Polyaryletherketone-based composition

Abstract

The invention relates to a composition C based on at least one semicrystalline or pseudoamorphous polyaryletherketone comprising 0.2% to 1.2% by weight of a nucleating filler relative to the total weight of polyaryletherketone and as a nucleating filler, said nucleating filler being selected from a silicate, a carbon material having a BET specific surface area greater than or equal to 200 g / m2, or a mixture thereof.

Description

[0001] Description

[0002] Title: Composition based on polyaryletherketone(s)

[0003] Technical field

[0004] The invention relates to the field of polymer compositions based on polyaryletherketone(s) having improved elongation at break. It also relates to methods for manufacturing objects.

[0005] Prior art

[0006] Polyaryl ether ketones (PAEKs) are well-known high-performance engineering polymers. They can be used for applications requiring high temperatures and / or mechanical or even chemical stresses. They can also be used for applications requiring excellent fire resistance and low smoke or toxic gas emissions. They can also be used for their low gas permeability. Finally, they exhibit good biocompatibility.

[0007] These polymers are found in fields as varied as aeronautics and space, offshore drilling, automotive, railways, marine, wind power, sports, construction, electronics and even medical implants.

[0008] It is known that processing processes influence the microstructure of polymers. In the case of poly-aryl-ether-ketones, and in particular poly-ether-ketone-ketones (PEKK), the inventors of the present invention started from the observation that thick object extrusion processes led to fragile objects. As expected, these processes involve very long cooling times, which induces high crystallinity rates and / or large spherulites in the manufactured objects. This generally has unfavorable consequences in terms of ductility.

[0009] There remains a need to develop composition formulations based on poly-aryl-ether-ketone(s) for their use in such processes, making it possible to improve the ductility of the manufactured objects. Objective of the invention

[0010] The objective of the invention is to propose compositions based on additive poly-aryl-ether-ketone(s) making it possible to increase (in comparison with the same non-additive composition) the ductility of objects manufactured using standard methods for manufacturing objects, in particular thick objects.

[0011] According to certain embodiments, another objective of the invention is to provide compositions based on additivated poly-aryl-ether-ketone(s) making it possible to preserve the other properties of the manufactured objects, such as for example a high crystallinity rate.

[0012] Another objective of the invention is to propose methods for manufacturing objects, for which these compositions are particularly suitable.

[0013] Summary of the invention

[0014] The invention relates to a composition C based on at least one semi-crystalline or pseudo-amorphous polyaryletherketone comprising from 0.2% to 1.2% by weight of a nucleating charge, relative to the total weight of polyaryletherketone and nucleating charge, said nucleating charge being chosen from a silicate, a carbon material having a BET specific surface area greater than or equal to 200 g / m 2 , or their mixture.

[0015] According to certain embodiments, the nucleating charge represents from 0.25 to 1.0% by weight, relative to the total weight of polyaryletherketone(s) and nucleating charge.

[0016] In some embodiments, the nucleating charge represents 0.5% or more by weight, relative to the total weight of polyaryletherketone(s) and nucleating charge.

[0017] In some embodiments, the nucleating charge is 0.9% or less by weight, or 0.8% or less by weight, or 0.75% or less by weight, relative to the total weight of polyaryletherketone(s) and nucleating charge.

[0018] In some embodiments, the polyaryletherketone is a semi-crystalline polyaryletherketone.

[0019] In some embodiments, the polyaryletherketone is a polyetherketoneketone. In some embodiments, the polyaryletherketone is a polyetherketoneketone, consisting essentially of, or consisting of, a terephthalic repeating unit and, where appropriate, an isophthalic repeating unit, the terephthalic repeating unit having the formula: said polyetherketoneketone having a mass proportion of units of formula (I) relative to the totality of the units of formula (I) and formula (II) ranging from 55% to 100%, preferably from 65% to 95%, more preferably from 70% to 90%, and more preferably from 72% to 85%.

[0020] According to certain embodiments, the polyaryletherketone forms a matrix incorporating said nucleating charge. As such, the composition may be in the form of granules of composition C.

[0021] In some embodiments, the nucleating charge is a carbon material selected from the list consisting of carbon black, carbon nanotubes, graphene, or a mixture thereof.

[0022] In some embodiments, the nucleating charge is a carbonaceous material having a BET specific surface area greater than or equal to 300 g / m 2 , preferably having a BET specific surface area greater than or equal to 400 g / m2 , and more preferably having a BET specific surface area greater than or equal to 500 g / m 2 .

[0023] According to some embodiments, the nucleating filler is a talc.

[0024] In some embodiments, the nucleating charge has a particle size distribution, measured by gravity sedimentation in a liquid according to ISO 13317-3:2001, such that the median diameter d50 is such that d50 < 4 pm, and preferably such that d50 < 2 pm. In some embodiments, the nucleating charge has a particle size distribution, measured by gravity sedimentation in a liquid according to ISO 13317-3:2001, such that the median diameter d50 is such that d50 < 1.5 pm.

[0025] According to some embodiments, the nucleating charge has a particle size distribution measured by gravity sedimentation in a liquid according to ISO 13317-3:2001, such that d95 < 8 pm, and preferably such that d95 < 4 pm.

[0026] The invention also relates to a method for manufacturing a part, an article or a coating of composition C comprising: providing the constituent elements of a composition C according to the invention; a heating step so as to obtain the composition C in the molten state; a cooling step of the composition C, from the molten state to a solid state, so as to obtain a part, an article, or a solidified coating; and, optionally, a step of annealing the part, the article, or the solidified coating;wherein all or part of composition C is, during the cooling step and the annealing step, in the embodiments where an annealing step is carried out, at a temperature in the temperature range between the glass transition temperature of the polyaryletherketone, denoted Tg, and the melting temperature of the polyaryletherketone, denoted Tf, preferably in the temperature range from Tg+10°C to Tf-10°C, for a duration at least 2 times greater, or at least 5 times greater, or at least 10 times greater, or at least 25 times greater, or at least 100 times greater than its minimum isothermal half-crystallization time.;

[0027] According to certain embodiments, said method is chosen from the following methods: molding, in particular injection molding or compression molding, additive manufacturing by filament fusion (FFF), extrusion of films of sheets, or plates, calendering extrusion, extrusion of tubes, pipes or bars, extrusion sheathing, extrusion-compression, injection-compression, spinning, rotational molding, thermoforming, and coating.

