Process for the manufacture of polyetherketoneketones

Abstract

This invention relates to a method for manufacturing polyetherketoneketone, comprising contacting an aromatic ether (which is a diphenyl ether, 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or a mixture thereof), an acyl chloride (which isophthaloyl chloride, terephthaloyl chloride or a mixture thereof), a Lewis acid and a first portion s1 of a reaction solvent at a temperature T0 less than or equal to 25°C to form a premix, and contacting the premix formed at T0 with a portion s2 of the reaction solvent (the portion s2 of the reaction solvent is preheated) to form a reaction mixture reaching a temperature T1.

Description

Technical Field

[0001] This invention relates to the field of polyetherketoneketone.

[0002] More specifically, the present invention relates to a method for producing polyetherketone ketones by electrophilic precipitation polymerization.

[0003] The present invention also relates to polymers that can be obtained by the method, particularly in the form of porous sheet (flake, scaly) powder. Background Technology

[0004] Known practices (particularly from US 3,791,890) involve the electrophilic production of polyetherketones by reacting a mixture of isophthaloyl chloride and terephthaloyl chloride (acyl chloride) with diphenyl ether (aromatic ether) in the presence of aluminum chloride (Lewis acid) using o-dichlorobenzene as the reaction solvent. Example 3 of US 3,791,890 describes the preparation of a premix comprising acyl chloride, diphenyl ether, and aluminum chloride in a first portion of o-dichlorobenzene at a temperature of about -5°C. The reaction is then initiated by dispersing this premix in a second portion of o-dichlorobenzene preheated to 100°C. This sequence of first preparing a cold premix and then dispersing it in a preheated reaction solvent allows for an extremely rapid increase in the temperature of the reaction mixture. Although the mechanism occurring in the reaction medium is not fully understood, US 3,791,890 suggests that this is believed to enable the separation of the formed polymer particles, promote the polymerization reaction, and prevent the particles from agglomerating into the gel-like substance characteristic of this polymerization reaction.

[0005] As shown in the experimental section, polymers obtained by methods according to this prior art (where the premix is ​​dispersed in a reaction solvent characterized in this invention at a high, preferably at least about 100°C) have several drawbacks. First, chromatographic analysis of such polymers in the prior art shows that they include perceptible amounts of low molecular weight oligomers, particularly those with molecular weights of 500 g / mol to 3000 g / mol. However, these low molecular weight oligomers can negatively affect the processing and / or some thermal properties of the polymer. For example, the presence of low molecular weight oligomers can be a cause of defects (particularly black spots) on objects obtained by extrusion. Furthermore, deposits of degradable material can form in the die used for extrusion. Moreover, these low molecular weight oligomers (particularly those with molecular weights of 500 g / mol to 3000 g / mol) are difficult to extract even by advanced extraction methods.

[0006] Secondly, such polymers are in the form of large particles with a rather uneven size distribution, which is detrimental to many applications where the powder must be able to flow easily and the particles must exhibit uniformity.

[0007] Alternative methods for avoiding the formation of gel-like substances during polymerization are also known from WO 9 523 821. According to this method, polymer dispersants can be used to prevent the agglomeration of viscous polymer products formed during polymerization. The document explains that the viscous polymer products are actually due to complexes formed at the beginning of the polymerization reaction by a low molecular weight polymer and a Lewis acid, which precipitate as a gel covering the walls of the reactor and agitator. In dispersants, the patent specifies, for example, compounds having portions of the following formula as side groups:

[0008] [Chemical Formula 1]

[0009] .

[0010] Another known practice (particularly from US 2012 / 0263953) is the use of control agents as dispersants, and in particular the use of benzoic acid and its derivatives.

[0011] However, adding dispersants has several disadvantages. The use of some dispersants (particularly those having the portion of formula (0) shown above) leads to excessive consumption of Lewis acids in the process, which also form complexes with the dispersant. Furthermore, this complicates the management of process effluents, particularly the utilization / recycling of effluents containing Lewis acids. Finally, dispersants cannot be completely removed from the manufactured polymer and can have detrimental effects on the polymer's thermal stability.

[0012] Therefore, there is a need to improve existing methods for polyetherketoneketone to reduce the amount of low molecular weight molecules in the polymer and / or obtain powder with a more uniform distribution, while continuing to limit the agglomeration of polymer particles into the gel-like substance characteristic of the electrophilic polymerization reaction of polyetherketoneketone.

[0013] Purpose of the invention

[0014] One object of the present invention is to provide a simple method for manufacturing polyetherketoneketone, which enables the limitation of scaling in polymerization reactors.

[0015] At least according to some embodiments, another objective is to provide a method with good polymer manufacturing yield.

[0016] According to at least some embodiments, another object of the present invention is to provide a method for manufacturing polymers having fewer low molecular weight molecules / oligomers than the polymers of the prior art described above, particularly fewer molecules / oligomers having a molecular weight of less than 3000 g / mol, and more specifically fewer molecules / oligomers having a molecular weight in the range of 500 g / mol to 3000 g / mol.

[0017] According to at least some embodiments, another object of the present invention is to provide a method for obtaining polymer particles having a sufficiently uniform size distribution.

[0018] According to at least some embodiments, another object of the present invention is to provide a method for obtaining polymer particles of sufficiently small size.

[0019] According to at least some embodiments, another object of the present invention is to provide a method for obtaining polymer particles that do not contain dispersants, or even contain trace amounts of dispersants.

[0020] Another object of the present invention is to provide polymers, particularly in powder form, which are easier to process and / or enable the manufacture of parts with fewer defects (particularly for objects obtained by extrusion methods). Summary of the Invention

[0021] This invention relates to a method for manufacturing polyetherketoneketone. The method involves:

[0022] -The aromatic ether, acyl chloride, Lewis acid and the first portion s1 (the first fraction s1 of the reaction solvent) of the reaction solvent are brought together at a temperature T0 less than or equal to 25°C to form a premix, wherein the aromatic ether is diphenyl ether, 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or a mixture thereof, and the acyl chloride is isophthaloyl chloride, terephthaloyl chloride or a mixture thereof;

[0023] - The premix formed at T0 is brought into contact with a portion s2 (fraction s2 of the reaction solvent) of the reaction solvent to form a reaction mixture reaching a temperature T1 ranging from 40°C to 80°C, wherein the portion s2 of the reaction solvent is preheated.

[0024] Optionally, the method includes maintaining the formed premix at T0 before forming the reaction mixture reaching T1.

[0025] Optionally, the method includes holding the formed reaction mixture at T1.

[0026] According to some embodiments, the reaction solvent is selected from o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene, and mixtures thereof. Preferably, the reaction solvent is o-dichlorobenzene.

[0027] According to some embodiments, the Lewis acid is selected from: aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, tin chloride, titanium tetrachloride, and molybdenum pentachloride, and mixtures thereof. Preferably, the Lewis acid is aluminum trichloride.

[0028] Preferably, the aromatic ether is essentially composed of 1,4-bis(4-phenoxybenzoyl)benzene or 1,4-bis(4-phenoxybenzoyl)benzene.

[0029] According to some implementations, s2 ≥ 0.25. According to some implementations, s1 ≥ 0.25.

[0030] According to some implementations, s1≥0.25 and s2≥0.25.

[0031] According to some implementation methods, s1+s2≥0.75.

[0032] According to some implementation methods, s1+s2=1.

[0033] According to some implementations, T1 ranges from 40°C to 52°C, or from 52°C to 60°C, or from 60°C to 68°C, or from 68°C to 80°C.

[0034] According to some embodiments, the reaction mixture is brought to T1 and optionally held at T1 until the resulting reaction mixture has a fraction of less than or equal to 50%, preferably less than or equal to 25%, and more preferably less than or equal to 15% of a molecular mass (molecular substance) strictly less than 500 g / mol in PMMA equivalent.

[0035] According to some embodiments, after the step of forming a reaction mixture at temperature T1 and optionally maintaining it at temperature T1, the reaction medium is brought to a temperature T2 ranging from a temperature at least 10°C higher than T1 to 120°C and optionally maintained at temperature T2.

[0036] According to some embodiments, the method includes a step for purifying the product mixture obtained at the end of polymerization.

[0037] According to some embodiments, a chain restrictor (chain limiter) is added before the step of forming the reaction mixture that reaches temperature T1.

[0038] According to some embodiments, the molar ratio of the aromatic ether to the reaction solvent that has been introduced into the reaction mixture is 0.005 to 0.030, preferably 0.008 to 0.025, and very preferably 0.010 to 0.022.

[0039] According to some embodiments, the premix formed at T0 is dispersed in all or part of the portion s2 of the preheated reaction solvent to form a reaction mixture reaching T1.

[0040] According to some embodiments, the step of contacting the premix with the preheated reaction solvent portion s2 to form a reaction mixture reaching T1 is carried out under stirring, and preferably using a dual-flow stirring device.

[0041] According to some embodiments, the polyetherketone ketone obtained by the method is composed of repeating units of formula (I) and formula (II), wherein the ratio of units of formula (II) to units of formula (I) is 55:45 to 95:5.

[0042] The unit of formula (I) has the following chemical formula:

[0043] [Chemical Formula 2]

[0044] (I),

[0045] The unit of formula (II) has the following chemical formula:

[0046] [Chemical Formula 3]

[0047] (II).

