Catalytic coating material, preparation method of adhesive, catalytic coating and cooking utensil

Abstract

The invention discloses a catalytic coating material, a preparation method of an adhesive, a catalytic coating and a cooking utensil, and belongs to the field of coating materials of cooking utensils. The preparation method comprises the following steps: mixing hydroxyl-terminated silicone oil, a silane coupling agent, silicate ester, a cosolvent, a pH regulator and water to obtain a mixed solution; and heating the mixed solution to obtain the adhesive provided by the invention. According to the catalytic coating prepared from the adhesive, a catalyst can be firmly loaded on a base material, is not easy to fall off and is fully exposed in air, and the catalytic coating has relatively strong degradation and cleaning capability on oil fume / grease pollutants, so that cooking utensils are relatively easy to clean, and meanwhile, the catalytic coating has relatively long service life; the catalytic coating has high temperature resistance due to the unique structure of the adhesive, can resist the high temperature of 300 DEG C or above, is not prone to powder falling due to long-term high-temperature environment, and is good in durability.

Description

Technical Field

[0001] The invention relates to the field of coating materials for cooking utensils, and in particular to a preparation method of a catalytic coating material and an adhesive, a catalytic coating and a cooking utensil. Background Art

[0002] Nowadays, many cooking utensils have cleaning problems. For example, when an air fryer is baking food in a cycle, the grease generated by the food itself or the grease smeared on the food or the oil fume formed by the hot air circulates in the air fryer. Meat food, in particular, has a high oil content. The oil fume easily accumulates on the fan blades and the reflector covers around the fan blades. The fan blades and the reflector covers are not easy to disassemble, thus creating cleaning dead corners that breed bacteria and produce odors.

[0003] At present, there is a new type of thermal catalytic functional coating material, which is usually composed of a catalyst and an adhesive. The heat generated by the heating module of the cooking utensils during the cooking process is used to directly catalyze and oxidize the grease splashed onto the surface of the heating module to avoid the accumulation of grease. However, since such cooking utensils with heating modules that are easily contaminated by grease are usually in a high-temperature working environment when in use, the adhesive needs to be resistant to high temperatures above 300°C. Most organic adhesives on the market will degrade at 300°C, while inorganic adhesives have poor toughness and are prone to powdering, which poses a safety hazard when used. In addition, inorganic adhesives have low bonding efficiency and often require more adhesives, which will cover the catalyst and reduce the catalytic efficiency. Summary of the invention

[0004] The present invention provides an adhesive and a preparation method thereof, a catalytic coating material, a catalytic coating and a cooking utensil, which solve the technical problem that the adhesive in the thermal catalytic functional coating of the cooking utensil cannot take into account the high temperature resistance, toughness, bonding efficiency and catalytic efficiency.

[0005] To achieve the above objectives, the present invention provides a catalytic coating material for cooking utensils in a first aspect. The catalytic coating material comprises an adhesive and a catalyst.

[0006] In some embodiments of the present invention, the adhesive has the following structural formula:

[0007]

[0008] Wherein, n is greater than or equal to 1.

[0009] In some embodiments of the present invention, calculated by weight percentage, the content of the adhesive in the catalytic coating material is 20%-40%; and / or the content of the catalyst in the catalytic coating material is 20%-40%.

[0010] In some embodiments of the present invention, the catalytic coating material further comprises water and / or a loading.

[0011] In some embodiments of the present invention, the catalyst is a metal oxide catalyst.

[0012] In some embodiments of the present invention, the particle size range of the catalyst is 5 μm - 10 μm.

[0013] In some embodiments of the present invention, the solid content of the binder is 32% - 60%.

[0014] In some embodiments of the present invention, the solid content of the binder is 45% - 55%.

[0015] In some embodiments of the present invention, the particle size of the binder is 100 - 200 nm.

[0016] The second aspect of the present invention provides a method for preparing a binder, comprising the following steps:

[0017] Mix hydroxyl-terminated silicone oil, a silane coupling agent, a silicate ester, a co-solvent, a pH regulator, and water to obtain a mixed solution;

[0018] Heat the mixed solution to obtain the binder.

[0019] In some embodiments of the present invention, the silicate ester includes at least one of tetraethyl orthosilicate and tetramethoxysilane.

[0020] In some embodiments of the present invention, the silane coupling agent includes at least one of γ-glycidoxypropyltrimethoxysilane (KH560), γ-aminopropyltrimethoxysilane (KH550), γ-methacryloxypropyltrimethoxysilane (KH570), (3,3,3-trifluoropropyl)trimethoxysilane, and methyltrimethoxysilane.

[0021] In some embodiments of the present invention, the pH of the mixed solution is 1 - 5.

[0022] In some embodiments of the present invention, the viscosity of the hydroxyl-terminated silicone oil is 100 cP - 500 cP.

[0023] In some embodiments of the present invention, the weight ratio of the hydroxyl-terminated silicone oil, the silane coupling agent, the silicate ester, the co-solvent, the pH regulator, and water is: (1 - 5) : (1 - 5) : (30 - 50) : (40 - 70) : (1 - 3) : (5 - 10).

[0024] In some embodiments of the present invention, the temperature for heating the mixed solution is 60°C - 80°C; and / or, the heating time of the mixed solution is 2 h - 5 h.

[0025] The third aspect of the present invention provides a catalytic coating applied to a cooking appliance, and the catalytic coating is prepared from the catalytic coating material as described above.

[0026] In some embodiments of the present invention, part of the catalyst is exposed to the air.

