Functional filler and preparation method thereof, deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating and application thereof

Abstract

The present invention provides a functional filler and a preparation method thereof, a deep-sea pressure-resistant and erosion-resistant heavy-duty anti-corrosion coating and application, belonging to the field of coating technology. The functional filler provided by the present invention is made of boron-doped silicon carbide as a raw material; hydroxyl radicals are adsorbed on the surface of the boron-doped silicon carbide, and a modified boron-doped silicon carbide containing Si-O-Si covalent bonds is obtained after a shrinkage reaction with silanol, thereby improving the dispersion performance of the functional filler in epoxy resin; boron-doped silicon carbide is prepared by infiltrating boric acid into silicon carbide using a high-temperature diffusion method; the epoxy resin anti-corrosion coating obtained by combining the functional filler with an epoxy toughening agent and a two-dimensional lamellar filler is applied to the surface of deep-sea marine engineering equipment to obtain a deep-sea pressure-resistant and erosion-resistant heavy-duty anti-corrosion coating, which not only has anti-erosion performance, but also after being immersed in 60MPa static seawater pressure for 60 days, the paint film does not fall off, does not bubble, and does not corrode, and still has a good anti-corrosion and protective effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and in particular relates to a functional filler and a preparation method thereof, a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating and its application. Background Art

[0002] Deep-sea corrosion refers to the corrosion of metals or other materials in deep-sea environments (generally referring to ocean depths exceeding 200 meters) caused by chemical or electrochemical reactions. Deep-sea hydrostatic pressure is extremely high (the pressure increases by approximately 1 atmosphere for every 10 meters of depth). This high pressure accelerates the electrochemical corrosion reaction rate of metals in seawater, particularly hydrogen embrittlement (the penetration of hydrogen atoms into the metal lattice, causing brittle fracture). The high pressure and chloride ions in seawater accelerate the breakdown of the passivation film on the metal surface, making it more susceptible to corrosion. Furthermore, deep-sea factors such as ocean currents and hydrothermal activity can also cause erosion corrosion on metal surfaces. Therefore, marine equipment, deep-sea mining vehicles, and other equipment operating in deep-sea corrosive environments require specialized functional protective coatings to extend their service life.

[0003] Deep-sea anti-corrosion coatings are specialized coatings designed to protect metals and other materials from corrosion in deep-sea environments. They require excellent corrosion resistance, wear resistance, saltwater resistance, and good adhesion. Chinese invention patent CN118931315A discloses a deep-sea pressure-resistant and wear-resistant anti-corrosion coating, its preparation method, and application. The raw materials for the deep-sea pressure-resistant and wear-resistant anti-corrosion coating include sulfonated polyaniline-modified graphite carbon nitride. The sulfonated polyaniline-modified graphite carbon nitride is prepared by uniformly mixing aniline, o-aminobenzenesulfonic acid, and graphite carbon nitride, adding hydrochloric acid solution in an ice bath, stirring, and then adding a catalyst to react to obtain the sulfonated polyaniline-modified graphite carbon nitride. The anti-corrosion coating exhibits salt spray resistance of ≥4000 h, wear resistance of ≤30 mg (GB / T 1768, 1000 g / 500 r), and resistance to deep-sea pressure of 6000 meters for ≥60 days. However, in actual use, it is found that it is still unable to resist the erosion and corrosion caused by ocean currents, hydrothermal activities, etc. in deep-sea environments. Therefore, there is an urgent need to provide an anti-corrosion coating with comprehensive properties such as anti-erosion performance, high adhesion, and corrosion resistance to solve the technical problems existing in the existing technology. Summary of the Invention

[0004] The purpose of the present invention is to provide a functional filler and its preparation method, a deep-sea pressure-resistant and erosion-resistant heavy-duty anti-corrosion coating and its application, so as to improve the comprehensive performance of the deep-sea pressure-resistant coating, such as anti-corrosion and erosion resistance.

[0005] As one of the purposes of the invention, the present invention provides a method for preparing a functional filler, wherein boron-doped silicon carbide is modified by a chemical modification method to obtain modified boron-doped silicon carbide having a large number of Si-O-Si covalent bonds on the surface.

[0006] As a preferred embodiment, the chemical modification method includes: adsorbing hydroxyl radicals on the surface of boron-doped silicon carbide, and then reacting with silanol to obtain the functional filler.

[0007] The functional filler can be used in a matrix material containing epoxy groups (such as epoxy resin) because: the Si-O-Si covalent bond has a low surface energy, while the surface of the epoxy resin has a relatively high surface energy. When the functional filler is added to the epoxy resin, the two come into contact, and the silicon-oxygen bond tends to migrate to the surface of the epoxy resin material to reduce the surface energy of the epoxy resin, thereby improving the interfacial bonding between the two, thereby improving the compatibility of the functional filler and the matrix material.

[0008] As a preferred embodiment, the boron-doped silicon carbide is prepared by a high-temperature diffusion method; boron atoms uniformly penetrate into the interior of the silicon carbide along the surface of the silicon carbide particles, thereby improving the hardness and wear resistance of the silicon carbide.

[0009] Specifically, the high-temperature diffusion method includes: adding silicon carbide powder to a boric acid solution, uniformly adsorbing boric acid on the surface of the silicon carbide powder, and drying and high-temperature sintering to obtain the boron-doped silicon carbide.

