Patents by Inventor Gunter Siegemund

Gunter Siegemund 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: 6288293
    Abstract: The invention relates to a process for the preparation of 1,1,1,2-tetrafluoroethane from 1,1,1-trifluoro-2-chloroethane and hydrogen fluoride in the gas phase, in which a catalyst containing chromium and magnesium is used which is obtainable by precipitating chromium(III) hydroxide by reacting 1 mol of a water-soluble chromium(III) salt with at least 1.5 mol of magnesium hydroxide or magnesium oxide in the presence of water, the reaction mixture is made into a paste containing chromium hydroxide and a magnesium salt, and the paste is then dried and treated with hydrogen fluoride at temperatures of 20 to 500° C.
    Type: Grant
    Filed: June 21, 1993
    Date of Patent: September 11, 2001
    Assignee: Solvay (Societe Anonyme)
    Inventors: Wolfgang Wanzke, G√ľnter Siegemund, Wilfried Schmieder
  • Patent number: 5969199
    Abstract: The invention relates to a process for the addition of HF to halogenated alkenes by reacting these with at least one hydrofluoride of the formula [B.cndot.n HF], in which B is an organic nitrogen base and n is an integer or fraction .ltoreq.4, it being intended that the reaction of perfluoroiso-butene CF.sub.2 =C(CF.sub.3).sub.2 is excluded.
    Type: Grant
    Filed: June 8, 1998
    Date of Patent: October 19, 1999
    Assignee: Solvay S.A.
    Inventors: Raimund Franz, Gunter Siegemund
  • Patent number: 5847245
    Abstract: The invention relates to a process for the addition of HF to halogenated alkenes by reacting these with at least one hydrofluoride of the formula ?B.n HF!, in which B is an organic nitrogen base and n is an integer or fraction .ltoreq.4, it being intended that the reaction of perfluoroisobutene CF.sub.2 .dbd.C(CF.sub.3).sub.2 is excluded.
    Type: Grant
    Filed: October 9, 1996
    Date of Patent: December 8, 1998
    Assignee: Solvay (Societe Anonyme)
    Inventors: Raimund Franz, Gunter Siegemund
  • Patent number: 5739070
    Abstract: Process for regenerating a fluorination catalyst The invention relates to a process for regenerating a fluorination catalyst containing chromium and magnesium after use in a fluorination reaction, in which the used catalyst is treated with a mixture comprising at least 10 mol % of HF, from 30 to 90 mol % of O.sub.2 and from 0 to 60 mol % of inert gas.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: April 14, 1998
    Assignee: Solvay (Societe Anonyme)
    Inventors: Frank Ebmeyer, Ralf Finzel, Gunter Siegemund, Wolfgang Wanzke
  • Patent number: 5728884
    Abstract: The invention relates to a process for the work-up of a liquid complex hydrofluoride of a tertiary amine of the formula (I) ?R.sup.1 R.sup.2 R.sup.3 N.multidot.n HF!, where the radicals R.sup.1, R.sup.2 and R.sup.3 are C.sub.1 -C.sub.8 -alkyl groups which together have at least 7 carbon atoms and n is an integer or fractional number where 1.5<n<3, which, for the purpose of molecular addition of HF to a halogenated alkene, is reacted with the latter. In the reaction of the halogenated alkene with the complex amine hydrofluoride of the formula (I), the molar ratio HF:R.sup.1 R.sup.2 R.sup.3 N is allowed to fall until amine separates out as a further liquid phase, and the amine is separated off.
    Type: Grant
    Filed: December 18, 1995
    Date of Patent: March 17, 1998
    Assignee: Solvay
    Inventors: Ulrich Hahn, Raimund Franz, Gunter Siegemund
  • Patent number: 5684193
    Abstract: The invention relates to a process for the preparation of perfluoropropionyl fluoride (II) by the isomerization of hexafluoropropene oxide (I): ##STR1## wherein the reaction medium used is a liquid complex ammonium hydrofluoride.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: November 4, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Gunter Siegemund, Raimund Franz
  • Patent number: 5672748
    Abstract: The invention relates to the preparation of trifluoroacetyl fluoride by reacting trichloroacetyl chloride with anhydrous hydrogen fluoride in the gaseous phase on a catalyst which is obtainable by reacting a water-soluble chromium (III) salt with magnesium hydroxide or magnesium oxide in the presence of water, converting the reaction mixture into a paste, drying the paste and treating it with hydrogen fluoride.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: September 30, 1997
    Assignee: Solvay
    Inventors: Frank Ebmeyer, Tobias Metzenthin, Gunter Siegemund
  • Patent number: 5659078
    Abstract: The invention relates to a process for the preparation of trichloroacetyl chloride by reaction of acetyl chloride or acetaldehyde or chlorinated derivatives thereof with chlorine in the presence of active charcoal as the catalyst.
