Wear-resistant ceramic coating and preparation method thereof

Abstract

The invention discloses a wear-resistant ceramic coating and a preparation method thereof, and belongs to the technical field of coatings. The invention relates to a wear-resistant ceramic coating which comprises the following raw material components in percentage by mass: 60-80% of a component A and 20-40% of a component B, the component A is prepared from raw materials in percentage by mass as follows: 30%-50% of a water-based inorganic nano ceramic emulsion, 1%-4% of pigment, 10%-20% of filler, 2%-6% of modified graphene, 0.1%-0.5% of a wetting dispersant, 0.1%-0.5% of a defoaming agent, 1%-5% of a thickening agent and the balance of water; wherein the water-based inorganic nano ceramic emulsion is prepared from the following components in percentage by weight: 30%-50% of silica sol, 20%-30% of silane, 0.1%-10% of a surfactant and the balance of water; the component B is a curing agent; the modified graphene is polydopamine-coated composite modified graphene oxide. The wear resistance of the obtained coating reaches 1300 times or above, and the aging resistance reaches 3400 h or above.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a wear-resistant ceramic coating and a preparation method thereof. Background Art

[0002] Ceramic coatings are a new type of coating material based on organic and inorganic hybrid technology. Because their main structure is a covalently cross-linked inorganic (metal oxide, non-metal oxide, etc.) network, they have many performance advantages that traditional organic coatings cannot match, such as high hardness, friction resistance, flame retardancy, super weather resistance, low surface energy, and resistance to chemical solvents. They are an excellent choice for preparing high-temperature resistance and high-durability special coatings. Ceramic coatings are called ceramic coatings because their performance after curing is similar to that of ceramic materials. Nano water-based ceramic coatings have been widely used in various industrial fields due to their excellent comprehensive performance and green, environmentally friendly and energy-saving advantages, and can provide good protection and decorative effects. Silicone ceramic coatings are a commonly used ceramic coating. The coatings formed have the advantages of high hardness, good weather resistance, safety and non-toxicity.

[0003] Patent CN113004723A discloses a high-temperature-resistant, high-heat-dissipation graphene water-based nanoceramic coating and its preparation method. The patent claims that the coating improves wear resistance by adding graphene to a water-based nanoceramic oil. However, graphene itself suffers from poor dispersibility, hindering its ability to enhance wear resistance. Summary of the Invention

[0004] The present invention provides a wear-resistant ceramic coating and a preparation method thereof, which can solve the problem in the background art that graphene itself has poor dispersibility and is not easy for graphene to play its reinforcing role.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a wear-resistant ceramic coating, the raw material components including component A and component B, wherein component A accounts for 60-80% and component B accounts for 20-40% by mass; the raw material mass percentages of component A are: 30-50% aqueous inorganic nanoceramic emulsion, 1-4% pigment, 10-20% filler, 2-6% modified graphene, 0.1-0.5% wetting dispersant, 0.1-0.5% defoaming agent, 1-5% thickener, and the balance is water; wherein the aqueous inorganic nanoceramic emulsion contains the following ingredients in mass percentage: 30%-50% silica sol, 20%-30% silane, 0.1%-10% surfactant, and the balance is water; the component B is a curing agent; and the modified graphene is polydopamine@composite modified graphene oxide.

[0007] Furthermore, the silica sol has a particle size of 50-120 nm and a pH value of 9-10.

[0008] Furthermore, the surfactant is one or a mixture of several quaternary ammonium cationic surfactants.

[0009] Furthermore, the silane is a mixture of one or more alkoxysilanes; the alkoxysilane is one or more of methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, glycidoxypropylmethyldimethoxysilane, and glycidoxypropylmethyldiethoxysilane.

[0010] Furthermore, the pigment is at least one of titanium dioxide, pearlescent pigment, fluorescent pigment, and metallic pigment; the filler is at least one of calcium sulfate whiskers, magnesium sulfate whiskers, aluminum borate whiskers, and titanate platelets; the wetting and dispersing agent is Digo 245; the defoaming agent is BYK015; and the thickener is BYK420.

[0011] Furthermore, the preparation method of the modified graphene is:

[0012] A1. Weigh benzotriazole, tridecafluorooctyltrimethoxysilane, acetic acid, anhydrous ethanol, and deionized water into a beaker, heat the liquid to 60°C and magnetically stir for 1-2 hours, then add graphene oxide, stir at room temperature for 5 minutes, transfer to an ultrasonicator, and ultrasonically disperse for 1 hour. Finally, stir at 60°C for 6 hours, filter, wash, and dry to obtain a composite modified graphene oxide.

