A flexible anti-cracking film coating and a method for preparing the same

Abstract

This invention relates to the field of coating technology, specifically disclosing a flexible crack-resistant film coating, comprising component A and component B; the mass ratio of component A to component B is 2-4:1; component A comprises, by mass, 50-120 parts of polyether triol, 10-30 parts of polyether diol, 10-20 parts of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 1-5 parts of triethylenediamine, 1-2 parts of dimethylsiloxane, 5-10 parts of N-hydroxysuccinimide, and 1-1 part of calcium carbonate. 2. Liquid coumarone resin 1-5, plasticizer 10-20, antioxidant 1-2, defoamer 1-2, light stabilizer 1-2, porous protein 5-10; Component B by weight includes: polyether triol 20-40, benzoic acid polyol ester plasticizer 10-20, diphenylmethane diisocyanate 20-40, graphene oxide 2-4, toluene diisocyanate 0.5-0.9, tetraethyl orthosilicate 0.5-1.5, catalyst 1-2.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a flexible crack-resistant film coating and its preparation method. Background Technology

[0002] Paint, when applied to the surface of an object, dries and forms a film, isolating the surface of the object from the environmental medium, thus providing protection and decoration. Paint is applied to the surface of the object to be protected or decorated, forming a firmly adhering, continuous film. It is typically based on resin, oil, or emulsion, with or without pigments and fillers, and with appropriate additives.

[0003] Polyurethane coatings are a commonly used type of coating, widely used as wood coatings, automotive repair coatings, floor coatings, and electronic coatings. Two-component polyurethane coatings have the characteristics of low film-forming temperature, strong adhesion, good abrasion resistance, high hardness, corrosion resistance, and good weather resistance, and are currently widely used.

[0004] However, two-component polyurethane coatings have poor flexibility, tensile strength, and crack resistance, which cannot meet the requirements of high-end buildings and special projects, and urgently need to be addressed. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a flexible crack-resistant coating and its preparation method.

[0006] A flexible crack-resistant film coating includes component A and component B; the mass ratio of component A to component B is 2-4:1.

[0007] Component A, by weight, includes: 50-120 parts of polyether triol, 10-30 parts of polyether diol, 10-20 parts of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 1-5 parts of triethylenediamine, 1-2 parts of dimethylsiloxane, 5-10 parts of N-hydroxysuccinimide, 1-2 parts of calcium carbonate, 1-5 parts of liquid coumarone resin, 10-20 parts of plasticizer, 1-2 parts of antioxidant, 1-2 parts of defoamer, 1-2 parts of light stabilizer, and 5-10 parts of porous protein.

[0008] Component B raw materials include, by weight: 20-40 parts polyether triol, 10-20 parts benzoic acid polyol ester plasticizer, 20-40 parts diphenylmethane diisocyanate, 2-4 parts graphene oxide, 0.5-0.9 parts toluene diisocyanate, 0.5-1.5 parts tetraethyl orthosilicate, and 1-2 parts catalyst.

[0009] Preferably, the plasticizer is at least one of butyl phthalate, methyl epoxide, and tributyl acetylcitrate.

[0010] Preferably, the antioxidant is at least one of antioxidant BHT, antioxidant TNP, antioxidant 264, and antioxidant 1010.

[0011] Preferably, the defoamer is a polyether-modified silicone defoamer.

[0012] Preferably, the light stabilizer is at least one of light stabilizer AM-101, light stabilizer GW-540, and light stabilizer 744.

[0013] Preferably, the porous protein is prepared by the following specific operation: collagen and sodium chloride are added to water and stirred evenly, liquid paraffin is added and stirred, glutaraldehyde and sodium lauroyl glutamate are added, stirred at 85-95℃ for 5-15 minutes, filtered, washed 3 times with deionized water, and vacuum dried.

[0014] More preferably, the mass ratio of collagen, glutaraldehyde, and sodium lauroyl glutamate is 5-14:0.1-1:1-2.

[0015] Preferably, the benzoic acid polyol ester plasticizer is at least one of diethylene glycol dibenzoate, dipropylene glycol dibenzoate, and triethylene glycol dibenzoate.

