Rare earth modified surface treating agent for copper and copper alloys and preparation method thereof

Abstract

The invention discloses a rare earth modified surface treating agent for copper and copper alloys and a preparation method thereof. The surface treating agent per liter comprises the following raw materials by weight: 1-3g of benzotriazole, 1-5g of sodium molybdate, 0.1-0.3g of sodium silicate, 0.3-0.6g of rare earth salt, 10-20g of complexing agent, 6-10g of sulfosalicylic acid, 0.2-0.6g of surfactant, a small amount of pH regulator and the balance water. The surface treating agent of the invention can be used for passivation at the room temperature, have short passivation time and be green and environmentally friendly; the passivated copper or copper alloy surface has good corrosion resistance; and the treating agent has simple treatment technology and is convenient for actual production.

Description

technical field [0001] The invention relates to a surface treatment agent for copper and its alloys, in particular to a rare earth modified surface treatment agent for copper and its alloys and a preparation method. Background technique [0002] Copper is one of the earliest metal materials contacted and used by human beings. Copper exists in elemental form in nature. As early as the Qijia culture in the upper reaches of the Yellow River in my country in the 17th century BC, people mastered the technology of cold forging and casting red copper. Today, as an engineering material, copper and copper alloys have excellent electrical conductivity, thermal conductivity, processability and good corrosion resistance, as well as sufficient mechanical strength, elasticity, wear resistance, etc., so they are used in electricity, electrical appliances, construction, It has a wide range of applications in shipbuilding, petrochemical, energy, national defense and other industrial fields....

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Problems solved by technology

[0005] In order to replace the hexavalent chromium passivation technology, the industry is actively researching the chromium-free passivation technology of copper and its alloys, among which Cr 3+ Low-priced chromium passivation as the main film-forming substance, but Cr 3+ There is also a certain degree of harm to the environment, and under certain conditions, it may also be converted into more harmful Cr 6+ , so it cannot be Cr 6+ The best alternative to passivation; the existing completely chromium-free treatment process for copper and its alloys generally uses benzotriazole (BTA) alone or uses it in combination with several other components, Its treatment process is relatively complicated, often requires heating, and the treatment time is also long. The test results show that its corrosion resistance effect is far from ideal compared with the traditional chromate treatment, and cannot meet the needs of actual production.

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