A modified magnesium phosphate cement anticorrosive material and its use method and application

Abstract

The present invention relates to the technical field of cement-based anticorrosive materials, and specifically discloses a modified magnesium phosphate cement anticorrosive material and a method and application thereof. The anticorrosive material comprises the following components: 100 parts by weight of modified magnesium phosphate cement, 3 to 15 parts by weight of a retarder, 1 to 10 parts by weight of an epoxy resin glue, 0.5 to 5 parts by weight of metakaolin, and 15 to 20 parts by weight of water. The modified magnesium phosphate cement comprises dead-burned magnesium oxide and modified phosphate in a mass ratio of 1 to 4:1. The raw materials for preparing the modified phosphate include nano-alumina, sodium citrate and phosphate, and the mass ratio of the three is 0.5 to 1.5: 0.5 to 1.5: 20 to 25. The epoxy resin glue comprises uncured epoxy resin glue and a curing agent. The anticorrosive material provided by the present invention has the technical advantages of strong bonding performance and excellent anticorrosive performance, and can better provide protection for steel structures serving in marine environments.

Description

Technical Field

[0001] The invention relates to the technical field of cement-based anticorrosive materials, and in particular to a modified magnesium phosphate cement anticorrosive material and a use method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] With the increasing attention paid to clean energy around the world, the development of onshore photovoltaics has reached saturation, while the vast area of ​​the ocean and the rich solar radiation resources provide huge development potential for offshore photovoltaic power generation. Offshore photovoltaics are rapidly becoming a new hotspot for the development and utilization of renewable energy. However, the development of offshore photovoltaics also faces many challenges. In particular, the complex marine environment (such as high salt spray, wind and wave scouring, high humidity, etc.) significantly aggravates the corrosion of the photovoltaic system matrix, seriously threatening the durability and safety of the equipment.

[0004] Magnesium phosphate materials, as special cementitious materials formed by dead-burned magnesium oxide and phosphate, have been widely used in the field of anti-corrosion coatings due to their advantages such as fast coagulation and hardening, high early strength, good volume stability, and the ability to undergo phosphating reaction with the steel surface to form a passivation film. In the marine environment, magnesium phosphate materials can significantly improve the anti-corrosion performance of steel structures by virtue of their dual physical and chemical protective effects. However, the bonding performance and impact resistance of magnesium phosphate coatings still need to be further optimized to cope with the problems caused by mechanical shock and long-term use under complex marine conditions. Summary of the invention

[0005] In view of the above problems, the present invention provides a modified magnesium phosphate cement anti-corrosion material and a method and application thereof, which has the technical advantages of strong bonding performance and excellent anti-corrosion performance, and can better provide protection for steel structures serving in marine environments. Specifically, the technical solution of the present invention is as follows.

[0006] In the first aspect, the present invention provides a modified magnesium phosphate cement anticorrosive material, the raw materials of which include the following components: 100 parts by weight of modified magnesium phosphate cement, 3 to 15 parts by weight of retarder, 1 to 10 parts by weight of epoxy resin glue, 0.5 to 5 parts by weight of metakaolin, and 15 to 20 parts by weight of water. Wherein: the modified magnesium phosphate cement includes dead-burned magnesium oxide and modified phosphate in a mass ratio of 1 to 4:1. The raw materials for preparing the modified phosphate include nano-alumina, sodium citrate and phosphate, and the mass ratio of the three is 0.5 to 1.5: 0.5 to 1.5: 20 to 25. It also includes a curing agent for the epoxy resin glue, and the mass ratio of the curing agent to the epoxy resin glue is 1: 3 to 3.5.

[0007] Furthermore, the retarder includes at least one of borax, boric acid, zinc sulfate and the like.

[0008] Furthermore, the phosphate includes at least one of ammonium dihydrogen phosphate, potassium dihydrogen phosphate, etc.

[0009] Furthermore, the curing agent includes one or more of polyether amines, aromatic amines, fatty amines, polyamides, phenolic amines, and the like.

[0010] Furthermore, the modified phosphate is prepared by the following method:

[0011] (1) The nano-alumina is dispersed in water to form a suspension, and then the sodium citrate is added for ultrasonic treatment to obtain a modified nano-alumina suspension for standby use.

[0012] (2) Dissolve the phosphate in water, adjust the pH of the system to a neutral range, and then add the modified nano-alumina suspension for stirring. After completion, perform high-speed shear dispersion on the obtained reaction solution, and obtain a homogeneous slurry after standing for standby.

[0013] (3) spray drying the homogenized slurry to obtain the modified phosphate.

