Patent ID: 7470315

Claim:
A naphthalocyanine dye of formula (I): wherein M is a metal group or is absent; R 1 and R 2 are independently selected from the group consisting of: hydrogen and C 1-12 alkoxy; X is selected from the group consisting of: O, S and —NH—; Ar 1 , Ar 2 , Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 and Ar 8 are selected from the group consisting of: phenyl, naphthyl, pyridyl, furanyl, pyrollyl and thiophenyl, each of Ar 1 , Ar 2 , Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 and Ar 8 being optionally substituted with 1, 2, 3, 4 or 5 groups, each group being independently selected from the group consisting of: C 1-12 alkyl, C 1-12 alkoxy, C 1-12 arylalkyl, C 1-12 arylalkoxy, —(OCH 2 CH 2 ) d OR d , cyano, halogen, amino, hydroxyl, thiol, —SR v , —NR u R v , nitro, phenyl, phenoxy, —CO 2 R v , —C(O)R v , —OCOR v , —SO 2 R v , —OSO 2 R v , —NHC(O)R v , —CONR u R v , —CONR u R v , sulfonic acid, sulfonic acid salt and sulfonamide; d is an integer from 2 to 5000; R d is H, C 1-8 alkyl or C(O)C 1-8 alkyl; and R u and R v are independently selected from the group consisting of: hydrogen, C 1-12 alkyl, phenyl or phenyl-C 1-8 alkyl; and wherein at least one of Ar 1 , Ar 2 , Ar 3 , Ar 4 , Ar 5 , Ar 6 , Ar 7 and Ar 8 is substituted with a sulfonic acid or a sulfonic acid salt.