A solvent-free epoxy glass flake coating and a preparation process thereof

Abstract

This application discloses a solvent-free epoxy glass flake coating and its preparation process, relating to the field of coating technology. Component A comprises 30-50% polyether-modified epoxy resin, 5-15% reactive diluent, 0.5-2% dispersant, 3-5% toughening agent, 4-8% modified macroporous silica, 15-25% glass flakes, 3-5% graphene, 8-15% anti-rust pigment, 0.1-1% ultraviolet absorber, 0.5-1.5% thixotropic agent, 0.8-1.5% leveling agent, and 0.1-1% defoamer; Component B comprises 60-80% epoxy resin curing agent, 9.5-18% modified macroporous silica, 10-20% graphene, and 0.5-2% dispersant; Component A and Component B are mixed at a mass ratio of 1:0.18-0.26 during use. The solvent-free epoxy glass flake coating provided in this application has strong adhesion and abrasion resistance.

Description

Technical Field

[0001] This application relates to the field of coating technology, and in particular to a solvent-free epoxy glass flake coating and its preparation process. Background Technology

[0002] Metal corrosion is prevalent in all sectors of human production, causing huge losses to the national economy. Applying anti-corrosion coatings is efficient, simple, and low-cost, making it the most widely used anti-corrosion measure. With the increasing demands for anti-corrosion coatings in the anti-corrosion industry, epoxy glass flake coatings, with their excellent shielding properties, are widely used in harsh corrosive environments such as marine and petrochemical anti-corrosion. Currently, the mainstream epoxy glass flake coatings are solvent-based and solvent-free. Solvent-based coatings require the addition of large amounts of volatile organic solvents, such as benzene or alcohols, in their formulations; these solvents evaporate during application, posing a threat to the environment and human health. Solvent-free coatings do not contain volatile organic solvents, resulting in less environmental pollution and allowing for higher thickness in a single application, significantly improving application efficiency. Therefore, solvent-free epoxy glass flake coatings, due to their environmental friendliness and high efficiency, are gradually becoming the mainstream choice in the anti-corrosion field.

[0003] Solvent-free epoxy glass flake coatings primarily use reactive diluents to dissolve epoxy resin as the main film-forming agent. However, epoxy resin itself is a brittle material. While the cured coating exhibits high hardness and strength, it lacks flexibility, making it prone to cracking under impact and leading to corrosion failure. This brittleness is particularly pronounced in dynamic environments such as offshore platforms and ships. Ordinary epoxy resins also have poor compatibility and insufficient bonding with fillers like glass flakes, easily agglomerating in the coating and causing defects and voids, affecting its uniformity and shielding performance. Summary of the Invention

[0004] To address the issues of brittleness and compatibility in solvent-free epoxy glass flake coatings, this application provides a solvent-free epoxy glass flake coating and its preparation process.

[0005] This application provides a solvent-free epoxy glass flake coating, which adopts the following technical solution:

[0006] A solvent-free epoxy glass flake coating comprises component A and component B. Component A, by weight percentage, includes: 30-50% polyether-modified epoxy resin, 5-15% reactive diluent, 0.5-2% dispersant, 3-5% toughening agent, 4-8% modified macroporous silica, 15-25% glass flakes, 3-5% graphene, 8-15% anti-rust pigment, 0.1-1% UV absorber, 0.5-1.5% thixotropic agent, 0.8-1.5% leveling agent, and 0.1-1% defoamer. Component B, by weight percentage, includes: 60-80% epoxy resin curing agent, 9.5-18% modified macroporous silica, 10-20% graphene, and 0.5-2% dispersant.

[0007] When using, component A and component B should be mixed evenly at a mass ratio of 1:0.18-0.26;

[0008] The toughening agent is polypropylene glycol dicyclohexyl ester.

[0009] Preferably, the polyether-modified epoxy resin is prepared from the following raw materials in parts by weight: 35-70 parts of bisphenol A type epoxy resin, 22-33 parts of isophorone diisocyanate, 0.18-0.3 parts of dibutyltin dilaurate, and 40-60 parts of polypropylene glycol.

