Fire extinguishing microcapsule, fire extinguishing tape and application thereof

Abstract

The present invention provides a fire extinguishing microcapsule, comprising a capsule core and a capsule wall, wherein the core-to-wall ratio is 2:1-4:1, the rupture temperature of the capsule wall is greater than the boiling point of the capsule core, the capsule core comprises a first fire extinguishing agent and a second fire extinguishing agent, the first fire extinguishing agent is perfluorohexanone, and the molecular structure of the second fire extinguishing agent satisfies the general formula I: the carbon atoms contained in R1 are less than 3. The fire extinguishing microcapsule has good fire extinguishing performance and a low loss rate in normal temperature storage, and the fire extinguishing microcapsule still has good fire extinguishing and cooling capabilities after long-term storage.

Description

Technical Field

[0001] The invention belongs to the field of fire extinguishing agents, and in particular relates to a fire extinguishing microcapsule, a fire extinguishing tape and applications thereof. Background Art

[0002] Today, with modern technology being quite advanced, fire is still one of the most common emergency disasters. Fire not only causes a large amount of wealth loss, takes away people's health and lives, but also causes environmental pollution and damage to ecological balance, indirectly threatening human survival. Therefore, fire prevention and fire fighting are still themes that cannot be ignored in the contemporary era.

[0003] Perfluorohexanone is a green, environmentally friendly fire extinguishing agent with high fire extinguishing efficiency. However, perfluorohexanone has a low boiling point and is easy to volatilize. Before actual fire extinguishing, perfluorohexanone is easily lost during storage and cannot achieve the expected optimal fire extinguishing effect.

[0004] Therefore, in order to extend the long-term storage stability of perfluorohexanone and to achieve efficient fire extinguishing, it is necessary to seek a fire extinguishing microcapsule that uses perfluorohexanone and maintains high fire extinguishing performance and low loss rate. Summary of the invention

[0005] The purpose of the present invention is to provide a fire extinguishing microcapsule, a fire extinguishing tape and application thereof. The fire extinguishing microcapsule has good fire extinguishing performance and low loss rate.

[0006] According to a first aspect of the present invention, a fire extinguishing microcapsule is provided, comprising a capsule core and a capsule wall, wherein the mass ratio of capsule core to capsule wall is 2:1 to 4:1, the rupture temperature of the capsule wall is greater than the boiling point of the capsule core, the capsule core comprises a first fire extinguishing agent and a second fire extinguishing agent, the first fire extinguishing agent is perfluorohexanone, and the molecular structure of the second fire extinguishing agent satisfies the general formula I: R 1 Contains less than 3 carbon atoms.

[0007] First, this solution uses green and environmentally friendly perfluorohexanone as the first fire extinguishing agent. At high temperatures, perfluorohexanone can be vaporized at the moment of being released. Through gas fire extinguishing, the fire loss can be minimized, and secondary damage to the burning object can be avoided during the fire extinguishing process. However, perfluorohexanone is easy to volatilize at room temperature, resulting in the loss of perfluorohexanone in the fire extinguishing tape before the fire occurs. Therefore, the present invention blends the first fire extinguishing agent with the second fire extinguishing agent as the capsule core of the fire extinguishing microcapsule, which can make the room temperature storage retention rate of the capsule core higher than the room temperature storage retention rate of perfluorohexanone. Compared with the microcapsule using only the first fire extinguishing agent perfluorohexanone as the capsule core, the capsule core loss rate of the fire extinguishing microcapsule provided by the present invention is lower, and the fire extinguishing performance is good. The boiling point of the azeotropic liquid is not only related to the boiling point size corresponding to the components constituting the azeotropic liquid, but also to the size of the mixing free energy. Generally speaking, azeotropes include positive azeotropes and negative azeotropes. Positive azeotropes are azeotropes whose boiling points are lower than the boiling point temperature of any component, while negative azeotropes are azeotropes whose boiling points are higher than the boiling point temperature of any component. However, through long-term exploration and experiments by the inventors, it was found that the azeotrope composed of the second fire extinguishing agent satisfying the general formula I and the first fire extinguishing agent perfluorohexanone has a boiling point temperature between the temperatures of the first fire extinguishing agent and the second fire extinguishing agent. As a result, the fire extinguishing microcapsules can be triggered when the external ambient temperature is high, and have a low loss rate when stored at room temperature. In addition, by adjusting the mass ratio of the capsule core to the capsule wall, the obtained fire extinguishing microcapsules have both good fire extinguishing performance and low loss rate, which effectively improves the fire extinguishing and cooling ability of the fire extinguishing microcapsules after storage.

