High-molecular heavy anti-corrosion material for improving quality of strip steel of hot rolling unit and preparation process thereof

Abstract

The invention relates to the field of anticorrosive coatings, in particular to a high-molecular heavy-duty anticorrosive material for improving the quality of strip steel of a hot rolling mill and a preparation process thereof. A high-molecular heavy anti-corrosion material for improving the quality of strip steel of a hot rolling mill comprises the following raw materials in parts by mass: 55-70 parts of aliphatic dicarboxylic acid alkoxide, 15-30 parts of modified polysiloxane, 2-4 parts of a pH regulator, 3-5 parts of a corrosion inhibitor, 1-3 parts of a preservative, 1-5 parts of a plasticizer, 2.5-5 parts of a wetting dispersant, 5-10 parts of filling particles and 30-50 parts of deionized water. The high-temperature-resistant anticorrosive paint prepared by the invention not only can be used as a special heavy-duty anticorrosive paint for a hot rolling unit in the iron and steel industry, but also has excellent high-temperature resistance, so that the durability of the high-temperature-resistant anticorrosive paint in a high-temperature and high-humidity environment is improved, and the high-temperature-resistant anticorrosive paint also shows excellent performance in the aspects of aging resistance, oxidation resistance, corrosion resistance and the like; therefore, the comprehensive performance requirements of related equipment on the high-temperature-resistant anticorrosive paint in the existing steel hot rolling production process are met, and the high-temperature-resistant anticorrosive paint has a very excellent application prospect.

Description

Technical Field

[0001] The present application relates to the field of anti-corrosion coatings, and in particular to a polymer heavy anti-corrosion material and a preparation process thereof for improving the quality of hot rolling mill strip. Background Art

[0002] In the hot rolling production process of steel, the finishing mill is a key equipment. Its working conditions are harsh, including high temperature, high humidity, and high corrosion. These factors work together to cause serious corrosion on the surface of the equipment. Especially when the rolling mill is in a long-term continuous operation state, the working environment further aggravates the oxidation and rust of metal parts, forming iron oxide scale. Therefore, the finishing rolling area is affected by the working environment and water quality, and the rolling mill body and related equipment in the rolling mill are seriously corroded. Due to the rough surface of the rusted equipment, the water vapor and dust generated during the rolling process are very easy to adhere to the surface of the rolling mill body and auxiliary equipment. During the rolling process, due to the water flushing of the frame and the vibration during the rolling process, the loosely attached foreign matter falls on the surface of the strip. If the auxiliary water cannot flush it away, it will be pressed into the strip, causing the quality blockage of iron scale ash or foreign matter pressing in, which in turn affects the quality of the product and causes frequent unplanned shutdowns for maintenance, mainly including roller printing and replacement shutdowns, which threaten the efficiency of the production line and the quality of the strip.

[0003] In view of the above problems, although fixed-point cleaning measures were taken in the early stage, the effect was limited and could not solve the problem permanently. With the increase in production speed and the demand for increased output, regular manual cleaning became more difficult, and the iron ash defect reappeared and tended to worsen. In order to overcome these problems, it is necessary to find a method that can effectively avoid equipment corrosion in the long term as soon as possible. Among them, polymer heavy anti-corrosion materials are one of the best ways to solve the above problems.

[0004] Although some anti-corrosion coatings for hot rolling equipment and environments have appeared in recent years, they still have many problems. For example, their service life is limited. In high temperature and high humidity environments, their protective effect will decrease over time, which requires regular re-coating to maintain protective performance, increasing maintenance costs and downtime; long-term exposure to high temperature, humidity and chemical substances (such as minerals, acids and alkalis in water) causes the aging of existing coatings to be rapid, thereby reducing their ability to prevent rust and may cause degradation of physical properties such as hardness and flexibility; in the presence of acid and alkali solutions or salt spray erosion, existing high temperature resistant anti-corrosion coatings may not provide sufficient resistance, making the equipment more susceptible to corrosion. Summary of the invention

[0005] In order to solve the above problems, the present application provides a polymer heavy-duty anti-corrosion material for improving the quality of hot rolling mill strip. It is aimed at solving the corrosion problem that has plagued the hot rolling system in the steel industry for many years. It can not only be used as a special heavy-duty anti-corrosion coating for the hot rolling mill in the steel industry, but also has excellent high temperature resistance, and further improves its durability in high temperature and high humidity environments. It also shows excellent performance in aging resistance, oxidation resistance and corrosion resistance, thereby meeting the comprehensive performance requirements of related equipment in the existing steel hot rolling production process for high temperature resistant anti-corrosion coatings, and has very excellent application prospects.

