Photo-thermal dual-curing long-acting sealing silicone rubber as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of new energy battery sealant manufacturing, and discloses photo-thermal dual-curing long-acting sealing silicone rubber as well as a preparation method and application thereof, and the preparation method comprises the following steps: S1, preparing raw materials according to a mass part ratio, including platinum catalyst slow-release microcapsules; s2, preparing a silicone rubber base material; and S3, preparing the long-acting sealing silicone rubber, wherein the two molecular groups participate in UV curing and thermocuring respectively under the action of the polymerization inhibitor. The invention also discloses the photo-thermal dual-curing long-acting sealing silicone rubber prepared by the method, and application of the silicone rubber in manufacturing of new energy batteries. The platinum catalyst sustained-release microcapsule which passively releases the catalyst to initiate the thermocuring reaction is prepared, and two-step curing is adopted, so that a structural adhesive layer respectively meets the performance requirements of a structural sealing stage and a disaster tolerance stage, and the defects that an existing sealant is long in curing time, does not have disaster tolerance performance and the like can be overcome; the method can be widely applied to manufacturing of hydrogen fuel cells or lithium batteries.

Description

Technical Field

[0001] The invention belongs to the technical field of new energy battery sealant manufacturing, and specifically relates to a staged light-heat dual-curing long-acting sealing silicone rubber, a preparation method and an application thereof. Background Art

[0002] In the sealing field of new energy batteries such as hydrogen fuel cells and ternary lithium batteries, sealant materials will be exposed to various complex working conditions inside the battery, such as acidic medium solutions, humid gases, coolants, circulating temperatures, etc., which seriously affect their service life. In the event of thermal runaway, sealant materials often fail quickly and do not have a disaster tolerance effect. The design, preparation and performance characterization of high-performance sealing materials for new energy batteries are extremely important. In order to meet the normal operation of new energy batteries, the sealing gasket (sealant layer) must meet the following performance requirements: 1. Appropriate compressibility and excellent mechanical stability; 2. Thermal, chemical and electrochemical stability, which can adapt to the complex and changeable environmental conditions and working conditions inside the battery for a long time; 3. Excellent electrical insulation, which should have good electrical insulation properties to prevent battery short circuit; 4. Low permeability, which should be able to prevent gas leakage inside the battery or external gas and moisture from invading; 5. Good economic benefits and easy processing, its low manufacturing cost and simple and fast processing technology are also crucial.

[0003] The existing new energy battery sealing materials mainly use silicone rubber and polyolefin sealants. Silicone rubber has the defects of poor air tightness, high air permeability, slow curing speed and long processing cycle, while polyolefin sealants have large shrinkage and strong water absorption, which leads to the decline of its performance in the high temperature and humid environment inside the new energy battery, affecting its long-term use effect and durability, and cannot guarantee that it can have stable and reliable high performance for a long time under different working conditions. In addition, the new energy battery sealants of the prior art cannot support UV curing and thermal curing at the same time. For example, a UV curing fuel cell bipolar plate sealant and its preparation method disclosed in CN116463082A only supports UV curing, and the UV curing time requires more than 20S, and does not support thermal curing; while the sealants that support thermal curing cannot support UV curing at the same time, and do not support UV curing and thermal curing in stages, and do not have safety and disaster tolerance performance such as passive protection, and cannot better meet the various complex requirements of new energy batteries. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, a staged photothermal dual-curing long-lasting sealing silicone rubber, a preparation method and an application thereof are provided. By synergistically improving the raw materials, preparation process and application mode, an aromatic amine inhibitor and two types of molecular groups with significantly different reactivity rates are introduced, and a unique platinum catalyst sustained-release microcapsule which passively releases the catalyst to initiate the thermal curing reaction is designed. The obtained sealing structural adhesive layer is cured in two steps, corresponding to the performance requirements of the structural sealing stage and the disaster recovery stage respectively. It can meet the comprehensive requirements of the complex and changeable working conditions of new energy batteries, durability, safety, etc., and improve the service life of new energy batteries and the disaster recovery capability of the system.

