Self-repairing silicon-based water-based paint and preparation method thereof

Abstract

The invention relates to the technical field of self-repairing coatings, in particular to a self-repairing silicon-based water-based coating and a preparation method thereof. The self-repairing silicon-based water-based paint is prepared from the following raw materials in parts by mass: 5 to 15 parts of water-based fluorine-containing hydroxyl acrylic emulsion, 10 to 20 parts of water-based epoxy resin emulsion, 5 to 15 parts of hydroxyl-terminated polydimethylsiloxane, 1 to 5 parts of activated graphene oxide, 1 to 5 parts of micro-nano silicon dioxide, 1 to 2 parts of catalyst, 5 to 10 parts of methoxytrimethylsilane and 1 to 4 parts of diamino type silane coupling agent. 0.5 to 1.5 parts of amino-terminated polyamidoamine, 10 to 20 parts of aliphatic modified isocyanate curing agent and 0.5 to 1 part of triethylene tetramine. After the coating is damaged, rapid self-healing can be achieved, the coating has good self-repairing performance, and the preparation method is simple and suitable for large-scale application and popularization.

Description

Technical Field

[0001] This invention relates to the field of self-healing coating technology, and in particular to a self-healing silicone-based waterborne coating and its preparation method. Background Technology

[0002] Hydrophobic coatings rely on their inherent hydrophobic physical properties to provide antifouling and easy-to-clean effects, and have extremely wide applications in fields such as corrosion prevention, anti-icing, and photovoltaics. However, in actual use, hydrophobic coatings are inevitably affected by external environmental factors such as chemical corrosion and scratches, which can easily lead to the loss of low surface energy components or the destruction of micro-nano hierarchical structures, resulting in the loss of hydrophobic properties.

[0003] Self-healing coatings refer to organic polymer coatings that possess self-healing capabilities after being damaged, or under certain conditions. Self-healing coatings also have anti-corrosion properties. By mimicking the basic principles of biological self-healing, they enable materials to self-repair internal or external damage, eliminating potential hazards, extending the coating's service life, and achieving long-term anti-corrosion protection for the substrate.

[0004] Currently, microcapsule encapsulation technology is used to encapsulate repair agents. However, once the microcapsules rupture, they cannot regenerate, and the repair agents are easily affected, leading to premature failure. Furthermore, the coating needs to simultaneously improve radiation resistance, scratch resistance, and self-healing properties during service. Although adding hard fillers can increase surface hardness, this often sacrifices the coating's flexibility, causing stress cracks when the coating deforms. Therefore, obtaining coatings that combine waterproofing and self-healing functions presents an excellent research prospect. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a self-healing silicon-based waterborne coating and its preparation method.

[0006] A self-healing silicone-based waterborne coating comprises, by weight, the following raw materials: 5-15 parts of waterborne fluorinated hydroxyl acrylic emulsion, 10-20 parts of waterborne epoxy resin emulsion, 5-15 parts of hydroxyl-terminated polydimethylsiloxane, 1-5 parts of activated graphene oxide, 1-5 parts of micro / nano silica, 1-2 parts of catalyst, 5-10 parts of methoxytrimethylsilane, 1-4 parts of diamino silane coupling agent, 0.5-1.5 parts of hydroxyl-terminated polyamide amine, 10-20 parts of aliphatic modified isocyanate curing agent, and 0.5-1 part of triethylenetetramine.

[0007] Preferably, the catalyst is at least one of zinc octanoate, organotin catalyst, and organobismuth catalyst; more preferably, it is dibutyltin dilaurate.

[0008] Preferably, the diamino silane coupling agent is KH-792 coupling agent.

[0009] Preferably, activated graphene oxide is prepared by the following steps: adding silane coupling agent to an ethanol aqueous solution and stirring until homogeneous; adjusting the pH of the system to 3-4; stirring at 50-60℃ for 1-2 hours; adding graphene oxide and activator and sonicating for 10-30 minutes; heating to 70-80℃ and stirring for 1-3 hours; filtering; washing; and vacuum drying.

[0010] More preferably, the silane coupling agent is coupling agent KH-570; the activator is sodium dodecyl sulfate.

[0011] More preferably, the mass ratio of silane coupling agent, graphene oxide, and activator is 1-3:5-10:0.1-1.

[0012] More preferably, the mass fraction of the ethanol aqueous solution is 50-60%.

