A flame-retardant epoxy resin patch and its preparation method

Abstract

This application relates to the field of flame retardant technology, and particularly to a flame-retardant epoxy resin patch and its preparation method. The flame-retardant epoxy resin patch provided in this application, by weight, comprises the following raw materials: 20-60 parts epoxy resin base adhesive, 40-70 parts fire extinguishing microcapsules, 1-10 parts flame retardant, and 0.1-0.5 parts colorant; wherein the epoxy resin base adhesive is obtained by reacting bisphenol-type epoxy resin, modified epoxy resin, epoxy diluent, plasticizer, and curing agent; the shell material of the fire extinguishing microcapsules is melamine resin, and the core material is perfluorohexanone. The epoxy resin patch prepared in this application possesses both high-efficiency fire extinguishing and excellent flame-retardant properties, with a fire extinguishing capacity of more than 5 times, and no risk of secondary ignition.

Description

Technical Field

[0001] This application relates to the field of flame retardant technology, and in particular to a flame retardant epoxy resin patch and its preparation method. Background Technology

[0002] With the continuous upgrading of demand for high-performance materials in fields such as electronics, electrical engineering, transportation, and aerospace, epoxy resin has become one of the core matrix materials for high-end composite materials due to its excellent mechanical strength, bonding performance, corrosion resistance, and molding processability. However, epoxy resin has a limiting oxygen index (LOI) of less than 21% and no UL-94 flame retardant rating, making its flammable properties a serious safety hazard in fire scenarios, which greatly limits its large-scale application in key areas with high fire protection requirements. At the same time, traditional epoxy resin forms an irreversible cross-linked network after curing, which not only easily leads to drip combustion in a fire but also makes waste materials difficult to recycle, causing resource waste and environmental pollution, which contradicts the concept of circular economy development.

[0003] Fire extinguishing pads, as a convenient and efficient type of passive fire extinguishing device, are increasingly widely used in scenarios such as fire prevention in confined spaces and suppression of initial fires due to their advantages, including the elimination of complex storage devices and direct deployment to fire risk points. Currently, most mainstream fire extinguishing pads are made from flexible materials such as organosilicon as the base material, compounded with microcapsules containing fire extinguishing media such as perfluorohexanone. For example, patent CN120272136A discloses a thermally conductive fire extinguishing patch and its preparation method, which uses organosilicon resin as a base material and microcapsules to prepare the fire extinguishing patch. However, this type of substrate has significant technical shortcomings: First, the mechanical strength and temperature resistance of the silicone substrate are limited, making it prone to deformation and failure under high temperatures and complex working conditions, which makes it difficult to provide stable protection for the fire extinguishing microcapsules; Second, the self-healing properties or dense structure of some substrates can hinder the rapid triggering of the fire extinguishing microcapsules, resulting in the inability to release the fire extinguishing medium in time in the early stages of a fire, thus missing the best opportunity to extinguish the fire; Third, the flame retardant effect of existing fire extinguishing pads relies solely on the single function of the fire extinguishing microcapsules, and the substrate itself does not have flame retardant capabilities. In a fire, the combustion of the substrate will exacerbate the spread of the fire and produce toxic fumes, further aggravating the fire hazard.

[0004] Meanwhile, there are significant technological gaps in the existing systems combining fire extinguishing discs and epoxy resins: on the one hand, flame-retardant epoxy resins are mostly focused on structural reinforcement applications, and have not yet been adapted to meet the specific needs of fire extinguishing discs, such as lightweighting, flexibility, and rapid triggering; on the other hand, existing fire extinguishing disc substrates lack synergistic design with the microcapsules of the extinguishing medium, and generally suffer from common problems such as insufficient flame retardancy of the substrate, uneven microcapsule dispersion, and difficulty in balancing triggering sensitivity and storage stability. In critical scenarios such as battery compartments and electronic components, the substrate must possess the mechanical strength to meet installation requirements, while also achieving rapid response, low smoke, and low toxicity under fire conditions. Existing material systems cannot simultaneously meet these multiple performance requirements.

