Acrylic acid type rust conversion agent and preparation method thereof

Abstract

The invention discloses an acrylic acid type rust conversion agent and a preparation method thereof, and belongs to the technical field of metal surface treatment. The acrylic acid type rust conversion agent is prepared from the following raw materials: 50 to 60 parts of pure acrylic emulsion, 4 to 6 parts of cross-linking agent, 10 to 12 parts of rust conversion agent, 0.8 to 1.2 parts of defoaming agent, 1 to 1.2 parts of flatting agent, 2 to 3 parts of coalescing agent, 8 to 10 parts of nano silicon dioxide, 20 to 25 parts of deionized water and 0.1 to 0.3 part of N, N-dibenzylaniline. The preparation method of the cross-linking agent comprises the following steps: reacting amino-terminated silicon oil with perfluorobromooctane to obtain an intermediate 1, reacting with 10-bromo-1-decene to obtain an intermediate 2, and finally preparing the cross-linking agent under the action of formic acid and hydrogen peroxide. The prepared acrylic acid type rust conversion agent has good adhesive force and salt spray resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal surface treatment, in particular to an acrylic rust conversion agent and a preparation method thereof. BACKGROUND

[0002] With the development of modern industry, the research on corrosion protection of steel gradually attracts people's attention. In order to protect the steel components from rusting, the method of coating is often used. Before using the coating, thorough rust removal treatment must be carried out to ensure that the covering layer has good bonding force with the substrate. For the rust removal construction of large steel components, there are still many problems, such as large surface treatment range, complex structure, and many dead angles that cannot be completely removed, and these dead angles are just the source of the beginning of the coating peeling and the growth of rust. The rust conversion agent can be directly applied to the surface of the rusted substrate to passivate or convert the rust to lose activity. The current rust conversion agent has the problems of poor adhesion and insufficient corrosion resistance, which limits its application.

[0003] The Chinese invention patent with publication number CN114262884A discloses a phosphoric acid excited fly ash cementitious type rust conversion agent and a preparation method thereof. The raw materials are as follows in parts by weight: rust conversion agent 55.1-71.4 parts, cementitious material activator 33.1-42.8 parts, fly ash 50.3-64.9 parts, styrene-acrylate emulsion 91.5-103 parts, anhydrous ethanol 36.2-48.3 parts, deionized water 50.5-62.9 parts; the rust conversion agent includes hydroxyethylidene diphosphonic acid 17.9-25.1 parts, aluminum tripolyphosphate 37.2-46.3 parts; the cementitious material activator is phosphoric acid. The rust conversion agent prepared by the invention has good rust removal capacity and rust resistance, but its adhesion is poor. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide an acrylic rust conversion agent and a preparation method thereof.

[0005] To achieve the above-mentioned purpose, the present application realizes the following technical solutions: An acrylic rust conversion agent, comprising the following raw materials in parts by weight: pure acrylic emulsion 50-60 parts, crosslinking agent 4-6 parts, rust conversion agent 10-12 parts, defoaming agent 0.8-1.2 parts, leveling agent 1-1.2 parts, film-forming aid 2-3 parts, nano silicon dioxide 8-10 parts, deionized water 20-25 parts, N,N-dibenzyl aniline 0.1-0.3 parts; The crosslinking agent is prepared by the following method: S1: amino-terminated silicone oil reacts with perfluorooctyl bromide to generate intermediate 1, and the reaction equation is as follows:

[0006] S2: intermediate 1 reacts with 10-bromo-1-decene to generate intermediate 2; the reaction equation is shown as follows:

[0007] S3: intermediate 2 reacts with formic acid and hydrogen peroxide to generate a crosslinking agent; the reaction equation is shown as follows:

[0008] In step S1, the mass ratio of the terminal amino silicone oil to perfluorooctyl bromide is 1:(1-1.1).

[0009] In step S2, the mass ratio of intermediate 1 to 10-bromo-1-decene is (4.0-4.2):1.

[0010] In step S3, the mass ratio of intermediate 2 to formic acid is (16-18):1.

