Flame-retardant microcapsule, preparation method thereof and fire-extinguishing flame-retardant polymeric material

Abstract

The invention discloses a flame-retardant microcapsule and a preparation method thereof and a fire-extinguishing flame-retardant polymeric material.The flame-retardant microcapsule comprises a core material and a coating layer, the core material comprises a capsule core and an air release layer coating the outer side of the capsule core, the capsule core is composed of dust and a flame retardant according to the mass ratio of 1: (0.1-1), and the air release layer is one or more of sodium bicarbonate, zinc carbonate and magnesium carbonate. According to the flame-retardant microcapsule, the gas releasing agent of the gas releasing layer in the core material is heated to release CO2, after the pressure reaches a certain degree, the microcapsule in the coating layer explodes instantly, dust and the flame retardant are pressed to be smashed and dispersed all around under the action of the explosive force, and due to the fact that the dust and the flame retardant are fully mixed, the dust easily flies in the air, and the flame-retardant effect is achieved. And the flame retardant can be attached to the surface of dust, dispersed in air and deposited and covered on the surface of a surrounding flammable object, so that surrounding substances are not easy to combust, fire spreading is controlled, the fire extinguishing difficulty is reduced, and the flame retardant effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of polymers, and in particular to a flame retardant microcapsule and a preparation method thereof, and a fire extinguishing flame retardant polymer material. Background Art

[0002] Fire retardant polymers are a special type of material that can effectively slow down or prevent the spread of flames when a fire occurs, thereby protecting people's lives and property.

[0003] Flame retardants are often added to existing materials to improve the flame resistance of materials, prevent materials from being ignited and inhibit flame propagation. They mainly include the following:

[0004] (1) Inorganic flame retardants: This type of flame retardant works through its heat storage and thermal conductivity properties. Metal hydroxides such as aluminum hydroxide and magnesium hydroxide release crystal water and absorb a large amount of combustion heat energy when decomposed by heat, thereby reducing the surface temperature of the material.

[0005] (2) Halogen flame retardants (halogen series): including bromine and chlorine flame retardants, which release halogen elements during combustion and can inhibit the combustion chain reaction. However, the use of halogen flame retardants is restricted due to environmental and health issues.

[0006] (3) Phosphorus-based flame retardants: These flame retardants can form a carbon layer when burning, preventing the transfer of oxygen and heat. At the same time, the released phosphoric acid can act as a dehydrating agent, further enhancing the flame retardant effect.

[0007] (4) Nitrogen-based flame retardants: They interfere with the combustion process through chemical reactions and improve the flame retardancy of materials.

[0008] (5) Silicone flame retardants: usually used in combination with other flame retardants, they can improve the thermal stability of polymers and reduce smoke generation during combustion.

[0009] (6) Antimony-based flame retardants: act as synergists of halogen flame retardants to improve flame retardant efficiency.

[0010] (7) Boron-based and aluminum-magnesium-based flame retardants: These flame retardants generally have higher thermal stability and smoke suppression effects.

[0011] (8) Intumescent flame retardant (IFR): This type of flame retardant will foam and expand during heating to form a protective layer. It is usually a composite flame retardant with P, N, and C as the main core components.

[0012] (9) Mineral flame retardants: such as expandable graphite, which have the advantages of being environmentally friendly, non-toxic, abundant in resources and low in price.

[0013] (10) Nanomaterials: Nano-sized flame retardant particles can significantly improve the flame retardant effect of polymers due to their large specific surface area and high diffusivity.

[0014] (11) Microencapsulated flame retardant: The fire extinguishing agent is encapsulated in a flame-retardant polymer shell to form a safe and environmentally friendly fire extinguishing material.

[0015] (12) Halogen-free flame retardants: Since halogen flame retardants may produce toxic smoke during combustion, researchers are developing new halogen-free, environmentally friendly flame retardants.

[0016] (13) Bio-based flame retardants: This type of flame retardant is derived from organisms, is biodegradable, and has less impact on the environment.

[0017] In the prior art, polymer materials with added flame retardants have a limited effective area when automatically extinguishing a fire, and combustible items around the flame retardant materials will still catch fire, so the flame retardant function cannot be fully and effectively exerted. Summary of the invention

[0018] In order to overcome the deficiencies of the prior art, one of the objectives of the present invention is to provide a flame retardant microcapsule to solve the above-mentioned traditional technical problems.

