Solvent resistant waterborne transfer coating and method of making

Abstract

The application relates to the technical field of paint, and particularly discloses a solvent-resistant water-based transfer paint and a preparation method thereof. The solvent-resistant water-based transfer paint comprises the following raw materials: a water-based polyurethane resin, a water-based acrylic emulsion, a modified polyethylene wax emulsion, a crosslinking agent, a wetting agent, a neutralizing agent, a thickening agent, a defoaming agent, a film-forming agent, a functional additive and deionized water. The water-based polyurethane resin, the water-based acrylic emulsion and the modified polyethylene wax emulsion are compounded, and the crosslinking agent, the wetting agent and the functional additive are used in cooperation, so that the final product has excellent solvent resistance, high surface hardness and good transfer peelability.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a solvent-resistant water-based transfer coating and its preparation method. Background Technology

[0002] Transfer coatings are widely used in decorative paper, packaging materials and labels to form coatings with specific patterns or functions on the surface of a substrate. Traditional transfer coatings mostly use organic solvent-based resins as film-forming substances. Although they have good film-forming properties, adhesion and solvent resistance, they contain a large amount of volatile organic compounds (VOCs), which can easily cause environmental pollution and harm the health of operators during production and use, and do not meet the increasingly stringent environmental protection regulations.

[0003] Therefore, waterborne transfer coatings have gradually become a research hotspot in recent years. However, existing waterborne transfer coatings generally have the following problems: On the one hand, when waterborne acrylic emulsions or waterborne polyurethane emulsions are used as the main film-forming resins, although good flexibility and adhesion can be obtained, their crosslinking density is limited, which makes the coating prone to swelling, whitening or even peeling when in contact with alcohols, ketones or aromatic solvents, making it difficult to meet the requirements of high solvent resistance; on the other hand, in order to improve solvent resistance, some technical solutions attempt to introduce resins with high glass transition temperatures or increase the amount of crosslinking agents, but this often leads to a sharp increase in coating viscosity, poor leveling, or problems such as coating brittleness and incomplete separation from the base film during the transfer and peeling process.

[0004] Furthermore, in the process of introducing functional components such as modified polyethylene wax, most existing technologies only involve simple physical blending of commercially available general-purpose polyethylene wax emulsions with water-based resins. Due to the poor compatibility between wax emulsions and water-based resins, and the lack of effective chemical bonding at the interface, agglomeration, delamination, or emulsification instability are likely to occur, resulting in a large number of microscopic defects inside the coating after film formation, which affects the surface smoothness and solvent resistance uniformity of the final coating.

[0005] In summary, existing technologies struggle to fundamentally resolve the contradiction between high solvent resistance, good transfer and peelability, and long-term storage stability of coatings through deep chemical modification of functional components, while ensuring the environmental friendliness of the water-based system. Based on the above, this invention proposes a solvent-resistant water-based transfer coating and its preparation method. Summary of the Invention

[0006] To address the challenges of existing waterborne transfer coatings in simultaneously achieving solvent resistance, transfer peelability, and system stability, this invention proposes a solvent-resistant waterborne transfer coating and its preparation method.

[0007] In a first aspect, the present invention provides a solvent-resistant water-based transfer coating, which adopts the following technical solution: A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 28-35 parts waterborne polyurethane resin, 18-25 parts waterborne acrylic emulsion, 10-15 parts modified polyethylene wax emulsion, 0.3-1.2 parts crosslinking agent, 0.2-0.5 parts wetting agent, 0.3-0.8 parts neutralizing agent, 0.2-0.6 parts thickener, 0.1-0.3 parts defoamer, 0.5-1.5 parts film-forming agent, 0.2-0.6 parts functional additives, and 15-30 parts deionized water.

[0008] Preferably, the waterborne polyurethane resin is an anionic waterborne polyurethane resin with a solid content of 30-40%.

[0009] Preferably, the solid content of the aqueous acrylic emulsion is 20-40%, and the glass transition temperature is 100-120°C.

[0010] Preferably, the modified polyethylene wax emulsion is prepared by sequentially oxidizing, grafting, modifying with bifunctional groups, and emulsifying a polyethylene wax emulsion.

[0011] Preferably, the modified polyethylene wax emulsion is prepared by the following steps: S1. Under stirring, add deionized water to the polyethylene wax emulsion and continue stirring and diluting for 5-10 minutes. Pass the emulsion through an 80-100 mesh filter to obtain a diluted emulsion. Disperse the diluted emulsion ultrasonically at 40-45℃ for 10-15 minutes, then add an oxidant. Under continuous ultrasonic assistance, raise the temperature to 85-90℃ and maintain the temperature for 2-3 hours. After the reaction is complete, cool the system to 45-50℃ and filter it a second time through an 180-200 mesh filter. Adjust the pH value to 7.5-8.5 with an alkaline solution to obtain an oxidized polyethylene wax emulsion. S2. After heating the system to 110-115℃ in a pressurized sealed container, N-hydroxymethylacrylamide is added to the oxidized polyethylene wax emulsion at a uniform rate over 40-60 min under nitrogen protection and stirring. Then, the mixture is stirred continuously at 110-120℃ for 20-30 min, and then the catalyst is added. The temperature is then raised to 120-130℃ and the reaction is maintained for 2-3 h to obtain the grafted modified polyethylene wax emulsion. S3. Cool the system to 90-95℃, add γ-glycidoxypropyltrimethoxysilane to the grafted modified polyethylene wax emulsion, and react for 30-40 min under the alkaline catalytic conditions of the system itself, with stirring and nitrogen protection. Then add p-dodecylbenzenesulfonyl chloride, raise the temperature to 95-100℃, and continue the reaction for 1-2 h. After the reaction is completed, cool the system to 50-60℃ and add an alcohol-water solution. Sonicate the solution for 5-10 min, and filter it through a 160-200 mesh filter to obtain the bifunctional modified polyethylene wax emulsion intermediate. S4. Heat the system to 90-95℃, add the composite emulsifier to the bifunctional modified polyethylene wax emulsion intermediate, stir and disperse for 30-40 minutes, add deionized water at 80-90℃, and homogenize by circulation at 40-50MPa 3-5 times to obtain a crude emulsion; cool the crude emulsion system to 50-55℃, adjust the pH value to 8.0-8.5 with ammonia solution, and then filter through a 180-200 mesh sieve to obtain the modified polyethylene wax emulsion.

[0012] Preferably, the stirring rate in step S1 is 300-400 rpm.

[0013] Preferably, the mass ratio of polyethylene wax emulsion to deionized water in step S1 is 1:1-2.

[0014] Preferably, the amount of oxidant used in step S1 is 3-8% of the mass of the diluted emulsion.

[0015] Preferably, the oxidant in step S1 is selected from at least one of tert-butyl hydroperoxide, hydrogen peroxide, ammonium persulfate, and potassium permanganate.

[0016] Preferably, the parameters for ultrasonic dispersion in step S1 are: power of 200-400W, frequency of 20-40KHz, pulse mode, working for 2-3 seconds, and interval of 2-4 seconds.

[0017] Preferably, the alkaline solution in step S1 is an ammonia solution, a sodium hydroxide solution, or a potassium hydroxide solution.

[0018] Preferably, the pressurized sealed container in step S2 is a sealed reaction vessel with an internal pressure of 0.2-0.4 MPa.

[0019] Preferably, the stirring rate in step S2 is 350-450 rpm.

[0020] Preferably, in step S2, the mass ratio of N-hydroxymethylacrylamide to oxidized polyethylene wax emulsion is 1:10-20, wherein the mass of the oxidized polyethylene wax emulsion is based on its solid content.

[0021] Preferably, the amount of catalyst used in step S2 is 0.5-1.2% of the solid content of the oxidized polyethylene wax emulsion.

[0022] Preferably, the catalyst in step S2 is benzoyl peroxide or azobisisobutyronitrile.

[0023] Preferably, in step S3, the mass ratio of the grafted modified polyethylene wax emulsion, γ-glycidoxypropyltrimethoxysilane, and p-dodecylbenzenesulfonyl chloride is 100:1-3:1-2, wherein the mass of the grafted modified polyethylene wax emulsion is based on its solid content.

[0024] Preferably, the amount of alcohol-water solution used in step S3 is 20-50% of the solid content of the grafted modified polyethylene wax emulsion.

[0025] Preferably, the alcohol-water solution in step S3 is an aqueous solution of ethanol or an aqueous solution of isopropanol.