[0016] Preferably, the catalyst is at least one of dibutyltin dilaurate, stannous octoate, and triethylenediamine.

[0017] The preparation method of the above-mentioned flexible crack-resistant film coating includes the following steps:

[0018] S1. Mix polyether triol, polyether diol, and porous protein evenly, and react under nitrogen protection at 100-120℃ for 1-3 hours. Cool to 50-80℃, add 4,4'-diamino-3,3'-dichlorodiphenylmethane, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, plasticizer, antioxidant, liquid coumarone resin, defoamer, and light stabilizer, and continue stirring for 1-2 hours. Degas under vacuum and cool to room temperature to obtain component A.

[0019] S2. Graphene oxide is dispersed in dichloromethane, toluene diisocyanate is added, and the mixture is stirred at 80-100℃ for 5-10 hours. Tetraethyl orthosilicate is added, hydrochloric acid is added, and stirring is continued for 10-20 minutes. The mixture is then filtered under reduced pressure, washed, and dried under vacuum to obtain pretreated graphene.

[0020] S3. Mix polyether triol, diphenylmethane diisocyanate, and benzoic acid polyol ester plasticizer evenly, stir at 60-70℃ for 10-20 min, heat to 100-120℃ under nitrogen protection, react under vacuum for 1-2 h, cool to 50-60℃, add catalyst and pretreated graphene, stir for 10-20 min, and cool to room temperature to obtain component B.

[0021] Preferably, in S2, the mass fraction of hydrochloric acid is 20-30%.

[0022] Beneficial effects:

[0023] This invention uses collagen and sodium chloride compounded and dissolved in water. With the help of liquid paraffin, glutaraldehyde is used to crosslink and form a porous structure. Then, it is compounded with polyether triol and polyether diol. The two have excellent affinity. At the same time, the porous protein and polyether triol and polyether diol are compounded as film-forming substances. After curing, they form an interwoven network structure of macromolecules, which gives the coating film excellent flexibility and good mechanical properties.

[0024] In the presence of toluene diisocyanate, graphene oxide combines with nano-silica particles on its surface. Then, in combination with the film-forming material, it can bond with oxygen in polyurethane to form an organic-inorganic hybrid structure, making the coating denser. The coating film has excellent tensile strength, impact resistance, and excellent crack resistance.

[0025] This invention combines nano-silica particles with the surface of graphene oxide, which can form a loose, weak three-dimensional network structure with porous proteins. When subjected to shear force, hydrogen bonds are broken, and rheological properties are rapidly improved. After resting, hydrogen bonds are rapidly formed, effectively preventing the precipitation of graphene oxide and calcium carbonate. The dispersion is uniform, and after curing, it not only has good flexibility, but also further enhances tensile strength and impact resistance, resulting in excellent mechanical properties.

[0026] The components of this invention are well matched to produce a good synergistic effect. The resulting coating has good flexibility, excellent impact resistance, good crack resistance, wide applicability, and is easy to apply. Attached Figure Description

[0027] Figure 1 The image shows a comparison of the tensile strength and maximum indentation depth of the coatings prepared using the flexible crack-resistant coatings obtained in Example 5 and Comparative Examples 1-2.

[0028] Figure 2 The diagram shows a comparison of the flexibility and impact resistance of the coatings prepared using the flexible crack-resistant coatings obtained in Example 5 and Comparative Examples 1-2. Detailed Implementation

[0029] The present invention will be further explained below with reference to specific embodiments.

[0030] The liquid coumarone resin used below was purchased from Shandong Mouyao New Materials Co., Ltd., model number HY1289.

[0031] Example 1

[0032] A flexible crack-resistant coating comprises: component A and component B; the mass ratio of component A to component B is 2:1.

[0033] Component A contains the following raw materials: 50 kg of polyether triol, 10 kg of polyether diol, 10 kg of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 1 kg of triethylenediamine, 1 kg of dimethylsiloxane, 5 kg of N-hydroxysuccinimide, 1 kg of calcium carbonate, 1 kg of liquid coumarone resin, 10 kg of butyl phthalate, 1 kg of antioxidant BHT, 1 kg of polyether-modified silicone defoamer, 1 kg of light stabilizer AM-101, and 5 kg of porous protein.