[0005] Furthermore, with the rapid development of emerging fields such as the low-altitude economy and new energy, more stringent requirements have been placed on the comprehensive performance of fire extinguishing materials. Materials must not only meet UL94 V-0 or higher flame retardant ratings and possess rapid fire extinguishing response capabilities, but also satisfy key indicators such as lightweight, recyclability, and low environmental impact. In existing technologies, the flame retardant modification of epoxy resin is disconnected from the structural design of the fire extinguishing pad, failing to form an integrated solution of "substrate flame retardancy - media fire extinguishing - structural adaptation." This limits the applicable scenarios for fire extinguishing pads, and the fire extinguishing efficiency and safety performance cannot meet the needs of high-end applications.

[0006] Therefore, developing a fire extinguishing plate with epoxy resin as the base material to solve the core problems of the existing technology, such as the flammability of the base material and insufficient mechanical properties, has become a technical bottleneck that urgently needs to be overcome in this field. Summary of the Invention

[0007] This application provides a flame-retardant epoxy resin patch to solve the problems of flammable substrate and insufficient mechanical properties in related technologies.

[0008] In a first aspect, this application provides a flame-retardant epoxy resin patch, comprising, by weight, the following raw materials: 20-60 parts of epoxy resin base adhesive, 40-70 parts of fire extinguishing microcapsules, 1-10 parts of flame retardant, and 0.1-0.5 parts of colorant; wherein the epoxy resin base adhesive is obtained by reacting bisphenol type epoxy resin, modified epoxy resin, epoxy diluent, plasticizer, and curing agent, and the shell material of the fire extinguishing microcapsules is melamine resin, and the core material is perfluorohexanone.

[0009] In some embodiments, the mass parts of each raw material used to prepare the epoxy resin-based adhesive are: 5-10 parts of bisphenol epoxy resin, 2-8 parts of modified epoxy resin, 1-5 parts of epoxy diluent, 1-5 parts of plasticizer, and 2-5 parts of curing agent.

[0010] In some embodiments, the bisphenol type epoxy resin is selected from any one or a mixture of bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, and hydrogenated bisphenol F type epoxy resin.

[0011] In some embodiments, the modified epoxy resin is selected from any one or a mixture of EPSI-6278, EPSI-3201, EPSI-3266, HE-184, ERS-Si1200, EPU-133L, and EPD-171.

[0012] In some embodiments, the epoxy diluent is selected from any one or a mixture of SM618, WANEPOX 828, WANEPOX 1001, and XY622.

[0013] In some embodiments, the plasticizer is selected from one or more of DBP (dibutyl phthalate), DOP (dioctyl phthalate), ESO (epoxidized soybean oil), AGE (alkyl / allyl glycidyl ether), DOS (dioctyl sebacate), TCP (tricresyl phosphate), and benzyl alcohol.

[0014] In some embodiments, the flame retardant is any one or a mixture of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, triphenyl phosphate, and tetrabromobisphenol A.

[0015] In some embodiments, the colorant is Yanbang P1829.

[0016] In some embodiments, the curing agent is selected from any one or a mixture of ethylenediamine, diethylenetriamine, triethylenetetramine, m-phenylenediamine, phenolic amine, methylhexahydrophthalic anhydride, and phthalic anhydride.

[0017] Secondly, embodiments of this application also provide a method for preparing a flame-retardant epoxy resin patch, comprising the following steps: Step S101: Mix bisphenol epoxy resin, modified epoxy resin, epoxy diluent and plasticizer, and stir at 50~100 rpm for 30~60 min to obtain the first mixture; Step S102: Add a portion of fire extinguishing microcapsules to the first mixture, stir at 10-20 rpm for 2-5 minutes, and after the mixture becomes a paste, increase the stirring speed to 50-80 rpm for 10-15 minutes to remove bubbles and obtain the second mixture; Step S103: Add flame retardant to the second mixture, stir at 10-20 rpm for 2-5 minutes, and after the mixture becomes a paste, increase the stirring speed to 50-80 rpm for 10-15 minutes to remove bubbles and obtain the third mixture; Step S104: Add the remaining fire extinguishing microcapsules to the third mixture, stir at 10-20 rpm for 2-5 minutes, and after the mixture becomes a paste, increase the stirring speed to 50-80 rpm for 10-15 minutes to remove bubbles. During stirring, turn on the vacuum pump to create a vacuum. Step S105: Add color paste and curing agent in sequence, stir at 10~20 rpm for 2~5 min, and after the color of the mixed system is uniform, increase to 50~80 rpm and stir for 10~15 min to remove bubbles. During stirring, continue to evacuate the vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressure is balanced, and then discharge the material. Step S106: The slurry is formed into a sheet by passing it through two rollers using a calender. After the epoxy resin is completely cured at room temperature, a flame-retardant epoxy resin patch is obtained.