[0013] More preferably, the ultrasonic frequency is 70-90kHz.

[0014] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Add methoxytrimethylsilane, diamino silane coupling agent, and amino-terminated polyamide amine to an aqueous ethanol solution, stir at 50-60℃ for 20-40 min, adjust the pH of the system to 2-4, continue stirring for 2-5 h, cool to room temperature, and distill under reduced pressure to obtain the pre-prepared material. S2. Add hydroxyl-terminated polydimethylsiloxane, waterborne fluorinated hydroxyl acrylic emulsion, waterborne epoxy resin emulsion, activated graphene oxide, micro-nano silica, and catalyst to the preform, adjust the solid content to 30-40%, and stir at 40-50℃ for 1-2 hours to obtain component A. S3. Add the aliphatic modified isocyanate curing agent and triethylenetetramine to the solvent and stir at room temperature for 10-30 minutes to obtain component B.

[0015] Preferably, in S1, the pH of the system is adjusted to 2-4 using hydrochloric acid with a concentration of 0.5-1 mol / L.

[0016] Beneficial effects: This invention uses methoxytrimethylsilane and a diamino silane coupling agent to form a siloxane condensation network, on which terminal amino polyamide amines are bound. The product is a polysiloxane structure containing a large number of amino groups, which can cooperate with activated graphene oxide to provide self-healing active sites, enabling rapid self-healing of the coating after damage, and giving the coating good self-healing properties.

[0017] This invention utilizes the dynamic crosslinking of waterborne epoxy resin emulsion with triethylenetetramine, where epoxy groups combine with amine groups to achieve self-healing under thermal stress. Furthermore, this invention utilizes the combination of isocyanate groups in the trimer with the hydroxyl groups of hydroxyl-terminated polydimethylsiloxane to achieve reversible fracture-recombination under environmental stress, thus maintaining the coating's elasticity and achieving damage self-healing, effectively enhancing the coating's self-healing ability.

[0018] This invention utilizes an aqueous fluorinated hydroxyl acrylic emulsion combined with activated graphene oxide. After modification with a coupling agent, the epoxy groups of the graphene oxide form covalent bonds with the resin matrix. The fluorocarbon segments of the aqueous fluorinated hydroxyl acrylic emulsion form a low surface energy surface through hydrophobic interactions. Combined with the effect of layered graphene, the waterproof and corrosion-resistant properties are significantly enhanced. At the same time, the activated graphene oxide and micro / nano silica construct a rough structure, which significantly improves the hydrophobic strength of the coating.

[0019] This invention enables rapid self-healing after coating damage, the coating has good self-repair properties, and the preparation method is simple, making it suitable for large-scale application. Attached Figure Description

[0020] Figure 1 The images show a comparison of the static water contact angle of the self-healing coatings formed using the coatings obtained in Example 5 and Comparative Examples 1-3, and the static water contact angle after artificial climate aging.

[0021] Figure 2 The chart shows a comparison of the self-healing rate of the self-healing coatings formed using the coatings obtained in Example 5 and Comparative Examples 1-3, and the self-healing rate after cyclic treatment. Detailed Implementation

[0022] The present invention will be further explained below with reference to specific embodiments.

[0023] The water-based fluorinated hydroxyl acrylic emulsion used below was purchased from a certain company (Jining) Chemical Technology Co., Ltd., model F-828, with a solid content of 45%. The water-based epoxy resin emulsion used below was sourced from Baling Petrochemical, brand CYDW-102W50. The hydroxyl content was 2.2±0.4%, and the fluorine content was >10%. The hydroxyl-terminated polydimethylsiloxane used below was purchased from Hubei Sheng Sihai New Materials Co., Ltd., with a viscosity of 25-30 cP and a hydroxyl content of 8±1%. The amino-terminated polyamide amine (PAMAM G5-NH2) used below was purchased from Xi'an Yue Biotechnology Co., Ltd. The aliphatic modified isocyanate curing agent used below was sourced from Covestro, model Imprafix 2794XP. The micro / nano silica used below is obtained by mixing nano silica with a particle size of 50-100nm and silica with a particle size of 10-20μm in a mass ratio of 3:1. All silica used was purchased from Weifang Moujia Chemical Co., Ltd.

