Corrosion and rust resistant converting agent and preparation method thereof

Abstract

The invention discloses a corrosion and rust resistant converting agent and a preparation method thereof. The corrosion and rust resistant converting agent is prepared from the following raw materials in parts by weight: 2 to 20 parts of gallic acid, 0.5 to 6 parts of phytic acid, 5 to 25 parts of synergist, 4 to 23 parts of glycerol and 5 to 25 parts of water, wherein the synergist is prepared from the following raw materials: amino phosphonic acid, carbodiimide hydrochloride and N-hydroxysuccinimide. By optimizing the formula of the corrosion-resistant rust conversion agent, the rust conversion agent with good adhesion, rust conversion degree and corrosion resistance can be prepared, and the problems that in the prior art, a rust conversion agent is low in adhesion, low in rust conversion degree, poor in corrosion resistance and the like are solved.

Description

Technical Field

[0001] The present invention belongs to the field of rust converters, and particularly relates to a corrosion-resistant rust converter and a preparation method thereof. Background Art

[0002] In a high-humidity environment, metal components in application fields such as bridges and tunnels are prone to rusting, and it is difficult to replace and repair them.

[0003] The more traditional treatment methods are sandblasting rust removal or manual rust removal followed by re-coating. Although the former has good rust removal effect, there are problems such as waste of grit and damage to the metal substrate. The latter has problems such as incomplete rust removal and long time consumption. Based on this, rust converters have the advantages of high-efficiency rust removal and protection of metal substrates, and are a popular research and development direction for the anti-corrosion of metal components in fields such as tunnels and bridges. Therefore, it is very necessary to find a long-lasting and corrosion-resistant rust converter. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to solve the problems of low adhesion, low rust conversion degree, and poor corrosion resistance of existing rust converters.

[0005] To solve the above technical problems, the present invention provides a corrosion-resistant rust converter. The raw materials of the corrosion-resistant rust converter include: 2 to 20 parts by weight of gallic acid, 0.5 to 6 parts by weight of phytic acid, 5 to 25 parts by weight of a synergist, 4 to 23 parts by weight of glycerol, and 5 to 25 parts by weight of water;

[0006] Among them, the raw materials of the synergist include aminophosphonic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide.

[0007] Optionally, the raw materials of the corrosion-resistant rust converter include: 4 to 15 parts by weight of gallic acid, 1 to 4 parts by weight of phytic acid, 7 to 22 parts by weight of a synergist, 6 to 20 parts by weight of glycerol, and 6 to 21 parts by weight of water.

[0008] Optionally, the synergist is prepared by the following method:

[0009] Dissolve dithioglycolic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide in tetrahydrofuran, then add aminophosphonic acid, and stir at 30°C to 60°C for 2 to 6 hours, concentrate, wash, and dry to obtain the synergist.

[0010] Optionally, the molar ratio of dithioglycolic acid to aminophosphonic acid is 1:1 - 2.5.

[0011] Optionally, the molar ratio of dithioglycolic acid to aminophosphonic acid is 1:1.5 - 2.2.

[0012] Optionally, the aminophosphonic acid is any one or more of 1-aminomethylphosphonic acid, 2-aminoethylphosphonic acid, 3-aminopropylphosphonic acid, 4-aminobutylphosphonic acid, 6-aminohexanephosphonic acid, (1-aminopentyl)phosphonic acid, (1-aminohexyl)phosphonic acid, and (1-aminooctyl)phosphoric acid.

[0013] Optionally, the weight of the carbodiimide hydrochloride accounts for 3% - 5% of the weight of the aminophosphonic acid.

[0014] Optionally, the weight of the N-hydroxysuccinimide accounts for 5% - 10% of the weight of the aminophosphonic acid.

[0015] In addition, the present invention also provides a preparation method of a corrosion-resistant rust converter for preparing the corrosion-resistant rust converter as described above. The preparation method includes: uniformly mixing the raw materials of the corrosion-resistant rust converter to obtain the corrosion-resistant rust converter.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The present invention provides a corrosion-resistant rust converter, and the raw materials of the corrosion-resistant rust converter include: 2 to 20 parts by weight of gallic acid, 0.5 to 6 parts by weight of phytic acid, 5 to 25 parts by weight of a synergist, 4 to 23 parts by weight of glycerol, and 5 to 25 parts by weight of water; wherein, the raw materials of the synergist include aminophosphonic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide. By optimizing the formulation of the corrosion-resistant rust converter, the present invention can prepare a rust converter with good adhesion, rust conversion degree, and corrosion resistance, solving the problems of low adhesion, low rust conversion degree, and poor corrosion resistance of the rust converter in the prior art.

