Imagewise structuring of diazosulfonate polymer films by UV light and laser irradiation - A comparison

Diazosulfonate polymers are applied as photo resins for printing plates and imaged via UV light and IR laser irradiation. Both methods lead to suffici ent differentiation in the exposed areas to allow image formation upon prin ting. Changes in the exposed areas compared to the unexposed sites are stud ies via UV and IR spectroscopy and the surface properties are characterized using contact angle measurements, ellipsometry, and atomic force microscop y. Upon UV irradiation the polymer films retain their smooth surface but th e changes in the solubility and wetting behavior are considerable. Laser im aging leads to a thermally induced foaming of the polymer film, and thus to a different ink accepting behavior.