Fluorosilicone-modified low-surface-energy antifouling coating and preparation method therefor

Abstract

Disclosed in the present invention are a fluorosilicone-modified low-surface-energy antifouling coating and a preparation method therefor. The coating comprises the following components in parts by weight: 11-15 parts of butyl acrylate, 3-4 parts of dodecafluoroheptyl methacrylate, 3-4 parts of vinyl-terminated polydimethylsiloxane, 3-4 parts of 2-hydroxy-4-acryloyloxybenzophenone, 30-38 parts of methyl isobutyl ketone, 0.15-0.25 parts of azobisisobutyronitrile, 0.1-0.2 parts of sodium hydroxide, 2-3 parts of modified titanium dioxide nanoparticles, and 0.5-1.5 parts of 3-aminopropyltriethoxysilane. In the present invention, vinylpentamethyldisiloxane reacts with decamethylcyclopentasiloxane to prepare vinyl-terminated polydimethylsiloxane; a titanium dioxide precursor is mixed with polydopamine nanoparticles for modification to prepare modified titanium dioxide nanoparticles; and then the components above are mixed to prepare the fluorosilicone-modified low-surface-energy antifouling coating. The coating has low surface energy and good adhesion and ultraviolet resistance.

Description

Fluorine-silicon modified low surface energy antifouling coating and preparation method thereof TECHNICAL FIELD

[0001] The present application relates to the field of coating technology, and in particular to a fluorine-silicon modified low surface energy antifouling coating and a preparation method thereof. BACKGROUND

[0002] Surface energy refers to the difference between the energy of surface molecules and the energy of bulk phase molecules under thermal equilibrium, reflecting the degree of interaction between surface molecules and external media. Low surface energy can prevent the initial attachment of marine organisms, which is the most important step in preventing marine biofouling. Low surface energy marine antifouling coating can make marine fouling organisms difficult to attach to the surface of the ship body, and even if they attach, they are not firm and can easily fall off under the action of water flow or other external forces. Therefore, such coating is also called non-stick coating or fouling shedding type coating. Since such coating uses the physical property of low surface energy to achieve antifouling effect, it is a non-toxic and environmentally friendly antifouling coating. Low surface energy antifouling coating reduces surface energy by using organic fluorine or organic silicon, and is commonly used in marine vessels.

[0003] At present, low surface energy antifouling coating still has some deficiencies, which limits its wide application: (1) the adhesion of low surface energy antifouling coating to the bottom of the ship is poor, and it is usually difficult to combine with the substrate; (2) the molecular structure and intermolecular force of organic silicon resin are small, and the effective crosslinking density is low, resulting in poor mechanical properties; (3) the service life of the coating is not long, and with the passage of time, it is deteriorated due to the action of ultraviolet light, sunlight and pollutants. Therefore, it is necessary to modify it so that it can be more widely applied to the field of marine antifouling coating. SUMMARY

[0004] The present application provides a fluorine-silicon modified low surface energy antifouling coating and a preparation method thereof to solve the above technical problems.

[0005] In the first aspect, the present application provides a fluorine-silicon modified low surface energy antifouling coating, which is realized by the following technical scheme.

[0006] A fluorine-silicon modified low surface energy antifouling coating comprises the following components by weight: butyl acrylate 11-15 parts, methyl dodecafluoroheptyl methacrylate 3-4 parts, vinyl-terminated polydimethylsilane 3-4 parts, 2-hydroxy-4-acryloyloxybenzophenone 3-4 parts, methyl isobutyl ketone 30-38 parts, azobis isobutyronitrile 0.15-0.25 parts, sodium hydroxide 0.1-0.2 parts, modified titanium dioxide nanoparticles 2-3 parts, and 3-aminopropyl triethoxysilane 0.5-1.5 parts.

[0007] Further, the end-vinyl polydimethylsilane is prepared by reacting vinyl pentamethyl disiloxane and decamethyl cyclopentasiloxane.

[0008] Further, the end-vinyl polydimethylsilane is prepared by reacting vinyl pentamethyl disiloxane and decamethyl cyclopentasiloxane.

[0009] Further, the modified titanium dioxide nanoparticles are prepared by hydrolysis and self-polymerization of tetrabutyl titanate to obtain a titanium dioxide precursor, and mixing and modifying the titanium dioxide precursor and polydopamine nanoparticles to obtain the modified titanium dioxide nanoparticles.

[0010] Further, the modified titanium dioxide nanoparticles are prepared by hydrolysis and self-polymerization of tetrabutyl titanate to obtain a titanium dioxide precursor, and mixing and modifying the titanium dioxide precursor and polydopamine nanoparticles to obtain the modified titanium dioxide nanoparticles.

[0011] Further, the modified titanium dioxide nanoparticles are prepared by hydrolysis and self-polymerization of tetrabutyl titanate to obtain a titanium dioxide precursor, and mixing and modifying the titanium dioxide precursor and polydopamine nanoparticles to obtain the modified titanium dioxide nanoparticles.

