Extruded compositions comprising recycled polyamides recovered when exploiting offshore or shore oil or gas deposits

Abstract

The present invention relates to an extruded composition comprising, by weight: a) 35 to 100%, in particular 35 to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1 comprising at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, from the production of offshore or shore oil or gas deposits, in particular from the production of oil or gas deposits, in particular from the production of oil or gas deposits, in particular from the production of oil or gas deposits, in particular from the production of oil or gas deposits, in particular from the production of oil or gas deposits, in particular from the production of oil or gas deposits, in particular from the production of oil or gas deposits, in particular from the production of oil or gas deposits. Recovery from used or end-of-life conduits, in particular offshore oil or gas deposits, said recycled semi-crystalline aliphatic polyamide PA2 having been subjected to washing and / or compounding steps when the conduits are removed and ground to form particles; b) 0 to 65%, in particular 0 to 10%, of at least one reinforcing fiber; c) 0 to 40%, in particular 3 to 30%, of at least one impact modifier; the invention relates to a composition comprising a) 0 to 30%, in particular 0 to 15%, of m-cresol, d) 0 to 30%, in particular 0 to 15%, of a filler, e) 0 to 10%, in particular 0.1 to 5%, of at least one additive, the sum of the components a + b + c + d + e being equal to 100%, the intrinsic viscosity of said composition, determined according to ISO 307: 2007 in m-cresol at 20 DEG C, being greater than or equal to 1.2 dl / g, in particular 1.2 dl / g to 1.7 dl / g.

Description

Technical Field

[0001] The present invention relates to an extrusion composition comprising recycled polyamide, said recycled polyamide being derived from the exploitation of offshore or onshore oil or gas deposits. Background Art

[0002] In the exploitation of offshore or onshore oil or gas deposits, flexible pipes are required to connect various devices around the platform. These pipes must withstand hot oil, gas, water, and mixtures of at least two of these products for a period that can last up to 20 years. These pipes generally include an inner unsealed metal layer formed by helically wound profiled metal strips (such as stapled foil) that gives the pipe its shape, then a polymer is extruded onto this layer to provide a seal, and finally other protective and reinforcing layers (such as metal fiber mesh and rubber) are added.

[0003] Long-chain polyamides have been used for many years in the exploitation of offshore and onshore oil and gas deposits.

[0004] However, it is necessary to clean these pipes by circulating methanol therein, for example, to remove hydrates. The drawback of methanol is that it penetrates deeply into the polyamide. Thus, methanol is lost, but plasticizers and / or modifiers can also be extracted from the polyamide by methanol, resulting in the deterioration of the mechanical properties of the pipes and premature aging.

[0005] In addition, due to the fact that they have reached the end of their service life, tens to hundreds of tons of long-chain polyamides from pipes used in the exploitation of offshore or onshore oil and gas deposits will have to be recycled in the coming years. However, these polyamides cannot be used after simple grinding due to the contaminants they contain (derived from the extracted oil or gas).

[0006] The polyamide (PA) derived from pipes used in the exploitation of offshore or onshore oil and gas deposits cannot be used as it is.

[0007] They must be ground in order to be able to be transformed into parts with different shapes for different applications.

[0008] After grinding, the polyamide to be recycled must also be washed and / or compounded in order to extract the vast majority of the contaminants (with solvents, in the melt, under vacuum, etc.). However, the extraction is not necessarily complete.

[0009] In the absence of this washing and / or compounding step, the manufactured parts exhibit exudation. This exudate can be toxic to the user and can give the parts a greasy appearance.

[0010] In addition, the polyamides to be recycled may be hydrolyzed to a large extent and thus not extrudable. In such cases, they must be exposed to a high vacuum (with a catalyst added if necessary) to increase their viscosity and make them extrudable. Summary of the Invention

[0011] Therefore, it must be possible to provide a composition which can first be extruded completely safely for the operator (without releasing toxic gases) and secondly, all types of extruded parts obtained are stable over time (without exudation).

[0012] Therefore, the present invention relates to an extrusion composition which comprises, by weight:

[0013] a) 35% to 100%, in particular 35% to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, said recycled semi-crystalline aliphatic polyamide PA2 being sourced from used or end-of-life pipes used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 having undergone a washing and / or compounding step after removal of the pipes and grinding of the pipes in particulate form;

[0014] b) 0 - 65%, in particular 0 - 10%, of at least one reinforcing fiber;

[0015] c) 0 - 40%, in particular 3% - 30%, of at least one impact modifier;

[0016] d) 0 - 30%, in particular 0 - 15%, of a filler;

[0017] e) 0 - 15%, in particular 0.1% - 10%, in particular 0.5% - 5%, of at least one additive;

[0018] The sum of components a + b + c + d + e is equal to 100%,

[0019] The intrinsic viscosity of the composition measured in m-cresol at 20 °C according to ISO 307:2007 is greater than or equal to 1.2 dl / g, in particular in the range from 1.2 dl / g to 1.7 dl / g.

[0020] Thus, the present inventors have found that adding recycled polyamide PA2 derived from used or end-of-life pipelines used in the exploitation of onshore or offshore oil or gas deposits, especially offshore deposits, to virgin polyamide PA1 results in an extrudable composition that does not release harmful or toxic gases (safe for operators) for the production of all types of extruded parts that do not exude or exhibit low exudation. The composition of the present invention has good mechanical properties, allowing for improved welding quality and productivity between two parts.

[0021] The exploitation of offshore or onshore oil or gas deposits uses flexible pipelines to connect the various offshore or onshore installations of a platform respectively and for transporting the extracted hydrocarbons.

[0022] These pipelines must withstand hot oil, gas, water, and mixtures of at least two of these products for a period that can last up to 20 years.

[0023] The term "used" means that the pipeline has been used in the exploitation of an oil or gas deposit, whether offshore or onshore, but has not reached its operating limit of up to 20 years. When the platform stops production and is dismantled, this type of pipeline that has not reached the end of its service life needs to be recycled.

[0024] The term "end-of-life" means that the pipeline has been used in the exploitation of an oil or gas deposit, whether offshore or onshore, but has reached its operating limit of up to 20 years. Therefore, these pipelines must be removed from the operating system before they are completely deteriorated or before they have sealing problems with respect to the oil or gas being transported.

[0025] Regarding semi-crystalline aliphatic polyamide PA1

[0026] The polyamide PA1 can be a homopolyamide or a copolyamide or a mixture thereof.

[0027] The term "semi-crystalline aliphatic polyamide" refers to a material that is usually solid at room temperature and softens during temperature increase, especially after passing through its glass transition temperature (Tg), and melts sharply when passing through its "melting temperature" (Tm), and becomes solid again when the temperature drops below its crystallization temperature.

[0028] Tg, Tc, and Tm are determined by differential scanning calorimetry (DSC) according to standards 11357-2:2013 and 11357-3:2013 respectively.

[0029] The number average molecular weight Mn of the semi-crystalline polyamide preferably extends in the range from 10,000 to 85,000, notably from 10,000 to 60,000, preferably from 10,000 to 50,000, and even more preferably from 12,000 to 50,000.

[0030] The nomenclature used to define polyamides is described in the standard ISO 1874-1:2011 "Plastics - Polyamide (PA) molding and extrusion materials - Part 1: Designation", in particular on page 3 (Tables 1 and 2), and is well known to those skilled in the art.

[0031] Said at least one semi-crystalline aliphatic polyamide PA1 can be obtained from the polycondensation of at least one lactam, or from the polycondensation of at least one amino acid, or from the polycondensation of at least one diamine X and at least one dicarboxylic acid Y or a mixture thereof.

[0032] When said at least one aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of at least one lactam, said at least one lactam can be selected from C6 to C18, C8 to C18, preferably C10 to C18, more preferably C10 to C12 lactams. C6 to C18 lactams are notably caprolactam, laurolactam, undecalactam or dodecalactam.

[0033] When said at least one aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of at least one lactam, it can thus contain a single lactam or several lactams.

[0034] Advantageously, said at least one aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of a single lactam, and said lactam is selected from laurolactam and undecalactam, advantageously laurolactam.

[0035] When said at least one aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of at least one amino acid, said at least one amino acid can be selected from C8 to C18, preferably C10 to C18, more preferably C10 to C12 amino acids.

[0036] C8 to C18 amino acids are especially 9-aminononanoic acid, 10-aminodecanoic acid, 10-aminoundecanoic acid, 12-aminododecanoic acid and 11-aminoundecanoic acid and their derivatives, especially N-heptyl-11-aminoundecanoic acid.