[0006] As a preferred solution, the polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip is composed of the following raw materials, in parts by mass: 55-70 parts of aliphatic dicarboxylic acid amino alcohol salt, 15-30 parts of modified polysiloxane, 2-4 parts of pH adjuster, 3-5 parts of corrosion inhibitor, 1-3 parts of preservative, 1-5 parts of plasticizer, 2.5-5 parts of wetting dispersant, 5-10 parts of filling particles, and 30-50 parts of deionized water.

[0007] As a preferred solution, the amino alcohol salt of aliphatic dicarboxylic acid is a combination of diethanolamine dodecenylsuccinate, diethanolamine sebacate and diethanolamine azelaic acid.

[0008] As a preferred solution, the mass ratio of the dodecenylsuccinic acid diethanolamine, the sebacic acid diethanolamine and the azelaic acid diethanolamine is (50-60): (3-5): (2-4).

[0009] As a preferred solution, the mass ratio of the dodecenylsuccinic acid diethanolamine, the sebacic acid diethanolamine and the azelaic acid diethanolamine is (54-56): (3-4): (2.5-3).

[0010] As a preferred scheme, the preparation method of the modified polysiloxane specifically includes the following steps: S1: adding phenyl silicone resin to a reaction container, and adding a mixed solution of toluene and deionized water, then adding γ-aminopropyltriethoxysilane and heating to 70-80°C for insulation reaction for 2-3 hours; S2: adding acrylamide and stirring at a speed of 60-80rpm for 20-30min until uniform, continuing to heat to 85-90°C, adding diisopropyl peroxide, and then dropwise adding styrene, a mixture of dialkyl maleate and perfluoroalkyl vinyl ether, and insulation reaction for 4-5 hours; S3: after the reaction is completed, continue to add hexamethoxymethylmelamine, and then continue insulation reaction for 6-8 hours. After completion, the product is filtered and washed, washed with toluene and deionized water, and dried for use after completion.

[0011] As a preferred solution, the mass ratio of the phenyl silicone resin, γ-aminopropyltriethoxysilane and acrylamide is (10-12): (0.5-0.8): (3.5-4.5).

[0012] As a preferred solution, in the mixed solution of toluene and deionized water, the mass ratio of toluene to deionized water is (3-4):1.

[0013] As a preferred solution, the mass ratio of acrylamide, styrene, dialkyl maleate, perfluoroalkyl vinyl ether and hexamethoxymethyl melamine is (3.5-4.5): (1.2-1.5): (0.4-0.6): (0.8-1): (0.4-0.5).

[0014] In this application, by adding the above-mentioned modified polysiloxane resin, the high temperature resistance and aging resistance of the anti-corrosion coating can be effectively improved to meet the use environment and performance requirements of steel hot rolling equipment. The modified polysiloxane resin can form a denser network by forming long chains and introducing multiple branches, and can graft or connect more heat-resistant active molecules by better connecting the coating system molecules through good side chain properties, and increase the adhesion between molecules and molecular chains in the internal system of the coating through the support of the multiple branched chain structure, thereby further reducing the micropore diameter and crack structure on the surface of the coating, limiting the molecular chain slip phenomenon caused by the high temperature and high humidity environment inside the coating, inhibiting the generation of cracks, and converting into more silver streaks, thereby greatly reducing the probability of internal migration collision reaction of active molecules and the penetration of water molecules and active molecules with water molecules as carriers in a long-term high temperature and high humidity environment, thereby obtaining excellent aging resistance, that is, service life, and further improving its corrosion resistance and other properties during application.

