Patent ID: 7662308

Claim:
A fluorescent colorant of formula (I) wherein, m is 1 or 2; n is 1-18; X is a direct bond, —O—, —S—, —NH—, —CO—, or —COO—; each R is independently selected from the group consisting of C 1 -C 25 alkyl, C 2 -C 25 alkyl interrupted one or more times by one or more groups selected from —O— and —S—, C 2 -C 24 alkenyl, C 3 -C 24 alkenyl interrupted one or more times by one or more groups selected from —O— and —S—, C 7 -C 9 phenylalkyl, a group —(CH 2 )n-X—(Y)z wherein n is defined as above and z is 1 or ½ and when more than one z is present each z is independently selected, phenyl and phenyl substituted 1 to 5 times by one or more groups selected from C 1 -C 8 alkyl, C 1 -C 8 alkyloxy and halogen; Y is a radical of a chromophore selected from the group consisting of napthalimides, diketopyrrolopyrroles, perylenes, quinacridones, benzoxanthenes, xanthenes, diphenylmaleimides, acetoacetamides, perylenemonoimides, and phthalimides, wherein when more than one Y is present, each Y is selected independently of the others.