Injection molding composition comprising recycled polyamide recovered when exploiting offshore or shore oil or gas deposits

Abstract

The present invention relates to a moulding composition comprising, by weight: a) 35 to 100%, in particular 35 to 91.9%, of at least one semi-crystalline aliphatic polyamide PA1 comprising at least 30%, in particular at least 50%, of a recycled semi-crystalline aliphatic polyamide PA2 from the production of offshore or ashore 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 being subjected to a washing and / or compounding step when the conduits are removed and ground to form particulates; b) 0 to 65%, in particular 5 to 50%, 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 the components a + b + c + d + e being equal to 100%.

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 typically 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 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, several tens to several 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] Polyamides (PA) derived from pipes used in the exploitation of offshore or onshore oil and gas deposits cannot be used as they are.

[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, for example, during its use step, and can produce a greasy appearance on the finished part.

[0010] In addition, the polyamides to be recycled may be hydrolyzed to a large extent and thus not extrudable. In such cases, they have to be exposed to a high vacuum (optionally with addition of a catalyst) to increase their viscosity and make them suitable for use in injection molding. Summary of the Invention

[0011] Therefore, it must be possible to obtain a composition which does not emit harmful gases during its use step and does not exude over time. This firstly allows injection molding to be carried out completely safely for the operator and, secondly, provides injection molded parts of all types which are stable over time.

[0012] Accordingly, the present invention relates to an extrusion composition comprising, by weight:

[0013] a) 35% to 100%, in particular 35% to 91.9%, 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 and grinding of the pipeline into granules;

[0014] b) 0 - 65%, in particular 5 - 50%, 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] Thus, the 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, in particular offshore deposits, to virgin polyamide PA1 makes it possible to obtain a composition suitable for injection molding, which has good mechanical properties, exhibits little or no exudation and allows improved quality and productivity of the welding between two parts. The composition is used in a form which is completely safe for the operator since it does not release any harmful or toxic gases and allows all types of injection molded parts to be obtained which exhibit little or no exudation.

[0020] The exploitation of offshore or onshore oil or gas deposits uses flexible pipes to connect the various offshore or onshore installations of a platform respectively and for transporting the extracted hydrocarbons.

[0021] These pipes must withstand hot oil, gas, water and mixtures of at least two of these products for a period of up to 20 years.

[0022] The term "used" means that the pipe has been used for the exploitation of oil or gas deposits, 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 pipe that has not reached the end of its service life needs to be recycled.

[0023] The term "end of life" means that the pipe has been used for the exploitation of oil or gas deposits, whether offshore or onshore, but has reached its operating limit of up to 20 years. Therefore, these pipes 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.

[0024] Regarding semi-crystalline aliphatic polyamide PA1

[0025] The polyamide PA1 can be a homopolyamide or a copolyamide or a mixture thereof.

[0026] The term "semi-crystalline aliphatic polyamide" refers to a material that is usually solid at room temperature and softens during temperature increase, in particular 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.

[0027] Tg, Tc and Tm are determined by differential scanning calorimetry (DSC) according to standards 11357-2:2013 and 11357-3:2013 respectively.

[0028] 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.

[0029] The nomenclature used to define polyamides is described in 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.

[0030] 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.

[0031] 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 notably include caprolactam, laurolactam, undecanolactam or dodecanolactam.

[0032] 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.

[0033] 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 lauryl lactam and undecalactam, advantageously lauryl lactam.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] When said 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, diamine X is C4-C36, preferably C6-C18, preferably C6-C12, more preferably C10-C12, and said aliphatic dicarboxylic acid Y is C6-C36, preferably C6-C18, preferably C6-C12, more preferably C10-C12.

[0039] The diamine can be straight-chain or branched. Advantageously, it is straight-chain.

[0040] 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, and 1,18-octadecamethylenediamine, octadecenediamine, eicosanediamine, docosanediamine, and diamines obtained from fatty acids.

[0041] 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.

[0042] 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.

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

[0045] The at least one C6 to C36 dicarboxylic acid Y can 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 diacids obtained from fatty acids.

[0046] The diacid can be straight-chain or branched-chain. Advantageously, it is straight-chain.

[0047] Advantageously, the at least one dicarboxylic acid Y is a C6 to 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.

[0048] Advantageously, the at least one dicarboxylic acid Y is a C6 to C12 dicarboxylic acid and is selected from adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic acid.

[0049] Advantageously, the at least one dicarboxylic acid Y is a C10 to C12 dicarboxylic acid and is selected from sebacic acid, undecanedioic acid and dodecanedioic acid.

[0050] When the 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.

[0051] Advantageously, the aliphatic semi-crystalline polyamide PA1 is obtained from the polycondensation of a single diamine X and a single dicarboxylic acid Y.

[0052] In one embodiment, the recycled semi-crystalline aliphatic polyamide PA1 is a long-chain polyamide with an average number of carbon atoms per nitrogen atom greater than 7, particularly greater than 9.

[0053] Regarding the recycled semi-crystalline aliphatic polyamide PA2

[0054] The polyamide PA2 can be a homopolyamide or a copolyamide or a mixture thereof.

