Elastic fireproof coating as well as preparation method and application thereof

Abstract

The invention provides an elastic fireproof coating as well as a preparation method and application thereof, and belongs to the technical field of functional material preparation. An elastic fireproof coating formed by the elastic fireproof coating provided by the invention has good adhesive force, good flexibility, water resistance, fire resistance and tear strength, can provide fire protection, and can adapt to dynamic working conditions of structural members. Results of the embodiment show that a coating formed by the elastic fireproof coating provided by the invention has no problems of cracking, peeling and the like after being bent for multiple times, meanwhile, the elongation at break is greater than or equal to 200%, the coating does not change after 24-hour soaking, the coating meets the 2h fireproof standard GB14907-2018, and the elastic fireproof coating can be widely applied to the field of fireproof materials. A coating layer formed by the elastic fireproof coating provided by the invention has excellent flexibility and water-resistant and fireproof performance.

Description

Technical Field

[0001] This invention relates to the field of functional material preparation technology, and in particular to an elastic fire-retardant coating, its preparation method, and its application. Background Technology

[0002] Conventional intumescent fire-retardant coatings for steel structures, non-ferrous metals, and wood are generally rigid coatings. These coatings, applied to substrates like steel, form a rigid fire-retardant layer, providing excellent fire resistance. While rigid fire-retardant coatings possess high strength, they have poor flexibility and weak adhesion to the substrate. Over prolonged use, the substrate experiences significant vibration and deflection, leading to cracking and peeling of the rigid coating. Even in areas without obvious cracks, numerous micro-cracks appear, allowing corrosive media like moisture to penetrate the coating and ultimately destroy it, severely impacting its lifespan. To avoid these problems, regular repairs and recoating of rigid fire-retardant coatings are necessary, significantly increasing costs and severely limiting their application.

[0003] Therefore, how to provide a coating with good adhesion, high flexibility, and excellent water resistance and fire resistance has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide an elastic fire-retardant coating, its preparation method, and its application. The elastic fire-retardant coating provided by this invention not only has good adhesion to the substrate, but also high flexibility and excellent water resistance and fire resistance.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an elastic fire-retardant coating. The raw materials for preparing the elastic fire-retardant coating, by weight, include the following components: 40-50 parts of coating matrix, 10-25 parts of ammonium polyphosphate, 10-30 parts of charring agent, 5-20 parts of gas generator, 2-10 parts of water, 2-10 parts of crosslinking agent, and 3-10 parts of additives. The raw materials for preparing the coating matrix include a mixed emulsion, an initiator, and an acrylic solution; the mass ratio of the mixed emulsion, initiator, and acrylic solution is 100:(0.5~3):(1~3). The raw materials for preparing the mixed emulsion, by mass parts, include the following components: 1-2 parts of γ-aminopropyltriethoxysilane, 10-20 parts of hydroxyl-terminated vinyl silicone oil, 10-25 parts of dimethylolpropionic acid, 40-60 parts of isophorone diisocyanate, 120-200 parts of polyether polyol, 1-5 parts of organometallic compound solution, 20-30 parts of methyl ethyl ketone, 1-5 parts of triethylamine, and 200-400 parts of water.

[0006] Preferably, the char-forming agent is pentaerythritol or pentaerythritol phosphate.

[0007] Preferably, the gas generator is melamine, a melamine derivative, or p-toluenesulfonate aminourea.

[0008] Preferably, the additives include pigments, dispersants, and thickeners.

[0009] Preferably, the mass ratio of the pigment, dispersant and thickener is (1~10):(0.5~2):(0.05~0.3).

[0010] Preferably, the crosslinking agent is a aziridine crosslinking agent.

[0011] Preferably, the initiator is potassium persulfate; the acrylic acid solution is an aqueous solution of acrylic acid; and the mass concentration of the acrylic acid solution is 5-20%.

[0012] Preferably, the organometallic compound in the organometallic compound solution is an organotin or organobismuth; the mass concentration of the organometallic compound solution is 0.1-5%.

[0013] This invention provides a method for preparing the elastic fire-retardant coating described above, comprising the following steps: (1) Mix methyl ethyl ketone and isophorone diisocyanate to obtain a premix; (2) Mix polyether polyol, dimethylolpropionic acid and hydroxyl-terminated vinyl silicone oil, then add premixed liquid, then add organometallic compound solution under protective atmosphere to carry out polymerization reaction, and finally add γ-aminopropyltriethoxysilane to obtain a mixture; (3) Mix triethylamine and water to obtain a triethylamine solution, then add the mixture obtained in step (2) to the triethylamine solution for emulsification, and finally perform rotary evaporation to obtain a mixed emulsion; (4) The mixed emulsion, initiator and acrylic solution obtained in step (3) are mixed and then subjected to polymerization reaction to obtain the coating matrix; (5) Mix the coating matrix, ammonium polyphosphate, charring agent, gas generator, additive and water obtained in step (4), and then add crosslinking agent to obtain elastic fireproof coating.

[0014] This invention provides the application of the elastic fire-retardant coating described in the above technical solution or the elastic fire-retardant coating prepared by the preparation method described in the above technical solution in the field of functional materials.

