Antibacterial coating filler, preparation method thereof and antibacterial epoxy coating

Abstract

The invention belongs to the technical field of metal corrosion protection, and discloses an antibacterial coating filler, a preparation method thereof and an antibacterial coating. The coating filler is jelly and is prepared by mixing tetrakis hydroxymethyl phosphonium sulfate and a sodium molybdate solution, adding dodecyl guanidine hydrochloride, mixing and reacting. According to the coating filler, effective antibacterial components in a liquid antibacterial agent are cured in jelly by virtue of interaction of sodium molybdate, positively charged tetrakis hydroxymethyl phosphonium and guanidyl, so that the stability and antibacterial and antifouling properties of the antibacterial coating filler are further improved under the condition that the effective antibacterial components are not dissolved out. Meanwhile, the coating filler is added into the epoxy coating to be mixed, the epoxy coating formed by coating the surface of the to-be-protected object with the coating filler can enhance the stability, the antibacterial property and the adhesion resistance of the coating in the seawater environment, and the coating is suitable for most seawater environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal corrosion protection, and more specifically, relates to an antibacterial coating filler and a preparation method thereof, and an antibacterial epoxy coating. Background Art

[0002] Affected by the complex industrial environment, corrosion caused by microbial growth and metabolism accounts for 20% of the total corrosion of active structures, especially in the oil and gas industry and the marine industry, the proportion of microbial corrosion of metal structures (such as metal pipelines) has reached 50% and 70%. Coating is a common protective measure to control metal corrosion. The coating on the metal surface isolates the metal substrate from the corrosive medium space, thereby preventing the corrosive medium from corroding the metal.

[0003] However, a large number of studies have shown that the performance of coatings will be adversely affected by microorganisms in the environment. Under the influence of the metabolic activities of microorganisms, the coating will degrade, crack, and fall off, losing its protective function and may also cause crevice corrosion. For example, Progress in Organic Coatings (94, 2016, 49-55) reported that the impedance and adhesion of epoxy coatings were significantly reduced after immersion in a medium with SRB for 96 hours; International Journal of Electrochemical Science (14, 2019, 315-328) found that cracks and holes appeared on the surface of epoxy coatings immersed in seawater containing Bacillus flexus for 30 days, which accelerated the destruction and peeling of the coating. Adding antibacterial agents as fillers to coatings is a simple and efficient way to improve the antibacterial properties of coatings. Journal of Hospital Infection (129, 2022, 58-64) reported that adding cuprous oxide to coatings can effectively inhibit the growth and film formation of 12 bacteria / fungi such as Staphylococcus aureus. However, cuprous oxide antimicrobials are more effective when exposed to bacteria that secrete HS. - microorganisms become weak because HS - It can precipitate cuprous oxide and make it lose its antibacterial activity. Carbon (Carbon, 157, 2020, 217-233) reported that graphene oxide-based nanomaterials were used as coating fillers to enhance the antibacterial and comprehensive mechanical properties of the coating. Although the results were satisfactory, the preparation steps were too complicated and far from practical application.

[0004] Tetrakis(hydroxymethyl)phosphonium sulfate (THPS) and dodecylguanidine hydrochloride (GDMC) are widely used due to their excellent antibacterial properties, bacterial biofilm dispersibility, environmental protection and low cost. The cations generated by ionization of THPS and GDMC in water can be adsorbed on the surface of bacterial cells, interfering with the material exchange between bacteria and the outside world, while destroying the integrity of the cell membrane and inhibiting bacterial growth. At the same time, they can also be adsorbed on the surface of metal substrates through electrostatic force, van der Waals force, coordination bond, etc., thereby showing a certain corrosion inhibition effect. However, the long-term reciprocating large-scale use of antibacterial agents will increase the drug resistance of bacterial cells, increase the environmental burden, and the economic benefits will increase instead of decrease. If THPS and GDMC are added to epoxy coatings as coating fillers, once the coating enters the water environment, the antibacterial components therein will dissolve, which is better than nothing for the open marine environment, and the actual effect is the same as that of pure epoxy coatings. Therefore, if you want to add commonly used antibacterial agents as fillers to epoxy coatings to achieve low-cost long-term antibacterial, you must achieve the goal of solidifying the fillers and not dissolving them in the seawater environment. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides an antibacterial coating filler and a preparation method thereof, and an antibacterial epoxy coating. The purpose is to introduce a sodium molybdate solution into THPS and mix it evenly, and then blend it with GDMC to obtain a solid-phase coating filler. Sodium molybdate interacts with positively charged tetrakishydroxymethylphosphine and guanidine groups to solidify the effective antibacterial components in the liquid antibacterial agent in a colloid, thereby ensuring that the effective antibacterial components are not dissolved, thereby improving the stability and antibacterial and antifouling properties of the coating filler; after the coating filler is added to the epoxy coating to form an epoxy coating, the stability and antibacterial and anti-adhesion properties of the coating can be enhanced, thereby solving the technical problem that the filler does not dissolve in an aqueous environment, and can achieve extensive and long-lasting antibacterial and antifouling.

