Self-repairing self-cleaning coating and preparation method and use thereof

Abstract

The present application relates to a kind of self-repairing self-cleaning coating and its preparation method and purposes.The self-repairing self-cleaning coating is made of two components A, B, wherein, by weight parts, the A component is made of the following raw materials: the A component is made of the following raw materials: first end amino hyperbranched polysiloxane 50-90 parts;Modified graphene oxide 20-50 parts;Hydroxyl fluorocarbon resin 30-60 parts;Catalyst 0.1-3 parts;First solvent 80-200 parts;By weight parts, the B component is made of the following raw materials: isocyanate 50-200 parts;Second solvent 50-150 parts.The present application can realize fast self-healing after coating damage, and the coating has good self-repairing performance.

Description

TECHNICAL FIELD

[0001] The present application relates to a self-repairing and self-cleaning coating, and a preparation method and use thereof. BACKGROUND

[0002] Self-cleaning coatings refer to coatings that rely on their own hydrophobic physical properties to prevent contamination and facilitate cleaning, and have extremely wide application value in the fields of corrosion prevention, anti-icing, photovoltaics, etc. However, self-cleaning coatings are inevitably affected by external environments such as chemical corrosion and scratching and abrasion during actual use, which can easily cause the loss of low-surface-energy components or the destruction of micro-nano multi-level structures, thereby resulting in the loss of hydrophobic properties. To address this problem, a commonly used method is to construct self-cleaning coatings with self-repairing properties to repair the damage to the surface components or structure caused by friction and abrasion in a timely manner, thereby restoring the self-cleaning properties of the coating material.

[0003] There are mainly two ways to construct self-repairing self-cleaning coatings at present: one is to promote the migration of low-surface-energy substances in super-hydrophobic materials to regenerate super-hydrophobicity by moving low-surface-energy substances to the damaged area; the other is to re-establish the polymer network through reversible covalent and non-covalent interactions to repair the damaged super-hydrophobic surface structure, wherein hydrogen bonds are a weak intermolecular interaction that is easy to break and recombine compared with coordination bonds and covalent bonds, and require less self-repairing energy, which can achieve better self-repairing effect. For example, Chinese patent application “Microcapsule type self-repairing super-hydrophobic coating and preparation method thereof” (Publication No. CN109971331A) discloses a self-repairing super-hydrophobic coating composed of a polymer matrix, microcapsules coated with fluorosilane, etc. After the coating is damaged by abrasion, the fluorosilane stored inside the microcapsules migrates to the surface of the capsule under the driving force of surface free energy, providing low-surface-energy substances to repair the damaged super-hydrophobic surface; Chinese patent application “Water-based self-repairing super-hydrophobic coating and preparation method thereof” (Publication No. CN111892846A) uses low-surface-energy silicone oil and organic-inorganic hybrid emulsifiers to prepare microcapsule powder, which is then combined with multi-scale nanofiber particles to form a super-hydrophobic coating with self-repairing properties; this self-repairing method stores low-surface-energy substances in the self-repairing coating, resulting in a large number of pore structures in the coating, which leads to a decrease in the hardness and mechanical properties of the coating. Yanagisawa et al. introduced a multi-hydrogen bond array with high bonding strength and directional bonding properties into the polymer through thiourea, which improved the mechanical strength of the self-repairing polymer; Cui et al. combined hydrogen bonds and coordination bonds to prepare a self-repairing polymer with adjustable mechanical properties, which to some extent improved the poor mechanical properties of hydrogen bond type self-repairing polymers. The self-repairing polymers prepared by this self-repairing method are linear polymers with fewer hydrogen bond active sites, and have poor self-repairing properties. SUMMARY

[0004] To overcome the shortcomings of existing technologies, this invention provides a self-healing and self-cleaning coating, its preparation method, and its applications. This invention uses a hydrogen-bonded hyperbranched polymer as the self-healing polymer to prepare a self-cleaning coating with self-healing functions. This coating exhibits excellent hydrophobic properties, weather resistance, adhesion, and mechanical properties. The preparation method of this coating is simple to operate, operates under mild conditions, and is easily implemented for mass production and application.