[0011] The rust converter is prepared by the following method: N1: 2-aminopyridine reacts with oleic acid chloride to generate intermediate A; the reaction equation is shown as follows:

[0012] N2: intermediate A reacts with formic acid and hydrogen peroxide to generate intermediate B; the reaction equation is shown as follows:

[0013] N3: intermediate B reacts with gallic acid to generate intermediate C; the reaction equation is shown as follows:

[0014] N4: intermediate C reacts with epichlorohydrin to generate a rust converter; the reaction equation is shown as follows:

[0015] In step N1, the molar ratio of 2-aminopyridine to oleic acid chloride is 1:1.1; in step N2, the molar ratio of intermediate A to formic acid is 1:1.4; in step N3, the molar ratio of intermediate B to gallic acid is 1.2:1; in step N4, the molar ratio of intermediate C to epichlorohydrin is 1:1.05.

[0016] The defoaming agent is one of BYK-066N and DF-680.

[0017] The leveling agent is one of BYK-358N and BYK-333.

[0018] The film forming aid is dodecanol ester.

[0019] A preparation method of an acrylic rust conversion agent, comprising the following steps: S1: take the following by weight parts: pure acrylic emulsion 50-60 parts, crosslinking agent 4-6 parts, rust conversion agent 10-12 parts, defoaming agent 0.8-1.2 parts, leveling agent 1-1.2 parts, film forming aid 2-3 parts, nano-silica 8-10 parts, deionized water 20-25 parts, N,N-dibenzyl aniline 0.1-0.3 parts; S2: the pure acrylic emulsion, crosslinking agent, rust conversion agent, defoaming agent, leveling agent, film forming aid, nano-silica, deionized water, N,N-dibenzyl aniline are stirred and mixed uniformly, cooled to room temperature, filtered through a filter screen, and an acrylic rust conversion agent is obtained.

[0020] Due to the above technical scheme, the beneficial effects of the present application include: The acrylic rust conversion agent prepared by the present application has good adhesion and salt mist resistance. The prepared crosslinking agent enhances its adhesion by forming covalent bonds and reducing surface tension, and increases its salt mist resistance by introducing a fluorocarbon chain. The prepared rust conversion agent enhances its passivation ability by forming stable coordination bonds. DETAILED DESCRIPTION

[0021] The present application will be further described below in conjunction with examples, but the present application is not limited to these examples.

[0022] Example 1: Preparation of a crosslinking agent S1: 600ml of isopropyl alcohol, 40g of amino-terminated silicone oil, 40g of perfluorooctane bromide and 12g of potassium carbonate are added to a reaction kettle, stirred and mixed uniformly, heated to 60℃, reacted for 10h, cooled to room temperature, filtered, and distilled at 55℃ under reduced pressure for 2h to obtain intermediate 1; S2: 700ml of tetrahydrofuran, 80g of intermediate 1, 20g of 10-bromo-1-decene and 12g of potassium carbonate are added to a reaction kettle, stirred and mixed uniformly, heated to reflux, reacted for 15h, cooled to room temperature, washed with saturated brine three times (200ml each time), dried with 20g of anhydrous magnesium sulfate, filtered, and distilled at 50℃ under reduced pressure for 2h to obtain intermediate 2; S3: 500ml of DMF, 80g of intermediate 2 and 3g of strong acid cation exchange resin are added to a reaction kettle, stirred and mixed uniformly, heated to 50℃, and a mixed solution of 5g of formic acid and 18g of 30wt% hydrogen peroxide is added dropwise, the dropping is completed in 20min, reacted for 10h, cooled to room temperature, filtered, and 800ml of deionized water is slowly added to the filtrate while stirring to precipitate a solid, filtered, washed with deionized water three times (200ml each time), and vacuum dried at 60℃ for 24h to obtain a crosslinking agent.

