An epoxy fire-retardant coating and its preparation method

Abstract

This invention proposes an epoxy fire-retardant coating and its preparation method, belonging to the field of coating technology. It comprises component A and component B. By weight, component A includes 20-30 parts of silane-modified phenolic epoxy resin, 5-9 parts of epoxy reactive diluent, 5-10 parts of aluminum hydroxide, 5-8 parts of melamine, 25-48 parts of ammonium polyphosphate, 0.5-1 parts of expanded graphite, 6-8 parts of alumina fiber, 3-10 parts of barium sulfate, 3-5 parts of modified alumina, and 2-5 parts of titanium dioxide; component B includes 40-50 parts of phenolic amine and 50-60 parts of 1,3-cyclohexanedimethylamine. The coating provided by this invention combines fire-retardant properties, corrosion resistance in marine environments, and room-temperature curing properties, and is applicable to fire-retardant and corrosion-resistant coatings for steel structures in offshore oil and gas platforms, petrochemical plant facilities, etc.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to an epoxy fire-retardant coating and its preparation method. Background Technology

[0002] Fire-retardant coatings for steel structures include two types: intumescent and non-intumescent. When intumescent fire-retardant coatings are exposed to fire and heat, the carbonizing agent undergoes esterification and dehydration to form carbon under the action of a catalyst. The carbides then form a closed, three-dimensional honeycomb-like carbonized layer under the action of the inert gas released from the decomposition of the foaming agent. This carbonized layer can seal the protected substrate, prevent gas diffusion, and at the same time prevent external oxygen from diffusing to the surface of the substrate, thus achieving the purpose of fireproofing and heat insulation.

[0003] Current intumescent fire-retardant coatings for steel structures are composed of organic and inorganic base materials, fire-retardant additives, catalysts, foaming agents, etc., and have good fire-retardant and flame-retardant properties. However, the fire-retardant coatings currently prepared cannot simultaneously possess anti-corrosion properties and fire-retardant functions against olefin fires, thus limiting the application areas of fire-retardant coatings. Summary of the Invention

[0004] The purpose of this invention is to propose an epoxy fire-retardant coating and its preparation method. The preparation method is simple and has good flame retardant, fireproof, high strength and corrosion resistance properties. It combines the fireproof performance of olefin fires, the corrosion resistance performance in marine environments and the room temperature curing performance. It can be applied to the fireproof and corrosion retardant coating of steel structures in olefin fires such as offshore oil and gas platforms and petrochemical plant units, and has broad application prospects.

[0005] The technical solution of this invention is implemented as follows:

[0006] This invention provides an epoxy fire-retardant coating, comprising component A and component B. By weight, component A comprises 20-30 parts of silane-modified phenolic epoxy resin, 5-9 parts of epoxy reactive diluent, 5-10 parts of aluminum hydroxide, 5-8 parts of melamine, 25-48 parts of ammonium polyphosphate, 0.5-1 parts of expanded graphite, 6-8 parts of alumina fiber, 3-10 parts of barium sulfate, 3-5 parts of modified alumina, and 2-5 parts of titanium dioxide.

[0007] By weight, component B comprises 40-50 parts of phenolic amine and 50-60 parts of 1,3-cyclohexanedimethylamine.

[0008] As a further improvement of the present invention, the preparation of the silane-modified phenolic epoxy resin includes:

[0009] By weight, add 2-5 parts of methylphenyl intermediate silanol, 90-95 parts of phenolic epoxy resin and 3-5 parts of silane coupling agent to the reaction vessel.

[0010] Stir and heat to 120-130℃, stirring until the epoxy value of the system is 0.4-0.54 (100g / g) and the viscosity is 3500-6500 (25℃ mPa.s). Stop stirring and discharge the material.

[0011] As a further improvement of the present invention, the viscosity of the methylphenyl intermediate silanol is 20-200 (25℃ mPa.s), and the viscosity of the phenolic epoxy resin is 3500-6000 (25℃ mPa.s); the silane coupling agent is γ-glycidoxypropyltrimethoxysilane. KH560 has excellent surface activity and crosslinking properties.

[0012] Preferably, the phenolic epoxy resin can be at least one of o-cresol type phenolic epoxy resin or bisphenol A type phenolic epoxy resin.

[0013] As a further improvement of the present invention, the epoxy reactive diluent is a C12-14 alkyl glycidyl ether; the particle size of the expanded graphite is 200-400 mesh; the selection of the particle size of the expanded graphite is beneficial to adjusting the viscosity of the coating to ensure good workability, while also helping to further improve the flame retardant and heat insulation properties of the coating.

[0014] As a further improvement of the present invention, the phenolic epoxy resin is a phenol-formaldehyde epoxy resin, which is beneficial to increase the crosslinking density to further improve the heat resistance of the coating.

[0015] Preferably, the epoxy reactive diluent is a C12-14 alkyl glycidyl ether, which has good wettability, thus improving the dispersibility of inorganic fillers in the coating and enhancing the adhesion of the coating.

