Self-repairing and self-cleaning coating as well as preparation method and application thereof

Abstract

The invention relates to a self-repairing and self-cleaning coating as well as a preparation method and application thereof. The self-repairing and self-cleaning coating is composed of a component A and a component B. The component A is prepared from the following raw materials in parts by weight: 50-90 parts of first amino-terminated hyperbranched polysiloxane, 10-20 parts of a second amino-terminated hyperbranched polysiloxane, 10-20 parts of a curing agent, 10-20 parts of a curing agent and 10-20 parts of a curing agent. 20 to 50 parts of modified graphene oxide; 30 to 60 parts of hydroxyl fluorocarbon resin; 0.1-3 parts of a catalyst; 80 to 200 parts of a first solvent; the component B is prepared from the following raw materials in parts by weight: 50 to 200 parts of isocyanate; and 50-150 parts of a second solvent. After the coating is damaged, rapid self-healing can be achieved, and the coating has good self-repairing performance.

Description

Technical Field

[0001] The invention relates to a self-repairing and self-cleaning coating and a preparation method and application thereof. Background Art

[0002] Self-cleaning coatings rely on the hydrophobic physical properties of the coating itself to prevent fouling and make it easy to clean. They have extremely wide application value in the fields of anti-corrosion, anti-icing, photovoltaics, etc. However, in actual use, self-cleaning coatings are inevitably affected by external environments such as chemical corrosion, scratches and wear, which can easily cause the loss of low surface energy components or the destruction of micro-nano multi-level structures, resulting in the loss of hydrophobic properties. To address this problem, the commonly used method is to construct a self-cleaning coating with self-repairing properties to promptly repair the damage caused by friction and wear to the surface components or structures, thereby restoring the self-cleaning properties of the coating material.

[0003] Currently, there are two main ways to construct self-healing and self-cleaning coatings: one is to promote the migration of low surface energy substances in superhydrophobic materials, so that the low surface energy substances move to the damaged area to regenerate superhydrophobicity; the other is to re-establish the polymer network through reversible covalent and non-covalent bond interactions to repair the damaged superhydrophobic surface structure. Among them, hydrogen bonds are a weak intermolecular interaction. Compared with coordination bonds and covalent bonds, they are easy to break and reorganize. The required self-repair energy is smaller, and a better self-repair effect can be obtained. For example, the Chinese invention patent application "A microcapsule-type self-repairing super-hydrophobic coating and its preparation method" (publication number: CN109971331A) discloses a self-repairing super-hydrophobic coating composed of a polymer matrix, microcapsules coated with fluorosilane, etc. After the coating is damaged by wear, the fluorosilane stored inside the microcapsules migrates to the capsule surface driven by the surface free energy, providing low surface energy substances to repair the damaged super-hydrophobic surface; the Chinese invention patent application "A water-based self-repairing super-hydrophobic coating and its preparation method" (publication number: CN111892846A) uses low surface energy silicone oil and organic-inorganic hybrid emulsifier to prepare microcapsule powder, and then makes a super-hydrophobic coating with self-repairing properties with multi-scale nanofiber particles; this self-repairing method stores low surface energy substances in the self-repairing coating, so that there are a large number of pore structures in the coating, resulting in a decrease in the hardness and mechanical properties of the coating. Yanagisawa et al. introduced multiple hydrogen bond arrays with high bonding strength and directional bonding properties into polymers through thiourea, thereby improving the mechanical strength of self-healing polymers; Cui et al. prepared self-healing polymers with adjustable mechanical properties by combining hydrogen bonds and coordination bonds, which to some extent improved the problem of poor mechanical properties of hydrogen-bonded self-healing polymers. The self-healing polymers prepared by this self-healing method are all linear polymers, which contain fewer hydrogen bond active sites and have poor self-healing properties. Summary of the invention

[0004] In order to overcome the defects of the prior art, the present invention provides a self-repairing self-cleaning coating and a preparation method and use thereof. The present invention uses a hydrogen-bonded hyperbranched polymer as a self-repairing polymer to prepare a self-cleaning coating with a self-repairing function. The coating has excellent hydrophobicity, weather resistance, adhesion and mechanical properties. The preparation method of the coating of the present invention is simple to operate, mild in conditions, and easy to achieve 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-repairing and self-cleaning coating, which consists of two components A and B, wherein:

