Method and composition for increasing the strength of compositions containing high-bulk fibers
AssigneeWeyerhaeuser Company
InventorJohn A. Westland
Life of this patent
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Abstract
Crosslinked cellulose fibers having free pendant carboxylic acid groups are disclosed. The fibers include a polycarboxylic acid covalently coupled to the fibers, and are crosslinked with a crosslinking agent having a cure temperature lower than the cure temperature of the polycarboxylic acid. Methods for producing the fibers and for producing a fibrous sheet incorporating the fibers are also disclosed.
Claims25
Individualized, crosslinked cellulose fibers having free pendant carboxylic acid groups, comprising cellulose fibers crosslinked with a crosslinking agent, and a polycarboxylic acid covalently coupled to the fibers, wherein the crosslinking agent has a cure temperature below the cure temperature of the polycarboxylic acid, and wherein the polycarboxylic acid provides free pendant carboxylic acid groups to the fibers.
A fiber sheet comprising individualized cellulose fibers crosslinked with a crosslinking agent, and a polycarboxylic acid covalently coupled to the fibers, wherein the crosslinking agent has a cure temperature below the cure temperature of the polycarboxylic acid, and wherein the polycarboxylic acid provides free pendant carboxylic acid groups to the fibers.
An absorbent product comprising individualized cellulose fibers crosslinked with a crosslinking agent, and a polycarboxylic acid covalently coupled to the fibers, wherein the crosslinking agent has a cure temperature below the cure temperature of the polycarboxylic acid, and wherein the polycarboxylic acid provides free pendant carboxylic acid groups to the fibers.
A method for producing individualized, crosslinked cellulose fibers having free pendant carboxylic acid groups, comprising:
- applying a polycarboxylic acid to cellulose fibers;
- applying a crosslinking agent having a cure temperature below the cure temperature of the polycarboxylic acid to the cellulose fibers;
- and
- curing the polycarboxylic acid and the crosslinking agent at a temperature sufficient to effect intrafiber crosslink formation, and ester bond formation between the polycarboxylic acid and the crosslinked cellulose fibers to produce crosslinked cellulose fibers having free pendant carboxylic acid groups.
A method for producing a high-bulk cellulose fiber sheet having increased tensile strength, comprising:
- combining untreated fibers and crosslinked cellulose fibers having free pendant carboxylic acid groups to provide combined fibers wherein the crosslinked cellulose fibers comprise cellulose fibers crosslinked with a crosslinking agent, and a polycarboxylic acid covalently coupled to the crosslinked cellulose fibers, wherein the crosslinking agent has a cure temperature below the cure temperature of the polycarboxylic acid, and wherein the polycarboxylic acid provides free pendant carboxylic acid groups to the crosslinked cellulose fibers;
- and
- forming the combined fibers into a sheet to produce a high-bulk cellulose fiber sheet having increased tensile strength compared to fiber sheets prepared from the untreated fibers and crosslinked fibers having no pendant carboxylic acid groups.
Dependencies are inferred from the claim text.