METHOD FOR THE RECOVERY OF COMPOUNDS DERIVING FROM THE

SYNTHESIS OF ARYL ETHER KETONES

TECHNICAL FIELD

The present invention relates to a method for the recovery of compounds from compositions that derive from the synthesis of aryl ether ketones and remain after recovery and/or purification of said aryl etherketones.

TECHNICAL BACKGROUND

Aryl ether ketones (AEK), notably poly aryl ether ketone polymers (PAEK) have a number of properties which make them useful for applications involving exposure to high temperature or to high mechanical or chemical stress. They are, for instance, useful in the aerospace industry, in off-shore drilling and in medical devices.

At the end of the manufacture process of the AEKs, once the AEKs are recovered the residual solvents, the unconverted reactants, the reaction by-products along with remaining unrecovered particles of the AEK compounds often form a viscous slurry which is difficult to handle and is prone to plugging the equipment due to the deposition of solids. Furthermore, not only the slurry is classified as hazardous waste, but also the recovery and recycling of the reaction solvents and/or reactants from the slurry is considered to be a difficult procedure which requires high costs.

Conventional means for handling such slurries involves the use of a large quantity of solvent during the manufacture process or the addition of diluent fluids in order to reduce the viscosity or increase the dilution of the slurry. However, this results in larger volumes and costs associated with the handling and disposal of hazardous waste.

Document JP S55-15604 discloses a device for removing volatile substances from a high viscosity composition, and more particularly for removing residual tobacco and remaining solvents from a thermoplastic resin, by using a thin-film evaporator.

Document JP S53-1 1 1394 discloses a method for removing remaining monomers from a polyamide resin, by using a thin-film evaporator.

Document US 201 1/0201775 discloses a method for removing impurities found in diphenyl sulfone, the solvent used for the synthesis of poly aryl ether ketone polymers and more specifically for the synthesis of poly ether ketone and poly ether ether ketone polymers, in order to improve the polymer properties. One of the approaches employed makes use of a thin-film evaporator.

Document US 2003/01 1 1 186 discloses a method for removing all solvent from a solution containing a polyphenylene ether polymer resin, the method employing the use of a wiped thin film evaporator.

There is still a need for a method for recovering residual solvents and reactants from residues related to the synthesis of aryl ether ketones in a simple and cost-effective way, in order to reduce raw material costs, while at the same time minimizing the volume and the hazardous nature of the waste, notably by reducing the organochlorine content below 1000 ppm.

SUMMARY OF THE INVENTION

It is a first object of the invention to provide a method for treating a shear thinning residue composition deriving from the synthesis of an aryl ether ketone, said residue composition comprising a liquid fraction and solid residues, the method comprising the steps of:

(i) passing said shear-thinning residue composition through a shear generating evaporating device, between a rotating part and a stationary part; and

(ii) recovering a condensed liquid fraction and separately recovering concentrated solid residues.

According to some embodiments, a shear rate is applied to the shear-thinning residue composition by the shear-generating evaporating device, the shear rate being equal to or greater than 10 s-1 , preferably equal to or greater than 250 s-1 , more preferably equal to or greater than 1000 s-1 , and even more preferably equal to or greater than 2500 S'1 .

According to some embodiments, the shear-thinning residue composition has a zero shear viscosity at 25°C from 1 to 10000 Pa.s, preferably from 1 to 1000 Pa.s, more preferably from 1 to 100 Pa.s and even more preferably from 5 to 50 Pa.s.

According to some embodiments, the minimum distance between the rotating part and the stationary part of the shear-generating evaporating device is from 0.03 to 5 mm, and preferably from 0.05 to 3.5 mm.

According to some embodiments, the aryl ether ketone is chosen from 1 ,4-bis(4-phenoxybenzoyl)benzene and/or a poly ether ketone ketone polymer.

According to some embodiments, the liquid fraction of the shear-thinning residue composition comprises at least one residual solvent and/or at least one residual reactant.