[0014] Furthermore, in step (1), the ultrasonic treatment time is 20-35 min, the frequency is 20-30 kHz, and the power is 100-150 W, so that the surface of the nano-alumina is fully activated to avoid agglomeration and enhance its reaction activity.

[0015] Furthermore, in step (2), the mass fraction of the solution formed by dissolving the phosphate in water is 20-25%.

[0016] Furthermore, in step (2), the pH in the neutral range is 6.5-7.5. Optionally, a buffer such as ammonia water or citric acid is added to adjust the pH of the system to the neutral range.

[0017] Furthermore, in step (2), the stirring treatment time is 15 to 25 minutes.

[0018] Furthermore, in step (2), the rotation speed of the shear dispersion treatment is 3000-7000 rpm, and the treatment time is 8-15 min. Optionally, the standing time is 2-3 hours to remove air bubbles in the slurry and enhance the stability of the slurry.

[0019] Furthermore, the epoxy resin glue also contains triethanolamine, and the mass ratio of the epoxy resin glue to the triethanolamine is 3-9:0.5-1. Before use, the epoxy resin glue and the triethanolamine are mixed, and then the curing agent is added and mixed. Modifying the epoxy resin glue by triethanolamine can not only improve the curing synchronization of the epoxy resin and the magnesium phosphate cement, but also improve the low-temperature curing efficiency of the epoxy resin.

[0020] Furthermore, the epoxy resin glue also contains a dye, and the mass ratio of the epoxy resin glue to the dye is 3-9:0.5-1. Before use, the dye is added to the epoxy resin glue and mixed evenly.

[0021] Furthermore, the coloring agent includes at least one of iron oxide green, iron oxide black, iron oxide red, iron oxide blue, rutile titanium dioxide, etc.

[0022] In a second aspect, the present invention provides a method for using the modified magnesium phosphate cement anticorrosive material, comprising the following steps:

[0023] (S1) The epoxy resin glue is mixed with the curing agent, and then mixed with the modified magnesium phosphate cement, the retarder, the metakaolin, and water to obtain a slurry. Slurries containing different dyes are prepared in the same manner to obtain slurries of different colors for later use.

[0024] (S2) Applying one color of the slurry on the surface of the substrate to form a first protective layer after solidification, and then applying another color of the slurry on the first protective layer to form a second protective layer after solidification. This is repeated until all colors of the slurry are applied, thereby forming a protective layer with a color gradient on the surface of the substrate.

[0025] Furthermore, in step (S2), the greater the color difference between adjacent protective layers, the better, so as to more timely and quickly identify the degree of damage to the protective layer. For example, from the outside to the inside, they are green, blue, black, white, etc. Optionally, in step (S2), the thickness of each protective layer is 1-2 mm, and other suitable thicknesses can be selected as needed.

[0026] In a third aspect, the present invention provides the application of the modified magnesium phosphate cement anti-corrosion material in the fields of construction engineering, marine engineering, water conservancy and hydropower engineering, etc.

[0027] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0028] (1) The magnesium phosphate cement anticorrosive material of the present invention can be directly coated on the surface of the metal substrate to form a protective layer, and can also react with the metal substrate surface to form a passivation film to prevent the penetration of corrosive media. To this end, the present invention first modifies the phosphate by sodium citrate and nano-alumina, and proposes a modification process. On the one hand, the sodium citrate can play a role in repairing the microcrack defects of the passivation film. This is because when microcracks appear in the passivation film, the unprotected metal surface will be exposed or a capillary structure will be formed at the crack. Sodium citrate can quickly enter the crack area and react with the exposed metal ions or film defect areas, that is, the carboxyl and hydroxyl active groups of the sodium citrate molecules react with metal ions and phosphate ions to form a stable complex (such as a citric acid metal complex) to fill these defects, enhance the repair ability of the passivation film, and improve the stability and anti-permeability of the protective layer. On the other hand, the carboxylate contained in the sodium citrate can form a complex with the magnesium and aluminum ions provided by the modified magnesium phosphate cement, adjust the solubility and dispersibility of the phosphate, avoid precipitation or uneven distribution, and further improve the stability of the anti-corrosion material. On the other hand, the nano-alumina also significantly improves the hardness and wear resistance of the anti-corrosion material by filling the micropores of the anti-corrosion material, and reacts with the phosphate ions in the phosphate to form an aluminum phosphate complex, which can further strengthen the structure of the anti-corrosion material to form a denser passivation film, reduce the penetration path of the corrosive medium, and further improve the anti-corrosion performance of the protective layer.

