Resin composite liquid with dual self-repairing and high ethanol solvent wiping resistance as well as preparation method and application of resin composite liquid

Abstract

The invention discloses resin composite liquid with dual self-repairing and high ethanol solvent wiping resistance as well as a preparation method and application of the resin composite liquid, and belongs to the technical field of polyurethane emulsion coatings. Aiming at the problems that an existing waterborne polyurethane coating is poor in ethanol resistance due to residual carboxyl / hydroxyl of a hydrophilic chain extender and the self-repairing efficiency of a single dynamic bond is low, a metal ion buffer solution is added into a hydroxyl-terminated polyurethane emulsion to coordinate with the carboxyl of the hydrophilic chain extender, so that a hydrophilic group is closed, and the crosslinking density is increased; meanwhile, a boric acid compound is introduced to form dynamic boric acid ester bonds with residual hydroxyl groups of the system, and hydrophilic groups in the system are consumed while a dual self-repairing network is constructed. The coating prepared by the invention has good self-repairing and ethanol wiping resistance.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a resin combination liquid with dual self-healing and high resistance to ethanol solvent wiping properties, its preparation method, and its application. Background Technology

[0002] Waterborne polyurethane is a polyurethane system that uses water as a solvent or dispersion medium, offering advantages such as environmental friendliness, safety, and zero pollution. It is composed of polymers such as polyethers and polyesters as the main chain, reacted with reactants such as isocyanates. It has a wide range of applications, including coatings, adhesives, textile coatings, leather finishing agents, and paper surface treatment agents. Self-healing properties are crucial for waterborne polyurethane, enabling the material to automatically repair itself after damage, extending its service life and reducing maintenance costs. This is especially important in coating and adhesive applications, maintaining the integrity and functionality of the material. Furthermore, resistance to ethanol wipes ensures that waterborne polyurethane maintains stable physical and chemical properties when wiped with common solvents such as ethanol. This is significant for surfaces requiring frequent cleaning and disinfection, such as medical and electronic equipment, helping to maintain the material's protective and decorative effects. However, due to the inherent molecular structure and stability of polyurethane, currently available waterborne polyurethane coatings lack both self-healing and ethanol-resistant properties.

[0003] In the existing technology, the commonly used polyurethane preparation process often amplifies the defects of polyurethane in terms of ethanol resistance. The hydrophilic groups introduced in the preparation process increase the polarity of polyurethane, resulting in insufficient tolerance to solvents such as water and ethanol, which limits its application scenarios in coatings. Summary of the Invention

[0004] In view of the fact that polyurethane coatings in the prior art are easily corroded by ethanol and generally do not have self-healing properties, the present invention provides a resin combination liquid with dual self-healing and high resistance to ethanol solvent wiping, as well as its preparation method and application.

[0005] This invention introduces a metal ion buffer solution into a hydroxyl-terminated polyurethane emulsion to coordinate with the carboxyl groups of a hydrophilic chain extender, thereby blocking hydrophilic groups and increasing crosslinking density. Simultaneously, a boric acid compound is introduced to form dynamic borate ester bonds with the remaining hydroxyl groups in the system, constructing a dual self-healing network while consuming the hydrophilic groups within the system.

[0006] One of the technical solutions of the present invention is to provide a resin combination liquid with dual self-healing and high resistance to ethanol solvent wiping performance, comprising the following components: a total of 100 parts by weight, wherein 40-60 parts are self-healing ethanol-resistant resin, 4-6 parts are crosslinking agent, 5-8 parts are pigments and fillers, 0.3-0.8 parts are rheology modifier, 1-2 parts are surfactant, 1-2 parts are film-forming aid, 0.1-0.3 parts are defoamer, and the remainder is water.

[0007] The self-healing ethanol-resistant wipe-off resin is prepared by adding a metal ion buffer solution and a substance containing boric acid groups. The metal ion buffer solution includes Cu. 2+ Zn 2+ Fe 3+ Mn 2+ The solution is one or more of a phosphate buffer solution (pH=7.3-8.2) and a Tris-HCl buffer solution (pH=7.5-8.3); wherein the concentration of the metal ion is 0.1-1 mol / L; the substance with the boric acid group includes one or more of 4-hydroxyphenylboronic acid, 3-hydroxyphenylboronic acid, 3-aminophenylboronic acid, 3-hydroxymethylphenylboronic acid, and 4-hydroxymethylphenylboronic acid.