[0005] The technical solution of the present invention is as follows:

[0006] On the one hand, the present invention provides a self-healing and self-cleaning coating, which is composed of two components, A and B, wherein...

[0007] Component A, by weight, is made from the following raw materials:

[0008] Component A is made from the following raw materials:

[0009] 50-90 parts of first-terminal amino hyperbranched polysiloxane;

[0010] 20-50 parts of modified graphene oxide;

[0011] 30-60 parts of hydroxyl fluorocarbon resin;

[0012] Catalyst 0.1-3 parts;

[0013] The first solvent is 80-200 parts;

[0014] Component B, by weight, is made from the following raw materials:

[0015] Isocyanate 50-200 parts;

[0016] 50-150 parts of the second solvent.

[0017] Preferably, component A is made from the following raw materials in parts by weight:

[0018] 60-80 parts of first-terminal amino hyperbranched polysiloxane;

[0019] 20-40 parts of modified graphene oxide;

[0020] 30-50 parts of hydroxyl fluorocarbon resin;

[0021] Catalyst 0.1-2 parts;

[0022] 80-150 parts of the first solvent;

[0023] Preferably, component B is made from the following raw materials in parts by weight:

[0024] 100-150 parts isocyanate;

[0025] 50-120 parts of the second solvent.

[0026] Preferably, the mass ratio of component A to component B is 1.5 to 2.5:1, and more preferably 2:1.

[0027] Preferably, the repeating unit of the first terminal amino hyperbranched polysiloxane is as follows:

[0028]

[0029] Wherein, n is selected from an integer between 6 and 10, preferably an integer between 6 and 8;

[0030] Preferably, the number average molecular weight of the first terminal amino hyperbranched polysiloxane is 50,000 to 150,000, and more preferably 75,000 to 120,000.

[0031] Preferably, the modified graphene oxide is prepared by the following method:

[0032] (1) Graphene oxide was ultrasonically dispersed in distilled water for 30 min to form a graphene oxide dispersion with a mass concentration of 1-4%.

[0033] (2) The second-terminal amino hyperbranched polysiloxane, the graphene oxide dispersion obtained in step (1), anhydrous ethanol, and distilled water are added to a three-necked flask, the pH is adjusted to 9, the reaction temperature is controlled at 70-90℃, the reaction is carried out for 8-12 hours, and finally the graphene oxide modified by second-terminal amino hyperbranched polysiloxane is obtained by filtration three times. Preferably, in step (1), the graphene oxide is a sheet, and the sheet diameter is 2-10 μm, preferably 5-10 μm.

[0034] Preferably, the graphene oxide has 1 to 6 layers, and more preferably 2 to 4 layers;

[0035] Preferably, the specific surface area of ​​the graphene oxide is 100–400 m². 2 / g, preferably 100-300m 2 / g;

[0036] Preferably, in step (2), the mass ratio between the second terminal amino hyperbranched polysiloxane and the graphene oxide dispersion obtained in step (1) is 5 to 10:1.

[0037] Preferably, in step (2), the mass ratio between anhydrous ethanol and distilled water is 3:1.

[0038] Preferably, in step (2), the mass ratio of the sum of the mass of the second terminal amino hyperbranched polysiloxane and the graphene oxide dispersion obtained in step (1) to the sum of the mass of anhydrous ethanol and distilled water is 1:3-5.

[0039] Preferably, in step (2), the repeating unit of the second terminal amino hyperbranched polysiloxane is as follows:

[0040]

[0041] Where n is selected from an integer from 1 to 5, preferably an integer from 3 to 5;

[0042] Preferably, the number average molecular weight of the second amino-terminated hyperbranched polysiloxane is 50,000 to 100,000, and more preferably 60,000 to 80,000.