[0027] In some embodiments of the present invention, the roughness of the catalytic coating is 140 μm - 370 μm.

[0028] In some embodiments of the present invention, clusters composed of the catalyst with a height of 0.1 μm to 150 μm and a diameter of 0.1 μm to 500 μm are randomly distributed on the surface of the catalytic coating.

[0029] In some embodiments of the present invention, slit bands composed of the catalyst with a width of 1 μm to 10 μm and a depth of 1 μm to 100 μm are randomly distributed on the surface of the catalytic coating.

[0030] In some embodiments of the present invention, the oil contact angle of the catalytic coating is less than or equal to 5°.

[0031] In some embodiments of the present invention, the water contact angle of the catalytic coating is greater than or equal to 120°.

[0032] The fourth aspect of the present invention provides a cooking appliance, and the cooking appliance includes the catalytic coating according to any one of claims 78 to 23.

[0033] In some embodiments of the present invention, the catalytic coating is coated on the surface of the heating module of the cooking appliance and / or any inner surface of the cooking cavity.

[0034] In some embodiments of the present invention, the cooking appliance includes an air fryer, an electric pressure cooker, a griddle, an automatic cooking machine or an electric griddle.

[0035] In some embodiments of the present invention, the cooking appliance is an air fryer, and the catalytic coating is coated on the heating component of the air fryer.

[0036] The beneficial effects that the present invention can achieve:

[0037] The adhesive provided by the present invention can be used to prepare a catalytic coating material applied to a cooking appliance, and a catalytic coating is formed from the catalytic coating material.

[0038] The adhesive of the present invention has the high-temperature resistance of an inorganic adhesive and is not easily decomposed under high-temperature conditions above 300°C. It also has the toughness of an organic adhesive, high bonding efficiency, and is used to prepare the catalytic coating of cooking utensils. With a small amount of addition, it has good adhesion, can firmly fix the catalyst on the surface of the catalytic coating without completely covering the catalyst, and can meet the requirements of fully exposing the catalyst in the catalytic coating to the air and the catalytic coating not being prone to powder shedding.

[0039] The catalytic coating prepared from the above adhesive can firmly fix the catalyst on the substrate, is not easily dropped and is fully exposed to the air, has a strong degradation and cleaning ability for oil fume / grease pollutants, can greatly exert the catalytic oxidation effect of the catalyst, degrade the oil fume into water and carbon dioxide, make the cooking utensils easier to clean, and has a long service life. In addition, the catalytic coating of the present invention has high-temperature resistance due to the unique structure of the adhesive, can withstand high temperatures above 300°C, and is not prone to powder shedding due to long-term exposure to high-temperature environments, and has good durability.

[0040] Since the composition contains silicon with low surface energy, the adhesive of the present invention has good lipophilic and hydrophobic properties. When used to prepare the catalytic coating, it can combine with the catalyst to produce micro-nano cluster and slit-zone morphologies. The catalytic coating has an oil contact angle less than or equal to 5°, and catalyst clusters with a height of 0.1 μm to 150 μm and a diameter of 0.1 μm to 500 μm and catalyst slit zones with a width of 1 μm to 10 μm and a depth of 1 μm to 100 μm are randomly distributed on the surface. Specifically, catalyst clusters and slit zones are formed on the surface of the catalytic coating, so that the oil fume / grease pollutants are fully exposed and temporarily stored on the inner surface of the tiny slits on the surface of the catalytic coating. While the formation of the cluster and slit structure can increase the contact area with the catalyst, the pollutant molecules are "caught" by the surface slits of the catalytic coating for full reaction, further improving the catalytic effect and accelerating the oxidative degradation of the oil fume / grease pollutants; in addition, catalyst clusters at the millimeter, micron, and nanometer levels are interpenetrated on the surface of the catalytic coating, enhancing the mechanical stability of the catalytic coating; the catalytic coating has a water contact angle greater than or equal to 120°, avoiding the competitive adsorption of water vapor and grease on the surface of the catalytic coating, and also increasing the water resistance of the coating. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0042] Figure 1Schematic diagram of the preparation process of an adhesive of the present invention;

[0043] Figure 2 Surface morphology of the catalyst coating of the present invention.

[0044] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0045] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0047] In the present invention, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0048] The present invention provides a catalytic coating material for cooking utensils. The catalytic coating material includes an adhesive and a catalyst. The catalytic coating material can be coated on the inner surface of the cooking utensil that is prone to be contaminated by oil fume / grease pollutants to form a catalytic coating. The catalyst is fixed on the surface of the catalytic coating through the adhesive, and the catalyst is fully exposed to the air and directly contacts the oil fume / grease pollutants, so as to achieve the purpose of quickly catalytically degrading the oil fume / grease pollutants.

[0049] In some embodiments, the adhesive has the following structural formula:

[0050]

[0051] Wherein, n is greater than or equal to 1.

[0052] In this embodiment, the adhesive has the high-temperature resistance of an inorganic adhesive and is not easily decomposed under high-temperature conditions above 300°C. It also has the toughness of an organic adhesive, high bonding efficiency, and is used to prepare the catalytic coating of a cooking appliance. With a small amount of addition, it has good adhesion, can firmly fix the catalyst on the surface of the catalytic coating without completely covering the catalyst, and can meet the requirements of fully exposing the catalyst in the catalytic coating to the air and the catalytic coating not being prone to powder falling.

