MIXTURES OF POLYARYLETHERCETONES PRESENTING

IMPROVED IMPACT RESISTANCE, ELONGATION AT RUPTURE AND FLEXIBILITY

[Technical area]

The present patent application relates to blends of polymers based on poly (aryletherketones) exhibiting improved impact resistance, elongation at break and improved flexibility. It also relates to a method of manufacturing such mixtures, as well as their use for the manufacture of parts, in particular in the field of petroleum, cables, aeronautics, automobiles, electronics, electrical engineering, composites, additive manufacturing and medical devices.

[Prior art]

Poly (aryletherketones) (PAEK) are high performance thermoplastic polymers suitable for use in extreme environments due to their high melting point combined with excellent mechanical properties and exceptional fire and chemical resistance. PAEKs can thus compete with metals with the advantage of being lighter and of being able to be transformed with conventional techniques for processing thermoplastic materials.

Notwithstanding these advantageous properties, it is sometimes necessary to formulate the poly (aryletherketones) in order to meet specific specifications. Thus, it is possible to seek a higher impact resistance in order to manufacture parts which are particularly resistant to the propagation of cracks. In addition, greater flexibility makes it possible to accommodate new modes of use and positioning of parts, with a greater possibility of bending, for example allowing easier assembly in a restricted space such as an engine or a winding on a mandrel of smaller radius.

It is known, for example from US 2009/0292073 A1, that the addition of polyolefins such as polyoctenylene makes it possible to improve the impact resistance of the poly (aryletherketone).

Patent application US 2005/0004326 A1 furthermore proposes to improve the impact resistance and the elongation at break of poly (etherketones) by formulating them with a polysiloxane. In order to improve the compatibility of the polysiloxane, the latter preferably has a very high molecular weight. However, the dispersion of the polysiloxane in these mixtures is not always satisfactory.

Also, these mixtures can present manufacturing difficulties, from the compounding phase but also during shaping.

Moreover, US Pat. No. 8,013,251 B2 teaches that the addition of a copolymer containing polyimide and polysiloxane blocks makes it possible to increase the ductility of poly (aryletherketones). However, the examples demonstrate that only certain copolymers allow compounding, and that an amount of at least 50% by weight is required to improve ductility. Now, the presence of such a quantity of copolymer affects the properties of the poly (aryletherketone) matrix, in particular its temperature resistance and its dimensional stability.

Patent application US 2017/0242372 A1 describes a conveyor belt made from a mixture comprising a poly (etherimide) modified with a polysiloxane, a polyetherimide, a poly (etheretherketone) and a conductive material.

However, all the mixtures offered still do not meet the specifications for certain demanding applications.

[Summary of the invention]

The object of the invention is therefore to provide mixtures based on poly (aryletherketones) exhibiting impact resistance, elongation at break and improved flexibility compared with mixtures of the state of the art.

Indeed, the present invention is based on the observation that a mixture based on ternary poly (aryletherketone), comprising a polysiloxane and a block copolymer with polysiloxane blocks, has excellent impact resistance properties and improved flexibility compared to comparable mixtures comprising only two of these components.

In view of the current results, it is assumed that the advantageous mechanical properties are linked in particular to the presence of the block copolymer containing a polysiloxane block, which ensures better dispersion of the polysiloxane. In fact, the study of the microstructure revealed that the mixtures according to the invention exhibit a finer dispersion compared to mixtures of poly (aryletherketone) containing only the polysiloxane. It is believed that the polysiloxane block block copolymer facilitates the dispersion of polysiloxane in the poly (aryletherketone) matrix by acting as a surfactant.

On this basis, it could be validated that the ternary mixtures of poly (aryletherketone) according to the invention exhibit improved impact resistance, elongation at break and improved flexibility. Such

mixtures can therefore meet demanding specifications, accommodate new modes of use and placement of parts and reduce the stress required for a given deformation and thus fatigue to extend the life of the parts.

Also, according to a first aspect, the subject of the invention is a mixture of polymers, comprising:

(i) a poly (aryletherketone);

(ii) a polysiloxane; and

(iii) a block copolymer containing polysiloxane blocks.

According to a preferred embodiment, the mixture in which the poly (aryletherketone) has a viscosity, as measured at 380 ° C. and 1 Hz, greater than 100 Pa-s, preferably greater than 200 Pa-s and very particularly greater at 300 Pa-s.

Preferably, the poly (aryletherketone) is selected from the group consisting of poly-ether-ketone (PEK), polyether-ether-ketone (PEEK), poly-ether-ether-ketone-ketone (PEEKK), poly-ether- ether-ketone-ketone (PEKK), poly-ether-ketone-ether-ketone-ketone (PEKEKK), poly-ether-ether-ketone-ether-ketone (PEEKEK), poly-ether-ether-ether-ketone (PEEEK) ), and poly-ether-diphenyl-ether-ketone (PEDEK), their mixtures and their copolymers with one another or with other members of the poly (aryletherketone) family.

Advantageously, the mixture of polymers according to the invention comprises 50 to 98, preferably 60 to 96, more preferably 70 to 95% by weight of poly (aryletherketone).

