An aqueous coating based on a modified acrylic resin and a preparation method thereof

Abstract

The present invention relates to the field of coating preparation, and particularly to a waterborne coating based on a modified acrylic resin and a preparation method thereof. In the present invention, a core-shell acrylate and a waterborne acrylic resin are mixed as a base emulsion. On the one hand, the core-shell acrylate can increase the uniform dispersion inside the system, and at the same time can improve the damping performance and corrosion resistance of the waterborne coating. In addition, by introducing an acrylic polymer with a four-layer core-shell structure as a crosslinking agent into the system, the multi-layer core-shell structure can toughen and modify the waterborne acrylic resin, and the various aromatic ring rigid structures contained therein can effectively improve the tensile strength, impact resistance and hardness of the waterborne coating. In addition, it can make the waterborne coating have high flame retardancy, and further interact with the base emulsion, enhancing the damping performance and further improving the corrosion resistance at the same time.

Description

Technical Field

[0001] The present invention relates to the field of coating preparation, and particularly to an aqueous coating based on a modified acrylic resin and a preparation method thereof. Background Art

[0002] With the rapid development of technology and the continuous improvement of living standards, people's awareness of environmental protection has been increasing day by day. This has gradually attracted people's attention and emphasis on material safety issues, and at the same time, the performance requirements for coatings have become higher and higher. Traditional solvent-based coatings are mainly composed of fillers, binders, organic solvents, and additives. During production and use, a large amount of volatile organic compounds will be released. These compounds will not only pollute the environment but may also pose a hazard to human health. Aqueous coatings use water as a solvent or a dispersion medium. In addition to having excellent properties of solvent-based coatings, they also have the advantages of being easy to use, non-toxic, and having no environmental pollution. They are widely used in industries such as buildings, industrial products, automobiles, and packaging printing. However, aqueous coatings often fail to meet the requirements in terms of high temperature resistance, corrosion resistance, and flame retardancy.

[0003] Organosilicon has the advantages of good insulation, corrosion resistance, high temperature resistance, flame retardancy, and easy processing. It is an ideal modifier for improving the performance of aqueous coatings. By introducing organosilicon, the comprehensive performance of aqueous coatings can be significantly enhanced to meet the application requirements in a wider range of fields. However, the current organosilicon-modified aqueous coatings have the disadvantages of poor adhesion and wear resistance. If the adhesion of the coating is insufficient, the coating is likely to peel or crack, which not only affects the aesthetics of the coating but may also cause the coating to lose its effective protection of the substrate. In addition, when the coating is subjected to friction or external forces, problems such as wear and peeling are likely to occur, which may cause the coating to become mottled and uneven, lose its original luster, increase the maintenance cost, and shorten its service life.

[0004] The patent with the publication number CN109504267B discloses an organosilicon-modified aqueous composite wood coating, its preparation method and application. A chemical modification method is used to introduce organosilicon into polyacrylate and aqueous polyurethane, so that the active siloxane groups in its structure hydrolyze to form silanols under certain conditions, and the silanols can dehydrate and condense to form a three-dimensional network cross-linked structure, thereby increasing the cross-linking density of the polymer. The coating prepared by this invention has the advantages of good hardness and heat resistance, but the damping performance and corrosion resistance of the aqueous coating prepared by this method are poor.

[0005] Therefore, according to the above related technologies, it is urgent to develop an aqueous coating based on a modified acrylic resin and a preparation method thereof. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a waterborne coating based on modified acrylic resin and its preparation method, so as to solve the problem of poor corrosion resistance of acrylic resin waterborne coatings in the prior art.

[0007] Based on the above object, the present invention provides a waterborne coating based on modified acrylic resin and its preparation method.

[0008] A waterborne coating based on modified acrylic resin, comprising the following raw materials in parts by mass: 100 - 105 parts of basic emulsion, 8 - 12 parts of crosslinking agent, 0.5 - 0.8 part of triethanolamine, 0.4 - 0.8 part of defoaming agent, 0.3 - 0.6 part of wetting and dispersing agent;

[0009] The basic emulsion is obtained by mixing waterborne acrylic resin and core - shell acrylate in a mass ratio of 80 - 85:15 - 20;

[0010] The crosslinking agent has a four - layer core - shell structure, and the four - layer core - shell structure is prepared from core layer emulsion, inner layer emulsion, intermediate layer emulsion and outer layer emulsion;

[0011] The core layer emulsion is prepared from modified silica;

[0012] The inner layer emulsion is prepared from methyl methacrylate and styrene;

[0013] The intermediate layer emulsion is prepared from butyl acrylate, methyl methacrylate and modified graphene;

[0014] The outer layer emulsion is prepared from butyl acrylate, methyl methacrylate and styrene;

[0015] The modified graphene is amino - functionalized graphene oxide.

[0016] Preferably, the preparation process of the basic emulsion is as follows:

[0017] Step A1. Mix methyl methacrylate, styrene, crosslinking agent and deionized water evenly, add emulsifier, pre - emulsify at 280 - 300 r / min at 70 - 75 °C for 28 - 32 min, then add initiator and react for 150 - 160 min to obtain mixture A;

[0018] Step A2. Mix butyl acrylate and isooctyl acrylate evenly, add initiator and mix evenly to obtain mixture B;

[0019] Step A3. Drop mixture A into mixture B at a flow rate of 1.8 - 2.2 r / min, and continue to react for 150 - 160 min after dropping to obtain core - shell acrylate.

[0020] Preferably, the dosage ratio of methyl methacrylate, styrene, crosslinking agent, deionized water, emulsifier and initiator in step A1 is 6-9 g: 6-9 g: 0.15-0.45 g: 40-50 mL: 0.11-0.16 g: 0.08-0.12 g;

[0021] The crosslinking agent described in step A1 is divinylbenzene;

[0022] The emulsifier described in step A1 is any one of an anionic emulsifier and a nonionic emulsifier;

[0023] The anionic emulsifier is sodium dodecyl sulfonate, and the nonionic emulsifier is OP-10;

[0024] The initiator described in step A1 is ammonium persulfate.

[0025] Preferably, the dosage ratio of butyl acrylate, octyl acrylate and initiator in step A2 is 26-31 g: 4-7 g: 0.35-1.05 g;

[0026] The initiator described in step A2 is ammonium persulfate;

[0027] The mass ratio of the mixed solution A and the mixed solution B in step A3 is 28-32: 68-72.

