Fireproof anticorrosive coating, its preparation method and coating

Abstract

The present disclosure relates to a fire-retardant and corrosion-resistant coating and a preparation method and coating thereof. The fire-retardant and corrosion-resistant coating comprises, in mass parts, a modified epoxy resin, ammonium polyphosphate, a carbon-forming agent, a foaming agent, a heat-resistant pigment filler, modified graphene oxide, a defoaming agent, a leveling agent and a dispersing active agent; the prepared coating has excellent fire-retardant performance and corrosion resistance.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of fireproof coating, in particular to a fireproof and anticorrosive coating, a preparation method thereof and a coating. BACKGROUND

[0002] Steel structure has been widely used in outdoor construction industry due to its high strength, small weight, low cost, easy installation, good seismic performance, recyclability and other comprehensive advantages. However, outdoor steel structure also faces some problems. The surface of outdoor steel structure is prone to oxidation and corrosion after being subjected to seasonal and diurnal temperature changes and wind, rain and sun, and the corrosion rate can reach 1mm-2mm per year. After 4-5 years of corrosion, the steel structure will be completely scrapped. At the same time, steel is a good conductor of heat and the mechanical strength of steel will decrease at high temperature. The temperature in a fire scene is about 800-1200℃. Without fire protection, the temperature of the steel structure can reach about 500℃ in a few minutes, and its mechanical strength will rapidly decrease to 40%-50%, thereby losing the load bearing function and appearing distortion or even collapse, causing significant property loss and casualties.

[0003] Therefore, it is important and necessary to design a fireproof and anticorrosive integrated coating to avoid the complicated problem of multiple functional coating layers and to meet the demand of simultaneously preventing fire and corrosion of steel structure. SUMMARY

[0004] To solve at least one of the above technical problems, the present disclosure provides a fireproof and anticorrosive coating, a preparation method thereof and a coating.

[0005] As one aspect, the present disclosure provides a fireproof and anticorrosive coating, comprising, by mass fraction: modified epoxy resin 20-30%, ammonium polyphosphate 20-30%, carbonization agent 10-15%, foaming agent 16-24%, heat-resistant pigment filler 5-10%, modified graphene oxide 2.5-5%, defoaming agent 0.1-1%, leveling agent 0.1-1%, and dispersing active agent 0.1-1%.

[0006] As another aspect, the present disclosure provides a preparation method of the above-mentioned coating, comprising: uniformly mixing modified epoxy resin, modified graphene oxide, foaming agent, carbonization agent, heat-resistant pigment filler, defoaming agent, leveling agent and dispersing active agent to obtain a mixture; adding ammonium polyphosphate and solvent to the mixture to obtain the coating; wherein the mass ratio of the carbonization agent to the foaming agent comprises (1.5-1.9):1, preferably 1.7:1; and / or the mass ratio of the ammonium polyphosphate to the foaming agent comprises (1.7-2.1):1, preferably 1.9:1.

[0007] As still another aspect, the present disclosure provides a coating, wherein the coating comprises the above-mentioned coating or the coating obtained by the above-mentioned preparation method.

[0008] As a further aspect, the present disclosure provides a method for preparing the coating as described above, comprising: mixing the coating as described above or the coating obtained by the method as described above with a curing agent uniformly, and then brushing the mixture on the surface of the metal coating area; wherein the mass ratio of the coating to the curing agent comprises (4.5-6):1; and / or the curing agent is selected from polyamide resin.

[0009] The technical solution provided by the embodiments of the present disclosure has the following advantages:

[0010] The modified epoxy resin is used as the base resin in the present disclosure, which can provide the coating with good film-forming performance and good corrosion resistance, and the compatibility between the resin base and the fireproof filler is good, which can be compounded with the filler to form a corrosion and fireproof integrated coating with excellent performance, avoiding the complicated problem of supporting construction of multiple functional coatings. The fireproof filler includes ammonium polyphosphate, carbon-forming agent, foaming agent and heat-resistant pigment filler. In addition, by adding the modified graphene oxide with excellent expansion performance in the fireproof coating, the expansion effect of the fireproof carbon layer can be improved, the amount of fireproof filler can be reduced without reducing the fireproof effect of the coating. It meets the concept of economic saving and green environmental protection. BRIEF DESCRIPTION OF DRAWINGS

[0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and serve to explain the principles of the present disclosure together with the specification.

