Patents by Inventor Robert A. Koster

Robert A. Koster 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).

  • Difunctional living free radical polymerization initiators
    Patent number: 5677388
    Abstract: A living free-radical polymerization process for preparing polymers from vinyl aromatic monomers comprising polymerizing the vinyl aromatic monomer in the presence of a difunctional nitroxyl initiator.
    Type: Grant
    Filed: October 8, 1996
    Date of Patent: October 14, 1997
    Assignee: The Dow Chemical Company
    Inventors: Robert A. Koster, Duane B. Priddy, Irene Li
  • Difunctional living free radical polymerization initiators
    Patent number: 5627248
    Abstract: A living free-radical polymerization process for preparing polymers from vinyl aromatic monomers comprising polymerizing the vinyl aromatic monomer in the presence of a difunctional nitroxyl initiator.
    Type: Grant
    Filed: September 26, 1995
    Date of Patent: May 6, 1997
    Assignee: The Dow Chemical Company
    Inventors: Robert A. Koster, Duane B. Priddy, Irene Li
  • Free radical polymerization
    Patent number: 5618900
    Abstract: A process of polymerizing a monomer capable of undergoing free radical polymerization, comprising contacting the monomer with a diradical initiator at a temperature sufficient to initiate free radical polymerization, wherein said diradical initiator contains sites of C--C unsaturation which cyclize to form a diradical.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: April 8, 1997
    Assignee: The Dow Chemical Company
    Inventors: Ray E. Drumright, Robert H. Terbrueggen, Duane B. Priddy, Robert A. Koster
  • Process for hydrolysis of ortho-aromatic di-aryl ethers
    Patent number: 4978811
    Abstract: Ortho-aromatic diaryl ethers, such as o-biphenylyl phenyl ether, are hydrolyzed to corresponding phenolic compounds, such as o-phenylphenol and phenol, when contacted with water in the presence of ceria or thoria at a temperature of between about 250.degree. C. and 700.degree. C.
    Type: Grant
    Filed: April 1, 1988
    Date of Patent: December 18, 1990
    Assignee: The Dow Chemical Company
    Inventors: Robert A. Koster, Philip J. Brondsema, Willis J. Pennington, William C. Sumner, Susan E. Vilmer
  • Transparent impact resistant polymeric compositions and process for the preparation thereof
    Patent number: 4530973
    Abstract: Impact-resistant transparent polymeric compositions are prepared comprising particulate diene-monovinylidene aromatic block copolymer elastomer dispersed in a matrix comprising polymerized monovinylidene aromatic and acrylate monomers. These compositions can be advantageously prepared by adding the elastomeric block copolymer to an agitated polymerization system at a point where the elastomer will become dispersed as particles immediately or nearly immediately after addition.
    Type: Grant
    Filed: March 11, 1983
    Date of Patent: July 23, 1985
    Assignee: The Dow Chemical Company
    Inventors: Robert A. Koster, Tom D. Traugott