Flame-retardant artificial board and flame-retardant spraying method and preparation method thereof

Abstract

The invention discloses a flame-retardant artificial board and a flame-retardant spraying method and a preparation method thereof, and belongs to the technical field of flame-retardant artificial board preparation. The preparation method of the flame-retardant artificial board comprises the following steps that firstly, an artificial board base material is treated through sanding and dust removal processes, and the artificial board with the flat surface is obtained; 2, the artificial board is placed in an anti-ultraviolet aging solution, soaked, taken out and dried, and a pretreated artificial board is obtained; and thirdly, the composite liquid flame retardant is sprayed to the surface of the pretreated artificial board, and after drying treatment, the flame-retardant artificial board is obtained. The flame-retardant artificial board prepared by the method has excellent mechanical properties, flame retardance and ultraviolet aging resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of wood-based panel preparation, and particularly relates to a flame-retardant wood-based panel, its flame-retardant spraying method and preparation method. Background Art

[0002] With the acceleration of the urbanization process and the continuous emergence of high-rise buildings, the application of wood and its products in fields such as construction and furniture manufacturing has become increasingly widespread. However, as a combustible material, wood is extremely easy to burn in a fire, posing a serious threat to people's lives and property safety. Therefore, developing flame-retardant wood-based panels has become an important research direction.

[0003] A flame-retardant wood-based panel, also known as a fire-retardant board, is a new type of board made by adding a flame retardant to the board production line through a complex process during the wood-based panel production process. This board not only retains the original excellent physical and mechanical properties of wood, such as light weight, high strength, and easy processing, but also significantly improves its fire resistance. The flame-retardant wood-based panel can effectively delay the spread of fire and reduce the release of toxic smoke in a fire, thus buying precious escape time for people and reducing casualties and property losses caused by the fire.

[0004] Patent CN220947016U discloses a flame-retardant wood-based panel, including a substrate, a first heat-insulating layer and a second heat-insulating layer. A connecting groove is opened at the left end of the substrate, a receiving groove is opened at the upper left end of the substrate, a reinforcing strip is fixed at the outer end of the spring, a first heat-insulating layer is fixed on the front side of the substrate, a second heat-insulating layer is fixed at the rear of the substrate, a magnesium oxychloride flame-retardant layer is arranged outside the second heat-insulating layer, the length dimension of the connecting groove is greater than the length dimension of the connecting strip, the lower surface of the reinforcing strip is flush with the upper surface of the connecting strip, the receiving groove is located on the right side of the connecting groove, connecting blocks are uniformly fixed at the inner end of the magnesium oxychloride flame-retardant layer, and the connecting blocks are connected to the first heat-insulating layer and the second heat-insulating layer in a snap-fit manner. The flame-retardant wood-based panel prepared by this method is convenient for disassembling and assembling the magnesium oxychloride flame-retardant layer and is easy to replace. However, there is still room for improvement in the flame-retardant performance, mechanical properties and anti-ultraviolet aging performance of the flame-retardant wood-based panel prepared by this method. Summary of the Invention

[0005] The purpose of the present invention is to provide a flame-retardant wood-based panel, its flame-retardant spraying method and preparation method, so as to solve the technical problems of poor flame-retardant performance, mechanical properties and anti-ultraviolet aging performance of the flame-retardant wood-based panel in the prior art.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The present invention provides a preparation method of a flame-retardant wood-based panel, including the following steps:

[0008] Step 1: Treat the wood-based panel substrate through sanding and dust removal processes to obtain a wood-based panel with a flat surface;

[0009] Step 2: Immerse the wood-based panel in an anti-ultraviolet aging solution, soak it, take it out, and dry it to obtain a pretreated wood-based panel;

[0010] Step 3: Spray a composite liquid flame retardant on the surface of the pretreated wood-based panel, and after drying treatment, obtain a flame-retardant wood-based panel.

[0011] Preferably, in the above Step 2, the preparation method of the anti-ultraviolet aging solution includes the following steps:

[0012] Q1: Add chrysin, anhydrous potassium carbonate, and acetone into a container, heat and stir under reflux, then gradually add a mixed solution of 1,3-dibromopropane and acetone dropwise using a constant pressure dropping funnel, heat and condense under reflux for reaction. After the reaction is completed, filter, suction filter, recrystallize, and vacuum dry to obtain Compound 1;

[0013] Q2: Add salicylic acid into a container filled with ethanol, slowly drop thionyl chloride under ice bath conditions, and after dropping, heat and condense under reflux for reaction. After the reaction is completed, perform vacuum distillation to obtain Compound 2;

[0014] Q3: Add Compound 2 into a container filled with N,N-dimethylformamide, then add potassium carbonate, stir, add Compound 1 and tetrabutylammonium bromide, heat and stir for reaction. After the reaction is completed, extract, wash the organic layer, dry, perform vacuum distillation, separate and purify to obtain a pale yellow powder. Disperse the obtained pale yellow powder ultrasonically in distilled water, and after ultrasonic stirring, obtain the anti-ultraviolet aging solution.

