An acrylic rust conversion agent and a method for preparing the same

Abstract

The application discloses an acrylic rust conversion agent and a preparation method thereof, and belongs to the technical field of metal surface treatment. The acrylic rust conversion agent comprises the following raw materials: 50-60 parts of pure acrylic emulsion, 4-6 parts of a crosslinking agent, 10-12 parts of a rust conversion agent, 0.8-1.2 parts of a defoaming agent, 1-1.2 parts of a leveling agent, 2-3 parts of a film-forming aid, 8-10 parts of nano silicon dioxide, 20-25 parts of deionized water, and 0.1-0.3 parts of N, N-dibenzyl aniline. The crosslinking agent is first prepared by reacting an amino-terminated silicone oil with perfluorooctyl bromide to obtain an intermediate 1, then reacting the intermediate 1 with 10-bromo-1-decene to obtain an intermediate 2, and finally prepared under the action of formic acid and hydrogen peroxide. The acrylic rust conversion agent prepared by the application has good adhesion and salt fog resistance.

Description

Technical Field

[0001] This invention relates to the field of metal surface treatment technology, specifically to an acrylic rust converter and its preparation method. Background Technology

[0002] With the development of modern industry, research on the corrosion prevention of steel has gradually attracted attention. To protect steel components from rust, coatings are often used. Before applying a coating, thorough rust removal is necessary to ensure good adhesion between the coating and the substrate. However, this still presents many challenges for rust removal of large steel components, such as the large surface treatment area, complex structure, and the inability to completely remove rust from many hard-to-reach areas. These hard-to-reach areas are precisely the source of coating peeling and the continued growth and expansion of rust. Rust converters can be directly applied to the surface of rusted substrates, passivating or converting the rust and rendering it inactive. Currently, rust converters suffer from poor adhesion and insufficient corrosion resistance, limiting their application.

[0003] Chinese invention patent CN114262884A discloses a phosphoric acid-activated fly ash cementitious rust converter and its preparation method. The raw materials, by weight, are: 55.1-71.4 parts rust converter, 33.1-42.8 parts cementitious material activator, 50.3-64.9 parts fly ash, 91.5-103 parts styrene-acrylate emulsion, 36.2-48.3 parts anhydrous ethanol, and 50.5-62.9 parts deionized water. The rust converter includes 17.9-25.1 parts hydroxyethylidene diphosphonic acid and 37.2-46.3 parts aluminum tripolyphosphate; the cementitious material activator is phosphoric acid. The rust converter prepared by this invention has good rust removal and rust prevention capabilities, but its adhesion is poor. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide an acrylic rust converter and its preparation method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An acrylic rust converter comprises the following raw materials in parts by weight:

[0007] 50-60 parts pure acrylic emulsion, 4-6 parts crosslinking agent, 10-12 parts rust-reducing agent, 0.8-1.2 parts defoamer, 1-1.2 parts leveling agent, 2-3 parts film-forming aid, 8-10 parts nano silica, 20-25 parts deionized water, and 0.1-0.3 parts N,N-dibenzylaniline;

[0008] The crosslinking agent is prepared by the following method:

[0009] S1: The reaction of amino-terminated silicone oil with perfluorooctane produces intermediate 1, and the reaction equation is shown below:

[0010]

[0011] S2: Intermediate 1 reacts with 10-bromo-1-decene to generate intermediate 2; the reaction equation is shown below:

[0012]

[0013] S3: Intermediate 2 reacts with formic acid and hydrogen peroxide to form a crosslinking agent, as shown in the following reaction equation:

[0014]

[0015] In step S1, the mass ratio of the terminal amino silicone oil to perfluorobromooctane is 1:(1-1.1).

[0016] In step S2, the mass ratio of intermediate 1 to 10-bromo-1-decene is (4.0-4.2):1.

[0017] In step S3, the mass ratio of intermediate 2 to formic acid is (16-18):1.

[0018] The rust-removing agent is prepared by the following method:

[0019] N1: 2-Aminopyridine reacts with oleic acid chloride to generate intermediate A, and the reaction equation is shown below:

[0020]

[0021] N2: Intermediate A reacts with formic acid and hydrogen peroxide to form intermediate B, as shown in the following schematic equation:

[0022]

[0023] N3: Intermediate B reacts with gallic acid to generate intermediate C, and the reaction equation is shown below:

[0024]

[0025] N4: Intermediate C reacts with epichlorohydrin to generate a rust-reducing agent, and the reaction equation is shown below:

[0026]

[0027] 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.

