Polyaniline-silicon carbide modified intumescent fire-retardant anticorrosive coating and preparation method

Abstract

This invention discloses a polyaniline-silicon carbide modified intumescent fire-retardant and anti-corrosion coating and its preparation method. The water-based coating consists of component A (water-based epoxy emulsion, polyaniline-silicon carbide composite material, flame-retardant filler, titanium dioxide, aluminum hydroxide, talc, wetting and dispersing agent, defoamer, leveling agent, film-forming aid, and water) and component B (epoxy curing agent). The polyaniline-silicon carbide composite material is prepared by an ice bath reaction of silicon carbide, aniline, protic acid, and oxidant. In this invention, the polyaniline-silicon carbide composite material enhances the dispersibility in the emulsion through organic-inorganic fusion. Silicon carbide exhibits high thermal stability and good density, while polyaniline provides unique flame-retardant properties. The synergistic effect of these two materials effectively improves the fire resistance and anti-corrosion performance of the coating, enhances the strength of the intumescent layer, and solves the problems of peeling and burn-through that arise when using intumescent fire-retardant coatings in conjunction with anti-corrosion primers, demonstrating promising application prospects.

Description

Technical Field

[0001] This invention relates to coating technology, specifically to a fire-retardant coating, and more specifically to an intumescent fire-retardant and anti-corrosion coating modified with polyaniline-silicon carbide and its preparation method. Background Technology

[0002] In steel structure environments such as substations, chemical plants, and factories, fire is a major risk factor causing steel structure collapse and resulting in serious accidents. Currently, intumescent fire-retardant coatings are used to prevent fire-induced steel structure collapses that could lead to casualties and economic losses. However, existing intumescent systems do not provide ideal protection in actual fires. This is mainly because, during a fire, the rapid expansion and gas generation of intumescent fire-retardant coatings can only withstand 10-20 minutes of fiber fire. As combustion continues on the surface, large-scale peeling occurs. Most importantly, the strength of the intumescent layer is very low, failing to prevent rapid heat transfer, leading to burn-through and inability to prevent the steel structure from losing strength. This paper utilizes the unique flame-retardant properties of polyaniline combined with the thermal stability and void-filling ability of silicon carbide to prepare a polyaniline-silicon carbide composite material. Further, a polyaniline-silicon carbide modified intumescent fire-retardant and anti-corrosion coating is prepared, achieving high expansion strength and high expansion ratio. This synergistically improves the coating's fire resistance, providing sufficient escape and rescue time in critical locations and effectively reducing casualties and economic losses. Summary of the Invention

[0003] The purpose of this invention is to provide a polyaniline-silicon carbide modified intumescent fire-retardant and anti-corrosion coating and its preparation method. A polyaniline-silicon carbide composite material is prepared using silicon carbide, aniline, protic acid, and an oxidant. This further develops the polyaniline-silicon carbide modified intumescent fire-retardant and anti-corrosion coating, improving its fire resistance and anti-corrosion performance. It primarily addresses the problems of traditional fire-retardant and anti-corrosion coatings, such as the easy peeling of the underlying anti-corrosion primer due to its poor temperature resistance, and the collapse of steel structures caused by the low strength and poor density of the fire-retardant coating. This invention provides effective fire and corrosion protection for important locations such as substations, chemical plants, and factories. To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0004] A polyaniline-silicon carbide modified intumescent fireproof and anticorrosive coating, the coating being composed of the following components: waterborne epoxy emulsion, polyaniline-silicon carbide composite material, flame retardant filler, titanium dioxide, aluminum hydroxide, talc, wetting and dispersing agent, defoamer, leveling agent, film-forming aid, water, and epoxy curing agent.

[0005] As a preferred technical solution, the weight fraction of the coating formulation is as follows:

[0006] Component A

[0007] Waterborne epoxy emulsion 20-50

[0008] Polyaniline-silicon carbide composite material 0.5-10

[0009] Flame retardant filler 30-50

[0010] Titanium dioxide 1-5

[0011] Aluminum hydroxide 1-5

[0012] talcum powder 1-5

[0013] Wetting and dispersing agent 0.5-3

[0014] Defoamer 0.5-3

[0015] Leveling agent 0-3

[0016] Film-forming aid 1-10

[0017] Water 0-10

[0018] Component B

[0019] Epoxy curing agent 5-15

[0020] None of the above component ranges include the endpoint 0.

