is not the case, an additional step of drying the material is performed before the tests, generally in a vacuum dryer, overnight at 80° C.

(148) Reference will be made to Appendix 4, which presents in detail the extrusion parameters used for Examples 33 (5 layers), 18 (4 layers) and 2 (3 layers) of Appendix 1, for the manufacture of pipes with an outside diameter of 8 mm and an inside diameter of 6 mm, i.e. a thickness of 1 mm.

(149) For these three particular examples, as for all the others, the pipes, which satisfy the characteristics described in the present patent application, were taken, after stabilization of the extrusion parameters, the nominal dimensions of the pipes no longer changing over time. The diameter is checked by a laser diameter measurer installed at the end of the line.

(150) Generally, the line speed is typically 20 m/minute. It generally ranges between 5 and 100 m/minute.

(151) The speed of the extruder screws depends on the thickness of the layer and on the diameter of the screw, as is known to those skilled in the art.

(152) In general, the temperature of the extruders and tools (head and joint) should be set so as to be sufficiently higher than the melting point of the compositions under consideration, such that they remain in molten form, thus preventing them from solidifying and blocking the machine.

(153) For the compositions PA11, PA12, PA6, PA610, PA612, PA614, MDX6, EVOH, PVDF and amPASA, a temperature of about 240° C., or even up to 260° C. if the product is particularly viscous, should be ensured. To do this, at least part of the heating zones of the machine, in particular the part downstream of the screw and the downstream tools (extrusion head and joint) is set at about 240° C., so as to obtain the nominal mix temperature.

(154) For the compositions based on PA1210T or on ETFE, the process should be performed at about 270° C. For the compositions based on PPA or PPAa, the process should be performed at about 310° C. For the compositions based on PPAb, the process should be performed at about 320° C.

(155) Examples of multilayer structures prepared using the “dry-blend” method are given in Appendix 1. It may be illustrated by Example 83, which may be compared with Example 53. Instead of adding the adhesive composition 13 in the form of a layer of binder to make the “PA12-TL” layer adhere to the “PPAb” layer, this adhesive composition 13 is added into the “PA12-TL” layer, which gives the latter the capacity of adhering to the “PPAb” layer. To do this, just before manufacturing the multilayer pipe, the granules of the composition “PA12-TL” are mixed with 20% of granules of the adhesive composition 13. This mixture is then introduced into the multilayer extruder. This mixing then combines the roles of tough outer layer (III) and adhesive layer (I).

(156) Comments Concerning the Properties of Certain Structures

(157) The adhesive compositions in which the predominant polyamide is a polyamide of the type C.sub.A offer certain advantages. Thus, in Examples 56 and 69, the intermediate binder layer also acts as barrier or semi-barrier layer (layer of type II or IV). Thus, by comparison of structures 52 and 57, the layer of “PA6a” may be replaced with a layer of binder, of equivalent thickness. Thus, an adhesive composition (binder), in which the predominant polyamide is a polyamide of the type C.sub.A (composition 12 to 14, 16 to 18) combines both the character of binder and of barrier layer (the barrier layers of the type “PA6a”, “PA6OyE” and “PPAa” not adhering to the “tough” layers based on polyamide C.sub.C such as “PA12-TL”). It is thus advantageous to use adhesive compositions in which the predominant polyamide is a polyamide of the type C.sub.A, and in thicknesses that are large enough to be able to benefit from the barrier effect or from a surplus of this effect.

(158) The structures of Examples 64 and 65 illustrate the surplus efficiency in terms of permeability (increased barrier effect) by using this type of adhesive composition, in which the predominant polyamide is a polyamide of the type C.sub.A and in particular of highly barrier type such as a “PPA” or an “MAXD.6”.

