Polyetherketoneketone manufacturing process

Abstract

The invention relates to a process for manufacturing a polyetherketoneketone comprising: - contacting an aromatic ether or a mixture of aromatic ethers, comprising at least 50% by moles of 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or their mixture, relative to the total number of moles of aromatic ether(s), with an acyl chloride or a mixture of acyl chlorides, and a Lewis acid, in all or part of a reaction solvent, so as to form a reaction mixture, the 1,3-bis(4-phenoxybenzoyl)benzene and / or the 1,4-bis(4-phenoxybenzoyl)benzene being essentially insolubilized in the reaction solvent at the end of the contacting step; and, - the polymerization of the reaction mixture, the polymerization being carried out, at least in part, at a temperature Tp greater than or equal to 50 °C;The process is characterized in that it comprises a progressive heating step of the reaction mixture until an acceleration of the polymerization reaction is achieved, the progressive heating step being carried out at an average heating rate chosen from a range of 0.65°C / minute to 2.5°C / minute; one or more chain-limiting agents being optionally added during the process. Figure for the abstract: Figure 1;

Description

Title of the invention: Process for the manufacture of polyetherketo-neketone Technical field

[0001] The invention relates to the field of polyetherketoneketones.

[0002] More particularly, the invention relates to a process for manufacturing polyether ketone ketone by precipitating polymerization, carried out electrophilically.

[0003] The invention also relates to the polymer capable of being obtained by this process. Prior art

[0004] It is known, in particular from US 3,791,890, a process for the electrophilic manufacture of polyetheretherketone from a mixture of isophthaloyl chloride and terephthaloyl chloride (acyl chlorides), reacted with diphenyl ether (aromatic ether), in the presence of aluminum chloride (Lewis acid), and using ortho-dichlorobenzene as reaction solvent.

[0005] Example 3 of US 3,791,890 describes the preparation of a premixture comprising acyl chlorides, diphenyl ether and aluminum chloride in a small amount of ortho-dichlorobenzene (350 mL) at a temperature of about -5°C. The reaction is then initiated by dispersing this premixture in a large amount of ortho-dichlorobenzene (1250 mL) preheated to 100°C.

[0006] This sequence of first preparing a cold premix and then dispersing the premix in preheated reaction solvent allows for an extremely rapid temperature rise of the reaction mixture. Although the mechanisms occurring in the reaction medium are not fully understood, US 3,791,890 indicates that this allows: separating the polymer particles being formed, facilitating the polymerization reaction, and preventing the coagulation of the particles into a gelatinous mass characteristic of this polymerization reaction.

[0007] It is also known, in particular from example 3 of US 4,816,556, that the sequence of preparing a cold premix and then dispersing the latter in preheated reaction solvent can also be implemented in an alternative electrophilic process for manufacturing polyetheretherketone, in which 1,4-bis(4-phenoxybenzoyl)benzene (aromatic ether) is reacted with an acyl chloride, in the presence of aluminum chloride, and using ortho-dichlorobenzene as the reaction solvent.

[0008] Furthermore, Example 3 of US 4,816,556 includes the use of benzoyl chloride allowing the molecular weight of the polymer obtained to be controlled.

[0009] In practice, the methods of the two patent documents above have not proven to be completely effective and only partially prevent the deposition of a gelatinous mass during polymerization on the walls of the reactor and on the stirring system, which leads to several disadvantages.

[0010] Firstly, this causes a reduction in the efficiency of the process since this gel is difficult to recover. Secondly, this makes the control of the polymerization reaction more complicated since it can lead to a drift in the stoichiometry of the reactants. Thirdly, the fouling of the walls reduces the efficiency of the heat transfer between the temperature control means of the reactor and the reaction medium, making the control of the temperature within the reactor more complicated. Fourthly, this requires the implementation of an often tedious cleaning of the reactor which leads to a reduction in the productivity of the installations while generating liquid and solid effluents to be recycled and / or destroyed.

[0011] Furthermore, the sudden increase in the temperature of the reaction medium implies poor control, at least temporarily, of the latter, which makes good repeatability of the process difficult.

[0012] Furthermore, as demonstrated in the experimental part of the present application, the polymer obtained using processes according to the two patent documents above, is in the form of large particles of fairly heterogeneous sizes, which in particular makes the purification steps more complicated to implement.

[0013] Finally, as demonstrated in the experimental part of the present application, the method according to the two patent documents above does not make it possible to obtain good integration of the chain limiting agent at the end of the polymer chains for a given polymer viscosity.

[0014] It is also known, in particular from WO 9 523 821, the addition of a polymer dispersant making it possible to prevent the coagulation of a sticky polymer product.

[0015] This document explains that the sticky polymer product is in fact due to the complex formed by a low molecular weight polymer with the Lewis acid formed at the beginning of the polymerization reaction and which precipitates in the form of a gel which covers the walls of the reactor and the stirrer.

[0016] Among the dispersants, the patent document designates for example compounds having as a group a fraction of formula:

[0017] [Chem.l]

[0018] The addition of a dispersant nevertheless has several disadvantages. The use of certain dispersants, in particular those having a fraction of formula (0) as illustrated above, results in overconsumption of Lewis acid in the process, the latter also forming a complex with the dispersant. In addition, this complicates the management of process effluents, and in particular the exploitation / recycling of the effluent containing Lewis acid.

[0019] Finally, still with the aim of avoiding the phenomenon of coagulation and fouling of the reactor, document EP 3 712 193 proposes a process in which an inert gas, in particular nitrogen, is blown into the reaction medium during the polymerization reaction. This can in certain cases be detrimental to fine control of the temperature in the reaction medium and therefore to good repeatability of the process.

[0020] Thus, there is currently a need to improve the process for manufacturing polyetherketoneketone in order to further limit fouling caused by, according to current knowledge, the coagulation of oligomer-Lewis acid complex. There is also a need to provide a manufacturing process that is simpler and / or has good repeatability and / or has a better yield and / or is more efficient.

[0021] The present invention provides such a process which preferentially overcomes one or more disadvantages of the processes according to the prior art, as well as polymers capable of being obtained by this process. Objectives of the invention

[0022] An objective of the invention is, at least according to certain embodiments, to propose a method which is simple to implement and makes it possible to effectively limit fouling of the polymerization reactor.

[0023] Another objective of the invention is, at least according to certain embodiments, to increase the yield of the process for manufacturing polyetherketoneketone.

[0024] Another objective of the invention is, at least according to certain embodiments, to increase the efficiency of the process for manufacturing polyetherketoneketone, in particular allowing less frequent cleaning of the reactor.

[0025] Another objective of the invention is, at least according to certain embodiments, to propose a method allowing optimal control of the reaction parameters, in particular of the temperature inside the reactor.

[0026] Another objective of the invention is, at least according to certain embodiments, to propose a method allowing optimal control of the degree of polymerization, which is measured indirectly but in the usual manner by evaluating the viscosity of the polymer produced.

[0027] Another objective of the invention is, at least according to certain embodiments, to propose a method allowing optimal control of the chemistry of the chain ends of the polymer produced.

[0028] Another objective of the invention is, at least according to certain embodiments, to obtain polymer particles of more homogeneous size and / or of smaller size. Summary of the invention

[0029] The invention relates to a method for manufacturing a polyetherketoneketone comprising:

[0030] - bringing into contact an aromatic ether or a mixture of aromatic ethers, comprising at least 50 mol% of l,3-bis(4-phenoxybenzoyl)benzene, l,4-bis(4-phenoxybenzoyl)benzene or their mixture, relative to the total number of moles of aromatic ether(s), with an acyl chloride or a mixture of acyl chlorides, and a Lewis acid, in all or part of a reaction solvent, so as to form a reaction mixture. The l,3-bis(4-phenoxybenzoyl)benzene and / or the l,4-bis(4-phenoxybenzoyl)benzene are essentially unsolubilized in the reaction solvent at the end of the contacting step; and,

[0031] - the polymerization of the reaction mixture, the polymerization being carried out, at least in part, at a temperature Tp greater than or equal to 50°C.

[0032] The process is characterized in that it comprises a progressive step of heating the reaction mixture until an acceleration of the polymerization reaction is achieved,

[0033] the progressive heating step being implemented at an average heating rate chosen in a range from 0.65°C / minute to 2.5°C / minute.

[0034] Among the chemical species introduced during the process, in particular during the contacting step and / or during the polymerization, and / or during the progressive heating step, one or more chain-limiting agents may optionally be added.

[0035] According to certain embodiments, the acyl chloride(s) are chosen from the group consisting of: terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, phosgene, adipoyl dichloride, tetrabromophthaloyl chloride, and compounds having the chemical formula:

[0036] [Chem. 2]

[0037] [Chem. 3] o [Chem. 4]

[0038]

[0039] [Chem. 5]

[0040]

[0041] (HIV) [Chem. 6] [Chem. 7]

[0042] [Chem. 8]

[0043] [Chem.9]

[0044] in which: a is an integer ranging from 0 to 3; V is selected from: -O-, -S-, -(CF2)q-, -(CH2)q-, or -C((CH3)2)-; Z is selected from: -C(O)-, -SO2-, -C(O)-C6H4-C(O)-, -O-(CF2)qO-, -S-, -(CF2)q-, -(CH2)q-, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20.

[0045] According to certain embodiments, a mixture of aromatic ethers is used. This mixture comprises in addition to an aromatic ether selected from the group consisting of: 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene, or a mixture thereof, at least one other aromatic ether selected from the group consisting of:

[0046] diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone,

[0047] the products of the Friedel-Crafts electrophilic substitution reaction of two molecules, in particular two same molecules, chosen from: diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone with an acyl chloride molecule selected from: phthaloyl chloride, phosgene, adipoyl dichloride, and compounds having the chemical formula:

[0048] [Chem. 10]

[0049] [Chem. 11]

[0051] [Chem. 13] o (vm)

[0052] [Chem. 14] [Chem. 15]

[0053] (vni)

[0054] [Chem. 16]

[0055] [Chem. 17]

[0056] oo (X) [Chem. 18]

[0057] [Chem. 19]

[0058]

[0059] in which: a is an integer ranging from 0 to 3; V is selected from: -O-, -S-, -(CF2)q-, -(CH2)q-, or -C((CH3)2)-; Z is selected from: -C(O)-, -SO2-, -C(O)-C6H4-C(O)-, -O-(CF2)qO-, -S-, -(CF2)q-, -(CH2)q-, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20; and, the products of the Friedel-Crafts electrophilic substitution reaction of two molecules, in particular two of the same molecules, chosen from: 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, and 3,4'-diphenoxybenzophenone with an acyl chloride molecule chosen from: terephthaloyl chloride and isophthaloyl chloride. According to some embodiments, the reaction solvent is selected from the group

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] consisting of: ortho-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, ortho-difluorobenzene, and mixtures thereof. In some embodiments, the Lewis acid is selected from the group consisting of: aluminum trichloride, aluminum 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. According to some embodiments, at least one chain limiting agent is added during the process. The chain-limiting agent may be a nucleophilic chain-limiting agent. The latter is preferably chosen from compounds with the following chemical formula: [Chem. 20] in which: Xi represents a covalent bond, -O-, or -S-, and X2 represents, C6H5CO, or C6H5SO2; and, [Chem.21] in which: X3 represents a halogen atom, an alkyl group, or an alkoxy group having 1 to 10 carbon atoms; Alternatively, or in addition, the chain-limiting agent may be an electrophilic chain-limiting agent. The latter is preferably chosen from compounds of the following formula: [Chem. 22]

[0069] [Chem.23]

[0070] in which: X4 represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 10 carbon atoms, a nitro group, C6H5CO or C6H5SO2.

