Fibers of variable wettability and materials containing the fibers
View Patent ↗The present invention is directed to an absorbent material and the fibers therein, having two or more layers including an upper surface layer which has on the outer surface of the layer one or more surface area zones which are more wettable zones and adjacent thereto one or more less wettable zones, where the more wettable zones have a greater hydrophilicity than the less wettable zone. The present invention is also directed to the fibers therein, which contain polyvalent cation-containing compounds and fatty acid containing compounds. The present invention also provides for methods of treating fibers or solid materials and processes of producing the hydrophobic materials.
1. An absorbent material comprising two or more layers, wherein one layer is an upper surface layer which has on an outer surface of the layer one or more surface area zones which are more wettable zones and adjacent thereto one or more less wettable zones, wherein the more wettable zones have a greater hydrophilicity than the less wettable zones, and wherein the upper surface layer comprises cellulosic fibers bound with a dissociating polyvalent cation-containing compound in an amount from about 0.1 weight percent to about 20 weight percent based on the dry weight of the cellulosic fiber prior to treatment with the bound polyvalent cation-containing compound and the less wettable zones comprise a fatty acid containing compound in an amount from about 0.01 weight percent to about 5 weight percent.
2. The absorbent material of claim 1 , wherein the zones are hydrophilic with the more wettable zones having a greater hydrophilicity than that of the less wettable zones.
3. The absorbent material of claim 1 , wherein the zones are hydrophobic with the more wettable zones having a lower hydrophobicity than that of the less wettable zones.
4. The absorbent material of claim 1 , wherein the more wettable zones are hydrophilic and the less wettable zones are hydrophobic.
5. The absorbent material of claim 1 , wherein the more wettable zones have a total surface area which is from about 5 percent to about 95 percent of the upper surface layer.
6. The absorbent material of claim 1 , wherein the more wettable zones have a total surface area which is from about 10 percent to about 90 percent of the upper surface layer.
7. The absorbent material of claim 1 , wherein the more wettable zones have a total surface area which is from about 20 percent to about 80 percent of the upper surface layer.
8. The absorbent material of claim 1 , wherein the more wettable zones have a total surface area which is from about 30 percent to about 70 percent of the upper surface layer.
9. The absorbent material of claim 1 , wherein the more wettable zones have elements in a pattern which are all connected, the elements of the pattern essentially isolating the less wettable zones from each other.
10. The absorbent material of claim 1 , wherein the less wettable zones have elements in a pattern which are all connected, the elements of the pattern essentially isolating the more wettable zones from each other.
11. The absorbent material of claim 1 , wherein the upper surface layer is less wettable than an adjacent more wettable lower layer, wherein the upper surface layer has protrusions that project above the surface of the material and indentations that project below the surface of the upper surface layer, and wherein the protrusions of the upper surface layer are at a greater distance from the lower layer than the indentations of the upper surface layer.
12. The absorbent material of claim 1 , wherein a lower layer adjacent to the upper surface layer comprises chemically treated cellulose fibers.
13. The absorbent material of claim 1 , wherein the less wettable zones are located on protrusions that project above the surface of the upper surface layer and the more wettable zones are located in indentations that project below the surface of the upper surface layer.