[0016] Preferably, the epoxy reactive diluent may include ethylene glycol diglycidyl ether with a diepoxy group.

[0017] As a further improvement of the present invention, the ratio of component A to component B by weight is 7-10:1.

[0018] As a further improvement of the present invention, the mass ratio of aluminum oxide to silicon dioxide in the alumina fiber is 60-95:40-5. This component ratio of the alumina fiber is beneficial for further improving the flame retardant and heat insulation properties of the coating.

[0019] As a further improvement of the present invention, the method for preparing the modified alumina is as follows:

[0020] S1. HCCP-CHO was prepared by reacting p-hydroxybenzaldehyde and hexachlorotriphosphazene.

[0021] S2. An aminosilane coupling agent is reacted with HCCP-CHO to prepare an HCCP-silane coupling agent;

[0022] S3. Reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide with HCCP-silane coupling agent to prepare HCCP-silane coupling agent-DOPS;

[0023] S4. Alumina and epoxy silane coupling agent are reacted to prepare silane coupling agent modified alumina;

[0024] S5. HCCP-silane coupling agent-DOPS and silane coupling agent modified alumina are reacted to obtain modified alumina.

[0025] As a further improvement of the present invention, in step S1, the molar ratio of p-hydroxybenzaldehyde and hexachlorotriphosphazene is 1:6.5-7, the reaction temperature is 65-75℃, and the time is 20-24h; in step S2, the molar ratio of aminosilane coupling agent and HCCP-CHO is 6.2-6.5:1, the reaction temperature is 95-105℃, and the time is 20-24h, wherein the aminosilane coupling agent is selected from at least one of KH550, KH602, and KH792; in step S3, the molar ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide and HCCP-silane coupling agent is 6.2-6.5:1, the reaction temperature is 95-105℃, and the time is 20-24h.

[0026] As a further improvement of the present invention, in step S4, the mass ratio of alumina to epoxy silane coupling agent is 10:3-5, the epoxy silane coupling agent is KH560, the reaction temperature is 40-50℃, and the time is 3-5h; in step S5, the mass ratio of HCCP-silane coupling agent-DOPS to silane coupling agent modified alumina is 2-4:10, the reaction temperature is 45-55℃, and the time is 2-4h.

[0027] This invention prepares a modified alumina. First, p-hydroxybenzaldehyde and hexachlorotriphosphazene are reacted to obtain HCCP-CHO. The reaction equation is as follows:

[0028] ;

[0029] Next, the aminosilane coupling agent reacts with HCCP-CHO. The aldehyde group on HCCP-CHO can react with the amino group to form a C=N bond. Then, the C=N bond can react with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide (DPOS) to achieve coupling.

[0030] After the surface of alumina powder is modified with an epoxy-containing silane coupling agent, the epoxy groups can react with HCCP-silane coupling agent-DOPS and the amino groups of the silane coupling agent to achieve coupling. The resulting modified alumina, when added to coatings, significantly improves the coating's fire resistance, flame retardancy, and high strength. The introduction of sulfur enhances the flame-retardant effect of phosphorus; sulfur compounds decompose at high temperatures, releasing strong acids such as H2SO4, promoting the dehydration and carbonization of the substrate, thus exhibiting good flame-retardant properties even in the condensed phase. The introduction of silicon forms a physically insulating carbon layer with excellent silicon-containing or silicon-carbon bonds, effectively exerting a flame-retardant effect. Furthermore, the synergistic flame-retardant effect of N, P, Si, and S elements improves the fire safety and smoke suppression performance of the coating.

[0031] This invention further protects a method for preparing the above-mentioned epoxy fire-retardant coating, comprising the following steps:

[0032] (1) Mix aluminum hydroxide, melamine, ammonium polyphosphate, expanded graphite, alumina fiber, barium sulfate, modified alumina and titanium dioxide, and ball mill for 1-3 hours to obtain a mixture;

[0033] (2) Add the mixture to the silane-modified phenolic epoxy resin and disperse at 1000-2000 r / min for 10-20 min. Add the epoxy reactive diluent and continue to disperse for 5-10 min. Then add the phenolic amine and 1,3-cyclohexanedimethylamine and stir for 15-20 min to obtain the epoxy fireproof coating.

[0034] The present invention has the following beneficial effects:

[0035] In this invention, the aromatic rings in the side chains of silane-modified phenolic epoxy resin give the coating good radiation resistance, thus helping to reduce radiation-induced degradation. Furthermore, the silane-modified phenolic epoxy resin, when compounded with amines such as melamine, phenolic amines, and 1,3-cyclohexanedimethylamine, allows the coating to cure at room temperature while also improving fire resistance time, fire stability, and providing excellent expansion insulation. Additionally, the dehydration-to-carbonation catalyst ammonium polyphosphate reacts with the flame retardant aluminum hydroxide at temperatures above 160°C to deaminate into phosphoric acid, which then reacts with hydroxyl-containing molecular chains, such as phenolic resin and epoxy resin. During this reaction, polyphosphate is repeatedly generated, acting as a strong dehydrating agent. It removes a large amount of water during the reaction, thereby altering the chemical process of the organic thermal decomposition reaction. This causes the hydroxyl-containing organic compounds to dehydrate and generate an unsaturated main chain, which then forms a good carbonized layer through a cyclization bridging reaction. Furthermore, this invention employs melamine and expanded graphite synergistically as a foaming agent. The synergistic effect of the foaming agent and dehydration-to-carbonization catalyst selected in this invention can form a better foamed carbonized layer, thereby solving the problem of the carbonized layer being lifted or the leakage of flame-retardant gases, and thus further improving the fire resistance. In addition, the compounding of alumina fiber, barium sulfate, titanium dioxide, and resin also helps to further improve the anti-corrosion performance and fire-retardant effect of the coating. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The phenolic epoxy resin is model F-51 with a viscosity of 3500-6000 (25℃ mPa.s). The corresponding manufacturer is model WE-8401, and the manufacturer is Guangzhou Weichuang High-Tech Materials Technology Co., Ltd.

[0038] The CAS number of the methylphenyl intermediate silanol is 5272-18-4, the viscosity is 20-200 (25℃ mPa.s), and the manufacturer is Beijing Bailingwei Technology Co., Ltd.

[0039] Preparation Example 1: Preparation of Silane-Modified Phenolic Epoxy Resin

[0040] include:

[0041] By weight, add 2 parts of methylphenyl intermediate silanol, 90 parts of phenolic epoxy resin and 3 parts of γ-glycidyl etheroxypropyltrimethoxysilane to the reaction vessel; stir and heat to 120°C, and stir the reaction until the epoxy value of the system is 0.4 (100g / g) and the viscosity is 3500 (25°C mPa.s), then stop stirring and discharge the material.

[0042] Preparation Example 2: Preparation of Silane-Modified Phenolic Epoxy Resin

[0043] include:

[0044] By weight, add 5 parts of methylphenyl intermediate silanol, 95 parts of phenolic epoxy resin and 5 parts of γ-glycidyl etheroxypropyltrimethoxysilane to the reaction vessel; stir and heat to 130℃, stir and react until the epoxy value of the system is 0.54 (100g / g) and the viscosity is 6500 (25℃ mPa.s), then stop stirring and discharge the material.

[0045] Preparation Example 3: Preparation of Silane-Modified Phenolic Epoxy Resin

[0046] include:

[0047] By weight, add 3.5 parts of methylphenyl intermediate silanol, 92 parts of phenolic epoxy resin and 4 parts of γ-glycidyl etheroxypropyltrimethoxysilane to the reaction vessel; stir and heat to 125°C, and stir the reaction until the epoxy value of the system is 0.47 (100g / g) and the viscosity is 5000 (25°C mPa.s), then stop stirring and discharge the material.

[0048] Preparation Example 4: Preparation of Modified Alumina

[0049] The method is as follows:

[0050] S1. Dissolve 0.65 mol p-hydroxybenzaldehyde, 0.7 mol anhydrous sodium carbonate, and 500 mL tetrahydrofuran by stirring. Add 100 mL of a 0.1 mol hexachlorotriphosphazene tetrahydrofuran solution dropwise. After the addition is complete, heat to 65 °C and stir for 20 h. After the reaction is complete, cool to room temperature, filter, wash, and dry to obtain HCCP-CHO with a yield of 90%.

[0051] S2. Mix 0.62 mol of silane coupling agent KH550, 0.1 mol of HCCP-CHO and 500 mL of 1,4-dioxane evenly, heat to 95℃, stir and react for 20 h. After the reaction is completed, cool to room temperature, filter, wash and dry to obtain HCCP-silane coupling agent with a yield of 82%.

[0052] S3. Mix 0.62 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide, 0.1 mol of HCCP-silane coupling agent and 500 mL of 1,4-dioxane evenly, heat to 95 °C under nitrogen protection, stir and react for 20 h. After the reaction is completed, cool to room temperature, filter, wash and dry to obtain HCCP-silane coupling agent-DOPS;

[0053] S4. Add 10g of alumina and 3g of silane coupling agent KH560 to 200mL of ethanol, heat to 40℃, stir and react for 3h, filter, wash and dry to obtain silane coupling agent modified alumina.

[0054] S5. Add 2g of HCCP-silane coupling agent-DOPS and 10g of silane coupling agent modified alumina to 200mL of ethanol, heat to 45℃, stir and react for 2h, filter, wash, and dry to obtain modified alumina.

[0055] Preparation Example 5: Preparation of Modified Alumina

[0056] The method is as follows:

[0057] S1. 0.7 mol p-hydroxybenzaldehyde, 0.7 mol anhydrous sodium carbonate, and 500 mL tetrahydrofuran were stirred and mixed to dissolve. 100 mL of a 0.1 mol hexachlorotriphosphazene tetrahydrofuran solution was added dropwise. After the addition was complete, the mixture was heated to 75 °C and stirred for 24 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain HCCP-CHO with a yield of 92%.

