Organic silicon-based antifouling paint and preparation method thereof

Abstract

The invention discloses an organosilicon-based antifouling coating and a preparation method thereof, and belongs to the technical field of organosilicon coatings, the organosilicon-based antifouling coating comprises the following raw materials: dihydroxyl-terminated polydimethylsiloxane, functionalized polyvinylpyrrolidone, dihydroxyl-terminated fluorine-containing polysiloxane, an antifouling agent, fumed silica, tetraethoxysilane, stannous octoate and tetrahydrofuran; the preparation method comprises the following steps: dissolving dihydroxyl-terminated polydimethylsiloxane, functionalized polyvinylpyrrolidone and dihydroxyl-terminated fluorine-containing polysiloxane in tetrahydrofuran, then adding an anti-fouling agent, fumed silica, tetraethoxysilane and stannous octoate, and stirring and mixing at room temperature, thereby obtaining the product. According to the organic silicon-based antifouling coating disclosed by the invention, two aspects of reducing the adhesion of the surface of the coating and the growth of fouling organisms are combined, so that the adhesion of large fouling organisms at a high water flow speed can be effectively resisted, the adsorption of bacteria and diatom in low-flow-speed or static seawater can also be effectively resisted, and the application range of the organic silicon-based antifouling coating is greatly expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of organosilicon coatings, and in particular relates to an organosilicon-based antifouling coating and a preparation method thereof. Background Art

[0002] Applying antifouling paint on the surface of marine equipment is the simplest, most efficient and most widely used method to solve the fouling problem. Silicone-based paint has the characteristics of low surface energy and low elastic modulus, and is considered to be an environmentally friendly antifouling paint that can effectively resist marine fouling organisms. Silicone-based paint can effectively resist the attachment of large fouling organisms (such as oysters, mussels, barnacles, etc.) under high water flow rates, but cannot effectively resist the nonspecific adsorption of the marine mucus layer composed of bacteria, diatoms and their secreted extracellular polymer matrix, which limits the application of silicone-based paint on marine equipment at low flow rates or static states.

[0003] 4,5-Dichloro-N-octyl-4-isothiazoline-3-one (DCOIT) is an environmentally friendly bactericidal antifouling agent. It has good killing properties against various bacteria and microorganisms, and can prevent the attachment of large algae and protozoa, thereby effectively protecting the surface of marine equipment from biological invasion. It is widely used in marine antifouling coatings. However, the existing technology generally directly mixes DCOIT, silicone polymers and other auxiliary components to obtain silicone-based antifouling coatings, and then sprays them on the surface of marine equipment to form antifouling coatings. There is an initial burst release phenomenon of DCOIT in the antifouling coating, that is, a high content of DCOIT will be released in large quantities in a short period of time, and its release concentration is much higher than the effective concentration for inhibiting the attachment of fouling organisms; while the release amount of DCOIT in the middle and late stages will decrease rapidly, which is not enough to reach the required concentration for inhibiting the attachment of fouling organisms. Therefore, how to achieve long-term sustained release of DCOIT in silicone-based coatings and improve the antifouling effect is a technical problem that needs to be solved at present. Summary of the invention

[0004] The object of the present invention is to provide an organosilicon-based antifouling coating and a preparation method thereof, so as to solve the problems in the background technology.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] An organosilicon-based antifouling coating comprises the following raw materials in parts by weight:

[0007]

[0008] Further, the functionalized polyvinyl pyrrolidone is prepared by the following steps:

[0009] Add hydroxy-terminated polyvinyl pyrrolidone to tetrahydrofuran, stir and mix to dissolve, then add (3-isocyanopropyl)triethoxysilane and dibutyltin dilaurate, stir and react at 60-65°C for 2-3h to obtain functionalized polyvinyl pyrrolidone. Under the catalysis of dibutyltin dilaurate, the isocyanate group in (3-isocyanopropyl)triethoxysilane reacts with the terminal hydroxyl group of hydroxy-terminated polyvinyl pyrrolidone to obtain triethoxysilane-terminated functionalized polyvinyl pyrrolidone.