[0019] The second object of the present invention is to provide a method for preparing the flame retardant microcapsules.

[0020] The third object of the present invention is to provide a fire extinguishing and flame retardant polymer material added with the above-mentioned flame retardant microcapsules.

[0021] One of the purposes of the present invention is achieved by the following technical solution:

[0022] A flame retardant microcapsule comprises a core material and a coating layer coated on the outside of the core material, wherein the core material comprises a capsule core and a gas release layer coated on the outside of the capsule core, wherein the capsule core is composed of dust and a flame retardant in a mass ratio of 1:(0.1-1) (such as 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, etc.), and the gas release layer is one or more of sodium bicarbonate, zinc carbonate, and magnesium carbonate.

[0023] The principle of the present invention is:

[0024] The gas releasing agent in the gas releasing layer in the core material releases CO2 when heated. When the pressure reaches a certain level, the microcapsules in the coating layer will explode instantly. Under the action of the explosion force, the dust and flame retardant are crushed and scattered around. Since the dust and flame retardant are fully mixed, the dust is easy to float in the air, and the flame retardant can attach to the surface of the dust and disperse in the air, and deposit and cover the surface of the surrounding flammable objects, making the surrounding materials difficult to burn, controlling the spread of fire, reducing the difficulty of fire extinguishing, and improving the flame retardant effect.

[0025] Furthermore, the flame retardant is an organic phosphorus flame retardant. When heated, the organic phosphorus flame retardant can produce a cross-linked solid substance or a carbonized layer with a more stable structure. The formation of the carbonized layer can prevent the polymer from further pyrolysis on the one hand, and prevent the thermal decomposition products inside it from entering the gas phase to participate in the combustion process on the other hand, and has the effects of isolating oxygen, isolating heat, isolating oxygen, and preventing combustible gas from escaping to the outside, thereby achieving the purpose of flame retardancy.

[0026] Furthermore, the organophosphorus flame retardant is one or more of phosphate flame retardants, phosphaphenanthrene flame retardants, phosphazene flame retardants, epichlorohydrin plastic flame retardants, alkyl phosphate flame retardants, aromatic phosphate flame retardants, polyphosphate flame retardants, etherified phosphate flame retardants, aminophosphorus ester flame retardants, phosphite flame retardants, organic phosphorus salt flame retardants, phosphorus oxide flame retardants, phosphorus heterocyclic compound flame retardants, polymer phosphorus (phosphonate) ester flame retardants, phosphorus-containing polyol flame retardants, and phosphorus-nitrogen compound flame retardants.

[0027] Among them, (1) Phosphate esters. This type of flame retardant can play a flame retardant and plasticizer role at the same time, and common ones include triphenyl phosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP) and bisphenol A bis(diphenyl phosphate) (BDP) phosphate. This type of flame retardant has good stability and solvent resistance, has little effect on the mechanical properties of the material, and has good hydrolysis resistance.

[0028] (2) Phosphaphenanthrene flame retardants, such as DOPO and its derivatives, provide good stability and hydrolysis resistance, and catalyze the flame retardant mechanism in the gas phase.

[0029] (3) Phosphazene flame retardants. They are rich in phosphorus and nitrogen and work through gas phase and condensed phase mechanisms.

[0030] (4) Epichlorohydrin plastic flame retardant. For example, DOPO can be directly reacted with epoxy resin or with hydroquinone and then with epichlorohydrin.

[0031] (5) Alkyl phosphates. Common ones include methyl, ethyl, isopropyl, etc. Since their decomposition products contain metal ions such as manganese, aluminum, and iron, they can produce multiple effects and are safer and more effective.

[0032] (6) Aromatic phosphates. The macromolecules have a high molecular weight and can enhance the mechanical properties of the material after curing. They are suitable for flame retardancy in high-end electronic products.

[0033] (7) Polyphosphate. The molecular structure of aromatic phosphate is further enhanced, and smoke and carbon layer are produced when decomposed, which can greatly improve the flame retardant grade of the material.

[0034] (8) Etherified phosphate esters. The decomposition products contain oxygen-containing compounds, which can extinguish flames and increase the softness of the material.

[0035] (9) Aminophosphoryl esters. They have good hydrophilicity and biocompatibility and are widely used in medical materials, food packaging and other fields.