[0008] Preferably, the R of the second fire extinguishing agent is 1 At least one selected from methyl, ethyl, trifluoromethyl and pentafluoroethyl.

[0009] Preferably, the R of the second fire extinguishing agent is 1 At least one selected from methyl and ethyl.

[0010] Select R 1 When a compound having a methyl group or an ethyl group and conforming to the general formula I is used as the second fire extinguishing agent, the polarity of the second fire extinguishing agent is similar to that of the first fire extinguishing agent, so that the first fire extinguishing agent and the second fire extinguishing agent have good compatibility, and the boiling point of the second fire extinguishing agent is higher than that of the first fire extinguishing agent, so that the azeotrope constituting the capsule core can have a suitable boiling point, which can not only quickly vaporize at high temperature to extinguish the fire, but also reduce the amount of volatilization loss of effective fire extinguishing components under normal temperature storage conditions.

[0011] Preferably, the second fire extinguishing agent is selected from at least one of methyl nonafluorobutyl ether and ethyl nonafluorobutyl ether.

[0012] Preferably, the second fire extinguishing agent is ethyl nonafluorobutyl ether.

[0013] Preferably, calculated by mass, the first fire extinguishing agent: the second fire extinguishing agent = 3-5:1.

[0014] By blending in the above mass ratio, the storage stability of the capsule core can be further increased, and the azeotropic liquid can have excellent fire extinguishing performance.

[0015] Preferably, the capsule further comprises a capsule shell, which is wrapped outside the capsule wall, and the rupture temperature of the capsule shell is greater than the rupture temperature of the capsule wall.

[0016] Arranging a capsule shell on the outside of the capsule wall can further reduce the loss rate of the capsule core in the fire extinguishing microcapsule, and because the rupture temperature of the capsule shell is greater than the rupture temperature of the capsule wall, when the temperature of the external environment reaches the rupture temperature of the capsule shell, the capsule wall wrapped by the capsule shell will also rupture, and can release the effective fire extinguishing component as the capsule core. Therefore, even if the capsule shell is arranged on the outermost side of the fire extinguishing microcapsule, it will not seriously hinder the fire extinguishing triggering of the fire extinguishing microcapsule.

[0017] Preferably, the rupture temperature of the capsule shell is 120-150°C.

[0018] The rupture temperature of the capsule shell will affect the release timing of the fire extinguishing microcapsule. When the temperature of the external environment reaches the rupture temperature of the capsule shell, the fire extinguishing microcapsule will release effective fire extinguishing ingredients to cool down the environment and extinguish the open flame. Therefore, the rupture temperature of the capsule shell can be consciously set according to the material that needs to be cooled and protected. The temperature of thermal runaway of lithium batteries is around 120°C, that is, when the rupture temperature of the capsule shell is 120-150°C, the fire extinguishing microcapsule begins to rupture at the early stage of thermal runaway of lithium batteries and quickly releases fire extinguishing ingredients, so that the fire extinguishing microcapsule can be used to protect lithium batteries and reduce the losses caused by thermal runaway of batteries.

[0019] Preferably, the capsule wall is made of gelatin, the capsule shell is made of gelatin and gum arabic, and the mass ratio of gelatin to gum arabic is 1:1.

