Method for enhancing the softness of a fibrous web

• US 6,579,414 B2
• Filed: 09/27/2002
• Issued: 06/17/2003
• Est. Priority Date: 12/29/1998
• Status: Expired due to Term

• Current Assignee: International Paper Company
• Original Assignee: Weyerhaeuser Company (Weyerhauser)
• Inventors: Jewell, Richard A.
• Primary Examiner(s): Fortuna, Jose A.
• Application Number:
  US10/260,867
• Publication Number:
  US 20030037890A1
• Time in Patent Office: 263 Days
• Field of Search: 162/9, 162/157.6, 162/157.1, 162/146, 162/141, 162/158, 162/164.3, 162/164.6, 162/168.2, 162/175, 162/169, 162/182, 811/551, 811/556, 811/61, 818/1, 811/9-1-0, 812/9
• US Class Current: 162/157.6
• CPC Class Codes: D06M 13/192 Polycarboxylic acids; Anhydrides, halides or salts thereof D06M13/1845 takes precedence
• CPC Class Codes: D06M 15/263 of unsaturated carboxylic acids; Salts or esters thereof
• CPC Class Codes: D21C 9/005 organic compounds
• CPC Class Codes: D21H 11/20 Chemically or biochemically modified fibres

Abstract

Carboxylated cellulosic fibers are disclosed. The fibers include a polycarboxylic acid covalently coupled to the fibers. Methods for producing the fibers and for producing fibrous products that incorporate the fibers are also disclosed.

Claims

1. A method for enhancing the softness of a fibrous web, comprising

forming a fibrous slurry, wherein the slurry comprises individualized carboxylated cellulosic fibers, the fibers comprising cellulosic fibers covalently coupled to a carboxylating agent through an ester bond, wherein the carboxylating agent provides a carboxyl group to the fibers, and wherein the carboxylating agent is a polycarboxylic acid having one carboxyl group separated from a second carboxyl group by either two or three atoms, wherein the carboxylated fibers have a water retention value greater than or equal to the water retention value of the fibers from which the carboxylated fibers are formed;

depositing the fibrous slurry on a foraminous support;

dewatering the deposited slurry to provide a wet composite; and

drying the wet composite to provide a fibrous web having a softness greater than a fibrous web formed from a fibrous slurry lacking carboxylated cellulosic fibers.