[0029] (2) The magnesium phosphate cement anti-corrosion material of the present invention is also added with modified epoxy resin. First, the epoxy resin forms a three-dimensional cross-linked structure during the curing process, and interpenetrates with the microporous structure of the magnesium phosphate cement, thereby filling the tiny pores between the matrix and the protective layer, which is beneficial to reduce the penetration of moisture, oxygen and corrosive media, and further isolate the contact between the external corrosive media and the metal substrate. Second, the epoxy resin can also enhance the interfacial adhesion between the protective layer and the matrix through the mechanical interlocking effect between the epoxy resin and the microporous structure of the magnesium phosphate cement, thereby reducing the shedding of the protective layer. Third, the epoxy resin can enhance the overall hardness and wear resistance of the protective layer, and improve the ability to resist external impacts (such as wave impact, friction, etc.). Fourth, the epoxy resin can also effectively coat the surface of dead-burned magnesium oxide and phosphate, so that hydrogen bonds and other interactions occur between dead-burned magnesium oxide and phosphate molecules to form micelle-like structures, thereby increasing the solubility of magnesium oxide and phosphate in the mixing water, thereby helping to disperse magnesium oxide and phosphate, inhibiting the phenomenon of local supersaturation, reducing the formation of large crystals or pores, and improving the reaction uniformity of the magnesium phosphate system, ensuring the smooth progress of the hydration reaction of magnesium phosphate cement and the curing process of epoxy resin, and helping to form a more compact passivation film and protective layer structure, further improving the corrosion resistance and mechanical properties of the protective layer. Fifth, the epoxy resin glue modified by triethanolamine can still maintain a good curing rate under low temperature conditions. In addition, the heat released by magnesium phosphate cement during the hydration process provides additional temperature-raising stimulation for epoxy resin, and triethanolamine as a thermosensitive accelerator can further enhance this thermosensitive reaction, thereby promoting the cross-linking reaction of epoxy resin, making the curing process of epoxy resin and magnesium phosphate cement more synchronous, so that the anti-corrosion material of the present invention can still be efficiently cured in a cold environment and form a high-performance protective layer.

[0030] (3) The present invention also proposes to prepare anti-corrosion coatings of different colors and form a protective layer with color gradient changes on the surface of the substrate. This provides a more intuitive and practical method for detecting damage to the protective layer. When the protective layer is damaged (such as scratches, impacts, wear, cracks, etc.), by observing the color of the damaged position, it is possible to quickly identify whether the part is damaged and the current degree / depth of the damage, so as to facilitate timely detection of the damaged position and repair before the substrate surface is exposed, thereby preventing the damage from further expanding and causing corrosion of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein:

[0032] Figure 1This is a sample picture of the modified phosphate prepared in Example 1 below.

[0033] Figure 2 This is a sample picture of the modified magnesium phosphate cement anti-corrosion material prepared in the following Example 1.

[0034] Figure 3 This is a bonding strength test diagram of the modified magnesium phosphate cement anti-corrosion material prepared in the following Example 1.

[0035] Figure 4 The following is a graph showing the anti-corrosion performance test of Example 1.

[0036] Figure 5 This is a sample of modified magnesium phosphate cement anti-corrosion material prepared in the following Example 5. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0038] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. The reagents or raw materials used in the present invention can be purchased through conventional channels. Unless otherwise specified, the reagents or raw materials used in the present invention are used in a conventional manner in the art or in accordance with the product instructions. In addition, any method and material similar or equivalent to the described content can be applied to the method of the present invention.

[0039] Example 1

[0040] A preparation method of a modified magnesium phosphate cement anticorrosive material comprises the following steps:

[0041] (1) Prepare the raw materials in the following proportions: 0.9 parts by weight of nano-alumina, 1.2 parts by weight of sodium citrate, and 23 parts by weight of phosphate (potassium dihydrogen phosphate powder).

[0042] (2) The nano-alumina is dispersed in water and stirred at a rate of 300 rpm for 15 minutes to obtain a suspension. Then the sodium citrate is added and ultrasonic treatment is performed for 30 minutes at an ultrasonic frequency of 25 kHz and an ultrasonic power of 100 W. After completion, a modified nano-alumina suspension is obtained and set aside.

[0043] (3) The phosphate is dissolved in water to form a phosphate solution with a mass fraction of 23%, and then ammonia water is added to adjust the pH of the system to 7.5, and then the modified nano-alumina suspension is added and magnetically stirred for 20 minutes. After completion, the obtained reaction solution is subjected to high-speed shear dispersion treatment (speed of 6000 rpm, time of 10 minutes), and then allowed to stand for 2 hours to obtain a homogeneous slurry for standby use.

