Layered double-metal hydroxide reinforced silica gel foam extinguishing agent and preparation method thereof

Abstract

The invention discloses a preparation method of a layered double-metal hydroxide reinforced silica gel foam extinguishing agent, and belongs to the technical field of solid fire prevention and control. The layered double-metal hydroxide reinforced silica gel foam extinguishing agent is prepared by blending silicate, fatty alcohol polyoxyethylene ether sodium sulfate, hydroxybutyl methyl cellulose, phosphoric acid and phosphorylated layered double-metal hydroxide. The preparation method of the layered double-metal hydroxide reinforced silica gel foam extinguishing agent is simple, convenient, low in cost, clean and environmentally friendly, and the prepared foam extinguishing agent has the fluidity and oxygen cooling and diluting capacity of a water-based foam extinguishing agent and also has the excellent thermal stability, water-retaining property and covering and blocking capacity of hydrocolloid; the staying time on the solid surface is prolonged, the water consumption is reduced, and the fire extinguishing agent has good oxygen-isolating, cooling and physical blocking effects and is suitable for extinguishing A-type solid fire disasters.

Description

Technical Field

[0001] The invention relates to the technical field of Class A solid fire prevention and control, and in particular to a method for preparing a layered double metal hydroxide reinforced silica gel foam fire extinguishing agent. Background Art

[0002] Fire is a catastrophic combustion phenomenon that spreads out of control, usually including forest, building, oil and other fires. Generally speaking, the combustibles in fires are divided into combustible solids, combustible liquids, and combustible gases, and the combustion of solid fuels occupies a dominant position in various types of fires. The fire extinguishing principles of Class A solid fires are mainly cooling, covering, suffocation, and chemical inhibition. The key to achieving efficient fire extinguishing and anti-reignition lies in the selection of suitable fire extinguishing media.

[0003] Aqueous gel foam fire extinguishing agents not only have the fluidity, cooling and oxygen dilution capabilities of aqueous foam fire extinguishing agents, but also have the excellent thermal stability, water retention, covering and barrier capabilities of hydrocolloids, prolonging their residence time on solid surfaces, reducing water consumption, and having good oxygen isolation and cooling and physical barrier effects. However, in extreme combustion environments, the fire extinguishing and barrier capabilities of a single aqueous gel foam fire extinguishing agent are still relatively limited. Layered double hydroxides, as an emerging nano flame retardant filler, have the characteristics of unique lamellar structure, ultra-high specific surface area, and adjustable component structure. They can significantly improve the fire extinguishing efficiency and fire barrier capabilities of silicone gel foam materials with a relatively low addition amount. Therefore, it is very necessary to involve a method for preparing a layered double hydroxide reinforced silicone gel foam fire extinguishing agent for Class A solid fires. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a layered double metal hydroxide reinforced silica gel foam fire extinguishing agent to solve the problem mentioned in the above background technology that the fire extinguishing efficiency and fire barrier capacity of water-based fire extinguishing agents currently used for Class A solid fires are relatively limited.

[0005] The layered double hydroxide enhanced silicone gel foam fire extinguishing agent is obtained by blending silicate, sodium sulfate of fatty alcohol polyoxyethylene ether, hydroxybutyl methylcellulose, phosphoric acid, and phosphorylated layered double hydroxide. On the one hand, the layered double hydroxide enhanced silicone gel foam fire extinguishing agent has a certain fluidity at room temperature, can be applied remotely through pressurized equipment, has the fluidity, cooling and oxygen dilution capabilities of water-based foam fire extinguishing agents, and the excellent thermal stability, water retention, covering and barrier capabilities of hydrogel fire extinguishing agents, prolongs its residence time on solid surfaces, and has good oxygen isolation, cooling and physical barrier effects; on the other hand, the introduced phosphorylated layered double hydroxide can synergistically improve the fire extinguishing efficiency and fire barrier capabilities of the silicone gel foam fire extinguishing agent.

[0006] The present invention provides a method for preparing a layered double metal hydroxide reinforced silica gel foam fire extinguishing agent, which is characterized by comprising the following steps, wherein the parts of the materials used are parts by weight unless otherwise specified:

[0007] (1) Preparation of phosphorylated layered double metal hydroxide: 1-200 parts of divalent metal nitrate, 1-100 parts of aluminum nitrate, and 10-1000 parts of water are mixed, and stirred at room temperature for 1 hour to obtain a metal salt mixed solution; 1-100 parts of sodium carbonate and 10-1000 parts of water are mixed evenly, and stirred at a temperature of 40-80°C, with nitrogen protection, and then the metal salt mixed solution and 5-150 parts of organic phosphate are slowly added dropwise, and a 2 mol / L sodium hydroxide solution is added dropwise to maintain the pH value at 8.5; after the addition is completed, the mixture is transferred to a hydrothermal autoclave, kept at 60-90°C for 12-36 hours, and after high-speed centrifugation, deionized water washing, drying, and grinding, the phosphorylated layered double metal hydroxide is obtained and set aside;

