Ceramic non-stick coating with silicone oil slow-release effect and application thereof

Abstract

The present application relates to a ceramic non-stick coating with silicone oil slow-release effect, a preparation method and application thereof. The ceramic non-stick coating is prepared by the following method: A component: mixing silica sol, pigment sol, functional filler sol, whisker silicon, ceramic powder, mica powder, dispersing agent and water; B component: silane, silicone oil and catalyst, the catalyst is selected from one or more of formic acid, acetic acid and citric acid; C component: defoaming agent, leveling aid and isopropyl alcohol; mixing the above A, B and C components, stirring and curing for 4-6 hours, controlling the reaction at 40-50 DEG C, and obtaining the sprayable ceramic non-stick coating after reaction equilibrium. The present application uses a new functional filler sol which encapsulates emulsified silicone oil in porous particulate material to replace the traditional filler sol to prepare ceramic coating, and the prepared ceramic coating can be sprayed on the substrate by pneumatic spraying.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-stick ceramic coating, in particular to a ceramic non-stick coating with silicon oil slow-release effect, a preparation method and application thereof. BACKGROUND

[0002] Non-stick ceramic coating belongs to fine chemical products. This material can be coated on the surface of metal substrate by different construction processes to form a continuous coating layer with firm adhesion, certain strength and long-term non-stickiness. The most common application of non-stick ceramic coating is on aluminum substrate cookware. Non-stick ceramic coating is made of silica-based materials, which are abundant in nature and easy to obtain, and do not pollute the environment. Ceramic non-stick pots coated with non-stick ceramic coating are not easy to wear when used at high temperature, and their non-stickiness mainly comes from the silicon oil added in the coating. However, the silicon oil will slowly decompose and release at high temperature during use, resulting in a decrease in non-stick performance after a long time of use.

[0003] The silicon oil used in general ceramic cookware is dimethyl silicone oil or hydroxyl silicone oil. Dimethyl silicone oil does not have active reaction groups, so it cannot crosslink with silanol after silane hydrolysis, but only stays in the Si-O-Si bond of ceramic through physical adsorption. Due to the porous nature of ceramic, it is easy to decompose or extract under high temperature use or organic solvent soaking, and since it has no reactivity with silanol or silica, increasing the amount of addition will also cause the formation of floating oil on the surface during the drying process after spraying. Although hydroxyl silicone oil has certain reactivity, its compatibility is not guaranteed, and small molecular weight hydroxyl silicone oil is often used. The molecular weight is small, and the temperature resistance is not ideal. Long-term high-temperature use will still cause rapid decomposition and lead to a decrease in non-stick performance. SUMMARY

[0004] The purpose of the present application is to provide a ceramic non-stick coating with silicon oil slow-release effect. The ceramic non-stick coating is made of functional filler sol prepared by the method of the present application. The ceramic layer will slowly release silicon oil during use to maintain the non-stick performance of non-stick kitchenware or cookware, thereby improving the non-stick performance and long-term durability of kitchenware or cookware.

[0005] The technical solution adopted by the present application to solve its technical problems is as follows:

[0006] A functional filler sol is prepared by the following method:

[0007] S1, prepare emulsified silicon oil by mixing silicon oil, emulsifier, stabilizer and water. Add porous particulate material treated by vacuum degassing and dehydration to the emulsified silicon oil, and immerse the porous particulate material in the emulsified silicon oil for 1-10h. Take out the solid and dry to obtain emulsified silicon oil-porous particulate material;

[0008] S2. Emulsified silicone oil-porous granules and organosilane or silane coupling agent oligomers are mixed and dispersed at a weight ratio of 0.5 to 2:1 at high speed with a rotation speed of 1000 rpm to 2000 rpm and a dispersion time of 30 min to 50 min to obtain a mixture.

[0009] S3. Mix the mixture from S2 with silica sol at a weight ratio of 0.5 to 1:1, place it in a sealed bottle and disperse it at high speed at a speed of 1000 rpm to 2000 rpm for 30 min to 50 min. Filter to obtain the functionalized filler sol.

[0010] The preparation method of the functionalized filler sol of the present invention specifically includes the following three steps: S1, encapsulating hydrophilic emulsified silicone oil in the pores of porous particulate material; S2, treating the new material encapsulated with silicone oil with organosilane or silane coupling agent oligomer to improve the stability of silicone oil in porous material; S3, sol-gelling the material treated with organosilane or silane coupling agent oligomer to prepare a filler.