[0028] Preferably, the preparation process of the crosslinking agent is as follows:

[0029] Step B1. Add nano-silica into an ethanol aqueous solution, add KH570 after dispersing evenly, then dropwise add oxalic acid to adjust the pH to 4, react at 68-72 °C for 110-120 min, filter, and wash with ethanol to obtain modified silica;

[0030] Step B2. Add the modified silica, butyl acrylate, styrene and crosslinking agent into deionized water, add an emulsifier, pre-emulsify at 65-70 °C for 30-35 min under nitrogen protection to obtain a pre-emulsion, then add an initiator, and react at a stirring speed of 280-300 r / min for 150-160 min to obtain an inner layer emulsion;

[0031] Step B3. Add an initiator into the inner layer emulsion, and dropwise add butyl acrylate, methyl methacrylate and crosslinking agent into it with a peristaltic pump, the flow rate of the peristaltic pump is 1.8-2.2 r / min, and continue the polymerization reaction for 150-160 min after the dropping is completed to obtain an intermediate layer pre-emulsion;

[0032] Step B4. Disperse graphene oxide in deionized water to obtain a graphene oxide dispersion. Then, add a silane coupling agent to absolute ethanol and ultrasonically disperse it for 5 - 7 min to obtain a silane coupling agent dispersion. Ultrasonically mix the graphene oxide dispersion and the silane coupling agent dispersion evenly, and react in an oil bath at 78 - 86 °C for 6 - 8 h. Centrifuge and reserve to obtain functionalized graphene;

[0033] Step B5. Adjust the pH of the intermediate pre-emulsion to 8 - 9, add functionalized graphene, and ultrasonically disperse it for 30 - 50 min to obtain an intermediate emulsion;

[0034] Step B6. Add an initiator to the intermediate emulsion and use a peristaltic pump to dropwise add butyl acrylate, methyl methacrylate, styrene, and 2-hydroxyethyl methacrylate. The flow rate of the peristaltic pump is 1.8 - 2.2 r / min. After the dropping is completed, continue the polymerization reaction for 150 - 160 min to obtain a crosslinking agent.

[0035] Preferably, the dosage ratio of the nano-silica, ethanol aqueous solution, and KH570 in Step B1 is 0.3 - 0.6 g : 10 - 14 mL : 0.035 - 0.045 g;

[0036] The volume fraction of the ethanol aqueous solution in Step B1 is 78% - 82%;

[0037] The dosage ratio of the modified silica, butyl acrylate, styrene, crosslinking agent, deionized water, emulsifier, and initiator in Step B2 is 1.5 - 2 g : 1.2 - 4.2 g : 10.11 - 13.8 g : 0.6 - 0.9 g : 36 - 42 mL : 0.4 - 0.7 g : 0.5 - 0.8 g;

[0038] The crosslinking agent in Step B2 is divinylbenzene;

[0039] The emulsifier in Step B2 is obtained by mixing an anionic emulsifier and a non-ionic emulsifier in a mass ratio of 0.2 - 0.4 : 0.2 - 0.3;

[0040] The anionic emulsifier in Step B2 is sodium dodecyl sulfate, and the non-ionic emulsifier is OP-10;

[0041] The initiator in Step B2 is ammonium persulfate.

[0042] Preferably, the dosage ratio of the inner layer emulsion, initiator, butyl acrylate, methyl methacrylate, and crosslinking agent in Step B3 is 40 - 42 mL : 0.2 - 0.4 g : 12 - 14 g : 15.3 - 18 g : 0.4 - 0.7 g;

[0043] The initiator in Step B3 is ammonium persulfate;

[0044] The crosslinking agent described in step B3 is divinylbenzene.

[0045] Preferably, the dosage ratio of graphene oxide to deionized water described in step B4 is 3 - 6 g: 100 - 105 mL;

[0046] The dosage ratio of silane coupling agent to absolute ethanol described in step B4 is 5 - 9 g: 80 - 85 mL;

[0047] The volume ratio of graphene oxide dispersion to silane coupling agent dispersion described in step B4 is 100 - 105: 80 - 85;

[0048] The silane coupling agent described in step B4 is KH - 550.

[0049] Preferably, the dosage ratio of the intermediate layer pre - emulsion to functionalized graphene described in step B5 is 38 - 42 mL: 0.1 - 0.2 g;

[0050] The dosage ratio of the intermediate layer emulsion, initiator, butyl acrylate, methyl methacrylate, styrene, and 2 - hydroxyethyl methacrylate described in step B6 is 40 - 42 mL: 0.3 - 0.6 g: 16 - 23 g: 5 - 9 g: 5 - 7 g: 0.45 - 1.35 g;

[0051] The initiator described in step B6 is ammonium persulfate.

[0052] A preparation method of a water - borne coating based on modified acrylic resin, comprising the following steps:

[0053] Mix the base emulsion, crosslinking agent, triethanolamine, defoamer, and wetting dispersant evenly to obtain a water - borne coating based on modified acrylic resin.

[0054] The beneficial effects of the present invention:

[0055] The present invention provides a water - borne coating based on modified acrylic resin and its preparation method. In the present invention, the core - shell acrylate and water - borne acrylic resin are mixed as the base emulsion. On the one hand, the core - shell acrylate can increase the uniform dispersion inside the system, and at the same time, it can improve the damping performance and corrosion resistance of the water - borne coating.

[0056] The present invention provides an aqueous coating based on a modified acrylic resin and a preparation method thereof. In the present invention, an acrylic polymer having a four-layer core-shell structure is introduced into the system as a cross-linking agent. The multi-layer core-shell structure therein can toughen and modify the aqueous acrylic resin, and it can be uniformly dispersed in the system. In addition, a variety of aromatic ring rigid structures contained therein can effectively improve the tensile strength, impact resistance and hardness of the aqueous coating. Moreover, it can endow the aqueous coating with high flame retardancy, and further interact with the base emulsion to enhance the damping performance and further improve the corrosion resistance. Detailed implementation manners

[0057] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments.

[0058] The sources and properties of some raw materials used in the present invention are as follows:

[0059] The solid content of the aqueous acrylic resin is 45%, and the model is CFW905F;

[0060] The brand of the defoaming agent is Efka SI 2741;

[0061] The brand of the wetting and dispersing agent is AFCONA-5207.