[0008] The structure of the self-healing, ethanol-resistant wipe-resistant resin emulsion is as follows: R1 comes from a hydrophilic chain extender, R2 comes from a substance with a boric acid group, R3 is a polymeric segment obtained from isocyanate and diol under the action of the chain extender, and m is determined by the amount of feed, wherein the mass ratio of diol to isocyanate is 100:(35-40). The metal ions undergo a coordination reaction with the hydrophilic groups on the hydrophilic chain extender to form a dynamically reversible metal-ligand coordination bond.

[0009] The preparation method of the self-healing ethanol-resistant wiping resin is as follows: S1) After mixing the diol and diisocyanate monomer in the diluent, the catalyst is added and reacted at 65℃-75℃ for 2-4 hours. Then, the hydrophilic chain extender and dihydroxy chain extender are added and reacted at 65℃-75℃ for 2-4 hours to extend the chain. After the chain extension reaction is completed, a neutralizing agent is added to neutralize the chain, and then deionized water is added to emulsify the chain. S2) Add a metal ion buffer solution to the product obtained in S1), stir thoroughly, and react at 35℃-55℃ for 0.5-3h. Add a substance with boric acid group, and continue stirring at 35℃-55℃ for 1-3h. S3) Remove the diluent from the product of S2) to obtain a self-healing ethanol-resistant wiping resin.

[0010] Furthermore, the diol has a molecular weight of 1000~3000 kDa and includes one or more of polyether diols, polyester diols, polycarbonate diols, or copolymers thereof.

[0011] Furthermore, the diisocyanate monomer includes one or more of isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and hexamethylene diisocyanate (HDI).

[0012] Further, the hydrophilic chain extender includes one or more of 2,2-dimethylolpropionic acid (DMPA) and 2,2-dimethylolbutyric acid (DMBA); the dihydroxy chain extender includes one or more of butanediol (BG), propylene glycol (PG), ethylene glycol (EG), and glycerol (Gly); the catalyst includes one or more of organotin and organobismuth catalysts; the neutralizing agent includes one or more of triethylamine, trimethylamine, and sodium hydroxide; and the diluent includes one or more of acetone, methyl ethyl ketone, toluene, xylene, ethyl acetate, and butyl acetate.

[0013] Furthermore, the mass ratio of the diol, dicyanate monomer, catalyst, hydrophilic chain extender, dihydroxy chain extender, neutralizer, diluent, deionized water, metal ion buffer solution, and substance with boric acid group is 100: (35-40): (0.1-0.2): (8-11): (5-10): (8-12): (50-80): (250-400): (30-60): (8-18).

[0014] By adding a metal ion buffer solution to the system, a coordination reaction is carried out with the hydrophilic groups on the hydrophilic chain extender, enhancing the degree of cross-linking within the system, introducing self-healing properties, and reducing the hydrophilicity of the hydrophilic chain extender through the coordination reaction. Similarly, adding a substance with boric acid groups to the system cross-links the remaining hydroxyl groups, also introducing self-healing properties and reducing the system's hydrophilicity. This dual self-healing cross-linking network effectively improves the mechanical properties and ethanol corrosion resistance of polyurethane.

[0015] As a common technique in this field, chain extension and emulsification reactions are carried out under stirring conditions. Generally, the stirring speed for emulsification reactions is 600-1000 r / min, while the stirring speed for other reactions such as chain extension and coordination reactions is 150-300 r / min.

[0016] Furthermore, the crosslinking agent includes one or more of aliphatic polyisocyanates, alicyclic polyisocyanates, and modified epoxy resins.