[0026] Preferably, the stirring rate in step S3 is 400-500 rpm.

[0027] Preferably, the parameters for ultrasonic processing in step S3 are: power of 300-400W, frequency of 25-40KHz, pulse mode, working time of 2-3s, and interval of 2-4s.

[0028] Preferably, in step S4, the mass ratio of the bifunctional modified polyethylene wax emulsion intermediate, the composite emulsifier, and the deionized water is 100:3-6:150-250, wherein the mass of the bifunctional modified polyethylene wax emulsion intermediate is based on its solid content.

[0029] Preferably, the composite emulsifier in step S4 is a mixture of fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate in a mass ratio of 2-4:1.

[0030] Preferably, the stirring and dispersion rate in step S4 is 250-350 rpm.

[0031] Preferably, the modified polyethylene wax emulsion in step S4 has a solid content of 25-30% and a particle size of 150-180 nm.

[0032] Preferably, the crosslinking agent is selected from at least one of trimethylolpropane-tris[3-(2-methylaziridinyl)propionate], hexamethylene diisocyanate isocyanurate trimer, and polycarbodiimide.

[0033] Preferably, the wetting agent is 2,4,7,9-tetramethyl-5-decyn-4,7-diol or polyether-modified polydimethylsiloxane.

[0034] Preferably, the neutralizing agent is 2-amino-2-methyl-1-propanol, ammonia, or N,N-dimethylethanolamine.

[0035] Preferably, the thickener is selected from at least one of hydrophobically modified ethoxylated polyurethane, carboxylated acrylic acid copolymer, and hydroxyethyl cellulose.

[0036] Preferably, the defoamer is polydimethylsiloxane, mineral oil, or polyether-modified polysiloxane.

[0037] Preferably, the film-forming agent is 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, dipropylene glycol butyl ether, or ethylene glycol phenyl ether.

[0038] Preferably, the functional additive is a mixture of n-octyltriethoxysilane and bis(dioctylpyrophosphoryloxy)ethylene titanate.

[0039] Preferably, the functional additive is n-octyltriethoxysilane and bis(dioctylpyrophosphoryloxy)ethylene titanate in a mass ratio of 1:1-2.

[0040] Secondly, the present invention provides a method for preparing a solvent-resistant water-based transfer coating, which adopts the following technical solution: A method for preparing a solvent-resistant water-based transfer coating includes the following steps: Step 1: Heat the modified polyethylene wax emulsion system to 45-50℃, and add waterborne polyurethane resin dropwise at a uniform rate over 30-40 minutes while stirring. After the dropwise addition is complete, continue stirring at the temperature for 20-30 minutes. Then add waterborne acrylic emulsion and wetting agent, and ultrasonically disperse at 50-55℃ for 10-15 minutes to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.0–8.5, add a thickener, stir at 40–45℃ for 30–40 minutes, and then filter under pressure through a 200–300 mesh filter 1–3 times to obtain a thickened and neutralized base material. Step 3: While stirring, add crosslinking agent and functional additive to thickening and neutralizing base material. Heat the system to 55-60℃ and continue stirring for 20-30 minutes. Then, add film-forming agent dropwise at a uniform rate over 15-20 minutes. After the dropwise addition is complete, let it stand for 10-15 minutes. Then, add defoamer, shear and disperse for 5-10 minutes, and then cure for 30-40 minutes to obtain composite coating. Step 4: Cool the composite coating system to 30-40℃, add deionized water, filter through a 350-400 mesh sieve, and vacuum degas at 30-40℃ for 20-30 minutes to obtain a solvent-resistant water-based transfer coating with a viscosity of 80-100 mPa.s.

[0041] Preferably, the stirring rate in step 1 is 300-500 rpm.

[0042] Preferably, the parameters for ultrasonic dispersion in step 1 are: power of 150-300W, frequency of 20-40KHz, pulse mode, working for 2-3 seconds, and interval of 2-3 seconds.

[0043] Preferably, the pressure of the pressure filtration in step 2 is 0.05-0.15 MPa.

[0044] Preferably, the stirring rate in step 2 is 200-300 rpm.

[0045] Preferably, the stirring rate in step 3 is 500-800 rpm; the shear dispersion rate is 1000-1200 rpm.

[0046] Preferably, the vacuum degassing conditions in step 4 are a vacuum degree of -0.08 MPa to -0.10 MPa.

[0047] In summary, the present invention has the following beneficial effects: 1. This invention combines waterborne polyurethane resin, waterborne acrylic emulsion and modified polyethylene wax emulsion, and supplements them with crosslinking agents, wetting agents and functional additives to make the final product have excellent solvent resistance, high surface hardness and good transfer and peel properties.

[0048] 2. This invention uses a modified polyethylene wax emulsion with a specific particle size as a functional component. Its fine particle size ensures good compatibility with waterborne polyurethane and waterborne acrylic emulsions. At the same time, the wax component migrates to the surface during the film formation process, giving the coating suitable slip and release properties. This allows the coated transfer film to be cleanly and thoroughly peeled off after being laminated with substrates such as paper and plastics, leaving no residue or fragments.

[0049] 3. The functional additive in this invention is a compound of n-octyltriethoxysilane and bis(dioctylpyrophosphoryloxy)ethylene titanate. The n-octyltriethoxysilane, through hydrolysis and condensation, constructs a dense organosilicon hydrophobic network within and on the surface of the coating, effectively preventing water molecules and organic solvents from penetrating into the coating, thus fundamentally improving the coating's water resistance and solvent resistance. Simultaneously, the bis(dioctylpyrophosphoryloxy)ethylene titanate, through its phosphate groups reacting with the inorganic components or the hydroxyl groups on the wax surface, significantly improves the interfacial compatibility between the resin and the wax emulsion, inhibits aggregation, and reduces system viscosity fluctuations. The combined effect of these two additives ensures a smooth and high-gloss coating surface while significantly improving the coating's adhesion, scratch resistance, and the smoothness of transfer and peeling. Detailed Implementation

[0050] The present invention will be further described in detail below with reference to the embodiments.

[0051] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0052] The key raw materials used in this invention are sourced from the following sources: Waterborne polyurethane resin: Model HX-3028, solid content 33%, anionic aliphatic, purchased from Yixing Huaxia Chemical Materials Co., Ltd. Aqueous acrylic emulsion: Grade BA-8407, solid content 30%, glass transition temperature 110℃, purchased from Anhui Zhongen Chemical Co., Ltd. Polyethylene wax emulsion: Model AQUACER-513, solid content 35%, purchased from Shanghai Longdi Chemical Co., Ltd. tert-butyl hydroperoxide: CAS No. 75-91-2, purchased from Nanjing Baiju Technology Co., Ltd.; N-hydroxymethylacrylamide: CAS No. 924-42-5, purchased from Shandong Guanchang Chemical Technology Co., Ltd.; Benzoyl peroxide: CAS No. 94-36-0, purchased from Shandong Kunteng Chemical Co., Ltd.; γ-glycidyl etheroxypropyltrimethoxysilane: CAS No. 2530-83-8, purchased from Shandong Yuanjin New Materials Co., Ltd.; p-Dodecylbenzenesulfonyl chloride: CAS No. 52499-14-6, purchased from Wuhan Kemic Biomedical Technology Co., Ltd.; Fatty alcohol polyoxyethylene ether: Model AEO-9, purchased from Jinan Pulian Chemical Technology Co., Ltd.; Sodium dodecyl sulfate: CAS No. 151-21-3, purchased from Zhengzhou Chengjin Chemical Products Co., Ltd.; Trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]: CAS No. 64265-57-2, purchased from Hubei Xingyan New Materials Technology Co., Ltd.; 2,4,7,9-Tetramethyl-5-decyn-4,7-diol: CAS No. 126-86-3, purchased from Zhongshan Dixin Chemical Co., Ltd.; 2-Amino-2-methyl-1-propanol: CAS No. 124-68-5, purchased from Nanjing Chemical Reagent Co., Ltd.; Hydrophobically modified ethoxylated polyurethane: model ACRYSOL RM 12W, purchased from Nanjing Kexulai Chemical Co., Ltd. Polydimethylsiloxane: CAS No. 9006-65-9, purchased from Wuhan Jiyesheng Chemical Co., Ltd.; 2,2,4-Trimethyl-1,3-pentanediol monoisobutyrate: CAS No. 25265-77-4, purchased from Wuhan Yuqing Jiaheng Pharmaceutical Co., Ltd.; n-Octyltriethoxysilane: CAS No. 2943-75-1, purchased from Nanjing Xuanhao New Materials Technology Co., Ltd.; Bis(dioctylpyrophosphoryloxy)ethylene titanate: CAS No. 65467-75-6, purchased from Nanjing Nengde New Material Technology Co., Ltd.

