FR3077576A1 - USE OF A MASTER MIXTURE COMPRISING A FLUORINE COMPOUND FOR DECREASING THE CORE TEARS - Google Patents

Abstract

The present invention relates to the use of a masterbatch comprising at least one fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C, as determined according to ISO 11357-3: 2013, with a composition comprising at least one polyamide P1 and at least one polyolefin, for reducing die tears during the extrusion of said composition and said masterbatch in the form of a monolayer structure, in particular in the form of a tube or film, while maintaining a good calibration and good mechanical and thermal properties of said monolayer structure.

Description

USE OF A MASTER MIXTURE COMPRISING A FLUORINATED COMPOUND TO REDUCE THE TEARS OF THE INDUSTRY

The present invention relates to the use of a masterbatch comprising at least one fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C with a composition comprising at least one semi-crystalline polyamide P1 and at least one polyolefin, for reducing the tears in the die during the extrusion of said composition and said masterbatch.

The present invention also relates to the use of said masterbatch with said compositions to constitute a monolayer structure or at least one layer of a multilayer structure.

It also relates to a process for preparing a monolayer structure or at least one layer of a multilayer structure, in particular in the form of a tube or film.

In the automotive industry, for example, compositions based on one or more polyamides, in particular semi-aromatic ones, are increasingly used, because of the remarkable thermomechanical properties which they confer on parts produced from such compositions.

To simultaneously improve the preparation of these compositions as well as their transformation, in particular by implementing an extrusion, co-extrusion or extrusion blow molding step, international application WO 2011/015790 describes compositions comprising 45% to 95% by weight of a semi-aromatic polyamide and from 5% to 55% by weight of at least one crosslinked polyolefin, the weight proportions being given relative to the total weight of the composition.

The crosslinked polyolefin, which occurs as a phase dispersed in the matrix formed by the semi-aromatic polyamide, comes from the reaction:

- a product (A) comprising an unsaturated epoxide,

- a product (B) comprising an unsaturated carboxylic acid anhydride or a polycarboxylic acid, and optionally

- a product (C) comprising an unsaturated carboxylic acid or an alphaomega-aminocarboxylic acid.

If such compositions can effectively be transformed by extrusion, co-extrusion or extrusion blow molding, it can be observed that the interior and exterior surfaces of the tubes extruded from these compositions do not always have a regular appearance and may have defects. of surface giving an aspect which is not smooth but mat, even rough. An irregular appearance of these external surfaces of the extruded tubes can thus have damaging consequences on the mechanical properties of these tubes.

We can also observe the formation of deposits at the level of the screw and / or of the extrusion die, also called die tears, during this transformation step. The formation of these die tears is not without impact on the production of the tubes and on the maintenance of the extrusion equipment.

To solve this problem, international application WO 2013/054025 describes compositions comprising at least one semi-aromatic polyamide and at least one crosslinked polyolefin, the crosslinked polyolefin being obtained from:

- at least one product (A) comprising an unsaturated epoxide and

- at least one product (B) comprising an unsaturated carboxylic acid anhydride.

However, tubes, in particular small diameters, are always difficult to extrude, in particular with semi-aromatic polyamides, due to the formation of die tears which disrupt production.

Thus, there is a real need to find new compositions allowing not only a transformation without the formation of tears in the die, but also ensuring the production of extruded parts with smooth external surfaces, such parts obviously retaining all the advantages in terms mechanical properties such as thermal resistance, VW shock at -40 ° C, determined according to TL 52435, pressure stability and calibration of the parts formed from compositions based on semi-aromatic polyamide (s) ) of the prior art.

Thus the present invention relates to the use of a masterbatch comprising at least one fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C, as determined according to ISO 11357-3: 2013 , with a composition comprising at least one semi-crystalline polyamide P1 and at least one polyolefin, for reducing the tears in the die during the extrusion of said composition and of said masterbatch in the form of a monolayer structure, in particular in the form of tube or film, while retaining good calibration and good mechanical and thermal properties of said monolayer structure.

A semi-crystalline polyamide, within the meaning of the invention, denotes a polyamide which has a melting temperature (Tf) in DSC according to ISO standard 11357-3: 2013, and an enthalpy of crystallization during the cooling step to a speed of 20K / min in

DSC measured according to ISO 11357-3 of 2013 greater than 30 J / g, preferably more than 40 J / g.

The expression “masterbatch” designates a concentrate of different compounds subsequently used in small proportion as opposed to a compound which is subsequently used at 100%.

The term "fluorinated compound" refers to organic compounds whose molecule contains one or more fluorine atoms. The fluorinated compounds according to the invention not only contain one or more fluorine atoms but also have a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C, as determined according to ISO 11357-3: 2013.

Advantageously, the fluorinated compounds with Tf greater than or equal to 240 ° C., in particular greater than or equal to 280 ° C. are chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorine (FEP), l ' ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE).

The inventors have unexpectedly found that the use of a masterbatch comprising a fluorinated compound with a composition comprising at least one semi-crystalline polyamide P1 and a polyolefin makes it possible to reduce tears in the dies while retaining good mechanical properties such that the VW shock at -40 ° C, determined according to TL 52435, good thermal resistance, pressure stability leading to good calibration of the parts formed with respect to a composition in which the addition of said fluorinated compound is done directly in said composition or with respect to a composition without fluorinated compound or also with respect to a composition comprising a fluorinated compound but with a Tf of less than 280 ° C. and thus allowing easier implementation during extrusion in the form of a structure monolayer, in particular in the form of a tube or film.

The addition of said fluorinated compound of Tf greater than or equal to 240 ° C., in particular greater than or equal to 280 ° C. in the form of a masterbatch is therefore essential both for the reduction of tears in the dies and for the conservation of the mechanical properties, thermal resistance and pressure stability leading to good calibration.

In one embodiment, said fluorinated compound is in proportion ranging from 0.01% by weight to 0.3% by weight relative to the total weight of said composition and of the masterbatch.

This is therefore the final proportion of fluorinated compound in the mixture constituted by said composition and said masterbatch.

Above 0.3% by weight, the mechanical properties and the thermal resistance are deteriorated, in particular the VW shock at -40 ° C but also due to the pressure drop caused by an excessive addition of fluorinated compound, the calibration, especially of tubular structures, is difficult.

Below this, the proportion of tears in the sector is too high.

