Preparation method of conductive, antibacterial, corrosion-resistant and aging-resistant multifunctional coating

Abstract

The invention relates to the technical field of conductive functional coatings, and discloses a preparation method of a conductive antibacterial anti-corrosion anti-aging coating. According to the method disclosed by the invention, the silane coupling agent and the conductive filler are modified and then are co-hydrolyzed with the organic metal salt, so that the high-performance coating formed by bridging the conductive filler and the nanoparticles by an organic polymer chain is prepared, and the selected long-chain organic silicon modified silane coupling agent is used for improving the toughness and hydrophobicity of the coating; the adhesion and corrosion resistance of the coating are improved by introducing epoxy and dopamine structures, the aging resistance is improved by the nano particle effect of nano silicon dioxide and metal oxide, and the coating is endowed with conductivity by the conductive filler. The coating integrating multiple functions is prepared through co-hydrolysis of the organic silicon, the organic metal salt and the modified conductive filler, the defect that multiple functions of an existing coating cannot be considered at the same time is overcome, and the coating has important significance for widening the practical application of the coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of coating preparation, and particularly relates to a preparation method of a multifunctional coating with electrical conductivity, antibacterial property, anti-corrosion property and anti-aging property. Background Art

[0002] With the rapid development of aerospace and aviation, the coating on the body surface not only protects the internal materials from the influence of the external environment, but also makes it safe, beautiful, clean and adaptable to various complex environments. Currently, the prepared coatings mainly include organic coatings and organic-inorganic composite coatings. To achieve the target functions of the coatings such as electrical conductivity, hydrophobicity, anti-icing property, high temperature resistance, anti-aging property, adhesion and salt spray resistance, etc., not only need to go through cumbersome steps, but also the obtained coatings are often difficult to have the above functions at the same time. Therefore, how to simply and efficiently design a coating integrating multiple functions has become the focus and hotspot of research.

[0003] Organic coatings have good flexibility and chemical stability, but poor heat resistance and anti-aging property; for the coatings prepared by organic-inorganic composite, although the electrical conductivity, heat resistance and anti-aging property of the materials are improved, the uniform distribution of the fillers and the interaction between the fillers and the polymer are difficult to control. At the same time, different structural designs, chemical modifications and other cumbersome steps are required for the fillers to achieve specific functions. Therefore, there is an urgent need for a simple and efficient method to prepare high-performance coatings. The sol-gel method can transform organic components into inorganic components through hydrolysis and condensation reactions, which plays an important role in improving the heat resistance and anti-aging property of materials; by regulating the formula and controlling the size of the final nanoparticles, the multifunctionality of the final materials such as hydrophilicity / hydrophobicity, adhesion, toughness, weather resistance, corrosion resistance and anti-aging property can be realized by using the surface and interface effects, small size effects, quantum size effects and macroscopic quantum tunneling effects of the nanoparticles. At the same time, after introducing conductive fillers, it endows the coating with electrical conductivity. Summary of the Invention

[0004] In view of this, in order to overcome the above problems in the prior art, the purpose of the present invention is to provide a preparation method of a multifunctional coating with electrical conductivity, antibacterial property, anti-corrosion property and anti-aging property.

[0005] To achieve the above purpose, the present invention provides the following technical solutions.

[0006] A preparation method of a conductive antibacterial anti-corrosion anti-aging coating, which comprises the following steps:

[0007] S1: Preparation of a modified silane coupling agent

[0008] S1.1 Add the monomer containing epoxy functional groups and the silane coupling agent into an organic solvent, and react in the presence of an organic base catalyst to obtain an epoxy-modified silane coupling agent, wherein the molar ratio of the epoxy functional groups to the amino group or mercapto group in the silane coupling agent is (7 - 5):(3 - 5); the mass ratio of the monomer containing epoxy polyfunctional groups to the organic solvent is 0.1 - 0.3, and the mass ratio of the organic base catalyst to the monomer containing epoxy polyfunctional groups is 0.001:1;

[0009] S1.2 Mix the organosilicon containing diamine and the silane coupling agent with epoxy groups in a molar ratio of (1 - 2):(2 - 1), and react in the presence of an organic base catalyst to obtain a long-chain organosilicon-modified silane coupling agent;

[0010] S1.3 Mix dopamine and the silane coupling agent with epoxy groups in a molar ratio of (7 - 5):(3 - 5), and react in the presence of an organic base catalyst to obtain a silane coupling agent with catechol;

