A superhydrophobic and mildew-proof stone carving protection coating and its preparation method

Abstract

The present invention discloses a superhydrophobic and mildew-proof stone carving protection coating and a preparation method thereof, belonging to the field of stone carving protection coatings. The bottom layer of the superhydrophobic and mildew-proof stone carving protection coating is a polydopamine layer, the middle layer is a cage-shaped polysiloxane and a linear polysiloxane layer, and the surface layer is a zinc salt-crosslinked polysiloxane network structure. Among them, the three-dimensional cage-shaped structure and the linear structure of polysiloxane cooperate to form a dense hydrophobic intermediate layer, and the polysiloxane network on the surface layer also contains zinc nanoparticles. Compared with existing products, the superhydrophobic and mildew-proof stone carving protection coating of the present invention has good hydrophobic stability and remarkable mildew-proof effect on stones.

Description

Technical Field

[0001] The present invention relates to the field of stone carving protection coatings, and particularly to a superhydrophobic and mildew-proof stone carving protection coating and a preparation method thereof. Background Art

[0002] Stone carving protection coatings are designed to provide physical and chemical protection to the surface of stone carvings, reduce the damage to cultural relics caused by environmental factors and the aging process, and extend their lifespan. Due to their good weather resistance, chemical erosion resistance, breathability, flexibility, etc., silicone materials are widely used in stone carving protection coatings. Silicone materials can form a low surface energy coating with a certain thickness on the surface of stone carvings, with excellent waterproofing effect. Even if it breaks under environmental influence, there are still long polymer chains grafted on the surface of the stone carving, which can extend the residence time of hydrophobic segments on the surface. In the further hydrophobic modification of silicone materials by researchers, most use linear organosiloxanes to graft hydrophobic groups onto the material surface by combining with hydroxyl groups on the material surface to improve hydrophobic performance. Shah et al. formed a rough surface on wood by the accumulation of nano-aluminum oxide particles, and then chemically modified it with polydimethylsiloxane to obtain a superhydrophobic coating. (Shah, S.M., Zulfiqar, U., Hussain, S.Z., et al. A durable super hydrophobic coating for the protection of wood materials[J]. Materials Letters, 2017, 203: 17-20.) Some also use cross-linked silicones, such as silicone rubber, silicone resin, etc., for hydrophobic modification of materials. Due to their high molecular cross-linking density, the formed hydrophobic coatings also have good mechanical properties. Tu et al. sprayed an aqueous perfluoroalkyl methacrylate copolymer emulsion mixed with titanium dioxide nanoparticles onto a polydimethylsiloxane pre-coated substrate to prepare a superhydrophobic coating on the wood surface. The obtained coating showed good ultraviolet resistance and certain tolerance to mechanical damage. (Tu, K., Wang, X., Kong, L., et al. Facile preparation of mechanically durable, self-healing and multifunctional superhydrophobic surfaces on solid wood[J]. Materials & Design, 2018, 140: 30-36.)

[0003] However, stone carving protection coatings often require multiple functions to be integrated, and some functions are closely related. For example, in the process of mildew prevention, both a hydrophobic agent and a mildew-proof agent are indispensable, and the synergistic effect is optimal.

[0004] Therefore, it is necessary to develop a composite coating for stone carving protection with multiple functions. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a superhydrophobic and mildew-proof stone carving protection coating and a preparation method thereof.

[0006] The object of the present invention can be achieved by the following technical solutions:

[0007] A superhydrophobic and mildew-proof stone carving protection coating, comprising:

[0008] A polydopamine layer;

[0009] A cage-shaped polysiloxane connected to the polydopamine layer;

[0010] A linear polysiloxane layer covering the cage-shaped polysiloxane; and

[0011] A zinc salt-crosslinked polysiloxane network structure formed on the linear polysiloxane layer, wherein the polysiloxane network structure contains zinc nanoparticles.

[0012] Optionally, the cage-shaped polysiloxane is one or a mixture of more of trifluoropropyl cage-shaped polyhedral oligomeric silsesquioxane, hexafluoroisopropyl cage-shaped polyhedral oligomeric silsesquioxane, n-butyl cage-shaped polyhedral oligomeric silsesquioxane, and phenyl cage-shaped polyhedral oligomeric silsesquioxane.

[0013] Optionally, the linear polysiloxane is a polysiloxane modified with a carboxyl imide side chain, and the polysiloxane is one or a mixture of more of polymethylsiloxane, polydimethylsiloxane, polymethylhydrosiloxane, and polymethylvinylsiloxane.