[0015] This invention provides an elastic fire-retardant coating. The raw materials for preparing the elastic fire-retardant coating, by weight, include the following components: 40-50 parts of coating matrix, 10-25 parts of ammonium polyphosphate, 10-30 parts of charring agent, 5-20 parts of gas generator, 2-10 parts of water, 2-10 parts of crosslinking agent, and 3-10 parts of additives. The raw materials for preparing the coating matrix include a mixed emulsion, an initiator, and an acrylic solution; the mass ratio of the mixed emulsion, initiator, and acrylic solution is 1:1. 00: (0.5~3): (1~3); The raw materials for preparing the mixed emulsion by mass parts include the following components: 1~2 parts of γ-aminopropyltriethoxysilane, 10~20 parts of hydroxyl-terminated vinyl silicone oil, 10~25 parts of dimethylolpropionic acid, 40~60 parts of isophorone diisocyanate, 120~200 parts of polyether polyol, 1~5 parts of organometallic compound solution, 20~30 parts of methyl ethyl ketone, 1~5 parts of triethylamine and 200~400 parts of water.This invention incorporates γ-aminopropyltriethoxysilane. Firstly, the single-terminal amino group acts as a chain terminator. Secondly, the introduced silicon generates SiO2 during combustion, significantly strengthening the char layer and preventing the coating from melting and dripping under heat. It also acts as an organosilicon modifier, introducing siloxane segments into the polyurethane backbone through the reaction of amino groups with -NCO, greatly improving the coating's hydrophobicity, smoothness, weather resistance, and heat resistance. Hydroxyl-terminated vinyl silicone oil introduces siloxane segments through the reaction of hydroxyl groups with -NCO, while the terminal vinyl groups provide crosslinking sites. Dimethylolpropionic acid (DMPA) is a key waterborne raw material; the carboxyl group (-COOH) in DMPA is neutralized by triethylamine, giving the polymer chain hydrophilicity, thus enabling emulsification in water. The addition of isophorone diisocyanate provides a rigid structure and crosslinking points; its -NCO group is the starting point for the entire polyurethane reaction, determining the coating's hardness and strength. Polyether polyol provides flexibility and low-temperature resistance, reacting with IPDI to form the flexible long-chain backbone of the polyurethane. Organometallic compounds... The solution can be used as a catalyst to efficiently catalyze the condensation reaction between isocyanate (-NCO) and hydroxyl group (-OH), significantly shortening the reaction time and lowering the reaction temperature. Using triethylamine as a neutralizing agent can neutralize the carboxyl groups (-COOH) introduced by DMPA, converting them into carboxylates (-COO-), thereby improving water dispersibility. Ammonium polyphosphate decomposes at high temperatures to release polyphosphoric acid, catalyzing the dehydration of charring agents (such as pentaerythritol) into char, while simultaneously releasing gas to expand the char layer, thus forming a fire-retardant layer and significantly improving the flame-retardant performance of the coating. The charring agent forms a robust and porous expanded char layer at high temperatures, further enhancing the flame-retardant performance of the coating. Adding admixtures can adjust the curing speed and viscosity of the elastic fire-retardant coating, further improving its practicality. Adding a gas generator decomposes into gas at high temperatures, providing the gas source needed for liquefying the coating. Adding a aziridine crosslinking agent can form a dense three-dimensional crosslinked network in the coating film, significantly improving the final performance of the coating. The elastic fire-retardant coating provided by this invention forms an elastic fire-retardant coating with good adhesion, flexibility, water resistance, fire resistance, and tear strength. It provides fire protection and can adapt to the dynamic working conditions of structural components. The results of the embodiments show that the coating formed by the elastic fire-retardant coating provided by this invention, after multiple bending, exhibits no cracking or peeling, while maintaining an elongation at break ≥200%, showing no change after 24-hour immersion, and meeting the 2-hour fire resistance standard. This demonstrates that the coating formed by the elastic fire-retardant coating provided by this invention possesses excellent flexibility and water resistance. Attached Figure Description

[0016] Figure 1 A side view of the fire-retardant coating being peeled off from the surface of the fire-retardant felt roll. Figure 2A frontal view of the fire-retardant coating being peeled off from the surface of the fire-retardant felt roll. Figure 3 This is a picture of the fire-retardant coating roll after it has been bent. Figure 4 This is a picture of the fire-retardant coating roll after it has been bent and springed back to its original shape. Figure 5 This is a picture of the fire-retardant coating roll after it has been bent twice. Figure 6 This is a side view of the fire-retardant coating roll after it has been bent twice and the coating has been peeled off. Detailed Implementation

[0017] This invention provides an elastic fire-retardant coating. The raw materials for preparing the elastic fire-retardant coating, by weight, include the following components: 40-50 parts of coating matrix, 10-25 parts of ammonium polyphosphate, 10-30 parts of charring agent, 5-20 parts of gas generator, 2-10 parts of water, 2-10 parts of crosslinking agent, and 3-10 parts of additives. The raw materials for preparing the coating matrix include a mixed emulsion, an initiator, and an acrylic solution; the mass ratio of the mixed emulsion, initiator, and acrylic solution is 100:(0.5~3):(1~3). The raw materials for preparing the mixed emulsion, by mass parts, include the following components: 1-2 parts of γ-aminopropyltriethoxysilane, 10-20 parts of hydroxyl-terminated vinyl silicone oil, 10-25 parts of dimethylolpropionic acid, 40-60 parts of isophorone diisocyanate, 120-200 parts of polyether polyol, 1-5 parts of organometallic compound solution, 20-30 parts of methyl ethyl ketone, 1-5 parts of triethylamine, and 200-400 parts of water.

[0018] Unless otherwise specified, all raw materials used in this invention are commercially available products known to those skilled in the art or products prepared by methods known to those skilled in the art.

[0019] The raw materials for preparing the elastic fire-retardant coating of the present invention, by weight, include 40-50 parts of a coating matrix; the raw materials for preparing the coating matrix include a mixed emulsion, an initiator, and an acrylic solution; the initiator is preferably potassium persulfate; the acrylic solution is preferably an aqueous acrylic solution; the mass concentration of the acrylic solution is preferably 5-20%; the mass ratio of the mixed emulsion, initiator, and acrylic solution is 100:(0.5-3):(1-3). As one embodiment of the present invention, the mass concentration of the acrylic solution can be 5%, 8%, 10%, 12%, 15%, 18%, or 20%. By adding the acrylic solution, the double bonds of acrylic acid can be opened and copolymerized with the double bonds of vinyl silicone oil.

