PROCESS FOR PRODUCING EXPANDABLE THERMOPLASTIC BEADS WITH IMPROVED EXPANDABILITY

摘要

Preparing cavities containing expandable thermoplastic polymer particles, comprises (i) extruding a propellant containing polymer melt comprising (in wt.%, based on the propellant containing polymer melt) nucleating agent (0.1-5), propellant (1-10) remaining in the polymer particles, and co-propellant (0.01-5 wt.%) forming cavities, through a die plate, and (ii) granulating it in a liquid filled chamber at a pressure of 1.5-15 bars. An independent claim is also included for cavities containing expandable thermoplastic polymer particles with an average diameter of 0.1-50 mm, obtainable by the above method.