Patents by Inventor Stefan Wickel
Stefan Wickel has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7393908Abstract: The invention relates to a cross-linked, water-swellable polymer that contains polymerized into it moieties of a) water-soluble, monoethylenically unsaturated monomers, and b) 0.001 to 5 mole % based on the monomers a) of a cross-linking combination, b1) a frist cross-linking agent with at least two (meth)acrylic ester moieties in the molecule and b2) a second cross-linking agent with at least two (meth)allyloxy moieties in the molecule, the molar ratio of b1) to b2) ranging from 0.7:1 to 10:1. The polymer according to the invention has a balanced property profile as regards absorptivity, gel strength, absorption speed and extractable componenents and can be advantageously produced by a continuous method.Type: GrantFiled: October 17, 2001Date of Patent: July 1, 2008Assignee: BASF AktiengesellschaftInventors: Wilfried Heide, Stefan Wickel, Thomas Daniel, Uwe Stüven
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Patent number: 7307132Abstract: This invention relates to a process for preparing a low-odor hydrogel-forming acrylic acid polymer, which comprises the steps of: a) preparing a polymeric hydrogel by free-radically polymerizing a monomer composition comprising at least 50% by weight of acrylic acid in an aqueous polymerization medium and converting said hydrogel into a particulate hydrogel or into hydrogel-forming powder; and optionally b) treating said particulate hydrogel or said hydrogel-forming powder with a crosslinking substance which, actually or latently, contain at least two functional groups capable of reacting with the carboxyl groups on the addition polymer; characterized by the acrylic acid used in step a) containing less than 400 ppm of acetic acid and propionic acid. It further relates to the hydrogel-forming addition polymers obtainable by the process and to their use.Type: GrantFiled: May 12, 2003Date of Patent: December 11, 2007Assignee: BASF AktiengesellschaftInventors: Gerhard Nestler, Klaus Joachim Mueller-Engel, Stefan Wickel
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Patent number: 7250481Abstract: Unsaturated acids are esterified with polyalcohols. The resulting reaction mixtures have utility.Type: GrantFiled: June 6, 2003Date of Patent: July 31, 2007Assignee: BASF AktiengesellschaftInventors: Thomas Jaworek, Thomas Daniel, Lothar Wolf, Rainer Koeniger, Reinhold Schwalm, Gabriele Hartmann, Stefan Wickel
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Publication number: 20060036043Abstract: The present invention relates to a process for preparing a low-odor hydrogel-forming acrylic acid polymer, which comprises the steps of: a) preparing a polymeric hydrogel by free-radically polymerizing a monomer composition comprising at least 50% by weight of acrylic acid in an aqueous polymerization medium and converting said hydrogel into a particulate hydrogel or into hydrogel-forming powder; and optionally b) treating said particulate hydrogel or said hydrogel-forming powder with a crosslinking substance which, actually or latently, contain at least two functional groups capable of reacting with the carboxyl groups on the addition polymer; characterized by the acrylic acid used in step a) having a total acrylic acid oligomer content of less than 500 ppm, preferably not more than 400 ppm and especially not more than 300 ppm. Here and hereinafter, all ppm units are by weight based on acrylic acid.Type: ApplicationFiled: December 8, 2003Publication date: February 16, 2006Applicant: Basf AktiengesellschaftInventors: Gerhard Nestler, Klaus Muller-Engel, Stefan Wickel
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Publication number: 20050209411Abstract: This invention relates to a process for preparing a low-odor hydrogel-forming acrylic acid polymer, which comprises the steps of: a) preparing a polymeric hydrogel by free-radically polymerizing a monomer composition comprising at least 50% by weight of acrylic acid in an aqueous polymerization medium and converting said hydrogel into a particulate hydrogel or into hydrogel-forming powder; and optionally b) treating said particulate hydrogel or said hydrogel-forming powder with a crosslinking substance which, actually or latently, contain at least two functional groups capable of reacting with the carboxyl groups on the addition polymer; characterized by the acrylic acid used in step a) containing less than 400 ppm of acetic acid and propionic acid. It further relates to the hydrogel-forming addition polymers obtainable by the process and to their use.Type: ApplicationFiled: May 12, 2003Publication date: September 22, 2005Applicant: BASF AktiengesellschaftInventors: Gerhard Nestler, Klaus Muller-Engel, Stefan Wickel
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Publication number: 20050176910Abstract: Unsaturated acids are esterified with polyalcohols. The resulting reaction mixtures have utility.Type: ApplicationFiled: June 6, 2003Publication date: August 11, 2005Applicant: BASF AktiengesellschaftInventors: Thomas Jaworek, Thomas Daniel, Lothar Wolf, Rainer Koniger, Reinhold Schwalm, Gabriele Hartmann, Stefan Wickel