[0020] In this invention, the raw materials for preparing the mixed emulsion, by mass parts, include the following components: 1-2 parts of γ-aminopropyltriethoxysilane, 10-20 parts of hydroxyl-terminated vinyl silicone oil, 10-25 parts of dimethylolpropionic acid, 40-60 parts of isophorone diisocyanate, 120-200 parts of polyether polyol, 1-5 parts of organometallic compound solution, 20-30 parts of methyl ethyl ketone, 1-5 parts of triethylamine, and 200-400 parts of water.

[0021] The raw materials for preparing the mixed emulsion of the present invention include 1-2 parts by mass of γ-aminopropyltriethoxysilane (KH-550). In one embodiment of the present invention, the mass fraction of γ-aminopropyltriethoxysilane can be 1 part, 1.2 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.8 parts, or 2 parts. The addition of γ-aminopropyltriethoxysilane in the present invention serves two purposes: firstly, the single-terminal amino group can terminate the reaction, acting as a chain terminator; secondly, the introduced silicon element generates SiO2 during combustion, greatly strengthening the char layer and preventing the coating from melting and dripping during heating; and thirdly, it can also act as an organosilicon modifier, introducing siloxane segments into the polyurethane backbone through the reaction of amino groups with -NCO, significantly improving the hydrophobicity, smoothness, weather resistance, and heat resistance of the coating film.

[0022] The raw materials for preparing the mixed emulsion of the present invention include 10-20 parts of hydroxyl-terminated vinyl silicone oil, based on 1-2 parts by mass of γ-aminopropyltriethoxysilane; the hydroxyl-terminated vinyl silicone oil is preferably vinyl hydroxyl silicone oil; the mass percentage of hydroxyl groups in the hydroxyl-terminated vinyl silicone oil is preferably 8%; the type of the hydroxyl-terminated vinyl silicone oil is preferably 207V-2.5. As one embodiment of the present invention, the mass fraction of the hydroxyl-terminated vinyl silicone oil can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 parts. The hydroxyl-terminated vinyl silicone oil added in the present invention introduces siloxane segments through the reaction of hydroxyl groups with -NCO, while the terminal vinyl groups provide crosslinking sites.

[0023] The raw materials for preparing the mixed emulsion of the present invention include 10-25 parts of dimethylolpropionic acid (DMPA), based on 1-2 parts by mass of γ-aminopropyltriethoxysilane; the DMPA is preferably sourced from Dongyang Baihang Chemical Co., Ltd. As one embodiment of the present invention, the mass fraction of the DMPA can be 10, 12, 14, 15, 16, 18, 20, 22, 24, or 25 parts. The DMPA added in the present invention is a key water-based raw material. After the carboxyl group (-COOH) in the DMPA is neutralized by triethylamine, it enables the polymer chain to become hydrophilic, thereby emulsifying in water.

[0024] The raw materials for preparing the mixed emulsion of the present invention include 40-60 parts of isophorone diisocyanate (IPDI), based on 1-2 parts by mass of γ-aminopropyltriethoxysilane. In one embodiment of the present invention, the mass fraction of isophorone diisocyanate can be 40, 42, 44, 45, 46, 48, 50, 52, 53, 55, 56, 58, or 60 parts. The present invention provides a rigid structure and crosslinking points by adding isophorone diisocyanate; its -NCO group is the starting point of the entire polyurethane reaction, determining the hardness and strength of the coating film.

[0025] The raw materials for preparing the mixed emulsion of the present invention, based on 1-2 parts by mass of γ-aminopropyltriethoxysilane, include 120-200 parts of polyether polyol; the polyether polyol is preferably a highly active polyether polyol, more preferably a highly active polyether polyol 330N. As one embodiment of the present invention, the mass fraction of the polyether polyol can be 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, or 200 parts. The present invention provides flexibility and low-temperature resistance by adding polyether polyol, which reacts with IPDI to form a flexible long-chain backbone of polyurethane.

[0026] The raw materials for preparing the mixed emulsion of the present invention, based on 1-2 parts by mass of γ-aminopropyltriethoxysilane, include 1-5 parts by mass of an organometallic compound solution; the organometallic compound in the organometallic compound solution is preferably organotin or organobismuth, more preferably dibutyltin dilaurate, bismuth neodecanoate, bismuth laurate, or bismuth isooctanoate; the solvent in the organometallic compound solution is preferably xylene; the xylene is preferably dehydrated; the mass concentration of the organometallic compound solution is preferably 0.1-5%. As one embodiment of the present invention, the mass parts of the organometallic compound solution can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts; the mass concentration of the organometallic compound solution can be 0.1%, 0.2%, 0.4%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%. The present invention incorporates an organometallic compound solution as a catalyst to efficiently catalyze the polycondensation reaction between isocyanates (-NCO) and hydroxyl groups (-OH), significantly shortening the reaction time and reducing the reaction temperature.

[0027] The raw materials for preparing the mixed emulsion of the present invention include 20-30 parts of methyl ethyl ketone (MEK), based on 1-2 parts by mass of γ-aminopropyltriethoxysilane; the MEK is preferably urethane-grade MEK. In one embodiment of the present invention, the mass fraction of methyl ethyl ketone can be 20, 21, 22, 23, 24, 25, 26, 26.5, 27, 28, 29, or 30 parts. The present invention uses methyl ethyl ketone as a reaction solvent, which can dissolve the raw materials and adjust the viscosity, provide a homogeneous reaction environment, and, through subsequent rotary evaporation removal, will not affect the performance of the coating.

[0028] The raw materials for preparing the mixed emulsion of the present invention include 1 to 5 parts triethylamine, based on 1 to 2 parts by mass of γ-aminopropyltriethoxysilane. In one embodiment of the present invention, the mass of triethylamine can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts. The present invention uses triethylamine as a neutralizing agent, which can neutralize the carboxyl group (-COOH) introduced by DMPA, converting it into a carboxylate (-COO-), thereby improving water dispersibility.

[0029] The raw materials for preparing the mixed emulsion of the present invention include 200-400 parts of water, based on 1-2 parts by mass of γ-aminopropyltriethoxysilane; the water is preferably deionized water. As one embodiment of the present invention, the mass of the water can be 200, 220, 240, 250, 260, 280, 300, 320, 340, 350, 360, 380, or 400 parts. The present invention, by adding water as a solvent, ensures thorough mixing of the raw materials.