[0044] (4) The homogenized slurry is placed in a spray dryer for spray drying. The nozzle diameter of the spray dryer is 2 mm, the feed temperature is set to 25°C, the spray inlet temperature is set to 180°C, and the spray outlet temperature is set to 90°C. After completion, the modified phosphate (such as Figure 1 As shown in the figure, the dead-burned magnesium oxide powder and the modified phosphate are uniformly mixed in a mass ratio of 3.2:1 to obtain modified magnesium phosphate cement for later use.

[0045] (5) Prepare the raw materials in the following proportions: 100 parts by weight of the modified magnesium phosphate cement prepared in this example, 7 parts by weight of retarder (borax), 10 parts by weight of epoxy resin glue, 4 parts by weight of 200-mesh kaolin, 16 parts by weight of water, and polyetheramine epoxy resin curing agent D230 (produced by Kunshan Jiulimei Electronic Materials Co., Ltd.), with the mass ratio of the epoxy resin curing agent to the epoxy resin glue being 1:3.3.

[0046] (6) The epoxy resin glue and the curing agent are mixed and stirred evenly, and then mixed with the modified magnesium phosphate cement, the retarder, the metakaolin and the water and stirred evenly to obtain the anticorrosive material (such as Figure 2 as shown).

[0047] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The measured corrosion current density was 6.225×10 -7 A.cm -2 .

[0048] (2) The anti-corrosion material prepared in this embodiment was tested for adhesion strength according to GB / T-5210-2006 "Pull-off adhesion test for paint and varnish" (e.g. Figure 3 As shown), the higher the value, the better the bonding performance and the ability to resist impact and peeling. The measured result is 5.172MPa.

[0049] (3) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm, and then a YWX / Q-250 salt spray tester was used to perform a salt spray resistance test on the anti-corrosion material prepared in this example. It can be seen that there is no sign of rust on the surface of the anti-corrosion material (such as Figure 4 Left), while the surface of the Q235 steel plate without the anti-corrosion material showed serious corrosion (such as Figure 4 Right picture), which shows that the anti-corrosion material has excellent salt spray corrosion resistance.

[0050] Example 2

[0051] A preparation method of a modified magnesium phosphate cement anticorrosive material comprises the following steps:

[0052] (1) Prepare the raw materials in the following proportions: 0.5 parts by weight of nano-alumina, 0.5 parts by weight of sodium citrate, and 20 parts by weight of phosphate (potassium dihydrogen phosphate powder).

[0053] (2) The nano-alumina is dispersed in water and stirred at a rate of 240 rpm for 20 minutes to obtain a suspension. Then the sodium citrate is added and ultrasonic treatment is performed for 20 minutes at an ultrasonic frequency of 30 kHz and an ultrasonic power of 110 W. After completion, a modified nano-alumina suspension is obtained for standby use.

[0054] (3) The phosphate is dissolved in water to form a phosphate solution with a mass fraction of 20%, and then ammonia water is added to adjust the pH of the system to 7.0, and then the modified nano-alumina suspension is added and magnetically stirred for 15 minutes. After completion, the obtained reaction solution is subjected to high-speed shear dispersion treatment (speed of 3000 rpm, time of 15 minutes), and then allowed to stand for 3 hours to obtain a homogeneous slurry for standby use.

[0055] (4) The homogenized slurry is placed in a spray dryer for spray drying. The nozzle diameter of the spray dryer is 2 mm, the feed temperature is set to 25° C., the spray inlet air temperature is set to 180° C., and the spray outlet temperature is set to 90° C. After completion, the modified phosphate is obtained in powder form. The dead-burned magnesium oxide powder and the modified phosphate are mixed uniformly in a mass ratio of 1:1 to obtain modified magnesium phosphate cement, which is then used for standby.

[0056] (5) Prepare the raw materials in the following proportions: 100 parts by weight of the modified magnesium phosphate cement prepared in this example, 3 parts by weight of a retarder (zinc sulfate), 1 part by weight of the modified epoxy resin adhesive prepared in this example, 0.5 parts by weight of 200-mesh kaolin, 15 parts by weight of water, and a polyetheramine epoxy resin curing agent D230 (produced by Kunshan Jiulimei Electronic Materials Co., Ltd.), the mass ratio of which to the epoxy resin adhesive is 1:3.

[0057] (6) The epoxy resin glue is mixed with the curing agent and stirred evenly, and then mixed with the modified magnesium phosphate cement, retarder, metakaolin and water and stirred evenly to obtain the anti-corrosion material.

[0058] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The measured corrosion current density was 6.315×10 -7 A.cm -2 (2) The bonding strength of the anti-corrosion material prepared in this embodiment was tested in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 4.629 MPa.