[0058] S2. Mix 0.65 mol of silane coupling agent KH792, 0.1 mol of HCCP-CHO and 500 mL of 1,4-dioxane evenly, heat to 105 °C, stir and react for 24 h. After the reaction is completed, cool to room temperature, filter, wash and dry to obtain HCCP-silane coupling agent with a yield of 85%.

[0059] S3. Mix 0.65 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide, 0.1 mol of HCCP-silane coupling agent and 500 mL of 1,4-dioxane evenly, heat to 105 °C under nitrogen protection, stir and react for 24 h. After the reaction is completed, cool to room temperature, filter, wash and dry to obtain HCCP-silane coupling agent-DOPS;

[0060] S4. Add 10g of alumina and 5g of silane coupling agent KH560 to 200mL of ethanol, heat to 50℃, stir and react for 5h, filter, wash and dry to obtain silane coupling agent modified alumina.

[0061] S5. Add 4g of HCCP-silane coupling agent-DOPS and 10g of silane coupling agent modified alumina to 200mL of ethanol, heat to 55℃, stir and react for 4h, filter, wash, and dry to obtain modified alumina.

[0062] Preparation Example 6: Preparation of Modified Alumina

[0063] The method is as follows:

[0064] S1. 0.67 mol p-hydroxybenzaldehyde, 0.7 mol anhydrous sodium carbonate, and 500 mL tetrahydrofuran were stirred and mixed to dissolve. 100 mL of a 0.1 mol hexachlorotriphosphazene tetrahydrofuran solution was added dropwise. After the addition was complete, the mixture was heated to 70 °C and stirred for 22 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain HCCP-CHO with a yield of 90%.

[0065] S2. Mix 0.63 mol of silane coupling agent KH602, 0.1 mol of HCCP-CHO and 500 mL of 1,4-dioxane evenly, heat to 100℃, stir and react for 22 h. After the reaction is completed, cool to room temperature, filter, wash and dry to obtain HCCP-silane coupling agent with a yield of 82%.

[0066] S3. Mix 0.63 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide, 0.1 mol of HCCP-silane coupling agent and 500 mL of 1,4-dioxane evenly, heat to 100 °C under nitrogen protection, stir and react for 22 h. After the reaction is completed, cool to room temperature, filter, wash and dry to obtain HCCP-silane coupling agent-DOPS;

[0067] S4. Add 10g of alumina and 4g of silane coupling agent KH560 to 200mL of ethanol, heat to 45℃, stir and react for 4h, filter, wash and dry to obtain silane coupling agent modified alumina.

[0068] S5. Add 3g of HCCP-silane coupling agent-DOPS and 10g of silane coupling agent modified alumina to 200mL of ethanol, heat to 50℃, stir and react for 3h, filter, wash, and dry to obtain modified alumina.

[0069] Comparative Preparation Example 1

[0070] The difference from preparation example 6 is that step S3 was not performed.

[0071] Specifically as follows:

[0072] S1. 0.67 mol p-hydroxybenzaldehyde, 0.7 mol anhydrous sodium carbonate, and 500 mL tetrahydrofuran were stirred and mixed to dissolve. 100 mL of a 0.1 mol hexachlorotriphosphazene tetrahydrofuran solution was added dropwise. After the addition was complete, the mixture was heated to 70 °C and stirred for 22 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain HCCP-CHO with a yield of 90%.

[0073] S2. Mix 0.63 mol of silane coupling agent KH602, 0.1 mol of HCCP-CHO and 500 mL of 1,4-dioxane evenly, heat to 100℃, stir and react for 22 h. After the reaction is completed, cool to room temperature, filter, wash and dry to obtain HCCP-silane coupling agent with a yield of 82%.

[0074] S3. Add 10g of alumina and 4g of silane coupling agent KH560 to 200mL of ethanol, heat to 45℃, stir and react for 4h, filter, wash and dry to obtain silane coupling agent modified alumina.

[0075] S4. Add 3g of HCCP-silane coupling agent and 10g of silane coupling agent-modified alumina to 200mL of ethanol, heat to 50℃, stir and react for 3h, filter, wash, and dry to obtain modified alumina.

[0076] Comparative Preparation Example 2

[0077] Compared with Preparation Example 6, the difference is that steps S2 and S3 were not performed, and in step S4, the silane coupling agent KH560 was replaced with KH550.

[0078] Specifically as follows:

[0079] S1. 0.67 mol p-hydroxybenzaldehyde, 0.7 mol anhydrous sodium carbonate, and 500 mL tetrahydrofuran were stirred and mixed to dissolve. 100 mL of a 0.1 mol hexachlorotriphosphazene tetrahydrofuran solution was added dropwise. After the addition was complete, the mixture was heated to 70 °C and stirred for 22 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain HCCP-CHO with a yield of 90%.

[0080] S2. Add 10g of alumina and 4g of silane coupling agent KH550 to 200mL of ethanol, heat to 45℃, stir and react for 4h, filter, wash and dry to obtain silane coupling agent modified alumina.

[0081] S3. Add 3g HCCP-CHO and 10g silane coupling agent modified alumina to 200mL ethanol, heat to 50℃, stir and react for 3h, filter, wash, and dry to obtain modified alumina.

