Nanocomposite coating materials and coatings, and methods of making and using the same

Abstract

The present application relates to the technical field of coating modification, and discloses a kind of nano composite coating material and coating and its preparation method and application.The nano composite coating material of the present application contains 90-98% by weight of styrene / vinyl acetate copolymer and 2-10% by weight of silane coupling agent modified nanosilica.The coating using the nano composite coating material of the present application has strong adhesion, strong impact resistance, and excellent corrosion protection effect.

Description

Technical Field

[0001] This invention relates to the field of coating modification technology, specifically to a nanocomposite coating material and coating, its preparation method, and its application. Background Technology

[0002] Corrosion is a significant problem in the oilfield industry. The most important factors influencing the increased corrosion rate of oil pipelines are the high salinity of formation water, hydrogen sulfide (H2S), and carbon dioxide (CO2) gases produced during crude oil production. The oilfield industry is divided into three main segments based on function, process, and operation. First, the upstream oil and gas production segment: Upstream activities include exploration, drilling, and extraction processes. Natural gas and crude oil streams from production wells can be dry or wet, depending on their water content and impurities. The presence of impurities such as salts and chlorides in the produced water increases the corrosion rate, leading to localized erosion. In addition to the impact of impurities on the corrosion rate, other factors such as temperature, pressure, flow rate, heat transfer, the percentage of associated water, and the salt content in the producing crude oil all increase the corrosion rate of carbon steel pipelines. The corrosion rate of upstream oil and gas pipelines can be reduced by using organic corrosion inhibitors or coating the surface of carbon steel pipelines with highly water-resistant materials. Second, the midstream segment: Midstream activities include storage tanks, processing facilities, and the transportation of processed crude oil and natural gas. Changes in temperature and pressure at the gathering manifold and / or wellhead lead to a significant increase in dissolved oxygen (DO), which in turn increases the corrosion rate of midstream facilities. Corrosion prevention is one of the most important considerations for protecting production assets from corrosion. Third, the downstream sector: This sector specializes in refining and converting processed crude oil and natural gas into finished products. Summary of the Invention

[0003] The purpose of this invention is to provide a new nanocomposite coating material and coating, its preparation method and application. The coating using the nanocomposite coating material of this invention has strong adhesion, strong impact resistance and excellent anti-corrosion effect.

[0004] Through in-depth research, the inventors of this invention discovered that by using a nanocomposite coating material containing a specific ratio of styrene / vinyl acetate copolymer and silane coupling agent to modify nano-silica, the resulting coating exhibits strong adhesion, high impact resistance, and superior corrosion resistance, thus completing this invention.

[0005] Therefore, the first aspect of the present invention provides a nanocomposite coating material, wherein the nanocomposite coating material contains 90-98% by weight of styrene / vinyl acetate copolymer and 2-10% by weight of silane coupling agent modified nano-silica.

[0006] Preferably, the nanocomposite coating material contains 95-97% by weight of styrene / vinyl acetate copolymer and 3-5% by weight of silane coupling agent modified nano-silica.

[0007] Preferably, the styrene / vinyl acetate copolymer contains 30-60 mol% of structural units derived from styrene and 40-70 mol% of structural units derived from vinyl acetate; more preferably, the styrene / vinyl acetate copolymer contains 30-45 mol% of structural units derived from styrene and 55-70 mol% of structural units derived from vinyl acetate.

[0008] Preferably, the silane coupling agent in the silane coupling agent modified nano-silica is hexadecyltrimethoxysilane and / or dodecyltriethoxysilane.

[0009] According to a second aspect of the present invention, a coating is provided, wherein the coating contains the nanocomposite coating material described in the first aspect of the present invention and an organic solvent.

[0010] Preferably, the nanocomposite coating material is 1-10 parts by weight relative to 100 parts by weight of the organic solvent.

[0011] Preferably, the organic solvent is one or more of toluene, xylene, and benzene.

[0012] According to a third aspect of the present invention, a method for preparing a coating is provided, wherein the method includes the following steps: 1) The step of emulsion polymerization of an emulsion containing an emulsifier and a polymerizing monomer in the presence of an initiator to obtain a styrene / vinyl acetate copolymer; 2) Steps for preparing silane coupling agent-modified nano-silica; 3) The step of mixing the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica in the presence of an organic solvent. The polymer monomer contains styrene and vinyl acetate.

[0013] Preferably, in step 1), the emulsifier is one or more of polyoxyethylene lauryl ether, polyethylene oxide-polypropylene oxide block copolymer, and sodium dialkyl succinate sulfonate.

