Patent ID: 7264916

Claim:
Method of coloring a polymeric material, characterized in that a polymeric material contains a) a latent acid, wherein the latent acid is of formula wherein ring A can contain one or more hetero atoms and/or can contain an anelated ring, R 1 is hydrogen, alkyl, alkenyl, aryl, R 2 , R 3 , R 4 and R 5 independently of each other are hydrogen or a functional substituent, and R stands for C 1 -C 6 alkyl, -Z 1 -Q 1 , or Z 2 -Q 2 , wherein Z 1 is a single bond, S, NH or O, and Q 1 is a heterocyclic ring system having from 5 to 9 ring atoms selected from C, S, O and N, with at least 2 carbon atoms in the ring system, and wherein Z 2 stands for C 1 -C 4 alkylene, which can be substituted by C 1 -C 4 alkyl or Q 3 , wherein Q 3 stands for phenyl which can be substituted one to three times with C 1 -C 4 alkyl, hydroxy, C 5 -C 8 cycloalkyl and/or a heterocyclic ring system having from 5 to 9 ring atoms selected from C, S, O and N, with at least 2 carbon atoms in the ring system, and Q 2 stands for phenyl which can be substituted one to three times with C 1 -C 4 alkyl, hydroxy, C 5 -C 8 cycloalkyl and/or a heterocyclic ring system having from 5 to 9 ring atoms selected from C, S, O and N, with at least 2 carbon atoms in the ring system, with the proviso that the hydrogen atom at the C-atom in α-position to R can be split off by irradiation, b) a colour former and c) optionally further ingredients is irradiated with UV-light and the latent acid is 0.001 to 10% by weight of the polymeric material.