EP4214265A1

EP4214265A1 - Composition comprising a copolymer containing polyamide blocks and polyether blocks

Info

Publication number: EP4214265A1
Application number: EP21785955.2A
Authority: EP
Inventors: Blandine Testud; Quentin Pineau; Florent ABGRALL; Clio COCQUET
Original assignee: Arkema France SA
Current assignee: Arkema France SA
Priority date: 2020-09-15
Filing date: 2021-09-15
Publication date: 2023-07-26
Also published as: KR20230066568A; CN116249731A; US20230357481A1; FR3114098B1; FR3114098A1; WO2022058680A1; JP2023541535A; TW202219141A

Abstract

The invention relates to a composition comprising a copolymer containing polyamide blocks and polyether blocks having at least one carboxylic acid chain end reacted with an epoxide function, to a process for manufacturing same, and to the use thereof. The invention also relates to a foam formed from said composition, to a process for manufacturing same, and to the use thereof.

Description

DESCRIPTION

TITLE: Composition comprising a copolymer with polyamide blocks and with polyether blocks

Field of invention

The present invention relates to a composition comprising a copolymer with polyamide blocks and with polyether blocks comprising at least one end of the carboxylic acid chain having reacted with an epoxide function, its method of preparation and its use. The invention also relates to a foam formed from this composition, its method of preparation and its use.

Technical background

Various copolymers with polyamide blocks and with polyether blocks are used in particular in the field of sports equipment, such as soles or components of soles, gloves, rackets or golf balls, individual protection elements in particular for the practice of sport ( vests, interior parts of helmets, shells, etc.), thanks to their mechanical properties and in particular their excellent springback property. Indeed, these copolymers can be advantageously used in sports shoes as a sole of the semi-rigid or flexible type making it possible to produce the inner sole and/or the outer sole directly.

However, it has been observed that copolymers with polyamide blocks and with polyether blocks, more particularly the so-called soft copolymers, generally having a hardness of less than 55 Shore D, have limitations in terms of mechanical strength, typically abrasion resistance. , tear strength and compressive strength.

They can also have limits in terms of adhesion when combined with other materials such as polyurethane thermoplastics in the production of multilayer structures by overmolding processes.

There is a continued demand in the market for higher performing materials, i.e. materials with improved strength properties mechanical properties, in particular abrasion resistance, tear resistance and compressive strength.

The object of the present invention is therefore to provide compositions based on copolymers with polyamide blocks and with particular polyether blocks having one or more advantageous properties sought from among good properties of mechanical resistance, in particular resistance to abrasion, resistance to tear and compressive strength, and better adhesion when overmolding.

Summary of the invention

The invention relates firstly to a composition comprising a copolymer with polyamide blocks and with polyether blocks (PEBA copolymer) comprising an end of the carboxylic acid chain of the polyamide block blocked by an epoxide function carried by an epoxide compound whose number-average functionality ( Efn) is greater than 2, preferably greater than or equal to 3, and whose epoxide equivalent weight (EEW) is from 80 to 700 g/mol, said composition having a complex viscosity (q*) which follows a law of power as defined by the following equation: q* = K (œ) ⁿ - ¹ (I) in which:

- K is a constant;

- oo is the angular frequency applied in oscillatory rheometry in the linear domain at a temperature 30°C above the melting point of the composition according to ISO 6721-10; and

- the value of n is between 0.55 and 0.95, preferably between 0.60 and 0.90, even more preferably between 0.65 and 0.85, or even between 0.70 and 0.85, on the range of angular frequencies oo comprised between 0.135 and 1.35 rad/s.

In the context of the present invention, the melting point is measured by differential scanning calorimetry (DSC) with a heating rate of 20° C./min according to ISO 11357-1.

According to one embodiment, the polymer composition according to the invention has a weight-average molar mass (Mw) ranging from 80,000 to 300,000 g/mol, preferably from 90,000 to 250,000 g/mol, more preferably from 100,000 to 200,000 g/mol. According to one embodiment, the ratio of the weight-average molar mass (Mw) of the composition to the number-average molar mass (Mn) of the composition is greater than or equal to 2.4.

According to one embodiment, the ratio of the z-average molar mass (Mz) of the composition to the weight-average molar mass (Mw) of the composition is greater than or equal to 2, preferably greater than or equal to 2.5 .

According to one embodiment, the polyamide (PA) blocks of the PEBA copolymer are chosen from blocks of PA 6, PA 11, PA 12, PA 5.4, PA 5.9, PA 5.10, PA 5.12, PA 5.13, PA 5.14, PA 5.16, PA 5.18, PA 5.36, PA 6.4, PA 6.9, PA 6.10, PA 6.12, PA 6.13, PA 6.14, PA 6.16, PA 6.18, from PA 6.36, from PA 10.4, from PA

10.9, PA 10.10, PA 10.12, PA 10.13, PA 10.14, PA 10.16, PA 10.18, PA 10.36, PA .T, PA 12.4, PA 12.9, PA

12.10, PA 12.12, PA 12.13, PA 12.14, PA 12.16, PA 12.18, PA 12.36, PA 12.T, mixtures thereof, or copolyamides thereof, preferably PA 11, 12 , 6, 6.10, 6.12, 10.10, 10.12 or mixtures thereof.

According to one embodiment, the polyether blocks of the PEBA copolymer are chosen from blocks of polyethylene glycol (PEG), propylene glycol (PPG), polytrimethylene glycol (PO3G), polytetrahydrofuran (PTMG), or mixtures thereof. ci, or copolymers thereof, preferably of polyethylene glycol or polytetrahydrofuran.

According to one embodiment:

- the polyamide blocks of the PEBA copolymer have a number-average molar mass of 400 to 20,000 g/mol, preferably of 500 to 10,000 g/mol; and or

- the polyether blocks of the PEBA copolymer have a number-average molar mass of 100 to 6000 g/mol, preferably of 200 to 3000 g/mol.

According to one embodiment, the mass ratio of the polyamide blocks relative to the polyether blocks of the PEBA copolymer is from 0.1 to 20, preferably from 0.3 to 10, or from 0.3 to 5, or even more preferably from 0.3 to 1. In the context of the present invention, the number-average epoxy functionality (Efn) of the epoxy compound is greater than 2, advantageously greater than or equal to 3, and possibly up to 30. Preferably, the functionality (Efn) is 3 to 20.

According to one embodiment, the epoxy equivalent weight (EEW) of the epoxy compound is 80 to 700 g/mol, preferably 80 to 100 g/mol, or 100 to 200 g/mol, or 200 to 300 g/mol, or 300 to 400 g/mol, or 400 to 500 g/mol, or 500 to 600 g/mol, or 600 to 700 g/mol.

It has been observed that the composition of the invention has a thermoplastic character and is recyclable.

The present invention therefore provides a new type of composition, which in particular has improved mechanical strength, while having excellent recyclability properties.

This is accomplished through the use of a polyamide block and polyether block copolymer branched by a particular epoxy compound, having a particular complex viscosity.

The composition may also comprise at least one component (C) chosen from polyamides, functional polyolefins, copolyetheresters, thermoplastic polyurethanes (TPU), copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylate , and copolymers of ethylene and alkyl (meth)acrylate, and/or one or more additives (D) chosen from nucleating agents, fillers, in particular mineral fillers, such as talc, reinforcing fibers, in particular of glass or carbon, colorants, UV absorbers, antioxidants, in particular phenolic, or phosphorus-based or sulfur-based, light stabilizers of hindered amine or HALS type, and mixtures thereof.

According to one embodiment, the melting point of the composition corresponds to the melting point of the PEBA copolymer.

