A quaternized epoxy polysiloxane, cationic light-cured vegetable oil-based antifouling and antibacterial coating and preparation method thereof

Abstract

The invention discloses a quaternized epoxy polysiloxane, a cationic light-cured vegetable oil-based antifouling and antibacterial coating and a preparation method thereof, and relates to the technical field of organic silicon. The preparation method of the quaternized epoxy polysiloxane provided by the invention introduces epoxy structural fragments and quaternary ammonium salt structural fragments into the polysiloxane chain segment, so that a polymerization reaction can occur between the quaternized siloxane and the epoxy vegetable oil, and the two are used together as prepolymers in a cationic light-curing system, and can be cured to obtain a coating with both high antifouling performance and high antibacterial performance. The water contact angle of the obtained coating is above 103°, the hexadecane contact angle is above 28.1°, the antifouling performance is excellent, and the antibacterial rate reaches above 99.9%.

Description

Technical Field

[0001] The invention relates to the technical field of organic silicon, and in particular to a quaternized epoxy polysiloxane, a cationic light-cured vegetable oil-based antifouling and antibacterial coating and a preparation method thereof. Background Art

[0002] Polymers have good film-forming properties, mechanical strength, chemical and thermal stability, and corrosion and oxidation resistance, and are one of the most commonly used coating materials. However, in the fields of marine, biochemical, food, and water treatment, problems such as pollutant damage and bacterial erosion on the surface of polymer coatings need to be urgently addressed.

[0003] The common antifouling and antibacterial coatings have an antifouling and antibacterial mechanism that is mainly through the hydrophilic groups and the surrounding water molecules through hydrogen bonding to form a hydration layer structure on the coating surface, thereby preventing substances such as proteins and microorganisms from adhering to the coating surface. Existing polymer coatings are usually prepared using polyethylene glycol as a substrate, but polyethylene glycol is a petroleum-based material. Compared with biomass-based materials, petroleum-based materials are non-renewable and are not conducive to environmental protection. Therefore, it is necessary to solve the problem that the raw materials of current polymer coatings are non-renewable.

[0004] In addition, anti-fouling is achieved by forming a hydration layer, and its anti-pollution effect on oily pollutants is better, but the anti-pollution effect on water-based pollutants is poor; and the antibacterial effect is not obvious only by reducing the adhesion of microorganisms on the coating; therefore, the anti-fouling and antibacterial effects of the anti-fouling and antibacterial coating need to be further improved. Summary of the invention

[0005] In order to solve the problem that the existing coatings still have poor antifouling performance and high antibacterial performance, the present invention provides a preparation method of quaternized epoxy polysiloxane, epoxy and quaternary ammonium salt structural fragments are introduced into the polysiloxane chain segment, so that a polymerization reaction can occur between the quaternized siloxane and the vegetable oil, thereby improving the compatibility between the quaternized siloxane and the vegetable oil. The obtained quaternized epoxy polysiloxane is added to the vegetable oil system and cured to obtain a coating with both high antifouling performance and high antibacterial performance.

[0006] Another object of the present invention is to provide a quaternized epoxy polysiloxane.

[0007] Another object of the present invention is to provide a cationic light-cured vegetable oil-based antifouling and antibacterial coating.

[0008] Another object of the present invention is to provide a method for preparing a cationic light-cured vegetable oil-based antifouling and antibacterial coating.

[0009] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0010] A method for preparing quaternized epoxy polysiloxane comprises the following steps:

[0011] Hydrogen-containing silicone oil, catalyst and allyl halogenated hydrocarbon Mix well and react fully. Add vinyl epoxy monomer after the reaction is complete. Reaction, then add trialkylamine Carry out the reaction, and after the reaction is completed, quaternized epoxy polysiloxane can be obtained;

[0012] The molar ratio of active hydrogen, allyl halogenated hydrocarbon, vinyl epoxy monomer and trialkylamine in the hydrogen-containing silicone oil is (2-10):1:(1-10):(0.9-1.1);

[0013] In the allyl halogenated hydrocarbon, p=1-2, X=Cl, Br, I; in the trialkylamine, R1, R2, and R3 are each independently selected from any alkyl group;

[0014] In the vinyl epoxy monomer, R4 is CH3 and / or H, and R5 is CH2 and / or CO.

[0015] In the present invention, the hydrogen-containing silicone oil has the following structural formula:

[0016] m and n represent the number of repeating units containing no active hydrogen and the number of repeating units containing active hydrogen in the hydrogen-containing silicone oil, respectively.