[0053] Preparation Examples 1-3 and Comparative Preparation Examples 1-3 provide a method for preparing a modified polyethylene wax emulsion.

[0054] Preparation Example 1 The modified polyethylene wax emulsion is prepared by the following steps: S1. At a stirring speed of 300 rpm, add deionized water equal to the weight of the polyethylene wax emulsion and continue stirring and diluting for 10 min. Pass the emulsion through an 80-mesh filter to obtain a diluted emulsion. Disperse the diluted emulsion by ultrasonication at 40°C (power 200W, frequency 20KHz, pulse mode, 2s working, 2s intermittent) for 15 min. Add tert-butyl hydrogen peroxide (3% of the weight of the diluted emulsion) and raise the temperature to 85°C under continuous ultrasonic assistance. Keep the temperature for 3 h. After the reaction is completed, cool the system to 45°C and filter it again through an 180-mesh filter. Adjust the pH value to 7.5 with a 20% ammonia solution to obtain an oxidized polyethylene wax emulsion. S2. The system was heated to 110°C in a closed reactor (with an internal pressure of 0.2 MPa). The mass ratio of N-hydroxymethylacrylamide to oxidized polyethylene wax emulsion was controlled at 1:10 (based on the solid content of the emulsion). Under nitrogen protection, N-hydroxymethylacrylamide was added to the oxidized polyethylene wax emulsion at a stirring speed of 350 rpm over 60 min. Then, the mixture was stirred continuously at 110°C for 30 min. Benzoyl peroxide with a solid content of 0.5% of the oxidized polyethylene wax emulsion was added. The temperature was then raised to 120°C and the reaction was maintained for 3 h to obtain the grafted modified polyethylene wax emulsion. S3. Cool the system to 90℃, and control the mass ratio of grafted modified polyethylene wax emulsion, γ-glycidoxypropyltrimethoxysilane and p-dodecylbenzenesulfonyl chloride to be 100:1:1 (based on the solid content of the emulsion). Add γ-glycidoxypropyltrimethoxysilane to the grafted modified polyethylene wax emulsion. Under the alkaline catalytic conditions of the system itself, react for 40 min at a stirring rate of 400 rpm and under nitrogen protection. Then add p-dodecylbenzenesulfonyl chloride, raise the temperature to 95℃, and continue the reaction for 2 h. After the reaction is completed, cool the system to 50℃ and add an ethanol aqueous solution with a solid content of 20% of the grafted modified polyethylene wax emulsion (the volume ratio of anhydrous ethanol to deionized water is 1:1). Control the power to be 300W, the frequency to be 25KHz, and use the pulse mode, working for 2s, intermittent for 2s, and ultrasonically treat for 10 min. Filter through a 160-mesh filter to obtain the bifunctional modified polyethylene wax emulsion intermediate. S4. Heat the system to 90℃, and control the mass ratio of the bifunctional modified polyethylene wax emulsion intermediate, the composite emulsifier, and deionized water to 100:3:150 (based on the solid content of the intermediate). Add the composite emulsifier (including fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate in a mass ratio of 2:1) to the bifunctional modified polyethylene wax emulsion intermediate. Stir and disperse at 250 rpm for 40 min, then add deionized water at 80℃, and homogenize three times at 40 MPa to obtain a crude emulsion. Cool the crude emulsion system to 50℃, adjust the pH to 8.0 with a 25% ammonia solution, and then filter through a 180-mesh sieve to obtain a modified polyethylene wax emulsion with a solid content of 25% and a particle size of 150 nm.

[0055] Preparation Example 2 The modified polyethylene wax emulsion is prepared by the following steps: S1. At a stirring speed of 350 rpm, add 1.5 times its own weight of deionized water to the polyethylene wax emulsion and continue stirring and diluting for 7 min. Pass the emulsion through a 90-mesh filter to obtain a diluted emulsion. Disperse the diluted emulsion by ultrasonication at 43°C (power 300W, frequency 30KHz, pulse mode, 2s working, 2s intermittent) for 12 min. Add tert-butyl hydrogen peroxide (6% of the mass of the diluted emulsion). Under continuous ultrasonic assistance, raise the temperature to 87°C and keep it at that temperature for 2.5 h. After the reaction is completed, cool the system to 48°C and filter it a second time through a 190-mesh filter. Adjust the pH value to 7.7 with a 20% ammonia solution to obtain an oxidized polyethylene wax emulsion. S2. The system was heated to 113°C in a closed reactor (with an internal pressure of 0.3 MPa). The mass ratio of N-hydroxymethylacrylamide to oxidized polyethylene wax emulsion was controlled at 1:15 (based on the solid content of the emulsion). Under nitrogen protection, N-hydroxymethylacrylamide was added to the oxidized polyethylene wax emulsion at a stirring speed of 400 rpm over 50 min. Then, the mixture was stirred continuously at 115°C for 25 min. Benzoyl peroxide with a solid content of 0.8% of the oxidized polyethylene wax emulsion was added. The temperature was then raised to 125°C and the reaction was maintained for 2.5 h to obtain the grafted modified polyethylene wax emulsion. S3. Cool the system to 93℃, and control the mass ratio of grafted modified polyethylene wax emulsion, γ-glycidoxypropyltrimethoxysilane and p-dodecylbenzenesulfonyl chloride to be 100:2:1.5 (based on the solid content of the emulsion). Add γ-glycidoxypropyltrimethoxysilane to the grafted modified polyethylene wax emulsion. Under the alkaline catalytic conditions of the system itself, react for 35 min at a stirring rate of 450 rpm and under nitrogen protection. Then add p-dodecylbenzenesulfonyl chloride, raise the temperature to 97℃, and continue the reaction for 1.5 h. After the reaction is completed, cool the system to 55℃ and add an ethanol aqueous solution with a solid content of 35% of the grafted modified polyethylene wax emulsion (the volume ratio of anhydrous ethanol to deionized water is 1:1). Control the power to be 350W, the frequency to be 35KHz, and use the pulse mode, working for 2 seconds, pausing for 2 seconds, and ultrasonically treating for 8 min. Filter through a 180-mesh filter to obtain the bifunctional modified polyethylene wax emulsion intermediate. S4. Heat the system to 92℃, and control the mass ratio of the bifunctional modified polyethylene wax emulsion intermediate, the composite emulsifier, and deionized water to 100:5:198 (based on the solid content of the intermediate). Add the composite emulsifier (including fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate in a mass ratio of 3:1) to the bifunctional modified polyethylene wax emulsion intermediate. Stir and disperse at 300 rpm for 35 min, then add deionized water at 85℃, and homogenize 4 times at 45 MPa to obtain a crude emulsion. Cool the crude emulsion system to 53℃, adjust the pH value to 8.2 with a 25% ammonia solution, and then filter through a 190-mesh sieve to obtain a modified polyethylene wax emulsion with a solid content of 28% and a particle size of 170 nm.

