Organic-inorganic hybrid core-shell structure composite fire extinguishing particles and corresponding preparation method, fire extinguishing coating

Abstract

The application relates to a preparation method of organic-inorganic hybrid core-shell structure composite fire extinguishing particles, which comprises the following steps: (1) preparing a W1 / O primary emulsion: adding inorganic compounds into glycerol to prepare inorganic compound liquid; adding fluorine-2-methyl-3-pentanone into a mixed solution of water and ethanol as an inner water phase, dropping the inorganic compound liquid into the inner water phase, and preparing the W1 / O primary emulsion after homogenization; (2) preparing a W1 / O / W2 double emulsion; (3) microcapsulation treatment: under stirring, 0.5-1 mol / L high polymer material solution is added into the W1 / O / W2 double emulsion, the mixture is left to stand after stirring is completed, and the lower clear liquid is removed; an equal amount of chitosan solution is added, and stirring is conducted; the lower clear liquid is removed after standing, and washing is conducted with deionized water to remove unreacted raw materials. The application further provides corresponding organic-inorganic hybrid core-shell structure composite fire extinguishing particles and fire extinguishing paint. Through construction of a double emulsion multilayer system with obvious interface layering, a quick and effective fire extinguishing effect can be achieved.

Description

Technical Field

[0001] This invention belongs to the field of fire extinguishing materials technology, and particularly relates to the field of fluoro-2-methyl-3-pentanone technology, specifically to an organic-inorganic hybrid core-shell structure composite fire extinguishing particle and its corresponding preparation method and fire extinguishing coating. Background Technology

[0002] Fluoro-2-methyl-3-pentanone ( Halon is a novel, room-temperature liquid fluorinated fire extinguishing agent. It boasts high extinguishing efficiency and is environmentally friendly, making it an ideal alternative to halon (synthetic halon chemicals) fire extinguishing agents. Due to its non-conductive, volatile, and residue-free properties, it is highly suitable for electrical fire safety protection. However, its boiling point of only 49°C limits its use as an extinguishing agent. Currently, it is mainly used to replace halon fire extinguishers or in total flooding and localized application systems for Class B fire protection. In practical applications, it typically needs to be stored in fire extinguishing canisters or dedicated systems, limiting its convenience.

[0003] To adapt to more fire prevention and extinguishing scenarios, extinguishing agents can be encapsulated into microcapsules. Microencapsulation technology refers to encapsulating solids, liquids, or gases with polymer materials to create micro-encapsulations with particle sizes ranging from 1 to 5000 μm that are stable under normal conditions. Preparation methods are classified according to their principles into physical methods (spray drying, fluidized bed, spray freezing, electrostatic bonding, etc.), chemical methods (interfacial polymerization, in-situ polymerization, suspension crosslinking, etc.), and physicochemical methods (phase separation, single condensation, and complex condensation, etc.).

[0004] Currently, there are still challenges in the preparation of organic-inorganic hybrid core-shell composite fire extinguishing particles: First, the core material has a low boiling point and is easily volatile, and is prone to vaporization and dispersion during encapsulation and storage, resulting in a low encapsulation rate; Second, the wall material needs to be both dense to prevent volatilization and able to quickly respond to rupture or permeate and release the fire extinguishing agent during a fire, which places high demands on the design of the wall material and the release mechanism.

[0005] Existing fluoro-2-methyl-3-pentanone microcapsules mostly adopt a single-shell structure. Although they can achieve basic encapsulation, they have problems such as low encapsulation rate (usually below 75%), slow rupture rate after fire triggering, and delayed fire extinguishing response. They are difficult to meet the dual requirements of stable storage at room temperature and rapid fire extinguishing at high temperature at the same time. Summary of the Invention

[0006] The main objective of this invention is to address the above-mentioned problems by providing a double-shell, high-encapsulation-rate, fast-extinguishing organic-inorganic hybrid core-shell composite fire extinguishing particle, its corresponding preparation method, and fire extinguishing coating, thereby solving the technical defects of existing microcapsules, such as low encapsulation rate, slow fire extinguishing response, and poor structural stability.

