An organic phosphorus-modified epoxy acrylic resin composite coating and its preparation method

Abstract

The present invention belongs to the technical field of anti-corrosion coatings, and discloses an organophosphorus-modified epoxy acrylic resin composite coating and a preparation method thereof. The present invention adopts a phosphorus oxide containing a benzene ring as a reactive group, and realizes the modification of acrylate by grafting an acrylate monomer through the ortho-C-H bond on the activated benzene ring. At the same time, the selected phosphorus oxide can also be connected with layered vermiculite and boron nitride through a covalent bond, which is beneficial to improve the dispersibility of inorganic fillers in the coating, avoid the occurrence of local agglomeration, and strengthen the compactness of the epoxy acrylic resin composite coating. In addition, the introduced organophosphorus compound can also undergo a strong chelating effect with the substrate, and form a stable metal salt passivation film through covalent bond and metal complexation to prevent the erosion of the medium, thereby further improving the salt resistance of the substrate. The modified water-based acrylic resin composite coating prepared by the present invention is green and environmentally friendly, has excellent salt spray resistance and chemical corrosion resistance, and can be widely used in the field of metal corrosion protection.

Description

Technical Field

[0001] The invention belongs to the field of functional organic polymer anti-corrosion coatings, and in particular relates to an organophosphorus-modified epoxy acrylic resin composite coating and a preparation method thereof. Background Art

[0002] Anti-corrosion coatings are widely used in the chemical, energy, construction, and offshore industries. They are primarily applied to substrates, which, after curing, form a coating that protects the substrate from corrosion by providing shielding, corrosion inhibition, and cathodic protection. Anti-corrosion coatings are generally categorized as solvent-based and water-based. Traditional solvent-based coatings release volatile organic compounds (VOCs) during production and use, polluting the environment.

[0003] Water-based anti-corrosion coatings are environmentally friendly coatings that use water as a solvent or dispersion medium. They offer advantages in terms of performance and transportability. Among various coating types, water-based epoxy acrylic resins combine the advantages of both epoxy and acrylic resins, offering excellent weather and chemical resistance, high gloss, and durability. They are widely used in the automotive, home appliance, and metal product industries. However, the salt spray resistance and corrosion resistance of water-based epoxy acrylic resins remain less than ideal and need further improvement. Adding inorganic nanomaterials to water-based epoxy acrylic resins is often an effective means of improving the overall performance of polymer coatings. For example, Chinese invention patent CN 103450773 A proposes that adding hollow insulating materials and reinforcing materials to the coatings prepared from them can effectively enhance the mechanical and corrosion resistance of the coatings. However, the small particle size of nanomaterials results in their high surface energy, leading to agglomeration, resulting in uneven distribution within the coating, affecting the overall performance of the coating and reducing its anti-corrosion effectiveness. Improving the uniformity of nanofillers and enhancing their compatibility with the coating solution are key to addressing the agglomeration problem. Therefore, the present invention still needs to develop a water-based epoxy acrylic resin with excellent anti-corrosion performance and a method for preparing the resin. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an organophosphorus-modified epoxy acrylic resin composite coating and a preparation method thereof. The coating has the advantages of easy implementation, low use cost, excellent salt resistance and chemical corrosion resistance, etc.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] The invention provides an organophosphorus-modified epoxy acrylic resin composite coating, which comprises the following components in parts by weight: 80-100 parts of deionized water, 40-80 parts of methyl methacrylate, 30-60 parts of ethyl acrylate, 1-12.5 parts of organophosphorus-modified acrylate, 0.5-5 parts of inorganic filler, 5-10 parts of modified epoxy resin, 15-50 parts of curing agent, 0.5-3 parts of emulsifier, 0.02-0.05 parts of defoaming agent, 0.02-0.05 parts of leveling agent, and 0.5-2 parts of initiator.

[0007] The organophosphorus-modified epoxy acrylic resin composite coating has the following structural formula:

[0008]

[0009] Wherein X = 1-15, Y = 10-200, Z = 10-200, W = 1-10, and n = 1-25. X can be 1-5, 5-10, or 10-15. Y can be 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, 90-100, 100-120, 120-140, 140-160, 160-180, or 180-200. Z can be 10-20, 20-40, 40-60, 60-80, 80-100, 100-120, 120-140, 140-160, 160-180, or 180-200. W can be 1-2, 2-4, 4-6, 6-8, or 8-10. n can be 1-5, 5-10, 10-15, 15-20, or 20-25.

