A kind of water-based anticorrosive heat-insulating paint and preparation method thereof

Abstract

The present invention provides a kind of water-based anticorrosion and heat-insulating paint and preparation method thereof, belong to the field of coating technology, comprise the following steps: S1, after corn starch is heat-treated, mix uniformly with magnesium nitrate hexahydrate and water, cool, age, dry, calcine, obtain the anticorrosion and heat-insulating filler containing porous magnesium oxide;S2, surface-treat methyl MQ silicone resin with sodium lauryl sulfate and N ethyl toluene sulfonamide, obtain pre-treated methyl MQ silicone resin solution;After N hydroxytyrosol, N ethyl toluene sulfonamide and aqueous acrylic emulsion are mixed uniformly, add pre-treated methyl MQ silicone resin solution, mix uniformly, obtain water-based paint base material;S3, by water, other auxiliary agents, anticorrosion and heat-insulating filler and water-based paint base material, mix uniformly, obtain water-based anticorrosion and heat-insulating paint. The technical scheme provided by the present invention can not only achieve excellent anticorrosion and heat-insulating performance, but also improve the durability and rapid curing property of water-based paint.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and in particular relates to a water-based anti-corrosion and heat-insulating paint and a preparation method thereof. Background Art

[0002] Although water-based paint has the advantages of environmental protection, low volatile organic compound (VOC) emissions and good construction performance, it still has certain limitations in terms of anti-corrosion and heat insulation performance.

[0003] First, the film-forming substance of water-based paint is typically an emulsion polymer, which has relatively weak water and corrosion resistance and is easily eroded by moisture and chemical media, leading to coating failure. Second, the film thickness of water-based paint is relatively thin, making it difficult to form an effective thermal insulation layer, thus limiting the insulation effect in high-temperature environments. In addition, the moisture in water-based paint may cause the substrate to absorb water, swell, or corrode during the drying process, especially in humid environments, which further affects the adhesion and durability of the coating.

[0004] The Chinese patent document with the authorization announcement number CN115710456B, entitled "A Waterborne Functional Coating and Its Preparation Method," discloses a waterborne functional coating and its preparation method, which comprises a waterborne primer and a waterborne topcoat, wherein the volume ratio of the waterborne primer and the waterborne topcoat is 1:1; the waterborne primer comprises an epoxy resin and a primer additive; the percentages of the epoxy resin and the primer additive in the total weight of the waterborne primer are 50% to 70% and 30% to 40% respectively; the waterborne topcoat comprises acrylic polyurethane, modified silica aerogel microspheres, halloysite nanotubes, and the topcoat additive; the percentages of the epoxy resin and the primer additive in the total weight of the waterborne topcoat are 50% to 70% and 30% to 40% respectively. The composition is as follows: 0.5%~1.5% silica aerogel microspheres, 0.5%~12% polar modifier, 0.5%~1.5% halloysite nanotubes, 50%~60% acrylic polyurethane, 10%~15% topcoat curing agent, 15%~18% diluent, and 0.5%~1.5% other additives; the water-based functional coating prepared by the above technical solution can form a 200-micron-thick coating after curing at room temperature. The thermal conductivity coefficient can reach below 2W / (m·K), and its salt spray resistance and electrochemical resistance are good. It is very suitable for long-term use in marine environments and has excellent heat insulation, vibration reduction and long-term anti-corrosion properties. However, this double-layer coating system may have some functional defects. First of all, since the primer and topcoat need to be applied separately, the complexity and time cost of construction are increased, and the risk of delamination is also increased, especially when the coatings are not fully cured or the interface adhesion is insufficient. Secondly, in order to achieve the required performance, too many components need to be added, which will also cause phase separation problems, affect the physical properties of the material, and increase the material cost.

[0005] Therefore, it is necessary to provide a water-based anti-corrosion and thermal insulation paint and a preparation method thereof to solve the problems existing in the above-mentioned prior art. Summary of the Invention

[0006] In view of this, the present invention provides a water-based anti-corrosion and heat-insulating paint and a preparation method thereof, which effectively improves the anti-corrosion and heat-insulating properties of the water-based paint by preparing a filler with high anti-corrosion and heat-insulating properties and adopts an organic cross-linking method, and has good overall compatibility.

[0007] To achieve the above object, the present invention provides a method for preparing a water-based anti-corrosion and thermal insulation paint, comprising the following steps:

[0008] S1. Heat-treating corn starch, uniformly mixing it with magnesium nitrate hexahydrate and water, cooling, aging, drying, and calcining to obtain an anti-corrosion and heat-insulating filler containing porous magnesium oxide;

[0009] S2, surface treating the methyl MQ silicone resin with sodium lauryl sulfate and N-ethyl-p-toluenesulfonamide to obtain a pretreated methyl MQ silicone resin solution;

[0010] After N-hydroxytyrosol, N-ethyl p-toluenesulfonamide and water-based acrylic emulsion are mixed evenly, the pre-treated methyl MQ silicone resin solution is added and mixed evenly to obtain a water-based paint base;

[0011] S3. Evenly mix water, other additives, the anti-corrosion and heat-insulating filler prepared in step S1, and the water-based paint base prepared in step S2 to obtain a water-based anti-corrosion and heat-insulating paint.

