BLOW MOLDING COMPOSITION BASED ON BRANCHED POLYAMIDE AND USE THEREOF - Patent application

Abstract

The present invention relates to a composition for blow molding or extrusion, in particular for blow molding, comprising a) 88 to 99.95% by weight, more particularly 89 to 99.9% by weight, in particular 93 to 99.9% by weight, of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of 7 or more, more particularly 8 or more, b) 0.05% to 10% by weight, more particularly 0.1% to 9% by weight, in particular 0.1% to 5% by weight, of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0 to 2% by weight, more particularly 0.1 to 2% by weight, of at least one additive Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to ISO standard 6721-10:2015 at a temperature of 250°C, a frequency of 0.292 rad / s and a deformation of 2%, The sum of components a) + b) + c) equals 100% by weight, It relates to compositions for blow molding or extrusion, especially blow molding.

Description

[Technical field]

[0001] The present invention relates to compositions for blow moulding or extrusion, in particular for blow moulding, based on branched polyamides, as well as their use for the preparation of single- or multi-layer tubular structures intended for the transport, distribution or storage of hydrogen, and to a process for the preparation of said structures. [Background technology]

[0002] One of the objectives pursued in the automotive sector is to propose less polluting vehicles. Electric or hybrid vehicles equipped with batteries are therefore intended to gradually replace combustion engine vehicles such as gasoline or diesel vehicles. It can be seen here that the battery is a relatively complex component of the vehicle. Depending on the location of the battery in the vehicle, it may be necessary to protect it from impacts and the external environment, which may be of extreme temperature and variable humidity. It is also necessary to avoid the risk of fire.

[0003] Furthermore, in order not to damage the battery cells and to maintain its lifespan, it is important that its operating temperature does not exceed 55° C. Conversely, in winter, for example, it may be necessary to increase the temperature of the battery to optimize its operation.

[0004] Furthermore, electric vehicles still suffer from several problems today, such as battery range, the use of rare earth elements in these batteries, which are not exhaustible resources, and the problem of electricity production in different countries to be able to recharge the batteries.

[0005] Hydrogen is therefore an alternative to electric batteries, as it can be converted into electricity by fuel cells and thus power electric vehicles.

[0006] Nevertheless, the storage of hydrogen is technically challenging and expensive, especially when mobile storage is involved, due to its very low molar mass and its very low liquefaction temperature. However, to be effective, the storage must be small, which makes it necessary to keep the hydrogen under high pressure, taking into account the temperatures at which the vehicles will be used. This is more particularly the case for fuel cell hybrid road vehicles, where a range of around 600-700 km is desired, or even less, for essentially urban applications complementing a battery electric base.

[0007] A hydrogen tank generally consists of a metal casing (liner) that must prevent hydrogen permeation. This first casing must itself be protected by a second casing (generally made of composite materials) intended to withstand the internal pressure of the tank (e.g. 700 bar) and to withstand possible shocks or heat sources. The valve system must also be safe.

[0008] EP 0 495 363 A1 relates to polyamide compositions based on polyamide (PA) alloys and special olefinic anhydride copolymers, and their use for producing molded hollow bodies.

[0009] Nevertheless, the exemplified compositions are too fluid to be extruded into large tanks.

[0010] These structures are also based on polyamide 6 (PA6), which has poor resistance to zinc chloride and is brittle at low temperatures, and is therefore not suitable for use in tanks for automotive fluids such as hydrogen.

[0011] WO20027031 relates to a composition based on polyamide 6 (PA6), an impact modifier and a metal halide.

[0012] As mentioned above, these constructions are based on PA6 (which has poor resistance to zinc chloride and is brittle at low temperatures) and are therefore not suitable for use in tanks for automotive fluids such as hydrogen.

[0013] FR 2 996 556 A1 relates to liners for the storage of gases, in particular compressed natural gas (CNG), methane or hydrogen, which comprise a composition based on a branched polyamide and an impact modifier.

[0014] The compositions exemplified are based on PA6 and therefore suffer from the same problems as above. Moreover, they contain too many impact modifiers, which creates a risk of cavitation (blistering).

[0015] Chinese Patent No. 3101967 relates to polyamide compositions for blow molding based on PA6 and impact modifiers, so that they have the same problems as above.

[0016] EP 1 352 934 A describes metal surfaces coated with a polyamide-based layer consisting of a mixture of polyamide and polyolefin functionalized with an unsaturated carboxylic acid anhydride.

[0017] US Patent Application Publication No. 2005 / 228145 describes a transparent multi-layer structure that includes a first polyamide layer that consists of a mixture of a polyamide functionalized with maleic anhydride and a polyolefin.

[0018] French Patent Application FR 3 078 132 describes a flexible tubular structure comprising a layer comprising a mixture of polyamide and polyolefin functionalized with anhydrides.

[0019] EP 2 649 130 A1 describes a gas storage liner comprising a composition comprising a mixture of a polyamide and an anhydride-functionalized polyolefin. Summary of the Invention

[0020] It is therefore necessary to provide a composition which overcomes the above problems, and therefore the present invention relates to a composition for blow moulding or extrusion, in particular for blow moulding, comprising: a) 88 to 99.95% by weight, more particularly 89 to 99.9% by weight, in particular 93 to 99.9% by weight, of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of 7 or more, more particularly 8 or more, b) 0.05% to 10% by weight, more particularly 0.1% to 9% by weight, in particular 0.1% to 5% by weight, of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0 to 2% by weight, more particularly 0.1 to 2% by weight, of at least one additive Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2%, The sum of components a) + b) + c) equals 100% by weight, It relates to compositions for blow molding or extrusion, especially blow molding.

[0021] Thus, the inventors have unexpectedly found that the use of certain semi-crystalline aliphatic polyamides with or without a certain range of branching agents and additives makes it possible to obtain compositions having melt viscosities within a range that, after compounding, allows for extrusion blow molding or extrusion, more particularly extrusion blow molding, for the construction of single or multi-layer tubular structures intended for the transport, distribution or storage of hydrogen.

[0022] Another advantage of the compositions of the present invention is their good dimensional stability, i.e. low water absorption and good resistance to zinc chloride.

[0023] The term "single- or multi-layer tubular structure" is understood to mean a tank comprising or consisting of one or more layers.

[0024] A single layer or multi-layer structure in the present invention also refers to a pipe or tube for transporting hydrogen to or from a tank to a fuel cell, comprising or consisting of one or more layers.

[0025] In one embodiment, non-functionalized impact modifiers are excluded from the composition.

[0026] In another embodiment, non-functionalized and minimally functionalized impact modifiers are excluded from the composition.

[0027] The term "scarcely functionalized impact modifier" is understood to mean an impact modifier having an equivalent weight per reactive functional group of greater than 10 000 g / mol, advantageously greater than 6000 g / mol.

[0028] In yet another embodiment, functionalized or non-functionalized impact modifiers are excluded from the composition.