[0015] In the above process, using chrysin as the raw material, acetone as the solvent, heating under reflux, adding 1,3-dibromopropane in the presence of potassium carbonate, after reflux reaction, obtain Compound 1. Add salicylic acid into ethanol, add thionyl chloride as a catalyst under ice bath conditions, after heating under reflux, obtain Compound 2. Then, using N,N-dimethylformamide as the solvent, add potassium carbonate, stir and add Compound 1, use tetrabutylammonium bromide as a catalyst, heat and stir for reaction to obtain a pale yellow powder. Finally, add the pale yellow powder into distilled water to obtain the anti-ultraviolet aging solution. Among them, the synthesis reaction formula of the pale yellow powder is as follows:

[0016]

[0017] The results of mass spectrometry analysis of Compound 1 were: m / z: 374.02 (100.0%), 376.01 (97.3%), 375.02 (19.8%), 377.02 (19.4%), 376.02 (2.6%), 378.02 (2.6%); the results of mass spectrometry analysis of Compound 2 were: m / z: 166.06 (100.0%), 167.07 (10.0%), 168.07 (1.1%); the results of mass spectrometry analysis of the pale yellow powder were: m / z: 460.15 (100.0%), 461.16 (29.7%), 462.16 (5.7%).

[0018] Preferably, in Q1, the dosage ratio of chrysin, potassium carbonate and 1,3-dibromopropane is (2.52 - 2.58) g : (0.61 - 0.78) g : (3.8 - 6.3) mL, the heating and reflux reaction temperature is 150 - 155 °C, the reaction time is 6 - 8 h, and recrystallization is carried out with 95 vt% ethanol; in Q2, the dosage ratio of salicylic acid, ethanol and thionyl chloride is (1.21 - 1.45) g : (30 - 45) mL : (0.8 - 1.3) mL.

[0019] Preferably, in Q3, the dosage ratio of Compound 2, N,N-dimethylformamide, potassium carbonate, Compound 1 and tetrabutylammonium bromide is (0.8 - 0.87) g : (10 - 15) mL : (0.21 - 0.35) g : (0.29 - 0.42) g : (0.01 - 0.05) g. The stirring time of adding potassium carbonate is 10 - 14 min, the heating and stirring reaction temperature is 60 - 70 °C, the stirring reaction time is 5 - 7 h, extraction is carried out with ethyl acetate, washing is carried out with saturated sodium chloride, drying is carried out with anhydrous sodium sulfate, and the eluent in the separation and purification process is a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:4. The dosage ratio of the pale yellow powder and distilled water is (8 - 12) g : (25 - 45) mL.

[0020] Preferably, in the second step, the soaking time is 12 - 15 h, the drying temperature is 40 - 60 °C, and the drying time is 20 - 24 h.

[0021] Preferably, in the third step, the preparation method of the composite liquid flame retardant includes the following steps:

[0022] S1: Add 1,4-dioxane to a container filled with nitrogen, then add hexachlorocyclotriphosphazene and hydroquinone. After ultrasonic stirring, add potassium carbonate and heat for reaction. After the reaction is completed, cool, wash, vacuum filter, and freeze-dry to obtain product A;

[0023] S2: Under heating, add epichlorohydrin, ethylene glycol, and distilled water into a container equipped with a stirrer, reflux condenser, and thermometer. Then add 4,4'-diaminodiphenylmethane and stir for reaction. Subsequently, add acetone and stir for dissolution reaction. Then add acetone until reflux occurs, cool down, slowly add sodium hydroxide solution for reaction. After the reaction ends, keep warm. Then add toluene, stir, let it stand, take the upper-layer liquid for reduced-pressure treatment, and perform vacuum distillation to obtain product B;

[0024] S3: Mix and stir product A and product B, and filter to obtain a composite liquid flame retardant.

[0025] In the above process, there are six highly reactive chlorine atoms on the phosphorus atom of hexachlorocyclotriphosphazene. The phenolic hydroxyl group of hydroquinone acts as a nucleophile to attack the phosphorus-chlorine bond, undergoing a nucleophilic substitution reaction. The chlorine ion is replaced by a phenoxy group to form a phosphorus-oxygen-phenyl bond, obtaining product A. Then the hydroxyl group of ethylene glycol attacks the epoxy ring of epichlorohydrin, undergoing a ring-opening reaction to form a chlorohydrin intermediate. Then the primary amine of 4,4'-diaminodiphenylmethane attacks the epoxy group of epichlorohydrin to form a secondary amine structure, obtaining product B. Mix and stir product A and product B to obtain a composite liquid flame retardant.

