Patent ID: 7108742

Claim:
An ink composition containing (a) a compound of formula II, III or IV wherein R 2 , is hydrogen or C 1 –C 6 alkyl, and R 1 and R 3 are methyl, t-butyl, n-pentyl or phenyl, Ln represents a lanthanide, n denotes 3 or 4, m denotes a number from 1 to 4, when n is 3, m denotes a number from 1 to 4, when n is 4, m denotes 1, L is a compound of formula V, VI, VII, VIII or IX wherein R 4 , R 5 and R 6 are each independently of the other hydrogen, halogen, C 1 –C 6 alkyl, C 5 –C 24 aryl, C 6 –C 24 aralkyl, C 1 –C 6 alkoxy, dialkylamino or a cyclic amino group and R 7 is hydrogen, C 1 –C 6 alkyl, C 5 –C 24 aryl or C 6 –C 24 aralkyl: and (b) a liquid ink carrier.