[0021] As a preferred technical solution, the aqueous epoxy emulsion is one or a combination of several of the following: bisphenol A type aqueous epoxy resin emulsion, bisphenol F type aqueous epoxy resin emulsion, and aqueous acrylic modified epoxy emulsion.

[0022] As a preferred technical solution, the polyaniline-silicon carbide composite material is prepared by reacting silicon carbide, aniline, protic acid, oxidant, etc. in an ice bath.

[0023] Further optimization, the specific reaction steps are as follows:

[0024] The protic acid was prepared into an aqueous solution and placed in an ice-water mixture in an ice bath. Aniline and silicon carbide were added to the protic acid solution and stirred continuously to disperse them evenly, thus obtaining a reaction solution.

[0025] Prepare an aqueous solution of oxidant, slowly add the oxidant dropwise to the reaction solution while stirring continuously, and react for 1-2 hours. Centrifuge and filter the suspension, wash with deionized water, and obtain the polyaniline-silicon carbide composite material.

[0026] As a preferred technical solution, the oxidant is including, but not limited to, persulfate, hydrogen peroxide, ferric chloride, etc.

[0027] As a preferred technical solution, the protic acid is any one of sulfuric acid, hydrochloric acid, and phosphoric acid, with a concentration of about 0.1-0.3M (mol per liter), preferably 0.2M.

[0028] As a preferred technical solution, the flame-retardant filler includes acid source filler, carbon source filler and gas source filler.

[0029] Further preferably, the acid source filler is selected from any one or more of ammonium polyphosphate, ammonium polyphosphate, and ammonium hydrogen phosphate; the carbon source filler is selected from one or two of pentaerythritol and dipentaerythritol; and the gas source filler is selected from one or two of melamine and dicyandiamide.

[0030] As a preferred technical solution, the leveling agent is a polyether-modified silicone leveling agent, such as RianPont2903 produced by Sichuan Ruikaibang Chemical Materials Co., Ltd.

[0031] As a preferred technical solution, the defoamer is an emulsified polysiloxane.

[0032] As a preferred technical solution, the dispersant is a nonionic surfactant, including alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene alkylamine, polyether, etc.

[0033] As a preferred technical solution, the epoxy curing agent is an amine-based curing agent.

[0034] As a preferred technical solution, the film-forming aid is one or more of propylene glycol methyl ether, hexanediol, and ethylene glycol ethyl ether.

[0035] On the other hand, the present invention also provides a method for preparing a polyaniline-silicon carbide modified intumescent fire-retardant and anti-corrosion coating, comprising the following steps:

[0036] According to the formula weight ratio, mix 20-50 parts of waterborne epoxy emulsion, 0.5-10 parts of polyaniline-silicon carbide composite material, 30-50 parts of flame retardant filler, 1-5 parts of titanium dioxide, 1-5 parts of aluminum hydroxide, 1-5 parts of talc, 0.5-3 parts of dispersant, half of 0.5-3 parts of defoamer, 0-3 parts of leveling agent, half of 1-10 parts of film-forming aid, and 0-10 parts of water, and disperse at a speed of 2000-3000 r / min for 15-30 min (optimal 25 min).

[0037] Add film-forming aid and defoamer once each, and stir at 1000-1500 r / min for 8-14 min (optimal 10 min) to obtain component A;

[0038] The amine curing agent was stirred evenly to obtain component B;

[0039] Components A and B are mixed evenly to obtain an intumescent fire-retardant and anti-corrosion coating that can be used for coating.

[0040] After coating, the dry film thickness of the coated sample is 3 mm.

[0041] The principle of this invention is as follows:

[0042] This invention uses an aqueous epoxy emulsion as the main film-forming substance, which is non-toxic, odorless, and has excellent adhesion properties. Simultaneously, a polyaniline-silicon carbide composite material is prepared using an ice bath method, fully leveraging the high thermal stability and good density of silicon carbide, and the unique flame-retardant and anti-corrosion effects of polyaniline, synergistically improving the density, thermal stability, and expansion layer strength of the coating material. Finally, by combining the fire-retardant properties and filling capabilities of materials such as titanium dioxide, aluminum hydroxide, and talc, excellent anti-corrosion performance is provided before a fire occurs, and highly efficient flame-retardant performance is provided during a sudden fire, ensuring the safety of life and property.