[0020] When the selected materials meet the above conditions, the rupture temperature of the capsule shell will be greater than the rupture temperature of the capsule wall, the rupture temperature of the capsule wall is greater than the boiling point of the capsule core, and the capsule shell composed of gelatin and gum arabic at a mass ratio of 1:1 has a corresponding rupture temperature in the range of 120-150°C. Moreover, the capsule shell and the capsule wall have good compatibility. After the fire extinguishing microcapsules are stored, the stratified state of the capsule shell and the capsule wall can still be maintained. During the storage period, neither the capsule shell nor the capsule wall is broken, nor does it fuse with each other.

[0021] Preferably, the capsule material further comprises a reinforcing agent, and the reinforcing agent is montmorillonite.

[0022] Preferably, the capsule material further comprises a cross-linking agent, and the cross-linking agent is sodium polyphosphate.

[0023] Preferably, the thickness of the capsule shell is 5 to 10 μm, the thickness of the capsule wall is 5 to 10 μm, and the average particle size D of the fire extinguishing microcapsules is50 5~100μm.

[0024] By controlling the thickness of the capsule wall and capsule shell of the fire-extinguishing microcapsule, the fire extinguishing temperature of the fire-extinguishing microcapsule can be accurately controlled; and by controlling the average particle size of the fire-extinguishing microcapsule, the release rate, embedding rate and storage stability of the fire-extinguishing material can also be improved.

[0025] According to a second aspect of the present invention, there is provided a fire extinguishing tape, comprising a fire extinguishing layer, wherein the fire extinguishing layer comprises the above-mentioned fire extinguishing microcapsules.

[0026] The fire extinguishing tape provided by the present invention adopts fire extinguishing microcapsules as effective components, which can effectively control the fire and prevent the fire from spreading.

[0027] When the fire extinguishing microcapsules meet the above conditions, it can ensure that the fire extinguishing material in the fire extinguishing tape is within the effective content range, and the fire extinguishing microcapsules will not be exposed to the outside, reducing the possibility of loss and failure of the effective ingredients.

[0028] Preferably, the fire extinguishing layer further comprises a resin medium, and the resin medium is selected from at least one of phenolic resin and urea-formaldehyde resin.

[0029] By controlling the resin medium as a dispersion medium in the fire extinguishing layer, the dispersion of the fire extinguishing microcapsules in the fire extinguishing layer is improved to avoid precipitation or even aggregation of the fire extinguishing microcapsules during drying, which may cause the first microcapsules to become ineffective during storage. In addition, when the external environment temperature reaches the release temperature of the fire extinguishing microcapsules, the resin medium will not hinder the fire extinguishing microcapsules from releasing effective fire extinguishing components.

[0030] According to a third aspect of the present invention, there is provided an application of the above-mentioned fire extinguishing tape in the safety prevention and control of thermal runaway of a power battery.

[0031] With the rapid development of the economy and the progress of modern science and technology, the power battery industry has also increased its safety requirements for lithium-ion batteries. Power batteries are prone to thermal runaway, which seriously affects the safety of electric vehicles and restricts the large-scale promotion of electric vehicles. The present invention applies the above-mentioned fire extinguishing tape to the safety prevention and control of thermal runaway of power batteries, which not only has a strong fire extinguishing effect and high practicality, but also has a long storage validity period. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] Example 1

[0034] (1) Preparation of fire extinguishing microcapsules

[0035] The fire extinguishing microcapsules prepared in this embodiment use the first fire extinguishing agent and the second fire extinguishing agent as the capsule core, gelatin as the capsule wall, and gelatin and gum arabic as the capsule shell. Perfluorohexanone is selected as the first fire extinguishing agent, and ethyl nonafluorobutyl ether is selected as the second fire extinguishing agent, wherein the CAS number of ethyl nonafluorobutyl ether is 163702-05-4, the core-to-wall ratio is 3:1, and ethyl nonafluorobutyl ether is preferably Novec TM 7200 electronic fluoride liquid products.

[0036] In the raw materials for preparing the capsule core, the first fire extinguishing agent: the second fire extinguishing agent = 4:1; in the raw materials for preparing the capsule shell, gelatin: gum arabic = 1:1. The raw materials for preparing the capsule wall also include a reinforcing agent and a crosslinking agent. In this embodiment, montmorillonite is used as the reinforcing agent and sodium polyphosphate is used as the crosslinking agent.