[0010] Preferably, the preparation method of the polyether-modified epoxy resin includes the following steps:

[0011] After vacuum drying 35-70 parts of bisphenol A type epoxy resin at 60-70℃ for 2-4 hours, it is mixed with 22-33 parts of isophorone diisocyanate and heated to 70-80℃. Then, 0.12-0.2 parts of dibutyltin dilaurate are added, and the reaction is carried out for 3-5 hours. Subsequently, 40-60 parts of polypropylene glycol are added, the temperature is raised to 80-90℃, and then 0.06-0.1 parts of dibutyltin dilaurate are added, and the reaction is carried out for 4-6 hours. After the reaction is completed, the product is degassed to obtain polyether modified epoxy resin.

[0012] Preferably, the polypropylene glycol dicyclohexane ester is prepared from the following raw materials in parts by weight: 17-25 parts cyclohexane, 22-33 parts polypropylene glycol, 50-100 parts cyclohexane, and 0.78-1.16 parts p-toluenesulfonic acid.

[0013] Preferably, the method for preparing the polypropylene glycol dicyclohexyl ester includes the following steps:

[0014] Cyclohexane and polypropylene glycol were added to cyclohexane and stirred to dissolve. Then p-toluenesulfonic acid was added, and the mixture was gradually heated to 69-75℃ under stirring for 2-5 hours. After the reaction was completed, cyclohexane was removed by rotary evaporation. The product was washed several times to remove unreacted cyclohexane and p-toluenesulfonic acid. The product was then dried with anhydrous magnesium sulfate for 24-30 hours and filtered to obtain polypropylene glycol dicyclohexane ester.

[0015] Preferably, the modified macroporous silica is prepared from the following raw materials in parts by weight: 9.86-19.72 parts sodium silicate, 150-300 parts water, 0.003-0.006 parts cetyltrimethylammonium bromide, 4-6 parts hydroxyl silicone oil, 50-100 parts water glass, 25-45 parts dilute sulfuric acid, and 2-3 parts oxalic acid.

[0016] Preferably, the method for preparing the modified macroporous silica includes the following steps:

[0017] S1. Mix 9.86-19.72 parts of sodium silicate, 150-300 parts of water, 0.003-0.006 parts of hexadecyltrimethylammonium bromide, and 4-6 parts of hydroxyl silicone oil, and stir at 75-85℃ for 1-2 hours. During stirring, add 50-100 parts of water glass and 25-45 parts of dilute sulfuric acid dropwise. Then add 2-3 parts of oxalic acid and adjust the pH of the solution to 6-7, and keep warm for 2-3 hours. When the pH of the system is adjusted to 3-4, the reaction is stopped to obtain nano-silica hydrogel. Filter and wash the hydrogel to obtain nano-silica filter cake.

[0018] S2. The obtained nano-silica filter cake is diluted with water and emulsified at 1500-1700 rpm for 15-20 min; the emulsified slurry is spray-dried to obtain nano-silica powder; after pulverization, it is calcined at 300-500℃ to obtain modified macroporous silica.

[0019] Preferably, the conditions for the spray drying process are: induced draft frequency of 30-40Hz, feed rate of 15-20rpm, atomization pressure of 0.4-0.5MPa, inlet temperature of 200-220℃, and outlet temperature of 105-115℃.

[0020] Preferably, the ultraviolet absorber is one or a mixture of UV-531, UV-327, UV-1577, Tinuvin 400, and Tinuvin 1130.

[0021] This application provides a solvent-free epoxy glass flake coating preparation process, which adopts the following technical solution:

[0022] A process for preparing a solvent-free epoxy glass flake coating includes the following steps:

[0023] Preparation of Component A: Add polyether-modified epoxy resin, reactive diluent, and toughening agent to a stirred tank and stir evenly at 300-500 rpm; add dispersant and defoamer and stir evenly at 600-800 rpm; add modified macroporous silica, glass flakes, graphene, rust-preventive pigment, thixotropic agent, leveling agent, and ultraviolet absorber in sequence, and stir at 400-600 rpm for 10-20 min to obtain Component A;

[0024] Preparation of S2.B component: Add epoxy resin curing agent and dispersant to a stirred tank and stir evenly at 800-1000 rpm; then add modified macroporous silica and graphene in sequence and stir at 1300-1500 rpm for 20-40 min to obtain component B.

