Patents by Inventor Louis R. de Alvare

Louis R. de Alvare 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).

  • Azo colorants for ball point pen and ribbon inks
    Patent number: 4952677
    Abstract: Reddish-brown to yellow shade colorants suitable for ribbon and ball point inks are produced from the glassy waste by-product of pararosaniline manufacture by slurrying the residue in mineral acid, diazotizing, and coupling. the resulting colorants are useful in preparing inks.
    Type: Grant
    Filed: September 15, 1988
    Date of Patent: August 28, 1990
    Assignee: BASF Corporation
    Inventors: Floyd G. Spence, Louis R. de Alvare, Robert J. Allen
  • Colorants for ball-point pen and ribbon inks
    Patent number: 4824610
    Abstract: Substantially pure triarylmethane dyestuff salts free of contamination by arylamines are prepared by isolating in relatively pure form, the carbinol base corresponding to the dyestuff followed by salt formation by reaction with the appropriate acid. The resulting colorants are highly suitable for ball-point pen, printing, and ribbon inks.
    Type: Grant
    Filed: December 21, 1987
    Date of Patent: April 25, 1989
    Assignee: BASF Corporation
    Inventors: Reinhard J. Sappok, Louis R. de Alvare, Floyd G. Spence