[0008] (2) mixing 1 to 100 parts of sodium fatty alcohol polyoxyethylene ether sulfate and 10 to 1000 parts of water in a reaction kettle, stirring at 40° C. for 0.5 to 2 hours to obtain an aqueous solution of sodium fatty alcohol polyoxyethylene ether sulfate for standby use; mixing 1 to 100 parts of hydroxybutyl methylcellulose and 100 to 1000 parts of water in a reaction kettle, stirring at room temperature for 12 to 24 hours to obtain an aqueous solution of hydroxybutyl methylcellulose for standby use;

[0009] (3) 20 to 2000 parts of silicate, 6 to 600 parts of fatty alcohol polyoxyethylene ether sodium sulfate aqueous solution, 6 to 600 parts of hydroxybutyl methylcellulose aqueous solution and 20 to 4000 parts of water are mixed, and stirred at room temperature for 1 hour; then 0.5 to 500 parts of phosphorylated layered double metal hydroxide are added, and stirred at room temperature for 30 minutes; finally, 2 to 200 parts of phosphoric acid are added, and stirred at room temperature for 0.5 to 5 minutes to obtain a layered double metal hydroxide reinforced silicone gel foam fire extinguishing agent.

[0010] The method for preparing the layered double metal hydroxide reinforced silica gel foam fire extinguishing agent is characterized in that the divalent metal nitrate is one of magnesium nitrate, zinc nitrate, cobalt nitrate and copper nitrate.

[0011] The method for preparing the layered double metal hydroxide enhanced silica gel foam fire extinguishing agent is characterized in that the organic phosphate ester is one or more of triethyl diphosphate, dodecyl phosphate, naphthol phosphate, and 3-aminopropyl monophosphate.

[0012] The method for preparing the layered double metal hydroxide reinforced silica gel foam fire extinguishing agent is characterized in that the silicate is one or more of potassium silicate and tetramethylammonium silicate.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The layered double metal hydroxide-enhanced silicone gel foam fire extinguishing agent prepared by the present invention not only has the fluidity, cooling and oxygen dilution capabilities of water-based foam fire extinguishing agents, but also has the excellent thermal stability, water retention, covering and barrier capabilities of hydrocolloids, prolongs its residence time on the solid surface, reduces water consumption, has good oxygen isolation and cooling and physical barrier effects, and is suitable for Class A solid fire fighting.

[0015] (2) Based on the principle of nano-synergistic flame retardancy, the introduced phosphated layered double hydroxide can synergistically improve the fire extinguishing efficiency and fire barrier capacity of silicone gel foam fire extinguishing agent.

[0016] (3) The preparation method used in the present invention is simple, low-cost, clean and environmentally friendly. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1

[0019] A method for preparing a layered double metal hydroxide reinforced silica gel foam fire extinguishing agent according to a preferred embodiment of the present invention, in this embodiment, 60 parts of magnesium nitrate, 40 parts of aluminum nitrate, and 400 parts of water are mixed, stirred at room temperature for 1 hour to obtain a magnesium nitrate-aluminum nitrate mixed solution, 50 parts of sodium carbonate and 500 parts of water are mixed evenly, stirred at a temperature of 75°C, nitrogen protection, and then the magnesium nitrate-aluminum nitrate mixed solution and 40 parts of triethyl diphosphate are slowly added dropwise, and a sodium hydroxide solution with a concentration of 2 mol / L is added dropwise to maintain the pH value at 8.5. After the addition is completed, the mixture is transferred to a hydrothermal kettle and kept at 75°C for 24 hours. After high-speed centrifugation, deionized water washing, drying, and grinding, a phosphated magnesium aluminum layered double metal hydroxide is obtained for standby use;

[0020] Mix 50 parts of sodium fatty alcohol polyoxyethylene ether sulfate and 200 parts of water in a reaction kettle, stir at 40°C for 1 hour to obtain a sodium fatty alcohol polyoxyethylene ether sulfate aqueous solution for standby use; mix 20 parts of hydroxybutyl methylcellulose and 1000 parts of water in a reaction kettle, stir at room temperature for 16 hours to obtain a hydroxybutyl methylcellulose aqueous solution for standby use;

[0021] 200 parts of tetramethylammonium silicate, 100 parts of sodium sulfate aqueous solution of fatty alcohol polyoxyethylene ether, 200 parts of hydroxybutyl methylcellulose aqueous solution and 470 parts of water were mixed and stirred at room temperature for 1 hour, followed by adding 10 parts of phosphated magnesium aluminum layered double metal hydroxide and stirring at room temperature for 30 minutes, and finally adding 20 parts of phosphoric acid and stirring at room temperature for 3 minutes to obtain a layered double metal hydroxide enhanced silicone gel foam fire extinguishing agent. Its gel time, viscosity, pH value, fire extinguishing time and back temperature ≤ 90°C time are shown in Table 1.