(159) Noteworthy synergism may also be observed. For example, the multilayer pipe 69 has, relative to its controls, on the one hand, the mono-material pipe “PA12-TL”: counterexample 23, and, on the other hand, the mono-material pipe of adhesive composition 13, impact and barrier advantages, without, however, presenting any disadvantages in terms of flexibility or resistance to ageing, at the risk of loss of adhesion between the layers. The multilayer pipes 70 and 71 are also very advantageous, when compared with the monolayer pipes: counterexample 23 and adhesive compositions 13 and 14, not only in terms of impact and barrier, but also in terms of ageing. The pipe of examples 60 also shows an advantageous profile of properties.

(160) Multilayer structures in which the binder comprises as predominant polyamide a polyamide of the type C.sub.C are also featured among the examples. The advantage then becomes that of combining the functions of binder layer (layer of type I) and of tough layer (layer of type III). Specifically, a good proportion of the flexibility, impact, zinc chloride resistance and ageing resistance qualities of a tough layer of the type III are conserved. It is thus possible for such a binder to act as the outer layer.

(161) TABLE-US-00004 APPENDIX 1 III I II 1 PA11Cu Adhesive PA6a thicknesses composition 2 475/50/475 μm 2 PA11Cu Adhesive PA6Oy composition 2 3 PA1210T- Adhesive PA6Oy Cu composition 2 4 PA1010Cu Adhesive PA6Oy composition 3 5 PA11Cu Adhesive PA6OyE composition 2 6 PA11-TL Adhesive PA6OyE composition 2 7 PA12-TL Adhesive PA6OyE composition 2 8 PA11Cu Adhesive PA6OyE composition 3 9 PA11Cu Adhesive PA6OyE composition 1 10 PA11Cu Adhesive PA6OyE composition 8 11 PA11Cu Adhesive PA6OyE composition 7 12 PA11Cu Adhesive PPAa composition 2 13 PA11Cu Adhesive PPAb composition 2 14 PA1210T- Adhesive PPAb Cu composition 2 III I II II 15 PA11Cu Adhesive PPAa PA6OyE thicknesses composition 2 425/50/100/425 μm 16 PA11Cu Adhesive PPAb PA6OyE composition 2 17 PA11Cu Adhesive amPASAa PA6OyE composition 2 18 PA11Cu Adhesive EVOH PA6OyE composition 2 19 PA11Cu Adhesive EVOH PA6OyE composition 9 20 PA11Cu Adhesive EVOHim PA6OyE composition 2 III I II I 21 PA11Cu Adhesive PA6Oy Adhesive composition 2 thicknesses 475/50/325/150 μm composition 2 III I II I III 22 PA11Cu Adhesive PA6Oy Adhesive composition 2 PA11-TL thicknesses 225/50/450/50/225 μm composition 2 23 PA11Cu Adhesive PPAb Adhesive composition 2 PA11-TL thicknesses 390/50/120/50/390 μm composition 2 24 PA11Cu Adhesive amPASAa Adhesive composition 2 PA11-TL composition 2 25 PA11Cu Adhesive PA6Oy Adhesive composition 2 PA1210T-TL composition 2 III I II II I III 26 PA11Cu Adhesive EVOH PA6OyE Adhesive PA11-TL thicknesses composition 2 composition 2 225/50/100/350/ 50/225 μm III III I II 27 PA11Cu PA11Impact Adhesive PA6Oy thicknesses composition 2 375/50/50/425 μm III I II II 28 PA11Cu Adhesive PA6Oy PA6a thicknesses composition 2 425/50/375/50 μm III I II 29 PA11Impact Adhesive PA6Oy thicknesses composition 2 425/50/425 μm 30 PA11Impact Adhesive PA6OyE composition 2 III I 31 PA11Cu Adhesive thickness 500/500 μm composition 8 III I III 32 PA11Cu Adhesive PA11-TL thickn. 250/500/250 μm composition 8 III I II I III 33 PA11Cu Adhesive EVOH Adhesive composition 2 PA11-TL thickn. 400/50/100/50/400 composition 2 34 PA12-Cu Adhesive EVOH Adhesive composition 2 PA11-TL composition 2 35 PA11Impact Adhesive EVOH Adhesive composition 2 PA11Impact-TL composition 2 36 PA11Cu Adhesive EVOHim Adhesive composition 2 PA11-TL composition 2 37 PA11Cu Adhesive EVOHim Adhesive composition 2 PA11-CondTL composition 2 III I II I III III 38 PA11Cu Adhesive EVOH Adhesive composition 2 PA11Impact PA11-CondTL thickn. composition 2 400/50/100/ 50/325/75 III I II I III 39 PA11Cu Adhesive PVDFf Adhesive composition 2 PA11-TL thickn. 