[0056] Preparation Example 3 The modified polyethylene wax emulsion is prepared by the following steps: S1. At a stirring speed of 400 rpm, add twice the mass of deionized water to the polyethylene wax emulsion and continue stirring and diluting for 5 min. Pass the emulsion through a 100-mesh filter to obtain a diluted emulsion. Disperse the diluted emulsion by ultrasonication at 45°C (power 400W, frequency 40KHz, pulse mode, 3s working, 4s intermittent) for 10 min. Add tert-butyl hydrogen peroxide (8% of the mass of the diluted emulsion), raise the temperature to 90°C with continuous ultrasonic assistance, and keep the reaction at this temperature for 2 h. After the reaction is completed, cool the system to 50°C, filter it a second time through a 200-mesh filter, and adjust the pH value to 8.5 with a 20% ammonia solution to obtain an oxidized polyethylene wax emulsion. S2. The system was heated to 115°C in a closed reactor (with an internal pressure of 0.4 MPa). The mass ratio of N-hydroxymethylacrylamide to oxidized polyethylene wax emulsion was controlled at 1:20 (based on the solid content of the emulsion). Under nitrogen protection, N-hydroxymethylacrylamide was added to the oxidized polyethylene wax emulsion at a stirring speed of 450 rpm over 40 min. Then, the mixture was stirred continuously at 120°C for 20 min. Benzoyl peroxide with a solid content of 1.2% of the oxidized polyethylene wax emulsion was added. The temperature was then raised to 130°C and the reaction was maintained for 2 h to obtain the grafted modified polyethylene wax emulsion. S3. Cool the system to 95℃, and control the mass ratio of grafted modified polyethylene wax emulsion, γ-glycidoxypropyltrimethoxysilane and p-dodecylbenzenesulfonyl chloride to be 100:3:2 (based on the solid content of the emulsion). Add γ-glycidoxypropyltrimethoxysilane to the grafted modified polyethylene wax emulsion. Under the alkaline catalytic conditions of the system itself, react for 30 min at a stirring rate of 500 rpm and under nitrogen protection. Then add p-dodecylbenzenesulfonyl chloride, raise the temperature to 100℃, and continue the reaction for 1 h. After the reaction is completed, cool the system to 60℃ and add an ethanol aqueous solution with a solid content of 50% of the grafted modified polyethylene wax emulsion (the volume ratio of anhydrous ethanol to deionized water is 1:1). Control the power to be 400W, the frequency to be 40KHz, and use the pulse mode. Work for 3s, pause for 4s, and sonicate for 5 min. Filter through a 200-mesh filter to obtain the bifunctional modified polyethylene wax emulsion intermediate. S4. Heat the system to 95℃, and control the mass ratio of the bifunctional modified polyethylene wax emulsion intermediate, the composite emulsifier, and deionized water to 100:6:250 (based on the solid content of the intermediate). Add the composite emulsifier (including fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate in a mass ratio of 4:1) to the bifunctional modified polyethylene wax emulsion intermediate. Stir and disperse at 350 rpm for 30 min, then add deionized water at 90℃, and homogenize 5 times at 50 MPa to obtain a crude emulsion. Cool the crude emulsion system to 55℃, adjust the pH value to 8.5 with a 25% ammonia solution, and then filter through a 200-mesh sieve to obtain a modified polyethylene wax emulsion with a solid content of 30% and a particle size of 180 nm.

[0057] Comparative Preparation Example 1 The modified polyethylene wax emulsion is prepared by the following steps: S1. At a stirring speed of 300 rpm, add deionized water equal to the weight of the polyethylene wax emulsion and continue stirring and diluting for 10 min. Pass the emulsion through an 80-mesh filter to obtain a diluted emulsion. Disperse the diluted emulsion by ultrasonication at 40°C (power 200W, frequency 20KHz, pulse mode, 2s working, 2s intermittent) for 15 min. Add tert-butyl hydrogen peroxide (3% of the weight of the diluted emulsion) and raise the temperature to 85°C under continuous ultrasonic assistance. Keep the temperature for 3 h. After the reaction is completed, cool the system to 45°C and filter it again through an 180-mesh filter. Adjust the pH value to 7.5 with a 20% ammonia solution to obtain an oxidized polyethylene wax emulsion. S2. After heating the system to 110°C in a closed reactor (with an internal pressure of 0.2 MPa), add benzoyl peroxide with a solid content of 0.5% to the oxidized polyethylene wax emulsion, continue heating to 120°C and keep the reaction at that temperature for 3 hours to obtain an ungrafted modified polyethylene wax emulsion. S3. Cool the system to 90℃, and control the mass ratio of ungrafted modified polyethylene wax emulsion, γ-glycidoxypropyltrimethoxysilane and p-dodecylbenzenesulfonyl chloride to be 100:1:1 (based on emulsion solid content). Add γ-glycidoxypropyltrimethoxysilane to the ungrafted modified polyethylene wax emulsion, and react for 40 min under nitrogen protection and stirring at 400 rpm. Then add p-dodecylbenzenesulfonyl chloride, raise the temperature to 95℃, and continue the reaction for 2 h. After the reaction is completed, cool the system to 50℃ and add an ethanol aqueous solution with a solid content of 20% of the ungrafted modified polyethylene wax emulsion (anhydrous ethanol to deionized water volume ratio of 1:1). Control the power to be 300W, the frequency to be 25KHz, and use pulse mode, working for 2s, intermittent for 2s, and ultrasonically treat for 10 min. Filter through a 160-mesh filter to obtain the silane-sulfonyl chloride modified polyethylene wax emulsion intermediate. S4. Heat the system to 90℃, and control the mass ratio of silane-sulfonyl chloride modified polyethylene wax emulsion intermediate, composite emulsifier and deionized water to 100:3:150 (based on the solid content of the intermediate). Add composite emulsifier (including fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate in a mass ratio of 2:1) to the silane-sulfonyl chloride modified polyethylene wax emulsion intermediate. Stir and disperse at a rate of 250 rpm for 40 min, then add deionized water at 80℃, and homogenize three times at 40 MPa to obtain a crude emulsion. Cool the crude emulsion system to 50℃, adjust the pH value to 8.0 with a 25% ammonia solution, and then filter through a 180-mesh sieve to obtain a modified polyethylene wax emulsion with a solid content of 25% and a particle size of 150 nm.

[0058] Comparative Preparation Example 2 The modified polyethylene wax emulsion is prepared by the following steps: S1. At a stirring speed of 300 rpm, add deionized water equal to the weight of the polyethylene wax emulsion and continue stirring and diluting for 10 min. Pass the emulsion through an 80-mesh filter to obtain a diluted emulsion. Disperse the diluted emulsion by ultrasonication at 40°C (power 200W, frequency 20KHz, pulse mode, 2s working, 2s intermittent) for 15 min. Add tert-butyl hydrogen peroxide (3% of the weight of the diluted emulsion) and raise the temperature to 85°C under continuous ultrasonic assistance. Keep the temperature for 3 h. After the reaction is completed, cool the system to 45°C and filter it again through an 180-mesh filter. Adjust the pH value to 7.5 with a 20% ammonia solution to obtain an oxidized polyethylene wax emulsion. S2. The system was heated to 110°C in a closed reactor (with an internal pressure of 0.2 MPa). The mass ratio of N-hydroxymethylacrylamide to oxidized polyethylene wax emulsion was controlled at 1:10 (based on the solid content of the emulsion). Under nitrogen protection, N-hydroxymethylacrylamide was added to the oxidized polyethylene wax emulsion at a stirring speed of 350 rpm over 60 min. Then, the mixture was stirred continuously at 110°C for 30 min. Benzoyl peroxide with a solid content of 0.5% of the oxidized polyethylene wax emulsion was added. The temperature was then raised to 120°C and the reaction was maintained for 3 h to obtain the grafted modified polyethylene wax emulsion. S3. Cool the system to 95℃, control the mass ratio of grafted modified polyethylene wax emulsion to p-dodecylbenzenesulfonyl chloride to be 100:1 (based on the solid content of the emulsion), add p-dodecylbenzenesulfonyl chloride to the grafted modified polyethylene wax emulsion, and react for 2 hours under nitrogen protection and stirring at 400 rpm. After the reaction is completed, cool the system to 50℃, and add an ethanol aqueous solution with a solid content of 20% of the grafted modified polyethylene wax emulsion (the volume ratio of anhydrous ethanol to deionized water is 1:1). Control the power to be 300W, the frequency to be 25KHz, and use the pulse mode, working for 2 seconds, pausing for 2 seconds, and ultrasonically treating for 10 minutes. Filter through a 160-mesh filter to obtain the sulfonyl chloride modified polyethylene wax emulsion. S4. Heat the system to 90℃, and control the mass ratio of sulfonyl chloride modified polyethylene wax emulsion, composite emulsifier and deionized water to 100:3:150 (based on intermediate solid content). Add composite emulsifier (including fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate in a mass ratio of 2:1) to the sulfonyl chloride modified polyethylene wax emulsion. Stir and disperse at 250 rpm for 40 min, then add deionized water at 80℃, and homogenize three times at 40 MPa to obtain a crude emulsion. Cool the crude emulsion system to 50℃, adjust the pH value to 8.0 with a 25% ammonia solution, and then filter through a 180-mesh sieve to obtain a modified polyethylene wax emulsion with a solid content of 25% and a particle size of 150 nm.