[0012] Further, the modified titanium dioxide nanoparticles are prepared by hydrolysis and self-polymerization of tetrabutyl titanate to obtain a titanium dioxide precursor, and mixing and modifying the titanium dioxide precursor and polydopamine nanoparticles to obtain the modified titanium dioxide nanoparticles.

[0013] In a second aspect, the present application provides a preparation method of fluorine-silicon modified low surface energy antifouling paint, which is achieved by using the following technical scheme.

[0014] The preparation method of the fluorine-silicon modified low surface energy antifouling paint comprises the following steps: uniformly mixing a specified amount of butyl acrylate, dodecafluoroheptyl methacrylate, end-vinyl polydimethylsilane, 2-hydroxy-4-acryloyloxy benzophenone and methyl isobutyl ketone, under the condition of 70-80 DEG C and 200-300 r / min stirring, adding azobis isobutyronitrile at a uniform speed within 80-100 min, keeping the temperature unchanged after the addition is completed, continuing to stir for 3-4 h, then adding sodium hydroxide, modified titanium dioxide nanoparticles and 3-aminopropyl triethoxysilane and continuing to stir for 3-5 min, thereby obtaining the fluorine-silicon modified low surface energy antifouling paint.

[0015] In use, the fluorine-silicon modified low surface energy antifouling paint is coated on the surface of a metal substrate, and is then placed at 80 DEG C for 6-8 h, naturally cooled to room temperature and placed for 10-12 h.

[0016] The present application has the following beneficial effects.

[0017] (1) The end-vinyl polydimethylsilane is prepared by reacting vinyl pentamethyl disiloxane and decamethylcyclopentasiloxane, and the addition of dodecafluoroheptyl methacrylate and end-vinyl polydimethylsilane can better reduce the overall surface energy, wherein the addition of dodecafluoroheptyl methacrylate and end-vinyl polydimethylsilane can improve the hydrophobic property, the addition of dodecafluoroheptyl methacrylate can effectively improve the oil-repellent property, the overall has better antifouling effect, the addition of 2-hydroxy-4-acryloyloxy benzophenone improves the overall ultraviolet resistance, and the addition of 3-aminopropyl triethoxysilane improves the adhesion.

[0018] (2) The modified titanium dioxide nanoparticles are prepared by hydrolysis and self-polymerization of tetrabutyl titanate to obtain a titanium dioxide precursor, mixing the titanium dioxide precursor and polydopamine nanoparticles to modify and obtain the modified titanium dioxide nanoparticles, which improves the compatibility of the modified titanium dioxide nanoparticles with the inorganic main body, the amino group, imino group and phenolic hydroxyl group on the polydopamine can react with the epoxy group to form a crosslinked network structure, thereby improving the mechanical properties, and the polydopamine has good ultraviolet absorption effect. DETAILED DESCRIPTION

[0019] The technical scheme of the present application will be clearly and completely described below through a specific embodiment.

[0020] The CAS of the vinyl pentamethyl disiloxane in the present application is 1438-79-5.

[0021] Example 1

[0022] A preparation method of a fluorosilicon modified low surface energy antifouling coating mainly comprises the following preparation steps:

[0023] (1) uniformly mix dopamine hydrochloride and deionized water according to a mass ratio of 1:300, then drop 0.3 times the mass of dopamine hydrochloride of 1 mol / L sodium hydroxide solution, stir at 50℃ and 200 r / min for 5h, centrifugal separation and washing with pure water for 3 times, drying at 50℃ and 50Pa for 12h, to prepare polydopamine nanoparticles;

[0024] (2) uniformly mix anhydrous ethanol, pure water and isopropyl alcohol according to a mass ratio of 2:1:10, under the condition of stirring at room temperature and 200 r / min, add 0.2 times the mass of anhydrous ethanol of tetrabutyl titanate at a uniform speed within 3min, continue to stir for 40min, centrifugal separation and washing with pure water for 3 times, drying at 50℃ and 50Pa for 12h, to prepare titanium dioxide precursor; uniformly mix titanium dioxide precursor and pure water according to a mass ratio of 1:100, add polydopamine nanoparticles with the same mass as the titanium dioxide precursor, adjust the pH to 1 with 1 mol / L hydrochloric acid solution, stir at 80℃ and 200 r / min for 12h, continue to stir at 50℃ for 5h, adjust the pH to 7 with 1 mol / L sodium hydroxide solution, centrifugal separation and washing with pure water for 3 times, drying at 50℃ and 50Pa for 12h, to prepare modified titanium dioxide nanoparticles;

[0025] (3) uniformly mix vinyl pentamethyl disiloxane, decamethylcyclopentasiloxane and 98% mass fraction sulfuric acid solution according to a mass ratio of 1:3:0.03, stir at 40℃ and 200 r / min for 10h, then add sodium bicarbonate to adjust the pH to 7, filter and dry at 110℃ and 50Pa for 12h, to prepare terminal vinyl polydimethylsilane;