[0048] The present invention also relates to polyetherketones derived therefrom, particularly in powder form. These polyetherketones are advantageously obtained by an electrophilic method according to the invention.

[0049] The polyether ketone consists of three molecular weight fractions A, B, and C, where A represents the percentage of molecular weight strictly below 500 g / mol in PMMA equivalent, B represents the percentage of molecular weight from 500 g / mol to 3000 g / mol in PMMA equivalent, and C represents the percentage of molecular weight strictly above 3000 g / mol in PMMA equivalent. Its characteristics are:

[0050] A+B≤5.0% and A+B+C=100%.

[0051] According to some implementation methods, B ≤ 4.0%, preferably B ≤ 3.5%, and more preferably B ≤ 3.3%.

[0052] According to some embodiments, polyetherketoneketone has an intrinsic viscosity of greater than or equal to 0.4 dl / g, preferably greater than or equal to 0.5 dl / g, more preferably greater than or equal to 0.6 dl / g, and more preferably greater than or equal to 0.7 dl / g. According to some embodiments, polyetherketoneketone has an intrinsic viscosity of less than or equal to 2 dl / g and preferably less than or equal to 1.5 dl / g.

[0053] According to some embodiments, polyetherketoneketone is composed of repeating units of formula (I) and formula (II), wherein the ratio of units of formula (II) to units of formula (I) is 55:45 to 95:5.

[0054] According to some implementation methods, polyetherketoneketone does not contain any dispersant.

[0055] According to some embodiments, such as those obtained by sieving using a sieve with a mesh size equal to 1 mm, the polyetherketone powder has a mass ratio of less than or equal to 50% of particles with a size strictly greater than 1000 micrometers.

[0056] According to some embodiments, the powder has a mass proportion of particles with a size strictly greater than 1000 micrometers of less than or equal to 10%, and preferably less than or equal to 5%. According to a first variation, the mass proportion of particles with a size ranging from 315 micrometers to 1000 micrometers is greater than or equal to 50%, and preferably greater than or equal to 80%. According to this first variation, the powder preferably has a mass proportion of particles with a size strictly less than 315 micrometers of less than 10%. According to a second variation, the mass proportion of particles strictly less than 630 micrometers is greater than or equal to 50%, preferably greater than or equal to 70%, and more preferably greater than or equal to 85%.

[0057] According to some embodiments, the powder has a density greater than or equal to 180 kg / m³. 3 And less than or equal to 400 kg / m 3 The tap density. Attached Figure Description

[0058] [ Figure 1 [] indicates the mass ratio (x-axis, in millimeters) of tests (experiments) #1 (55°C), #2 (65°C), and #3 (90°C; comparison) according to Example 1 for different particle size ranges (y-axis, in percentage) measured using a sieve.

[0059] [ Figure 2 [] represents the portion A (y-axis, %) of the product mixture obtained at different polymerization holding times (x-axis, in minutes) at 65°C after forming the reaction mixture according to Example 2, where the molecular weight is strictly less than 500 g / mol. Detailed Implementation

[0060] The polyether ketone ketone (also known as PEKK) prepared according to the method of the present invention has essentially the following composition, preferably the following composition:

[0061] [Chemical Formula 4]

[0062] (I),

[0063] It is also represented as isophthalic acid unit or by the first letter "I";

[0064] [Chemical Formula 5]

[0065] (II),

[0066] It can also be represented as a terephthalic acid unit or by the initial letter "T"; and,

[0067] Its mixture.

[0068] According to some embodiments, the polyether ketone ketone manufactured according to the present invention is substantially composed of (i.e., includes) at least 95 mol%, preferably at least 98 mol%, of repeating units of formula (I) and / or formula (II) relative to the total number of repeating units of the polymer, optionally taken as a whole.

[0069] According to some embodiments, the polyetherketoneketone manufactured according to the present invention is substantially composed of repeating units of formula (II) and optionally repeating units of formula (I), or is composed of repeating units of formula (II) and optionally repeating units of formula (I), wherein the ratio of units of formula (II) to units of formula (I) (denoted as ratio T:I) is 50:50 to 100:0. The ratio T:I may particularly be 50:50 to 55:45, or 55:45 to 65:35, or 65:35 to 75:25, or 75:25 to 85:15, or 85:15 to 95:5, or 95:5 to 100:0. According to some embodiments, the polyetherketoneketone is composed of repeating units of formula (I) and formula (II), wherein the ratio of units of formula (II) to units of formula (I) (denoted as ratio T:I) is 55:45 to 95:5.

[0070] According to some embodiments, the polyetherketone ketone according to the invention is substantially composed of repeating units (I) and optionally repeating units of type (II), or is composed of repeating units (I) and optionally repeating units of type (II), wherein the ratio T:I is 0:100 to 50:50. In particular, the ratio T:I may be 0:100 to 5:95, or 5:95 to 10:90, or 10:90 to 20:80, or 20:80 to 30:70, or 30:70 to 40:60, or 40:60 to 50:50.

[0071] The polymerization reaction involved is a condensation polymerization, which involves electrophilic substitution between one or more aromatic ethers and one or more acyl chlorides in a reaction solvent in the presence of a Lewis acid and optionally a chain restrictor. The polymerization is also precipitation-based due to the fact that the formed polymer precipitates from the reaction medium. It is also exothermic. Hydrogen chloride is produced during the condensation polymerization.

[0072] The present invention comprises a premix of aromatic ethers (one or more), acyl chlorides (one or more), and Lewis acids at sufficiently low temperatures, such that polymerization is kept extremely limited or even suppressed in the premix. The polymerization is then activated by dispersing all or part of the premix in a preheated reaction solvent at a moderate polymerization temperature of 40°C to 80°C, such that the reaction mixture reaches this temperature immediately or almost immediately. The inventors have found, quite unexpectedly, that initiating polymerization at these moderate temperatures allows for i) obtaining polymers with a lower proportion of low molecular weight molecules than in prior art methods (where polymerization is carried out by contacting the premix with a reaction solvent preheated to 100°C), ii) simultaneously ensuring limited scaling in the polymerization reactor due to gel formation, and iii) obtaining smaller polymer particles with a more uniform size distribution. For precipitation polymerization, which is at least partially carried out at lower temperatures (40°C to 80°C instead of 100°C), this lower proportion of low molecular weight molecules is a completely counterintuitive result. Specifically, those skilled in the art would expect that species present in the reaction medium are less soluble at lower temperatures and less likely to react between reactive species, thereby producing polymers with a higher proportion of low molecular weight molecules.

[0073] Acyl chlorides are selected from: terephthaloyl chloride, isophthaloyl chloride and mixtures thereof.

[0074] Several measures can be taken to ensure that the acyl chlorides used have a satisfactory level of purity. Specifically, acyl chlorides are readily hydrolyzable species, and if they are not stored and / or processed under appropriate conditions, they can contain a significant amount of hydrolyzable species as impurities.

[0075] In particular, the acyl chloride must be kept away from water and / or a humid atmosphere at all times before being placed in the reactor. Therefore, it is advantageous to store the acyl chloride in a sealed container that is not exposed to ambient air, or alternatively, in a container containing dry air. Advantageously, the acyl chloride can be kept under a dry nitrogen atmosphere before being placed in the reactor to avoid any contact with ambient air.

[0076] The aromatic ethers are selected from: diphenyl ethers, 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or mixtures thereof.

[0077] 1,3-Bis(4-phenoxybenzoyl)benzene has the following chemical formula:

[0078] [Chemical Formula 6]

[0079] (III)

[0080] 1,4-Bis(4-phenoxybenzoyl)benzene has the following chemical formula:

[0081] [Chemical Formula 7]

[0082] (IV).

[0083] According to some embodiments, the aromatic ether or mixture of aromatic ethers comprises at least 60 mol%, or at least 70 mol%, or at least 80 mol%, or at least 90 mol%, or at least 95 mol%, or at least 99 mol% of 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene, optionally taken as a whole, relative to the total molar number of aromatic ethers.

[0084] According to some embodiments, a mixture of aromatic ethers is used. It is essentially composed of 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene or 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene.

[0085] According to some embodiments, a mixture of aromatic ethers is used. It consists of 1,4-bis(4-phenoxybenzoyl)benzene and diphenyl ether. The mixture may comprise up to 20 mol%, preferably up to 10 mol%, more preferably up to 5 mol%, and most preferably up to 1 mol% of diphenyl ether relative to the total molar percentage of the aromatic ethers.

[0086] According to some embodiments, the aromatic ether is essentially composed of 1,4-bis(4-phenoxybenzoyl)benzene or 1,4-bis(4-phenoxybenzoyl)benzene.

[0087] According to some embodiments, a mixture of aromatic ethers is used. It consists of 1,3-bis(4-phenoxybenzoyl)benzene and diphenyl ether. The mixture may comprise up to 20 mol%, preferably up to 10 mol%, more preferably up to 5 mol%, and most preferably up to 1 mol% of diphenyl ether relative to the total molar percentage of the aromatic ethers.

[0088] According to some embodiments, the aromatic ether is essentially composed of 1,3-bis(4-phenoxybenzoyl)benzene or 1,3-bis(4-phenoxybenzoyl)benzene.