[0007] The core improvement of this invention lies in the following: by adopting a W1 / O / W2 dual emulsion multilayer system + inorganic particle Pickering emulsification + chitosan / polymer dual-shell composite structure, and by precisely controlling the emulsification ratio, wall material composition and process parameters, efficient encapsulation of fluoro-2-methyl-3-pentanone and instantaneous release under fire conditions are achieved.

[0008] The purpose of this invention is to provide a method for preparing organic-inorganic hybrid core-shell composite fire extinguishing particles, the main feature of which is that the preparation method includes the following steps: (1) Preparation of W1 / O primary emulsion: Inorganic compounds are added to glycerol to prepare an inorganic compound liquid; Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase. An inorganic compound liquid was added dropwise to the inner aqueous phase, and after homogenization, a W1 / O primary emulsion was prepared. (2) Preparation of W1 / O / W2 double emulsion: The W1 / O primary emulsion was used as the oil phase and added to the chitosan solution. After homogenization, the W1 / O / W2 double emulsion was prepared. (3) Microencapsulation treatment: Under stirring, a polymer material solution of 0.5-1 mol / L is added to the W1 / O / W2 double emulsion. After stirring, the mixture is allowed to stand and the lower clear liquid is removed. Then, an equal volume of chitosan solution is added and stirred. After standing, the lower clear liquid is removed and the mixture is washed with deionized water to remove unreacted raw materials, forming organic-inorganic hybrid core-shell structure composite fire extinguishing particles.

[0009] Preferably, the inorganic compound is one or more of silicon dioxide, magnesium hydroxide, or aluminum hydroxide, which acts as a Pickering emulsifier to improve the stability of the emulsion interface, reduce the volatilization of fluoro-2-methyl-3-pentanone, and increase the encapsulation rate.

[0010] Preferably, the polymer material is one or more of acrylic resin, sodium alginate, phenolic resin, and polyimide, which forms an inner and outer double shell with chitosan. The inner layer is dense and prevents volatilization, while the outer layer is easily cracked at high temperatures.

[0011] Preferably, in the aqueous phase, the mass ratio of fluoro-2-methyl-3-pentanone, water and ethanol is 1 to 2:1:1, and in the W1 / O primary emulsion, the water-to-oil ratio is 1 to 5:5 to 9. In the W1 / O / W2 biemulsion, the oil-to-water ratio is 2-4:6-8; In the microencapsulation process, the volume ratio of the dual emulsion to the polymer solution is 1:2.

[0012] The present invention also provides an organic-inorganic hybrid core-shell structured composite fire extinguishing particle, the main feature of which is that it is made by the preparation method described above.

[0013] This invention also provides an organic-inorganic hybrid core-shell structure composite fire extinguishing particle coating, the main feature of which is that the organic-inorganic hybrid core-shell structure composite fire extinguishing particles are mixed with a mixing agent, wherein the mixing agent includes water-soluble acrylic resin, wetting agent, leveling agent and defoamer.

[0014] The present invention relates to organic-inorganic hybrid core-shell composite fire extinguishing particles and their corresponding preparation method and fire extinguishing coating. By constructing a multilayered double-emulsion system with distinct interfacial stratification, and using homogeneous emulsification as an auxiliary means, a double-shell fluoro-2-methyl-3-pentanone containing chitosan is prepared. The double-shell encapsulation ensures sufficient stability of the organic-inorganic hybrid core-shell composite fire extinguishing particle structure. Furthermore, the double-shell structure increases the specific surface area of ​​the microcapsules, allowing the shells on the microcapsule surface to rapidly burst upon reaching the activation temperature during fire extinguishing, releasing fluoro-2-methyl-3-pentanone for rapid and effective fire extinguishing. Further, the double-shell organic-inorganic hybrid core-shell composite fire extinguishing particles are thoroughly mixed with a water-soluble acrylic resin base through low-speed shearing to compensate for the insufficient encapsulation rate of the organic-inorganic hybrid core-shell composite fire extinguishing particle structure in existing technologies, and the inability of the microcapsules to rapidly burst and release fluoro-2-methyl-3-pentanone upon reaching the activation temperature during fire extinguishing, thus resulting in less than ideal fire extinguishing effects. Detailed Implementation

