A high performance coil powder coating and a method for its preparation

Abstract

The application discloses a kind of high-performance coiled material powder coating and preparation method thereof, belong to powder coating technical field, the application is by the compounding of organosilicon modified epoxy resin and carboxyl-terminated polyester resin, after organosilicon modification, the segment of introduction-Si-O-Si in system has high flexibility, and synergistic effect with nano calcium carbonate, it is helpful to balance the adhesion and flexibility of coating, grafting modification graphene oxide, active chromium oxide is added again, can obviously improve the mechanical strength of coating;After then, phosphite group is grafted onto graphene oxide, and is applied in the present powder coating system, can form three-dimensional network structure in system, chemical bond effect, not only can improve its crosslinking stability in system, and the sheet structure of graphene oxide, also can play certain barrier property, can also give coating longer weather resistance, and active chromium oxide synergistic effect is further improved, and the weather resistance and corrosion resistance of coating.

Description

Technical Field

[0001] This invention relates to the field of powder coating technology, and more specifically, to a high-performance coil powder coating and its preparation method. Background Technology

[0002] Coil coating is a highly efficient continuous coating process widely used in construction, home appliances, furniture, and other fields. Traditional coil coatings are mostly solvent-based liquid coatings, which emit large amounts of volatile organic compounds (VOCs) during production and application, causing environmental pollution and posing fire hazards. With increasingly stringent global environmental regulations, developing environmentally friendly coil coating materials has become an important direction for the industry.

[0003] Powder coatings, as a type of solid coating with zero VOC emissions, offer advantages such as environmental friendliness, high efficiency, and high utilization rate, making them an ideal alternative to solvent-based coatings. However, the following problems arise when applying powder coatings to coil coating:

[0004] First, there's the challenge of balancing flexibility (T-bending performance) and hardness. Coil materials undergo rigorous rolling and bending during production, requiring coatings with excellent flexibility and adhesion—that is, good T-bending performance. However, to meet the scratch and wear resistance requirements of the finished product surface, the coating needs high hardness. In traditional powder coating formulations, increasing hardness often sacrifices flexibility, and vice versa, making it difficult to simultaneously meet these seemingly contradictory performance requirements.

[0005] Secondly, it is difficult to balance production efficiency and coating performance. For coil coating, due to cost considerations and the need to control the shape of the sheet, a uniform coating with certain performance is required. Traditional powder coatings have a wide particle size distribution, and under high production efficiency, defects such as poor leveling, orange peel, and exposed substrate are prone to occur during coating.

[0006] Third, insufficient adhesion. If the coating of a roll material used in outdoor environments has poor adhesion, it is prone to problems such as loss of gloss, chalking, and discoloration when exposed to outdoor environments for a long time, which affects its service life and appearance. Coating peeling points will accelerate corrosion and have poor weather resistance, thus affecting the service life of the roll material.

[0007] Therefore, there is an urgent need in this field to develop a new type of high-performance coil powder coating and its preparation method, which can simultaneously achieve excellent flexibility, high hardness, superior appearance and long-lasting weather resistance, so as to meet the stringent requirements of the modern coil coating industry for high efficiency, high performance and environmental protection. Summary of the Invention

[0008] In view of this, in order to solve one of the above-mentioned technical problems, the present invention provides a high-performance coil powder coating and its preparation method, the specific technical solution of which is as follows:

[0009] A high-performance coil coating powder, wherein the high-performance coil coating powder comprises the following raw materials in parts by weight:

[0010] The composition includes 20-40 parts of silicone-modified epoxy resin, 25-45 parts of carboxyl-terminated polyester resin, 3-7 parts of nano-calcium carbonate, 1-5 parts of grafted modified graphene oxide, 1-10 parts of active chromium oxide, 1-3 parts of polytetrafluoroethylene wax, 3-8 parts of curing agent, 1-2 parts of dispersant, 0.5-2 parts of leveling agent, 0.1-0.5 parts of stabilizer, and 0.1-0.7 parts of defoamer.

[0011] Further, the preparation method of the organosilicon modified epoxy resin is as follows: 50 parts by weight of bisphenol A type epoxy resin, 10-30 parts of hydroxyl-terminated polydimethylsiloxane, 1-5 parts of catalyst and 20-30 parts of xylene are added to a reaction vessel, heated to 100℃-150℃, stirred at a speed of 50r / min-300r / min for 1h-3h, and subjected to vacuum distillation to obtain organosilicon modified epoxy resin.