[0010] Preferably, the drying-high temperature sintering includes dehydrating the boric acid adsorbed on the surface of the silicon carbide powder to generate B2O3 under vacuum and 120-150°C conditions, and then calcining at 1800-2000°C for 10-15h in an inert gas atmosphere for reaction, and annealing to obtain the boron-doped silicon carbide.

[0011] As a preferred embodiment, the method for preparing the functional filler comprises the following specific steps:

[0012] S11. Providing a first reaction system containing hydroxyl radicals by a Fenton reaction;

[0013] S12. The boron-doped silicon carbide powder is added to the first reaction system, hydroxyl radicals are adsorbed on the surface of the boron-doped silicon carbide, and hydroxylated boron-doped silicon carbide is obtained after vacuum drying;

[0014] S13. The hydroxylated boron-doped silicon carbide undergoes a shrinkage reaction with silanol to obtain modified boron-doped silicon carbide.

[0015] Preferably, in S11, the first reaction system is obtained by mixing a hydrogen peroxide solution and a ferric chloride solution and then stirring the mixture at room temperature.

[0016] Preferably, in S12, the particle size of the silicon carbide powder is 1-2 μm.

[0017] Preferably, the silanol is obtained by hydrolysis of small molecule silane under acidic conditions.

[0018] Preferably, the small molecule silane includes but is not limited to methyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane, or a combination thereof.

[0019] Preferably, the mass ratio of the small molecule silane to the boron-doped silicon carbide powder is 1:1-1.5.

[0020] Preferably, in S13, the particle size of the modified boron-doped silicon carbide is 1-2 μm.

[0021] As a second aspect of the invention, the present invention also provides a functional filler prepared by the above-mentioned preparation method.

[0022] As a third aspect of the invention, the present invention also provides a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, which at least includes the functional filler as described above.

[0023] As a preferred embodiment, the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating comprises at least the functional filler, the two-dimensional lamellar filler, the epoxy toughening agent and the epoxy resin.

[0024] Preferably, the two-dimensional lamellar filler includes but is not limited to one or a combination of graphene, boron nitride, etc.

[0025] Preferably, the mass ratio of the functional filler to the epoxy resin is 1:1-1.5.

[0026] Preferably, the epoxy toughening agent is prepared by a ring-opening reaction of carboxylated styrene-butadiene rubber and phenolic epoxy resin in the presence of a catalyst.

[0027] Preferably, the mass ratio of the epoxy toughening agent to the epoxy resin is 0.1-10:1.

[0028] Preferably, the mass ratio of the two-dimensional lamellar filler to the epoxy resin is 0.1-2.5:1.

[0029] Preferably, the epoxy resin includes but is not limited to one or a combination of epoxy E51 and epoxy E44.

[0030] As a preferred embodiment, the preparation method of the epoxy toughening agent comprises: uniformly mixing carboxylated styrene-butadiene rubber and phenolic epoxy resin, adding a catalyst and a silane coupling agent, stirring and heating the mixture under a nitrogen atmosphere until the solution becomes transparent, and cooling the mixture to obtain the epoxy toughening agent. The epoxy toughening agent is obtained by reacting the carboxylated styrene-butadiene rubber and phenolic epoxy resin, followed by adding the silane coupling agent and reacting the mixture to obtain a cross-linked network structure containing a large number of oxygen-containing active groups on its surface.

[0031] Preferably, the catalyst is zinc octoate.

[0032] Preferably, the silane coupling agent includes but is not limited to any one of KH550, KH560, KH570, KH580, and KH590.

[0033] Preferably, the stirring speed is 300-500 r / min.

[0034] Preferably, the reaction temperature is 130-150° C., and the reaction time is 4-5 h.

[0035] As a preferred embodiment, the epoxy resin anti-corrosion coating includes, by mass: 30 to 50 parts of the epoxy resin, 30 to 45 parts of the functional filler, 5 to 20 parts of the two-dimensional lamellar filler, 5 to 10 parts of the epoxy toughener, 1.5 to 2.5 parts of the auxiliary agent, 5 to 10 parts of the active diluent and 20 to 30 parts of the epoxy curing agent.

[0036] Preferably, the auxiliary agent includes but is not limited to one or a combination of bentonite, dispersant solsperse 20000, leveling agent BYK333, etc.

[0037] Preferably, the reactive diluent is a monoepoxy reactive diluent.

[0038] More preferably, the monoepoxy reactive diluent includes but is not limited to one or a combination of propenyl glycidyl ether, butyl glycidyl ether and phenyl glycidyl ether.

[0039] Preferably, the epoxy curing agent is m-xylylenediamine.

[0040] As a fourth aspect of the invention, the present invention also provides a method for preparing the above-mentioned deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, comprising the following specific steps:

[0041] S21. The epoxy resin is first dissolved in the reactive diluent and stirred to obtain a mixture A;

[0042] S22. Add the modified boron-doped silicon carbide and the two-dimensional lamellar filler to mixture A and stir uniformly at 500-600 rpm for 10-20 min. Then add the epoxy toughening agent and the additives and continue stirring. Grind to a fineness of 40 μm to obtain mixture B.

[0043] S23. Add the epoxy curing agent to the mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, and heavy-duty anti-corrosion coating.

[0044] As the fifth aspect of the invention, the present invention also provides a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, comprising spraying the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating described above on the surface of a metal or carbon steel substrate, and forming a paint film after curing, which is the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating.

