A water-resistant and anti-corrosion fireproof coating and its preparation method

Abstract

The present invention relates to a water-resistant and anti-corrosion fireproof coating and a preparation method thereof, which comprise the following components and parts by weight: 60-80 parts of an organic-inorganic hybrid resin, 20-30 parts of microencapsulated ammonium polyphosphate, 10-15 parts of a pentaerythritol / montmorillonite complex, 6-9 parts of nano-ZnFe2O4, 3-7 parts of calcium ion-modified silica microspheres, 0.3-0.6 part of a wetting agent, and 3-5 parts of propanol. A hydrophobic network is constructed by the organic-inorganic hybrid base material, nano-zinc ferrite and calcium ion-modified silica microspheres are used for synergistic anti-corrosion, and the microencapsulation technology is used to synergistically regulate the decomposition kinetics of the pentaerythritol / montmorillonite complex as a flame retardant. The product has no rust spots after being immersed in high-temperature brine for 20 days, the water contact angle is ≥86°, and the fire-resistant temperature is higher than that of commercially available products, and it is suitable for harsh environments such as ships and offshore platforms.

Description

Technical Field

[0001] The present invention relates to the technical field of fireproof coatings, and particularly to a water-resistant and anti-corrosion fireproof coating and a preparation method thereof. Background Art

[0002] At present, steel structure buildings are widely used due to their advantages such as stable structure, large space, convenient construction and recycling. However, steel structures are prone to losing stability in high-temperature environments and being corroded in humid environments. Therefore, a coating with both fireproof and anti-corrosion functions is required. Conventional resin-based materials (such as ordinary acrylic acid) have high water absorption and are prone to swelling and peeling in humid environments, resulting in the failure of the fireproof layer; some lack long-term rust-proof components, and metal substrates are prone to electrochemical corrosion in high-temperature and high-humid environments, reducing the structural strength; and adding preservatives may damage the structure of the expanded carbon layer, resulting in a decrease in fireproof efficiency. Therefore, existing fireproof coatings mostly have problems such as poor water resistance and insufficient anti-corrosion performance, and it is difficult to meet the use requirements of outdoor steel structures. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to provide a water-resistant and anti-corrosion fireproof coating and a preparation method thereof to solve the problem of mutual restriction of functional components of current fireproof coatings.

[0004] Technical Solution: A water-resistant and anti-corrosion fireproof coating, characterized in that it contains the following components and parts by weight: 60-80 parts of organic-inorganic hybrid resin, 20-30 parts of microencapsulated ammonium polyphosphate, 10-15 parts of pentaerythritol / montmorillonite composite, 6-9 parts of nano-ZnFe2O4, 3-7 parts of calcium ion-modified silica microspheres, 0.3-0.6 parts of wetting agent, and 3-5 parts of propanol.

[0005] Preferably, the preparation method of the organic-inorganic hybrid resin is as follows: Add end-hydrogen silicone oil (2H2000) to a reaction flask, add p-methoxyphenol with a weight 0.05 times that of the end-hydrogen silicone oil and a 1% chloroplatinic acid tetrahydrofuran solution with a volume 1 time that of the end-hydrogen silicone oil under stirring, add 4-vinylbenzyl glycidyl ether with a weight 0.2 times that of the end-hydrogen silicone oil, heat and reflux for 8 h, concentrate under reduced pressure at 80 °C until no liquid drips out to obtain polysiloxane epoxy resin, and mix the polysiloxane epoxy resin and silica sol (SiO2 particle size 20-40 nm) by stirring at a volume ratio of 3:1-5:1 for 30 min for compounding, thus obtaining; the infrared spectrum of the prepared polysiloxane epoxy resin is shown in the appendix Figure 1 , 1 The 1H-NMR spectrum is shown in the appendix Figure 2 , and the infrared spectrum after solidification is shown in the appendix Figure 3 .

