Method for manufacturing a polyaryletherketone composition incorporating a nucleating agent

Abstract

The invention relates to a method for manufacturing a composition comprising a polyaryletherketone incorporating at least one nucleating agent, the method comprising: forming a reaction mixture by bringing polymerization reagents which are suitable for manufacturing a polyaryletherketone into contact with each other in all or part of a reaction solvent; dispersing the at least one nucleating agent in the reaction mixture that has been or is being formed; polymerizing the reaction mixture that has been formed in which the at least one nucleating agent has been dispersed, until the polyaryletherketone precipitates in the reaction solvent; and recovering the composition comprising the polyaryletherketone incorporating the at least one nucleating agent.

Description

[0001] Description

[0002] Title: Process for manufacturing a polyaryletherketone composition incorporating a nucleating agent

[0003] technical field

[0004] The invention relates to the field of polyaryletherketone(s)-based compositions.

[0005] More specifically, the invention relates to a process for manufacturing a polyaryletherketone composition incorporating at least one nucleating agent and the product obtainable by this process. The product resulting from this process is in the form of a low-density composition, particularly a more or less coarse powder, which has the advantage of being easily transformed into a fine powder by comminution, particularly by grinding.

[0006] Previous art

[0007] Polyaryletherketones (PAEKs) are well-known high-performance engineering polymers. They can be used in demanding applications involving high temperature and / or mechanical stress, and even chemical resistance. They are also suitable for applications requiring excellent fire resistance and low emissions of smoke or toxic gases. Finally, they exhibit good biocompatibility. These polymers are found in fields as diverse as aerospace, offshore drilling, automotive, rail, marine, wind energy, sports, construction, electronics, and medical implants.

[0008] Notwithstanding these advantageous properties, it is sometimes necessary to formulate polyaryletherketones to meet specific requirements. In particular, one might seek to formulate a polyaryletherketone-based composition to influence the crystallization rate and / or the microstructure of that composition.

[0009] Furthermore, for certain applications, it can also be advantageous to use the composition in powder form. Examples of applications where a powder composition is used include layer-by-layer object construction processes by sintering induced by electromagnetic radiation, coating processes, for example of metals, from a powder, powder compression molding, powder compression-transfer molding, or the impregnation of fibers with a resin powder for the manufacture of semi-finished products, the powder being able to be used in a fluidized bed or dispersed in an aqueous solution.

[0010] It is known that adding certain fillers to a polymer composition can influence, in particular, the crystallization and / or microstructure of that composition. The nature of the filler, as well as the proportion in which it is added, can modify certain desired properties, as illustrated by several examples from the prior art below.

[0011] US patent application US7790841, for example, discloses thermoplastic compositions with nanoparticles, the nanoparticles increasing the crystallization rate, crystallinity, and density of the composition. Compounds obtained by molten mixing of polyether-ketone-ketone and silica are specifically exemplified. Example 1a of US7790841 discloses, in particular, the introduction of 1 to 2 wt% of hydrophilic silica (Aerosil® R150) or hydrophobic silica (Aerosil® R202). This patent application does not disclose a powder formulation. Furthermore, it is known that such compounds cannot be transformed into a fine powder, as they are too hard to be ground.

[0012] The grinding of filled compounds is not impossible in itself. Application WO2021069833 discloses the grinding into fine powder of granules obtained by compounding a polyether-ketone-ketone composition comprising 30% by weight of talc. Such a quantity of talc considerably weakens the structure of the granules, thus making them suitable for grinding. The powders obtained according to Examples 3 and 4 of WO2021069833 were characterized in the experimental part of the present invention.

[0013] To utilize fine polyaryletherketone-based powders with a low filler content, a dry mix of polyaryletherketone powder and filler powder can be used. However, such powders have several disadvantages. They generally cannot be sieved when necessary, as sieving typically leads to segregation of the different components of the dry mix. Sieving might be necessary, for example, when recycling unsintered powder in a laser sintering process. Furthermore, when using a filler to increase the polymer's crystallization rate, the filler's effect on the polymer is expected to be diminished, or even significantly reduced, compared to homogeneous incorporation of the filler into the polymer through compounding.There is currently a need to supply polyaryletherketones, which can be used in the form of powders of varying fineness, incorporating a filler that notably increases the crystallization rate of the polymer. These fillers are referred to as nucleating agents in the present invention.

[0014] Objective of the invention

[0015] An objective of the invention is to propose a method for manufacturing a polyaryletherketone incorporating at least one nucleating agent in which the incorporation of said at least one nucleating agent is at least comparable to incorporation by a standard compounding process, i.e. allowing comparable effects on crystallization to be obtained, while allowing, if necessary, the obtaining of a fine powder of polyaryletherketone incorporating at least one nucleating agent, said at least one nucleating agent being able to be introduced in any proportion.

[0016] An objective of the invention is also to provide powders incorporating said at least one nucleating agent, which can be obtained according to a process of the invention.

[0017] Another objective, according to at least some embodiments, is that the powder composition according to the invention makes it possible to manufacture objects having a tensile elastic modulus analogous to that of objects manufactured under similar conditions from a powder devoid of said nucleating agent.

[0018] Summary of the invention

[0019] According to a first object, the invention relates to a method for manufacturing a composition comprising a polyaryletherketone incorporating at least one nucleating agent. The method comprises:

[0020] - the formation of a reaction mixture by bringing into contact polymerization reagents suitable for the manufacture of a polyaryletherketone, in all or part of a reaction solvent;

[0021] - the dispersion of said at least one nucleating agent in said reaction mixture formed or in said reaction mixture in the process of being formed;

[0022] - the polymerization of the reaction mixture formed in which said at least one nucleating agent has been dispersed, until the precipitation of the polyaryletherketone in said reaction solvent;

[0023] - the recovery of the composition comprising the polyaryletherketone incorporating said at least one nucleating agent. The inventors have observed, quite surprisingly, that the precipitation of a polyaryletherketone in a dispersion of a nucleating agent allows for the incorporation of almost all, if not all, of the nucleating agent into the precipitating polyaryletherketone. Furthermore, the inventors have observed that the presence of the nucleating agent in the reaction medium has no significant impact on the progress of a precipitating polymerization of the polyaryletherketone. In other words, a person skilled in the art, carrying out the manufacture of a polyaryletherketone by precipitating polymerization, does not need to modify the parameters of this polymerization to incorporate the nucleating agent into the polyaryletherketone.The inventors were also able to verify that incorporating a nucleating agent into a polyaryletherketone according to the process of the invention resulted in a comparable, or even slightly better, acceleration of the polyaryletherketone crystallization rate, for a given nucleating agent in a given proportion, compared to incorporation by compounding. Finally, precipitating the polyaryletherketone in a dispersion of the nucleating agent yields coarse particles with a density low enough to be easily ground into powders of varying fineness, if necessary, regardless of the proportion of nucleating agent.

[0024] According to certain embodiments, said at least one nucleating agent is selected from: carbon-based compounds, in particular carbon black, graphite, graphene, carbon fibers, carbon nanotubes, and graphene oxide; nitrides, in particular boron nitride; oxides, in particular aluminum oxide, aluminum titanium oxide, magnesium oxide, zinc oxide, graphene oxide, or antimony trioxide; silicas; silicates, in particular talc, sodium silicate, aluminum silicate, calcium silicate, or magnesium silicate; and mixtures thereof.

[0025] According to certain preferred embodiments, said at least one nucleating agent is a carbon-based compound. It may, in particular, be selected from the list consisting of: carbon black, carbon nanotubes, graphene, and mixtures thereof. According to these embodiments, said at least one nucleating agent advantageously has a specific surface area BET greater than or equal to 200 m². 2 / g. According to certain preferred embodiments, said at least one nucleating agent is a nitride. In particular, it may be a boron nitride and preferably have a hexagonal crystal structure. According to these embodiments, said at least one nucleating agent advantageously has a specific surface area BET greater than or equal to 20 m² 2 / g.

[0026] According to some embodiments, said at least one nucleating agent is a talc.

[0027] According to some embodiments, said at least one nucleating agent is a silica.

[0028] According to certain embodiments, said at least one nucleating agent has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter d50 is such that d50 < 20 pm. Preferably, d50 < 10 pm and even more preferably d50 < 5 pm.

[0029] According to certain embodiments, said at least one nucleating agent of the recovered composition represents from 0.1% to 5.0%, and preferably from 0.2% to 3.0% by weight, relative to the weight of said at least one polyaryletherketone of the recovered composition. An advantage of the invention is that the recovered composition comprising the polyaryletherketone incorporating said at least one nucleating agent can be transformed into a fine powder, in particular by grinding, if necessary, despite a low proportion of nucleating agent. Such a fine powder incorporating a low proportion of nucleating agent cannot be obtained from a compound of the same composition.

