An antibacterial epoxy ester modified acrylic resin dispersion and preparation method

Abstract

The present invention proposes an antibacterial epoxy ester modified acrylic resin dispersion and a preparation method, which belongs to the technical field of polymer material synthesis and is used to solve the technical problems that water-based antibacterial and anticorrosive coatings have poor antibacterial performance, poor coating system stability, and poor coating comprehensive performance. The present invention utilizes a quaternary ammonium salt group to introduce an unsaturated fatty acid into a sulphur-ene "click" reaction, and reacts with an epoxy resin to prepare an epoxy ester, and then adopts free radical polymerization to graft copolymerize an acrylic monomer with the epoxy ester to prepare an antibacterial epoxy ester modified acrylic resin dispersion. The resin takes into account the balance between antibacterial property and other properties, overcomes the problems of poor compatibility between an added antibacterial agent and a coating, easy agglomeration and discoloration of the antibacterial agent, and poor antibacterial effect, and the coating film has excellent storage stability, antibacterial property, mechanical properties, water resistance, and salt spray resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material synthesis, and in particular relates to an antibacterial epoxy ester modified acrylic resin dispersion and a preparation method thereof. Background Art

[0002] In recent years, with the growth of the national economy and the continuous enhancement of people's environmental awareness, the country's requirements for environmental protection have become increasingly higher, and the coatings industry has developed towards low pollution. Water-based antibacterial and anti-corrosion coatings use water as a dispersion medium or solvent, and have the advantages of being clean, environmentally friendly, and non-toxic. Water-based coatings have received widespread attention and are gradually replacing traditional solvent-based coatings in some fields.

[0003] Because water-based coatings use water as a dispersion medium, bacteria can easily grow in closed, poorly ventilated, or waterlogged environments. Therefore, water-based coatings have higher requirements for antibacterial properties. Currently, water-based antibacterial and anticorrosive coatings are not widely used, and solvent-based coatings still dominate the market. This is because water-based antibacterial and anticorrosive coatings still have problems such as poor antibacterial performance, poor coating system stability, and poor overall coating performance. Therefore, it is necessary to develop water-based structured antibacterial coatings with excellent antibacterial properties, good system stability, and excellent overall performance to better meet market needs.

[0004] Antimicrobial coatings can be divided into additive antimicrobial coatings and structural antimicrobial coatings. Additive antimicrobial coatings are coatings in which antimicrobial substances are directly added. For example, Patent Publication No. CN109321079A discloses a water-based antimicrobial coating, which uses a molybdenum-containing compound or a tungsten-containing compound as an antimicrobial agent, which is dispersed in a polymer aqueous dispersion to produce a water-based antimicrobial coating. Although this method is simple to operate and has low processing costs, due to defects in the process and the properties of the antimicrobial agent itself, there are problems such as poor compatibility between the antimicrobial agent and the coating, easy agglomeration and discoloration of the antimicrobial agent, and poor antimicrobial effect. Structural antimicrobial coatings are coatings in which organic antimicrobial agents are fixed in resin molecular chains, which can effectively solve problems such as precipitation of the antimicrobial agent, compatibility with the coating, and dispersion. However, the introduction of organic antimicrobial agents may have a certain degree of adverse effect on other properties of the coating, and a balance between the antimicrobial properties and other properties of the coating needs to be considered. Summary of the Invention

[0005] In response to the technical problems of poor antibacterial performance, poor coating system stability, and poor overall coating performance in water-based antibacterial and anticorrosive coatings, the present invention proposes an antibacterial epoxy ester modified acrylic resin dispersion and a preparation method, which has excellent mechanical properties, storage stability, water resistance, salt spray resistance, antibacterial properties, etc., and takes into account the balance between antibacterial properties and other properties.

[0006] In order to achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion comprises the following steps:

[0008] (1) Dissolve the quaternary ammonium salt antibacterial agent in solvent I and add it into the reactor together with fatty acid and photoinitiator. 2 The mixture was stirred and reacted under ultraviolet light for 30 minutes, and then the solvent I was removed under reduced pressure to obtain a modified fatty acid.

[0009] (2) Add the modified fatty acid, epoxy resin, and catalyst I to a reactor, introduce nitrogen, start stirring at 150 r / min, heat to 120-140°C, and react for 2-4 hours. Then add catalyst II, continue heating to 190-210°C, and react until the acid value is less than 5 mg KOH / g to obtain epoxy ester.