[0017] The quaternized epoxy polysiloxane prepared by the present invention has a structure shown in the following formula:

[0018]

[0019] In the above formula, the value of p and the groups R1, R2, and R3 are consistent with those of the allyl halogenated hydrocarbons and trialkylamines used.

[0020] In the above formula, the R4 and R5 groups are consistent with those in the vinyl epoxy monomer used.

[0021] The ratio of i:(ni) in the above formula is actually the molar ratio of the vinyl epoxy monomer to the allyl halide.

[0022] In a specific embodiment of the present invention, the vinyl epoxy monomer can be one or more of glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. Therefore, R4 in the vinyl epoxy monomer and the quaternized epoxy polysiloxane is CH3 and / or H, and R5 is CH2 and / or CO.

[0023] The active hydrogen in the hydrogen-containing silicone oil (i.e., hydrogen-containing polydimethylsiloxane) is the hydrogen atom directly connected to the silicon atom on the main chain. The silicon atom site on the polysiloxane main chain directly connected to the hydrogen atom is an active site that can be grafted with a branched chain. Specifically, in the present invention, it is the silicon atom site that can be grafted with a quaternary ammonium salt structure fragment and an epoxy structure fragment. The preparation method of the quaternized epoxy polysiloxane provided by the present invention actually utilizes the reaction between the active hydrogen and the vinyl on the main chain of the hydrogen-containing silicone oil, so that the quaternary ammonium salt and the epoxy structure fragment can be grafted onto the main chain of the hydrogen-containing silicone oil. Based on this, the molar ratio of active hydrogen, allyl halogenated hydrocarbon, vinyl epoxy monomer and trialkylamine in the hydrogen-containing silicone oil is controlled to be (2-10):1:(1-10):(0.9-1.1), which can control the proportion of the grafted site in the polysiloxane main chain and the ratio between the quaternary ammonium salt and the epoxy fragment. It should be noted that when the molar ratio of the allyl halogenated hydrocarbon to the vinyl epoxy monomer is 1:(1-10), the i:(ni) in the obtained quaternary ammonium epoxy polysiloxane is 1:(1-10). It should be noted that the hydrogen-containing silicone oil used in the specific embodiment of the present invention has a molecular weight of 500-5000.

[0024] The quaternized epoxy polysiloxane prepared by the present invention can be regarded as an antibacterial and antifouling auxiliary agent capable of modifying the performance of epoxy resin. The main chain of the quaternized epoxy polysiloxane is PDMS (polydimethylsiloxane), which has the characteristics of low surface energy. The quaternary ammonium salt side chain segments introduced into the PDMS segment have excellent antibacterial properties. At the same time, the side chain segments with epoxy groups provide the possibility for PDMS to be added into the epoxy resin system as an auxiliary agent: after the epoxy structure fragment is introduced, the epoxy group can be used as a "binder", and the PDMS main chain and the resin polymer with the same epoxy are closely connected through COC chemical bonds through a ring-opening reaction.

[0025] The reason for limiting the ratio between quaternary ammonium salt and epoxy fragment is that the increase in the number of epoxy groups can correspondingly improve the compatibility between quaternary ammonium epoxy polysiloxane and epoxy resin, but this will also lead to a decrease in the antibacterial performance brought by the quaternary ammonium salt segment to the PDMS main chain; similarly, too many quaternary ammonium salt segments will lead to a decrease in the compatibility between quaternary ammonium epoxy polysiloxane and epoxy resin.

[0026] The reason for controlling the proportion of grafting sites in the polysiloxane main chain is that the application of the quaternized epoxy polysiloxane in the present invention is to prepare an antifouling and antibacterial coating, which requires that the surface energy of the polysiloxane should also be considered during the preparation of the quaternized epoxy polysiloxane. In the art, PDMS is often used as a low surface energy modifier. By grafting a certain proportion of quaternary ammonium salts and epoxy structural fragments on the PDMS main chain, the surface energy of PDMS can still be maintained in a relatively low range.

[0027] In a specific embodiment of the present invention, the catalyst in the above preparation method is a Custer catalyst, wherein the platinum content is 0.5-2.0wt%; the catalyst needs to be added to the reaction system until the mass of platinum is 7-80ppm of the total amount of reactants.

[0028] Preferably, the content of active hydrogen in the hydrogen-containing silicone oil is 0.1-0.36 wt %.

[0029] Preferably, the carbon number of any two alkyl groups among R1, R2 and R3 in the trialkylamine is 1-3.

[0030] More preferably, the alkyl group having a carbon number other than 1 to 3 in R1, R2 and R3 in the trialkylamine has a carbon number of 8 to 16.

