Water-based peelable protective film coating and preparation method thereof

Abstract

The invention relates to the technical field of coating preparation, in particular to a water-based peelable protective film coating and a preparation method thereof.According to the water-based peelable protective film coating, a water-based formula is adopted, pollution to the environment is reduced by reducing use of organic solvents, meanwhile, the influence on human health in the use process is greatly reduced, and the service life of the water-based peelable protective film coating is prolonged. The selection of raw materials and the preparation process pay attention to environmental protection, and conform to the development trend of modern green paint; secondly, through the reasonable proportion of the raw materials and the preparation process, the coating can be easily stripped from the surface of a protected object after forming a protective film, and residues are not left or the protected surface is not damaged; according to the water-based strippable protective film coating prepared by the preparation method disclosed by the invention, through reasonable formula design and selection of high-quality additives such as the coalescing agent and the flatting agent, a uniform, smooth and defect-free film layer can be quickly formed in the coating process of the coating, so that the decoration and protectiveness of the coating are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of water-based coatings, and in particular relates to a water-based peelable protective film coating and a preparation method thereof. Background Art

[0002] In modern industrial production and daily life, such as in footwear, leather goods, packaging and carpets, protective film coatings are widely used as an important auxiliary material for temporary protection of various material surfaces to prevent scratches, contamination or other forms of damage during processing, transportation or storage. Traditional protective film coatings are mostly solvent-based. Although such coatings can provide good protection, they have environmental problems, such as volatile organic compound emissions, which have adverse effects on human health and the environment. Therefore, with the increase of environmental awareness and strict regulations, water-based protective film coatings have gradually become the mainstream of the market.

[0003] Water-based protective film coatings use water as solvent and have the advantages of low organic compound emissions, environmental friendliness, and easy operation. However, existing water-based protective film coatings still have difficulty meeting specific requirements in certain properties, such as peeling performance, weather resistance, and antibacterial performance. In particular, in situations where the protective film needs to be easily peeled off from the surface of the protected material without leaving any residue, higher requirements are placed on the peelability of the coating. Therefore, how to improve the technical defects of traditional water-based peelable coatings so that they have excellent performance on the basis of environmental protection has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] The purpose of the present invention is to provide a water-based peelable protective film coating and a preparation method thereof, which can effectively solve the problems that the protective film coating in the prior art has poor environmental protection effect and the peeling performance, weather resistance and antibacterial performance cannot meet the actual use.

[0005] The purpose of the present invention can be achieved through the following technical solutions: A water-based peelable protective film coating, the water-based peelable protective film coating is composed of the following components: self-emulsifying water-based polyurethane, antibacterial modified silicone-containing styrene-acrylic emulsion, modified silicone oil, modified silica sol, propylene glycol, defoamer, leveling agent, film-forming aid, thickener and triethylamine; The self-emulsifying waterborne polyurethane is prepared with isophorone diisocyanate, polypropylene glycol, dibutyltin dilaurate, dimethylolpropionic acid, 1,4-butanediol, triethylamine and ethylenediamine as raw materials; The antibacterial modified silicon-containing styrene-acrylic emulsion is prepared with styrene, butyl methacrylate, butyl acrylate, acrylic acid, graphite oxide, sodium dodecyl sulfate, p-toluenesulfonic acid, octamethylcyclotetrasiloxane, nonylphenol polyoxyethylene ether, silane coupling agent KH-570 and potassium persulfate as raw materials.

[0006] Furthermore, the preparation steps of the self-emulsifying waterborne polyurethane are: Step 1, add 16-17g of isophorone diisocyanate and 17-18g of polypropylene glycol to a three-necked flask, stir and react at a temperature of 90°C, then cool to 50°C and add 0.3-0.5g of dibutyltin dilaurate, then add 3g of dimethylolpropionic acid and 1g of 1,4-butanediol at a drop rate of 1 drop / s, and continue to react at a constant temperature of 50°C for 2-3h to obtain the reaction system; Step 2: Cool the reaction system to 50°C and add 1.6g of triethylamine. Stir the reaction again, add 0.4g of ethylenediamine and 60g of deionized water and continue the reaction. After vacuum distillation, the obtained product is a self-emulsifying waterborne polyurethane.

[0007] Furthermore, in step 1, the specific operation of stirring the reaction is stirring at a stirring speed of 200 r / min for 2 hours, and the stirring speed for continuing the reaction is 150 r / min. In step 2, the specific operation of stirring the reaction again is stirring at a stirring speed of 300 r / min for 30 minutes, and the specific operation of continuing the reaction is stirring at a stirring speed of 150 r / min for 30 minutes. The specific operation of reduced pressure distillation is reduced pressure distillation at a temperature of 68°C for 2-3 hours.

