Patents by Inventor Wilfried Niemeier

Wilfried Niemeier 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: 6037504
    Abstract: In a process for producing aliphatic .alpha.,.omega.-diols comprising 4 to 12 C atoms from aliphatic .alpha.,.omega.-dicarboxylic acids comprising 4 to 12 C atoms, an oligoester of average chain length n=3 to n=4.5 and with an acid number of 40 to 60 mg KOH/g reaction mixture is first formed from a diol and a dicarboxylic acid, which oligoester is thereafter catalytically hydrogenated in the liquid phase. Hydrogenation is carried out continuously at 180 to 250.degree. C. and at an H.sub.2 pressure of 100 to 400 bar, over a pelletised catalyst which is free from Zn oxide and which comprises pressed powders of Cu, Mn and Al oxides with a content of at least one oxide of metals of subgroup VI of the periodic table of the elements (Mendeleev). The amount of H.sub.2 is 20 to 100 times the amount required stoichiometrically.
    Type: Grant
    Filed: December 3, 1998
    Date of Patent: March 14, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Darsow, Wolfgang Dummer, Wilfried Niemeier
  • Patent number: 6031140
    Abstract: A continuous process for preparing isocamphyl-cyclohexanols from isocamphy-guaiacol or isocamphyl-phenol compounds by hydrogenating one of said compounds with hydrogen at elevated temperature and elevated pressure, comprising the use of support-free molded bodies which serve as catalysts and which are obtainable by reduction of molded bodies made of compressed powders of cobalt, manganese and copper (hydr)oxides and optionally of (hydr)oxides of the alkaline earth metals are used.
    Type: Grant
    Filed: November 30, 1998
    Date of Patent: February 29, 2000
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Darsow, Wilfried Niemeier
  • Patent number: 5728883
    Abstract: In the preparation of a mixture of cyclohexylamine and dicyclohexylamine by catalytic hydrogenation of aniline at elevated temperature and elevated H.sub.2 pressure, use is made of reduced, support-free catalysts which comprise pressed element (hydr)oxide powders of Co, Mn, alkaline earth metals and element (hydr)oxide powders of elements of transition groups V and/or VI of the Periodic Table.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: March 17, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Darsow, Wilfried Niemeier, Gerd-Michael Petruck
  • Patent number: 5705700
    Abstract: To prepare a mixture of cyclohexylamine and dicyclohexylamine by catalytic hydrogenation of aniline at elevated temperature and elevated H.sub.2 pressure, the catalyst system used comprises two reduced, unsupported catalysts A and B which are prepared from pressed element (hydr)oxide powders. Catalyst A comprises one or more of Fe, Co, Ni, also Mn, Cu and one or more of Ca, Sr, Ba. Catalyst B comprises one or more of Fe, Co, Ni, also Mn, Si and Mg.
    Type: Grant
    Filed: November 22, 1996
    Date of Patent: January 6, 1998
    Assignee: Bayer Aktiengesellschaft
    Inventors: Gerhard Darsow, Gerd-Michael Petruck, Wilfried Niemeier
  • Patent number: 5304525
    Abstract: A process for the preparation of aniline by hydrogenation of nitrobenzene in the gas phase in the presence of a catalyst containing a noble metal is described. The process can be carried out in an improved manner if the catalyst employed is palladium on graphite or petrol coke, as the support, containing 0.001-1% by weight of Pd, based on the total weight of the catalyst, it being possible for the catalyst also to contain, in addition to the Pd, 0.001-0.5% by weight of Ir and/or 0.001-0.3% by weight of Rh, all figures being based on the total weight of the catalyst.
    Type: Grant
    Filed: April 21, 1993
    Date of Patent: April 19, 1994
    Assignee: Bayer Aktiengesellschaft
    Inventors: Otto Immel, Helmut Waldmann, Rudolf Braden, Christian Frohlich, Gerhard Friedhofen, Wilfried Niemeier