[0012] The present invention functionally modifies the filler and base material of a water-based paint to obtain an anti-corrosion and heat-insulating filler and a water-based paint base material, and with the action of other additives, prepares a water-based anti-corrosion and heat-insulating paint with excellent anti-corrosion and heat-insulating properties. The anti-corrosion and heat-insulating filler is prepared by heat-treating corn starch and magnesium nitrate hexahydrate and calcining them at high temperature to construct porous magnesium oxide with excellent chemical resistance and low thermal conductivity. The base material is prepared by cross-linking and modifying a hydrophobic methyl MQ silicone resin with a unique stable structure and a hydrophilic water-based acrylic emulsion, and forming a stable system under the action of sodium lauryl sulfate, N-ethyl-p-toluenesulfonamide, and N-hydroxytyrosol.

[0013] The present invention prepares porous magnesium oxide as an anti-corrosion and heat-insulating filler for water-based paint. First, the surface of corn starch particles contains many active groups, such as hydroxyl groups, so that the particle surface is negatively charged. During the soaking process, the ionized Mg 2+ and hydroxyl groups are adsorbed on the surface of corn starch particles under the action of electrostatic effect and coordination bond. As the temperature increases during the drying process, Mg 2+A hydrolysis reaction occurs, producing solid magnesium nitrate, which crystallizes on the surface of the corn starch. After high-temperature calcination, the basic magnesium nitrate crystal nuclei gradually increase in size and decompose to produce magnesium oxide. Simultaneously, the corn starch granules act as embedded templates, decomposing to produce CO2 and forming a macroporous structure. This porous structure helps increase the specific surface area of ​​the magnesium oxide, thereby reducing the heat transfer path and improving the thermal insulation effect. Furthermore, the air or other gases in the pores have excellent thermal insulation properties, effectively preventing heat conduction, helping to reduce thermal conductivity and improve thermal insulation performance. Secondly, magnesium oxide is highly stable in air and does not easily react with moisture or other chemicals. Therefore, it can effectively protect the coating from erosion by moisture, acidic substances, or corrosive gases in the external environment.

[0014] In order to further improve the anti-corrosion and heat-insulating properties of water-based paint and the compatibility between each component, the present invention also prepares a base material with excellent anti-corrosion properties and curing speed. First, sodium lauryl sulfate and N-ethyl toluene sulfonamide are used to improve the dispersibility of methyl MQ silicone resin in water. By introducing sulfonic acid groups and amide groups to interact with the methyl MQ silicone resin, the methyl MQ silicone resin is given a certain hydrophilicity. In addition, sodium lauryl sulfate, as a surfactant, can interact with resin molecules in aqueous solution through its hydrophobic alkyl chain, helping the resin to be dispersed in water, and then more conducive to increasing its compatibility with aqueous acrylic emulsion. Secondly, N-hydroxytyrosol can form hydrogen bonds with the carboxyl groups in the aqueous acrylic emulsion, enhancing the stability of the emulsion. It also improves the compatibility between the various components of the water-based paint through surface hydrogen bonding with the polar groups in the pre-treated methyl MQ silicone resin solution and N-ethyl toluene sulfonamide, thereby forming a stable water-based paint system. In addition, the thermal stability and chemical resistance of the methyl MQ silicone resin itself also further enhance the overall anti-corrosion effect. At the same time, hydrophilic, hydrophobic interactions and hydrogen bonds also help to form a cross-linked structure, increase the overall cross-linking density, and further accelerate the curing speed of water-based paint.

[0015] In summary, the present invention effectively improves the anti-corrosion and heat-insulating properties of water-based paint through the construction and organic cross-linking modification of porous magnesium oxide, while also demonstrating its unique advantages in cost control and environmental protection, meeting the requirements of environmental protection and cost-effectiveness.

[0016] Optionally, in step S1, the corn starch is washed with anhydrous ethanol and heat-treated to obtain heat-treated corn starch, and then magnesium nitrate hexahydrate is dispersed in deionized water, and the heat-treated corn starch is added, mixed evenly, heated and stirred until it becomes a sol, cooled, aged, and dried to obtain a gel-like solid, and finally calcined under vacuum, and taken out after natural cooling to obtain an anti-corrosion and heat-insulating filler containing porous magnesium oxide.

[0017] In the preparation process of the anti-corrosion and heat-insulating filler of the present invention, corn starch is first washed with anhydrous ethanol to effectively remove protein and fat in the corn starch, and then dried at 60°C, which helps to effectively remove moisture without destroying the structure of the corn starch, thereby obtaining pure corn starch.

[0018] Optionally, the heat treatment temperature is 50~60℃, the rotation speed is 400~500r / min, and the time is 2~3h; the mass ratio of the corn starch and magnesium nitrate hexahydrate after the heat treatment is 2:1; the heating and stirring temperature is 80~90℃, the rotation speed is 300~400r / min, and the time is 2~3h; the aging time is 24~36h; the drying temperature is 110~120℃, and the time is 12~20h; the calcination temperature is 950~1050℃, and the time is 2~3h; the natural cooling temperature is 70~80℃.