400/50/100/50/400 composition 2 III I II I II 40 PA11Cu Adhesive PVDFf Adhesive composition 2 PA6OyE thickn. 400/50/100/50/400 composition 2 III I II 41 PA11Cu Adhesive PVDFf thickn. 750/50/200 composition 2 42 PA11Cu Adhesive ETFE composition 2 43 PA11Cu Adhesive EFEP-C thickn. 750/50/50/100 composition 2 pb 4 layers I II 44 Adhesive PA6Oy thicknesses 500/500 μm composition 8 45 Adhesive PPAa thicknesses 500/500 μm composition 5 I II I 46 Adhesive PA6Oy Adhesive thicknesses composition 2 composition 2 250/500/250 μm 47 Adhesive PA6Oy Adhesive composition 4 composition 4 48 Adhesive EVOH Adhesive composition 2 composition 2 I II 49 Adhesive PVDFf thicknesses 900/100 μm composition 2 I II I 50 Adhesive PPAa Adhesive thicknesses composition 2 composition 2 250/500/250 μm III I II IV 51 PA12-TL Adhesive composition 13 thicknesses 500/500 μm 52 PA12-TL Adhesive composition 13 PA6a thicknesses 500/100/400 μm 53 PA12-TL Adhesive composition 13 PPAb thicknesses 650/100/250 μm 54 PA12-TL Adhesive composition 13 MXD6hi ″ 55 PA12-TL Adhesive composition 13 EVOH PA6OyE thicknesses 350/100/100/450 μm 56 PA12-TL Adhesive composition 13 EVOH Adh. Comp. 13 thicknesses 350/100/100/450 μm 57 PA12-TL Adhesive composition 13 EVOH PA6a thicknesses 350/100/100/450 μm III I II I III 58 PA12-TL Adhesive composition 13 EVOH Adh. Comp. 13 PA12-TL thicknesses 250/200/100/200/250 μm 59 PA12-TL Adhesive composition 12 EVOH Adh. Comp. 12 PA12-TL thicknesses 250/200/100/200/250 μm 60 PA11Cu Adhesive composition 12 EVOH Adh. Comp. 12 PA11-TL thicknesses 250/200/100/200/250 μm 61 PA11-TL Adhesive composition 12 EVOH100 Adh. Comp. 12 PA11-TL thicknesses 150/300/100/300/150 μm 62 PA12-TL Adhesive composition 13 PPA Adh. Comp. 13 PA12-TL thicknesses 250/150/200/150/250 μm III I II I II/IV 63 PA12-TL Adhesive composition 13 EVOH Adhesive PPAb thicknesses 250/200/100/300/150 μm composition 13 III I/II II I/II III 64 PA12-TL Adhesive composition 17 EVOH Adhesive PA12-TL thicknesses 350/100/100/100/350 μm composition 17 65 PA12-TL Adhesive composition 18 EVOH Adhesive PA12-TL thicknesses 350/100/100/100/350 μm composition 18 III I/II 66 PA12-TL Adhesive composition 16 thicknesses 650/350 μm III I IV III 67 PA12-TL Adhesive composition 13 PA6a PPAb thicknesses 250/100/400/250 μm III I III IV 68 PA12-TL Adhesive composition 13 PPAb PA6a thicknesses 250/100/250/400 μm III I/II III 69 PA12-TL Adhesive composition 13 PA12-TL thicknesses 250/500/250 μm 70 PA11Impact-TL Adhesive composition 13 PA11Impact-TL thicknesses 250/500/250 μm 71 PA11Impact-TL Adhesive composition 14 PA11Impact-TL thicknesses 250/500/250 μm III I II I III 72 PA11pl Adhesive composition 13 EVOH Adhesive PA11-C thicknesses 250/200/100/200/250 μm composition 13 III/I II IV 73 Adhesive PA6a thicknesses 500/500 μm composition 11 74 Adhesive PPAb thicknesses 750/250 μm composition 11 75 Adhesive EVOH PA6OyE thicknesses 450/100/450 μm composition 11 III/I II III/I 76 Adhesive EVOH Adhesive ″ composition 11 composition 11 III/I II IV/I 77 Adhesive EVOH Adhesive ″ composition 11 composition 13 78 Adhesive PPA Adhesive thicknesses 400/200/400 μm composition 11 composition 13 III/I II II/IV III 79 Adhesive EVOH MXD6hi Adhesive thicknesses 400/100/100/400 μm composition 11 composition 11 III/I II III/I 80 Adhesive PA6pl Adhesive thicknesses 250/500/250 μm composition 11 composition 11 III/I IV II IV III/I 81 Adhesive PA6pl EVOH PA6pl Adhesive thicknesses 250/200/100/200/250 μm composition 11 composition 11 “dry-blend” III + I II 82 Composition 19 = PA12-TL + 20% Adh. comp. 1 PPAb thicknesses 750/250 μm 83 Composition 20 = PA12-TL + 20% Adh. comp. 13 PPAb ″ III I II I III 84 PA12-TL Composition 21 = PA6a + EVOH Composition 21 PA12-TL thicknesses 250/200/100/200/250 μm 20% Adh. comp. 1 III I + II 85 PA12-TL Composition 22 = PPAa + 20% Adh. comp. 1 86 PA12-TL Composition 23 = PPAa + 20% Adh. comp. 11

