Extruded compositions containing recycled polyamides obtained from the development of offshore or onshore oil or gas deposits

Abstract

The present invention provides 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, wherein the at least one semi-crystalline aliphatic polyamide PA1 comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2 recovered from pipes used or at the end of their life for the exploitation of offshore or onshore oil or gas deposits, in particular from offshore oil or gas deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after removal of the pipes and crushing to form 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 fillers; e) 0 to 10%, in particular 0.1 to 5%, of at least one additive, Including, The sum of components a+b+c+d+e is 100% the intrinsic viscosity of the composition, measured in m-cresol at 20°C according to ISO307:2007, is 1.2 dL / g or more, particularly in the range of 1.2 dL / g to 1.7 dL / g; It relates to extruded compositions.

Description

[Technical Field]

[0001] The present invention relates to extruded compositions containing recycled polyamide obtained from the development of offshore or onshore oil or gas deposits. [Background technology]

[0002] In the development of offshore or onshore oil and gas deposits, flexible pipes are required to connect various equipment around the platform. These pipes must withstand high-temperature oil, gas, water, and mixtures of at least two of these products for periods of up to 20 years. These pipes generally consist of an inner, unsealed metal layer formed by a spirally wound, profiled metal strip, such as staple foil, that gives the pipe its shape. A polymer is then extruded onto this layer to provide a seal, and other protective and reinforcing layers, such as metal fiber webs and rubber, are then finally added.

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

[0004] However, these pipes need to be cleaned, for example by circulating methanol to remove hydrates. A drawback of methanol is that it penetrates deeply into the polyamide, so that while the methanol is lost, plasticizers and / or modifiers may also be extracted from the polyamide by the methanol, leading to a loss of mechanical properties and premature deterioration of the pipe.

[0005] Furthermore, tens to hundreds of tons of long-chain polyamides obtained from pipes used in the exploitation of offshore or onshore oil and gas deposits must be recycled over the years due to the fact that they have reached the end of their useful life. However, these polyamides cannot be used after simple crushing due to the contaminants they contain, which come from the extracted oil or gas.

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

[0007] They must be crushed so that they can be converted into pieces with different shapes for different uses.

[0008] After grinding, recycled polyamides must also be washed and / or compounded to extract most of the contaminants (associated with the solvent, in the melt, under vacuum, etc.), however, extraction is not always complete.

[0009] Without this cleaning and / or blending step, the manufactured part will exhibit exudation, which can be toxic to the user and can cause the part to have a greasy appearance.

[0010] Furthermore, recycled polyamides may be largely hydrolyzed and therefore not extrudable, in which case they must be subjected to high vacuum (optionally with the addition of a catalyst) to increase their viscosity and make them extrudable. Summary of the Invention [Problem to be solved by the invention]

[0011] It is therefore necessary, firstly, to provide a composition that can be extruded in complete safety for the manipulator (no release of toxic gases) and, secondly, to be able to obtain extruded parts of all types that are stable over time (no leaching). [Means for solving the problem]

[0012] Accordingly, the present invention provides 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, wherein the at least one semi-crystalline aliphatic polyamide PA1 comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2 originating from used or end-of-life pipes that have been used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after removal of the pipes and crushing 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 fillers; e) 0 to 15%, in particular 0.1% to 10%, in particular 0.5% to 5% of at least one additive Including, The sum of components a+b+c+d+e is 100% the intrinsic viscosity of the composition, measured in m-cresol at 20°C according to ISO307:2007, is 1.2 dL / g or more, particularly in the range of 1.2 dL / g to 1.7 dL / g; It relates to extruded compositions. [Effects of the Invention]

[0013] The inventors have therefore discovered that recycled polyamide PA2, obtained from used or end-of-life pipes used in the exploitation of onshore or offshore oil or gas deposits, especially offshore ones, can be added to virgin polyamide PA1 to obtain a composition that can be extruded without emitting harmful or toxic gases (safety of the manipulators) for the production of any type of extruded part that exhibits no or low leaching. The composition of the invention has good mechanical properties and allows for improved quality and productivity of the weld between the two parts. DETAILED DESCRIPTION OF THE INVENTION

[0014] The development of offshore or onshore oil or gas deposits uses flexible pipes to connect the various offshore or onshore units of a platform, respectively, and to transport the extracted hydrocarbons.

[0015] These pipes must withstand high temperatures of oil, gas, water, and mixtures of at least two of these products for periods of up to 20 years.

[0016] The term "used" means that the pipe has already been used in the development of an oil or gas deposit, whether offshore or onshore, but has not yet reached the limit of its operation, which is a maximum of 20 years. When the platform is taken out of production and dismantled, this type of pipe needs to be recycled, as it has not yet reached the end of its useful life.

[0017] The term "end of life" means that the pipes have been used in the development of oil or gas deposits, whether offshore or onshore, and have reached their operational limit of up to 20 years. These pipes must therefore be removed from the operating system before they have completely deteriorated or have leak-tightness problems with respect to the oil or gas being transported.

[0018] About semi-crystalline aliphatic polyamide PA1 The polyamide PA1 can be a homopolyamide or a copolyamide or a mixture thereof.

[0019] The term "semi-crystalline aliphatic polyamide" refers to a material that is generally solid at room temperature, softens during temperature increase, especially after passing through its glass transition temperature (Tg), can melt rapidly as it passes through its "melting temperature" (Tm), and becomes solid again when the temperature drops below its crystallization temperature.

[0020] Tg, Tc and Tm are determined by differential scanning calorimetry (DSC) according to standards 11357-2:2013 and 11357-3:2013, respectively.

[0021] The number average molecular weight Mn of the semicrystalline polyamide is preferably in the range of 10,000 to 85,000, especially 10,000 to 60,000, preferably 10,000 to 50,000, and even more preferably 12,000 to 50,000.

[0022] The nomenclature used to define polyamides is described in the ISO 1874-1:2011 standard "Plastics - Polyamide (PA) molding and extrusion materials - Part 1: Designation", in particular page 3 (Tables 1 and 2), and is well known to those skilled in the art.

[0023] The at least one semi-crystalline aliphatic polyamide PA1 can result 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 with at least one dicarboxylic acid Y or mixtures thereof.

[0024] If the at least one aliphatic semi-crystalline polyamide PA1 results from the polycondensation of at least one lactam, the at least one lactam may be selected from C6 to C18, C8 to C18, preferentially C10 to C18 and more preferentially C10 to C12 lactams, the C6 to C18 lactam being in particular caprolactam, decanolactam, undecanolactam or lauryllactam.

[0025] When said at least one aliphatic semicrystalline polyamide PA1 results from the polycondensation of at least one lactam, it may thus comprise a single lactam or several lactams.

[0026] Advantageously, said at least one aliphatic semicrystalline polyamide PA1 results from the polycondensation of a single lactam, said lactam being chosen from lauryllactam and undecanolactam, advantageously lauryllactam.

[0027] If the at least one aliphatic semi-crystalline polyamide PA1 results from the polycondensation of at least one amino acid, the at least one amino acid may be selected from C8 to C18, preferentially C10 to C18, more preferentially C10 to C12 amino acids.

[0028] C8-C18 amino acids are especially 9-aminononanoic acid, 10-aminodecanoic acid, 10-aminoundecanoic acid, 12-aminododecanoic acid and 11-aminoundecanoic acid, and derivatives thereof, especially N-heptyl-11-aminoundecanoic acid.