[0037] The fire extinguishing microcapsules are prepared according to the following steps:

[0038] S1. According to the types and proportions of the above raw materials, the first fire extinguishing agent and the second fire extinguishing agent are uniformly mixed to obtain an azeotropic liquid, and the azeotropic point of the azeotropic liquid is measured to be 52° C. Using water as a solvent, a gelatin solution with a concentration of 3%, a cross-linking agent solution with a concentration of 5%, and an enhancer solution with a concentration of 0.05% are prepared respectively.

[0039] S2. Add the azeotropic solution prepared in S1 to the gelatin solution and stir for five minutes, then add the crosslinker solution and the enhancer solution, stir evenly, and prepare the first precursor emulsion.

[0040] S3, adjusting the pH value of the first precursor emulsion to 4.0, performing a coagulation reaction at 25°C for 1 hour, cooling down, and mixing the first precursor emulsion with a curing agent, glutaraldehyde, uniformly, performing a curing reaction at 10°C for 1 hour, and then performing a curing reaction at 25°C for 2 hours. Filtering, separating, washing, and centrifuging to obtain a fire extinguishing microcapsule intermediate.

[0041] S4, using water as solvent, according to the mass ratio of gelatin: gum arabic = 1:1, prepare a capsule shell solution with a concentration of 12%. And mix the fire extinguishing microcapsule intermediate in S3 with the capsule shell solution at 40°C, stir for 1 hour, and prepare the second precursor emulsion. Mix the curing agent glutaraldehyde with the second precursor emulsion, filter and separate, and freeze-dry to prepare the fire extinguishing microcapsules.

[0042] In the prepared fire-extinguishing microcapsules, the rupture temperature of the capsule wall is 100°C, and the rupture temperature of the capsule shell is 150°C.

[0043] (2) Preparation of fire extinguishing tape

[0044] The fire extinguishing tape provided in this embodiment comprises a fire extinguishing layer; the fire extinguishing layer comprises the fire extinguishing microcapsules prepared in the above (1) and a resin medium, wherein the resin medium is selected from phenolic resin.

[0045] The fire extinguishing tape is prepared according to the following steps:

[0046] The fire extinguishing microcapsules and the resin medium were mixed in a mass ratio of 4:1, coated on the substrate, dried and aged at 60°C for 1 day, and then stored.

[0047] Example 2

[0048] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that an equal mass of methyl nonafluorobutyl ether is used to replace the ethyl nonafluorobutyl ether used in Example 1. The CAS number of methyl nonafluorobutyl ether is 163702-07-6, and the methyl nonafluorobutyl ether is preferably Novec TM The product of 7100 electronic fluoride liquid. The other raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0049] Example 3

[0050] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that an equal mass of trifluoromethyl nonafluorobutyl ether is used to replace the ethyl nonafluorobutyl ether used in Example 1. The CAS number of trifluoromethyl nonafluorobutyl ether is 559-29-5. The rest of the raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0051] Example 4

[0052] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that an equal mass of pentafluoroethyl nonafluorobutyl ether is used to replace the ethyl nonafluorobutyl ether used in Example 1. The CAS number of pentafluoroethyl nonafluorobutyl ether is 71546-78-6. The rest of the raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0053] Example 5

[0054] This example prepares a fire extinguishing tape by referring to the method provided in Example 1. The difference between this example and Example 1 is that in the process of preparing the fire extinguishing microcapsules, a core-to-wall ratio of 2:1 is used. The rest of the raw material ratios and the preparation method are strictly consistent with those in Example 1.

[0055] Example 6

[0056] This example prepares a fire extinguishing tape by referring to the method provided in Example 1. The difference between this example and Example 1 is that in the process of preparing the fire extinguishing microcapsules, a core-to-wall ratio of 4:1 is used. The rest of the raw material ratios and the preparation method are strictly consistent with those in Example 1.

