Nano titanium-organic silicon modified epoxy resin anticorrosive coating as well as preparation method and application thereof

Abstract

The invention discloses a nano titanium-organic silicon modified epoxy resin anticorrosive coating and a preparation method and application thereof.The preparation method comprises the following steps that organic silicon modified epoxy resin is prepared, nano titanium functional filler is prepared, and then the prepared organic silicon modified epoxy resin, powder filler, a dispersing agent, a flatting agent and a defoaming agent are taken to be evenly mixed; adding into a mixed solvent, putting into a high-speed dispersion machine, and stirring at normal temperature at the rotating speed of 2000-3000rpm to obtain mixed slurry; then, adding a nano titanium functional filler, and stirring in a high-speed dispersion machine at normal temperature at the rotating speed of 2000-3000rpm to obtain a nano titanium-organic silicon modified epoxy resin coating; then adding an amine curing agent into the coating, mixing and stirring, and finally coating the surface of a base material with the coating and drying to obtain a cured coating. The high-temperature-resistant coating which is excellent in comprehensive performance and can provide anti-corrosion protection for high-temperature marine equipment for a long time is prepared.

Description

Technical Field

[0001] The invention relates to the technical field of anti-corrosion coatings, and in particular to a nano-titanium-organic silicon modified epoxy resin anti-corrosion coating and a preparation method and application thereof. Background Art

[0002] High-temperature equipment in ships and marine engineering equipment is not only exposed to high humidity and high salt marine environment during use, but also factors such as long-term high temperature working environment will accelerate corrosion and structural loss, thus causing property loss and safety hazards. Applying high-performance high-temperature resistant anti-corrosion coatings is an effective protective measure to extend the service life of high-temperature marine equipment. It has high temperature tolerance while protecting the surface of the equipment from corrosion. The development of long-lasting high-temperature resistant heavy-duty anti-corrosion coatings for complex and harsh marine environments and long-term high-temperature corrosion is a problem that needs to be solved urgently.

[0003] Epoxy-based coatings are one of the most widely used coatings in the field of marine corrosion protection. The epoxy resin molecular structure contains polar functional groups such as hydroxyl groups and ether bonds, which have good substrate adhesion. At the same time, the benzene ring in the molecular chain provides the coating with good rigidity, hardness and chemical stability. The coating prepared by modifying epoxy resin and combining it with various functional fillers and additives can be used for corrosion protection in different occasions. It also has the characteristics of scalable production and strong construction operability. However, the following problems still exist in the preparation of high-temperature resistant and heavy-duty anti-corrosion coatings based on epoxy resin:

[0004] Problem 1: Epoxy coating has poor high temperature tolerance

[0005] Compared with silicone resin coatings with excellent high temperature resistance, epoxy resin coatings have good mechanical properties and substrate adhesion after curing. However, the cured epoxy resin will undergo high-temperature oxidation at temperatures above 180°C in air atmosphere and has poor high temperature resistance. When the equipment is in a high-temperature corrosive environment for a long time, traditional epoxy coatings are more likely to fail and their service life cannot meet industrial needs.

[0006] Problem 2: Epoxy coatings can produce various defects during the curing process

[0007] Epoxy coating is formed by the rapid cross-linking reaction between epoxy resin and curing agent. The internal stress generated by the rapid cross-linking reaction cannot be effectively released, resulting in tiny cracks inside the coating. At the same time, pores are generated inside the coating due to the large amount of solvent volatilization. Therefore, various corrosive media will penetrate into the substrate through the internal pores of the epoxy coating, and high temperature will further accelerate the breakage of the coating resin molecular chain, eventually leading to the failure of the coating, and unable to provide long-term protection for the metal substrate.

[0008] Problem 3: The preparation cost of nano-functional fillers is high and their dispersion in the coating is poor

[0009] Nanomaterials have a large specific surface area and small size, and generally have more excellent physical and chemical properties than traditional materials. As functional fillers, they can not only improve the conventional properties of coatings, but also endow coatings with other special functions. However, there are still problems in the application of nano-fillers in anti-corrosion coatings. First of all, compared with traditional functional fillers, the preparation of nano-functional fillers is limited by factors such as technical processes, with a small production scale and high cost. Secondly, the surface energy of nanomaterials is relatively high and there are interaction forces, and nano-particles or sheets are prone to agglomeration, with poor dispersibility in silicone-modified epoxy resins, resulting in various defects inside the coating during the curing process and reducing the service life of the anti-corrosion coating. Therefore, reducing the production cost of nano-functional fillers, expanding the production scale, and solving the dispersibility problem in coatings are also difficult problems that need to be overcome urgently in the current research field of anti-corrosion coatings.

