Process for the preparation of porous powders formed of copolyesteramides and powders thus obtained

Abstract

For the preparation of powders formed of copolyesteramides by anionic polymerization, at least one lactam and at least one lactone are copolymerized in solution in a solvent in the presence of a catalyst and of an activator, the solvent being a solvent of the lactam and the powders being insoluble in the solvent. Preferably at least two lactams and at least one lactone are copolymerized, and the copolymerization is preferably carried out in the presence of a finely divided organic or inorganic filler. The copolymerization is preferably carried out in the presence of an N,N′-alkylenebisamide, such as ethylenebisstearamide (EBS) disclosed in EP 192 515, or generally amides of formula R1-NH—CO—R2, in which R1 can be replaced by an R3-CO—NH— or R3-O— radical and in which R1, R2 and R3 denote an aryl, alkyl or cycloalkyl radical. Powders are obtained formed of copolyesteramides comprising, in moles (the total being 100%): 1 to 98% of a lactam, 1 to 98% of another lactam, 1 to 98% of a lactone, which have a diameter of between 1 μm and 200 μm and a specific surface of between 1 and 25 m2/g.

Dependencies are inferred from the claim text.