High molecular weight anti-corrosion material and its preparation process for improving the quality of hot rolling mill strip

Abstract

The present application relates to the field of anti-corrosion coatings, and in particular to a polymer heavy-duty anti-corrosion material and its preparation process for improving the quality of hot rolling mill strip. The polymer heavy-duty anti-corrosion material for improving the quality of hot rolling mill strip comprises, 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 regulator, 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 filler particles, and 30-50 parts of deionized water. The high-temperature resistant anti-corrosion coating prepared by the present application can not only be used as a special heavy-duty anti-corrosion coating for hot rolling mills in the steel industry, but also has excellent high-temperature resistance, thereby improving its durability in high-temperature and high-humidity environments, and 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.

Description

Technical Field

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

[0002] In the hot-rolling steel production process, the finishing mill, a critical piece of equipment, operates under harsh conditions, including high temperature, high humidity, and high corrosion. These factors combine to cause severe corrosion on the equipment surfaces. Especially when the mill is in continuous operation for long periods of time, the operating environment further exacerbates oxidation and corrosion of metal components, forming scale. Consequently, the finishing mill area, affected by the operating environment and water quality, suffers from severe corrosion of the mill body and associated equipment. Due to the rough surface of rusted equipment, moisture and dust generated during the rolling process easily adhere to the mill body and auxiliary equipment. During the rolling process, loosely adhered foreign matter is affected by water flushing from the mill stand and vibrations during rolling, causing it to fall onto the strip surface. If the auxiliary water cannot flush it away, it is pressed into the strip, causing scale dust or foreign matter to be trapped, thus affecting product quality and leading to frequent unscheduled maintenance downtime, primarily for roll printing and replacement, posing a threat to line efficiency and strip quality.

[0003] Although targeted cleaning measures were initially implemented to address these issues, their effectiveness was limited and did not provide a lasting solution. With increasing production speeds and output demands, regular manual cleaning became increasingly difficult, and the iron ash defect reappeared and showed signs of worsening. To overcome these issues, a method to effectively prevent equipment corrosion over the long term was urgently needed. Polymer heavy-duty anti-corrosion materials were one of the best solutions.

[0004] Although some anti-corrosion coatings for hot-rolling equipment and environments have emerged 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; under long-term exposure to high temperature, humidity and chemical substances (such as minerals, acids and alkalis in water), existing coatings age quickly, 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 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 that improves 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. It also improves its durability in high-temperature and high-humidity environments, and 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-duty anti-corrosion material for improving the quality of hot rolling mill strip steel is composed of the following raw materials, in parts by mass: 55 to 70 parts of aliphatic dicarboxylic acid amino alcohol salt, 15 to 30 parts of modified polysiloxane, 2 to 4 parts of pH regulator, 3 to 5 parts of corrosion inhibitor, 1 to 3 parts of preservative, 1 to 5 parts of plasticizer, 2.5 to 5 parts of wetting and dispersing agent, 5 to 10 parts of filling particles, and 30 to 50 parts of deionized water.

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

[0008] As a preferred solution, the mass ratio of the dodecenylsuccinic acid diethanolamine, the sebacate 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 sebacate diethanolamine and the azelaic acid diethanolamine is (54-56): (3-4): (2.5-3).

[0010] As a preferred solution, the preparation method of the modified polysiloxane specifically includes the following steps: S1: adding phenyl silicone resin to a reaction vessel, and adding a mixed solution of toluene and deionized water, then adding γ-aminopropyltriethoxysilane and heating to 70-80°C and keeping the temperature for 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 keeping the temperature for reaction for 4-5 hours; S3: after the reaction is completed, continuing to add hexamethoxymethylmelamine, and then continuing to keep the temperature for reaction for 6-8 hours. After completion, the product is filtered and washed with toluene and deionized water, and then dried for use.

[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, while better connecting the coating system molecules through good side chain properties, grafting or connecting more heat-resistant active molecules, and increasing 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 diameter and crack structure on the coating surface, 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 it into more silver grain states, thereby greatly reducing the probability of internal migration 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 obtaining excellent aging resistance, i.e., 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 the 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 silica 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 for 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 tank, slowly stir at a speed of 60 to 80 rpm at 25 to 35°C for 40 to 60 minutes, then add aliphatic dicarboxylic acid amino alcohol salt, pH regulator, corrosion inhibitor, preservative and wetting dispersant respectively, and stir for 20 to 30 minutes each time; S2: Finally, add plasticizer, filling particles and deionized water and stir at a speed of 100 to 140 rpm for 1 to 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 to 100 μm, dry it in a natural environment for 2 to 3 hours, and then cure it in a large oven at 100 to 120°C for 3 to 4 hours.

