Marine anticorrosive paint and preparation method thereof

Abstract

The invention provides a marine anticorrosive coating and a preparation method thereof, and belongs to the technical field of marine anticorrosive coatings. The anti-corrosion effect of the anti-corrosion coating is improved through irradiation modified polytetrafluoroethylene; by modifying graphene oxide with a polyphenol compound loaded with copper oxide, copper oxide can be uniformly distributed in an anti-corrosion coating, and the antibacterial effect is improved; lithium ions dissociated from the lithium-containing phosphate can be used as a cathode inhibitor, so that metal reacts with oxygen, water and the like in the environment, and a passivation layer is formed to improve the corrosion resistance; the layered two-dimensional filler can form a barrier effect in the coating, and can construct a ternary synergistic anti-corrosion effect with the modified graphene and the nano cellulose, so that the corrosion resistance of the anti-corrosion coating is improved; the nano cellulose has good interfacial compatibility with the epoxy resin and the modified graphene, the flexibility of the coating can be improved, the impact resistance is improved, and the problem that the epoxy resin is prone to cracking due to large brittleness is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of marine anti-corrosion coatings, and particularly relates to a marine anti-corrosion coating and a preparation method thereof. Background Art

[0002] The marine environment has great corrosive destructiveness to coastal facilities. At present, the main method for marine engineering protection is to coat marine anti-corrosion coatings that prevent seawater corrosion. Marine anti-corrosion coatings are generally divided into primer, intermediate paint and topcoat. The main function of the primer is rust prevention and enhancement of the adhesion between the coating and the metal surface. Common ones include organic zinc-rich coatings and inorganic zinc-rich coatings, etc.; the intermediate paint has good compatibility with the primer, and its main function is to increase the film thickness and enhance the paint layer body, with good water resistance, weather resistance and chemical solvent resistance; the functions of the topcoat mainly include decoration, weather resistance, anti-aging and anti-corrosion, etc.

[0003] At present, the intermediate paints and topcoats that are more widely used mainly include epoxy coatings, polyurethane coatings, chlorinated rubber coatings, fluorocarbon resins and polysiloxane coatings, etc. Among them, epoxy coatings have good adhesion and performance in resisting corrosive media such as acids, alkalis, salts and solvents, and can enable the formed anti-corrosion coating to effectively resist the erosion of seawater and the corrosion of salt spray. However, the epoxy coating has poor flexibility and is prone to cracking when subjected to impact or deformation, and microcracks will cause very serious local corrosion in the marine environment containing chloride ions, resulting in the peeling off of the anti-corrosion coating. In addition, sulfate-reducing bacteria and saprophytic bacteria in the marine environment adhere to the surface of the coating, causing bacterial corrosion and resulting in a decline in the anti-corrosion performance of the anti-corrosion coating.

[0004] Therefore, there is an urgent need to provide a marine anti-corrosion coating with good impact resistance and anti-corrosion performance. Summary of the Invention

[0005] The purpose of the present invention is to provide a marine anti-corrosion coating with good impact resistance and anti-corrosion performance and a preparation method thereof.

[0006] In order to achieve the above invention purpose, the present invention provides the following technical solutions: The present invention provides a marine anti-corrosion coating, which comprises the following components in parts by weight: 25-75 parts of epoxy resin, 15-30 parts of irradiated modified polytetrafluoroethylene, 5-10 parts of modified graphene, 2-10 parts of lithium-containing phosphate, 2-10 parts of layered two-dimensional filler, 1-5 parts of cation-modified nanocellulose, 0.1-1 part of leveling agent, 10-20 parts of curing agent and 200-500 parts of diluent; The modified graphene is polyphenol compound-modified graphene oxide loaded with copper oxide.

[0007] Preferably, the epoxy resin is bisphenol A type epoxy resin.

[0008] Preferably, the preparation method of the copper oxide-loaded polyphenol compound-modified graphene oxide includes: (1) Mix a polyphenol compound, graphene oxide, and water, and then carry out a reduction reaction to obtain polyphenol-modified graphene oxide; (2) Mix the polyphenol-modified graphene oxide obtained in step (1) with a soluble copper salt and a solvent to obtain a suspension. Adjust the pH value of the suspension to 6-8, and then carry out a reaction and aging in sequence to obtain the copper oxide-loaded polyphenol compound-modified graphene oxide.

[0009] Preferably, the polyphenol compound in step (1) includes one or more of quercetin, anthocyanin, and catechin.

[0010] Preferably, the mass ratio of the polyphenol compound to graphene oxide in step (1) is 1-10:1.

[0011] Preferably, the temperature of the reaction in step (2) is 85-90 °C; the reaction time is 30-60 min.

[0012] Preferably, the lithium-containing phosphate includes one or both of lithium iron phosphate and lithium manganese phosphate.

[0013] Preferably, the layered two-dimensional filler includes one or more of tungsten disulfide, graphite, and talcum powder.

