A composite aspartic acid ester resin, aspartic acid polyurea coating composition and its application on wind power blades

Abstract

The application provides a composite aspartic acid ester resin, an aspartic acid polyurea coating composition and application thereof to a wind power blade, and relates to the technical field of aspartic acid polyurea. The composite aspartic acid ester resin is composed of aspartic acid ester resin and aspartic acid ester modified graphene oxide; the aspartic acid ester modified graphene oxide is double-end aspartic acid ester polysiloxane modified graphene oxide; and the double-end aspartic acid ester polysiloxane is the product of Michael addition reaction of double-end amino polysiloxane and maleate. The aspartic acid polyurea coating composition of the application adopts the composite aspartic acid ester resin, can exert the characteristics of graphene oxide, and improves the corrosion resistance, weather resistance, high and low temperature resistance and other performances of the aspartic acid polyurea coating.

Description

A composite aspartic ester resin and aspartic polyurea coating composition and its application on wind turbine blades. Technical Field

[0001] This invention belongs to the field of aspartic polyurea technology, and relates to a composite aspartic ester resin, an aspartic polyurea coating composition, and its application on wind turbine blades. Background Technology

[0002] Wind power is a clean energy source. Wind turbines are typically located on mountains or at sea, where winds are strong and sunlight is abundant. Furthermore, if located at sea or near the coast, they must withstand high temperatures, high humidity, and high salinity. Therefore, wind turbine blades require better protection. Currently, the main method of protecting wind turbine blades is by coating their surface with protective coatings, primarily polyurethane, polyurea, and silicone-fluoropolymer coatings. Polyurethane coatings have good adhesion but poor weather resistance; silicone-fluoropolymer coatings have good weather resistance and hydrophobicity but poor adhesion; polyurea coatings have both good adhesion and weather resistance, and also offer good impact resistance.

[0003] Graphene is a layered nanomaterial that, when added to coatings, can improve their protective and anti-corrosion properties. Chinese patent CN107987274A discloses an aspartic polyurea anti-corrosion coating. This coating grafts modified graphene oxide onto polyaspartic ester resin by undergoing a Michael addition reaction between aminosilane-modified graphene oxide, a diamine, and maleic ester. This improves the dispersion properties of graphene oxide in the coating, enhances its hardness, abrasion resistance, and weather resistance, and improves the antistatic and anti-corrosion properties of the coating film.

[0004] The applicant believes that the above method can be further improved to further enhance the corrosion resistance of aspartic polyurea coatings. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a composite aspartic acid ester resin, aspartic polyurea coating composition, and its application on wind turbine blades.

[0006] The technical solution of the present invention is as follows:

[0007] A composite aspartic acid ester resin is composed of aspartic acid ester resin and aspartic acid ester modified graphene oxide.

[0008] The aspartic acid ester modified graphene oxide is a double-terminated aspartic acid ester polysiloxane modified graphene oxide.

[0009] The di-terminated aspartic acid ester polysiloxane is the product of a Michael addition reaction between di-terminated amino polysiloxane and maleate.

[0010] Preferably, the weight ratio of the aspartic acid ester resin to the aspartic acid ester modified graphene oxide is 100:1-20.

[0011] Preferably, the terminal group of the diamino-terminated polysiloxane is a primary amino group, and the side chain is chemically bonded with alkoxysilyl groups.

[0012] More preferably, the number of alkoxysilyl groups accounts for not less than 8% and not more than 30% of the degree of polymerization of the diamino-terminated polysiloxane.

[0013] More preferably, the structure of the double-terminated amino polysiloxane is shown in formula (1) below.

[0014] NH2R 1 SiMe2O(SiOMe2) x (SiOMeR 2 ) y (SiOMeR 3 ) z SiMe2R 1 NH2(1)

[0015] Among them, R 1 Selected from C2-C8 alkylene, substituted C3-C8 alkylene, or C6-C12 cycloalkylene, where Me is methyl and R is... 2 -(CH2) n Si(OR 4 )3, R 3 Selected from C1-C18 alkyl, F-substituted C3-C10 alkyl or aryl groups, R 4 Selected from C1-C4 alkyl groups, x≥10, y≥3, z≥0, 0.08≤y / (x+y+z)≤0.3, n=2-6.