[0034] The porous protein was prepared by the following specific operation: 5 kg of collagen and 1.5 kg of sodium chloride were added to 40 kg of water and stirred evenly. 6 kg of liquid paraffin was added and stirred at 3000 r / min for 20 min. 0.1 kg of glutaraldehyde and 1 kg of sodium lauroyl glutamate were added and stirred at 85℃ for 5 min. The mixture was filtered, washed three times with deionized water, and then vacuum dried.

[0035] Component B raw materials include: 20 kg of polyether triol, 10 kg of diethylene glycol dibenzoate, 20 kg of diphenylmethane diisocyanate, 2 kg of graphene oxide, 0.5 kg of toluene diisocyanate, 0.5 kg of tetraethyl orthosilicate, and 1 kg of stannous octoate.

[0036] The preparation method of the above-mentioned flexible crack-resistant film coating includes the following steps:

[0037] S1. Mix polyether triol, polyether diol, and porous protein evenly. Under nitrogen protection, react under vacuum at 100°C for 1 hour. Cool to 50°C, add diaminodiphenylmethane chloride, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, butyl phthalate, antioxidant BHT, liquid coumarone resin, polyether-modified silicone defoamer, and light stabilizer AM-101. Continue stirring for 1 hour, degas under vacuum, and cool to room temperature to obtain component A.

[0038] S2. Graphene oxide was dispersed in 15 kg of dichloromethane, toluene diisocyanate was added, and the mixture was stirred at 80 °C for 5 h. Tetraethyl orthosilicate was added, and 1 kg of 20% hydrochloric acid was added. The mixture was stirred for 10 min and filtered under reduced pressure. The product was washed once with deionized water and dried under vacuum to obtain pretreated graphene.

[0039] S3. Mix polyether triol, diphenylmethane diisocyanate and diethylene glycol dibenzoate evenly, stir at 60°C for 10 min, raise the temperature to 100°C under nitrogen protection, react under vacuum for 1 h, cool to 50°C, add stannous octoate and pretreated graphene, stir for 10 min, and cool to room temperature to obtain component B.

[0040] Example 2

[0041] A flexible crack-resistant coating comprises: component A and component B; the mass ratio of component A to component B is 4:1.

[0042] Component A raw materials include: 120 kg of polyether triol, 30 kg of polyether diol, 20 kg of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 5 kg of triethylenediamine, 2 kg of dimethylsiloxane, 10 kg of N-hydroxysuccinimide, 2 kg of calcium carbonate, 5 kg of liquid coumarone resin, 20 kg of acetylated tributyl citrate, 2 kg of antioxidant TNP, 2 kg of polyether-modified silicone defoamer, 2 kg of light stabilizer GW-540, and 10 kg of porous protein.

[0043] The porous protein was prepared by the following specific operation: 14 kg of collagen and 2.5 kg of sodium chloride were added to 60 kg of water and stirred evenly. 4 kg of liquid paraffin was added and stirred at 1500 r / min for 30 min. 1 kg of glutaraldehyde and 2 kg of sodium lauroyl glutamate were added and stirred at 95℃ for 15 min. The mixture was then filtered, washed three times with deionized water, and vacuum dried.

[0044] Component B raw materials include: 40 kg of polyether triol, 20 kg of triethylene glycol dibenzoate, 40 kg of diphenylmethane diisocyanate, 4 kg of graphene oxide, 0.9 kg of toluene diisocyanate, 1.5 kg of tetraethyl orthosilicate, and 2 kg of stannous octoate.

[0045] The preparation method of the above-mentioned flexible crack-resistant film coating includes the following steps:

[0046] S1. Mix polyether triol, polyether diol, and porous protein evenly. Under nitrogen protection, react under vacuum at 120°C for 3 hours. Cool to 80°C, add diaminodiphenylmethane chloride, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, tributyl acetyl citrate, antioxidant TNP, liquid coumarone resin, polyether-modified silicone defoamer, and light stabilizer GW-540. Continue stirring for 2 hours, degas under vacuum, and cool to room temperature to obtain component A.