(162) TABLE-US-00005 APPENDIX 2 Evaluation of the structures according to the invention: 1 2 3 4 5 6 7 8 9 10 11 12 1 VG, >80 G, >30 G+ 0 0 38  Av. >250 Av. 190 VP G+ nc 2 VG, >80 G, >30 G 0 37  73  VG >1000 G+ 35 P G nc 3 VG, >80 G, >30 G 0 nc nc G >500 G++ <30 P G nc 4 nc nc G 0 nc nc G >500 nc nc P G nc 5 VG, >80 G, >30 G+ 0 0 27  G >1000 G 55 P G+ nc 6 VG, >80 G, >30 G+ 0 0 30  Av. >250 G 55 P G+ nc 7 VG, >80 G, >30 G 0 33  60  Av. >250 G 60 P G+ nc 8 G, >60 Av., >25 G 0 0 60  VG >1000 G 57 P G+ nc 9 VG, >80 G, >30 G+ 0 0 33  VG >1000 G 57 P G+ nc 10 G, >60 G, >30 G 0 0 60  VG >1000 G 52 P G+ nc 11 G, >60 G, >30 G 0 0 50  VG >1000 G 54 P G+ nc 12 G, >60 G, >30 G 0 nc nc Av. >250 G++ <30 Av. Av. nc 13 G, >60 G, >30 G 0 nc nc Av. >250 G++ <30 Av. Av. nc 14 G, >60 G, >30 G 0 nc nc Av. >250 G++ <30 Av. Av. nc 15 G, >60 G, >30 G 0 nc nc Av. >250 G++ <30 P Av. nc 16 G, >60 G, >30 G 0 nc nc Av. >250 G++ <30 P Av. nc 17 G, >60 Av., >25 G 0 nc nc Av. >250 G++ <30 P Av. nc 18 VG, >80 G, >30 VG 0 0 3 Av. >250 VG <10 P G nc 19 G, >60 Av., >25 VG 0 0 nc nc nc nc Nc nc nc 20 VG, >80 G, >30 VG 0 0 0 Av. >250 VG <10 P G+ nc 21 VG, >80 G, >30 G 0 nc nc G >500 G+ 45 Av. G nc 22 VG, >80 G, >30 VG 0 0 0 VG >1000 G+ 41 VG G nc 23 VG, >80 G, >30 VG 0 0 0 VG >1000 VG <30 VG Av. nc 24 VG, >80 G, >30 VG 0 0 0 VG >1000 VG <30 VG Av. nc 25 VG, >80 G, >30 G 0 nc nc G >500 G++ <30 VG Av. nc 26 VG, >80 G, >30 G 0 nc nc Av. >250 VG <10 VG G+ nc 27 VG, >80 G, >30 VG 0 5 50  VG >1000 G+ 35 P G nc 28 VG, >80 G, >30 G+ 0 0 50  G >500 G+ 37 VP G nc 29 VG, >80 G, >30 G+ 0 30  70  VG >1000 G+ 41 P G nc 30 VG, >80 G, >30 VG 0 0 0 VG >1000 G 59 P G+ nc 31 G, >60 G, >30 G 0 nc nc VG >1000 Av. 110 Av. nc nc 32 G, >60 G, >30 G 0 nc nc VG >1000 Av. 116 VG nc nc 33 VG, >80 G, >30 G+ 0 0 3 Av. >250 VG <10 VG G nc 34 VG, >80 G, >30 G 0 0 90  Av. >250 VG <10 VG G nc 35 VG, >80 G, >30 VG 0 0 0 G >500 VG <10 VG G nc 36 VG, >80 G, >30 VG 0 0 0 Av. >250 VG <10 VG G+ no 37 VG, >80 G, >30 G 0 nc nc Av. >250 VG <10 Nc nc yes 38 VG, >80 G, >30 G+ 0 0 nc Av. >250 VG <10 Nc nc yes 39 Av., >30 Av., >25 G 0 nc nc Av. >250 G++ <20 Nc nc nc 40 Av., >30 Av., >25 G 0 nc nc Av. >250 G++ <20 Nc nc nc 41 Av., >30 