Pyrotechnic product capable of regulating ignition temperature based on transition metal hydroxide and preparation method of pyrotechnic product

Abstract

The invention relates to the technical field of pyrotechnic products, and discloses a pyrotechnic product for regulating ignition temperature and combustion reaction temperature based on transition metal hydroxide and a preparation method of the pyrotechnic product. The pyrotechnic composition product consists of an adhesive, a water-soluble pyrotechnic oxidant, a functional additive and a combustible agent, wherein the functional additive is transition metal hydroxide. Through co-crystallization or mixed crystal of pyrotechnic composition components and trace transition metal hydroxides and combustion catalysis of a water-soluble oxidant and carbohydrate mixed system, the ignition temperature of a pyrotechnic composition product is reduced, and the combustion reaction temperature is controllable.

Description

Technical Field

[0001] The invention belongs to the technical field of pyrotechnic products, and relates to a pyrotechnic product with ignition temperature regulated by transition metal hydroxide and a preparation method thereof. Background Art

[0002] Colored smoke agents use the heat and gas products released by the combustion of oxidants and combustibles in the agent to sublimate the dye and carry the dye into the air, thereby producing smoke of different colors. Traditional colored smoke agents generally use potassium chlorate as an oxidant and carbohydrates such as lactose, sucrose, and starch as combustibles. Potassium chlorate and sucrose are used as the combustion components of colored smoke agents, and the temperature during combustion is controlled below 500°C to ensure that the organic dye will not be carbonized by high temperature; potassium chlorate decomposes rapidly at low temperatures, making it an ideal oxidant for colored smoke agents; but potassium chlorate has poor antistatic properties, low energy storage stability, high sensitivity, and low safety. It poses major safety hazards during production, storage, and transportation, and is prohibited from use in civilian fireworks products.

[0003] Potassium perchlorate is selected as the oxidant, which shows strong stability in anti-static and energy storage. However, potassium perchlorate has a high decomposition temperature and a slow decomposition rate, which makes the combustion system composed of potassium perchlorate and carbohydrates have a high ignition temperature, a slow reaction rate and poor combustion continuity, affecting its application in colored smoke agents.

[0004] In order to overcome the defects of potassium perchlorate in colored smoke agents, a catalyst is introduced to increase the decomposition rate of potassium perchlorate and enhance the reaction activity of potassium perchlorate with carbohydrates. Related studies have reported the decomposition of potassium perchlorate using a single oxidant, but there have been no reports on the combustion catalysis of a mixed system composed of potassium perchlorate and lactose, as well as the catalysis of thermal reaction performance.

[0005] In recent years, aerosol fire extinguishing agents have attracted widespread attention due to their advantages such as high fire extinguishing efficiency, low cost, and easy use and maintenance. Compared with halon fire extinguishing agents that deplete ozone, thermal aerosol fire extinguishing agents have an ODP and GWP value of almost 0, and are environmentally friendly products that will not cause environmental damage. Since most of their formulas are solid powders, no pressure devices are used, and fires are extinguished by full flooding after ignition, they can be used in different places, such as airplanes, tanks, distribution boxes, kitchens, underground passages, and cinemas.

[0006] Thermal aerosol fire extinguishing agents use K-type fire extinguishing agents and S-type fire extinguishing agents. The main oxidant of K-type fire extinguishing agent is potassium nitrate, and its combustion products are highly corrosive. In order to solve the corrosive problem, S-type fire extinguishing agent was iterated, and its main oxidant is strontium nitrate. Researchers have conducted in-depth research on the formulation, fire extinguishing mechanism and application of thermal aerosol fire extinguishing agents, and have achieved many excellent results. However, whether it is potassium nitrate or strontium nitrate, there is still the problem of excessively high nozzle temperature.