[0026] Preferably, in S1, the dosage ratio of 1,4-dioxane, hexachlorocyclotriphosphazene, hydroquinone, and potassium carbonate is (5 - 10) mL : (0.17 - 0.35) g : (0.165 - 0.34) g : (2.07 - 4.12) g. The ultrasonic stirring time is 5 - 10 min, the heating reaction temperature is 80 - 90 °C, the reaction time is 48 - 52 h. First, wash with deionized water, then wash with tetrahydrofuran, and finally wash with deionized water. The freeze-drying time is 20 - 28 h.

[0027] Preferably, in S2, the heating temperature is 50 - 60 °C. The dosage ratio of epichlorohydrin, ethylene glycol, distilled water, and 4,4'-diaminodiphenylmethane is (5 - 8) mL : (20 - 30) mL : (80 - 120) mL : (1 - 3) g. The stirring reaction time is 3 - 5 h, the stirring dissolution reaction time is 10 - 12 h, cool down to 25 - 28 °C, the heat preservation temperature is 30 - 50 °C, the heat preservation time is 40 - 80 min, and the stirring time is 10 - 20 min. In S3, the dosage ratio of product A and product B is (8 - 10) g : (30 - 50) mL.

[0028] A flame-retardant wood-based panel prepared by the method according to any one of claims 1 - 8.

[0029] The flame-retardant spraying method for flame-retardant wood-based panels, which is applicable to the flame-retardant wood-based panels described in claim 9, includes the following steps: Using a high-pressure airless spraying device to spray a composite liquid flame retardant onto the surface of the wood-based panel, controlling the spraying pressure and spraying volume. The drying process is as follows: First, keep it at 80°C for 2 hours, and then keep it at 140°C for 8 hours.

[0030] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0031] 1. By applying the prepared anti-ultraviolet aging solution and the composite liquid flame retardant to the preparation process of the flame-retardant wood-based panel, the present invention can effectively improve the flame-retardant performance, aging resistance performance, and mechanical properties of the wood-based panel.

[0032] 2. Using chrysin, 1,3-dibromopropane, salicylic acid, ethanol, and tetrabutylammonium bromide as the main raw materials, the present invention prepares an anti-ultraviolet aging solution. The anti-ultraviolet aging solution has the functions of ultraviolet absorption and free radical quenching, effectively preventing the ultraviolet aging performance of the wood-based panel.

[0033] 3. Using 1,4-dioxane, hexachlorocyclotriphosphazene, hydroquinone, epichlorohydrin, ethylene glycol, and 4,4'-diaminodiphenylmethane as the main raw materials, the present invention prepares a composite liquid flame retardant. The nitrogen and phosphorus elements contained in the composite liquid flame retardant can effectively improve the flame-retardant performance of the wood-based panel. At the same time, the cross-linked structure contained can form an interpenetrating network with the wood-based panel, improving the mechanical properties of the wood-based panel. Specific Embodiments

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0035] Example 1: This example discloses a preparation method of an anti-ultraviolet aging solution, including the following steps:

[0036] Q1: Add 2.55 g of chrysin, 0.69 g of anhydrous potassium carbonate, and 150 mL of acetone to a container, heat and stir for reflux, and then gradually add a mixed solution of 5.1 mL of 1,3-dibromopropane and 10 mL of acetone drop by drop using a constant pressure dropping funnel. Heat and condense for reflux reaction at 152°C for 8 hours. After the reaction, filter, suction filter, perform recrystallization with 95 vt% ethanol, and dry in vacuum to obtain Compound 1;

[0037] Q2: Add 1.33 g of salicylic acid into a container filled with 37.5 mL of ethanol. Slowly add 1.05 mL of thionyl chloride under ice bath conditions. After the addition is complete, heat under reflux for reaction. After the reaction is over, perform vacuum distillation to obtain Compound 2;

[0038] Q3: Add 0.83 g of Compound 2 into a container filled with 12.5 mL of N,N-dimethylformamide. Then add 0.28 g of potassium carbonate. After stirring for 12 min, add 0.35 g of Compound 1 and 0.03 g of tetrabutylammonium bromide. Heat and stir the reaction at 60 °C for 6 h. After the reaction is over, perform extraction with ethyl acetate, wash the organic layer with saturated sodium chloride, dry it with anhydrous sodium sulfate, perform vacuum distillation, separate and purify. The eluent is a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:4 to obtain a pale yellow powder. Ultrasonically disperse the obtained 10 g of pale yellow powder in 35 mL of distilled water. After ultrasonic stirring, obtain an anti-ultraviolet aging solution.