[0014] Preferably, the amount of the emulsifier is 1-15 parts by weight, more preferably 10-15 parts by weight, relative to 100 parts by weight of the polymeric monomer.

[0015] Preferably, in step 1), the polymeric monomer is added dropwise to an aqueous solution containing an emulsifier to form the emulsion.

[0016] Preferably, the amount of water used is 500-1000 parts by weight relative to 100 parts by weight of polymer monomer, more preferably 600-900 parts by weight.

[0017] Preferably, in step 1), the initiator is a persulfate, preferably one or more of ammonium persulfate, sodium persulfate, and potassium persulfate.

[0018] Preferably, the initiator is used in an amount of 1-5 parts by weight, more preferably 1-3 parts by weight, relative to 100 parts by weight of the polymerizing monomer.

[0019] Preferably, in step 1), the conditions for emulsion polymerization include: a polymerization temperature of 50-80℃ and a polymerization time of 1-5h.

[0020] Preferably, in step 2), the silane coupling agent modified nano-silica is obtained by contacting and modifying the silane coupling agent with nano-silica in the presence of a solvent.

[0021] Preferably, the silane coupling agent is hexadecyltrimethoxysilane and / or dodecyltriethoxysilane.

[0022] Preferably, the amount of the silane coupling agent is 50-120 parts by weight, more preferably 80-100 parts by weight, relative to 100 parts by weight of the nano-silica.

[0023] Preferably, the amount of solvent used is 1500-4500 parts by weight, more preferably 1700-2000 parts by weight, relative to 100 parts by weight of the nano-silica.

[0024] Preferably, the solvent is one or more of toluene, xylene, and benzene.

[0025] Preferably, in step 3), the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica is 1-10 parts by weight relative to 100 parts by weight of the organic solvent.

[0026] Preferably, the organic solvent is one or more of toluene, xylene, and benzene.

[0027] Preferably, in step 3), based on the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica, the content of the styrene / vinyl acetate copolymer is 90-98% by weight, and the content of the silane coupling agent modified nano-silica is 2-10% by weight; more preferably, based on the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica, the content of the styrene / vinyl acetate copolymer is 95-97% by weight, and the content of the silane coupling agent modified nano-silica is 3-5% by weight.

[0028] Preferably, the coating is obtained by mixing a first dispersion containing the styrene / vinyl acetate copolymer and a second dispersion containing the silane coupling agent-modified nano-silica.

[0029] According to a fourth aspect of the present invention, a coating is provided, wherein it is prepared by the method described in the third aspect of the present invention.

[0030] According to a fourth aspect of the present invention, the application of the coating described in the second or fourth aspect of the present invention in the preparation of anti-corrosion articles is provided.

[0031] Through the above technical solutions, the present invention can provide a new nanocomposite coating material and coating, its preparation method and application. The coating using the nanocomposite coating material of the present invention has strong adhesion, strong impact resistance and excellent anti-corrosion effect. Detailed Implementation

[0032] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0033] According to a first aspect of the present invention, a nanocomposite coating material is provided, wherein the nanocomposite coating material contains 90-98% by weight of a styrene / vinyl acetate copolymer and 2-10% by weight of silane coupling agent modified nano-silica.

[0034] According to a first aspect of the present invention, by having the contents of the styrene / vinyl acetate copolymer and the silane coupling agent nano silica within the above-mentioned range, excellent adhesion, impact resistance and corrosion resistance can be achieved. From the perspective of further improving adhesion, impact resistance and corrosion resistance, preferably, the nanocomposite coating material contains 95-97% by weight of styrene / vinyl acetate copolymer and 3-5% by weight of silane coupling agent modified nano silica.

[0035] Specific examples of the styrene / vinyl acetate copolymer content include, for example, 90% by weight, 91% by weight, 92% by weight, 93% by weight, 94% by weight, 95% by weight, 96% by weight, 97% by weight, 98% by weight, etc., as well as any two of the above ranges.

[0036] Specific examples of the content of nano-silica modified by the silane coupling agent include, for example, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, etc., as well as any two of the above ranges.

[0037] According to a first aspect of the invention, the styrene / vinyl acetate copolymer contains 30-60 mol% structural units derived from styrene and 40-70 mol% structural units derived from vinyl acetate. Preferably, from the viewpoint of further improving adhesion and impact resistance, the styrene / vinyl acetate copolymer contains 30-45 mol% structural units derived from styrene and 55-70 mol% structural units derived from vinyl acetate.

