A luminescent heat-resistant and flame-retardant coating, its preparation method and application

Abstract

A luminescent heat-resistant and flame-retardant coating, its preparation method and application belong to the technical field of heat-resistant and flame-retardant materials. The coating comprises the following raw materials in percentage by weight: 30-40% of a first hydroxy acrylic resin, 10-15% of a second hydroxy acrylic resin, 5-10% of an amino resin, 20-30% of a modified flame retardant, 2-5% of a coated luminescent powder, 5-10% of hollow glass microspheres and the balance of a solvent; wherein, the modified flame retardant is an inorganic flame retardant modified by an amino silane coupling agent and hexachlorocyclotriphosphazene; the coated luminescent powder comprises an inner layer and a coating layer, the inner layer is strontium aluminate doped with europium and dysprosium, and the coating layer is alumina. The luminescent heat-resistant and flame-retardant coating of the invention has excellent flame retardant and smoke suppression effects, good heat resistance, water resistance and mechanical properties, and at the same time, the luminescent performance of the coating is stable, and it is suitable for use in fire-fighting equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat-resistant and flame-retardant materials, and particularly relates to a luminescent heat-resistant and flame-retardant coating, a preparation method thereof, and an application thereof. Background Art

[0002] Fire-fighting equipment refers to equipment used for extinguishing fires, preventing fires, and dealing with fire accidents. Common fire-fighting equipment includes fire-fighting suits, portable fire extinguishers, fire blankets, smoke-proof masks, escape ropes, etc. Since fire-fighting equipment is usually used in high-temperature fire environments, it needs to have excellent heat resistance and flame retardancy. In addition, when a fire occurs, the power system often collapses, and materials that can emit light are needed to guide the way. The existing fire-fighting equipment has poor flame retardancy and fire prevention performance, resulting in easy combustion when encountering fire, serving as a medium for the spread of fire, and causing damage to fire-fighting equipment. Therefore, coating fire-fighting equipment with a coating that simultaneously has excellent heat resistance, flame retardancy, and luminescence functions can effectively reduce the disasters caused by fires.

[0003] At present, the common preparation method of flame-retardant coatings at home and abroad is to directly add flame retardants to the coatings, but the existing common flame retardants have low flame retardancy efficiency and poor compatibility with the coating system. In addition, the common method for preparing flame-retardant luminescent coatings is to mix flame retardants and luminescent powders together. Due to reasons such as poor water resistance, the luminescent powders usually become ineffective, causing the luminescent powders to not emit light or the brightness to decrease.

[0004] Patent CN112322081B discloses an aqueous inorganic flame-retardant luminescent coating. A luminescent layer with a waterproof function is attached to a flame-retardant layer with poor water resistance, which can effectively solve the problem of poor water resistance of the inorganic flame-retardant layer, and at the same time can also avoid the adverse effects of flame retardants on the afterglow intensity and afterglow time. However, the flame retardancy efficiency of this coating is low and the heat resistance is poor. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a luminescent heat-resistant and flame-retardant coating, a preparation method thereof, and an application thereof. The luminescent heat-resistant and flame-retardant coating has excellent flame retardancy and smoke suppression effects, good heat resistance, water resistance, and mechanical properties. At the same time, the luminescence performance of the coating is stable and suitable for use in fire-fighting equipment.

[0006] To achieve the above purpose, according to one aspect of the present invention, there is provided a luminescent heat-resistant and flame-retardant coating, which comprises the following raw materials by weight percentage: 30-40% of a first hydroxy acrylic resin, 10-15% of a second hydroxy acrylic resin, 5-10% of an amino resin, 20-30% of a modified flame retardant, 2-5% of a coated luminescent powder, 5-10% of hollow glass microspheres, and the balance of a solvent; wherein, the modified flame retardant is an inorganic flame retardant modified by an amino silane coupling agent and hexachlorocyclotriphosphazene; the coated luminescent powder comprises an inner layer and a coating layer, the inner layer is strontium aluminate doped with europium and dysprosium, and the coating layer is aluminum oxide.

[0007] In the present invention, in the luminescent heat-resistant and flame-retardant coating, the weight percentage of the first hydroxy acrylic resin is 30-40%. It can be understood that the weight percentage can be any specific value among 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40% or any value within the range of 30-40%. In some embodiments, the mass fraction of hydroxyl groups in the first hydroxy acrylic resin is 2.4-3.0%. It can be understood that the mass percentage can be any specific value among 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0% or any value within the range of 2.4-3.0%. In the present invention, in the luminescent heat-resistant and flame-retardant coating, the weight percentage of the second hydroxy acrylic resin is 10-15%. It can be understood that the weight percentage can be any specific value among 10%, 11%, 12%, 13%, 14%, 15% or any value within the range of 10-15%. In some embodiments, the mass fraction of hydroxyl groups in the second hydroxy acrylic resin is 1.7-2.0%. It can be understood that the mass percentage can be any specific value among 1.7%, 1.8%, 1.9%, 2.0% or any value within the range of 1.7-2.0%.