[0010] In one embodiment, the modified epoxy resin is an acrylic acid-modified epoxy resin. The epoxy resin can be added to deionized water, heated for reaction, and then an equimolar amount of acrylic acid is added dropwise. After the addition is complete, the reaction is continued to produce the acrylic acid-modified epoxy resin. The heating reaction is performed at 80-100°C for 2-5 hours. The reaction formula is as follows:

[0011]

[0012] As an embodiment, the curing agent is a water-based resin curing agent. Further, the curing agent is a water-based amino resin or polyamide.

[0013] As an embodiment, the inorganic filler is vermiculite or boron nitride.

[0014] As an embodiment, the emulsifier is sodium dodecyl sulfate or sodium dodecylbenzene sulfonate.

[0015] As an embodiment, the defoaming agent is a fatty alcohol polyether compound.

[0016] As an embodiment, the leveling agent is polydimethylsiloxane or polymethylphenylsiloxane.

[0017] As an embodiment, the initiator is ammonium persulfate, potassium persulfate or sodium persulfate.

[0018] As an embodiment, the organophosphorus-modified acrylate is prepared by a method comprising the following steps: placing diethyl phenylphosphonate and acrylate in 1,2-dichloroethane to form a mixed solution, adding copper acetate as an oxidant thereto, carrying out a C-H bond olefination reaction under the action of an organic rhodium catalyst, cooling to room temperature after the reaction, distilling off the solvent under reduced pressure, and separating and purifying to obtain the organophosphorus-modified acrylate.

[0019] The reaction formula is as follows:

[0020]

[0021] R1=Me, Et, n-Bu.

[0022] As an embodiment, the acrylic acid ester is at least one of methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate.

[0023] As one embodiment, the temperature of the CH bond olefination reaction is 90-150° C., and the reaction time is 12-30 hours. In some implementation examples, the reaction temperature is 100-150° C., and the reaction time is 15-30 hours.

[0024] As an embodiment, the mass ratio of diethyl phenylphosphonate, acrylate, 1,2-dichloroethane, and copper acetate is 1:1-5:5-25:0.8-1.5. The amount of catalyst used is 0.5-3% of the total mass of the mixed solution.

[0025] The present invention also provides a method for preparing an organophosphorus-modified epoxy acrylic resin composite coating, the method comprising the following steps:

[0026] S1. Adding a pretreated inorganic filler (having a surface rich in hydroxyl groups) to anhydrous ethanol, adding a portion of an organophosphorus-modified acrylate and ethylenediamine after ultrasonic dispersion, carrying out a condensation reaction, filtering the solvent, and washing with deionized water and ethanol to obtain a functionalized inorganic filler modified with an organophosphorus-modified acrylate;

[0027] S2. Deionized water, the methyl methacrylate, ethyl acrylate, the remaining organophosphorus-modified ethyl acrylate, the modified inorganic filler, an emulsifier, and an initiator are added to the acrylic acid-modified epoxy resin and the reaction is continued to obtain a modified epoxy acrylic resin emulsion. The main reaction formula is as follows:

[0028]

[0029] S3, add deionized water, the defoamer, and the leveling agent to the modified epoxy acrylic resin emulsion, stir evenly, then add the curing agent, emulsify at high speed, and obtain the coating. When applied, the coating can be applied to a carbon steel surface and dried and cured.

[0030] As an embodiment, in step S1, when the inorganic filler is vermiculite, the pretreatment comprises heat-treating the vermiculite with a mixed solution of nitric acid and sulfuric acid, washing with deionized water, drying the filtered vermiculite, and then heat-treating it in a continuously flowing air stream to obtain expanded vermiculite. The heat treatment temperature is 500-900°C; the mass ratio of nitric acid to sulfuric acid is 10:(30-50).

[0031] As an embodiment, in step S1, when the inorganic filler is boron nitride, the pretreatment is to treat the boron nitride with a potassium hydroxide solution, filter the solvent, and dry to obtain hydroxylated boron nitride nanosheets. The concentration of the potassium hydroxide solution is 3-12 mol / L.

[0032] As an embodiment, in step S1, the mass ratio of the anhydrous ethanol, the inorganic filler, the organophosphorus modified acrylate, and the ethylenediamine is 50:1-2:1.5-5:0.5-1.

[0033] As an embodiment, in step S1, the reaction temperature of the condensation reaction is 50-90° C., and the reaction time is 1-6 h.

[0034] As an embodiment, in step S2, the modified epoxy acrylic resin emulsion is prepared by stirring at 40-90° C. for 1-5 hours.

[0035] As an embodiment, in step S3, the reaction temperature of the high-speed emulsification is 20-50°C, the stirring time is 0.5-3 hours, and the stirring speed is 600-2000 r / min. After the coating is applied to the carbon steel surface, the drying and curing time is 12-72 hours.