[0030] According to some embodiments, said at least one nucleating agent of the recovered composition represents from 0.25% to 2.5% by weight, relative to the weight of said at least one polyaryletherketone of the recovered composition.

[0031] In particular embodiments, the precipitating polymerization for the production of polyaryletherketone is carried out electrophilically. The polymerization reagents suitable for the production of polyaryletherketone then preferably comprise: at least one monomer including an aromatic ether group, at least one monomer including an acyl chloride group, and a Lewis acid.

[0032] In some embodiments, said at least one monomer comprising an aromatic ether function and said at least one monomer comprising an acyl chloride function are the same AB-type monomer. In some embodiments, said at least one monomer comprising an aromatic ether function and said at least one monomer comprising an acyl chloride function are two different monomers, respectively of AA-type and BB-type.

[0033] According to some embodiments, said at least one monomer comprising an aromatic ether function is diphenyl ether, 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or mixture thereof, and preferably 1,4-bis(4-phenoxybenzoyl)benzene.

[0034] According to some embodiments, said at least one monomer comprising an acyl chloride function is terephthaloyl chloride, isophthaloyl chloride, or a mixture thereof.

[0035] According to some embodiments, Lewis acid is aluminum trichloride.

[0036] According to some embodiments, said reaction solvent is chosen from the group consisting of: dichloromethane, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, ortho-difluorobenzene, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene, and mixtures thereof, preferably from the group consisting of: ortho-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, and mixtures thereof, and most preferably is ortho-dichlorobenzene.

[0037] According to advantageous embodiments, in the process according to the invention, the formation of the reaction mixture and the dispersion of said at least one nucleating agent comprises: contacting said at least one monomer comprising an aromatic ether function with said at least one nucleating agent in all or part of the reaction solvent to obtain a first mixture; drying the first mixture; and adding said at least one monomer comprising an acyl chloride function to said first mixture to obtain a second mixture.

[0038] According to advantageous embodiments, the formation of the reaction mixture includes the addition of the Lewis acid after the addition of said at least one acyl chloride.

[0039] According to some embodiments, the dispersion of said at least one nucleating agent in said reaction mixture being formed or in said reaction mixture formed, comprises the addition of a pre-dispersion of said at least one nucleating agent in a fraction of reaction solvent to the reaction mixture being formed or to the reaction mixture formed.

[0040] According to some embodiments, the recovered composition comprising the polyaryletherketone incorporating said at least one nucleating agent is transformed into a powder having a volume-weighted particle size distribution measured by laser diffraction according to ISO 13320:2009 such that the median diameter D50 is such that D50 < 500 pm, notably by a comminution step.

[0041] According to a second object, the invention relates to a powder comprising particles including at least one polyaryletherketone and at least one nucleating agent, said at least one nucleating agent being incorporated within said at least one polyaryletherketone, said powder having a packed density greater than or equal to 150 kg / m³ 3 and less than or equal to 500 kg / m 3 .

[0042] According to some embodiments, fine powders can be obtained, which was not possible by incorporating a nucleating agent by compounding in polyaryletherketone.

[0043] According to some embodiments, the powder has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 500 pm.

[0044] According to some embodiments, the powder has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 300 pm.

[0045] According to some embodiments, the powder has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 150 pm.

[0046] According to some embodiments, the powder has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 30 pm.

[0047] In some embodiments, said at least one nucleating agent of the powder represents from 0.1% to 5.0%, preferably from 0.2% to 3.0% by weight, relative to the weight of said at least one polyaryletherketone of the powder. In some embodiments, the powder may be characterized by a tensile modulus at 23°C of 3.5 GPa to 5.5 GPa, and preferably from 3.8 GPa to 5.0 GPa, as measured on a type 1 BA test specimen manufactured by injection molding, with a through-feed speed of 1 mm / min, according to ISO 527-2:2012.

[0048] The aforementioned powders are capable of being obtained by a process according to the invention.

[0049] Detailed description of the invention

[0050] Definitions

[0051] The term "powder" refers to a fractionated state of matter, generally in the form of particles. The term "pulverulent" refers to a state of matter that is entirely in the form of a powder.

[0052] The particle size distribution of a powder can be measured by laser diffraction according to ISO 13320:2009. For example, the particle size distribution of polyaryletherketone(s)-based powder can be measured on an Insitec®-type Malvern diffractometer. The rules for representing particle size distribution results are given in ISO 9276, parts 1 to 6.

[0053] The term "D50" refers to the particle diameter value of polyaryletherketone(s)-based powder at which the volume-weighted cumulative particle diameter distribution function equals 50%. Similarly, "D10" and "D90" refer to the diameters at which the volume-weighted cumulative particle diameter distribution function of polyaryletherketone(s)-based powder equals 10% and 90%, respectively.

[0054] The term "coarse" powder means a powder having a particle size distribution such that D50 > 500 pm.

[0055] The term "fine powder" refers to a powder with a particle size distribution such that D50 < 500 pm, and preferably D50 < 300 pm. The D50 value can be adjusted according to the desired D50. For example, D50 < 150 pm or D50 < 30 pm.

[0056] The term "d50" refers to the diameter of the nucleating agent particles in powder form such that the volume-weighted cumulative particle diameter distribution function is equal to 50%. Similarly, "d10" and "d90" refer to the diameters such that the volume-weighted cumulative particle diameter distribution function is equal to 10% and 90%, respectively. "Specific surface area" refers to the ratio of the actual surface area of ​​a powder to the amount of powder in question. It is expressed in m². 2 / g. It can be measured by adsorption of nitrogen gas onto the powder and determined using the Brunauer-Emmett-Tellery (BET) equation according to ISO 9277:2022.

[0057] The "tamped density" of a powder, also known as packed density, refers to the mass density of the powder after it has been compacted to reduce the space between the particles. The packed density is measured in the present invention according to ISO 1068-1975(F), adapted as follows:

[0058] - Condition the powder for 24 hours at 23°C and 50% RH;

[0059] - Introduce a volume of powder into a 250 ml graduated precision glass test tube;

[0060] - Level the free surface of the powder if necessary without compacting it and note the volume V0;

[0061] - Weigh the test tube with the powder using a precision balance accurate to 0.01 g, the tare of which has been previously carried out;

[0062] - Place the test specimen on the platform of the STAV 2003 type compaction device;

[0063] - Pack with 1250 drops, note the volume V1;

[0064] - Pack with 1250 drops, note the volume V2;

[0065] - Repeat the compaction operation until two equivalent volumes Vi are obtained.

[0066] - Note Vf corresponding to identical volumes Vi.

[0067] The packed density is the mass of powder introduced divided by Vf. It is expressed in kg / m³ 3 .

[0068] The singular forms "a" and "the" applied to the constituents of the reaction mixture or to the nucleating agent mean by default "at least one" and respectively "the said at least one". The singular forms nevertheless include, without needing to be stated each time, the embodiments where "a" means "only one" and "the" means "the only one".

[0069] In all the ranges of values ​​stated in this application, the limits are included unless otherwise stated.

[0070] The process according to the invention comprises: the formation of a reaction mixture by contacting polymerization reagents suitable for the manufacture of a polyaryletherketone, in all or part of a reaction solvent; the dispersion of at least one nucleating agent in said reaction mixture during formation or in the reaction mixture formed; the polymerization of the reaction mixture formed in which said at least one nucleating agent is dispersed, until precipitation in said reaction solvent of a polyaryletherketone incorporating said at least one nucleating agent; the recovery of said polyaryletherketone incorporating said at least one nucleating agent.

[0071] Polyaryletherketone

[0072] A polyaryletherketone (PAEK) contains the following formula units:

[0073] (-Ar-X-) and (-An-Y-), in which:

[0074] - Ar and An each designate a divalent aromatic radical;

[0075] - Ar and An can be chosen, preferably, 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;

[0076] - X designates an electron-withdrawing group; it can preferably be chosen from among the carbonyl group and the sulfonyl group,

[0077] - Y designates a group chosen from an oxygen atom, a sulfur atom, an alkylene group, such as -(CH)2- and isopropylidene.

[0078] In these motifs X and Y, 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.

[0079] According to a preferred embodiment, 100% of the X groups denote a carbonyl group and 100% of the Y groups represent an oxygen atom.