[0043] The beneficial effects of this invention are as follows:

[0044] (1) The polyaniline-silicon carbide modified intumescent fireproof and anticorrosive coating prepared in this invention uses water-based epoxy emulsion as base material, polyaniline-silicon carbide composite material, titanium dioxide, aluminum hydroxide, talc powder, etc. as fillers, and acid source, carbon source and gas source as the main intumescent fillers. It has the characteristics of high density, good corrosion resistance, good stability of the intumescent layer and long flame retardant time.

[0045] (2) The polyaniline-silicon carbide composite material prepared in this invention utilizes the excellent thermal stability of sheet silicon carbide, the barrier effect of corrosive media, and the unique flame retardant and anti-corrosion properties of polyaniline. The combination of the two realizes the combination of organic and inorganic materials, which fully improves the density, corrosion resistance, expansion layer strength and fire resistance and heat insulation performance of the coating. It synergistically solves the problems faced by fireproof coating materials such as insufficient fireproof and anti-corrosion performance, easy peeling and easy burn-through, and breaks through the formulation system and preparation technology of integrated fireproof and anti-corrosion coating materials. Attached Figure Description

[0046] Figure 1 This is a SEM image of the polyaniline-silicon carbide composite material.

[0047] Figure 2 The morphology of the intumescent fireproof and anticorrosive coating obtained in Example 1 after 2 hours of combustion.

[0048] Figure 3 The morphology of the intumescent fireproof and anticorrosive coating obtained in Example 2 after 2 hours of combustion.

[0049] Figure 4 The morphology of the intumescent fireproof and anticorrosive coating obtained in Example 3 after 2 hours of combustion.

[0050] Figure 5The images show a comparison of the intumescent fire-retardant and anti-corrosion coating layer obtained in Example 1 before and after a 192-hour salt spray test. Figure 5 Image 'a' in the middle is the image before corrosion. Figure 5 Image b in the middle is the image after corrosion.

[0051] Figure 6 The compressive strength of the intumescent fireproof and anticorrosive coating layer obtained in Example 1. Detailed Implementation

[0052] To better understand the present invention, the specific technical solution of the polyaniline-silicon carbide modified intumescent fireproof and anticorrosive coating and its preparation method according to the present invention will be clearly and completely described and explained below with reference to the embodiments of the present invention and the accompanying drawings. However, this should not be construed as limiting the scope of protection and implementation of the present invention.

[0053] An example of a polyaniline-silicon carbide modified intumescent fire-retardant and anti-corrosion coating and its preparation method is as follows:

[0054] Example 1:

[0055] a) Prepare 1 L of 0.2 M (mol / L, the same below) hydrochloric acid solution and place it in an ice bath in an ice-water mixture. Add 9.1 mL of polyaniline monomer (aniline) and 4.0 g of silicon carbide to the hydrochloric acid solution and stir continuously to disperse evenly.

[0056] b) Prepare 200 mL of 0.5 M ammonium persulfate oxidant aqueous solution. Slowly add the ammonium persulfate oxidant aqueous solution to the solution in a), stirring constantly. React for 1-2 h. Centrifuge and filter the suspension, and wash it 5 times with deionized water to obtain the polyaniline-silicon carbide composite material. Characterize the polyaniline-silicon carbide composite material by electron microscopy as follows: Figure 1 As shown.

[0057] c) According to the formula ratio, mix 50 parts of waterborne epoxy emulsion, 7 parts of polyaniline-silicon carbide composite material, 44 parts of flame retardant filler, 4 parts of titanium dioxide, 3 parts of aluminum hydroxide, 5 parts of talc, 2 parts of dispersant, 1 part of defoamer, 1 part of leveling agent, 3 parts of film-forming aid and 5 parts of water, and disperse at a speed of 2000-3000 r / min for 25 min;

[0058] d) Add film-forming aid (3 parts) and defoamer (1 part) once each, adjust to 1000-1500 r / min and stir for 10 min to obtain component A;

[0059] e) Mix 10 parts of the amine curing agent (component B) and component A uniformly to obtain an intumescent fire-retardant and anti-corrosion coating suitable for application. The dry film thickness of the coated sample is 3 mm. The coated sample is then subjected to a 1.5-hour combustion test, and the results are as follows: Figure 2As shown, the compressive strength test results for the coated samples are as follows: Figure 5 As shown.