[0011] Emulsified silicone oil is the key source of the non-stick properties of ceramic cookware. This invention incorporates emulsified silicone oil into the pores of porous particulate materials. The emulsified silicone oil can be a high-molecular-weight, non-volatile silicone oil such as emulsified dimethyl silicone oil, or an easily emulsified silicone oil containing numerous hydrophilic groups. As an O / W emulsion, the water layer on the outer layer of the droplets ensures its reactivity within the ceramic material. This property guarantees the binding ability of the silicone oil in the ceramic. This binding effect is not permanent; it increases with use. As the silicone oil content outside the pores decreases, and the internal physicochemical adsorption force becomes less than the spontaneous diffusion effect of the silicone oil, a slow release of the silicone oil occurs, restoring the non-stick properties reduced by the external silicone oil. Using this invention increases the emulsified silicone oil content in the ceramic layer, ultimately improving the non-stick properties and long-term durability of the cookware.

[0012] Preferably, the vacuum degassing and dehydration treatment method for porous particulate materials involves placing the porous particulate material in a vacuum drying oven, venting the air from the oven, and maintaining this position for a period of time. This causes the air molecules originally retained in the pores of the porous particulate material to desorb. At this point, the vacuum pump is turned on again, and after a second venting, the position is maintained for a further period. The environment in the vacuum drying oven is 80–200℃, and the vacuum degree is -0.06 to -0.1. The duration of the first venting with the vacuum pump turned on is 5–30 minutes, followed by a holding time of 1–8 hours. The duration of the second venting with the vacuum pump turned on is 5–30 minutes, followed by a holding time of 1–8 hours.

[0013] Preferably, the organosilane or silane coupling agent oligomer is selected from one or more of methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane and their oligomers.

[0014] The weight ratio of emulsified silicone oil-porous granules to organosilanes or silane coupling agent oligomers is 1 to 2:1. Silane coupling agent oligomers are silane polymers synthesized by the condensation of methoxy groups in silanes after partial hydrolysis to hydroxyl groups.

[0015] As a preferred option, in S1,

[0016] The process of adding the porous particulate material to the emulsified silicone oil and immersing it is completed under vacuum conditions, and the weight ratio of the porous particulate material to the emulsified silicone oil is 1:0.1 to 10.

[0017] The immersion time is 10 min to 10 h, and the immersion temperature is maintained at 25 to 100 °C.

[0018] The drying process is carried out in a vacuum drying oven at 25–100°C, or naturally at 25–100°C, or by blowing at 25–100°C.

[0019] Preferably, the silicone oil is selected from one or more of dimethyl silicone oil, hydrogen-containing silicone oil, amino silicone oil, or hydroxyl silicone oil; the emulsifier is a nonionic emulsifier; and the porous particulate material is a porous oxide, selected from one or more of porous alumina, titanium dioxide, silicon dioxide, metal-organic framework materials, and covalent organic framework materials, preferably silicon dioxide. The porous particulate material can adsorb emulsified silicone oil through its pores, and its particle diameter is less than 25 μm.

[0020] Further preferred are dimethyl silicone oils with a molecular weight of 2000-6000, and hydrogen-containing silicone oils with a molecular weight of 1000-2000 and a hydrogen content of 0.1-0.3 wt%. More preferably, are dimethyl silicone oils with a molecular weight of 2000-2500.

[0021] Preferably, the silica sol is selected from alkaline silica sol.

[0022] As a preferred embodiment, the weight ratio of silicone oil, emulsifier, stabilizer and water in the emulsified silicone oil is as follows: the emulsified silicone oil is made by adding 5 parts of emulsifier to 50 parts of silicone oil, and then slowly adding it to a solution of 44 parts of water and 1 part of stabilizer.

[0023] Preferably, the weight ratio of the mixture of S3 to the silica sol is 0.5:1.

[0024] Preferably, in step S3, the filtration is performed using a 100-800 mesh filter.

[0025] A ceramic non-stick coating prepared using the functionalized filler sol described in this invention, wherein the ceramic non-stick coating is prepared by the following method:

[0026] Component A: A mixture of silica sol, pigment sol, functionalized filler sol, whisker silica, ceramic powder, mica powder, dispersant and water;

[0027] Component B: Silane, silicone oil and catalyst, wherein the catalyst is selected from one or more of formic acid, acetic acid and citric acid;

[0028] Component C: Defoamer, leveling agent, and isopropanol;

[0029] The above components A, B, and C are mixed in a mass ratio of 100:50-60:10-15 and stirred and matured at a speed of 1000-2000 rpm for 4-6 hours on a high-speed disperser. The reaction is controlled at 40-50℃. After the reaction reaches equilibrium, a sprayable ceramic non-stick coating is obtained.

