Quaternary ammonium salt-based self-repairing antibacterial antifouling coating as well as preparation method and application thereof

Abstract

The invention discloses a self-repairing antibacterial antifouling coating based on quaternary ammonium salt as well as a preparation method and application of the self-repairing antibacterial antifouling coating. According to the invention, a reactive polyhydroxy quaternary ammonium salt antibacterial group is introduced into an organosilicon polymer main chain, so that the antibacterial and antifouling properties of the coating are remarkably improved, and under the synergistic effect of the antibacterial group and low surface energy, the highest sterilization rate on escherichia coli can reach 100%. Besides, reversible covalent bonds and multiple hydrogen bonds are introduced, so that the coating is endowed with excellent self-repairing capability, the problem that the performance of the coating is reduced due to physical wear, chemical erosion and biological adhesion is solved, and the service life of the coating is prolonged. The coating prepared by the invention has excellent antifouling and antibacterial properties, is environment-friendly, has higher self-healing ability, and is suitable for being applied to the fields of building material protection, life health, medical instruments and the like.

Description

Technical Field

[0001] The present invention relates to the field of coatings, and particularly to a self-healing antibacterial and antifouling coating based on quaternary ammonium salts, and its preparation method and application. Background Art

[0002] With the continuous progress of science and technology and the enhancement of environmental protection awareness, the development of green and environmentally friendly coating materials with special functions has become a global focus. Traditional coating materials are easily affected by various physical abrasions, chemical erosions, and biological attachments during processing and practical applications, resulting in a decline in coating performance and a shortened service life.

[0003] The anti-fouling, antibacterial, and self-healing capabilities of coating materials are particularly important. At present, although antibacterial and antifouling coatings on the market have improved the anti-fouling and antibacterial properties of materials to a certain extent, there are still significant limitations. For example, the surface performance of some coatings will significantly decline after physical abrasion, and the anti-fouling and antibacterial effects will be greatly reduced. In addition, the preparation process of traditional coating materials often involves a large amount of harmful chemicals, causing environmental pollution and not conforming to the concept of green development. Therefore, it is of great significance to develop a green and environmentally friendly self-healing antibacterial and antifouling coating. By simulating the self-healing mechanism and molecular structure in nature, introducing monomers or polymers with antibacterial and self-healing functions, and combining advanced coating preparation technologies, coating materials with excellent antibacterial, antifouling, and self-healing properties can be prepared. After being physically abraded, these coating materials can automatically repair the damaged area and restore their original antibacterial and antifouling properties. The research and development of self-healing antibacterial and antifouling coatings will provide strong support for the development of medical, navigation, construction and other fields. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings and deficiencies of the existing solutions, and provide a self-healing antibacterial and antifouling coating based on quaternary ammonium salts, its preparation method and application, and an organosilicon polyurethane coating based on quaternary ammonium salts with antibacterial and antifouling properties and self-healing functions, and its preparation method.

[0005] The solution of the present invention includes the following steps:

[0006] (1) Take 10 - 1000 parts by weight of a di-end-group reactive polydimethylsiloxane, 1 - 500 parts by weight of a polyisocyanate, 10 - 1000 parts of a solvent α, 1 - 500 parts by weight of a polyhydroxy quaternary ammonium salt compound, and 1 - 10 parts by weight of a catalyst, and form a quaternary ammonium salt-modified organosilicon polyurethane prepolymer under an inert atmosphere and heating conditions of 70 - 90°C for 2 - 4 hours.

[0007] (2) Dissolve 1 - 1000 parts by weight of the cross - linker which is a mixture of polyol and polyamine in 1 - 500 parts by weight of solvent β, and add it to the quaternary ammonium salt - modified organosilicon polyurethane prepolymer. Under an inert atmosphere, continue the reaction for 2 - 4 hours under the conditions of heating and stirring at 70 - 90 °C to obtain a quaternary ammonium salt - based self - healing antibacterial and antifouling coating.