[0018] Furthermore, by using aminophosphonic acid and dithioglycolic acid to prepare a synergist, a long-chain compound with a benzene ring, disulfide bond, and alkyl chain is anchored in the rust conversion layer through the formation of a complex between the phosphate group in the synergist and iron rust, forming a film layer, further improving the protective effect of the rust conversion layer on steel; wherein, the film layer formed by the synergist in the rust conversion layer has good hydrophobicity and rigidity, can resist the intrusion of external water molecules, and thus plays a corrosion inhibition role; furthermore, by introducing a disulfide bond, the rust conversion layer has a high electronegativity, can improve the adhesion of the rust conversion layer through chemical adsorption, and can achieve a certain degree of active repair after being damaged by external force, thereby enhancing the corrosion resistance.

[0019] In addition, it can be seen from the test results that by using the preparation method of the rust converter of the present invention, a rust converter with good adhesion, rust conversion degree, and corrosion resistance can be obtained. Detailed Embodiments

[0020] As described in the background art, in the prior art, sandblasting rust removal or manual rust removal methods require re - coating. Although the former has good rust removal effect, there are problems such as sand waste and damage to the metal substrate, while the latter has problems such as incomplete rust removal and long time consumption.

[0021] To solve the above problems, an embodiment of the present invention provides a corrosion - resistant rust converter. The raw materials of the corrosion - resistant rust converter include: 2 to 20 parts by weight of gallic acid, 0.5 to 6 parts by weight of phytic acid, 5 to 25 parts by weight of synergist, 4 to 23 parts by weight of glycerol, and 5 to 25 parts by weight of water; wherein, the raw materials of the synergist include aminophosphonic acid, carbodiimide hydrochloride, and N - hydroxysuccinimide. By optimizing the formula of the corrosion - resistant rust converter, an embodiment of the present invention can prepare a rust converter with good adhesion, rust conversion degree, and corrosion resistance, solving the problems of low adhesion, low rust conversion degree, and poor corrosion resistance of the rust converter in the prior art.

[0022] In addition, an embodiment of the present invention also provides a preparation method of a rust converter, which can obtain a rust converter with good adhesion, rust conversion degree, and corrosion resistance.

[0023] Unless otherwise specified, the present invention generally has no special restrictions on the sources of the reagents used. For example, commercially available ones can be used.

[0024] An embodiment of the present invention provides a corrosion - resistant rust converter. The raw materials of the corrosion - resistant rust converter include: 2 to 20 parts by weight of gallic acid, 0.5 to 6 parts by weight of phytic acid, 5 to 25 parts by weight of synergist, 4 to 23 parts by weight of glycerol, and 5 to 25 parts by weight of water; wherein, the raw materials of the synergist include aminophosphonic acid, carbodiimide hydrochloride, and N - hydroxysuccinimide.

[0025] Optionally, in some embodiments, the raw materials of the corrosion - resistant rust converter include: 4 to 15 parts by weight of gallic acid, 1 to 4 parts by weight of phytic acid, 7 to 22 parts by weight of synergist, 6 to 20 parts by weight of glycerol, and 6 to 21 parts by weight of water.

[0026] Optionally, in some embodiments, the synergist is prepared by the following method:

[0027] Dissolve dithioglycolic acid, carbodiimide hydrochloride, and N - hydroxysuccinimide in tetrahydrofuran, then add aminophosphonic acid, and stir at 30 °C to 60 °C for 2 h to 6 h, then concentrate, wash, and dry to obtain the synergist.