[0014] Preferably, the nanocellulose in the cation-modified nanocellulose includes one or more of cellulose nanofibers, cellulose nanocrystals, and bacterial nanocellulose.

[0015] The present invention also provides a preparation method of the marine anti-corrosion coating described in the above technical solution, including: mixing an epoxy resin, irradiated modified polytetrafluoroethylene, modified graphene, lithium-containing phosphate, layered two-dimensional filler, cation-modified nanocellulose, leveling agent, curing agent, and diluent to obtain a marine anti-corrosion coating.

[0016] The present invention provides a marine anti-corrosion coating, which comprises the following components by weight: 25-75 parts of epoxy resin, 15-30 parts of irradiated modified polytetrafluoroethylene, 5-10 parts of modified graphene, 2-10 parts of lithium-containing phosphate, 2-10 parts of layered two-dimensional filler, 1-5 parts of cation-modified nanocellulose, 0.1-1 part of leveling agent, 10-20 parts of curing agent and 200-500 parts of diluent; the modified graphene is polyphenol compound-modified graphene oxide loaded with copper oxide. In the marine anti-corrosion coating provided by the present invention, irradiated modified polytetrafluoroethylene is included, and the irradiated modified polytetrafluoroethylene has a good interfacial bonding effect with the epoxy resin; moreover, the irradiated modified polytetrafluoroethylene can reduce the adhesion of bacteria and microorganisms, reduce the bacterial corrosion effect, and improve the anti-corrosion effect of the anti-corrosion coating; in the marine anti-corrosion coating provided by the present invention, polyphenol compound-modified graphene oxide loaded with copper oxide is included, and the polyphenol compound-modified graphene oxide can improve the dispersion of graphene in the anti-corrosion coating; moreover, by loading copper oxide on the polyphenol compound-modified graphene oxide, the copper oxide can be uniformly distributed in the anti-corrosion coating, improve the antibacterial effect, reduce the bacterial corrosion effect, and improve the anti-corrosion effect of the anti-corrosion coating; in the marine anti-corrosion coating provided by the present invention, lithium-containing phosphate is included, and the dissociated lithium ions can react with oxygen, water, etc. in the environment to form a passivation layer to improve the anti-corrosion property; in the marine anti-corrosion coating provided by the present invention, a layered two-dimensional filler is included, and the layered two-dimensional structure forms a barrier effect in the anti-corrosion coating, and can also build a ternary synergistic anti-corrosion effect with the modified graphene and the cation-modified nanocellulose to enhance the corrosion resistance of the anti-corrosion coating; in the marine anti-corrosion coating provided by the present invention, cation-modified nanocellulose is added, and the cation-modified nanocellulose has rich functional groups and has good interfacial compatibility with the epoxy resin and the modified graphene, improves the flexibility of the coating, and enhances the impact resistance of the anti-corrosion coating, solving the problem of easy cracking caused by the large brittleness of the epoxy resin. The results of the examples show that the anti-corrosion coating formed by the marine anti-corrosion coating provided by the present invention not only has excellent impact resistance, but also has excellent anti-corrosion effect. Detailed Embodiments

[0017] The present invention provides a marine anti-corrosion coating, which comprises the following components by weight: 25-75 parts of epoxy resin, 15-30 parts of irradiated modified polytetrafluoroethylene, 5-10 parts of modified graphene, 2-10 parts of lithium-containing phosphate, 2-10 parts of layered two-dimensional filler, 1-5 parts of cation-modified nanocellulose, 0.1-1 part of leveling agent, 10-20 parts of curing agent and 200-500 parts of diluent; The modified graphene is polyphenol compound-modified graphene oxide loaded with copper oxide.

[0018] In the present invention, unless otherwise specified, the raw materials used in the present invention are all commercially available products in the art.

[0019] By weight parts, the marine anti-corrosion coating provided by the present invention comprises 25 to 75 parts of epoxy resin. As an embodiment of the present invention, the weight parts of the epoxy resin can be 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts or 75 parts. In the present invention, the epoxy resin is preferably bisphenol A type epoxy resin. In the embodiments of the present invention, the epoxy resin can be E51. The present invention uses epoxy resin as the film-forming substance of the marine anti-corrosion coating.

[0020] Based on 25 to 75 parts by weight of the epoxy resin, the marine anti-corrosion coating provided by the present invention comprises 15 to 30 parts of irradiated modified polytetrafluoroethylene. As an embodiment of the present invention, the weight parts of the irradiated modified polytetrafluoroethylene can be 15 parts, 20 parts, 25 parts or 30 parts. In the embodiments of the present invention, the particle size of the irradiated modified polytetrafluoroethylene is preferably 500 nm; the model of the irradiated modified polytetrafluoroethylene is preferably TF-9207, and the source is preferably Dongguan Taotao Plastic Raw Material Co., Ltd. The present invention adopts the above-mentioned irradiated modified polytetrafluoroethylene nanopowder, which has good dispersibility and good compatibility with epoxy resin.

