Flexible composition with improved slip resistance

Abstract

The invention relates mainly to a polymer composition comprising: (a) 55% to 99%, preferably 60% to 95%, advantageously 65% to 90%, and in particular 70% to 85% by weight of polyether block amide (PEBA) having a ratio of the number-average molar mass of the polyamide blocks to that of the polyether blocks of 1.0 or less; (b) 1% to 45% by weight of a modifier selected from among: i. a thermoplastic elastomer in the form of a block copolymer with a ratio D of the number-average molar mass of the rigid blocks to that of the soft blocks of less than 0.8; ii. a crude or crosslinked rubber; and iii. combinations thereof; (c) 0% to 5% by weight of additives; and (d) 0% to 5% by weight of fillers, the sum of the percentages of components (a) to (d) adding up to 100%, and wherein the composition comprises less than 4% by weight of carbon black.

Description

[0001] FLEXIBLE COMPOSITION WITH IMPROVED SLIP RESISTANCE

[0002] [Technical field]

[0003] This patent application relates to flexible elastomer-based compositions with improved slip resistance, their manufacturing process, articles comprising these compositions, and the use of these compositions, particularly for the manufacture of sports shoe soles.

[0004] [Previous technique]

[0005] Thermoplastic elastomers (TPEs) are widely used, for example in the field of sports equipment, particularly for the manufacture of soles or sole components of sports shoes.

[0006] In these applications, materials with a specific property profile are sought, including good elastic recovery ensuring good responsiveness, low density, low dissipation factor (tan delta), high tensile elongation at break, low tensile residual deformation and good ability to withstand repeated impacts and return to the original shape.

[0007] To improve the safety and durability of footwear, materials are sought that combine high slip resistance on wet surfaces with high abrasion resistance. Furthermore, the material should not leave marks on the floor and should retain an attractive appearance after abrasion. To ensure compatibility with most footwear manufacturing processes, these materials must also exhibit good overmolding and injection molding properties.

[0008] US patent application 2015 / 0267045 Al describes lightweight composite materials comprising rubber, a polymer, including thermoplastic polyurethane (TPU) or polymethacrylate, and one or more fillers or additives. Their manufacture requires several steps and a lengthy production time.

[0009] Patent application WO 2016 / 033273 Al describes shoe soles with improved slip resistance by promoting the removal of wet soil accumulated outside a profiled sole, the sole having on its outer surface a polymeric layer capable of absorbing water, which is expelled under compression and removes the soil from the interface.

[0010] Furthermore, patent application EP 0 656 388 Al describes composites obtained by dynamic vulcanization of a functionalized and vulcanizable elastomer when mixed with a polyether or amorphous polyester block copolymer in the presence of a vulcanization system. These composites are envisioned, among other things, as wear layers or abrasion-resistant and slip-resistant cleats for polyetheresteramide soles of footwear. These compositions are obtained by a process that exhibits low productivity and is batch-based.

[0011] Patent application WO 2023 / 118761 describes compositions comprising PEBA and cross-linked rubber powder. These compositions exhibit good elastic recovery, low density, and good anti-slip properties. However, they tend to leave marks on the floor when subjected to abrasion. Furthermore, their elongation at break and injection moldability are generally insufficient for use as athletic shoe soles.

[0012] Patent application WO 2023 / 118760 describes compositions comprising a thermoplastic elastomer and a cross-linked rubber powder. These compositions exhibit good anti-slip properties but also tend to mark the floor when subjected to abrasion.

[0013] [Summary of the invention]

[0014] The invention therefore aims to provide a composition that meets all these requirements, and in particular exhibits resistance to abrasion and slippage, with a high coefficient of friction on wet surfaces. The invention also aims to provide a composition that leaves little or no marks on the floor.

[0015] The invention therefore aims to provide a polymer composition comprising:

[0016] (a) 55 to 99%, preferably 60 to 95%, advantageously 65 to 90%, and in particular 70 to 85% by weight of polyether block amide (PEBA) having a number-average molar mass ratio of polyamide blocks and polyether blocks less than or equal to 1.0, preferably less than 0.8;

[0017] (b) 1 to 45%, preferably 5 to 40%, advantageously 10 to 35%, and in particular 15 to 30% by weight of a modifier selected from:

[0018] (i) a thermoplastic elastomer in the form of a block copolymer with a number-average molar mass ratio D of the rigid blocks to the flexible blocks of less than 0.8, preferably less than 0.7, and advantageously less than 0.5; and

[0019] (ii) a rubber, raw or cross-linked; and

[0020] (c) 0 to 5%, preferably 0.1 to 4%, including 1 to 2% by weight of additives; and

[0021] (d) 0 to 5%, preferably 0.5 to 3% by weight of fillers, the sum of the percentages by weight of components (a) to (d) adding up to 100%, in which the composition comprises less than 4%, preferably less than 2%, and advantageously less than 1% by weight of carbon black.

[0022] In embodiments, the invention relates to a polymer composition comprising: (a) 55 to 99%, preferably 60 to 95%, advantageously 65 to 90%, and in particular 70 to 85% by weight of at least one polyether block amide (PEBA) having a number-average molar mass ratio of polyamide blocks and polyether blocks less than or equal to 1.0, preferably less than 0.8;

[0023] (b) 1 to 45%, preferably 5 to 40%, advantageously 10 to 35%, and in particular 15 to 30% by weight of at least one modifier selected from:

[0024] (i) at least one thermoplastic elastomer in the form of a block copolymer with a number-average molar mass ratio D of the rigid blocks to the flexible blocks of less than 0.8, preferably less than 0.7, and advantageously less than 0.5; and

[0025] (ii) at least one type of rubber, raw or crosslinked; and

[0026] (iii) combinations of these;

[0027] (c) 0 to 5%, preferably 0.1 to 4%, including 1 to 2% by weight of additives; and

[0028] (d) 0 to 5%, preferably 0.5 to 3% by weight of fillers, the sum of the percentages by weight of components (a) to (d) adding up to 100%, in which the composition comprises less than 4%, preferably less than 2%, and advantageously less than 1% by weight of carbon black.

[0029] According to a preferred embodiment, the composition has a Shore hardness of 10A to 100A, preferably from 20A to 90A, and in particular from 40A to 85A.

[0030] Preferably, the PEBA comprises polyamide blocks selected from the group consisting of PA 6, PA 10, PA 11, PA 12, PA 54, PA 59, PA 510, PA 512, PA 513, PA 514, PA 516, PA 518, PA 536, PA 64, PA 66, PA 69, PA 610, PA 612, PA 613, PA 614, PA 616, PA 618, PA 636, PA 912, PA 104, PA 109, PA 1010, PA 1012, PA 1013, PA 1014, PA 1016, PA 1018, PA 1036, PA 10T, PA 124, PA 129, PA 1210, PA 1212, PA 1213, PA 1214, PA 1216, PA 1218, PA 1236, PA 12T or their copolymers.

[0031] In particular, PEBA may include polyether blocks selected from the group consisting of PEG (polyethylene glycol) blocks, PPG (propylene glycol) blocks, PO3G (polytrimethylene glycol) blocks and PTMG (polytetramethylene glycol) blocks.

[0032] Preferably, the PEBA includes PA 11 and PTMG blocks or PA 12 and PTMG blocks.

[0033] According to one embodiment, when the modifier is a thermoplastic elastomer, it is chosen from thermoplastic polyurethanes (TPU) and styrene copolymers.

[0034] According to another embodiment, when the modifier is a rubber, it is selected from the group consisting of polyisoprene rubber, ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), polybutadiene rubber, styrene-butadiene rubber (SBR), butyl rubber (isobutylene-isoprene), and a mixture thereof. Advantageously, when the modifier is a rubber, it is dispersed in the composition as nodules with an average diameter in number less than 850 µm, preferably less than 800 µm, advantageously less than 750 µm.

[0035] According to a second aspect, the invention relates to a method for manufacturing the composition according to the invention, comprising the steps of:

[0036] (i) mix in a molten state, preferably in a twin-screw extruder or in a co-mixer:

[0037] (a) 55 to 99% by weight of polyether block amide (PEBA) having a number-average molar mass ratio of polyamide blocks and polyether blocks less than or equal to 1.0;

[0038] (b) 1 to 45% by weight of a modifier selected from: i. a thermoplastic elastomer in the form of a block copolymer with a number-average molar mass ratio D of rigid blocks to flexible blocks of less than 0.8; and ii. a rubber, raw or crosslinked;

[0039] (c) 0 to 5% by weight of additives; and

[0040] (d) 0 to 5% by weight of fillers; the sum of the percentages by weight of components (a) to (d) adding up to 100%, in which the composition comprises less than 4% carbon black,

[0041] (ii) optionally, shape the mixture into granules, filaments, or powder; and

[0042] (iii) retrieve the resulting composition.

