Method for preparing environmentally friendly coating using modified polyaspartic acid ester resin and isocyanate and application thereof

Abstract

The present invention provides a method for preparing an environmentally friendly coating using a modified polyaspartic acid ester resin and an isocyanate and its application, belonging to the field of coating technology. The environmentally friendly coating includes the following raw materials by mass fraction: component A: 22-27 parts of modified polyaspartic acid ester resin, 6-11 parts of polyaspartic acid ester resin, 13-18 parts of long-chain olefin-modified dicyclopentadiene resin, 2-5 parts of zinc phosphate, 1-3 parts of dispersant, 2-5 parts of adhesion promoter, and 12-18 parts of modified mixed filler; component B: 75-80 parts of toluene diisocyanate, 20-30 parts of HDI trimer, 3-5 parts of defoamer, and 2-3 parts of leveling agent. The environmentally friendly coating prepared by the present invention has excellent corrosion resistance, wear resistance, and bending resistance, and has good adhesion on PE T plastic surfaces.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and particularly relates to a method for preparing an environmentally friendly coating by using modified polyaspartic acid ester resin and isocyanate, and application thereof. Background Art

[0002] In recent years, polyaspartic acid ester coatings, an emerging aliphatic-based high-performance coating with a moderate reaction rate and excellent weather resistance, have emerged in the field of polyurea technology. Known as the "third generation of polyurea," the emergence of these coatings signals that the coatings industry is moving towards a greener and healthier direction while pursuing high performance.

[0003] Currently, polyaspartic acid coatings are mostly used as topcoats, combined with specialized anti-corrosion primers to form composite coating systems. While this dual-layer protection provides excellent corrosion protection, it requires at least two application passes, increasing overall construction costs and adding uncertainty and complexity to the process. Frequent maintenance work is particularly impractical and financially burdensome for facilities operating in coastal or offshore environments.

[0004] PET plastic is used as packaging material for goods shipped at sea, such as protective films and containers. To protect these packaging materials from seawater and moisture, they require a coating on their exterior surfaces. In maritime environments, PET plastic substrates are susceptible to corrosion, degradation, and degradation due to salt spray, high humidity, intense sunlight, and extreme temperature fluctuations. However, existing polyaspartic acid coatings do not provide ideal adhesion to PET plastic substrates.

[0005] Therefore, there is an urgent need for an environmentally friendly coating that is suitable for marine environments and has high adhesion to PET plastic equipment. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing an environmentally friendly coating from a modified polyaspartic acid ester resin and isocyanate and its application.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing an environmentally friendly coating by using a modified polyaspartic acid ester resin and isocyanate comprises the following steps:

[0009] (1) Weigh the following raw materials in parts by mass:

[0010] Component A: 22-27 parts of modified polyaspartic acid ester resin, 6-11 parts of polyaspartic acid ester resin, 13-18 parts of long-chain olefin modified dicyclopentadiene resin, 2-5 parts of zinc phosphate, 1-3 parts of dispersant, 2-5 parts of adhesion promoter, and 12-18 parts of modified mixed filler;

[0011] Component B: 75-80 parts of toluene diisocyanate, 20-30 parts of HDI trimer, 3-5 parts of defoamer, 2-3 parts of leveling agent;

[0012] (2) Mixing the modified polyaspartic acid ester resin, the long-chain olefin-modified dicyclopentadiene resin, the polyaspartic acid ester resin, the zinc phosphate, the modified mixed filler, the dispersant and the adhesion promoter, heating to 45-50° C., rotating at 3000-4000 rpm, and stirring for 20-30 minutes to obtain component A;

[0013] (3) Mix toluene diisocyanate, HDI trimer, defoamer and leveling agent, stir at a speed of 2000-2500 rpm for 10-20 minutes to obtain component B.

[0014] Furthermore, the polyaspartic acid ester resin has an NH equivalent weight of 1140 g / mol and was purchased from Zhuhai Feiyang Chemical Co., Ltd. under the model number of aspartic acid polyurea resin D2925.

[0015] Furthermore, HDI trimer, Wuhan Huaxiang Kejie Biotechnology Co., Ltd., hexamethylene diisocyanate-based polyisocyanate, model HT-100.

[0016] Furthermore, the preparation method of the long-chain olefin-modified dicyclopentadiene resin comprises the following steps:

[0017] S1: Add dicyclopentadiene, 1-dodecene, and toluene to a stainless steel hot polymerization reactor. After nitrogen displacement to remove air from the reactor, the reactor is pressurized to 0.5-0.8 MPa and reacted at 180-185°C for 6-8 hours. After cooling to room temperature, unreacted olefins and toluene are removed by vacuum distillation to obtain a long-chain olefin-modified dicyclopentadiene hot polymerization resin.

