Patents by Inventor John Francis Oswald

John Francis Oswald 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).

  • Patent number: 6242598
    Abstract: A process for preparing 2-(2,4-dihydroxyphenyl)-4.6-diaryl-s-triazines in three steps starting with cyanuric chloride is described. Step 1 involves the nucleophilic (basic) displacement of one chlorine atom with a phenolic moiety. Step 2 involves a Friedel-Crafts reaction using a Lewis acid catalyst (preferably aluminum chloride) to replace the remaining two chlorine atoms with aryl groups such as xylyl. Finally, step 3 involves replacing the phenolic moiety with resorcinol using either a Lewis acid or protic acid catalyst or combinations thereof. Some additional processes only peripherally related to the three-step process outlined above are also described for the preparation of various s-triazine compounds. The s-triazines prepared are useful as UV absorbers for the stabilization of organic substrates against the adverse effects of actinic light.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: June 5, 2001
    Assignee: Ciba Specialty Chemicals Corporation
    Inventors: Tyler Arthur Stevenson, Michael Ackerman, Pascal Hayoz, Roger Meuwly, John Francis Oswald, Christian Schregenberger