Patent ID: 8642713

Claim:
A process for the manufacture of a poly(aryletherketone) (P) comprising: a. forming a reaction medium by adding to a reactor: i. at least one α,ω difluorinated monomer (M1) and at least one α,ω dihydroxylated monomer (M2), and/or ii. at least one a monofluorinated, ω monohydroxylated monomer (M3); then b. adding to the reactor at least one salt (S1) of an alkali metal (A) other than lithium; then c. making the monomers and the salt (S1) react together, until the obtention of: a poly(aryletherketone) (P*) comprising recurring units derived from the monomers and having an intrinsic viscosity η int * superior to 0.7, as measured in methane sulfonic at 30° C. according to ASTM D2857, and as a by-product, a fluoride salt (S2) of the alkali metal (A), said salt (S2) having a solubility of more than 5·10 7 mol/kg in acetone at 25° C., wherein, at the completion of c, the ratio [ n M1 +( n M3 /2)]/[ n M2 +( n M3 /2)] is from 0.97 to 1.03, where n M1 , n M2 and n M3 are respectively the total number of moles of (M1), (M2) and (M3) which have been added to the reactor until the completion of c; then d. forming the poly(aryletherketone) (P) from the poly(aryletherketone) (P*), said poly(aryletherketone) (P) having an intrinsic viscosity η int comprised between 0.8·η int * and 1.2·η int *, by adding successively to the reactor: 1. at least one α,ω difluorinated compound (M1′), different from or identical to (M1); then 2. at least one salt (S3) able to react with the fluoride salt (S2) to form a fluoride salt (S4), said salt (S3) having a solubility of more than 5·10 −7 mol/kg in acetone at 25° C. and said fluoride salt (S4) having a solubility of at most 5·10 −7 mol/kg in acetone at 25° C.; then 3. at least one α,ω difluorinated compound (M1″), different from or identical to (M1) and (M1′); wherein, at the beginning of the addition of the salt (S 3 ), the ratio [ n M1 +n M1′ +( n M3 /2)]/[ n M2 +( n M3 /2)] is above 1.03, where n M1′ is the total number of moles of (M1′) which has been added to the reactor after the completion of c and until the beginning of the addition of the salt (S3) and wherein, at the completion of d, the ratio [ n M1 +n M1′ +n M1″ +( n M3 /2)]/[ n M2 +( n M3 /2)] is above 1.08, where n M1″ is the total number of moles of (M1″) which has been added to the reactor after the beginning of the addition of the salt (S3) and until the completion of d; then e. recovering the poly(aryletherketone) (P) from the reaction medium.