Antibacterial coatings, antibacterial cookware and their preparation methods

Abstract

The present invention discloses an antibacterial coating, an antibacterial cookware and a preparation method thereof, belonging to the technical field of cooking utensils. Among them, the antibacterial coating comprises raw materials with the following mass fractions: 20%-30% of siloxane, 18%-27% of silica sol, 1%-5% of zwitterionic sulfobetaine silane, 1%-10% of cosolvent, 1%-5% of polysiloxane, 0.1%-0.5% of acid catalyst, and the balance is water. The coating of the present invention uses zwitterionic sulfobetaine silane as an antibacterial agent, which can significantly improve the long-lasting antibacterial property and coating uniformity of the coating, and reduce the problems of surface oxidation and discoloration or decline in antibacterial performance after long-term use of cooking utensils such as cookware.

Description

Technical Field

[0001] The present invention relates to the technical field of cooking utensils, and particularly to an antibacterial coating, an antibacterial cookware and a preparation method thereof. Background Art

[0002] Antibacterial agents are generally added to the coatings of cooking utensils such as cookware to improve the antibacterial performance. The commonly added antibacterial agents are mainly inorganic antibacterial agents such as nano silver and nano zinc oxide.

[0003] To ensure safety performance, the coatings used for cookware are generally formed by water-based coatings. However, inorganic antibacterial agents have problems of difficult dispersion and easy agglomeration in water. The antibacterial performance of sustained-release antibacterial agents such as metal ions gradually decreases to invalidity with the use time, resulting in a service life of the antibacterial performance of the coating and inability to provide long-lasting antibacterial effect. Moreover, inorganic antibacterial agents such as metal silver ions will generate gray silver oxide when exposed to air, causing the coating to change color, affecting the aesthetics and use safety of the surface of the cookware. Summary of the Invention

[0004] In view of the above problems, the present invention provides an antibacterial coating, an antibacterial cookware and a preparation method thereof, aiming to improve the long-lasting antibacterial property of the coating.

[0005] In a first aspect, the present invention provides an antibacterial coating, comprising raw materials in the following mass fractions:

[0006] Siloxane 20%-30%, silica sol 18%-27%, zwitterionic sulfobetaine silane 1%-5%, cosolvent 1%-10%, polysiloxane 1%-5%, acid catalyst 0.1%-0.5%, and the balance being water.

[0007] In an embodiment, the structural formula of the siloxane is as shown in formula (I):

[0008] Formula (I),

[0009] wherein, R 1 includes one of hydrogen, amino group, mercapto group, glycidyloxy group, and chloro group, and R 2 includes one of methyl group and ethyl group, and m is 1 or 3.

[0010] In an embodiment, the siloxane includes at least one of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, glycidyloxypropyltrimethoxysilane, glycidyloxypropyltriethoxysilane, chloropropyltrimethoxysilane, and chloropropyltriethoxysilane.

[0011] In one embodiment, the zwitterionic sulfobetaine silane has a structural formula shown in Formula (II):

[0012] Formula (II),

[0013] wherein R 2 includes one of methyl and ethyl, and R 3 includes one of methylene, secondary amino group, and amine ester group, m is 1 or 3, and n is 1, 2, or 3.

[0014] In one embodiment, the zwitterionic sulfobetaine silane includes at least one of N,N-dimethylaminoethyl carbamate propyltriethoxysilane sulfonate inner salt, N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate inner salt, and 3-[dimethyl(3-(trimethoxysilyl)propylamino)]propane-1-sulfonate.

[0015] In one embodiment, the solid content of the silica sol is 30% - 50%; and / or, the pH of the silica sol is 8 - 10; and / or, the particle size DV50 of the silica sol is 10 nm - 100 nm.

[0016] In one embodiment, the number-average molecular weight of the polysiloxane is 1000 - 100000.

[0017] In one embodiment, the polysiloxane includes at least one of polydimethylsiloxane, polymethylphenylsiloxane, polyether-modified polysiloxane, alkyl-modified polysiloxane, fluorine-modified polysiloxane, epoxy-modified polysiloxane, and amino-modified polysiloxane.

[0018] In one embodiment, the co-solvent includes at least one of alcohol solvents and ether solvents.

[0019] In one embodiment, the co-solvent includes at least one of methanol, ethanol, isopropanol, propylene glycol methyl ether, and ethylene glycol butyl ether.

[0020] In one embodiment, the acid catalyst includes at least one of formic acid, acetic acid, p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, and nitric acid.

[0021] In one embodiment, the antibacterial coating further includes a pigment dispersion, and the pigment dispersion includes a pigment, a dispersant, an antifoaming agent, a pH regulator, a thickener, and water.

[0022] In one embodiment, the pigment includes at least one of copper chromite black, iron manganese black, titanium dioxide, cobalt blue, cobalt green, cobalt black, titanium chromium brown, iron oxide red, iron oxide yellow, bismuth vanadate, nickel titanium yellow; and / or, the dispersant includes at least one of BYK-191, DISPERBYK-101N; and / or, the defoamer includes at least one of BYK1709, BYK088, BYK024; and / or, the pH regulator includes at least one of hydrochloric acid, acetic acid, sodium hydroxide, sodium bicarbonate; and / or, the thickener includes at least one of bentonite, fumed silica, BYK410.

[0023] In a second aspect, the present invention provides an antibacterial cookware, including a cookware body and an antibacterial coating. The antibacterial coating is disposed on at least a part of the inner surface of the cookware body. The antibacterial coating includes an antibacterial surface layer, and the antibacterial surface layer is formed by any one of the above antibacterial coatings. The antibacterial surface layer includes antibacterial segments and siloxane groups. At least a part of the surface of the antibacterial coating has low surface energy segments inside and / or away from the cookware body; wherein, the antibacterial segments are grafted and connected to the low surface energy segments through siloxane groups.

[0024] In one embodiment, the antibacterial coating further includes a non-stick bottom layer, and the non-stick bottom layer is disposed between the antibacterial surface layer and the inner surface of the cookware body; wherein, at least a part of the surface of the antibacterial surface layer includes antibacterial segments, and the antibacterial segments include zwitterionic sulfobetaine silane segments.

[0025] In one embodiment, the low surface energy segments include a first low surface energy segment and a second low surface energy segment. The first low surface energy segment is disposed on the surface of the non-stick bottom layer facing the antibacterial surface layer, and the second low surface energy segment is disposed on the surface of the antibacterial surface layer facing the non-stick bottom layer. Wherein, the second low surface energy segment is grafted and connected to the first low surface energy segment through siloxane groups.

[0026] In one embodiment, the low surface energy segments have polysiloxane groups, and the polysiloxane groups include at least one of polydimethylsiloxane, polymethylphenylsiloxane, polyether modified polysiloxane, alkyl modified polysiloxane, fluorine modified polysiloxane, epoxy modified polysiloxane, amino modified polysiloxane.

[0027] In one embodiment, the non-stick bottom layer includes raw materials with the following mass fractions: 20%-30% of siloxane, 18%-27% of silica sol, 1%-5% of polysiloxane, 1%-10% of cosolvent, and the balance is water.

[0028] In one embodiment, the thickness of the non-stick bottom layer is 15μm - 25μm, and the thickness of the antibacterial surface layer is 5μm - 15μm.

[0029] In one embodiment, the surface hardness of the antibacterial coating is 6H - 9H.

[0030] In one embodiment, the structural formula of the segment formed by the antibacterial segment, the siloxane group, and the low surface energy segment is as shown in Formula (III):

[0031] Formula (III),

[0032] wherein, R 1 includes one of hydrogen, amino group, mercapto group, glycidyloxy group, and chloro group, and R 3 includes one of methylene group, secondary amino group, and amine ester group, m is 1 or 3, and n is 1, 2, or 3.