[0006] To achieve the above object, according to one aspect of the present invention, an antibacterial coating filler is provided. The coating filler is a colloid obtained by mixing tetrakis(hydroxymethyl)phosphonium sulfate and sodium molybdate solution, adding dodecylguanidine hydrochloride, mixing and reacting.

[0007] Preferably, the colloid is in a hydrated state or a dehydrated state.

[0008] Preferably, the raw material molar ratio of the tetrakis(hydroxymethyl)phosphonium sulfate, the sodium molybdate solution and dodecylguanidine hydrochloride is 1:1:1.

[0009] Preferably, the concentration of the sodium molybdate solution is 1M.

[0010] According to another aspect of the present invention, there is provided a method for preparing the antibacterial coating filler according to the first aspect, comprising the following steps:

[0011] (1) adding sodium molybdate solution to tetrakis(hydroxymethyl)phosphonium sulfate and stirring evenly to form a mixed solution;

[0012] (2) adding dodecylguanidine hydrochloride to the mixed solution of step (1), mixing and reacting the mixture, filtering out the waste liquid and washing with ultrapure water to obtain a colloidal coating filler.

[0013] Preferably, after the cleaning with ultrapure water, the coating filler is dried to obtain a coating filler in a dehydrated state.

[0014] Preferably, the raw material molar ratio of the tetrakis(hydroxymethyl)phosphonium sulfate, the sodium molybdate solution and dodecylguanidine hydrochloride is 1:1:1; and the concentration of the sodium molybdate solution is 1M.

[0015] Preferably, the concentration of the tetrakis(hydroxymethyl)phosphonium sulfate is 75wt%, the concentration of the dodecylguanidine hydrochloride is 30wt%, and the concentration of the sodium molybdate solution is 1M;

[0016] The volume ratio of the tetrakis(hydroxymethyl)phosphonium sulfate, sodium molybdate solution and dodecylguanidine hydrochloride is 1.1:3:(5.6-16.8).

[0017] According to another aspect of the present invention, there is provided an antimicrobial epoxy coating comprising the antimicrobial coating filler as described in another aspect of the present invention.

[0018] Preferably, the antibacterial coating filler is a dehydrated colloid, accounting for 1 to 10 wt % of the antibacterial epoxy coating.

[0019] In general, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

[0020] (1) The present invention provides an antibacterial coating filler, comprising tetrakis hydroxymethyl phosphonium sulfate (THPS), sodium molybdate and dodecylguanidine hydrochloride (GDMC). The present invention utilizes the synergistic effect of THPS and GDMC to promote the antibacterial and antifouling properties of the coating, wherein the ultra-long hydrophobic alkyl chain provided by GDMC can greatly enhance the hydrophobicity of the coating, and the tetrakis hydroxymethyl phosphonium in THPS has the effects of killing microorganisms and dispersing biofilms; sodium molybdate is utilized to interact with positively charged tetrakis hydroxymethyl phosphonium and guanidine groups to solidify the effective antibacterial components in the liquid antibacterial agent in the colloidal solid antibacterial agent, thereby ensuring that the stability and antibacterial and antifouling properties of the antibacterial coating filler are further enhanced without dissolving the effective antibacterial components.