[0013] The usage ratio of benzotriazole, tridecafluorooctyltrimethoxysilane, acetic acid, anhydrous ethanol, deionized water and graphene oxide is 0.5-1 g: 1-2 g: 1 mL: 10 mL: 50 mL: 0.5 g.

[0014] In the above steps, the -OH bond after hydrolysis of tridecafluorooctyltrimethoxysilane will undergo a condensation reaction with the hydroxyl group on the surface of graphene oxide to form Si-O-Si. The -OH after hydrolysis will also undergo hydrogen bonding with the -NH2 in the benzotriazole structure, thereby obtaining a composite modified graphene oxide. The present invention uses tridecafluorooctyltrimethoxysilane as a bridge to combine benzotriazole with graphene oxide, which is beneficial to reduce the precipitation problem of ultraviolet absorbers and improve the aging resistance of ceramic coatings. Both tridecafluorooctyltrimethoxysilane and benzotriazole can significantly improve the dispersibility of graphene oxide through the steric hindrance effect, thereby helping to improve the wear resistance of the slurry. Tridecafluorooctyltrimethoxysilane also has aging resistance and can work together with benzotriazole to improve the aging resistance of ceramic coatings.

[0015] A2. Take the composite modified graphene oxide, add it to Tris-HCl buffer with pH = 8.5, and ultrasonically treat it for 90 minutes. Then add dopamine hydrochloride, stir it at room temperature for 8-10 hours, centrifuge it, wash it alternately with deionized water and ethanol for 3-5 times, and dry it in vacuum at 60°C to obtain modified graphene.

[0016] The usage ratio of the composite modified graphene oxide, Tris-HCl buffer solution and dopamine hydrochloride is 0.3 g: 300 mL: 0.2-0.4 g.

[0017] The above steps involve the self-polymerization of dopamine, coating the surface of the composite modified graphene oxide with a layer of polydopamine. Polydopamine exhibits strong adhesion, improving the compatibility between the modified graphene and other raw materials, thereby enhancing the overall performance of the slurry. Polydopamine itself also exhibits anti-aging properties, and can synergistically enhance the chemical resistance of the material with tridecafluorooctyltrimethoxysilane and benzotriazole.

[0018] Furthermore, the B component curing agent is aminosilane hydrolyzate or 26208 water-based silicone dispersion.

[0019] In a second aspect, the present invention provides a method for preparing a wear-resistant ceramic coating, comprising the following steps:

[0020] S1. Preparation of inorganic nano-ceramic emulsion: First, one or more silanes are mixed, and after mixing evenly, a surfactant is added and stirred evenly, and then the mixture is added dropwise to the pre-weighed silica sol, and the addition is completed within 30 minutes. Then, the temperature is increased, and the reaction temperature is maintained at 35-80 degrees. The reaction is carried out at a constant temperature for 2-5 hours, and then the measured water is added. The heating is stopped and the temperature is cooled to obtain the inorganic nano-ceramic emulsion;

[0021] S2, the inorganic nano-ceramic emulsion is mixed with the pigment, modified graphene and filler, and dispersed at high speed with a high-speed disperser for 10-30 minutes, and then ground with a horizontal sand mill, and the cooling water is adjusted so that the temperature of the ground material does not exceed 60 degrees, and the grinding time is 1-2 hours;

[0022] S3. After grinding, add additives and water and stir evenly to obtain ceramic coating.

[0023] Beneficial effects of the present invention:

[0024] The present invention incorporates modified graphene into the raw materials. This modified graphene is a polydopamine-modified graphene oxide composite, prepared by co-modifying benzotriazole and tridecafluorooctyltrimethoxysilane. This significantly improves the dispersibility of the graphene in the system and enhances the corrosion resistance of the coating, resulting in a coating with a wear resistance of over 1,300 times and an aging resistance of over 3,400 hours. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0026] Preparation Example 1

[0027] The preparation method of modified graphene in this preparation example is:

[0028] A1. Weigh 0.5 g of benzotriazole, 1 g of tridecafluorooctyltrimethoxysilane, 1 mL of acetic acid, 10 mL of anhydrous ethanol, and 50 mL of deionized water into a beaker, heat the above liquid to 60°C and stir magnetically for 1 hour, then add 0.5 g of graphene oxide, stir at room temperature for 5 minutes, transfer to an ultrasonic instrument, and ultrasonically disperse for 1 hour. Finally, stir at 60°C for 6 hours, filter, wash, and dry to obtain a composite modified graphene oxide;

[0029] A2. Take 0.3 g of composite modified graphene oxide, add it to 300 mL of Tris-HCl buffer with pH = 8.5, and ultrasonicate it for 90 min. Then add 0.2 g of dopamine hydrochloride, stir it at room temperature for 8 h, centrifuge it, wash it alternately with deionized water and ethanol three times, and dry it in vacuum at 60°C to obtain modified graphene.