[0010] Problem 4: Traditional epoxy coatings are difficult to cope with high-temperature and extreme marine composite corrosion environments simultaneously

[0011] Epoxy coatings can improve high-temperature stability by adding high-temperature resistant functional fillers such as aluminum powder, phosphate, chromium oxide, etc., and can also meet the anti-corrosion requirements in ordinary atmospheric environments. However, for marine engineering equipment serving in extreme marine environments and requiring operation at high temperatures at the same time, the above-mentioned epoxy-based composite coatings obviously cannot meet the long-term protection requirements. Therefore, developing anti-corrosion coatings suitable for extreme marine environments and capable of withstanding high temperatures is still a difficult problem that needs to be overcome urgently. Summary of the Invention

[0012] In view of this, aiming at the problems existing in the prior art, the purpose of the present invention is to provide a nano-titanium-silicone modified epoxy resin anti-corrosion coating, its preparation method and application, effectively solving problems such as poor corrosion resistance and high-temperature tolerance after curing of traditional epoxy anti-corrosion coatings, various defects generated inside during rapid curing, and poor dispersibility of functional fillers in the coating.

[0013] The technical solution adopted is as follows:

[0014] A preparation method of a nano-titanium-silicone modified epoxy resin anti-corrosion coating of the present invention includes the following steps:

[0015] S1. Uniformly mix epoxy resin and xylene solvent, add silicone resin and remove water under vacuum; add silane coupling agent and dibutyltin dilaurate, and raise the temperature to 80-100 °C and stir evenly to obtain silicone-modified epoxy resin;

[0016] S2. Put titanium powder, silicone resin and grinding aid into a high-energy ball mill, and grind the titanium powder, silicone resin and grinding aid at room temperature and a rotation speed of 1000-3000 rpm at high speed to obtain a black paste-like substance, which is the nano-titanium functional filler;

[0017] S3. First, take the silicone-modified epoxy resin, powder filler, dispersant, leveling agent, and defoaming agent prepared in S1, add them to a mixed solvent, place them in a high-speed disperser, and stir at a speed of 2000 - 3000 rpm at room temperature to obtain a mixed slurry; then, add the nano-titanium functional filler, place it in a high-speed disperser, and stir at a speed of 2000 - 3000 rpm at room temperature to obtain a nano-titanium-silicone-modified epoxy resin coating;

[0018] S4. Add an amine curing agent to the coating and mix and stir evenly, and finally coat it on the surface of the substrate and dry to obtain a cured coating.

[0019] Further, in S1, the epoxy resin is one or more of E20, E44, E51, and F44; and / or, in S1 and S2, the silicone resin is one or more of polymethyl silicone resin, polyaryl silicone resin, and methylphenyl silicone resin.

[0020] Further, in S1, the mass ratio of the silicone resin to the epoxy resin is (1 - 2):1; and / or, in S2, the mass ratio of the titanium powder to the silicone resin is 5:(2 - 6).

[0021] Further, in S2, the grinding aid is one or more of xylene, dichloromethane, and acetone; and / or, the titanium powder is high-purity industrial titanium powder with a purity of ≥99.95%.

[0022] Further, in S2, the grinding aid is one or more of xylene, dichloromethane, and acetone; and / or, the titanium powder is high-purity industrial titanium powder with a purity of ≥99.95%.

[0023] Further, in S2, high-speed grinding is carried out for 2 - 8 h at room temperature under the condition that the rotation speed is 1000 - 3000 rpm.

[0024] Further, in S3, the powder filler is one or more of talc powder, fumed silica, titanium dioxide, and nano-aluminum oxide; and / or, the mixed solvent is a mixed solvent of polar and non-polar solvents.

[0025] Further, in S5, coat it on the surface of the substrate, and place it in a blast drying oven at 100 - 150 °C for 5 - 12 h to obtain a cured coating.

[0026] Further, in S5, the thickness of the cured coating is 100 ± 10 μm.