According to some embodiments, the residual solvent is chosen from carbon disulfide, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene, 1 ,2,4-trichlorobenzene, 1 ,2,3-trichlorobenzene, ortho-difluorobenzene, 1 ,1 -dichloroethane, 1 ,2-dichloroethane, 1 ,1 ,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene and mixtures thereof; and wherein the residual solvent is preferably ortho-dichlorobenzene.

According to some embodiments, the residual reactant is diphenyl ether.

According to some embodiments, the solid residues comprise aryl ether ketone particles such as 1 ,4-bis(4-phenoxybenzoyl)benzene and/or a poly ether ketone ketone polymer, and/or reaction by-products resulting from an incomplete conversion to the reaction products and/or by-products resulting from a side reaction.

According to some embodiments, the shear-generating evaporating device ischosen from a horizontal thin-film evaporator, a vertical thin-film evaporator, a horizontal wiped-film evaporator, a vertical wiped-film evaporator, a scraped-surface heat exchanger, a single-screw devolatilizing extruder, and a twin-screw devolatilizing extruder.

According to some embodiments, an appropriate amount of a displacing compound such as a wax or a fat is added to the shear-thinning residue composition prior to, during, or after the introduction into the evaporating device. According to some embodiments, the method described above is carried out as a batch process, or a semi-batch process, or a continuous process.

According to some embodiments, the shear-thinning residue composition has a solids concentration before step (i) from 5 to 25 wt.%, and preferably from 15 to 20 wt.%.

According to some embodiments, the shear-thinning residue composition is brought to a temperature in the shear-generating evaporating device equal to or greater than 160°C, preferably equal to or greater than 170°C, and more preferably equal to or greater than 175°C.

According to some embodiments, the concentrated solid residue contain below 1000 ppm of organochlorine and/or have a flashpoint of above 93°C.

According to some embodiments, the method further comprises a subsequent step of:

(iii) using the concentrated solid residues as a fuel source.

According to some embodiments, the condensed liquid fraction recovered in step (ii) is recycled in the synthesis of the aryl ether ketone, and preferably in the synthesis of 1 ,4-bis(4-phenoxybenzoyl)benzene and/or the synthesis of a poly ether ketone ketone polymer.

According to some embodiments, the condensed liquid fraction recovered in step (ii) comprises at least one residual solvent and at least one residual reactant which are separated prior to recycling and are recycled separately.

According to some embodiments, from 65 to 99 wt.% and more preferably from 75 to 97 wt.% of the liquid fraction of the shear-thinning residue composition is recovered in the recovered condensed liquid fraction.

According to some embodiments, the method described above comprises a preliminary step of providing the shear-thinning residue composition, said preliminary step comprising recovering a mother liquor from the synthesis of an aryl ether ketone, distilling said mother liquor and recovering the shear-thinning residue composition as a distillation residue.

A second object of the invention is to provide a method for manufacturing an aryl ether ketone, comprising:

reacting a reactant A with a reactant B in a reaction solvent, so as to obtain a product mixture comprising the aryl ether ketone, wherein reactant A is a difunctional aromatic molecule containing one or more oxygen atoms, wherein reactant B is a difunctional aromatic molecule containing one or more halogen atoms;

subjecting the product mixture to a solid/liquid separation so as to recover a purified aryl ether ketone and to separately recover a mother liquor; and either:

o subjecting the mother liquor to the method described above in the first object of the invention, said mother liquor forming part or all of the shear-thinning residue composition; or

o distilling said mother liquor, recovering a shear-thinning residue composition as a distillation residue, and subjecting said recovered shear-thinning residue composition to the method described above in the first object of the invention.

According to some embodiments, the aryl ether ketone is 1 ,4-bis(4-phenoxybenzoyl)benzene, reactant A is terephthaloyl chloride and reactant B is diphenyl ether.

According to some embodiments, the aryl ether ketone is a poly ether ketone ketone polymer, reactant A is a difunctional aromatic acyl chloride and reactant B is

1.4-bis(4-phenoxybenzoyl)benzene.