[0071] According to certain embodiments, the molar ratio of aromatic ether(s) relative to the reaction solvent(s) having been introduced in total into the reaction mixture at the end of the polymerization is: 0.005 to 0.030, preferably: 0.008 to 0.025, and extremely preferably: 0.010 to 0.022.

[0072] According to certain embodiments, an excess of aromatic ether(s) is reacted with the acyl chloride(s). Advantageously, the molar ratio of aromatic ether(s) to the acyl chloride(s) having been introduced in total into the reaction mixture at the end of the contacting step is preferably: 1.001 to 1.1.

[0073] According to certain embodiments, the molar ratio of Lewis acid(s) relative to the aromatic ether(s) having been introduced in total into the reaction mixture at the end of the contacting step is: 5.0 to 7.0 and preferably: 5.5 to 6.5.

[0074] According to certain embodiments, the reaction mixture is maintained during the contacting step at a temperature To less than or equal to 5°C, preferably less than or equal to 0°C, and more preferably less than or equal to -5°C.

[0075] According to certain embodiments, the temperature Tp is less than or equal to 120°C; and preferably less than or equal to 100°C.

[0076] According to certain embodiments, the progressive heating step and the polymerization are carried out with stirring, preferably using a stirring means comprising at least one double-flow rotor.

[0077] According to certain embodiments, a mixture of aromatic ethers is used to carry out the method. This mixture of aromatic ethers consists of an aromatic ether selected from: 1,4-bis(4-phenoxybenzoyl)benzene, 1,3-bis(4-phenoxybenzoyl)benzene or a mixture thereof; and another aromatic ether selected from: diphenyl ether, 4,4'-diphenoxybenzophenone, or a mixture thereof. The mixture of aromatic ethers comprises up to 20 mol%, preferably up to 10 mol%, and more preferably up to 5 mol% of said other aromatic ether, relative to the total number of moles of aromatic ethers.

[0078] According to certain embodiments, the aromatic ether or where appropriate the mixture of aromatic ethers consists of, or is respectively essentially consisting of, 1,4-bis(4-phenoxybenzoyl)benzene.

[0079] According to certain embodiments, the acyl chloride(s) are selected from the group consisting of isophthaloyl chloride, terephthaloyl chloride, and a mixture thereof.

[0080] According to certain embodiments, the Lewis acid is aluminum trichloride.

[0081] According to certain embodiments, the reaction solvent is ortho-dichlorobenzene.

[0082] According to certain embodiments, a chain limiting agent is added during the process. This chain limiting agent is benzoyl chloride, p-fluorobenzoyl chloride, or a mixture thereof.

[0083] According to certain embodiments, the progressive heating step is implemented at an average heating rate ranging from 0.70°C / minute to 2.2°C / minute, preferably at an average heating rate ranging from 0.75°C / minute to 2.0°C / minute, and more preferably at an average heating rate ranging from 0.8°C / min to 1.8°C / min.

[0084] According to certain embodiments, a mass fraction of reaction solvent at least equal to 0.15 is introduced before the end of the contacting step, the mass fraction being calculated by dividing the weight of reaction solvent having been introduced at the end of the contacting step relative to the total weight of reaction solvent having been introduced at the end of the polymerization.

[0085] The present invention also relates to a polyetherketoneketone having chain ends controlled by a chain limiter, verifying the following inequality:

[0086] IV *FDC(LDC) > LIM; (eq. 1)

[0087] in which: IV represents the inherent viscosity of the polymer, expressed in dl / g, as measured according to ISO 307-2009 applied to PEKK; FDC(LDC) represents the molar concentration of the group resulting from the chain limiter relative to the total weight of the polymer, expressed in micro equivalents of chain limiter per gram of polymer; LIM is a number equal to at least 40.

[0088] This polymer can be obtained by an electrophilic process, in particular by the electrophilic process according to the invention.

[0089] According to certain embodiments, the chain limiter is a nucleophilic chain limiting agent chosen from the compounds of the following chemical formula: [Chem. 24]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] in which: Xi represents a covalent bond, -O-, or -S-; and X2 represents, C6H5CO, or C6H5SO2; and, [Chem. 25] in which: X3 represents a halogen atom, an alkyl group or an alkoxy group having 1 to 10 carbon atoms; or, the chain limiter is an electrophilic chain limiting agent selected from the compounds of the following formula: [Chem.26] (XVI) in which: X4 represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 10 carbon atoms, a nitro group, C6H5CO or C6H5SO2. In some embodiments, the chain limiter is benzoyl chloride, p-fluorobenzoyl chloride, or a mixture thereof. According to certain embodiments, the polyetherketoneketone has an inherent 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, the inherent viscosity being measured at a concentration of 0.0005 g / mL in a 96.00% sulfuric acid solution at 25°C using a suspended level Ubbelohde type viscometer according to ISO 307-2009.

[0099] Alternatively, or in a complementary manner, the polyetherketoneketone has an inherent viscosity less than or equal to 2 dl / g, and preferably less than or equal to 1.5 dL / g.

[0100] According to some embodiments, the polyetherketoneketone has an inherent viscosity ranging from 0.98 dL / g to 1.4 dL / g.

[0101] According to certain embodiments, the polyetherketoneketone according to the invention is in the form of a powder characterized in that the mass proportion of particles of size strictly greater than 630 micrometers is less than or equal to 25%, preferably less than or equal to 15%, more preferably less than or equal to 10%, more preferably still less than or equal to 5%, and most preferably less than or equal to 2%, as obtained by sieving using a sieve with a mesh size equal to 630 micrometers.

[0102] According to certain embodiments, the polyetherketoneketone according to the invention is in the form of a powder characterized in that the mass proportion of particles of size strictly greater than 450 micrometers is less than or equal to 75%, preferably less than or equal to 50%, more preferably less than or equal to 25%, more preferably still less than or equal to 20%, and most preferably less than or equal to 16%, as obtained by sieving using a sieve with a mesh size equal to 450 micrometers. Detailed description of the invention

[0103] The polyetherketoneketones, also called PEKK, prepared according to the process of the invention comprise at least 25 mol%, relative to the total number of moles of repeating units of the polymer, of a repeating unit chosen from the group consisting of:

[0104] [Chem.28] (I), also referred to as the isophthalic motif or by the initial “I”;

[0105] [Chem.29] (II), also referred to as the terephthalic unit or by the initial “T”; and,

[0106] their mixture.

[0107] The polyetherketonesketones manufactured according to the invention may comprise at least 30 mol%, or at least 40 mol%, or at least 50 mol%, or at least 60 mol%, or at least 70 mol%, or at least 80 mol%, or at least 90 mol%, or 100% of the repeating units of formula (I) and / or formula (II) relative to the total number of moles of the repeating units of the polymer.

[0108] According to the embodiments where the polyetherketoneketone comprises repeating units of formula (I) and formula (II), these units are considered as a whole relative to the total number of moles of repeating units of the polymer.

[0109] According to certain embodiments, the polyetherketones according to the invention are essentially constituted, that is to say comprise at least 95 mol%, preferably at least 98 mol%, of the repeating units of formula (I) and / or of formula (II), considered where appropriate as a whole, relative to the total number of moles of the repeating units of the polymer.

[0110] According to certain embodiments, the polyetherketones according to the invention consist of repeating units of formula (I) and / or of formula (II).

[0111] According to certain embodiments, the polyetherketonesketones according to the invention are essentially constituted, or constituted, of repeating units of formula (I) and / or of formula (II), the proportion of units of formula (II) relative to the units of formula (I), noted ratio T:I being from 50:50 to 100:0. In particular the ratio T:I can be from 50:50 to 55:45, or from 55:45 to 65:35, or from 65:35 to 75:25, or from 75:25 to 85:15, or from 85:15 to 95:5, 95:5 to 100:0.

[0112] According to certain embodiments, the polyetherketones according to the invention are essentially constituted, or constituted, of repeating units (I) and / or (II), with a T:I ratio of 0:100 to 50:50. In particular, the T:I ratio may be from 0:100 to 5:95, or from 5:95 to 10:90, or from 10:90 to 20:80, or from 20:80 to 30:70, or from 30:70 to 40:60, or from 40:60 to 50:50.

[0113] The polymerization reaction involved is a polycondensation reaction involving an electrophilic substitution between one or more aromatic ethers with one or more acyl chlorides, in the presence of a Lewis acid and optionally a chain limiting agent in a reaction solvent. The polymerization reaction is furthermore precipitating because the polymer formed precipitates in the reaction mixture. Finally, it is exothermic. Hydrogen chloride is produced during the polycondensation.

[0114] Without being bound by theory, the inventors believe that the implementation of the process according to the invention, in particular the contacting of the reactants so as to form a reaction mixture in which the l,3-bis(4-phenoxybenzoyl)benzene and / or the l,4-bis(4-phenoxybenzoyl)benzene remain essentially in suspension, followed by a progressive heating step, makes it possible to create a metastable state of the reaction mixture in which the l,3-bis(4-phenoxybenzoyl)benzene and / or the l,4-bis(4-phenoxybenzoyl)benzene is / are essentially in suspension. Maintaining l,3-bis(4-phenoxybenzoyl)benzene and / or l,4-bis(4-phenoxybenzoyl)benzene, if appropriate taken together, in a non-soluble form in the reaction mixture for a sufficiently long time allows the acceleration of the polymerization reaction to take place at a higher temperature than under conditions where thermodynamic equilibrium would be allowed to establish itself.This makes it possible to initiate the polymerization reaction with rapid kinetics and therefore to limit the duration during which the reaction mixture is essentially formed of low molecular weight polymer chains, these polymer chains being particularly capable of coagulating and forming a gel fouling the walls of the reactor and / or the stirring system.