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0013] Figure 1 The appearance of the coating plate after the fireproof performance test of the S-1 coating of the embodiments of the present disclosure;

[0014] Figure 2 The appearance structure of the coating plate after the fireproof performance test of the S-2 coating of the embodiments of the present disclosure;

[0015] Figure 3 The appearance structure of the coating plate after the fireproof performance test of the S-3 coating of the embodiments of the present disclosure;

[0016] Figure 4 The appearance structure of the coating plate after the fireproof performance test of the D-1 coating of the embodiments of the present disclosure;

[0017] Figure 5The steel plate back temperature-time curve diagram of the fire resistance limit test of the S-1, S-2, S-3 coating plate of the embodiment of the present disclosure;

[0018] Figure 6 The steel plate back temperature-time curve diagram of the fire resistance limit test of the S-4, S-5, S-6, S-7 coating plate of the embodiment of the present disclosure;

[0019] Figure 7 The steel plate back temperature-time curve diagram of the fire resistance limit test of the D-1 coating of the embodiment of the present disclosure;

[0020] Figure 8 The steel plate back plate appearance structure after the fire resistance performance test of the S-2, D-1 coating of the embodiment of the present disclosure;

[0021] Figure 9 The fire resistance limit diagram of different fireproof fillers of the embodiment of the present disclosure;

[0022] Figure 10 The steel plate back plate appearance structure after the salt water corrosion performance test of the S-2 coating of the embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] In order to enable the above-mentioned purposes, features and advantages of the present disclosure to be more clearly understood, the schemes of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0024] In the following description, many specific details are set forth in order to fully understand the present disclosure, but the present disclosure can also be implemented in other different manners from those described herein; obviously, the embodiments in the specification are only some of the embodiments of the present disclosure, not all the embodiments.

[0025] The resin base has good corrosion resistance, so that the coating can play a role in corrosion protection. When encountering flame impact, the fireproof filler can play a protective role in fireproofing and heat insulation, and can effectively delay the development of fire and prevent the spread of flame. Among them, the intumescent coating can form its own several times of heat insulation carbon layer in the fire, which is more economical than the non-intumescent coating and is more conducive to construction.

[0026] According to an embodiment of the present disclosure, a fireproof and anticorrosive coating is provided, including, in mass parts, 20-30% of modified epoxy resin, 20-30% of ammonium polyphosphate, 10-15% of carbonization agent, 16-24% of foaming agent, 5-10% of heat-resistant pigment filler, 2.5-5% of modified graphene oxide, 0.1-1% of defoaming agent, 0.1-1% of leveling agent, and 0.1-1% of dispersing active agent. For example, the modified epoxy resin is selected from any one of 21.6%, 23.9%, 25.9%, 27.9%, and 29.8% in mass parts; the ammonium polyphosphate is selected from any one of 22.9%, 24.6%, 26.9%, 28.2%, and 29.6% in mass parts; the carbonization agent is selected from any one of 10.3%, 11.6%, 12.9%, 13.8%, and 14.9% in mass parts; the foaming agent is selected from any one of 17.6%, 19.8%, 21.9%, 22.8%, and 23.8% in mass parts; the heat-resistant pigment filler is selected from any one of 5.3%, 6.9%, 7.6%, 8.3%, and 9.8% in mass parts; the modified graphene oxide is selected from any one of 2.9%, 3.2%, 3.9%, 4.3%, and 4.9% in mass parts; the defoaming agent is selected from any one of 0.23%, 0.46%, 0.69%, 0.73%, and 0.98% in mass parts; the leveling agent is selected from any one of 0.29%, 0.48%, 0.59%, 0.82%, and 0.96% in mass parts; and the dispersing active agent is selected from any one of 0.39%, 0.42%, 0.69%, 0.73%, and 0.99% in mass parts.

[0027] The present disclosure uses modified epoxy resin as a base resin, which can provide the coating with good film-forming performance and good corrosion resistance, and the compatibility between the resin base and the fireproof filler is good, which can be compounded with the filler to form a fireproof and anticorrosive coating with excellent performance. In addition, by adding modified graphene oxide with excellent expansion performance in the coating, the expansion effect of the fireproof carbon layer can be improved, the amount of fireproof filler can be reduced, and the fireproof effect of the coating is not reduced. It meets the concept of economic saving and green environmental protection.

[0028] In some embodiments of the present disclosure, the preparation method of the modified epoxy resin includes: pre-polymerization of bisphenol A type epoxy resin and silane coupling agent to obtain a pre-polymer; and reaction of the pre-polymer and organic silicon to obtain the modified epoxy resin.