[0059] Comparative preparation example 3 The modified polyethylene wax emulsion is prepared by the following steps: S1. At a stirring speed of 300 rpm, add deionized water equal to the weight of the polyethylene wax emulsion and continue stirring and diluting for 10 min. Pass the emulsion through an 80-mesh filter to obtain a diluted emulsion. Disperse the diluted emulsion by ultrasonication at 40°C (power 200W, frequency 20KHz, pulse mode, 2s working, 2s intermittent) for 15 min. Add tert-butyl hydrogen peroxide (3% of the weight of the diluted emulsion) and raise the temperature to 85°C under continuous ultrasonic assistance. Keep the temperature for 3 h. After the reaction is completed, cool the system to 45°C and filter it again through an 180-mesh filter. Adjust the pH value to 7.5 with a 20% ammonia solution to obtain an oxidized polyethylene wax emulsion. S2. The system was heated to 110°C in a closed reactor (with an internal pressure of 0.2 MPa). The mass ratio of N-hydroxymethylacrylamide to oxidized polyethylene wax emulsion was controlled at 1:10 (based on the solid content of the emulsion). Under nitrogen protection, N-hydroxymethylacrylamide was added to the oxidized polyethylene wax emulsion at a stirring speed of 350 rpm over 60 min. Then, the mixture was stirred continuously at 110°C for 30 min. Benzoyl peroxide with a solid content of 0.5% of the oxidized polyethylene wax emulsion was added. The temperature was then raised to 120°C and the reaction was maintained for 3 h to obtain the grafted modified polyethylene wax emulsion. S3. Cool the system to 90℃, control the mass ratio of grafted modified polyethylene wax emulsion and γ-glycidoxypropyltrimethoxysilane to be 100:1 (based on emulsion solid content), add γ-glycidoxypropyltrimethoxysilane to the grafted modified polyethylene wax emulsion, react for 40 min under nitrogen protection and stirring at 400 rpm, cool to 50℃ after the reaction, and add an ethanol aqueous solution with a solid content of 20% of the grafted modified polyethylene wax emulsion (anhydrous ethanol to deionized water volume ratio of 1:1), control the power to be 300W, the frequency to be 25KHz, use pulse mode, work for 2s, pause for 2s, sonicate for 10 min, filter through a 160 mesh filter to obtain silane modified polyethylene wax emulsion; S4. Heat the system to 90℃, and control the mass ratio of silane-modified polyethylene wax emulsion, composite emulsifier, and deionized water to 100:3:150 (based on intermediate solid content). Add composite emulsifier (including fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate in a mass ratio of 2:1) to the silane-modified polyethylene wax emulsion. Stir and disperse at 250 rpm for 40 min, then add deionized water at 80℃. Homogenize the mixture three times at 40 MPa to obtain a crude emulsion. Cool the crude emulsion system to 50℃, adjust the pH to 8.0 with a 25% ammonia solution, and then filter through a 180-mesh sieve to obtain a modified polyethylene wax emulsion with a solid content of 25% and a particle size of 150 nm.

[0060] Examples 1-3 provide a solvent-resistant water-based transfer coating and its preparation method.

[0061] Example 1 A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 28 parts waterborne polyurethane resin, 18 parts waterborne acrylic emulsion, 10 parts modified polyethylene wax emulsion, 0.3 parts crosslinking agent, 0.2 parts wetting agent, 0.3 parts neutralizing agent, 0.2 parts thickener, 0.1 parts defoamer, 0.5 parts film-forming agent, 0.2 parts functional additives, and 15 parts deionized water.

[0062] The modified polyethylene wax emulsion was prepared in Preparation Example 1; the crosslinking agent was trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]; the wetting agent was 2,4,7,9-tetramethyl-5-decyn-4,7-diol; the neutralizing agent was 2-amino-2-methyl-1-propanol; the thickener was hydrophobically modified ethoxy polyurethane; the defoamer was polydimethylsiloxane; the film-forming agent was 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; and the functional additives were n-octyltriethoxysilane and bis(dioctylpyrophosphate) ethylene titanate in a mass ratio of 1:1.

[0063] A solvent-resistant water-based transfer coating is prepared by the following method: Step 1: Heat the modified polyethylene wax emulsion system to 45℃, and add waterborne polyurethane resin dropwise at a stirring rate of 300 rpm over 40 min. After the dropwise addition is complete, continue stirring at the temperature for 30 min. Then add waterborne acrylic emulsion and wetting agent, and at 50℃, control the power at 150W and the frequency at 20KHz, using pulse mode, working for 2 seconds and then pausing for 2 seconds, and ultrasonically disperse for 15 min to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.0, add a thickener, stir at 200 rpm for 40 minutes at 40°C, and then filter once through a 200-mesh filter at a pressure of 0.05 MPa to obtain a thickened and neutralized base material. Step 3: Add crosslinking agent and functional additive to thickening and neutralizing base material at a stirring speed of 500 rpm. Heat the system to 55°C and continue stirring at the temperature for 30 min. Then, add film-forming agent dropwise at a uniform rate over 15 min. After the dropwise addition is complete, let it stand for 10 min. Then, add defoamer and shear disperse at a speed of 1000 rpm for 10 min. Finally, cure for 30 min to obtain composite coating. Step 4: Cool the composite coating system to 30°C, add deionized water, filter through a 350-mesh sieve, and degas for 30 minutes at 30°C and a vacuum of -0.08MPa to obtain a solvent-resistant water-based transfer coating with a viscosity of 80 mPa.s.

[0064] Example 2 A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 30 parts waterborne polyurethane resin, 21 parts waterborne acrylic emulsion, 12 parts modified polyethylene wax emulsion, 0.8 parts crosslinking agent, 0.3 parts wetting agent, 0.5 parts neutralizing agent, 0.4 parts thickener, 0.2 parts defoamer, 0.9 parts film-forming agent, 0.4 parts functional additives, and 23 parts deionized water.

[0065] The modified polyethylene wax emulsion was prepared in Preparation Example 2; the crosslinking agent was trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]; the wetting agent was 2,4,7,9-tetramethyl-5-decyn-4,7-diol; the neutralizing agent was 2-amino-2-methyl-1-propanol; the thickener was hydrophobically modified ethoxy polyurethane; the defoamer was polydimethylsiloxane; the film-forming agent was 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; and the functional additives were n-octyltriethoxysilane and bis(dioctylpyrophosphate)ethylene titanate in a mass ratio of 1:1.5.

[0066] A solvent-resistant water-based transfer coating is prepared by the following method: Step 1: Heat the modified polyethylene wax emulsion system to 48℃, and add waterborne polyurethane resin dropwise at a stirring rate of 400 rpm over 35 min. After the dropwise addition is complete, continue stirring at the temperature for 25 min. Then add waterborne acrylic emulsion and wetting agent, and at 52℃, control the power at 230W and the frequency at 30KHz, using pulse mode, working for 2 seconds and then pausing for 2 seconds, and ultrasonically disperse for 13 min to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.2, add a thickener, stir at 250 rpm for 35 minutes at 43°C, and then filter twice through a 260-mesh filter at a pressure of 0.09 MPa to obtain a thickened and neutralized base material. Step 3: At a stirring speed of 650 rpm, add crosslinking agent and functional additive to thickening and neutralizing base material. Heat the system to 57°C and continue stirring for 25 min. Then, add film-forming agent dropwise at a uniform rate over 18 min. After the dropwise addition is complete, let stand for 12 min. Then add defoamer and shear disperse at a speed of 1100 rpm for 8 min. Finally, cure for 35 min to obtain composite coating. Step 4: Cool the composite coating system to 36℃, add deionized water, filter through a 370-mesh sieve, and degas for 25 minutes at 35℃ and a vacuum of -0.09MPa to obtain a solvent-resistant water-based transfer coating with a viscosity of 90mPa.s.

[0067] Example 3 A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 35 parts waterborne polyurethane resin, 25 parts waterborne acrylic emulsion, 15 parts modified polyethylene wax emulsion, 1.2 parts crosslinking agent, 0.5 parts wetting agent, 0.8 parts neutralizing agent, 0.6 parts thickener, 0.3 parts defoamer, 1.5 parts film-forming agent, 0.6 parts functional additives, and 30 parts deionized water.

[0068] The modified polyethylene wax emulsion was prepared in Preparation Example 3; the crosslinking agent was trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]; the wetting agent was 2,4,7,9-tetramethyl-5-decyn-4,7-diol; the neutralizing agent was 2-amino-2-methyl-1-propanol; the thickener was hydrophobically modified ethoxy polyurethane; the defoamer was polydimethylsiloxane; the film-forming agent was 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; and the functional additives were n-octyltriethoxysilane and bis(dioctylpyrophosphate)ethylene titanate in a mass ratio of 1:2.