[0029] When said at least one aliphatic semicrystalline polyamide PA1 results from the polycondensation of at least one amino acid, it may thus comprise a single amino acid or several amino acids.

[0030] Advantageously, said aliphatic semicrystalline polyamide PA1 results from the polycondensation of a single amino acid, said amino acid being chosen from 10-aminodecanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, advantageously 11-aminoundecanoic acid.

[0031] If the at least one semi-crystalline aliphatic polyamide PA1 results from the polycondensation of at least one diamine X with at least one aliphatic dicarboxylic acid Y, the diamine X is C4 to C36, preferentially C6 to C18, preferentially C6 to C12, more preferentially C10 to C12, and the aliphatic dicarboxylic acid Y is C6 to C36, preferentially C6 to C18, preferentially C6 to C12, more preferentially C10 to C12.

[0032] The diamine may be linear or branched. Advantageously, it is linear.

[0033] The at least one C4 to C36 diamine X may be chosen in particular 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, octadecenediamine, eicosanediamine, docosanediamine and diamines obtained from fatty acids.

[0034] Advantageously, the at least one diamine X is C4 to C18 and is chosen 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.

[0035] Advantageously, the at least one C6 to C12 diamine X is chosen in particular from 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine and 1,12-dodecamethylenediamine.

[0036] Advantageously, the at least one C6 to C12 diamine X is chosen in particular from 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine and 1,12-dodecamethylenediamine.

[0037] Advantageously, the diamine X used is a C10-C12 diamine chosen in particular from 1,10-decamethylenediamine, 1,11-undecamethylenediamine and 1,12-dodecamethylenediamine.

[0038] The at least one C6-C36 dicarboxylic acid Y may be selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, and diacids obtained from fatty acids.

[0039] The diacid may be linear or branched. Advantageously, it is linear.

[0040] Advantageously, the at least one dicarboxylic acid Y is a C6 to C18 dicarboxylic acid and is chosen from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid and octadecanedioic acid.

[0041] Advantageously, said at least one dicarboxylic acid Y is a C6 to C12 dicarboxylic acid and is chosen from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid.

[0042] Advantageously, said at least one dicarboxylic acid Y is a C10-C12 dicarboxylic acid and is chosen from sebacic acid, undecanedioic acid and dodecanedioic acid.

[0043] When said aliphatic semi-crystalline polyamide PA1 results from the polycondensation of at least one diamine X with at least one dicarboxylic acid Y, it may comprise a single diamine or several diamines and a single dicarboxylic acid or several dicarboxylic acids.

[0044] Advantageously, said aliphatic semicrystalline polyamide PA1 results from the polycondensation of a single diamine X with a single dicarboxylic acid Y.

[0045] 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, in particular greater than 9.

[0046] About recycled semi-crystalline aliphatic polyamide PA2 The polyamide PA2 can be a homopolyamide or a copolyamide or a mixture thereof.

[0047] The term "semi-crystalline aliphatic polyamide" refers to a material that is generally solid at room temperature, softens during temperature increase, especially after passing through its glass transition temperature (Tg), can melt rapidly as it passes through its "melting temperature" (Tm), and becomes solid again when the temperature drops below its crystallization temperature.

[0048] Tg, Tc and Tm are determined by differential scanning calorimetry (DSC) according to standards 11357-2:2013 and 11357-3:2013, respectively.

[0049] The number average molecular weight Mn of the semicrystalline polyamide is preferably in the range of 10,000 to 85,000, especially 10,000 to 60,000, preferably 10,000 to 50,000, and even more preferably 12,000 to 50,000.

[0050] Said at least one semi-crystalline aliphatic polyamide PA2 is initially obtained from the polycondensation of at least one lactam as described above for the semi-crystalline aliphatic polyamide PA1, or from the polycondensation of at least one amino acid, or from the polycondensation of at least one diamine X with at least one dicarboxylic acid Y or mixtures thereof, before being used in the exploitation of oil or gas deposits.

[0051] Advantageously, PA2 is PA11 or PA12, in particular PA11.

[0052] After use, i.e., after use or at the end of its life, pipes used in the exploitation of offshore or onshore oil or gas deposits, especially offshore deposits, are removed from the drilling platform, the various layers are separated, and the layer containing PA2 is crushed into crushed material (0.5 mm to 25 mm) or powder (size less than 0.5 mm), then washed and / or compounded, i.e., the pieces, whether washed or not, are placed at least once in an extruder, especially a twin-screw co-rotating or co-kneader (Buss) type, where they are remixed by melting, with or without the addition of at least one catalyst. The molten material leaves the extruder as a rod, which is cooled and cut into granules.

[0053] Advantageously, the number of blending movements is 1 to 10, in particular 1 to 5. The number of blending movements is especially 1, 2, 3, 4 or 5, in particular 1, 2 or 3.

[0054] When necessary, the pieces can be washed, as described below, using, inter alia, a solvent, in particular methanol or ethanol, to extract most of the contaminants from the development.

[0055] Blending may be carried out with the addition of a catalyst when necessary.

[0056] The term "catalyst" refers to a polycondensation catalyst such as a mineral or organic acid.

[0057] Advantageously, the proportion by weight of catalyst is between about 50 ppm and about 5000 ppm, and in particular between about 100 and about 3000 ppm, relative to the total weight of the composition.

[0058] Advantageously, the catalyst is chosen from phosphoric acid (H3PO4), phosphorous acid (H3PO3) and hypophosphorous acid (H3PO2), or mixtures thereof.

[0059] Advantageously, the present invention therefore relates to the use, as defined above, of at least one catalyst, at least one copper-based heat stabilizer and at least one oligo- or poly-carbodiimide in a weight proportion of from about 50 ppm to about 5000 ppm, in particular from about 100 to about 3000 ppm, relative to the total weight of the composition, with a matrix comprising at least one thermoplastic polymer, in particular a polyamide, wherein said catalyst is chosen from phosphoric acid (H3PO4), phosphorous acid (H3PO3), hypophosphorous acid (H3PO2) or mixtures thereof.

[0060] Advantageously, the catalyst is chosen from phosphoric acid (H3PO4), phosphorous acid (H3PO3) in proportions of between about 100 and about 3000 ppm.

[0061] In one embodiment, the recycled PA2 mixture is degassed during compounding.

[0062] In one embodiment, the degassing is weak, meaning that the degassing is in the range of -50 mmHg to -150 mmHg.

[0063] For example, this is done according to Protocol A below.

[0064] The washed or unwashed ground pipe is compounded in a Coperion / Werner 40 mm twin screw extruder at a set point of 70 kg / h, 300 rpm, 270° C. with a degassing of −100 mm Hg.

[0065] In another embodiment, the degassing is strong, meaning that the degassing is in the range of -550 mmHg to -750 mmHg.

[0066] For example, this is done according to protocol B below.

[0067] The washed or unwashed ground pipe is compounded in a Coperion / Werner 40 mm twin screw extruder at 70 kg / h, 300 rpm, 270° C. set point with strong degassing at −660 mm Hg.

[0068] Advantageously, degassing is carried out immediately after the melt zone in the extruder.

[0069] The intrinsic viscosity of the semi-crystalline aliphatic polyamide after grinding and washing, or after grinding and compounding with or without a catalyst, or after grinding, washing and compounding with or without a catalyst, is 1.2 dl / g or more, in particular in the range of 1.2 dl / g to 1.7 dl / g, measured in m-cresol at 20°C according to ISO 307:2007.