[0011] S2: Preparation of modified conductive filler

[0012] Functionalize the surface of the conductive filler so that its surface has any one of amino group, carboxyl group, hydroxyl group or epoxy group, and then react the functional groups on the surface of the conductive filler with the silane coupling agent with corresponding reactive functional groups to prepare a modified conductive filler with Si - O - R groups on the surface;

[0013] S3: Preparation of conductive antibacterial, anticorrosive and aging-resistant coating

[0014] Add the epoxy-modified silane coupling agent, long-chain organosilicon-modified silane coupling agent, silane coupling agent with catechol obtained in step S1, the modified conductive filler obtained in step S2, the silane coupling agent with fluorine chain and the organic metal salt into a mixed solvent in a mass ratio of (5 - 9):(0.5 - 1):(0.1 - 1):(1 - 2):(0.1 - 3):(0 - 5), and react for a certain time under the action of a catalyst to carry out co-hydrolysis to obtain a sol, and coat it on the surface of the substrate to prepare a conductive antibacterial, anticorrosive and aging-resistant coating.

[0015] Furthermore, the organic solvent is any one or a combination of N,N-dimethylformamide, N,N-dimethylacetamide, dichloromethane, chloroform, tetrahydrofuran, dioxane, pyridine and toluene.

[0016] Furthermore, the organic base catalyst is triethylamine, ethylenediamine, tetramethylammonium hydroxide or tetraethylammonium hydroxide

[0017] Further, the monomer containing an epoxy functional group is any one or a combination of diglycidyl 4,5-epoxytetrahydrophthalate, triglycidyl p-aminophenol ether, triglycidylamine epoxy resin, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, isocyanuric acid triglycidyl ester, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, pentaerythritol glycidyl ether, and trimethylolpropane glycidyl ether.

[0018] Further, the silane coupling agent is any one or a combination of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2,3-epoxypropoxypropyl)trimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, methyl orthosilicate, ethyl orthosilicate, and propyl orthosilicate.

[0019] Further, the organosilicon containing diamine is any one or a combination of 1,3-bis(3-aminopropyl)tetramethyldisiloxane and bis(3-aminopropyl) terminated poly(dimethylsiloxane) with different molecular weights. The silane coupling agent containing an epoxy group is any one or a combination of 3-glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0020] Further, the silane coupling agent with a fluorine chain is any one or a combination of heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltriethoxysilane, tridecafluorooctyltrimethoxysilane, and tridecafluorooctyltriethoxysilane.

[0021] Further, the conductive filler is any one or a combination of carbon nanotubes, graphene, carbon black, MXene, and nanosilver wires.

[0022] Further, the organometallic salt is any one or a combination of tetrabutyl titanate, tetrabutyl zirconate, zinc acetylacetonate, zinc ethyl acetoacetate, magnesium acetylacetonate, and aluminum acetylacetonate.

[0023] Further, the mixed solvent is a mixture of water and any one or a combination of N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, methanol, ethanol, isopropanol, ethylene glycol, n-butanol, acetone, and methyl ethyl ketone. Preferably, water accounts for 5% to 20% in the mixed solvent.

[0024] Further, the catalyst described in step S3 is an inorganic acid, an organic acid, an organic base or an inorganic base; the inorganic acid is trifluoroacetic acid, hydrochloric acid or sulfuric acid, the organic acid is glacial acetic acid or p-toluenesulfonic acid, the organic base is triethylamine, ethylenediamine, tetramethylammonium hydroxide or tetraethylammonium hydroxide, and the inorganic base is sodium hydroxide or potassium hydroxide.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The present invention realizes the preparation of an organic-inorganic hybrid conductive coating through the modification of silane coupling agent and conductive filler and their co-hydrolysis with organic metal salts. The whole preparation process is simple and easy for batch production.

[0027] 2) In the coating prepared by the present invention, the nanoparticles and the conductive filler are bridged together by polymer chains to form a coating with a uniform and stable structure, avoiding the deficiency of non-uniform structure of the composite coating.

[0028] 3) The size of the nanoparticles and the content of the conductive filler in the present invention are easy to control. By utilizing the differences in the properties of nanoparticles with different sizes, the coating is endowed with various functions, such as hydrophobicity, anti-icing property, high temperature resistance, anti-aging property, adhesion and salt spray resistance. After the salt spray test and anti-aging test under national standard conditions, the performance of the coating has no obvious change, and at the same time, it can maintain high conductivity. Description of the Drawings

[0029] Figure 1 Schematic diagram showing the conductive performance of the coating prepared in the embodiment of the present invention.