[0021] (2) The coating filler of the present invention can be evenly mixed with the epoxy coating and coated on the surface of the object to be protected to form an epoxy coating of solidified filler. Since sodium molybdate interacts with tetrakis hydroxymethyl phosphine in THPS and guanidine in GDMC to form a solid antibacterial agent, the antibacterial active ingredients tetrakis hydroxymethyl phosphine and guanidine do not dissolve when used; and compared with directly adding sodium molybdate particles to the epoxy coating, it will form small particle holes on the surface after dissolution, which is not conducive to the protection of the coating. The antibacterial coating obtained based on the coating filler of the present invention reduces the attachment sites of bacteria, does not produce uneven performance, and does not produce holes. Compared with the prior art, the coating filler and the corresponding coating can effectively improve the environmental tolerance of the epoxy coating and achieve extensive and long-term antibacterial and antifouling. In addition, the coating filler and the corresponding coating do not contain heavy metal elements and are environmentally friendly.

[0022] (3) The present invention mixes THPS and sodium molybdate solution thoroughly to generate molybdenum blue reaction, and then mixes with GDMC, so that sodium molybdate combines with THPS and GDMC respectively to generate colloidal solid precipitation, thereby solidifying the effective antibacterial components in the coating filler of the liquid antibacterial agent through chemical interaction. In addition, the present invention solidifies the liquid antibacterial agent for the first time and adds it to the epoxy coating as an insoluble coating filler, which not only solves the problem of dissolution of the liquid antibacterial agent added to the epoxy coating, but also uses the solidified filler to achieve antibacterial adhesion and antibacterial properties. In particular, in the marine environment, the antibacterial components therein have a long-lasting effect and are not easy to dissolve, thereby achieving excellent protection, anti-biofilm adhesion characteristics and antibacterial properties under field conditions.

[0023] (4) The protective coating obtained based on the present invention is both environmentally friendly and has long-lasting protective properties, as described below Figures 4 to 5 As shown, the antibacterial epoxy coating formed by adding the liquid antibacterial agent solidified coating filler obtained by the present invention to the epoxy coating after spin / spraying reaches a bacterial desorption rate of more than 99.9%. After being immersed in a sulfate-reducing bacteria Desulfovibrioferrophilus solution for 60 days, there is almost no bacterial cell coverage, a small amount of attached microorganisms on the surface have been killed, and the coating is still intact and has no holes, with long-term protective properties.

[0024] (5) The preparation and use process of the filler of the present invention is simple, and the complicated sample preparation steps are greatly simplified. The sample preparation can be completed without any other process, and it is easy to mass-produce and scale up, and has a good industrial production foundation and broad application prospects. The obtained coating has excellent protective performance and can be used in almost all working conditions, especially in working conditions containing a large number of corrosive microorganisms. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1is a composition test diagram of the coating filler prepared in Example 1 of the present invention; wherein A is the infrared spectrum of the coating filler prepared in Example 1 and its individual components, and B is the infrared spectrum of the coating filler prepared in Example 1 and Na 2 MoO 4 X-ray diffraction pattern of .

[0026] Figure 2 This is the test data of the insolubility test of the antibacterial coating filler prepared in Example 1;

[0027] Figure 3 This is a hydrophilicity test of the epoxy coating with antibacterial coating filler added prepared in Example 1.

[0028] Figure 4 The metal substrate protected by the epoxy coating filled with solidified liquid antibacterial agent prepared in Example 1 and the metal substrate protected by the pure epoxy coating prepared in Comparative Example 1 were subjected to surface scanning and fluorescent image detection; wherein, Figure 4 (a) corresponds to the surface scan of pure epoxy coating. Figure 4 (b) corresponds to the surface scan of the epoxy coating with solidified filler added. Figure 4 (c) in the figure corresponds to the fluorescence image of pure epoxy coating. Figure 4 (d) corresponds to the fluorescence image of the epoxy coating with added solidified filler.