[0017] Further, the pigments and fillers include one or more of nano-silica, mica powder, conductive carbon black, titanium dioxide, and zinc oxide; the rheology modifiers include one or more of acrylic copolymers and polyurea thixotropic agents; the surfactants include one or more of tetradecyl hydroxypropyl sulfobetaine, fatty alcohol polyoxyethylene ether, sodium alkylbenzene sulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, and polyvinyl alcohol; the film-forming aids include one or more of ethylene glycol, propylene glycol, propylene glycol methyl ether, N-methylpyrrolidone, and N-ethylpyrrolidone; and the defoamers include one or more of polydimethylsiloxane, ethylene oxide, isooctyl alcohol, and tributyl phosphate.

[0018] The second technical solution of the present invention is to provide a method for preparing the above-mentioned resin combination liquid, comprising the following steps: (1) Add 30-40 wt% of water, defoamer, and surfactant to a container and heat to 40-50°C. Stir at 500-700 rpm for 10 minutes to form a homogeneous liquid phase. (2) Adjust the rotation speed to 700~1000rpm, add pigments and fillers, then increase the rotation speed to 1200~1500rpm and continue stirring for 20~30min to obtain a pre-dispersed slurry; (3) Cool the pre-dispersed slurry to 30°C, reduce the rotation speed to 400~600 rpm, add the self-healing ethanol-resistant wiping resin, and stir for 10~15 min until completely mixed; (4) After diluting the crosslinking agent and film-forming aid with 5~10wt% of total water, add them to the system at 600rpm and stir for 10min; (5) Pre-swell the rheology modifier with the remaining water for 20 min, add it to the system at 500 rpm, and stir for 15 min until the viscosity is stable; (6) Add the defoamer to the system at 300 rpm and stir for 5 min to obtain the resin mixture.

[0019] The third technical solution of the present invention is to provide the application of the above-mentioned resin combination liquid.

[0020] The resin mixture prepared by this invention can be used as furniture film and floor film.

[0021] The beneficial effects of this invention are as follows: a metal coordination and borate ester crosslinking system is introduced into a hydroxyl-terminated polyurethane system containing a hydrophilic self-emulsifier. While enhancing the crosslinking density inside the polyurethane system, the coordination reaction simultaneously weakens the hydrophilicity of hydroxyl and carboxyl groups, increases the proportion of hydrophobic groups in the molecular chain, and reduces the ability of ethanol molecules to penetrate into the film. This synergistically achieves the purpose of increasing the crosslinking density of the polyurethane and improving the coating's resistance to ethanol wiping. Attached Figure Description

[0022] Figure 1 The results show the self-healing performance test results of the resin combination liquid coatings of Examples 1-3 and Comparative Examples 1-3. Detailed Implementation

[0023] The following examples are provided to further illustrate the present invention and are intended to explain the invention, not to limit its scope. Unless otherwise specified, all figures are expressed in parts by weight and weight percentages.

[0024] Unless otherwise specified, the raw materials used in this invention are all conventional commercially available products; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0025] The embodiments of the present invention will be further described below with reference to several examples.

[0026] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0027] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0028] Example 1 S1: Take polyester diol (M) n =1000 (pre-dehydrated) 100 parts, isophorone diisocyanate 40 parts, organotin catalyst 0.1 parts were added to a four-necked flask and reacted at 70℃ and 150 r / min for 2 h to obtain the first product. 10 parts DMPA and 8 parts butanediol were reacted with the first product at 65℃ and 150 r / min for 4 h, while 80 parts acetone were added for concentration dilution to obtain the second product. The reaction temperature was lowered to 35℃, 11 parts triethylamine were added to neutralize the system, and 250 parts deionized water were added and emulsified at 800 r / min for 15 min to obtain the third product. Cu with pH 7.3 was added to the third product at 35℃. 2+ 30 parts of a 0.1 mol / L metal ion phosphate buffer solution were reacted at 150 r / min and 35 °C for 0.5 h to obtain the fourth product. 8 parts of 4-hydroxyphenylboronic acid were added to the fourth product, and the mixture was reacted at 150 r / min and 55 °C for 3 h to obtain the fifth product. The fifth product was subjected to reduced pressure to remove acetone, yielding the self-healing ethanol-resistant wipe-resistant resin emulsion.