[0031] The above scheme is preferred because it is necessary to comprehensively consider the ease of introducing the quaternary ammonium structure into the PDMS segment during the preparation process and the antibacterial properties that the quaternary ammonium structure can bring to the PDMS main chain. The longer the carbon chain length connected to the trialkylamine structure, the stronger the antibacterial properties of the quaternary ammonium salt, but the difficulty of the preparation process is also increased accordingly. The quaternized epoxy polysiloxane prepared by the above scheme has stronger antibacterial properties, and the difficulty of the preparation process is appropriate.

[0032] The reaction of allyl halide and trialkylamine is a Menschutkin reaction, and the reaction follows the mechanism of nucleophilic reaction. During the reaction, the lone pair of electrons on the N atom in the trialkylamine needs to attack the electrophilic α carbon on the allyl halide. If the three alkyl groups connected to the N atom are all alkyl groups with a large number of carbon atoms and large steric hindrance, the reaction is difficult to carry out. However, if the carbon numbers of the three alkyl groups are very small, although the steric hindrance is small, the antibacterial properties of the resulting quaternary ammonium structure are also reduced. Therefore, it is necessary to preferably select a scheme in which any two alkyl groups in R1, R2, and R3 in the trialkylamine have carbon numbers of 1 to 3, and the other alkyl group has carbon numbers of 8 to 16.

[0033] It should be noted that, it is preferred that any two alkyl groups of R1, R2 and R3 have carbon numbers of 1 to 3 and the other alkyl group has carbon numbers of 8 to 16, and the obtained trialkylamine is an alkyldimethylamine. In a specific embodiment of the present invention, the alkyldimethyl tertiary amine is selected from one or more of dodecyldimethyl tertiary amine, tetradecyldimethyl tertiary amine, hexadecyldimethyl tertiary amine, octyldimethyl tertiary amine and decyldimethyl tertiary amine.

[0034] The allyl halogenated hydrocarbon With trialkylamine The molar ratio is 1:(0.9-1.1), which enables the chlorine atom and the trialkylamine to fully react to form a quaternary ammonium salt.

[0035] First, the hydrogen-containing silicone oil, the catalyst, and the allyl-type halogenated hydrocarbon are mixed and reacted. The alkenyl group in the allyl-type halogenated hydrocarbon can undergo a silylation reaction with the silicon atom site connected to active hydrogen in the hydrogen-containing silicone oil. After the reaction is completed, the intermediate product obtained is a polysiloxane grafted with a halogenated hydrocarbon side chain; at this time, vinyl epoxy monomer and trialkylamine are added. The vinyl group in the vinyl epoxy monomer will also undergo a silylation reaction with the silicon atom site connected to active hydrogen in the hydrogen-containing silicone oil, and the epoxy structure fragment will be grafted onto the polysiloxane main chain. At the same time, the halogen atom in the halogenated hydrocarbon will also react with the amine group in the trialkylamine to form a quaternary ammonium structure, so a quaternary ammonium salt structure fragment can be formed. It can be seen that the above preferred embodiment is to separate the grafting of the epoxy structure and the quaternary ammonium salt structure in two steps.

[0036] Separately inserting epoxy and quaternary ammonium salt structural fragments in the PDMS main chain of hydrogen silicone oil in two steps can reduce the possibility of the two structural fragments affecting each other through steric hindrance and affecting the grafting success rate. In a specific embodiment of the present invention, after adding the vinyl epoxy monomer and the trialkylamine, an organic solvent needs to be added to the system to reduce the viscosity of the reaction system. The organic solvent can be any one or more of dimethylformamide, dimethylacetamide, and propylene glycol methyl ether acetate, and its amount is 40 to 120wt% of the total amount of the reactants.

[0037] In a specific embodiment of the present invention, a more specific reaction mode of the above preparation method can be: after mixing the hydrogen-containing silicone oil, the catalyst and the allyl halogenated hydrocarbon, reacting at 30-60°C for 2-8h, adding the vinyl epoxy monomer after the reaction is completed, heating to 90-120°C, reacting for 2-5h, cooling to 60-80°C after the reaction is completed, adding trialkylamine, and continuing the reaction for 1.5-6h to obtain the quaternary ammonium epoxy polysiloxane.

[0038] The present invention also protects a quaternary ammonium epoxy polysiloxane prepared by the above preparation method.

[0039] The present invention also protects a cationic light-cured plant oil-based antifouling and antibacterial coating, wherein the cationic light-cured plant oil-based antifouling and antibacterial coating comprises the quaternized epoxy polysiloxane.