[0069] A solvent-resistant water-based transfer coating is prepared by the following method: Step 1: Heat the modified polyethylene wax emulsion system to 50℃, and add waterborne polyurethane resin dropwise at a stirring rate of 500 rpm over 30 min. After the dropwise addition is complete, continue stirring at the temperature for 20 min. Then add waterborne acrylic emulsion and wetting agent, and at 55℃, control the power at 300W and the frequency at 40KHz, using pulse mode, working for 3 seconds and then pausing for 3 seconds, and ultrasonically disperse for 10 min to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.5, add a thickener, stir at 300 rpm for 30 minutes at 45°C, and then filter it three times through a 300-mesh filter at a pressure of 0.15 MPa to obtain a thickened and neutralized base material. Step 3: Add crosslinking agent and functional additive to thickening and neutralizing base material at a stirring speed of 800 rpm. Heat the system to 60°C and continue stirring for 20 min. Then, add film-forming agent dropwise at a uniform rate within 20 min. After the dropwise addition is complete, let it stand for 15 min. Then, add defoamer and shear disperse at a speed of 1200 rpm for 5 min. Finally, cure for 40 min to obtain composite coating. Step 4: Cool the composite coating system to 40℃, add deionized water, filter through a 400-mesh sieve, and degas for 20 minutes at 40℃ and a vacuum of -0.10MPa to obtain a solvent-resistant water-based transfer coating with a viscosity of 100mPa.s.

[0070] To verify the comprehensive performance of the solvent-resistant water-based transfer coating provided by the present invention, comparative examples 1-5 were set up, wherein: Comparative Example 1 Comparative Example 1 is the same as Example 1, except that the modified polyethylene wax emulsion prepared in Preparation Example 1 is replaced with the modified polyethylene wax emulsion prepared in Comparative Preparation Example 1. Specifically: A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 28 parts waterborne polyurethane resin, 18 parts waterborne acrylic emulsion, 10 parts modified polyethylene wax emulsion, 0.3 parts crosslinking agent, 0.2 parts wetting agent, 0.3 parts neutralizing agent, 0.2 parts thickener, 0.1 parts defoamer, 0.5 parts film-forming agent, 0.2 parts functional additives, and 15 parts deionized water.

[0071] The modified polyethylene wax emulsion was prepared from Comparative Preparation Example 1; the crosslinking agent was trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]; the wetting agent was 2,4,7,9-tetramethyl-5-decyn-4,7-diol; the neutralizing agent was 2-amino-2-methyl-1-propanol; the thickener was hydrophobically modified ethoxy polyurethane; the defoamer was polydimethylsiloxane; the film-forming agent was 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; and the functional additives were n-octyltriethoxysilane and bis(dioctylpyrophosphate) ethylene titanate in a mass ratio of 1:1.

[0072] A solvent-resistant water-based transfer coating is prepared by the following method: Step 1: Heat the modified polyethylene wax emulsion system to 45℃, and add waterborne polyurethane resin dropwise at a stirring rate of 300 rpm over 40 min. After the dropwise addition is complete, continue stirring at the temperature for 30 min. Then add waterborne acrylic emulsion and wetting agent, and at 50℃, control the power at 150W and the frequency at 20KHz, using pulse mode, working for 2 seconds and then pausing for 2 seconds, and ultrasonically disperse for 15 min to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.0, add a thickener, stir at 200 rpm for 40 minutes at 40°C, and then filter once through a 200-mesh filter at a pressure of 0.05 MPa to obtain a thickened and neutralized base material. Step 3: Add crosslinking agent and functional additive to thickening and neutralizing base material at a stirring speed of 500 rpm. Heat the system to 55°C and continue stirring at the temperature for 30 min. Then, add film-forming agent dropwise at a uniform rate over 15 min. After the dropwise addition is complete, let it stand for 10 min. Then, add defoamer and shear disperse at a speed of 1000 rpm for 10 min. Finally, cure for 30 min to obtain composite coating. Step 4: Cool the composite coating system to 30°C, add deionized water, filter through a 350-mesh sieve, and degas for 30 minutes at 30°C and a vacuum of -0.08MPa to obtain a solvent-resistant water-based transfer coating with a viscosity of 80 mPa.s.

[0073] Comparative Example 2 Comparative Example 2 is the same as Example 1, except that the modified polyethylene wax emulsion prepared in Preparation Example 1 is replaced with the modified polyethylene wax emulsion prepared in Comparative Preparation Example 2. Specifically: A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 28 parts waterborne polyurethane resin, 18 parts waterborne acrylic emulsion, 10 parts modified polyethylene wax emulsion, 0.3 parts crosslinking agent, 0.2 parts wetting agent, 0.3 parts neutralizing agent, 0.2 parts thickener, 0.1 parts defoamer, 0.5 parts film-forming agent, 0.2 parts functional additives, and 15 parts deionized water.

[0074] The modified polyethylene wax emulsion was prepared from Comparative Preparation Example 2; the crosslinking agent was trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]; the wetting agent was 2,4,7,9-tetramethyl-5-decyn-4,7-diol; the neutralizing agent was 2-amino-2-methyl-1-propanol; the thickener was hydrophobically modified ethoxy polyurethane; the defoamer was polydimethylsiloxane; the film-forming agent was 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; and the functional additives were n-octyltriethoxysilane and bis(dioctylpyrophosphate)ethylene titanate in a mass ratio of 1:1.

[0075] A solvent-resistant water-based transfer coating is prepared by the following method: Step 1: Heat the modified polyethylene wax emulsion system to 45℃, and add waterborne polyurethane resin dropwise at a stirring rate of 300 rpm over 40 min. After the dropwise addition is complete, continue stirring at the temperature for 30 min. Then add waterborne acrylic emulsion and wetting agent, and at 50℃, control the power at 150W and the frequency at 20KHz, using pulse mode, working for 2 seconds and then pausing for 2 seconds, and ultrasonically disperse for 15 min to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.0, add a thickener, stir at 200 rpm for 40 minutes at 40°C, and then filter once through a 200-mesh filter at a pressure of 0.05 MPa to obtain a thickened and neutralized base material. Step 3: Add crosslinking agent and functional additive to thickening and neutralizing base material at a stirring speed of 500 rpm. Heat the system to 55°C and continue stirring at the temperature for 30 min. Then, add film-forming agent dropwise at a uniform rate over 15 min. After the dropwise addition is complete, let it stand for 10 min. Then, add defoamer and shear disperse at a speed of 1000 rpm for 10 min. Finally, cure for 30 min to obtain composite coating. Step 4: Cool the composite coating system to 30°C, add deionized water, filter through a 350-mesh sieve, and degas for 30 minutes at 30°C and a vacuum of -0.08MPa to obtain a solvent-resistant water-based transfer coating with a viscosity of 80 mPa.s.

[0076] Comparative Example 3 Comparative Example 3 is the same as Example 1, except that the modified polyethylene wax emulsion prepared in Preparation Example 1 is replaced with the modified polyethylene wax emulsion prepared in Comparative Preparation Example 3. Specifically: A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 28 parts waterborne polyurethane resin, 18 parts waterborne acrylic emulsion, 10 parts modified polyethylene wax emulsion, 0.3 parts crosslinking agent, 0.2 parts wetting agent, 0.3 parts neutralizing agent, 0.2 parts thickener, 0.1 parts defoamer, 0.5 parts film-forming agent, 0.2 parts functional additives, and 15 parts deionized water.

[0077] The modified polyethylene wax emulsion was prepared in Comparative Preparation Example 3; the crosslinking agent was trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]; the wetting agent was 2,4,7,9-tetramethyl-5-decyn-4,7-diol; the neutralizing agent was 2-amino-2-methyl-1-propanol; the thickener was hydrophobically modified ethoxy polyurethane; the defoamer was polydimethylsiloxane; the film-forming agent was 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; and the functional additives were n-octyltriethoxysilane and bis(dioctylpyrophosphate)ethylene titanate in a mass ratio of 1:1.