[0012] Furthermore, the molecular weight of the hydroxyl-terminated polydimethylsiloxane is 1000~3000;

[0013] The catalyst is tetraisopropyl titanate.

[0014] Furthermore, the particle size of the nano-calcium carbonate is 20nm~80nm.

[0015] Furthermore, the preparation method of the grafted modified graphene oxide is as follows:

[0016] Graphene oxide and N,N-dimethylformamide were mixed and ultrasonically dispersed for 15-20 minutes. Then, 4-dimethylaminopyridine and a compound containing phosphite groups were added. The mixture was stirred at 100-300 rpm for 1-5 hours at 80-120°C. After cooling to room temperature, the mixture was centrifuged and dried to obtain grafted modified graphene oxide.

[0017] Furthermore, the compound containing the phosphite group is at least one of triphenyl phosphite, diethyl phosphite, and 2-ethylhexyl diphosphite.

[0018] Further, the weight ratio of the graphene oxide, N,N-dimethylformamide, 4-dimethylaminopyridine and the compound containing phosphite groups is (1~10):(15~30):(5~12):(3~7).

[0019] Further, the preparation method of the active chromium oxide is as follows: 1 to 10 parts by weight of chromium oxide are added to the reaction vessel, and then 1 to 2 parts of titanate coupling agent are added. The mixture is stirred at 50°C to 80°C for 5 to 15 minutes at a speed of 500 r / min to 1000 r / min to obtain active chromium oxide.

[0020] In addition, the present invention also provides a method for preparing high-performance coil powder coatings, the method comprising the following steps:

[0021] Organosilicon-modified epoxy resin, carboxyl-terminated polyester resin, nano-calcium carbonate, grafted modified graphene oxide, active chromium oxide, polytetrafluoroethylene wax, curing agent, dispersant, leveling agent, stabilizer and defoamer are added to a mixer and premixed for 5 min to 15 min at a speed of 200 r / min to 500 r / min to obtain a premixed material.

[0022] The premixed material is fed into a twin-screw extruder for melt extrusion, tableting, crushing, and grinding to obtain a powder coating.

[0023] Furthermore, the melt extrusion process is as follows: the temperature of the first zone is 90℃~100℃, and the temperature of the second zone is 100℃~125℃.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. This invention combines silicone-modified epoxy resin and carboxyl-terminated polyester resin. After silicone modification, the -Si-O-Si- segments in the system have high flexibility and work synergistically with nano-calcium carbonate to help balance the adhesion and flexibility of the coating. The addition of grafted modified graphene oxide and active chromium oxide can significantly improve the mechanical strength of the coating and adapt to the bending and stamping deformation requirements of the roll material during processing.

[0026] 2. This invention grafts phosphite groups onto graphene oxide and applies them to this powder coating system. This allows the graphene oxide to form a three-dimensional network structure within the system. The chemical bonding not only improves the crosslinking stability of the graphene oxide in the system, but also provides a certain barrier effect due to the sheet-like structure of the graphene oxide. This also imparts longer-lasting weather resistance to the coating. Furthermore, the graphene oxide works synergistically with active chromium oxide to form a filling system that effectively fills microscopic defects in the resin matrix and exerts its chemical passivation effect, further improving the weather resistance and corrosion resistance of the coating.

[0027] 3. The components of this invention have excellent overall compatibility, and no problems such as orange peel, pinholes, or bubbles have appeared. While ensuring its application performance, the coating has excellent appearance performance and has good use value. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] A high-performance coil powder coating according to one embodiment of the present invention comprises the following raw materials in parts by weight:

[0031] The composition includes 20-40 parts of silicone-modified epoxy resin, 25-45 parts of carboxyl-terminated polyester resin, 3-7 parts of nano-calcium carbonate, 1-5 parts of grafted modified graphene oxide, 1-10 parts of active chromium oxide, 1-3 parts of polytetrafluoroethylene wax, 3-8 parts of curing agent, 1-2 parts of dispersant, 0.5-2 parts of leveling agent, 0.1-0.5 parts of stabilizer, and 0.1-0.7 parts of defoamer.