[0043] In some embodiments, the invention relates to a method for manufacturing the composition according to the invention, comprising the steps of:

[0044] (i) mix in a molten state, preferably in a twin-screw extruder or in a co-mixer:

[0045] (a) 55 to 99% by weight of at least one polyether block amide (PEBA) having a number-average molar mass ratio of polyamide blocks and polyether blocks less than or equal to 1.0;

[0046] (b) 1 to 45% by weight of at least one modifier selected from: i. at least one thermoplastic elastomer in the form of a block copolymer with a number-average molar mass ratio D of rigid blocks to flexible blocks of less than 0.8; and ii. at least one rubber, raw or crosslinked; and iii. combinations thereof;

[0047] (c) 0 to 5% by weight of additives; and

[0048] (d) 0 to 5% by weight of fillers; the sum of the percentages by weight of components (a) to (d) adding up to 100%, in which the composition comprises less than 4% carbon black,

[0049] (ii) optionally, shape the mixture into granules, filaments or powder; and (iii) recover the resulting composition.

[0050] According to a third aspect, the invention aims at the use of the composition according to the invention for the manufacture of an article selected from the group consisting of shoe components, sports equipment parts, treadmills, aquatic equipment, eyeglass frame parts, ski mask frames, vibration isolation parts in electronics and on machines, external battery cases, automotive parts and wheel treads.

[0051] Preferably, the composition is used for the manufacture of an outsole or an outsole.

[0052] According to a fourth aspect, the invention relates to a method of manufacturing an article implementing the composition according to the invention.

[0053] In particular, the invention relates to a method of manufacturing an article comprising shaping a composition according to the invention.

[0054] According to a fifth aspect, the invention relates to an article comprising the composition according to the invention selected from the group consisting of shoe components, sports equipment parts, treadmills, aquatic equipment, eyeglass frame parts, ski mask frames, vibration isolation parts in electronics and on machines, external battery cases, automotive parts and wheel treads.

[0055] Advantageously, it is a wear sole or an outsole.

[0056] Finally, according to a sixth aspect, the invention relates to a method for recycling an article according to the invention, comprising the following successive steps:

[0057] (i) recovery, after possible separation, of at least a part of said article in thermoplastic material comprising a composition according to the invention;

[0058] (ii) grinding of the thermoplastic material to obtain particles,

[0059] (iii) melting of the particles to obtain a molten mixture, and

[0060] (iv) optionally, adding other components to the molten mixture, and

[0061] (v) optionally, the formation of granules, filaments or powders from the molten mixture obtained at the end of step iii) or iv), and

[0062] (vi) optionally, shaping of granules, filaments or powders.

[0063] [Brief description of the figures]

[0064] The invention will be better understood with regard to the following description and figures, which show:

[0065] Fig. 1: Appearance of the composition according to the comparison example EC1 after the abrasion resistance test according to DIN ISO 4649:2017; and Fig. 2: Appearance of the composition according to the example according to the invention Ell after the abrasion resistance test according to DIN ISO 4649:2017.

[0066] [Description of the embodiments]

[0067] Definition of terms

[0068] Throughout the description, the terms listed below have the following meanings.

[0069] The term "polymer composition" refers to a macroscopically homogeneous composition comprising several polymers in a mixture. The term also encompasses compositions composed of immiscible phases dispersed at the micrometer scale. For example, rubber may be present in the composition in dispersed form, such as nodules. However, the number-average diameter of the dispersed phase particles or nodules is advantageously less than 850 pm, preferably less than 800 pm, and particularly less than 750 pm. Advantageously, the number-average diameter of the nodules is greater than 1 pm, advantageously greater than 5 pm, and particularly greater than 20 pm. The number-average diameter of the nodules in the composition can be measured by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).The SEM has a large field of view and allows observation at magnifications up to x5000. For observing subnanometer particles, the use of TEM is preferable. Preferably, a molded sample is observed by SEM, allowing for an overview, followed by more precise observation by TEM to observe the smallest nodules according to the following protocol:

[0070] (i) Obtaining a smooth surface: cold microtome surfacing with a diamond knife;

[0071] (ii) Labeling of one of the two phases: depending on the chemical composition, either labeling of the dispersed phase with a 2% aqueous solution of osmium or ruthenium tetroxide by immersion or vapor, for a time to be defined from a few seconds to a few minutes, depending on the observation technique used; or labeling of the matrix with phosphotungstic acid (2%) for a time to be defined from a few seconds to a few minutes depending on the observation technique used;

[0072] (iii) Observation of the morphology by SEM with the appropriate magnification to observe both the continuous and dispersed phases of the composition, the dispersed phase having at least 200 nodules; and

[0073] (iv) Observation of the morphology by TEM with the appropriate magnification to observe both the continuous and dispersed phases of the composition, the dispersed phase having at least 200 nodules. A maximum magnification of 2,000x is generally used;

[0074] (v) Analysis of images obtained by SEM and TEM using software such as ImageJ:

[0075] 1. Segmentation of the dispersed phase; and 2. Analysis of the nodule size distribution and calculation of the number mean, volume mean of equivalent circle diameters, standard deviation, and distribution histogram for each image, (vi) Calculation of the number mean equivalent diameters obtained from the SEM and TEM images to obtain the number mean diameter of the nodules in the composition

[0076] The term “PEBA” refers to a sequenced copolymer comprising polyamide blocks and polyether blocks.

[0077] The term "polyamide" or "PA" refers throughout to a homopolyamide or copolyamide, that is, the products of the condensation of polyamide monomers, particularly lactams, α,co-aminocarboxylic acids and / or dicarboxylic acids and diamines. The nomenclature used to define polyamides is described in ISO 1874-1:1992 "Plastics - Polyamide (PA) materials for molding and extrusion - Part 1: Designation", specifically on page 3 (Tables 1 and 2).

[0078] The term "modifying" refers to a thermoplastic or thermosetting elastomer that has the effect of modifying the properties of the matrix, formed here mainly by a PEBA.

[0079] The term "thermoplastic elastomer" or "TPE" refers to a polymer comprising rigid and flexible blocks, in the form of a block copolymer, in which the rigid blocks, generally semi-crystalline or having a high glass transition temperature, melt or soften as the temperature increases. Above the melting or glass transition temperature of the rigid block domains, the material can be processed using conventional thermoplastic polymer processing techniques. Below the melting temperature of the rigid block domains, the thermoplastic elastomer exhibits elastic properties similar to those of cross-linked elastomers. For the purposes of this discussion, PEBA (polyethylene deposition modeling alloys) are explicitly excluded from this definition of TPE.

[0080] The term "rubber" refers to a thermosetting elastomer. The term encompasses both crosslinkable but not yet crosslinked rubbers, also called "raw rubber" or "unrefined rubber", and crosslinked rubbers, in which the molecular chains are linked by bridges forming a three-dimensional network.

[0081] The term "copolymer" refers to a polymer resulting from the copolymerization of at least two chemically different types of monomers, called comonomers. A copolymer is therefore composed of at least two repeating units. It can also be composed of three or more repeating units.

[0082] The term "alloy" refers to a homogeneous mixture (macroscopically, i.e., visible to the naked eye). In one embodiment, the various components of the alloy are bonded by one or more covalent bonds. In the following, physical quantities are, unless otherwise stated, measured under standard temperature and pressure conditions, specifically at 23°C and atmospheric pressure. Furthermore, the expressions "between... and..." and "from... to..." used in this description should be understood as including each of the specified limits. Finally, unless otherwise stated, percentages are expressed by weight relative to the total weight of the composition.

[0083] PEBA

[0084] The composition according to the invention therefore comprises, as a major component, a particular polyether block amide (PEBA).

[0085] PEBAs result from the polycondensation of reactive-end polyamide blocks (rigid blocks) with reactive ends and reactive-end polyether blocks (flexible blocks). Specifically, PEBAs can result from the polycondensation of:

[0086] (a) diamine-ended polyamide blocks with dicarboxyl-ended polyoxyalkylene blocks; or of

[0087] (b) dicarboxylic end polyamide blocks with polyetherdiols (α,(μ-dihydroxylated) polyoxyalkylene blocks), the products obtained in this case being polyetheresteramides.