[0089] According to some embodiments, the aromatic ether is essentially composed of 1,4-bis(4-phenoxybenzoyl)benzene or 1,4-bis(4-phenoxybenzoyl)benzene. Polyether ketones with a ratio T:I of 50:50 to 100:0 can be obtained by mixing isophthaloyl chloride and terephthaloyl chloride and adjusting the isophthaloyl chloride / terephthaloyl chloride ratio.

[0090] According to some embodiments, the acyl chloride is only terephthaloyl chloride. Polyetherketone ketones with a ratio T:I of 50:50 to 100:0 can be obtained by using a mixture consisting essentially of 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene or of 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene, and by adjusting the ratio of 1,3-bis(4-phenoxybenzoyl)benzene to 1,4-bis(4-phenoxybenzoyl)benzene.

[0091] In a similar manner, according to some embodiments, the aromatic ether is essentially composed of 1,3-bis(4-phenoxybenzoyl)benzene or 1,3-bis(4-phenoxybenzoyl)benzene (or, respectively, the acyl chloride is only isophthaloyl chloride). By adjusting the ratio of isophthaloyl chloride to terephthaloyl chloride (or, respectively, by adjusting the ratio of 1,3-bis(4-phenoxybenzoyl)benzene to 1,4-bis(4-phenoxybenzoyl)benzene), polyetherketones with a ratio T:I of 0:100 to 50:50 can be obtained.

[0092] Lewis acids can be selected from: aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, tin chloride, titanium tetrachloride, and molybdenum pentachloride and mixtures thereof.

[0093] Preferably, only one type of Lewis acid is used in the polymerization reaction.

[0094] Among the Lewis acids mentioned above, aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, ferric chloride, gallium trichloride, and molybdenum pentachloride are preferred.

[0095] Aluminum trichloride is a particularly preferred choice.

[0096] Preferably, the Lewis acid is added in solid form. Alternatively, it may be added in suspension or colloidal form (i.e., as a heterogeneous mixture of solid particles of the Lewis acid in a solvent) or in solution form (i.e., as a homogeneous mixture in a solvent). The solvent used for suspension / colloid or solution is advantageously a reaction solvent.

[0097] According to some variations, Lewis acids are added in particulate form, for example, in powder form (having, for example, a Dv80 of less than 1 mm and a Dv50 of less than 0.5 mm). The parameters Dv80 and Dv50 are the 80th and 50th percentiles (by volume) of the cumulative particle size distribution of the Lewis acid particles, respectively. These parameters can be determined, in particular, by sieving.

[0098] The Lewis acid used in the method according to the invention preferably has a purity such that when it is introduced into water at 20°C with a concentration of 11% by weight and dissolved substantially, it comprises less than 0.1% by weight of insoluble matter, and more preferably less than 0.05% by weight of insoluble matter, as measured by gravimetric analysis.

[0099] The reaction solvent can be selected from: o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene and mixtures thereof.

[0100] o-Dichlorobenzene is particularly preferred.

[0101] The reaction solvent preferably contains less than 500 ppm of water by weight to limit the hydrolysis reaction of the acyl chloride or mixture of acyl chlorides. Advantageously, the reaction solvent contains less than 250 ppm of water by weight, preferably less than 150 ppm of water by weight, and more preferably less than 100 ppm of water by weight.

[0102] In a preferred variation, the aromatic ether or mixture of aromatic ethers also preferably contains less than 500 ppm of water by weight to limit the hydrolysis reaction of the acyl chloride or mixture of acyl chlorides. The range of the same preferred values ​​as for the reaction solvent, with necessary modifications, applies to the aromatic ether or mixture of aromatic ethers.

[0103] In even more preferred variations, the reaction solvent and the aromatic ether or mixture of aromatic ethers together comprise less than 500 ppm of water by weight to limit the hydrolysis reaction of the acyl chloride or mixture of acyl chlorides. Considering the whole, the range of the same preferred values ​​as for the reaction solvent, with necessary modifications, applies to the reaction solvent and the aromatic ether or mixture of aromatic ethers.

[0104] To ensure the absence of trace amounts of water in the reactor, the method advantageously includes a preliminary drying step, i.e., reducing the water content of the reaction solvent and / or the aromatic ether or mixture of aromatic ethers before contacting them with acyl chlorides or mixtures of acyl chlorides. Means for carrying out this preliminary drying step include, for example, distilling the chemical compounds, contacting them with molecular sieves, or even contacting them with a dehydrating agent such as a small amount of aluminum chloride.

[0105] The use of one or more chain restrictors in the reaction medium is optional. Their addition allows for better control of the degree of polymerization and, therefore, better control of the viscosity of the polymer to be manufactured. It also allows for better control of the chain ends of the polymer and, where appropriate, ensures better stability of the polymer, particularly better thermal stability.

[0106] Two types of chain restrictors can be used: nucleophilic chain restrictors or electrophilic chain restrictors.

[0107] According to some embodiments, the chain limiting agent is a nucleophilic chain limiting agent. The nucleophilic chain limiting agent may be particularly selected from compounds having the following chemical formulas:

[0108] [Chemical Formula 8]

[0109] (IV)

[0110] in:

[0111] X1 indicates: covalent bond, -O-, or -S-; and

[0112] X2 represents C6H5CO or C6H5SO2;

[0113] Or compounds with the following chemical formulas:

[0114] [Chemical Formula 9]

[0115] (V)

[0116] in:

[0117] X3 is a halogen, an alkyl or alkoxy group containing 1 to 10 carbon atoms.

[0118] Preferably, the nucleophilic chain restrictor is selected from: 4-phenoxybenzophenone, 4-phenoxydiphenyl sulfone, anisole, fluorobenzene, chlorobenzene, biphenyl, toluene, and mixtures thereof.

[0119] A particularly advantageous nucleophilic chain restrictor is 4-phenoxybenzophenone.

[0120] According to some embodiments, the chain limiting agent is an electrophilic chain limiting agent. The electrophilic chain limiting agent may particularly be selected from compounds of the following formula:

[0121] [Chemical Formula 10]

[0122] (VI);

[0123] [Chemical Formula 11]

[0124] (VII)

[0125] in:

[0126] X4 represents: hydrogen atom, halogen atom, alkyl or alkoxy group containing 1 to 10 carbon atoms, nitro group, C6H5CO or C6H5SO2 group; or compounds of the following formula:

[0127] [Chemical Formula 12]

[0128] (VIII),

[0129] [Chemical Formula 13]

[0130] (IX), where:

[0131] X n Represents n groups, where n is an integer selected between 2 and 5, and each group is independently selected from: halogen atoms, alkyl or alkoxy groups containing 1 to 10 carbon atoms, nitro groups, C6H5CO or C6H5SO2.

[0132] Preferably, the electrophilic chain restrictor is selected from: benzoyl chloride, acetyl chloride, 3,5-dichlorobenzoyl chloride, 3,5-difluorobenzoyl chloride, p-fluorobenzoyl chloride, p-chlorobenzoyl chloride, p-methoxybenzoyl chloride, benzenesulfonyl chloride, p-chlorobenzenesulfonyl chloride, p-methylbenzenesulfonyl chloride, 4-benzoylbenzoyl chloride, and mixtures thereof.

[0133] Advantageously, the chain restrictor is an electrophilic chain restrictor selected from benzoyl chloride, p-fluorobenzoyl chloride, 3,5-difluorobenzoyl chloride, or mixtures thereof. These chain restrictors are readily measurable (measured) because they are liquid at room temperature, have low cost, and ensure good thermal stability of the polymer.

[0134] According to some implementation methods, benzoyl chloride is used as a chain restrictor.

[0135] According to some implementation methods, p-fluorobenzoyl chloride is used as a chain restrictor.

[0136] According to some implementation methods, 3,5-difluorobenzoyl chloride is used as a chain limiting agent.

[0137] In some embodiments where a chain restrictor is used, the chain restrictor may be added at any step of the method.

[0138] According to some implementations, all or some of the chain restrictor may be added with other chemicals to form a premix at T0 or during the step of holding the premix at T0.

[0139] Advantageously, the chain restrictor can be added entirely to the reaction medium before the step of forming the reaction mixture heated to temperature T1.

[0140] The use of a dispersant in the reaction medium is optional and offers no particular advantage. Specifically, the method according to the invention generally allows the omission of such a reagent because it minimizes scaling by bringing the reaction medium from T0 to T1 almost immediately. According to an advantageous embodiment, no dispersant is added to the reaction medium. This has several advantages in particular: it avoids excessive consumption of the introduced Lewis acids and / or promotes the upgrading of process effluents, especially those containing Lewis acids, and / or allows the production of polyetherketones without any trace amounts of dispersant.

[0141] Since the polymerization reaction is a condensation reaction, the aromatic ether or mixture of aromatic ethers is introduced into the reaction medium under substantially stoichiometric conditions relative to the acyl chloride or mixture of acyl chlorides. At the end of the step of contacting at T0 to form the premix, the molar ratio of the aromatic ether to the acyl chloride that has been totaled in the reaction medium is preferably from 0.9:1.1 to 1.1:0.9.