[0016] Preferably, the structure of the maleate ester is shown in formula (2).

[0017] R 5 OOC = COOR 6 (2)

[0018] Among them, R 5 and R 6 The individual is selected from C1-C4 alkyl groups.

[0019] An aspartic polyurea coating composition, comprising component A and component B;

[0020] Component A, by weight, comprises: 100 parts of the composite aspartic acid ester resin described in any of the above embodiments, 0-80 parts of pigments and fillers, and 1-5 parts of additives;

[0021] Component B is an isocyanate curing agent.

[0022] Preferably, the isocyanate curing agent is a polyester-modified isocyanate curing agent, and the NCO content in the polyester-modified isocyanate curing agent is 2-6 wt%.

[0023] More preferably, the polyester-modified isocyanate curing agent is prepared by reacting a polyester polyol with a diisocyanate compound and then adding a chain extender to extend the chain.

[0024] The application of the aspartic polyurea coating composition described in any of the above embodiments as a protective coating on wind turbine blades.

[0025] The beneficial effects of this invention are:

[0026] (1) To improve the protective effect of aspartic polyurea coatings, this invention adds graphene oxide (GO) to aspartic polyurea. The layered structure of GO can significantly improve the corrosion resistance and weather resistance of aspartic polyurea. This invention uses a polysiloxane with a double-terminated aspartic ester structure to modify GO, which can improve the dispersibility of GO in the aspartic polyurea coating composition. Moreover, the terminal aspartic ester structure can also participate in the curing of the aspartic polyurea coating composition, allowing GO to participate in the cross-linking and curing network structure of the aspartic polyurea coating, further improving the dispersion stability of GO in aspartic polyurea and the corrosion resistance of aspartic polyurea.

[0027] (2) GO is modified with polysiloxanes with double-terminated aspartic ester structures. The polysiloxane structures on the surface of the aspartic polyurea coating can migrate and precipitate on the surface of the coating, improving the hydrophobicity, weather resistance, and other properties of the coating, and further enhancing the corrosion resistance and weather resistance of the aspartic polyurea coating. The polysiloxane structures inside the coating participate in the cross-linking structure of the aspartic polyurea, which can play a role in toughening the aspartic polyurea coating and improving its resistance to high and low temperatures.

[0028] (3) Polysiloxanes with side-chain bonded alkoxysilyl groups are used. The alkoxysilyl groups can react with GO and chemically bond the di-terminated aspartic acid ester polysiloxane to GO, thus achieving good modification of GO. Detailed Implementation

[0029] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0030] To further improve the protective performance of aspartic polyurea coatings, this invention proposes a composite aspartic ester resin, which is composed of aspartic ester resin and aspartic ester modified graphene oxide.

[0031] Aspartic acid ester modified graphene oxide is double-terminated aspartic acid ester polysiloxane modified graphene oxide.

[0032] The di-terminated aspartic ester polysiloxane is the product of the Michael addition reaction between the di-terminated amino polysiloxane and the maleic ester.

[0033] In this invention, aspartic acid ester modified graphene oxide is added to aspartic acid ester resin. The aspartic acid ester modified graphene oxide is mainly composed of three structural parts: (1) graphene oxide (GO), which can improve the anti-corrosion and other properties of the coating; (2) polysiloxane structure, which has the characteristics of hydrophobicity, high and low temperature resistance, good flexibility, and good weather resistance, and can improve the waterproof, anti-corrosion, impact resistance, high and low temperature resistance, and weather resistance of the coating; (3) terminal aspartic acid ester structure (the structure of terminal amino group and maleic acid ester reaction), which can improve the compatibility with aspartic acid ester resin and provide secondary amino groups to participate in the crosslinking of aspartic acid ester resin, thus giving full play to the performance characteristics of polysiloxane structure.