[0018] In some embodiments, in step S102, the amount of fire extinguishing microcapsules added is 50% to 80% of the total amount of fire extinguishing microcapsules. The fire extinguishing microcapsules are added in two stages. The first stage, adding 50% to 80% of the microcapsules, can achieve uniform dispersion in a low-viscosity system, prevent agglomeration and sedimentation, and quickly build a stable paste matrix. The second stage, adding the remaining microcapsules, utilizes the low-shear environment of the paste system to protect the capsules from breakage, increase the drug loading, and ensure rapid triggering and release, achieving high integrity, high dispersibility, and high-efficiency fire extinguishing performance.

[0019] In some embodiments, the ambient temperature of the calender feeding environment is kept consistent with the temperature of the slurry, the temperature difference is controlled within 0~5℃, the height difference between the two pressure rollers is 0.05~0.3 mm, and the calendering speed is 0.5~1.5 m / min.

[0020] Conventional epoxy resins, once cured, do not possess flame-retardant properties. After the release of the fire-extinguishing microcapsules, the residual resin colloid can easily become a new ignition point under thermal conditions. Furthermore, phosphorus-modified or halogen-modified epoxy resins produce significant smoke upon heating, generating large amounts of toxic and harmful substances, which is detrimental to personnel escape and rescue in fire situations. Therefore, this application, by controlling the type of epoxy resin and the use of epoxy diluent, ensures a high addition amount of fire-extinguishing microcapsules while incorporating environmentally friendly fire-extinguishing agents. This results in residual resin colloids that not only possess excellent flame-retardant properties but also produce virtually no toxic or harmful substances.

[0021] The beneficial effects of the technical solution provided in this application include: the fire-extinguishing and flame-retardant epoxy resin patch prepared in this application can be freely cut, is easy to install, and has excellent environmental adaptability; by reasonably setting the addition amount of bisphenol epoxy resin and modified epoxy resin, the product obtained in this application has both high-efficiency fire extinguishing and excellent flame-retardant performance, and can extinguish fires more than 5 times without the risk of secondary ignition; the fire extinguishing process produces almost no toxic or harmful substances, which can maximize the safety of personnel; at the same time, the patch has outstanding weather resistance, and its performance does not significantly decrease in high and low temperature environments, and the product has rich specifications and high production flexibility, which has good practical and promotional value; this application strictly controls the temperature difference between the feeding environment and the slurry during the pressure roller process, effectively avoiding the occurrence of fire extinguishing microcapsule rupture caused by thermal shock. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a comparison of the appearance of the resin patches of Example 1 with those of Comparative Examples 2, 3, and 6. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] This application provides a flame-retardant epoxy resin patch that can solve the problems of flammable substrate and insufficient mechanical properties in the prior art.

[0026] The shell material of the fire extinguishing microcapsules used in the following examples and comparative examples is melamine resin, and the core material is perfluorohexanone. The specific preparation process of the fire extinguishing microcapsules is as follows: 20g of melamine and 50g of a 37% (w / w) formaldehyde aqueous solution were added to a three-necked flask. Triethanolamine was added dropwise to adjust the pH to 8. The mixture was heated in a water bath to 80°C and stirred for 3 hours before being discharged to obtain a colorless, clear, and transparent melamine resin prepolymer. 2.5g of styrene-maleic anhydride was added to water to prepare a 2.5% (w / w) styrene-maleic anhydride solution. Citric acid was added to adjust the pH to 4, and the temperature was maintained at 30°C. 3g of sodium perfluorononoxybenzenesulfonate was added and stirred until evenly dispersed. 80g of perfluorohexanone was added to the above emulsion and dispersed at high speed for 15 minutes to obtain a mixed emulsion. 20g of the melamine resin prepolymer was added to the mixed emulsion solution, and citric acid was added to adjust the pH to 5. The reaction was carried out for 3 hours to obtain a microcapsule emulsion. The microcapsule emulsion was sieved and dried at 45°C for 18 hours to obtain fire extinguishing microcapsules.