[0028] Preferably, said process is chosen from the following processes: extrusion of sheets or plates, extrusion of bars and extrusion-compression.

[0029] The invention also relates to an object (part, article or coating) obtained by any of the methods cited above, having a thickness greater than 1 mm, or greater than 2 mm, or greater than 3 mm, or greater than 4 mm, or greater than 5 mm, or greater than 6 mm. Advantageously, the object has spherulites of average size strictly less than 4 micrometers. Advantageously again, the object has an elongation at break greater than the elongation at the threshold in at least 30% of cases.

[0030] Detailed description of the invention

[0031] Definitions

[0032] The term "thermoplastic polymer" refers to a polymer that becomes less viscous, or more liquid, or liquid when heated sufficiently and that reversibly retains its thermoplasticity. Thermoplastic polymers are generally contrasted with thermosetting polymers, which irreversibly transform into an insoluble, non-formable polymer network when heated.

[0033] The term "homopolymer" is understood to mean a polymer consisting of a single repeating unit.

[0034] The term "copolymer" refers to a polymer resulting from the copolymerization of at least two types of chemically different monomers, called comonomers. A copolymer is therefore formed from at least two repeating units derived from different monomers. It can also be formed from three or more repeating units derived from different monomers.

[0035] The copolymer may have a homogeneous structure, in particular of the statistical, alternating or random type, or a heterogeneous structure, in particular of the sequenced or block type.

[0036] “Consisting essentially of unit(s)” means that the unit(s) represent(s) a molar proportion of 95% to 99.9% of the total number of moles of repeating units in the polymer.

[0037] “Consisting of unit(s)” means that the unit(s) represent(s) a molar proportion of at least 99.9%, in particular 100%, in the polymer relative to the total number of moles of repeating units in the polymer.

[0038] "Powder" means a fractionated state of matter, generally in the form of very small particles, generally of the order of a hundred micrometers or less. "Powdery" means a state of matter which is in its entirety in the form of a powder.

[0039] The term "granule" refers to grains of composition, more or less cylindrical or spherical in shape, particularly suitable for extrusion or injection processes. These grains generally have a characteristic size of between 0.5 mm and 10 mm, particularly between 1 mm and 5 mm.

[0040] The term "glass transition temperature", denoted T, is understood to mean g, designate the temperature at which an at least partially amorphous polymer passes from a rubbery state to a glassy state, or vice versa, as measured by differential scanning calorimetry (DSC) according to standard NF ISO 11357-2: 2020, in second heating, using temperature ramps in heating and cooling at 20°C / min. In the present invention, when reference is made to a glass transition temperature, it is more particularly, unless otherwise indicated, the glass transition temperature at half-step height as defined in this standard. The term "melting temperature", noted Tf, is understood to designate the temperature at which a semi-crystalline polymer passes to the viscous liquid state, as measured by differential scanning calorimetry (DSC) according to standard NF EN ISO 11357-3: 2018, in second heating, using a heating rate of 20°C / min.In the present invention, when reference is made to a melting temperature, it is more particularly, unless otherwise indicated (see in particular the adapted measurement method below for a pseudo-amorphous polymer), the peak melting temperature as defined in this standard.

[0041] The term “pseudo-amorphous” polymer is understood to mean a polymer that does not exhibit a melting endotherm, as measured by differential scanning calorimetry (DSC) according to standard NF EN ISO 11357-3:2018, in the second heating, using heating and cooling rates of 20°C / min. The pseudo-amorphous polymer is nevertheless capable of crystallizing once brought to a temperature above its glass transition temperature, in particular to a temperature in the range Tg+40°C to Tg+110°C, for example at Tg+75°C, for a sufficient time, in particular for 10 to 30 minutes, for example 20 minutes. Thus, a melting temperature in the second heating for the pseudoamorphous polymers in the present invention can also be measured, by proceeding as follows:

[0042] 1 èreheating according to a ramp of 20°C / min up to a plateau temperature in the range Tg+40°C to Tg+110°C, for example at Tg+75°C, for a sufficient time, in particular for 10 to 30 minutes, for example 20 minutes, in particular at Tg+75°C for 20 minutes;

[0043] Cooling at a 20°C / min ramp to room temperature;

[0044] 2 ème heating according to a ramp at 20°C / min.

[0045] The term “crystallinity rate” means the crystallinity rate as calculated from wide angle X-ray scattering (WAXS) measurements, on a Nano-inXider® type device with the following conditions:

[0046] Wavelength: main Ka1 line of copper (1.54 Angstrom); Generator power: 50 kV - 0.6 mA;

[0047] Observation mode: transmission;

[0048] Counting time: 10 minutes;

[0049] Temperature: 25°C;

[0050] A spectrum of the scattered intensity is thus obtained as a function of the diffraction angle. 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, the area of ​​the crystalline peaks (denoted A) and the area of ​​the amorphous halo (denoted AH) can be measured. The proportion (by mass) in the crystalline phase is estimated by the ratio (A) / (A+AH). The crystallinity rates in the present invention are expressed as the mass proportion of crystalline poly-aryl-ether-ketone(s), relative to the total weight of poly-aryl-ether-ketone(s).