According to some embodiments, the method comprises a preliminary stage of manufacturing 1 ,4-bis(4-phenoxybenzoyl)benzene according to a method described above, and wherein, optionally, the shear-thinning residue composition deriving from the synthesis of 1 ,4-bis(4-phenoxybenzoyl)benzene is at least partially mixed with the shear-thinning residue composition deriving from the synthesis of the poly ether ketone ketone polymer prior to subjecting them to the method for treating a shear-thinning composition as described above.

According to some embodiments, the reaction solvent is chosen from carbon disulfide, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene,

1.2.4-trichlorobenzene, 1 ,2,3-trichlorobenzene, ortho-difluorobenzene, 1 ,1 -dichloroethane, 1 ,2-dichloroethane, 1 ,1 ,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene and mixtures thereof; and wherein the reaction solvent is preferably ortho-dichlorobenzene.

According to some embodiments, the solid/liquid separation step comprises a filtration step, preferably a centrifugal filtration step.

The present invention provides a method for recovering residual solvents and/or reactants from residues related to the synthesis of aryl ether ketones in a simple and cost-effective way, in order to reduce raw material costs, while at the same time minimizing the volume and the hazardous nature of the waste, notably by reducing the organochlorine content below 1000??? ppm.

Preferably, the solid waste obtained contains less than 500, 400, 300, 200, 100, 50 ppm of organochlorine compounds and/or has a flashpoint above 93°C. In particular, it is preferred that the solid waste is non-hazardous, and may thus be disposed of more easily or used as a fuel.

The invention relies on the unexpected realization that compositions deriving from the synthesis of aryl ether ketones and containing residual solvents, reactants, products and/or by-products, although highly viscous, may have shear-thinning properties. This makes them suitable for being treated in a shear-generating evaporating device such as a thin film evaporator, a devolatilizing extruder, or the like.

The invention thus advantageously comprises passing such a shear-thinning composition (viscous slurry) comprising a liquid fraction and solid residues through an evaporating device under shear, to reduce the viscosity of the slurry, which improves heat transfer. In addition, the mixture of residual reactants, and (non volatile) by-products present in the composition, can affect the melting temperatures of the residual reactants. In fact, the presence of the byproducts makes it easier to melt some or all of the (solid) reactants, so after evaporation, they can be handled in molten form, instead of as solid. Therefore, evaporated residual solvents and residual reactants can be recovered on the one hand, while a concentrated residue can be collected on the other hand, allowed to be cooled and solidified before being safely disposed of.

This is surprising, as compositions having a high solids content would be rather expected to be highly viscous and hinder heat transfer, and remaining solids and non volatile material would be expected to bake onto the evaporator surfaces and not be dischargeable from the evaporator.

Prior to, during, or after the introduction of the shear-thinning residue composition into the evaporating device, an appropriate quantity of a displacing compound or displacer can be added.

The displacing compound or displacer is a compound that forms a non-volatile, stable and inert liquid at the operating temperature of the evaporator. Such compounds may notably be chosen among waxes and fats, such as hydrogenated vegetable oils, notably bean oil, animal fats, paraffins, stearates, or similar. The presence of such compounds assists residual solvent and reactants recovery by displacing said solvent and reactants during evaporation.

The displacer is preferably less expensive than the ODCB. The added displacer displaces the residue solvent and thereby further improves the recovery rate. Accordingly, the waste thus obtained contains less residual solvent and preferably meets the regulations for non-hazardous waste, which facilitates its handling and further use.

In some cases, such as where the displacer is liquid at room temperature, the waste obtained may not be strictly solid but in form of a dispersion.

The appropriate quantity of displacing compound may depend notably on the quantity and the nature of the solvent residue. Such quantity may notably be between 0.01 to 70%, 0.1 to 60%, 1 to 50%, 10 to 40% or 20 to 30% by weight with respect to the total weight of the shear thinning composition,

The evaporator is advantageously operated at a sufficiently high shear rate and temperature to keep the un-evaporated portion in an at least partially liquefied (molten) state. The invention has the advantages of reducing raw material costs for the AEK production process, minimizing the volume and reducing the hazardous nature of wastes, and/or simplifying the handling and reducing the disposal costs of the residues.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the viscosity (in Pa.s) of a residue composition deriving from the synthesis of 1 ,4-bis(4-phenoxybenzoyl)benzene as a function of the shear rate (in S 1) at 25 °C (circles), 51 °C (triangles) and 83°C ( crosses).

