Patents by Inventor Cecilia Maria Ooelho de Figueiredo

Cecilia Maria Ooelho de Figueiredo 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).

  • Spherical catalyst, process for preparing a spherical polyethylene of ultra-high molecular weight
    Patent number: 6384163
    Abstract: A process for preparing a spherical polyethylene of ultra-high molecular weight. A process for preparing a spherical support for the polymerization of alpha-olefins from an ammonium dawsonite which is spray-dried and formed into spherical particles which are then calcined and impregnated with titanium to produce a spherical catalyst of good mechanical strength is described. Also described is the polymerization process which, in the presence of the spherical catalyst, yields polyolefin particles which preserve the spherical characteristics of the support, with low flow angle and good bulk density, as well as the product polyethylene obtained from the process.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: May 7, 2002
    Assignee: Petroleo Brasileiro S. A.-Petrobras
    Inventors: Jaime Correia da Silva, Cecilia Maria Ooelho de Figueiredo
  • Process for preparing a Ziegler-type spherical catalyst for alpha-olefin polymerization process
    Patent number: 5811362
    Abstract: A proces for preparing a spherical support for the polymerization of alpha-olefins from an ammonium dawsonite which is spray-dryed and formed into spherical particles which are then calcined and impregnated with titanium to produce a spherical catalyst of good mechanical strength is described. Also described is the polymerization process which, in the presence of the spherical catalyst, yields polyolefin particles which preserve the spherical characteristics of the support, with low flow angle and good bulk density, as well as the product polyethylene obtained from the process.
    Type: Grant
    Filed: November 18, 1997
    Date of Patent: September 22, 1998
    Assignee: Petroleo Brasileiro S.A.-Petrobras
    Inventors: Jaime Correia Da Silva, Cecilia Maria Ooelho De Figueiredo
  • Spherical ultra high molecular weight polyethylene
    Patent number: 5807950
    Abstract: A proces for preparing a spherical support for the polymerization of alpha-olefins from an ammonium dawsonite which is spray-dryed and formed into spherical particles which are then calcined and impregnated with titanium to produce a spherical catalyst of good mechanical strength is described. Also described is the polymerization process which, in the presence of the spherical catalyst, yields polyolefin particles which preserve the spherical characteristics of the support, with low flow angle and good bulk density, as well as the product polyethylene obtained from the process.
    Type: Grant
    Filed: May 8, 1997
    Date of Patent: September 15, 1998
    Assignee: Petroleo Brasileiro S.A.-Petrobras
    Inventors: Jaime Correia Da Silva, Cecilia Maria Ooelho De Figueiredo