[0029] In some embodiments of the present disclosure, wherein the preparation method of the modified epoxy resin, the temperature of the prepolymerization reaction comprises 70-100℃, the time comprises 2.5-4h, for example, the reaction temperature is selected from any one value comprising 72℃, 79℃, 86℃, 91℃, 98℃, and the reaction time is selected from any one value comprising 2.7h, 2.9h, 3.1h, 3.6h, 3.9h; and / or, the temperature of the reaction comprises 80-160℃, the time comprises 3-5h, for example, the reaction temperature is selected from any one value comprising 82℃, 99℃, 116℃, 129℃, 158℃, and the reaction time is selected from any one value comprising 3.2h, 3.9h, 4.1h, 4.6h, 4.9h.

[0030] In some embodiments of the present disclosure, wherein the preparation method of the modified epoxy resin, the catalyst of the prepolymerization reaction comprises one or more of dibutyltin laurate, dibutyltin, stannous octoate; and / or, the silicone is selected from one or both of 30cs hydroxyl silicone oil, 300cs hydroxyl silicone oil; and / or, the mass ratio of the bisphenol A type epoxy resin to the silane coupling agent comprises 1:(0.02-0.06); and / or, the mass ratio of the prepolymer to the silicone comprises 1:(0.1-0.2). For example, the mass ratio of the bisphenol A type epoxy resin to the silane coupling agent is selected from any one mass ratio comprising 1:0.028, 1:0.031, 1:0.039, 1:0.043, 1:0.051, 1:0.059; and / or, the mass ratio of the prepolymer to the silicone comprises any one mass ratio comprising 1:0.11, 1:0.13, 1:0.16, 1:0.18, 1:0.19.

[0031] In some embodiments of the present disclosure, the synthesis of the modified epoxy resin comprises the following steps: the bisphenol A type epoxy resin is added to an alcohol-ether mixed solvent, stirred and dissolved, and then a catalyst is added. The temperature is raised to 80-160℃, the silicone is added dropwise into the epoxy resin solution, and the reaction is carried out for 3-5h to obtain the modified epoxy resin. For example, the reaction temperature is selected from any one value comprising 83℃, 98℃, 126℃, 139℃, 159℃, and the reaction time is selected from any one value comprising 3.3h, 3.7h, 4.3h, 4.6h, 4.8h.

[0032] In some embodiments of the present disclosure, wherein the preparation method of the modified graphene oxide comprises: filtering the suspension of graphene oxide and zinc acetate to obtain a filtrate; and maintaining the filtrate at 150-350℃ for 3-5h to prepare the modified graphene oxide. For example, the reaction temperature is selected from any one value comprising 163℃, 198℃, 256℃, 289℃, 329℃, and the reaction time is selected from any one value comprising 3.1h, 3.9h, 4.2h, 4.7h, 4.9h.

[0033] In some embodiments of the present disclosure, the method for preparing the modified graphene oxide comprises the following steps: adding graphene oxide into zinc acetate solution, ultrasonic mixing for a period of time, preferably 15-30 min, for example, the ultrasonic time is selected from any one of 16 min, 19 min, 23 min, 26 min, 29 min; filtering the suspension, rinsing the filtrate with deionized water, placing the filtrate in a constant temperature oven at 150-350℃ for a period of time to obtain the modified graphene oxide, for example, the temperature is selected from any one of 169℃, 215℃, 269℃, 298℃, 316℃, 348℃.

[0034] In some embodiments of the present disclosure, the temperature of the oven for the modified graphene oxide is set to 250℃.

[0035] In some embodiments of the present disclosure, the solid content in the paint comprises 50-70%, preferably 66.6%. For example, the solid content is selected from any one of 56.6%, 58.9%, 61.6%, 65.9%, 68.6%, 69.6%.

[0036] In some embodiments of the present disclosure, the heat-resistant pigment comprises one or more of titanium dioxide, talc, white carbon black; and / or the carbon-forming agent is selected from one or more of melamine, polyurea, melamine, dicyandiamide; and / or the foaming agent is selected from one or more of pentaerythritol, dipentaerythritol.

[0037] In some embodiments of the present disclosure, the defoaming agent comprises BYK-085 produced by BYK Chemical.

[0038] In some embodiments of the present disclosure, the leveling agent comprises EFKA-3777 produced by BASF, Germany.

[0039] In some embodiments of the present disclosure, the dispersing active agent comprises BYK-220S produced by BYK Chemical.