[0010] (3) cooling the epoxy ester to 100-140°C, adding solvent II and stirring at a constant temperature for 20-30 minutes, then uniformly mixing the vinyl monomer and thermal initiator and dripping them into the reactor at a constant speed, controlling the dripping time to be 3-4 hours, and keeping the temperature for 2-3 hours after the dripping is completed to obtain an antibacterial epoxy-modified acrylic resin;

[0011] (4) The obtained antibacterial epoxy-modified acrylic resin is cooled to 50-60° C., neutralized for 30 min by adding a neutralizer, and then slowly added with deionized water for high-speed dispersion and filtration to obtain an antibacterial epoxy-modified acrylic resin dispersion.

[0012] The added amounts of the components in the preparation method are the following parts by mass: 20 to 50 parts of fatty acid, 3 to 12 parts of quaternary ammonium salt antibacterial agent, 0.1 to 0.4 parts of photoinitiator, 40 to 80 parts of epoxy resin, 0.1 to 0.3 parts of catalyst I, 0.1 to 0.3 parts of catalyst II, 100 to 150 parts of vinyl monomer, 20 to 80 parts of solvent I, 80 to 130 parts of solvent II, 5 to 8 parts of thermal initiator, 10 to 15 parts of neutralizer, and 280 to 350 parts of deionized water.

[0013] The quaternary ammonium salt antibacterial agent is (2-mercaptoethyl)trimethylammonium chloride; the fatty acid is one or a combination of oleic acid, linoleic acid, linolenic acid, dehydrated ricinoleic acid, α-eleostearic acid, and octadecanoic acid (5, 9, 12); the photoinitiator is benzoin dimethyl ether; and solvent I is N,N-dimethylformamide.

[0014] The epoxy resin is one or a combination of bisphenol A epoxy resin E-51, E-44, E-20, and E-12; the catalyst I is tetrabutylammonium bromide; and the catalyst II is zinc oxide;

[0015] The solvent II is one or more of n-butanol, propylene glycol methyl ether, and dipropylene glycol methyl ether; the vinyl monomer is one or more of styrene, acrylonitrile, ethyl methacrylate, methyl methacrylate, methyl acrylate, butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, and acrylic acid; the thermal initiator is one or more of azobisisobutyronitrile, benzoyl peroxide, and tert-butyl perbenzoate;

[0016] The neutralizing agent is one or a combination of triethylamine and N,N-dimethylethanolamine.

[0017] An antibacterial epoxy ester modified acrylic resin dispersion is prepared by adopting the above preparation method.

[0018] Beneficial effects of the present invention:

[0019] 1. Quaternary ammonium antibacterial agents have the advantages of low price, fast sterilization speed and good effect. The sparse-ene "click" reaction has the characteristics of fast reaction rate and high selectivity. (2-mercaptoethyl)trimethylammonium chloride undergoes a sparse-ene "click" reaction with the double bond on the unsaturated fatty acid, introducing the quaternary ammonium salt group into the unsaturated fatty acid and further into the resin chain, giving the resin excellent antibacterial properties; the antibacterial rate of its coating against Staphylococcus aureus and Escherichia coli can reach more than 99%, and has long-lasting antibacterial properties.

[0020] 2. Unsaturated fatty acids are non-toxic, non-polluting, widely available, and low-cost. The introduction of unsaturated fatty acids into the resin chain not only creates more active grafting sites, increasing the grafting rate, but also imparts flexibility and partial crosslinking to the coating. The introduction of epoxy resin into the resin chain enhances the resin's adhesion to the substrate, improving the mechanical and water resistance properties of the waterborne acrylic coating.

[0021] 3. The resin prepared by this modification method takes into account the balance between antibacterial properties and other properties, overcoming the problems of poor compatibility between added antibacterial agents and coatings, easy agglomeration and discoloration of antibacterial agents, and poor antibacterial effect. The coating has excellent storage stability, antibacterial properties, mechanical properties, water resistance, and salt spray resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is the infrared spectrum of the dispersion coating of Example 1 of the present invention.

[0024] Figure 2 This is the gel permeation chromatogram of the resin of Example 1 of the present invention.

