Photoimaging technique on printing Al plate via self-assembly multilayer films based on diazoresin

Abstract

A photoimaging technique on a printing aluminum plate (anodized oxidation Al plate) via self-assembly multilayer thin film from nitro-containing diazoresin (NDR) as cationic polyelectrolyte and various anionic polyelectrolytes has been developed. It was confirmed that, under UV-irradiation, the linkage nature of the films changes from ionic to covalent and the solubility of the films converts dramatically, that is, the exposed area of the film becomes insoluble in H2O–DMF–LiCl (2 : 4 : 1 wt %) ternary solvent, but mainly the unexposed area will be dissolved. After developing in ternary solvent, an image that accepts ink easily appears on the printing Al plate. To resolve the ink-stain problem, originating from a trace remainder of the NDR on the unexposed area of the Al plate, a surface modification technique by polyphosphoric acid, which reacts with NDR to form a hydrophilic surface, was developed. The thickness, homogeneity, and surface morphology of the multilayer film (on mica) determined by atomic force microscopy and UV-vis spectra were also reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1983–1987, 2001