Patents by Inventor Wern T. Tsai

Wern T. Tsai 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 improving storage stability of pigments
    Patent number: 5282897
    Abstract: A process for improving the storage stability of a colored organic pigment in powder form which comprises coating pigment particles with a partially or completely hydrolysed compound of an element of Group IVA or Group IVB of the Periodic Table in its IV oxidation state, thereby inhibiting reduction of the tinting strength of the pigment on storage.
    Type: Grant
    Filed: August 11, 1992
    Date of Patent: February 1, 1994
    Assignee: Ciba-Geigy Corporation
    Inventors: Phillipe Bugnon, Abul Iqbal, Iain F. Fraser, Wern T. Tsai