[0023] Example 2 Preparation of crosslinking agent: S1: 600 ml of isopropyl alcohol, 40 g of amino-terminated silicone oil, 42 g of perfluorooctyl bromide and 12 g of potassium carbonate were added into a reaction kettle, stirred and mixed uniformly, heated to 70°C, reacted for 8 h, cooled to room temperature, filtered, distilled at 55°C under reduced pressure for 2 h, to obtain intermediate 1; S2: 700 ml of tetrahydrofuran, 82 g of intermediate 1, 20 g of 10-bromo-1-decene and 12 g of potassium carbonate were added into a reaction kettle, stirred and mixed uniformly, heated to reflux, reacted for 18 h, cooled to room temperature, washed with saturated brine three times (200 ml each time), dried with 20 g of anhydrous magnesium sulfate, filtered, distilled at 50°C under reduced pressure for 2 h, to obtain intermediate 2; S3: 500 ml of DMF, 85 g of intermediate 2 and 3 g of strong acid cation exchange resin were added into a reaction kettle, stirred and mixed uniformly, heated to 55°C, a mixed solution of 5 g of formic acid and 18 g of 30 wt% hydrogen peroxide was slowly added dropwise, the dropping was completed in 60 min, reacted for 8 h, cooled to room temperature, filtered, 800 ml of deionized water was slowly added into the filtrate to stir and precipitate the solid, filtered, washed with deionized water three times (200 ml each time), vacuum dried at 60°C for 24 h, to obtain the crosslinking agent.

[0024] Example 3 Preparation of crosslinking agent: S1: 600 ml of isopropyl alcohol, 40 g of amino-terminated silicone oil, 42 g of perfluorooctyl bromide and 12 g of potassium carbonate were added into a reaction kettle, stirred and mixed uniformly, heated to 70°C, reacted for 8 h, cooled to room temperature, filtered, distilled at 55°C under reduced pressure for 2 h, to obtain intermediate 1; S2: 700 ml of tetrahydrofuran, 82 g of intermediate 1, 20 g of 10-bromo-1-decene and 12 g of potassium carbonate were added into a reaction kettle, stirred and mixed uniformly, heated to reflux, reacted for 18 h, cooled to room temperature, washed with saturated brine three times (200 ml each time), dried with 20 g of anhydrous magnesium sulfate, filtered, distilled at 50°C under reduced pressure for 2 h, to obtain intermediate 2; S3: 500 ml of DMF, 85 g of intermediate 2 and 3 g of strong acid cation exchange resin were added into a reaction kettle, stirred and mixed uniformly, heated to 55°C, a mixed solution of 5 g of formic acid and 18 g of 30 wt% hydrogen peroxide was slowly added dropwise, the dropping was completed in 60 min, reacted for 8 h, cooled to room temperature, filtered, 800 ml of deionized water was slowly added into the filtrate to stir and precipitate the solid, filtered, washed with deionized water three times (200 ml each time), vacuum dried at 60°C for 24 h, to obtain the crosslinking agent.

