Thermoplastic elastomer on basis of polypropylene/ethylene-propylene-diene terpolymer with crosslinked ethylene-propylene-diene terpolymer-phase, useful e.g. for shaped parts, preferably in the area of shock absorbing elements

摘要

Thermoplastic elastomer with an improved flow behavior on basis of polypropylene (PP)/ethylene-propylene-diene terpolymer (EPDM) with crosslinked EPDM-phase, is claimed, where in a twin-screw extruder, the raw materials including crosslinked resin, crosslinking catalyst and PP-degrading agent are added in the feeding zone, where the crosslinking of the soft phase takes place, while in a second section of the extruder in the following zones at clearly increased temperature, the thermoplastic phase is selectively reduced under effect of the PP-degrading agent. Thermoplastic elastomer with an improved flow behavior on basis of polypropylene (PP)/ethylene-propylene-diene terpolymer (EPDM) with crosslinked EPDM-phase, is claimed, where in a twin-screw extruder, the raw materials including crosslinked resin, crosslinking catalyst and PP-degrading agent are added in the feeding zone or alternatively in a following zone in a first section of the extruder, where the crosslinking of the soft phase takes place, while in a second section of the extruder in the following zones at clearly increased temperature, the thermoplastic phase is selectively reduced under effect of the PP-degrading agent. An independent claim is included for preparing thermoplastic elastomer in a continuously working twin-screw extruder, comprising: adding the raw materials in the feeding zone or alternatively a following zone of a first section of the extruder for carrying out the dynamic vulcanization; adjusting the mass temperature in the phase of the dynamic vulcanization at 180-220[deg] C, preferably 200[deg] C; increasing the mass temperature after carrying out the dynamic vulcanization of the EPDM at 220-260[deg] C, preferably 250[deg] C, for carrying out the selective degradation of the thermoplastic phase; adjusting the mass pressure at 20-30 bar, preferably 25 bar; and selecting a retention time in the twin-screw extruder of 1.5-3 minutes, preferably 2 minutes.