[0038] In this invention, the molar content of structural units in the styrene / vinyl acetate copolymer can be defined based on the molar ratio of the corresponding comonomers used.

[0039] In a particularly preferred embodiment of the present invention, the styrene / vinyl acetate copolymer is prepared by the method described in the third aspect of the present invention, which will be described later.

[0040] According to a first aspect of the present invention, preferably, the particle size of the silane coupling agent modified nano-silica is 50-300 nm; more preferably, the particle size of the silane coupling agent modified nano-silica is 100-200 nm.

[0041] In this invention, the particle size of the silane coupling agent modified nano-silica refers to the longest straight-line distance between two points on the silane coupling agent modified nano-silica.

[0042] The silane coupling agent used in the silane coupling agent-modified nano-silica can be a monoalkyltrialkoxysilane, preferably C14-2 ...10-18 Monoalkyl triC 1-3 Alkoxysilanes, particularly hexadecyltrimethoxysilane and / or dodecyltriethoxysilane.

[0043] In a particularly preferred embodiment of the present invention, the silane coupling agent modified nano-silica is prepared by the method described in the third aspect of the present invention, which will be described later.

[0044] According to a second aspect of the present invention, a coating is provided, wherein the coating contains the nanocomposite coating material described in the first aspect of the present invention and an organic solvent.

[0045] According to a second aspect of the invention, preferably, the nanocomposite coating material is 1-10 parts by weight relative to 100 parts by weight of the organic solvent; more preferably, the nanocomposite coating material is 3-5 parts by weight relative to 100 parts by weight of the organic solvent.

[0046] According to a second aspect of the present invention, preferably, the organic solvent is one or more selected from toluene, xylene, and benzene; more preferably, the organic solvent is toluene.

[0047] According to a second aspect of the present invention, the coating is obtained by mixing the nanocomposite coating material described in the first aspect of the present invention with an organic solvent.

[0048] In this invention, the coating can be obtained by mixing a first dispersion containing the styrene / vinyl acetate copolymer with the silane coupling agent-modified nano-silica, or by mixing the styrene / vinyl acetate copolymer with a second dispersion containing the silane coupling agent-modified nano-silica, or by mixing the first dispersion containing the styrene / vinyl acetate copolymer with a second dispersion containing the silane coupling agent-modified nano-silica, or by mixing a mixture of the styrene / vinyl acetate copolymer and the silane coupling agent-modified nano-silica with the organic solvent. Preferably, the coating is obtained by mixing the first dispersion containing the styrene / vinyl acetate copolymer with the second dispersion containing the silane coupling agent-modified nano-silica.

[0049] According to a third aspect of the present invention, a method for preparing a coating is provided, wherein the method includes the following steps: 1) The step of emulsion polymerization of an emulsion containing an emulsifier and a polymerizing monomer in the presence of an initiator to obtain a styrene / vinyl acetate copolymer; 2) Steps for preparing silane coupling agent-modified nano-silica; 3) The step of mixing the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica in the presence of an organic solvent. The polymer monomer contains styrene and vinyl acetate.

[0050] According to a third aspect of the invention, preferably, the polymeric monomers are styrene and vinyl acetate.

[0051] In this invention, preferably, the molar ratio of styrene to vinyl acetate is (30-60):(40-70). More preferably, from the viewpoint of further improving the adhesion and impact resistance of the coating, the molar ratio of styrene to vinyl acetate is (45-60):(55-70).

[0052] According to a third aspect of the invention, the emulsifier may be any of the various emulsifiers commonly used in emulsion polymerization reactions. Preferably, the emulsifier is one or more selected from polyoxyethylene lauryl ether, polyethylene oxide-polypropylene oxide block copolymer, and sodium dialkyl succinate sulfonate.

[0053] Examples of polyoxyethylene lauryl ethers mentioned above include, for example, polyoxyethylene (4) lauryl ether.

[0054] Examples of the above-mentioned polyethylene oxide-polypropylene oxide block copolymers include, for example, polyethylene oxide (80)-polypropylene oxide (27) block copolymers.

[0055] Examples of sodium dialkyl succinate sulfonate include, for example, sodium dibutyl succinate sulfonate, sodium dihexyl succinate sulfonate, and sodium dioctyl succinate sulfonate.