[0039] This example discloses a preparation method of a composite liquid flame retardant, including the following steps:

[0040] S1: Add 7.5 mL of 1,4-dioxane into a nitrogen-purged container. Then add 0.26 g of hexachlorocyclotriphosphazene and 0.252 g of hydroquinone. After ultrasonic stirring for 10 min, add 3.08 g of potassium carbonate. Heat and react at 85 °C for 48 h. After the reaction is over, cool. First, wash with deionized water, then wash with tetrahydrofuran, and finally wash with deionized water. Perform vacuum filtration and freeze-dry for 24 h to obtain Product A;

[0041] S2: Under heating at 55 °C, add 6.5 mL of epichlorohydrin, 25 mL of ethylene glycol, and 100 mL of distilled water into a container equipped with a stirrer, reflux condenser, and thermometer. Then add 2 g of 4,4'-diaminodiphenylmethane and stir the reaction for 3 h. Subsequently, add 16 mL of acetone and stir to dissolve and react for 12 h. Then add 50 mL of acetone and dissolve until reflux. Cool to 25 °C and slowly add sodium hydroxide solution for reaction. After the reaction is over, keep warm at 40 °C for 60 min. Then add 50 mL of toluene, stir for 10 min, let it stand, and take the upper layer liquid for vacuum treatment and vacuum distillation to obtain Product B;

[0042] S3: Mix and stir 9 g of Product A and 40 mL of Product B, filter to obtain a composite liquid flame retardant.

[0043] This example discloses a preparation method of a flame-retardant wood-based panel, including the following steps:

[0044] Step 1: Treat the wood-based panel substrate through sanding and dust removal processes to obtain a wood-based panel with a smooth surface;

[0045] Step 2: Place the wood-based panel in the anti-ultraviolet aging solution, soak for 15 h, take it out, and dry at 50 °C for 24 h to obtain a pretreated wood-based panel;

[0046] Step 3: Use a high-pressure airless spraying device to spray the composite liquid flame retardant on the surface of the wood-based panel, control the spraying pressure and spraying amount, and after drying treatment, the drying treatment process is as follows: First, keep warm at 80 °C for 2 h, and then keep warm at 140 °C for 8 h to obtain a flame-retardant wood-based panel.

[0047] Example 2: This example discloses a preparation method of an anti-ultraviolet aging solution, which includes the following steps:

[0048] Q1: Add 2.52 g of chrysin, 0.61 g of anhydrous potassium carbonate, and 150 mL of acetone to a container, heat and stir under reflux, and then gradually add a mixed solution of 3.8 mL of 1,3-dibromopropane and 10 mL of acetone drop by drop using a constant pressure dropping funnel. Heat and condense under reflux at 152 °C for 8 h. After the reaction is completed, filter, suction filter, perform recrystallization with 95 vt% ethanol, and vacuum dry to obtain Compound 1;

[0049] Q2: Add 1.21 g of salicylic acid to a container containing 30 mL of ethanol, slowly add 0.8 mL of thionyl chloride under ice bath conditions, and then heat and condense under reflux after dropping. After the reaction is completed, perform vacuum distillation to obtain Compound 2;

[0050] Q3: Add 0.8 g of Compound 2 to a container containing 10 mL of N,N-dimethylformamide, then add 0.21 g of potassium carbonate, stir for 12 min, add 0.29 g of Compound 1 and 0.01 g of tetrabutylammonium bromide, heat and stir at 60 °C for 6 h. After the reaction is completed, extract with ethyl acetate, wash the organic layer with saturated sodium chloride, dry with anhydrous sodium sulfate, perform vacuum distillation, separate and purify, and the eluent is a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:4 to obtain a pale yellow powder. Ultrasonically disperse the obtained 8 g of pale yellow powder in 25 mL of distilled water, and after ultrasonic stirring, obtain the anti-ultraviolet aging solution.

[0051] This example discloses a preparation method of a composite liquid flame retardant, which includes the following steps:

[0052] S1: Add 7 mL of 1,4-dioxane to a container filled with nitrogen, then add 0.17 g of hexachlorocyclotriphosphazene and 0.165 g of hydroquinone, ultrasonically stir for 10 min, add 2.07 g of potassium carbonate, heat and react at 85 °C for 48 h. After the reaction is completed, cool, first wash with deionized water, then wash with tetrahydrofuran, and finally wash with deionized water, perform vacuum filtration, and freeze-dry for 24 h to obtain Product A;

[0053] S2: Under heating at 55 °C, add 5 mL of epichlorohydrin, 20 mL of ethylene glycol, and 80 mL of distilled water into a container equipped with a stirrer, a reflux condenser, and a thermometer. Then add 1 g of 4,4'-diaminodiphenylmethane and stir for 3 h. Subsequently, add 16 mL of acetone and stir to dissolve and react for 12 h. Then add 50 mL of acetone to dissolve until refluxing, cool to 25 °C, slowly add sodium hydroxide solution for reaction. After the reaction ends, keep warm at 40 °C for 60 min. Then add 50 mL of toluene, stir for 10 min, let it stand, take the upper layer liquid for reduced pressure treatment, and perform vacuum distillation to obtain product B;

[0054] S3: Mix and stir 8 g of product A and 30 mL of product B, filter to obtain the composite liquid flame retardant.