[0014] Optionally, the zinc salt is a divalent zinc salt.

[0015] A preparation method of a superhydrophobic and mildew-proof stone carving protection coating, comprising the following steps:

[0016] Step 1: Prepare a dopamine solution, spray it on the surface of the target object after ultrasonic treatment, and dry it.

[0017] Step 2: Prepare a cage-shaped polysiloxane solution, spray it on the surface treated in Step 1 after ultrasonic treatment, and dry it.

[0018] Step 3: Prepare a linear polysiloxane solution, spray it on the surface treated in Step 2 after ultrasonic treatment, and dry it.

[0019] Step 4: Drop an excessive amount of zinc salt solution into sodium methyl silicate until the pH of the solution is 11, stir to obtain a colloidal suspension, mix it with the linear polysiloxane solution, spray it on the surface treated in Step 3 after ultrasonic treatment, and dry it.

[0020] Optionally, in the step 2, the mass percentage concentration of the cage-shaped polysiloxane solution is 2% to 5%.

[0021] Optionally, in the step 3, the mass percentage concentration of the linear polysiloxane solution is 3% to 7%.

[0022] Optionally, the linear polysiloxane is a polysiloxane modified with side-chain carboxyl imine and is prepared by reacting an amino polysiloxane with acrylic acid.

[0023] Optionally, the cage-shaped polysiloxane is one or a mixture of more than one of trifluoropropyl cage-shaped polyhedral oligomeric silsesquioxane, hexafluoroisopropyl cage-shaped polyhedral oligomeric silsesquioxane, n-butyl cage-shaped polyhedral oligomeric silsesquioxane, and phenyl cage-shaped polyhedral oligomeric silsesquioxane.

[0024] The third aspect of the present invention relates to the application of the above protective coating in the anti-mildew protection of stone materials.

[0025] Advantages of the present invention:

[0026] (1) By introducing cage-shaped polyhedral oligomeric silsesquioxane into the intermediate layer, its unique three-dimensional cage structure of Si-O-Si bonds is very stable, and the fluorine-containing groups on the side chains have extremely low surface energy. As a nano-filler, it can greatly increase the surface roughness. Cooperating with the linear polysiloxane layer, it forms a "brick-cement" dense structure, further improving the hydrophobic performance.

[0027] (2) In the surface layer, zinc nanoparticles are prepared from zinc salts and sodium methyl silicate. The excess zinc salts form stable complexes with carboxyl imine ligands to obtain a cross-linked polysiloxane network. The zinc-based surface layer has dual functions of anti-mildew and anti-ultraviolet aging.

[0028] (3) The surface layer covers and seals the intermediate layer, greatly improving the hydrophobic stability of the composite coating. Description of the Drawings

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] Figure 1 It is a schematic diagram of the components of the super-hydrophobic and anti-mildew stone carving protection coating prepared by the present invention.

[0031] The names of the components corresponding to the labels in the figure are as follows: 1 - stone carving material; 2 - bottom layer of polydopamine; 3 - intermediate layer of super-hydrophobic layer, 4 - surface layer of cross-linked polysiloxane layer, 5 - cage-shaped polysiloxane; 6 - linear polysiloxane layer; 7 - zinc ion complex; 8 - zinc nanoparticles. Detailed Embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0033] As Figure 1 shown, the present invention discloses a superhydrophobic and mildew-proof stone carving protection coating. The bottom layer of the protection coating is a polydopamine layer, the middle layer is a cage-shaped polysiloxane and a linear polysiloxane layer, and the surface layer is a zinc salt-crosslinked polysiloxane network structure. Among them, the three-dimensional cage-shaped structure and the linear structure of polysiloxane cooperate to form a dense hydrophobic intermediate layer, and the polysiloxane network on the surface layer also contains zinc nanoparticles.

[0034] Next, specific embodiments are further disclosed, which relate to a preparation method of a superhydrophobic and mildew-proof stone carving protection coating.

[0035] Example 1

[0036] The specific preparation steps of a superhydrophobic and mildew-proof stone carving protection coating are as follows:

[0037] (1) Prepare a dopamine solution with a concentration of 2 mg / mL, spray it on the surface of the object after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times;

[0038] (2) Prepare a solution of trifluoropropyl cage-shaped polyhedral oligomeric silsesquioxane with a mass concentration of 2%, spray it on the surface treated in step 1 after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times.