[0088] Preferably, PEBA in the composition comprises at least 50%, preferably 50 to 90%, in particular 55 to 85% and especially 60 to 80% by weight of polyether blocks.

[0089] Polyether blocks essentially comprise or are made up of alkylene oxide motifs.

[0090] These may include PEG (polyethylene glycol) blocks made of ethylene oxide motifs, PPG (propylene glycol) blocks made of propylene oxide motifs, PO3G (trimethylene ether glycol) blocks, PTMG (polytetramethylene glycol) blocks made of tetrahydrofuran motifs, with PTMG blocks being preferred.

[0091] PEBAs can include in their chain several distinct types of polyethers, the copolyethers being either block or statistical.

[0092] Preferably, PEBA in the composition comprises up to 50%, in particular 10 to 50%, in particular 15 to 45% and in particular 20 to 40% by weight of polyamide blocks.

[0093] Polyamide blocks with dicarboxylic acid ends are obtained, for example, by the condensation of polyamide precursors in the presence of a dicarboxylic acid acting as a chain limiter. Polyamide blocks with diamine ends are obtained, for example, by the condensation of polyamide precursors in the presence of a diamine acting as a chain limiter.

[0094] Three types of polyamide blocks can be used to advantage.

[0095] According to one type, polyamide blocks are obtained by the condensation of a dicarboxylic acid preferably having 4 to 36 carbon atoms, particularly 4 to 20, and especially 6 to 18, and a diamine preferably having 2 to 20 carbon atoms, particularly 6 to 14. The dicarboxylic acid may be, in particular, an aliphatic, cycloaliphatic, or aromatic dicarboxylic acid. Examples include butanedioic acid, adipic acid, azelaic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, brassylic acid, thapsic acid, octadecanedicarboxylic acid, 1,4-cyclohexyldicarboxylic acid, terephthalic acid, isophthalic acid, and dimerized fatty acids.

[0096] Dimerized fatty acids preferably have a dimer content of at least 98%; preferably they are hydrogenated; these are for example the products marketed under the brand "PRIPOL" by the company "CRODA", or under the brand EMPOL by the company BASF, or under the brand Radiacid by the company OLEON, and polyoxyalkylenes α, co-diacids.

[0097] The diamine can be, in particular, an aliphatic, cycloaliphatic, or aromatic diamine. Examples include tetramethylenediamine, cadaverine, hexamethylenediamine, 1,10-decamethylenediamine, 1,12-dodecamethylenediamine, trimethylhexamethylenediamine, the isomers of bis-(4-aminocyclohexyl)methane (BACM), bis-(3-methyl-4-aminocyclohexyl)methane (BMACM), and 2-2-bis-(3-methyl-4-aminocyclohexyl)-propane (BMACP), p-amino-di-cyclohexylmethane (PACM), isophoronediamine (IPDA), 2,6-bis-(aminomethyl)norbornane (BAMN), and piperazine (Pip).

[0098] The polyamide block of the first type is preferably chosen from PA 412, PA 414, PA 418, PA 513, PA 516, PA 610, PA 612, PA 613, PA 614, PA 618, PA 912, PA 1010, PA 1012, PA 1014 and PA 1018.

[0099] According to a second type, polyamide blocks result from the condensation of one or more ct,(jo-aminocarboxylic acids and / or one or more lactams in the presence of a dicarboxylic acid having 4 to 18 carbon atoms or a diamine.

[0100] Examples of α,co-amino carboxylic acids include aminocaproic, amino-7-heptanoic, amino-10-decanoic, amino-11-undecanoic and amino-12-dodecanoic acids.

[0101] Lactams are preferably chosen from those which preferably have 6 to 12 carbon atoms, in particular caprolactam, oenantholactam and lauryllactam.

[0102] Advantageously, the second type polyamide blocks are chosen from PA 6, PA 10, PA 11 and PA 12 blocks.

[0103] According to a third type, polyamide blocks result from the condensation of monomers of the first and second type as described above respectively, for example of at least one α,co-aminocarboxylic acid or lactam with at least one diamine and at least one dicarboxylic acid.

[0104] Examples of third-type polyamide blocks include PA 66 / 6 and PA 66 / 610 / 11 / 12. Advantageously, the PEBA comprises polyamide blocks chosen from PA 54, PA 59, PA 510, PA 512, PA 513, PA 514, PA 516, PA 518, PA 536, PA 64, PA 66, PA 69, PA 610, PA 612, PA 613, PA 614, PA 616, PA 618, PA 636, PA 912, PA 10, PA 104, PA 109, PA 1010, PA 1012, PA 1013, PA 1014, PA 1016, PA 1018, PA 1036, PA 10T, PA 11, PA 12, PA 124, PA 129, PA 1210, PA 1212, PA 1213, PA 1214, PA 1216, PA 1218, PA 1236, PA 12T, and their copolymers.

[0105] Polyamide blocks with 7 or more, especially 9 or more carbon atoms per amide group, are particularly preferred. These polyamides can notably be chosen from PA 10, PA 11, PA 12, PA 513, PA 514, PA 516, PA 518, PA 536, PA 612, PA 613, PA 614, PA 616, PA 618, PA 636, PA 912, PA 104, PA 109, PA 1010, PA 1012, PA 1013, PA 1014, PA 1016, PA 1018, PA 1036, PA 129, PA 1210, PA 1212, PA 1213, PA 1214, PA 1216, PA 1218, PA 1236, PA 12T, and their copolymers.

[0106] Particularly preferred are the polyamide blocks of PEBA selected from the PA 11, PA 12, PA 10, PA 1010, and PA 1012 blocks, especially PA 11 and PA 12, and the polyether blocks of PEBA selected from the polyethylene glycol and polytetrahydrofuran blocks. The particularly preferred PEBAs include blocks of PA 11 and PTMG or of PA 12 and PTMG.

[0107] PEBAs can be obtained, in particular, by copolycondensation of polyetherdiol with polyamide blocks having carboxyl ends. The general two-step method for preparing PEBA copolymers having ester linkages between PA and PE blocks is described, for example, in document FR 2846332. The general method for preparing PEBA copolymers having amide linkages between PA and PE blocks is described, for example, in document EP 1482011. Polyether blocks can also be mixed with polyamide precursors and a diacid chain limiter to prepare polymers with polyamide and polyether blocks having statistically distributed motifs (one-step process).

[0108] PEBA may include, in addition to polyamide and polyether blocks, other additional blocks.

[0109] For example, PEBA can comprise three different types of blocks ("triblock"). This triblock can, for instance, comprise a polyamide block, a polyether block, and a polyester block. Alternatively, it can comprise a polyamide block and two different polyether blocks, for example, a PEG block and a PTMG block. The triblock PEBA is preferably a copolyetheresteramide.

[0110] The number-average molar mass (Mn) of the polyamide blocks in PEBA is preferably 400 to 20,000 g / mol, in particular 500 to 10,000 g / mol. Preferably, the number-average molar mass of the polyamide blocks in PEBA is less than 2,000 g / mol, and in particular less than 1,000 g / mol. In embodiments, the number-average molar mass of polyamide blocks in PEBA is 600 to 700 g / mol, or 700 to 800 g / mol, or 800 to 900 g / mol, or 900 to 1000 g / mol, or 1000 to 1100 g / mol, or 1100 to 1200 g / mol, or 1200 to 1300 g / mol, or 1300 to 1400 g / mol, or 1400 to 1500 g / mol, or 1500 to 1600 g / mol, or 1600 to 1700 g / mol, or 1700 to 1800 g / mol, or 1800 to 1900 g / mol, or 1900 to 2000 g / mol.

[0111] The number-average molar mass (Mn) of the polyether blocks is preferably 100 to 6000 g / mol, in particular 500 to 3000 g / mol. Preferably, the number-average molar mass of the polyether blocks is greater than 900 g / mol. In some embodiments, the number-average molar mass of the polyether blocks is 1000 to 1200 g / mol, or 1200 to 1400 g / mol, or 1400 to 1600 g / mol, or 1600 to 1800 g / mol, or 1800 to 2000 g / mol.

[0112] The number-average molar mass (Mn) can be adjusted by the chain limiter content. It can be calculated using the following relationship:

[0113] [Math 1]

[0114] In this formula, n monO mother represents the number of moles of monomer, chain limiter represents the number of moles of excess diacid limiter, MW mot if of repetition represents the molar mass of the repeating motif, and MW| im The chain length represents the molar mass of the excess diacid.

[0115] The number-average molar mass of polyamide blocks and polyether blocks can be measured before copolymerization of the blocks by gel permeation chromatography (GPC), according to ISO 16014-1:2019.

