Process for preparation of polyetherketoneketones

Abstract

The invention relates to a process for the manufacture of polyetherketoneketones, comprising:-reacting an aromatic ether or a mixture of aromatic ethers, which comprises at least 50 mol% of 1, 3-bis (4-phenoxybenzoyl) benzene, 1, 4-bis (4-phenoxybenzoyl) benzene, or a mixture thereof, and-reacting the aromatic ether or the mixture of aromatic ethers, which comprises at least 50 mol% of 1, 3-bis (4-phenoxybenzoyl) benzene, 1, 4-bis (4-phenoxybenzoyl) benzene, or a mixture thereof; in some embodiments, 1, 3-bis (4-phenoxybenzoyl) benzene and / or 1, 3-bis (4-phenoxybenzoyl) benzene are contacted with acyl chloride or a mixture of acyl chloride and a Lewis acid in all or a portion of a reaction solvent, with respect to the total moles of aromatic ether (s), to form a reaction mixture, 1, 3-bis (4-phenoxybenzoyl) benzene and / or 1, 3-bis (4-phenoxybenzoyl) benzene and / or 1, 3-bis (4-phenoxybenzoyl) benzene. The 1, 4-bis (4-phenoxybenzoyl) benzene is substantially insoluble in the reaction solvent at the end of the contacting step; and-polymerizing the reaction mixture, the polymerization being carried out at least partially at a temperature Tp greater than or equal to 50 DEG C; said method is characterized in that it comprises a step-by-step heating of the reaction mixture until an acceleration of the polymerization reaction is achieved, the step-by-step heating step being carried out at an average heating rate selected from the range from 0.65 DEG C / min to 2.5 DEG C / min; one or more chain terminators are optionally added during the process.

Description

Technical Field

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

[0002] More particularly, the present invention relates to a process for making polyetherketoneketones by electrophilic precipitation polymerization.

[0003] The invention also relates to polymers obtainable via this process. Background Art

[0004] The following process is known, inter alia from US Pat. No. 3,791,890: the electrophilic preparation of polyetheretherketones from a mixture of isophthaloyl chloride and terephthaloyl chloride (acid chlorides) with diphenyl ether (aromatic ether) in the presence of aluminum chloride (Lewis acid) and using o-dichlorobenzene as reaction solvent.

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

[0006] This sequence of first preparing a cold premix and then dispersing the premix in the preheated reaction solvent allows the reaction mixture to be heated up to temperature extremely quickly. Although the mechanism occurring in the reaction medium is not fully understood, US 3 791 890 indicates that it enables the polymer particles formed to separate, facilitating the polymerization reaction and preventing the particles from coagulating into a gel-like mass characteristic of such polymerization reactions.

[0007] It is also known, in particular from Example 3 of US Pat. No. 4,816,556, that the sequence of preparing a cold premix and subsequently dispersing it in a preheated reaction solvent can also be carried out in an alternative electrophilic process for producing polyetheretherketones, in which 1,4-bis(4-phenoxybenzoyl)benzene (aromatic ether) is reacted with an acid chloride in the presence of aluminum chloride using o-dichlorobenzene as reaction solvent.

[0008] Furthermore, Example 3 of US Pat. No. 4,816,556 involves the use of benzoyl chloride to control the molecular weight of the polymer obtained.

[0009] In practice, the processes of the above two patent documents have not proven to be completely effective and only partially prevent the deposition of gel-like substances on the reactor walls and stirring systems during polymerization, implying several disadvantages.

[0010] Firstly, it reduces the productivity of the process, since such gels are difficult to recover. Secondly, it makes the control of the polymerization reaction more complicated, since it can lead to deviations in the stoichiometry of the reactants. Thirdly, fouling of the walls reduces the efficiency of the heat transfer between the temperature control means of the reactor and the reaction medium, making temperature control within the reactor more complicated. Fourthly, it necessitates the often laborious task of cleaning the reactor, which reduces the productivity of the facility, while generating liquid and solid effluents to be recycled and / or destroyed.

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

[0012] Furthermore, as demonstrated in the experimental part of the present patent application, the polymers obtained via the processes according to the two above patent documents are in the form of large particles of rather heterogeneous size, which in particular make the purification step more complicated.

[0013] Finally, as demonstrated in the experimental part of the present patent application, the process according to the two above patent documents does not allow good incorporation of the chain limiter into the ends of the polymer chains for a given polymer viscosity.

[0014] It is also known practice, in particular from WO 9 523 821, that the addition of polymeric dispersants can avoid coagulation of viscous polymer products.

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

[0016] Among the dispersants, the patent indicates, for example, compounds having as side groups a fragment having the following formula:

[0017]

[0018] The practice is also known, in particular from US 2012 / 0263953, of using control agents and in particular benzoic acid and its derivatives as dispersants.

[0019] However, adding dispersants has a number of disadvantages. The use of certain dispersants, especially those with fragments of formula (0) as described above, leads to excessive consumption of Lewis acids in the process, which also form complexes with the dispersant. In addition, this complicates the management of process effluents, especially the development / recycling of effluents containing Lewis acids. Finally, dispersants cannot be completely removed from the polymer being manufactured and can have a deleterious effect on the thermal stability of the polymer.

[0020] Finally, still with the goal of avoiding condensation and reactor fouling, EP 3 712 193 proposes a process in which an inert gas, especially nitrogen, is blown into the reaction medium during the polymerization reaction. This is in some cases detrimental to the fine temperature control in the reaction medium and therefore to the good reproducibility of the process.

[0021] Therefore, there is currently a need to improve the process for manufacturing polyetherketoneketones to further limit the fouling caused by coagulation of oligomer-Lewis acid complexes according to current knowledge. There is also a need to provide a simpler and / or well reproducible and / or better yield and / or more efficient manufacturing process.

[0022] The present invention proposes a process which preferably overcomes one or more disadvantages of processes according to the prior art, and also proposes polymers obtainable via the process.

[0023] Purpose of the Invention

[0024] One object of the present invention, at least according to certain embodiments, is to propose a process that is easy to carry out and that effectively limits fouling of a polymerization reactor.

[0025] It is another object of the present invention, at least according to certain embodiments, to increase the yield of a process for making polyetherketoneketone.

[0026] It is a further object of the present invention, at least according to certain embodiments, to increase the efficiency of the process for producing polyetherketoneketone, in particular to enable less frequent cleaning of the reactor.

[0027] Another object of the present invention is to propose a process that allows optimal control of the reaction parameters, in particular the temperature in the reactor, at least according to certain embodiments.

[0028] Another object of the present invention is to propose a process that enables optimal control of the degree of polymerization, at least according to certain embodiments, measured indirectly but in a general way by evaluating the viscosity of the polymer produced.

[0029] Another object of the present invention, at least according to certain embodiments, is to propose a process that enables optimal control of the chain end chemistry of the polymers produced.

[0030] It is another object of the present invention, at least according to certain embodiments, to obtain polymer particles of more uniform size and / or smaller size. Summary of the invention

[0031] The present invention relates to a process for producing polyetherketoneketone, which involves:

[0032] - contacting an aromatic ether or a mixture of aromatic ethers (comprising at least 50 mole % of 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene, or a mixture thereof, relative to the total moles of the aromatic ether(s)) with an acid chloride or a mixture of acid chlorides and a Lewis acid in all or a portion of a reaction solvent to form a reaction mixture. The 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene is substantially insoluble in the reaction solvent at the end of the contacting step; and,

[0033] - polymerizing the reaction mixture, the polymerization being carried out at least partially at a temperature Tp greater than or equal to 50°C.

[0034] The process is characterized in that it comprises a step of gradually heating the reaction mixture until an acceleration of the polymerization reaction is achieved,

[0035] The stepwise heating step is performed at an average heating rate selected from the range from 0.65° C. / min to 2.5° C. / min.

[0036] Among the chemicals introduced during the process, in particular during the contacting step and / or during the polymerisation and / or during the gradual heating step, one or more chain limiters may optionally be added.

[0037] According to certain embodiments, the acid chloride(s) are selected from the group consisting of terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, phosgene, adipoyl chloride, tetrabromophthaloyl chloride, and compounds having the following formula:

[0038]

[0039]

[0040] in:

[0041] a is an integer ranging from 0 to 3;

[0042] V is selected from: -O-, -S-, -(CF2) q -、-(CH2) q -, or -C((CH3)2)-;

[0043] Z is selected from: -C(O)-, -SO2-, -C(O)-C6H4-C(O)-, -O-(CF2) q -O-, -S-, -(CF2) q -、-(CH2) q -, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20.

[0044] According to certain embodiments, a mixture of aromatic ethers is used. The mixture, in addition to an aromatic ether selected from 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene, or a mixture thereof, further comprises at least one other aromatic ether selected from the following:

[0045] diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone,

[0046] The product of the reaction of two molecules, especially two identical molecules, selected from the group consisting of diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone by electrophilic Friedel-Crafts substitution with an acyl chloride molecule selected from the group consisting of phthaloyl chloride, phosgene, adipoyl chloride, and compounds of the following formula:

[0047]

[0048]

[0049] in:

[0050] a is an integer ranging from 0 to 3;

[0051] V is selected from: -O-, -S-, -(CF2) q -、-(CH2) q -, or -C((CH3)2)-;

[0052] Z is selected from: -C(O)-, -SO2-, -C(O)-C6H4-C(O)-, -O-(CF2) q -O-, -S-, -(CF2) q -、-(CH2) q -, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20;

[0053] and the product of an electrophilic Friedel-Crafts substitution reaction of two molecules, especially the same two molecules, selected from 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, and 3,4'-diphenoxybenzophenone, with an acyl chloride molecule selected from terephthaloyl chloride and isophthaloyl chloride.

[0054] According to certain embodiments, the reaction solvent is selected from the group consisting of o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene, and mixtures thereof.

[0055] According to certain 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, iron chloride, tin chloride, titanium tetrachloride and molybdenum pentachloride, and mixtures thereof.

[0056] According to certain embodiments, at least one chain limiter is added during the process.

[0057] The chain limiter may be a nucleophilic chain limiter. The agent is preferably selected from compounds having the following chemical formula:

[0058]

[0059] in:

[0060] X1 represents a covalent bond, -O-, or -S-; and

[0061] X2 represents C6H5CO or C6H5SO2; and

[0062]

[0063] in:

[0064] X3 represents a halogen atom, an alkyl group having from 1 to 10 carbon atoms or an alkoxy group.