[0008] Furthermore, the preparation steps of the antibacterial modified silicone-containing styrene-acrylic emulsion are: Step A, weigh 9-10 g of styrene, 9-10 g of butyl methacrylate, 3-4 g of butyl acrylate, 1-2 g of acrylic acid and 0.3-0.5 g of graphite oxide, mix them, and record them as monomer components after mixing evenly; Step B, add 1-2g sodium dodecyl sulfate and 55-60g deionized water to the reaction bottle under nitrogen atmosphere, stir evenly, add 2-3g p-toluenesulfonic acid and continue stirring for 30min, add 4-5g octamethylcyclotetrasiloxane and 3-4g nonylphenol polyoxyethylene ether, heat to 80°C, react at constant temperature for 3h, then cool to 60°C, add 2-3g silane coupling agent KH-570 at a drip rate of 1 drop / s, stir at constant temperature for 30min, heat to 80°C, continue to react for 1h, then cool to 40°C, and the result is recorded as the component to be reacted; Step C, add half of the monomer component to the component to be reacted at a drop rate of 2 drops / s, then raise the temperature to 50°C and add 3-5g of potassium persulfate solution and the remaining monomer component at the original drop rate, raise the temperature to 80°C and keep it warm for 4 hours, then cool it to room temperature, adjust the pH value to 7-8, and obtain an antibacterial modified silicone-containing styrene-acrylic emulsion.

[0009] Furthermore, the specific operation of mixing uniformly in step A is stirring at a stirring speed of 200 r / min for 5 minutes, and in step B, the specific operation of stirring uniformly is stirring at a stirring speed of 500 r / min for 10 minutes, the stirring speed of constant temperature stirring is 300 r / min, the mass fraction of potassium persulfate solution in step C is 10%, and sodium hydroxide solution and hydrochloric acid solution with a mass fraction of 15% are used in step C to adjust the pH.

[0010] Furthermore, the preparation method of the modified silicone oil is: Weigh 15-18g silicone oil and 16-18g allyl polyether into a flask, heat to 60°C, add 5-6g of 20% chloroplatinic acid solution, continue to heat to 90-100°C and keep warm for 2-3h, then cool to 50°C and add 5-6g N-(2-hydroxyethyl)piperazine dropwise. After the addition is completed, continue to react for 2-3h until the solution becomes transparent. After reduced pressure distillation at 65°C for 1-2h, the result is modified silicone oil.

[0011] Furthermore, the preparation steps of the modified silica sol are: Step 1: Weigh 10 g of silane coupling agent KH-560 and dissolve it in 90 g of anhydrous ethanol. Stir at a stirring speed of 500 r / min for 10 min to obtain a dispersion; Step II, weigh 20g of silica sol and pour it into a flask, add 15% sodium hydroxide solution by mass to adjust the pH value to 8, add 5-6g of dispersion at a rate of 1 drop / s under stirring at a stirring speed of 250r / min, and keep warm at 50-60°C for 8h after the addition is completed. The result is the modified silica sol.

[0012] Furthermore, the defoaming agent is polyoxyethylene fatty alcohol ether, and the leveling agent is sodium carboxymethyl cellulose.

[0013] Furthermore, the film-forming aid is dipropylene glycol monomethyl ether, and the thickener is hydroxypropyl methylcellulose.

[0014] A method for preparing a water-based peelable protective film coating, the preparation method comprising: S1, pour 55-60 parts by weight of antibacterial modified silicone-containing styrene-acrylic emulsion into a container with a stirrer, add 30-35 parts by weight of self-emulsifying waterborne polyurethane, 5-6 parts by weight of modified silica sol and 1-2 parts by weight of propylene glycol under stirring conditions of a stirring speed of 600-800r / min, and continue stirring for 10 minutes to obtain a mixed system; S2. Add 0.2-0.5 parts by weight of defoamer and 0.2-0.5 parts by weight of leveling agent to the mixed system, continue stirring for 30 minutes, then add 5-6 parts by weight of modified silicone oil, stir again for 10 minutes, then add 1-5 parts by weight of film-forming aid and 1-2 parts by weight of thickener, and finally adjust the pH value to 7.5-8 with triethylamine to obtain a water-based peelable protective film coating.

