A kind of auxiliary agent for antifouling and waterproof coating and preparation method thereof

Abstract

The present invention relates to the technical field of functional materials, and in particular to an auxiliary agent for antifouling and waterproofing of coatings and a preparation method thereof, wherein the raw materials for preparation include POSS silicon and fluorinated silane, wherein the molar ratio of fluorosilane groups to silanol groups in POSS silicon in fluorinated silane is in the range of 1 to 1.2. The auxiliary agent of the present invention adopts POSS silicon as an auxiliary agent body, and its unique network structure can, on the basis of the original performance of the coating, improve the strength of the coating. After being modified by fluorinated silane, lower surface energy can be obtained, so that the adhesion between dust and the coating is reduced, there is good hydrophobic and oleophobic effect, self-cleaning is achieved, and after adding coating, oil stains can be effectively prevented from adhering to the coating surface, the purpose of putting graffiti is achieved, and the coating surface is kept clean, and the coating can be effectively improved in service life. The particle size of the auxiliary agent of the present invention is relatively small, being 1 3 nm, and the color of the original coating will not be affected after adding the coating.

Description

Technical Field

[0001] The invention relates to the technical field of functional materials, and in particular to an additive for antifouling and waterproofing of coatings and a preparation method thereof. Background Art

[0002] Anti-graffiti paint is a measure commonly used at home and abroad to effectively prevent the pasting of small advertisements. It is generally applied to locations below 2m.

[0003] In recent years, the concept of the entire life cycle has gradually been introduced by more designers in various industries, including in municipal construction. This puts forward requirements for anti-graffiti and anti-sticking coatings to be long-lasting, easy to apply, and suitable for different substrates such as common metals and cement.

[0004] The raw materials commonly used for anti-graffiti coatings are:

[0005] (1) Low surface energy resins: polyurethane, fluororesin, fluorosilicone resin, water-based polyurethane and water-based cross-linked fluororesin, etc. However, the above resins have electrostatic adsorption, and the surface will adsorb dust and small molecular organic matter, thus greatly reducing the service life.

[0006] (2) Silicone additives: Additives can reduce the surface tension of the coating, making the surface smooth and giving the coating anti-graffiti properties. However, the anti-graffiti properties are limited.

[0007] (3) Introduction of nanotechnology: Ultra-dispersion technology is used to maximize the non-agglomeration state of individual particles, and then low surface energy substances are introduced. Due to the effects of intermolecular van der Waals forces and Coulomb forces, low surface energy substance molecules can spread on the surface of nanoparticles to form a highly ordered monomolecular film. Due to the thermal motion of the molecules, low free energy groups in the molecules can migrate toward the surface and be enriched and arranged in a directional and orderly manner, thus forming a surface composed of low free energy groups. However, due to the loose structure of nanoparticles, the surface structure is easily damaged by external forces, and the service life is limited.

[0008] In the above methods, the anti-graffiti material has a limited service life due to various reasons. Therefore, it is urgent to develop an additive that is easy to add, has good anti-fouling and waterproof effects, and can extend the service life of the coating. Summary of the invention

[0009] One of the purposes of the present invention is to provide an antifouling and waterproof additive for coatings, which is used to be added to anti-graffiti coatings and has hydrophobic and oleophobic properties, can effectively prevent oil stains from adhering to the coating surface, effectively prolong the service life of the coating, and keep the coating surface clean.

[0010] The second object of the present invention is to provide a method for preparing an additive for antifouling and waterproofing of coatings, which has a simple preparation process and is easy to adjust.

[0011] The scheme adopted by the present invention to achieve one of the purposes is: an additive for antifouling and waterproof coating, the preparation raw materials of which include POSS silicon and fluorine-containing silane, wherein the molar ratio of fluorosilyl in fluorine-containing silane to silanol in POSS silicon is in the range of 1 to 1.2.

[0012] In the present invention, under the catalytic action of base, methyl orthosilicate or ethyl orthosilicate is subjected to hydrolysis condensation reaction to synthesize POSS silicon, and the reaction formula is as follows:

[0013]

[0014] POSS silicon structure diagram:

[0015]

[0016] After the POSS silicon is completely generated, it is directly modified with fluorosilane, and all the silanol groups on the POSS silicon react with the fluorosilane. After the reaction is completed, an antifouling and waterproofing additive is obtained.

