A curing-free water-based ceramic coating

Abstract

This application discloses a curing-free water-based ceramic coating, prepared by mixing components A and B in a mass ratio of 1:1 to 2:1. Component A comprises silica sol and methyl hydrogenated silicone oil, with a solids content of 20-40%. Component B comprises a silane coupling agent and a catalyst, with the effective content of the silane coupling agent exceeding 98%. After formulation, the water-based ceramic coating can be sprayed immediately without curing, saving significant curing time. The resulting ceramic coating, after high-temperature curing, exhibits properties such as hardness, adhesion, temperature resistance, and non-stick properties that are comparable to, and even surpass, existing ceramic coatings.

Description

Technical Field

[0001] The present application relates to the field of polymer materials, and in particular to a curing-free water-based ceramic coating. Background Art

[0002] Currently, ceramic coatings on the market are made from silica sol and silane, catalyzed by organic acids. Through hydrolysis and polymerization, they form a cross-linked Si-O-Si structure, resulting in a ceramic-like surface. These coatings are highly resistant to high temperatures, neither decomposing nor releasing toxic gases. They also possess high hardness, wear resistance, and a non-stick property. However, before use, the coatings require several hours or more of high-speed rolling aging. This allows the silane, under the action of the catalyst, to fully hydrolyze and polymerize with the silica particles in the silica sol in water, allowing for cross-linking.

[0003] Some technicians in this field are developing aging-free ceramic coatings, but there are still major defects. For example, CN201910197608 discloses aging-free high-performance ceramic coatings and their preparation methods, which utilize silane to hydrolyze in water under the action of organic acid catalysis and then undergo polymerization reaction with silica particles in silica sol to cross-link and solidify to form a coating. However, the ceramic coating prepared by this method has very poor immediate effect. Many shrinkage holes and particles will appear on the surface of the coating, because the hydrolysis and cross-linking of silane requires a relatively slow and long self-crosslinking cycle without undergoing high-speed rolling aging. In addition, the flash points of many silanes in this method are relatively low, and the flash points of many silanes are less than 60°C, and the flash points of some silanes are even less than 28°C. The safety hazards and risks of raw materials during storage in the workshop are relatively large.

[0004] Based on the above status quo, curing-free water-based ceramic coatings need to be further improved. Summary of the Invention

[0005] In order to solve the above technical problems, the present application provides a curing-free water-based ceramic coating. After preparation, the water-based ceramic coating can be used immediately, does not require curing, and can be sprayed immediately. A ceramic coating can be obtained after high-temperature curing at 280°C for 15 minutes.

[0006] The present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 1:1 to 2:1, wherein:

[0007] The component A comprises silica sol and methyl hydrogen silicone oil, and the solid content of the component A is 20-40%;

[0008] The B component includes a silane coupling agent and a catalyst, and the effective content of the silane coupling agent is greater than 98%.

[0009] Optionally, the hydrogen content of the methyl hydrogen silicone oil is less than 3%, and the general structural formula of the methyl hydrogen silicone oil is:

[0010] m and n are positive integers.

[0011] Optionally, the catalyst is one of a metal salt catalyst, a platinum catalyst, and a palladium / carbon catalyst.

[0012] Optionally, the metal salt catalyst is one of cobalt chloride and molybdenum chloride.

[0013] Optionally, the weight ratio of the silane coupling agent to the catalyst in the component B is 99-100:0.1-0.2.

[0014] Optionally, the silane coupling agent is one of KH570 and KH172.

[0015] Optionally, the weight ratio of silica sol to methyl hydrogen silicone oil in component A is 40-92:5-10.

[0016] Optionally, the component A includes the following components in parts by weight:

[0017] 40-92 parts of silica sol;

[0018] 5-10 parts of methyl hydrogen silicone oil;

[0019] 0.1 to 20 parts of filler;

[0020] Pigment 0.1-29 parts;

[0021] 0.1-30 parts of pure water;

[0022] 0.1-5 parts of dispersant;

[0023] 0.1 to 5 parts of leveling agent.