[0116] According to the invention, the ratio of the number-average molar mass of the polyamide blocks and the polyether blocks in the PEBA is less than or equal to 1.0, in particular less than 0.9, and in particular less than 0.8. This ratio can be calculated by dividing the number-average molar mass of the polyamide blocks by the number-average molar mass of the polyether blocks.

[0117] Advantageously, the ratio of the number-average molar mass of the polyamide blocks to that of the polyether blocks of the PEBA is from 0.1 to 1.0, preferably from 0.2 to 0.9 and especially from 0.3 to 0.8. In particular, the ratio can be from 0.1 to 0.2, or from 0.2 to 0.3, or from 0.3 to 0.4, or from 0.4 to 0.5, or from 0.5 to 0.6, or from 0.6 to 0.7, or from 0.7 to 0.8, or from 0.8 to 0.9, or from 0.9 to 1.0.

[0118] Indeed, when this ratio is too high, the material is too rigid, resulting in poor slip resistance on smooth and wet surfaces, and also discomfort when walking, especially on uneven ground. Conversely, when this ratio is too low, the material is too flexible and therefore no longer sufficiently resistant to abrasion, which reduces the shoe's lifespan.

[0119] PEBA in the composition preferably has an average number molar mass Mn as measured by size exclusion chromatography according to ISO 16014-1:2019 of between 10,000 and 70,000 g / mol, preferably between 20,000 and 70,000 g / mol, advantageously between 30,000 and 70,000 g / mol.

[0120] PEBAs are commercially available, and sold in particular by Arkema under the name PEBAX®, by Evonik under the name Vestamid®, by EMS under the name Grilamid® and by Sanyo under the name Pelestat®.

[0121] Modifiers

[0122] The composition according to the invention further comprises, as a minor component, a modifier, which may be either a specific thermoplastic elastomer or a rubber. More specifically, it comprises from 1 to 45%, preferably from 5 to 40%, advantageously from 10 to 35%, and particularly 15 to 30% by weight of such a modifier.

[0123] According to a first embodiment, the modifier is a thermoplastic elastomer in the form of a block copolymer with a number-average molar mass ratio D of rigid blocks and flexible blocks less than 0.8, preferably less than 0.7 and advantageously less than 0.5.

[0124] Preferably, the thermoplastic elastomer comprises rigid blocks of patterns selected from polyurethanes, polystyrene, and polyesters. Preferably, the thermoplastic elastomer comprises flexible blocks of patterns selected from polyols. Preferably, the thermoplastic elastomer is free of polysiloxane blocks. Preferably, the thermoplastic elastomer is free of polycarbonate blocks. The flexible and rigid blocks of the thermoplastic elastomer are advantageously covalently linked by functional groups selected from C-C bonds, esters, urethanes, and ureas.

[0125] Preferably, the thermoplastic elastomer is chosen from thermoplastic polyurethanes, styrene copolymers and polyester elastomers, preferably from thermoplastic polyurethanes and styrene copolymers.

[0126] Advantageously, the thermoplastic elastomer exhibits a tensile modulus, as measured according to ISO 527, of between 5 and 800 MPa, preferably between 10 and 300 MPa, and more preferably between 20 and 150 MPa. The tensile modulus can be controlled, in particular, by the ratio of the number-average molar mass of rigid blocks to the number-average molar mass of flexible blocks in the elastomer.

[0127] According to one embodiment, the thermoplastic elastomer also has a Shore hardness between 10A and 90A, in particular between 20A and 80A, more particularly between 25 and 75A, advantageously between 30 and 70A. The hardness can be measured according to ISO 48-5:2018.

[0128] Thermoplastic polyurethanes

[0129] The modifying element in the composition of the invention may be, in particular, a thermoplastic polyurethane (TPU).

[0130] Thermoplastic polyurethane is a rigid block and flexible block copolymer. It generally results from the reaction of at least one polyisocyanate (X) with at least one compound reactive with the isocyanate, preferably having two functional groups reactive with the isocyanate, more preferably a polyol, and optionally with a chain extender, optionally in the presence of a catalyst.

[0131] The rigid blocks of TPU can be motif blocks derived from polyisocyanates and chain extenders, while the flexible blocks mainly comprise motifs from compounds reactive with isocyanate, preferably polyols. The polyisocyanate can be aliphatic, cycloaliphatic, araliphatic, and / or aromatic. Preferably, the polyisocyanate is a diisocyanate.

[0132] Advantageously, the polyisocyanate is chosen from the group consisting of tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene 1,5-diisocyanate, 2-ethylbutylene-1,4-diisocyanate, 1,5-pentamethylene diisocyanate, 1,4-butylene diisocyanate, l-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,4-bis(isocyanatomethyl)cyclohexane, l,3-bis(isocyanatomethyl)cyclohexane (HXDI), 2,4-paraphenylene diisocyanate (PPDI), 2,4-tetramethylenexylene diisocyanate (TMXDI), 4,4'-, 2,4'- and / or 2,2'-Dicyclohexylmethane diisocyanate (H12 MDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and / or 1-methyl-2,6-cyclohexane diisocyanate, 2,2'-, 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4- and / or 2,6-toluene diisocyanate (TDI), diphenylmethane diisocyanate, 3,3'-dimethyl-diphenyl diisocyanate, 1,2- Diphenylethane diisocyanate, phenylene diisocyanate, methylene bis(4-cyclohexylisocyanate) (HMDI) and mixtures thereof.

[0133] Preferably, polyisocyanate is chosen from the group consisting of diphenylmethane diisocyanates (MDI), toluene diisocyanates (TDI), pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), methylene bis (4-cyclohexylisocyanate) (HMDI) and mixtures thereof.

[0134] Even more preferably, the polyisocyanate is 4,4'-MDI (4,4'-diphenylmethane diisocyanate), 1,6-HDI (1,6-hexamethylene diisocyanate), or a mixture thereof. Advantageously, it does not contain cycloaliphatic diisocyanate.

[0135] Preferably, the polyisocyanate is aliphatic.

[0136] The compound(s) reactive with isocyanate preferably have an average functionality between 1.8 and 3, more preferably between 1.8 and 2.6, and even more preferably between 1.8 and 2.2. The average functionality of the compound(s) reactive with isocyanate corresponds to the number of isocyanate-reactive functions in the molecules, calculated theoretically for one molecule from a quantity of compounds. Preferably, the compound reactive with isocyanate has, according to a statistical average, a Zerewitinoff number of active hydrogens within the above ranges.

[0137] Advantageously, the compound reactive with the isocyanate has at least one reactive group selected from the hydroxyl group, the amine group, the thiol group, and the carboxylic acid group. Preferably, the compound reactive with the isocyanate has at least one hydroxyl reactive group, and more preferably, several hydroxyl groups. Thus, particularly advantageously, the compound reactive with the isocyanate comprises or consists of a polyol. Preferably, the compound reactive with the isocyanate has a number-average molar mass, as determined by GPC according to ISO 16014-1:2012, of 500 to 100,000 g / mol, in particular 500 to 8,000 g / mol, and more preferably 700 to 6,000 g / mol, in particular 800 to 4,000 g / mol.

[0138] Preferably, the polyol is selected from the group consisting of polyester polyols, polyether polyols, polycarbonate diols, polyalkylene diols, and mixtures thereof. More preferably, the polyol is a polyether polyol, a polyester polyol, and / or a polycarbonate diol, so that the flexible blocks of the thermoplastic polyurethane are polyether blocks, polyester blocks, and / or polycarbonate blocks, respectively. Even more preferably, the flexible blocks of the thermoplastic polyurethane are polyether blocks and / or polyester blocks (the polyol being a polyether polyol and / or a polyester polyol). Preferably, the polyol does not contain polysiloxane diols (so that the flexible blocks of the thermoplastic polyurethane are free of polysiloxane blocks).In advantageous embodiments, the polyol does not comprise polycarbonate diols (so that the flexible blocks of thermoplastic polyurethane are devoid of polycarbonate blocks).

[0139] Examples of polyester polyols include polycaprolactone polyols and / or copolyesters based on one or more carboxylic acids selected from adipic acid, succinic acid, pentanedioic acid, and / or sebacic acid, and one or more alcohols selected from 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, and / or polytetrahydrofuran. Preferably, the polyol is not a cycloaliphatic diol.