[0028] It should be noted that the amino group in the aminophosphonic acid in the synergist raw material can be bonded to the carboxyl group in the dithiolsalicylic acid to form a long-chain compound. The phosphate group in the synergist can undergo ligand exchange with rust to form an Fe-O-P complex. Furthermore, the above long-chain compound can form a uniform and stable film layer in the rust conversion layer to enhance the protection of steel. On the one hand, the film layer structure contains a benzene ring structure and an alkyl chain segment, having good hydrophobicity and rigidity, which can resist the intrusion of external water molecules and thus play a corrosion inhibition role; on the other hand, the disulfide bond in the film layer structure has a high electronegativity, which can improve the adhesion of the rust conversion layer through chemical adsorption and can achieve self-repair after being damaged by external forces, thereby enhancing the corrosion resistance.

[0029] In addition, the inventors also found during the research that if dithiolsalicylic acid and aminophosphonic acid are directly mixed as components of the rust converter, omitting the preparation of the synergist by pre-bonding, dithiolsalicylic acid and aminophosphonic acid cannot fully play their respective roles; if only aminophosphonic acid is used without dithiolsalicylic acid, a long-chain compound with a benzene ring structure and a disulfide bond cannot be formed, and a film layer with hydrophobic and self-repairing properties cannot be obtained; if only dithiolsalicylic acid is used without aminophosphonic acid, a film layer cannot be formed either, and the chain with a disulfide bond and a benzene ring cannot be anchored in the rust conversion layer near the steel surface, resulting in possible local excess or local deficiency in the self-repair and hydrophobicity of the coating; if salicylic acid is used to replace dithiolsalicylic acid, since there is no disulfide bond in the film layer, the chemical adsorption and self-repair properties of the coating are affected.

[0030] Optionally, in some embodiments, the molar ratio of the dithiolsalicylic acid to the aminophosphonic acid is 1:1 - 2.5. For example, in one embodiment, the molar ratio of the dithiolsalicylic acid to the aminophosphonic acid is 1:1.1.

[0031] Preferably, in some embodiments, the molar ratio of the dithiolsalicylic acid to the aminophosphonic acid is 1:1.5 - 2.2.

[0032] Optionally, in some embodiments, the aminophosphonic acid is any one or more of 1-aminomethylphosphonic acid, 2-aminoethylphosphonic acid, 3-aminopropylphosphonic acid, 4-aminobutylphosphonic acid, 6-aminohexanephosphoric acid, (1-aminopentyl)phosphonic acid, (1-aminohexyl)phosphonic acid, (1-aminooctyl)phosphoric acid. For example, in one embodiment, the aminophosphonic acid is 4-aminobutylphosphonic acid or 6-aminohexanephosphoric acid. In one embodiment, when 1-aminomethylphosphonic acid is used to replace 4-aminobutylphosphonic acid, the alkyl chain in the film layer is slightly shorter and the hydrophobicity becomes worse.

[0033] Optionally, in some embodiments, the weight of the carbodiimide hydrochloride accounts for 3% - 5% of the weight of the aminophosphonic acid.

[0034] Optionally, in some embodiments, the weight of N-hydroxysuccinimide accounts for 5%-10% of the weight of the aminophosphonic acid.

[0035] In addition, an embodiment of the present invention also provides a preparation method of a corrosion-resistant rust converter for preparing the corrosion-resistant rust converter as described above. The preparation method includes: mixing the raw materials of the corrosion-resistant rust converter evenly to obtain the corrosion-resistant rust converter. The rust converter prepared by the above method has good adhesion, rust conversion degree and corrosion resistance.

[0036] Example 1 Preparation of Rust Converter

[0037] 1. Raw Materials

[0038] 10.6 parts by weight of gallic acid, 3 parts by weight of phytic acid, 16.2 parts by weight of synergist, 14.7 parts by weight of glycerol, 15.4 parts by weight of water.

[0039] The raw materials of the synergist include:

[0040] Aminophosphonic acid: 4-aminobutylphosphonic acid;

[0041] Carbodiimide hydrochloride;

[0042] N-hydroxysuccinimide.

[0043] Among them, the synergist is prepared by the following preparation method:

[0044] Dissolve dithioglycolic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide in an appropriate amount of tetrahydrofuran, then add 4-aminobutylphosphonic acid, react at 45°C for 4 h. After the reaction is completed, rotary evaporate to remove the solvent tetrahydrofuran, and then wash 5 times with deionized water and dry to obtain the synergist.