[0053] The catalytic coating prepared from the adhesive of this embodiment can firmly fix the catalyst on the substrate, is not easily dropped and is fully exposed to the air, has a strong degradation and cleaning ability for oil fume / grease pollutants, can greatly exert the catalytic oxidation effect of the catalyst, degrade the oil fume into water and carbon dioxide, make the cooking appliance easier to clean, and has a long service life. In addition, the catalytic coating of the present invention has high-temperature resistance due to the unique structure of the adhesive, can withstand high temperatures above 300°C, and is not prone to powder falling due to being in a high-temperature environment for a long time, and has good durability.

[0054] In this embodiment, since the above-mentioned adhesive composition contains silicon with low surface energy, it has good lipophilic and hydrophobic properties. When used to prepare the catalytic coating, it can combine with the catalyst to generate micro-nano cluster and slit band morphologies. Referring to Figure 2 , the catalytic coating has an oil contact angle less than or equal to 5°. As shown in Figure 2 , catalyst clusters with a height of 0.1 μm to 150 μm and a diameter of 0.1 μm to 500 μm, and catalyst slit bands with a width of 1 μm to 10 μm and a depth of 1 μm to 100 μm are randomly distributed on the surface. Specifically, catalyst clusters and slit bands are formed on the surface of the catalytic coating, so that the oil fume / grease pollutants are fully exposed and temporarily stored on the inner surface of the tiny slits on the surface of the catalytic coating. While the formation of the cluster and slit structure can increase the contact area with the catalyst, the pollutant molecules are "caught" by the surface slits of the catalytic coating for full reaction, further improving the catalytic effect and accelerating the oxidative degradation of the oil fume / grease pollutants; in addition, catalyst clusters at the millimeter, micron, and nanometer levels are interpenetrated on the surface of the catalytic coating, enhancing the mechanical stability of the catalytic coating; the catalytic coating has a water contact angle greater than or equal to 120°.

[0055] In some embodiments, calculated by weight percentage, the content of the binder in the catalytic coating material is 20%-40%. For example, the content of the binder can be any content value in the range of 20%-40% such as 20%, 23%, 25%, 27%, 28%, 29%, 30%, 32%, 35%, 38%, 39%, 40%, etc. Since the binder of the present invention has a strong adhesive force, only a small amount needs to be added to the catalytic coating material, and the catalyst can be firmly fixed on the surface of the catalytic coating when preparing the catalytic coating. Moreover, because the proportion of the binder in the catalytic coating is small, the content of the catalyst in the coating can be increased, and the catalyst will not be completely coated, so that it is fully exposed to the air and directly contacts with the oil fume / grease pollutants splashed on the surface of the catalytic coating, achieving the purpose of rapidly oxidizing and degrading the oil fume / grease pollutants.

[0056] In some embodiments, the content of the catalyst in the catalytic coating material is 20%-40%. For example, the content of the catalyst can be any content value in the range of 20%-40% such as 20%, 23%, 25%, 27%, 28%, 29%, 30%, 32%, 35%, 38%, 39%, 40%, etc. In this embodiment, the catalyst content is relatively high, which can help the catalytic coating achieve a strong oil pollution catalytic oxidation and degradation effect, and will not agglomerate due to excessive catalyst content, resulting in uneven catalytic effect of the catalytic coating or powder falling off of the catalytic coating.

[0057] In some embodiments, the content of the binder in the catalytic coating material is 20%-40%, and the content of the catalyst is 20%-40%. For example, the content of the binder can be any content value in the range of 20%-40% such as 20%, 23%, 25%, 27%, 28%, 29%, 30%, 32%, 35%, 38%, 39%, 40%, etc., and the content of the catalyst can be any content value in the range of 20%-40% such as 20%, 23%, 25%, 27%, 28%, 29%, 30%, 32%, 35%, 38%, 39%, 40%, etc.

[0058] In some embodiments, the catalyst is a metal oxide catalyst, and the surface of the metal oxide has more catalytic active sites. Under the condition of high temperature and oxygen, the oil fume / grease pollutants can be catalytically oxidized and degraded into carbon dioxide and water.

[0059] In some embodiments, the particle size of the catalyst ranges from 5 μm to 10 μm. For example, the particle size of the catalyst can be any one of the particle size values in the range of 5 μm to 10 μm, such as 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, etc. With the above particle size range, the catalyst is more easily adsorbed by the binder of the present invention and fixed on the surface of the catalytic coating, and is not easily completely wrapped by the organic-inorganic catalyst, and can be fully exposed to the air, directly contacting with oil fume / grease pollutants, so as to achieve the purpose of rapidly oxidizing and degrading oil fume / grease pollutants.

[0060] In some embodiments, the solid content of the binder of the present invention is 32% - 60%. For example, the solid content can be any one of the content values in the range of 32% - 60%, such as 32%, 35%, 38%, 39%, 40%, 43%, 45%, 47%, 48%, 49%, 50%, 52%, 55%, 57%, 58%, 59%, 60%, etc. Under the above solid content conditions, the binder has good viscosity.

[0061] In some embodiments, the catalytic coating material further contains water, which can promote the uniform mixing of the binder and the catalyst, and is more conducive to the preparation of the catalytic coating on the inner surface of the cooking appliance.

[0062] In some embodiments, calculated by weight percentage, the water content in the catalytic coating material can be 20% - 60%. For example, the water content can be any one of the content values in the range of 20% - 60%, such as 20%, 30%, 40%, 50%, 60%, etc. Under the above weight percentage conditions, water can uniformly mix the binder and the catalyst, facilitating the preparation of a uniform and structurally stable catalytic coating.