[0033] In one embodiment, the pot body is a metal pot body, which includes a pot side wall and a pot bottom surface concave on the inner side. Among them, an antibacterial coating is provided on the inner surface of the pot side wall and / or the pot bottom surface, and multiple protrusions are formed on at least part of the surface of the antibacterial coating.

[0034] In a third aspect, the present invention provides a method for preparing an antibacterial cookware, including: providing a pot body; coating any one of the above antibacterial coatings on at least a part of the inner surface of the pot body; drying the pot body coated with the antibacterial coating at 120°C - 170°C for 3 min - 10 min, and then curing it at 250°C - 300°C for 10 min - 25 min to obtain the antibacterial cookware.

[0035] In one embodiment, providing the pot body includes: cleaning and degreasing the surface of the pot body and / or performing sandblasting treatment, and then heating the pot body to 40°C - 50°C.

[0036] In one embodiment, coating any one of the above antibacterial coatings on at least a part of the inner surface of the pot body includes: providing a non-stick coating, and the non-stick coating includes raw materials with the following mass fractions: 20% - 30% of siloxane, 18% - 27% of silica sol, 1% - 5% of polysiloxane, 1% - 10% of co-solvent, and the balance is water; coating the non-stick coating on at least a part of the inner surface of the pot body, drying the pot body coated with the non-stick coating at 120°C - 170°C for 3 min - 10 min, and then curing it at 250°C - 300°C for 10 min - 25 min to obtain a non-stick bottom layer; coating the antibacterial coating on at least a part of the surface of the non-stick bottom layer.

[0037] The antibacterial coating of the present invention uses zwitterionic sulfobetaine silane as an antibacterial agent. One end of it is a zwitterionic betaine compound, which can inhibit the formation of biofilms, prevent bacteria from adhering, and can destroy the cell membrane structure of bacteria through electrostatic adsorption to achieve the purpose of sterilization and antibacterial.

[0038] Zwitterionic sulfobetaine silane contains both cations and anions and belongs to zwitterionic surfactants. It can interact with water molecules through electrostatic action in water, which helps to be uniformly dispersed in water, thereby helping to improve the antibacterial property of the coating.

[0039] In addition, siloxane and zwitterionic sulfobetaine silane can be catalytically hydrolyzed under the action of an acid catalyst. After hydrolysis, the siloxane, zwitterionic sulfobetaine silane, silica sol, and polysiloxane form a dense coating through hydroxyl dehydration condensation crosslinking. The zwitterionic sulfobetaine silane segment and the polysiloxane segment are grafted and fixed in the antibacterial coating by the silicon-oxygen-silicon bond (Si-O-Si) of the siloxane group, and the chemical bond combination is stronger, so that a long-lasting antibacterial effect can be obtained. In addition, the present invention does not use metal antibacterial ions such as nano silver as antibacterial agents, reducing the problem of surface oxidation and discoloration of cooking utensils such as pans after long-term use.

[0040] Secondly, the antibacterial coating includes a non-stick bottom layer and an antibacterial surface layer. At least part of the surface of the antibacterial surface layer includes zwitterionic sulfobetaine silane segments and / or polysiloxane segments. The zwitterionic sulfobetaine silane segments have long-lasting and lossless antibacterial properties, and the polysiloxane segments have a low surface energy and excellent hydrophobic non-stick properties. The two make the antibacterial coating have long-lasting antibacterial and non-stick properties under the action of chemical bonding, and have a high hardness. Coated on the surface of the antibacterial pan, it can meet the wear resistance and corrosion resistance, and the bonding force between the antibacterial coating and the pan substrate surface is strong. The graft connection of the siloxane group further improves the bonding force and scratch resistance between the non-stick bottom layer and the antibacterial surface layer, does not affect the service life of the antibacterial pan, and obtains long-lasting antibacterial and non-stick properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic longitudinal sectional view of an antibacterial pan in some embodiments of the present invention;

[0042] Figure 2 It is a schematic longitudinal sectional view of an antibacterial pan in other embodiments of the present invention.

[0043] REFERENCE SIGNS

[0044] 100, antibacterial pan; 11, pan body; 111, pan side wall; 112, pan bottom surface; 12, antibacterial coating; 121, antibacterial surface layer; 122, non-stick bottom layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0046] The "ranges" disclosed in the present invention are defined in the form of lower and upper limits. A given range is defined by selecting a lower limit and an upper limit, and the selected lower and upper limits define the boundaries of the particular range. The ranges defined in this way can include or exclude the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, ranges of 60-110 and 80-120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present invention, unless otherwise specified, the numerical range "a-b" represents an abbreviated representation of any real number combination between a and b, where both a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are fully listed herein, and "0-5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0047] In the description of the embodiments of the present invention, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this document, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0048] In the description of the embodiments of the present invention, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces). The term "at least one" means one or more.

[0049] Referring to "embodiments" in the present invention means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present invention. The appearance of this phrase at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0050] At present, inorganic antibacterial agents such as nano silver and nano zinc oxide are usually added to waterborne coatings for cooking utensils such as inner pots, inner liners, frying pans, and soup pots to improve antibacterial performance. However, the nano silver and nano zinc oxide particles are small in size, large in surface area, and have relatively high surface energy, so they will spontaneously agglomerate in water. In addition, there is a strong van der Waals force between the nano particles, and this attraction will also cause the nano silver and nano zinc oxide particles to approach and agglomerate with each other. Therefore, inorganic antibacterial agents such as nano silver and nano zinc oxide have problems of poor dispersibility and easy agglomeration in water, resulting in a decline in the long-term antibacterial performance of the coating.

[0051] To solve the above problems, the present invention uses zwitterionic sulfobetaine silane as an antibacterial agent. One end of it is a zwitterionic betaine compound, which can inhibit the formation of biofilms, prevent bacteria from adhering, and can also destroy the cell membrane structure of bacteria through electrostatic adsorption to achieve the purpose of sterilization and antibacterial. Siloxane and zwitterionic sulfobetaine silane can be catalytically hydrolyzed under the action of an acid catalyst. After hydrolysis, the siloxane, zwitterionic sulfobetaine silane, silica sol, and polysiloxane form a dense coating through hydroxyl dehydration condensation cross-linking. The zwitterionic sulfobetaine silane chain segments are fixed in the coating, and the chemical bond binding is stronger, so that a lasting and efficient antibacterial effect can be obtained.

[0052] According to some embodiments of the present invention, the present invention provides an antibacterial coating, which includes raw materials with the following mass fractions: 20%-30% of siloxane, 18%-27% of silica sol, 1%-5% of zwitterionic sulfobetaine silane, 1%-10% of co-solvent, 1%-5% of polysiloxane, 0.1%-0.5% of acid catalyst, and the balance is water.

[0053] Zwitterionic sulfobetaine silane refers to a compound with a zwitterionic betaine structure at one end and a silyl group at the other end.

[0054] The zwitterionic betaine structure includes a cationic group and an anionic group. The cationic group will have an electrostatic attraction with the anionic phospholipid head on the cell membrane, and at the same time, the anionic group will also interact with the cationic components on the cell membrane, thus disturbing the normal structure and function of the cell membrane, increasing the permeability of the cell membrane, causing the substances inside the cell to leak out, and ultimately causing the death of bacteria. That is, the zwitterionic betaine structure can destroy the cell membrane structure of bacteria through electrostatic adsorption, so as to achieve the purpose of sterilization and antibacterial. In addition, the zwitterionic betaine structure has strong hydrophilicity and will form a highly hydrated layer on the surface of bacteria. This hydrated layer can prevent bacteria from contacting and exchanging with nutrients, water, etc. in the surrounding environment. At the same time, the existence of the hydrated layer can also hinder the mutual aggregation and adhesion of bacteria, reduce the formation of bacterial biofilms, and make bacteria more vulnerable to the influence of the external environment and the attack of the immune system. That is, the zwitterionic betaine structure can inhibit the formation of biofilms and prevent bacteria from adhering, so as to achieve the antibacterial effect.