[0008] In the present invention, the polyhydroxy quaternary ammonium salt compound refers to: a composition of one or more of dodecyl methyl dihydroxyethyl ammonium bromide, tetradecyl methyl dihydroxyethyl ammonium bromide, N,N'-(((2 - ((3 - (dimethyl(tetradecyl)ammonium)-2 - hydroxypropoxy)methyl)propane - 1,3 - diyl)bis(oxy))bis(2 - hydroxypropane - 3,1 - diyl))bis(N,N - dimethyltetradecane - 1 - ammonium).

[0009] In the present invention, the weight - average molecular weight of the double - end - group reactive polydimethylsiloxane is 2000 - 20000, and the double - end - groups in its molecular formula refer to one or more of hydroxypropyl, aminopropyl, and mercaptopropyl.

[0010] In the present invention, the polyisocyanate is a diisocyanate or a triisocyanate, specifically referring to: one or more of diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and triphenylmethane triisocyanate.

[0011] In the present invention, the polyol specifically refers to: one of 2,2'-bipyridine - 4,4'-dimethanol and 2,2’ - dithioglycol; the polyamine specifically refers to: one of 4,4’ - dithiobis - aniline and 2,2'-diaminodiphenyl disulfide.

[0012] In the present invention, the catalyst is one or a combination of bismuth acetate and stannous octoate.

[0013] In the present invention, the solvent α refers to: one or more of tetrahydrofuran, acetone, chloroform, N,N - dimethylacetamide, and xylene; the solvent β refers to: one or more of methanol, water, tetrahydrofuran, acetone, and N,N - dimethylformamide.

[0014] In the present invention, the inert atmosphere refers to: one of argon and helium or a mixed gas.

[0015] Furthermore, spray the antifouling coating evenly on the surface of the substrate to be sprayed in an air - spraying manner, and the coating thickness in the non - dried state is 50 - 2000 μm; dry it under the conditions of room temperature with ventilation and drying to obtain a dried coating.

[0016] Furthermore, the quaternary ammonium salt-based organosilicon polyurethane coating prepared by the above process has antibacterial, antifouling, and self-healing functions, and has applications in the fields of building material protection, life and health, and medical devices.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] In the present invention, a reactive polyhydroxy quaternary ammonium salt antibacterial group is introduced into the polymer main chain, significantly improving the antibacterial and antifouling properties of the coating. Under the synergistic action of the antibacterial group and the low surface energy of organosilicon, the bactericidal rate against Escherichia coli can reach up to 100%; and by introducing dynamic covalent bonds and multiple hydrogen bonds, the coating is endowed with excellent self-healing ability, and the repair efficiency can reach 98.2%. The prepared organosilicon antifouling and antibacterial coating has excellent antifouling and antibacterial properties, is environmentally friendly, and the coating has a high self-healing ability, and is suitable for applications in the fields of building material protection, life and health, medical devices, etc. Description of the Drawings

[0019] Figure 1 It is a representative molecular structure diagram of Example 3 of the present invention. Detailed Embodiments

[0020] The following further describes the present invention in detail with specific embodiments. The embodiments can enable professionals in the field to more comprehensively understand the present invention.

[0021] The present invention discloses a self-healing antibacterial and antifouling coating based on quaternary ammonium salt and a preparation method thereof. In the present invention, a reactive polyhydroxy quaternary ammonium salt antibacterial group is introduced into the main chain of the organosilicon polymer, significantly improving the antibacterial and antifouling properties of the coating. Under the synergistic action of the antibacterial group and the low surface energy, the bactericidal rate against Escherichia coli can reach up to 100%. In addition, the present invention endows the coating with excellent self-healing ability by introducing reversible covalent bonds and multiple hydrogen bonds, overcomes the problem of the decline in coating performance caused by physical wear, chemical erosion, and biological adhesion, and prolongs the service life of the coating. The coating prepared by the present invention has excellent antifouling and antibacterial properties, is environmentally friendly, and the coating has a high self-healing ability, and is suitable for applications in the fields of building material protection, life and health, medical devices, etc.