[0063] In some embodiments, calculated by weight percentage, the catalytic coating material contains 20% - 40% of the binder, 20% - 40% of the catalyst, and 20% - 60% of water. For example, calculated by weight percentage, the content of the binder in the catalytic coating material is any one of the content values in the range of 20% - 40%, such as 20%, 23%, 25%, 27%, 28%, 29%, 30%, 32%, 35%, 38%, 39%, 40%, etc., the content of the catalyst is any one of the content values in the range of 20% - 40%, such as 20%, 23%, 25%, 27%, 28%, 29%, 30%, 32%, 35%, 38%, 39%, 40%, etc., and the water content is any one of the content values in the range of 20% - 60%, such as 20%, 30%, 40%, 50%, 60%, etc.

[0064] In some embodiments, the catalytic coating material further includes a carrier, and the carrier includes γ - Al 2 O 3 、SiO 2, TiO 2 , ZrO 2 , at least one of molecular sieves, and the molecular sieves include at least one of BETA molecular sieve, USY molecular sieve, and ZSM-5 molecular sieve. The load can carry the catalyst, improve the dispersion of the catalyst, make it evenly distributed on the surface of the catalytic coating, and fully expose its catalytic active sites to the air.

[0065] In some embodiments, the particle size of the binder is 100 nm - 200 nm. For example, the particle size can be any one of 100 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, etc. within the range of 100 nm - 200 nm. Under the above particle size conditions, the binder is not easy to agglomerate, can be mixed evenly with the catalyst, and a uniform catalytic coating can be prepared. Moreover, the catalyst can firmly adhere to the surface of the binder and be fixed on the surface of the catalytic coating through the binder.

[0066] The present invention provides a preparation method of a binder, comprising the following steps:

[0067] Mix terminal hydroxyl silicone oil, silane coupling agent, silicate ester, co-solvent, pH regulator, and water to obtain a mixed solution;

[0068] Heat the mixed solution to obtain the binder.

[0069] The present invention uses terminal hydroxyl silicone oil, silicate ester, and silane coupling agent as reaction monomers. The above reaction monomers are mixed evenly with the help of a co-solvent, and then hydrolytic polycondensation occurs under the conditions of water and a pH regulator to generate the binder.

[0070] The binder prepared by the above preparation method has the high-temperature resistance of an inorganic binder and is not easy to decompose under high-temperature conditions above 300 °C. It also has the toughness of an organic binder, high bonding efficiency, and is applied to the preparation of the catalytic coating of cooking utensils. A small amount of addition has good adhesion, can firmly fix the catalyst on the surface of the catalytic coating without completely covering the catalyst, and can meet the requirements of fully exposing the catalyst in the catalytic coating to the air and the catalytic coating not being prone to powder falling.

[0071] In some embodiments, the binder prepared by the present invention has the following chemical structural formula:

[0072]

[0073] Wherein, n is greater than or equal to 1.

[0074] In the present invention, the silane coupling agent can undergo hydrolysis and polycondensation reactions with hydroxyl-terminated silicone oil and silicate ester to generate an adhesive that has both the high-temperature resistance of inorganic silicon materials and the excellent toughness of silicone materials. The adhesive is not easily decomposed under high-temperature conditions above 300 °C, has high bonding efficiency, and is applied to the preparation of a catalytic coating for cooking utensils. A small amount of addition has good bonding strength, can firmly fix the catalyst on the surface of the substrate without completely covering the catalyst, and can meet the requirements of fully exposing the catalyst in the catalytic coating to the air and the catalytic coating not being prone to powder falling.

[0075] In some embodiments, the silicate ester includes at least one of tetraethyl orthosilicate and tetramethoxysilane. The silicate esters of the above types are easy to undergo hydrolysis and polycondensation reactions with hydroxyl-terminated silicone oil and silane coupling agent to form an adhesive with a stable structure, making it have excellent high-temperature resistance and toughness and showing excellent bonding strength.

[0076] In some embodiments, the silane coupling agent includes at least one of γ-glycidoxypropyltrimethoxysilane (KH560), γ-aminopropyltrimethoxysilane (KH550), γ-methacryloxypropyltrimethoxysilane (KH-570), (3,3,3-trifluoropropyl)trimethoxysilane, and methyltrimethoxysilane. The silane coupling agents of the above types can undergo hydrolysis and polycondensation reactions with hydroxyl-terminated silicone oil and silicate ester to generate an adhesive with a stable structure, making it have excellent high-temperature resistance and toughness and showing excellent bonding strength.

[0077] In some embodiments, the viscosity of the hydroxyl-terminated silicone oil is 100 cP - 500 cP. For example, it can be any viscosity value within the range of 100 cP - 500 cP such as 100 cP, 130 cP, 140 cP, 150 cP, 180 cP, 200 cP, 210 cP, 240 cP, 250 cP, 270 cP, 300 cP, 350 cP, 370 cP, 390 cP, 400 cP, 420 cP, 450 cP, 460 cP, 480 cP, 500 cP, etc. The hydroxyl-terminated silicone oil with the above viscosity range can endow the adhesive with strong adhesion. When applied to the preparation of a catalytic coating, it is more likely to meet the requirements of fully exposing the catalyst in the catalytic coating to the air and not being prone to powder falling. In addition, it is not easy for the hardness of the adhesive to be too high due to the too high viscosity of the hydroxyl-terminated silicone oil, thereby affecting the preparation and molding of the catalytic coating.