[0045] In the present invention, the epoxy toughening agent is used in combination with two-dimensional lamellar fillers such as graphene and boron nitride to achieve a synergistic effect. On the one hand, it can improve the interfacial bonding strength between the two-dimensional lamellar filler and the epoxy resin matrix, and on the other hand, it can improve the dispersion performance of the functional filler in the epoxy resin matrix. The obtained deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating has high density, wear resistance and high adhesion.

[0046] The specific principles include: the surface of the epoxy toughening agent contains a large number of oxygen-containing active groups, and its molecular chain segments can penetrate into the gaps and pores on the surface of boron nitride or the interlayer structure of graphene, increasing the mechanical meshing effect between the two, thereby reducing the interfacial tension between the epoxy resin and the two-dimensional lamellar filler; at the same time, the epoxy resin can better wet the boron nitride particles and / or graphene particles, thereby improving the dispersion performance of the functional filler in the epoxy resin system, and giving full play to the physical barrier effect of the two-dimensional lamellar material graphene / boron nitride and the toughening effect of the epoxy toughening agent.

[0047] Preferably, the thickness of the deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating is 200-220 μm.

[0048] Preferably, the deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating has a pull-out adhesion of ≥20 MPa, a hardness of 3H~4H, and a wear rate of ≤8 mg (500g / 500r).

[0049] The deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating is immersed in 60 MPa static seawater pressure for 60 days, and the water absorption rate is 2.6%.

[0050] As the sixth aspect of the invention, the present invention also provides an application of the deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating as described above in deep-sea marine engineering equipment, steel pipe piles, etc.

[0051] The beneficial technical effects obtained by the present invention are:

[0052] 1. The present invention uses a high-temperature diffusion method to infiltrate boron into silicon carbide, thereby improving the hardness and wear resistance of silicon carbide. The boron-doped silicon carbide is chemically modified with silanols using the Fenton reaction to form Si-O-Si covalent bonds, thereby improving the dispersion of functional fillers in the epoxy resin, further enhancing the density, wear resistance, and adhesion of the entire epoxy coating, while reducing the water absorption rate of the paint film in high-pressure seawater. Furthermore, the Si-O-Si covalent bonds can also produce adsorption effects with hydroxyl groups on the metal surface, further improving the adhesion between the coating and the substrate.

[0053] 2. The present invention obtains an epoxy toughening agent having a cross-linked network structure containing a large number of oxygen-containing active groups on the surface after reacting carboxyl styrene-butadiene rubber and phenolic epoxy resin, and then adding a silane coupling agent; the unreacted epoxy groups in the epoxy toughening agent can undergo a cross-linking reaction with the epoxy curing agent, and the epoxy toughening agent can also be used in combination with two-dimensional lamellar fillers such as graphene and boron nitride to achieve a synergistic effect, which can improve the interfacial bonding strength between the two-dimensional lamellar filler and the epoxy resin matrix on the one hand, and improve the dispersion performance of the two-dimensional lamellar filler in the epoxy resin matrix on the other hand.

[0054] 3. The deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating prepared by the present invention uses an active diluent as a solvent, has no VOC emissions during the curing process, and is environmentally friendly and pollution-free. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 Schematic diagram of the reaction mechanism of modified boron-doped silicon carbide provided in Example 1 of the present invention.

[0056] Figure 2 This is a scanning electron microscope photograph of the modified boron-doped silicon carbide according to Example 1 of the present invention.

[0057] Figure 3 This is a curve showing the change of the low-frequency impedance modulus over time of the deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating of Example 1 of the present invention under a high pressure of 60 MPa. DETAILED DESCRIPTION

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments 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 creative efforts shall fall within the scope of protection of the present invention.

[0059] A deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating comprises, by mass, 30-50 parts of epoxy resin, 30-45 parts of modified boron-doped silicon carbide, 5-20 parts of two-dimensional lamellar filler, 5-10 parts of epoxy toughening agent, 1.5-2.5 parts of auxiliary agent, 5-10 parts of active diluent and 20-30 parts of epoxy curing agent.

[0060] In some specific embodiments, the boron-doped silicon carbide is prepared by a high-temperature diffusion method.

[0061] Specifically, boric acid crystals are first dissolved in 80°C deionized water, silicon carbide powder is added, and the mixture is stirred to allow the boric acid to be evenly adsorbed on the surface of the silicon carbide powder. The boric acid adsorbed on the surface of the silicon carbide is dehydrated to generate B2O3, which is then transferred to a quartz crucible and reacted in a tubular quartz furnace at 1800~2000°C under an argon gas atmosphere for 10~15 hours. After annealing, the B2O3 remaining on the surface of the silicon carbide is cleaned with a hydrofluoric acid solution and dried at 80°C to obtain boron-doped silicon carbide (B / SiC).

[0062] Preferably, the modification of the boron-doped silicon carbide includes a chemical modification method.

[0063] Specifically, the present invention generates hydroxyl radicals through the Fenton reaction and adsorbs them on the surface of boron-doped silicon carbide, and then hydrolyzes them by adding small molecule silane, and then shrinks them with silanol to obtain modified boron-doped silicon carbide containing Si-O-Si covalent bonds.