[0030] As a preferred embodiment, the weight ratio of components A, B, and C is as follows:

[0031] Component A contains 30-40 parts silica sol, 30-40 parts pigment sol, 10-20 parts functionalized filler sol, 0-2 parts whisker silica, 0-5 parts ceramic powder, 1-3 parts mica powder, 0.1-1 parts dispersant, and 0-20 parts water.

[0032] Component B contains 80-95 parts of silane, 2-10 parts of silicone oil and 0.1-5 parts of catalyst. The silane is selected from one or more of methyltrimethoxysilane, methyltriethoxysilane and phenyltrimethylsilane. The silicone oil is one or two of dimethyl silicone oil and hydroxyl silicone oil. The catalyst is acetic acid.

[0033] Component C consists of 5-8 parts leveling agent, 0-2 parts defoamer, and 90-95 parts isopropanol.

[0034] A ceramic non-stick coating obtained by applying the ceramic non-stick coating described in this invention.

[0035] A method for applying the ceramic non-stick coating of the present invention comprises: spraying the ceramic non-stick coating to the kitchenware with a thickness of 30-40 μm using a pneumatic spraying method, and then baking it at 280℃±20℃ for 10min±10min to obtain the ceramic kitchenware.

[0036] An application of the ceramic non-stick coating of the present invention in the preparation of non-stick kitchenware, the kitchenware including frying pans, woks, saucepans, rice cookers, ovens, and range hoods.

[0037] The beneficial effects of this invention are:

[0038] This invention uses a novel functional filler sol that encapsulates emulsified silicone oil in a porous particulate material to replace traditional filler sols in ceramic coatings. The resulting ceramic coating can be applied to a substrate by pneumatic spraying and used in ceramic non-stick cookware or cookware.

[0039] The ceramic coating prepared by this invention uses a functionalized filler sol encapsulated with silicone oil. During use, the ceramic layer of the coated product will slowly release silicone oil to maintain the non-stick properties of non-stick cookware or cookware, thereby improving the non-stick properties and long-term durability of the cookware or cookware. Attached Figure Description

[0040] Figure 1 These are the FT-IR spectra of the filler sol prepared in Example 1 and the silica sol prepared in Comparative Example 1;

[0041] Figure 2 This is a schematic diagram of the principle of the present invention. a is a schematic diagram of the surface structure of porous silica, b is a schematic diagram of the surface structure of silica after vacuum degassing, and c is a schematic diagram of the structure of porous silica encapsulated with emulsified silicone oil. Detailed Implementation

[0042] The technical solution of the present invention will be further described in detail below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.

[0043] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0044] Unless otherwise specified, the reagents used in the following examples can be purchased from a regular biochemical reagent store. Porous silica, model SBA-15, was purchased from Sigma Reagents.

[0045] Silica sol, model LUDOX TMN, purchased from Sangchen Chemical (Shanghai) Co., Ltd.

[0046] Dimethyl silicone oil, model DC-92, Shanghai Liansheng Chemical Co., Ltd.;

[0047] Hydrogen-containing silicone oil, model KF-99, purchased from Dongguan Jianmeng Chemical Co., Ltd.

[0048] Hydroxysilicone oil, model JN-203, purchased from Shandong Juneng Chemical Co., Ltd.

[0049] Amino silicone oil, model Shin-Etsu KF-864, purchased from Dongguan Jianmeng Chemical Co., Ltd.

[0050] The structural formula of dimethyl silicone oil is CH3-(Si(CH3)2-O)n-CH3; the structure of amino silicone oil is obtained by replacing some of the methyl groups attached to Si with amino groups on the Si-O main chain of dimethyl silicone oil, thus obtaining greater hydrophilicity; hydroxyl silicone oil is obtained by replacing one end of the methyl group of dimethyl silicone oil with a hydroxyl group; hydrogen-containing silicone oil is obtained by replacing some of the methyl groups on the main chain of dimethyl silicone oil with hydrogen, thus reducing the total molecular weight.

[0051] To increase the amount of silicone oil that can be retained in ceramic coatings, the inventors prepared a functionalized filler sol by encapsulating emulsified silicone oil in porous particulate materials. Finally, they replaced part of the filler sol in the ceramic coating with this novel filler sol encapsulated with emulsified silicone oil. Encapsulating emulsified silicone oil in porous materials restricts its flowability during ceramic product preparation. By utilizing the pores of porous materials—where emulsified silicone oil is normally scarce in ceramic coatings—to retain it, the maximum amount of emulsified silicone oil that can be added to the ceramic coating can be significantly increased.

[0052] The inventors used various silicone oils with different molecular weights and containing different functional groups, emulsified the various silicone oils, and attempted to encapsulate them with porous materials. The encapsulated materials were then made into coatings that could be used directly.