[0045] The molar ratio of the above dithioglycolic acid to 4-aminobutylphosphonic acid is 1:1.9; the weight of carbodiimide hydrochloride accounts for 4% of the weight of 4-aminobutylphosphonic acid; the weight of N-hydroxysuccinimide accounts for 7% of the weight of 4-aminobutylphosphonic acid.

[0046] 2. Preparation Method

[0047] Put gallic acid, phytic acid, and synergist into glycerol and water according to the raw material formula, and stir at room temperature for 1 h to obtain the target rust converter.

[0048] Example 2

[0049] 1. Raw Materials

[0050] 4.6 parts by weight of gallic acid, 1.3 parts by weight of phytic acid, 7.2 parts by weight of synergist, 6.5 parts by weight of glycerol, 6.8 parts by weight of water.

[0051] The raw materials of the synergist include:

[0052] Aminophosphonic acid: 4-aminobutylphosphonic acid;

[0053] Carbodiimide hydrochloride;

[0054] N-hydroxysuccinimide.

[0055] Among them, the synergist is prepared by the following preparation method:

[0056] Dissolve dithiolic salicylic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide in an appropriate amount of tetrahydrofuran, then add 4-aminobutylphosphonic acid, react at 60 °C for 2 h. After the reaction is completed, rotary evaporate to remove the solvent tetrahydrofuran, and then wash with deionized water 5 times and dry to obtain the synergist.

[0057] The molar ratio of the above-mentioned dithiolic salicylic acid to 4-aminobutylphosphonic acid is 1:1.5; the weight of carbodiimide hydrochloride accounts for 4% of the weight of 4-aminobutylphosphonic acid; the weight of N-hydroxysuccinimide accounts for 7% of the weight of 4-aminobutylphosphonic acid.

[0058] 2. Preparation method

[0059] Put gallic acid, phytic acid, and the synergist into glycerol and water according to the raw material formula, and stir at room temperature for 0.5 h to obtain the target rust converter.

[0060] Example 3

[0061] 1. Raw materials

[0062] 14.5 parts by weight of gallic acid, 4 parts by weight of phytic acid, 22 parts by weight of the synergist, 20 parts by weight of glycerol, and 21 parts by weight of water.

[0063] The raw materials of the synergist include:

[0064] Aminophosphonic acid: 4-aminobutylphosphonic acid;

[0065] Carbodiimide hydrochloride;

[0066] N-hydroxysuccinimide.

[0067] Among them, the synergist is prepared by the following preparation method:

[0068] Dissolve dithiolic salicylic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide in an appropriate amount of tetrahydrofuran, then add 4-aminobutylphosphonic acid, react at 30 °C for 6 h. After the reaction is completed, rotary evaporate to remove the solvent tetrahydrofuran, and then wash with deionized water 5 times and dry to obtain the synergist.

[0069] The molar ratio of the above dithiosalicylic acid to 4-aminobutylphosphonic acid is 1:2.1; the weight of carbodiimide hydrochloride accounts for 4% of the weight of 4-aminobutylphosphonic acid; the weight of N-hydroxysuccinimide accounts for 7% of the weight of 4-aminobutylphosphonic acid.

[0070] 2. Preparation method

[0071] Put gallic acid, phytic acid, and synergist into glycerol and water according to the raw material formula, and stir at room temperature for 1 h to obtain the target rust converter.

[0072] Example 4

[0073] The difference between this example and Example 1 is that in the preparation of the synergist, the molar ratio of dithiosalicylic acid to 4-aminobutylphosphonic acid is 1:1.1, and the others are the same as in Example 1.

[0074] Example 5

[0075] The difference between this example and Example 1 is that in the preparation of the synergist, the molar ratio of dithiosalicylic acid to 4-aminobutylphosphonic acid is 1:2.5, and the others are the same as in Example 1.

[0076] Example 6

[0077] The difference between this example and Example 1 is that in the preparation of the synergist, 1-aminomethylphosphonic acid is used to replace 4-aminobutylphosphonic acid, and the others are the same as in Example 1.

[0078] Example 7

[0079] The difference between this Example 7 and Example 1 is that the synergist is prepared by the following method:

[0080] Mix dithiosalicylic acid, carbodiimide hydrochloride, N-hydroxysuccinimide, and 4-aminobutylphosphonic acid to obtain the synergist.