[0056] According to a third aspect of the invention, the amount of the emulsifier can be selected according to the amount of the polymeric monomer. Preferably, the amount of the emulsifier is 1-15 parts by weight relative to 100 parts by weight of the polymeric monomer; more preferably, the amount of the emulsifier is 5-15 parts by weight relative to 100 parts by weight of the polymeric monomer; even more preferably, the amount of the emulsifier is 8-15 parts by weight relative to 100 parts by weight of the polymeric monomer; particularly preferably, the amount of the emulsifier is 10-15 parts by weight relative to 100 parts by weight of the polymeric monomer.

[0057] Specific examples of the amount of emulsifier relative to 100 parts by weight of the polymeric monomer include, for example, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, etc., as well as any two of the above ranges.

[0058] According to a third aspect of the present invention, preferably, in step 1), the polymeric monomer is added dropwise to an aqueous solution containing an emulsifier to form the emulsion.

[0059] In this invention, the aqueous solution containing the emulsifier is obtained by dispersing the emulsifier in water. The dispersion method can employ various devices or methods commonly used in the art for dispersion, such as dispersion by stirring.

[0060] Preferably, the amount of water used is 500-1000 parts by weight relative to 100 parts by weight of the polymer monomer; more preferably, the amount of water used is 600-900 parts by weight relative to 100 parts by weight of the polymer monomer.

[0061] Preferably, the dripping temperature is 5-45°C, more preferably at room temperature.

[0062] According to a third aspect of the invention, preferably, in step 1), the initiator is a persulfate; more preferably, in step 1), the initiator is one or more of ammonium persulfate, sodium persulfate, and potassium persulfate.

[0063] In this invention, the amount of the initiator can be selected according to the amount of the polymeric monomer. Preferably, the amount of the initiator is 1-5 parts by weight relative to 100 parts by weight of the polymeric monomer; more preferably, the amount of the initiator is 1-3 parts by weight relative to 100 parts by weight of the polymeric monomer.

[0064] Specific examples of the amount of initiator relative to 100 parts by weight of the polymerizing monomer include, for example, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, and any two of the above ranges.

[0065] In this invention, the initiator is preferably used in the form of an aqueous solution. When used in the form of an aqueous solution, its concentration can be 5-15% by weight, preferably 8-12% by weight.

[0066] According to a third aspect of the present invention, preferably, in step 1), the conditions for emulsion polymerization include: a polymerization temperature of 50-80°C and a polymerization time of 1-5 h.

[0067] According to a third aspect of the present invention, preferably, in step 2), the particle size of the silane coupling agent modified nano-silica is 50-300 nm; more preferably, the particle size of the silane coupling agent modified nano-silica is 100-200 nm.

[0068] As the silane coupling agent, a monoalkyltrialkoxysilane can be used, preferably C1450. 10-18 Monoalkyl triC 1-3Alkoxysilanes, particularly hexadecyltrimethoxysilane and / or dodecyltriethoxysilane.

[0069] According to a third aspect of the present invention, preferably, the silane coupling agent modified nano-silica is obtained by contact modification of the silane coupling agent with nano-silica in the presence of a solvent; more preferably, the silane coupling agent modified nano-silica is obtained by contact modification of the silane coupling agent with a dispersion in which nano-silica is dispersed.

[0070] The above-mentioned dispersion containing nano-silica is preferably obtained by dispersing the nano-silica in the solvent using an ultrasonic method.

[0071] Preferably, the amount of the silane coupling agent is 50-120 parts by weight relative to 100 parts by weight of the nano-silica; more preferably, the amount of the silane coupling agent is 80-100 parts by weight relative to 100 parts by weight of the nano-silica.

[0072] Preferably, the amount of solvent used is 1500-4500 parts by weight relative to 100 parts by weight of the nano-silica; more preferably, the amount of solvent used is 1700-2000 parts by weight relative to 100 parts by weight of the nano-silica.

[0073] Preferably, the solvent is one or more of toluene, xylene, and benzene; more preferably, the solvent is toluene.

[0074] Preferably, the contact modification conditions include a temperature of 100-140℃ and a time of 8-40h; more preferably, the contact modification conditions include a temperature of 110-130℃ and a time of 15-30h.

[0075] Preferably, the contact modification further includes the step of drying the contact modified product after solid-liquid separation.