[0025] S3. Mix component A and component B at a mass ratio of 1:0.18-0.26.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. The polyether-modified epoxy resin provided in this application is formed by reacting isophorone diisocyanate with bisphenol A type epoxy resin under the catalysis of dibutyltin dilaurate to form a cross-linked structure; after the reaction is completed, polyether polyol and free -NCO groups are added to continue the reaction to form flexible segments. These flexible segments can significantly improve the flexibility, impact resistance and compatibility of epoxy resin.

[0028] 2. The toughening agent provided in this application uses polypropylene glycol to provide flexible polyether segments and cyclohexane carboxylic acid to provide sterically hindered groups, which are chemically linked to obtain polypropylene glycol dicyclohexane ester. This results in a toughening agent that contains both flexible polyether segments and has good compatibility with polyether-modified epoxy resin. Furthermore, the toughening agent has a certain degree of steric hindrance, which can reduce the migration of plasticizer from the matrix. Through the toughening effect of polyether-modified epoxy resin and polypropylene glycol dicyclohexane ester, the flexibility and impact resistance of the coating are significantly improved.

[0029] 3. The modified macroporous silica provided in this application, under spray drying conditions, uses water glass as the silicon source, sulfuric acid as the precipitant, and hydroxyl silicone oil as the hydrophobic modifier. By controlling the sol-gel process, the structure of the silica gel is regulated. After washing, drying, and heat treatment, macroporous silica with low apparent density, large pore volume, and low thermal conductivity is obtained. It has higher hardness and wear resistance, and can significantly improve the mechanical properties of the coating, enhance the scratch resistance and impact resistance of the coating. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the embodiments.

[0031] The chemical reagents used in the preparation examples, embodiments, and comparative examples provided in this invention are all commercially available products.

[0032] Preparation Example 1: Polyether-modified epoxy resin

[0033] Preparation Example 1.1

[0034] 35g of bisphenol A type epoxy resin was vacuum dried at 60℃ for 2h, then mixed with 22g of isophorone diisocyanate and heated to 70℃. 0.12g of dibutyltin dilaurate was added, and the mixture was reacted for 3h. Subsequently, 40g of polypropylene glycol PPG-400 was added, the temperature was raised to 80℃, and 0.06g of dibutyltin dilaurate was added, and the mixture was reacted for 4h. After the reaction was completed, the product was placed in a vacuum degassing machine and degassed at 60℃ and -0.095MPa for 30min to obtain polyether modified epoxy resin.

[0035] Preparation Example 1.2

[0036] 52.5g of bisphenol A epoxy resin was vacuum dried at 65℃ for 3 hours, then mixed with 27.5g of isophorone diisocyanate and heated to 75℃. 0.16g of dibutyltin dilaurate was added, and the mixture was reacted for 4 hours. Subsequently, 50g of polypropylene glycol PPG-400 was added, the temperature was raised to 85℃, and 0.08g of dibutyltin dilaurate was added, and the mixture was reacted for 5 hours. After the reaction was completed, the product was placed in a vacuum degassing machine and degassed at 65℃ and -0.095MPa for 40 minutes to obtain polyether-modified epoxy resin.

[0037] Preparation Example 1.3

[0038] 70g of bisphenol A epoxy resin was vacuum dried at 70℃ for 4h, then mixed with 33g of isophorone diisocyanate and heated to 80℃. 0.2g of dibutyltin dilaurate was added, and the mixture was reacted for 5h. Subsequently, 60g of polypropylene glycol PPG-400 was added, the temperature was raised to 90℃, and 0.1g of dibutyltin dilaurate was added, and the mixture was reacted for 6h. After the reaction was completed, the product was placed in a vacuum degassing machine and degassed at 70℃ and -0.095MPa for 50min to obtain polyether modified epoxy resin.