[0008] The inventors found that in the system of the present invention, by selecting the hydroxy acrylic resins with different hydroxy contents and compounding them in a certain proportion, on the one hand, the reaction rate of free radicals can be ensured, the shrinkage stress of the coating film can be reduced, thereby improving the adhesion of the coating film; on the other hand, the compounding of the two hydroxy acrylic resins can adjust the drying rate of the coating film and ensure that the coating film has appropriate hardness and mechanical properties; at the same time, due to the appropriate hydroxy content, intermolecular hydrogen bonds can be formed between the unreacted amino groups on the surface of the modified flame retardant in the system, further improving the compatibility between the resin system and the modified flame retardant and enhancing the flame retardant effect and coating film performance. However, the contents of the two must be strictly controlled. If the content of the first hydroxy acrylic resin is too high, the water resistance of the coating will deteriorate; if the content of the second hydroxy acrylic resin is too high, the crosslinking density of the system will be too low, reducing the adhesion and mechanical properties of the coating film, and at the same time resulting in poor compatibility between the resin system and the modified flame retardant and poor long-term stability of the system.

[0009] In the present invention, in the luminescent heat-resistant and flame-retardant coating, the weight percentage of the amino resin is 5-10%. It can be understood that the weight percentage can be any specific value among 5%, 6%, 7%, 8%, 9%, 10% or any value within the range of 5-10%. In some embodiments, the amino resin is a methylated high imino melamine resin. The inventor found that by selecting the methylated high imino melamine resin and two kinds of hydroxyl acrylic resins for combination, the heat resistance and water resistance of the coating film can be ensured. Especially after heat treatment for a certain period of time, the water resistance and mechanical properties of the coating film are not affected.

[0010] In the present invention, in the luminescent heat-resistant and flame-retardant coating, the weight percentage of the modified flame retardant is 20-30%. It can be understood that the weight percentage can be any specific value among 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30% or any value within the range of 20-30%. In the present invention, the modified flame retardant is an inorganic flame retardant modified by an amino silane coupling agent and hexachlorocyclotriphosphazene. In some embodiments, the inorganic flame retardant is calcium dihydrogen phosphate and magnesium hydroxide with a mass ratio of 2-3:1. It can be understood that the mass ratio can be any specific value among 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3:1 or any value within the range of 2-3:1. In some embodiments, the modified flame retardant is obtained by first modifying calcium dihydrogen phosphate and magnesium hydroxide with an amino silane coupling agent and then adding hexachlorocyclotriphosphazene for reaction. In the present invention, by compounding calcium dihydrogen phosphate and magnesium hydroxide in proportion and then modifying them with an amino silane coupling agent and hexachlorocyclotriphosphazene to obtain the modified flame retardant, it has the best flame retardancy and smoke suppression effect.

[0011] Surprisingly, in the system of the present invention, by combining two kinds of hydroxyl acrylic resins and the modified flame retardant, the heat resistance of the coating film can be further improved on the premise of ensuring the flame retardancy of the coating film. On the one hand, because the modified flame retardant contains phosphazene compounds, which have better thermal stability itself. In addition, due to the formation of intermolecular hydrogen bonds between the unreacted amino groups on the hydroxyl acrylic resin and the modified flame retardant, it promotes the cross-linking of the molecular chains of the hydroxyl acrylic resin, thereby improving the heat resistance of the coating film.

[0012] In the present invention, in the luminescent heat-resistant and flame-retardant coating, the weight percentage of the coated luminescent powder is 2-5%. It can be understood that the weight percentage can be any specific value among 2%, 3%, 4%, 5% or any value within the range of 2-5%. In the present invention, the coated luminescent powder includes an inner layer and a coating layer. The inner layer is strontium aluminate doped with europium and dysprosium, and the coating layer is alumina. In some embodiments, the coated luminescent powder is obtained by reacting strontium aluminate doped with europium and dysprosium luminescent powder with a soluble aluminum sulfate salt under alkaline conditions. By coating an alumina layer on the surface of the strontium aluminate doped with europium and dysprosium luminescent powder, on the one hand, the water resistance of the luminescent powder is improved, and on the other hand, the luminescent performance of the luminescent powder is ensured.