[0015] Beneficial effects of the present invention: The self-emulsifying waterborne polyurethane in the present invention has better dispersion stability in water, is not prone to agglomeration or precipitation, and is helpful to obtain a more uniform and stable coating when preparing a strippable coating, thereby improving the overall performance of the coating, and the self-emulsifying waterborne polyurethane can spontaneously emulsify in water without the aid of external force or strong shear force, which can simplify the preparation process and improve production efficiency to a certain extent; secondly, the self-emulsifying waterborne polyurethane has excellent water resistance, can maintain the integrity and performance of the coating in a humid environment, can make the prepared strippable coating have excellent water resistance, and the self-emulsifying waterborne polyurethane does not contain organic solvents, can avoid the pollution of the environment by organic solvents, and meets environmental protection requirements; the present invention adds an antibacterial modified silicon-containing styrene acrylic emulsion to the coating, so that the coating has a certain antibacterial effect while forming a protective film, can effectively prevent the growth of microorganisms such as bacteria and molds, prolong the service life of the protective film, and protect the protected object from the invasion of microorganisms.

[0016] The water-based peelable protective film coating of the present invention adopts a water-based formula, which reduces environmental pollution by reducing the use of organic solvents. At the same time, the impact on human health during use is also greatly reduced, and the selection of raw materials and the preparation process are environmentally friendly, which is in line with the development trend of modern green coatings; secondly, through the reasonable ratio and preparation process between the raw materials, the coating can be easily peeled off from the surface of the protected object after forming a protective film, without leaving residues or damaging the protected surface, and is suitable for various occasions requiring temporary protection; furthermore, the water-based peelable protective film coating prepared by the present invention is designed through a reasonable formula and selected from high-quality film-forming aids, leveling agents and other additives, so that the coating can quickly form a uniform, smooth and defect-free film layer during the coating process, thereby improving the decorativeness and protectiveness of the coating, and can meet the needs of modern industrial production and daily life for temporary protective materials. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1

[0019] A water-based peelable protective film coating, the water-based peelable protective film coating is composed of the following components: self-emulsifying water-based polyurethane, antibacterial modified silicone-containing styrene-acrylic emulsion, modified silicone oil, modified silica sol, propylene glycol, defoamer, leveling agent, film-forming aid, thickener and triethylamine; The self-emulsifying waterborne polyurethane is prepared from isophorone diisocyanate, polypropylene glycol, dibutyltin dilaurate, dimethylolpropionic acid, 1,4-butanediol, triethylamine and ethylenediamine as raw materials. Wherein, the preparation steps of self-emulsifying waterborne polyurethane are: Step 1, add 16g of isophorone diisocyanate and 17g of polypropylene glycol to a three-necked flask, stir at a temperature of 90°C and a stirring speed of 200r / min for 2h to react, cool to 50°C and add 0.3g of dibutyltin dilaurate, then add 3g of dimethylolpropionic acid and 1g of 1,4-butanediol at a dropping rate of 1 drop / s, continue to react at a constant temperature of 50°C and a stirring speed of 150r / min for 2h, and the result is recorded as a reaction system; Step 2: Cool the reaction system to 50°C and add 1.6 g of triethylamine. After stirring at a stirring speed of 300 r / min for 30 min, add 0.4 g of ethylenediamine and 60 g of deionized water and stir at a stirring speed of 150 r / min for 30 min to react. After reduced pressure distillation at a temperature of 68°C for 2 h, the obtained self-emulsifying waterborne polyurethane is obtained.

[0020] The antibacterial modified silicone-containing styrene-acrylic emulsion is prepared from styrene, butyl methacrylate, butyl acrylate, acrylic acid, graphite oxide, sodium dodecyl sulfate, p-toluenesulfonic acid, octamethylcyclotetrasiloxane, nonylphenol polyoxyethylene ether, silane coupling agent KH-570 and potassium persulfate as raw materials. The preparation steps of the antibacterial modified silicone-containing styrene-acrylic emulsion are as follows: Step A, weigh 9 g of styrene, 9 g of butyl methacrylate, 3 g of butyl acrylate, 1 g of acrylic acid and 0.3 g of graphite oxide, mix them, stir them at a stirring speed of 200 r / min for 5 min, and record them as the monomer component; Step B, add 1g of sodium dodecyl sulfate and 55g of deionized water to the reaction bottle under a nitrogen atmosphere, stir at a stirring speed of 500r / min for 10min, add 2g of p-toluenesulfonic acid and continue stirring for 30min, add 4g of octamethylcyclotetrasiloxane and 3g of nonylphenol polyoxyethylene ether, heat to 80°C, stir at a constant temperature of 300r / min for 3h, then cool to 60°C, add 2g of silane coupling agent KH-570 at a dropping rate of 1 drop / s, stir at a constant temperature for 30min, heat to 80°C, continue to react for 1h, then cool to 40°C, and record the result as the component to be reacted; Step C, add half of the monomer component to the component to be reacted at a drop rate of 2 drops / s, then increase the temperature to 50°C and add 3g of 10% potassium persulfate solution and the remaining monomer component at the original drop rate, increase the temperature to 80°C and keep it warm for 4 hours, then cool to room temperature, use 15% sodium hydroxide solution and hydrochloric acid solution to adjust the pH value to 7, and the resulting antibacterial modified silicone-containing styrene acrylic emulsion is obtained.