[0015] To provide a clearer understanding of the technical content of this invention, the following embodiments are provided in detail. However, it is important to note that these descriptions are merely for further illustrating the features and advantages of this invention, and not for limiting the scope of the claims.

[0016] The double-shell organic-inorganic hybrid core-shell composite fire extinguishing particles provided by this invention employ dual emulsion encapsulation and feature an innovative emulsion structure design. First, a primary emulsion is prepared using a homogenized emulsification-assisted process: fluoro-2-methyl-3-pentanone mixed liquid is dispersed in a silica / glycerol mixed oil phase using, for example, SiO2 nanoparticles as a Pickering emulsifier. Subsequently, the primary emulsion is introduced into a chitosan solution (aqueous phase) via homogenized emulsification, constructing a dual emulsion system with clearly defined interfacial stratification. Furthermore, the homogenized emulsification, through mechanical force and pressure, ensures more uniform emulsion dispersion and higher stability. The formation of a double-shell composite structure between chitosan and polymers also facilitates the particle formation process of the organic-inorganic hybrid core-shell composite fire extinguishing particles, increasing the encapsulation rate. The preparation method has the following advantages: (1) The amino group of chitosan is protonated under pH adjustment, thus becoming positively charged. Acrylic resin, sodium alginate, phenolic resin, polyimide and other substances are negatively charged in the overall liquid environment. Through the interaction of electrostatic adsorption, a stable shell is formed, thus giving the microcapsule good mechanical and chemical stability, thereby effectively protecting the active fluorine-2-methyl-3-pentanone inside; (2) The W1 / O / W2 double emulsion inside the microcapsule is a multilayer system, which more firmly encapsulates the release of active fluorine-2-methyl-3-pentanone.

[0017] Example 1 This embodiment 1 provides an organic-inorganic hybrid core-shell structured composite fire extinguishing particle coating, and the specific preparation steps are as follows: (1) Preparation of chitosan solution: Chitosan is dissolved in deionized water to prepare a chitosan solution with a concentration of 0.05 wt%, which is the W2 phase.

[0018] (2) Preparation of W1 / O primary emulsion: Preparation of the oil phase: Add silica to glycerol to prepare a 0.5 wt% silica liquid.

[0019] Mixed aqueous and oil phases: Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase (W1), wherein the mass ratio of fluoro-2-methyl-3-pentanone, water and ethanol was 1.5:1:1. Silica liquid was slowly added dropwise, and the water-oil ratio (W1:O) was controlled to be 1:9.

[0020] Homogenization: The W1 / O primary emulsion was prepared by homogenizing at 6000 r / min for 5 minutes using a homogenizer.

[0021] (3) Preparation of W1 / O / W2 double emulsion: Add external aqueous phase (W2): The prepared W1 / O primary emulsion is used as the oil phase and slowly added to the chitosan solution (W2) at an oil-water ratio of 2:6 (W1 / O:W2).

[0022] Homogenization: The W1 / O / W2 double emulsion was prepared by homogenizing at 5000 r / min for 5 minutes using a homogenizer.

[0023] (4) Microencapsulation treatment: Transfer the prepared W1 / O / W2 double emulsion to a beaker, and slowly add 0.5 mol / L acrylic resin solution under magnetic stirring, so that the volume ratio of double emulsion to acrylic resin solution is 1:2, and stir for 10 minutes; after stirring, let the mixture stand and remove the lower clear liquid; then add an equal volume of 0.05 wt% chitosan solution from step (1), and stir for 20 minutes; after standing, remove the lower clear liquid, and wash with deionized water to remove unreacted raw materials, forming organic-inorganic hybrid core-shell structure composite fire extinguishing particles.