[0019] The present invention uses a mass ratio of 2:1 between heat-treated corn starch and magnesium nitrate hexahydrate, which has a better effect on the porous magnesium oxide formed after dispersion into a gel. A higher or lower ratio of heat-treated corn starch to magnesium nitrate hexahydrate affects the size and density of the resulting pore structure.

[0020] Optionally, in step S2, sodium lauryl sulfate, N-ethyl-p-toluenesulfonamide and methyl MQ silicone resin are dispersed in deionized water to obtain a pretreated methyl MQ silicone resin solution, and then N-hydroxytyrosol is dispersed in deionized water, an aqueous acrylic emulsion is added, and the mixture is stirred evenly. N-ethyl-p-toluenesulfonamide is added and the mixture is mixed evenly to obtain a pretreated aqueous acrylic emulsion, and the pretreated methyl MQ silicone resin solution is then added and mixed evenly to obtain a water-based paint base.

[0021] When treating methyl MQ silicone resin, the present invention simultaneously adds N-ethyl-p-toluenesulfonamide and sodium lauryl sulfate. This is primarily because N-ethyl-p-toluenesulfonamide and sodium lauryl sulfate work together in the process, helping to improve the dispersibility of the silicone resin in water and produce a good crosslinking effect. When treating an aqueous acrylic emulsion, N-hydroxytyrosol is added first, followed by N-ethyl-p-toluenesulfonamide. This is primarily because N-hydroxytyrosol can act as an initiator to promote the onset of the crosslinking reaction. The subsequent addition of N-ethyl-p-toluenesulfonamide further improves the crosslinking efficiency and system performance. This sequence helps ensure the uniformity and effectiveness of the reactions, thereby optimizing the properties of the material.

[0022] Optionally, the speed of dispersing, mixing and stirring is 400-600 r / min, and the time is 1-2 h; the mass ratio of sodium lauryl sulfate, N-ethyl toluenesulfonamide and methyl MQ silicone resin is 1:1:5; the mass ratio of N-hydroxytyrosol, N-ethyl toluenesulfonamide and aqueous acrylic emulsion is 1:1:62.

[0023] Optionally, the other additives in S3 are wetting agent LCN407, defoaming agent 204, dispersant NNO and film-forming aid; the film-forming aid is dipropylene glycol butyl ether.

[0024] Optionally, in step S3, deionized water, wetting agent LCN407, dispersant NNO, defoaming agent 204 and the water-based paint base prepared by S2 are stirred evenly, the anti-corrosion and heat-insulating filler prepared by S1 is added and stirred evenly, a film-forming aid is added during stirring, and the material is filtered to obtain a water-based anti-corrosion and heat-insulating paint.

[0025] The order of adding fillers and base materials in this process optimizes mixing and dispersion. Mixing the base material with the wetting agent, dispersant, and defoamer helps create a uniform medium, reducing bubbles and improving wettability. Adding the filler, then, prevents filler aggregation and ensures uniform distribution, thereby improving the paint's performance and stability. Adding the film-forming aid during stirring ensures its full reaction with the other ingredients, enhancing film formation quality. Finally, filtering removes undispersed particles, ensuring paint uniformity and performance.

[0026] Optionally, the mass ratio of the anti-corrosion and heat-insulating filler prepared by S1 to the water-based paint base prepared by S2 is (5~15):(65~75); the stirring speed of the water-based paint base and other additives is 500~600r / min, and the time is 3~5h; the stirring speed when adding the anti-corrosion and heat-insulating filler prepared by S1 is 500~600r / min, and the time is 7~9h.

[0027] In order to achieve the above-mentioned purpose, the present invention also provides a water-based anti-corrosion and heat-insulating paint prepared by the preparation method of the above-mentioned water-based anti-corrosion and heat-insulating paint, comprising the following raw materials in parts by mass: 20 parts of deionized water, 3 to 5 parts of other additives, 30 to 46 parts of heat-treated corn starch, 15 to 23 parts of magnesium nitrate hexahydrate, 0.5 part of sodium lauryl sulfate, 1 part of N-ethyl p-toluenesulfonamide, 2 to 4 parts of methyl MQ silicone resin, 0.5 part of N-hydroxytyrosol, and 25 to 31 parts of water-based acrylic emulsion.

[0028] Optionally, the other additives include 0.3 parts of wetting agent LCN407, 0.4 parts of dispersant NNO, 0.3 parts of defoaming agent 204 and 2-4 parts of dipropylene glycol butyl ether.

[0029] The water-based anti-corrosion and heat-insulating paint obtained by the invention can improve the anti-corrosion and heat-insulating performance while also improving the rapid curing property and durability of the water-based paint.

[0030] The above technical solution of the present invention includes at least the following beneficial effects:

[0031] 1. The present invention uses corn starch as a template, mixes it with magnesium nitrate hexahydrate under mild conditions, and then undergoes heat treatment and high-temperature calcination to form porous magnesium oxide with high corrosion resistance and low thermal conductivity. The preparation process is also simple. The subsequent calcination and cooling temperature control allows a certain number of hydroxyl groups to form on the product surface, which helps enhance compatibility and reactivity with the polymer matrix and reduces the amount of filler added.