[0025] Example 4 Preparation of rust converter: N1: 200 ml of dichloromethane, 0.11 mol of oleic acid chloride, 0.10 mol of pyridine were added into a reaction kettle, stirred and mixed, 80 ml of 0.1 mol 2-aminopyridine dichloromethane solution was added dropwise at 0°C, 30 min dropwise, room temperature reaction for 6 h, washed with deionized water three times (100 ml each time), dried with 8 g of anhydrous magnesium sulfate, filtered, and distilled at 30°C under reduced pressure for 1 h to obtain intermediate A; the nuclear magnetic resonance hydrogen spectrum data are as follows: 1 H NMR (300 MHz, Chloroform- d ) δ 9.01 (s, 1H), 8.30 (dd, J = 4.3, 1.7 Hz, 1H), 7.80 (ddd, J = 7.7, 7.0, 1.6 Hz, 1H), 7.53 (dd, J = 7.7,1.4 Hz, 1H), 7.16 - 7.06 (m, 1H), 5.39 - 5.27 (m, 2H), 2.40 (t, J = 8.3 Hz,2H), 2.10 - 1.96 (m, 4H), 1.77 - 1.61 (m, 2H), 1.40 - 1.20 (m, 20H), 0.98 -0.82 (m, 3H); N2: 300 ml of DMF, 0.1 mol of intermediate A and 3.5 g of strong acid cation exchange resin were added into a reaction kettle, stirred and mixed, heated to 60°C, 0.14 mol of formic acid and 23.8 g of 30wt% hydrogen peroxide were added dropwise, 20 min dropwise, reaction for 7 h, cooled to room temperature, filtered, distilled at 60°C under reduced pressure for 3 h, washed with deionized water three times (150 ml each time), vacuum dried at 60°C for 12 h to obtain intermediate B; the nuclear magnetic resonance hydrogen spectrum data are as follows: 1 H NMR (300 MHz, Chloroform- d ) δ 9.01 (s,1H), 8.30 (dd, J = 4.3, 1.7 Hz, 1H), 7.80 (ddd, J = 7.7, 7.0, 1.6 Hz, 1H),7.53 (dd, J = 7.7, 1.4 Hz, 1H), 7.16 - 7.06 (m, 1H), 3.10 (t, J = 4.3 Hz,2H), 2.40 (t, J = 8.3 Hz, 2H), 1.87 - 1.19 (m, 26H), 0.97 - 0.82 (m, 3H); N3: 400 ml of toluene, 50 ml of methanol, 0.1 mol of gallic acid and 0.01 mol of triphenylphosphine were added into a reaction kettle, stirred and mixed, heated to 60°C, 0.12 mol of intermediate B was added in batches (divided into 5 batches, each batch interval 15 min), reacted for 10 h, cooled to room temperature, washed with 200 ml of 5wt% NaOH solution, 150 ml of deionized water, dried with 15 g of anhydrous magnesium sulfate, filtered, and distilled at 60°C under reduced pressure for 2 h to obtain intermediate C; its nuclear magnetic resonance hydrogen spectrum data are as follows: 1 H NMR (300 MHz, Chloroform- d ) δ 9.01 (s, 1H), 8.30 (dd, J = 4.3, 1.7 Hz, 1H), 7.80 (ddd, J =7.7, 7.0, 1.6 Hz, 1H), 7.53 (dd, J = 7.7, 1.4 Hz, 1H), 7.16 - 7.04 (m, 5H),5.33 (s, 1H), 4.88 (dt, J = 6.9, 6.1 Hz, 1H), 3.71 (qd, J = 6.7, 5.9 Hz, 1H),3.25 (d, J = 5.9 Hz, 1H), 2.40 (t, J = 8.3 Hz, 2H), 1.89 - 1.18 (m, 26H),0.97 - 0.82 (m, 3H); N4: 500 ml of DMF, 0.1 mol of intermediate C were added into a reaction kettle under nitrogen protection, stirred and mixed, 0.01 mol of tetraethylammonium bromide was added, heated to 85°C, 0.11 mol of epichlorohydrin was slowly added, and the dropping was completed after 25 min. Reaction for 4 h, the temperature was lowered to 70°C, 10 g of 40wt% NaOH solution was added and stirred for 1 h, cooled to room temperature, distilled at 70°C under reduced pressure for 3 h, purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate V / V=5:1), rotary evaporated at 50°C for 3 h to obtain the rust converter; its nuclear magnetic resonance hydrogen spectrum data are as follows: 1 HNMR (300 MHz, Chloroform- d) δ 9.01 (s, 1H), 8.30 (dd, J = 4.3, 1.7 Hz, 1H), 7.80 (ddd, J = 7.7, 7.0, 1.7 Hz, 1H), 7.53 (dd, J = 7.7, 1.4 Hz, 1H), 7.44(s, 1H), 7.11 (ddd, J = 7.0, 3.3, 1.6 Hz, 3H), 6.68 (s, 1H), 4.88 (dt, J =6.9, 6.1 Hz, 1H), 4.20 (ddd, J = 75.8, 11.5, 3.3 Hz, 2H), 3.71 (qd, J = 6.7,5.9 Hz, 1H), 3.60 (p, J = 3.1 Hz, 1H), 3.29 - 2.88 (m, 3H), 2.40 (t, J = 8.3Hz, 2H), 1.89 - 1.14 (m, 26H), 0.98 - 0.82 (m, 3H)。

[0026] Example 5 Preparation of acrylic rust conversion agent: S1: Weigh: pure acrylic emulsion 500g, crosslinking agent (prepared in example 1) 40g, rust conversion agent (prepared in example 4) 100g, defoaming agent BYK-066N 8g, leveling agent BYK-358N 10g, film forming aid dodecanol ester 20g, nano silicon dioxide 80g, deionized water 200g, N,N-dibenzyl aniline 1g; S2: Put pure acrylic emulsion, crosslinking agent, rust conversion agent, defoaming agent BYK-066N, leveling agent BYK-358N, film forming aid dodecanol ester, nano silicon dioxide, deionized water, N,N-dibenzyl aniline into the reaction kettle, stir, heat to 60°C, stir at 800r / min for 40min, cool to room temperature, filter with 350 mesh filter screen, get acrylic rust conversion agent.