[0053] A method for preparing the ceramic non-stick coating of the present invention comprises the following steps:

[0054] (1) Prepare the raw materials for emulsified silicone oil. Mix an appropriate amount of silicone oil with an emulsifier and add it to a beaker. Add a stabilizer to deionized water. Fix the beaker containing the silicone oil and emulsifier mixture onto an automatic stirrer and turn on the stirrer. Slowly add the weighed water containing the stabilizer to the beaker using a dropper. As water is added, the reactants in the beaker gradually become a paste. Continue to add the remaining water. After all the water has been added, continue stirring until the mixture is fully stirred. The desired emulsified silicone oil is then obtained and ready for use.

[0055] The emulsification process and formulation differ for different silicone oils. The formulation and reaction process must be adjusted according to the molecular weight of the silicone oil and the amount of hydrophilic groups it contains.

[0056] (2) Vacuum degassing and dehydration treatment of porous granular materials. Solid porous granular materials are placed in a glass dish and spread evenly. The glass dish is placed in a vacuum drying oven. The vacuum pump is turned on to remove the air in the oven. After a period of time, the air molecules and attached water contained in the pores of the porous granular materials are released, and the vacuum degree decreases. The vacuum pump is turned on again, and after a second exhaust, it is kept for a period of time for later use.

[0057] Porous particulate materials are porous oxide particles, such as porous alumina, titanium dioxide, and silicon dioxide, with silicon dioxide being the preferred material. Under the combined action of vacuum and high temperature, the original hydroxyl-containing surface of the oxide undergoes a dehydration reaction. This type of porous material without hydroxyl groups has extremely high surface energy and is highly sensitive to water molecules; upon contact with water molecules, it quickly recovers to its original state. Figure 2 This indicates the dehydration status of silica;

[0058] The temperature of the vacuum drying oven is 100℃. The vacuum degree needs to reach -0.085 each time the vacuum is evacuated. The vacuum needs to be maintained for 1 to 2 hours after the first and second evacuation.

[0059] (3) Encapsulate the emulsified silicone oil prepared in step (1) into the pores of the porous particulate material. After taking out the degassed porous particulate material prepared in step (2), immediately add an appropriate amount of the emulsified silicone oil prepared in step (1). The required emulsified silicone oil should be able to completely cover the porous particulate material layer. After keeping it for a period of time, take out the solids and dry them for later use. Alternatively, a remote control device can be placed in a vacuum drying oven, and the emulsified silicone oil can be added directly in a vacuum environment without taking out the porous particulate material.

[0060] In this step, the emulsified silicone oil penetrates into the pores and occupies the positions where air molecules were originally physically adsorbed. The water layer on the surface of the emulsified silicone oil can undergo a hydrolysis reaction with the oxygen on the surface of the porous material, occupying the positions where water molecules were originally chemically adsorbed, thus reducing the high surface energy after vacuum treatment.

[0061] (4) Pretreatment of the emulsified silicone oil-porous particulate material composite. Take the emulsified silicone oil-porous particulate material composite obtained in step (3) and add organosilane or silane coupling agent oligomer. Stir at 1500 rpm for 30 min on a high-speed disperser to complete the pretreatment of filling.

[0062] Porous materials encapsulated with emulsified silicone oil have poor stability, so this step is needed to perform limited polymerization of the particles. A small amount of silane or silane coupling agent oligomer can cause multiple porous material particles to agglomerate together under the connection of silane chains, and inhibit the precipitation of silicone oil through steric hindrance.

[0063] After encapsulation, the surface of the porous particulate material, except for the pores, will more or less adsorb some of the emulsified silicone oil, which weakens the hydrophilicity of the emulsified silicone oil-porous particulate material composite and makes it difficult to disperse directly in water. The silicone oil encapsulation in the pores of the emulsified silicone oil-porous particulate material composite may flow out during subsequent filling and coating processes. Pretreatment can seal the entrances of these small pores, allowing limited cross-linking of multiple porous oxide particles.

[0064] (5) Fill the pretreated emulsified silicone oil-porous particulate material composite. Take the emulsified silicone oil-porous particulate material composite prepared in step (4), mix it with silica sol in proportion, put it in a sealed bottle, seal it, fix the sealed bottle on a rapid disperser, shake and disperse continuously, take it out and filter it to obtain the prepared functionalized filler sol;

[0065] In step (4), the surface of the emulsified silicone oil-porous particulate material composite after pretreatment has cross-linked silane coupling agent oligomers. These unreacted silane coupling agent oligomers will continue to agglomerate over time, leading to uncontrolled cross-linking. Adding an excessive amount of ordinary silica sol causes the silane coupling agent oligomers on the surface to react with the silica particles in the silica sol, terminating the cross-linking process.