[0006] Preferably, the preparation method of the calcium ion-modified silica microspheres is as follows: Prepare an aqueous potassium hydroxide solution with a mass fraction of 12%, add an OP-10 emulsifier with a weight 0.005 times that of the aqueous potassium hydroxide solution, slowly add vinyltrimethoxysilane with a weight 0.2 times that of the potassium hydroxide solution under stirring, heat to 45 °C and stir for 2 h, add an aqueous acetic acid solution with a volume fraction of 10% to adjust the pH to 5, filter, wash with ethanol with a volume 3 times that of the vinyltrimethylsilane, and vacuum dry at 100 °C to constant weight to obtain silica microspheres; Add the obtained silica microspheres to ethanol with a volume 8 times that of the silica microspheres, ultrasonicate for 30 min, add benzoin dimethyl ether with a weight 0.05 times that of the silica microspheres, stir to dissolve, then add mercaptoacetic acid with a weight 0.3 times that of the silica microspheres, stir for 15 min under ultraviolet irradiation, filter, wash with ethanol, and vacuum dry at 100 °C to constant weight to obtain mercapto-modified silica microspheres; Add the obtained mercapto-modified silica microspheres to a 10% calcium chloride aqueous solution with a volume 5 times that of the mercapto-modified silica microspheres, ultrasonicate for 30 min, then stir at room temperature for 12 h, wash with water, wash with ethanol, and vacuum dry at 100 °C to constant weight to obtain; The SEM image of the prepared calcium ion-modified silica microspheres is shown in the appendix Figure 4 , and the infrared spectrum is shown in the appendix Figure 5 .

[0007] Preferably, the preparation method of the microencapsulated ammonium polyphosphate is as follows: Under argon protection, add ammonium polyphosphate to a reaction flask, add ethyl acetate with a volume 10 times that of the ammonium polyphosphate, add 4,4'-diphenylmethane diisocyanate with a weight 0.5 times that of the ammonium polyphosphate and melamine with a weight 0.3 times that of the ammonium polyphosphate under stirring, heat to 55 °C and react for 6 h, add pentaerythritol with a weight 0.4 times that of the ammonium polyphosphate, reflux and react for 3 h, add polyethylene glycol with a weight 1 times that of the ammonium polyphosphate, alkylphenol polyoxyethylene ether with a weight 0.1 times that of the ammonium polyphosphate, and dibutyltin dilaurate with a weight 0.05 times that of the ammonium polyphosphate, continue to reflux and react for 2 h, cool the reaction solution to room temperature and filter, wash the filter cake by pulping with deionized water with a volume 3 times that of the ammonium polyphosphate once, and vacuum dry at 70 °C to constant weight to obtain; The SEM images of the prepared microencapsulated ammonium polyphosphate and ammonium polyphosphate at different magnifications are shown in the appendix Figure 6 .

[0008] Preferably, the preparation method of the pentaerythritol / montmorillonite composite is as follows: Add pentaerythritol with a weight 0.5 times that of the montmorillonite to purified water with a volume 10 times that of the montmorillonite, heat to 60 °C and stir for 20 min, add montmorillonite, stir for 15 min, then adjust the pH to 3 - 4 with a 2M hydrochloric acid aqueous solution, raise the temperature to 75 °C and stir and react for 8 h, filter, wash by pulping with ethanol with a volume 3 times that of the montmorillonite for 10 min each time, wash three times, vacuum dry at 60 °C to constant weight, and grind through a 200-mesh sieve to obtain.

[0009] Preferably, the preparation method of the nano-ZnFe2O4 is as follows: Weigh ferric nitrate nonahydrate and zinc nitrate hexahydrate according to a molar ratio of 2:1 and add them to a reaction flask. Add water with a volume 10 times the weight of the mixture of the two, stir to dissolve, heat to 70 °C and react for 1 h. While stirring, add polysorbate with a weight 0.2 times that of ferric nitrate nonahydrate, stir for 30 min, dropwise add a 10% citric acid aqueous solution to adjust the pH to 6, heat to 80 °C and react for 2 h, filter, and dry to constant weight at 70 °C under vacuum to obtain a precursor. Calcinate the precursor at 500 °C for 2 h and grind to obtain the product. The infrared spectrum of the prepared nano-zinc ferrite crystal is shown in the appendix Figure 7 , and the XRD diffraction pattern of the nano-zinc ferrite obtained after calcination at different temperatures for 2 h is shown in the appendix Figure 8 , and the XRD pattern of the crystal plane of the nano-zinc ferrite obtained after calcination at different temperatures for 2 h is shown in the appendix Figure 9 , and the particle size analysis diagram of the nano-zinc ferrite is shown in the appendix Figure 10 .

[0010] Preferably, the wetting agent is BYK-364.

[0011] A preparation method of a water-resistant and anti-corrosion fireproof coating includes the following preparation steps:

[0012] S1. Add nano-ZnFe2O4 and silica microspheres to a sand mill and disperse them at 2000 rpm until the fineness is ≤ 30 μm;

[0013] S2. Add an organic-inorganic hybrid resin, propanol, and a wetting agent, and stir at 800 rpm for 20 min;

[0014] S3. Slowly add microencapsulated ammonium polyphosphate and the pentaerythritol / montmorillonite complex, and perform ultrasonic treatment (40 kHz) at 40 °C for 30 min;

[0015] S4. Stir and cure for 24 h and then discharge.

