Bio-based polyurethane curing agent and amino Mxene anti-corrosion coating and preparation method thereof

Abstract

The invention discloses a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating and a preparation method thereof, belonging to the technical field of anti-corrosion coatings, and comprising a component A and a component B; the component A comprises the following components in parts by weight: 45-55 parts of polyaspartic acid ester resin; 30-40 parts of rutile titanium dioxide; 1-2 parts of high-color carbon black; 0.4-1 part of amino Mxene; 0.5-2 parts of gas-phase nano-silica; 0.1-0.3 parts of ultraviolet absorber; 0.1-0.3 parts of antioxidant; 1-2 parts of adhesion promoter; 1-3 parts of single-end hydroxyl silicone oil; 1-4 parts of composite auxiliary agent; and 4-10 parts of mixed solvent; the component B comprises a bio-based polyurethane curing agent and an isophorone diisocyanate trimer. After the coating of the present invention is completely cured, the pencil hardness can reach 3H, the adhesion is level 0, the artificial accelerated aging can reach 2000h, the salt spray resistance can reach 2100h, and the chemical resistance can reach 240h. It is suitable for use in the atmospheric environment of coastal and offshore areas with high salinity and can achieve a long-term protective effect.

Description

Technical Field

[0001] The invention relates to the technical field of anti-corrosion coatings, and in particular to a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating and a preparation method thereof. Background Art

[0002] Bridges provide great convenience for people's lives and transportation, but they will be damaged as they are used for many years. The corrosion of steel structures is one of the main reasons for bridge damage and even failure, especially the Bay Bridge, which has been in a high humidity and high salt spray corrosion environment for a long time, which has greatly accelerated the corrosion rate of steel structures. Therefore, taking reasonable coating protection is a key measure to extend the service life of bridges.

[0003] The anti-corrosion coating system for steel structure bridges is mainly composed of epoxy zinc-rich primer, epoxy iron oxide intermediate sealing coating and weather-resistant topcoat system. Acrylic aliphatic polyurethane topcoat is composed of aliphatic isocyanate curing agent and hydroxyl-containing acrylic resin, pigment, additives and solvent, and is the most widely used topcoat for bridge steel structures. The result of the ultraviolet accelerated aging test of acrylic aliphatic polyurethane topcoat is about 1000h, and the service life of coating on the outer surface of steel beams is 5 to 8 years. Its service life will be greatly reduced in the atmospheric environment of high-salinity coastal and offshore areas, and it is difficult to achieve long-term protection effect.

[0004] Based on this, the present invention designs a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating and a preparation method thereof to solve the above problems. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating and a preparation method thereof.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] Bio-based polyurethane curing agent and amino Mxene anti-corrosion coating, including component A and component B;

[0008] The component A comprises the following components in parts by weight:

[0009] 45-55 parts of polyaspartic acid resin;

[0010] 30-40 parts of rutile titanium dioxide;

[0011] 1-2 parts of high pigment carbon black;

[0012] Amino Mxene 0.4-1 part; its molecular formula is: (Ti3C2T x)-O3Si(CH2)3NH(CH2)3NH2;

[0013] 0.5-2 parts of fumed nano-silicon dioxide;

[0014] 0.1 to 0.3 parts of ultraviolet absorber;

[0015] 0.1-0.3 parts of antioxidant;

[0016] 1-2 parts of adhesion promoter;

[0017] 1 to 3 parts of mono-terminated hydroxyl silicone oil;

[0018] 1 to 4 parts of composite additives;

[0019] 4 to 10 parts of mixed solvent;

[0020] The component B comprises the following components:

[0021] Bio-based polyurethane curing agent; its structural formula is:

[0022]

[0023] Among them, R-NCO is

[0024] Isophorone diisocyanate trimer.

[0025] Furthermore, the mass ratio of the bio-based polyurethane curing agent to the isophorone diisocyanate trimer is 5:5.

[0026] Furthermore, the mass ratio of the coating component A to component B is 10:6.5-7.5.

[0027] Further, the polyaspartic acid ester resin is one of F520, F524, F5202, and F157, or a combination of two or more thereof;

[0028] The rutile titanium dioxide is one of NR9503 and NR960 or a combination of the two;

[0029] The high-color carbon black is one of MA-100 and MA-11, or a combination of the two;

[0030] The fumed nano-silica is one of Cabot M-5 and TS-720 or a combination of the two;

[0031] The ultraviolet absorber is one of UV-531 and UV-326 or a combination of the two;

[0032] The single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, and is one of X-22-170BX and X-22-176DX or a combination of the two.

[0033] Furthermore, the antioxidant is BASF antioxidant 1010;

[0034] The adhesion promoter is bis(3-trimethoxysilylpropyl)amine;

[0035] The mixed solvent is obtained by uniformly mixing butyl acetate and No. 100 solvent naphtha in a mass ratio of 1:1;

[0036] The isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and has an NCO content of 12±0.3%.

[0037] Furthermore, the composite auxiliary agent includes a defoamer, a dispersant and a leveling agent.

[0038] Further, the defoaming agent is at least one of BYK085 and Defom-6800, or a combination of two thereof;

[0039] The leveling agent is at least one of BYK-333 and BYK-306, or a combination of the two;

[0040] The dispersant is at least one of BYK-111 and BYK163 or a combination of two thereof.

[0041] Furthermore, the preparation method of the bio-based polyurethane curing agent comprises the following steps:

[0042] (a) taking epoxidized soybean oil (ESO), ricinoleic acid (RA) and tetrabutylammonium bromide (TBAB), reacting them in a constant temperature oil bath under stirring conditions to obtain a yellow viscous bio-based polyol (ER) solution for standby use;

[0043] (b) isophorone diisocyanate (IPDI) and dibutyltin dilaurate (DBTDL) are mixed; the bio-based polyol (ER) solution obtained in step (a) and acetyl tributyl citrate (ATBC) are added dropwise to the mixture, and the mixture is reacted in a constant temperature oil bath under mechanical stirring and nitrogen protection conditions, and then the temperature is increased and maintained, and finally the material is discharged into a tinplate can and sealed for storage to obtain a bio-based polyurethane curing agent.