[0140] More specifically, the copolyester may be based on adipic acid and a mixture of 1,2-ethanediol and 1,4-butanediol, or the copolyester may be based on adipic acid, succinic acid, pentanedioic acid, sebacic acid or mixtures thereof, and polytetrahydrofuran (tetramethylene glycol), or the copolyester may be a mixture of these copolyesters.

[0141] As a polyether polyol, polyetherdiols (i.e., aliphatic α,co-dihydroxylated polyoxyalkylene blocks) are preferably used. Preferably, the polyether polyol is a polyetherdiol based on ethylene oxide, propylene oxide, and / or butylene oxide, a block copolymer based on ethylene oxide and propylene oxide, polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetrahydrofuran, polybutane diol, or a mixture thereof.

[0142] The polyether polyol is preferably a polytetrahydrofuran (flexible blocks of thermoplastic polyurethane are therefore polytetrahydrofuran blocks) and / or a polypropylene glycol (flexible blocks of thermoplastic polyurethane are therefore polypropylene glycol blocks) and / or a polyethylene glycol (flexible blocks of thermoplastic polyurethane are therefore polyethylene glycol blocks), preferably a polytetrahydrofuran having a number-average molar mass of 500 to 15,000 g / mol, preferably 1,000 to 3,000 g / mol. The polyether polyol may be a polyetherdiol, which is the reaction product of ethylene oxide and propylene oxide; the molar ratio of ethylene oxide to propylene oxide is preferably 0.01 to 100, more preferably 0.1 to 9, more preferably 0.25 to 4, more preferably 0.4 to 2.5, more preferably 0.6 to 1.5 and it is more preferably 1.

[0143] The polyalkylene diols usable in the invention are preferably butadiene-based. One or more polyols may be used as a reactive compound with the isocyanate.

[0144] In a particularly preferred manner, the flexible blocks of TPU are blocks of polytetrahydrofuran, polypropylene glycol and / or polyethylene glycol.

[0145] Preferably, a chain extender (Y) is used for the preparation of thermoplastic polyurethane, in addition to the isocyanate and the compound reactive with the isocyanate.

[0146] The chain extender can be aliphatic, araliphatic, aromatic and / or cycloaliphatic.

[0147] It advantageously has a number-average molar mass of 50 to 499 g / mol. The number-average molar mass can be determined by GPC, preferably according to ISO 16014-1:2012. The chain extender preferably has two reactive groups with the isocyanate (also called "functional groups").

[0148] You can use a single chain extender or a mixture of at least two chain extenders.

[0149] The chain extender is preferably bifunctional. Examples of chain extenders are diamines and alkanediols having from 2 to 10 carbon atoms. In particular, the chain extender may be selected from the group consisting of 1,2-ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, 1,4-dimethanol cyclohexane, neopentyl glycol, hydroquinone bis(beta-hydroxyethyl) ether (HQEE), di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona- and / or deca-alkylene glycol, their respective oligomers, polypropylene glycol and mixtures thereof.More preferably, the chain extender is selected from the group consisting of 1,2-ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and mixtures thereof, and even more preferably from 1,3-propanediol, 1,4-butanediol, and / or 1,6-hexanediol. Even more preferably, the chain extender is a mixture of 1,4-butanediol and 1,6-hexanediol, more preferably in a molar ratio of 6:1 to 10:1.

[0150] Preferably, the TPU is semi-crystalline. Its melting temperature (Tf) is preferably between 100°C and 230°C, and even more preferably between 120°C and 160°C. The melting temperature can be measured according to ISO 11357-3 Plastics - Differential scanning calorimetry (DSC) Part 3.

[0151] Advantageously, the TPU can be recycled TPU and / or partially or completely bio-based TPU. Advantageously, the rigid polyurethane block is composed of a diisocyanate selected from 4,4'-MDI, HDI or PDI and / or a diol selected from butanediol, propanediol, pentanediol and hexanediol.

[0152] The ratio of the number average molar mass of rigid polyurethane blocks and flexible polyol blocks of TPU is preferably less than or equal to 1.0, in particular less than 0.9, and in particular less than 0.8. According to one embodiment, this ratio is from 0.1 to 1.0, preferably from 0.2 to 0.8 and in particular from 0.3 to 0.5.

[0153] According to one embodiment, PEBA forms an alloy with TPU during mixing.

[0154] Thus, TPU and PEBA can be bonded by one or more covalent bonds, for example, via a urethane group. Up to 10% by weight, and in particular up to 5% by weight, of PEBA can be covalently bonded to the thermoplastic polyurethane, preferably via a urethane group.

[0155] Styrene copolymers

[0156] The modifier in the composition of the invention may also be a styrene copolymer.

[0157] In the broadest sense, a styrene copolymer is a copolymer comprising at least one repeating unit containing styrene. However, generally, the styrene copolymer used in the composition of the invention comprises up to 50% by weight, preferably up to 45%, and advantageously up to 40% by weight of styrene.

[0158] This copolymer can be selected from among conjugated styrene and alpha-olefin or diene copolymers, such as ethylene, propylene, 1-butene, 1-octene, butadiene, or isoprene. Examples include the following block copolymers: styrene / ethylene-butene / styrene (SEBS), styrene-ethylene-propylene (SEP), styrene / ethylene-propylene / styrene (SEPS), styrene / isoprene / butadiene / styrene (SIBS), styrene / butadiene / styrene (SBS), and styrene / isoprene / styrene (SIS). The styrene / ethylene-butene / styrene (SEBS) and styrene-ethylene-propylene (SEP) block copolymers are particularly preferred.

[0159] The styrene copolymer is obtained by sequenced copolymerization. The copolymer can also have a linear or branched structure, with a linear structure being preferred.

[0160] The ratio of the number-average molar mass of rigid polystyrene blocks and of flexible blocks, for example conjugated alpha-olefins or dienes, is preferably less than or equal to 1.0, in particular less than 0.9, and in particular less than 0.8. According to one embodiment, this ratio is from 0.1 to 1.0, preferably from 0.2 to 0.8 and in particular from 0.3 to 0.5.

[0161] The styrene copolymer can also be hydrogenated. Preferably, it is hydrogenated.

[0162] Styrene copolymer can be functionalized, non-functionalized, or partially functionalized. A functionalized copolymer can be obtained by copolymerization with a comonomer containing reactive motifs, particularly acidic, anhydride, or epoxy groups. Styrene copolymer can also be grafted, notably by reacting the copolymer with a reagent such as an unsaturated epoxide like glycidyl methacrylate, an unsaturated carboxylic acid like (meth)acrylic acid, possibly partially or totally neutralized, or an unsaturated carboxylic acid anhydride like maleic anhydride, with maleic anhydride and glycidyl methacrylate being preferred. A grafted styrene copolymer preferably has a grafting ratio of 0.01 to 5%, particularly 0.1 to 3%, and especially 0.5 to 2% by weight.The styrene / ethylene-butene / maleic anhydride grafted block copolymer (SEBS-g-MAH) and the glycidyl methacrylate grafted block copolymer (SEBS-g-GMA) are particularly preferred.

[0163] Preferably the styrene copolymer contains less than 5%, advantageously less than 1% by weight of oil.

[0164] Rubber

[0165] According to a second embodiment, the modifier in the composition of the invention is a rubber.

[0166] Rubber can be raw, uncrosslinked rubber, or at least partially crosslinked rubber. Rubber can come from a wide variety of sources.

[0167] Rubber can be natural, synthetic, or a mixture of both. Natural rubber can be chosen from cis-1,4-polyisoprene and / or trans-1,4-polyisoprene.

[0168] Synthetic rubber may be chosen in particular from the group consisting of bromobutyl rubber, butyl rubber, polyisoprene rubber, polynorbornene rubber, ethylene-propylene rubber (EPR), ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), carboxylated nitrile rubber, polychloroprene rubber (neoprene rubber), polysulfide rubber, polyacrylic rubber, silicone rubber, chlorosulfonated polyethylene rubber, polybutadiene rubber, styrene-butadiene rubber (SBR), butyl rubbers (isobutylene-isoprene) or one of their mixtures. Among these, polyisoprene rubber, ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), polybutadiene rubber, styrene-butadiene rubber (SBR), butyl rubber (isobutylene-isoprene) and their mixtures are particularly preferred.

[0169] Examples of rubber blends include a blend of natural rubber and polybutadiene rubber, and a blend of natural rubber and styrene-butadiene rubber. Advantageously, the rubber contains less than 5%, preferably less than 2% by weight, of carboxylated nitrile rubber (XNBR). Advantageously, the rubber is not functionalized. Alternatively, it may be a rubber comprising branched nitrile rubber (NBR) and pre-crosslinked branched nitrile rubber (NBR), such as the products in the Chemigum powder range marketed by Synthomer, UK, or a rubber comprising a pre-crosslinked acrylate terpolymer, such as the products in the Sunigum powder range marketed by the same company.