[0070] Thus, the ground, washed and / or compounded semi-crystalline aliphatic polyamide, with or without catalyst, with or without degassing, corresponds to the recycled semi-crystalline aliphatic polyamide PA2 of the composition of the invention.

[0071] 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.

[0072] In particular, recycled semi-crystalline aliphatic polyamide PA2 is a long-chain polyamide having an average number of carbon atoms per nitrogen atom of 7 to more than 12, in particular 7 to more than 11, in particular 9 to 12, especially 9 to 11.

[0073] In another embodiment, the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species selected from alkanes, aliphatic C14-C18 monoacids, mono- or polyaromatic compounds, and aromatic acids.

[0074] The alkane is especially 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.

[0075] The C14-C18 aliphatic monoacids are especially palmitic acid and stearic acid.

[0076] The C14-C18 aliphatic monoacids are also present in the initial virgin semi-crystalline aliphatic polyamide (1-100 ppm), but in the recycled semi-crystalline aliphatic polyamide PA2 they are present in higher concentrations (more than 100 ppm), in particular in the range of 500-5000 ppm.

[0077] Mono- or polyaromatic compounds are especially 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.

[0078] Aromatic acids are especially 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.

[0079] Advantageously, said recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species selected from sulfur compounds, alkanes, C14 to C18 aliphatic monoacids, mono- or polyaromatic compounds and aromatic acids.

[0080] More advantageously, said recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species selected from alkanes, mono- or polyaromatic compounds and aromatic acids.

[0081] Even more advantageously, said recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species selected from alkanes, mono- or polyaromatic compounds.

[0082] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species 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 mono- 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.

[0083] Advantageously, said recycled semi-crystalline aliphatic polyamide PA2 comprises at least one selected from bitumen in a content of between 0.1 and 500 ppm.

[0084] In one embodiment, the total mass content of said species present in the recycled semi-crystalline aliphatic polyamide PA2 is in the range of 1 ppm to 2000 ppm, such as 10 ppm to 2000 ppm, for example 50 ppm to 2000 ppm, for example 100 ppm to 2000 ppm, in particular 100 ppm to 1000 ppm, for example 100 ppm to 700 ppm, for example 100 ppm to 400 ppm. Preferably, the total mass content of said species present in the recycled PA2 semi-crystalline aliphatic polyamide is in the range of 10 ppm to 700 ppm, for example 50 ppm to 400 ppm.

[0085] In one embodiment, the mass content of each alkane in the recycled semi-crystalline aliphatic polyamide PA2 is 0.1 to 400 ppm, preferably 1 to 150 ppm.

[0086] 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, in particular from 5 to 100 ppm.

[0087] Alkanes and aromatic molecules are analyzed by thermal desorption (dynamic headspace at 300 °C for 60 min) coupled to gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact (EI) source. Quantification is performed in pentadecane equivalents.

[0088] In one embodiment, the mass content of each acidic aromatic compound in the recycled semi-crystalline aliphatic polyamide PA2 is 0.1 to 600 ppm, preferably 1 to 300 ppm, in particular 5 to 100 ppm.

[0089] In one embodiment, the mass content of each monoacid compound in the recycled semi-crystalline aliphatic polyamide PA2 is 0.1 to 600 ppm, preferably 1 to 300 ppm, in particular 5 to 100 ppm.

[0090] Quantitation of acidic aromatic compounds or monoacids requires methanol extraction, followed by methylation derivatization of the dried extract to enhance detection. Analysis is performed by gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact source. Quantitation is performed in pentadecane equivalents.

[0091] In another embodiment, the recycled semi-crystalline aliphatic polyamide PA2 has a characteristic odor comprising sulfur / pyrogenic and / or hydrocarbon and / or aromatic, terpene and phenolic notes.

[0092] The odors mentioned above are determined according to the description in the Odor Field® by Jean-Noel Jaubert.

[0093] The odor spectrum, developed in 1983, provides a methodology that allows, among other things, to describe olfactory perceptions in a universal way, i.e., as far as possible, without the need for individual elicitation. It was created by researcher Jean-Noel Jaubert based on the results of a research program on the chemical structure / odorant activity relationship of molecules present in the odorant world. This method, originally developed for the fragrance industry, makes it possible to describe, analyze, compare, and control complete products or odorant preparations that go beyond the usual classifications.

[0094] A drawback related to the odor problem is characteristic of recycled polyamide.

[0095] This defect is noticeable when opening a container of washed or unwashed pieces, or during extrusion and possibly in the final product.

[0096] Recycled polyamides have sulfur or aromatic odor notes (aromatic solvent odor, naphthalene). It is clearly possible to distinguish between virgin and recycled polyamides by smell.

[0097] In yet another embodiment, the recycled semi-crystalline aliphatic polyamide PA2 contains functional groups resulting from a pyrolysis reaction in an acidic medium, in particular amide functional groups and / or methylene alpha to said amide functional groups and acid chain ends, chosen from nitrile functional groups, ketone functional groups and ester functional groups resulting from the reaction of the acid functional groups of the polyamide with alcohols used during the life of the pipe, in a molar ratio to amide functional groups greater than that of the same polyamide constituting the virgin pipe.

[0098] In one embodiment, the molar ratio of functional groups resulting from the pyrolysis reaction is between 1 / 10,000 and 1 / 20 as determined by proton NMR.

[0099] The concentration can be measured by proton NMR in dichloromethane-d2 with the addition of HFIP (hexafluoroisopropanol) to dissolve the polyamide.

[0100] During petroleum extraction, an alcohol such as ethanol is used, which can react with the acid functional groups initially present on the semi-crystalline aliphatic polyamide to form ester functional groups.

[0101] In one embodiment, said recycled semi-crystalline aliphatic polyamide PA2 has a content of cyclic oligomers, selected from oligomers with a molar mass of less than 1000 g / mol, that is lower than the content in a comparable virgin polyamide.

[0102] The cyclic oligomer content is measured according to the following protocol.

[0103] Recycled semi-crystalline aliphatic polyamide PA2 granules were dissolved in a HFIP (CAS RN 920-66-1) / CHCl (CAS RN 75-09-3) mixture, and then a non-solvent (methanol CAS RN 67-56-1) was added, resulting in dissolution at low molar masses and precipitation at high molar masses.

[0104] The solution is filtered at 200 μm before analysis.

[0105] The oligomers are characterized as lactam-12 equivalents by reversed-phase liquid chromatography-mass spectrometry using positive electrospray ionization, with formic acid added to improve ionization.

[0106] A distribution of peaks is observed due to different molar masses (from monomers with linear or cyclic configuration to pentamers).

[0107] First, as a result of fluid transport, and second, as a result of washing, the polyamide has less oligomers than the same virgin semi-crystalline aliphatic polyamide due to said transport and washing extracting cyclic oligomers.

[0108] Advantageously, said recycled semi-crystalline aliphatic polyamide PA2 has a content of cyclic oligomers selected from oligomers with a molar mass of less than 1000 g / mol 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 a comparable virgin polyamide.

[0109] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 has a higher content of linear oligomers than virgin PA.

[0110] The weight content of cyclic oligomers in virgin polyamide ranges from monomer to pentamer (preferentially 1000 g.mol -1 The range is 500-10,000 ppm for each cyclic species up to 10,000 ppm (having a mass less than 100 ppm), with the cyclic dimer being the particularly predominant species.

[0111] In particular, if the mass is 1000 g.mol -1 The content of cyclic oligomers less than 4% by weight in virgin polyamide.