[0013] In the present invention, in the luminescent heat-resistant and flame-retardant coating, the weight percentage of the hollow glass microspheres is 5-10%. It can be understood that the weight percentage can be any specific value among 5%, 6%, 7%, 8%, 9%, 10% or any value within the range of 5-10%. In some embodiments, the particle size of the hollow glass microspheres is 10-100 μm, and the bulk density is 0.10-0.16 g / cm 3 . Adding a certain amount of hollow glass microspheres to the system of the present invention forms intermolecular hydrogen bonds between the glass microspheres and the hydroxyacrylic resin, further improving the compatibility between the resin system and the glass microspheres, and improving the dispersibility of the glass microspheres in the coating, thereby ensuring that the coating film has excellent heat insulation properties.

[0014] In the present invention, in the luminescent heat-resistant and flame-retardant coating, the solvent is selected from one or more of propylene glycol monomethyl ether acetate, xylene, and butyl acetate.

[0015] According to one aspect of the present invention, there is also provided a method for preparing the luminescent heat-resistant and flame-retardant coating according to any one of the above, comprising the following steps:

[0016] (1) Prepare a modified flame retardant: Disperse an inorganic flame retardant in an ethanol solution, add an amino silane coupling agent, stir well, centrifuge to obtain a solid intermediate product, and add the solid intermediate product to a solution containing hexachlorocyclotriphosphazene, and react under a nitrogen atmosphere to obtain a modified flame retardant;

[0017] (2) Prepare a coated luminescent powder: Disperse strontium aluminate doped with europium and dysprosium in an ethanol solution, add a soluble aluminum sulfate salt, adjust the pH with an alkali solution under uniform stirring, fully react, wash, dry, and calcine to obtain the coated luminescent powder;

[0018] (3) Weigh the modified flame retardant, coated luminescent powder, first hydroxyacrylic resin, second hydroxyacrylic resin, amino resin, hollow glass microspheres and solvent in proportion, and stir evenly to obtain the luminescent heat-resistant and flame-retardant coating.

[0019] In the present invention, in step (1), first, a modified flame retardant is prepared. Specifically, an inorganic flame retardant is dispersed in an ethanol solution, an amino silane coupling agent is added, and after sufficient stirring, a solid intermediate product is obtained by centrifugation. The solid intermediate product is added to a solution in which hexachlorocyclotriphosphazene is dissolved, and the reaction is carried out under a nitrogen atmosphere to obtain the modified flame retardant. In some embodiments, in step (1), the mass ratio of the inorganic flame retardant, the silane coupling agent, and hexachlorocyclotriphosphazene is 1.5 - 2:1:1 - 1.5, preferably 2:1:1.5. In some embodiments, the inorganic flame retardant is dispersed in an ethanol solution, an amino silane coupling agent is added, and after sufficient stirring at 45 - 50 °C for 1.5 - 2 h, a solid intermediate product is obtained by centrifugation. In some embodiments, the solid intermediate product is added to a solution in which hexachlorocyclotriphosphazene is dissolved, and under a nitrogen atmosphere and alkaline conditions, the reaction is carried out at 75 - 80 °C for 5 - 6 h to obtain the modified flame retardant.

[0020] In the present invention, in step (2), a coated luminescent powder is prepared. Specifically, strontium aluminate doped with europium and dysprosium is dispersed in an ethanol solution, a soluble aluminum sulfate salt is added, and under uniform stirring, the pH is adjusted with an alkali solution. After sufficient reaction, it is washed, dried, and calcined to obtain the coated luminescent powder. In some embodiments, in step (2), the mass ratio of the strontium aluminate doped with europium and dysprosium to the soluble aluminum sulfate salt is 1:2 - 3, preferably 1:2.5. In some embodiments, the strontium aluminate doped with europium and dysprosium is dispersed in an ethanol solution, dropped into an ethanol solution of the soluble aluminum sulfate salt, and under uniform stirring, the pH is adjusted to 5 - 6 with an alkali solution. The reaction is carried out at 80 - 85 °C for 5 - 6 h, washed, dried, and calcined to obtain the coated luminescent powder. In the present invention, under alkaline conditions, the soluble aluminum sulfate salt forms Al(OH) 3 and adsorbs on the surface of the strontium aluminate doped with europium and dysprosium, and gradually forms an Al 2 O 3 coating layer.

[0021] In the present invention, in step (3), the modified flame retardant, the coated luminescent powder, the first hydroxy acrylic resin, the second hydroxy acrylic resin, the amino resin, the hollow glass microspheres, and the solvent are weighed in proportion and stirred evenly to obtain the luminescent heat-resistant flame retardant coating.