[0027] Example 1: (1) Weigh 7.5g EPSI-6278, 6.5g epoxy resin E44, 2.52g SM618 and 2.12g DBP, and stir at 80rpm for 40min to obtain the first mixture; (2) Weigh 36.98 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 20 rpm for 3 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 15 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 5.13 g of magnesium hydroxide and add it to the second mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 10 min and degas using a vacuum degassing machine for 60 seconds to obtain the third mixture. (4) Weigh 9.25 g of fire extinguishing microcapsules and add them to the third mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 10 min and degas using a vacuum degassing machine for 60 seconds. (5) Weigh 0.37 g of Yanbang P1829 and 2.05 g of ethylenediamine, add them to the above slurry, stir at 15 rpm for 3 min, and after the color of the mixed system is uniform, increase the stirring speed to 55 rpm for 12 min, and use a vacuum degassing machine to degas for 120 seconds. During stirring, continue to evacuate the vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressures are balanced, and then discharge the material. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the slurry does not exceed 5℃. After mixing and degassing, the slurry is calendered into sheets. After curing at room temperature for 48 hours, a fire-retardant epoxy resin patch is obtained.

[0028] Example 2: (1) Weigh 7.6 g HE-184, 5.44 g epoxy resin NPEF-170, 3.32 g XY622 and 2.72 g benzyl alcohol, stir at 60 rpm for 50 min to obtain the first mixture; (2) Weigh 36.4 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 20 rpm for 3 min. After the mixture becomes a paste, increase the stirring speed to 70 rpm for 15 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 5.13 g of magnesium hydroxide and add it to the second mixture. Stir at 20 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 12 min and degas it for 60 seconds using a vacuum degassing machine to obtain the third mixture. (4) Add 15.6 g of fire extinguishing microcapsules to the third mixture, stir at 15 rpm for 5 min, and after the mixture becomes a paste, increase the stirring speed to 60 rpm for 12 min, and use a vacuum degassing machine to degas for 60 seconds. During stirring, turn on the vacuum pump to evacuate the vacuum. (5) Weigh 0.37 g of Yanbang P1829 and 2.05 g of m-phenylenediamine, add them to the above slurry, stir at 15 rpm for 3 min, and after the color of the mixed system is uniform, increase the stirring speed to 80 rpm for 15 min, and use a vacuum degassing machine to degas for 120 seconds. During stirring, continue to draw a vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressure is balanced, and then discharge the material. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the material temperature does not exceed 5℃. After mixing and degassing, the slurry is calendered into sheets and cured at room temperature for 48 hours to obtain fire-retardant epoxy resin patches.

[0029] Example 3: (1) Weigh 6.5 g ERS-Si1200, 8.2 g epoxy resin XY518, 3.6 g WANEPOX 828, and 1.8 g AGE, stir at 60 rpm for 55 min to obtain the first mixture; (2) Weigh 30 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 15 rpm for 3 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 15 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 6.4 g of magnesium hydroxide and add it to the second mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 50 rpm for 10 min and degas it for 60 seconds using a vacuum degassing machine to obtain the third mixture. (4) Weigh 20g of fire extinguishing microcapsules and add them to the third mixture. Stir at 20rpm for 3min. After the mixture becomes a paste, increase the stirring speed to 60rpm for 15min. During stirring, turn on the vacuum pump to draw a vacuum and use a vacuum degassing machine to degas for 60 seconds. (5) Weigh 0.4 g of Yanbang P1829 and 2.4 g of methyl hexahydrophthalic anhydride, add them to the above slurry, stir at 15 rpm for 5 min, and after the color of the mixed system is uniform, increase to 80 rpm and stir for 15 min, and use a vacuum degassing machine to degas for 120 seconds. During stirring, continue to draw a vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressure is balanced, and then discharge the material. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the slurry does not exceed 5℃. After mixing and degassing, the slurry is calendered into sheets. After curing at room temperature for 48 hours, a fire-retardant epoxy resin patch is obtained.