[0112] In one embodiment, the recycled semi-crystalline aliphatic polyamide PA2 has a content of cyclic oligomers with a molar mass of less than 1000 g / mol, ranging from 50 to 5000 ppm for each cyclic species from monomer to pentamer, but in any case lower than the content in an equivalent virgin polyamide.

[0113] The weight content of linear oligomers in virgin polyamide ranges from monomer to pentamer (preferentially 1000 g.mol -1 The range is 200-2000 ppm for each linear species up to 1000 ppm, with masses of less than 1000 ppm.

[0114] In one embodiment, the recycled semi-crystalline aliphatic polyamide PA2 has a content of linear oligomers with a molar mass of less than 1000 g / mol, ranging from 250 to 5000 ppm for each cyclic species from monomer to pentamer, but in any case higher than the content in an equivalent virgin polyamide.

[0115] In one embodiment, the recycled semi-crystalline aliphatic polyamide PA2 has a weight content of alkyl chain ends ranging from 1 ppm to 5000 ppm, advantageously from 10 to 2500 ppm, said alkyl being C1 to C18, said content being higher than the content in virgin semi-crystalline aliphatic polyamide.

[0116] About the composition In a first variant, the extruded composition according to the invention comprises, by weight: a) 35% to 100%, in particular 35% to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1, wherein the at least one semi-crystalline aliphatic polyamide PA1 comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2 originating from used or end-of-life pipes that have been used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after removal of the pipes and crushing 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 fillers; e) 0 to 10%, in particular 0.1% to 5%, of at least one additive Including, The sum of components a+b+c+d+e is 100%.

[0117] The composition is an extrusion composition and not an injection composition, i.e. not a molding composition.

[0118] In one embodiment of this first variant, the extruded composition according to the invention comprises, by weight: a) 35% to 97%, in particular 35% to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1, the at least one semi-crystalline aliphatic polyamide PA1 comprising at least 30%, in particular at least 50%, recycled semi-crystalline aliphatic polyamide PA2 originating from used or end-of-life pipes used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after removal of the pipes and grinding to a fine form, b) 0 to 65%, in particular 0 to 10%, of at least one reinforcing fiber; c) 3% to 30% of at least one impact modifier; d) 0 to 30%, in particular 0 to 15%, of fillers; e) 0 to 10%, in particular 0.1% to 5%, of at least one additive Including, The sum of components a+b+c+d+e is 100%.

[0119] In another embodiment of this first variant, the extruded composition according to the invention comprises, by weight: a) 35% to 96.9% of at least one semi-crystalline aliphatic polyamide PA1, wherein the at least one semi-crystalline aliphatic polyamide PA1 comprises at least 30%, in particular at least 50%, recycled semi-crystalline aliphatic polyamide PA2 originating from used or end-of-life pipes that have been used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after the removal of the pipes and crushing them into granules, b) 0 to 65%, in particular 0 to 10%, of at least one reinforcing fiber; c) 3% to 30% of at least one impact modifier; d) 0 to 30%, in particular 0 to 15%, of fillers; e) 0.1% to 5% of at least one additive Including, The sum of components a+b+c+d+e is 100%.

[0120] Advantageously, in this first variant and in its two embodiments, said composition consists of said components.

[0121] In a second variant, the extruded composition comprises, by weight: a) 35% to 100%, in particular 35% to 96.9%, of at least one semi-crystalline aliphatic polyamide PA1, the at least one semi-crystalline aliphatic polyamide PA1 comprising at least 30%, in particular at least 50%, recycled semi-crystalline aliphatic polyamide PA2 originating from used or end-of-life pipes used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after removal of the pipes and crushing them into granules, 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 fillers; e) 0 to 10%, in particular 0.1% to 5%, of at least one additive Including, The sum of components a+c+d+e is 100%.

[0122] In one embodiment of this second variant, reinforcing fibers are excluded from said extruded composition according to the invention.

[0123] In one embodiment of this second variant, the extruded composition according to the invention comprises, by weight: a) 35% to 97% of at least one semi-crystalline aliphatic polyamide PA1, wherein the at least one semi-crystalline aliphatic polyamide PA1 comprises at least 30%, in particular at least 50%, recycled semi-crystalline aliphatic polyamide PA2 originating from used or end-of-life pipes that have been used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after the removal of the pipes and crushing them into granules, c) 3% to 30% of at least one impact modifier; d) 0 to 30%, in particular 0 to 15%, of fillers; e) 0 to 10%, in particular 0.1% to 5%, of at least one additive Including, The sum of components a+b+c+d+e is 100%.

[0124] In another embodiment of this second variant, the extruded composition according to the invention comprises, by weight: a) 35% to 96.9% of at least one semi-crystalline aliphatic polyamide PA1, wherein the at least one semi-crystalline aliphatic polyamide PA1 comprises at least 30%, in particular at least 50%, recycled semi-crystalline aliphatic polyamide PA2 originating from used or end-of-life pipes that have been used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after the removal of the pipes and crushing them into granules, c) 3% to 30% of at least one impact modifier; d) 0 to 30%, in particular 0 to 15%, of fillers; e) 0.1% to 5% of at least one additive Including, The sum of components a+b+c+d+e is 100%.

[0125] Advantageously, in this second variant and its two embodiments, said composition consists of said components.

[0126] In one embodiment of these two variants and related embodiments, the extruded composition as defined above has a characteristic odor comprising sulfur and / or hydrocarbon and / or aromatic notes, as described in the Jean-Noel Jaubert Odor Range®.

[0127] In one embodiment of these two variants and the associated combinations, said semi-crystalline aliphatic polyamide PA1 comprises at least 40% recycled semi-crystalline aliphatic polyamide PA2 from used or end-of-life pipes used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits.

[0128] Advantageously, said semi-crystalline aliphatic polyamide PA1 comprises at least 50% of said recycled semi-crystalline aliphatic polyamide PA2.

[0129] Advantageously, said semi-crystalline aliphatic polyamide PA1 comprises at least 60% of said recycled semi-crystalline aliphatic polyamide PA2.

[0130] Advantageously, said semi-crystalline aliphatic polyamide PA1 comprises at least 70% of said recycled semi-crystalline aliphatic polyamide PA2.

[0131] Advantageously, said semi-crystalline aliphatic polyamide PA1 comprises at least 80% of said recycled semi-crystalline aliphatic polyamide PA2.

[0132] Advantageously, said semi-crystalline aliphatic polyamide PA1 comprises at least 90% of said recycled semi-crystalline aliphatic polyamide PA2.

[0133] In these last six embodiments, the semi-crystalline aliphatic polyamide PA1 is composed of the semi-crystalline aliphatic polyamide PA2 in the stated proportions.

[0134] According to any one of the embodiments of the present invention, the extrusion composition of the present invention may comprise at least one species selected from alkanes, aliphatic C14-C18 monoacids, mono- or polyaromatic compounds, and aromatic acids.

[0135] The alkane is especially 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.

[0136] The C14-C18 aliphatic monoacids are especially palmitic acid and stearic acid.

[0137] Mono- or polyaromatic compounds are especially 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.

[0138] Aromatic acids are especially 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.

[0139] Advantageously, the extrusion composition of the invention comprises at least one species chosen from sulfur compounds, alkanes, aliphatic C14 to C18 monoacids, mono- or polyaromatic compounds and aromatic acids.

[0140] More advantageously, the extrusion composition of the present invention comprises at least one species selected from alkanes, mono- or polyaromatic compounds and aromatic acids.