[0030] Figure 2 Schematic diagram showing the antibacterial performance of the coating prepared in the embodiment of the present invention.

[0031] Figure 3 Schematic diagram showing the antifouling performance of the coating prepared in the embodiment of the present invention. Detailed Embodiments

[0032] Example 1

[0033] This example provides a method for preparing a conductive antibacterial, anticorrosive and anti-aging coating, which includes the following steps:

[0034] S1: Preparation of modified silane coupling agent

[0035] S1.1 Add N,N-dimethylacetamide, p-aminophenol glycidyl ether trifunctional glycidylamine epoxy resin, 3-aminopropyltrimethoxysilane and triethylamine catalyst into a container equipped with a magnetic stirrer in sequence. Among them, the molar ratio of epoxy functional groups to amino groups in the silane coupling agent is 2:1; the mass ratio of the monomer containing epoxy functional groups to the organic solvent is 0.2; the mass ratio of the catalyst to the monomer containing epoxy polyfunctional groups is 0.001:1. After reacting at 50 °C for 12 h, an epoxy-modified silane coupling agent is obtained.

[0036] S1.2 Add acetonitrile, diglycidyl 4,5-epoxytetrahydrophthalate, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and tetramethylammonium hydroxide catalyst into a container equipped with a magnetic stirrer in sequence. Among them, the molar ratio of epoxy functional groups to amino groups in the silane coupling agent is 2:1; the mass ratio of the monomer containing epoxy functional groups to the organic solvent is 0.2; the mass ratio of the catalyst to the monomer containing epoxy polyfunctional groups is 0.001:1. After reacting at 50 °C for 12 h, an epoxy-modified silane coupling agent is obtained.

[0037] S1.3 Add tetrahydrofuran, pentaerythritol glycidyl ether, 3-mercaptopropyltriethoxysilane and sodium hydroxide catalyst into a container equipped with a magnetic stirrer in sequence. Among them, the molar ratio of epoxy functional groups to amino groups in the silane coupling agent is 2:1; the mass ratio of the monomer containing epoxy functional groups to the organic solvent is 0.2; the mass ratio of the catalyst to the monomer containing epoxy polyfunctional groups is 0.001:1. After reacting at 50 °C for 12 h, an epoxy-modified silane coupling agent is obtained.

[0038] S1.4 Mix the bis(aminopropyl)-terminated organosilicon and the epoxy-group-containing silane coupling agent in a molar ratio of (1-2):(2-1), and react in the presence of a triethylamine agent to obtain a long-chain organosilicon-modified silane coupling agent;

[0039] S1.5 Mix dopamine and the epoxy-group-containing silane coupling agent in a molar ratio of (7-5):(3-5), and react in the presence of a triethylamine catalyst to obtain a silane coupling agent with catechol;

[0040] S2: Preparation of modified conductive filler

[0041] S2.1 Aminate the surface of carbon nanotubes, and then add the surface-aminated carbon nanotubes and the epoxy-group-containing silane coupling agent into ethanol according to a mass ratio of 1:0.01, and react at 50 °C for 12 h to obtain silane-modified carbon nanotubes.

[0042] S2.2 Aminate the surface of graphene, and then add the surface - aminated carbon nanotubes and a silane coupling agent with epoxy groups into ethanol at a mass ratio of 1:0.01. React at 50 °C for 12 h to obtain silane - modified graphene.

[0043] S2.3 Aminate the surface of Mxene, and then add the surface - aminated carbon nanotubes and a silane coupling agent with epoxy groups into ethanol at a mass ratio of 1:0.03. React at 50 °C for 12 h to obtain silane - modified Mxene.

[0044] S3: Preparation of Conductive Antibacterial, Anticorrosive and Aging - Resistant Coating

[0045] Add the epoxy - modified silane coupling agent obtained in step 1, the modified conductive filler, the silane coupling agent with fluorine chains, tetrabutyl zirconate and an organic base catalyst into isopropanol at a molar ratio of 1:0.01:0.01:1:0.001 simultaneously. After reacting under magnetic stirring for 2 h, perform film coating on the obtained gel to prepare the target conductive antibacterial, anticorrosive and aging - resistant coating.

[0046] Example 2

[0047] Add the long - chain organosilicon - modified silane coupling agent obtained in step 1, the silane - modified Mxene, the silane coupling agent with fluorine chains, zinc acetylacetonate and an organic base catalyst into ethanol at a molar ratio of 1:0.01:0.01:1:0.001 simultaneously. After reacting under magnetic stirring for 2 h, perform film coating on the obtained gel to prepare the target conductive antibacterial, anticorrosive and aging - resistant coating.