[0017] The carbon chain structure of fluorosilane makes the additive have good compatibility and can be added to various coatings for use. POSS silicon has a porous structure. After being added to the coating, the resin in the coating system can penetrate through the POSS silicon structure, effectively improving the structural strength of the coating.

[0018] Preferably, the molar ratio of the fluorosilyl group in the fluorine-containing silane to the silanol group in the POSS silicon is greater than 1 and less than or equal to 1.2.

[0019] When the amount of fluorinated silane added is controlled to be slightly excessive, that is, the molar ratio of the fluorosilane group in the fluorinated silane to the silanol group in the POSS silicon is greater than 1 and less than or equal to 1.2, a small amount of oxyalkyl groups still fail to fully participate in the reaction after the reaction is completed. When the coating is subsequently added, the compatibility between the additive and the coating can be further increased. However, the excess should not be too much, otherwise it will have a negative effect: mainly because the unreacted silanol groups are hydrophilic groups, which will absorb dust, grease, etc., reducing the self-cleaning effect of the coating.

[0020] Preferably, the POSS silicon is obtained by reacting methyl orthosilicate or ethyl orthosilicate under alkaline conditions at 30-40° C. for 36-48 hours.

[0021] Preferably, the fluorine-containing silane includes one or more of perfluorodecyltrimethoxysilane, perfluorodecyltriethoxysilane, perfluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, and perfluorooctylsulfonylaminopropyltriethoxysilane.

[0022] The solution adopted by the present invention to achieve the second purpose is: a method for preparing an additive for antifouling and waterproof coatings, comprising the following steps:

[0023] (1) Add methyl orthosilicate or ethyl orthosilicate to the dispersion medium, then adjust the pH of the system to alkaline, and react at 30-40° C. for 36-48 hours;

[0024] (2) adding fluorine-containing silane to the reaction system of step (1), mixing evenly and reacting at a certain temperature for a certain time;

[0025] (3) The mixed system obtained in step (2) is washed with water and dried to obtain the additive for antifouling and waterproofing of coatings.

[0026] In the preparation method of the present invention, POSS silicon is first prepared, and then modified by fluorosilane. Compared with the one-pot method (i.e., reacting after feeding silicate, alkaline catalyst and fluorinated silane at the same time), it has the following advantages: POSS silicon is first prepared, and it is used as the main body of the auxiliary agent, mainly by utilizing its porous structure, and the strength of the coating can be improved on the basis of the original performance of the coating. The powder of the particle size of POSS silicon 1-3nm is colorless and transparent when added to the coating, and the coating appearance will not be affected. The long-chain fluorosilane selected can make the fluorine group be on the coating surface as much as possible, so that the coating has a self-cleaning effect.

[0027] Preferably, in step (1), the alkaline catalyst used is sodium hydroxide or aqueous ammonia, and the pH of the system is adjusted to 7-9.

[0028] Preferably, in step (1), the dispersion medium is a mixture of water and at least one of methanol, ethanol and n-butanol.

[0029] Furthermore, the dispersion medium is a mixture of water and methanol or ethanol, and the volume ratio of water to methanol or ethanol is 1:8-10.

[0030] Preferably, in step (2), the fluorine-containing silane includes one or more of perfluorodecyltrimethoxysilane, perfluorodecyltriethoxysilane, perfluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, and perfluorooctylsulfonylaminopropyltriethoxysilane.

[0031] Preferably, in step (2), fluorine-containing silane is added to the reaction system of step (1), mixed evenly at 500-800 rpm at room temperature, then heated to 55-70° C., and stirred continuously for reaction for 20-24 hours.

[0032] Preferably, in step (3), the particle size of the additive for antifouling and waterproofing of coatings is 1 to 3 nm.

[0033] Poss silicon is an octa-silicon structure. The particle size of the additive for antifouling and waterproof coatings prepared with POSS silicon as raw material is 1 to 3 nm, which gives it a larger specific surface area. After being added to the coating, it has a better antifouling and waterproof effect.

[0034] The present invention has the following advantages and beneficial effects:

[0035] (1) The auxiliary agent of the present invention adopts POSS silicon as the auxiliary agent main body, and its unique network structure can improve the strength of the coating on the basis of the original performance of the coating. After modification by fluorine-containing silane, a lower surface energy can be obtained, so that the adhesion between dust and the coating is reduced, and it has good hydrophobic and oleophobic effects, and realizes self-cleaning.