[0036] In some embodiments, the preparation of the organophosphorus-modified epoxy acrylic resin composite coating comprises the following steps:

[0037] (1) Diethyl phenylphosphonate and acrylic acid ester are placed in 1,2-dichloroethane to form a mixed solution, copper acetate as an oxidant is added thereto, and a C—H bond olefination reaction is carried out in the presence of an organic rhodium catalyst. After the reaction is completed, the mixture is cooled to room temperature, the solvent is evaporated under reduced pressure, and the mixture is separated and purified by silica gel chromatography to obtain a white solid product of an organic phosphorus-modified acrylic acid ester;

[0038] The reaction formula is as follows:

[0039]

[0040] R1=Me、Et、n-Bu

[0041] (2) treating vermiculite with a mixed acid solution of nitric acid and sulfuric acid, washing with deionized water, drying the filtered vermiculite, and then heat-treating it in a continuously flowing air stream to obtain expanded vermiculite; treating boron nitride with a potassium hydroxide solution, filtering the solvent, and drying to obtain hydroxylated boron nitride nanosheets. Adding the pretreated expanded vermiculite and boron nitride nanosheets to anhydrous ethanol, ultrasonically dispersing the solution, and adding organophosphorus-modified acrylate and ethylenediamine to carry out a condensation reaction, filtering the solvent, and washing with deionized water and ethanol to obtain a functionalized inorganic filler modified with organophosphorus-modified acrylate;

[0042] (3) adding epoxy resin to deionized water, heating for reaction, and adding an equimolar amount of acrylic acid dropwise. After the addition is complete, continuing the reaction to obtain an acrylic acid-modified epoxy resin; subsequently, adding deionized water, methyl methacrylate, ethyl acrylate, organophosphorus-modified ethyl acrylate, modified inorganic filler, emulsifier, and initiator, and continuing the reaction to obtain a modified epoxy acrylic resin emulsion;

[0043] The reaction formula is as follows:

[0044]

[0045]

[0046] (4) Deionized water, defoaming agent, and leveling agent are added to the modified epoxy acrylic resin emulsion, and after stirring evenly, a water-based resin curing agent is added. After high-speed emulsification, the coating is applied to the carbon steel surface and dried and cured.

[0047] The present invention also provides an application of the organic phosphorus-modified epoxy acrylic resin composite coating in the field of anti-corrosion coatings.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The present invention adopts a phosphorus oxide containing a benzene ring as a reactive group, takes advantage of the phosphine oxide as a weakly coordinated directing group, and activates the ortho-CH bond on the benzene ring through a catalyst to carry out an allylation reaction with an acrylate monomer, thereby achieving modification of the acrylate monomer. The rigid benzene ring on the organophosphorus compound increases the hardness and wear resistance of the polymer compound coating.

[0050] (2) The present invention also provides a new method for dispersing inorganic fillers. By pre-treating the inorganic filler, the surface of the inorganic filler is enriched with hydroxyl groups. Subsequently, an organophosphorus-modified acrylate monomer is introduced. The ethoxy groups in the organophosphorus can undergo a condensation reaction with the hydroxyl groups on the surface of the inorganic filler, thereby bonding the inorganic filler to the organophosphorus-modified acrylate monomer through a strong covalent bond. In the subsequent polymerization reaction, the inorganic filler is better embedded in the polymer coating as the reaction proceeds, thus solving the problem of easy agglomeration of the nano-inorganic filler, strengthening the density of the epoxy acrylic resin composite coating, inhibiting the penetration of electrolytes and water vapor, and improving the solvent resistance of the polymer.

[0051] (3) The introduced organophosphorus compound can also undergo a strong chelation reaction with the substrate, forming a stable metal salt passivation film through covalent bond complexation with the metal to prevent the erosion of the medium, further improving the salt resistance of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0053] Figure 1 This is a Fourier transform infrared spectrum of the organophosphorus-modified epoxy acrylic resin of the present invention. DETAILED DESCRIPTION

[0054] The present invention will be described in detail below with reference to the examples. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that those skilled in the art may make several adjustments and improvements without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0055] Example 1

[0056] A method for preparing an organophosphorus-modified epoxy acrylic resin composite coating comprises the following steps:

[0057] (1) Adding 10 parts by weight of diethyl phenylphosphonate and 15 parts by weight of ethyl acrylate to 50 parts by weight of 1,2-dichloroethane, and then adding 10 parts by weight of copper acetate, carrying out an olefination reaction in the presence of 1 part by weight of an organic rhodium catalyst at a temperature of 100° C. for 12 hours, cooling to room temperature, distilling off the solvent under reduced pressure, and separating and purifying by silica gel chromatography to obtain an organic phosphorus-modified acrylate white solid product;

[0058] (2) Boron nitride was treated with a 5 mol / L potassium hydroxide solution, filtered, and dried to obtain hydroxylated boron nitride nanosheets. 1 part by weight of the pretreated boron nitride nanosheets was added to 50 parts by weight of anhydrous ethanol, and after ultrasonic dispersion, 1.5 parts by weight of organophosphorus-modified acrylate and 0.5 parts by weight of ethylenediamine were added. The mixture was subjected to a dehydration condensation reaction at 80°C for 6 hours, the solvent was filtered, and the mixture was washed with deionized water and ethanol to obtain organophosphorus-modified acrylate-modified functionalized boron nitride nanosheets, i.e., modified boron nitride nanosheets.