[0021] The present invention has no special limitation on the preparation method of the irradiated modified polytetrafluoroethylene, and any conventional method for preparing irradiated modified polytetrafluoroethylene can be adopted. In the present invention, the preparation method of the irradiated modified polytetrafluoroethylene preferably comprises: subjecting polytetrafluoroethylene to electron beam irradiation to obtain irradiated modified polytetrafluoroethylene.

[0022] In the embodiments of the present invention, the model of the polytetrafluoroethylene is preferably TF-9207; the particle size of the polytetrafluoroethylene is preferably 500 nm.

[0023] In the present invention, the irradiation dose of the electron beam irradiation is preferably 50 to 200 kGy. As an embodiment of the present invention, the irradiation dose of the electron beam irradiation can be 50 kGy, 100 kGy, 150 kGy or 200 kGy.

[0024] In the present invention, the irradiation time of the electron beam irradiation is preferably 6 to 12 h. As an embodiment of the present invention, the irradiation time of the electron beam irradiation can be 6 h, 7 h, 8 h, 9 h, 10 h, 11 h or 12 h.

[0025] In the present invention, the beam current energy of the electron beam irradiation is preferably 0.5 to 5 MeV. As an embodiment of the present invention, the beam current energy of the electron beam irradiation can be 0.5 MeV, 1 MeV, 2 MeV, 3 MeV, 4 MeV or 5 MeV.

[0026] Based on 25 to 75 parts by weight of epoxy resin, the marine anti-corrosion coating provided by the present invention includes 5 to 10 parts of modified graphene. As an implementation manner of the present invention, the weight parts of the modified graphene can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts. In the present invention, the modified graphene is polyphenol compound-modified graphene oxide loaded with copper oxide. The polyphenol compound-modified graphene oxide can improve the dispersibility of graphene in the coating; loading copper oxide on the polyphenol compound-modified graphene oxide can make the copper oxide evenly distributed in the anti-corrosion coating, improve the antibacterial effect, reduce the bacterial corrosion effect, and improve the anti-corrosion effect of the anti-corrosion coating.

[0027] In the present invention, the diameter of the copper oxide in the polyphenol compound-modified graphene oxide loaded with copper oxide is preferably 40 to 60 nm, more preferably 40 to 50 nm. When the diameter of the copper oxide in the modified graphene oxide provided by the present invention is within the above range, it has a better bactericidal effect.

[0028] In the present invention, the mass ratio of the copper oxide to the polyphenol-modified graphene oxide in the polyphenol compound-modified graphene oxide loaded with copper oxide is preferably 1 to 8:1. The present invention controls the mass ratio of the two within the above range, which is more conducive to the uniform distribution of the copper oxide in the polyphenol-modified graphene oxide.

[0029] In the present invention, the preparation method of the polyphenol compound-modified graphene oxide loaded with copper oxide preferably includes: (1) Mix the polyphenol compound, graphene oxide and water, and then carry out a reduction reaction to obtain polyphenol-modified graphene oxide; (2) Mix the polyphenol-modified graphene oxide obtained in the step (1) with a soluble copper salt and a solvent to obtain a suspension, adjust the pH value of the suspension to 6 to 8, and then carry out a reaction and aging in sequence to obtain polyphenol compound-modified graphene oxide loaded with copper oxide.

[0030] The present invention preferably mixes the polyphenol compound, graphene oxide and water, and then carries out a reduction reaction to obtain polyphenol-modified graphene oxide.

[0031] In the present invention, the polyphenol compound preferably includes one or more of quercetin, anthocyanin and catechin. The present invention uses the above polyphenol compounds, which have rich functional groups and can improve the dispersibility of graphene oxide in the marine anti-corrosion coating.

[0032] The present invention has no special limitation on the source and size of the graphene oxide, and conventional commercially available graphene oxide or graphene oxide prepared by conventional methods can be used.

[0033] In the present invention, the mass ratio of the polyphenol compound to graphene oxide is preferably 1 to 10:1, more preferably 3 to 6:1. By controlling the dosages of the two within the above range in the present invention, the dispersibility of graphene oxide in the marine anti-corrosion coating can be fully improved.

[0034] In the present invention, the water serves as the dispersion medium. There is no special limitation on the dosage of the water in the present invention, and it can be adjusted according to the dosages of the polyphenol compound and graphene oxide used, as long as it can satisfy the sufficient reaction of the two. In the examples of the present invention, the mass ratio of the polyphenol compound to the volume of water can be (1 to 10) g: 100 mL.

[0035] There is no special limitation on the method of mixing the polyphenol compound, graphene oxide and water in the present invention, as long as the polyphenol compound and graphene oxide can be fully dispersed in water. In the present invention, the method of mixing the polyphenol compound, water and graphene oxide is preferably ultrasonic.

[0036] In the present invention, the temperature of the reduction reaction is preferably 80 to 90 °C, more preferably 85 to 90 °C; the time of the reduction reaction is preferably 2 to 6 h, more preferably 3 to 5 h. In the present invention, through the reduction reaction, the polyphenol modifies the graphene oxide.