[0027] Example 6 Preparation of acrylic rust conversion agent: S1: Weigh: pure acrylic emulsion 550g, crosslinking agent (prepared in example 2) 50g, rust conversion agent (prepared in example 4) 110g, defoaming agent BYK-066N 10g, leveling agent BYK-333 11g, film forming aid dodecanol ester 25g, nano silicon dioxide 90g, deionized water 240g, N,N-dibenzyl aniline 2g; S2: pure acrylic emulsion, crosslinking agent, rust converter, defoamer BYK-066N, leveling agent BYK-333, film forming aid dodecanol ester, nano silicon dioxide, deionized water, N, N-dibenzyl aniline were added to the reaction kettle, stirring, heating to 65℃, stirring at 800r / min for 35min, cooling to room temperature, using 350 mesh filter screen for filtration, to obtain the acrylic rust conversion agent.

[0028] Example 7 Preparation of acrylic rust conversion agent: S1: weighing: pure acrylic emulsion 600g, crosslinking agent (prepared in example 3) 60g, rust converter (prepared in example 4) 120g, defoamer DF-680 12g, leveling agent BYK-333 12g, film forming aid dodecanol ester 30g, nano silicon dioxide 100g, deionized water 250g, N, N-dibenzyl aniline 3g; S2: pure acrylic emulsion, crosslinking agent, rust converter, defoamer DF-680, leveling agent BYK-333, film forming aid dodecanol ester, nano silicon dioxide, deionized water, N, N-dibenzyl aniline were added to the reaction kettle, stirring, heating to 70℃, stirring at 800r / min for 30min, cooling to room temperature, using 350 mesh filter screen for filtration, to obtain the acrylic rust conversion agent.

[0029] Comparative example 1 The raw material ratio and preparation method of the acrylic rust conversion agent are basically the same as those of example 6, except that the crosslinking agent (prepared in example 2) added in the component is replaced by the same weight of intermediate 2 (prepared in example 2 step S2).

[0030] Comparative example 2 The raw material ratio and preparation method of the acrylic rust conversion agent are basically the same as those of example 6, except that the crosslinking agent (prepared in example 2) added in the component is replaced by the same weight of the crosslinking agent prepared by the following method: The preparation method of the crosslinking agent is basically the same as that of example 2, except that 10-bromo-1-decene in step S2 is replaced by the same mass of 3-bromopropylene.

[0031] Comparative example 3 The raw material ratio and preparation method of the acrylic rust conversion agent are basically the same as those of example 6, except that the crosslinking agent (prepared in example 2) added in the component is replaced by the same weight of the crosslinking agent prepared by the following method: S1: 600 ml of tetrahydrofuran, 45.8 g of amino-terminated silicone oil, and 20 g of 10-bromo-1-decene and 12 g of potassium carbonate were added to a reaction kettle, stirred and mixed, warmed to reflux, reacted for 18 h, cooled to room temperature, washed with saturated brine three times (200 ml each time), dried with 20 g of anhydrous magnesium sulfate, filtered, and distilled at 50°C under reduced pressure for 2 h to obtain an intermediate; S2: 500 ml of DMF, 60 g of the intermediate, and 3 g of strong acid cation exchange resin were added to a reaction kettle, stirred and mixed, warmed to 55°C, and a mixed solution of 5 g of formic acid and 18 g of 30 wt% hydrogen peroxide was added dropwise. After 20 min of dropwise addition, the reaction was carried out for 8 h, cooled to room temperature, filtered, and the filtrate was poured into 800 ml of deionized water and stirred to precipitate a solid, filtered, washed with deionized water three times (200 ml each time), and dried at 60°C under vacuum for 24 h to obtain a crosslinking agent.

[0032] Comparative Example 4 The raw material ratio and preparation method of the acrylic rust converter were basically the same as in Example 6, except that the rust converter (prepared in Example 4) added in the component was replaced with an equal weight of intermediate C (prepared in Example 4, step N3).

[0033] Comparative Example 5 The raw material ratio and preparation method of the acrylic rust converter were basically the same as in Example 6, except that the rust converter (prepared in Example 4) added in the component was replaced with an equal weight of a rust converter prepared by the following method: The preparation method of the rust converter was basically the same as in Example 4, except that the amount of epichlorohydrin added in step N4 was replaced with 0.22 mol.

