| abstract |
A process is provided for the manufacture of a support for a lithographic printing plate precursor, the process comprising treating at least one surface of a metallic substrate with an aqueous solution comprising a salt of a metal from Group IB, IIB, IVA, IVB, VB, VIA, VIB, VIIB or VIII of the Periodic Table whilst applying a constant voltage or constant current. These lithographic printing plate precursors provide plates showing good resistance to abrasion, corrosion, staining and scumming, both on development and on press. Additionally, the plates display excellent coating adhesion in image areas, together with very good exposure latitude and solvent resistance. The metallic substrate preferably is aluminium or an aluminium alloy. The salt may be a salt of Ti, Zr, Hf, Mo, W, V, Mn, Ni, Cu, Zn, Sn, Nb, Ta, Ce, Se, Si, Co or Fe. The solution may additionally contain poly(acrylic acid) or a copolymer of acrylic acid with vinylphosphonic acid. A light sensitive coating may be subsequently applied on the treated surface. The resulting substrate is then exposed and developed. The salt may be part of an anodising bath or the metallic substrate may be immersed in the salt solution after graining and anodising. The solution may also contain aluminium ions. The salt may be included in an anodising bath or applied after graining and anodising. |