[0141] Even more advantageously, the extrusion composition of the present invention comprises at least one species selected from alkanes, mono- or polyaromatic compounds.

[0142] Advantageously, the extrusion composition of the present invention comprises at least one species 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 mono- 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.

[0143] Advantageously, the extrusion composition of the invention comprises at least one species chosen from bitumen in a content ranging from 0.1 to 500 ppm.

[0144] In one embodiment, the total mass content of said species present in the extruded composition of the invention is in the range of from 0.1 ppm to 2000 ppm, such as from 1 ppm to 1000 ppm, for example from 10 ppm to 300 ppm, such as from 20 ppm to 250 ppm, in particular from 30 ppm to 150 ppm. Preferably, the total mass content of said species present in the composition of the invention is in the range of from 1 ppm to 300 ppm, for example from 100 ppm to 150 ppm.

[0145] In one embodiment, the mass content of each alkane in the extrusion composition of the present invention is 0.1 to 400 ppm, preferably 1 to 150 ppm.

[0146] In one embodiment, the mass content of each aromatic compound in the extruded composition of the present invention is from 0.1 to 300 ppm, preferably from 1 to 150 ppm, especially from 5 to 100 ppm.

[0147] Alkanes and aromatic molecules are analyzed by thermal desorption (dynamic headspace at 300 °C for 60 min) coupled to gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact (EI) source. Quantification is performed in pentadecane equivalents.

[0148] In one embodiment, the mass content of each acidic aromatic compound in the extruded composition of the present invention is from 0.1 to 300 ppm, preferably from 1 to 150 ppm, especially from 5 to 100 ppm.

[0149] In one embodiment, the mass content of each monoacid compound in the extruded composition of the present invention is from 0.1 to 600 ppm, preferably from 1 to 300 ppm, especially from 5 to 100 ppm.

[0150] Quantitation of acidic aromatic compounds or monoacids requires methanol extraction, followed by methylation derivatization of the dried extract to enhance detection. Analysis is performed by gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact source. Quantitation is performed in pentadecane equivalents.

[0151] According to any one of the embodiments of the present invention, the extruded composition of the present invention may have a content of cyclic oligomers selected from oligomers with a molar mass of less than 1000 g / mol that is lower than that of the equivalent virgin polyamide.

[0152] The cyclic oligomer content is measured according to the following protocol.

[0153] 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 dissolving at low molar masses and precipitating at high molar masses.

[0154] The solution is filtered at 200 μm before analysis.

[0155] The oligomers are characterized as lactam-12 equivalents by reversed-phase liquid chromatography-mass spectrometry using positive electrospray ionization, with formic acid added to improve ionization.

[0156] A distribution of peaks is observed due to different molar masses (from monomers with linear or cyclic configuration to pentamers).

[0157] First, as a result of fluid transport, and second, as a result of washing, the polyamide has less oligomers than the same virgin semi-crystalline aliphatic polyamide due to said transport and washing extracting cyclic oligomers.

[0158] Advantageously, the extrusion composition of the invention has a content of cyclic oligomers selected from oligomers having a molar mass of less than 1000 g / mol 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, compared to the content of an identical extrusion composition comprising an equivalent virgin polyamide instead of the recycled semi-crystalline aliphatic polyamide PA2.

[0159] Advantageously, the extruded composition of the invention has a higher content of linear oligomers than the content of the same extruded composition containing an equivalent virgin polyamide instead of recycled semi-crystalline aliphatic polyamide PA2.

[0160] The weight content of cyclic oligomers in virgin polyamide ranges from monomer to pentamer (preferentially 1000 g.mol -1 The range is 500-10,000 ppm for each cyclic species up to 10,000 ppm (having a mass less than 100 ppm), with the cyclic dimer being the particularly predominant species.

[0161] In particular, if the mass is 1000 g.mol -1 The content of cyclic oligomers less than 4% by weight in virgin polyamide.

[0162] In one embodiment, the extrusion composition of the invention has a content of cyclic oligomers with a molar mass of less than 1000 g / mol, ranging from 50 to 5000 ppm for each cyclic species from monomer to pentamer, but in any case lower than the content of the same extrusion composition comprising an equivalent virgin polyamide instead of the recycled semi-crystalline aliphatic polyamide PA2.

[0163] The weight content of linear oligomers in the extrusion composition of the present invention ranges from monomer to pentamer (preferentially 1000 g.mol -1 The range is 200-2000 ppm for each linear species up to 100 ppm (having a mass less than 100 ppm).

[0164] In one embodiment, the extrusion composition of the invention has a content of linear oligomers with a molar mass of less than 1000 g / mol ranging from 250 to 5000 ppm for each cyclic species from monomer to pentamer, but in any case higher than the content of the same extrusion composition comprising an equivalent virgin polyamide instead of the recycled semi-crystalline aliphatic polyamide PA2.

[0165] In one embodiment, the extrusion composition of the invention comprises a weight content of alkyl chain ends ranging from 1 ppm to 5000 ppm, advantageously from 10 to 2500 ppm, said alkyl being C1 to C18, said content being greater than the content of an identical extrusion composition comprising an equivalent virgin polyamide instead of the recycled semi-crystalline aliphatic polyamide PA2.

[0166] Regarding reinforcing fiber (b) As regards the reinforcing fibres, these are short fibres, in particular fibres of mineral, organic or vegetable origin.

[0167] The reinforcing fibers may or may not be sized.

[0168] The reinforcing fibers may therefore contain up to 0.1% by weight of organic material (of the thermosetting or thermoplastic type) known as sizing.

[0169] Among fibers of mineral origin, mention may be made of, for example, carbon fibers, glass fibers, basalt fibers or basalt-based fibers, silica fibers, or silicon carbide fibers. Among fibers of organic origin, mention may be made of fibers based on thermoplastic or thermosetting polymers, such as semi-aromatic polyamide fibers, aramid fibers, or polyolefin fibers. Preferably, they are based on amorphous thermoplastic polymers and have a glass transition temperature (Tg) higher than the Tg of the constituent thermoplastic polymer or polymer blend of the pre-impregnated matrix if the polymer or blend is amorphous, or higher than the Tm of the constituent thermoplastic polymer or polymer blend of the pre-impregnated matrix if the polymer or blend is semi-crystalline. Among 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. These fibers of plant origin can be used pure, treated, or coated with other coating layers to facilitate adhesion and impregnation of the thermoplastic polymer matrix.

[0170] Preferably, the reinforcing fibers are selected from glass fibers, carbon fibers, basalt fibers and basalt-based fibers.

[0171] More preferably, said reinforcing fibres are selected from carbon fibres and glass fibres.

[0172] In one embodiment, the reinforcing fibers present in a) are glass fibers.

[0173] The glass fibers may be of circular or non-circular cross section.

[0174] A fiber of circular cross section is defined as a fiber having any point around its circumference that is equal in distance to the center of the fiber, and thus represents a complete or nearly complete circle.

[0175] Thus, any glass fiber that does not have this perfect or nearly perfect circle is defined as a fiber of non-circular cross section.

[0176] Examples of fibers with non-circular cross-sections include, but are not limited to, non-circular fibers having an elliptical, oval or cocoon shape, star-shaped fibers, flake-shaped fibers, flat fibers, crosses, polygons and rings.

[0177] Glass fiber is - any circular cross section with a diameter of 4 μm to 25 μm, preferably 4 to 15 μm; or a non-circular cross section with an L / D ratio of 2 to 8, in particular 2 to 4, where L represents the largest dimension of the cross section of the fiber and D represents the smallest dimension of the cross section of said fiber. L and D can be measured by scanning electron microscopy (SEM).