[0021] The preparation method of modified silicone oil is: Weigh 15g of silicone oil and 16g of allyl polyether into a flask, heat to 60°C, add 5g of 20% chloroplatinic acid solution, continue to heat to 90°C and keep warm for 2h, then cool to 50°C and add 5g of N-(2-hydroxyethyl)piperazine dropwise. After the addition is completed, continue to react for 2h until the solution becomes transparent. After reduced pressure distillation at 65°C for 1h, the result is modified silicone oil.

[0022] The preparation steps of modified silica sol are: Step 1: Weigh 10 g of silane coupling agent KH-560 and dissolve it in 90 g of anhydrous ethanol. Stir at a stirring speed of 500 r / min for 10 min to obtain a dispersion; Step II, weigh 20g of silica sol and pour it into a flask, add 15% sodium hydroxide solution by mass to adjust the pH value to 8, add 5g of dispersion at a rate of 1 drop / s under stirring at a stirring speed of 250r / min, and keep warm at 50°C for 8h after the addition is completed. The result is the modified silica sol.

[0023] The defoaming agent is polyoxyethylene fatty alcohol ether and the leveling agent is sodium carboxymethyl cellulose.

[0024] The film-forming aid is dipropylene glycol monomethyl ether, and the thickener is hydroxypropyl methylcellulose.

[0025] A method for preparing a water-based peelable protective film coating, the preparation method comprising: S1, pour 55 parts by weight of antibacterial modified silicone-containing styrene-acrylic emulsion into a container with a stirrer, add 30 parts by weight of self-emulsifying waterborne polyurethane, 5 parts by weight of modified silica sol and 1 part by weight of propylene glycol under stirring condition of stirring speed of 600r / min, continue stirring for 10min, and the result is recorded as mixed system; S2. Add 0.2 parts by weight of defoamer and 0.2 parts by weight of leveling agent to the mixed system, continue stirring for 30 minutes, then add 5 parts by weight of modified silicone oil, stir again for 10 minutes, then add 1 part by weight of film-forming aid and 1 part by weight of thickener, and finally adjust the pH value to 7.5 with triethylamine to obtain a water-based peelable protective film coating.

[0026] Example 2

[0027] A water-based peelable protective film coating, the water-based peelable protective film coating is composed of the following components: self-emulsifying water-based polyurethane, antibacterial modified silicone-containing styrene-acrylic emulsion, modified silicone oil, modified silica sol, propylene glycol, defoamer, leveling agent, film-forming aid, thickener and triethylamine; The self-emulsifying waterborne polyurethane is prepared from isophorone diisocyanate, polypropylene glycol, dibutyltin dilaurate, dimethylolpropionic acid, 1,4-butanediol, triethylamine and ethylenediamine as raw materials. Wherein, the preparation steps of self-emulsifying waterborne polyurethane are: Step 1, add 17g of isophorone diisocyanate and 18g of polypropylene glycol to a three-necked flask, stir at a temperature of 90°C and a stirring speed of 200r / min for 2h to react, cool to 50°C and add 0.5g of dibutyltin dilaurate, then add 3g of dimethylolpropionic acid and 1g of 1,4-butanediol at a dropping rate of 1 drop / s, continue to react at a constant temperature of 50°C and a stirring speed of 150r / min for 3h, and the result is recorded as a reaction system; Step 2: Cool the reaction system to 50°C and add 1.6 g of triethylamine. After stirring at a stirring speed of 300 r / min for 30 min, add 0.4 g of ethylenediamine and 60 g of deionized water and stir at a stirring speed of 150 r / min for 30 min to react. After reduced pressure distillation at a temperature of 68°C for 3 h, the obtained self-emulsifying waterborne polyurethane is obtained.