[0044] Furthermore, the preparation method of the amino Mxene comprises the following steps:

[0045] (1) Take titanium carbide (Ti3C2T x )MXene multilayer nanosheets were added to a mixture of ethanol and deionized water;

[0046] (2) adding N-aminoethyl-γ-aminopropyltrimethoxysilane to the above suspension and stirring continuously;

[0047] (3) Next, the mixture obtained in the previous step was filtered through a PVDF membrane and washed several times with deionized water and ethanol to remove unbound N-aminoethyl-γ-aminopropyltrimethoxysilane;

[0048] (4) Finally, the obtained product is baked in vacuum and ground into powder to obtain amino Mxene, which is then stored in vacuum for future use.

[0049] The present invention also provides a method for preparing a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating, comprising the following steps:

[0050] 1. The preparation of component A comprises the following steps:

[0051] 1) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxy silicone oil into a container according to metered amounts, and mechanically stirring to obtain a uniform mixed solution;

[0052] 2) adding rutile titanium dioxide, high-pigment carbon black, amino Mxene, fumed nano-silica, ultraviolet absorber and antioxidant to the mixed solution of step 1), first stirring and dispersing at a low speed, then adding zirconium dioxide beads as grinding media, and grinding with a sand mill;

[0053] 3) filtering the fluid obtained by grinding in step 2), and packaging it into tinplate cans for sealed storage, thereby obtaining component A;

[0054] 2. The preparation of component B comprises the following steps:

[0055] The bio-based polyurethane curing agent (EI) and isophorone diisocyanate trimer are mixed evenly according to the measured amount, and then dividedly packaged into tinplate cans and sealed for storage, so as to obtain component B;

[0056] 3. The preparation of the coating comprises the following steps:

[0057] After component A and component B are evenly mixed, the coating can be applied to the pre-treated steel plate with a wet film applicator, and the coating is cured after the film is applied to obtain a fully cured coating.

[0058] Beneficial Effects

[0059] 1) The present invention prepares bio-based polyols by using renewable epoxy soybean oil and ricinoleic acid as starting materials, and modifies them into a bio-based polyurethane curing agent to increase the biomass content of the coating; the bio-based polyurethane curing agent is theoretically an 8-functionality structure, has multi-functionality, high activity and the function of increasing cross-linking density; at the same time, the internal structure of the bio-based polyurethane curing agent is a triglyceride structure and a long fatty carbon chain of the plant oil, so that it has the inherent characteristics of the flexibility of the plant oil molecular chain segment, and as a curing agent, the prepared coating has both toughness and strength;

[0060] 2) The present invention improves the weather resistance of the coating by introducing aspartic acid resin as an amino component to react with a bio-based curing agent to form a polyurethane-polyurea polymer linker; secondly, the aspartic acid resin has a sterically hindered secondary amino structure, which not only has lower reaction activity than a primary amino structure, but also has high strength, high weather resistance, low viscosity, and high solid content, thereby solving the shortcomings of the traditional primary amino structure polyurea, which has a too fast reaction speed and too short operation time; in addition, after the aspartic acid ester resin reacts with the bio-based polyurethane curing agent and the isophorone diisocyanate trimer curing agent to form a film, a large number of carbamate bonds and urea bonds are introduced to improve the hardness and adhesion of the coating;

[0061] 3) The present invention is carried out by (Ti3C2T x )Mxene is grafted and modified to prepare two-dimensional nanomaterial amino MXene, improve its dispersibility and reactivity in the coating system, and use its "nano barrier effect" to construct a "maze effect" in the coating to extend the penetration path of the corrosive medium, improve the salt spray corrosion resistance of the coating, and achieve long-term anti-corrosion effect;

[0062] 4) The present invention introduces an adhesion promoter, bis(3-trimethoxysilylpropyl)amine, whose molecular structure has a secondary amino functional group containing only one active hydrogen and six hydrolyzable alkoxy (methoxy) groups. During the curing process, the secondary amino group reacts with the NCO group of the curing agent to form a covalent bond, and the alkoxy groups at the two ends react with a large number of hydroxyl groups on the surface of the epoxy micaceous iron intermediate coating to form a covalent bond connection. Through the above-mentioned two-way reaction, the coating's bonding strength and water resistance and other properties are improved;

[0063] 5) By introducing single-terminal hydroxyl silicone oil, during the film-forming reaction, its terminal hydroxyl group reacts with the NCO group of the curing agent to form a covalent bond, and the other end of the PDMS long chain will spontaneously accumulate on the coating surface due to its relatively low surface energy, thereby improving the hydrophobicity, anti-fouling performance and easy-to-clean effect of the coating;

[0064] 6) After the coating of the present invention is completely cured, the pencil hardness can reach 3H, the adhesion is level 0, the artificial accelerated aging can reach 2000h, the salt spray resistance can reach 2100h, and the chemical resistance can reach 240h. It is suitable for use in the atmospheric environment of coastal and offshore areas with high salinity, and can achieve long-term protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0066] Figure 1 is a flow chart for preparing bio-based polyol (ER) in the present invention;

[0067] Figure 2 is a flow chart of the preparation of the bio-polyurethane prepolymer (EI) in the present invention;

[0068] Figure 3 The figure is a flow chart for the preparation of amino Mxene in the present invention. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] The present invention will be further described below in conjunction with the embodiments.

[0071] Example 1

[0072] This embodiment discloses a method for preparing a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating, comprising the following steps:

[0073] 1. The preparation of amino Mxene comprises the following steps:

[0074] (1) Take 1.0g of titanium carbide (Ti3C2T x )MXene multilayer nanosheets were added to a mixture of 30 mL ethanol and 10 mL deionized water;

[0075] (2) Add 1 mL of N-aminoethyl-γ-aminopropyltrimethoxysilane (KH792) to the above suspension and stir for 48 h at a stirring speed of 500 rpm;

[0076] (3) Next, the mixture obtained in the previous step was filtered through a 0.22 μm PVDF membrane and washed several times with deionized water and ethanol to remove unbound N-aminoethyl-γ-aminopropyltrimethoxysilane (KH792);

[0077] (4) Finally, the obtained product was vacuum-baked at 60°C for 12 h, taken out and ground into powder to obtain amino Mxene, which was then vacuum-stored for later use;

[0078] The molecular formula of amino Mxene is: (Ti3C2T x )-O3Si(CH2)3NH(CH2)3NH2;

[0079] The three-dimensional structure of amino Mxene is attached. Figure 3 ;

[0080] 2. The preparation of bio-based polyurethane curing agent (EI) comprises the following steps:

[0081] (a) 97.54 g (0.1 mol) of epoxidized soybean oil (ESO), 119.39 g (0.4 mol) of ricinoleic acid (RA) and 0.80 g of tetrabutylammonium bromide (TBAB) were put into a 500 mL three-necked flask, and reacted in a constant temperature oil bath at 120° C. for 6 h under mechanical stirring to obtain a yellow viscous bio-based polyol (ER) solution with a hydroxyl value of 203±3 mgKOH / g, which was set aside;

[0082] (b) 20.95 g of isophorone diisocyanate (IPDI) and 0.02 g of dibutyltin dilaurate (DBTDL) were put into a 250 mL three-necked flask; 21.70 g of the ER solution obtained in step (a) and 4.74 g of acetyl tributyl citrate (ATBC) were added dropwise to the above reaction flask through a constant pressure dropping funnel within 30 min, and the mixture was reacted in a constant temperature oil bath at 45 ° C for 3 h under mechanical stirring and nitrogen protection conditions, then the temperature was raised to 55 ° C and maintained for 2 h, and the material was discharged into a tinplate can and sealed to obtain a bio-based polyurethane curing agent (EI) having an NCO content of 9.7±0.3%;

[0083] The structural formula of ER is attached. Figure 1 ;

[0084] The structural formula of bio-based polyurethane curing agent is:

[0085]

[0086] Among them, R-NCO is

[0087] The three-dimensional structure diagram of bio-based polyurethane curing agent (EI) is attached Figure 2 ;

[0088] 3. The preparation of component A comprises the following steps:

[0089] 1) Weigh component A:

[0090] 50 g of polyaspartic acid ester resin; preferably, the polyaspartic acid ester resin is a combination of F52425 g and F15725 g produced by Feiyang Junyan;

[0091] 35 g of rutile titanium dioxide; preferably, the rutile titanium dioxide is NR9503 produced by Jinpu Titanium Industry;

[0092] 1.5 g of high-pigment carbon black; preferably, the high-pigment carbon black is MA-100 produced by Mitsubishi Chemical;

[0093] Amino Mxene 0.4 g;

[0094] 1.4 g of fumed nano-silicon dioxide; preferably, the fumed nano-silicon dioxide is TS-720;

[0095] 0.15 g of ultraviolet absorber; preferably, the ultraviolet absorber is UV-531 produced by BASF;

[0096] 0.15 g antioxidant; preferably, the antioxidant is BASF antioxidant 1010;

[0097] 1.6 g of adhesion promoter; preferably, the adhesion promoter is bis(3-trimethoxysilylpropyl)amine (KH-170);

[0098] 1.7 g of single-ended hydroxy silicone oil; preferably, the single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, X-22-176DX produced by Shin-Etsu of Japan;

[0099] 1.4 g of composite additive; preferably, the composite additive includes 0.5 g of defoamer, 0.6 g of dispersant and 0.3 g of leveling agent; preferably, the defoamer is BYK085; preferably, the leveling agent is BYK-333; preferably, the dispersant is BYK163;

[0100] 6.7 g of a mixed solvent; preferably, the mixed solvent is obtained by uniformly mixing butyl acetate and No. 100 solvent naphtha in a mass ratio of 1:1;

[0101] 2) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxyl silicone oil into a container according to metered amounts, and mechanically stirring to obtain a uniform mixed solution;

[0102] 3) adding rutile titanium dioxide, high-pigment carbon black, amino Mxene, fumed nano-silica, ultraviolet absorber and antioxidant to the mixed solution of step 2), first stirring and dispersing at a low speed, then adding zirconium dioxide beads as grinding media, and grinding with a sand mill to a fineness of less than 35 μm;

[0103] 4) filtering the fluid obtained by grinding in step 3), packaging it into tinplate cans, sealing it and storing it, thereby obtaining component A;

[0104] 4. The preparation of component B comprises the following steps:

[0105] ①Weigh component B:

[0106] Bio-based polyurethane curing agent (EI) 50g;

[0107] 50 g of isophorone diisocyanate trimer; preferably, the isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and the NCO content is 12±0.3%;

[0108] ② After the bio-based polyurethane curing agent (EI) and isophorone diisocyanate trimer are uniformly mixed according to the measured amount, they are divided into tinplate cans and sealed for storage to obtain component B;

[0109] 5. The preparation of the coating comprises the following steps:

[0110] Mix component A and component B in a mass ratio of 10:6.9, and then apply the coating to the pretreated Q235 low-carbon steel plate (150×70×1mm) with a wet film applicator. The coating thickness is 200μm. Curing for 7 days at a temperature of 23±2℃ and a relative humidity of 65±5% to obtain a fully cured coating.

[0111] Example 2

[0112] This embodiment discloses a method for preparing a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating, comprising the following steps:

[0113] 1. Preparation of amino Mxene, the method is the same as Example 1;

[0114] 2. The preparation of bio-based polyurethane curing agent (EI) comprises the following steps:

[0115] (a) 97.54 g (0.1 mol) of epoxidized soybean oil (ESO), 119.39 g (0.4 mol) of ricinoleic acid (RA) and 0.80 g of tetrabutylammonium bromide (TBAB) were put into a 500 mL three-necked flask, and reacted in a constant temperature oil bath at 120° C. for 6 h under mechanical stirring to obtain a yellow viscous bio-based polyol (ER) solution with a hydroxyl value of 203±3 mgKOH / g, which was set aside;

[0116] (b) 22.69 g of isophorone diisocyanate (IPDI) and 0.02 g of dibutyltin dilaurate (DBTDL) were put into a 250 mL three-necked flask; 21.70 g of the ER solution obtained in step (a) and 4.93 g of acetyl tributyl citrate (ATBC) were added dropwise to the above reaction flask through a constant pressure dropping funnel within 30 min, and the mixture was reacted in a constant temperature oil bath at 45 ° C for 3 h under mechanical stirring and nitrogen protection conditions, then the temperature was raised to 55 ° C and maintained for 2 h, and the material was discharged into a tinplate can and sealed to obtain a bio-based polyurethane curing agent (EI) with an NCO content of 10.7±0.3%;

[0117] 3. The preparation of component A comprises the following steps:

[0118] 1) Weigh component A:

[0119] 50 g of polyaspartic acid ester resin; preferably, the polyaspartic acid ester resin is a combination of F52025 g and F15725 g produced by Feiyang Junyan;

[0120] 35 g of rutile titanium dioxide; preferably, the rutile titanium dioxide is NR960 produced by Jinpu Titanium Industry;

[0121] 1.5 g of high-pigment carbon black; preferably, the high-pigment carbon black is MA-11 produced by Mitsubishi Chemical;