[0022] Example 1:

[0023] The preparation and use methods of the self-healing antibacterial and antifouling coating based on quaternary ammonium salt involved in this example are as follows:

[0024] (1) Take 500 parts by weight of a dihydroxypropyl-terminated reactive polydimethylsiloxane with a weight average molecular weight of 1000, 500 parts by weight of isophorone diisocyanate, 500 parts by weight of N,N-dimethylacetamide, 500 parts by weight of dodecylmethyldiethanolammonium bromide, and 1 part by weight of bismuth acetate. Under an argon atmosphere and heating at 70 °C for 3 hours, a quaternary ammonium salt-modified organosilicon polyurethane prepolymer is formed;

[0025] (2) Dissolve a crosslinking agent composed of 100 parts by weight of 4,4'-dithiobenzidine and 100 parts by weight of 2,2'-dithiodiethanol in 100 parts by weight of N,N-dimethylacetamide, and add it to the quaternary ammonium salt-modified organosilicon polyurethane prepolymer. Under an argon atmosphere, continue to react for 2 hours under the conditions of heating at 70 °C and stirring to obtain a quaternary ammonium salt-based self-healing antibacterial and antifouling coating.

[0026] (3) Regarding the usage method of the quaternary ammonium salt-based self-healing antibacterial and antifouling coating, the antifouling coating is evenly applied to the surface of the substrate to be sprayed by air spraying, and the coating thickness before drying is 100 μm; it is dried under the conditions of ventilation and drying at room temperature to obtain a dried coating.

[0027] Example 2:

[0028] (1) Take 1000 parts by weight of a dihydroxypropyl-terminated reactive polydimethylsiloxane with a weight average molecular weight of 2000, 500 parts by weight of isophorone diisocyanate, 500 parts by weight of N,N-dimethylacetamide, 500 parts by weight of dodecylmethyldiethanolammonium bromide, and 1 part by weight of bismuth acetate. Under an argon atmosphere and heating at 70 °C for 3 hours, a quaternary ammonium salt-modified organosilicon polyurethane prepolymer is formed;

[0029] (2) Dissolve a crosslinking agent composed of 200 parts by weight of 4,4'-dithiobenzidine and 200 parts by weight of 2,2'-bipyridine-4,4'-dimethanol in 100 parts by weight of N,N-dimethylacetamide, and add it to the quaternary ammonium salt-modified organosilicon polyurethane prepolymer. Under an argon atmosphere, continue to react for 2 hours under the conditions of heating at 70 °C and stirring to obtain a quaternary ammonium salt-based self-healing antibacterial and antifouling coating.

[0030] (3) Regarding the usage method of the quaternary ammonium salt-based self-healing antibacterial and antifouling coating, the antifouling coating is evenly applied to the surface of the substrate to be sprayed by air spraying, and the coating thickness before drying is 200 μm; it is dried under the conditions of ventilation and drying at room temperature to obtain a dried coating.

[0031] Example 3:

[0032] (1) Take 1000 parts by weight of mercaptopropyl-reactive polydimethylsiloxane with a weight average molecular weight of 2000, 500 parts by weight of isophorone diisocyanate, 500 parts by weight of N,N-dimethylacetamide, 800 parts by weight of tetradecylmethyldihydroxyethylammonium bromide, and 1 part by weight of bismuth acetate. Under an argon atmosphere and heating at 70 °C for 3 hours, a quaternary ammonium salt-modified organosilicon polyurethane prepolymer is formed;

[0033] (2) Dissolve a crosslinking agent obtained by mixing 250 parts by weight of 4,4'-dithiobenzidine and 250 parts by weight of 2,2'-bipyridine-4,4'-dimethanol in 1 - 50 parts by weight of N,N-dimethylacetamide, and add it to the quaternary ammonium salt-modified organosilicon polyurethane prepolymer. Under an argon atmosphere, continue to react for 2 hours under the conditions of heating and stirring at 70 °C to obtain a quaternary ammonium salt-based self-healing antibacterial and antifouling coating.