[0076] According to a third aspect of the present invention, the nano-silica can be prepared by a sol-gel method, preferably comprising: mixing 1500-2000 parts by weight of ethanol with 300-600 parts by weight of deionized water and heating to 45-55°C; adding 100 parts by weight of a silicon source (preferably tetraethyl orthosilicate) dropwise over 0.5-5 hours; continuing to mix and stir for 1-5 hours; adding a pH adjuster (preferably an ammonia solution) to adjust the pH value to 8-9; continuing to stir at 45-55°C for 2-8 hours; and then allowing it to stand and age for 10-40 hours to obtain a nano-silica precipitate.

[0077] The precipitated product can be washed 3-5 times by centrifugation with ethanol at a speed of 8000-12000 rpm. Then, the product is vacuum dried at a temperature of 25±5℃ until a constant weight is reached to obtain the nano-silica in powder form.

[0078] In this invention, the particle size of the nano-silica can be 50-300 nm; preferably, the particle size of the nano-silica is 100-200 nm.

[0079] In this invention, the particle size of the nano-silica refers to the longest straight-line distance between two points on the nano-silica.

[0080] According to a third aspect of the present invention, preferably, in step 3), the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica is 1-10 parts by weight relative to 100 parts by weight of the organic solvent; more preferably, the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica is 3-5 parts by weight relative to 100 parts by weight of the organic solvent.

[0081] According to a third aspect of the present invention, preferably, in step 3), the organic solvent is one or more of toluene, xylene, and benzene; more preferably, in step 3), the organic solvent is toluene.

[0082] According to a third aspect of the present invention, preferably, in step 3), based on the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica, the content of the styrene / vinyl acetate copolymer is 90-98% by weight, and the content of the silane coupling agent modified nano-silica is 2-10% by weight; more preferably, based on the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica, the content of the styrene / vinyl acetate copolymer is 90-98% by weight, and the content of the silane coupling agent modified nano-silica is 3-5% by weight.

[0083] According to a third aspect of the present invention, in step 3), the coating can be obtained by mixing a first dispersion containing the styrene / vinyl acetate copolymer with the silane coupling agent-modified nano-silica, or by mixing the styrene / vinyl acetate copolymer with a second dispersion containing the silane coupling agent-modified nano-silica, or by mixing the first dispersion containing the styrene / vinyl acetate copolymer and the second dispersion containing the silane coupling agent-modified nano-silica, or by mixing a mixture of the styrene / vinyl acetate copolymer and the silane coupling agent-modified nano-silica with the organic solvent. Preferably, the coating is obtained by mixing the first dispersion containing the styrene / vinyl acetate copolymer and the second dispersion containing the silane coupling agent-modified nano-silica.

[0084] According to a fourth aspect of the present invention, a coating is provided, wherein the coating is prepared by the method described in the third aspect of the present invention.

[0085] According to a fifth aspect of the present invention, the application of the coating described in the second or fourth aspect of the present invention in the preparation of anti-corrosion articles is provided.

[0086] Examples of corrosion-resistant products include, for instance, oil pipelines coated with the coating of the present invention.

[0087] The present invention will be described in detail below through embodiments, but the present invention is not limited to the following embodiments.

[0088] In the following examples and comparative examples, "parts" means "parts by weight".

[0089] Preparation Example 1 In an apparatus equipped with a condenser, mechanical stirrer, thermometer, and nitrogen protection device, 800 parts of deionized water, 4 parts of polyoxyethylene (4) lauryl ether, 4 parts of polyethylene oxide (80)-polypropylene oxide (27) block copolymer, and 3 parts of sodium dioctyl succinate sulfonate were added and stirred until homogeneous. Nitrogen gas was then introduced to remove oxygen. The stirring speed was increased to 600 rpm, and 100 parts of a monomer mixture with a styrene / vinyl acetate molar ratio of 30 / 70 were added dropwise over 2 hours to obtain a stable styrene / vinyl acetate nanoemulsion. 10% by weight of ammonium persulfate aqueous solution (2 parts based on ammonium persulfate) was added, the temperature was raised to 65±5℃, the stirring speed was increased to 800 rpm, and the reaction was carried out for 3 hours to complete the polymerization. After polymerization, the mixture was cooled to room temperature, filtered, and the precipitated copolymer was dried in a vacuum oven at 40℃ until a constant weight was reached to obtain styrene / vinyl acetate copolymer A1.