In the case where several PEBA copolymers are present in the composition, the melting point of the composition corresponds to the highest melting point of the PEBA copolymers. In the case where one or more components (C) are present in the composition, the melting point of the composition corresponds to the highest melting point of the PEBA copolymer(s) and of the component(s) (C ).

According to one embodiment, the composition comprises from 0 to 49%, preferably from 0.1 to 49% by weight of at least one component (C) chosen from polyamides, functional polyolefins, copolyetheresters, thermoplastic polyurethanes (TPU), copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylate, and copolymers of ethylene and alkyl (meth)acrylate, and/or from 0 to 10%, preferably from 0.1 to 10% by weight of one or more additives (D) chosen from nucleating agents, fillers, reinforcing fibers, dyes, UV absorbers, antioxidants, light stabilizers, and mixtures thereof, on the total weight of the composition.

The invention also relates to a process for manufacturing a composition as described above, comprising a step of mixing, typically in the molten state, a PEBA copolymer, an epoxy compound whose equivalent weight of epoxide (EEW) is 80 to 700 g/mol, optionally of one or more components (C) and/or of one or more additives (D), so that at least one end of the carboxylic acid chain of the copolymer PEBA reacts with an epoxy function of the epoxy compound, said composition having a complex viscosity (q*) which follows a power law as defined by the following equation: q* = K (œ) ⁿ - ¹ (I) in which :

- K is a constant;

- the value of n is between 0.55 and 0.95, preferably between 0.60 and 0.90, even more preferably between 0.65 and 0.85, or even between 0.70 and 0.85, on the range of angular frequencies oo comprised between 0.135 and 1.35 rad/s. The PEBA copolymer typically has a content at the end of the carboxylic acid chain of 10 to 200 pmol/g, preferably between 15 and 150 pmol/g, for example between 20 and 100 pmol/g.

The epoxy equivalent weight (EEW) of the epoxy compound is 80 to 700 g/mol, preferably 80 to 100 g/mol, or 100 to 200 g/mol, or 200 to 300 g/mol, or 300 at 400 g/mol, or 400 to 500 g/mol, or 500 to 600 g/mol, or 600 to 700 g/mol.

According to one embodiment, the molar ratio of the content at the end of the carboxylic acid chain of the PEBA copolymer to the content of epoxide function of the epoxide compound is typically between 2 and 20, preferably between 3 and 10.

According to one embodiment, the quantity of the epoxy compound used in the process is from 0.01 to 5% by weight, preferably from 0.01 to 2% by weight, more preferably from 0.05 to 1% by weight , relative to the total weight of the PEBA copolymer.

According to a preferred embodiment, the amount of epoxy compound used in the process is less than 1%, typically from 0.15 to 0.95%, preferably from 0.3 to 0.9%, or even from 0. 35 to 0.85% by weight relative to the total weight of the PEBA copolymer.

The invention also relates to a composition which can be obtained according to the aforementioned process.

The present invention also relates to a foam of a composition as described above.

According to one embodiment, the foam has a density less than or equal to 800 kg/m ³ , preferably less than or equal to 600 kg/m ³ , more preferably less than or equal to 400 kg/m ³ , even more preferably less than or equal to equal to 300 kg/m ³ .

According to embodiments, the foam has a residual deformation under compression (50% deformation applied for 6 hours at 50° C., measured according to the ISO 7214:2012 standard, after 30 minutes of relaxation) less than or equal to 65%, of preferably less than or equal to 50%, or less than or equal to 45%, or 40%, or 35%. The present invention provides a composition having improved foamability and allowing the formation of a regular, homogeneous polymer foam, having a low density and having one or more advantageous properties among: a high capacity to restore elastic energy during stresses under low stress; low residual deformation in compression (and therefore improved durability); high resistance to fatigue in compression; excellent resilience properties, and in particular resistance to abrasion.

One of the advantages of the composition of the invention used in the foam according to the invention is that it exhibits thermoplastic, non-crosslinked behavior. Thus, the foam according to the invention is a non-crosslinked foam, having the advantage of being recyclable.

The present invention also relates to the use of at least one epoxy compound as defined above in a PEBA block copolymer as defined above to improve the ability of said copolymer to be transformed into foam while maintaining its recyclability.

The invention also relates to an article consisting of or comprising at least one element consisting of a composition as described above.

The invention also relates to an article consisting of or comprising at least one element consisting of a composition, typically a foam as described above.

Advantageously, the article according to the invention is chosen from: a fiber, a fabric, a film, a sheet, a foam plate, a foam particle, a rod, a tube, an injected and/or extruded part.

Advantageously, the article according to the invention is chosen from: shoe soles, footballs or balls, gloves, personal protective equipment, soles for rails, automobile parts, construction parts and parts for electrical and electronic equipment, for example, the article is chosen from a shoe sole, in particular for sports, such as an insole, midsole, or outsole, a ski boot, a sock, a racket, a ball , a ball, a float, gloves, personal protective equipment, a helmet, rail pad, automobile part, stroller part, tire, wheel, smooth-rolling wheel like a tire, handle, seat part, child car seat part, part of construction, a piece of electrical and/or electronic equipment, a piece of electronic protection, a piece of audio equipment, acoustic and/or thermal insulation, a piece intended to dampen shocks and/or vibrations, such as than those generated by a means of transport, an element of padding, a toy, a medical object, such as a splint, an orthosis, a cervical collar, a dressing, in particular an antimicrobial foam dressing, an object of art or crafts, life jackets, backpacks, membranes, rugs, sports mats, sports flooring, carpet padding, and any item comprising a mixture of these items.

detailed description

The invention is now described in more detail and in a non-limiting manner in the description which follows.

Unless otherwise indicated, all percentages are mass percentages.

Composition

The composition of the invention comprises a copolymer with polyamide blocks and with polyether blocks comprising at least one end of the carboxylic acid chain having reacted with an epoxide function.

In the context of the present invention, three types of polyamide blocks can advantageously be used for the PEBA copolymer.

According to a first type, the polyamide blocks come from the condensation of an aliphatic, linear or branched, cycloaliphatic or aromatic dicarboxylic acid, in particular those having from 4 to 36 carbon atoms, preferably those having from 6 to 18 carbon atoms , and an aliphatic, linear or branched, cycloaliphatic or alkylaromatic diamine, in particular those having from 2 to 20 carbon atoms, preferably those having from 4 to 14 carbon atoms. According to one embodiment, the polyamide blocks come from the condensation of an aliphatic, linear or branched, cycloaliphatic or aromatic dicarboxylic acid and an aliphatic, linear or branched, or cycloaliphatic diamine.

According to one embodiment, the polyamide blocks come from the condensation of an aliphatic, linear or branched or cycloaliphatic dicarboxylic acid and an aliphatic, linear or branched, or cycloaliphatic diamine.

As examples of dicarboxylic acids, mention may be made of 1,4-cyclohexyldicarboxylic acid, butanedioic, adipic, azelaic, suberic, sebacic, dodecanedicarboxylic, octadecanedicarboxylic acids and terephthalic and isophthalic acids, but also dimerized fatty acids .

As examples of diamines, mention may be made of tetramethylene diamine, hexamethylenediamine, 1,10-decamethylenediamine, dodecamethylenediamine, trimethylhexamethylenediamine, isomers of bis-(4-aminocyclohexyl)-methane (BACM), bis -(3-methyl-4- aminocyclohexyl)methane (BMACM), and 2-2-bis-(3-methyl-4- aminocyclohexyl)-propane (BMACP), para-amino-di-cyclo-hexyl-methane ( PACM), isophoronediamine (IPDA), 2,6-bis-(aminomethyl)-norbornane (BAMN) and piperazine (Pip).