[0059] (3) adding 20 parts by weight of epoxy resin to 60 parts by weight of deionized water, reacting at 90° C., adding an equal molar amount of acrylic acid dropwise, and continuing the reaction for 3 hours after the addition is complete to obtain an acrylic acid-modified epoxy resin;

[0060] Take 20 parts by weight of acrylic acid-modified epoxy resin, add 80 parts by weight of deionized water, 50 parts by weight of methyl methacrylate, 33 parts by weight of ethyl acrylate, 5 parts by weight of organophosphorus-modified ethyl acrylate, 2 parts by weight of modified boron nitride nanosheets, 1 part by weight of sodium dodecylbenzenesulfonate, and 1.5 parts by weight of ammonium persulfate, and continue reacting at 90°C for 3 hours to obtain a modified epoxy acrylic resin emulsion;

[0061] (4) Add 20 parts by weight of deionized water, 0.05 parts by weight of fatty alcohol polyoxyethylene ether, and 0.02 parts by weight of polydimethylsiloxane to the modified epoxy acrylic resin emulsion, stir evenly, and then add 5 parts by weight of water-based amino resin. After high-speed emulsification (reaction temperature is 50°C, stirring for 2 hours, stirring speed is 1000 r / min), the coating is applied to the surface of carbon steel, and dried and cured at 90°C for 24 hours to obtain an organophosphorus-modified epoxy acrylic resin coating film.

[0062] Figure 1 The following is a Fourier transform infrared spectrum of the organophosphorus-modified epoxy acrylic resin of this embodiment; it can be confirmed that the structural formula of the organophosphorus-modified epoxy acrylic resin prepared by the present invention is:

[0063]

[0064] Example 2

[0065] A method for preparing an organophosphorus-modified epoxy acrylic resin composite coating comprises the following steps:

[0066] (1) adding 10 parts by weight of diethyl phenylphosphonate and 15 parts by weight of ethyl acrylate to 50 parts by weight of 1,2-dichloroethane, and then adding 10 parts by weight of copper acetate, and carrying out an olefination reaction in the presence of 0.85 parts by weight of an organic rhodium catalyst at a temperature of 120° C. for 12 hours. The reaction was cooled to room temperature, and the solvent was evaporated under reduced pressure. The product was separated and purified by silica gel chromatography to obtain an organic phosphorus-modified acrylate white solid product;

[0067] (2) Vermiculite was treated with a mixed acid solution of nitric acid and sulfuric acid in a mass ratio of 1:3, washed with deionized water, filtered, dried, and calcined at 700°C for 6 hours to obtain expanded vermiculite. 1 part by weight of the pretreated expanded vermiculite was added to 50 parts by weight of anhydrous ethanol, and after ultrasonic dispersion, 2 parts by weight of organophosphorus-modified acrylate and 0.5 parts by weight of ethylenediamine were added, and a dehydration condensation reaction was carried out at 80°C for 6 hours. The solvent was filtered, and the product was washed with deionized water and ethanol to obtain functionalized expanded vermiculite modified with organophosphorus-modified acrylate, i.e., modified expanded vermiculite.

[0068] (3) adding 30 parts by weight of epoxy resin to 100 parts by weight of deionized water, reacting at 90° C., adding an equal molar amount of acrylic acid dropwise, and continuing the reaction for 3 hours after the addition is complete to obtain an acrylic acid-modified epoxy resin;

[0069] Take 30 parts by weight of acrylic acid-modified epoxy resin, add 80 parts by weight of deionized water, 50 parts by weight of methyl methacrylate, 30 parts by weight of ethyl acrylate, 5 parts by weight of organophosphorus-modified ethyl acrylate, 1 part by weight of modified expanded vermiculite, 0.8 parts by weight of sodium dodecylbenzenesulfonate, and 0.5 parts by weight of ammonium persulfate, and continue the reaction at 90°C for 3 hours to obtain a modified epoxy acrylic resin emulsion;

[0070] (4) Add 20 parts by weight of deionized water, 0.02 parts by weight of fatty alcohol polyoxyethylene ether, and 0.02 parts by weight of polydimethylsiloxane to the modified epoxy acrylic resin emulsion, stir evenly, and then add 10 parts by weight of water-based amino resin. After high-speed emulsification (reaction temperature is 30°C, stirring for 3 hours, stirring speed is 1500 r / min), the coating is applied to the carbon steel surface, and dried and cured at 90°C for 12 hours to obtain an organophosphorus-modified epoxy acrylic resin coating film.