[0064] In some specific embodiments, B / SiC powder is first weighed and added to a 10% hydrogen peroxide solution by mass, the pH is adjusted to 2.5-3.5 using an organic acid, and then a small amount of ferric chloride solution (3%-5% by mass) is added. The mixture is stirred at room temperature for 12-15 hours, and the hydroxyl radicals (·OH) generated by the Fenton reaction between hydrogen peroxide and iron ions are adsorbed and generated on the surface of the boron-doped silicon carbide. The mixture is washed with deionized water 5 times and dried at room temperature to obtain hydroxylated boron-doped silicon carbide (B / SiC-OH). B / SiC-OH is added to an ethanol solution, small molecular silane and 2wt% acetic acid solution are added, and the hydrolysis reaction is stirred at 200r / min for 5-8 hours. The silanol after hydrolysis reacts with B / SiC-OH for 2-3 hours to obtain a modified boron-doped silicon carbide containing Si-O-Si covalent bonds.

[0065] Furthermore, the epoxy toughening agent is prepared by a ring-opening addition reaction.

[0066] Specifically, the carboxyl styrene-butadiene rubber and phenolic epoxy resin are prepared through a ring-opening addition reaction under the action of a catalyst.

[0067] In some specific embodiments, carboxyl styrene-butadiene rubber and phenolic epoxy resin F10 are first mixed uniformly in a mass ratio of 1:1-1.1, and then a catalyst zinc octoate and a silane coupling agent KH560 are added. The mixture is stirred at 300-500 r / min in a three-necked flask under a nitrogen atmosphere, and the temperature is raised to 130-150° C. The mixture is reacted for 4-5 hours to obtain a transparent solution, and the epoxy toughening agent is obtained by cooling.

[0068] Furthermore, the epoxy curing agent is m-xylylenediamine.

[0069] Furthermore, the silicon carbide particle size is 1-2 μm, the mass ratio of boric acid to silicon carbide is 1:15-20, the mass ratio of hydrogen peroxide solution to B / SiC powder is 1:10-15, and the organic acid is 5 wt% of acetic acid or oxalic acid or a combination thereof.

[0070] Furthermore, the mass ratio of the small molecule silane to 2 wt % acetic acid is 50-100:1.

[0071] Furthermore, the small molecule silane includes but is not limited to a combination of one or more of methyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane, etc.

[0072] Furthermore, the mass ratio of the carboxylated styrene-butadiene rubber to the phenolic epoxy resin F10 is 1:1-1.1.

[0073] Furthermore, the addition amount of the catalyst zinc octoate is 0.5% to 1.0% of the total mass of the carboxylated styrene-butadiene rubber and the phenolic epoxy resin.

[0074] Furthermore, the added amount of the silane coupling agent is 1.0% to 1.5% of the total mass of the carboxylated styrene-butadiene rubber and the phenolic epoxy resin.

[0075] Furthermore, the auxiliary agent includes one or a combination of bentonite, dispersant solsperse 20000, leveling agent BYK333, etc., but is not limited thereto.

[0076] Furthermore, the reactive diluent is a monoepoxy reactive diluent, including one or a combination of propenyl glycidyl ether, butyl glycidyl ether and phenyl glycidyl ether, but not limited thereto.

[0077] Furthermore, the two-dimensional lamellar filler includes one or a combination of graphene, boron nitride, etc., but is not limited thereto.

[0078] Furthermore, the epoxy resin includes one or a combination of epoxy E51 and epoxy E44, but is not limited thereto.

[0079] Furthermore, the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating is prepared according to the following steps:

[0080] 1) Dissolve the epoxy resin in the reactive diluent and stir evenly to obtain a mixture A;

[0081] 2) Add modified boron-doped silicon carbide and two-dimensional lamellar filler to mixture A and stir evenly at 500-600 rpm for 10-20 min. Then add epoxy toughening agent and additives, continue stirring, and grind to a fineness of 40 μm to obtain mixture B.

[0082] 3) Add the epoxy curing agent to mixture B, stir evenly, and mature for 5 to 8 minutes to obtain the deep-sea pressure-resistant, erosion-resistant, and heavy-duty anti-corrosion coating.

[0083] Furthermore, the present invention also provides the application of the above-mentioned deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating, which is sprayed on the surface of substrates such as deep-sea marine engineering equipment and / or steel pipe piles to form a coating, thereby achieving long-term pressure-resistant and anti-corrosion protection for marine engineering equipment and steel pipe piles in a deep-sea environment.

[0084] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0085] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the field or according to the product instructions.

[0086] Example 1

[0087] This embodiment provides a method for preparing a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, the specific steps of which include:

[0088] 1. Preparation of Boron-doped Silicon Carbide

[0089] 15g of boric acid crystals were weighed and dissolved in 100g of 80℃ deionized water, and 200g of silicon carbide powder (purchased from Shandong Jinmeng New Materials Co., Ltd., with a particle size of 1~2 μm) was added. The mixture was stirred to allow the boric acid to be evenly adsorbed on the surface of the silicon carbide powder. The boric acid adsorbed on the surface of the silicon carbide was dehydrated and dried at 120℃ in a vacuum to generate B2O3. The mixture was transferred to a quartz crucible and reacted in a tubular quartz furnace at 2000℃ under an argon gas atmosphere for 12h. After annealing, the B2O3 remaining on the surface of the silicon carbide was cleaned with a hydrofluoric acid solution and dried at 80℃ to obtain boron-doped silicon carbide (B / SiC).