[0022] According to one aspect of the present invention, there is also provided an application of the above-mentioned luminescent heat-resistant flame retardant coating or the luminescent heat-resistant flame retardant coating prepared according to the above preparation method in fire-fighting equipment.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] (1) By selecting the hydroxy acrylic resins with different hydroxy contents, the present invention can, on the one hand, ensure the reaction rate of free radicals, reduce the shrinkage stress of the coating film, and thus improve the adhesion of the coating film; on the other hand, the compounding of the two hydroxy acrylic resins can adjust the drying rate of the coating film and ensure that the coating film has appropriate hardness and mechanical properties; at the same time, due to the presence of appropriate hydroxy contents, intermolecular hydrogen bonds can be formed between the unreacted amino groups on the surface of the modified flame retardant in the system, further improving the compatibility between the resin system and the modified flame retardant, so that the luminescent heat-resistant flame-retardant coating has excellent flame retardancy, heat resistance and mechanical properties and is suitable for use in fire-fighting equipment.

[0025] (2) The present invention modifies calcium dihydrogen phosphate and magnesium hydroxide with an amino silane coupling agent, then adds hexachlorocyclotriphosphazene for reaction to obtain a modified flame retardant, and then through the combination of two hydroxy acrylic resins and the modified flame retardant, on the one hand, since the modified flame retardant contains phosphazene compounds, it has better thermal stability itself. In addition, due to the formation of intermolecular hydrogen bonds between the unreacted amino groups on the hydroxy acrylic resin and the modified flame retardant, the cross-linking of the hydroxy acrylic resin molecular chains is promoted, thereby improving the heat resistance of the coating film, so that the luminescent heat-resistant flame-retardant coating further improves the heat resistance and water resistance of the coating film on the premise of ensuring the flame retardancy and luminescent properties of the coating film.

[0026] (3) The present invention also provides a preparation method of a luminescent heat-resistant flame-retardant coating, especially by regulating the mass ratios of the inorganic flame retardant, the silane coupling agent and hexachlorocyclotriphosphazene and the mass ratio of europium-dysprosium doped strontium aluminate and soluble aluminum sulfate salt, a specific modified flame retardant and a coated luminescent powder are obtained, so that the coating obtained by applying the modified flame retardant and the coated luminescent powder has excellent flame retardancy and heat resistance. Detailed implementation mode

[0027] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meanings understood by those skilled in the art for the present invention. In case of conflict, the definitions in this specification shall prevail.

[0028] The theories or mechanisms described and disclosed herein, whether correct or incorrect, shall not in any way limit the scope of the present invention, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0029] In this text, when describing the embodiments or examples, it should be understood that it is not used to limit the present invention to these embodiments or examples. On the contrary, all alternatives, improvements, and equivalents of the methods and materials described in the present invention can be covered within the scope defined by the claims.

[0030] In this text, for the sake of concise description, not all possible combinations of the technical features in each embodiment or example are described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered to be within the scope described in this specification.

[0031] The present invention provides a luminescent heat-resistant and flame-retardant coating, which comprises the following raw materials by weight percentage: 30 - 40% of a first hydroxy acrylic resin, 10 - 15% of a second hydroxy acrylic resin, 5 - 10% of an amino resin, 20 - 30% of a modified flame retardant, 2 - 5% of a coated luminescent powder, 5 - 10% of hollow glass microspheres, and the balance of a solvent; wherein, the modified flame retardant is an inorganic flame retardant modified by an amino silane coupling agent and hexachlorocyclotriphosphazene; the coated luminescent powder comprises an inner layer and a coating layer, the inner layer is strontium aluminate doped with europium and dysprosium, and the coating layer is alumina.

[0032] In some embodiments, the mass fraction of hydroxyl groups in the first hydroxy acrylic resin is 2.4 - 3.0%.

[0033] In some embodiments, the mass fraction of hydroxyl groups in the second hydroxy acrylic resin is 1.7 - 2.0%.

[0034] In some embodiments, the inorganic flame retardant is calcium dihydrogen phosphate and magnesium hydroxide with a mass ratio of 2 - 3:1.

[0035] In some embodiments, the amino resin is a methylated high imino melamine resin.

[0036] In some embodiments, the particle size of the hollow glass microspheres is 10 - 100 μm, and the bulk density is 0.10 - 0.16 g / cm 3 .

[0037] In some embodiments, the solvent is selected from one or more of propylene glycol monomethyl ether acetate, xylene, and butyl acetate.