[0029] S2: Add 30% total water, 0.05 parts defoamer, and 1 part surfactant to a container and heat to 40°C. Stir at 700 rpm for 10 minutes to form a homogeneous liquid phase. Adjust the stirring speed to 1000 rpm and slowly add 8 parts pigments and fillers. Then increase the speed to 1200 rpm and continue stirring for 20 minutes to obtain a pre-dispersed slurry. Cool the pre-dispersed slurry to 30°C, reduce the stirring speed to 400 rpm, and slowly add the self-healing ethanol-resistant wipeable resin. Stir for 15 minutes until completely mixed. Dilute 6 parts crosslinking agent and 2 parts film-forming aid with 10% total water and slowly add them to the system at 600 rpm, stirring for 10 minutes. Add 0.3 parts rheology modifier and pre-swell with the remaining water for 20 minutes to the system at 500 rpm and stir for 15 minutes until the viscosity stabilizes. Add 0.15 parts defoamer to the system at 300 rpm and stir for 5 minutes to obtain the resin mixture.

[0030] Example 2 S1: Take polyether diol (M) n =2000 (pre-dehydrated) 100 parts, isophorone diisocyanate 40 parts, and organobismuth catalyst 0.2 parts were added to a four-necked flask and reacted at a reactant temperature of 90℃ and a stirring speed of 150 r / min for 4 h to obtain the first product. 10 parts of DMBA and 5 parts of ethylene glycol were reacted with the first product at a reaction temperature of 65℃ and a stirring speed of 150 r / min for 4 h, while simultaneously adding 80 parts of acetone for concentration dilution to obtain the second product. The reaction temperature was lowered to 35℃, 11 parts of triethylamine were added to neutralize the system, and 250 parts of deionized water were added and emulsified at 800 r / min for 15 min to obtain the third product. Zn at pH 7.5 was added to the third product at 35℃. 2+ 60 parts of a 0.1 mol / L metal ion phosphate buffer solution were reacted at 150 rpm and 35 °C for 3 h to obtain the fourth product. 8 parts of 4-hydroxyphenylboronic acid were added to the fourth product, and the reaction was carried out at 150 rpm and 55 °C for 3 h to obtain the fifth product. The fifth product was subjected to reduced pressure to remove acetone, yielding the polyurethane emulsion.

[0031] S2: Add 40% of the total water, 0.05 parts of defoamer, and 1 part of surfactant to a container and heat to 40°C. Stir at 700 rpm for 10 minutes to form a homogeneous liquid phase. Adjust the stirring speed to 700 rpm and slowly add 8 parts of pigments and fillers. Then increase the stirring speed to 1200 rpm and continue stirring for 30 minutes to obtain a pre-dispersed slurry. Cool the pre-dispersed slurry to 30°C, reduce the stirring speed to 400 rpm, and slowly add the self-healing ethanol-resistant wipeable resin. Stir for 10 minutes until completely mixed. Dilute 6 parts of crosslinking agent and 2 parts of film-forming aid with 5% of the total water, and then slowly add them to the system at 600 rpm and stir for 10 minutes. Add 0.3 parts of rheology modifier and pre-swell with the remaining water for 20 minutes to the system at 500 rpm and stir for 15 minutes until the viscosity stabilizes. Add 0.15 parts of defoamer to the system at 300 rpm and stir for 5 minutes to obtain the resin mixture.

[0032] Example 3 S1: Take polycarbonate diol (M n =2000 (pre-dehydrated) 100 parts, hexamethylene diisocyanate 35 parts, organotin catalyst 0.2 parts were added to a four-necked flask and reacted at 80℃ and 150 r / min for 5 h to obtain the first product. 8 parts of DMPA and 10 parts of butanediol were reacted with the first product at 65℃ and 150 r / min for 4 h, while 50 parts of acetone were added for concentration dilution to obtain the second product. The reaction temperature was lowered to 35℃, 8 parts of triethylamine were added to neutralize the system, and 400 parts of deionized water were added and emulsified at 800 r / min for 15 min to obtain the third product. Fe at pH 7.3 was added to the third product at 35℃. 3+ 50 parts of a 0.1 mol / L metal ion phosphate buffer solution were reacted at 150 rpm and 35 °C for 0.5 h to obtain the fourth product. 18 parts of 4-hydroxyphenylboronic acid were added to the fourth product, and the reaction was carried out at 150 rpm and 35 °C for 3 h to obtain the fifth product. The fifth product was subjected to reduced pressure to remove acetone, yielding the polyurethane emulsion.