[0034] The preparation method of the above-mentioned double-terminated aspartic acid ester polysiloxane modified graphene oxide can be as follows: disperse graphene oxide (GO) in an organic solvent, add double-terminated aspartic acid ester polysiloxane (the weight of double-terminated aspartic acid ester polysiloxane can be 0.5-10 times the weight of GO), react at a certain temperature, separate the solid after the reaction is complete, wash the solid with an organic solvent and dry it to obtain the graphene oxide.

[0035] In this invention, the aspartic acid ester resin is a Michael addition reaction product of a diamine compound (such as 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane) and a maleic ester (such as diethyl maleate). There are no particular limitations; it can be F420, F520, F421, F220, F330 from Feiyang Junyan Company, or NH1420, NH1520 from Bayer Company.

[0036] In a preferred embodiment of the present invention, the weight ratio of aspartic ester resin to aspartic ester-modified graphene oxide is 100:1-20. For example, the weight ratio of aspartic ester resin to aspartic ester-modified graphene oxide can be any value from 100:1, 100:3, 100:5, 100:6, 100:8, 100:10, 100:12, 100:13, 100:15, 100:16, 100:18, 100:20, etc., without particular limitation. Preferably, the weight ratio of aspartic ester resin to aspartic ester-modified graphene oxide can be 100:3-20. When the weight ratio of aspartic ester resin to aspartic ester-modified graphene oxide is lower than 100:3 (e.g., 100:1, 100:2, etc.), the improvement in the high and low temperature resistance of the aspartic polyurea coating is less due to the introduction of fewer polysiloxane structures. When the weight ratio is not less than 100:3 (such as 100:4, 100:5, etc.), the high and low temperature resistance of the aspartic polyurea coating is significantly improved.

[0037] In a preferred embodiment of the present invention, the terminal groups of the diamino-terminated polysiloxane are primary amino groups, and the side chains are chemically bonded with alkoxysilyl groups. The primary amino groups of the diamino-terminated polysiloxane can react with maleic esters to form an aspartic ester structure at the terminal group of the polysiloxane, providing secondary amino groups to participate in the crosslinking of the aspartic polyurea coating; the alkoxysilyl groups on the side chains can react with hydroxyl groups on the GO surface, chemically linking the polysiloxane structure and GO together.

[0038] More preferably, the number of alkoxysilyl groups in the degree of polymerization of the diamino-terminated polysiloxane is not less than 8% and not more than 30%. If the number of alkoxysilyl groups is too small or the proportion is too low, the number of active groups is insufficient, resulting in low reactivity with GO and slow reaction efficiency. If the number of active groups is too large or the proportion is too high, the stability of the diamino-terminated polysiloxane will be poor, and some adjacent active groups may even compete with each other, leading to a large number of residual active groups, which affects the stability of aspartic acid ester modified graphene oxide and / or composite aspartic acid ester resin. For example, the proportion of alkoxysilyl groups in the degree of polymerization of the diamino-terminated polysiloxane can be 8%, 10%, 12%, 13%, 15%, 17%, 18%, 20%, 22%, 25%, 27%, 28%, 30%, etc., without particular limitation. More preferably, the proportion of alkoxysilyl groups in the degree of polymerization of the diamino-terminated polysiloxane is not less than 8% and not more than 20%.

[0039] More preferably, the structure of the double-amino-terminated polysiloxane is shown in formula (1) below.

[0040] NH2R 1 SiMe2O(SiOMe2) x (SiOMeR 2 ) y (SiOMeR 3 ) z SiMe2R 1 NH2(1)

[0041] Among them, R 1 Selected from C2-C8 alkylene, substituted C3-C8 alkylene, or C6-C12 cycloalkylene, where Me is methyl and R is... 2 -(CH2) n Si(OR 4 )3, R 3 Selected from C1-C18 alkyl, F-substituted C3-C10 alkyl or aryl groups, R 4 Selected from C1-C4 alkyl groups, x≥10, y≥3, z≥0, 0.08≤y / (x+y+z)≤0.3, n=2-6.

