Monoxially-oriented and annealed films with high cross machine toughness and related process
View Patent ↗A monoaxially-oriented polymeric film material formed from an impact copolymer and having increased toughness relative to films that are monoaxially-oriented at conventional temperatures.
1. A monoaxially-oriented polymeric film comprising at least one impact copolymer, wherein the polymeric film exhibits a cross-directional machine toughness greater than 3000 lbs/in 2 as measured according to ASTM-D4595 testing procedures on a 4× 5/32 inch wide sample of the monoaxially-oriented polymeric film.
2. The monoaxially-oriented polymeric film of claim 1 , further comprising an olefin-based polymer blended with said impact copolymer.
3. The monoaxially-oriented polymeric film of claim 2 , wherein said blend comprises:
a) from greater than 0 to about 70 parts by weight of said olefin-based polymer; and
b) at least about 30 parts by weight of said impact copolymer,
wherein the total of a) and b) is 100 parts by weight.
4. The monoaxially-oriented polymeric film of claim 2 , wherein said olefin-based polymer is polypropylene and said impact copolymer comprises a continuous phase of polypropylene with a dispersed phase of propylene/ethylene rubber.
5. The monoaxially-oriented polymeric film of claim 2 , wherein said olefin-based polymer has a melt flow index of from about 0.6 to about 5 and wherein said impact copolymer has a melt flow index of from about 0.6 to about 3.5.
6. The monoaxially-oriented polymeric film of claim 2 , wherein the olefin-based polymer comprises a C 2 -C 8 olefin homopolymer.
7. The monoaxially-oriented polymeric film of claim 1 , having a melt flow index of from about 1.7 to about 3.2.
8. The monoaxially-oriented polymeric film of claim 1 , wherein the impact copolymer comprises a heterophasic copolymer.
9. The monoaxially-oriented polymeric film of claim 1 , wherein the impact copolymer exhibits a melting point of at least about 160° C.
10. The monoaxially-oriented polymeric film of claim 1 , wherein the cross-directional machine toughness is greater than 5000 lbs/in 2 .
11. The monoaxially-oriented polymeric film of claim 1 , wherein the cross-directional machine toughness is greater than 12,000 lbs/in 2 .
12. The monoaxially-oriented polymeric film of claim 1 , wherein the cross-directional machine toughness is in the range of from about 5,000 lbs/in 2 to about 16,000 lbs/in 2 .
13. The monoaxially-oriented polymeric film of claim 1 , wherein the film exhibits a shrinkage percentage less than approximately 2% when measured at 135° C.
14. A monoaxially-oriented polymeric film comprising:
an olefin-based polymer; and
an impact copolymer having a melting point of at least about 160° C.;
wherein the polymeric film exhibits
a cross-directional machine toughness greater than 3000 lbs/in 2 as measured according to ASTM-D4595 testing procedures on a 4× 5/32 inch wide sample of the monoaxially-oriented polymeric film.
15. The monoaxially-oriented polymeric film of claim 14 , wherein the film comprises:
a) from greater than 0 to about 70 parts by weight of said olefin-based polymer; and
b) at least about 30 parts by weight of said impact copolymer,
wherein the total of a) and b) is 100 parts by weight.
16. The monoaxially-oriented polymeric film of claim 14 , wherein said olefin-based polymer is polypropylene and said impact copolymer comprises a continuous phase of polypropylene with a dispersed phase of propylene/ethylene rubber.
17. The monoaxially-oriented polymeric film of claim 14 , wherein the olefin-based polymer comprises a C 2 -C 8 olefin homopolymer.
18. The monoaxially-oriented polymeric film of claim 14 , wherein the polymeric film exhibits a shrinkage percentage less than approximately 2% when measured at 135° C.
19. A monoaxially-oriented polymeric film comprising:
an olefin-based polymer comprising a C 2 -C 8 olefin homopolymer; and
an impact copolymer comprising a continuous phase of polypropylene with a dispersed phase of propylene/ethylene rubber;
wherein the polymeric film exhibits
a cross-directional machine toughness in a range of from about 3,000 lbs/in 2 to about 16,000 lbs/in 2 as measured according to ASTM-D4595 testing procedures on a 4× 5/32 inch wide sample of the monoaxially-oriented polymeric film.
20. The monoaxially-oriented polymeric film of claim 19 , wherein said olefin-based polymer is polypropylene.