[0028] The defoamer is one of BYK-066N and DF-680.

[0029] The leveling agent is one of BYK-358N and BYK-333.

[0030] The film-forming aid is a dodecyl alcohol ester.

[0031] A method for preparing an acrylic rust converter includes the following steps:

[0032] S1: Weigh the following by weight: 50-60 parts pure acrylic emulsion, 4-6 parts crosslinking agent, 10-12 parts rust-reducing agent, 0.8-1.2 parts defoamer, 1-1.2 parts leveling agent, 2-3 parts film-forming aid, 8-10 parts nano silica, 20-25 parts deionized water, and 0.1-0.3 parts N,N-dibenzylaniline;

[0033] S2: Pure acrylic emulsion, crosslinking agent, rust converter, defoamer, leveling agent, film-forming aid, nano silica, deionized water, and N,N-dibenzylaniline are heated and stirred until homogeneous, cooled to room temperature, and filtered through a filter screen to obtain an acrylic rust converter.

[0034] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0035] The acrylic rust converter prepared by this invention has good adhesion and salt spray resistance because: the prepared crosslinking agent enhances its adhesion by forming covalent bonds and reducing surface tension, and increases its salt spray resistance by introducing fluorocarbon chains; the prepared rust converter enhances its passivation ability by forming stable coordination bonds. Detailed Implementation

[0036] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0037] Example 1: Preparation of crosslinking agent:

[0038] S1: Add 600ml isopropanol, 40g amino-terminated silicone oil, 40g perfluorooctane and 12g potassium carbonate to the reaction vessel, stir and mix well, heat to 60℃, react for 10h, cool to room temperature, filter, and distill under reduced pressure at 55℃ for 2h to obtain intermediate 1.

[0039] S2: Add 700 ml of tetrahydrofuran, 80 g of intermediate 1, 20 g of 10-bromo-1-decene and 12 g of potassium carbonate to a reaction vessel, stir and mix well, heat to reflux, react for 15 h, cool to room temperature, wash three times with saturated brine (200 ml each time), dry with 20 g of anhydrous magnesium sulfate, filter, and distill under reduced pressure at 50 °C for 2 h to obtain intermediate 2;

[0040] S3: Add 500ml DMF, 80g intermediate 2 and 3g strong acid cation exchange resin to the reactor, stir and mix well, heat to 50℃, add 5g formic acid and 18g 30wt% hydrogen peroxide solution dropwise, the addition is completed in 20min, react for 10h, cool to room temperature, filter, slowly add 800ml deionized water to the filtrate and stir to precipitate solid, filter, wash three times with deionized water (200ml each time), vacuum dry at 60℃ for 24h to obtain crosslinking agent.

[0041] Example 2: Preparation of crosslinking agent:

[0042] S1: Add 600ml isopropanol, 40g amino-terminated silicone oil, 42g perfluorobromooctane and 12g potassium carbonate to the reaction vessel, stir and mix well, heat to 70℃, react for 8h, cool to room temperature, filter, distill under reduced pressure at 55℃ for 2h to obtain intermediate 1.

[0043] S2: Add 700 ml of tetrahydrofuran, 82 g of intermediate 1, 20 g of 10-bromo-1-decene and 12 g of potassium carbonate to a reaction vessel, stir and mix well, heat to reflux, react for 18 h, cool to room temperature, wash three times with saturated brine (200 ml each time), dry with 20 g of anhydrous magnesium sulfate, filter, and distill under reduced pressure at 50 °C for 2 h to obtain intermediate 2;

[0044] S3: Add 500ml DMF, 85g intermediate 2 and 3g strong acid cation exchange resin to the reactor, stir and mix well, heat to 55℃, slowly add 5g formic acid and 18g 30wt% hydrogen peroxide solution dropwise, the addition is completed in 60min, react for 8h, cool to room temperature, filter, slowly add 800ml deionized water to the filtrate and stir to precipitate solid, filter, wash three times with deionized water (200ml each time), vacuum dry at 60℃ for 24h to obtain crosslinking agent.