[0016] Beneficial effects:

[0017] 1. The epoxy-modified silicone resin and silica sol are compounded to form a dense hydrophobic network. The epoxy group improves the adhesion, and the silicone chain segment reduces the surface energy. The nano-SiO2 fills the micropores to avoid the problem of the fireproof layer failure caused by swelling and peeling of the coating in a humid environment.

[0018] 2. Nano-zinc ferrite (ZnFe2O4) and an ion-exchange type rust inhibitor (calcium ion-modified silica microspheres) cooperate to slow down the electrochemical corrosion of the metal substrate in a high-temperature and high-humidity environment through a dual mechanism of physical shielding and passivation, maintain the structural strength of the metal substrate, and achieve long-term rust prevention and corrosion protection.

[0019] 3. Microencapsulated ammonium polyphosphate combined with pentaerythritol / montmorillonite complex delays the decomposition rate and matches the carbon layer formation kinetics. After the microencapsulated ammonium polyphosphate is decomposed by heat, it releases flame retardant gases such as phosphoric acid and ammonia and forms a carbon layer. The pentaerythritol / montmorillonite complex can capture the decomposition products, promote the formation of a dense carbon layer, and simultaneously inhibit the release of smoke. Description of the Drawings

[0020] Figure 1 Infrared spectrum of the polysiloxane epoxy resin synthesized in the present invention.

[0021] Figure 2 The polysiloxane epoxy resin synthesized in the present invention 1 H-NMR spectrum.

[0022] Figure 3 Infrared spectrum of the solidified polysiloxane epoxy resin synthesized in the present invention.

[0023] Figure 4 SEM image of the calcium ion-modified silicon microspheres of the present invention.

[0024] Figure 5 Infrared spectrum of the calcium ion-modified silicon microspheres of the present invention.

[0025] Figure 6 SEM images of ammonium polyphosphate and microencapsulated ammonium polyphosphate of the present invention at different magnifications;

[0026] Among them, a is the SEM image of ammonium polyphosphate magnified 2000 times, b is the SEM image of ammonium polyphosphate magnified 5000 times, c is the SEM image of microencapsulated ammonium polyphosphate magnified 2000 times, and d is the SEM image of microencapsulated ammonium polyphosphate magnified 5000 times.

[0027] Figure 7 Infrared spectrum of the zinc ferrite nanocrystal of the present invention.

[0028] Figure 8 XRD diffraction patterns of the zinc ferrite obtained after calcination at different temperatures for 2 h in the present invention;

[0029] Among them, a is the XRD diffraction pattern of the zinc ferrite obtained after calcination at 300 °C for 2 h, b is the XRD diffraction pattern of the zinc ferrite obtained after calcination at 400 °C for 2 h, c is the XRD diffraction pattern of the zinc ferrite obtained after calcination at 500 °C for 2 h, and d is the XRD diffraction pattern of the zinc ferrite obtained after calcination at 600 °C for 2 h.

[0030] Figure 9 XRD patterns of the crystal planes of the zinc ferrite obtained after calcination at different temperatures for 2 h in the present invention;

[0031] Among them, a is the XRD pattern of the nanometer zinc ferrite crystal plane obtained after calcination at 300 °C for 2 h, b is the XRD pattern of the nanometer zinc ferrite crystal plane obtained after calcination at 400 °C for 2 h, c is the XRD pattern of the nanometer zinc ferrite crystal plane obtained after calcination at 500 °C for 2 h, and d is the XRD pattern of the nanometer zinc ferrite crystal plane obtained after calcination at 600 °C for 2 h.

[0032] Figure 10 This is the particle size analysis diagram of the nanometer zinc ferrite obtained by the present invention. Detailed implementation manners

[0033] To make the technical solution of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] Raw material preparation:

[0036] Organic-inorganic hybrid resin: Add terminal hydrogen silicone oil (2H2000) to the reaction flask, add p-methoxyphenol with a weight 0.05 times that of the terminal hydrogen silicone oil and a 1% chloroplatinic acid tetrahydrofuran solution with a volume 1 time that of the terminal hydrogen silicone oil under stirring, add 4-vinylbenzyl glycidyl ether with a weight 0.2 times that of the terminal hydrogen silicone oil, heat and reflux for 8 h, concentrate under reduced pressure at 80 °C until no liquid drips out to obtain polysiloxane epoxy resin, and mix the polysiloxane epoxy resin and silica sol (SiO2 particle size 20 - 40 nm) by stirring at a volume ratio of 3:1 - 5:1 for 30 min for compounding to obtain it.