[0024] Optionally, the silica sol is alkaline silica sol, and the particle size is between 20 and 60 nm.

[0025] Optionally, the dispersant is an aqueous dispersant.

[0026] Optionally, the particle size of the pigment and filler is less than 20 μm.

[0027] Optionally, the pigment includes one or more of titanium white, carbon black, copper chrome black, scarlet, iron red, iron yellow, phthalocyanine blue, phthalocyanine green, bismuth yellow, cobalt blue, cobalt green, pearlescent pigment, and metallic pigment, and the pigment particle size is less than 15 μm.

[0028] Optionally, the filler includes one or more of mica, titanium dioxide, fumed silica, silicon micropowder, alumina powder, barite, talc, and zirconium oxide, and the filler particle size is less than 20 μm.

[0029] The curing-free water-based ceramic coating of the present application saves a significant amount of curing time during use of existing coatings. After evenly mixing components A and B, the coating can be used immediately. Furthermore, the hardness, adhesion, temperature resistance, and non-stick properties of the ceramic coating formed after high-temperature curing are substantially consistent with those of existing ceramic coatings, and may even be superior to some existing ceramic coatings. DETAILED DESCRIPTION

[0030] Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of this application.

[0031] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 1:1 to 2:1, wherein:

[0032] Component A includes silica sol and methyl hydrogen silicone oil, and the solid content of component A is 20% to 40%;

[0033] Component B includes a silane coupling agent and a catalyst, and the effective content of the silane coupling agent is greater than 98%.

[0034] The silica sol herein is a dispersion of nano-sized silica particles in water. Acidic or alkaline silica sols with low impurity content can be prepared through existing chemical or physical synthesis methods. The solid content of component A refers to the amount of silica (solid) in the mixed solution after component A is mixed to form a mixed solution.

[0035] The catalyst of the present application is a catalyst or initiator that can initiate an addition reaction between Si-H bonds and unsaturated bonds. The methyl hydrogen silicone oil of the present application is an organosilicon compound containing silicon-hydrogen bonds, i.e., no double bonds.

[0036] When components A and B are mixed in a specific ratio, the silane coupling agent of component B is hydrolyzed in water to generate silanols. The methyl hydrogen silicone oil and the silane coupling agent undergo a silylation reaction under the action of a catalyst, which enhances the cross-linking effect between the molecules. At the same time, the nano-silica particles in the silica sol are dispersed in the silane coupling agent and the methyl hydrogen silicone oil. The silanol bonds and the nano-silica particles also undergo a certain degree of cross-linking reaction. When the silane coupling agent and the methyl hydrogen silicone oil are cross-linked and cured, the nano-silica particles are also wrapped and cured together, thereby forming a film containing silica sol, methyl hydrogen silicone oil, and organic silicon, that is, forming an organic-inorganic combined ceramic coating.

[0037] Thus, unlike existing ceramic coatings, the water-based ceramic coating of the present application does not require several hours of curing. Instead, a hydrosilylation reaction occurs only after the two components are mixed, resulting in a high degree of cross-linking and curing. Furthermore, after curing at a high temperature of 280°C for 15 minutes, the coating is fully cured into a ceramic coating with high hardness, good adhesion, high temperature resistance, scratch resistance, boiling resistance, good non-stickiness, and high food-grade contact safety.

[0038] Preferably, the silane coupling agent may be one of KH570 and KH172, wherein the structural formula of KH570 is:

[0039]

[0040] KH570 is hydrolyzed in water to form silanols. The reaction formula is as follows:

[0041]

[0042] Preferably, the methyl hydrogen silicone oil is a low hydrogen content hydrogen silicone oil, with a hydrogen content of less than 3% and greater than 1.55%. The general structural formula of the methyl hydrogen silicone oil is:

[0043] m and n are positive integers.