[0030] The raw materials for preparing the elastic fire-retardant coating of the present invention include 10-25 parts of ammonium polyphosphate (APP), based on 40-50 parts by weight of the coating matrix; the degree of polymerization of the ammonium polyphosphate is preferably >800; the ammonium polyphosphate is preferably FR CROS589 produced by Budenheim AG. In one embodiment of the present invention, the mass fraction of the ammonium polyphosphate can be 10, 12, 15, 18, 20, 22, or 25 parts. The present invention, by adding ammonium polyphosphate, releases polyphosphoric acid upon thermal decomposition at high temperature, catalyzing the dehydration and esterification of a char-forming agent (such as pentaerythritol) into char, while simultaneously releasing gas to cause the char layer to expand, thereby forming a fire-retardant layer and significantly improving the flame-retardant performance of the coating.

[0031] The raw materials for preparing the elastic fire-retardant coating of the present invention include 10-30 parts of a charring agent, based on 40-50 parts by weight of the coating matrix; the charring agent is preferably pentaerythritol or pentaerythritol phosphate (PEPA). In one embodiment of the present invention, the charring agent can be 10, 12, 15, 18, 20, 22, 25, 28, or 30 parts by weight. The present invention improves the flame-retardant performance of the coating by adding a charring agent to the coating, which forms a robust and porous expanded char layer at high temperatures.

[0032] The raw materials for preparing the elastic fire-retardant coating of the present invention include 2 to 10 parts of water, based on a coating matrix weight of 40 to 50 parts; the water is preferably deionized water. In one embodiment of the present invention, the water weight can be 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts. The present invention uses water as a solvent to achieve mixing of the raw materials.

[0033] The raw materials for preparing the elastic fire-retardant coating of the present invention include 5-20 parts of a gas generating agent, based on 40-50 parts by weight of the coating matrix; the gas generating agent is preferably melamine, a melamine derivative, or p-toluenesulfonate aminourea. In one embodiment of the present invention, the mass fraction of the gas generating agent can be 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, or 20 parts. The present invention provides the gas source required for liquefied coatings by adding a gas generating agent, which decomposes into gas at high temperature.

[0034] The raw materials for preparing the elastic fire-retardant coating of the present invention include 3-10 parts of additives, based on 40-50 parts by weight of the coating matrix; the additives preferably include pigments, dispersants, and thickeners; the pigment is preferably titanium dioxide; the dispersant is preferably an aqueous dispersant, more preferably BYK-190 produced by BYK Chemicals; the thickener is preferably a WT-102 solution with a mass concentration of 50%; the WT-102 in the WT-102 solution is preferably an associative polyurethane thickener WT-102 produced by Hemings Chemical Company; the solvent in the WT-102 solution is preferably DPM (dipropylene glycol methyl ether); the mass ratio of the pigment, dispersant, and thickener is preferably (1-10):(0.5-2):(0.05-0.3). In one embodiment of the present invention, the mass fraction of the additive can be 5 parts, 6 parts, 8 parts, or 10 parts; the mass ratio of the pigment, dispersant, and thickener can be (3~6):(1~1.5):(0.08~0.15), or even 5:1:0.1. By adding additives, the present invention can adjust the color and viscosity of the elastic fire-retardant coating, thereby further improving the practicality of the elastic fire-retardant coating.

[0035] The raw materials for preparing the elastic fire-retardant coating of the present invention include 2-10 parts of a crosslinking agent, based on 40-50 parts by weight of the coating matrix; the crosslinking agent is preferably an aziridine crosslinking agent. As one embodiment of the present invention, the mass fraction of the crosslinking agent can be 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts. By adding an aziridine crosslinking agent, the present invention can form a dense three-dimensional crosslinked network in the coating film, thereby significantly improving the final performance of the coating film.

[0036] This invention incorporates γ-aminopropyltriethoxysilane. Firstly, the single-terminal amino group acts as a chain terminator. Secondly, the introduced silicon generates SiO2 during combustion, significantly strengthening the char layer and preventing the coating from melting and dripping under heat. It also acts as an organosilicon modifier, introducing siloxane segments into the polyurethane backbone through the reaction of amino groups with -NCO, greatly improving the coating's hydrophobicity, smoothness, weather resistance, and heat resistance. Hydroxyl-terminated vinyl silicone oil introduces siloxane segments through the reaction of hydroxyl groups with -NCO, while the terminal vinyl groups provide crosslinking sites. Dimethylolpropionic acid (DMPA) is a key waterborne raw material; the carboxyl group (-COOH) in DMPA is neutralized by triethylamine, giving the polymer chain hydrophilicity, thus enabling emulsification in water. The addition of isophorone diisocyanate provides a rigid structure and crosslinking points; its -NCO group is the starting point for the entire polyurethane reaction, determining the coating's hardness and strength. Polyether polyol provides flexibility and low-temperature resistance, reacting with IPDI to form the flexible long-chain backbone of the polyurethane. Organometallic compounds... The solution acts as a catalyst, efficiently catalyzing the polycondensation reaction between isocyanates (-NCO) and hydroxyl groups (-OH), significantly shortening the reaction time and lowering the reaction temperature. Triethylamine, as a neutralizing agent, neutralizes the carboxyl groups (-COOH) introduced by DMPA, converting them into carboxylates (-COO-), thereby improving water dispersibility. Ammonium polyphosphate decomposes at high temperatures, releasing polyphosphoric acid, which catalyzes the dehydration and esterification of charring agents (such as pentaerythritol) into char, simultaneously releasing gas that expands the char layer, forming a fire-retardant layer and significantly improving the flame-retardant properties of the coating. The charring agent forms a robust and porous expanded char layer at high temperatures, further enhancing the flame-retardant properties of the coating. Adding admixtures can adjust the curing speed and viscosity of the elastic fire-retardant coating, further improving its practicality. Adding a gas generator, which decomposes into gas at high temperatures, provides the necessary gas source for liquefying the coating. Adding a aziridine crosslinking agent allows the formation of a dense three-dimensional crosslinked network in the coating film, significantly improving the final performance of the film.