[0178] Advantageously, the glass fibres are circular.

[0179] The glass fibres are in particular of type E, R, S2 or T. Advantageously, the glass fibres are of type E.

[0180] Regarding impact modifiers (c): Impact modifier represents 0 to 40%, in particular 3% to 30% of at least one impact modifier.

[0181] In one embodiment, it represents 5% to 20%.

[0182] By way of example, the impact modifier is a polyolefin or a thermoplastic elastomer having a modulus of elasticity of less than 200 MPa, in particular less than 100 MPa, measured at 23° C. according to standard ISO 178:2010.

[0183] In one embodiment, the impact modifier is selected from functionalized or non-functionalized polyolefins, and mixtures thereof, having a modulus of less than 200 MPa, in particular less than 100 MPa.

[0184] Polyolefin: The polyolefin may be functionalized, unfunctionalized, or a blend thereof.

[0185] For simplicity, polyolefins are designated (B), and functionalized polyolefins (B1) and non-functionalized polyolefins (B2) are described below.

[0186] The non-functionalized polyolefins (B2) are conventionally homopolymers or copolymers of alpha-olefins or diolefins, such as ethylene, propylene, 1-butene, 1-octene or butadiene. Examples that may be mentioned include:

[0187] polyethylene homopolymers and copolymers, in particular LDPE, HDPE, LLDPE (linear low density polyethylene), VLDPE (very low density polyethylene) and metallocene polyethylene; propylene homopolymers or copolymers, ethylene / α-olefins, such as ethylene / propylene copolymers, EPR (abbreviation for ethylene propylene rubber) and ethylene / propylene / diene (EPDM) copolymers; - copolymers of ethylene and at least one product chosen from salts or esters of unsaturated carboxylic acids, such as alkyl (meth)acrylates (for example methyl acrylate), or vinyl esters of saturated carboxylic acids, such as vinyl acetate (EVA), in which the proportion of comonomer can be up to 40% by weight.

[0188] The functionalized polyolefin (B1) may be a polymer of an alpha-olefin having reactive units (functional groups). Such reactive units are acid, anhydride, or epoxy functional groups. Examples include the aforementioned polyolefins (B2) grafted, copolymerized, or tripolymerized with unsaturated epoxides such as glycidyl (meth)acrylate, or carboxylic acids such as (meth)acrylic acid (which can be fully or partially neutralized with metals such as Zn), or the corresponding salts or esters, or carboxylic acid anhydrides such as maleic anhydride. The functionalized polyolefin may be, for example, a PE / EPR mixture, the weight ratio of which may vary within a wide range, for example, from 40 / 60 to 90 / 10, co-grafted with an anhydride, especially maleic anhydride, at a grafting degree of, for example, 0.01% to 5% by weight.

[0189] The functionalized polyolefin (B1) can be chosen from the following (co)polymers grafted with maleic anhydride or glycidyl methacrylate, the degree of grafting being, for example, between 0.01% and 5% by weight:

[0190] PE, PP, copolymers of ethylene with propylene, butene, hexene or octene, for example containing from 35% to 80% by weight of ethylene; ethylene / α-olefins, such as ethylene / propylene copolymers, EPR (abbreviation for ethylene propylene rubber) and ethylene / propylene / diene (EPDM) copolymers; - styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS) and styrene / ethylene-propylene / styrene (SEPS) block copolymers; - copolymers of ethylene and vinyl acetate (EVA) containing up to 40% by weight of vinyl acetate; - copolymers of ethylene and alkyl(meth)acrylate containing up to 40% by weight of alkyl(meth)acrylate; - Copolymers of ethylene, vinyl acetate (EVA) and alkyl (meth)acrylates containing up to 40% by weight of comonomer.

[0191] The functionalized polyolefin (B1) may also be chosen from ethylene / propylene copolymers, predominantly in propylene, grafted with maleic anhydride and then condensed with monoaminopolyamides (or polyamide oligomers) (products described in EP 0 342 066).

[0192] The functionalized polyolefin (B1) may also be a copolymer or terpolymer of at least the following units: (1) ethylene, (2) alkyl (meth)acrylate or saturated carboxylic acid vinyl ester, and (3) an anhydride such as maleic anhydride, or (meth)acrylic acid, or an epoxy such as glycidyl (meth)acrylate.

[0193] As examples of functionalized polyolefins of the latter type, the following copolymers may be mentioned, in which ethylene preferably represents at least 60% by weight and the termonomer (functional group) represents, for example, 0.1% to 10% by weight of the copolymer:

[0194] - ethylene / alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymers; -ethylene / vinyl acetate / maleic anhydride or glycidyl methacrylate copolymers; Ethylene / vinyl acetate or alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymers.

[0195] In the above copolymers, the (meth)acrylic acid can be salified with Zn or Li.

[0196] The term "alkyl (meth)acrylate" in (B1) or (B2) refers to C1 to C8 alkyl methacrylates and acrylates, and may be selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, methyl methacrylate, and ethyl methacrylate.

[0197] Furthermore, the polyolefins (B1) may also be crosslinked via any suitable method or agent (diepoxy, diacid, peroxide, etc.) The term "functionalized polyolefin" also includes mixtures of the above polyolefins with difunctional reagents such as diacids, dianhydrides, diepoxy, etc. that can react with these polyolefins, or mixtures of at least two functionalized polyolefins that can react with each other.

[0198] The copolymers (B1) and (B2) may be copolymerized randomly or in a block manner and may have a linear or branched structure.

[0199] The molecular weight, MFI index and density of these polyolefins can also vary within wide limits, as will be understood by those skilled in the art. MFI is the abbreviation for Melt Flow Index. It is measured at 235°C and 5 kg according to standard ISO 1133.

[0200] Advantageously, the non-functionalized polyolefin (B2) is chosen from polypropylene homopolymers or copolymers and any ethylene homopolymers or copolymers of ethylene and a comonomer of 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 as being produced according to the "radical" process, according to "Ziegler" type catalysis or, more recently, according to "metallocene" catalysis.

[0201] 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 acid anhydride functional groups. Examples of such polymers include terpolymers of ethylene, alkyl acrylate, and maleic anhydride or glycidyl methacrylate, such as Lotader® products (SK Functional Polymer), or polyolefins grafted with maleic anhydride, such as Orevac® products (SK Functional Polymer), as well as terpolymers of ethylene, alkyl acrylate, and (meth)acrylic acid. Mention may also be made of polypropylene homopolymers or copolymers grafted with carboxylic acid anhydrides and then condensed with monoaminopolyamides or monoaminopolyamide oligomers.

[0202] In one embodiment, the polyolefin is crosslinked.

[0203] In another embodiment, the polyolefin is a mechanical blend of a thermoplastic olefin-based polymer with a polyethylene or polypropylene matrix, and a vulcanized elastomer, such as a vulcanized PP / EPDM blend.

[0204] Thermoplastic elastomers are block copolymers (ether amide block copolymers: PEBA), ether-ester block copolymers, thermoplastic polyurethanes: TPU, and thermoplastic styrene-based elastomers.

[0205] Regarding filler (d): Filler represents 0-30%, in particular 0-15% filler.

[0206] In one embodiment, the filler represents 1% to 5%.