[0015] As a preferred solution, the mass ratio of the aliphatic dicarboxylic acid amino alcohol salt, the modified polysiloxane and the filling particles is (60-65): (18-22): (7-9).

[0016] As a preferred solution, the pH adjuster is at least one of sodium sulfamate, trisodium phosphate and sodium citrate.

[0017] As a preferred solution, the pH adjuster is sodium sulfamate or sodium citrate.

[0018] As a preferred solution, the corrosion inhibitor is a combination of sodium phytate and sodium molybdate.

[0019] As a preferred solution, the mass ratio of sodium phytate to sodium molybdate is (4-5):(0.6-1).

[0020] As a preferred solution, the mass ratio of sodium phytate to sodium molybdate is (4-4.5):(0.6-0.8).

[0021] As a preferred solution, the preservative is at least one of benzotriazole, mercaptobenzothiazole and imidazoline.

[0022] As a preferred solution, the preservative is benzotriazole or imidazoline.

[0023] As a preferred solution, the plasticizer is a combination of glycerol and dioctyl phthalate.

[0024] As a preferred solution, the mass ratio of glycerol to dioctyl phthalate is (6-8):(1-1.5).

[0025] As a preferred solution, the mass ratio of glycerol to dioctyl phthalate is (6.5-7):(1-1.2).

[0026] As a preferred solution, the wetting and dispersing agent is a composition of octylphenol polyoxyethylene ether, diisopropyl phosphate and epoxy block polyether.

[0027] As a preferred solution, the mass ratio of octylphenol polyoxyethylene ether, diisopropyl phosphate and epoxy block polyether is (6-7): (1-1.5): (2.5-3.5).

[0028] As a preferred solution, the mass ratio of the octylphenol polyoxyethylene ether, diisopropyl phosphate and epoxy block polyether is (6-6.5): (1-1.2): (2.8-3.2).

[0029] As a preferred solution, the HLB value of the octylphenol polyoxyethylene ether is 8-14.

[0030] As a preferred solution, the HLB value of the octylphenol polyoxyethylene ether is 9-10.

[0031] As a preferred solution, the weight average molecular weight of the epoxy block polyether is 8000 to 12000 Da.

[0032] As a preferred solution, the content of ethylene oxide blocks in the epoxy block polyether is 70 to 80 wt%.

[0033] As a preferred solution, the filling particles are a composition of silicon dioxide microspheres, titanium dioxide and sericite powder.

[0034] As a preferred solution, the mass ratio of the silica microspheres, titanium dioxide and sericite powder is (5-6): (0.3-0.5): (3-3.5).

[0035] As a preferred solution, the average particle size of the silica microspheres is 2 to 4 μm.

[0036] As a preferred solution, the average particle size of the silica microspheres is 2 to 2.5 μm.

[0037] As a preferred solution, the titanium dioxide is rutile titanium dioxide; the average particle size of the titanium dioxide is 0.1 to 0.15 μm.

[0038] As a preferred solution, the average particle size of the sericite powder is 5 to 6.5 μm.

[0039] As a preferred solution, the average particle size of the sericite powder is 5 to 5.5 μm.

[0040] The second aspect of the present application provides a preparation process of the above-mentioned high molecular weight heavy anti-corrosion material for improving the quality of hot rolling mill strip, which specifically includes the following steps: S1: Add modified polysiloxane to a stirring kettle, slowly stir at 60-80 rpm for 40-60 minutes at 25-35°C, then add aliphatic dicarboxylic acid amino alcohol salt, pH adjuster, corrosion inhibitor, preservative and wetting dispersant respectively, and stir for 20-30 minutes each time; S2: Finally, add plasticizer, filling particles and deionized water and stir at 100-140 rpm for 1-2 hours until the required viscosity is adjusted to obtain a coating liquid; S3: When in use, apply the coating liquid on the steel hot rolling equipment with a coating thickness of 80-100 μm, dry it in a natural environment for 2-3 hours, and then cure it in a large oven at 100-120°C for 3-4 hours.

