Moisture barrier films
A multilayer moisture barrier film includes at least one desiccant-containing layer disposed adjacent to at least one desiccant free layer, where the at least one desiccant-containing layer comprises a polymeric matrix defining a plurality of cavities and desiccant particles, wherein at least one of the plurality of cavities has at least one desiccant particle in communication therewith.
1 . A barrier film comprising at least one desiccant-containing layer disposed adjacent to at least one desiccant free layer:
the at least one desiccant-containing layer comprising a polymeric matrix defining a plurality of cavities and comprising desiccant particles, wherein at least one of the plurality of cavities has at least one desiccant particle in communication therewith, and wherein the at least one desiccant-containing layer comprises from about 0.1 wt. % to about 12 wt. % of the desiccant particles; and
the at least one desiccant free layer a polymer matrix, and the at least one desiccant free layer comprises from about 20% to about 60% of the overall thickness of the packaging film.
2 . The film of claim 1 , wherein the at least one desiccant free layer comprises from about 30% to about 50% of the overall thickness of the packaging film.
3 . The film of claim 1 , wherein the at least one desiccant-containing layer is uniaxially or biaxially oriented.
4 . The film of claim 3 , wherein the at least one desiccant-containing layer is biaxially oriented and is oriented 2 to 6 times in the machine direction, and 2 to 6 times in the transverse direction.
5 . The film of claim 3 , wherein the at least one desiccant-containing layer is is biaxially oriented and oriented 4 times in the machine direction and 6 times in the transverse direction.
6 . The film of claim 3 , wherein the at least one desiccant-containing layer is is biaxially oriented and oriented 2 times in the machine direction and from 4 to 6 times in the transverse direction.
7 . The film of claim 1 , wherein the desiccant particles are selected from fumed silica particles.
8 . The film of claim 1 , wherein the at least one desiccant free layer comprises a first desiccant free layer and a second desiccant free layer, and one of the at least one desiccant-containing layers is disposed between the first and second desiccant free layers.
9 . The film of claim 8 , wherein the first and second desiccant free layers comprise from about 30% to about 50% of the overall thickness of the packaging film.
10 . The film of claim 9 , wherein the at least one desiccant-containing layer is uniaxially or biaxially oriented.
11 . The film of claim 10 , wherein the at least one desiccant-containing layer is biaxially oriented and is oriented 2 to 6 times in the machine direction, and 2 to 6 times in the transverse direction.
12 . The film of claim 10 , wherein the at least one desiccant-containing layer is biaxially oriented and is oriented 4 times in the machine direction and 6 times in the transverse direction.
13 . The film of claim 10 , wherein the at least one desiccant-containing layer is biaxially oriented and is oriented 2 times in the machine direction and from 4 to 6 times in the transverse direction.
14 . The film of claim 8 , wherein the desiccant particles are selected from fumed silica particles.
15 . A package defining an interior space for holding a product, the package comprising the film of claim 8 .
16 . The film of claim 1 , wherein the at least one desiccant-containing layer comprises a first desiccant-containing layer and a second desiccant-containing layer, and the at least one-desiccant free layer comprises a first desiccant free layer disposed between the first desiccant-containing layer and the second desiccant-containing layer, a second desiccant free layer disposed adjacent the first desiccant-containing layer and opposite the first desiccant free layer, and a third desiccant free layer disposed adjacent the second desiccant-containing layer and opposite the first desiccant free layer.
17 . The film of claim 16 , wherein the first, second, and third desiccant free layers comprise from about 30% to about 50% of the overall thickness of the packaging film.
18 . The film of claim 17 , wherein the at least one desiccant-containing layer is uniaxially or biaxially oriented.
19 . The film of claim 18 , wherein the at least one desiccant-containing layer is biaxially oriented and is oriented 2 to 6 times in the machine direction, and 2 to 6 times in the transverse direction.
20 . The film of claim 18 , wherein the at least one desiccant-containing layer is biaxially oriented and is oriented 4 times in the machine direction and 6 times in the transverse direction.
21 . The film of claim 18 , wherein the at least one desiccant-containing layer is biaxially oriented and is oriented 2 times in the machine direction and from 4 to 6 times in the transverse direction.
22 . A package defining an interior space for holding a product, the package comprising the film of claim 16 .
23 . The film of claim 16 , wherein the desiccant particles are selected from fumed silica particles.
24 . A package defining an interior space for holding a product, the package comprising the film of claim 1 .
25 . The package of claim 24 , wherein the at least one desiccant-containing layer comprises an outer layer of the film.
26 . The film of claim 25 , wherein the at least one desiccant free layer comprises an outer layer of the film.