A rust preventive and a method for preparing the same

Abstract

The present application discloses a kind of rust preventive, including the following raw materials: carbonate, rust preventive auxiliary agent, sodium tetraborate, amino resin polymer, complexing agent, nitrite, surfactant and water.The rust preventive can remove the rust on the surface of steel components and at the same time can passivate the steel components in the case of slight secondary rusting on the surface of steel components after pickling, and can effectively achieve temporary rust prevention of steel components.

Description

Technical Field

[0001] This invention belongs to the field of surface treatment technology, and specifically relates to a rust inhibitor and its preparation method. Background Technology

[0002] To effectively implement surface coating processes such as electrophoresis, spraying, and electroplating, steel components typically require pickling to remove rust and scale from their surfaces. However, steel components that have undergone pickling are highly susceptible to rusting again during subsequent processes. Without a subsequent rust removal step, this can lead to defects in the finished products produced by spraying or electrophoresis. Therefore, rust prevention after pickling is crucial for steel.

[0003] Currently, rust inhibitors with sodium nitrite as the main component are generally used for temporary rust prevention of pickled steel. This method is effective for steel components with simple structures, such as those without welds, water pockets, or crevices, that have not rusted again after pickling and before rust prevention. However, it is not effective for steel components with complex structures, acid trapped in crevices, or those that rust again after pickling and washing. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a rust inhibitor and its preparation method. This rust inhibitor can remove the rust on the surface of steel components when there is slight secondary rust on the surface after pickling, and at the same time passivate the steel components, effectively achieving temporary rust prevention for steel components.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A rust inhibitor comprising the following raw materials: carbonate, rust inhibitory additive, sodium tetraborate, amino resin polymer, complexing agent, nitrite, surfactant, and water.

[0007] Preferably, every 1000 parts by weight of the rust inhibitor comprises the following raw materials in parts by weight: 5-10 parts of carbonate; 2-5 parts of rust inhibitory additive; 3-8 parts of sodium tetraborate; 1-3 parts of amino resin polymer; 5-15 parts of complexing agent; 3-8 parts of nitrite; 0.5-2.0 parts of surfactant; water, balance.

[0008] Preferably, the carbonate is at least one of sodium carbonate and potassium carbonate.

[0009] Preferably, the rust inhibitor is at least one of triethanolamine, diethanolamine, and monoethanolamine.

[0010] Preferably, the CAS number of the amino resin polymer is 78578-28-6.

[0011] Preferably, the complexing agent is at least one of disodium EDTA, sodium citrate, and disodium HEDP.

[0012] Preferably, the nitrite is sodium nitrite.

[0013] Preferably, the surfactant is at least one of the penetrant JFC and short-chain branched propylene oxide-ethylene oxide alcohol ether.

[0014] A method for preparing a rust inhibitor as described above includes the following steps: mixing carbonate, rust inhibitor, sodium tetraborate, amino resin polymer, complexing agent, nitrite, surfactant and water to obtain the rust inhibitor.

[0015] Preferably, the method for preparing the rust inhibitor includes the following steps: mixing carbonate with a portion of water, then sequentially adding rust inhibitor, sodium tetraborate, amino resin polymer, complexing agent, nitrite and surfactant. During mixing, the next raw material is added only after the previous one has completely dissolved, and finally the remaining water is added.

[0016] The beneficial effects of this invention are:

[0017] (1) The rust inhibitor of the present invention can prevent rust while removing rust: the secondary water rust generated on the surface of steel components during pickling and water washing can be removed by the passivating rust inhibitor of the present invention, and at the same time, the surface of the steel components can be passivated and prevented from rust.

[0018] (2) The rust inhibitor of the present invention can effectively neutralize the acid hidden in the gaps of steel components. Because the present invention adds an appropriate amount of surfactant, it can achieve a good neutralization effect on the acid remaining in the gaps of steel components after pickling and rust removal, effectively preventing the acid remaining in the gaps of steel components after passivation and rust prevention from flowing out and causing the steel components to rust again. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments.

[0020] Example 1:

[0021] A rust inhibitor comprising the following raw materials in parts by weight: 5 parts sodium carbonate; 5 parts triethanolamine; 4 parts sodium tetraborate; 2 parts amino resin polymer (CAS No.: 78578-28-6); 12 parts disodium EDTA; 4 parts sodium nitrite; 1 part penetrant JFC; and 967 parts water.