[0038] The present invention also provides a preparation method of the luminescent heat-resistant and flame-retardant coating according to any one of the above, comprising the following steps:

[0039] (1) Preparation of modified flame retardant: Disperse the inorganic flame retardant in an ethanol solution, add an amino silane coupling agent, stir well, and centrifuge to obtain a solid intermediate product. Add the solid intermediate product to a solution containing hexachlorocyclotriphosphazene, and react under a nitrogen atmosphere to obtain the modified flame retardant;

[0040] (2) Preparation of coated luminescent powder: Disperse strontium aluminate doped with europium and dysprosium in an ethanol solution, add a soluble aluminum sulfate salt, adjust the pH with an alkali solution under uniform stirring, and after sufficient reaction, wash, dry, and calcine to obtain the coated luminescent powder;

[0041] (3) Weigh the modified flame retardant, coated luminescent powder, first hydroxy acrylic resin, second hydroxy acrylic resin, amino resin, hollow glass microspheres and solvent in proportion, and stir evenly to obtain the luminescent heat-resistant flame retardant coating.

[0042] In some embodiments, in step (1), the mass ratio of the inorganic flame retardant, silane coupling agent and hexachlorocyclotriphosphazene is 1.5 - 2:1:1 - 1.5.

[0043] In some embodiments, in step (2), the mass ratio of the strontium aluminate doped with europium and dysprosium and the soluble aluminum sulfate salt is 1:2 - 3.

[0044] The present invention also provides an application of the above-mentioned luminescent heat-resistant flame retardant coating or the luminescent heat-resistant flame retardant coating prepared according to the above preparation method in fire-fighting equipment.

[0045] The present invention will be described in detail below through examples. It should be understood that the following examples are only used to further explain and illustrate the content of the present invention by way of example, and are not used to limit the present invention.

[0046] The chemical auxiliaries used in the examples and comparative examples of the present invention are all commercially available, and the specific information is as follows:

[0047] First hydroxy acrylic resin: The mass fraction of hydroxyl is 3.0%, purchased from Shanghai Huayi Fine Chemical Co., Ltd.; Second hydroxy acrylic resin: The mass fraction of hydroxyl is 2.0%, purchased from Shanghai Huayi Fine Chemical Co., Ltd.; Methylated high imino melamine resin, high imino butylated amino resin: purchased from Axalta Coating Systems; Amino silane coupling agent: γ-aminopropyltriethoxysilane, purchased from Shanghai Macklin Biochemical Co., Ltd.; Strontium aluminate doped with europium and dysprosium: purchased from Sigma-Aldrich; Soluble aluminum sulfate salt: purchased from Zibo Guangzheng Aluminum Salt Chemical Co., Ltd.; Hexachlorocyclotriphosphazene, calcium dihydrogen phosphate, magnesium hydroxide, ethanol, DMF, ammonia water, propylene glycol monomethyl ether acetate, butyl acetate: purchased from Aladdin Reagent Co., Ltd.

[0048] Example 1

[0049] A luminescent heat-resistant and flame-retardant coating according to this embodiment, by weight percentage, comprises the following raw materials: 30% of a first hydroxy acrylic resin, 10% of a second hydroxy acrylic resin, 5% of a methylated high imino melamine resin, 30% of a modified flame retardant, 2% of a coated luminescent powder, 5% of hollow glass microspheres, and the balance of propylene glycol monomethyl ether acetate; wherein, the modified flame retardant is calcium dihydrogen phosphate and magnesium hydroxide modified by an amino silane coupling agent and hexachlorocyclotriphosphazene; the coated luminescent powder comprises an inner layer and a coating layer, the inner layer is strontium aluminate doped with europium and dysprosium, and the coating layer is alumina; the mass ratio of the calcium dihydrogen phosphate to the magnesium hydroxide is 3:1.

[0050] The preparation method of the luminescent heat-resistant and flame-retardant coating according to this embodiment comprises the following steps:

[0051] (1) Prepare the modified flame retardant: Disperse 1.5 g of calcium dihydrogen phosphate and 0.5 g of magnesium hydroxide in 50 mL of an ethanol solution, add 1 g of an amino silane coupling agent, stir well at 45 °C for 2 h, then centrifuge to obtain a solid intermediate product. Add the solid intermediate product to 50 mL of a DMF solution containing 1.5 g of hexachlorocyclotriphosphazene, and react fully at 80 °C for 5 h under a nitrogen atmosphere and alkaline conditions. Then centrifuge, wash, and dry to obtain the modified flame retardant;

[0052] (2) Prepare the coated luminescent powder: Disperse 1 g of strontium aluminate doped with europium and dysprosium in 50 mL of an ethanol solution, and drop it into 50 mL of an ethanol solution containing 2.5 g of a soluble aluminum sulfate salt. Adjust the pH to 6 with ammonia water under uniform stirring, react fully at 85 °C for 5 h, wash, dry, and calcine to obtain the coated luminescent powder;

[0053] (3) Weigh the modified flame retardant, coated luminescent powder, first hydroxy acrylic resin, second hydroxy acrylic resin, methylated high imino melamine resin, hollow glass microspheres, and propylene glycol monomethyl ether acetate in proportion, and stir evenly to obtain the luminescent heat-resistant and flame-retardant coating.