[0051] The term "isothermal half-crystallization time" means the time required to reach a relative crystallinity of 0.5 for isothermal crystallization at a measurement temperature, as defined in NF EN ISO 11357-7:2015. The minimum isothermal half-crystallization time corresponds to the minimum half-crystallization time for half-crystallization times measured between the glass transition temperature of a polymer and its melting temperature. Isothermal half-crystallization time values ​​as a function of temperature are generally available in the literature, which makes it possible to evaluate the minimum half-crystallization time. In the absence of available data, isothermal half-crystallization time measurements can be implemented with a step between each measurement of 5°C to 15°C.

[0052] The term "viscosity" means viscosity, as measured at 380°C and 1 Hz under an inert atmosphere (N2), using an oscillatory rheometer, in plane / plane geometry.

[0053] The tensile mechanical properties can be determined on type 1 BA specimens according to ISO 527-1:2019, at 23°C, with a crosshead speed of 25 mm / min, using for example an MTS 810® device, marketed by MTS Systems Corporation, equipped with a mechanical extensometer. A 1 BA specimen can be obtained directly by the manufacturing process for which the composition according to the invention is suitable or, where appropriate, machined from a solid object if the specimen cannot be obtained directly by this process.

[0054] The term "brittle material" is understood to mean that a material breaks at low deformations without exhibiting a yield point when determining its tensile properties (an example of such a material is shown in Figure 1, curve 1 of ISO 524-1:2019). Conversely, "ductile material" is understood to mean that a material breaks at higher deformations and exhibits a yield point when determining its tensile properties (examples of such materials are shown in Figure 1, curves 2-3 of ISO 524-1:2019).

[0055] The term "spherulite" or "spherolite" refers to an aggregated formation of needle-like crystals with a radiating structure, known as a fibroradiated structure. Some polymers, including polyaryl ether ketones, exhibit this type of crystal organization when they crystallize. Spherulites can be observed under a transmission electron microscope (TEM) on sections of approximately 40 nm obtained by ultracryomicrotomy at -100°C. The size of a spherulite corresponds to the diameter of the smallest circle capable of encompassing a spherulite thus observed. It is expressed in micrometers. The average size of spherulites corresponds to the average size observed on approximately 20 spherulites.

[0056] The term "d50" is taken to mean the value of the diameter of the nucleating charge particles so that the cumulative distribution function of the spherical equivalent Stokes diameters is equal to 50%. The diameter d50 is measured by gravity sedimentation in a liquid according to ISO 13317-3:2001, for example in a Sedigraph III Plus® device. ISO 9276 is used for mathematical and statistical modeling to calculate the particle size distribution.

[0057] The singular forms "a" and "the" applied to composition constituents, such as polyaryletherketone or the nucleating charge, mean by default "at least one" and respectively "said at least one". The singular forms nevertheless include, without it being necessary to recall it each time, the embodiments where "a" means "a single one" and "the" means "the only one".

[0058] The writing "polyaryletherketone(s)", or "poly-aryl-ether-ketone(s), or their acronym PAEK(s) must be interpreted as meaning one or more polyaryletherketones.

[0059] In all value ranges stated in this application, the terminals are included unless otherwise stated.

[0060] Polyaryletherketone

[0061] A polyaryletherketone (PAEK) has the following formula units: (-Ar-X-) and (-An-Y-), in which:

[0062] - Ar and An each designate a divalent aromatic radical;

[0063] - Ar and An may preferably be chosen from 1,3-phenylene, 1,4-phenylene, 1,1'-biphenylene divalent in positions 3,3', 1,1'-biphenyl divalent in positions 3,4', 1,4-naphthylene, 1,5-naphthylene and 2,6-naphthylene;

[0064] - X denotes an electron-withdrawing group; it may preferably be chosen from the carbonyl group and the sulfonyl group;

[0065] - Y denotes a group selected from an oxygen atom, a sulfur atom, an alkylene group, such as -(CH)2- and isopropylidene.

[0066] In these X and Y units, at least 50%, preferably at least 70% and more particularly at least 80% of the X groups are a carbonyl group, and at least 50%, preferably at least 70% and more particularly at least 80% of the Y groups represent an oxygen atom.

[0067] According to a preferred embodiment, 100% of the X groups denote a carbonyl group and 100% of the Y groups represent an oxygen atom.

[0068] Advantageously, the PAEK(s) may be chosen from: - a polyether-ketone-ketone, also called PEKK; a PEKK comprises one or more units of formula: -Ph-O-Ph-C(O)-Ph-C(O)-;

[0069] - a polyether-ether-ketone, also called PEEK; a PEEK comprises one or more units of formula: -Ph-O-Ph-O-Ph-C(O)-;

[0070] - a polyether ketone, also called PEK; a PEK comprises one or more units of formula: -Ph-O-Ph-C(O)-;

[0071] - a polyether-ether-ketone-ketone, also called PEEKK; a PEEKK comprises one or more units of formula: -Ph-O-Ph-O-Ph-C(O)- Ph-C(O)-;

[0072] - a polyether-ether-ether-ketone, also called PEEEK; a PEEEK comprises one or more units of formula: -Ph-O-Ph-O-Ph-O- Ph-C(O)-;

[0073] - a poly-ether-diphenyl-ether-ketone also called PEDEK; a PEDEK comprises one or more units of formula: a PEDEK comprises one or more units of formula -Ph-O-Ph-Ph-O-Ph-C(O)-;

[0074] - their mixtures; and,

[0075] - copolymers comprising at least two of the aforementioned units, in which: Ph represents a phenylene group and -C(O)- a carbonyl group, each of the phenylenes being able independently to be of the ortho (1-2), meta (1-3) or para (1-4) type, preferentially being of the meta or para type.

[0076] Additionally, defects, end groups and / or monomers may be incorporated in very small amounts into the polymers as described in the list above without affecting their performance.

