Pretreatment of aluminium plate for flat printing - by anodic oxidation and additional cathodic treatment

摘要

Prepn. of an aluminium plate (or Al-alloy plate) for use as a base for a flat-printing plate by anodic oxidn. is improved in that the latter is followed by cathodic treatment is an acid or alkaline medium. Adhesion of the photosensitive layer subsequently applied onto the Al plate treated by this method is very good, and the wearing resistance and hence, the durability of the printing plate so produced is considerably improved. The process is relatively inexpensive.