Another advantage of the use of fluorinated compound in the form of masterbatch is the reduction in the rate of fluorinated compound present relative to the total weight of said composition compared to a composition without masterbatch but comprising a fluorinated compound of Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C.

With regard to the polyamide P1 of the composition

The semi-crystalline polyamide P1 of the composition can be an aliphatic polyamide or a semi-aromatic polyamide.

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

Semi-aromatic polyamide

The composition according to the invention comprises at least one semiaromatic polyamide.

This semi-aromatic polyamide comprises at least a first semi-aromatic repeating unit which is obtained from the polycondensation of a diamine and an aromatic dicarboxylic acid.

The diamine advantageously comprises between 4 and 36 carbon atoms.

The diamine can be chosen from aliphatic diamines, cycloaliphatic diamines and alkylaromatic diamines. These diamines can be linear. They can also be branched and comprise at least one alkyl branch on the main chain, this alkyl branch can itself be linear or branched.

When the diamine is aliphatic and linear, it corresponds to the formula H2N- (CH2); r NH2. It can thus be chosen from butanediamine (x = 4), pentanediamine (x = 5), hexanediamine also called hexamethylene diamine (x = 6), heptanediamine (x = 7), octanediamine (x = 8), nonanediamine (x = 9), decanediamine (x = 10), undecanediamine (x = 11), dodecanediamine (x = 12), tridecanediamine (x = 13), tetradecanediamine (x = 14), hexadecane diamine (x = 16), octadecanediamine (x = 18), octadecenediamine (x = 18), eicosanediamine (x = 20), docosanediamine (x = 22) and diamines obtained from fatty acids. Such diamines all have the advantage of being able to be bioresourced and to contain organic carbon derived from biomass, which can be determined according to standard ASTM D6866.

When the diamine is cycloaliphatic, it can be chosen from bis (3,5dialkyl-4-aminocyclohexyl) methane, bis (3,5-dialkyl-4-aminocyclohexyl) -ethane, bis (3,5dialkyl-4-aminocyclohexyl ) propane, bis (3,5-dialkyl-4-amino-cyclohexyl) butane, bis- (3methyl-4-aminocyclohexyl) -methane (BMACM or MACM), p-bis (aminocyclohexyl) methane (PACM) and isopropylidenedi (cyclohexylamine) (PACP). The cycloaliphatic diamine can also comprise the following carbon skeletons: norbornyl methane, cyclohexylmethane, dicyclohexylpropane, di (methylcyclohexyl), di (methylcyclohexyl) propane. A non-exhaustive list of these cycloaliphatic diamines is given in the publication Cycloaliphatic Amines (Encyclopaedia of Chemical Technology, Kirk-Othmer, 4th Edition (1992), pp. 386-405).

When the diamine is alkylaromatic, it can be chosen from 1,3-xylylene diamine and 1,4-xylylene diamine.

Advantageously, the diamine is an aliphatic diamine.

Preferably, the diamine is a linear aliphatic diamine.

The aromatic dicarboxylic acid can be chosen from terephthalic acid (noted T), isophthalic acid (noted I), phthalic acid and naphthalenic acids. The aromatic dicarboxylic acids which have just been mentioned can also comprise one or more alkyl branches, these alkyl branches can themselves be linear or branched. Mention may thus be made of 2-methyl-terephthalic acid.

Advantageously, the semi-aromatic polyamide has a melting temperature above 230 ° C, advantageously between 230 ° C and 300 ° C, and more particularly between 260 ° C and 280 ° C.

More particularly preferably, the aromatic dicarboxylic acid is terephthalic acid (T).

According to a particular version of the invention, the semi-aromatic polyamide may comprise more than 50% by mol of first repeating unit (s), advantageously more than 60% by mol.

One can in particular consider the use of a semi-aromatic polyamide consisting of 100% by mol of one or more first repeating units.

In particular, according to a first aspect of the invention, this semiaromatic polyamide can be a homopolymer and consist only of first repeating units resulting from the polycondensation reaction of a diamine and an aromatic dicarboxylic acid.

Thus, the semi-aromatic polyamide can be chosen from homopolyamides 11.T, 12.T, 14.T, 18.T, 6.I, 9.I, 10.1, 11.1, 12.1, 14.1 and 18.1.

According to a second aspect of the invention, this semi-aromatic polyamide can be a copolymer consisting of first repeating units resulting from the polycondensation reaction of a diamine and two aromatic dicarboxylic acids or from the polycondensation reaction of two diamines and d 'an aromatic dicarboxylic acid.

Thus, in the first case, the semi-aromatic polyamide can be chosen from copolyamides 6.T / 6.I, 9.T / 9.I, 10.T / 10.I, 11.T / 11.1 and 12. T / 12.I. In the second case, the semi-aromatic polyamide can be chosen from copolyamides 6.T / 11.T, 6.T / 12.T, 9.1711.T, 9.T / 12.T, 10.1711.T, 10. T / 12.T and 11 .T / 12.T. A similar list can be established, replacing terephthalic acid (T) with isophthalic acid (I).

According to a third aspect of the invention, this semi-aromatic polyamide may be a copolymer comprising first repeating units resulting from the polycondensation reaction of at least two diamines and at least two aromatic dicarboxylic acids.

In addition to this at least one first semi-aromatic repeating unit which has just been detailed and which is obtained from the polycondensation of a diamine and an aromatic dicarboxylic acid, the semi-aromatic polyamide of the composition according to l The invention may also include at least one second repeating pattern, this second repeating pattern being necessarily distinct from the first repeating pattern (s).

This second repeating unit can be chosen from the group consisting of a unit obtained from an aminocarboxylic acid, a unit obtained from a lactam and a unit corresponding to the formula (diamine in Ca). (Cb diacid), with a representing the number of carbon atoms in the diamine and b representing the number of carbon atoms in the diacid.

Advantageously, a and b are each between 4 and 36.

When this second repeating unit is obtained from an aminocarboxylic acid, this aminocarboxylic acid can be chosen from 9-aminononanoic acid (9), the acid

10-aminodecanoic acid (10), 10-aminoundecanoic acid (11), 12 aminododecanoic acid (12) and 11-aminoundecanoic acid (11). Aminocarboxylic acid can also be branched. By way of example, there may be mentioned N-heptyl-11aminoundecanoic acid.