[0207] By way of example, the fillers may be chosen from silica, graphite, expanded graphite, carbon black, kaolin, magnesia, slag, talc, wollastonite, nanofillers (carbon nanopipes), pigments, metal oxides (titanium oxide) and metals, advantageously wollastonite and talc, preferentially talc or carbon black.

[0208] Additive (e) Additives are optional and comprise 0 to 10.0 wt %, particularly 0.1 wt % to 5.0 wt %.

[0209] The additives are selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, brighteners, antioxidants, lubricants, flame retardants, natural waxes, chain extenders, and mixtures thereof.

[0210] Advantageously, the additives are selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, brighteners, antioxidants, flame retardants, natural waxes, chain extenders, and mixtures thereof.

[0211] More preferably, the additives are selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, brighteners, antioxidants, natural waxes, chain extenders, and mixtures thereof.

[0212] 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., types Irganox® 245, 1098, or 1010 from Ciba-BASF), phosphite antioxidants (e.g., Irgafos® 126 from Ciba-BASF), and optionally HALS, which stands for hindered amine light stabilizer (e.g., Tinuvin® 770 from Ciba-BASF), UV stabilizers (e.g., Tinuvin® 312 from Ciba), or phosphorus-based stabilizers. Amine-type antioxidants, such as Naugard® 445 from Crompton, or multifunctional stabilizers, such as Nylostab® S-EED from Clariant, can also be used.

[0213] 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 copper halides. Other metals, such as silver, may also be considered, but are known to be less effective. These copper-based compounds are typically combined with alkali metal halides, particularly potassium halides.

[0214] By way of example, the plasticizer may be selected from benzenesulfonamide derivatives, such as n-butylbenzenesulfonamide (BBSA); ethyltoluenesulfonamide or N-cyclohexyltoluenesulfonamide; esters of hydroxybenzoic acid, such as 2-ethylhexyl parahydroxybenzoate and 2-decylhexyl parahydroxybenzoate; esters or ethers of tetrahydrofurfuryl alcohol, such as oligoethyleneoxytetrahydrofurfuryl alcohol; and esters of citric acid or hydroxymalonic acid, such as oligoethyleneoxymalonate.

[0215] It would not be outside the scope of the present invention to use a mixture of plasticizers.

[0216] In one embodiment, the composition according to the invention contains less than 5%, advantageously less than 2% of plasticizer.

[0217] In another embodiment, the composition has an MFI of 0.5 to 25, measured at 235° C. and 5 kg according to standard ISO 1133.

[0218] According to another aspect, the present invention relates to a process for the preparation of recycled semi-crystalline aliphatic polyamides as defined above, characterized in that it comprises a step of washing and / or compounding said semi-crystalline aliphatic polyamide PA2 after removal of used or end-of-life pipes from offshore or onshore oil or gas deposits, in particular from the development platforms of offshore deposits, and crushing them into granules.

[0219] According to another aspect, the invention relates to the use of a composition as defined above for manufacturing an article obtained by extrusion.

[0220] According to yet another aspect, the invention relates to a method for manufacturing a single-layer or multi-layer pipe, characterized in that it comprises a step of extruding the composition defined above.

[0221] It will be understood that all the foregoing embodiments apply equally to "extruded" compositions or compositions simply characterized by their viscosity, i.e. compositions having an intrinsic viscosity of 1.2 dl / g or more, in particular between 1.2 dl / g and 1.7 dl / g, preferably between 1.4 and 1.7 dl / g, more preferably strictly above 1.4 dl / g, measured in m-cresol at 20°C according to ISO 307:2007. [Brief explanation of the drawings]

[0222] [Figure 1] Jean-Noel Jaubert's Odor Zone (R) is shown.

[0223] The meanings of the abbreviations used in Figure 1 are shown in Table 1.

[0224] [Table 1] [Example]

[0225] The present invention will now be described in more detail by the following non-limiting examples.

[0226] The various compositions used in the manufacture of the pipe of the present invention are as follows:

[0227] Virgin PA11 1 = Mn 28,000 g / mol + 13% BBSA + 1% heat stabilizer PA11 (consisting of 0.7% Lowinox® 44B25 phenol from Great Lakes, 0.3% Irgafos® 168 phosphite from Ciba).

[0228] Virgin PA11 2 = 2000 g / mol of Mn PA11 28 + 1% heat stabilizer (consisting of 0.7% Lowinox® 44B25 phenol from Great Lakes, 0.3% Irgafos® 168 phosphite from Ciba).

[0229] Virgin PA12 1 = Mn 26,000 g / mol + 13% BBSA + 1% heat stabilizer PA12 (consisting of 0.7% Lowinox® 44B25 phenol from Great Lakes, 0.3% Irgafos® 168 phosphite from Ciba).

[0230] Recycled PA11 1 = A composition consisting of 100% virgin PA11 1 as described above, obtained from marine pipe that has been crushed to a particle size range of 0.5 mm to 25 mm. The composition contains 350 ppm isooctane, 412 ppm methylcyclohexane, 460 ppm xylene, 350 ppm 2-methylnaphthalene, and 300 ppm phenanthrene. The composition also contains 0.1% bitumen.

[0231] Recycled PA11 2 = A composition consisting of 100% virgin PA11 1, as described above, obtained from marine pipe that has been crushed to particle sizes ranging from 0.5 mm to 25 mm and then washed with methanol at 60°C for 12 hours. The composition contains 6 ppm isooctane, 3 ppm methylcyclohexane, 12 ppm xylene, 55 ppm 2-methylnaphthalene, and 26 ppm phenanthrene.

[0232] Recycled PA11 3 = A composition consisting of 50% virgin PA11 1 obtained from marine pipe that has been crushed to a particle size range of 0.5 mm to 25 mm and then washed with methanol at 60°C for 12 hours, and then blended under vacuum with 50% virgin PA11 2 that does not contain BBSA. The composition contains 3 ppm isooctane, 1 ppm methylcyclohexane, 5 ppm xylene, 22 ppm 2-methylnaphthalene, and 15 ppm phenanthrene.

[0233] Recycled PA11 4 = A composition consisting of 90% virgin PA11 1 obtained from marine pipe that was crushed into particles ranging in size from 0.5 mm to 25 mm, then washed with methanol at 60°C for 12 hours, and compounded with 10% virgin PA11 2, 0.5% antioxidant (0.35% Lowinox® 44B25 phenol from Great Lakes and 0.15% Irgafos® 168 phosphite from Ciba), and 600 ppm catalyst (H3PO4). The composition contains 5 ppm isooctane, 2 ppm methylcyclohexane, 11 ppm xylene, 46 ppm 2-methylnaphthalene, and 22 ppm phenanthrene.

[0234] Recycled PA12 5 = A composition consisting of 70% virgin PA12 1 from marine pipes, crushed into particles ranging in size from 0.5 mm to 25 mm, washed with methanol at 60°C for 12 hours, and then blended with 20% virgin PA12 2, 9.5% Orevac® IM800 impact modifier sold by SK FP, 0.5% antioxidant (consisting of 0.35% Lowinox® 44B25 phenol from Great Lakes and 0.15% Irgafos® 168 phosphite from Ciba), and the addition of 600 ppm catalyst (H3PO4). The composition also contains 3 ppm isooctane, 24 ppm stearic acid, 5 ppm 4-methylbenzoic acid, 22 ppm 2-methylnaphthalene, and 33 ppm phenanthrene.

[0235] The recycled composition PA11 3 was produced by conventional compounding in a Coperion® 40 co-rotating twin screw extruder, 70 kg / h, 300 rpm, 270° C., with strong degassing at −660 mmHg.

