Patents by Inventor Alfons Landscheidt

Alfons Landscheidt 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).

  • Patent number: 6228964
    Abstract: A water-soluble, powdered, cationic polyelectrolyte comprising a copolymer of acrylamide and dimethylaminopropylacrylamide which is essentially free of bifunctional compounds and in which a) the dimethylaminopropylacrylamide is quaternized; b) the quotient of the intrinsic viscosity of the copolymers divided by the molar ratio of acrylamide to dimethylaminopropylacrylamide is greater than 200; and c) the proportion of the cationic monomers in the polymer is between 4 and 80 mol-%, the copolymer having been obtained by copolymerization of acrylamide and quaternized dimethylaminopropylacrylamide said quaternized dimethylaminopropylacrylamide having been obtained by the reaction of dimethylaminopropylacrylamide with a quaternizing agent in the absence of acrylamide.
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: May 8, 2001
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventors: Hans-Georg Hartan, Alfons Landscheidt
  • Patent number: 5512646
    Abstract: A water-soluble, powdered, cationic polyelectrolyte comprising a copolymer of acrylamide and dimethylaminopropylacrylamide in whicha) the dimethylaminopropylacrylamide is neutralized with mineral acids;b) the quotient of the intrinsic viscosity of the copolymers divided by the molar ratio of acrylamide to dimethylaminopropylacrylamide is greater than 200; andc) the proportion of the cationic monomers in the polymer is between 4 and 80 mol-%,the copolymer having been obtained by copolymerization of acrylamide and dimethylaminopropylacrylamide that is essentially free of bifunctional compounds.
    Type: Grant
    Filed: September 13, 1993
    Date of Patent: April 30, 1996
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventors: Hans-Georg Hartan, Alfons Landscheidt
  • Patent number: 5297740
    Abstract: The invention relates to a process for producing polyacrylic acids and copolymers of acrylic acid with up to 50 mol-% of comonomers. These compounds have a molecular weight of less than 100,000, measured at a pH-value of 8, and 10 to 60 mol-% are neutralized with calcium hydroxide. The invention also relates to the use of these products as grinding and dispersing aids for calcium carbonate.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: March 29, 1994
    Inventors: Alfons Landscheidt, Andreas Gebauer
  • Patent number: 5292404
    Abstract: The present invention relates to a process for trash removal or pitch control in the paper manufacture, in which process as agent for the trash removal or pitch control cationic groups containing polymers of 50 to 100%-wt. quaternized dimethylaminopropylmethacrylamide or dimethylaminopropylmethacrylamide and 0 to 50%-wt acrylamide, acrylic acid, methacrylic acid, acrylamidomethylpropanesulfonic acid, are used, which polymers have an intrinsic viscosity of smaller than 150 ml/g. The trash removal or pitch control agent is added to the pulp flow and/or the circuit water in amounts of up to 1%-wt., relative to the dry weight of the paper manufactured.
    Type: Grant
    Filed: March 27, 1992
    Date of Patent: March 8, 1994
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventors: Hans-Georg Hartan, Alfons Landscheidt
  • Patent number: 5241011
    Abstract: The invention relates to a process for producing polyacrylic acids and copolymers of acrylic acid with up to 50 mol-% of comonomers. These compounds have a molecular weight of less than 100,000, measured at a pH-value of 8, and 10 to 60 mol-% are neutralized with calcium hydroxide. The invention also relates to the use of these products as grinding and dispersing aids for calcium carbonate.