[0041] The beneficial effects of this application are:

[0042] 1. The polymer heavy anti-corrosion material provided in the present application for improving the quality of hot rolling mill strip has excellent high temperature resistance and good durability in high temperature and high humidity environments. It also exhibits excellent performance in terms of aging resistance, oxidation resistance and corrosion resistance, thereby meeting the comprehensive performance requirements of related equipment in the existing steel hot rolling production process for high temperature resistant anti-corrosion coatings, and has very excellent application prospects.

[0043] 2. A polymer heavy-duty anti-corrosion material for improving the quality of hot rolling mill strip provided in the present application, wherein the modified polysiloxane resin added thereto can form long chains and introduce multiple branches, and can better connect the coating system molecules through good side chain properties to form a denser network, while grafting or connecting more heat-resistant active molecules, and increase the adhesion between molecules and molecular chains in the internal system of the coating through the support of the multiple branched structure, thereby further reducing the micropore size and crack structure on the coating surface, limiting the molecular chain slippage caused by the high temperature and high humidity environment inside the coating, inhibiting the formation of cracks, and converting them into more silver streaks, thereby greatly reducing the probability of internal migration and collision reactions of active molecules and the penetration of water molecules and active molecules with water molecules as carriers in a long-term high temperature and high humidity environment, thereby ensuring the corrosion resistance and aging resistance of the anti-corrosion coating.

[0044] 3. The polymer heavy anti-corrosion material provided in the present application for improving the quality of hot rolling mill strip, the specific wetting and dispersing agent composition added thereto can not only achieve a good uniform dispersion effect, but also the multi-layer barrier film structure formed therein can play a benign barrier role in the curing process of the anti-corrosion coating system, which not only limits the rapid aggregation phenomenon between solid particles during the curing process, but also plays a spacing role in the internal molecular chain three-dimensional network, controls the steric hindrance of the internal system, thereby helping to improve the overall corrosion resistance and aging resistance of the anti-corrosion coating, while increasing the penetration resistance and penetration path of water molecules.

[0045] 4. The polymer heavy anti-corrosion material provided in the present application for improving the quality of hot rolling mill strip is different from the commonly used multi-layer coating (2 to 3 coatings) and high thickness (200 to 300 μm) of the existing anti-corrosion coatings in the application of steel hot rolling equipment. The coating with a thickness of 80 to 100 μm obtained by a single coating can exhibit heat resistance, aging resistance and corrosion resistance that exceed the existing anti-corrosion coatings, and has a good rust inhibition effect in the application process of hot rolling mills in the steel industry. DETAILED DESCRIPTION

[0046] The following will further explain and implement the technical solutions in the above invention content of this application in the form of specific implementation schemes. The following specific implementation schemes are only practical examples used to illustrate and explain the contents of the technical solutions in the specification and should not limit the scope of the claims to be protected by this application.

[0047] Example 1

[0048] Example 1 The first aspect provides a high molecular weight heavy anti-corrosion material for improving the quality of hot rolling mill strip. The raw materials are, in parts by mass: 60.5 parts of aliphatic dicarboxylic acid amino alcohol salt, 21.4 parts of modified polysiloxane, 2.6 parts of pH adjuster, 3.8 parts of corrosion inhibitor, 1.2 parts of preservative, 3.2 parts of plasticizer, 4.5 parts of wetting dispersant, 8.5 parts of filling particles, and 38.8 parts of deionized water.

[0049] The amino alcohol salt of aliphatic dicarboxylic acid is a composition of dodecenylsuccinic acid diethanolamine, sebacic acid diethanolamine and azelaic acid diethanolamine, and the mass ratio of the three is 55:3:2.5.

[0050] The preparation method of modified polysiloxane specifically includes the following steps, calculated by mass: S1: adding 10.5 parts of phenyl silicone resin to a reaction container, and adding a mixed solution of toluene and deionized water (a total of 240 parts), then adding 0.6 parts of γ-aminopropyltriethoxysilane and heating to 75°C for thermal insulation reaction for 2.5 hours; S2: adding 4.2 parts of acrylamide and stirring at a speed of 80 rpm for 25 minutes until uniform, continuing to heat to 90°C, adding 0.11 parts of diisopropyl peroxide, and then dropwise adding 1.3 parts of styrene, 0.55 parts of a mixture of dialkyl maleate and 0.9 parts of perfluoroalkyl vinyl ether, and thermal insulation reaction for 4.5 hours; S3: after the reaction is completed, continue to add 0.44 parts of hexamethoxymethylmelamine, and then continue to thermal insulation reaction for 6 hours. After completion, the product is filtered and washed, washed with toluene and deionized water, and dried for use after completion.