[0029] In yet another embodiment, non-functionalized elastomers are excluded from the composition.

[0030] In yet another embodiment, plasticizers are excluded from the composition.

[0031] Optionally Excluded Impact Modifiers The expression "impact modifier" should be understood to mean a polymer with a modulus lower than that of the resin, which exhibits good adhesion with the matrix so as to dissipate the energy of the impact.

[0032] The impact modifier is advantageously constituted by a polymer, in particular a polyolefin, having a flexural modulus of less than 100 MPa, measured according to ISO standard 178, and a Tg (measured according to standard 11357-2 at the inflection point of the DSC thermogram) of less than 0° C.

[0033] The polyolefins of the impact modifier may be functionalized or unfunctionalized, or may be a mixture of at least one functionalized and / or at least one unfunctionalized. For simplicity, the polyolefins are designated as (B) and functionalized polyolefins (B1) and unfunctionalized polyolefins (B2) are described below.

[0034] The non-functionalized polyolefins (B2) are conventionally homopolymers or copolymers of alpha-olefins or diolefins, such as, for example, ethylene, propylene, 1-butene, 1-octene, butadiene, etc. By way of example, mention may be made of: - 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 / alpha-olefin copolymers such as ethylene / propylene, EPR (short for ethylene-propylene-rubber) and ethylene / propylene / diene (EPDM) copolymers. -Styrene / Ethylene-Butene / Styrene Block Copolymer (SEBS), Styrene / Butadiene / Styrene Block Copolymer (SBS), Styrene / Isoprene / Styrene Block Copolymer (SIS), Styrene / Ethylene-Propylene / Styrene Block Copolymer (SEPS). - 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), the proportion of comonomers being capable of reaching 40% by weight.

[0035] The functionalized polyolefins (B1) may be polymers of alpha-olefins having reactive units (functional groups), such as acid, anhydride or epoxy functional groups. By way of example, mention may be made of the aforementioned polyolefins (B2) grafted or copolymerized or tripolymerized 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 fully or partially neutralized with metals, such as Zn), or with carboxylic anhydrides, such as maleic anhydride. The functionalized polyolefins are, for example, PE / EPR mixtures, the weight ratio of which can vary widely, for example from 40 / 60 to 90 / 10, which mixtures are cografted with anhydrides, in particular maleic anhydride, according to a degree of grafting of, for example, 0.01 to 5% by weight, advantageously 2.8 to 5% by weight.

[0036] The functionalized polyolefins (B1) may be chosen from the following (co)polymers grafted with maleic anhydride or with glycidyl methacrylate, the degree of grafting being, for example, between 0.01% and 5% by weight: PE, PP, copolymers of ethylene with propylene, butene, hexene or octene, for example containing from 35% to 80% by weight of ethylene; - Ethylene / alpha-olefin copolymers such as ethylene / propylene, EPR (short for ethylene-propylene-rubber) and ethylene / propylene / diene (EPDM) copolymers. -Styrene / Ethylene-Butene / Styrene Block Copolymer (SEBS), Styrene / Butadiene / Styrene Block Copolymer (SBS), Styrene / Isoprene / Styrene Block Copolymer (SIS), Styrene / Ethylene-Propylene / Styrene Block Copolymer (SEPS). - copolymers of ethylene and vinyl acetate (EVA) containing up to 40% by weight of vinyl acetate; - copolymers of ethylene and alkyl (meth)acrylates containing up to 40% by weight of alkyl (meth)acrylates; - Copolymers of ethylene, vinyl acetate (EVA) and alkyl (meth)acrylates containing up to 40% by weight of comonomer.

[0037] The functionalized polyolefin (B1) can also be selected from ethylene / propylene copolymers, with a predominance in propylene, grafted with maleic anhydride and then condensed with monoaminated polyamides (or polyamide oligomers) (products described in EP-A-0 342 066).

[0038] The functionalized polyolefin (B1) may be a copolymer or terpolymer of at least the following units: (1) ethylene, (2) an alkyl (meth)acrylate or a saturated carboxylic acid vinyl ester, and (3) an anhydride, such as maleic anhydride or (meth)acrylic anhydride, or an epoxy, such as glycidyl (meth)acrylate.

[0039] As examples of the latter type of functionalized polyolefins, the following copolymers may be mentioned, in which ethylene preferably represents at least 60% by weight and the termonomers (functional groups) represent, for example, from 0.1 to 13% by weight of the copolymer: - 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.

[0040] In the above copolymers, the (meth)acrylic acid can be salified with Zn or Li.

[0041] The term "alkyl (meth)acrylate" in (B1) or (B2) denotes 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.

[0042] Furthermore, said polyolefins (B1) may also be crosslinked by any suitable method or agent (diepoxy, diacid, peroxide, etc.), and the term functionalized polyolefin also includes mixtures of the above-mentioned polyolefins with difunctional agents such as diacids, dianhydrides, diepoxy, etc. capable of reacting with these polyolefins, or mixtures of at least two functionalized polyolefins capable of reacting with each other.

[0043] The copolymers (B1) and (B2) can be copolymerized randomly or in a block manner and exhibit a linear or branched structure.

[0044] The molecular weight, MFI index and density of these polyolefins can also vary within wide ranges that will be appreciated by those skilled in the art. MFI is an abbreviation for Melt Flow Index. It is measured according to ASTM standard 1238 or ISO standard 1133:2011.

[0045] The non-functionalized polyolefin (B2) is advantageously chosen from polypropylene homopolymers or copolymers and any ethylene homopolymers or copolymers of ethylene and comonomers 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.

[0046] Advantageously, the functionalized polyolefin (B1) is selected from any polymer containing alpha-olefin units and units with polar reactive functional groups, such as epoxy, carboxylic acid or carboxylic anhydride functional groups. Examples of such polymers include terpolymers of ethylene, alkyl acrylate and maleic anhydride or glycidyl methacrylate, such as Lotader® from SK global chemical, or polyolefins grafted with maleic anhydride, such as Orevac® from SK global chemical, as well as terpolymers of ethylene, alkyl acrylate and (meth)acrylic acid. Polypropylene homopolymers or copolymers grafted with carboxylic anhydrides and then condensed with polyamides or monoamine oligomers of polyamides may also be mentioned.

[0047] Semi-Crystalline Aliphatic Polyamide The composition for blow molding or extrusion, in particular for blow molding, comprises 88 to 99.95%, more particularly 89 to 99.8%, of at least one semi-crystalline aliphatic polyamide having a carbon number per nitrogen atom of 7 or more, more particularly 8 or more.

[0048] The nomenclature used to define polyamides is described in ISO standard 1874-1:2011 "Plastics - Polyamide (PA) molding and extrusion materials - Part 1: Nomenclature", in particular page 3 (Tables 1 and 2), and is well known to those skilled in the art.

