Patents by Inventor Jurgen Zander

Jurgen Zander 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: 5120875
    Abstract: In the preparation of chlorinated aromatic amines by reaction of corresponding nitro compounds with hydrogen under pressure, at elevated temperature and in the presence of a solvent and small amounts of a basic compound, fewer by-products are formed by using platinum and nickel and/or cobalt on an active charcoal support.
    Type: Grant
    Filed: August 13, 1990
    Date of Patent: June 9, 1992
    Assignee: Bayer Aktiengesellschaft
    Inventors: Udo Birkenstock, Ulrich Kappler, Herbert Schmidt, Jurgen Zander
  • Patent number: 4400560
    Abstract: A process for preparing a mixture of polyhydroxyl compounds having low molecular weight by catalytically hydrogenating a formose mixture with hydrogen on a metal catalyst. The hydrogenation is carried out at a pH of 7.5 to 12.5 and at elevated temperature and pressure. The formose mixture comprises (i) up to 70 wt. % formose, (ii) up to 1.6 wt. % lead ions and (iii) up to 5 wt. % calcium ions with at least one of (ii) or (iii) being present. The catalyst which is present in an amount of 4-240 wt. % (based on formose solution) is a compound taken from the group consisting of nickel, cobalt and compounds thereof. The mixture of polyhydroxyl compounds made in accordance with the present invention is useful as a starting material in the production of polyether polyols, polyester polyols and polyurethane plastics.
    Type: Grant
    Filed: March 9, 1981
    Date of Patent: August 23, 1983
    Assignee: Bayer Aktiengesellschaft
    Inventors: Roland Richter, Hanns P. Muller, Kuno Wagner, Rudolf Helm, Jurgen Zander
  • Patent number: 4230637
    Abstract: An improved process for the preparation of a chlorinated aromatic amine by reaction of a chlorinated aromatic nitro compound of the formula ##STR1## wherein R.sup.1 and R.sup.2 are identical or different and denote hydrogen or chlorine with hydrogen in the presence of a hydrogenation catalyst under pressure at an elevated temperature in the presence of a solvent and a minor amount of a basic compound, the improvement residing in employing ammonia as the basic compound.
    Type: Grant
    Filed: September 8, 1978
    Date of Patent: October 28, 1980
    Assignee: Bayer Aktiengesellschaft
    Inventor: Jurgen Zander
  • Patent number: 4163752
    Abstract: A process has been invented for the preparation of aminonaphthalenesulphonic acids by the catalytic hydrogenation of salts of nitronaphthalenesulphonic acids with hydrogen in the presence of Raney nickel catalysts at elevated temperature and pressure, said catalysts comprising a combination of fresh Raney nickel catalyst and Raney nickel catalyst which has already been used in prior hydrogenation or hydrogenations.
    Type: Grant
    Filed: January 11, 1978
    Date of Patent: August 7, 1979
    Assignee: Bayer Aktiengesellschaft
    Inventors: Otto Barth, Hans-Joachim Becker, Horst Behre, Reinhard Kaiser, Guido Steffan, Jurgen Zander