Figure 2 shows the viscosity (in Pa.s) of concentrated solid residues recovered after evaporating a residue composition deriving from the synthesis of 1 ,4-bis(4-phenoxybenzoyl)benzene as a function of the shear rate (in S 1 ) at 150°C (triangle), 160°C (squares) and at 175°C (circles).

Figure 3 shows schematically the process for the recovery of solvent and reactants from AEK process residues (Fig.3A) and an embodiment of the invention (Fig.3B).

DESCRIPTION OF EMBODIMENTS

The invention will now be described in more detail without limitation in the following description.

The term“deriving from” (the synthesis, a slurry, a phase) is used to indicate the origin of a component/product and means“originating from”.

AEK compounds

By“aryl ether ketone” or“AEK’, is meant a compound comprising patterns of formula (-Ar-X-) and of formula (-Ar’-Y-), wherein:

- Ar and Ar’ each designate an aromatic divalent radical;

- Ar and Ar’ can preferably be chosen from 1 ,3-phenylene, 1 ,4-phenylene, 4,4'-biphenylene, 1 ,4-naphthylene, 1 ,5-naphthylene and 2,6-naphthylene, possibly substituted;

- X designates an electro-attracting group which can be preferably chosen from a carbonyl group and a sulfonyl group;

- Y designates a group chosen from an oxygen atom, a sulfur atom, an alkylene group, such as for example -CFi2- or isopropylidene.

The AEK comprises at least one pattern of formula (-Ar-X-), at least one pattern of formula (-Ar’-Y-) and preferably at least three of these patterns in total. Preferably, the AEK comprises at least two patterns of formula (-Ar-X-) and at least two patterns of formula (-Ar’-Y-).

In some embodiments, at least 50 mol.%, preferably at least 70 mol.% and more preferably at least 80 mol.% of groups X within the AEK represent a carbonyl group. According to some embodiments, all groups X within the AEK represent a carbonyl group.

In some embodiments, at least 50 mol.%, preferably at least 70 mol.% and more preferably at least 80 mol.% of groups Y within the AEK represent an oxygen atom. According to some embodiments, all groups Y within the AEK represent an oxygen atom.

According to some embodiments, the AEK is a compound comprising, or preferably consisting of patterns of the formula (-Ar-CO-), patterns of the formula (-Ar’-O-), as well as end groups preferably selected from H or an aromatic group (more preferably a phenyl group), the groups Ar and Ar’ being as defined above.

According to some embodiments, the AEK is a compound comprising or preferably consisting of: fewer than 15 patterns of the formula (-Ar-CO-) and/or patterns of the formula (-Ar’-O-), preferably fewer than 10 patterns, more preferably fewer than 7 patterns and even more preferably fewer than 5 patterns of the formula (-Ar-CO-) and/or patterns of the formula (-Ar’-O-); as well as end groups preferably selected from H or an aromatic group (more preferably a phenyl group).

According to some embodiments, the AEK is a compound having the formula (Ari-0-Ar2-C0-Ar3-C0-Ar4-0-Ar5), wherein each of Ar2, Ar3 and Ar4 independently represent an aromatic divalent radical, preferably a phenylene, and wherein An and Ar5 represent an aromatic monovalent radical preferably a phenyl group.

The bonds on either side of each radical Ar2, Ar3, and Ar4 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the AEK is 1 ,4-bis(4-phenoxybenzoyl)benzene.

According to other embodiments, the AEK is a poly aryl ether ketone (PAEK).

Thus, according to some embodiments, the PAEK is a polymer comprising, or preferably consisting of patterns of the formula (-Ar-CO-), patterns of the formula (-Ar’-O-), as well as end groups preferably selected from H or an aromatic group (more preferably a phenyl group), the groups Ar and Ar’ being as defined above.