[0055] In addition, zwitterionic sulfobetaine silane contains both cations and anions and belongs to zwitterionic surfactants. It can interact with water molecules through electrostatic interaction in water, which helps to disperse evenly in water, thus contributing to improving the antibacterial property of the coating. Zwitterionic sulfobetaine silane has hydrophilicity. The greater the addition amount, although the antibacterial effect is better, it will affect its non-stick performance. In order to balance the antibacterial performance and non-stick performance, the addition amount of zwitterionic sulfobetaine silane needs to be controlled below 5%. In this way, good antibacterial performance can be achieved while meeting the non-stick requirement.

[0056] Silica sol refers to a solution formed by dispersing nanoscale silica particles in water. The silica particles in the silica sol can fill the microscopic pores of the coating, reducing the stress concentration points inside the coating. When the coating is subjected to external forces (such as scratching, collision, etc.), it can better disperse the stress. Therefore, silica sol can enhance the mechanical strength of the coating.

[0057] Polysiloxane is a type of polymer with a silicon-oxygen-silicon (Si-O-Si) bond as the main chain and organic groups attached to silicon atoms. The main chain of polysiloxane is composed of silicon-oxygen-silicon bonds. Among them, the bond energy of the silicon-oxygen bond is relatively high, and the molecular chain is relatively flexible. At the same time, the organic groups (such as methyl groups) attached to silicon atoms make the polysiloxane molecule have a relatively low surface energy, so that the coating surface is not easily wetted by other substances. In addition, the addition of polysiloxane enables the coating to form a relatively smooth surface after curing, reducing the friction force and contact area between food and cooking utensils. Therefore, polysiloxane can make the coating have non-stick property, and polysiloxane does not contain fluorine. Compared with fluorinated non-stick coatings, it is more environmentally friendly and durable. The addition amount of polysiloxane is 1%-5%. Too much addition amount will cause floating oil on the coating surface, and too little addition amount will cause poor non-stick property of the coating.

[0058] The siloxane and the silyl groups of zwitterionic sulfobetaine can be catalytically hydrolyzed under an acid catalyst, and the siloxy groups become active silanol groups. The hydrolyzed siloxane, zwitterionic sulfobetaine silane, silica sol and polysiloxane form a dense coating through hydroxy dehydration condensation cross-linking. The zwitterionic sulfobetaine silane chain segments are fixed in the coating, and the chemical bond combination is more firm, so that a long-lasting and efficient antibacterial effect can be obtained.

[0059] The antibacterial coating of the present invention uses zwitterionic sulfobetaine silane as an antibacterial agent, and the antibacterial agent can be evenly dispersed in the water-based coating system, which helps to improve the antibacterial property of the coating.

[0060] According to some embodiments of the present invention, the structural formula of the siloxane is shown in formula (I):

[0061] Formula (I),

[0062] wherein R 1 is one of hydrogen, amino, mercapto, glycidyloxy, and chloro; R 2 is one of methyl and ethyl; and m is 1 or 3.

[0063] The structural formula of glycidyloxy is -O-(CH 2 ) 3 -.

[0064] On the one hand, the siloxane exists as a film-forming substance of the coating. On the other hand, the siloxane will undergo hydrolysis and react with silica sol, polysiloxane, etc. The hydrolysis reaction equation of the siloxane is shown as follows:

[0065] .

[0066] According to some embodiments of the present invention, the siloxane includes at least one of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, glycidyloxypropyltrimethoxysilane, glycidyloxypropyltriethoxysilane, chloropropyltrimethoxysilane, and chloropropyltriethoxysilane.

[0067] According to some embodiments of the present invention, the structural formula of zwitterionic sulfobetaine silane is shown as Formula (II):

[0068] Formula (II),

[0069] wherein R 2 is one of methyl and ethyl; R 3 is one of methylene, secondary amino, and amino ester; m is 1 or 3; and n is 1, 2, or 3.

[0070] The structural formula of methylene is -CH 2 -; the structural formula of secondary amino is -NH-. The amino ester is a functional group containing both an amino group (-NH 2 , -NHR or -NR 2 , where R is an organic group such as an alkyl group) and an ester group (-COOR', where R' is an organic group such as an alkyl group), and is generally formed by the reaction of an amino group and a carbonate ester.

[0071] On the one hand, the zwitterionic sulfobetaine silane exists as an antibacterial agent of the coating. On the other hand, its silyl group can undergo hydrolysis and react with silica sol, polysiloxane, etc. The hydrolysis reaction equation of the zwitterionic sulfobetaine silane is shown as follows:

[0072] 。

[0073] The reaction equations of the zwitterionic sulfobetaine silane, siloxane with silica sol and polysiloxane after hydrolysis are shown as follows:

[0074] 。

[0075] According to some embodiments of the present invention, the zwitterionic sulfobetaine silane includes at least one of N,N-dimethylaminoethyl carbamate propyltriethoxysilane sulfonate, N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate, and 3-[dimethyl(3-(trimethoxysilyl)propylamino)]propane-1-sulfonate.

[0076] In some embodiments, the preparation method of N,N-dimethylaminoethyl carbamate propyltriethoxysilane sulfonate includes the following steps: Take isocyanatopropyltriethoxysilane and N,N-dimethylethanolamine in a molar ratio of 1:1, mix them at room temperature, stir and react for 12 h to obtain an intermediate product and dissolve it with tetrahydrofuran. Slowly drop 1,3-propane sultone into the above solution. The addition amount of 1,3-propane sultone is equimolar to N,N-dimethylethanolamine. Stir at room temperature for 12 h. The whole process is protected by nitrogen and strictly waterproof. Collect the white precipitate and vacuum dry it at 50 °C to obtain N,N-dimethylaminoethyl carbamate propyltriethoxysilane sulfonate.

[0077] In some embodiments, the preparation method of N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate includes the following steps: Take chloromethyltriethoxysilane and triethylamine in a molar ratio of 1:1 in a flask, slowly drop 3-dimethylaminopropylamine equimolar to triethylamine, and reflux and react at 70 °C for 10 h. The whole process is protected by nitrogen and strictly waterproof. The product is filtered to remove the amine salt precipitate, and the filtrate is purified by vacuum distillation to obtain the corresponding intermediate; Take the intermediate and 1,3-propane sultone in a molar ratio of 1:1 and dissolve them in tetrahydrofuran to prepare a 2 mol / L solution. Stir and react at room temperature for 12 h. The whole process is protected by nitrogen and strictly waterproof. Collect the brown precipitate and vacuum dry it at 50 °C to obtain N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate.

[0078] In some embodiments, the preparation method of 3-[dimethyl(3-(trimethoxysilyl)propylamino)] propane-1-sulfonate comprises the following steps: taking (N,N-dimethyl-3-aminopropyl)trimethoxysilane and 1,3-propane sultone in a molar ratio of 1:1, dissolving them in tetrahydrofuran to prepare a 2 mol / L solution, stirring and reacting at room temperature for 12 h, protecting with nitrogen and strictly preventing water throughout the process, collecting the white precipitate, and drying it under vacuum at 50 °C to obtain 3-[dimethyl(3-(trimethoxysilyl)propylamino)] propane-1-sulfonate.

[0079] According to some embodiments of the present invention, the solid content of the silica sol is 30%-50%; and / or, the pH of the silica sol is 8-10; and / or, the particle size D V 50 of the silica sol is 10 nm - 100 nm.

[0080] Silica sol refers to a solution formed by dispersing nano-scale silica particles in water. Therefore, the solid content of the silica sol refers to the mass ratio of the silica particles in the silica sol. Exemplarily, the solid content of the silica sol can be 30%, 32%, 34%, 36%, 38%, 40%, 43%, 45%, 48% or 50%. When the solid content of the silica sol is between 30% and 50%, it helps to improve the bonding ability of the coating; in addition, when the solid content of the alkaline silica sol is between 30% and 50%, it is beneficial for sufficient reaction.

