A copolymer based on ethylene and propylene, having a density of between 0.933 and 0.946 g/cm.sup.3 and a melt index of between 2 and 10 dg/min, wherein the copolymer has from 3 to 27 alkyl groups per 1000 carbon atoms in the molecule and wherein its density .rho. and its proportion m of alkyl...http://www.google.fr/patents/US4424330?utm_source=gb-gplus-shareBrevet US4424330 - Ethylene-propylene copolymers