[0039] Preparation Example 2: Preparation of Propylene Glycol Dicyclohexyl Carboxylate

[0040] Preparation Example 2.1

[0041] 17g of cyclohexane and 22g of polypropylene glycol PPG-400 were added to 50g of cyclohexane and stirred to dissolve. Then, 0.78g of p-toluenesulfonic acid was added, and the mixture was gradually heated to 69℃ and reacted for 2 hours under stirring. After the reaction was completed, the cyclohexane was removed by rotary evaporation. The product was washed several times with saturated sodium carbonate solution to remove unreacted cyclohexane and p-toluenesulfonic acid. After drying with anhydrous magnesium sulfate for 24 hours, the product was filtered to obtain polypropylene glycol dicyclohexane ester.

[0042] Preparation Example 2.2

[0043] 21g of cyclohexane and 27.5g of polypropylene glycol PPG-400 were added to 75g of cyclohexane and stirred to dissolve. Then, 0.97g of p-toluenesulfonic acid was added, and the mixture was gradually heated to 72℃ and reacted for 3.5h under stirring. After the reaction was completed, the cyclohexane was removed by rotary evaporation. The product was washed several times with saturated sodium carbonate solution to remove unreacted cyclohexane and p-toluenesulfonic acid. After drying with anhydrous magnesium sulfate for 27h, the product was filtered to obtain polypropylene glycol dicyclohexane ester.

[0044] Preparation Example 2.3

[0045] 25g of cyclohexane and 33g of polypropylene glycol PPG-400 were added to 100g of cyclohexane and stirred to dissolve. Then, 1.16g of p-toluenesulfonic acid was added, and the mixture was gradually heated to 75℃ and reacted for 5 hours under stirring. After the reaction was completed, the cyclohexane was removed by rotary evaporation. The product was washed several times with saturated sodium carbonate solution to remove unreacted cyclohexane and p-toluenesulfonic acid. After drying with anhydrous magnesium sulfate for 30 hours, the product was filtered to obtain polypropylene glycol dicyclohexane ester.

[0046] Preparation Example 3: Preparation of Modified Macroporous Accommodating Silica

[0047] Preparation Example 3.1

[0048] S1. Mix 9.86g sodium silicate, 150g pure water, 0.003g hexadecyltrimethylammonium bromide, and 4g hydroxyl silicone oil, and stir at 75℃ for 1h. During stirring, add 50g water glass and 25g 20% ​​sulfuric acid dropwise. Then add 2g oxalic acid and adjust the pH of the solution to 7 with 20% sulfuric acid. Keep warm for 2h. Then adjust the pH of the system to 4 with 20% sulfuric acid to stop the reaction and obtain nano-silica wet gel. Filter and wash it to obtain nano-silica filter cake.

[0049] S2. The obtained nano-silica filter cake is diluted with water and emulsified at 1500 rpm for 15 min on a high-speed shear emulsifier; the emulsified slurry is spray-dried by a spray dryer to obtain nano-silica powder; then it is pulverized by a flat mill air jet mill at 0.5 MPa and then calcined in a muffle furnace at 300℃ for 5 h to obtain modified macroporous silica; the spray drying conditions are: induced draft frequency 30 Hz, feed speed 15 rpm, atomization pressure 0.4 MPa, inlet temperature 200℃, and outlet temperature 105℃.

[0050] Preparation Example 3.2

[0051] S1. Mix 14.79g sodium silicate, 225g pure water, 0.0045g hexadecyltrimethylammonium bromide, and 5g hydroxyl silicone oil, and stir at 80℃ for 1.5h. During stirring, add 75g water glass and 35g 20% ​​sulfuric acid dropwise. Then add 2.5g oxalic acid and adjust the pH of the solution to 6.5 with 20% sulfuric acid. Keep warm for 2.5h. Then adjust the pH of the system to 3.5 with 20% sulfuric acid to stop the reaction and obtain nano-silica wet gel. Filter and wash the gel to obtain nano-silica filter cake.