[0024] (5) Preparation of microcapsule fire extinguishing coating: Step 1: Add water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEX F105, and defoamer ALLNEX D123 to a stirring device and stir at 1000 r / min for 30 minutes until the mixture is homogeneous, forming a mixture. The mass ratio of water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEX F105, and defoamer ALLNEX D123 is 82:0.8:0.8:1.4.

[0025] Step 2: Add the double-shell organic-inorganic hybrid core-shell structure composite fire extinguishing particles to the above mixture and stir at 450 r / min for 30 minutes until the mixture is uniform to obtain the organic-inorganic hybrid core-shell structure composite fire extinguishing particle fire extinguishing coating.

[0026] Example 2 This embodiment 2 provides an organic-inorganic hybrid core-shell structured composite fire extinguishing particle fire extinguishing coating, and the specific preparation steps are as follows: (1) Preparation of chitosan solution: Dissolve chitosan in deionized water to prepare a chitosan solution with a concentration of 0.1 wt%, which is the W2 phase.

[0027] (2) Preparation of W1 / O primary emulsion: Preparation of the oil phase: Magnesium hydroxide was dissolved in glycerol to prepare a 1.0 wt% magnesium hydroxide liquid.

[0028] Mixed aqueous and oil phases: Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase (W1), wherein the volume ratio of fluoro-2-methyl-3-pentanone, water and ethanol was 1:1:1. It was slowly added dropwise to magnesium hydroxide liquid, and the water-oil ratio (W1:O) was controlled at 2:5.

[0029] Homogenization: The W1 / O primary emulsion was prepared by homogenizing at 6000 r / min for 3 minutes using a homogenizer.

[0030] (3) Preparation of W1 / O / W2 double emulsion: Adding the external aqueous phase (W2): The prepared W1 / O primary emulsion is used as the oil phase and slowly added to the chitosan solution (W2) at an oil-water ratio of 3:7 (W1 / O:W2).

[0031] Homogenization: The W1 / O / W2 double emulsion was prepared by homogenizing at 5000 r / min for 5 minutes using a homogenizer.

[0032] (4) Microencapsulation treatment: The prepared W1 / O / W2 double emulsion was transferred to a beaker, and 0.1 mol / L phenolic resin solution was slowly added under magnetic stirring to make the volume ratio of double emulsion to phenolic resin solution 1:2. The mixture was stirred for 20 minutes. After stirring, the mixture was allowed to stand and the lower clear liquid was removed. Then an equal volume of 0.10 wt% chitosan solution from step (1) was added and stirred for 20 minutes. After standing, the lower clear liquid was removed and washed with deionized water to remove unreacted raw materials, forming organic-inorganic hybrid core-shell structure composite fire extinguishing particles.

[0033] (5) Preparation of microcapsule fire extinguishing coating: Step 1: Add water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEX F105, and defoamer ALLNEX D123 to a stirring device and stir at 1000 r / min for 30 minutes until the mixture is homogeneous, forming a mixture. The mass ratio of water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEX F105, and defoamer ALLNEX D123 is 82:0.8:0.8:1.4.

[0034] Step 2: Add the double-shell organic-inorganic hybrid core-shell structure composite fire extinguishing particles to the above mixture, so that the mass ratio of the double-shell organic-inorganic hybrid core-shell structure composite fire extinguishing particles to the above mixture is 15:85. Stir at 450 r / min for 30 minutes until the mixture is uniform to obtain the organic-inorganic hybrid core-shell structure composite fire extinguishing particle fire extinguishing coating.

[0035] Example 3 This embodiment 3 provides an organic-inorganic hybrid core-shell structured composite fire extinguishing particle coating, and the specific preparation steps are as follows: (1) Preparation of chitosan solution: Chitosan is dissolved in deionized water to prepare a chitosan solution with a concentration of 0.15 wt%, which is the W2 phase.