[0055] The term "semi-crystalline aliphatic polyamide" refers to a material that is usually 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.

[0056] Tg, Tc and Tm are determined by differential scanning calorimetry (DSC) according to standards 11357-2:2013 and 11357-3:2013 respectively.

[0057] The number average molecular weight Mn of the semi-crystalline polyamide preferably extends in the range of 10,000 to 85,000, notably 10,000 to 60,000, preferably 10,000 to 50,000, and even more preferably 12,000 to 50,000.

[0058] 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 before being used for the exploitation of oil or gas deposits, as described above for semi-crystalline aliphatic polyamide PA1.

[0059] Advantageously, PA 2 is PA 11 or PA 12, especially PA11.

[0060] 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 type or a kneader (Buss) type extruder, 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.

[0061] 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.

[0062] If necessary, solvents, especially methanol or ethanol, can be used to wash the fragments in particular in order to extract the vast majority of the pollutants from the exploitation, as described below.

[0063] If necessary, compounding can be carried out in the presence of a catalyst.

[0064] The term "catalyst" denotes a polycondensation catalyst, such as an inorganic acid or an organic acid.

[0065] 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.

[0066] Advantageously, the catalyst is selected from phosphoric acid (H3PO4), phosphorous acid (H3PO3) and hypophosphorous acid (H3PO2) or a mixture thereof.

[0067] Advantageously, the present invention thus relates to the use of at least one catalyst as defined above, at least one organic or copper-based heat stabilizer and at least one chain extender selected from polycarbodiimides, poly(maleic anhydride) or polyepoxides with a matrix comprising at least one thermoplastic polymer, in particular a polyamide, wherein the weight proportion of the catalyst is 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, and the catalyst is selected from phosphoric acid (H3PO4), phosphorous acid (H3PO3), hypophosphorous acid (H3PO2) or mixtures thereof.

[0068] Advantageously, the catalyst is selected from phosphoric acid (H3PO4), phosphorous acid (H3PO3), in a proportion of from about 100 to about 3000 ppm.

[0069] In one embodiment, the PA2 mixture to be recycled is degassed during compounding.

[0070] In one embodiment, the degassing is weak, meaning that the degassing range is from -50 mmHg to -150 mmHg.

[0071] For example, it is carried out according to the following Scheme A:

[0072] The washed or unwashed ground tubes are compounded on a Coperion / Werner 40 mm twin-screw extruder, 70 kg / h, 300 rpm, 270 °C set point, with a degassing of about 100 mmHg.

[0073] In another embodiment, the degassing is strong, meaning that the degassing range is from -550 mmHg to -750 mmHg.

[0074] For example, it is carried out according to the following Scheme B:

[0075] The washed or unwashed ground tubes are compounded on a Coperion / Werner 40 mm twin-screw extruder, 70 kg / h, 300 rpm, 270 °C set point, with a strong degassing of -660 mmHg.

[0076] Advantageously, the degassing is carried out just after the melting zone in the extruder.

[0077] Advantageously, 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 chopping, washing and compounding (with or without catalyst), the intrinsic viscosity of the semi-crystalline aliphatic polyamide is less than 1.6 dl / g, in particular in the range from 0.9 dl / g to 1.5 dl / g.

[0078] 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.

[0079] 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, particularly greater than 9.

[0080] 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, particularly greater than 9 to 12, notably greater than 9 to 11.

[0081] In another embodiment, 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.

[0082] 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.

[0083] The C14 to C18 aliphatic monocarboxylic acids are notably palmitic acid and stearic acid.

[0084] 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), particularly 500-5000 ppm.

[0085] 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.

[0086] 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.

[0087] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 contains at least one substance selected from sulfur compounds, alkanes, C14-C18 aliphatic monocarboxylic acids, monoaromatic or polyaromatic compounds, and aromatic acids.

[0088] More advantageously, the recycled semi-crystalline aliphatic polyamide PA2 contains at least one substance selected from alkanes, monoaromatic or polyaromatic compounds, and aromatic acids.

[0089] Even more advantageously, the recycled semi-crystalline aliphatic polyamide PA2 contains at least one substance selected from alkanes and monoaromatic or polyaromatic compounds.

[0090] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 contains 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.

[0091] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 contains at least one substance selected from bitumen with a content of 0.1-500 ppm.

[0092] 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 PA2 semi-crystalline aliphatic polyamide is from 10 ppm to 700 ppm, such as 50 ppm to 400 ppm.

[0093] 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.

[0094] In one embodiment, the mass content range of each aromatic compound in the recycled semi-crystalline aliphatic polyamide PA2 is from 0.1 to 600 ppm, preferably from 1 to 300 ppm, and particularly from 5 to 100 ppm.

[0095] 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.

[0096] 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, and particularly from 5 to 100 ppm.

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

[0098] 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.

[0099] In another embodiment, the recycled semi-crystalline aliphatic polyamide PA2 has a characteristic odor comprising a sulfur / pyrogen and / or hydrocarbon and / or aromatic compound, terpene and phenolic atmosphere.

