Surface treatment mode of corrosion-resistant high-strength steel bar and concrete of corrosion-resistant high-strength steel bar

Abstract

The invention discloses a surface treatment mode of a corrosion-resistant high-strength steel bar and concrete thereof, and the surface treatment mode of the corrosion-resistant high-strength steel bar comprises the following steps: uniformly stirring and dispersing a four-arm fluorine-containing epoxy silane modified epoxy resin anticorrosive coating for later use; the surface of the steel bar is derusted to Sa2.5 level through acid pickling or sand blasting, oil stains, dust and other impurities on the surface of the steel bar are removed, the temperature is increased to 40-50 DEG C, the surface of the steel bar is coated with the standby four-arm fluorine-containing epoxy silane modified epoxy resin anticorrosive paint, standing, drying and curing are conducted, and surface treatment of the corrosion-resistant high-strength steel bar is completed. Through molecular design, the anticorrosive paint obtains a super-hydrophobic barrier, interface strengthening and self-repairing are cooperated, and the chemical corrosion resistance is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel bar anti-corrosion coatings, and in particular relates to a surface treatment method for corrosion-resistant high-strength steel bars and concrete thereof. Background Art

[0002] Steel bar corrosion is the main reason for the reduced service life of concrete structures. Years of engineering practice have shown that the use of coated steel bars is one of the effective ways to improve the durability of concrete structures, among which epoxy resin coating is the most commonly used in concrete structures.

[0003] Epoxy resin coated steel bars have been widely used in the field of anti-corrosion coatings due to their superior corrosion resistance. However, due to certain usage defects, their further application and development are limited. The current problems with epoxy resin coated steel bars are: compatibility between the coating and concrete: the surface of the epoxy resin coating is smooth. When it is used as an anti-corrosion material for concrete steel bars, the bond strength between the surface of the coated steel bars and the concrete is reduced. Therefore, in order to ensure the safety and service life of the coated steel bar concrete structure, the anchorage length of the coated steel bar must be increased, generally 1.25 times the anchorage length of ordinary steel bars. At the same time, due to the low porosity of high-strength concrete, ordinary epoxy resins are difficult to form deep anchorages; local damage to the coating leads to corrosion spread: construction collisions or concrete shrinkage can easily cause microcracks in the coating, and chloride ions penetrate along the damaged areas, causing pitting corrosion of the steel bars.

[0004] Ordinary epoxy resin relies on physical barriers to block chloride ions, which has limitations; its adhesion depends on physical anchoring, and it is easy to fall off due to surface defects or corrosion of the steel bar; it has no self-repairing ability, and corrosion spreads rapidly after damage; its cross-linking density is not high, and it is easily corroded by hydroxide ions and sulfate ions. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a surface treatment method for corrosion-resistant high-strength steel bars and concrete thereof.

[0006] The technical solutions for achieving the purpose of the present invention are as follows:

[0007] A surface treatment method for corrosion-resistant high-strength steel bars comprises the following steps: uniformly stirring and dispersing a four-arm fluorinated epoxy silane modified epoxy resin anticorrosive coating and setting it aside; removing rust from the steel bar surface by pickling or sandblasting to Sa2.5 level to remove oil, dust and other impurities on the steel bar surface; heating the steel bar surface to 40-50° C.; applying the four-arm fluorinated epoxy silane modified epoxy resin anticorrosive coating to the steel bar surface; allowing the coating to stand and dry and solidify, thereby completing the surface treatment of the corrosion-resistant high-strength steel bar; the heating is performed under inert gas protection; and the coating is performed by one or more of brushing, dipping, rolling and spraying.