[0077] According to certain embodiments, the poly-aryl-ether-ketone is semi-crystalline, that is to say that it exhibits a melting endotherm by DSC in second heating, using a heating rate of 20°C / min, or in other words that it exhibits sufficient crystallization kinetics so as to exhibit a melting endotherm under these measurement conditions.

[0078] According to certain embodiments, the PAEK is a polyether ketone ketone (PEKK) consisting essentially of, and preferably consisting of: a terephthalic repeating unit and, where appropriate, an isophthalic repeating unit, the terephthalic repeating unit (“T unit”) having the formula:

[0079]

[0080] The mass proportion of T units relative to the sum of T and I units can vary from 0% to 100%.

[0081] The choice of the molar proportion of T units relative to the sum of T and I units is one of the factors that allows adjustment of the melting temperature as well as the crystallization rate properties of polyether-ketone-ketones. A given molar proportion of T units relative to the sum of T and I units can be obtained by adjusting the respective concentrations of the reactants during polymerization, in a manner known per se.

[0082] Preferably, the polyether-ketone-ketone has a homogeneous structure, and can in particular be of the statistical type.

[0083] Advantageously, the polyetherketoneketone is chosen from polyetherketoneketones having a mass proportion of T units relative to the sum of the T and I units of 55% to 100%. Preferably, the mass proportion of T units relative to the sum of the T and I units is 65% to 95%, more preferably 70% to 90%, and more preferably 72% to 85%. The mass proportion of T units relative to the sum of the T and I units may in particular be 72% to 78%, or 78% to 82%, i.e. approximately 80%, or 82% to 85%.

[0084] Such polyetherketoneketones are commercially available under the name Kepstan® from Arkema.

[0085] According to certain embodiments, PAEK is a polyether-ether-ketone (PEEK) consisting essentially of, and preferably consisting of, the repeating unit (III), the unit (III) having the chemical formula:

[0086] Such polyetheretherketones are commercially available under the name KetaSpire® from Solvay, under the name VestaKeep® from Evonik and PEEK Victrex® from Victrex.

[0087] Advantageously, the poly-aryl-ether-ketone has a viscosity, measured at 380°C and 1 Hz, greater than 100 Pa s, preferably greater than 500 Pa s and more preferably greater than 800 Pa s. The viscosity of the poly-aryl-ether-ketone is generally not greater than 6000 Pa.s. The viscosity of the polyaryl-ether-ketone may in particular be from 800 Pa s to 1500 Pa s, or from 1500 Pa s to 2500 Pa s, or from 2500 Pa s to 5000 Pa s, or from 5000 Pa.s to 6000 Pa.s.

[0088] According to certain embodiments, the viscosity of the poly-aryl-ether-ketone is from 100 Pa.s to 6000 Pa.s, preferably from 500 to 5000 Pa.s, and more preferably from 800 to 2500 Pa.s.

[0089] According to certain embodiments, composition C comprises at least two PAEKs of different chemical composition, more particularly:

[0090] - a PEKK, in particular being essentially constituted, or constituted of the T and I motifs, as described above, and in addition to this PEKK,

[0091] - at least one of the following polymers: PEK, PEEKEK, PEEK, PEEKK, PEKEKK, PEEEK, PEDEK, PEKK representing at least 50% by weight of the total weight of poly-aryl-ether-ketones.

[0092] According to certain embodiments, composition C comprises a mixture of at least two PAEKs, these PAEKs being copolymers of PAEK having the same repeating units, but with different molar proportions of repeating units. In particular, composition C may comprise a mixture of two copolymers of PEKKs each having a different molar ratio of “T-type” units relative to the sum of the “T-type” and “I-type” units.

[0093] According to certain particular embodiments, composition C may also comprise a mixture of at least two PAEKs, these PAEKs having the same chemical formula, but different viscosity.

[0094] According to certain embodiments, composition C comprises a single PAEK. According to particular embodiments, this PAEK may be a PEKK. Nucleating charge

[0095] The nucleating filler is chosen from a silicate, a carbon material, or a mixture thereof. A proportion of 0.2% to 1.2% by weight of nucleating filler, relative to the total weight of poly-aryl-ether-ketone(s) and nucleating filler, has proven to be optimal for enabling the reduction of the size of spherulites during the construction of objects, by making it possible to improve their ductility, without modifying other properties targeted for the application (including the crystallinity rate).

[0096] The nucleating charge is usually in the form of a powder.

[0097] Preferably, the nucleating charge represents from 0.25% to 1.0% by weight, relative to the total weight of poly-aryl-ether-ketone(s) and nucleating charge. According to certain embodiments, the nucleating charge represents 0.5% or more by weight, relative to the total weight of poly-aryl-ether-ketone(s) and nucleating charge.

[0098] In some embodiments, the nucleating filler is 0.9% or less by weight, or 0.8% or less by weight, or 0.75% or less by weight, relative to the total weight of poly-aryl-ether-ketone(s) and nucleating filler.

[0099] A silicate is a mineral containing in its structure one or more anions of chemical formula: SiCM-x (4 ' 2X)_ , where 0 < x < 2. The counterion(s) may, among other things, be predominantly aluminum, potassium, magnesium, sodium, calcium, iron, or a mixture of these elements. The silicate may be present in hydroxylated form.

[0100] The nucleating charge can in particular be chosen from: talc, mica, kaolin, or their mixture.

[0101] According to particular embodiments, the nucleating charge is a talc.

[0102] The nucleating charge, particularly when it is a silicate, advantageously has a particle size distribution, measured by gravity sedimentation in a liquid according to ISO 13317-3:2001, such that the median diameter d50 is such that d50 < 4 pm, and preferably such that d50 < 2 pm.

[0103] According to certain preferred embodiments, d50 < 1.5 pm. In particular, d50 < 1.4 pm, or d50 < 1.3 pm, or d50 < 1.2 pm, or d50 < 1.1 pm, or d50 < 1.0 pm, or d50 < 0.9 pm can be had.