[0100] The above-mentioned odor is determined according to the description of Odor Field® by Jean-Noél Jaubert.

[0101] The odor field developed in 1983 in particular provides a method that enables olfactory perception to be described in a common way, namely 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.

[0102] The disadvantages related to the odor problem are characteristic of the recycled polyamide.

[0103] This disadvantage can be perceived when opening the container of the washed or unwashed chips, or during extrusion and possibly for the finished product.

[0104] The recycled polyamide has an atmosphere of sulfur or aromatic compound odor (aromatic solvent odor, naphthalene). The difference between the virgin polyamide and the recycled polyamide can clearly be smelled.

[0105] 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 relative to the amide functional groups is greater than that of the same polyamide constituting the unused pipe.

[0106] 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 or by mass spectrometry after extraction or hydrolysis in an acidic medium and then by GC / MS analysis with electron impact.

[0107] The concentration can be measured by proton NMR in dichloromethane-d2, where HFIP (hexafluoroisopropanol) is added to dissolve the polyamide.

[0108] During oil extraction, an alcohol such as ethanol is used (in the in-service pipe), which can react with the acid functional groups initially present in the semi-crystalline aliphatic polyamide to form ester functional groups.

[0109] 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 with a molar mass of less than 1000 g / mol.

[0110] The content of cyclic oligomers is measured according to the following protocol:

[0111] The particles of the recycled semi-crystalline aliphatic polyamide PA2 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.

[0112] Before injection molding, the solution is filtered at 200 μm. 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.

[0113] Due to the different molar masses (from monomer to pentamer in linear or cyclic form), a peak distribution is observed.

[0114] As a result of first fluid transporting and then washing, the polyamide has fewer oligomers than the same virgin semi-crystalline aliphatic polyamide, because the transporting and washing extract cyclic oligomers.

[0115] 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 virgin polyamide, and the cyclic oligomers are selected from oligomers having a molar mass of less than 1000 g / mol.

[0116] Advantageously, the recycled semi-crystalline aliphatic polyamide PA2 has a higher content of linear oligomers than the virgin PA.

[0117] For each cyclic species from monomer to pentamer (preferably having a mass of less than 1000 g.mol -1 ), the weight content of cyclic oligomers in the virgin polyamide is 500 to 10,000 ppm, and the cyclic dimer is particularly the main species.

[0118] In particular, in the virgin polyamide, the content of cyclic oligomers having a mass of less than 1000 g.mol -1 is at most 4% by weight.

[0119] In one embodiment, for each cyclic species 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 virgin polyamide.

[0120] For each linear species from monomer to pentamer (preferably having a mass of less than 1000 g.mol -1 ), the weight content of linear oligomers in the virgin polyamide is 200 - 2000 ppm.

[0121] In one embodiment, for each cyclic species 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 virgin polyamide.

[0122] 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 virgin semi-crystalline aliphatic polyamide.

[0123] Regarding the composition

[0124] In a first variant, the molding composition according to the invention comprises, by weight:

[0125] a) 35% to 100%, especially 35% to 91.9%, of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, especially 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, especially offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 undergoing a washing and / or compounding step after removal and grinding of the pipeline into granules;

[0126] b) 0 to 65%, especially 5 to 50%, of at least one reinforcing fiber;

[0127] c) 0 to 40%, especially 3% to 30%, of at least one impact modifier;

[0128] d) 0 to 30%, especially 0 to 15%, of a filler;

[0129] e) 0 to 10%, especially 0.1% to 5%, of at least one additive;

[0130] The sum of components a + b + c + d + e is equal to 100%.

[0131] The composition is an injection molding composition and is not an extrusion composition.

[0132] )))) In a first embodiment of this first variant, the molding composition according to the invention comprises, by weight:

[0133] a) 35% to 95%, especially 35% to 91.9%, of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, especially 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, especially offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 undergoing a washing and / or compounding step after removal and grinding of the pipeline into granules;

[0134] b) 5 to 50% of at least one reinforcing fiber;

[0135] c) 0 to 40%, especially 3% to 30%, of at least one impact modifier;

[0136] d) 0 to 30%, especially 0 to 15%, of a filler;

[0137] e) 0 to 10%, in particular 0.1% to 5% of at least one additive;

[0138] The sum of components a + b + c + d + e is equal to 100%. )))

[0140] In a second embodiment of this first variant, the moulding composition according to the invention comprises, by weight:

[0141] a) 35% to 97%, in particular 35% to 91.9% 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 granules;

[0142] b) 0 to 65%, in particular 5 to 50% of at least one reinforcing fibre;

[0143] c) 3% to 30% of at least one impact modifier;

[0144] d) 0 to 30%, in particular 0 to 15% of a filler;

[0145] e) 0 to 10%, in particular 0.1% to 5% of at least one additive,

[0146] The sum of components a + b + c + d + e is equal to 100%.