[0042] In the structure of the bi-amino-terminated polysiloxane shown in formula (1) above, y / (x+y+z) is the proportion of the number of alkoxysilyl groups in the degree of polymerization of the bi-amino-terminated polysiloxane, y is the number of alkoxysilyl groups, and x+y+z is the degree of polymerization of the bi-amino-terminated polysiloxane. The preparation method of the bi-amino-terminated polysiloxane shown in formula (1) is well known to those skilled in the art, for example, it can be prepared from the corresponding bi-amino-hydrogen polysiloxane NH2R. 1 SiMe2O(SiOMe2) x (SiOMeH) y (SiOMeR 3 ) z SiMe2R 1 NH2 and alkenylsilane coupling agent CH2=CH(CH2) n-2 Si(OR 4 )3 can be obtained by hydrosilylation reaction, or by the corresponding diamino-terminated alkenyl polysiloxane NH2R 1 SiMe2O(SiOMe2) x (SiOMeR 7 ) y (SiOMeR 3 ) z SiMe2R 1 NH2 and the hydrogen-containing silane coupling agent HSi(OR) 4 )3 is obtained by hydrosilylation reaction, wherein R 7 -(CH2) n-2 CH=CH2. For example, taking diaminovinyl polysiloxane as an example, a method for hydrosilylation reaction of diaminovinyl polysiloxane and hydrogen-containing silane coupling agent is as follows: 1 mol of diaminovinyl polysiloxane as shown in formula (1) and (1-2) y mol of hydrogen-containing silane coupling agent are added to the reaction vessel, the temperature is raised to 80-90℃, Pt catalyst (such as Karstedt catalyst, the amount added is 10-500 ppm according to the amount of Pt) is added, the temperature is maintained at 120-135℃ for 2-5 hours, and then the excess hydrogen-containing silane coupling agent is removed under reduced pressure and the temperature is lowered to obtain diamino polysiloxane.

[0043] The preparation methods of the above-mentioned amino-terminated hydrogen polysiloxanes and amino-terminated alkenyl polysiloxanes are also well known to those skilled in the art. For example, they can be prepared using the amino-terminated agent NH2R. 1 Me2S iOS iMe2R 1The NH2 is obtained by ring-opening reaction with cyclic siloxanes (such as octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, etc.) and / or dialkoxysilanes under acidic or basic catalysts. Taking diamino-terminated vinyl polysiloxane as an example, one preparation method is as follows: 1 mol of amino-terminated agent NH2(CH2)3Me2SiOSiMe2(CH2)3NH2, 20 mol of octamethylcyclotetrasiloxane, (2-4) mol of tetramethyltetravinylcyclotetrasiloxane, and (70-150) g ​​of tetramethylammonium hydroxide alkali gel (1wt%) are added to a reaction vessel. The temperature is raised to 110-120℃ and reacted for 1-3 h. The temperature is raised to 135-140℃ and the catalyst is destroyed under a negative pressure of -0.05 to -0.08 MPa for 0.5-0.8 h. The temperature is then raised to 150-155℃ and the low-boiling substances are removed under -0.099 MPa. The temperature is then lowered to room temperature to obtain diamino-terminated vinyl polysiloxane.

[0044] In a preferred embodiment of the present invention, the structure of the maleate ester is shown in formula (2).

[0045] R 5 OOC = COOR 6 (2)

[0046] Among them, R 5 and R 6 The individual is selected from C1-C4 alkyl groups.

[0047] For example, maleic esters can be dimethyl maleate, dimethyl fumarate, diethyl fumarate, diethyl maleate, dibutyl maleate, etc., such as the commonly used diethyl maleate.

[0048] On the other hand, the present invention proposes an aspartic polyurea coating composition, which is composed of component A and component B;

[0049] Component A, by weight, comprises: 100 parts of the composite aspartic acid ester resin described in any of the above embodiments, 0-80 parts of pigments and fillers, and 1-5 parts of additives;

[0050] Component B is an isocyanate curing agent.