[0065] Alternatively or additionally, the chain limiter may be an electrophilic chain limiter. The agent is preferably selected from compounds having the following formula:

[0066]

[0067] in:

[0068] X4 represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO group or a C6H5SO2 group;

[0069] Or a compound of the formula:

[0070]

[0071] in:

[0072] Xn represents n groups, n is an integer selected from between 2 and 5, each group being independently selected from: a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO or a C6H5SO2 group.

[0073] According to certain embodiments, the molar ratio of the aromatic ether(s) introduced in total into the reaction mixture at the end of the polymerization relative to the reaction solvent(s) is: from 0.005 to 0.030, preferentially: from 0.008 to 0.025 and very preferably: from 0.010 to 0.022.

[0074] According to certain embodiments, an excess of (one or more) aromatic ethers is reacted with (one or more) acyl chlorides. Advantageously, the molar ratio of (one or more) aromatic ethers introduced into the reaction mixture at the end of the contacting step relative to (one or more) acyl chlorides is preferentially from 1.001 to 1.1.

[0075] According to certain embodiments, the molar ratio of the Lewis acid(s) introduced in total to the reaction mixture at the end of the contacting step relative to the aromatic ether(s) is from 5.0 to 7.0, preferably from 5.5 to 6.5.

[0076] According to certain embodiments, the reaction mixture is maintained at a temperature TO less than or equal to 5°C, preferentially less than or equal to 0°C, and more preferably less than or equal to -5°C during the contacting step.

[0077] According to certain embodiments, the temperature Tp is less than or equal to 120°C, and preferably less than or equal to 100°C.

[0078] According to certain embodiments, the gradual heating step and the polymerization are carried out under stirring, preferably using stirring means comprising at least one double-fluid rotor.

[0079] According to certain embodiments, the process is carried out using a mixture of aromatic ethers. The mixture of aromatic ethers is formed by: an aromatic ether selected from the group consisting of 1,4-bis(4-phenoxybenzoyl)benzene, 1,3-bis(4-phenoxybenzoyl)benzene, or a mixture thereof; and an additional aromatic ether selected from the group consisting of diphenyl ether, 4,4'-diphenoxybenzophenone, or a mixture thereof. The mixture of aromatic ethers contains up to 20 mol %, preferably up to 10 mol %, and more preferably up to 5 mol % of the additional aromatic ether, relative to the total moles of the aromatic ethers.

[0080] According to certain embodiments, the aromatic ether or, where appropriate, the mixture of aromatic ethers, respectively, consists of or consists essentially of 1,4-bis(4-phenoxybenzoyl)benzene.

[0081] According to certain embodiments, the acid chloride(s) are selected from isophthaloyl chloride, terephthaloyl chloride, and mixtures thereof.

[0082] According to certain embodiments, the Lewis acid is aluminum trichloride.

[0083] According to certain embodiments, the reaction solvent is o-dichlorobenzene.

[0084] According to certain embodiments, a chain limiter is added during the process. The chain limiter may be benzoyl chloride, p-fluorobenzoyl chloride, 3,5-difluorobenzoyl chloride, or a mixture thereof. The chain limiter may in particular be benzoyl chloride, p-fluorobenzoyl chloride, or a mixture thereof.

[0085] According to certain embodiments, the stepwise heating step is performed at an average heating rate ranging from 0.70°C / min to 2.2°C / min, preferentially at an average heating rate ranging from 0.75°C / min to 2.0°C / min, and more preferably at an average heating rate ranging from 0.8°C / min to 1.8°C / min.

[0086] 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, said mass fraction being calculated by dividing the weight of reaction solvent introduced at the end of the contacting step by the total weight of reaction solvent introduced at the end of the polymerization.

[0087] The present invention also relates to polyetherketoneketones having chain ends controlled by chain limiters, which satisfy the following inequality:

[0088] IV*FDC (LDC) ≥LIM; (Equation 1)

[0089] in:

[0090] IV represents the intrinsic viscosity of the polymer, expressed in dL / g, which is measured according to the standard ISO 307-2009 applicable to PEKK;

[0091] FDC (LDC) represents the molar concentration of groups derived from the chain limiter relative to the total weight of the polymer, expressed in microequivalents of chain limiter per gram of polymer;

[0092] LIM is a number that is at least 40.

[0093] The polymer is obtainable via an electrophilic process, in particular via the electrophilic process according to the invention.

[0094] According to certain embodiments, the chain limiter is a nucleophilic chain limiter selected from compounds having the following chemical formula:

[0095]

[0096] in:

[0097] X1 represents: a covalent bond, -O-, or -S-; and

[0098] X2 represents C6H5CO or C6H5SO2; and

[0099]

[0100] in:

[0101] X3 represents a halogen atom, an alkyl group containing from 1 to 10 carbon atoms, or an alkoxy group;

[0102] Or, the chain limiter is an electrophilic chain limiter selected from compounds having the following chemical formula:

[0103]

[0104] in:

[0105] X4 represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO group or a C6H5SO2 group;

[0106] and

[0107]

[0108] in:

[0109] Xn represents n groups, n is an integer selected from between 2 and 5, each group being independently selected from: a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO or a C6H5SO2 group.

[0110] According to certain embodiments, the chain limiter is benzoyl chloride, p-fluorobenzoyl chloride, 3,5-difluorobenzoyl chloride, or a mixture thereof.

[0111] According to certain embodiments, the chain limiter is benzoyl chloride, p-fluorobenzoyl chloride, or a mixture thereof.

[0112] According to certain embodiments, the polyetherketoneketone has an intrinsic viscosity greater than or equal to 0.4 dL / g, preferentially greater than or equal to 0.5 dL / g, preferentially greater than or equal to 0.6 dL / g, and more preferably greater than or equal to 0.7 dL / g, measured according to standard ISO 307-2009 using a viscometer such as an Ubbelohde suspension grade viscometer at 25°C in a 96.00% sulfuric acid solution at a concentration of 0.0005 g / mL.

[0113] Alternatively or additionally, the polyetherketoneketone has an intrinsic viscosity less than or equal to 2 dL / g, and preferably less than or equal to 1.5 dL / g.

[0114] According to certain embodiments, the polyetherketoneketone has an intrinsic viscosity ranging from 0.98 dL / g to 1.4 dL / g.

[0115] According to certain embodiments, the polyetherketoneketone does not contain any dispersant.

[0116] 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 having a size strictly greater than 630 microns is less than or equal to 25%, preferentially less than or equal to 15%, and more preferentially less than or equal to 10%, according to screening using a sieve with a mesh size equal to 630 microns.

[0117] 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 having a size strictly greater than 450 microns is less than or equal to 75%, preferentially less than or equal to 50%, more preferentially less than or equal to 25%, even more preferentially less than or equal to 20%, and most preferably less than or equal to 16%, according to screening using a sieve with a mesh size equal to 450 microns.

[0118] According to certain embodiments, the polyetherketoneketone powder has a mass fraction greater than or equal to 200 kg / m 3 The tapped density of , as measured in the examples.

[0119] According to certain embodiments, the polyetherketoneketone powder has a molecular weight of less than or equal to 4 μm. 2 / g BET specific surface area. DETAILED DESCRIPTION

[0120] The polyetherketoneketone, also referred to as PEKK, prepared according to the process of the present invention comprises at least 25 mol % of repeating units selected from the group consisting of:

[0121]

[0122] Also denoted as an isophthalic unit or by the initial letter "I";

[0123]

[0124] Also denoted as a terephthalic unit or by the initial letter "T"; and,

[0125] A mixture thereof.

[0126] The polyetherketoneketone produced according to the present invention may contain 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 repeating units of formula (I) and / or formula (II), relative to the total moles of repeating units of the polymer.

[0127] According to the embodiment in which the polyetherketoneketone comprises recurring units of formula (I) and formula (II), these units are regarded as a whole relative to the total number of moles of recurring units in the polymer.

[0128] According to certain embodiments, the polyetherketoneketone according to the invention consists essentially of repeating units of formula (I) and / or formula (II), i.e. contains at least 95 mol %, preferably at least 98 mol %, of repeating units of formula (I) and / or formula (II) (considered as a whole where appropriate), relative to the total number of moles of repeating units of the polymer.

[0129] According to certain embodiments, the polyetherketoneketone according to the invention consists essentially of or consists of repeating units of formula (I) and / or formula (II), the ratio of the units of formula (II) relative to the units of formula (I), expressed as the ratio T:I, being from 50:50 to 100:0. The ratio T:I may in particular 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. According to certain embodiments, the polyetherketoneketone consists of repeating units of formula (I) and formula (II), the ratio of the units of formula (II) relative to the units of formula (I), expressed as the ratio T:I, being from 55:45 to 95:5.

[0130] According to certain embodiments, the polyetherketoneketone according to the invention consists essentially of or consists of repeating units (I) and / or (II), wherein the ratio T:I is from 0:100 to 50:50. In particular, the ratio T:I 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.

[0131] The polymerization reaction involved is a polycondensation reaction involving an electrophilic substitution between one or more aromatic ethers and one or more acyl chlorides in the presence of a Lewis acid and optionally a chain limiter in a reaction solvent. The polymerization reaction is also precipitating, because the formed polymer precipitates from the reaction mixture. Finally, it is exothermic. Hydrogen chloride is produced during the polycondensation.

[0132] Without being bound by theory, the inventors believe that carrying out the process according to the invention, in particular contacting the reactants to form a reaction mixture in which 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene remain substantially suspended, followed by a stepwise heating step, allows a metastable state of the reaction mixture to be produced in which 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene are substantially suspended. Maintaining 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene (considered as a whole where appropriate) in an undissolved form in the reaction mixture for a sufficiently long time to enable acceleration of the polymerization reaction to occur at a higher temperature than under conditions in which thermodynamic equilibrium would be allowed to be established. Doing so allows the polymerization reaction to be initiated by rapid kinetics and thus limits the time during which the reaction mixture is substantially formed of low molecular weight polymer chains, which are particularly prone to coagulation and forming gels that foul the reactor walls and / or the stirring system. The process according to the invention thus allows limiting the formation of wall fouling gels without resorting to dispersants as described in the prior art, in particular in WO 9523 821 and in US 2012 / 0263953.

[0133] The term "substantially suspended" or "substantially insoluble" means that at a given time and temperature, 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene (considered as a whole where appropriate) has 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% dissolved in the reaction solvent, relative to the total weight of the substance in the reaction solvent.

[0134] The acid chloride is preferably selected from the group consisting of terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, phosgene, adipoyl chloride, and compounds of the formula:

[0135]

[0136]

[0137] in:

[0138] a is an integer ranging from 0 to 3;

[0139] V is selected from: -O-, -S-, -(CF2) q -、-(CH2) q -, or -C((CH3)2)-;

[0140] Z is selected from: -C(O)-, -SO2-, -C(O)-C6H4-C(O)-, -O-(CF2) q -O-, -S-, -(CF2) q -、-(CH2) q -, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20.