[0122] Amino Mxene 0.6 g;

[0123] 1.4 g of fumed nano-silicon dioxide; preferably, the fumed nano-silicon dioxide is Cabot M-5;

[0124] 0.2 g of ultraviolet absorber; preferably, the ultraviolet absorber is UV-326 produced by BASF;

[0125] 0.1 g of antioxidant; preferably, the antioxidant is BASF antioxidant 1010;

[0126] 1.7 g of adhesion promoter; preferably, the adhesion promoter is bis(3-trimethoxysilylpropyl)amine (KH-170);

[0127] 1.5 g of single-ended hydroxy silicone oil; preferably, the single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, X-22-170BX produced by Shin-Etsu of Japan;

[0128] 1.5 g of composite additive; preferably, the composite additive includes 0.7 g of defoamer, 0.5 g of dispersant and 0.3 g of leveling agent; preferably, the defoamer is Defom-6800; preferably, the leveling agent is BYK-333; preferably, the dispersant is BYK163;

[0129] 6.5 g of a mixed solvent; preferably, the mixed solvent is obtained by uniformly mixing butyl acetate and No. 100 solvent naphtha in a mass ratio of 1:1;

[0130] 2) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxyl silicone oil into a container according to metered amounts, and mechanically stirring to obtain a uniform mixed solution;

[0131] 3) adding rutile titanium dioxide, high-pigment carbon black, amino Mxene, fumed nano-silica, ultraviolet absorber and antioxidant to the mixed solution of step 2), first stirring and dispersing at a low speed, then adding zirconium dioxide beads as grinding media, and grinding with a sand mill to a fineness of less than 35 μm;

[0132] 4) filtering the fluid obtained by grinding in step 3), packaging it into tinplate cans, sealing it and storing it, thereby obtaining component A;

[0133] 4. The preparation of component B comprises the following steps:

[0134] ①Weigh component B:

[0135] Bio-based polyurethane curing agent (EI) 50g;

[0136] 50 g of isophorone diisocyanate trimer; preferably, the isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and the NCO content is 12±0.3%;

[0137] ② After the bio-based polyurethane curing agent (EI) and isophorone diisocyanate trimer are uniformly mixed according to the measured amount, they are divided into tinplate cans and sealed for storage to obtain component B;

[0138] 5. The preparation of the coating comprises the following steps:

[0139] Mix component A and component B in a mass ratio of 10:7.3, and then apply the coating to the pretreated Q235 low-carbon steel plate (150×70×1mm) with a wet film applicator. The coating thickness is 200μm. Curing for 7 days at a temperature of 23±2℃ and a relative humidity of 65±5% to obtain a fully cured coating.

[0140] Example 3

[0141] This embodiment discloses a method for preparing a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating, comprising the following steps:

[0142] 1. Preparation of amino Mxene, the method is the same as Example 1;

[0143] 2. The preparation of bio-based polyurethane curing agent (EI) comprises the following steps:

[0144] (a) 97.54 g (0.1 mol) of epoxidized soybean oil (ESO), 119.39 g (0.4 mol) of ricinoleic acid (RA) and 0.80 g of tetrabutylammonium bromide (TBAB) were put into a 500 mL three-necked flask, and reacted in a constant temperature oil bath at 120° C. for 6 h under mechanical stirring to obtain a yellow viscous bio-based polyol (ER) solution with a hydroxyl value of 203±3 mgKOH / g, which was set aside;

[0145] (b) 22.44 g of isophorone diisocyanate (IPDI) and 0.02 g of dibutyltin dilaurate (DBTDL) were put into a 250 mL three-necked flask; 21.70 g of the ER solution obtained in step (a) and 5.13 g of acetyl tributyl citrate (ATBC) were added dropwise to the above reaction flask through a constant pressure dropping funnel within 30 min, and the mixture was reacted in a constant temperature oil bath at 45 ° C for 3 h under mechanical stirring and nitrogen protection conditions, and then the temperature was raised to 55 ° C and maintained for 2 h, and the material was discharged into a tinplate can and sealed to obtain a bio-based polyurethane curing agent (EI) with an NCO content of 11.5±0.3%;

[0146] 3. The preparation of component A comprises the following steps:

[0147] 1) Weigh component A:

[0148] 50 g of polyaspartic acid resin; preferably, the polyaspartic acid resin is a combination of F15725 g and F520225 g produced by Feiyang Junyan;

[0149] 34 g of rutile titanium dioxide; preferably, the rutile titanium dioxide is NR960 produced by Jinpu Titanium Industry;

[0150] 1.7 g of high-pigment carbon black; preferably, the high-pigment carbon black is MA-100 produced by Mitsubishi Chemical;

[0151] Amino Mxene 0.8 g;

[0152] 1.3 g of fumed nano-silicon dioxide; preferably, the fumed nano-silicon dioxide is TS-720;

[0153] 0.1 g of ultraviolet absorber; preferably, the ultraviolet absorber is UV-326 produced by BASF;

[0154] 0.2 g antioxidant; preferably, the antioxidant is BASF antioxidant 1010;

[0155] 2 g of adhesion promoter; preferably, the adhesion promoter is bis(3-trimethoxysilylpropyl)amine (KH-170);

[0156] 2 g of single-ended hydroxy silicone oil; preferably, the single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, X-22-170BX produced by Shin-Etsu of Japan;

[0157] 1.2 g of composite additive; preferably, the composite additive includes 0.4 g of defoamer, 0.5 g of dispersant and 0.3 g of leveling agent; preferably, the defoamer is BYK085; preferably, the leveling agent is BYK-306; preferably, the dispersant is BYK163;

[0158] 6 g of mixed solvent; preferably, the mixed solvent is butyl acetate and No. 100 solvent naphtha mixed in a mass ratio of 1:1;

[0159] 2) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxyl silicone oil into a container according to metered amounts, and mechanically stirring to obtain a uniform mixed solution;

[0160] 3) adding rutile titanium dioxide, high-pigment carbon black, amino Mxene, fumed nano-silica, ultraviolet absorber and antioxidant to the mixed solution of step 2), first stirring and dispersing at a low speed, then adding zirconium dioxide beads as grinding media, and grinding with a sand mill to a fineness of less than 35 μm;

[0161] 4) filtering the fluid obtained by grinding in step 3), packaging it into tinplate cans, sealing it and storing it, thereby obtaining component A;

[0162] 4. The preparation of component B comprises the following steps:

[0163] ①Weigh component B:

[0164] Bio-based polyurethane curing agent (EI) 50g;

[0165] 50 g of isophorone diisocyanate trimer; preferably, the isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and the NCO content is 12±0.3%;

[0166] ② After the bio-based polyurethane curing agent (EI) and isophorone diisocyanate trimer are uniformly mixed according to the measured amount, they are divided into tinplate cans and sealed for storage to obtain component B;

[0167] 5. The preparation of the coating comprises the following steps:

[0168] Mix component A and component B in a mass ratio of 10:6.9, and then apply the coating to the pretreated Q235 low-carbon steel plate (150×70×1mm) with a wet film applicator. The coating thickness is 200μm. Curing for 7 days at a temperature of 23±2℃ and a relative humidity of 65±5% to obtain a fully cured coating.