[0051] The aspartic polyurea coating composition of the present invention contains aspartic ester modified graphene oxide in component A, which can synergistically exert the characteristics of GO, polysiloxane segments and aspartic ester structure, thereby improving the hydrophobicity, corrosion resistance, weather resistance, high and low temperature resistance and impact resistance of the aspartic polyurea coating.

[0052] The mixing ratio of component A and component B is well known to those skilled in the art. For example, the amino group in component A and the NCO group in component B are mixed in a molar ratio of 1:1-1.1.

[0053] There are no particular restrictions on the pigments and fillers mentioned above. Pigments can be commonly used inorganic or organic pigments, such as titanium dioxide, phthalocyanine blue, carbon black, phthalocyanine green, chrome green, chrome yellow, molybdenum chrome red, cadmium yellow, cadmium red, cobalt blue, bismuth yellow, titanium nickel yellow, cerium red, etc. The amount of pigment used can be selected according to needs. Fillers can be inorganic or organic fillers, such as wollastonite, talc, kaolin, glass microspheres, heavy calcium carbonate, light calcium carbonate, alumina, polytetrafluoroethylene micropowder, polyethylene micropowder, etc. The amount of filler used can be selected according to needs.

[0054] There are no particular restrictions on the above-mentioned additives, which can be wetting agents, leveling agents, defoamers, UV stabilizers, anti-yellowing agents, dispersants, water absorbents, etc.

[0055] In a preferred embodiment of the present invention, the isocyanate curing agent is a polyester-modified isocyanate curing agent, and the NCO content in the polyester-modified isocyanate curing agent is 2-6 wt%.

[0056] Generally, for aspartic polyurea, an NCO content of 15-20 wt% in the isocyanate curing agent is suitable. However, this invention has found that using a polyester-modified isocyanate curing agent with an NCO content of 2-6 wt% results in better cross-linking and curing effects, leading to better performance of the obtained aspartic polyurea coating, especially in terms of adhesive strength and impact resistance. For example, the NCO content in the polyester-modified isocyanate curing agent can be any value from 2 wt%, 2.3 wt%, 2.5 wt%, 2.7 wt%, 3 wt%, 3.2 wt%, 3.3 wt%, 3.5 wt%, 3.7 wt%, 3.8 wt%, 4 wt%, 4.2 wt%, 4.3 wt%, 4.5 wt%, 4.7 wt%, 4.8 wt%, 5.0 wt%, 5.2 wt%, 5.3 wt%, 5.5 wt%, 5.7 wt%, 5.8 wt%, and 6.0 wt%, without any particular limitation.

[0057] More preferably, the preparation method of the polyester-modified isocyanate curing agent is as follows: reacting a polyester polyol with a diisocyanate compound, followed by adding a chain extender for chain extension, yielding the product. There are no particular limitations on the polyester diol; it can be a conventional polyester polyol, polycarbonate polyol, polycaprolactone polyol, etc. There are also no particular limitations on the diisocyanate compound; it can be IPDI, HMDI, TDI, MDI, etc. The molar ratio of hydroxyl groups in the polyester polyol to NCO in the diisocyanate compound can be 1:1.1-1.4. The chain extender can be ethylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.

[0058] Furthermore, this invention proposes the application of the aspartic polyurea coating composition described in any of the above embodiments as a protective coating on wind turbine blades. The aspartic polyurea coating composition of this invention, when applied to wind turbine blades as a protective coating, can improve the corrosion resistance, weather resistance, and other properties of the wind turbine blades, thereby extending their lifespan.

[0059] The technical solutions of the present invention will be further described and explained below with reference to various embodiments.

[0060] Examples 1-5 Preparation of composite aspartic acid ester resin

[0061] Example 1

[0062] Double-terminated amino polysiloxane NH2(CH2)3SiMe2O(SiOMe2) 78.2 (SiOMeR 2 ) 7.5 SiMe2(CH2)3NH2,R 2 It is -CH2CH2Si(OCH3)3.