When this second repeating motif is obtained from a lactam, this lactam can be chosen from pyrrolidinone, 2-piperidinone, enantholactam, caprylolactam, pelargolactam, decanolactam (10), undecanolactam (11) and lauryllactame (12).

When this second repeating unit is a unit corresponding to the formula (Ca diamine) (Cb diacid), it is obtained from the polycondensation of a diamine, the Ca diamine, and of a dicarboxylic acid, the Cb diacid, it being specified that this dicarboxylic acid is not an aromatic dicarboxylic acid.

This Ca diamine can be chosen from aliphatic diamines, cycloaliphatic diamines and alkylaromatic diamines. These Ca diamines can be linear. They can also be branched and comprise at least one alkyl branch on the main chain, this alkyl branch can itself be linear or branched.

The diamines described above for obtaining the first repeating unit can also be used as Ca diamine for obtaining the second repeating unit. Reference is therefore made to the above paragraphs relating to the diamines which can be used for obtaining the first repeating unit for examples of Ca diamines which can be used for obtaining the second repeating unit.

The dicarboxylic acid (Cb diacid) used to obtain the second repeating unit can be chosen from aliphatic dicarboxylic acids and cycloaliphatic dicarboxylic acids. These dicarboxylic acids can be linear. They can also be branched and have at least one alkyl branch on the main chain, this alkyl branch can itself be linear or branched.

When the dicarboxylic acid (Cb diacid) is aliphatic and linear, it can be chosen from succinic acid (4), pentanedioic acid (5), adipic acid (6), heptanedioic acid (7 ), octanedioic acid (8), azelaic acid (9), sebacic acid (10), undecanedioic acid (11), dodecanedioic acid (12), brassylic acid (13), tetradecanedioic acid (14), hexadecanedioic acid (16), octadecanedioic acid (18), octadecenedioic acid (18), eicosanedioic acid (20), docosanedioic acid (22) and dimers fatty acids containing 36 carbons.

The fatty acid dimers mentioned above are dimerized fatty acids obtained by oligomerization or polymerization of unsaturated monobasic fatty acids with a long hydrocarbon chain (such as linoleic acid and oleic acid), as described in particular in the document EP 0 471 566.

When the dicarboxylic acid (Cb diacid) is cycloaliphatic, it can contain the following carbon skeletons: norbornyl methane, cyclohexane, cyclohexyl methane, dicyclohexylmethane, dicyclohexylpropane, di (methylcyclo-hexyl), di (methylcyclohexyl).

Thus, the second repeating unit of the semi-aromatic polyamide may in particular designate the following units 6, 11, 12, 6.10, 6.12, 6.14, 6.18, 10.10, 10.12, 10.14, 10.18 and 12.12.

According to a fourth aspect of the invention, this semi-aromatic polyamide may be a copolymer consisting of first repeating units resulting from the polycondensation reaction of a diamine and an aromatic dicarboxylic acid and second repeating units originating from either a aminocarboxylic acid, either of a lactam, or of the polycondensation of a Ca diamine and a Cb diacid as described above.

Among the possible combinations, the following copolyamides are of particularly marked interest: they are copolyamides corresponding to one of the formulas chosen from 11 / 6.T, 12 / 6.T, 6.10 / 6.T, 6.12 / 6 .T, 10.10 / 6.T, 10.12 / 6.T, 12.12 / 6.T, 11 / 9.T, 12 / 9.T, 6.10 / 9.T, 6.12 / 9.T, 10.10 / 9.T , 10.12 / 9.T, 12.12 / 9.T, 11 / 10.T, 12 / 10.T, 6.10 / 10.T, 6.12 / 10.T, 10.10 / 10.T, 10.12 / 10.T and 12.12 /10.T.

According to a fifth aspect of the invention, this semi-aromatic polyamide may be a copolymer comprising first repeating units derived from the polycondensation reaction of at least one diamine and at least one aromatic dicarboxylic acid and second repeating units derived at least one aminocarboxylic acid, at least one lactam and / or the polycondensation of a Ca diamine and a Cb diacid as described above.

Among the multiple combinations that may be envisaged, mention may especially be made of the copolyamides corresponding to one of the formulas chosen from:

- 6/11 / 10.T, 6/12 / 10.T, 11/12 / 10.T, 11 / 6.10 / 10.T, 12 / 6.10 / 10.T, 11 / 10.6 / 10.T,

12 / 10.6 / 10.T, these copolyamides all comprising a first repeating unit 10.T and two second repeating units,

- 6 / 6.T / 10.T, 11 / 6.T / 10.T, 12 / 6.T / 10.T, these copolyamides each comprising two first repeating units 6.T and 10.T and a second unit repetitive,

- 11 / 9.179.1, 12 / 9.179.1, 11 / 10.T / 10.I, 12 / 10.1710.I, these copolyamides each comprising two first repeating units and a second repeating unit,

- 6/11 / 6.T / 10.T, 11/12 / 6.T / 10.T, these copolyamides each comprising two first repeating units 6.T and 10.T and two second repeating units.

In the context of the present invention, it is advantageous to use first and, where appropriate, second repeating units which are or will be obtained, in whole or in part from diamines, dicarboxylic acids, amino-carboxylic acids and / or bioresourced lactams, that is to say comprising organic carbon derived from biomass, which can be determined according to standard ASTM D6866.

Advantageously, the semi-aromatic polyamide is a polyamide according to the fourth or fifth aspect above.

Aliphatic polyamide

The aliphatic polyamide may be a homopolyamide or a copolyamide and consists of repeating units obtained from at least one aminocarboxylic acid, from at least one lactam and a mixture thereof, as defined above, or from repeating units (diamine in Ca). (diacid in Cb), obtained from the polycondensation of a diamine (diamine in Ca), and a dicarboxylic acid (the diacid in Cb), it being specified that the diamine in Ca is a linear or branched aliphatic diamine and the Cb carboxylic acid is an aliphatic and linear diacid.

Advantageously, the aliphatic polyamide P1 is a polyamide with a Tf of less than 280 ° C., in particular between 170 and 280 ° C.

Advantageously, the aliphatic aliphatic polyamide is a polyamide consisting of repeating units obtained from at least one aminocarboxylic acid, from at least one lactam, in particular PA6, PA11, PA12 or obtained from the polycondensation of a Ca diamine, and a Cb dicarboxylic acid, in particular PA66, PA610, PA612, PA1010 and PA1012.