[0057] Example 7

[0058] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that in the raw materials for preparing the capsule core, the mass ratio of the first fire extinguishing agent to the second fire extinguishing agent is 2:1. The other raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0059] Example 8

[0060] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that in the raw materials for preparing the capsule core, the mass ratio of the first fire extinguishing agent to the second fire extinguishing agent is 3:1. The other raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0061] Example 9

[0062] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that in the raw materials for preparing the capsule core, the mass ratio of the first fire extinguishing agent to the second fire extinguishing agent is 5:1. The other raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0063] Example 10

[0064] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that in the raw materials for preparing the capsule core, the mass ratio of the first fire extinguishing agent to the second fire extinguishing agent is 6:1. The other raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0065] Embodiment 11

[0066] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that in the process of preparing the fire extinguishing microcapsules, the step of preparing the capsule shell is omitted. In other words, the fire extinguishing microcapsules only include the capsule core and the capsule wall, and do not include the capsule shell. The rest of the raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0067] Example 12

[0068] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that in the process of preparing the fire extinguishing microcapsules, the raw materials used to prepare the capsule wall are gelatin and gum arabic, and the mass ratio of gelatin to gum arabic is 1:1; the raw material used to prepare the capsule shell is gelatin. This is equivalent to using the capsule shell of Example 1 as the capsule wall of this embodiment, and using the capsule wall of Example 1 as the capsule shell of this embodiment. The remaining raw material ratios and preparation methods are strictly consistent with those of Example 1.

[0069] Embodiment 13

[0070] This embodiment refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this embodiment and Example 1 is that urea-formaldehyde resin is selected as the resin medium during the preparation of the fire extinguishing tape. The remaining raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0071] Comparative Example 1

[0072] This comparative example refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this comparative example and Example 1 is that the first fire extinguishing agent of equal mass is used to replace the ethyl nonafluorobutyl ether used in Example 1. This is equivalent to selecting only perfluorohexanone as the capsule core. The rest of the raw material ratios and preparation methods are strictly consistent with Example 1.

[0073] Comparative Example 2

[0074] This comparative example refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this comparative example and Example 1 is that an equal mass of n-hexyl nonafluorobutyl ether is used to replace the ethyl nonafluorobutyl ether used in Example 1. The CAS number of n-hexyl nonafluorobutyl ether is 233678-10-9. The rest of the raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0075] Comparative Example 3

[0076] This comparative example refers to the method provided in Example 1 to prepare a fire extinguishing tape. The difference between this comparative example and Example 1 is that in the process of preparing the fire extinguishing microcapsules, a core-to-wall ratio of 1:1 is used. The other raw material ratios and preparation methods are strictly consistent with Example 1.

[0077] Comparative Example 4

[0078] This comparative example is used to prepare a fire extinguishing tape by referring to the method provided in Example 1. The difference between this comparative example and Example 1 is that in the process of preparing the fire extinguishing microcapsules, a core-to-wall ratio of 5:1 is used. The other raw material ratios and preparation methods are strictly consistent with those in Example 1.

[0079] Test Example 1

[0080] Test objects: fire extinguishing microcapsules and fire extinguishing tapes prepared in Examples 1 to 13; microcapsules and fire extinguishing tapes prepared in Comparative Examples 1 to 4.

[0081] Test items and test methods:

[0082] (1) Storage retention rate: The fire extinguishing microcapsules provided by each test subject were stored at 25°C for 3 months, and the content of the capsule core in the fire extinguishing microcapsules was tested by gas chromatography-mass spectrometry. Retention rate (%) = (content of capsule core in the fire extinguishing microcapsules after storage / content of capsule core in the initial fire extinguishing microcapsules) × 100%.

[0083] (2) Fire extinguishing performance: A flame of about 800°C was used as the fire source. The temperature was measured with an infrared thermometer and the fire extinguishing time was measured with a stopwatch. The fire extinguishing tape provided by each test object was fixed to the surface of the stamped steel plate with the fire extinguishing layer of the fire extinguishing tape facing downward, 1.5 cm outside the flame. The fire extinguishing time was measured and the fire extinguishing time was used to characterize the fire extinguishing performance of each test object.