[0032] In one embodiment, the method for preparing the organosilicon-modified epoxy resin is as follows: 50 parts by weight of bisphenol A type epoxy resin, 10-30 parts by weight of hydroxyl-terminated polydimethylsiloxane, 1-5 parts by weight of catalyst and 20-30 parts by weight of xylene are added to a reaction vessel, heated to 100℃-150℃, stirred at a speed of 50r / min-300r / min for 1h-3h, and subjected to vacuum distillation to obtain the organosilicon-modified epoxy resin.

[0033] In one embodiment, the molecular weight of the hydroxyl-terminated polydimethylsiloxane is 1000-3000;

[0034] The catalyst is tetraisopropyl titanate.

[0035] In one embodiment, the particle size of the nano-calcium carbonate is 20 nm to 80 nm.

[0036] In one embodiment, the method for preparing the grafted modified graphene oxide is as follows:

[0037] Graphene oxide and N,N-dimethylformamide were mixed and ultrasonically dispersed for 15-20 minutes. Then, 4-dimethylaminopyridine and a compound containing phosphite groups were added. The mixture was stirred at 100-300 rpm for 1-5 hours at 80-120°C. After cooling to room temperature, the mixture was centrifuged and dried to obtain grafted modified graphene oxide.

[0038] In one embodiment, the compound containing the phosphite group is at least one of triphenyl phosphite, diethyl phosphite, and 2-ethylhexyl diphosphite.

[0039] In one embodiment, the weight ratio of the graphene oxide, N,N-dimethylformamide, 4-dimethylaminopyridine, and the compound containing phosphite groups is (1~10):(15~30):(5~12):(3~7).

[0040] In one embodiment, the drying process is carried out at a temperature of 60°C to 80°C for a time of 20 to 30 minutes.

[0041] In one embodiment, the active chromium oxide is prepared by adding 1 to 10 parts by weight of chromium oxide into a reaction vessel, then adding 1 to 2 parts of titanate coupling agent, and stirring at 50°C to 80°C for 5 to 15 minutes at a speed of 500 to 1000 r / min to obtain active chromium oxide.

[0042] In one embodiment, the curing agent is at least one of diphenylmethane diisocyanate and hexamethylene diisocyanate.

[0043] In one embodiment, the dispersant is at least one of polyethylene wax and polyamide wax.

[0044] In one embodiment, the leveling agent is at least one of acrylate leveling agents and silicone leveling agents.

[0045] In one embodiment, the stabilizer is zinc stearate.

[0046] In one embodiment, the defoamer is benzoin.

[0047] In addition, the present invention also provides a method for preparing high-performance coil powder coatings, the method comprising the following steps:

[0048] Organosilicon-modified epoxy resin, carboxyl-terminated polyester resin, nano-calcium carbonate, grafted modified graphene oxide, active chromium oxide, polytetrafluoroethylene wax, curing agent, dispersant, leveling agent, stabilizer and defoamer are added to a mixer and premixed for 5 min to 15 min at a speed of 200 r / min to 500 r / min to obtain a premixed material.

[0049] The premixed material is fed into a twin-screw extruder for melt extrusion, tableting, crushing, and grinding to obtain a powder coating.

[0050] In one embodiment, the melt extrusion process is as follows: the temperature of the first zone is 90℃~100℃, and the temperature of the second zone is 100℃~125℃.

[0051] After optimizing the composition and ingredient ratio, the above solution can produce powder coatings with flexibility, hardness, and weather resistance that meet the requirements for use in roll materials.

[0052] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments.

[0053] Example 1:

[0054] A method for preparing a high-performance coil powder coating, the method comprising the following steps:

[0055] By weight, 50 parts of bisphenol A type epoxy resin, 25 parts of hydroxyl-terminated polydimethylsiloxane, 3 parts of catalyst and 30 parts of xylene were added to a reaction vessel, heated to 120°C, stirred at 200 r / min for 2 h, and subjected to vacuum distillation to obtain organosilicon modified epoxy resin.

[0056] By weight, 7 parts of graphene oxide and 20 parts of N,N-dimethylformamide were mixed and ultrasonically dispersed for 15 min. Then, 8 parts of 4-dimethylaminopyridine and 5 parts of 2-ethylhexyl diphosphite were added. The mixture was stirred at 200 r / min for 2 h at 85 °C, cooled to room temperature, centrifuged, and dried at 65 °C for 30 min to obtain grafted modified graphene oxide.

[0057] Add 7 parts by weight of chromium oxide to the reactor, then add 2 parts of titanate coupling agent, and stir at 500 r / min for 10 min at 65°C to obtain active chromium oxide.