[0063] 1 mol of the above-mentioned diamino-terminated polysiloxane and 2.3 mol of diethyl maleate were added to a reaction vessel, heated to 90°C and reacted for 96 h. The pressure was reduced to below -0.099 MPa, and the temperature was raised to 180-185°C to remove unreacted diethyl maleate. The temperature was then lowered to obtain diamino-terminated polysiloxane.

[0064] 10g of Hummers GO was ultrasonically dispersed in 1000g of anhydrous ethanol, and 15g of the above-mentioned di-terminated aspartic acid ester polysiloxane was added. The mixture was stirred at room temperature for 2h, heated to 70℃ and reacted for another 2h. The solid was collected by centrifugation, washed twice with anhydrous ethanol, and dried at 60℃ overnight to obtain aspartic acid ester modified GO.

[0065] The composite aspartic acid ester resin is composed of F420 from Feiyang Junyan Company and the above-mentioned aspartic acid ester modified GO in a weight ratio of 100:1.

[0066] Example 2

[0067] The difference between this embodiment and Embodiment 1 is that the composite aspartic acid ester resin is adjusted to be composed of F420 and aspartic acid ester modified GO in a weight ratio of 100:10.

[0068] Example 3

[0069] The difference between this embodiment and Embodiment 1 is that the composite aspartic acid ester resin is adjusted to be composed of F420 and aspartic acid ester modified GO in a weight ratio of 100:20.

[0070] Example 4

[0071] The difference between this embodiment and Embodiment 2 is that the double-terminated amino polysiloxane is adjusted to NH2(CH2)3SiMe2O(SiOMe2). 40.6 (SiOMeR 2 ) 10.2 SiMe2(CH2)3NH2,R 2 It is -CH2CH2Si(OCH3)3.

[0072] Example 5

[0073] The difference between this embodiment and Embodiment 2 is that the double-terminated amino polysiloxane is adjusted to NH2(CH2)3SiMe2O(SiOMe2). 51.4 (SiOMeR 2 ) 7.8 (SiOMeR f ) 6.2 SiMe2(CH2)3NH2,R 2 -CH2CH2Si(OCH3)3, R f It is perfluorohexylethyl.

[0074] Examples 6-13 Preparation of Aspartic Polyurea Coating Compositions

[0075] Example 6

[0076] The aspartic polyurea coating composition is composed of component A and component B in a molar ratio of amino to NCO groups of 1:1.05;

[0077] The raw material components of component A include: 1000g of the composite aspartic acid ester resin of Example 1, 200g of titanium dioxide, 300g of wollastonite, 6g of organosilicon modified polyether wetting agent Tego 4100, 5g of organosilicon defoamer BYK-077, 6g of UV stabilizer UV-328, and 20g of 3A molecular sieve.

[0078] Component B is an isocyanate curing agent.

[0079] The isocyanate curing agent is a polycarbonate-modified isocyanate curing agent with an NCO content of 16.3 wt%. The polycarbonate-modified isocyanate curing agent is obtained by reacting polycarbonate polyol (average molecular weight 1000) with IPDI.

[0080] Example 7

[0081] The difference between this embodiment and Embodiment 6 is that in Embodiment 6, the composite aspartic acid ester resin of Embodiment 1 is replaced with 1000g of the composite aspartic acid ester resin of Embodiment 2. The remaining steps remain unchanged.

[0082] Example 8

[0083] The difference between this embodiment and Embodiment 6 is that in Embodiment 6, the composite aspartic acid ester resin of Embodiment 1 is replaced with 1000g of the composite aspartic acid ester resin of Embodiment 3. The remaining steps remain unchanged.

