ANODIC OXIDATION OF SURFACE OF PLATE, FOIL OR BAND COMPOSED OF ALUMINUM OR ALMINUM ALLOY

摘要

Process for anodising the surface of plates, foils or strips made of aluminium or aluminium alloys in an aqueous electrolyte which contains one or more acids and also, optionally, one or more additives and which contains, as additive or as one of the additives or as acid or as one of the acids, a silane or a plurality of silanes of the general formula I …IMAGE… where the indices and the variables have the following meaning:… y is an integer from 1 to 4;… n is 0, 1 and 2 independently of y;… R1 and R2 are C1-C9-alkyl and C6-C12-aryl, R1 and R2 being identical to, or different from, each other;… and… X is the radicals X1 to X11, …IMAGE… where the variables have the following meaning:… R3 is a hydrogen atom, C1-C9-alkyl, an alkane-carboxylic anhydride ring formed from the alkanecarboxylic acid radical containing 1 to 9 carbons atoms and a carboxylic acid group linked to R3 …IMAGE… R4 and R5 are the radical R1;… R6 is a hydrogen atom and the radical R1;… Z is a hydrogen atom and an alkali metal cation;… Ar is C6-C12-arylene; and… Hal is a chlorine and bromime atom;… the silanes of the general formula I (= silanes I) being dissolved in the electrolyte solution in hydrolysed and/or condensed form. Also the use of the plates, foils or strips made of aluminium or aluminium alloy anodised by this process for producing bases for photosensitive lithographic printing plates or offset printing plates.