[0036] (2) The additive of the present invention has good hydrophobic and oleophobic properties. After being added to the paint, it can effectively prevent oil stains from adhering to the paint surface, thereby achieving the purpose of preventing graffiti, keeping the coating surface clean, and at the same time effectively prolonging the service life of the coating.

[0037] (3) The particle size of the additive of the present invention is relatively small, 1-3 nm, and will not affect the color of the original coating after being added to the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The test diagrams of the water contact angle (left) and oil contact angle (right) of the auxiliary agent coating prepared in Example 1 after drying;

[0039] Figure 2 The test diagrams of water contact angle (left) and oil contact angle (right) of the auxiliary agent coating prepared in Example 2 after drying;

[0040] Figure 3 The test diagrams of the water contact angle (left) and oil contact angle (right) of the auxiliary agent coating prepared in Example 3 after drying;

[0041] Figure 4 The test diagrams of the water contact angle (left) and oil contact angle (right) of the auxiliary agent coating prepared in Comparative Example 1 after drying;

[0042] Figure 5 The test diagrams of the water contact angle (left) and oil contact angle (right) of the auxiliary agent coating prepared in Comparative Example 3 after drying;

[0043] Figure 6 The water contact angle (left) and oil contact angle (right) test diagrams of the paint coating after drying before adding additives;

[0044] Figure 7 The test diagrams are of the water contact angle (left) and oil contact angle (right) of the paint coating after drying after adding the additive prepared in Example 2. DETAILED DESCRIPTION

[0045] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples.

[0046] The raw materials, reagents and materials used in the following specific embodiments are all commercially available products unless otherwise specified.

[0047] The invention provides an antifouling and waterproof auxiliary agent, wherein the raw materials for preparing the auxiliary agent include POSS silicon and fluorine-containing silane, wherein the molar ratio of the fluorine silane group in the fluorine-containing silane to the silanol group in the POSS silicon is 1 to 1.2, and the auxiliary agent is prepared in a dispersion medium, wherein the auxiliary agent includes 40% to 50% of POSS silicon, 5% to 10% of fluorine-containing silane, and the balance is the dispersion medium according to mass percentage. The dispersion medium is one or two of water, methanol, ethanol, and n-butanol, and more preferably a mixed solvent of water and methanol or ethanol.

[0048] In the antifouling and waterproofing auxiliary agent of the present invention, POSS silicon is used as the auxiliary agent main body; fluorinated siloxane is used to modify the silanol group, including but not limited to perfluorodecyl trimethoxysilane, perfluorodecyl triethoxysilane, perfluorooctyl trimethoxysilane, tridecafluorooctyl triethoxysilane, and perfluorooctyl sulfonyl aminopropyl triethoxysilane.

[0049] The preparation method is as follows:

[0050] 1) adding methyl orthosilicate / ethyl orthosilicate to methanol / ethanol mixed with water, and then adding sodium hydroxide dispersion to make the pH between 7 and 9, dispersing at 100 to 300 rpm, the reaction temperature is 30 to 40° C., and the reaction time is 36 to 48 hours;

[0051] 2) adding fluorinated silane to the mixed solution obtained in step 1), mixing it uniformly at 500-800 rpm at room temperature, then heating it to 55-70° C. and reacting it for 20-24 hours;

[0052] 3) The mixed solution obtained in step 2) is washed with water for multiple times, and then subjected to rotary evaporation to obtain a powder, which is the antifouling and waterproofing auxiliary agent.

[0053] The additive prepared by the present invention is added into the coating (including but not limited to conventional silicon fluorocarbon coating, polyurethane coating, epoxy coating, silicone protective coating, conventional interior and exterior wall coating) in an amount of 2% to 10% of the weight of the coating. After the additive is added into the coating system, it can effectively prevent oil stains from adhering to the coating surface, so that the coating effectively increases its service life and keeps the coating surface clean.

[0054] Example 1

[0055] A method for preparing an antifouling and waterproof additive for coatings comprises the following steps:

[0056] 1) Add 50 g of ethyl orthosilicate to 40 g of a mixed solution of water and ethanol at a water-to-alcohol ratio of 1:9, start stirring, adjust the speed to 300 rpm, then dropwise add 1 mol / L sodium hydroxide solution, adjust the pH to 9, adjust the reaction temperature to 40°C, and react for 36 hours;

[0057] 2) Add 11.9 g of perfluorooctanesulfonylaminopropyltriethoxysilane to the mixed solution obtained in step 1), mix at 500-800 rpm for 30 min at room temperature to make it uniform, then heat the water bath to 70° C. and react for 24 h;

[0058] 3) The mixed solution obtained in step 2) was washed with water for three times, and then rotary evaporated to obtain 25.9 g of powder, which is an antifouling and waterproofing agent.