[0078] A solvent-resistant water-based transfer coating is prepared by the following method: Step 1: Heat the modified polyethylene wax emulsion system to 45℃, and add waterborne polyurethane resin dropwise at a stirring rate of 300 rpm over 40 min. After the dropwise addition is complete, continue stirring at the temperature for 30 min. Then add waterborne acrylic emulsion and wetting agent, and at 50℃, control the power at 150W and the frequency at 20KHz, using pulse mode, working for 2 seconds and then pausing for 2 seconds, and ultrasonically disperse for 15 min to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.0, add a thickener, stir at 200 rpm for 40 minutes at 40°C, and then filter once through a 200-mesh filter at a pressure of 0.05 MPa to obtain a thickened and neutralized base material. Step 3: Add crosslinking agent and functional additive to thickening and neutralizing base material at a stirring speed of 500 rpm. Heat the system to 55°C and continue stirring at the temperature for 30 min. Then, add film-forming agent dropwise at a uniform rate over 15 min. After the dropwise addition is complete, let it stand for 10 min. Then, add defoamer and shear disperse at a speed of 1000 rpm for 10 min. Finally, cure for 30 min to obtain composite coating. Step 4: Cool the composite coating system to 30°C, add deionized water, filter through a 350-mesh sieve, and degas for 30 minutes at 30°C and a vacuum of -0.08MPa to obtain a solvent-resistant water-based transfer coating with a viscosity of 80 mPa.s.

[0079] Comparative Example 4 Comparative Example 4 is the same as Example 1, except that the functional additive is only n-octyltriethoxysilane. Details are as follows: A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 28 parts waterborne polyurethane resin, 18 parts waterborne acrylic emulsion, 10 parts modified polyethylene wax emulsion, 0.3 parts crosslinking agent, 0.2 parts wetting agent, 0.3 parts neutralizing agent, 0.2 parts thickener, 0.1 parts defoamer, 0.5 parts film-forming agent, 0.2 parts functional additives, and 15 parts deionized water.

[0080] The modified polyethylene wax emulsion was prepared in Preparation Example 1; the crosslinking agent was trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]; the wetting agent was 2,4,7,9-tetramethyl-5-decyn-4,7-diol; the neutralizing agent was 2-amino-2-methyl-1-propanol; the thickener was hydrophobically modified ethoxy polyurethane; the defoamer was polydimethylsiloxane; the film-forming agent was 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; and the functional additive was n-octyltriethoxysilane.

[0081] A solvent-resistant water-based transfer coating is prepared by the following method: Step 1: Heat the modified polyethylene wax emulsion system to 45℃, and add waterborne polyurethane resin dropwise at a stirring rate of 300 rpm over 40 min. After the dropwise addition is complete, continue stirring at the temperature for 30 min. Then add waterborne acrylic emulsion and wetting agent, and at 50℃, control the power at 150W and the frequency at 20KHz, using pulse mode, working for 2 seconds and then pausing for 2 seconds, and ultrasonically disperse for 15 min to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.0, add a thickener, stir at 200 rpm for 40 minutes at 40°C, and then filter once through a 200-mesh filter at a pressure of 0.05 MPa to obtain a thickened and neutralized base material. Step 3: Add crosslinking agent and functional additive to thickening and neutralizing base material at a stirring speed of 500 rpm. Heat the system to 55°C and continue stirring at the temperature for 30 min. Then, add film-forming agent dropwise at a uniform rate over 15 min. After the dropwise addition is complete, let it stand for 10 min. Then, add defoamer and shear disperse at a speed of 1000 rpm for 10 min. Finally, cure for 30 min to obtain composite coating. Step 4: Cool the composite coating system to 30°C, add deionized water, filter through a 350-mesh sieve, and degas for 30 minutes at 30°C and a vacuum of -0.08MPa to obtain a solvent-resistant water-based transfer coating with a viscosity of 80 mPa.s.

[0082] Comparative Example 5 Comparative Example 5 is the same as Example 1, except that the functional additive is only bis(dioctylpyrophosphate)ethylene titanate. Details are as follows: A solvent-resistant waterborne transfer coating comprises the following raw materials in parts by weight: 28 parts waterborne polyurethane resin, 18 parts waterborne acrylic emulsion, 10 parts modified polyethylene wax emulsion, 0.3 parts crosslinking agent, 0.2 parts wetting agent, 0.3 parts neutralizing agent, 0.2 parts thickener, 0.1 parts defoamer, 0.5 parts film-forming agent, 0.2 parts functional additives, and 15 parts deionized water.

[0083] The modified polyethylene wax emulsion was prepared in Preparation Example 1; the crosslinking agent was trimethylolpropane-tris[3-(2-methylaziridinyl)propionate]; the wetting agent was 2,4,7,9-tetramethyl-5-decyn-4,7-diol; the neutralizing agent was 2-amino-2-methyl-1-propanol; the thickener was hydrophobically modified ethoxy polyurethane; the defoamer was polydimethylsiloxane; the film-forming agent was 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; and the functional additive was bis(dioctylpyrophosphate)ethylene titanate.

[0084] A solvent-resistant water-based transfer coating is prepared by the following method: Step 1: Heat the modified polyethylene wax emulsion system to 45℃, and add waterborne polyurethane resin dropwise at a stirring rate of 300 rpm over 40 min. After the dropwise addition is complete, continue stirring at the temperature for 30 min. Then add waterborne acrylic emulsion and wetting agent, and at 50℃, control the power at 150W and the frequency at 20KHz, using pulse mode, working for 2 seconds and then pausing for 2 seconds, and ultrasonically disperse for 15 min to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.0, add a thickener, stir at 200 rpm for 40 minutes at 40°C, and then filter once through a 200-mesh filter at a pressure of 0.05 MPa to obtain a thickened and neutralized base material. Step 3: Add crosslinking agent and functional additive to thickening and neutralizing base material at a stirring speed of 500 rpm. Heat the system to 55°C and continue stirring at the temperature for 30 min. Then, add film-forming agent dropwise at a uniform rate over 15 min. After the dropwise addition is complete, let it stand for 10 min. Then, add defoamer and shear disperse at a speed of 1000 rpm for 10 min. Finally, cure for 30 min to obtain composite coating. Step 4: Cool the composite coating system to 30°C, add deionized water, filter through a 350-mesh sieve, and degas for 30 minutes at 30°C and a vacuum of -0.08MPa to obtain a solvent-resistant water-based transfer coating with a viscosity of 80 mPa.s.

[0085] The comprehensive performance of the solvent-resistant water-based transfer coatings prepared in Examples 1-3 and Comparative Examples 1-5 of this invention was tested respectively.

[0086] 1. Solvent resistance test Referring to GB / T 9274-1988 "Determination of Resistance to Liquid Media for Paints and Varnishes", the solvent-resistant water-based transfer coating prepared in this invention was coated onto the corona-treated surface of a PET film. After drying in a 70°C oven for 3 minutes, it was laminated with coated paper and then peeled off after cooling to room temperature to obtain a transfer coating test sample. The test sample was immersed in 95% ethanol solution and isopropanol solution respectively, and left to stand in a constant temperature water bath at 25°C for 24 hours. The surface condition of the coating was then observed. Referring to GB / T6739-2006 "Determination of Hardness of Paints and Varnishes by Pencil Method", the pencil hardness was recorded before and after immersion by scratching at a 45° angle and a speed of 1 mm / s.

[0087] 2. Transfer peeling performance and surface smoothness test Referring to GB / T 2790-1995 "Test Method for 180° Peel Strength of Adhesives" and GB / T 9754-2007 "Determination of 20°, 60° and 85° Specular Gloss of Paint Films Without Metallic Pigments", the solvent-resistant water-based transfer coating prepared in this invention was transferred onto a 12μm thick corona-treated PET base film using a 200-line ceramic anilox roller. The film was dried in a 60°C forced-air oven for 2 minutes, then laminated with release paper under a pressure of 0.3MPa and cured at 40°C for 48 hours. After curing, a peel test was performed at a 180° angle and a speed of 300mm / min to observe the state of the peeled surface.

[0088] 3. Adhesion and scratch resistance test Referring to GB / T 9286-1998 "Cross-cut test for paint and varnish film" and ASTM D2486-11 "Standard test method for scrub resistance of latex paint", the solvent-resistant water-based transfer coating prepared in this invention was applied to the surface of a glass plate and an ABS plastic substrate. After leveling at room temperature for 5 minutes, it was placed in an 80℃ oven for 30 minutes to form a film with a thickness of 22μm. After the sample cooled to room temperature, a 1mm×1mm grid array was drawn on the coating surface using a cross-cutting knife. The grid was then adhered with 3M 610 tape and immediately peeled off to observe the peeling. At the same time, a 500g weight was applied with 0000# steel wool and rubbed back and forth on the coating surface 50 times to observe the scratches.

