Chromium-free and phosphorus-free sealing agent for tin-plated plate as well as preparation method and use method of chromium-free and phosphorus-free sealing agent

The invention relates to the technical field of metal surface treatment, in particular to a chromium-free and phosphorus-free sealing agent for a tin plate as well as a preparation method and a use method of the chromium-free and phosphorus-free sealing agent. The preparation method provided by the invention comprises the following steps: mixing an organic silane coupling agent and an alkali metal hydroxide aqueous solution, hydrolyzing, carrying out vacuum distillation, and adding an acidic aqueous solution of a water-soluble inorganic compound to obtain the chromium-free and phosphorus-free sealing agent, the water-soluble inorganic compound in the acidic aqueous solution of the water-soluble inorganic compound comprises one or more of Zr, Ti and Si. The chromium-free and phosphorus-free sealing agent prepared by the preparation method is an aqueous solution, does not contain chromium and phosphorus compounds, and does not contain organic volatile substances. 本发明涉及金属表面处理技术领域，尤其涉及一种用于镀锡板的无铬无磷封闭剂及其制备方法和使用方法。本