[0037] In the present invention, preferably after the reduction reaction, the suspension obtained from the reduction reaction is filtered, washed and dried in sequence to obtain polyphenol-modified graphene oxide. There is no special limitation on the operation methods of the filtration, washing and drying in the present invention, and conventional methods of filtration, washing and drying can be used. In the examples of the present invention, the washing reagent can be deionized water; the drying temperature can be 80 °C, and the drying time can be 24 h.

[0038] After obtaining the polyphenol-modified graphene oxide, in the present invention, preferably the polyphenol-modified graphene oxide, soluble copper salt and solvent are mixed to obtain a suspension, the pH value of the suspension is adjusted to 6 to 8, and then reaction and aging are carried out in sequence to obtain polyphenol compound-modified graphene oxide loaded with copper oxide.

[0039] There is no special limitation on the type of the solvent in the present invention, and any solvent that can fully disperse the polyphenol-modified graphene oxide and dissolve the copper salt can be used. In the examples of the present invention, the solvent can be anhydrous ethanol. In the examples of the present invention, when the mass of the polyphenol-modified graphene oxide is 1 to 10 g, the volume of the solvent can be 50 to 100 mL.

[0040] In the present invention, the soluble copper salt is preferably copper nitrate.

[0041] In the present invention, the mass ratio of the soluble copper salt to the polyphenol-modified graphene oxide is preferably 2-6:1, more preferably 4-5:1. By controlling the amounts of the two within the above range in the present invention, it is more conducive to the uniform distribution of the formed copper oxide in the polyphenol-modified graphene oxide.

[0042] The present invention has no special limitation on the method of mixing the polyphenol-modified graphene oxide, the soluble copper salt and the solvent, as long as the polyphenol-modified graphene oxide can be fully dispersed in the solvent. In the examples of the present invention, the method of mixing the polyphenol-modified graphene oxide, the soluble copper salt and the solvent is preferably ultrasonic.

[0043] In the present invention, the reagent for adjusting the pH value of the suspension is preferably sodium hydroxide solution. In the present invention, the concentration of the sodium hydroxide solution is preferably 0.5-1 mol / L. By adjusting the pH value of the suspension to 6-8 in the present invention, the copper salt can be caused to react to obtain copper oxide.

[0044] In the present invention, the temperature of the reaction is preferably 85-90 °C, more preferably 88-90 °C; the time of the reaction is preferably 30-60 min, more preferably 40-60 min. In the present invention, the reaction is preferably carried out under stirring. By controlling the temperature and time within the above range in the present invention, it is more conducive to promoting the adsorption of copper onto the polyphenol-modified graphene oxide and decomposing into copper oxide after forming a precipitate.

[0045] In the present invention, the aging time is preferably 24-48 h, more preferably 36-48 h. By standing for aging in the present invention, the growth of copper oxide crystals can be promoted.

[0046] The present invention preferably filters, washes and dries the suspension obtained by aging in sequence after aging to obtain polyphenol compound-modified graphene oxide loaded with copper oxide. The present invention has no special limitation on the operating methods of the filtration, washing and drying, and conventional filtration, washing and drying methods can be used. In the examples of the present invention, the washing reagent can be deionized water; the drying temperature can be 60 °C; the drying time can be 48 h.

[0047] Based on 25-75 parts by weight of the epoxy resin, the marine anti-corrosion coating provided by the present invention includes 2-10 parts of lithium-containing phosphate. As an embodiment of the present invention, the weight parts of the lithium-containing phosphate can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts. In the present invention, the lithium-containing phosphate preferably includes one or both of lithium iron phosphate and lithium manganese phosphate. In the present invention, the lithium ions dissociated from the lithium-containing phosphate can react with oxygen, water, etc. in the environment to form a passivation layer to improve the anti-corrosion property.

[0048] Based on the epoxy resin being 25 to 75 parts by weight, the marine anti-corrosion coating provided by the present invention includes 2 to 10 parts of layered two-dimensional filler. As an embodiment of the present invention, the weight parts of the layered two-dimensional filler can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts. The addition of the layered two-dimensional structure in the present invention can form a barrier effect in the coating, and can also build a ternary synergistic anti-corrosion effect with modified graphene and cation-modified nanocellulose, improving the corrosion resistance of the anti-corrosion coating.

[0049] In the present invention, the layered two-dimensional filler preferably includes one or more of tungsten disulfide, graphite and talcum powder, and more preferably tungsten disulfide or graphite. In the present invention, the particle size of the layered two-dimensional filler is preferably 50 to 100 nm, and more preferably 60 to 100 nm.

[0050] Based on the epoxy resin being 25 to 75 parts by weight, the marine anti-corrosion coating provided by the present invention includes 1 to 5 parts of cation-modified nanocellulose. As an embodiment of the present invention, the weight parts of the nanocellulose can be 1 part, 2 parts, 3 parts, 4 parts or 5 parts.