[0032] 2. The present invention also uses hydrophobic methyl MQ silicone resin and hydrophilic aqueous acrylic emulsion for cross-linking modification, and adds two food-grade additives, N-hydroxytyrosol and N-ethyl p-toluenesulfonamide, as auxiliary agents, which helps to significantly improve the compatibility and cross-linking density between the components and accelerate the curing process of the water-based paint.

[0033] 3. The corn starch, magnesium nitrate hexahydrate, methyl MQ silicone resin, N-hydroxytyrosol, N-ethyl-p-toluenesulfonamide and aqueous acrylic emulsion used in the present invention are all non-toxic and harmless materials, and have certain environmental friendliness. The preparation process is streamlined, which helps to reduce the generation of chemical components and pollutants. At the same time, the material cost used in the present invention is low, which helps to improve the cost and environmental advantages of the system, making it more economical and stable in coating applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 and Figure 2 The SEM image of the prepared porous magnesium oxide. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0036] The wetting agent LCN407 used in the following examples was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd.; the dispersant NNO was purchased from Shanghai Maclean Biochemical Co., Ltd.; the defoaming agent 204 was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; and the film-forming aid dipropylene glycol butyl ether was purchased from Shanghai Maclean Biochemical Co., Ltd.

[0037] Example 1

[0038] Preparation of anti-corrosion and thermal insulation filler: Corn starch is washed twice with anhydrous ethanol and dried at 60°C to obtain pretreated corn starch. 15 parts of magnesium nitrate hexahydrate are added to 450 parts of deionized water and dispersed at a speed of 500 r / min for 2 hours. Then, 30 parts of pretreated corn starch are added in two portions and stirred at a speed of 400 r / min for 3 hours to obtain a suspension. The suspension is reacted at 90°C and a speed of 400 r / min for 2 hours, cooled to room temperature, aged for 24 hours, and dried at 120°C for 12 hours to obtain a gel-like solid. The gel-like solid is calcined at 1050°C in a tube furnace under vacuum for 2 hours. After it is naturally cooled to 80°C, a porous magnesium oxide anti-corrosion and thermal insulation filler is obtained.

[0039] Preparation of water-based paint binder: Add 0.5 parts of sodium lauryl sulfate, 0.5 parts of N-ethyl-p-toluenesulfonamide, and 2 parts of methyl MQ silicone resin to 10 parts of deionized water and disperse at 600 r / min for 1 hour to obtain a pretreated methyl MQ silicone resin solution. Add 0.5 parts of N-hydroxytyrosol to 50 parts of deionized water and disperse at 600 r / min for 1 hour. Add 25 parts of aqueous acrylic emulsion and stir at 600 r / min for 1 hour. Add 0.5 parts of N-ethyl-p-toluenesulfonamide and stir at 600 r / min for 1 hour. Then add the pretreated methyl MQ silicone resin solution and stir at 600 r / min for 1 hour to obtain the water-based paint binder.

[0040] Preparation of water-based anti-corrosion and thermal insulation paint: 75 parts of base material, 0.3 parts of wetting agent LCN407, 0.4 parts of dispersant NNO, 0.3 parts of defoaming agent 204 and 20 parts of deionized water are stirred at a speed of 600 r / min for 3 hours, 5 parts of anti-corrosion and thermal insulation filler are added, and stirred at a speed of 500 r / min for 7 hours. During the stirring period, 2 parts of film-forming aid are added, and the material is filtered to obtain water-based anti-corrosion and thermal insulation paint.

[0041] Example 2

[0042] Preparation of anti-corrosion and thermal insulation filler: Corn starch was washed three times with anhydrous ethanol and dried at 60°C to obtain pretreated corn starch. 15 parts of magnesium nitrate hexahydrate were added to 450 parts of deionized water and dispersed at a speed of 500 r / min for 2 hours. Then, 30 parts of pretreated corn starch were added in two portions and stirred at a speed of 400 r / min for 3 hours to obtain a suspension. The suspension was reacted at 90°C and a speed of 400 r / min for 2 hours, cooled to room temperature, aged for 24 hours, and dried at 120°C for 12 hours to obtain a gel-like solid. The gel-like solid was calcined at 1050°C in a tube furnace under vacuum for 2 hours. After it was naturally cooled to 80°C, a porous magnesium oxide anti-corrosion and thermal insulation filler was obtained.

[0043] Preparation of water-based paint binder: Add 0.5 parts of sodium lauryl sulfate, 0.5 parts of N-ethyl-p-toluenesulfonamide, and 2.5 parts of methyl MQ silicone resin to 10 parts of deionized water and disperse at 400 r / min for 2 hours to obtain a pretreated methyl MQ silicone resin solution. Add 0.5 parts of N-hydroxytyrosol to 50 parts of deionized water and disperse at 400 r / min for 2 hours. Add 31 parts of aqueous acrylic emulsion and stir at 400 r / min for 2 hours. Add 0.5 parts of N-ethyl-p-toluenesulfonamide and stir at 400 r / min for 2 hours. Then add the pretreated methyl MQ silicone resin solution and stir at 400 r / min for 2 hours to obtain the water-based paint binder.