[0142] According to an advantageous embodiment, an aromatic ether is introduced in excess relative to the acyl chloride, preferably at a molar ratio of 1.001 to 1.1 of the aromatic ether to the acyl chloride. In these embodiments, if a chain restrictor is used, it is preferably an electrophilic chain restrictor, and advantageously benzoyl chloride, p-fluorobenzoyl chloride, or 3,5-difluorobenzoyl chloride.

[0143] At the end of the step of contacting at T0 to form the premix, the molar ratio of Lewis acid to aromatic ether that has been introduced into the reaction medium is preferably such that the Lewis acid is in slight excess relative to the total ether functional groups and optionally ketone functional groups of the aromatic ether or mixture of aromatic ethers, as well as the acyl chloride functional groups of isophthaloyl chloride, terephthaloyl chloride, or mixtures thereof. In embodiments in which the aromatic ether is substantially composed of 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene, or mixtures thereof, the molar ratio of Lewis acid to aromatic ether that has been introduced into the reaction medium at the end of the step of contacting at T0 to form the premix is ​​preferably 5.0 to 7.0 and very preferably 5.1 to 6.5.

[0144] The molar ratio of the aromatic ethers introduced into the reaction medium to the reaction solvent at the end of polymerization is preferably at least 0.005, very preferably greater than or equal to 0.008, and more preferably greater than or equal to 0.010.

[0145] At the end of polymerization, the total molar ratio of aromatic ethers introduced into the reaction medium relative to the reaction solvent 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. In contrast, considering that the less reaction solvent contained in the reaction medium, the more likely scaling is to form during polymerization, especially in the absence of a dispersant, the total molar ratio of aromatic ethers introduced into the reaction medium relative to the reaction solvent 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.

[0146] Therefore, according to some embodiments, the molar ratio of the aromatic ether introduced into the reaction medium to the total reaction solvent is 0.005 to 0.030, preferably 0.008 to 0.025, and most preferably 0.010 to 0.022.

[0147] The total molar ratio of aromatic ethers to reaction solvent introduced into the reaction medium may be particularly 0.011 to 0.022, 0.012 to 0.022, 0.013 to 0.022, 0.014 to 0.022, 0.015 to 0.022, 0.016 to 0.022 or 0.017 to 0.022.

[0148] The total molar ratio of the chain limiting agent to the aromatic ether introduced into the reaction medium can be from 0 to 0.12.

[0149] The method according to the invention initially involves contacting the compounds involved in the polymerization reaction. This step specifically involves contacting the reagents—aromatic ethers, acyl chlorides, and Lewis acids—in a portion s1 of the reaction solvent, and optionally with all or some of the chain-limiting agents. These various compounds can theoretically be mixed together in any order.

[0150] For the purposes of this invention, the term "premix" is used from the moment when all or some of the aromatic ethers, all or some of the acyl chlorides, and all or some of the Lewis acids are brought into contact with all or some of the reaction solvent portion s1 at a temperature T0 less than or equal to 25°C. In other words, the "premix" begins to exist at the moment when polymerization can be thermodynamically initiated. However, at T0, polymerization is kinetically suppressed or at least kept extremely limited.

[0151] According to some embodiments, T0 is advantageously less than or equal to 15°C. More preferably, it is less than or equal to 10°C. According to 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.

[0152] According to some implementations, T0 may be particularly within a temperature range of -10°C to 15°C, and preferably -5°C to 10°C.

[0153] The fraction of the reaction solvent, s1, is calculated relative to the total reaction solvent used for the polymerization reaction. It corresponds to the fraction of the solvent used during contact at T0 relative to the total amount of reaction solvent used at the end of the polymerization. Specifically, in the method according to the invention, the reaction solvent is added in the following steps: in addition to the fraction s1 using the reaction solvent forming a premix at T0, a fraction s2 using preheated reaction solvent forming a reaction mixture at T1, and a fraction s3 of the reaction solvent optionally used in an optional step in which the reaction medium is brought to and maintained at temperature T2. This gives: s1 + s2 + s3 = 1.

[0154] The s1 of the reaction solvent can be from 0.25 to 0.75.

[0155] The solvent fraction s1 can be 0.25 to 0.35, or 0.35 to 0.45, or 0.45 to 0.55, or 0.55 to 0.65, or 0.65 to 0.75.

[0156] The solvent fraction s1 will advantageously be selected by those skilled in the art based on the conditions available for carrying out the method. A sufficiently high s1 value particularly allows for sufficiently rapid contact between the Lewis acid and the aromatic ether and / or acyl chloride, while maintaining the reaction medium at T0. A sufficiently high s1 value also allows, where appropriate, easy transfer of the premix at T0 to another reactor by gravity and / or pumping. A sufficiently low s1 value particularly allows for sufficiently rapid contact between the premix at T0 and the preheated solvent fraction s2, while promoting the maintenance of the reaction medium at T1.

[0157] The contact step to obtain the premix is ​​complete, or in other words, the premix is ​​formed when all the aromatic ether or mixture of aromatic ethers, the acyl chloride or mixture of acyl chlorides, the Lewis acid, and a portion of the reaction solvent have been contacted at step s1. The formed premix can be maintained at T0 for a certain time, for example, to ensure good homogenization of the reaction medium.

[0158] Preferably, the contact step to obtain the premix is ​​carried out under stirring.

[0159] For the purposes of this invention, when it is indicated that the reagents are contacted at T0 to prepare a premix and / or the formed premix is ​​kept at T0, this does not presuppose that the temperature is kept constant, but rather means that the temperature of the reaction medium is kept within the temperature range specified (imposed) for T0.

[0160] The step of contacting at T0 to form a premix typically lasts from 15 minutes to 12 hours. On an industrial scale, this step is preferably from 25 minutes to 6 hours and more preferably from 30 minutes to 4 hours.

[0161] Once the premix is ​​formed, the reaction medium may optionally be maintained at T0 for less than one hour and preferably 30 minutes or less. Once the premix is ​​formed at T0, the reaction medium may optionally be maintained at T0 for 15 minutes or less, or 10 minutes or less, or 5 minutes or less.

[0162] Preferably, the premix formed is maintained at T0 while being stirred.

[0163] According to some embodiments, the reaction medium is maintained at T0 for 15 minutes to 13 hours, preferably 25 minutes to 7 hours, and more preferably 30 minutes to 5 hours during the contact step and during the optional step of maintaining the formed premix.

[0164] According to an advantageous embodiment, an aromatic ether, an acyl chloride, and a Lewis acid can be added in two distinct stages to prepare a premix in the presence of a portion s1 of the reaction solvent. In the first stage, two of the reagents are mixed. In the second stage, a third reagent is added in its entirety to the previously obtained mixture, and the reaction medium is maintained at temperature T0 between the start of the second stage in which the addition of the third reagent begins and the end of the second stage in which the addition of the third reagent ceases.

[0165] According to a first embodiment, the first stage involves preparing a mixture comprising all of an aromatic ether or a mixture of aromatic ethers and all of an acyl chloride or a mixture of acyl chlorides in a portion s1 of the reaction solvent. The second stage involves adding all of a Lewis acid to the mixture obtained in the first stage, while the temperature of the reaction medium is maintained at T0.

[0166] According to a second embodiment, the first stage involves preparing a mixture comprising all of an acyl chloride or a mixture of acyl chlorides and all of a Lewis acid in a portion s1 of the reaction solvent. The second stage involves adding all of an aromatic ether or a mixture of aromatic ethers to the mixture obtained in the first stage, while the temperature of the reaction medium is maintained at T0.

[0167] The following sections describe in detail two particularly advantageous embodiments for carrying out the step of contacting chemical compounds in a reactor. The method according to the invention is by no means limited to these illustrative embodiments.

[0168] Advantageously, the first embodiment is carried out in the following order:

[0169] First, a portion of the reaction solvent, s1, is introduced into the reactor. Second, an aromatic ether or a mixture of aromatic ethers is added and dispersed in the reaction solvent in the reactor with stirring. Third, to ensure no trace water remains in the reactor, distillation is performed and the reactor headspace is inertized with nitrogen. Alternatively or additionally, a dehydrating agent (particularly a small amount of aluminum chloride) may be added to remove any remaining trace water. Fourth, an acyl chloride or a mixture of acyl chlorides is added to the reactor with stirring. Fifth, a Lewis acid is introduced with stirring. Since the complexation (complexation) of the Lewis acid with the acyl chloride is an exothermic reaction, the Lewis acid is added to the reactor in a sufficiently slow manner to maintain the premix at temperature T0. The Lewis acid addition step can last from 15 minutes to 12 hours. Where appropriate, an optional homogenization step of the formed premix at T0 can be observed. This optional homogenization step can last for 1 hour or less, and preferably 30 minutes or less.

[0170] The second advantageous implementation method can be carried out in the following order:

[0171] First, a portion of the reaction solvent, s1, is introduced into the reactor. Second, to ensure the absence of trace amounts of water in the reactor, distillation is performed and the reactor headspace is inertized with nitrogen. Alternatively or additionally, a dehydrating agent (particularly a small amount of aluminum chloride) may be added to eliminate any remaining trace amounts of water. Third, an acyl chloride or a mixture of acyl chlorides is added to the reactor with stirring. Fourth, a Lewis acid is introduced with stirring. Since the complexation (complexation) of the Lewis acid with the acyl chloride is an exothermic reaction, the Lewis acid is added to the reactor slowly enough to maintain the reaction mixture at temperature T0. Fifth, once all the Lewis acid has been introduced, an aromatic ether or a mixture of aromatic ethers is introduced to form a premix. The aromatic ether addition step can last from 15 minutes to 12 hours. Where appropriate, an optional homogenization step at T0 can be observed. This optional homogenization step can last 1 hour or less, and preferably 30 minutes or less.