[0104] Furthermore, according to certain embodiments, one can have: (d95-d50) / d50 < 5, and preferably (d95-d50) / d50 < 3.

[0105] In embodiments where the nucleating charge is a carbon material, it may in particular be chosen from carbon black, graphene, carbon nanotubes, or a mixture thereof.

[0106] The BET specific surface area of ​​the nucleating charge being a carbon material is greater than or equal to 200 g / m 2 It can advantageously be greater than or equal to 500 g / m 2 , or greater than or equal to 600 g / m 2 , or greater than or equal to 700 g / m 2 , or greater than or equal to 800 g / m 2 , or greater than or equal to 900 g / m 2 , or greater than or equal to 1000 g / m 2 .

[0107] Preferably the BET specific surface area of ​​the nucleating charge being a carbon material is greater than or equal to 400 g / m 2 , and more preferably is greater than or equal to 500 g / m 2

[0108] Other polymers than PAEK(s) in composition C

[0109] According to certain embodiments, composition C may further comprise one or more other polymers not belonging to the PAEK family. Composition C may in particular comprise other thermoplastic polymer(s).

[0110] According to certain embodiments, composition C comprises, in addition to PAEK(s), at least one fluoropolymer, such as the fluoropolymers described in application EP 2,767,986 and US 9,543,058. The fluoropolymer may preferably be chosen from the list consisting of: a polytetrafluoroethylene (PTFE), a poly(vinyl fluoride) (PVF), a poly(vinyl fluoride) (PVDF), a polychlorotrifluoroethylene (PCTFE), a perfluoroalkoxy polymer, a perfluoroalkoxy-alkane copolymer (PFA), a fluorinated ethylene-propylene copolymer (FEP), a poly(ethylene-co-tetrafluoroethylene) (ETFE), polyethylenechlorotrifluoroethylene (ECTFE), a perfluorinated elastomer (FFKM), a perfluoropolyether (PFPE), and a mixture thereof.

[0111] Since fluoropolymers are generally immiscible with PAEKs, composition C is, in these embodiments, advantageously a dispersion of fluoropolymer particles in said at least one PAEK.

[0112] According to certain embodiments, composition C comprises, in addition to PAEK(s), at least one thermoplastic polymer chosen from: a polyetherimide (PEI), a silicone-polyimide copolymer or a polysiloxane / polyimide block copolymer (such as a polyetherimide / polydimethylsiloxane (PEI / PDMS)), such as the polymers described in applications EP 0 323 142 and US 8 013 251.

[0113] According to certain embodiments, composition C may comprise alternatively to the aforementioned thermoplastics or in addition to these: a polyphenylene sulfone (PPSU), a polysulfone (PSU), a polycarbonate (PC), a polyphenylene ether (PPE), a poly(phenylene sulfide) (PPS), a poly(ethylene terephthalate) (PET), a polyamide (PA), a polybenzimidizole (PBI), a poly(amide-imide) (PAI), a poly(ether sulfone) (PES), a poly(aryl sulfone), a poly(ether imide sulfone), a polyphenylene, a polybenzoxazole, a polybenzothiazole, or a mixture thereof.

[0114] Other additives than the nucleating charge in composition C

[0115] According to certain embodiments, composition C may comprise one or more additives other than the nucleating charge. These other additives generally represent less than 5% by weight, relative to the total weight of composition C. Preferably, the additives represent less than 1% by weight, relative to the total weight of composition C. Among the additives, mention may be made of stabilizers (to light, in particular UV, thermal), optical brighteners, dyes, pigments and energy-absorbing additives (including UV absorbers). According to certain embodiments, composition C may comprise one or more phosphates. The phosphate may in particular be a phosphate salt, such as a salt of H2PO4, HPO4 2 ; PO4 3; or a mixture thereof, preferably having a sodium ion, a potassium ion or a calcium ion, and more preferably a sodium ion, as counterion. Advantageously, the phosphate is incorporated into the PAEK(s) in a proportion greater than or equal to 500 ppm, or greater than or equal to 750 ppm, or greater than or equal to 1000 ppm, or greater than or equal to 1500 ppm, or greater than or equal to 2000 ppm, or greater than or equal to 2500 ppm, relative to the total weight of PAEK(s).

[0116] According to certain embodiments, composition C may in particular consist of: 55% to 100% by weight of polyaryletherketone(s) and nucleating charge;

[0117] 0% to 40% by weight of another thermoplastic polymer,

[0118] 0% to 5% by weight of another additive, relative to the total weight of the composition.

[0119] According to certain embodiments, composition C may in particular consist of:

[0120] 65% to 95% by weight of polyaryletherketone(s) and nucleating filler; 5% to 30% by weight of another thermoplastic polymer, 0% to 5% by weight of another additive, relative to the total weight of the composition.

[0121] According to certain embodiments, the polyaryletherketone(s) and the nucleating charge represent at least 65% by weight, or at least 75% by weight, or at least 85% by weight, or at least 90% by weight, or at least 95% by weight, or at least 97.5% by weight, or at least 99% by weight, relative to the total weight of the composition.

[0122] According to certain embodiments, composition C may in particular consist of:

[0123] 95% to 100% by weight of polyaryletherketone(s) and nucleating charge;

[0124] 0% to 5% by weight of another additive, relative to the total weight of the composition.

[0125] According to certain embodiments, composition C may consist of polyaryletherketone(s) and nucleating charge.