[0025] Figure 3 This is the particle size distribution diagram of the dispersion of Example 1 of the present invention. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion is as follows:

[0029] (1) 3.4 g (2-mercaptoethyl) trimethylammonium chloride was dissolved in 35 g N, N-dimethylformamide, and added into the reactor together with 20 g linolenic acid, 18 g oleic acid, and 0.1 g benzoin dimethyl ether. 2 The mixture was stirred and reacted under ultraviolet light for 30 minutes, and then N,N-dimethylformamide was removed under reduced pressure to obtain a modified fatty acid.

[0030] (2) The prepared modified fatty acid, 57 g of epoxy resin E-20, and 0.2 g of tetrabutylammonium bromide were added to a reactor, nitrogen was introduced, stirring was started at 150 r / min, the temperature was raised to 120° C. and the reaction was carried out for 4 h. Then, 0.2 g of zinc oxide was added, and the temperature was continued to be raised to 200° C. and the reaction was carried out until the acid value was less than 5 mg KOH / g to obtain epoxy ester;

[0031] (3) Cooling the prepared epoxy ester to 110°C, adding 89g of n-butanol and stirring at a constant temperature for 20min, then uniformly mixing 55g of styrene, 30g of methyl methacrylate, 23g of butyl acrylate, 6g of acrylic acid, and 5g of benzoyl peroxide, and then dripping them into the reactor at a uniform speed, controlling the dripping time to be 4h, and keeping the temperature for 2h after the dripping is completed to obtain an antibacterial epoxy-modified acrylic resin;

[0032] (4) The obtained antibacterial epoxy-modified acrylic resin was cooled to 50° C., 12.5 g of triethylamine was added for neutralization for 30 min, and then 320 g of deionized water was slowly added. After high-speed dispersion, the mixture was filtered to obtain an antibacterial epoxy-modified acrylic resin dispersion.

[0033] For the antibacterial epoxy modified acrylic resin dispersion prepared in Example 1, the infrared spectrum test results are shown in Figure 1 , 758cm in the infrared spectrum -1 The absorption peak of CS bond is at 3018cm -1 The antisymmetric stretching vibration peak of CH3 in quaternary ammonium salt is 1492 cm -1 The asymmetric vibration peak of CH3 is at 1382 cm -1 The symmetrical vibration peak of CH3 at 1727 cm -1 The ester carbonyl C=O stretching vibration peak is at 1640cm -1 There is no C=C absorption peak on the vinyl monomer, indicating that the double bond on the vinyl monomer reacted with the epoxy ester and was successfully grafted onto the epoxy ester molecular chain. The molecular weight of the dispersion was tested by gel permeation chromatography. The results are shown in Figure 2 The test results show that Mn = 5949, Mw = 66634, Mz = 389702. The particle size of the dispersion was tested using a laser particle size analyzer. The results are shown in Figure 3 , the test results show that Dv(50) is 0.0977μm and Dv(90) is 0.180μm.

[0034] Example 2

[0035] A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion is as follows:

[0036] (1) Dissolve 5.1 g (2-mercaptoethyl) trimethylammonium chloride in 50 g N,N-dimethylformamide, add 28 g linolenic acid, 11 g oleic acid, and 0.12 g benzoin dimethyl ether into the reactor and heat at 20 mW / cm 2 The mixture was stirred and reacted under ultraviolet light for 30 minutes, and then N,N-dimethylformamide was removed under reduced pressure to obtain a modified fatty acid.

[0037] (2) The prepared modified fatty acid, 57 g of epoxy resin E-20, and 0.2 g of tetrabutylammonium bromide were added to a reactor, nitrogen was introduced, stirring was started at 150 r / min, the temperature was raised to 120° C. and the reaction was carried out for 4 h. Then, 0.2 g of zinc oxide was added, and the temperature was continued to be raised to 200° C. and the reaction was carried out until the acid value was less than 5 mg KOH / g to obtain epoxy ester;

[0038] (3) Cooling the prepared epoxy ester to 110°C, adding 89g of n-butanol and stirring at a constant temperature for 20min, then uniformly mixing 50g of styrene, 32g of methyl methacrylate, 26g of butyl acrylate, 8g of methacrylic acid, and 5g of benzoyl peroxide, and then dripping them into the reactor at a uniform speed, controlling the dripping time to be 4h, and keeping the temperature for 2h after the dripping is completed to obtain an antibacterial epoxy-modified acrylic resin;

[0039] (4) The obtained antibacterial epoxy-modified acrylic resin was cooled to 50° C., 12.5 g of triethylamine was added for neutralization for 30 min, and then 320 g of deionized water was slowly added. After high-speed dispersion, the mixture was filtered to obtain an antibacterial epoxy-modified acrylic resin dispersion.