[0028] The antibacterial modified silicone-containing styrene-acrylic emulsion is prepared from styrene, butyl methacrylate, butyl acrylate, acrylic acid, graphite oxide, sodium dodecyl sulfate, p-toluenesulfonic acid, octamethylcyclotetrasiloxane, nonylphenol polyoxyethylene ether, silane coupling agent KH-570 and potassium persulfate as raw materials. The preparation steps of the antibacterial modified silicone-containing styrene-acrylic emulsion are as follows: Step A, weighing 10 g of styrene, 10 g of butyl methacrylate, 4 g of butyl acrylate, 2 g of acrylic acid and 0.5 g of graphite oxide, mixing them, stirring at a stirring speed of 200 r / min for 5 min, and recording them as the monomer component; Step B, add 2g of sodium dodecyl sulfate and 60g of deionized water to the reaction bottle under a nitrogen atmosphere, stir at a stirring speed of 500r / min for 10min, add 3g of p-toluenesulfonic acid and continue stirring for 30min, add 5g of octamethylcyclotetrasiloxane and 4g of nonylphenol polyoxyethylene ether, heat to 80°C, stir at a constant temperature of 300r / min for 3h, then cool to 60°C, add 3g of silane coupling agent KH-570 at a dropping rate of 1 drop / s, stir at a constant temperature for 30min, heat to 80°C, continue to react for 1h, then cool to 40°C, and record the result as the component to be reacted; Step C, add half of the monomer component to the component to be reacted at a drop rate of 2 drops / s, then increase the temperature to 50°C and add 5g of a 10% potassium persulfate solution and the remaining monomer component at the original drop rate, increase the temperature to 80°C and keep warm for 4 hours, then cool to room temperature, use a 15% sodium hydroxide solution and a hydrochloric acid solution to adjust the pH value to 8, and obtain an antibacterial modified silicone-containing styrene-acrylic emulsion.

[0029] The preparation method of modified silicone oil is: Weigh 18g of silicone oil and 18g of allyl polyether into a flask, heat to 60°C, add 6g of 20% chloroplatinic acid solution, continue to heat to 100°C and keep warm for 3h, then cool to 50°C and add 6g of N-(2-hydroxyethyl)piperazine dropwise. After the addition is completed, continue to react for 3h until the solution becomes transparent. After reduced pressure distillation at 65°C for 2h, the result is modified silicone oil.

[0030] The preparation steps of modified silica sol are: Step 1: Weigh 10 g of silane coupling agent KH-560 and dissolve it in 90 g of anhydrous ethanol. Stir at a stirring speed of 500 r / min for 10 min to obtain a dispersion; Step II, weigh 20g of silica sol and pour it into a flask, add 15% sodium hydroxide solution by mass to adjust the pH value to 8, add 6g of dispersion at a rate of 1 drop / s under stirring at a stirring speed of 250r / min, and keep warm at 60°C for 8h after the addition is completed. The result is the modified silica sol.

[0031] The defoaming agent is polyoxyethylene fatty alcohol ether and the leveling agent is sodium carboxymethyl cellulose.

[0032] The film-forming aid is dipropylene glycol monomethyl ether, and the thickener is hydroxypropyl methylcellulose.

[0033] A method for preparing a water-based peelable protective film coating, the preparation method comprising: S1, pour 60 parts by weight of antibacterial modified silicone-containing styrene-acrylic emulsion into a container with a stirrer, add 35 parts by weight of self-emulsifying waterborne polyurethane, 6 parts by weight of modified silica sol and 2 parts by weight of propylene glycol under stirring condition of stirring speed of 800r / min, continue stirring for 10min, and record the result as mixed system; S2. Add 0.5 parts by weight of defoamer and 0.5 parts by weight of leveling agent to the mixed system, continue stirring for 30 minutes, then add 6 parts by weight of modified silicone oil, stir again for 10 minutes, then add 5 parts by weight of film-forming aid and 2 parts by weight of thickener, and finally adjust the pH value to 8 with triethylamine to obtain a water-based peelable protective film coating.

[0034] Example 3

[0035] A water-based peelable protective film coating, the water-based peelable protective film coating is composed of the following components: self-emulsifying water-based polyurethane, antibacterial modified silicone-containing styrene-acrylic emulsion, modified silicone oil, modified silica sol, propylene glycol, defoamer, leveling agent, film-forming aid, thickener and triethylamine; The self-emulsifying waterborne polyurethane is prepared from isophorone diisocyanate, polypropylene glycol, dibutyltin dilaurate, dimethylolpropionic acid, 1,4-butanediol, triethylamine and ethylenediamine as raw materials. Wherein, the preparation steps of self-emulsifying waterborne polyurethane are: Step 1, add 17g of isophorone diisocyanate and 17g of polypropylene glycol to a three-necked flask, stir at a temperature of 90°C and a stirring speed of 200r / min for 2h to react, cool to 50°C and add 0.4g of dibutyltin dilaurate, then add 3g of dimethylolpropionic acid and 1g of 1,4-butanediol at a dropping rate of 1 drop / s, continue to react at a constant temperature of 50°C and a stirring speed of 150r / min for 3h, and the result is recorded as a reaction system; Step 2: Cool the reaction system to 50°C and add 1.6 g of triethylamine. After stirring at a stirring speed of 300 r / min for 30 min, add 0.4 g of ethylenediamine and 60 g of deionized water and stir at a stirring speed of 150 r / min for 30 min to react. After reduced pressure distillation at a temperature of 68°C for 3 h, the obtained self-emulsifying waterborne polyurethane is obtained.