[0051] In the mixed solution of toluene and deionized water, the mass ratio of toluene to deionized water is 3:1.

[0052] Phenyl silicone resin was purchased from Shandong Dayi Chemical Co., Ltd., China, with the model number DY-AB301.

[0053] The pH regulator is sodium aminosulfonate; the corrosion inhibitor is a combination of sodium phytate and sodium molybdate, and the mass ratio of the two is 4:0.7.

[0054] The preservative is benzotriazole; the plasticizer is a combination of glycerol and dioctyl phthalate, and the mass ratio of the two is 6.5:1.

[0055] The wetting and dispersing agent is a composition of octylphenol polyoxyethylene ether, diisopropyl phosphate and epoxy block polyether, and the mass ratio of the three is 6.2:1.1:3.

[0056] Octylphenol polyoxyethylene ether has an HLB value of 9 and was purchased from Haian Petrochemical Plant in Jiangsu Province, China.

[0057] The weight average molecular weight of the epoxy block polyether is 11000 Da, the content of ethylene oxide block is 80 wt %, and the epoxy block polyether product of model L88 sold by BASF of Germany is purchased.

[0058] The filling particles are a composition of silicon dioxide microspheres, titanium dioxide and sericite powder, and the mass ratio of the three is 5.5:0.4:3.1.

[0059] The average particle size of the silica microspheres is 2.2 μm; the titanium dioxide is rutile titanium dioxide with an average particle size of 0.12 μm; and the average particle size of the sericite powder is 5.2 μm.

[0060] The second aspect of the present embodiment provides a method for preparing the above-mentioned high molecular weight anti-corrosion material for improving the quality of hot rolling mill strip, which specifically includes the following steps: S1: Add modified polysiloxane to a stirring kettle, slowly stir at 80 rpm at 30°C for 50 minutes, then add aliphatic dicarboxylic acid amino alcohol salt, pH adjuster, corrosion inhibitor, preservative and wetting dispersant respectively, and stir for 25 minutes each time; S2: Finally, add plasticizer, filling particles and deionized water and stir at 120 rpm for 1.5 hours until the required viscosity is adjusted to obtain a coating liquid; S3: When in use, apply the coating liquid on the steel hot rolling equipment with a coating thickness of 80 μm, dry it in a natural environment for 2.5 hours, and then cure it in a large oven at 110°C for 4 hours.

[0061] Example 2

[0062] The specific implementation of this embodiment is basically the same as that of Example 1, with the only difference being that the high molecular weight anti-corrosion material for improving the quality of the hot rolling mill strip is composed of the following raw materials, in parts by mass: 59 parts of aliphatic dicarboxylic acid amino alcohol salt, 18.5 parts of modified polysiloxane, 2.8 parts of pH adjuster, 3.4 parts of corrosion inhibitor, 1.3 parts of preservative, 3.6 parts of plasticizer, 3.6 parts of wetting dispersant, 7.2 parts of filling particles, and 35.5 parts of deionized water.

[0063] The amino alcohol salt of aliphatic dicarboxylic acid is a composition of dodecenylsuccinic acid diethanolamine, sebacic acid diethanolamine and azelaic acid diethanolamine, and the mass ratio of the three is 50:5:4.

[0064] The filling particles are a composition of silicon dioxide microspheres, titanium dioxide and sericite powder, and the mass ratio of the three is 6:0.3:3.5.

[0065] Example 3

[0066] The specific implementation of this embodiment is basically the same as that of Example 1, with the only difference being that the high molecular weight anti-corrosion material for improving the quality of the hot rolling mill strip is composed of the following raw materials, in parts by mass: 65 parts of aliphatic dicarboxylic acid amino alcohol salt, 22 parts of modified polysiloxane, 3.2 parts of pH adjuster, 3.2 parts of corrosion inhibitor, 1.1 parts of preservative, 4.4 parts of plasticizer, 4.2 parts of wetting dispersant, 9 parts of filling particles, and 39.2 parts of deionized water.