[0147] Advantageously, in a third embodiment of this first variant, the moulding composition according to the invention comprises, by weight:

[0148] a) 35% to 99.9%, in particular 35% to 91.9% 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 granules;

[0149] b) 0 to 65%, in particular 5 to 50% of at least one reinforcing fibre;

[0150] c) 0 to 40%, in particular 3% to 30% of at least one impact modifier;

[0151] d) 0 to 30%, especially 0 to 15% filler;

[0152] e) 0.1% to 5% of at least one additive,

[0153] The sum of components a + b + c + d + e is equal to 100%.

[0154] Advantageously, in this first variant and its three embodiments, the composition consists of the said ingredients.

[0155] In a second variant, the moulding composition comprises by weight:

[0156] a) 35% to 92%, especially 35% to 91.9% of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, especially at least 50% of recycled semi-crystalline aliphatic polyamide PA2, the 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, especially offshore deposits, and the recycled semi-crystalline aliphatic polyamide PA2 undergoing a washing and / or compounding step after removal and shredding of the pipeline into granules;

[0157] b) 5 to 50% of at least one reinforcing fibre;

[0158] c) 5% to 50% of at least one impact modifier;

[0159] ))) c) 3% to 30% of at least one impact modifier;

[0160] d) 0 to 30%, especially 0 to 15% filler;

[0161] e) 0 to 10%, especially 0.1% to 5% of at least one additive;

[0162] The sum of components a + b + c + d + e is equal to 100%.

[0163] In one embodiment of this second variant, the moulding composition according to the invention comprises by weight:

[0164] a) 35% to 91.9% of at least one semi-crystalline aliphatic polyamide PA1, which comprises at least 30%, especially at least 50% of recycled semi-crystalline aliphatic polyamide PA2, the 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, especially offshore deposits, and the recycled semi-crystalline aliphatic polyamide PA2 undergoing a washing and / or compounding step after removal and shredding of the pipeline into granules;

[0165] b) at least one reinforcing fiber in an amount of 5 to 50%;

[0166] c) at least one impact modifier in an amount of 3% to 30%;

[0167] d) filler in an amount of 0 to 30%, particularly 0 to 15%;

[0168] e) at least one additive in an amount of 0.1% to 5%,

[0169] The sum of components a + b + c + d + e is equal to 100%.

[0170] Advantageously, in this second variant and its embodiments, the composition consists of said ingredients.

[0171] In a third variant, the molding composition according to the invention comprises by weight:

[0172] a) at least one semi-crystalline aliphatic polyamide PA1 in an amount of 35% to 94.9%, particularly 35% to 91.9%, which comprises at least 30%, particularly 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, particularly offshore deposits, and said recycled semi-crystalline aliphatic polyamide PA2 having undergone a washing and / or compounding step after removal and shredding of the pipeline into granules;

[0173] b) at least one reinforcing fiber in an amount of 5 to 50%;

[0174] c) at least one impact modifier in an amount of 0 to 40%, particularly 3% to 30%;

[0175] d) filler in an amount of 0 to 30%, particularly 0 to 15%;

[0176] e) at least one additive in an amount of 0.1% to 5%,

[0177] The sum of components a + b + c + d + e is equal to 100%.

[0178] In an embodiment of these three variants and related embodiments, the molding 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®.

[0179] In an embodiment of these three variants and related combinations,

[0180] 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, particularly offshore deposits.

[0181] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 50% of the recycled semi-crystalline aliphatic polyamide PA2.

[0182] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 60% of the recycled semi-crystalline aliphatic polyamide PA2.

[0183] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 70% of the recycled semi-crystalline aliphatic polyamide PA2.

[0184] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 80% of the recycled semi-crystalline aliphatic polyamide PA2.

[0185] Advantageously, the semi-crystalline aliphatic polyamide PA1 comprises at least 90% of the recycled semi-crystalline aliphatic polyamide PA2.

[0186] In these last six embodiments, the semi-crystalline aliphatic polyamide PA1 consists of the semi-crystalline aliphatic polyamide PA2 in said proportions.

[0187] According to any one of the embodiments of the present invention, the moulding 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.

[0188] Notable alkanes are 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.

[0189] Notable C14 to C18 aliphatic monocarboxylic acids are palmitic acid and stearic acid.

[0190] Notable monoaromatic or polyaromatic compounds are 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.

[0191] 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.

[0192] Advantageously, the molding composition according to the invention comprises at least one substance selected from sulfur compounds, alkanes, aliphatic C14-C18 monocarboxylic acids, monoaromatic or polyaromatic compounds, and aromatic acids.

[0193] More advantageously, the molding composition according to the invention comprises at least one substance selected from alkanes, monoaromatic or polyaromatic compounds, and aromatic acids.

[0194] Even more advantageously, the molding composition according to the invention comprises at least one substance selected from alkanes and monoaromatic or polyaromatic compounds.

[0195] Advantageously, the molding composition according to the 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.

[0196] Advantageously, the molding composition according to the invention comprises at least one substance selected from pitch in a content of 0.1 - 500 ppm.

[0197] In one embodiment, the total mass content of the substances present in the molding composition according to the 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 molding composition according to the invention ranges from 1 ppm to 300 ppm, such as from 100 ppm to 150 ppm.

