Patent ID: 6974662

Claim:
A composition comprising a base precursor that is the salt of an organic base with an arylsulfonylacetic acid having the following structure: wherein the group R 1 represents a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, aryl group or heterocyclic group; each of R 2 and R 3 is independently a monovalent group; said base precursor being further in association with a filter dye; wherein the organic base is a diacidic to tetraacidic base having the following Structure; R 13 (—B) n wherein R 13 is an n-valent residue of a hydrocarbon or heterocyclic ring, each of which may have one or more substituent groups; “n” is an integer of 2 to 4; and wherein “B” is a monovalent group corresponding to an atomic group formed by removing one hydrogen atom from an guanidine having the Structure; wherein each of R 14 , R 15 , R 16 , R 17 and R 18 are independently a hydrogen, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aralkyl group, an aryl group and a heterocyclic group, wherein each of R 14 , R 15 , R 16 , R 17 and R 18 may have one or more substituent groups; or any two of R 14 , R 15 , R 16 , R 17 and R 18 may by combined together to form a five-membered or six-membered nitrogen containing heterocyclic ring; wherein base precursor is capable of bleaching the filter dye, thereby forming a composition that is useful as a thermally bleachable dye composition, wherein said arylsulfonylacetic acid undergoes decarboxylation at a temperature of 50 to 200° C. and will form a carbanion that is capable of abstracting a hydrogen from the organic base, rendering the organic base effective as a bleaching agent for said dye.