[0090] Preparation Example 2 In an apparatus equipped with a condenser, mechanical stirrer, thermometer, and nitrogen protection device, 800 parts of deionized water, 4 parts of polyoxyethylene (4) lauryl ether, 4 parts of polyethylene oxide (80)-polypropylene oxide (27) block copolymer, and 3 parts of sodium dioctyl succinate sulfonate were added and stirred until homogeneous. Nitrogen gas was then introduced to remove oxygen. The stirring speed was increased to 600 rpm, and 100 parts of a monomer mixture with a styrene / vinyl acetate molar ratio of 45 / 55 were added dropwise over 2 hours to obtain a stable styrene / vinyl acetate nanoemulsion. 10% by weight of ammonium persulfate aqueous solution (2 parts based on ammonium persulfate) was added, the temperature was raised to 65±5℃, the stirring speed was increased to 800 rpm, and the reaction was carried out for 3 hours to complete the polymerization. After polymerization, the mixture was cooled to room temperature, filtered, and the precipitated copolymer was dried in a vacuum oven at 40℃ until a constant weight was reached to obtain styrene / vinyl acetate copolymer A2.

[0091] Preparation Example 3 In an apparatus equipped with a condenser, mechanical stirrer, thermometer, and nitrogen protection device, 800 parts of deionized water, 4 parts of polyoxyethylene (4) lauryl ether, 4 parts of polyethylene oxide (80)-polypropylene oxide (27) block copolymer, and 3 parts of sodium dioctyl succinate sulfonate were added and stirred until homogeneous. Nitrogen gas was then introduced to remove oxygen. The stirring speed was increased to 600 rpm, and 100 parts of a monomer mixture with a styrene / vinyl acetate molar ratio of 60 / 40 were added dropwise over 2 hours to obtain a stable styrene / vinyl acetate nanoemulsion. 10% by weight of ammonium persulfate aqueous solution (2 parts based on ammonium persulfate) was added, the temperature was raised to 65±5℃, the stirring speed was increased to 800 rpm, and the reaction was carried out for 3 hours to complete the polymerization. After polymerization, the mixture was cooled to room temperature, filtered, and the precipitated copolymer was dried in a vacuum oven at 40℃ until a constant weight was reached to obtain styrene / vinyl acetate copolymer A3.

[0092] Preparation Example 4 1) In a jacketed stirred tank, add 1800 parts ethanol and 500 parts deionized water, mix at 800 rpm, heat to 50℃, and add 100 parts tetraethyl orthosilicate dropwise over 1.5 hours. Continue mixing and stirring for 3 hours. Add ammonia solution to adjust the pH to 8.5. Continue stirring the mixture at 50±5℃ for another 4 hours. Then let it stand for 24 hours to obtain nano-silica precipitate. Wash the precipitate with ethanol by centrifugation 3-5 times, then centrifuge at 10000 rpm. Vacuum dry the product at 25±5℃ until a constant weight is reached to obtain a white nano-silica powder.

[0093] 2) Using an ultrasonic instrument at a frequency of 1740kHz and a power of 20W / cm² 2100 parts of nano-silica powder were dispersed in 1750 parts of toluene under high intensity and ultrasonic dispersion for 30 minutes. 90 parts of hexadecyltrimethoxysilane were added to the dispersed nano-silica / toluene solution under vigorous stirring at 2000 rpm and a temperature of 25 ± 2°C. The temperature was then raised to 120°C and maintained for 22 hours. The solution was cooled to 25°C and washed three times with methanol. The washed hydrophobic nano-silica was centrifuged at 10000 rpm for 25 minutes and finally dried under vacuum at 25°C until a constant weight was achieved, yielding modified nano-silica powder B1 with a particle size of 100-200 nm.

[0094] Preparation Example 5 Under vigorous stirring at 2000 rpm and a temperature of 25 ± 2°C, 100 parts of 28% trimethylamine aqueous solution and 90 parts of dodecyltriethoxysilane were added to the nano-silica / toluene solution obtained according to Preparation Example 4. The temperature was raised to 120°C and maintained for 22 hours. The solution was then cooled to 25°C and washed three times with methanol. The washed hydrophobic nano-silica was centrifuged at 10000 rpm for 25 minutes and finally dried in a vacuum dryer at 25°C until a constant weight was achieved, yielding modified nano-silica powder B2.

[0095] Examples 1-3 1) Five parts of styrene / vinyl acetate copolymer A1, A2 and A3 were added to 95 parts of benzene and stirred at 800 rpm for 25 minutes to obtain 5 wt% styrene / vinyl acetate copolymer / benzene solutions A1-a, A2-b and A3-c respectively.

[0096] 2) At a stirring speed of 900 rpm, 5 parts of modified nano silica B1 were stirred and dissolved in 95 parts of benzene to obtain a 5 wt% modified nano silica / benzene dispersion B1-a.

