Patents by Inventor Prakob Kitipichai

Prakob Kitipichai 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).

  • Thermally transferable fluorine-containing AZO dyes
    Patent number: 5350731
    Abstract: The present invention provides fluorine-containing arylazoanaline dyes that are useful in thermal transfer systems. Specifically, the present invention provides thermal transfer donor sheets containing dyes of the following formula: ##STR1## wherein: R.sup.1 is a (C.sub.1-20)alkyl or hydroxy(C.sub.1-20)alkyl group; R.sup.2 is a hydroxy(C.sub.1-20)alkyl or (C.sub.1-20)alkylene--OC(O)NH--(C.sub.1-20)alkylene--OC(O)--R.sup.4 wherein R.sup.4 is a (C.sub.1-20)alkenyl group or a polymerized alkenyl group; and R.sup.3 is F or CF.sub.3. Useful dyes of this formulation are stable under ambient conditions for at least about 6 months.
    Type: Grant
    Filed: December 7, 1993
    Date of Patent: September 27, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Linda K. Williams, Prakob Kitipichai, Cecil V. Francis, Ramaiah Muthyala