[0198] In one embodiment, the mass content of each alkane in the molding composition according to the invention is 0.1 - 400 ppm, preferably 1 - 150 ppm.

[0199] In one embodiment, the mass content of each aromatic compound in the molding composition of the present invention is 0.1 - 300 ppm, preferably 1 - 150 ppm, particularly 5 - 100 ppm.

[0200] Alkanes and aromatic molecules are analyzed by thermal 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.

[0201] In one embodiment, the mass content of each acidic aromatic compound in the molding composition of the present invention is 0.1 - 300 ppm, preferably 1 - 150 ppm, particularly 5 - 100 ppm.

[0202] In one embodiment, the mass content of each monoacid compound in the molding composition of the present invention is between 0.1 and 600 ppm, preferably between 1 and 300 ppm, notably from 5 to 100 ppm.

[0203] 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.

[0204] According to any one of the embodiments of the present invention, the content of cyclic oligomers in the molding 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.

[0205] The content of cyclic oligomers is measured according to the following protocol:

[0206] The particles of the molding composition of the present invention 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.

[0207] Before analysis, the solution is filtered at 200 μm.

[0208] 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.

[0209] Due to the different molar masses (from monomer to pentamer in linear or cyclic form), a peak distribution is observed.

[0210] As a result of first fluid transporting and then washing, the polyamide has fewer oligomers than the same virgin semi-crystalline aliphatic polyamide, because the transporting and washing extract cyclic oligomers.

[0211] Advantageously, the molding 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 molding composition comprising the equivalent virgin polyamide instead of the recycled semi-crystalline aliphatic polyamide PA2.

[0212] Advantageously, the content of linear oligomers in the molding composition of the present invention is higher than that of the same molding composition comprising the equivalent virgin polyamide instead of the recycled semi-crystalline aliphatic polyamide PA2.

[0213] For each cyclic species from monomer to pentamer (preferably having a mass of less than 1000 g.mol -1 ), the weight content of cyclic oligomers in the virgin polyamide ranges from 500 to 10,000 ppm, with cyclic dimers being the major species in particular.

[0214] In particular, in the virgin polyamide, the content of cyclic oligomers having a mass of less than 1000 g.mol -1 is at most 4% by weight.

[0215] In one embodiment, for each cyclic species from monomer to pentamer, the content of cyclic oligomers having a molar mass of less than 1000 g / mol in the molding composition of the present invention is 50 - 5000 ppm, but in any case, it is lower than that of the same molding composition comprising the equivalent virgin polyamide instead of the recycled semi-crystalline aliphatic polyamide PA2.

[0216] For each linear species from monomer to pentamer (preferably having a mass of less than 1000 g.mol -1 ), the weight content of linear oligomers in the molding composition of the present invention ranges from 200 to 2000 ppm.

[0217] In one embodiment, for each cyclic species from monomer to pentamer, the molding composition of the present invention has a content range of linear oligomers having a molar mass of less than 1000 g / mol of 250 - 5000 ppm, but in any case, it is higher than that of the same molding composition comprising the equivalent virgin polyamide instead of the recycled semi-crystalline aliphatic polyamide PA2.

[0218] In one embodiment, the molding composition of the present invention comprises an alkyl chain end weight content in the range of 1 ppm - 5000 ppm, advantageously 10 - 2500 ppm, wherein the alkyl is C1 - C18, and the content is higher than that of the same molding composition containing equivalent virgin polyamide rather than recycled semi-crystalline aliphatic polyamide PA2.

[0219] Regarding the reinforcing fiber (b)

[0220] Regarding the reinforcing fibers, these are short fibers, which are notably fibers of mineral, organic or plant origin.

[0221] The reinforcing fibers may or may not be sized.

[0222] Thus, the reinforcing fibers may contain up to 0.1% by weight of a material of organic nature (of the thermosetting or thermoplastic resin type) called sizing.

[0223] 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 that of the thermoplastic polymer or polymer blend constituting the pre-impregnated 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 pre-impregnated 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 fibers of plant origin may be used in pure form, treated or coated with a coating.

[0224] Preferably, the reinforcing fibers are selected from glass fibers, carbon fibers, basalt fibers and basalt-based fibers.

[0225] More advantageously, the reinforcing fibers are selected from carbon fibers and glass fibers.

[0226] In one embodiment, the reinforcing fibers present in a) are glass fibers.

[0227] The glass fibers may have a circular or non-circular cross-section.

[0228] 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.

[0229] Therefore, any glass fiber that does not have such a perfect or nearly perfect circular shape is defined as a fiber having a non-circular cross-section.

[0230] Examples of fibers with non-circular cross-sections are, but not limited to, non-circular fibers such as elliptical, oval, or cocoon-shaped fibers, star-shaped fibers, flake-shaped fibers, fibers with a flat shape, cross-shaped, polygonal, and annular.

[0231] The glass fiber can be:

[0232] - a circular cross-section with a diameter of 4 μm to 25 μm, preferably 4 μm to 15 μm;

[0233] - 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).