[0029] Figure 5 The metal substrate protected by the epoxy coating filled with solidified liquid antibacterial agent prepared in Example 2 and the metal substrate protected by the pure epoxy coating prepared in Comparative Example 2 were subjected to surface scanning and fluorescent image detection; wherein, Figure 5 (a) corresponds to the surface scan of pure epoxy coating. Figure 5 (b) corresponds to the surface scan of the epoxy coating with solidified filler added. Figure 5 (c) in the figure corresponds to the fluorescence image of pure epoxy coating. Figure 5 (d) corresponds to the fluorescence image of the epoxy coating with solidified filler added.

[0030] Figure 6 The adhesion and growth of sessile cells on the pure epoxy coating surface and the epoxy coating surface with GDMC added prepared in Example 3 are shown.

[0031] Figure 7 The adhesion and growth of sessile cells on the pure epoxy coating surface and the epoxy coating surface with THPS added prepared in Example 4 are shown.

[0032] Figure 8 The following are the adhesion and growth conditions of the sessile cells on the pure epoxy coating surface and the epoxy coating surface with amoxicillin added prepared in Example 5. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] Tetrakis(hydroxymethyl)phosphonium sulfate (THPS) used in the examples of the present invention is a 75% (mass fraction) aqueous solution purchased from Shanghai MacLean Biochemical Technology Co., Ltd.; dodecylguanidine hydrochloride (GDMC) is a 30% (mass fraction) aqueous solution purchased from Zhejiang Simo Holding Co., Ltd.; sodium molybdate was purchased from China National Pharmaceutical Group Co., Ltd.

[0035] According to a first aspect of the present invention, a method for preparing an antibacterial coating filler is provided, comprising the following steps:

[0036] (1) Add sodium molybdate solution to THPS and stir evenly to form a blue mixture liquid;

[0037] (2) adding GDMC to the liquid matrix of the mixture in (1) and mixing well to fully react until a colloid gradually appears;

[0038] Among them, 3 mL of 1 M sodium molybdate solution was mixed with every 1.1 mL of THPS, and 5.6 mL of GDMC was added to 4.1 mL of the mixture of THPS and sodium molybdate.

[0039] The stirring and mixing in the above steps may be carried out by any means to achieve a sufficient reaction.

[0040] Preferably, the material obtained in step (2) above is further dried and then immersed in ultrapure water for 24 hours until all soluble substances are dissolved out; the immersed sample is further dried to obtain a dehydrated colloid, which is the solid-phase coating filler.

[0041] According to the second aspect of the present invention, a method for using a coating filler obtained based on the first aspect is provided. After adding a liquid antibacterial and anti-solidification coating filler to an epoxy coating, the epoxy coating is applied to the surface of the facility to be protected (maintained) and dried naturally in the air to obtain a protective epoxy coating.

[0042] The coating is specifically performed by spin coating or spray coating; and the drying is performed by natural drying.

[0043] In the embodiments of the present invention, the brand of epoxy coating can be flexibly selected as long as the filler can be completely dispersed in the epoxy coating; in addition to metal substrates, the present invention is also applicable to other surfaces of protected utensils that require antibacterial and antifouling properties (not edible).

[0044] A protective coating formed by the method according to the third aspect above.

[0045] According to a fourth aspect of the present invention, there is provided the use of the protective coating formed by utilizing the antibacterial coating filler in antibacterial and antifouling applications.

[0046] The following are specific embodiments:

[0047] Embodiment 1:

[0048] This embodiment provides a method for preparing an antibacterial coating filler and adding it to an epoxy coating, comprising the following steps:

[0049] (1) Add 3 mL of 1 M sodium molybdate solution to 1.1 mL of THPS and stir to obtain a mixed solution.

[0050] (2) Add 5.6 mL of GDMC to the mixed solution obtained in step (1), wait for it to fully react, wash and evaporate the water to obtain a coating filler in which the liquid antibacterial agent is solidified.

[0051] (3) The cleaned coating filler in the above (2) is added to the epoxy coating at 2 wt %, sprayed on the surface of the metal to be protected (Q235 carbon steel is used in this embodiment, the following embodiments and the comparative example) and naturally dried to obtain an epoxy coating with a coating filler solidified with a liquid antibacterial agent.

[0052] Embodiment 2:

[0053] This embodiment provides a method for preparing an antibacterial coating filler and adding it to an epoxy coating, comprising the following steps:

[0054] (1) Add 3 mL of 1 M sodium molybdate solution to 1.1 mL of THPS and stir to obtain a mixed solution.