[0236] The recycled composition PA11 4 was produced by conventional compounding in a Coperion® 40 co-rotating twin screw extruder at 70 kg / h, 300 rpm, 270°C with direct addition of 600 ppm H3PO4 catalyst.

[0237] The recycled composition PA12 5 was produced by conventional compounding in a Coperion® 40 co-rotating twin screw extruder at 70 kg / h, 300 rpm, 270°C with direct addition of 600 ppm H3PO4 catalyst.

[0238] Alkanes and aromatic molecules (isooctane, methylcyclohexane, xylene, 2-methylnaphthalene, and phenanthrene) are analyzed by thermal desorption (dynamic headspace at 300 °C for 60 min) coupled to gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact (EI) source. Quantification is performed in pentadecane equivalents.

[0239] Quantitation of acidic aromatic compounds or monoacids requires methanol extraction, followed by methylation derivatization of the dried extract to enhance detection. Analysis is performed by gas chromatography (C18 column) equipped with a flame ionization detector and a mass spectrometer equipped with an electron impact source. Quantitation is performed in pentadecane equivalents.

[0240] Extrusion Plate: Prepare two types of plates.

[0241] -Plate A: Width 250mm, thickness 5.5mm, length 1m - Plate B: Width 250mm, thickness 1mm, length 1m

[0242] Prior to testing, to ensure the best plate properties and good quality extrusion, ensure that the extruded material has a pre-extrusion residual moisture content of less than 0.08%. If this is not the case, an additional step of drying the material is performed prior to testing, typically overnight at 80°C in a vacuum oven.

[0243] To produce both types of plates, a Maillefer extruder with a screw diameter of 60 mm and a length of 24 D, where D is the screw diameter, was used. No filtration system was used at the end of the screw. The extruder was equipped with a 280 mm Yvroud die with an 8 mm air gap to produce Plate A and a 280 mm Yvroud die with a 3 mm air gap to produce Plate B. The screw speed was adjusted according to the sample geometry, calendering speed, and drawing speed. The temperatures of the three cooling cylinders ranged from 80 °C to 60 °C depending on the product's flowability.

[0244] Plates meeting the characteristics described in this patent application are taken after the extrusion parameters have stabilised and the dimensions of the plates no longer change over time.

[0245] In general, the temperatures of the extruder and tools (head, connector and die) should be set sufficiently higher than the melting temperature of the composition under consideration so that the composition remains molten, thus preventing it from solidifying and clogging the machine.

[0246] The plates produced by the above extrusion were then evaluated on several criteria:

[0247] The results are shown in Table 2.

[0248] [Table 2]

[0249] The exudation is measured on 1 mm plates, which are stored at 70° C. and 62% RH (relative humidity) for 7 days.

[0250] Exudation is manifested by the appearance of deposits on the surface and is assessed visually.

[0251] Plates are graded by trained personnel from 1 (slight exudation) to 5 (significant exudation).

[0252] Thermoforming was performed on plates 5.5 mm thick and 220 mm wide, obtained after cutting the extrusion plates on a Kiefel KD 20 / 25 machine. A "yogurt pot"-type mold with a vertical wall height of 40 mm and a diameter of 60 mm was used. The heating system included two infrared heating plates (top and bottom) 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 required to obtain a sufficient thermoforming temperature are listed in the table above. The inventive composition offers the best compromise between exudation and heating time. In particular, the heating time of the inventive composition is shorter than that of comparative compositions CE1, CE2, and CE3, and the exudation of the inventive composition is less than that of comparative compositions CE1, CE3, and CE4.

Claims

1. 1. 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, wherein the at least one semi-crystalline aliphatic polyamide PA1 comprises at least 30%, in particular at least 50%, of recycled semi-crystalline aliphatic polyamide PA2 originating from used or end-of-life pipes that have been used in the exploitation of offshore or onshore oil or gas deposits, in particular offshore deposits, and wherein the recycled semi-crystalline aliphatic polyamide PA2 has undergone a washing and / or compounding step after removal of the pipes and crushing them 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 fillers; e) 0 to 10%, in particular 0.1% to 5%, of at least one additive; Including, The sum of components a+b+c+d+e is 100%; the intrinsic viscosity of the composition, measured in m-cresol at 20°C according to ISO 307:2007, is 1.2 dl / g or more, in particular in the range of 1.2 dl / g to 1.7 dl / g; Extruded composition.

2. 2. The extrusion composition according to claim 1, characterized in that 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.

3. 3. The extrusion composition according to claim 1 or 2, characterized in that the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species selected from sulfur compounds, alkanes, aliphatic C14-C18 monoacids, mono- or polyaromatic compounds and aromatic acids.

4. 4. The extrusion composition according to claim 1, wherein the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species selected from alkanes, aliphatic C14-C18 monoacids, mono- or polyaromatic compounds and aromatic acids.

5. 5. The extrusion composition according to claim 1, wherein the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species selected from alkanes, mono- or polyaromatic compounds and aromatic acids.

6. 6. The extrusion composition according to claim 1, wherein the recycled semi-crystalline aliphatic polyamide PA2 comprises at least one species 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 mono- 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. 7. The extrusion composition according to claim 3, wherein the mass content of the species present in the recycled semi-crystalline aliphatic polyamide PA2 ranges from 100 ppm to 2000 ppm, in particular from 100 ppm to 1000 ppm.

8. 8. Extruded composition according to one of claims 1 to 7, having a characteristic odor comprising sulfur / pyrogen and / or hydrocarbon and / or aromatic, terpene and phenolic notes.

9. 9. The extrusion composition according to claim 1, wherein the recycled semi-crystalline aliphatic polyamide PA2 has functional groups resulting from a pyrolysis reaction in an acidic medium, in particular amide functional groups and / or methylene alpha to the amide functional groups, and acid chain ends selected from nitrile, ketone and ester functional groups resulting from the reaction of the acid functional groups of the polyamide with alcohols used during the life of the pipe, in a molar ratio to the amide functional groups greater than that of the same polyamide constituting the virgin pipe.

10. 10. The extrusion composition of claim 9, wherein the molar ratio of functional groups derived from the pyrolysis reaction is between 1 / 10,000 and 1 / 20 as determined by proton NMR.

11. 11. The extrusion composition according to claim 1, wherein the recycled semi-crystalline aliphatic polyamide PA2 comprises cyclic oligomers selected from oligomers with a molar mass of less than 1000 g / mol, the content of cyclic oligomers being lower than the content of an equivalent virgin polyamide.

12. 12. The extrusion composition according to claim 1, wherein the recycled semi-crystalline aliphatic polyamide PA2 has a content of alkyl chain ends ranging from 1 ppm to 5000 ppm, advantageously from 10 to 2500 ppm, said alkyls being C1 to C18, said content being higher than that of virgin semi-crystalline aliphatic polyamide.

13. 13. Process for producing recycled semi-crystalline aliphatic polyamide according to one of claims 1 to 12, characterized in that it comprises a step of washing and / or compounding the semi-crystalline aliphatic polyamide PA2 after removal and crushing into granules of used or end-of-life pipes from offshore or onshore oil or gas deposits, in particular from development platforms for offshore deposits.

14. Use of a composition according to one of claims 1 to 12 for producing an article obtained by extrusion.

15. A method for producing a single-layer or multi-layer pipe, characterized in that it comprises a step of extruding a composition according to one of claims 1 to 12.

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