[0010] Furthermore, the usage ratio of the hydroxy-terminated polyvinyl pyrrolidone, tetrahydrofuran, (3-isocyanatopropyl)triethoxysilane and dibutyltin dilaurate is 8g:8-10mL:0.8g:6-6.3mg.

[0011] Furthermore, the hydroxy-terminated polyvinyl pyrrolidone is prepared by the following method:

[0012] Azobisisobutyronitrile was added to N,N-dimethylformamide and stirred to dissolve, and at the same time, vacuum was evacuated and nitrogen was introduced to remove oxygen, and then N-vinylpyrrolidone and mercaptoethanol were added dropwise, and the temperature was raised to 80-85°C and polymerization reaction was carried out under nitrogen atmosphere for 12-24 hours. After cooling to room temperature, the above reaction solution was added dropwise to a sufficient amount (500 mL) of cold ether to precipitate a white solid. After filtering, the precipitate was dried in a vacuum drying oven at 45-50°C for 24 hours to obtain terminal hydroxyl polyvinylpyrrolidone.

[0013] Furthermore, the usage ratio of azobisisobutyronitrile, N,N-dimethylformamide, N-vinylpyrrolidone and mercaptoethanol is 170 mg: 50 mL: 11 mL: 0.28-0.35 mL.

[0014] Furthermore, the bishydroxy-terminated fluorinated polysiloxane is bishydroxy-terminated polymethyltrifluoropropylsiloxane.

[0015] Furthermore, the antifouling agent is prepared by the following steps:

[0016] Piperazine and polyvinyl pyrrolidone are added to deionized water and stirred to dissolve to obtain an aqueous phase; 4,5-dichloro-2-n-octyl 4-isothiazoline-3-one (DCOIT) and trimesoyl chloride are added to n-hexane and stirred to dissolve to obtain an oil phase; the oil phase is added dropwise to the aqueous phase at a stirring speed of 800-1000 r / min to form an oil-in-water emulsion, reacted at room temperature for 3-5 minutes, centrifuged, washed with deionized water, and dried in a vacuum drying oven at 45°C to constant weight to obtain an antifouling agent. DCOIT is encapsulated in a polypiperazineamide shell by utilizing the rapid polycondensation reaction of piperazine and trimesoyl chloride at the interface between the oil phase and the aqueous phase. By doping low molecular weight polyvinyl pyrrolidone in the aqueous phase, polyvinyl pyrrolidone as a surfactant promotes piperazine to enter the oil phase interface for reaction without affecting the viscosity of the aqueous phase. At the same time, polyvinyl pyrrolidone can also participate in the above reaction, thereby increasing the shell thickness and improving the hydrophilicity of the antifouling agent.

[0017] Furthermore, the usage ratio of piperazine, polyvinyl pyrrolidone and deionized water is 2g:1-2g:500mL; the usage ratio of DCOIT, trimesoyl chloride and n-hexane is 2.5g:50-60mg:10mL; and the volume ratio of the oil phase to the water phase is 1:50.

[0018] Furthermore, the weight average molecular weight of the polyvinyl pyrrolidone is 10000. Low molecular weight and low dosage polyvinyl pyrrolidone will not affect the viscosity of the water phase.

[0019] A method for preparing an organosilicon-based antifouling coating comprises the following steps:

[0020] The above-mentioned parts by weight of dihydroxy-terminated polydimethylsiloxane, functionalized polyvinyl pyrrolidone and dihydroxy-terminated fluorinated polysiloxane are dissolved in tetrahydrofuran, and then an antifouling agent, fumed silica, ethyl orthosilicate and stannous octoate are added, and the mixture is stirred and mixed at room temperature for 30-60 minutes to obtain an organosilicon-based antifouling coating.