[0034] (3) For the usage method of the quaternary ammonium salt-based self-healing antibacterial and antifouling coating, the antifouling coating is evenly applied to the surface of the substrate to be sprayed by air spraying, and the coating thickness before drying is 200 μm; it is dried under the conditions of ventilation and drying at room temperature to obtain a dried coating.

[0035] Example 4:

[0036] (1) Take 1000 parts by weight of mercaptopropyl-reactive polydimethylsiloxane with a weight average molecular weight of 1000, 500 parts by weight of isophorone diisocyanate, 500 parts by weight of N,N-dimethylacetamide, 1000 parts by weight of tetradecylmethyldihydroxyethylammonium bromide, and 1 part by weight of bismuth acetate. Under an argon atmosphere and heating at 70 °C for 3 hours, a quaternary ammonium salt-modified organosilicon polyurethane prepolymer is formed;

[0037] (2) Dissolve a crosslinking agent obtained by mixing 300 parts by weight of 4,4'-dithiobenzidine and 300 parts by weight of 2,2'-bipyridine-4,4'-dimethanol in 200 parts by weight of N,N-dimethylacetamide, and add it to the quaternary ammonium salt-modified organosilicon polyurethane prepolymer. Under an argon atmosphere, continue to react for 2 hours under the conditions of heating and stirring at 70 °C to obtain a quaternary ammonium salt-based self-healing antibacterial and antifouling coating.

[0038] (3) For the usage method of the quaternary ammonium salt-based self-healing antibacterial and antifouling coating, the antifouling coating is evenly applied to the surface of the substrate to be sprayed by air spraying, and the coating thickness before drying is 500 μm; it is dried under the conditions of ventilation and drying at room temperature to obtain a dried coating.

[0039] Example 5:

[0040] (1) Take 1000 parts by weight of mercaptopropyl-reactive polydimethylsiloxane with a weight average molecular weight of 2000, 500 parts by weight of isophorone diisocyanate, 500 parts by weight of N,N-dimethylacetamide, 800 parts by weight of tetradecylmethyldihydroxyethylammonium bromide, N,N'-(((2-((3-(dimethyl(tetradecyl)ammonio)-2-hydroxypropoxy)methyl)propane-1,3-diyl)bis(oxy))bis(2-hydroxypropane-3,1-diyl))bis(N,N-dimethyltetradecane-1-ammonium), and 1 part by weight of bismuth acetate. Under an argon atmosphere and heating at 70 °C for 3 hours, a quaternary ammonium salt-modified organosilicon polyurethane prepolymer is formed;

[0041] (2) Dissolve a crosslinking agent prepared by mixing 300 parts by weight of 4,4'-dithiobis(aniline) and 300 parts by weight of 2,2'-bipyridine-4,4'-dimethanol in 1000 parts by weight of N,N-dimethylacetamide, and add it to the quaternary ammonium salt-modified organosilicon polyurethane prepolymer. Under an argon atmosphere, continue to react for 2 hours under the conditions of heating and stirring at 70 °C to obtain a quaternary ammonium salt-based self-healing antibacterial and antifouling coating.

[0042] (3) Regarding the usage method of the quaternary ammonium salt-based self-healing antibacterial and antifouling coating, the antifouling coating is evenly applied to the surface of the substrate to be sprayed by air spraying, and the coating thickness in the undried state is 1000 μm; it is dried under the conditions of ventilation and drying at room temperature to obtain a dried coating.