[0022] Example 2

[0023] A method for preparing a layered double metal hydroxide reinforced silicone gel foam fire extinguishing agent according to a preferred embodiment of the present invention, in this embodiment, 60 parts of zinc nitrate, 40 parts of aluminum nitrate, and 400 parts of water are mixed, stirred at room temperature for 1 hour to obtain a zinc nitrate-aluminum nitrate mixed solution, 50 parts of sodium carbonate and 500 parts of water are mixed evenly, stirred at a temperature of 75°C, nitrogen protection, then the zinc nitrate-aluminum nitrate mixed solution and 40 parts of triethyl diphosphate are slowly added dropwise, and a sodium hydroxide solution with a concentration of 2 mol / L is added dropwise to maintain the pH value at 8.5. After the addition is completed, the mixture is transferred to a hydrothermal kettle and kept at 75°C for 24 hours. After high-speed centrifugation, deionized water washing, drying, and grinding, a phosphated zinc aluminum layered double metal hydroxide is obtained for standby use;

[0024] Mix 50 parts of sodium fatty alcohol polyoxyethylene ether sulfate and 200 parts of water in a reaction kettle, stir at 40°C for 1 hour to obtain a sodium fatty alcohol polyoxyethylene ether sulfate aqueous solution for standby use; mix 20 parts of hydroxybutyl methylcellulose and 1000 parts of water in a reaction kettle, stir at room temperature for 16 hours to obtain a hydroxybutyl methylcellulose aqueous solution for standby use;

[0025] 200 parts of tetramethylammonium silicate, 150 parts of sodium sulfate aqueous solution of fatty alcohol polyoxyethylene ether, 150 parts of hydroxybutyl methylcellulose aqueous solution and 440 parts of water were mixed and stirred at room temperature for 1 hour, followed by adding 30 parts of phosphated zinc aluminum layered double metal hydroxide and stirring at room temperature for 30 minutes, and finally adding 30 parts of phosphoric acid and stirring at room temperature for 3 minutes to obtain a layered double metal hydroxide enhanced silicone gel foam fire extinguishing agent. Its gel time, viscosity, pH value, fire extinguishing time and back temperature ≤ 90°C time are shown in Table 1.

[0026] Example 3

[0027] A method for preparing a layered double metal hydroxide reinforced silica gel foam fire extinguishing agent according to a preferred embodiment of the present invention, in this embodiment, 60 parts of copper nitrate, 40 parts of aluminum nitrate, and 400 parts of water are mixed, stirred at room temperature for 1 hour to obtain a copper nitrate-aluminum nitrate mixed solution, 50 parts of sodium carbonate and 500 parts of water are mixed evenly, stirred at a temperature of 75°C, nitrogen protection, then the copper nitrate-aluminum nitrate mixed solution and 60 parts of naphthol phosphate are slowly added dropwise, and a sodium hydroxide solution with a concentration of 2 mol / L is added dropwise to maintain the pH value at 8.5. After the addition is completed, the mixture is transferred to a hydrothermal kettle and kept at 75°C for 24 hours. After high-speed centrifugation, deionized water washing, drying, and grinding, a phosphated copper aluminum layered double metal hydroxide is obtained for standby use;

[0028] Mix 50 parts of sodium fatty alcohol polyoxyethylene ether sulfate and 200 parts of water in a reaction kettle, stir at 40°C for 1 hour to obtain a sodium fatty alcohol polyoxyethylene ether sulfate aqueous solution for standby use; mix 20 parts of hydroxybutyl methylcellulose and 1000 parts of water in a reaction kettle, stir at room temperature for 16 hours to obtain a hydroxybutyl methylcellulose aqueous solution for standby use;

[0029] 200 parts of potassium silicate, 150 parts of sodium sulfate aqueous solution of fatty alcohol polyoxyethylene ether, 150 parts of hydroxybutyl methylcellulose aqueous solution and 450 parts of water were mixed and stirred at room temperature for 1 hour, then 30 parts of phosphated copper aluminum layered double metal hydroxide were added and stirred at room temperature for 30 minutes, and finally 20 parts of phosphoric acid were added and stirred at room temperature for 3 minutes to obtain a layered double metal hydroxide enhanced silicone gel foam fire extinguishing agent. Its gel time, viscosity, pH value, fire extinguishing time and back temperature ≤ 90°C time are shown in Table 1.

