	US 7,329,701 B2
	Superabsorbent polymers and method of manufacturing the same
Norbert Herfert, Charlotte, N.C. (US); Michael M. Azad, Charlotte, N.C. (US); Michael A. Mitchell, Waxhaw, N.C. (US); Guy Thomas Woodrum, Suffolk, Va. (US); William G.-J. Chiang, Yorktown, Va. (US); Patricia D. Brown, Charlotte, N.C. (US); and James C. Robinson, Chesapeake, Va. (US)
Assigned to BASF Aktiengesellschaft, Ludwigshafen (Germany)
Appl. No. 10/522,937 PCT Filed Jul. 24, 2003, PCT No. PCT/EP03/08087 § 371(c)(1), (2), (4) Date Jan. 31, 2005, PCT Pub. No. WO2004/018005, PCT Pub. Date Mar. 04, 2004.
Claims priority of provisional application 60/405477, filed on Aug. 23, 2002.
Prior Publication US 2005/0239942 A1, Oct. 27, 2005
This patent is subject to a terminal disclaimer.
Int. Cl. C08K 3/34 (2006.01)

U.S. Cl. 524—445 [524/556; 524/832; 525/330.2]

29 Claims

1. Superabsorbent particles comprising:

(i) about 50% to about 95%, by weight, of a superabsorbent polymer; and

(ii) about 5% to about 50%, by weight, of a clay, said particles prepared by a method comprising the steps of:

(a) polymerizing an unneutralized monomer capable of providing a superabsorbent absorbent polymer in the presence of an internal crosslinking monomer to form a superabsorbent polymer hydrogel;

(b) comminuting the superabsorbent polymer hydrogel to form superabsorbent polymer hydrogel particles;

(c) admixing a clay with the superabsorbent polymer hydrogel particles to form superabsorbent polymer-clay hydrogel particles;

(d) then neutralizing the superabsorbent polymer-clay hydrogel particles by adding a sufficient amount of a neutralizing agent to neutralize the hydrogel particles 50% to 100%, by weight; and

(e) drying the neutralized superabsorbent polymer-clay hydrogel particles of step (d) to provide the superabsorbent particles.