[0007] The A component is made of the following raw materials by weight:

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

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

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

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

[0012] Catalyst 0.1-3 parts;

[0013] 80-200 parts of the first solvent;

[0014] The B component is made of the following raw materials by weight:

[0015] Isocyanate 50-200 parts;

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

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

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

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

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

[0021] Catalyst 0.1-2 parts;

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

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

[0024] Isocyanate 100-150 parts;

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

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

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

[0028]

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

[0030] Preferably, the number average molecular weight of the first amino-terminated hyperbranched polysiloxane is 50,000 to 150,000, preferably 75,000 to 120,000;

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

[0032] (1) ultrasonically dispersing graphene oxide in distilled water for 30 minutes to form a graphene oxide dispersion with a mass concentration of 1-4%;

[0033] (2) adding the second amino-terminated hyperbranched polysiloxane and the graphene oxide dispersion obtained in step (1), anhydrous ethanol and distilled water into a three-necked flask, adjusting the pH to 9, controlling the reaction temperature at 70-90° C., reacting for 8-12 hours, and finally filtering and washing three times with ethanol to obtain the second amino-terminated hyperbranched polysiloxane-modified graphene oxide; preferably, in step (1), the graphene oxide is a sheet, and the diameter of the sheet is 2-10 μm, preferably 5-10 μm;

[0034] Preferably, the number of layers of the graphene oxide is 1 to 6 layers, preferably 2 to 4 layers;

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

[0036] Preferably, in step (2), the mass ratio between the second amino-terminated 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 amino-terminated 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 amino-terminated hyperbranched polysiloxane is as follows:

[0040]

[0041] Wherein, n is selected from an integer of 1-5, preferably an integer of 3-5;

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

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

[0044] Preferably, the catalyst is selected from one or more of dibutyltin dilaurate, di-n-octyltin dilaurate, dibutyltin didodecylsulfide, stannous octoate, dimethyltin dioctanoate, and di-n-butyltin oxide, preferably dibutyltin dilaurate and dimethyltin dioctanoate;

[0045] Preferably, the first solvent and the second solvent are independently selected from one or more of butyl acetate, dimethyl nylonate, toluene, and xylene, preferably butyl acetate;

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

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

[0048] Preferably, the rotation speed of the stirring and mixing (the stirring and mixing can be the stirring and mixing when preparing component A or the stirring and mixing when preparing component B) is 100 r / min to 800 r / min, preferably 300 r / min to 600 r / min.

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

[0050] Preferably, the stirring and mixing (the stirring and mixing may be the stirring and mixing during the preparation of component A or the stirring and mixing during the preparation of component B) takes place for 20 to 60 minutes, preferably for 30 to 50 minutes.

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

[0052] On the other hand, the present invention provides a method for preparing a self-repairing and self-cleaning coating, which method includes the steps of mixing the component A and the component B and curing them on a substrate to form the coating; or the method includes the step of curing the aforementioned self-repairing 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, preferably 2:1;

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

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

[0056] Preferably, the substrate is selected from concrete, wood, glass, metal, preferably glass.

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

[0058] The present invention selects specific first-terminal amino hyperbranched polysiloxane and modified graphene oxide, which contain a large number of hydrogen bonds, provide self-repairing active sites, can achieve rapid self-healing of the coating after damage, and make the coating have good self-repairing performance;

[0059] The present invention selects a specific first terminal amino hyperbranched polysiloxane, which has a large number of hydrogen bond active sites, forms multiple hydrogen bonds with the glass substrate, strengthens the bonding ability with the substrate, and makes the coating have higher adhesion;

[0060] The present invention reduces the surface energy of the coating through the synergistic effect of two low surface energy components, namely, the hydroxyl fluorocarbon resin and the first terminal amino hyperbranched polysiloxane, and constructs a micro-nano rough structure through modified graphene oxide, thereby improving the hydrophobicity of the coating.