[0067] The amino alcohol salt of aliphatic dicarboxylic acid is a composition of dodecenylsuccinic acid diethanolamine, sebacic acid diethanolamine and azelaic acid diethanolamine, and the mass ratio of the three is 60:3:2.

[0068] The filling particles are a composition of silicon dioxide microspheres, titanium dioxide and sericite powder, and the mass ratio of the three is 5:0.5:3.

[0069] Comparative Example 1

[0070] The specific implementation method of this comparative example is basically the same as that of Example 1, except that: the high molecular weight anti-corrosion material for improving the quality of the hot rolling mill strip, in parts by mass, the raw materials are: 68.5 parts of aliphatic dicarboxylic acid amino alcohol salt, 10.5 parts of modified polysiloxane, 2.6 parts of pH adjuster, 3.8 parts of corrosion inhibitor, 1.2 parts of preservative, 3.2 parts of plasticizer, 4.5 parts of wetting dispersant, 8.5 parts of filling particles, and 38.8 parts of deionized water.

[0071] Comparative Example 2

[0072] The specific implementation method of this comparative example is basically the same as that of Example 1, except that: the high molecular weight anti-corrosion material for improving the quality of the hot rolling mill strip, in parts by mass, the raw materials are: 52.5 parts of aliphatic dicarboxylic acid amino alcohol salt, 30.8 parts of modified polysiloxane, 2.6 parts of pH adjuster, 3.8 parts of corrosion inhibitor, 1.2 parts of preservative, 3.2 parts of plasticizer, 4.5 parts of wetting dispersant, 2.2 parts of filling particles, and 45 parts of deionized water.

[0073] Comparative Example 3

[0074] The specific implementation of this comparative example is basically the same as that of Example 1, except that the amino alcohol salt of aliphatic dicarboxylic acid is a composition of diethanolamine dodecenylsuccinate, diethanolamine sebacic acid and diethanolamine azelaic acid, and the mass ratio of the three is 59:1.5:0.

[0075] Comparative Example 4

[0076] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified polysiloxane specifically includes the following steps, calculated by mass: S1: adding 10.5 parts of phenyl silicone resin to a reaction container, and adding a mixed solution of toluene and deionized water (a total of 240 parts), then adding 0.1 parts of γ-aminopropyltriethoxysilane and heating to 75°C for insulation reaction for 2.5 hours; S2: adding 8.5 parts of acrylamide and stirring at a speed of 80 rpm for 25 minutes until uniform, continuing to heat to 90°C, adding 0.13 parts of diisopropyl peroxide, and then dropwise adding 2.8 parts of styrene, 0.1 parts of a mixture of dialkyl maleate and 2.2 parts of perfluoroalkyl vinyl ether, and insulation reaction for 4.5 hours; S3: after the reaction is completed, continue to add 0.2 parts of hexamethoxymethylmelamine, and then continue to insulation reaction for 6 hours. After completion, the product is filtered and washed, washed with toluene and deionized water, and dried for use after completion.

[0077] Comparative Example 5

[0078] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified polysiloxane specifically includes the following steps, calculated by mass: S1: adding 10.5 parts of phenyl silicone resin to a reaction container, and adding a mixed solution of toluene and deionized water (a total of 240 parts), then adding 0.6 parts of γ-aminopropyltriethoxysilane and heating to 75°C for insulation reaction for 2.5 hours; S2: adding 2.5 parts of acrylamide and stirring at 80 rpm for 25 minutes until uniform, continuing to heat to 90°C, adding 0.09 parts of diisopropyl peroxide, and then dropwise adding 0.5 parts of styrene, 0.1 parts of a mixture of dialkyl maleate and 0.2 parts of perfluoroalkyl vinyl ether, and insulation reaction for 4.5 hours; S3: after the reaction is completed, continue to add 0.85 parts of hexamethoxymethylmelamine, and then continue to insulation reaction for 6 hours. After completion, the product is filtered and washed, washed with toluene and deionized water, and dried for use after completion.