[0037] When said at least one aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of at least one amino acid, it can thus contain a single amino acid or several amino acids.

[0038] Advantageously, said aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of a single amino acid, and said amino acid is selected from 10-aminodecanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, advantageously 11-aminoundecanoic acid.

[0039] When the at least one semi-crystalline aliphatic polyamide PA1 is obtained from the polycondensation of at least one diamine X and at least one aliphatic dicarboxylic acid Y, the diamine X is C4-C36, preferably C6-C18, preferably C6-C12, more preferably C10-C12, and the aliphatic dicarboxylic acid Y is C6-C36, preferably C6-C18, preferably C6-C12, more preferably C10-C12.

[0040] The diamine can be straight-chain or branched-chain. Advantageously, it is straight-chain.

[0041] The at least one C4-C36 diamine X can in particular be selected from 1,4-butanediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine, 1,18-octadecamethylenediamine, octadecenediamine, eicosanediamine, docosanediamine, and diamines obtained from fatty acids.

[0042] Advantageously, the at least one diamine X is C4-C18 and is selected from 1,4-butanediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine, and 1,18-octadecamethylenediamine.

[0043] Advantageously, the at least one C6 to C12 diamine X is in particular selected from 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, and 1,12-dodecamethylenediamine.

[0044] Advantageously, the at least one C6 to C12 diamine X is in particular selected from 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, and 1,12-dodecamethylenediamine.

[0045] Advantageously, the diamine X used is a C10 to C12 diamine, in particular selected from 1,10-decamethylenediamine, 1,11-undecamethylenediamine, and 1,12-dodecamethylenediamine.

[0046] Said at least one C6-C36 dicarboxylic acid Y may be selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and dicarboxylic acids obtained from fatty acids.

[0047] The dicarboxylic acid may be straight-chain or branched-chain. Advantageously, it is straight-chain.

[0048] Advantageously, said at least one dicarboxylic acid Y is a C6-C18 dicarboxylic acid and is selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, and octadecanedioic acid.

[0049] Advantageously, said at least one dicarboxylic acid Y is a C6-C12 dicarboxylic acid and is selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid.

[0050] Advantageously, said at least one dicarboxylic acid Y is a C10-C12 dicarboxylic acid and is selected from sebacic acid, undecanedioic acid, and dodecanedioic acid.

[0051] When said aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of at least one diamine X and at least one dicarboxylic acid Y, it may contain a single diamine or several diamines and a single dicarboxylic acid or several dicarboxylic acids.

[0052] Advantageously, said aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of a single diamine X and a single dicarboxylic acid Y.

[0053] In one embodiment, the recycled semi-crystalline aliphatic polyamide PA1 is a long-chain polyamide having an average number of carbon atoms per nitrogen atom greater than 7, particularly greater than 9.

[0054] Regarding the recycled semi-crystalline aliphatic polyamide PA2

[0055] The polyamide PA2 may be a homopolyamide, a copolyamide, or a mixture thereof.

[0056] The term "semi-crystalline aliphatic polyamide" refers to a material that is generally solid at room temperature and softens during temperature increase, particularly after passing through its glass transition temperature (Tg), and melts sharply when passing through its "melting temperature" (Tm), and becomes solid again when the temperature is lowered below its crystallization temperature.

[0057] Tg, Tc, and Tm are determined by differential scanning calorimetry (DSC) in accordance with standards 11357-2:2013 and 11357-3:2013, respectively.

[0058] The number-average molecular weight Mn of the semi-crystalline polyamide is preferably in the range extending from 10,000 to 85,000, notably from 10,000 to 60,000, preferably from 10,000 to 50,000, and even more preferably from 12,000 to 50,000.

[0059] Said at least one semi-crystalline aliphatic polyamide PA2 is initially obtained by polycondensation of at least one lactam, or by polycondensation of at least one amino acid, or by polycondensation of at least one diamine X and at least one dicarboxylic acid Y or a mixture thereof, as described above for semi-crystalline aliphatic polyamide PA1, before being used for the exploitation of oil or gas deposits.

[0060] Advantageously, PA 2 is PA 11 or PA 12, especially PA11.

[0061] After use, i.e., when it is exhausted or at the end of its life, the pipeline used for the exploitation of offshore or onshore oil or gas deposits, especially offshore deposits, is removed from the drilling platform, the individual layers are separated, and the layer containing PA 2 is ground in the form of a grinding material (0.5 mm to 25 mm) or powder (to a size of less than 0.5 mm), then washed and / or compounded, i.e., after washing or without washing, the fragments are placed in an extruder at least once, especially an extruder of the co-rotating twin-screw or co-kneader (Buss) type, where the fragments are remixed by melting, with or without the addition of at least one catalyst. The molten material exits the extruder as a rod, and the rod is cooled and cut into pellets.

[0062] Advantageously, the number of compounding operations is from 1 to 10, especially from 1 to 5; the number of compounding operations is notably 1, 2, 3, 4 or 5, especially 1, 2 or 3.

[0063] If necessary, solvents, especially methanol or ethanol, can be used to wash the fragments in order to extract the vast majority of the contaminants from the exploitation, as described below.

[0064] If necessary, compounding can be carried out in the presence of a catalyst.

[0065] The term "catalyst" denotes a polycondensation catalyst, such as an inorganic or organic acid.

[0066] Advantageously, the weight ratio of the catalyst is from about 50 ppm to about 5000 ppm, especially from about 100 to about 3000 ppm, relative to the total weight of the composition.

[0067] Advantageously, the catalyst is selected from phosphoric acid (H3PO4), phosphorous acid (H3PO3) and hypophosphorous acid (H3PO2) or a mixture thereof.

[0068] Advantageously, the present invention thus relates to the use of at least one catalyst as defined above, at least one copper-based heat stabilizer and at least one oligocarbonimide or polycarbonimide with a matrix comprising at least one thermoplastic polymer, in particular polyamide, wherein, relative to the total weight of the composition, the weight ratio of the catalyst is from about 50 ppm to about 5000 ppm, in particular from about 100 to about 3000 ppm, and the catalyst is selected from phosphoric acid (H3PO4), phosphorous acid (H3PO3), hypophosphorous acid (H3PO2) or mixtures thereof.

[0069] Advantageously, the catalyst is selected from phosphoric acid (H3PO4), phosphorous acid (H3PO3), in a proportion of from about 100 to about 3000 ppm.

[0070] In one embodiment, the PA2 mixture to be recycled is degassed during compounding.

[0071] In one embodiment, the degassing is weak, meaning that the degassing range is from -50 mmHg to -150 mmHg.

[0072] For example, it is carried out according to the following Scheme A:

[0073] The washed or unwashed ground tubing is compounded on a Coperion / Werner 40 mm twin-screw extruder, 70 kg / h, 300 rpm, 270 °C set point, with degassing at about 100 mmHg.

[0074] In another embodiment, the degassing is strong, meaning that the degassing range is from -550 mmHg to -750 mmHg.

[0075] For example, it is carried out according to the following Scheme B:

[0076] The washed or unwashed ground tubing is compounded on a Coperion / Werner 40 mm twin-screw extruder, 70 kg / h, 300 rpm, 270 °C set point, with strong degassing at -660 mmHg.

[0077] Advantageously, the degassing is carried out just after the melting zone in the extruder.

[0078] As determined in m-cresol at 20 °C according to ISO 307:2007, after grinding and washing or after grinding and compounding (with or without catalyst), or after grinding, washing and compounding (with or without catalyst), the intrinsic viscosity of the semi-crystalline aliphatic polyamide is greater than or equal to 1.2 dl / g, in particular in the range from 1.2 dl / g to 1.7 dl / g.

[0079] The ground, washed and / or compounded semi-crystalline aliphatic polyamide, with or without a catalyst and with or without degassing, thus corresponds to the recycled semi-crystalline aliphatic polyamide PA2 of the composition according to the invention.

[0080] In one embodiment, the recycled semi-crystalline aliphatic polyamide PA2 is a long-chain polyamide having an average number of carbon atoms per nitrogen atom greater than 7, in particular greater than 9.

[0081] In particular, the recycled semi-crystalline aliphatic polyamide PA2 is a long-chain polyamide having an average number of carbon atoms per nitrogen atom greater than 7 to 12, notably greater than 7 to 11, in particular greater than 9 to 12, notably greater than 9 to 11.

[0082] In another embodiment, the recycled semi-crystalline aliphatic polyamide PA2 contains at least one substance selected from alkanes, aliphatic C14-C18 monocarboxylic acids, monoaromatic or polyaromatic compounds and aromatic acids.