[0170] According to one embodiment, the rubber is recycled rubber.

[0171] Preferably, the rubber is in powder form. This can include, in particular, ground cross-linked rubber. The powder preferably has a median volume diameter (Dv50) between 2 and 1000 µm, especially less than 850 µm, even more preferably less than 800 µm, and especially less than 750 µm. Dv50 corresponds to the particle size value that divides the particle volume exactly in half. A low Dv50 value improves the suitability for injection molding thin parts. Dv50 is measured according to ISO 13320:2020, using a Malvern Insitec laser particle size analyzer and RTSizer software. Rubber in powder form can be prepared using various methods. For example, rubber can be obtained by a grinding process.Various grinding processes exist such as, for example, mechanical grinding at room temperature, cryogenic grinding, grinding using water jets, or powder micronization.

[0172] According to another embodiment, a raw rubber can be used which is crosslinked in situ during the mixing process, in particular the compounding step.

[0173] Mixture of modifiers

[0174] According to some embodiments, the modifier in the composition of the invention is a combination of at least one thermoplastic elastomer as described above and at least one rubber as described above. More particularly, the modifier may be a mixture of at least one thermoplastic polyurethane and at least one rubber. Alternatively, the modifier may be a mixture of at least one styrene copolymer and at least one rubber.

[0175] Additives

[0176] The composition of the invention further comprises 0 to 5% by weight, preferably 0.1 to 2% by weight of additives relative to the total weight of the composition.

[0177] The additive(s) may be chosen from among the following: catalysts, antioxidants, thermal stabilizers, UV stabilizers, light stabilizers, lubricants, flame retardants, nucleating agents, crosslinking agents, anti-abrasion agents, chain extenders, pigments and dyes.

[0178] In a preferred embodiment, the composition comprises 0.05 to 0.2% by weight of one or more antioxidant and / or UV-stabilizing agents. Crosslinking additives are particularly useful when using raw rubber intended to be crosslinked during the mixing of the composition. Among the abrasion-resistant additives useful for improving abrasion resistance, high and ultra-high molecular weight polysiloxanes, especially in powder form, and dimethylsilicone in fluid form, are particularly noteworthy.

[0179] Advantageously, the composition contains less than 4%, and in particular less than 2% by weight of copolyolefins containing glycidyl methacrylate.

[0180] Charges

[0181] According to the invention, the composition also comprises 0 to 5% by weight, preferably 0.5 to 3% by weight of fillers relative to the total weight of the composition.

[0182] These fillers can include mineral or organic materials. Mineral fillers include metal oxides and carbonates such as silica, calcium carbonate, and zinc oxide; aluminum oxides, calcium carbonate, and aluminosilicates; as well as carbon black and molybdenum disulfide. Organic fillers include PTFE powder and aramid powder. Mineral fillers are preferred.

[0183] These fillers are generally in powder form but can also be in other forms, particularly as fibers. Preferably, the composition does not include glass fibers.

[0184] Fillers can be added to the composition separately or through other components, for example rubber. Indeed, rubber, especially when recycled, can contain up to 50%, specifically 2 to 30%, and particularly 3 to 10% by weight of fillers.

[0185] Some rubbers, particularly recycled ones, also contain carbon black. However, a high carbon black content leads to road marking during use. Therefore, the composition must have a carbon black content of less than 4%, specifically less than 2%, and in particular less than 1% by weight, for example, less than 0.5% by weight. The carbon black content is determined by TGA according to ISO 11358 by performing a dynamic test under nitrogen from 30 to 900°C at 10°C / min, followed by a 10-minute hold at 900°C in air to degrade the carbon derivatives. The amount of carbon black corresponds to the difference between the residue levels obtained at 900°C under nitrogen and at 900°C after air treatment. A. Composition

[0186] The composition of the invention as described above has a set of interesting properties, especially in comparison with rubber or TPU compositions.

[0187] Advantageously, the composition is homogeneous when examined with the naked eye, and forms a non-heterogeneous medium, for example non-porous.

[0188] The preferred composition is a flexible one, with a Shore hardness, as measured according to ISO 48-5:2018, of 10A to 100A, preferably 20A to 90A, and advantageously 40A to 85A. The hardness of the composition can be adjusted by choosing the PEBA and modifier. For example, the hardness can be decreased by choosing a softer PEBA and / or modifier. Conversely, the hardness can be increased by choosing a less flexible PEBA and / or modifier.

[0189] Furthermore, the composition exhibits high abrasion resistance, which is evidenced by a volume change after the test of less than 100 mm 3 , and in particular less than 90 mm 3 advantageously less than 80mm 3 .

[0190] The composition also exhibits good resistance to slippage on wet surfaces. Thus, its coefficient of dynamic friction, as measured according to the SATRA TM144 standard, is preferably greater than 0.2, and in particular greater than 0.25, advantageously greater than 0.3.

[0191] Preferably, the composition also produces a low or even zero ground marking, as measured according to the SATRA TM223 standard.

[0192] Similarly, the composition preferably exhibits damping, expressed by the tan delta, between 0.1 and 0.5, preferably between 0.2 and 0.4. Such a composition ensures both good ground adhesion and good responsiveness.

[0193] The tangent delta is measured on a film approximately 250 µm thick obtained by pressing the granules in a mold above their melting temperature under a 2T load. The test is performed by dynamic mechanical analysis (DMA) in tension according to ISO 6721, using a temperature sweep from -100 to 180°C at a rate of 2°C / min, a frequency of 1 Hz, and an amplitude of 20 µm. The tan delta value then corresponds to the maximum of the curve obtained. Furthermore, the composition of the invention is lighter than rubber and TPU. Generally, its density, as measured according to ISO 1183-1, is less than 1.1.

[0194] Advantageously, the composition of the invention also exhibits an elongation at break, as measured according to ISO 527, greater than 400%, particularly 500%, and especially 600%. Furthermore, the composition preferably has a melt flow index (MVI) greater than 5 cm⁻¹. 3 / 10min, especially above 10 cm 3 / 10 min, and especially greater than 15 cm 3 / 10 min. The melt flow index (MVI) is measured according to ISO 1133:2011-1 at 220°C under a 2.16 kg load on a material with a moisture content of less than 0.02%. Furthermore, the composition of the invention is also more tear-resistant than rubber. Advantageously, it exhibits a tear resistance, as measured according to ISO 34-1:2022, greater than 30 N / mm, preferably greater than 40 N / mm.

[0195] The composition of the invention lends itself easily to injection, and therefore allows in particular the manufacture of thin parts, and to overmolding, a process of interest in particular for the assembly of shoes, in particular of the insole with the outsole.

[0196] According to one embodiment, the composition of the invention does not require vulcanization and therefore allows for faster manufacturing than rubber.

[0197] Finally, the composition of the invention exhibits good recyclability compared to rubber, which does not allow recycling, and TPU, which tends to release isocyanates.

[0198] B. Manufacturing process for the composition

[0199] According to a second aspect, the invention relates to a method for manufacturing the composition according to the invention, comprising the steps of:

[0200] (a) Mix in a molten state, preferably in a twin-screw extruder or co-mixer: a. 55 to 99% by weight of polyether block amide (PEBA) having a number-average molar mass ratio of polyamide blocks to polyether blocks less than or equal to 1.0; b. 1 to 45% by weight of a modifier selected from: i. a thermoplastic elastomer in the form of a block copolymer with a number-average molar mass ratio D of rigid blocks to flexible blocks less than 0.8; ii. a rubber; and iii. combinations thereof; c. 0 to 5% of additives; and d. 0 to 5% by weight of fillers; the sum of the weight percentages of components (a) to (d) adding up to 100%, wherein the composition comprises less than 4% by weight of carbon black,

[0201] (b) optionally, shape the mixture into granules, filaments or powder, and

[0202] (c) retrieve the resulting composition.

[0203] The mixing stage of the process can be carried out by applying high shear, for example in an extruder, combined with heating or irradiation to ensure good dispersion of the molten components and thus obtain a homogeneous mixture. C. Use of the composition

[0204] According to yet another aspect, the invention aims at the use of the composition described above for the manufacture of shoe components, in particular shoe soles.

[0205] Given its good properties, including resistance to abrasion, slippage and its low marking on the ground, the composition appears particularly interesting for the manufacture of an outsole or wear sole.