[0024] Example 1

[0025] A self-healing silicone-based waterborne coating comprises the following raw materials: 10g of waterborne fluorinated hydroxyl acrylic emulsion, 20g of waterborne epoxy resin emulsion, 10g of hydroxyl-terminated polydimethylsiloxane, 2g of activated graphene oxide, 2g of micro / nano silica, 2g of dibutyltin dilaurate, 10g of methoxytrimethylsilane, 2g of KH-792 coupling agent, 1g of amino-terminated polyamide amine, 20g of aliphatic modified isocyanate curing agent, and 1g of triethylenetetramine.

[0026] Activated graphene oxide was prepared by the following steps: 2g of coupling agent KH-570 was added to 60g of 50% ethanol aqueous solution and stirred evenly. The pH of the system was adjusted to 3-4 with 1mol / L hydrochloric acid. The mixture was stirred at 50℃ for 1h. 10g of graphene oxide and 0.2g of sodium dodecyl sulfate were added and ultrasonically treated for 10min at a frequency of 70kHz. The temperature was raised to 70℃ and stirred at 100r / min for 1h. The mixture was then filtered, washed, and vacuum dried.

[0027] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Methoxytrimethylsilane, KH-792 coupling agent, and amino-terminated polyamide amine were added to 40g of 40% ethanol aqueous solution. The mixture was stirred at 50℃ for 20min. The pH of the system was adjusted to 2-4 with 0.5mol / L hydrochloric acid. The mixture was stirred for 2h, cooled to room temperature, and distilled under reduced pressure to obtain the pre-prepared material. S2. Add hydroxyl-terminated polydimethylsiloxane, waterborne fluorinated hydroxyl acrylic emulsion, waterborne epoxy resin emulsion, activated graphene oxide, micro-nano silica, and dibutyltin dilaurate to the preform. Add water until the solid content is 30%. Stir at 40℃ for 1 hour at a stirring speed of 100 r / min to obtain component A. S3. Mix aliphatic modified isocyanate curing agent, triethylenetetramine, and 20g of water, and stir at room temperature for 10min at a stirring speed of 100r / min to obtain component B.

[0028] Example 2

[0029] A self-healing silicone-based waterborne coating comprises the following raw materials: 30g of waterborne fluorinated hydroxyl acrylic emulsion, 40g of waterborne epoxy resin emulsion, 30g of hydroxyl-terminated polydimethylsiloxane, 10g of activated graphene oxide, 10g of micro / nano silica, 4g of dibutyltin dilaurate, 20g of methoxytrimethylsilane, 8g of KH-792 coupling agent, 3g of amino-terminated polyamide amine, 40g of aliphatic modified isocyanate curing agent, and 2g of triethylenetetramine.

[0030] Activated graphene oxide was prepared by the following steps: 6g of coupling agent KH-570 was added to 120g of 60% ethanol aqueous solution and stirred evenly. The pH of the system was adjusted to 3-4 with 2mol / L hydrochloric acid. The mixture was stirred at 60℃ for 2h. 20g of graphene oxide and 2g of sodium dodecyl sulfate were added and ultrasonically treated for 30min at a frequency of 90kHz. The temperature was raised to 80℃ and stirred at 500r / min for 3h. The mixture was then filtered, washed, and vacuum dried.

[0031] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Methoxytrimethylsilane, KH-792 coupling agent, and amino-terminated polyamide amine were added to 80g of 60% ethanol aqueous solution. The mixture was stirred at 60℃ for 40min. The pH of the system was adjusted to 2-4 with 1mol / L hydrochloric acid. The mixture was stirred for 5h, cooled to room temperature, and distilled under reduced pressure to obtain the pre-prepared material. S2. Add hydroxyl-terminated polydimethylsiloxane, waterborne fluorinated hydroxyl acrylic emulsion, waterborne epoxy resin emulsion, activated graphene oxide, micro-nano silica, and dibutyltin dilaurate to the preform. Add water until the solid content is 40%. Stir at 50°C for 2 hours at a stirring speed of 300 r / min to obtain component A. S3. Mix aliphatic modified isocyanate curing agent, triethylenetetramine, and 30g of water, and stir at room temperature for 30min at a stirring speed of 400r / min to obtain component B.