[0172] The method according to the invention involves contacting a formed premix with a portion s2 of a reaction solvent (the portion s2 of the reaction solvent is preheated) to form a reaction mixture that is almost instantaneously heated to a temperature T1 ranging from 40°C to 80°C. For the purposes of this invention, the term "reaction mixture" is used to refer to a reaction medium in which all or some of the formed premix has been contacted with all or some of the preheated portion s2 of the reaction solvent.

[0173] The polymerization reaction (which is kinetically nonexistent or at least very limited at T0) accelerates significantly at T1. This is characterized by a sudden increase in the heat flux emitted by the reaction mixture. It is also characterized by a sudden increase in the production of hydrogen chloride. Finally, it is characterized by a rapid increase in the viscosity of the reaction mixture.

[0174] T1 is 40°C or higher. Specifically, at temperatures below 40°C, excessive gel formation / fouling occurs, which significantly reduces the yield of the method and / or the quality of the obtained polymer. T1 may particularly be greater than or equal to 42°C, or greater than or equal to 44°C, or greater than or equal to 46°C, or greater than or equal to 48°C.

[0175] According to some implementations, T1 has a value of 40°C to 50°C.

[0176] According to some implementations, T1 has a value that is strictly greater than 40°C.

[0177] According to some implementations, T1 has a value that is strictly greater than 50°C.

[0178] T1 is 80°C or lower. Specifically, at temperatures above 80°C, even after purification, the resulting polymer contains a high proportion of low-mass molecules. T1 may be less than or equal to 78°C, or less than or equal to 76°C, or less than or equal to 74°C, or less than or equal to 72°C, or less than or equal to 70°C.

[0179] According to some implementations, T1 has a value of 70°C to 80°C.

[0180] According to some implementations, T1 has a value that is strictly less than 80°C.

[0181] According to some implementations, T1 has a value that is strictly less than 70°C.

[0182] According to some implementations, T1 has a value of 50°C to 60°C. In particular, T1 may have a value of 52°C to 60°C.

[0183] According to some implementations, T1 has a value of 60°C to 70°C. T1 may particularly have a value of 60°C to 68°C.

[0184] The fraction of the reaction solvent, s², is calculated relative to the total amount of reaction solvent added at the end of polymerization. The fraction of the reaction solvent, s², can be between 0.25 and 0.75.

[0185] The solvent portion s2 can be 0.25 to 0.35, or 0.35 to 0.45, or 0.45 to 0.55, or 0.55 to 0.65, or 0.65 to 0.75.

[0186] According to some implementations, s1+s2≥0.75. Advantageously, s1+s2≥0.85. In particular, s1+s2≥0.90 or s1+s2≥0.95 may be present.

[0187] According to the specific implementation method, s1+s2=1, that is, once the reaction mixture is formed in T1, all the reaction solvent has been introduced.

[0188] According to some implementations, s1 ranges from 0.25 to 0.45, s2 ranges from 0.55 to 0.75, and s1+s2≥0.75.

[0189] According to some implementations, s1 ranges from 0.45 to 0.65, s2 ranges from 0.35 to 0.55, and s1+s2≥0.75.

[0190] According to some implementations, s1 ranges from 0.55 to 0.75, s2 ranges from 0.25 to 0.45, and s1+s2≥0.75.

[0191] According to some implementations, s1 ranges from 0.25 to 0.45, s2 ranges from 0.55 to 0.75, and s1+s2=1.

[0192] According to some implementations, s1 ranges from 0.45 to 0.65, s2 ranges from 0.35 to 0.55, and s1+s2=1.

[0193] According to some implementations, s1 ranges from 0.55 to 0.75, s2 ranges from 0.25 to 0.45, and s1+s2=1.

[0194] Preferably, the formed premix is ​​gradually poured into all or some of the portion s2 of the preheated reaction solvent at a rate suitable for maintaining the temperature of the reaction medium within the temperature range specified for T1 to form the reaction mixture.

[0195] According to some embodiments, the formed premix is ​​gradually poured into the entire (whole) portion s2 of the preheated reaction solvent. In this embodiment, the solvent portion s2 is typically preheated to a temperature within the temperature range specified for T1. To maintain the reaction mixture within the temperature range specified for T1 to form the reaction mixture, additional heat can be supplied via reactor heating and / or cooling devices.

[0196] According to some embodiments, the solvent portion s2 can be further subdivided (re-divided) into two sub-portions s2' and s2'', such that s2 = s2' + s2''. According to these embodiments, the formed premix can be gradually poured into the portion s2' of the reaction solvent, which is typically preheated to a temperature within the temperature range specified for T1. The solvent portion s2'' is preheated to a temperature higher than that of portion s2', for example, to a temperature of 80°C to 120°C, and is gradually poured into the reaction medium while the premix is ​​being formed, such that the reaction mixture is maintained within the temperature range specified for T1. Additional heat flow can also be supplied via reactor heating and / or cooling devices to maintain the reaction mixture within the temperature range specified for T1 to form the reaction mixture. Preferably, s2'' ≤ s2'.

[0197] The step of contacting to obtain the reaction mixture at T1 ends, or in other words, when all of the premix at T0 and part of the reaction solvent at T2 have been contacted, the reaction mixture is formed.

[0198] In this invention, when the formed premix is ​​contacted with a portion s2 of the solvent to obtain a reaction mixture at T1 and / or the formed reaction mixture is maintained at T1, this does not presuppose that the temperature is kept constant, but rather means that the temperature of the reaction medium is maintained within a temperature range specified for T1. The formed reaction mixture can be maintained at T1 for a certain time, for example, to achieve a given degree of polymerization.

[0199] Preferably, the contact to obtain the reaction mixture at T1 is carried out under stirring, such that the formed premix is ​​properly dispersed in a portion of the preheated reaction solvent. Advantageously, stirring is carried out with a dual-flow stirring system, which keeps the reaction mixture in motion, particularly at the level of the sidewalls of the reactor, and / or by means of a bottom turbine, which keeps the reaction mixture in motion, particularly at the level of the bottom wall of the tank, and thus prevents accelerated scaling of the reactor.

[0200] The contact process to form the reaction mixture at T1 typically lasts from 15 minutes to 3 hours, and preferably from 25 minutes to 60 minutes.

[0201] Once the reaction mixture has formed at T1, the reaction medium can optionally be maintained at T1 for 0 minutes to 6 hours, and preferably 10 minutes to 60 minutes.

[0202] Preferably, the reaction mixture formed is maintained at T1 while being stirred.

[0203] According to some embodiments, the reaction mixture is maintained at T1 for 15 minutes to 8 hours and preferably 30 minutes to 120 minutes during the contact step and during the optional step of maintaining the formed reaction mixture.

[0204] During the step of contacting the formed premix with a portion of the preheated reaction solvent (s2) and optionally during the step of holding the formed reaction mixture at T1, the reaction mixture can be held at T1 to achieve a certain degree of conversion of the polymerization reagents. This degree of conversion can be assessed in various ways: by determining the monomer remaining in the reaction medium, measuring the hydrogen chloride produced during the polymerization reaction, the viscosity of the reaction medium, or assessing the percentage fraction of molecular mass (molecular matter) strictly below 500 g / mol, as described below.

[0205] Preferably, during the step of contacting the formed premix with a portion of the preheated reaction solvent (s2) and optionally during the step of holding the reaction mixture at T1, the reaction mixture is held at T1 until the percentage of the molecular weight in the reaction mixture, which is strictly less than 500 g / mol in PMMA equivalent, is less than or equal to 50%, preferably less than or equal to 25%, and more preferably less than or equal to 15%.

[0206] According to some embodiments, during the step of contacting the formed premix with the s2 portion of the preheated reaction solvent and during the step of holding at T1, the reaction mixture is held at T1 until the desired degree of polymerization is obtained.

[0207] According to some embodiments, after the reaction mixture is formed at T1 and optionally maintained at T1, the reaction mixture can be brought to T2 and maintained at T2 for a certain period of time (T2 is in a temperature range from a temperature at least 10°C higher than T1 to a temperature of 120°C) to achieve the desired degree of polymerization. For this purpose, additional heat can be supplied by a reactor heating device and / or by adding a portion of preheated reaction solvent, s3 (typically at a temperature within the temperature range specified by T2). This optional step allows the desired degree of polymerization to be achieved more quickly compared to embodiments in which the reaction mixture is merely maintained at T1. In these embodiments, T2 is preferably in the range of 80°C to 120°C, more preferably 82°C to 105°C, and extremely preferably 85°C to 95°C.

[0208] According to an advantageous embodiment, hydrogen chloride generated during the polymerization reaction is extracted from the reactor during polymerization to promote the polymerization reaction. For this purpose, all or part of the polymerization can be carried out under reduced pressure, at an absolute pressure of 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 additionally, an inert gas (e.g., helium, argon, or nitrogen) is bubbled into the reaction mixture. However, this method is not preferred because it generates additional turbulence in the reaction mixture and makes it more difficult to control the temperature within the reactor.