[0055] This example discloses a preparation method of a flame-retardant wood-based panel, including the following steps:

[0056] Step 1: Treat the wood-based panel substrate through sanding and dust removal processes to obtain a wood-based panel with a flat surface;

[0057] Step 2: Immerse the wood-based panel in the anti-ultraviolet aging solution for 15 h, take it out, and dry at 50 °C for 24 h to obtain the pretreated wood-based panel;

[0058] Step 3: Use a high-pressure airless spraying device to spray the composite liquid flame retardant on the surface of the wood-based panel, control the spraying pressure and spraying amount. After drying treatment, the drying process is as follows: First, keep warm at 80 °C for 2 h, and then keep warm at 140 °C for 8 h to obtain the flame-retardant wood-based panel.

[0059] Example 3: This example discloses a preparation method of an anti-ultraviolet aging solution, including the following steps:

[0060] Q1: Add 2.58 g of chrysin, 0.78 g of anhydrous potassium carbonate, and 150 mL of acetone into a container, heat and stir for reflux, and then gradually add a mixed solution of 6.3 mL of 1,3-dibromopropane and 10 mL of acetone drop by drop using a constant pressure dropping funnel. Heat and condense for reflux reaction at 152 °C for 8 h. After the reaction ends, filter, perform suction filtration, recrystallize with 95 vt% ethanol, and dry in vacuum to obtain compound 1;

[0061] Q2: Add 1.45 g of salicylic acid into a container containing 45 mL of ethanol, slowly drop 1.3 mL of thionyl chloride under ice bath conditions. After dropping, heat and condense for reflux reaction. After the reaction ends, perform reduced pressure distillation to obtain compound 2;

[0062] Q3: Add 0.87 g of Compound 2 into a container containing 15 mL of N,N-dimethylformamide, then add 0.35 g of potassium carbonate. After stirring for 12 min, add 0.42 g of Compound 1 and 0.05 g of tetrabutylammonium bromide, and heat and stir the reaction at 60 °C for 6 h. After the reaction is completed, extract with ethyl acetate, wash the organic layer with saturated sodium chloride, dry with anhydrous sodium sulfate, and perform vacuum distillation for separation and purification. The eluent is a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:4 to obtain a pale yellow powder. Ultrasonically disperse the obtained 12 g of pale yellow powder in 45 mL of distilled water, and after ultrasonic stirring, obtain an anti-ultraviolet aging solution.

[0063] This example discloses a preparation method of a composite liquid flame retardant, including the following steps:

[0064] S1: Add 10 mL of 1,4-dioxane into a container filled with nitrogen, then add 0.35 g of hexachlorocyclotriphosphazene and 0.34 g of hydroquinone. After ultrasonic stirring for 10 min, add 4.12 g of potassium carbonate, and heat and react at 85 °C for 48 h. After the reaction is completed, cool it. First, wash it with deionized water, then wash it with tetrahydrofuran, and finally wash it with deionized water. Perform vacuum filtration and freeze-dry for 24 h to obtain Product A;

[0065] S2: Under heating at 55 °C, add 8 mL of epichlorohydrin, 30 mL of ethylene glycol, and 120 mL of distilled water into a container equipped with a stirrer, reflux condenser, and thermometer, then add 3 g of 4,4'-diaminodiphenylmethane and stir the reaction for 3 h. Subsequently, add 16 mL of acetone and stir to dissolve and react for 12 h. Then add 50 mL of acetone to dissolve until reflux, cool to 25 °C, slowly add sodium hydroxide solution for reaction. After the reaction is completed, keep it at 40 °C for 60 min. Then add 50 mL of toluene, stir for 10 min, let it stand, and take the upper layer liquid for vacuum treatment and vacuum distillation to obtain Product B;

[0066] S3: Mix and stir 10 g of Product A and 50 mL of Product B, and filter to obtain the composite liquid flame retardant.

[0067] This example discloses a preparation method of a flame-retardant wood-based panel, including the following steps:

[0068] Step 1: Treat the wood-based panel substrate through sanding and dust removal processes to obtain a wood-based panel with a flat surface;

[0069] Step 2: Immerse the wood-based panel in the anti-ultraviolet aging solution for 15 h, take it out, and dry it at 50 °C for 24 h to obtain a pretreated wood-based panel;

[0070] Step 3: Use a high-pressure airless spraying device to spray the composite liquid flame retardant on the surface of the artificial board, control the spraying pressure and spraying volume, and after drying treatment, the drying treatment process is as follows: First, keep warm at 80 °C for 2 h, and then keep warm at 140 °C for 8 h to obtain the flame-retardant artificial board.