[0058] By weight, 35 parts of silicone-modified epoxy resin, 30 parts of carboxyl-terminated polyester resin, 5 parts of nano-calcium carbonate, 4 parts of grafted modified graphene oxide, 7 parts of active chromium oxide, 2 parts of polytetrafluoroethylene wax, 5 parts of diphenylmethane diisocyanate, 2 parts of polyethylene wax, 2 parts of acrylate leveling agent, 0.4 parts of zinc stearate, and 0.5 parts of benzoin were added to a mixer and premixed for 10 minutes at a speed of 300 r / min to obtain a premixed material.

[0059] The premixed material is fed into a twin-screw extruder, melt-extruded at a temperature of 100°C in the first zone and 110°C in the second zone, and then pressed, crushed, and ground to obtain a powder coating.

[0060] Example 2:

[0061] A method for preparing a high-performance coil powder coating, the method comprising the following steps:

[0062] By weight, 50 parts of bisphenol A type epoxy resin, 26 parts of hydroxyl-terminated polydimethylsiloxane, 4 parts of catalyst and 30 parts of xylene were added to a reaction vessel, heated to 120°C, stirred at 200 r / min for 2 h, and subjected to vacuum distillation to obtain organosilicon modified epoxy resin.

[0063] By weight, 8 parts of graphene oxide and 20 parts of N,N-dimethylformamide were mixed and ultrasonically dispersed for 15 min. Then, 10 parts of 4-dimethylaminopyridine and 7 parts of 2-ethylhexyl diphosphite were added. The mixture was stirred at 300 r / min for 2 h at 90 °C, cooled to room temperature, centrifuged, and dried at 65 °C for 30 min to obtain grafted modified graphene oxide.

[0064] Add 8 parts by weight of chromium oxide to the reactor, then add 2 parts of titanate coupling agent, and stir at 500 r / min for 10 min at 70°C to obtain active chromium oxide.

[0065] By weight, 36 parts of silicone-modified epoxy resin, 29 parts of carboxyl-terminated polyester resin, 6 parts of nano-calcium carbonate, 5 parts of grafted modified graphene oxide, 6 parts of active chromium oxide, 2 parts of polytetrafluoroethylene wax, 6 parts of diphenylmethane diisocyanate, 2 parts of polyethylene wax, 2 parts of acrylate leveling agent, 0.5 parts of zinc stearate, and 0.5 parts of benzoin were added to a mixer and premixed for 10 minutes at a speed of 300 r / min to obtain a premixed material.

[0066] The premixed material is fed into a twin-screw extruder, melt-extruded at a temperature of 100°C in the first zone and 110°C in the second zone, and then pressed, crushed, and ground to obtain a powder coating.

[0067] Example 3:

[0068] A method for preparing a high-performance coil powder coating, the method comprising the following steps:

[0069] According to the weight ratio, 50 parts of bisphenol A type epoxy resin, 28 parts of hydroxyl-terminated polydimethylsiloxane, 5 parts of catalyst and 30 parts of xylene were added to the reactor, heated to 120°C, stirred at 200 r / min for 2 h, and subjected to vacuum distillation to obtain organosilicon modified epoxy resin.

[0070] By weight, 8 parts of graphene oxide and 20 parts of N,N-dimethylformamide were mixed and ultrasonically dispersed for 15 min. Then, 12 parts of 4-dimethylaminopyridine and 6 parts of 2-ethylhexyl diphosphite were added. The mixture was stirred at 300 r / min for 2 h at 90 °C, cooled to room temperature, centrifuged, and dried at 65 °C for 30 min to obtain grafted modified graphene oxide.

[0071] Add 8 parts by weight of chromium oxide to the reactor, then add 2 parts of titanate coupling agent, and stir at 500 r / min for 10 min at 70°C to obtain active chromium oxide.

[0072] By weight, 35 parts of silicone-modified epoxy resin, 30 parts of carboxyl-terminated polyester resin, 7 parts of nano-calcium carbonate, 5 parts of grafted modified graphene oxide, 5 parts of activated chromium oxide, 3 parts of polytetrafluoroethylene wax, 7 parts of diphenylmethane diisocyanate, 2 parts of polyethylene wax, 2 parts of acrylate leveling agent, 0.5 parts of zinc stearate, and 0.5 parts of benzoin were added to a mixer and premixed for 10 minutes at a speed of 300 r / min to obtain a premixed material.