[0078] It should be noted that the above restrictions on the types of silane coupling agents, silicate esters, and the physical and chemical properties of hydroxyl-terminated silicone oil can satisfy only one of them, or can be satisfied simultaneously. Satisfying them simultaneously is beneficial to promoting the hydrolysis and polycondensation reaction among the silane coupling agent, silicate ester, and hydroxyl silicone oil, obtaining an adhesive that has both high-temperature resistance and excellent toughness and exhibits excellent adhesion. The catalytic coating of the cooking utensil prepared from this adhesive is not prone to powder falling even when working at 300 °C. Moreover, adding a small amount of the adhesive can firmly fix the catalyst on the surface of the coating and enable the catalyst to be fully exposed to the air to directly contact with oil fume / oil pollutants, improving the oxidation degradation effect.

[0079] In some embodiments, the weight ratio of hydroxyl-terminated silicone oil, silane coupling agent, silicate ester, co-solvent, pH regulator, and water is: (1 - 5) : (1 - 5) : (30 - 50) : (40 - 70) : (1 - 3) : (5 - 10); for example, calculated by weight, the addition amount of hydroxyl-terminated silicone oil can be any weight in the range of 1 - 5 parts such as 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.; the addition amount of the silane coupling agent can be any weight in the range of 1 - 5 parts such as 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.; the addition amount of the silicate ester can be any weight in the range of 30 - 50 parts such as 30 parts, 32 parts, 35 parts, 36 parts, 37 parts, 40 parts, 42 parts, 45 parts, 46 parts, 49 parts, 50 parts, etc.; the co-solvent can be any weight in the range of 40 - 70 parts such as 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, etc.; the pH regulator can be any weight in the range of 1 - 3 parts such as 1 part, 1.5 parts, 2 parts, 2.5 parts, 2.8 parts, 3 parts; the water can be any weight in the range of 5 - 10 parts such as 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0080] The purpose of adding the pH regulator in the present invention is to adjust the pH range of the mixed solution to 1 - 5, that is, the pH value of the mixed solution can be adjusted to any pH value within the range of 1 - 5 such as 1.3, 1.5, 1.8, 2, 2.2, 2.5, 2.7, 3, 3.3, 3.5, 3.8, 4, 4.1, 4.4, 4.5, 4.7, 4.9, 5, etc. Under the above pH conditions, it can promote the hydrolysis of hydroxyl-terminated silicone oil, silicate ester, and silane coupling agent, and then carry out polycondensation to form an adhesive.

[0081] In some embodiments, the heating temperature of the mixed solution is 60 °C - 80 °C. For example, it can be any temperature value within the range of 60 °C - 80 °C such as 60 °C, 63 °C, 65 °C, 67 °C, 68 °C, 69 °C, 70 °C, 72 °C, 75 °C, 77 °C, 79 °C, 80 °C, etc. Under the above temperature conditions, it is beneficial to promoting the hydrolysis and polycondensation reaction of hydroxyl-terminated silicone oil, silicate, and silane coupling agent to obtain an adhesive.

[0082] In some embodiments, the heating time of the mixed solution is 2 h - 5 h. For example, it can be any time value within the range of 2 h - 5 h, such as 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, etc. Under the above heating time conditions, it is beneficial to obtain an adhesive with higher yield.

[0083] In some embodiments, after the heating reaction of the mixed solution is completed, it can be cooled to room temperature and left to stand for 20 h - 30 h. For example, it can be 20 h, 22 h, 24 h, 25 h, 26 h, 27 h, 29 h, 30 h. After standing for a period of time, it is beneficial to obtain an adhesive with a stable particle size state.

[0084] The adhesive prepared by the preparation method of the adhesive as described above in the present invention can be used to prepare a catalytic coating material applied to cooking utensils. A catalytic coating is formed from the catalytic coating material to oxidize and degrade the oil stains generated during cooking, making the cooking utensils easy to clean. For example, the above-mentioned adhesive can be mixed with a catalyst to form a catalytic coating material, and then a catalytic coating is prepared and formed on the surface of the substrate.

[0085] The adhesive prepared in the present invention has the high-temperature resistance of an inorganic adhesive and is not easily decomposed under high-temperature conditions above 300 °C. It also has the toughness of an organic adhesive, high bonding efficiency. When applied to prepare the catalytic coating of cooking utensils, a small amount of addition has good bonding force, can firmly fix the catalyst on the surface of the substrate without completely covering the catalyst, and can meet the requirements of fully exposing the catalyst in the catalytic coating to the air and not easily showing powder falling.

[0086] The adhesive of the present invention also has good lipophilic properties. When used to prepare a catalytic coating, it can combine with the catalyst to produce micro-nano cluster and slit belt morphologies, so that the formed catalytic coating has an oil contact angle less than or equal to 5°. The surface is randomly distributed with catalyst clusters with a height of 0.1 μm - 150 μm and a diameter of 0.1 μm - 500 μm, and catalyst slit belts with a width of 1 μm - 10 μm and a depth of 1 μm - 100 μm. Specifically, catalyst clusters and slit belts are formed on the surface of the catalytic coating, so that the oil fume / grease pollutants are fully exposed and temporarily stored on the inner surface of the tiny slits on the surface of the catalytic coating. While the formation of clusters and slit structures can increase the contact area with the catalyst, the pollutant molecules are "caught" by the surface slits of the catalytic coating for full reaction, further improving the catalytic effect and accelerating the oxidation and degradation of oil fume / grease pollutants. In addition, it can also make the surface of the catalytic coating form millimeter-scale, micron-scale, and nano-scale catalyst clusters interpenetrating each other, enhancing the mechanical stability of the catalytic coating. Further, the adhesive of the present invention can promote the catalytic coating to obtain a water contact angle greater than or equal to 120°, avoid the competitive adsorption of water vapor and grease on the surface of the catalytic coating, and also increase the water resistance of the coating.