[0043] Preferably, the hydroxyl value of the fluorocarbon resin is 20KOH / g to 70KOH / g, more preferably 30 to 60KOH / g, and even more preferably 40 to 60KOH / g;

[0044] Preferably, the catalyst is selected from one or more of dibutyltin dilaurate, dioctyltin dilaurate, di(dodecyl sulfide)dibutyltin, stannous octoate, dimethyltin dioctyldecanoate, and di-n-butyltin oxide, and is more preferably dibutyltin dilaurate or dimethyltin dioctyldecanoate.

[0045] Preferably, the first solvent and the second solvent are independently selected from one or more of butyl acetate, dimethyl nylonate, toluene, and xylene, with butyl acetate being the most preferred.

[0046] Preferably, the isocyanate is selected from one or more of toluene diisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, and HDI trimer, and is more preferably toluene diisocyanate;

[0047] On the other hand, the present invention provides a method for preparing the above-mentioned self-healing and self-cleaning coating, the method comprising stirring and mixing all the raw materials in component A to obtain component A; stirring and mixing all the raw materials in component B to obtain component B, thereby obtaining a two-component self-healing and self-cleaning coating.

[0048] Preferably, the stirring speed (which can be the stirring during the preparation of component A or the stirring during the preparation of component B) is 100 r / min to 800 r / min, and more preferably 300 r / min to 600 r / min.

[0049] Preferably, the temperature of the stirring and mixing (which can be the stirring and mixing during the preparation of component A or the stirring and mixing during the preparation of component B) is 20°C to 50°C, preferably room temperature.

[0050] Preferably, the stirring and mixing time (which can be the stirring and mixing during the preparation of component A or the stirring and mixing during the preparation of component B) is 20 to 60 minutes, preferably 30 to 50 minutes.

[0051] In another aspect, the present invention provides a self-healing and self-cleaning coating, which is made of the aforementioned self-healing and self-cleaning paint.

[0052] In another aspect, the present invention provides a method for preparing a self-healing and self-cleaning coating, the method comprising the step of mixing the A component and the B component and curing them on a substrate to form the coating; or the method comprising the step of curing the aforementioned self-healing and self-cleaning coating on a substrate to form the coating.

[0053] Preferably, the mass ratio of component A to component B is 1.5 to 2.5:1, more preferably 2:1;

[0054] Preferably, the curing temperature is 10–80°C, more preferably 20–70°C, and even more preferably 60°C.

[0055] Preferably, the curing time is 5 to 10 hours, more preferably 5 to 8 hours.

[0056] Preferably, the substrate is selected from concrete, wood, glass, and metal, with glass being the most preferred.

[0057] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0058] This invention selects specific first-terminal amino hyperbranched polysiloxanes and modified graphene oxide, which contain a large number of hydrogen bonds, providing self-healing active sites, enabling rapid self-healing after coating damage, and giving the coating good self-healing properties.

[0059] The present invention selects a specific first-terminal amino hyperbranched polysiloxane, which has a large number of hydrogen bond active sites, forming multiple hydrogen bond interactions with the glass substrate, enhancing the bonding ability with the substrate, and making the coating have high adhesion.

[0060] This invention reduces the surface energy of the coating by the synergistic effect of two low surface energy components: hydroxyl fluorocarbon resin and first-terminated amino hyperbranched polysiloxane. Modified graphene oxide constructs a micro-nano rough structure, thereby improving the hydrophobic properties of the coating.

[0061] The first-terminal amino hyperbranched polysiloxane of this invention has many reactive sites and high crosslinking density, and the modified graphene oxide has excellent mechanical properties and unique sheet structure, which endow the composite coating with excellent shielding performance, so that the coating has high mechanical properties and weather resistance.