[0052] S2. The obtained nano-silica filter cake was diluted with water and emulsified at 1600 rpm for 18 min on a high-speed shear emulsifier. The emulsified slurry was spray-dried to obtain nano-silica powder. Then, it was pulverized at 0.55 MPa by a flat mill air jet mill and calcined in a muffle furnace at 400℃ for 6 h to obtain modified macroporous silica. The spray drying conditions were: induced draft frequency 35 Hz, feed rate 18 rpm, atomization pressure 0.45 MPa, inlet temperature 210℃, and outlet temperature 110℃.

[0053] Preparation Example 3.3

[0054] S1. Mix 19.72g sodium silicate, 300g pure water, 0.006g hexadecyltrimethylammonium bromide, and 6g hydroxyl silicone oil, and stir at 85℃ for 2h. During stirring, add 100g water glass and 45g 20% ​​sulfuric acid dropwise. Then add 3g oxalic acid and adjust the pH of the solution to 6 with 20% sulfuric acid. Keep warm for 3h. Then adjust the pH of the system to 3 with 20% sulfuric acid to stop the reaction and obtain nano-silica wet gel. Filter and wash the gel to obtain nano-silica filter cake.

[0055] S2. The obtained nano-silica filter cake was diluted with water and emulsified at 1700 rpm for 20 min on a high-speed shear emulsifier. The emulsified slurry was spray-dried by a spray dryer to obtain nano-silica powder. Subsequently, it was pulverized by a flat mill air jet mill at 0.6 MPa and then calcined in a muffle furnace at 500℃ for 7 h to obtain modified macroporous silica. The spray drying conditions were: induced draft frequency 40 Hz, feed rate 20 rpm, atomization pressure 0.5 MPa, inlet temperature 220℃, and outlet temperature 115℃.

[0056] Example 1

[0057] Preparation of Component S1.A: 100g of polyether-modified epoxy resin prepared in Preparation Example 1.1, 5g of reactive diluent, and 5g of toughening agent polypropylene glycol dicyclohexyl ester prepared in Preparation Example 2.1 were added to a stirred tank and stirred at 300 rpm until homogeneous. 2g of dispersant and 1g of defoamer were added and stirred at 600 rpm until homogeneous. 8g of modified macroporous silica prepared in Preparation Example 3.1, 25g of glass flakes, 5g of graphene, 15g of rust-preventive pigment, 1.5g of thixotropic agent, 1.5g of leveling agent, and 1g of ultraviolet absorber were added sequentially and stirred at 400 rpm for 10 min to obtain Component A.

[0058] Preparation of S2.B component: 60g of epoxy resin curing agent and 2g of dispersant were added to the stirred tank per 100g and stirred evenly at 800rpm; then 18g of modified macroporous silica prepared in Preparation Example 3.1 and 20g of graphene were added in sequence and stirred at 1300rpm for 20min to obtain component B.

[0059] S3. Mix component A and component B at a mass ratio of 1:0.18 to obtain a solvent-free epoxy glass flake coating;

[0060] In this embodiment, the reactive diluent used is polypropylene glycol diglycidyl ether; the dispersant is BYK-163; the defoamer is polydimethylsiloxane; the anti-rust pigment is iron oxide red; the thixotropic agent is CF5415; the leveling agent is BZ610 leveling agent; the ultraviolet absorber is UV-531; and the epoxy resin curing agent is CK-5106 curing agent.

[0061] Example 2

[0062] Preparation of Component S1.A: 100g of polyether-modified epoxy resin prepared in Preparation Example 1.1, 10g of reactive diluent, and 4g of toughening agent polypropylene glycol dicyclohexyl ester prepared in Preparation Example 2.1 were added to a stirred tank and stirred at 400 rpm until homogeneous. 1g of dispersant and 0.5g of defoamer were added and stirred at 700 rpm until homogeneous. 6g of modified macroporous silica prepared in Preparation Example 3.1, 20g of glass flakes, 4g of graphene, 12g of rust-preventive pigment, 1g of thixotropic agent, 1g of leveling agent, and 0.5g of ultraviolet absorber were added sequentially and stirred at 500 rpm for 15 min to obtain Component A.