[0037] Calcium ion-modified silica microspheres: Prepare an aqueous potassium hydroxide solution with a mass fraction of 12%, add OP-10 emulsifier with a weight 0.005 times that of the aqueous potassium hydroxide solution, slowly add vinyltrimethoxysilane with a weight 0.2 times that of the potassium hydroxide solution under stirring, heat to 45 °C and stir for 2 h, add an acetic acid aqueous solution with a volume fraction of 10% to adjust the pH to 5, filter, wash with ethanol with a volume 3 times that of the vinyltrimethylsilane, and dry at 100 °C in vacuum until constant weight to obtain silica microspheres; add the obtained silica microspheres to ethanol with a volume 8 times that of the silica microspheres, ultrasonicate for 30 min, add benzoin dimethyl ether with a weight 0.05 times that of the silica microspheres, stir to dissolve, add mercaptoacetic acid with a weight 0.3 times that of the silica microspheres, stir for 15 min under ultraviolet irradiation, filter, wash with ethanol, and dry at 100 °C in vacuum until constant weight to obtain mercapto-modified silica microspheres; add the obtained mercapto-modified silica microspheres to a 10% calcium chloride aqueous solution with a volume 5 times that of the mercapto-modified silica microspheres, ultrasonicate for 30 min, then stir at room temperature for 12 h, wash with water, wash with ethanol, and dry at 100 °C in vacuum until constant weight to obtain them.

[0038] Microencapsulated ammonium polyphosphate: Under argon protection, ammonium polyphosphate was added to a reaction flask, ethyl acetate with a volume 10 times the weight of ammonium polyphosphate was added, 4,4'-diphenylmethane diisocyanate with a weight 0.5 times the weight of ammonium polyphosphate and melamine with a weight 0.3 times the weight of ammonium polyphosphate were added under stirring, heated to 55 °C and reacted for 6 h, pentaerythritol with a weight 0.4 times the weight of ammonium polyphosphate was added, refluxed for 3 h, polyethylene glycol with a weight 1 times the weight of ammonium polyphosphate, alkylphenol polyoxyethylene ether with a weight 0.1 times the weight of ammonium polyphosphate and dibutyltin dilaurate with a weight 0.05 times the weight of ammonium polyphosphate were added, and the reflux reaction was continued for 2 h. The reaction solution was cooled to room temperature and filtered. The filter cake was slurried and washed once with deionized water with a volume 3 times the weight of ammonium polyphosphate, and dried to constant weight at 70 °C under vacuum to obtain the product.

[0039] Pentaerythritol / montmorillonite composite: Pentaerythritol with a weight 0.5 times the weight of montmorillonite was added to purified water with a volume 10 times the weight of montmorillonite, heated to 60 °C and stirred for 20 min, montmorillonite was added, after stirring for 15 min, the pH was adjusted to 3 - 4 with 2M hydrochloric acid aqueous solution, heated to 75 °C and stirred for 8 h, filtered, slurried and washed with ethanol with a volume 3 times the weight of montmorillonite for 10 min each time, washed three times, and dried to constant weight at 60 °C under vacuum, and ground through a 200-mesh sieve to obtain the product.

[0040] Nano-ZnFe₂O₄: Ferric nitrate nonahydrate and zinc nitrate hexahydrate were weighed according to a molar ratio of 2:1 and added to a reaction flask, water with a volume 10 times the weight of the mixture of the two was added, stirred to dissolve, heated to 70 °C and reacted for 1 h, polysorbate with a weight 0.2 times the weight of ferric nitrate nonahydrate was added under stirring, stirred for 30 min, the pH was adjusted to 6 by dropping a 10% citric acid aqueous solution, heated to 80 °C and reacted for 2 h, filtered, and dried to constant weight at 70 °C under vacuum to obtain a precursor. The precursor was calcined at 500 °C for 2 h and ground to obtain the product.

[0041] Preparation process:

[0042] S1. 30 g of nano-ZnFe₂O₄ and 15 g of calcium ion-modified silica microspheres were added to a sand mill and dispersed at 2000 rpm until the fineness was ≤ 30 μm;

[0043] S2. 300 g of organic-inorganic hybrid resin, 15 g of propanol, and 1.5 g of wetting agent BYK-364 were added and stirred at 800 rpm for 20 min;

[0044] S3. 100 g of microencapsulated ammonium polyphosphate and 50 g of pentaerythritol / montmorillonite composite were slowly added and ultrasonically treated at 40 °C (40 kHz) for 30 min;

[0045] S4. After stirring and curing for 24 h, the product was discharged.