Preferably, the poly (aryletherketone) is a poly (etherketonketone) (PEKK), a poly (etheretherketone) (PEEK) or a mixture thereof.

The PEKK can in particular have a percentage by weight of terephthalic units relative to the sum of the terephthalic and isophthalic units of between 50 and 90%.

The polysiloxane may have a viscosity, as measured at 380 ° C. and 1 Hz, greater than 100 Pa-s, preferably greater than 200 Pa-s and very particularly greater than 300 Pa-s.

Preferably, the mixture of polymers according to the invention comprises 1 to 49, preferably 2 to 40, more preferably 2.5 to 25% by weight of polysiloxane.

Preferably, the block copolymer containing polysiloxane blocks has a viscosity, as measured at 380 ° C. and 1 Hz, greater than 100 Pa-s, preferably greater than 200 Pa-s and very particularly greater than 300 Pa-s.

Advantageously, the mixture of polymers according to the invention comprises 1 to 49, preferably 2 to 40, more preferably 2.5 to 30% by weight of block copolymer containing polysiloxane blocks.

Preferably, the block copolymer containing polysiloxane blocks further comprises blocks chosen from poly (etherimide), poly (aryletherketone), poly (arylethersulfone), poly (phenylene sulfide), poly (arylamideimide), poly (phenylene), poly (benzimidazole), or polycarbonate.

According to a second aspect, the invention relates to a process for preparing a mixture of polymers according to the invention, comprising the steps of:

(a) contacting a poly (aryletherketone), a polysiloxane and a polysiloxane block block copolymer under conditions where the poly (aryletherketone) melts; and

(b) allow said mixture to cool to obtain the mixture.

Preferably, step (a) is carried out in a twin-screw extruder or a co-kneader.

According to a third aspect, the invention relates to the use of a mixture of polymers according to the invention for the manufacture of parts, in particular by molding, in particular by injection molding or by compression molding, by additive manufacturing by filament fusion (FFF), film or sheet extrusion, calendering extrusion, tube or pipe extrusion, sheathing extrusion, spinning, rotational molding, thermoforming, coating, additive manufacturing by laser sintering, coating from powder or for the production of composites.

Finally, according to a fourth aspect, the invention relates to a part, manufactured at least partially from the mixture of polymers according to the invention.

[Brief description of the figures]

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

Fig. 1 the mixture of Example 3 observed by scanning electron microscopy (SEM) under X400 magnification;

Fig. 2 the mixture of Example 4 observed by scanning electron microscopy (SEM) under X400 magnification; and

Fig. 3 the mixture of example Comp 2 observed by scanning electron microscopy

(SEM) under X400 magnification.

[Description of the embodiments]

Definition of terms

The term “polymer mixture” is understood to denote a macroscopically homogeneous polymer composition. The term also encompasses such compositions composed of phases immiscible with one another and dispersed on a micrometric scale.

The term “copolymer” is understood to denote a polymer resulting from the copolymerization of at least two types of chemically different monomer, called comonomers. A copolymer is therefore formed from at least two repeating units. It can also be formed from three or more repeat patterns.

More specifically, the term “block copolymer with polysiloxane blocks” is understood to denote copolymers in the aforementioned sense, in which at least two distinct homopolymer blocks are linked by covalent bond and one of the blocks is composed of siloxane repeat units. . The length of the blocks can be variable. Preferably, the blocks are composed of 1 to 1000, preferably 1 to 100, and in particular 1 to 50 repeating units, respectively. The bond between the two homopolymer blocks can sometimes require an intermediate non-repeating pattern called a terminal block.

The term “dispersion” is understood to denote a heterogeneous composition, in particular comprising several phases. In the mixture according to the invention, the poly (aryletherketone) generally forms the continuous phase and the other components one or more dispersed phases.

The term “viscosity” is understood to denote the viscosity as measured at 380 ° C. and at 1 Hz under an inert atmosphere (N2), by means of an “Anton Paar, MCR 302” oscillatory rheometer, in plane / plane geometry.

The term “crystallinity rate” is understood to denote the crystallinity rate as calculated from measurements of X-ray scattering at wide angles (WAXS), on a device of the Nano-inXider ® type with the following conditions:

- Wavelength: main Kal line of copper (1.54 Angstroms).

- Generator power: 50 kV - 0.6 mA.

- Observation mode: transmission

- Counting time: 10 minutes

A spectrum of the intensity diffused as a function of the diffraction angle is thus obtained. This spectrum makes it possible to identify the presence of crystals, when peaks are visible on the spectrum in addition to the amorphous halo. In the spectrum, it is possible to measure the area of ​​the crystal peaks (denoted A) and the area of ​​the amorphous halo (denoted AH). The proportion (by mass) of crystalline PAEK in the PAEK is estimated by the ratio

(A) / (A + AH).

The term “melting temperature” is understood to denote the temperature at which an at least partially crystalline polymer passes into the viscous liquid state, as measured by differential scanning calorimetry (DSC) according to standard NF EN ISO 11 357-3 in using a heating rate of 20 ° C / min.

