Patents Assigned to Evonik Stockhausen, Inc.
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Patent number: 7910688Abstract: A process is described for recycling superabsorbent polymer fines into a process that includes treating the superabsorbent polymer fines with caustic and a polymerization step for making the superabsorbent polymer gel. The process requires treating the superabsorbent polymer fines with a caustic, followed by mixture with polymerizable monomer solution, and polymerizing the mixture of the superabsorbent polymer fines and monomer to form the aqueous fluid absorbent polymer. In the process, the fines are incorporated into the new polymer gel and become indistinguishable there from. The gel may then be comminuted into a particulate dried and then separated into a portion having a desired minimum particle size in a fines portion having less than the desired size. The particulate may then be coated with a surface crosslinking agent and surface additives and heated for surface conversion.Type: GrantFiled: October 22, 2008Date of Patent: March 22, 2011Assignee: Evonik Stockhausen Inc.Inventors: Gonglu Tian, Scott J. Smith, Janet Pate-Linton
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Patent number: 7696401Abstract: An absorbent material formed at least in part of a cross-linked polymer. The absorbent material has a centrifuge retention capacity as determined by a Centrifuge Retention Capacity Test of at least about 20 g/g and a gel bed permeability under load as determined by a Gel Bed Permeability Under Load Test of at least about 300×10?9 cm2 or a free swell gel bed permeability as determined by a Free Swell Gel Bed Permeability Test of at least about 2,500×10?9 cm2. The cross-linked polymer may comprise either at least about 75 weight percent anionic polymer or at least about 75 weight percent cationic polymer. In one embodiment, the cross-linked polymer is surface treated with a water soluble non-cross-linked polymer having a potential for becoming charged opposite that of the cross-linked polymer.Type: GrantFiled: July 31, 2003Date of Patent: April 13, 2010Assignee: Evonik Stockhausen, Inc.Inventors: Jian Qin, Xiaomin Zhang, Debra Ann Miller
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Patent number: 7615579Abstract: The invention relates to a superabsorbent polymer wherein an increased rate of water absorption is obtained by the addition of an encapsulated blowing agent. The invention relates to a superabsorbent polymer including an encapsulating blowing agent and having a vortex time of 40 seconds or less. In particular, the superabsorbent polymer includes from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers; from about 0.001 to about 5.0 wt. % of internal crosslinking agent; wherein the wherein the composition has a degree of neutralization of more than about 20%; and from about 0.05 to about 10.0 wt. % of an encapsulated blowing agent.Type: GrantFiled: December 14, 2006Date of Patent: November 10, 2009Assignee: Evonik Stockhausen, Inc.Inventors: Mark C. Joy, Whei-Neen Hsu
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Patent number: 7579402Abstract: The present invention is directed to a coated superabsorbent polymer comprising a coated superabsorbent polymer having a delayed free water absorption property of absorbing about 13 grams or less of water per gram of superabsorbent polymer in about 15 seconds. The present invention is directed to a coated superabsorbent polymer having delayed water absorption comprising a) a composition comprising from about 55 to about 99.9 wt. % of polymerizable unsaturated acid group containing monomers; and from about 0.001 to about 5.0 wt. % of internal crosslinking agent; wherein the composition has a degree of neutralization of more than about 20%; and b) a salt coated on the composition.Type: GrantFiled: November 12, 2003Date of Patent: August 25, 2009Assignee: Evonik Stockhausen, Inc.Inventors: Iqbal Ahmed, Angela Marie Jones, Scott J. Smith
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Patent number: 7488541Abstract: The present invention is directed to an aqueous superabsorbent polymer paste comprising from about 1 to about 5 wt % of superabsorbent particles and from about 95 to about 99 wt % of an aqueous water-soluble solution having from about 0.5 to about 5%, preferably from about 1 to about 3% solid level. The present invention is also directed to a coated substrate comprising a substrate material and an aqueous superabsorbent polymer paste comprising a blend of i) from about 1 to about 5 wt % of superabsorbent particles and ii) from about 95 to about 99 wt % of an aqueous water-soluble solution. The present invention is also directed to a method for reducing the loss of circulation fluids into flow passages of a subterranean formation during well drilling, completion or work over operations, by using the aqueous superabsorbent polymer paste of the present invention.Type: GrantFiled: December 14, 2006Date of Patent: February 10, 2009Assignee: Evonik Stockhausen, Inc.Inventors: Iqbal Ahmed, Angela M. Jones, Scott Tomlin, Scott J. Smith