[0061] The first terminal amino hyperbranched polysiloxane of the present invention has many reactive sites and high crosslinking density, and the modified graphene oxide has excellent mechanical properties and a unique lamellar structure, which endows the composite coating with excellent shielding properties, so that the coating has higher mechanical properties and weather resistance.

[0062] The present invention can achieve rapid self-healing after the coating is damaged, and the coating has good self-repairing performance. DETAILED DESCRIPTION

[0063] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies realized based on the above content of the present invention are included in the scope that the present invention is intended to protect.

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

[0065] The synthesis methods of the first amino-terminated hyperbranched polysiloxane and the second amino-terminated hyperbranched polysiloxane refer to Liu Jing et al., "Preparation and Performance Control of Nano-SiO2@Hyperbranched PDMS Composite Super-Hydrophobic Coating", Journal of Composite Materials, Vol. 40, No. 2, February 2023, pp. 872-883, and the repeating units are as follows:

[0066]

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

[0068] Hydroxy fluorocarbon resin, a FEVE-type fluorocarbon resin, was purchased from Shanghai Dongfu Chemical Technology Co., Ltd.;

[0069] Isocyanates were purchased from Yantai Wanhua Chemical Group Co., Ltd.;

[0070] Graphene oxide was purchased from Nanjing Xianfeng Nanomaterial Technology Co., Ltd.;

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

[0072] Example 1

[0073] The modified graphene oxide of this embodiment is prepared by the following method:

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

[0075] (2) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0076] The self-repairing and self-cleaning coating is prepared by the following method:

[0077] 80 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95,000, n=6), 20 g of the modified graphene oxide prepared above, 40 g of hydroxyl fluorocarbon resin (hydroxyl value 45 KOH / g), 0.5 g of dibutyltin dilaurate, and 130 g of butyl acetate were stirred and mixed at room temperature at a speed of 400 r / min for 30 min to obtain component A of the self-cleaning coating.

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

[0079] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0080] Example 2

[0081] The modified graphene oxide of this embodiment is prepared by the following method:

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

[0083] (2) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0084] The self-repairing and self-cleaning coating is prepared by the following method:

[0085] 90 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95,000, n=6), 40 g of the modified graphene oxide prepared above, 60 g of hydroxyl fluorocarbon resin (hydroxyl value 45 KOH / g), 1.5 g of dibutyltin dilaurate, and 180 g of butyl acetate were stirred and mixed at room temperature at a speed of 400 r / min for 30 min to obtain component A of the self-cleaning coating.

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

[0087] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0088] Example 3

[0089] The modified graphene oxide of this embodiment is prepared by the following method:

[0090] (1) Graphene oxide (3 layers, 6 μm in diameter, and a specific surface area of ​​200 m 2 / g) was ultrasonically dispersed in distilled water for 30 min to form a graphene oxide dispersion with a mass concentration of 1%;

[0091] (2) 50 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 80,000, n=5), 10 g of the graphene oxide dispersion prepared in step (1), 135 g of anhydrous ethanol, and 45 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the mixture was filtered and washed three times with ethanol to obtain graphene oxide modified with amino-terminated hyperbranched polysiloxane;

[0092] The self-repairing and self-cleaning coating is prepared by the following method:

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

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

[0095] The components A and B of the self-cleaning coating were mixed in a mass ratio of 1.5:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0096] Example 4

[0097] The modified graphene oxide of this embodiment is prepared by the following method:

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

[0099] (2) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0100] The self-repairing and self-cleaning coating is prepared by the following method:

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

[0102] 120 g of HDI trimer and 100 g of nylon acid dimethyl ester were stirred and mixed at room temperature at a speed of 400 r / min for 40 minutes to obtain component B of the self-cleaning coating.

[0103] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured for 7 hours at a curing temperature of 50°C to form a self-cleaning coating.

[0104] Comparative Example 1

[0105] The modified graphene oxide of this embodiment is prepared by the following method:

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

[0107] (2) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0108] The self-repairing and self-cleaning coating is prepared by the following method:

[0109] 80g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95000, n=20), 20g of the modified graphene oxide prepared above, 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 at a speed of 400r / min for 30min to obtain component A of the self-cleaning coating.