[0071] Example 3

[0072] A method for preparing an organophosphorus-modified epoxy acrylic resin composite coating comprises the following steps:

[0073] (1) adding 10 parts by weight of diethyl phenylphosphonate and 25 parts by weight of ethyl acrylate to 50 parts by weight of 1,2-dichloroethane, and then adding 10 parts by weight of copper acetate, and carrying out an olefination reaction in the presence of 0.85 parts by weight of an organic rhodium catalyst at a temperature of 130° C. for 20 hours. The reaction was cooled to room temperature, and the solvent was evaporated under reduced pressure. The product was separated and purified by silica gel chromatography to obtain an organic phosphorus-modified acrylate white solid product;

[0074] (2) Boron nitride was treated with 8 mol / L potassium hydroxide solution, filtered, and dried to obtain hydroxylated boron nitride nanosheets. 1 part by weight of the pretreated boron nitride nanosheets was added to 50 parts by weight of anhydrous ethanol, and after ultrasonic dispersion, 2 parts by weight of organophosphorus-modified acrylate and 0.5 parts by weight of ethylenediamine were added. The mixture was subjected to a dehydration condensation reaction at 80°C for 6 hours, the solvent was filtered, and the mixture was washed with deionized water and ethanol to obtain organophosphorus-modified acrylate-modified functionalized boron nitride nanosheets, i.e., modified boron nitride nanosheets.

[0075] (3) adding 15 parts by weight of epoxy resin to 50 parts by weight of deionized water, reacting at 90° C., adding an equal molar amount of acrylic acid dropwise, and continuing the reaction for 3 hours after the addition is complete to obtain an acrylic acid-modified epoxy resin;

[0076] 15 parts by weight of acrylic acid-modified epoxy resin were added thereto, 80 parts by weight of deionized water, 80 parts by weight of methyl methacrylate, 30 parts by weight of ethyl acrylate, 3 parts by weight of organophosphorus-modified ethyl acrylate, 1 part by weight of modified boron nitride nanosheets, 0.8 parts by weight of sodium dodecylbenzenesulfonate, and 0.5 parts by weight of ammonium persulfate, and the reaction was continued at 90° C. for 3 hours to obtain a modified epoxy acrylic resin emulsion;

[0077] (4) Add 20 parts by weight of deionized water, 0.02 parts by weight of fatty alcohol polyoxyethylene ether, and 0.02 parts by weight of polydimethylsiloxane to the modified epoxy acrylic resin emulsion, stir evenly, and then add 10 parts by weight of water-based amino resin. After high-speed emulsification (reaction temperature is 40°C, stirring for 1.5 hours, stirring speed is 800 r / min), the coating is applied to the carbon steel surface, and dried and cured at 90°C for 12 hours to obtain an organophosphorus-modified epoxy acrylic resin coating film.

[0078] Example 4

[0079] A method for preparing an organophosphorus-modified epoxy acrylic resin composite coating comprises the following steps:

[0080] (1) Adding 10 parts by weight of diethyl phenylphosphonate and 15 parts by weight of ethyl acrylate to 50 parts by weight of 1,2-dichloroethane, and then adding 10 parts by weight of copper acetate, carrying out an olefination reaction in the presence of 0.85 parts by weight of an organic rhodium catalyst at a temperature of 130° C. for 24 hours, cooling to room temperature, distilling off the solvent under reduced pressure, and separating and purifying by silica gel chromatography to obtain an organic phosphorus-modified acrylate white solid product;

[0081] (2) Vermiculite was treated with a mixed acid solution of nitric acid and sulfuric acid in a mass ratio of 1:5, washed with deionized water, filtered, dried, and calcined at 700°C for 10 hours to obtain expanded vermiculite; boron nitride was treated with a 10 mol / L potassium hydroxide solution, filtered, and dried to obtain hydroxylated boron nitride nanosheets. 1 part by weight of the pretreated expanded vermiculite and boron nitride nanosheet mixture was added to 50 parts by weight of anhydrous ethanol, and after ultrasonic dispersion, 2.5 parts by weight of organophosphorus-modified acrylate and 0.5 parts by weight of ethylenediamine were added, and a dehydration condensation reaction was carried out at 80°C for 6 hours. The solvent was filtered, and the mixture was washed with deionized water and ethanol to obtain a functional inorganic filler modified with organophosphorus-modified acrylate, i.e., a modified inorganic filler.