[0087] The present invention also provides a catalytic coating applied to a cooking utensil, wherein the catalytic coating is prepared from the catalytic coating material of the present invention as described above. It should be noted that the catalytic coating of the present invention can be applied to parts of the cooking utensil that are easily exposed to oil smoke / grease pollutants, for example, including but not limited to the surface of the heating module of the cooking utensil and / or any inner surface in the cooking cavity.

[0088] The present invention does not limit the method for preparing the catalytic coating material to form the catalytic coating, and a preparation method familiar to those skilled in the art may be selected. In some embodiments, the catalytic coating material may be sprayed onto the surface of the substrate to form the catalytic coating.

[0089] In some embodiments, the catalyst portion in the catalytic coating is exposed to the air and can directly contact the oil fume / grease pollutants, thereby rapidly oxidizing and degrading the oil fume / grease pollutants, making the cooking utensils easier to clean.

[0090] In some embodiments, the roughness of the catalytic coating is 140 μm-370 μm. For example, the roughness of the catalytic coating can be 140 μm, 145 μm, 150 μm, 155 μm, 160 μm, 170 μm, 190 μm, 200 μm, 210 μm, 230 μm, 250 μm, 270 μm, 280 μm, 300 μm, 310 μm, 330 μm, 350 μm, 360 μm, 370 μm, etc. Under the above roughness conditions, the catalytic coating has good oleophilicity, and the oil smoke / grease pollutants are fully exposed to the surface of the catalytic coating, increasing the contact area with the catalyst and accelerating the oxidation and degradation of the oil smoke / grease pollutants.

[0091] In some embodiments, catalyst clusters with a height of 0.1 μm to 150 μm and a diameter of 0.1 μm to 500 μm are randomly distributed on the surface of the catalytic coating.

[0092] The smoke / grease pollutants are fully exposed and temporarily stored on the inner surface of the tiny slits on the surface of the catalytic coating, forming a cluster structure that can increase the contact area with the catalyst. At the same time, the pollutant molecules are "caught" by the surface slits of the catalytic coating to fully react, further improving the catalytic effect and accelerating the oxidation and degradation of smoke / grease pollutants. Moreover, it is conducive to the catalytic coating to form an oil contact angle of less than or equal to 5°.

[0093] In some embodiments, catalyst slit bands with a width of 1 μm to 10 μm and a depth of 1 μm to 100 μm are randomly distributed on the surface of the catalytic coating. In this embodiment, catalyst slit bands are formed on the surface of the catalytic coating, enabling the oil fume / grease pollutants to be fully exposed and temporarily stored on the inner surface of the tiny slits on the surface of the catalytic coating. While the formation of the slit bands can increase the contact area with the catalyst, the pollutant molecules are "caught" by the surface slits of the catalytic coating for sufficient reaction, further improving the catalytic effect and accelerating the oxidative degradation of the oil fume / grease pollutants. Moreover, it is beneficial to promote the formation of an oil contact angle of less than or equal to 5° on the catalytic coating.

[0094] In some embodiments, the oil contact angle of the catalytic coating is less than or equal to 5°, which can be an oil contact angle less than or equal to 5° such as 5°, 4°, 3°, 2°, or 1°. The catalytic coating with the above oil contact angle less than or equal to 5° can fully expose the oil fume / grease pollutants on the surface of the catalytic coating, increase the contact area with the catalyst, and accelerate the oxidative degradation of the oil fume / grease pollutants.

[0095] The present invention also provides a cooking appliance, which includes the catalytic coating as described above in the present invention.

[0096] In some embodiments, the catalytic coating is coated on the surface of the heating module of the cooking appliance and / or any inner surface of the cooking cavity. In some cooking appliances, the heating module will be in direct contact with the food. Coating the catalytic coating on the heating module can achieve the oxidative degradation of the oil fume / grease pollutants generated during cooking during the cooking process; while the inner surface of the cooking cavity is usually in direct contact with the food, coating the catalytic coating on any inner surface of the cooking cavity can also achieve the oxidative degradation of the oil fume / grease pollutants generated during cooking during the cooking process.

[0097] In some embodiments, the cooking appliance includes an air fryer, an electric pressure cooker, a griddle, an automatic stir-fry machine, or an electric griddle. The catalytic coating can be coated on the surface of the heating module of the above cooking appliances and / or any inner surface of the cooking cavity and other surfaces that are easily contaminated by oil fume / grease pollutants.

[0098] In some embodiments, the cooking appliance is an air fryer. In an air fryer, food ingredients are generally placed near the bottom of the accommodating cavity. Since the working mode of an air fryer is usually to drive the cooking medium, i.e., hot air flow, in the accommodating cavity to circulate rapidly through the operation of a fan, and the fan is located near the top wall of the accommodating cavity, the negative pressure area formed by the operation of the fan causes the cooking medium carrying oil fume / oil pollutants to preferentially contact the top wall position, resulting in the top wall being the most likely to accumulate oil fume / oil pollutants. Moreover, the top wall of the air fryer is generally not detachable and is not easy to clean. In addition, the working temperature of the air fryer can sometimes reach above 300 °C, especially the heating module, which is in a high-temperature state for a long time. The catalytic coatings in the prior art may be difficult to simultaneously consider the high-temperature resistance performance and the bonding effect of the adhesive. When working at a high temperature of 300 °C for a long time, it is easy to decompose itself due to poor high-temperature resistance performance, or cause powder falling due to poor bonding effect. However, the catalytic coating of the present invention can withstand high temperatures above 300 °C, is not easy to decompose when working at high temperatures for a long time, and has a good bonding effect and is not easy to cause powder falling. In this embodiment, the thermal catalytic functional coating can cover any surface in the accommodating cavity such as the top wall of the accommodating cavity of the air fryer in this embodiment and the surface of the heating module, catalytically degrade the oil fume / oil pollution pollutants, and has a relatively high catalytic efficiency, which is beneficial to keeping the inner wall of the accommodating cavity clean.

