Patents by Inventor Stelvio Papetti

Stelvio Papetti 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).

  • Method of making expandable styrene-type beads
    Patent number: 4286069
    Abstract: Expandable styrene-type polymer beads having a short cooling time are made by impregnating the polymer beads, after the substantial completion of the polymerization, in an aqueous suspension medium comprising a suspending agent and about 0.005-0.3%, based on the weight of water, of non-ionic surfactant which is a copolymer of propylene oxide and ethylene oxide having an HLB number of 8-18 and an average molecuar weight of at least 1,000, and by subsequently washing and drying the beads.
    Type: Grant
    Filed: October 28, 1980
    Date of Patent: August 25, 1981
    Assignee: American Hoechst Corporation
    Inventors: James E. Millington, Stelvio Papetti
  • ABS polymer and process for its preparation
    Patent number: 4064116
    Abstract: ABS polymers having improved physical properties are prepared by graft polymerizing, in an aqueous medium, and in the presence of a suspending agent, styrene and acryonitrile onto a butadiene polymer in the form of a latex using certain peroxy ester catalysts.
    Type: Grant
    Filed: May 7, 1975
    Date of Patent: December 20, 1977
    Assignee: Foster Grant Co., Inc.
    Inventor: Stelvio Papetti
  • Compositions having high impact at low rubber levels
    Patent number: 4046839
    Abstract: ABS polymers having improved physical properties are prepared by graft polymerizing, in an aqueous medium and in the presence of an effective amount of suspending agent and polymerization catalyst, styrene and acrylonitrile onto a butadiene polymer in the form of a latex, said butadiene polymer latex being characterized by a particle size of about 1000 to 3000 A, a gel content of about 20-85% by weight, and a swell index of about 18-150.
    Type: Grant
    Filed: August 29, 1975
    Date of Patent: September 6, 1977
    Assignee: Foster Grant Co., Inc.
    Inventor: Stelvio Papetti