[0027] Further, in S5, the substrate is Q235 carbon steel after surface pretreatment.

[0028] A nano-titanium-organosilicon modified epoxy resin anti-corrosion coating of the present invention is prepared by the preparation method described in any of the above solutions.

[0029] Application of the nano-titanium-organosilicon modified epoxy resin anti-corrosion coating described in the above solution of the present invention in the surface protection of equipment in an offshore oil and gas platform.

[0030] In the above technical solution:

[0031] 1. When synthesizing the organosilicon modified epoxy resin, the epoxy resin needs to be dehydrated under vacuum to ensure a stable modified organosilicon modified epoxy resin is obtained.

[0032] 2. When synthesizing the nano-titanium functional filler, the self-rotation speed of the high-energy ball mill is 1000 - 3000 rpm, and the preferred grinding time is 2 - 8 h, ensuring that the grinding spheres can fully contact and extrude the titanium powder, organosilicon, and grinding aid. The mechanical energy generated destroys and crushes the titanium particles, making their particle size nano-sized, and enabling the organosilicon resin to fully coat the surface of the nano-titanium particles.

[0033] 3. When formulating the coating, a polar and non-polar mixed solvent is used to ensure uniform mixing of the organosilicon modified epoxy resin and the functional filler. The polar solvent is, for example, one or more of N,N-dimethylformamide (DMF), n-butanol, cyclohexanone, and dichloromethane, and the non-polar solvent is, for example, one or more of toluene and xylene.

[0034] 4. The preferred coating curing conditions are to place it in a forced-air drying oven at 100 - 150 °C for 5 - 12 h. The resin cross-linking curing reaction rate and the solvent evaporation rate inside the coating are moderate, and the coating has sufficient time to level during curing, reducing internal defects after complete curing.

[0035] Features of the present invention:

[0036] Feature 1: Using the organosilicon modified epoxy resin as the organosilicon modified epoxy resin of the coating can solve the problem of poor high-temperature resistance of traditional epoxy resin coatings. The organosilicon resin has Si-O-Si bonds as the main molecular chain segments, with a high bond energy. After curing, it forms a main cross-linked network structure dominated by Si-O, having good high-temperature resistance and weather resistance. Modifying the epoxy resin with the organosilicon resin can effectively improve the high-temperature resistance of the resin. In the present invention, through a simple and easy-to-operate synthesis process, an interpenetrating network structure is formed by mechanical blending of the organosilicon resin molecular chain segments and the epoxy resin molecular chain segments to prepare a stable organosilicon-epoxy resin system as the organosilicon modified epoxy resin of the composite coating, thereby improving the high-temperature resistance of the matrix epoxy resin.

[0037] Feature 2: The nano-titanium functional filler prepared by high-energy ball milling method has excellent dispersibility in silicone-modified epoxy resin. The raw material titanium powder, silicone resin and grinding aid are put into a high-energy ball mill. The balls collide with the raw materials by rolling. During this period, the titanium powder is impacted and broken, and the particle size is reduced to the nano-scale size, and the surface energy is greatly increased. At the same time, the balls collide with each other to generate a relatively high energy, realizing the coating of the metal particles by the silicone resin, and thus obtaining the nano-titanium functional filler. When the filler is fully mixed with the silicone-modified epoxy resin, the silicone resin-coated titanium particles can effectively reduce the surface energy and interaction of the nano-particles, hinder the agglomeration between the nano-titanium particles, and improve the dispersibility in the silicone-modified epoxy resin. In this way, the problem of poor dispersibility of the nano-functional filler in the silicone-modified epoxy resin is solved, and the sedimentation rate can be slowed down, so that the quality of the coating can be guaranteed during long-term storage.

[0038] Feature 3: The addition of the nano-titanium functional filler can effectively reduce the defects generated inside the coating during curing, and improve the long-term corrosion resistance, alternating stress resistance and service life of the coating. When the nano-titanium functional filler is uniformly dispersed in the coating, fewer micropores and cracks are generated during the rapid curing process of the coating, thereby reducing the channels for the penetration and diffusion of corrosive media after entering the coating. Since titanium has stable chemical properties and strong corrosion resistance, it can effectively block the corrosive media. At the same time, nano-titanium has higher thermal conductivity compared with silicone-modified epoxy resin. In a high-temperature environment, due to the uniform dispersion of nano-titanium in the coating, heat can be effectively conducted, reducing the coating defects caused by heat concentration, so that the composite coating can still maintain anti-corrosion performance in a long-term high-temperature environment.