[0026] (4) by mass butyl acrylate 73.33g, methacrylic acid dodecafluoroheptyl ester 20g, vinyl-terminated polydimethylsilane 20g, 2-hydroxy-4-acryloyloxy benzophenone 20g, methyl isobutyl ketone 200g, azobisisobutyronitrile 1g, sodium hydroxide 0.67g, modified titanium dioxide nanoparticles 13.33g, 3-aminopropyl triethoxysilane 6.67g; in a nitrogen atmosphere, butyl acrylate, methacrylic acid dodecafluoroheptyl ester, vinyl-terminated polydimethylsilane, 2-hydroxy-4-acryloyloxy benzophenone, methyl isobutyl ketone were mixed uniformly, azobisisobutyronitrile was added at a constant speed under the condition of 70℃ and 200r / min stirring for 80min, after the addition, the temperature was kept unchanged and stirring was continued for 3h, then sodium hydroxide, modified titanium dioxide nanoparticles and 3-aminopropyl triethoxysilane were added and stirring was continued for 3min, to obtain fluorosilicon modified low surface energy antifouling coating.

[0027] Example 2

[0028] A preparation method of a fluorosilicon modified low surface energy antifouling coating mainly includes the following preparation steps:

[0029] (1) hydrochloric acid dopamine and deionized water were mixed uniformly according to the mass ratio of 1:350, then 1mol / L sodium hydroxide solution with a mass of 0.4 times that of hydrochloric acid dopamine was added dropwise, stirring was carried out at 55℃ and 250r / min for 4.5h, centrifugal separation was carried out and washing was carried out with pure water for 4 times, drying was carried out at 55℃ and 70Pa for 11h, to prepare polydopamine nanoparticles;

[0030] (2) anhydrous ethanol, pure water and isopropyl alcohol were mixed uniformly according to the mass ratio of 2:1:11, titanium tetrabutoxide with a mass of 0.25 times that of anhydrous ethanol was added at a constant speed under the condition of room temperature and 250r / min stirring for 4min, stirring reaction was continued for 35min, centrifugal separation was carried out and washing was carried out with pure water for 4 times, drying was carried out at 55℃ and 70Pa for 11h, to prepare titanium dioxide precursor; the titanium dioxide precursor and pure water were mixed uniformly according to the mass ratio of 1:110, polydopamine nanoparticles with the same mass as the titanium dioxide precursor were added, 1mol / L hydrochloric acid solution was used to adjust the pH to 1.5, stirring was carried out at 82℃ and 250r / min for 11h, the temperature was lowered to 52℃ and stirring reaction was continued for 4.5h, 1mol / L sodium hydroxide solution was used to adjust the pH to 7.5, centrifugal separation was carried out and washing was carried out with pure water for 4 times, drying was carried out at 55℃ and 70Pa for 11h, to prepare modified titanium dioxide nanoparticles;

[0031] (3) mixing vinyl pentamethyl disiloxane, decamethyl cyclopentasiloxane and 98% mass fraction sulfuric acid solution uniformly according to a mass ratio of 1:3.5:0.035, stirring at 45°C and 250r / min for 9h, then adding sodium bicarbonate to adjust pH to 7, filtering and drying at 115°C and 70Pa for 11h to obtain vinyl terminated polydimethylsilane;

[0032] (4) weighing butyl acrylate 76.47g, dodecafluoroheptyl methacrylate 20.59g, vinyl terminated polydimethylsilane 20.59g, 2-hydroxy-4-acryloyloxy benzophenone 20.59g, methyl isobutyl ketone 200g, azobis isobutyronitrile 1.18g, sodium hydroxide 0.88g, modified titanium dioxide nanoparticles 14.71g, 3-aminopropyl triethoxysilane 5.88g; mixing butyl acrylate, dodecafluoroheptyl methacrylate, vinyl terminated polydimethylsilane, 2-hydroxy-4-acryloyloxy benzophenone and methyl isobutyl ketone uniformly in a nitrogen atmosphere, adding azobis isobutyronitrile uniformly at 75°C and 250r / min for 90min, keeping the temperature unchanged and stirring for 3.5h after the addition, then adding sodium hydroxide, modified titanium dioxide nanoparticles and 3-aminopropyl triethoxysilane and stirring for 4min to obtain fluorine-silicon modified low surface energy anti-fouling coating.