[0090] 2. Chemical modification of boron-doped silicon carbide (B / SiC)

[0091] First, weigh 100g of B / SiC powder prepared in step 1 and add it to 100g of 10% hydrogen peroxide solution. Use acetic acid to adjust the pH of the solution to 3.0, then add 0.5g of 3.5wt% ferric chloride solution, and stir at room temperature for 12h. The hydrogen peroxide reacts with iron ions to produce hydroxyl radicals (·OH). The principle of the Fenton reaction is as follows:

[0092]

[0093] The hydroxylated boron-doped silicon carbide (B / SiC-OH) was obtained by adsorbing the hydroxylated free radical ·OH produced by the Fenton reaction onto the surface of the boron-doped silicon carbide. The product was washed five times with deionized water and dried at room temperature. B / SiC-OH was added to an ethanol solution, along with 100g of phenyltriethoxysilane and 10g of 2wt% acetic acid. The mixture was stirred at 200 rpm for 5 hours to hydrolyze the solution to produce phenylsilanol. The hydrolysis reaction mechanism is as follows:

[0094]

[0095] The phenylsilanol after hydrolysis reacts with B / SiC-OH to obtain modified boron-doped silicon carbide containing Si-O-Si covalent bonds. The shrinkage reaction diagram is shown in Figure 1 .

[0096] See also Figure 2 , which is a scanning electron microscope photograph of modified boron-doped silicon carbide. It can be seen from the figure that the particle size of the modified boron-doped silicon carbide is 1~2 μm, and the boron-doped silicon carbide particles are evenly dispersed without obvious agglomeration.

[0097] 3. Preparation of epoxy toughening agent

[0098] Weigh 100g of carboxylated styrene-butadiene rubber and 100g of phenolic epoxy resin F10 and mix them evenly. Add 1g of catalyst zinc octoate and 1g of silane coupling agent KH560. Stir at 500r / min for 30min in a three-necked flask under nitrogen atmosphere, raise the temperature to 130℃, react for 5h to obtain a transparent solution, and cool to obtain the epoxy toughening agent.

[0099] 4. Preparation of deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coatings

[0100] (1) Dissolve 40 g of epoxy resin E 51 (purchased from Nan Ya Epoxy Resin Kunshan Co., Ltd.) in 10 g of active diluent allyl glycidyl ether and stir evenly to obtain mixture A;

[0101] (2) Add 30 g of modified boron-doped silicon carbide, 0.5 g of graphene powder and 7.5 g of boron nitride powder to mixture A, stir at 600 r / min for 20 min, then add 10 g of the epoxy toughening agent prepared in step 3, 0.5 g of bentonite, 1.0 g of dispersant solsperse 20000 and 0.5 g of leveling agent BYK333 in sequence, continue stirring, and grind to a fineness of 40 μm to obtain mixture B;

[0102] (3) Add 20g of epoxy curing agent m-phenylenediamine to mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating.

[0103] Performance characterization:

[0104] The coating prepared in Example 1 was sprayed onto a carbon steel plate (350×250×3 mm in size, sandblasted to Sa2.5) using compressed air and cured at room temperature at 25°C for 24 hours. The antifouling film thickness was controlled to be 220±2 μm to obtain a coating test plate. The coating test plate was immersed in 60 MPa static seawater pressure for 60 days. After being removed from the plate at different times, the coating / carbon steel system was subjected to AC impedance spectroscopy testing using an electrochemical workstation. The test results are shown in [1]. Figure 3 As can be seen from the figure, with the extension of high-pressure immersion time, the low-frequency impedance modulus of the coating / carbon steel system gradually decreases. After 60 days of high-pressure immersion, its low-frequency impedance modulus |Z| 0.01Hz =5.86×10 8 ; This shows that the coating still has excellent protective effect on carbon steel after serving in 60MPa static seawater for 60 days.

[0105] The pull-off adhesion test of the coating on the carbon steel plate, the test method and test standard refer to GB / T 5210, and the pull-off adhesion reaches 23.72MPa.

[0106] The test results of various paint film properties of the coating prepared in this example are shown in Table 1.

[0107] Example 2

[0108] The preparation method of the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating provided in this embodiment is substantially the same as the preparation method in Example 1, with the only difference being that in step 4-(2), the amount of modified boron-doped silicon carbide added is different. Specifically, the preparation method of the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating comprises:

[0109] (1) Dissolve 40 g of epoxy resin E 51 (purchased from Nan Ya Epoxy Resin Kunshan Co., Ltd.) in 10 g of active diluent allyl glycidyl ether and stir evenly to obtain mixture A;

[0110] (2) Add 10 g of modified boron-doped silicon carbide, 20 g of talc, 0.5 g of graphene powder and 7.5 g of boron nitride powder to mixture A, stir at 600 r / min for 20 min, then add 10 g of the epoxy toughening agent prepared in step 3 of Example 1, 0.5 g of bentonite, 1.0 g of dispersant solsperse 20000 and 0.5 g of leveling agent BYK333 in sequence, continue stirring, and grind to a fineness of 40 μm to obtain mixture B;

[0111] (3) Add 20g of epoxy curing agent m-phenylenediamine to mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating.

[0112] The test results of various paint film properties of the coating prepared in this example are shown in Table 1.

[0113] Example 3

[0114] The preparation method of the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating provided in this embodiment is basically the same as the preparation method in Example 1, with the only difference being that in step 4-(2), the amount of modified boron-doped silicon carbide added is different.