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

[0111] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0112] Comparative Example 2

[0113] The modified graphene oxide of this embodiment is prepared by the following method:

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

[0115] (2) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0116] The self-repairing and self-cleaning coating is prepared by the following method:

[0117] 80 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 30,000, n=6), 20 g of graphene oxide dispersion prepared in step (1), 40 g of hydroxyl fluorocarbon resin (hydroxyl value 45 KOH / g), 0.5 g of dibutyltin dilaurate, and 130 g of butyl acetate were stirred and mixed at room temperature at a speed of 400 r / min for 30 min to obtain component A of the self-cleaning coating.

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

[0119] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0120] Comparative Example 3

[0121] The modified graphene oxide of this embodiment is prepared by the following method:

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

[0123] (2) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0124] The self-repairing and self-cleaning coating is prepared by the following method:

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

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

[0127] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0128] Comparative Example 4

[0129] 80 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95,000, n=6), 40 g of hydroxyl fluorocarbon resin (hydroxyl value 45 KOH / g), 0.5 g of dibutyltin dilaurate, and 130 g of butyl acetate were stirred and mixed at room temperature at a speed of 400 r / min for 30 min to obtain component A of the self-cleaning coating.

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

[0131] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0132] Comparative Example 5

[0133] The modified graphene oxide of this embodiment is prepared by the following method:

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

[0135] (2) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0136] The self-repairing and self-cleaning coating is prepared by the following method:

[0137] 30 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95,000, n=9), 20 g of graphene oxide dispersion prepared in step (1), 80 g of hydroxyl fluorocarbon resin (hydroxyl value 45 KOH / g), 0.5 g of dibutyltin dilaurate, and 100 g of butyl acetate were stirred and mixed at room temperature at a speed of 400 r / min for 30 min to obtain component A of the self-cleaning coating.

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

[0139] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0140] Comparative Example 6

[0141] The modified graphene oxide of this embodiment is prepared by the following method:

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

[0143] (2) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0144] The self-repairing and self-cleaning coating is prepared by the following method:

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

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

[0147] Comparative Example 7

[0148] The modified graphene oxide of this embodiment is prepared by the following method:

[0149] (1) Graphene oxide (3 layers, 6 μm in diameter, and a specific surface area of ​​200 m 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) 70 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 65,000, n=4), 10 g of the graphene oxide dispersion prepared in step (1), 240 g of anhydrous ethanol, and 80 g of distilled water were added to a three-necked flask, the pH was adjusted to 9, the reaction temperature was controlled at 80° C., the reaction was carried out for 10 h, and finally, the graphene oxide modified with amino-terminated hyperbranched polysiloxane was obtained by suction filtration and washing three times with ethanol;

[0151] The self-repairing and self-cleaning coating is prepared by the following method:

[0152] 80 g of amino-terminated hyperbranched polysiloxane (number average molecular weight 95,000, n=6), 20 g of the modified graphene oxide prepared above, 40 g of hydroxyl fluorocarbon resin (hydroxyl value 45 KOH / g), 0.5 g of dibutyltin dilaurate, and 130 g of butyl acetate were stirred and mixed at room temperature at a speed of 400 r / min for 30 min to obtain component A of the self-cleaning coating.

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

[0154] The component A and the component B of the self-cleaning coating are mixed in a mass ratio of 2:1 and cured at a curing temperature of 60° C. for 7 hours to form a self-cleaning coating.

[0155] The components A and B of the above-mentioned embodiments 1 to 4 and comparative examples 1 to 7 were mixed in a mass ratio, sprayed onto ordinary ultra-white 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-repairing performance: load 110g / cm 2 The coated sample was scratched 10 times with a fine copper brush, and then the sample was placed in an environment of 80°C for 1 hour. If more than 80% of the scratches on the sample were repaired, the self-repairing performance of the sample was evaluated as excellent, if 50%-80% of the scratches on the sample were repaired, the self-repairing performance of the sample was evaluated as medium, and if less than 50% of the scratches on the sample were repaired, the self-repairing performance of the sample was evaluated as poor.