[0022] The method for preparing the rust inhibitor as described above includes the following steps:

[0023] First, add 500 parts of water to a container, then add 5 parts of sodium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 467 parts of water to obtain the final product.

[0024] Example 2:

[0025] A rust inhibitor comprising the following raw materials in parts by weight: 6 parts potassium carbonate; 4 parts diethanolamine; 3 parts sodium tetraborate; 3 parts amino resin polymer (CAS No.: 78578-28-6); 12 parts disodium EDTA; 5 parts sodium nitrite; 0.8 parts short-chain branched propylene oxide-ethylene oxide alcohol ether; and 966.2 parts water.

[0026] The method for preparing the rust inhibitor as described above includes the following steps:

[0027] First, add 500 parts of water to a container, then add 6 parts of potassium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 466.2 parts of water to obtain the final product.

[0028] Example 3:

[0029] A rust inhibitor comprising the following raw materials in parts by weight: 6 parts potassium carbonate; 4 parts monoethanolamine; 5 parts sodium tetraborate; 2 parts amino resin polymer (CAS No.: 78578-28-6); 9 parts disodium HEDP; 6 parts sodium nitrite; 1.2 parts penetrant JFC; and 966.8 parts water.

[0030] The method for preparing the rust inhibitor as described above includes the following steps:

[0031] First, add 500 parts of water to a container, then add 6 parts of potassium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 466.8 parts of water to obtain the final product.

[0032] Example 4:

[0033] A rust inhibitor comprising the following raw materials in parts by weight: 6 parts potassium carbonate; 5 parts diethanolamine; 5 parts sodium tetraborate; 3 parts amino resin polymer (CAS No.: 78578-28-6); 13 parts sodium citrate; 6 parts sodium nitrite; 1.5 parts penetrant JFC; and 960.5 parts water.

[0034] The method for preparing the rust inhibitor as described above includes the following steps:

[0035] First, add 500 parts of water to a container, then add 6 parts of potassium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 460.5 parts of water to obtain the final product.

[0036] Example 5:

[0037] A rust inhibitor comprising the following raw materials in parts by weight: 8 parts sodium carbonate; 3 parts triethanolamine; 5 parts sodium tetraborate; 3 parts amino resin polymer (CAS No.: 78578-28-6); 13 parts sodium citrate; 5 parts sodium nitrite; 1.5 parts short-chain branched propylene oxide-ethylene oxide alcohol ether; and 1.5 parts water.

[0038] The method for preparing the rust inhibitor as described above includes the following steps:

[0039] First, add 500 parts of water to a container, then add 8 parts of sodium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 461.5 parts of water to obtain the final product.

[0040] Comparative Example 1 (does not contain diethanolamine compared to Example 2):

[0041] A rust inhibitor comprising the following raw materials in parts by weight: 6 parts potassium carbonate; 3 parts sodium tetraborate; 3 parts amino resin polymer (CAS No.: 78578-28-6); 12 parts disodium EDTA; 5 parts sodium nitrite; 0.8 parts short-chain branched propylene oxide-ethylene oxide alcohol ether; and 0.2 parts water.

[0042] The method for preparing the rust inhibitor as described above includes the following steps:

[0043] First, add 500 parts of water to a container, then add 6 parts of potassium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 470.2 parts of water to obtain the final product.

[0044] Comparative Example 2 (without sodium tetraborate compared to Example 2):

[0045] A rust inhibitor comprising the following raw materials in parts by weight: 6 parts potassium carbonate; 4 parts diethanolamine; 3 parts amino resin polymer (CAS No.: 78578-28-6); 12 parts disodium EDTA; 5 parts sodium nitrite; 0.8 parts short-chain branched propylene oxide-ethylene oxide alcohol ether; and 969.2 parts water.

[0046] The method for preparing the rust inhibitor as described above includes the following steps:

[0047] First, add 500 parts of water to a container, then add 6 parts of potassium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 469.2 parts of water to obtain the final product.