[0039] (3) Prepare carboxyl imine-type polymethylsiloxane by reacting aminopolymethylsiloxane with acrylic acid. Prepare a carboxyl imine-type polymethylsiloxane solution with a mass percentage concentration of 7%, spray it on the surface treated in step 2 after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times.

[0040] (4) Drop an excessive amount of zinc chloride solution into sodium methyl silicate until the pH of the solution is 11, stir to obtain a colloidal suspension, mix it with a certain amount of the carboxyl imine-type polymethylsiloxane solution obtained in step 3, spray it on the surface treated in step 3 after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times.

[0041] The water contact angle of the superhydrophobic and mildew-proof stone carving protection coating prepared in Example 1 is 154.3°, and the contact angle becomes 152.8° after 10 times of water washing.

[0042] Example 2

[0043] The specific preparation steps of a superhydrophobic and mildew-proof stone carving protective coating are as follows:

[0044] (1) Prepare a dopamine solution with a concentration of 2 mg / mL. After ultrasonic treatment for a period of time, spray it on the surface of the object and let it dry naturally for 10 min. Repeat this operation 5 times;

[0045] (2) Prepare a solution of hexafluoroisopropylcage polyhedral oligomeric silsesquioxane with a mass concentration of 3%. After ultrasonic treatment for a period of time, spray it on the surface treated in step 1 and let it dry naturally for 10 min. Repeat this operation 5 times.

[0046] (3) Prepare carboxyl imine type polydimethylsiloxane by reacting aminopropyldimethylsiloxane with acrylic acid. Prepare a carboxyl imine type polydimethylsiloxane solution with a mass percentage concentration of 6%. After ultrasonic treatment for a period of time, spray it on the surface treated in step 2 and let it dry naturally for 10 min. Repeat this operation 5 times.

[0047] (4) Drop an excessive amount of zinc sulfate solution into sodium methyl silicate until the pH of the solution is 11, stir to obtain a colloidal suspension, mix it with a certain amount of the carboxyl imine type polydimethylsiloxane solution obtained in step 3, after ultrasonic treatment for a period of time, spray it on the surface treated in step 3 and let it dry naturally for 10 min. Repeat this operation 5 times.

[0048] The water contact angle of the superhydrophobic and mildew-proof stone carving protective coating prepared in Example 2 is 153.5°. After 10 times of water washing, the contact angle becomes 151.4°.

[0049] Example 3

[0050] The specific preparation steps of a superhydrophobic and mildew-proof stone carving protective coating are as follows:

[0051] (1) Prepare a dopamine solution with a concentration of 2 mg / mL. After ultrasonic treatment for a period of time, spray it on the surface of the object and let it dry naturally for 10 min. Repeat this operation 5 times;

[0052] (2) Prepare a solution of n-butylcage polyhedral oligomeric silsesquioxane with a mass concentration of 4%. After ultrasonic treatment for a period of time, spray it on the surface treated in step 1 and let it dry naturally for 10 min. Repeat this operation 5 times.

[0053] (3) Prepare carboxyl imine type polymethylhydrosiloxane by reacting aminopropylmethylhydrosiloxane with acrylic acid. Prepare a carboxyl imine type polymethylhydrosiloxane solution with a mass percentage concentration of 5%. After ultrasonic treatment for a period of time, spray it on the surface treated in step 2 and let it dry naturally for 10 min. Repeat this operation 5 times.

[0054] (4) An excessive amount of zinc chloride solution is dropped into sodium methyl silicate until the pH of the solution reaches 11, and a colloidal suspension is obtained by stirring. It is mixed with a certain amount of the carboxyimide-type polymethylhydrogensiloxane solution obtained in step 3, ultrasonicated for a period of time, then sprayed on the surface treated in step 3, and left to dry naturally for 10 min. This operation is repeated 5 times.

[0055] The water contact angle of the superhydrophobic and mildew-proof stone carving protective coating prepared in Example 3 is 151°, and the contact angle becomes 147.9° after 10 times of water washing.

[0056] Example 4

[0057] The specific preparation steps of a superhydrophobic and mildew-proof stone carving protective coating are as follows:

[0058] (1) Prepare a dopamine solution with a concentration of 2 mg / mL, ultrasonicate for a period of time, then spray it on the surface of the object, and leave it to dry naturally for 10 min. This operation is repeated 5 times;

[0059] (2) Prepare a phenyl silsesquioxane solution with a mass concentration of 5%, ultrasonicate for a period of time, then spray it on the surface treated in step 1, and leave it to dry naturally for 10 min. This operation is repeated 5 times.