    Type: Grant
    Filed: July 31, 1995
    Date of Patent: August 19, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Frank Ebmeyer, Tobias Metzenthin, Gunter Siegemund
  • Patent number: 5534634
    Abstract: Process for preparing trifluoroethyl sulfur compounds from thiolates and 1-chloro-2,2,2-trifluoroethane. The invention relates to the preparation of trifluoroethyl sulfur compounds of the formula RSCH.sub.2 CF.sub.3 by reacting 1-chloro-2,2,2-trifluoroethane CH.sub.2 Cl--CF.sub.3 in a polar aprotic solvent with salts of thiols of the formula RSH, where R can be an alkyl or aryl radical or a heterocyclic radical.
    Type: Grant
    Filed: September 29, 1994
    Date of Patent: July 9, 1996
    Assignee: Hoechst AG
    Inventors: Wolfgang Appel, Frank Ebmeyer, Tobias Metzenthin, Gunter Siegemund
  • Patent number: 5471002
    Abstract: A process for preparing trifluoromethylanilines of the formula (I), ##STR1## in which R.sup.1 and R.sup.2, independently of each other, are hydrogen, halogen, (C.sub.1 -C.sub.4) alkyl, hydroxyl, alkoxy, alkylthio, carboxyl, or a nitro or cyano group, by reacting compounds of the formula (II) ##STR2## in which X.sub.1, X.sub.2 and X.sub.3 are in each case, identically or differently, halogen atoms,a is 0 or 1,Y is fluorine, chlorine or bromine, andR.sup.1 and R.sup.2 have the defined meaning, with anhydrous hydrofluoric acid, and converting the resulting aniline hydrofluorides with a base into the free amines.
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: November 28, 1995
    Inventors: Wolfgang Appel, Gunter Siegemund
  • Patent number: 5399795
    Abstract: The invention relates to a process for the preparation of 2-H-heptafluoropropane, wherein hexafluoropropene is reacted with hydrogen fluoride in the presence of a weakly basic ion exchanger whose reactive centers comprise tertiary amino groups.
    Type: Grant
    Filed: July 12, 1994
    Date of Patent: March 21, 1995
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Raimund Franz, Gunter Siegemund
  • Patent number: 5319131
    Abstract: Esters of .alpha.-fluoroacrylic acid are accessible by hydrolysis of an .alpha.-hydroxymethyl-.alpha.-fluoromalonic acid ester, decarboxylation and dehydration of the hydrolysis product and subsequent esterification of the resulting .alpha.-fluoroacrylic acid with an alcohol. The esters are polymerizable and are suitable for use as a starting material for preparing fluoropolymers which in turn are usable as materials for manufacturing transparent articles. The polymers are high-molecular and non-crystalline and have softening temperatures of above 100.degree. C.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: June 7, 1994
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Rudolf Heumuller, Gunter Siegemund, Werner Groh, Gerhard Wieners, Peter Herbrechtsmeier
  • Patent number: 5288908
    Abstract: Compounds of the formula ##STR1## in which X represents hydrogen, --NO.sub.2 or --NH.sub.2 and Y represents --CH.sub.3, --COOH, --CONH.sub.2, --NH.sub.2 or --N.dbd.N--Z, in which the group --Z is ##STR2## with the proviso that if Y represents the group --N.dbd.N--Z, X is only --NO.sub.2, and if Y represents the group --CH.sub.3, X is only hydrogen, are described. A compound of the formula ##STR3## the preparation of which in a multi-stage process, in which the compounds of the general formula (I) are also obtained, is described, is preferred.The resulting 3,4'-diamino compound is suitable for the preparation of polycondensates and shaped articles, films and fibers of high heat resistance.