[0234] Advantageously, the glass fiber is circular.

[0235] The glass fiber is notably of type E, R, S2, or T. Advantageously, the glass fiber is of type E.

[0236] Regarding the impact modifier (c):

[0237] The impact modifier represents 0 to 40%, especially 3% to 30% of at least one impact modifier.

[0238] In one embodiment, it accounts for 5% to 20%.

[0239] 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.

[0240] In one embodiment, the impact modifier is selected from functionalized or non-functionalized polyolefins and their mixtures with a modulus < 200 MPa, especially < 100 MPa.

[0241] Polyolefin:

[0242] The polyolefin can be functionalized, non-functionalized, or a blend thereof.

[0243] For simplicity, the polyolefin has been denoted as (B), and the functionalized polyolefin (B1) and the non-functionalized polyolefin (B2) are described below.

[0244] The non-functionalized polyolefin (B2) is generally a homopolymer or copolymer of an α-olefin or a diene (such as ethylene, propylene, 1-butene, 1-octene, or butadiene). Examples that can be mentioned include:

[0245] - Polyethylene homopolymers and copolymers, especially LDPE, HDPE, LLDPE (linear low density polyethylene), VLDPE (very low density polyethylene) and metallocene polyethylene,

[0246] - Polypropylene homopolymers or copolymers,

[0247] - Ethylene / α-olefins, such as ethylene / propylene copolymers, EPR (abbreviation for ethylene propylene rubber) and ethylene / propylene / diene (EPDM) copolymers,

[0248] - Copolymers of ethylene with at least one product selected from the following: 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 the comonomer may be up to 40% by weight.

[0249] The functionalized polyolefin (B1) can be a polymer of α-olefins having reactive units (functional groups); such reactive units are acid, anhydride or epoxy functional groups. For example, mention may be made of the aforementioned polyolefins (B2) grafted, copolymerized or terpolymerized with unsaturated epoxides such as glycidyl (meth)acrylate, or with carboxylic acids or the corresponding salts or esters such as (meth)acrylic acid (the latter can be completely or partially neutralized with metals such as Zn, etc.), or with carboxylic anhydrides 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 anhydride, especially maleic anhydride, and the grafting degree is, for example, from 0.01% to 5% by weight.

[0250] The functionalized polyolefin (B1) can be selected from the following (co)polymers grafted with maleic anhydride or glycidyl methacrylate, with a grafting degree of, for example, 0.01% to 5% by weight:

[0251] - PE, PP, copolymers of ethylene with propylene, butene, hexene or octene, which contain, for example, from 35% to 80% by weight of ethylene;

[0252] - Ethylene / α-olefins, such as ethylene / propylene copolymers, EPR (abbreviation for ethylene propylene rubber) and ethylene / propylene / diene (EPDM) copolymers;

[0253] - Styrene / ethylene-butene / styrene (SEBS), styrene / butadiene / styrene (SBS), styrene / isoprene / styrene (SIS) and styrene / ethylene-propylene / styrene (SEPS) block copolymers;

[0254] - Copolymer of ethylene and vinyl acetate (EVA), containing up to 40% by weight of vinyl acetate;

[0255] - Copolymer of ethylene and alkyl (meth)acrylate, containing up to 40 wt% of alkyl (meth)acrylate;

[0256] - Copolymer of ethylene and vinyl acetate (EVA) and alkyl (meth)acrylate, containing up to 40% by weight of comonomers.

[0257] 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) (products described in EP-A-0342066).

[0258] 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 saturated carboxylate, and (3) acid anhydride such as maleic anhydride, or (meth)acrylic acid, or epoxy such as glycidyl (meth)acrylate.

[0259] 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 ter monomer (functional group) accounts for, for example, 0.1% to 10% by weight of the copolymer:

[0260] - Ethylene / alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymer;

[0261] - Ethylene / vinyl acetate / maleic anhydride or glycidyl methacrylate copolymer;

[0262] - Ethylene / vinyl acetate or alkyl (meth)acrylate / (meth)acrylic acid or maleic anhydride or glycidyl methacrylate copolymer.

[0263] In the aforementioned copolymers, (meth)acrylic acid can be salted with Zn or Li.

[0264] The term “alkyl (meth)acrylate” in (B1) or (B2) means C1-C8 alkyl methacrylate and C1-C8 alkyl acrylate, and can be selected from methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, methyl methacrylate and ethyl methacrylate.

[0265] In addition, the above-mentioned polyolefins (B1) can also be crosslinked via any suitable method or reagent (diepoxides, diacids, peroxides, etc.); the term "functionalized polyolefins" also includes mixtures of the above-mentioned polyolefins with bifunctional reagents such as diacids, dianhydrides, diepoxides, etc. that are capable of reacting with these polyolefins, or mixtures of at least two functionalized polyolefins capable of reacting with each other.

[0266] The above-mentioned copolymers (B1) and (B2) can be copolymerized in a random or block manner and can have a linear or branched structure.

[0267] 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 an abbreviation for the melt flow index. It is measured at 235 °C under 5 kg according to standard ISO 1133.