[0081] The others are the same as in Example 1.

[0082] Example 8

[0083] The difference between this example and Example 1 is that in the preparation of the synergist, salicylic acid is used to replace dithiosalicylic acid. Example 8 is prepared by the following method:

[0084] Dissolve salicylic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide in an appropriate amount of tetrahydrofuran, then add 4-aminobutylphosphonic acid, react at 30 °C for 6 h. After the reaction is completed, rotary evaporate to remove the solvent tetrahydrofuran, and then wash with deionized water 5 times and dry to obtain the synergist.

[0085] The molar ratio of the above salicylic acid to 4-aminobutylphosphonic acid is 1:2.1; the weight of carbodiimide hydrochloride accounts for 4% of the weight of 4-aminobutylphosphonic acid; the weight of N-hydroxysuccinimide accounts for 7% of the weight of 4-aminobutylphosphonic acid.

[0086] Comparative Example 1

[0087] The difference between this comparative example and Example 1 is that the synergist is 4-aminobutylphosphonic acid, and the others are the same as in Example 1.

[0088] Comparative Example 2

[0089] The difference between this comparative example and Example 1 is that the synergist is dithiosalicylic acid, and the others are the same as in Example 1.

[0090] Performance Test

[0091] Add the rust converters prepared in Examples 1-8 and Comparative Examples 1-2, which account for 3% of the mass of the acrylate emulsion, to the acrylate emulsion containing 40 wt% water, and mix evenly to obtain a coating for the following performance tests:

[0092] Adhesion: Tested in accordance with GB / T 1720-2020 "Cross-Cut Test for Paint Films".

[0093] Degree of rust conversion: Apply the rust converter to the rusty steel plate. After it is completely dry, peel off the coating and observe the color of the rust layer and the state of the substrate.

[0094] Salt spray resistance: In accordance with GB / T 1771-2007 "Paints and Varnishes - Determination of Resistance to Neutral Salt Spray". The performance test results are shown in Table 1.

[0095] Table 1 Performance test results of the rust converters prepared in Examples 1-8 and Comparative Examples 1-2

[0096]

[0097] It can be seen from the results in Table 1 that the rust converters prepared in Examples 1-3 have good adhesion, degree of rust conversion and corrosion resistance.

[0098] Compared with Example 1, the adhesion, degree of rust conversion and corrosion resistance of Example 4 have all decreased. The reason may be that: the dosage of aminophosphonic acid is less. On the one hand, the number of phosphate groups decreases, resulting in a decline in the auxiliary rust conversion ability of the enhancer. On the other hand, the density of the film layer formed with dithiosalicylic acid decreases, resulting in a decline in the corrosion inhibition ability of the coating.

[0099] Compared with Example 1, the adhesion, degree of rust conversion and corrosion resistance of Example 5 have not been significantly improved, indicating that too much aminophosphonic acid has no obvious improvement on the coating performance.

[0100] Compared with Example 1, the corrosion resistance of Example 6 is slightly decreased. The reason may be that the alkyl chain in the aminomethylphosphonic acid structure is slightly shorter, resulting in a shorter overall chain length of the enhancer, which affects the penetration of its phosphate groups into the rust layer, and thus leads to a decline in various properties.

[0101] Compared with Example 1, when the coating on the steel plate surface of Example 7 was scraped off, it was found that the color of the metal matrix surface was relatively darker, indicating that the acidity of the coating was slightly stronger. This may be because the directly added dithiosalicylic acid and aminophosphonic acid contain more carboxyl groups, and there is no anchoring of aminophosphonic acid by dithiosalicylic acid. The phosphate groups in its structure are added with phytic acid and gallic acid, resulting in a higher degree of acid corrosion of the coating on the steel. At the same time, the un-grafted dithiosalicylic acid and aminophosphonic acid are not conducive to the formation of a dense hydrophobic film layer, reducing the corrosion resistance of the rust conversion layer. Judging from the test data, its adhesion also deteriorates.