[0047] S2. Graphene oxide was dispersed in 25 kg of dichloromethane, toluene diisocyanate was added, and the mixture was stirred at 100 °C for 10 h. Tetraethyl orthosilicate was added, and 2 kg of 30% hydrochloric acid was added. The mixture was stirred for another 20 min. The mixture was then filtered under reduced pressure, and the product was washed three times with deionized water and dried under vacuum to obtain pretreated graphene.

[0048] S3. Mix polyether triol, diphenylmethane diisocyanate, and triethylene glycol dibenzoate evenly, stir at 70°C for 20 min, raise the temperature to 120°C under nitrogen protection, react under vacuum for 2 h, cool to 60°C, add stannous octoate and pretreated graphene, stir for 20 min, and cool to room temperature to obtain component B.

[0049] Example 3

[0050] A flexible crack-resistant coating comprises: component A and component B; the mass ratio of component A to component B is 2.5:1.

[0051] Component A raw materials include: 100 kg of polyether triol, 15 kg of polyether diol, 18 kg of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 2 kg of triethylenediamine, 1.7 kg of dimethylsiloxane, 7 kg of N-hydroxysuccinimide, 1.7 kg of calcium carbonate, 2 kg of liquid coumarone resin, 17 kg of epoxy fatty acid methyl ester, 1.2 kg of antioxidant 264, 1.7 kg of polyether-modified silicone defoamer, 1.2 kg of light stabilizer 744, and 9 kg of porous protein.

[0052] The porous protein was prepared by the following specific operation: 8 kg of collagen and 2.8 kg of sodium chloride were added to 55 kg of water and stirred evenly. 6 kg of liquid paraffin was added and stirred at 3500 r / min for 40 min. 0.3 kg of glutaraldehyde and 1.7 kg of sodium lauroyl glutamate were added and stirred at 88℃ for 12 min. The mixture was filtered, washed three times with deionized water, and then vacuum dried.

[0053] Component B raw materials include: 25 kg of polyether triol, 18 kg of diethylene glycol dibenzoate, 25 kg of diphenylmethane diisocyanate, 3.5 kg of graphene oxide, 0.6 kg of toluene diisocyanate, 1.2 kg of tetraethyl orthosilicate, and 1.3 kg of triethylenediamine.

[0054] The preparation method of the above-mentioned flexible crack-resistant film coating includes the following steps:

[0055] S1. Mix polyether triol, polyether diol, and porous protein evenly. Under nitrogen protection, react under vacuum at 115°C for 1.5 hours. Cool to 70°C, add diaminodiphenylmethane chloride, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, epoxy fatty acid methyl ester, antioxidant 264, liquid coumarone resin, polyether-modified silicone defoamer, and light stabilizer 744. Continue stirring for 80 minutes, degas under vacuum, and cool to room temperature to obtain component A.

[0056] S2. Graphene oxide was dispersed in 22 kg of dichloromethane, toluene diisocyanate was added, and the mixture was stirred at 85 °C for 9 h. Tetraethyl orthosilicate was added, and 1.3 kg of hydrochloric acid with a mass fraction of 28% was added. The mixture was stirred for 13 min and filtered under reduced pressure. The product was washed twice with deionized water and dried under vacuum to obtain pretreated graphene.

[0057] S3. Mix polyether triol, diphenylmethane diisocyanate and diethylene glycol dibenzoate evenly, stir at 66℃ for 12 min, raise the temperature to 115℃ under nitrogen protection, react under vacuum for 80 min, cool to 58℃, add triethylenediamine and pretreated graphene, stir for 12 min, and cool to room temperature to obtain component B.

[0058] Example 4

[0059] A flexible crack-resistant coating comprises: component A and component B; the mass ratio of component A to component B is 3.65:1.