[0043] Comparative Example 1:

[0044] (1) Take 500 parts by weight of dihydroxypropyl-terminated reactive polydimethylsiloxane with a weight average molecular weight of 1000, 500 parts by weight of isophorone diisocyanate, 500 parts by weight of N,N-dimethylacetamide, and 1 part by weight of bismuth acetate. Under an argon atmosphere and heating at 70 °C for 3 hours, an organosilicon polyurethane prepolymer is formed;

[0045] (2) Dissolve a crosslinking agent prepared by mixing 100 parts by weight of 4,4'-dithiobis(aniline) and 100 parts by weight of 2,2'-dithiodiethanol in 100 parts by weight of N,N-dimethylacetamide, and add it to the quaternary ammonium salt-modified organosilicon polyurethane prepolymer. Under an argon atmosphere, continue to react for 2 hours under the conditions of heating and stirring at 70 °C to obtain a self-healing coating.

[0046] (3) Apply the coating evenly to the surface of the substrate to be sprayed by air spraying, and the coating thickness in the undried state is 100 μm; it is dried under the conditions of ventilation and drying at room temperature to obtain a dried coating.

[0047] Comparative Example 2:

[0048] (1) Take 500 parts by weight of a dihydroxypropyl-terminated reactive polydimethylsiloxane with a weight average molecular weight of 1000, 500 parts by weight of isophorone diisocyanate, 500 parts by weight of N,N-dimethylacetamide, 500 parts by weight of dodecylmethyldiethanolammonium bromide, and 1 part by weight of bismuth acetate. Under an argon atmosphere and heating at 70 °C for 3 hours, a quaternary ammonium salt-modified organosilicon polyurethane prepolymer is formed;

[0049] (2) Dissolve a crosslinking agent composed of 100 parts by weight of 1,4-butanediamine and 100 parts by weight of 1,4-butanediol in 100 parts by weight of N,N-dimethylacetamide, and add it to the quaternary ammonium salt-modified organosilicon polyurethane prepolymer. Under an argon atmosphere, continue to react for 2 hours under the conditions of heating and stirring at 70 °C to obtain a quaternary ammonium salt antibacterial and antifouling coating.

[0050] (3) Uniformly coat the coating on the surface of the substrate to be sprayed by air spraying. The coating thickness before drying is 100 μm; dry it under the conditions of ventilation and drying at room temperature to obtain a dry coating.

[0051] Performance test and evaluation results:

[0052] Test method for static water contact angle: At room temperature, use an optical contact angle tester (CAM 200, KSV, Finland) to measure the contact angle of the coating with a 3 μL liquid droplet. The average value is obtained by measuring at least 5 different random positions on the coating. Using the above test and calculation methods, the data of each example are listed in Table 1.

[0053] The preparation method of the self-healing efficiency test sample is to dissolve the coating material in a solvent. Subsequently, pour it into a mold, and after evaporating overnight, further dry the obtained sample in a vacuum oven at 50 °C for 24 hours, and cut it into dumbbell-shaped specimens with dimensions of 20×2.5×1 mm 3 Connect the specimens by cutting them into two pieces and bringing them into contact with each other. Conduct repair in air at room temperature. Mechanical tensile stress tests are carried out before and after repair to evaluate the self-healing efficiency of the coating. Use a universal testing machine to test the stress-strain curve of the dumbbell-shaped sample. The universal material testing machine is Zwick / Roell Z020 of Zwick Company in Germany, and the tensile rate is 10 mm / min. The repair efficiency (RE) is defined as the ratio of the maximum tensile strength (US) before and after repair:

[0054]

[0055] Antibacterial rate test method: Expose the prepared coating sample to 5 mL of Escherichia coli culture solution with an OD value of 1 (concentration is about 10 9 CFU / mL, at this time the bacterial growth rate is the fastest). After culturing at 37 °C for 3 h, dilute it step by step, and take 10-6 , 10 -5 , 10 -4 , 10 -3 20 μL of each gradient bacterial solution was respectively coated on a solid plate medium and cultured at 37 °C for 24 h. Viable cell counting was performed on the plates with about 10 - 100 colonies to obtain the viable cell concentration after contact (i.e., the number of colony formations, CFU / mL, which is proportional to the original bacterial count).