[0036] Furthermore, the dust is industrial emissions and / or soil dust; dust is particulate matter suspended in the air that will not explode even when exposed to high temperatures, and dust comes from industrial emissions, soil dust, etc.; dust is not flammable and will not explode.

[0037] Furthermore, the dust is one or more of marble dust, zeolite dust, volcanic ash dust, and soil particle dust.

[0038] Furthermore, the coating layer is a microcapsule.

[0039] Furthermore, the microcapsule includes one or more of polymethyl methacrylate, chlorinated paraffin, sodium alginate, urea-formaldehyde resin, polyamide, polystyrene, polyoxymethylene, polyimide, polyphenylene ether, polyacrylamide, polyurethane, melamine resin, polycarbonate, polyvinylidene fluoride, and polytetrafluoroethylene.

[0040] Furthermore, the mass ratio of the gas release layer to the capsule core is 1:(0.1-0.8), such as 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, etc.

[0041] Furthermore, the mass ratio of the coating layer to the core material is 1:(0.1-0.8), such as 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, etc.

[0042] The second object of the present invention is achieved by adopting the following technical solution:

[0043] A method for preparing flame retardant microcapsules comprises the following preparation steps:

[0044] S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture;

[0045] S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying or atomizing, so that the gas releasing particles are wrapped on the outer surface of the mixture to form a core material;

[0046] S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

[0047] Furthermore, the average particle size of the flame retardant microcapsules is 3 μm to 50 μm.

[0048] The third object of the present invention is achieved by adopting the following technical solution:

[0049] A fire extinguishing flame retardant polymer material comprises the flame retardant microcapsule described above.

[0050] Furthermore, the added amount of the flame retardant microcapsules is 1 to 15% of the total weight of the material.

[0051] Furthermore, polymeric materials include building materials, electronic appliances, textiles, plastic products, rubber products, foam materials, coatings, etc.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The flame retardant microcapsules of the present invention release CO2 when heated by the gas releasing agent in the gas releasing layer in the core material. When the pressure reaches a certain level, the microcapsules in the coating layer explode instantly. Under the action of the explosion force, the dust and the flame retardant are crushed and dispersed around. Since the dust and the flame retardant are fully mixed, the dust is easy to float in the air, and the flame retardant can be attached to the surface of the dust and dispersed in the air, and deposited to cover the surface of the surrounding flammable objects, so that the surrounding materials are not easy to burn, the spread of fire is controlled, the difficulty of fire extinguishing is reduced, and the flame retardant effect is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a diagram of the cabinet before the test in the application test;

[0055] Figure 2 This is a picture of the cabinet on-site during the test process in the application test;

[0056] Figure 3 This is a picture of the on-site situation after the test in the application test. DETAILED DESCRIPTION

[0057] The present invention is further described below in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0058] Example 1

[0059] A flame retardant microcapsule comprises a core material and a coating layer coated on the outside of the core material, wherein the mass ratio of the coating layer to the core material is 1:0.1; the coating layer is sodium alginate; the core material comprises a capsule core and a gas release layer coated on the outside of the capsule core, wherein the mass ratio of the gas release layer to the capsule core is 1:0.7; the capsule core is composed of soil dust and DOPO in a mass ratio of 1:0.8; the gas release layer is sodium bicarbonate.

[0060] The flame retardant microcapsule comprises the following preparation steps:

[0061] S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture;

[0062] S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying, so that the gas releasing particles are wrapped around the outer surface of the mixture to form a core material;

[0063] S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

[0064] After testing, the average particle size of the flame retardant microcapsules was 10 μm. It was added to the production of non-woven fabrics at 2% of the total weight of the material to produce 1m×1m non-woven fabrics, and then the oxygen index was measured using an oxygen index tester (according to GB / T10707-2008), and its oxygen index was 25.5; the flame retardant grade was measured using a horizontal and vertical combustion tester (according to GB / T10707-2008), and its flame retardant grade was V2.

[0065] Example 2

[0066] A flame retardant microcapsule comprises a core material and a coating layer coated on the outside of the core material, wherein the mass ratio of the coating layer to the core material is 1:0.5; the coating layer is sodium alginate; the core material comprises a capsule core and a gas release layer coated on the outside of the capsule core, wherein the mass ratio of the gas release layer to the capsule core is 1:0.7; the capsule core is composed of soil dust and DOPO in a mass ratio of 1:0.8; the gas release layer is sodium bicarbonate.