[0033] Example 3

[0034] A preparation method of a fluorine-silicon modified low surface energy anti-fouling coating mainly includes the following preparation steps:

[0035] (1) mixing dopamine hydrochloride and deionized water uniformly according to a mass ratio of 1:400, then adding 1mol / L sodium hydroxide solution with a mass of 0.5 times that of dopamine hydrochloride, stirring at 60°C and 300r / min for 4h, centrifuging and washing with pure water for 5 times, and drying at 60°C and 100Pa for 10h to obtain polydopamine nanoparticles;

[0036] (2) mixing anhydrous ethanol, pure water and isopropyl alcohol uniformly according to a mass ratio of 2:1:12, adding titanium tetrabutoxide with a mass of 0.2 times that of the anhydrous ethanol at a uniform speed within 5 min under the condition of room temperature and 300 r / min stirring, continuing to stir for 30 min, centrifuging and washing with pure water for 5 times, drying at 60℃ and 100 Pa for 10 h, to obtain a titanium dioxide precursor; mixing the titanium dioxide precursor and pure water uniformly according to a mass ratio of 1:120, adding polydopamine nanoparticles with the same mass as the titanium dioxide precursor, adjusting the pH to 2 with a 1 mol / L hydrochloric acid solution, stirring at 300 r / min under reflux at 85℃ for 10 h, continuing to stir at 55℃ for 4 h, adjusting the pH to 8 with a 1 mol / L sodium hydroxide solution, centrifuging and washing with pure water for 5 times, drying at 60℃ and 100 Pa for 10 h, to obtain modified titanium dioxide nanoparticles;

[0037] (3) mixing vinyl pentamethyl disiloxane, decamethylcyclopentasiloxane and a mass fraction of 98% sulfuric acid solution uniformly according to a mass ratio of 1:4:0.04, stirring at 300 r / min at 50℃ for 8 h, adjusting the pH to 7 by adding sodium bicarbonate, filtering and drying at 120℃ and 100 Pa for 10 h, to obtain a terminal vinyl polydimethylsilane;

[0038] (4) weighing butyl acrylate 78.95 g, dodecafluoroheptyl methacrylate 21.05 g, terminal vinyl polydimethylsilane 21.05 g, 2-hydroxy-4-acryloyloxy benzophenone 21.05 g, methyl isobutyl ketone 200 g, azobis isobutyronitrile 1.32 g, sodium hydroxide 1.05 g, modified titanium dioxide nanoparticles 15.79 g, 3-aminopropyl triethoxysilane 5.26 g; mixing butyl acrylate, dodecafluoroheptyl methacrylate, terminal vinyl polydimethylsilane, 2-hydroxy-4-acryloyloxy benzophenone and methyl isobutyl ketone uniformly under a nitrogen atmosphere, adding azobis isobutyronitrile at a uniform speed within 100 min under the condition of 80℃ and 300 r / min stirring, keeping the temperature unchanged for 3 h after the addition is completed, and then adding sodium hydroxide, modified titanium dioxide nanoparticles and 3-aminopropyl triethoxysilane and continuing to stir for 5 min, to obtain a fluorosilicon modified low surface energy antifouling coating.

[0039] Comparative Example 1

[0040] A preparation method of a fluorosilicon modified low surface energy antifouling coating mainly includes the following preparation steps:

[0041] (1) mixing anhydrous ethanol, pure water and isopropyl alcohol uniformly according to a mass ratio of 2:1:11, adding tetrabutyl titanate with a mass of 0.25 times that of the anhydrous ethanol at a uniform speed within 4 min under the condition of room temperature and 250 r / min stirring, continuing to stir for 35 min, centrifuging and washing with pure water for 4 times, and drying at 55℃ and 70 Pa for 11 h to prepare titanium dioxide nanoparticles;

[0042] (2) mixing vinyl pentamethyl disiloxane, decamethylcyclopentasiloxane and a mass fraction of 98% sulfuric acid solution uniformly according to a mass ratio of 1:3.5:0.035, stirring at 45℃ and 250 r / min for 9 h, adding sodium bicarbonate to adjust the pH to 7, filtering and drying at 115℃ and 70 Pa for 11 h to prepare end-vinyl polydimethylsilane;

[0043] (3) weighing butyl acrylate 76.47 g, dodecafluoroheptyl methacrylate 20.59 g, end-vinyl polydimethylsilane 20.59 g, 2-hydroxy-4-acryloyloxy benzophenone 20.59 g, methyl isobutyl ketone 200 g, azobis isobutyronitrile 1.18 g, sodium hydroxide 0.88 g, titanium dioxide nanoparticles 14.71 g, and 3-aminopropyl triethoxysilane 5.88 g; mixing butyl acrylate, dodecafluoroheptyl methacrylate, end-vinyl polydimethylsilane, 2-hydroxy-4-acryloyloxy benzophenone and methyl isobutyl ketone uniformly under a nitrogen atmosphere, adding azobis isobutyronitrile at a uniform speed within 90 min under the condition of 75℃ and 250 r / min stirring, keeping the temperature unchanged for 3.5 h after the addition is completed, and then adding sodium hydroxide, titanium dioxide nanoparticles and 3-aminopropyl triethoxysilane and stirring for 4 min to obtain fluorosilicon modified low surface energy antifouling coating.

