Patents Assigned to Suddeutsche Kalkstickstoff-Werke
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Patent number: 4296089Abstract: 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: GrantFiled: February 28, 1979Date of Patent: October 20, 1981Assignee: Suddeutsche Kalkstickstoff-WerkeInventors: Alois Aignesberger, Walter Lukas, Ekkehard Weinberg
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Patent number: 4270954Abstract: 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: GrantFiled: April 28, 1977Date of Patent: June 2, 1981Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventors: Alois Aignesberger, Walter Lukas, Ekkehard Weinberg
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Patent number: 4159906Abstract: 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: GrantFiled: May 18, 1977Date of Patent: July 3, 1979Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventors: Walter Meichsner, Heinrich Rock, Alfred Freissmuth, Horst Prietzel, Heinrich Rellermeyer, Wolfgang Ullrich, Erich Pfluger, Raymund Sindermann
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Patent number: 4154606Abstract: 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: GrantFiled: February 28, 1978Date of Patent: May 15, 1979Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventors: Alfred Freissmuth, Werner Gmohling, Walter Meichsner, Heinrich Rock
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Patent number: 4126470Abstract: 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: GrantFiled: September 12, 1977Date of Patent: November 21, 1978Assignees: Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft, Societe Auxiliaire d'EntreprisesInventors: Hans-Rudiger Braun, Hans-Gunter Rosenbauer, Andre Coin, Roland Davril
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Patent number: 4126664Abstract: 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: GrantFiled: September 1, 1977Date of Patent: November 21, 1978Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventor: Stefan Weiss
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Patent number: 4078915Abstract: 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: GrantFiled: October 23, 1973Date of Patent: March 14, 1978Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventors: Walter Meichsner, Heinrich Rock, Alfred Freissmuth, Horst Prietzel, Heinrich Rellermeyer, Wolfgang Ullrich, Erich Pfluger, Raymund Sindermann
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Patent number: 4069383Abstract: 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: GrantFiled: August 17, 1976Date of Patent: January 17, 1978Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventors: Horst Michaud, Gunter Ortenburger, Wilhelm Poschinger, Heinrich Rock, Josef Seeholzer
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Patent number: 4054601Abstract: 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: GrantFiled: June 22, 1976Date of Patent: October 18, 1977Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventors: Ulrich Metz, Horst Michaud
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Patent number: 4049442Abstract: 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: GrantFiled: January 6, 1976Date of Patent: September 20, 1977Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventors: Alfred Freissmuth, Walter Heinl, Herbert Knahl, Erich Pfluger
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Patent number: 3985696Abstract: 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: GrantFiled: November 14, 1974Date of Patent: October 12, 1976Assignee: Suddeutsche Kalkstickstoff-Werke AGInventors: Alois Aignesberger, Paul Bornmann, Hans-Gunter Rosenbauer, Hans Theissig
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Patent number: 3941734Abstract: 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: GrantFiled: April 17, 1974Date of Patent: March 2, 1976Assignee: Suddeutsche Kalkstickstoff-Werke AktiengesellschaftInventors: Alois Aignesberger, Paul Bornmann
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Melamine, formaldehyde, thiourea and diol ether thermosetting resin and method of preparing the same
Patent number: 3933755Abstract: 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: GrantFiled: May 22, 1974Date of Patent: January 20, 1976Assignee: Suddeutsche Kalkstickstoff-Werke AGInventors: Horst Michaud, Josef Seeholzer, Ludwig Pentzel, Josefa Mangs -
Patent number: 3931316Abstract: 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: GrantFiled: December 18, 1974Date of Patent: January 6, 1976Assignee: Suddeutsche Kalkstickstoff-Werke AGInventor: Stefan Weiss