[0097] 3) At 25°C, 3 parts of 5wt% modified nano silica / benzene dispersion B1-a were added to 97 parts of 5wt% styrene / vinyl acetate copolymer / benzene solution A1-a, A2-b, and A3-c, respectively, and stirred at 900 rpm for 15 hours to obtain coatings M1, M2, and M3.

[0098] Examples 4-6 1) Five parts of styrene / vinyl acetate copolymer A1, A2 and A3 were added to 95 parts of benzene and stirred at 800 rpm for 25 minutes to obtain 5 wt% styrene / vinyl acetate copolymer / benzene solutions A1-a, A2-b and A3-c respectively.

[0099] 2) At a stirring speed of 900 rpm, 5 parts of modified nano silica B1 were stirred and dissolved in 95 parts of benzene to obtain a 5 wt% modified nano silica / benzene dispersion B1-a.

[0100] 3) At 25°C, 5 parts of 5wt% modified nano silica / benzene dispersion B1-a were added to 95 parts of 5wt% styrene / vinyl acetate copolymer / benzene solution A1-a, A2-b, and A3-c, respectively, and stirred at 900 rpm for 15 hours to obtain coatings M4, M5, and M6.

[0101] Examples 7-9 The following steps were performed according to Examples 1-3, except that 5 parts of modified nano silica B2 were stirred and dissolved in 95 parts of benzene at a stirring speed of 900 rpm to obtain a 5 wt% modified nano silica / benzene dispersion B2-a. Dispersion B2-a was used in step 3) to obtain coatings M7, M8, and M9, respectively.

[0102] Examples 10-12 The process was carried out according to Examples 4-6, except that 5 parts of modified nano silica B2 were stirred and dissolved in 95 parts of benzene at a stirring speed of 900 rpm to obtain a 5 wt% modified nano silica / benzene dispersion B2-a. Dispersion B2-a was used in step 3) to obtain coatings M10, M11, and M12 respectively.

[0103] Comparative Example 1 At 25°C, 12 parts of 5 wt% modified nano silica / benzene dispersion B1-a were added to 88 parts of 5 wt% styrene / vinyl acetate copolymer / benzene solution A1-a, and stirred at 900 rpm for 15 hours to obtain coating DM1.

[0104] Comparative Example 2 At 25°C, 1 part of 5 wt% modified nano silica / benzene dispersion B1-a was added to 99 parts of 5 wt% styrene / vinyl acetate copolymer / benzene solution A1-a, and stirred at 900 rpm for 15 hours to obtain coating DM2.

[0105] Comparative Example 3 1) Nano-silica powder was obtained according to step 1) of Preparation Example 4.

[0106] 2) At a stirring speed of 900 rpm, 5 parts of the above-mentioned nano silica powder were stirred and dissolved in 95 parts of benzene to obtain a 5 wt% nano silica / benzene dispersion.

[0107] At 25°C, 5 parts of 5 wt% nano silica / benzene dispersion were added to 95 parts of 5 wt% styrene / vinyl acetate copolymer / benzene solution A1-a, and stirred at 900 rpm for 15 hours to obtain coating DM3.

[0108] Test Example 1 The coatings obtained in Examples 1-12 and Comparative Examples 1-3 were used to conduct the following tests, and the results are shown in Table 1.

[0109] 1) Corrosion resistance: The coating’s resistance to acid, alkali and salt water was tested according to GB9274-1988 standard.

[0110] 2) Adhesion: The adhesion of the coating is tested according to GB / T9286-2021 standard.

[0111] 3) Impact resistance: The impact resistance of the coating is determined according to GB / T1732-2020 standard.

[0112] 4) Surface appearance: visual inspection Table 1

[0113] Note: 0 indicates that the cut edges are completely smooth and there is no peeling at the grid edges; 1 indicates that there are small pieces peeling off at the intersection of the cuts, and the actual damage within the gridded area is ≤5%; 2 indicates that the edges and / or intersections of the cut have been peeled off, and the area is greater than 5% to 15%.

[0114] As shown in Table 1, the coating M1-12 using the nanocomposite coating material of the present invention has strong adhesion, strong impact resistance, and excellent anti-corrosion effect.

[0115] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A nanocomposite coating material, characterized in that, The nanocomposite coating material contains 90-98% by weight of styrene / vinyl acetate copolymer and 2-10% by weight of silane coupling agent modified nano-silica.

