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

1. A method for manufacturing 1,4-bis(4-phenoxybenzoyl)benzene, comprising:

reacting terephthaloyl chloride with diphenyl ether in a reaction solvent and in the presence of a Lewis acid, so as to obtain a product mixture comprising a 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex;

contacting the product mixture with a protic solvent, so as to obtain a first phase containing the Lewis acid and a second phase containing 1,4-bis(4-phenoxybenzoyl)benzene;

heating at least the second phase up to a maximum temperature, followed by cooling at least the second phase down to a separation temperature; and

subjecting at least the second phase to a solid/liquid separation step at the separation temperature, so as to recover solid 1,4-bis(4-phenoxybenzoyl)benzene,

wherein the 1,4-bis(4-phenoxybenzoyl)benzene contained in the second phase is partly dissolved in the second phase at the maximum temperature.

2. The method of claim 1 , wherein the first phase and the second phase are separated before subjecting the second phase to heating and cooling down.

3. The method of claim 1 , wherein both the first phase and the second phase are subjected to heating and cooling down.

4. The method of claim 1 , wherein from 30 to 99.9 wt. %, of the 1,4-bis(4-phenoxybenzoyl)benzene contained in the second phase is dissolved in the second phase at the maximum temperature.

5. The method of claim 1 , wherein the maximum temperature is from 90 to 150° C.

6. The method of claim 1 , wherein the separation temperature is at least 20° C.

7. The method of claim 1 , wherein the second phase is cooled down at a rate of from 10 to 50° C./h.

8. The method of claim 1 , wherein the protic solvent is an aqueous solution.

9. The method of claim 1 , wherein the product mixture is poured into a vessel containing the protic solvent.

10. The method of claim 1 , wherein the solid/liquid separation step is a filtration step.

11. The method of claim 1 , comprising one or more steps of washing the recovered solid 1,4-bis(4-phenoxybenzoyl)benzene in a protic solvent and subjecting it to a further solid/liquid separation step.

12. The method of claim 11 , wherein at least one of the steps of washing the solid 1,4-bis(4-phenoxybenzoyl)benzene in a protic solvent is performed at a temperature of at least 20° C.

13. The method of claim 1 , wherein the Lewis acid is aluminum trichloride.

14. The method of claim 1 , wherein the reaction solvent is ortho-dichlorobenzene.

15. The method of claim 14 , wherein from 30 to 99.9 wt. %, of the 1,4-bis(4-phenoxybenzoyl)benzene contained in the second phase is dissolved in the second phase at the maximum temperature, wherein the maximum temperature is from 90 to 150° C., and wherein the separation temperature is from 25 to 40° C.

16. A method of making a polyether ketone ketone polymer, comprising:

manufacturing 1,4-bis(4-phenoxybenzoyl)benzene according to the method of claim 1 ; and

reacting said 1,4-bis(4-phenoxybenzoyl)benzene with at least one difunctional aromatic acyl chloride.

17. The method of claim 1 , wherein from 50 to 95 wt. %, of the 1,4-bis(4-phenoxybenzoyl)benzene contained in the second phase, is dissolved in the second phase at the maximum temperature.

18. The method of claim 1 , wherein from 60 to 90 wt. %, of the 1,4-bis(4-phenoxybenzoyl)benzene contained in the second phase, is dissolved in the second phase at the maximum temperature.