[0059] Example 3

[0060] A preparation method of a modified magnesium phosphate cement anticorrosive material comprises the following steps:

[0061] (1) Prepare the raw materials in the following proportions: 1.5 parts by weight of nano-alumina, 1.5 parts by weight of sodium citrate, and 25 parts by weight of phosphate (ammonium dihydrogen phosphate powder).

[0062] (2) The nano-alumina is dispersed in water and stirred at a rate of 300 rpm for 15 minutes to obtain a suspension. Then the sodium citrate is added and ultrasonic treatment is performed for 35 minutes at an ultrasonic frequency of 20 kHz and an ultrasonic power of 150 W. After completion, a modified nano-alumina suspension is obtained and set aside.

[0063] (3) The phosphate is dissolved in water to form a phosphate solution with a mass fraction of 25%, and then ammonia water is added to adjust the pH of the system to 6.5, and then the modified nano-alumina suspension is added and magnetically stirred for 25 minutes. After completion, the obtained reaction solution is subjected to high-speed shear dispersion treatment (speed of 7000 rpm, time of 8 minutes), and then allowed to stand for 3 hours to obtain a homogeneous slurry for standby use.

[0064] (4) The homogenized slurry is placed in a spray dryer for spray drying. The nozzle diameter of the spray dryer is 2 mm, the feed temperature is set to 25° C., the spray air inlet temperature is set to 180° C., and the spray outlet temperature is set to 90° C. After completion, the modified phosphate is obtained in powder form. The dead-burned magnesium oxide powder and the modified phosphate are mixed uniformly in a mass ratio of 4:1 to obtain modified magnesium phosphate cement, which is then used for standby.

[0065] (5) Prepare the raw materials in the following proportions: 100 parts by weight of the modified magnesium phosphate cement prepared in this example, 6 parts by weight of a retarder (boric acid), 3 parts by weight of an epoxy resin adhesive, 0.5 parts by weight of triethanolamine, 2 parts by weight of 200-mesh kaolin, 17 parts by weight of water, and a polyetheramine epoxy resin curing agent D230 (produced by Kunshan Jiulimei Electronic Materials Co., Ltd.), the mass ratio of which to the epoxy resin adhesive is 1:3.1.

[0066] (6) The epoxy resin glue is mixed with triethanolamine and stirred evenly, and then the curing agent is added and stirred evenly, and then the modified magnesium phosphate cement, retarder, metakaolin and water are mixed and stirred evenly to obtain the anti-corrosion material.

[0067] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The measured corrosion current density was 6.724×10 -7 A.cm -2 (2) The bonding strength of the anti-corrosion material prepared in this embodiment was tested in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 5.716 MPa.

[0068] Example 4

[0069] A preparation method of a modified magnesium phosphate cement anticorrosive material comprises the following steps:

[0070] (1) Prepare the raw materials in the following proportions: 1 part by weight of nano-alumina, 0.6 parts by weight of sodium citrate, and 22 parts by weight of phosphate (ammonium dihydrogen phosphate powder).

[0071] (2) The nano-alumina is dispersed in water and stirred at a rate of 300 rpm for 15 minutes to obtain a suspension. Then the sodium citrate is added and ultrasonic treatment is performed for 20 minutes at an ultrasonic frequency of 25 kHz and an ultrasonic power of 130 W. After completion, a modified nano-alumina suspension is obtained and set aside.

[0072] (3) The phosphate is dissolved in water to form a phosphate solution with a mass fraction of 22%, and then citric acid is added to adjust the pH of the system to 7.0, and then the modified nano-alumina suspension is added and magnetically stirred for 20 minutes. After completion, the obtained reaction solution is subjected to high-speed shear dispersion treatment (speed of 3000 rpm, time of 8 minutes), and then allowed to stand for 2 hours to obtain a homogeneous slurry for standby use.

[0073] (4) The homogenized slurry is placed in a spray dryer for spray drying. The nozzle diameter of the spray dryer is 2 mm, the feed temperature is set to 25° C., the spray inlet air temperature is set to 180° C., and the spray outlet temperature is set to 90° C. After completion, the modified phosphate is obtained in powder form. The dead-burned magnesium oxide powder and the modified phosphate are mixed uniformly at a mass ratio of 2.8:1 to obtain modified magnesium phosphate cement, which is then used for standby.

[0074] (5) Prepare the raw materials in the following proportions: 100 parts by weight of the modified magnesium phosphate cement prepared in this example, 15 parts by weight of a retarder (boric acid), 9 parts by weight of epoxy resin glue, 1 part by weight of triethanolamine, 5 parts by weight of 200-mesh kaolin, 20 parts by weight of water, and fatty amine epoxy resin curing agent 593 (produced by Shanghai Aotun Chemical Technology Co., Ltd.), the mass ratio of which to the epoxy resin glue is 1:3.5.