[0051] In the present invention, the nanocellulose in the cation-modified nanocellulose preferably includes one or more of cellulose nanofibers, cellulose nanocrystals and bacterial nanocellulose. The above-mentioned nanocellulose used in the present invention has rich functional groups and good compatibility with epoxy resin. The present invention has no special limitation on the source of the nanocellulose, and conventional commercially available products can be used.

[0052] In the present invention, the cation modifier of the cation-modified nanocellulose is preferably 2,3-epoxypropyltrimethylammonium chloride.

[0053] In the present invention, the preparation method of the cation-modified nanocellulose preferably includes: mixing a nanocellulose suspension, sodium hydroxide and 2,3-epoxypropyltrimethylammonium chloride to obtain a mixed slurry; carrying out a modification reaction on the mixed slurry to obtain cation-modified nanocellulose.

[0054] In the present invention, the mass concentration of the nanocellulose suspension is preferably 1 to 10%, and more preferably 5 to 8%.

[0055] In the present invention, the mass concentration of sodium hydroxide in the mixed slurry is preferably 5 to 15%, and more preferably 10 to 12%.

[0056] In the present invention, the mass concentration of 2,3-epoxypropyltrimethylammonium chloride in the mixed slurry is preferably 5 to 8%, and more preferably 6 to 7%.

[0057] The present invention has no particular limitation on the method of mixing the nanocellulose suspension, sodium hydroxide, and 2,3-epoxypropyltrimethylammonium chloride, as long as the nanocellulose suspension, sodium hydroxide, and 2,3-epoxypropyltrimethylammonium chloride can be mixed evenly to form a uniformly distributed mixed slurry.

[0058] In the present invention, the temperature of the modification reaction is preferably 50 - 140°C, more preferably 120 - 140°C; the time of the modification reaction is preferably 3 - 6 h, more preferably 4 - 5 h.

[0059] The present invention preferably centrifuges, washes, dialyzes, and dries the system obtained from the modification reaction to obtain cation-modified nanocellulose. The present invention has no particular limitation on the operation methods of the centrifugation, washing, dialysis, and drying, as long as the residual impurities in the cation-modified nanocellulose can be sufficiently removed.

[0060] In the present invention, the diameter of the nanocellulose is preferably 30 - 80 nm. As an embodiment of the present invention, the diameter of the nanocellulose can be 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, or 80 nm. In the present invention, the length of the nanocellulose is preferably 1000 - 2000 nm, more preferably 1500 - 2000 nm. The present invention uses nanocellulose of the above dimensions, which is more beneficial to improving the toughness of the anti-corrosion coating.

[0061] Based on 25 - 75 parts by weight of epoxy resin, the marine anti-corrosion coating provided by the present invention includes 0.1 - 1 part of a leveling agent. As an embodiment of the present invention, the weight part of the leveling agent can be 0.1 part, 0.2 part, 0.5 part, 0.6 part, or 1 part. In the present invention, the leveling agent is preferably PV88. The present invention adds a leveling agent to improve the leveling property and uniformity of the marine anti-corrosion coating.

[0062] Based on 25 - 75 parts by weight of epoxy resin, the marine anti-corrosion coating provided by the present invention includes 10 - 20 parts of a curing agent. As an embodiment of the present invention, the weight part of the curing agent can be 10 parts, 12 parts, 15 parts, 16 parts, or 20 parts. In the present invention, the curing agent is preferably cycloaliphatic amine isophorone diamine. The present invention adds a curing agent to promote the curing of epoxy resin.

[0063] Based on 25 - 75 parts by weight of epoxy resin, the marine anti-corrosion coating provided by the present invention includes 200 - 500 parts of a diluent. As an embodiment of the present invention, the weight part of the diluent can be 200 parts, 300 parts, 400 parts, or 500 parts. In the present invention, the diluent is preferably water and / or ethanol.

[0064] The marine anti-corrosion coating provided by the present invention utilizes irradiated modified polytetrafluoroethylene to improve the anti-corrosion effect of the anti-corrosion coating; loading copper oxide on polyphenol compound modified graphene oxide can improve the anti-corrosion effect of the anti-corrosion coating; the lithium ions dissociated from lithium phosphate can react with oxygen, water, etc. in the environment to form a passivation layer to improve anti-corrosion performance; the layered two-dimensional filler can form a ternary synergistic anti-corrosion effect with modified graphene and cation-modified nanocellulose to enhance the corrosion resistance of the anti-corrosion coating; the cation-modified nanocellulose has good interfacial compatibility with epoxy resin and modified graphene, and can also improve the flexibility of the anti-corrosion coating and enhance the impact resistance of the anti-corrosion coating, solving the problem of easy cracking caused by the large brittleness of epoxy resin.