[0040] According to an embodiment of the present disclosure, a preparation method of the coating is provided, comprising: uniformly mixing the modified epoxy resin, the modified graphene oxide, the foaming agent, the carbon forming agent, the heat-resistant pigment filler, the defoaming agent, the leveling agent, and the dispersing active agent to obtain a mixture; and adding the ammonium polyphosphate and the solvent into the mixture to obtain the coating; wherein the mass ratio of the carbon forming agent to the foaming agent comprises (1.5-1.9):1, for example, the mass ratio of the carbon forming agent to the foaming agent is selected from any one of 1.51:1, 1.62:1, 1.71:1, 1.79:1, 1.88:1; preferably 1.7:1; and / or the mass ratio of the ammonium polyphosphate to the foaming agent comprises (1.7-2.1):1, the mass ratio of the ammonium polyphosphate to the foaming agent is selected from any one of 1.79:1, 1.85:1, 1.91:1, 1.99:1, 2.09:1; preferably 1.9:1.

[0041] In some embodiments of the present disclosure, the solvent comprises one or more of xylene, acetone, or n-butanol.

[0042] In some embodiments of the present disclosure, the ammonium polyphosphate has a degree of polymerization greater than 1000.

[0043] According to an embodiment of the present disclosure, a coating is provided, wherein the coating comprises the coating or the coating prepared by the preparation method described above.

[0044] According to an embodiment of the present disclosure, a preparation method of the coating is provided, comprising: uniformly mixing the coating described above or the coating prepared by the preparation method described above with the curing agent, and then brushing the mixture on the surface of the metal coating area; wherein the mass ratio of the coating to the curing agent comprises (4.5-6):1; and / or the curing agent is selected from polyamide resin, for example, the mass ratio of the coating to the curing agent is selected from any one of 4.8:1, 5.26:1, 5.49:1, 5.68:1, 5.79:1, 5.96:1.

[0045] In some embodiments of the present disclosure, a preparation method of the coating comprising the coating described above comprises the following steps: uniformly mixing the coating described above with the curing agent in a mass ratio of (4.5-6):1, and then brushing the mixture on the surface of the metal coating area to form the coating. For example, the mass ratio of the coating to the curing agent comprises any one of 4.6:1, 4.9:1, 5.1:1, 5.3:1, 5.7:1, 5.9:1.

[0046] In some embodiments of the present disclosure, the curing agent is preferably polyamide resin, and more preferably comprises one or more of 650 polyamide resin and 651 polyamide resin.

[0047] In order to further illustrate the effect of the present disclosure, specific embodiments are described below.

[0048] (I) Preparation of the coating

[0049] Example 1

[0050] Preparation of the silicone-modified epoxy resin

[0051] Take 50 g of E44 epoxy resin and 17 g of a mixed solution of xylene and cyclohexanone (ratio 1:1) in a flask, set the magnetic stirring speed to 300 r / min to completely dissolve the epoxy resin, heat the oil bath to 80°C, add 0.4 g of dibutyl tin laurate and 1.5 g of KH-550, and react for 3 h. Then heat the oil bath to 155°C, take 5 g of small molecule hydroxyl silicone oil (viscosity 30 cs) in a constant pressure dropping funnel, and add the small molecule hydroxyl silicone oil drop by drop into the solution containing the epoxy resin at a speed of 0.1 ml / 1 s, and heat at 155°C for 5 h under magnetic stirring to obtain a milky white epoxy resin modified product.

[0052] Example 2

[0053] Preparation of intumescent fire-retardant coating S-1

[0054] Take 0.3 g of modified graphene oxide and add it to 30 g of modified epoxy resin solution (solid content 66.6%), stir to mix, then add 8.5 g of pentaerythritol, 14.5 g of melamine, 1.2 g of titanium white, 0.05 g of BYK-085 defoamer, 0.05 g of EFKA-3777 leveling agent, and 0.08 g of BYK-220S active dispersant. After rapid stirring to fully disperse, add 16 g of ammonium polyphosphate (polymerization degree 1000), continue stirring for 3 min, and then add a mixed solvent of xylene and acetone to make the solid content of the entire coating 66.6%, and obtain intumescent fire-retardant coating S-1.

[0055] Example 3

[0056] Preparation of intumescent fire-retardant coating S-2

[0057] Take 0.3 g of modified graphene oxide and add it to 30 g of modified epoxy resin solution (solid content 66.6%), stir to mix, then add 10.2 g of pentaerythritol, 17.2 g of melamine, 1.2 g of titanium white, 0.05 g of BYK-085 defoamer, 0.05 g of EFKA-3777 leveling agent, and 0.08 g of BYK-220S active dispersant. After rapid stirring to fully disperse, add 19.4 g of ammonium polyphosphate (polymerization degree 1000), continue stirring for 3 min, and then add a mixed solvent of xylene and acetone to make the solid content of the entire coating 66.6%, and obtain intumescent fire-retardant coating S-2.