[0036] The antibacterial modified silicone-containing styrene-acrylic emulsion is prepared from styrene, butyl methacrylate, butyl acrylate, acrylic acid, graphite oxide, sodium dodecyl sulfate, p-toluenesulfonic acid, octamethylcyclotetrasiloxane, nonylphenol polyoxyethylene ether, silane coupling agent KH-570 and potassium persulfate as raw materials. The preparation steps of the antibacterial modified silicone-containing styrene-acrylic emulsion are as follows: Step A, weigh 9 g of styrene, 10 g of butyl methacrylate, 3 g of butyl acrylate, 1 g of acrylic acid and 0.4 g of graphite oxide, mix them, stir at a stirring speed of 200 r / min for 5 min, and record them as the monomer component; Step B, add 2g of sodium dodecyl sulfate and 58g of deionized water to the reaction bottle under a nitrogen atmosphere, stir at a stirring speed of 500r / min for 10min, add 3g of p-toluenesulfonic acid and continue stirring for 30min, add 5g of octamethylcyclotetrasiloxane and 3g of nonylphenol polyoxyethylene ether, heat to 80°C, stir at a constant temperature of 300r / min for 3h, then cool to 60°C, add 2g of silane coupling agent KH-570 at a drop rate of 1 drop / s, stir at a constant temperature for 30min, heat to 80°C, continue to react for 1h, then cool to 40°C, and record the result as the component to be reacted; Step C, add half of the monomer component to the component to be reacted at a drop rate of 2 drops / s, then increase the temperature to 50°C and add 4g of 10% potassium persulfate solution and the remaining monomer component at the original drop rate, increase the temperature to 80°C and keep warm for 4 hours, then cool to room temperature, use 15% sodium hydroxide solution and hydrochloric acid solution to adjust the pH value to 8, and obtain an antibacterial modified silicone-containing styrene-acrylic emulsion.

[0037] The preparation method of modified silicone oil is: Weigh 17g of silicone oil and 17g of allyl polyether into a flask, heat to 60°C, add 6g of 20% chloroplatinic acid solution, continue to heat to 95°C and keep warm for 3h, then cool to 50°C and add 5g of N-(2-hydroxyethyl)piperazine dropwise. After the addition is completed, continue to react for 3h until the solution becomes transparent. After reduced pressure distillation at 65°C for 2h, the result is modified silicone oil.

[0038] The preparation steps of modified silica sol are: Step 1: Weigh 10 g of silane coupling agent KH-560 and dissolve it in 90 g of anhydrous ethanol. Stir at a stirring speed of 500 r / min for 10 min to obtain a dispersion; Step II, weigh 20g of silica sol and pour it into a flask, add 15% sodium hydroxide solution by mass to adjust the pH value to 8, add 6g of dispersion at a rate of 1 drop / s under stirring at a stirring speed of 250r / min, and keep warm at 55°C for 8h after the addition is completed. The result is the modified silica sol.

[0039] The defoaming agent is polyoxyethylene fatty alcohol ether and the leveling agent is sodium carboxymethyl cellulose.

[0040] The film-forming aid is dipropylene glycol monomethyl ether, and the thickener is hydroxypropyl methylcellulose.

[0041] A method for preparing a water-based peelable protective film coating, the preparation method comprising: S1, pour 58 parts by weight of antibacterial modified silicone-containing styrene-acrylic emulsion into a container with a stirrer, add 33 parts by weight of self-emulsifying waterborne polyurethane, 6 parts by weight of modified silica sol and 1 part by weight of propylene glycol under stirring condition of stirring speed of 700r / min, continue stirring for 10min, and the result is recorded as mixed system; S2. Add 0.4 parts by weight of defoamer and 0.3 parts by weight of leveling agent to the mixed system, continue stirring for 30 minutes, then add 6 parts by weight of modified silicone oil, stir again for 10 minutes, then add 3 parts by weight of film-forming aid and 2 parts by weight of thickener, and finally adjust the pH value to 7.8 with triethylamine to obtain a water-based peelable protective film coating.

[0042] Comparative Example 1 The water-based peelable protective film coating and its preparation method provided in this comparative example are substantially the same as those in Example 1, with the main difference being that in this comparative example 1, the self-emulsifying water-based polyurethane in Example 1 is replaced with a commercially available water-based polyurethane of model 9009-54-5.