[0066] The rapid dispersion function disperses materials into a sol, with a shaking time of 1 to 10 hours.

[0067] (6) Take silica sol, functionalized filler sol, pigment sol, whisker silica, ceramic powder, mica powder, dispersant and deionized water and mix them as component A;

[0068] Take methyltrimethylsilane, methyltriethoxysilane, phenyltrimethylsilane, dimethyl silicone oil, hydroxy silicone oil, and acetic acid as a mixture as component B;

[0069] The foaming agent, leveling agent, and isopropanol are mixed as component C.

[0070] The above components A, B, and C are mixed in a mass ratio of 100:50-60:10-15 and stirred and matured at a speed of 1000-2000 rpm for 4-6 hours on a high-speed disperser. The reaction is controlled at 40-50℃. After the reaction reaches equilibrium, a sprayable ceramic non-stick coating is obtained.

[0071] This invention employs a vacuum degassing and re-adsorption method to load emulsified silicone oil into the pores of fine and porous particulate materials, and uses a rotational dispersion method to disperse the particles encapsulated with emulsified silicone oil in ordinary silica sol.

[0072] Because the coating contains functionalized filler sol, it can increase the total content of emulsified silicone oil in ceramic non-stick cookware. During high-temperature and frictional use, the emulsified silicone oil contained within is slowly released to replace the heat-damaged and volatilized emulsified silicone oil, thus improving the non-stick performance and long-term durability of the cookware. In this invention, the porous particulate material provides adsorption pores and a stable environment for the emulsified silicone oil, and when the emulsified silicone oil content outside the pores decreases due to use, it will spontaneously and slowly release the encapsulated emulsified silicone oil.

[0073] Example 1

[0074] A functionalized filler sol is prepared by the following method:

[0075] (1) Take 50 parts of dimethyl silicone oil with a molecular weight of 2000, 44 parts of deionized water, 5 parts of emulsifier and 1 part of stabilizer. Disperse the emulsifier into the dimethyl silicone oil and the stabilizer into the deionized water. During stirring, slowly add the deionized water containing the stabilizer to the dimethyl silicone oil containing the emulsifier. After complete addition, emulsified dimethyl silicone oil is obtained.

[0076] (2) Spread porous silica evenly in a glass dish, place it in a vacuum drying oven, and store it at 100°C and -0.085 vacuum for 2 hours. Then continue to exhaust the air until the vacuum recovers to below -0.085 and keep it for 1 hour.

[0077] (3) Pour the emulsified dimethyl silicone oil prepared in step (1) into the glass dish containing degassed porous silica in step (2). The amount of emulsified silicone oil should completely submerge the porous silica. After keeping it for 4 hours, filter out the solids and dry it for later use.

[0078] (4) Take 50 parts of porous silica containing emulsified dimethyl silicone oil prepared in step (3) and 50 parts of methyltrimethoxysilane, place them in a sealed bottle, and stir them at 1500 rpm for 30 minutes on a high-speed disperser to complete the pretreatment.

[0079] (5) Take 50 parts of the pretreated porous silica containing emulsified dimethyl silicone oil prepared in step (4), and 50 parts of ordinary silica sol. Place them in a sealed bottle and fix them on a high-speed disperser. Disperse them at a speed of 1000-2000 rpm for 30 minutes. After dispersing, take them out and filter them to obtain the functionalized filler sol.

[0080] Example 2

[0081] Same as Example 1, except that the molecular weight of the dimethyl silicone oil in step (1) is 6000.

[0082] Example 3

[0083] Same as Example 1, except that: hydrogen-containing silicone oil is used instead of dimethyl silicone oil in Example 1.

[0084] Example 4

[0085] Same as Example 1, except that the emulsified silicone oil formulation is 55 parts amino silicone oil, 39 parts deionized water, 5 parts emulsifier and 1 part stabilizer.

[0086] Example 5

[0087] Same as Example 1, except that the emulsified silicone oil formulation is 50 parts hydroxyl silicone oil, 44 parts deionized water, 5 parts emulsifier and 1 part stabilizer.

[0088] Example 6

[0089] Same as Example 1, except that in the fourth step, 50 parts of porous silica containing emulsified dimethyl silicone oil are encapsulated, and 25 parts of methyltrimethoxysilane are taken.

[0090] Example 7

[0091] Same as Example 1, except that in the fifth step, 50 parts of pretreated porous silica containing emulsified dimethyl silicone oil and 100 parts of ordinary silica sol are used.

[0092] Application examples

[0093] Preparation of ceramic coating: Take 30 parts of silica sol, 20 parts of functionalized filler sol, 30 parts of pigment sol, 10 parts of whisker silica, 3 parts of ceramic powder, 1 part of mica powder, 0.5 parts of dispersant, and 5.5 parts of deionized water and mix them as component A.