[0062] Example 1: A preparation method of an aqueous coating based on a modified acrylic resin, comprising the following steps:

[0063] S1. Mix 6 g of methyl methacrylate, 6 g of styrene, 0.15 g of divinylbenzene and 40 mL of deionized water evenly, add 0.11 g of sodium dodecylsulfonate, pre-emulsify at 70 °C for 28 min at a rotation speed of 280 r / min, and then add 0.08 g of ammonium persulfate and react for 150 min to obtain a mixed solution A;

[0064] S2. Mix 26 g of butyl acrylate and 4 g of isooctyl acrylate evenly, add 0.35 g of ammonium persulfate and mix evenly to obtain a mixed solution B;

[0065] S3. Drop 28 g of the mixed solution A into 68 g of the mixed solution B at a flow rate of 1.8 r / min. After the dropping is completed, continue to react for 150 min to obtain a core-shell acrylate;

[0066] S4. Mix 80 g of the aqueous acrylic resin and 15 g of the core-shell acrylate evenly to obtain a base emulsion;

[0067] S5. Add 0.3 g of nano-silica into 10 mL of ethanol aqueous solution with a volume fraction of 78%, after dispersing evenly, add 0.035 g of KH570, then dropwise add oxalic acid to adjust the pH to 4, react at 68 °C for 110 min, filter, and wash with ethanol to obtain modified silica;

[0068] S6. Mix 0.2 g of sodium dodecyl sulfonate and 0.2 g of OP-10 evenly to obtain an emulsifier;

[0069] S7. Add 1.5 g of modified silica, 1.2 g of butyl acrylate, 10.11 g of styrene and 0.6 g of divinylbenzene into 36 mL of deionized water, add 0.4 g of emulsifier, pre-emulsify at 65 °C for 30 min under nitrogen protection to obtain a pre-emulsion, then add 0.5 g of ammonium persulfate, and react at a stirring speed of 280 r / min for 150 min to obtain an inner layer emulsion;

[0070] S8. Add 0.2 g of ammonium persulfate to 40 mL of the inner layer emulsion, and drop 12 g of butyl acrylate, 15.3 g of methyl methacrylate and 0.4 g of divinylbenzene into it with a peristaltic pump, the flow rate of the peristaltic pump is 1.8 r / min, after dropping, continue the polymerization reaction for 150 min to obtain an intermediate layer pre-emulsion;

[0071] S9. Disperse 3 g of graphene oxide in 100 mL of deionized water to obtain a graphene oxide dispersion, then add 5 g of KH-550 into 80 mL of absolute ethanol, ultrasonically disperse evenly for 5 min to obtain a silane coupling agent dispersion, ultrasonically mix 100 mL of graphene oxide dispersion and 80 mL of silane coupling agent dispersion evenly, react in an oil bath at 78 °C for 6 h, centrifuge and reserve to obtain functionalized graphene;

[0072] S10. Adjust the pH of 38 mL of the intermediate layer pre-emulsion to 8, add 0.1 g of functionalized graphene, and ultrasonically treat for 30 min to obtain an intermediate layer emulsion;

[0073] S11. Add 0.3 g of ammonium persulfate to 40 mL of the intermediate layer emulsion and drop 16 g of butyl acrylate, 5 g of methyl methacrylate, 5 g of styrene and 0.45 g of 2-hydroxyethyl methacrylate with a peristaltic pump, the flow rate of the peristaltic pump is 1.8 r / min, after dropping, continue the polymerization reaction for 150 min to obtain a crosslinking agent;

[0074] S12. Mix 80 g of waterborne acrylic resin and 15 g of core-shell acrylate evenly to obtain a base emulsion;

[0075] S13. Mix 100 g of the base emulsion, 8 g of the crosslinking agent, 0.5 g of triethanolamine, 0.4 g of defoamer, and 0.3 g of wetting dispersant evenly to obtain a waterborne coating based on modified acrylic resin.

[0076] Example 2: A preparation method of an aqueous coating based on a modified acrylic resin, comprising the following steps:

[0077] S1. Mix 6.6 g of methyl methacrylate, 6.6 g of styrene, 0.25 g of divinylbenzene and 42 mL of deionized water evenly, add 0.12 g of OP-10, pre-emulsify at 71 °C for 29 min at a rotation speed of 285 r / min, then add 0.09 g of ammonium persulfate, and react for 152 min to obtain a mixed solution A;

[0078] S2. Mix 27 g of butyl acrylate and 5 g of isooctyl acrylate evenly, add 0.5 g of ammonium persulfate, and mix evenly to obtain a mixed solution B;

[0079] S3. Drop 29 g of the mixed solution A into 69 g of the mixed solution B at a flow rate of 1.9 r / min. After the dropping is completed, continue to react for 152 min to obtain a core-shell acrylate;

[0080] S4. Mix 81 g of an aqueous acrylic resin and 16 g of the core-shell acrylate evenly to obtain a base emulsion;

[0081] S5. Add 0.4 g of nano-silica to 11 mL of an ethanol aqueous solution with a volume fraction of 79%, disperse evenly, add 0.038 g of KH570, then dropwise add oxalic acid to adjust the pH to 4, react at 69 °C for 112 min, filter, and wash with ethanol to obtain modified silica;

[0082] S6. Mix 0.3 g of sodium dodecyl sulfate and 0.22 g of OP-10 evenly to obtain an emulsifier;

[0083] S7. Add 1.6 g of modified silica, 2 g of butyl acrylate, 11 g of styrene and 0.7 g of divinylbenzene to 37 mL of deionized water, add 0.5 g of the emulsifier, pre-emulsify at 66 °C for 31 min under nitrogen protection to obtain a pre-emulsion, then add 0.6 g of ammonium persulfate, and react at a stirring speed of 284 r / min for 152 min to obtain an inner layer emulsion;

[0084] S8. Add 0.3 g of ammonium persulfate to 41 mL of the inner layer emulsion, and drop 13 g of butyl acrylate, 16 g of methyl methacrylate and 0.5 g of divinylbenzene into it with a peristaltic pump. The flow rate of the peristaltic pump is 1.9 r / min. After the dropping is completed, continue the polymerization reaction for 152 min to obtain an intermediate layer pre-emulsion;

[0085] S9. Disperse 4 g of graphene oxide in 101 mL of deionized water to obtain a graphene oxide dispersion. Then, add 6 g of KH-550 to 81 mL of absolute ethanol and ultrasonically disperse it evenly for 6 min to obtain a silane coupling agent dispersion. Ultrasonically mix 101 mL of the graphene oxide dispersion and 81 mL of the silane coupling agent dispersion evenly, and react in an oil bath at 80 °C for 7 h. Centrifuge and reserve to obtain functionalized graphene;