[0021] Beneficial effects:

[0022] The invention uses mercaptoethanol as a chain transfer agent and azobisisobutyronitrile as an initiator, synthesizes N-vinyl pyrrolidone into hydroxy-terminated polyvinyl pyrrolidone by a free radical polymerization method in a DMF solvent, then functionalizes the hydroxy-terminated polyvinyl pyrrolidone and isocyanate-containing polysiloxane with triethoxysilane to obtain functionalized polyvinyl pyrrolidone; then, the amphiphilic functionalized polyvinyl pyrrolidone and low-surface-energy hydroxy-terminated polytrifluoropropyl methylsiloxane are compounded and added to dihydroxy-terminated polydimethylsiloxane, and the polyvinyl pyrrolidone long chain and fluorine-containing group are connected to a spatial three-dimensional network structure by cross-linking of alkoxy groups and terminal hydroxy groups at room temperature. On the one hand, the polyvinyl pyrrolidone is fixed in the antifouling coating, giving full play to its amphiphilic effect, effectively reducing the attachment of marine fouling organisms, and will not be released into the seawater, which is more environmentally friendly. On the other hand, the hydroxy-terminated polytrifluoropropyl methylsiloxane can further reduce the surface energy of the coating formed by the coating, and synergistically with the polyvinyl pyrrolidone to further reduce the adhesion of marine fouling organisms.

[0023] The invention utilizes the rapid polycondensation reaction of piperazine and trimesoyl chloride at the interface of the oil phase and the water phase to form a polypiperazineamide shell with a nanopore structure, and in the reaction process, the polypiperazineamide shell is formed by diffusion from the water phase to the oil phase, so that DCOIT is tightly encapsulated in the polypiperazineamide shell, and the sustained and slow release of DCOIT in seawater can be achieved, and the growth and reproduction of fine fouling organisms such as algae and bacteria can be effectively inhibited for a long time, thereby ensuring that the antifouling coating has a long-term and efficient static antifouling effect; by doping low-molecular-weight polyvinyl pyrrolidone in the water phase, the interface reaction speed can be promoted and the hydrophilicity of the antifouling agent can be improved without affecting the viscosity of the water phase, thereby facilitating the improvement of the dispersion uniformity of the antifouling agent in the antifouling coating, and giving full play to the effect of the antifouling agent in inhibiting the growth of microorganisms; in addition, the antifouling agent prepared by the invention has good structural strength and a spherical appearance, and can be added to the antifouling coating to improve the mechanical properties of the coating;

[0024] The organosilicon-based antifouling coating prepared by the present invention can effectively resist the attachment of large-scale fouling organisms at high water flow rates and the adsorption of bacteria and diatoms at low flow rates or in still seawater by combining the two aspects of reducing the adhesion of the coating surface and the growth of fouling organisms on the coating surface, thereby expanding the application scope of the organosilicon-based antifouling coating. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] A functionalized polyvinyl pyrrolidone is prepared by the following steps:

[0028] (1) 170 mg of azobisisobutyronitrile was added to 50 mL of N,N-dimethylformamide and stirred to dissolve, and the mixture was evacuated and nitrogen was introduced to remove oxygen, and then 11 mL of N-vinylpyrrolidone and 0.28 mL of mercaptoethanol were added dropwise, and the mixture was heated to 80° C. and polymerized under a nitrogen atmosphere for 24 h. After cooling to room temperature, the reaction solution was added dropwise to 500 mL of cold ether to precipitate a white solid. After filtering, the precipitate was dried in a vacuum oven at 45° C. for 24 h to obtain hydroxy-terminated polyvinylpyrrolidone;

[0029] (2) 8 g of hydroxy-terminated polyvinyl pyrrolidone was added to 8 mL of tetrahydrofuran and stirred to dissolve, and then 0.8 g of (3-isocyanopropyl)triethoxysilane and 6 mg of dibutyltin dilaurate were added. After stirring and reacting at 60° C. for 3 h, functionalized polyvinyl pyrrolidone was obtained.