[0044] Preparation of water-based anti-corrosion and thermal insulation paint: 73 parts of base material, 0.3 parts of wetting agent LCN407, 0.4 parts of dispersant NNO, 0.3 parts of defoaming agent 204 and 20 parts of deionized water are stirred at a speed of 600 r / min for 3 hours, 7 parts of anti-corrosion and thermal insulation filler are added, and stirred at a speed of 600 r / min for 8 hours. During the stirring period, 3 parts of film-forming aid are added, and the material is filtered to obtain water-based anti-corrosion and thermal insulation paint.

[0045] Example 3

[0046] Preparation of anti-corrosion and thermal insulation filler: Corn starch is washed twice with anhydrous ethanol and dried at 60°C to obtain pretreated corn starch. 15 parts of magnesium nitrate hexahydrate are added to 450 parts of deionized water and dispersed at a speed of 500 r / min for 2 hours. Then, 30 parts of pretreated corn starch are added in two portions and stirred at a speed of 400 r / min for 3 hours to obtain a suspension. The suspension is reacted at 90°C and a speed of 400 r / min for 2 hours, cooled to room temperature, aged for 24 hours, and dried at 120°C for 12 hours to obtain a gel-like solid. The gel-like solid is calcined at 1050°C in a tube furnace under vacuum for 2 hours. After it is naturally cooled to 80°C, a porous magnesium oxide anti-corrosion and thermal insulation filler is obtained.

[0047] Preparation of water-based paint binder: Add 0.5 parts of sodium lauryl sulfate, 0.5 parts of N-ethyl-p-toluenesulfonamide, and 2.5 parts of methyl MQ silicone resin to 10 parts of deionized water and disperse at 400 r / min for 2 hours to obtain a pretreated methyl MQ silicone resin solution. Add 0.5 parts of N-hydroxytyrosol to 50 parts of deionized water and disperse at 400 r / min for 2 hours. Add 31 parts of aqueous acrylic emulsion and stir at 400 r / min for 2 hours. Add 0.5 parts of N-ethyl-p-toluenesulfonamide and stir at 400 r / min for 2 hours. Then add the pretreated methyl MQ silicone resin solution and stir at 400 r / min for 2 hours to obtain the water-based paint binder.

[0048] Preparation of water-based anti-corrosion and thermal insulation paint: 72 parts of base material, 0.3 parts of wetting agent LCN407, 0.4 parts of dispersant NNO, 0.3 parts of defoaming agent 204 and 20 parts of deionized water are stirred at a speed of 500 r / min for 3.5 hours, 8 parts of anti-corrosion and thermal insulation filler are added, and the mixture is stirred at a speed of 500 r / min for 8 hours. During the stirring period, 2 parts of film-forming aid are added, and the material is filtered to obtain water-based anti-corrosion and thermal insulation paint.

[0049] Example 4

[0050] Preparation of anti-corrosion and thermal insulation filler: Corn starch was washed three times with anhydrous ethanol and dried at 60°C to obtain pretreated corn starch. 15 parts of magnesium nitrate hexahydrate were added to 450 parts of deionized water and dispersed at a speed of 500 r / min for 2 hours. Then, 30 parts of pretreated corn starch were added in two portions and stirred at a speed of 400 r / min for 3 hours to obtain a suspension. The suspension was reacted at 90°C and a speed of 400 r / min for 2 hours, cooled to room temperature, aged for 24 hours, and dried at 120°C for 12 hours to obtain a gel-like solid. The gel-like solid was calcined at 1050°C in a tube furnace under vacuum for 2 hours. After it was naturally cooled to 80°C, a porous magnesium oxide anti-corrosion and thermal insulation filler was obtained.

[0051] Preparation of water-based paint binder: Add 0.5 parts of sodium lauryl sulfate, 0.5 parts of N-ethyl-p-toluenesulfonamide, and 2.5 parts of methyl MQ silicone resin to 10 parts of deionized water and disperse at 400 r / min for 2 hours to obtain a pretreated methyl MQ silicone resin solution. Add 0.5 parts of N-hydroxytyrosol to 50 parts of deionized water and disperse at 400 r / min for 2 hours. Add 31 parts of aqueous acrylic emulsion and stir at 400 r / min for 2 hours. Add 0.5 parts of N-ethyl-p-toluenesulfonamide and stir at 400 r / min for 2 hours. Then add the pretreated methyl MQ silicone resin solution and stir at 400 r / min for 2 hours to obtain the water-based paint binder.

[0052] Preparation of water-based anti-corrosion and thermal insulation paint: 70 parts of base material, 0.3 parts of wetting agent LCN407, 0.4 parts of dispersant NNO, 0.3 parts of defoaming agent 204 and 20 parts of deionized water are stirred at a speed of 600 r / min for 4 hours, 10 parts of anti-corrosion and thermal insulation filler are added, and stirred at a speed of 600 r / min for 8 hours. During the stirring period, 4 parts of film-forming aid are added, and the material is filtered to obtain water-based anti-corrosion and thermal insulation paint.

[0053] Example 5

[0054] Preparation of thermal insulation and anti-corrosion filler: Corn starch was washed three times with anhydrous ethanol and dried at 60°C to obtain pretreated corn starch. 23 parts of magnesium nitrate hexahydrate were added to 700 parts of deionized water and dispersed at a speed of 400 r / min for 3 hours. Then 46 parts of pretreated corn starch were added in three portions and stirred at a speed of 400 r / min for 4 hours to obtain a suspension. The suspension was reacted at 80°C and 300 r / min for 3 hours, cooled to room temperature, aged for 36 hours, and dried at 110°C for 20 hours to obtain a gel-like solid. The gel-like solid was calcined at 950°C in a tube furnace under vacuum for 3 hours. After it was naturally cooled to 70°C, a porous magnesium oxide anti-corrosion and thermal insulation filler was obtained.