[0036] (2) Preparation of W1 / O primary emulsion: Preparation of the oil phase: Aluminum hydroxide was added to glycerol to prepare a 1.0 wt% aluminum hydroxide liquid.

[0037] Mixed aqueous and oil phases: Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase (W1), wherein the mass ratio of fluoro-2-methyl-3-pentanone, water and ethanol was 2:1:1. Aluminum hydroxide liquid was slowly added dropwise, and the water-oil ratio (W1:O) was controlled at 4:9.

[0038] Homogenization: The W1 / O primary emulsion was prepared by homogenizing at 7000 r / min for 4 minutes using a homogenizer.

[0039] (3) Preparation of W1 / O / W2 double emulsion: Adding the external aqueous phase (W2): The prepared W1 / O primary emulsion is used as the oil phase and slowly added to the chitosan solution (W2) at an oil-water ratio of 3:7 (W1 / O:W2).

[0040] Homogenization: The W1 / O / W2 double emulsion was prepared by homogenizing at 6000 r / min for 5 minutes using a homogenizer.

[0041] (4) Microencapsulation: The prepared W1 / O / W2 double emulsion was transferred to a beaker. Under magnetic stirring, 0.1 mol / L sodium alginate solution was slowly added to make the volume ratio of the double emulsion to the sodium alginate solution 1:2. The mixture was stirred for 20 minutes. After stirring, the mixture was allowed to stand and the lower clear liquid was carefully removed. Then, an equal volume of 0.15 wt% chitosan solution from step (1) was added and stirred for 20 minutes. After standing, the lower clear liquid was removed and washed with deionized water to remove unreacted raw materials, forming organic-inorganic hybrid core-shell composite fire extinguishing particles.

[0042] (5) Preparation of microcapsule fire extinguishing coating: Step 1: Add water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEX F105, and defoamer ALLNEX D123 to a stirring device and stir at 1000 r / min for 30 minutes until the mixture is homogeneous, forming a mixture. The mass ratio of water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEX F105, and defoamer ALLNEX D123 is 82:0.8:0.8:1.4.

[0043] Step 2: Add the double-shell organic-inorganic hybrid core-shell structure composite fire extinguishing particles to the above mixture A, and stir at 450 r / min for 30 minutes until the mixture is uniform to obtain the organic-inorganic hybrid core-shell structure composite fire extinguishing particle fire extinguishing coating.

[0044] Example 4 This embodiment 4 provides an organic-inorganic hybrid core-shell structured composite fire extinguishing particle coating, and the specific preparation steps are as follows: (1) Preparation of chitosan solution: Dissolve chitosan in deionized water to prepare a chitosan solution with a concentration of 0.2 wt%, which is the W2 phase.

[0045] (2) Preparation of W1 / O primary emulsion: Preparation of the oil phase: Silica was added to glycerol to prepare 1.5wt% silica liquids of different concentrations.

[0046] Mixed aqueous and oil phases: Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase (W1), wherein the mass ratio of fluoro-2-methyl-3-pentanone, water and ethanol was 1.5:1:1. Silica liquid was slowly added dropwise, and the water-oil ratio (W1:O) was controlled at 4:5.

[0047] Homogenization: Homogenize at 8000 r / min for 3 minutes using a homogenizer to prepare W1 / O primary emulsion.

[0048] (3) Preparation of W1 / O / W2 double emulsion: Adding the external aqueous phase (W2): The prepared W1 / O primary emulsion is used as the oil phase and slowly added to the chitosan solution (W2) at an oil-water ratio of 4:6 (W1 / O:W2).

[0049] Homogenization: The W1 / O / W2 double emulsion was prepared by homogenizing at 6000 r / min for 5 minutes using a homogenizer.