[0060] Example 2:

[0061] a) Dilute hydrochloric acid to prepare 1 L of 0.2 M aqueous solution, place it in an ice-water mixture ice bath, add 9.1 mL of polyaniline monomer and 4.0 g of silicon carbide to the hydrochloric acid solution, and stir continuously to disperse evenly;

[0062] b) Prepare 200 mL of 0.5 M ammonium persulfate oxidant aqueous solution, slowly add the oxidant dropwise to solution a), stir continuously, react for 1-2 h, centrifuge and filter the suspension, wash 5 times with deionized water to obtain polyaniline-silicon carbide composite material;

[0063] c) According to the formula ratio, mix 50 parts of waterborne epoxy emulsion, 10 parts of polyaniline-silicon carbide composite material, 37 parts of flame retardant filler, 5 parts of titanium dioxide, 5 parts of aluminum hydroxide, 3 parts of talc, 2 parts of dispersant, 1 part of defoamer, 2 parts of leveling agent, 3 parts of film-forming aid and 7 parts of water, and disperse at a speed of 2000-3000 r / min for 25 min;

[0064] d) Add equal amounts of film-forming aid (3 parts) and defoamer (1 part) once each, adjust to 1000-1500 r / min and stir for 10 min to obtain component A;

[0065] e) Mix 8 parts of the amine curing agent (component B) and component A evenly to obtain an intumescent fireproof and anticorrosive coating that can be used for coating. The dry film thickness of the coating sample is 3 mm.

[0066] Example 3:

[0067] a) Dilute hydrochloric acid to prepare 1 L of 0.2 M aqueous solution, place it in an ice-water mixture ice bath, add 9.1 mL of polyaniline monomer and 4.0 g of silicon carbide to the hydrochloric acid solution, and stir continuously to disperse evenly;

[0068] b) Prepare 200 mL of 0.5 M ammonium persulfate oxidant aqueous solution, slowly add the oxidant dropwise to solution a), stir continuously, react for 1-2 h, centrifuge and filter the suspension, wash 5 times with deionized water to obtain polyaniline-silicon carbide composite material;

[0069] c) According to the formula ratio, mix 45 parts of waterborne epoxy emulsion, 7 parts of polyaniline-silicon carbide composite material, 40 parts of flame retardant filler, 2 parts of titanium dioxide, 2 parts of aluminum hydroxide, 4 parts of talc, 3 parts of dispersant, 2 parts of defoamer, 3 parts of leveling agent, 3 parts of film-forming aid and 7 parts of water, and disperse at a speed of 2000-3000 r / min for 25 min;

[0070] d) Add equal amounts of film-forming aid (3 parts) and defoamer (1 part) once each, adjust to 1000-1500 r / min and stir for 10 min to obtain component A;

[0071] e) Mix 8 parts of the amine curing agent (component B) and component A evenly to obtain an intumescent fireproof and anticorrosive coating that can be used for coating. The dry film thickness of the coating sample is 3 mm.

[0072] SEM observation of the polyaniline-silicon carbide composite material in Example 1 of this invention showed that polyaniline adhered to the surface of silicon carbide particles ( Figure 1 This can effectively improve the compatibility and dispersibility of silicon carbide in resin. Large-plate experiments were conducted on samples from Examples 1, 2, and 3, and their dilatation photographs are shown below. Figure 2 , Figure 3 and Figure 4 As shown, the expansion ratios are 10, 7, and 7 times, respectively. Figure 5 The corrosion resistance of the coating in Example 1 was tested using a salt spray test. After 192 hours of testing, no significant erosion was observed at the scratches on the coating. The compressive strength of the expansion layer was tested as follows. Figure 6 As can be seen, it remained intact under the weight of 2.5 kg, indicating that the expansion layer has excellent strength. In summary, the polyaniline-silicon carbide coating fully combines the flame-retardant properties of polyaniline and the thermal insulation properties of silicon carbide, synergistically enhancing the coating's density, corrosion resistance, expansion effect, and compressive strength of the expansion layer. It also promotes the formation of a dense expansion layer on its surface, providing excellent thermal insulation against fire.