[0067] The flame retardant microcapsule comprises the following preparation steps:

[0068] S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture;

[0069] S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying, so that the gas releasing particles are wrapped around the outer surface of the mixture to form a core material;

[0070] S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

[0071] After testing, the average particle size of the flame retardant microcapsules was 10 μm. It was added to the production of non-woven fabrics at 2% of the total weight of the material to produce 1m×1m non-woven fabrics, and then the oxygen index was measured using an oxygen index tester (according to GB / T10707-2008), and its oxygen index was 37.6; the flame retardant grade was measured using a horizontal and vertical combustion tester (according to GB / T10707-2008), and its flame retardant grade was V1.

[0072] Example 3

[0073] A flame retardant microcapsule comprises a core material and a coating layer coated on the outside of the core material, wherein the mass ratio of the coating layer to the core material is 1:1; the coating layer is sodium alginate; the core material comprises a capsule core and a gas release layer coated on the outside of the capsule core, wherein the mass ratio of the gas release layer to the capsule core is 1:0.7; the capsule core is composed of soil dust and DOPO in a mass ratio of 1:0.8; the gas release layer is sodium bicarbonate.

[0074] The flame retardant microcapsule comprises the following preparation steps:

[0075] S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture;

[0076] S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying, so that the gas releasing particles are wrapped around the outer surface of the mixture to form a core material;

[0077] S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

[0078] The flame retardant microcapsules were tested to have an average particle size of 10 μm. They were added to the production of non-woven fabrics at 2% of the total weight of the material to produce 1 m × 1 m non-woven fabrics, and then the oxygen index was measured using an oxygen index tester (in accordance with GB / T10707-2008), which was 46.8; the flame retardant grade was measured using a horizontal and vertical combustion tester (in accordance with GB / T10707-2008), which was V0.

[0079] From the above, it can be seen that when the mass ratio of the coating layer to the core material gradually increases, the oxygen index of the material also gradually increases, and the flame retardant grade increases from V2 to V0, and the flame retardant effect is better. Obviously, when the mass ratio of the coating layer to the core material is lower than 1:0.1, good flame retardancy cannot be achieved.

[0080] Example 4

[0081] A flame retardant microcapsule comprises a core material and a coating layer coated on the outside of the core material, wherein the mass ratio of the coating layer to the core material is 1:0.7; the coating layer is polymethyl methacrylate; the core material comprises a capsule core and a gas release layer coated on the outside of the capsule core, wherein the mass ratio of the gas release layer to the capsule core is 1:0.5; the capsule core is composed of soil dust and DOPO in a mass ratio of 1:0.8; the gas release layer is zinc carbonate.

[0082] The flame retardant microcapsule comprises the following preparation steps:

[0083] S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture;

[0084] S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying, so that the gas releasing particles are wrapped around the outer surface of the mixture to form a core material;

[0085] S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

[0086] After testing, the average particle size of the flame retardant microcapsules was 12 μm. It was added to the production of non-woven fabrics at 2% of the total weight of the material to produce 1m×1m non-woven fabrics, and then the oxygen index was measured using an oxygen index tester (according to GB / T10707-2008), and its oxygen index was 39.1; the flame retardant grade was measured using a horizontal and vertical combustion tester (according to GB / T10707-2008), and its flame retardant grade was V1.

[0087] Example 5

[0088] A flame retardant microcapsule comprises a core material and a coating layer coated on the outside of the core material, wherein the mass ratio of the coating layer to the core material is 1:0.8; the coating layer is sodium alginate; the core material comprises a capsule core and a gas release layer coated on the outside of the capsule core, wherein the mass ratio of the gas release layer to the capsule core is 1:0.4; the capsule core is composed of soil dust and triphenyl phosphate in a mass ratio of 1:0.6; the gas release layer is magnesium carbonate.

[0089] The flame retardant microcapsule comprises the following preparation steps:

[0090] S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture;

[0091] S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying, so that the gas releasing particles are wrapped around the outer surface of the mixture to form a core material;

[0092] S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

[0093] After testing, the average particle size of the flame retardant microcapsules was 30 μm. It was added to the production of non-woven fabrics at 2% of the total weight of the material to produce 1m×1m non-woven fabrics, and then the oxygen index was measured using an oxygen index tester (according to GB / T10707-2008), and its oxygen index was 40.2; the flame retardant grade was measured using a horizontal and vertical combustion tester (according to GB / T10707-2008), and its flame retardant grade was V1.