[0039] Therefore, the beneficial effects of the present invention are as follows:

[0040] 1. The present invention synthesizes a silicone-modified epoxy resin with good high-temperature resistance as the silicone-modified epoxy resin of the coating, which can effectively cope with the complex corrosion factors of harsh marine environment and high temperature, and improve the service life of the coating.

[0041] 2. The present invention uses the high-energy ball milling method to prepare nano-titanium with excellent dispersion performance in the silicone-modified epoxy resin as a functional filler, which provides an effective barrier protection for the coating while reducing the internal defects of the coating.

[0042] 3. The present invention utilizes the good high-temperature resistance of the silicone-modified epoxy resin and the synergistic protection effect generated by the good dispersion barrier and thermal conductivity of the nano-titanium functional filler to prepare a high-temperature resistant coating with excellent comprehensive performance and capable of providing long-term anti-corrosion protection for high-temperature marine equipment.

[0043] 4. The nano-titanium functional filler prepared by the high-energy ball milling method in the present invention has a low cost and great industrialization potential. This nano-titanium functional filler has good compatibility with the organosilicon-modified epoxy matrix resin. After curing, the coating prepared from the nano-composite modified epoxy coating has fewer internal defects and is denser than the traditional composite modified epoxy coating. It has strong corrosion resistance, and due to the uniform distribution of the nano-titanium functional filler inside the coating, the coating has excellent thermal conductivity, thereby improving the high-temperature resistance of the coating. Description of the Drawings

[0044] Figure 1 It is the infrared spectrogram of methylphenyl silicone resin (SL), nano-titanium functional filler (STiN) and raw material titanium powder (Ti).

[0045] Figure 2 It is the transmission electron microscope image of the nano-titanium functional filler (STiN).

[0046] Figure 3 It is the broken line graph of the water absorption rate of the coating for 240 h.

[0047] Figure 4 It is the electrochemical impedance spectroscopy diagram of the coating after soaking for 360 h.

[0048] Figure 5 It is the coating resistance R fitted from the electrochemical impedance test data of the coating after soaking for 360 h c Bar graph.

[0049] Figure 6 It is the bar graph of the low-frequency impedance modulus of the electrochemical impedance test of the coating after the high-temperature - high-humidity - high-salt cycle experiment of the coating.

[0050] Figure 7 It is the optical photograph of the coating surface morphology after the high-temperature - high-humidity - high-salt cycle experiment of the coating. Detailed Embodiments

[0051] The following describes the present invention in detail with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention.

[0052] Example 1

[0053] A preparation method of a nano-titanium - organosilicon modified epoxy resin anti-corrosion coating in this example includes the following steps:

[0054] Step 1: Uniformly mix 200 g of epoxy resin with 20 g of xylene solvent, add 200 g of methylphenyl silicone resin and dehydrate it under vacuum for 1 h. Add 12 g of silane coupling agent KH550 and 3 g of dibutyltin dilaurate, heat up to 90 °C and stir evenly for 2 h to obtain organosilicon-modified epoxy resin, and the measured solid content is about 95.4%.

[0055] Step 2: Synthesis of nano-titanium filler: Put 500 g of high-purity industrial titanium powder (purity ≥ 99.95%), 500 g of methylphenyl silicone resin and grinding aids into a high-energy ball mill. Titanium powder, silicone and grinding aid xylene are ground at room temperature and a rotation speed of 1600 rpm for 4 h to obtain a black paste, which is the nano-titanium functional filler (STiN).

[0056] Step 3: First, take 130 g of organosilicon-modified epoxy resin, 11 g of talcum powder, 1.8 g of R972 powder, a dispersant, a leveling agent and an antifoaming agent with a mass fraction of 0.5% of the organosilicon-modified epoxy resin, add them to a mixed solvent of 30 g of xylene and 10 g of n-butanol, and place them in a high-speed disperser and stir at 3000 rpm at room temperature for 1 h to obtain a composite slurry.