The term “glass transition temperature” is understood to denote the temperature at which an at least partially amorphous polymer changes from a rubbery state to a glassy state, or vice versa, as measured by differential scanning calorimetry (DSC) according to the standard. NF EN ISO 11 357-2 using a heating rate of 20 ° C / min.

Poly (aryletherketone)

According to the invention, the mixture comprises at least one poly (aryletherketone) (PAEK).

Poly (aryletherketones) (PAEK) contain the units of the following formulas:

(- Ar - X -) and (- Ari - Y -)

in which :

Ar and Ari each denote a divalent aromatic radical;

Ar and Ari can be chosen, preferably, from 1,3-phenylene, 1,4-phenylene, 4,4'-biphenylene, 1,4-naphthylene, 1,5-naphthylene and 2,6 -naphthylene, optionally substituted;

X denotes an electron-withdrawing group; it can be chosen, preferably, from the carbonyl group and the sulfonyl group,

Y denotes a group chosen from an oxygen atom, a sulfur atom, an alkylene group, such as -CH2- and isopropylidene.

In these X and Y units, at least 50%, preferably at least 70% and more particularly, at least 80% of the groups X are a carbonyl group, and at least 50%, preferably at least 70% and more particularly at least. minus 80% of the Y groups represent an oxygen atom. According to a mode of

preferred embodiment, 100% of the X groups denote a carbonyl group and 100% of the Y groups represent an oxygen atom.

More preferably, the poly (aryletherketone) (PAEK) can be chosen from:

- a poly-ether-ketone-ketone, also called PEKK, comprising units of formula IA, of formula IB and their mixture:

a poly-ether-ether-ketone, also called PEEK, comprising units of formula II:

Formula II

The sequences can be totally para (Formula II). In the same way, it is possible to introduce, partially or totally, meta linkages into these structures at the level of ethers and ketones according to the two examples of formulas III and IV below:

Formula

Or :

Formula IV

Or sequences in ortho according to formula V:

a poly-ether-ketone, also called PEK, comprising units of formula VI

Formula VI

In the same way, the sequence can be totally para but we can also introduce partially or totally meta chains (formulas VII and VIII):

Formula VIII

a poly-ether-ether-ketone-ketone, also called PEEKK, comprising units of formulas IX:

Formula IX

In the same way, we can introduce meta chains into these structures at the level of ethers and ketones.

a poly-ether-ether-ether-ketone, also called PEEEK, comprising units of formulas X:

Formula X

In the same way, we can introduce meta linkages in these structures at the level of ethers and ketones but also biphenol or diphenyl linkages according to formula XI (type D units in the next names, formula XI thus corresponds to the name PEDEK):

Formula XI

Other arrangements of the carbonyl group and the oxygen atom are also possible.

In all of the preceding formulas, the index n, when present, can take any values, in particular 1 to 100, preferably 1 to 50 and very particularly 1 to 10. Preferably, the index n is equal to 1. In all of the preceding formulas, the indices x and y, when present, can independently of one another take any values, in particular 1 to 100, preferably 1 to 50 and very particularly 1 to 10. Preferably, the index x and y are equal to 1.

Preferably, the PAEKs used in the invention are chosen from the group consisting of poly-ether-ketone (PEK), polyether-ether-ketone (PEEK), poly-ether-ether-ketone-ketone (PEEKK), poly- ether-ether-ketone-ketone (PEKK), poly-ether-ketone-ether-ketone-ketone (PEKEKK), poly-ether-ether-ketone-ether-ketone (PEEKEK), poly-ether-ether-ether-ketone (PEEEK), and poly-ether-diphenyl-ether-ketone (PEDEK), their mixtures and their copolymers with one another or with other members of the PAEK family. PEEK and PEKK as well as their mixtures are particularly preferred.

Advantageously, the change in the molecular mass of PAEK in the molten state can be limited by the addition of one or more additives, for example phosphates.

Preferably, the poly (aryletherketone) (PAEK) in the mixture according to the invention comprises at least one polyether-ketone-ketone (PEKK) which represents more than 50%, preferably more than 60%, in particular more than 70%, still preferred more than 80% and in particular more than 90% by mass of this component, limit included. The remaining 10 to 50% by mass can consist of other polymers belonging to the PAEK family.

Advantageously, the PEKK has a percentage by weight of terephthalic units relative to the sum of the terephthalic and isophthalic units of between 40 and 100% and preferably between 50 and 90%, and very particularly between 60 and 80%, limits included.

More preferably, the poly (aryletherketone) consists essentially of PEKK or PEEK.

The poly (aryletherketone) in the mixture according to the invention can be amorphous or semi-crystalline. The crystallinity of poly (aryletherketone) depends in particular on the structure of the polymer but can also be a function of its thermal history.

According to a preferred embodiment of the invention, the poly (aryletherketone) in the mixture according to the invention is amorphous. According to another preferred embodiment, it is semi-crystalline. In the latter case, the poly (aryletherketone) in the mixture according to the invention advantageously exhibits a crystallinity of up to 60%, preferably from 10 to 50%, even more preferred from 15 to 40% and particularly preferred from 20 to 30. %.