[0080] Advantageously, the PAEK(s) can / can be chosen from:

[0081] - a poly-ether-ketone-ketone, also called PEKK; a PEKK comprises one or more motif(s) of formula: -Ph-O-Ph-C(O)-Ph-C(O)-;

[0082] - a poly-ether-ether-ketone, also called PEEK; a PEEK comprises one or more motif(s) of formula: -Ph-O-Ph-O-Ph-C(O)-;

[0083] - a polyetherketone, also called PEK; a PEK includes one or more motif(s) of formula: -Ph-O-Ph-C(O)-;

[0084] - a poly-ether-ether-ketone-ketone, also called PEEKK; a PEEKK comprises one or more motif(s) of formula: -Ph-O-Ph-O-Ph-C(O)- Ph-C(O)- ;

[0085] - a polyether-ether-ether-ketone, also called PEEEK; a PEEEK comprises one or more motifs of the formula: -Ph-O-Ph-O-Ph-O- Ph-C(O)-; - a polyether-diphenyl-ether-ketone also called PEDEK; a PEDEK comprises one or more motifs of the formula: a PEDEK comprises one or more motifs of the formula -Ph-O-Ph-Ph-O-Ph-C(O)-;

[0086] - their mixtures; and,

[0087] - copolymers comprising at least two of the aforementioned motifs, in which: Ph represents a phenylene group and -C(O)- a carbonyl group, each of the phenylenes being independently of type ortho (1-2), meta (1-3) or para (1-4), preferably being of type meta or para.

[0088] In addition, defects, terminal groups and / or monomers may be incorporated in very small quantities into the polymers as described in the list above, without affecting their performance.

[0089] According to certain embodiments, particularly as exemplified in the invention, PAEK is a polyetherketoneketone (PEKK), essentially composed of, and preferably composed of: a terephthalic repeating unit and an isophthalic repeating unit, the terephthalic repeating unit ("T-repeat") having the formula:

[0090] [Chem 1] the isophthalic motif (“motif I”) having the formula: [Chem 2]

[0091] The mass proportion of T motifs relative to the sum of T and I motifs can vary from 0% to 100%. Choosing the molar proportion of T motifs relative to the sum of T and I motifs is one of the factors that allows adjusting the melting temperature and crystallization rate properties of polyetherketones. A given molar proportion of T motifs relative to the sum of T and I motifs can be obtained by adjusting the respective concentrations of the reactants during polymerization, in a manner known per se. The mass proportion of T motifs relative to the sum of T and I motifs can be from 0% to 15%, or from 15% to 45%, or from 45% to 55%, or from 55% to 65%, or from 65% to 75%, or from 75% to 85%, or from 85% to 100%.

[0092] The process according to the invention relates to the manufacture of a polyaryletherketone by precipitative polymerization of polymerization reagents in a reaction solvent. The growing polymer chains are initially essentially soluble in the reaction solvent and eventually precipitate beyond a certain molecular weight. Such processes for the polymerization of polyaryletherketones by precipitative polymerization are known to those skilled in the art.

[0093] Nucleating agent

[0094] A nucleating agent is a substance that promotes nucleation. In particular, it accelerates the crystallization rate of polyaryletherketone when the latter is heated above its glass transition temperature. The nucleating agent according to the invention may be selected from: carbon-based compounds, including carbon black, graphite, graphene, carbon fibers, carbon nanotubes, and graphene oxide; nitrides, including boron nitride; oxides, including aluminum oxide, aluminum titanium oxide, magnesium oxide, zinc oxide, graphene oxide, or antimony trioxide; silicas; silicates, including talc, sodium silicate, aluminum silicate, calcium silicate, magnesium silicate, or iron silicate; or mixtures thereof.

[0095] According to some embodiments, the nucleating agent has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter d50 is such that d50 < 20 pm, preferably d50 < 10 pm, and preferably d50 < 5 pm. In particular, 0.05 pm < d50 < 5 pm may be considered.

[0096] According to some embodiments, the nucleating agent has a specific surface area BET greater than or equal to 200 m² 2 / g. The specific surface area of ​​BET can notably be greater than or equal to 300 m² 2 / g, or greater than or equal to 400 m 2 / g, or greater than or equal to 500 m 2 / g, or greater than or equal to 600 m 2 / g, or greater than or equal to 700 m 2 / g, or greater than or equal to 800 m 2 / g, or greater than or equal to 900 m 2 / g, or greater than or equal to 1000 m 2 / g.

[0097] In some embodiments, the nucleating agent may be a carbon-based compound. It is preferably selected from a list consisting of: carbon black, graphite, graphene, carbon fibers, carbon nanotubes, graphene oxide, and mixtures thereof. In preferred embodiments, the nucleating agent may be selected from a list consisting of carbon black, carbon nanotubes, graphene, and mixtures thereof. The nucleating agent may, in particular, be carbon black, as exemplified in the invention. In embodiments where the nucleating agent is a carbon-based compound, it preferably has a BET greater than or equal to 200 m 2 / g. The BET may, in particular, be greater than or equal to 300 m 2 / g, or greater than or equal to 400 m 2 / g, or greater than or equal to 500 m 2 / g, or greater than or equal to 600 m 2 / g, or greater than or equal to 700 m 2 / g, or greater than or equal to 800 m 2 / g, or greater than or equal to 900 m 2 / g, or greater than or equal to 1000 m 2 / g.

[0098] In some embodiments, the nucleating agent can be a silicate, that is, a mineral comprising in its structure one or more anions of chemical formula: SiO4-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. The nucleating agent may, in particular, be chosen from: talc, mica, kaolin, or a mixture thereof. The nucleating agent may, in particular, be talc, as exemplified in the invention. In embodiments where the nucleating agent is a silicate, it preferably has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter d50 is such that d50 < 10 pm or d50 < 5 pm. In particular, 0.05 pm < d50 < 5 pm may be obtained.

[0099] In some embodiments, the nucleating agent is a nitride. The nitride may, in particular, be selected from aluminum nitride, antimony nitride, beryllium nitride, boron nitride, chromium nitride, copper nitride, gallium nitride, trigermanium dinitride, trigermanium tetranitride, hafnium nitride, iron nitride, mercury nitride, niobium nitride, silicon nitride, tantalum nitride, titanium nitride, tungsten dinitride, vanadium nitride, zinc nitride, and zirconium nitride. In preferred embodiments, the nucleating agent is boron nitride. Preferably, boron nitride has a hexagonal crystal structure. The nucleating agent may, in particular, be a turbostratified hexagonal boron nitride, as exemplified in the invention.In embodiments where the nucleating agent is a nitride, it preferably has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter d50 is such that d50 < 20 pm, preferably also such that d50 <.

[0100] 10 pm, and more preferably such that d50 < 5 pm. In particular, 0.01 pm < d50 < 5 pm is acceptable. In embodiments where the nucleating agent is a nitride,

[0101] 11 preferably has a BET greater than or equal to 20 m 2 / g.

[0102] The process according to the invention allows for the homogeneous incorporation, almost entirely or entirely, of a nucleating agent into a polyaryletherketone, which polymerizes in situ and precipitates in a dispersion of nucleating agent(s). The process according to the invention thus makes it possible to prepare a composition C comprising a polyaryletherketone (precipitant) and at least one nucleating agent, said at least one nucleating agent being incorporated into a polyaryletherketone matrix.

[0103] The advantage of the process according to the invention is that it allows obtaining a composition C incorporating a greater or lesser quantity of nucleating agent in a polyaryletherketone matrix, and that this composition can be easily transformed into a fine powder, particularly by comminution, even for very low loading levels of nucleating agent(s). Said at least one nucleating agent, that is to say the nucleating agent or, where applicable, the nucleating agents, generally represents less than 10% by weight relative to the weight of the precipitating polyaryletherketone. In embodiments where several nucleating agents are used, this proportion corresponds to the mass proportion of all the nucleating agents relative to the weight of the precipitating polyaryletherketone.

[0104] According to preferred embodiments, said at least nucleating agent represents from 0.1% to 5.0% by weight, relative to the weight of the precipitating polyaryletherketone.

[0105] In more preferred embodiments, said at least one nucleating agent represents from 0.15% to 3.0% by weight, relative to the weight of the precipitating polyaryletherketone. In particular, it may represent from 0.15% to 0.25%, or from 0.2% to 1.0%, or from 1.0% to 1.5%, or from 1.5% to 2.0%, or from 2.0% to 2.5%, or from 2.5% to 3.0% by weight, relative to the weight of the precipitating polyaryletherketone in composition C.

[0106] According to some embodiments, the polyaryleterketone and said at least one nucleating agent constitute at least 95% by weight, or at least 96% by weight, or at least 97% by weight, or at least 98% by weight, or at least 99% by weight of the total weight of composition C.

[0107] According to some embodiments, composition C is essentially made up of, or made up of, polyaryletherketone incorporating the nucleating agent(s).

[0108] Illustration of the incorporation of a nucleating agent in a process for manufacturing a polvether-ketone-ketone (PEKK) produced electrophilically.

[0109] The description below details the electrophilic synthesis of a polyetherketone-ketone. Those skilled in the art would be able to make the necessary adaptations to select monomers other than those shown below to produce a polyaryletherketone other than a polyetherketone-ketone, and / or would be able to make the necessary adaptations to carry out a precipitating polymerization reaction by a route other than the one presented.