[0040] Example 3

[0041] A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion is as follows:

[0042] (1) 6.8 g (2-mercaptoethyl) trimethylammonium chloride was dissolved in 70 g N, N-dimethylformamide, and added into the reactor together with 25 g linolenic acid, 16 g linoleic acid, and 0.16 g benzoin dimethyl ether. 2 The mixture was stirred and reacted under ultraviolet light for 30 minutes, and then N,N-dimethylformamide was removed under reduced pressure to obtain a modified fatty acid.

[0043] (2) The prepared modified fatty acid, 65 g of epoxy resin E-20, and 0.2 g of tetrabutylammonium bromide were added to a reactor, N2 was introduced, stirring was started at 150 r / min, the temperature was raised to 120°C and the reaction was carried out for 4 h, then 0.2 g of zinc oxide was added, the temperature was continued to be raised to 200°C, and the reaction was carried out until the acid value was less than 5 mg KOH / g to obtain epoxy ester;

[0044] (3) Cooling the prepared epoxy ester to 120° C., adding 48 g of n-butanol and 42 g of propylene glycol methyl ether and stirring at a constant temperature for 20 min, then uniformly mixing 52 g of styrene, 30 g of methyl methacrylate, 26 g of butyl acrylate, 9 g of methacrylic acid, and 5 g of tert-butyl perbenzoate, and dripping them into the reactor at a uniform speed, controlling the dripping time to be 4 h, and keeping the temperature for 2 h after the dripping is completed to obtain an antibacterial epoxy modified acrylic resin;

[0045] (4) The obtained antibacterial epoxy-modified acrylic resin was cooled to 50° C., 13.5 g of triethylamine was added for neutralization for 30 min, and then 320 g of deionized water was slowly added. After high-speed dispersion, the mixture was filtered to obtain an antibacterial epoxy-modified acrylic resin dispersion.

[0046] Example 4

[0047] A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion is as follows:

[0048] (1) Dissolve 5.1 g (2-mercaptoethyl) trimethylammonium chloride in 50 g N,N-dimethylformamide, add 25 g linolenic acid, 14 g linoleic acid, and 0.12 g benzoin dimethyl ether into the reactor and heat at 20 mW / cm 2 The mixture was stirred and reacted under ultraviolet light for 30 minutes, and then N,N-dimethylformamide was removed under reduced pressure to obtain a modified fatty acid.

[0049] (2) The prepared modified fatty acid, 57 g of epoxy resin E-20, and 0.2 g of tetrabutylammonium bromide were added to a reactor, nitrogen was introduced, stirring was started at 150 r / min, the temperature was raised to 120° C. and the reaction was carried out for 4 h. Then, 0.2 g of zinc oxide was added, and the temperature was continued to be raised to 200° C. and the reaction was carried out until the acid value was less than 5 mg KOH / g to obtain epoxy ester;

[0050] (3) Cooling the prepared epoxy ester to 120° C., adding 48 g of n-butanol and 42 g of propylene glycol methyl ether and stirring at a constant temperature for 20 min, then uniformly mixing 45 g of styrene, 38 g of methyl methacrylate, 28 g of butyl acrylate, 7 g of methacrylic acid, and 5 g of tert-butyl perbenzoate, and dripping them into the reactor at a uniform speed, controlling the dripping time to be 4 h, and keeping the temperature for 2 h after the dripping is completed to obtain an antibacterial epoxy modified acrylic resin;

[0051] (4) The obtained antibacterial epoxy-modified acrylic resin was cooled to 50° C., 11.5 g of triethylamine was added for neutralization for 30 min, and then 320 g of deionized water was slowly added. After high-speed dispersion, the mixture was filtered to obtain an antibacterial epoxy-modified acrylic resin dispersion.