[0081] The pH of the silica sol being between 8 and 10 means that the silica sol is an alkaline silica sol, and the alkaline silica sol can form a good chemical bonding effect with the metal substrate surface of the pot body, enabling the coating to adhere tightly to the pot body surface.

[0082] The particle size D V 50 of the silica sol refers to the particle size D V 50 of the silica particles in the silica sol. The particle size Dv50 refers to the particle size corresponding to the cumulative particle size distribution percentage reaching 50% in the particle size distribution. Exemplarily, the particle size D V 50 of the silica sol can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm. When the particle size D V 50 of the silica sol is between 10 nm and 100 nm, on the one hand, the stability of the silica sol is good and it is not easy to flocculate; on the other hand, a coating with better denseness can be obtained, which helps to improve the durability, corrosion resistance and mechanical properties of the coating.

[0083] According to some embodiments of the present invention, the number average molecular weight of the polysiloxane is 1000 - 100000.

[0084] Polymers usually include polymers with various molecular weights. The number-average molecular weight is the molecular weight statistically averaged according to the number of polymer molecules. Specifically, it is the average value obtained by multiplying the molecular weight of all molecules by their corresponding number of molecules, adding these products together, and finally dividing by the total number of molecules. Exemplarily, the number-average molecular weight of polysiloxane can be 1000, 3000, 5000, 8000, 10000, 30000, 50000, 80000, or 100000. When the number-average molecular weight of polysiloxane is between 1000 and 100000, on the one hand, the polysiloxane has good lyophobicity, which helps to improve the non-stick property of the coating; on the other hand, the polysiloxane with this molecular weight has good lubricating effect. When the molecular weight is too large, the polymer chains enriched on the surface will entangle with each other, thus reducing their motility, and random wrinkles at the nanoscale will appear due to the action of internal stress during the curing process. The existence of these wrinkles will affect the lubricating effect.

[0085] According to some embodiments of the present invention, the polysiloxane includes at least one of polydimethylsiloxane, polymethylphenylsiloxane, polyether-modified polysiloxane, alkyl-modified polysiloxane, fluorine-modified polysiloxane, epoxy-modified polysiloxane, and amino-modified polysiloxane.

[0086] Polydimethylsiloxane has a very low surface energy and can obtain a coating with excellent non-stick performance. Compared with polydimethylsiloxane, polymethylphenylsiloxane has more excellent heat resistance, can withstand higher temperatures, and can maintain the integrity of the coating at high temperatures.

[0087] Polyether-modified polysiloxane refers to a polymer obtained by introducing a polyether chain segment into the polysiloxane structure. The introduction of the polyether chain segment makes the coating have good wettability and enables the liquid to spread better on the coating surface. In addition, polyether-modified polysiloxane has good compatibility with other components, which can make the coating system more stable.

[0088] The introduction of alkyl groups in alkyl-modified polysiloxane enhances the thermal stability of polysiloxane, making the coating not easily decomposed and aged in a high-temperature cooking environment; in addition, the presence of alkyl groups can increase the flexibility of the coating, enabling the coating to withstand the collision and impact suffered by the cookware during use.

[0089] The introduction of fluorine elements in fluorine-modified polysiloxane can further reduce the surface energy, thereby further improving the non-stick property of the coating. The presence of epoxy groups in epoxy-modified polysiloxane enhances the adhesion between the coating and the substrate and between the components inside the coating, and the coating can firmly adhere to the substrate surface and is not easily peeled off. The introduction of amino groups in amino-modified polysiloxane increases the flexibility and elasticity of the coating, enabling the coating to withstand the deformation caused by thermal expansion and contraction or external force impact during the use of cooking utensils.

[0090] It should be noted that polyether-modified polysiloxane, alkyl-modified polysiloxane, fluorine-modified polysiloxane, epoxy-modified polysiloxane, and amino-modified polysiloxane are all existing products, and the present invention does not specifically limit their structures.

[0091] According to some embodiments of the present invention, the co-solvent includes at least one of alcohol solvents and ether solvents.

[0092] The role of the co-solvent in the coating is to assist in film formation and participate in regulating the wetting and leveling properties of the coating.

[0093] Alcohol solvents and ether solvents can reduce the viscosity of the film-forming substance polysiloxane, making the polysiloxane easier to flow and spread. The polysiloxane solution with a lower viscosity can be more evenly distributed on the substrate surface, which is beneficial to the formation of a continuous and uniform film.

[0094] According to some embodiments of the present invention, the co-solvent includes at least one of methanol, ethanol, isopropanol, propylene glycol methyl ether, and ethylene glycol butyl ether.

[0095] According to some embodiments of the present invention, the acid catalyst includes at least one of formic acid, acetic acid, p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, and nitric acid.

[0096] The acid catalyst is used to catalyze the hydrolysis and condensation reaction among silica sol, polysiloxane, zwitterionic sulfobetaine silane, and polysiloxane. In the hydrolysis reaction, the hydrogen ions in the acid can interact with the oxygen atom in the silicon-oxygen bond, causing the electron cloud of the silicon-oxygen bond to shift towards the oxygen atom, thereby increasing the positive charge of the silicon atom. This polarization effect makes the silicon-oxygen bond more vulnerable to the attack of water molecules, reducing the activation energy of the hydrolysis reaction and accelerating the rate of the hydrolysis reaction. In addition, the acid can bind to the silanol intermediate generated during the hydrolysis process through hydrogen bonds, making it more stable and preventing it from re-condensing or decomposing, which is beneficial to the further progress of the hydrolysis reaction.

[0097] In the condensation reaction, the acid can protonate the oxygen atom in the silanol group (Si-OH) to form Si-OH 2 + , and this protonated silanol group has higher reactivity and is more likely to undergo nucleophilic substitution reactions with the oxygen atoms in other silanol groups or polysiloxane molecules to form silicon-oxygen bonds (Si-O-Si).

[0098] According to some embodiments of the present invention, the antibacterial coating further includes a pigment dispersion, and the pigment dispersion includes a pigment, a dispersant, an antifoaming agent, a pH regulator, a thickener, and water.

[0099] The addition of pigments can provide a rich color selection for the coating, and the pigments can also act together with other components in the coating to improve the hiding power of the coating. The dispersant can evenly disperse particles such as pigments in the coating system and prevent the particles from aggregating again, thereby improving the uniformity and stability of the coating.

[0100] According to some embodiments of the present invention, the pigment includes at least one of copper chromite black, iron manganese black, titanium dioxide, cobalt blue, cobalt green, cobalt black, titanium chromium brown, iron oxide red, iron oxide yellow, bismuth vanadate, nickel titanium yellow; and / or, the dispersant includes at least one of BYK-191, DISPERBYK-101N; and / or, the defoamer includes at least one of BYK1709, BYK088, BYK024; and / or, the pH regulator includes at least one of hydrochloric acid, acetic acid, sodium hydroxide, sodium bicarbonate; and / or, the thickener includes at least one of bentonite, fumed silica, BYK410.

[0101] The BYK-191 and DISPERBYK-101N dispersants can deflocculate pigment particles through steric hindrance. Since the deflocculated color powder particles are very small, a coating with high gloss and high color strength can be obtained, and at the same time, the transparency and hiding power of the coating are also increased. Both BYK-191 and DISPERBYK-101N are existing products and are obtained by purchase.

[0102] In some embodiments, the antibacterial coating can also optionally include at least one of a film-forming auxiliary, an antifreezing agent, a filler, a leveling agent, a rheology modifier, a preservative, an ultraviolet absorber, an antioxidant, a matting agent, a lubricant, a vulcanizing agent, and the present invention does not make specific limitations.