[0058] Example 4

[0059] Preparation of intumescent fire-retardant coating S-3

[0060] Take 0.3 g of modified graphene oxide, add it to 30 g of modified epoxy resin solution (solid content 66.6%), stir and mix well, then add 11.9 g of pentaerythritol, 20.3 g of melamine, 1.2 g of titanium white powder, 0.05 g of BYK-085 defoamer, 0.05 g of EFKA-3777 leveling agent, and 0.08 g of BYK-220S active dispersant. After rapid stirring to fully disperse, add 22.4 g of ammonium polyphosphate (polymerization degree 1000), continue stirring for 3 min, then add a mixed solvent of xylene and acetone to make the solid content of the entire coating 66.6%, and the intumescent fire-retardant coating S-3 is obtained.

[0061] Example 5

[0062] Preparation of intumescent fire-retardant coating S-4

[0063] Take 0.3 g of modified graphene oxide, add it to 30 g of modified epoxy resin solution (solid content 66.6%), stir and mix well, then add 11.9 g of pentaerythritol, 20.3 g of melamine, 1.2 g of titanium white powder, 0.05 g of BYK-085 defoamer, 0.05 g of EFKA-3777 leveling agent, and 0.08 g of BYK-220S active dispersant. After rapid stirring to fully disperse, add 22.4 g of ammonium polyphosphate (polymerization degree 1000), continue stirring for 3 min, then add a mixed solvent of xylene and acetone to make the solid content of the entire coating 66.6%, and the intumescent fire-retardant coating S-3 is obtained.

[0064] Example 6

[0065] Preparation of intumescent fire-retardant coating S-5

[0066] Take 0.3 g of modified graphene oxide, add it to 30 g of modified epoxy resin solution (solid content 66.6%), stir and mix well, then add 11.9 g of pentaerythritol, 20.3 g of melamine, 1.2 g of titanium white powder, 0.05 g of BYK-085 defoamer, 0.05 g of EFKA-3777 leveling agent, and 0.08 g of BYK-220S active dispersant. After rapid stirring to fully disperse, add 22.4 g of ammonium polyphosphate (polymerization degree 1000), continue stirring for 3 min, then add a mixed solvent of xylene and acetone to make the solid content of the entire coating 66.6%, and the intumescent fire-retardant coating S-3 is obtained.

[0067] Example 7

[0068] Preparation of intumescent fire-retardant coating S-6

[0069] Take 0.3 g of modified graphene oxide, add 30 g of modified epoxy resin solution (solid content 66.6%), stir and mix, then add 11.9 g of pentaerythritol, 20.3 g of melamine, 1.2 g of titanium white powder, 0.05 g of BYK-085 defoamer, 0.05 g of EFKA-3777 leveling agent, 0.08 g of BYK-220S active dispersant. After rapid stirring to make it fully dispersed, add 17 g of ammonium polyphosphate (polymerization degree 1000), continue stirring for 3 min, then add a mixed solvent of xylene and acetone to make the solid content of the whole coating 66.6%, and the intumescent fire retardant coating S-6 is obtained.

[0070] Example 8

[0071] Preparation of intumescent fire retardant coating S-7

[0072] Take 0.3 g of modified graphene oxide, add 30 g of modified epoxy resin solution (solid content 66.6%), stir and mix, then add 11.9 g of pentaerythritol, 20.3 g of melamine, 1.2 g of titanium white powder, 0.05 g of BYK-085 defoamer, 0.05 g of EFKA-3777 leveling agent, 0.08 g of BYK-220S active dispersant. After rapid stirring to make it fully dispersed, add 17 g of ammonium polyphosphate (polymerization degree 1000), continue stirring for 3 min, then add a mixed solvent of xylene and acetone to make the solid content of the whole coating 66.6%, and the intumescent fire retardant coating S-6 is obtained.

[0073] Comparative Example 1

[0074] Preparation of silicone modified epoxy resin

[0075] Take 50 g of E44 epoxy resin and 17 g of a mixed solution of xylene and cyclohexanone (ratio 1:1) in a flask, set the magnetic stirring speed to 300 r / min to make the epoxy resin fully dissolved, heat the oil bath to 80℃, add 0.4 g of dibutyl tin laurate and 1.5 g of KH-550, and react for 3 h. Then heat the oil bath to 155℃, take 5 g of hydroxyl silicone oil (viscosity 300 cs) in a constant pressure dropping funnel, and add the small molecule hydroxyl silicone oil drop by drop into the solution containing the epoxy resin at a speed of 0.1 ml / 1 s, and heat and stir at 155℃ for 5 h to obtain a layered product.