[0062] This invention enables rapid self-healing after coating damage, and the coating has excellent self-repairing properties. Detailed Implementation

[0063] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0064] Unless otherwise specified, the raw materials used in the following examples are from the following sources:

[0065] The synthesis methods of the first-terminal amino hyperbranched polysiloxane and the second-terminal amino hyperbranched polysiloxane are referenced from Liu Jing et al., “Preparation and Performance Regulation of Nano-SiO2@Hyperbranched PDMS Composite Superhydrophobic Coatings”, Journal of Composite Materials, February 2023, Vol. 40, No. 2, pp. 872-883, with the following repeating units:

[0066]

[0067] Where n is an integer from 1 to 5.

[0068] Hydroxyl fluorocarbon resin, a type of FEVE fluorocarbon resin, was purchased from Shanghai Dongfu Chemical Technology Co., Ltd.

[0069] The isocyanates were all purchased from Yantai Wanhua Chemical Group Co., Ltd.

[0070] The graphene oxide was purchased from Nanjing Xianfeng Nanomaterials Technology Co., Ltd.

[0071] Other reagents or instruments can be purchased from the market.

[0072] Example 1

[0073] The modified graphene oxide in this embodiment was prepared by the following method:

[0074] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% (w / w) graphene oxide dispersion;

[0075] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0076] Self-healing and self-cleaning coatings are prepared using the following method:

[0077] 80g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95000, n=6), 20g of the aforementioned modified graphene oxide, 40g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 0.5g of dibutyltin dilaurate, and 130g of butyl acetate were mixed at room temperature and stirred at 400r / min for 30min to obtain component A of the self-cleaning coating.

[0078] 120g of toluene diisocyanate and 80g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0079] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 60°C for 7 hours.

[0080] Example 2

[0081] The modified graphene oxide in this embodiment was prepared by the following method:

[0082] (1) Graphene oxide (2 layers, 8 μm diameter, specific surface area of ​​150 m²) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% (w / w) graphene oxide dispersion.

[0083] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0084] Self-healing and self-cleaning coatings are prepared using the following method:

[0085] 90g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95000, n=6), 40g of the aforementioned modified graphene oxide, 60g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 1.5g of dibutyltin dilaurate, and 180g of butyl acetate were mixed at room temperature and stirred at 400r / min for 30min to obtain component A of the cleaning coating.

[0086] 180g of toluene diisocyanate and 120g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0087] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 60°C for 7 hours.

[0088] Example 3

[0089] The modified graphene oxide in this embodiment was prepared by the following method:

[0090] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% (w / w) graphene oxide dispersion.

[0091] (2) 50g of terminal amino hyperbranched polysiloxane (number average molecular weight 80000, n=5), 10g of graphene oxide dispersion prepared in step (1), 135g of anhydrous ethanol and 45g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0092] Self-healing and self-cleaning coatings are prepared using the following method:

[0093] 90g of amino-terminated hyperbranched polysiloxane (number average molecular weight 11000, n=10), 30g of the aforementioned modified graphene oxide, 50g of hydroxyl fluorocarbon resin (hydroxyl value 55KOH / g), 1.5g of dibutyltin dilaurate, and 150g of xylene were mixed at room temperature and stirred at 500r / min for 40min to obtain component A of the self-cleaning coating.

[0094] 120g of HDI trimer and 100g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0095] The self-cleaning coating is formed by mixing component A and component B at a mass ratio of 1.5:1 and curing at a curing temperature of 60°C for 7 hours.

[0096] Example 4

[0097] The modified graphene oxide in this embodiment was prepared by the following method:

[0098] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% graphene oxide dispersion;

[0099] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0100] Self-healing and self-cleaning coatings are prepared using the following method:

[0101] 80g of amino-terminated hyperbranched polysiloxane (number average molecular weight 80,000, n=6), 30g of the aforementioned modified graphene oxide, 40g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 1.5g of dimethyltin dioctyl decanoate, and 100g of xylene were mixed at room temperature and stirred at 400r / min for 40min to obtain component A of the self-cleaning coating.