[0037] The elastic fire-retardant coating provided by this invention forms an elastic fire-retardant coating with good adhesion, as well as excellent flexibility, water resistance, fire resistance, and tear strength. It can provide fire protection and adapt to the dynamic working conditions of structural components.

[0038] This invention also provides a method for preparing the elastic fire-retardant coating described above, comprising the following steps: (1) Mix methyl ethyl ketone and isophorone diisocyanate to obtain a premix; (2) Mix polyether polyol, dimethylolpropionic acid and hydroxyl-terminated vinyl silicone oil, then add premixed liquid, then add organometallic compound solution under protective atmosphere to carry out polymerization reaction, and finally add γ-aminopropyltriethoxysilane to obtain a mixture; (3) Mix triethylamine and water to obtain a triethylamine solution, then add the mixture obtained in step (2) to the triethylamine solution for emulsification, and finally perform rotary evaporation to obtain a mixed emulsion; (4) The mixed emulsion, initiator and acrylic solution obtained in step (3) are mixed and then subjected to polymerization reaction to obtain the coating matrix; (5) Mix the coating matrix, ammonium polyphosphate, charring agent, gas generator, additive and water obtained in step (4), and then add crosslinking agent to obtain elastic fireproof coating.

[0039] The present invention mixes methyl ethyl ketone and isophorone diisocyanate to obtain a premix.

[0040] The present invention does not have any special limitations on the specific operation and time of mixing methyl ethyl ketone and isophorone diisocyanate. Based on the technical common sense of those skilled in the art, it is sufficient to mix and dissolve them until they are transparent.

[0041] After obtaining the premixed solution, the present invention mixes polyether polyol, dimethylolpropionic acid and hydroxyl-terminated vinyl silicone oil, then adds the premixed solution, then adds an organometallic compound solution under a protective atmosphere to carry out a polymerization reaction, and finally adds γ-aminopropyltriethoxysilane to obtain a mixture.

[0042] In this invention, the polyether polyol is preferably subjected to vacuum dehydration first; the temperature of the vacuum dehydration is preferably 80-90°C, more preferably 85°C; the time of the vacuum dehydration is preferably 2-4 hours, more preferably 3 hours. This invention does not have a specific limitation on the vacuum degree of the vacuum dehydration; based on the technical knowledge of those skilled in the art, it is sufficient to remove residual water from the polyether polyol. This invention can remove impurities from the polyether polyol through vacuum dehydration.

[0043] In this invention, the preferred method for mixing the polyether polyol, dimethylolpropionic acid, and hydroxyl-terminated vinyl silicone oil is to first mix the polyether polyol and dimethylolpropionic acid, and then add the hydroxyl-terminated vinyl silicone oil; the preferred temperature for mixing the polyether polyol and dimethylolpropionic acid is ≤60°C. This invention does not impose any special limitations on the specific operation and time of the mixing; it can be determined based on the technical knowledge of those skilled in the art, as long as the mixing is uniform.

[0044] In this invention, the premixed liquid is preferably added by dripping. This invention does not impose a specific limitation on the dripping rate; it can be determined based on the technical knowledge of those skilled in the art. By using a dripping method, this invention achieves a more uniform mixing.

[0045] In this invention, the protective atmosphere is preferably nitrogen. There is no particular limitation on the concentration of nitrogen, as long as it ensures that no impurities are introduced.

[0046] In this invention, the organometallic compound solution is preferably added dropwise under stirring conditions; the temperature of the mixture during addition is preferably 75-85°C, more preferably 80°C. This invention does not impose a specific limitation on the stirring rate, as long as it is sufficient to ensure the organometallic compound solution is mixed uniformly.

[0047] In this invention, the polymerization reaction temperature is preferably 75-85°C; the polymerization reaction is preferably carried out under ultrasonic conditions; and the ultrasonic frequency is preferably 10-30 MHz. As one embodiment of this invention, the polymerization reaction temperature can be 75°C, 80°C, or 85°C; and the ultrasonic frequency can be 10 MHz, 15 MHz, 20 MHz, 25 MHz, or 30 MHz. This invention does not have a specific limitation on the polymerization reaction time; the isocyanate content is measured every 30 minutes until it stabilizes at 1% (excluding MEK and xylene) and no longer decreases.

[0048] In this invention, the γ-aminopropyltriethoxysilane is preferably added dropwise; the addition temperature of the γ-aminopropyltriethoxysilane is preferably ≤50°C. After adding the γ-aminopropyltriethoxysilane, it is preferable to continue adding the γ-aminopropyltriethoxysilane until no isocyanate is detected in the mixture.

[0049] After obtaining the mixture, the present invention mixes triethylamine and water to obtain a triethylamine solution, then adds the mixture to the triethylamine solution for emulsification, and finally performs rotary evaporation to obtain a mixed emulsion.

[0050] The present invention does not have any special limitations on the mixing of triethylamine and water or the method of adding the mixture. Conventional mixing and addition methods can be used to ensure that the mixture is homogeneous.

[0051] In this invention, the emulsification method is preferably high-speed shear dispersion emulsification; the emulsification speed is preferably 2000~3000 r / min; the emulsification time is preferably 10~30 min; and the emulsification temperature is preferably room temperature.

[0052] This invention does not impose specific limitations on the temperature and time of the rotation; based on the technical knowledge of those skilled in the art, it is sufficient to remove residual solvent. In one embodiment of this invention, the rotary evaporation temperature can be 80-90°C, and the rotary evaporation time can be 2-3 hours.

[0053] After obtaining the mixed emulsion, the present invention mixes the mixed emulsion, initiator and acrylic solution and then carries out a polymerization reaction to obtain the coating matrix.