[0040] The present invention also provides a method for preparing a cationic light-cured vegetable oil-based antifouling and antibacterial coating, comprising the following steps:

[0041] The quaternized epoxy polysiloxane, epoxy vegetable oil, cationic photocurable active diluent and cationic photoinitiator are uniformly mixed, and a cationic photocurable vegetable oil-based antifouling and antibacterial coating is obtained after photocuring;

[0042] The mass ratio of the quaternized epoxy polysiloxane to the epoxy vegetable oil is 1:(6-50).

[0043] Conventional epoxidized vegetable oils in the art are applicable to the present invention. In a specific embodiment of the present invention, the epoxidized vegetable oil can be any one or more of epoxidized soybean oil, epoxidized castor oil, epoxidized linseed oil, and epoxidized tung oil.

[0044] The conventional cationic photocuring active diluents in the art can be applied to the present invention. Specifically, the cationic photocuring active diluents used in the present invention are epoxy monomers and / or vinyl ether monomers. More specifically, it can be any one or more of triethylene glycol divinyl ether, 1,4-cyclohexyl dimethanol divinyl ether, 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexyl carboxylate, 3,3-[oxybismethylene]bis[3-ethyl]oxetane, bis[3,4-epoxycyclohexyl)methyl]adipate, pentaerythritol glycidyl ether, and trimethylolpropane triglycidyl ether.

[0045] Conventional cationic photoinitiators in the art can be applicable to the present invention. Specifically, the cationic photoinitiator used in the present invention can be a diaryl iodonium salt and / or a triaryl sulfonium salt, and more specifically, the cationic photoinitiator can be any one or more of 4,4-dimethyldiphenyl iodonium hexafluorophosphate, (4-octyloxyphenyl)phenyl iodonium hexafluoroantimonate, 4-(phenylthio)phenyldiphenylsulfonium hexafluorophosphate, bis[4-(phenylthio)phenyldiphenylsulfonium]hexafluorophosphate, 4-(phenylthio)phenyldiphenylsulfonium hexafluoroantimonate, and bis[4-(phenylthio)phenyldiphenylsulfonium]hexafluoroantimonate.

[0046] In the quaternized epoxy polysiloxane prepared by the present invention, both a quaternary ammonium salt structure and an epoxy structure are connected to the polysiloxane chain segment, wherein the quaternary ammonium salt structure has a bactericidal effect and can impart antibacterial properties to the final coating; and the polysiloxane main chain has a low surface energy and can provide a certain antifouling property to the final coating. The grafted epoxy group in the polysiloxane chain segment can react with the epoxy group on the epoxy vegetable oil to increase the interaction force with the epoxy vegetable oil, so that the polysiloxane and the epoxy vegetable oil can be used together as a prepolymer to provide antifouling and antibacterial properties to the final antifouling and antibacterial coating (the performance of the polymer in the photocuring system depends largely on the performance of the prepolymer).

[0047] The mass ratio of quaternized epoxy polysiloxane to epoxy vegetable oil is controlled to be 1: (6-50) in order to allow the two to react fully and the resulting antifouling and antibacterial coating to have better antifouling and antibacterial properties. When the mass of epoxy vegetable oil is too much, the properties of the resulting coating are mainly based on the properties of the epoxy vegetable oil itself, and the antifouling and antibacterial properties are reduced; and when the mass of the epoxy vegetable oil is too little, that is, the amount of the matrix is ​​too little, which makes it difficult to form a coating in the end.

[0048] After adding a cationic photoinitiator to the reaction system, the reaction system can undergo a cationic photocuring reaction, avoiding oxygen inhibition, with a high curing rate and a short curing time, while avoiding high energy consumption caused by high-temperature curing.

[0049] Conventional cationic photocuring conditions in the art can be applied to the present invention. Specifically, the wavelength of the light used in the photocuring is 200 to 800 nm. Specifically, the light power during the photocuring is 0.1 to 3 kW. Specifically, the photocuring time is 35 s to 5 min.

[0050] Preferably, the mass ratio of the quaternized epoxy polysiloxane, the cationic photocuring active diluent and the cationic photoinitiator is 1:(1-25):(0.1-2.5).

[0051] The above ratio is preferred, which can make the obtained coating have higher density and thus better antifouling and antibacterial properties.

[0052] Preferably, the cationic photocurable reactive diluent is an epoxy monomer.

