Film treating agent for treatment before electro-coating of die-cast aluminum alloy workpiece and preparation method thereof

Abstract

The invention relates to a film treating agent for treatment before electro-coating of die-cast aluminum alloy workpiece, containing the following raw materials in percentage by mass: 2-10% of fluorozirconate, 1-13% of nitric acid, 1-5% of citric acid, 1-8% of phytic acid, 0.5-3% of hydrofluoric acid, 0.3-1.2% of ammonium bromate, 3-8% of ammonium bicarbonate, and the balance of tap water. The preparation method comprises the steps as follows: adding metered tap water in a reaction kettle; turning on a stirrer at normal temperature and normal pressure with rotational speed about 450-550 revolutions / min; and, adding ammonium bicarbonate, ammonium bromate, fluorozirconate, nitric acid, citric acid, phytic acid and hydrofluoric acid in sequence, completely dissolving and packing. The film treating agent for treatment before electro-coating of die-cast aluminum alloy workpiece produces no toxic or harmful substance during the treating process and has no influence on the operator and the environment; besides, the treatment can be carried out at normal temperature without heating, so that the device is simplified and the energy is saved.

Description

Technical field [0001] The invention relates to a treatment agent, in particular to a film treatment agent before electrophoretic coating of a die-cast aluminum alloy workpiece and a preparation method thereof. Background technique [0002] Electrophoretic coating is to dilute the electrophoretic paint with water to a solid content of about 10-15%, add it to the electrophoresis tank, immerse the workpiece as an electrode, and pass a direct current under the specified voltage condition. At this time, the resin and pigment in the electrophoretic paint It moves to the workpiece and adheres to the surface of the workpiece to form a water-insoluble coating. Deionized water is used to wash away the paint solution attached to the surface, and a uniform electrophoretic paint layer is formed after drying. For steel workpieces before electrophoretic coating, the surface of the substrate must be chemically pretreated to form a phosphating film, and for aluminum and aluminum alloy surfaces b...

AI Technical Summary

Problems solved by technology

During the treatment process, the existing treatment agents will produce toxic and harmful substances, such as phosphate, heavy metal salts, hexavalent chromium and dichromate, etc., which will adversely affect the physical and mental health of operators and the environment. Heating equipment consumes a lot of energy