[0169] Example 4

[0170] This embodiment discloses a method for preparing a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating, comprising the following steps:

[0171] 1. Preparation of amino Mxene, the method is the same as Example 1;

[0172] 2. Preparation of bio-based polyurethane curing agent (EI), the method is the same as Example 3;

[0173] 3. The preparation of component A comprises the following steps:

[0174] 1) Weigh component A:

[0175] 50 g of polyaspartic acid resin; preferably, the polyaspartic acid resin is a combination of F15725 g and F520225 g produced by Feiyang Junyan;

[0176] 34 g of rutile titanium dioxide; preferably, the rutile titanium dioxide is NR960 produced by Jinpu Titanium Industry;

[0177] 1.6 g of high-pigment carbon black; preferably, the high-pigment carbon black is MA-100 produced by Mitsubishi Chemical;

[0178] Amino Mxene 1g;

[0179] 1.3 g of fumed nano-silicon dioxide; preferably, the fumed nano-silicon dioxide is TS-720;

[0180] 0.1 g of ultraviolet absorber; preferably, the ultraviolet absorber is UV-326 produced by BASF;

[0181] 0.2 g antioxidant; preferably, the antioxidant is BASF antioxidant 1010;

[0182] 2 g of adhesion promoter; preferably, the adhesion promoter is bis(3-trimethoxysilylpropyl)amine (KH-170);

[0183] 2 g of single-ended hydroxy silicone oil; preferably, the single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, X-22-170BX produced by Shin-Etsu of Japan;

[0184] 1.2 g of composite additive; preferably, the composite additive includes a defoamer, a dispersant and a leveling agent; preferably, the defoamer is BYK085; preferably, the leveling agent is BYK-306; preferably, the dispersant is BYK163;

[0185] 6 g of mixed solvent; preferably, the mixed solvent is butyl acetate and No. 100 solvent naphtha mixed in a mass ratio of 1:1;

[0186] 2) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxyl silicone oil into a container according to metered amounts, and mechanically stirring to obtain a uniform mixed solution;

[0187] 3) adding rutile titanium dioxide, high-pigment carbon black, amino Mxene, fumed nano-silica, ultraviolet absorber and antioxidant to the mixed solution of step 2), first stirring and dispersing at a low speed, then adding zirconium dioxide beads as grinding media, and grinding with a sand mill to a fineness of less than 35 μm;

[0188] 4) filtering the fluid obtained by grinding in step 3), packaging it into tinplate cans, sealing it and storing it, thereby obtaining component A;

[0189] 4. The preparation of component B comprises the following steps:

[0190] ①Weigh component B:

[0191] Bio-based polyurethane curing agent (EI) 50g;

[0192] 50 g of isophorone diisocyanate trimer; preferably, the isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and the NCO content is 12±0.3%;

[0193] ② After the bio-based polyurethane curing agent (EI) and isophorone diisocyanate trimer are uniformly mixed according to the measured amount, they are divided into tinplate cans and sealed for storage to obtain component B;

[0194] 5. The preparation of the coating comprises the following steps:

[0195] Mix component A and component B in a mass ratio of 10:6.9, and then apply the coating to the pretreated Q235 low-carbon steel plate (150×70×1mm) with a wet film applicator. The coating thickness is 200μm. Curing for 7 days at a temperature of 23±2℃ and a relative humidity of 65±5% to obtain a fully cured coating.

[0196] Example 5

[0197] This embodiment discloses a method for preparing a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating, comprising the following steps:

[0198] 1. Preparation of amino Mxene, the method is the same as Example 1;

[0199] 2. Preparation of bio-based polyurethane curing agent (EI), the method is the same as Example 3;

[0200] 3. The preparation of component A comprises the following steps:

[0201] 1) Weigh component A:

[0202] 45 g of polyaspartic acid ester resin; preferably, the polyaspartic acid ester resin is a combination of F520, F524, F5202 and F157 produced by Feiyang Junyan;

[0203] 30 g of rutile titanium dioxide; preferably, the rutile titanium dioxide is a combination of NR9503 and NR960 produced by Jinpu Titanium Industry;

[0204] 1 g of high-pigment carbon black; preferably, the high-pigment carbon black is a combination of MA-100 and MA-11 produced by Mitsubishi Chemical;

[0205] Amino Mxene 0.7 g;

[0206] 0.5 g of fumed nano-silicon dioxide; preferably, the fumed nano-silicon dioxide is a combination of Cabot M-5 and TS-720;

[0207] 0.1 g of ultraviolet absorber; preferably, the ultraviolet absorber is a combination of UV-531 and UV-326 produced by BASF;

[0208] 0.1 g of antioxidant; preferably, the antioxidant is BASF antioxidant 1010;

[0209] 1 g of adhesion promoter; preferably, the adhesion promoter is bis(3-trimethoxysilylpropyl)amine (KH-170);

[0210] 1 g of single-ended hydroxy silicone oil; preferably, the single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, which is a combination of X-22-170BX and X-22-176DX produced by Shin-Etsu of Japan;

[0211] 1g of composite additive; preferably, the composite additive comprises a defoamer, a dispersant and a leveling agent; preferably, the defoamer is a combination of BYK085 and Defom-6800; preferably, the leveling agent is a combination of BYK-333 and BYK-306; preferably, the dispersant is a combination of BYK-111 and BYK163;

[0212] 4 g of a mixed solvent; preferably, the mixed solvent is obtained by uniformly mixing butyl acetate and No. 100 solvent naphtha in a mass ratio of 1:1;

[0213] 2) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxyl silicone oil into a container according to metered amounts, and mechanically stirring to obtain a uniform mixed solution;