[0044] Comparative Example 2

[0045] A preparation method of a fluorosilicon modified low surface energy antifouling coating mainly includes the following preparation steps:

[0046] (1) mixing dopamine hydrochloride and deionized water uniformly according to a mass ratio of 1:350, adding 1 mol / L sodium hydroxide solution with a mass of 0.4 times that of the dopamine hydrochloride dropwise, stirring at 55℃ and 250 r / min for 4.5 h, centrifuging and washing with pure water for 4 times, and drying at 55℃ and 70 Pa for 11 h to prepare polydopamine nanoparticles;

[0047] (2) mixing anhydrous ethanol, pure water and isopropyl alcohol uniformly according to a mass ratio of 2:1:11, adding tetrabutyl titanate with a mass of 0.25 times that of the anhydrous ethanol at a uniform speed within 4 min under the condition of room temperature and 250 r / min stirring, continuing to stir and react for 35 min, centrifugally separating and washing with pure water for 4 times, drying at 55℃ and 70 Pa for 11 h, to obtain a titanium dioxide precursor; mixing the titanium dioxide precursor and pure water uniformly according to a mass ratio of 1:110, adding polydopamine nanoparticles with a mass equal to that of the titanium dioxide precursor, adjusting the pH to 1.5 with a 1 mol / L hydrochloric acid solution, refluxing at 82℃ and 250 r / min stirring for 11 h, continuing to stir and react for 4.5 h after cooling to 52℃, adjusting the pH to 7.5 with a 1 mol / L sodium hydroxide solution, centrifugally separating and washing with pure water for 4 times, and drying at 55℃ and 70 Pa for 11 h, to obtain modified titanium dioxide nanoparticles;

[0048] (3) weighing butyl acrylate 76.47 g, dodecafluoroheptyl methacrylate 41.18 g, 2-hydroxy-4-acryloyloxybenzophenone 20.59 g, methyl isobutyl ketone 200 g, azobis isobutyronitrile 1.18 g, sodium hydroxide 0.88 g, modified titanium dioxide nanoparticles 14.71 g, and 3-aminopropyl triethoxysilane 5.88 g; mixing butyl acrylate, dodecafluoroheptyl methacrylate, 2-hydroxy-4-acryloyloxybenzophenone and methyl isobutyl ketone uniformly under a nitrogen atmosphere, adding azobis isobutyronitrile at a uniform speed within 90 min under the condition of 75℃ and 250 r / min stirring, continuing to stir for 3.5 h after keeping the temperature unchanged after the addition is completed, and then adding sodium hydroxide, modified titanium dioxide nanoparticles and 3-aminopropyl triethoxysilane and continuing to stir for 4 min, to obtain fluorosilicon modified low surface energy antifouling coating.

[0049] Comparative Example 3

[0050] A preparation method of a fluorosilicon modified low surface energy antifouling coating mainly includes the following preparation steps:

[0051] (1) mixing dopamine hydrochloride and deionized water uniformly according to a mass ratio of 1:350, adding 1 mol / L sodium hydroxide solution with a mass of 0.4 times that of the dopamine hydrochloride dropwise, stirring and reacting at 55℃ and 250 r / min for 4.5 h, centrifugally separating and washing with pure water for 4 times, and drying at 55℃ and 70 Pa for 11 h, to obtain polydopamine nanoparticles;

[0052] (2) mixed anhydrous ethanol, pure water and isopropyl alcohol in a mass ratio of 2:1:11 uniformly, under the condition of room temperature and 250 r / min stirring, added tetrabutyl titanate with a mass of 0.25 times of anhydrous ethanol at a uniform speed within 4 min, continued to stir for 35 min, centrifuged and washed with pure water for 4 times, dried at 55℃ and 70 Pa for 11 h, to obtain titanium dioxide precursor; mixed the titanium dioxide precursor and pure water in a mass ratio of 1:110 uniformly, added polydopamine nanoparticles with the same mass of the titanium dioxide precursor, adjusted the pH to 1.5 with 1 mol / L hydrochloric acid solution, stirred at 82℃ and 250 r / min for 11 h, continued to stir at 52℃ for 4.5 h, adjusted the pH to 7.5 with 1 mol / L sodium hydroxide solution, centrifuged and washed with pure water for 4 times, dried at 55℃ and 70 Pa for 11 h, to obtain modified titanium dioxide nanoparticles;

[0053] (3) mixed vinyl pentamethyl disiloxane, decamethylcyclopentasiloxane and 98% mass fraction sulfuric acid solution in a mass ratio of 1:3.5:0.035 uniformly, stirred at 45℃ and 250 r / min for 9 h, added sodium bicarbonate to adjust the pH to 7, filtered and dried at 115℃ and 70 Pa for 11 h, to obtain vinyl-terminated polydimethylsilane;

[0054] (4) weighed butyl acrylate 76.47 g, vinyl-terminated polydimethylsilane 41.18 g, 2-hydroxy-4-acryloyloxybenzophenone 20.59 g, methyl isobutyl ketone 200 g, azobisisobutyronitrile 1.18 g, sodium hydroxide 0.88 g, modified titanium dioxide nanoparticles 14.71 g, and 3-aminopropyl triethoxysilane 5.88 g; mixed butyl acrylate, vinyl-terminated polydimethylsilane, 2-hydroxy-4-acryloyloxybenzophenone and methyl isobutyl ketone uniformly in a nitrogen atmosphere, added azobisisobutyronitrile at a uniform speed within 90 min under the condition of 75℃ and 250 r / min stirring, kept the temperature unchanged and continued to stir for 3.5 h after the addition was completed, then added sodium hydroxide, modified titanium dioxide nanoparticles and 3-aminopropyl triethoxysilane and continued to stir for 4 min, to obtain fluorosilicon modified low surface energy antifouling coating.