[0044] After components A and B are evenly mixed, methyl hydrogen silicone oil and KH570 undergo a hydrosilylation reaction under the action of a catalyst. The catalyst can be one of a metal salt catalyst, a platinum catalyst, and a palladium / carbon catalyst. The metal salt catalyst is preferably one of cobalt chloride and molybdenum chloride. The specific reaction formula is as follows:

[0045]

[0046] In the present application, KH570 is hydrolyzed in silica sol to generate silanol, and methyl hydrogen silicone oil undergoes a silylation reaction with KH570 under the action of a metal salt catalyst, i.e., the breaking of silicon-hydrogen bonds and the formation of silicon-carbon bonds, thereby enhancing the cross-linking effect between molecules and intensifying the polymerization effect between molecules.

[0047] At the same time, since the nano-silica particles in the silica sol are also evenly dispersed in KH570 and methyl hydrogen silicone oil, the nano-silica particles are also evenly wrapped therein during the silylation reaction, forming a structure in which the nano-silica is wrapped by a high molecular polymer, that is, forming an organic-inorganic combined silicon-containing coating.

[0048] In some embodiments, component B is prepared by mixing a silane coupling agent and a catalyst in a ratio of 99 to 100:0.1 to 0.2 and then dispersing the mixture. Preferably, the silane coupling agent and the catalyst are mixed in a ratio of 999:1 parts by weight.

[0049] Component A can adopt two formulations, wherein in some embodiments: Component A is prepared by dispersing silica sol and methyl hydrogen silicone oil in a ratio of 40-92:5-10 parts by weight, preferably silica sol and methyl hydrogen silicone oil in a ratio of 40:5 or 92:8 parts by weight.

[0050] In other embodiments, component A is prepared by mixing and dispersing the following components in parts by weight:

[0051] 40-92 parts (preferably 50-60 parts) of silica sol;

[0052] 5-10 parts (preferably 7-8 parts) of methyl hydrogen silicone oil;

[0053] 0.1 to 20 parts of filler (preferably 10 to 15 parts);

[0054] Pigment 0.1 to 29 parts (preferably 15 to 20 parts);

[0055] 0.1-30 parts (preferably 5-15 parts) of pure water;

[0056] 0.1 to 5 parts (preferably 1 to 3 parts) of dispersant;

[0057] 0.1 to 5 parts of leveling agent (preferably 1 to 3 parts).

[0058] Preferably, the silica sol is alkaline silica sol, and the particle size is between 20 and 60 nm.

[0059] The dispersant is a water-based dispersant, which not only has a wetting effect, but its active groups can be adsorbed on the surface of the pigment crushed into fine particles, so that the pigment, filler and other particles are dispersed and suspended, ensuring the stability of the coating system. Anionic, cationic or amphoteric wetting dispersants can be used.

[0060] The pigment includes one or more of titanium white, carbon black, copper chrome black, scarlet, iron red, iron yellow, phthalocyanine blue, phthalocyanine green, bismuth yellow, cobalt blue, cobalt green, pearlescent pigment, and metallic pigment, and the pigment particle size is less than 15 μm.

[0061] The filler includes one or more of mica, titanium dioxide, fumed silica, silicon micropowder, alumina powder, barite, talc, and zirconium oxide, and the filler particle size is less than 20 μm.

[0062] The introduction of fillers into ceramic coatings can significantly enhance the hardness of the coating, and the introduction of pigments facilitates color adjustment to obtain ceramic coatings of different colors. In this application, the pigments and fillers are fully ground to a fineness of less than 20 μm, and then combined with dispersants and leveling agents to ultimately obtain a ceramic coating with high film-forming quality.

[0063] Example 1

[0064] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 1:1, wherein (the following proportions are all by weight):

[0065] Component A includes 40 parts of silica sol and 5 parts of methyl hydrogen silicone oil, and the solid content of component A is 20%;

[0066] Component B includes 99.9 parts of KH570 and 0.1 parts of molybdenum chloride, and the effective content of KH570 is greater than 98%.

[0067] The prepared components A and B are mixed and dispersed evenly, filtered through a 300-mesh filter, and then directly sprayed and cured at 280°C to obtain a ceramic coating.

