Corrosion inhibitor for inhibiting copper corrosion in saline water (seawater) and preparation method of corrosion inhibitor

Abstract

The invention discloses a corrosion inhibitor for inhibiting copper corrosion in saline water (seawater) and a preparation method of the corrosion inhibitor, belonging to the field of corrosion prevention. The corrosion inhibitor is composed of 3-9 parts of calcium gluconate, 5-15 parts of sodium tungstate, 2-8 parts of sodium gluconate, 1-3 parts of tolytriazole, 0.6-2 parts of polyaspartic acid, 0.3-0.8 part of dodecyl glucoside, 0.2-0.5 part of methylchloroisothiazolinone and 10-15 parts of water. The preparation method comprises the following steps: (a) dissolving calcium gluconate into water according to a certain ratio, and dissolving by stirring; (b) adding tolytriazole into the solution according to a certain ratio, and dissolving by stirring; (c) sequentially adding sodium tungstate, sodium gluconate, polyaspartic acid and dodecyl glucoside according to a certain ratio, and dissolving by stirring; and (d) finally, adding methylchloroisothiazolinone according to a certain ratio, and stirring for 10-15 minutes. The corrosion inhibitor disclosed by the invention is simple in preparation process, mild in condition, convenient to use and environmentally friendly.

Description

technical field [0001] The invention belongs to the field of anticorrosion, and more specifically relates to a corrosion inhibitor for inhibiting copper corrosion in salt water (sea water) medium and a preparation method thereof. Background technique [0002] Copper has excellent strength, machinability, thermal conductivity, electrical conductivity, weldability and corrosion resistance, and is widely used in thermal cycle systems in industrial production. In general, copper has better corrosion resistance, but in oxygen-containing water, oxidizing acid and containing Cl ～ , NH 4 + Coordination ions can be formed in the solution, resulting in more serious corrosion. At present, among various refrigerants, industrial calcium chloride and sodium chloride aqueous solutions are still widely used in various refrigerators and equipment and occasions that need to lower the freezing point due to their low freezing point and low price. However, due to the certain corrosiveness of...

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Problems solved by technology

However, the corrosion inhibitor has the problems of complex composition, large dosage and poor thermal stability.

[0006] Li Yucai et al. (Li Yucai, Zhang Shiwen, Chen Zhongxiang, Sun Liming, Research on Copper Corrosion Inhibitors in Green Brine Medium, Hebei Chemical Industry, No. 8, 2006, 42-43) studied a cost-effective copper corrosion inhibitor in brine medium. The corrosion agent is composed of sodium molybdate, sodium gluconate, benzotriazole, polyaspartic acid and dodecyl glucoside in a weight ratio of 0.6:1.0:0.6:0.2:0.1:0.05. The corrosion inhibition rate of copper in 22.5% salt water medium can reach more than 98.5%, but the corrosion inhibitor also has the problem of using benzotriazole, and sodium molybdate is a weak oxidizing corrosion inhibitor, it begins to adsorb On the hydrated oxide film, the film is changed from anion selectivity to cation selectivity, and the metal surface is passivated to form a passivation film, but the film is not uniform and dense enough, the effect is not ideal, and the amount of corrosion inhibitor is large

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