[0086] S10. Adjust the pH of 39 mL of the intermediate layer pre-emulsion to 8.5, add 0.12 g of functionalized graphene, and ultrasonically disperse it for 34 min to obtain an intermediate layer emulsion;

[0087] S11. Add 0.4 g of ammonium persulfate to 41 mL of the intermediate layer emulsion and use a peristaltic pump to dropwise add 18 g of butyl acrylate, 6 g of methyl methacrylate, 6 g of styrene, and 0.6 g of 2-hydroxyethyl methacrylate. The flow rate of the peristaltic pump is 1.9 r / min. After the dropping is completed, continue the polymerization reaction for 152 min to obtain a crosslinking agent;

[0088] S12. Mix 81 g of waterborne acrylic resin and 16 g of core-shell acrylate evenly to obtain a base emulsion;

[0089] S13. Mix 101 g of the base emulsion, 9 g of the crosslinking agent, 0.6 g of triethanolamine, 0.5 g of defoamer, and 0.4 g of wetting and dispersing agent evenly to obtain a waterborne coating based on modified acrylic resin.

[0090] Example 3: A preparation method of a waterborne coating based on modified acrylic resin, comprising the following steps:

[0091] S1. Mix 7 g of methyl methacrylate, 7 g of styrene, 0.3 g of divinylbenzene, and 44 mL of deionized water evenly, add 0.13 g of sodium dodecyl sulfonate, pre-emulsify at 72 °C for 30 min at a rotation speed of 290 r / min, then add 0.1 g of ammonium persulfate, and react for 154 min to obtain a mixed solution A;

[0092] S2. Mix 28 g of butyl acrylate and 6 g of isooctyl acrylate evenly, add 0.6 g of ammonium persulfate, and mix evenly to obtain a mixed solution B;

[0093] S3. Dropwise add 30 g of the mixed solution A to 70 g of the mixed solution B at a flow rate of 2 r / min. After the dropping is completed, continue the reaction for 154 min to obtain a core-shell acrylate;

[0094] S4. Mix 82 g of waterborne acrylic resin and 17 g of core-shell acrylate evenly to obtain a base emulsion;

[0095] S5. Add 0.5 g of nano-silica into 12 mL of ethanol aqueous solution with a volume fraction of 80%. After dispersing evenly, add 0.04 g of KH570, then dropwise add oxalic acid to adjust the pH to 4, react at 70 °C for 114 min, filter, and wash with ethanol to obtain modified silica;

[0096] S6. Mix 0.4 g of sodium dodecyl sulfonate and 0.24 g of OP-10 evenly to obtain an emulsifier;

[0097] S7. Add 1.7 g of modified silica, 2.6 g of butyl acrylate, 12 g of styrene, and 0.8 g of divinylbenzene into 38 mL of deionized water, add 0.6 g of emulsifier, pre-emulsify at 67 °C for 32 min under nitrogen protection to obtain a pre-emulsion, then add 0.7 g of ammonium persulfate and react at a stirring speed of 288 r / min for 154 min to obtain an inner layer emulsion;

[0098] S8. Add 0.4 g of ammonium persulfate to 42 mL of the inner layer emulsion, and drop 14 g of butyl acrylate, 16.5 g of methyl methacrylate, and 0.6 g of divinylbenzene into it with a peristaltic pump at a flow rate of 2 r / min. After the dropping is completed, continue the polymerization reaction for 154 min to obtain an intermediate layer pre-emulsion;

[0099] S9. Disperse 5 g of graphene oxide in 102 mL of deionized water to obtain a graphene oxide dispersion. Then add 7 g of KH-550 to 82 mL of absolute ethanol, ultrasonically disperse evenly for 7 min to obtain a silane coupling agent dispersion. Ultrasonically mix 102 mL of the graphene oxide dispersion and 82 mL of the silane coupling agent dispersion evenly, react in an 82 °C oil bath for 8 h, centrifuge and reserve to obtain functionalized graphene;

[0100] S10. Adjust the pH of 40 mL of the intermediate layer pre-emulsion to 9, add 0.14 g of functionalized graphene, and ultrasonically treat for 38 min to obtain an intermediate layer emulsion;

[0101] S11. Add 0.5 g of ammonium persulfate to 42 mL of the intermediate layer emulsion and drop 20 g of butyl acrylate, 7 g of methyl methacrylate, 7 g of styrene, and 0.75 g of 2-hydroxyethyl methacrylate into it with a peristaltic pump at a flow rate of 2.1 r / min. After the dropping is completed, continue the polymerization reaction for 154 min to obtain a crosslinking agent;

[0102] S12. Mix 82 g of waterborne acrylic resin and 17 g of core-shell acrylate evenly to obtain a base emulsion;

[0103] S13. Mix 102 g of the base emulsion, 10 g of the crosslinking agent, 0.7 g of triethanolamine, 0.6 g of defoamer, and 0.5 g of wetting dispersant evenly to obtain a waterborne coating based on modified acrylic resin.

[0104] Example 4: A preparation method of an aqueous coating based on a modified acrylic resin, comprising the following steps:

[0105] S1. Mix 8 g of methyl methacrylate, 8 g of styrene, 0.35 g of divinylbenzene and 46 mL of deionized water evenly, add 0.14 g of OP-10, pre-emulsify at 73 °C for 31 min at a rotation speed of 295 r / min, then add 0.11 g of ammonium persulfate, and react for 156 min to obtain a mixed solution A;

[0106] S2. Mix 29 g of butyl acrylate and 5 g of isooctyl acrylate evenly, add 0.8 g of ammonium persulfate, and mix evenly to obtain a mixed solution B;

[0107] S3. Drop 31 g of the mixed solution A into 71 g of the mixed solution B at a flow rate of 2.1 r / min. After the dropping is completed, continue to react for 156 min to obtain a core-shell acrylate;

[0108] S4. Mix 83 g of an aqueous acrylic resin and 18 g of the core-shell acrylate evenly to obtain a base emulsion;

[0109] S5. Add 0.4 g of nano-silica to 12 mL of an ethanol aqueous solution with a volume fraction of 81%, disperse evenly, add 0.042 g of KH570, then dropwise add oxalic acid to adjust the pH to 4, react at 71 °C for 116 min, filter, and wash with ethanol to obtain modified silica;