[0060] (3) Prepare carboxyimide-type polymethylvinylsiloxane by reacting aminopolymethylvinylsiloxane with acrylic acid, prepare a carboxyimide-type polymethylvinylsiloxane solution with a mass percentage concentration of 4%, ultrasonicate for a period of time, then spray it on the surface treated in step 2, and leave it to dry naturally for 10 min. This operation is repeated 5 times.

[0061] (4) An excessive amount of zinc sulfate solution is dropped into sodium methyl silicate until the pH of the solution reaches 11, and a colloidal suspension is obtained by stirring. It is mixed with a certain amount of the carboxyimide-type polymethylvinylsiloxane solution obtained in step 3, ultrasonicated for a period of time, then sprayed on the surface treated in step 3, and left to dry naturally for 10 min. This operation is repeated 5 times.

[0062] The water contact angle of the superhydrophobic and mildew-proof stone carving protective coating prepared in Example 4 is 152.6°, and the contact angle becomes 150.5° after 10 times of water washing.

[0063] Example 5

[0064] The specific preparation steps of a superhydrophobic and mildew-proof stone carving protective coating are as follows:

[0065] (1) Prepare a dopamine solution with a concentration of 2 mg / mL, ultrasonicate for a period of time, then spray it on the surface of the object, and leave it to dry naturally for 10 min. This operation is repeated 5 times;

[0066] (2) Prepare a solution of hexafluoroisopropylcage polyhedral oligomeric silsesquioxane with a mass concentration of 4%, spray it on the surface treated in step 1 after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times.

[0067] (3) Prepare carboxylimine-type polymethylsiloxane by reacting aminopolymethylsiloxane with acrylic acid, prepare a solution of carboxylimine-type polymethylsiloxane with a mass percentage concentration of 3%, spray it on the surface treated in step 2 after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times.

[0068] (4) Drop an excessive amount of zinc chloride solution into sodium methyl silicate until the pH of the solution is 11, stir to obtain a colloidal suspension, mix it with a certain amount of the carboxylimine-type polymethylsiloxane solution obtained in step 3, spray it on the surface treated in step 3 after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times.

[0069] The water contact angle of the prepared superhydrophobic and mildew-proof stone carving protection coating is 153.4°. The contact angle becomes 150.3° after 10 times of water washing. According to the ASTM D3273-16 mildew-proof standard, the mildew-proof properties of the stone carving material and the stone carving material sprayed with the superhydrophobic and mildew-proof stone carving protection coating prepared in Example 5 were tested, with 3 samples in each group. The cultured air-mixed mold was dissolved in a spray bottle and sprayed on the surface of all specimens, and then placed in an environment with a temperature of 23 °C and a humidity of 95%.

[0070] The results show that the unsprayed stone carving will mildew on the 8th day, and the stone carving sprayed with the superhydrophobic and mildew-proof stone carving protection coating prepared in Example 5 will mildew on the 34th day. When the 61-day test ends, the mildew area of the unsprayed stone carving reaches 77.95%, and the mildew area of the stone carving sprayed with the superhydrophobic and mildew-proof stone carving protection coating reaches 12.51%. And on the 30th day, the mold grows more densely on the unsprayed stone carving, and the average infection area is close to 50%. At this time, the stone carving sprayed with the superhydrophobic and mildew-proof stone carving protection coating prepared in Example 5 has not shown any mildew phenomenon.

[0071] Example 6

[0072] The specific preparation steps of a superhydrophobic and mildew-proof stone carving protection coating are as follows:

[0073] (1) Prepare a dopamine solution with a concentration of 2 mg / mL, spray it on the surface of the object after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times;

[0074] (2) Prepare a solution of hexafluoroisopropylcage polyhedral oligomeric silsesquioxane with a mass concentration of 4%, spray it on the surface treated in step 1 after ultrasonic treatment for a period of time, and air-dry it naturally for 10 min. Repeat this operation 5 times.

[0075] (3) Prepare carboxyl imine type polymethylsiloxane by reacting amino polymethylsiloxane with acrylic acid, prepare a carboxyl imine type polymethylsiloxane solution with a mass percentage concentration of 3%, spray it on the surface treated in step 2 after ultrasonic treatment for a period of time, and air dry it naturally for 10 min. Repeat this operation 5 times.