[0034] Comparative Example 6 The raw material ratio and preparation method of the acrylic rust converter were basically the same as in Example 6, except that the rust converter (prepared in Example 4) added in the component was replaced with an equal weight of a rust converter prepared by the following method: The preparation method of the rust converter was basically the same as in Example 4, except that 2-aminopyridine in step N1 was replaced with an equal molar amount of 4-aminopyridine.

[0035] The pure acrylic emulsion used in the present application is S-05 pure acrylic emulsion with a solid content of 48 wt%, produced by Jiangsu Shengda New Material Technology Co., Ltd.; the nano-silicon dioxide is of the type DK-SiO2-30, produced by Suzhou Meilbang Nanometer Material Co., Ltd., with an average particle size of 30 nm; the amino-terminated silicone oil is of the type Cheersil 8110, with an amine group content of 2 mmol / g, produced by Suzhou Qitian New Material Co., Ltd.; the strong acid cation exchange resin is a polymer of divinylbenzene and sodium vinylbenzenesulfonate, with a brand name of Amberlite® IMAC HP1110 resin.

[0036] Preparation of rusted steel plate: Q235 steel was cut into a size of 100 mm x 150 mm x 1 mm as a metal substrate, and was cleaned with 300 ml of anhydrous ethanol and 300 ml of acetone by ultrasonic (50 Hz) for 20 min, and was dried at 80°C in a vacuum drying oven for 2 h; the cleaned metal substrate was placed in a salt spray test chamber for neutral salt spray testing, and the test was performed in accordance with GB / T10125-2012, a 5 wt% NaCl solution was sprayed in the test chamber, the temperature of the test chamber was set to 35°C, and the rusted iron sheet was taken out after 48 h, and was dried in a vacuum drying oven at 80°C for 2 h to obtain a rusted steel plate.

[0037] Preparation of samples: the acrylic rust conversion agent prepared in Examples 5-7 and Comparative Examples 1-6 was sprayed on the rusted steel plate using a W-71-G type spray gun (spraying pressure was 0.3 MPa, spraying distance was 200 mm, and spraying was performed 3 times) to prepare a smooth and uniform paint film, and the sample was dried at 25°C for 7 days to obtain a sample. The sample was subjected to adhesion and salt spray resistance tests, and the test results are shown in Table 1.

[0038] Adhesion test: the test was performed in accordance with the standard of GB / T 9286-1998, a grid marker was used to draw 100 1 mm x 1 mm squares on the ink film layer of the sample, and then a transparent pressure-sensitive adhesive tape was firmly attached and quickly peeled off to test the adhesion grade.

[0039] Salt spray resistance test: the test was performed in accordance with the standard of GB / T 1771-2007, the sample was placed in a test chamber, a 5 wt% NaCl solution was sprayed, the temperature of the test chamber was set to 35°C, and the time taken for the sample to blister was recorded.

[0040] Table 1 Performance test data table

[0041] As can be seen from Table 1, Examples 5, 6 and 7, the acrylic rust conversion agent prepared in the present application has good adhesion and salt spray resistance.

[0042] The crosslinking agent prepared by the present application contains fluorocarbon chain, siloxane segment and epoxy group, wherein the epoxy group can undergo ring-opening reaction with the carboxyl group (-COOH) of pure acrylic emulsion to form stable covalent bond, effectively improving the adhesion of the acrylic rust conversion agent; the fluorocarbon chain has extremely low surface energy, endowing the coating surface with excellent hydrophobic and oleophobic properties, effectively slowing down the penetration rate of corrosion medium to the metal substrate / rust layer interface and improving the salt spray resistance; the siloxane segment can reduce the surface tension of the acrylic rust conversion agent system, improve its wettability and spreading ability on the complex rust surface, help it to more closely wrap the rust products and penetrate into the rust layer micropores, enhance the physical anchoring effect and further improve the adhesion. In comparison, the chain length of the epoxy group connected with the siloxane in the crosslinking agent used in Comparative Example 2 is shorter, affecting the crosslinking effect and leading to the decrease of adhesion.