[0052] Example 5

[0053] A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion is as follows:

[0054] (1) Dissolve 12g (2-mercaptoethyl) trimethylammonium chloride in 80g N,N-dimethylformamide, add 30g dehydrated ricinoleic acid, 20g α-eleostearic acid, and 0.4g benzoin dimethyl ether into the reactor and heat at 20mW / cm 2 The mixture was stirred and reacted under ultraviolet light for 30 minutes, and then N,N-dimethylformamide was removed under reduced pressure to obtain a modified fatty acid.

[0055] (2) The prepared modified fatty acid, 80 g of epoxy resin E-51, and 0.3 g of tetrabutylammonium bromide were added to a reactor, nitrogen was introduced, stirring was started at 150 r / min, the temperature was raised to 130° C. and the reaction was carried out for 3 h. Then 0.3 g of zinc oxide was added, the temperature was continued to be raised to 190° C., and the reaction was carried out until the acid value was less than 5 mg KOH / g to obtain epoxy ester;

[0056] (3) Cooling the obtained epoxy ester to 100° C., adding 80 g of dipropylene glycol methyl ether and stirring at a constant temperature for 30 min, then uniformly mixing 40 g of acrylonitrile, 50 g of ethyl acrylate, 10 g of acrylic acid, and 6.5 g of azobisisobutyronitrile, and then dripping the mixture into the reactor at a uniform speed, controlling the dripping time to be 3 h, and keeping the temperature for 2.5 h after the dripping is completed to obtain an antibacterial epoxy modified acrylic resin;

[0057] (4) The obtained antibacterial epoxy-modified acrylic resin was cooled to 60°C, 15 g of N, N-dimethylethanolamine was added for neutralization for 30 min, and then 350 g of deionized water was slowly added. After high-speed dispersion, the mixture was filtered to obtain an antibacterial epoxy-modified acrylic resin dispersion.

[0058] Example 6

[0059] A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion is as follows:

[0060] (1) 8 g (2-mercaptoethyl) trimethylammonium chloride was dissolved in 50 g N, N-dimethylformamide, and added into the reaction kettle together with 20 g octadecanoic acid (5, 9, 12)-trienoic acid and 0.1 g benzoin dimethyl ether. 2 The mixture was stirred and reacted under ultraviolet light for 30 minutes, and then N,N-dimethylformamide was removed under reduced pressure to obtain a modified fatty acid.

[0061] (2) The prepared modified fatty acid, 20 g of epoxy resin E-51, 20 g of epoxy resin E-12, and 0.1 g of tetrabutylammonium bromide were added to a reactor, nitrogen was introduced, stirring was started at 150 r / min, the temperature was raised to 140° C. and the reaction was carried out for 2 h. Then, 0.1 g of zinc oxide was added, the temperature was continued to be raised to 210° C., and the reaction was carried out until the acid value was less than 5 mg KOH / g to obtain epoxy ester;

[0062] (3) Cooling the prepared epoxy ester to 140° C., adding 60 g of dipropylene glycol methyl ether and 70 g of n-butanol and stirring at a constant temperature for 25 min, then uniformly mixing 140 g of ethyl methacrylate, 10 g of methacrylic acid, and 8 g of benzoyl peroxide, and then dripping them into the reactor at a uniform speed, controlling the dripping time to be 3.5 h, and keeping the temperature for 3 h after the dripping is completed to obtain an antibacterial epoxy-modified acrylic resin;

[0063] (4) The obtained antibacterial epoxy-modified acrylic resin was cooled to 55°C, 10 g of N, N-dimethylethanolamine was added for neutralization for 30 min, and then 330 g of deionized water was slowly added. After high-speed dispersion, the mixture was filtered to obtain an antibacterial epoxy-modified acrylic resin dispersion.

[0064] Example 7

[0065] A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion is as follows:

[0066] (1) Dissolve 3g (2-mercaptoethyl) trimethylammonium chloride in 20g N,N-dimethylformamide, add 20g oleic acid and 0.1g benzoin dimethyl ether into the reactor, and heat at 20mW / cm 2 The mixture was stirred and reacted under ultraviolet light for 30 minutes, and then N,N-dimethylformamide was removed under reduced pressure to obtain a modified fatty acid.