[0048] Example 3

[0049] Add the catechol - modified silane coupling agent obtained in step 1, the silane - modified graphene, the silane coupling agent with fluorine chains, tetrabutyl titanate and an organic base catalyst into ethanol at a molar ratio of 1:0.01:0.01:1:0.001 simultaneously. After reacting under magnetic stirring for 2 h, perform film coating on the obtained gel to prepare the target conductive antibacterial, anticorrosive and aging - resistant coating.

[0050] Example 4

[0051] Add the long - chain organosilicon - modified silane coupling agent obtained in step 1, the silane - modified Mxene, the silane coupling agent with fluorine chains, zinc acetylacetonate and an organic base catalyst into ethanol at a molar ratio of 1:0.05:0.01:1:0.001 simultaneously. After reacting under magnetic stirring for 2 h, perform film coating on the obtained gel to prepare the target conductive antibacterial, anticorrosive and aging - resistant coating.

[0052] Example 5

[0053] The long-chain organosilicon-modified silane coupling agent, silane-modified Mxene, fluorine-chain-containing silane coupling agent, zinc acetylacetonate, and organic base catalyst obtained in Step 1 are simultaneously added to ethanol at a molar ratio of 1:0.1:0.01:1:0.001. After reacting for 2 h under magnetic stirring, the obtained gel is coated to prepare the target conductive, antibacterial, anticorrosive, and aging-resistant coating.

[0054] Example 6

[0055] The long-chain organosilicon-modified silane coupling agent, silane-modified Mxene, fluorine-chain-containing silane coupling agent, zinc acetylacetonate, and organic base catalyst obtained in Step 1 are simultaneously added to ethanol at a molar ratio of 1:0.3:0.01:1:0.001. After reacting for 2 h under magnetic stirring, the obtained gel is coated to prepare the target conductive, antibacterial, anticorrosive, and aging-resistant coating.

[0056] Example 7

[0057] The long-chain organosilicon-modified silane coupling agent, silane-modified Mxene, fluorine-chain-containing silane coupling agent, zinc acetylacetonate, and organic base catalyst obtained in Step 1 are simultaneously added to ethanol at a molar ratio of 1:0.5:0.01:1:0.001. After reacting for 2 h under magnetic stirring, the obtained gel is coated to prepare the target conductive, antibacterial, anticorrosive, and aging-resistant coating.

[0058] The conductive, antibacterial, and anticorrosive aging-resistant coatings obtained in Examples 1 to 7 are subjected to an acidic atmosphere test in accordance with GJB 150.28-2009. After the test, there is no obvious corrosion on the coating surface; tested in accordance with the neutral salt spray test of GJB 150.11A-2009, there is no corrosion on the coating surface after the test; tested in accordance with the mildew resistance test of GJB 150.10A-2009, there is no obvious mildew attachment on the coating surface after the test, which is Grade 0. After 1000 h of ultraviolet accelerated aging, the contact angle of the coating remains above 100°. When the addition amounts of the three modified conductive fillers are the same, the conductive performance of Mxene is the best; on the premise of maintaining other properties of the coating, the conductive performance of the coating increases with the increase in the addition amount of Mxene, and the highest conductivity of the coating is 3.2×10 4 S · cm -1 . The contact angle reaches up to 110°. Figures 1 to 3 The conductive, antibacterial, and antifouling properties of the coatings prepared in the embodiments of the present invention are schematically shown respectively.

[0059] The present invention adopts the sol-gel method to co-hydrolyze a modified silane coupling agent, a conductive filler and an organic metal salt, and prepares a coating that polymer chain-bridges inorganic nanoparticles of different sizes and different types as well as the conductive filler, and can simply and efficiently prepare a coating integrating multiple functions, laying a solid foundation for the preparation of coatings in subsequent different application fields.