[0054] Example 2

[0055] A luminescent heat-resistant and flame-retardant coating according to this embodiment, by weight percentage, comprises the following raw materials: 40% of a first hydroxy acrylic resin, 10% of a second hydroxy acrylic resin, 10% of a methylated high imino melamine resin, 20% of a modified flame retardant, 5% of a coated luminescent powder, 5% of hollow glass microspheres, and the balance of butyl acetate; wherein, the modified flame retardant is calcium dihydrogen phosphate and magnesium hydroxide modified by an amino silane coupling agent and hexachlorocyclotriphosphazene; the coated luminescent powder comprises an inner layer and a coating layer, the inner layer is strontium aluminate doped with europium and dysprosium, and the coating layer is alumina; the mass ratio of the calcium dihydrogen phosphate to the magnesium hydroxide is 2:1.

[0056] The preparation method of the luminescent heat-resistant flame-retardant coating described in this embodiment includes the following steps:

[0057] (1) Prepare a modified flame retardant: Disperse 1 g of calcium dihydrogen phosphate and 0.5 g of magnesium hydroxide in 50 mL of ethanol solution, add 1 g of amino silane coupling agent, and stir well at 50 °C for 2 h. Then, centrifuge to obtain a solid intermediate product. Add the solid intermediate product to 50 mL of DMF solution containing 1 g of hexachlorocyclotriphosphazene. Under a nitrogen atmosphere and alkaline conditions, react fully at 75 °C for 5 h, centrifuge, wash, and dry to obtain the modified flame retardant;

[0058] (2) Prepare a coated luminescent powder: Disperse 1 g of europium-dysprosium-doped strontium aluminate in 50 mL of ethanol solution, and drop it into 50 mL of ethanol solution containing 3 g of soluble aluminum sulfate salt. While stirring evenly, adjust the pH to 5 with ammonia water, and react fully at 80 °C for 6 h. Wash, dry, and calcine to obtain the coated luminescent powder;

[0059] (3) Weigh the modified flame retardant, coated luminescent powder, first hydroxy acrylic resin, second hydroxy acrylic resin, methylated high imino melamine resin, hollow glass microspheres, and butyl acetate in proportion, and stir evenly to obtain the luminescent heat-resistant flame-retardant coating.

[0060] Example 3

[0061] A luminescent heat-resistant flame-retardant coating described in this embodiment, by weight percentage, includes the following raw materials: 35% of the first hydroxy acrylic resin, 15% of the second hydroxy acrylic resin, 10% of the methylated high imino melamine resin, 20% of the modified flame retardant, 3% of the coated luminescent powder, 10% of the hollow glass microspheres, and the balance of propylene glycol monomethyl ether acetate; wherein, the modified flame retardant is calcium dihydrogen phosphate and magnesium hydroxide modified by amino silane coupling agent and hexachlorocyclotriphosphazene; the coated luminescent powder includes an inner layer and a coating layer, the inner layer is europium-dysprosium-doped strontium aluminate, and the coating layer is alumina; the mass ratio of calcium dihydrogen phosphate to magnesium hydroxide is 3:1.

[0062] The preparation method of the luminescent heat-resistant flame-retardant coating described in this embodiment includes the following steps:

[0063] (1) Prepare a modified flame retardant: Disperse 1.5 g of calcium dihydrogen phosphate and 0.5 g of magnesium hydroxide in 50 mL of ethanol solution, add 1 g of amino silane coupling agent, and stir well at 45 °C for 1.5 h. Then, centrifuge to obtain a solid intermediate product. Add the solid intermediate product to 50 mL of DMF solution containing 1.5 g of hexachlorocyclotriphosphazene. Under a nitrogen atmosphere and alkaline conditions, react fully at 80 °C for 6 h, centrifuge, wash, and dry to obtain the modified flame retardant;

[0064] (2) Preparation of coated luminescent powder: 1 g of europium-dysprosium-doped strontium aluminate was dispersed in 50 mL of ethanol solution and dropped into 50 mL of ethanol solution dissolved with 2 g of soluble aluminum sulfate salt. Under uniform stirring, the pH was adjusted to 6 with ammonia water, and the reaction was fully carried out at 85 °C for 5 h. After washing, drying and calcining, the coated luminescent powder was obtained;

[0065] (3) Weigh the modified flame retardant, coated luminescent powder, first hydroxy acrylic resin, second hydroxy acrylic resin, methylated high imino melamine resin, hollow glass microspheres and propylene glycol monomethyl ether acetate in proportion and stir evenly to obtain the luminescent heat-resistant flame retardant coating.