[0045] Example 3: Preparation of crosslinking agent:

[0046] S1: Add 600ml isopropanol, 40g amino-terminated silicone oil, 44g perfluorobromooctane and 12g potassium carbonate to the reaction vessel, stir and mix well, heat to 80℃, react for 6h, cool to room temperature, filter, distill under reduced pressure at 55℃ for 2h to obtain intermediate 1.

[0047] S2: Add 700 ml of tetrahydrofuran, 84 g of intermediate 1, 20 g of 10-bromo-1-decene and 12 g of potassium carbonate to a reaction vessel, stir and mix well, heat to reflux, react for 20 h, cool to room temperature, wash three times with saturated brine (200 ml each time), dry with 20 g of anhydrous magnesium sulfate, filter, and distill under reduced pressure at 50 °C for 2 h to obtain intermediate 2;

[0048] S3: Add 500ml DMF, 90g intermediate 2 and 3g strong acid cation exchange resin to the reactor, stir and mix well, heat to 60℃, add 5g formic acid and 18g 30wt% hydrogen peroxide solution dropwise, the addition is completed in 20min, react for 7h, cool to room temperature, filter, slowly add 800ml deionized water to the filtrate and stir to precipitate solid, filter, wash three times with deionized water (200ml each time), vacuum dry at 60℃ for 24h to obtain crosslinking agent.

[0049] Example 4: Preparation of rust-removing agent:

[0050] N1: 200 ml of dichloromethane, 0.11 mol of oleic acid chloride, and 0.10 mol of pyridine were added to a reaction vessel and stirred until well mixed. 80 ml of a dichloromethane solution containing 0.1 mol of 2-aminopyridine was added dropwise at 0 °C over 30 min. The reaction was allowed to proceed at room temperature for 6 h. The mixture was washed three times with deionized water (100 ml each time), dried over 8 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 30 °C for 1 h to obtain intermediate A. Its 1H NMR 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);

[0051] N2: Add 300 ml DMF, 0.1 mol intermediate A, and 3.5 g strong acid cation exchange resin to a reaction vessel, stir and mix well, heat to 60 °C, and dropwise add a mixed solution of 0.14 mol formic acid and 23.8 g 30 wt% hydrogen peroxide over 20 min. React for 7 h, cool to room temperature, filter, distill under reduced pressure at 60 °C for 3 h, wash three times with deionized water (150 ml each time), and dry under vacuum at 60 °C for 12 h to obtain intermediate B; its 1H NMR 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);

[0052] N3: 400 ml toluene, 50 ml methanol, 0.1 mol gallic acid, and 0.01 mol triphenylphosphine were added to a reaction vessel and stirred until homogeneous. The mixture was heated to 60 °C, and 0.12 mol of intermediate B was added in 5 batches (15 min apart). The reaction was allowed to proceed for 10 h, and the mixture was cooled to room temperature. The mixture was washed successively with 200 ml of 5 wt% NaOH solution and 150 ml of deionized water, dried over 15 g of anhydrous magnesium sulfate, filtered, and distilled under reduced pressure at 60 °C for 2 h to obtain intermediate C. Its 1H NMR 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);

[0053] N4: Under nitrogen protection, 500 ml of DMF and 0.1 mol of intermediate C were added to the reaction vessel and stirred until homogeneous. 0.01 mol of tetraethylammonium bromide was added, and the mixture was heated to 85 °C. 0.11 mol of epichlorohydrin was slowly added dropwise over 25 min. The reaction was allowed to proceed for 4 h, then cooled to 70 °C. 10 g of 40 wt% NaOH solution was added and stirred for 1 h. The mixture was then cooled to room temperature and distilled under reduced pressure at 70 °C for 3 h. The resulting product was purified by silica gel column chromatography (eluent: petroleum ether / ethyl acetate V / V = 5:1) and rotary evaporated at 50 °C for 3 h to obtain the rust-transforming agent. Its 1H NMR 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, 1.7 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 =8.3 Hz, 2H), 1.89 - 1.14 (m, 26H), 0.98 - 0.82 (m, 3H).