Advantageously, the aliphatic aliphatic polyamide is a polyamide consisting of repeating units obtained from at least one aminocarboxylic acid, from at least one lactam, of Tf below 280 ° C, in particular between 170 and 280 ° C, in particular PA6, PA11 or PA12.

As regards the polyolefin of the composition

The polyolefin of said composition can be a functionalized or non-functionalized polyolefin or a mixture thereof.

A non-functionalized polyolefin is conventionally a homopolymer or copolymer of alpha olefins or of diolefins, such as for example, ethylene, propylene, butene-1, octene-1, butadiene which can be mixed with a compatible and functional compatibilizer, for example a polyethylene mixed with a maleized Lotader® or a maleized polyethylene.

The functionalized polyolefin can be a polymer of alpha olefins having reactive units (functionalities); such reactive units are the acid, anhydride or epoxy functions. By way of example, mention may be made of the preceding non-functionalized polyolefins grafted or co- or ter polymerized by unsaturated epoxides such as glycidyl (meth) acrylate, or by carboxylic acids or the corresponding salts or esters such as (meth) acrylic acid (this can be totally or partially neutralized by metals such as Zn, etc.) or by anhydrides of carboxylic acids such as maleic anhydride.

The polyolefin of the composition can also be crosslinked or uncrosslinked or be a mixture of at least one crosslinked and / or at least one noncrosslinked.

Crosslinked polyolefin

The polyolefin of said composition according to the invention can be a non-crosslinked polyolefin and / or a crosslinked polyolefin, said non-crosslinked polyolefin and / or a crosslinked being in the form of a phase dispersed in the matrix formed by the polyamide (s). P1 semi-crystalline (s).

Said crosslinked polyolefin results from the reaction of two or at least two products having reactive groups between them.

More particularly, when said polyolefin is a crosslinked polyolefin, it is obtained from at least one product (A) comprising an unsaturated epoxide and from at least one product (B) comprising an unsaturated carboxylic acid anhydride.

The product (A) is advantageously a polymer comprising an unsaturated epoxide, this unsaturated epoxide being introduced into said polymer, either by grafting or by copolymerization.

The unsaturated epoxide can in particular be chosen from the following epoxides:

aliphatic glycidyl esters and ethers such as allylglycidylether, vinylglycidylether, glycidyl maleate and itaconate, glycidyl acrylate and methacrylate, and

- alicyclic glycidyl esters and ethers such as 2-cyclohexene-1glycidylether, cyclohexene-4,5-diglycidyl carboxylate, cyclohexene-4-glycidyl carboxylate, 5-norbornene-2-methyl-2-glycidyl carboxylate and endocisbicyclo ( 2,2,1) -5-heptene-2,3-diglycidyl dicarboxylate.

According to a first form, the product (A) is a polyolefin grafted with an unsaturated epoxide. By polyolefin is meant a homopolymer or copolymer comprising one or more olefin units such as ethylene, propylene, butene-1 units or any other alpha-olefin. As an example of a polyolefin, there may be mentioned:

- polyethylene and, in particular, low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE) and very low density polyethylene (VLDPE); polypropylene; ethylene / propylene copolymers; elastomeric polyolefins such as ethylenepropylene (EPR or EPM) or ethylene-propylene-diene monomer (EPDM); or also metallocene polyethylenes obtained by monosite catalysis;

- styrene / ethylene-butene / styrene block copolymers (SEBS); styrene / butadiene / styrene block copolymers (SBS); styrene / isoprene / styrene block copolymers (SIS); or also styrene / ethylenepropylene / styrene block copolymers;

- the copolymers of ethylene and of at least one product chosen from the salts of unsaturated carboxylic acids, the esters of unsaturated carboxylic acids and the vinyl esters of saturated carboxylic acids. The polyolefin can in particular be a copolymer of ethylene and of alkyl (meth) acrylate or a copolymer of ethylene and of vinyl acetate.

According to a second form, the product (A) is a copolymer of alpha-olefin and an unsaturated epoxide and, advantageously, a copolymer of ethylene and of an unsaturated epoxide. Advantageously, the amount of unsaturated epoxide can represent up to 15% by weight of the copolymer (A), the amount of ethylene representing for its part at least 50% by weight of the copolymer (A).

Mention may more particularly be made of copolymers of ethylene, of a vinyl ester of saturated carboxylic acid and of an unsaturated epoxide, as well as copolymers of ethylene, of an alkyl (meth) acrylate and of an unsaturated epoxide. Preferably, the (meth) acrylate alkyl comprises from 2 to 10 carbon atoms. Examples of alkyl acrylates or methacrylates which can be used are in particular methyl acrylate, methyl methacrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate and sodium acrylate. 2-ethylhexyl.

According to an advantageous version of the invention, the product (A) is a copolymer of ethylene, methyl acrylate and glycidyl methacrylate or a copolymer of ethylene, n-butyl acrylate and glycidyl methacrylate . In particular, it will be possible to use the product sold by the company ARKEMA under the name LOTADER® AX8900.

According to another form of the invention, the product (A) is a product having two epoxide functions, such as for example the diglycidyl ether of bisphenol A (DGEBA).

The product (B) is advantageously a polymer comprising an unsaturated carboxylic acid anhydride, this unsaturated carboxylic acid anhydride being introduced into said polymer, either by grafting or by copolymerization.

Examples of unsaturated dicarboxylic acid anhydrides which can be used as constituents of product (B) are in particular maleic anhydride, itaconic anhydride, citraconic anhydride and tetrahydrophthalic anhydride.

According to a first form, the product (B) is a polyolefin grafted with an unsaturated carboxylic acid anhydride. As seen above, a polyolefin is a homopolymer or copolymer comprising one or more olefin units such as ethylene, propylene, butene-1 units or any other alpha-olefin. This polyolefin can in particular be chosen from the examples of polyolefins listed above for the product (A), when the latter is a polyolefin grafted with an unsaturated epoxide.

According to a second form, the product (B) is a copolymer of alpha-olefin and of an unsaturated carboxylic acid anhydride and, advantageously, a copolymer of ethylene and of an unsaturated carboxylic acid anhydride. Advantageously, the amount of unsaturated carboxylic acid anhydride can represent up to 15% by weight of the copolymer (B), the amount of ethylene representing for its part at least 50% by weight of the copolymer (B).