[0018] S2: Add a long-chain olefin-modified dicyclopentadiene thermal polymer resin, toluene, and a nickel-supported catalyst in a mass ratio of 100: (120-140): 1 into a stainless steel reactor, use hydrogen to replace the air multiple times, raise the temperature to 160-165°C, introduce hydrogen to increase the pressure to 1.3-1.5 MPa, hydrogenate for 4-5 hours, cool and release the pressure, remove the toluene by vacuum distillation, and obtain a long-chain olefin-modified dicyclopentadiene resin.

[0019] Furthermore, the mass ratio of dicyclopentadiene:1-dodecene:toluene is (7-9):(1-3):10.

[0020] Dicyclopentadiene with a purity of 90% was purchased from Shandong Maojun Chemical.

[0021] The nickel-supported catalyst was purchased from Shanghai Xunkai New Material Technology Co., Ltd., model number SNCAT-8800P.

[0022] Furthermore, the preparation method of the modified polyaspartic acid ester resin is:

[0023] (1) 12 parts by mass of silica sol and 2.8-3.3 parts by mass of N-[3-(trimethoxysilyl)propyl]ethylenediamine were mixed, stirred and reacted at 64-68°C for 26-30 hours, 1.3-1.5 parts by mass of methyl methacrylate were added, stirred and reacted at 72-76°C for 26-30 hours, 1-1.2 parts by mass of ethylenediamine were added, stirred and reacted at 25-30°C for 26-30 hours to obtain amino-functionalized silica sol;

[0024] (2) Mixing amino-functionalized silica sol and hexamethylene diisocyanate, reacting at 80-85°C for 2-3 hours, cooling to 15-20°C, and adding hexamethylenediamine dropwise for end-capping to obtain amino-functionalized silica sol branched modified hexamethylenediamine reaction solution;

[0025] (3) Diethyl maleate is added dropwise to the reaction solution of amino-functionalized silica sol branched modified hexamethylenediamine. After the addition is completed, the temperature is raised to 102-105°C and the reaction is carried out at a constant temperature for 15-20 hours. Then, the unreacted raw materials are removed by vacuum rotary evaporation to obtain a modified polyaspartic acid ester resin.

[0026] The mass fraction of silicon dioxide in the silica sol is 25-35%. Linyi Kehan ​​Silicon Products Co., Ltd. Model: KHZCM-30.

[0027] N-[3-(Trimethoxysilyl)propyl]ethylenediamine, CAS: 1760-24-3.

[0028] Furthermore, the mass ratio of silica sol to hexamethylene diisocyanate is (0.75-0.82):1.

[0029] The molar ratio of hexamethylenediamine and hexamethylene diisocyanate is (1.2-1.5):1.

[0030] The molar ratio of diethyl maleate to hexamethylenediamine is 1:(2.5-2.8).

[0031] At present, the coating prepared by polyaspartic acid ester resin is mostly used as topcoat, is used in conjunction with special anticorrosive primer, and the coating anticorrosive performance of polyaspartic acid ester resin preparation is not good when used alone. The present invention can improve the salt spray resistance of coating by compounding polyaspartic acid ester resin with modified polyaspartic acid ester resin. Modified polyaspartic acid ester resin and polyaspartic acid ester resin form more complicated cross-linked network, can provide better anti-permeability, improve the anticorrosive performance of coating. But after polyaspartic acid ester resin and modified polyaspartic acid ester resin are compounded, the chemical medium resistance of coating is not ideal.

[0032] The present invention further adds long-chain olefin modified dicyclopentadiene resin, can improve the chemical medium resistance of coating.Long-chain olefin modified dicyclopentadiene resin and modified polyaspartic acid ester resin and polyaspartic acid ester resin have good compatibility, long-chain olefin modified dicyclopentadiene resin itself has good chemical stability, acid-base medium is had to stronger resistance, long-chain olefin modified dicyclopentadiene resin and polyaspartic acid ester resin, modified polyaspartic acid ester resin form more dense three-dimensional network structure in coating system, improve high cross-linking density, can effectively improve the compactness and stability of coating, and then strengthen its acid and alkali resistance.Improve the adhesive power of coating at PET plastic surface simultaneously.