[0054] Example 5: Preparation of acrylic rust converter:

[0055] S1: Weigh out: 500g of pure acrylic emulsion, 40g of crosslinking agent (prepared in Example 1), 100g of rust-reducing agent (prepared in Example 4), 8g of defoamer BYK-066N, 10g of leveling agent BYK-358N, 20g of film-forming aid dodecyl alcohol ester, 80g of nano silica, 200g of deionized water, and 1g of N,N-dibenzylaniline;

[0056] S2: Pure acrylic emulsion, crosslinking agent, rust converter, defoamer BYK-066N, leveling agent BYK-358N, film-forming aid dodecyl alcohol ester, nano silica, deionized water, and N,N-dibenzylaniline are added to a reaction vessel, stirred, heated to 60°C, stirred at 800 r / min for 40 min, cooled to room temperature, and filtered through a 350 mesh filter to obtain an acrylic rust converter.

[0057] Example 6 Preparation of acrylic rust converter:

[0058] S1: Weigh out: 550g of pure acrylic emulsion, 50g of crosslinking agent (prepared in Example 2), 110g of rust-reducing agent (prepared in Example 4), 10g of defoamer BYK-066N, 11g of leveling agent BYK-333, 25g of film-forming aid dodecyl alcohol ester, 90g of nano silica, 240g of deionized water, and 2g of N,N-dibenzylaniline;

[0059] S2: Add pure acrylic emulsion, crosslinking agent, rust converter, defoamer BYK-066N, leveling agent BYK-333, film-forming aid dodecyl alcohol ester, nano silica, deionized water, and N,N-dibenzylaniline to a reaction vessel, stir, heat to 65℃, stir at 800r / min for 35min, cool to room temperature, and filter using a 350-mesh filter to obtain an acrylic rust converter.

[0060] Example 7 Preparation of acrylic rust converter:

[0061] S1: Weigh out: 600g of pure acrylic emulsion, 60g of crosslinking agent (prepared in Example 3), 120g of rust-reducing agent (prepared in Example 4), 12g of defoamer DF-680, 12g of leveling agent BYK-333, 30g of film-forming aid dodecyl alcohol ester, 100g of nano silica, 250g of deionized water, and 3g of N,N-dibenzylaniline;

[0062] S2: Add pure acrylic emulsion, crosslinking agent, rust converter, defoamer DF-680, leveling agent BYK-333, film-forming aid dodecyl alcohol ester, nano silica, deionized water, and N,N-dibenzylaniline to a reaction vessel, stir, heat to 70℃, stir at 800r / min for 30min, cool to room temperature, and filter using a 350-mesh filter to obtain an acrylic rust converter.

[0063] Comparative Example 1

[0064] The raw material ratio and preparation method of the acrylic rust converter are basically the same as those in Example 6. The difference is that the crosslinking agent added to the component (prepared in Example 2) is replaced with an equal weight of intermediate 2 (prepared in step S2 of Example 2).

[0065] Comparative Example 2

[0066] The raw material ratio and preparation method of the acrylic rust converter are basically the same as in Example 6, except that the crosslinking agent added to the components (prepared in Example 2) is replaced with an equal weight of the crosslinking agent prepared by the following method:

[0067] The preparation method of the crosslinking agent is basically the same as that in Example 2, except that 10-bromo-1-decene in step S2 is replaced with an equal mass of 3-bromopropene.

[0068] Comparative Example 3

[0069] The raw material ratio and preparation method of the acrylic rust converter are basically the same as in Example 6, except that the crosslinking agent added to the components (prepared in Example 2) is replaced with an equal weight of the crosslinking agent prepared by the following method:

[0070] S1: Add 600 ml of tetrahydrofuran, 45.8 g of amino-terminated silicone oil, 20 g of 10-bromo-1-decene, and 12 g of potassium carbonate to a reaction vessel, stir and mix well, heat to reflux, react for 18 h, cool to room temperature, wash three times with saturated brine (200 ml each time), dry with 20 g of anhydrous magnesium sulfate, filter, and distill under reduced pressure at 50 °C for 2 h to obtain the intermediate;

[0071] S2: Add 500ml DMF, 60g intermediate and 3g strong acid cation exchange resin to the reactor, stir and mix well, heat to 55℃, add 5g formic acid and 18g 30wt% hydrogen peroxide solution dropwise, the addition is completed in 20min, react for 8h, cool to room temperature, filter, pour the filtrate into 800ml deionized water and stir to precipitate solid, filter, wash three times with deionized water (200ml each time), dry under vacuum at 60℃ for 24h to obtain crosslinking agent.