[0030] Table 1 Gel time, viscosity, pH value, fire extinguishing time and back temperature ≤ 90℃ time of the prepared layered double hydroxide enhanced silicone gel foam fire extinguishing agent

[0031]

[0032] As can be seen from Table 1, the layered double hydroxide enhanced silicone gel foam fire extinguishing agent in Example 1, Example 2, and Example 3 can quickly form a gel within 10 seconds, is neutral at room temperature, and has a certain fluidity, and can achieve a long-range spray effect; through the multi-functional synergistic effects of effective covering adhesion-cooling-free radical capture-combustible gas dilution-carbonization protection, etc., the efficient fire extinguishing and anti-reignition of 1A wood pile fire can be achieved within 40 seconds; through the stable carbon layer protection enhanced by the layered double hydroxide, under the flame burning condition of ≥800°C, the back temperature of the combustible wood board is ≤90°C for more than 21 minutes, showing a good fire barrier effect.

[0033] Test method: Take the layered double metal hydroxide enhanced silicone gel foam fire extinguishing agent prepared in Example 1, Example 2, and Example 3, and the main test method is as follows.

[0034] (1) Gel time: After the raw materials are mixed evenly, stir them magnetically. When the viscosity is greater than 100 mPa·s, record the time, which is the gel time.

[0035] (2) Fire extinguishing performance: Pine wood strips with a specification of 500 mm × 40 mm × 40 mm were built into a square woodpile, and the prepared fire extinguishing material was placed in a portable high-pressure spray device to conduct a fire extinguishing performance test.

[0036] (3) Fire barrier performance: A wooden board with a length, width and thickness of 100 mm × 100 mm × 5 mm was used as the substrate. The prepared material was coated on a wooden board with a length, width and thickness of 100 mm × 100 mm × 5 mm. The coating thickness was 5 mm. A K-type thermocouple probe was attached to the back of the sample. A butane spray gun with a flame temperature of about ≥ 800°C was used to ablate the sample at a distance of 10 cm from the upper surface. When the back temperature of the wooden board reached 90°C, the test was terminated and the time was recorded.

[0037] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a layered double metal hydroxide enhanced silica gel foam fire extinguishing agent, characterized in that The method comprises the following steps, and the parts of the materials used are parts by weight unless otherwise specified: (1) Preparation of phosphorylated layered double metal hydroxide: 1-200 parts of divalent metal nitrate, 1-100 parts of aluminum nitrate, and 10-1000 parts of water are mixed, and stirred at room temperature for 1 hour to obtain a metal salt mixed solution; 1-100 parts of sodium carbonate and 10-1000 parts of water are mixed evenly, and stirred at a temperature of 40-80°C, with nitrogen protection, and then the metal salt mixed solution and 5-150 parts of organic phosphate are slowly added dropwise, and a 2 mol / L sodium hydroxide solution is added dropwise to maintain the pH value at 8.5; after the addition is completed, the mixture is transferred to a hydrothermal autoclave, kept at 60-90°C for 12-36 hours, and after high-speed centrifugation, deionized water washing, drying, and grinding, the phosphorylated layered double metal hydroxide is obtained and set aside; (2) mixing 1 to 100 parts of sodium fatty alcohol polyoxyethylene ether sulfate and 10 to 1000 parts of water in a reaction kettle, stirring at 40° C. for 0.5 to 2 hours to obtain an aqueous solution of sodium fatty alcohol polyoxyethylene ether sulfate for standby use; mixing 1 to 100 parts of hydroxybutyl methylcellulose and 100 to 1000 parts of water in a reaction kettle, stirring at room temperature for 12 to 24 hours to obtain an aqueous solution of hydroxybutyl methylcellulose for standby use; (3) 20 to 2000 parts of silicate, 6 to 600 parts of fatty alcohol polyoxyethylene ether sodium sulfate aqueous solution, 6 to 600 parts of hydroxybutyl methylcellulose aqueous solution and 20 to 4000 parts of water are mixed, and stirred at room temperature for 1 hour; then 0.5 to 500 parts of phosphorylated layered double metal hydroxide are added, and stirred at room temperature for 30 minutes; finally, 2 to 200 parts of phosphoric acid are added, and stirred at room temperature for 0.5 to 5 minutes to obtain a layered double metal hydroxide reinforced silicone gel foam fire extinguishing agent.

2. The method for preparing the layered double metal hydroxide reinforced silica gel foam fire extinguishing agent according to claim 1, characterized in that: The divalent metal nitrate is one of magnesium nitrate, zinc nitrate, cobalt nitrate and copper nitrate.

3. The method for preparing the layered double metal hydroxide reinforced silica gel foam fire extinguishing agent according to claim 1, characterized in that: The organic phosphate is one or more of triethyl diphosphate, dodecyl phosphate, naphthol phosphate, and 3-aminopropyl monophosphate.

4. The method for preparing the layered double metal hydroxide reinforced silica gel foam fire extinguishing agent according to claim 1, characterized in that: The silicate is one or more of potassium silicate and tetramethylammonium silicate.

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