[0055] Comparative Example 4

[0056] A preparation method of a fluorosilicon modified low surface energy antifouling coating mainly includes the following preparation steps:

[0057] (1) mixed hydrochloric acid dopamine and deionized water in a mass ratio of 1:350 uniformly, then added 1 mol / L sodium hydroxide solution with a mass of 0.4 times of hydrochloric acid dopamine, stirred at 55℃ and 250 r / min for 4.5 h, centrifuged and washed with pure water for 4 times, dried at 55℃ and 70 Pa for 11 h, to obtain polydopamine nanoparticles.

[0058] (2) mixing anhydrous ethanol, pure water and isopropyl alcohol uniformly according to a mass ratio of 2:1:11, adding tetrabutyl titanate with a mass of 0.25 times that of the anhydrous ethanol at a uniform speed within 4 min under the condition of room temperature and 250 r / min stirring, continuing to stir for 35 min, centrifugal separation and washing with pure water for 4 times, drying at 55℃ and 70 Pa for 11 h, to obtain a titanium dioxide precursor; mixing the titanium dioxide precursor and pure water uniformly according to a mass ratio of 1:110, adding polydopamine nanoparticles with a mass equal to that of the titanium dioxide precursor, adjusting the pH to 1.5 with a 1 mol / L hydrochloric acid solution, stirring at 82℃ and 250 r / min for 11 h, continuing to stir at 52℃ for 4.5 h, adjusting the pH to 7.5 with a 1 mol / L sodium hydroxide solution, centrifugal separation and washing with pure water for 4 times, drying at 55℃ and 70 Pa for 11 h, to obtain modified titanium dioxide nanoparticles;

[0059] (3) mixing vinyl pentamethyl disiloxane, decamethylcyclopentasiloxane and a 98% mass fraction sulfuric acid solution uniformly according to a mass ratio of 1:3.5:0.035, stirring at 45℃ and 250 r / min for 9 h, adding sodium bicarbonate to adjust the pH to 7, filtering and drying at 115℃ and 70 Pa for 11 h, to obtain a terminal vinyl polydimethylsilane;

[0060] (4) weighing butyl acrylate 76.47 g, dodecafluoroheptyl methacrylate 20.59 g, terminal vinyl polydimethylsilane 20.59 g, methyl isobutyl ketone 200 g, azobis isobutyronitrile 1.18 g, sodium hydroxide 0.88 g, modified titanium dioxide nanoparticles 14.71 g, and 3-aminopropyl triethoxysilane 5.88 g; mixing butyl acrylate, dodecafluoroheptyl methacrylate, terminal vinyl polydimethylsilane and methyl isobutyl ketone uniformly in a nitrogen atmosphere, adding azobis isobutyronitrile at a uniform speed within 90 min under the condition of 75℃ and 250 r / min stirring, continuing to stir for 3.5 h after keeping the temperature unchanged after the addition is completed, and then adding sodium hydroxide, modified titanium dioxide nanoparticles and 3-aminopropyl triethoxysilane and continuing to stir for 4 min, to obtain a fluorosilicon modified low surface energy antifouling coating.

[0061] Comparative Example 5

[0062] A preparation method of a fluorosilicon modified low surface energy antifouling coating mainly includes the following preparation steps:

[0063] (1)Dopamine hydrochloride and deionized water were mixed uniformly at a mass ratio of 1:350, and 0.4 times the mass of dopamine hydrochloride of 1 mol / L sodium hydroxide solution was added dropwise. The reaction was carried out at 55°C with stirring at 250 r / min for 4.5 h. Centrifugal separation and washing with pure water were performed 4 times, and drying was carried out at 55°C and 70 Pa for 11 h to prepare polydopamine nanoparticles;

[0064] (2) Anhydrous ethanol, pure water and isopropyl alcohol were mixed uniformly at a mass ratio of 2:1:11. Under the condition of stirring at 250 r / min at room temperature, 0.25 times the mass of anhydrous ethanol of tetrabutyl titanate was added uniformly within 4 min. The reaction was continued to be stirred for 35 min. Centrifugal separation and washing with pure water were performed 4 times. Drying was carried out at 55°C and 70 Pa for 11 h to prepare titanium dioxide precursor. The titanium dioxide precursor and pure water were mixed uniformly at a mass ratio of 1:110. After adding polydopamine nanoparticles with the same mass as the titanium dioxide precursor, 1 mol / L hydrochloric acid solution was added to adjust the pH to 1.5. The reaction was carried out at 82°C with stirring at 250 r / min for 11 h. The temperature was lowered to 52°C, and the reaction was continued to be stirred for 4.5 h. 1 mol / L sodium hydroxide solution was added to adjust the pH to 7.5. Centrifugal separation and washing with pure water were performed 4 times. Drying was carried out at 55°C and 70 Pa for 11 h to prepare modified titanium dioxide nanoparticles;