    Type: Grant
    Filed: July 19, 1993
    Date of Patent: February 22, 1994
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Jurgen Lau, Gunter Siegemund, Freimund Rohrscheid
  • Patent number: 5274126
    Abstract: A compound of the formula ##STR1## and the dianhydride thereof are prepared by air oxidation in the presence of a catalyst mixture composed of at least 2 heavy metal salts and also bromine in an acid organic medium. The compounds can be employed for the preparation of partially fluorinated polycondensates, such as polyimides, polycarboxamides, esters of polyamidecarboxylic acids, polyamides and imide-oligomers.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: December 28, 1993
    Assignee: Hoechst AG
    Inventors: Freimund Rohrscheid, Wolfgang Appel, Gunter Siegemund
  • Patent number: 5266668
    Abstract: Certain esters of .alpha.-fluoroacrylic acid are accessible by hydrolyzing .alpha.-hydroxymethyl .alpha.-fluoromalonic acid esters and subsequently decarboxylating the hydrolysis product. The phenyl .alpha.-fluoroacrylates which are substituted on the phenyl radical can be prepared by hydroxymethylating dimethyl .alpha.-fluoromalonate, decarboxylating and dehydrating the resuiting dimethyl .alpha.-hydroxymethyl-.alpha.-fluoromalonate and esterifying the resuiting .alpha.-fluoroacrylic acid with substituted phenols. The substituted phenyl .alpha.-fluoroacrylates are colorless liquids or colorless solids which can be polymerized. They are suitable for use as a starting material for the preparation of fluorine polymers.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: November 30, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Rudolf Heumuller, Peter Herbrechtsmeier, Gunter Siegemund, Werner Groh
  • Patent number: 5254771
    Abstract: The invention relates to a process for the preparation of 1,1,1-trifluoro-2,2-dichloroethane by chlorinating 1,1,1-trifluoro-2-chloroethane, in which the chlorination is carried out under an elevated pressure. The pressure is preferably 10 to 400 bar, particularly 50 to 250 bar. If the reaction is initiated by heat, it is preferably carried out at 200.degree. to 300.degree. C. If it is initiated by a free-radical starter, the reaction is preferably carried out at 150.degree. to 250.degree. C.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: October 19, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hans R. Cremer, Gunter Siegemund, Wilhelm Lendle
  • Patent number: 5202469
    Abstract: Partially fluorinated dicarboxylic acid and the acid chloride thereof, a process for its preparation and its use.The compound of the formula (I) ##STR1## and the acid chloride thereof are prepared by air oxidation in the presence of a catalyst mixture composed of the ions of cobalt, manganese and bromine in an acid organic medium. The compounds can be used for the preparation of linear polycarboxamides and polycarboxylic acid esters.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: April 13, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Freimund Rohrscheid, Wolfgang Appel, Gunter Siegemund
  • Patent number: 5198925
    Abstract: Esters of .alpha.-fluoroacrylic acid are accessible by hydrolysis of an .alpha.-hydroxymethyl-.alpha.-fluoromalonic acid ester, decarboxylation and dehydration of the hydrolysis product and subsequent esterification of the resulting .alpha.-fluoroacrylic acid with an alcohol. The esters are polymerizable and are suitable for use as a starting material for preparing fluoropolymers which in turn are usable as materials for manufacturing transparent articles. The polymers are high-molecular and non-crystalline and have softening temperatures of above 100.degree. C.
    Type: Grant
    Filed: February 18, 1992
    Date of Patent: March 30, 1993
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Rudolf Heumuller, Gunter Siegemund, Werner Groh, Gerhard Wieners, Peter Herbrechtsmeier
  • Patent number: 5157172
    Abstract: The invention relates to a process for the preparation of 1,1,1-trifluoro-2-chloroethane from trichloroethene and hydrogen fluoride in the gas phase. In this process a catalyst containing chromium and magnesium is used, which catalyst is obtainable by precipitating chromium(III) hydroxide by reacting 1 mole of a water-soluble chromium(III) salt with at least 1.5 mol of magnesium hydroxide or magnesium oxide in the presence of water, converting the reaction mixture into a paste containing chromium hydroxide and a magnesium salt and then drying the paste and treating it at temperatures of 20.degree. to 500.degree. C. with hydrogen fluoride.
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: October 20, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wolfgang Wanzke, Gunter Siegemund, Thomas Muller
  • Patent number: 5153334
    Abstract: Partially fluorinated tetracarboxylic acid and the dianhydride thereof, a process for their preparation and their useA compound of the formula ##STR1## and the dianhydride thereof are prepared by air oxidation in the presence of a catalyst mixture composed of at least 2 heavy metal salts and also bromine in an acid organic medium. The compounds can be employed for the preparation of partially fluorinated polycondensates, such as polyimides, polycarboxamides, esters of polyamidecarboxylic acids, polyamides and imide-oligomers.
    Type: Grant
    Filed: June 20, 1991
    Date of Patent: October 6, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Freimund Rohrscheid, Wolfgang Appel, Gunter Siegemund