| 摘要 |
In the electrochemical roughening of aluminum or its alloys useful for printing plate supports, an aqueous mixed electrolyte solution is employed, which contains nitric acid (HNO3) and, as a further inorganic electrolyte, at least one inorganic fluorine compound which is present in the form of an acid or an alkali metal salt (e.g., HF or NaF) and the anion of which contains fluorine and at least one further element (for example, SiF62- or PO3F2-). In particular, the solution contains from about 0.3 to 4% by weight of HNO3 and from about 0.05 to 5% by weight of the fluorine compound. The very uniformly roughened support materials are used in the production of offset printing plates.
|