[0054] In this invention, the preferred method for mixing the mixed emulsion, initiator, and acrylic solution is to add the initiator to the mixed emulsion, then heat it to 40-60°C before adding the acrylic solution dropwise. This invention does not impose any specific limitation on the dropping rate of the acrylic solution; it can be determined based on the technical knowledge of those skilled in the art.

[0055] In this invention, the polymerization reaction temperature is preferably 40~60℃; the polymerization reaction time is preferably 1~5h. As one embodiment of this invention, the polymerization reaction temperature can be 40℃, 45℃, 50℃, 55℃ or 60℃; the polymerization reaction time can be 1h, 2h, 3h, 4h or 5h.

[0056] After obtaining the coating matrix, the present invention mixes the coating matrix, ammonium polyphosphate, charring agent, gas generator, additives and water, and then adds a crosslinking agent to obtain an elastic fireproof coating.

[0057] In this invention, the preferred method for mixing the coating matrix, ammonium polyphosphate, charring agent, gas generator, additives, and water is grinding. This invention does not impose specific limitations on the grinding operation, as long as the particle size of the mixed product meets the requirements. In this invention, the particle size of the mixed product is preferably ≤40μm. By controlling the particle size of the product, this invention helps to further improve the density of the coating after application.

[0058] The present invention does not impose any special limitations on the method of adding the crosslinking agent; any conventional method that can ensure uniform mixing is acceptable.

[0059] In this invention, the crosslinking agent is preferably added during the application of the elastic fire-retardant coating. This invention avoids problems such as premature curing of the coating during storage by controlling the timing of the crosslinking agent's addition.

[0060] The preparation method provided by this invention is easy to control the quality of the finished product, has low cost, and does not require high-end equipment, making it suitable for large-scale industrial application.

[0061] The present invention also provides the application of the elastic fire-retardant coating described in the above technical solution or the elastic fire-retardant coating described in the above technical solution in the field of functional materials.

[0062] In this invention, the preferred application method is as follows: the substrate is mounted on a casting machine, and then an elastic fire-retardant coating is applied to the substrate surface using a casting method. Each application is 0.4-0.5 mm thick, and the coating is dried after each application until the total thickness reaches 2-3 mm, forming an elastic fire-retardant coating. This invention does not impose specific limitations on the drying operation and parameters; drying can be performed using methods well-known to those skilled in the art. By employing the above method, this invention can precisely control the thickness of the elastic fire-retardant coating and further improve the adhesion between the elastic fire-retardant coating and the substrate.

[0063] The present invention preferably further includes pressing a release film onto the surface of the elastic fire-retardant coating; the thickness of the release film is preferably 0.2~0.25mm. The present invention does not have a specific limitation on the specific source of the release film; commercially available release films well known to those skilled in the art can be used. The present invention does not have a specific limitation on the specific pressing operation; it can be determined based on the technical common sense of those skilled in the art.

[0064] In one embodiment of the present invention, when the substrate is fiberglass mat, the application method is as follows: The fiberglass mat is wound around a casting film machine, and the two ends are bonded together. Then, an elastic fire-retardant coating is mixed evenly with a surface tension modifier. Next, the elastic fire-retardant coating is applied to the surface of the fiberglass mat using a casting method, with each application being 0.4-0.5 mm thick. After each application, the coating is dried until the total thickness is 2-3 mm, forming an elastic fire-retardant coating layer. Subsequently, a release film is pressed onto the surface of the elastic fire-retardant coating to obtain a fire-retardant coating roll. Finally, the fire-retardant coating roll is cut into slits, and the slits are edge-rolled and glued to the cable using elastic fire-retardant adhesive to obtain a cable fire-retardant coating. This invention, by adding a surface tension modifier to the elastic fire-retardant coating, ensures that the coating does not completely penetrate the fiberglass mat. The cable fire-retardant coating is then prepared using a flexible roll application method, avoiding the problem of uneven thickness caused by spray coating.

[0065] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0066] Example 1 An elastic fire-retardant coating, comprising the following components by weight: 45 parts coating matrix, 20 parts ammonium polyphosphate, 10 parts pentaerythritol, 10 parts melamine, 4 parts water, 4 parts crosslinking agent, and 6.1 parts additives; wherein the degree of polymerization of the ammonium polyphosphate is >800, and the ammonium polyphosphate is FRCROS589 manufactured by Budenheim AG; the additives are pigment, dispersant, and thickener, wherein the pigment is titanium dioxide, the dispersant is BYK-190 manufactured by BYK Chemicals, and the thickener is a 50% (w / w) WT-102 solution, wherein the WT-102 in the WT-102 solution is an associative polyurethane thickener WT-102 manufactured by Hemings AG, and the solvent in the WT-102 solution is DPM; the mass ratio of the pigment, dispersant, and thickener is 5:1:0.1; and the crosslinking agent is an aziridine crosslinking agent. The raw materials for preparing the coating matrix are a mixed emulsion, an initiator, and an acrylic solution; the mass ratio of the mixed emulsion, initiator, and acrylic solution is 100:2:2; the initiator is potassium persulfate, and the acrylic solution is a 10% (w / w) aqueous solution of acrylic acid; The raw materials for preparing the mixed emulsion, by mass parts, are as follows: 1.5 parts γ-aminopropyltriethoxysilane, 15 parts hydroxyl-terminated vinyl silicone oil, 18 parts dimethylolpropionic acid, 53 parts isophorone diisocyanate, 165 parts polyether polyol, 3 parts organometallic compound solution, 26.5 parts methyl ethyl ketone, 3 parts triethylamine, and 300 parts water; wherein the γ-aminopropyltriethoxysilane is KH-550, the hydroxyl-terminated vinyl silicone oil is vinyl hydroxyl silicone oil (hydroxyl content of 8% by mass, model 207V-2.5), the dimethylolpropionic acid is from Dongyang Baihang Chemical Co., Ltd., the polyether polyol is 330N, the organometallic compound solution is a xylene solution of dibutyltin dilaurate with a mass concentration of 1%, and the methyl ethyl ketone is urethane grade MEK; The preparation method of the elastic fire-retardant coating includes the following steps: (1) Mix and dissolve methyl ethyl ketone and isophorone diisocyanate until transparent to obtain a premixed solution; (2) The polyether polyol was vacuum dehydrated at 85°C for 3 hours, then dimethylolpropionic acid was added and mixed evenly. The temperature was then lowered to below 60°C and hydroxyl-terminated vinyl silicone oil was added and mixed evenly. Then, the premixed liquid was added dropwise and mixed evenly. Nitrogen gas was then introduced and the temperature was controlled at 80°C under nitrogen protection. Subsequently, an organometallic compound solution was added dropwise and stirred. At the same time, the polymerization reaction was carried out under ultrasonic conditions (ultrasonic frequency of 20MHz). The isocyanate content was measured every 30 minutes until it stabilized at 1% (excluding MEK and xylene) and no longer decreased. Finally, the temperature was lowered to 50°C and γ-aminopropyltriethoxysilane was added dropwise. After the isocyanate was no longer detected, the mixture was obtained. (3) Mix triethylamine and water to obtain a triethylamine solution, then add the mixture obtained in step (2) to the triethylamine solution for high-speed shear emulsification, and finally remove MEK and xylene by rotary evaporation to obtain a mixed emulsion; (4) Add an initiator to the mixed emulsion obtained in step (3), then heat to 50°C and add acrylic acid solution dropwise. Polymerize at 50°C for 2 hours to obtain the coating matrix; (5) The coating matrix, ammonium polyphosphate, melamine, pentaerythritol, additives and water obtained in step (4) are mixed and ground until the particle size is ≤40μm. Then, a crosslinking agent is added to obtain an elastic fireproof coating.