[0110] The precipitating polymerization reaction used to manufacture PEKK via electrophilic means is a polycondensation reaction involving electrophilic substitution between one or more monomers containing at least one aromatic ether group and one or more monomers containing at least one acyl chloride group, in the presence of a Lewis acid and optionally a chain-limiting agent in a reaction solvent. The polymerization reaction is also precipitating because the polymer formed precipitates in the reaction medium. It is also exothermic. Hydrogen chloride is produced during the polycondensation.

[0111] The monomer comprising at least one acyl chloride function preferably has two acyl chloride functions. It can be chosen from the group consisting of: terephthaloyl chloride, isophthaloyl chloride, and mixtures thereof.

[0112] Several measures can be taken to ensure that the acyl chloride(s) used have a satisfactory degree of purity. Acyl chlorides are readily hydrolyzable and may contain impurities such as hydrolyzed compounds if they are not stored and / or handled under appropriate conditions.

[0113] In particular, acyl chlorides must not come into contact with water and / or a humid atmosphere at any time before being introduced into the reactor. It may therefore be advantageous to store acyl chlorides in a sealed container without contact with ambient air, or alternatively in a container with dry air. Advantageously, acyl chlorides can be kept under a dry nitrogen atmosphere before being introduced into the reactor to prevent any contact with ambient air.

[0114] The monomer comprising at least one aromatic ether function may be chosen from the group consisting of: diphenyl ether, 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or mixture thereof.

[0115] The chemical formula of 1,3-bis(4-phenoxybenzoyl)benzene is:

[0116] [Chem 3]

[0117] The chemical formula of 1,4-bis(4-phenoxybenzoyl)benzene is:

[0118] According to some embodiments, the monomer comprising at least one aromatic ether function comprises at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 95%, or at least 99% by moles of 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene, considered where appropriate as a whole, relative to the total number of moles of monomer(s) comprising at least one aromatic ether function.

[0119] In some embodiments, a mixture of monomers comprising an aromatic ether group is used. It may consist essentially of, or consist of, 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene. It may also consist of 1,4-bis(4-phenoxybenzoyl)benzene and diphenyl ether. The mixture may comprise up to 20 mole percent, preferably up to 10 mole percent, more preferably up to 5 mole percent, and extremely preferably up to 1 mole percent of diphenyl ether, relative to the total number of moles of 1,4-bis(4-phenoxybenzoyl)benzene and diphenyl ether.

[0120] According to some embodiments, the monomer comprising at least one aromatic ether function is essentially made up of, or made up of, 1,4-bis(4-phenoxybenzoyl)benzene.

[0121] The Lewis acid may be chosen from the group consisting of: aluminium trichloride, aluminium tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, stannic chloride, titanium tetrachloride, molybdenum pentachloride, and mixtures thereof.

[0122] Preferably, only one type of Lewis acid is used in the polymerization reaction.

[0123] Of the Lewis acids mentioned above, aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, ferric chloride, gallium trichloride, and molybdenum pentachloride are preferred. Aluminum trichloride is particularly preferred.

[0124] Preferably, the Lewis acid is added in solid form. Alternatively, it can also be added as a suspension or colloid, that is, as a heterogeneous mixture of solid Lewis acid particles in a solvent, or as a solution, that is, as a homogeneous mixture in a solvent. The solvent of the suspension / colloid or solution is advantageously the reaction solvent.

[0125] The reaction solvent may be chosen from the group consisting of: dichloromethane, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, ortho-difluorobenzene, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene, and mixtures thereof. Preferably, the reaction solvent may be chosen from the group consisting of: ortho-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, and mixtures thereof. Ortho-dichlorobenzene is particularly preferred.

[0126] The reaction solvent preferably contains less than 500 ppm by weight of water to limit the hydrolysis of the acyl chloride groups. Advantageously, the reaction solvent contains less than 250 ppm by weight of water, preferably less than 150 ppm by weight of water, and more preferably less than 100 ppm by weight of water. In preferred embodiments, the monomer comprising an aromatic ether group or the mixture of monomers comprising an aromatic ether group also preferably contains less than 500 ppm by weight of water to limit the hydrolysis of the acyl chloride groups. The same preferred ranges of values ​​as for the reaction solvent apply mutatis mutandis to the monomer comprising an aromatic ether group or the mixture of monomers comprising an aromatic ether group.

[0127] In other preferred variants, the nucleating agent or mixture of nucleating agents also preferably contains less than 500 ppm by weight of water to limit the hydrolysis reaction of the acyl chloride groups. The same preferred ranges of values ​​as for the reaction solvent apply mutatis mutandis to the nucleating agent.

[0128] In embodiments where a chain-limiting agent is used, the chain-limiting agent advantageously contains less than 500 ppm by weight of water to limit the hydrolysis reaction with the acyl chloride groups. The same preferred ranges of values ​​as for the reaction solvent apply mutatis mutandis to the chain-limiting agent. According to some advantageous embodiments, the reaction solvent, the aromatic ether or mixture of aromatic ethers, the nucleating agent or mixture of nucleating agents, comprise in total less than 500 ppm by weight of water, to limit the hydrolysis reaction of the acyl chloride or mixture of acyl chlorides. The same preferred ranges of values ​​as for the reaction solvent apply mutatis mutandis.

[0129] To ensure the absence of water traces in a reactor, the process advantageously includes a preliminary drying step, i.e., reducing the water content of the reaction solvent and / or the monomer containing at least one aromatic ether group, and / or the nucleating agent, before contacting them with the monomer containing at least one acyl chloride group. Methods for implementing this preliminary drying step include, for example, distilling the chemical compounds, contacting them with a molecular sieve, or contacting them with a small amount of a dehydrating agent such as aluminum chloride.

[0130] The use of one or more chain-limiting agents in the reaction medium is optional. Their addition allows for better control of the degree of polymerization and therefore the viscosity of the polymer being produced. It also allows for better control of the polymer chain ends and, if necessary, ensures greater stability, particularly thermal stability, of the polymer. Two types of chain-limiting agents can be used: a nucleophilic chain-limiting agent or an electrophilic chain-limiting agent.

[0131] In some embodiments, the chain-limiting agent is a nucleophilic chain-limiting agent. The nucleophilic chain-limiting agent may, in particular, be chosen from compounds with the following chemical formula:

[0132] [Chem 5] in which:

[0133] Xi represents: a covalent bond, -O-, or -S-; and

[0134] X2 represents CeHsCO, or C6H5SO2; or the following chemical formula:

[0135] [Chem 6] in which:

[0136] X3 is a halogen, an alkyl group or an alkoxy group having 1 to 10 carbon atoms.

[0137] Preferably, the nucleophilic chain limiting agent is chosen from the group consisting of: 4-phenoxybenzophenone, 4-phenoxydiphenylsulfone, anisole, fluorobenzene, chlorobenzene, biphenyl, toluene, and mixtures thereof.

[0138] A particularly advantageous nucleophilic chain limiting agent is 4-phenoxybenzophenone.

[0139] In some embodiments, the chain-limiting agent is an electrophilic chain-limiting agent. The electrophilic chain-limiting agent may, in particular, be selected from compounds with the following formula:

[0140] [Chem 7]

[0141] [Chem 8] in which:

[0142] X represents: a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 10 carbon atoms, a nitro group, CeH5CO or C6H5SO2; or of the following formula:

[0143] [Chem 9]

[0144] [Chem 10]

[0145] (X), in which:

[0146] X n represents n groups, n being an integer chosen between 2 and 5, each group being independently chosen from: a halogen atom, an alkyl or alkoxy group having 1 to 10 carbon atoms, a nitro group, CeH5CO or C6H5SO2.

[0147] Preferably, the electrophilic chain limiting agent is chosen from the group consisting of: benzoyl chloride, acetyl chloride, 3,5-dichlorobenzoyl chloride, 3,5-difluorobenzoyl chloride, p-fluorobenzoyl chloride, p-chlorobenzoyl chloride, p-methoxybenzoyl chloride, benzene sulfonyl chloride, p-chlorobenzene sulfonyl chloride, p-methylbenzene sulfonyl chloride, 4-benzoylbenzoyl chloride, and mixtures thereof.

[0148] Advantageously, the chain-limiting agent is an electrophilic chain-limiting agent, selected from benzoyl chloride, p-fluorobenzoyl chloride, 3,5-difluorobenzoyl chloride, or a mixture thereof. These chain-limiting agents are easy to dose since they are liquid at room temperature, have a low production cost, and ensure good thermal stability of the polymer. In some embodiments, benzoyl chloride is used as the chain-limiting agent.

[0149] According to some embodiments, a chain-limiting agent, namely p-fluorobenzoyl chloride, is used.

[0150] According to some embodiments, a chain-limiting agent, namely 3,5-difluorobenzoyl chloride, is used.

[0151] In embodiments where a chain-limiting agent is used, the latter can be added at any stage of the process.