[0049] The polyamide may be a homopolyamide or a copolyamide or a mixture thereof.

[0050] For the purposes of the present invention, the term "semi-crystalline" denotes a (co)polyamide having a melting point (Tm) in DSC according to standard ISO 11357-3:2013 and a crystallization enthalpy during the cooling step at a rate of 20 K / min in DSC, measured according to standard ISO 11357-3 of 2013, greater than 20 J / g, preferably greater than 30 J / g.

[0051] The semi-crystalline aliphatic polyamide comprises at least one C9 to C18 amino acid, preferably a C10 to C18 amino acid, more preferably a C10 to C12 amino acid, or at least one C9-C18 lactam, preferably a C10-C18 lactam, more preferably a C10-C12 lactam, or At least one C4 to C36, preferably C6 to C18, preferably C6 to C12, more preferably C10 to C12 diamine Ca and at least one C4 to C36, preferably C6 to C18, preferably C6 to C12, more preferably C10 to C12 dicarboxylic acid Cb, or mixtures thereof is derived from a repeating unit obtained by polycondensation of With the proviso that the number of carbon atoms per nitrogen atom in the repeating unit is at least 7, in particular at least 8.

[0052] C9-C18 amino acids are in particular 9-aminononanoic acid, 10-aminodecanoic acid, 10-aminoundecanoic acid, 12-aminododecanoic acid and 11-aminoundecanoic acid and derivatives thereof, in particular N-heptyl-11-aminoundecanoic acid.

[0053] The C9-C18 lactam is in particular lauryllactam.

[0054] The at least one C4-C36 diamine Ca 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 derived from fatty acids.

[0055] Advantageously, the at least one diamine Ca is C6 to C18 and is chosen from 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.

[0056] The at least one C4 to C36 dicarboxylic acid Cb may be selected from succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, octadecenediamine, eicosanediamine, docosanediamine, and diamines derived from fatty acids.

[0057] Advantageously, the at least one dicarboxylic acid Cb is C6 to C18 and is chosen from adipic acid, suberic acid, azelaic acid, sebacic acid and undecanedioic acid, dodecanedioic acid, brassylic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid.

[0058] In one embodiment, the semi-crystalline aliphatic polyamide is selected from PA610, PA612, PA614, PA10, PA11 and PA12, in particular PA610, PA612 and PA11.

[0059] In one embodiment, the semi-crystalline aliphatic polyamide is a mixture of two semi-crystalline aliphatic polyamides in a weight ratio range of 5 / 95 to 95 / 5, having a carbon number per nitrogen atom of 7 or more, more particularly 8 or more.

[0060] Advantageously, the polyamide has an amine chain end concentration of between 5 and 60 μeq / g, very advantageously between 10 and 50 μeq / g.

[0061] Advantageously, the polyamide has an acid chain end concentration of between 5 and 60 μeq / g, very advantageously between 10 and 50 μeq / g.

[0062] Amine chain ends are measured according to the following method: A polyamide sample is dissolved in meta-cresol. The sample is then assayed potentiometrically with a 0.02N perchloric acid solution.

[0063] Acid chain ends are measured according to the following method: A sample of the polyamide is dissolved in benzyl alcohol. The sample is then assayed potentiometrically with a 0.02N solution of tetrabutylammonium hydroxide.

[0064] In one embodiment, the polyamide or polyamide blend has an MFI of 0.01 to 10 at 235° C. and 5 kg, advantageously 0.01 to 5 g / 10 min.

[0065] The polyamide according to the invention has an intrinsic viscosity in m-cresol, determined according to ISO standard 307:2007, but using m-cresol instead of sulfuric acid, of greater than 1.45, advantageously greater than 1.55 and very advantageously greater than 1.6 at a temperature of 20° C. and a concentration of 0.5% by weight.

[0066] Branching Agent The branching agents are present in the composition at from 0.05% to 10%, more particularly from 0.1% to 9%, in particular from 0.1% to 5% by weight, and are selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides.

[0067] In one embodiment, the branching agent is present in the composition at 0.1 to 2% by weight.

[0068] The branching agent may be the impact modifier, especially a functionalized polyolefin, or may be different from the impact modifier.

[0069] Advantageously, it is different from the impact modifier, i.e. it has a Tg above -30°C, very advantageously above 0°C.

[0070] Advantageously, the equivalent weight per reactive functional group of the branching agent is between 100 and 10000 g / mol, advantageously between 120 and 6000 g / mol, more advantageously between 140 and 3300 g / mol.

[0071] In one embodiment, the branching agent has an average functionality between 1.8 and 200, preferably between 2.1 and 150, with respect to epoxy, anhydride or isocyanate functional groups.

[0072] In yet another embodiment, the molar mass of the branching agent is between 300 and 120000 g / mol, preferably between 400 and 100000 g / mol.

[0073] The molar mass is determined by gas chromatography (GC).

[0074] The equivalent weight per reactive functional group of the branching agent is determined as follows. Isocyanate: Equivalent weight per isocyanate functional group is measured according to the AFNOR standard referenced in NFT52-132.

[0075] Epoxide: Equivalent weight per epoxide functional group is measured according to ASTM standard D1652-11(2019).

[0076] Maleic anhydride: The mass content of maleic anhydride is determined by FTIR according to the method of De Roovers et al. [J Polym Sci, Part A: Polym Chem 1995; 33: 829].

[0077] Equivalent weights are often given by suppliers in TDS.

[0078] The average functionality is calculated by dividing the molar mass determined by GC by the average equivalent weight.

[0079] The polyepoxide may be a copolymer made from glycidyl maleic anhydride (GMA) or any other monomer that contains epoxy functionality.

[0080] Examples of commercially available polyepoxides are, for example, Xibond® 920 sold by Polyscope, or Joncryl® ADR4400 sold by BASF, or Lotader® AX8900 sold by SK Chemical.

[0081] The polyanhydrides may be copolymers containing copolymerized or grafted anhydrides such as maleic anhydride or itaconic anhydride.

[0082] In particular, the polyanhydride is polymaleic anhydride.

[0083] The other monomers in the copolymer, including the copolymerized anhydride, may be vinyl aromatic monomers such as styrene or styrenes in which the aromatic ring contains halogen or alkyl substituents.

[0084] In one embodiment, the other monomer of the copolymer containing the copolymerized anhydride can be a vinyl monomer, such as ethylene or octadecene.

[0085] In particular, polymaleic anhydride is a copolymer of styrene and maleic anhydride.

[0086] Examples of commercially available polymaleic anhydrides are, for example, Xibond® 125 (a copolymer of styrene and maleic anhydride) sold by Polyscope, or Orevac IM 800 sold by SK Chemicals, or PA18 (a copolymer of 1-octadecene and maleic anhydride) sold by Chevron Phillips Chemical Company.

[0087] The polyisocyanates are preferably oligomers of isocyanates such as isocyanurates or allophanates.