[0055] (2) Add 16.8 mL of GDMC to the mixed solution obtained in step (1), wait for it to fully react, wash and evaporate the water to obtain a coating filler in which the liquid antibacterial agent is solidified.

[0056] (3) The cleaned coating filler in the above (2) is added into the epoxy coating at 2 wt %, sprayed on the surface of Q235 carbon steel to be protected and dried naturally to obtain the epoxy coating with the coating filler solidified by the liquid antibacterial agent.

[0057] Comparative Example 1:

[0058] The difference between the preparation steps of this comparative example and Example 1 is that the solidified coating filler of liquid antibacterial agent is not added to the epoxy coating, and the pure epoxy coating is obtained by spraying it on the surface of Q235 carbon steel to be protected and drying it naturally.

[0059] Comparative Example 2:

[0060] The difference between the preparation steps of this comparative example and Example 2 is that the solidified coating filler of liquid antibacterial agent is not added to the epoxy coating, and the pure epoxy coating is obtained by spraying it on the surface of Q235 carbon steel to be protected and drying it naturally.

[0061] Comparative Example 3:

[0062] THPS (liquid) was added into the epoxy coating at a content of 2 wt %, and then sprayed on the surface of Q235 carbon steel to be protected and dried naturally to obtain the epoxy coating with THPS.

[0063] Comparative Example 4:

[0064] GDMC (liquid) was added into the epoxy coating at a content of 2 wt %, and then sprayed on the surface of Q235 carbon steel to be protected and dried naturally to obtain the epoxy coating with GDMC.

[0065] Comparative Example 5:

[0066] In order to compare with the traditional process of using antibacterial substances, an epoxy coating was prepared using the common soluble antibacterial drug amoxicillin as the antibacterial additive.

[0067] Performance testing:

[0068] Infrared spectrum and X-ray diffraction tests were performed on Example 1 and its individual components after drying, indicating that the antibacterial coating filler prepared did not change the original state of the components. Figure 1 As shown, the results of infrared spectrum and X-ray diffraction tests (PDF card indicates the standard peak of sodium molybdate) show that the characteristic peaks of THPS, sodium molybdate and GDMC have overlapped, the synthesized substance is amorphous, and the small characteristic peaks correspond to the peaks of sodium molybdate, indicating that the antibacterial coating filler has been successfully prepared and the effective components therein have been retained.

[0069] The coating filler of Example 1 was subjected to an insolubility test. Specifically, the solid phase coating filler after the addition of GDMC was fully reacted was fully dried at 80°C for 48 hours and then the initial weight was weighed, and then the sample was immersed in ultrapure water for 24 hours until all soluble substances were dissolved; the sample after immersion was further dried at 80°C for 48 hours and then weighed. The results are as follows: Figure 2As shown in the figure, Group 1 and Group 2 are the weight test results of two repeated experiments with the same dosage. The results show that there is almost no weight difference between the solid phase samples before and after immersion, indicating that the solid phase material is almost insoluble. The three elements S, P, and N were determined by XRF in the immersion solution after evaporation. The content was very small, and S was not measured, which indirectly proved the stability of the colloid.

[0070] The epoxy coating prepared in Example 1 and added with antibacterial coating filler was tested for hydrophilicity and hydrophobicity. Figure 3 The results show that the water droplet contact angle of the pure epoxy coating is 12.8°, while the water droplet contact angle of the epoxy coating with the addition of liquid antibacterial agent solidified coating filler is 86.4°. It is not difficult to see that the water droplet contact angle of the epoxy coating with the addition of liquid antibacterial agent solidified coating filler is 6.75 times that of the pure epoxy coating, and the hydrophobicity is greatly increased.

[0071] After the marine sulfate-reducing bacteria Desulfovibrio ferrophilus were anaerobically activated for three days using enriched artificial seawater (EASW) reported in Corrosion Science (Corrosion Science, 220, 2023, 111306), 1% (volume ratio) of the activated bacterial solution was injected into the EASW culture medium of the epoxy coating with solidified filler (prepared in Example 1), and anaerobically cultured in a constant temperature and humidity chamber at 37°C for 14 days and 60 days, respectively.