[0056] The antibacterial rate was calculated according to the following formula:

[0057] Antibacterial rate (%) = (Original bacterial count - Viable bacterial count) / Original bacterial count × 100%

[0058] Using the above test and calculation methods, the data of each example and comparative example are listed in Table 1.

[0059] Table 1

[0060]

[0061] The parts not involved in the present invention are the same as the prior art or are implemented using the prior art.

[0062] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent transformation made using the content of the specification and drawings of the present invention, or directly or indirectly applied in related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A method for preparing a self-repairing antibacterial and antifouling coating based on quaternary ammonium salt, characterized in that: The following steps are involved: (1) taking 10-1000 parts by weight of a dual-end reactive polydimethylsiloxane, 1-500 parts by weight of a polyisocyanate, 10-1000 parts by weight of a solvent α, 1-500 parts by weight of a polyhydroxy quaternary ammonium salt compound, and 1-10 parts by weight of a catalyst, and heating the mixture under an inert atmosphere at 70-90° C. for 2-4 hours to form a quaternary ammonium salt-modified silicone polyurethane prepolymer; (2) 1-1000 parts by weight of a crosslinking agent mixed with a polyol and a polyamine is dissolved in 1-500 parts by weight of a beta solvent, and added to a quaternary ammonium salt-modified silicone polyurethane prepolymer, and the reaction is continued for 2-4 hours under an inert atmosphere at 70-90° C. under heating and stirring conditions to obtain a quaternary ammonium salt-based self-healing antibacterial and antifouling coating.

2. The method for preparing a self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 1, characterized in that: The polyhydroxy quaternary ammonium salt compound refers to a combination of one or more of dodecylmethyl dihydroxyethyl ammonium bromide, tetradecylmethyl dihydroxyethyl ammonium bromide, N,N'-(((2-((3-(dimethyl(tetradecyl)ammonium)-2-hydroxypropoxy)methyl)propane-1,3-diyl)bis(oxy))bis(2-hydroxypropane-3,1-diyl))bis(N,N-dimethyltetradec-1-ammonium).

3. The method for preparing the self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 2, characterized in that: The weight average molecular weight of the dual-terminal reactive polydimethylsiloxane is 2000-20000, and the dual-terminal groups in the molecular formula refer to one or more of hydroxypropyl, aminopropyl, and mercaptopropyl.

4. The method for preparing the self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 3, characterized in that: The polyisocyanate is a diisocyanate or a triisocyanate, specifically one or more of diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and triphenylmethane triisocyanate.

5. The method for preparing the self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 4, characterized in that: The polyol specifically refers to one of 2,2'-bipyridine-4,4'-dimethanol and 2,2'-dithiodiethanol; the polyamine specifically refers to one of 4,4'-dithiodiphenylamine and 2,2'-diaminodiphenyl disulfide.

6. The method for preparing the self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 5, characterized in that: The catalyst is one or a combination of bismuth acetate and stannous octoate.

7. The method for preparing the self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 6, characterized in that: The solvent α refers to one or more of tetrahydrofuran, acetone, chloroform, N,N-dimethylacetamide, and xylene; the solvent β refers to one or more of methanol, water, tetrahydrofuran, acetone, and N,N-dimethylformamide.

8. The method for preparing the self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 7, characterized in that: The inert atmosphere refers to: one or a mixture of argon and helium.

9. The method for preparing the self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 8, characterized in that: The prepared antifouling coating is evenly coated on the surface of the substrate to be sprayed by air spraying, and the coating thickness is 50-2000 μm in the undried state; and the coating is dried under ventilated and dry room temperature conditions to obtain a dry coating.

10. The method for preparing the self-repairing antibacterial and antifouling coating based on quaternary ammonium salt according to claim 8, characterized in that: The prepared antifouling coating has antibacterial, antifouling and self-repairing functions, and is applicable in the fields of building material protection, life health, and medical equipment.

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