[0209] The method can be carried out in one reactor or a series of reactors.

[0210] In an advantageous embodiment, the contact to form the premix at T0 and the contact to form the reaction mixture at T1 are carried out in two separate reactors.

[0211] In embodiments where the reaction mixture is then brought to T2, this step can be carried out in the same reactor used for contacting to form the reaction mixture at T1.

[0212] The reactor that can be used to carry out the present invention can be, for example, a glass reactor, an enamel reactor, or a reactor with corrosion-resistant metallurgy.

[0213] The reactor preferably has a temperature control device and a device for measuring the temperature therein. The reactor may specifically include one or more temperature sensors and be configured to cool and / or heat the medium it contains.

[0214] The reactors used in carrying out the present invention are preferably equipped with stirring devices, such as mechanical stirrers (which may include, for example, one or more stirring rotors) or recirculation loops with pumps.

[0215] The reactor that can be used for the step of forming a reaction mixture at T1 has an advantageous dual-flow stirring system.

[0216] After the polymerization reaction has been completed to the desired degree of polymerization, the method of the present invention may include purifying the polyether ketone from the product mixture in a manner known per se. For example, this has been described in EP3655458.

[0217] In particular, this purification allows for the separation of solvents, catalysts, unreacted reagents, and any reaction byproducts from polymers like this.

[0218] In particular, purification typically involves contacting the product mixture with a protic solvent to collect a first phase comprising Lewis acids and a second phase comprising polyether ketones.

[0219] The protic solvent can be an aqueous solution. The aqueous solution can simply be 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. When using an acidic solution, the dissociation of the polyether ketone / Lewis acid complex (complex) is more efficient.

[0220] Solvent mixtures, such as water-organic solvents, such as aqueous solutions mixed with methanol, ethanol, isopropanol, or acetic acid, may also be used. Preferably, a mixture of an aqueous solution and an alcohol, particularly methanol, ethanol, or isopropanol, is used, comprising 95% to 60%, preferably 80% to 95% by weight, of the alcohol.

[0221] The product mixture is brought into contact with a protic solvent to form a first phase (containing the protic solvent) and a second phase (containing the reaction solvent). Lewis acids exist primarily in dissolved form in the first phase, while polyether ketones exist primarily in precipitated form in the second phase.

[0222] The polyether ketone can then be recovered by solid / liquid separation of the second phase. Advantageously, solid / liquid separation is performed by centrifugal filtration.

[0223] The dry solids content of the crude polyether ketone product at the end of the solid / liquid separation step is preferably between 10% by weight and 90% by weight, more preferably between 15% by weight and 75% by weight, and even more preferably between 20% by weight and 50% by weight.

[0224] The liquid effluent containing the first and second phases can optionally be separated for individual collection, preferably by decantation, for possible reuse. Surfactants can be added to promote phase separation. When the Lewis acid is aluminum trichloride, the first phase advantageously contains it in a suitable proportion, allowing it to be directly recycled for water treatment / sludge flocculation processes.

[0225] According to a preferred embodiment, the crude polyether ketone product at the end of the aforementioned solid / liquid separation step can be further purified by washing with one or more protic solvents.

[0226] The proton solvent at this stage is preferably water or an aqueous solution. However, in other variations, the proton solvent at this stage may also be an organic solvent, optionally miscible with water. Straight-chain or branched aliphatic alcohols such as methanol, ethanol, and isopropanol are particularly preferred organic solvents. These organic solvents may optionally be miscible with each other and / or with water.

[0227] Further solid / liquid separation steps may be performed after or simultaneously with the washing step.

[0228] According to an advantageous embodiment, a centrifugal filtration device is used, which allows washing and solid / liquid separation to be performed simultaneously in the device without resuspension of the product.

[0229] After the final solid / liquid separation, the collected solids are advantageously dried.

[0230] The drying step can be carried out conventionally, for example at a temperature ranging from 100°C to 280°C and at atmospheric pressure, or preferably under reduced pressure, such as at a pressure of 30 mbar. After drying, the polyether ketone typically has a reaction solvent content of less than or equal to 50 ppm, preferably less than or equal to 30 ppm, and more preferably less than or equal to 15 ppm, relative to the weight of the polymer.

[0231] Polymers that can be manufactured according to the method of the invention typically have an intrinsic viscosity of 0.4 to 2.0 dL / g, and preferably 0.75 to 1.45 dL / g, which is measured at 25°C in a 96.00% sulfuric acid solution (mast fraction) at a concentration of 0.0005 g / mL using an Ubbelohde suspension surface viscometer (with an inner diameter of 1.03 mm) according to the standard ISO 307-2009 applied to PEKK.

[0232] According to some embodiments, polyetherketoneketone has an intrinsic 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.

[0233] Polyetherketoneketones (PEKKs) that can be manufactured according to the method of the present invention have the following advantages: they generally do not contain any dispersants in the form of impurities, particularly those described in WO 9 523 821 and US 2012 / 0263953 (except in less advantageous embodiments where dispersants are used). Therefore, PEVKKs according to the present invention generally do not contain benzoic acid or its derivatives as used as dispersants as described in US 2012 / 0263953. In particular, PEVKKs generally do not contain any of the following compounds: benzoic acid, methylbenzoic acid, sodium benzoate, magnesium benzoate, aluminum benzoate, methyl benzoate, and benzenesulfonic acid. In particular, PEVKKs generally do not contain any benzoic acid. Therefore, PEVKKs according to the present invention generally also do not contain any other polymers used as dispersants, such as those described in WO 9 523 821. PEVKKs particularly generally do not contain any copolymers of aliphatic vinyl compounds and N-vinylpyrrolidone.

[0234] The polyether ketone that can be manufactured according to the method of the present invention consists of three molecular weight fractions A, B and C, wherein A represents a percentage fraction of molecular weight strictly below 500 g / mol, B represents a percentage fraction of molecular weight ranging from 500 g / mol to 3000 g / mol, and C represents a percentage fraction of molecular weight strictly above 3000 g / mol, in PMMA equivalent.

[0235] This gives A+B≤5.0% and A+B+C=100%.

[0236] Preferably, A ≤ 1.0%. Very low molecular weight molecules can be eliminated to very low concentrations using methods known to those skilled in the art, which are more or less complex. For example, an azeotropic distillation method has been described in WO 2014 / 013202. Preferably, particularly by using such a method, A ≤ 0.5%, or even A ≤ 0.3%.

[0237] Preferably, B ≤ 4.0%. Low molecular weight molecules are difficult to eliminate using even advanced and / or complex extraction methods (see Example 3). According to an advantageous embodiment, the method according to the invention allows for B ≤ 3.5%, and preferably B ≤ 3.2%.

[0238] According to some advantageous implementation methods, B≤3.2, or B≤3.1, or B≤3.0, or B≤2.9, or B≤2.8, or B≤2.7, or B≤2.6, or B≤2.5, or B≤2.4, or B≤2.3, or B≤2.2, or B≤2.1, or B≤2.0 can be achieved.

[0239] The advantage of such polymers with low B-parts is that they can be extruded, especially granulated, and allow for the production of objects with few defects, particularly few black spots.

[0240] According to some implementations, particularly when T1 ranges from 68°C to 80°C, B ≤ 3.8%, preferably B ≤ 3.5%, and more preferably B ≤ 3.2%.

[0241] According to some implementations, particularly when T1 ranges from 60°C to 68°C, B ≤ 3.2%, or B ≤ 3.1%, or B ≤ 3.0%.

[0242] According to some implementations, specifically when T1 ranges from 52°C to 60°C, B ≤ 3.0%, or B ≤ 2.9%, or B ≤ 2.8%.

[0243] According to some implementations, particularly when T1 ranges from 40°C to 52°C, B ≤ 2.8%, or B ≤ 2.7%, or B ≤ 2.6%.

[0244] The polyetherketone ketone obtained by the method according to the invention is typically in the form of fairly uniformly sized flakes that form a powder. In particular, and advantageously, the polymer has very few large flakes. This is particularly advantageous for facilitating purification. Specifically, the extraction of aluminum chloride and / or impurities generated by polymerization from the reduced-size particles is simpler and more efficient. Additionally, drying can be performed more rapidly. Furthermore, it is easier to feed the powder into equipment used for grinding, sieving, compacting, granulating, and extruding such powders.

[0245] Advantageously, relative to the total weight of the powder particles, the polyether ketone ketone powder according to the invention has a mass ratio of less than or equal to 50% of particles having a size strictly greater than 1000 micrometers, as obtained by sieving using a sieve with an aperture size equal to 1 millimeter.

[0246] According to some embodiments, the polyether ketone ketone powder according to the present invention has a mass ratio of less than or equal to 25% of particles having a size strictly greater than 1000 micrometers.

[0247] According to some embodiments, the mass percentage of particles having a size strictly greater than 1000 micrometers is less than or equal to 15%, preferably less than or equal to 10%, and extremely preferably less than or equal to 5%.