[0065] (3) Vinyl pentamethyl disiloxane, decamethylcyclopentasiloxane and 98% sulfuric acid solution were mixed uniformly at a mass ratio of 1:3.5:0.035. The reaction was carried out at 45°C with stirring at 250 r / min for 9 h. Sodium bicarbonate was added to adjust the pH to 7. Filtration and drying were carried out at 115°C and 70 Pa for 11 h to prepare vinyl-terminated polydimethylsilane;

[0066] (4) Butyl acrylate 76.47 g, dodecafluoroheptyl methacrylate 20.59 g, vinyl-terminated polydimethylsilane 20.59 g, 2-hydroxy-4-acryloyloxybenzophenone 20.59 g, methyl isobutyl ketone 200 g, azobisisobutyronitrile 1.18 g, sodium hydroxide 0.88 g, and modified titanium dioxide nanoparticles 14.71 g were weighed by mass. In a nitrogen atmosphere, butyl acrylate, dodecafluoroheptyl methacrylate, vinyl-terminated polydimethylsilane, 2-hydroxy-4-acryloyloxybenzophenone, and methyl isobutyl ketone were mixed uniformly. Under the condition of stirring at 250 r / min at 75°C, azobisisobutyronitrile was added uniformly within 90 min. After the addition was completed, the temperature was kept unchanged, and the stirring was continued for 3.5 h. Sodium hydroxide and modified titanium dioxide nanoparticles were added and the stirring was continued for 4 min to obtain fluorine-silicon modified low surface energy antifouling coating.

[0067] Performance detection

[0068] (1) Surface energy test

[0069] Test method: the fluorosilicon modified low surface energy antifouling coating obtained from each example and comparative example was coated and cured, and then placed on the platform of a contact angle tester, and the contact angles of the coating surface with distilled water and n-hexadecane were measured, respectively. After the coating and the liquid to be tested were in contact for 30 s, the contact angle was tested and recorded. The results are shown in Table 1.

[0070] Table 1

[0071] From the comparison of the experimental data of Examples 1-3 and Comparative Examples 1-5 in Table 1, it can be found that the fluorosilicon modified low surface energy antifouling coating prepared by the present application has a lower surface energy.

[0072] From the comparison of Examples 1-3 and Comparative Examples 2 and 3, it can be found that the addition of dodecafluoroheptyl methacrylate and vinyl-terminated polydimethylsilane can better reduce the overall surface energy. The addition of dodecafluoroheptyl methacrylate and vinyl-terminated polydimethylsilane can improve the hydrophobic property, and the addition of dodecafluoroheptyl methacrylate can effectively improve the oil-repellent property.

[0073] (2) Adhesion test

[0074] Test method: the fluorosilicon modified low surface energy antifouling coating obtained from each example and comparative example was coated and cured on a tinplate, and then the adhesion was tested according to GB / T1720. The results are shown in Table 2.

[0075] Table 2

[0076] From the comparison of the experimental data of Examples 1-3 and Comparative Examples 1-5 in Table 2, it can be found that the fluorosilicon modified low surface energy antifouling coating prepared by the present application has a higher adhesion.

[0077] From the comparison of Examples 1-3 and Comparative Example 5, it can be found that the addition of 3-aminopropyl triethoxysilane can effectively improve the adhesion.

[0078] (3) Tensile strength test

[0079] Test method: according to the GB / T528-92 standard, the fluorosilicon modified low surface energy antifouling coating obtained from each example and comparative example was placed in a mold to cure into a dumbbell-shaped sample, and an intelligent electronic tensile testing machine was used to perform a tensile test on the sample at a tensile rate of 50 mm / min. The results are shown in Table 3.

[0080] (4) Anti-ultraviolet performance test

[0081] Test method: according to the standard of GB / T528-92, the fluorosilicon modified low surface energy antifouling coating obtained in each example and the comparative example was placed in a mold to cure into dumbbell-shaped samples, and the samples were subjected to aging treatment in a UV-263LS ultraviolet aging test box for 3 days, the tensile strength after aging was tested, and the performance retention rate = tensile strength after aging / initial tensile strength was calculated. The results are shown in Table 3.

[0082] Table 3

[0083] From the experimental data comparison of examples 1-3 and comparative examples 1-5 in Table 2, it can be found that the fluorosilicon modified low surface energy antifouling coating prepared by the present application has higher tensile strength and ultraviolet resistance.

[0084] From the comparison of examples 1-3 and comparative example 1, it can be found that the addition of polydopamine improves the compatibility of the modified titanium dioxide nanoparticles with the inorganic matrix, and the amino group, imino group and phenolic hydroxyl group on the polydopamine can react with the epoxy group to form a crosslinked network structure, thereby improving the mechanical properties, and the polydopamine has good ultraviolet absorption effect.