[0141] A number of measures may be taken to ensure that the acid chloride(s) used have a satisfactory degree of purity. In particular, acid chlorides are readily hydrolyzable species and may contain a certain amount of hydrolyzed species as impurities if they are not stored and / or handled under appropriate conditions.

[0142] In particular, the acyl chlorides must not come into contact with water and / or a humid atmosphere at any time before being placed in the reactor. It may therefore be advantageous to store the acyl chlorides in a sealed container away from ambient air, or alternatively in a container containing dry air. Advantageously, the acyl chlorides may be kept under a dry nitrogen atmosphere to avoid contact with ambient air before being placed in the reactor.

[0143] The hydrolyzed form of the acyl chloride is difficult to analyze and quantify. As a result, a practical and rapid method for ensuring the purity level of the acyl chloride is to dissolve it in a solvent, especially a reaction solvent such as o-dichlorobenzene, and then analyze the mixture for haze. In particular, high haze values ​​obtained by this test indicate a large amount of insoluble contaminants, mainly in the hydrolyzed form.

[0144] Thus, the acid chloride or acid chloride mixture used is preferably such that, after introducing it into the anhydrous reaction solvent at a reference concentration of 6.5% by weight, the mixture obtained has a haze of less than 500 NTU (nephelometric units) at a temperature of 20° C. for 10 minutes. The haze values ​​are provided with reference to a solvent sample not comprising any acid chloride.

[0145] According to certain embodiments, the acid chloride or acid chloride mixture used is preferably such that after introducing it into an anhydrous reaction solvent at a reference concentration of 6.5% by weight at a temperature of 20° C. for 10 minutes, the mixture obtained has a haze of less than 200 NTU, preferentially less than 100 NTU, very preferentially less than 50 NTU, and more preferably less than 20 NTU.

[0146] According to an embodiment in which the polyetherketoneketone consists essentially of repeating units of formula (I) and / or (II) or consists of repeating units of formula (I) and / or (II), the acid chloride or the acid chloride mixture consists essentially of terephthaloyl chloride, isophthaloyl chloride, or a mixture of terephthaloyl chloride and isophthaloyl chloride, or consists of terephthaloyl chloride, isophthaloyl chloride, or a mixture of terephthaloyl chloride and isophthaloyl chloride.

[0147] The aromatic ether is 1,3-bis(4-phenoxybenzoyl)benzene or 1,4-bis(4-phenoxybenzoyl)benzene or a mixture of aromatic ethers containing at least 50 mol % of an aromatic ether selected from the group consisting of:

[0148] 1,3-Bis(4-phenoxybenzoyl)benzene having the formula:

[0149]

[0150] 1,4-Bis(4-phenoxybenzoyl)benzene having the formula:

[0151]

[0152] or a mixture thereof; relative to the total moles of (one or more) aromatic ethers.

[0153] In the case where the mixture of aromatic ethers comprises a mixture of 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene, the mixture of aromatic ethers comprises at least 50 mol % of 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene considered as a whole, relative to the total moles of the aromatic ethers.

[0154] According to certain embodiments, the aromatic ether or the mixture of aromatic ethers comprises at least 60 mol %, or at least 70 mol %, or at least 80 mol %, or at least 90 mol %, or at least 95 mol % of 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene (considered as a whole where appropriate), relative to the total number of moles of the aromatic ether(s).

[0155] According to certain embodiments, a mixture of aromatic ethers is used, which, in addition to the ether selected from 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene, also comprises another aromatic ether selected from the group consisting of diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone, or an aromatic ether selected from the group consisting of two molecules, in particular the same two molecules, electrophilically reacting with an acyl chloride molecule. The product of the reaction of 1,2-diphenyl ether and 1,4-diphenyl ether, the two molecules are selected from: diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone, the acid chloride molecule is preferably selected from the list previously described (except for isophthaloyl chloride or terephthaloyl chloride in the case of diphenyl ether, since the reaction provides 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene, respectively).

[0156] According to certain embodiments, a mixture of aromatic ethers is used. It is formed from: 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene (considered as a whole where appropriate), and: diphenyl ether and / or 4,4'-diphenoxybenzophenone. The mixture may contain up to 20 mol %, preferentially up to 10 mol %, and more preferably up to 5 mol % of diphenyl ether and / or 4,4'-diphenoxybenzophenone (considered as a whole where appropriate), relative to the total number of moles of the aromatic ether.

[0157] The presence of diphenyl ether and / or 4,4'-diphenoxybenzophenone in addition to 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene allows the ratio of ether to ketone groups in the polymer to be increased compared to embodiments in which only 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene is used.

[0158] According to certain embodiments, a mixture of aromatic ethers is used. It is formed from: 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene, and: diphenyl ether. The mixture may contain up to 20 mol %, preferentially up to 10 mol %, more preferably up to 5 mol %, and very preferably up to 1 mol % of diphenyl ether, relative to the total moles of the aromatic ether.

[0159] According to certain embodiments, a mixture of aromatic ethers is used, which consists of 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene.

[0160] 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 contain up to 20 mol %, preferentially up to 10 mol %, more preferably up to 5 mol %, and very preferably up to 1 mol % of diphenyl ether, relative to the total moles of the aromatic ether.

[0161] According to certain embodiments, the aromatic ether is exclusively 1,4-bis(4-phenoxybenzoyl)benzene.

[0162] 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 contain up to 20 mol %, preferentially up to 10 mol %, more preferably up to 5 mol %, and very preferably up to 1 mol % of diphenyl ether, relative to the total moles of the aromatic ether.

[0163] According to certain embodiments, the aromatic ether is exclusively 1,3-bis(4-phenoxybenzoyl)benzene.

[0164] According to certain embodiments, the aromatic ether is only 1,4-bis(4-phenoxybenzoyl)benzene.Polyetherketoneketones having a ratio T:I from 50:50 to 100:0 can be obtained by mixing isophthaloyl chloride and terephthaloyl chloride and by adjusting the isophthaloyl chloride / terephthaloyl chloride ratio.

[0165] According to certain embodiments, the acid chloride is only terephthaloyl chloride. A polyetherketoneketone having a ratio T:I from 50:50 to 100:0 can be obtained by a mixture of 1,3-bis(4-phenoxybenzoyl)benzene and 1,4-bis(4-phenoxybenzoyl)benzene and by adjusting the ratio of 1,3-bis(4-phenoxybenzoyl)benzene to 1,4-bis(4-phenoxybenzoyl)benzene.

[0166] In a similar manner, according to certain embodiments, the aromatic ether is only 1,3-bis(4-phenoxybenzoyl)benzene (or, correspondingly, the acid chloride is only isophthaloyl chloride). A polyetherketoneketone having a ratio T:I from 0:100 to 50:50 can be obtained by adjusting the ratio of isophthaloyl chloride to terephthaloyl chloride (or, correspondingly, by adjusting the ratio of 1,3-bis(4-phenoxybenzoyl)benzene to 1,4-bis(4-phenoxybenzoyl)benzene).

[0167] 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, iron chloride, tin chloride, titanium tetrachloride and molybdenum pentachloride, and mixtures thereof.

[0168] Preferably, only one type of Lewis acid is used in the polymerization reaction.

[0169] Among the Lewis acids mentioned above, aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, iron trichloride, gallium trichloride, and molybdenum pentachloride are preferred.

[0170] Aluminum trichloride is particularly preferred.

[0171] Preferably, the Lewis acid is added in solid form. Alternatively, it can also be added in the form of a suspension or colloid, i.e. as a heterogeneous mixture of solid particles of the Lewis acid in a solvent, or in the form of a solution, i.e. as a homogeneous mixture in a solvent. The solvent used for the suspension / colloid or for the solution is advantageously a reaction solvent.

[0172] According to some variants, the Lewis acid is added in the form of particles, such as in the form of a powder (e.g. with a Dv80 of less than 1 mm and preferably a Dv50 of less than 0.5 mm). The parameters Dv80 and Dv50 are the particle sizes at the 80th and 50th percentiles (by volume) of the cumulative size distribution of the Lewis acid particles, respectively. These parameters can be determined, in particular, by screening.

[0173] The Lewis acid used in the process according to the invention preferably has such a degree of purity that when it is introduced into water at a concentration of 11% by weight with stirring at 20° C. and substantially dissolved, it contains less than 0.1% by weight of insoluble matter, and more preferentially less than 0.05% by weight of insoluble matter, as measured gravimetrically.

[0174] The reaction solvent may be selected from: o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene, and a mixture thereof.

[0175] Among the above-mentioned reaction solvents, o-dichlorobenzene, trichlorobenzene, 1,2,3-trichlorobenzene, and o-difluorobenzene are preferred, and o-dichlorobenzene is particularly preferred.

[0176] The reaction solvent preferably contains less than 500 wt ppm of water to limit the hydrolysis reaction of the acyl chloride or the mixture of acyl chlorides. Advantageously, the reaction solvent contains less than 250 wt ppm of water, preferably less than 150 wt ppm of water, more preferably less than 100 wt ppm of water, and even more preferably less than 50 wt ppm of water.

[0177] In a preferred variant, the aromatic ether or the mixture of aromatic ethers also preferably contains less than 500 ppm by weight of water to limit the hydrolysis reaction of the acid chloride or the mixture of acid chlorides. The same range of preferred values ​​as for the reaction solvent also applies to the aromatic ether or the mixture of aromatic ethers after making necessary modifications.

[0178] In a more preferred variant, the reaction solvent and the aromatic ether or the mixture of aromatic ethers contain less than 500 ppm by weight of water in total to limit the hydrolysis reaction of the acyl chloride or the mixture of acyl chlorides. Under the overall consideration, the same range of preferred values ​​as for the reaction solvent also applies to the reaction solvent and the aromatic ether or the mixture of aromatic ethers after making necessary modifications.

[0179] In order to ensure that there are no traces of water in the reactor, the process advantageously comprises a preliminary drying step, i.e. reducing the water content of the reaction solvent and / or the aromatic ether or the mixture of aromatic ethers before contacting them with the acyl chloride or the mixture of acyl chlorides. The means for carrying out this preliminary drying step include, for example, distillation of the chemical compound, or contacting it with molecular sieves, or contacting it with a dehydrating agent such as a small amount of aluminum chloride.

[0180] The use of one or more chain limiters in the reaction medium is optional. Its addition allows better control of the degree of polymerization and thus of the viscosity of the polymer to be produced. It also allows better control of the chain ends of the polymer and ensures, where appropriate, better stability, especially better thermal stability, of the polymer.