[0103] According to some embodiments of the present invention, the present invention also provides an antibacterial cookware 100, as shown in Figure 1 and 2 shown, including a pot body 11 and an antibacterial coating 12. The antibacterial coating 12 is provided on at least a part of the inner surface of the pot body 11. The antibacterial coating 12 includes an antibacterial surface layer 121, and the antibacterial surface layer 121 is formed by any one of the above antibacterial coatings. The antibacterial surface layer 121 includes antibacterial segments and siloxane groups. At least a part of the surface inside and / or away from the pot body 11 of the antibacterial coating 12 has low surface energy segments; wherein, the antibacterial segments are grafted and connected to the low surface energy segments through siloxane groups.

[0104] The antibacterial coating 12 is provided on at least a part of the inner surface of the pot body 11 means that the antibacterial coating 12 can cover the entire inner surface of the pot body 11, or the antibacterial coating 12 can be provided only on the inner surface of parts such as the bottom of the pot.

[0105] The antibacterial coating 12 includes antibacterial segments, siloxane groups, and low surface energy segments. Among them, the antibacterial segments refer to molecular chains with antibacterial properties, and the antibacterial segments endow the antibacterial coating 12 with antibacterial properties. The low surface energy segments refer to molecular chains with relatively low surface energy. When the low surface energy segments come into contact with other substances, they tend to reduce the surface energy to reach a more stable state, with a hydrophobic and non-sticky effect, that is, the adhesion of the low surface energy segments to other substances is small. Therefore, the low surface energy segments endow the antibacterial coating 12 with non-sticky properties.

[0106] The antibacterial segments and the low surface energy segments are grafted and connected through siloxane groups, which means that the antibacterial segments and the low surface energy segments are connected through silicon-oxygen-silicon bonds (Si-O-Si bonds), thereby fixing the antibacterial segments and the low surface energy segments within the antibacterial coating 12, so that the antibacterial coating 12 has long-lasting antibacterial and non-sticky properties. Siloxane is a class of compounds mainly composed of Si-O-Si bonds, with diverse structures, including linear and cyclic forms, and the Si-O-Si bond is a hydrophobic group, which itself has good non-stickiness.

[0107] In addition, due to the bonding effect of the Si-O-Si bonds, the antibacterial segments and the low surface energy segments are simultaneously grafted within the same group and will be evenly distributed on the coated surface, avoiding the situation where antibacterial ions are affected by the preparation process and agglomerate, resulting in uneven distribution of surface antibacterial properties.

[0108] According to some embodiments of the present invention, with further reference to Figure 2 As shown, the antibacterial coating 12 further includes a non-sticky bottom layer 122, and the non-sticky bottom layer 122 is disposed between the antibacterial top layer 121 and the inner surface of the pot body 11; wherein, at least part of the surface of the antibacterial top layer 121 includes antibacterial segments, and the antibacterial segments include zwitterionic sulfobetaine silane segments.

[0109] The antibacterial coating 12 further including the non-sticky bottom layer 122 means that the antibacterial coating 12 can be formed only by the antibacterial top layer 121 or can be formed by the combination of the antibacterial top layer 121 and the non-sticky bottom layer 122.

[0110] The zwitterionic sulfobetaine silane segment refers to a molecular chain with a zwitterionic betaine structure, which includes a cationic group and an anionic group. The cationic group will have electrostatic attraction with the anionic phospholipid head on the cell membrane, and at the same time, the anionic group will also interact with the cationic components on the cell membrane, thus disrupting the normal structure and function of the cell membrane, increasing the permeability of the cell membrane, causing the substances inside the cell to leak out, and ultimately leading to the death of bacteria. That is, the zwitterionic betaine structure can destroy the cell membrane structure of bacteria through electrostatic adsorption, so as to achieve the purpose of sterilization and antibacterial. In addition, the zwitterionic betaine structure has strong hydrophilicity and will form a highly hydrated layer on the surface of bacteria. This hydrated layer can prevent bacteria from contacting and exchanging with nutrients, water, etc. in the surrounding environment. At the same time, the existence of the hydrated layer can also hinder the aggregation and adhesion between bacteria, reduce the formation of bacterial biofilms, and make bacteria more vulnerable to the influence of the external environment and the attack of the immune system. That is, the zwitterionic betaine structure can inhibit the formation of biofilms and hinder bacterial adhesion, so as to achieve the antibacterial effect.

[0111] The antibacterial segment including the zwitterionic sulfobetaine silane segment can be characterized by detection means such as nuclear magnetic resonance hydrogen spectrum, infrared spectrum, and mass spectrum. In some embodiments, a part of the antibacterial surface layer sample can be taken, ground into powder, and then the nuclear magnetic resonance hydrogen spectrum can be measured to characterize the presence of the zwitterionic sulfobetaine silane segment in the antibacterial coating.

[0112] According to some embodiments of the present invention, the low surface energy segment includes a first low surface energy segment and a second low surface energy segment. The first low surface energy segment is disposed on the surface of the non-stick bottom layer 122 facing the antibacterial surface layer 121, and the second low surface energy segment is disposed on the surface of the antibacterial surface layer 121 facing the non-stick bottom layer 122, wherein the second low surface energy segment is grafted and connected to the first low surface energy segment through a siloxane group.

[0113] Take Figure 2 as an example, the first low surface energy segment being disposed on the surface of the non-stick bottom layer 122 facing the antibacterial surface layer 121 means that the first low surface energy segment is disposed on the inner surface of the non-stick bottom layer 122, that is, the inner surface of the non-stick bottom layer 122 has non-stick properties; the second low surface energy segment being disposed on the surface of the antibacterial surface layer 121 facing the non-stick bottom layer 122 means that the second low surface energy segment is disposed on the outer surface of the antibacterial surface layer 121, that is, the outer surface of the antibacterial surface layer 121 has non-stick properties, so that even when the antibacterial surface layer 121 is scraped off and the non-stick bottom layer 122 is exposed, it still has non-stick properties.

[0114] The second low surface energy chain segment is grafted and connected to the first low surface energy chain segment through siloxane groups, that is, the low surface energy chain segments between the antibacterial surface layer 121 and the non-stick bottom layer 122 are connected together through siloxane groups, so that a multi-dimensional siloxane group structure can be formed, greatly improving the bonding force between the surface layer and the bottom layer, reducing the phenomenon of delamination and peeling of the antibacterial surface layer 121, and also improving the non-stick performance.

[0115] According to some embodiments of the present invention, the low surface energy chain segment has a polysiloxane group, and the polysiloxane group includes at least one of polydimethylsiloxane, polymethylphenylsiloxane, polyether modified polysiloxane, alkyl modified polysiloxane, fluorine modified polysiloxane, epoxy modified polysiloxane, and amino modified polysiloxane.

[0116] The polysiloxane main chain is composed of silicon-oxygen bonds, and the bond energy of the silicon-oxygen bonds is relatively high, and the molecular chain is relatively flexible. At the same time, the organic groups (such as methyl groups) connected to the silicon atoms make the polysiloxane molecules have a low surface energy, so that the surface of the coating is not easily wetted by other substances.

[0117] According to some embodiments of the present invention, the non-stick bottom layer includes raw materials in the following mass fractions: 20%-30% of siloxane, 18%-27% of silica sol, 1%-5% of polysiloxane, 1%-10% of co-solvent, and the balance is water.

[0118] Both the non-stick bottom layer 122 and the antibacterial surface layer 121 include siloxane and polysiloxane, which helps to form Si-O-Si bonds at the bonding surface between the non-stick bottom layer 122 and the antibacterial surface layer 121, and form a multi-dimensional network bonding between the two layers through chemical bonding (a chain-like, ring-like, or two-dimensional and three-dimensional structural formula of siloxane groups can be formed), thereby helping to improve the bonding force between the non-stick bottom layer 122 and the antibacterial surface layer 121 and the stability of the coating.

