Thermoplastic packaging film of low I.sub.10 /I.sub.2
AssigneeW. R. Grace & Co.-Conn.
InventorThomas C. Warren
Life of this patent
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Abstract
Disclosed is a high abuse-resistance film suitable for making bags and pouches. The film has at least one layer comprising a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less. The copolymer has a comparatively lower I.sub.10 /I.sub.2 ratio than the corresponding ethylene/alpha-olefin with the same comonomer and essentially the same density and essentially the same melt index at condition 190/2.16.
Claims15
A heat-shrinkable packaging film of improved abuse resistance comprising at least one layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I.sub.10 /I.sub.2 melt flow ratio of about 7.2 when said alpha-olefin is octene or (b) a low I.sub.10 /I.sub.2 melt flow ratio of about 9.9 and a comonomer of hexene.
A thermoplastic, heat-shrinkable packaging film of improved abuse resistance comprising (I) a layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I.sub.10 /I.sub.2 ratio of about 7.2 when said alpha-olefin is octene or (b) a low I.sub.10 /I.sub.2 ratio of about 9.9 and a comonomer of hexene, and (II) a layer of barrier material.
A heat-shrinkable packaging film of improved abuse resistance comprising a layer of a linear copolymer of ethylene and an alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I.sub.10 /I.sub.2 melt flow ratio of about 7.2 and a comonomer of octene or (b) a low I.sub.10 /I.sub.2 melt flow ratio of about 9.9 when said alpha-olefin is hexene, said ethylene/alpha-olefin copolymer having a comparatively lower I.sub.10 /I.sub.2 ratio than the corresponding ethylene/alpha-olefin copolymer with the same comonomer and essentially the same density but a comparatively higher I.sub.10 /I.sub.2 ratio, said packaging film exhibiting better abuse resistance than the corresponding film made of the ethylene/alpha-olefin copolymer having the higher I.sub.10 /I.sub.2 ratio, wherein said lower I.sub.10 /I.sub.2 ratio and said higher I.sub.10 /I.sub.2 ratio differ by an amount above about 0.5.
A thermoplastic, mult-layer, heat-shrinkable packaging film having excellent abuse resistance, comprising in direct surface-to-surface contact at least the 4-layer structure:
- an outside polymer layer, a barrier layer, and interior layer, a heat sealing layer, wherein said interior layer comprises a linear copolymer of ethylene and an a alpha-olefin with a density of about 0.935 g/cc or less selected from ethylene/alpha-olefin copolymer having (a) a low I.sub.10 /I.sub.2 melt flow ratio of about 7.2 when said alpha-olefin is octene or (b) a low I.sub.10 /I.sub.2 melt flow ratio of about 9.9 and a comonomer of hexene.
Dependencies are inferred from the claim text.