[0084] Test results: Table 1 shows the raw materials used by each test object; Table 2 shows the chemical structure of the second fire extinguishing agent selected by each test object; Table 3 shows the test performance of each test object.

[0085] Table 1. Raw materials used by each test object

[0086]

[0087]

[0088] Table 2. Chemical structural formula of the second fire extinguishing agent selected in each test object

[0089]

[0090] Table 3. Test performance of each test object

[0091]

[0092]

[0093] Result analysis:

[0094] It can be seen from the test results in Table 3 that the test performance of the fire extinguishing tapes of Examples 1 to 13 is better than that of the fire extinguishing tapes of Comparative Examples 1 to 4. By comparing the raw material composition of the fire extinguishing tapes of Examples 1 to 13 and Comparative Examples 1 to 4 in Table 1, it can be found that the capsule cores prepared in Examples 1 to 13 all include a first fire extinguishing agent and a second fire extinguishing agent, and perfluorohexanone is selected as the first fire extinguishing agent, and a material satisfying general formula I is selected as the second fire extinguishing agent. General formula I is: R 1Contains less than 3 carbon atoms.

[0095] It can be seen from the chemical structure of the second fire extinguishing agent in Table 2 that the second fire extinguishing agent selected in Examples 1 to 4 satisfies the general formula I, and the n-hexyl nonafluorobutyl ether selected in Comparative Example 2 has R 1 The carbon atoms contained are 6. Comparing the test performance of Examples 1 to 4 in Table 3 with that of Comparative Example 2, it can be found that the storage retention rate of the fire extinguishing tapes of Examples 1 to 4 is better than that of the fire extinguishing tape of Comparative Example 2. It can be explained that the azeotrope composed of the second fire extinguishing agent satisfying the general formula I and the first fire extinguishing agent perfluorohexanone has a boiling point temperature between the temperatures of the first fire extinguishing agent and the second fire extinguishing agent. As a result, the fire extinguishing microcapsules can be triggered when the external ambient temperature is high, and have a lower loss rate when stored at room temperature. In the fire extinguishing tapes provided in Examples 1 to 4, the fire extinguishing performance of Examples 1 and 2 is better than that of Examples 3 to 4, which shows that when R of the general formula I is selected 1 When a methyl or ethyl compound is used as the second fire extinguishing agent, the polarity of the second fire extinguishing agent is similar to that of the first fire extinguishing agent, so that the first fire extinguishing agent and the second fire extinguishing agent have good compatibility, and the boiling point of the second fire extinguishing agent is higher than that of the first fire extinguishing agent, so that the azeotrope constituting the capsule core has a suitable boiling point, which can be quickly vaporized at high temperature to extinguish the fire, and can also reduce the amount of volatilization loss of effective fire extinguishing components under normal temperature storage. Among them, the fire extinguishing tape using ethyl nonafluorobutyl ether in Example 1 has the best fire extinguishing performance and storage retention rate.

[0096] By comparing the fire extinguishing tape provided in Example 1 with that provided in Comparative Example 1, it can be found that the fire extinguishing tape provided in Example 1 has better storage stability, which indicates that the first fire extinguishing agent and the second fire extinguishing agent are blended as the capsule core of the fire extinguishing microcapsule, and the normal temperature storage retention rate of the capsule core can be higher than the normal temperature storage retention rate of perfluorohexanone. Compared with the microcapsules in Comparative Example 1 using only the first fire extinguishing agent perfluorohexanone as the capsule core, the fire extinguishing microcapsules provided in Example 1 have a lower capsule core loss rate and good fire extinguishing performance.

[0097] By comparing Example 1, Example 5, and Example 6 with Comparative Examples 3 to 4, it can be seen that the fire extinguishing tapes provided by Example 1, Example 5, and Example 6 have better fire extinguishing performance and better storage stability. This shows that when the core-to-wall ratio is 2 to 4:1, the prepared fire extinguishing microcapsules have both good fire extinguishing performance and low loss rate, effectively improving the fire extinguishing and cooling ability of the fire extinguishing microcapsules after storage.

