| 摘要 |
This invention discloses a multi-layer film for making pouches for containing flowable materials, said multi-layer film comprising generally five layers in order: inner sealant-layer, first interposed layer, the core layer, second interposed layer, and the outer sealant layer. The sealant and core layers are ethylene-based, and the interposed layers are polypropylene-based. The multi-layer film thickness is in the range of from about 35 microns to about 66 microns. The interposed layers comprise a novel polypropylene blend with a major component polypropylene and a minor component polypropylene, wherein the minor component polypropylene is a heterogeneous polypropylene interpolymer with a density in the range of from about 0.875 to about 0.91 g/cm3. |
| 主权项 |
1. A multi-layer film for making pouches for containing flowable materials, said multi-layer film comprising the following layers in order, from an at least one inner sealant-layer to an at least one outer sealant-layer:
(A) said at least one inner sealant-layer comprising polyethylene that is selected from the group consisting of:
(i) an at least one low-density ethylene-alpha-olefin copolymer,(ii) a blend of said at least one low-density ethylene-alpha-olefin homopolymer, wherein said ethylene homopolymer is made in a high-pressure polymerization process; and(iii) a blend of said at least one low-density ethylene-alpha-olefin copolymer and an at least one ethylene copolymer, wherein said ethylene copolymer is made in a high-pressure polymerization process; (B) a first at least one interposed layer adjacent to said at least one inner sealant-layer, said first at least one interposed layer comprising:
(i) an at least one polypropylene blend comprising a major componentpolypropylene and a minor component polypropylene, wherein said major component polypropylene in the range of from about 50% to 90% of weight of said first at least one interposed layer, and said minor component polypropylene is in the range of from about 10% to about 49% of weight of said first at least one interposed layer;(ii) optionally, an at least one ethylene-alpha-olefin copolymer; and(iii) optionally, a second ethylene-alpha-olefin copolymer that is not the same as said at least one ethylene-alpha-olefin copolymer in (B)(ii);wherein the centerline of said first at least one interposed layer is closer to the centerline of said at least one inner sealant-layer than to the centerline of said multi-layer film; (C) at least one core layer, adjacent to said first at least one interposed layer, said at least one core layer comprising polyethylene that is selected from the group consisting of:
(i) at least one low-density ethylene-alpha olefin copolymer,(ii) a blend of said at least one low-density ethylene-alpha-olefin copolymer and an at least one ethylene homopolymer, wherein said ethylene homopolymer is made in a high-pressure polymerization process; and(iii) a blend of said at least one low-density ethylene-alpha-olefin copolymer and an at least one ethylene copolymer, wherein said ethylene copolymer is made in a high-pressure polymerization process; (D) a second at least one interposed layer adjacent to said at least one core
(i) an at least one polypropylene blend comprising a major component polypropylene and a minor component polypropylene, wherein said major component polypropylene in the range of from about 50% to 90% of weight of said first at least one interposed layer, and said minor component polypropylene is in the range of from about 10% to about 49% of weight of said first at least one interposed layer;(ii) optionally, an at least one ethylene-alpha-olefin copolymer; and(iii) optionally, a second ethylene-alpha-olefin copolymer that is not the same as said at least one ethylene-alpha-olefin copolymer in (D)(ii);wherein the centerline of said second at least one interposed layer is closer to the centerline of said at least one outer sealant-layer than to the centerline of said multi-layer film; and (E) said at least one outer sealant-layer, comprising polyethylene that is selected from the group consisting of:
(i) an at least one low-density ethylene-alpha-olefin copolymer,(ii) a blend of said at least one low-density ethylene-alpha-olefin copolymer and an at least one ethylene homopolymer, wherein said ethylene homopolymer is made in a high-pressure polymerization process; and(iii) a blend of said at least one low-density ethylene-alpha-olefin copolymer and an at least one ethylene copolymer, wherein said ethylene copolymer is made in a high-pressure polymerization process;wherein said multi-layer film thickness is in the range of from about 35 microns to about 66 microns;wherein a combined thickness of said first at least one interposed layer and said second at least one interposed layer is in the range of from about 10% to about 27% of the total thickness of said multi-layer film;wherein a combined thickness of said inner sealant-layer and said outer sealant-layer is in the range of from about 10% to about 27% of the total thickness of said multi-layer film. |