Advantageously, polyamide blocks PA 4.12, PA 4.14, PA 4.18, PA 6.10, PA 6.12, PA 6.14, PA 6.18, PA 9.12, PA 10.10, PA 10.12, PA 10.14 and PA 10.18 are used. In the notation PA X.Y, X represents the number of carbon atoms resulting from the diamine residues, and Y represents the number of carbon atoms resulting from the diacid residues, in the conventional way.

According to a second type, the polyamide blocks result from the condensation of one or more a,oo-aminocarboxylic acids and/or of one or more lactams having from 6 to 12 carbon atoms in the presence of a dicarboxylic acid having from 4 with 36 carbon atoms or a diamine. As examples of lactams, mention may be made of caprolactam, oenantholactam and lauryllactam. As examples of a,oo-amino carboxylic acid, one can mention aminocaproic, amino-7-heptanoic, amino-11-undecanoic and amino-12-dodecanoic.

Advantageously, the polyamide blocks of the second type are blocks of PA 11 (polyundecanamide), of PA 12 (polydodecanamide) or of PA 6 (polycaprolactam). In PA X notation, X represents the number of carbon atoms from amino acid residues.

According to a third type, the polyamide blocks result from the condensation of at least one a,oo-aminocarboxylic acid (or a lactam), at least one diamine of the aforementioned type and at least one dicarboxylic acid of the aforementioned type.

In this case, the polyamide PA blocks are prepared by polycondensation:

- the diamine(s) having X carbon atoms;

- dicarboxylic acid(s) having Y carbon atoms; and

- comonomer(s) {Z}, chosen from lactams and a,oo-aminocarboxylic acids having Z carbon atoms and equimolar mixtures of at least one diamine having X1 carbon atoms and at least one dicarboxylic acid having Y1 carbon atoms, (X1 , Y1 ) being different from (X, Y),

- said {Z} comonomer(s) being introduced in a proportion by weight advantageously ranging up to 50%, preferably up to 20%, even more advantageously up to 10% relative to all of the polyamide precursor monomers;

- in the presence of a chain limiter chosen from dicarboxylic acids.

Advantageously, the dicarboxylic acid having Y carbon atoms is used as chain limiter, which is introduced in excess relative to the stoichiometry of the diamine(s).

According to a variant of this third type, the polyamide blocks result from the condensation of at least two a,oo-aminocarboxylic acids or of at least two lactams having from 6 to 12 carbon atoms or of a lactam and of a aminocarboxylic acid not having the same number of carbon atoms in the optional presence of a chain limiter. Mention may be made, as examples of aliphatic α,oo-aminocarboxylic acid, of aminocaproic, amino-7-heptanoic, amino-11-undecanoic and amino-12-dodecanoic acids. As examples of lactam, mention may be made of caprolactam, oenantholactam and lauryllactam. As examples of aliphatic diamines, mention may be made of hexamethylenediamine, dodecamethylenediamine and trimethylhexamethylenediamine. As examples of cycloaliphatic diacids, mention may be made of 1,4-cyclohexyldicarboxylic acid. As examples of aliphatic diacids, mention may be made of butane-dioic, adipic, azelaic, suberic, sebacic, dodecanedicarboxylic acids, dimerized fatty acids. These dimerized fatty acids preferably have a dimer content of at least 98%; preferably they are hydrogenated; these are, for example, products marketed under the "PRIPOL" brand by the "CRODA" company, or under the EMPOL brand by the BASF company, or under the Radiacid brand by the OLEON company, and polyoxyalkylene a,oo-diacids . As examples of aromatic diacids, mention may be made of terephthalic (T) and isophthalic (I) acids. As examples of cycloaliphatic diamines, mention may be made of 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), and para-amino-di-cyclo-hexyl-methane (PACM). Other commonly used diamines can be isophoronediamine (IPDA), 2,6-bis-(aminomethyl)-norbornane (BAMN), and piperazine.

By way of examples of polyamide blocks of the third type, the following may be mentioned:

- PA 6.6/6, where 6.6 denotes hexamethylenediamine units condensed with adipic acid and 6 denotes units resulting from the condensation of caprolactam;

- PA 6.6/6.10/11/12, where 6.6 denotes hexamethylenediamine condensed with adipic acid, 6.10 denotes hexamethylenediamine condensed with sebacic acid, 11 denotes units resulting from the condensation of aminoundecanoic acid and 12 denotes units resulting from the condensation of lauryllactam.

The notations PA X/Y, PA X/Y/Z, etc. refer to copolyamides in which X, Y, Z, etc. represent homopolyamide units as described above.

Advantageously, the polyamide blocks of the copolymer used in the invention comprise polyamide blocks PA 6, PA 11, PA 12, PA 5.4, PA 5.9, PA 5.10, PA 5.12, PA 5.13, PA 5.14, PA 5.16, PA 5.18, PA 5.36, PA 6.4, PA 6.9, PA 6.10, PA 6.12, PA 6.13, PA 6.14, PA 6.16, PA 6.18, PA 6.36 , PA 10.4, PA 10.9, PA 10.10, PA 10.12, PA 10.13, PA 10.14, PA 10.16, PA 10.18, PA 10.36, PA 10.T, PA 12.4, PA 12.9, PA 12.10, PA 12.12, PA 12.13, PA 12.14 , PA 12.16, PA 12.18, PA 12.36, PA 12.T, or mixtures or copolymers thereof; and preferably comprise blocks of polyamide PA 6, PA 11, PA 12, PA 6.10, PA 10.10, PA 10.12, or mixtures or copolymers of these.

According to one embodiment, the polyamide blocks do not include aromatic units.

The polyether blocks consist of alkylene oxide units.

The polyether blocks may in particular be PEG (polyethylene glycol) blocks, i.e. consisting of ethylene oxide units, and/or PPG (polypropylene glycol) blocks, i.e. consisting of propylene oxide units, and/ or PO3G (polytrimethylene glycol) blocks, ie consisting of trimethylene ether glycol units, and/or PTMG (polytetramethylene glycol) blocks, ie consisting of tetramethylene glycol units also called polytetrahydrofuran. The copolymers can comprise in their chain several types of polyethers, the copolyethers possibly being block or random.

It is also possible to use blocks obtained by oxyethylation of bisphenols, such as for example bisphenol A. These latter products are described in particular in document EP 613919.

According to one embodiment, the polyether blocks do not include polyether blocks derived from ethoxylated bisphenol.

The polyether blocks can also consist of ethoxylated primary amines. By way of example of ethoxylated primary amines, mention may be made of the products of formula: [Chem 1] in which m and n are integers between 1 and 20 and x an integer between 8 and 18. These products are for example commercially available under the brand NORAMOX® from the company ARKEMA and under the brand GENAMIN® from the company CLARIFYING.

The polyether blocks can include polyoxyalkylene α,o-dihydroxylated aliphatic OH chain-ended blocks (called polyether diols).

The polyether blocks can comprise polyoxyalkylene blocks with diamine NH 2 chain ends (called polyetheramine), such blocks being able to be obtained by cyanoacetylation of polyoxyalkylene α,o-dihydroxylated aliphatic blocks called polyetherdiols. More particularly, the commercial products Jeffamine or Elastamine can be used (for example Jeffamine® D400, D2000, ED 2003, XTJ 542, commercial products from the company Huntsman, also described in the documents JP 2004346274, JP 2004352794 and EP 1482011).

According to one embodiment, the polyether blocks in the copolymer are polyetherdiols.

The polyetherdiol blocks are either used as such and copolycondensed with polyamide blocks with carboxyl ic ends, or aminated to be transformed into polyether diamines and condensed with polyamide blocks with carboxyl ic ends.