[0072] Similarly, 1% (volume ratio) of activated bacterial solution was injected into the EASW culture medium with pure epoxy coating (prepared in Comparative Example 1), and anaerobically cultured in a constant temperature and humidity chamber at 37° C. for 14 days and 60 days, respectively.

[0073] After the 14-day bacterial immersion experiment, the weight loss of the metal substrate protected by the epoxy coating based on the solidified liquid antibacterial agent obtained in Example 1 before and after immersion was less than 0.02 mg / cm 2 The weight loss of the metal substrate protected by the pure epoxy coating obtained in Comparative Example 1 before and after immersion was as high as 1.9 mg / cm 2 .

[0074] After the 60-day bacterial immersion experiment, the metal substrate protected by the epoxy coating based on the solidification filling of the liquid antibacterial agent obtained in Example 1 and the metal substrate protected by the pure epoxy coating prepared in Comparative Example 1 were respectively subjected to surface scanning and fluorescence image detection. The results are as follows: Figure 4 As shown in Figure 2, the surface of the pure epoxy coating is covered with sulfate-reducing bacteria Desulfovibrioferrophilus biofilm, and the cells are arranged in an intricate pattern, such as Figure 4As shown in (a) in the figure; however, only a small amount of sulfate-reducing bacteria were killed on the surface of the epoxy coating with solidified fillers, and the coating remained intact and free of holes, as shown in Figure 4 As shown in (b) in . Correspondingly, from Figure 4 From the surface fluorescence results of (c) and (d), it can be seen that the pure epoxy coating is almost covered by bacterial cells, while the epoxy coating with solidified fillers has almost no green fluorescence. It can be seen that the surface bacterial desorption rate of the composite coating is >99.9%.

[0075] Similarly, 1% (volume ratio) of activated bacterial solution was injected into the EASW culture medium of the epoxy coating with solidified filler (prepared in Example 2) and the pure epoxy coating (prepared in Comparative Example 2), and anaerobically cultured in a constant temperature and humidity chamber at 37°C for 60 days. Figure 5 As shown in the figure, after 60 days of bacterial immersion experiment, the surface of pure epoxy coating was covered with sulfate-reducing bacteria Desulfovibrio ferrophilus biofilm, the cells were arranged in a complex manner, and the coating had been peeled off and cracked on a large scale. Under the peeling layer, a considerable part of the sulfate-reducing bacteria biofilm was attached, and the protective effect was lost. Figure 5 As shown in (a) in the figure; on the surface of the epoxy coating with solidified fillers, only a few sulfate-reducing bacteria were killed, and no obvious cell metabolites were found. The coating was intact and had no holes, as shown in Figure 5 As shown in (b) in . Correspondingly, from Figure 5 From the surface fluorescence results of (c) and (d), it can be seen that the pure epoxy coating is almost covered by bacterial cells, while the epoxy coating with solidified fillers has almost no green fluorescence. It can be seen that the surface bacterial desorption rate of the composite coating is >99.9%.

[0076] Comparative Example 3 In a sulfate-reducing bacteria Desulfovibrio ferrophilus solution with EASW as the culture medium, the liquid antibacterial agent THPS of the present invention was used as the antibacterial additive to test the adhesion and growth of the fixed cells on the surface of the pure epoxy coating and the epoxy coating with THPS added after immersion for 14 days. 2wt% THPS solution was added to the epoxy coating, and after it was fully mixed, sprayed and dried, the epoxy coating with THPS added was obtained.

[0077] Compared with the pure epoxy coating of Comparative Example 1, the experimental results are as follows Figure 6 As shown in the figure, the number of fixed cells on the surface of pure epoxy coating and epoxy coating with THPS added after 14 days of culture is almost the same, indicating that the addition of such water-soluble antibacterial drugs cannot have long-term inhibition on bacteria. Therefore, the disadvantages of adding this traditional antibacterial substance are obvious.