[0115] Essentially "suspended" or "essentially unsolubilized" means that the 1,3-bis(4-phenoxybenzoyl)benzene and / or the 1,4-bis(4-phenoxybenzoyl)benzene, where appropriate considered as a whole, have a mass fraction of less than 2%, preferably less than 1%, more preferably less than 0.5%, more preferably less than 0.25%, and most preferably less than 0.1% of solubilized species in the reaction solvent relative to the total weight of species in the reaction solvent at a given time and at a given temperature.

[0116] The acyl chloride is preferably chosen from the group consisting of: terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, phosgene, adipoyl dichloride, and compounds having the formula:

[0117] [Chem.30]

[0118] [Chem.31]

[0121] [Chem.34]

[0123] [Chem.36]

[0124] [Chem.37]

[0125] in which: a is an integer ranging from 0 to 3; V is selected from: -O-, -S-, -(CF2)q-, -(CH2)q-, or -C((CH3)2)-; Z is selected from: -C(O)-, -SO2-, -C(O)-C6H4-C(O)-, -O-(CF2)qO-, -S-, -(CF2)q-, -(CH2)q-, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20.

[0126] A number of measures can be taken to ensure that the acyl chloride(s) used have a satisfactory degree of purity. Indeed, acyl chlorides are easily hydrolyzable species and may in particular contain as impurities a certain quantity of hydrolyzed species if they are not stored and / or handled under appropriate conditions.

[0127] In particular, the acyl chlorides must not be brought into contact at any time with water and / or a humid atmosphere before being introduced into the reactor. It may thus be advantageous to store the acyl chlorides in a sealed container without contact with the ambient air, or alternatively in a container containing dry air. Advantageously, the acyl chlorides may be kept under a dry nitrogen atmosphere before being introduced into the reactor in order to avoid any contact with the ambient air.

[0128] The hydrolyzed forms of acyl chlorides are difficult to analyze and quantify. It has been found that a practical and rapid method for ensuring the purity level of acyl chlorides is to dissolve them in a solvent, in particular a reaction solvent, for example ortho-dichlorobenzene, and to analyze the turbidity of the mixture. Indeed, a high turbidity value obtained by this test indicates a high quantity of insoluble contaminants, mainly the hydrolyzed forms.

[0129] Accordingly, the acyl chloride or mixture of acyl chlorides used is preferably such that, 10 minutes after introducing it at a reference concentration of 6.5% by weight into anhydrous reaction solvent, at a temperature of 20°C, the mixture obtained has a turbidity of less than 500 NTU (nephthalometric turbidity unit). The turbidity values ​​are given with reference to a solvent sample not comprising acyl chloride.

[0130] According to certain embodiments, the acyl chloride or the mixture of acyl chlorides used is preferably such that, 10 minutes after having introduced it at a reference concentration of 6.5% by weight in anhydrous reaction solvent, at a temperature of 20°C, the mixture obtained has a turbidity of less than 200 NTU, preferably less than 100 NTU, very preferably less than 50 NTU, and more preferably less than 20 NTU.

[0131] According to embodiments where the polyetherketoneketone consists essentially of, or consists of, the repeating units of formula (I) and / or (II), the acyl chloride or the mixture of acyl chlorides consists essentially of, or consists of, terephthaloyl chloride, isophthaloyl chloride or a mixture of terephthaloyl chloride and isophthaloyl chloride.

[0132] The aromatic ether is 1,3-bis(4-phenoxybenzoyl)benzene or 1,4-bis(4-phenoxybenzoyl)benzene or a mixture of aromatic ethers comprising at least 50 mol% of an aromatic ether chosen from:

[0133] l,3-bis(4-phenoxybenzoyl)benzene of formula:

[0134] [Chem.38] (III)

[0135] l,4-bis(4-phenoxybenzoyl)benzene of formula:

[0136] [Chem.39] ___________ O ________, O ____________ __________x / —\ Z— \ Z ù N % - / > % 4 7—7—\ ü 7 (IV)

[0137] or their mixture; relative to the total number of moles of aromatic ether(s).

[0138] In the case where the mixture of aromatic ethers comprises a mixture of l,3-bis(4-phenoxybenzoyl)benzene and l,4-bis(4-phenoxybenzoyl)benzene, the mixture of aromatic ethers comprises at least 50 mol% of l,3-bis(4-phenoxybenzoyl)benzene and l,4-bis(4-phenoxybenzoyl)benzene taken as a whole relative to the total number of moles of aromatic ethers.

[0139] According to certain embodiments, the aromatic ether or the mixture of aromatic ethers comprises at least 60%, or at least 70%, or at least 80%, or at least 90%, or at least 95% by mole 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 aromatic ether(s).

[0140] According to certain embodiments, a mixture of aromatic ethers is used comprising in addition to an ether chosen from 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene, another aromatic ether chosen from the list consisting of: diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone, or the product of the Friedel-Crafts electrophilic substitution reaction of two molecules, in particular two same molecules, chosen from: diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone with an acyl chloride molecule, the acyl chloride preferably being chosen from the list previously described (except the isophthaloyl or terephthaloyl chloride in the case of diphenyl ether since the reaction gives l,3-bis(4-phenoxybenzoyl)benzene and, respectively, l,4-bis(4-phenoxybenzoyl)benzene).

[0141] According to certain embodiments, a mixture of aromatic ethers is used. It consists of: 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene, considered where appropriate as a whole, and: diphenyl ether and / or 4,4'-diphenoxybenzophenone. The mixture may comprise up to 20 mol%, preferably up to 10 mol% and more preferably up to 5 mol% of diphenyl ether and / or 4,4'-diphenoxybenzophenone, considered where appropriate as a whole, relative to the total number of moles of aromatic ethers.

[0142] The presence of diphenyl ether and / or 4,4'-diphenoxybenzophenone in addition to: l,3-bis(4-phenoxybenzoyl)benzene and / or l,4-bis(4-phenoxybenzoyl)benzene makes it possible to increase the ratio of ether groups to ketone groups in the polymer, in comparison with embodiments where only l,3-bis(4-phenoxybenzoyl)benzene and / or l,4-bis(4-phenoxybenzoyl)benzene are used.

[0143] According to certain embodiments, a mixture of aromatic ethers is used. It consists of: 1,3-bis(4-phenoxybenzoyl)benzene and / or 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 extremely preferably up to 1 mol% of diphenyl ether relative to the total number of moles of aromatic ethers.

[0144] According to certain embodiments, a mixture of aromatic ethers is used. It consists of 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene.

[0145] According to certain 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 extremely preferably up to 1 mol% of diphenyl ether, relative to the total number of moles of aromatic ethers.

[0146] According to certain embodiments, the aromatic ether is solely 1,4-bis(4-phenoxybenzoyl)benzene.

[0147] According to certain 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 extremely preferably up to 1 mol% of diphenyl ether, relative to the total number of moles of aromatic ethers.

[0148] According to certain embodiments, the aromatic ether is only 1,3 -bis (4-phenoxybenzoy Ijbenzene.

[0149] In some embodiments, the aromatic ether is solely 1,4-bis(4-phenoxybenzoyl)benzene. A polyetherketoneketone having a T:I ratio of 50:50 to 100:0 can be obtained by mixing isophthaloyl and terephthaloyl chlorides and adjusting the isophthaloyl chloride / terephthaloyl chloride ratio.

[0150] In some embodiments, the acyl chloride is solely terephthaloyl chloride. A polyetherketoneketone having a T:I ratio of 50:50 to 100:0 can be obtained by mixing 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene and adjusting the ratio 1,3-bis(4-phenoxybenzoyl)benzene / 1,4-bis(4-phenoxybenzoyl)benzene.

[0151] Similarly, according to certain embodiments, the aromatic ether is only l,3-bis(4-phenoxybenzoyl)benzene (respectively the acyl chloride is only isophthaloyl chloride). A polyetherketoneketone having a T:I ratio of 0:100 to 50:50 can be obtained by adjusting the ratio of isophthaloyl chloride / terephthaloyl chloride (respectively by adjusting the ratio l,3-bis(4-phenoxybenzoyl)benzene / l,4-bis(4-phenoxybenzoyl)benzene).

[0152] The Lewis acid may be selected from the group consisting of: aluminum trichloride, aluminum 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.

[0153] Preferably, only one type of Lewis acid is used in the polymerization reaction.

[0154] Among the Lewis acids cited above, aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, ferric chloride, gallium trichloride and molybdenum pentachloride are preferred.

[0155] Aluminum trichloride is particularly preferred.

[0156] Preferably, the Lewis acid is added in solid form. Alternatively, it may also be added in suspension or colloid form, i.e., as a heterogeneous mixture of solid Lewis acid particles in a solvent, or in solution form, i.e., as a homogeneous mixture in a solvent. The solvent of the suspension / colloid or solution is advantageously the reaction solvent.

[0157] According to certain variants, the Lewis acid is added in a particulate form, such as in powder form (having, for example, a Dv80 of less than 1 mm and preferably a Dv50 of less than 0.5 mm). The parameters Dv80 and Dv50 are respectively the particle sizes at the 80th and 50th percentiles (by volume) of the cumulative particle size distribution of the Lewis acid particles. These parameters can in particular be determined by sieving.

[0158] The Lewis acid used in the process according to the invention preferably has a degree of purity such that 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 gravimetry, when it is introduced with stirring into water at a concentration of 11% by weight at 20°C and substantially dissolved.

[0159] The reaction solvent may be selected from the group consisting of: ortho-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, ortho-di-fluorobenzene, and mixtures thereof.

[0160] Among the reaction solvents cited above, ortho-dichlorobenzene, trichlorobenzene, 1,2,3-trichlorobenzene, and ortho-difluorobenzene are preferred. Ortho-dichlorobenzene is particularly preferred.

[0161] The reaction solvent preferably contains less than 500 ppm by weight of water in order to limit the hydrolysis reaction of the acyl chloride or the mixture of acyl chlorides. Advantageously, the reaction solvent contains less than 250 ppm by weight of water, preferably less than 150 ppm by weight of water, more preferably less than 100 ppm by weight of water, and even more preferably less than 50 ppm by weight of water.

[0162] In preferred variants, the aromatic ether or the mixture of aromatic ethers also preferably contains less than 500 ppm by weight of water in order to limit the hydrolysis reaction of the acyl chloride or mixture of acyl chlorides. The same preferred value ranges as for the reaction solvent apply mutatis mutandis to the aromatic ether or mixture of aromatic ethers.