[0075] (6) The epoxy resin glue is mixed with triethanolamine and stirred evenly, and then the curing agent is added and stirred evenly, and then the modified magnesium phosphate cement, retarder, metakaolin and water are mixed and stirred evenly to obtain the anti-corrosion material.

[0076] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The measured corrosion current density was 6.559×10 -7 A.cm -2 (2) The bonding strength of the anti-corrosion material prepared in this embodiment was tested in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 5.762 MPa.

[0077] Example 5

[0078] A preparation method of a modified magnesium phosphate cement anticorrosive material comprises the following steps:

[0079] (1) Prepare the raw materials in the following proportions: 100 parts by weight of the modified magnesium phosphate cement prepared in Example 4, 15 parts by weight of a retarder (boric acid), 9 parts by weight of an epoxy resin glue, 1 part by weight of triethanolamine, 1 part by weight of a dye (red iron oxide), 5 parts by weight of 200-mesh kaolin, 20 parts by weight of water, and a fatty amine epoxy resin curing agent 593 (produced by Shanghai Aotun Chemical Technology Co., Ltd.), the mass ratio of which to the epoxy resin glue is 1:3.5.

[0080] (2) The epoxy resin glue is mixed with triethanolamine and stirred evenly, and then the curing agent and the dye are added and stirred evenly, and then the modified magnesium phosphate cement, retarder, metakaolin and water are mixed and stirred evenly to obtain a red anti-corrosion material.

[0081] (3) According to the above method, green (the dye is iron oxide green), black (the dye is iron oxide black), and white (the dye is rutile titanium dioxide) anti-corrosion materials are further prepared. Then, the red anti-corrosion material is first applied to the surface of the Q235 steel plate, and after solidification, the green, black, and white anti-corrosion materials are applied in sequence, thereby forming a protective layer with a color gradient change (from the inside to the outside, red protective layer, green protective layer, black protective layer, white protective layer, and the thickness of each protective layer is 1 mm) on the surface of the substrate, such as Figure 5 shown.

[0082] Performance test: (1) The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The measured corrosion current density was 5.734×10 -7 A.cm -2 (2) The anti-corrosion material prepared in this embodiment was tested for bonding strength in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 4.917 MPa.

[0083] Example 6

[0084] A preparation method of a modified magnesium phosphate cement anticorrosive material comprises the following steps:

[0085] (1) Mix the dead-burned magnesium oxide powder and potassium dihydrogen phosphate powder in a mass ratio of 3.2:1 to obtain magnesium phosphate cement for later use.

[0086] (2) Prepare the raw materials in the following proportions: 100 parts by weight of the magnesium phosphate cement prepared in this example, 7 parts by weight of a retarder (borax), 10 parts by weight of an epoxy resin adhesive, 4 parts by weight of 200-mesh kaolin, 16 parts by weight of water, and a polyetheramine epoxy resin curing agent D230 (produced by Kunshan Jiulimei Electronic Materials Co., Ltd.), the mass ratio of which to the epoxy resin adhesive is 1:3.3.

[0087] (3) The epoxy resin glue is mixed with the curing agent and stirred evenly, and then mixed with the modified magnesium phosphate cement, retarder, metakaolin and water and stirred evenly to obtain the anti-corrosion material.

[0088] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The corrosion current density was measured to be 2.401×10 -6 A.cm -2 (2) The bonding strength of the anti-corrosion material prepared in this embodiment was tested in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 2.140 MPa.

[0089] Example 7

[0090] The preparation of a modified magnesium phosphate cement anticorrosive material is the same as that of the above-mentioned embodiment 2, except that the modified phosphate is prepared by the following method in this embodiment:

[0091] (1) Prepare the raw materials in the following proportions: 0.5 parts by weight of nano-alumina and 20 parts by weight of phosphate (potassium dihydrogen phosphate powder).

[0092] (2) The nano-alumina is dispersed in water, and then subjected to ultrasonic treatment for 20 minutes, with an ultrasonic frequency of 30 kHz and an ultrasonic power of 110 W, to obtain a nano-alumina suspension for later use.

[0093] (3) The phosphate is dissolved in water to form a phosphate solution with a mass fraction of 20%, and then ammonia water is added to adjust the pH of the system to 7.0, and then the nano-alumina suspension is added and magnetically stirred for 15 minutes. After completion, the obtained reaction solution is subjected to high-speed shear dispersion treatment (speed of 3000 rpm, time of 15 minutes), and then allowed to stand for 3 hours to obtain a homogeneous slurry for standby use.