[0094] Take 39 parts of methyltrimethylsilane, 5 parts of methyltriethoxysilane, 3 parts of phenyltrimethylsilane, 1 part of dimethyl silicone oil, 1 part of hydroxy silicone oil, and 1 part of acetic acid and mix them as component B.

[0095] Remove 0.3 parts of foaming agent, 0.8 parts of leveling agent, and 8.9 parts of isopropanol and mix them as component C.

[0096] The above components A, B, and C are mixed in a mass ratio of 100:50:10 and stirred and matured at 1500 rpm for 4 hours on a high-speed disperser. The reaction temperature is controlled at 40-50℃. After the reaction reaches equilibrium, a sprayable ceramic non-stick coating is obtained.

[0097] The ceramic coatings prepared in Examples 1-7 were sprayed onto a frying pan with a thickness of 30-40 μm using a pneumatic spraying method. The pans were then baked at 280°C for 10 min to obtain ceramic non-stick frying pan samples, which were then used for subsequent tests.

[0098] Comparative Example 1

[0099] Take 25 parts of untreated porous silica and mix it with 25 parts of methyltrimethoxysilane in a high-speed disperser. Then take 50 parts of silica sol, grind it by shaking for 4 hours, and filter it through a 400-mesh filter to obtain the filler sol for comparison.

[0100] Ceramic coatings were prepared using the same formulation and process as in Examples 1-5, and then coated onto ceramic non-stick pans.

[0101] Application examples

[0102] I. Fourier Transform Infrared Spectroscopy (FT-IR) Analysis

[0103] Fourier transform infrared spectroscopy analysis was performed on the two groups of filler sol samples prepared in the examples and comparative examples. Since the samples in the examples were encapsulated with emulsified dimethyl silicone oil during the preparation process, characteristic peaks of organic groups such as methyl groups were observed in the infrared spectrum. This method can be used to prove the feasibility of encapsulating emulsified silicone oil in porous silica using this method.

[0104] As attached Figure 1 As shown, the black spectrum is the FT-IR spectrum of porous silica encapsulated with emulsified dimethyl silicone oil in Example 1, and the rest are FT-IR spectra of common silica sols. It can be seen that the functionalized filler sol in this invention has obvious methyl absorption peaks, proving that the scheme of this invention has achieved the expected goal, and emulsified dimethyl silicone oil has been incorporated into the pores of the filler.

[0105] II. After the ceramic cookware products are manufactured, non-stick properties and long-term durability are tested.

[0106] 1. High-temperature non-stick test

[0107] Place the frying pan in a preheated oven at 300℃ and let it sit for 1 hour, then allow it to cool slowly at room temperature. After cleaning, perform an egg non-stick test to evaluate the non-stick properties. A non-stick performance of level 2 or higher is considered a completed cycle. Repeat the test until the non-stick performance can no longer reach level 2, then end the test and record the number of cycles.

[0108] 2. Saltwater resistance and non-stick performance test

[0109] Fill a frying pan with 5% salt water, heat the salt water to 90-100℃ and keep it warm for 2 hours. After cleaning, perform an egg non-stick test to evaluate the non-stick properties. A non-stick performance of level 2 or higher is considered a completed cycle. Repeat the test until the non-stick performance can no longer reach level 2. Then, end the test and record the number of cycles.

[0110] 3. Milk non-stickiness test

[0111] A continuous milk boiling test was conducted on the sample. The sample was washed with warm water containing neutral detergent at 55℃-65℃, dried, and 12-20ml of pure milk was added to the sample. The sample was placed on a gas stove and the milk was boiled over low heat until it turned black (maximum temperature 230-250℃). The sample was then rinsed with tap water. If the milk could be completely or mostly washed off, and a small portion could be wiped off with a cloth, this constituted one cycle. The operation was repeated until the milk could no longer be washed off with tap water after boiling the same area. The number of times the milk was boiled was recorded.

[0112] 4. Saltwater durability test

[0113] Fill the sample with 10% sodium chloride saline solution, which is 2 / 3 of the total volume. Heat the saline solution to a slight boil and keep it warm for 7 hours. Add water every half hour to maintain the concentration. After completion, stop heating and let the sample soak in the saline solution for 16 hours. After completion, pour out the saline solution and observe whether there is bubbling or coating peeling. If no bubbling or coating peeling occurs after two consecutive cycles, it is considered qualified.

[0114] 5. Dishwasher durability test

[0115] Add 30g of Finish detergent and 40g of Finish powder to the dishwasher's compartment. Arrange the sample on the dishwasher rack, close the door, and set the dishwasher temperature to 70℃ for 120 minutes as one cycle. After starting the dishwasher, wait for it to complete one wash cycle. Remove the sample and observe for any bubbling or coating peeling. If no abnormalities are found, repeat the test and record the number of cycles.