[0082] Example 1

[0083] An epoxy fire-retardant coating comprises component A and component B, characterized in that, by weight, component A comprises 20 parts of silane-modified phenolic epoxy resin prepared in Preparation Example 1, 5 parts of diepoxy ethylene glycol diglycidyl ether, 5 parts of aluminum hydroxide, 5 parts of melamine, 25 parts of ammonium polyphosphate, 0.5 parts of expanded graphite, 6 parts of alumina fiber, 3 parts of barium sulfate, 3 parts of modified alumina prepared in Preparation Example 4, and 2 parts of titanium dioxide. In the alumina fiber, the mass ratio of aluminum oxide to silicon dioxide is 60:40.

[0084] The expanded graphite has a particle size of 300 mesh; the phenolic epoxy resin is a phenol-formaldehyde epoxy resin.

[0085] By weight, component B comprises 40 parts of phenolic amine and 50 parts of 1,3-cyclohexanedimethylamine.

[0086] The ratio of component A to component B is 10:1 by weight.

[0087] The preparation method includes the following steps:

[0088] (1) A mixture of aluminum hydroxide, melamine, ammonium polyphosphate, expanded graphite, alumina fiber, barium sulfate, modified alumina and titanium dioxide was ball-milled for 1 hour to obtain a mixture;

[0089] (2) Add the mixture to the silane-modified phenolic epoxy resin, disperse at 1000 r / min for 10 min, add epoxy reactive diluent, continue to disperse for 5 min, then add phenolic amine and 1,3-cyclohexanedimethylamine, stir and mix for 15 min to obtain epoxy fireproof coating.

[0090] Example 2

[0091] An epoxy fire-retardant coating comprises component A and component B, characterized in that, by weight, component A comprises 30 parts of silane-modified phenolic epoxy resin prepared in Preparation Example 2, 9 parts of diepoxy ethylene glycol diglycidyl ether, 10 parts of aluminum hydroxide, 8 parts of melamine, 48 parts of ammonium polyphosphate, 1 part of expanded graphite, 8 parts of alumina fiber, 10 parts of barium sulfate, 5 parts of modified alumina prepared in Preparation Example 5, and 5 parts of titanium dioxide. In the alumina fiber, the mass ratio of aluminum oxide to silicon dioxide is 95:5.

[0092] The expanded graphite has a particle size of 400 mesh; the phenolic epoxy resin is a phenol-formaldehyde epoxy resin.

[0093] By weight, component B comprises 50 parts of phenolic amine and 60 parts of 1,3-cyclohexanedimethylamine.

[0094] The ratio of component A to component B is 10:1 by weight.

[0095] The preparation method includes the following steps:

[0096] (1) A mixture of aluminum hydroxide, melamine, ammonium polyphosphate, expanded graphite, alumina fiber, barium sulfate, modified alumina and titanium dioxide was ball-milled for 3 hours to obtain a mixture;

[0097] (2) Add the mixture to the silane-modified phenolic epoxy resin, disperse at 2000 r / min for 20 min, add the ethylene glycol diglycidyl ether with a diepoxy group, continue to disperse for 10 min, then add phenolic amine and 1,3-cyclohexanedimethylamine, stir and mix for 20 min to obtain the epoxy fireproof coating.

[0098] Example 3

[0099] An epoxy fire-retardant coating comprises component A and component B, characterized in that, by weight, component A comprises 25 parts of silane-modified phenolic epoxy resin prepared in Preparation Example 3, 7 parts of diepoxy ethylene glycol diglycidyl ether, 7 parts of aluminum hydroxide, 7 parts of melamine, 39 parts of ammonium polyphosphate, 0.7 parts of expanded graphite, 7 parts of alumina fiber, 7 parts of barium sulfate, 4 parts of modified alumina prepared in Preparation Example 6, and 3 parts of titanium dioxide. In the alumina fiber, the mass ratio of aluminum oxide to silicon dioxide is 75:25.

[0100] The expanded graphite has a particle size of 200 mesh; the phenolic epoxy resin is a phenol-formaldehyde epoxy resin.

[0101] By weight, component B comprises 45 parts of phenolic amine and 55 parts of 1,3-cyclohexanedimethylamine.

[0102] The ratio of component A to component B is 9:1 by weight.

[0103] The preparation method includes the following steps:

[0104] (1) A mixture of aluminum hydroxide, melamine, ammonium polyphosphate, expanded graphite, alumina fiber, barium sulfate, modified alumina and titanium dioxide was ball-milled for 2 hours to obtain a mixture;

[0105] (2) Add the mixture to the silane-modified phenolic epoxy resin, disperse at 1500 r / min for 15 min, add the ethylene glycol diglycidyl ether with a diepoxy group, continue to disperse for 7 min, then add phenolic amine and 1,3-cyclohexanedimethylamine, stir and mix for 17 min to obtain the epoxy fireproof coating.

[0106] Comparative Example 1

[0107] The difference from Example 3 is that the modified alumina was prepared by Comparative Preparation Example 1.