[0060] Component A raw materials include: 60 kg of polyether triol, 25 kg of polyether diol, 12 kg of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 4 kg of triethylenediamine, 1.3 kg of dimethylsiloxane, 9 kg of N-hydroxysuccinimide, 1.3 kg of calcium carbonate, 4 kg of liquid coumarone resin, 13 kg of butyl phthalate, 1.8 kg of antioxidant 1010, 1.3 kg of polyether-modified silicone defoamer, 1.8 kg of light stabilizer GW-540, and 7 kg of porous protein.

[0061] The porous protein was prepared by the following specific operation: 12 kg of collagen and 1.4 kg of sodium chloride were added to 45 kg of water and stirred evenly. 7.2 kg of liquid paraffin was added and stirred at 5000 r / min for 10 min. 0.7 kg of glutaraldehyde and 1.3 kg of sodium lauroyl glutamate were added and stirred at 92℃ for 8 min. The mixture was filtered, washed three times with deionized water, and then vacuum dried.

[0062] Component B raw materials include: 35 kg of polyether triol, 12 kg of triethylene glycol dibenzoate, 35 kg of diphenylmethane diisocyanate, 2.5 kg of graphene oxide, 0.8 kg of toluene diisocyanate, 0.8 kg of tetraethyl orthosilicate, and 1.7 kg of dibutyltin dilaurate.

[0063] The preparation method of the above-mentioned flexible crack-resistant film coating includes the following steps:

[0064] S1. Mix polyether triol, polyether diol, and porous protein evenly. Under nitrogen protection, react under vacuum at 105℃ for 2.5h. Cool to 60℃, add diaminodiphenylmethane chloride, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, butyl phthalate, antioxidant 1010, liquid coumarone resin, polyether-modified silicone defoamer, and light stabilizer GW-540. Continue stirring for 100min, degas under vacuum, and cool to room temperature to obtain component A.

[0065] S2. Graphene oxide was dispersed in 18 kg of dichloromethane, toluene diisocyanate was added, and the mixture was stirred at 95 °C for 7 h. Tetraethyl orthosilicate was added, and 1.7 kg of hydrochloric acid with a mass fraction of 22% was added and stirred for 17 min. The mixture was filtered under reduced pressure, and the product was washed twice with deionized water and dried under vacuum to obtain pretreated graphene.

[0066] S3. Mix polyether triol, diphenylmethane diisocyanate, and triethylene glycol dibenzoate evenly, stir at 64°C for 18 min, raise the temperature to 105°C under nitrogen protection, react under vacuum for 100 min, cool to 52°C, add dibutyltin dilaurate and pretreated graphene, stir for 18 min, and cool to room temperature to obtain component B.

[0067] Example 5

[0068] A flexible crack-resistant film coating comprises: component A and component B; the mass ratio of component A to component B is 3.17:1.

[0069] Component A raw materials include: 80 kg of polyether triol, 20 kg of polyether diol, 15 kg of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 3 kg of triethylenediamine, 1.5 kg of dimethylsiloxane, 8 kg of N-hydroxysuccinimide, 1.5 kg of calcium carbonate, 3 kg of liquid coumarone resin, 15 kg of acetylated tributyl citrate, 1.5 kg of antioxidant BHT, 1.5 kg of polyether-modified silicone defoamer, 1.5 kg of light stabilizer AM-101, and 8 kg of porous protein.

[0070] The porous protein was prepared by the following specific operation: 10 kg of collagen and 2 kg of sodium chloride were added to 50 kg of water and stirred evenly. 5 kg of liquid paraffin was added and stirred at 2000 r / min for 25 min. 0.5 kg of glutaraldehyde and 1.5 kg of sodium lauroyl glutamate were added and stirred at 90℃ for 10 min. The mixture was then filtered, washed three times with deionized water, and vacuum dried.

[0071] Component B raw materials include: 30 kg of polyether triol, 15 kg of dipropylene glycol dibenzoate, 30 kg of diphenylmethane diisocyanate, 3 kg of graphene oxide, 0.7 kg of toluene diisocyanate, 1 kg of tetraethyl orthosilicate, and 1.5 kg of dibutyltin dilaurate.