[0102] Compared with Example 1, the properties of Example 8 all decline. The reason may be that there is no disulfide bond in the structure, which may lead to a decrease in the hydrophobicity of the rust conversion layer and its chemical adsorption to steel, and it cannot achieve self-repair when damaged by external forces. Therefore, both the adhesion and corrosion resistance of the coating decrease.

[0103] Compared with Example 1, when the coating on the steel plate surface of Comparative Example 1 was scraped off, a small amount of pitting corrosion was found on the substrate surface. The reason may be that only aminophosphonic acid is used, and there are too many phosphate groups, which may lead to a higher degree of damage to the steel, resulting in local over-corrosion. At the same time, without dithiosalicylic acid, a film layer with disulfide bonds cannot be formed in the rust conversion layer, and the rust conversion layer cannot achieve self-repair under external force, and its chemical adsorption to steel also decreases. Therefore, both the adhesion and corrosion resistance of the coating decrease significantly.

[0104] Compared with Example 1, the properties of Comparative Example 2 also all decline significantly. The reason may be that only dithiosalicylic acid is used. On the one hand, its carboxyl group may directly bond with the hydroxyl group on gallic acid, further reducing the penetration ability of gallic acid into the rust layer and the degree of rust conversion. The iron complex formed in the rust conversion layer may show a fault phenomenon, affecting the adhesion. On the other hand, too much dithiosalicylic acid may affect the effective contact of other groups with iron ions due to its large steric hindrance benzene ring structure, further affecting the degree of rust conversion. In addition, the absence of aminophosphoric acid results in the loss of the auxiliary rust conversion function of the phosphate group, and there is no dense film layer in the rust conversion layer. Therefore, the corrosion resistance of the coating also decreases significantly.

[0105] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A corrosion-resistant rust converter, characterized in that, The raw materials of the corrosion-resistant rust conversion agent include: 2 to 20 parts by weight of gallic acid, 0.5 to 6 parts by weight of phytic acid, 5 to 25 parts by weight of synergist, 4 to 23 parts by weight of glycerol, and 5 to 25 parts by weight of water; Among them, the raw materials of the synergist include aminophosphonic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide.

2. The corrosion-resistant rust conversion agent according to claim 1, wherein The raw materials of the corrosion-resistant rust conversion agent include: 4 to 15 parts by weight of gallic acid, 1 to 4 parts by weight of phytic acid, 7 to 22 parts by weight of synergist, 6 to 20 parts by weight of glycerol, and 6 to 21 parts by weight of water.

3. The corrosion-resistant rust converter according to claim 1 or 2, characterized in that, The synergist is prepared by the following method: Dissolve dithioglycolic acid, carbodiimide hydrochloride, and N-hydroxysuccinimide in tetrahydrofuran, then add aminophosphonic acid, and stir at 30°C to 60°C for 2 to 6 hours, concentrate, wash, and dry to obtain the synergist.

4. The corrosion-resistant rust converter according to claim 3, characterized in that, The molar ratio of the dithioglycolic acid to the aminophosphonic acid is 1:1 - 2.

5.

5. The corrosion-resistant rust converter according to claim 4, characterized in that, The molar ratio of the dithioglycolic acid to the aminophosphonic acid is 1:1.5 - 2.

2.

6. The corrosion-resistant rust conversion agent according to claim 1, characterized in that, The aminophosphonic acid is any one or more of 1-aminomethylphosphonic acid, 2-aminoethylphosphonic acid, 3-aminopropylphosphonic acid, 4-aminobutylphosphonic acid, 6-aminohexane phosphoric acid, (1-aminopentyl)phosphonic acid, (1-aminohexyl)phosphonic acid, (1-aminooctyl)phosphoric acid.

7. The corrosion-resistant rust converter according to claim 1, characterized in that, The weight of the carbodiimide hydrochloride accounts for 3% - 5% of the weight of the aminophosphonic acid.

8. The corrosion-resistant rust converter according to claim 1, characterized in that, The weight of the N-hydroxysuccinimide accounts for 5% - 10% of the weight of the aminophosphonic acid.

9. A preparation method of a corrosion-resistant rust converter, characterized in that, For preparing the corrosion-resistant rust conversion agent according to any one of claims 1 to 8, the preparation method includes: Mix the raw materials of the corrosion-resistant rust conversion agent evenly to obtain the corrosion-resistant rust conversion agent.

Images