According to some embodiments, the PAEK is a poly ether ketone ketone (PEKK), comprising a succession of repeated patterns of the type -(An-0-Ar2-C0-Ar3-CO)n-, wherein each of An , Ar2 and Ar3 independently represent an aromatic divalent radical, preferably a phenylene.

In this formula, like in the following formulas, n represents an integer. In some embodiments, n is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

The bonds on either side of each radical An , Ar2 and Ar3 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the PEKK comprises a succession of repeated patterns of the following formula (I A) and/or the following formula (IB):

The patterns of formula (IA) derive from isophthalic acid (or patterns I), while patterns of formula (IB) derive from terephthalic acid (or patterns T).

According to some embodiments, the mass proportion of patterns T in relation to the totality of patterns T and I can vary from 0 to 5 %; or from 5 to 10 %; or from 10 to 15 %; or from 15 to 20 %; or from 20 to 25 %; or from 25 to 30 %; or from 30 to 35 %; or from 35 to 40 %; or from 40 to 45 %; or from 45 to 50 %; or from 50 to 55 %; or from 55 to 60 %; or from 60 to 65 %; or from 65 to 70 %; or from 70 to 75 %; or from 75 to 80 %; or from 80 to 85 %; or from 85 to 90 %; or from 90 to 95 %; or from 95 to 100 %.

A range from 35 to 100%, notably from 55 to 85 % and even more specifically from 60 to 80 %, is particularly appropriate. In all ranges mentioned herein, the terminal values are included unless otherwise stated.

According to some embodiments, the PAEK is a poly ether ether ketone (PEEK), comprising a succession of repeated patterns of the type -(An-0-Ar2-0-Ar3-CO)n-, wherein each of An , Ar2 and Ar3 independently represent an aromatic divalent radical, preferably a phenylene. In some embodiments, n is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

The bonds on either side of each radical An , Ar2 and Ar3 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the PEEK comprises a succession of repeated patterns of formula (II):

and/or a succession of repeated patterns of formula (III):

and/or a succession of repeated patterns of formula (IV):

and/or a succession of repeated patterns of formula (V):

(V)
According to some embodiments, the PAEK is a poly ether ketone (PEK), comprising a succession of repeated patterns of the type -(An-0-Ar2-CO)n-, wherein each of An and Ar2 independently represent an aromatic divalent radical, preferably a phenylene. In some embodiments, n is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

The bonds on either side of each radical An and Ar2 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the PEK comprises a succession of repeated patterns of formula (VI):

According to some embodiments, the PEK comprises a succession of repeated patterns of formula (VII):

In this formula, as for the following formulas, x and y represent integers. In some embodiments, each of x and y is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

According to some embodiments, the PEK comprises a succession of repeated patterns of formula (VIII):

According to some embodiments, the PAEK is a poly ether ether ketone ketone (PEEKK), comprising a succession of repeated patterns of the type -(An-0-Ar2-0-Ar3-CO-Ar4-CO)n-, wherein each of An , Ar2, Ar3 and Ar4 independently represent an aromatic divalent radical, preferably a phenylene. In some embodiments, each of x and y is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

The bonds on either side of each radical An , Ar2, Ar3 and Ar4 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the PEEKK comprises a succession of repeated patterns of formula (IX):

According to some embodiments, the PAEK is a poly ether ether ether ketone (PEEEK), comprising a succession of repeated patterns of the type -(An-0-Ar2-0-Ar3-0-Ar4-C0)n-, wherein each of An , Ar2, Ar3 and Ar4 independently represent an aromatic divalent radical, preferably a phenylene. In some embodiments, n is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

The bonds on either side of each radical An , Ar2, Ar3 and Ar4 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the PEEEK comprises a succession of repeated patterns of formula (X):