[0071] Example 4: This example discloses a preparation method of an anti-ultraviolet aging solution, including the following steps:

[0072] Q1: Add 2.53 g of chrysin, 0.65 g of anhydrous potassium carbonate, and 150 mL of acetone to a container, heat and stir under reflux, and then gradually add a mixed solution of 4.2 mL of 1,3-dibromopropane and 10 mL of acetone dropwise using a constant pressure dropping funnel. Heat and condense under reflux at 152 °C for 8 h. After the reaction is completed, filter, filter by suction, perform recrystallization with 95 vt% ethanol, and dry under vacuum to obtain Compound 1;

[0073] Q2: Add 1.27 g of salicylic acid to a container containing 32 mL of ethanol, slowly add 0.9 mL of thionyl chloride under ice bath conditions, and then heat and condense under reflux after dropping. After the reaction is completed, perform vacuum distillation to obtain Compound 2;

[0074] Q3: Add 0.81 g of Compound 2 to a container containing 11 mL of N,N-dimethylformamide, then add 0.23 g of potassium carbonate, stir for 12 min, add 0.32 g of Compound 1 and 0.02 g of tetrabutylammonium bromide, heat and stir at 60 °C for 6 h. After the reaction is completed, extract with ethyl acetate, wash the organic layer with saturated sodium chloride, dry with anhydrous sodium sulfate, perform vacuum distillation, separate and purify, and the eluent is a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:4 to obtain a pale yellow powder. Ultrasonically disperse the obtained 9 g of pale yellow powder in 30 mL of distilled water, and after ultrasonic stirring, obtain the anti-ultraviolet aging solution.

[0075] This example discloses a preparation method of a composite liquid flame retardant, including the following steps:

[0076] S1: Add 6 mL of 1,4-dioxane to a nitrogen-purged container, then add 0.21 g of hexachlorocyclotriphosphazene and 0.211 g of hydroquinone, ultrasonically stir for 10 min, add 2.51 g of potassium carbonate, heat and react at 85 °C for 48 h. After the reaction is completed, cool, first wash with deionized water, then wash with tetrahydrofuran, and finally wash with deionized water, perform vacuum filtration, and freeze-dry for 24 h to obtain Product A;

[0077] S2: Under heating at 55 °C, add 6 mL of epichlorohydrin, 22 mL of ethylene glycol, and 90 mL of distilled water into a container equipped with a stirrer, a reflux condenser, and a thermometer. Then add 1.5 g of 4,4'-diaminodiphenylmethane and stir for 3 h. Subsequently, add 16 mL of acetone, stir to dissolve, and react for 12 h. Then add 50 mL of acetone, dissolve until refluxing, cool to 25 °C, slowly add sodium hydroxide solution for reaction. After the reaction ends, keep warm at 40 °C for 60 min. Then add 50 mL of toluene, stir for 10 min, let it stand, take the upper layer liquid for reduced pressure treatment, and perform vacuum distillation under reduced pressure to obtain product B;

[0078] S3: Mix and stir 8.5 g of product A and 35 mL of product B, filter to obtain the composite liquid flame retardant.

[0079] This example discloses a preparation method of a flame-retardant wood-based panel, including the following steps:

[0080] Step 1: Treat the wood-based panel substrate through sanding and dust removal processes to obtain a wood-based panel with a flat surface;

[0081] Step 2: Immerse the wood-based panel in the anti-ultraviolet aging solution for 15 h, take it out, and dry at 50 °C for 24 h to obtain the pretreated wood-based panel;

[0082] Step 3: Spray the composite liquid flame retardant on the surface of the wood-based panel using a high-pressure airless spraying device, control the spraying pressure and spraying amount. After drying treatment, the drying process is as follows: First, keep warm at 80 °C for 2 h, and then keep warm at 140 °C for 8 h to obtain the flame-retardant wood-based panel.

[0083] Example 5: This example discloses a preparation method of an anti-ultraviolet aging solution, including the following steps:

[0084] Q1: Add 2.57 g of chrysin, 0.72 g of anhydrous potassium carbonate, and 150 mL of acetone into a container, heat and stir under reflux, and then gradually add a mixed solution of 5.8 mL of 1,3-dibromopropane and 10 mL of acetone drop by drop using a constant pressure dropping funnel. Heat and condense under reflux at 152 °C for 8 h. After the reaction ends, filter, perform suction filtration, recrystallize with 95 vt% ethanol, and dry under vacuum to obtain compound 1;

[0085] Q2: Add 1.38 g of salicylic acid into a container containing 43 mL of ethanol, slowly drop 1.2 mL of thionyl chloride under ice bath conditions. After dropping, heat and condense under reflux for reaction. After the reaction ends, perform distillation under reduced pressure to obtain compound 2;

[0086] Q3: Add 0.86 g of Compound 2 into a container containing 14 mL of N,N-dimethylformamide, then add 0.31 g of potassium carbonate. After stirring for 12 min, add 0.39 g of Compound 1 and 0.04 g of tetrabutylammonium bromide, and heat and stir the reaction at 60 °C for 6 h. After the reaction is completed, extract with ethyl acetate, wash the organic layer with saturated sodium chloride, dry with anhydrous sodium sulfate, and perform vacuum distillation for separation and purification. The eluent is a mixed solution of ethyl acetate and petroleum ether with a volume ratio of 1:4 to obtain a pale yellow powder. Ultrasonically disperse the obtained 11 g of pale yellow powder in 40 mL of distilled water, and after ultrasonic stirring, obtain an anti-ultraviolet aging solution.