[0046] Example 2

[0047] Raw material preparation:

[0048] Organic-inorganic hybrid resin: Add hydrogen-terminated silicone oil (2H2000) into a reaction flask, and under stirring, add p-methoxyphenol with a weight 0.05 times that of the hydrogen-terminated silicone oil and a solution of chloroplatinic acid in tetrahydrofuran with a mass fraction of 1% of chloroplatinic acid and a volume 1 time that of the hydrogen-terminated silicone oil. Then add 4-vinylbenzyl glycidyl ether with a weight 0.2 times that of the hydrogen-terminated silicone oil, and heat under reflux for 8 h. Concentrate under reduced pressure at 80 °C until no liquid drips out to obtain polysiloxane epoxy resin. Mix the polysiloxane epoxy resin and silica sol (SiO2 particle size 20 - 40 nm) by stirring at a volume ratio of 3:1 - 5:1 for 30 min for compounding, and it is obtained.

[0049] Calcium ion-modified silica microspheres: Prepare an aqueous potassium hydroxide solution with a mass fraction of 12%, add OP-10 emulsifier with a weight 0.005 times that of the aqueous potassium hydroxide solution, and slowly add vinyltrimethoxysilane with a weight 0.2 times that of the potassium hydroxide solution under stirring. Heat to 45 °C and stir for 2 h, add an aqueous acetic acid solution with a volume fraction of 10% to adjust the pH to 5, filter, wash with ethanol with a volume 3 times that of the vinyltrimethylsilane, and dry in vacuum at 100 °C to constant weight to obtain silica microspheres; Add the obtained silica microspheres into ethanol with a volume 8 times that of the silica microspheres, ultrasonicate for 30 min, add benzoin dimethyl ether with a weight 0.05 times that of the silica microspheres, stir to dissolve, then add mercaptoacetic acid with a weight 0.3 times that of the silica microspheres, stir under ultraviolet irradiation for 15 min, filter, wash with ethanol, and dry in vacuum at 100 °C to constant weight to obtain mercapto-modified silica microspheres; Add the obtained mercapto-modified silica microspheres into a 10% aqueous calcium chloride solution with a volume 5 times that of the mercapto-modified silica microspheres, ultrasonicate for 30 min, then stir at room temperature for 12 h, wash with water and ethanol, and dry in vacuum at 100 °C to constant weight to obtain.

[0050] Microencapsulated ammonium polyphosphate: Under argon protection, add ammonium polyphosphate into a reaction flask, add ethyl acetate with a volume 10 times that of the ammonium polyphosphate, add 4,4'-diphenylmethane diisocyanate with a weight 0.5 times that of the ammonium polyphosphate and melamine with a weight 0.3 times that of the ammonium polyphosphate under stirring, heat to 55 °C and react for 6 h, add pentaerythritol with a weight 0.4 times that of the ammonium polyphosphate, reflux and react for 3 h, add polyethylene glycol with a weight 1 times that of the ammonium polyphosphate, alkylphenol polyoxyethylene ether with a weight 0.1 times that of the ammonium polyphosphate and dibutyltin dilaurate with a weight 0.05 times that of the ammonium polyphosphate, continue to reflux and react for 2 h, cool the reaction solution to room temperature and filter, wash the filter cake once by pulping with deionized water with a volume 3 times that of the ammonium polyphosphate, and dry in vacuum at 70 °C to constant weight to obtain.

[0051] Pentaerythritol / montmorillonite composite: Add pentaerythritol with a weight 0.5 times that of montmorillonite into purified water with a volume 10 times that of montmorillonite's weight, heat to 60 °C and stir for 20 min, add montmorillonite, after stirring for 15 min, adjust the pH to 3 - 4 with 2M hydrochloric acid aqueous solution, raise the temperature to 75 °C and stir for 8 h, filter, wash by pulping with ethanol with a volume 3 times that of montmorillonite's weight for 10 min each time, wash three times, dry at 60 °C in vacuum until constant weight, and grind through a 200-mesh sieve to obtain it.

[0052] Nano-ZnFe₂O₄: Weigh ferric nitrate nonahydrate and zinc nitrate hexahydrate according to a molar ratio of 2:1 and add them to a reaction flask, add water with a volume 10 times that of the mixture's weight, stir to dissolve, heat to 70 °C and react for 1 h, add polysorbate with a weight 0.2 times that of ferric nitrate nonahydrate under stirring, stir for 30 min, dropwise add 10% citric acid aqueous solution to adjust the pH = 6, heat to 80 °C and react for 2 h, filter, dry at 70 °C in vacuum until constant weight to obtain the precursor, calcine the precursor at 500 °C for 2 h, and grind to obtain it.