[0119] According to some embodiments of the present invention, the thickness of the non-stick bottom layer 122 is 15μm - 25μm, and the thickness of the antibacterial surface layer 121 is 5μm - 15μm.

[0120] The thicknesses of the non-stick bottom layer 122 and the antibacterial top layer 121 can be measured by observing the cross-section of the antibacterial coating 12 under an electron microscope (such as a scanning electron microscope). Exemplarily, the thickness of the non-stick bottom layer 122 can be 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, or 25μm. When the thickness of the non-stick bottom layer 122 is between 15μm and 25μm, the connection strength between the pot body 11 and the antibacterial top layer 121 can be improved. The thickness of the antibacterial top layer 121 can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, or 15μm, which can not only meet the antibacterial requirements but also reduce the risk of delamination and peeling of the antibacterial top layer 121 due to excessive thickness, and the antibacterial top layer 121 with this thickness can withstand a certain degree of mechanical wear.

[0121] According to some embodiments of the present invention, the surface hardness of the antibacterial coating 12 is 6H - 9H.

[0122] The surface hardness of 6H - 9H refers to the hardness value obtained through the pencil hardness test. The test method includes: using a pencil with a known hardness label to perform a scratch test on the surface of the antibacterial coating 12, and judging the hardness of the coating by the ease of scratching. The pencil hardness is divided into 13 levels from 6H to 6B, where H represents hardness and B represents blackness, and the larger the number, the higher the hardness.

[0123] The surface hardness of the antibacterial coating 12 being 6H - 9H indicates that the antibacterial coating of the present invention has a high hardness, is not easily scratched, and is scratch-resistant and durable.

[0124] According to some embodiments of the present invention, the structural formula of the chain segments formed by the antibacterial segments, siloxane groups, and low surface energy segments is as shown in formula (III):

[0125] Formula (III)

[0126] wherein, R 1 includes one of hydrogen, amino group, mercapto group, glycidyloxy group, and chloro group, and R 3 includes one of methylene group, secondary amino group, and amine ester group, m is 1 or 3, and n is 1, 2, or 3.

[0127] According to some embodiments of the present invention, referring to Figure 1 and 2 as shown, the pot body 11 is a metal pot body, and the pot body 11 includes a pot side wall 111 and a pot bottom surface 112 that is concave on the inner surface. Among them, the inner surface of the pot side wall 111 and / or the pot bottom surface 112 is provided with an antibacterial coating 12, and at least part of the surface of the antibacterial coating 12 forms a plurality of protrusions.

[0128] The surface of the metal pot body is hydrophilic. Therefore, the surface of the metal pot body generally includes hydroxyl groups. The non-stick bottom layer 122 includes silanol groups. The dehydration condensation between the silanol groups and the hydroxyl groups can improve the bonding force between the non-stick bottom layer 122 and the pot body 11.

[0129] That at least part of the surface of the antibacterial coating 12 forms a plurality of protrusions means that at least part of the inner surface of the pot side wall 111 and / or the pot bottom surface 112 is provided with protrusions, and the antibacterial coating 12 is arranged according to the shape of the pot surface, so that the antibacterial coating 12 exhibits a protrusion structure. Arranging a plurality of protrusions on at least part of the inner surface of the pot side wall 111 and / or the pot bottom surface 112 can increase the rough surface, improve the non-stick performance and wear resistance. The antibacterial coating 12 will be arranged according to the shape of the pot surface and will not affect the wear resistance and corrosion resistance of the pot body 11 itself, thus ensuring long-term antibacterial and non-stick properties.

[0130] According to some embodiments of the present invention, the present invention also provides a method for preparing an antibacterial cookware, including: providing a pot body; coating any one of the above antibacterial coatings on at least a part of the inner surface of the pot body; drying the pot body coated with the antibacterial coating at 120°C - 170°C for 3 min - 10 min, and then curing it at 250°C - 300°C for 10 min - 25 min to obtain the antibacterial cookware.

[0131] The pot body can be containers such as a frying pan, a wok, a soup pot, an inner pot of an electric rice cooker, etc. The coating method can be spraying, roll coating, curtain coating or brush coating, and the present invention does not make specific limitations.

[0132] Drying the pot body coated with the antibacterial coating at 120°C - 170°C for 3 min - 10 min. On the one hand, it can make the solvent in the coating volatilize slowly. This slow volatilization process can make the coating level better and reduce the problem of surface unevenness caused by the rapid volatilization of the solvent, such as orange peel phenomenon. On the other hand, during the low-temperature surface drying process, the coating can better penetrate into the microscopic pores of the pot body or undergo a certain chemical reaction with the active groups on the surface of the pot body, thereby forming chemical bonding or physical adsorption, which helps to improve the adhesion of the coating. Exemplarily, the surface drying temperature can be 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C or 170°C; the surface drying time can be 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min.

[0133] Curing at 250°C - 300°C for 10 min - 25 min allows the components in the coating to undergo cross-linking reactions, thereby making the internal structure of the antibacterial coating denser, which in turn helps enhance the hardness, toughness, and corrosion resistance of the antibacterial coating. Exemplarily, the curing temperature can be 250°C, 255°C, 260°C, 265°C, 270°C, 275°C, 280°C, 285°C, 290°C, 295°C, or 300°C; the curing time can be 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, or 25 min.

[0134] According to some embodiments of the present invention, the provided pot body includes: cleaning and degreasing the surface of the pot body and / or performing sandblasting treatment, and then heating the pot body to 40°C - 50°C.

[0135] The cleaning and degreasing of the pot body can be plasma cleaning, alkaline solution cleaning, or organic solvent cleaning. The alkaline solution generally uses sodium hydroxide solution or sodium carbonate solution; the organic solvent can be gasoline, kerosene, trichloroethylene, etc. The sandblasting treatment of the pot body is to obtain a substrate surface with a certain roughness to improve the bonding strength between the antibacterial coating and the pot body. The specific operation of the sandblasting treatment is not specifically limited in the present invention and can be carried out by methods well-known in the art.

[0136] Heating the pot body to 40°C - 50°C causes the viscosity of the coating to decrease and flow easily when the coating contacts the pot body, enabling it to spread evenly on the surface of the pot body, which helps obtain a more uniform antibacterial coating.

[0137] According to some embodiments of the present invention, coating the antibacterial coating on at least a part of the inner surface of the pot body includes: providing a non-stick coating, which includes raw materials with the following mass fractions: 20% - 30% of siloxane, 18% - 27% of silica sol, 1% - 5% of polysiloxane, 1% - 10% of co-solvent, and the balance is water; coating the non-stick coating on at least a part of the inner surface of the pot body, drying the pot body coated with the non-stick coating at 120°C - 170°C for 3 min - 10 min, and then curing at 250°C - 300°C for 10 min - 25 min to obtain a non-stick bottom layer; coating the antibacterial coating on at least a part of the surface of the non-stick bottom layer.

[0138] The following is described in conjunction with specific embodiments.

[0139] Example 1

[0140] An antibacterial coating, based on 100 parts by weight of the total weight of the antibacterial coating, comprises the following raw materials in parts by weight: 25 parts of methyltrimethoxysilane, 20 parts of silica sol, 5 parts of isopropanol, 2 parts of N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate inner salt, 2 parts of polydimethylsiloxane, 0.2 part of formic acid, and 45.8 parts of water. Mixing the above raw materials and stirring for 4 h can obtain the antibacterial coating.

[0141] The solid content of the silica sol is 40%, the pH of the silica sol is 9, the particle size Dv50 of the silica sol is 20 nm, and the number-average molecular weight of the polydimethylsiloxane is 10,000.

[0142] The preparation method of the antibacterial cookware includes:

[0143] Clean and degrease the surface of the aluminum pot body, then preheat the aluminum pot body to 45 °C, and spray 10 μm thickness of the antibacterial coating on the surface of the aluminum pot body; then dry at 150 °C for 5 min first, and then cure at 280 °C for 15 min to obtain the antibacterial cookware.