[0032] Example 3

[0033] A self-healing silicone-based waterborne coating comprises the following raw materials: 24g of waterborne fluorinated hydroxyl acrylic emulsion, 24g of waterborne epoxy resin emulsion, 16g of hydroxyl-terminated polydimethylsiloxane, 8g of activated graphene oxide, 4g of micro / nano silica, 3.4g of dibutyltin dilaurate, 14g of methoxytrimethylsilane, 6g of KH-792 coupling agent, 1.5g of amino-terminated polyamide amine, 35g of aliphatic modified isocyanate curing agent, and 1.3g of triethylenetetramine.

[0034] Activated graphene oxide was prepared by the following steps: 5g of coupling agent KH-570 was added to 80g of 58% ethanol aqueous solution and stirred until homogeneous. The pH of the system was adjusted to 3-4 with 1.2mol / L hydrochloric acid. The mixture was stirred at 58℃ for 80min. 18g of graphene oxide and 0.4g of sodium dodecyl sulfate were added and ultrasonically treated for 25min at a frequency of 75kHz. The temperature was raised to 78℃ and stirred at 200r / min for 2.5h. The mixture was then filtered, washed, and vacuum dried.

[0035] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Methoxytrimethylsilane, KH-792 coupling agent, and amino-terminated polyamide amine were added to 50g of 55% ethanol aqueous solution. The mixture was stirred at 52℃ for 35min. The pH of the system was adjusted to 2-4 with 0.7mol / L hydrochloric acid. The mixture was stirred for 4h, cooled to room temperature, and distilled under reduced pressure to obtain the pre-prepared material. S2. Add hydroxyl-terminated polydimethylsiloxane, waterborne fluorinated hydroxyl acrylic emulsion, waterborne epoxy resin emulsion, activated graphene oxide, micro-nano silica, and dibutyltin dilaurate to the preform. Add water until the solid content is 33%. Stir at 48℃ for 80 min at a stirring speed of 260 r / min to obtain component A. S3. Mix aliphatic modified isocyanate curing agent, triethylenetetramine, and 25g of water, and stir at room temperature for 25min at a stirring speed of 200r / min to obtain component B.

[0036] Example 4

[0037] A self-healing silicone-based waterborne coating comprises the following raw materials: 16g of waterborne fluorinated hydroxyl acrylic emulsion, 36g of waterborne epoxy resin emulsion, 24g of hydroxyl-terminated polydimethylsiloxane, 4g of activated graphene oxide, 8g of micro / nano silica, 2.6g of dibutyltin dilaurate, 18g of methoxytrimethylsilane, 4g of KH-792 coupling agent, 2.5g of amino-terminated polyamide amine, 25g of aliphatic modified isocyanate curing agent, and 1.7g of triethylenetetramine.

[0038] Activated graphene oxide was prepared using the following steps: 3g of coupling agent KH-570 was added to 100g of 52% ethanol aqueous solution and stirred until homogeneous. The pH of the system was adjusted to 3-4 using 1.8mol / L hydrochloric acid. The mixture was stirred at 52℃ for 100min. Then, 14g of graphene oxide and 1.6g of sodium dodecyl sulfate were added and ultrasonically treated for 15min at a frequency of 85kHz. The temperature was then raised to 72℃ and stirred at 400r / min for 1.5h. The mixture was then filtered, washed, and vacuum dried.

[0039] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Methoxytrimethylsilane, KH-792 coupling agent, and amino-terminated polyamide amine were added to 70g of 45% ethanol aqueous solution. The mixture was stirred at 58℃ for 25min. The pH of the system was adjusted to 2-4 with 0.9mol / L hydrochloric acid. The mixture was stirred for 3h, cooled to room temperature, and distilled under reduced pressure to obtain the pre-prepared material. S2. Add hydroxyl-terminated polydimethylsiloxane, waterborne fluorinated hydroxyl acrylic emulsion, waterborne epoxy resin emulsion, activated graphene oxide, micro-nano silica, and dibutyltin dilaurate to the preform. Add water until the solid content is 37%. Stir at 42℃ for 100 min at a stirring speed of 150 r / min to obtain component A. S3. Mix aliphatic modified isocyanate curing agent, triethylenetetramine, and 25g of water, and stir at room temperature for 15min at a stirring speed of 300r / min to obtain component B.