2. The nanocomposite coating material according to claim 1, wherein, The nanocomposite coating material contains 95-97% by weight of styrene / vinyl acetate copolymer and 3-5% by weight of silane coupling agent modified nano-silica.

3. The nanocomposite coating material according to claim 1, wherein, The styrene / vinyl acetate copolymer contains 30-60 mol% of structural units derived from styrene and 40-70 mol% of structural units derived from vinyl acetate; Preferably, the styrene / vinyl acetate copolymer contains 30-45 mol% of structural units derived from styrene and 55-70 mol% of structural units derived from vinyl acetate.

4. The nanocomposite coating material according to claim 1, wherein, The silane coupling agent in the silane coupling agent modified nano-silica is hexadecyltrimethoxysilane and / or dodecyltriethoxysilane.

5. A coating, characterized in that, The coating contains the nanocomposite coating material as described in any one of claims 1-4 and an organic solvent; Preferably, the amount of the nanocomposite coating material is 1-10 parts by weight relative to 100 parts by weight of the organic solvent; Preferably, the organic solvent is one or more of toluene, xylene, and benzene.

6. A method for preparing a coating, characterized in that, This method Includes the following steps, 1) The step of emulsion polymerization of an emulsion containing an emulsifier and a polymerizing monomer in the presence of an initiator to obtain a styrene / vinyl acetate copolymer; 2) Steps for preparing silane coupling agent-modified nano-silica; 3) The step of mixing the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica in the presence of an organic solvent. The polymer monomer contains styrene and vinyl acetate.

7. The method according to claim 6, wherein, In step 1), the emulsifier is one or more of polyoxyethylene lauryl ether, polyethylene oxide-polypropylene oxide block copolymer, and sodium dialkyl succinate sulfonate; Preferably, the amount of the emulsifier is 1-15 parts by weight, more preferably 10-15 parts by weight, relative to 100 parts by weight of the polymeric monomer.

8. The method according to claim 6, wherein, In step 1), the polymeric monomer is added dropwise to an aqueous solution containing an emulsifier to form the emulsion; Preferably, the amount of water used is 500-1000 parts by weight relative to 100 parts by weight of polymer monomer, more preferably 600-900 parts by weight.

9. The method according to claim 6, wherein, In step 1), the initiator is a persulfate, preferably one or more of ammonium persulfate, sodium persulfate, and potassium persulfate; Preferably, the initiator is used in an amount of 1-5 parts by weight, more preferably 1-3 parts by weight, relative to 100 parts by weight of the polymerizing monomer.

10. The method according to any one of claims 6-9, wherein, In step 1), the conditions for emulsion polymerization include: polymerization temperature of 50-80℃ and polymerization time of 1-5h.

11. The method according to any one of claims 6-9, wherein, In step 2), the silane coupling agent modified nano-silica is obtained by contacting the silane coupling agent with nano-silica in the presence of a solvent. Preferably, the silane coupling agent is hexadecyltrimethoxysilane and / or dodecyltriethoxysilane.

12. The method according to claim 11, wherein, The amount of the silane coupling agent relative to 100 parts by weight of the nano-silica is 50-120 parts by weight, preferably 80-100 parts by weight. Preferably, the amount of solvent used is 1500-4500 parts by weight, more preferably 1700-2000 parts by weight, relative to 100 parts by weight of the nano-silica. Preferably, the solvent is one or more of toluene, xylene, and benzene.

13. The method according to any one of claims 6-9, wherein, In step 3), the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica is 1-10 parts by weight relative to 100 parts by weight of the organic solvent. Preferably, the organic solvent is one or more of toluene, xylene, and benzene.

14. The method according to any one of claims 6-9, wherein, In step 3), based on the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica, the content of the styrene / vinyl acetate copolymer is 90-98% by weight, and the content of the silane coupling agent modified nano-silica is 2-10% by weight. Preferably, based on the total weight of the styrene / vinyl acetate copolymer and the silane coupling agent modified nano-silica, the content of the styrene / vinyl acetate copolymer is 95-97% by weight, and the content of the silane coupling agent modified nano-silica is 3-5% by weight.

15. The method according to claim 13 or 14, wherein, The coating is obtained by mixing a first dispersion containing the styrene / vinyl acetate copolymer and a second dispersion containing the silane coupling agent-modified nano-silica.

16. A coating, characterized in that, It is prepared by the method described in any one of claims 6-15.

17. The use of the coating of claim 5 or claim 16 in the preparation of anti-corrosion articles.

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