[0094] Comparative Example 1

[0095] A flame retardant microcapsule comprises a core material and a coating layer coated on the outside of the core material, wherein the mass ratio of the coating layer to the core material is 1:0.1; the coating layer is sodium alginate; the core material comprises a capsule core and a gas release layer coated on the outside of the capsule core, wherein the mass ratio of the gas release layer to the capsule core is 1:0.7; the capsule core is composed of soil dust and DOPO in a mass ratio of 0.8:1; the gas release layer is sodium bicarbonate.

[0096] The flame retardant microcapsule comprises the following preparation steps:

[0097] S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture;

[0098] S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying, so that the gas releasing particles are wrapped around the outer surface of the mixture to form a core material;

[0099] S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

[0100] After testing, the average particle size of the flame retardant microcapsules was 10 μm. It was added to the production of non-woven fabrics at 2% of the total weight of the material to produce 1m×1m non-woven fabrics, and then the oxygen index was measured using an oxygen index tester (according to GB / T10707-2008), and its oxygen index was 28.9; the flame retardant grade was measured using a horizontal and vertical combustion tester (according to GB / T10707-2008), and its flame retardant grade was V3.

[0101] It can be seen from the above that due to the change in the soil dust and DOPO composition of the capsule core, although the oxygen index increased by 3.4, the flame retardant level also increased by one level, resulting in a slight decrease in its flame retardancy.

[0102] Comparative Example 2

[0103] A flame retardant microcapsule comprises a core material and a coating layer coated on the outside of the core material, wherein the mass ratio of the coating layer to the core material is 1:1; the coating layer is sodium alginate; the core material comprises a capsule core and a gas release layer coated on the outside of the capsule core, wherein the mass ratio of the gas release layer to the capsule core is 0.1:0.7; the capsule core is composed of soil dust and DOPO in a mass ratio of 1:0.8; the gas release layer is sodium bicarbonate.

[0104] The flame retardant microcapsule comprises the following preparation steps:

[0105] S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture;

[0106] S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying, so that the gas releasing particles are wrapped around the outer surface of the mixture to form a core material;

[0107] S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

[0108] The flame retardant microcapsules were tested to have an average particle size of 10 μm. They were added to the production of non-woven fabrics at 2% of the total weight of the material to produce 1 m × 1 m non-woven fabrics, and then the oxygen index was measured using an oxygen index tester (in accordance with GB / T10707-2008), which was 67.1; the flame retardant grade was measured using a horizontal and vertical combustion tester (in accordance with GB / T10707-2008), which was V3.

[0109] It can be seen from the above that due to the change in the mass ratio of the gas release layer to the capsule core and the reduction in the amount of the gas release agent, although the amount of DOPO increased, resulting in an increase in the oxygen index, the flame retardant level also increased to V3, resulting in a significant decrease in its flame retardancy.

[0110] Application Testing

[0111] 1. Add the flame retardant microcapsules of Example 3 to the polypropylene adhesive, the amount of the flame retardant microcapsules added being 10% of the total weight of the material, to form a fire extinguishing sticker.

[0112] 2. In a charging cabinet, there are 4 compartments, each containing a lithium battery of an electric bicycle. There are fire extinguishing stickers on both sides of the charging cabinet, but no fire extinguishing stickers on other places. The cabinet before the test is as follows: Figure 1 shown.

[0113] The charging cabinet is safely set up in accordance with the "Design Specifications for Automatic Fire Alarm Systems" GB50116-2013, "Design Specifications for Automatic Sprinkler Fire Extinguishing Systems" GB50084-2017, "Fire Safety Specifications for Electric Bicycle Parking and Charging Places" (Shenzhen Landmark Public Draft) and "Video Security Monitoring System Engineering Design Specifications" GB50395-2007, with one monitoring camera system host, one indoor water sprinkler system, three explosion-proof hemispheric cameras and one infrared thermal imager.