The mixture according to the invention preferably contains a poly (aryletherketone) having a viscosity, measured at 380 ° C. and 1 Hz, greater than 100 Pa-s, preferably greater than 200 Pa-s and very particularly greater than 300 Pa-s. s.

The melting point of the poly (aryletherketone) is preferably above 280 ° C, and most particularly above 300 ° C. The glass transition temperature of the poly (aryletherketone) is preferably between 100 and 250 ° C, preferably between 120 and 200 ° C, and most particularly between 140 and 180 ° C.

Such poly (aryletherketones) are commercially available, for example PEKK under the name Kepstan ® from the company Arkema, and PEEK under the name KetaSpire ® from the company Solvay, under the name VestaKeep ® from the company Evonik and PEEK Victrex ® from the company Victrex.

The mixture according to the invention preferably contains 50 to 98, preferably 60 to 96, more preferably 70 to 95% by weight of poly (aryletherketone).

Polysiloxane

The mixture according to the invention contains, in addition to the poly (aryletherketone), also a polysiloxane. Such polysiloxanes can be mono- or di-substituted with C1 to C12, preferably C1 to Ob, and most particularly C1 to C 4 alkyl groups , and / or phenyl groups. Preferably, the alkyl groups are methyl groups. The alkyl or phenyl groups of the polysiloxane can be substituted by one or more functional groups such as epoxy, alkoxy, in particular methoxy, amine, ketone, thioether, halogen, nitrile, nitro, sulfone, phosphoryl, imino or thioester. These functional groups can also be located at the end of the polysiloxane chain. Such functionalized polysiloxanes can be used for their reaction during mixing (reactive siloxanes).

Preferably, however, the polysiloxane does not contain functional groups. Furthermore, the alkyl or phenyl groups of the polysiloxane may be substituted with one or more carbocyclic, aryl, heteroaryl, alkyl, alkenyl, bicyclic or tricylic groups.

Preferably, the polysiloxane present in the mixture is a poly (dimethylsiloxane) (PDMS).

Preferably, the polysiloxane has a very high molecular weight. Thus, the polysiloxane can advantageously have a number average molecular weight ranging from 100,000 to 1,000,000, and preferably from 250,000 to 750,000.

Advantageously, it may be a polysiloxane belonging to the family of silicone pastes. These silicones, sold for example by the company Wacker, have the advantage of exhibiting great resistance to heat and to chemicals, such as poly (aryletherketones).

In order to mix well with the matrix, the polysiloxane preferably has a lower viscosity than that of the poly (aryletherketone). Preferably, the viscosity of the polysiloxane is less than 30%, preferably 20%, more preferably 15% and most preferably 10%, of the viscosity of the poly (aryletherketone). A polysiloxane having a viscosity, measured at 380 ° C. and 1 Hz, greater than 50, advantageously greater than 100 Pa-s, preferably greater than 200 Pa-s and very particularly greater than 300 Pa-s is particularly preferred.

It is preferred that the polysiloxane be inert under the conditions of preparation and use of the mixture of the invention. Thus, it is advantageous for the polysiloxane to resist the manufacture of the mixture and therefore the melting point of the poly (aryletherketone) matrix.

A mixture comprising 1 to 49, preferably 2 to 40, more preferably 2.5 to 25% by weight of polysiloxane is particularly preferred.

In order to facilitate handling, the polysiloxane can be combined with a solid support such as a silica, in particular pyrogenic silica. The mixture is then in the form of granules or powder. Such polysiloxane formulations comprise up to 55% by weight, preferably up to 40% by weight of carrier. The support can also be another type of filler or even a polymer powder, which can be of the same type as the matrix of the mixture. The indications of polysiloxane proportions given in the present application always refer to the polysiloxane content, after deduction of the support.

Such polysiloxanes are commercially available. Thus, the Wacker company sells ultra-high molecular weight polysiloxanes under the name Genioplast ® GUM and these same polysiloxanes on a silica support under the name Génioplast ® PELLET S.

Polysiloxane block copolymer

The mixture according to the invention also contains, in addition to the poly (aryletherketone), a block copolymer containing polysiloxane blocks.

The polysiloxane blocks can be mono- or di-substituted with C1 to C12, preferably C1 to Ob, and most particularly C1 to C 4 alkyl groups and / or phenyl groups. Preferably, the alkyl groups are methyl groups. Preferably, the polysiloxane units present in the block copolymer containing polysiloxane blocks are poly (dimethylsiloxane) (PDMS) units.

The alkyl or phenyl groups of the polysiloxane block may be substituted by one or more functional groups such as epoxy, alkoxy, in particular methoxy, amine, ketone, thioether, halogen, nitrile, nitro, sulfone, phosphoryl, imino or thioester. These functional groups can also be located at the end of the chain of the block copolymer containing polysiloxane blocks. Preferably, however, the polysiloxane block does not contain functional groups. Furthermore, the alkyl or phenyl groups of the polysiloxane block may be substituted with one or more carbocyclic, aryl, heteroaryl, alkyl, alkenyl, bicyclic or tricylic groups.