[0110] S6. Mix 0.2 g of sodium dodecyl sulfate and 0.26 g of OP-10 evenly to obtain an emulsifier;

[0111] S7. Add 1.8 g of modified silica, 3 g of butyl acrylate, 12.5 g of styrene and 0.8 g of divinylbenzene to 39 mL of deionized water, add 0.7 g of the emulsifier, pre-emulsify at 68 °C for 33 min under nitrogen protection to obtain a pre-emulsion, then add 0.8 g of ammonium persulfate, and react at a stirring speed of 292 r / min for 154 min to obtain an inner layer emulsion;

[0112] S8. Add 0.2 g of ammonium persulfate to 40 mL of the inner layer emulsion, and drop 12 g of butyl acrylate, 17 g of methyl methacrylate and 0.7 g of divinylbenzene into it with a peristaltic pump. The flow rate of the peristaltic pump is 2.1 r / min. After the dropping is completed, continue the polymerization reaction for 156 min to obtain an intermediate layer pre-emulsion;

[0113] S9. Disperse 6 g of graphene oxide in 103 mL of deionized water to obtain a graphene oxide dispersion. Then add 8 g of KH-550 to 83 mL of absolute ethanol, and ultrasonically disperse it evenly for 5 min to obtain a silane coupling agent dispersion. Ultrasonically mix 103 mL of the graphene oxide dispersion and 83 mL of the silane coupling agent dispersion evenly, react in an oil bath at 83 °C for 6 h, centrifuge and reserve to obtain functionalized graphene;

[0114] S10. Adjust the pH of 41 mL of the intermediate pre-emulsion to 8, add 0.16 g of functionalized graphene, and ultrasonically disperse it for 42 min to obtain an intermediate emulsion;

[0115] S11. Add 0.5 g of ammonium persulfate to 40 mL of the intermediate emulsion, and use a peristaltic pump to dropwise add 21 g of butyl acrylate, 8 g of methyl methacrylate, 5 g of styrene, and 0.9 g of 2-hydroxyethyl methacrylate. The flow rate of the peristaltic pump is 2.1 r / min. After the dropping is completed, continue the polymerization reaction for 156 min to obtain a crosslinking agent;

[0116] S12. Mix 83 g of waterborne acrylic resin and 18 g of core-shell acrylate evenly to obtain a base emulsion;

[0117] S13. Mix 103 g of the base emulsion, 11 g of the crosslinking agent, 0.8 g of triethanolamine, 0.7 g of defoamer, and 0.6 g of wetting and dispersing agent evenly to obtain a waterborne coating based on modified acrylic resin.

[0118] Example 5: A preparation method of a waterborne coating based on modified acrylic resin, comprising the following steps:

[0119] S1. Mix 8.8 g of methyl methacrylate, 8.8 g of styrene, 0.4 g of divinylbenzene and 48 mL of deionized water evenly, add 0.15 g of sodium dodecyl sulfonate, pre-emulsify at 74 °C for 31.5 min at a rotation speed of 298 r / min, then add 0.11 g of ammonium persulfate, and react for 158 min to obtain a mixed solution A;

[0120] S2. Mix 30 g of butyl acrylate and 6 g of isooctyl acrylate evenly, add 1 g of ammonium persulfate, and mix evenly to obtain a mixed solution B;

[0121] S3. Dropwise add 31 g of the mixed solution A to 71 g of the mixed solution B at a flow rate of 2.1 r / min. After the dropping is completed, continue the reaction for 158 min to obtain a core-shell acrylate;

[0122] S4. Mix 84 g of waterborne acrylic resin and 19 g of core-shell acrylate evenly to obtain a base emulsion;

[0123] S5. Add 0.5 g of nano-silica into 13 mL of ethanol aqueous solution with a volume fraction of 80%. After dispersing evenly, add 0.043 g of KH570, then dropwise add oxalic acid to adjust the pH to 4, react at 69 °C for 118 min, filter, and wash with ethanol to obtain modified silica;

[0124] S6. Mix 0.3 g of sodium dodecyl sulfonate and 0.28 g of OP-10 evenly to obtain an emulsifier;

[0125] S7. Add 1.9 g of modified silica, 3.6 g of butyl acrylate, 13 g of styrene, and 0.7 g of divinylbenzene into 40 mL of deionized water, add 0.6 g of emulsifier, pre-emulsify at 69 °C for 34 min under nitrogen protection to obtain a pre-emulsion, then add 0.7 g of ammonium persulfate and react at a stirring speed of 296 r / min for 156 min to obtain an inner layer emulsion;

[0126] S8. Add 0.3 g of ammonium persulfate into 41 mL of the inner layer emulsion, and drop 13 g of butyl acrylate, 17.6 g of methyl methacrylate, and 0.6 g of divinylbenzene into it with a peristaltic pump at a flow rate of 2 r / min. After dropping, continue the polymerization reaction for 158 min to obtain an intermediate layer pre-emulsion;

[0127] S9. Disperse 5 g of graphene oxide in 104 mL of deionized water to obtain a graphene oxide dispersion. Then add 8 g of KH-550 into 84 mL of absolute ethanol, disperse evenly by ultrasonic for 6 min to obtain a silane coupling agent dispersion. Ultrasonically mix 104 mL of graphene oxide dispersion and 84 mL of silane coupling agent dispersion evenly, react in an oil bath at 85 °C for 7 h, centrifuge and reserve to obtain functionalized graphene;

[0128] S10. Adjust the pH of 42 mL of the intermediate layer pre-emulsion to 8.5, add 0.18 g of functionalized graphene, and ultrasonically treat for 46 min to obtain an intermediate layer emulsion;

[0129] S11. Add 0.4 g of ammonium persulfate into 41 mL of the intermediate layer emulsion and drop 22 g of butyl acrylate, 7 g of methyl methacrylate, 6 g of styrene, and 1.2 g of 2-hydroxyethyl methacrylate into it with a peristaltic pump at a flow rate of 2 r / min. After dropping, continue the polymerization reaction for 158 min to obtain a crosslinking agent;

[0130] S12. Mix 84 g of waterborne acrylic resin and 19 g of core-shell acrylate evenly to obtain a basic emulsion;

[0131] S13. Mix 104 g of the basic emulsion, 11 g of the crosslinking agent, 0.7 g of triethanolamine, 0.6 g of defoamer, and 0.5 g of wetting dispersant evenly to obtain a waterborne coating based on modified acrylic resin.