[0063] Preparation of component S2.B: 70g of epoxy resin curing agent and 1.2g of dispersant were added to a stirred tank per 100g and stirred evenly at 900rpm; then 13.8g of modified macroporous silica prepared in Preparation Example 3.1 and 15g of graphene were added sequentially and stirred at 1400rpm for 30min to obtain component B.

[0064] S3. Mix component A and component B at a mass ratio of 1:0.18 to obtain a solvent-free epoxy glass flake coating;

[0065] The reactive diluent used in this embodiment is polypropylene glycol diglycidyl ether; the dispersant is BYK-163; the defoamer is polydimethylsiloxane; the anti-rust pigment is iron oxide red; the thixotropic agent is CF5415; the leveling agent is BZ610 leveling agent; the ultraviolet absorber is Tinuvin 400; and the epoxy resin curing agent is CK-5106 curing agent.

[0066] Example 3

[0067] Preparation of Component S1.A: 100g of polyether-modified epoxy resin prepared in Preparation Example 1.1, 15g of reactive diluent, and 3g of toughening agent polypropylene glycol dicyclohexyl ester prepared in Preparation Example 2.1 were added to a stirred tank and stirred at 500 rpm until homogeneous. 0.5g of dispersant and 0.1g of defoamer were added and stirred at 800 rpm until homogeneous. 4g of modified macroporous silica prepared in Preparation Example 3.1, 15g of glass flakes, 3g of graphene, 8g of rust-preventive pigment, 0.5g of thixotropic agent, 0.8g of leveling agent, and 0.1g of ultraviolet absorber were added sequentially and stirred at 600 rpm for 210 min to obtain Component A.

[0068] Preparation of component S2.B: 80g of epoxy resin curing agent and 0.5g of dispersant were added to a stirred tank per 100g and stirred evenly at 1000rpm; then 9.5g of modified macroporous silica prepared in Preparation Example 3.1 and 10g of graphene were added sequentially and stirred at 1500rpm for 40min to obtain component B.

[0069] S3. Mix component A and component B at a mass ratio of 1:0.18 to obtain a solvent-free epoxy glass flake coating;

[0070] The reactive diluent used in this embodiment is polypropylene glycol diglycidyl ether; the dispersant is BYK-163; the defoamer is polydimethylsiloxane; the anti-rust pigment is iron oxide red; the thixotropic agent is CF5415; the leveling agent is BZ610 leveling agent; the ultraviolet absorber is UV-1577; and the epoxy resin curing agent is CK-5106 curing agent.

[0071] Example 4

[0072] The difference between Example 4 and Example 1 is that in Example 4, components A and B are mixed at a mass ratio of 1:0.22.

[0073] Example 5

[0074] The difference between Example 5 and Example 1 is that in Example 5, components A and B are mixed at a mass ratio of 1:0.26.

[0075] Example 6

[0076] The difference between Example 6 and Example 1 is that the polyether-modified epoxy resin used in Example 6 was prepared from Preparation Example 1.2.

[0077] Example 7

[0078] The difference between Example 7 and Example 1 is that the polyether-modified epoxy resin used in Example 7 was prepared from Preparation Example 1.3.

[0079] Example 8

[0080] The difference between Example 8 and Example 1 is that the polypropylene glycol dicyclohexyl ester used in Example 8 was prepared from Preparation Example 2.2.

[0081] Example 9

[0082] The difference between Example 9 and Example 1 is that the polypropylene glycol dicyclohexyl ester used in Example 9 was prepared from Preparation Example 2.3.

[0083] Example 10

[0084] The difference between Example 10 and Example 1 is that the modified macroporous silica used in Example 10 was prepared from Preparation Example 3.2.

[0085] Example 11

[0086] The difference between Example 11 and Example 1 is that the modified macroporous silica used in Example 10 was prepared from Preparation Example 3.3.

[0087] Comparative Example 1

[0088] The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, components A and B are mixed at a mass ratio of 1:0.14.

[0089] Comparative Example 2

[0090] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, components A and B are mixed at a mass ratio of 1:0.3.

[0091] Comparative Example 3

[0092] The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, an equal amount of unmodified bisphenol A type epoxy resin was used instead of polyether modified epoxy resin.