[0041] This application has the following beneficial effects:

[0042] 1. The polymer heavy anti-corrosion material provided in this 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 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.

[0043] 2. The present application provides a high-molecular-weight heavy-duty anti-corrosion material for improving the quality of hot rolling mill strip. The modified polysiloxane resin added thereto can form a denser network by forming long chains and introducing multiple branches, while better connecting the coating system molecules through good side chain properties, and grafting or connecting more heat-resistant active molecules. The support of the multiple-branched structure increases the adhesion between molecules and molecular chains in the internal system of the coating, thereby further reducing the micropore size and crack structure on the coating surface, limiting the molecular chain slippage phenomenon caused by the high temperature and high humidity environment inside the coating, inhibiting the generation of cracks, and converting it into more silver-grained states, 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-duty anti-corrosion material provided in the present application for improving the quality of hot rolling mill strip, the specific wetting and dispersant 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 spatial steric hindrance of the internal system, and thereby helps 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 this application for improving the quality of hot rolling mill strip is different from the existing commonly used anti-corrosion coating multi-layer coating (2 to 3 coatings) and high thickness (200 to 300 μm) method in its application in 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 illustrate and implement the technical solutions in the above invention content of this application in the form of specific implementation plans. The following specific implementation plans are only practical examples used to illustrate and explain the content 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 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 regulator, 3.8 parts of corrosion inhibitor, 1.2 parts of preservative, 3.2 parts of plasticizer, 4.5 parts of wetting and dispersing agent, 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 diethanolamine dodecenylsuccinate, diethanolamine sebacate and diethanolamine azelaic acid, 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 2.5 hours; S2: adding 4.2 parts of acrylamide and stirring at 80 rpm for 25 minutes until uniform, continuing to heat to 90°C, adding 0.11 parts of diisopropylbenzene peroxide, and then dropwise adding 1.3 parts of styrene, 0.55 parts of dialkyl maleate and 0.9 parts of perfluoroalkyl vinyl ether, and heating for 4.5 hours; S3: after the reaction is completed, continue to add 0.44 parts of hexamethoxymethylmelamine, and then continue to heat for 6 hours. After completion, the product is filtered and washed, washed with toluene and deionized water, and dried for use.

[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 composition 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 epoxy block polyether has a weight average molecular weight of 11,000 Da and an ethylene oxide block content of 80 wt %. The epoxy block polyether was purchased from BASF, Germany, and is a model L88 epoxy block polyether product.

[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 this 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 tank, slowly stir at 80 rpm at 30°C for 50 minutes, then add aliphatic dicarboxylic acid amino alcohol salt, pH regulator, corrosion inhibitor, preservative and wetting dispersant respectively, and stir for 25 minutes each time; S2: Finally, add plasticizer, filler 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 regulator, 3.4 parts of corrosion inhibitor, 1.3 parts of preservative, 3.6 parts of plasticizer, 3.6 parts of wetting and dispersing agent, 7.2 parts of filler particles, and 35.5 parts of deionized water.

[0063] The amino alcohol salt of aliphatic dicarboxylic acid is a composition of dodecenylsuccinic acid diethanolamine, sebacate 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 regulator, 3.2 parts of corrosion inhibitor, 1.1 parts of preservative, 4.4 parts of plasticizer, 4.2 parts of wetting and dispersing agent, 9 parts of filler particles, and 39.2 parts of deionized water.

[0067] The amino alcohol salt of aliphatic dicarboxylic acid is a composition of diethanolamine dodecenylsuccinate, diethanolamine sebacate and diethanolamine azelaic acid, 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 of this comparative example 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: 68.5 parts of aliphatic dicarboxylic acid amino alcohol salt, 10.5 parts of modified polysiloxane, 2.6 parts of pH regulator, 3.8 parts of corrosion inhibitor, 1.2 parts of preservative, 3.2 parts of plasticizer, 4.5 parts of wetting and dispersing agent, 8.5 parts of filler 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, with the only difference being that: the high molecular weight heavy anti-corrosion material for improving the quality of the hot rolling mill strip is composed of the following raw materials, in parts by mass: 52.5 parts of aliphatic dicarboxylic acid amino alcohol salt, 30.8 parts of modified polysiloxane, 2.6 parts of pH regulator, 3.8 parts of corrosion inhibitor, 1.2 parts of preservative, 3.2 parts of plasticizer, 4.5 parts of wetting and dispersing agent, 2.2 parts of filler 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 the aliphatic dicarboxylic acid is a combination of diethanolamine dodecenylsuccinate, diethanolamine sebacate 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 comprises the following steps, in parts by mass: S1: adding 10.5 parts of phenyl silicone resin to a reaction vessel, and adding a mixed solution of toluene and deionized water (240 parts in total), then adding 0.1 part of γ-aminopropyltriethoxysilane and heating to 75°C and keeping the reaction for 2.5 hours; S2: adding 8.5 parts of acrylamide and stirring at 80 rpm for 25 minutes until uniform, continuing to heat to 90°C, adding 0.13 part of diisopropyl peroxide, and then dropwise adding 2.8 parts of styrene, 0.1 part of a mixture of dialkyl maleate and 2.2 parts of perfluoroalkyl vinyl ether, and keeping the reaction for 4.5 hours; S3: after the reaction is completed, continue to add 0.2 part of hexamethoxymethylmelamine, and then continue to keep the reaction for 6 hours. After completion, the product is filtered and washed with toluene and deionized water, and then dried for use.