[0007] Therefore, it is particularly important to provide a pyrotechnic powder product and a preparation method thereof that can adjust the ignition temperature and thus adjust the combustion reaction temperature, has a simple preparation method, is safe to operate, and is environmentally friendly. Summary of the invention

[0008] The present invention provides a pyrotechnic product based on regulating the ignition reaction temperature of transition metal hydroxide and a preparation method thereof. The pyrotechnic product comprises a binder, a water-soluble pyrotechnic oxidant, a functional additive and a combustible, wherein the functional additive is a transition metal hydroxide, and a pyrotechnic product with a low ignition temperature and a controllable combustion reaction temperature is prepared by co-crystallization of pyrotechnic components and trace amounts of transition metal hydroxides and combustion catalysis of a mixed system of oxidants and carbohydrates.

[0009] To achieve the above-mentioned object, the present invention provides a pyrotechnic product for regulating the ignition reaction temperature based on transition metal hydroxides, wherein the pyrotechnic product comprises an adhesive, a water-soluble pyrotechnic oxidant, a functional additive and a combustible agent; the functional additive is a transition metal hydroxide; the mass ratio of the adhesive, the water-soluble pyrotechnic oxidant, the functional additive and the combustible agent is 1:(8.2-11.6):(0.1-0.2):(4.1-10.2).

[0010] Preferably, the water-soluble pyrotechnic oxidant is any one or more of potassium nitrate, potassium perchlorate, sodium nitrate, strontium nitrate, and barium nitrate.

[0011] Preferably, the transition metal hydroxide is any one or more of copper hydroxide, iron hydroxide, iron nitrate, cobalt hydroxide, manganese oxyhydroxide and manganese carbonate.

[0012] Preferably, the combustible agent is any one or more of sucrose, lactose, carbon powder, talcum powder, melamine, dicyandiamide, and bio-resin.

[0013] Preferably, the binder is any one or more of synthetic resin, polyvinyl alcohol, dextrin, nitrocellulose, and gelatin.

[0014] The present invention also provides a method for preparing a pyrotechnic product based on regulating the ignition reaction temperature of a transition metal hydroxide, comprising:

[0015] Dissolving a transition metal hydroxide in deionized water, and adding an acid solution or an alkaline solution to completely dissolve the hydroxide, to obtain a solution A;

[0016] The water-soluble pyrotechnic oxidant and the combustible agent are mixed evenly, and are subjected to ultrasonic treatment to completely dissolve them in deionized water to obtain a solution B;

[0017] Solution A and solution B are mixed and then ultrasonically dispersed to obtain solution C;

[0018] The obtained solution C is freeze-dried and crystallized for 30 to 35 hours, the freeze-dried material is mixed evenly with the binder, and placed in an oven for aging for 6 to 7 hours to obtain a pyrotechnic product based on the ignition reaction temperature controlled by the transition metal hydroxide.

[0019] The present invention firstly utilizes the characteristics that transition metal hydroxides can be dissolved in water under weak acid or weak base conditions, and part of the main materials of pyrotechnics are also dissolved in water, so that the transition metal hydroxide and the main materials dissolved in water can form molecular contact in the aqueous solution. Secondly, the uniformly mixed solution is suddenly frozen by a freeze-drying device, and then the water is vacuum-drawn to form a highly uniform composite eutectic material or mixed crystal material; finally, the transition metal hydroxide is pyrolyzed into a transition metal oxide by means of high-temperature drying, so as to realize the combustion reaction of the pyrotechnics catalyzed by the transition metal oxide.

[0020] Preferably, the mass ratio of the deionized water to the transition metal hydroxide is 1:(0.01-0.02).

[0021] Preferably, the mass ratio of the deionized water to the mixture of the water-soluble pyrotechnic oxidant and the combustible agent is 1:(0.18-0.2).

[0022] Preferably, the alkaline solution is any one or more of ammonia water, sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate, and the acid solution is any one or more of formic acid, acetic acid, phosphoric acid, and hypochlorous acid.

[0023] Preferably, the freeze-dried crystals are covered with a thin film, which is pierced with holes and placed in a vacuum freeze dryer. The film can ensure that the material remains in the watch glass while the solvent sublimates smoothly.