[0214] 3) adding rutile titanium dioxide, high-pigment carbon black, amino Mxene, fumed nano-silica, ultraviolet absorber and antioxidant to the mixed solution of step 2), first stirring and dispersing at a low speed, then adding zirconium dioxide beads as grinding media, and grinding with a sand mill to a fineness of less than 35 μm;

[0215] 4) filtering the fluid obtained by grinding in step 3), packaging it into tinplate cans, sealing it and storing it, thereby obtaining component A;

[0216] 4. The preparation of component B comprises the following steps:

[0217] ①Weigh component B:

[0218] Bio-based polyurethane curing agent (EI) 50g;

[0219] 50 g of isophorone diisocyanate trimer; preferably, the isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and the NCO content is 12±0.3%;

[0220] ② After the bio-based polyurethane curing agent (EI) and isophorone diisocyanate trimer are uniformly mixed according to the measured amount, they are divided into tinplate cans and sealed for storage to obtain component B;

[0221] 5. The preparation of the coating comprises the following steps:

[0222] Mix component A and component B in a mass ratio of 10:6.5, and then apply the coating to the pretreated Q235 low-carbon steel plate (150×70×1mm) with a wet film applicator. The coating thickness is 200μm. Curing for 7 days at a temperature of 23±2℃ and a relative humidity of 65±5% to obtain a fully cured coating.

[0223] Example 6

[0224] This embodiment discloses a method for preparing a bio-based polyurethane curing agent and an amino Mxene anti-corrosion coating, comprising the following steps:

[0225] 1. Preparation of amino Mxene, the method is the same as Example 1;

[0226] 2. Preparation of bio-based polyurethane curing agent (EI), the method is the same as Example 3;

[0227] 3. The preparation of component A comprises the following steps:

[0228] 1) Weigh component A:

[0229] 55 g of polyaspartic acid ester resin; preferably, the polyaspartic acid ester resin is F520 produced by Feiyang Junyan;

[0230] 40 g of rutile titanium dioxide; preferably, the rutile titanium dioxide is NR9503 produced by Jinpu Titanium Industry;

[0231] 2 g of high-pigment carbon black; preferably, the high-pigment carbon black is MA-100 produced by Mitsubishi Chemical;

[0232] Amino Mxene 0.9 g;

[0233] 2 g of fumed nano-silicon dioxide; preferably, the fumed nano-silicon dioxide is Cabot M-5;

[0234] 0.3 g of ultraviolet absorber; preferably, the ultraviolet absorber is UV-531 produced by BASF;

[0235] 0.3 g antioxidant; preferably, the antioxidant is BASF antioxidant 1010;

[0236] 2 g of adhesion promoter; preferably, the adhesion promoter is bis(3-trimethoxysilylpropyl)amine (KH-170);

[0237] 3 g of single-ended hydroxy silicone oil; preferably, the single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, X-22-170BX produced by Shin-Etsu of Japan;

[0238] 4 g of composite additive; preferably, the composite additive includes a defoamer, a dispersant and a leveling agent; preferably, the defoamer is BYK085; preferably, the leveling agent is BYK-333; preferably, the dispersant is BYK-111;

[0239] 10 g of a mixed solvent; preferably, the mixed solvent is obtained by uniformly mixing butyl acetate and No. 100 solvent naphtha in a mass ratio of 1:1;

[0240] 2) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxyl silicone oil into a container according to metered amounts, and mechanically stirring to obtain a uniform mixed solution;

[0241] 3) adding rutile titanium dioxide, high-pigment carbon black, amino Mxene, fumed nano-silica, ultraviolet absorber and antioxidant to the mixed solution of step 2), first stirring and dispersing at a low speed, then adding zirconium dioxide beads as grinding media, and grinding with a sand mill to a fineness of less than 35 μm;

[0242] 4) filtering the fluid obtained by grinding in step 3), packaging it into tinplate cans, sealing it and storing it, thereby obtaining component A;

[0243] 4. The preparation of component B comprises the following steps:

[0244] ①Weigh component B:

[0245] Bio-based polyurethane curing agent (EI) 50g;

[0246] 50 g of isophorone diisocyanate trimer; preferably, the isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and the NCO content is 12±0.3%;

[0247] ② After the bio-based polyurethane curing agent (EI) and isophorone diisocyanate trimer are uniformly mixed according to the measured amount, they are divided into tinplate cans and sealed for storage to obtain component B;

[0248] 5. The preparation of the coating comprises the following steps:

[0249] Mix component A and component B in a mass ratio of 10:7.5, and then apply the coating to the pretreated Q235 low-carbon steel plate (150×70×1mm) with a wet film applicator. The coating thickness is 200μm. Curing for 7 days at a temperature of 23±2℃ and a relative humidity of 65±5% to obtain a fully cured coating.

[0250] Comparative Example 1

[0251] This comparative example 1 discloses a method for preparing a coating, comprising the following steps:

[0252] 1. Preparation of bio-based polyurethane curing agent (EI), the method is the same as Example 3;

[0253] 2. The preparation of component A comprises the following steps:

[0254] 1) Weigh component A:

[0255] 50 g of polyaspartic acid resin; preferably, the polyaspartic acid resin is a combination of F15725 g and F520225 g produced by Feiyang Junyan;

[0256] 34.6 g of rutile titanium dioxide; preferably, the rutile titanium dioxide is NR960 produced by Jinpu Titanium Industry;

[0257] 2 g of high-pigment carbon black; preferably, the high-pigment carbon black is MA-100 produced by Mitsubishi Chemical;

[0258] 1.3 g of fumed nano-silicon dioxide; preferably, the fumed nano-silicon dioxide is TS-720;

[0259] 0.1 g of ultraviolet absorber; preferably, the ultraviolet absorber is UV-326 produced by BASF;

[0260] 0.2 g antioxidant; preferably, the antioxidant is BASF antioxidant 1010;

[0261] 2 g of adhesion promoter; preferably, the adhesion promoter is bis(3-trimethoxysilylpropyl)amine (KH-170);

[0262] 2 g of single-ended hydroxy silicone oil; preferably, the single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, X-22-170BX produced by Shin-Etsu of Japan;

[0263] 1.2 g of composite additive; preferably, the composite additive includes a defoamer, a dispersant and a leveling agent; preferably, the defoamer is BYK085; preferably, the leveling agent is BYK-306; preferably, the dispersant is BYK163;

[0264] 6 g of mixed solvent; preferably, the mixed solvent is butyl acetate and No. 100 solvent naphtha mixed in a mass ratio of 1:1;