[0108] Comparative Example 2

[0109] The difference from Example 3 is that the modified alumina was prepared by Comparative Preparation Example 2.

[0110] Comparative Example 3

[0111] The difference compared to Example 3 is that no modified alumina was added.

[0112] Specifically as follows:

[0113] An epoxy fire-retardant coating comprises component A and component B, characterized in that, by weight, component A comprises 25 parts of silane-modified phenolic epoxy resin prepared in Preparation Example 3, 7 parts of diepoxy ethylene glycol diglycidyl ether, 7 parts of aluminum hydroxide, 7 parts of melamine, 39 parts of ammonium polyphosphate, 0.7 parts of expanded graphite, 7 parts of alumina fiber, 7 parts of barium sulfate, 4 parts of modified alumina prepared in Preparation Example 6, and 3 parts of titanium dioxide. In the alumina fiber, the mass ratio of aluminum oxide to silicon dioxide is 75:25.

[0114] The expanded graphite has a particle size of 200 mesh; the phenolic epoxy resin is a phenol-formaldehyde epoxy resin.

[0115] By weight, component B comprises 45 parts of phenolic amine and 55 parts of 1,3-cyclohexanedimethylamine.

[0116] The ratio of component A to component B is 9:1 by weight.

[0117] The preparation method includes the following steps:

[0118] (1) A mixture of aluminum hydroxide, melamine, ammonium polyphosphate, expanded graphite, alumina fiber, barium sulfate, modified alumina and titanium dioxide was ball-milled for 2 hours to obtain a mixture;

[0119] (2) Add the mixture to the silane-modified phenolic epoxy resin, disperse at 1500 r / min for 15 min, add the ethylene glycol diglycidyl ether with a diepoxy group, continue to disperse for 7 min, then add phenolic amine and 1,3-cyclohexanedimethylamine, stir and mix for 17 min to obtain the epoxy fireproof coating.

[0120] Comparative Example 4

[0121] The difference from Example 3 is that the silane-modified phenolic epoxy resin was replaced by an equal mass of phenolic epoxy resin.

[0122] Comparative Example 5

[0123] The difference compared to Example 3 is that melamine was not added.

[0124] Specifically as follows:

[0125] An epoxy fire-retardant coating comprises component A and component B, characterized in that, by weight, component A comprises 25 parts of silane-modified phenolic epoxy resin obtained in Preparation Example 3, 7 parts of diepoxy ethylene glycol diglycidyl ether, 7 parts of aluminum hydroxide, 39 parts of ammonium polyphosphate, 7.7 parts of expanded graphite, 7 parts of alumina fiber, 7 parts of barium sulfate, 4 parts of modified alumina obtained in Preparation Example 6, and 3 parts of titanium dioxide. In the alumina fiber, the mass ratio of aluminum oxide to silicon dioxide is 75:25.

[0126] The expanded graphite has a particle size of 200 mesh; the phenolic epoxy resin is a phenol-formaldehyde epoxy resin.

[0127] By weight, component B comprises 45 parts of phenolic amine and 55 parts of 1,3-cyclohexanedimethylamine.

[0128] The ratio of component A to component B is 9:1 by weight.

[0129] The preparation method includes the following steps:

[0130] (1) A mixture of aluminum hydroxide, ammonium polyphosphate, expanded graphite, alumina fiber, barium sulfate, modified alumina and titanium dioxide was ball-milled for 2 hours to obtain a mixture;

[0131] (2) Add the mixture to the silane-modified phenolic epoxy resin, disperse at 1500 r / min for 15 min, add the ethylene glycol diglycidyl ether with a diepoxy group, continue to disperse for 7 min, then add phenolic amine and 1,3-cyclohexanedimethylamine, stir and mix for 17 min to obtain the epoxy fireproof coating.

[0132] Comparative Example 6

[0133] The difference compared to Example 3 is that no expanded graphite was added.

[0134] Specifically as follows:

[0135] An epoxy fire-retardant coating comprises component A and component B, characterized in that, by weight, component A comprises 25 parts of silane-modified phenolic epoxy resin prepared in Preparation Example 3, 7 parts of diepoxy ethylene glycol diglycidyl ether, 7 parts of aluminum hydroxide, 7.7 parts of melamine, 39 parts of ammonium polyphosphate, 7 parts of alumina fiber, 7 parts of barium sulfate, 4 parts of modified alumina prepared in Preparation Example 6, and 3 parts of titanium dioxide. In the alumina fiber, the mass ratio of aluminum oxide to silicon dioxide is 75:25.

[0136] The expanded graphite has a particle size of 200 mesh; the phenolic epoxy resin is a phenol-formaldehyde epoxy resin.

[0137] By weight, component B comprises 45 parts of phenolic amine and 55 parts of 1,3-cyclohexanedimethylamine.

[0138] The ratio of component A to component B is 9:1 by weight.