[0078] Comparative Example 4 In a sulfate-reducing bacteria Desulfovibrio ferrophilus solution with EASW as the culture medium, the liquid antibacterial agent GDMC of the present invention was used as the antibacterial additive to test the adhesion and growth of the fixed cells on the surface of the pure epoxy coating and the epoxy coating with GDMC added after immersion for 14 days. A 2wt% GDMC solution was added to the epoxy coating, and after it was fully mixed, sprayed and dried, the epoxy coating with GDMC added was obtained.

[0079] Compared with the pure epoxy coating of Comparative Example 1, the experimental results are as follows Figure 7 As shown in the figure, the number of fixed cells on the surface of pure epoxy coating and epoxy coating with GDMC added after 14 days of culture is almost the same, indicating that the addition of such water-soluble antibacterial drugs cannot have long-term inhibition on bacteria. Therefore, the disadvantages of adding this traditional antibacterial substance are obvious.

[0080] Comparative Example 5 In the sulfate-reducing bacteria Desulfovibrio ferrophilus solution with EASW as the culture medium, the common soluble antibacterial drug amoxicillin was used as the antibacterial additive to test the adhesion and growth of the fixed cells on the surface of the pure epoxy coating and the epoxy coating with amoxicillin added after immersion for 14 days. 2wt% amoxicillin powder was added to the epoxy coating, and after it was fully mixed, sprayed and dried, the epoxy coating with amoxicillin added was obtained.

[0081] Compared with the pure epoxy coating of Comparative Example 1, the experimental results are as follows Figure 8 As shown in the figure, the number of fixed cells on the surface of pure epoxy coating and epoxy coating with amoxicillin added after 14 days of culture is almost the same, indicating that the addition of such water-soluble antibacterial drugs cannot have long-term inhibition on bacteria. Therefore, the disadvantages of adding this traditional antibacterial substance are obvious.

[0082] It will be easily understood by those skilled in the art that 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An antibacterial coating filler, characterized in that: The coating filler is a colloid, which is obtained by mixing tetrakis(hydroxymethyl)phosphonium sulfate and sodium molybdate solution, adding dodecylguanidine hydrochloride, mixing and reacting.

2. The antibacterial coating filler according to claim 1, characterized in that: The colloid is in a hydrated state or a dehydrated state.

3. The antibacterial coating filler according to claim 1, characterized in that: The raw material molar ratio of the tetrakis(hydroxymethyl)phosphonium sulfate, the sodium molybdate solution and dodecylguanidine hydrochloride is 1:1:(1-3).

4. The antibacterial coating filler according to claim 3, characterized in that: The concentration of the sodium molybdate solution is 1M.

5. The method for preparing the antibacterial coating filler according to any one of claims 1 to 4, characterized in that: The steps include: (1) adding sodium molybdate solution to tetrakis(hydroxymethyl)phosphonium sulfate and stirring evenly to form a mixed solution; (2) adding dodecylguanidine hydrochloride to the mixed solution of step (1), mixing and reacting the mixture, filtering out the waste liquid and washing with ultrapure water to obtain a colloid coating filler.

6. The method for preparing the antibacterial coating filler according to claim 5, characterized in that: After the ultrapure water cleaning, the coated filler is dried to obtain a dehydrated coated filler.

7. The method for preparing the antibacterial coating filler according to claim 5, characterized in that: The molar ratio of the tetrakis(hydroxymethyl)phosphonium sulfate, the sodium molybdate solution and the dodecylguanidine hydrochloride is 1:1:(1-3).

8. The method for preparing the antibacterial coating filler according to claim 7, characterized in that: The concentration of the tetrakis(hydroxymethyl)phosphonium sulfate is 75wt%, the concentration of the dodecylguanidine hydrochloride is 30wt%, and the concentration of the sodium molybdate solution is 1M; The volume ratio of the tetrakis(hydroxymethyl)phosphonium sulfate, the sodium molybdate solution and dodecylguanidine hydrochloride is 1.1:3:(5.6-16.8).

9. An antibacterial epoxy coating, characterized in that: Contains the antibacterial coating filler as described in any one of claims 1 to 4.

10. The antimicrobial epoxy coating according to claim 9, characterized in that: The antibacterial coating filler is a dehydrated colloid, and accounts for 1 to 10 wt % of the antibacterial epoxy coating.

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