Environment-friendly chromium-free rust-proof passivation solution and preparation method thereof

Abstract

The invention discloses an environment-friendly chromium-free rust-proof passivation solution. The rust-proof passivation solution is prepared from the raw materials of, by weight, 100 parts of deionized water, 2-10 parts of salicylic acid, 4-10 parts of benzotriazole, 3-10 parts of sodium citrate, 2-10 parts of 2-chlorine-4,5-dihydro-1H-imidazole sulfonate, 1-10 parts of hexafluorotitanic acid, 1-5 parts of sodium gluconate, 1-5 parts of zinc oxide, 4-10 parts of cerium nitrate, 3-10 parts of silane-modified polyphosphazene-polyethersulfone block copolymers, 5-10 parts of silver nitrate, 1-10parts of n-butanol, 1-5 parts of sodium silicate, 1-5 parts of 2-mercapto benzimidazole-5-sodium sulfonate dehydrate, 1-10 parts of oxalic acid, 1-5 parts of ethyl alcohol and 1-5 parts of 3-[(methylol)methylamine] ethanesulfonic acid. The obtained environment-friendly chromium-free rust-proof passivation solution can be used for low-temperature surface treatment, is high in surface treatment efficiency, environmentally friendly and good in rust-proof performance and has good market prospects.

Description

technical field [0001] The invention relates to the technical field of metal surface treatment, in particular to a green, environment-friendly, chromium-free anti-rust passivation solution and a preparation method thereof. Background technique [0002] Tin-plated steel sheet is a product made of tin-plated on thin steel plate. As a metal packaging material, tin-plated steel sheet has good performance. Its characteristics include 1. Non-toxic, the tin layer itself is harmless to the human body, and it can be used as food packaging Very safe; 2. Beautiful appearance, easy to paint and print on the surface; 3. Tin itself has good corrosion resistance, protecting the substrate from corrosion; 4. Good solderability, easy to make containers; 5. Tin has good ductility 6. The tin layer is soft, and the tin layer will not crack or fall off. In actual use, passivation is often required. [0003] At present, the passivation treatment process of chromic anhydride and dichromate is oft...

AI Technical Summary

Problems solved by technology

[0004] In order to replace the hexavalent chromium passivation technology, the industry is currently actively researching the chromium-free passivation technology of tin-plated steel sheets, 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 tin-plated steel sheets generally uses benzotriazole (BTA) alone or uses it in combination with several other components. The 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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