[0043] The epoxy group in the rust conversion agent prepared by the present application can undergo ring-opening reaction with the carboxyl group (-COOH) in the pure acrylic emulsion to form stable covalent bond, effectively improving the adhesion of the acrylic rust conversion agent; the two phenolic hydroxyl groups at adjacent positions in the rust conversion agent can form stable chelate with Fe 3+ in the iron rust, cover the surface of the metal substrate and enhance the passivation effect; the pyridine nitrogen atom in the rust conversion agent can provide lone pair of electrons to form stable coordination bond with Fe 3+ in the iron rust, and the amide bond adjacent to the pyridine nitrogen atom can form hydrogen bond network with the hydroxyl oxygen in the iron rust, further enhancing the interfacial bonding strength and improving the salt spray resistance. The rust conversion agent used in Comparative Example 5 has more epoxy groups and less amount of phenolic hydroxyl groups, reducing its ability to form chelate and lowering the salt spray resistance.

[0044] The above is only the preferred embodiment of the present application and is not used to limit the present application; but for ordinary skilled in the art without departing from the scope of the technical solutions of the present application, some changes, modifications and equivalent changes of the above disclosed technical contents can be made, which are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above embodiments according to the essential technology of the present application are still within the protection scope of the technical solutions of the present application.

Claims

1. An acrylic rust converter, characterized by, The raw materials include the following weight parts: Pure acrylic emulsion 50-60 parts, crosslinking agent 4-6 parts, rust conversion agent 10-12 parts, defoaming agent 0.8-1.2 parts, leveling agent 1-1.2 parts, film forming aid 2-3 parts, nano silicon dioxide 8-10 parts, deionized water 20-25 parts, N,N-dibenzyl aniline 0.1-0.3 parts; The crosslinking agent is prepared by the following method: S1: the terminal amino silicone oil reacts with perfluorooctyl bromide to generate intermediate 1, S2: intermediate 1 reacts with 10-bromo-1-decene to generate intermediate 2, S3: intermediate 2 generates crosslinking agent under the action of formic acid and hydrogen peroxide; The rust conversion agent is prepared by the following method: N1: 2-aminopyridine reacts with oleic acid chloride to generate intermediate A, N2: intermediate A generates intermediate B under the action of formic acid and hydrogen peroxide, N3: intermediate B reacts with gallic acid to generate intermediate C, N4: intermediate C reacts with epichlorohydrin to generate the rust conversion agent.

2. The rust converter according to claim 1, wherein In step S1, the mass ratio of the terminal amino silicone oil to perfluorooctyl bromide is 1:(1-1.1).

3. The rust converter according to claim 1, wherein In step S2, the mass ratio of intermediate 1 to 10-bromo-1-decene is (4.0-4.2):

1.

4. The rust converter according to claim 1, wherein In step S3, the mass ratio of intermediate 2 to formic acid is (16-18):

1.

5. The rust converter according to claim 1, wherein In step N1, the molar ratio of 2-aminopyridine to oleic acid chloride is 1:1.

1.

6. The rust converter according to claim 1, wherein In step N2, the molar ratio of intermediate A to formic acid is 1:1.

4.

7. The rust converter according to claim 1, wherein In step N3, the molar ratio of intermediate B to gallic acid is 1.2:

1.

8. The rust converter according to claim 1, wherein In step N4, the molar ratio of intermediate C to epichlorohydrin is 1:1.

05.

9. The rust converter according to claim 1, wherein The defoaming agent is one of BYK-066N and DF-680.

10. The rust converter according to claim 1, wherein The leveling agent is one of BYK-358N and BYK-333.

11. The rust converter according to claim 1, wherein The film forming aid is dodecanol ester.

12. A method of preparing the rust conversion agent according to any one of claims 1 to 11, characterized in that, The method includes the following steps: S1: the following are weighed by weight parts: pure acrylic emulsion 50-60 parts, crosslinking agent 4-6 parts, rust conversion agent 10-12 parts, defoaming agent 0.8-1.2 parts, leveling agent 1-1.2 parts, film forming aid 2-3 parts, nano silicon dioxide 8-10 parts, deionized water 20-25 parts, N,N-dibenzyl aniline 0.1-0.3 parts; S2: the pure acrylic emulsion, the crosslinking agent, the rust conversion agent, the defoaming agent, the leveling agent, the film forming aid, the nano silicon dioxide, the deionized water, and the N,N-dibenzyl aniline are stirred and mixed uniformly, cooled to room temperature, filtered through a filter screen, and the acrylic rust conversion agent is obtained.

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