[0008] A corrosion-resistant high-strength steel bar comprises a steel bar and an anti-corrosion coating applied to the outer surface of the steel bar; the steel bar is threaded steel or round steel; the four-arm fluorinated epoxy silane-modified epoxy resin anti-corrosion coating comprises component I and component II; component I comprises, by weight, 30-50% modified composite epoxy resin, 10-15% pigment, 5-11% solvent, 0.5-1.5% anti-settling agent, 0.5-1.5% dispersant, 0.2-1.0% defoaming agent, and 15-20% filler; component II is a curing agent, added in an amount of 6-15% of the mass of the modified composite epoxy resin.

[0009] The modified composite epoxy resin is composed of bisphenol A epoxy resin and modified epoxy resin in a molar ratio of (1-5):1;

[0010] The solvent is selected from one or more of toluene, xylene, n-butanol, isobutanol, acetone, methyl isobutyl ketone, and butanone;

[0011] The pigment is one or more of titanium dioxide, zinc oxide, barium sulfate, and lithopone;

[0012] The filler is selected from one or more of heavy calcium, light calcium, and talc;

[0013] The curing agent is selected from one or more of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and diethylaminopropylamine;

[0014] The anti-settling agent is selected from one or more of Aerosil 200, Disparlon 6900-20X, and Crayvallac Ultra;

[0015] The dispersant is selected from one or more of TEGO Dispers 710, BYK-110, BYK-2150, and Disponer 983;

[0016] The defoaming agent is selected from one or more of BYK-052N, BYK-085, and TEGO Foamex 800;

[0017] The modified epoxy resin is copolymerized by monomer A, monomer B and monomer C; the monomer A is a four-arm fluorine-containing epoxy silane compound, the monomer B is a dicarboxylic acid compound, and the monomer C is a dihydroxy mixture; the molar ratio of monomer A, monomer B and monomer C is 1:(1-2):(1-2); it should be noted that when monomer A, monomer B and monomer C are completely reacted, the theoretical molar ratio is 1:4:2, that is, one molecule of monomer A first reacts with four molecules of monomer B to form an AB intermediate, and then monomer C reacts with the free carboxyl groups of two molecules of the AB intermediate to generate an ABCBA structure. The present invention selects a molar ratio of monomer A, monomer B and monomer C of 1:(1-2):(1-2) in order to expose the epoxy group, which is cross-linked with the epoxy group of the bisphenol A epoxy resin through a curing agent to obtain better anti-corrosion and mechanical properties;

[0018] The preparation method of the modified composite epoxy resin comprises the following steps: mixing bisphenol A epoxy resin and modified epoxy resin by ball milling at a molar ratio of (1-5):1, then melt-extruding with a twin-screw extruder at a rotation speed of 100-120 r / min, a temperature of 90° C. in the first zone, and a temperature of 100° C. in the second zone; tableting, crushing, and passing through a 200-mesh sieve to obtain the modified composite epoxy resin;

[0019] The preparation method of the four-arm fluorinated epoxy silane modified epoxy resin anticorrosive coating comprises the following steps:

[0020] (1) Mix the solvent and the modified composite epoxy resin and stir at 300-500 rpm until uniform;

[0021] (2) Add pigment, filler, anti-settling agent, dispersant, and defoamer, and disperse at 1200-1500 rpm for 15-25 minutes;

[0022] (3) The above mixture is mixed with a curing agent to obtain a four-arm fluorinated epoxy silane modified epoxy resin anti-corrosion coating.

[0023] The preparation method of the modified epoxy resin comprises the following steps:

[0024] Under a nitrogen atmosphere, monomer A, monomer B, and monomer C are weighed in a molar ratio of 1:(1-2):(1-2); monomer A and monomer B and N,N-dimethylformamide are mixed, 0.5-1.0% by mass of p-toluenesulfonic acid is added, and the mixture is stirred and heated to 70-80° C. at a stirring speed of 800 r / min for 2-3 hours; the mixture is cooled to 50° C., 0.2-0.3% by mass of sodium bicarbonate is added to neutralize the residual acid catalyst, the mixture is stirred for 30 minutes, the precipitate is removed by filtration, and the solvent is removed by reduced pressure distillation; toluene is used as the solvent, monomer C is added to the mixture, the mixture is stirred and heated to 110-120° C., 0.1-0.2% by mass of tetrabutyl titanate is added, and the mixture is reacted for 3-4 hours; the solvent is removed by reduced pressure distillation to obtain a four-arm fluorinated epoxy silane modified epoxy resin.