[0024] Preferably, the oven drying temperature is 80-100° C., and aging can dehydrate copper hydroxide to generate copper oxide.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) The present invention uses a mixed system consisting of a water-soluble pyrotechnic oxidant and a carbohydrate as a combustion catalyst. Potassium perchlorate, as a strong oxidant, provides oxygen to the system during the combustion process and accelerates the oxidation reaction of organic matter. However, the decomposition of potassium perchlorate requires a relatively high temperature, while lactose, as an organic matter, can release a large amount of heat energy when it decomposes, providing additional energy for the decomposition of potassium perchlorate, increasing the reaction rate and lowering the ignition temperature at which the system starts to burn. The gaseous products (such as water vapor and carbon dioxide) generated by the decomposition of lactose increase the local temperature, further promoting the decomposition of potassium perchlorate, thereby releasing more oxygen, improving the combustion continuity, avoiding temperature fluctuations during the reaction process, and making the combustion more stable.

[0027] (2) The present invention uses transition metal hydroxides and pyrotechnic components to form co-crystals or mixed crystals. Co-crystals or mixed crystals refer to two or more chemical substances that form a uniform composite crystal structure during the crystallization process. The particle size of the co-crystals or mixed crystals can be controlled, so that these crystals have a larger specific surface area and can be in zero-distance contact with the combustible. Since the contact area between the reactants increases, the reaction rate is increased. At the same time, particles with smaller particle sizes can react at lower temperatures, reducing the ignition temperature. In summary, by controlling the component ratio and structure of the co-crystals or mixed crystals to adjust the crystal particle size, the temperature of the combustion reaction can be controlled, and the reaction heat release rate can be accurately controlled to ensure that the combustion process is carried out within the ideal temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of thermal decomposition of a pyrotechnic product prepared in Example 1 based on regulating the ignition reaction temperature by a transition metal hydroxide.

[0029] Figure 2 Schematic diagram of thermal decomposition of a pyrotechnic product prepared in Comparative Example 1 without a transition metal hydroxide to regulate the ignition reaction temperature.

[0030] Figure 3 Schematic diagram of thermal decomposition of a pyrotechnic product prepared in Comparative Example 2 without adding lactose and based on regulating the ignition reaction temperature by a transition metal hydroxide. DETAILED DESCRIPTION

[0031] The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.

[0032] Example 1

[0033] A method for preparing a pyrotechnic product based on regulating the ignition reaction temperature of a transition metal hydroxide comprises the following steps:

[0034] (1) Weigh 0-1 g of copper hydroxide, add it to 10 mL of deionized water, and treat it ultrasonically for 10-20 min. Then, add ammonia solution to adjust the pH value to weak alkalinity, let it stand and wait for it to completely dissolve or form a blue flocculent precipitate, and obtain solution A; weigh 1.16 g of potassium perchlorate and 0.68 g of lactose, add them to 10 mL of deionized water, and treat it ultrasonically for 10-20 min until it is completely dissolved, and obtain solution B; mix solution A and solution B, and treat them ultrasonically for 30-40 min until they are completely dissolved, and obtain solution C.

[0035] (2) Place solution C in a watch glass, cover it with a thin film, pierce it, and place it in a vacuum freeze dryer. Vacuum freeze dry for more than 30 to 35 hours until the solvent is completely sublimated to obtain a uniformly mixed freeze-dried material.

[0036] (3) 2 g of freeze-dried material was mixed evenly with 0.1 g of phenolic resin, placed in an oven at 80-100° C., and aged for 6-7 h (the purpose of high-temperature aging is to dehydrate copper hydroxide to form copper oxide), thereby obtaining a pyrotechnic product with an ignition reaction temperature controlled by a transition metal hydroxide.

[0037] Example 2

[0038] A method for preparing a pyrotechnic product based on regulating the ignition reaction temperature of a transition metal hydroxide comprises the following steps:

[0039] (1) Weigh 0.2 g of copper hydroxide, add it to 10 mL of deionized water, and treat it ultrasonically for 10 to 20 minutes. Then add ammonia solution to adjust the pH value to weak alkalinity, let it stand and wait for it to completely dissolve or form a blue flocculent precipitate, and obtain solution A; weigh 1.33 g of potassium perchlorate and 0.41 g of lactose, add them to 10 mL of deionized water, and treat it ultrasonically for 10v20 minutes until it is completely dissolved, and obtain solution B; mix solution A and solution B, and treat them ultrasonically for 30 to 40 minutes to make them completely dissolved, and obtain solution C.