[0033] S2: Add 35% total water, 0.15 parts defoamer, and 2 parts surfactant to a container and heat to 50°C. Stir at 700 rpm for 10 minutes to form a homogeneous liquid phase. Adjust the stirring speed to 1000 rpm and slowly add 5 parts pigments and fillers. Then increase the stirring speed to 1500 rpm and continue stirring for 20 minutes to obtain a pre-dispersed slurry. Cool the pre-dispersed slurry to 30°C, reduce the stirring speed to 400 rpm, and slowly add the self-healing ethanol-resistant wipeable resin. Stir for 15 minutes until completely mixed. Dilute 6 parts crosslinking agent and 2 parts film-forming aid with 8% total water and slowly add them to the system at 600 rpm, stirring for 10 minutes. Add 0.8 parts rheology modifier and pre-swell with the remaining water for 20 minutes to the system at 500 rpm and stir for 15 minutes until the viscosity stabilizes. Add 0.12 parts defoamer to the system at 300 rpm and stir for 5 minutes to obtain the resin mixture.

[0034] Comparative Example 1 S1: Take polyester diol (M) n =2000 (pre-dehydrated) 100 parts, isophorone diisocyanate 40 parts, organotin catalyst 0.1 parts were added to a four-necked flask and reacted at a reactant temperature of 70℃ and a stirring speed of 150 r / min for 2 h to obtain the first product. 10 parts of DMPA and 8 parts of butanediol were reacted with the first product at a reaction temperature of 65℃ and a stirring speed of 150 r / min for 4 h. At the same time, 80 parts of acetone were added to dilute the concentration to obtain the second product. The reaction temperature was lowered to 35℃, 11 parts of triethylamine were added to neutralize the system, and 250 parts of deionized water were added. The mixture was emulsified at 800 r / min for 15 min to obtain a polyurethane emulsion.

[0035] S2: Add 30% total water, 0.05 parts defoamer, and 1 part surfactant to a container and heat to 40°C. Stir at 700 rpm for 10 minutes to form a homogeneous liquid phase. Adjust the stirring speed to 1000 rpm and slowly add 8 parts pigments and fillers. Then increase the speed to 1200 rpm and continue stirring for 20 minutes to obtain a pre-dispersed slurry. Cool the pre-dispersed slurry to 30°C, reduce the stirring speed to 400 rpm, and slowly add the self-healing ethanol-resistant wipeable resin. Stir for 15 minutes until completely mixed. Dilute 6 parts crosslinking agent and 2 parts film-forming aid with 10% total water and slowly add them to the system at 600 rpm, stirring for 10 minutes. Add 0.3 parts rheology modifier and pre-swell with the remaining water for 20 minutes to the system at 500 rpm and stir for 15 minutes until the viscosity stabilizes. Add 0.15 parts defoamer to the system at 300 rpm and stir for 5 minutes to obtain the resin mixture.

[0036] Comparative Example 2 S1: Take polyester diol (M)n =1000 (pre-dehydrated) 100 parts, isophorone diisocyanate 40 parts, organotin catalyst 0.1 parts were added to a four-necked flask and reacted at 70℃ and 150 r / min for 2 h to obtain the first product. 10 parts DMPA and 8 parts butanediol were reacted with the first product at 65℃ and 150 r / min for 4 h, while 80 parts acetone were added for concentration dilution to obtain the second product. The reaction temperature was lowered to 35℃, 11 parts triethylamine were added to neutralize the system, and 250 parts deionized water were added and emulsified at 800 r / min for 15 min to obtain the third product. Cu with pH 7.3 was added to the third product at 35℃. 2+ Thirty portions of a metal ion phosphate buffer solution (0.1 mol / L) were reacted at 150 r / min and 35 °C for 0.5 h to obtain a polyurethane emulsion.