[0268] 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 (e.g., 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 polyethylene 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.

[0269] The functionalized polyolefin (B1) is advantageously selected from any polymer containing α-olefin units and units with polar reactive functional groups (e.g., epoxy, carboxylic acid, or carboxylic anhydride functional groups). As examples of such polymers, mention may be made of terpolymers of ethylene, alkyl acrylate, 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, alkyl acrylate, and (meth)acrylic acid. Also mention may be made of polypropylene homopolymers or copolymers grafted with carboxylic anhydride and then condensed with monoamino polyamide or monoamino polyamide oligomers.

[0270] In one embodiment, the polyolefin is crosslinked.

[0271] 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.

[0272] Thermoplastic elastomers are block copolymers (ether-amide block copolymers: PEBA), ether-ester block copolymers, thermoplastic polyurethanes: TPU, thermoplastic styrene elastomers).

[0273] Regarding filler (d):

[0274] The filler represents 0 to 30%, in particular 0 to 15% of the filler.

[0275] In one embodiment, the filler accounts for 1% to 5%.

[0276] For example, the filler may 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.

[0277] Regarding additive (e)

[0278] The additive is optional and accounts for 0 to 10.0% by weight, in particular 0.1% to 5.0% by weight.

[0279] The additive is selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, brighteners, antioxidants, lubricants, flame retardants, natural waxes, chain extenders, bases, and mixtures thereof.

[0280] Advantageously, the additive is selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, brighteners, antioxidants, flame retardants, natural waxes, chain extenders, bases, and mixtures thereof.

[0281] More advantageously, the additive is selected from dyes, stabilizers, plasticizers, surfactants, nucleating agents, pigments, brighteners, antioxidants, natural waxes, chain extenders, bases, and mixtures thereof.

[0282] 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.

[0283] The stabilizer can 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 generally combined with halides of alkali metals (especially potassium).

[0284] For example, the plasticizer is selected from benzenesulfonamide derivatives, such as n-butylbenzenesulfonamide (BBSA); ethyltoluenesulfonamide or N-cyclohexyltoluenesulfonamide; 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 hydroxypropanedioic acid, such as oligoethyleneoxy propanedioate.

[0285] The use of a mixture of plasticizers will not constitute a departure from the scope of the invention.

[0286] For example, the bases used are zinc or calcium stearate, potassium hydroxide (KOH), sodium hydroxide (NaOH), and magnesium and calcium carbonates.

[0287] In one embodiment, the composition according to the invention comprises less than 5% and advantageously less than 2% of plasticizer.

[0288] In another embodiment, the composition has an MFI of 0.5 to 25 measured at 235 °C under 5 kg according to standard ISO 1133.

[0289] In still another embodiment, the intrinsic viscosity of the composition (determined in m-cresol at 20 °C according to ISO 307:2007) is less than or equal to 1.6 dl / g, especially in the range from 0.8 dl / g to 1.4 dl / g.

[0290] According to another aspect, the present invention relates to a method for preparing a 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, and shredding the used or end-of-life pipes into particles.

[0291] According to another aspect, the present invention relates to the use of the composition as defined above for the preparation of articles obtained by molding.

[0292] 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 molding the composition as defined above.

[0293] It should be understood that all the previously described embodiments are equally applicable to "molded" compositions or compositions characterized only by their viscosity, i.e., compositions having an intrinsic viscosity less than or equal to 1.6 dl / g, notably from 0.8 dl / g to 1.4 dl / g, preferably from 1 dl / g to 1.4 dl / g, preferably less than or equal to 1.4 dl / g, as measured in m-cresol at 20 °C according to ISO 307:2007. Description of the Drawings

[0294] Figure 1 Presents the odor field® of Jean-Noel Jaubert.

[0295] Figure 1 The meanings of the abbreviations used are shown in Table 1.

[0296] Figure 2

[0297] Figure 2 Shows the setup for performing the laser welding described in Table 2.

[0298] [Table 1]

[0299] Examples

[0300] The present invention will now be described in more detail by the following examples, which are not limiting.

[0301] The various compositions for preparing the plates of the present invention are as follows:

[0302] Original PA11 = PA11 with Mn 28000 g / mol + 1% heat stabilizer (consisting of 0.7% Lowinox® 44B25 phenol from Great Lakes and 0.3% Irgafos® 168 phosphite from Ciba).

[0303] Original PA11 = PA12 with Mn 26000 g / mol + 1% heat stabilizer (composed of 0.7% Lowinox® 44B25 phenol from Great Lakes and 0.3% Irgafos® 168 phosphite from Ciba).

[0304] ​​​Recy. PA11 1 = A composition consisting of 100% of the original PA11 as described above, derived from an offshore pipeline 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 asphalt.

[0305] Recy. PA11 2 = A composition consisting of 100% of the original PA11 as described above, derived from an offshore pipeline 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.

[0306] Recy. PA11 3 = A composition consisting of 50% of the original PA11 as described above, derived from an offshore pipeline 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. 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.

