Patents by Inventor Peter Essen

Peter Essen 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 purification of 2,6-diisopropyl phenol
    Patent number: 5175376
    Abstract: The object of the invention is a new method for the purification of 2,6-diisopropyl phenol (propofol). The invention is characterized in that the raw product obtained from the alkylation of propene with phenol is crystallized at a temperature where propofol crystallizes but the isomers and other phenol derivatives formed in the reaction are still in liquid form, i.e. at a temperature of -25.degree. to +18.degree. C. especially at -20.degree. to -10.degree. C., without a solvent or using a suitable solvent, such as hexane or petrol ether.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: December 29, 1992
    Assignee: Leiras Oy
    Inventors: Kauko Nieminen, Peter Essen