[0082] (3) adding 50 parts by weight of epoxy resin to 150 parts by weight of deionized water, reacting at 80° C., adding an equal molar amount of acrylic acid dropwise, and continuing the reaction for 5 hours after the addition is complete to obtain an acrylic acid-modified epoxy resin;

[0083] Take 50 parts by weight of acrylic acid-modified epoxy resin; add 80 parts by weight of deionized water, 40 parts by weight of methyl methacrylate, 60 parts by weight of ethyl acrylate, 10 parts by weight of organophosphorus-modified ethyl acrylate, 5 parts by weight of modified inorganic filler, 1 part by weight of sodium dodecylbenzenesulfonate, and 2 parts by weight of ammonium persulfate, and continue the reaction at 90°C for 3 hours to obtain a modified epoxy acrylic resin emulsion;

[0084] (4) 10 parts by weight of deionized water, 0.02 parts by weight of fatty alcohol polyoxyethylene ether, and 0.05 parts by weight of polydimethylsiloxane were added to the modified epoxy acrylic resin emulsion, and after stirring evenly, 10 parts by weight of water-based amino resin was added. After high-speed emulsification (reaction temperature was 25°C, stirring for 2 hours, and stirring speed was 1200 r / min), the coating was applied to the carbon steel surface, and dried and cured at 90°C for 48 hours to obtain an organophosphorus-modified epoxy acrylic resin coating film.

[0085] Comparative Example 1

[0086] This comparative example is compared with Example 1, and no organophosphorus modification treatment is added. The specific steps are as follows:

[0087] (1) Boron nitride is treated with 5 mol / L potassium hydroxide solution, filtered, and dried to obtain hydroxylated boron nitride nanosheets.

[0088] (2) adding 20 parts by weight of epoxy resin to 60 parts by weight of deionized water, reacting at 90° C., adding an equal molar amount of acrylic acid dropwise, and continuing the reaction for 3 hours after the addition is complete to obtain an acrylic acid-modified epoxy resin;

[0089] Take 20 parts by weight of acrylic acid-modified epoxy resin, add 80 parts by weight of deionized water, 50 parts by weight of methyl methacrylate, 33 parts by weight of ethyl acrylate, 2 parts by weight of boron nitride nanosheets, 1 part by weight of sodium dodecylbenzenesulfonate, and 1.5 parts by weight of ammonium persulfate, and continue reacting at 90°C for 3 hours to obtain a modified epoxy acrylic resin emulsion;

[0090] (3) Add 20 parts by weight of deionized water, 0.05 parts by weight of fatty alcohol polyoxyethylene ether, and 0.02 parts by weight of polydimethylsiloxane to the epoxy acrylic resin emulsion, stir evenly, and then add 5 parts by weight of water-based amino resin. After high-speed emulsification (reaction temperature is 50°C, stirring for 2 hours, stirring speed is 1000r / min), apply the coating to the carbon steel surface, dry and cure at 90°C for 24 hours to obtain an epoxy acrylic resin coating film.

[0091] Comparative Example 2

[0092] This comparative example is for comparison with Example 2, and does not use organophosphorus-modified inorganic filler. The specific steps are as follows:

[0093] (1) adding 10 parts by weight of diethyl phenylphosphonate and 15 parts by weight of ethyl acrylate to 50 parts by weight of 1,2-dichloroethane, and then adding 10 parts by weight of copper acetate, and carrying out an olefination reaction in the presence of 0.85 parts by weight of an organic rhodium catalyst at a temperature of 120° C. for 12 hours. The reaction was cooled to room temperature, and the solvent was evaporated under reduced pressure. The product was separated and purified by silica gel chromatography to obtain an organic phosphorus-modified acrylate white solid product;

[0094] (2) Vermiculite was treated with a mixed acid solution of nitric acid and sulfuric acid in a mass ratio of 1:3, washed with deionized water, filtered, dried, and calcined at 700°C for 6h to obtain expanded vermiculite.

[0095] (3) adding 30 parts by weight of epoxy resin to 100 parts by weight of deionized water, reacting at 90° C., adding an equal molar amount of acrylic acid dropwise, and continuing the reaction for 3 hours after the addition is complete to obtain an acrylic acid-modified epoxy resin;

[0096] Take 30 parts by weight of acrylic acid-modified epoxy resin, add 80 parts by weight of deionized water, 50 parts by weight of methyl methacrylate, 30 parts by weight of ethyl acrylate, 7 parts by weight of organophosphorus-modified ethyl acrylate, 1 part by weight of expanded vermiculite, 0.8 parts by weight of sodium dodecylbenzenesulfonate, and 0.5 parts by weight of ammonium persulfate, and continue the reaction at 90°C for 3 hours to obtain a modified epoxy acrylic resin emulsion;

[0097] (4) Add 20 parts by weight of deionized water, 0.02 parts by weight of fatty alcohol polyoxyethylene ether, and 0.02 parts by weight of polydimethylsiloxane to the modified epoxy acrylic resin emulsion, stir evenly, and then add 10 parts by weight of water-based amino resin. After high-speed emulsification (reaction temperature is 30°C, stirring for 3 hours, stirring speed is 1500 r / min), the coating is applied to the carbon steel surface, and dried and cured at 90°C for 12 hours to obtain an organophosphorus-modified epoxy acrylic resin coating film.