[0040] (2) Place solution C in a watch glass, cover it with a thin film, pierce it, and place it in a vacuum freeze dryer. Vacuum freeze dry for more than 30 to 35 hours until the solvent is completely sublimated to obtain a uniformly mixed freeze-dried material.

[0041] (3) 2 g of the freeze-dried material was mixed evenly with 0.1 g of phenolic resin, placed in an oven at 80-100° C., and aged for 6-7 h (the purpose of high-temperature aging is to dehydrate copper hydroxide to form copper oxide), thereby obtaining a pyrotechnic product with an ignition reaction temperature controlled by a transition metal hydroxide.

[0042] Example 3

[0043] A method for preparing a pyrotechnic product based on regulating the ignition reaction temperature of a transition metal hydroxide comprises the following steps:

[0044] (1) Weigh 0.1 g of copper hydroxide, add it to 10 mL of deionized water, and treat it ultrasonically for 10 to 20 minutes. Then, add ammonia solution to adjust the pH value to weak alkalinity, let it stand and wait for it to completely dissolve or form a blue flocculent precipitate, and obtain solution A; weigh 0.82 g of potassium perchlorate and 1.02 g of lactose, add them to 10 mL of deionized water, and treat it ultrasonically for 10 to 20 minutes until they are completely dissolved, and obtain solution B; mix solution A and solution B, and treat them ultrasonically for 30 to 40 minutes until they are completely dissolved, and obtain solution C.

[0045] (2) Place solution C in a watch glass, cover it with a thin film, pierce it, and place it in a vacuum freeze dryer. Vacuum freeze dry for more than 30 to 35 hours until the solvent is completely sublimated to obtain a uniformly mixed freeze-dried material.

[0046] (3) 2 g of freeze-dried material was mixed evenly with 0.1 g of phenolic resin, placed in an oven at 80-100° C., and aged for 6-7 h (the purpose of high-temperature aging is to dehydrate copper hydroxide to form copper oxide), thereby obtaining a pyrotechnic product with an ignition reaction temperature controlled by a transition metal hydroxide.

[0047] Comparative Example 1

[0048] A method for preparing a pyrotechnic product based on regulating the ignition reaction temperature by a transition metal hydroxide, which is different from Example 1 in that copper hydroxide is not added in step (1).

[0049] Comparative Example 2

[0050] A method for preparing a pyrotechnic product based on regulating the ignition reaction temperature by a transition metal hydroxide, which is different from Example 1 in that lactose is not added in step (1).

[0051] The pyrotechnic product based on transition metal hydroxide to control the ignition reaction temperature prepared in Example 1 was placed in an aluminum crucible for differential scanning calorimetry (DSC) testing. The system was gradually raised from room temperature (25°C) to 800°C at a rate of 10°C / min under argon protection. The samples prepared in Comparative Examples 1 and 2 were tested under the same conditions.

[0052] according to Figure 1 and Figure 2 As shown, the combustion and decomposition temperature of the pyrotechnic product prepared in Example 1 with copper hydroxide co-crystal added is 544.1°C, and the combustion and decomposition temperature of the pyrotechnic product prepared in Comparative Example 1 without copper hydroxide added is 616.5°C. The peak reaction temperature of Example 1 is 72.4°C lower than that of Comparative Example 1. Experiments have shown that after adding copper hydroxide co-crystal, the contact area between the reactants is expanded, and particles with smaller particle size can react and decompose at a lower temperature, and the ignition and reaction temperature of the pyrotechnic product is significantly reduced. Figure 1 and Figure 3 As shown, the pyrotechnic product prepared in Example 1 uses a mixed catalytic system of potassium perchlorate and lactose as a catalyst, and the combustion decomposition temperature of the pyrotechnic product is reduced by 51.2°C compared with Example 2. Experiments have shown that the decomposition of lactose provides additional heat energy for potassium perchlorate, promotes its decomposition to release oxygen, improves the catalytic activity of potassium perchlorate in the reaction, and increases the rate of the overall reaction.