[0152] Since the polymerization reaction is a polycondensation, the monomer(s) containing at least one aromatic ether group is / are introduced into the reaction mixture under substantially stoichiometric conditions with respect to the monomer(s) containing at least one acyl chloride group. The molar proportion of monomer(s) containing at least one aromatic ether group relative to the monomer(s) containing at least one acyl chloride group that has been introduced in total into the reaction mixture formed is preferably from 0.9:1.1 to 1.1:0.9.According to advantageous embodiments, the monomer(s) comprising at least one aromatic ether function is / are introduced in excess relative to the monomer(s) comprising at least one acyl chloride function, preferably with a molar ratio of monomer(s) comprising at least one aromatic ether function relative to the monomer(s) comprising at least one acyl chloride function of 1.001 to 1.1. In these embodiments, if a chain-limiting agent is used, it is preferably an electrophilic chain-limiting agent, for example, and advantageously, benzoyl chloride or p-fluorobenzoyl chloride or 3,5-difluorobenzoyl chloride.

[0153] The molar proportion of Lewis acid relative to the monomer(s) comprising at least one aromatic ether function having been introduced in total into the reaction mixture formed is preferably such that the Lewis acid is in slight excess relative to the total of the ether and ketone functions of the monomer(s) comprising at least one aromatic ether function and of the monomer(s) comprising at least one acyl chloride function.The molar proportion of Lewis acid relative to the monomer(s) comprising at least one aromatic ether function introduced in total into the reaction mixture formed is preferably from 5.0 to 7.0, and very preferably from 5.1 to 6.5, in embodiments where the monomer(s) comprising at least one aromatic ether function is (are) essentially constituted, or constituted, of 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene, or a mixture thereof.

[0154] The molar proportion of monomer comprising at least one aromatic ether function relative to the reaction solvent(s) introduced in total into the reaction medium at the end of polymerization is preferably greater than or equal to 0.005, very preferably greater than or equal to 0.008, and more preferably greater than or equal to 0.010.

[0155] The molar proportion of monomer(s) comprising at least one aromatic ether function relative to the reaction solvent(s) introduced in total into the reaction medium at the end of polymerization is greater than or equal to 0.010, or greater than or equal to 0.011, or greater than or equal to 0.012, or greater than or equal to 0.013, or greater than or equal to 0.014, or greater than or equal to 0.015, or greater than or equal to 0.016, or greater than or equal to 0.17.Conversely, given that the less reaction solvent the reaction medium contains, the more likely it is to form fouling during polymerization, especially in the absence of a dispersing agent, the molar ratio of monomer(s) comprising at least one aromatic ether function to the total reaction solvent(s) introduced into the reaction medium at the end of polymerization is preferably less than or equal to 0.030, very preferably less than or equal to 0.025 and extremely preferably less than or equal to 0.022. Thus, according to certain embodiments, the molar ratio of monomer(s) comprising at least one aromatic ether function relative to the reaction solvent(s) introduced in total into the reaction medium at the end of polymerization is 0.005 to 0.030, preferably 0.008 to 0.025, and extremely preferably 0.010 to 0.022.

[0156] The mass proportion of nucleating agent(s) relative to the polymerization reagents is adjusted according to the desired proportion of nucleating agent(s) within the recovered polyaryletherketone composition. It is considered that the process according to the invention makes it possible to incorporate essentially all of the nucleating agent from the dispersion into the precipitating polyaryletherketone. In particular, the process according to the invention generally makes it possible to incorporate at least 90% by weight of the nucleating agent(s) dispersed in the reaction mixture into the precipitating polyaryletherketone. Advantageously, the process according to the invention makes it possible to incorporate at least 92.5%, or at least 95%, or at least 97.5% by weight of the nucleating agent(s) dispersed in the reaction mixture into the precipitating polyaryletherketone.Furthermore, the yield of polyaryletherketone recovered at the end of the process is generally greater than or equal to 0.85, preferably greater than or equal to 0.90, and even more preferably greater than or equal to 0.95.

[0157] The molar proportion of chain-limiting agent(s) relative to the monomer(s) comprising at least one aromatic ether function that has been introduced in total into the reaction medium at the end of polymerization can advantageously be from 0 to 0.12.

[0158] The process according to the invention comprises contacting polymerization reagents suitable for the manufacture of a polyaryletherketone, in all or part of the reaction solvent to form a reaction mixture and dispersing said at least one nucleating agent in said reaction mixture formed or in the process of being formed.

[0159] In the context of this invention, a "reaction mixture" is defined as the moment when all or part of the polymerization reactants have been brought into contact. For the electrophilic polymerization reaction, a "reaction mixture" is therefore defined as the presence of all or part of the monomer(s) containing at least one aromatic ether group, all or part of the monomer(s) containing at least one acyl chloride group, and all or part of the Lewis acid in at least a fraction of the reaction solvent. In other words, the "reaction mixture" begins to exist when precipitating polymerization can be initiated, that is, when all or part of the monomer(s) containing at least one aromatic ether group, all or part of the monomer(s) containing at least one acyl chloride group, and all or part of the Lewis acid in at least a fraction of the reaction solvent have been brought into contact.

[0160] The step of contacting the polymerization reagents ends when all of the monomer(s) containing at least one aromatic ether group, the monomer(s) containing at least one acyl chloride group, and the Lewis acid have been contacted. Thus, the reaction mixture formed comprises all of the monomer containing at least one aromatic ether group (for example, 1,4-bis(4-phenoxybenzoyl)benzene) or a mixture of several of these monomers, all of the monomer containing at least one acyl chloride group or a mixture of several of these monomers (for example, a mixture of isophthaloyl chloride and terephthaloyl chloride), all of the Lewis acid, and all or part of the reaction solvent.Conversely, the reaction mixture in formation refers to a mixture in which the monomer comprising at least one aromatic ether function or the mixture of several of these monomers has not yet been added or has not been added in full, or the monomer comprising at least one acyl chloride function or the mixture of several of these monomers has not yet been added or has not been added in full, or the Lewis acid has not yet been added or has not been added in full, in the reaction medium.

[0161] The process according to the invention comprises dispersing the nucleating agent in the reaction mixture being formed or in the reaction mixture formed.

[0162] In some advantageous embodiments, the nucleating agent can be added to the reaction mixture being formed or to the reaction mixture as a pre-dispersion in a fraction of the reaction solvent. Pre-dispersion is a preliminary step in which the particles are initially mixed to ensure uniform distribution before being fully dispersed. This facilitates the dispersion process by reducing particle agglomerations in the reaction mixture.

[0163] According to some advantageous embodiments, the nucleating agent can be dispersed in the reaction mixture being formed or in the reaction mixture formed or pre-dispersed to form a pre-dispersion, by high-pressure homogenization, and / or by high-shear mixing and / or by the use of ultrasound.

[0164] In some advantageous embodiments, the reaction mixture is maintained at a temperature T0 during the step of contacting the polymerization reagents, so that the polymerization reaction is essentially inhibited or at least remains extremely kinetically limited. The temperature T0 is generally below 25°C. In some embodiments, T0 is advantageously less than or equal to 15°C. More preferably, it is less than or equal to 10°C. In some embodiments, it may be less than or equal to 8°C, or less than or equal to 5°C, or less than or equal to 0°C, or even less than or equal to -5°C. In some embodiments, T oThe reaction mixture may be in the temperature range of -10°C to 15°C, and preferably from -5°C to 10°C. The reaction mixture formed may be held at temperature T0 for a certain period, for example, to ensure proper homogenization of the reaction medium. Preferably, the step of bringing the polymerization reagents into contact to form the reaction mixture, and optionally the step of holding the mixture at T0, are carried out under stirring. Preferably, the nucleating agent is dispersed in the reaction mixture formed or in the reaction mixture being formed at T0.

[0165] When it is stated that the contacting of the reactants to form the reaction mixture is carried out at To and / or that the reaction mixture formed is maintained at To, this does not imply that the temperature remains fixed, but means that the temperature of the reaction medium remains within the range of temperatures imposed for To.

[0166] The introduction of polymerization reagents, reaction solvent, dispersed nucleating agent, and, if applicable, chain-limiting agent into the reaction medium can theoretically be carried out in any order. However, certain embodiments are particularly advantageous, as described below.

[0167] The nucleating agent, preferably pre-dispersed, can be contacted with the monomer comprising at least one aromatic ether group in all or part of the reaction solvent to obtain a first mixture comprising the dispersed nucleating agent, the monomer comprising at least one aromatic ether group, and at least a fraction of the reaction solvent. This first mixture is then dried to remove and / or reduce its water content. The monomer comprising at least one acyl chloride group can then be added to the first dried mixture, yielding a second mixture.

[0168] Drying can be achieved by distillation, and / or inerting the reactor ceiling with nitrogen, and / or by adding a dehydrating agent, in particular aluminium chloride, in small quantities.

