Polymeric material, manufacture and use

A process for formation of a component in a layer-wise fashion, comprising depositing and sequentially sintering a plurality of layers of a polyaryletherketone, PAEK, in the form of a powder, the powder comprising from 90 to 100% by weight of first particles, each first particle comprising from 60 to less than 100% by weight of the PAEK, and comprising one or more other ingredients at up to 40% by weight, and the powder further comprising from 0 to 10% by weight of other particles, wherein the PAEK is a copolymer comprising repeat units of formula

• and
• repeat units of formula
• wherein at least 95 mol % of the copolymer repeat units are repeat units of formula I and of formula II;
• wherein the repeat units I and II have a molar ratio I:II from 55:45 to 80:20;
• and
• wherein the PAEK has a melt viscosity, MV, from 0.35 to 0.55 kNsm−2 as measured using capillary rheometry at 400° C. at a shear rate of 1000 s−1 by extrusion through a tungsten carbide capillary die of 0.5 mm diameter and 8.0 mm length.

A process for forming a polyaryletherketone, PAEK, in the form of particles having a median diameter D50 from 20 to 120 μm, for use in a method for layer-wise formation of a component, wherein the PAEK is a copolymer comprising repeat units of formula

• and
• repeat units of formula
• wherein Ph represents a phenylene moiety;
• the process comprising:
• a) nucleophilic polycondensation of a mixture of benzene-1,4-diol and 4,4′-biphenol in a molar ratio of benzene-1,4-diol:
• 4,4′-biphenol from 55:45 to 80:20, with 4,4′-difluorobenzophenone in a reaction mixture comprising sodium carbonate and potassium carbonate in an aromatic sulfone solvent, at a reaction temperature rising to a temperature from 280° C. to 330° C.;
• b) cooling of the resulting reaction mixture and recovery of the PAEK copolymer resulting from step from the reaction mixture;
• c) forming the recovered PAEK copolymer into particles having a median diameter D50 from 20 to 120 μm;
• wherein in step a of the process:
• i the molar ratio of sodium carbonate to the mixture of benzene-1,4-diol and 4,4′-biphenol is from 0.95 to 1.15;
• ii the molar ratio of potassium carbonate to sodium carbonate is from 0.002 to 0.05;
• iii the molar ratio of the 4,4′-dihalobenzophenone to the mixture of benzene-1,4-diol and 4,4′-biphenol is from 1.01 to 1.03;
• iv the aromatic sulfone solvent is present in the reaction mixture as 0.27 to 1.02 kg/mole of the mixture of benzene-1,4-diol and 4,4′-biphenol;
• and
• v the polycondensation in step a is continued for sufficient time to ensure that the resulting PAEK recovered from step a has a melt viscosity, MV, from 0.35 to 0.55 kNsm−2 as measured using capillary rheometry at 400° C. at a shear rate of 1000 s−1 by extrusion through a tungsten carbide capillary die of 0.5 mm diameter and 8.0 mm length.