[0083] The alkanes are notably methylcyclopentane, cyclohexane, methylcyclohexane, 1,2-cis-dimethylcyclohexane, 1,2-trans-dimethylcyclohexane, 1,3-cis-dimethylcyclohexane, 1,3-trans-dimethylcyclohexane, 1,4-cis-dimethylcyclohexane, 1,4-trans-dimethylcyclohexane or ethylcyclohexane.

[0084] The C14 to C18 aliphatic monocarboxylic acids are notably palmitic acid and stearic acid.

[0085] The C14-C18 aliphatic monocarboxylic acids are also present in the initial virgin semi-crystalline aliphatic polyamide (1-100 ppm), but are present in the recycled semi-crystalline aliphatic polyamide PA2 at a higher concentration (greater than 100 ppm), in particular 500-5000 ppm.

[0086] The monoaromatic or polyaromatic compounds are notably toluene, xylene, trimethylbenzene, diphenylmethane, diphenylmethanol, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1,2-dimethylnaphthalene, 1,3-dimethylnaphthalene, 1,4-dimethylnaphthalene, 1,3,6-trimethylnaphthalene, 2,3,5-trimethylnaphthalene, 1-phenanthrene and 2-methylphenanthrene.

[0087] The aromatic acids are notably benzoic acid, 2-methylbenzoic acid, 3-methylbenzoic acid, 4-methylbenzoic acid, 2,5-dimethylbenzoic acid, 3,4-dimethylbenzoic acid, 2,4-dimethylbenzoic acid and 3,5-dimethylbenzoic acid.

[0088] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from sulfur compounds, alkanes, C14-C18 aliphatic monocarboxylic acids, monoaromatic or polyaromatic compounds, and aromatic acids.

[0089] More advantageously, the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from alkanes, monoaromatic or polyaromatic compounds, and aromatic acids.

[0090] Even more advantageously, the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from alkanes and monoaromatic or polyaromatic compounds.

[0091] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from alkanes such as methylcyclopentane, cyclohexane, methylcyclohexane, 1,2-cis-dimethylcyclohexane, 1,2-trans-dimethylcyclohexane, 1,3-cis-dimethylcyclohexane, 1,3-trans-dimethylcyclohexane, 1,4-cis-dimethylcyclohexane, 1,4-trans-dimethylcyclohexane, or ethylcyclohexane, and monoaromatic or polyaromatic compounds such as toluene, xylene, trimethylbenzene, diphenylmethane, diphenylmethanol, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1,2-dimethylnaphthalene, 1,3-dimethylnaphthalene, 1,4-dimethylnaphthalene, 1,3,6-trimethylnaphthalene, 2,3,5-trimethylnaphthalene, 1-phenanthrene, and 2-methylphenanthrene.

[0092] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from bitumen in a content of 0.1 - 500 ppm.

[0093] In one embodiment, the total mass content of the substances present in the recycled semi-crystalline aliphatic polyamide PA2 is 1 ppm - 2000 ppm, such as 10 ppm - 2000 ppm, such as 50 ppm - 2000 ppm, such as 100 ppm - 2000 ppm, especially 100 ppm - 1000 ppm, such as 100 ppm - 700 ppm, such as 100 ppm - 400 ppm. Preferably, the total mass content range of the substances present in the recycled semi-crystalline aliphatic polyamide PA2 is from 10 ppm to 700 ppm, such as from 50 ppm to 400 ppm.

[0094] In one embodiment, the mass content of each alkane in the recycled semi-crystalline aliphatic polyamide PA2 is 0.1 - 400 ppm, preferably 1 - 150 ppm.

[0095] In one embodiment, the mass content of each aromatic compound in the recycled semi-crystalline aliphatic polyamide PA2 ranges from 0.1 to 600 ppm, preferably from 1 to 300 ppm, particularly from 5 to 100 ppm.

[0096] Alkanes and aromatic molecules are analyzed by pyrolysis desorption (dynamic headspace at 300 °C for 60 minutes) coupled with gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact (EI) source. Quantification is carried out in pentadecane equivalents.

[0097] In one embodiment, the mass content of each acidic aromatic compound in the recycled semi-crystalline aliphatic polyamide PA2 is from 0.1 to 600 ppm, preferably from 1 to 300 ppm, particularly from 5 to 100 ppm.

[0098] In one embodiment, the mass content of each monoacid compound in the recycled semi-crystalline aliphatic polyamide PA2 ranges from 0.1 to 600 ppm, preferably from 1 to 300 ppm, particularly from 5 to 100 ppm.

[0099] For the quantification of acidic aromatic compounds or monoacids, methanol extraction is required, followed by methylation derivatization of the dry extract to enhance detection. Analysis is carried out by gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact source. Quantification is carried out in pentadecane equivalents.

[0100] In another embodiment, the recycled semi-crystalline aliphatic polyamide PA2 has a characteristic odor comprising sulfur / pyrogen and / or hydrocarbons and / or aromatic compounds, terpene and phenolic atmospheres.

[0101] The above-mentioned odor is determined according to the description of Odor Field® by Jean-Noél Jaubert.

[0102] The odor field developed in 1983 in particular provides a method that enables olfactory perception to be described in a common way, i.e., by assigning separate evocations as much as possible. It was created by the researcher Jean-Noél Jaubert as a result of a research program on the chemical structure / odor activity relationships of the molecules present in the world of odors. Initially developed for the perfume industry, this method has made it possible to describe, analyze, compare and control complete products or odoriferous preparations beyond the usual classifications.

[0103] The drawbacks associated with the odor problem are characteristic of recycled polyamides.

[0104] This drawback can be perceived when opening the container of the washed or unwashed chips, or during extrusion and possibly for the finished product.

[0105] The recycled polyamide has an odor atmosphere of sulfur or aromatic compounds (aromatic solvent odor, naphthalene). The difference between the original polyamide and the recycled polyamide can clearly be smelled.

[0106] In yet another embodiment, the recycled semi-crystalline aliphatic polyamide PA2 contains functional groups generated by a pyrolysis reaction in an acidic medium, in particular amide functional groups and / or methylene groups at the α-position of the amide functional groups and acid chain ends, which are selected from nitrile functional groups, ketone functional groups, and ester functional groups generated by the reaction of the acid functional groups of the polyamide with an alcohol used during the lifetime of the pipe, and the molar ratio thereof with respect to the amide functional groups is greater than that of the same polyamide constituting the unused pipe.

[0107] In one embodiment, the molar ratio of the functional groups derived from the pyrolysis reaction is from 1 / 10000 to 1 / 20, as determined by proton NMR.

[0108] The concentration can be measured by proton NMR in dichloromethane-d2, where HFIP (hexafluoroisopropanol) is added to dissolve the polyamide.

[0109] During oil extraction, an alcohol such as ethanol is used, which can react with the acid functional groups initially present in the semi-crystalline aliphatic polyamide to form ester functional groups.

[0110] In one embodiment, the content of cyclic oligomers in the recycled semi-crystalline aliphatic polyamide PA2 is lower than that of the equivalent virgin polyamide, and the cyclic oligomers are selected from oligomers having a molar mass of less than 1000 g / mol.

[0111] The content of cyclic oligomers is measured according to the following protocol:

[0112] The recycled semi-crystalline aliphatic polyamide PA2 particles are dissolved in a mixture of HFIP (CAS RN 920-66-1) / CH2Cl2 (CAS RN 75-09-3), and then a non-solvent (methanol CAS RN 67-56-1) is added. Thus, low molar mass substances dissolve and high molar mass substances precipitate.

[0113] Before analysis, the solution is filtered at 200 μm.

[0114] The oligomers are evaluated as lactam-12 equivalents by reversed-phase liquid chromatography-mass spectrometry using positive electrospray ionization. Formic acid is added to improve ionization.

[0115] Due to the different molar masses (from monomers to pentamers in linear or cyclic form), a peak distribution is observed.

[0116] As a result of first fluid transporting and then washing, the polyamide has fewer oligomers than the same original semi-crystalline aliphatic polyamide, because the transporting and washing extract cyclic oligomers.

[0117] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 has a content of cyclic oligomers of less than 90% by weight, in particular less than 50% by weight, in particular less than 20% by weight, in particular less than 10% by weight, relative to the content of the equivalent original polyamide, and the cyclic oligomers are selected from oligomers having a molar mass of less than 1000 g / mol.

[0118] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 has a higher content of linear oligomers than the original PA.

