Patent ID: 6844139

Claim:
A method for forming images, the method comprising, in the order given, the steps of: a) imaging an imageable element and forming an imaged imageable element comprising unimaged regions and complementary imaged regions, and b) developing the imaged imageable element and removing the unimaged regions but not the complementary imaged regions; in which: the imageable element comprises a substrate, and a layer of a negative working imageable composition over the substrate, the negative working imageable composition comprises: a polymeric binder; an acid activatable crosslinking agent; and an acid generator of the structure: in which: Y is hydrogen, halo, alkyl, diphenylamino, phenylthio, or (CH 2 ) k SO 3 − in which k is 1 to 4; R 1 , R 2 , R 3 , and R 4 , are each independently hydrogen or SO 3 − with the proviso that the anion has two to four SO 3 − groups; Z 1 and Z 2 are each independently a benzo group or a naphtho group; Z 3 is two hydrogen atoms, a cyclohexene residue or a cyclopentene residue; X1 and X2 are each independently S, O, NH, CH 2 , or CMe 2 ; Q ⊕ is an onium cation; n is 1 to 4; and m is 1 to 3, with the proviso that m is 1 when the anion has two SO 3 − groups; m is 2 when the anion has three SO 3 − groups; and m is 3 when the anion has four SO 3 − groups.