Tetrabenzodiazadiketoperylene pigments for laser marking

摘要

A method for laser marking a substrate which method comprises exposing a composition comprising a tetrabenzodiazadiketoperylene pigment to laser radiation to produce a fluorescent marking readily apparent under UV light is disclosed. Many of the tetrabenzodiazadiketoperylenes herein are novel. This method can yield fluorescent markings which are not readily apparent under ambient light. A method for producing non-fluorescent laser marked substrates containing tetrabenzodiazadiketoperylene dyes is also disclosed.