[0119] For each cyclic substance from monomer to pentamer (preferably having a mass of less than 1000 g.mol -1 ), the weight content of cyclic oligomers in the original polyamide is 500 to 10,000 ppm, and the cyclic dimer is particularly the main substance.

[0120] In particular, in the original polyamide, the content of cyclic oligomers having a mass of less than 1000 g.mol -1 is at most 4% by weight.

[0121] In one embodiment, for each cyclic substance from monomer to pentamer, the recycled semi-crystalline aliphatic polyamide PA2 has a content of cyclic oligomers with a molar mass of less than 1000 g / mol in the range of 50 - 5000 ppm, but in any case lower than that of the equivalent original polyamide.

[0122] For each linear substance from monomer to pentamer (preferably having a mass of less than 1000 g.mol -1 ), the weight content of linear oligomers in the original polyamide is 200 - 2000 ppm.

[0123] In one embodiment, for each cyclic substance from monomer to pentamer, the recycled semi-crystalline aliphatic polyamide PA2 has a content of linear oligomers with a molar mass of less than 1000 g / mol in the range of 250 - 5000 ppm, but in any case greater than that of the equivalent original polyamide.

[0124] In one embodiment, the weight content of the alkyl chain ends of the recycled semi-crystalline aliphatic polyamide PA2 is 1 ppm - 5000 ppm, advantageously 10 - 2500 ppm, the alkyl is C1 - C18, and the content is higher than that of the original semi-crystalline aliphatic polyamide.

[0125] Regarding the composition

[0126] In a first variant, the extruded composition according to the invention comprises by weight:

[0127] a) 35% to 100%, in particular 35% to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, said recycled semi-crystalline aliphatic polyamide PA2 being sourced from used or end-of-life pipelines used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 undergoing a washing and / or compounding step after removal of the pipeline and grinding of the pipeline into granules;

[0128] b) 0 to 65%, in particular 0 to 10%, of at least one reinforcing fiber;

[0129] c) 0 to 40%, in particular 3% to 30%, of at least one impact modifier;

[0130] d) 0 to 30%, in particular 0 to 15%, of a filler;

[0131] e) 0 to 10%, in particular 0.1% to 5%, of at least one additive;

[0132] The sum of components a + b + c + d + e is equal to 100%.

[0133] The composition is an extruded composition and not an injection composition, i.e. it is not a molding composition.

[0134] In an embodiment of this first variant, the extruded composition according to the invention comprises by weight:

[0135] a) 35% to 97%, in particular 35% to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, said recycled semi-crystalline aliphatic polyamide PA2 being sourced from used or end-of-life pipelines used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 undergoing a washing and / or compounding step after removal of the pipeline and grinding of the pipeline into granules;

[0136] b) 0 to 65%, in particular 0 to 10%, of at least one reinforcing fiber;

[0137] c) 3% to 30% of at least one impact modifier;

[0138] d) 0 to 30%, in particular 0 to 15%, of a filler;

[0139] e) 0 to 10%, in particular 0.1% to 5%, of at least one additive;

[0140] The sum of components a + b + c + d + e is equal to 100%.

[0141] In another embodiment of this first variant, the extruded composition according to the invention comprises, by weight:

[0142] a) 35% to 96.9% of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, said recycled semi-crystalline aliphatic polyamide PA2 being sourced from used or end-of-life pipes used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 having undergone a washing and / or compounding step after the pipes have been removed and shredded into pellets;

[0143] b) 0 to 65%, in particular 0 to 10%, of at least one reinforcing fibre;

[0144] c) 3% to 30% of at least one impact modifier;

[0145] d) 0 to 30%, in particular 0 to 15%, of a filler;

[0146] e) 0.1% to 5% of at least one additive,

[0147] The sum of components a + b + c + d + e is equal to 100%.

[0148] Advantageously, in this first variant and its two embodiments, the composition consists of said components.

[0149] In a second variant, the extruded composition comprises, by weight:

[0150] a) 35% to 100%, in particular 35% to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, said recycled semi-crystalline aliphatic polyamide PA2 being sourced from used or end-of-life pipes used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 having undergone a washing and / or compounding step after removing the pipes and shredding the pipes into pellets;

[0151] c) 0 to 40%, in particular 3% to 30%, of at least one impact modifier;

[0152] d) 0 to 30%, in particular 0 to 15%, of a filler;

[0153] e) 0 to 10%, in particular 0.1% to 5%, of at least one additive;

[0154] The sum of components a + c + d + e is equal to 100%.

[0155] In one embodiment of this second variant, the reinforcing fibers are excluded from the extrusion composition according to the invention.

[0156] In one embodiment of this second variant, the extrusion composition according to the invention comprises, by weight:

[0157] a) 35% to 97% of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, said recycled semi-crystalline aliphatic polyamide PA2 being sourced from used or end-of-life pipelines used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 having undergone a washing and / or compounding step after the pipeline has been removed and shredded into pellets;

[0158] c) 3% to 30% of at least one impact modifier;

[0159] d) 0 to 30%, in particular 0 to 15%, of a filler;

[0160] e) 0 to 10%, in particular 0.1% to 5%, of at least one additive;

[0161] The sum of components a + b + c + d + e is equal to 100%.

[0162] In another embodiment of this second variant, the extrusion composition according to the invention comprises, by weight:

[0163] a) 35% to 96.9% of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, said recycled semi-crystalline aliphatic polyamide PA2 being sourced from used or end-of-life pipelines used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 having undergone a washing and / or compounding step after the pipeline has been removed and shredded into pellets;

[0164] c) 3% to 30% of at least one impact modifier;

[0165] d) 0 to 30%, in particular 0 to 15%, of a filler;

[0166] e) at least one additive from 0.1% to 5%,

[0167] The sum of components a + b + c + d + e equals 100%.

[0168] Advantageously, in this second variant and its two embodiments, the composition consists of the said ingredients.

[0169] In one embodiment of these two variants and the related embodiments, the extrusion composition defined above has a characteristic odor comprising sulfur and / or hydrocarbons and / or an aromatic atmosphere as described in Jean-Noel Jaubert's odor field®.

[0170] In one embodiment of these two variants and the related combination, the semi-crystalline aliphatic polyamide PA1 comprises at least 40% of the recycled semi-crystalline aliphatic polyamide PA2 from used or end-of-life pipes that have been used in the exploitation of offshore or onshore oil or gas deposits, especially offshore deposits.

[0171] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 50% of the recycled semi-crystalline aliphatic polyamide PA2.

[0172] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 60% of the recycled semi-crystalline aliphatic polyamide PA2.

[0173] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 70% of the recycled semi-crystalline aliphatic polyamide PA2.

[0174] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 80% of the recycled semi-crystalline aliphatic polyamide PA2.

[0175] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 90% of the recycled semi-crystalline aliphatic polyamide PA2.

[0176] In these last six embodiments, the semi-crystalline aliphatic polyamide PA1 is constituted by the semi-crystalline aliphatic polyamide PA2 in said proportion.

[0177] According to any one of the embodiments of the present invention, the extrusion composition of the present invention may comprise at least one substance selected from alkanes, aliphatic C14-C18 monocarboxylic acids, monoaromatic or polyaromatic compounds, and aromatic acids.

[0178] The alkanes are notably methylcyclopentane, cyclohexane, methylcyclohexane, 1,2-cis-dimethylcyclohexane, 1,2-trans-dimethylcyclohexane, 1,3-cis-dimethylcyclohexane, 1,3-trans-dimethylcyclohexane, 1,4-cis-dimethylcyclohexane, 1,4-trans-dimethylcyclohexane or ethylcyclohexane.

[0179] The C14 to C18 aliphatic monocarboxylic acids are notably palmitic acid and stearic acid.

[0180] The monoaromatic or polyaromatic compounds are notably toluene, xylene, trimethylbenzene, diphenylmethane, diphenylmethanol, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1,2-dimethylnaphthalene, 1,3-dimethylnaphthalene, 1,4-dimethylnaphthalene, 1,3,6-trimethylnaphthalene, 2,3,5-trimethylnaphthalene, 1-phenanthrene and 2-methylphenanthrene.

[0181] The aromatic acids are notably benzoic acid, 2-methylbenzoic acid, 3-methylbenzoic acid, 4-methylbenzoic acid, 2,5-dimethylbenzoic acid, 3,4-dimethylbenzoic acid, 2,4-dimethylbenzoic acid and 3,5-dimethylbenzoic acid.

[0182] Advantageously, the extrusion composition of the present invention comprises at least one substance selected from sulfur compounds, alkanes, aliphatic C14-C18 monocarboxylic acids, monoaromatic or polyaromatic compounds and aromatic acids.