[0094] (4) The homogenized slurry is placed in a spray dryer for spray drying. The nozzle diameter of the spray dryer is 2 mm, the feed temperature is set to 25° C., the spray inlet air temperature is set to 180° C., and the spray outlet temperature is set to 90° C. After completion, a powdered modified phosphate is obtained.

[0095] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The measured corrosion current density was 1.431×10 -6 A.cm -2 (2) The anti-corrosion material prepared in this embodiment was tested for bonding strength in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 3.019 MPa.

[0096] Example 8

[0097] The preparation of a modified magnesium phosphate cement anticorrosive material is the same as that of the above-mentioned embodiment 1, except that the modified phosphate is prepared by the following method in this embodiment:

[0098] (1) Prepare the following raw materials in the following proportions: 1.2 parts by weight of sodium citrate and 23 parts by weight of phosphate (potassium dihydrogen phosphate powder).

[0099] (2) The phosphate is dissolved in water to form a phosphate solution with a mass fraction of 23%, and then ammonia water is added to adjust the pH of the system to 7.5, and then the sodium citrate is added and magnetically stirred for 20 minutes. After completion, the obtained reaction solution is subjected to high-speed shear dispersion treatment (speed of 6000 rpm, time of 10 minutes), and then allowed to stand for 2 hours to obtain a mixed solution for standby use.

[0100] (3) placing the mixed liquid in a spray dryer for spray drying, wherein the nozzle diameter of the spray dryer is 2 mm, the feed temperature is set to 25° C., the spray inlet air temperature is set to 180° C., and the spray outlet temperature is set to 90° C., and a powdered modified phosphate is obtained after completion.

[0101] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The measured corrosion current density was 1.201×10 -6 A.cm -2 (2) The bonding strength of the anti-corrosion material prepared in this embodiment was tested in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 3.567 MPa.

[0102] Example 9

[0103] A preparation method of a modified magnesium phosphate cement anticorrosive material comprises the following steps:

[0104] (1) Prepare the raw materials in the following proportions: 100 parts by weight of the modified magnesium phosphate cement prepared in Example 2, 3 parts by weight of a retarder (zinc sulfate), 1 part by weight of the modified epoxy resin adhesive prepared in Example 2, 15 parts by weight of water, and a polyetheramine epoxy resin curing agent D230 (produced by Kunshan Jiulimei Electronic Materials Co., Ltd.), the mass ratio of which to the epoxy resin adhesive is 1:3.

[0105] (2) The epoxy resin glue is mixed with the curing agent and stirred evenly, and then mixed with the modified magnesium phosphate cement, retarder and water and stirred evenly to obtain the anti-corrosion material.

[0106] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The corrosion current density was measured to be 8.211×10 -7 A.cm -2 (2) The anti-corrosion material prepared in this embodiment was tested for bonding strength in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 2.070 MPa.

[0107] Example 10

[0108] A preparation method of a modified magnesium phosphate cement anticorrosive material comprises the following steps:

[0109] (1) Prepare the raw materials in the following proportions: 100 parts by weight of the modified magnesium phosphate cement prepared in Example 2, 3 parts by weight of a retarder (zinc sulfate), 0.5 parts by weight of 200-mesh kaolin, 15 parts by weight of water, and a polyetheramine epoxy resin curing agent D230 (produced by Kunshan Jiulimei Electronic Materials Co., Ltd.), the mass ratio of which to the epoxy resin glue is 1:3.

[0110] (2) The epoxy resin glue is mixed with the curing agent and stirred evenly, and then mixed with the modified magnesium phosphate cement, retarder and water and stirred evenly to obtain the anti-corrosion material.

[0111] Performance test: (1) The anti-corrosion material prepared in this example was coated on the surface of a Q235 steel plate to form an anti-corrosion layer with a thickness of 2 mm. The corrosion resistance of the anti-corrosion layer was tested using a CHI660E electrochemical workstation. The measured corrosion current density was 6.321×10 -7 A.cm -2 (2) The bonding strength of the anti-corrosion material prepared in this embodiment was tested in accordance with GB / T-5210-2006 “Pull-off adhesion test for paints and varnishes”, and the result was 1.891 MPa.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still repair the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any repair, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A modified magnesium phosphate cement anticorrosive material, characterized in that: The raw materials of the anticorrosive material include the following components: 100 parts by weight of modified magnesium phosphate cement, 3 to 15 parts by weight of retarder, 1 to 10 parts by weight of epoxy resin glue, 0.5 to 5 parts by weight of metakaolin, and 15 to 20 parts by weight of water; wherein: The modified magnesium phosphate cement comprises dead-burned magnesium oxide and modified phosphate in a mass ratio of 1-4:1; the raw materials for preparing the modified phosphate comprise nano-alumina, sodium citrate and phosphate in a mass ratio of 0.5-1.5:0.5-1.5:20-25; Also included is a curing agent for the epoxy resin glue, wherein the mass ratio of the curing agent to the epoxy resin glue is 1:3-3.5; It also contains triethanolamine, and the mass ratio of the epoxy resin glue to the triethanolamine is 3-9:0.5-1; before use, the epoxy resin glue and the triethanolamine are mixed evenly, and then the curing agent is added and mixed evenly.