[0088] An example of a commercially available polyisocyanate is, for example, Desmodur 3300 sold by Covestro.

[0089] Additives The additives may be present in an amount of up to 2% by weight relative to the total weight of the composition, and in particular are present in an amount of from 0.1% to 2% by weight relative to the total weight of the composition.

[0090] The additives may be selected from catalysts, antioxidants, heat stabilizers, UV stabilizers, light stabilizers, lubricants, flame retardants, nucleating agents, chain extenders and dyes.

[0091] In one embodiment, the additives are selected from catalysts, antioxidants, heat stabilizers, UV stabilizers, light stabilizers, lubricants, flame retardants, chain extenders, and dyes.

[0092] The term "catalyst" refers to a polycondensation catalyst such as a mineral or organic acid.

[0093] Advantageously, the proportion by weight of catalyst is between about 50 ppm and about 5000 ppm, and in particular between about 100 and about 3300 ppm, relative to the total weight of the composition.

[0094] Advantageously, the catalyst is chosen from phosphoric acid (H3PO4), phosphorous acid (H3PO3) and hypophosphorous acid (H3PO2), or mixtures thereof.

[0095] The antioxidant may in particular be an antioxidant based on a copper complex, present in an amount of 0.05% to 5% by weight, preferably 0.05% to 1% by weight, preferably 0.1% to 1% by weight.

[0096] The term "copper complex" especially refers to complexes of monovalent or divalent copper salts with organic or inorganic acids and organic ligands.

[0097] Advantageously, the copper salt is chosen from cupric (Cu(II)) salts of hydrogen halides, cuprous (Cu(I)) salts of hydrogen halides and aliphatic carboxylates.

[0098] In particular, the copper salt is selected from CuCl, CuBr, CUI, CuCN, CuCl2, Cu(OAC)2, cupric stearate.

[0099] Copper complexes are described, inter alia, in US Pat. No. 3,505,285.

[0100] The copper-based complexes also include phosphines, especially triphenylphosphine, mercaptobenzimidazole, EDTA, acetylacetonate, glycine, ethylenediamine, oxalate, diethylenediamine, triethylenetetraamine, pyridine, tetrabromobisphenyl-A, tetrabisphenyl-A derivatives, such as epoxy derivatives, and These may include chlorodimethane dibenzo(a,e)cyclooctene and mixtures thereof, diphosphone and dipyridyl or mixtures thereof, especially derivatives of triphenylphosphine and / or mercaptobenzimidazole.

[0101] Phosphine refers to an alkyl phosphine such as tributylphosphine, or an aryl phosphine such as triphenylphosphine (TPP).

[0102] Advantageously, the ligand is triphenylphosphine.

[0103] Examples of complexes and their preparation are described in Chinese Patent No. 02347258.

[0104] Advantageously, the amount of copper in the composition of the invention is between 10 ppm and 1000 ppm by weight, in particular between 20 ppm and 70 ppm, and in particular between 50 and 150 ppm, relative to the total weight of the composition.

[0105] Advantageously, the copper-based complex also includes a halogenated organic compound.

[0106] The halogenated organic compound can be any halogenated organic compound.

[0107] Advantageously, the halogenated organic compounds are brominated and / or aromatic compounds.

[0108] Advantageously, the aromatic compound is chosen in particular from decabromodiphenyl ether, decabromodiphenyl ether, bromo- or chloro-styrene oligomers and polydibromostyrene.

[0109] Advantageously, the halogenated organic compound is a bromine-based compound.

[0110] The halogenated organic compound is added to the composition in a proportion of 50 to 30000 ppm by weight, particularly 100 to 10000, and especially 500 to 1500 ppm of halogen relative to the total weight of the composition.

[0111] Advantageously, the molar ratio of copper:halogen is between 1:1 and 1:3000, in particular between 1:2 and 1:100.

[0112] In particular, the ratio is between 1:1.5 and 1:15.

[0113] Advantageously, antioxidants based on copper complexes.

[0114] The heat stabilizer may be an organic stabilizer or, more generally, a combination of organic stabilizers, such as primary antioxidants of the phenolic type (e.g., those of the irganox 245 or 1098 or 1010 types manufactured by Ciba), or secondary antioxidants of the phosphite type.

[0115] The UV stabilizer may be HALS, which stands for hindered amine light stabilizer, or an anti-UV agent (eg, Tinuvin 312 from Ciba).

[0116] The light stabilizer may be of the hindered amine type (eg Tinuvin 770 from Ciba), a phenolic stabilizer or a phosphorus-based stabilizer.

[0117] The lubricant may be a fatty acid based lubricant such as stearic acid.

[0118] The flame retardant may be a halogen-free flame retardant as described in US 2008 / 0274355, in particular a phosphorus-based flame retardant, for example a metal salt of a phosphinic acid, more particularly a dialkylphosphinic acid salt, in particular an aluminum diethylphosphinic acid salt or an aluminum diethylphosphinic acid salt, a metal salt of a diphosphinic acid, a mixture of an aluminum phosphate-based flame retardant with a nitrogen synergist, or a mixture of an aluminum phosphate-based flame retardant with a phosphorus synergist, a polymer containing at least one metal salt of phosphoric acid, in particular ammonium polyphosphate, ammonium sulfamate or ammonium pentaborate, or a melamine salt, a melamine-based salt such as melamine salt, melamine pyrophosphate and melamine cyanurate, or a cyanuric acid-based salt, or at least one metal salt of a diphosphinic acid or red phosphorus, a metal borate such as antimony oxide, zinc oxide, iron oxide, magnesium oxide, or zinc borate, or a phosphazene, phospham, or phosphooxynitride, or a mixture thereof. They may also be halogenated flame retardants such as brominated or polybrominated polystyrene, brominated polycarbonate or brominated phenols.

[0119] The nucleating agent may be silica, alumina, clay or talc, especially talc.

[0120] Examples of suitable chain regulators are monoamines, monocarboxylic acids, diamines, triamines, dicarboxylic acids, tricarboxylic acids, tetraamines, tetracarboxylic acids and also oligoamines or oligocarboxylic acids, in each case having 5 to 8 amino or carboxyl groups, respectively, in particular dicarboxylic acids, tricarboxylic acids or mixtures of dicarboxylic and tricarboxylic acids. By way of example, it is possible to use dodecanedicarboxylic acid in the dicarboxylic acid form and trimellitic acid as tricarboxylic acid.

[0121] composition Throughout this specification, all percentages are given by weight.

[0122] A composition for blow molding or extrusion, in particular for blow molding, comprising a) 88 to 99.95% by weight, more particularly 89 to 99.9% by weight, in particular 93 to 99.9% by weight, of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of 7 or more, more particularly 8 or more, b) 0.05% to 10% by weight, more particularly 0.1% to 9% by weight, in particular 0.1% to 5% by weight, of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0 to 2% by weight, more particularly 0.1 to 2% by weight, of at least one additive Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2%, The sum of components a) + b) + c) equals 100% by weight, A composition for blow moulding or extrusion, especially blow moulding.