[0183] More advantageously, the extrusion composition of the present invention comprises at least one substance selected from alkanes, monoaromatic or polyaromatic compounds and aromatic acids.

[0184] Even more advantageously, the extrusion composition of the present invention comprises at least one substance selected from alkanes and monoaromatic or polyaromatic compounds.

[0185] Advantageously, the extrusion composition of the present invention comprises at least one substance selected from the following: alkanes such as methylcyclopentane, cyclohexane, methylcyclohexane, 1,2-cis-dimethylcyclohexane, 1,2-trans-dimethylcyclohexane, 1,3-cis-dimethylcyclohexane, 1,3-trans-dimethylcyclohexane, 1,4-cis-dimethylcyclohexane, 1,4-trans-dimethylcyclohexane or ethylcyclohexane, and monoaromatic or polyaromatic compounds such as toluene, xylene, trimethylbenzene, diphenylmethane, diphenylmethanol, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1,2-dimethylnaphthalene, 1,3-dimethylnaphthalene, 1,4-dimethylnaphthalene, 1,3,6-trimethylnaphthalene, 2,3,5-trimethylnaphthalene, 1-phenanthrene and 2-methylphenanthrene.

[0186] Advantageously, the extrusion composition of the present invention comprises at least one substance selected from bitumen in an amount of 0.1 - 500 ppm.

[0187] In one embodiment, the total mass content of the substances present in the extruded composition of the present invention ranges from 0.1 ppm to 2000 ppm, such as from 1 ppm to 1000 ppm, such as from 10 ppm to 300 ppm, such as from 20 ppm to 250 ppm, especially from 30 ppm to 150 ppm. Preferably, the total mass content of the substances present in the composition of the present invention ranges from 1 ppm to 300 ppm, such as from 100 ppm to 150 ppm.

[0188] In one embodiment, the mass content of each alkane in the extruded composition of the present invention is 0.1 - 400 ppm, preferably 1 - 150 ppm.

[0189] In one embodiment, the mass content of each aromatic compound in the extruded composition of the present invention is 0.1 - 300 ppm, preferably 1 - 150 ppm, especially 5 - 100 ppm.

[0190] Alkanes and aromatic molecules are analyzed by thermal desorption (dynamic headspace at 300 °C for 60 minutes), which is coupled to a gas chromatograph (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact (EI) source. Quantification is carried out in terms of pentadecane equivalents.

[0191] In one embodiment, the mass content of each acidic aromatic compound in the extruded composition of the present invention is 0.1 - 300 ppm, preferably 1 - 150 ppm, especially 5 - 100 ppm.

[0192] In one embodiment, the mass content of each monobasic acid compound in the extruded composition of the present invention is between 0.1 and 600 ppm, preferably between 1 and 300 ppm, notably from 5 to 100 ppm.

[0193] For the quantification of acidic aromatic compounds or monobasic acids, methanol extraction is required, followed by methylation derivatization of the dry extract to enhance detection. Analysis is carried out by gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact source. Quantification is carried out in terms of pentadecane equivalents.

[0194] According to any one of the embodiments of the present invention, the content of cyclic oligomers in the extruded composition of the present invention can be lower than that of the equivalent original polyamide, and the cyclic oligomers are selected from oligomers with a molar mass of less than 1000 g / mol.

[0195] The content of cyclic oligomers is measured according to the following protocol:

[0196] The granules of the extrusion composition of the present invention are dissolved in a HFIP (CAS RN 920-66-1) / CH2Cl2 (CAS RN 75-09-3) mixture, and then a non-solvent (methanol CAS RN 67-56-1) is added. Thus, the low molar mass substances dissolve and the high molar mass substances precipitate.

[0197] Before analysis, the solution is filtered at 200 μm.

[0198] The oligomers are evaluated as laurolactam-12 equivalents by reversed-phase liquid chromatography-mass spectrometry using positive electrospray ionization. Formic acid is added to improve ionization.

[0199] Due to the different molar masses (from monomer to pentamer in linear or cyclic form), a peak distribution is observed.

[0200] As a result of first fluid transporting and then washing, the polyamide has fewer oligomers than the same original semi-crystalline aliphatic polyamide because the transporting and washing extract the cyclic oligomers.

[0201] Advantageously, the extrusion composition of the present invention has a content of cyclic oligomers of less than 90% by weight, in particular less than 50% by weight, in particular less than 20% by weight, in particular less than 10% by weight, said cyclic oligomers being selected from oligomers having a molar mass of less than 1000 g / mol, compared to the same extrusion composition comprising an equivalent original polyamide instead of a recycled semi-crystalline aliphatic polyamide PA2.

[0202] Advantageously, the content of linear oligomers in the extrusion composition of the present invention is higher than that of the same extrusion composition comprising an equivalent original polyamide instead of a recycled semi-crystalline aliphatic polyamide PA2.

[0203] For each cyclic substance from monomer to pentamer (preferably having a mass of less than 1000 g.mol -1 ), the weight content of cyclic oligomers in the original polyamide ranges from 500 to 10,000 ppm, and the cyclic dimer is especially the main substance.

[0204] In particular, in the original polyamide, the content of cyclic oligomers having a mass of less than 1000 g.mol -1 is at most 4% by weight.

[0205] In one embodiment, for each cyclic substance from monomer to pentamer, the content of cyclic oligomers having a molar mass of less than 1000 g / mol in the extrusion composition of the present invention is 50 - 5000 ppm, but in any case, it is lower than that of the same extrusion composition comprising an equivalent original polyamide instead of a recycled semi-crystalline aliphatic polyamide PA2.

[0206] For each linear substance from monomer to pentamer (preferably having a mass of less than 1000 g.mol -1 ), the weight content range of linear oligomers in the extrusion composition of the present invention is 200 - 2000 ppm.

[0207] In one embodiment, for each cyclic substance from monomer to pentamer, the extrusion composition of the present invention has a content range of linear oligomers with a molar mass of less than 1000 g / mol of 250 - 5000 ppm, but in any case, it is higher than the content of the same extrusion composition containing an equivalent virgin polyamide rather than a recycled semi-crystalline aliphatic polyamide PA2.

[0208] In one embodiment, the extrusion composition of the present invention contains an alkyl chain end weight content range of 1 ppm - 5000 ppm, advantageously 10 - 2500 ppm, wherein the alkyl is C1 - C18, and the content is higher than the content of the same extrusion composition containing an equivalent virgin polyamide rather than a recycled semi-crystalline aliphatic polyamide PA2.

[0209] Regarding the reinforcing fiber (b)

[0210] Regarding the reinforcing fiber, these are short fibers, which are notably fibers of mineral, organic or plant origin.

[0211] The reinforcing fiber may or may not be sized.

[0212] Thus, the reinforcing fiber may contain up to 0.1 wt% of a material of organic nature (thermosetting or thermoplastic resin type) called sizing.

[0213] Among the fibers of mineral origin, mention may be made, for example, of carbon fibers, glass fibers, basalt fibers or basalt-based fibers, silica fibers or silicon carbide fibers. Among the fibers of organic origin, mention may be made of fibers based on thermoplastic or thermosetting polymers, such as semi-aromatic polyamide fibers, aromatic polyamide fibers or polyolefin fibers. Preferably, they are based on amorphous thermoplastic polymers, and when the polymer or blend is amorphous, its glass transition temperature Tg is greater than the Tg of the thermoplastic polymer or polymer blend constituting the prepreg matrix, or when the polymer or blend is semi-crystalline, its glass transition temperature Tg is greater than the Tm of the thermoplastic polymer or polymer blend constituting the prepreg matrix. Among the fibers of plant origin, mention may be made of natural fibers based on flax, hemp, lignin, bamboo, silk (especially spider silk), sisal and other cellulose fibers (especially viscose fibers). For the purpose of promoting the adhesion and impregnation of the thermoplastic polymer matrix, these plant-origin fibers can be used in pure state, treated or coated with a coating.

[0214] Preferably, the reinforcing fibers are selected from glass fibers, carbon fibers, basalt fibers, and basalt-based fibers.

[0215] More preferably, the reinforcing fibers are selected from carbon fibers and glass fibers.

[0216] In one embodiment, the reinforcing fibers present in a) are glass fibers.

[0217] The glass fibers may have a circular or non-circular cross-section.

[0218] Fibers with a circular cross-section are defined as fibers that have an equal distance from the center of the fiber at any point on its circumference, thus representing a perfect or nearly perfect circle.