[0057] Step 4: Add a T31-type phenolic amine curing agent with a mass fraction of 20% of the total mass of the coating and mix and stir evenly. Coat the curing system on the surface of Q235 carbon steel with a size of 60 mm × 30 mm × 3 mm after pretreatment, and place it in a blast drying oven at 100 °C for 6 h to obtain a cured coating. The thickness of the cured coating is 100 ± 10 μm.

[0058] Figure 1 : Infrared spectra of methylphenyl silicone resin (SL), prepared titanium nanoparticles (STiN) and raw material titanium powder (Ti). Among them, the characteristic peak at 1064 cm-1 in the infrared spectrum of SL corresponds to the stretching vibration absorption peak of organosilicon Si-O-Si. The above-mentioned group also appears in the infrared spectrum of STiN, and titanium oxides appear at 650 cm -1 and 472 cm -1 indicating that the high-energy ball milling technology enables the grinding aid SL to successfully coat the surface of titanium particles.

[0059] Figure 2 : Transmission electron micrograph of the prepared STiN. It can be seen that the raw material Ti is ground to a nanoscale particle size by high-energy ball milling, and the morphology of the nano-titanium functional filler is a relatively thin nanosheet.

[0060] Example 2

[0061] This example is basically the same as Example 1, except that in Step 1, 300 g of methylphenyl silicone resin is added and dehydrated under vacuum for 1 h.

[0062] Example 3

[0063] This example is basically the same as Example 2, except that in step 3, a nano-titanium functional filler with a percentage content of 10% of organosilicon-modified epoxy resin needs to be additionally added, and it is placed in a high-speed disperser and stirred at a speed of 2400 rpm at room temperature for 4 h to obtain a nano-titanium-organosilicon-modified epoxy coating.

[0064] Example 4

[0065] This example is basically the same as Example 3, except that in step 3, a nano-titanium functional filler with a percentage content of 12% of organosilicon-modified epoxy resin needs to be additionally added, and it is placed in a high-speed disperser and stirred at a speed of 2400 rpm at room temperature for 4 h to obtain a nano-titanium-organosilicon-modified epoxy coating.

[0066] Example 5

[0067] This example is basically the same as Example 3, except that in step 3, a nano-titanium functional filler with a percentage content of 15% of organosilicon-modified epoxy resin needs to be additionally added, and it is placed in a high-speed disperser and stirred at a speed of 2400 rpm at room temperature for 4 h to obtain a nano-titanium-organosilicon-modified epoxy coating.

[0068] Comparative Example 1

[0069] E44 epoxy resin was used and mixed and stirred evenly with T31 curing agent. The curing system was coated on the surface of Q235 carbon steel with a size of 60 mm × 30 mm × 3 mm after surface sandblasting treatment, and placed in a blast drying oven at 80 °C for 4 h to obtain a cured coating, and the coating thickness was 100 ± 10 μm.

[0070] Analysis of test results

[0071] 1. Pull-off adhesion experiment

[0072] The standard reference for the pull-off adhesion experiment of all example coatings is GB / T 5210-2006, the test instrument is PosiTest ATA-B pull-off adhesion tester, and the test results are shown in Table 1.

[0073] In Example 1 and Example 2, the organosilicon-modified epoxy resin coating has good substrate adhesion.

[0074] From the test results of Example 3, Example 4 and Example 5, it can be seen that adding an appropriate amount of nano-titanium polymer functional filler does not affect the adhesion of the organosilicon-modified epoxy resin coating.

[0075] Table 1 Test results of the pull-off adhesion experiment of the coating

[0076]

[0077] 2. Coating water absorption rate experiment

[0078] The test standard for the water absorption rate of the coatings in all examples and comparative examples refers to HG / T 3344-2012. After testing the dry weight of the cured sample coating, it was immersed in a 3.5wt% sodium chloride solution. Then, it was taken out at specific intervals, the surface water was wiped off, and the weight was measured to calculate the water absorption rate. The test duration was 240h.

[0079] The test results are as shown in the appendix Figure 3 As shown, all coatings reached the water absorption saturation state after 24h. Comparative example 1 (epoxy resin cured coating) had the highest saturated water absorption rate. From the test results of example 1 and example 2, it can be seen that the saturated water absorption rate of the silicone-modified epoxy resin coating decreased. This is because the introduction of methylphenyl silicone resin modified the epoxy resin, resulting in a reduction in curing defects and an improvement in the water repellency of the coating.

