Patents by Inventor Tobias Caesar Keller

Tobias Caesar Keller 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).

  • Process for the production of di- and polyamines of the diphenylmethane series
    Patent number: 10239984
    Abstract: The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent, or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.
    Type: Grant
    Filed: July 2, 2015
    Date of Patent: March 26, 2019
    Assignee: COVESTRO DEUTSCHLAND AG
    Inventors: Jürgen Arras, Stefan Wershofen, Javier Pérez-Ramirez, Tobias Caesar Keller
  • PROCESS FOR THE PRODUCTION OF DI- AND POLYAMINES OF THE DIPHENYLMETHANE SERIES
    Publication number: 20170158798
    Abstract: The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent, or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.
    Type: Application
    Filed: July 2, 2015
    Publication date: June 8, 2017
    Inventors: Jürgen Arras, Stefan Wershofen, Javier Pérez-Ramirez, Tobias Caesar Keller