[0139] The preparation method includes the following steps:

[0140] (1) Mix aluminum hydroxide, melamine, ammonium polyphosphate, alumina fiber, barium sulfate, modified alumina and titanium dioxide, and ball mill for 2 hours to obtain a mixture;

[0141] (2) Add the mixture to the silane-modified phenolic epoxy resin, disperse at 1500 r / min for 15 min, add the ethylene glycol diglycidyl ether with a diepoxy group, continue to disperse for 7 min, then add phenolic amine and 1,3-cyclohexanedimethylamine, stir and mix for 17 min to obtain the epoxy fireproof coating.

[0142] Comparative Example 7

[0143] The difference compared to Example 3 is that melamine and expanded graphite were not added.

[0144] Specifically as follows:

[0145] An epoxy fire-retardant coating comprises component A and component B, characterized in that, by weight, component A comprises 25 parts of silane-modified phenolic epoxy resin prepared in Preparation Example 3, 7 parts of diepoxy ethylene glycol diglycidyl ether, 7 parts of aluminum hydroxide, 39 parts of ammonium polyphosphate, 7 parts of alumina fiber, 7 parts of barium sulfate, 4 parts of modified alumina prepared in Preparation Example 6, and 3 parts of titanium dioxide. In the alumina fiber, the mass ratio of aluminum oxide to silicon dioxide is 75:25.

[0146] The expanded graphite has a particle size of 200 mesh; the phenolic epoxy resin is a phenol-formaldehyde epoxy resin.

[0147] By weight, component B comprises 45 parts of phenolic amine and 55 parts of 1,3-cyclohexanedimethylamine.

[0148] The ratio of component A to component B is 9:1 by weight.

[0149] The preparation method includes the following steps:

[0150] (1) Aluminum hydroxide, ammonium polyphosphate, alumina fiber, barium sulfate, modified alumina and titanium dioxide were mixed and ball-milled for 2 hours to obtain a mixture;

[0151] (2) Add the mixture to the silane-modified phenolic epoxy resin, disperse at 1500 r / min for 15 min, add the ethylene glycol diglycidyl ether with a diepoxy group, continue to disperse for 7 min, then add phenolic amine and 1,3-cyclohexanedimethylamine, stir and mix for 17 min to obtain the epoxy fireproof coating.

[0152] Test Example 1

[0153] The epoxy fire-retardant coatings prepared in Examples 1-3 and Comparative Examples 1-7 were subjected to performance tests, and the results are shown in Table 1.

[0154] (1) State in the container: If the coating is uniform and fine or thick and fluid after stirring and there are no lumps, it is qualified.

[0155] (2) The surface drying time, initial drying crack resistance, bond strength and fire resistance limit can all be determined according to the corresponding part of the national standard GB14907-2018.

[0156] (3) Salt spray resistance: Tested according to the requirements of GB / T1766-2008, the test is conducted for the longest time without cracking, peeling, rusting and blistering.

[0157] (4) Artificial aging: Tested according to the requirements of GB / T1766-2008, the longest time without cracking, peeling, rusting and blistering.

[0158] (5) Water resistance test: Use procedure B of NB / T20133.5-2012 to test the longest time without cracking, peeling, rusting and blistering. Slight uniform changes in color and gloss are allowed and it is judged to be compliant.

[0159] Table 1

[0160] Group Initial drying crack resistance State within the container Drying time (h) Bond strength / MPa Fire resistance rating (h) Salt spray tolerance time (h) Artificial aging resistance time (h) Water resistance time (d) Example 1 No cracks qualified 4 2.7 4.5 9270 1500 265 Example 2 No cracks qualified 4 2.6 4.4 9300 1550 262 Example 3 No cracks qualified 4 2.8 4.7 9380 1520 267 Comparative Example 1 No cracks qualified 4 2.4 3.7 9230 1340 252 Comparative Example 2 No cracks qualified 4 2.3 3.5 9210 1310 250 Comparative Example 3 No cracks qualified 4 2.2 3.0 9200 1250 240 Comparative Example 4 Cracks qualified 5 2.0 4.1 8850 970 248 Comparative Example 5 No cracks qualified 4.2 2.3 3.5 9050 1550 240 Comparative Example 6 No cracks qualified 4.3 2.2 3.4 9070 1580 251 Comparative Example 7 No cracks qualified 4.6 2.2 2.8 9010 1480 239

[0161] As can be seen from the table above, the epoxy fire-retardant coatings prepared in Examples 1-3 of the present invention have good comprehensive performance.

[0162] Test Example 2

[0163] The epoxy fire-retardant coatings prepared in Examples 1-3 and Comparative Examples 1-7 were subjected to performance tests, and the results are shown in Table 2.

[0164] Limiting Oxygen Index (LOI): The LIOI was determined using a JF-5 limiting oxygen index tester in accordance with the national standard GB / T 2406.1-2008. The sample size was 80(±5)mm×6.5(±0.5)mm×3.0(±0.25)mm.

[0165] Vertical burning (UL-94): The test was conducted using a CZF-5 vertical burning tester in accordance with the national standard GB / T 2408-2021. The sample size was 125(±5)mm×13.0(±0.3)mm×3.0(±0.2)mm.