[0076] Comparative Example 2

[0077] Preparation of intumescent fire retardant coating D-1

[0078] This comparative example does not add modified graphene oxide to prepare an intumescent fire retardant coating, and the steps are as follows:

[0079] Take 30 g of modified epoxy resin solution (66.6% solid content), add 10.2 g of pentaerythritol, 17.2 g of melamine, 1.2 g of titanium white powder, 0.05 g of BYK-085 defoamer, 0.05 g of EFKA-3777 leveling agent, and 0.08 g of BYK-220S active dispersant. After rapid stirring to disperse them thoroughly, add 19.4 g of ammonium polyphosphate (polymerization degree 1000), continue stirring for 3 min, and then add a mixed solvent of xylene and acetone to make the solid content of the coating 66.6%, and the intumescent fireproof coating D-1 is obtained.

[0080] (II) Preparation of the coating

[0081] Take S-1, S-2, S-3, S-4, S-5, S-6, S-7, D-1 coating respectively, add 30 g of 650 polyamide curing agent (diluted to 66.6% solid content with a mixed solution of xylene and cyclohexanone), and coat on the surface of a steel plate. Place it at room temperature for 4 days. The material is completely cured to obtain the corresponding coating of the coating.

[0082] (III) Fire resistance limit time test

[0083] The corresponding coating prepared from S-1, S-2, S-3, S-4, S-5, S-6, S-7, D-1 coating respectively is subjected to fire resistance limit time test, and the specific test method is as follows:

[0084] Fix the sample plate above the iron ring of the iron stand, with the coating facing down. The vertical distance between the alcohol burner nozzle and the sample plate is 6.5 cm. A layer of thermal insulation cotton is covered on the back of the steel plate to prevent the heat from the steel plate from being quickly dissipated. The thermocouple is tightly attached to the top of the steel plate. When the flame temperature of the alcohol burner reaches 1000℃, it is moved directly below the test steel plate, so that the flame directly burns the coating, and the timing starts. Record once every 5 min. According to the national standard GB14907-2018, the time when the back temperature of the steel plate reaches about 500℃ is taken as the fire resistance limit of the fireproof coating, and the steel plate back temperature-time curve is drawn. After 2 hours of final calcination, the appearance change of the steel plate coating before and after heating is photographed.

[0085] The test results are as follows: Figure 1 The appearance of the S-1 coating after the fireproof performance test; Figure 2 The appearance of the S-2 coating after the fireproof performance test; Figure 3 The appearance of the S-3 coating after the fireproof performance test; Figure 4 The appearance of the D-1 coating after the fireproof performance test; Figure 5 The steel plate back temperature-time curve of the S-1, S-2, and S-3 coatings after the fire resistance limit test; Figure 6The back temperature-time curves of steel plates coated with S-4, S-5, S-6, and S-7 paints are shown in the fire resistance limit test. Figure 7 The graph shows the back temperature-time curve of the steel plate during the fire resistance limit test of D-1 coating. Figure 8 The appearance and structure of the steel plate back panel after the fire resistance performance test of S-2 and D-1 coatings; Figure 9 Fire resistance rating diagrams for different fire-retardant filler ratios; Figure 10 This is a diagram showing the appearance and structure of the steel plate back panel after the salt water corrosion resistance test of coating S-2.

[0086] (III) Saltwater Corrosion Resistance Test

[0087] The salt water corrosion resistance of the coating prepared by the S-2 coating with the best fire resistance was tested by the salt water immersion method. A saturated sodium chloride solution at room temperature was prepared, and the steel plate coated with the coating was immersed in the saturated salt water for about 14 days. The surface condition of the coating and the corrosion of the steel plate were observed.

[0088] Test results are as follows Figure 10 As shown, where, Figure 10 This is a diagram showing the appearance and structure of the steel plate back panel after the salt water corrosion resistance test of coating S-2.

[0089] Analysis of the above test results leads to the following conclusions:

[0090] (1) Figure 1 The morphology of the coated board after the fire resistance performance test of S-1 coating.