[0132] Example 6: A preparation method of an aqueous coating based on a modified acrylic resin, comprising the following steps:

[0133] S1. Mix 9 g of methyl methacrylate, 9 g of styrene, 0.45 g of divinylbenzene and 50 mL of deionized water evenly, add 0.16 g of OP-10, pre-emulsify at 75 °C for 32 min at a rotation speed of 300 r / min, then add 0.12 g of ammonium persulfate, and react for 160 min to obtain a mixed solution A;

[0134] S2. Mix 31 g of butyl acrylate and 7 g of isooctyl acrylate evenly, add 1.05 g of ammonium persulfate, and mix evenly to obtain a mixed solution B;

[0135] S3. Drop 32 g of the mixed solution A into 72 g of the mixed solution B at a flow rate of 2.2 r / min. After the dropping is completed, continue to react for 160 min to obtain a core-shell acrylate;

[0136] S4. Mix 85 g of an aqueous acrylic resin and 20 g of the core-shell acrylate evenly to obtain a base emulsion;

[0137] S5. Add 0.6 g of nano-silica to 14 mL of an ethanol aqueous solution with a volume fraction of 82%, disperse evenly, add 0.045 g of KH570, then dropwise add oxalic acid to adjust the pH to 4, react at 72 °C for 120 min, filter, and wash with ethanol to obtain modified silica;

[0138] S6. Mix 0.4 g of sodium dodecyl sulfonate and 0.3 g of OP-10 evenly to obtain an emulsifier;

[0139] S7. Add 2 g of modified silica, 4.2 g of butyl acrylate, 13.8 g of styrene and 0.9 g of divinylbenzene to 42 mL of deionized water, add 0.5 g of the emulsifier, pre-emulsify at 70 °C for 35 min under nitrogen protection to obtain a pre-emulsion, then add 0.8 g of ammonium persulfate, and react at a stirring speed of 300 r / min for 160 min to obtain an inner layer emulsion;

[0140] S8. Add 0.4 g of ammonium persulfate to 42 mL of the inner layer emulsion, and drop 14 g of butyl acrylate, 18 g of methyl methacrylate and 0.7 g of divinylbenzene into it with a peristaltic pump. The flow rate of the peristaltic pump is 2.2 r / min. After the dropping is completed, continue the polymerization reaction for 160 min to obtain an intermediate layer pre-emulsion;

[0141] S9. Disperse 6 g of graphene oxide in 105 mL of deionized water to obtain a graphene oxide dispersion. Then add 9 g of KH-550 to 85 mL of absolute ethanol, and ultrasonically disperse it evenly for 7 min to obtain a silane coupling agent dispersion. Ultrasonically mix 105 mL of the graphene oxide dispersion and 85 mL of the silane coupling agent dispersion evenly, and react in an oil bath at 86 °C for 8 h. Centrifuge for standby to obtain functionalized graphene;

[0142] S10. Adjust the pH of 42 mL of the intermediate pre-emulsion to 9, add 0.2 g of functionalized graphene, and ultrasonically disperse for 50 min to obtain an intermediate emulsion;

[0143] S11. Add 0.6 g of ammonium persulfate to 42 mL of the intermediate emulsion, and use a peristaltic pump to dropwise add 23 g of butyl acrylate, 9 g of methyl methacrylate, 7 g of styrene, and 1.35 g of 2-hydroxyethyl methacrylate. The flow rate of the peristaltic pump is 2.2 r / min. After the dropping is completed, continue the polymerization reaction for 160 min to obtain a crosslinking agent;

[0144] S12. Mix 85 g of waterborne acrylic resin and 20 g of core-shell acrylate evenly to obtain a base emulsion;

[0145] S13. Mix 105 g of the base emulsion, 12 g of the crosslinking agent, 0.8 g of triethanolamine, 0.8 g of defoamer, and 0.6 g of wetting and dispersing agent evenly to obtain a waterborne coating based on modified acrylic resin.

[0146] Comparative Example 1:

[0147] Compared with Example 1, this comparative example did not add core-shell acrylate during the preparation of the base emulsion, and the remaining steps and parameters were the same. This comparative example will not be repeated here. Finally, a waterborne coating based on modified acrylic resin was obtained.

[0148] Comparative Example 2:

[0149] Compared with Example 1, this comparative example only increased the dosage of core-shell acrylate from "15 g" to "80 g", and the remaining steps and parameters were the same. This comparative example will not be repeated here. Finally, a waterborne coating based on modified acrylic resin was obtained.

[0150] Comparative Example 3:

[0151] Compared with Example 1, this comparative example did not add modified silica during the preparation of the waterborne coating based on modified acrylic resin, and the remaining steps and parameters were the same. This comparative example will not be repeated here. Finally, a waterborne coating based on modified acrylic resin was obtained.

[0152] Comparative Example 4:

[0153] This comparative example is the same as Example 1 in all steps and parameters except that functionalized graphene was not added during the preparation of the waterborne coating based on the modified acrylic resin. Therefore, this comparative example will not be repeated here, and finally, a waterborne coating based on the modified acrylic resin was obtained.

[0154] Comparative Example 5:

[0155] S1. Mix 6 g of methyl methacrylate, 6 g of styrene, 0.15 g of divinylbenzene, and 40 mL of deionized water evenly. Add 0.11 g of sodium dodecyl sulfonate and pre-emulsify at 70 °C for 28 min at a rotation speed of 280 r / min. Then add 0.08 g of ammonium persulfate and react for 150 min to obtain a mixed solution A.

[0156] S2. Mix 26 g of butyl acrylate and 4 g of isooctyl acrylate evenly. Add 0.35 g of ammonium persulfate and mix evenly to obtain a mixed solution B.

[0157] S3. Drop 28 g of the mixed solution A into 68 g of the mixed solution B at a flow rate of 1.8 r / min. After the dropping is completed, continue to react for 150 min to obtain a core-shell acrylate.

[0158] S4. Mix 80 g of the waterborne acrylic resin and 15 g of the core-shell acrylate evenly to obtain a basic emulsion.

[0159] S5. Add 0.3 g of nano-silica to 10 mL of an ethanol aqueous solution with a volume fraction of 78%. After dispersing evenly, add 0.035 g of KH570, then dropwise add oxalic acid to adjust the pH to 4, react at 68 °C for 110 min, filter, and wash with ethanol to obtain modified silica.