[0144] Example 2

[0145] Different from Example 1, in this example, the addition amount of N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate inner salt is 1 part, and the addition amount of water is 46.8.

[0146] Example 3

[0147] Different from Example 1, in this example, the addition amount of N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate inner salt is 5 parts, and the addition amount of water is 42.8.

[0148] Example 4

[0149] Different from Example 1, in this example, the antibacterial agent is N,N-dimethylaminoethyl carbamate propyltriethoxysilane sulfonate inner salt.

[0150] Example 5

[0151] Different from Example 1, in this example, the antibacterial agent is 3-[dimethyl(3-(trimethoxysilyl)propylamino)]propane-1-sulfonate.

[0152] Example 6

[0153] Different from Example 1, in this example, the thickness of the antibacterial coating is 5 μm.

[0154] Example 7

[0155] Different from Example 1, in this example, the thickness of the antibacterial coating is 15 μm.

[0156] Comparative Example 1

[0157] Different from Example 1, the coating of this comparative example does not add an antibacterial agent. That is, the coating of this comparative example comprises the following raw materials in parts by weight: 25 parts of methyltrimethoxysilane, 20 parts of silica sol, 5 parts of isopropanol, 2 parts of polydimethylsiloxane, 0.2 part of formic acid, and 46.8 parts of water.

[0158] Comparative Example 2

[0159] Different from Example 1, the coating of this comparative example does not add polysiloxane. That is, the coating of this comparative example comprises the following raw materials in parts by weight: 25 parts of methyltrimethoxysilane, 20 parts of silica sol, 5 parts of isopropanol, 2 parts of N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate inner salt, 0.2 part of formic acid, and 46.8 parts of water.

[0160] Comparative Example 3

[0161] Different from Example 1, in this comparative example, the addition amount of N,N-dimethylaminopropylamine methyltriethoxysilyl sulfonate inner salt is 10 parts, and the addition amount of water is 36.8.

[0162] Comparative Example 4

[0163] Different from Example 1, the antibacterial agent in this comparative example is a silver ion antibacterial agent. That is, the coating of this comparative example comprises the following raw materials in parts by weight: 25 parts of methyltrimethoxysilane, 20 parts of silica sol, 5 parts of isopropanol, 2 parts of silver ion antibacterial agent, 2 parts of polydimethylsiloxane, 0.2 part of formic acid, and 44.8 parts of water.

[0164] Comparative Example 5

[0165] Different from Example 1, the zwitterionic sulfobetaine in this comparative example has no siloxane group (i.e., no Si-O-Si bond), and its chemical structural formula is:

[0166] .

[0167] Performance Test

[0168] Non-stickiness test of fried eggs: Referring to the standard GB / T 32095.1~3-2015 "Non-stick surface performance and test specifications for household food metal cooking utensils", gently wipe the surface of the coating with a soft cloth dipped in vegetable oil, wash it with warm water above 60°C plus detergent, dry it, and then conduct a fried egg test. Place the cooking utensil on an electric furnace with a rated voltage of 220 V and an output power of 1 kW for heating. Measure it with a surface thermometer with an accuracy of not less than 2.5 levels. When the surface temperature of the inner coating reaches 140°C - 170°C, break a fresh egg that meets the requirements of Grade 2 (weight 50g - 60g) of the SB / T 10277 standard and put it into the cooking utensil. Wait until the egg white is basically solidified (during the whole cooking process, the surface temperature of the inner coating shall not exceed 210°C); the egg can be taken out without damage with a non-metallic spatula. If it cannot be taken out without damage, but the residue can be removed by gently wiping with a wet sponge or dishcloth. Evaluate the non-stickiness grade by the number of times of frying eggs.

[0169] Antibacterial property: Referring to the standard GB / T 21866-2008 "Determination method and antibacterial effect of antibacterial coatings (paint films)", respectively drop 0.4mL - 0.5mL of the test bacterial liquid on the negative control sample plate (A), the blank control sample plate (B), and the antibacterial coating sample plate (C). Use sterilized forceps to pick up the sterilized covering film and cover it on sample (A), sample (B), and sample (C) respectively. Make sure it is flattened and has no air bubbles, so that the bacteria can evenly contact the sample. Then place it in a sterilized petri dish and culture it at (37±1)°C and relative humidity RH>90% for 24h. Do 3 parallel tests for each sample. Take out the samples cultured for 24h, add 20mL of washing liquid respectively, and repeatedly wash sample (A), sample (B), sample (C), and the covering film (it is best to pick up the film with forceps and rinse). After sufficient washing, take the washing liquid and inoculate it into the nutrient agar medium (NA), and count the viable bacteria after culturing at (37±1)°C for 24h. Determine the number of viable bacteria in the washing liquid according to the method of GB / T4789.2.

[0170] Persistent antibacterial property

[0171] Put the test plate into boiling water for 50h, and then test the antibacterial property of the test plate referring to the standard GB / T 21866-2008 "Determination method and antibacterial effect of antibacterial coatings (paint films)".

[0172] Test results

[0173] The tests in Examples 1-7 and Comparative Examples 1-5 are shown in Table 1.

[0174] Table 1 Performance of the coatings in Examples 1-7 and Comparative Examples 1-5

[0175]

[0176] As can be seen from Table 1, the antibacterial property and persistent antibacterial property of the antibacterial coating in the embodiments of the present invention are much higher than those of the blank group (without adding antibacterial agent) in Comparative Example 1, indicating that the zwitterionic sulfobetaine silane of the present invention has excellent antibacterial property.

[0177] As can be seen from Examples 1-3 and Comparative Example 3, the greater the addition amount of zwitterionic sulfobetaine silane, the better the antibacterial effect of the coating, but the non-stick performance will decrease. When the addition amount of zwitterionic sulfobetaine silane is 10%, the non-stick property of the fried egg of the coating will be 20 times. Therefore, in order to balance the antibacterial property and non-stick property, the addition amount of zwitterionic sulfobetaine silane needs to be controlled below 5%, so that good antibacterial property can be achieved while meeting the non-stick property requirements.

[0178] As can be seen from Examples 1, 6-7, when the thickness of the antibacterial coating increases, there is no significant impact on the antibacterial property and persistent antibacterial property, but the non-stick performance will increase accordingly. Therefore, when the thickness of the antibacterial coating is between 5μm and 15μm, good non-stick performance and persistent antibacterial property can be ensured.

[0179] Compared with Comparative Example 2, the non-stick property of the fried egg of the antibacterial coating without adding polysiloxane in Comparative Example 2 is 10 times (that is, the pan will stick after frying eggs continuously for 10 times), while the non-stick property of the fried egg in Example 1 of the present invention is 310 times, indicating that the addition of polysiloxane can significantly improve the non-stick property of the coating.

[0180] Compared with Comparative Example 4, the persistent antibacterial property of the antibacterial coating in the embodiments of the present invention is much higher than that of the antibacterial coating added with silver ion antibacterial agent in Comparative Example 4, and the non-stick performance is better. Compared with Comparative Example 5, the persistent antibacterial property of the antibacterial coating in the embodiments of the present invention is much higher than that of the antibacterial coating of zwitterionic sulfobetaine silane without siloxane group in Comparative Example 5, and the non-stick performance is comparable. This shows that the zwitterionic sulfobetaine silane of the present invention can undergo hydroxyl dehydration condensation with silica sol, polysiloxane and siloxane, and the zwitterionic sulfobetaine silane chain segments are fixed in the coating through chemical bonds, so that a persistent and efficient antibacterial effect can be obtained.

