Production of polyester-reinforced polypropylene for high-strength molded parts involves compounding iso- or syndiotactic polypropylene with chopped polyester fibre under specified temperature conditions

摘要

Polyester-reinforced polypropylene is obtained by compounding isotactic or syndiotactic metallocene-polypropylene (PP) with a chopped polyester fibre and optionally a filler, a glass fibre, a coupling agent and/or a natural or regenerated cellulose fibre at below the softening point of the polyester and at least 10 deg K above the m.pt. of PP. A process for the production of polyester-reinforced polypropylene compounds (I) involves compounding (A) 50-95 parts by weight (pts. wt.) isotactic or syndiotactic metallocene-polypropylene (PP) with (B) 5-50 pts. wt. chopped polyester fibres, (C1) 0-40 pts. wt. filler, (C2) 0-40 pts. wt. glass fibres, (C3) 0-5 pts. wt. coupling agent (e.g. polypropylene homo- or co-polymer modified with maleic anhydride, stearic acid or acrylic acid) and (C4) 0-40 pts. wt. natural fibre (e.g. jute, flax or hemp) or regenerated cellulose fibres in an extruder or plastifier at below the softening point of (B) and at least 10 deg K above the melting point of PP.