[0114] 3. The test process is as follows:

[0115] 1) Test preparation, arrange the fire model according to the test requirements, and check the initial status of all equipment; 2) Turn on the monitoring camera system and infrared thermal imager to start recording; 3) Use gasoline to start a fire at the battery in the charging cabinet, and start the stopwatch; 4) Record the time when the sprinkler is turned on and the time when the combustion is extinguished; 5) For the monitoring camera system and infrared thermal imager, record the process from the occurrence of the fire to the complete extinguishing of the fire; 6) After the fire is extinguished, observe and record the burning of the battery and the charging cabinet, and the traces of smoke spread; 7) Clean up the charging cabinet and the test site.

[0116] The test process is as follows Figure 2 The on-site situation after the test is shown in Figure 3 shown.

[0117] 4. Test phenomenon: The battery on the lower right was ignited and the door of the charging cabinet was closed. The fire in the charging cabinet gradually increased, smoke overflowed from the gaps on the sides and top of the charging cabinet, and flames floated out from the exhaust holes on the side. As the temperature rose, the batteries on the upper layer also began to catch fire and spread layer by layer. The fire was extinguished by the sprinkler at 28 minutes and 8 seconds, and the fire was extinguished at 37 minutes and 11 seconds.

[0118] 5. Test conclusion: There is no fire extinguishing sticker in the charging cabinet. The high temperature generated by the burning of the bottom battery will gradually ignite the upper battery until all the batteries in the vertical direction are burned and exploded. The side of the charging cabinet is affixed with a fire extinguishing sticker, which has a blocking effect on the burning of the batteries in the charging grid below. This verifies that the fire extinguishing sticker has a good fire extinguishing effect on the initial fire of lithium batteries in a confined space.

[0119] 6. The records are shown in Table 1 below.

[0120] Table 1

[0121]

[0122] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A flame retardant microcapsule, characterized in that: It includes a core material and a coating layer coated on the outside of the core material, the core material includes a capsule core and a gas release layer coated on the outside of the capsule core, the capsule core is composed of dust and flame retardant in a mass ratio of 1: (0.1-1), and the gas release layer is one or more of sodium bicarbonate, zinc carbonate, and magnesium carbonate.

2. The flame retardant microcapsule according to claim 1, characterized in that: The flame retardant is an organic phosphorus flame retardant.

3. The flame retardant microcapsule according to claim 2, characterized in that: The organophosphorus flame retardant is one or more of phosphate flame retardants, phosphaphenanthrene flame retardants, phosphazene flame retardants, epichlorohydrin plastic flame retardants, alkyl phosphate flame retardants, aromatic phosphate flame retardants, polyphosphate flame retardants, etherified phosphate flame retardants, aminophosphorus ester flame retardants, phosphite flame retardants, organic phosphorus salt flame retardants, phosphorus oxide flame retardants, phosphorus heterocyclic compound flame retardants, polymer phosphorus (phosphonate) ester flame retardants, phosphorus-containing polyol flame retardants, and phosphorus-nitrogen compound flame retardants.

4. The flame retardant microcapsule according to claim 1, characterized in that: The dust is industrial emissions and / or soil dust.

5. The flame retardant microcapsule according to claim 1, characterized in that: The coating layer is a microcapsule.

6. The flame retardant microcapsule according to claim 5, characterized in that: The microcapsule includes one or more of polymethyl methacrylate, chlorinated paraffin, sodium alginate, urea-formaldehyde resin, polyamide, polystyrene, polyoxymethylene, polyimide, polyphenylene ether, polyacrylamide, polyurethane, melamine resin, polycarbonate, polyvinylidene fluoride, and polytetrafluoroethylene.

7. The flame retardant microcapsule according to claim 1, characterized in that: The mass ratio of the gas release layer to the capsule core is 1:(0.1-0.8).

8. The flame retardant microcapsule according to claim 1, characterized in that: The mass ratio of the coating layer to the core material is 1:(0.1-0.8).

9. A method for preparing the flame retardant microcapsules according to any one of claims 1 to 8, characterized in that: The method comprises the following preparation steps: S1: putting dust and flame retardant into a mixer and mixing them evenly to obtain a mixture; S2: putting the gas releasing agent into a fluidized bed granulator for granulation to obtain gas releasing particles, and then adding the gas releasing particles on the surface of the mixture by spraying or atomizing, so that the gas releasing particles are wrapped on the outer surface of the mixture to form a core material; S3: The core material is filled into the microcapsule through polymer coating controlled release technology to form a coating layer on the outer surface of the core material.

10. A fire retardant polymer material, characterized in that: The invention comprises the flame retardant microcapsules as described in any one of claims 1 to 8.

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