[0265] 2) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxyl silicone oil into a container according to metered amounts, and mechanically stirring to obtain a uniform mixed solution;

[0266] 3) adding rutile titanium dioxide, high-pigment carbon black, ultraviolet absorber and antioxidant to the mixed solution of step 2), first stirring at a low speed to disperse evenly, then adding zirconium dioxide beads as grinding media, and grinding with a sand mill to a fineness of less than 35 μm;

[0267] 4) filtering the fluid obtained by grinding in step 3), packaging it into tinplate cans, sealing it and storing it, thereby obtaining component A;

[0268] 3. Preparation of component B, comprising the following steps:

[0269] ①Weigh component B:

[0270] Bio-based polyurethane curing agent (EI) 50g;

[0271] 50 g of isophorone diisocyanate trimer; preferably, the isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and the NCO content is 12±0.3%;

[0272] ② After the bio-based polyurethane curing agent (EI) and isophorone diisocyanate trimer are uniformly mixed according to the measured amount, they are divided into tinplate cans and sealed for storage to obtain component B;

[0273] 4. The preparation of the coating comprises the following steps:

[0274] Mix component A and component B in a mass ratio of 10:6.9, and then apply the coating to the pretreated Q235 low-carbon steel plate (150×70×1mm) with a wet film applicator. The coating thickness is 200μm. Curing for 7 days at a temperature of 23±2℃ and a relative humidity of 65±5% to obtain a fully cured coating.

[0275] It can be seen that in Comparative Example 1, component A does not contain amino Mxene.

[0276] Comparative Example 2

[0277] A commercially available acrylic polyurethane topcoat was used and the coating was applied to a pretreated Q235 mild steel plate (150×70×1 mm) using a wet film applicator. The coating thickness was 200 μm and the coating was cured for 7 days at a temperature of 23±2°C and a relative humidity of 65±5% to obtain a fully cured coating.

[0278] Experimental example

[0279] The coatings of Examples 1 to 6 and Comparative Examples 1 to 2 were tested for performance, and the results are shown in Table 1;

[0280] Test method:

[0281] Determination of non-volatile matter content: refer to GB / T 1725-2007 "Determination of non-volatile matter content of paints, varnishes and plastics";

[0282] Pencil hardness test: refer to GB / T 6739-1996 "Pencil hardness test method for paint film";

[0283] Adhesion test: refer to GB / T 9286-2021 "Scratch test for paints and varnishes";

[0284] Contact angle test: The test was conducted at room temperature using a contact angle tester (JC2000D2), the water drop volume was 5 μL, and the experimental value was the average of 5 parallel tests;

[0285] Abrasion resistance test: The coating was tested on a pre-treated Q235 low carbon steel plate (100×100×1mm) in accordance with GB / T 1768-2006 “Determination of abrasion resistance of paints and varnishes - Rotating rubber grinding wheel method”;

[0286] Artificial aging performance test: refer to GB T 1865-2009 "Artificial weathering and artificial radiation exposure of paints and varnishes";

[0287] Salt spray resistance test: Refer to GB / T 1771-2007 "Determination of neutral salt spray resistance of paints and varnishes" for neutral salt spray resistance;

[0288] Chemical resistance test: refer to GB / T 9274-1988 "Determination of resistance of paints and varnishes to liquid media" immersion method, the solution used is 5% NaOH solution and 5% H2SO4 solution;

[0289] Table 1 Performance test results of coatings of Examples 1 to 6 and Comparative Examples 1 to 2

[0290]

[0291] As can be seen from the data in Table 1, the coating of the present invention uses aspartic acid ester as a secondary amine component to react with a bio-based polyurethane curing agent and an isophorone diisocyanate trimer to form a polyurethane-polyurea type polymer linker, and the coating made of amino Mxene as a two-dimensional nanomaterial has better performance than the coating without amino Mxene and the commercially available acrylic polyurethane topcoat;

[0292] The coating of the present invention has a mass loss of only 20 mg after abrasion resistance test, which is much less than the commercially available acrylic polyurethane topcoat; the coating of the present invention has a contact angle with water greater than 95°, and is a hydrophobic coating; the coating of the present invention is resistant to artificial aging for up to 2000 hours, while the commercially available acrylic polyurethane topcoat peels, cracks, and powders after 1000 hours, and the color changes by more than 2 levels; the coating embodiments 3 to 6 of the present invention have a salt spray resistance of up to 2100 hours, while the commercially available acrylic polyurethane topcoat can only withstand 930 hours; the coating of the present invention has a chemical resistance of up to 240 hours, without bubbles or peeling, which is much greater than comparative examples 1 and 2;

[0293] The present invention prepares bio-based polyols by using renewable epoxy soybean oil and ricinoleic acid as starting materials, and modifies them into a bio-based polyurethane curing agent to increase the biomass content of the coating; the bio-based polyurethane curing agent is theoretically an 8-functionality structure, has multi-functionality, high activity and the function of increasing cross-linking density; at the same time, the internal molecule of the bio-based polyurethane curing agent is a triglyceride structure and a long fatty carbon chain of the plant oil, so that it has the inherent characteristics of the flexibility of the plant oil molecular chain segment, and as a curing agent, the prepared coating has both toughness and strength; by introducing aspartic acid resin as an amino component and the bio-based curing agent The reaction forms a polyurethane-polyurea polymer linker, which improves the weather resistance of the coating. Secondly, the aspartic acid resin has a sterically hindered secondary amine structure, which not only has lower reaction activity than the primary amino structure, but also has high strength, high weather resistance, low viscosity, and high solid content, which solves the shortcomings of the traditional primary amino structure polyurea that the reaction speed is too fast and the operation time is too short. In addition, after the aspartic acid ester resin reacts with the bio-based polyurethane curing agent and the isophorone diisocyanate trimer curing agent to form a film, a large number of urethane bonds and urea bonds are introduced to improve the hardness and adhesion of the coating. By x)Mxene is grafted and modified to prepare two-dimensional nanomaterial amino MXene, improve its dispersibility and reactivity in the coating system, and use its "nano barrier effect" to construct a "maze effect" in the coating to extend the penetration path of the corrosive medium, improve the salt spray corrosion resistance of the coating, and achieve long-term anti-corrosion effect; by introducing the adhesion promoter bis (3-trimethoxysilylpropyl) amine, its molecular structure has a secondary amino functional group containing only one active hydrogen and 6 hydrolyzable alkoxy (methoxy) groups. During the curing process, its secondary amino group reacts with the NCO group of the curing agent to form a covalent bond, and the alkoxy groups at the two ends react with the epoxy cloud A large number of hydroxyl groups on the surface of the iron intermediate coating undergo coupling reaction to form covalent bond connections; through the above-mentioned two-way reaction, the bonding strength and water resistance of the coating are improved; by introducing single-terminal hydroxy silicone oil, during the film-forming reaction, its terminal hydroxyl group reacts with the NCO group of the curing agent to form a covalent bond, and the other end PDMS long chain will spontaneously accumulate on the coating surface due to its relatively low surface energy, thereby improving the hydrophobicity, anti-fouling performance and easy-to-clean effect of the coating; after the coating of the present invention is completely cured, the pencil hardness can reach 3H, the adhesion is level 0, the artificial accelerated aging can reach 2000h, the salt spray resistance can reach 2100h, and the chemical resistance can reach 240h.