[0087] This example discloses a preparation method of a composite liquid flame retardant, including the following steps:

[0088] S1: Add 9 mL of 1,4-dioxane into a container filled with nitrogen, then add 0.31 g of hexachlorocyclotriphosphazene and 0.303 g of hydroquinone. After ultrasonic stirring for 10 min, add 3.58 g of potassium carbonate, and heat and react at 85 °C for 48 h. After the reaction is completed, cool, first wash with deionized water, then wash with tetrahydrofuran, and finally wash with deionized water, perform vacuum filtration, and freeze-dry for 24 h to obtain Product A;

[0089] S2: Under heating at 55 °C, add 7 mL of epichlorohydrin, 28 mL of ethylene glycol, and 110 mL of distilled water into a container equipped with a stirrer, a reflux condenser, and a thermometer, then add 2.5 g of 4,4'-diaminodiphenylmethane and stir the reaction for 3 h. Subsequently, add 16 mL of acetone and stir to dissolve and react for 12 h. Then add 50 mL of acetone and dissolve until reflux, cool to 25 °C, slowly add sodium hydroxide solution for reaction. After the reaction is completed, keep warm at 40 °C for 60 min, then add 50 mL of toluene, stir for 10 min, let it stand, and take the upper layer liquid for vacuum treatment and vacuum distillation to obtain Product B;

[0090] S3: Mix and stir 9.5 g of Product A and 45 mL of Product B, filter to obtain a composite liquid flame retardant.

[0091] This example discloses a preparation method of a flame-retardant wood-based panel, including the following steps:

[0092] Step 1: Treat the wood-based panel substrate through sanding and dust removal processes to obtain a wood-based panel with a flat surface;

[0093] Step 2: Immerse the wood-based panel in the anti-ultraviolet aging solution for 15 h, take it out, and dry at 50 °C for 24 h to obtain a pretreated wood-based panel;

[0094] Step 3: Use a high-pressure airless spraying device to spray the composite liquid flame retardant on the surface of the artificial board, control the spraying pressure and spraying amount, and after drying treatment, the drying treatment process is as follows: First, keep it warm at 80°C for 2 hours, and then keep it warm at 140°C for 8 hours to obtain the flame-retardant artificial board.

[0095] Comparative Example 1: Compared with Example 1, in the process of preparing the flame-retardant artificial board in Comparative Example 1, the anti-ultraviolet aging solution is not soaked, and other conditions remain unchanged.

[0096] Comparative Example 2: Compared with Example 1, in the process of preparing the flame-retardant artificial board in Comparative Example 2, the composite liquid flame retardant is not sprayed, and other conditions remain unchanged.

[0097] Experimental Example: Perform performance tests on the flame-retardant artificial boards prepared in Examples 1-5 and Comparative Examples 1-2. Use GB8624-2012 to test the combustion performance of the samples, test the oxygen index of the samples according to GB / T 2406.2-2009, test the mechanical properties of the samples according to GB / T 31264-2014, and test the ultraviolet aging performance of the samples according to GB / T 14522-2008. The test results are shown in Table 1:

[0098] Table 1

[0099]

[0100]

[0101] It can be seen from the test results in Table 1 that the flame-retardant artificial boards prepared in Examples 1-5 of the present invention have excellent flame-retardant performance, mechanical properties and anti-ultraviolet aging performance. By comparing Comparative Example 1 with Examples 1-5, it can be seen that soaking the anti-ultraviolet aging solution can effectively improve the mechanical properties and anti-ultraviolet aging performance of the flame-retardant artificial board; by comparing Comparative Example 2 with Examples 1-5, it can be seen that spraying the composite liquid flame retardant can effectively improve the flame-retardant performance of the flame-retardant artificial board.

[0102] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

[0103] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only the specific embodiments. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A method for preparing a flame retardant artificial board, characterized in that: The following steps are involved: Step 1: Treat the artificial board substrate through sanding and dust removal processes to obtain an artificial board with a smooth surface; Step 2: placing the artificial board in an anti-ultraviolet aging solution, soaking, taking out, and drying to obtain a pretreated artificial board; Step 3: Spray the composite liquid flame retardant on the surface of the pretreated artificial board, and obtain the flame retardant artificial board after drying.

2. The method for preparing a flame retardant artificial board according to claim 1, characterized in that: In the step 2, the method for preparing the anti-ultraviolet aging solution comprises the following steps: Q1: Chrysin, anhydrous potassium carbonate and acetone were added to a container, heated and stirred to reflux, and then a mixed solution of 1,3-dibromopropane and acetone was added dropwise using a constant pressure dropping funnel, and heated to condense and reflux for reaction. After the reaction was completed, the mixture was filtered, suction filtered, recrystallized, and vacuum dried to obtain compound 1; Q2: Add salicylic acid to a container containing ethanol, slowly drop thionyl chloride under ice bath conditions, heat and condense to reflux for reaction after the addition is complete, and distill under reduced pressure to obtain compound 2; Q3: Add compound 2 to a container filled with N,N-dimethylformamide, then add potassium carbonate, and after stirring, add compound 1 and tetrabutylammonium bromide, heat and stir to react. After the reaction is completed, extract, wash the organic layer, dry, distill under reduced pressure, separate and purify to obtain a light yellow powder. Ultrasonic disperse the obtained light yellow powder in distilled water, and after ultrasonic stirring, obtain an anti-UV aging solution.