If the block copolymers described above comprise at least one polyamide block and at least one polyether block as described above, the present invention also covers copolymers comprising three, four (or even more) different blocks, provided that these blocks comprise at least polyamide and polyether blocks.

For example, the copolymer according to the invention can be a segmented block copolymer comprising three different types of blocks (or “triblock”), which results from the condensation of several of the blocks described above. Said triblock may for example be a copolymer comprising a polyamide block, a polyester block and a polyether block or a copolymer comprising a polyamide block and two different polyether blocks, for example a PEG block and a PTMG block.

PEBA copolymers result from the polycondensation of polyamide blocks with reactive ends with polyether blocks with reactive ends, such as, among others, the polycondensation:

I) polyamide blocks with diamine chain ends with polyoxyalkylene blocks with dicarboxylic chain ends;

2) polyamide blocks with dicarboxylic chain ends with polyoxyalkylene blocks with diamine chain ends, obtained for example by cyanoethylation and hydrogenation of aliphatic polyoxyalkylene a,o-dihydroxylated blocks called polyetherdiols;

3) polyamide blocks with dicarboxylic chain ends with polyetherdiols, the products obtained being, in this particular case, polyetheresteramides.

Preferably, the PEBA copolymers result from the polycondensation of polyamide blocks with dicarboxylic chain ends with polyetherdiols.

The polyamide blocks with dicarboxylic chain ends come, for example, from the condensation of polyamide precursors in the presence of a chain-limiting dicarboxylic acid. The polyamide blocks with diamine chain ends come, for example, from the condensation of polyamide precursors in the presence of a chain-limiting diamine. Particularly preferred PEBA copolymers in the context of the invention are copolymers comprising blocks: PA 11 and PEG; PA

II and PTMG; PA12 and PEG; PA 12 and PTMG; PA 6.10 and PEG; PA 6.10 and PTMG; PA 6 and PEG; PA 6 and PTMG.

The number-average molar mass of the polyamide blocks in the copolymer according to the invention is preferably from 400 to 20,000 g/mol, more preferably from 500 to 10,000 g/mol, even more preferably from 600 to 6,000 g/mol. In some embodiments, the number average molar mass of the polyamide blocks in the copolymer is from 400 to 500 g/mol, or from 500 to 1000 g/mol, or from 1000 to 1500 g/mol, or from 1500 at 2000 g/mol, or from 2000 to 2500 g/mol, or from 2500 to 3000 g/mol, or from 3000 to 3500 g/mol, or from 3500 to 4000 g/mol, or from 4000 to 5000 g/mol , or from 5000 to 6000 g/mol, or from 6000 to 7000 g/mol, or from 7000 to 8000 g/mol, or from 8000 to 9000 g/mol, or from 9000 to 10000 g/mol, or from 10000 to 11000 g/mol, or from 11000 to 12000 g/mol, or from 12000 to 13000 g/mol, or from 13000 to 14000 g/mol, or from 14000 to 15000 g/mol, or from 15000 to 16000 g/mol, or from 16,000 to 17,000 g/mol, or from 17,000 to 18,000 g/mol, or from 18,000 to 19,000 g/mol, or from 19,000 to 20,000 g/mol.

The number-average molar mass of the polyether blocks is preferably from 100 to 6000 g/mol, more preferably from 200 to 3000 g/mol. In embodiments, the number average molar mass of the flexible blocks is from 100 to 200 g/mol, or from 200 to 500 g/mol, or from 500 to 800 g/mol, or from 800 to 1000 g/mol , or from 1000 to 1500 g/mol, or from 1500 to 2000 g/mol, or from 2000 to 2500 g/mol, or from 2500 to 3000 g/mol, or from 3000 to 3500 g/mol, or from 3500 to 4000 g/mol, or from 4000 to 4500 g/mol, or from 4500 to 5000 g/mol, or from 5000 to 5500 g/mol, or from 5500 to 6000 g/mol.

The number-average molar mass is fixed by the content of chain limiter. It can be calculated according to the relationship:

Mn ⁼ H monomer X MW repeat pattern / H chain limiter + MW chain limiter

In this formula, nmonomer represents the number of moles of monomer, nchain-limiter represents the number of moles of excess chain limiter, MWrepeat unit represents the molar mass of the repeating unit, and MWüchain-limiter represents the molar mass of the limiter excess chain. The number-average molar mass of the polyamide blocks and of the polyether blocks can be measured before the copolymerization of the blocks by gel permeation chromatography (GPC).

Advantageously, the mass ratio of the polyamide blocks relative to the polyether blocks of the copolymer is from 0.1 to 20, preferably from 0.3 to 10, or from 0.3 to 5, or even more preferably from 0.3 to 1 . In particular, the mass ratio of the polyamide blocks relative to the polyether blocks of the copolymer 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 0.5 to 0.6, or 0.6 to 0.7, or 0.7 to 0.8, or 0.8 to 0.9, or 0 .9 to 1, or 1 to 1.5, or 1.5 to 2, or 2 to 2.5, or 2.5 to 3, or 3 to 3.5, or 3.5 to 4, or from 4 to 4.5, or from 4.5 to 5, or from 5 to 5.5, or 5.5 to 6, or 6 to 6.5, or 6.5 to 7, or 7 to 7.5, or 7.5 to 8, or 8 to 8.5, or 8.5 to 9, or 9 to 9.5, or 9.5 to 10, or 10 to 11, or 11 to 12, or 12 to 13, or 13 to 14, or 14 to 15, or 15 to 16, or 16 to 17, or 17 to 18, or 18 to 19, or 19 to 20.

Preferably, the PEBA copolymer of the invention has an instantaneous hardness less than or equal to 72 Shore D, preferably less than or equal to 55 Shore D, even more preferably less than or equal to 40 Shore D. The hardness measurements can be carried out according to ISO 868:2003.

The composition of the invention has a weight-average molar mass Mw greater than 80,000 g/mol. Preferably, the weight-average molar mass of the composition is from 80,000 to 300,000 g/mol, more preferably from 90,000 to 250,000 g/mol, more preferably still from 100,000 to 200,000 g/mol. The weight-average molar mass is expressed in PMMA equivalents (used as calibration standard) and can be measured by steric exclusion chromatography according to standard ISO 16014-1:2012, the copolymer being dissolved in hexafluoroisoproponol stabilized with 0 .05 M potassium trifluoroacetate for 24 h at room temperature at a concentration of 1 g/L to 2 g/L before being passed through the columns, for example at a flow rate of 1 mL/min, the molar mass being measured by a differential refractometer. Size exclusion chromatography can be performed using modified silica columns, for example on a set of two columns and a modified silica pre-column (such as Polymer Standards Service's PGF columns and pre-columns) comprising a 1000 Å column, with dimensions of 300 x 8 mm and a particle size of 7 μm, a 100 Å column, with dimensions of 300 x 8 mm and a particle size of 7 μm and a guard column with dimensions of 50 x 8 mm, for example at a temperature of 40°C.

In embodiments, the composition of the invention has a weight average molecular weight Mw ranging from 80,000 to 90,000 g/mol, or from 90,000 to 100,000 g/mol, or from 100,000 g/mol to 125,000 g/mol, or 125,000 to

150,000 g/mol, or 150,000 to 175,000 g/mol, or 175,000 to

200,000 g/mol, or 200,000 to 225,000 g/mol, or 225,000 to

250,000 g/mol, or 250,000 to 275,000 g/mol, or 275,000 to

300,000 g/mol. The composition of the invention may have a number-average molar mass Mn ranging from 30,000 to 100,000 g/mol, preferably from 35,000 to 80,000 g/mol, more preferably from 40,000 to 70,000 g/mol. The number-average molar mass is expressed in PMMA equivalents and can be measured according to standard ISO 16014-1 according to the method described above.