[0059] Figure 1 This is a contact angle test diagram of the auxiliary agent coating prepared in Example 1 after drying, where a is the water contact angle and b is the oil contact angle. It can be seen from the figure that the auxiliary agent coating has excellent super-hydrophobic and super-oleophobic properties.

[0060] Example 2

[0061] A method for preparing an antifouling and waterproof additive for coatings comprises the following steps:

[0062] 1) Add 50 g of ethyl orthosilicate to 40 g of a mixture of water and ethanol at a water-to-alcohol ratio of 1:9, start stirring, adjust the speed to 300 rpm, then dropwise add 1 mol / L sodium hydroxide solution, adjust the pH to 9, adjust the reaction temperature to 40°C, and react for 48 hours;

[0063] 2) Add 13.1 g of perfluorooctanesulfonylaminopropyltriethoxysilane to the mixed solution obtained in step 1), mix at 500-800 rpm for 30 min at room temperature to make it uniform, then heat the water bath to 70° C. and react for 24 h;

[0064] 3) The mixed solution obtained in step 2) was washed with water for three times, and then rotary evaporated to obtain 27.1 g of powder, which is an antifouling and waterproofing auxiliary agent.

[0065] Figure 2 This is a contact angle test diagram of the auxiliary coating prepared in Example 2 after drying, where a is the water contact angle and b is the oil contact angle. It can be seen from the figure that the auxiliary coating has excellent super-hydrophobic and super-oleophobic properties. Compared with Example 1, after further adjusting the raw material ratio, its hydrophobicity and oleophobicity are improved to a certain extent.

[0066] Example 3

[0067] A method for preparing an antifouling and waterproof additive for coatings comprises the following steps:

[0068] 1) Add 50 g of ethyl orthosilicate to 40 g of a mixture of water and ethanol at a water-to-alcohol ratio of 1:9, start stirring, adjust the speed to 200 rpm, then dropwise add 1 mol / L sodium hydroxide solution, adjust the pH to 9, adjust the reaction temperature to 40°C, and react for 48 hours;

[0069] 2) Add 14.3 g of perfluorooctanesulfonylaminopropyltriethoxysilane to the mixed solution obtained in step 1), mix at 500-800 rpm for 30 min at room temperature to make it uniform, then heat the water bath to 70° C. and react for 24 h;

[0070] 3) The mixed solution obtained in step 2) was washed with water for three times, and then rotary evaporated to obtain 29.3 g of powder, which is an antifouling and waterproofing agent.

[0071] Figure 3 This is a contact angle test diagram of the auxiliary agent coating prepared in Example 3 after drying, where a is the water contact angle and b is the oil contact angle. It can be seen from the figure that the auxiliary agent coating has excellent super-hydrophobic and super-oleophobic properties.

[0072] Example 4

[0073] A method for preparing an antifouling and waterproof additive for coatings comprises the following steps:

[0074] 1) Add 50 g of methyl orthosilicate to a 40 g solution of water and n-butanol in a water-to-alcohol ratio of 1:8, start stirring, adjust the speed to 400 rpm, then dropwise add 1 mol / L sodium hydroxide solution, adjust the pH to 8, adjust the reaction temperature to 40°C, and react for 36 hours;

[0075] 2) adding 18.7 g of perfluorodecyltrimethoxysilane to the mixed solution obtained in step 1), mixing at 500-800 rpm for 30 min at room temperature to make it uniform, then heating the mixture in a water bath to 55° C. and reacting for 24 h;

[0076] 3) The mixed solution obtained in step 2) was washed with water for three times, and then rotary evaporated to obtain 38.4 g of powder, which is an antifouling and waterproofing agent.