[0166] Table 2

[0167] Group LOI (%) UL-94 Example 1 36.7 V-0 Example 2 36.4 V-0 Example 3 36.9 V-0 Comparative Example 1 33.1 V-0 Comparative Example 2 32.7 V-0 Comparative Example 3 26.1 V-2 Comparative Example 4 34.8 V-0 Comparative Example 5 31.0 V-0 Comparative Example 6 30.4 V-1 Comparative Example 7 28.1 V-1

[0168] As can be seen from the table above, the epoxy fire-retardant coatings prepared in Examples 1-3 of the present invention have good flame-retardant properties.

[0169] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An epoxy fire-retardant coating, comprising component A and component B, characterized in that, By weight, component A comprises 20-30 parts of silane-modified phenolic epoxy resin, 5-9 parts of epoxy reactive diluent, 5-10 parts of aluminum hydroxide, 5-8 parts of melamine, 25-48 parts of ammonium polyphosphate, 0.5-1 parts of expanded graphite, 6-8 parts of alumina fiber, 3-10 parts of barium sulfate, 3-5 parts of modified alumina, and 2-5 parts of titanium dioxide. By weight, component B comprises 40-50 parts of phenolic amine and 50-60 parts of 1,3-cyclohexanedimethylamine; The modified alumina is prepared as follows: S1. HCCP-CHO was prepared by reacting p-hydroxybenzaldehyde and hexachlorotriphosphazene. S2. An aminosilane coupling agent is reacted with HCCP-CHO to prepare an HCCP-silane coupling agent; S3. Reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide with HCCP-silane coupling agent to prepare HCCP-silane coupling agent-DOPS; S4. Alumina and epoxy silane coupling agent are reacted to prepare silane coupling agent modified alumina; S5. HCCP-silane coupling agent-DOPS and silane coupling agent modified alumina are reacted to obtain modified alumina.

2. The epoxy fire-retardant coating according to claim 1, characterized in that, The preparation of the silane-modified phenolic epoxy resin includes: By weight, add 2-5 parts of methylphenyl intermediate silanol, 90-95 parts of phenolic epoxy resin and 3-5 parts of silane coupling agent to the reaction vessel. Stir and heat to 120-130℃, stirring until the epoxy value of the system is 0.4-0.54, and the viscosity is 3500-6500 mPa.s at 25℃. Stop stirring and discharge the material.

3. The epoxy fire-retardant coating according to claim 2, characterized in that, The viscosity of the methylphenyl intermediate silanol at 25°C is 20-200 mPa·s, and the viscosity of the phenolic epoxy resin at 25°C is 3500-6000 mPa·s; the silane coupling agent is γ-glycidoxypropyltrimethoxysilane.

4. The epoxy fire-retardant coating according to claim 1, characterized in that, The epoxy reactive diluent is a C12-14 alkyl glycidyl ether; the expanded graphite has a particle size of 200-400 mesh; and the phenolic epoxy resin is a phenol-formaldehyde epoxy resin.

5. The epoxy fire-retardant coating according to claim 1, characterized in that, By weight, the ratio of component A to component B is 7-10:

1.

6. The epoxy fire-retardant coating according to claim 1, characterized in that, In the alumina fiber, the mass ratio of aluminum oxide to silicon dioxide is 60-95:40-5.

7. The epoxy fire-retardant coating according to claim 1, characterized in that, In step S1, the molar ratio of p-hydroxybenzaldehyde to hexachlorotriphosphazene is 1:6.5-7, the reaction temperature is 65-75℃, and the reaction time is 20-24h; in step S2, the molar ratio of aminosilane coupling agent to HCCP-CHO is 6.2-6.5:1, the reaction temperature is 95-105℃, and the reaction time is 20-24h, wherein the aminosilane coupling agent is selected from at least one of KH550, KH602, and KH792; in step S3, the molar ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide to HCCP-silane coupling agent is 6.2-6.5:1, the reaction temperature is 95-105℃, and the reaction time is 20-24h.

8. The epoxy fire-retardant coating according to claim 1, characterized in that, In step S4, the mass ratio of alumina to epoxy silane coupling agent is 10:3-5, the epoxy silane coupling agent is KH560, the reaction temperature is 40-50℃, and the time is 3-5h; in step S5, the mass ratio of HCCP-silane coupling agent-DOPS to silane coupling agent modified alumina is 2-4:10, the reaction temperature is 45-55℃, and the time is 2-4h.

9. A method for preparing an epoxy fire-retardant coating as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Mix aluminum hydroxide, melamine, ammonium polyphosphate, expanded graphite, alumina fiber, barium sulfate, modified alumina and titanium dioxide, and ball mill for 1-3 hours to obtain a mixture; (2) Add the mixture to the silane-modified phenolic epoxy resin and disperse at 1000-2000 r / min for 10-20 min. Add the epoxy reactive diluent and continue to disperse for 5-10 min. Then add the phenolic amine and 1,3-cyclohexanedimethylamine and stir for 15-20 min to obtain the epoxy fireproof coating.