Inhibition of water penetration into ballistic materials
View Patent ↗Ballistic resistant articles having excellent resistance to deterioration due to liquid exposure. More particularly, ballistic resistant fibrous composites and articles that retain their superior ballistic resistance performance after exposure to liquids such as sea water and organic solvents, such as gasoline and other petroleum-based products.
1. A fibrous composite material, comprising in order:
a) a first outer polymer film;
b) a first fibrous layer in contact with the first outer polymer film; the first fibrous layer comprising a plurality of fibers wherein said fibers are impregnated with a polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline;
c) a central polymer film in contact with the first fibrous layer;
d) a second fibrous layer in contact with the central polymer film; the second fibrous layer comprising a plurality of fibers wherein said fibers are impregnated with a polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline; and
e) a second outer polymer film in contact with the second fibrous layer;
wherein the first fibrous layer and the second fibrous layer each comprise fibers having a tenacity of about 7 g/denier or more and a tensile modulus of about 150 g/denier or more, wherein said polymeric binder material encapsulates each of the fibers such that 100% of the fiber surface area is covered with said binder material.
2. The fibrous composite material of claim 1 wherein the first fibrous layer and the second fibrous layer each comprise a single ply of non-woven, non-overlapping fibers that are aligned in a substantially parallel array.
3. The fibrous composite material of claim 2 wherein the parallel fibers of said first fibrous layer are positioned orthogonally to the parallel fibers of said second fibrous layer, relative to the longitudinal fiber direction of each fiber ply.
4. The fibrous composite material of claim 1 wherein the first fibrous layer and the second fibrous layer each comprise a plurality of consolidated non-woven fiber plies.
5. The fibrous composite material of claim 1 wherein the first fibrous layer and the second fibrous layer each comprise a plurality of overlapping non-woven fiber plies that are consolidated into a single element, wherein each ply comprises fibers aligned in a substantially parallel array and wherein each ply of a fibrous layer is positioned orthogonally to the parallel fibers of each adjacent ply within that fibrous layer relative to the longitudinal fiber direction of each fiber ply.
6. The fibrous composite material of claim 1 wherein the first fibrous layer and the second fibrous layer each consist of fibers that are impregnated with a polymeric binder material.
7. The fibrous composite material of claim 1 wherein said fibers of each fibrous layer comprise polyolefin fibers, aramid fibers, polybenzazole fibers, polyvinyl alcohol fibers, polyamide fibers, polyethylene terephthalate fibers, polyethylene naphthalate fibers, polyacrylonitrile fibers, liquid crystal copolyester fibers, rigid rod fibers comprising pyridobisimidazole-2,6-diyl(2,5-dihydroxy-p-phenylene), or a combination thereof.
8. The fibrous composite material of claim 1 wherein said polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline comprises a hydrolytically stable, polar polymer.
9. The fibrous composite material of claim 1 wherein said polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline comprises a polar, vinyl-based polymer.
10. The fibrous composite material of claim 1 wherein said polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline comprises a non-polar polymer modified with polar groups.
11. The fibrous composite material of claim 1 wherein said polymeric binder material that is resistant to dissolution by water and resistant to dissolution gasoline comprises a polar, hydrolytically stable thermoplastic polyurethane.
12. The fibrous composite material of claim 1 wherein said first outer polymer film, said central polymer film and said second outer polymer film comprise polyolefins, polyamides, polyesters, polyurethanes, vinyl polymers, fluoropolymers, or copolymers or combinations thereof.
13. The fibrous composite material of claim 1 wherein said first outer polymer film, said central polymer film and said second outer polymer film each comprise linear low density polyethylene.
14. The fibrous composite material of claim 1 wherein said polymeric binder material comprises from about 3% to about 16% by weight of each the first fibrous layer and the second fibrous layer.
15. A ballistic resistant article formed from the fibrous composite material of claim 1 .
16. A method of forming a fibrous composite material, comprising:
a) providing a first outer polymer film;
b) attaching a first fibrous layer to the first outer polymer film; the first fibrous layer comprising a plurality of fibers wherein said fibers are impregnated with a polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline;
c) attaching a central polymer film to the first fibrous layer;
d) attaching a second fibrous layer to the central polymer film; the second fibrous layer comprising a plurality of fibers wherein said fibers are impregnated with a polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline; and
e) attaching a second outer polymer film to the second fibrous layer;
wherein the first fibrous layer and the second fibrous layer each comprise fibers having a tenacity of about 7 g/denier or more and a tensile modulus of about 150 g/denier or more, wherein said polymeric binder material encapsulates each of the fibers such that 100% of the fiber surface area is covered with said binder material.
17. The method of claim 16 wherein the first fibrous layer and the second fibrous layer each comprise a single ply of non-woven, non-overlapping fibers that are aligned in a substantially parallel array.
18. The method of claim 17 wherein the parallel fibers of said first fibrous layer are positioned orthogonally to the parallel fibers of said second fibrous layer, relative to the longitudinal fiber direction of each fiber ply.
19. The method of claim 16 wherein the first fibrous layer and the second fibrous layer each comprise a plurality of consolidated non-woven fiber plies.
20. The method of claim 16 wherein the first fibrous layer and the second fibrous layer each comprise a plurality of overlapping non-woven fiber plies that are consolidated into a single element, wherein each ply comprises fibers aligned in a substantially parallel array and wherein each ply of a fibrous layer is positioned orthogonally to the parallel fibers of each adjacent ply within that fibrous layer relative to the longitudinal fiber direction of each fiber ply.
21. The method of claim 16 wherein the first fibrous layer and the second fibrous layer each comprise a woven array of fibers.
22. The method of claim 16 wherein said polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline comprises a polar, vinyl-based polymer.
23. The method of claim 16 wherein said polymeric binder material that is resistant to dissolution by water and resistant to dissolution by gasoline comprises a polar, hydrolytically stable thermoplastic polyurethane, which polyurethane has been modified with polar groups.
24. The method of claim 16 wherein said first outer polymer film, said central polymer film and said second outer polymer film comprise polyolefins, polyamides, polyesters, polyurethanes, vinyl polymers, fluoropolymers, or copolymers or combinations thereof.
25. The method of claim 16 wherein said polymeric binder material comprises a hydrolytically stable, polar polymer or comprises a non-polar polymer modified with polar groups.