[0169] Lewis acid can be introduced at any time during the contact of the polymerization reagents. In some embodiments, it is added to the second mixture described above. Since the complexation of Lewis acid with acyl chloride is an exothermic reaction, the Lewis acid is added sufficiently slowly to the reactor. The Lewis acid addition step can last from 15 minutes to 12 hours. An optional homogenization step may be performed, if desired. This optional homogenization step can last 1 hour or less, and preferably 30 minutes or less.

[0170] According to specific embodiments, the following sequence can be implemented for the formation of the reaction mixture by contacting the polymerization reagents in at least a fraction of the reaction solvent and dispersing the nucleating agent in the reaction mixture being formed:

[0171] First, a first fraction of the reaction solvent (e.g., ortho-dichlorobenzene) is introduced into the reactor. Second, the monomer containing at least one aromatic ether group (e.g., 1,4-bis(4-phenoxybenzoylbenzene)) is added and dispersed within the reaction solvent in the reactor while stirring. Third, a pre-dispersion of the nucleating agent (e.g., carbon black, boron nitride, or talc) in a second fraction of the reaction solvent is added and dispersed in the reactor while stirring. Fourth, to ensure the absence of any traces of water in the reactor, distillation is carried out, followed by purging the reactor head with nitrogen. Alternatively, or in addition, a dehydrating agent, such as a small amount of aluminum chloride, may be added to remove any remaining traces of water.Fifth, the monomer containing at least one acyl chloride group (e.g., isophthaloyl chloride and terephthaloyl chloride) is introduced into the reactor while stirring. Sixth, the Lewis acid (e.g., aluminum trichloride) is introduced while stirring. Since the complexation of the Lewis acid with the acyl chloride(s) is an exothermic reaction, the Lewis acid is added to the reactor slowly enough to maintain the reaction mixture at a temperature T0 as defined previously.

[0172] The process according to the invention comprises the polymerization of the reaction mixture formed in which the nucleating agent has been dispersed, until the precipitation of the polyaryletherketone in the reaction solvent.

[0173] Polymerization is generally carried out at a temperature T p greater than or equal to 40 °C and less than or equal to 120 °C.

[0174] According to preferred embodiments, the polymerization is carried out at a temperature T p less than or equal to 110 °C, and preferably still at a temperature T p less than or equal to 100°C.

[0175] In certain embodiments, polymerization can be carried out primarily between 40°C and 100°C, specifically between 55°C and 95°C. Polymerization can also be carried out primarily between 55°C and 90°C, or between 55°C and 80°C, or between 55°C and 70°C, or between 65°C and 95°C, or between 70°C and 95°C, or between 75°C and 95°C. To reach these temperatures, the process may, in some embodiments, include a gradual heating step. In these embodiments, the gradual heating step can be carried out at an average heating rate selected from a range of 0.65°C / minute to 2.5°C / minute. Specifically, it can be carried out at an average heating rate ranging from 0.70°C / minute to 2.2°C / minute. This can be achieved through heating means integrated into the reactor, the addition of a fraction of the preheated reaction solvent, or a combination of these two means.

[0176] Alternatively, in order to reach these temperatures, the process may, according to certain embodiments, include a step of contacting the reaction mixture at T0 with a preheated fraction of the reaction solvent so as to very rapidly reach a temperature in the aforementioned range of temperatures T0 p .

[0177] In advantageous embodiments, the hydrogen chloride produced during the polymerization reaction is extracted from the reactor during polymerization so as to promote the polymerization reaction. To this end, all or part of the polymerization may be carried out under reduced pressure, at an absolute pressure less than or equal to 900 mbar, or less than or equal to 800 mbar, or less than or equal to 700 mbar, or less than or equal to 600 mbar, or less than or equal to 500 mbar, or less than or equal to 400 mbar, or less than or equal to 300 mbar, or less than or equal to 200 mbar, or less than or equal to 100 mbar. Alternatively, or in addition, bubbling of an inert gas, for example helium, argon, or nitrogen, is carried out in the reaction mixture.This method is not preferred, however, as it creates additional turbulence in the reaction mixture and makes temperature control within the reactor more difficult to achieve.

[0178] The process can be carried out in a single reactor or a series of reactors. Reactors preferably have internal temperature control and measurement capabilities. Specifically, reactors may include one or more internal temperature sensors and be configured to cool and / or heat the medium they contain.

[0179] The reactors that can be used to implement the present invention are preferably equipped with an agitation device such as a mechanical agitator (which may, for example, include one or more agitators) or a recirculation loop with a pump.

[0180] After the polymerization reaction has been completed to the desired degree of polymerization, the process of the invention may include purifying the mixture of products containing the polyaryletherketone incorporating said at least one nucleating agent, in a manner known per se. This has, for example, already been described in document EP3655458.

[0181] This purification process allows in particular the separation of the reaction solvent, the catalyst, the unreacted reactants, as well as any possible reaction by-products of the polymer itself.

[0182] In particular, the purification process generally includes a step of contacting the mixture of products with a protic solvent to recover a first phase comprising the Lewis acid and a second phase comprising the polyaryletherketone. The protic solvent can be an aqueous solution. The aqueous solution can be simply water. Alternatively, the aqueous solution can be an acidic solution, such as hydrochloric acid. Preferably, the pH of the aqueous solution is not greater than 3, or not greater than 2. The dissociation of the polyetherketone-ketone-Lewis acid complex is more efficient when an acidic solution is used.

[0183] Solvent mixtures can also be used, such as an aqueous-organic solvent, for example an aqueous solution mixed with methanol, ethanol, isopropanol, or acetic acid. Preferably, a mixture of an aqueous solution and an alcohol, in particular methanol, ethanol, or isopropanol, comprising 95 to 60% by weight, preferably 80 to 95% by weight, of alcohol, is used.

[0184] Contacting the mixture of products with the protic solvent yields a first phase (containing the protic solvent) and a second phase (containing the reaction solvent). The Lewis acid is primarily present in dissolved form in the first phase, while the polyaryletherketone incorporating at least one nucleating agent is primarily present as a precipitate in the second phase. The polyaryletherketone incorporating at least one nucleating agent can then be recovered by solid / liquid separation of the second phase. Advantageously, the solid / liquid separation is carried out by centrifugal filtration.

[0185] The dry solids content of crude polyaryletherketone product at the end of the solid / liquid separation step is preferably between 10% by weight and 90% by weight, preferably still between 15% and 75% by weight and even more preferably between 20% and 50% by weight.

[0186] The liquid effluents, containing the first and second phases, can optionally be separated for separate recovery, preferably by settling, for possible reuse. A surfactant can be added to facilitate phase separation. When the Lewis acid is aluminum trichloride, the first phase advantageously contains it in proportions suitable for direct recycling through use in a water treatment / sludge flocculation process.

[0187] According to preferred embodiments, the crude polyaryletherketone product at the end of the previous solid / liquid separation step can be further purified by washing with one or more practical solvents.

[0188] The practical solvent at this stage is preferably water or an aqueous solution. However, in other variations, the practical solvent at this stage can also be an organic solvent, possibly mixed with water. Linear or branched aliphatic alcohols such as methanol, ethanol, and isopropanol are particularly preferred organic solvents. These organic solvents can optionally be mixed with each other and / or with water.

[0189] After the washing step or concurrently with the washing step, another solid / liquid separation step can be carried out.

[0190] According to an advantageous embodiment, a centrifugal filtration device is used, so that washing and solid / liquid separation can be carried out simultaneously in the device, without resuspension of the product.

[0191] After the final solid / liquid separation, the recovered solid is advantageously dried.

[0192] The drying step can be carried out conventionally, for example at a temperature ranging from 100°C to 280°C, and under atmospheric pressure or, preferably, under reduced pressure, for example at 30 mbar. After drying, the polyether-ketone-ketone generally has a reaction solvent content of less than or equal to 50 ppm, preferably less than or equal to 30 ppm, and even more preferably less than or equal to 15 ppm by weight, relative to the weight of polymer.

[0193] The polymer, which can be manufactured according to the process of the invention, generally has an inherent viscosity, measured at a concentration of 0.0005 g / mL in a 96.00% (mass fraction) sulfuric acid solution at 25°C using a suspended level Ubbelohde type viscometer (inner diameter of the capillary of 1.03 mm) according to ISO 307-2009 as applied to polyaryletherketones, of 0.4 to 2.0 dL / g, and preferably of 0.75 to 1.45 dL / g.

[0194] According to some embodiments, polyaryletherketone has an inherent viscosity of 0.75 to 0.85 dL / g, or 0.85 to 0.95 dL / g, or 0.95 to 1.05 dL / g, or 1.05 dL / g to 1.15 dL / g, or 1.15 to 1.25 dL / g, or 1.25 to 1.35 dL / g, or 1.35 to 1.45 dL / g.