[0053] The use of the above monomers to construct the antifouling and antibacterial coating of the present invention can fully reduce the viscosity of the system and reduce the use of organic solvents.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] The quaternized epoxy polysiloxane provided by the present invention can take into account both excellent antibacterial properties and low surface energy, and can be used together with epoxy vegetable oil as a prepolymer of a cationic photocuring polymerization system to prepare a biomass-based coating with both high antibacterial properties and high antifouling properties. The obtained coating has a water contact angle of more than 103°, an oil contact angle of more than 28.1°, excellent antifouling properties, and an antibacterial rate of more than 99.9%. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is the FTIR spectrum of the quaternized epoxy polysiloxane prepared in Example 2. DETAILED DESCRIPTION

[0057] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0058] Example 1

[0059] A quaternized epoxy polysiloxane having the structure shown in the following formula:

[0060]

[0061] In the above formula, R1, R2, and R3 are methyl, methyl, and tetradecyl, respectively, R4 is H, and R5 is CO;

[0062] In the above formula, i:(ni)=1:1, p=1.

[0063] The preparation method of quaternized epoxy polysiloxane in this embodiment comprises the following steps:

[0064] 100g hydrogen silicone oil 0.14g of Custer catalyst was mixed with 6.89g of allyl chloride (0.09mol) and reacted at 45°C for 7h. After the reaction was completed, 11.53g of glycidyl acrylate (0.09mol) was added, and the temperature was raised to 110°C and reacted for 4h. 21.73g of tetradecyl dimethyl tertiary amine (0.09mol) was added to react and reacted at 65°C for 4h. After the reaction was completed, quaternary ammonium epoxy polysiloxane was obtained;

[0065] The molar ratio of active hydrogen of the hydrogen-containing silicone oil, allyl chloride, tetradecyl dimethyl tertiary amine and vinyl epoxy monomer is 2:1:1:1;

[0066] The content of active hydrogen in the hydrogen-containing silicone oil is 0.18 wt %, that is, the active hydrogen in the hydrogen-containing silicone oil of this embodiment is 0.18 mol (the calculation process is: 100 g*0.18 wt % / 1 g / mol).

[0067] Example 2

[0068] A quaternized epoxy polysiloxane, which is different from Example 1 in that:

[0069] In the above formula, R1, R2, and R3 are methyl, methyl, and hexadecyl, respectively, R4 is CH3, and R5 is CO;

[0070] In the above formula, i:(ni)=1:9, p=1.

[0071] The preparation method of quaternized epoxy polysiloxane in this embodiment comprises the following steps:

[0072] 100g hydrogen silicone oil 1.8g of Custer catalyst and 2.75g of allyl chloride were mixed and reacted at 60°C for 2h. After the reaction was completed, 46.06g of glycidyl methacrylate was added, and the temperature was raised to 120°C and reacted for 2h. 9.7g of hexadecyl dimethyl tertiary amine was added and reacted at 80°C for 1.5h. After the reaction was completed, quaternary ammonium epoxy polysiloxane was obtained;

[0073] The molar ratio of active hydrogen of the hydrogen-containing silicone oil, allyl chloride, hexadecyl dimethyl tertiary amine and vinyl epoxy monomer is 10:1:1:9;

[0074] The content of active hydrogen in the hydrogen-containing silicone oil is 0.36 wt %, that is, the active hydrogen in the hydrogen-containing silicone oil of this embodiment is 0.36 mol.

[0075] Example 3

[0076] A quaternized epoxy polysiloxane, which is different from Example 1 in that:

[0077] In the above formula, R1, R2, and R3 are methyl, methyl, and hexadecyl, respectively, R4 is CH3, and R5 is CO;

[0078] In the above formula, i:(ni)=1:2.33, p=1.

[0079] The preparation method of quaternized epoxy polysiloxane in this embodiment comprises the following steps:

[0080] 100g hydrogen silicone oil 0.46g of Custer catalyst and 2.29g of allyl chloride were mixed and reacted at 30°C for 8h. After the reaction was completed, 6.4g of glycidyl acrylate and 2.28g of allyl glycidyl ether were added, and the temperature was raised to 90°C and reacted for 5h. 3.2g of dodecyl dimethyl tertiary amine and 4.46g of octadecyl dimethyl tertiary amine were added and reacted at 60°C for 6h. After the reaction was completed, quaternary ammonium epoxy polysiloxane was obtained;

[0081] The molar ratio of active hydrogen of the hydrogen-containing silicone oil, allyl chloride, trialkylamine (including dodecyldimethyl tertiary amine and octadecyldimethyl tertiary amine) and vinyl epoxy monomer is 3.33:1:1:2.33;

[0082] The content of active hydrogen in the hydrogen-containing silicone oil is 0.10 wt %, that is, the active hydrogen in the hydrogen-containing silicone oil of this embodiment is 0.10 mol.