[0033] Furthermore, the preparation method of the modified mixed filler is:

[0034] (1) Mixing nano-silicon dioxide, nano-lanthanum oxide, and nano-aluminum oxide to obtain a mixed filler;

[0035] (2) Mixing a mixed filler in a mass ratio of 1: (0.1-0.2): (8-10), a silane coupling agent KH560 and an ethanol aqueous solution with a mass fraction of 60-70%, reacting at 50-55°C for 4-6 hours, filtering, and washing to obtain a silane-modified mixed filler;

[0036] (3) A silane-modified mixed filler and N,N-dimethylformamide, N-(4-anilinophenyl)maleimide and triethylamine in a mass ratio of (2-4):(10-14):80:(0.4-0.7) were heated to 55-60°C and reacted for 20-24 hours. The mixture was filtered, washed and dried to obtain a modified mixed filler.

[0037] Furthermore, the mass ratio of nano-silicon dioxide, nano-lanthanum oxide, and nano-aluminum oxide is 1: (1.3-1.6): (0.5-0.8).

[0038] Furthermore, the nano-silicon dioxide has an average particle size of 20 nm and a specific surface area of ​​180 ± 50 m 2 / g.

[0039] Furthermore, the particle size of nano-lanthanum oxide is 30nm-50nm, and the specific surface area is 30-50m 2 / g.

[0040] Furthermore, the average particle size of nano-alumina is 0.3 μm and the specific surface area is 5-10 m 2 / g.

[0041] The bending resistance of coating after long-chain olefin modified dicyclopentadiene resin and polyaspartic acid ester resin, modified polyaspartic acid ester resin compounding is not good. Although high cross-linking density may improve the hardness and chemical resistance of coating, it can also reduce its pliability simultaneously. The addition of long-chain olefin modified dicyclopentadiene resin causes the degree of freedom between molecules to reduce, thereby making coating become more brittle, and bending resistance declines. The present invention can improve the bending resistance of coating by adding modified mixed filler in coating. Modified mixed filler can disperse stress concentration points. When coating is subjected to bending force, the matrix material around the filler particles can disperse stress, reduce the crack formation caused by excessive local stress, and filler can form microcracks or spaces in matrix after modification, form "crack bridging", and can effectively delay the expansion of cracks. The surface treatment of modified mixed filler often can improve its compatibility with resin matrix, reduce interfacial stress, ensure that good combination is arranged between filler and matrix, and good interface bonding can prevent filler from separating from matrix when bending, thereby maintaining the integrity of coating. When nano-silica, nano-lanthanum oxide, and nano-aluminum oxide have a specific particle size and specific surface area, the wear resistance of the coating can be improved.

[0042] N-(4-anilinophenyl)maleimide, CAS number: 32099-65-3.

[0043] Furthermore, the adhesion promoter is German Walker VOK®_SILQUESTVOKA-2120 aminosilane.

[0044] The present invention provides an application of a method for preparing an environmentally friendly coating using a modified polyaspartic acid ester resin and isocyanate, wherein the volume ratio of the components A and B is 1:1, and the coating is used for corrosion protection of plastic material structures in the offshore petrochemical industry.

[0045] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0046] 1. The present invention can improve the salt spray resistance of the coating by compounding the polyaspartic acid ester resin with the modified polyaspartic acid ester resin.

[0047] 2. The present invention further adds long-chain olefin-modified dicyclopentadiene resin to improve the chemical resistance of the coating.

[0048] 3. The present invention can improve the bending resistance of the coating by adding a modified mixed filler into the coating.

[0049] 4. When nano-silica, nano-lanthanum oxide, and nano-alumina have specific particle sizes and specific surface areas, they can improve the wear resistance of coatings. DETAILED DESCRIPTION

[0050] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0051] Some of the raw materials in the present invention are:

[0052] The leveling agent is Digao TWIN-4100 leveling agent.

[0053] The defoaming agent is TEGO901W defoaming agent.

[0054] Example 1

[0055] This embodiment provides a method for preparing an environmentally friendly coating by using a modified polyaspartic acid ester resin and an isocyanate, comprising the following steps:

[0056] (1) Weigh the following raw materials in parts by mass:

[0057] Component A: 24 parts of modified polyaspartic acid ester resin, 9 parts of polyaspartic acid ester resin, 15 parts of long-chain olefin modified dicyclopentadiene resin, 3 parts of zinc phosphate, 2 parts of dispersant, 4 parts of adhesion promoter, 16 parts of modified mixed filler;

[0058] Component B: 77 parts of toluene diisocyanate, 25 parts of HDI trimer, 4 parts of defoamer, 2 parts of leveling agent;

[0059] (2) Modified polyaspartic acid ester resin, long-chain olefin modified dicyclopentadiene resin, polyaspartic acid ester resin, zinc phosphate, modified mixed filler, dispersant and adhesion promoter were mixed, heated to 47°C, rotated at 3500 rpm, and stirred for 25 minutes to obtain component A;

[0060] (3) Toluene diisocyanate, HDI trimer, defoamer and leveling agent were mixed at a speed of 2200 rpm and stirred for 15 minutes to obtain component B.