[0181] A further advantage of the process according to the invention compared to the processes of the prior art, in particular those involving the preparation of a cold premix and the dispersion of this premix in a preheated reaction solvent, is that, for a given viscosity, it makes it possible to obtain polymers having a higher proportion of polymer end chains originating from the chain limiter.

[0182] Two types of chain limiters can be used: nucleophilic chain limiters or electrophilic chain limiters.

[0183] According to certain embodiments, the chain limiter is a nucleophilic chain limiter. The nucleophilic chain limiter may be selected from compounds having the following chemical formula:

[0184]

[0185] in:

[0186] X1 represents: a covalent bond, -O-, or -S-; and

[0187] X2 represents C6H5CO or C6H5SO2;

[0188] or a compound of the following formula:

[0189]

[0190] in:

[0191] X3 is a halogen, an alkyl group containing from 1 to 10 carbon atoms or an alkoxy group.

[0192] Preferably, the nucleophilic chain limiter is selected from the group consisting of: 4-phenoxybenzophenone, 4-phenoxydiphenyl sulfone, anisole, fluorobenzene, chlorobenzene, biphenyl, toluene, and mixtures thereof.

[0193] A particularly advantageous nucleophilic chain-limiting agent is 4-phenoxybenzophenone.

[0194] According to certain embodiments, the chain limiter is an electrophilic chain limiter. The electrophilic chain limiter may be selected from compounds of the following formula:

[0195]

[0196] in:

[0197] X4 represents: a hydrogen atom, a halogen atom, an alkyl or alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO or C6H5SO2 group; or a compound of the following formula:

[0198]

[0199] in:

[0200] Xn represents n groups, n is an integer selected from between 2 and 5, each group being independently selected from: a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO or a C6H5SO2 group.

[0201] Preferably, the electrophilic chain-limiting agent is selected from the group consisting of benzoyl chloride, acetyl chloride, 3,5-dichlorobenzoyl chloride, 3,5-difluorobenzoyl chloride, p-fluorobenzoyl chloride, p-chlorobenzoyl chloride, p-methoxybenzoyl chloride, benzenesulfonyl chloride, p-chlorobenzenesulfonyl chloride, p-methylbenzenesulfonyl chloride, 4-benzoylbenzoyl chloride, and mixtures thereof.

[0202] Advantageously, the chain limiter is an electrophilic chain limiter selected from benzoyl chloride, p-fluorobenzoyl chloride, 3,5-difluorobenzoyl chloride, or a mixture thereof. These chain limiters are easy to measure, have a low cost price, and ensure good thermal stability of the polymer because they are in liquid form at room temperature.

[0203] According to certain embodiments, benzoyl chloride is used as chain limiter.

[0204] According to certain embodiments, p-fluorobenzoyl chloride is used as the chain limiter.

[0205] According to certain embodiments, 3,5-difluorobenzoyl chloride is used as the chain limiter.

[0206] The use of dispersants in the reaction medium is optional. The process according to the present invention generally eliminates the need to use such agents because it can effectively minimize fouling within the reactor via increased control over the reactor temperature.

[0207] According to a preferred embodiment, no dispersant is added to the reaction medium. This has multiple advantages in particular: it avoids excessive consumption of the introduced Lewis acid and / or promotes the upgrading of process effluents, in particular effluents containing Lewis acids.

[0208] Since the polymerization reaction is a polycondensation reaction, the aromatic ether or the mixture of aromatic ethers is introduced into the reaction mixture in a substantially stoichiometric amount relative to the acid chloride or the mixture of acid chlorides.

[0209] The molar ratio of the aromatic ether(s) relative to the acid chloride(s) which has been introduced in total into the reaction mixture at the end of the step of contacting is preferentially from 0.9 / 1.1 to 1.1 / 0.9.

[0210] According to advantageous embodiments, the aromatic ether(s) are introduced in excess relative to the acid chloride(s), preferentially with a molar ratio of aromatic ether(s) relative to the acid chloride(s) of 1.001 to 1.1. In these embodiments, if a chain limiter is used, it is preferentially an electrophilic chain limiter, for example and advantageously benzoyl chloride, or p-fluorobenzoyl chloride, or 3,5-difluorobenzoyl chloride.

[0211] The molar ratio of the aromatic ether(s) introduced in total into the reaction mixture at the end of the polymerization relative to the reaction solvent(s) is preferentially at least equal to 0.005, very preferentially greater than or equal to 0.008 and more preferentially greater than or equal to 0.010.

[0212] As described in detail below, the process according to the invention makes it possible to obtain polymer particles of generally smaller size and with generally more uniform distribution than prior art processes involving the preparation of a cold premix followed by dispersion of this premix in a preheated reaction solvent. A more compact suspension of the polymer particles in the reaction solvent is thus obtained, enabling the process to be carried out in generally smaller amounts of reaction solvent.

[0213] Therefore, according to certain embodiments, the molar ratio of the (one or more) aromatic ethers introduced into the reaction mixture at the end of the polymerization relative to the (one or more) reaction solvents 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.

[0214] In contrast, given that the less solvent the reaction mixture contains, the easier it is to form scale during polymerization, especially in the absence of a dispersant, the molar ratio of the aromatic ether(s) introduced into the reaction mixture at the end of the polymerization relative to the reaction solvent(s) 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.

[0215] Therefore, according to certain embodiments, the molar ratio of (one or more) aromatic ethers introduced into the reaction mixture relative to the total (one or more) reaction solvents 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 (one or more) aromatic ethers introduced into the reaction mixture relative to (one or more) reaction solvents may be especially from 0.011 to 0.022, from 0.012 to 0.022, from 0.013 to 0.022, from 0.014 to 0.022, from 0.015 to 0.022, from 0.016 to 0.022, or from 0.017 to 0.022.

[0216] The molar ratio of Lewis acid introduced in total into the reaction mixture at the end of the step of contacting relative to the aromatic ether(s) is preferentially from 5.0 to 7.0 and very preferentially from 5.5 to 6.5.

[0217] The process according to the invention involves contacting the compounds involved in the polymerization reaction. This step particularly involves contacting the following reactants in all or some of the reaction solvent: (one or more) aromatic ethers, (one or more) acyl chlorides, and Lewis acids. These different compounds can theoretically be mixed together in any order so that at the end of the contacting step, 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene (considered as a whole where appropriate) is substantially insoluble in the reaction solvent.

[0218] For the purposes of the present invention, the term "reaction mixture" is used when all or a portion of the aromatic ether(s), all or a portion of the acid chloride(s), and all or a portion of the Lewis acid are contacted in all or a portion of the solvent. In other words, the "reaction mixture" begins to exist when polymerization can be initiated, i.e., when all or a portion of the aromatic ether(s), all or a portion of the acid chloride(s), and all or a portion of the Lewis acid have been contacted.

[0219] The contacting step is terminated when all of the aromatic ether or the mixture of aromatic ethers, the acid chloride or the mixture of acid chlorides and the Lewis acid have been contacted. Thus, at the end of the contacting step the reaction mixture comprises all of the aromatic ether or the mixture of aromatic ethers, all of the acid chloride or the mixture of acid chlorides, all of the Lewis acid, all or a portion of the reaction solvent, and optionally all or a portion of the chain limiter or the mixture of chain limiters.

[0220] According to certain advantageous embodiments, the reaction mixture is maintained at a temperature T0 during the step of contacting the compounds to ensure that 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene (considered as a whole where appropriate) are substantially insoluble in the reaction solvent at the end of the step of contacting.

[0221] The temperature T0 is advantageously less than or equal to 5° C. It is preferentially less than or equal to 0° C. and very preferentially less than or equal to −5° C.

[0222] According to certain embodiments, all of the reaction solvent is introduced during the contacting step. p This is especially the case when the aspect does not play a direct role.

[0223] According to other embodiments, only a portion of the reaction solvent is introduced during the step of contacting, and the other portion of the solvent can be added especially just after the contacting is completed and before the step of gradually heating or at the beginning of the step of gradually heating. Alternatively or additionally, the other portion of the solvent can be added during the step of gradually heating to directly contribute to the performance of this step. In other words, the reaction solvent preheated to a temperature higher than that of the reaction mixture can be added thereto to increase its temperature.

[0224] According to certain embodiments, a mass fraction of solvent from 0.15 to 0.95 may be introduced before the contacting step is completed.

[0225] According to certain embodiments, a mass fraction of the reaction solvent from 0.15 to 0.25, or from 0.25 to 0.40, or from 0.40 to 0.55, or from 0.55 to 0.70, or from 0.70 to 0.85, or from 0.85 to 0.95 may be introduced before the contacting step is completed.

[0226] According to an advantageous embodiment, from 0.15 to 0.55, and preferentially from 0.25 to 0.40, of reaction solvent are introduced before the end of the contacting step. These embodiments make it possible in particular to ensure that 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene (considered as a whole) are substantially in the form of a suspension at the end of the contacting step.

[0227] According to an advantageous embodiment, the various compounds, in particular the reactants, can be added in two stages.

[0228] In the first stage, the two reactants are mixed together. In the second stage, the third reactant is added to the mixture previously obtained. Subsequently, the medium can be maintained at a temperature less than or equal to T0 at the latest between the beginning of the second stage when the third reactant is added and the end of the second stage when the third reactant is stopped.

[0229] According to a first embodiment, the first stage involves preparing a mixture comprising the whole of the aromatic ether or the mixture of aromatic ethers, and the whole of the acyl chloride or the mixture of acyl chlorides in all or some of the reaction solvent. The second stage involves adding the whole of the Lewis acid to the mixture obtained in the first stage.

[0230] According to a second embodiment, the first stage involves preparing a mixture comprising the whole of the acyl chloride or the mixture of acyl chlorides and the whole of the Lewis acid in the whole or some of the reaction solvent. The second stage involves adding the whole of the aromatic ether or the mixture of aromatic ethers to the mixture obtained in the first stage.

[0231] The following paragraphs describe in detail these two particularly advantageous embodiments for carrying out the step of contacting the chemical compounds in the reactor.The process according to the invention is not limited to these exemplary embodiments.