[0083] Example 4

[0084] A method for preparing a cationic light-cured vegetable oil-based antifouling and antibacterial coating comprises the following steps:

[0085] The quaternary ammonium epoxy polysiloxane, epoxy soybean oil, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate and cationic photoinitiator prepared in Example 1 were uniformly mixed, and the mixture was irradiated with a 2 kW UV lamp for 35 seconds and then cured to obtain a cationic light-cured vegetable oil-based antifouling and antibacterial coating;

[0086] The mass ratio of the quaternized epoxy polysiloxane to the epoxy soybean oil is 1:30;

[0087] The mass ratio of the quaternized epoxy polysiloxane, the cationic photocuring active diluent and the cationic photoinitiator is quaternized epoxy polysiloxane: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate: cationic photoinitiator = 1:10:1.2, wherein the cationic photoinitiator is a mixture of 4-(phenylthio)phenyldiphenylsulfonium hexafluorophosphate and bis[4-(phenylthio)phenyldiphenylsulfonium]hexafluorophosphate, wherein the mass ratio of 4-(phenylthio)phenyldiphenylsulfonium hexafluorophosphate and bis[4-(phenylthio)phenyldiphenylsulfonium]hexafluorophosphate is 1:1.

[0088] Example 5

[0089] A method for preparing a cationic light-cured vegetable oil-based antifouling and antibacterial coating, which is different from Example 4 in that:

[0090] The quaternized epoxy polysiloxane is the quaternized epoxy polysiloxane prepared in Example 2;

[0091] The epoxy vegetable oil is a mixture of epoxy tung oil and epoxy soybean oil, wherein the mass ratio of epoxy tung oil to epoxy soybean oil is 1:2, and the mass ratio of the quaternized epoxy polysiloxane to the epoxy vegetable oil is 1:11.25;

[0092] The cationic photocuring active diluent is 3,3-[oxybismethylene]bis[3-ethyl]oxetane, and the mass ratio of the quaternized epoxy polysiloxane, the cationic photocuring active diluent and the cationic photoinitiator is quaternized epoxy polysiloxane: 3,3-[oxybismethylene]bis[3-ethyl]oxetane: cationic photoinitiator = 1:1:0.625;

[0093] The curing conditions are: irradiation under ultraviolet light with a power of 0.1 kW for 90 seconds.

[0094] Example 6

[0095] A method for preparing a cationic light-cured vegetable oil-based antifouling and antibacterial coating, which is different from Example 4 in that:

[0096] The quaternized epoxy polysiloxane is the quaternized epoxy polysiloxane prepared in Example 3;

[0097] The epoxy vegetable oil is a mixture of epoxy linseed oil and epoxy castor oil, wherein the mass ratio of the epoxy linseed oil to the epoxy castor oil is 1.2:1; the mass ratio of the quaternized epoxy polysiloxane to the epoxy vegetable oil is 1:27.5;

[0098] The cationic photocuring active diluent is a mixture of triethylene glycol divinyl ether, 3,4-epoxycyclohexyl methyl-3,4-epoxycyclohexyl carboxylate and bis[3,4-epoxycyclohexyl)methyl]adipate, wherein the mass ratio of the three is 1:2:1.5; the cationic photoinitiator is 4,4-dimethyldiphenyliodonium hexafluorophosphate; the mass ratio of the quaternized epoxy polysiloxane, the cationic photocuring active diluent and the cationic photoinitiator is 1:22.5:0.6.

[0099] The curing conditions are: irradiation under ultraviolet light with a power of 1 kW for 300 seconds.

[0100] Comparative Example 1

[0101] A method for preparing a cationic light-cured vegetable oil-based coating, which differs from Example 4 in that:

[0102] The epoxy soybean oil, the cationic photocuring active diluent and the cationic photoinitiator are uniformly mixed and a photocuring reaction is carried out.

[0103] Comparative Example 2

[0104] A method for preparing a free radical light-cured vegetable oil-based antifouling coating, which is different from Example 1 in that:

[0105] The antifouling coating was prepared according to the invention patent (publication number CN108504269A), and the preparation method of Example 1 was carried out, including the following steps:

[0106] 40g IPDI and 144g terminal hydroxyl polysiloxane were mixed uniformly, 0.28g dibutyltin dilaurate was added to the system, the temperature was raised to 85°C, the reaction was carried out for 2h, the temperature was lowered to 80°C, 0.28g of polymerization inhibitor methoxyphenol and 90g of pentaerythritol triacrylate were added, and 56g of propylene glycol methyl ether acetate was added to adjust the viscosity of the system, and the temperature was kept for 2h to obtain a low surface energy prepolymer A;

[0107] After the low surface energy prepolymer was cooled to room temperature, 25 g of photoinitiator 1773 and 200 g of pentaerythritol triacrylate were added, stirred evenly, coated on the substrate, and cured with 2 kW UV light for 35 s to obtain fluorine-free antifouling coating A.