[0307] Recy. PA11 4 = A composition consisting of 45% of the original PA11 as described above, derived from particles shredded to a size range of 0.5 mm to 25 mm, then washed with methanol by reprecipitation dissolution, and then compounded with 4.5% of the original PA11, 50% of E-glass fibers with a circular cross-section supplied by Lanxess, and 0.5% of an antioxidant (consisting of 0.35% of Lowinox® 44B25 phenol from Great Lakes Corporation and 0.15% of Irgafos® 168 phosphite from Ciba Corporation). The composition contains 3 ppm of isooctane, 1.5 ppm of methylcyclohexane, 8 ppm of xylene, 25 ppm of 2-methylnaphthalene, and 10 ppm of phenanthrene.

[0308] Recy. PA12 5 = a composition consisting of 70% of virgin PA12 as described above, originating from an offshore pipeline, chopped to particles ranging in size from 0.5 mm to 25 mm, then washed with methanol by reprecipitation dissolution, then compounded with 20% virgin PA12, 9.5% Orevac® IM800 impact modifier sold by SK FP, 0.5% antioxidant consisting of 0.35% Lowinox® 44B25 phenol from Great Lakes, 0.15% Irgafos® 168 phosphite from Ciba. The composition contained 3 ppm isooctane, 24 ppm stearic acid, 5 ppm 4-methylbenzoic acid, 22 ppm 2-methylnaphthalene and 33 ppm phenanthrene.

[0309] The Recy. PA11 3 composition, the Recy. PA11 4 composition and the Recy. PA12 5 composition were prepared by conventional compounding in a Coperion® 40 co-rotating twin-screw extruder at 70 kg / h, at 300 rpm, at 270°C.

[0310] The composition was then molded on an injection molding press (Engel) with a nominal feed temperature of 240°C, a nominal nozzle temperature of 260°C, and a mold temperature of 60°C in a 100 × 100 × 1 mm 3 Plate format for permeation measurements. Manufactured to measure 50 × 50 × 2 mm 3 The plates were used for laser welding tests.

[0311] The injection molded panels described above were then evaluated according to several criteria:

[0312] The results are shown in Table 2.

[0313] [Table 2]

[0314]

[0315] Exudation is manifested by the appearance of deposits on the surface and is assessed visually.

[0316] Plates were rated from 1 (little exudation) to 5 (significant exudation) by trained personnel.

[0317] The samples used for welding tests were taken from 50 × 50 × 2 mm 3 Injection molded parts 40 × 10 × 2mm 3 Test specimens. Use a pneumatic press and punch to cut the specimens. Materials CE2, CE3, CE4, CE5, IE1 and IE2 will be welded to reference material CE2. Materials CE1 and IE3 will be welded to reference material CE1.

[0318] Welding was carried out using an LPKF Inlineweld 6200 machine (Garben, Germany) with a spot diameter of 2.1 mm and a clamping force of 700 N. Infrared radiation was generated using a laser diode with a wavelength of 980 nm. For each sample, the laser power was 110 W and the welding speed was 1000 mm / s.

[0319] According to the standard ASTM D3164 - 03, the quality of the weld was defined by mechanical testing of the two welded components. The shear stress shown in Table 2 was measured in this way.

[0320] The composition of the present invention has an optimal compromise between exudation and shear stress. In particular, the shear stress of the composition of the present invention is higher than that of the comparative compositions CE1 and CE2, and the exudation of the composition of the present invention is lower than that of the comparative composition CE3.

Claims

1. A molding composition comprising, by weight: a) 35% to 100%, in particular 35% to 91.9%, 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 and shredding of the pipeline into granules; b) 0 to 65%, in particular 5 to 50%, 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%.

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

4. The molding composition according to any one of claims 1 to 3, characterized in that, 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.

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

6. The molding composition according to any one of claims 1 to 5, characterized in that, The recycled semi-crystalline aliphatic polyamide PA2 contains 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 molding composition according to any one of claims 3 to 6, characterized in that, The mass content of the substances present in the recycled semi-crystalline aliphatic polyamide PA2 is 100 ppm to 2000 ppm, in particular 100 ppm to 1000 ppm.

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

9. The molding composition according to any one of claims 1 to 8, characterized in that, The recycled semi-crystalline aliphatic polyamide PA2 has functional groups resulting from the pyrolysis reaction in an acidic medium, in particular amide functional groups and / or the alpha-methylene of said amide functional groups and acid chain ends, which are selected from nitrile, ketone and ester functional groups resulting from 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 relative to the amide functional groups is higher than that of the same polyamide constituting the unused pipe.

10. The molding 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 molding 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, said cyclic oligomers being selected from oligomers having a molar mass of less than 1000 g / mol.

12. The molding 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, said alkyl being C1 to C18, and said content is higher than that of the virgin semi-crystalline aliphatic polyamide.

13. A process for preparing a recycled semi-crystalline aliphatic polyamide as defined in any one of claims 1 to 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 pipes from an offshore or onshore oil or gas deposit, in particular an offshore deposit, and shredding the used or end-of-life pipes 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 injection moulding.

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

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