[0053] Preparation process:

[0054] S1. Add 37.5 g of nano-ZnFe₂O₄ and 25 g of calcium ion-modified silica microspheres to a sand mill, disperse at 2000 rpm until the fineness ≤ 30 μm;

[0055] S2. Add 350 g of organic-inorganic hybrid resin, 20 g of propanol, and 2 g of wetting agent BYK-364, stir at 800 rpm for 20 min;

[0056] S3. Slowly add 125 g of microencapsulated ammonium polyphosphate and 60 g of pentaerythritol / montmorillonite composite, and perform ultrasonic treatment (40 kHz) at 40 °C for 30 min;

[0057] S4. Stir and cure for 24 h and then discharge.

[0058] Example 3

[0059] Raw material preparation:

[0060] Organic-inorganic hybrid resin: Add terminal hydrogen silicone oil (2H2000) to a reaction flask, add p-methoxyphenol with a weight 0.05 times that of terminal hydrogen silicone oil and a 1% chloroplatinic acid tetrahydrofuran solution with a volume 1 times that of terminal hydrogen silicone oil's weight under stirring, add 4-vinylbenzyl glycidyl ether with a weight 0.2 times that of terminal hydrogen silicone oil, heat to reflux and react for 8 h, concentrate under reduced pressure at 80 °C until no liquid drips out to obtain polysiloxane epoxy resin, and mix and compound the polysiloxane epoxy resin and silica sol (SiO₂ particle size 20 - 40 nm) at a volume ratio of 3:1 - 5:1 by stirring for 30 min to obtain it.

[0061] Calcium ion-modified silica microspheres: Prepare an aqueous potassium hydroxide solution with a mass fraction of 12%, add OP-10 emulsifier with a weight 0.005 times that of the aqueous potassium hydroxide solution, slowly add vinyltrimethoxysilane with a weight 0.2 times that of the potassium hydroxide solution while stirring, heat to 45 °C and stir for 2 h, add an aqueous acetic acid solution with a volume fraction of 10% to adjust the pH to 5, filter, wash with ethanol with a volume 3 times that of the vinyltrimethylsilane weight, and dry in vacuum at 100 °C to constant weight to obtain silica microspheres; add the obtained silica microspheres to ethanol with a volume 8 times that of the silica microspheres weight, ultrasonicate for 30 min, add benzoin dimethyl ether with a weight 0.05 times that of the silica microspheres weight, stir to dissolve, then add mercaptoacetic acid with a weight 0.3 times that of the silica microspheres weight, stir for 15 min under ultraviolet irradiation, filter, wash with ethanol, and dry in vacuum at 100 °C to constant weight to obtain mercapto-modified silica microspheres; add the obtained mercapto-modified silica microspheres to a 10% calcium chloride aqueous solution with a volume 5 times that of the mercapto-modified silica microspheres weight, ultrasonicate for 30 min, then stir at room temperature for 12 h, wash with water, wash with ethanol, and dry in vacuum at 100 °C to constant weight to obtain the product.

[0062] Microencapsulated ammonium polyphosphate: Under argon protection, add ammonium polyphosphate to a reaction flask, add ethyl acetate with a volume 10 times that of the ammonium polyphosphate weight, add 4,4'-diphenylmethane diisocyanate with a weight 0.5 times that of the ammonium polyphosphate weight and melamine with a weight 0.3 times that of the ammonium polyphosphate weight while stirring, heat to 55 °C and react for 6 h, add pentaerythritol with a weight 0.4 times that of the ammonium polyphosphate weight, reflux and react for 3 h, add polyethylene glycol with a weight 1 times that of the ammonium polyphosphate weight, alkylphenol polyoxyethylene ether with a weight 0.1 times that of the ammonium polyphosphate weight, and dibutyltin dilaurate with a weight 0.05 times that of the ammonium polyphosphate weight, continue to reflux and react for 2 h, cool the reaction solution to room temperature and filter, wash the filter cake once by slurrying with deionized water with a volume 3 times that of the ammonium polyphosphate weight, and dry in vacuum at 70 °C to constant weight to obtain the product.