[0030] Preparation Example 2

[0031] The preparation method of modified graphene in this preparation example is:

[0032] A1. Weigh 1 g of benzotriazole, 2 g of tridecafluorooctyltrimethoxysilane, 1 mL of acetic acid, 10 mL of anhydrous ethanol, and 50 mL of deionized water into a beaker, heat the above liquid to 60°C and stir magnetically for 2 hours, then add 0.5 g of graphene oxide, stir at room temperature for 5 minutes, transfer to an ultrasonicator, and ultrasonically disperse for 1 hour. Finally, stir at 60°C for 6 hours, filter, wash, and dry to obtain a composite modified graphene oxide;

[0033] A2. Take 0.3 g of composite modified graphene oxide, add it to 300 mL of Tris-HCl buffer with pH = 8.5, and ultrasonicate it for 90 min. Then add 0.4 g of dopamine hydrochloride, stir it at room temperature for 10 h, centrifuge it, wash it alternately with deionized water and ethanol 5 times, and dry it in vacuum at 60°C to obtain modified graphene.

[0034] Example 1

[0035] A wear-resistant ceramic coating comprises raw material components including component A and component B, wherein component A accounts for 60% and component B accounts for 40% by mass. The raw material percentages of component A are as follows: 30% aqueous inorganic nanoceramic emulsion, 1% titanium dioxide, 10% aluminum borate whiskers, 2% modified graphene obtained in Preparation Example 1, 0.1% Digo 245, 0.1% BYK015, 1% BYK420, and the balance is water. The aqueous inorganic nanoceramic emulsion comprises the following components and weight proportions: 30% silica sol with a particle size of 50 nm and a pH of 9, 20% silane, 0.1% quaternary ammonium cationic surfactant, and the balance is water. Component B is an aminosilane hydrolyzate.

[0036] Its preparation method is:

[0037] S1. Preparation of an inorganic nano-ceramic emulsion: First, γ-methacryloxypropyltrimethoxysilane was mixed, and after mixing evenly, a surfactant was added and stirred evenly. Then, the mixture was added dropwise to the pre-weighed silica sol. The addition was completed within 30 minutes. Then, the temperature was raised and the reaction temperature was maintained at 40 degrees. The reaction was carried out at a constant temperature for 2 hours. Then, the measured amount of water was added, the heating was stopped, and the temperature was cooled to obtain an inorganic nano-ceramic emulsion.

[0038] S2, the inorganic nano ceramic emulsion is mixed with pigment, modified graphene and filler, and high-speed dispersion is carried out with a high-speed disperser, and the dispersion time is 30 minutes, and then a horizontal sand mill is adopted for grinding, and the cooling water is adjusted so that the grinding material temperature does not exceed 60 degrees, and the grinding time is 2 hours;

[0039] S3. After grinding, add additives and water and stir evenly to obtain ceramic coating.

[0040] Example 2

[0041] A wear-resistant ceramic coating comprises raw material components including component A and component B, wherein component A accounts for 60% and component B accounts for 40% by mass. The raw material percentages of component A are as follows: 40% aqueous inorganic nanoceramic emulsion, 2% titanium dioxide, 15% aluminum borate whiskers, 3% modified graphene obtained in Preparation Example 1, 0.3% Digo 245, 0.3% BYK015, 3% BYK420, and the balance is water. The aqueous inorganic nanoceramic emulsion comprises the following components and weight proportions: 40% silica sol with a particle size of 50 nm and a pH of 9, 25% silane, 5% quaternary ammonium cationic surfactant, and the balance is water. Component B is an aminosilane hydrolyzate.

[0042] The preparation method is the same as that in Example 1.

[0043] Example 3

[0044] A wear-resistant ceramic coating comprises raw material components including component A and component B, wherein component A accounts for 60% and component B accounts for 40% by mass. The raw material percentages of component A are as follows: 50% aqueous inorganic nanoceramic emulsion, 4% titanium dioxide, 20% aluminum borate whiskers, 4% modified graphene obtained in Preparation Example 2, 0.5% Digo 245, 0.5% BYK015, 0.5% BYK420, and the balance is water. The aqueous inorganic nanoceramic emulsion comprises the following components and weight proportions: 50% silica sol with a particle size of 50 nm and a pH of 9, 30% silane, 10% quaternary ammonium cationic surfactant, and the balance is water. Component B is an aminosilane hydrolyzate.