[0080] From the test results of example 3, example 4 and example 5, it can be seen that the introduction of an appropriate amount of nano-titanium polymer functional filler can further reduce the water absorption rate of the coating. This is because the functional filler has good dispersion compatibility in the silicone-modified epoxy resin, improves the density of the cured coating, and plays a role in blocking the diffusion of water molecules in the cured coating.

[0081] 3. Electrochemical test

[0082] The corrosion resistance of the coatings in all examples and comparative examples was tested by electrochemical impedance spectroscopy. The test platform was a Metrohm PGSTAT302N electrochemical workstation. A three-electrode system was selected. The carbon steel sheet coated with the coating was used as the working electrode, the test area radius was 1cm, the saturated calomel electrode was used as the reference electrode, the platinum sheet electrode was used as the counter electrode, and a 3.5wt% sodium chloride solution was used as the electrolyte. The test frequency range was 10 5 -10 -2 Hz, the amplitude of the sine signal was 10mV. Electrochemical impedance tests were carried out on the coatings in all examples and comparative examples after being immersed in a 3.5wt% sodium chloride solution for 360h. The test results were fitted using ZView2 software.

[0083] The Bode diagram of the electrochemical impedance spectrum is as shown in the appendix Figure 4 As shown, in the Bode diagram, the magnitude of the low-frequency impedance modulus |Z| 0.01Hz intuitively reflects the corrosion resistance of the coating. After being immersed in a 3.5wt% sodium chloride solution for 360h, the low-frequency impedance modulus |Z| of the coating in comparative example 1 0.01Hz was the lowest. From the test results of example 1 and example 2, it can be seen that the long-term corrosion resistance of the silicone-modified epoxy resin coating was significantly improved compared with the epoxy coating. This is because the introduction of the silicone prepolymer molecular chain segment reduced the curing defects of the epoxy resin, improved the water repellency, and enhanced the barrier performance to the corrosive medium.

[0084] From the test results of Example 3, Example 4 and Example 5, it can be seen that introducing an appropriate amount of nano-titanium polymer functional filler can further enhance the anti-corrosion performance of the coating. This is because the functional filler has good dispersion compatibility in the silicone-modified epoxy resin, improving the density of the cured coating. Titanium nanoparticles with good chemical stability can effectively block the diffusion of corrosive media to the coating-metal substrate interface, improving the long-term anti-corrosion performance of the coating.

[0085] The resistance value R of the coatings of the examples and comparative examples obtained by fitting the electrochemical impedance data c As shown in the appendix Figure 5 As shown. Among them, the resistance value R of the coating in Example 3 c is the highest, and the anti-corrosion performance is the best.

[0086] 4. High-temperature, high-humidity and high-salt corrosion test

[0087] The high-temperature, high-humidity and high-salt corrosion resistance of all the coatings of the examples was tested by a high-temperature-high-humidity-high-salt cycle experiment. In the high-temperature experiment, the coating samples were placed in a muffle furnace and burned in air at 300 °C for 24 h. The high-humidity and high-salt experiment used a neutral salt spray experiment. The experimental standard referred to GB / T 31588.1-2015, the temperature was set at 35 °C, and the salt spray solution was a 5% wt% sodium chloride solution. The coating samples after air burning were placed in a salt spray chamber for 24 h, and the samples were taken out for electrochemical impedance spectroscopy test analysis of the barrier performance. This cycle was repeated until the coating completely failed. The electrochemical test results are shown in the appendix Figure 6 As shown.

[0088] The coatings of Example 1 and Example 2 completely failed after five high-temperature-high-humidity-high-salt cycle experiments. The coating morphology is shown in the appendix Figure 7 As shown. Due to being in a high-temperature environment for a long time, the resin molecules decomposed thermally on the coating surface, resulting in a large number of cracks. Obvious corrosion sites indicate that there are also defects inside the coating. The neutral salt spray can quickly diffuse through the coating to the metal substrate interface, causing corrosion.