The block copolymer containing polysiloxane blocks furthermore comprises blocks of units different from the polysiloxanes. They may in particular be polyether-imide, poly (aryletherketone), poly (arylethersulfone), poly (phenylene sulfide), poly (arylamideimide), poly (phenylene), poly (benzimidazole) and / or polycarbonate blocks. Preferably, the block copolymer containing polysiloxane blocks further comprises blocks of poly (etherimide) or of poly (arylketonecetone).

It is particularly preferred that the block copolymer containing polysiloxane blocks comprises blocks of the poly (aryletherketone) constituting the matrix of the mixture according to the invention.

The block copolymer containing polysiloxane blocks preferably comprises a siloxane content of 10 to 70% by weight, advantageously of 15 to 60% by weight, even more preferably 20 to 50% by weight relative to the weight of the copolymer. Unlike the compositions described in US Pat. No. 8,013,251, the use of a block copolymer containing polysiloxane blocks with a high siloxane content does not lead to delamination during extrusion and molding in the mixtures according to the invention.

The block copolymer containing polysiloxane blocks preferably has a viscosity, measured at 380 ° C. and 1 Hz, greater than 100 Pa-s, preferably greater than 200 Pa-s and very particularly greater than 300 Pa-s. According to one embodiment, the block copolymer containing polysiloxane blocks has a viscosity, measured at 380 ° C. and 1 Hz, of between 300 and 500 Pa-s. According to another embodiment, the block copolymer containing polysiloxane blocks has a viscosity, measured at 380 ° C. and 1 Hz, of between 600 and 900 Pa-s.

A polymer blend comprising 1 to 49, preferably 2 to 40, more preferably 2.5 to 30% by weight of polysiloxane block block copolymer is particularly preferred.

Such polysiloxane block block copolymers are commercially available. Thus, the Sabic company sells PEI-PDMS block copolymers under the name Siltem ® . Moreover, the company Idemitsu Kosan sells a polycarbonate-PDMS copolymer under the name Tarflon ® Neo.

Other components

The mixture according to the invention can also comprise other polymers, in a smaller quantity. Thus, the content of additional polymers, different from those discussed above, in the mixture of the invention is preferably less than 20% by weight, more preferably less than 15% by weight and very particularly less than 10% by weight. Among the additional polymers, mention may in particular be made of polyetherimide.

The mixture according to the invention can moreover, as discussed above, additionally comprise customary additives such as fillers. Among the fillers that can be envisaged, mention may in particular be made of silica and alumina, nucleating fillers such as mineral fillers, in particular talc, carbonaceous fillers, in particular carbon nanotubes, carbon fibers or metal oxides, or reinforcing fillers such as glass fibers or carbon fibers.

Furthermore, the mixture may optionally comprise minor amounts of functional additives. There may be mentioned as such, for example, antistatic agents, antioxidants, stabilizers in the molten state, conductive agents, flame retardants, dyes as well as reactive agents such as alkali carbonates.

Advantageously, the mixture of polymers according to the invention comprises 0 to 30, preferably 1 to 20, more preferably 2 to 10% by weight of additives. Preferably, the mixture does not contain any additives other than the optional support for the polysiloxane. In particular, it is preferred that the mixture according to the invention does not contain conductive additives such as, for example, carbon black.

Method of manufacturing the mixture according to the invention

The polymeric mixture according to the invention can be obtained by any one of the processes known in the state of the art. In particular, it can be obtained by bringing the components into contact at a temperature above the melting point of the poly (aryletherketone). After cooling, it can then be granulated, if necessary.

An easy way to obtain the mixture according to the invention is to introduce the components in the desired proportions into a co-mixer or an extruder, in particular a twin-screw extruder, heated to a temperature exceeding the melting point of the poly (aryletherketone). . Depending on the mixing means chosen, the mixture according to the invention is obtained in the form of granules.

According to a preferred embodiment, the mixture according to the invention is in the form of a heterophasic composition. In fact, most often, the polysiloxane is little or not soluble in the poly (aryletherketone). A phase dispersed in the form of nodules in a continuous phase is then observed by electron microscopy. Preferably, the nodules have an average diameter of less than 20 μm, advantageously less than 10 μm and very particularly less than 5 μm.

Preferably, the poly (aryletherketone) forms the continuous phase (also called the matrix) of the composition and the polysiloxane forms the dispersed phase. The polysiloxane block copolymer is preferably essentially present in the dispersed phase.

Use of the mixtures according to the invention

The mixture according to the invention can then be used for the manufacture of parts by one of the conventional forming processes.

Thus, the mixture according to the invention can be shaped for example by molding, in particular by injection molding or by compression molding, by extrusion, by extrusion calendering, spinning, rotational molding, thermoforming, coating, additive manufacturing by filament melting. (FFF), by extrusion of films or sheets, by calendering extrusion, extrusion of tubes or pipes, sheathing extrusion, extrusion, rotational molding, thermoforming, coating, additive manufacturing by laser sintering, or by coating from powder. Particularly interesting is also the use of the mixture according to the invention for the production of composites.

