Patents Assigned to Suddeutsche Kalkstickstoff-Werke
  • Patent number: 4296089
    Abstract: The invention provides inorganic fibers based on calcium sulfate dihydrate or calcium sulfate aluminate hydrate (or their dehydration products), wherein the ratio of average length to diameter of the fibers is more than 100:1 and the length of the fibers is at least 0.2 mm; preferably the ratio of average length to diameter is 300-800:1, and the length is 0.5-6 mm.
    Type: Grant
    Filed: February 28, 1979
    Date of Patent: October 20, 1981
    Assignee: Suddeutsche Kalkstickstoff-Werke
    Inventors: Alois Aignesberger, Walter Lukas, Ekkehard Weinberg
  • Patent number: 4270954
    Abstract: The invention provides inorganic fibers based on calcium sulfate dihydrate or calcium sulfate aluminate hydrate (or their dehydration products), wherein the ratio of average length to diameter of the fibers is more than 100:1 and the length of the fibers is at least 0.2 mm; preferably the ratio of average length to diameter is 300-800:1, and the length is 0.5-6 mm.
    Type: Grant
    Filed: April 28, 1977
    Date of Patent: June 2, 1981
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventors: Alois Aignesberger, Walter Lukas, Ekkehard Weinberg
  • Patent number: 4159906
    Abstract: Molten metals, especially molten pig iron, are desulfurized by contacting them with a composition comprising calcium carbide or calcium cyanamide and an additive agent yielding water or hydrogen at the temperature of the molten metal; preferred as the additive agents are the alkali metal hydrides, polyethylene or polyamide for yielding hydrogen and hydrate of lime and alkaline earth borates for yielding water.
    Type: Grant
    Filed: May 18, 1977
    Date of Patent: July 3, 1979
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventors: Walter Meichsner, Heinrich Rock, Alfred Freissmuth, Horst Prietzel, Heinrich Rellermeyer, Wolfgang Ullrich, Erich Pfluger, Raymund Sindermann
  • Patent number: 4154606
    Abstract: Finely granular desulfurizing agents for iron melts, consisting of at least one alkaline earth metal carbonate and at least one reducing metal carbide and optionally a reducing metal or an alloy thereof, are outstandingly effective in desulfurizing action and, based on the high degree of utilization of said agent, increase the amount of slag formed only to a negligible degree.
    Type: Grant
    Filed: February 28, 1978
    Date of Patent: May 15, 1979
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventors: Alfred Freissmuth, Werner Gmohling, Walter Meichsner, Heinrich Rock
  • Patent number: 4126470
    Abstract: A light concrete prepared from a mixture of Portland cement, cellular aggregate, and an admixture including a melamine-formaldehyde condensate carrying sulfo groups for reducing the need for mixing water, an alkaline earth metal stearate as a water repelling material, and polyethyleneglycol has greater mechanical strength at lower density than an otherwise identical concrete containing only two ingredients of the admixture.
    Type: Grant
    Filed: September 12, 1977
    Date of Patent: November 21, 1978
    Assignees: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft, Societe Auxiliaire d'Entreprises
    Inventors: Hans-Rudiger Braun, Hans-Gunter Rosenbauer, Andre Coin, Roland Davril
  • Patent number: 4126664
    Abstract: The storage stability of strong or concentrated, aqueous solutions of cyanamide, even those conventionally stabilized with acid, is enhanced by small amounts of lower alkyl esters of carboxylic acids having preferably a pK.sub.a.sup.25.degree. value of 3.8 or less.
    Type: Grant
    Filed: September 1, 1977
    Date of Patent: November 21, 1978
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventor: Stefan Weiss
  • Patent number: 4078915
    Abstract: Molten metals, especially molten pig iron, are desulfurized by contacting them with a composition comprising calcium carbide or calcium cyanamide and an additive agent yielding water or hydrogen at the temperature of the molten metal; preferred as the additive agents are the alkali metal hydrides, polyethylene or polyamide for yielding hydrogen and hydrate of lime and alkaline earth borates for yielding water.
    Type: Grant
    Filed: October 23, 1973
    Date of Patent: March 14, 1978
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventors: Walter Meichsner, Heinrich Rock, Alfred Freissmuth, Horst Prietzel, Heinrich Rellermeyer, Wolfgang Ullrich, Erich Pfluger, Raymund Sindermann
  • Patent number: 4069383
    Abstract: Melamine is prepared from cyanamide and/or dicyandiamide by contacting the cyanamide and/or dicyandiamide at approximately atmospheric pressure in an organic solvent at 100.degree. to 250.degree. C with at least one solvent selected from the group having the formulas ##STR1## wherein R.sub.1 and R.sub.2 are alkyl which may be joined together to form an alkylene ring,In the simultaneous presence of alkali hydroxide or alkaline earth hydroxide.