[0040] Example 5

[0041] A self-healing silicone-based waterborne coating comprises the following raw materials: 20g of waterborne fluorinated hydroxyl acrylic emulsion, 30g of waterborne epoxy resin emulsion, 20g of hydroxyl-terminated polydimethylsiloxane, 6g of activated graphene oxide, 6g of micro / nano silica, 3g of dibutyltin dilaurate, 16g of methoxytrimethylsilane, 5g of KH-792 coupling agent, 2g of amino-terminated polyamide amine, 30g of aliphatic modified isocyanate curing agent, and 1.5g of triethylenetetramine.

[0042] Activated graphene oxide was prepared by the following steps: 4g of coupling agent KH-570 was added to 90g of 55% ethanol aqueous solution and stirred until homogeneous. The pH of the system was adjusted to 3-4 with 1.5mol / L hydrochloric acid. The mixture was stirred at 55℃ for 90min. 16g of graphene oxide and 1g of sodium dodecyl sulfate were added and ultrasonically treated for 20min at a frequency of 80kHz. The temperature was raised to 75℃ and stirred at 300r / min for 2h. The mixture was then filtered, washed, and vacuum dried.

[0043] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Methoxytrimethylsilane, KH-792 coupling agent, and amino-terminated polyamide amine were added to 60g of 50% ethanol aqueous solution. The mixture was stirred at 55℃ for 30min. The pH of the system was adjusted to 2-4 with 0.8mol / L hydrochloric acid. The mixture was stirred for 3.5h, cooled to room temperature, and distilled under reduced pressure to obtain the pre-prepared material. S2. Add hydroxyl-terminated polydimethylsiloxane, waterborne fluorinated hydroxyl acrylic emulsion, waterborne epoxy resin emulsion, activated graphene oxide, micro-nano silica, and dibutyltin dilaurate to the preform. Add water until the solid content is 35%. Stir at 45℃ for 90 min at a stirring speed of 200 r / min to obtain component A. S3. Mix aliphatic modified isocyanate curing agent, triethylenetetramine, and 25g of water, and stir at room temperature for 20min at a stirring speed of 240r / min to obtain component B.

[0044] Comparative Example 1

[0045] A self-healing silicone-based waterborne coating comprises the following raw materials: 20g of waterborne fluorinated hydroxyl acrylic emulsion, 30g of waterborne epoxy resin emulsion, 20g of hydroxyl-terminated polydimethylsiloxane, 6g of graphene oxide, 6g of micro / nano silica, 3g of dibutyltin dilaurate, 16g of methoxytrimethylsilane, 5g of KH-792 coupling agent, 2g of amino-terminated polyamide amine, 30g of aliphatic modified isocyanate curing agent, and 1.5g of triethylenetetramine.

[0046] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Methoxytrimethylsilane, KH-792 coupling agent, and amino-terminated polyamide amine were added to 60g of 50% ethanol aqueous solution. The mixture was stirred at 55℃ for 30min. The pH of the system was adjusted to 2-4 with 0.8mol / L hydrochloric acid. The mixture was stirred for 3.5h, cooled to room temperature, and distilled under reduced pressure to obtain the pre-prepared material. S2. Add hydroxyl-terminated polydimethylsiloxane, waterborne fluorinated hydroxyl acrylic emulsion, waterborne epoxy resin emulsion, graphene oxide, micro-nano silica, and dibutyltin dilaurate to the preform. Add water until the solid content is 35%. Stir at 45℃ for 90 min at a stirring speed of 200 r / min to obtain component A. S3. Mix aliphatic modified isocyanate curing agent, triethylenetetramine, and 25g of water, and stir at room temperature for 20min at a stirring speed of 240r / min to obtain component B.

[0047] Comparative Example 2

[0048] A self-healing silicone-based waterborne coating comprises the following raw materials: 40g of waterborne epoxy resin emulsion, 30g of hydroxyl-terminated polydimethylsiloxane, 6g of activated graphene oxide, 6g of micro / nano silica, 3g of dibutyltin dilaurate, 16g of methoxytrimethylsilane, 5g of KH-792 coupling agent, 2g of amino-terminated polyamide amine, 30g of aliphatic modified isocyanate curing agent, and 1.5g of triethylenetetramine.