[0195] The process according to the invention makes it possible to obtain a composition C comprising a polyaryletherketone (precipitant) and at least one nucleating agent, said at least one nucleating agent being incorporated into a polyaryletherketone matrix in the form of coarse particles of more or less homogeneous size. The powder has a packed density greater than or equal to 150 kg / m³ 3 and less than or equal to 500 kg / m 3 Advantageously, the powder can, in particular, have a packed density greater than or equal to 180 kg / m³. 3 and less than or equal to 350 kg / m 3 .

[0196] Such polyaryletherketone-based particles can be ground at room temperature in a manner known per se. The invention therefore also relates to fine powders of composition C having various particle size distributions, suitable for various applications.

[0197] According to some embodiments, the fine powder may have a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 500 pm.

[0198] According to some embodiments, the fine powder may have a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 300 pm.

[0199] According to some embodiments, the fine powder may have a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 150 pm.

[0200] According to some embodiments, the fine powder may have a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 30 microns.

[0201] According to some embodiments, the powder is characterized in that its elastic modulus in tension at 23°C is from 3.5 GPa to 5.5 GPa, and preferably from 3.8 GPa to 5.0 GPa, as measured on a type 1 BA test specimen manufactured by injection, with a through-feed speed of 1 mm / min, according to ISO 527-2: 2012.

[0202] The type 1 BA test specimen is preferably manufactured by injection with a feed temperature of 320°C, a screw outlet temperature of 340°C, a mold temperature of 80°C and a cycle time of no more than 1 minute.

[0203] Examples

[0204] Nucleating agents

[0205] The nucleating agents used to implement the examples were as follows: NC: Ketjenblack EC-600JD carbon black, marketed by the company

[0206] Nouryon. This carbon black has aggregates with a size of approximately 0.1 µm to 1 µm. It also has a specific surface area of ​​1400 m². 2 / g.

[0207] Silica: Hydrophilic fumed silica Aerosil R150, marketed by Evonik. This silica has aggregates with a size of approximately 0.1 µm. It has a BET of 135–165 m 2 / g.

[0208] Talc: Jetfine® 0.7C talc, marketed by Imerys. This talc has a particle size distribution such that dso = 2.5 pm. NB: Boron nitride AC6111, marketed by Momentive. This boron nitride is hexagonal and turbostratified. It has a particle size distribution such that dso = 0.5 pm. It also has a BET specific surface area of ​​40 m². 2 / g.

[0209] Production of PEKK particles (T / l: 60 / 40) incorporating or not a nucleating agent

[0210] A double-jacketed reactor (R) equipped with an agitation and inerting system under a nitrogen flow in the sky, was used.

[0211] Ortho-dichlorobenzene and 1,4-bis(4-phenoxybenzoyl)benzene were first added under stirring to reactor R in a mass proportion 1,4-bis(4-phenoxybenzoyl)benzene / ortho-dichlorobenzene equal to 0.13.

[0212] A pre-dispersion of nucleating agent (silica for sample #2; talc for sample #3; carbon black for samples #4-#5; boron nitride for samples #7-#8) in a fraction of the ortho-dichlorobenzene used for polymerization was prepared in a reactor (R1) by dispersing the nucleating agent for 30 minutes under ultrasound. The nucleating agent pre-dispersion was added in reactor R to the ortho-dichlorobenzene Z1,4-bis(4-phenoxybenzoyl)benzene mixture, in an amount adjusted to obtain the desired final concentration, with almost all of the nucleating agent being trapped by the polymer precipitate.

[0213] No nucleating agent was used to implement a control (comparative sample #1).

[0214] Dynamic vacuum distillation (90°C, 150 mbar) and nitrogen inerting were then implemented in reactor R to eliminate any trace of residual water in the reactor.

[0215] A mixture of terephthaloyl and isophthaloyl chlorides, in a terephthaloyl chloride to isophthaloyl chloride molar ratio of 0.23, was then added to reactor R, with stirring, so as to be in a substantially equimolar quantity, but slightly deficient with respect to the 1,4-bis(4-phenoxybenzoyl)benzene introduced into the reactor. The molar ratio of 1,4-bis(4-phenoxybenzoyl)benzene to the terephthaloyl and isophthaloyl chloride mixture was 1.04. Benzoyl chloride was also added with stirring, used as a chain limiter, in a molar ratio to 1,4-bis(4-phenoxybenzoyl)benzene of 0.048.

[0216] The reaction medium in reactor R was then cooled to -5°C. Solid aluminum trichloride was slowly added to reactor R under stirring to form a reaction mixture, with the temperature of the reaction mixture maintained close to -5°C throughout the addition step. The molar ratio of aluminum trichloride to 1,4-bis(4-phenoxybenzoyl)benzene introduced into the reactor was 6.3.

[0217] Once all the aluminum trichloride had been added, ortho-dichlorobenzene was added to the reaction mixture to obtain a final mass ratio of 1,4-bis(4-phenoxybenzoyl)benzene / ortho-dichlorobenzene of 0.039. The temperature in reactor R was gradually increased at a rate of 1.8°C / min until the reaction mixture reached a temperature of 90°C. The reaction mixture was then maintained at 90°C for 30 minutes.

[0218] The product mixture obtained after maintaining the reaction mixture at 90°C for 30 minutes was then cooled to a temperature of 50°C or lower. It was purified by mixing with an aqueous hydrochloric acid solution having a pH < 3 and separating the solid / liquid using a filter. It was then washed three times by resuspension followed by filtration, the washing solutions used successively being methanol, hydrochloric acid, and water. Finally, it was dried for 48 hours at 180°C under vacuum (30 mbar), and a coarse PEKK powder, possibly incorporating a nucleating agent, was recovered.

[0219] The coarse powders obtained, with or without a nucleating agent, all had a similar inherent viscosity, between 0.97 dL / g and 1.05 dL / g, and a similar packed density, between 190 and 210 kg / m³. 3 .

[0220] The isothermal half-crystallization times (ti / 2) at Tme Temperatures of 240°C were measured for the different samples #1-#5 and are presented in Table 1 below. The mass proportion of nucleating agent corresponds to the weight of nucleating agent incorporated relative to the total weight of polymer.

[0221] [Table 1]

[0222] It is observed that the nucleating agents incorporated according to the process of the invention all have a nucleating effect, since the crystallization time of samples #2-#5 is shorter, even significantly shorter, than that of sample #1 (control). At equal mass proportions, carbon black is the nucleating agent that most accelerated crystallization (lowest ti / 2 among samples #2-#4). Thus, adjusting the proportion of carbon black can allow for significant modulation of the polymer crystallization rate, even at very low concentrations (samples #4-#5).

[0223] Two other samples were prepared to incorporate boron nitride into polyetheretherketone. Sample #7 incorporated 0.5% by weight of boron nitride relative to the weight of polyetheretherketoneketone. Sample #8 incorporated 1.0% by weight of boron nitride relative to the weight of polyetheretherketoneketone.

[0224] Comparison with powders according to WO2021069833

[0225] For comparison, the powders obtained according to examples 3 and 4 of WO2021069833 (considered here as comparative examples) have the following characteristics. These powders consist of a polyetherketone-ketone and talc incorporated into the polyetherketone-ketone, with the talc representing 30% by weight relative to the composition weight. The polyetherketone-ketone has a mass proportion of T motifs relative to the sum of T and I motifs of 60% and a viscosity index of 0.75 dl / g at 25°C in a 96% by mass aqueous sulfuric acid solution, according to ISO 307:2019.

[0226] The talc according to Example 3 of WO2021069833 is Jetfine® 0.7C, the same as that used for the implementation of Sample #3 in the present invention. The resulting powder has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, with a median diameter D50 of 120 microns. The tensile elastic modulus at 23°C on type 1 BA specimens, according to ISO 527-2:2012, manufactured by injection molding at a through-feed speed of 1 mm / min using an MTS 810® machine, marketed by MTS Systems Corporation, equipped with a mechanical extensometer, is 9 GPa.

[0227] The packed density of this powder was measured here and is 640 kg / m³ 3 .

[0228] The talc according to example 4 of WO2021069833 is Steaplus® HAR T77. The resulting powder has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, having a median diameter D50 equal to 110 microns.

[0229] The elastic modulus in tension at 23°C on type 1 BA test specimens, according to ISO 527-2: 2012, manufactured by injection, with a cross speed of 1 mm / min, using an MTS 810® device, marketed by MTS Systems Corporation, equipped with a mechanical extensometer, is 9 GPa.

[0230] The packed density of this powder was measured here and is 625 kg / m³ 3 .