[0030] Example 4: (1) Weigh 4.5 g EPSI-6278, 9.34 g epoxy resin E44, 3.5 g SM618 and 4.2 g DBP, stir at 80 rpm for 40 min to obtain the first mixture; (2) Weigh 44 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 15 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 5.13 g of ammonium polyphosphate and add it to the second mixture. Stir at 20 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 15 min and degas it for 60 seconds using a vacuum degassing machine to obtain the third mixture. (4) Weigh 11g of fire extinguishing microcapsules and add them to the third mixture. Stir at 20rpm for 3min. After the mixture becomes a paste, increase the stirring speed to 80rpm for 15min and degas using a vacuum degassing machine for 60 seconds. Turn on the vacuum pump to evacuate during stirring. (5) Weigh 0.5 g of Yanbang P1829 and 4.5 g of ethylenediamine, add them to the above slurry, stir at 20 rpm for 5 min, and after the color of the mixed system is uniform, increase the stirring speed to 80 rpm for 15 min, and use a vacuum degassing machine to degas for 120 seconds. During stirring, continue to draw a vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressures are balanced, and then discharge the material. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the material temperature does not exceed 5℃. After mixing and degassing, the slurry is calendered into sheets and cured at room temperature for 48 hours to obtain fire-retardant epoxy resin patches.

[0031] Example 5: (1) Weigh 7.8 g EPU-133L, 6.5 g epoxy resin YDX-7000L, 3.5 g WANEPOX 1001, and 3.5 g ESO, and stir at 100 rpm for 60 min to obtain the first mixture; (2) Weigh 48 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 20 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 15 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 2.6 g of tetrabromobisphenol A and add it to the second mixture. Stir at 10 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 15 min and degas it for 60 seconds using a vacuum degassing machine to obtain the third mixture. (4) Weigh 12 g of fire extinguishing microcapsules and add them to the third mixture. Stir at 20 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 10 min and use a vacuum degassing machine to degas for 60 seconds. Turn on the vacuum pump to evacuate during stirring. (5) Weigh 0.45g of Yanbang P1829 and 2.8g of phenolic amine, stir at 20rpm for 2min, and after the mixed system has a uniform color, increase to 80rpm and stir for 15min. Use a vacuum degassing machine to degas for 120 seconds. During stirring, continuously evacuate the vacuum. After stirring is complete, gradually reduce the speed. After stirring stops, turn off the vacuum pump and open the valve until the internal and external air pressures are balanced before discharging. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the material temperature does not exceed 5℃. The mixed and degassed slurry is calendered into sheets. After curing at room temperature for 48 hours, a fire-retardant epoxy resin sheet is obtained.

[0032] Comparative Example 1: (1) Take 7.5 g EPSI-6278, 6.5 g epoxy resin E44, 2.52 g SM618 and 2.12 g DBP, stir at 80 rpm for 40 min to obtain a mixture; (2) Weigh 0.37 g of Yanbang P1829 and 2.05 g of ethylenediamine, add them to the mixture, stir at 15 rpm for 3 min, and after the color of the mixture is uniform, increase the stirring speed to 55 rpm for 12 min, and use a vacuum degassing machine to degas for 120 seconds. During stirring, continue to evacuate the vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressures are balanced, and then discharge the material. (3) Pour the prepared slurry into the mold and cure at room temperature for 48 hours to obtain epoxy resin patch.

[0033] Comparative Example 2: (1) Weigh 7.5 g EPSI-6278, 6.5 g epoxy resin E44, 2.52 g SM618 and 2.12 g DBP, and stir at 80 rpm for 40 min to obtain the first mixture; (2) Weigh 36.98 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 20 rpm for 3 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 15 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 5.13 g of magnesium hydroxide and add it to the second mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 10 min and degas using a vacuum degassing machine for 60 seconds to obtain the third mixture. (4) Weigh 9.25 g of fire extinguishing microcapsules and add them to the third mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 10 min and degas using a vacuum degassing machine for 60 seconds. (5) Weigh 0.37 g of Yanbang P1829 and 2.05 g of ethylenediamine, add them to the above slurry, stir at 15 rpm for 3 min, and after the color of the mixed system is uniform, increase the stirring speed to 55 rpm for 12 min, and use a vacuum degassing machine to degas for 120 seconds. During stirring, continue to evacuate the vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressures are balanced, and then discharge the material. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, the calendering speed to 1 m / min, and control the temperature difference between the feeding zone and the slurry to 10 ℃. The mixed and degassed slurry is calendered into sheets. After curing at room temperature for 48 hours, a fire-retardant epoxy resin patch is obtained.