Av., >25 G 0 nc nc nc G++ <20 VG nc nc 42 Av., >30 Av., >25 G 0 nc nc nc G++ <20 VG nc nc 43 Av., >30 Av., >25 G 0 nc nc nc G++ <20 VG nc nc 44 G, >60 G, >30 nc nc nc nc nc G+ 31 P nc nc 45 G, >60 G, >30 nc nc nc nc nc G++ <30 Av. nc nc 46 VG, >80 G, >30 nc nc nc nc nc G+ 31 Av. nc nc 47 G, >60 G, >30 nc nc nc nc nc G+ 39 Av. nc nc 48 VG, >80 G, >30 nc nc nc nc nc VG <10 Av. nc nc 49 Av., >30 G, >30 nc nc nc nc nc G++ <20 VG Nc nc 50 G, >60 G, >30 nc nc nc nc nc G++ <30 Av. Nc nc 51 G, >60 G, >30 G 0 Nc nc Nc Nc nc VP VG Nc 52 G, >60 G, >30 G 0 Nc nc Nc Av. 190 VP G+ nc 53 G, >60 G, >30 G 0 Nc nc Av. >250 G++ <30 Av. Av. Nc 54 G, >60 G, >30 G 0 Nc nc Nc VG <20 Nc Av. Nc 55 G, >60 G, >30 G 0 Nc nc Nc VG <10 VP G Nc 56 G, >60 G, >30 G 0 Nc nc Nc VG <10 VP G+ Nc 57 G, >60 G, >30 G 0 Nc nc Nc VG <10 VP G Nc 58 G, >60 G, >30 G+ 0 0 nc Nc VG <10 VG G+ Nc 59 G, >60 G, >30 G+ 0 0 nc Nc VG <10 VG G+ Nc 60 G, >60 G, >30 G+ 0 0 nc Av. >250 VG <10 VG G+ Nc 61 G, >60 G, >30 G+ 0 Nc nc Nc VG+ <3 VG G+ Nc 62 G, >60 G, >30 G+ 0 0 nc Nc G++ <30 VG G Nc 63 G, >60 G, >30 G 0 nc nc Nc VG+ <3 Av. Av. Nc 64 Av., >30 G, >30 G+ 0 0 nc Nc VG+ <3 TN Av. Nc 65 Av., >30 G, >30 G+ 0 0 nc Nc VG+ <3 VG Av. Nc 66 Av., >30 G, >30 G 0 Nc nc Av. >250 G++ <30 Av. Av. Nc 67 G, >60 G, >30 G 0 nc nc Nc G++ <30 Av. Av. Nc 68 G, >60 G, >30 G 0 nc nc Nc G++ <30 VP Av. Nc 69 G, >60 G, >30 VG 0 0 nc Nc Av. 215 VG VG Nc 70 G, >60 G, >30 VG 0 0 0 Nc Av. Nc VG G+ Nc 71 G, >60 G, >30 VG 0 0 0 VG >1000 Av. Nc VG G+ Nc 72 G, >60 G, >30 G 0 nc nc nc VG <10 VG G Nc 73 G, >60 G, >30 G 0 nc nc nc Av. 185 VP G+ Nc 74 G, >60 G, >30 G 0 nc nc nc G++ <30 Av. Av. Nc 75 G, >60 G, >30 G 0 nc nc nc VG <10 VP G Nc 76 G, >60 G, >30 G+ 0 0 nc nc VG <10 VG G+ Nc 77 G, >60 G, >30 G 0 nc nc nc VG <10 VP G+ Nc 78 G, >60 G, >30 G 0 nc nc nc G++ <30 VP Av. Nc 79 G, >60 G, >30 G 0 nc nc nc VG+ <3 VG Av. Nc 80 G, >60 G, >30 VG 0 0 nc nc Av. 160 VG G+ Nc 81 G, >60 G, >30 G 0 nc nc nc VG <10 VG G Nc 82 G, >60 G, >30 G 0 nc nc nc G++ <30 Av. Av. Nc 83 G, >60 G, >30 G 0 nc nc nc G++ <30 Av. Av. Nc 84 G, >60 G, >30 G 0 nc nc nc VG <10 VG G Nc 85 G, >60 G, >30 G 0 nc nc Nc G+ <50 Av. G Nc 86 G, >60 G, >30 G 0 nc nc Nc G++ <30 Av. G Nc