[0037] S2: Add 30% total water, 0.05 parts defoamer, and 1 part surfactant to a container and heat to 40°C. Stir at 700 rpm for 10 minutes to form a homogeneous liquid phase. Adjust the stirring speed to 1000 rpm and slowly add 8 parts pigments and fillers. Then increase the speed to 1200 rpm and continue stirring for 20 minutes to obtain a pre-dispersed slurry. Cool the pre-dispersed slurry to 30°C, reduce the stirring speed to 400 rpm, and slowly add the self-healing ethanol-resistant wipeable resin. Stir for 15 minutes until completely mixed. Dilute 6 parts crosslinking agent and 2 parts film-forming aid with 10% total water and slowly add them to the system at 600 rpm, stirring for 10 minutes. Add 0.3 parts rheology modifier and pre-swell with the remaining water for 20 minutes to the system at 500 rpm and stir for 15 minutes until the viscosity stabilizes. Add 0.15 parts defoamer to the system at 300 rpm and stir for 5 minutes to obtain the resin mixture.

[0038] Comparative Example 3 S1: Take polyester diol (M) n=2000 (pre-dehydrated) 100 parts, isophorone diisocyanate 40 parts, organotin catalyst 0.1 parts were added to a four-necked flask and reacted at a reactant temperature of 70℃ and a stirring speed of 150 r / min for 2 h to obtain the first product. 10 parts of DMPA and 8 parts of butanediol were reacted with the first product at a reaction temperature of 65℃ and a stirring speed of 150 r / min for 4 h, while 80 parts of acetone were added for concentration dilution to obtain the second product. The reaction temperature was lowered to 35℃, 11 parts of triethylamine were added to neutralize the system, and 250 parts of deionized water were added and emulsified at 800 r / min for 15 min to obtain the third product. 8 parts of 4-hydroxyphenylboronic acid were added to the third product and reacted at 150 r / min and 55℃ for 3 h to obtain the fifth product. The fifth product was subjected to reduced pressure to remove acetone to obtain the polyurethane emulsion.

[0039] S2: Add 30% total water, 0.05 parts defoamer, and 1 part surfactant to a container and heat to 40°C. Stir at 700 rpm for 10 minutes to form a homogeneous liquid phase. Adjust the stirring speed to 1000 rpm and slowly add 8 parts pigments and fillers. Then increase the speed to 1200 rpm and continue stirring for 20 minutes to obtain a pre-dispersed slurry. Cool the pre-dispersed slurry to 30°C, reduce the stirring speed to 400 rpm, and slowly add the self-healing ethanol-resistant wipeable resin. Stir for 15 minutes until completely mixed. Dilute 6 parts crosslinking agent and 2 parts film-forming aid with 10% total water and slowly add them to the system at 600 rpm, stirring for 10 minutes. Add 0.3 parts rheology modifier and pre-swell with the remaining water for 20 minutes to the system at 500 rpm and stir for 15 minutes until the viscosity stabilizes. Add 0.15 parts defoamer to the system at 300 rpm and stir for 5 minutes to obtain the resin mixture.

[0040] Ethanol Immersion Test The polyurethane emulsions from Examples 1-3 and Comparative Examples 1-3 were uniformly coated into polytetrafluoroethylene molds and dried in an oven at 40°C for 72 h to form polyurethane films. After the films cooled, they were demolded and immersed in a 75 wt% ethanol aqueous solution. The macroscopic morphological changes of the polyurethane films and the overall state of the solution were observed at different time intervals. The experimental results are shown in Table 1.

[0041] Table 1. Test results of ethanol immersion resistance of polyurethane films from Examples 1-3 and Comparative Examples 1-3. Table 1 shows that the polyurethane emulsion with a double internal crosslinking mechanism prepared in this invention can effectively prevent corrosion by ethanol.

[0042] The resin mixtures obtained in Examples 1-3 and Comparative Examples 1-3 were uniformly coated onto a polyvinyl chloride film. The film was heated at 120°C for 3 minutes. After the coating cooled, the samples were subjected to friction tests of different numbers of times using an ethanol-bearing rubbing resistance tester. “√” indicates no damage after a certain number of rubbing cycles, and “×” indicates damage after a certain number of rubbing cycles.