[0034] Comparative Example 3: (1) Weigh 7.5 g EPSI-6278, 6.5 g epoxy resin E44, 2.52 g SM618 and 2.12 g DBP, and stir at 80 rpm for 40 min to obtain the first mixture; (2) Weigh 36.98 g of the first mixture of fire extinguishing microcapsules, stir at 20 rpm for 3 min, and after the mixture becomes a paste, increase the stirring speed to 60 rpm for 15 min to obtain the second mixture; (3) Weigh 5.13 g of magnesium hydroxide and add it to the second mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 10 min to obtain the third mixture. (4) Weigh 9.25 g of fire extinguishing microcapsules and add them to the third mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm and stir for 10 min. (5) Weigh 0.37 g of Yanbang P1829 and 2.05 g of ethylenediamine, add them to the above slurry, stir at 15 rpm for 3 min, and after the color of the mixed system is uniform, increase to 55 rpm and stir for 12 min. During stirring, continue to draw a vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressures are balanced, and then discharge the material. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the material temperature does not exceed 5℃. Then, press the mixed slurry into sheets through the calender. After curing at room temperature for 48 hours, you will get fire-retardant epoxy resin patches.

[0035] Comparative Example 4: (1) Weigh 7.5 g EPSI-6278, 6.5 g epoxy resin E44, 2.52 g SM618 and 2.12 g DBP, and stir at 80 rpm for 40 min to obtain the first mixture; (2) Weigh 36.98 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 20 rpm for 3 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 15 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 9.25 g of fire extinguishing microcapsules and add them to the second mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 10 min and degas using a vacuum degassing machine for 60 seconds. (4) Weigh 0.37 g of Yanbang P1829 and 2.05 g of ethylenediamine, add them to the above slurry, stir at 15 rpm for 3 min, and after the color of the mixed system is uniform, increase the stirring speed to 55 rpm for 12 min, and use a vacuum degassing machine to degas for 120 seconds. During stirring, continue to evacuate the vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump, open the valve until the internal and external air pressures are balanced, and then discharge the material. (5) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the material temperature does not exceed 5℃. The mixed and degassed slurry is calendered into sheets. After curing at room temperature for 48 hours, a fire-retardant epoxy resin patch is obtained.

[0036] Comparative Example 5: (1) Weigh 10.63 g EPSI-6278, 6.75 g epoxy resin E44, 3.04 g SM618 and 2.97 g DBP, stir at 60 rpm for 50 min to obtain the first mixture; (2) Weigh 46.93 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 15 rpm for 3 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 15 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 6.51 g of magnesium hydroxide and add it to the second mixture. Stir at 20 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 12 min and degas it for 60 seconds using a vacuum degassing machine to obtain the third mixture. (4) Weigh 11.74 g of fire extinguishing microcapsules and add them to the third mixture. Stir at 15 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 12 min and use a vacuum degassing machine to degas for 60 seconds. Turn on the vacuum pump to evacuate during stirring. (5) Weigh 0.46 g of Yanbang P1829 and 2.64 g of ethylenediamine, stir at 15 rpm for 3 min, and after the mixed system has a uniform color, increase to 80 rpm and stir for 15 min. During stirring, continuously evacuate the vacuum and use a vacuum degasser for 120 seconds. After stirring is complete, gradually reduce the speed. After stirring stops, turn off the vacuum pump and open the valve until the internal and external air pressures are balanced before discharging. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the slurry does not exceed 5℃. After mixing and degassing, the slurry is calendered into sheets and cured at room temperature for 48 hours to obtain fire-retardant epoxy resin patches.