[0073] The premixed material is fed into a twin-screw extruder, melt-extruded at a temperature of 100°C in the first zone and 110°C in the second zone, and then pressed, crushed, and ground to obtain a powder coating.

[0074] Comparative Example 1:

[0075] The difference between Comparative Example 1 and Example 3 is that the epoxy resin in Comparative Example 1 was not modified with organosilicon, that is, the bisphenol A type epoxy resin was used directly. Otherwise, it was the same as Example 3.

[0076] Comparative Example 2:

[0077] The difference between Comparative Example 2 and Example 3 is that no silicone-modified epoxy resin was added in Comparative Example 2, while the rest is the same as in Example 3.

[0078] Comparative Example 3:

[0079] The difference between Comparative Example 3 and Example 3 is that no nano-calcium carbonate was added in Comparative Example 3, but otherwise it is the same as Example 3.

[0080] Comparative Example 4:

[0081] The difference between Comparative Example 4 and Example 3 is that the graphene oxide in Comparative Example 4 was not grafted and modified, but was directly added and used. Otherwise, it was the same as Example 3.

[0082] Comparative Example 5:

[0083] The difference between Comparative Example 5 and Example 3 is that no grafted modified graphene oxide was added in Comparative Example 5, but otherwise it is the same as Example 3.

[0084] Comparative Example 6:

[0085] The difference between Comparative Example 6 and Example 3 is that no active chromium oxide was added in Comparative Example 6, but otherwise it is the same as Example 3.

[0086] The powder coating samples prepared in Examples 1-3 and the comparative powder coating samples prepared in Comparative Examples 1-6 were coated onto 0.8 mm thick rust-removing and degreasing cold-rolled coils by electrostatic spraying. The curing temperature was 220℃, the curing time was 20 min, and the coating thickness was 70 μm. The appearance of the coatings is recorded in Table 1, and the performance of the coatings is recorded in Table 2.

[0087] The appearance of the coating is observed and recorded by those skilled in the art, with the use of auxiliary tools such as magnifying glasses when necessary.

[0088] Adhesion test: Refer to GB / T9286-1998;

[0089] Flexibility test: Referring to the SY / T6854-2012 standard, the coated roll material is bent at -20℃±2℃ for 1.5° and the surface coating of the roll material is observed for cracks and leaks.

[0090] Weather resistance test: Refer to GB / T 1865-2009, QUVB accelerated aging test 4000h;

[0091] Salt spray resistance test: Refer to GB / T 10125-2012, acid salt spray resistance for 4000h.

[0092] Table 1: Coating Appearance

[0093]

[0094] As shown in Table 1, the epoxy resin in Comparative Example 1 was not modified with silicone, resulting in poorer compatibility than in Example 3 and consequently poorer leveling properties, affecting the coating appearance. Comparative Example 2, without silicone-modified epoxy resin, showed a better appearance than Comparative Example 1, but also exhibited slight pinholes. This indicates that adding silicone-modified bisphenol A epoxy resin not only improves the coating's flexibility but also enhances the system's leveling performance, promoting a coating with superior appearance. Comparative Example 3, without nano-calcium carbonate, had no significant impact on the coating appearance. Comparative Example 4, without modified graphene oxide, showed a significantly worse coating appearance than Example 3, exhibiting agglomeration and surface defects. This demonstrates that grafting modification of graphene oxide can improve its compatibility within the system, promoting a better coating appearance. Comparative Example 5, without grafted modified graphene oxide, showed slight pinholes after curing due to the lack of grafted modified graphene oxide. Comparative Example 6, without active chromium oxide, had no significant impact on the coating appearance.

[0095] Table 2: Performance Test Results

[0096]

[0097] In Comparative Example 1, the epoxy resin was not modified with organosilicon, lacking the flexible chains of organosilicon, resulting in poorer flexibility, adhesion, and weather resistance compared to Example 3. In Comparative Example 2, the lack of organosilicon-modified epoxy resin led to a significant decrease in flexibility, weather resistance, and acid mist resistance. In Comparative Example 3, the absence of nano-calcium carbonate resulted in poor adhesion, flexibility, and weather resistance compared to Example 3. In Comparative Example 4, the lack of modified graphene oxide led to poor compatibility, with slight agglomeration in the system, significantly impacting adhesion, flexibility, weather resistance, and acid mist resistance, and resulting in poor coating quality. In Comparative Example 5, the absence of grafted modified graphene oxide significantly reduced weather resistance, indicating that adding grafted modified graphene oxide can significantly improve the coating's weather resistance. In Comparative Example 6, the absence of active chromium oxide significantly reduced weather resistance and acid mist resistance, indicating that adding active chromium oxide can also promote the coating's weather resistance and acid mist resistance.