[0102] 120g of HDI trimer and 100g of dimethyl nylonate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0103] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 50°C for 7 hours.

[0104] Comparative Example 1

[0105] The modified graphene oxide in this embodiment was prepared by the following method:

[0106] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% graphene oxide dispersion;

[0107] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0108] Self-healing and self-cleaning coatings are prepared using the following method:

[0109] 80g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95000, n=20), 20g of the aforementioned modified graphene oxide, 40g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 0.5g of dibutyltin dilaurate, and 130g of butyl acetate were mixed at room temperature and stirred at 400r / min for 30min to obtain component A of the self-cleaning coating.

[0110] 120g of toluene diisocyanate and 80g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0111] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 60°C for 7 hours.

[0112] Comparative Example 2

[0113] The modified graphene oxide in this embodiment was prepared by the following method:

[0114] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% graphene oxide dispersion;

[0115] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0116] Self-healing and self-cleaning coatings are prepared using the following method:

[0117] 80g of amino-terminated hyperbranched polysiloxane (number average molecular weight 30000, n=6), 20g of graphene oxide dispersion prepared in step (1), 40g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 0.5g of dibutyltin dilaurate, and 130g of butyl acetate were stirred and mixed at room temperature and 400r / min for 30min to obtain component A of the self-cleaning coating.

[0118] 120g of toluene diisocyanate and 80g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0119] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 60°C for 7 hours.

[0120] Comparative Example 3

[0121] The modified graphene oxide in this embodiment was prepared by the following method:

[0122] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% graphene oxide dispersion;

[0123] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0124] Self-healing and self-cleaning coatings are prepared using the following method:

[0125] 80g of amino-terminated hyperbranched polysiloxane (number average molecular weight 150,000, n=6), 20g of the aforementioned modified graphene oxide, 40g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 0.5g of dibutyltin dilaurate, and 130g of butyl acetate were mixed at room temperature and stirred at 400r / min for 30min to obtain component A of the self-cleaning coating.

[0126] 120g of toluene diisocyanate and 80g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0127] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 60°C for 7 hours.

[0128] Comparative Example 4

[0129] 80g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95000, n=6), 40g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 0.5g of dibutyltin dilaurate, and 130g of butyl acetate were mixed at room temperature and stirred at 400r / min for 30min to obtain component A of the self-cleaning coating.

[0130] 120g of toluene diisocyanate and 80g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0131] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 60°C for 7 hours.

[0132] Comparative Example 5

[0133] The modified graphene oxide in this embodiment was prepared by the following method:

[0134] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% graphene oxide dispersion;

[0135] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0136] Self-healing and self-cleaning coatings are prepared using the following method:

[0137] 30g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95000, n=9), 20g of graphene oxide dispersion prepared in step (1), 80g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 0.5g of dibutyltin dilaurate, and 100g of butyl acetate were stirred and mixed at room temperature and 400r / min for 30min to obtain component A of the self-cleaning coating.

[0138] 80g of toluene diisocyanate and 80g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0139] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 60°C for 7 hours.

[0140] Comparative Example 6

[0141] The modified graphene oxide in this embodiment was prepared by the following method:

[0142] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a 1% graphene oxide dispersion;

[0143] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0144] Self-healing and self-cleaning coatings are prepared using the following method:

[0145] 80g of amino-terminated polydimethylsiloxane, 20g of graphene oxide dispersion prepared in step (1), 40g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 0.5g of dibutyltin dilaurate, and 130g of butyl acetate were stirred and mixed at room temperature and 400r / min for 30min to obtain component A of the self-cleaning coating.