[0163] In more preferred variants, the reaction solvent and the aromatic ether or mixture of aromatic ethers comprise altogether less than 500 ppm by weight of water in order to limit the hydrolysis reaction of the acyl chloride or mixture of acyl chlorides. The same preferred value ranges as for the reaction solvent apply mutatis mutandis to the reaction solvent and the aromatic ether or mixture of aromatic ethers, considered as a whole.

[0164] In order to guarantee the absence of traces of water in the reactor, the process advantageously comprises a preliminary drying step, i.e. reduction of the water content, of the reaction solvent and / or of: the aromatic ether or of the mixture of aromatic ethers, before bringing them into contact with the acyl chloride or with the mixture of acyl chlorides. Means for implementing this preliminary drying step include, for example, distillation of the chemical compounds, or bringing them into contact with a molecular sieve or even bringing them into contact with a dehydrating agent such as a small quantity of aluminium chloride.

[0165] The use of one or more chain limiting agents in the reaction medium is optional. Their addition allows better control of the degree of polymerization and therefore the viscosity of the polymer to be manufactured. It also allows better control of the ends of the polymer chains, and where appropriate, ensures better stability, in particular better thermal stability, of the polymer.

[0166] An additional advantage of the process according to the invention compared to the processes of the prior art, in particular compared to those comprising the preparation of a cold premix and a dispersion of this premix in preheated reaction solvent, is that it makes it possible to obtain a polymer having a higher proportion at the end of polymer chains resulting from the chain-limiting agent for a given viscosity.

[0167] Two types of chain limiting agents can be used: a nucleophilic chain limiting agent or an electrophilic chain limiting agent.

[0168] According to certain embodiments, the chain-limiting agent is a nucleophilic chain-limiting agent. The nucleophilic chain-limiting agent may in particular be chosen from compounds of the following chemical formula:

[0169] [Chem.40]

[0170] in which: Xi represents: a covalent bond, -O-, or -S-; and X2 represents, C6H5CO, or C6H5SO2;

[0171] or of the following chemical formula:

[0172] [Chem.41]

[0173] in which: X3 is a halogen, an alkyl group or an alkoxy group having 1 to 10 carbon atoms.

[0174] Preferably, the nucleophilic chain limiting agent is chosen from the group consisting of: 4-phenoxybenzophenone, 4-phenoxydiphenylsulfone, anisole, fluo-robenzene, chlorobenzene, biphenyl, toluene, and their mixture.

[0175] A particularly advantageous nucleophilic chain limiting agent is 4-phenoxybenzophenone.

[0176] According to certain embodiments, the chain-limiting agent is an electrophilic chain-limiting agent. The electrophilic chain-limiting agent may in particular be chosen from the compounds of the following formula:

[0177] [Chem.42]

[0178] [Chem.43] (XVI)

[0179] in which: X4 represents: a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 10 carbon atoms, a nitro group, C6H5CO or C6H5SO2.

[0180] Preferably, the electrophilic chain limiting agent is chosen from the group consisting of: benzoyl chloride, acetyl chloride, 3,5-dichlorobenzoyl chloride, p-fluorobenzoyl chloride, p-chlorobenzoyl chloride, p-methoxybenzoyl chloride, benzene sulfonyl chloride, p-chlorobenzene sulfonyl chloride, p-methylbenzene sulfonyl chloride, 4-benzoyl-benzoyl chloride, and a mixture thereof.

[0181] Advantageously, the chain-limiting agent is an electrophilic chain-limiting agent, chosen from benzoyl chloride, p-fluorobenzoyl chloride, or a mixture thereof. These chain-limiting agents are easy to dose since they are in liquid form at room temperature, have a low cost and ensure good thermal stability for the polymer.

[0182] According to certain embodiments, a chain limiting agent being benzoyl chloride is used.

[0183] According to certain embodiments, a chain limiting agent being p-fluorobenzoyl chloride is used.

[0184] The use of a dispersing agent in the reaction medium is optional. The method according to the invention generally makes it possible to dispense with the use of such agents since it makes it possible to effectively minimize fouling within the reactor by increased control of the thermal properties within the reactor.

[0185] According to preferred embodiments, no dispersing agent is added to the reaction medium. This has several advantages in particular: it avoids overconsumption of the Lewis acid introduced and / or facilitates the recovery of the process effluents, in particular the effluent containing the Lewis acid.

[0186] The polymerization reaction being a polycondensation, the aromatic ether or the mixture of aromatic ethers is introduced into the reaction mixture under conditions which are substantially stoichiometric relative to the acyl chloride or the mixture of acyl chlorides.

[0187] The molar proportion of aromatic ether(s) relative to the acyl chloride(s) having been introduced in total into the reaction mixture at the end of the contacting step is preferably from 0.9:1.1 to 1.1:0.9.

[0188] According to advantageous embodiments, the aromatic ether(s) is / are introduced in excess relative to the acyl chloride(s), preferably with a molar ratio of aromatic ether(s) relative to the acyl chloride(s) 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 in a manner advantageously, benzoyl chloride or p-fluorobenzoyl chloride.

[0189] The molar ratio of aromatic ether(s) relative to the reaction solvent(s) having been introduced in total into the reaction mixture at the end of the polymerization is preferably at least equal to 0.005, very preferably greater than or equal to 0.008, and more preferably greater than or equal to 0.010.

[0190] As detailed below, the method according to the invention makes it possible to obtain polymer particles of a generally smaller size and with a generally more homogeneous distribution than the methods of the prior art comprising the preparation of a cold premix and then a dispersion of this premix in preheated reaction solvent. A more compact suspension of polymer particles in the reaction solvent can thus be obtained, which allows the method to be carried out in a generally smaller quantity of reaction solvent.

[0191] Thus, according to certain embodiments, the molar ratio of aromatic ether(s) relative to the reaction solvent(s) having been introduced in total into the reaction mixture at the end of the 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.

[0192] Conversely, given that the less solvent the reaction mixture contains, the more likely it will be to form fouling during the polymerization, especially in the absence of a dispersing agent, the molar ratio of aromatic ether(s) relative to the reaction solvent(s) having been introduced in total into the reaction mixture at the end of the 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.

[0193] Thus, according to certain embodiments, the molar ratio of aromatic ether(s) relative to the reaction solvent(s) introduced in total into the reaction mixture is from 0.005 to 0.030, preferably from 0.008 to 0.025, and extremely preferably from 0.010 to 0.022. The molar ratio of aromatic ether(s) to reaction solvent(s) introduced in total into the reaction mixture may in particular be 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.

[0194] The molar ratio of Lewis acid to the aromatic ether(s) having been introduced in total into the reaction mixture at the end of the contacting step is preferably from 5.0 to 7.0, and very preferably from 5.5 to 6.5.

[0195] The method according to the invention comprises bringing the chemical compounds into contact for the polymerization reaction. This step notably comprises bringing the reactants into contact: aromatic ether(s), acyl chloride(s), and Lewis acid, in all or part of the reaction solvent. These different compounds can in theory be mixed with each other in any order whatsoever, so that at the end of the contacting step the 1,3-bis(4-phenoxybenzoyl)benzene and / or the 1,4-bis(4-phenoxybenzoyl)benzene, considered as a whole where appropriate, are essentially not dissolved in the reaction solvent.

[0196] For the purposes of the invention, we speak of a "reaction mixture" from the moment when all or part of the aromatic ether(s), all or part of the acyl chloride(s) and all or part of the Lewis acid are brought into contact in all or part of the solvent. In other words, the "reaction mixture" begins to exist at the moment when a polymerization could be initiated, that is to say when all or part of the aromatic ether(s), all or part of the acyl chloride(s) and all or part of the Lewis acid have been brought into contact.

[0197] The contacting step ends when all of the aromatic ether or mixture of aromatic ethers, the acyl chloride or mixture of acyl chlorides and the Lewis acid have been contacted. Thus, the reaction mixture at the end of the contacting step comprises all of the aromatic ether or mixture of aromatic ethers, all of the acyl chloride or mixture of acyl chlorides, all of the Lewis acid, all or part of the reaction solvent, and optionally all or part of the chain limiter or mixture of chain limiters.

[0198] According to certain advantageous embodiments, the reaction mixture is maintained at a temperature To during the step of bringing the compounds into contact, so as to ensure that the 1,3-bis(4-phenoxybenzoyl)benzene and / or the 1,4-bis(4-phenoxybenzoyl)benzene, considered where appropriate as a whole, are essentially not dissolved in the reaction solvent at the end of the contacting step.

[0199] The temperature To is advantageously less than or equal to 5°C. It is preferably less than or equal to 0°C, and very preferably less than or equal to -5°C.

[0200] According to certain embodiments, all of the reaction solvent is introduced during the contacting step. This is particularly the case when the reaction solvent does not play a direct role in heating the reaction mixture until it reaches the temperature Tp.

[0201] According to other embodiments, only a portion of the reaction solvent is introduced during the contacting step, the other portion of the solvent being able to be, inter alia, added just after the end of the contacting and before, or at the beginning of, the progressive heating step. Alternatively, or in addition, the other portion of the solvent can be added during the progressive heating step to directly contribute to the implementation of this step. In other words, reaction solvent preheated to a temperature higher than the temperature of the reaction mixture can be added to the latter so as to increase its temperature.

[0202] According to certain embodiments, a mass fraction of 0.15 to 0.95 of solvent can be introduced before the end of the contacting step.

[0203] According to certain embodiments, a mass fraction of 0.15 to 0.25, or 0.25 to 0.40, or 0.40 to 0.55, or 0.55 to 0.70, or 0.70 to 0.85, or 0.85 to 0.95 of the reaction solvent may be introduced before the end of the contacting step.

[0204] According to advantageous embodiments, from 0.15 to 0.55, and preferably from 0.25 to 0.40, of the reaction solvent is introduced before the end of the contacting step. These embodiments make it possible in particular to ensure that the 1,3-bis(4-phenoxybenzoyl)benzene and / or the 1,4-bis(4-phenoxybenzoyl)benzene, considered as a whole, are essentially in the form of a suspension at the end of the contacting step.

[0205] According to advantageous embodiments, the different compounds, in particular the reagents, can be added in two phases.

[0206] In a first phase, two of the reactants are mixed in full. In a second phase, the third reactant is added in full to the previously obtained mixture. The medium can then be maintained at a temperature less than or equal to To between at the latest the start of the second phase where the third reactant begins to be added and the end of the second phase where the third reactant finishes being added.