For the last three forming processes, it is preferred to start with a powder obtained from said composition obtained by standard grinding processes. Particularly preferred is a powder having a volume median diameter (dv50) as measured according to the ISO 9276 standard - parts 1 to 6 of 10 to 400 μm. In the present description, a Malvern Mastersizer 2000 particle size analyzer is used and the measurement is made in a liquid way by laser diffraction on the powder.

Depending on the use envisaged, it may be advantageous to add to the powder of the mixture of the invention one or more fillers such as carbon fibers or glass fibers and / or other pulverulent additives and / or agents of 'flow.

The aforesaid transformation processes make it possible to obtain, from the polymer mixture according to the invention, powders, films or sheets, fibers, coatings, parts of various sizes and geometry, and composite parts.

The mixture according to the invention is particularly advantageous for the manufacture of parts exhibiting improved impact resistance, elongation at break and flexibility. This results in the possibility of manufacturing parts that are durable because they have lower crack propagation.

The increase in flexibility and elongation at break allow higher deformations and consequently access to new designs, particularly for assembly or winding. Thus, the mixture according to the invention is particularly advantageous for the manufacture of parts in the field of petroleum, cabling, aeronautics, automotive, electronics, electrical engineering, composites, additive manufacturing and devices. medical.

In the field of petroleum, mention may be made in particular of pipes working on land (“onshore” in English) or in the open sea (“offshore” in English), in particular sheaths or pipes (“liner” in English) for composites, umbilicals and pressure sheaths, systems embedded in wells ("downhole" in English) such as drill pipes and semi-products ("stock shape" in English). In cabling, mention may in particular be made of cable sheaths for insulation. In the field of aeronautics, mention may in particular be made of pipes, composite parts, connectors and supports. In the automotive field, mention may be made of all the engine or transmission environment parts exposed to high temperatures, such as, for example, turbo inlet and outlet or pipes conveying hot or aggressive liquids (oil circuit, cooling circuit, and fuel circuit). Finally, in medical and analytical devices, mention may be made of flexible pipes resistant to high temperatures and pressure.

In addition, the improved flexibility of the mixture allows to consider new designs for parts exposed to high temperature and high chemical resistance.

The invention will be explained in more detail in the examples which follow.

[Examples]

A. Preparation of PEKK mixtures

In a twin-screw extruder (Haake 2, diameter: 16 mm, screw speed: 340-360 rpm, flow rate: 3 kg / h), a poly (etherketoneketone) (PEKK) (KEPSTAN ® , sold by the company Arkema France) with a poly (etherimide) -poly (dimethylsiloxane) (PEI-PDMS) copolymer (sold by the company SABIC under the name Siltem ® STM 1500 and Siltem ® STM 1700) and a polydimethylsiloxane (PDMS) at molecular weight very high (Genioplast ® Gum, sold by the company Wacker) or a very high molecular weight polydimethylsiloxane (PDMS) on a silica support (Génioplast ®PELLET S, sold by the Wacker company, composition: 70% by weight of PDMS, 30% by weight of silica). By way of comparison, mixtures comprising, in addition to the poly (etherketonketone) only the PEI- copolymer, were prepared.

PDMS or just PDMS. The respective composition of the mixtures is shown in Table 1 below.

The temperature profile in the extruder is adapted to the melting temperature of the poly (etherketonketone) type KEPSTAN ® 6000, exhibiting a ratio of terephthalic units to isophthalic units of 60:40 and of type KEPSTAN ® 8000, exhibiting a ratio of 80:20 terephthalic units to isophthalic units as follows:

KEPSTAN ® 6000 type poly (etherketonecetone) : 200 ° C at the inlet then 330 ° C,

KEPSTAN ® 8000 type poly (etherketonecetone) : 220 ° C at the inlet then 380 ° C,

The compound obtained is granulated and then dried at 120 ° C. under vacuum for 24 h.

Table 1: Compositions of the polymer mixtures prepared

* at 380 ° C and at 1 Hz

+ Siltem ® STM 1500

Siltem ® STM 1700

B. Evaluation of impact and tensile strength

The mechanical properties and the impact resistance of the mixtures according to the invention were evaluated using IA tensile dumbbells according to the ISO 527-2 standard and 80 * 10 * 4 mm 3 impact bars according to the Choc Charpy ISO 179 standard. The specimens were prepared by injection on a Battenfeld press using the following parameters, depending on the type of PEKK used:

poly (etherketonecetone) of the KEPSTAN ® 6000 type : feed 330 ° C .; Nozzle: 345 ° C; 80 ° C mold

poly (etherketonecetone) type KEPSTAN ® 8000: feed 355 ° C; Nozzle: 380 ° C; Mold 230 ° C

The notched impact resistance type A was evaluated on an impact testing machine (Zwick 5102) according to the ISO 179 standard. The specimens were first notched (in V with a notch bottom radius of 0, 25 +/- 0.5 mm) on a device specially designed for this purpose (Automatic Notchvis Plus, marketed by the company Ceast) then left to stand for 24 hours (at 23 ° C and 50% relative humidity) in order to relax constraints. Each test was carried out on at least three test pieces. One evaluates the type of rupture of the test-tube according to the following definition:

C: Complete rupture. The test piece separates into two or more pieces.

