Patents by Inventor Barbara Kuhlmann

Barbara Kuhlmann 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 manufacturing dialkyl carbonate from urea and alcohol
    Patent number: 5565603
    Abstract: A process for making a dialkyl carbonate which comprises reacting urea with a first alcohol in a carbamate reactor at a temperature and pressure sufficient to convert said urea to an alkyl carbamate; and reacting the alkyl carbamate with a second alcohol in the presence of a dialkyl isocyanato alkoxy tin catalyst or derivatives in a carbonate reactor at a temperature and pressure sufficient to convert the alkyl carbamate to a dialkyl carbonate, wherein the molar ratio of alkyl carbamate to second alcohol is in the range between about 2:1 to about 10:1 and wherein dialkyl carbonate is present within the carbonate reactor in an amount between about 1 to about 3 weight %, based on total alkyl carbamate and second alcohol content, and wherein the second alcohol is either the same as or different from the first alcohol or a mixture of alcohols.
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: October 15, 1996
    Inventors: Ramzi Y. Saleh, Robert C. Michaelson, Elena N. Suciu, Barbara Kuhlmann
  • Dialkyl isocyanato tin alcoholate catalysts and dimers thereof
    Patent number: 5561094
    Abstract: A process for making a dialkyl carbonate which comprises reacting urea with a first alcohol in a carbamate reactor at a temperature and pressure sufficient to convert said urea to an alkyl carbamate; and reacting the alkyl carbamate with a second alcohol in the presence of a dialkyl isocyanato alkoxy tin catalyst or derivatives in a carbonate reactor at a temperature and pressure sufficient to convert the alkyl carbamate to a dialkyl carbonate, wherein the molar ratio of alkyl carbamate to second alcohol is in the range between about 2:1 to about 10:1 and wherein dialkyl carbonate is present within the carbonate reactor in an amount between about 1 to about 3 weight %, based on total alkyl carbamate and second alcohol content, and wherein the second alcohol is either the same as or different from the first alcohol or a mixture of alcohols.
    Type: Grant
    Filed: April 26, 1995
    Date of Patent: October 1, 1996
    Inventors: Ramzi Y. Saleh, Robert C. Michaelson, Elena N. Suciu, Barbara Kuhlmann