Patents by Inventor Hans-Joachim Sandhagen

Hans-Joachim Sandhagen 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: 5625045
    Abstract: High functionality, low viscosity, light colored sucrose-based polyethers are prepared by reacting a starter mixture containing i) approximately 100 parts by weight of sucrose, ii) from about 30 to about 1000 parts by weight of a low molecular weight, relatively high valency alcohol and/or an alkoxylation product of such an alcohol and iii) an alkali metal hydroxide which has been prepared at a temperature of from about 20.degree. to about 110.degree. C. with an alkylene oxide at a temperature of from about 90.degree. to about 130.degree. C. and at a pressure of from about 0.3 to about 4 bar excess nitrogen pressure. These polyether polyols are particularly useful for the production of polyurethanes, particularly rigid polyurethane foams.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: April 29, 1997
    Assignee: Bayer Aktiengesellschaft
    Inventors: Pramod Gupta, Hans-Joachim Sandhagen, Werner Betz, Ulrich Leyrer, Martin Hoppe
  • Patent number: 5105019
    Abstract: The present invention relates to a process for removing a basic catalyst from a polyether polyol having a hydroxyl number of from 4 to 250 comprising adding from 0.7 to 7 percent by weight of water, based on the polyether polyol, to an alkaline reaction medium containing the polyether polyol at a temperature of from 20.degree. to 120.degree. C.; introducing 1 to 2 times the stoichiometric amount of gaseous carbon dioxide at a temperature of from 75.degree. to 120.degree. C., thereby forming a carbonate salt; and removing the carbonate salt by filtration.
    Type: Grant
    Filed: March 2, 1990
    Date of Patent: April 14, 1992
    Assignee: Bayer Aktiengesellschaft
    Inventors: Pramod Gupta, Hans-Joachim Sandhagen, Heinz-Jorg Rosenbaum
  • Patent number: 4143072
    Abstract: This invention relates to a process for the removal of troublesome secondary products, particularly small quantities of water, solvents, low molecular weight glycols, and pungent-smelling substances, from polyethers by means of a tubular coil evaporator.
    Type: Grant
    Filed: April 27, 1978
    Date of Patent: March 6, 1979
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hartmut Hetzel, Pramod Gupta, Hans-Joachim Sandhagen