Normal-temperature film passivating agent for processing before electro-coating of iron and steel workpiece and preparation method thereof

Abstract

The invention relates to a normal-temperature film passivating agent for processing before electro-coating of iron and steel workpiece, containing the following raw materials in percentage by mass: 3-8% of phytic acid, 1-3% of citric acid, 1-3% of fluorozirconate, 0.1-2% of sodium bromate, 2-6% of sodium benzoate, 1-3% of sodium carbonate, 5-9% of triethanolamine and the balance of tap water. Thepreparation method comprises the steps as follows: adding tap water in a reaction kettle; turning on a stirrer with rotational speed of about 450-550 revolutions/min; adding sodium carbonate, sodium benzoate, sodium bromate, triethanolamine, phytic acid, citric acid and fluozirconate in sequence, stirring for 0.5-1.5h so as to lead the solution to be lavender and evenly transparent; sampling, examining, filling and packing. The passivating agent can be used at normal temperature so that the whole chemical processing process is simple, and the operation is convenient; the heating device is saved as heating is unnecessary, the production cost is low, no toxic or harmful substances are discharged, and the normal-temperature film passivating agent is good for the health of operators and the environmental protection. The preparation process is simple, and easy for control and operation.

Description

technical field [0001] The invention relates to a film passivator, in particular to a normal temperature film passivator before electrophoretic coating of iron and steel workpieces and a preparation method thereof. Background technique [0002] Electrophoretic coating of iron and steel workpieces is the process of depositing water-soluble paint with standardized process parameters on the cathode to form a continuous, complete and dense electrophoretic coating film under the action of a specific voltage and current of a DC power supply. The electrophoretic coating process technology for steel workpieces is widely used in the automotive industry for the primer coating of the vehicle and the main component system spray coating money or the protective coating of the final protective equipment. Before electrophoretic coating of steel workpieces, the substrate must be chemically treated to form a protective film on the surface. The main functions of this protective film are: first...

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Problems solved by technology

As we all know, as long as the phosphating process is used, there will be PO 4 -3 、Cr +6 , Dich