[0066] Comparative Example 1

[0067] The preparation method of the luminescent heat-resistant flame retardant coating in this comparative example is exactly the same as that in Example 1, except that the modified flame retardant is calcium dihydrogen phosphate modified by amino silane coupling agent and hexachlorocyclotriphosphazene, that is, step (1) is: 2 g of calcium dihydrogen phosphate was dispersed in 50 mL of ethanol solution, 1 g of amino silane coupling agent was added, and after stirring at 45 °C for 2 h, the solid intermediate product was obtained by centrifugation. The solid intermediate product was added to 50 mL of DMF solution dissolved with 1.5 g of hexachlorocyclotriphosphazene. Under nitrogen atmosphere and alkaline conditions, the reaction was fully carried out at 80 °C for 5 h, and after centrifugation, washing and drying, the modified flame retardant was obtained.

[0068] Comparative Example 2

[0069] The preparation method of the luminescent heat-resistant flame retardant coating in this comparative example is exactly the same as that in Example 1, except that the luminescent powder is europium-dysprosium-doped strontium aluminate luminescent powder.

[0070] Comparative Example 3

[0071] The preparation method of the luminescent heat-resistant flame retardant coating in this comparative example is exactly the same as that in Example 1, except that the coating only contains 40% of the first hydroxy acrylic resin, that is, the second hydroxy acrylic resin is replaced with the first hydroxy acrylic resin of equal mass.

[0072] Comparative Example 4

[0073] The preparation method of the luminescent heat-resistant flame retardant coating in this comparative example is exactly the same as that in Example 1, except that the hydroxy content of the first hydroxy acrylic resin is 4%.

[0074] Performance Test

[0075] The luminescent heat-resistant flame retardant coatings obtained in Examples 1-3 and Comparative Examples 1-4 were uniformly coated on the surface of the substrate and cured by baking at 200 °C for 10 min to obtain a coating film with a dry film thickness of 10 μm. The performance tests were carried out according to the following methods, and the specific results are shown in Table 1.

[0076] (1)Appearance of the coating film: Visual inspection and touch by hand;

[0077] (2)Adhesion: Tested in accordance with the standard of GB / T9286 - 2021;

[0078] (3)Water resistance: Tested in accordance with the standard of GB / T1733 - 93;

[0079] (4)Scratch resistance: Tested in accordance with the standard of GB / T9279.1 - 2015;

[0080] (5)Limiting oxygen index LOI: The size of the test sample is 120×60×1mm 3 , and the limiting oxygen index of the test sample is tested according to the standard of ASTM D2863 - 77;

[0081] (6)Hardness: Tested in accordance with the standard of GB / T6739 - 2007;

[0082] (7)Luminescence performance: Observe the initial luminescence of the coating film in the dark and the luminescence of the coating film after 2 days of immersion treatment respectively;

[0083] (8)Tensile strength: Conducted in accordance with the standard of GBT23445 - 2009, and the initial tensile strength and the tensile strength after 2 days of immersion treatment are tested respectively;

[0084] (9)Heat - resistant limit temperature: After keeping in a high - temperature furnace for 2 hours, observe the appearance of the coating film and record the limit temperature at which blistering and cracking of the coating film occur;

[0085] (10)Smoke density rating SDR: Conducted in accordance with the standard of GB / T8627 - 1999.

[0086] Table 1 Performance data of Examples 1 - 3 and Comparative Examples 1 - 4

[0087] 。

[0088] As can be seen from Table 1, the luminescent heat-resistant flame-retardant coating described in Examples 1-3 of the present invention has good adhesion, a relatively high limiting oxygen index, a relatively high heat-resistant limit temperature, and a relatively low smoke density grade after film formation. At the same time, the luminescent properties and tensile strength change little before and after immersion in water, indicating that the coating of the present invention has excellent flame-retardant and smoke-suppressing effects, as well as good heat resistance, water resistance and mechanical properties. By comparing Example 1 with Comparative Example 1, it can be seen that the modified flame retardant in Comparative Example 1 is calcium dihydrogen phosphate modified by an amino silane coupling agent and hexachlorocyclotriphosphazene, and the smoke-suppressing effect of the coating film is poor. By comparing Example 1 with Comparative Example 2, it can be seen that the luminescent powder in Comparative Example 2 is not coated and modified, and the luminescence fails after the coating film is treated by immersion in water. By comparing Example 1 with Comparative Example 3, it can be seen that Comparative Example 3 only contains the first hydroxy acrylic resin, and the adhesion, water resistance and heat-resistant limit temperature of the coating film become worse. By comparing Example 1 with Comparative Example 4, it can be seen that the hydroxy group content of the first hydroxy acrylic resin in Comparative Example 4 is on the high side, and the adhesion, water resistance and heat-resistant limit temperature of the coating film become worse.