[0063] Pentaerythritol / montmorillonite composite: Add pentaerythritol with a weight 0.5 times that of the montmorillonite weight to purified water with a volume 10 times that of the montmorillonite weight, heat to 60 °C and stir for 20 min, add montmorillonite, stir for 15 min, adjust the pH to 3 - 4 with 2M hydrochloric acid aqueous solution, raise the temperature to 75 °C and stir and react for 8 h, filter, wash by slurrying with ethanol with a volume 3 times that of the montmorillonite weight for 10 min each time, wash three times, dry in vacuum at 60 °C to constant weight, and grind through a 200-mesh sieve to obtain the product.

[0064] Nano-ZnFe2O4: Weigh ferric nitrate nonahydrate and zinc nitrate hexahydrate according to the molar ratio of 2:1 and add them to the reaction flask. Add water with a volume 10 times the weight of the mixture of the two, stir to dissolve, heat to 70 °C and react for 1 h. Add polysorbate with a weight 0.2 times that of ferric nitrate nonahydrate under stirring, stir for 30 min, add a 10% citric acid aqueous solution dropwise to adjust the pH to 6, heat to 80 °C and react for 2 h. Filter and dry in a vacuum at 70 °C to constant weight to obtain the precursor. Calcinate the precursor at 500 °C for 2 h and grind to obtain it.

[0065] Preparation process:

[0066] S1. Add 45 g of nano-ZnFe2O4 and 35 g of calcium ion-modified silica microspheres to a sand mill and disperse them at 2000 rpm until the fineness is ≤ 30 μm;

[0067] S2. Add 400 g of organic-inorganic hybrid resin, 25 g of propanol, and 3 g of wetting agent BYK-364, and stir at 800 rpm for 20 min;

[0068] S3. Slowly add 150 g of microencapsulated ammonium polyphosphate and 75 g of pentaerythritol / montmorillonite complex, and perform ultrasonic treatment (40 kHz) at 40 °C for 30 min;

[0069] S4. Stir and cure for 24 h and then discharge.

[0070] Compare the water-resistant and corrosion-resistant fireproof coatings prepared in Examples 1 to 3 with commercially available intumescent fireproof coatings. Perform water contact angle tests by the static contact angle method to measure their water resistance; measure their initial decomposition temperature (temperature at 10% weight loss) and half-life temperature (temperature at 50% weight loss) by thermogravimetry to measure their fireproof performance; coat the coating on an iron rod, and after complete curing, soak it in a 3% sodium chloride aqueous solution at 95 °C for 20 days to observe its corrosion resistance.

[0071] Table 1 Test results of examples and commercially available fireproof coatings

[0072]

[0073] By comparing with the commercially available intumescent fireproof coatings through examples, the water contact angle is ≥ 86°, far superior to 57.6° of the commercially available products. The initial decomposition temperature and half-life temperature are both higher than those of the commercially available products, and after soaking in high-temperature brine, its effect is also better than that of the commercially available products. From the comparison data and phenomena, it can be seen that the present invention has obvious improvements in water resistance, corrosion resistance, and fireproof performance compared with the commercially available products.