[0099] The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not used to limit the present invention.

[0100] Preparation of adhesive

[0101] The preparation method of the adhesive includes the following steps:

[0102] S10. Weigh the raw materials according to Table 1, dissolve the hydroxyl-terminated silicone oil, silane coupling agent, and silicate ester in the co-solvent and water, and then adjust the pH with a pH regulator to obtain a mixed solution with a pH of 1-5.

[0103] S20. Heat and react the mixed solution in step S10 at 60-80 °C for 3 h, and then cool to room temperature and stand for 24 h to obtain 5 adhesives numbered A-E.

[0104] Preparation of catalytic coating material

[0105] Examples 1 to 7

[0106] Weigh the raw materials according to Table 2, and then mix and stir evenly the adhesive, catalyst, and water to obtain the catalytic coating material.

[0107] Comparative Example 1

[0108] Comparative Example 1 Refer to the preparation method of Example 1, except that in Comparative Document 1, a commercially available sodium silicate inorganic binder was used.

[0109] Comparative Example 2

[0110] Comparative Example 2 Refer to the preparation method of Example 1, except that in Comparative Document 1, a commercially available BASF STYROFAN ECO 7623 styrene-butadiene latex organic binder was used.

[0111] Comparative Example 3

[0112] Comparative Example 3 On the basis of Comparative Example 1, the amount of the commercially available inorganic binder was increased, and at the same time, the amount of the catalyst was correspondingly reduced.

[0113] Table 1 Raw material ratios of examples and comparative examples (weight percentage)

[0114] Experimental group Hydroxyl-terminated silicone oil Silane coupling agent (type / content) Silicate (type / content) pH regulator (formic acid) Water A 5 KH560 / 4 30 2 5 B 4 KH550 / 3 40 3 10 C 1 KH570 / 3 30 1 6 D 3 KH570 / 2 50 3 10 E 2 KH550 / 1 30 2 8

[0115] Table 2 Raw material ratios of the catalytic coating materials of examples and comparative examples (weight percentage)

[0116]

[0117]

[0118] Performance test

[0119] The catalytic coating materials in Examples 1 to 7 and Comparative Example 1 were respectively sprayed on the surface of a pure aluminum plate as the substrate to form a catalytic coating with a thickness of 500 μm. Among them, the schematic structural diagram of the catalytic coating prepared in the example refers to Figure 1 , as Figure 1 shown, the catalytic coating includes a substrate 1, a binder 2 and a catalyst 3, and the catalyst 3 is adhesively fixed to the surface of the substrate 1 through the binder 2 and is fully exposed to the air.

[0120] Test 1: The aluminum plates coated with the catalytic coating were respectively placed on a constant temperature table at 100 °C, 150 °C, 200 °C, and 300 °C, so that the surface temperature of the coating reached the set temperature of the constant temperature table and remained constant. A 50 μL drop of soybean cooking oil was added to the coating surface with a pipette. According to the severity of the reaction, it was divided into three levels: violent reaction, slow reaction, and no reaction. The specific descriptions are as follows:

[0121] Violent reaction: When the soybean oil was dropped on the coating surface, visible smoking and sparking and other reaction phenomena occurred within 1 minute;

[0122] Slow reaction: When the soybean oil was dropped on the coating surface, visible smoking or sparking and other reaction phenomena occurred within 5 minutes;

[0123] No reaction: When soybean oil is dropped onto the surface of the coating, the oil droplet remains in a liquid state and wets the coating surface, without any obvious chemical reaction occurring.

[0124] Test 2: After completing Test 1, observe whether there is any powder shedding on the catalytic coating.

[0125] Test 3: Adhesion test: Adhesion: Draw an X line and use 3M tape to tear it off to observe whether the coating peels off.

[0126] Grade 0: The cutting edge is completely smooth and none of the grids peel off.

[0127] Grade 1: There is a little paint film peeling off at the cutting intersections, and the affected cross-cutting area should not be greater than 5%.

[0128] Grade 2: There is paint film peeling off at the cutting edge and / or intersections. The affected cutting area is greater than 5% but less than 15%.

[0129] Grade 3: The paint film partially or completely peels off in large pieces along the cutting edge, and / or partially or completely peels off at different parts of the grids. The affected cutting area is greater than 15% and less than 35%.

[0130] Grade 4: The paint film peels off in large pieces along the cutting edge and / or partially or completely peels off at some grids. The affected cutting area is greater than 35% and less than 65%.

[0131] Grade 5: Any degree of peeling exceeding Grade 4.

[0132] Test 4: Oil contact angle and water contact angle test: Use a contact angle measuring instrument to test the contact angles of soybean oil and water, with a droplet volume of 3 μL.

[0133] The data of the above Tests 1 to 3 are shown in Table 3.

