Zinc layer surface passivating treatment liquid

Abstract

The invention discloses zinc layer surface passivating treatment liquid. The zinc layer surface passivating treatment liquid consists of the following components by weight percent: a) 6.0 to 10.0 percent of inorganic salt corrosion inhibitor, b) 1.0 to 8.0 percent of organic acid metal activating agent, c) 6.0 to 10.0 percent of pH value regulating agent, d) 8.0 to 30.0 percent of alcohol cosolvent, e) 10.0 to 30.0 percent of silicon containing sealant, f) 30.0 to 50.0 percent of cationic or non-ionic waterborne polyurethane emulsion, and g) 0.5 to 2.0 percent of dispersing agent, defoaming agent, thickening agent and wetting agent. The film obtained by the treatment liquid has binding force with a galvanizing layer, is compact, colorless and transparent, and has high white rust resistance.

Description

technical field [0001] The invention relates to an anti-corrosion treatment solution for galvanized layer on metal surface, in particular to a chromium-free passivation solution for the surface of galvanized layer on metal surface. Background technique [0002] Using surface galvanizing to protect the base metal can significantly reduce the corrosion of ferrous metals in the iron and steel industry. About half of the zinc produced in the world is used in the galvanizing process, because galvanized sheets have good corrosion resistance and relatively low prices. It is cheap and widely used in aviation, automobiles, building materials, home appliances, machinery and other fields. It has also become one of the fastest-growing steel varieties in my country's output in recent years. [0003] In steel coatings whose main purpose is to prevent atmospheric corrosion, anodic coatings such as galvanized coatings can not only cut off the atmosphere, but more importantly, zinc itself is ...

AI Technical Summary

Problems solved by technology

This chromium-free treatment solution has the advantage of not containing chromium, and its corrosion resistance is better, but the storage stability of this treatment solution is relatively poor, the preparation process is more complicated and a large amount of low-molecular alcohol solvents are used (the content is more than 90%), so Volatilization of organic matter will be generated during operation or use, causing environmental pollution

[0008] Chinese patent CN200410021031.1 discloses an alternative chromate passivation solution for electro-galvanized layer and hot-dip galvanized layer, mainly composed of inorganic salt, organic acid complexing agent and inorganic salt redox agent, etc., the formed The corrosion resistance of the passivation film is "equal to the hexavalent chromium color passivation process", but the passivation film is "a color passivation film with more light blue and green" rather than a colorless film, which cannot meet the requirements of maintaining the plating quality after passivation. The bright white luster of the zinc layer will limit the application of this passivation solution in the hot-dip galvanized layer

Chinese patent CN02815757.5 discloses a chromium-free composition, which belongs to pure inorganic passivation, and is composed of titanium ions, fluorides and oxidizing agents. It can be used for passivation treatment on the surface of zinc layer, but the blue inorganic conversion coating

In addition, because the final system is acidic, the use of silicone acrylic emulsion will cause the system stability to decline

Chinese patent CN00114178.3 discloses a chromium-free passivation solution, which is composed of water-based acrylic resin and molybdate. The pH value of the system is 6-9, which can ensure the stability of the passivation solution system, but the corrosion resistance Still general, unable to meet the requirements of actual working conditions

This surface treatment agent can effectively prevent red rust, but white rust caused by corrosion of the zinc layer often occurs

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