process for the manufacture of sheets having improved properties at elevated temperatures elastomeriche

摘要

Thermoplastic rubber, polystyrene, polyethylene, ethylene/propylene/diene terpolymer, carbon black, plasticiser, antiageing agent and/or stabiliser, lubricant and, if appropriate, a graft copolymer of ethylene/propylene/diene terpolymer and high-impact polystyrene, filler and polyisobutylene with an intrinsic viscosity of 3.8-4.6 dl/g are homogeneously mixed together at 100-155 DEG C. The mixture is extruded at approximately 125 DEG C by means of an extruder with a high pressure screw with continually progressive pitch and a compression ratio of 1:2.8 through an annular die to form a tubular film. The film obtained has excellent resistance to environmental stress cracking and ageing and outstanding buckling resistance and tear strength. A watertight bonding of webs of such films can be obtained by solvent welding.