In embodiments, the composition has a number average molecular weight Mn ranging from 30,000 to 35,000 g/mol, or from 35,000 to 40,000 g/mol, or from 40,000 to 45,000 g/mol, or from 45,000 to 50,000 g/mol, or from 50,000 to 55,000 g/mol, or from 55,000 to 60,000 g/mol, or from 60,000 to 70,000 g/mol, or from 70,000 to 80,000 g/mol, or 80,000 to 90,000 g/mol, or 90,000 to 100,000 g/mol.

The composition may have an average molar mass in z Mz ranging from 200,000 to 1,000,000 g/mol, preferably between 300,000 and 800,000 g/mol. The molar mass in z is expressed in PMMA equivalents and can be measured according to standard ISO 16014-1 according to the method described above.

In embodiments, the composition has a z-average molecular weight Mz ranging from 200,000 to 250,000 g/mol, or from 250,000 to 300,000 g/mol, or from 300,000 to 350,000 g/mol, or from 350,000 to 400,000 g/mol, or from 400,000 to 450,000 g/mol, or from 450,000 to 500,000 g/mol, or from 500,000 to 550,000 g/mol, or from 550,000 to 600,000 g/mol, or 600,000 to 650,000 g/mol, or 650,000 to 700,000 g/mol, or 700,000 to 750,000 g/mol, or 750,000 to 800,000 g/mol, or 800,000 to 850,000 g/mol, or 850,000 to 900,000 g/mol, or 900,000 to 950,000 g/mol, or 950,000 to 1,000,000 g/mol,.

The polydispersity of the composition can be defined by the ratio of the weight-average molar mass Mw of the composition to the number-average molar mass Mn of the composition (ratio of molar masses Mw/Mn) and/or by the ratio of the z-average molar mass Mz of the composition relative to the weight-average molar mass Mw of the composition (ratio of molar masses Mz/Mw). The composition according to the invention has a molar mass ratio Mw/Mn greater than or equal to 2.4. In embodiments, the copolymer has a molar mass ratio Mw/Mn greater than or equal to 2.5, or greater than or equal to 2.6, or greater than or equal to 2.7, or greater than or equal to 2, 8, or greater than or equal to 2.9, or greater than or equal to 3.

The composition according to the invention may have a molar mass ratio Mz/Mw greater than or equal to 2, preferably greater than or equal to 2.5. In embodiments, the composition has a molar mass ratio Mz/Mw greater than or equal to 2.6, or greater than or equal to 2.7, or greater than or equal to 2.9, or greater than or equal to 3, 1, or greater than or equal to 3.3, or greater than or equal to 3.5.

Epoxy compounds

The epoxy compound of the invention has a number-average epoxy functionality (Efn) greater than 2, advantageously greater than or equal to 3, and possibly ranging up to 30. Preferably, the functionality (Efn) is between 3 and 20.

Within the meaning of the present invention, the average epoxide functionality corresponds to the average number of epoxide function per molecule of epoxide compound.

According to one embodiment, the epoxy equivalent weight (EEW) of the epoxy compound is from 80 to 700 g/mol.

According to one embodiment, the epoxy compound of the present invention is chosen from triglycidyl isocyanurate, trimethylolpropane triglycidyl ether, epoxy-novolac resins and epoxidized oils.

According to one embodiment, the epoxide compound of the present invention is chosen from random copolymers of (meth) acrylates with epoxide functions obtained by copolymerization of at least one (meth) acrylic monomer with epoxide function with at least one monomer chosen from an alkene monomer, a vinyl acetate monomer, a non-functional (meth)acrylic monomer, a styrenic monomer or mixtures of one or more of these species. Within the meaning of the present invention, the term (meth)acrylic monomer includes both acrylic and methacrylic monomers. Examples of epoxide-functional (meth)acrylic monomers include both acrylates and methacrylates. Examples of such epoxide-functional (meth)acrylic monomers include, but are not limited to, monomers containing 1,2-epoxide groups such as glycidyl acrylate and glycidyl methacrylate. Other suitable monomers may be glycidyl allyl ether, glycidyl ethacrylate and glycidyl itoconate.

Suitable alkene monomers, but not limited to, can be ethylene, propylene, butylene and mixtures of these species.

Suitable acrylate and methacrylate monomers, but not limited to, can be methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n -butyl, s-butyl acrylate, i-butyl acrylate, t-butyl acrylate, n-amyl acrylate, i-amyl acrylate, isobornyl acrylate, n-hexyl acrylate, acrylate 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-decyl acrylate, methylcyclohexyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacrylate n-butyl methacrylate, i-propyl methacrylate, i-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, i-amyl methacrylate, s-butyl methacrylate, i-amyl methacrylate - butyl methacrylate, 2-ethylbutyl methacrylate, methylcyclohexyl methacrylate, cinnamyl methacrylate, crotyl methacrylate, cyclohexyl methacrylate, methacrylate cyclopentyl, 2-ethoxyethyl methacrylate and isobornyl methacrylate.

Styrenic monomers include, but are not limited to, styrene, alpha-methylstyrene, vinyltoluene, p-methylstyrene, t-butylstyrene, o-chlorostyrene, vinylpyridine, and mixtures of these species. In certain embodiments, the styrenic monomers for use in the present invention are styrene and alpha-methylstyrene.

According to one embodiment, the epoxy compound of the present invention is chosen from random copolymers of styrene-(meth)acrylate with epoxide functions obtained from monomers of at least one epoxy-functional (meth)acrylic monomer and at least one non-functional styrene and/or (meth)acrylic monomer.

In one embodiment, the epoxy compound contains between 25 and 50% by weight of at least one epoxide-functional (meth)acrylic monomer and 75 to 50% of at least one styrenic and/or non-epoxide functional (meth)acrylic monomer. functional. More preferentially, the epoxide compound contains between 25% and 50% by weight of at least one (meth)acrylic monomer with epoxide function, between 15% and 30% by weight of at least one styrenic monomer, and between 20% and 60% by weight of at least one non-functional acrylate and/or methacrylate monomer.

In one embodiment, the epoxy compound contains between 50 and 80% by weight, based on the total weight of the monomers, of at least one epoxy-functional (meth)acrylic monomer and 20 to 50% of at least one styrenic monomer. and/or non-functional (meth)acrylic. More preferentially, the epoxide compound contains between 50% and 80% by weight of at least one (meth)acrylic monomer with epoxide function and between 15% and 45% by weight of at least one styrenic monomer and between 0% and 5 % by weight of at least one non-functional acrylate and/or methacrylate monomer.

In one embodiment, the epoxy compound contains between 5 and 25% by weight of at least one epoxide-functional (meth)acrylic monomer and 75 to 95% of at least one styrenic and/or (meth)acrylic monomer not functional. More preferentially, the epoxide compound contains between 5% and 25% by weight of at least one (meth)acrylic monomer with epoxide function, between 50% and 95% by weight of at least one styrenic monomer, and between 0% and 25% by weight of at least one non-functional acrylate and/or methacrylate monomer.

According to embodiments, the epoxide compound is chosen from styrene-(meth)acrylate copolymers with epoxide functions obtained from monomers of at least one (meth)acrylic monomer with epoxide function and at least one styrenic monomer and / or non-functional (meth) acrylic, preferably chosen from styrene-(meth) acrylate copolymers with epoxide functions obtained from monomers of at at least one epoxide-functional (meth)acrylic monomer and at least one styrenic monomer.