[0067] (2) The prepared modified fatty acid, 50 g of epoxy resin E-44, and 0.2 g of tetrabutylammonium bromide were added to a reactor, N2 was introduced, stirring was started at 150 r / min, the temperature was raised to 120°C and the reaction was carried out for 4 h, then 0.2 g of zinc oxide was added, the temperature was continued to be raised to 200°C, and the reaction was carried out until the acid value was less than 5 mg KOH / g to obtain epoxy ester;

[0068] (3) Cooling the prepared epoxy ester to 110°C, adding 80g of n-butanol and stirring at a constant temperature for 20min, then uniformly mixing 50g of methyl acrylate, 40g of 2-ethylhexyl acrylate, 10g of acrylic acid, and 7g of benzoyl peroxide, and dripping them into the reactor at a uniform speed, controlling the dripping time to be 4h, and keeping the temperature for 2h after the dripping is completed to obtain an antibacterial epoxy-modified acrylic resin;

[0069] (4) The obtained antibacterial epoxy-modified acrylic resin was cooled to 50° C., 12 g of triethylamine was added for neutralization for 30 min, and then 280 g of deionized water was slowly added. After high-speed dispersion, the mixture was filtered to obtain an antibacterial epoxy-modified acrylic resin dispersion.

[0070] Comparative Example 1

[0071] A method for preparing an acrylic resin dispersion:

[0072] (1) Add 47 g of n-butanol to a reactor, heat it to 110° C., then mix 50 g of styrene, 32 g of methyl methacrylate, 26 g of butyl acrylate, 8 g of methacrylic acid, and 5 g of benzoyl peroxide, and uniformly drip them into the reactor. The dripping time is controlled to be 4 h. After the dripping is completed, heat is maintained for 2 h to obtain an acrylic resin;

[0073] (2) The obtained acrylic resin dispersion was cooled to 50° C., 5.9 g of triethylamine was added for neutralization for 30 min, and then 170 g of deionized water was slowly added. After high-speed dispersion, the mixture was filtered to obtain an acrylic resin dispersion.

[0074] Comparative Example 2

[0075] A method for preparing an epoxy ester modified acrylic resin dispersion is as follows:

[0076] (1) Add 28 g of linolenic acid, 11 g of oleic acid, 57 g of epoxy resin E-20, and 0.2 g of tetrabutylammonium bromide to a reactor, introduce nitrogen, stir at 150 rpm, heat to 120° C., and react for 4 h. Then, add 0.2 g of zinc oxide, continue heating to 200° C., and react until the acid value is less than 5 mg KOH / g to obtain epoxy ester.

[0077] (2) Cooling the prepared epoxy ester to 110° C., adding 89 g of n-butanol and stirring at a constant temperature for 20 min, then uniformly mixing 50 g of styrene, 32 g of methyl methacrylate, 26 g of butyl acrylate, 8 g of methacrylic acid, and 5 g of benzoyl peroxide, and then dripping them into the reactor at a uniform speed, controlling the dripping time to be 4 h, and keeping the temperature for 2 h after the dripping is completed to obtain an epoxy-modified acrylic resin;

[0078] (3) The obtained epoxy-modified acrylic resin was cooled to 50° C., 12.5 g of triethylamine was added for neutralization for 30 min, and then 320 g of deionized water was slowly added. The mixture was dispersed at high speed and then filtered to obtain an epoxy-modified acrylic resin dispersion.

[0079] To further illustrate the antibacterial epoxy-modified acrylic resin dispersion disclosed in the present invention, the present invention also conducted corresponding tests on the dispersions and coating film properties prepared in Examples 1 to 4 and Comparative Examples 1 to 2. Comparative Example 3 is a structural antibacterial coating prepared according to Example 1 in Patent Publication No. CN112210254A. Comparative Example 4 is an additive antibacterial coating, commercially available under the brand name NY-2601B. The test performance results are shown in the following table:

[0080] Table 1 Test performance results

[0081]

[0082]