[0157] Table 1 Coating performance test results of Examples 1 to 4 and Comparative Examples 1 to 7

[0158]

[0159]

[0160]

[0161] Compared with Examples 1-4 of the present invention, Comparative Example 1 uses an amino-terminated hyperbranched polymer with a longer Si-O segment, and its compatibility, reactivity, etc. in the system are greatly reduced, and it is difficult to effectively carry out a curing reaction with other components, and the water contact angle, light transmittance, and glossiness are reduced, and the impact resistance is greatly reduced; Comparative Example 2 uses a small molecular weight amino-terminated hyperbranched polymer, which has few active groups and few self-repairing active sites. After the coating is damaged, the self-repairing effect is poor; Comparative Example 3 uses a high molecular weight amino-terminated hyperbranched polymer, which has a high hydrogen bond content and many self-repairing active sites, but its migration ability is greatly reduced, and it fails to migrate to the paint film surface to a large extent, resulting in an increase in its surface energy, a decrease in the protection ability of the paint film, a decrease in impact resistance and stain resistance, and poor weather resistance; Comparative Example 4 does not use modified graphene oxide, the roughness of the coating surface is reduced, the surface energy is increased, the hydrophobicity is poor, and there is a lack of Graphene oxide, the thermal conductivity and barrier properties of the coating are reduced, and the weather resistance and stain resistance are reduced; the amount of the amino-terminated hyperbranched polymer and the hydroxyl fluorocarbon resin used in Comparative Example 5 is not within the effective weight fraction range, the hydrogen bond content is small, the self-healing active sites are small, the self-healing performance is poor, the multiple hydrogen bonding with the glass substrate is poor, and the adhesion is low; Comparative Example 6 uses amino-terminated polydimethylsiloxane instead of amino-terminated hyperbranched polymer, which has low hydrogen bond content, few active groups, poor synergy between silicone and organic fluorine, and low crosslinking density, resulting in poor self-healing performance of the coating, low adhesion, and a significant decrease in water contact angle, light transmittance, gloss, weather resistance, etc.; Comparative Example 7 uses a graphene oxide dispersion with a high mass concentration. When the amino-terminated hyperbranched polysiloxane is used to modify it, the graphene oxide is not completely reacted, and the remaining graphene oxide is prone to agglomeration in the coating component, resulting in a decrease in the comprehensive performance of the coating.

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

Claims

1. A self-repairing and self-cleaning coating, the coating is composed of two components A and B, wherein: The A component is made of the following raw materials by weight: Component A is made from the following raw materials: 50-90 parts of the first amino-terminated hyperbranched polysiloxane; 20-50 parts of modified graphene oxide; 30-60 parts of hydroxy fluorocarbon resin; Catalyst 0.1-3 parts; 80-200 parts of the first solvent; The B component is made of the following raw materials by weight: Isocyanate 50-200 parts; 50-150 parts of the second solvent.

2. The coating according to claim 1, wherein The A component is made of the following raw materials by weight: 60-80 parts of the first amino-terminated hyperbranched polysiloxane; 20-40 parts of modified graphene oxide; 30-50 parts of hydroxy fluorocarbon resin; Catalyst 0.1-2 parts; 80-150 parts of the first solvent; Preferably, the B component is made of the following raw materials in parts by weight: Isocyanate 100-150 parts; 50-120 parts of the second solvent; Preferably, the mass ratio of component A to component B is 1.5-2.5:1, preferably 2:

1.

3. The coating according to claim 1 or 2, wherein The repeating unit of the first amino-terminated hyperbranched polysiloxane is as follows: Wherein, n is selected from an integer of 6-10, preferably an integer of 6-8; Preferably, the number average molecular weight of the first amino-terminated hyperbranched polysiloxane is 50,000 to 150,000, preferably 75,000 to 120,000.