[0219] Therefore, any glass fiber that does not have such a perfect or nearly perfect circle is defined as a fiber with a non-circular cross-section.

[0220] Examples of fibers with a non-circular cross-section are, but not limited to, non-circular fibers such as elliptical, oval, or cocoon-shaped, star-shaped fibers, flake-shaped fibers, fibers with a flat shape, cross-shaped, polygonal, and annular.

[0221] The glass fibers may be:

[0222] - a circular cross-section with a diameter of 4 μm to 25 μm, preferably 4 μm to 15 μm;

[0223] - or a non-circular cross-section with an L / D ratio (where L represents the maximum dimension of the fiber cross-section and D represents the minimum dimension of the fiber cross-section) of 2 to 8, especially 2 to 4. L and D can be measured by scanning electron microscopy (SEM).

[0224] Advantageously, the glass fibers are circular.

[0225] Notably, the glass fibers are of type E, R, S2, or T. Advantageously, the glass fibers are of type E.

[0226] Regarding the impact modifier (c):

[0227] The impact modifier represents 0 to 40%, especially 3% to 30% of at least one impact modifier.

[0228] In one embodiment, it accounts for 5% to 20%.

[0229] For example, the impact modifier is a polyolefin or a thermoplastic elastomer with a modulus < 200 MPa, especially < 100 MPa, measured at 23 °C according to standard ISO 178:2010.

[0230] In one embodiment, the impact modifier is selected from functionalized or non-functionalized polyolefins having a modulus < 200 MPa, particularly < 100 MPa, and mixtures thereof.

[0231] Polyolefin:

[0232] The polyolefin can be functionalized, non-functionalized or a blend thereof.

[0233] For simplicity, the polyolefin has been designated as (B), and the functionalized polyolefin (B1) and non-functionalized polyolefin (B2) are described below.

[0234] The non-functionalized polyolefin (B2) is generally a homopolymer or copolymer of an α-olefin or a diene (e.g., ethylene, propylene, 1-butene, 1-octene or butadiene). Examples that may be mentioned include:

[0235] - Polyethylene homopolymers and copolymers, particularly LDPE, HDPE, LLDPE (linear low density polyethylene), VLDPE (very low density polyethylene) and metallocene polyethylene,

[0236] - Polypropylene homopolymers or copolymers,

[0237] - Ethylene / α-olefins, such as ethylene / propylene copolymers, EPR (abbreviation for ethylene propylene rubber) and ethylene / propylene / diene (EPDM) copolymers,

[0238] - Copolymers of ethylene with at least one product selected from: salts or esters of unsaturated carboxylic acids, such as (meth)acrylic acid alkyl esters (e.g., methyl acrylate), or vinyl esters of saturated carboxylic acids, such as vinyl acetate (EVA), and the proportion of comonomer may be up to 40% by weight.

[0239] The functionalized polyolefin (B1) can be a polymer of an α-olefin having reactive units (functional groups); such reactive units are acid, anhydride or epoxy functional groups. By way of example, mention may be made of the aforementioned polyolefin (B2) grafted, copolymerized or terpolymerized with an unsaturated epoxide such as glycidyl (meth)acrylate, or with a carboxylic acid or the corresponding salt or ester such as (meth)acrylic acid (the latter may be completely or partially neutralized with a metal such as Zn, etc.), or with a carboxylic acid anhydride such as maleic anhydride. The functionalized polyolefin is, for example, a PE / EPR mixture, the weight ratio of which can vary within a wide range, for example between 40 / 60 and 90 / 10, and the mixture is co-grafted with an acid anhydride, particularly maleic anhydride, and the grafting degree is, for example, from 0.01% to 5% by weight.

[0240] The functionalized polyolefin (B1) can be selected from the following (co)polymers grafted with maleic anhydride or glycidyl methacrylate, wherein the grafting degree is, for example, from 0.01% to 5% by weight:

[0241] - Polyethylene (PE), polypropylene (PP), copolymers of ethylene with propylene, butene, hexene or octene, containing, for example, from 35% to 80% by weight of ethylene;

[0242] - Ethylene / α-olefin, such as ethylene / propylene copolymer, EPR (abbreviation for ethylene propylene rubber) and ethylene / propylene / diene (EPDM) copolymer;

[0243] - Styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS) and styrene / ethylene-propylene / styrene (SEPS) block copolymers;

[0244] - Copolymer of ethylene and vinyl acetate (EVA), containing up to 40% by weight of vinyl acetate;

[0245] - Copolymer of ethylene and alkyl (meth)acrylate, containing up to 40 wt% of alkyl (meth)acrylate;

[0246] - Copolymer of ethylene and vinyl acetate (EVA) and alkyl (meth)acrylate, containing up to 40% by weight of comonomer.

[0247] The functionalized polyolefin (B1) can also be selected from ethylene / propylene copolymers, mainly propylene, grafted with maleic anhydride and then condensed with monoamino polyamide (or polyamide oligomer) (the product described in EP-A-0342066).

[0248] The functionalized polyolefin (B1) can also be a copolymer or terpolymer of at least the following units: (1) ethylene, (2) alkyl (meth)acrylate or vinyl ester of saturated carboxylic acid and (3) acid anhydride, such as maleic anhydride, or (meth)acrylic acid, or epoxy, such as glycidyl (meth)acrylate.

[0249] As an example of the latter type of functionalized polyolefin, the following copolymers can be mentioned, in which ethylene preferably accounts for at least 60% by weight and the terpolymer (functional group) accounts for, for example, 0.1% to 10% by weight of the copolymer:

[0250] - Ethylene / alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymer;

[0251] - Ethylene / vinyl acetate / maleic anhydride or glycidyl methacrylate copolymer;

[0252] - Ethylene / vinyl acetate or alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymer.

[0253] In the aforementioned copolymer, (meth)acrylic acid can form a salt with Zn or Li.

[0254] In (B1) or (B2), the term “(meth)acrylic acid alkyl ester” means C1-C8 alkyl esters of methacrylic acid and C1-C8 alkyl esters of acrylic acid, and is optionally selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, methyl methacrylate and ethyl methacrylate.

[0255] In addition, the above polyolefin (B1) can also be crosslinked via any suitable method or reagent (diepoxide, diacid, peroxide, etc.); the term “functionalized polyolefin” also includes mixtures of the above polyolefins with bifunctional reagents such as diacids, dianhydrides, diepoxides, etc. that can react with these polyolefins, or mixtures of at least two functionalized polyolefins that can react with each other.

[0256] The above copolymers (B1) and (B2) can be copolymerized in a random or block manner and can have a linear or branched structure.

[0257] The molecular weight, MFI index and density of these polyolefins can also vary within a wide range, as will be understood by those skilled in the art. MFI is the abbreviation for melt flow index. It is measured at 235 °C under 5 kg according to standard ISO 1133.

[0258] Advantageously, the non-functionalized polyolefin (B2) is selected from polypropylene homopolymers or copolymers and any ethylene homopolymer or copolymer of ethylene with comonomers of the higher α-olefin type (such as butene, hexene, octene or 4-methyl-1-pentene). Mention may be made, for example, of PP, high-density PE, medium-density PE, linear low-density PE, low-density PE or very low-density PE. These polyethylenes are known to those skilled in the art and are produced according to the “free radical” method, according to “Ziegler”-type catalysis or more recently according to “metallocene” catalysis.

[0259] The functionalized polyolefin (B1) is advantageously selected from any polymer containing α-olefin units and units with polar reactive functional groups (such as epoxy, carboxylic acid or carboxylic anhydride functional groups). As examples of such polymers, mention may be made of terpolymers of ethylene, acrylic acid alkyl esters and maleic anhydride or glycidyl methacrylate, such as the Lotader® product (SK Functional Polymer), or polyolefins grafted with maleic anhydride, such as the Orevac® product (SK Functional Polymer), and terpolymers of ethylene, acrylic acid alkyl esters and (meth)acrylic acid. Also mention may be made of polypropylene homopolymers or copolymers grafted with carboxylic anhydride and then condensed with monoamino polyamides or monoamino polyamide oligomers.

[0260] In one embodiment, the polyolefin is crosslinked.

[0261] In another embodiment, the polyolefin is a mechanical blend of a thermoplastic olefin polymer with a polyethylene or polypropylene matrix and a vulcanized elastomer, such as a vulcanized PP / EPDM blend.

[0262] The thermoplastic elastomer is a block copolymer (ether-amide block copolymer: PEBA), an ether-ester block copolymer, a thermoplastic polyurethane: TPU, a thermoplastic styrene elastomer).