[0076] (4) Drop an excessive amount of zinc chloride and zinc sulfate solution into sodium methyl silicate according to a mass ratio of 4:1 until the pH of the solution is 11, stir to obtain a colloidal suspension, mix it with a certain amount of the carboxyl imine type polymethylsiloxane solution obtained in step 3, spray it on the surface treated in step 3 after ultrasonic treatment for a period of time, and air dry it naturally for 10 min. Repeat this operation 5 times.

[0077] The water contact angle of the prepared superhydrophobic and mildew-proof stone carving protection coating is 154.2°. The contact angle becomes 152.1° after 10 times of water washing. According to the mildew-proof standard of ASTM D3273-16, the mildew-proof properties of the stone carving material and the stone carving material sprayed with the superhydrophobic and mildew-proof stone carving protection coating were tested, with 3 samples in each group. The cultured air mixed mold was dissolved in a spray bottle and sprayed on the surface of all specimens, and placed in an environment with a temperature of 23 °C and a humidity of 95%.

[0078] The results show that the stone carving without the sprayed protection coating will mildew on the 7th day, the stone carving sprayed with the superhydrophobic and mildew-proof stone carving protection coating prepared in Example 6 will mildew on the 41st day. When the 61-day test ends, the mildew area of the stone carving without the sprayed protection coating reaches 79.54%, and the mildew area of the stone carving sprayed with the superhydrophobic and mildew-proof stone carving protection coating prepared in Example 6 reaches 9.68%. And on the 30th day, the mold grows relatively densely on the stone carving without the sprayed protection coating, and the average infection area is close to 54%. At this time, the stone carving sprayed with the superhydrophobic and mildew-proof stone carving protection coating has not shown any mildew phenomenon.

[0079] Comparative Example 1

[0080] The specific preparation steps of a superhydrophobic and mildew-proof stone carving protection coating are as follows:

[0081] (1) Prepare a dopamine solution with a concentration of 2 mg / mL, spray it on the surface of the object after ultrasonic treatment for a period of time, and air dry it naturally for 10 min. Repeat this operation 5 times;

[0082] (2) Prepare carboxyl imine type polymethylhydrogensiloxane by reacting amino polymethylhydrogensiloxane with acrylic acid, prepare a carboxyl imine type polymethylhydrogensiloxane solution with a mass percentage concentration of 7%, spray it on the surface treated in step 1 after ultrasonic treatment for a period of time, and air dry it naturally for 10 min. Repeat this operation 5 times.

[0083] (3) An excessive amount of zinc sulfate solution is dropped into sodium methyl silicate until the pH of the solution reaches 11, and a colloidal suspension is obtained by stirring. It is mixed with a certain amount of the carboxyimide-type polymethylhydrogensiloxane solution obtained in step 3, ultrasonically treated for a period of time, then sprayed on the surface treated in step 2, and naturally dried for 10 min. This operation is repeated 5 times.

[0084] In Comparative Example 1, the cage-shaped polyhedral oligomeric silsesquioxane was not added to the hydrophobic layer. The water contact angle of the superhydrophobic and mildew-proof stone carving protection coating prepared was 127.8°. After 10 water washings, the contact angle became 107.5°. The hydrophobic performance was lower than that of the superhydrophobic and mildew-proof stone carving protection coatings in Examples 1-6.

[0085] Comparative Example 2

[0086] The specific preparation steps of a superhydrophobic and mildew-proof stone carving protection coating are as follows:

[0087] (1) Prepare a dopamine solution with a concentration of 2 mg / mL, ultrasonically treat it for a period of time, then spray it on the surface of the object, and naturally dry it for 10 min. This operation is repeated 5 times;

[0088] (2) Prepare a hexafluoroisopropyl cage-shaped polyhedral oligomeric silsesquioxane solution with a mass concentration of 4%, ultrasonically treat it for a period of time, then spray it on the surface treated in step 1, and naturally dry it for 10 min. This operation is repeated 5 times.

[0089] (3) Carboxyimide-type polymethylvinylsiloxane is prepared by reacting aminopolymethylvinylsiloxane with acrylic acid. Prepare a carboxyimide-type polymethylvinylsiloxane solution with a mass percentage concentration of 6%, ultrasonically treat it for a period of time, then spray it on the surface treated in step 2, and naturally dry it for 10 min. This operation is repeated 5 times.