[0072] The preparation method of the above-mentioned flexible crack-resistant film coating includes the following steps:

[0073] S1. Mix polyether triol, polyether diol, and porous protein evenly. Under nitrogen protection, react under vacuum at 110℃ for 2 hours. Cool to 65℃, add diaminodiphenylmethane chloride, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, tributyl acetyl citrate, antioxidant BHT, liquid coumarone resin, polyether-modified silicone defoamer, and light stabilizer AM-101. Continue stirring for 90 minutes, degas under vacuum, and cool to room temperature to obtain component A.

[0074] S2. Graphene oxide was dispersed in 20 kg of dichloromethane, toluene diisocyanate was added, and the mixture was stirred at 90 °C for 8 h. Tetraethyl orthosilicate was added, and 1.5 kg of hydrochloric acid with a mass fraction of 25% was added and stirred for 15 min. The mixture was filtered under reduced pressure, and the product was washed twice with deionized water and dried under vacuum to obtain pretreated graphene.

[0075] S3. Mix polyether triol, diphenylmethane diisocyanate and dipropylene glycol dibenzoate evenly, stir at 65°C for 15 min, raise the temperature to 110°C under nitrogen protection, react under vacuum for 90 min, cool to 55°C, add dibutyltin dilaurate and pretreated graphene, stir for 15 min, and cool to room temperature to obtain component B.

[0076] Comparative Example 1

[0077] A flexible crack-resistant film coating comprises: component A and component B; the mass ratio of component A to component B is 3.17:1.

[0078] Component A contains the following raw materials: 80 kg of polyether triol, 20 kg of polyether diol, 15 kg of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 3 kg of triethylenediamine, 1.5 kg of dimethylsiloxane, 8 kg of N-hydroxysuccinimide, 1.5 kg of calcium carbonate, 3 kg of liquid coumarone resin, 15 kg of acetylsuccinate tributyl ester, 1.5 kg of antioxidant BHT, 1.5 kg of polyether-modified silicone defoamer, 1.5 kg of light stabilizer AM-101, and 8 kg of collagen.

[0079] Component B raw materials include: 30 kg of polyether triol, 15 kg of dipropylene glycol dibenzoate, 30 kg of diphenylmethane diisocyanate, 3 kg of graphene oxide, 0.7 kg of toluene diisocyanate, 1 kg of tetraethyl orthosilicate, and 1.5 kg of dibutyltin dilaurate.

[0080] The preparation method of the above-mentioned flexible crack-resistant film coating includes the following steps:

[0081] S1. Mix polyether triol, polyether diol, and collagen evenly. Under nitrogen protection, react under vacuum at 110℃ for 2 hours. Cool to 65℃, add diaminodiphenylmethane chloride, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, tributyl acetyl citrate, antioxidant BHT, liquid coumarone resin, polyether-modified silicone defoamer, and light stabilizer AM-101. Continue stirring for 90 minutes, degas under vacuum, and cool to room temperature to obtain component A.

[0082] S2. Graphene oxide was dispersed in 20 kg of dichloromethane, toluene diisocyanate was added, and the mixture was stirred at 90 °C for 8 h. Tetraethyl orthosilicate was added, and 1.5 kg of hydrochloric acid with a mass fraction of 25% was added and stirred for 15 min. The mixture was filtered under reduced pressure, and the product was washed twice with deionized water and dried under vacuum to obtain pretreated graphene.

[0083] S3. Mix polyether triol, diphenylmethane diisocyanate and dipropylene glycol dibenzoate evenly, stir at 65°C for 15 min, raise the temperature to 110°C under nitrogen protection, react under vacuum for 90 min, cool to 55°C, add dibutyltin dilaurate and pretreated graphene, stir for 15 min, and cool to room temperature to obtain component B.

[0084] Comparative Example 2

[0085] A flexible crack-resistant film coating comprises: component A and component B; the mass ratio of component A to component B is 3.17:1.

[0086] Component A raw materials include: 80 kg of polyether triol, 20 kg of polyether diol, 15 kg of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 3 kg of triethylenediamine, 1.5 kg of dimethylsiloxane, 8 kg of N-hydroxysuccinimide, 1.5 kg of calcium carbonate, 3 kg of liquid coumarone resin, 15 kg of acetylated tributyl citrate, 1.5 kg of antioxidant BHT, 1.5 kg of polyether-modified silicone defoamer, 1.5 kg of light stabilizer AM-101, and 8 kg of porous protein.