[0084] Example 9

[0085] The difference between this embodiment and Embodiment 7 is that in Embodiment 7, the NCO content of the isocyanate curing agent was adjusted to 5.8 wt%. The preparation method of the isocyanate curing agent is as follows: polycarbonate polyol (average molecular weight 1000) and IPDI were added to a reaction vessel at a molar ratio of hydroxyl to NCO groups of 1:1.3. The mixture was stirred at room temperature for 2 hours, then heated to 60°C and stirred for another 2 hours. A certain amount of chain extender 1,4-butanediol was added, and the mixture was stirred at a constant temperature for 2 hours. The mixture was then heated to 95°C and stirred until the NCO group content remained unchanged. After cooling, the isocyanate curing agent was obtained.

[0086] Example 10

[0087] The difference between this embodiment and Embodiment 9 is that in Embodiment 9, the amount of chain extender 1,4-butanediol added was adjusted so that the NCO content of the isocyanate curing agent was 2.3 wt%. The remaining steps remained unchanged.

[0088] Example 11

[0089] The aspartic polyurea coating composition is composed of component A and component B in a molar ratio of amino to NCO groups of 1:1.08;

[0090] The raw material components of component A include: 1000g of the composite aspartic acid ester resin of Example 2, 300g of titanium dioxide, 200g of wollastonite, 10g of phthalocyanine blue, 5g of organosilicon modified polyether wetting agent Tego 4100, 5g of organosilicon defoamer BYK-077, 6g of UV stabilizer UV-328, 5g of dispersant BYK-2009, and 20g of 3A molecular sieve;

[0091] Component B is an isocyanate curing agent.

[0092] The isocyanate curing agent is a polycarbonate-modified isocyanate curing agent with an NCO content of 4.5 wt%. The preparation method of the isocyanate curing agent is as follows: polycarbonate polyol (average molecular weight 1000) and IPDI are added to a reaction vessel at a molar ratio of hydroxyl to NCO groups of 1:1.4. The mixture is stirred at room temperature for 2 hours, then heated to 60°C and reacted for another 2 hours. A certain amount of chain extender 1,6-hexanediol is added, and the mixture is stirred at a constant temperature for 2 hours. The mixture is then heated to 95°C and stirred until the NCO group content remains unchanged. After cooling, the isocyanate curing agent is obtained.

[0093] Example 12

[0094] The difference between this embodiment and Embodiment 11 is that in Embodiment 11, the composite aspartic acid ester resin of Embodiment 2 is replaced with 1000g of the composite aspartic acid ester resin of Embodiment 4. The remaining steps remain unchanged.

[0095] Example 13

[0096] The difference between this embodiment and Embodiment 11 is that in Embodiment 11, the composite aspartic acid ester resin of Embodiment 2 is replaced with 1000g of the composite aspartic acid ester resin of Embodiment 5. The remaining steps remain unchanged.

[0097] Comparative Example 1

[0098] The difference between this comparative example and Example 11 is that in Example 11, the composite aspartic acid ester resin of Example 2 was replaced with 1000g F420. The remaining steps remained unchanged.

[0099] Comparative Example 2

[0100] The difference between this comparative example and Example 11 is that in Example 11, the aspartic acid ester modified GO in the composite aspartic acid ester resin was prepared according to the following method. The remaining steps remained unchanged.

[0101] Preparation method of modified GO:

[0102] 10g of Hummers GO was ultrasonically dispersed in 1000g of anhydrous ethanol, and 15g of 3-aminopropyltrimethoxysilane was added. The mixture was stirred at room temperature for 2 hours, then heated to 70℃ and reacted for another 2 hours. The solid was collected by centrifugation, washed twice with anhydrous ethanol, and dried overnight at 60℃ to obtain amino-modified GO.

[0103] The above-mentioned amino-modified GO (amino content 1 mol) and 1.2 mol diethyl maleate were added to a reaction vessel, heated to 90℃ and reacted for 96 h, then the pressure was reduced to below -0.099 MPa, and the temperature was raised to 180-185℃ to remove unreacted diethyl maleate. The mixture was then cooled to obtain modified GO.

[0104] Performance testing

[0105] After uniformly mixing components A and B of the aspartic polyurea coating compositions of Examples 6-13 and Comparative Examples 1-2, the mixture was coated onto the surface of a clean wind turbine blade with a film thickness of 200 μm and dried at room temperature for 7 days.