[0085] From the comparison of examples 1-3 and comparative example 2, it can be found that the addition of 2-hydroxy-4-acryloyloxybenzophenone improves the overall ultraviolet resistance.

[0086] The above-described examples are only preferred embodiments of the present application and do not limit the concept and scope of the present application. Without departing from the design concept of the present application, various modifications and improvements of the technical solutions of the present application made by ordinary engineering technicians in the art shall fall within the protection scope of the present application. The technical content claimed by the present application has been fully recorded in the technical requirements.

Claims

1. A fluorosilicon-modified low surface energy antifouling coating, characterized by: The components include the following weight parts: butyl acrylate 11-15 parts, dodecafluoroheptyl methacrylate 3-4 parts, end-vinyl polydimethyl silane 3-4 parts, 2-hydroxy-4-acryloyloxy benzophenone 3-4 parts, methyl isobutyl ketone 30-38 parts, azobis isobutyronitrile 0.15-0.25 parts, sodium hydroxide 0.1-0.2 parts, modified titanium dioxide nanoparticles 2-3 parts, 3-aminopropyl triethoxysilane 0.5-1.5 parts.

2. The fluorosilicon-modified low surface energy antifouling coating according to claim 1, characterized in that: The end-vinyl polydimethyl silane is prepared by reacting vinyl pentamethyl disiloxane and decamethyl cyclopentasiloxane.

3. The fluorosilicon-modified low surface energy antifouling coating according to claim 1 or 2, characterized in that: The end-vinyl polydimethyl silane is prepared by mixing vinyl pentamethyl disiloxane, decamethyl cyclopentasiloxane and a mass fraction 98% sulfuric acid solution in a mass ratio of 1:3-4:0.03-0.04, stirring and reacting at 40-50°C and 200-300 r / min for 8-10 h, adding sodium bicarbonate to adjust the pH to 7, filtering, and drying at 110-120°C and 50-100 Pa for 10-12 h.

4. The fluorosilicone-modified low surface energy antifouling coating according to claim 1, characterized in that: The modified titanium dioxide nanoparticles are prepared by hydrolysis and self-polymerization of tetrabutyl titanate to obtain a titanium dioxide precursor, and mixing and modifying the titanium dioxide precursor and polydopamine nanoparticles to obtain the modified titanium dioxide nanoparticles.

5. The fluorosilicon-modified low surface energy antifouling coating according to claim 1 or 4, characterized in that: The modified titanium dioxide nanoparticles are prepared by mixing the titanium dioxide precursor and water in a mass ratio of 1:100-120, adding polydopamine nanoparticles equal in mass to the titanium dioxide precursor, adjusting the pH to 1-2 with 1 mol / L hydrochloric acid solution, stirring and refluxing at 80-85°C and 200-300 r / min for 10-12 h, continuing to stir and react at 50-55°C for 4-5 h, adjusting the pH to 7-8 with 1 mol / L sodium hydroxide solution, centrifugal separation and washing 3-5 times, and drying at 50-60°C and 50-100 Pa for 10-12 h.

6. The fluorosilicon-modified low surface energy antifouling coating according to claim 4, characterized in that: The titanium dioxide precursor is prepared by mixing anhydrous ethanol, water and isopropyl alcohol in a mass ratio of 2:1:10-12, uniformly adding tetrabutyl titanate with a mass of 0.2-0.3 times that of the anhydrous ethanol at a constant speed within 3-5 min under stirring at room temperature and 200-300 r / min, continuing to stir and react for 30-40 min, centrifugal separation and washing 3-5 times, and drying at 50-60°C and 50-100 Pa for 10-12 h.

7. The fluorosilicon-modified low surface energy antifouling coating according to claim 4, characterized in that: The polydopamine nanoparticles are prepared by mixing dopamine hydrochloride and water in a mass ratio of 1:300-400, adding 1 mol / L sodium hydroxide solution with a mass of 0.3-0.5 times that of the dopamine hydrochloride dropwise, stirring and reacting at 50-60°C and 200-300 r / min for 4-5 h, centrifugal separation and washing 3-5 times, and drying at 50-60°C and 50-100 Pa for 10-12 h.

8. A process for the preparation of the fluorosilicon-modified low surface energy antifouling coating according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: Under nitrogen atmosphere, mix uniform the specified amount of butyl acrylate, methacrylic acid dodecafluoroheptyl ester, end vinyl polydimethyl silane, 2-hydroxy-4-acryloyloxy benzophenone, methyl isobutyl ketone, under the condition of 70-80℃, 200-300r / min stirring, add azobis isobutyronitrile at a uniform speed within 80-100min, keep the temperature unchanged after the addition is completed, continue stirring for 3-4h, then add sodium hydroxide, modified titanium dioxide nanoparticles, 3-aminopropyl triethoxysilane and continue stirring for 3-5min, to obtain fluorine-silicon modified low surface energy antifouling coating.

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