[0025] The preparation method of the monomer A1 comprises the following steps:

[0026] (1) Synthesis of bis(dichlorosilane): Under nitrogen atmosphere, 1 eq of divinyldimethylsilane and 3 eq of methyldichlorosilane were dissolved in anhydrous toluene, and then 0.0025 eq of tetrakis(triphenylphosphine)platinum was added. The mixture was stirred and heated to 70°C and allowed to react overnight. The solvent and excess dimethylchlorosilane were removed by evaporation under reduced pressure to obtain a bis(dichlorosilane) intermediate, the structure of which is shown in Formula 3:

[0027]

[0028] (2) Under nitrogen atmosphere, 1 eq of acid binding agent and 1 eq of bis(dichlorosilane) were mixed and stirred in toluene, heated to 50°C and stirred, 4.5 eq of 2,2-bis(4-aminophenyl)hexafluoropropane was added, and then stirred at 50°C for 1 hour, and then heated to 65°C and stirred for 3 hours. After the reaction, the mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the aminosilane intermediate was obtained by silica gel column chromatography. The structure is shown in Formula 4:

[0029]

[0030] (3) Under nitrogen atmosphere, 1 eq of aminosilane intermediate was mixed with acetonitrile and stirred at room temperature. Then, 5.5-6.5 eq of epichlorohydrin was added, and then 4.5-5.5 eq of pyridine was slowly added. The mixture was stirred at room temperature for 2 h. After the reaction was completed, the solvent was removed under reduced pressure. The mixture was washed and extracted with ethyl acetate and 1 mol / L sodium hydroxide solution. The organic phases were combined and anhydrous sodium sulfate was added to remove water to obtain monomer A, the structure of which is shown in Formula 1:

[0031]

[0032] The preparation method of the monomer B comprises the following steps: under a nitrogen atmosphere, adding 1eq2,2-bis[4-(4-aminophenoxy)phenyl]propane and 2eq trimellitic anhydride to N,N-dimethylformamide, stirring and heating to 30°C for reaction for 2 hours, then heating to 70°C for reaction for 2 hours, adding toluene, and refluxing and stirring at 110-120°C for 6 hours; pouring the mixture into ice water, washing the precipitate three times with deionized water, and drying at 120°C for 6 hours to obtain the product monomer B, the structure of which is shown in Formula 2:

[0033]

[0034] The monomer C is prepared by mixing fluorine chain E10H and polyethylene glycol in a molar ratio of 1:(10-15);

[0035] Another object of the present invention is to provide a corrosion-resistant high-strength reinforced concrete, comprising a steel cage formed by binding the steel bars and concrete poured in the steel cage and the formwork; the concrete, in terms of mix ratio, comprises the following components: fly ash 50-100 kg / m 3 , silica fume 50~100kg / m 3 , slag powder 50~100kg / m 3 , cement 250~400kg / m 3 , sand 700~850kg / m 3 , crushed stone 850~950kg / m 3 , water 150~200kg / m 3 , water reducing agent 3~10kg / m 3 .