[0091] like Figure 1 As shown, the fire resistance limit test of the coating was conducted. The appearance and structure of the coated panel after a 2-hour fire resistance test with S-1 coating are as follows: Figure 1 It can be seen that if the amount of film-forming resin is too small, the expansion of the expanded carbon layer will be uneven after the fire resistance test, which will affect the heat insulation and fireproof performance of the coating.

[0092] (2) Figure 2 The appearance and structure of the coated panel after the fire resistance performance test of S-2 coating.

[0093] like Figure 2 As shown, the fire resistance limit test of the coating was carried out. The figure shows the appearance of the coating board after 2 hours of fire resistance test of S-2 coating. Due to the coordinated ratio of fire retardant filler and film-forming resin, a good expanded carbon layer was formed after the fire resistance test.

[0094] (3) Figure 3 The appearance and structure of the coated panel after the fire resistance performance test of S-3 coating.

[0095] like Figure 3As shown, the paint is tested for fire resistance limit, and the appearance of the coating plate of S-3 paint after 2h fire resistance test is shown. Due to the addition of too little fireproof filler, the paint does not form a fluffy carbon layer at high temperature, and does not achieve the role of forming a heat insulation layer, which does not meet the fireproofing requirements.

[0096] (4) Figure 4 The appearance and structure of the coating plate of D-1 paint after fireproofing performance test are shown.

[0097] As Figure 4 shown, the paint is tested for fire resistance limit, and the appearance of the coating plate of D-1 paint after 2h fire resistance test is shown. Compared with S-2, no modified graphene oxide is added, the expansion performance of the carbon layer is poor, and the fireproofing requirements cannot be better met.

[0098] (5) Figure 5 The steel plate back temperature-time curve diagram of the fire resistance limit test of the coating plates of S-1, S-2 and S-3 paints is shown.

[0099] As Figure 5 shown, the paint is tested for fire resistance limit: taking the test time as the horizontal axis and the back plate temperature as the vertical axis, the steel plate back temperature-time curve diagram of the fire resistance limit test of the coating plates of S-1, S-2 and S-3 paints is drawn. As can be seen from the diagram, the back plate temperature of the coating plate of S-3 paint exceeds 500℃ when burning for 65min, which does not meet the requirements. The temperature of the coating plates of S-1 and S-2 paints rises rapidly to a certain temperature and then fluctuates within a certain range, and the limit temperature is not reached within 2h, which meets the requirements of fireproofing paint. The back plate temperature of the coating plate of S-1 paint is always stable within 250℃, and the fireproofing performance is the best.

[0100] (6) Figure 6 The steel plate back temperature-time curve diagram of the fire resistance limit test of the coating plates of S-4, S-5, S-6 and S-7 paints is shown.

[0101] As Figure 6 shown, the paint is tested for fire resistance limit: taking the test time as the horizontal axis and the back plate temperature as the vertical axis, the steel plate back temperature-time curve diagram of the fire resistance limit test of the coating plates of S-4, S-5, S-6 and S-7 paints is drawn. As can be seen from the diagram, the fire resistance time of the above steel plate does not reach 2h, and the fireproofing performance of the paint is poor.

[0102] (7) Figure 7 The steel plate back temperature-time curve diagram of the fire resistance limit test of D-1 paint is shown.

[0103] As Figure 7As shown, the fire resistance test was carried out on the coating: the fire resistance test steel plate back temperature-time curve of the D-1 coating was plotted with the test time as the horizontal axis and the back plate temperature as the vertical axis. The back plate temperature had a tendency to flatten at 15 min, but the carbon layer had a small expansion degree, the back plate temperature increased sharply at 30 min, and the back plate temperature exceeded the fire resistance limit temperature at 40 min, and the fireproof effect of the coating was poor.

[0104] (8) Figure 8 The steel plate back plate appearance structure after the fireproof performance test of the S-2 and D-1 coatings.

[0105] As Figure 8 shown, Fig. S1 is the steel plate back plate appearance after the fireproof performance test of the D-1 coating; and Fig. S2 is the back plate appearance after the fireproof performance test of the S-2 coating. As can be seen from the figures, the back plate of the steel plate coated with the D-1 coating appeared oxidation discoloration after the fireproof test, indicating that the D-1 coating cannot well insulate heat sources, and the S-2 coating added with modified graphene has better fireproof performance, and after the fireproof performance test, the back plate has almost no obvious change.

[0106] (9) Figure 9 The fire resistance limit graph of different fireproof fillers.