Mention may more particularly be made of copolymers of ethylene, of a vinyl ester of saturated carboxylic acid and of an unsaturated carboxylic acid anhydride, as well as copolymers of ethylene, of a (meth) acrylate. alkyl and an unsaturated carboxylic acid anhydride. Preferably, the (meth) acrylate alkyl comprises from 2 to 10 carbon atoms. The alkyl acrylate or methacrylate can be chosen from those mentioned above for the product (A).

According to an advantageous version of the invention, the product (B) is a copolymer of ethylene, of an alkyl (meth) acrylate and of an unsaturated carboxylic anhydride. Preferably, the product (B) is a copolymer of ethylene, ethyl acrylate and maleic anhydride or a copolymer of ethylene, butyl acrylate and maleic anhydride. We can in particular use the products marketed by the company ARKEMA under the names LOTADER® 4700 and LOTADER® 3410.

It would not go beyond the scope of the invention if part of the maleic anhydride of product (B), according to the first and second forms which have just been described, was partly hydrolyzed.

Advantageously, the contents by weight of product (A) and of product (B), which are noted respectively [A] and [B], are such that the ratio [B] / [A] is between 3 and 14 and , advantageously, between 4 and 9.

In the composition according to the invention, the crosslinked polyolefin can also be obtained from the products (A), (B) as described above and from at least one product (C), this product (C) comprising a unsaturated carboxylic acid or an alpha-omegaaminocarboxylic acid.

The product (C) is advantageously a polymer comprising an unsaturated carboxylic acid or an alpha-omega-aminocarboxylic acid, one or the other of these acids being introduced into said polymer by copolymerization.

Examples of unsaturated carboxylic acids which can be used as constituents of the product (C) are in particular acrylic acid, methacrylic acid, the carboxylic acid anhydrides mentioned above as constituents of the product (B), these anhydrides being completely hydrolysed.

Examples of alpha-omega-aminocarboxylic acids which can be used as constituents of product (C) are in particular 6-aminohexanoic acid, 11 aminoundecanoic acid and 12-aminododecanoic acid.

The product (C) can be a copolymer of alpha-olefin and an unsaturated carboxylic acid and, advantageously, a copolymer of ethylene and an unsaturated carboxylic acid. Mention may in particular be made of the completely hydrolyzed copolymers of the product (B).

According to an advantageous version of the invention, the product (C) is a copolymer of ethylene and (meth) acrylic acid or a copolymer of ethylene, of an (meth) acrylate and of (meth) acrylic acid. The amount of (meth) acrylic acid can represent up to 10% by weight and, preferably, from 0.5 to 5% by weight of the copolymer (C). The amount of alkyl (meth) acrylate is generally between 5 and 40% by weight of the copolymer (C).

Advantageously, the product (C) is a copolymer of ethylene, butyl acrylate and acrylic acid such as Escor ™ 5000 from ExxonMobil.

Preferably, the product (C) is a copolymer of ethylene, butyl acrylate and acrylic acid. We can in particular use the product sold by BASF under the name LUCALENE® 3110.

The dispersed crosslinked polyolefin phase can of course arise from the reaction of one or more products (A) with one or more products (B) and, if necessary, with one or more products (C).

As already described in document WO 2011/015790, it is possible to use catalysts making it possible to accelerate the reaction between the reactive functions of the products (A) and (B). Reference will therefore be made to the teaching of this document as regards examples of catalysts, which can be used in a content by weight of between 0.1 and 3% and, advantageously, between 0.5 and 1% of the total weight of products (A), (B) and, where applicable, (C).

Advantageously, the contents by weight of product (A), of product (B), of product (C) which are noted respectively [A], [B] and [C] are such that the ratio [B] / ([ A] + [C]) is between 1.5 and 8, the weight contents of products (A) and (B) being such that [C] <[A],

Advantageously, the ratio [B] / ([A] + [C]) is between 2 and 7.

Uncrosslinked polyolefin

The composition according to the invention may comprise at least one uncrosslinked polyolefin, said uncrosslinked polyolefin having a dispersed phase in the matrix formed by the semi-crystalline polyamide (s) P1 (s).

The term “non-crosslinked polyolefin” means a homopolymer or copolymer comprising one or more olefin units such as ethylene, propylene, butene1 units or any other alpha-olefin as defined above.

Advantageously, said composition comprises at least one crosslinked polyolefin as defined above and at least one non-crosslinked polyolefin as defined above.

Regarding the masterbatch

The masterbatch comprises at least one fluorinated compound with Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C.

The masterbatch advantageously comprises from 1 to 30% by weight, in particular from 1 to 20% by weight of fluorinated compound of Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C relative to the total weight of the constituents of the masterbatch.

Advantageously, said fluorinated compound of Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorine (FEP), l ' ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular PTFE.

In one embodiment, the masterbatch used with said composition further comprises a polyolefin and additives, provided that the fluorinated compound is in a proportion comprised from 0.01% by weight to 0.3% by weight relative to the weight total of said composition and masterbatch.

This is therefore the final proportion of fluorinated compound in the mixture constituted by said composition and said masterbatch.

It is obvious that the polyolefin can be a mixture of polyolefins.

Said polyolefin of the masterbatch is as defined for the polyolefin of said composition. It can be the same or different from that used in said composition.

Advantageously, it is chosen from Lotader® AX8900, Lotader® 4700 and Escor ™ 5000 from ExxonMobil or a mixture of these

In another embodiment, the masterbatch used with said composition further comprises a polyamide P2 and additives, provided that the fluorinated compound is in a proportion comprised from 0.01% by weight to 0.3% by weight relative to the total weight of said composition and of the masterbatch.

Polyamide P2 can be an aliphatic polyamide as defined for P1 or a semi-aromatic polyamide as defined for P1.

Advantageously, the polyamide P2 is an aliphatic polyamide.

It is obvious that polyamide P2 can be a mixture of polyamides.

In yet another embodiment, the masterbatch used additionally comprises a polyamide P2, a polyolefin and additives, provided that the fluorinated compound is in proportion ranging from 0.01% by weight to 0.3% by weight per relative to the total weight of said composition and of the masterbatch.

Polyamide P2, polyolefin and additives are as defined above.

It is obvious that the polyolefin can be a mixture of polyolefins and that the polyamide P2 can be a mixture of polyamides.

Advantageously, the fluorinated compound of said masterbatch, whether it is based on polyamide P2, polyolefin or polyamide P2 and polyolefin, is polytetrafluoroethylene (PTFE).