[0061] The polyaspartic acid ester resin has an NH equivalent weight of 1140 g / mol and was purchased from Zhuhai Feiyang Chemical Co., Ltd. under the model number of aspartic acid polyurea resin D2925.

[0062] HDI trimer, Wuhan Huaxiang Kejie Biotechnology Co., Ltd., hexamethylene diisocyanate-based polyisocyanate, model HT-100.

[0063] The preparation method of long-chain olefin-modified dicyclopentadiene resin comprises the following steps:

[0064] S1: Dicyclopentadiene, 1-dodecene, and toluene were added to a stainless steel hot polymerization reactor. After nitrogen displacement to remove air from the reactor, the reactor was pressurized to 0.6 MPa and reacted at 182°C for 7 hours. After cooling to room temperature, unreacted olefins and toluene were removed by vacuum distillation to obtain a long-chain olefin-modified dicyclopentadiene hot polymerization resin.

[0065] S2: Long-chain olefin-modified dicyclopentadiene thermal polymer resin, toluene and nickel-supported catalyst in a mass ratio of 100:130:1 are added to a stainless steel reactor, and the air is removed by multiple replacements with hydrogen. After heating to 162°C, hydrogen is introduced to increase the pressure to 1.4 MPa. After hydrogenation for 4.5 hours, the reactor is cooled and depressurized, and the toluene is removed by vacuum distillation to obtain a long-chain olefin-modified dicyclopentadiene resin.

[0066] The mass ratio of dicyclopentadiene:1-dodecene:toluene is 8:3:10.

[0067] Dicyclopentadiene with a purity of 90% was purchased from Shandong Maojun Chemical.

[0068] The nickel-supported catalyst was purchased from Shanghai Xunkai New Material Technology Co., Ltd., model number SNCAT-8800P.

[0069] The preparation method of modified polyaspartic acid ester resin is:

[0070] (1) 12 parts by mass of silica sol and 3 parts by mass of N-[3-(trimethoxysilyl)propyl]ethylenediamine were mixed, stirred and reacted at 65°C for 28 hours, 1.4 parts by mass of methyl methacrylate were added, stirred and reacted at 74°C for 28 hours, 1.1 parts by mass of ethylenediamine were added, stirred and reacted at 27°C for 28 hours to obtain amino-functionalized silica sol;

[0071] (2) Mixing amino-functionalized silica sol and hexamethylene diisocyanate, reacting at 82°C for 2.5 hours, cooling to 17°C, and adding hexamethylenediamine dropwise for end-capping to obtain amino-functionalized silica sol branched modified hexamethylenediamine reaction solution;

[0072] (3) Diethyl maleate was added dropwise to the reaction solution of amino-functionalized silica sol branched modified hexamethylenediamine. After the addition was completed, the temperature was raised to 104°C and the reaction was carried out at a constant temperature for 17 hours. Then, the unreacted raw materials were removed by vacuum rotary evaporation to obtain modified polyaspartic acid ester resin.

[0073] The mass fraction of silicon dioxide in the silica sol is 25-35%. Linyi Kehan ​​Silicon Products Co., Ltd. Model: KHZCM-30.

[0074] N-[3-(Trimethoxysilyl)propyl]ethylenediamine, CAS: 1760-24-3.

[0075] The mass ratio of silica sol to hexamethylene diisocyanate is 0.8:1.

[0076] The molar ratio of hexamethylenediamine to hexamethylene diisocyanate is 1.4:1.

[0077] The molar ratio of diethyl maleate to hexamethylenediamine is 1:2.7.

[0078] The preparation method of the modified mixed filler is:

[0079] (1) Mixing nano-silicon dioxide, nano-lanthanum oxide, and nano-aluminum oxide to obtain a mixed filler;

[0080] (2) Mixing a mixed filler, a silane coupling agent KH560, and an ethanol aqueous solution with a mass ratio of 1:0.15:9, reacting at 52°C for 5 h, filtering, and washing to obtain a silane-modified mixed filler;

[0081] (3) A silane-modified mixed filler and N,N-dimethylformamide, N-(4-anilinophenyl)maleimide and triethylamine in a mass ratio of 3:12:80:0.5 were heated to 57°C and reacted for 22 hours. The mixture was filtered, washed and dried to obtain a modified mixed filler.