[0053] In summary, the co-crystallization or mixed crystal of the mixed catalytic system of potassium perchlorate and lactose with transition metal hydroxides can significantly reduce the ignition temperature and reaction temperature of pyrotechnic products, increase the reaction rate, and realize the controllable ignition temperature and combustion reaction temperature of pyrotechnic products.

[0054] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A pyrotechnic product based on transition metal hydroxide to control the ignition reaction temperature, characterized in that: The pyrotechnic product comprises an adhesive, a water-soluble pyrotechnic oxidant, a functional additive and a combustible; the functional additive is a transition metal hydroxide; the mass ratio of the adhesive, the water-soluble pyrotechnic oxidant, the functional additive and the combustible is 1:(8.2-11.6):(0.1-0.2):(4.1-10.2).

2. A pyrotechnic product based on controlling the ignition reaction temperature of a transition metal hydroxide according to claim 1, characterized in that: The water-soluble pyrotechnic oxidant is any one or more of potassium nitrate, potassium perchlorate, sodium nitrate, strontium nitrate and barium nitrate.

3. A pyrotechnic product based on controlling the ignition reaction temperature of a transition metal hydroxide according to claim 1, characterized in that: The transition metal hydroxide is any one or more of copper hydroxide, iron hydroxide, iron nitrate, cobalt hydroxide, manganese oxyhydroxide and manganese carbonate.

4. A pyrotechnic product based on controlling the ignition reaction temperature of a transition metal hydroxide according to claim 1, characterized in that: The combustible agent is any one or more of sucrose, lactose, carbon powder, talcum powder, melamine, dicyandiamide, and bio-resin.

5. A pyrotechnic product based on controlling the ignition reaction temperature of a transition metal hydroxide according to claim 1, characterized in that: The adhesive is any one or more of synthetic resin, polyvinyl alcohol, dextrin, nitrocellulose and gelatin.

6. A method for preparing a pyrotechnic product based on regulating the ignition reaction temperature of a transition metal hydroxide according to any one of claims 1 to 5, characterized in that: include: Dissolving a transition metal hydroxide in deionized water, and adding an acid solution or an alkaline solution to completely dissolve the hydroxide, to obtain a solution A; The water-soluble pyrotechnic oxidant and the combustible agent are mixed evenly, and subjected to ultrasonic treatment to completely dissolve them in water to obtain a solution B; Solution A and solution B are mixed and then ultrasonically dispersed to obtain solution C; The obtained solution C is freeze-dried and crystallized for 30 to 35 hours, the freeze-dried material is mixed evenly with the binder, and placed in an oven for aging for 6 to 7 hours to obtain a pyrotechnic product based on the ignition reaction temperature controlled by the transition metal hydroxide.

7. The method for preparing a pyrotechnic product based on regulating the ignition reaction temperature of a transition metal hydroxide according to claim 6, characterized in that: The mass ratio of the deionized water to the transition metal hydroxide is 1:(0.01-0.02); the mass ratio of the deionized water to the mixture of the water-soluble pyrotechnic oxidant and the combustible agent is 1:(0.18-0.2); the alkaline solution is any one or more of ammonia water, sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate; the acid solution is any one or more of formic acid, acetic acid, phosphoric acid, and hypochlorous acid.

8. The method for preparing a pyrotechnic product based on regulating the ignition reaction temperature of a transition metal hydroxide according to claim 6, characterized in that: The freeze-dried crystals are covered with a thin film, which is then punched and placed in a vacuum freeze dryer.

9. The method for preparing a pyrotechnic product based on regulating the ignition reaction temperature of a transition metal hydroxide according to claim 6, characterized in that: The oven drying temperature is 80-100°C.

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