[0232] A first advantageous implementation can be carried out according to the following sequence:

[0233] First, all or some of the reaction solvent is introduced into the reactor. Secondly, aromatic ether or a mixture of aromatic ethers is added and dispersed in the reaction solvent in the reactor under stirring. Third, in order to ensure that there is no trace of water in the reactor, distillation is performed and the reactor head space is also inertized with nitrogen. Alternatively or additionally, a dehydrating agent, especially a small amount of aluminum chloride, can be added to eliminate the last trace of water. The reaction of aluminum chloride with water forms aluminum hydroxide and hydrogen chloride (according to this alternative, the medium already contains a very small amount of even traces of aluminum chloride in this step). Fourth, the mixture of acyl chloride or acyl chlorides is placed in the reactor under stirring. Fifth, Lewis acid is introduced under stirring. Since the complexation of Lewis acid with (one or more) acyl chlorides is an exothermic reaction, Lewis acid is fully and slowly added to the reactor so that the reaction mixture can be maintained at a temperature of less than or equal to 5°C. The step of adding Lewis acid can generally last from 15 minutes to 12 hours. On an industrial scale, the step of adding Lewis acid preferentially lasts from 25 minutes to 6 hours, and more preferably from 30 minutes to 4 hours.

[0234] When 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 T 0 may be observed where appropriate. This optional homogenization step may preferentially last less than 15 minutes, or less than 10 minutes, or less than 5 minutes.

[0235] The second advantageous embodiment can be carried out according to the following sequence:

[0236] First, all or some of the reaction solvent is introduced into the reactor. Secondly, in order to ensure that no traces of water are present in the reactor, a distillation is carried out and the reactor headspace is also inerted with nitrogen. Alternatively or additionally, a dehydrating agent, especially a small amount of aluminum chloride, may be added to eliminate the last traces of water. The reaction of aluminum chloride with water forms aluminum hydroxide and hydrogen chloride (according to this alternative, the medium already contains very small amounts of aluminum chloride in this step).

[0237] Third, the acyl chloride or a mixture of acyl chlorides is placed in a reactor under stirring. Fourth, a Lewis acid is introduced under stirring. Since the complexation of Lewis acid with (one or more) acyl chlorides is an exothermic reaction, Lewis acid is fully and slowly added to the reactor so that the reaction mixture can be maintained at a temperature of less than or equal to 5° C. The step of adding Lewis acid can generally last from 15 minutes to 12 hours. On an industrial scale, the step of adding Lewis acid preferably lasts from 25 minutes to 6 hours, and more preferably from 30 minutes to 4 hours.

[0238] Fifth, when all of the Lewis acid has been completely introduced, an aromatic ether or a mixture of aromatic ethers is introduced to form a reaction mixture.

[0239] An optional step of homogenizing the reaction mixture may be observed where appropriate. The optional homogenization step may preferentially last less than 15 minutes, or less than 10 minutes, or less than 5 minutes.

[0240] The process according to the invention also comprises the polymerization of the reaction mixture, said polymerization being carried out at least in part at a temperature Tp greater than or equal to 50°C. Sufficiently high polymerization temperatures allow for rapid polymerization kinetics. 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.

[0241] The temperature Tp is generally less than or equal to 120° C. in order to minimize parasitic reactions competing with the polymerization reaction. Preferentially, 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.

[0242] Advantageously, the temperature Tp may be selected in the range of 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.

[0243] Preferably, under stirring, the reaction mixture is maintained at a temperature Tp for a certain time until the desired degree of polymerization is obtained. The higher the temperature Tp, the shorter the time the reaction mixture is maintained at Tp. This time generally ranges from 1 minute to 300 minutes, preferably from 5 minutes to 180 minutes, and extremely preferably from 10 minutes to 100 minutes.

[0244] When the reaction has reached the desired extent of polymerization, the starting mixture is referred to as the "product mixture."

[0245] The present invention is characterized in that the process comprises a step of gradually heating the reaction mixture until the polymerization reaction is accelerated, the step of gradually heating is performed at an average heating rate selected from the range of from 0.65° C. / min to 2.5° C. / min.

[0246] The stepwise heating step is preferably carried out with an average heating rate ranging from 0.70°C / min to 2.2°C / min, preferably with an average heating rate ranging from 0.75°C / min to 2.0°C / min, and more preferably with an average heating rate ranging from 0.8°C / min to 1.8°C / min.

[0247] The gradual heating step is at the initial temperature T i and the final temperature T f Between, temperature T i and T f It is like this: T0≤T i <T f ≤T p .

[0248] According to some embodiments, T0≤T i ≤T0+30℃, or T0≤T i ≤T0+20℃, or T0≤T i ≤T0+15℃.

[0249] According to certain embodiments, T p -45<T f ≤T p , or T p -35<T f ≤T p , or T p -25<T f ≤T p, or T p -15<T f ≤T p , or T p -10<T f ≤T p .

[0250] According to certain embodiments, T f -T i ≥25℃、T f -T i ≥30℃, or T f -T i ≥35℃, or T f -T i ≥40℃.

[0251] According to a particular embodiment, the gradual heating step may be performed between T0 and T p Between.

[0252] The acceleration of the polymerization reaction is a characteristic of the process according to the invention. * occurs, the temperature itself depending at least in part on the performance (conduct) of the stepwise heating step itself.

[0253] Temperature T * The acceleration of the polymerization can be assessed as marked by a sudden increase in the production of hydrogen chloride.

[0254] Alternatively, the temperature T * The acceleration of polymerization can be assessed as marked by a sudden increase in the heat flow emitted through the reaction mixture.

[0255] To illustrate the latter, Figure 1 The jacket temperature of a jacketed reactor, such as the reactor used to carry out the Examples, is shown as a function of time (dashed line) and the temperature of the reaction mixture within the reactor (solid curve).

[0256] Set the nominal temperature ramp to obtain a range from temperature T i To temperature T f Temperature ramp inside the reactor.

[0257] Temperature T * Corresponding to the temperature at which the temperature of the reaction mixture rises faster than the temperature imposed by the temperature control means of the reactor, the reactor is forced to temporarily cool the reaction mixture.

[0258] One result of accelerated polymerization is that after reaching the temperature T * This was soon followed by a very rapid increase in the viscosity of the reaction mixture.

[0259] It is estimated that the temperature T that can be generally observed for the process according to the invention is* Between 20°C and 80°C. Temperature T * It may especially 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.

[0260] According to certain embodiments, T i ≤T * -10℃, preferably T i ≤T * -20°C, and most preferably T i ≤T * -25℃.

[0261] According to certain embodiments, T *+ 5℃≤T p , preferably T * +10℃≤T p , and most preferably T * +15℃≤T p .

[0262] According to certain embodiments, the stepwise heating step may be performed by a sequence of temperature steps, the temperature difference between each step not exceeding 15° C., preferably not exceeding 10° C., and very preferably not exceeding 5° C. The successive stages may be obtained by successive additions of small portions of the preheated reaction solvent.

[0263] According to certain embodiments, the stepwise heating step is performed by one or more temperature ramps with a heating rate ranging from 0.65°C / min to 2.5°C / min, preferentially by a heating rate ranging from 0.70°C / min to 2.2°C / min, preferentially by a heating rate ranging from 0.75°C / min to 2.0°C / min, and more preferably by a heating rate ranging from 0.8°C / min to 1.8°C / min.

[0264] Such a temperature ramp can be obtained with the aid of heating means incorporated into the reactor, the addition of a small portion of preheated reaction solvent, or a combination of both approaches.

[0265] According to certain embodiments, the reaction solvent may be preheated to a temperature that may be greater than T p and added to the reaction mixture either continuously or in portions.

[0266] According to certain embodiments, the step of gradually heating is performed at T i and T fThe heating is performed by a single temperature ramp with a heating rate ranging from 0.65°C / min to 2.5°C / min, preferentially by a heating rate ranging from 0.70°C / min to 2.2°C / min, preferentially by a heating rate ranging from 0.75°C / min to 2.0°C / min, and more preferably by a heating rate ranging from 0.8°C / min to 1.8°C / min.

[0267] According to a particular embodiment, the step of gradually heating may be performed by heating the mixture at a temperature 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 ... 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.

[0268] According to certain embodiments, the gradual heating step may be performed by a combination of temperature stages and temperature ramps by the means mentioned above.

[0269] In embodiments where a chain limiter is used, the chain limiter may be introduced prior to polymerization or during polymerization.

[0270] It can be introduced all at once or in batches.

[0271] Advantageously, when the temperature T is reached *More preferably, the chain limiter is completely introduced before the gradual heating step.

[0272] According to certain embodiments, the chain-limiting agent may be introduced entirely during contacting of the reactants.

[0273] In particular, in both embodiments of contacting the reactants described in detail above, it may be advantageous to introduce the chain limiter prior to the introduction of the last reactant.

[0274] According to an advantageous embodiment, the hydrogen chloride produced during the polymerization reaction is extracted from the reactor during the polymerization reaction to promote the polymerization reaction. For this purpose, all or some of the polymerization can be carried out under reduced pressure at an absolute pressure of less than or equal to 900mbar, or less than or equal to 800mbar, or less than or equal to 700mbar, or less than or equal to 600mbar, or less than or equal to 500mbar, or less than or equal to 400mbar, or less than or equal to 300mbar, or less than or equal to 200mbar, or less than or equal to 100mbar. Alternatively or additionally, an inert gas such as helium, argon or dinitrogen (nitrogen) is bubbled into the reaction mixture. However, this method is not preferred because it produces other turbulence in the reaction mixture and makes it more difficult to control the temperature in the reactor.

[0275] The process can be carried out in one reactor or in a series of multiple reactors.

[0276] According to certain embodiments, the contacting, the gradual heating step, and the polymerization are performed in a single reactor.

[0277] According to certain embodiments, the contacting is performed in a first reactor and the stepwise heating step and the polymerizing are performed in a second reactor.

[0278] The reactor that can be used to carry out the present invention can be, for example, a glass reactor, an enamelled reactor, or a reactor having metallurgical corrosion resistance.

[0279] The reactor preferably has temperature control means and means for measuring the temperature therein. The reactor may in particular comprise one or more temperature sensors therein and be configured to cool and / or heat the reaction medium.

[0280] The reactor that can be used to carry out the present invention is preferably equipped with a stirring device such as a mechanical stirrer (for example, it can contain one or more stirring rotors) or a recirculation loop with a pump. The reaction mixture is preferentially stirred during contacting the reactants, the stepwise heating steps and the polymerization to allow good homogenization of the chemical compounds and uniform heat transfer within the reaction mixture.

[0281] The reactor that can be used for the gradual heating step and the polymerization advantageously comprises a dual-flow stirring system, which keeps the reaction mixture in motion, especially at the level of the side walls of the reactor, and a tank bottom turbine, which keeps the reaction mixture in motion, especially at the level of the tank bottom wall, and thus prevents accelerated fouling of the reactor.

[0282] After the polymerization reaction has been completed to the desired degree of polymerization, the process of the invention may comprise purifying the polyetherketoneketone from the product mixture in a manner known per se. This has been described, for example, in EP3655458.