[0248] According to some embodiments, the mass proportion of particles with a size range of 315 micrometers to 1000 micrometers is greater than or equal to 50%, such as by using a sieve with an aperture size of 1 millimeter and a sieve with an aperture size of 315 micrometers. Preferably, the mass proportion of particles with a size range of 315 micrometers to 1000 micrometers may be greater than or equal to 80%. According to these embodiments, the mass proportion of particles with a size strictly smaller than 315 micrometers is advantageously less than or equal to 10%, and the mass proportion of particles with a size strictly larger than 1000 micrometers is less than or equal to 10%.

[0249] According to some embodiments, the mass proportion of particles having a size strictly less than 630 micrometers is greater than or equal to 50%, preferably greater than or equal to 70%, and more preferably greater than or equal to 85%.

[0250] According to some embodiments, the polyetherketone ketone sheet formed into powder has a density greater than or equal to 180 kg / m³. 3 The tap density. Preferably, the polyetherketone sheet forming the powder has a tap density greater than or equal to 200 kg / m³. 3The tap density. Depending on the intended application, a sufficiently high tap density offers several advantages. In granulation, it reduces the amount of air introduced into the extruder and improves the melt stability of the polymer. In laser sintering, it improves the cohesion of the powder bed after grinding into a fine powder. Tap density is typically kept below 400 kg / m³. 3 It can be particularly small, less than 350 kg / m³. 3 or even less than or equal to 300 kg / m 3 or even less than or equal to 250 kg / m 3 .

[0251] Measurement methods

[0252] The following measurement methods are applied to the present invention, and particularly in the embodiments given below.

[0253] Determination of parts (fractions) A, B, and C

[0254] Approximately 30 mg of the polymer component to be evaluated was placed in 1 ml of 4-chlorophenol at 150°C for 2 hours. After the solution cooled to room temperature, 14 ml of hexafluoroisopropanol (HFIP) was added, and the solution was then filtered through an Acrodisc syringe filter consisting of a polytetrafluoroethylene (PTFE) membrane with a diameter of 25 mm and a porosity of 0.2 μm. The molar mass of the resin in the sample was determined by size exclusion chromatography using a Waters Alliance 2695 instrument under the following conditions:

[0255] - Flow rate: 1.00 ml / min. Eluent: HFIP. Injection volume: 100.00 μl. PSS PFG column group (1000+100 Å) 25 2×30 cm. Temperature: 40°C. Detection method: Differential refractometer. - Calibration: PMMA with a molecular weight range of 402 g / mol to 1,900,000 g / mol, updated for each series of analyses.

[0256] The chromatogram baseline and integral were generated according to the recommendations (recommendations) of standard ISO 16014-1:2019, namely:

[0257] - The baseline is typically set at an elution volume (Vi) between 0 and 10 mL.

[0258] - The baseline is typically set at an elution volume (Vf) between 30 and 40 ml.

[0259] The chromatogram integration (area) begins when the signal differs from the zero level defined by the baseline (referred to as (Va)). The chromatogram integration (area) ends before the system peak, i.e., typically at the elution volume (Vb) corresponding to a mass between 50 and 200 g / mol of PMMA equivalent. The integration for masses less than 500 g / mol begins at the elution volume (V500) corresponding to a molar mass of 500 g / mol of PMMA equivalent and ends at the final integration of the chromatogram (i.e., Vb). The integration for masses less than 3000 g / mol begins at the elution volume (V3000) corresponding to a molar mass of 3000 g / mol of PMMA equivalent and ends at the final integration of the chromatogram (i.e., Vb).

[0260] The determination of the molar mass fraction (in PMMA equivalent) strictly less than 500 g / mol (referred to as fraction A in this invention and expressed as a percentage) is made by calculating the ratio of the integral area of ​​the molar mass between 0 and 500 g / mol to the integral area of ​​the total chromatogram according to the following calculation:

[0261] [Mathematical Expression 1]

[0262]

[0263] The molar mass fraction (referred to as fraction B and expressed as %) in the range of 500 g / mol (in PMMA equivalent) to 3000 g / mol (in PMMA equivalent) was determined by the following calculations:

[0264] [Mathematical Expression 2]

[0265]

[0266] The determination of the molar mass fraction (in this invention denoted as fraction C and expressed as %) of strictly greater than 3000 g / mol (in PMMA equivalent) is performed by the following calculations:

[0267] [Mathematical Expression 3]

[0268]

[0269] Measurement of intrinsic viscosity

[0270] The intrinsic viscosity η is measured at 25°C in 96.00% sulfuric acid solution at a concentration of 0.0005 g / mL using an Ubbelohde type suspension surface viscometer according to standard ISO 307-2009. inh .

[0271] Determination of particle size distribution

[0272] Particle size distribution was evaluated by sieving on sieves with sieve aperture sizes equal to specified limits (315 μm, 630 μm, 800 μm, and 1000 μm).

[0273] Measurement of tap density

[0274] Tap density shall be measured in the following manner according to standard ISO 1068-1975(F):

[0275] - Condition the powder at 23°C and 50%RH for 24 hours.

[0276] - Introduce a specific volume of powder into a precisely graduated 250 ml glass graduated cylinder;

[0277] - If necessary, level the free surface of the powder without tapping it and record the volume V0;

[0278] Weigh the graduated cylinder containing the powder on a balance with an accuracy of 0.1g, the balance having been pre-balanced (tare weight);

[0279] - Place the measuring cylinder on the plate of the STAV 2003 tapping machine (vibration compactor);

[0280] - Tap it 1250 times and record the volume V1;

[0281] - Tap it 1250 times and record the volume V2;

[0282] - Repeat the tapping operation until two equivalent volumes Vi are obtained.

[0283] - Record Vf corresponding to the same volume Vi.

[0284] Tap density is the mass of the introduced powder divided by Vf. It is expressed in kg / m³. 3 express.

[0285] Example

[0286] Example 1

[0287] Two jacketed reactors (R1 and R2) are used, each connected to a thermal conditioning system using a suitable heat transfer liquid and each equipped with a stirrer and a system for inertization in the headspace under a flow of nitrogen.

[0288] In reactor R1, using ethylene glycol-water as the heat transfer liquid, a premix was prepared as follows: First, o-dichlorobenzene and 1,4-bis(4-phenoxybenzoyl)benzene were added under stirring at a mass ratio of 0.128 (partial s1 = 0.68). Then, under stirring, a mixture of terephthaloyl chloride and isophthaloyl chloride in a molar ratio of 0.77 was added to the reaction medium, such that the total amount of isophthaloyl chloride and terephthaloyl chloride was substantially equimolar relative to 1,4-bis(4-phenoxybenzoyl)benzene (the molar ratio of 1,4-bis(4-phenoxybenzoyl)benzene to the mixture of terephthaloyl chloride and isophthaloyl chloride was 1.03). Benzoyl chloride was added as a chain limiting agent while stirring, at a molar ratio of 0.042 relative to 1,4-bis(4-phenoxybenzoyl)benzene. The reaction medium in reactor R1 was then cooled to -5°C. Solid aluminum trichloride was added over approximately 1 hour while stirring to form a premix, the temperature of which was maintained at approximately -5°C throughout the aluminum trichloride addition step. The molar ratio of aluminum trichloride to 1,4-bis(4-phenoxybenzoyl)benzene was 6.3. Once the aluminum trichloride was added, the temperature of the premix in R1 was maintained at approximately -5°C for 30 minutes.

[0289] Simultaneously, o-dichlorobenzene (partial s2=0.32) was added to reactor R2 at a mass ratio of 0.060 of the premix of 1,4-bis(4-phenoxybenzoyl)benzene to o-dichlorobenzene in R2 (reactor R2 had oil as the heat transfer liquid and was equipped with a stirring system with two stirring rotors), and heated to temperatures of 55°C (Test #1), 65°C (Test #2), or 90°C (Test #3, control). The premix in R1 at 0°C was gradually transferred to reactor R2 under stirring using a pump and maintained at 55°C (Test #1), 65°C (Test #2), and 90°C (Test #3, control). The transfer operation lasted for 30 minutes. The resulting reaction mixture was then maintained at 55°C (Test #1), 65°C (Test #2), and 90°C (Test #3, control) for 10 minutes, 10 minutes, and 40 minutes, respectively.

[0290] For tests #1 and #2, the temperature in reactor R2 was then rapidly increased until it reached 90°C. The reaction mixture was then maintained at 90°C for 30 minutes.

[0291] For tests #1, #2, and #3, the final product mixture was cooled to approximately 50°C. Purification was performed by mixing with an aqueous hydrochloric acid solution having a pH ≤ 3 and then performing solid / liquid separation using a filter. The crude polymer was then washed three times by resuspension followed by filtration, using methanol, 3% hydrochloric acid solution, and water, successively.

[0292] Finally, the purified polymer was dried under vacuum (30 mbar) at 180°C for 24 hours.

[0293] The results of determining the fractions (A, B, and C) of the polymer components obtained from each test, as well as the measurement results of the intrinsic viscosity, are shown in Table 1 below:

[0294] [Table 1]

[0295]

[0296] The granularity distribution for each test is plotted on... Figure 1 On the diagram.