[0123] In one embodiment there is provided a composition for blow molding or extrusion, in particular blow molding, comprising: a) 88 to 99.95% by weight, more particularly 89 to 99.9% by weight, in particular 93 to 99.9% by weight, of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of 7 or more, more particularly 8 or more, b) 0.05% to 10% by weight, more particularly 0.1% to 9% by weight, in particular 0.1% to 5% by weight, of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0 to 2% by weight, more particularly 0.1 to 2% by weight, of at least one additive It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2%, The sum of components a) + b) + c) equals 100% by weight, A composition for blow moulding or extrusion, especially blow moulding.

[0124] In one embodiment, the composition comprises: a) 88 to 99.95% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.05% to 10% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides. Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a)+b) equals 100% by weight.

[0125] Advantageously, in this embodiment, the composition comprises: a) 88 to 99.95% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.05% to 10% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides. It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a)+b) equals 100% by weight.

[0126] In another embodiment, the composition comprises: a) 88 to 99.85% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.05% to 10% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0.1 to 2 wt. % of at least one additive; Including, The composition, after compounding, has a melt viscosity of 10,000 to 300,000 Pa.s, preferably 15,000 to 220,000 Pa.s, measured in plane-plane geometry at a temperature of 250° C., a frequency of 0.292 rad / s and a deformation of 2% by weight; The sum of components a) + b) + c) equals 100% by weight.

[0127] Advantageously, in this embodiment, the composition comprises: a) 88 to 99.85% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.05% to 10% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0.1 to 2 wt. % of at least one additive; It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0128] In a first variant, the composition comprises a) 89 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1 to 9% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0 to 2% by weight, more particularly 0.1 to 2% by weight, of at least one additive Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0129] In one embodiment of this first variant, the composition comprises: a) 89 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 9% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides. Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a)+b) equals 100% by weight.

[0130] Advantageously, in this embodiment of this first variant, the composition comprises: a) 89 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 9% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides. It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a)+b) equals 100% by weight.

[0131] In another embodiment of this first variant, the composition comprises: a) 89 to 99.8% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 9% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0.1 to 2 wt. % of at least one additive; It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0132] Advantageously, in another embodiment of this first variant, the composition comprises: a) 89 to 99.8% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 9% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0.1 to 2 wt. % of at least one additive; It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0133] In a second variant, the composition comprises: a) 93 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1 to 5% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0 to 2% by weight, more particularly 0.1 to 2% by weight, of at least one additive Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0134] In one embodiment of this second variant, the composition comprises: a) 93 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 5% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides. Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a)+b) equals 100% by weight.

[0135] Advantageously, in this embodiment of this second variant, the composition comprises: a) 93 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 5% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides. It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in planar geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a)+b) equals 100% by weight.

[0136] In another embodiment of this second variant, the composition comprises: a) 93 to 99.8% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 5% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0.1 to 2 wt. % of at least one additive; It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0137] Advantageously, in another embodiment of this second variant, the composition comprises: a) 93 to 99.8% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 5% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0.1 to 2 wt. % of at least one additive; It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0138] In a third variant, the composition comprises: a) 98 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1 to 2% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0 to 2% by weight, more particularly 0.1 to 2% by weight, of at least one additive Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0139] In one embodiment of this third variant, the composition comprises: a) 98 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 2% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides. Including, The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a)+b) equals 100% by weight.

[0140] Advantageously, in this embodiment of this third variant, the composition comprises: a) 98 to 99.9% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 2% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides. It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2 wt. %, The sum of components a)+b) equals 100% by weight.

[0141] In another embodiment of this third variant, the composition comprises: a) 96 to 99.8% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 2% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0.1 to 2 wt. % of at least one additive; It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0142] Advantageously, in another embodiment of this third variant, the composition comprises: a) 96 to 99.8% by weight of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of ≥ 7, more particularly ≥ 8, b) 0.1% to 2% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydrides and polyepoxides, c) 0.1 to 2 wt. % of at least one additive; It consists of: The composition, after compounding, has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to standard ISO 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2% by weight, The sum of components a) + b) + c) equals 100% by weight.

[0143] In all variants and embodiments of the above compositions: The MVR (Volumetric Flow Rate) determined according to ISO1133:2011 at a weight of 21.6 kg and a temperature of 275°C is 2 to 25 cm 3 / 10 minutes, advantageously 5-20cm 3 / 10 min, very advantageously 6-18 cm 3 / 10 minutes.

[0144] In all variants and embodiments of the above compositions: The MFI of the composition is 0-5, advantageously 0-0.1 g / 10 min at 235° C. and 1 kg according to ISO 1133:2011.

[0145] The branching agent and the polyamide are linked by a covalent bond, preferably the branching agent and the polyamide are linked by an amide, ester or urea functional group.

[0146] Advantageously, at least 5% by weight, very advantageously at least 15% by weight, of the polyamide is covalently bonded to the branching agent, 0.292rad.s of the composition -1 / 292rad.s -1The ratio of the melt viscosities measured in a plane-plane geometry at 0.292 rad.s to 100 is between 10 and 200, advantageously between 25 and 150. This ratio makes it possible to determine the degree of branching of the polyamide of the composition. The higher the ratio, the more branched the polyamide is in the composition. As a result, the polyamide has a melt viscosity of 0.292 rad.s -1 and fluid, 0.292rad.s -1 It must be viscous at 292rad.s -1 The viscosity at is 400 to 2000, preferably 600 to 1550, The Rheotens force of the compounded composition at 250° C. is between 22 mN and 200 mN, more particularly between 25 mN and 150 mN, which determines the melt strength of the polyamide; the higher the force, the less the polyamide flows.

[0147] The Rheotens force can be determined, for example, using a Rheotens 71.97 instrument from Gottfert. The Rheotens instrument is an apparatus equipped with a notched wheel that allows pulling a ring at the exit of a Rheotester 2000 capillary rheometer from Gottfert: capillary with L / D = 30 and D = 1 mm at a temperature of 250 °C, shearing in a 100 s-1 die, distance between the exit of the ring and the axis of the notched wheel of 105 mm, acceleration of the wheel of 2.4 mm / s -2 The swelling index of the composition at the extruder exit after compounding is greater than 1.15, preferably greater than 1.2. The swelling index is achieved according to the following procedure. An extrusion blowline equipped with an accumulator is used to extrude a tubular parison of 25 cm. The discharge speed is set at 0.1 m / s and the temperature of the extrudate is checked manually with a temperature probe. The diameter of the parison is measured at a die of less than 10 cm. Five measurements are taken to obtain an average value. The temperature is chosen as a function of the flow properties of the polymer in order to limit as much as possible the creep of the parison.