[0055] Preparation of water-based paint binder: Add 0.5 parts of sodium lauryl sulfate, 0.5 parts of N-ethyl-p-toluenesulfonamide, and 2.5 parts of methyl MQ silicone resin to 10 parts of deionized water and disperse at 400 r / min for 2 hours to obtain a pretreated methyl MQ silicone resin solution. Add 0.5 parts of N-hydroxytyrosol to 50 parts of deionized water and disperse at 400 r / min for 2 hours. Add 31 parts of aqueous acrylic emulsion and stir at 400 r / min for 2 hours. Add 0.5 parts of N-ethyl-p-toluenesulfonamide and stir at 400 r / min for 2 hours. Then add the pretreated methyl MQ silicone resin solution and stir at 400 r / min for 2 hours to obtain the water-based paint binder.

[0056] Preparation of water-based anti-corrosion and thermal insulation paint: 68 parts of base material, 0.3 parts of wetting agent LCN407, 0.4 parts of dispersant NNO, 0.3 parts of defoaming agent 204 and 20 parts of deionized water are stirred at a speed of 600 r / min for 3 hours, 12 parts of anti-corrosion and thermal insulation filler are added, and stirred at a speed of 600 r / min for 7 hours. During the stirring period, 2 parts of film-forming aid are added, and the material is filtered to obtain water-based anti-corrosion and thermal insulation paint.

[0057] Example 6

[0058] Preparation of thermal insulation and anti-corrosion filler: Corn starch was washed three times with anhydrous ethanol and dried at 60°C to obtain pretreated corn starch. 23 parts of magnesium nitrate hexahydrate were added to 700 parts of deionized water and dispersed at a speed of 400 r / min for 3 hours. Then 46 parts of pretreated corn starch were added in three portions and stirred at a speed of 400 r / min for 4 hours to obtain a suspension. The suspension was reacted at 80°C and 300 r / min for 3 hours, cooled to room temperature, aged for 36 hours, and dried at 110°C for 20 hours to obtain a gel-like solid. The gel-like solid was calcined at 950°C in a tube furnace under vacuum for 3 hours. After it was naturally cooled to 70°C, a porous magnesium oxide anti-corrosion and thermal insulation filler was obtained.

[0059] Preparation of water-based paint binder: Add 0.5 parts of sodium lauryl sulfate, 0.5 parts of N-ethyl-p-toluenesulfonamide, and 4 parts of methyl MQ silicone resin to 10 parts of deionized water and disperse at 400 r / min for 2 hours to obtain a pretreated methyl MQ silicone resin solution. Add 0.5 parts of N-hydroxytyrosol to 50 parts of deionized water and disperse at 400 r / min for 2 hours. Add 31 parts of aqueous acrylic emulsion and stir at 400 r / min for 2 hours. Add 0.5 parts of N-ethyl-p-toluenesulfonamide and stir at 400 r / min for 2 hours. Then add the pretreated methyl MQ silicone resin solution and stir at 400 r / min for 2 hours to obtain the water-based paint binder.

[0060] Preparation of water-based anti-corrosion and thermal insulation paint: 65 parts of base material, 0.3 parts of wetting agent LCN407, 0.4 parts of dispersant NNO, 0.3 parts of defoaming agent 204 and 20 parts of deionized water are stirred at a speed of 500 r / min for 5 hours, 15 parts of anti-corrosion and thermal insulation filler are added, and stirred at a speed of 500 r / min for 9 hours. During the stirring period, 3 parts of film-forming aid are added, and the material is filtered to obtain water-based anti-corrosion and thermal insulation paint.

[0061] The present invention also provides comparative examples and related experiments.

[0062] Comparative Example 1

[0063] The difference between Comparative Example 1 and Example 4 is that the anti-corrosion and heat-insulating filler is not the porous magnesium oxide prepared in Example 1, but commercially available spherical magnesium oxide. The other compositions and preparation methods are the same as those in Example 4, and finally a water-based anti-corrosion and heat-insulating paint is prepared.

[0064] Comparative Example 2

[0065] The difference between Comparative Example 2 and Example 4 is that 5 parts of methyl MQ silicone resin were not added, and 5 parts of methyl MQ silicone resin were replaced by 5 parts of water-based acrylic emulsion. The other components and preparation methods were the same as those of Example 4, and a water-based anticorrosive and heat-insulating paint was finally prepared.

[0066] Comparative Example 3

[0067] The difference between Comparative Example 3 and Example 4 is that 0.5 parts of N-hydroxytyrosol is not added, and 0.5 parts of N-ethyl-p-toluenesulfonamide is used instead. The other components and preparation methods are the same as those of Example 4, and a water-based anticorrosive heat-insulating paint is finally prepared.