Additives

The masterbatch according to the invention can also further comprise at least one additive.

This additive can in particular be chosen from adjuvants which aid in processing (or processing aids), plasticizers, fillers, stabilizers (UV and / or heat), dyes, mold release agents, flame retardants , surfactants, optical brighteners, antioxidants, especially copper stabilizers, and mixtures thereof.

Among the adjuvants which aid in the transformation or processing aids, mention may be made of stearates, such as calcium or zinc stearates, natural waxes.

The weight proportion in processing aids is conventionally between 0.01 and 0.3% by weight, advantageously between 0.02 and 0.1% by weight, relative to the total weight of the composition.

Among the plasticizers, it is possible in particular to use benzene sulfonamide derivatives, including n-butyl benzene sulfonamide (BBSA).

The proportion by weight of plasticizer can represent up to 25% by weight and is advantageously between 3 and 20% by weight, relative to the total weight of the composition.

Among the fillers, mention may be made of silica, graphite, expanded graphite, carbon black, carbon fibers, glass beads, kaolin, magnesia, slag, talc, nanofillers (carbon nanotubes ), pigments, metal oxides (titanium oxide), metals, fibers (aramids, glass, carbon).

Depending on the nature of the fillers, the amount of the latter can represent up to 50% by weight, advantageously, up to 30% by weight, of the total weight of the composition.

According to another aspect, the present invention relates to a process for preparing a monolayer structure or at least one layer of a multilayer structure, in particular in the form of a tube or film, characterized in that it comprises a step d extrusion of a composition comprising at least one polyamide P1 and at least one polyolefin with a masterbatch comprising at least one fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C, such as determined according to ISO 11357-3: 2013, as defined above.

All the characteristics described for part 3 "Use" are valid for said process.

Advantageously, the extrusion step of said process is carried out with an initial mixture of said composition and said masterbatch.

The masterbatch and the composition are therefore mixed beforehand to be extruded at the same time.

Advantageously, the extrusion step of said process is carried out by lateral gavage of said masterbatch in the molten phase comprising said composition.

In this embodiment, the composition of the invention is therefore introduced in the form of granules beforehand into the extruder and the masterbatch is added by lateral gavage when said granules of said composition are in the molten state.

According to another aspect, the present invention relates to the use of a composition and of a masterbatch as defined above, to constitute a monolayer structure or at least one layer of a multilayer structure.

Advantageously, said structure is a tubular structure.

Advantageously, said structure is a film.

The present invention will now be illustrated by examples of different compositions with masterbatches whose use is the subject of the present invention without being limited in any way thereto.

Advantageous embodiments of the process of the invention

In a first variant of the invention, the masterbatch comprises a fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C and the composition comprises an aliphatic polyamide and at least one polyolefin, in particular PA6, PA11, PA 12, PA6.6, PA610, PA612, PA1010 and PA1012, said fluorinated compound being in proportion ranging from 0.01% by weight to 0.3% by weight relative to the total weight of said composition and masterbatch, and said masterbatch comprising a polyamide P2, in particular an aliphatic polyamide, PA 11 or PA 12, and additives.

Advantageously, in this first variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE.

Advantageously, in this first variant, the polyamide P1 is PA6, PA 11 or PA12, in particular PA 11.

Advantageously, in this first variant, the polyamide P2 is PA 11 or PA12, in particular PA 11.

Advantageously, in this first variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P1 is PA6, PA 11 or PA12, in particular PA 11.

Advantageously, in this first variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P2 is PA 11 or PA12, in particular PA 11.

Advantageously, in this first variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P1 is PA6, PA 11 or PA12, in particular PA 11, and polyamide P2 is PA 11 or PA12, in particular PA 11.

In a second variant of the invention, the masterbatch comprises a fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C and the composition comprises a semi-aromatic polyamide and at least one polyolefin , in particular a semi-aromatic PA chosen from one of those described in the fourth aspect of the polyamide P1 part of the composition of the invention, said fluorinated compound being in proportion of 0.01% by weight at 0, 3% by weight relative to the total weight of said composition and of the masterbatch, and said masterbatch comprising a polyamide P2, in particular an aliphatic polyamide, in particular PA 11 or PA 12, and additives.

Advantageously, in this second variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE.

Advantageously, in this second variant, the polyamide P1 is 11 / 10T.

Advantageously, in this second variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P1 is 11 / 10T.

Advantageously, in this second variant, the polyamide P2 is PA 11 or PA12, in particular PA 11.

Advantageously, in this second variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P2 is PA 11 or PA12, in particular PA 11.

Advantageously, in this second variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P1 is 11 / 10T and polyamide P2 is PA 11 or PA12, in particular PA 11.

In a third variant of the invention, the masterbatch comprises a fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C and the composition comprises an aliphatic polyamide and at least one polyolefin, in particular PA11 or PA 12, said fluorinated compound being in proportion ranging from 0.01% by weight to 0.3% by weight relative to the total weight of said composition and of the masterbatch, and said masterbatch comprising a polyamide P2, in in particular a semi-aromatic PA chosen from one of those described in the fourth aspect of the polyamide P1 part of the composition of the invention, and of the additives.

Advantageously, in this third variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE.

Advantageously, in this third variant, the polyamide P1 is PA 11 or PA12, in particular PA 11.

Advantageously, in this third variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P1 is PA 11 or PA12, in particular PA 11.

Advantageously, in this third variant, the polyamide P2 is 11 / 10T.

Advantageously, in this third variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P2 is 11 / 10T.

Advantageously, in this third variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P1 is PA 11 or PA12, in particular PA 11 and polyamide P2 is 11 / 10T.

In a fourth variant of the invention, the masterbatch comprises a fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C and the composition comprises a semi-aromatic polyamide and at least one polyolefin , in particular a semi-aromatic PA chosen from one of those described in the fourth aspect of the polyamide P1 part of the composition of the invention, said fluorinated compound being in proportion of 0.01% by weight at 0, 3% by weight relative to the total weight of said composition and of the masterbatch, and said masterbatch comprising a polyamide P2, in particular a semi-aromatic PA chosen from one of those described in the fourth aspect of the polyamide P1 part of the composition of the invention, and of the additives.

Advantageously, in this fourth variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE.

Advantageously, in this fourth variant, the polyamide P1 is 11 / 10T.