[0043] Table 2. Test results of ethanol friction resistance of resin combination liquid coatings in Examples 1-3 and Comparative Examples 1-3. As shown in Table 2, the dual coordination crosslinking within the polymer and the consumption of hydrophilic groups can effectively enhance the coating's resistance to ethanol wiping.

[0044] Self-repair performance test The resin mixtures obtained in Examples 1-3 and Comparative Examples 1-3 were uniformly coated onto a specially treated polyvinyl chloride film. The film was heated at 120°C for 3 minutes. After cooling, the coating was peeled off, forming a uniform film with a thickness of 0.3 ± 0.02 mm. The film was equilibrated at 25°C and 50% humidity for 48 hours to eliminate residual stress. A 50% depth incision was made in the center region of the dumbbell-shaped film using a scalpel. The incision was aligned, and light pressure was applied with a finger for 2 minutes to ensure interface contact. The film was then placed in an environment of 60°C and 60% humidity for a period of time for repair. Tensile strength was tested after repair and compared with the original sample. like Figure 1As shown, due to the introduction of metal ions and boric acid functionalized components, a dual dynamic crosslinking network was constructed, thus exhibiting excellent self-healing performance. Within 24 hours, all examples achieved near-complete repair, with a repair rate as high as 95%. In contrast, Comparative Examples 1-3, lacking the crucial dynamic crosslinking mechanism, showed a significant decrease in self-healing performance. Even after 24 hours, the repair rate of the comparative examples was still lower than that of the example groups. This demonstrates that the dual self-healing strategy of metal ion bonds and boric acid ester bonds can effectively improve the self-healing performance of the resin composite liquid coating. On one hand, metal ions coordinate with the hydrophilic groups on the hydrophilic chain extender to form dynamically reversible metal-ligand coordination bonds. These bonds can selectively break to dissipate energy under external force or solvent action and recombine after stress relief, achieving autonomous repair of microcracks while simultaneously increasing the crosslinking density and mechanical strength of the coating. On the other hand, the introduced boric acid groups (-B(OH)2) can react with hydroxyl groups in the system to form reversible boric acid ester bonds (BOC). These bonds can undergo hydrolysis and recondensation under certain conditions, further enhancing the self-healing properties of the material. More importantly, the metal coordination bonds and borate ester bonds together construct a dual dynamic network structure: the coordination bonds have a fast response and strong dynamics, which is conducive to rapid repair; the borate ester bonds have high bond energy, providing structural stability and solvent resistance. The synergistic effect of the two not only significantly enhances the crosslinking density and improves the coating's tolerance to repeated ethanol wiping, preventing chalking and peeling, but also achieves highly efficient self-healing function under normal temperature or weak irritation conditions.

[0045] The above embodiments describe in detail the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, shall still fall within the scope of protection of the present invention if they do not exceed the scope covered by the specification.

Claims

1. A resin mixture with dual self-healing properties and high resistance to ethanol solvent wiping, characterized in that, It includes the following components: 40-60 parts by weight of self-healing ethanol-resistant wipe resin, 4-6 parts by weight of crosslinking agent, 5-8 parts by weight of pigments and fillers, 0.3-0.8 parts by weight of rheology modifier, 1-2 parts by weight of surfactant, 1-2 parts by weight of film-forming aid, and 0.1-0.3 parts by weight of defoamer. The self-healing ethanol-resistant wipe-off resin is prepared by adding a metal ion buffer solution and a substance containing boric acid groups. The metal ion buffer solution includes Cu. 2+ Zn 2+ Fe 3+ Mn 2+ The buffer solution contains one or more of the following: phosphate buffer solution (pH=7.3-8.2) and Tris-HCl buffer solution (pH=7.5-8.3); the concentration of metal ions in the metal ion buffer solution is 0.1-1 mol / L; the substance with boric acid group includes one or more of 4-hydroxyphenylboronic acid, 3-hydroxyphenylboronic acid, 3-aminophenylboronic acid, 3-hydroxymethylphenylboronic acid, and 4-hydroxymethylphenylboronic acid.