[0115] Specifically, the preparation method of the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating includes:

[0116] (1) Dissolve 40 g of epoxy resin E 51 (purchased from Nan Ya Epoxy Resin Kunshan Co., Ltd.) in 10 g of active diluent allyl glycidyl ether and stir evenly to obtain mixture A;

[0117] (2) Add 10 g of modified boron-doped silicon carbide, 8 g of talc, 0.5 g of graphene powder and 19.5 g of boron nitride powder to mixture A, stir at 600 r / min for 20 min, then add 10 g of the epoxy toughening agent prepared in step 3, 0.5 g of bentonite, 1.0 g of dispersant solsperse 20000 and 0.5 g of leveling agent BYK333 in sequence, continue stirring, and grind to a fineness of 40 μm to obtain mixture B;

[0118] (3) Add 20g of epoxy curing agent m-phenylenediamine to mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating.

[0119] The test results of various paint film properties of the coating prepared in this example are shown in Table 1.

[0120] Example 4

[0121] The preparation method of the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating provided in this embodiment is substantially the same as the preparation method in Example 1, with the only difference being that, in step 4-(2), the amount of modified boron-doped silicon carbide added is different. Specifically, the preparation method of the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating comprises:

[0122] (1) Dissolve 40 g of epoxy resin E 51 (purchased from Nan Ya Epoxy Resin Kunshan Co., Ltd.) in 10 g of active diluent allyl glycidyl ether and stir evenly to obtain mixture A;

[0123] (2) Add 5 g of modified boron-doped silicon carbide, 13 g of talc, 0.5 g of graphene powder and 19.5 g of boron nitride powder to mixture A, stir at 600 r / min for 20 min, then add 10 g of the epoxy toughening agent prepared in step 3, 0.5 g of bentonite, 1.0 g of dispersant solsperse 20000 and 0.5 g of leveling agent BYK333 in sequence, continue stirring, and grind to a fineness of 40 μm to obtain mixture B;

[0124] (3) Add 20g of epoxy curing agent m-phenylenediamine to mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating.

[0125] The test results of various paint film properties of the coating prepared in this example are shown in Table 1.

[0126] Comparative Example 1

[0127] This comparative example provides a method for preparing a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, which is basically the same as the preparation method in Example 1, except that in step 4-(2), the functional filler added is commercially available silicon carbide powder (purchased from Shandong Jinmeng New Materials Co., Ltd., with a particle size of 1~2 μm).

[0128] The test results of various paint film properties of the coating prepared in this comparative example are shown in Table 1.

[0129] Comparative Example 2

[0130] This comparative example provides a method for preparing a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, which is basically the same as the preparation method of Example 1, with the only difference being that in step 4-(2), the functional filler added is the boron-doped silicon carbide prepared in step 1, rather than the modified boron-doped silicon carbide, and the addition amount is the same, and the other steps are also the same.

[0131] The test results of various paint film properties of the coating prepared in this comparative example are shown in Table 1.

[0132] Comparative Example 3

[0133] This comparative example provides a preparation method of a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, which is substantially the same as the preparation method of Example 1, except that no epoxy toughening agent is added in step 4-(2). Specifically, the preparation method includes:

[0134] (1) Dissolve 40 g of epoxy resin E 51 (purchased from Nan Ya Epoxy Resin Kunshan Co., Ltd.) in 10 g of active diluent allyl glycidyl ether and stir evenly to obtain mixture A;

[0135] (2) Add 30 g of modified boron-doped silicon carbide, 0.5 g of graphene powder and 7.5 g of boron nitride powder to mixture A, stir at 600 r / min for 20 min, then add 10 g of talc, 0.5 g of bentonite, 1.0 g of dispersant solsperse 20000 and 0.5 g of leveling agent BYK 333 in sequence, continue stirring, and grind to a fineness of 40 μm to obtain mixture B;

[0136] (3) Add 20g of epoxy curing agent m-phenylenediamine to mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating.

[0137] The test results of various paint film properties of the coating prepared in this comparative example are shown in Table 1.

[0138] Comparative Example 4

[0139] This comparative example provides a method for preparing a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, which is substantially the same as the preparation method in Example 1, except that, in step 4-(2), modified boron-doped silicon carbide is not added. Specifically, the method comprises:

[0140] (1) Dissolve 40 g of epoxy resin E 51 (purchased from Nan Ya Epoxy Resin Kunshan Co., Ltd.) in 10 g of active diluent allyl glycidyl ether and stir evenly to obtain mixture A;

[0141] (2) Add 30 g of talc, 0.5 g of graphene powder and 7.5 g of boron nitride powder to mixture A, stir at 600 r / min for 20 min, then add 10 g of talc, 0.5 g of bentonite, 1.0 g of dispersant solsperse 20000 and 0.5 g of leveling agent BYK333 in sequence, continue stirring, and grind to a fineness of 40 μm to obtain mixture B;

[0142] (3) Add 20g of epoxy curing agent m-phenylenediamine to mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating.

[0143] The test results of various paint film properties of the coating prepared in this comparative example are shown in Table 1.

