Patent ID: 7125443

Claim:
A lightfast ink composition comprising: at least one lightfast colorant that is a benzophenone derivative of formula (1) below: wherein Y 1 is one selected from the group consisting of —H, —OH, —NH 2 , —NHR 1 , —N(R 1 ) 2 , —SH, and a C 1 –C 30 heteroalkyl group, where R 1 is a C 1 –C 6 alkyl group; each of Y 2 and Y 3 is independently selected from the group consisting of —H, —OH, —NH 2 , —NHR 1 , —N(R 1 ) 2 , where R 1 is a C 1 –C 6 alkyl group, —SH, a substituted or unsubstituted C 1 –C 30 alkyl group, a substituted or unsubstituted C 1 –C 30 alkenyl group, a substituted or unsubstituted C 1 –C 30 alkynyl group, a substituted or unsubstituted C 1 –C 30 heteroalkyl group, a substituted or unsubstituted C 6 –C 30 aryl group, a substituted or unsubstituted C 7 –C 30 arylalkyl group, a substituted or unsubstituted C 3 –C 30 heteroaryl group, and a substituted or unsubstituted C 4 –C 30 heteroarylalkyl group; n is an integer from 0 to 6; R is selected from the group consisting of a substituted or unsubstituted C 1 –C 30 alkylene group, a substituted or unsubstituted C 1 –C 30 alkenylene group, a substituted or unsubstituted C 1 –C 30 alkynylene group, a substituted or unsubstituted C 1 –C 30 heteroalkylene group, a substituted or unsubstituted C 6 –C 30 arylene group, a substituted or unsubstituted C 7 –C 30 arylenealkylene group, a substituted or unsubstituted C 3 –C 30 heteroarylene group, and a substituted or unsubstituted C 4 –C 30 heteroarylenealkylene group; X is a linker selected from the group consisting of —CONH—, —NHCO—, —COO—, —OCO—, —CO—, —O—, —S—, —SO 2 —, —SO 3 —, —O—P(═O)(OH)—O—, and —O—P(OH)—O—; and Y is a colorant residue; and an aqueous medium.