[0036] Beneficial effects

[0037] The present invention has the following beneficial effects:

[0038] The present invention achieves the following effects by molecular design and chemical modification of epoxy resin monomers:

[0039] 1. Establish a super-hydrophobic barrier: By introducing trifluoromethyl into the four-arm fluorinated epoxysilane monomer and using the fluorine chain E10H, a hydrophobic barrier is formed on the surface of the coating, reducing the chloride ion diffusion coefficient;

[0040] 2. Interface strengthening and self-repair synergy: amino groups and Fe on the steel bar surface 3+ Forming Fe-N coordination bonds, the adhesion is improved compared to ordinary epoxy coatings; when the coating is damaged, the exposed secondary amino groups absorb OH in the corrosive medium through electrostatic action -, forming a local passivation film to inhibit the spread of rust; at the same time, through molecular design, four symmetrically distributed amino arms form multiple adsorption sites, greatly covering the surface defects of the steel bars and achieving uniform passivation; and the phthalic acid imide bond on monomer B slowly hydrolyzes into free carboxyl groups and residual amide structures under the strong alkaline conditions of concrete. The carboxyl groups have an electrostatic repulsion to chloride ions, which physically and chemically blocks chloride ion corrosion while improving interfacial adhesion; the rigid benzene ring and long Si-C chain rigid-flexible balance design help improve impact resistance;

[0041] 3. Improved chemical corrosion resistance: Dicarboxylic acid monomers and arm-fluorinated epoxy silane monomers form a high cross-linking density network, effectively reducing porosity and blocking the diffusion path of corrosive media; coupled with trifluoromethyl, it can effectively resist OH in the concrete pore fluid. - and SO4 2- Corrosion, so that the steel coating can remain stable in the concrete environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the synthetic route of monomer A;

[0043] Figure 2 This is the synthetic route of monomer B;

[0044] Figure 3 is the H NMR spectrum of monomer A1;

[0045] Figure 4 is the H NMR spectrum of monomer B1;

[0046] Figure 5 This is the infrared spectrum of modified epoxy resin 1. DETAILED DESCRIPTION

[0047] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0048] In the examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0049] The raw materials and equipment used in the embodiments and comparative examples are described below:

[0050] Monomer A1: Homemade, preparation method is as follows:

[0051] S1. Synthesis of bis(dichlorosilane): Under a nitrogen atmosphere, 1 eq of divinyldimethylsilane and 3 eq of methyldichlorosilane were dissolved in anhydrous toluene. 0.0025 eq of tetrakis(triphenylphosphine)platinum was then added, stirred, heated to 70°C, and reacted overnight. The solvent and excess dimethylchlorosilane were removed by evaporation under reduced pressure to obtain a bis(dichlorosilane) intermediate having the structure shown in Formula 3:

[0052]

[0053] S2. Under a nitrogen atmosphere, 1 eq of an acid-binding agent and 1 eq of bis(dichlorosilane) were mixed in toluene and stirred. The mixture was heated to 50°C and stirred. 4.5 eq of 2,2-bis(4-aminophenyl)hexafluoropropane was added, and the mixture was stirred at 50°C for 1 hour. The mixture was then heated to 65°C and stirred for 3 hours. After the reaction, the mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the mixture was purified by silica gel column chromatography to obtain an aminosilane intermediate having the structure shown in Formula 4:

[0054]

[0055] S3. Under a nitrogen atmosphere, 1 eq of the aminosilane intermediate was mixed with acetonitrile and stirred at room temperature. 5.5 eq of epichlorohydrin was then added, followed by the slow addition of 5 eq of pyridine. The mixture was stirred at room temperature for 2 h. After the reaction, the solvent was removed under reduced pressure, and the mixture was washed and extracted with ethyl acetate and 1 mol / L sodium hydroxide solution. The organic phases were combined and dehydrated with anhydrous sodium sulfate to obtain a four-arm fluorinated epoxysilane monomer having the structure shown in Formula 1:

[0056]

[0057] Monomer A2: homemade. The preparation method is similar to that of monomer A1, except that the 2,2-bis(4-aminophenyl)hexafluoropropane added in step S2 is replaced with 2,2-bis(4-aminophenyl)propane. Other conditions remain unchanged, yielding monomer A2, the structure of which is shown in Formula 5:

[0058]

[0059] Monomer A3: bisphenol A epoxy resin, product number 31185, purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0060] Monomer B1: Homemade, preparation method is as follows:

[0061] Under a nitrogen atmosphere, 1 eq of 2,2-bis[4-(4-aminophenoxy)phenyl]propane and 2 eq of trimellitic anhydride were added to N,N-dimethylformamide, stirred and heated to 30°C for 2 h, then heated to 70°C for 2 h, toluene was added, and the mixture was refluxed and stirred at 115°C for 6 h. The mixture was poured into ice water, and the precipitate was washed three times with deionized water and dried at 120°C for 6 h to obtain the product monomer B1, whose structure is shown in Formula 2:

[0062]

[0063] Monomer B2: terephthalic acid, product number P108506, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0064] Monomer C1: homemade, prepared as follows: fluorinated chain E10H and polyethylene glycol were mixed in a molar ratio of 1:10;

[0065] Monomer C2: homemade. Compared with the preparation method of monomer C1, the difference is that the fluorine chain E10H and polyethylene glycol are mixed in a molar ratio of 1:15;

[0066] Monomer C3: polyethylene glycol: molecular weight 2000 g / mol, product number V32184, purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0067] Divinyldimethylsilane: product number 1238772, purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.

[0068] Methyldichlorosilane: Product No. D807454, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0069] Tetrakis(triphenylphosphine) platinum: product number 1156208, purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.;

[0070] Acid binding agent: 1,8-diazabicyclo[5.4.0]undec-7-ene, product number D106478, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0071] 2,2-Bis[4-(4-aminophenoxy)phenyl]propane: product number 1019482, purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.;

[0072] Trimellitic anhydride: product number 1035647, purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.

[0073] 2,2-Bis(4-aminophenyl)hexafluoropropane: product number 1238656, purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.

[0074] Epichlorohydrin: Product No. E401255, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0075] Fluorochain E10H: molecular weight 1800 g / mol, purchased from Acota (UK);

[0076] Pigment: titanium dioxide, product number DA043921, purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.

[0077] Filler: Talc powder, product number T761744, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.;

[0078] Hexamethylenediamine: purchased from Shandong Jinyueyuan New Materials Co., Ltd.

[0079] Defoaming agent: BYK-052N, purchased from Guangzhou Si Tu Yuan Chemical Co., Ltd.

[0080] Anti-settling agent: Aerosil 200, purchased from Tokyo Chemical Industry Development Co., Ltd. (Shanghai);

[0081] Dispersant: TEGO Dispers 710, purchased from Hubei Zhonglong Kangsheng Fine Chemical Co., Ltd.;

[0082] Unless otherwise specified, the components and raw materials used in the examples and comparative examples of the present invention are all commercially available raw materials, and the components and raw materials used in each parallel experiment are all of the same kind.

[0083] Preparation Example 1

[0084] Modified epoxy resin 1: Homemade, preparation method is as follows:

[0085] Under a nitrogen atmosphere, monomer A1, monomer B1, and monomer C1 were weighed in a molar ratio of 1:1.5:1.5; monomer A1 and monomer B1 were mixed with N,N-dimethylformamide, and 0.5% by mass of p-toluenesulfonic acid was added. The mixture was stirred and heated to 75°C at a stirring speed of 800 r / min for 3 h. The temperature was lowered to 50°C, and 0.2% by mass of sodium bicarbonate was added to neutralize the residual acid catalyst. The mixture was stirred for 30 min, the precipitate was removed by filtration, and the solvent was removed by distillation under reduced pressure. Toluene was used as the solvent, and monomer C1 was added to the mixture. The mixture was stirred and heated to 110°C, and 0.1% by mass of tetrabutyl titanate was added and reacted for 4 h. The solvent was removed under reduced pressure, and 0.1% by mass of sodium bicarbonate was added to neutralize the residual acid catalyst to obtain a modified epoxy resin 1.