[0160] S6. Mix 0.2 g of sodium dodecyl sulfonate and 0.2 g of OP-10 evenly to obtain an emulsifier.

[0161] S7. Add 1.5 g of modified silica, 1.2 g of butyl acrylate, 10.11 g of styrene, and 0.6 g of divinylbenzene to 36 mL of deionized water. Add 0.4 g of the emulsifier, pre-emulsify at 65 °C for 30 min under nitrogen protection to obtain a pre-emulsion, then add 0.5 g of ammonium persulfate and react at a stirring speed of 280 r / min for 150 min to obtain an inner layer emulsion.

[0162] S8. Add 0.2 g of ammonium persulfate to 40 mL of the inner layer emulsion, and drop 12 g of butyl acrylate, 15.3 g of methyl methacrylate, and 0.4 g of divinylbenzene into it using a peristaltic pump at a flow rate of 1.8 r / min. After the dropping is completed, continue the polymerization reaction for 150 min to obtain an intermediate layer pre-emulsion.

[0163] S9. Disperse 3 g of graphene oxide in 100 mL of deionized water to obtain a graphene oxide dispersion. Then, add 5 g of KH-550 to 80 mL of absolute ethanol and ultrasonically disperse it evenly for 5 min to obtain a silane coupling agent dispersion. Ultrasonically mix 100 mL of the graphene oxide dispersion and 80 mL of the silane coupling agent dispersion evenly, and react in an oil bath at 78 °C for 6 h. Centrifuge and reserve to obtain functionalized graphene;

[0164] S10. Adjust the pH of 38 mL of the intermediate layer pre-emulsion to 8, add 0.1 g of functionalized graphene, and ultrasonically disperse for 30 min to obtain a crosslinking agent;

[0165] S11. Mix 80 g of waterborne acrylic resin and 15 g of core-shell acrylate evenly to obtain a base emulsion;

[0166] S12. Mix 100 g of the base emulsion, 8 g of the crosslinking agent, 0.5 g of triethanolamine, 0.4 g of defoamer, and 0.3 g of wetting dispersant evenly to obtain a waterborne coating based on modified acrylic resin.

[0167] Performance testing:

[0168] Pour the waterborne coatings prepared in Examples 1 - 6 and Comparative Examples 1 - 5 onto a polytetrafluoroethylene mold and dry at 30 °C for one week to obtain a film;

[0169] Refer to the GB / T 1040.1-2006 standard to test the tensile strength and elongation at break of each group of samples;

[0170] Refer to the GB / T1732-1993 standard to test the impact resistance of each group of samples;

[0171] Refer to the GB / T 6739-2006 standard to test the hardness of each group of samples;

[0172] Refer to the ISO7253 standard to test the salt spray resistance of each group of samples, and record the surface state of each group of samples at 800 h of the salt spray test;

[0173] Use a dynamic mechanical analyzer to test the damping performance of each group of samples, and record the damping temperature range (°C) of each group of samples;

[0174] Apply the waterborne coatings prepared in Examples 1 - 6 and Comparative Examples 1 - 5 on tinplate. After drying, apply an adhesive on the coating surface. Connect the circular forging die of the adhesion tester to the coating surface through the adhesive. After the adhesive dries for 24 h, scrape off the excess coating around the circular forging die. Use the adhesion tester to apply a lifting force to the circular forging die. The value displayed when the circular forging die pulls the coating off the tinplate surface is F max, the area of the circular forging die is S, and the final result is measured three times and averaged. The calculation formula for adhesion is as follows:

[0175]

[0176] The results are shown in Table 1 and Table 2 below:

[0177] Table 1 Summary of experimental results in Examples 1 - 6 and Comparative Examples 1 - 5

[0178]

[0179] Table 2 Summary of experimental results in Examples 1 - 6 and Comparative Examples 1 - 5

[0180]

[0181]

[0182] Data analysis:

[0183] As can be seen from the above Table 1 and Table 2, the waterborne coating based on the modified acrylic resin prepared by the present invention has stronger mechanical properties, higher hardness, stronger adhesion, stronger salt spray resistance and better damping performance;

[0184] This may be because the core - shell acrylate and waterborne acrylic resin provided in the present invention are mixed as the base emulsion. The core - shell acrylate in it increases the uniform dispersion inside the system, making the system relatively stable. At the same time, the presence of a small amount of core - shell acrylate effectively reduces the difficulty of molecular chain segment movement caused by excessive cross - linking degree in the system, thereby effectively improving the damping performance of the waterborne coating. At the same time, even if the damping performance increases, the compounding of the base emulsion and the cross - linker has a synergistic effect, and the presence of multiple aromatic ring rigid groups in the cross - linker effectively increases the corrosion resistance of the waterborne coating; in addition, the present invention introduces an acrylic polymer with a four - layer core - shell structure as a cross - linker into the system. The modified silica in the multi - layer core - shell structure can toughen and modify the waterborne coating, and because its surface is coated with an inner layer, an intermediate layer and an outer layer in sequence, this enables the cross - linker to be evenly dispersed in the system without a large amount of agglomeration, and the cross - linker with a multi - layer core - shell structure can cross - link with the base emulsion inside the system. Therefore, it can improve the mechanical properties and hardness of the waterborne coating. Coupled with the interaction of the compounded base emulsions, it can also effectively enhance the damping performance, and at the same time further improve the corrosion resistance and flame retardancy.

[0185] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

[0186] The present invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A water-based coating based on modified acrylic resin, characterized in that: The method comprises the following raw materials in parts by weight: 100-105 parts of base emulsion, 8-12 parts of cross-linking agent, 0.5-0.8 parts of triethanolamine, 0.4-0.8 parts of defoaming agent, and 0.3-0.6 parts of wetting and dispersing agent; The base emulsion is obtained by mixing water-based acrylic resin and core-shell acrylic ester in a mass ratio of 80-85:15-20; The crosslinking agent is a four-layer core-shell structure, and the four-layer core-shell structure is prepared by a core layer emulsion, an inner layer emulsion, an intermediate layer emulsion and an outer layer emulsion; The core layer emulsion is prepared from modified silicon dioxide; The inner layer emulsion is prepared from methyl methacrylate and styrene; The intermediate layer emulsion is prepared from butyl acrylate, methyl methacrylate and modified graphene; The outer layer emulsion is prepared from butyl acrylate, methyl methacrylate and styrene; The modified graphene is amino-modified graphene oxide.