[0206] Due to its good suitability for injection and overmolding, the composition also appears particularly useful for use in the assembly of soles comprising an insole and an outsole or wear sole.

[0207] D. Articles comprising the composition

[0208] According to yet another aspect, the invention relates to an article consisting of, or comprising at least one element consisting of, or comprising a composition as described above.

[0209] The said article is preferably selected from the group of footwear components, including running shoes, baseball, rugby, soccer, golf and American football shoes, such as soles, including outsoles and outsoles, cleats, including cleat tips, sports equipment parts such as ski pole parts, racket handles and covers, golf club handles, goalkeeper gloves, treadmills, aquatic equipment such as diving booties, mask and snorkel parts, spectacle frame parts (sleeve, temples, nose pads), ski mask frames, vibration isolation parts in electronics and machinery, external battery cases, automotive parts and wheel treads.

[0210] Insoles, especially outsoles or outer soles, are particularly preferred.

[0211] Articles or components made of a composition such as described above can be manufactured in particular by injection molding.

[0212] The outsole can have varying dimensions. In general, however, it preferably has a thickness between 0.1 and 30 mm, preferably between 0.5 and 20 mm, advantageously between 1 and 10 mm.

[0213] The sole may be decorated with patterns and / or studs.

[0214] The sole can be made of one or more parts. For example, the sole may consist of a central part (midsole) and an outer part (outsole). The outer part can then be assembled to the central part or be directly attached to the upper.

[0215] The assembly of the parts forming the sole and the sole to the rest of the shoe can be achieved through various methods, including stitching, gluing, heat bonding, or overmolding. Advantageously, the sole, consisting of an insole and an outsole, can be created by injection molding the outsole, used as an insert, with PEBA foam, the foam forming the insole.

[0216] E. Recycling

[0217] Advantageously, the composition of the invention is recyclable, after possible separation from other parts, grinding, and extrusion. The granules thus obtained can be reused for the manufacture of other articles.

[0218] In yet another aspect, the invention also relates to a method for recycling an article according to the invention, comprising the following successive steps: a) recovering, after possible separation, at least a portion of said article in thermoplastic material comprising a composition according to the invention; b) grinding the thermoplastic material to obtain particles; c) melting the particles to obtain a molten mixture; and d) optionally, adding other components to the molten mixture; and e) optionally, forming granules, filaments, or powders from the molten mixture obtained at the end of step c) or d); and f) optionally, shaping the granules, filaments, or powders. The invention will be explained in more detail in the examples that follow.

[0219] [EXAMPLES]

[0220] We prepared compositions using the following polymers:

[0221] PEBA 1: block copolymer of PA 11 (Mn= 600 g / mol) and PTMG (Mn= 1000 g / mol), with 62.5% PTMG, Shore hardness 90A.

[0222] PEBA 2: block copolymer of PA 12 (Mn= 600 g / mol) and PTMG (Mn= 2000 g / mol), with 76.9% PTMG of Shore 80 A hardness.

[0223] Elastomer 1: Styrene and ethylene / butylene (SE / BS) triblock copolymer containing 32.9% by weight of styrene and 1% by weight of maleic anhydride, with a Shore hardness of 63 A, sold by Kraton under the name Kraton MD6684 GS-N. D ratio between the Mn of the rigid blocks and the flexible blocks less than 0.5.

[0224] Elastomer 2: Triblock copolymer of styrene and ethylene / butylene (SE / BS) containing between 11.5 and 13.5% by weight of styrene, with a Shore hardness of 35 A, sold by Kraton under the name Kraton G1645 V. Ratio D between the Mn of the rigid blocks and the flexible blocks less than 0.2.

[0225] Elastomer 3: Triblock copolymer of styrene and ethylene / butylene (SE / BS) containing 13% by weight of styrene and 1% by weight of maleic anhydride, with a Shore hardness of 50 A, sold by Kraton under the name Kraton FG1924. Ratio D between the Mn of the rigid blocks and the flexible blocks less than 0.2.

[0226] Elastomer 4: Styrene and ethylene / butylene (SE / BS) triblock copolymer containing 28.6% styrene, Shore hardness 43 A, sold by Kraton under the name Kraton MD1542 V. Ratio D between the Mn of the rigid blocks and the flexible blocks less than 0.4.

[0227] Elastomer 5: A triblock copolymer of styrene and ethylene / butylene (SE / BS) containing 34% by weight of styrene and between 0.8 and 2% by weight of grafted maleic anhydride, with a Shore hardness of 48 A, sold by Kraton under the name Kraton MD6186 GO. The D ratio between the Mn of the rigid blocks and the flexible blocks is less than 0.6.

[0228] Elastomer 6: Styrene-ethylene / propylene linear block copolymer, Shore 64 A hardness, sold by LCY under the name Globalprene SEP8501U. D ratio between the Mn of the rigid blocks and the flexible blocks less than 0.6.

[0229] Elastomer 7: Thermoplastic polyurethane marketed by Covestro under the name Desmopan 6064A, with a Shore hardness of 67 A. Ratio D between the Mn of the rigid blocks and the flexible blocks less than 0.8.

[0230] Elastomer 8: saturated styrene / isobutylene / styrene (SIBS) block copolymer, Shore 35 A hardness, sold by Kaneka under the name Sibstar 062T-FD. D ratio between the Mn of the rigid blocks and the flexible blocks less than 0.8.

[0231] Rubber 1: Rubber powder from used tires (D50 = 160 pm; D90 = 340 pm) marketed by Tyre Recycling Solutions under the name TyreXol® CW 50 which contains between 5 and 17% carbon black.

[0232] Rubber 2: Polybutadiene marketed by Eni Versalis under the name Europrene® NEOCIS BR 60.

[0233] Additive 1: silicone powder consisting of silica compounded with polydimethylsiloxane marketed by Dow under the name Dowsil Trefil F-202.

[0234] Additive 2: Crosslinking agent.

[0235] Additive 3: Statistical copolymer of ethylene, acrylic ester and glycidyl methacrylate marketed by SK Chemicals under the name Lotader® AX8900.

[0236] Various compositions were produced by mixing polymers using a ZSK26 twin-screw extruder. The barrel temperature was set at 190°C. The screw speed was set at 200 rpm with a throughput of 15 kg / h. The quantity of the different ingredients as mass percentages relative to the mass of the final composition is shown in Table 1 below. Example EC2 was produced by mixing PEBA and rubber powder in a Buss PR46 co-mixer at a throughput of 15 kg / h and a co-mixing speed of 250 rpm.

[0237] The compositions, in granular form, are then dried under reduced pressure at 70°C to achieve a moisture content of less than 0.08% by mass. Except for the compositions in the comparative examples, the compositions have a homogeneous appearance and a natural color when examined with the naked eye. Comparative examples EC1 and EC2 are black. [Table 1]: Composition of the examples

[0238] From the compositions manufactured in granular form, blocks with a diameter of 16 mm and a thickness of 6 mm were molded into 100x100x2 mm plates 3 and 200x200x0.4mm plates 3 by injection molding using a Battenfeld BA800 CDC press with unpolished molds and the following injection parameters:

[0239] - Sheath temperature: 170-190°C

[0240] - Nozzle temperature: 190°C

[0241] - Mold temperature: 20°C

[0242] - Cycle time: 60 seconds. Type 1BA shaped test specimens with a thickness of 0.4 mm are obtained using a die from 200x200x0.4 mm plates. 3in order to replicate the maximum elongation supported by a 0.4mm thick sole. The compositions were evaluated in terms of appearance after abrasion, elongation at break, ground marking and suitability for injection according to the following test protocols.

[0243] (a) Abrasion resistance

[0244] The abrasion resistance of the compositions is measured according to DIN ISO 4649:2017 (method B with rotating specimen holder) on injection-molded pads with a diameter of 16 mm and a thickness of 6 mm. Abrasion resistance is expressed as the volume change before and after the test. A composition is considered satisfactory when the volume change is less than 100 mm 3 The results are summarized in Table 2 below.

[0245] (b) Appearance after abrasion

[0246] The appearance of the compositions after abrasion is assessed by visual inspection. The abrasiond pad must be free of filaments, and the pad's contour at the abraded area must be smooth, with no material overhang exceeding 0.01 mm. The appearance of the pads after testing is rated as satisfactory (+) or unsatisfactory (-). The results are summarized in Table 2 below.