[0077] Example 5

[0078] A method for preparing an antifouling and waterproof additive for coatings comprises the following steps:

[0079] 1) Add 50 g of methyl orthosilicate to a mixture of 40 g of water and methanol at a water-to-alcohol ratio of 1:10, start stirring, adjust the speed to 400 rpm, then dropwise add 1 mol / L sodium hydroxide solution, adjust the pH to 8, adjust the reaction temperature to 35° C., and react for 42 hours;

[0080] 2) adding 18.7 g of perfluorodecyltrimethoxysilane to the mixed solution obtained in step 1), mixing at 500-800 rpm for 30 min at room temperature to make it uniform, then heating the mixture in a water bath to 60° C. and reacting for 20 h;

[0081] 3) The mixed solution obtained in step 2) was washed with water for three times, and then rotary evaporated to obtain 38.4 g of powder, which is an antifouling and waterproofing agent.

[0082] Example 6

[0083] A method for preparing an antifouling and waterproof additive for coatings comprises the following steps:

[0084] 1) Add 50 g of methyl orthosilicate to a mixture of 40 g of water and ethanol in a water-to-alcohol ratio of 1:10, start stirring, adjust the speed to 400 rpm, then dropwise add 1 mol / L sodium hydroxide solution, adjust the pH to 8, adjust the reaction temperature to 30, and react for 48 hours;

[0085] 2) adding 18.7 g of perfluorodecyltrimethoxysilane to the mixed solution obtained in step 1), mixing at 500-800 rpm for 30 min at room temperature to make it uniform, then heating the mixture in a water bath to 65° C. and reacting for 22 h;

[0086] 3) The mixed solution obtained in step 2) was washed with water for three times, and then rotary evaporated to obtain 38.4 g of powder, which is an antifouling and waterproofing agent.

[0087] Comparative Example 1:

[0088] The difference between Comparative Example 1 and Example 2 is that only 8.3 g of perfluorooctanesulfonylaminopropyltriethoxysilane is added in Comparative Example 1; other operations are the same.

[0089] Figure 4 This is a contact angle test diagram of the auxiliary agent coating prepared in Comparative Example 1 after drying, where a is the water contact angle and b is the oil contact angle. It can be seen from the figure that the auxiliary agent coating has hydrophobic and oleophobic properties, but has not reached the super-amphiphobic level, so reducing the amount of modifier used will affect the hydrophobic and oleophobic properties of the auxiliary agent.

[0090] Comparative Example 2

[0091] The difference between Comparative Example 2 and Example 2 is that in Comparative Example 2, orthosilicate, sodium hydroxide solution and perfluorooctanesulfonylaminopropyltriethoxysilane are uniformly mixed and reacted at 70° C. After the reaction is complete, an auxiliary agent product is obtained.

[0092] Comparative Example 3

[0093] The only difference between Comparative Example 3 and Example 2 is that in Comparative Example 3, the molar ratio of the fluorosilyl group in the fluorine-containing silane to the silanol group in the POSS silicon is 1.5, and the other operations are the same.

[0094] Figure 5 This is a contact angle test diagram of the auxiliary agent coating prepared in Comparative Example 3 after drying, where a is the water contact angle and b is the oil contact angle. It can be seen from the figure that the auxiliary agent coating has hydrophobic and oleophobic properties, but has not reached the super-amphiphobic level, so excessive use of the modifier will affect the hydrophobic and oleophobic properties of the auxiliary agent.

[0095] Application testing:

[0096] 1. Take 5g of the additives prepared in Examples 1-6 and Comparative Examples 1-3, disperse them in 95g of ethanol and spray them on the rust-removed carbon steel plate, with a dry film thickness of 1-5μm. After the samples were placed at room temperature for 7 days, performance tests were conducted, and the test results are shown in Table 1.

[0097] Table 1

[0098]

[0099] As shown in the data in Table 1: When the group amount ratio between POSS silicon and fluorinated silane is 1:1~1.2, the modified auxiliary powder has super hydrophobicity and super oleophobicity, and when it is lower than or higher than this ratio, hydrophobicity and oleophobicity are significantly reduced. The types of other fluorosilane modifiers in the present invention and the types of environmental solvents are used, and the hydrophobicity and oleophobicity of the modified auxiliary are not affected. In Comparative Example 2, when the modified auxiliary is made by one-pot method, silicate will self-polymerize, react with fluorosilane modifier, fluorosilane will also self-polymerize, and finally obtain a resin-like gel product, and a powdered auxiliary agent cannot be obtained, so that subsequent addition to the coating cannot be performed.