[0030] Example 2

[0031] A functionalized polyvinyl pyrrolidone is prepared by the following steps:

[0032] (1) 170 mg of azobisisobutyronitrile was added to 50 mL of N,N-dimethylformamide and stirred to dissolve, and the mixture was evacuated and nitrogen was introduced to remove oxygen, and then 11 mL of N-vinylpyrrolidone and 0.3 mL of mercaptoethanol were added dropwise, and the mixture was heated to 82° C. and polymerized under a nitrogen atmosphere for 18 h. After cooling to room temperature, the reaction solution was added dropwise to 500 mL of cold ether to precipitate a white solid. After filtering, the precipitate was dried in a vacuum oven at 50° C. for 24 h to obtain hydroxy-terminated polyvinylpyrrolidone;

[0033] (2) 8 g of hydroxy-terminated polyvinyl pyrrolidone was added to 9 mL of tetrahydrofuran and stirred to dissolve, and then 0.8 g of (3-isocyanopropyl)triethoxysilane and 6.2 mg of dibutyltin dilaurate were added. After stirring and reacting at 65° C. for 2 h, functionalized polyvinyl pyrrolidone was obtained.

[0034] Example 3

[0035] A functionalized polyvinyl pyrrolidone is prepared by the following steps:

[0036] (1) 170 mg of azobisisobutyronitrile was added to 50 mL of N,N-dimethylformamide and stirred to dissolve, and the mixture was evacuated and nitrogen was introduced to remove oxygen, and then 11 mL of N-vinylpyrrolidone and 0.35 mL of mercaptoethanol were added dropwise, and the mixture was heated to 85° C. and polymerized under a nitrogen atmosphere for 12 h. After cooling to room temperature, the reaction solution was added dropwise to 500 mL of cold ether to precipitate a white solid. After filtering, the precipitate was dried in a vacuum oven at 50° C. for 24 h to obtain hydroxy-terminated polyvinylpyrrolidone;

[0037] (2) 8 g of hydroxy-terminated polyvinyl pyrrolidone was added to 10 mL of tetrahydrofuran and stirred to dissolve, and then 0.8 g of (3-isocyanatopropyl)triethoxysilane and 6.3 mg of dibutyltin dilaurate were added. After stirring and reacting at 65° C. for 2 h, functionalized polyvinyl pyrrolidone was obtained.

[0038] Example 4

[0039] An antifouling agent is prepared by the following steps:

[0040] 2 g of piperazine and 1 g of polyvinyl pyrrolidone with a weight average molecular weight of 10,000 were added to 500 mL of deionized water and stirred to dissolve to obtain an aqueous phase; 2.5 g of DCOIT and 50 mg of trimesoyl chloride were added to 10 mL of n-hexane and stirred to dissolve to obtain an oil phase; the oil phase was added dropwise to the aqueous phase at a stirring speed of 800 r / min to form an oil-in-water emulsion, reacted at room temperature for 3 minutes, centrifuged, washed with deionized water, and dried in a vacuum drying oven at 45°C to constant weight to obtain an antifouling agent.

[0041] Example 5

[0042] An antifouling agent is prepared by the following steps:

[0043] 2 g of piperazine and 1.5 g of polyvinyl pyrrolidone with a weight average molecular weight of 10,000 were added to 500 mL of deionized water and stirred to dissolve to obtain an aqueous phase; 2.5 g of DCOIT and 55 mg of trimesoyl chloride were added to 10 mL of n-hexane and stirred to dissolve to obtain an oil phase; the oil phase was added dropwise to the aqueous phase at a stirring speed of 900 r / min to form an oil-in-water emulsion, reacted at room temperature for 4 minutes, centrifuged, washed with deionized water, and dried in a vacuum drying oven at 45°C to constant weight to obtain an antifouling agent.