[0072] Comparative Example 4

[0073] The raw material ratio and preparation method of the acrylic rust converter are basically the same as those in Example 6. The difference is that the rust converter (prepared in Example 4) added to the components is replaced with an equal weight of intermediate C (prepared in step N3 of Example 4).

[0074] Comparative Example 5

[0075] The raw material ratio and preparation method of the acrylic rust converter are basically the same as in Example 6, except that the rust converter added to the components (prepared in Example 4) is replaced with an equal weight of the rust converter prepared by the following method:

[0076] The preparation method of the rust-reducing agent is basically the same as that in Example 4, except that the amount of epichlorohydrin added in step N4 is replaced with 0.22 mol.

[0077] Comparative Example 6

[0078] The raw material ratio and preparation method of the acrylic rust converter are basically the same as in Example 6, except that the rust converter added to the components (prepared in Example 4) is replaced with an equal weight of the rust converter prepared by the following method:

[0079] The preparation method of the rust-converting agent is basically the same as that in Example 4, except that 2-aminopyridine in step N1 is replaced with an equimolar amount of 4-aminopyridine.

[0080] The pure acrylic emulsion used in this application is S-05 pure acrylic emulsion with a solid content of 48wt%, produced by Jiangsu Shengda New Material Technology Co., Ltd.; the nano silica is model DK-SiO2-30, produced by Suzhou Meierbang Nanomaterials Co., Ltd., with an average particle size of 30nm; the amino-terminated silicone oil is model Cheersil 8110 with an amino content of 2mmol / g, produced by Suzhou Qitian New Material Co., Ltd.; the strong acid cation exchange resin is a polymer of divinylbenzene and sodium vinylbenzene sulfonate, brand name Amberlite® IMAC HP1110 resin.

[0081] Preparation of rusted steel sheet: Q235 steel was cut into pieces of 100mm×150mm×1mm as the metal substrate. The substrate was then ultrasonically cleaned (50Hz) for 20 minutes with 300ml of anhydrous ethanol and 300ml of acetone, and vacuum dried at 80℃ for 2 hours. The cleaned metal substrate was then placed in a salt spray test chamber for a neutral salt spray test, which was conducted in accordance with GB / T10125-2012. In the test chamber, a 5wt% NaCl solution was sprayed, and the test chamber temperature was set to 35℃. After 48 hours, the rusted iron sheet was removed and placed in a vacuum drying oven at 80℃ for 2 hours to obtain the rusted steel sheet.

[0082] Sample preparation: The acrylic rust converters prepared in Examples 5-7 and Comparative Examples 1-6 were sprayed onto rust-affected steel plates using a W-71-G spray gun (spraying pressure 0.3 MPa, spraying distance 200 mm, spraying 3 times) to prepare a smooth and uniform paint film. The films were dried at 25°C for 7 days to obtain the samples. The samples were subjected to adhesion and salt spray resistance tests, and the test results are shown in Table 1.

[0083] Adhesion test: The test is conducted in accordance with the standard GB / T 9286-1998. A cross-cutting tool is used to cut 100 1mm×1mm squares on the ink film layer of the sample. Then, transparent pressure-sensitive adhesive tape is used to firmly adhere the sample and then quickly peel it off to test the adhesion level.

[0084] Salt spray resistance test: The test was conducted in accordance with the standard GB / T 1771-2007. The sample was placed in the test chamber and sprayed with a 5wt% NaCl solution. The test chamber temperature was set to 35℃, and the time it took for the sample to bubble was recorded.

[0085] Table 1 Performance Test Data

[0086]

[0087] As can be seen from Examples 5, 6 and 7 in Table 1, the acrylic rust converter prepared by the present invention has good adhesion and salt spray resistance.