[0065] The present invention also provides a preparation method of the marine anti-corrosion coating described in the above technical solution, including: mixing epoxy resin, irradiated modified polytetrafluoroethylene, modified graphene, lithium phosphate, layered two-dimensional filler, cation-modified nanocellulose, leveling agent, curing agent and diluent to obtain the marine anti-corrosion coating.

[0066] In the present invention, the method of mixing the epoxy resin, irradiated modified polytetrafluoroethylene, modified graphene, lithium phosphate, layered two-dimensional filler, cation-modified nanocellulose, leveling agent, curing agent and diluent is preferably: first stirring the epoxy resin, irradiated modified polytetrafluoroethylene, modified graphene, lithium phosphate, layered two-dimensional filler, cation-modified nanocellulose, leveling agent and diluent, and then adding the curing agent for second stirring.

[0067] In the present invention, the rotation speed of the first stirring is preferably 300 - 500 rpm / min, more preferably 400 - 500 rpm / min; the time of the first stirring is preferably 2 - 5 h, more preferably 3 - 4 h. In the present invention, the rotation speed of the second stirring is preferably 200 - 500 rpm / min, more preferably 300 - 400 rpm / min; the time of the second stirring is preferably 10 - 20 min, more preferably 10 - 15 min. Stirring under the above conditions in the present invention can make each component mix evenly to obtain a uniformly mixed marine anti-corrosion coating.

[0068] The preparation method provided by the present invention is simple to operate and easy to control, and can prepare marine anti-corrosion coatings on a large scale.

[0069] Next, the technical solutions in the present invention will be clearly and completely described in combination with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0070] The preparation method of the polyphenol compound loaded with copper oxide used in the embodiments of the present invention is as follows: (1) After ultrasonically mixing 6 g of quercetin, 1 g of graphene oxide and 100 mL of water evenly, a reduction reaction is carried out at 85 °C for 4 h. The suspension obtained from the reduction reaction is filtered and washed with water in sequence, and dried at 60 °C for 48 h to obtain polyphenol-modified graphene oxide; (2) Dissolve 1 g of the polyphenol-modified graphene oxide obtained in the step (1) and 5 g of copper nitrate in 50 mL of absolute ethanol, titrate with 0.5 mol / L NaOH solution to pH = 7, then react at 90 °C for 60 min, and then age for 48 h. After suction filtration and washing with water, it is dried at 60 °C for 48 h to obtain polyphenol compound-modified graphene oxide loaded with copper oxide, and the particle size is 40 - 50 nm.

[0071] The preparation method of the cation-modified nanocellulose used in the embodiments of the present invention is as follows: Mix evenly a 6% mass concentration nanocellulose suspension (bacterial nanocellulose), sodium hydroxide and 2,3-epoxypropyltrimethylammonium chloride to obtain a mixed slurry; the mass concentration of sodium hydroxide in the mixed slurry is 8%; the mass concentration of 2,3-epoxypropyltrimethylammonium chloride in the mixed slurry is 5%; React the mixed slurry at 130 °C for 5 h, and then carry out centrifugation, washing, dialysis and drying to obtain cation-modified nanocellulose.

[0072] The preparation method of the irradiated modified polytetrafluoroethylene used in the embodiments of the present invention is as follows: Carry out electron beam irradiation on polytetrafluoroethylene (TF-9207), wherein the irradiation dose of the electron beam irradiation is 100 KGy, the irradiation time of the electron beam irradiation is 8 h, and the beam current energy of the electron beam irradiation is 1 MeV; obtain irradiated modified polytetrafluoroethylene-1.

[0073] The preparation method of the irradiated modified polytetrafluoroethylene used in the embodiments of the present invention is as follows: Carry out electron beam irradiation on polytetrafluoroethylene (TF-9207), wherein the irradiation dose of the electron beam irradiation is 80 KGy, the irradiation time of the electron beam irradiation is 9 h, and the beam current energy of the electron beam irradiation is 1 MeV; obtain irradiated modified polytetrafluoroethylene-2.

[0074] The preparation method of the irradiated modified polytetrafluoroethylene used in the embodiments of the present invention is as follows: Carry out electron beam irradiation on polytetrafluoroethylene (TF-9207), wherein the irradiation dose of the electron beam irradiation is 150 KGy, the irradiation time of the electron beam irradiation is 7 h, and the beam current energy of the electron beam irradiation is 1 MeV; obtain irradiated modified polytetrafluoroethylene-3.

[0075] The binding ability of irradiated modified polytetrafluoroethylene-1, irradiated modified polytetrafluoroethylene-2 and irradiated modified polytetrafluoroethylene-3 with epoxy resin is similar. Therefore, in the examples of the present invention, the irradiated modified polytetrafluoroethylene used is irradiated modified polytetrafluoroethylene-1.