[0181] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention by using the content of the specification of the present invention, or directly / indirectly applied to other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An antibacterial coating, characterized in that: The raw materials include the following mass fractions: Siloxane 20%-30%, silica sol 18%-27%, zwitterionic sulfobetaine silane 1%-5%, cosolvent 1%-10%, polysiloxane 1%-5%, acid catalyst 0.1%-0.5%, and the balance is water; The number average molecular weight of the polysiloxane is 10,000-100,000.

2. The antibacterial coating according to claim 1, characterized in that: The structural formula of the siloxane is shown in formula (I): Formula (I), Among them, R 1 Including one of hydrogen, amino, mercapto, glycidyloxy, chloro, R 2 It includes one of methyl and ethyl, and m is 1 or 3.

3. The antibacterial coating according to claim 2, characterized in that: The siloxane includes at least one of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, chloropropyltrimethoxysilane and chloropropyltriethoxysilane.

4. The antibacterial coating according to claim 1, characterized in that: The structural formula of the zwitterionic sulfobetaine silane is shown in formula (II): Formula (II), Among them, R 2 Including one of methyl and ethyl, R 3 It includes one of a methylene group, a secondary amine group, and an amine ester group, wherein m is 1 or 3, and n is 1, 2 or 3.

5. The antibacterial coating according to claim 4, characterized in that: The zwitterionic sulfobetaine silane includes at least one of N,N-dimethylaminoethylcarbamate propyltriethoxysilane sulfonic acid inner salt, N,N-dimethylaminopropylaminomethyltriethoxysilane sulfonic acid inner salt, and 3-[dimethyl(3-(trimethoxysilyl)propylamino)]propane-1-sulfonate.

6. The antibacterial coating according to claim 1, characterized in that: The solid content of the silica sol is 30%-50%; and / or, The pH of the silica sol is 8-10; and / or, The particle size D of the silica sol V 50 is 10nm-100nm.

7. The antibacterial coating according to claim 1, characterized in that: The polysiloxane includes at least one of polydimethylsiloxane, polymethylphenylsiloxane, polyether-modified polysiloxane, alkyl-modified polysiloxane, fluorine-modified polysiloxane, epoxy-modified polysiloxane and amino-modified polysiloxane.

8. The antibacterial coating according to claim 1, characterized in that: The auxiliary solvent includes at least one of an alcohol solvent and an ether solvent.

9. The antibacterial coating according to claim 8, characterized in that: The co-solvent includes at least one of methanol, ethanol, isopropanol, propylene glycol methyl ether, and ethylene glycol butyl ether.

10. The antibacterial coating according to claim 1, characterized in that: The acid catalyst includes at least one of formic acid, acetic acid, p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, and nitric acid.

11. The antibacterial coating according to any one of claims 1 to 10, characterized in that: The antimicrobial coating further comprises a pigment dispersion, which comprises a pigment, a dispersant, a defoaming agent, a pH adjuster, a thickener and water.

12. The antimicrobial coating according to claim 11, characterized in that: The pigment comprises at least one of copper chrome black, iron manganese black, titanium dioxide, cobalt blue, cobalt green, cobalt black, titanium chrome brown, iron oxide red, iron oxide yellow, bismuth vanadate, and nickel titanium yellow; and / or, The dispersant comprises at least one of BYK-191 and DISPERBYK-101N; and / or, The defoaming agent comprises at least one of BYK1709, BYK088 and BYK024; and / or, The pH adjuster includes at least one of hydrochloric acid, acetic acid, sodium hydroxide and sodium bicarbonate; and / or, The thickener includes at least one of bentonite, fumed silica and BYK410.

13. An antibacterial cookware, characterized in that: include: Pot body; An antibacterial coating, the antibacterial coating being disposed on the inner surface of at least a portion of the pot body, the antibacterial coating comprising an antibacterial surface layer, the antibacterial surface layer being formed by the antibacterial coating according to any one of claims 1 to 12, the antibacterial surface layer comprising antibacterial segments and siloxane groups, and the interior of the antibacterial coating and / or at least a portion of the surface away from the pot body having low surface energy segments; Wherein, the antibacterial segment is grafted and connected to the low surface energy segment through the siloxane group; The structural formula of the chain segment formed by the antibacterial chain segment, the siloxane group and the low surface energy chain segment is shown in formula (III): Formula (III), Among them, R 1 Including one of hydrogen, amino, mercapto, glycidyloxy, chloro, R 3 It includes one of a methylene group, a secondary amine group, and an amine ester group, wherein m is 1 or 3, and n is 1, 2 or 3.

14. The antibacterial cookware according to claim 13, characterized in that: The antimicrobial coating further comprises: A non-stick bottom layer, the non-stick bottom layer is arranged between the antibacterial surface layer and the inner surface of the pot body; Wherein, at least part of the surface of the antibacterial surface layer comprises the antibacterial segment, and the antibacterial segment comprises a zwitterionic sulfobetaine silane segment.

15. The antibacterial cookware according to claim 14, characterized in that: The low surface energy segments include: A first low surface energy segment, wherein the first low surface energy segment is disposed on a surface of the non-stick bottom layer facing the antibacterial surface layer; A second low surface energy segment, wherein the second low surface energy segment is disposed on a surface of the antibacterial surface layer facing the non-stick bottom layer; Wherein, the second low surface energy segment is grafted and connected to the first low surface energy segment through the siloxane group.

16. The antibacterial cookware according to claim 13, characterized in that: The low surface energy segment has a polysiloxane group, and the polysiloxane group includes at least one of polydimethylsiloxane, polymethylphenylsiloxane, polyether-modified polysiloxane, alkyl-modified polysiloxane, fluorine-modified polysiloxane, epoxy-modified polysiloxane, and amino-modified polysiloxane.

17. The antibacterial cookware according to claim 14, wherein the non-stick bottom layer comprises the following raw materials in mass fractions: 20%-30% siloxane, 18%-27% silica sol, 1%-5% polysiloxane, 1%-10% co-solvent, and the balance is water.

18. The antibacterial cookware according to claim 14, characterized in that: The thickness of the non-stick bottom layer is 15 μm-25 μm, and the thickness of the antibacterial surface layer is 5 μm-15 μm.

19. The antibacterial cookware according to claim 13, characterized in that: The surface hardness of the antibacterial coating is 6H-9H.

20. The antibacterial cookware according to any one of claims 13 to 18, characterized in that: The pot body is a metal pot body, and the pot body includes a pot side wall and a pot bottom surface that is concave on the inner surface, wherein the inner surface of the pot side wall and / or the pot bottom surface is provided with the antibacterial coating, and at least part of the surface of the antibacterial coating forms a plurality of protrusions.

21. A method for preparing an antibacterial cookware, characterized in that: include: Providing a pot body; Applying the antibacterial coating according to any one of claims 1 to 12 on the inner surface of at least a portion of the pot body; The antibacterial cookware can be obtained by drying the pot body coated with the antibacterial coating at 120° C.-170° C. for 3 min-10 min, and then curing at 250° C.-300° C. for 10 min-25 min.

22. The method for preparing the antibacterial cookware according to claim 21, characterized in that: The pot body provided comprises: The surface of the pot body is cleaned, degreased and / or sandblasted, and then the pot body is heated to 40° C.-50° C.

23. The method for preparing the antibacterial cookware according to claim 21, characterized in that: The step of applying the antibacterial coating according to any one of claims 1 to 12 on the inner surface of at least a portion of the pot body comprises: A non-stick coating is provided, wherein the non-stick coating comprises the following raw materials in mass fractions: 20%-30% siloxane, 18%-27% silica sol, 1%-5% polysiloxane, 1%-10% cosolvent, and the balance is water; The non-stick coating is applied on at least a portion of the inner surface of the pot body, the pot body coated with the non-stick coating is dried at 120° C.-170° C. for 3 min-10 min, and then cured at 250° C.-300° C. for 10 min-25 min to obtain a non-stick bottom layer; The antimicrobial coating is coated on at least a portion of the surface of the non-stick base layer.

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