[0088] The crosslinking agent prepared in this invention contains fluorocarbon chains, siloxane segments, and epoxy groups. The epoxy groups can undergo a ring-opening reaction with the carboxyl groups (-COOH) of pure acrylic emulsion to form stable covalent bonds, effectively improving the adhesion of the acrylic rust converter. The fluorocarbon chains have extremely low surface energy, imparting excellent hydrophobic and oleophobic properties to the coating surface, effectively slowing the penetration rate of corrosive media to the metal substrate / rust layer interface and improving salt spray resistance. The siloxane segments reduce the surface tension of the acrylic rust converter system, improving its wettability and spreading ability on complex rusted surfaces, helping it to more tightly encapsulate rust products and penetrate into the micropores of the rust layer, enhancing physical anchoring and further improving adhesion. In contrast, the crosslinking agent used in Comparative Example 2 has a shorter chain length connecting the epoxy groups and siloxanes, affecting the crosslinking effect and leading to decreased adhesion.

[0089] The epoxy groups in the rust-converting agent prepared by this invention can undergo a ring-opening reaction with the carboxyl groups (-COOH) in pure acrylic emulsion to form stable covalent bonds, effectively improving the adhesion of the acrylic rust-converting agent; the two adjacent phenolic hydroxyl groups in the rust-converting agent can react with the Fe in the rust. 3+ Forming stable chelates that coat the surface of the metal substrate, enhancing the passivation effect; the pyridine nitrogen atoms in the rust-removing agent can donate lone pairs of electrons to react with the Fe in the rust. 3+By forming stable coordinate bonds, the amide bond adjacent to the pyridine nitrogen atom can form a hydrogen bond network with the hydroxyl oxygen in the rust, further enhancing its interfacial bonding strength and improving its salt spray resistance. Comparative Example 5 used a rust-transfer agent with more epoxy groups and less phenolic hydroxyl groups, reducing its ability to form chelates and thus decreasing its salt spray resistance.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. An acrylic rust converter, characterized in that, The ingredients include the following parts by weight: 50-60 parts pure acrylic emulsion, 4-6 parts crosslinking agent, 10-12 parts rust-reducing agent, 0.8-1.2 parts defoamer, 1-1.2 parts leveling agent, 2-3 parts film-forming aid, 8-10 parts nano silica, 20-25 parts deionized water, and 0.1-0.3 parts N,N-dibenzylaniline; The crosslinking agent is prepared by the following method: S1: Amino-terminated silicone oil reacts with perfluorooctane to form intermediate 1. S2: Intermediate 1 reacts with 10-bromo-1-decene to generate intermediate 2. S3: Intermediate 2 generates a crosslinking agent under the action of formic acid and hydrogen peroxide; The crosslinking agent has the following structural formula: ； The rust-removing agent is prepared by the following method: N1: 2-Aminopyridine reacts with oleic acid chloride to generate intermediate A. N2: Intermediate A reacts with formic acid and hydrogen peroxide to form intermediate B. N3: Intermediate B reacts with gallic acid to form intermediate C. N4: Intermediate C reacts with epichlorohydrin to generate a rust-reducing agent; The structural formula of the rust-removing agent is as follows: 。 2. The acrylic rust converter according to claim 1, characterized in that, In step S1, the mass ratio of the terminal amino silicone oil to perfluorobromooctane is 1:(1-1.1).

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

1.

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

1.

5. An acrylic rust converter according to claim 1, characterized in that, In step N1, the molar ratio of 2-aminopyridine to oleic acid chloride is 1:1.

1.

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

4.

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

1.

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

05.

9. An acrylic rust converter according to claim 1, characterized in that, The defoamer is one of BYK-066N and DF-680.

10. An acrylic rust converter according to claim 1, characterized in that, The leveling agent is one of BYK-358N and BYK-333.

11. An acrylic rust converter according to claim 1, characterized in that, The film-forming aid is a dodecyl alcohol ester.

12. A method for preparing an acrylic rust converter according to any one of claims 1-11, characterized in that, Includes the following steps: S1: Weigh the following by weight: 50-60 parts pure acrylic emulsion, 4-6 parts crosslinking agent, 10-12 parts rust-reducing agent, 0.8-1.2 parts defoamer, 1-1.2 parts leveling agent, 2-3 parts film-forming aid, 8-10 parts nano silica, 20-25 parts deionized water, and 0.1-0.3 parts N,N-dibenzylaniline; S2: Pure acrylic emulsion, crosslinking agent, rust converter, defoamer, leveling agent, film-forming aid, nano silica, deionized water, and N,N-dibenzylaniline are heated and stirred until homogeneous, cooled to room temperature, and filtered through a filter screen to obtain an acrylic rust converter.

Images