[0082] The mass ratio of nano-silicon dioxide, nano-lanthanum oxide and nano-aluminum oxide is 1:1.5:0.7.

[0083] The average particle size of nano-silicon dioxide is 20nm, and the specific surface area is 180±50m 2 / g.

[0084] The particle size of nano-lanthanum oxide is 30nm-50nm, and the specific surface area is 30-50m 2 / g.

[0085] The average particle size of nano-alumina is 0.3 μm and the specific surface area is 5-10 m 2 / g.

[0086] N-(4-anilinophenyl)maleimide, CAS number: 32099-65-3.

[0087] The adhesion promoter is German Walker VOK®_SILQUESTVOKA-2120 aminosilane.

[0088] Example 2

[0089] This embodiment provides a method for preparing an environmentally friendly coating by using a modified polyaspartic acid ester resin and an isocyanate, comprising the following steps:

[0090] (1) Weigh the following raw materials in parts by mass:

[0091] Component A: 22 parts of modified polyaspartic acid ester resin, 11 parts of polyaspartic acid ester resin, 13 parts of long-chain olefin modified dicyclopentadiene resin, 5 parts of zinc phosphate, 1 part of dispersant, 5 parts of adhesion promoter, 12 parts of modified mixed filler;

[0092] Component B: 80 parts of toluene diisocyanate, 20 parts of HDI trimer, 5 parts of defoamer, and 2 parts of leveling agent;

[0093] (2) Mixing the modified polyaspartic acid ester resin, the long-chain olefin-modified dicyclopentadiene resin, the polyaspartic acid ester resin, the zinc phosphate, the modified mixed filler, the dispersant and the adhesion promoter, heating to 50° C., rotating at 4000 rpm, and stirring for 20 minutes to obtain component A;

[0094] (3) Toluene diisocyanate, HDI trimer, defoamer and leveling agent were mixed and stirred at a speed of 2500 rpm for 10 minutes to obtain component B.

[0095] The polyaspartic acid ester resin has an NH equivalent weight of 1140 g / mol and was purchased from Zhuhai Feiyang Chemical Co., Ltd. under the model number of aspartic acid polyurea resin D2925.

[0096] HDI trimer, Wuhan Huaxiang Kejie Biotechnology Co., Ltd., hexamethylene diisocyanate-based polyisocyanate, model HT-100.

[0097] The preparation method of long-chain olefin-modified dicyclopentadiene resin comprises the following steps:

[0098] S1: Dicyclopentadiene, 1-dodecene, and toluene were added to a stainless steel hot polymerization reactor. After nitrogen displacement to remove air from the reactor, the reactor was pressurized to 0.8 MPa and reacted at 180°C for 8 hours. After cooling to room temperature, unreacted olefins and toluene were removed by vacuum distillation to obtain a long-chain olefin-modified dicyclopentadiene hot polymerization resin.

[0099] S2: Add long-chain olefin-modified dicyclopentadiene thermal polymer resin, toluene and nickel-supported catalyst in a mass ratio of 100:120:1 into a stainless steel reactor, use hydrogen to replace the air multiple times, raise the temperature to 165°C, introduce hydrogen to increase the pressure to 1.3 MPa, hydrogenate for 5 hours, cool and release the pressure, remove toluene by reduced pressure distillation, and obtain long-chain olefin-modified dicyclopentadiene resin.

[0100] The mass ratio of dicyclopentadiene:1-dodecene:toluene is 7:3:10.

[0101] Dicyclopentadiene with a purity of 90% was purchased from Shandong Maojun Chemical.

[0102] The nickel-supported catalyst was purchased from Shanghai Xunkai New Material Technology Co., Ltd., model number SNCAT-8800P.

[0103] The preparation method of modified polyaspartic acid ester resin is:

[0104] (1) 12 parts by mass of silica sol and 2.8 parts by mass of N-[3-(trimethoxysilyl)propyl]ethylenediamine were mixed, stirred and reacted at 68°C for 26 hours, 1.5 parts by mass of methyl methacrylate were added, stirred and reacted at 72°C for 30 hours, 1 part by mass of ethylenediamine was added, stirred and reacted at 30°C for 26 hours to obtain amino-functionalized silica sol;

[0105] (2) Mixing amino-functionalized silica sol and hexamethylene diisocyanate, reacting at 85°C for 3 hours, cooling to 15°C, and adding hexamethylenediamine dropwise for end-capping to obtain amino-functionalized silica sol branched modified hexamethylenediamine reaction solution;

[0106] (3) Diethyl maleate was added dropwise to the reaction solution of amino-functionalized silica sol branched modified hexamethylenediamine. After the addition was completed, the temperature was raised to 105°C and the reaction was carried out at a constant temperature for 15 hours. Then, the unreacted raw materials were removed by vacuum rotary evaporation to obtain modified polyaspartic acid ester resin.