[0108] Comparative Example 3

[0109] A method for preparing a free radical light-cured vegetable oil-based antifouling coating, which is different from Comparative Example 2 in that:

[0110] The UV light power was 0.1 kW and the irradiation time was 90 s.

[0111] Performance Testing

[0112] Contact angle test of coating surface: Dataphysics OCA40 Micro contact angle meter was used to test the contact angle of the coating surface. The amount of water and hexadecane used was 5 μL, and the average value was taken after 5 measurements.

[0113] Coating transmittance test: The transparency of the coating was tested using a UV spectrophotometer. The coating thickness was about 12 μm. The test was performed 5 times at different locations to obtain the average value.

[0114] Coating hardness test: The coating hardness is tested according to GB / T6739-1996 standard.

[0115] Coating corrosion resistance test: The coating corrosion resistance is tested according to HG / T 4077-2009 standard.

[0116] Coating antifouling performance test: The coating antifouling performance test mainly includes oily pen resistance test and self-cleaning test. Oily pen resistance test: If the oily pen shrinks on the coating surface and can be easily wiped off with a paper towel, it is evaluated as excellent oily pen resistance performance, otherwise it is evaluated as failed. Self-cleaning test: After the coating is immersed in crude oil and lifted up, if the crude oil shrinks and detaches from the coating surface, it is evaluated as excellent self-cleaning performance, otherwise it is evaluated as failed. If the oily pen resistance performance and self-cleaning performance are evaluated as excellent, the coating antifouling performance is excellent.

[0117] Antibacterial rate test of coating: The plate counting method was used to evaluate the antibacterial performance of the coating. 2 ) were immersed in 5mL of Escherichia coli and 5mL of Staphylococcus aureus liquid, with a concentration of 108CFU / mL, and then placed in a 37°C incubator for 3 hours. After the incubation, the coating surface was gently wiped with a sterile cotton swab, then placed in a test tube with 10mL of Ringer's solution, ultrasonicated for 5 minutes, 100μL of the bacterial liquid was dispersed in a sterile agar culture dish, and incubated at 37°C for 10h. The colonies were counted, and the antibacterial rate was calculated using an uncoated coverslip as a blank control. The antibacterial rate is the ratio of the difference between the number of blank sample colonies and the number of sample colonies to the number of blank sample colonies, and the average value was taken after three measurements.

[0118] The specific performance test data are shown in Table 1. Figure 1 As shown:

[0119] Table 1. Test results of the coatings obtained in the comparative examples and examples

[0120]

[0121] As can be seen from Table 1 above, the quaternized epoxy polysiloxane of the present invention has a quaternary ammonium salt segment with a bactericidal effect and a polysiloxane segment with an antifouling effect, and also has a reactive epoxy group, so a vegetable oil-based coating having both excellent antibacterial and antifouling properties can be prepared. As can be seen from the data of Examples 4 to 6, the cationic light-cured coating of the present invention has the characteristics of high transparency, high hardness, good corrosion resistance, excellent antifouling and antibacterial effects, etc.

[0122] It can be seen from the data of Comparative Example 1 and Example 4 in Table 1 that the coating without the addition of quaternary ammonium epoxy polysiloxane has poor water-oil contact angle, antifouling performance, corrosion resistance and antibacterial performance, indicating that the antifouling and antibacterial properties of the coating of the present invention are mainly achieved by grafting quaternary ammonium epoxy polysiloxane.

[0123] Comparative Examples 2 to 3 are coatings formed by polysiloxane without introducing quaternary ammonium salt segments on the main chain. It can be seen from Comparative Example 2 and Example 4 that the antifouling and antibacterial coating of the present invention is as good as the antifouling coating prepared by the prior art CN108504269A in terms of water-oil contact angle, transparency, hardness, corrosion resistance, antifouling performance, etc., but because the coating of the present invention introduces quaternary ammonium salt segments, the antibacterial performance is better.

[0124] It can be seen from Comparative Example 1, Comparative Example 2 and Example 4 that although the anti-fouling coating obtained in Comparative Example 2 can improve the antibacterial rate by reducing the surface adhesion of bacteria (this is achieved by increasing the contact angle), its antibacterial effect is not as good as the antibacterial effect of the present invention. This is because the antibacterial effect of the coating in the present invention is achieved by increasing the contact angle and introducing quaternary ammonium salt structural fragments, and the two achieve synergistic enhancement.