[0207] According to a first embodiment, said first phase comprises the preparation of a mixture comprising all of the aromatic ether or the mixture of aromatic ethers with all of the acyl chloride or the mixture of acyl chlorides, in all or part of the reaction solvent. The second phase comprises the addition of all of the Lewis acid to the mixture obtained in the first phase.

[0208] According to a second embodiment, said first phase comprises the preparation of a mixture comprising all of the acyl chloride or the mixture of acyl chlorides with all of the Lewis acid, in all or part of the reaction solvent. The second phase comprises the addition of all of the aromatic ether or the mixture of aromatic ethers to the mixture obtained in the first phase.

[0209] The section below presents in detail these two particularly advantageous embodiments of implementing the step of bringing the chemical compounds into contact in a reactor. The method according to the invention is in no way limited to these embodiments given for illustrative purposes.

[0210] The first advantageous embodiment can be implemented according to the following sequence:

[0211] First, some or all of the reaction solvent is introduced into the reactor. Second, the aromatic ether or mixture of aromatic ethers is added and dispersed within the reaction solvent in the reactor under stirring. Third, in order to guarantee the absence of traces of water in the reactor, distillation is carried out as well as inerting the reactor headspace with nitrogen. Alternatively or in addition, a dehydrating agent, and in particular a small quantity of aluminum chloride, can be added in order to eliminate the last traces of water. The reaction of aluminum chloride with water forms an aluminum hydroxide and hydrogen chloride (according to this alternative, the medium already contains aluminum chloride in very small quantities, or even in trace amounts). Fourth, the acyl chloride or the mixture of acyl chlorides is introduced into the reactor under stirring. Fifth, the Lewis acid is introduced under stirring.Since the complexation of the Lewis acid with the acyl chloride(s) is an exothermic reaction, the Lewis acid is added slowly enough to the reactor so that the reaction mixture can be maintained at a temperature of 5°C or less. The Lewis acid addition step can generally last from 15 minutes to 12 hours. On an industrial scale, the Lewis acid addition step preferably lasts from 25 minutes to 6 hours, and more preferably from 30 minutes to 4 hours.

[0212] Once all of the Lewis acid has been completely introduced, an optional step of homogenizing the reaction mixture at a temperature less than or equal to To can be observed, if necessary. This optional homogenization step can preferably last less than 15 minutes, or less than 10 minutes, or less than 5 minutes.

[0213] The second advantageous embodiment can be implemented according to the following sequence:

[0214] First, part or all of the reaction solvent is introduced into the reactor. Second, in order to guarantee the absence of traces of water in the reactor, distillation is carried out as well as inerting the reactor headspace with nitrogen. Alternatively or in addition, a dehydrating agent, and in particular a small quantity of aluminum chloride, can be added so as to eliminate the last traces of water. The reaction of aluminum chloride with water forms an aluminum hydroxide and hydrogen chloride (according to this alternative, the medium already contains a very small quantity of aluminum chloride at this stage).

[0215] Third, the acyl chloride or mixture of acyl chlorides is introduced into the reactor with stirring. Fourth, the Lewis acid is introduced with stirring. Since the complexation of the Lewis acid with the acyl chloride(s) is an exothermic reaction, the Lewis acid is added slowly enough to the reactor so that the reaction mixture can be maintained at a temperature of 5°C or less. The Lewis acid addition step can generally last from 15 minutes to 12 hours. On an industrial scale, the Lewis acid addition step preferably lasts from 25 minutes to 6 hours, and more preferably from 30 minutes to 4 hours.

[0216] Fifth, once all of the Lewis acid has been fully introduced, the aromatic ether or mixture of aromatic ethers is introduced to form the reaction mixture.

[0217] An optional step of homogenization of the reaction mixture may be observed, if necessary. This optional homogenization step may preferably last less than 15 minutes, or less than 10 minutes, or less than 5 minutes.

[0218] The method according to the invention also comprises the polymerization of the reaction mixture, the polymerization being carried out, at least in part, at a temperature Tp greater than or equal to 50°C. A sufficiently high polymerization temperature allows rapid kinetics of the polymerization reaction. According to certain embodiments, the temperature Tp is greater than or equal to 55°C, or greater than or equal to 60°C, or greater than or equal to 65°C, or greater than or equal to 70°C, or greater than or equal to 75°C, or greater than or equal to 80°C, or greater than or equal to 85°C.

[0219] The temperature Tp is generally less than or equal to 120°C in order to minimize parasitic reactions competing with the polymerization reaction. Preferably, the temperature Tp is less than or equal to 100°C. The temperature Tp may in particular be less than or equal to 95°C.

[0220] Advantageously, the temperature Tp can be chosen in a range from 50°C to 65°C, or from 65°C to 70°C, or from 70°C to 75°C, or from 75°C to 80°C, or from 80°C to 85°C, or from 85°C to 90°C, or from 90°C to 95°C, or from 95°C to 100°C, or from 100°C to 120°C.

[0221] The reaction mixture is maintained, preferably with stirring, for a certain time, at the temperature Tp until the desired degree of polymerization is obtained. The duration of maintaining the reaction mixture at the temperature Tp is all the shorter as Tp is high. This duration is generally from 1 minute to 300 minutes, preferably from 5 minutes to 180 minutes, and extremely preferably from 10 minutes to 100 minutes.

[0222] Once the reaction has been completed to the desired degree of polymerization, the starting mixture is referred to as a product mixture.

[0223] The invention is characterized by the fact that the process comprises a progressive step of heating the reaction mixture until an acceleration of the polymerization reaction, the progressive heating step being carried out at an average heating rate chosen in a range from 0.65°C / minute to 2.5°C / minute.

[0224] The progressive heating step is preferably implemented at a speed average heating rate ranging from 0.70°C / minute to 2.2°C / minute, preferably at an average heating rate ranging from 0.75°C / minute to 2.0°C / minute, and more preferably at an average heating rate ranging from 0.8°C / min to 1.8°C / min.

[0225] The progressive heating step is implemented between an initial temperature T; and a final temperature Tf, the temperatures T; and Tf being such that: To < T; < Tf < Tp.

[0226] According to certain embodiments, To< T;< To+3O°C, or To< T;< To+2O°C, or To< Ti< T0+15°C.

[0227] According to some embodiments, Tp-45< Tf< Tp, or Tp-35< Tf< Tp, or Tp-25< Tf< Tp or Tp-15< Tf< Tp, or Tp-10< Tf< Tp.

[0228] According to certain embodiments, TrT; > 25°C, TrT;> 30°C, or TrT; > 35°C, or Tf-Ti > 40°C.

[0229] According to particular embodiments, the progressive heating step can be implemented between To and Tp.

[0230] The acceleration of the polymerization reaction is characteristic of the process according to the invention. It takes place around a temperature T*, which itself depends, at least in part, on the implementation of the progressive heating step itself.

[0231] The temperature T* can be evaluated by the fact that the acceleration of the polymerization is marked by a sudden increase in the production of hydrogen chloride.

[0232] Alternatively, the temperature T* can be evaluated by the fact that the acceleration of the polymerization is marked by a sudden increase in the heat flux emitted by the reaction mixture.

[0233] To illustrate this last point, [Fig. 1] represents the temperature of the double jacket (dotted line) for a double jacket reactor, such as that used for the implementation of the examples, as well as the temperature of the reaction mixture within the reactor (solid curve), as a function of time.

[0234] A temperature ramp is imposed as a setpoint so as to obtain a temperature ramp within the reactor ranging from a temperature Ti to a temperature Tf.

[0235] The temperature T* corresponds to the temperature at which the temperature of the reaction mixture increases more rapidly than the temperature imposed by the reactor temperature control means, forcing the reactor to temporarily cool the reaction mixture.

[0236] A consequence of the acceleration of the polymerization is the very rapid increase in the viscosity of the reaction mixture shortly after reaching the temperature T*.

[0237] It is estimated that the temperature T* generally observable for the processes according to the invention is between 20°C and 80°C. The temperature T* may in particular be from 20°C to 25°C, or from 25°C to 35°C, or from 35°C to 45°C or from 45°C to 55°C, or from 55°C to 65°C, or from 65°C to 75°C, or from 75°C to 80°C.

[0238] According to certain embodiments, T; < T*-10°C, preferably Ti < T*-20°C, and extremely preferably T; < T*-25°C.

[0239] According to certain embodiments, T*+5°C < Tp, preferably T*+10°C < Tp, and extremely preferably T*+15°C < Tp.

[0240] According to certain embodiments, the progressive heating step can be implemented by means of a succession of temperature stages, the temperature difference between each stage not exceeding 15°C, and preferably not exceeding 10°C, and very preferably not exceeding 5°C. Successive stages can be obtained by successive addition of a small fraction of preheated reaction solvent.

[0241] According to certain embodiments, the progressive heating step is implemented with one or more temperature ramps at a heating rate ranging from 0.65°C / minute to 2.5°C / minute, preferably with a heating rate ranging from 0.70°C / minute to 2.2°C / minute, preferably with a heating rate ranging from 0.75°C / minute to 2.0°C / minute, and more preferably with a heating rate ranging from 0.8°C / min to 1.8°C / min.

[0242] Such temperature ramps can be obtained by means of heating means integrated into the reactor, by the addition of a fraction of the preheated reaction solvent, or a combination of these two means.

[0243] According to certain embodiments, the reaction solvent may be preheated to a temperature which may be higher than the temperature Tp and be added to the reaction mixture, continuously or not.

[0244] According to certain embodiments, the progressive heating step is implemented with a single temperature ramp at a heating rate ranging from 0.65°C / minute to 2.5°C / minute, preferably with a heating rate ranging from 0.70°C / minute to 2.2°C / minute, preferably with a heating rate ranging from 0.75°C / minute to 2.0°C / minute, and more preferably with a heating rate ranging from 0.8°C / min to 1.8°C / min, between T; and Tf.