[0083] As can be seen from Table 1 above, the acrylic resin coating of Comparative Example 1 has certain defects in performance and basically has no antibacterial properties; the epoxy ester modified acrylic resin coating of Comparative Example 2 does not introduce a quaternary ammonium salt structure, and the coating performance is excellent, but basically has no antibacterial properties; the coating of Comparative Example 3 is poor in aging resistance and water resistance, which leads to a significant decrease in long-term antibacterial properties; Comparative Example 4 has poor storage stability, which leads to poor antibacterial properties; the antibacterial epoxy modified acrylic resin coating of the present invention has the advantages of excellent antibacterial properties, storage stability, good water and salt spray resistance, and strong adhesion.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing an antibacterial epoxy ester modified acrylic resin dispersion, characterized in that: The following steps are involved: (1) The quaternary ammonium salt antibacterial agent is dissolved in solvent I and added into a reactor together with a fatty acid and a photoinitiator, and reacted under ultraviolet light to obtain a modified fatty acid; (2) Adding modified fatty acid, epoxy resin and catalyst I into a reactor, reacting for a period of time in an inert gas atmosphere, then adding catalyst II to continue the reaction, and finally obtaining epoxy ester; (3) Mixing epoxy ester with solvent II, then uniformly mixing vinyl monomer and thermal initiator and dripping them into the reactor to react, thereby preparing antibacterial epoxy modified acrylic resin; (4) adding a neutralizing agent to the antibacterial epoxy-modified acrylic resin for neutralization, then adding deionized water for high-speed dispersion and filtering to obtain an antibacterial epoxy-modified acrylic resin dispersion; The addition amount of each component in the preparation method is the following parts by mass: 20-50 parts of fatty acid, 3-12 parts of quaternary ammonium antibacterial agent, 0.1-0.4 parts of photoinitiator, 40-80 parts of epoxy resin, 0.1-0.3 parts of catalyst I, 0.1-0.3 parts of catalyst II, 100-150 parts of vinyl monomer, 20-80 parts of solvent I, 80-130 parts of solvent II, 5-8 parts of thermal initiator, 10-15 parts of neutralizer, and 280-350 parts of deionized water; The quaternary ammonium salt antibacterial agent is (2-mercaptoethyl) trimethylammonium chloride; the fatty acid is one or a combination of oleic acid, linoleic acid, linolenic acid, dehydrated ricinoleic acid, α-eleostearic acid, and octadecanoic acid (5, 9, 12); the photoinitiator is benzoin dimethyl ether; and solvent I is N,N-dimethylformamide. In the step (3), when the epoxy ester is at 100-140° C., solvent II is added and stirred at a constant temperature for 20-30 minutes. Then, the vinyl monomer and thermal initiator are mixed evenly and then dripped into the reactor at a uniform speed. The dripping time is controlled to be 3-4 hours. After the dripping is completed, the temperature is kept for 2-3 hours to obtain an antibacterial epoxy-modified acrylic resin.

2. The method for preparing the antibacterial epoxy ester modified acrylic resin dispersion according to claim 1, wherein: The epoxy resin is one or a combination of bisphenol A epoxy resins E-51, E-44, E-20, and E-12; the catalyst I is tetrabutylammonium bromide; and the catalyst II is zinc oxide.

3. The method for preparing the antibacterial epoxy ester modified acrylic resin dispersion according to claim 1, wherein: The solvent II is one or a combination of n-butanol, propylene glycol methyl ether, and dipropylene glycol methyl ether; the vinyl monomer is one or a combination of styrene, acrylonitrile, ethyl methacrylate, methyl methacrylate, methyl acrylate, butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, and acrylic acid; and the thermal initiator is one or a combination of azobisisobutyronitrile, benzoyl peroxide, and tert-butyl perbenzoate.

4. The method for preparing the antibacterial epoxy ester modified acrylic resin dispersion according to claim 1, wherein: The neutralizing agent is one or a combination of triethylamine and N,N-dimethylethanolamine.

5. The method for preparing the antibacterial epoxy ester modified acrylic resin dispersion according to claim 1, wherein: In step (2), the reaction time in the inert gas atmosphere is 2-4 hours, and the reaction temperature is 120-140° C.; then, after adding zinc oxide, the reaction temperature is 190-210° C., and the epoxy ester is obtained after the reaction reaches an acid value of less than 5 mg KOH / g.

6. The method for preparing the antibacterial epoxy ester modified acrylic resin dispersion according to claim 1, wherein: In the step (4), a neutralizing agent is added to the antibacterial epoxy-modified acrylic resin when the temperature is 50-60°C.

7. An antibacterial epoxy ester modified acrylic resin dispersion prepared by the method according to any one of claims 1 to 6.

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