Composition and process for reducing the adhesive nature of ethylene/alpha-olefins copolymers
AssigneeSofrapocommerciale
InventorsBrigitte Morese-Seguela, Urbain Coudevylle
Life of this patent
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Abstract
The process, which makes it possible to reduce the adhesive nature of a partially crystalline copolymer (E) of ethylene and at least one alpha-olefin with a density of between 0.865 and 0.900 approximately, and to increase its resistance to crushing, consists in mixing closely said ethylene copolymer with at least one non-atactic propylene polymer (P) with a fluidity index (measured according to the ASTM D 1238 standard, condition L) between 35 and 200 dg/min. approximately, in a proportion of between 22 to 50 parts by weight approximately for 100 parts by weight of ethylene copolymer.
Claims17
A process for reducing the adhesive nature and for increasing the crush resistance of granules of a partially-crystalline ethylene/alpha-olefin copolymer of ethylene and at least one alpha-olefin, said ethylene/alpha-olefin copolymer having a density between 0.865 and 0.900 g/cm.sup.3 and exhibiting no Mooney viscosity, comprising forming said granules from a composition consisting essentially of an intimate ethylene polymer and propylene polymer blend consisting of said ethylene/alpha-olefin copolymer and at least one nonatactic propylene polymer having a melt index of between 35 and 200 dg/minute in a proportion of from 22 to 50 parts by weight per 100 parts by weight of said ethylene/alpha-olefin copolymer.
A thermoplastic article formed from granules consisting essentially of an intimate ethylene polymer and propylene polymer blend consisting of 100 parts by weight of a partially-crystalline ethylene/alpha-olefin copolymer of ethylene and at least one alpha-olefin, said ethylene/alpha-olefin copolymer having a density between 0.865 and 0.900 g/cm3 and exhibiting no Mooney viscosity, and from 22 to 50 parts by weight of at least one nonatactic propylene polymer having a melt index of between 35 and 200 dg/minute.
A thermoplastic article formed from granules according to claim 16 wherein the ethylene/alpha-olefin copolymer has a degree of crystallinity of at least 1%.
A thermoplastic article formed from granules according to claim 16 wherein the propylene polymer is an isotactic polypropylene polymer having a relative density of between 0.89 and 0.91 g/cm.sup.3, an isotacticity index of at least 94% and a degree of crystallinity of at least 45%.
Granules consisting essentially of an intimate ethylene polymer and propylene polymer blend consisting of 100 parts by weight of a partially-crystalline ethylene/alpha-olefin copolymer having a density between 0.865 and 0.900 g/cm.sup.3 and exhibits no Mooney viscosity, and 22 to 50 parts by weight of at least one nonatactic propylene polymer having a melt index of between 35 and 200 dg/minute.
Dependencies are inferred from the claim text.