H: Hinge break. The test piece breaks incompletely, the two parts of the test piece being joined only by a peripheral thin layer forming a hinge without residual rigidity.

P: Partial rupture. The specimen partially ruptures without meeting the definition of hinge failure above.

The tensile strength of the specimens was measured on a tensile testing machine (Zwick 1445) under the following conditions: temperature 23 ° C, 50% relative humidity. The Young's modulus was calculated with a mechanical extensometer between 0.05 and 0.25% strain at 1 mm / min, the remainder of the tensile test, until fracture, was carried out at 50 mm / min. One notes the number of test-tubes having broken before or after the strain at the threshold of plasticity. A test piece which has broken before this threshold is classified as brittle and a test piece which has broken after this threshold is classified as ductile. For example, the mention of “1D / 2F” corresponds to a specimen having broken after the threshold, and therefore classified as ductile, and two specimens having broken before the threshold, and therefore classified as fragile.

The results of the evaluations are collated in Table 2 below.

Table 2: Tensile and impact strength of mixtures

** D = ductile; F = fragile (before the deformation at the tensile point)

It is noted that the impact resistance of the mixtures according to the invention is markedly higher than that of the reference resins. In addition, it is noted that for a given PEKK, the impact resistance of the mixtures according to the invention is greater than that of the comparison mixtures devoid of a block copolymer with a polysiloxane block (Comp 1 and 2) or of polysiloxane (Comp 3 and 4 ), even when the modifier content is lower. It is noted that the mixtures according to Example 1 and 3 contain 10% by mass of PDMS (sum of the mass rates of PDMS and of PDMS units of the PEI-PDMS copolymer), ie the same amount of overall PDMS as the examples Comp 1 and Comp 2.

In particular, for Examples 1 and 2 (comprising an amorphous PEKK), a change in rupture mode is observed. In addition, it is noted that for a given PEKK, the impact resistance of the mixtures according to the invention is greater than that of the comparison mixtures devoid of a block copolymer with a polysiloxane block (Comp 1 and 2) or of polysiloxane (Comp 3 and 4 ), even when the modifier content is lower. These tests therefore demonstrate that the resilience of the ternary mixtures according to the invention is greater than that of the binary mixtures.

Regarding the tensile strength, it is observed that only the mixture according to the invention based on amorphous PEKK (example 1) exhibits a lower deformation than the reference resin (REF1), although nevertheless better than the binary mixture (Comp 1). The mixtures according to the invention based on semi-crystalline PEKK (Examples 3, 5 and 6) exhibit values ​​which are markedly higher than those of the reference resin (REF 2) and of the binary mixture (Comp 2). These tests therefore demonstrate that the tensile strength of the ternary mixtures according to the invention is greater than that of the binary mixtures studied.

We also evaluated a mixture with a polysiloxane combined with fumed silica (example 6), easier to use because in the form of granules. This mixture has an impact strength and an elongation at break greater than the matrix alone or the binary mixture. However, it does not reach the level of the equivalent mixture without silica (example 3). The results of the tests make it possible to conclude that the tensile strain of the mixtures according to the invention is greater than that of the binary mixtures studied.

We have also evaluated a blend with a lower polysiloxane content polysiloxane block copolymer (Syltem ® STM 1700). This copolymer also provides a gain in terms of impact resistance, compared to the pure matrix (REF 2) as compared to the binary mixture (Comp 2, 3 and 4).

The comparison of the properties of the mixtures differing only by the viscosity of the PEKK matrix (examples 1/2 and 3/4) furthermore reveals a substantial impact of the viscosity of the matrix.

C. Study of the morphology of mixtures

In order to study the morphology of the mixtures prepared, they were observed by scanning electron microscopy (SEM; model QUANTA FEG250 from FEI) in BSE mode, on facies surfaced by microtomy (diamond knife / room temperature), with a magnification X400 . The results are shown in Figs. 1 to 3.

It is observed that all the mixtures evaluated are heterophasic. For the mixture of Example 3 (see Fig.l), the dispersion is very fine, with a size of the dispersed phase of the order of 0.1 to 1.2 µm. For the mixture of Example 4 (see Fig. 2), which differs from Example 3 only by a higher viscosity poly (etherketonketone), it is found that the dispersed phase is of size

superior. The binary mixture according to Comparative Example 2 (see FIG. 3), devoid of block copolymer with polysiloxane blocks, exhibits a dispersed phase with a dimension of the dispersed phase which is markedly larger, of the order of 1 to 40 μm.

It is therefore observed that the presence of the block copolymer containing polysiloxane blocks favorably affects the microstructure of the mixture. It is assumed that this result is linked in particular to a better dispersion of the polysiloxane. Without wishing to be bound by this assumption, it is believed that the polysiloxane block copolymer allows the formation of smaller sized nodules by acting as a surfactant.

D. Evaluation of fire resistance

In order to check whether the mixtures retain the advantageous properties of the poly (aryletherketone) matrix, fire resistance tests were carried out as follows.