[0126] Making objects

[0127] The invention also relates to a method for manufacturing an object (part, article or coating) comprising: providing the constituent elements of a composition C according to the invention; a heating step so as to obtain the composition C in the molten state; a step of cooling the composition C, from the molten state to a solid state, so as to obtain a part, an article, or a solidified coating; and, optionally, a step of annealing the part, the article, or the solidified coating;wherein all or part of composition C is, during the cooling step and the annealing step, in the embodiments where an annealing step is implemented, at a temperature in the temperature range between the glass transition temperature of the polyaryletherketone, denoted Tg, and the melting temperature of the polyaryletherketone, denoted Tf, preferably in the temperature range from Tg+15°C to Tf-15°C, for a duration at least 2 times greater, or 5 times greater, or 10 times greater, or 25 times greater, or 100 times greater, than the minimum isothermal half-crystallization time of the polyaryletherketone.;

[0128] According to certain embodiments, the constituent elements of composition C may be mixed during a melt mixing step so as to form composition C in situ during the object manufacturing process. Any melt mixing apparatus known to those skilled in the art for preparing polymer compositions by melt mixing may be used. Suitable melt mixing apparatus are, for example, kneaders, Banbury mixers, single-screw extruders and twin-screw extruders. Preferably, an extruder equipped with means for metering all the desired components into the extruder, in the main hopper of the extruder and / or by side feed, is used.

[0129] According to certain embodiments, the provision of the constituent elements of composition C corresponds to the provision of granules of compositions C. The PAEK then forms a matrix incorporating the nucleating charge. The method comprises a heating step such as to obtain composition C in the molten state. This composition C can be extruded, injected, or melted, optionally in a mold.

[0130] The method also comprises a step of cooling the composition C from the molten state to a solid state, so as to obtain a solidified object (part, article, or coating). The cooling step makes it possible to cool the molten composition C to a temperature lower than or equal to the glass transition temperature, noted Tg, of the PAEK, and in particular to room temperature. Cooling means generally make it possible to ensure the cooling of the object from the outside (e.g.: air, air blowing, thermostatically controlled oven, thermostatically controlled mold). For thick objects, in particular having a thickness strictly greater than 2 mm, there is therefore generally during the cooling step a temperature gradient between the core and the periphery of the object in contact with the external environment.

[0131] According to certain embodiments, the method comprises a step of annealing the solidified object. This step consists of heating the object between the glass transition temperature, denoted Tg, of the PAEK and the melting temperature of the PAEK, denoted Tf. It can in particular make it possible to relax the stresses and / or increase the crystallinity rate. For thick objects, in particular for objects having a thickness strictly greater than 2 mm, there is also generally during the annealing step a temperature gradient between the core and the periphery of the object in contact with the external environment.

[0132] All or part of the composition C is during the cooling step and the annealing step, in the embodiments where an annealing step is implemented, in the temperature range between Tg and Tf, for a duration at least 2 times greater than the minimum isothermal half-crystallization time of the polyaryletherketone. This duration corresponds to the duration only of the cooling step, in the embodiments where no annealing is implemented, during which all or part of the composition C was at a temperature in the temperature range between Tg and Tf. This duration corresponds to the total duration of the cooling step and the annealing step, in the embodiments where annealing is implemented, during which all or part of the composition C was at a temperature in the temperature range between Tg and Tf.

[0133] According to certain embodiments, the entire composition C is, during the cooling step and, where appropriate, the annealing step, the total duration being considered, at a temperature in the temperature range between Tg and Tf, for a duration at least twice the minimum isothermal half-crystallization time of the polyaryletherketone.

[0134] For PEKK and PEEK, the temperature at which the minimum half-crystallization time is found is generally between 230° and 250°C. As an indication, the half-crystallization time at 250°C of a PEEK homopolymer consisting of the repeating unit (III) or of a PEKK consisting of the repeating units (I) and (II) with a T / l ratio equal to 80 / 20 is less than one minute. The half-crystallization time of a PEKK consisting of the repeating units (I) and (II) with a T / l ratio equal to 70 / 30 is of the order of one minute.

[0135] In some embodiments, the time is 5 times greater, or 10 times greater, or 25 times greater, or 100 times greater than the minimum isothermal half-crystallization time of the polyaryletherketone.

[0136] According to some embodiments, the duration may be calculated for the temperature range from Tg+10°C to Tf-10°C, or from Tg+15°C to Tf-15°C, or from Tg+20°C to Tf-20°C, or from Tg+25°C to Tf-25°C.

[0137] According to certain embodiments, all or part of composition C is, during the cooling step and, where appropriate, the annealing step, the total duration being considered, at a temperature in the temperature range between Tg+10°C and Tf-10°C, for a duration at least 25 times greater than the minimum isothermal half-crystallization time of the polyaryletherketone.

[0138] According to certain embodiments, all of composition C is during the cooling step and, where appropriate, the annealing step, the total duration being considered, at a temperature in the temperature range between Tg+10°C and Tf-10°C, for a duration at least 25 times greater than the minimum isothermal half-crystallization time of the polyaryletherketone.

[0139] A method according to the invention relates in particular to a method chosen from the following methods: molding, in particular injection molding or compression molding, additive manufacturing by filament fusion (FFF), extrusion of films of sheets, or plates, calendering extrusion, extrusion of tubes, pipes or bars, extrusion sheathing, extrusion-compression, injection-compression, spinning, rotational molding, thermoforming, and coating.

[0140] Preferably, a method according to the invention relates to a method chosen from the following methods: extrusion of sheets or plates, extrusion of bars and extrusion-compression. These methods all relate to the manufacture of thick objects, with a fairly slow cooling step.

[0141] According to certain embodiments, the manufactured objects (part, article, coating) have a thickness, in particular a characteristic thickness, greater than 1 mm, or greater than 2 mm, or greater than 3 mm, or greater than 4 mm, or greater than 5 mm, or greater than 6 mm. For objects, such as bars, in particular cylindrical bars, the thickness can even be much greater, in particular greater than 10 mm, or greater than 25 mm, or greater than 50 mm, or greater than 100 mm, or even greater than 150 mm. The term "thickness" means the smallest measurement of distance between two opposite surfaces of an object in a direction perpendicular to these surfaces. In other words, the thickness is the minimum distance to pass from one surface to the other by following a straight line perpendicular to the surfaces. The thickness of sheets, plates or tubes corresponds to the distance between the two main faces of these objects.For a cylindrical bar (in English rod), the thickness is measured perpendicular to the axis of revolution of the cylinder and corresponds to the diameter of a circle.