[0068] Example 2

[0069] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 2:1, wherein (the following proportions are all by weight):

[0070] Component A includes 92 parts of silica sol and 10 parts of methyl hydrogen silicone oil, and the solid content of component A is 40%;

[0071] Component B includes 100 parts of KH570 and 0.2 parts of molybdenum chloride, and the effective content of KH570 is greater than 98%.

[0072] The prepared components A and B are mixed and dispersed evenly, filtered through a 300-mesh filter, and then directly sprayed and cured at 280°C to obtain a ceramic coating.

[0073] Example 3

[0074] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 1.5:1, wherein (the following proportions are all by weight):

[0075] Component A includes 92 parts of silica sol and 8 parts of methyl hydrogen silicone oil, and the solid content of component A is 30%;

[0076] Component B includes 99.9 parts of KH570 and 0.1 parts of molybdenum chloride, and the effective content of KH570 is greater than 98%.

[0077] The prepared components A and B are mixed and dispersed evenly, filtered through a 300-mesh filter, and then directly sprayed and cured at 280°C to obtain a ceramic coating.

[0078] Example 4

[0079] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 1:1, wherein:

[0080] Component A is prepared by mixing and dispersing the following components in parts by weight:

[0081]

[0082] Component B is prepared by mixing a silane coupling agent and a catalyst in a ratio of 999:1 and then dispersing the mixture.

[0083] The prepared components A and B are mixed and dispersed evenly, filtered through a 300-mesh filter, and then directly sprayed and cured at 280°C to obtain a ceramic coating.

[0084] Example 5

[0085] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 1.5:1, wherein:

[0086] Component A is prepared by mixing and dispersing the following components in parts by weight:

[0087]

[0088]

[0089] Component B is prepared by mixing a silane coupling agent and a catalyst in a ratio of 999:1 and then dispersing the mixture.

[0090] The prepared components A and B are mixed and dispersed evenly, filtered through a 300-mesh filter, and then directly sprayed and cured at 280°C to obtain a ceramic coating.

[0091] Example 6

[0092] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 2:1, wherein:

[0093] Component A is prepared by mixing and dispersing the following components in parts by weight:

[0094]

[0095] Component B is prepared by mixing a silane coupling agent and a catalyst in a ratio of 999:1 and then dispersing the mixture.

[0096] The prepared components A and B are mixed and dispersed evenly, filtered through a 300-mesh filter, and then directly sprayed and cured at 280°C to obtain a ceramic coating.

[0097] Example 7

[0098] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 1:1, wherein:

[0099] Component A is prepared by mixing and dispersing the following components in parts by weight:

[0100]

[0101]

[0102] Component B is prepared by mixing a silane coupling agent and a catalyst in a ratio of 999:1 and then dispersing the mixture.

[0103] The prepared components A and B are mixed and dispersed evenly, filtered through a 300-mesh filter, and then directly sprayed and cured at 280°C to obtain a ceramic coating.

[0104] Example 8

[0105] One embodiment of the present application provides a curing-free water-based ceramic coating, which is prepared by mixing component A and component B in a mass ratio of 2:1, wherein:

[0106] Component A is prepared by mixing and dispersing the following components in parts by weight:

[0107]

[0108] Component B is prepared by mixing a silane coupling agent and a catalyst in a ratio of 999:1 and then dispersing the mixture.

[0109] The prepared components A and B are mixed and dispersed evenly, filtered through a 300-mesh filter, and then directly sprayed and cured at 280°C to obtain a ceramic coating.

[0110] Comparative Example 1

[0111] Common ceramic coatings on the market all require curing and cross-linking, and are composed of three components: A, B, and C, which are mixed in a mass ratio of 10:6:1.

