Patent ID: 8454866

Claim:
A process for the manufacture of a powder made of thermoplastic material P and comprising particles with a mean diameter of less than 1 mm, said process comprising the steps of: a. obtaining a dispersion of discrete particles of the thermoplastic material P by forming a melt blend of said thermoplastic material P with an additive A, said additive A being formed by a polymeric material comprising at least a part of its structure compatible with said thermoplastic material P and at least a part of its structure incompatible with and insoluble in said thermoplastic material P; b. cooling said blend to a temperature below the softening temperature of the thermoplastic material P; and c. treating said cooled blend in order to bring about the disintegration of the discrete particles of thermoplastic material P, wherein the concentration by weight of additive A in the blend is between 1% and 50%, and wherein the additive A is a block copolymer D comprising a thermoplastic polymer block and at least one poly(alkylene oxide) block, such that: the thermoplastic polymer block comprises a star or H macromolecular chain comprising at least one polyfunctional core and at least one branch or one segment of thermoplastic polymer connected to the core, the core comprising at least three identical reactive functional groups, and the poly(alkylene oxide) block or blocks are connected to at least a portion of the free ends of the star or H macromolecular chain chosen from the ends of branches or segments of thermoplastic polymer and the ends of the polyfunctional core.