[0148] The strength of the parison makes it possible to analyze the ability of the material to counteract the effects of gravity. Under its weight, a horizontally or vertically extruded parison creeps and therefore changes its dimensions. The resistance of the vertical parison of the composition after compounding is between 15 and 50 seconds, in particular between 20 and 45 seconds. These measurements were carried out as follows: A parison weighing 1.2 kg and with a length of 190 mm is extruded with an exit speed set at 0.1 m / s. The time it takes for the parison's length to increase by 40% due to creep is measured. Longer times represent a viscous material. The temperature is chosen as a function of the flow properties of the polymer in order to limit the creep of the parison as much as possible.

[0149] Decompression tests under hydrogen have shown that if the amount of impact modifier in the composition of the material is less than 10% by mass, it is possible to avoid and limit the cavitation (blister) mechanism. The samples are subjected to a pressure increase from 1 to 40 MPa at a rate of 1 MPa.min-1 and the pressure is maintained at 40 MPa for 7 days to reach the saturated state. The decompression stage is carried out at a rate of 5 MPa.min-1. The samples are observed under a scanning electron microscope to observe cavitation.

[0150] The compositions according to the invention survive reduced pressure testing under hydrogen.

[0151] According to a second aspect, the invention relates to a single- or multi-layer tubular structure intended for the transport, distribution or storage of hydrogen, comprising at least one sealing layer (1) comprising the composition defined above.

[0152] In one embodiment of this second aspect, the structure is intended for transporting hydrogen, and the sealing layer has a total percentage of contaminants present in hydrogen and extracted from the sealing layer after contact with hydrogen of 3% or less by weight, more particularly less than 2% by weight, of the sum of the components of the composition of the sealing layer, the total percentage of contaminants being determined according to the contaminant test defined in CSA / ANSI standard CHMC2:19.

[0153] The sealing layer is therefore in contact with hydrogen.

[0154] In another embodiment of this second aspect, the structure further comprises at least one composite reinforcing layer (2), the innermost composite reinforcing layer being either welded or unwelded to the outermost adjacent sealing layer.

[0155] Thus, the composite reinforcement layer is above the sealing layer in contact with hydrogen.

[0156] The number of composite reinforcing layers is 1 to m.

[0157] The composite reinforcing layer may consist of a fibrous material in the form of continuous fibers impregnated with a composition comprising mainly at least one polymer P2j, j=1 to m, where m is the number of reinforcing layers, in particular an epoxy or epoxy-based resin or a resin based on polyisocyanates, in particular polyisocyanurates. Polymer P2j: and The polymer P2j may be thermoplastic or thermosetting.

[0158] Thermoplastic polymer P2j: The term "thermoplastic" or "thermoplastic polymer" is understood to mean a material which is generally solid at room temperature, which may be semi-crystalline or amorphous, in particular semi-crystalline, which softens upon increasing temperature, in particular after passing its glass transition temperature (Tg), which, if amorphous, may flow at higher temperatures, or which, if semi-crystalline, may show a distinct melting when passing its so-called melting temperature (Tm), and which becomes solid again upon decreasing temperature below the crystallization temperature Tc (if semi-crystalline) and below its glass transition temperature (if amorphous).

[0159] Tg, Tc and Tm are determined by differential scanning calorimetry (DSC) according to standards 11357-2:2013 and 11357-3:2013, respectively.

[0160] The number average molecular weight Mn of the thermoplastic polymer is preferably in the range of 10 000 to 40 000, preferably 10 000 to 30 000. These Mn values ​​can correspond to an intrinsic viscosity of 0.8 or more, determined in m-cresol according to ISO standard 307:2007, but changing the solvent (m-cresol is used instead of sulfuric acid, the temperature is 20° C.).

[0161] Examples of suitable semi-crystalline thermoplastic polymers in the present invention include: Copolymers, especially polyamides containing aromatic and / or alicyclic structures, including polyamide-polyether and polyester copolymers; Polyaryletherketone (PAEK), Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polyetherketoneetherketoneketone (PEKEKK), Polyimides, in particular polyetherimides (PEI) or polyamide-imides, Polysulfones (PSU), in particular polyarylsulfones such as polyphenylsulfone (PPSU), Polyethersulfone (PES).

[0162] Semicrystalline polymers are more particularly preferred, especially polyamides and their semicrystalline copolymers.

[0163] The nomenclature used to define polyamides is described in ISO standard 1874-1:2011 "Plastics - Polyamide (PA) molding and extrusion materials - Part 1: Nomenclature", in particular page 3 (Tables 1 and 2), and is well known to those skilled in the art.

[0164] The polyamide may be a homopolyamide or a copolyamide or a mixture thereof.

[0165] Advantageously, the semicrystalline polyamide is a semiaromatic polyamide, in particular of formula X / Yar as described in EP 1 505 099 B1, in particular of formula A / XT, in which A is selected from units resulting from amino acids, units resulting from lactams and units having the formula (Ca diamine)(Cb diacid), in which a represents the number of carbon atoms of the diamine and b represents the number of carbon atoms of the diacid, a and b each being between 4 and 36, advantageously between 9 and 18, the units (Ca diamine) being selected from linear or branched aliphatic diamines, cycloaliphatic diamines and alkylaromatic diamines, and the units (Cb diacid) being selected from linear or branched aliphatic diacids, cycloaliphatic diacids and aromatic diacids, XT represents units resulting from the polycondensation of Cx diamines and terephthalic acid, x represents the number of carbon atoms of the Cx diamine, x being between 5 and 36, advantageously between 9 and 18, in particular polyamides of formula A / 5T, A / 6T, A / 9T, A / 10T or A / 11T, A being as defined above, more particularly PAMPMDT / 6T, PA11 / 10T, PA5T / 10T, PA11 / B The polyamide is selected from ACT, PA11 / 6T / 10T, PAMXDT / 10T, PAMPMDT / 10T, PABACT / 10T, PABACT / 6T, PABACT / 10T / 6T, PA11 / BACT / 6T, PA11 / MPMDT / 6T, PA11 / MPMDT / 10T, PA11 / BACT / 10T, PA11 / MXDT / 10T, 11 / 5T / 10T.

[0166] T corresponds to terephthalic acid, MXD corresponds to m-xylylenediamine, MPMD corresponds to methylpentamethylenediamine and BAC corresponds to bis(aminomethyl)cyclohexane. The semi-aromatic polyamides as defined above have in particular a Tg of 80° C. or higher.

[0167] Thermosetting polymer P2j: The thermosetting polymer is selected from epoxy or epoxy-based resins, polyesters, vinyl esters, resins based on polyisocyanates, especially polyisocyanurates and polyurethanes, or mixtures thereof, especially epoxy or epoxy-based resins, or resins based on polyisocyanates, especially polyisocyanurates.

[0168] Advantageously, each composite reinforcing layer consists of a composition comprising the same type of polymer, in particular an epoxy or epoxy-based resin, or a resin based on a polyisocyanate, in particular a polyisocyanurate.