[0068] Comparative Example 4

[0069] The difference between Comparative Example 4 and Example 4 is that 1 part of N-ethyl-p-toluenesulfonamide is not added, and 1 part of N-ethyl-p-toluenesulfonamide is replaced by 1 part of N-hydroxytyrosol. The other compositions and preparation methods are the same as those of Example 4, and a water-based anticorrosive and heat-insulating paint is finally prepared.

[0070] The water-based anticorrosive and thermal insulation paints of Examples 1 to 6 and Comparative Examples 1 to 4 were subjected to relevant performance tests according to the test standards and performance indicators in Table 1. The test data are shown in Tables 2 and 3. The porous magnesium oxide prepared in Example 1 was characterized by SEM morphology. The results are shown in Tables 2 and 3. Figure 1 and Figure 2 shown.

[0071] Table 1

[0072]

[0073] Table 2

[0074]

[0075] It can be seen from Tables 1 and 2 that the corrosion resistance, durability and curing speed of the water-based anti-corrosion and thermal insulation paints prepared in Examples 1 to 6 are significantly higher than those prepared in Comparative Examples 1 to 4, and Example 4 has the best performance and is the optimal solution of the present invention.

[0076] Combining the data in Table 1 and Table 2, by comparing Example 4 with Comparative Examples 1 to 4, it can be seen that the test data of Comparative Examples 1 and 2 in Table 2 do not meet the performance indicators of Table 1. It can be seen that the addition of porous magnesium oxide, methyl MQ silicone resin, N-hydroxytyrosol and N-ethyl-p-toluenesulfonamide has a certain degree of influence on the corrosion resistance, durability and curing speed of water-based paint.

[0077] According to the test result of impact resistance, water resistance, acid resistance and alkali resistance of comparative example 1,2 and embodiment 4, and in conjunction with table 1 performance index, it can be seen that when porous magnesium oxide and methyl MQ silicone resin are not added, crackle and faint deformation can occur in water-based paint under 50cm positive and negative impact, and bubbling, the phenomenon of cracking can occur in 120 hours, it can be seen that the impact of porous magnesium oxide and methyl MQ silicone resin on the anticorrosive property of water-based paint is larger.And the anticorrosive property test data of comparative example 3 meets table 1 performance index substantially, comparative example 4 also meets table 1 performance index substantially except impact resistance, it is known that the adding of N-ethyl toluene sulfonamide has less impact on the anticorrosive property of water-based paint, and the adding of N-hydroxytyrosol does not have substantially impact on the anticorrosive property of water-based paint.

[0078] According to the test results of impact resistance, water resistance, artificial aging resistance, acid resistance and alkali resistance of Comparative Examples 1 to 4 and Example 4, and combined with the performance indicators in Table 1, it can be seen that the test data of Comparative Examples 1 and 2 in Table 2 do not meet the performance indicators in Table 1, Comparative Example 3 basically meets the performance indicators in Table 1 except for artificial aging resistance, and Comparative Example 4 also basically meets the performance indicators in Table 1 except for impact resistance. It can be seen that porous magnesium oxide filler and methyl MQ silicone resin have a greater effect on the durability of water-based paint, while the addition of N-ethyl toluenesulfonamide and N-hydroxytyrosol has less effect on the durability of water-based paint.

[0079] According to the test results of the surface drying and actual drying of Comparative Examples 1 to 4 and Example 4, and in combination with the performance indicators in Table 1, it can be seen that the test data of Comparative Examples 1 to 4 do not meet the performance indicators in Table 1, and the surface drying and actual drying data in Comparative Example 4 differ the most from the data in Example 4, which are 3.0 and 32 hours, which are 2.5 and 12 hours different from the data in Example 4; the surface drying and actual drying data in Comparative Example 3 differ greatly from the data in Example 4, which are 2.9 and 33 hours, which are 2.4 and 13 hours different from the data in Example 4; it can be seen that the addition of N-hydroxytyrosol and N-ethyl toluenesulfonamide has a greater effect on the curing speed of the water-based paint, and the addition of porous magnesium oxide and methyl MQ silicone resin has a relatively small effect on the curing speed of the water-based paint.

[0080] Table 3

[0081]

[0082] It can be seen from Table 1 and Table 3 that the test results of the water-based anti-corrosion and thermal insulation paints prepared in Examples 1 to 6 obviously meet the performance indicators in Table 1, while the solar reflectance, near-infrared reflectance, and hemispherical reflectance of Comparative Examples 1 to 4 do not meet the performance indicators in Table 1, and except for the thermal conductivity of Comparative Example 3 which meets the performance indicators in Table 1, Comparative Examples 1, 2, and 4 do not meet the requirements. That is, the thermal insulation performance of Examples 1 to 6 is significantly higher than that of the water-based anti-corrosion and thermal insulation paints prepared in Comparative Examples 1 to 4, and Example 4 has the best performance, which is the optimal solution of the present invention.