2. The resin mixture according to claim 1, characterized in that, The preparation method of the self-healing ethanol-resistant wipe resin is as follows: S1) After mixing the diol and diisocyanate monomer in the diluent, the catalyst is added and reacted at 65℃-75℃ for 2-4 hours. Then, the hydrophilic chain extender and dihydroxy chain extender are added and reacted at 65℃-75℃ for 2-4 hours to extend the chain. After the chain extension reaction is completed, a neutralizing agent is added to neutralize the chain, and then deionized water is added to emulsify the chain. S2) Add a metal ion buffer solution to the product obtained in S1), stir thoroughly, and react at 35℃-55℃ for 0.5-3h. Add a substance with boric acid group, and continue stirring at 35℃-55℃ for 1-3h. S3) Remove the diluent from the product of S2) to obtain a self-healing ethanol-resistant wiping resin.

3. The resin mixture according to claim 2, characterized in that, The diol has a molecular weight of 1000~3000 kDa and includes one or more of polyether diol, polyester diol, polycarbonate diol or copolymers thereof.

4. The resin mixture according to claim 2, characterized in that, The diisocyanate monomer includes one or more of isophorone diisocyanate (IPDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and hexamethylene diisocyanate (HDI).

5. The resin mixture according to claim 2, characterized in that, The hydrophilic chain extender includes one or more of 2,2-dimethylolpropionic acid (DMPA) and 2,2-dimethylolbutyric acid (DMBA); the dihydroxy chain extender includes one or more of butanediol (BG), propylene glycol (PG), ethylene glycol (EG), and glycerol (Gly); the catalyst includes one or more of organotin and organobismuth catalysts; the neutralizing agent includes one or more of triethylamine, trimethylamine, and sodium hydroxide; and the diluent includes one or more of acetone, methyl ethyl ketone, toluene, xylene, ethyl acetate, and butyl acetate.

6. The resin mixture according to claim 2, characterized in that, The mass ratio of diol, dicyanate monomer, catalyst, hydrophilic chain extender, dihydroxy chain extender, neutralizer, diluent, deionized water, metal ion buffer solution, and substance with boric acid group is 100: (35-40): (0.1-0.2): (8-11): (5-10): (8-12): (50-80): (250-400): (30-60): (8-18).

7. The resin mixture according to claim 1, characterized in that, The crosslinking agent includes one or more of aliphatic polyisocyanates, alicyclic polyisocyanates, and modified epoxy resins.

8. The resin mixture according to claim 1, characterized in that, The pigments and fillers include one or more of nano-silica, mica powder, conductive carbon black, titanium dioxide, and zinc oxide; the rheology modifiers include one or more of acrylic copolymers and polyurea thixotropic agents; the surfactants include one or more of tetradecyl hydroxypropyl sulfobetaine, fatty alcohol polyoxyethylene ether, sodium alkylbenzene sulfonate, sodium fatty alcohol polyoxyethylene ether sulfate, and polyvinyl alcohol; the film-forming aids include one or more of ethylene glycol, propylene glycol, propylene glycol methyl ether, N-methylpyrrolidone, and N-ethylpyrrolidone; and the defoamers include one or more of polydimethylsiloxane, ethylene oxide, isooctyl alcohol, and tributyl phosphate.

9. A method for preparing the resin mixture as described in claim 1, characterized in that, It includes the following steps: (1) Add 30-40 wt% of water, defoamer, and surfactant to a container and heat to 40-50°C. Stir at 500-700 rpm for 10 minutes to form a homogeneous liquid phase. (2) Adjust the rotation speed to 700~1000rpm, add pigments and fillers, then increase the rotation speed to 1200~1500rpm and continue stirring for 20~30min to obtain a pre-dispersed slurry; (3) Cool the pre-dispersed slurry to 30°C, reduce the rotation speed to 400~600 rpm, add the self-healing ethanol-resistant wiping resin, and stir for 10~15 min until completely mixed; (4) After diluting the crosslinking agent and film-forming aid with 5-10% of the total water, add them to the system at 600 rpm and stir for 10 min; (5) Pre-swell the rheology modifier with water for 20 min, add it to the system at 500 rpm, and stir for 15 min until the viscosity is stable; (6) Add the defoamer to the system at 300 rpm and stir for 5 min to obtain the resin mixture.

10. An application of the resin mixture as described in claim 1.

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