[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 comprises the following steps, in parts by mass: S1: adding 10.5 parts of phenyl silicone resin to a reaction vessel, and adding a mixed solution of toluene and deionized water (240 parts in total), then adding 0.6 parts of γ-aminopropyltriethoxysilane and heating to 75°C and keeping the 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 dialkyl maleate and 0.2 parts of perfluoroalkyl vinyl ether, and keeping the reaction for 4.5 hours; S3: after the reaction is completed, continuing to add 0.85 parts of hexamethoxymethylmelamine, and then continuing to keep the reaction for 6 hours. After completion, the product is filtered and washed with toluene and deionized water, and then dried for use.

[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 a relative humidity of 75±2% for aging resistance testing. 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 examples and comparative examples were tested for moisture permeation resistance according to GB / T 1037-2021. The test values ​​were recorded in Table 1 as the average of 10 tests.

[0087] Salt spray corrosion resistance test: The cured anti-corrosion 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 spray rate of 2mL / 16h·80cm 2 The salt spray corrosion resistance test time is 800h. After the test is completed, observe whether there is corrosion damage, yellowing, cracking or blistering. If so, 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 within the coating system after its 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 in high temperature and high humidity environments, and the migration and collision of internal molecules are serious, which greatly reduces the coating's barrier effect on moisture and the effect of preventing internal side reactions, and thus has worse aging resistance, high temperature resistance and corrosion resistance.

Claims

1. A high molecular weight anti-corrosion material that improves the quality of hot rolling mill strip steel, characterized by: The raw materials are as follows, 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 filler particles, and 30-50 parts of deionized water; The amino alcohol salt of the aliphatic dicarboxylic acid is a composition of diethanolamine dodecenylsuccinate, diethanolamine sebacate and diethanolamine azelaic acid, with a mass ratio of (50-60): (3-5): (2-4); The corrosion inhibitor is a combination of sodium phytate and sodium molybdate in a mass ratio of (4-5): (0.6-1); The plasticizer is a composition of glycerol and dioctyl phthalate, with a mass ratio of (6-8): (1-1.5); The wetting and dispersing agent is a composition of octylphenol polyoxyethylene ether, diisopropyl phosphate and epoxy block polyether, with a mass ratio of (6-7): (1-1.5): (2.5-3.5); The filling particles are a combination of silica microspheres, titanium dioxide and sericite powder; 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. and keeping the temperature for 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 dicumyl peroxide, and then dropwise adding styrene, a mixture of dialkyl maleate and perfluoroalkyl vinyl ether, and keeping the temperature for reaction for 4-5 hours; S3: after the reaction is completed, continuing to add hexamethoxymethylmelamine, and then continuing to keep the temperature for reaction for 6-8 hours. After completion, the product is filtered and washed with toluene and deionized water, and then dried for use. The mass ratio of the phenyl silicone resin, γ-aminopropyltriethoxysilane and acrylamide is (10-12): (0.5-0.8): (3.5-4.5); 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).

2. The polymer heavy-duty anti-corrosion material for improving the quality of hot rolling mill strip according to claim 1, 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).

3. The polymer heavy-duty anti-corrosion material for improving the quality of hot rolling mill strip according to claim 2, characterized in that: The HLB value of the octylphenol polyoxyethylene ether is 8-14.

4. The polymer heavy-duty anti-corrosion material for improving the quality of hot rolling mill strip according to claim 3, 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 %.

5. The polymer heavy-duty anti-corrosion material for improving the quality of hot rolling mill strip according to claim 4, characterized in that: The mass ratio of the silica microspheres, titanium dioxide and sericite powder is (5-6): (0.3-0.5): (3-3.5).

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

7. 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 6, characterized in that: The specific steps include: S1: Add the modified polysiloxane into a stirring kettle and slowly stir at 60-80 rpm at 25-35°C for 40-60 minutes. 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, filler 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 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.

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