[0245] According to particular embodiments, the progressive heating step can be implemented with a single temperature ramp between -5°C and 120°C, or between -5°C and 100°C, or between -5°C and 95°C, or between -5°C and 90°C, or between -5°C and 85°C, or between -5°C and 80°C, or between -5°C and 75°C, or between -5°C and 70°C, or between -5°C and 65°C, or between -5°C and 60°C, or between -5°C and 55°C, or between -5°C and 50°C, or between 5°C and 120°C, or between 5°C and 100°C, or between 5°C and 95°C, or between 5°C and 90°C, or between 5°C and 85°C, or between 5°C and 80°C, or between 5°C and 75°C, or between 5°C and 70°C, or between 5°C and 65°C, or between 5°C and 60°C, or between 5°C and 55°C, or between 5°C and 50°C, or between 15°C and 120°C, or between 15°C and 100°C, or between 15°C and 95°C, or between 15°C and 90°C, or between 15°C and 85°C, or between 15°C and 80°C, or between 15°C and 75°C, or between 15°C and 70°C, or between 15°C and 65°C, or between 15°C and 60°C, or between 15°C and 55°C, or between 15°C and 50°C, or between 25°C and 120°C, or between 25°C and 100°C, or between 25°C and 95°C, or between 25°C and 90°C, or between 25°C and 85°C, or between 25°C and 80°C, or between 25°C and 75°C, or between 25°C and 70°C, or between 25°C and 65°C, or between 25°C and 60°C, or between 25°C and 55°C, or between 25°C and 50°C.

[0246] According to certain embodiments, the progressive heating step can be implemented by a combination of temperature steps, and temperature ramps by the aforementioned means.

[0247] In embodiments where a chain limiting agent is used, it may be introduced before or during the polymerization.

[0248] It can be introduced in full at once, or in parts.

[0249] Advantageously, the chain-limiting agent is introduced in its entirety before reaching temperature T*. Preferably again, the chain-limiting agent is introduced in its entirety before implementing the progressive heating step.

[0250] According to certain embodiments, the chain limiting agent can be introduced in its entirety during the contacting of the reactants.

[0251] In particular, in the two embodiments of bringing the reagents into contact described in detail above, the chain-limiting agent can advantageously be introduced before the introduction of the last reagent.

[0252] According to advantageous embodiments, the hydrogen chloride produced during the polymerization reaction is extracted from the reactor during the polymerization so as to promote the polymerization reaction. For this purpose, 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 nevertheless not preferred since it creates additional turbulence in the reaction mixture and makes temperature control within the reactor more difficult to control.

[0253] The process can be operated in a reactor or a succession of several reactors.

[0254] According to certain embodiments, the contacting, the progressive step of heating and polymerization are carried out in a single reactor.

[0255] According to certain embodiments, the contacting is carried out in a first reactor and the progressive heating step as well as the polymerization are carried out in a second reactor.

[0256] Reactors usable for implementing the present invention may for example example being glass reactors, enamelled reactors or reactors with corrosion-resistant metallurgy.

[0257] The reactors preferably have temperature control means and temperature measurement means inside them. The reactors may in particular comprise one or more temperature sensors inside them and be configured to cool and / or heat the reaction medium.

[0258] The reactors that can be used to implement the present invention are preferably provided with a stirring device such as a mechanical stirrer (which may, for example, comprise one or more stirring rotors) or a recirculation loop with a pump. The reaction mixture is preferably stirred during the contacting of the reactants, the progressive heating step and the polymerization to allow good homogenization of the chemical compounds as well as homogeneous heat transfer within the reaction mixture.

[0259] The reactor that can be used to implement the progressive heating step and the polymerization advantageously comprises a double-flow stirring system making it possible to keep the reaction mixture moving, in particular at the side walls of the reactor, as well as a tank bottom turbine making it possible to keep the reaction mixture moving, in particular at the end wall of the tank, and thus avoiding accelerated fouling of the reactor.

[0260] After the polymerization reaction has been completed to the desired degree of polymerization, the process of the invention may comprise a purification of the polyetherketone-neketone from the product mixture, in a manner known per se. This has for example already been described in document EP3655458.

[0261] This purification makes it possible in particular to separate the solvent, the catalyst, the unreacted reagents, as well as any reaction by-products from the polymer as such.

[0262] In particular, the purification generally comprises a step of bringing the mixture of products into contact with a protic solvent, so as to recover a first phase comprising the Lewis acid and a second phase comprising the polyetherketone-neketone.

[0263] The protic solvent may be an aqueous solution. The aqueous solution may simply be water. Alternatively, the aqueous solution may be an acidic solution, such as a hydrochloric acid solution. Preferably, the pH of the aqueous solution is not greater than 3, or not greater than 2. The dissociation of the polyether ketone Lewis acid complex is more efficient when an acidic solution is used.

[0264] Mixtures of solvents, 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.

[0265] Bringing the product mixture into contact with the protic solvent makes it possible to obtain a first phase (containing the protic solvent) and a second phase (containing the reaction solvent). The Lewis acid is mainly present in dissolved form in the first phase while the polyetherketoneketone is mainly present in precipitated form in the second phase.

[0266] The polyetherketoneketone can then be recovered by solid / liquid separation of the second phase. Advantageously, the solid / liquid separation is carried out by centrifugal filtration.

[0267] The dry solids content of raw polyetherketoneketone product at the end of the solid / liquid separation step is preferably between 10% by weight and 90% by weight, more preferably between 20% and 80% by weight and more preferably between 30% and 60% by weight.

[0268] The liquid effluents, containing the first phase and the second phase, may optionally be separated so as to be recovered separately, preferably by decantation, for possible reuse. A surfactant may be added to facilitate phase separation. When the Lewis acid is aluminum trichloride, the first phase advantageously contains it in proportions adapted so that it can be directly recycled by use in a water treatment / sludge flocculation process.

[0269] According to preferred embodiments, the crude polyetherketoneketone product from the preceding solid / liquid separation step can be further purified by washing with one or more protic solvents.

[0270] The protic solvent at this stage is preferably water or an aqueous solution. However, in other variants, the protic solvent at this stage may also be an organic solvent, optionally mixed with water. Linear or branched aliphatic alcohols such as methanol, ethanol and isopropanol are particularly preferred organic solvents. These organic solvents may optionally be mixed with each other and / or with water.

[0271] After the washing step or concomitantly with the washing step, another solid / liquid separation step can be carried out.

[0272] According to an advantageous embodiment, a centrifugal filtration device is used, so that washing and solid / liquid separation can be carried out concomitantly in the device, without resuspension of the product.

[0273] After the last solid / liquid separation, the recovered solid is advantageously dried.

[0274] The drying step can be carried out in a conventional manner, for example at a temperature ranging from 100°C to 280°C, and under atmospheric pressure or, preferably, under reduced pressure, for example at a pressure of 30 mbar.

[0275] The polymer 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 applied to PEKK, of 0.4 to 2.0 dL / g, and preferably of 0.7 to 1.5 dL / g.

[0276] In some embodiments, the polyetherketoneketone has an inherent viscosity of 0.4 to 0.5 dL / g, or 0.5 to 0.6 dL / g, or 0.6 to 0.7 dL / g, or 0.7 to 0.8 dL / g, or 0.8 to 0.9 dL / g, or 0.9 to 1.0 dL / g, or 1.0 dL / g to 1.1 dL / g, or 1.1 to 1.2 dL / g, or 1.2 to 1.3 dL / g, or 1.3 to 1.4 dL / g, or 1.4 to 1.5 dL / g.

[0277] According to particular embodiments, the polyetherketoneketone has an inherent viscosity of 0.98 dL / g to 1.4 dL / g.

[0278] In embodiments where a chain limiting agent is used in the process for manufacturing the polyetherketoneketone, for example benzoyl chloride or p-fluorobenzoyl chloride, the polyetherketoneketone has, for a given viscosity, a high proportion at the end of chains resulting from the limiting agent, compared to the polymers of the prior art.

[0279] Polyetherketoneketone preferentially verifies the following inequality:

[0280] IV *FDC(LDC) > LIM;

[0281] in which: IV represents the inherent viscosity of the polyetherketoneketone as measured according to ISO 307-2009 and expressed in dL / g, FDC(LDC) represents the molar concentration of the group resulting from the chain limiter relative to the total weight of the polymer, expressed in micro equivalents of limiter per gram of polymer, and LIM is a limit value, equal to at least 40.

[0282] According to certain embodiments the value of LIM is equal to 40, or equal to 41, or equal to 42, or equal to 43, or equal to 44, or equal to 45, or equal to 46, or equal to 47, or equal to 48, or equal to 49, or equal to 50.

[0283] The polyetherketoneketone obtained according to the process of the invention is generally in the form of flakes of fairly uniform size. In particular, and advantageously, the polymer has few large flakes. This is particularly advantageous for carrying out purification in an easier manner. Indeed, the extraction of aluminum chloride and / or impurities resulting from the polymerization is simpler and more effective to carry out on particles of reduced size. In addition, drying can also be implemented more quickly.

[0284] According to certain embodiments, the polyetherketoneketone flakes form a powder for which the mass proportion of particles of size strictly greater than 630 micrometers is less than or equal to 25%, preferably less than or equal to 15%, more preferably less than or equal to 10%, more preferably still less than or equal to 5%, and most preferably less than or equal to 2%, relative to the total weight of powder, as obtained by sieving using a sieve with a mesh size equal to 630 micrometers.

[0285] According to certain embodiments, the polyetherketoneketone flakes form a coarse powder for which the mass proportion of particles of size strictly greater than 450 micrometers is less than or equal to 75%, preferably less than or equal to 50%, more preferably less than or equal to 25%, even more preferably less than or equal to 20%, and most preferably less than or equal to 16%, relative to the total weight of powder, as obtained by sieving using a sieve with a mesh size equal to 630 micrometers. Examples

[0286] Example 1 A double-jacketed reactor (R2) equipped with stirring comprising “2 superimposed double-flow mobiles” and an inerting system under a nitrogen flow in the sky was used.

[0287] Ortho-dichlorobenzene and l,4-bis(4-phenoxybenzoyl)benzene were first added with stirring to reactor R2 in a l,4-bis(4-phenoxybenzoyl)benzene / ortho-dichlorobenzene mass proportion equal to 0.041.

[0288] Dynamic vacuum distillation (90°C, 150 mbar) and nitrogen inerting were implemented in order to eliminate any trace of residual water in the reactor.

[0289] A mixture of terephthaloyl and isophthaloyl chlorides, in a molar proportion of terephthaloyl chloride to isophthaloyl chloride equal to 0.45, was then added with stirring to the reaction medium so as to be in a substantially equimolar quantity, but slightly lacking compared to 1,4-bis(4-phenoxybenzoyl)benzene. The molar proportion of 1,4-bis(4-phenoxybenzoyl)benzene compared to the mixture of terephthaloyl and isophthaloyl chlorides is equal to 1.03.

[0290] Benzoyl chloride was also added under stirring as a chain limiter in a molar proportion relative to 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.042.

[0291] The reaction medium in reactor R2 was then cooled to -5°C. Solid aluminum trichloride was added slowly, over approximately 45 minutes, to the reaction medium. actional under stirring to form a reaction mixture, the temperature of the reaction mixture being maintained at a temperature around -5°C throughout the addition step. The molar proportion of aluminum trichloride relative to 1,4-bis(4-phenoxybenzoyl)benzene is equal to 6.3.