[0142] The manufactured objects (part, article, coating) have a high crystallinity, generally comparable to that of objects manufactured according to the same process under similar conditions with a non-additive composition (i.e. composition C without the nucleating filler). For example, for a composition C consisting of PEKK consisting of repeating units (I) and (II) with a T / l ratio equal to approximately 80 / 20, a nucleating filler and possibly other additive(s), a crystallinity level greater than or equal to 15%, and preferably greater than or equal to 20%, can generally be achieved. In addition, for a composition C consisting of PEKK consisting of repeating units (I) and (II) with a T / l ratio of approximately 70 / 30, a nucleating filler and possibly other additive(s), a crystallinity level greater than or equal to 10%, and preferably greater than or equal to 15%, can generally be achieved.

[0143] According to certain embodiments, the manufactured objects (parts, article, coating) also have the following properties: an average spherulite size at least 2 times smaller than that of an object obtained according to the same method using a non-additive composition (i.e. the composition according to the invention without the nucleating filler); and / or an elongation at break greater than the elongation at the yield point in at least 30% of cases. This number corresponds to the value expressed as a percentage of the “Nb ductility” divided by the number of specimens tested, according to the methodology indicated in the examples below. In other words, out of 10 specimens tested, the number of specimens having exceeded the yield point before breaking is 4 or more.

[0144] The objects manufactured by a method according to the invention, in particular from a composition C consisting of a polyetherketoneketone consisting of isophthalic and terephthalic units, and preferably having a T / l ratio of 72 / 28 to 85 / 15, advantageously have the following properties: an average spherulite size ranging from 1.5 pm to 2.0 pm; and / or an elongation at break greater than the elongation at the threshold in at least 30% of cases; and / or a crystallinity rate greater than or equal to 15%.

[0145] Examples

[0146] Raw materials

[0147] Polyetherketoneketone with a T / l ratio of 80 / 20, suitable for extrusion: PEKK KEPSTAN®, marketed by Arkema, from the 8000 series, grade suitable for extrusion with a viscosity of 860 Pa.s at 380°C. This PEKK has a glass transition temperature of 165°C, a melting temperature of 355°C, and an isothermal half-crystallization time at 250°C of less than 1 minute.

[0148] Talc 1: Talc having a particle size distribution (gravity sedimentation) such that d50=0.75Dm and d95=2.9 Dm.

[0149] Talc 2: Talc Jetfine® 07, marketed by Imerys. This talc has a particle size distribution (gravity sedimentation) such that d50=0.7Dm and d95=2.5Dm.

[0150] Talc 3: Talc Micro Talc IT EXTRA®, marketed by Elementis. This talc has a particle size distribution (gravity sedimentation) such that d50=1.8 Dm and d96=6.5 Dm.

[0151] Fabrication of specimens simulating object fabrication with slow cooling with or without annealing (or rapid cooling with annealing)

[0152] Type 1 BA specimens according to ISO 527-2:2012 were manufactured by injection molding. The injection conditions were as follows:

[0153] Nozzle temperature: 380°C,

[0154] Mold temperature: 80°C.

[0155] The specimens thus produced were amorphous due to very rapid cooling.

[0156] The amorphous specimens were then heat treated as follows to simulate slow cooling: they were remelted at a temperature of 365°C then placed at a temperature of 340°C and maintained at this temperature for 30 minutes, and finally cooled at a rate of 3.3°C / min to 25°C. The temperature profile of the heat treatment therefore requires that the specimen remains for a time equal to: 30 + (355-165) / 3.3 = 88 minutes between the glass transition temperature and the melting temperature of KEPSTAN® PEKK and Tf, which corresponds to a cooling much greater than the half-crystallization time at 350°C.Mechanical tests of elongation at break, at 23°C and 50%RH, according to the ISO 527-1:2019 standard, with a crosshead speed of 25 mm / min, were then carried out successively on 10 specimens of the same composition as prepared above in order to determine their more or less good ductile behavior properties (i.e. the break occurs after the plasticity threshold) or brittle behavior (i.e. the break occurs before the appearance of a plasticity threshold).

[0157] Influence of talc rate (Talc 1)

[0158] Specimens of compositions consisting of PEKK KEPSTAN® and Talc 1 were prepared by varying the talc content. The results of the elongation at break tests are presented in Table 1 below. The field "%m Talc 1" indicates the mass proportion of Talc 1 in relation to the total weight of the specimen consisting of PEKK KEPSTAN® and Talc 1. The field "Nb ductility" indicates the number of specimens of a given composition having a ductile character in relation to the 10 specimens tested of this composition.

[0159] Table 1

[0160] The results in Table 1 show that: the addition of a small amount of nucleating filler improves the ductility of the specimen (compare specimens #2 - #4 with the comparative specimen #1 c); the addition of too large a quantity of nucleating filler deteriorates the ductility of the specimen (compare the comparative specimen #5c with the comparative specimen #1 c); there is an optimal composition having a mass proportion of Talc 1 between 0.25% and 1.00%, particularly close to 0.50%, for which the specimen has the best ductility properties.

[0161] Influence of the nature of talc at a mass proportion of talc of 0.50%

[0162] Test specimens of compositions consisting of PEKK KEPSTAN® and talcs (Talc 1, Talc 2, Talc 3) were prepared according to the same procedure as for the previous example with a talc proportion of 0.50% by weight, relative to the total weight of the specimens. The results of the elongation at break tests are presented in Table 2 below.