[0283] In particular, such purification makes it possible to separate the solvent, the catalyst, the unreacted reactants, and any reaction by-products from the polymer itself.

[0284] In particular, purification generally comprises the step of contacting the product mixture with a protic solvent to recover a first phase comprising the Lewis acid and a second phase comprising the polyetherketoneketone.

[0285] 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 no greater than 3, or no greater than 2. The dissociation of the polyetherketoneketone / Lewis acid complex is more effective when an acidic solution is used.

[0286] Solvent mixtures can also be used, such as water-organic solvents, for example aqueous solutions mixed with methanol, ethanol, isopropanol, or acetic acid. Preferentially, mixtures of aqueous solutions and alcohols (especially methanol, ethanol, or isopropanol) are used, which contain 95% to 60% by weight, preferably 80% to 95% by weight of alcohol.

[0287] Contacting the product mixture with a protic solvent produces a first phase (containing the protic solvent) and a second phase (containing the reaction solvent). The Lewis acid is present primarily in dissolved form in the first phase, whereas the polyetherketoneketone is present primarily in precipitated form in the second phase.

[0288] 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.

[0289] The dry solids content of the crude polyetherketoneketone product at the end of the solid / liquid separation step is preferably between 10 and 90 wt. %, more preferably between 20 and 80 wt. %, and even more preferably between 30 and 60 wt. %.

[0290] The liquid effluent containing the first and second phases may optionally be separated for separate recovery, preferably by decantation, for possible reuse. A surfactant may be added to facilitate phase separation. When the Lewis acid is aluminum chloride, the first phase advantageously contains it in an appropriate proportion so that it can be directly recycled for use in the water treatment / sludge flocculation process.

[0291] According to a preferred embodiment, the crude polyetherketoneketone product at the end of the aforementioned solid / liquid separation step can be further purified by washing with one or more protic solvents.

[0292] 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.

[0293] After or simultaneously with the washing step, a further solid / liquid separation step may be performed.

[0294] According to an advantageous embodiment, a centrifugal filter device is used, so that washing and solid / liquid separation can be performed simultaneously in said device without resuspension of the product.

[0295] After the final solid / liquid separation, the recovered solid is advantageously dried.

[0296] The drying step can be carried out conventionally, for example at a temperature ranging from 100° C. to 280° C. and at atmospheric pressure or preferably at reduced pressure, for example at a pressure of 30 mbar. After drying, the polyetherketoneketone generally has a proportion of reaction solvent less than or equal to 50 ppm by weight, preferentially less than or equal to 25 ppm by weight, and more preferably less than or equal to 15 ppm by weight, relative to the weight of the polymer.

[0297] The polymer produced according to the process of the present invention generally has an intrinsic viscosity of 0.4 to 2.0 dL / g, and preferably 0.7 to 1.5 dL / g, as measured in accordance with standard ISO 307-2009 applicable to PEKK using a viscometer such as an Ubbelohde suspension grade viscometer (capillary inner diameter of 1.03 mm) at 25°C in a 96.00% sulfuric acid solution (mass fraction) at a concentration of 0.0005 g / mL.

[0298] According to certain embodiments, the polyetherketoneketone has an intrinsic viscosity of from 0.4 to 0.5 dL / g, or from 0.5 to 0.6 dL / g, or from 0.6 to 0.7 dL / g, or from 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.

[0299] According to a particular embodiment, the polyetherketoneketone has an intrinsic viscosity of from 0.98 dL / g to 1.4 dL / g.

[0300] The polyetherketoneketone produced according to the invention has the advantage that it does not contain any dispersant(s), in particular those described in WO 9 523 821 and in US 2012 / 0263953 in the form of impurity(s).

[0301] The polyetherketoneketone according to the invention therefore does not contain benzoic acid or its derivatives used as dispersants, as described in US 2012 / 0263953. The polyetherketoneketone in particular does not contain any of the following compounds: benzoic acid, methylbenzoic acid, sodium benzoate, magnesium benzoate, aluminum benzoate, methyl benzoate and benzenesulfonic acid. In particular, the polyetherketoneketone does not contain any benzoic acid.

[0302] The polyetherketoneketone according to the invention therefore also does not comprise any other polymers used as dispersants, such as the polymers described in WO 9523 821. The polyetherketoneketone in particular does not contain any copolymers of aliphatic vinyl compounds and N-vinylpyrrolidone.

[0303] In embodiments where a chain limiter such as benzoyl chloride, p-fluorobenzoyl chloride, or 3,5-difluorobenzoyl chloride is used in the polyetherketoneketone manufacturing process, the polyetherketoneketone has a high proportion of chain ends derived from the chain limiter for a given viscosity relative to prior art polymers.

[0304] Polyetherketoneketone preferably satisfies the following inequality:

[0305] IV * FDC (LDC) ≥LIM;

[0306] in:

[0307] IV denotes the intrinsic viscosity of the polyetherketoneketone measured according to standard ISO 307-2009 and expressed in dL / g.

[0308] FDC (LDC)represents the molar concentration of the groups originating from the chain limiter relative to the total weight of the polymer, expressed in microequivalents of limiter per gram of polymer, and

[0309] LIM is an extreme value, equal to at least 40.

[0310] According to some embodiments, the value 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.

[0311] The polyetherketoneketone obtained by the process according to the invention is generally in the form of flakes of fairly uniform size. In particular and advantageously, the polymer has almost no large flakes. This is particularly advantageous for facilitating purification. In particular, the extraction of aluminum chloride and / or impurities resulting from the polymerization is simpler and more effective on particles of reduced size. In addition, drying can also be carried out faster.

[0312] According to certain embodiments, the polyetherketoneketone flakes form a powder, for which the mass proportion of particles having a size strictly greater than 630 microns is less than or equal to 25%, preferentially less than or equal to 15%, and more preferentially less than or equal to 10%, relative to the total weight of the powder, which is obtained by screening using a sieve with a mesh size equal to 630 microns.

[0313] According to certain embodiments, the polyetherketoneketone flakes form a coarse powder for which the mass proportion of particles having a size strictly greater than 450 microns is less than or equal to 75%, preferentially less than or equal to 50%, more preferentially less than or equal to 25%, even more preferentially less than or equal to 20%, and most preferably less than or equal to 16%, relative to the total weight of the powder, as obtained by screening using a sieve with a mesh size equal to 630 microns.

[0314] According to certain embodiments, the polyetherketoneketone flakes formed into a coarse powder have a mass fraction greater than or equal to 200 kg / m 3 The tap density of the polymer is preferably 1000 g / cm2, as measured in the examples. A sufficiently high tap density has various advantages depending on the intended use. In pelletizing, it reduces the amount of air introduced into the extruder and improves the melt stability of the polymer. In laser sintering, it improves the cohesion of the powder bed after grinding into a fine powder. The tap density is generally kept below 400 kg / m2. 3 It may in particular be less than 350 kg / m 3 , or even less than or equal to 300kg / m 3 .

[0315] Furthermore, according to certain embodiments, the polyetherketoneketone flakes forming the coarse powder have a thickness of less than or equal to 4 μm. 2The specific surface area may be less than or equal to 3 m 2 / g, or less than or equal to 2.5m 2 / g. It is generally maintained at 0.1m 2 / g or more. It may be especially greater than or equal to 1 m 2 / g.

[0316] Example

[0317] Example 1

[0318] A jacketed reactor (R2) was used which was equipped with a stirrer comprising “two superimposed dual-flow rotors” and a system for inerting the head space under a nitrogen flow.

[0319] Firstly, o-dichlorobenzene and 1,4-bis(4-phenoxybenzoyl)benzene were added to the reactor R2 with stirring in a mass ratio of 1,4-bis(4-phenoxybenzoyl)benzene / o-dichlorobenzene equal to 0.041.

[0320] Dynamic vacuum distillation (90° C., 150 mbar) and inertization with nitrogen were performed to eliminate any traces of water remaining in the reactor.

[0321] A mixture of terephthaloyl chloride and isophthaloyl chloride is added to the reaction medium with stirring in a molar ratio of terephthaloyl chloride to isophthaloyl chloride equal to 0.45, in substantially equimolar amounts but slightly insufficient relative to 1,4-bis(4-phenoxybenzoyl)benzene. The molar ratio of 1,4-bis(4-phenoxybenzoyl)benzene relative to the mixture of terephthaloyl chloride and isophthaloyl chloride is 1.03.

[0322] Benzoyl chloride was also added as a chain limiter in a molar ratio relative to 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.042 with stirring.

[0323] The reaction medium in reactor R2 is then cooled to -5°C. Solid aluminum chloride is slowly added to the reaction medium under stirring over about 45 minutes to form a reaction mixture, the temperature of the reaction mixture being maintained at about -5°C throughout the addition step. The molar ratio of aluminum chloride relative to 1,4-bis(4-phenoxybenzoyl)benzene is equal to 6.3.

[0324] When all the aluminum chloride has been added, the temperature in reactor R2 is increased stepwise with a temperature ramp of 0.8° C. / min until a reaction mixture temperature equal to 90° C. is reached. The reaction mixture is then kept at a temperature of 90° C. for a period of 30 minutes.

[0325] The product mixture is then cooled to a temperature of less than or equal to 50° C. It is purified by mixing with an aqueous hydrochloric acid solution having a pH ≤ 3 and solid / liquid separation using a filter. The crude polymer is then washed three times by resuspension and subsequent filtration, the washing solutions used being successively methanol, hydrochloric acid solution, and water.

[0326] The purified polymer was finally dried under vacuum (30 mbar) at 180° C. for 48 hours.

[0327] Example 2

[0328] Example 2 corresponds to an experiment under the same conditions as Example 1 except that benzoyl chloride is added in a molar ratio relative to 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.029 and a temperature ramp of 1°C / min is carried out to raise the reaction mixture to a final polymerization temperature of 90°C.

[0329] Example 3

[0330] Example 3 corresponds to an experiment under the same conditions as Example 1 except that it was carried out with a temperature ramp of 1.5° C. / min.

[0331] Example 4

[0332] Example 4 corresponds to an experiment under the same conditions as Example 2 except that it was carried out with a temperature ramp of 1.5° C. / min.

[0333] Example 5

[0334] Example 5 corresponds to an experiment under the same conditions as Example 3 except that the 1,4-bis(4-phenoxybenzoyl)benzene / o-dichlorobenzene mass ratio is equal to 0.056 and benzoyl chloride is added in a molar ratio relative to 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.049.

[0335] Example 6

[0336] Example 6 corresponds to an experiment under conditions similar to those of Example 1 except that it was carried out with a temperature ramp of 0.75° C. / min.