Advantageously, in this fourth variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P1 is 11 / 10T.

Advantageously, in this fourth variant, the polyamide P2 is 11/1 OT.

Advantageously, in this fourth variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular the PTFE and polyamide P2 is 11/1 OT.

Advantageously, in this fourth variant, the fluorinated compound is chosen from polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), ethylene propylene perfluorinated (FEP), ethylene tetrafluoroethylene (ETFE) and polyethylene chlorotrifluoroethylene (ECTFE), in particular PTFE and polyamide P1 is 11/1 OT and polyamide P2 is 11/1 OT.

EXAMPLES.

Formulation of compositions

The compositions tested were prepared from the following products:

11 / 10.T: semi-aromatic polyamide, of molar ratio 11 / 10.T equal to 0.7, obtained by polycondensation of 11-aminocarboxylic acid, 1,10-decanediamine and terephthalic acid, at a transition temperature vitreous Tg of 88 ° C, a melting temperature Tf of 260 ° C, an inherent viscosity of 1.22 (measured according to standard ISO 307) and an enthalpy of fusion of 47 J / g

Lotader®AX8900 copolymer of ethylene, methyl acrylate and glycidyl methacrylate (Et / MA / GMA - 68/24/8 by weight) (Arkema)

Lotader® 4700: copolymer of ethylene, ethyl acrylate and maleic anhydride (Et / EA / MAH - 69/30/1 by weight) (Arkema)

Escor ™ 5000: copolymer of ethylene and acrylic acid (ExxonMobil)

TAFMER ™ MH7020: Acid modified polyolefin (Mitsui)

Orevac® IM 800: Arkema

Naugard®445: CAS N °: 10081-67-1 (Addivant)

MM Black 6005 euthylen® c4 (BASF)

Polyad® PB 201 (lodine 201): antioxidant additive based on Kl and Cul (BASF)

Polymist® F284: PTFE Tf = 325-335 ° C (Solvay)

Polymist ™ F5A: PTFE Tf = 320-330 ° C (Solvay) Dynamar ™ fx5914: Fluoropolymer, Tf = 195-215 ° C (3M)

Example 1: Preparation of the masterbatch.

The master mix 11 / 10.T + PTFE (Polymist® F284 or F5A from Solvay): 90/10 by weight was prepared on twin Werner 40 screws.

Example 2: Preparation of the polyamide P1 and masterbatch compounds on twin screw of the Werner 40 type

The compounding flow rate was 75 kg / h for a screw speed of 300 rpm and a flat temperature profile at 280 ° C., under an absolute vacuum of 500 mbar.

Example 3: Extrusion of the 5 * 1 mm tubes on a Maillefer extruder

Temperature 270 ° c

Speed: 30 m / min

Duration: 2 hours

The polyamide P1 and masterbatch compositions were extruded in the form of tubes 5 mm in diameter and 1 mm thick (5 * 1 mm) under the conditions described above. It was observed whether, during this transformation by extrusion, deposits (tears) formed on the extrusion die with the following correspondences: Tears of die:

Bad:> 1.5 mm in 120 minutes

Medium: between 0.7 and 1.5 mm in 120 minutes

Good: between 0.3 and 0.7 mm in 120 minutes

Very good: between 0 and 0.3 mm

Pressure stability and calibration were also looked at with the following correspondences:

Pressure stability: for 5 hours of extrusion

Good: stable after 15 min Average: stable after 60 min Poor: pressure drop for more than 60 min

5 * 1 tube calibration:

Good: RAS

Medium: some difficulties

Bad: extrusion problem

The thermal resistance at 170 ° C in air, half-life in h (corresponds to the time when a breakage rate of 50% is obtained, with the DIN53758 shock at -40 ° C as criteria) was evaluated.

Thermal resistance at 170 ° c:

Good: <50% of impact break DI N -40:> 1000 hours

Bad: <50% breakage at impact DI N -40: <1000 hours

VW shock -40 ° C according to standard VWTL-52435 §6.5, PV 3905 in% of breakage

Good: <40% breakage

Bad:> 40% breakage

The following tables I to III present the results obtained on the tears of the die, the pressure stability, the calibration as well as the mechanical properties and the thermal resistance with different comparative compositions (COMP) and different compositions of the invention (polyamide P1 and masterbatch: INV)

TABLE I

COMP 1 COMP 2 COMP 3 COMP 4 COMP 5 COMP 6 COMP 7 11 / 10.T 67.75 67.9 67.75 67.4 66.9 60.4 62.9 Lotader® 4700 15 24 24 24 24 24 24 Lotader® ax8900 7.5 4 4 4 4 4 4 ESCOR 5000 7.5 2 2 2 2 2 2 MM black 6005 euthylen® c4 0.9 0.9 0.9 0.9 0.9 0.9 0.9 MM Polymist® F5A base 11 / 10.T 7.5 5 Polyad® PB 201 0.7 0.7 0.7 0.7 0.7 0.7 0.7 PTFE polymist® F284 0.5 1 naugard® 445 0.5 0.5 0.5 0.5 0.5 0.5 0.5 dynamar® fx5914 0.15 0.15 PTFE EQUIVALENT% 0.5 1 0.75 0.5 EXTRUSION tear drop: deposit bad way way way very good very good Well pressure stability Well Well Well way way bad bad 5 * 1 tube calibration Well Well Well way way bad bad TUBES PROPERTY thermal resistance 170 ° c Well Well Well bad bad bad bad VW shock -40 ° C Well Well Well bad bad bad bad

INV 1 INV2 INV 3 INV 4 INV 5 11 / 10.T 64.9 66.4 66.9 67.4 67.65 Lotader®4700 24 24 24 24 24 Lotader® ax8900 4 4 4 4 4 ESCOR 5000 2 2 2 2 2 MM black 6005 euthylen® c4 0.9 0.9 0.9 0.9 0.9 MM Polymist® F5A base 11 / 10.T 3 1.5 1 0.5 0.25 Polyad® PB 201 0.7 0.7 0.7 0.7 0.7 naugard® 445 0.5 0.5 0.5 0.5 0.5 PTFE EQUIVALENT% 0.3 0.15 0.1 0.05 0025 EXTRUSION tear drop: deposit very good very good very good Well Well pressure stability way Well Well Well Well 5 * 1 tube calibration way Well Well Well Well TUBES PROPERTY thermal resistance 170 ° c Well Well Well Well Well chocVW-40 ° C Well Well Well Well Well