[0086] Preparation Example 2

[0087] Modified epoxy resin 2: homemade. Compared with the preparation method of modified epoxy resin 1, the difference is that the molar ratio of monomer A1, monomer B1, and monomer C1 is replaced by 1:1:1 instead of 1:1.5:1.5. Other conditions remain unchanged to obtain modified epoxy resin 2.

[0088] Preparation Example 3

[0089] Modified epoxy resin 3: homemade. Compared with the preparation method of modified epoxy resin 1, the difference is that the molar ratio of monomer A1, monomer B1, and monomer C1 is replaced by 1:1.5:1.5 to 1:2:2. Other conditions remain unchanged to obtain modified epoxy resin 3.

[0090] Preparation Example 4

[0091] Modified epoxy resin 4: homemade. Compared with the preparation method of modified epoxy resin 1, the difference is that monomer A1 is replaced by monomer A2.

[0092] Preparation Example 5

[0093] Modified epoxy resin 5: homemade. Compared with the preparation method of modified epoxy resin 1, the difference is that monomer A1 is replaced by monomer A3;

[0094] Preparation Example 6

[0095] Modified epoxy resin 6: homemade. Compared with the preparation method of modified epoxy resin 1, the difference is that monomer B1 is replaced by monomer B2.

[0096] Preparation Example 7

[0097] Modified epoxy resin 7: homemade. Compared with the preparation method of modified epoxy resin 1, the difference is that monomer C1 is replaced by monomer C2;

[0098] Preparation Example 8

[0099] Modified epoxy resin 8: homemade. Compared with the preparation method of modified epoxy resin 1, the difference is that monomer C1 is replaced by monomer C3;

[0100] Preparation Example 9

[0101] Modified epoxy resin 9: homemade. Compared with the preparation method of modified epoxy resin 1, the difference is that monomer A1 is replaced by A3, B1 is replaced by B2, and C1 is replaced by monomer C3;

[0102] Table 1 Formula of Preparation Examples 1 to 9 (mol)

[0103]

[0104] Example

[0105] Example 1

[0106] Modified anti-corrosion coating 1 and its application, the operation steps are as follows:

[0107] (1) 37.5 kg of bisphenol A epoxy resin and 12.5 kg of Preparation Example 1 were ball-milled and then melt-extruded using a twin-screw extruder at a speed of 110 r / min, a temperature of 90° C. in the first zone, and a temperature of 100° C. in the second zone; tableted, crushed, and passed through a 200-mesh sieve to obtain a modified composite epoxy resin;

[0108] (2) Mix 11 kg of toluene with the modified composite epoxy resin and stir at 300-500 rpm until uniform;

[0109] (3) Add 15 kg pigment, 20 kg filler, 1.5 kg anti-settling agent, 1.5 kg dispersant, and 1 kg defoamer, and disperse at 1200-1500 rpm for 15-25 minutes;

[0110] (4) mixing the above mixture with 6.9 kg of hexamethylenediamine to obtain a modified anti-corrosion coating 1;

[0111] (5) Application: Stir and disperse the modified anti-corrosion coating 1 evenly and set aside; pickle or sandblast the surface of a steel bar with a diameter of 12 mm to Sa2.5 level to remove oil, dust and other impurities on the surface of the steel bar; heat it to 50°C under nitrogen protection; apply the modified anti-corrosion coating 1 to the steel bar surface by spraying, control the coating thickness to 220 μm, let it stand at room temperature, dry and solidify for 7 days, and complete the application of the modified anti-corrosion coating 1.

[0112] Example 2

[0113] Modified anti-corrosion coating 2 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that the addition amount of bisphenol A epoxy resin is replaced by 25 kg, the addition amount of Preparation Example 1 is replaced by 25 kg, and the addition amount of hexamethylenediamine is replaced by 6.2 kg.

[0114] Example 3

[0115] Modified anti-corrosion coating 3 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that the addition amount of bisphenol A epoxy resin is replaced by 8.4 kg, the addition amount of Preparation Example 1 is replaced by 41.6 kg, and the addition amount of hexamethylenediamine is replaced by 5.2 kg.