[0263] Regarding filler (d):

[0264] The filler represents 0 to 30%, particularly 0 to 15% of the filler.

[0265] In one embodiment, the filler accounts for 1% to 5%.

[0266] For example, the filler can be selected from silica, graphite, expanded graphite, carbon black, kaolin, magnesium oxide, slag, talc, wollastonite, nano-fillers (carbon nanotubes), pigments, metal oxides (titanium oxide) and metals, advantageously wollastonite and talc, preferably talc or carbon black.

[0267] Regarding additive (e)

[0268] The additive is optional and accounts for 0 to 10.0 wt%, particularly 0.1 wt% to 5.0 wt%.

[0269] The additive is selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, optical brighteners, antioxidants, lubricants, flame retardants, natural waxes, chain extenders and mixtures thereof.

[0270] Advantageously, the additive is selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, optical brighteners, antioxidants, flame retardants, natural waxes, chain extenders and mixtures thereof.

[0271] More advantageously, the additive is selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, optical brighteners, antioxidants, natural waxes, chain extenders and mixtures thereof.

[0272] For example, the stabilizer may be a UV stabilizer, an organic stabilizer or more generally a combination of organic stabilizers such as phenolic antioxidants (e.g., Irganox® 245 or type 1098 or 1010 from Ciba - BASF), phosphite antioxidants (e.g., Irgafos® 126 from Ciba - BASF) and even optionally other stabilizers such as HALS which refers to hindered amine light stabilizers (e.g., Tinuvin® 770 from Ciba - BASF), UV stabilizers (e.g., Tinuvin® 312 from Ciba) or phosphorus - based stabilizers. Amine antioxidants such as Naugard® 445 from Crompton or multifunctional stabilizers such as Nylostab® S - EED from Clariant may also be used.

[0273] The stabilizer may also be a mineral stabilizer such as a copper - based stabilizer. Examples of such mineral stabilizers that may be mentioned include copper acetate and halides. Incidentally, other metals such as silver may be considered, but these metals are known to be less effective. These copper - based compounds are usually combined with halides of alkali metals (especially potassium).

[0274] For example, the plasticizer is selected from benzenesulfonamide derivatives such as n - butylbenzenesulfonamide (BBSA); ethyltoluene sulfonamide or N - cyclohexyltoluene sulfonamide; esters of hydroxybenzoic acid such as 2 - ethylhexyl p - hydroxybenzoate and 2 - decylhexyl p - hydroxybenzoate; esters or ethers of tetrahydrofurfuryl alcohol such as oligoethyleneoxy tetrahydrofurfuryl alcohol; and esters of citric acid or hydroxy - malonic acid such as oligoethyleneoxy malonate.

[0275] Using a mixture of plasticizers will not constitute a departure from the scope of the invention.

[0276] In one embodiment, the composition according to the invention contains less than 5% and advantageously less than 2% of plasticizer.

[0277] In another embodiment, the composition has an MFI of 0.5 to 25 measured at 5 kg at 235 °C according to standard ISO 1133.

[0278] According to another aspect, the present invention relates to a method for preparing the recycled semi - crystalline aliphatic polyamide as defined above, characterized in that it comprises the steps of washing and / or compounding the semi - crystalline aliphatic polyamide PA2 after removing used or end - of - life pipes from an offshore or onshore oil or gas deposit, especially an offshore deposit extraction platform and shredding the used or end - of - life pipes in particulate form.

[0279] According to another aspect, the present invention relates to the use of a composition as defined above for the preparation of an article obtained by extrusion.

[0280] According to yet another aspect, the present invention relates to a method for preparing a single-layer or multi-layer pipe, characterized in that it comprises the step of extruding a composition as defined above.

[0281] It should be understood that all the previously described embodiments are equally applicable to a composition "extruded" or characterized only by its viscosity, i.e., a composition having an intrinsic viscosity greater than or equal to 1.2 dl / g, notably from 1.2 dl / g to 1.7 dl / g, preferably from 1.4 dl / g to 1.7 dl / g, more preferably strictly greater than 1.4 dl / g, as measured in m-cresol at 20 °C according to ISO 307:2007. Description of the Drawings

[0282] Figure 1 Presents the odor field® of Jean-Noel Jaubert.

[0283] Figure 1 The meanings of the abbreviations used are shown in Table 1.

[0284] [Table 1]

[0285] Examples

[0286] The present invention will now be described in more detail by the following examples, which are not limiting.

[0287] The various compositions for preparing the pipes of the present invention are as follows:

[0288] Original PA11 1 = PA11 with Mn 28000 g / mol + 13% BBSA + 1% heat stabilizer (composed of 0.7% Lowinox® 44B25 phenol from Great Lakes and 0.3% Irgafos® 168 phosphite from Ciba).

[0289] Original PA11 2 = PA11 with Mn 282000 g / mol + 1% heat stabilizer (composed of 0.7% Lowinox® 44B25 phenol from Great Lakes and 0.3% Irgafos® 168 phosphite from Ciba).

[0290] ​Original PA12 1 = PA12 with Mn 26000 g / mol + 13% BBSA + 1% heat stabilizer (composed of 0.7% Lowinox® 44B25 phenol from Great Lakes and 0.3% Irgafos® 168 phosphite from Ciba).

[0291] Recy. PA11 1 = A composition consisting of 100% of the original PA11 1 as described above, derived from offshore pipelines shredded to a particle size range of 0.5 mm to 25 mm. The composition contains 350 ppm of isooctane, 412 ppm of methylcyclohexane, 460 ppm of xylene, 350 ppm of 2 - methylnaphthalene, and 300 ppm of phenanthrene. The composition also contains 0.1% of bitumen.

[0292] Recy. PA11 2 = A composition consisting of 100% of the original PA11 1 as described above, derived from offshore pipelines shredded to a particle size range of 0.5 mm to 25 mm and then washed with methanol at 60°C for 12 hours. The composition contains 6 ppm of isooctane, 3 ppm of methylcyclohexane, 12 ppm of xylene, 55 ppm of 2 - methylnaphthalene, and 26 ppm of phenanthrene.

[0293] Recy. PA11 3 = A composition consisting of 50% of the original PA11 1 as described above, derived from offshore pipelines shredded to a particle size range of 0.5 mm to 25 mm, then washed with methanol at 60°C for 12 hours, and then compounded with 50% of the original PA11 2 (without BBSA) under vacuum. The composition contains 3 ppm of isooctane, 1 ppm of methylcyclohexane, 5 ppm of xylene, 22 ppm of 2 - methylnaphthalene, and 15 ppm of phenanthrene.

[0294] Recy. PA11 4 = A composition consisting of 90% of the original PA11 1 as described above, derived from particles shredded to a size range of 0.5 mm to 25 mm, then washed with methanol at 60°C for 12 hours, and compounded with 10% of the original PA11 2, 0.5% of an antioxidant (composed of 0.35% Lowinox® 44B25 phenol from Great Lakes and 0.15% Irgafos® 168 phosphite from Ciba), and 600 ppm of a catalyst (H3PO4) from offshore pipelines. The composition contains 5 ppm of isooctane, 2 ppm of methylcyclohexane, 11 ppm of xylene, 46 ppm of 2 - methylnaphthalene, and 22 ppm of phenanthrene.

[0295] Recy. PA12 5 = A composition consisting of 70% virgin PA12 1 sourced from offshore pipelines, which is shredded into particles with a size range of 0.5 mm to 25 mm, then washed with methanol at 60 °C for 12 hours, and then compounded with 20% virgin PA12 2, 9.5% Orevac® IM800 impact modifier sold by SK FP, 0.5% antioxidant (composed of 0.35% Lowinox® 44B25 phenol from Great Lakes and 0.15% Irgafos® 168 phosphite from Ciba), and 600 ppm of catalyst (H3PO4) added. The composition contains 3 ppm isooctane, 24 ppm stearic acid, 5 ppm 4-methylbenzoic acid, 22 ppm 2-methylnaphthalene, and 33 ppm phenanthrene.

[0296] The Recy. PA11 3 composition is prepared by conventional compounding in a Coperion® 40 co-rotating twin-screw extruder at 70 kg / h, 300 rpm, 270 °C, and under strong degassing at -660 mmHg.

[0297] The Recy. PA11 4 composition is prepared by conventional compounding in a Coperion® 40 co-rotating twin-screw extruder at 70 kg / h, 300 rpm, 270 °C with the direct addition of 600 ppm of H3PO4 catalyst.