[0125] Comparative Example 3 and Example 5 are two coatings formed by curing under the same lighting conditions. It can be seen from Comparative Example 3 and Example 5 that under the curing conditions of reduced ultraviolet light power, the free radical photocuring coating surface in the prior art will have the problem of oxygen inhibition, so the surface will not dry, which leads to the poor comprehensive performance of Comparative Example 3 compared with the fully cured coating (Comparative Example 2), while the cationic photocuring coating has a high curing rate and excellent comprehensive coating performance due to the absence of oxygen inhibition (Examples 4-5).

[0126] Figure 1 FTIR spectrum of the quaternized epoxy polysiloxane prepared in Example 2 of the present invention. Figure 1 It can be confirmed that the Si-H fragment on the main chain of the hydrogenated silicone oil in Example 2 of the present invention and the C=C double bond structure fragment in the allyl chloride and vinyl epoxy monomers undergo a hydrosilylation reaction, so the intensity of the corresponding absorption peak in the IR spectrum of the obtained quaternary ammonium epoxy polysiloxane will weaken or even disappear.

[0127] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing a quaternized epoxy polysiloxane, characterized in that: The steps include: Hydrogen-containing silicone oil, catalyst and allyl halogenated hydrocarbon Mix well and react fully. Add vinyl epoxy monomer after the reaction is complete. Reaction, then add trialkylamine Carry out the reaction, and after the reaction is completed, quaternized epoxy polysiloxane can be obtained; The molar ratio of active hydrogen, allyl halogenated hydrocarbon, vinyl epoxy monomer and trialkylamine in the hydrogen-containing silicone oil is (2-10):1:(1-10):(0.9-1.1); In the allyl halogenated hydrocarbon, p=1-2, X=Cl, Br, I; in the trialkylamine, R1, R2, and R3 are each independently selected from any alkyl group; In the vinyl epoxy monomer, R4 is CH3 and / or H, and R5 is CH2 and / or CO; The hydrogen-containing silicone oil has the following structural formula: m and n represent the number of repeating units without active hydrogen and the number of repeating units containing active hydrogen in the hydrogen-containing silicone oil, respectively. The molecular weight of the hydrogen-containing silicone oil is 500 to 5000, and the content of active hydrogen in the hydrogen-containing silicone oil is 0.1 to 0.36 wt%.

2. The method for preparing quaternized epoxy polysiloxane according to claim 1, characterized in that: The carbon number of any two alkyl groups among R1, R2 and R3 in the trialkylamine is 1-3.

3. The method for preparing quaternized epoxy polysiloxane according to claim 2, characterized in that: The alkyl group with carbon number other than 1 to 3 in R1, R2 and R3 in the trialkylamine has carbon number of 8 to 16.

4. The method for preparing quaternized epoxy polysiloxane according to claim 1, characterized in that: Mix the hydrogenated silicone oil, the catalyst and the allyl halogenated hydrocarbon, and react at 30-60°C for 2-8 hours. After the reaction is completed, add the vinyl epoxy monomer, raise the temperature to 90-120°C, and react for 2-5 hours. After the reaction is completed, cool the temperature to 60-80°C, add trialkylamine, and continue the reaction for 1.5-6 hours to obtain the quaternary ammonium epoxy polysiloxane.

5. A quaternized epoxy polysiloxane prepared by the preparation method according to any one of claims 1 to 4.

6. A cationic light-cured vegetable oil-based antifouling and antibacterial coating, characterized in that: The cationic light-cured plant oil-based antifouling and antibacterial coating comprises the quaternized epoxy polysiloxane according to claim 5.

7. A method for preparing the cationic light-cured vegetable oil-based antifouling and antibacterial coating according to claim 6, characterized in that: The steps include: The quaternized epoxy polysiloxane, epoxy vegetable oil, cationic photocurable active diluent and cationic photoinitiator described in claim 5 are uniformly mixed, and a cationic photocurable vegetable oil-based antifouling and antibacterial coating is obtained after photocuring; The mass ratio of the quaternized epoxy polysiloxane to the epoxy vegetable oil is 1:(6-50).

8. The method for preparing the cationic light-cured vegetable oil-based antifouling and antibacterial coating according to claim 7, characterized in that: The mass ratio of the quaternized epoxy polysiloxane, the cationic photocuring active diluent and the cationic photoinitiator is 1:(1-25):(0.1-2.5).

9. The method for preparing the cationic light-cured vegetable oil-based antifouling and antibacterial coating according to claim 7, characterized in that: The epoxidized vegetable oil is any one or more of epoxidized soybean oil, epoxidized castor oil, epoxidized linseed oil and epoxidized tung oil.

10. The method for preparing the cationic light-cured vegetable oil-based antifouling and antibacterial coating according to claim 7, characterized in that: The cationic light-curing active diluent is an epoxy monomer and / or a vinyl ether monomer.

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