[0044] Example 6

[0045] An antifouling agent is prepared by the following steps:

[0046] 2 g of piperazine and 2 g of polyvinyl pyrrolidone with a weight average molecular weight of 10,000 were added to 500 mL of deionized water and stirred to dissolve to obtain an aqueous phase; 2.5 g of DCOIT and 60 mg of trimesoyl chloride were added to 10 mL of n-hexane and stirred to dissolve to obtain an oil phase; the oil phase was added dropwise to the aqueous phase at a stirring speed of 1000 r / min to form an oil-in-water emulsion, reacted at room temperature for 5 minutes, centrifuged, washed with deionized water, and dried in a vacuum drying oven at 45°C to constant weight to obtain an antifouling agent.

[0047] Example 7

[0048] An organosilicon-based antifouling coating comprises the following raw materials in parts by weight:

[0049]

[0050] The preparation method of the organosilicon-based antifouling coating comprises the following steps:

[0051] The above-mentioned weight portions of bishydroxy-terminated polydimethylsiloxane, functionalized polyvinyl pyrrolidone and bishydroxy-terminated polymethyltrifluoropropylsiloxane are dissolved in tetrahydrofuran, and then an antifouling agent, fumed silica, ethyl orthosilicate and stannous octoate are added, and the mixture is stirred and mixed at room temperature for 30 minutes to obtain an organosilicon-based antifouling coating.

[0052] Example 8

[0053] An organosilicon-based antifouling coating comprises the following raw materials in parts by weight:

[0054]

[0055] The preparation method of the organosilicon-based antifouling coating comprises the following steps:

[0056] The above-mentioned weight portions of bishydroxy-terminated polydimethylsiloxane, functionalized polyvinyl pyrrolidone and bishydroxy-terminated polymethyltrifluoropropylsiloxane are dissolved in tetrahydrofuran, and then an antifouling agent, fumed silica, ethyl orthosilicate and stannous octoate are added, and the mixture is stirred and mixed at room temperature for 45 minutes to obtain an organosilicon-based antifouling coating.

[0057] Example 9

[0058] An organosilicon-based antifouling coating comprises the following raw materials in parts by weight:

[0059]

[0060] The preparation method of the organosilicon-based antifouling coating comprises the following steps:

[0061] The above-mentioned weight parts of bishydroxy-terminated polydimethylsiloxane, functionalized polyvinyl pyrrolidone and bishydroxy-terminated polymethyltrifluoropropylsiloxane are dissolved in tetrahydrofuran, and then an antifouling agent, fumed silica, ethyl orthosilicate and stannous octoate are added, and the mixture is stirred and mixed at room temperature for 60 minutes to obtain an organosilicon-based antifouling coating.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 9 is that the functionalized polyvinyl pyrrolidone prepared in Example 3 is replaced by an equal amount of terminal hydroxyl polyvinyl pyrrolidone, and the other raw materials and steps are the same.

[0064] Comparative Example 2

[0065] The difference between this comparative example and Example 9 is that no dihydroxy-terminated polymethyltrifluoropropylsiloxane is added, and the other raw materials and steps are the same.

[0066] Comparative Example 3

[0067] The difference between this comparative example and Example 9 is that an equal amount of DCOIT is used to replace the antifouling agent prepared in Example 6, and the other raw materials and steps are the same.

[0068] Performance tests were performed on Examples 7 to 9 and Comparative Examples 1 to 3. According to GB / T528-2009, a universal testing machine was used to test the tensile strength and elongation at break of dumbbell-shaped coating samples at a loading speed of 500 mm / min. The simulated barnacle desorption performance was tested according to ASTM D5618-2011. The coating was immersed in a shallow sea hanging board according to GB / T 5370-2007. After hanging for 2 months, the fouling organisms and the attached growth of the test samples were observed. The results are shown in Table 1:

[0069] Table 1

[0070]

[0071] It can be seen from the data in Table 1 that the organosilicon-based antifouling coatings prepared in Examples 7 to 9 have appropriate mechanical properties and excellent antifouling properties, especially the antifouling properties in a static state; compared with Comparative Examples 1 and 2, the use of functionalized polyvinyl pyrrolidone and dihydroxy-terminated polymethyltrifluoropropylsiloxane can not only adjust the mechanical properties of the organosilicon-based antifouling coating, but also effectively reduce the adhesion of large and micro fouling organisms; compared with Comparative Example 3, directly adding DCOIT cannot achieve the long-term sustained release effect of the antifouling agent of the present invention, and can maintain a long-term effective antifouling effect in a static seawater environment, and has excellent antifouling performance.