[0107] As Figure 9 shown, the surface graph was plotted with the proportions of the components of the fireproof filler as the X and Y axes and the fire resistance limit time as the Z axis. Different proportions of the fillers have great differences in fireproof performance. When the proportions of melamine and pentaerythritol are 1.7 and the proportion of ammonium polyphosphate and pentaerythritol is 1.9, the fireproof performance is best, and the fire resistance limit time reaches the highest of 2.84 h, meeting the fireproof demand. The fire resistance limit time of S4 to S7 examples does not exceed 30 min, and the fireproof effect is poor.

[0108] (10) Figure 10 The steel plate back plate appearance structure graph after the salt water corrosion resistance performance test of the coating S-2.

[0109] As Figure 10 shown, it can be seen from the figure that the surface of the steel plate coated with the S-1 coating has almost no change after the salt water corrosion resistance test, indicating that the coating has good salt water corrosion resistance.

[0110] In summary, the intumescent fireproof and corrosion-resistant coating provided by the embodiments of the present disclosure comprises modified epoxy resin, ammonium polyphosphate, carbonizing agent, foaming agent, heat-resistant pigment filler, modified graphene oxide, defoaming agent, leveling agent, dispersing active agent, and solvent. The coating is compounded by physical blending and cured into a coating layer by a curing agent. The obtained coating layer has excellent fireproof performance and corrosion resistance, and can meet the demand of outdoor steel structure fireproofing and corrosion resistance.

[0111] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0112] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fireproof and anticorrosive paint, characterized in that, comprising, in parts by mass, 20-30% of modified epoxy resin, 20-30% of ammonium polyphosphate, 10-15% of carbonization agent, 16-24% of foaming agent, 5-10% of heat-resistant pigment filler, 2.5-5% of modified graphene oxide, 0.1-1% of defoaming agent, 0.1-1% of leveling agent, and 0.1-1% of dispersing active agent; a preparation method of the modified epoxy resin comprising, pre-polymerization of bisphenol A type epoxy resin and silane coupling agent at 70-100℃ for 2.5-4h to obtain a pre-polymer, and reaction of the pre-polymer and silicone at 80-160℃ for 3-5h to obtain the modified epoxy resin; a preparation method of the modified graphene oxide comprising, filtration of a suspension of graphene oxide and zinc acetate to obtain a filtrate, and keeping the filtrate at 150-350℃ for 3-5h to obtain the modified graphene oxide. in the preparation method of the modified epoxy resin, 2. The coating of claim 1, wherein, the catalyst for the pre-polymerization reaction comprises one or more of dibutyl tin and stannous octoate; and / or, the silicone is selected from one or both of 30cs hydroxyl silicone oil and 300cs hydroxyl silicone oil; and / or, the mass ratio of the bisphenol A type epoxy resin to the silane coupling agent is 1:(0.02-0.06); and / or, the mass ratio of the pre-polymer to the silicone is 1:(0.1-0.2). 3.The paint of claim 1, characterized in that, the solid content of the paint is 50-70%. 4.The paint of claim 1, characterized in that, the heat-resistant pigment filler comprises one or more of titanium white, talcum powder and white carbon black; and / or, the carbonization agent is selected from one or more of polyurea, melamine and dicyandiamide; and / or, the foaming agent is selected from one or more of pentaerythritol and di-pentaerythritol; and / or, the solid content of the paint is 66.6%. 5.A preparation method of the paint of any one of claims 1-4, comprising: uniformly mixing the modified epoxy resin, the modified graphene oxide, the foaming agent, the carbonization agent, the heat-resistant pigment filler, the defoaming agent, the leveling agent and the dispersing active agent to obtain a mixture; adding ammonium polyphosphate and solvent to the mixture to obtain the paint; wherein, the mass ratio of the carbonization agent to the foaming agent is (1.5-1.9):1; and / or, the mass ratio of the ammonium polyphosphate to the foaming agent is (1.7-2.1):

1. the mass ratio of the carbonization agent to the foaming agent is 1.7:1; 6. The production method according to claim 5, characterized by, and / or, the mass ratio of the ammonium polyphosphate to the foaming agent is 1.9:

1. 7.A coating layer, characterized in that, the coating layer comprises the paint of any one of claims 1-4 or the paint obtained by the preparation method of any one of claims 5-6. 8.A preparation method of the coating layer of claim 7, comprising: uniformly mixing the paint of any one of claims 1-4 or the paint obtained by the preparation method of any one of claims 5-6 with a curing agent, and then brushing the mixture on the surface of a metal coating area; wherein, the mass ratio of the paint to the curing agent is (4.5-6):

1. ​ And / or, the curing agent comprises a polyamide resin.

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