[0037] Comparative Example 6: (1) Weigh 4.88 g EPSI-6278, 12.72 g epoxy resin E44, 3.95 g SM618 and 1.94 g DBP, stir at 80 rpm for 50 min to obtain the first mixture; (2) Weigh 46.93 g of fire extinguishing microcapsules and add them to the first mixture. Stir at 15 rpm for 3 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 12 min and degas using a vacuum degassing machine for 60 seconds to obtain the second mixture. (3) Weigh 6.51 g of magnesium hydroxide and add it to the second mixture. Stir at 20 rpm for 5 min. After the mixture becomes a paste, increase the stirring speed to 80 rpm for 15 min and degas it for 60 seconds using a vacuum degassing machine to obtain the third mixture. (4) Weigh 11.74 g of fire extinguishing microcapsules and add them to the third mixture. Stir at 15 rpm for 3 min. After the mixture becomes a paste, increase the stirring speed to 60 rpm for 10 min and use a vacuum degassing machine to degas for 60 seconds. Turn on the vacuum pump to evacuate during stirring. (5) Weigh 0.46 g of Yanbang P1829 and 2.64 g of ethylenediamine, stir at 20 rpm for 5 min, and after the color of the mixed system is uniform, increase to 60 rpm and stir for 15 min. Use a vacuum degassing machine to degas for 120 seconds. During stirring, continue to evacuate the vacuum. After stirring is completed, gradually reduce the speed. After stirring stops, turn off the vacuum pump and open the valve until the internal and external air pressures are balanced before discharging. (6) Set the height of the front roller of the calender to 1.7 mm, the height of the rear roller to 1.6 mm, and the calendering speed to 1 m / min. Ensure that the temperature difference between the feeding zone and the material temperature does not exceed 5℃. After mixing and degassing, the slurry is calendered into sheets and cured at room temperature for 48 hours to obtain fire-retardant epoxy resin patches.

[0038] The epoxy resin patches prepared in Examples 1-5 and Comparative Examples 1-6 were tested to determine their fire extinguishing and flame retardant effects.

[0039] Fire extinguishing effect test: A 10 L volume distribution box was used for the test. The specific test method is as follows: First, an epoxy resin patch with adhesive backing was attached to the top of the distribution box. 3 cm of n-heptane was poured into an 8*8*5 cm crucible as an ignition source. There was a 3 cm diameter opening at each of the four corners of the back of the distribution box. The n-heptane was ignited. After 30 seconds, the distribution box door was closed. The number of times the fire was extinguished and the time required for each extinguishing were recorded.

[0040] Flame retardant effect test: The fire extinguishing and flame retardant epoxy resin patch was placed in a 150℃ oven for 1 hour. After the fire extinguishing microcapsules in the patch were completely ruptured and ineffective, the resin patch was directly ignited with a lighter and its burning state and whether there was any burning material dripping.

[0041] Table 1: Performance test results of epoxy resin patches prepared in Examples 1-5 and Comparative Examples 1-6 ; As can be seen from Table 1, the fire-extinguishing and flame-retardant epoxy resin patch provided in this application has advantages over fire extinguishing patches using other epoxy resins, such as repeated fire extinguishing, high fire extinguishing efficiency, fast response speed, safety without hidden dangers, and low toxicity and environmental friendliness. Comparative Example 1 shows that the fire-retardant epoxy resin patch prepared in this application can effectively extinguish fire sources and will not become a secondary ignition point. Comparative Example 2 shows that when the temperature difference between the feeding zone and the slurry is large during the roller pressing process, the large thermal shock will cause some fire-extinguishing microcapsules to rupture, resulting in fine pores on the surface during the curing process. At the same time, the amount of drug per unit area is reduced, which greatly reduces the fire extinguishing effect. Comparative Example 3 shows that not performing vacuum degassing will seriously affect the appearance, and the pores on the surface will affect the heat transfer, preventing the fire-extinguishing microcapsules from rupturing in a concentrated manner and failing to achieve a good fire extinguishing effect. Comparative Example 4 shows that the epoxy resin patch prepared without adding flame retardant is flammable. Comparative Example 5 shows that when the amount of bisphenol epoxy resin added is high, the prepared fire-extinguishing resin patch is flame-retardant, but the fire extinguishing effect is worse. Comparative Example 6 shows that when the amount of modified epoxy resin added is high, the prepared fire-extinguishing resin patch has no fire extinguishing effect.