[0089] Thus, by adding hydroxy acrylic resins and amino resins with different hydroxy group contents in a certain compounding ratio, synergistically modifying the flame retardant and coating the luminescent powder, the luminescent heat-resistant flame-retardant coating of the present invention has excellent flame-retardant and smoke-suppressing effects, as well as good heat resistance, water resistance and mechanical properties, and is suitable for use in fire-fighting equipment.

[0090] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation manners here. Any obvious changes or modifications derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A luminous heat-resistant flame-retardant coating, characterized in that: The invention comprises the following raw materials in weight percentage: 30-40% of a first hydroxy acrylic resin, 10-15% of a second hydroxy acrylic resin, 5-10% of an amino resin, 20-30% of a modified flame retardant, 2-5% of a coated luminescent powder, 5-10% of hollow glass microspheres and the remainder of a solvent; wherein the modified flame retardant is an inorganic flame retardant modified by an aminosilane coupling agent and hexachlorocyclotriphosphazene; the coated luminescent powder comprises an inner layer and a coating layer, wherein the inner layer is europium dysprosium doped strontium aluminate, and the coating layer is aluminum oxide; the mass fraction of hydroxyl groups in the first hydroxy acrylic resin is 2.4-3.0%, and the mass fraction of hydroxyl groups in the second hydroxy acrylic resin is 1.7-2.0%; the inorganic flame retardant is calcium dihydrogen phosphate and magnesium hydroxide in a mass ratio of 2-3:1; The preparation method of the modified flame retardant comprises the following steps: dispersing an inorganic flame retardant in an ethanol solution, adding an aminosilane coupling agent, fully stirring, centrifuging to obtain a solid intermediate product, adding the solid intermediate product to a solution containing hexachlorocyclotriphosphazene, reacting under a nitrogen atmosphere, and obtaining the modified flame retardant.

2. The luminous heat-resistant flame-retardant coating according to claim 1, characterized in that: The amino resin is a methylated high-imino melamine resin.

3. The luminous heat-resistant flame-retardant coating according to claim 1, characterized in that: The particle size of the hollow glass microspheres is 10-100 μm, and the bulk density is 0.10-0.16 g / cm 3 .

4. The luminous heat-resistant flame-retardant coating according to claim 1, characterized in that: The solvent is selected from one or more of propylene glycol monomethyl ether acetate, xylene, and butyl acetate.

5. A method for preparing the luminous heat-resistant flame-retardant coating according to any one of claims 1 to 4, characterized in that: The steps include: (1) Preparing a modified flame retardant: dispersing an inorganic flame retardant in an ethanol solution, adding an aminosilane coupling agent, stirring the mixture sufficiently, and centrifuging the mixture to obtain a solid intermediate product. The solid intermediate product is added to a solution containing hexachlorocyclotriphosphazene, and reacting the mixture under a nitrogen atmosphere to obtain a modified flame retardant. (2) Preparing a coated luminescent powder: dispersing europium-dysprosium-doped strontium aluminate in an ethanol solution, adding a soluble aluminum sulfate salt, adjusting the pH with an alkaline solution under uniform stirring, washing, drying, and calcining after sufficient reaction to obtain the coated luminescent powder; (3) Weigh the modified flame retardant, the coated luminescent powder, the first hydroxy acrylic resin, the second hydroxy acrylic resin, the amino resin, the hollow glass microbeads and the solvent in proportion, stir them evenly, and obtain the luminescent heat-resistant flame retardant coating.

6. The method for preparing the luminous heat-resistant flame-retardant coating according to claim 5, characterized in that: In step (1), the mass ratio of the inorganic flame retardant, the silane coupling agent and the hexachlorocyclotriphosphazene is 1.5-2:1:1-1.

5.

7. The method for preparing the luminous heat-resistant flame-retardant coating according to claim 5, characterized in that: In step (2), the mass ratio of the europium-dysprosium-doped strontium aluminate to the soluble aluminum sulfate salt is 1:2-3.

8. Use of the luminescent heat-resistant flame-retardant coating according to any one of claims 1 to 4 or the luminescent heat-resistant flame-retardant coating prepared by the preparation method according to any one of claims 5 to 7 in fire-fighting equipment.