[0050] (4) Microencapsulation treatment: Transfer the prepared W1 / O / W2 double emulsion to a beaker, and slowly add 1 mol / L acrylic resin solution under magnetic stirring to make the volume ratio of the double emulsion acrylic resin solution 1:2. Stir for 20 minutes. After stirring, let the mixture stand and remove the lower clear liquid. Then add an equal volume of chitosan solution with a concentration of 0.2 wt% from step (1) and stir for 20 minutes. After standing, remove the lower clear liquid and wash with deionized water to remove unreacted raw materials to form organic-inorganic hybrid core-shell structure composite fire extinguishing particles.

[0051] (5) Preparation of microcapsule fire extinguishing coating: Step 1: Add water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEX F105, and defoamer ALLNEX D123 to a stirring device and stir at 1000 r / min for 30 minutes until the mixture is homogeneous, forming a mixture. The mass ratio of water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEX F105, and defoamer ALLNEX D123 is 82:0.8:0.8:1.4.

[0052] Step 2: Add the double-shell organic-inorganic hybrid core-shell structure composite fire extinguishing particles to the above mixture A, and stir at 450 r / min for 30 minutes until the mixture is uniform to obtain the organic-inorganic hybrid core-shell structure composite fire extinguishing particle fire extinguishing coating.

[0053] Comparative Example 1 The process is largely the same as in Example 2, except for the following steps: (4) The microencapsulation process involves adding only phenolic resin solution without adding chitosan solution a second time to form single-shell microcapsules.

[0054] Microencapsulation: The prepared W1 / O / W2 double emulsion was transferred to a beaker, and 0.1 mol / L phenolic resin solution was slowly added under magnetic stirring to make the volume ratio of double emulsion to phenolic resin solution 1:2. The mixture was stirred for 20 minutes. After stirring, the mixture was allowed to stand, the lower clear liquid was removed, and the mixture was washed with deionized water to remove unreacted raw materials to form single-shell microcapsules.

[0055] (5) Preparation of microcapsule fire extinguishing coating: Step 1: Add water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEXF105 and defoamer ALLNEXD123 to the stirring device and stir at 1000 r / min for 30 minutes until the mixture is uniform and forms a mixture. The mass ratio of water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEXF105 and defoamer ALLNEXD123 is 82:0.8:0.8:1.4.

[0056] Step 2: Add single-shell microcapsule particles to the above mixture, so that the mass ratio of single-shell microcapsule particles to the above mixture is 15:85, and stir at 450 r / min for 30 minutes until the mixture is uniform to obtain single-shell microcapsule fire extinguishing coating.

[0057] Comparative Example 2 The process is largely the same as in Example 2, except for the following steps: The W1 / O / W2 biemulsion preparation step was eliminated. Instead, the inner aqueous phase was directly added to the oil phase and homogenized to prepare a monoemulsion, which was then microencapsulated.

[0058] (1) Preparation of chitosan solution: Dissolve chitosan in deionized water to prepare a chitosan solution with a concentration of 0.1 wt%.

[0059] (2) Preparation of W1 / O primary emulsion: Preparation of the oil phase: Magnesium hydroxide was dissolved in glycerol to prepare a 1.0 wt% magnesium hydroxide liquid.

[0060] Mixed aqueous and oil phases: Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase (W1), wherein the volume ratio of fluoro-2-methyl-3-pentanone, water and ethanol was 1:1:1. It was slowly added dropwise to magnesium hydroxide liquid, and the water-oil ratio (W1:O) was controlled at 2:5.

[0061] Homogenization: Homogenize at 6000 r / min for 3 minutes using a homogenizer to prepare W1 / O primary emulsion.

[0062] (3) Microencapsulation treatment: The prepared W1 / O primary emulsion was transferred to a beaker, and 0.1 mol / L phenolic resin solution was slowly added under magnetic stirring to make the volume ratio of primary emulsion to phenolic resin solution 1:2. The mixture was stirred for 20 minutes. After stirring, the mixture was allowed to stand and the lower clear liquid was removed. Then an equal volume of 0.10 wt% chitosan solution from step (1) was added and stirred for 20 minutes. After standing, the lower clear liquid was removed and washed with deionized water to remove unreacted raw materials, forming organic-inorganic hybrid core-shell structure composite particles.