[0043] Comparative Example 2 The water-based peelable protective film coating and its preparation method provided in this comparative example are roughly the same as those in Example 1, with the main difference being that in this comparative example 2, the antibacterial modified silicone-containing styrene-acrylic emulsion in Example 1 is replaced with a commercially available styrene-acrylic emulsion of model S-01.

[0044] Comparative Example 3 The water-based peelable protective film coating and the preparation method thereof provided in this comparative example are substantially the same as those in Example 1, with the main difference being that the modified silicone oil in Example 1 is replaced with unmodified silicone oil in this comparative example 3.

[0045] Comparative Example 4 A water-based peelable protective film coating and a preparation method thereof are substantially the same as those in Example 1, with the main difference being that in this comparative example 4, the modified silica sol in Example 1 is replaced with unmodified silica sol.

[0046] Performance Testing The water-based peelable protective film coatings in Examples 1-3 and Comparative Examples 1-4 are marked as Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, respectively. Then, the performance of Examples 1-3 and Comparative Examples 1-4 is tested. The specific test items and test standards are as follows: 1. The peel strength of Examples 1-3 and Comparative Examples 1-4 on glass was tested with reference to GB / T2792-1998 "Test Method for 180° Peel Strength of Pressure-Sensitive Adhesive Tapes", and the obtained data are recorded in Table 1; 2. The water resistance of Examples 1-3 and Comparative Examples 1-4 was tested according to the standard of GB / T1733-93, and the obtained data are recorded in Table 1; 3. The tensile strength of Examples 1-3 and Comparative Examples 1-4 was tested according to the standard of GB / T 528-2009, and the obtained data are recorded in Table 1; 4. The tear strength of Examples 1-3 and Comparative Examples 1-4 was tested according to the standard of GB / T 529-2008, and the obtained data are recorded in Table 1; 5. The antibacterial properties of Examples 1-3 and Comparative Examples 1-4 were tested with reference to GB21866-2008 "Antibacterial Property Determination Method and Antibacterial Effect of Antibacterial Coatings (Paint Films)", and the obtained data are recorded in Table 2; Table 1 Table 2

[0047] It can be seen from the data in the above table that the water-based peelable protective film coatings in Examples 1-3 have better performance than those in Comparative Examples 1-4, and have significantly higher antibacterial properties than Comparative Example 2, indicating that the water-based peelable protective film coatings prepared by the present invention have better market application prospects and promotion value.

[0048] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A water-based peelable protective film coating, characterized in that: The water-based peelable protective film coating is composed of the following components: self-emulsifying water-based polyurethane, antibacterial modified silicone-containing styrene-acrylic emulsion, modified silicone oil, modified silica sol, propylene glycol, defoamer, leveling agent, film-forming aid, thickener and triethylamine; The self-emulsifying waterborne polyurethane is prepared with isophorone diisocyanate, polypropylene glycol, dibutyltin dilaurate, dimethylolpropionic acid, 1,4-butanediol, triethylamine and ethylenediamine as raw materials; The antibacterial modified silicon-containing styrene-acrylic emulsion is prepared with styrene, butyl methacrylate, butyl acrylate, acrylic acid, graphite oxide, sodium dodecyl sulfate, p-toluenesulfonic acid, octamethylcyclotetrasiloxane, nonylphenol polyoxyethylene ether, silane coupling agent KH-570 and potassium persulfate as raw materials.

2. A water-based peelable protective film coating according to claim 1, characterized in that: The preparation steps of the self-emulsifying waterborne polyurethane are: Step 1, add 16-17g of isophorone diisocyanate and 17-18g of polypropylene glycol to a three-necked flask, stir and react at a temperature of 90°C, then cool to 50°C and add 0.3-0.5g of dibutyltin dilaurate, then add 3g of dimethylolpropionic acid and 1g of 1,4-butanediol at a drop rate of 1 drop / s, and continue to react at a constant temperature of 50°C for 2-3h to obtain the reaction system; Step 2: Cool the reaction system to 50°C and add 1.6g of triethylamine. Stir the reaction again, add 0.4g of ethylenediamine and 60g of deionized water and continue the reaction. After vacuum distillation, the obtained product is a self-emulsifying waterborne polyurethane.

3. A water-based peelable protective film coating according to claim 2, characterized in that: In step 1, the specific operation of stirring the reaction is stirring at a stirring speed of 200 r / min for 2 hours, and the stirring speed for continuing the reaction is 150 r / min. In step 2, the specific operation of stirring the reaction again is stirring at a stirring speed of 300 r / min for 30 minutes, and the specific operation of continuing the reaction is stirring at a stirring speed of 150 r / min for 30 minutes. The specific operation of reduced pressure distillation is reduced pressure distillation at a temperature of 68°C for 2-3 hours.