[0107] The mass fraction of silicon dioxide in the silica sol is 25-35%. Linyi Kehan ​​Silicon Products Co., Ltd. Model: KHZCM-30.

[0108] N-[3-(Trimethoxysilyl)propyl]ethylenediamine, CAS: 1760-24-3.

[0109] The mass ratio of silica sol to hexamethylene diisocyanate is 0.82:1.

[0110] The molar ratio of hexamethylenediamine to hexamethylene diisocyanate is 1.2:1.

[0111] The molar ratio of diethyl maleate to hexamethylenediamine is 1:2.8.

[0112] The preparation method of the modified mixed filler is:

[0113] (1) Mixing nano-silicon dioxide, nano-lanthanum oxide, and nano-aluminum oxide to obtain a mixed filler;

[0114] (2) Mixing a mixed filler, a silane coupling agent KH560, and a 60% ethanol aqueous solution in a mass ratio of 1:0.1:10, reacting at 55°C for 4 hours, filtering, and washing to obtain a silane-modified mixed filler;

[0115] (3) A silane-modified mixed filler and N,N-dimethylformamide, N-(4-anilinophenyl)maleimide and triethylamine in a mass ratio of 4:10:80:0.7 were heated to 60°C and reacted for 20 hours. The mixture was filtered, washed and dried to obtain a modified mixed filler.

[0116] The mass ratio of nano-silicon dioxide, nano-lanthanum oxide and nano-aluminum oxide is 1:1.6:0.8.

[0117] The average particle size of nano-silicon dioxide is 20nm, and the specific surface area is 180±50m 2 / g.

[0118] The particle size of nano-lanthanum oxide is 30nm-50nm, and the specific surface area is 30-50m 2 / g.

[0119] The average particle size of nano-alumina is 0.3 μm and the specific surface area is 5-10 m 2 / g.

[0120] N-(4-anilinophenyl)maleimide, CAS number: 32099-65-3.

[0121] The adhesion promoter is German Walker VOK®_SILQUESTVOKA-2120 aminosilane.

[0122] Comparative Example 1

[0123] The difference between this comparative example and Example 1 is that: 24 parts of modified polyaspartic acid ester resin, 9 parts of polyaspartic acid ester resin, and 15 parts of long-chain olefin-modified dicyclopentadiene resin are replaced by: 19 parts of modified polyaspartic acid ester resin, 2 parts of polyaspartic acid ester resin, and 9 parts of long-chain olefin-modified dicyclopentadiene resin.

[0124] Comparative Example 2

[0125] The difference between this comparative example and Example 1 is that the preparation method of the modified polyaspartic acid ester resin is:

[0126] (1) In a nitrogen-protected reactor, add a 20% trichlorosilane ethanol solution, add deionized water dropwise under stirring, the molar ratio of deionized water to trichlorosilane is 1:3, react at a temperature of 75°C for 0.5 hour, then add hexamethylene diisocyanate, and continue to react for 0.5 hour to obtain a pre-reaction solution; the mass ratio of trichlorosilane to hexamethylene diisocyanate is 0.8:1;

[0127] (2) The temperature of the reactor was controlled within the range of 15°C by water cooling, and hexamethylenediamine was added dropwise to the above-mentioned pre-reaction solution under stirring to obtain a silicon-blocked branched modified organic diamine reaction solution; the molar ratio of hexamethylenediamine to hexamethylene diisocyanate was 1.4:1;

[0128] (3) Slowly add dimethyl maleate dropwise to the above silicon block branched modified organic diamine reaction solution using a titration funnel. The molar ratio of diethyl maleate to hexamethylenediamine is 1:2.7. After the addition is complete, the temperature is raised to 90°C and the reaction is carried out at a constant temperature for 10 hours. Then, the solvent is removed to obtain a modified polyaspartic acid ester resin.

[0129] Comparative Example 3

[0130] The difference between this comparative example and Example 1 is that the mass ratio of nano-silicon dioxide, nano-lanthanum oxide and nano-aluminum oxide is 1:1:1.