[0089] Example 3, Example 4 and Example 5 underwent six high-temperature-high-humidity-high-salt cycle experiments and still maintained a certain barrier performance, indicating that introducing an appropriate amount of nano-titanium polymer functional filler enhances the high-temperature anti-corrosion performance of the coating. This is because the functional filler has good dispersion compatibility in the silicone-modified epoxy resin, improving the crosslinking degree of resin curing. The uniformly dispersed nano-titanium particles also increase the thermal conductivity of the cured coating, avoiding the destruction of the coating structure caused by heat concentration to a certain extent, and at the same time blocking the diffusion of corrosive media. The coating morphologies of Example 3, Example 4 and Example 5 after six-cycle tests are shown in the appendix Figure 7As shown, there are cracks on the coating surface but no corrosion sites. Among them, the coating in Example 3 has the highest impedance modulus, and there are fewer cracks on the coating surface, showing relatively excellent high-temperature corrosion protection performance.

[0090] The above are only the preferred embodiments of the present invention and do not constitute any formal limitations on the present invention. Although the present invention has been described through the above embodiments, for those skilled in the art, any adjustments, equivalent modifications, and simple improvements made without departing from the spirit, principles, and technical solution requirements of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a nano-titanium-organosilicon modified epoxy resin anti-corrosion coating, characterized in that: The following steps are involved: S1. The epoxy resin and the xylene solvent are uniformly mixed, the silicone resin is added and the water is removed under vacuum; the silane coupling agent and dibutyltin dilaurate are added, the temperature is raised to 80-100°C and stirred at a uniform speed to obtain a silicone-modified epoxy resin; S2. The titanium powder, silicone resin and grinding aid are put into a high-energy ball mill, and the titanium powder, silicone resin and grinding aid are ground at high speed at room temperature and a rotation speed of 1000-3000rpm to obtain a black paste, which is a nano-titanium functional filler; S3. First, the organosilicon-modified epoxy resin, powder filler, dispersant, leveling agent and defoamer prepared in S1 are added to a mixed solvent, placed in a high-speed disperser and stirred at a speed of 2000-3000 rpm at room temperature to obtain a mixed slurry; then, a nano-titanium functional filler is added, placed in a high-speed disperser and stirred at a speed of 2000-3000 rpm at room temperature to obtain a nano-titanium-organosilicon-modified epoxy resin coating; S4. Add an amine curing agent to the coating and mix and stir evenly, and finally apply it on the surface of the substrate and dry to obtain a cured coating.

2. The method for preparing the nano-titanium-organic silicon modified epoxy resin anti-corrosion coating according to claim 1, characterized in that: In S1, the epoxy resin type is one or more of E20, E44, E51, and F44; and / or, in S1 and S2, the silicone resin is one or more of polymethyl silicone resin, polyaryl silicone resin, and methylphenyl silicone resin.

3. The method for preparing the nano-titanium-organosilicon modified epoxy resin anti-corrosion coating according to claim 1, characterized in that: In S1, the mass ratio of the silicone resin to the epoxy resin is (1-2):1; and / or, in S2, the mass ratio of the titanium powder to the silicone resin is 5:(2-6).

4. The method for preparing the nano-titanium-organic silicon modified epoxy resin anti-corrosion coating according to claim 1, characterized in that: In S1, the silane coupling agent is one or more of KH550, KH560, KH570, and KH590.

5. The method for preparing the nano-titanium-organic silicon modified epoxy resin anti-corrosion coating according to claim 1, characterized in that: In S2, the grinding aid is one or more of xylene, dichloromethane and acetone; and / or the titanium powder is high-purity industrial titanium powder with a purity of ≥99.95%.

6. The method for preparing the nano-titanium-organosilicon modified epoxy resin anti-corrosion coating according to claim 1, characterized in that: In S3, the powder filler is one or more of talcum powder, fumed silica, titanium dioxide, and nano-alumina; and / or the mixed solvent is a mixed solvent of polar and non-polar solvent.

7. The method for preparing the nano-titanium-organic silicon modified epoxy resin anti-corrosion coating according to claim 1, characterized in that: In S5, the coating is applied on the surface of the substrate and placed in a forced air drying oven at 100-150° C. for 5-12 hours to obtain a cured coating.

8. The method for preparing the nano-titanium-organic silicon modified epoxy resin anti-corrosion coating according to claim 1, characterized in that: In S5, the coating thickness after curing is 100±10 μm.

9. A nano-titanium-organic silicon modified epoxy resin anti-corrosion coating, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the nano-titanium-organic silicon modified epoxy resin anti-corrosion coating according to claim 9 in the surface protection of equipment in offshore oil and gas platforms.

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