[0083] In conjunction with the data in Table 1 and Table 3, by the test data of the solar reflectance, near-infrared reflectance, hemispherical reflectivity, thermal conductivity of Example 4 and Comparative Examples 1~4, and in conjunction with Table 1 performance index, it can be seen that the solar reflectance, near-infrared reflectance, hemispherical reflectivity of Comparative Examples 1~4 do not meet the performance index of Table 1, and except that the thermal conductivity of Comparative Example 3 meets the performance index of Table 1, Comparative Examples 1, 2, and 4 do not meet. It can be seen that the addition of porous magnesium oxide, methyl MQ silicone resin, N-hydroxytyrosol and N-ethyl toluenesulfonamide all has a certain degree of influence on the thermal insulation performance of water-based paint, and the addition of porous magnesium oxide and methyl MQ silicone resin is larger on the impact of water-based paint curing speed, and the addition of N-hydroxytyrosol and N-ethyl toluenesulfonamide is relatively small on the impact of the curing speed of water-based paint.

[0084] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a water-based anti-corrosion and thermal insulation paint, characterized in that: The following steps are involved: S1. Corn starch is washed with anhydrous ethanol and heat-treated to obtain heat-treated corn starch. Magnesium nitrate hexahydrate is then dispersed in deionized water. The heat-treated corn starch is then added and mixed evenly. The mixture is heated and stirred until it becomes a sol-like state. The mixture is cooled, aged, and dried to obtain a gel-like solid. The solid is then calcined under vacuum and taken out after natural cooling to obtain an anti-corrosion and heat-insulating filler containing porous magnesium oxide. S2, sodium lauryl sulfate, N-ethyl p-toluenesulfonamide and methyl MQ silicone resin are dispersed in deionized water to obtain a pre-treated methyl MQ silicone resin solution, then N-hydroxytyrosol is dispersed in deionized water, an aqueous acrylic emulsion is added, and stirred evenly, N-ethyl p-toluenesulfonamide is added, and mixed evenly to obtain a pre-treated aqueous acrylic emulsion, and then the pre-treated methyl MQ silicone resin solution is added and mixed evenly to obtain a water-based paint binder; S3. Evenly mix water, other additives, the anti-corrosion and heat-insulating filler prepared in step S1, and the water-based paint base prepared in step S2 to obtain a water-based anti-corrosion and heat-insulating paint.

2. The method for preparing a water-based anticorrosive thermal insulation paint according to claim 1, characterized in that: In step S1, the heat treatment temperature is 50-60°C, the rotation speed is 400-500 r / min, and the time is 2-3 hours; the mass ratio of the heat-treated corn starch to magnesium nitrate hexahydrate is 2:1; the heating and stirring temperature is 90-100°C, the rotation speed is 300-400 r / min, and the time is 2-3 hours; the aging time is 24-36 hours; the drying temperature is 110-120°C, and the time is 12-20 hours; the calcination temperature is 950-1050°C, and the time is 2-3 hours; and the natural cooling temperature is 70-80°C.

3. The method for preparing a water-based anticorrosive thermal insulation paint according to claim 1, characterized in that: In step S2, the speed of dispersing, mixing and stirring is 400-600 r / min, and the time is 1-2 h; the mass ratio of the sodium lauryl sulfate, N-ethyl-p-toluenesulfonamide and methyl MQ silicone resin is 1:1:5; the mass ratio of the N-hydroxytyrosol, N-ethyl-p-toluenesulfonamide and aqueous acrylic emulsion is 1:1:

62.

4. The method for preparing a water-based anticorrosive thermal insulation paint according to claim 1, characterized in that: In step S3, other additives include wetting agent LCN407, defoaming agent 204, dispersant NNO and film-forming aid; the film-forming aid is dipropylene glycol butyl ether.

5. The method for preparing a water-based anticorrosive and thermal insulation paint according to claim 1, characterized in that: In step S3, deionized water, wetting agent LCN407, dispersant NNO, defoamer 204 and the water-based paint base prepared in S2 are stirred evenly, and the anti-corrosion and heat-insulating filler prepared in S1 is added and stirred evenly. During the stirring, a film-forming aid is added, and the material is filtered to obtain a water-based anti-corrosion and heat-insulating paint.

6. The method for preparing a water-based anticorrosive and thermal insulation paint according to claim 5, characterized in that: The mass ratio of the anti-corrosion and heat-insulating filler prepared by S1 to the water-based paint base prepared by S2 is (5~15):(65~75); the stirring speed of the water-based paint base and other additives is 500~600r / min, and the time is 3~5h; the stirring speed when adding the anti-corrosion and heat-insulating filler prepared by S1 is 500~600r / min, and the time is 7~9h.

7. A water-based anti-corrosion and thermal insulation paint, characterized in that: The paint is prepared by the preparation method of a water-based anti-corrosion and thermal insulation paint according to any one of claims 1 to 6, and comprises the following raw materials in parts by mass: 20 parts of deionized water, 3 to 5 parts of other additives, 30 to 46 parts of heat-treated corn starch, 15 to 23 parts of magnesium nitrate hexahydrate, 0.5 part of sodium lauryl sulfate, 1 part of N-ethyl p-toluenesulfonamide, 2 to 4 parts of methyl MQ silicone resin, 0.5 part of N-hydroxytyrosol, and 25 to 31 parts of water-based acrylic emulsion.

8. The water-based anti-corrosion and heat-insulating paint according to claim 7, characterized in that: The other additives include 0.3 parts of wetting agent LCN407, 0.4 parts of dispersant NNO, 0.3 parts of defoaming agent 204 and 2-4 parts of dipropylene glycol butyl ether.

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