| 摘要 |
Affinity transitions from hydrophobic to hydrophilic states, rather than ablation mechanisms, facilitate the creation of an imagewise lithographic pattern on a printing plate. In various embodiments, a lithographic printing member comprises a topmost “imaging” layer that undergoes, in response to heat, a transition from a hydrophobic and oleophilic state to a hydrophilic state (which may or may not also be oleophilic); and a substrate disposed below the imaging layer. The affinity change in the imaging layer may be due essentially to a foaming agent therein. The foaming agent decomposes upon heating, creating a gas that foams the surface of the imaging layer. The resulting spongelike texture enables the surface to retain water, i.e., renders it hydrophilic. |