[0074] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

1. A water-resistant and anti-corrosion fire-retardant coating, characterized in that: The composition comprises the following components and their proportions by weight: 60-80 parts of organic-inorganic hybrid resin, 20-30 parts of microencapsulated ammonium polyphosphate, 10-15 parts of pentaerythritol / montmorillonite composite, 6-9 parts of nano ZnFe2O4, 3-7 parts of calcium ion modified silicon microspheres, 0.3-0.6 parts of wetting agent, and 3-5 parts of propanol; The preparation method of the organic-inorganic hybrid resin is as follows: add terminal hydrogen silicone oil into a reaction bottle, add p-hydroxyanisole whose weight is 0.05 times of the weight of the terminal hydrogen silicone oil and 1% chloroplatinic acid tetrahydrofuran solution whose volume is 1 times of the weight of the terminal hydrogen silicone oil under stirring, add 4-vinylbenzyl glycidyl ether whose weight is 0.2 times of the weight of the terminal hydrogen silicone oil, heat and reflux for reaction for 8 hours, reduce pressure to 80°C and concentrate until no liquid drips out to obtain polysilicone epoxy resin, and compound the polysilicone epoxy resin and silica sol at a volume ratio of 3:1-5:1 and stir and mix for 30 minutes to obtain the obtained resin; The preparation method of calcium ion modified silicon microspheres is as follows: prepare a potassium hydroxide aqueous solution with a mass fraction of 12%, add an OP-10 emulsifier with a weight of 0.005 times the weight of the potassium hydroxide aqueous solution, slowly add vinyltrimethoxysilane with a weight of 0.2 times the weight of the potassium hydroxide solution under stirring, heat to 45°C and stir for 2h, add acetic acid aqueous solution with a volume fraction of 10% to adjust the pH to 5, filter, rinse with ethanol with a volume of 3 times the weight of the vinyltrimethoxysilane, and vacuum dry at 100°C to constant weight to obtain silicon microspheres; add ethanol with a volume of 8 times the weight of the silicon microspheres to the obtained silicon microspheres. ethanol, ultrasonically treat for 30 minutes, add benzoin dimethyl ether whose weight is 0.05 times of the weight of the silicon microspheres, stir and dissolve, add thioglycolic acid whose weight is 0.3 times of the weight of the silicon microspheres, stir for 15 minutes under ultraviolet irradiation, filter, rinse with ethanol, and dry in vacuum at 100°C to constant weight to obtain thiol-modified silicon microspheres; add the obtained thiol-modified silicon microspheres to a 10% calcium chloride aqueous solution whose volume is 5 times of the weight of the thiol-modified silicon microspheres, ultrasonically treat for 30 minutes, stir at room temperature for 12 hours, wash with water, wash with ethanol, and dry in vacuum at 100°C to constant weight to obtain; The preparation method of microencapsulated ammonium polyphosphate is as follows: under argon protection, ammonium polyphosphate is added to a reaction bottle, ethyl acetate is added in a volume 10 times the weight of the ammonium polyphosphate, 4,4'-diphenylmethane diisocyanate in a volume 0.5 times the weight of the ammonium polyphosphate and melamine in a volume 0.3 times the weight of the ammonium polyphosphate are added under stirring, the reaction is heated to 55°C for 6 hours, pentaerythritol in a volume 0.4 times the weight of the ammonium polyphosphate is added, the reaction is refluxed for 3 hours, polyethylene glycol in a volume 1 times the weight of the ammonium polyphosphate, alkylphenol polyoxyethylene ether in a volume 0.1 times the weight of the ammonium polyphosphate and dibutyltin dilaurate in a volume 0.05 times the weight of the ammonium polyphosphate are added, the reaction is continued under reflux for 2 hours, the reaction solution is cooled to room temperature and filtered, the filter cake is slurried and washed once with deionized water in a volume 3 times the weight of the ammonium polyphosphate, and vacuum dried at 70°C to constant weight.

2. The water-resistant and anti-corrosion fire-retardant coating according to claim 1, characterized in that: The preparation method of the pentaerythritol / montmorillonite composite is as follows: add pentaerythritol with a weight of 0.5 times the weight of montmorillonite to purified water with a volume of 10 times the weight of montmorillonite, heat to 60°C and stir for 20 minutes, add montmorillonite, stir for 15 minutes, adjust the pH to 3-4 with 2M hydrochloric acid aqueous solution, heat to 75°C and stir to react for 8 hours, filter, and wash with ethanol with a volume of 3 times the weight of montmorillonite for 10 minutes each time, wash three times, vacuum dry at 60°C to constant weight, and grind through a 200-mesh sieve to obtain.

3. The water-resistant and anti-corrosion fire-retardant coating according to claim 1, characterized in that: The preparation method of nano ZnFe2O4 is as follows: weigh ferric nitrate nonahydrate and zinc nitrate hexahydrate in a molar ratio of 2:1 and add them to a reaction bottle, add water 10 times the weight of the mixture of the two, stir to dissolve, heat to 70°C to react for 1 hour, add polysorbate 0.2 times the weight of ferric nitrate nonahydrate under stirring, stir for 30 minutes, add 10% citric acid aqueous solution to adjust the pH to 6, heat to 80°C to react for 2 hours, filter, and dry at 70 degrees Celsius in vacuum to constant weight to obtain a precursor, calcine the precursor at 500°C for 2 hours, and grind it.

4. The water-resistant and anti-corrosion fire-retardant coating according to claim 1, characterized in that: The wetting agent is BYK-364.

5. A method for preparing a water-resistant and anticorrosive fire-retardant coating according to any one of claims 1 to 4, characterized in that: The method comprises the following preparation steps: S1. Add nano ZnFe2O4 and calcium ion modified silicon microspheres into a sand mill and disperse at 2000 rpm until the fineness is ≤30 μm; S2, adding organic-inorganic hybrid resin, propanol and wetting agent, stirring at 800 rpm for 20 min; S3, slowly add microencapsulated ammonium polyphosphate and pentaerythritol / montmorillonite composite, and perform ultrasonic treatment at 40°C for 30 min; S4, stirring and ripening for 24 hours before discharging.

Images