[0093] Comparative Example 4

[0094] The difference between Comparative Example 4 and Example 1 is that in Comparative Example 4, an equal amount of dibutyl phthalate was used instead of polypropylene glycol dicyclohexyl ester.

[0095] Comparative Example 5

[0096] The difference between Comparative Example 5 and Example 1 is that in Comparative Example 5, an equal amount of ordinary commercially available nano-silica was used instead of modified macroporous nano-silica.

[0097] Performance testing

[0098] The solvent-free epoxy glass flake coatings obtained in Examples 1-11 and Comparative Examples 1-5 were applied to the substrate thickness required by the test method using high-pressure airless spraying to prepare performance test boards. The boards were then cured in a standard environment of 23°C and 55% humidity for 7 days before various performance tests were conducted.

[0099] The adhesion of the solvent-free epoxy glass flake coatings obtained in Examples 1-11 and Comparative Examples 1-5 was tested according to ASTM D 4541-02, and the results are shown in Table 1.

[0100] II. The impact resistance of the solvent-free epoxy glass flake coatings obtained in Examples 1-11 and Comparative Examples 1-5 was tested with reference to SY / T 0040-2013. The results are shown in Table 1.

[0101] III. The abrasion resistance of the solvent-free epoxy glass flake coatings obtained in Examples 1-11 and Comparative Examples 1-5 was tested with reference to GB / T 1768-2006, and the results are shown in Table 1.

[0102] IV. Referring to GB / T 30648.1-2014, the solvent-free epoxy glass flake coatings obtained in Examples 1-11 and Comparative Examples 1-5 were immersed in seawater at 60°C for 90 days, and the changes in the coatings were observed.

[0103] The specific test results are as follows:

[0104] Table 1 Performance Test Results

[0105] Adhesion / MPa Impact resistance / J Abrasion resistance / mg (750g / 1000r) Seawater soaking Example 1 18.26 35 26 No change Example 2 19.32 38 22 No change Example 3 18.45 36 24 No change Example 4 19.86 40 21 No change Example 5 18.44 33 25 No change Example 6 18.54 37 24 No change Example 7 18.17 34 27 No change Example 8 19.01 39 23 No change Example 9 18.33 36 25 No change Example 10 19.14 38 24 No change Example 11 18.38 35 24 No change Comparative Example 1 11.45 21 90 No change Comparative Example 2 12.54 25 75 No change Comparative Example 3 9.41 15 99 Bubbling without cracking Comparative Example 4 13.68 19 64 Bubbling without cracking Comparative Example 5 10.89 18 81 Bubbling without cracking

[0106] As can be seen from the test results in Table 1, the solvent-free epoxy glass flake coating provided in this application has strong adhesion, good wear resistance, and good corrosion resistance. After being immersed in seawater at 60℃ for 90 days, the coating showed virtually no change.

[0107] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A solvent-free epoxy glass flake coating characterized by: The raw materials include component A and component B; component A, by weight percentage, comprises: 30-50% polyether-modified epoxy resin, 5-15% reactive diluent, 0.5-2% dispersant, 3-5% toughening agent, 4-8% modified macroporous silica, 15-25% glass flakes, 3-5% graphene, 8-15% rust-preventive pigment, 0.1-1% ultraviolet absorber, 0.5-1.5% thixotropic agent, 0.8-1.5% leveling agent, and 0.1-1% defoamer; component B, by weight percentage, comprises: 60-80% epoxy resin curing agent, 9.5-18% modified macroporous silica, 10-20% graphene, and 0.5-2% dispersant. When using, component A and component B should be mixed evenly at a mass ratio of 1:0.18-0.26; The toughening agent is polypropylene glycol dicyclohexyl ester; The method for preparing the modified macroporous silica includes the following steps: S1. By weight, mix 9.86-19.72 parts of sodium silicate, 150-300 parts of water, 0.003-0.006 parts of hexadecyltrimethylammonium bromide, and 4-6 parts of hydroxyl silicone oil, and stir at 75-85℃ for 1-2 hours. During stirring, add 50-100 parts of water glass and 25-45 parts of dilute sulfuric acid dropwise. Then add 2-3 parts of oxalic acid and adjust the pH of the solution to 6-7, and keep warm for 2-3 hours. When the pH of the system is adjusted to 3-4, the reaction is stopped to obtain nano-silica hydrogel. Filter and wash the hydrogel to obtain nano-silica filter cake. S2. The obtained nano-silica filter cake is diluted with water and emulsified at 1500-1700 rpm for 15-20 min; the emulsified slurry is spray-dried to obtain nano-silica powder; after pulverization, it is calcined at 300-500℃ to obtain modified macroporous nano-silica. The conditions for the spray drying process are: induced draft frequency 30-40Hz, feed rate 15-20rpm, atomization pressure 0.4-0.5MPa, inlet temperature 200-220℃, and outlet temperature 105-115℃.