[0098] Comparative Example 3

[0099] This comparative example is compared with Example 3, using methacryloyloxyethyl phosphate instead of diethyl phenylphosphonate, and the specific steps are as follows:

[0100] (1) adding 10 parts by weight of methacryloyloxyethyl phosphate and 25 parts by weight of ethyl acrylate to 50 parts by weight of 1,2-dichloroethane, and then adding 10 parts by weight of copper acetate, and carrying out an olefination reaction in the presence of 0.85 parts by weight of an organic rhodium catalyst at a temperature of 130° C. for 20 hours. The reaction was cooled to room temperature, and the solvent was evaporated under reduced pressure. The product was separated and purified by silica gel chromatography to obtain an organic phosphorus-modified acrylate white solid product;

[0101] (2) Boron nitride was treated with 8 mol / L potassium hydroxide solution, filtered, and dried to obtain hydroxylated boron nitride nanosheets. 1 part by weight of the pretreated boron nitride nanosheets was added to 50 parts by weight of anhydrous ethanol, and after ultrasonic dispersion, 2 parts by weight of organophosphorus-modified acrylate and 0.5 parts by weight of ethylenediamine were added. The mixture was subjected to a dehydration condensation reaction at 80°C for 6 hours, the solvent was filtered, and the mixture was washed with deionized water and ethanol to obtain organophosphorus-modified acrylate-modified functionalized boron nitride nanosheets, i.e., modified boron nitride nanosheets.

[0102] (3) adding 15 parts by weight of epoxy resin to 50 parts by weight of deionized water, reacting at 90° C., adding an equal molar amount of acrylic acid dropwise, and continuing the reaction for 3 hours after the addition is complete to obtain an acrylic acid-modified epoxy resin;

[0103] 15 parts by weight of acrylic acid-modified epoxy resin were added thereto, 80 parts by weight of deionized water, 80 parts by weight of methyl methacrylate, 30 parts by weight of ethyl acrylate, 3 parts by weight of organophosphorus-modified ethyl acrylate, 1 part by weight of modified boron nitride nanosheets, 0.8 parts by weight of sodium dodecylbenzenesulfonate, and 0.5 parts by weight of ammonium persulfate, and the reaction was continued at 90° C. for 3 hours to obtain a modified epoxy acrylic resin emulsion;

[0104] (4) Add 20 parts by weight of deionized water, 0.02 parts by weight of fatty alcohol polyoxyethylene ether, and 0.02 parts by weight of polydimethylsiloxane to the modified epoxy acrylic resin emulsion, stir evenly, and then add 10 parts by weight of water-based amino resin. After high-speed emulsification (reaction temperature is 40°C, stirring for 1.5 hours, stirring speed is 800 r / min), the coating is applied to the carbon steel surface, and dried and cured at 90°C for 12 hours to obtain an organophosphorus-modified epoxy acrylic resin coating film.

[0105] test

[0106] Examples 1-4 and Comparative Examples 1-3 were placed in a salt spray test chamber to conduct salt spray resistance tests and mechanical property tests.

[0107] The corrosion resistance test is carried out in accordance with GB / T 1771-2007 “Paints and varnishes - Determination of resistance to neutral salt spray”.

[0108] The test of paint film pencil hardness is carried out in accordance with GB / T 6739-2006 "Colored paints and coatings - Determination of paint film hardness by pencil method".

[0109] The wear resistance is tested in accordance with GB / T 1768-2006 “Determination of abrasion resistance of paint films”.