[0089] The test results are shown in Table 1-2: Table 1: Solvent resistance, transfer peeling performance, and surface smoothness test data of the solvent-resistant waterborne transfer coatings in Examples 1-3 and Comparative Examples 1-5 Table 2: Adhesion and scratch resistance test data of solvent-resistant water-based transfer coatings in Examples 1-3 and Comparative Examples 1-5 As shown in Table 1-2, the solvent-resistant water-based transfer coatings prepared in Examples 1-3 of this invention exhibit excellent performance in all performance tests. After prolonged immersion in ethanol and isopropanol, the coating surface showed no adverse changes, and the pencil hardness remained at the level before immersion, demonstrating excellent solvent resistance. Simultaneously, its transfer and peeling performance was excellent, with a clean and thorough peeling interface. The coating surface was smooth and glossy. Adhesion on both glass and ABS substrates reached the highest level of 0. It also exhibited strong scratch resistance, effectively resisting scratches.

[0090] As can be seen from Example 1 and Comparative Examples 1, 2, and 3, compared with the modified polyethylene wax emulsion prepared by the complete three-step method in Example 1, the coatings prepared by Comparative Example 1 (lacking the grafting step of N-hydroxymethylacrylamide), Comparative Example 2 (lacking the modification step of γ-glycidyl etheroxypropyltrimethoxysilane), and Comparative Example 3 (lacking the modification step of p-dodecylbenzenesulfonyl chloride) all showed a significant decrease in solvent resistance, adhesion, scratch resistance, and transfer peeling properties. This indicates that the active functional groups introduced by the grafting step provide reaction sites for subsequent modification and are the basis for improving performance. The introduction of the bifunctional groups of silane and sulfonyl chloride plays a key role in enhancing the crosslinking network and improving interfacial compatibility, respectively. The absence of any step will lead to a significant deterioration in the final coating performance.

[0091] As can be seen from Example 1 and Comparative Example 4, the combined use of n-octyltriethoxysilane and bis(dioctylpyrophosphoryloxy)ethylene titanate in the functional additives has a synergistic effect. Comparative Example 4 only uses n-octyltriethoxysilane. Although its coating still has good solvent resistance, it performs poorly in terms of transfer peelability, surface condition and adhesion. Comparative Example 5 only uses bis(dioctylpyrophosphoryloxy)ethylene titanate. Its coating shows severe swelling, whitening and wrinkling after solvent immersion. The hardness decreases significantly and it almost completely loses its solvent resistance.

[0092] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A solvent-resistant water-based transfer coating, characterized in that, The raw materials include the following parts by weight: 28-35 parts of waterborne polyurethane resin, 18-25 parts of waterborne acrylic emulsion, 10-15 parts of modified polyethylene wax emulsion, 0.3-1.2 parts of crosslinking agent, 0.2-0.5 parts of wetting agent, 0.3-0.8 parts of neutralizing agent, 0.2-0.6 parts of thickener, 0.1-0.3 parts of defoamer, 0.5-1.5 parts of film-forming agent, 0.2-0.6 parts of functional additives, and 15-30 parts of deionized water.

2. The solvent-resistant water-based transfer coating according to claim 1, characterized in that, The modified polyethylene wax emulsion is prepared by sequentially oxidizing, grafting, modifying with bifunctional groups, and emulsifying a polyethylene wax emulsion.

3. The solvent-resistant water-based transfer coating according to claim 2, characterized in that, The modified polyethylene wax emulsion is prepared by the following steps: S1. Under stirring, add deionized water to the polyethylene wax emulsion and continue stirring and diluting for 5-10 minutes. Pass the emulsion through an 80-100 mesh filter to obtain a diluted emulsion. Disperse the diluted emulsion ultrasonically at 40-45℃ for 10-15 minutes, then add an oxidant. Under continuous ultrasonic assistance, raise the temperature to 85-90℃ and maintain the temperature for 2-3 hours. After the reaction is complete, cool the system to 45-50℃ and filter it a second time through an 180-200 mesh filter. Adjust the pH value to 7.5-8.5 with an alkaline solution to obtain an oxidized polyethylene wax emulsion. S2. After heating the system to 110-115℃ in a pressurized sealed container, N-hydroxymethylacrylamide is added to the oxidized polyethylene wax emulsion at a uniform rate over 40-60 min under nitrogen protection and stirring. Then, the mixture is stirred continuously at 110-120℃ for 20-30 min, and then the catalyst is added. The temperature is then raised to 120-130℃ and the reaction is maintained for 2-3 h to obtain the grafted modified polyethylene wax emulsion. S3. Cool the system to 90-95℃, add γ-glycidoxypropyltrimethoxysilane to the grafted modified polyethylene wax emulsion, and react for 30-40 min under the alkaline catalytic conditions of the system itself, with stirring and nitrogen protection. Then add p-dodecylbenzenesulfonyl chloride, raise the temperature to 95-100℃, and continue the reaction for 1-2 h. After the reaction is completed, cool the system to 50-60℃ and add an alcohol-water solution. Sonicate the solution for 5-10 min, and filter it through a 160-200 mesh filter to obtain the bifunctional modified polyethylene wax emulsion intermediate. S4. Heat the system to 90-95℃, add the composite emulsifier to the bifunctional modified polyethylene wax emulsion intermediate, stir and disperse for 30-40 minutes, add deionized water at 80-90℃, and homogenize by circulation at 40-50MPa 3-5 times to obtain a crude emulsion; cool the crude emulsion system to 50-55℃, adjust the pH value to 8.0-8.5 with ammonia solution, and then filter through a 180-200 mesh sieve to obtain the modified polyethylene wax emulsion.

4. The solvent-resistant water-based transfer coating according to claim 3, characterized in that, In step S2, the mass ratio of N-hydroxymethylacrylamide to oxidized polyethylene wax emulsion is 1:10-20, wherein the mass of the oxidized polyethylene wax emulsion is based on its solid content.

5. The solvent-resistant water-based transfer coating according to claim 3, characterized in that, In step S3, the mass ratio of the grafted modified polyethylene wax emulsion, γ-glycidyl etheroxypropyltrimethoxysilane, and p-dodecylbenzenesulfonyl chloride is 100:1-3:1-2, wherein the mass of the grafted modified polyethylene wax emulsion is based on its solid content.

6. The solvent-resistant water-based transfer coating according to claim 3, characterized in that, The parameters for ultrasonic processing in step S3 are: power of 300-400W, frequency of 25-40KHz, pulse mode, working time of 2-3s, and interval of 2-4s.

7. The solvent-resistant water-based transfer coating according to claim 3, characterized in that, In step S4, the mass ratio of the bifunctional modified polyethylene wax emulsion intermediate, the composite emulsifier, and the deionized water is 100:3-6:150-250, wherein the mass of the bifunctional modified polyethylene wax emulsion intermediate is based on its solid content.

8. The solvent-resistant water-based transfer coating according to claim 1, characterized in that, The functional additive is a mixture of n-octyltriethoxysilane and bis(dioctylpyrophosphoryloxy)ethylene titanate.

9. The solvent-resistant water-based transfer coating according to claim 8, characterized in that, The functional additives are n-octyltriethoxysilane and bis(dioctylpyrophosphoryloxy)ethylene titanate in a mass ratio of 1:1-2.

10. A method for preparing a solvent-resistant water-based transfer coating according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Heat the modified polyethylene wax emulsion system to 45-50℃, and add waterborne polyurethane resin dropwise at a uniform rate over 30-40 minutes while stirring. After the dropwise addition is complete, continue stirring at the temperature for 20-30 minutes. Then add waterborne acrylic emulsion and wetting agent, and ultrasonically disperse at 50-55℃ for 10-15 minutes to obtain the composite base material. Step 2: Add a neutralizer to the composite base material, adjust the pH value to 8.0–8.5, add a thickener, stir at 40–45℃ for 30–40 minutes, and then filter under pressure through a 200–300 mesh filter 1–3 times to obtain a thickened and neutralized base material. Step 3: While stirring, add crosslinking agent and functional additive to thickening and neutralizing base material. Heat the system to 55-60℃ and continue stirring for 20-30 minutes. Then, add film-forming agent dropwise at a uniform rate over 15-20 minutes. After the dropwise addition is complete, let it stand for 10-15 minutes. Then, add defoamer, shear and disperse for 5-10 minutes, and then cure for 30-40 minutes to obtain composite coating. Step 4: Cool the composite coating system to 30-40℃, add deionized water, filter through a 350-400 mesh sieve, and vacuum degas at 30-40℃ for 20-30 minutes to obtain a solvent-resistant water-based transfer coating with a viscosity of 80-100 mPa.s.

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