[0045] The preparation method is the same as that in Example 1.

[0046] Example 4

[0047] The difference between this embodiment and embodiment 3 is that the modified graphene obtained in preparation example 2 is 5%, and the remaining raw materials and steps are the same as those in embodiment 3.

[0048] Example 5

[0049] The difference between this embodiment and embodiment 3 is that the modified graphene obtained in preparation example 2 is 6%, and the remaining raw materials and steps are the same as those in embodiment 3.

[0050] Comparative Example 1

[0051] Compared with Example 1, this comparative example is different in that polydopamine is omitted in the preparation process of modified graphene. The specific steps are as follows:

[0052] Weigh 0.5 g of benzotriazole, 1 g of tridecafluorooctyltrimethoxysilane, 1 mL of acetic acid, 10 mL of anhydrous ethanol and 50 mL of deionized water into a beaker, heat the above liquid to 60°C and magnetically stir for 1 hour, then add 0.5 g of graphene oxide, stir at room temperature for 5 minutes, then transfer to an ultrasonic instrument and ultrasonically disperse for 1 hour, finally stir at 60°C for 6 hours, filter, wash and dry to obtain modified graphene.

[0053] The remaining materials and steps are the same as in Example 1.

[0054] Comparative Example 2

[0055] Compared with Example 1, this comparative example is different in that benzotriazole and polydopamine are omitted in the preparation process of modified graphene. The specific steps are as follows:

[0056] Weigh 1 g of tridecafluorooctyltrimethoxysilane, 1 mL of acetic acid, 10 mL of anhydrous ethanol and 50 mL of deionized water into a beaker, heat the above liquid to 60°C and magnetically stir for 1 hour, then add 0.5 g of graphene oxide, stir at room temperature for 5 minutes, then transfer to an ultrasonic instrument and ultrasonically disperse for 1 hour, finally stir at 60°C for 6 hours, filter, wash and dry to obtain modified graphene.

[0057] The remaining materials and steps are the same as in Example 1.

[0058] Comparative Example 3

[0059] This comparative example is different from Example 1 in that benzotriazole and polydopamine are omitted in the preparation process of modified graphene, and tridecafluorooctyltrimethoxysilane is replaced by KH550. The specific steps are as follows:

[0060] Weigh 1 g of KH550, 1 mL of acetic acid, 10 mL of anhydrous ethanol and 50 mL of deionized water into a beaker, heat the above liquid to 60°C and magnetically stir for 1 hour, then add 0.5 g of graphene oxide, stir at room temperature for 5 minutes, transfer to an ultrasonic instrument and ultrasonically disperse for 1 hour, finally stir at 60°C for 6 hours, filter, wash and dry to obtain modified graphene.

[0061] The remaining materials and steps are the same as in Example 1.

[0062] Comparative Example 4

[0063] In this comparative example, the modified graphene is directly replaced by graphene, and the remaining raw materials and steps are the same as those in Example 1.

[0064] Comparative Example 5

[0065] In this comparative example, modified graphene was not added, and the remaining raw materials and steps were the same as in Example 1.

[0066] Comparative Example 6

[0067] The difference between this comparative example and Example 1 is that the modified graphene obtained in Preparation Example 1 is 4%, and the remaining raw materials and steps are the same as Example 1.

[0068] Comparative Example 7

[0069] Compared with Example 5, this comparative example is different in that the modified graphene obtained in Preparation Example 2 is 7%, and the remaining raw materials and steps are the same as Example 5.

[0070] Performance tests were performed on Examples 1 to 5 and Comparative Examples 1 to 7. The test items are as follows, and the results are shown in Table 1:

[0071] 1. Wear resistance test: Wear resistance test is carried out by RCA paper tape method.

[0072] 2. Aging resistance: tested in accordance with the national standard GB / T 14522-2008

[0073] Table 1

[0074]

[0075]

[0076] As can be seen from Table 1, the wear resistance and aging resistance of the ceramic coatings of Examples 1 to 5 are better than those of Comparative Examples 1 to 7, while the wear resistance and aging resistance of Comparative Examples 6 and 7 are lower than those of Example 1 and 5, respectively. This indicates that excessive or insufficient addition of modified graphene can affect the wear resistance and aging resistance of the coatings, and the amount of modified graphene added in the present invention is the optimal amount.