[0131] Comparative Example 4

[0132] The difference between this comparative example and Example 1 is that the average particle size of the nano-silicon dioxide is 80 nm, and the specific surface area is 60 ± 20 m 2 / g. The particle size of nano-lanthanum oxide is 1μm-5μm, and the specific surface area is 1-10m 2 / g. The average particle size of nano-alumina is 10μm and the specific surface area is 1-5m 2 / g.

[0133] Comparative Example 5

[0134] The difference between this comparative example and Example 1 is that 24 parts of modified polyaspartic acid ester resin, 9 parts of polyaspartic acid ester resin, and 15 parts of long-chain olefin-modified dicyclopentadiene resin are replaced by 24 parts of modified polyaspartic acid ester resin and 24 parts of polyaspartic acid ester resin.

[0135] Comparative Example 6

[0136] The difference between this comparative example and Example 1 is that the polyaspartic acid ester resin has an NH equivalent of 230 g / mol and is purchased from Zhuhai Feiyang Chemical Co., Ltd., and the model is aspartic acid polyurea resin F220.

[0137] Comparative Example 7

[0138] The difference between this comparative example and Example 1 is that the mass ratio of dicyclopentadiene:1-dodecene:toluene is 5:4:10.

[0139] Performance Testing

[0140] 1. Refer to GB / T5210-2006 to determine the adhesion of coatings on PET plastic surfaces;

[0141] 2. Refer to GB / T1771-2007 to measure the salt spray resistance of the coating for 4200h. If there is no blistering, rusting, cracking or falling off, it is considered as conforming; otherwise, it is considered as non-conforming.

[0142] 3. Refer to GB / T9274-1988 to test the coating's resistance to chemical media (room temperature for 720 hours): 10wt% sodium hydroxide, 10wt% sulfuric acid. If there is no peeling, wrinkling, cracking, blistering, or rusting, it is considered as conforming; otherwise, it is considered as non-conforming.

[0143] 4. Determine the abrasion resistance of the coating (1000g / 1000r.CS-10) according to GB / T1768-2006;

[0144] 5. Refer to Appendix D of SY / T0315 to determine the coating's bending resistance (-20°C, 1.5°).

[0145] 6. Refer to GB / T1766-2008 to determine the UV aging resistance of the coating (UVB-313 Lamp. 1440h). If there is no blistering, rusting, cracking, or peeling, and the color change is level 0, the gloss loss is level 1, and the powdering is level 0, it is recorded as compliance; otherwise, it is recorded as non-compliance.

[0146] Table 1 Performance test results

[0147]

[0148] From the above performance test results, it can be seen that Examples 1-2 have excellent comprehensive performance, especially Example 1 has the most outstanding comprehensive performance. This is mainly because the synergistic effect of multiple components improves the comprehensive performance of the coating.

[0149] The comparative examples, however, did not adopt the necessary technical solutions, resulting in significantly worse performance tests than the examples. In comparative example 1, the ratio of modified polyaspartic acid ester resin, polyaspartic acid ester resin, and long-chain olefin-modified dicyclopentadiene resin was changed, and it can be seen that the corrosion resistance decreased, proving that the three resin compounding scheme has an important influence on the corrosion resistance of the coating. In comparative example 2, the preparation method of the modified polyaspartic acid ester resin is different, and the salt spray resistance decreases, indicating that only the polyaspartic acid ester resin prepared by the present invention and the modified polyaspartic acid ester resin are compounded to improve the salt spray resistance of the coating. Comparative examples 3-4 have different preparation conditions for the modified mixed fillers, and the results show that this affects the bending resistance and wear resistance of the coating. The above experimental results further prove the importance of the technical solution defined in the present invention for its technical effects. In Comparative Example 5, the modified polyaspartic acid ester resin, polyaspartic acid ester resin, and long-chain olefin-modified dicyclopentadiene resin were varied in their ratios, resulting in decreased adhesion, chemical resistance, and salt spray resistance. This suggests that the ratio of these three components significantly impacts the coating's performance. Comparative Example 6 employed polyaspartic acid ester resins with varying NH equivalents, and Comparative Example 7 employed different mass ratios of dicyclopentadiene:1-dodecene:toluene in the preparation of the long-chain olefin-modified dicyclopentadiene resin, all of which impacted the coating's performance.