[0146] 120g of toluene diisocyanate and 80g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0147] Comparative Example 7

[0148] The modified graphene oxide in this embodiment was prepared by the following method:

[0149] (1) Graphene oxide (3 layers, 6 μm diameter, 200 m² specific surface area) 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a graphene oxide dispersion with a mass concentration of 5%;

[0150] (2) 70g of terminal amino hyperbranched polysiloxane (number average molecular weight 65000, n=4), 10g of graphene oxide dispersion prepared in step (1), 240g of anhydrous ethanol and 80g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80℃, the reaction was carried out for 10h, and finally the graphene oxide modified by terminal amino hyperbranched polysiloxane was obtained by filtration with ethanol three times.

[0151] Self-healing and self-cleaning coatings are prepared using the following method:

[0152] 80g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95000, n=6), 20g of the aforementioned modified graphene oxide, 40g of hydroxyl fluorocarbon resin (hydroxyl value 45KOH / g), 0.5g of dibutyltin dilaurate, and 130g of butyl acetate were mixed at room temperature and stirred at 400r / min for 30min to obtain component A of the self-cleaning coating.

[0153] 120g of toluene diisocyanate and 80g of butyl acetate were mixed at room temperature and stirred at 400r / min for 40min to obtain component B of the cleaning coating.

[0154] The self-cleaning coating is formed by mixing component A and component B in a mass ratio of 2:1 and curing at a curing temperature of 60°C for 7 hours.

[0155] After mixing components A and B of Examples 1-4 and Comparative Examples 1-7 in the above-mentioned mass ratio, the mixture was sprayed onto ordinary ultra-clear glass within 2 hours, cured at 60°C for 7 hours, and the performance of the paint film was tested after cooling to room temperature. The results are shown in Table 1.

[0156] Self-healing performance: 110g / cm load capacity 2 The coated sample was scratched 10 times with a fine copper brush, and then placed in an environment of 80°C for 1 hour. If more than 80% of the scratches on the sample were repaired, the self-healing performance of the sample was rated as excellent; if 50%-80% of the scratches on the sample were repaired, the self-healing performance of the sample was rated as medium; and if less than 50% of the scratches on the sample were repaired, the self-healing performance of the sample was rated as poor.

[0157] Table 1. Performance test results of coatings in Examples 1-4 and Comparative Examples 1-7

[0158]

[0159]

[0160]

[0161] Compared to Examples 1-4 of this invention, Comparative Example 1 uses a terminal amino hyperbranched polymer with a longer Si-O chain segment, which significantly reduces its compatibility and reactivity in the system, making it difficult to effectively cure with other components. This results in decreased water contact angle, light transmittance, gloss, and a significant reduction in impact resistance. Comparative Example 2 uses a low molecular weight terminal amino hyperbranched polymer with fewer active groups and self-healing active sites, leading to poor self-healing after coating damage. Comparative Example 3 uses a high molecular weight terminal amino hyperbranched polymer with a high hydrogen bond content and numerous self-healing active sites, but its migration ability is significantly reduced, failing to migrate extensively to the paint film surface. This results in increased surface energy, decreased protection of the paint film, reduced impact resistance and stain resistance, and poor weather resistance. Comparative Example 4 does not use modified graphene oxide, resulting in reduced surface roughness, increased surface energy, poor hydrophobicity, and a lack of [other benefits]. The use of graphene oxide in Comparative Example 5 resulted in decreased thermal conductivity and barrier properties, as well as reduced weather resistance and stain resistance. In Comparative Example 5, the amounts of terminal amino hyperbranched polymer and hydroxyl fluorocarbon resin were outside the effective weight range, leading to low hydrogen bond content, few self-healing active sites, poor self-healing performance, poor multi-hydrogen bonding with the glass substrate, and low adhesion. Comparative Example 6 used amino-terminated polydimethylsiloxane instead of the terminal amino hyperbranched polymer, resulting in low hydrogen bond content, few active groups, poor synergistic effect between organosilicon and organofluorine, and low crosslinking density, leading to poor self-healing performance, low adhesion, and a significant decrease in water contact angle, light transmittance, gloss, and weather resistance. Comparative Example 7 used a high-concentration graphene oxide dispersion; when modified with terminal amino hyperbranched polysiloxane, the graphene oxide did not react completely, and the remaining graphene oxide easily agglomerated in the coating components, causing a decline in the overall performance of the coating.