3. The method for preparing a flame retardant artificial board according to claim 2, characterized in that: In the Q1, the dosage ratio of chrysin, anhydrous potassium carbonate and 1,3-dibromopropane is (2.52-2.58) g: (0.61-0.78) g: (3.8-6.3) mL, the heating condensation reflux reaction temperature is 150-155° C., the reaction time is 6-8 h, and recrystallization is carried out using 95vt% ethanol; in the Q2, the dosage ratio of salicylic acid, ethanol and thionyl chloride is (1.21-1.45) g: (30-45) mL: (0.8-1.3) mL.

4. The method for preparing a flame retardant artificial board according to claim 2, characterized in that: In Q3, the dosage ratio of compound 2, N,N-dimethylformamide, potassium carbonate, compound 1 and tetrabutylammonium bromide is (0.8-0.87) g: (10-15) mL: (0.21-0.35) g: (0.29-0.42) g: (0.01-0.05) g, the stirring time after adding potassium carbonate is 10-14 min, the heating and stirring reaction temperature is 60-70°C, the stirring reaction time is 5-7 h, extraction is carried out with ethyl acetate, washing is carried out with saturated sodium chloride, and drying is carried out with anhydrous sodium sulfate. The eluent in the separation and purification process is: a mixed solution of ethyl acetate and petroleum ether in a volume ratio of 1:4, and the dosage ratio of light yellow powder and distilled water is (8-12) g: (25-45) mL.

5. The method for preparing a flame retardant artificial board according to claim 1, characterized in that: In the step 2, the soaking time is 12-15 hours, the drying temperature is 40-60° C., and the drying time is 20-24 hours.

6. The method for preparing a flame retardant artificial board according to claim 1, characterized in that: In the step 3, the preparation method of the composite liquid flame retardant comprises the following steps: S1: 1,4-dioxane is added to a container filled with nitrogen, and then hexachlorotriphosphazene and hydroquinone are added. After ultrasonic stirring, potassium carbonate is added, and the mixture is heated for reaction. After the reaction is completed, the mixture is cooled, washed, vacuum filtered, and freeze-dried to obtain product A. S2: under heating, epichlorohydrin, ethylene glycol and distilled water are added to a container equipped with a stirrer, a reflux condenser and a thermometer, and then 4,4'-diaminodiphenylmethane is added to stir and react, acetone is added to stir and dissolve to react, then acetone is added to dissolve until reflux, cooled, and sodium hydroxide solution is slowly added to react. After the reaction is completed, the temperature is kept, and then toluene is added, stirred, and allowed to stand, and the upper layer of liquid is taken for decompression treatment, and vacuum decompression distillation is performed to obtain product B; S3: Mix and stir the product A and the product B, and filter them to obtain a composite liquid flame retardant.

7. The method for preparing a flame retardant artificial board according to claim 6, characterized in that: In the S1, the dosage ratio of 1,4-dioxane, hexachlorotriphosphazene, hydroquinone and potassium carbonate is (5-10) mL: (0.17-0.35) g: (0.165-0.34) g: (2.07-4.12) g, the ultrasonic stirring time is 5-10 min, the heating reaction temperature is 80-90° C., the reaction time is 48-52 h, the product is first washed with deionized water, then washed with tetrahydrofuran, and finally washed with deionized water, and the freeze-drying time is 20-28 h.

8. The method for preparing a flame retardant artificial board according to claim 6, characterized in that: In S2, the heating temperature is 50-60°C, the dosage ratio of epichlorohydrin, ethylene glycol, distilled water and 4,4'-diaminodiphenylmethane is (5-8) mL: (20-30) mL: (80-120) mL: (1-3) g, the stirring reaction time is 3-5 h, the stirring and dissolving reaction time is 10-12 h, cooled to 25-28°C, the insulation temperature is 30-50°C, the insulation time is 40-80 min, and the stirring time is 10-20 min; in S3, the dosage ratio of product A and product B is (8-10) g: (30-50) mL.

9. A flame retardant artificial board prepared by the method according to any one of claims 1 to 8.

10. A flame retardant spraying method for flame retardant artificial board, applicable to the flame retardant artificial board according to claim 9, characterized in that: The following steps are involved: The composite liquid flame retardant was sprayed on the surface of the artificial board using high-pressure airless spraying equipment, and the spraying pressure and spraying amount were controlled. The drying process was: first, keeping warm at 80°C for 2h, and then keeping warm at 140°C for 8h.

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