Patents by Inventor Ernst-Heinrich Rohe

Ernst-Heinrich Rohe 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: 3931320
    Abstract: A process for the production of aromatic polyamines comprising condensing primary or secondary aromatic amines with formaldehyde or a formaldehyde precursor in the presence of an acid catalyst and liberating the polyamines on completion of condensation by the addition of a basically reacting reagent, wherein a mixture containing amine, catalyst, aldehyde, precondensates formed therefrom, and water, issuing from a mixer at a maximum temperature of about 40.degree.C., is separated intoA. a side stream in which the heat liberated from the reacting mixture is dissipated in a heat exchanger following dilution of the total quantity of mixture of amine and catalyst, cooled to below about 40.degree.C., required for the reaction and the mixture thus obtained is reintroduced at a temperature of at most about 40.degree.C. into the mixer where formaldehyde is added, andB. a main stream which is pumped, through a reaction zone kept at a maximum of about 40.degree.C.
    Type: Grant
    Filed: May 23, 1972
    Date of Patent: January 6, 1976
    Assignee: Bayer Aktiengesellschaft
    Inventors: Willi Eifler, Roderich Raue, Ernst-Heinrich Rohe, Josef Finkel