Richard L Wolf

US Patent:

40678407, Jan 10, 1978

Filed:

May 24, 1976

Appl. No.:

5/689187

Inventors:

Richard E. Wolf - Prospect Heights IL

Assignee:

DeSoto, Inc. - Des Plaines IL

International Classification:

C08K 510
C08L 126
C08L 3104

US Classification:

260 296R

Abstract:

Protective coatings, such as paints and liquid formulations therefor, containing a masked chromogen which signals contact with a body fluid when the protective coating is masticated or ingested are disclosed. The chromogen is capable of producing a contrasting color when masticated and/or ingested, thereby signaling that the individual who masticated and/or ingested the chromogen may have ingested an undesirable or hazardous substance, e. g. , a lead-based paint, that has been covered by the protective coating. The chromogen is substantially indiscernible in the paint and converts by reaction with an activator substance, e. g. , by reaction with saliva, gastric juices, or the like, to a colored form which then stains the body fluids and/or the body tissues, and which may also stain the original source of the undesirable substance. The chromogen may be a leuco base or a color base of a dye, or it may be a color indicator substance or a reagent specific to the undesirable or hazardous substance or to a body fluid component. Preferably the chromogen is present in the form of pressure-rupturable microcapsules that release the chromogen when masticated.