[0077] The above disclosures are only a few specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A wear-resistant ceramic coating, characterized in that: The raw material components include component A and component B, wherein component A accounts for 60-80% by mass and component B accounts for 20-40% by mass; The raw materials of component A are as follows by mass percentage: 30-50% aqueous inorganic nano-ceramic emulsion, 1-4% pigment, 10-20% filler, 2-6% modified graphene, 0.1-0.5% wetting and dispersing agent, 0.1-0.5% defoaming agent, 1-5% thickener, and the balance is water; The aqueous inorganic nano-ceramic emulsion comprises the following components in percentage by mass: 30%-50% silica sol, 20%-30% silane, 0.1%-10% surfactant, and the balance is water; The B component is a curing agent; The modified graphene is polydopamine@composite modified graphene oxide.

2. The wear-resistant ceramic coating according to claim 1, characterized in that: The silica sol has a particle size of 50-120 nm and a pH value of 9-10.

3. The wear-resistant ceramic coating according to claim 1, characterized in that: The surfactant is one or a mixture of several quaternary ammonium cationic surfactants.

4. The wear-resistant ceramic coating according to claim 1, characterized in that: The silane is a mixture of one or more alkoxysilanes; the alkoxysilane is one or more of methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, glycidoxypropylmethyldimethoxysilane, and glycidoxypropylmethyldiethoxysilane.

5. The wear-resistant ceramic coating according to claim 1, characterized in that: The pigment is at least one of titanium dioxide, pearlescent pigment, fluorescent pigment, and metallic pigment; the filler is at least one of calcium sulfate whiskers, magnesium sulfate whiskers, aluminum borate whiskers, and titanate platelets; the wetting and dispersing agent is Digo 245; the defoaming agent is BYK015; and the thickener is BYK420.

6. The wear-resistant ceramic coating according to claim 1, characterized in that: The preparation method of the modified graphene is: A1. Weigh benzotriazole, tridecafluorooctyltrimethoxysilane, acetic acid, anhydrous ethanol, and deionized water, stir at 60°C for 1-2 hours, then add graphene oxide, stir at room temperature for 5 minutes, and then ultrasonicate for 1 hour. Finally, stir at 60°C for 6 hours, filter, wash, and dry to obtain a composite modified graphene oxide. A2. Take the composite modified graphene oxide, add it to Tris-HCl buffer with pH = 8.5, sonicate for 90 minutes, then add dopamine hydrochloride, stir at room temperature for 8-10 hours, centrifuge, wash alternately with deionized water and ethanol 3-5 times, and dry in vacuum at 60°C to obtain modified graphene.

7. The wear-resistant ceramic coating according to claim 6, characterized in that: In step A1, the usage ratio of benzotriazole, tridecafluorooctyltrimethoxysilane, acetic acid, anhydrous ethanol, deionized water, and graphene oxide is 0.5-1 g: 1-2 g: 1 mL: 10 mL: 50 mL: 0.5 g.

8. The wear-resistant ceramic coating according to claim 6, characterized in that: In step A2, the usage ratio of the composite modified graphene oxide, Tris-HCl buffer, and dopamine hydrochloride is 0.3 g:300 mL:0.2-0.4 g.

9. The wear-resistant ceramic coating according to claim 1, characterized in that: The B component curing agent is aminosilane hydrolyzate or 26208 water-based organosilicon dispersion.

10. A method for preparing a wear-resistant ceramic coating, for preparing the wear-resistant ceramic coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Preparation of inorganic nano-ceramic emulsion: First, one or more silanes are mixed, and after mixing evenly, a surfactant is added and stirred evenly, and then the mixture is added dropwise to the pre-weighed silica sol, and the addition is completed within 30 minutes. Then, the temperature is increased, and the reaction temperature is maintained at 35-80 degrees. The reaction is carried out at a constant temperature for 2-5 hours, and then water is added. The heating is stopped and the temperature is cooled to obtain the inorganic nano-ceramic emulsion; S2, the inorganic nano-ceramic emulsion is mixed with the pigment, modified graphene and filler, and dispersed at high speed with a high-speed disperser for 10-30 minutes, and then ground with a horizontal sand mill, and the cooling water is adjusted so that the temperature of the ground material does not exceed 60 degrees, and the grinding time is 1-2 hours; S3. After grinding, add additives and water and stir evenly to obtain ceramic coating.

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