Patents by Inventor Klaus Raab

Klaus Raab 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: 5756413
    Abstract: The present invention relates to a process for recovering the cobalt carbonyl catalyst used, in which a water-soluble cobalt salt is first prepared by addition of acid and this is subsequently precipitated as cobalt hydroxide. This cobalt hydroxide is then reacted with the N-acyl-.alpha.-amino acid derivative for whose preparation the cobalt carbonyl catalyst is intended, and the resulting cobalt-containing melt is converted into the cobalt carbonyl catalyst in the presence of a mixture of carbon monoxide and hydrogen.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: May 26, 1998
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Sandra Bogdanovic, Holger Geissler, Klaus Raab, Matthias Beller, Hartmut Fischer
  • Patent number: 5175380
    Abstract: Mixtures of perfluorinated alkyl bromides or alkylene dibromides containing perfluorinated iodine compounds are irradiated with electromagnetic radiation in the wavelength range from 230 to 500 nm and brought into contact, either during the irradiation or directly thereafter, with at least one of the following agents: active charcoal, certain finely divided metals, lower aliphatic alcohols, chlorine, bromine, oxygen, hydrogen peroxide, aqueous or alcoholic solutions of alkali metal compounds with certain inorganic anions or lower aliphatic alcohols. After removal of the agent and if appropriate distillation, products which contain less than 0.0005% by weight of iodine compounds and can be employed, for example, in the medical sector can be obtained.
    Type: Grant
    Filed: May 14, 1992
    Date of Patent: December 29, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Klaus Raab
  • Patent number: 5113026
    Abstract: A process for the preparation of substantially fluorinated alkyl bromides from the corresponding iodides is described. At least one anhydrous metal bromide, which can contain certain metals as the cation, is reacted at 80.degree. to 450.degree. C. under atmospheric pressure or the autogenous pressure of the reaction mixture and with good mixing, with the substantially fluorinated alkyl iodide, without the addition of other substances. The new process achieves good yields of substantially fluorinated alkyl bromides and requires no special safety precautions.
    Type: Grant
    Filed: June 11, 1991
    Date of Patent: May 12, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Klaus Raab
  • Patent number: 5073291
    Abstract: The invention relates to an azeotrope-type mixture which contains about 3-5% by weight of methanol and about 95-97% by weight of 1,4-dihydroperfluorobutane, and also to a process for cleaning electronic components, in particular soldered conductor boards or printed circuits, with the aid of said mixture.
    Type: Grant
    Filed: January 23, 1991
    Date of Patent: December 17, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Horst Robeck, Hans-Matthias Deger, Klaus Raab
  • Patent number: 5073651
    Abstract: A process for the preparation of extensively fluorinated alkyl bromides from the corresponding iodides is described in which, in a dipolar aprotic solvent, a bromide which is present as a salt of an alkali metal, alkaline earth metal, copper or substituted or unsubstituted amonium is reacted with an extensively fluorinated alkyl iodide at 120.degree. to 200.degree. C. The reaction can be carried out at -10.degree. to +120.degree. C., in some cases with improved yields if it is carried out in the presence of an alkali metal salt of at least one hydroxyalkanesulfinic acid having 1 to 5 carbon atoms. The novel process enables uncomplicated apparatuses to be used without particular safety measures and presents no corrosion problems.
    Type: Grant
    Filed: October 26, 1990
    Date of Patent: December 17, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Klaus Raab
  • Patent number: 4792613
    Abstract: Novel polyfluorinated cyclic carbonates of the formula ##STR1## in which R.sub.F is an unbranched or branched perfluoroalkyl radical having 1 to 18 carbon atoms, an unbranched or branched .omega.-hydro- or .omega.-haloperfluoroalkyl radical having 1 to 18 carbon atoms, or a cycloperfluoroalkyl radical having 4 to 6 carbon atoms, are described. They are prepared by reacting a polyfluorinated halohydrin of the formula R.sub.F --CH.sub.2 --CH(Hal)--CH.sub.2 OH, in which R.sub.f has the meaning mentioned and Hal represents a halogen, with carbonate or hydrogen carbonate compounds in the presence of an aprotic solvent. The novel compounds, which are generally solid and crystalline at room temperature, represent, in particular, good waterproofing and oil-proofing agents for textiles.
    Type: Grant
    Filed: July 2, 1987
    Date of Patent: December 20, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventor: Klaus Raab
  • Patent number: 4760205
    Abstract: New processes for the preparation of 2-iodo-perfluoro-2-methyl-butane and the corresponding -pentane are described. In one process, perfluoro-2-methyl-2-butene or the corresponding -pentene is reacted in an amount of at least 5 mol with a mixture of 2 mol of iodine and 1 mol of iodine pentafluoride in the presence of more than 1 mol of at least one fluoride of a metal of group I of the periodic table of the elements under the autogenous pressure of the reaction mixture at 170.degree. to 220.degree. C. for 2 to 30 hours. In another process, the same perfluoroolefins are reacted, as the starting substances, with iodine and an alkali metal fluoride in the presence of at least 1 mol of a soluble silver salt per mole of the perfluorinated olefin at 20.degree. to 100.degree. C. for 0.5 to 10 hours. After working up by distillation, the pure iodoperfluoroalkanes are obtained. They are suitable for numerous reactions, but in particular as a packing for lasers.
    Type: Grant
    Filed: December 31, 1986
    Date of Patent: July 26, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Anton Probst, Klaus Raab, Konrad von Werner
  • Patent number: 4754082
    Abstract: In a novel process for the preparation of perfluoroalkylalkenols, perfluoroalkylhalohydrins are dehydrohalogenated using specific ionic bases, namely using an alkali metal carbonate, an alkali metal hydrogen carbonate or an alkylammonium hydrogen carbonate, in the presence of aprotic and polar solvents. Using this process, high yields of the intended perfluoroalkylalkenols are achieved and only very small amounts, if any at all, of undesired byproducts, such as partially fluorinated ether alcohols and/or partially fluorinated epoxides, are formed.
    Type: Grant
    Filed: July 2, 1987
    Date of Patent: June 28, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Klaus Raab, Johanna Poschl