[0116] III. Egg Non-stickiness Test

[0117] The test method is 4.2.1 of GB / T 32095.2-2015. The specific test method is as follows:

[0118] Clean the frying pan with warm water above 60℃ and add neutral detergent, then rinse it with clean water and dry it. Heat the frying pan to 150-170℃, crack the fresh egg and put it into the frying pan. After the protein has basically solidified, use a silicone spatula to remove the egg completely. See Table 1 for the specific non-stick test evaluation level of the egg.

[0119] Table 1 Evaluation Standards for Egg Non-stick Test Performance

[0120]

[0121]

[0122] IV. Stability Testing of Functionalized Filler Sol

[0123] The testing methods were the static settling method and the centrifugation method. 30 ml of the prepared functionalized filler sol was added to a centrifuge tube and allowed to stand vertically for 24 hours; no silicone oil precipitated on the upper layer of the liquid. The centrifuge tube was then placed in a centrifuge and centrifuged continuously at 8000 rpm for 5 minutes. After removal and standing for 3 minutes, a white precipitate was observed at the bottom of the centrifuge tube, and no silicone oil precipitated on the upper layer.

[0124] V. Adhesion and Water Adhesion Test

[0125] The samples were marked with a 100-grid pattern according to GB / T 9286-2021, with a grid spacing of 2 mm for inorganic coatings. For adhesion testing, 3M-898 tape was applied to the marked areas. The tape was then rubbed vigorously with a fingertip or the end of a pencil to remove air bubbles. One end of the tape was then pulled at a 90° angle and peeled off, five times horizontally and five times vertically, using fresh tape each time. The degree of peeling was observed. For water adhesion testing, the marked samples were boiled in tap water for 30 minutes. After removal, the procedure was the same as for general adhesion testing, and the degree of peeling was observed. Adhesion ratings are related to peeling, as shown in Table 2.

[0126] Table 2 Adhesion Evaluation Criteria

[0127]

[0128] Table 3. Test data for the frying pans prepared in the examples and comparative examples.

[0129]

[0130] The examples in Table 3 replace the solid porous silica in the comparative ceramic coatings with porous silica encapsulated with emulsified silicone oil. The various non-stick and durability tests essentially involve consuming the silicone oil content in the ceramic coating through various methods, thus reducing its non-stick properties. Based on the data from the examples and comparative examples, the scheme of encapsulating emulsified silicone oil with porous silica and preparing it as a filler sol applicable to ceramic coatings is feasible. The ceramic layer prepared using this filler exhibits good adhesion and can form a continuous ceramic structure on the substrate. In multiple durability and non-stick tests, Examples 1-7, which used filler sols, showed significant improvements in non-stick performance compared to Comparative Example 1, indicating that the novel method of introducing silicone oil by encapsulating emulsified silicone oil in the filler is applicable to various silicone oils. Comparing Examples 1-7, dimethyl silicone oil showed the best non-stick performance. The dimethyl silicone oil in Example 2 had a larger molecular weight, making encapsulation more difficult than in Example 1, resulting in a lower encapsulation amount in the filler and a slight decrease in performance compared to Example 1. In Example 6, the amount of methyltrimethoxysilane was reduced, resulting in a less tight encapsulation than in Example 1. This could lead to silicone oil loss during subsequent filler sol-gelation and curing processes, reducing performance. In Example 7, the amount of silica sol used in the filler process of the encapsulated porous silica was increased. This resulted in better sol-gelation, better filler dispersion, and reduced agglomeration and sedimentation. However, the reduced filler amount naturally decreased the amount of silicone oil in the final ceramic coating, leading to a slight decrease in performance.

[0131] Appendix Figure 2This is a schematic diagram illustrating the surface structure changes of the porous silica used in this invention. On the untreated porous silica surface, oxygen atoms in contact with air spontaneously react with water to generate silanol groups, such as... Figure 2 a; After high-temperature vacuum degassing, the surface hydroxyl groups undergo dehydration and transform into Si-O-Si bonds, such as Figure 2 b; When emulsified dimethyl silicone oil is added to porous silica without surface hydroxyl groups, water molecules on the surface of the emulsified dimethyl silicone oil react with the Si-O-Si bonds on the surface of the porous silica to generate silanol groups. These silanol groups can bind to the water layer on the surface of the emulsified silicone oil through hydrogen bonds, and the internal silicone oil layer is fixed inside the silica and water layers, such as... Figure 2 c.