[0292] Once all the aluminum trichloride had been added, the temperature in reactor R2 was gradually increased according to a temperature ramp of 0.8°C / min until a reaction mixture temperature of 90°C was reached. The reaction mixture was then maintained at a temperature of 90°C for a period of 30 minutes.

[0293] The product mixture was then cooled to a temperature of 50°C or less. It was purified by mixing with an aqueous hydrochloric acid solution having a pH < 3 and solid / liquid separation using a filter. The crude polymer was then washed three times by resuspension and then filtration, the washing solutions successively used being methanol, a hydrochloric acid solution and water.

[0294] The purified polymer was finally dried at 180°C for 48 hours under vacuum (30 mbar).

[0295] Example 2 Example 2 corresponds to an experiment under the same conditions as those of Example 1, except that the benzoyl chloride was added in a molar proportion relative to the 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.029 and that a temperature ramp of 1°C / min was implemented to bring the reaction mixture to the final polymerization temperature of 90°C.

[0296] Example 3 Example 3 corresponds to an experiment under the same conditions as those of Example 1, except that a temperature ramp of 1.5°C / min was implemented.

[0297] Example 4 Example 4 corresponds to an experiment under the same conditions as those of Example 2, except that a temperature ramp of 1.5°C / min was implemented.

[0298] Example 5 Example 5 corresponds to an experiment under the same conditions as those of Example 3, except that the mass proportion l,4-bis(4-phenoxybenzoyl)benzene / ortho-dichlorobenzene is equal to 0.056 and the benzoyl chloride was added in a molar proportion relative to l,4-bis(4-phenoxybenzoyl)benzene equal to 0.049.

[0299] Example 6 Example 6 corresponds to an experiment under conditions similar to those of Example 1, except that a temperature ramp at 0.75°C / min was implemented.

[0300] Further, the reaction solvent was added fractionally in two portions. The first fraction (approximately 66%) was introduced with l,4-bis(4-phenoxybenzoyl)benzene and the acid chlorides and was then cooled to -5°C, before proceeding with the introduction of aluminum trichloride. Once all the aluminum trichloride had been added, the second solvent fraction (approximately 33%) preheated to 125°C was added continuously while implementing the temperature ramp.

[0301] Comparative example 1 Comparative example 1 corresponds to an experiment under the same conditions as those of example 1 except that a temperature ramp at 0.6°C / min was implemented.

[0302] Comparative example 2 Comparative example 2 corresponds to an experiment under the same conditions as those of example 1 except that a temperature ramp at 3.0°C / min was implemented and the benzoyl chloride was added in a molar proportion relative to 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.049.

[0303] Comparative example 3 Comparative Example 3 corresponds to an experiment under the same conditions as those of Example 3 except that the reaction medium was cooled and maintained at a temperature of 7°C for the step of contacting with the aluminum trichloride.

[0304] Comparative Example 4 Two double-jacket reactors (RI) and (R2) equipped with a stirring system and an inerting system under a nitrogen flow in the sky were used.

[0305] 1,4-Bis(4-phenoxybenzoyl)benzene, ortho-dichlorobenzene, terephthaloyl and isophthaloyl chlorides, aluminum trichloride and benzoyl chloride were introduced into the reaction medium in the same proportion as in Example 2 but according to a method corresponding to the methods of the prior art consisting of dispersing a cold premix in preheated reaction solvent.

[0306] A fraction S = 0.31 of ortho-dichlorobenzene (molar fraction of ortho-dichlorobenzene expressed relative to the total amount of ortho-dichlorobenzene used for the polymerization reaction) and 1,4-bis(4-phenoxybenzoyl)benzene were first added with stirring to the RL reactor

[0307] Dynamic vacuum distillation and nitrogen inerting were implemented in order to eliminate any trace of residual water in the reaction medium.

[0308] The mixture of terephthaloyl and isophthaloyl chlorides and the benzoyl chloride were then added with stirring.

[0309] The reaction medium in the RI reactor was then cooled to -5°C. Aluminum trichloride was added to the reaction medium with stirring, to form the reaction mixture, the temperature of the reaction mixture being maintained at a temperature around -5°C throughout the addition step.

[0310] Once all the aluminum trichloride had been added, the contents of reactor RI were transferred to reactor R2 with stirring, comprising a fraction 1-S = 0.69 of ortho-dichlorobenzene brought to and maintained at a temperature of 85°C. The reaction mixture was then maintained at this temperature for one hour.

[0311] The same process of purification of the product mixture as in Example 1 was then carried out.

[0312] Comparative example 5 Comparative Example 5 corresponds to an experiment under the same conditions as those of Comparative Example 4, except that the benzoyl chloride was added in a molar proportion relative to 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.035. Results

[0313] The efficiency of each process was calculated according to the following formula:

[0314] R (%) = 100 ^polymer / [0.996 mEKKE + 0.651 (mTa+ mæi) +0.748 mBza];

[0315] in which:

[0316] rnpoiymère is the mass of polymer recovered at the end of the process;

[0317] mEKKE, mTa, m1CE and mBzci are the masses respectively of l,4-bis(4-phenoxybenzoyl)benzene, terephthaloyl chloride, isophthaloyl chloride and benzoyl chloride introduced into the reaction mixture.

[0318] In the various experiments above, the polymer was obtained in the form of porous scales. They were characterized by viscosity measurement, by evaluation of the quantity of benzoyl chain ends and by sieving analysis of their particle size distribution.

[0319] Their inherent viscosity (IV), expressed in dl / g, was 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 (capillary inner diameter of 1.03 mm), according to ISO 307-2009 applied to PEKK.

[0320] The molar concentration of benzoyl chain ends (FDCBZ), expressed in microequivalents of benzoyl chain end per gram of polymer, could be determined by NMR method. The analysis was carried out by proton NMR (Avance 400 III HD, Avance 400 NEO). The samples were solubilized at room temperature in dichloromethane-d2, with the addition of trifluoroacetic acid-d. All the lines observed between 8.8 ppm and 6.8 ppm correspond to the protons of the polyetherketoneketone units. At 7.58 ppm, a line attributable to the b protons of the benzoyl chain end is highlighted. From the integration of all the lines of the spectrum and the integration of the line at 7.58 ppm, it is possible to determine the content of benzoyl chain ends. benzoyl chain of the polymer.

[0321] The particle size distribution of the flakes, and in particular the proportion of flakes strictly larger than 450 micrometers (%>450pm) and the proportion of flakes strictly larger than 630 micrometers (%>630pm) was evaluated by sieving. More precisely, an AS200 digit CA® vibrating sieve marketed by the company Retsch was used with a 200 mm diameter sieve and meshes adapted to the measured sizes (450 pm to measure the proportion of flakes strictly larger than 450 micrometers and 630 pm to measure the proportion of flakes strictly larger than 630 micrometers). The product to be sieved was placed on the upper sieve (approximately 60g) and the machine was set to have an amplitude of 2mm in intermittent mode activated (10s).

[0322] The sieving time was determined as follows: sieving is activated for a period of 5 minutes at the end of which the sieve and the receptacle receiving the particles passing through the sieve are weighed. The assembly is placed back on the sieve for a period of 5 minutes. If the mass of the sieve does not change, sieving is then finished. Otherwise, sieving is repeated until the weighed masses are stable.

[0323] All the results are grouped in the table below:

[0324] [Tables 1] # exp. Temp ramp. (°C / min) Molar ratio BzCl / E KKE Other remarkable condition R (%) IV (dl / g) FDCbz (peq / g ) IV* FDCbz %>450 pm % > 630pm Ex 1 0.8 0.042 76 0.99 51 50.5 12% 0% Ex 2 1 0.029 82 1.09 38 41.4 ND ND Ex 3 1.5 0.042 80 1.03 52 53.6 16% 0% Ex 4 1.5 0.029 85 1.13 40 45.2 ND ND Ex 5 1.5 0.049 Reaction mixture 1 more concentrated in the reaction solvent 85 0.84 59 49.6 5% 1% Ex 6 0.75 0.042 Partial introduction of the solvent during contacting of the reagents 75 0.93 54 50.2 ND ND Comp. 1 0.6 0.042 60 0.95 ND ND 23% 0% Comp. 2 3 0.049 9 0.9 ND ND ND ND Comp. 3 1.5 0.042 Contacting with A1C1 3 to 7°C 42 0.96 ND ND ND ND Comp. 4 - 0.029 Cold premix 74 0.93 37 34.4 ND >60% introduced into hot solvent Comp. 5 0.035 Cold premix introduced into hot solvent 71 0.92 40 36.8 94% >60%

[0325] “ND” means that the measurement was not carried out.

[0326] Comparison of Examples 1 to 5 with Comparative Examples 4 and 5 shows that the process according to the invention makes it possible to obtain a polyetherketoneketone with a better yield, in comparison with the process of the prior art consisting of preparing a premix cold and dispersing it in preheated solvent. The process makes it possible in particular to obtain a polymer having a high viscosity and at the same time integrating a high quantity of chain-limiting agent as a chemical end-of-chain function. The process also makes it possible to obtain smaller scales.

[0327] Comparison of Examples 1 to 5 with Comparative Examples 1 and 2 shows the necessary selection regarding the average heating rate for the progressive heating step. Indeed, poor yields are obtained if the average heating rate is too slow or too fast during the progressive heating step. These poor yields are even lower than those obtained by the prior art method of preparing a reaction premixture cold and dispersing it in preheated solvent (see Comparative Examples 4 and 5).

[0328] Comparison of Examples 1 and 3 with Comparative Example 3 shows that in the case where the contact time of the reactants is sufficiently long, the 1,4-bis(4-phenoxybenzoylbenzene) being furthermore introduced into the entire reaction solvent, a sufficiently low contact temperature is necessary so as to allow the 1,4-bis(4-phenoxybenzoylbenzene) to remain in suspension in the reaction mixture for a sufficiently long time, so as to allow an acceleration of the late polymerization reaction, and ultimately an increase in the yield of the process.

[0329] Comparison of Example 5 with Example 3 shows that the process according to the invention can be carried out at a higher concentration of the chemical compounds in the reaction solvent.

[0330] Comparison of Example 4 with Comparative Example 4 shows that for a molar concentration at the end of the benzoyl chain added to the reaction mixture, the process according to the invention makes it possible to obtain a polymer having a higher viscosity, the process of the prior art consisting of preparing a reaction premixture cold and dispersing it in preheated solvent. Furthermore, the comparison shows that for a molar concentration at the end of the benzoyl chain added to the reaction mixture, the process according to the invention makes it possible to obtain a polymer having a higher proportion at the end of the chain resulting from the chain limiting agent.

