| 摘要 |
The present invention relates to the use of an aqueous composition for pretreating can body stock, in the course of which an inorganic-organic conversion layer is formed, which, as such, effects outstanding sliding behaviour of the shaped can body stock and in addition offers an outstanding holding primer for subsequent coating. The invention comprises in this case a process in which the can body stock which is deep drawn to form the half-open can cylinder, before further shaping processes, is contacted with an acidic aqueous composition which contains water-soluble inorganic compounds of the elements Zr, Ti, Si, Hf or Ce, water-soluble polymers having carboxyl groups or hydroxyl groups and also a dispersed wax. Both the outer and the inner surfaces of metallic can cylinders can be pretreated in the process according to the invention. In addition, the invention relates to an acidic aqueous composition that is particularly suitable in the pretreatment process, which aqueous composition contains water-soluble polymers selected from condensation products of glycoluril and aldehydes. In addition, a production process for can cylinders comprising the pretreatment according to the invention is described. |