[0337] Furthermore, the reaction solvent was added partially in two batches. The first portion (about 66%) was introduced with 1,4-bis(4-phenoxybenzoyl)benzene and the acid chloride and then cooled to -5°C, followed by continued introduction of aluminum chloride. When all the aluminum chloride had been added, the second portion of the solvent portion (about 33%) preheated to 125°C was added continuously during the temperature rise.

[0338] Comparative Example 1

[0339] Comparative Example 1 corresponds to an experiment under the same conditions as Example 1 except that it was carried out at a temperature ramp of 0.6° C. / min.

[0340] Comparative Example 2

[0341] Example 2 corresponds to an experiment under the same conditions as Example 1 except that it was carried out with a temperature ramp of 3.0° C. / min and benzoyl chloride was added in a molar ratio relative to 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.049.

[0342] Comparative Example 3

[0343] Comparative Example 3 corresponds to an experiment under the same conditions as Example 3 except that the reaction medium was cooled and maintained at a temperature of 7° C. to carry out the step of contacting with aluminum trichloride.

[0344] Comparative Example 4

[0345] Two jacketed reactors (R1) and (R2) equipped with a stirring system and a system for inerting the head space under a nitrogen flow were used.

[0346] 1,4-Bis(4-phenoxybenzoyl)benzene, o-dichlorobenzene, terephthaloyl and isophthaloyl chlorides, aluminum trichloride and benzoyl chloride are introduced into the reaction medium in the same proportions as in Example 2 but according to a process corresponding to the prior art procedure consisting in dispersing the cold premix in the preheated reaction solvent.

[0347] First, o-dichlorobenzene with a fraction S=0.31 (the mole fraction of o-dichlorobenzene expressed relative to the total amount of o-dichlorobenzene used in the polymerization reaction) and 1,4-bis(4-phenoxybenzoyl)benzene were added to the reactor R1 with stirring.

[0348] Dynamic vacuum distillation and inertization with nitrogen were performed to remove any traces of residual water from the reaction medium.

[0349] The mixture of terephthaloyl chloride and isophthaloyl chloride and benzoyl chloride were then added with stirring.

[0350] The reaction medium in reactor R1 is then cooled to -5°C. Aluminum trichloride is added to the reaction medium with stirring to form a reaction mixture, the temperature of the reaction mixture being maintained at about -5°C throughout the addition step.

[0351] When all the aluminum chloride has been added, the contents of reactor R1 are transferred with stirring into reactor R2, which contains o-dichlorobenzene with a fraction 1-S=0.69 brought to and maintained at a temperature of 85° C. The reaction mixture is then kept at this temperature for one hour.

[0352] The same purification process of the product mixture as in Example 1 was then carried out.

[0353] Comparative Example 5

[0354] Comparative Example 5 corresponds to an experiment under the same conditions as Comparative Example 4 except that benzoyl chloride was added in a molar ratio relative to 1,4-bis(4-phenoxybenzoyl)benzene equal to 0.035.

[0355] result

[0356] The yield for each process was calculated according to the following formula:

[0357] R(%)=100*m 聚合物 / [0.996m EKKE +0.651(m TCl +m ICl )+0.748m BzCl ];

[0358] in:

[0359] m 聚合物 is the mass of polymer recovered at the end of the process;

[0360] m EKKE 、m TCl 、m ICl , and m BzCl is the respective mass of 1,4-bis(4-phenoxybenzoyl)benzene, terephthaloyl chloride, isophthaloyl chloride, and benzoyl chloride introduced into the reaction mixture.

[0361] In the various experiments above, the polymer was obtained in the form of porous pellets. It was characterized by viscosity measurement, evaluation of the amount of benzoyl chain ends, screening analysis of its particle size distribution, measurement of its tap density, and measurement of its specific surface area.

[0362] Its intrinsic viscosity (IV) is expressed in dL / g and is measured according to standard ISO 307-2009 for PEKK using a viscometer such as an Ubbelohde suspension grade viscometer (capillary inner diameter of 1.03 mm) at 25°C in a 96.00% sulfuric acid solution (mass fraction) at a concentration of 0.0005 g / mL.

[0363] Molar concentration of benzoyl chain ends (FDCBZ ) is expressed as micro equivalents of benzoyl chain ends per gram of polymer and can be determined by NMR methods. The analysis is performed by proton NMR (Avance 400III HD, Avance 400NEO). The sample is dissolved in dichloromethane-d2 at room temperature with the addition of trifluoroacetic acid-d. All lines observed between 8.8ppm and 6.8ppm correspond to the protons of the polyetherketoneketone units. At 7.58ppm, a line attributable to the b protons of the benzoyl chain ends appears. By integrating all lines in the spectrum and combining the line at 7.58ppm, the benzoyl chain end content of the polymer can be determined.

[0364] The particle size distribution of the flakes, in particular the proportion of flakes having a size strictly greater than 450 microns (%>450 μm) and the proportion of flakes having a size strictly greater than 630 microns (%>630 μm), were evaluated by screening. More specifically, the AS200 sold by the company Retsch was used. Vibrating sieving machine with a sieve diameter of 200 mm and a sieve opening size suitable for the measured size (450 μm for measuring the proportion of pieces with a size strictly greater than 450 microns and 630 μm for measuring the proportion of pieces with a size strictly greater than 630 microns). The product to be screened is placed on the upper sieve (about 60 g) and the machine is set with an amplitude of 2 mm in intermittent activation mode (10 s).

[0365] The sieving time is determined as follows: the sieving is activated for 5 minutes, at the end of which the sieve and the container receiving the particles that have passed through the sieve are weighed. The entire unit is placed back on the sieve for another 5 minutes. If the sieve mass remains unchanged, the sieving is complete. If this is not the case, the sieving is repeated until the weighed mass is stable.

[0366] The tap density is measured according to standard ISO 1068-1975(F) in the following manner:

[0367] - Condition the powder at 23°C and 50% RH for 24 hours;

[0368] - Introduce a certain volume of powder (tablets) into a precisely graduated 250 ml glass cylinder;

[0369] - If necessary, level the free surface of the powder without tapping it and record the volume V0;

[0370] - weigh the measuring cylinder with the powder on a balance with an accuracy of 0.1 g, which has been previously tared;

[0371] - Place the cylinder on the plate of a STAV 2003 tapping machine;

[0372] - Knock it 1250 times by dropping it and record the volume V1;

[0373] - Knock it 1250 times by dropping it and record the volume V2;

[0374] - Repeat the tapping operation until two equivalent volumes Vi are obtained.

[0375] -Record Vf corresponding to the same volume Vi.

[0376] The tap density is the mass of the powder introduced divided by Vf. It is expressed in kg / m 3 express.

[0377] The specific surface area (SSA) represents the ratio of the actual surface area of ​​a powder to the amount of material in the powder. 2 It is measured by degassing, adsorption of nitrogen onto the powder (tablets) and then determining using the Brunauer-Emmett-Teller (BET) equation according to standard ISO 9277:2022.

[0378] All the results are summarized in the following table:

[0379]

[0380] Table 1 - "ND" (not determined) means that no measurement was made.

[0381] #experiment <![CDATA[Tap density (kg / m 3 )]]> <![CDATA[SSA(m 2 / g)]]> Example 1 214 ND Example 2 202 ND Example 3 234 ND Example 4 200 2.2 Example 5 285 ND Example 6 218 1.8 Comparative Example 1 223 ND Comparative Example 2 117 ND Comparative Example 3 199 ND Comparative Example 4 ND 5.9 Comparative Example 5 180 ND

[0382] Table 2

[0383] 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 polyetherketoneketones in higher yields than the prior art process consisting in preparing a cold premix and dispersing it in a preheated solvent (Table 1). The process allows in particular to obtain polymers having high viscosities and at the same time incorporating large amounts of chain limiters as chemical chain end functions. The process also allows to obtain smaller flake sizes.

[0384] Comparison of Examples 1 to 5 with Comparative Examples 1 and 2 shows the necessary choice regarding the average heating rate for the stepwise heating step. In particular, if the average heating rate during the stepwise heating step is too slow or too fast, poor yields are obtained. These poor yields are even lower than those obtained via prior art processes consisting in preparing a cold premix and dispersing it in a preheated solvent (see Comparative Examples 4 and 5).

[0385] Comparison of Examples 1 and 3 with Comparative Example 3 shows that, in the case where the reactants are contacted for a sufficiently long time and 1,4-bis(4-phenoxybenzoylbenzene) is introduced into the entire reaction solvent, a sufficiently low contact temperature is required to allow 1,4-bis(4-phenoxybenzoylbenzene) to remain suspended in the reaction mixture for a sufficiently long time, thereby being able to accelerate the delayed polymerization reaction and ultimately improve the yield of the process.

[0386] Comparison of Example 5 with Example 3 shows that the process according to the invention can be carried out with higher concentrations of the chemical compounds in the reaction solvent.

[0387] Comparison of Example 4 with Comparative Example 4 shows that, for the molar concentration of benzoyl chain ends added to the reaction mixture, the process according to the invention makes it possible to obtain a polymer having a higher viscosity, whereas the prior art process consists in preparing a cold reaction premix and dispersing it in a preheated solvent. Furthermore, the comparison shows that, for the molar concentration of benzoyl chain ends added to the reaction mixture, the process according to the invention provides a polymer having a higher proportion of chain ends derived from the chain limiter.

[0388] Comparison of Example 6 with Example 1 shows that the reaction solvent can be introduced in its entirety during contacting of the reactants or, on the contrary, in a portioned manner, and that a portion of the reaction solvent can be advantageously used to carry out the gradual heating step.

[0389] A comparison of Examples 1 to 6 with Comparative Examples 1 and 2 shows that the higher the temperature ramp, the lower the tap density of the obtained tablets (Table 2). In addition, a comparison of Examples 1 to 6 with Comparative Examples 3 and 5 shows that the tap density of the coarse powder according to the invention is higher than the tap density of the powder obtained by introducing the cold premix into the hot reaction solvent.

[0390] Comparison of Example 4 with Comparative Example 4 shows that the sheets obtained via the process according to the invention have a smaller specific surface area (Table 2).

[0391] Initial complex viscosity was measured at 1 Hz, 380° C. under nitrogen (first measurement point after sample insertion and after 5 minutes of oven stabilization):

[0392] ■ a polyetherketoneketone produced according to US 2012 / 0263953 using benzoic acid as a dispersant, wherein the T / I ratio is 70 / 30, the intrinsic viscosity is 1.13 dL / g, and the mass proportion of residual benzoic acid relative to the weight of the polymer is 0.6 wt% (gas chromatography),

[0393] ■ The polyetherketoneketone according to Example 4 also has an intrinsic viscosity of 1.13 dL / g.