    Type: Grant
    Filed: August 7, 1992
    Date of Patent: August 31, 1993
    Inventors: Alfons Landscheidt, Andreas Gebauer
  • Patent number: 5176797
    Abstract: The present invention relates to amphoteric water soluble polymers which containa) 90 to 30%-wt acrylic acid and/or methacrylic acidb) 10 to 60%-wt of a compound of the formula ##STR1## wherein R.sub.1 stands for hydrogen or the methyl radical, R.sub.2 and R.sub.3, which are the same or different, stand for the methyl or ethyl radical, and an optionally branched alkaline radical with 1 to 5 C atoms stands for Xand optionally, up to 50%-wt of acrylamidomethylpropane sulfonic acid and up to 10%-wt of a further ethylenically unsaturated compound, the molecular weight of these polymers, measured at a pH value of 8.0, being smaller than 100,000. The present invention also relates to the process for producing these polymers, and their use as grinding or dispersing agents for the production of highly concentrated aqueous pigment suspensions.
    Type: Grant
    Filed: May 13, 1991
    Date of Patent: January 5, 1993
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventors: Hans-Georg Hartan, Alfons Landscheidt
  • Patent number: 4980437
    Abstract: The present invention relates to a process to improve the organoleptic behavior and the physical characteristics of leather by the use of aqueous solutions of copolymers of 90 to 20%-wt acrylic acid or methyacrylic acid, as well as 10 to 80%-wt of a monomer of the formula ##STR1## wherein R.sub.1 is hydrogen or methyl; R.sub.2 and R.sub.3, which are equal or different, are methyl or ethyl; x stands for an optionally branched alkylene radical with 1 to 5 carbon atoms; the amine nitrogen is optionally neutralized or quaternized; and the molecular weight of the copolymer, measured at a pH of 8.0, is less than 100,000. The concentration of the copolymer in the aqueous solution is 0.02 to 10%-wt, relative to the shaved weight of the leather.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: December 25, 1990
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventors: Manfred Kaussen, Dolf Stockhausen, Hans-Georg Hartan, Alfons Landscheidt
  • Patent number: 4813968
    Abstract: The present invention relates to a process to improve the organoleptic behaviour and the physical characteristics of leather by the use of aqueous solutions of copolymers of 90 to 20%-wt acrylic acid or methyacrylic acid, as well as 10 to 80%-wt of a monomer of the formula ##STR1## wherein R.sub.1 is hydrogen or methyl; R.sub.2 and R.sub.3, which are equal or different, are methyl or ethyl; x stands for an optionally branched alkylene radical with 1 to 5 carbon atoms; the amine nitrogen is optionally neutralized or quaternized; and the molecular weight of the copolymer, measured at a pH of 8.0, is less than 100,000. The concentration of the copolymer in the aqueous solution is 0.02 to 10%-wt, relative to the shaved weight of the leather.
    Type: Grant
    Filed: January 20, 1988
    Date of Patent: March 21, 1989
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventors: Manfred Kaussen, Dolf Stockhausen, Hans-Georg Hartan, Alfons Landscheidt
  • Patent number: 4605740
    Abstract: The present invention relates to a process for the production of N-substituted acrylic acid amides by conversion of 2-carboalkoxy-t-oxabicyclo(2,2,1)hept-5-enes with primary or secondary amines to 2-carboxamide-7-oxabicyclo(2,2,1)hept-5-enes and the thermal decomposition of the latter, preferably in the presence of Lewis acids and in a vacuum, to furane and N-substituted acrylic acid amides. The process according to the invention results in high purity N-substituted acrylic acid amides that are, in the main, free of bifunctional monomers which would disrupt the subsequent polymerization of the N-substituted acrylic acid amides by undesired cross-linking.
    Type: Grant
    Filed: September 22, 1983
    Date of Patent: August 12, 1986
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventor: Alfons Landscheidt
  • Patent number: 4555581
    Abstract: The invention relates to a process for the production of 7-oxabicyclo-(2,2,1)hept-5-ene derivatives by conversion of acrylic acid esters and furanes in the presence of catalytic quantities of a Lewis acid. By use of Lewis acid, the reaction time is greatly reduced with good results in terms of product purity by comparison with known processes. The reaction products are intermediates, e.g. in the production of N-substituted acrylic acid amides.
    Type: Grant
    Filed: September 22, 1983
    Date of Patent: November 26, 1985
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventor: Alfons Landscheidt