[0144] Comparative Example 5

[0145] This comparative example provides a preparation method of a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, which is substantially the same as the preparation method of Example 1, except that, in step 4-(2), no two-dimensional sheet material is added. Specifically, the method comprises:

[0146] (1) Dissolve 40 g of epoxy resin E 51 (purchased from Nan Ya Epoxy Resin Kunshan Co., Ltd.) in 10 g of active diluent allyl glycidyl ether and stir evenly to obtain mixture A;

[0147] (2) Add 30 g of modified boron-doped silicon carbide and 8 g of talc to mixture A, stir at 600 r / min for 20 min, then add 10 g of the epoxy toughening agent prepared in step 3, 0.5 g of bentonite, 1.0 g of dispersant solsperse 20000, and 0.5 g of leveling agent BYK333 in sequence, continue stirring, and grind to a fineness of 40 μm to obtain mixture B;

[0148] (3) Add 20g of epoxy curing agent m-phenylenediamine to mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating.

[0149] The physical property test results of each embodiment and comparative example are shown in Table 1, where the water absorption rate refers to the water absorption rate after immersion in 60 MPa seawater for 60 days.

[0150] Table 1 Comprehensive physical properties of the coatings provided in the examples and comparative examples after coating on the steel claws

[0151]

[0152] As can be seen from Table 1, the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating prepared in Example 1 has a water absorption rate of only 2.32% after immersion in 60 MPa seawater for 60 days, a wear rate of 8.5 mg, and a pull-out adhesion of the coating of up to 23.72 MPa, indicating that the coating provided by this patent has good pressure resistance, wear resistance and adhesion.

[0153] By comparing the test results of various examples, it is shown that as the content of modified boron-doped silicon carbide in the formula increases, the wear resistance and adhesion of the paint film become stronger, and the hardness and water resistance of the paint film also increase.

[0154] By comparing the test results of Example 1 and Comparative Example 1, it is shown that the addition of modified boron-doped silicon carbide can improve the salt water resistance, hardness and pull-out adhesion of the paint film, and the wear resistance and water absorption properties of the paint film are also greatly improved.

[0155] By comparing the test results of Example 1 and Comparative Example 2, it is shown that after the boron-doped silicon carbide is modified by phenylsilanol, the wear resistance and pull-off adhesion are significantly improved, the modified boron-doped silicon carbide has better dispersion performance in epoxy resin, the density of the paint film is improved, and the water absorption rate of the paint film in high-pressure seawater is reduced.

[0156] By comparing the test results of Example 1 and Comparative Example 3, it is shown that adding an epoxy toughening agent can improve the wear resistance and pull-off adhesion of the paint film.

[0157] By comparing the test results of Example 1, Comparative Example 3 and Comparative Example 4, boron-doped silicon carbide can increase the hardness of the paint film, and at the same time, the modified boron-doped silicon carbide can improve the dispersibility of the wear-resistant filler boron-doped silicon carbide in the epoxy resin, thereby improving the density and water resistance of the paint film, and the water absorption rate in high-pressure seawater is lower; on the other hand, it is explained that the simultaneous addition of epoxy toughening agent and modified boron-doped silicon carbide to the coating has a synergistic enhancement function; the epoxy toughening agent can form an "island structure" in the paint film, thereby improving the wear resistance of the paint film.

[0158] By comparing the test results of Example 1, Comparative Example 3, and Comparative Example 5, it is shown that the epoxy toughening agent and the two-dimensional lamellar filler (graphene and / or boron nitride) have a synergistic effect. On the one hand, it can improve the interfacial bonding strength between the two-dimensional lamellar filler and the epoxy resin matrix, and on the other hand, it can improve the dispersion performance of the functional filler in the epoxy resin matrix. Specifically, the surface of the epoxy toughening agent contains a large number of oxygen-containing active groups. First, the epoxy toughening agent contains epoxy groups (derived from the epoxy groups in the novolac epoxy resin that do not participate in the ring-opening reaction) that undergo a cross-linking reaction with the epoxy curing agent. At the same time, its molecular chain segments can penetrate into the gaps and pores on the surface of the boron nitride or the interlayer structure of the graphene, increasing the mechanical engagement between the two, thereby reducing the interfacial tension between the epoxy resin and the two-dimensional lamellar filler. At the same time, the epoxy resin can better wet the boron nitride particles and / or graphene particles, thereby improving the dispersion performance of the functional filler in the epoxy resin system, giving full play to the barrier effect of boron nitride (reduced water absorption) and the toughening effect of the epoxy toughening agent.

[0159] In summary, the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating prepared using the technical solution of the present invention not only has a high-strength corrosion resistance, but also has excellent anti-erosion performance, corrosion resistance and other properties. Obviously, the epoxy resin anti-corrosion coating provided by the present invention is a coating product with excellent comprehensive performance, which can be used in deep-sea marine engineering equipment, steel pipe piles, etc.

[0160] The above embodiments are described to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing a functional filler, characterized in that: The method comprises adopting a chemical modification method to modify boron-doped silicon carbide to obtain modified boron-doped silicon carbide having Si-O-Si covalent bonds on the surface; The chemical modification method includes: adsorbing hydroxyl radicals on the surface of boron-doped silicon carbide, and then reacting with silanol to form the functional filler; The boron-doped silicon carbide is prepared by a high-temperature diffusion method; The high-temperature diffusion method comprises: adding silicon carbide powder to a boric acid solution, uniformly adsorbing boric acid on the surface of the silicon carbide powder particles, and drying and high-temperature sintering to obtain the boron-doped silicon carbide; The drying-high temperature sintering includes dehydrating the boric acid adsorbed on the surface of the silicon carbide powder to generate B2O3 under vacuum and 120-150°C conditions, and then calcining at 1800-2000°C for 10-15h in an inert gas atmosphere for reaction, and annealing to obtain the boron-doped silicon carbide.