4. The water-based peelable protective film coating according to claim 1, characterized in that: The preparation steps of the antibacterial modified silicone-containing styrene-acrylic emulsion are as follows: Step A, weigh 9-10 g of styrene, 9-10 g of butyl methacrylate, 3-4 g of butyl acrylate, 1-2 g of acrylic acid and 0.3-0.5 g of graphite oxide, mix them, and record them as monomer components after mixing evenly; Step B, add 1-2g sodium dodecyl sulfate and 55-60g deionized water to the reaction bottle under nitrogen atmosphere, stir evenly, add 2-3g p-toluenesulfonic acid and continue stirring for 30min, add 4-5g octamethylcyclotetrasiloxane and 3-4g nonylphenol polyoxyethylene ether, heat to 80°C, react at constant temperature for 3h, then cool to 60°C, add 2-3g silane coupling agent KH-570 at a drip rate of 1 drop / s, stir at constant temperature for 30min, heat to 80°C, continue to react for 1h, then cool to 40°C, and the result is recorded as the component to be reacted; Step C, add half of the monomer component to the component to be reacted at a drop rate of 2 drops / s, then raise the temperature to 50°C and add 3-5g of potassium persulfate solution and the remaining monomer component at the original drop rate, raise the temperature to 80°C and keep it warm for 4 hours, then cool it to room temperature, adjust the pH value to 7-8, and obtain an antibacterial modified silicone-containing styrene-acrylic emulsion.

5. The water-based peelable protective film coating according to claim 4, characterized in that: The specific operation of mixing uniformly in step A is stirring at a stirring speed of 200 r / min for 5 minutes. In step B, the specific operation of stirring uniformly is stirring at a stirring speed of 500 r / min for 10 minutes. The stirring speed of constant temperature stirring is 300 r / min. The mass fraction of potassium persulfate solution in step C is 10%. In step C, sodium hydroxide solution and hydrochloric acid solution with mass fractions of 15% are used to adjust the pH.

6. The water-based peelable protective film coating according to claim 1, characterized in that: The preparation method of the modified silicone oil is: Weigh 15-18g silicone oil and 16-18g allyl polyether into a flask, heat to 60°C, add 5-6g of 20% chloroplatinic acid solution, continue to heat to 90-100°C and keep warm for 2-3h, then cool to 50°C and add 5-6g N-(2-hydroxyethyl)piperazine dropwise. After the addition is completed, continue to react for 2-3h until the solution becomes transparent. After reduced pressure distillation at 65°C for 1-2h, the result is modified silicone oil.

7. The water-based peelable protective film coating according to claim 1, characterized in that: The preparation steps of the modified silica sol are: Step 1: Weigh 10 g of silane coupling agent KH-560 and dissolve it in 90 g of anhydrous ethanol. Stir at a stirring speed of 500 r / min for 10 min to obtain a dispersion; Step II, weigh 20g of silica sol and pour it into a flask, add 15% sodium hydroxide solution by mass to adjust the pH value to 8, add 5-6g of dispersion at a rate of 1 drop / s under stirring at a stirring speed of 250r / min, and keep warm at 50-60°C for 8h after the addition is completed. The result is the modified silica sol.

8. The water-based peelable protective film coating according to claim 1, characterized in that: The defoaming agent is polyoxyethylene fatty alcohol ether, and the leveling agent is sodium carboxymethyl cellulose.

9. The water-based peelable protective film coating according to claim 1, characterized in that: The film-forming aid is dipropylene glycol monomethyl ether, and the thickener is hydroxypropyl methylcellulose.

10. A method for preparing a water-based peelable protective film coating according to any one of claims 1 to 9, characterized in that: The preparation method is: S1, pour 55-60 parts by weight of antibacterial modified silicone-containing styrene-acrylic emulsion into a container with a stirrer, add 30-35 parts by weight of self-emulsifying waterborne polyurethane, 5-6 parts by weight of modified silica sol and 1-2 parts by weight of propylene glycol under stirring conditions of a stirring speed of 600-800r / min, and continue stirring for 10 minutes to obtain a mixed system; S2. Add 0.2-0.5 parts by weight of defoamer and 0.2-0.5 parts by weight of leveling agent to the mixed system, continue stirring for 30 minutes, then add 5-6 parts by weight of modified silicone oil, stir again for 10 minutes, then add 1-5 parts by weight of film-forming aid and 1-2 parts by weight of thickener, and finally adjust the pH value to 7.5-8 with triethylamine to obtain a water-based peelable protective film coating.

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