(163) TABLE-US-00006 APPENDIX 3 Evaluation of the structures of the counterexamples: 1 2 3 4 5 6 7 8 9 10 11 1 VG, >80 VP, 3 nc nc nc nc nc nc nc nc Nc 2 G, >60 VP, 3 nc nc nc nc nc nc nc nc Nc 3 P, 27 P, 13 nc nc nc nc nc nc nc nc Nc 4 P, 28 P, 16 nc nc nc nc nc nc nc nc Nc 5 Av., 32 P, 19 nc nc nc nc nc nc nc nc Nc 6 P, 23 P, 20 nc nc nc nc nc nc nc nc Nc 7 P, 20 P, 12 nc nc nc nc nc nc nc nc Nc 8 P, 27 P, 15 nc nc nc nc nc nc nc nc Nc 9 Av., 33 P, 16 nc nc nc nc nc nc nc nc Nc 10 P, 12 nc nc nc nc nc nc nc nc nc Nc 11 VP, <5 nc nc nc nc nc nc nc nc nc Nc 12 P, 20 P, 13 nc nc nc nc nc nc nc nc Nc 13 Av., 55 VP, 0 nc nc nc nc nc nc nc nc Nc 14 VP, <5 nc nc nc nc nc nc nc nc nc Nc 15 P, 30 nc nc nc nc nc nc P 220 nc Nc 16 nc nc Nc nc nc nc nc P 235 nc Nc 17 nc nc Nc nc nc nc VP <50 nc nc VP Nc 18 nc nc Nc nc nc nc VP <50 nc nc nc Nc 19 nc nc VP 100  100 100 nc nc nc nc Nc 20 nc nc P 80  100 100 nc nc nc nc Nc 21 VP, <5 nc Nc nc nc nc nc nc nc nc Nc 22 VP, <5 nc Nc nc nc nc nc nc nc nc Nc 23 — — G+ 0  7  53 P <250 P 350 VG VG 24 P >10, <20 VP, <5 G+ 0 100 100 nc nc nc Av. Av. 25 P >10, <20 VP, <5 G+ 0 100 100 nc nc nc Av. Av.