[0132] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0133] The foregoing has provided a detailed description of a ceramic non-stick coating with a silicone oil slow-release effect and its applications. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely illustrative of the method and core ideas of the invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A functionalized filler sol, characterized in that The functional filler sol is prepared by the following method: S1, prepare emulsified silicone oil by mixing silicone oil, emulsifier, stabilizer and water, add porous granular material treated by vacuum degassing and dehydration to the emulsified silicone oil, and immerse the porous granular material in the emulsified silicone oil for 1-10 h, take out the solid, dry, and obtain emulsified silicone oil-porous granular material; The vacuum degassing and dehydration treatment method is to place the porous granular material in a vacuum drying box, exhaust the air in the box, and keep for a period of time, so that the air molecules originally retained in the pores of the porous granular material are desorbed, at this time, the vacuum pump is opened again, and after secondary exhaust, keep for a period of time; S2, mix the emulsified silicone oil-porous granular material and organosilane or silane coupling agent oligomer at a weight ratio of 1-2:1, high-speed dispersion, rotation speed is 1000 rpm-2000 rpm, dispersion time is 30 min-50 min, and obtain the mixture; S3, mix the mixture of S2 and silica sol at a weight ratio of 0.5-1:1, seal in a bottle, high-speed dispersion, rotation speed is 1000 rpm-2000 rpm, dispersion time is 30 min-50 min, filtration, and obtain the functional filler sol; The organosilane or silane coupling agent oligomer is selected from one or more of methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane and oligomers thereof; In S1, The process of adding the porous granular material to the emulsified silicone oil and immersion is completed under vacuum condition, and the weight ratio of the porous granular material to the emulsified silicone oil is 1:0.1-10; The immersion time is 10 min-10 h, and the immersion temperature is kept at 25-100℃; The drying is carried out at 25-100℃ in a vacuum drying box, or natural drying at 25-100℃, or blowing drying at 25-100℃.

2. The functional filler sol according to claim 1, characterized in that: The silicone oil is selected from one or more of dimethyl silicone oil, hydrogen-containing silicone oil, amino silicone oil or hydroxyl silicone oil; The emulsifier is a non-ionic emulsifier; The porous granular material is a porous oxide selected from one or more of porous alumina, titanium dioxide, silicon dioxide, metal organic framework material and covalent organic framework material; The silica sol is selected from alkaline silica sol.

3. The functionalized filler sol of claim 1, wherein: In S3, the filtration is carried out through a 100-800 mesh filter screen.

4. A ceramic non-stick coating prepared using the functionalized filler sol of claim 1, characterized by The ceramic non-stick coating is prepared by the following method: A component: mix silica sol, pigment sol, functional filler sol, whisker silicon, ceramic powder, mica powder, dispersant and water to obtain; B component: weight ratio of B component: silane, silicone oil and catalyst, the catalyst is selected from one or more of formic acid, acetic acid and citric acid; C component: defoaming agent, leveling aid and isopropyl alcohol; Mix the above A, B and C components at a mass ratio of 100:50-60:10-15, stir and mature on a high-speed dispersion machine at a rotation speed of 1000 rpm-2000 rpm for 4-6 h, and control the reaction at 40-50℃, and obtain the sprayable ceramic non-stick coating after reaction equilibrium.

5. The ceramic non-stick coating according to claim 4, characterized in that The weight ratio of A, B and C components is: A component contains 30-40 parts of silica sol, 30-40 parts of pigment sol, 10-20 parts of functional filler sol, 0-2 parts of whisker silicon, 0-5 parts of ceramic powder, 1-3 parts of mica powder, 0.1-1 parts of dispersing agent, and 0-20 parts of water; B component contains 80-95 parts of silane, 2-10 parts of silicone oil and 0.1-5 parts of catalyst, the silane is selected from one or more of methyltrimethoxysilane, methyltriethoxysilane and phenyltrimethylsilane, the silicone oil is one or both of dimethyl silicone oil and hydroxyl silicone oil, and the catalyst is acetic acid; C component is composed of 5-8 parts of leveling agent, 0-2 parts of defoaming agent, and 90-95 parts of isopropyl alcohol.

6. A ceramic non-stick coating prepared by coating the ceramic non-stick coating of claim 4.

7. A method of applying the ceramic non-stick coating of claim 4, characterized in that The method is: The ceramic non-stick coating is sprayed onto the kitchen utensil in a thickness of 30-40 μm by pneumatic spraying, and then baked at 280℃±20℃ for 10min±10min to obtain the ceramic kitchen utensil.

8. Use of the ceramic non-stick coating of claim 4 in the preparation of non-stick kitchen utensils, including frying pans, woks, soup pots, rice cookers, ovens and smoke machines.

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