COMP8 COM P 9 INV 6 INV 7 11 / 10.T 67.75 67.9 64.9 66.4 IM800 25 25 TAFMER® MH7020 25 25 MM black 6005 euthylen® c4 0.9 0.9 0.9 0.9 MM Polymist® F5A base 11 / 10.T 1 1 Polyad® PB 201 0.7 0.7 0.7 0.7 naugard® 445 0.5 0.5 0.5 0.5 dynamar®fx5914 0.15 0.15 PTFE EQUIVALENT% 0.1 0.1 EXTRUSION tear drop: deposit way way Well Well pressure stability Well Well Well Well 5 * 1 tube calibration Well Well Well Well TUBES PROPERTY thermal resistance 170 ° c Well Well Well Well VW-40 ° C shock Well Well Well Well

These results therefore show that the addition of fluorinated compound in the form of masterbatch to a composition comprising at least one polyamide P1 and at least one polyolefin makes it possible on the one hand to reduce by 10 the proportion of fluorinated compound present in the total composition, to reduce die tears while retaining the properties of pressure stability and calibration as well as the mechanical properties and the thermal resistance.

Claims (6)

claims 1. Use of a masterbatch comprising at least one fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C, as determined according to ISO 11357-3: 2013, with a composition comprising at least one semi-crystalline polyamide P1 and at least one polyolefin, for reducing the tears of the die during the extrusion of said composition and of said masterbatch in the form of a monolayer structure, in particular in the form of a tube or film, all by retaining good calibration and good mechanical and thermal properties of said monolayer structure. 2. Use according to claim 1, characterized in that the fluorinated compound is in proportion ranging from 0.01% by weight to 0.3% by weight relative to the total weight of said composition and of the masterbatch. 3. Use according to claim 2, characterized in that the masterbatch additionally comprises a polyolefin and additives, provided that the fluorinated compound is in proportion ranging from 0.01% by weight to 0.3% by weight relative to the total weight of said composition and of the masterbatch. 4. Use according to claim 2, characterized in that the masterbatch additionally comprises a polyamide P2 and additives, provided that the fluorinated compound is in proportion ranging from 0.01% by weight to 0.3% by weight per relative to the total weight of said composition and of the masterbatch. 5. Use according to claim 2, characterized in that the masterbatch additionally comprises a polyamide P2, a polyolefin and additives, provided that the fluorinated compound is in proportion comprised from 0.01% by weight to 0.3% by weight relative to the total weight of said composition and of the masterbatch. 6. Use according to claim 4 or 45, characterized in that the polyamide P2 is a semi-aromatic polyamide or an aliphatic polyamide. 7. Use according to one of claims 1 to 6, characterized in that the fluorinated compound is polytetrafluoroethylene (PTFE). 8. Use according to one of claims 1 to 7, characterized in that the aliphatic polyamide P1 is a polyamide with a Tf of less than 280 ° C, in particular between 170 ° C and 280 ° C, as determined according to ISO 11357-3 : 2013. 9. Use according to one of claims 1 to 7, characterized in that the polyamide P1 is a semi-aromatic polyamide. 10. Use according to one of claims 1 to 9, characterized in that said polyolefin of said composition is a functionalized polyolefin and / or a non-functionalized polyolefin. 11. Use according to one of claims 1 to 9, characterized in that said polyolefin of said composition is a non-crosslinked polyolefin and / or a crosslinked polyolefin. 12. Use according to one of claims 1 to 9, characterized in that said polyolefin of said composition is a crosslinked polyolefin, the crosslinked polyolefin being obtained from: at least one product (A) comprising an unsaturated epoxide and at least one product (B) comprising an unsaturated carboxylic acid anhydride, 13. Use according to Claim 12, characterized in that the said crosslinked polyolefin is obtained from the products (A), (B) and from at least one product (C) comprising an unsaturated carboxylic acid or an alpha-omega-aminocarboxylic acid, 14. Use according to claim 12 or 13, characterized in that the product (A) is a polyolefin grafted with an unsaturated epoxide or a copolymer of alpha-olefin and an unsaturated epoxide. 15. Use according to one of claims 12 to 14, characterized in that the product (A) is a copolymer of ethylene, of a vinyl ester of saturated carboxylic acid and of an unsaturated epoxide or a copolymer of ethylene, an alkyl (meth) acrylate and an unsaturated epoxide. 16. Use according to one of claims 12 to 15, characterized in that the product (B) is a polyolefin grafted with an unsaturated carboxylic acid anhydride or a copolymer of alpha-olefin and an acid anhydride carboxylic acid. 17. Use according to claim 16, characterized in that the product (B) is a copolymer of ethylene, of a vinyl ester of saturated carboxylic acid and of an unsaturated carboxylic acid anhydride or a copolymer of l ethylene, an alkyl (meth) acrylate and an unsaturated carboxylic acid anhydride. 18. Use according to one of claims 13 to 17, characterized in that the product (C) is a copolymer of alpha-olefin and of an unsaturated carboxylic acid. 19. Use according to claim 18, characterized in that the product (C) is a copolymer of ethylene and (meth) acrylic acid or a copolymer of ethylene, of a (meth) acrylate alkyl and (meth) acrylic acid. 20. Use according to one of claims 12 to 19, characterized in that said composition also comprises at least one non-crosslinked polyolefin. 21. Method for preparing a monolayer structure or at least one layer of a multilayer structure, in particular in the form of a tube or film, characterized in that it comprises a step of extruding a composition comprising at least at least one polyamide P1 and at least one polyolefin with a masterbatch comprising at least one fluorinated compound having a Tf greater than or equal to 240 ° C, in particular greater than or equal to 280 ° C, as determined according to ISO 113573: 2013, such as defined in claim 1. 22. The method of claim 21, characterized in that the extrusion step is carried out with an initial mixture of said composition and said masterbatch. 23. The method of claim 21, characterized in that the extrusion step is carried out by lateral gavage of said masterbatch in the molten phase comprising said composition. 24. Use of a composition and of a masterbatch as defined in any one of claims 1 to 20 to constitute a monolayer structure or at least one layer of a multilayer structure. 25. Use of a composition and of a masterbatch according to claim 24, 5 characterized in that said structure is a tubular structure. 26. Use of a composition and of a masterbatch according to claim 24, characterized in that said structure is a film.