2. The method for preparing the functional filler according to any one of claim 1, characterized in that: The specific steps include: S11. Providing a first reaction system containing hydroxyl radicals by a Fenton reaction; S12. The boron-doped silicon carbide powder is added to the first reaction system, hydroxyl radicals are adsorbed on the surface of the boron-doped silicon carbide, and hydroxylated boron-doped silicon carbide is obtained after vacuum drying; S13. The hydroxylated boron-doped silicon carbide undergoes a shrinkage reaction with silanol to obtain modified boron-doped silicon carbide.

3. The method for preparing the functional filler according to claim 2, characterized in that: In S11, the first reaction system is obtained by mixing a hydrogen peroxide solution and a ferric chloride solution and stirring at room temperature; And / or, in S12, the silanol is obtained by hydrolysis of a small molecule silane under acidic conditions; And / or, the small molecule silane is one or a combination of methyltriethoxysilane, phenyltriethoxysilane, and vinyltriethoxysilane; And / or, the mass ratio of the small molecule silane to the boron-doped silicon carbide is 1:1-1.5; And / or, in S13, the particle size of the modified boron-doped silicon carbide is 1-2 μm.

4. A functional filler prepared by the preparation method according to any one of claims 1 to 3.

5. A deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, characterized in that: At least comprising the functional filler prepared by the preparation method according to any one of claims 1 to 3, or the functional filler according to claim 4.

6. The deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to claim 5, characterized in that: At least comprising the functional filler, two-dimensional lamellar filler, epoxy toughening agent and epoxy resin; And / or, the two-dimensional lamellar filler comprises one or a combination of graphene and boron nitride; And / or, the mass ratio of the functional filler to the epoxy resin is 1:1-1.5; And / or, the epoxy toughening agent is prepared by a ring-opening reaction of carboxylated styrene-butadiene rubber and phenolic epoxy resin in the presence of a catalyst; And / or, the mass ratio of the epoxy toughening agent to the epoxy resin is 0.1-10:1; and / or, the mass ratio of the two-dimensional lamellar filler to the epoxy resin is 0.1 to 2.5:1; And / or, the epoxy resin is one or a combination of epoxy E51 and epoxy E44.

7. The deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to claim 6, characterized in that: The preparation method of the epoxy toughening agent comprises: uniformly mixing carboxyl styrene-butadiene rubber and phenolic epoxy resin, adding a catalyst and a silane coupling agent, stirring and heating under a nitrogen atmosphere to react until the solution is transparent, and cooling to obtain the epoxy toughening agent.

8. The deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to claim 7, characterized in that: The catalyst is zinc octoate; And / or, the silane coupling agent is any one of KH550, KH560, KH570, KH580, and KH590; And / or, the stirring speed is 300-500 r / min; And / or, the reaction temperature is 130-150° C., and the reaction time is 4-5 h.

9. The deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to any one of claims 5 to 8, characterized in that: In parts by mass, the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating comprises: 30-50 parts of the epoxy resin, 30-45 parts of the functional filler, 5-20 parts of the two-dimensional lamellar filler, 5-10 parts of the epoxy toughening agent, 1.5-2.5 parts of the auxiliary agent, 5-10 parts of the active diluent and 20-30 parts of the epoxy curing agent.

10. The deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to claim 9, characterized in that: The auxiliary agent is one or a combination of bentonite, dispersant solsperse 20000, and leveling agent BYK333; And / or, the reactive diluent is a monoepoxy reactive diluent; And / or, the monoepoxy reactive diluent includes one or a combination of propenyl glycidyl ether, butyl glycidyl ether and phenyl glycidyl ether; The epoxy curing agent is m-xylylenediamine.

11. A method for preparing the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to any one of claims 5 to 10, characterized in that: The specific steps include: S21. The epoxy resin is first dissolved in the reactive diluent and stirred to obtain a mixture A; S22. Add the modified boron-doped silicon carbide and the two-dimensional lamellar filler to the mixture A and stir evenly, stir at 500~600r / min for 10~20min, then add the epoxy toughening agent and additives, continue stirring, and grind to a fineness of 40 μm to obtain a mixture B; S23. Add the epoxy curing agent to the mixture B, stir evenly, and mature for 5 to 8 minutes to obtain a deep-sea pressure-resistant, erosion-resistant, and heavy-duty anti-corrosion coating.

12. A deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating, comprising spraying the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to any one of claims 5 to 10 onto the surface of a metal or carbon steel substrate, and curing the coating to form a paint film, which is the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating; And / or, the thickness of the deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating is 200-220 μm; And / or, pull-off adhesion ≥ 20 MPa, hardness 3H~4H, wear rate ≤ 8 mg (500 g / 500 r); And / or, the deep-sea pressure-resistant, erosion-resistant and heavy-duty anti-corrosion coating has a water absorption rate of ≤2.6% after being immersed in a static seawater pressure of 60 MPa for 60 days.

13. A deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to any one of claims 5 to 10, or use of the deep-sea pressure-resistant, erosion-resistant, heavy-duty anti-corrosion coating according to claim 12 in deep-sea marine equipment and steel pipe piles.

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