[0106] Bond strength: Tested according to GB / T 23446-2009.

[0107] Impact strength: Tested according to ASTM D2794.

[0108] Radiation resistance: Tested according to GB / T 1865-2009, the retention rate of adhesive strength was tested after 2000h of UVB irradiation.

[0109] Salt spray resistance: The time it takes for the membrane to show abnormalities such as blistering, peeling, and edge lifting during a neutral salt spray test, according to the method of GB / T 1771-2007.

[0110] High temperature resistance: The retention rate of bond strength was tested after the sample was placed in an environment of 200℃ for 120 hours.

[0111] High and low temperature cycling stability: 80℃×30min±40×30min constitutes one high and low temperature cycle. Test for 20 cycles and observe for any abnormalities such as peeling, edge lifting, or bubbling.

[0112] Water contact angle: Tested using a water droplet angle tester.

[0113] The results are shown in Table 1 below.

[0114] Table 1

[0115]

[0116]

[0117] As can be seen from the data results in Table 1 above, the aspartic polyurea coating composition of the present invention uses a composite aspartic ester and contains polysiloxane-modified GO, which can significantly improve the protective performance of aspartic polyurea on wind turbine blades.

[0118] As described above, the basic principles, main features, and advantages of the present invention have been shown and described. Those skilled in the art should understand that the present invention is not limited to the above embodiments, which are merely preferred embodiments and should not be construed as limiting the scope of the invention. All equivalent changes and modifications made in accordance with the scope of the patent and the description should still fall within the scope of the present invention. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An aspartic polyurea coating composition, characterized in that, Composed of component A and component B; component A, by weight, comprises: 100 parts of composite aspartic acid ester resin, 0-80 parts of pigments and fillers, and 1-5 parts of additives; the composite aspartic acid ester resin is composed of aspartic acid ester resin and aspartic acid ester modified graphene oxide in a weight ratio of 100:1-20; the aspartic acid ester modified graphene oxide is double-terminated aspartic acid ester polysiloxane modified graphene oxide; the double-terminated aspartic acid ester polysiloxane modified graphene oxide is a product of a Michael addition reaction between double-terminated amino polysiloxane and maleic acid ester; the terminal group of the double-terminated amino polysiloxane is a primary amino group, and the side chain is chemically bonded with alkoxysilyl groups; the structure of the double-terminated amino polysiloxane is shown in formula (1) below, NH2R 1 SiMe2O(SiOMe2) x (SiOMeR 2 ) y (SiOMeR 3 ) z SiMe2R 1 NH2(1) where R 1 Selected from C2-C8 alkylene, substituted C3-C8 alkylene, or C6-C12 cycloalkylene, where Me is methyl and R is... 2 -(CH2) n Si(OR 4 )3, R 3 Selected from C1-C18 alkyl, F-substituted C3-C10 alkyl or aryl groups, R 4 The components are selected from C1-C4 alkyl groups, x≥10, y≥3, z≥0, 0.08≤y / (x+y+z)≤0.3, n=2-6; component B is an isocyanate curing agent.

2. The aspartic polyurea coating composition according to claim 1, characterized in that, The structure of the maleate ester is shown in formula (2), R 5 OOC=COOR 6 (2) Wherein, R 5 and R 6 The individual is selected from C1-C4 alkyl groups.

3. The aspartic polyurea coating composition according to claim 1, characterized in that, The isocyanate curing agent is a polyester-modified isocyanate curing agent, and the NCO content in the polyester-modified isocyanate curing agent is 2-6 wt%.

4. The aspartic polyurea coating composition according to claim 3, characterized in that, The preparation method of the polyester modified isocyanate curing agent is as follows: react polyester polyol with diisocyanate compound and then add chain extender to extend the chain, thus obtaining the product.

5. The application of the aspartic polyurea coating composition according to any one of claims 1-4, characterized in that, It is used as a protective coating on wind turbine blades.

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