[0231] The tensile modulus of elastic material at 23°C for type 1 BA specimens, according to ISO 527-2:2012, made of talc-free PEKK, with a through-feed speed of 1 mm / min, using an MTS 810® apparatus marketed by MTS Systems Corporation, is 4 GPa (example 7 of WO2021069833). The lesson of WO2021069833 is therefore a significant increase in the tensile modulus of elastic material due to the addition of a substantial amount of filler. It is precisely this modification of the mechanical properties that allows the more brittle granules to be ground.

[0232] Fabrication of PEKK granules incorporating carbon black (sample #6) or boron nitride (sample #9)

[0233] PEKK granules incorporating 1% by weight of carbon black were produced by compounding (sample #6). Coarse PEKK powder without a nucleating agent (sample #1) was mixed with carbon black by dry mixing. This mixture was then extruded on a laboratory DSM micro-extruder (temperature of 350°C, screw speed of 100 rpm, recirculation time of 2 min to ensure good PEKK / nucleating agent mixing).

[0234] PEKK granules incorporating 1 wt% boron nitride were produced by compounding (sample #9). Coarse PEKK powder without a nucleating agent (sample #1) was mixed with boron nitride by dry mixing. This mixture was then extruded on a laboratory DSM micro-extruder (temperature of 350°C, screw speed of 100 rpm, recirculation time of 2 min to ensure good PEKK / nucleating agent mixing).Since the isothermal half-crystallization time at 240°C for sample #4 was measured to be strictly less than 1 minute, it was decided to increase the measurement temperature of the half-crystallization times in order to be able to compare finely any possible differences between PEKK granules incorporating 1.0% by weight of nucleating agent (comparative samples #6 and #9) and coarse PEKK powders having up to 1.0% by weight of nucleating agent (samples #4-#5 and #7-#8 according to the invention).

[0235] Table 2 shows the isothermal half-crystallization times at a measurement temperature of 270°C or 280°C.

[0236] [Table 2] In light of these results, it can be seen that the process according to the invention has made it possible to incorporate the nucleating agent in such a way that the effect of the nucleating agent on the crystallization rate is similar to, or even better than, when the nucleating agent is incorporated by compounding (see #5 with regard to #6 at 270°C and 280°C and #8 with regard to #9 measured only at 280°C). Furthermore, it is not possible to transform the granules containing a low concentration of nucleating agent (#6 or #9) into a fine powder by grinding, either at room temperature or under cryogenic conditions, unlike the coarse powders according to the invention (samples #4-#5 and #7-#8 according to the invention), which can be ground at room temperature.The elastic modulus in tension at 23°C of type 1 BA specimens, according to ISO 527-2: 2012, of a PEKK composition incorporating a nucleant according to the process of the invention, with a traverse speed of 1 mm / min, using an MTS 810® apparatus, marketed by MTS Systems Corporation, is 4 GPa and is substantially unchanged compared to the elastic modulus of a PEKK composition without the nucleant.

Claims

DEMANDS 1. A process for manufacturing a composition comprising a polyaryletherketone incorporating at least one nucleating agent, the process comprising: the formation of a reaction mixture by contacting polymerization reagents suitable for the manufacture of a polyaryletherketone, in all or part of a reaction solvent; the dispersion of said at least one nucleating agent in said reaction mixture formed or in said reaction mixture during formation; the polymerization of the reaction mixture formed in which said at least one nucleating agent has been dispersed, until precipitation of the polyaryletherketone in said reaction solvent; the recovery of the composition comprising the polyaryletherketone incorporating said at least one nucleating agent.

2. A method according to claim 1 wherein said at least one nucleating agent is selected from: carbon-based compounds, in particular carbon black, graphite, graphene, carbon fibers, carbon nanotubes, and graphene oxide; nitrides, in particular boron nitride; oxides, in particular aluminum oxide, aluminum titanium oxide, magnesium oxide, zinc oxide, graphene oxide, or antimony trioxide; silicas; silicates, in particular talc, sodium silicate, aluminum silicate, calcium silicate, or magnesium silicate; and mixtures thereof.

3. A method according to any one of claims 1 and 2, wherein said at least one nucleating agent is a carbon-based compound selected from the list consisting of: carbon black, carbon nanotube, graphene, and mixtures thereof.

4. A method according to claim 3, wherein said at least one nucleating agent has a specific surface area BET greater than or equal to 200 m² 2 / g.

5. A method according to any one of claims 1 to 4, wherein said at least one nucleating agent is a boron nitride.

6. A method according to claim 5, wherein boron nitride has a hexagonal crystalline structure.

7. A process according to any one of claims 5 and 6, wherein the boron nitride has a specific surface area greater than or equal to 20 m² 2 / g.

8. A method according to any one of claims 1 to 7, wherein said at least one nucleating agent is a talc.

9. A method according to any one of claims 1 to 8, wherein said at least one nucleating agent has a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter d50 is such that d50 < 20 pm, preferably such that d50 < 10 pm and preferably further such that d50 < 5 pm.

10. A process according to any one of claims 1 to 9, wherein said at least one nucleating agent of the recovered composition represents from 0.1% to 5.0%, preferably from 0.2% to 3.0% by weight, relative to the weight of said at least one polyaryletherketone of the recovered composition.

11. A process according to any one of claims 1 to 10, wherein said at least one nucleating agent of the recovered composition represents from 0.25% to 2.5% by weight, relative to the weight of said at least one polyaryletherketone of the recovered composition.

12. A process according to any one of claims 1 to 11, wherein at least 90% by weight of the nucleating agent dispersed in the reaction mixture is incorporated into the polyaryletherketone of the recovered composition.

13. A process according to any one of claims 1 to 12, wherein said polymerization reagents suitable for the manufacture of polyaryletherketone comprise: at least one monomer comprising an ether function aromatic, at least one monomer comprising an acyl chloride function and a Lewis acid.

14. A process according to claim 13, wherein said at least one monomer comprising an aromatic ether function is diphenyl ether, 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or a mixture thereof, and preferably is 1,4-bis(4-phenoxybenzoyl)benzene.

15. A method according to any one of claims 13 and 14, wherein said at least one monomer comprising an acyl chloride function is terephthaloyl chloride, isophthaloyl chloride, or a mixture thereof.

16. A process according to any one of claims 13 to 15, wherein the Lewis acid is aluminum trichloride.

17. A process according to any one of claims 13 to 16, wherein said reaction solvent is selected from the group consisting of: dichloromethane, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, ortho-difluorobenzene, 1,2-dichloroethane, 1,1-dichloroethane, 1,1,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene, and mixtures thereof, preferably from the group consisting of: ortho-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, and mixtures thereof, and more preferably is ortho-dichlorobenzene.

18. A process according to any one of claims 13 to 17, wherein the formation of the reaction mixture and the dispersion of said at least one nucleating agent comprises: contacting said at least one monomer comprising an aromatic ether function with said at least one nucleating agent in all or part of the reaction solvent to obtain a first mixture; drying the first mixture; and adding said at least one monomer comprising an acyl chloride function to said first mixture to obtain a second mixture.

19. A process according to any one of claims 13 to 18, wherein the formation of the reaction mixture comprises the addition of the Lewis acid after the addition of said at least one acyl chloride.

20. A process according to any one of claims 1 to 19, wherein the dispersion of said at least one nucleating agent in said reaction mixture being formed or in said reaction mixture formed, comprises the addition of a pre-dispersion of said at least one nucleating agent in a fraction of reaction solvent to the reaction mixture being formed or to the reaction mixture formed.

21. A process according to any one of claims 1 to 20, wherein the recovered composition comprising the polyaryletherketone incorporating said at least one nucleating agent is transformed into a powder having a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 500 pm, in particular by a comminution step.

22. Powder comprising particles comprising at least one polyaryletherketone and at least one nucleating agent, said at least one nucleating agent being incorporated within said at least one polyaryletherketone, said powder having a packed density greater than or equal to 150 kg / m³ 3 and less than or equal to 500 kg / m 3 .

23. Powder according to claim 22, having a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 500 pm, and preferably such that D50 < 300 pm.

24. Powder according to claim 22, having a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 150 pm.

25. Powder according to claim 22, having a volume-weighted particle size distribution, measured by laser diffraction, according to ISO 13320:2009, such that the median diameter D50 is such that D50 < 30 pm.

26. Powder according to any one of claims 22 to 25, characterized in that said at least one nucleating agent represents from 0.1% to 5.0%, preferably from 0.2% to 3.0% by weight, relative to the weight of said at least one polyaryletherketone.

27. Powder according to any one of claims 22 to 26, capable of being obtained by a process according to any one of claims 1 to 21.

28. Powder according to any one of claims 22 to 27, characterized in that its elastic modulus in tension at 23°C is from 3.5 GPa to 5.5 GPa, and preferably from 3.8 GPa to 5.0 GPa, as measured on a type 1 BA test specimen manufactured by injection, with a through-feed speed of 1 mm / min, according to ISO 527-2: 2012.

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