[0087] The porous protein was prepared by the following specific operation: 10 kg of collagen and 2 kg of sodium chloride were added to 50 kg of water and stirred evenly. 5 kg of liquid paraffin was added and stirred at 2000 r / min for 25 min. 0.5 kg of glutaraldehyde and 1.5 kg of sodium lauroyl glutamate were added and stirred at 90℃ for 10 min. The mixture was then filtered, washed three times with deionized water, and vacuum dried.

[0088] Component B raw materials include: 30 kg of polyether triol, 15 kg of dipropylene glycol dibenzoate, 30 kg of diphenylmethane diisocyanate, 3 kg of graphene oxide, and 1.5 kg of dibutyltin dilaurate.

[0089] The preparation method of the above-mentioned flexible crack-resistant film coating includes the following steps:

[0090] S1. Mix polyether triol, polyether diol, and porous protein evenly. Under nitrogen protection, react under vacuum at 110℃ for 2 hours. Cool to 65℃, add diaminodiphenylmethane chloride, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, tributyl acetyl citrate, antioxidant BHT, liquid coumarone resin, polyether-modified silicone defoamer, and light stabilizer AM-101. Continue stirring for 90 minutes, degas under vacuum, and cool to room temperature to obtain component A.

[0091] S2. Mix polyether triol, diphenylmethane diisocyanate, and dipropylene glycol dibenzoate evenly, stir at 65°C for 15 min, raise the temperature to 110°C under nitrogen protection, react under vacuum for 90 min, cool to 55°C, add dibutyltin dilaurate and graphene oxide, stir for 15 min, and cool to room temperature to obtain component B.

[0092] The A and B components of the flexible crack-resistant coatings obtained in Example 5 and Comparative Examples 1-2 were mixed evenly and coated onto the surface of tinplate sheets to obtain a coating film with a thickness of 30±5 μm. The tensile strength of each group of coatings was determined according to GB / T 1040.1-2018 "Determination of Tensile Properties of Plastics Part 1: General Rules". The crack resistance of each group of coatings was determined according to GB / T 9753-2007 "Cupping Test for Paints and Varnishes". The flexibility of each group of coatings was determined according to GB / T 1731-2020 "Determination of Flexibility of Paint Films and Putty Films". The impact resistance of each group of coatings was determined according to GB / T 1732-2020 "Determination of Impact Resistance of Paint Films".

[0093] like Figure 1 and Figure 2As shown, the coating film prepared using the flexible anti-crack film coating obtained in Example 5 has the highest tensile strength, the largest maximum indentation depth in the cupping test, can pass through the shaft 7 in the flexibility test, and has the highest impact resistance height, which is better than Comparative Examples 1-2 (P<0.05).

[0094] This application argues that the invention utilizes collagen dissolved in water, then cross-linked with glutaraldehyde to form a porous structure, which is then compounded with polyether triol and polyether diol. The two components exhibit excellent affinity, and the porous protein, combined with the polyether triol and polyether diol, serves as a film-forming substance. After curing, this forms an interwoven network of macromolecules, imparting excellent flexibility to the coating. Furthermore, graphene oxide, in conjunction with toluene diisocyanate, binds nano-silica particles to its surface. This, combined with the film-forming substance, allows it to bond with oxygen in the polyurethane, forming an organic-inorganic hybrid structure. This results in a denser coating with excellent tensile strength, impact resistance, and crack resistance. Meanwhile, this invention combines nano-silica particles on the surface of graphene oxide, which can form a loose, weak three-dimensional network structure with porous proteins. When subjected to shear force, hydrogen bonds are broken, and rheological properties are rapidly improved. After resting, hydrogen bonds are rapidly generated, effectively preventing the precipitation of graphene oxide and calcium carbonate. The dispersion is uniform, and after curing, it not only has good flexibility, but also further enhances tensile strength and impact resistance, resulting in excellent mechanical properties.