[0098] By comparing the fire extinguishing tapes provided in Example 1 and Examples 7 to 10, it can be found that the test performance of the fire extinguishing tapes provided in Example 1, Example 8, and Example 9 is better than that of the fire extinguishing tapes provided in Example 7 and Example 10. This shows that as the proportion of the first fire extinguishing agent in the fire extinguishing microcapsules increases, the fire extinguishing performance and storage stability of the fire extinguishing microcapsules show a trend of first increasing and then decreasing. And when the mass ratio of the first fire extinguishing agent to the second fire extinguishing agent is 3 to 5:1, the storage stability of the capsule core can be further increased, so that the fire extinguishing tape has excellent fire extinguishing performance.

[0099] In the fire extinguishing tapes of Example 1 and Examples 11-12, the storage stability of the fire extinguishing tape in Example 1 is better than that of the fire extinguishing tapes of Examples 11-12. This shows that the capsule shell is arranged on the outer side of the capsule wall in Example 1, which can further reduce the loss rate of the capsule core in the fire extinguishing microcapsule, and because the rupture temperature of the capsule shell is greater than the rupture temperature of the capsule wall, when the temperature of the external environment reaches the rupture temperature of the capsule shell, the capsule wall wrapped by the capsule shell will also rupture, and the effective fire extinguishing component as the capsule core can be released. Therefore, even if the capsule shell is arranged on the outermost side of the fire extinguishing microcapsule, it will not seriously hinder the fire extinguishing triggering of the fire extinguishing microcapsule.

[0100] By comparing the test data of Example 1 with that of Example 13, it can be seen that the use of phenolic resin and urea-formaldehyde resin as the dispersion medium can make the dispersion of the fire extinguishing microcapsules in the fire extinguishing layer good.

[0101] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A fire extinguishing microcapsule, characterized in that: The capsule comprises a capsule core, a capsule wall and a capsule shell, wherein the mass ratio of the capsule core to the capsule wall is 2:1 to 4:1, the rupture temperature of the capsule wall is greater than the boiling point of the capsule core, the capsule core comprises a first fire extinguishing agent and a second fire extinguishing agent, the first fire extinguishing agent is perfluorohexanone, and the molecular structure of the second fire extinguishing agent satisfies the general formula I: , R1 is selected from at least one of methyl, ethyl, trifluoromethyl and pentafluoroethyl; The capsule shell is wrapped outside the capsule wall, and the rupture temperature of the capsule shell is greater than the rupture temperature of the capsule wall, and the rupture temperature of the capsule shell is 120-150° C.; The capsule wall is made of gelatin, and the capsule shell is made of gelatin and gum arabic in a mass ratio of 1:

1.

2. The fire extinguishing microcapsule according to claim 1, characterized in that: R1 of the second fire extinguishing agent is selected from at least one of methyl and ethyl.

3. The fire extinguishing microcapsule according to claim 2, characterized in that: Calculated by mass, the first fire extinguishing agent: the second fire extinguishing agent = 3~5:

1.

4. The fire extinguishing microcapsule according to claim 1, characterized in that: The thickness of the capsule shell is 5-10 μm, the thickness of the capsule wall is 5-10 μm, and the average particle size D of the fire extinguishing microcapsule is 50 5~100 µm.

5. A fire extinguishing tape, characterized in that: It comprises a fire extinguishing layer, and the fire extinguishing layer comprises the fire extinguishing microcapsule according to any one of claims 1 to 4.

6. The fire extinguishing tape according to claim 5, characterized in that: The fire extinguishing layer also includes a resin medium, and the resin medium is selected from at least one of phenolic resin and urea-formaldehyde resin.

7. Use of the fire extinguishing tape as described in any one of claims 5 to 6 in the safety prevention and control of thermal runaway of power batteries.

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