[0067] Example 2 An elastic fire-retardant coating, comprising the following components by weight: 45 parts coating matrix, 20 parts ammonium polyphosphate, 20 parts pentaerythritol phosphate, 5 parts p-toluenesulfonic acid aminourea, 4 parts water, 4 parts crosslinking agent, and 11.1 parts additives; wherein the degree of polymerization of the ammonium polyphosphate is >800, and the ammonium polyphosphate is FR CROS589 manufactured by Budenheim AG; the additives are pigment, dispersant, and thickener, wherein the pigment is titanium dioxide, the dispersant is BYK-190 manufactured by BYK Chemicals, and the thickener is a 50% (w / w) WT-102 solution, wherein the WT-102 in the WT-102 solution is an associative polyurethane thickener WT-102 manufactured by Hemings AG, and the solvent in the WT-102 solution is DPM; the mass ratio of the pigment, dispersant, and thickener is 5:1:0.1; and the crosslinking agent is an aziridine crosslinking agent. The raw materials for preparing the coating matrix are a mixed emulsion, an initiator, and an acrylic solution; the mass ratio of the mixed emulsion, initiator, and acrylic solution is 100:2:2; the initiator is potassium persulfate, and the acrylic solution is a 10% (w / w) aqueous solution of acrylic acid; The raw materials for preparing the mixed emulsion, by mass parts, are as follows: 1.5 parts γ-aminopropyltriethoxysilane, 15 parts hydroxyl-terminated vinyl silicone oil, 18 parts dimethylolpropionic acid, 53 parts isophorone diisocyanate, 165 parts polyether polyol, 3 parts organometallic compound solution, 26.5 parts methyl ethyl ketone, 3 parts triethylamine, and 300 parts water; wherein the γ-aminopropyltriethoxysilane is KH-550, the hydroxyl-terminated vinyl silicone oil is hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer (207V-2.5), the hydroxyl content of the hydroxyl-terminated vinyl silicone oil is 8%, the dimethylolpropionic acid is from Dongyang Baihang Chemical Co., Ltd., the polyether polyol is 330N, the organometallic compound solution is a 1% xylene solution of dibutyltin dilaurate, and the methyl ethyl ketone is urethane grade MEK; The preparation method of the elastic fire-retardant coating includes the following steps: (1) Mix and dissolve methyl ethyl ketone and isophorone diisocyanate until transparent to obtain a premixed solution; (2) The polyether polyol was vacuum dehydrated at 85°C for 3 hours, then dimethylolpropionic acid was added and mixed evenly. The temperature was then lowered to below 60°C and hydroxyl-terminated vinyl silicone oil was added and mixed evenly. Then, the premixed liquid was added dropwise and mixed evenly. Nitrogen gas was then introduced and the temperature was controlled at 80°C under nitrogen protection. Subsequently, an organometallic compound solution was added dropwise and stirred. At the same time, the polymerization reaction was carried out under ultrasonic conditions (ultrasonic frequency of 20MHz). The isocyanate content was measured every 30 minutes until it stabilized at 1% (excluding MEK and xylene) and no longer decreased. Finally, the temperature was lowered to 50°C and γ-aminopropyltriethoxysilane was added dropwise. After the isocyanate was no longer detected, the mixture was obtained. (3) Mix triethylamine and water to obtain a triethylamine solution, then add the mixture obtained in step (2) to the triethylamine solution for high-speed shear emulsification, and finally remove MEK and xylene by rotary evaporation to obtain a mixed emulsion; (4) Add an initiator to the mixed emulsion obtained in step (3), then heat to 50°C and add acrylic acid solution dropwise. Polymerize at 50°C for 2 hours to obtain the coating matrix; (5) The coating matrix obtained in step (4), ammonium polyphosphate, pentaerythritol phosphate, p-toluenesulfonate aminourea, additives and water are mixed and ground until the particle size is ≤40μm, and then a crosslinking agent is added to obtain an elastic fireproof coating.