[0079] Comparative Example 6

[0080] The specific implementation of this comparative example is basically the same as that of Example 1, except that the wetting and dispersing agent is a composition of octylphenol polyoxyethylene ether, diisopropyl phosphate and epoxy block polyether, and the mass ratio of the three is 2:2:1.

[0081] Comparative Example 7

[0082] The specific implementation of this comparative example is basically the same as that of Example 1, except that the wetting and dispersing agent is a composition of octylphenol polyoxyethylene ether and epoxy block polyether, and the mass ratio of the two is 1:2.

[0083] Performance Evaluation

[0084] High temperature resistance test: The cured anti-corrosion coatings prepared in the examples and comparative examples were tested. The samples were stored in a constant temperature environment at 450°C for 24 hours. If the coating fell off, was damaged or cracked, it was considered unqualified. Otherwise, it was qualified. 50 groups of samples were tested in each group, and the qualified rate results were recorded in Table 1.

[0085] Aging resistance test: The cured anti-corrosion coatings prepared in the examples and comparative examples were tested. The test specimens were placed in an environment of 105±2°C and 75±2% relative humidity for aging resistance test. The surface conditions of the specimens were recorded every 200 hours to observe whether there was any damage, cracking or blistering. The initial time of the occurrence of the above phenomena was taken for the test, and the results were recorded in Table 1.

[0086] Moisture permeation resistance test: The cured anti-corrosion coatings prepared in the embodiments and comparative examples were tested for moisture permeation resistance according to GB / T 1037-2021. The test values ​​were averaged over 10 tests and recorded in Table 1.

[0087] Salt spray corrosion resistance test: The cured anticorrosion coatings prepared in the examples and comparative examples were tested at an ambient temperature of 80±2°C, a humidity of 90±2%, a 5wt% NaCl solution, and a spraying rate of 2mL / 16h·80cm 2 The salt spray corrosion resistance test time is 800h. After the test, observe whether there is corrosion damage, yellowing, cracking or blistering. If there is, it is recorded as unqualified, otherwise it is qualified. Each group tests 50 groups of samples, and the qualified rate results are recorded in Table 1.

[0088] Table 1 Performance test results

[0089]

[0090] It can be seen from the examples and comparative examples of the present application and the data results in Table 1 that examples 1 to 3 of the present application have obvious advantages over comparative examples 1 to 7 in terms of high temperature resistance, aging resistance and corrosion resistance. This is mainly due to the combined effect of the modified polysiloxane resin and the specific auxiliary composition specified in the present application. Comparative examples 1 to 7 do not use suitable modified polysiloxane resins and specific auxiliary compositions, resulting in poor network density inside the coating system after the coating is cured, excessive inter-molecular chain pores, and fewer internal hydrophobic molecules, which makes it unable to cope with the penetration of water molecules and active molecules under high temperature and high humidity environments, and the migration and collision of internal molecules are serious, which greatly reduces the barrier effect of the coating on moisture and the prevention effect of internal side reactions, and thus has worse aging resistance, high temperature resistance and corrosion resistance.

Claims

1. A high molecular weight anti-corrosion material for improving the quality of hot rolling mill strip, characterized by: The raw materials are, by mass: 55-70 parts of aliphatic dicarboxylic acid amino alcohol salt, 15-30 parts of modified polysiloxane, 2-4 parts of pH adjuster, 3-5 parts of corrosion inhibitor, 1-3 parts of preservative, 1-5 parts of plasticizer, 2.5-5 parts of wetting and dispersing agent, 5-10 parts of filling particles, and 30-50 parts of deionized water; The amino alcohol salt of the aliphatic dicarboxylic acid is a combination of diethanolamine dodecenylsuccinate, diethanolamine sebacate and diethanolamine azelaic acid; The mass ratio of the dodecenylsuccinic acid diethanolamine, sebacic acid diethanolamine and azelaic acid diethanolamine is (50-60): (3-5): (2-4); The pH regulator is at least one of sodium sulfamate, trisodium phosphate and sodium citrate; The corrosion inhibitor is a combination of sodium phytate and sodium molybdate; The mass ratio of sodium phytate to sodium molybdate is (4-5): (0.6-1); The preservative is at least one of benzotriazole, mercaptobenzothiazole and imidazoline; The plasticizer is a composition of glycerol and dioctyl phthalate; The mass ratio of glycerol to dioctyl phthalate is (6-8):(1-1.5); The wetting and dispersing agent is a composition of octylphenol polyoxyethylene ether, diisopropyl phosphate and epoxy block polyether; The mass ratio of the octylphenol polyoxyethylene ether, diisopropyl phosphate and epoxy block polyether is (6-7): (1-1.5): (2.5-3.5); The filling particles are a composition of silicon dioxide microspheres, titanium dioxide and sericite powder.