According to one embodiment, the epoxy compound is obtained from at least one (meth)acrylic monomer with epoxy function and from at least one styrenic monomer. According to one embodiment, the epoxy compound contains from 50% to 80% by weight, relative to the total weight of the monomers, of at least one (meth)acrylic monomer with epoxide function and between 20% and 50% by weight of at least one styrenic monomer.

According to a preferred embodiment, the epoxy compound is a random copolymer of styrene and glycidyl methacrylate.

The weight-average molar mass (Mw) of the styrene-(meth)acrylate copolymer with epoxide functions is preferably less than 25,000 g/mol, more preferably less than 20,000 g/mol; and is generally in the range of 3,000 to 15,000 g/mol, preferably 5,000 to 10,000 g/mol.

Process for preparing the composition

The process of the invention can be a batch process or preferably a continuous process.

Typically, the process includes a melt-mixing step. The conditions applied at this stage are chosen to allow intimate mixing of the compounds in the molten state.

According to one embodiment, a temperature higher by at least 5° C., preferably higher by at least 10° C., is applied to the mixing step with respect to the melting point of the composition. This temperature must generally remain below 300° C., so as to avoid thermal degradation of the copolymer of the invention.

In the context of the present invention, one or more PEBA copolymers can be introduced. When a single PEBA copolymer is used, the temperature applied is at least 10°C higher, preferably at least 30°C higher than the melting temperature of the copolymer. When several copolymers are used, the temperature applied is higher by at least 10° C., preferably higher by at least 30° C., with respect to the highest melting temperature of the copolymers.

According to one embodiment, the temperature applied to the melt-mixing step is greater than 200°C and less than 300°C.

When one or more component(s) (C) are introduced during the mixing step, a temperature higher by at least 5°C, preferably higher by at least 10°C, is applied with respect to the temperature of highest fusion of PEBA copolymer(s) and component(s) (C).

According to one embodiment, one or more additives are added during the mixing step of the preparation process.

Typically, the additives are chosen from stabilizers (for example, antioxidants, in particular phenolic, or phosphorus-based or sulfur-based, light stabilizers of the hindered amine or HALS type, UV absorbers and/or flame), fillers, in particular mineral fillers, such as talc, reinforcing fibers, in particular of glass or carbon, nucleating agents (for example, CaCO3, ZnO, SiO2, or combinations of two or more these), mold release agents, colorants, pigments (eg TiO2 or other compatible colored pigments), optical brighteners, photochromic additives, catalysts (eg zinc acetate, titanium acetate, magnesium acetate, calcium), plasticizers and/or lubricants or mixtures thereof.

According to one embodiment, it is possible to add from 0 to 10%, preferably 0.1 to 5% of additives relative to the total weight of the PEBA copolymer at the mixing stage of the process.

The method includes a step of extruding the mixture in the molten state. The process may comprise a step of recovering the product obtained by cooling using a cooling liquid containing water and/or a step of separating the cooling liquid and the product cooled and/or a step of shaping the cooled product in the form of rods or ribbons, or directly in the form of granules.

As an installation for carrying out the method of the invention, any device for mixing, kneading or extruding plastic materials in the molten state known to those skilled in the art can be used. Examples include internal mixers, roller mixers, single-screw, contra or co-rotating twin-screw extruders, continuous co-kneaders, or stirred reactors. The mixing device can be one of the tools mentioned above or their combination, such as for example a co-kneader associated with a single-screw extruder.

Preferably, all or part of the process according to the invention is carried out in a co-rotating twin-screw extruder.

Advantageously, the method is carried out by reactive extrusion, typically in an extruder.

Mousse

The foam as described above can be prepared by a manufacturing process, comprising:

- a step of supplying a mixture comprising a composition as defined above, optionally with one or more additives, and a blowing agent; and

- a step of foaming the mixture.

According to one embodiment, the mixture may comprise another component chosen from polyamides, functional polyolefins, copolyetheresters, thermoplastic polyurethanes (TPU), copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylate , and copolymers of ethylene and alkyl (meth) acrylate. These components can be added preferably in a content of 0 to 50% by weight, preferably 5 to 30% by weight, relative to the total weight of the mixture.

The blowing agent can be a chemical or physical agent, or even a mixture of these. Preferably, it is a physical agent, such as by example dinitrogen or carbon dioxide, or water, or a hydrocarbon, chlorofluorocarbon, hydrochlorocarbon, hydrofluorocarbon or hydrochlorofluorocarbon (saturated or unsaturated). For example butane or pentane can be used.

A physical blowing agent can be mixed with the composition in liquid or supercritical form, then converted into the gas phase during the foaming step. The physical blowing agent can remain present in the pores of the foam, especially if it is a closed-pore foam, and/or dissipate.

It can also be a chemical agent such as for example azodicarbonamide or mixtures based on citric acid and sodium hydrogen carbonate (NaHCOs) (such as products from the Hydrocerol® range from Clariant).

The foam thus formed consists essentially, or even consists, of the composition described above (or the mixture, if a mixture of polymers is used) and optionally one or more additives being dispersed in the matrix.

In the case where a chemical blowing agent is used, the foam may comprise in addition to the composition described above (or the mixture, if a mixture of polymers is used), the decomposition products of the chemical blowing agent chemical expansion, these being dispersed in the matrix.

Foaming technologies can be “batch” foaming, injection foaming, extrusion foaming, such as single-screw or twin-screw extrusion foaming, autoclave foaming and foaming with microwaves.

According to one embodiment, the step of supplying the mixture occurs in the molten state.

Advantageously, the method according to the invention comprises a step of injecting said mixture into a mold and a step of foaming said mixture. The foaming is produced either during the injection into the mold of a volume of polymer lower than that of the mold, or by the opening of the mold. These two techniques, each or in combination, make it possible to directly produce three-dimensional foamed objects with complex geometries. These are also techniques that are relatively simple to implement, in particular compared to certain processes for melting foamed particles as described in the prior art: in fact, filling the mold with foamed polymer granules then melting particles to ensure the mechanical strength of parts without destroying the structure of the foam are complex operations.

Other injection foaming techniques that can be used in the context of the present invention are in particular injection foaming with a breathable mold, with application of a gas counter-pressure, under dosage, or with a mold equipped with a Variotherm® system.

According to one embodiment, the foaming process according to the invention comprises a step of supplying the mixture in the molten state, and a step of extruding said mixture, inducing the foaming of said mixture directly at the outlet of the extrusion die.

According to yet another embodiment, the foaming process comprises a step of impregnating a gas, typically an inert gas, into an object resulting from a composition as described above, at a pressure above atmospheric pressure to force the introduction of the gas into the object and a pressure reduction step allowing the gas to dissipate to produce the foam. In this case, the object can typically be a particle, a part injected or extruded from the composition.

Mention may be made, as additives, of pigments (TiO2 and other compatible colored pigments), adhesion promoters (to improve the adhesion of expanded foam to other materials), fillers (for example, calcium carbonate, sulphate of barium and/or silicon oxide), nucleating agents (in pure form or in concentrated form, e.g., CaCO3, ZnO, SiO2, or combinations of two or more of these), rubbers (to improve the rubbery elasticity, such as natural rubber, SBR, polybutadiene and/or ethylene propylene terpolymer), stabilizers e.g. antioxidants, UV absorbers and/or flame retardants and additives to improve the processing aids, for example, stearic acid. The additives can preferably be added in a content of 0 to 10% by weight relative to the composition.