[0169] The composition comprising the polymer P2j may be transparent to radiation suitable for welding.

[0170] As regards the fibres which constitute the fibre material, these are in particular fibres of mineral, organic or vegetable origin.

[0171] Advantageously, the fibrous material may or may not be sized.

[0172] The fibre material may therefore contain up to 3.5% by weight of organic material (of the thermoset or thermoplastic type) called size.

[0173] Among the fibres of mineral origin, mention may be made, for example, of carbon fibres, glass fibres, basalt or base fibres, silica fibres or silicon carbide fibres. Among the fibres of organic origin, mention may be made, for example, of fibres based on thermoplastic or thermosetting polymers, such as semi-aromatic polyamide fibres, aramid fibres, polyester fibres or polyolefin fibres. Preferably, they are based on amorphous thermoplastic polymers and have a glass transition temperature Tg, if amorphous, higher than the Tg of the thermoplastic polymer or polymer blend constituting the pre-impregnated matrix, or if semi-crystalline, higher than the Tm of the thermoplastic polymer or polymer blend constituting the pre-impregnated matrix. Advantageously, they are based on semi-crystalline thermoplastic polymers and have a melting temperature Tm, if amorphous, higher than the Tg of the thermoplastic polymer or polymer blend constituting the pre-impregnated matrix, or if semi-crystalline, higher than the Tm of the thermoplastic polymer or polymer blend constituting the pre-impregnated matrix. There is therefore no risk of the constituent organic fibres of the fibre material melting during impregnation with the thermoplastic matrix of the final composite. Among the fibres of vegetable origin, mention may be made of natural fibres based on flax, hemp, lignin, bamboo, silk, especially spider silk, sisal and other cellulose fibres, especially viscose fibres, which can be used pure, treated or coated with a coating layer to promote adhesion and impregnation of the thermoplastic polymer matrix.

[0174] The textile material may also be a textile made by knitting or weaving the fibers.

[0175] It can also accommodate fibers having supporting threads.

[0176] These constituent fibers can be used alone or in admixture. Thus, organic fibers can be mixed with mineral fibers to form a pre-impregnated fibrous material pre-impregnated with a thermoplastic polymer powder.

[0177] The organic fiber rovings can have several basis weights. Furthermore, they can exhibit several shapes. The constituent fibers of the fiber material can also be in the form of a mixture of these reinforcing fibers of various shapes. The fibers are continuous.

[0178] Preferably, the fibrous material is selected from glass fibres, carbon fibres, basalt or basalt-based fibres or mixtures thereof, in particular carbon fibres.

[0179] It is used in the form of a roving or several rovings.

[0180] According to a third aspect, the invention relates to the use of 0.05% to 10% by weight, in particular 0.1 to 9% by weight, of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, in particular polymaleic anhydrides and polyepoxides, with 88 to 99.95% by weight, in particular 89 to 99.9% by weight, of at least one semicrystalline aliphatic polyamide having a carbon number per nitrogen atom of 7 or more, more particularly 8 or more, and optional additives for the constitution of a composition for blow moulding or extrusion, in particular blow moulding, as defined above, having a melt viscosity after compounding of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in plane-plane geometry according to ISO standard 6721-10:2015 at a temperature of 250 ° C, a frequency of 0.292 rad / s and a deformation of 2%.

[0181] The term "single-layer or multi-layer tubular structure" is therefore understood to mean a tank comprising or consisting of one or more layers, i.e. a sealing layer and optionally one or more reinforcing layers, or multiple sealing layers and optionally multiple reinforcing layers, or multiple sealing and reinforcing layers, or a sealing and reinforcing layer.

[0182] A single or multi-layer tubular structure in the present invention also refers to a pipe or tube intended for transporting hydrogen from a tank to a fuel cell and comprising or consisting of one or more layers as defined above.

[0183] All the properties defined above for the first aspect relating to the composition are valid for this third aspect.

[0184] According to a fourth aspect, the invention relates to a method for preparing a composition for blow moulding or extrusion, in particular blow moulding, as defined above, characterized in that it comprises a step of compounding said composition.

[0185] All the properties defined above for the first aspect relating to the composition are valid for this fourth aspect.

[0186] The compounding process is carried out in a specific manner so that the alloy has a melt viscosity of 10000 to 300000 Pa.s, preferably 15000 to 220000 Pa.s, measured in a plane geometry according to ISO standard 6721-10:2015 at a temperature of 250°C, a frequency of 0.292 rad / s and a deformation of 2%.

[0187] These viscosities can be obtained, for example, by compounding at a temperature of the molten polymer above 280° C., preferably above 300° C., by increasing the residence time in the compounder. The branching reaction is advantageously catalyzed, for example, with phosphonium salts or hindered amines. The average residence time is advantageously between 20 seconds and 10 minutes, more advantageously between 45 seconds and 6 minutes.

[0188] In one embodiment, the compounding is carried out at a temperature of the molten polymer above 280° C., preferably above 300° C., with an average residence time of between 20 seconds and 10 minutes, very advantageously between 45 seconds and 6 minutes.

[0189] According to a fifth aspect, the present invention relates to a process for the preparation of a monolayer or multilayer tubular structure as defined above, characterized in that it comprises a step of blow moulding or extrusion, in particular blow moulding, of a composition as defined above.

[0190] In one embodiment of this fifth aspect, the method comprises the preliminary step of formulating a composition as defined above.

[0191] The pre-compounding step is carried out in particular as defined above.

[0192] All the properties defined above for the first aspect relating to the composition are valid for this fifth aspect. EXAMPLES

[0193] The comparative compositions (CE1-CE4) and compositions of the present invention (CI1-CI6) in Table 2 below were prepared by compounding under the following conditions: The alloys were produced using a ZSK 40 mm twin screw extruder (Coperion) with a barrel temperature set at 280° C., a screw speed of 300 rpm and a throughput of 60 kg / h. As the PA6, polyamide 6 with an acid chain end concentration of 25 μeq / g and an amine chain end concentration of 22 μeq / g was used. As the PA610, polyamide 610 having an acid chain end concentration of 27 μeq / g and an amine chain end concentration of 19 μeq / g was used. As the PA612, polyamide 612 having an acid chain end concentration of 22 μeq / g and an amine chain end concentration of 20 μeq / g was used. As PA11, phosphoric acid-catalyzed polyamide 11 with an acid chain end concentration of 30 μeq / g and an amine chain end concentration of 33 μeq / g was used. Joncryl ADR 4400 is manufactured by BASF. The Xibond 125 is manufactured by Polyscope. Lotader 3410 is derived from SK functional polymers. The stabilizer Anox NBD TL 89 is manufactured by SIgroup.