    Type: Grant
    Filed: August 17, 1976
    Date of Patent: January 17, 1978
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventors: Horst Michaud, Gunter Ortenburger, Wilhelm Poschinger, Heinrich Rock, Josef Seeholzer
  • Patent number: 4054601
    Abstract: Pure glycolic acid is recovered practically completely from the product obtained by hydrolysis of glycolonitrile containing at least stoichiometrically equivalent amounts of ammonium and sulfate ions by extraction with a mixture of a trialkyl phosphate and a dialkylether, preferably of equal weights of tributyl phosphate and diisopropyl ether, and separation of the glycolic acid from the extraction medium by contact with water.
    Type: Grant
    Filed: June 22, 1976
    Date of Patent: October 18, 1977
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventors: Ulrich Metz, Horst Michaud
  • Patent number: 4049442
    Abstract: Iron melts, particularly iron melts made by the torpedo ladle method, can be efficiently desulfurized by adding thereto a mixture of calcium carbide and diamide lime wherein the content of diamide lime is from 40 to 70% by weight of the desulfurizing composition.
    Type: Grant
    Filed: January 6, 1976
    Date of Patent: September 20, 1977
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventors: Alfred Freissmuth, Walter Heinl, Herbert Knahl, Erich Pfluger
  • Patent number: 3985696
    Abstract: Aqueous solutions of melamine-formaldehyde and melamine-urea-formaldehyde condensation products having anionic sulfo groups in concentrations as high as 50% by weight may be prepared in a three-stage process. In the first stage, melamine or a mixture of melamine with up to 40 mole-% urea, formaldehyde, and an alkali metal sulfite are condensed in aqueous solution at 60.degree.-80.degree.C and pH 10-13 until the solution is free from readily detectable amounts of sulfite. In the second stage, condensation is continued at pH 3.0-4.5 for 30 to 90 minutes. In the third stage, a temperature of 70.degree. to 95.degree.C and a pH of 7.5 to 9.0 are maintained until a sample of the solution, when diluted to 20% solids by weight, has a viscosity of 5 to 40 centipoises at 20.degree.C.
    Type: Grant
    Filed: November 14, 1974
    Date of Patent: October 12, 1976
    Assignee: Suddeutsche Kalkstickstoff-Werke AG
    Inventors: Alois Aignesberger, Paul Bornmann, Hans-Gunter Rosenbauer, Hans Theissig
  • Patent number: 3941734
    Abstract: The aqueous melamine resin solutions prepared according to the process of U.S. Pat. No. 2,730,516 by sequential condensation of a sulfite bearing, aqueous solution of melamine and formaldehyde at alkaline and acid pH and subsequent neutralization is stabilized by preliminary condensation of the melamine and formaldehyde prior to addition of the sulfite and by refluxing the ultimate condensation mixture at pH 8.5 for 1 hour or more. Concrete mixtures prepared with the stabilized resin solutions cure more rapidly.
    Type: Grant
    Filed: April 17, 1974
    Date of Patent: March 2, 1976
    Assignee: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft
    Inventors: Alois Aignesberger, Paul Bornmann
  • Patent number: 3933755
    Abstract: A thermosetting resin useful for attaching decorative paper facings to chipboard and like cellulosic panels is prepared by condensation of melamine with thiourea, formaldehyde, and a diol ether, up to one half by weight of the melamine being capable of being replaced by urea without seriously effecting the quality of the resin.
    Type: Grant
    Filed: May 22, 1974
    Date of Patent: January 20, 1976
    Assignee: Suddeutsche Kalkstickstoff-Werke AG
    Inventors: Horst Michaud, Josef Seeholzer, Ludwig Pentzel, Josefa Mangs
  • Patent number: 3931316
    Abstract: O-Methyl-isourea hydrogen sulfate is prepared from cyanamide, methanol, and sulfuric acid in a yield of better than 90% when crystalline cyanamide is added to a mixture of sulfuric acid and methanol containing 50 - 150 parts by weight methanol per part sulfuric acid and holding the resulting composition at -10.degree. to 20.degree.C. The recovered O-methyl-isourea hydrogen sulfate is further converted to O-methyl-isourea sulfate with yields greatly exceeding 50%, and even 80%, by holding a mixture of approximately equimolar amounts of cyanamide and of the hydrogen sulfate in a liquid medium essentially consisting of methanol at 5.degree. to 40.degree.C until the O-methyl-isourea sulfate is formed and can be recovered.
    Type: Grant
    Filed: December 18, 1974
    Date of Patent: January 6, 1976
    Assignee: Suddeutsche Kalkstickstoff-Werke AG
    Inventor: Stefan Weiss