2. The water-based coating based on modified acrylic resin according to claim 1, characterized in that: The preparation process of the basic emulsion is as follows: Step A1. Methyl methacrylate, styrene, a crosslinking agent and deionized water are mixed evenly, an emulsifier is added, and pre-emulsification is carried out at 70-75° C. for 28-32 minutes at a speed of 280-300 r / min, and then an initiator is added and reacted for 150-160 minutes to obtain a mixed solution A; Step A2. Mix butyl acrylate and isooctyl acrylate evenly, add an initiator, and mix evenly to obtain a mixed solution B; Step A3. Add the mixed solution A dropwise to the mixed solution B at a flow rate of 1.8-2.2 r / min. After the addition is completed, continue the reaction for 150-160 min to obtain a core-shell type acrylate.

3. The water-based coating based on modified acrylic resin according to claim 2, characterized in that, The usage ratio of methyl methacrylate, styrene, crosslinking agent, deionized water, emulsifier and initiator in step A1 is 6-9 g: 6-9 g: 0.15-0.45 g: 40-50 mL: 0.11-0.16 g: 0.08-0.12 g; The cross-linking agent in step A1 is divinylbenzene; The emulsifier in step A1 is any one of an anionic emulsifier and a nonionic emulsifier; The anionic emulsifier is sodium dodecyl sulfate, and the nonionic emulsifier is OP-10; The initiator in step A1 is ammonium persulfate.

4. The water-based coating based on modified acrylic resin according to claim 2, characterized in that: In step A2, the usage ratio of butyl acrylate, octyl acrylate and initiator is 26-31 g: 4-7 g: 0.35-1.05 g; The initiator in step A2 is ammonium persulfate; The mass ratio of the mixed solution A to the mixed solution B in step A3 is 28-32:68-72.

5. The water-based coating based on modified acrylic resin according to claim 1, characterized in that: The preparation process of the cross-linking agent is as follows: Step B1. Add nano-silica to an ethanol aqueous solution, add KH570 after uniform dispersion, and then add oxalic acid to adjust the pH to 4, react at 68-72°C for 110-120min, filter, and wash with ethanol to obtain modified silica; Step B2. Add modified silica, butyl acrylate, styrene and a crosslinking agent to deionized water, add an emulsifier, place at 65-70 ° C for 30-35 minutes under nitrogen protection to obtain a pre-emulsification solution, then add an initiator, and react at a stirring speed of 280-300 r / min for 150-160 minutes to obtain an inner layer emulsion; Step B3. Add an initiator to the inner layer emulsion, and drip butyl acrylate, methyl methacrylate and a crosslinking agent therein using a peristaltic pump at a flow rate of 1.8-2.2 r / min. After the dripping is completed, continue the polymerization reaction for 150-160 min to obtain an intermediate layer pre-emulsion; Step B4. dispersing graphene oxide in deionized water to obtain a graphene oxide dispersion, adding a silane coupling agent to anhydrous ethanol, and dispersing uniformly by ultrasonication for 5-7 minutes to obtain a silane coupling agent dispersion, ultrasonically mixing the graphene oxide dispersion and the silane coupling agent dispersion, reacting in an oil bath at 78-86° C. for 6-8 hours, and centrifuging for standby use to obtain functionalized graphene; Step B5. The pH of the intermediate layer pre-emulsion is adjusted to 8-9, functionalized graphene is added, and the intermediate layer emulsion is obtained after ultrasonic treatment for 30-50 minutes; Step B6. Add an initiator to the middle layer emulsion and drop butyl acrylate, methyl methacrylate, styrene and hydroxyethyl methacrylate using a peristaltic pump at a flow rate of 1.8-2.2 r / min. After the dropwise addition is completed, continue the polymerization reaction for 150-160 minutes to obtain a crosslinking agent.

6. The water-based coating based on modified acrylic resin according to claim 5, characterized in that: The usage ratio of nano-silica, ethanol aqueous solution and KH570 in step B1 is 0.3-0.6 g: 10-14 mL: 0.035-0.045 g; The volume fraction of the ethanol aqueous solution in step B1 is 78%-82%; The amount ratio of modified silica, butyl acrylate, styrene, crosslinking agent, deionized water, emulsifier and initiator in step B2 is 1.5-2g: 1.2-4.2g: 10.11-13.8g: 0.6-0.9g: 36-42mL: 0.4-0.7g: 0.5-0.8g; The cross-linking agent in step B2 is divinylbenzene; The emulsifier in step B2 is obtained by mixing an anionic emulsifier and a nonionic emulsifier in a mass ratio of 0.2-0.4:0.2-0.3; In step B2, the anionic emulsifier is sodium dodecyl sulfate, and the nonionic emulsifier is OP-10; The initiator in step B2 is ammonium persulfate.

7. The water-based coating based on modified acrylic resin according to claim 5, characterized in that: The usage ratio of the inner layer emulsion, initiator, butyl acrylate, methyl methacrylate and crosslinking agent in step B3 is 40-42 mL: 0.2-0.4 g: 12-14 g: 15.3-18 g: 0.4-0.7 g; The initiator in step B3 is ammonium persulfate; The cross-linking agent in step B3 is divinylbenzene.

8. The water-based coating based on modified acrylic resin according to claim 5, characterized in that: The usage ratio of graphene oxide and deionized water in step B4 is 3-6 g: 100-105 mL; The usage ratio of the silane coupling agent and anhydrous ethanol in step B4 is 5-9 g: 80-85 mL; The volume ratio of the graphene oxide dispersion and the silane coupling agent dispersion in step B4 is 100-105:80-85; The silane coupling agent in step B4 is KH-550.

9. The water-based coating based on modified acrylic resin according to claim 5, characterized in that: The ratio of the intermediate layer pre-emulsion to the functionalized graphene in step B5 is 38-42 mL: 0.1-0.2 g; The usage ratio of the intermediate layer emulsion, initiator, butyl acrylate, methyl methacrylate, styrene and hydroxyethyl methacrylate in step B6 is 40-42 mL: 0.3-0.6 g: 16-23 g: 5-9 g: 5-7 g: 0.45-1.35 g; The initiator in step B6 is ammonium persulfate.

10. A method for preparing a water-based coating based on a modified acrylic resin according to any one of claims 1 to 9, characterized in that: The following steps are involved: The base emulsion, the crosslinking agent, the triethanolamine, the defoaming agent and the wetting and dispersing agent are uniformly mixed to obtain a water-based coating based on the modified acrylic resin.

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