2. A solvent-free epoxy glass flake coating according to claim 1, characterized in that: The polyether-modified epoxy resin is prepared from the following raw materials in parts by weight: 35-70 parts bisphenol A type epoxy resin, 22-33 parts isophorone diisocyanate, 0.18-0.3 parts dibutyltin dilaurate, and 40-60 parts polypropylene glycol.

3. A solvent-free epoxy glass flake coating according to claim 2, characterized in that: The preparation method of the polyether-modified epoxy resin includes the following steps: After vacuum drying 35-70 parts of bisphenol A type epoxy resin at 60-70℃ for 2-4 hours, it is mixed with 22-33 parts of isophorone diisocyanate and heated to 70-80℃. Then, 0.12-0.2 parts of dibutyltin dilaurate are added, and the reaction is carried out for 3-5 hours. Subsequently, 40-60 parts of polypropylene glycol are added, the temperature is raised to 80-90℃, and then 0.06-0.1 parts of dibutyltin dilaurate are added, and the reaction is carried out for 4-6 hours. After the reaction is completed, the product is degassed to obtain polyether modified epoxy resin.

4. The solvent-free epoxy glass flake coating according to claim 1, characterized in that: The polypropylene glycol dicyclohexane ester is prepared from the following raw materials in parts by weight: 17-25 parts cyclohexane, 22-33 parts polypropylene glycol, 50-100 parts cyclohexane, and 0.78-1.16 parts p-toluenesulfonic acid.

5. The solvent-free epoxy glass flake coating according to claim 4, characterized in that: The preparation method of the polypropylene glycol dicyclohexyl ester includes the following steps: Cyclohexane and polypropylene glycol were added to cyclohexane and stirred to dissolve. Then p-toluenesulfonic acid was added, and the mixture was gradually heated to 69-75℃ under stirring for 2-5 hours. After the reaction was completed, cyclohexane was removed by rotary evaporation. The product was washed several times to remove unreacted cyclohexane and p-toluenesulfonic acid. The product was then dried with anhydrous magnesium sulfate for 24-30 hours and filtered to obtain polypropylene glycol dicyclohexane ester.

6. The solvent-free epoxy glass flake coating according to claim 1, characterized in that: The ultraviolet absorber is one or a mixture of UV-531, UV-327, UV-1577, Tinuvin 400, and Tinuvin 1130.

7. The preparation process of a solvent-free epoxy glass flake coating according to any one of claims 1-6, characterized in that: Includes the following steps: Preparation of Component A: Add polyether-modified epoxy resin, reactive diluent, and toughening agent to a stirred tank and stir evenly at 300-500 rpm; add dispersant and defoamer and stir evenly at 600-800 rpm; add modified macroporous silica, glass flakes, graphene, rust-preventive pigment, thixotropic agent, leveling agent, and ultraviolet absorber in sequence, and stir at 400-600 rpm for 10-20 min to obtain Component A; Preparation of S2.B component: Add epoxy resin curing agent and dispersant to a stirred tank and stir evenly at 800-1000 rpm; then add modified macroporous silica and graphene in sequence and stir at 1300-1500 rpm for 20-40 min to obtain component B. S3. Mix component A and component B at a mass ratio of 1:0.18-0.26.