[0194] The melt viscosity was measured using an Ares G2 rotational rheometer with a 25 mm plane-plane geometry at a temperature of 250° C. and 0.292 rad / s (5 min residence time before firing under nitrogen, 2% deformation, 628 rad / s sweep at 0.062 rad / s and 3 points per 10, taken over 3 cycles, 1.5 mm gap).

[0195] The Rheotens force is determined using a Rheotens 71.97 instrument from Gottfert. The Rheotens instrument is an apparatus equipped with a notched wheel capable of pulling a ring at the exit of a Rheotester 2000 capillary rheometer from Gottfert: capillary with L / D = 30 and D = 1 mm at a temperature of 250 °C, shearing in a 100 s-1 die, distance between the exit of the ring and the axis of the notched wheel 105 mm, acceleration of the wheel 2.4 mm / s -2 Water absorption is determined after saturation in either an oven or in water under a controlled atmosphere of 100% RH, in all cases at 70° C., and the measurements are made by weighing the samples at 23° C. at regular sampling times spaced over several days until an equilibrium state is observed, which is reached when the mass of the sample becomes constant (within the measurement uncertainty) over three consecutive sampling times. In the case of conditioning in water, the equilibrium reached corresponds to water saturation of the polymer at a temperature of 70° C.

[0196] MFI, an abbreviation for Melt Flow Index, was measured according to ISO standard 1133:2011.

[0197] A 2 mm thick liner made from the composition of the present invention was prepared by blow molding and tested for hydrogen permeability at 15°C.

[0198] This consists of sweeping the top surface of the film with the test gas (hydrogen) and measuring by gas chromatography the flow diffusing underneath through the film, swept with a carrier gas: nitrogen.

[0199] The experimental conditions are shown in Table 1: [Table 1] TIFF2024524894000001.tif80170

[0200] The results obtained are then compared to the requirements of CSA / ANSI Standard CHMC2.19 "Materials Conformity Qualification Evaluation" listed in Table 2. [Table 2] TIFF2024524894000002.tif27170

[0201] The inventive and comparative compositions were tested on several parameters and the results are detailed in Table 3. [Table 3] TIFF2024524894000003.tif124170

[0202] The results show that the use of a specific range of branching agents and of a polyamide with an average number of carbon atoms per nitrogen atom of at least 7 makes it possible to obtain compositions that offer the best compromise in terms of various properties such as Rheotens force, water absorption, viscosity at 0.292 rad / s and hydrogen permeability.

[0203] All compositions according to the invention have an MFI equal to 0, which means that nothing flows through the machine.

Claims

1. A composition for blow molding or extrusion, particularly for blow molding, comprising: a) 88% to 99.95% by weight, more particularly 89% to 99.9% by weight, especially 93% to 99.9% by weight of at least one semi-crystalline aliphatic polyamide having 7 or more carbon atoms per nitrogen atom, more particularly 8 or more; b) 0.05% to 10% by weight, more particularly 0.1% to 9% by weight, especially 0.1% to 5% by weight of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydride and polyepoxides; c) 0 to 2% by weight, more particularly 0.1 to 2% by weight of at least one additive wherein after compounding, the composition has a melt viscosity of 10,000 to 300,000 Pa·s, preferably 15,000 to 220,000 Pa·s, measured in a plane-plane geometry according to ISO standard 6721-10:2015 at a temperature of 250 °C, a frequency of 0.292 rad / s and a deformation of 2%; the sum of components a) + b) + c) is 100% by weight, a composition for blow molding or extrusion, particularly for blow molding.

2. The composition for blow molding or extrusion, particularly for blow molding according to claim 1, characterized in that the compounding is carried out at a temperature of the molten polymer above 280 °C, preferably above 300 °C, with an average residence time of 20 seconds to 10 minutes, very preferably 45 seconds to 6 minutes.

3. The composition for blow molding or extrusion, particularly for blow molding according to claim 1, characterized in that impact modifiers are excluded from the composition.

4. The composition for blow molding or extrusion, particularly for blow molding according to claim 1, characterized in that the branching agent has an average functionality of 1.8 to 200, preferably 2.1 to 150 with respect to epoxy, anhydride or isocyanate functional groups.

5. The composition for blow molding or extrusion, particularly for blow molding according to claim 4, characterized in that the branching agent has an average equivalent weight of 100 to 10,000 g / mol, preferably 120 to 6,000 g / mol, especially 140 to 3,300 g / mol with respect to epoxy, anhydride or isocyanate functional groups.

6. The composition for blow molding or extrusion, particularly for blow molding according to claim 1, characterized in that the Rheotens force of the composition after compounding is 22 mN to 200 mN, more particularly 25 mN to 150 mN.

7. The composition for blow molding or extrusion, particularly for blow molding according to claim 1, wherein the semi-crystalline aliphatic polyamide is selected from PA610, PA612, PA614, PA10, PA11 and PA12, more particularly from PA610, PA612 and PA11.

8. A single-layer or multi-layer tubular structure for the purpose of hydrogen transport, distribution or storage, comprising hydrogen, particularly at least one sealing layer (1) comprising the composition defined in claim 1.

9. The single-layer or multi-layer tubular structure according to claim 8, wherein the sealing layer is present in hydrogen and the total proportion of impurities extracted from the sealing layer after contact with hydrogen is 3% by weight or less, more particularly less than 2% by weight, of the total of the components of the composition of the sealing layer, and the total proportion of impurities is determined according to the impurity test defined in CSA / ANSI standard CHMC2:

19.

10. The single-layer or multi-layer tubular structure according to claim 8, further comprising at least one composite reinforcing layer (2), wherein the innermost said composite reinforcing layer is welded or not welded to the outermost adjacent said sealing layer.

11. Use for the constitution of a composition for blow molding or extrusion, particularly for blow molding, as defined in claim 1, of 0.05% to 10% by weight, more particularly 0.1% to 9% by weight, of at least one branching agent selected from polyepoxides, polyanhydrides and polyisocyanates, more particularly polymaleic anhydride and polyepoxides, 88% to 99.95% by weight, more particularly 89 to 99.9% by weight, of at least one semi-crystalline aliphatic polyamide having 7 or more carbon atoms per nitrogen atom, more particularly 8 or more, and optional additives, wherein the melt viscosity of the composition after compounding is 10,000 to 300,000 Pa·s, preferably 15,000 to 220,000 Pa·s, when measured in a plane-plane geometry according to ISO standard 6721-10:2015 at a temperature of 250 °C, a frequency of 0.292 rad / s and a deformation of 2%.

12. A method for preparing a composition for blow molding or extrusion, particularly for blow molding, as defined in claim 1, comprising the step of compounding said composition.

13. A method for preparing a single-layer or multi-layer tubular structure as defined in claim 8, characterized by comprising the step of blow molding or extruding, in particular blow molding, the composition defined in claim 1. A method for preparing a single-layer or multi-layer tubular structure as described in claim 11, characterized by comprising a preliminary step of compounding the composition defined in claim 1. ​