[0073] It must be noted that the above description is for illustrative purposes only and is not intended to limit the invention. Those skilled in the art should understand that any simplifications, combinations, substitutions, or other modifications made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A polyaniline-silicon carbide modified intumescent fire-retardant anticorrosive coating, characterized by, The paint formulation is made of the following components by weight: A component Waterborne epoxy emulsion 20-50 Polystyrene-silicon carbide composite material 0.5-10 Flame-retardant filler 30-50 Titanium dioxide 1-5 Aluminum hydroxide 1-5 Talc 1-5 Wetting dispersant 0.5-3 Defoaming agent 0.5-3 Leveling agent 0-3 Film-forming aid 1-10 Water 0-10 B component Epoxy curing agent 5-15 The above component ranges do not include the endpoints 0; The waterborne epoxy emulsion is a combination of one or more of bisphenol A type waterborne epoxy resin emulsion, bisphenol F type waterborne epoxy resin emulsion, and waterborne acrylic modified epoxy emulsion; The specific reaction steps of the polystyrene-silicon carbide composite material are as follows: The protonic acid is configured into an aqueous solution, which is placed in an ice water mixture ice bath, aniline and silicon carbide are added to the protonic acid solution, and they are dispersed uniformly under constant stirring to obtain a reaction solution; An oxidizing agent aqueous solution is configured, and the oxidizing agent is slowly added to the reaction solution under constant stirring, and the reaction is carried out for 1-2 h, then the suspension is centrifuged and filtered, and washed with deionized water to obtain a polystyrene-silicon carbide composite material; The protonic acid is any one of sulfuric acid, hydrochloric acid, and phosphoric acid, with a concentration of 0.1-0.3 M; The flame-retardant filler includes an acid source filler, a carbon source filler, and a gas source filler; The acid source filler is selected from any one or more of ammonium polyphosphate and ammonium hydrogen phosphate; the carbon source filler is selected from one or both of pentaerythritol and dipentaerythritol; and the gas source filler is selected from one or both of melamine and dicyandiamide.

2. The polyaniline-silicon carbide modified intumescent fire-retardant and anticorrosive coating according to claim 1, characterized in that, The leveling agent is a polyether-modified high-molecular organic silicon leveling agent.

3. The polyaniline-silicon carbide modified intumescent fire-retardant and anticorrosive coating according to claim 1, characterized in that, The defoaming agent is an emulsified polysiloxane.

4. The polyaniline-silicon carbide modified intumescent fire-retardant and anticorrosive coating according to claim 1, characterized in that, The dispersant is a non-ionic surfactant.

5. The polyaniline-silicon carbide modified intumescent fire-retardant and anticorrosive coating according to claim 1, characterized in that, The epoxy curing agent is an amine curing agent.

6. The polyaniline-silicon carbide modified intumescent fire-retardant and anticorrosive coating according to claim 1, characterized in that, The film-forming aid is a combination of one or more of propylene glycol methyl ether, hexylene glycol, and ethylene glycol ethyl ether.

7. A method for preparing the polyaniline-silicon carbide modified intumescent fire-retardant and anticorrosive coating as claimed in any one of claims 1 to 6, characterized in that, The specific preparation steps are as follows: According to the weight ratio of the formulation, the waterborne epoxy emulsion 20-50 parts, the polystyrene-silicon carbide composite material 0.5-10 parts, the flame-retardant filler 30-50 parts, the titanium dioxide 1-5 parts, the aluminum hydroxide 1-5 parts, the talc 1-5 parts, the dispersant 0.5-3 parts, half of the defoaming agent 0.5-3 parts, the leveling agent 0-3 parts, half of the film-forming aid 1-10 parts, and the water 0-10 parts are mixed, and dispersed at a speed of 2000-3000 r / min for 15-30 min; The film-forming aid and the defoaming agent are each supplemented once, and the stirring speed is adjusted to 1000-1500 r / min for 8-14 min to obtain the A component; The amine curing agent is stirred uniformly to obtain the B component; The A component and the B component are uniformly mixed to obtain the intumescent fireproof and anticorrosive paint that can be used for coating.

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