Patents by Inventor Frederic Lopez

Frederic Lopez 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 preparation of organic disulphides and polysulphides in the presence of polystyrene-divinyl-benzene (PS-DVB) resins possessing guanidine or amidine groups
    Patent number: 5767229
    Abstract: In a process for the preparation of organic disulphides and polysulphides by reaction of sulphur with a mercaptan or with a polysulphide of lower sulphur order in order to convert it into polysulphide of higher order, or alternatively by reaction of a mercaptan with an organic polysulphide of a high sulphur order in order to convert it into a polysulphide of lower sulphur order, in the presence of a catalyst in the form of a resin with a basic function, the resin is based on a polystyrene-divinyl benzene support functionalized with guanidine or amidine groups, and the reaction is preferably conducted in the presence of methanol.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: June 16, 1998
    Assignee: Elf Aquitaine Production
    Inventors: Emmanuel Arretz, Frederic Lopez