[0116] Example 4

[0117] Modified anti-corrosion coating 4 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that Preparation Example 1 is replaced by Preparation Example 2, and the amount of hexamethylenediamine added is replaced by 7.1 kg.

[0118] Example 5

[0119] Modified anti-corrosion coating 5 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that Preparation Example 1 is replaced by Preparation Example 3, and the amount of hexamethylenediamine added is replaced by 6.7 kg.

[0120] Example 6

[0121] Modified anti-corrosion coating 6 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that Preparation Example 1 is replaced by Preparation Example 4.

[0122] Example 7

[0123] Modified anti-corrosion coating 7 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that Preparation Example 1 is replaced by Preparation Example 5, and the amount of hexamethylenediamine added is replaced by 6.2 kg.

[0124] Example 8

[0125] Modified anti-corrosion coating 8 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that Preparation Example 1 is replaced by Preparation Example 6.

[0126] Example 9

[0127] Modified anti-corrosion coating 9 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that Preparation Example 1 is replaced by Preparation Example 7.

[0128] Example 10

[0129] Modified anti-corrosion coating 10 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that Preparation Example 1 is replaced by Preparation Example 8.

[0130] Comparative Example

[0131] Anti-corrosion coating 11 and its application: The operation steps are compared with the modified anti-corrosion coating 1 and its application, except that Preparation Example 1 is replaced by Preparation Example 9, and the amount of hexamethylenediamine added is replaced by 6.2 kg.

[0132] Table 2 Formula of Examples 1 to 10 and Comparative Examples (kg)

[0133]

[0134]

[0135] The following are the test methods for the performance parameters involved in the present invention:

[0136] 1. H NMR spectrum: 400 MHz NMR spectrometer, Bruker, Germany;

[0137] 2. Fourier transform infrared spectroscopy (FTIR) measurement: Spectrum two, PerkinElmer, USA;

[0138] 3. Appearance test: Prepare test samples according to GB / T 9761-2008 “Visual color comparison of paints and varnishes” and conduct appearance test of the paint film;

[0139] 4. Hot water resistance: Prepare the test panel according to GB / T 1733-1993 "Determination of water resistance of paint films" and use the boiling water immersion test method;

[0140] 5. Salt spray resistance test: Prepare test specimens according to GB / T 1771-1991 "Paints and varnishes - Determination of resistance to neutral salt spray" and test the salt spray resistance of the coating using a Q-FOG salt spray corrosion test chamber.

[0141] 6. Impact resistance test: Prepare the substrate and apply the test panels in accordance with GB / T 1732-2020 "Determination of impact resistance of paint films". Steel panels are used as the substrate for testing. The results are expressed as the maximum height at which cracks, wrinkles, and peeling are observed in three tests.

[0142] 7. Adhesion test: Refer to GB / T 9286-2021 "Paint and varnish cross-cut test" to test the adhesion of the paint film.

[0143] The specific test results are shown in Table 3.

[0144] Table 3 Performance test results of Examples 1 to 10 and Comparative Examples

[0145]

[0146]

[0147] The data in Table 3 indicate that the trifluoromethyl group in monomer A1 facilitates the formation of a dense physical barrier, preventing salt spray corrosion and maintaining coating integrity in salt spray environments. The rigid trifluoromethyl group facilitates the dispersion of impact forces, while the flexible Si-C chain absorbs energy, resulting in a synergistic effect of rigidity and flexibility, and improved impact resistance. The phthalimide structure in monomer B1 facilitates the formation of hydrogen bonds with the epoxy network, forming a dense network with good resistance to hot water. The nitrogen in the phthalimide group can chelate the iron ions in steel, inhibiting anodic reactions, and the carboxyl group has an electrostatic repulsion against chloride ions, providing both physical and chemical barriers to chloride ion corrosion while enhancing interfacial adhesion. Compared with dibenzoic acid, the balanced rigidity and flexibility of monomer B1 contributes to improved impact resistance. Monomer C1 simultaneously balances the fluorine chain and the polyethylene glycol chain, achieving optimal performance, and works best when combined with monomers A1 and B1.