[0163] Table 2

[0164] The results in Table 2 show that: all talcs (Talc 1, Talc 2, Talc 3) incorporated in a proportion equal to 0.5% by mass relative to the total weight of the composition, make it possible to improve the ductility of the specimens (compositions compare specimens #3, #6 and #7 with specimen #1 c); the size of the talcs has an influence on the ductility. Talcs with a d50 < 1.5 pm are particularly preferred (compare specimens #3 and #6 with specimen #7).

[0165] Spherulite size and crystallinity

[0166] The average size of the spherulites was observed by transmission electron microscopy on sections of approximately 40 nm obtained by ultracryomicrotomy at - 100°C.

[0167] The spherulites in specimen #1 c have an average size of approximately 4 pm.

[0168] The spherulites of specimens #2 - #4; #6 - #7 have an average size ranging from 1.5 to 2 pm. The crystallinity rate measured by WAXS does not depend on the proportion and / or nature of the talc used. It was measured for all specimens #1c, #2 - #4, #5c, #6 - #7 at 23%.

Claims

Claims 1. Composition C based on at least one semi-crystalline or pseudo-amorphous polyaryletherketone comprising from 0.2% to 1.2% by weight of a nucleating filler, relative to the total weight of polyaryletherketone(s) and nucleating filler, said nucleating filler being chosen from a silicate, a carbon material having a BET specific surface area greater than or equal to 200 g / m 2 , or their mixture.

2. Composition according to claim 1, in which said nucleating charge represents from 0.25% to 1.0% by weight, relative to the total weight of polyaryletherketone(s) and nucleating charge.

3. Composition according to any one of claims 1 and 2, in which said nucleating charge represents 0.5% or more by weight, relative to the total weight of polyaryletherketone(s) and nucleating charge.

4. Composition according to any one of claims 1 to 3, in which said nucleating charge represents 0.9% or less by weight, or 0.8% or less by weight, or 0.75% or less by weight, relative to the total weight of polyaryletherketone(s) and nucleating charge. 5.Composition according to any one of claims 1 to 4, in which the at least one polyaryletherketone is a semi-crystalline polyaryletherketone.

6. Composition according to any one of claims 1 to 5, in which the at least one polyaryletherketone is a polyetherketoneketone. / .Composition according to claim 6, in which the at least one polyaryletherketone is a polyetherketoneketone, essentially consisting of, or consisting of, a terephthalic repeating unit, and where appropriate of an isophthalic repeating unit, the terephthalic repeating unit having the formula: the isophthalic repeating pattern having the formula: said polyetherketoneketone having a mass proportion of units of formula (I) relative to the totality of the units of formula (I) and formula (II) ranging from 55% to 100%, preferably from 65% to 95%, more preferably from 70% to 90%, and more preferably from 72% to 85%. 8.Composition according to any one of claims 1 to 7, in which said at least one polyaryletherketone forms a matrix incorporating said nucleating charge.

9. Composition according to any one of claims 1 to 8, in which said nucleating charge is a carbon material chosen from the list consisting of carbon black, carbon nanotubes, graphene, or their mixture.

10. Composition according to any one of claims 1 to 9, in which said nucleating charge is a carbonaceous material having a BET specific surface area greater than or equal to 300 g / m 2 , preferably greater than or equal to 400 g / m2 , and more preferably greater than or equal to 500 g / m 2 .

11. Composition according to any one of claims 1 to 8, in which said nucleating charge is a talc.

12. A composition according to any one of claims 1 to 11, wherein said nucleating charge has a particle size distribution, measured by gravity sedimentation in a liquid according to ISO 13317-3:2001, of such that the median diameter d50 is such that d50 < 4 pm, and preferably such that d50 < 2 pm.

13. A composition according to any one of claims 1 to 12, wherein said nucleating charge has a particle size distribution, measured by gravity sedimentation in a liquid according to ISO 13317-3:2001, such that the median diameter d50 is such that d50 < 1.5 pm.

14. Composition according to any one of claims 1 to 13, wherein said nucleating charge has a particle size distribution, measured by gravity sedimentation in a liquid according to ISO 13317-3:2001, such that d95 < 8 pm, and preferably such that d95 < 4 pm.

15. A method of manufacturing a part, an article or a coating of composition C comprising: providing the constituent elements of a composition C according to any one of claims 1 to 14; a heating step so as to obtain the composition C in the molten state; a cooling step of the composition C, from the molten state to a solid state, so as to obtain a solidified part, an article, or a coating; and, optionally, a step of annealing the solidified part, the article, or the coating;wherein all or part of composition C is, during the cooling step and the annealing step, in the embodiments where an annealing step is carried out, at a temperature in the temperature range between the glass transition temperature of the polyaryletherketone, denoted Tg, and the melting temperature of the polyaryletherketone, denoted Tf, preferably in the temperature range from Tg+10°C to Tf-10°C, for a duration at least 2 times greater, or at least 5 times greater, or at least 10 times greater, or at least 25 times; greater than, or at least 100 times greater than, the minimum isothermal half-crystallization time of polyaryletherketone.

16. Method according to claim 15, wherein said method is chosen from the following methods: molding, in particular injection molding or compression molding, additive manufacturing by filament fusion (FFF), extrusion of films of sheets, or plates, calendering extrusion, extrusion of tubes, pipes or bars, extrusion sheathing, extrusion-compression, injection-compression, spinning, rotational molding, thermoforming, and coating, and preferentially chosen from the following methods: extrusion of sheets or plates, extrusion of bars and extrusion-compression.

17. Part, article or coating obtained by any of the methods according to claim 15 or claim 16 having a thickness greater than 1 mm, or greater than 2 mm, or greater than 3 mm, or greater than 4 mm, or greater than 5 mm, or greater than 6 mm.

18. Part, article or coating according to claim 17, having spherulites of average size strictly less than 4 micrometers.

19. Part, article or coating according to any one of claims 17 and 18, having an elongation at break greater than the elongation at the yield point in at least 30% of cases.

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