[0331] Comparison of Example 6 with Example 1 shows that the reaction solvent can be introduced in full when the reactants are brought into contact, or on the contrary in a fractional manner, a part of the reaction solvent being able to advantageously be used to implement the progressive heating step.

Claims

Claims

1. A method of manufacturing a polyetherketoneketone comprising: - bringing into contact an aromatic ether or a mixture of aromatic ethers, comprising at least 50% by mole of 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene or a mixture thereof, relative to the total number of moles of aromatic ether(s), with an acyl chloride or a mixture of acyl chlorides, and a Lewis acid, in all or part of a reaction solvent, so as to form a reaction mixture, the l,3-bis(4-phenoxybenzoyl)benzene and / or the l,4-bis(4-phenoxybenzoyl)benzene being essentially not solubilized in the reaction solvent at the end of the contacting step; and, - the polymerization of the reaction mixture, the polymerization being carried out, at least in part, at a temperature Tp greater than or equal to 50°C; the method being characterized in that it comprises a progressive step of heating the reaction mixture until an acceleration of the polymerization reaction is achieved, the progressive heating step being carried out at an average heating rate chosen in a range from 0.65°C / minute to 2.5°C / minute; one or more chain limiting agents being optionally added during the process.

2. The method of claim 1, wherein the acyl chloride(s) are selected from the group consisting of: terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, phosgene, adipoyl dichloride, tetrabromophthaloyl chloride, and compounds having the chemical formula: [Chem. 44] (V) [Chem.45] [Chem.49] [Chem. 50] û [Chem.51] in which: a is an integer ranging from 0 to 3; V is selected from: -O-, -S-, -(CF2)q-, -(CH2)q-, or -C((CH3)2)-; Z is selected from: -C(O)-, -SO2-, -C(O)-C6H4-C(O)-, -O-(CF2)qO-, -S-, -(CF2)q-, -(CH2)q-, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20.

3. A method according to any one of claims 1 and 2, wherein a mixture of aromatic ethers is used comprising in addition to an aromatic ether selected from the group consisting of: 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene, or a mixture thereof, at least one other aromatic ether selected from the group consisting of: diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone, the products of the Friedel-Crafts electrophilic substitution reaction of two molecules, in particular two same molecules, selected from: diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone with an acyl chloride molecule chosen from: phthaloyl chloride, phosgene, adipoyl dichloride, and compounds having the chemical formula: [Chem. 52] [Chem. 53] o [Chem. 54] [Chem.57] [Chem. 5 8] [Chem.59]

4.

5. in which: a is an integer ranging from 0 to 3; V is selected from: -O-, -S-, -(CF2)q-, -(CH2)q-, or -C((CH3)2)-; Z is selected from: -C(O)-, -SO2-, -C(O)-C6H4-C(O)-, -O-(CF2)qO-, -S-, -(CF2)q-, -(CH2)q-, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20; and, the products of the Friedel-Crafts electrophilic substitution reaction of two molecules, in particular two same molecules, chosen from: 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, and 3,4'-diphenoxybenzophenone with an acyl chloride molecule chosen from: terephthaloyl chloride and isophthaloyl chloride. Process according to any one of claims 1 to 3, in which the reaction solvent is chosen from the group consisting of: ortho-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, ortho-difluorobenzene, and mixtures thereof. A method according to any one of claims 1 to 4, wherein the Lewis acid is selected from the group consisting of: trichloride

6. aluminum, aluminum 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. A method according to any one of claims 1 to 5, wherein at least one chain-limiting agent is added during the method, the chain-limiting agent being a nucleophilic chain-limiting agent selected from compounds of the following chemical formula: [Chem. 60] in which: Xi represents a covalent bond, -O-, or -S-, and X2 represents, C6H5CO, or C6H5SO2; and, [Chem.61] (XIV) in which: X3 represents a halogen atom, an alkyl group, or an alkoxy group having 1 to 10 carbon atoms; or, the chain-limiting agent being an electrotrophic chain-limiting agent chosen from the compounds of the following formula: [Chem. 62] O [Chem.63] in which: X4 represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 10 carbon atoms, a nitro group, C6H5 CO or C6H5SO2.

7. Process according to any one of claims 1 to 6, in which the molar ratio of aromatic ether(s) to the reaction solvent(s) having been introduced in total into the reaction mixture at the end of the polymerization is: 0.005 to 0.030, preferably: 0.008 to 0.025, and extremely preferably: 0.010 to 0.

022.

8. A process according to any one of claims 1 to 7, wherein an excess of aromatic ether(s) is reacted with the acyl chloride(s), the molar ratio of aromatic ether(s) to acyl chloride(s) having been introduced in total into the reaction mixture at the end of the contacting step being preferably: 1.001 to 1.

1.

9. Process according to any one of claims 1 to 8, in which the molar ratio of Lewis acid(s) to aromatic ether(s) having been introduced in total into the reaction mixture at the end of the contacting step is: 5.0 to 7.0 and preferably: 5.5 to 6.

5.

10. Process according to any one of claims 1 to 9, in which the reaction mixture is maintained during the contacting step at a temperature To less than or equal to 5°C, preferably less than or equal to 0°C, and more preferably less than or equal to -5°C.

11. Method according to any one of claims 1 to 10, in which the temperature Tp is less than or equal to 120°C; and preferably less than or equal to 100°C.

12. Process according to any one of claims 1 to 11, in which the progressive heating step and the polymerization are carried out with stirring, preferably using stirring means comprising at least one double-flow rotor.

13. A method according to any one of claims 1 to 12, wherein a mixture of aromatic ethers is used, the mixture of aromatic ethers consisting of an aromatic ether selected from: 1,4-bis(4-phenoxybenzoyl)benzene, 1,3-bis(4-phenoxybenzoyl)benzene or a mixture of 1,4-bis(4-phenoxybenzoyl)benzene and 1,3-bis(4-phenoxybenzoyl)benzene; and, another aromatic ether selected from: diphenyl ether, 4,4'-diphenoxybenzophenone, or a mixture of diphenyl ether and 4,4'-diphenoxybenzophenone; the mixture of aromatic ethers comprising up to 20 mol%, preferably up to 10 mol%, and more preferably up to 5 mol% of said other aromatic ether, relative to the total number of moles of aromatic ethers.

14. A process according to any one of claims 1 to 12, wherein the aromatic ether, or where appropriate the mixture of aromatic ethers, consists of, or consists essentially of, 1,4-bis(4-phenoxybenzoyl)benzene.

15. A method according to any one of claims 1 to 14, wherein the acyl chloride is selected from the group consisting of isophthaloyl chloride, terephthaloyl chloride, and mixtures thereof.

16. A method according to any one of claims 1 to 15, wherein the Lewis acid is aluminum trichloride.

17. A process according to any one of claims 1 to 16, wherein the reaction solvent is ortho-dichlorobenzene.

18. A method according to any one of claims 1 to 17, wherein a chain limiting agent is added during the method, the chain limiting agent being benzoyl chloride, p-fluorobenzoyl chloride, or a mixture thereof.

19. A method according to any one of claims 1 to 18, wherein the progressive heating step is carried out at an average heating rate ranging from 0.70°C / minute to 2.2°C / minute, preferably at an average heating rate ranging from 0.75°C / minute to 2.0°C / minute, and more preferably at an average heating rate ranging from 0.8°C / min to 1.8°C / min.

20. A method according to any one of claims 1 to 19, wherein a mass fraction of reaction solvent at least equal to 0.15 is introduced before the end of the contacting step, the mass fraction being calculated by dividing the weight of reaction solvent having been introduced at the end of the contacting step relative to the total weight of reaction solvent having been introduced at the end of the polymerization.

21. Polyetherketoneketone having chain ends controlled by a chain limiter, verifying the following inequality: IV *FDC(LDC) > LIM; (eq.l)

22. in which: IV represents the inherent viscosity of the polymer, expressed in dl / g, as measured according to ISO 307-2009 applied to PEKK; FDC(LDC) represents the molar concentration of the group resulting from the chain limiter relative to the total weight of the polymer, expressed in micro equivalents of chain limiter per gram of polymer; LIM is a number equal to at least 40; said polyetherketoneketone being manufactured according to a process not comprising the addition of a dispersing agent. Polyetherketoneketone according to claim 21, wherein the chain limiter is a nucleophilic chain limiting agent selected from compounds of the following chemical formula: [Chem.65] in which: Xi represents a covalent bond, -O-, or -S-, and X2 represents, C6H5CO, or C6H5SO2; and, [Chem. 66] (XIV) in which: X3 represents a halogen atom, an alkyl group or an alkoxy group having 1 to 10 carbon atoms; or, the chain limiter is an electrophilic chain limiting agent selected from the compounds of the following formula: [Chem. 67] C—Cl (XV) [Chem. 68] ° (XVI) in which: X4 represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 10 carbon atoms, a nitro group, C6H5 CO or C6H5SO2.

23. A polyetherketoneketone according to any one of claims 21 and 22, wherein the chain limiter is benzoyl chloride, p-fluorobenzoyl chloride, or a mixture thereof.

24. Polyetherketoneketone according to any one of claims 21 to 23, having an inherent 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 having an inherent viscosity less than or equal to 2 dl / g, and preferably less than or equal to 1.5 dL / g; the inherent viscosity being measured at a concentration of 0.0005 g / mL in a 96.00% sulfuric acid solution at 25°C using a suspended-level Ubbelohde type viscosimeter according to ISO 307-2009.

25. A polyetherketoneketone according to claim 24, having an inherent viscosity ranging from 0.98 dL / g to 1.4 dL / g.

26. Polyetherketoneketone powder according to any one of claims 21 to 25, for which the mass proportion of particles of size strictly greater than 630 micrometers is less than or equal to 25%, preferably less than or equal to 15%, more preferably less than or equal to 10%, more preferably still less than or equal to 5%, and most preferably less than or equal to 2%, as obtained by sieving using a sieve with a mesh size equal to 630 micrometers.

27. ​​Polyetherketoneketone powder according to any one of claims 21 to 26, for which the mass proportion of particles of size strictly greater than 450 micrometers is less than or equal to 75%, preferably less than or equal to 50%, more preferably preferably less than or equal to 25%, more preferably still less than or equal to 20%, and most preferably less than or equal to 16%, as obtained by sieving using a sieve with a mesh size equal to 450 micrometers.

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