[0049] Activated graphene oxide was prepared by the following steps: 4g of coupling agent KH-570 was added to 90g of 55% ethanol aqueous solution and stirred until homogeneous. The pH of the system was adjusted to 3-4 with 1.5mol / L hydrochloric acid. The mixture was stirred at 55℃ for 90min. 16g of graphene oxide and 1g of sodium dodecyl sulfate were added and ultrasonically treated for 20min at a frequency of 80kHz. The temperature was raised to 75℃ and stirred at 300r / min for 2h. The mixture was then filtered, washed, and vacuum dried.

[0050] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Methoxytrimethylsilane, KH-792 coupling agent, and amino-terminated polyamide amine were added to 60g of 50% ethanol aqueous solution. The mixture was stirred at 55℃ for 30min. The pH of the system was adjusted to 2-4 with 0.8mol / L hydrochloric acid. The mixture was stirred for 3.5h, cooled to room temperature, and distilled under reduced pressure to obtain the pre-prepared material. S2. Add water-based fluorinated hydroxyl acrylic emulsion, water-based epoxy resin emulsion, activated graphene oxide, micro-nano silica, and dibutyltin dilaurate to the preform. Add water until the solid content is 35%. Stir at 45℃ for 90 minutes at a stirring speed of 200 r / min to obtain component A. S3. Mix aliphatic modified isocyanate curing agent, triethylenetetramine, and 25g of water, and stir at room temperature for 20min at a stirring speed of 240r / min to obtain component B.

[0051] Comparative Example 3

[0052] A self-healing silicone-based waterborne coating comprises the following raw materials: 20g of waterborne fluorinated hydroxyl acrylic emulsion, 30g of waterborne epoxy resin emulsion, 20g of hydroxyl-terminated polydimethylsiloxane, 6g of activated graphene oxide, 6g of micro / nano silica, 3g of dibutyltin dilaurate, 17g of methoxytrimethylsilane, 6g of KH-792 coupling agent, 30g of aliphatic modified isocyanate curing agent, and 1.5g of triethylenetetramine.

[0053] Activated graphene oxide was prepared by the following steps: 4g of coupling agent KH-570 was added to 90g of 55% ethanol aqueous solution and stirred until homogeneous. The pH of the system was adjusted to 3-4 with 1.5mol / L hydrochloric acid. The mixture was stirred at 55℃ for 90min. 16g of graphene oxide and 1g of sodium dodecyl sulfate were added and ultrasonically treated for 20min at a frequency of 80kHz. The temperature was raised to 75℃ and stirred at 300r / min for 2h. The mixture was then filtered, washed, and vacuum dried.

[0054] The preparation method of the above-mentioned self-healing silicone-based waterborne coating includes the following steps: S1. Methoxytrimethylsilane and KH-792 coupling agent were added to 60g of 50% ethanol aqueous solution. The mixture was stirred at 55℃ for 30min. The pH of the system was adjusted to 2-4 with 0.8mol / L hydrochloric acid. The mixture was stirred for 3.5h, cooled to room temperature, and distilled under reduced pressure to obtain the pre-prepared material. S2. Add hydroxyl-terminated polydimethylsiloxane, waterborne fluorinated hydroxyl acrylic emulsion, waterborne epoxy resin emulsion, activated graphene oxide, micro-nano silica, and dibutyltin dilaurate to the preform. Add water until the solid content is 35%. Stir at 45℃ for 90 min at a stirring speed of 200 r / min to obtain component A. S3. Mix aliphatic modified isocyanate curing agent, triethylenetetramine, and 25g of water, and stir at room temperature for 20min at a stirring speed of 240r / min to obtain component B.

[0055] Mix component A and component B of each of Examples 5 and Comparative Examples 1-3 evenly, apply to a clean glass slide surface, cure at 90°C for 1-3 hours, and cool to room temperature to form a self-healing coating.

[0056] The static water contact angle of each group of self-healing coatings was measured using a contact angle tester. Then, following method B in GB / T23987-2009 "Artificial Weathering Exposure of Paint and Varnish Coatings to Fluorescent Ultraviolet Light and Water", the coatings were exposed for 1200 hours, and the static water contact angle of the exposed coatings was measured again using a contact angle tester.

[0057] like Figure 1 As shown, the static water contact angle of the self-healing coating formed by the coating obtained in Example 5 is always the highest, indicating a hydrophobic state, which is significantly better than that of Comparative Examples 1-2; while the difference with Comparative Example 3 is not significant.