[0148] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A surface treatment method for corrosion-resistant high-strength steel bars, characterized in that: The following steps are involved: The four-arm fluorinated epoxy silane modified epoxy resin anti-corrosion coating is stirred and dispersed evenly and set aside; the steel bar surface is pickled or sandblasted to Sa2.5 level to remove oil, dust and other impurities on the steel bar surface, and the temperature is raised to 40-50°C. The four-arm fluorinated epoxy silane modified epoxy resin anti-corrosion coating is applied to the steel bar surface, and the steel bar is allowed to stand and dry and solidify to complete the surface treatment of the corrosion-resistant high-strength steel bar.

2. The surface treatment method of the corrosion-resistant high-strength steel bar according to claim 1, characterized in that: The heating is carried out under the protection of inert gas; the coating is carried out by one or more of brush coating, dipping coating, rolling coating and spraying.

3. A corrosion-resistant high-strength steel bar, characterized in that: It includes steel bars and anti-corrosion coatings coated on the outer surfaces of the steel bars; the steel bars are threaded steel bars or round steel bars; the anti-corrosion coating is a four-arm fluorinated epoxy silane modified epoxy resin anti-corrosion coating, including component I and component II; the components of component I are as follows by weight percentage: 30-50% modified composite epoxy resin, 10-15% pigment, 5-11% solvent, 0.5-1.5% anti-settling agent, 0.5-1.5% dispersant, 0.2-1.0% defoaming agent, and 15-20% filler; the component II is a curing agent, and the addition amount is 6%-15% of the mass of the modified composite epoxy resin.

4. The corrosion-resistant high-strength steel bar according to claim 3, characterized in that: The modified composite epoxy resin is composed of a bisphenol A epoxy resin and a modified epoxy resin in a molar ratio of (1-5):1; the modified epoxy resin is copolymerized by monomer A, monomer B and monomer C; the monomer A is a four-arm fluorinated epoxy silane compound, the monomer B is a dicarboxylic acid compound, and the monomer C is a dihydroxy mixture; the structure of monomer A is shown in Formula 1, and the structure of monomer B is shown in Formula 2:

5. The corrosion-resistant high-strength steel bar according to claim 4, characterized in that: The molar ratio of monomer A, monomer B and monomer C of the modified epoxy resin is 1:(1-2):(1-2); the dihydroxy monomer is prepared by mixing fluorine chain E10H and polyethylene glycol in a molar ratio of 1:(10-15).

6. The corrosion-resistant high-strength steel bar according to claim 3, characterized in that: The solvent is one or more of toluene, xylene, n-butanol, isobutanol, acetone, methyl isobutyl ketone, and butanone.

7. The corrosion-resistant high-strength steel bar according to claim 3, characterized in that: The pigment is one or more of titanium dioxide, zinc oxide, barium sulfate, and lithopone.

8. The corrosion-resistant high-strength steel bar according to claim 3, characterized in that: The filler is selected from one or more of heavy calcium, light calcium and talc.

9. The corrosion-resistant high-strength steel bar according to claim 3, characterized in that: The curing agent is selected from one or more of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and diethylaminopropylamine.

10. A corrosion-resistant high-strength reinforced concrete, characterized in that: The invention comprises a steel cage formed by tying steel bars according to any one of claims 3 to 9 and concrete poured in the steel cage and the formwork, wherein the concrete comprises the following components in terms of mix ratio: fly ash 50-100 kg / m 3 , silica fume 50~100kg / m 3 , slag powder 50~100kg / m 3 , cement 250~400kg / m 3 , sand 700~850kg / m 3 , crushed stone 850~950kg / m 3 , water 150~200kg / m 3 , water reducing agent 3~10kg / m 3 .

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