[0072] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0073] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An organosilicon-based antifouling coating, characterized in that: The following raw materials are included by mass:

2. The organosilicon-based antifouling coating according to claim 1, characterized in that: The functionalized polyvinyl pyrrolidone is prepared by the following steps: The terminal hydroxyl polyvinyl pyrrolidone is added into tetrahydrofuran and stirred to be mixed and dissolved, and then (3-isocyanopropyl)triethoxysilane and dibutyltin dilaurate are added, and the mixture is stirred and reacted at 60-65° C. for 2-3 hours to obtain the functionalized polyvinyl pyrrolidone.

3. The organosilicon-based antifouling coating according to claim 2, characterized in that: The usage ratio of the hydroxy-terminated polyvinyl pyrrolidone, tetrahydrofuran, (3-isocyanopropyl)triethoxysilane and dibutyltin dilaurate is 8g: 8-10mL: 0.8g: 6-6.3mg.

4. The organosilicon-based antifouling coating according to claim 2, characterized in that: The hydroxy-terminated polyvinyl pyrrolidone is prepared by the following method: Add azobisisobutyronitrile to N,N-dimethylformamide and stir to dissolve, evacuate and introduce nitrogen at the same time, then add N-vinylpyrrolidone and mercaptoethanol dropwise, raise the temperature to 80-85°C and polymerize under nitrogen atmosphere for 12-24 hours, cool to room temperature, add dropwise into cold ether to precipitate, filter and vacuum dry to obtain terminal hydroxyl polyvinylpyrrolidone.

5. The organosilicon-based antifouling coating according to claim 4, characterized in that: The dosage ratio of azobisisobutyronitrile, N,N-dimethylformamide, N-vinylpyrrolidone and mercaptoethanol is 170 mg: 50 mL: 11 mL: 0.28-0.35 mL.

6. The organosilicon-based antifouling coating according to claim 1, characterized in that: The bishydroxyl-terminated fluorine-containing polysiloxane is bishydroxyl-terminated polymethyltrifluoropropylsiloxane.

7. The organosilicon-based antifouling coating according to claim 1, characterized in that: The antifouling agent is prepared by the following steps: Add piperazine and polyvinyl pyrrolidone into deionized water and stir to dissolve to obtain an aqueous phase; add 4,5-dichloro-2-octyl-4-isothiazoline-3-one and trimesoyl chloride into n-hexane and stir to dissolve to obtain an oil phase; add the oil phase dropwise into the stirred aqueous phase to form an oil-in-water emulsion, react at room temperature for 3-5 minutes, centrifuge, wash with deionized water, and vacuum dry to constant weight to obtain an antifouling agent.

8. The organosilicon-based antifouling coating according to claim 7, characterized in that: The usage ratio of piperazine, polyvinyl pyrrolidone and deionized water is 2g:1-2g:500mL; the usage ratio of 4,5-dichloro-2-octyl-4-isothiazoline-3-one, trimesoyl chloride and n-hexane is 2.5g:50-60mg:10mL; the volume ratio of the oil phase to the water phase is 1:

50.

9. The organosilicon-based antifouling coating according to claim 7, characterized in that: The weight average molecular weight of the polyvinyl pyrrolidone is 10,000.

10. The method for preparing an organosilicon-based antifouling coating according to claim 1, characterized in that: The following steps are involved: Dissolve dihydroxy-terminated polydimethylsiloxane, functionalized polyvinyl pyrrolidone and dihydroxy-terminated fluorinated polysiloxane in tetrahydrofuran, add antifouling agent, fumed silica, ethyl orthosilicate and stannous octoate, and stir and mix at room temperature for 30-60 minutes to obtain an organosilicon-based antifouling coating.

Images