[0076] Example 1 A marine anti-corrosion coating, by weight, the components are: 45 parts of epoxy resin E51, 15 parts of irradiated modified polytetrafluoroethylene, 6 parts of polyphenol compound modified graphene oxide loaded with copper oxide, 4 parts of lithium iron phosphate, 5 parts of molybdenum disulfide, 3 parts of cation-modified bacterial nanocellulose, 0.5 part of leveling agent PV88, 15 parts of curing agent cycloaliphatic amine isophorone diamine and 300 parts of diluent ethanol; The preparation method of the marine anti-corrosion coating is: first stir epoxy resin, irradiated modified polytetrafluoroethylene, modified graphene, lithium-containing phosphate, layered two-dimensional filler, cation-modified nanocellulose, leveling agent and diluent at 450 rpm for 3 h, and then add the curing agent and stir at 450 rpm for 10 min.

[0077] Example 2 A marine anti-corrosion coating, by weight, the components are: 60 parts of epoxy resin E51, 18 parts of irradiated modified polytetrafluoroethylene, 7 parts of polyphenol compound modified graphene oxide loaded with copper oxide, 4 parts of lithium iron phosphate, 5 parts of molybdenum disulfide, 3 parts of cation-modified bacterial nanocellulose, 0.5 part of leveling agent PV88, 20 parts of curing agent cycloaliphatic amine isophorone diamine and 350 parts of diluent ethanol; The preparation method of the marine anti-corrosion coating is the same as that of Example 1.

[0078] Example 3 A marine anti-corrosion coating, by weight, the components are: 30 parts of epoxy resin E51, 15 parts of irradiated modified polytetrafluoroethylene, 6 parts of polyphenol compound modified graphene oxide loaded with copper oxide, 3 parts of lithium iron phosphate, 3 parts of graphite, 3 parts of cellulose nanowhiskers, 0.5 part of leveling agent PV88, 10 parts of curing agent cycloaliphatic amine isophorone diamine and 200 parts of diluent ethanol; The preparation method of the marine anti-corrosion coating is the same as that of Example 1.

[0079] Comparative Example 1 A marine anti-corrosion coating, by weight, the components are: 45 parts of epoxy resin E51, 15 parts of irradiated modified polytetrafluoroethylene, 6 parts of polyphenol compound modified graphene oxide loaded with copper oxide, 4 parts of lithium iron phosphate, 5 parts of molybdenum disulfide, 0.5 part of leveling agent PV88, 15 parts of curing agent cycloaliphatic amine isophorone diamine and 300 parts of diluent ethanol; The preparation method of the marine anti-corrosion coating is the same as that of Example 1.

[0080] Comparative Example 2 A marine anti-corrosion coating, by weight, the components are: 45 parts of epoxy resin E51, 15 parts of irradiated modified polytetrafluoroethylene, 6 parts of graphene oxide, 4 parts of lithium iron phosphate, 5 parts of molybdenum disulfide, 3 parts of cation-modified bacterial nanocellulose, 0.5 part of leveling agent PV88, 15 parts of curing agent cycloaliphatic amine isophorone diamine, and 300 parts of diluent ethanol; The preparation method of the marine anti-corrosion coating is the same as that of Example 1.

[0081] Comparative Example 3 A marine anti-corrosion coating, by weight, the components are: 45 parts of epoxy resin E51, 15 parts of polytetrafluoroethylene (TF-9207), 6 parts of polyphenol compound-modified graphene oxide loaded with copper oxide, 4 parts of lithium iron phosphate, 5 parts of molybdenum disulfide, 3 parts of cation-modified bacterial nanocellulose, 0.5 part of leveling agent PV88, 15 parts of curing agent cycloaliphatic amine isophorone diamine, and 300 parts of diluent ethanol; The preparation method of the marine anti-corrosion coating is the same as that of Example 1.

[0082] Comparative Example 4 A marine anti-corrosion coating, by weight, the components are: 45 parts of epoxy resin E51, 15 parts of irradiated modified polytetrafluoroethylene, 6 parts of copper oxide particles (10~50nm), 4 parts of lithium iron phosphate, 5 parts of molybdenum disulfide, 3 parts of cation-modified bacterial nanocellulose, 0.5 part of leveling agent PV88, 15 parts of curing agent cycloaliphatic amine isophorone diamine, and 300 parts of diluent water; The preparation method of the marine anti-corrosion coating is the same as that of Example 1.

[0083] Comparative Example 5 A marine anti-corrosion coating, by weight, the components are: 45 parts of epoxy resin E51, 15 parts of irradiated modified polytetrafluoroethylene, 6 parts of copper oxide particles (10~50nm), 4 parts of lithium iron phosphate, 5 parts of molybdenum disulfide, 3 parts of bacterial nanocellulose, 0.5 part of leveling agent PV88, 15 parts of curing agent cycloaliphatic amine isophorone diamine, and 300 parts of diluent water; The preparation method of the marine anti-corrosion coating is the same as that of Example 1.