The foam according to the invention preferably has a density less than or equal to 800 kg/m ³ , more preferably less than or equal to 600 kg/m ³ , even more preferably less than or equal to 400 kg/m ³ , and in a particularly preferably less than or equal to 300 kg/m ³ . It can for example have a density of 25 to 800 kg/m ³ , and more particularly preferably of 50 to 600 kg/m ³ . Density control can be achieved by adapting the parameters of the manufacturing process. Preferably, this foam has a rebound resilience, according to standard ISO 8307:2007, greater than or equal to 50%, preferably greater than or equal to 55%.

Preferably, this foam has a residual deformation in compression after 30 minutes of relaxation, less than or equal to 65%, and more particularly preferably less than or equal to 50%, or less than or equal to 45%, or 40%, or 35%.

Preferably, this foam also has excellent fatigue resistance and damping properties.

Another advantage of the foam of the present invention provides better adhesion to other components to facilitate complex assembly. This is particularly interesting in the production of multilayer structures by overmolding processes, for example, in the context of the preparation of a shoe sole which is often in the form of multilayers.

The foam according to the invention can be used to manufacture sports equipment, such as soles of sports shoes, ski boots, intermediate soles, insoles, or even functional components of soles, in the form of inserts in different parts of the sole (heel or arch for example), or even components of shoe uppers in the form of reinforcements or inserts in the structure of the shoe upper, in the form of protections. It can also be used to manufacture balls, sports gloves (for example football gloves), golf ball components, rackets, protective elements (vests, interior elements of helmets, hulls, etc.). ).

The foam according to the invention has interesting anti-shock, anti-vibration and anti-noise properties, combined with haptic properties suitable for capital goods. It can therefore also be used for the manufacture of rail shoes, or various parts in the automotive industry, in transport, in electrical and electronic equipment, in construction or in the manufacturing industry.

According to one embodiment, the foam articles according to the invention can be recycled, for example by melting them in an extruder equipped with a degassing outlet (optionally after having cut them into pieces).

Examples

The following examples illustrate the invention without limiting it.

Used materials :

PEBA 1: copolymer with PA11 blocks and PTMG blocks whose number-average molecular masses (Mn) are each 1000 g/mol. The end of the acid chain content of the copolymer is 56 pmol/g.

PEBA 2: copolymer with PA12 blocks and PTMG blocks whose number-average molecular masses (Mn) are respectively 600 and 2000 g/mol. The end of the acid chain content of the copolymer is 49 pmol/g.

Epoxide compound X: random copolymer of styrene and glycidyl methacrylate. The molar mass by weight Mw of the copolymer is 7100 g/mol. The epoxy equivalent weight (EEW) of the epoxy compound is 485 g/mol.

Epoxide compound Y: random copolymer of styrene and glycidyl methacrylate. The molar mass by weight Mw of the copolymer is 50,000 g/mol. The epoxy equivalent weight (EEW) of the epoxy compound is 917 g/mol.

Epoxide compound Z: Lotader AX8900, random terpolymer of ethylene, glycidyl methacrylate and maleic anhydride (68/8/24 in mass proportion). The epoxy equivalent weight (EEW) of the epoxy compound is 1775 g/mol.

Preparation process:

The PEBA copolymer and the epoxy compound are mixed in the molten state in a reactive extrusion process in a co-rotating twin-screw extruder. The equipment used is a Coperion ZSK 26 MC extruder with a diameter of 26mm and a length of 40D. The materials are fed at a rate of 7.5 kg/h into the extruder, the screw speed of which is set at 300 rpm and the barrel temperature at 240°C. The product leaving the extruder is granulated into a section under water.

Measurement methods:

- Differential calorimetric analysis (DSC): In the context of the present invention, the melting point is measured by DSC with a heating rate of 20° C./min according to ISO 11357-1.

- Rheology: the complex viscosity (q*) of the product is determined by oscillatory rheometry according to ISO 6721-10 with a plane-plane geometry with a diameter of 25 mm and an air gap of 1 mm. The measurement is carried out in the linear range at 180° C. under nitrogen sweeping. Over the range of angular frequencies oo between 0.135 and 1.35 rd/s, the complex viscosity (q*) of the composition follows a power law as defined by the following equation: q* = K (œ) ⁿ - ¹

The measurements taken make it possible to calculate the value of the coefficient n over this frequency range.

- Solubility test: A solution test is carried out by placing 0.5% of product in a solution of m-cresol at 100°C for 2 hours with stirring.

- Steric exclusion chromatography (or gel permeation chromatography): used to measure the molar masses in number Mn, in weight Mw and in z Mz according to ISO 16014-1:2012. The product is dissolved in hexafluoroisoproponol stabilized with 0.05 M potassium trifluoroacetate for 24 hours at room temperature at a concentration of 1 g/L. The solution obtained is then filtered on a PTFE membrane with a porosity of 0.2 μm, then injected at a flow rate of 1 mL/min, into a liquid chromatography system equipped with a set of PFG columns from Polymer Standards Service consisting of a pre- column of dimensions 50 x 8 mm, of a column of 1000 Å, of dimensions 300 x 8 mm and of particle size 7 µm, and of a column of 100 Å, of dimensions 300 x 8 mm and of particle size 7 µm , The molar masses are measured by the refractive index and are expressed in PMMA equivalents (used as a calibration standard).

- Abrasion resistance: The product is injected at 220°C in the form of 100x100x2 mm plates. The abrasion resistance of these is measured according to ISO 9352:2012, and is expressed by the loss of mass associated with 1000 rotations of a 1 kg H18 grinding wheel.

- Resistance to compression deformation: The product is injected at 220°C in the form of cylinders with a diameter of 29.3 mm and a height of 12.7 mm. A compression deformation of 25% is applied to the surface of the cylinders for 70 hours at 23°C according to ISO 815-1. After 30 minutes then 24 hours of relaxation, the residual deformation of the sample is measured.

- Overmoulding: The overmoulding capacity of the product is evaluated in association with the TPU Elastollan 1195 A 10,000. A TPU insert measuring 170x25x2 mm is first injected at 215°C. 24 hours later, this cold insert is placed in an overmoulding mould. A new strip of 170x25x2 mm of the product is injected at 240°C on the surface of the insert. 7 days after this shaping, the measurement of interfacial adhesion is carried out by peeling at a free angle on a dynamometer according to ISO 8510-2. The ends of the 2 strips of TPU and of the composition are fixed to the jaws of the dynamometer which applies a traction of 50 mm/min. The force at equilibrium during the propagation of the decohesion is measured and characterizes the adhesion between the 2 overmolded polymers.

Results:

The compositions of the examples are given in mass percentage: Compositions A to F comprise PEBA 1 . Compositions G to K include PEBA 2.

[Table 1]

Differential scanning calorimetry:

[Table 2]

Oscillatory rheometry measurement:

The melting point of the various compositions is measured (Table 2). The complex viscosity is measured at Tf +30°C (analysis T°).

[Table 3] [Table 4]

Composition A (100% linear PEBA 1 copolymer, Counterexample) exhibits a Newtonian plateau at low frequencies (or=0.135-1.35) which corresponds to a value of n=0.98. Inventive compositions B, C and D have n values of 0.78, 0.70 and 0.65. Composition E has an n value of 0.51.

Composition F has a Newtonian plateau at low frequencies (oo = 0.135-1.35) which corresponds to a value of n = 0.96.

Composition G (100% linear PEBA 2 copolymer, Counterexample) exhibits a Newtonian plateau at low frequencies (or=0.135-1.35) which corresponds to a value of n=0.99. The compositions of the invention H have an n value of 0.87.

Solubilization test [Table 5]

It was observed that compositions B to D on the one hand, F to K on the other hand, remain soluble in m-cresol, which illustrates their thermoplastic and recyclable behavior.

Conversely, composition E is not soluble and this confirms the crosslinking of the latter.