[0048] Comparative Example 3 (without amino resin polymer compared to Example 2):

[0049] A rust inhibitor comprising the following raw materials in parts by weight: 6 parts potassium carbonate; 4 parts diethanolamine; 3 parts sodium tetraborate; 12 parts disodium EDTA; 5 parts sodium nitrite; 0.8 parts short-chain branched propylene oxide-ethylene oxide alcohol ether; and 969.2 parts water.

[0050] The method for preparing the rust inhibitor as described above includes the following steps:

[0051] First, add 500 parts of water to a container, then add 6 parts of potassium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 469.2 parts of water to obtain the final product.

[0052] Comparative Example 4 (containing no short-chain branched propylene oxide-ethylene oxide alcohol ethers compared to Example 2):

[0053] A rust inhibitor comprising the following raw materials in parts by weight: 6 parts potassium carbonate; 4 parts diethanolamine; 3 parts sodium tetraborate; 3 parts amino resin polymer (CAS No.: 78578-28-6); 12 parts disodium EDTA; 5 parts sodium nitrite; and 967 parts water.

[0054] The method for preparing the rust inhibitor as described above includes the following steps:

[0055] First, add 500 parts of water to a container, then add 6 parts of potassium carbonate and mix. Next, add the remaining materials in sequence according to the formula ratio and stir until the solution is colorless and transparent (stir until clear after adding one material before adding the next material). Finally, add 467 parts of water to obtain the final product.

[0056] Experimental example:

[0057] Nine steel components with slight secondary rust on the surface after pickling and washing were immersed in the rust inhibitors of Examples 1-5 and Comparative Examples 1-4 for 10 minutes each. After immersion, it was observed whether the rust on the surface of the steel components was completely removed. Then, the treated steel components were exposed to air for 24 hours and the surface of the steel components was observed to see if there was any rust. The test results are shown in Table 1 below.

[0058] Table 1: Test Results

[0059]

[0060] As shown in Table 1, the rust inhibitor of the present invention has excellent rust removal and rust prevention effects on steel structures with slight secondary rust after pickling and water washing. Steel components treated with the rust inhibitor of the present invention have good temporary rust prevention effect, which can fully meet the requirements of subsequent automatic line processes such as electrophoresis or powder coating of steel components. It solves the problem of poor temporary rust prevention effect of steel components after existing rust prevention processes and secondary rust caused by residual acid in the crevices.

[0061] Meanwhile, comparing Example 2 with Comparative Examples 1-4, it can be seen that when other conditions remain unchanged, the rust inhibitor of the present invention lacks one of the following: rust inhibitor, sodium tetraborate, amino resin polymer, and surfactant. The rust removal and rust prevention effects of the rust inhibitor are all worse. This indicates that the rust inhibitor, sodium tetraborate, amino resin polymer, and surfactant in the present invention can play a synergistic role in the rust removal and rust prevention effects of the rust inhibitor.

[0062] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A rust inhibitor, characterized in that: Each 1000 parts by weight of the rust inhibitor comprises the following raw materials in parts by weight: 5-10 parts of carbonate; 2-5 parts of rust inhibitory additive; 3-8 parts of sodium tetraborate; 1-3 parts of 4-aminomethylstyrene-phenylene glycol copolymer; 5-15 parts of complexing agent; 3-8 parts of nitrite; 0.5-2.0 parts of surfactant; water, balance; wherein the carbonate is at least one of sodium carbonate and potassium carbonate; the rust inhibitory additive is at least one of triethanolamine, diethanolamine and monoethanolamine; the complexing agent is at least one of disodium EDTA, sodium citrate and disodium HEDP; the nitrite is sodium nitrite; and the surfactant is penetrant JFC.

2. A method for preparing the rust inhibitor as described in claim 1, characterized in that: Includes the following steps: The product is obtained by mixing carbonate, rust inhibitor, sodium tetraborate, 4-aminomethylstyrene-phenylene glycol copolymer, complexing agent, nitrite, surfactant and water.

3. The preparation method according to claim 2, characterized in that: Includes the following steps: After mixing carbonate with 500 parts of water, add rust inhibitor, sodium tetraborate, 4-aminomethylstyrene-phenylene glycol copolymer, complexing agent, nitrite and surfactant in sequence. When mixing, add the next ingredient only after the previous one has completely dissolved, and finally add the remaining water.

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