[0247] (c) Elongation at break in tension

[0248] The 0.4 mm thick 1BA test specimens are conditioned for 14 days at 50% relative humidity and a temperature of 23°C, and their elongation at break is then measured at 200 mm / min, following the ISO 527 standard for all other aspects. The elongation at break thus measured, required for the application, must be greater than or equal to 150%. The results are summarized in Table 2 below.

[0249] (d) Ground markings

[0250] The tendency of a composition to leave marks on floors is evaluated according to the SATRA TM223 method. The result is considered satisfactory (+) if the material, after being subjected to the abrasion test according to ISO 4649:2017, method B, does not leave a black mark on a white floor covering, and unsatisfactory (-) if the material creates a black mark on the covering. The results are summarized in Table 2 below.

[0251] (e) Ability to inject

[0252] The injectability of the composition is assessed by measuring the flow length on an injection molding machine equipped with a mirror-polished spiral mold (spiral flow test) with the following parameters:

[0253] • Mold temperature: 40°C

[0254] • Material holding pressure: 900 bars

[0255] • Temperature profile: 170 / 200 °C

[0256] • Flow rate: 57 cm 3 / s

[0257] • Cooling time: 20 s. The test is performed by injecting the molten composition through the central core, which directly feeds the 20 mm wide, 1 mm thick spiral with a maximum length of 1280 mm. There is a 10 mm gap between the walls of the spiral channels. The average flow length of ten tests performed for each sample is reported in Table 2 below. (f) Slip resistance on wet ground

[0258] The resistance to slipping on wet ground is determined by measuring the coefficient of dynamic friction.

[0259] Samples are prepared by cutting 50mm x 50mm x 2mm plates from the injection-molded plates using a die. The plates are then beveled on two sides on a glazing bench. They are then laminated onto rigid PVC sheets and cleaned with a 1:1 volume mixture of demineralized water and ethanol. The dynamic friction coefficient of the samples is then measured on standard STM 603AQ clay tiles wetted with demineralized water, laid flat under a vertical load of 500N at a speed of 50mm / min and up to an elongation of 25mm, according to the SATRA TM 144:2011 procedure. A satisfactory composition exhibits a dynamic friction coefficient greater than 0.2. The results are summarized in Table 2 below.

[0260] [Table 2]: Results of the composition evaluation These experimental results highlight that the compositions according to the invention have a better appearance after abrasion than the comparative examples EC1 and EC2.

[0261] These compositions according to the invention also exhibit excellent injection-molding properties, making it possible to manufacture thinner, lighter soles and thus lighter shoes. Furthermore, they demonstrate a tensile elongation at break exceeding 150% on a 0.4 mm thick piece, representative of a running shoe, which is highly satisfactory.

[0262] Finally, it was verified that these compositions do not produce any markings on the ground.

[0263] In contrast, the compositions according to the comparative examples exhibit an unsatisfactory appearance after abrasion (see FIG. 1) and a lower elongation at break. They also leave marks on the ground and are less suitable for injection. Comparative example 2 is also less abrasion-resistant than the compositions according to the invention, and comparative example 1 has a coefficient of dynamic friction that is too low for the intended application. [List of cited documents]

[0264] US 2009 / 0292073 Al

[0265] US 2005 / 0004326 Al

[0266] US 8,013,251 B2

[0267] US 2017 / 0242372 Al

Claims

DEMANDS 1. Polymer composition comprising: (a) 55 to 99%, preferably 60 to 95%, advantageously 65 to 90%, and in particular 70 to 85% by weight of at least one polyether block amide (PEBA) having a number-average molar mass ratio of polyamide blocks to polyether blocks less than or equal to 1.0, preferably less than 0.8; (b) 1 to 45%, preferably 5 to 40%, advantageously 10 to 35% and in particular 15 to 30% by weight of at least one modifier selected from: i. at least one thermoplastic elastomer in the form of a block copolymer with a number-average molar mass ratio D of the rigid blocks and the flexible blocks less than 0.8, preferably less than 0.7 and advantageously less than 0.5; ii. at least one rubber, raw or crosslinked; and iii. combinations thereof; (c) 0 to 5%, preferably 0.1 to 4%, including 1 to 2% by weight of additives; and (d) 0 to 5%, preferably 0.5 to 3% by weight of fillers, the sum of the percentages of components (a) to (d) adding up to 100%, and in which the composition comprises less than 4%, preferably less than 2%, advantageously less than 1% by weight of carbon black.

2. Composition according to claim 1, having a Shore hardness of 10A to 100A, preferably from 20A to 90A, and in particular from 40A to 85A.

3. Composition according to claim 1 or 2, wherein at least one PEBA comprises polyamide blocks selected from the group consisting of PA 6, PA 10, PA 11, PA 12, PA 54, PA 59, PA 510, PA 512, PA 513, PA 514, PA 516, PA 518, PA 536, PA 64, PA 66, PA 69, PA 610, PA 612, PA 613, PA 614, PA 616, PA 618, PA 636, PA 912, PA 104, PA 109, PA 1010, PA 1012, PA 1013, PA 1014, PA 1016, PA 1018, PA 1036, PA 10T, PA 124, PA 129, PA 1210, PA 1212, PA 1213, PA 1214, PA 1216, PA 1218, PA 1236, PA 12T or their copolymers.

4. Composition according to any one of claims 1 to 3, wherein at least one PEBA comprises polyether blocks selected from the group consisting of PEG (polyethylene glycol) blocks, PPG (polypropylene glycol) blocks, PO3G (polytrimethylene glycol) blocks and PTMG (polytetramethylene glycol) blocks.

5. Composition according to any one of claims 1 to 4, wherein at least one PEBA comprises PA 11 and PTMG blocks or PA 12 and PTMG blocks.

6. Composition according to any one of claims 1 to 5, wherein where at least one modifier is a thermoplastic elastomer, it is selected from thermoplastic polyurethanes (TPU) and styrene copolymers.

7. Composition according to any one of claims 1 to 5, wherein where at least one modifier is a rubber, it is selected from the group consisting of polyisoprene rubber, ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), polybutadiene rubber, styrene-butadiene rubber (SBR), butyl rubber (isobutylene-isoprene) and any mixture thereof.

8. Composition according to any one of claims 1 to 5 or 7, wherein where at least one modifier is a rubber, it is dispersed in the composition in the form of nodules of average diameter in number less than 850 pm, preferably less than 800 pm, advantageously less than 750 pm.

9. A method for manufacturing the composition according to claims 1 to 8, comprising the steps of: (i) mix in a molten state, preferably in a twin-screw extruder or in a co-mixer: (a) 55 to 99% by weight of at least one polyether block amide (PEBA) having a number-average molar mass ratio of polyamide blocks and polyether blocks less than or equal to 1.0; (b) 1 to 45% by weight of at least one modifier selected from: i. at least one thermoplastic elastomer in the form of a block copolymer with a number-average molar mass ratio D of rigid blocks to flexible blocks of less than 0.8; and ii. at least one rubber, raw or crosslinked; and iii. combinations thereof; (c) 0 to 5% by weight of additives; and (d) 0 to 5% by weight of fillers; the sum of the percentages by weight of components (a) to (d) adding up to 100%, in which the composition comprises less than 4% carbon black, (ii) optionally, shape the mixture into granules, filaments, or powder; and (iii) retrieve the resulting composition.

10. Use of the composition according to any one of claims 1 to 8 for the manufacture of an article selected from the group consisting of shoe components, sports equipment parts, treadmills, aquatic equipment, spectacle frame parts, ski mask frames, vibration isolation parts in electronics and on machinery, external battery cases, automotive parts and wheel treads.

11. Use according to claim 10, wherein the composition is used for the manufacture of an outsole or an outsole.

12. Method for manufacturing an article comprising shaping a composition according to any one of claims 1 to 8.

13. Article comprising the composition according to any one of claims 1 to 8, selected from the group consisting of shoe components, sports equipment parts, treadmills, aquatic equipment, spectacle frame parts, ski mask frames, vibration isolation parts in electronics and on machinery, external battery cases, automotive parts and wheel treads.

14. Article according to claim 13, which is a wear sole or an outsole.

15. A method for recycling an article according to claim 13 or 14, comprising the following successive steps: (i) recovery, after possible separation, of at least a part of said article in thermoplastic material comprising a composition according to the invention; (ii) grinding of the thermoplastic material to obtain particles, (iii) melting of the particles to obtain a molten mixture, and (iv) optionally, adding other components to the molten mixture, and (v) optionally, the formation of granules, filaments or powders from the molten mixture obtained at the end of step iii) or iv), and (vi) optionally, shaping of granules, filaments or powders.

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