[0134] Table 3 Test results of the catalytic coating performance of the examples and comparative examples

[0135]

[0136] As can be seen from Tables 1 to 3: The catalytic coatings of Examples 1 to 7 applying the binder of the present invention have good oxidation degradation effects on oils and fats, and are not prone to powder shedding during operation at 300 °C. They have both high-temperature resistance and excellent adhesion. A small amount of addition can exert good bonding performance, firmly fix the catalyst on the surface of the substrate, and fully expose the catalyst to the air, enabling the catalytic coating to exert a great catalytic degradation effect on oil fume / oil and fat pollutants, and can oxidatively degrade oil fume / oil and fat pollutants at 100 °C to 300 °C.

[0137] In Comparative Example 1, a catalytic coating was prepared using commercially available inorganic binder sodium silicate, with poor adhesion, and the coating was prone to powder shedding, which would affect the catalytic effect.

[0138] In Comparative Example 2, a commercially available organic binder, styrene-butadiene latex, was used to prepare the catalytic coating, and the phenomenon of powder shedding also occurred.

[0139] In Comparative Example 3, a commercially available inorganic binder, water glass, was used to prepare the catalytic coating. When the amount of the inorganic binder reached 65%, after the oxidation degradation of the grease was carried out at 300 °C, although the coating did not show the phenomenon of powder shedding, because the content of the catalyst was too small and because the content of the binder was too high, the catalyst might be wrapped up, and it was difficult for the catalyst to be fully exposed to the air to directly contact with the grease, and its catalytic oxidation effect became poor.

[0140] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A catalytic coating material for cooking utensils, characterized in that, the catalytic coating material comprises an adhesive and a catalyst, and the adhesive has the following structural formula: wherein, n is greater than or equal to 1.

2. The catalytic coating material according to claim 1, characterized in that, calculated by weight percentage, the content of the adhesive in the catalytic coating material is 20%-40%; and / or, the content of the catalyst in the catalytic coating material is 20%-40%.

3. The catalytic coating material according to claim 1, characterized in that, the catalytic coating material further comprises water and / or a loading substance.

4. The catalytic coating material according to claim 1, characterized in that, the catalyst is a metal oxide catalyst.

5. The catalytic coating material according to claim 1, characterized in that, the particle size range of the catalyst is 5μm - 10μm.

6. The catalytic coating material according to claim 1, characterized in that, the solid content of the adhesive is 32%-60%.

7. The catalytic coating material according to claim 6, characterized in that, the solid content of the adhesive is 45%-55%.

8. The catalytic coating material according to claim 1, characterized in that, the particle size of the adhesive is 100 - 200nm.

9. A preparation method of an adhesive, characterized in that, comprises the following steps: mixing hydroxyl-terminated silicone oil, silane coupling agent, silicate ester, co-solvent, pH regulator and water to obtain a mixed solution; heating the mixed solution to obtain the adhesive.

10. The preparation method of the adhesive according to claim 9, characterized in that, the silicate ester comprises at least one of tetraethyl orthosilicate and tetramethoxysilane.

11. The preparation method of the adhesive according to claim 10, characterized in that, the silane coupling agent comprises at least one of γ-glycidoxypropyltrimethoxysilane (KH560), γ-aminopropyltrimethoxysilane (KH550), γ-methacryloxypropyltrimethoxysilane (KH570), (3,3,3-trifluoropropyl)trimethoxysilane and methyltrimethoxysilane.

12. The preparation method of the adhesive according to claim 9, characterized in that, the pH of the mixed solution is 1 - 5.

13. The preparation method of the adhesive according to claim 9, characterized in that, the viscosity of the hydroxyl-terminated silicone oil is 100cP - 500cP.

14. The preparation method of the adhesive according to claim 9, characterized in that, the weight ratio of the hydroxyl-terminated silicone oil, silane coupling agent, silicate ester, co-solvent, pH regulator and water is: (1 - 5):(1 - 5):(30 - 50):(40 - 70):(1 - 3):(5 - 10).

15. The preparation method of the adhesive according to claim 9, characterized in that, the heating temperature of the mixed solution is 60°C - 80°C; and / or, the heating time of the mixed solution is 2h - 5h.

16. A catalytic coating, applied to cooking utensils, characterized in that, The catalytic coating is prepared from the catalytic coating material according to any one of claims 1 to 8.

17. The catalytic coating according to claim 16, wherein, part of the catalyst is exposed to air.

18. The catalytic coating according to claim 16, wherein, the roughness of the catalytic coating is 140 μm - 370 μm.

19. The catalytic coating according to claim 16, wherein, catalyst clusters with a height of 0.1 μm to 150 μm and a diameter of 0.1 μm to 500 μm are randomly distributed on the surface of the catalytic coating.

20. The catalytic coating according to claim 16, wherein, catalyst slit bands with a width of 1 μm to 10 μm and a depth of 1 μm to 100 μm are randomly distributed on the surface of the catalytic coating.

21. The catalytic coating according to claim 16, wherein, the oil contact angle of the catalytic coating is less than or equal to 5°.

22. The catalytic coating according to claim 16, wherein, the water contact angle of the catalytic coating is greater than or equal to 120°.

23. A cooking appliance, wherein, the cooking appliance includes the catalytic coating according to any one of claims 16 to 22.

24. The cooking appliance according to claim 23, wherein, the catalytic coating is coated on the surface of the heating module of the cooking appliance and / or any inner surface of the cooking cavity.

25. The cooking appliance according to claim 23, wherein, the cooking appliance includes an air fryer, an electric pressure cooker, a griddle, an automatic cooking machine or a griddle.

26. The cooking appliance according to claim 25, wherein, the cooking appliance is an air fryer, and the catalytic coating is coated on the heating component of the air fryer.

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