[0068] Performance testing A 150-gram glass fiber mat is wound around a casting film machine and bonded at both ends. After adding a crosslinking agent to obtain an elastic fire-retardant coating in Example 1, the coating is scraped onto the surface of the glass mat using a casting method. After each scraping, the coating is dried in an oven until the thickness of the coating reaches 2 mm. Finally, a release film is pressed onto the coating using a laminating device to obtain a fire-retardant coating roll.

[0069] Figure 1 A side view of the fire-retardant coating being peeled off from the surface of the fire-retardant felt roll. Figure 2 This is a frontal view of the fire-retardant coating being peeled off from the surface of the fire-retardant felt roll. (Source: [Original Source Name]) Figure 1 and Figure 2 It can be seen that after the coating on the surface of the fire-retardant coating roll is peeled off, the coating does not cause any damage or corrosion to the glass mat, indicating that the elastic fire-retardant coating provided by the present invention does not affect the performance of the substrate.

[0070] Figure 3 This is a picture of the fire-retardant coating roll after it has been bent. Figure 4This is a picture of the fire-retardant coating roll after it has been bent and springed back to its original shape. Figure 5 This is a picture of the fire-retardant coating roll after it has been bent twice. Figure 6 This is a side view of the fire-retardant coating roll being peeled off after it has springs back to its original shape following a second bend. Figures 3-6 It can be seen that after the elastic fireproof coating provided by the present invention forms a coating on the surface of glass felt, the coating does not crack or peel off after multiple bends, indicating that the coating formed by the elastic fireproof coating provided by the present invention has good adhesion performance on the substrate surface; at the same time, after multiple bends, the peeled coating still has good integrity and flexibility.

[0071] The coating on the surface of the fire-retardant coating roll was peeled off, and then the elongation at break of the peeled coating was tested. The test was conducted using an electronic universal testing machine according to the test standard GB / T 3923.1-2013, and the result was: elongation at break ≥200%.

[0072] The water resistance of the coating on the surface of the fire-retardant coating roll was tested. The test method was as follows: the fire-retardant coating roll was completely immersed in water at room temperature for 24 hours, and then taken out for observation. The results showed that there was no change after 24 hours of immersion, indicating that the coating formed by the elastic fire-retardant coating provided by the present invention has good water resistance.

[0073] The fire resistance performance of the coating on the surface of the fire-retardant coating roll was tested. A fire-retardant coating roll with a coating thickness of 3 mm was prepared according to the aforementioned method. The coating on the surface of the fire-retardant coating roll was peeled off to obtain a 3 mm thick coating. Finally, the fire resistance performance of the coating was tested according to the GB14907 standard. The result was that the coating met the 2-hour fire resistance standard, indicating that the coating formed by the elastic fire-retardant coating provided by the present invention has excellent fire resistance performance.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An elastic fire-retardant coating, characterized by, The raw materials for preparing the elastic fireproof coating include the following components in mass fraction: 40-50 parts of a coating matrix, 10-25 parts of ammonium polyphosphate, 10-30 parts of a char-forming agent, 5-20 parts of a gas generating agent, 2-10 parts of water, 2-10 parts of a cross-linking agent, and 3-10 parts of an additive; The raw materials for preparing the coating matrix include a mixed emulsion, an initiator, and an acrylic acid solution; the mass ratio of the mixed emulsion, the initiator, and the acrylic acid solution is 100: (0.5-3): (1-3); The raw materials for preparing the mixed emulsion include the following components in mass fraction: 1-2 parts of γ-aminopropyl triethoxysilane, 10-20 parts of hydroxyl-terminated vinyl silicone oil, 10-25 parts of dimethylol propionic acid, 40-60 parts of isophorone diisocyanate, 120-200 parts of polyether polyol, 1-5 parts of an organic metal compound solution, 20-30 parts of methyl ethyl ketone, 1-5 parts of triethylamine, and 200-400 parts of water.

2. The elastic fireproof coating according to claim 1, characterized in that, The char-forming agent is pentaerythritol or pentaerythritol phosphate.

3. The elastic fireproof coating according to claim 1, characterized in that, The gas generating agent is melamine, a melamine derivative, or p-toluenesulfonic acid amino urea.

4. The elastomeric fireproofing coating of claim 1, wherein, The additive includes pigments, dispersants, and thickening agents.

5. The elastic fireproof coating according to claim 4, characterized in that, The mass ratio of the pigments, the dispersants, and the thickening agents is (1-10):(0.5-2):(0.05-0.3).

6. The elastomeric fireproofing coating of claim 1, wherein, The cross-linking agent is an aziridine cross-linking agent.

7. The elastomeric fireproofing coating of claim 1, wherein, The initiator is potassium persulfate; the acrylic acid solution is an aqueous acrylic acid solution; the mass concentration of the acrylic acid solution is 5-20%.

8. The elastomeric fireproofing coating of claim 1, wherein, The organic metal compound in the organic metal compound solution is an organic tin or an organic bismuth; the mass concentration of the organic metal compound solution is 0.1-5%.

9. A process for the preparation of the elastic fireproof coating according to any one of claims 1 to 8, characterized by, The method includes the following steps: (1) mixing methyl ethyl ketone and isophorone diisocyanate to obtain a premix; (2) mixing polyether polyol, dimethylol propionic acid, and hydroxyl-terminated vinyl silicone oil, then adding the premix, followed by adding an organic metal compound solution under a protective atmosphere for polymerization, and finally adding γ-aminopropyl triethoxysilane to obtain a mixture; (3) mixing triethylamine and water to obtain a triethylamine solution, then adding the mixture obtained in step (2) to the triethylamine solution for emulsification, and finally performing rotary evaporation to obtain a mixed emulsion; (4) mixing the mixed emulsion obtained in step (3), an initiator, and an acrylic acid solution for polymerization to obtain a coating matrix; (5) mixing the coating matrix obtained in step (4), ammonium polyphosphate, a char-forming agent, a gas generating agent, an additive, and water, and then adding a cross-linking agent to obtain an elastic fireproof coating.

10. Use of the elastic fireproof coating of any one of claims 1-8 or prepared by the method of claim 9 in the field of functional materials.

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