[0084] Test Example 1 The performances of the marine anti-corrosion coatings obtained in Examples 1~3 and Comparative Examples 1~5 were detected, and the results are shown in Table 1: Table 1 Performance test results of the marine anti-corrosion coatings obtained in Examples 1~3 and Comparative Examples 1~5

[0085] As can be seen from the above results, compared with Example 1, the impact resistance and corrosion resistance of Comparative Example 1 decreased significantly. This is because compared with Example 1, cation-modified nanocellulose was not added in Comparative Example 1, and there is a good interfacial bonding ability between nanocellulose and modified graphene oxide, which improves the flexibility of the anti-corrosion coating. When nanocellulose is not added, cracks are likely to occur in the anti-corrosion coating under impact, and the existence of cracks will reduce the corrosion resistance of the coating.

[0086] Compared with Example 1, the antibacterial property and corrosion resistance of Comparative Example 2 both decreased. This is because the polyphenol compound-modified graphene oxide loaded with copper oxide was not added in Comparative Example 2, so the barrier property and conductivity of graphene could not be exerted, thereby reducing corrosion; at the same time, the bactericidal property of copper oxide could not be exerted, resulting in bacterial corrosion.

[0087] The antibacterial property of Comparative Example 3 decreased compared with Example 1. This is because polytetrafluoroethylene in Comparative Example 3 was not irradiated, and its combination with the epoxy resin of the coating was poor, resulting in the coating being unable to fully exert the anti-biofouling ability of polytetrafluoroethylene.

[0088] The antibacterial property of Comparative Example 4 decreased compared with Example 1. This is because although copper oxide was added to the coating, the binding ability of copper oxide with other components of the coating was relatively poor, and nanoscale copper oxide was prone to agglomeration and could not be fully dispersed in the coating, thereby resulting in the antibacterial property of the anti-corrosion coating of Comparative Example 4 being lower than that of Example 1.

[0089] Compared with Example 1, the adhesion, impact resistance, salt spray resistance, antibacterial property and corrosion resistance of Comparative Example 5 decreased slightly. This is because after the nanocellulose used in the present invention was cation-modified, the cation-modified nanocellulose can not only form hydrogen bonds with cellulose fibers, but also form bonds with nanocellulose through the charge neutralization mechanism, thereby improving the strength of the coating; and it can also enhance the interaction between the layered two-dimensional filler and modified graphene, and then be reflected in the coating to improve the various properties of the coating. Unmodified nanocellulose cannot form the above-mentioned combined effects, thereby resulting in the performance of the anti-corrosion coating of Comparative Example 5 being lower than that of Example 1.

[0090] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An anti-corrosion marine coating, characterized in that, By weight parts, it includes the following components: 25-75 parts of epoxy resin, 15-30 parts of irradiated modified polytetrafluoroethylene, 5-10 parts of modified graphene, 2-10 parts of lithium-containing phosphate, 2-10 parts of layered two-dimensional filler, 1-5 parts of cation-modified nanocellulose, 0.1-1 part of leveling agent, 10-20 parts of curing agent and 200-500 parts of diluent; The modified graphene is polyphenol compound-modified graphene oxide loaded with copper oxide.

2. The marine anti-corrosion coating according to claim 1, wherein The epoxy resin is bisphenol A epoxy resin.

3. The marine anti-corrosion coating according to claim 1, characterized in that, The preparation method of the polyphenol compound-modified graphene oxide loaded with copper oxide includes: (1) After mixing polyphenol compound, graphene oxide and water, a reduction reaction is carried out to obtain polyphenol-modified graphene oxide; (2) The polyphenol-modified graphene oxide obtained in the step (1) is mixed with soluble copper salt and solvent to obtain a suspension. The pH value of the suspension is adjusted to 6-8, and then reaction and aging are carried out in sequence to obtain polyphenol compound-modified graphene oxide loaded with copper oxide.

4. The marine anti-corrosion coating according to claim 3, characterized in that, The polyphenol compound in the step (1) includes one or more of quercetin, anthocyanin and catechin.

5. The marine anti-corrosion coating according to claim 3, wherein The mass ratio of the polyphenol compound to the graphene oxide in the step (1) is 1-10:

1.

6. The marine anti-corrosion coating according to claim 3, characterized in that, The temperature of the reaction in the step (2) is 85-90 °C; the reaction time is 30-60 min.

7. The marine anti-corrosion coating according to claim 1, characterized in that, The lithium-containing phosphate includes one or both of lithium iron phosphate and lithium manganese phosphate.

8. The marine anti-corrosion coating according to claim 1, wherein, The layered two-dimensional filler includes one or more of tungsten disulfide, graphite and talcum powder.

9. The marine anti-corrosion coating according to claim 1, wherein The nanocellulose in the cation-modified nanocellulose includes one or more of cellulose nanofibers, cellulose nanocrystals and bacterial nanocellulose.

10. The preparation method of the marine anti-corrosion coating according to any one of claims 1 to 9, comprising: Epoxy resin, irradiated modified polytetrafluoroethylene, modified graphene, lithium-containing phosphate, layered two-dimensional filler, cation-modified nanocellulose, leveling agent, curing agent and diluent are mixed to obtain a marine anti-corrosion coating.

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