[0112] Component A is prepared by mixing and dispersing the following components in parts by weight:

[0113]

[0114] Component B is prepared by mixing and dispersing the following components in parts by weight:

[0115]

[0116] Component C is prepared by mixing and dispersing the following components in parts by weight:

[0117] 70 parts of solvent;

[0118] 30 parts of leveling agent;

[0119] Mix the prepared components A and B in a mass ratio of 10:6, roll and mature them on a curing machine at high speed for 8 hours, then filter through a 300-mesh filter, add component C in a mass ratio of 1 / 16 of the AB mixture, disperse and mix evenly at high speed, and spray and cure to form a ceramic coating.

[0120] Performance Testing

[0121] The ceramic coatings of the above-mentioned embodiments and comparative examples were sprayed under the same conditions and cured at high temperature (280° C., 15 min) to obtain corresponding ceramic coatings. The hardness, adhesion, water boiling resistance, and non-stick properties of each ceramic coating were tested using the following test methods:

[0122] Coating hardness: scratched with pencils of different hardness, measured according to the method of GB / T1730-1993;

[0123] Adhesion: measured with a grid knife according to the method of GB / T9286-1998;

[0124] Boiling resistance: Boil in boiling water at about 100℃ for 4 hours, measured in accordance with GB / T5209-1985;

[0125] Fried eggs do not stick: The test refers to the test method of "4.2.1 in GB / T 32095.2-2015". The specific test method is:

[0126] Clean the frying pan with warm water above 60℃ and neutral detergent, then rinse it with clean water and wipe it dry; raise the temperature of the frying pan to 150-170℃, crack the shells of fresh eggs and put them into the frying pan, and after the protein is basically solidified, use a silicone spatula to remove the eggs intact.

[0127] For the evaluation method, see 5.1.1 of GB / T 32095.2-2015.

[0128]

[0129] Boil milk without sticking: Heat the coated pot, pour in 30ml of milk, boil the milk until it turns brown, then rinse with clean water. Without any other tools, the milk can be completely rinsed clean. Once the test is completed, continue with the second test, and repeat the test until the milk cannot be rinsed clean. The test is then completed.

[0130] The ceramic coatings prepared in Examples 3 to 6 and the ceramic coating prepared in Comparative Example 1 were subjected to the above-mentioned performance tests, and the recorded data are shown in Table 1.

[0131] Table 1

[0132]

[0133] It can be seen from this that before spraying, the ceramic coating of the present application saves a lot of aging time compared to existing coatings, and after spraying, the hardness, adhesion, water boiling resistance, non-stickiness and other properties exhibited by the ceramic coating of the present application are basically consistent with those of existing ceramic coatings, and the performance of some embodiments is even slightly better than that of existing ceramic coatings.

[0134] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present application, and such modifications and improvements are all within the scope of protection of the present application.

Claims

1. A curing-free water-based ceramic coating, characterized in that: It is prepared by mixing component A and component B in a mass ratio of 1:1 to 2:1, wherein: The component A includes silica sol and methyl hydrogen silicone oil, and the solid content of the component A is 20-40%; The B component includes a silane coupling agent and a catalyst; The hydrogen content of the methyl hydrogen silicone oil is less than 3%, and the general structural formula of the methyl hydrogen silicone oil is: , m and n are positive integers; The A component includes the following components by weight: 40-92 parts of silica sol; 5-10 parts of methyl hydrogen silicone oil; 0.1 to 20 parts of filler; Pigment 0.1-29 parts; 0.1-30 parts of pure water; 0.1-5 parts of dispersant; 0.1-5 parts of leveling agent; The weight ratio of the silane coupling agent to the catalyst in the B component is 99-100:0.1-0.2; The silane coupling agent is one of KH570 and KH172.

2. The water-based ceramic coating according to claim 1, characterized in that: The catalyst is one of a metal salt catalyst, a platinum catalyst and a palladium / carbon catalyst.

3. The water-based ceramic coating according to claim 2, characterized in that: The metal salt catalyst is one of cobalt chloride and molybdenum chloride.

4. The water-based ceramic coating according to claim 1, characterized in that: The silica sol is alkaline silica sol, and the particle size is between 20 and 60 nm.

5. The water-based ceramic coating according to claim 1, characterized in that: The particle size of the pigment and filler is less than 20 μm.

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