The useful sections (4 * 10 mm 2 ) of ISO 527 IA tensile test specimens prepared as indicated above were subjected to tests of the Limited Oxygen Index type (LOI, "limited Oxygen Index") on specimen of the type I in accordance with ISO 4589 under the following conditions. The test pieces were placed in an atmosphere composed of a mixture of oxygen and nitrogen, the oxygen concentration of this mixture being increased in steps of 1% until at least one of the two conditions below is fulfilled:

the combustion time Te exceeds 3 minutes,

combustion proceeds up to 50 mm below the top of the specimen.

The tests were carried out on two specimens, respectively. The results are collated in Table 3 below.

Table 3: Results of the fire resistance tests

It is observed that the fire resistance properties of the poly (aryletherketone) matrix are preserved in the mixture according to the invention, and even slightly improved.

All the results show that the poly (aryletherketone) blends according to the invention make it possible to improve the resilience and tensile deformation compared to poly (aryletherketone) alone and to binary blends, comprising either the block block copolymer polysiloxane, or a polysiloxane. The study of the morphology of these mixtures reveals a favorable effect of the block copolymer with polysiloxane blocks on the dispersion of the polysiloxane in the poly (aryletherketone). Finally, it was verified that the fire resistance properties of poly (aryletherketone) are preserved in the mixtures according to the invention.

[List of documents cited]

US 2009/0292073 Al

US 2005/0004326 Al

US 8,013,251 B2

US 2017/0242372 Al

CLAIMS

1. Mixture of polymers, comprising:

(i) a poly (aryletherketone);

(ii) a polysiloxane; and

(iii) a block copolymer containing polysiloxane blocks.

2. Polymer mixture according to claim 1, in which the poly (aryletherketone) has a viscosity, as measured at 380 ° C and 1 Hz, greater than 100 Pa-s, preferably greater than 200 Pa-s and very particularly greater than 300 Pa-s.

3. Polymer mixture according to one of claims 1 to 2, wherein the poly (aryletherketone) is selected from the group consisting of poly-ether-ketone (PEK), polyether-ether-ketone (PEEK), poly-ether. -ether-ketone-ketone (PEEKK), poly-ether- ether-ketone-ketone (PEKK), poly-ether-ketone-ether-ketone-ketone (PEKEKK), poly- ether-ether-ketone-ether-ketone ( PEEKEK), poly-ether-ether-ether-ketone (PEEEK), and poly-ether-diphenyl-ether-ketone (PEDEK), their mixtures and their copolymers with each other or with other members of the poly (aryletherketone family) ).

4. Polymer mixture according to one of claims 1 to 3, comprising 50 to 98, preferably 60 to 96, more preferably 70 to 95% by weight of poly (aryletherketone).

5. Polymer mixture according to one of claims 1 to 4, wherein the poly (aryletherketone) is a poly (etherketonketone) (PEKK), a poly (etheretherketone) (PEEK) or a mixture thereof.

6. Mixture of polymers according to one of claims 1 to 5, wherein the PEKK has a percentage by weight of terephthalic units relative to the sum of the terephthalic and isophthalic units of between 50 and 90%.

7. Polymer mixture according to one of claims 1 to 6, wherein the polysiloxane has a viscosity, as measured at 380 ° C and 1 Hz, greater than 100 Pa-s, preferably greater than 200 Pa-s and very particularly greater than 300 Pa-s.

8. Polymer mixture according to one of claims 1 to 7, comprising 1 to 49, preferably 2 to 40, more preferably 2.5 to 25% by weight of polysiloxane.

9. Polymer mixture according to one of claims 1 to 8, wherein the block copolymer with polysiloxane blocks has a viscosity, as measured at 380 ° C and 1 Hz, greater than 100 Pa-s, preferably greater than 200 Pa-s and especially greater than 300 Pa-s.

10. Polymer mixture according to one of claims 1 to 9, comprising 1 to 49, preferably 2 to 40, more preferably 2.5 to 30% by weight of block copolymer containing polysiloxane blocks.

11. Mixture of polymers, according to one of claims 1 to 10, wherein the block copolymer with polysiloxane blocks further comprises blocks chosen from poly (etherimide), poly (aryletherketone), poly (arylethersulfone), poly (phenylene sulfide), poly (arylamideimide), poly (phenylene), poly (benzimidazole), or polycarbonate.

12. A process for preparing a mixture of polymers according to claim 1 to 11, comprising the steps of:

at. contacting a poly (aryletherketone), a polysiloxane and a polysiloxane block block copolymer under conditions where the poly (aryletherketone) melts; and

b. let the said mixture cool to obtain the mixture.

13. The method of claim 12, wherein step (a) is carried out in a twin-screw extruder or a co-kneader.

14. Use of a mixture of polymers according to one of claims 1 or 11 for the manufacture of parts, in particular by molding, in particular by injection molding or by compression molding, by additive manufacturing by filament fusion (FFF), extrusion of films or sheets, calendering extrusion, extrusion of tubes or pipes, sheathing extrusion, spinning, rotational molding, thermoforming, coating, additive manufacturing by laser sintering, coating from powder or for the production of composites.

15. Part, manufactured at least partially from the mixture of polymers according to one of claims 1 to 11.