Non-phosphate film agent

Abstract

The invention relates to a non-phosphate film agent, comprising the following components by weight percent: 2.5-4.5% of succinic acid, 0.8-2% of sodium molybdate, 0-3% of sodium nitrate, 0-5% of citric acid, 0-0.5% of sodium fluoride, 0-0.8% of tannin, 0-1.5% of oxalic acid, 0-0.05% of sodium dodecyl sulfate, the balance of water. The invention has the advantages that: the non-phosphate film agent contains no phosphor, thus being really environmentally friendly; antirust performance is good; combining power with molding powder and paint and adhesive force are all excellent, thus meeting ROHS standard; when in use, aluminum alloy work piece, galvanized work piece and steel work piece can be placed in the same bath solution for coating, thus greatly simplifying the production technology andreducing equipment investment; and suspended matter produced when being continuously used for three months is only 10-20 kilograms, thus solving the difficult problem that one day is stopped in production per week for clearing phosphated slag when using phosphoric film agent.

Description

technical field [0001] The invention relates to a phosphorus-free coating agent, which is used in the pre-coating process of metal surfaces. Background technique [0002] Film agent is a kind of metal surface treatment agent, which can react with metal and form a water-insoluble, chemically inert, and firmly attached protective film on the metal surface while removing rust on the metal surface. This protective film is beneficial to prevent Metal oxidation is also conducive to the subsequent metal surface spraying process to enhance the bonding and adhesion of the sprayed paint film, plastic powder and metal, so it is widely used in the production of metal products such as automobiles, refrigerators, and air conditioners. [0003] Coating agents include phosphorus-containing coating agents and non-phosphorus coating agents. Phosphorus-containing coating agents cause serious environmental pollution, and a large amount of phosphate-containing wastewater and waste residues will ...

AI Technical Summary

Problems solved by technology

[0003] Coating agents include phosphorus-containing coating agents and non-phosphorus coating agents. Phosphorus-containing coating agents cause serious environmental pollution, and a large amount of phosphate-containing wastewater and waste residues will be generated during use. The treatment process of these wastewater and waste residues is relatively complicated. The cost is also higher

Although some of the existing phosphorus-free film agents do not contain phosphorus, they contain other harmful components, such as fluozirconic acid, etc. These harmful substances also pollute the environment; although some phosphorus-free film agents do not contain phosphorus, But its effect is only equivalent to antirust agent, it does not produce oxidation or replacement reaction with the metal surface, after the metal is treated with this phosphorus-free coating agent, the protective film formed on the metal surface can play a certain role in preventing metal oxidation , but the adhesion and adhesion between this protective film and the paint film and plastic powder are very poor, and the film is easy to peel off from the metal surface after a long time; , once ions enter the production process, the agent must be replaced

[0004] In addition, different types of coating agents on the market can only be applied to different types of metal workpieces. For example, aluminum alloy workpieces generally use chromium-containing coating agents, and steel workpieces often use phosphorus-containing coating agents. Therefore, when processing different metal workpieces, Cannot be placed in the same bath for coating