[0042] Schematic diagrams of the appearance of the resin patches prepared in Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 6 are shown below. Figure 1 ,from Figure 1 As can be seen, the surface of the resin patch prepared in Example 1 is smooth and free of bubbles.

[0043] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0044] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified.

[0045] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A flame-retardant epoxy resin patch, characterized in that, The product comprises the following raw materials by weight: 20-60 parts epoxy resin base adhesive, 40-70 parts fire extinguishing microcapsules, 1-10 parts flame retardant, and 0.1-0.5 parts color paste; wherein the epoxy resin base adhesive is obtained by reacting bisphenol type epoxy resin, modified epoxy resin, epoxy diluent, plasticizer, and curing agent, and the shell material of the fire extinguishing microcapsules is melamine resin, and the core material is perfluorohexanone.

2. The flame-retardant epoxy resin patch according to claim 1, characterized in that, The mass fractions of each raw material used to prepare the epoxy resin-based adhesive are as follows: 5-10 parts of bisphenol epoxy resin, 2-8 parts of modified epoxy resin, 1-5 parts of epoxy diluent, 1-5 parts of plasticizer, and 2-5 parts of curing agent.

3. The flame-retardant epoxy resin patch according to claim 1, characterized in that, The bisphenol type epoxy resin is selected from any one or a mixture of bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, and hydrogenated bisphenol F type epoxy resin.

4. The flame-retardant epoxy resin patch according to claim 1, characterized in that, The modified epoxy resin is selected from any one or a mixture of EPSI-6278, EPSI-3201, EPSI-3266, HE-184, ERS-Si1200, EPU-133L, and EPD-171.

5. The flame-retardant epoxy resin patch according to claim 1, characterized in that, The epoxy diluent is selected from any one or a mixture of SM618, WANEPOX 828, WANEPOX 1001, and XY622.

6. The flame-retardant epoxy resin patch according to claim 1, characterized in that, The plasticizer is selected from any one or a mixture of DBP, DOP, ESO, AGE, DOS, TCP, and benzyl alcohol.

7. The flame-retardant epoxy resin patch according to claim 1, characterized in that, The curing agent is selected from any one or a mixture of ethylenediamine, diethylenetriamine, triethylenetetramine, m-phenylenediamine, phenolic amine, methylhexahydrophthalic anhydride, and phthalic anhydride.

8. The flame-retardant epoxy resin patch according to claim 1, characterized in that, The flame retardant is any one or a mixture of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, triphenyl phosphate, and tetrabromobisphenol A.

9. A method for preparing the flame-retardant epoxy resin patch according to any one of claims 1-8, characterized in that, Includes the following steps: S101, bisphenol type epoxy resin, modified epoxy resin, epoxy diluent and plasticizer are mixed and stirred to obtain the first mixture; S102, add a portion of fire extinguishing microcapsules to the first mixture, stir, and continue stirring after the mixture becomes a paste to remove bubbles and obtain the second mixture; S103, add flame retardant to the second mixture, stir, and continue stirring after the mixture becomes a paste to remove bubbles and obtain the third mixture; S104, add the remaining fire extinguishing microcapsules to the third mixture, stir, and continue stirring after the mixture becomes a paste to remove bubbles. During stirring, turn on the vacuum pump to create a vacuum. S105, add color paste and curing agent in sequence, stir, and continue stirring after the color of the mixture is uniform. Degas the mixture and continuously apply vacuum during stirring. After stirring is complete, reduce the speed and turn off the vacuum pump after stirring stops. Discharge the material. S106 is made by pressing the slurry into sheets using a calender. After the epoxy resin is fully cured at room temperature, flame-retardant epoxy resin patches are obtained.

10. The method for preparing the flame-retardant epoxy resin patch according to claim 9, characterized in that, In step S102, the amount of fire extinguishing microcapsules added is 50% to 80% of the total amount of fire extinguishing microcapsules.

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