[0058] Referring to ASTM D7027-05, "Test Method for Scratch Recovery of Plastics," a multi-finger scratch testing machine was used to scratch the above-mentioned coatings. The scratch tip was made of stainless steel with a diameter of 1 mm. The applied load was 15 N, the scratch speed was 100 mm / s, and the scratch length was 100 mm. The surface scratch width was observed using a laser confocal microscope. Afterward, the surface was left to stand in a 25°C, 80%RH environment for 24 hours, and the surface scratch width was observed again to calculate the self-healing rate. Subsequently, four more scratch-self-healing cycles were performed at the same location. After the fourth scratch-self-healing cycle, the self-healing rate was calculated.

[0059] Self-healing rate = width of surface scratch after standing at room temperature ÷ original width of surface scratch × 100%.

[0060] like Figure 2 As shown, the self-healing coating formed by the coating obtained in Example 5 consistently exhibits the highest self-healing rate, significantly superior to Comparative Example 1 and Comparative Example 3; while the difference with Comparative Example 2 is not significant.

[0061] 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 self-repairing silicone-based aqueous coating, characterized in that, The raw materials include, by mass fraction: 5-15 parts of water-based fluorine-containing hydroxyl acrylic acid emulsion, 10-20 parts of water-based epoxy resin emulsion, 5-15 parts of hydroxyl-terminated polydimethylsiloxane, 1-5 parts of activated graphene oxide, 1-5 parts of micro-nano silicon dioxide, 1-2 parts of catalyst, 5-10 parts of methoxytrimethylsilane, 1-4 parts of amino-silane coupling agent, 0.5-1.5 parts of amino-terminated polyamide amine, 10-20 parts of aliphatic modified isocyanate curing agent, and 0.5-1 part of triethylenetetramine.

2. The self-repairing, water-based, silicon-based paint according to claim 1, characterized in that, The catalyst is at least one of zinc octoate, organic tin catalyst, and organic bismuth catalyst.

3. The self-repairing, water-based, silicon-based paint according to claim 1, characterized in that, The amino-silane coupling agent is KH-792 coupling agent.

4. The self-repairing, water-based, silicon-based paint according to claim 1, characterized in that, The activated graphene oxide is prepared by the following steps: adding the silane coupling agent into an ethanol aqueous solution, stirring until uniform, adjusting the pH value of the system to 3-4, stirring at 50-60 DEG C for 1-2 h, adding graphene oxide and active agent into the system, ultrasonic treatment for 10-30 min, stirring at 70-80 DEG C for 1-3 h, filtering, washing, and vacuum drying.

5. The self-repairing, water-based, silicon-based paint according to claim 4, characterized in that, The silane coupling agent is coupling agent KH-570, and the active agent is sodium dodecyl sulfate.

6. The self-repairing, water-based, silicon-based paint according to claim 4, characterized in that, The mass ratio of the silane coupling agent, graphene oxide, and active agent is 1-3:5-10:0.1-1.

7. The self-repairing, water-based, silicon-based paint according to claim 4, characterized in that, The mass fraction of the ethanol aqueous solution is 50-60%.

8. The self-repairing, water-based, silicon-based paint according to claim 4, characterized in that, The ultrasonic frequency is 70-90 kHz.

9. A process for the preparation of a self-repairing silicone-based waterborne coating according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: S1, adding methoxytrimethylsilane, amino-silane coupling agent, and amino-terminated polyamide amine into an ethanol aqueous solution, stirring at 50-60 DEG C for 20-40 min, adjusting the pH value of the system to 2-4, continuing to stir for 2-5 h, cooling to room temperature, and obtaining a pre-prepared material by reduced pressure distillation; S2, adding hydroxyl-terminated polydimethylsiloxane, water-based fluorine-containing hydroxyl acrylic acid emulsion, water-based epoxy resin emulsion, activated graphene oxide, micro-nano silicon dioxide, and catalyst into the pre-prepared material, adjusting the solid content to 30-40%, stirring at 40-50 DEG C for 1-2 h, and obtaining component A; S3, adding aliphatic modified isocyanate curing agent and triethylenetetramine into a solvent, stirring at room temperature for 10-30 min, and obtaining component B.

10. The method for preparing the self-healing silicon-based waterborne coating according to claim 9, characterized in that, In S1, the pH value of the system is adjusted to 2-4 by using 0.5-1 mol / L hydrochloric acid.

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