[0063] (5) Preparation of microcapsule fire extinguishing coating: Step 1: Add water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEXF105 and defoamer ALLNEXD123 to the stirring device and stir at 1000 r / min for 30 minutes until the mixture is uniform and forms a mixture. The mass ratio of water-soluble acrylic resin, wetting agent TG249, leveling agent ALLNEXF105 and defoamer ALLNEXD123 is 82:0.8:0.8:1.4.

[0064] Step 2: Add the double-shell organic-inorganic hybrid core-shell structure composite particles to the above mixture, so that the mass ratio of the double-shell organic-inorganic hybrid core-shell structure composite particles to the above mixture is 15:85. Stir at 450 r / min for 30 minutes until the mixture is uniform, and obtain the organic-inorganic hybrid core-shell structure composite particle fire extinguishing coating.

[0065] Comparative Example 3 The process is largely the same as in Example 2, except for the following steps: Sodium dodecyl sulfate is used instead of magnesium hydroxide, and no inorganic compounds are added.

[0066] (2) Preparation of W1 / O primary emulsion: Preparation of the oil phase: Sodium dodecyl sulfate was dissolved in glycerol to prepare a 1.0 wt% sodium dodecyl sulfate liquid.

[0067] Mixed aqueous and oil phases: Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase (W1), wherein the volume ratio of fluoro-2-methyl-3-pentanone, water and ethanol was 1:1:1. It was slowly added dropwise to magnesium hydroxide liquid, and the water-oil ratio (W1:O) was controlled at 2:5.

[0068] Homogenization: Homogenize at 6000 r / min for 3 minutes using a homogenizer to prepare W1 / O primary emulsion.

[0069] Comparative Example 4 The process is largely the same as in Example 2, except for the following steps: (2) Preparation of W1 / O primary emulsion: Preparation of the oil phase: Magnesium hydroxide was dissolved in glycerol to prepare a 1.0 wt% magnesium hydroxide liquid.

[0070] Mixed aqueous and oil phases: Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase (W1), wherein the volume ratio of fluoro-2-methyl-3-pentanone, water and ethanol was 1:1:1. It was slowly added dropwise to magnesium hydroxide liquid, and the water-oil ratio (W1:O) was controlled at 4:5.

[0071] Homogenization: Homogenize at 6000 r / min for 3 minutes using a homogenizer to prepare W1 / O primary emulsion.

[0072] Comparative Example 5 The process is largely the same as in Example 2, except for the following steps: (1) Preparation of hyaluronic acid solution: Dissolve hyaluronic acid in deionized water to prepare a hyaluronic acid solution with a concentration of 0.05 wt%, which is the W2 phase.

[0073] The embedding rate and extinguishing time of the organic-inorganic hybrid core-shell composite particles obtained in Examples 1 to 4 and Comparative Examples 1 to 5 were tested. The embedding rate of the organic-inorganic hybrid core-shell composite particles was determined by thermogravimetric analysis, and the specific test method is as follows: The thermal stability of organic-inorganic hybrid core-shell composite particles was analyzed using differential scanning calorimetry (DSC). 2.0 mg of sample was accurately weighed and placed in an aluminum box, the center of which was punctured and then sealed. An empty aluminum box under identical conditions was used as a reference. The core material of the fluoro-2-methyl-3-pentanone was completely decomposed at a rate of 10 °C / min from 25 °C to 330 °C. The wall material was then completely decomposed at a rate of 330 °C to 800 °C. The entire process was conducted under nitrogen (N2) with a purge gas flow rate of 20 mL / min and a protective gas flow rate of 60 mL / min. Each sample was measured twice.