[0090] The superhydrophobic and mildew-proof stone carving protection coating prepared in Comparative Example 2 has no surface crosslinked polysiloxane layer. Its water contact angle is 141.7°. After 10 water washings, the contact angle becomes 102.6°. According to the ASTM D3273-16 mildew-proof standard, the mildew resistance of the stone carving material and the stone carving material sprayed with the superhydrophobic and mildew-proof stone carving protection coating prepared in Comparative Example 2 was tested, with 3 samples in each group. The cultured air mixed mold was dissolved in a spray bottle and sprayed on the surface of all specimens, and then placed in an environment with a temperature of 23 °C and a humidity of 95%.

[0091] The results showed that the stone carvings without the sprayed protective coating would start to mildew on the 7th day, and the stone carvings sprayed with the superhydrophobic and mildew-proof stone carving protective coating prepared in Comparative Example 2 would also start to mildew on the 7th day. When the 61-day test ended, the mildew area of the stone carvings without the sprayed protective coating reached 75.34%, and the mildew area of the stone carvings sprayed with the superhydrophobic and mildew-proof stone carving protective coating prepared in Comparative Example 2 reached 74.69%, showing no obvious mildew-proof effect. The results indicate that the surface crosslinked layer covers and seals the intermediate layer, which not only improves the hydrophobic stability of the coating but also has a significant mildew-proof effect.

[0092] Based on the results of the above embodiments, the superhydrophobic and mildew-proof stone carving protective coating of the present invention can be applied in the field of protecting stone carvings and stone carving products. More specifically, it can be, but is not limited to, the production and protection fields of cultural relics, artworks, and handicrafts of the stone carving type. At the same time, the superhydrophobic and mildew-proof stone carving protective coating of the present invention can also achieve the same effect when applied in other fields containing stone products, such as the construction field.

[0093] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0094] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A superhydrophobic and mildew-proof stone carving protection coating, characterized in that, Comprising: A polydopamine layer; A cage-shaped polysiloxane connected to the polydopamine layer; A linear polysiloxane layer covering the cage-shaped polysiloxane; And A zinc salt-crosslinked polysiloxane network structure formed on the linear polysiloxane layer, the polysiloxane network structure containing zinc nanoparticles; the linear polysiloxane is a polysiloxane modified with a side-chain carboxyl imine and is prepared by reacting an amino polysiloxane with acrylic acid; The cage-shaped polysiloxane is one or a mixture of more of trifluoropropyl cage-shaped polyhedral oligomeric silsesquioxane, hexafluoroisopropyl cage-shaped polyhedral oligomeric silsesquioxane, n-butyl cage-shaped polyhedral oligomeric silsesquioxane, and phenyl cage-shaped polyhedral oligomeric silsesquioxane.

2. The superhydrophobic and mildew-proof stone carving protection coating according to claim 1, characterized in that, The zinc salt is a divalent zinc salt.

3. A preparation method of a superhydrophobic and mildew-proof stone carving protection coating, characterized in that, Including the following steps: Step 1: Prepare a dopamine solution, spray it on the surface of the target object after ultrasonic treatment, and dry it. Step 2: Prepare a cage-shaped polysiloxane solution, spray it on the surface treated in Step 1 after ultrasonic treatment, and dry it. Step 3: Prepare a linear polysiloxane solution, spray it on the surface treated in Step 2 after ultrasonic treatment, and dry it. Step 4: Drop an excessive amount of zinc salt solution into sodium methyl silicate until the pH of the solution is 11, stir to obtain a colloidal suspension, mix it with the linear polysiloxane solution, spray it on the surface treated in Step 3 after ultrasonic treatment, and dry it. Among them, the linear polysiloxane is a polysiloxane modified with a side-chain carboxyl imine and is prepared by reacting an amino polysiloxane with acrylic acid; The cage-shaped polysiloxane is one or a mixture of more of trifluoropropyl cage-shaped polyhedral oligomeric silsesquioxane, hexafluoroisopropyl cage-shaped polyhedral oligomeric silsesquioxane, n-butyl cage-shaped polyhedral oligomeric silsesquioxane, and phenyl cage-shaped polyhedral oligomeric silsesquioxane.

4. The preparation method of a superhydrophobic and mildew-proof stone carving protection coating according to claim 3, characterized in that, In Step 2, the mass percentage concentration of the cage-shaped polysiloxane solution is 2% to 5%.

5. The preparation method of a superhydrophobic and mildew-proof stone carving protection coating according to claim 3, characterized in that, In Step 3, the mass percentage concentration of the linear polysiloxane solution is 3% to 7%.

6. Application of the protection coating according to any one of claims 1 or 2 in the mildew-proof protection of stone materials.

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