2. The modified magnesium phosphate cement anticorrosive material according to claim 1, characterized in that: The modified phosphate is prepared by the following method: (1) dispersing the nano-alumina in water to form a suspension, then adding the sodium citrate for ultrasonic treatment, and obtaining a modified nano-alumina suspension for standby use; (2) dissolving the phosphate in water, adjusting the pH of the system to a neutral range, and then adding the modified nano-alumina suspension to stir the mixture; after completion, subjecting the obtained reaction solution to a high-speed shear dispersion treatment, and allowing the mixture to stand to obtain a homogeneous slurry for later use; (3) spray drying the homogenized slurry to obtain the modified phosphate.

3. The modified magnesium phosphate cement anticorrosive material according to claim 2, characterized in that: In step (1), the ultrasonic treatment time is 20-35 min, the frequency is 20-30 kHz, and the power is 100-150 W.

4. The modified magnesium phosphate cement anticorrosive material according to claim 2, characterized in that: In step (2), the mass fraction of the solution formed by dissolving the phosphate in water is 20-25%.

5. The modified magnesium phosphate cement anticorrosive material according to claim 2, characterized in that: In step (2), the neutral range of pH=6.5~7.

5.

6. The modified magnesium phosphate cement anticorrosive material according to claim 2, characterized in that: In step (2), ammonia water and citric acid are added to adjust the pH of the system to a neutral range.

7. The modified magnesium phosphate cement anticorrosive material according to claim 2, characterized in that: In step (2), the stirring time is 15 to 25 minutes.

8. The modified magnesium phosphate cement anticorrosive material according to claim 2, characterized in that: In step (2), the rotation speed of the shear dispersion treatment is 3000-7000 rpm, and the treatment time is 8-15 min.

9. The modified magnesium phosphate cement anticorrosive material according to claim 2, characterized in that: In step (2), the standing time is 2 to 3 hours.

10. The modified magnesium phosphate cement anticorrosive material according to claim 2, characterized in that: It also contains a dye, and the mass ratio of the epoxy resin glue to the dye is 3-9:0.5-1.

11. The modified magnesium phosphate cement anticorrosive material according to claim 10, characterized in that: The coloring agent includes at least one of iron oxide green, iron oxide black, iron oxide red, iron oxide blue, and rutile titanium dioxide.

12. The modified magnesium phosphate cement anticorrosive material according to claim 1, characterized in that: The retarder includes at least one of borax, boric acid and zinc sulfate.

13. The modified magnesium phosphate cement anticorrosive material according to claim 1, characterized in that: The phosphate includes at least one of ammonium dihydrogen phosphate and potassium dihydrogen phosphate.

14. The modified magnesium phosphate cement anticorrosive material according to claim 1, characterized in that: The curing agent includes one or more of polyether amines, aromatic amines, fatty amines, polyamides, and phenolic amines.

15. The method for using the modified magnesium phosphate cement anticorrosive material according to any one of claims 1 to 14, characterized in that: The steps include: (S1) mixing the epoxy resin glue and the curing agent, and then mixing with the modified magnesium phosphate cement, the retarder, the metakaolin and water to obtain a slurry; and preparing slurries containing different dyes in the same manner to obtain slurries of different colors for later use; (S2) Applying one color of the slurry on the surface of the substrate to form a first protective layer after solidification, and then applying another color of the slurry on the first protective layer to form a second protective layer after solidification; and so on until all colors of the slurry are applied, thereby forming a protective layer with a color gradient change on the surface of the substrate.

16. The method for using the modified magnesium phosphate cement anticorrosive material according to claim 15, characterized in that: In step (S2), the greater the color difference between adjacent protective layers, the better.

17. The method for using the modified magnesium phosphate cement anticorrosive material according to claim 15, wherein in step (S2), the thickness of each protective layer is 1-2 mm.

18. Use of the modified magnesium phosphate cement anticorrosive material according to any one of claims 1 to 17 in construction engineering, marine engineering or water conservancy and hydropower engineering.

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