4. The coating according to any one of claims 1 to 3, wherein The modified graphene oxide is prepared by the following method: (1) ultrasonically dispersing graphene oxide in distilled water for 30 minutes to form a graphene oxide dispersion with a mass concentration of 1-4%; (2) adding the second amino-terminated hyperbranched polysiloxane and the graphene oxide dispersion obtained in step (1), anhydrous ethanol and distilled water into a three-necked flask, adjusting the pH to 9, controlling the reaction temperature at 70-90° C., reacting for 8-12 hours, and finally filtering and washing three times with ethanol to obtain the second amino-terminated hyperbranched polysiloxane-modified graphene oxide; preferably, in step (1), the graphene oxide is a sheet, and the diameter of the sheet is 2-10 μm, preferably 5-10 μm; Preferably, the number of layers of the graphene oxide is 1 to 6 layers, preferably 2 to 4 layers; Preferably, the specific surface area of ​​the graphene oxide is 100 to 400 m 2 / g, preferably 100 to 300 m 2 / g; Preferably, in step (2), the mass ratio between the second amino-terminated hyperbranched polysiloxane and the graphene oxide dispersion obtained in step (1) is 5 to 10:1; Preferably, in step (2), the mass ratio between anhydrous ethanol and distilled water is 3:1; Preferably, in step (2), the mass ratio of the sum of the mass of the second amino-terminated 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; Preferably, in step (2), the repeating unit of the second amino-terminated hyperbranched polysiloxane is as follows: Wherein, n is selected from an integer of 1-5, preferably an integer of 3-5; Preferably, the number average molecular weight of the second amino-terminated hyperbranched polysiloxane is 50,000 to 100,000, preferably 60,000 to 80,000.

5. The coating according to any one of claims 1 to 4, wherein The hydroxy value of the hydroxy fluorocarbon resin is 20 to 70 KOH / g, preferably 30 to 60 KOH / g, and more preferably 40 to 60 KOH / g.

6. The coating according to any one of claims 1 to 5, wherein The catalyst is selected from one or more of dibutyltin dilaurate, di-n-octyltin dilaurate, dibutyltin didodecylsulfide, stannous octoate, dimethyltin dioctanoate, and di-n-butyltin oxide, preferably dibutyltin dilaurate and dimethyltin dioctanoate.

7. The coating according to any one of claims 1 to 6, wherein The first solvent and the second solvent are independently selected from one or more of butyl acetate, dimethyl nylonate, toluene, and xylene, preferably butyl acetate; Preferably, the isocyanate is selected from one or more of toluene diisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, HDI trimer, preferably toluene diisocyanate.

8. A method for preparing the self-repairing and self-cleaning coating according to any one of claims 1 to 7, the method comprising stirring and mixing all the raw materials in the A component to obtain the A component; stirring and mixing all the raw materials in the B component to obtain the B component, thereby obtaining a two-component self-repairing and self-cleaning coating; Preferably, the stirring and mixing (the stirring and mixing can be the stirring and mixing when preparing component A or the stirring and mixing when preparing component B) has a rotation speed of 100 r / min to 800 r / min, preferably 300 r / min to 600 r / min; Preferably, the stirring and mixing (the stirring and mixing can be the stirring and mixing when preparing component A or the stirring and mixing when preparing component B) is at a temperature of 20°C to 50°C, preferably room temperature; Preferably, the stirring and mixing (the stirring and mixing may be the stirring and mixing during the preparation of component A or the stirring and mixing during the preparation of component B) takes place for 20 to 60 minutes, preferably for 30 to 50 minutes.

9. A self-repairing and self-cleaning coating, which is made of the self-repairing and self-cleaning coating according to any one of claims 1 to 7.

10. A method for preparing the self-repairing and self-cleaning coating according to claim 9, the method comprising the step of mixing the component A and the component B and curing them on a substrate to form the coating; or the method comprising the step of curing the self-repairing and self-cleaning coating according to any one of claims 1 to 7 on a substrate to form the coating; Preferably, the mass ratio of component A to component B is 1.5 to 2.5:1, preferably 2:1; Preferably, the curing temperature is 10 to 80°C, preferably 20 to 70°C, and more preferably 60°C; Preferably, the curing time is 5 to 10 hours, preferably 5 to 8 hours; Preferably, the substrate is selected from concrete, wood, glass, metal, preferably glass.

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