[0162] In summary, the coatings obtained by using terminal amino hyperbranched polysiloxane, modified graphene oxide, hydroxyl fluorocarbon resin, catalyst, solvent, etc. as the main film-forming units in Examples 1 to 4 of the present invention, combined with the curing agent isocyanate, have high adhesion, high impact resistance, high water contact angle, high weather resistance, and high self-healing properties.

Claims

1. A self-healing and self-cleaning coating, comprising two components, A and B, wherein, Component A, by weight, is made from the following raw materials: Component A is made from the following raw materials: 50-90 parts of first-terminal amino hyperbranched polysiloxane; 20-50 parts of modified graphene oxide; 30-60 parts of hydroxyl fluorocarbon resin; Catalyst 0.1-3 parts; The first solvent is 80-200 parts; Component B, by weight, is made from the following raw materials: 50-200 parts of isocyanate; 50-150 parts of the second solvent; The repeating unit of the first terminal amino hyperbranched polysiloxane is as follows: Where n is an integer selected from 6 to 10; The modified graphene oxide is prepared by the following method: (1) Graphene oxide was ultrasonically dispersed in distilled water for 30 min to form a graphene oxide dispersion with a mass concentration of 1-4%. (2) Add the second-terminal amino hyperbranched polysiloxane, the graphene oxide dispersion obtained in step (1), anhydrous ethanol, and distilled water into a three-necked flask, adjust the pH to 9, control the reaction temperature at 70-90℃, react for 8-12 hours, and finally wash three times with ethanol by filtration to obtain graphene oxide modified with the second-terminal amino hyperbranched polysiloxane. In step (2), the repeating unit of the second terminal amino hyperbranched polysiloxane is as follows: Where n is an integer selected from 1 to 5; The number-average molecular weight of the second-terminated amino hyperbranched polysiloxane is 50,000 to 100,000.

2. The coating according to claim 1, wherein, Component A, by weight, is made from the following raw materials: 60-80 parts of first-terminal amino hyperbranched polysiloxane; 20-40 parts of modified graphene oxide; 30-50 parts of hydroxyl fluorocarbon resin; Catalyst 0.1-2 parts; The first solvent is 80-150 parts.

3. The coating according to claim 1, wherein, Component B, by weight, is made from the following raw materials: 100-150 parts isocyanate; 50-120 parts of the second solvent.

4. The coating according to claim 1, wherein, The mass ratio of component A to component B is 1.5 to 2.5:

1.

5. The coating according to claim 4, wherein, The mass ratio of component A to component B is 2:

1.

6. The coating according to claim 1, wherein, In the repeating unit of the first terminal amino hyperbranched polysiloxane, n is an integer from 6 to 8.

7. The coating according to claim 1, wherein, The number-average molecular weight of the first-terminal amino hyperbranched polysiloxane is 50,000 to 150,000.

8. The coating according to claim 7, wherein, The number-average molecular weight of the first-terminal amino hyperbranched polysiloxane is 75,000 to 120,000.

9. The coating according to any one of claims 1 to 8, wherein, In step (1) of the method for preparing modified graphene oxide, the graphene oxide is a sheet with a diameter of 2 to 10 μm.

10. The coating according to claim 9, wherein, The diameter of the sheet is 5–10 μm.

11. The coating according to any one of claims 1 to 8, wherein, In step (1) of the method for preparing modified graphene oxide, the number of layers of the graphene oxide is 1 to 6.

