Patent ID: 7262305

Claim:
A 1,8-naphthoylene-1′,2′-benzimidazole sulfoderivative of the general structural formulae: wherein: p is an integer in the range of 1 to 2; q is an integer in the range of 1 to 2; m is an integer in the range of 0 to 4; z is an integer in the range of 0 to 6, such that values of m, z, p and q satisfy the equation m+z+p+q≦10; X and Y are individually selected from the group consisting of CH 3 , C 2 H 5 , OCH 3 , OC 2 H 5 , Cl, Br, OH, and NH 2 ; M is a counterion; and j is the number of said counterion in a single molecule of said 1,8-naphthoylene-1′,2′-benzimidazole sulfoderivative, or: wherein at least one of the sulfonic groups occupies position 2, 3, 6 or 7; m is an integer in the range of 1 to 4; z is an integer in the range of 0 to 4; X and Y are individually selected from NH 2 and/or OH; M is a counterion; and j is the number of said counterions.