[0294] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. Bio-based polyurethane curing agent and amino Mxene anti-corrosion coating, characterized in that: Comprising component A and component B; The component A comprises the following components in parts by weight: 45-55 parts of polyaspartic acid resin; 30-40 parts of rutile titanium dioxide; 1-2 parts of high pigment carbon black; Amino Mxene 0.4-1 part; Its molecular formula is: (Ti3C2T x )-O3Si(CH2)3NH(CH2)3NH2; 0.5-2 parts of fumed nano-silicon dioxide; 0.1 to 0.3 parts of ultraviolet absorber; 0.1-0.3 parts of antioxidant; 1-2 parts of adhesion promoter; 1 to 3 parts of mono-terminated hydroxyl silicone oil; 1 to 4 parts of composite additives; 4 to 10 parts of mixed solvent; The component B comprises the following components: Bio-based polyurethane curing agent; its structural formula is: Among them, R-NCO is Isophorone diisocyanate trimer; The mass ratio of bio-based polyurethane curing agent to isophorone diisocyanate trimer is 5:5; The mass ratio of the coating component A to the component B is 10:6.5-7.

5.

2. The bio-based polyurethane curing agent and amino Mxene anti-corrosion coating according to claim 1, characterized in that: The polyaspartic acid ester resin is one of F520, F524, F5202, and F157, or a combination of two or more thereof; The rutile titanium dioxide is one of NR9503 and NR960 or a combination of the two; The high-color carbon black is one of MA-100 and MA-11, or a combination of the two; The fumed nano-silica is one of Cabot M-5 and TS-720 or a combination of the two; The ultraviolet absorber is one of UV-531 and UV-326 or a combination of the two; The single-ended hydroxy silicone oil is single-ended monohydroxy PDMS or single-ended dihydroxy PDMS, and is one of X-22-170BX and X-22-176DX or a combination of the two.

3. The bio-based polyurethane curing agent and amino Mxene anti-corrosion coating according to claim 1, characterized in that: The antioxidant is BASF antioxidant 1010; The adhesion promoter is bis(3-trimethoxysilylpropyl)amine; The mixed solvent is obtained by uniformly mixing butyl acetate and No. 100 solvent naphtha in a mass ratio of 1:1; The isophorone diisocyanate trimer is Vestanat T1890E produced by Evonik, and has an NCO content of 12±0.3%.

4. The bio-based polyurethane curing agent and amino Mxene anti-corrosion coating according to claim 1, characterized in that: The composite auxiliary agent comprises a defoamer, a dispersant and a leveling agent.

5. The bio-based polyurethane curing agent and amino Mxene anti-corrosion coating according to claim 4, characterized in that: The defoamer is at least one of BYK085 and Defom-6800 or a combination of the two; The leveling agent is at least one of BYK-333 and BYK-306, or a combination of the two; The dispersant is at least one of BYK-111 and BYK163 or a combination of two thereof.

6. The bio-based polyurethane curing agent and amino Mxene anti-corrosion coating according to claim 1, characterized in that: The preparation method of the bio-based polyurethane curing agent comprises the following steps: (a) taking epoxidized soybean oil, ricinoleic acid and tetrabutylammonium bromide, reacting them in a constant temperature oil bath under stirring to obtain a yellow viscous bio-based polyol solution for standby use; (b) isophorone diisocyanate and dibutyltin dilaurate are mixed; the bio-based polyol solution obtained in step (a) and acetyl tributyl citrate are added dropwise to the mixture, and the mixture is reacted in a constant temperature oil bath under mechanical stirring and nitrogen protection conditions, and then the temperature is increased and maintained, and finally the material is discharged into a tinplate can and sealed for storage to obtain a bio-based polyurethane curing agent.

7. The bio-based polyurethane curing agent and amino Mxene anti-corrosion coating according to claim 1, characterized in that: The preparation method of amino Mxene comprises the following steps: (1) Take titanium carbide (Ti3C2T x )MXene multilayer nanosheets were added to a mixture of ethanol and deionized water; (2) adding N-aminoethyl-γ-aminopropyltrimethoxysilane to the above suspension and stirring continuously; (3) Next, the mixture obtained in the previous step was filtered through a PVDF membrane and washed several times with deionized water and ethanol to remove unbound N-aminoethyl-γ-aminopropyltrimethoxysilane; (4) Finally, the obtained product is baked in vacuum and ground into powder to obtain amino Mxene, which is then stored in vacuum for future use.

8. A method for preparing the bio-based polyurethane curing agent and amino Mxene anti-corrosion coating as claimed in claim 1, characterized in that: The following steps are involved:

1. The preparation of component A comprises the following steps: 1) adding polyaspartic acid ester resin, mixed solvent, composite auxiliary agent, adhesion promoter and single-end hydroxyl silicone oil into a container according to metered amounts, and stirring to obtain a uniform mixed solution; 2) adding rutile titanium dioxide, high-pigment carbon black, amino Mxene, fumed nano-silica, ultraviolet absorber and antioxidant to the mixed solution of step 1), stirring and dispersing them uniformly, and then adding zirconium dioxide beads as grinding media for grinding; 3) filtering the fluid obtained by grinding in step 2), packaging and sealing for storage, thereby obtaining component A; 2. The preparation of component B comprises the following steps: The bio-based polyurethane curing agent and isophorone diisocyanate trimer are mixed evenly according to the measured amount, and then packaged and sealed for storage to obtain component B; 3. The preparation of the coating comprises the following steps: After component A and component B are evenly mixed, the coating can be applied to the pre-treated steel plate, and the coating is cured to obtain a fully cured coating.

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