12. The coating according to claim 11, wherein, The graphene oxide has 2 to 4 layers.

13. The coating according to any one of claims 1 to 8, wherein, In step (1) of the method for preparing modified graphene oxide, the specific surface area of ​​the graphene oxide is 100–400 m². 2 / g.

14. The coating according to claim 13, wherein, The specific surface area of ​​the graphene oxide is 100–300 m². 2 / g.

15. The coating according to any one of claims 1 to 8, wherein, In step (2) of the method for preparing modified graphene oxide, the mass ratio between the second terminal amino hyperbranched polysiloxane and the graphene oxide dispersion obtained in step (1) is 5 to 10:

1.

16. The coating according to any one of claims 1 to 8, wherein, In step (2) of the method for preparing modified graphene oxide, the mass ratio between anhydrous ethanol and distilled water is 3:

1.

17. The coating according to any one of claims 1 to 8, wherein, In step (2) of the method for preparing modified graphene oxide, the mass ratio of the sum of the mass of the second terminal amino hyperbranched polysiloxane and the graphene oxide dispersion obtained in step (1) to the sum of the mass of anhydrous ethanol and distilled water is 1:3-5.

18. The coating according to any one of claims 1 to 8, wherein, In step (2) of the method for preparing modified graphene oxide, n in the repeating unit of the second terminal amino hyperbranched polysiloxane is selected from an integer of 3-5.

19. The coating according to any one of claims 1 to 8, wherein, In step (2) of the method for preparing modified graphene oxide, the number average molecular weight of the second terminal amino hyperbranched polysiloxane is 60,000 to 80,000.

20. The coating according to any one of claims 1 to 8, wherein, The catalyst is selected from one or more of dibutyltin dilaurate, dioctyltin dilaurate, di(dodecyl sulfide)dibutyltin, stannous octoate, dimethyltin dioctyldecanoate, and di-n-butyltin oxide.

21. The coating according to claim 20, wherein, The catalyst is selected from dibutyltin dilaurate and dimethyltin dioctyldecanoate.

22. The coating according to any one of claims 1 to 8, wherein, The first solvent and the second solvent are independently selected from one or more of butyl acetate, dimethyl nylonate, toluene, and xylene.

23. The coating according to claim 22, wherein, The first solvent and the second solvent are butyl acetate.

24. The coating according to any one of claims 1 to 8, wherein, The isocyanate is selected from one or more of toluene diisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, and HDI trimer.

25. The coating according to claim 24, wherein, The isocyanate is toluene diisocyanate.

26. A method for preparing a self-healing and self-cleaning coating according to any one of claims 1 to 25, the method comprising stirring and mixing all raw materials in component A to obtain component A; stirring and mixing all raw materials in component B to obtain component B, thereby obtaining a two-component self-healing and self-cleaning coating; in, The stirring speed is 100 r / min to 800 r / min; the stirring temperature is 20℃ to 50℃; and the stirring time is 20 to 60 min.

27. The preparation method according to claim 26, wherein, The stirring speed is 300 r / min to 600 r / min; the stirring temperature is room temperature; and the stirring time is 30 to 50 min.

28. A self-healing and self-cleaning coating, the coating being made from the self-healing and self-cleaning paint according to any one of claims 1 to 25.

29. A method for preparing the self-healing and self-cleaning coating of claim 28, the method comprising the step of mixing the A component and the B component and curing them on a substrate to form the coating; wherein, The curing temperature is 10–80°C; the curing time is 5–10 hours; and the substrate is selected from concrete, wood, glass, or metal.

30. The preparation method according to claim 29, wherein, The mass ratio of component A to component B is 2:

1.

31. The preparation method according to claim 29, wherein, The curing temperature is 20–70°C.

32. The preparation method according to claim 29, wherein, The curing temperature is 60°C.

33. The preparation method according to claim 29, wherein, The curing time is 5 to 8 hours.

34. The preparation method according to claim 29, wherein, The substrate is glass.

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