[0298] The Recy. PA12 5 composition is prepared by conventional compounding in a Coperion® 40 co-rotating twin-screw extruder at 70 kg / h, 300 rpm, 270 °C with the direct addition of 600 ppm of H3PO4 catalyst.

[0299] Alkanes and aromatic molecules (isooctane, methylcyclohexane, xylene, 2-methylnaphthalene, and phenanthrene) are analyzed by thermal desorption (dynamic headspace at 300 °C for 60 minutes) coupled with a gas chromatograph (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact (EI) source. Quantification is carried out in pentadecane equivalents.

[0300] To quantify acidic aromatic compounds or monocarboxylic acids, methanol extraction is required, followed by methylation derivatization of the dry extract to enhance detection. Analysis is carried out by a gas chromatograph (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact source. Quantification is carried out in pentadecane equivalents.

[0301] Extruded plates:

[0302] Two types of plates are prepared:

[0303] - Plate A is 250 mm wide, 5.5 mm thick and 1 m long

[0304] - Plate B is 250 mm wide, 1 mm thick and 1 m long

[0305] Before testing, to ensure the best performance of the plates and good extrusion quality, verify that the extruded material has a residual moisture content of less than 0.08% before extrusion. If this is not the case, an additional step of drying the material is carried out before testing, usually overnight at 80 °C in a vacuum dryer.

[0306] To manufacture the two types of plates, a Maillefer extruder with a screw diameter of 60 mm and a length of 24D, where D is the screw diameter, is used. A filtration system is not used at the end of the screw. The extruder feeds a 280 mm Yvroud die with an 8 mm air gap to manufacture Plate A and a 280 mm Yvroud die with a 3 mm air gap to manufacture Plate B. The screw speed is adjusted according to the sample geometry, calendering speed and drawing speed. The temperature of the three cooling cylinders ranges between 80 °C and 60 °C, depending on the product fluidity.

[0307] After the extrusion parameters are stabilized, plates meeting the characteristics described in this patent application are taken out, and the dimensions of the plates no longer change with time.

[0308] Generally, the temperature of the extruder and tools (head, connector and die) should be set high enough above the melting temperature of the composition under consideration so that they remain in a molten state, thus preventing them from solidifying and blocking the machine.

[0309] Then the plates produced by the above extrusion are evaluated according to several criteria:

[0310] The results are shown in Table 2.

[0311] [Table 2]

[0312]

[0313] Exudation is measured on 1 mm plates stored at 70 °C and 62% RH (relative humidity) for 7 days.

[0314] Exudation appears as the appearance of deposits on the surface and is evaluated visually.

[0315] The plates are graded from 1 (little exudation) to 5 (considerable exudation) by trained personnel.

[0316] Thermoforming was carried out on a 5.5 mm thick and 220 mm wide sheet obtained after cutting an extruded sheet on a Kiefel KD 20 / 25 machine. A "yogurt pot" type mold with a vertical wall 40 mm high and 60 mm in diameter was used. The heating system includes two infrared heating plates (upper and lower) to ensure uniform heating. The heating power was set to 100%. The forming time was 1 second. A pressure of 4 bar was applied to obtain good thermoforming. The heating times to obtain sufficient thermoforming temperature are listed in the table above. The composition of the present invention has an optimal compromise between exudation and heating time. In particular, the heating time of the composition of the present invention is shorter than that of the comparative compositions CE1, CE2 and CE3, and the exudation of the composition of the present invention is lower than that of the comparative compositions CE1, CE3 and CE4.

Claims

1. An extrusion composition comprising, by weight: a) 35% to 100%, in particular 35% to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2, said recycled semi-crystalline aliphatic polyamide PA2 being sourced from used or end-of-life pipelines used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 having undergone a washing and / or compounding step after removal of the pipeline and shredding of the pipeline into granules; b) 0 to 65%, in particular 0 to 10%, of at least one reinforcing fiber; c) 0 to 40%, in particular 3% to 30%, of at least one impact modifier; d) 0 to 30%, in particular 0 to 15%, of a filler; e) 0 to 10%, in particular 0.1% to 5%, of at least one additive; The sum of components a + b + c + d + e is equal to 100%, The intrinsic viscosity of the composition, measured in m-cresol at 20 °C according to ISO 307:2007, is greater than or equal to 1.2 dl / g, in particular in the range from 1.2 dl / g to 1.7 dl / g.

2. The extrusion composition according to claim 1, characterized in that, The recycled semi-crystalline aliphatic polyamide PA2 is a long-chain polyamide with an average number of carbon atoms per nitrogen atom greater than 7, in particular greater than 9.

3. The extrusion composition according to any one of claims 1 and 2, characterized in that The recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from sulfur compounds, alkanes, aliphatic C14-C18 monocarboxylic acids, monoaromatic or polyaromatic compounds, and aromatic acids.

4. The extruded composition according to any one of claims 1 to 3, characterized in that, The recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from alkanes, aliphatic C14-C18 monocarboxylic acids, monoaromatic or polyaromatic compounds, and aromatic acids.

5. The extrusion composition according to any one of claims 1 to 4, characterized in that, The recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from alkanes, monoaromatic compounds or polyaromatic compounds, and aromatic acids.

6. The extrusion composition according to any one of claims 1 to 5, characterized in that The recycled semi-crystalline aliphatic polyamide PA2 comprises at least one substance selected from the following: alkanes such as methylcyclopentane, cyclohexane, methylcyclohexane, 1,2-cis-dimethylcyclohexane, 1,2-trans-dimethylcyclohexane, 1,3-cis-dimethylcyclohexane, 1,3-trans-dimethylcyclohexane, 1,4-cis-dimethylcyclohexane, 1,4-trans-dimethylcyclohexane or ethylcyclohexane, and monoaromatic or polyaromatic compounds such as toluene, xylene, trimethylbenzene, diphenylmethane, diphenylmethanol, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1,2-dimethylnaphthalene, 1,3-dimethylnaphthalene, 1,4-dimethylnaphthalene, 1,3,6-trimethylnaphthalene, 2,3,5-trimethylnaphthalene, 1-phenanthrene and 2-methylphenanthrene.

7. The extrusion composition according to any one of claims 3 to 6, characterized in that, The mass content range of the substances present in the recycled semi-crystalline aliphatic polyamide PA2 is from 100 ppm to 2000 ppm, in particular from 100 ppm to 1000 ppm.

8. The extruded composition according to any one of claims 1 to 7, which has a characteristic odor comprising sulfur / pyrogen and / or hydrocarbon and / or aromatic compounds, terpene and phenolic atmosphere.

9. The extruded composition according to any one of claims 1 to 8, characterized in that, The recycled semi-crystalline aliphatic polyamide PA2 has functional groups generated by pyrolysis reaction in an acidic medium, in particular amide functional groups and / or the α-methylene and acid chain ends of said amide functional groups, which are selected from nitrile, ketone and ester functional groups generated by the reaction of the acid functional groups of the polyamide with alcohols used during the lifetime of the pipeline, and the molar ratio thereof relative to the amide functional groups is higher than that of the same polyamide constituting the unused pipeline.

10. The extrusion composition according to claim 9, characterized in that The molar ratio of the functional groups derived from the pyrolysis reaction is from 1 / 10000 to 1 / 20, as determined by proton NMR.

11. The extruded composition according to any one of claims 1 to 10, characterized in that, The recycled semi-crystalline aliphatic polyamide PA2 has a lower content of cyclic oligomers than the equivalent virgin polyamide, and the cyclic oligomers are selected from oligomers with a molar mass of less than 1000 g / mol.

12. The extrusion composition according to any one of claims 1 to 11, characterized in that, The recycled semi-crystalline aliphatic polyamide PA2 has an alkyl chain end content ranging from 1 ppm to 5000 ppm, advantageously 10 to 2500 ppm, the alkyl being C1 to C18, and the content is higher than that of the virgin semi-crystalline aliphatic polyamide.

13. A method for preparing a recycled semi-crystalline aliphatic polyamide as defined in any one of claims 1-12, characterized in that It comprises the steps of washing and / or compounding the semi-crystalline aliphatic polyamide PA2 after removing used or end-of-life pipelines from an offshore or onshore oil or gas deposit, in particular an offshore deposit, and shredding the used or end-of-life pipelines in particulate form.

14. Use of the composition as defined in any one of claims 1 to 12 for the preparation of an article obtained by extrusion.

15. A method for preparing a single-layer or multi-layer pipe, characterized in that It comprises the step of extruding the composition as defined in any one of claims 1 to 12.

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