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Publication number: 20050013865Abstract: The present invention relates to novel tocopherol-containing superabsorbents, to a process for preparing them using tocopherol-containing acid-functional monomers, especially acrylic acid, and to their use for absorbing aqueous fluids.Type: ApplicationFiled: December 18, 2002Publication date: January 20, 2005Inventors: Gerhard Nestler, Jurgen Schroder, Stefan Wickel
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Publication number: 20040186229Abstract: A process for continuous production of crosslinked fine particles of polymer gel by copolymerizingType: ApplicationFiled: January 28, 2004Publication date: September 23, 2004Applicant: BASF AktiengesellschaftInventors: Wilfried Heide, Stefan Wickel, Thomas Daniel, Joachim Nilges, Jurgen Hofmann
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Patent number: 6710141Abstract: A process for continuous production of crosslinked fine particles of polymer gel by copolymerizing a) water-soluble monoethylenically unsaturated monomers, b) from 0.001 to 5 mol % based on the monomers (a) of monomers containing at least two ethylenically unsaturated double bonds, and c) from 0 to 20 mol % based on the monomers (a) of water-insoluble monoethylenically unsaturated monomers in from 20 to 80% by weight aqueous solution in the presence of an initiator at from 0 to 140° C.Type: GrantFiled: May 8, 2002Date of Patent: March 23, 2004Assignee: BASF AktiengesellschaftInventors: Wilfried Heide, Stefan Wickel, Thomas Daniel, Joachim Nilges, Jürgen Hofmann
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Publication number: 20040014901Abstract: The invention relates to a cross-linked, water-swellable polymer that contains polymerized into it moieties of a) water-soluble, monoethylenically unsaturated monomers, and b) 0.001 to 5 mole % based on the monomers a) of a cross-linking combination, b1) a first cross-linking agent with at least two (meth)acrylic ester moieties in the molecule and b2) a second cross-linking agent with at least two (meth)allyloxy moieties in the molecule, the molar ratio of b1) to b2) ranging from 0.7:1 to 10:1. The polymer according to the invention has a balanced property profile as regards absorptivity, gel strength, absorption speed and extractable components and can be advantageously produced by a continuous method.Type: ApplicationFiled: August 8, 2003Publication date: January 22, 2004Inventors: Wilfried Heide, Stefan Wickel, Thomas Daniel, Uwe Stuven
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Patent number: 5258473Abstract: Finely divided, water-soluble polymers are prepared by polymerization of water-soluble, monoethylenically unsaturated monomers in not less than 20% strength by weight aqueous solution in the presence of a polymerization initiator in a kneader by a process in which from 0.1 to 10% by weight, based on the total monomers, of a surfactant are used in the polymerization, the polymerization initially being carried out to a conversion of the monomers of not less than 60% in the absence of the surfactant or in the presence of not more than 50% of the amount of surfactant, and the remaining amount of surfactant then being added to the reaction mixture and the polymerization completed. The addition of surfactant causes the polymer gel to disintegrate with formation of fine particles.Type: GrantFiled: March 1, 1991Date of Patent: November 2, 1993Assignee: BASF AktiengesellschaftInventors: Manfred Niessner, Stefan Wickel, Walter Schneider, Juergen Beck, Heinrich Hartmann, Thomas Meyer
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Patent number: 5180804Abstract: The water absorption capacity of crosslinked, water-swellable polymers is improved by a process in which a water-containing, finely divided polymer gel having a solids content of from 20 to 65% by weight is treated with steam at not less than 50.degree. C., the solids content of the water-containing polymer gel increasing by not more than 30% by weight, and the polymer gel is then dried in a conventional manner.Type: GrantFiled: August 8, 1990Date of Patent: January 19, 1993Assignee: BASF AktiengesellschaftInventors: Manfred Niessner, Juergen Beck, Heinrich Hartmann, Andreas H. Kemna, Stefan Wickel
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Patent number: 5149750Abstract: Finely divided, gel-like, water-swellable copolymers are prepared by copolymerizing(a) 100 parts by weight of water-soluble, monoethylenically unsaturated monomers,(b) from 0.01 to 5 parts by weight of monomers containing two or more ethylenically unsaturated double bonds and(c) from 0 to 20 parts by weight of water-insoluble, monoethylenically unsaturated monomersin 20-80% strength by weight aqueous solution in the presence of a polymerization initiator and from 0.1 to 10% by weight, based on the monomers used in the copolymerization, of a surfactant, by a process in which the monomers are copolymerized in the presence of initially from 0 to 50% by weight of the amount of surfactant to a conversion of not less than 60%, the remaining amount of surfactant is then added to the reaction mixture and the copolymerization is completed and the resulting gel particles dried.Type: GrantFiled: November 20, 1989Date of Patent: September 22, 1992Assignee: BASF AktiengesellschaftInventors: Manfred Niessner, Stefan Wickel, Wilfried Heide, Heinrich Hartmann