Chromatography: Masses Mn, Mw and Mz: [Table 6]

Compositions B, C and D according to the invention have higher molar masses by weight (Mw) and z (Mz) compared to composition A. This illustrates a broader distribution of the molecular masses of compositions B, C and D which results in higher values of the dispersity indices Mw/Mn and Mz/Mw.

Abrasion resistance:

[Table 7]

Compositions B, C and D according to the invention have better abrasion resistance compared to Comparative Example A and Comparative Example F.

Composition H according to the invention has better resistance to abrasion compared to comparative examples G, I to K.

Compressive strength :

[Table 8] Compositions B, C and D according to the invention have a lower compression set than composition A and comparative example F. They therefore have better compressive strength. Composition H according to the invention has better resistance to abrasion compared to comparative examples G, I to K, and therefore has better resistance to compression.

Overmolding: [Table 9]

It was observed that composition D exhibits better adhesion when overmolded onto a TPU support. Thus, the compositions of the invention have improved properties in terms of mechanical strength, in particular resistance to abrasion and resistance to compression, and better adhesion during overmolding.

Claims

34 CLAIMS

1. Composition comprising a copolymer with polyamide blocks and polyether blocks (PEBA copolymer) comprising an end of the carboxylic acid chain of the polyamide block blocked by an epoxide function carried by an epoxide compound whose number-average functionality (Efn) is greater than 2 , preferably greater than or equal to 3 and whose epoxide equivalent weight (EEW) is from 80 to 700 g/mol, said composition having a complex viscosity (q*) which follows a power law as defined by following equation: q* = K (œ) ⁿ - ¹ (I) in which:

- K is a constant;

- oo is the angular frequency applied in oscillatory rheometry in the linear domain at a temperature 30°C above the melting point of the composition according to

ISO 6721-10; and

2. Composition according to claim 1, having a weight-average molar mass (Mw) ranging from 80,000 to 300,000 g/mol, preferably from 90,000 to 250,000 g/mol, more preferably from 100,000 to 200,000 g /mol.

3. Composition according to one of the preceding claims, in which the ratio of the weight-average molar mass (Mw) to the number-average molar mass (Mn) is greater than or equal to 2.4, and/or the ratio of the z-average molar mass (Mz) over the weight-average molar mass Mw is greater than or equal to 2, preferably greater than or equal to 2.5.

4. Composition according to one of the preceding claims, in which the polyamide block PA is chosen from blocks of PA 6, PA 11, PA 12, PA 5.4, PA 5.9, PA 5.10, PA 5.12, from PA 5.13, from PA 5.14, from PA 5.16, from PA 5.18, from 35

PA 5.36, PA 6.4, PA 6.9, PA 6.10, PA 6.12, PA 6.13, PA 6.14, PA 6.16, PA 6.18, PA 6.36, PA 10.4, PA 10.9, PA 10.10 , PA 10.12, PA 10.13, PA 10.14, PA 10.16, PA 10.18, PA 10.36, PA 10.T, PA 12.4, PA 12.9, PA 12.10, PA 12.12, PA 12.13 , PA 12.14, PA 12.16, PA 12.18, PA 12.36, PA 12.T, mixtures thereof, or copolyamides thereof, and/or the polyether block is chosen from PEG, PPG, PO3G, PTMG , mixtures thereof or copolymers thereof. Composition according to one of the preceding claims, in which the PEBA copolymer results from the polycondensation of polyamide blocks with dicarboxylic chain ends with polyetherdiols. Composition according to one of the preceding claims, in which the epoxide compound is chosen from random copolymers of (meth)acrylates with epoxide functions obtained by copolymerization of at least one (meth)acrylic monomer with epoxide function with at least one monomer chosen from an alkene monomer, a vinyl acetate monomer, a non-functional (meth)acrylic monomer, a styrenic monomer or mixtures of one or more of these species. Composition according to one of the preceding claims, further comprising at least one component (C) chosen from polyamides, functional polyolefins, copolyetheresters, thermoplastic polyurethanes (TPU), copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylate, and copolymers of ethylene and alkyl (meth)acrylate, and/or one or more additives (D) chosen from nucleating agents, fillers, in particular mineral fillers, such as talc , reinforcing fibers, in particular of glass or carbon, dyes, UV absorbers, antioxidants, in particular phenolic, or phosphorus-based or sulfur-based, light stabilizers of the hindered amine or HALS type, and mixtures thereof . Process for the manufacture of a composition according to one of Claims 1 to 7, comprising a step of mixing, typically in the molten state, a PEBA copolymer, a epoxy compound whose epoxy equivalent weight (EEW) is 80 to 700 g/mol, optionally of one or more component(s) (C) and/or of one or more additives (D), so that at least one end of the carboxylic acid chain of the PEBA copolymer reacts with an epoxide function of the epoxide compound, said composition having a complex viscosity (q*) which follows a power law as defined by the following equation: q* = K (œ) ⁿ - ¹ (I) in which:

- K is a constant;

ISO 6721-10; and

- the value of n is between 0.55 and 0.95, preferably between 0.60 and 0.90, even more preferably between 0.65 and 0.85, or even between 0.70 and 0.85, on the range of angular frequencies oo comprised between 0.135 and 1.35 rad/s. A method according to claim 8, wherein the PEBA copolymer has a carboxylic acid end-chain content of 10 to 200 pmol/g. Process according to Claim 8 or 9, in which the molar ratio of the content at the end of the carboxylic acid chain of the PEBA copolymer to the content of epoxide function of the epoxy compound is typically between 2 and 20, preferably between 3 and 10. Process according to one of claims 8 to 10, wherein the process is carried out by reactive extrusion, typically in an extruder. Composition capable of being obtained according to the process of one of Claims 8 to 11. Foam of a composition according to one of Claims 1 to 7 or 12. Article, such as a fibre, a fabric, a film, a sheet, a sheet of foam, a particle of foam, a rod, a tube, an injected and/or extruded part, consisting of or comprising at at least one element consisting of a composition as defined in one of Claims 1 to 7 or 12 or of a foam according to Claim 13. Article according to Claim 14, constituting at least part of one of the following articles: sporting article, shoe part, sports shoe part, shoe sole, in particular crampon, ski part, in particular ski boot or ski shell, sports utensil such as ice skates, ski bindings, snowshoes , sports bats, boards, horseshoes, protective gaiters, flippers, golf balls, articles for leisure, DIY, tools or road equipment, equipment or protective articles, such as visors for helmets, glasses, branches of eyeglasses, automobile part, car part such as dashboard, airbag, headlight guard, rear-view mirror, small part of off-road cars, tank, especially of scooter, moped, motorcycles, industrial part, industrial additive, electrical part, electronics electronics, data processing, tablet, telephone, computer, safety accessory, sign, light strip, signage and advertising panel, display, engraving, furnishings, store fittings, decoration, contact ball, medical device, dental prosthesis, implant, article of ophthalmology, membrane for hemodialyzer, optical fibres, work of art, sculpture, camera lenses, disposable camera lenses, printing support, in particular direct printing support with UV inks, for photo board, glass , panoramic roof, transmission belt, antistatic additive, waterproof-breathable product or film, support for active molecules, coloring agent, welding agent, decorative element, and/or additive for polyamide, sole for rail, part for stroller, wheel , handle, seat element, part of a child's car seat, part of construction, part of audio equipment, acoustic and/or thermal insulation, part intended to absorb shocks and/or vibrations, such as those generated by a means of transport, wheels, rolling smoothly such as a tire, textile, woven or non-woven, packaging, peristaltic belt, conveyor belt strip, skin and/or synthetic leather.