Individualized cellulosic fibers crosslinked with polyacrylic acid polymers

• US 5,549,791 A
• Filed: 06/15/1994
• Issued: 08/27/1996
• Est. Priority Date: 06/15/1994
• Status: Expired due to Term

• Current Assignee: Weyerhaeuser NR Company (Weyerhauser)
• Original Assignee: The Procter & Gamble Company
• Inventors: Dean, Walter L., Herron, Carlisle M.
• Primary Examiner(s): Czaja, Donald E.
• Assistant Examiner(s): Fortuna, Jose A.
• Application Number:
  US08/259,842
• Time in Patent Office: 804 Days
• Field of Search: 162/157.2, 162/157.1, 162/157.3, 162/157.4, 162/157.5, 162/157.6, 162/157.7, 162/158, 162/146, 162/9, 428/361, 428/365, 428/368, 428/391, 428/392, 428/393, 428/394, 428/375
• US Class Current: 162/157.6
• CPC Class Codes: A61L 15/24 Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives thereof A61L15/225 takes precedence
• CPC Class Codes: A61L 15/28 Polysaccharides or their derivatives A61L15/225 takes precedence
• CPC Class Codes: C08L 1/00 Compositions of cellulose, modified cellulose or cellulose derivatives
• CPC Class Codes: C08L 33/02 Homopolymers or copolymers of acids; Metal or ammonium salts thereof
• CPC Class Codes: D04H 1/42 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
• CPC Class Codes: D06M 13/207 Substituted carboxylic acids, e.g. by hydroxy or keto groups; Anhydrides, halides or salts thereof
• CPC Class Codes: D06M 14/04 of vegetal origin, e.g. cellulose or derivatives thereof
• CPC Class Codes: D06M 15/263 of unsaturated carboxylic acids; Salts or esters thereof
• CPC Class Codes: D21C 9/005 organic compounds

Abstract

Disclosed are individualized, crosslinked fibers, and processes for making such fibers, and absorbent structures containing the fibers. The individualized, crosslinked fibers have a polymeric polyacrylic acid crosslinking agent reacted with the fibers in the form of intrafiber crosslink bonds. Preferably, the crosslinking agent is a copolymer of acrylic acid and maleic acid and preferably, between about 1.0 weight % and about 10.0 weight % of the crosslinking agent reacts with the individualized fibers to form the intrafiber crosslink bonds. The individualized, crosslinked fibers are useful in a variety of absorbent structure applications. The absorbent structures may also contain hydrogel-forming material.

Claims

1. Individualized, crosslinked cellulosic fibers, said fibers having between about 1.0 weight % and about 10.0 weight % of a polymeric polyacrylic acid crosslinking agent, calculated on a dry fiber weight basis, reacted with said fibers in an ester intrafiber crosslink bond form, wherein said polymeric polyacrylic acid crosslinking agent is a copolymer of acrylic acid and maleic acid, said copolymer having a molecular weight from about 500 to about 40,000, wherein said crosslinking agent is sufficiently reacted with said fibers in intrafiber bond form to cause said fibers to have a water retention value of from about 25 to about 60, and wherein the weight ratio of acrylic acid to maleic acid is from about 5:

1 to 1.5;

1.

2. The individualized, crosslinked fibers of claim 1 wherein said crosslinking agent has a molecular weight of from about 1,000 to about 20,000.