According to some embodiments, the PAEK is a poly ether ketone ether ketone ketone (PEKEKK), comprising a succession of repeated patterns of the type -(An-O-Ar2-C0-Ar3-0-Ar4-C0-Ar5-C0)n-, wherein each of An , Ar2, Ar3, Ar4 and Ar5 independently represent an aromatic divalent radical, preferably a phenylene. In some embodiments, n is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

The bonds on either side of each radical An , Ar2, Ar3, Ar4 and Ar5 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the PAEK is a poly ether ether ketone ether ketone (PEEKEK), comprising a succession of repeated patterns of the type -(An-O-Ar2-0-Ar3-C0-Ar4-0-Ar5-C0)n-, wherein each of An , Ar2, Ar3, Ar4 and Ar5 independently represent an aromatic divalent radical, preferably a phenylene. In some embodiments, n is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

The bonds on either side of each radical An , Ar2, Ar3, Ar4 and Ar5 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the PAEK is according to the general formula described above, wherein some of the radicals Ar and/or Ar’ represent a divalent radical deriving from diphenyl or biphenol.

According to some embodiments, the PAEK is a poly ether diphenyl ether ketone (PEDEK), comprising a succession of repeated patterns of the type -(An-O-D-0-Ar2-C0)n-, wherein each of An and Ar2 independently represent an aromatic divalent radical, preferably a phenylene, and D represents a divalent radical deriving from diphenyl. In some embodiments, n is at least 2, or at least 10, or at least 50, or at least 100, or at least 500, or at least 1000, up to, for example, n of 1 ,000,000.

The bonds on either side of each radical An and Ar2 can be of the type para, or meta, or ortho (preferably para or meta).

According to some embodiments, the PEDEK comprises a succession of repeated patterns of formula (XI):

According to some embodiments, the PAEK comprises two or more of those repeated patterns. According to a preferred embodiment, the PAEK is a PEEK-PEDEK copolymer.

1 ,4-bis(4-phenoxybenzoyl)benzene and a PEKK polymer are particularly preferred as the AEK compounds.

Manufacture of 1 ,4-bis(4-phenoxybenzoyl)benzene

1 ,4-bis(4-phenoxybenzoyl)benzene is the compound of formula (XII):

o

It may be made by reacting terephthaloyl chloride of formula (XIII):

(XIII)
with diphenyl ether of formula (XIV):

(XIV)
in a solvent (the reaction solvent), and preferably in the presence of a Lewis acid, acting as a Friedel-Crafts catalyst.

The reaction results in the production of the compound of formula (XII) which is predominantly in the form of a complex with the Lewis acid.

During the reaction, 4-(4-phenoxybenzoyl)benzoic acid of formula (XV) can be produced to some extent:

The corresponding 4-(4-phenoxybenzoyl)benzoic acid ester can also be formed as a by-product during manufacturing.

The other main impurities produced by the reaction are xanthydrol moiety-containing molecules.

The reaction solvent is preferably a non-protic solvent.

A protic solvent is a solvent containing at least one hydrogen atom bound to an oxygen or nitrogen atom, and which is therefore able to donate protons to reagents.

A non-protic solvent is a solvent which is not a protic solvent.

The non-protic solvent used herein can in particular be selected from carbon disulfide, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene, 1 ,2,4-trichlorobenzene, 1 ,2,3-trichlorobenzene, ortho-difluorobenzene, 1 ,1 -dichloroethane, 1 ,2-dichloroethane, 1 ,1 ,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene and mixtures thereof.

Ortho-dichlorobenzene is the most preferred solvent.

Lewis acids which may be used include, for example, aluminum trichloride, aluminum tribromide, antimony pentachloride, antimony pentafluoride, indium trichloride, gallium trichloride, boron trichloride, boron trifluoride, zinc chloride, ferric chloride, stannic chloride, titanium tetrachloride, and molybdenum pentachloride. Aluminum trichloride, boron trichloride, aluminum tribromide, titanium tetrachloride, antimony pentachloride, ferric chloride, gallium trichloride, and molybdenum pentachloride are preferred. Aluminum trichloride is particularly preferred.