[0060] It should be noted that the above-described embodiments are only the preferred embodiments of the present invention. For those of ordinary skill in the art, without departing from the principle of the present invention, several modifications, improvements and equivalent replacements can be made to the present invention, and these modifications, improvements and equivalent replacements are also considered to fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a conductive, antibacterial, anticorrosive and aging-resistant coating, characterized in that: The steps include: S1: Preparation of modified silane coupling agent S1.1 Adding a monomer containing an epoxy functional group and a silane coupling agent to an organic solvent, reacting in the presence of an organic base catalyst to obtain an epoxy-modified silane coupling agent, wherein the molar ratio of the epoxy functional group to the amino group or the mercapto group in the silane coupling agent is (7-5):(3-5); the mass ratio of the monomer containing an epoxy multifunctional group to the organic solvent is 0.1-0.3, and the mass ratio of the organic base catalyst to the monomer containing an epoxy multifunctional group is 0.001:1; S1.2 mixing a diamine-containing organosilicon with an epoxy-group-containing silane coupling agent in a molar ratio of (1-2):(2-1), and reacting the mixture in the presence of an organic base catalyst to obtain a long-chain organosilicon-modified silane coupling agent; S1.3 dopamine and a silane coupling agent with an epoxy group are mixed in a molar ratio of (7-5):(3-5), and reacted in the presence of an organic base catalyst to obtain a silane coupling agent with catechol; S2: Preparation of modified conductive fillers Functionalizing the surface of the conductive filler so that it has any one of amino, carboxyl, hydroxyl or epoxy groups on the surface, and then using the functional groups on the surface of the conductive filler to react with a silane coupling agent with corresponding reactive functional groups to prepare a modified conductive filler with Si-OR groups on the surface; S3: Preparation of conductive, antibacterial, anticorrosive and aging-resistant coatings The epoxy-modified silane coupling agent obtained in step S1, the long-chain silicone-modified silane coupling agent, the silane coupling agent with catechol, the modified conductive filler obtained in step S2, the silane coupling agent with a fluorine chain, and the organic metal salt are added to a mixed solvent in a mass ratio of (5-9):(0.5-1):(0.1-1):(1-2):(0.1-3):(0-5), react for a certain time under the action of a catalyst to perform co-hydrolysis to obtain a sol, and apply it to the surface of a substrate to prepare a conductive, antibacterial, anticorrosive, and aging-resistant coating.

2. The method for preparing the conductive antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: The organic solvent is any one of N,N-dimethylformamide, N,N-dimethylacetamide, dichloromethane, chloroform, tetrahydrofuran, dioxane, pyridine and toluene, or a combination thereof.

3. The method for preparing the conductive, antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: The monomer containing epoxy functional groups is any one of 4,5-epoxytetrahydrophthalic acid diglycidyl ester, p-aminophenol glycidyl ether trifunctional glycidyl amine epoxy resin, N,N,N',N'-tetraepoxypropyl-4,4'-diaminodiphenylmethane, isocyanuric acid triglycidyl ester, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, pentaerythritol glycidyl ether and hydroxymethylpropane glycidyl ether or a combination thereof.

4. The method for preparing the conductive antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: The silane coupling agent is any one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2,3-epoxypropyl)trimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltri(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropyltrimethoxysilane, methyl orthosilicate, ethyl orthosilicate and propyl orthosilicate, or a combination thereof.

5. The method for preparing the conductive antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: The diamine-containing organosilicon is any one of 1,3-bis(3-aminopropyl)tetramethyldisiloxane and bis(3-aminopropyl)-terminated poly(dimethylsiloxane) of different molecular weights or a combination thereof. The epoxy-group-containing silane coupling agent is any one of 3-glycidyloxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane or a combination thereof.

6. The method for preparing the conductive antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: The silane coupling agent with a fluorine chain is any one of heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltriethoxysilane, tridecafluorooctyltrimethoxysilane and tridecafluorooctyltriethoxysilane or a combination thereof.

7. The method for preparing the conductive antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: The conductive filler is any one of carbon nanotubes, graphene, carbon black, MXene, and nano silver wires, or a combination thereof.

8. The method for preparing the conductive antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: The organic metal salt is any one of tetrabutyl titanate, tetrabutyl zirconate, zinc acetylacetonate, ethyl zinc acetylacetonate, magnesium acetylacetonate and aluminum acetylacetonate or a combination thereof.

9. The method for preparing the conductive antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: The mixed solvent is a mixture of water and any one of N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, methanol, ethanol, isopropanol, ethylene glycol, n-butanol, acetone and butanone, or a combination thereof.

10. The method for preparing the conductive antibacterial, anticorrosive and aging-resistant coating according to claim 1, characterized in that: In step S3, the catalyst is an inorganic acid, an organic acid, an organic base or an inorganic base; the inorganic acid is trifluoroacetic acid, hydrochloric acid or sulfuric acid, the organic acid is glacial acetic acid or p-toluenesulfonic acid, the organic base is triethylamine, ethylenediamine, tetramethylammonium hydroxide or tetraethylammonium hydroxide, and the inorganic base is sodium hydroxide or potassium hydroxide.

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