[0297] Based on the results presented in Table 1, it can be concluded that the polymers according to Examples #1 and #2 have fewer low molecular weight molecules, particularly fewer molecules with a molecular weight of less than or equal to 3000 g / mol, and particularly fewer molecules with a molecular weight of 500 g / mol to 3000 g / mol, compared to the polymer according to Comparative Example #3.

[0298] Given Figure 1 The results shown lead to the conclusion that the powders according to Examples #1 and #2 are sub-millimeter-sized powders with a fairly uniform particle size distribution, which differs from the powder according to Comparative Example #3, which has millimeter-sized particles and a very non-uniform particle size distribution.

[0299] Example 2

[0300] The polymerization kinetics were studied at 65°C by preparing a premix at T0 as described in Example 1. Simultaneously, o-dichlorobenzene (partial s2 = 0.32) was added to reactor R2 at a mass ratio of 0.060 of the premix to o-dichlorobenzene in R2 and heated to 65°C. Reactor R2 had oil as the heat transfer liquid and was equipped with a dual-flow stirring system. The premix in R1 at 0°C was gradually transferred to reactor R2 under stirring using a pump and maintained at 65°C. The transfer operation lasted for 30 minutes. The resulting reaction mixture was then maintained at 65°C for 90 minutes, and samples of the reaction medium were taken for different holding times and analyzed to determine part A (see [link to example]). Figure 2 ).

[0301] according to Figure 2 It can be inferred that, for test #2 according to Example 1, the step of contacting to form a premix and holding it at T1 for a holding time of 10 minutes allows the reaction medium to reach less than about 20% of portion A. This shows that although polymerization can be maintained at T1 until the desired degree of polymerization is reached, it may be advantageous to raise the temperature of the reaction medium to temperature T2 to reach the desired degree of polymerization more quickly, while benefiting from the technical advantages of the present invention (low proportion of low molecular weight molecules and powder form).

[0302] Example 3

[0303] Extraction of fraction B of the polymer obtained according to Test #3 was performed for 144 hours in dichloromethane under stirring at 35°C. The mixture of polymer and dichloromethane extract was then drained, washed in situ with dichloromethane, followed by washing with water at 30°C, and finally dried.

[0304] The polymer extracted thus had a B fraction of 3.81%. This shows that even under fairly stringent extraction conditions, it is virtually impossible to extract low-mass molecules, especially those with molecular weights between 500 g / mol and 3000 g / mol.

Claims

1. A method for manufacturing polyetherketoneketone, comprising: -The aromatic ether, acyl chloride, Lewis acid and the first part s1 of the reaction solvent are brought into contact at a temperature T0 less than or equal to 25°C to form a premix, wherein the aromatic ether is diphenyl ether, 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or a mixture thereof, and the acyl chloride is isophthaloyl chloride, terephthaloyl chloride or a mixture thereof; -Optionally, the formed premix is ​​held at T0; -The premix formed at T0 is contacted with a portion s2 of the reaction solvent to form a reaction mixture at a temperature T1 ranging from 40°C to 80°C, wherein the portion s2 of the reaction solvent is preheated; and -Optionally, the resulting reaction mixture is kept at T1.

2. The method according to claim 1, wherein the reaction solvent is selected from: o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene, and mixtures thereof.

3. The method according to any one of claims 1 and 2, wherein the reaction solvent is o-dichlorobenzene.

4. The method according to any one of claims 1 to 3, wherein the Lewis acid is selected from: aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, tin chloride, titanium tetrachloride, and molybdenum pentachloride and mixtures thereof.

5. The method according to any one of claims 1 to 4, wherein the Lewis acid is aluminum trichloride.

6. The method according to any one of claims 1 to 5, wherein the aromatic ether is substantially composed of 1,4-bis(4-phenoxybenzoyl)benzene or composed of 1,4-bis(4-phenoxybenzoyl)benzene.

7. The method according to any one of claims 1 to 6, wherein s2 ≥ 0.

25.

8. The method according to any one of claims 1 to 7, wherein s1 ≥ 0.

25.

9. The method according to any one of claims 1 to 8, wherein s1+s2≥0.

75.

10. The method according to any one of claims 1 to 9, wherein s1 + s2 = 1.

11. The method according to any one of claims 1 to 10, wherein T1 ranges from 40°C to 52°C.

12. The method according to any one of claims 1 to 10, wherein T1 ranges from 52°C to 60°C.

13. The method according to any one of claims 1 to 10, wherein T1 ranges from 60°C to 68°C.

14. The method according to any one of claims 1 to 10, wherein T1 ranges from 68°C to 80°C.

15. The method according to any one of claims 1 to 14, wherein the reaction mixture is brought to T1 and optionally maintained at T1 until the resulting reaction mixture has a fraction of less than or equal to 50%, preferably less than or equal to 25%, and even more preferably less than or equal to 15% of a molecular weight fraction strictly less than 500 g / mol in PMMA equivalent.

16. The method according to any one of claims 1 to 15, wherein after the step of forming the reaction mixture at temperature T1 and optionally maintaining it at temperature T1, the reaction medium is brought to a temperature T2 ranging from 120°C to at least 10°C higher than T1 and optionally maintained at temperature T2.

17. The method according to any one of claims 1 to 16, comprising the step of purifying the mixture of products obtained at the end of polymerization.

18. The method according to any one of claims 1 to 17, wherein the chain restrictor is added prior to the step of forming the reaction mixture reaching temperature T1.

19. The method according to any one of claims 1 to 18, wherein the molar ratio of the aromatic ether to the reaction solvent that has been totaled in the reaction mixture is: 0.005 to 0.030, preferably: 0.008 to 0.025, and very preferably: 0.010 to 0.

022.

20. The method according to any one of claims 1 to 19, wherein the premix formed at T0 is dispersed in all or part of a portion of a preheated reaction solvent portion s2 to form a reaction mixture reaching T1.

21. The method according to any one of claims 1 to 20, wherein the step of contacting the premix with a portion s2 of the reaction solvent is carried out under stirring, and preferably using a dual-flow stirring apparatus.

22. The method according to any one of claims 1 to 21, wherein the polyether ketone obtained by the method comprises repeating units of formula (I) and formula (II), wherein the ratio of units of formula (II) to units of formula (I) is 55:45 to 95:5, and the units of formula (I) have the following chemical formula: [Chemical Formula 14] (I)， The unit of formula (II) has the following chemical formula: [Chemical Formula 15] (II)。 23. A polyether ketone ketone, comprising three molecular weight fractions A, B, and C, wherein A represents the percentage fraction of molecular weight strictly below 500 g / mol in PMMA equivalent, B represents the percentage fraction of molecular weight in the range of 500 g / mol to 3000 g / mol in PMMA equivalent, and C represents the percentage fraction of molecular weight strictly above 3000 g / mol in PMMA equivalent, characterized in that: A+B≤5.0% and A+B+C=100%.

24. The polyether ketone ketone according to claim 23, wherein B ≤ 4.0%, preferably B ≤ 3.5%, and more preferably B ≤ 3.3%.

25. The polyetherketone according to any one of claims 23 and 24, having an intrinsic viscosity greater than or equal to 0.4 dl / g, preferably greater than or equal to 0.5 dl / g, preferably greater than or equal to 0.6 dl / g, and more preferably greater than or equal to 0.7 dl / g; and / or It has an intrinsic viscosity of less than or equal to 2 dl / g, and preferably less than or equal to 1.5 dl / g; The intrinsic viscosity was measured at 0.0005 g / mL in 96.00% sulfuric acid solution at 25°C using an Ubbelohde type suspension surface viscometer according to standard ISO 307-2009.

26. The polyether ketone according to any one of claims 23 to 25, comprising repeating units of formula (I) and formula (II), wherein the ratio of units of formula (II) to units of formula (I) is 55:45 to 95:5, and the units of formula (I) have the following chemical formula: [Chemical Formula 16] (I)， The unit of formula (II) has the following chemical formula: [Chemical Formula 17] (II)。 27. The polyetherketone according to any one of claims 23 to 26, wherein it does not contain any dispersant.

28. The polyetherketone powder according to any one of claims 23 to 27, wherein the mass proportion of particles having a size strictly greater than 1000 micrometers obtained by sieving using a sieve with a sieve aperture size equal to 1 mm is less than or equal to 50%.

29. The polyether ketone powder according to claim 28, wherein the mass proportion of particles with a size range of 315 micrometers to 1000 micrometers is greater than or equal to 50%, and preferably greater than or equal to 80%.

30. The polyetherketone powder according to any one of claims 28 and 29, wherein the mass percentage of particles having a size strictly greater than 1000 micrometers is less than or equal to 10%, and preferably less than or equal to 5%.

31. The polyetherketone powder according to any one of claims 28 to 30, wherein the mass percentage of particles having a size strictly less than 315 micrometers is less than or equal to 10%.

32. The polyether ketone powder according to claim 28, wherein the mass percentage of particles strictly smaller than 630 micrometers is greater than or equal to 50%, preferably greater than or equal to 70%, and more preferably greater than or equal to 85%.

33. The polyetherketone powder according to any one of claims 28 to 32, having a concentration of 180 kg / m³ or greater. 3 And less than or equal to 400 kg / m 3 The tap density.

34. The polyetherketone ketone according to any one of claims 22 to 27 or the powder according to any one of claims 28 to 33, obtained by the method according to any one of claims 1 to 22.

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