(164) TABLE-US-00007 APPENDIX 4 Examples Appendix 2 No. 33 18 2 5 layers 4 layers 3 layers Extruder 1, internal PA11-TL PA6OYE PA6OY Z1, ° C. 180 200 200 Z2, ° C. 200 220 220 Z3, ° C. 220 240 240 Z4, ° C. 230 240 240 Z5, ° C. 240 240 240 Z6, ° C. 240 240 240 Z7, ° C. 240 240 240 Screw spin speed, rpm 28.3 35 28.3 Torque, % 38 24 28 Pressure, bar 299 142 194 Adhesive Extruder 2 composition 2 EVOH PA6OY Z1, ° C. 170 200 200 Z2, ° C. 190 220 220 Z3, ° C. 210 240 240 Z4, ° C. 240 240 240 Z5, ° C. 240 240 240 Screw spin speed, rpm 17 32.5 30.3 Torque, % 33 28 18 Pressure, bar 73 83 81 Extruder 3 EVOH PA11Cu PA11Cu Z1, ° C. 170 190 200 Z2, ° C. 190 210 220 Z3, ° C. 210 230 240 Z4, ° C. 230 240 250 Z5, ° C. 240 240 250 Z6, ° C. 240 240 250 Z7, ° C. 240 240 250 Screw spin speed, rpm 9.6 28.6 32.3 Torque, % 40 40 32 Pressure, bar 97 281 100 Adhesive Adhesive Adhesive Extruder 4 composition 2 composition 2 composition 2 Z1, ° C. 190 190 200 Z2, ° C. 220 210 220 Z3, ° C. 230 230 240 Z4, ° C. 240 260 250 Z5, ° C. 240 260 270 Screw spin speed, rpm 27 12.4 12.1 Torque, % 7 28 15 Pressure, bar 22 85 84 Extrudeuse 5, externe PA11Cu PA11Cu PA11Cu Z1, ° C. 170 190 200 Z2, ° C. 200 210 220 Z3, ° C. 220 220 240 Z4, ° C. 240 230 250 Z5, ° C. 240 240 250 Z6, ° C. 240 240 250 Z7, ° C. 240 240 250 Screw spin speed, rpm 37.3 38.3 32.8 Torque, % 30 38 28 Pressure, bar 74 287 98 Coextrusion head Temp,, ° C. 240 260 260 Tools Z1, ° C. 240 260 260 Z2, ° C. 240 260 260 Z3, ° C. 230 260 260 Calibration Gauge diameter, mm 9 8.85 9.5 bleed rate, l/h 36 36 44 gauge-die distance, 60 35 30 mm pressure reduction, 100 80 50 mbar Line Line speed, m/min 20 20 20