[0074] The formula for calculating the embedding rate is as follows: Test method for fire extinguishing time of organic-inorganic hybrid core-shell composite particles: The test was conducted at room temperature (25±2℃) and relative humidity ≤50%. The combustion chamber was left to stand for 10 minutes to ensure uniform air circulation. Heptane was ignited, and after the flame stabilized for 5 seconds, the microcapsules were observed to see if they ruptured automatically due to thermal radiation (the trigger temperature is usually 140–180℃). A high-speed camera was activated, and timing began from the moment of ignition. Each set of conditions was repeated at least 3 times, and the average value was taken. The results are shown in Table 1 below.

[0075] Based on the above experimental results: The present invention utilizes the synergistic effect of dual emulsions, dual shells, and inorganic emulsifiers to achieve an encapsulation rate of up to 89.6%, which is more than 15% higher than single-shell, single-emulsion, and inorganic emulsifier-free solutions. The fire extinguishing time is as fast as 0.30 seconds, which is more than 50% shorter than conventional methods, achieving instantaneous fire extinguishing; After 30 days of storage at room temperature, the core material residue rate is ≥91%, which is much higher than that of conventional microcapsules (≤80%), and the storage stability is significantly improved.

[0076] In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, this specification should be considered illustrative rather than restrictive.

Claims

1. A method for preparing organic-inorganic hybrid core-shell structured composite fire extinguishing particles, characterized in that, The preparation method includes the following steps: (1) Preparation of W1 / O primary emulsion: Inorganic compounds are added to glycerol to prepare an inorganic compound liquid; Fluoro-2-methyl-3-pentanone was added to a mixed solution of water and ethanol as the inner aqueous phase. An inorganic compound liquid was added dropwise to the inner aqueous phase, and after homogenization, a W1 / O primary emulsion was prepared. (2) Preparation of W1 / O / W2 double emulsion: The W1 / O primary emulsion was used as the oil phase and added to the chitosan solution. After homogenization, the W1 / O / W2 double emulsion was prepared. (3) Microencapsulation treatment: Under stirring, a polymer material solution of 0.5-1 mol / L is added to the W1 / O / W2 double emulsion. After stirring, the mixture is allowed to stand and the lower clear liquid is removed. Then, an equal volume of chitosan solution is added and stirred. After standing, the lower clear liquid is removed and the mixture is washed with deionized water to remove unreacted raw materials, forming organic-inorganic hybrid core-shell structure composite fire extinguishing particles.

2. The method for preparing organic-inorganic hybrid core-shell structured composite fire extinguishing particles according to claim 1, characterized in that, The inorganic compound is one or more of silicon dioxide, magnesium hydroxide, or aluminum hydroxide.

3. The method for preparing organic-inorganic hybrid core-shell structured composite fire extinguishing particles according to claim 1, characterized in that, The polymer material is one or more of acrylic resin, sodium alginate, phenolic resin, and polyimide.

4. The method for preparing organic-inorganic hybrid core-shell structured composite fire extinguishing particles according to claim 1, characterized in that, In the aqueous phase, the mass ratio of fluoro-2-methyl-3-pentanone, water and ethanol is 1 to 2:1:1, and in the W1 / O primary emulsion, the water-oil ratio is 1 to 5:5 to 9. In the W1 / O / W2 biemulsion, the oil-to-water ratio is 2-4:6-8; In the microencapsulation process, the volume ratio of the dual emulsion to the polymer solution is 1:

2.

5. An organic-inorganic hybrid core-shell structured composite fire extinguishing particle, characterized in that, It is prepared by any one of claims 1 to 4.

6. An organic-inorganic hybrid core-shell structured composite fire extinguishing granular coating, characterized in that, The organic-inorganic hybrid core-shell structure composite fire extinguishing particles as described in claim 5 are mixed with a mixing agent, wherein the mixing agent includes water-soluble acrylic resin, wetting agent, leveling agent and defoamer.

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