US 7,488,403 B2
Blends of glyoxalated polyacrylamides and paper strengthening agents
Cornel Hagiopol, 1176 Mandalay Ct., Lilburn, Ga. 30047 (US); Yuping Luo, 430 Arborshade Trace, Duluth, Ga. 30097 (US); David F. Townsend, 1475 Roanoke Trace, Grayson, Ga. 30017 (US); James W. Johnston, 2572 Collins Port Cove, Suwanee, Ga. 30024 (US); Clay E. Ringold, 145 Michigan Ave., Decatur, Ga. 30030 (US); and Karla D. Favors, 3323 Cedar Island Dr., Sw, Atlanta, Ga. 30311 (US)
Filed on Aug. 17, 2004, as Appl. No. 10/919,488.
Prior Publication US 2006/0037727 A1, Feb. 23, 2006
This patent is subject to a terminal disclaimer.
Int. Cl. D21H 17/55 (2006.01); C08F 8/00 (2006.01)
U.S. Cl. 162—168.3  [162/158; 162/164.3; 162/166; 525/328.3; 525/329.4; 525/383] 31 Claims
 
1. A composition for enhancing the wet strength of paper comprising a blend of two components:
(a) a polymeric paper strengthening agent; and
(b) a stabilized glyoxalated polyacrylamide in a concentration of between about 40% and about 99% by weight of the two components, wherein the stabilized glyoxalated polyacrylamide is prepared by (1) reacting a first portion of glyoxal with a polyacrylamide having pendant amide groups to form a first reaction mixture comprising glyoxalated polyacrylamide; (2) adding an acid to the first reaction mixture to form a second reaction mixture having a reduced pH and comprising the glyoxalated polyacrylamide; and (3) adding a second portion of glyoxal to the second reaction mixture to form the stabilized glyoxalated polyacrylamide.