The reaction between the compounds of formulas (XIII) and (XIV) to make the compound of formula (XII) is performed in a reactor. The reactor can be for instance a glass reactor, a glass-lined reactor or a stainless-steel reactor.

According to some variations, the materials introduced into the reactor in the method of embodiments of the invention consist essentially, or consist, of the compounds of formulas (XIII) and (XIV), the reaction solvent and the Lewis acid.

According to embodiments of the invention, an initial reactant mixture comprising (and preferably consisting of) terephthaloyl chloride and diphenyl ether in the reaction solvent is provided. The reactant mixture can be made by mixing the three components together, in any order. By way of example, the solvent can be introduced first in the reactor, and then the two reactants can be added to the reactor.

CLAIMS

1. A method for treating a shear-thinning residue composition deriving from the synthesis of a aryl ether ketone, said residue composition comprising a liquid fraction and solid residues, the method comprising the steps of:

(i) passing said shear-thinning residue composition through a shear generating evaporating device, between a rotating part and a stationary part; and

(ii) recovering a condensed liquid fraction and separately recovering concentrated solid residues.

2. The method according to claim 1 , wherein a shear rate is applied to the shear-thinning residue composition by the shear-generating evaporating device, the shear rate being equal to or greater than 10 s 1 , preferably equal to or greater than 250 s-1 , more preferably equal to or greater than 1000 S 1 , and even more preferably equal to or greater than 2500 s-1.

3. The method according to any one of claims 1 or 2, wherein the shear-thinning residue composition has a zero shear viscosity at 25°C from 1 to 10000 Pa.s, preferably from 1 to 1000 Pa.s, more preferably from 1 to 100 Pa.s and even more preferably from 5 to 50 Pa.s.

4. The method according to any one of claims 1 to 3, wherein the minimum distance between the rotating part and the stationary part of the shear generating evaporating device is from 0.03 to 5 mm, and preferably from 0.05 to 3.5 mm.

5. The method according to any one of claims 1 to 4, wherein the aryl ether ketone is chosen from 1 ,4-bis(4-phenoxybenzoyl)benzene and/or a poly ether ketone ketone polymer.

6. The method according to any one of claims 1 to 5, wherein the liquid fraction of the shear-thinning residue composition comprises at least one residual solvent and/or at least one residual reactant.

7. The method according to claim 6, wherein the liquid fraction of the shear-thinning residue composition comprises at least one residual solvent, wherein the residual solvent is chosen from carbon disulfide, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene, 1 ,2,4-trichlorobenzene, 1 ,2,3-trichlorobenzene, ortho-difluorobenzene, 1 , 1 -dichloroethane, 1 ,2-dichloroethane, 1 , 1 ,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene and mixtures thereof; and wherein the residual solvent is preferably ortho dichlorobenzene.

8. The method according to claim 6 or 7, wherein the liquid fraction of the shear-thinning residue composition comprises at least one residual reactant, wherein the residual reactant is diphenyl ether.

9. The method according to any one of claims 1 to 8, wherein the solid residues comprise aryl ether ketone particles such as 1 ,4-bis(4- phenoxybenzoyl)benzene and/or a poly ether ketone ketone polymer, and/or reaction by-products resulting from an incomplete conversion to the reaction products and/or by-products resulting from a side reaction.

10. The method according to any one of claims 1 to 9, wherein the shear-generating evaporating device is chosen from a horizontal thin- film evaporator, a vertical thin-film evaporator, a horizontal wiped-film evaporator, a vertical wiped-film evaporator, a scraped-surface heat exchanger, a single-screw devolatilizing extruder, and a twin-screw devolatilizing extruder.

11. The method according to any one of claims 1 to 10, wherein an appropriate amount of a displacing compound such as a wax or a fat is added to the shear-thinning residue composition prior to, during, or after the introduction into the evaporating device.

12. The method according to any one of claims 1 to 1 1 , wherein the method is carried out as a batch process, or a semi-batch process, or a continuous process.