[0150] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing an environmentally friendly coating using a modified polyaspartic acid ester resin and an isocyanate, characterized in that: The following steps are involved: (1) Weigh the following raw materials in parts by mass: Component A: 22-27 parts of modified polyaspartic acid ester resin 1, 6-11 parts of polyaspartic acid ester resin 2, 13-18 parts of long-chain olefin-modified dicyclopentadiene resin, 2-5 parts of zinc phosphate, 1-3 parts of dispersant, 2-5 parts of adhesion promoter, and 12-18 parts of modified mixed filler. The NH equivalent weight of polyaspartic acid ester resin 2 is 1140 g / mol. Preparation method of long-chain olefin-modified dicyclopentadiene resin, The following steps are involved: S1: Add dicyclopentadiene, 1-dodecene, and toluene in a mass ratio of (7-9): (1-3): 10 to a stainless steel hot polymerization kettle, replace the air in the reactor with nitrogen, pressurize to 0.5-0.8 MPa, and react at a temperature of 180-185°C for 6-8 hours; after cooling to room temperature, remove unreacted olefins and toluene by vacuum distillation to obtain a long-chain olefin-modified dicyclopentadiene hot polymerization resin; S2: Add a long-chain olefin-modified dicyclopentadiene hot polymerization resin, toluene, and a nickel-supported catalyst in a mass ratio of 100: (120-140): 1 to a stainless steel reactor, replace the air with hydrogen several times, heat to 160-165°C, introduce hydrogen to increase the pressure to 1.3-1.5 MPa, hydrogenate for 4-5 hours, cool and release the pressure, remove toluene by vacuum distillation, and obtain a long-chain olefin-modified dicyclopentadiene resin; Component B: 75-80 parts of toluene diisocyanate, 20-30 parts of HDI trimer, 3-5 parts of defoamer, 2-3 parts of leveling agent; (2) Mixing the modified polyaspartic acid ester resin 1, the long-chain olefin-modified dicyclopentadiene resin, the polyaspartic acid ester resin 2, zinc phosphate, the modified mixed filler, the dispersant and the adhesion promoter, heating to 45-50° C., rotating at 3000-4000 rpm, and stirring for 20-30 minutes to obtain component A; (3) Mix toluene diisocyanate, HDI trimer, defoamer and leveling agent, stir at a speed of 2000-2500 rpm for 10-20 minutes to obtain component B; The preparation method of the modified mixed filler is as follows: a1, mixing nano-silicon dioxide, nano-lanthanum oxide, and nano-aluminum oxide in a mass ratio of 1: (1.3-1.6): (0.5-0.8) to obtain a mixed filler; a2, mixing the mixed filler, a silane coupling agent KH560, and a 60-70% by mass ethanol aqueous solution in a mass ratio of 1: (0.1-0.2): (8-10), reacting at 50-55° C. for 4-6 hours, filtering, washing, A silane-modified mixed filler is obtained; a3. A silane-modified mixed filler and N,N-dimethylformamide, N-(4-anilinophenyl)maleimide and triethylamine in a mass ratio of (2-4): (10-14): 80: (0.4-0.7) are heated to 55-60°C for reaction for 20-24 hours, filtered, washed and dried to obtain a modified mixed filler; the nano-silica has an average particle size of 20 nm and a specific surface area of ​​180±50 m 2 / g; the particle size of the nano lanthanum oxide is 30nm-50nm, and the specific surface area is 30-50m 2 / g; the average particle size of the nano-alumina is 0.3μm and the specific surface area is 5-10m 2 / g; The preparation method of the modified polyaspartic acid ester resin 1 is as follows: b1, 12 parts by mass of silica sol and 2.8-3.3 parts by mass of N-[3-(trimethoxysilyl)propyl]ethylenediamine are mixed, and the mixture is stirred at 64-68°C for 26-30 hours, 1.3-1.5 parts by mass of methyl methacrylate are added, and the mixture is stirred at 72-76°C for 26-30 hours, and 1-1.2 parts by mass of ethylenediamine are added, and the mixture is stirred at 25-30°C for 26-30 hours to obtain amino-functionalized silica sol; b2, the amino-functionalized silica sol is mixed. b. Add diethyl maleate dropwise to the amino-functionalized silica sol-branched modified hexamethylenediamine reaction solution. After the addition is complete, heat the mixture to 102-105° C. and react at a constant temperature for 15-20 hours. Then, remove the unreacted raw materials by rotary evaporation under reduced pressure to obtain a modified polyaspartic acid resin 1.

2. The use of the environmentally friendly coating prepared by the method for preparing an environmentally friendly coating using a modified polyaspartic acid ester resin and an isocyanate according to claim 1, characterized in that: The volume ratio of component A to component B is 1:1, and the product is used for corrosion protection of plastic structures in the offshore petrochemical industry.

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