[0110] Table 1 Salt spray resistance test of organophosphorus modified epoxy acrylic resin coating

[0111]

[0112] Table 2 Mechanical properties test of organophosphorus modified epoxy acrylic resin

[0113]

[0114] As can be seen from Table 1, compared with Comparative Example 1, Example 1 adds an organophosphorus modification treatment, and the resulting coating has improved salt spray resistance and mechanical properties. Compared with Comparative Example 2, Example 2 adds a modified inorganic filler, and the resulting coating has significantly improved salt spray resistance and mechanical properties. Compared with Comparative Example 3, Example 3 uses diethyl phenylphosphonate with a rigid benzene ring. This organophosphorus can better condense with the hydroxyl groups on the surface of the inorganic filler, and the benzene ring has better wear resistance, resulting in a coating with better salt spray resistance and mechanical properties.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An organophosphorus-modified epoxy acrylic resin composite coating, characterized in that: The coating comprises the following components in parts by weight: 80-100 parts of deionized water, 40-80 parts of methyl methacrylate, 30-60 parts of ethyl acrylate, 1-12.5 parts of organophosphorus-modified acrylate, 0.5-5 parts of inorganic filler, 15-50 parts of acrylic acid-modified epoxy resin, 5-10 parts of curing agent, 0.5-3 parts of emulsifier, 0.02-0.05 parts of defoaming agent, 0.02-0.05 parts of leveling agent, and 0.5-2 parts of initiator; The waterborne epoxy acrylic resin composite coating has the following structural formula: Wherein X=1-15, Y=10-200, Z=10-200, W=1-10, n=1-25; The organophosphorus-modified acrylate is prepared by a method comprising the following steps: placing diethyl phenylphosphonate and acrylate in 1,2-dichloroethane to form a mixed solution, adding copper acetate as an oxidant, carrying out a C-H bond olefination reaction under the action of an organic rhodium catalyst, cooling to room temperature after the reaction, distilling off the solvent under reduced pressure, and separating and purifying to obtain the organophosphorus-modified acrylate.

2. The organophosphorus-modified epoxy acrylic resin composite coating according to claim 1, characterized in that: The inorganic filler is vermiculite or boron nitride; the curing agent is water-based amino resin or polyamide; the emulsifier is sodium dodecyl sulfate or sodium dodecylbenzene sulfonate; the defoamer is a fatty alcohol polyether compound; the leveling agent is polydimethylsiloxane or polymethylphenylsiloxane; and the initiator is ammonium persulfate, potassium persulfate or sodium persulfate.

3. The organophosphorus-modified epoxy acrylic resin composite coating according to claim 1, characterized in that: In the preparation of organophosphorus modified acrylate, the acrylate is methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, or hydroxybutyl acrylate; the temperature of the CH bond olefination reaction is 90-150° C., and the reaction time is 12-30 hours.

4. A method for preparing an organophosphorus-modified epoxy acrylic resin composite coating according to claim 1, characterized in that: The method comprises the following steps: S1. Add the pretreated inorganic filler to anhydrous ethanol, add a portion of the organophosphorus-modified acrylate and ethylenediamine after ultrasonic dispersion, carry out a condensation reaction, filter the solvent, and wash with deionized water and ethanol to obtain a functionalized inorganic filler modified with the organophosphorus-modified acrylate, i.e., a modified inorganic filler; S2, adding deionized water, the methyl methacrylate, ethyl acrylate, the remaining organophosphorus-modified acrylate, the modified inorganic filler, the emulsifier, and the initiator to the acrylic acid-modified epoxy resin, and continuing the reaction to obtain a modified epoxy acrylic resin emulsion; S3. Add deionized water, the defoamer, and the leveling agent to the modified epoxy acrylic resin emulsion, stir evenly, then add the curing agent, and emulsify at high speed to obtain the coating.

5. The method for preparing the organophosphorus-modified epoxy acrylic resin composite coating according to claim 4, wherein: In step S1, when the inorganic filler is vermiculite, the pretreatment is to heat-treat the vermiculite with a mixed acid solution of nitric acid and sulfuric acid, wash with deionized water, dry the filtered vermiculite, and then heat-treat it in a continuously flowing air to obtain expanded vermiculite; when the inorganic filler is boron nitride, the pretreatment is to treat the boron nitride with a potassium hydroxide solution, filter the solvent, and dry it to obtain hydroxylated boron nitride nanosheets.

6. The method for preparing the organophosphorus-modified epoxy acrylic resin composite coating according to claim 5, wherein: The heat treatment temperature is 500-900° C.; the concentration of the potassium hydroxide solution is 3-12 mol / L.

7. The method for preparing the organophosphorus-modified epoxy acrylic resin composite coating according to claim 4, wherein: In step S1, the mass ratio of the anhydrous ethanol, the inorganic filler, the organophosphorus modified acrylate, and the ethylenediamine is 50:1-2:1.5-5:0.5-1.

8. The method for preparing the organophosphorus-modified epoxy acrylic resin composite coating according to claim 4, wherein: In step S1, the reaction temperature of the condensation reaction is 50-90° C., and the reaction time is 1-6 hours.

9. An anti-corrosion application of the organophosphorus-modified epoxy acrylic resin composite coating as claimed in claim 1 on metal surfaces.

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