13. The method according to any one of claims 1 to 12, wherein the shear-thinning residue composition has a solids concentration before step (i) from 5 to 25 wt.%, and preferably from 15 to 20 wt.%.

14. The method according to any one of claims 1 to 13, wherein during step (i) the shear-thinning residue composition is brought to a temperature equal to or greater than 160°C, preferably equal to or greater than 170°C, and more preferably equal to or greater than 175°C.

15. The method according to any one of claims 1 to 14, further comprising a subsequent step of:

(iii) using the concentrated solid residues as a fuel source.

16. The method according to any one of claims 1 to 15, wherein the condensed liquid fraction recovered in step (ii) is recycled in the synthesis of the aryl ether ketone, and preferably in the synthesis of 1 ,4- bis(4-phenoxybenzoyl)benzene and/or the synthesis of a poly ether ketone ketone polymer.

17. The method according to claim 16, wherein the condensed liquid fraction recovered in step (ii) comprises at least one residual solvent and at least one residual reactant which are separated prior to recycling and are recycled separately.

18. The method according to any one of claims 1 to 17, wherein from 65 to 99 wt.% and more preferably from 75 to 97 wt.% of the liquid fraction of the shear-thinning residue composition is recovered in the recovered condensed liquid fraction.

19. The method according to any one of claims 1 to 18, comprising a preliminary step of providing the shear-thinning residue composition, said preliminary step comprising recovering a mother liquor from the synthesis of an aryl ether ketone, distilling said mother liquor, and

recovering the shear-thinning residue composition as a distillation residue.

20. A method for manufacturing an aryl ether ketone, comprising:

- reacting a reactant A with a reactant B in a reaction solvent, so as to obtain a product mixture comprising the aryl ether ketone, wherein reactant A is a difunctional aromatic molecule containing one or more oxygen atoms, wherein reactant B is a difunctional aromatic molecule containing one or more halogen atoms;

- subjecting the product mixture to a solid/liquid separation so as to recover a purified aryl ether ketone and separately recover a mother liquor; and

- either:

o subjecting the mother liquor to a method for treating a shear thinning residue composition, said mother liquor forming part or all of the shear-thinning residue composition; or

o distilling said mother liquor, recovering a shear-thinning residue composition as a distillation residue, and subjecting said recovered shear-thinning residue composition to the method for treating a shear-thinning residue composition, wherein the method for treating a shear-thinning residue composition is the method of any one of claims 1 to 19.

21. The method of claim 20, wherein the aryl ether ketone is 1 ,4-bis(4- phenoxybenzoyljbenzene, reactant A is terephthaloyl chloride, and reactant B is diphenyl ether.

22. The method of claim 20, wherein the aryl ether ketone is a poly ether ketone ketone polymer, reactant A is a difunctional aromatic acyl chloride, and reactant B is 1 ,4-bis(4-phenoxybenzoyl)benzene.

23. The method according to claim 22, comprising a preliminary stage of manufacturing 1 ,4-bis(4-phenoxybenzoyl)benzene according to claim 20, and wherein, optionally, the shear-thinning residue composition deriving from the synthesis of 1 ,4-bis(4-phenoxybenzoyl)benzene is at least partially mixed with the shear-thinning residue composition

deriving from the synthesis of the poly ether ketone ketone polymer prior to subjecting them to the method of any one of claims 1 to 19.

24. The method according to any one of claims 20 to 23, wherein the reaction solvent is chosen from carbon disulfide, ortho-dichlorobenzene, meta-dichlorobenzene, para-dichlorobenzene, 1 ,2,4-trichlorobenzene, 1 ,2,3-trichlorobenzene, ortho-difluorobenzene, 1 ,1 -dichloroethane, 1 ,2- dichloroethane, 1 , 1 ,2,2-tetrachloroethane, tetrachloroethylene, dichloromethane, nitrobenzene and mixtures thereof; and wherein the reaction solvent is preferably ortho-dichlorobenzene.

25. The method according to any one of claims 20 to 24, wherein the solid/liquid separation step comprises a filtration step, preferably a centrifugal filtration step.