Heterogeneous ethylene copolymers for the manufacture of films.

摘要

1. Copolymers of ethylene and of alpha-olefins comprising at least 4 carbon atoms, having a density lying between 0.905 and 0.940 g/cm**3 and a melt index lying between 0.2 and 2 dg/min., having an average content of alpha-olefin units lying between 1 and 8 mole percent and characterized in that the distribution of the alpha-olefin units along the backbone is heterogeneous, the said copolymer comprising crystalline fractions and amorphous fractions, and the content of alpha-olefin units along the backbone varies between at least 0.2 and at most 5 times the average content according to the fractions in question.