[0098] Overall, the components and proportions of this invention form a complete formulation system with interactions, excellent compatibility, and superior coating appearance, without issues such as orange peel, pinholes, or bubbles. Furthermore, the powder coating of this invention exhibits excellent adhesion, flexibility, weather resistance, and acid mist resistance, making it more valuable for applications, especially suitable for roll material production.

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A high-performance coil powder coating, characterized in that, The high-performance coil powder coating comprises the following raw materials in parts by weight: The mixture comprises 20-40 parts of silicone-modified epoxy resin, 25-45 parts of carboxyl-terminated polyester resin, 3-7 parts of nano-calcium carbonate, 1-5 parts of grafted modified graphene oxide, 1-10 parts of active chromium oxide, 1-3 parts of polytetrafluoroethylene wax, 3-8 parts of curing agent, 1-2 parts of dispersant, 0.5-2 parts of leveling agent, 0.1-0.5 parts of stabilizer, and 0.1-0.7 parts of defoamer. The preparation method of the grafted modified graphene oxide is as follows: Graphene oxide and N,N-dimethylformamide were mixed and ultrasonically dispersed for 15-20 minutes. Then, 4-dimethylaminopyridine and a compound containing phosphite groups were added. The mixture was stirred at 100-300 rpm for 1-5 hours at 80-120°C. After cooling to room temperature, the mixture was centrifuged and dried to obtain grafted modified graphene oxide. The preparation method of the active chromium oxide is as follows: 1 to 10 parts by weight of chromium oxide are added to the reaction vessel, and then 1 to 2 parts of titanate coupling agent are added. The mixture is stirred at 50°C to 80°C for 5 to 15 minutes at a speed of 500 r / min to 1000 r / min to obtain active chromium oxide.

2. The high-performance coil powder coating according to claim 1, characterized in that, The preparation method of the organosilicon modified epoxy resin is as follows: 50 parts by weight of bisphenol A type epoxy resin, 10-30 parts by weight of hydroxyl-terminated polydimethylsiloxane, 1-5 parts by weight of catalyst and 20-30 parts by weight of xylene are added to a reaction vessel, heated to 100℃-150℃, stirred at a speed of 50r / min-300r / min for 1h-3h, and subjected to vacuum distillation to obtain organosilicon modified epoxy resin.

3. The high-performance coil powder coating according to claim 2, characterized in that, The molecular weight of the hydroxyl-terminated polydimethylsiloxane is 1000~3000; The catalyst is tetraisopropyl titanate.

4. The high-performance coil powder coating according to claim 1, characterized in that, The particle size of the nano-calcium carbonate is 20nm~80nm.

5. The high-performance coil powder coating according to claim 4, characterized in that, The compound containing the phosphite group is at least one of triphenyl phosphite and diethyl phosphite.

6. The high-performance coil powder coating according to claim 4, characterized in that, The weight ratio of the graphene oxide, N,N-dimethylformamide, 4-dimethylaminopyridine and the compound containing phosphite groups is (1~10):(15~30):(5~12):(3~7).

7. A method for preparing a high-performance coil powder coating, characterized in that, The preparation method is used to prepare the high-performance coil powder coating as described in any one of claims 1 to 6, and the preparation method includes the following steps: Organosilicon-modified epoxy resin, carboxyl-terminated polyester resin, nano-calcium carbonate, grafted modified graphene oxide, active chromium oxide, polytetrafluoroethylene wax, curing agent, dispersant, leveling agent, stabilizer and defoamer are added to a mixer and premixed for 5 min to 15 min at a speed of 200 r / min to 500 r / min to obtain a premixed material. The premixed material is fed into a twin-screw extruder for melt extrusion, tableting, crushing, and grinding to obtain a powder coating.

8. The preparation method according to claim 7, characterized in that, The melt extrusion process is as follows: the temperature of zone one is 90℃~100℃, and the temperature of zone two is 100℃~125℃.

Images