[0095] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A flexible crack-resistant film coating, characterized in that, It includes component A and component B; the mass ratio of component A to component B is 2-4:1; Component A, by weight, includes: 50-120 parts of polyether triol, 10-30 parts of polyether diol, 10-20 parts of 4,4'-diamino-3,3'-dichlorodiphenylmethane, 1-5 parts of triethylenediamine, 1-2 parts of dimethylsiloxane, 5-10 parts of N-hydroxysuccinimide, 1-2 parts of calcium carbonate, 1-5 parts of liquid coumarone resin, 10-20 parts of plasticizer, 1-2 parts of antioxidant, 1-2 parts of defoamer, 1-2 parts of light stabilizer, and 5-10 parts of porous protein. Component B raw materials include, by weight: 20-40 parts polyether triol, 10-20 parts benzoic acid polyol ester plasticizer, 20-40 parts diphenylmethane diisocyanate, 2-4 parts graphene oxide, 0.5-0.9 parts toluene diisocyanate, 0.5-1.5 parts tetraethyl orthosilicate, and 1-2 parts catalyst. Porous proteins are prepared by the following specific steps: Collagen and sodium chloride are added to water and stirred evenly. Liquid paraffin is added and stirred. Glutaraldehyde and sodium lauroyl glutamate are added and stirred at 85-95℃ for 5-15 minutes. The mixture is then filtered, washed with deionized water, and vacuum dried.

2. The flexible crack-resistant coating according to claim 1, characterized in that, The plasticizer is at least one of butyl phthalate, methyl epoxide fatty acid ester, and tributyl acetylacetate.

3. The flexible crack-resistant film coating according to claim 1, characterized in that, The antioxidant is at least one of the following: antioxidant BHT, antioxidant TNP, antioxidant 264, and antioxidant 1010.

4. The flexible crack-resistant coating according to claim 1, characterized in that, The defoamer is a polyether-modified silicone defoamer.

5. The flexible crack-resistant coating according to claim 1, characterized in that, The light stabilizer is at least one of the following: light stabilizer AM-101, light stabilizer GW-540, and light stabilizer 744.

6. The flexible crack-resistant coating according to claim 1, characterized in that, The mass ratio of collagen, glutaraldehyde, and sodium lauroyl glutamate is 5-14:0.1-1:1-2.

7. The flexible crack-resistant film coating according to claim 1, characterized in that, The benzoic acid polyol ester plasticizer is at least one of diethylene glycol dibenzoate, dipropylene glycol dibenzoate, and triethylene glycol dibenzoate.

8. The flexible crack-resistant coating according to claim 1, characterized in that, The catalyst is at least one of dibutyltin dilaurate, stannous octoate, and triethylenediamine.

9. A method for preparing a flexible crack-resistant film coating as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Mix polyether triol, polyether diol, and porous protein evenly, and react under nitrogen protection at 100-120℃ for 1-3 hours. Cool to 50-80℃, add 4,4'-diamino-3,3'-dichlorodiphenylmethane, triethylenediamine, dimethylsiloxane, N-hydroxysuccinimide, calcium carbonate, plasticizer, antioxidant, liquid coumarone resin, defoamer, and light stabilizer, and continue stirring for 1-2 hours. Degas under vacuum and cool to room temperature to obtain component A. S2. Graphene oxide is dispersed in dichloromethane, toluene diisocyanate is added, and the mixture is stirred at 80-100℃ for 5-10 hours. Tetraethyl orthosilicate is added, hydrochloric acid is added, and stirring is continued for 10-20 minutes. The mixture is then filtered under reduced pressure, washed, and dried under vacuum to obtain pretreated graphene. S3. Mix polyether triol, diphenylmethane diisocyanate, and benzoic acid polyol ester plasticizer evenly, stir at 60-70℃ for 10-20 min, heat to 100-120℃ under nitrogen protection, react under vacuum for 1-2 h, cool to 50-60℃, add catalyst and pretreated graphene, stir for 10-20 min, and cool to room temperature to obtain component B.

Images