[0394] The polyetherketoneketone produced via the process using benzoic acid as a dispersant had an initial complex viscosity of 5380 Pa.s.

[0395] The polyetherketoneketone according to Example 4 had an initial complex viscosity of 1320 Pa·s.

[0396] This shows that the use of dispersants in the process for making polyetherketoneketones and / or the presence of their residues in the polyetherketoneketones made therefrom have adverse consequences for the thermal stability of the polymer. In particular, this shows a rapid increase in viscosity when the polymer is melted.

Claims

1. A process for producing polyetherketoneketone, comprising: - contacting an aromatic ether or a mixture of aromatic ethers with an acid chloride or a mixture of acid chlorides and a Lewis acid in all or a portion of a reaction solvent to form a reaction mixture, the aromatic ether or the mixture of aromatic ethers comprising at least 50 mol % of 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene, or a mixture thereof, relative to the total moles of the aromatic ether, 1,3-bis(4-phenoxybenzoyl)benzene and / or 1,4-bis(4-phenoxybenzoyl)benzene is substantially insoluble in the reaction solvent at the end of the contacting step; and, - polymerizing the reaction mixture, the polymerization being carried out at least partially at a temperature Tp greater than or equal to 50° C.; The process is characterized in that it comprises a step of gradually heating the reaction mixture until an acceleration of the polymerization reaction is achieved, The step of gradually heating is performed at an average heating rate selected from the range of from 0.65° C. / min to 2.5° C. / min; One or more chain limiters are optionally added during the process.

2. The process according to claim 1, wherein the acyl chloride is selected from the group consisting of terephthaloyl chloride, isophthaloyl chloride, phthaloyl chloride, phosgene, adipoyl chloride, tetrabromophthaloyl chloride, and compounds of the following formula: in: 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) q -O-, -S-, -(CF2) q -、-(CH2) q -, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20.

3. The process according to any one of claims 1 and 2, wherein the mixture of aromatic ethers used, in addition to the aromatic ether selected from 1,3-bis(4-phenoxybenzoyl)benzene, 1,4-bis(4-phenoxybenzoyl)benzene, or a mixture thereof, further comprises at least one other aromatic ether selected from the following: diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone, The product of the reaction of two molecules, especially two identical molecules, with an acyl chloride molecule selected from the group consisting of diphenyl ether, 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, 3,4'-diphenoxybenzophenone, and the acyl chloride molecule selected from the group consisting of phthaloyl chloride, phosgene, adipoyl chloride, and compounds of the following formula: in: 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) q -O-, -S-, -(CF2) q -、-(CH2) q -, or C-(CH3)2-; and wherein q is an integer ranging from 1 to 20; and the product of an electrophilic Friedel-Crafts substitution reaction of two molecules, especially the same two molecules, selected from 4,4'-diphenoxybenzophenone, 3,3'-diphenoxybenzophenone, and 3,4'-diphenoxybenzophenone, with an acyl chloride molecule selected from terephthaloyl chloride and isophthaloyl chloride.

4. The process according to any one of claims 1 to 3, wherein the reaction solvent is selected from: o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, o-difluorobenzene, and mixtures thereof.

5. The process according to any one of claims 1 to 4, wherein 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, iron chloride, tin chloride, titanium tetrachloride and molybdenum pentachloride, and mixtures thereof.

6. The process according to any one of claims 1 to 5, wherein at least one chain limiter is added during the process, The chain limiter is a nucleophilic chain limiter selected from compounds having the following chemical formula: in: X1 represents a covalent bond, -O-, or -S-; and X2 represents C6H5CO or C6H5SO2; and in: X3 represents a halogen atom, an alkyl group containing from 1 to 10 carbon atoms, or an alkoxy group; Or the chain limiter is an electrophilic chain limiter selected from compounds having the following formula: in: X4 represents: a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, a nitro group, a C6H5CO group or a C6H5SO2 group; or a compound having the formula: in: Xn represents n groups, n is an integer selected from between 2 and 5, each group being independently selected from: a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO or a C6H5SO2 group.

7. Process according to any one of claims 1 to 6, wherein the molar ratio of aromatic ether which has been introduced into the reaction mixture at the end of the polymerization relative to the reaction solvent is: from 0.005 to 0.030, preferentially: from 0.008 to 0.025 and very preferably: from 0.010 to 0.

022.

8. Process according to any one of claims 1 to 7, wherein an excess of aromatic ether is reacted with the acid chloride, wherein the molar ratio of aromatic ether introduced into the reaction mixture at the end of the contacting step relative to the acid chloride is preferentially from 1.001 to 1.

1.

9. The process according to any one of claims 1 to 8, wherein the molar ratio of Lewis acid to aromatic ether introduced into the reaction mixture at the end of the contacting step is: from 5.0 to 7.0, preferentially: from 5.5 to 6.

5.

10. The process according to any one of claims 1 to 9, wherein the reaction mixture is maintained during the step of contacting at a temperature T0 of less than or equal to 5°C, preferentially less than or equal to 0°C, and more preferably less than or equal to -5°C.

11. Process according to any one of claims 1 to 10, wherein the temperature Tp is less than or equal to 120°C, preferably less than or equal to 100°C.

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

13. The process 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 the group consisting of 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, an additional aromatic ether selected from the group consisting of diphenyl ether, 4,4'-diphenoxybenzophenone, or a mixture of diphenyl ether and 4,4'-diphenoxybenzophenone; The mixture of aromatic ethers comprises up to 20 mol %, preferentially up to 10 mol % and more preferably up to 5 mol % of said further aromatic ether, relative to the total moles of aromatic ethers.

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

15. The process according to any one of claims 1 to 14, wherein the acid chloride is selected from isophthaloyl chloride, terephthaloyl chloride, and mixtures thereof.

16. The process of any one of claims 1 to 15, wherein the Lewis acid is aluminum trichloride.

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

18. The process according to any one of claims 1 to 17, wherein a chain limiter is added during the process, The chain limiter is benzoyl chloride, p-fluorobenzoyl chloride, 3,5-difluorobenzoyl chloride, or a mixture thereof.

19. The process according to any one of claims 1 to 18, wherein the stepwise heating step is carried out with an average heating rate ranging from 0.70°C / min to 2.2°C / min, preferentially with an average heating rate ranging from 0.75°C / min to 2.0°C / min, and more preferably with an average heating rate ranging from 0.8°C / min to 1.8°C / min.

20. Process 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, said mass fraction being calculated by dividing the weight of reaction solvent introduced at the end of the contacting step by the total weight of reaction solvent introduced at the end of the polymerization.

21. The process according to any one of claims 1 to 20, wherein The polyetherketoneketone produced is composed of repeating units of formula (I) and formula (II), the ratio of the unit of formula (II) to the unit of formula (I) is from 55:45 to 95:5, The units of formula (I) have the following chemical formula: And the unit of formula (II) has the following chemical formula:

22. A polyetherketoneketone having chain ends controlled by a chain limiter, which satisfies the following inequality: IV*FDC (LDC) ≥LIM; (Equation 1) in: IV represents the intrinsic viscosity of the polymer, expressed in dL / g, which is measured according to the standard ISO 307-2009 applicable to PEKK; FDC (LDC) represents the molar concentration of groups derived from the chain limiter relative to the total weight of the polymer, expressed in microequivalents of chain limiter per gram of polymer; LIM is a number that is at least 40.

23. The polyetherketoneketone according to claim 22, wherein the chain limiter is a nucleophilic chain limiter selected from compounds having the following chemical formula: in: X1 represents a covalent bond, -O-, or -S-; and X2 represents C6H5CO or C6H5SO2; and in: X3 represents a halogen atom, an alkyl group containing from 1 to 10 carbon atoms, or an alkoxy group; Alternatively, the chain limiter is an electrophilic chain limiter selected from compounds having the formula: in: X4 represents: a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO group or a C6H5SO2 group; or a compound having the formula: in: Xn represents n groups, n is an integer selected from between 2 and 5, each group being independently selected from: a halogen atom, an alkyl group or an alkoxy group containing from 1 to 10 carbon atoms, or a nitro group, a C6H5CO or a C6H5SO2 group.

24. The polyetherketoneketone according to any one of claims 22 and 23, wherein the chain limiter is benzoyl chloride, p-fluorobenzoyl chloride, 3,5-difluorobenzoyl chloride, or a mixture thereof.

25. The polyetherketoneketone according to any one of claims 22 to 24, having an intrinsic viscosity greater than or equal to 0.4 dL / g, preferably greater than or equal to 0.5 dL / g, preferably greater than or equal to 0.6 dL / g, and more preferably greater than or equal to 0.7 dL / g; and / or having an intrinsic viscosity less than or equal to 2 dL / g and preferably less than or equal to 1.5 dL / g; The intrinsic viscosity is measured according to standard ISO 307-2009 using a viscometer such as an Ubbelohde suspension grade viscometer at 25°C in a 96.00% sulfuric acid solution at a concentration of 0.0005 g / mL.

26. The polyetherketoneketone of claim 25 having an intrinsic viscosity ranging from 0.98 dL / g to 1.4 dL / g.

27. The polyetherketoneketone according to any one of claims 22 to 26, which consists of repeating units of formula (I) and formula (II), the ratio of the units of formula (II) relative to the units of formula (I) being from 55:45 to 95:5, The units of formula (I) have the following chemical formula: And the unit of formula (II) has the following chemical formula:

28. The polyetherketoneketone according to any one of claims 22 to 27, which does not contain any dispersant.

29. The polyetherketoneketone powder according to any one of claims 22 to 28, for which the mass proportion of particles having a size strictly greater than 630 microns is less than or equal to 25%, preferentially less than or equal to 15%, and more preferentially less than or equal to 10%, obtained by screening using a sieve with a mesh size equal to 630 microns.

30. Polyetherketoneketone powder according to any one of claims 22 to 29, for which the mass proportion of particles having a size strictly greater than 450 microns is less than or equal to 75%, preferentially less than or equal to 50%, more preferentially less than or equal to 25%, even more preferentially less than or equal to 20%, and most preferably less than or equal to 16%, which is obtained by screening using a sieve with a mesh size equal to 450 microns.

31. The polyetherketoneketone powder according to any one of claims 22 to 30, for which the tap density is greater than or equal to 200 kg / m 3 , as measured in the Examples.

32. The polyetherketoneketone powder according to any one of claims 22 to 31, for which the BET specific surface area is less than or equal to 4 m 2 / g.

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