[0100] 2. Take 5g of the additives prepared in Examples 1-6 and Comparative Examples 1-3, add them to 100g of the same polyurethane protective coating, mix and prepare samples, spray them on the carbon steel plate after rust removal, and the dry film thickness is 100-150μm. The samples were placed at room temperature for 7 days before performance testing. The wear resistance was tested according to GB / T 1768-2006, 1kg, 1000r; the adhesion was tested according to GB / T1720-1979; the water resistance test was soaked in water for 24 hours; the chemical reagent resistance test was soaked in acid, alkali and salt reagents (concentration 3%) at 25℃ for 24h; the oil resistance test was soaked in transformer oil at 100℃ for 24h; the UV aging resistance was tested according to GB / T 23987-2009, 1000h; the salt spray resistance was tested according to GB / T 1771-2007, 1000h.

[0101] The test results are shown in Table 2:

[0102] Table 2

[0103]

[0104]

[0105] As shown in the data of Table 2: when the group amount ratio between POSS silicon and fluorinated silane is 1:1-1.2, the modified auxiliary powder is added to the coating, and the coating obtained after spraying and drying has good hydrophobicity and oleophobicity. When it is lower than or higher than this ratio, hydrophobicity and oleophobicity obviously decrease, and the oil contact angle is less than 90 ° (showing as lipophilicity). By the kind of other fluorosilane modifiers in the present invention, and the kind of environmental solvent, the hydrophobicity and oleophobicity of the coating will not be affected. In Comparative Example 2, it is impossible to use the modified auxiliary agent made by one pot method.

[0106] Figure 6 This is a contact angle test diagram of the paint coating before adding additives, where a is the water contact angle and b is the oil contact angle. It can be seen from the figure that the paint coating has hydrophilic and lipophilic properties.

[0107] Figure 7 This is a contact angle test diagram of the paint coating after adding the additive prepared in Example 2, where a is the water contact angle and b is the oil contact angle. It can be seen from the figure that the paint coating after adding the additive has hydrophobic and oleophobic properties.

[0108] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. An additive for antifouling and waterproofing of coatings, Features: The preparation raw materials include POSS silicon and fluorine-containing silane, wherein the molar ratio of the fluorine silane group in the fluorine-containing silane to the silanol group in the POSS silicon is greater than 1 and less than or equal to 1.2, the POSS silicon is obtained by reacting methyl orthosilicate or ethyl orthosilicate under alkaline conditions, 30-40°C, and 300-500rpm / min stirring conditions for 36-48h, and the fluorine-containing silane includes one or more of perfluorodecyltrimethoxysilane, perfluorodecyltriethoxysilane, perfluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, and perfluorooctylsulfonylaminopropyltriethoxysilane.

2. A method for preparing an additive for antifouling and waterproofing of coatings according to claim 1, It is characterized in that The following steps are involved: (1) Add methyl orthosilicate or ethyl orthosilicate to the dispersion medium, then add an alkaline catalyst and adjust the pH of the system to alkaline, and react at 30-40°C and 300-500 rpm / min for 36-48 hours; (2) adding fluorinated silane to the reaction system of step (1), mixing evenly and reacting at a certain temperature for a certain time; (3) The mixed system obtained in step (2) is washed with water and dried to obtain the additive for antifouling and waterproofing of coatings.

3. The method for preparing an additive for antifouling and waterproofing of coatings according to claim 2, Features: In the step (1), the alkaline catalyst used is sodium hydroxide or ammonia water, and the pH of the system is adjusted to 7-9.

4. The method for preparing an additive for antifouling and waterproofing of coatings according to claim 2, Features: In the step (1), the dispersion medium is a mixture of water and at least one of methanol, ethanol and n-butanol, and the volume ratio of water to alcohol is 1:8-10.

5. The method for preparing an additive for antifouling and waterproofing of coatings according to claim 2, Features: In the step (2), the fluorine-containing silane includes one or more of perfluorodecyltrimethoxysilane, perfluorodecyltriethoxysilane, perfluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, and perfluorooctylsulfonylaminopropyltriethoxysilane.

6. The method for preparing an additive for antifouling and waterproofing of coatings according to claim 2, Features: In the step (2), fluorine-containing silane is added to the reaction system of step (1), mixed evenly at 500-800 rpm and room temperature, then heated to 55-70° C., and stirred continuously for reaction for 20-24 hours.

7. The method for preparing an additive for antifouling and waterproofing of coatings according to claim 2, Features: In the step (3), the particle size of the additive for antifouling and waterproofing of coating is 1-3 nm.

Images