2. The polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip according to claim 1, characterized in that: The preparation method of the modified polysiloxane specifically comprises the following steps: S1: adding phenyl silicone resin into a reaction container, and adding a mixed solution of toluene and deionized water, then adding γ-aminopropyltriethoxysilane and heating to 70-80°C for heat preservation and reaction for 2-3 hours; S2: adding acrylamide and stirring at a speed of 60-80 rpm for 20-30 minutes until uniform, continuing to heat to 85-90°C, adding diisopropyl peroxide, and then dropwise adding styrene, a mixture of dialkyl maleate and perfluoroalkyl vinyl ether, and heat preservation and reaction for 4-5 hours; S3: after the reaction is completed, continuing to add hexamethoxymethylmelamine, and then continuing to heat preservation and reaction for 6-8 hours. After completion, filtering and washing the product, washing with toluene and deionized water, and drying for use after completion.

3. The polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip according to claim 2, characterized in that: The mass ratio of the phenyl silicone resin, γ-aminopropyltriethoxysilane and acrylamide is (10-12): (0.5-0.8): (3.5-4.5).

4. The polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip according to claim 3, characterized in that: The mass ratio of acrylamide, styrene, dialkyl maleate, perfluoroalkyl vinyl ether and hexamethoxymethyl melamine is (3.5-4.5): (1.2-1.5): (0.4-0.6): (0.8-1): (0.4-0.5).

5. The polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip according to claim 4, characterized in that: The mass ratio of the aliphatic dicarboxylic acid amino alcohol salt, the modified polysiloxane and the filling particles is (60-65): (18-22): (7-9).

6. The polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip according to claim 5, characterized in that: The HLB value of the octylphenol polyoxyethylene ether is 8-14.

7. The polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip according to claim 6, characterized in that: The weight average molecular weight of the epoxy block polyether is 8000-12000 Da; the content of ethylene oxide blocks in the epoxy block polyether is 70-80 wt %.

8. The polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip according to claim 7, characterized in that: The mass ratio of the silicon dioxide microspheres, titanium dioxide and sericite powder is (5-6): (0.3-0.5): (3-3.5).

9. The polymer heavy anti-corrosion material for improving the quality of hot rolling mill strip according to claim 8, characterized in that: The average particle size of the silicon dioxide microspheres is 2 to 4 μm; the titanium dioxide is rutile titanium dioxide; the average particle size of the titanium dioxide is 0.1 to 0.15 μm; and the average particle size of the sericite powder is 5 to 6.5 μm.

10. A process for preparing a high molecular weight anti-corrosion material for improving the quality of hot rolling mill strip according to any one of claims 1 to 9, characterized in that: The specific steps include: S1: Add the modified polysiloxane into a stirring kettle, slowly stir at 60-80 rpm for 40-60 min at 25-35° C., then add aliphatic dicarboxylic acid amino alcohol salt, pH adjuster, corrosion inhibitor, preservative and wetting dispersant respectively, stirring for 20-30 min each time; S2: Finally, add plasticizer, filler particles and deionized water, stir at 100-140 rpm for 1-2 h until the desired viscosity is adjusted to obtain a coating liquid; S3: When using, apply the coating liquid on steel hot rolling equipment with a coating thickness of 80-100 μm, dry it in a natural environment for 2-3 h, and then cure it in a large oven at 100-120° C. for 3-4 h.

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