Thermoplastic compositions of atactic and syndiotactic polypropylene

摘要

Thermoplastic polymer compositions are disclosed which comprise the following components: (A) 1 to 99% by weight of an amorphous propylene polymer having the following characteristics: Ä eta Ü > 1 dl/g, % of syndiotactic dyads (r) - % of isotactic dyads (m) > 0, less than 2% of the CH2 groups contained in (CH2)n sequences wherein n >/= 2, Bernoullianity index = 1 +/- 0.2; and (B) 1 to 99% by weight of a propylene polymer having an essentially syndiotactic structure, optionally containing from 0.1 to 30% by moles of units deriving from alpha -olefins of formula CH2=CHR in which R is an hydrogen atom or an alkyl group having from 2 to 10 carbon atoms. The compositions of the invention are endowed with good elasto-mechanical properties and are suitable for the production of low-temperature-heat-sealing films.