[0005] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: A method for preparing a light-heat dual-curing long-lasting sealing silicone rubber comprises the following steps: S1: Prepare the raw materials according to the following mass ratios Acrylic modified polysiloxane 50~80 Vinyl polysiloxane 20~50 Hydrogen silicone oil 8~15 Fumed silica 20~30 Catalyst sustained-release microcapsules 0.3~0.5 Initiator 1.5~3 Thickener 1~2 Aromatic amine inhibitor 0.15~0.25 Among them, the platinum catalyst sustained-release microcapsules are single-component platinum catalyst sustained-release microcapsules with an average particle size of 4-6 μm, a capsule shell formed by PP resin completely covering the spherical particles of the platinum catalyst, and a melting temperature of the capsule shell of not less than 150°C; S2: Preparation of silicone rubber base material The acrylic modified polysiloxane and the vinyl polysiloxane were sequentially added into the kneader, and the fumed silica was added in batches, and the mixture was kneaded at room temperature for 1 hour, and then vacuumed at 150°C, and kneaded for another 3 hours, and cooled to room temperature to obtain the silicone rubber base material; S3: Preparation of long-lasting sealing silicone rubber To the silicone rubber base material, hydrogen-containing silicone oil, one-component platinum catalyst sustained-release microcapsules, initiator, viscosity enhancer, aromatic amine inhibitor are added in sequence, and after stirring and mixing evenly, a long-lasting sealing silicone rubber is obtained; among them, two types of molecular groups acrylate and vinyl siloxane chain with different reactivity rates respectively participate in the first step of UV curing (mainly the double bond of the acrylate group participates in the free radical polymerization reaction of UV curing) and the second step of heating curing (vinyl siloxane chain participates in the catalyzed hydrosilylation reaction), and after step-by-step curing, structural adhesive layers with different properties are obtained accordingly.

[0006] A photothermal dual-curing long-lasting sealing silicone rubber is prepared by the aforementioned method. Under the action of an aromatic amine inhibitor, two types of molecular groups with significantly different reactivity ratios participate in the curing reaction in two steps. The first step is a UV curing reaction in which acrylate molecular groups with high reactivity ratio participate; the second step is a thermal curing hydrosilylation reaction in which vinyl siloxane molecular groups with low reactivity ratio participate when the temperature reaches above 150°C, together with the platinum catalyst passively released from a platinum catalyst sustained-release microcapsule.

[0007] An application of a photothermal dual-curing long-term sealing silicone rubber is to use the photothermal dual-curing long-term sealing silicone rubber as a structural sealant in the manufacture of hydrogen fuel cells or lithium batteries to seal the structural surface of the hydrogen fuel cell or lithium battery. After two-step curing, the structural adhesive layer successively meets different performance requirements of the structural sealing stage and the disaster recovery stage, including the following steps: A1: Apply the light-heat dual-curing long-lasting sealing silicone rubber on the sealing structure surface of the hydrogen fuel cell or lithium battery, and use UV to cure the structural adhesive layer in the first step to form a structural adhesive layer, and make its performance meet the requirements of the structural sealing stage; A2: Bond another sealing structure surface to the structural adhesive layer to form a layered sealing adhesive structure of the battery; A3: When the temperature of any sealing structure surface rises to greater than 150°C, the capsule shell of the platinum catalyst sustained-release microcapsule melts due to the heat, quickly releasing the platinum catalyst inside the microcapsule, and undergoing a thermal curing reaction with the vinyl siloxane molecular groups, so that the sealing structure adhesive layer is thermally cured, and the mechanical properties, heat resistance and flame retardancy of the sealing structure adhesive layer are rapidly increased, so that it meets the performance requirements of the disaster recovery stage, thereby combining with other safety measures to enhance the overall disaster recovery performance of the battery system, delay thermal runaway, and improve the system safety of the battery system.

[0008] The staged light-heat dual-curing long-lasting sealing silicone rubber, preparation method and application thereof provided by the present invention have at least the following beneficial effects: 1. The present invention, through the coordinated improvement of the raw materials, preparation process and application mode of sealing silicone rubber (referred to as sealant), introduces aromatic amine inhibitors and two types of molecular groups with significantly different activities under UV conditions, designs unique platinum catalyst sustained-release microcapsules that passively release catalysts to trigger thermal curing reactions, and carries out photothermal dual curing in two independent stages, so that the obtained sealing structural adhesive layer is cured in two steps, corresponding to the performance requirements of the structural sealing stage and the disaster tolerance stage respectively, and can meet the comprehensive requirements of new energy batteries such as complex and changeable working conditions, durability, safety, etc., and improve the service life and disaster tolerance capability of new energy batteries.

[0009] 2. The present invention introduces an inhibitor, which forms two types of molecular groups with significantly different reactivity ratios (UV curing activity), which respectively support UV curing (ultraviolet curing) and passive thermal curing above 150°C. The inhibitor significantly reduces the activity of vinyl siloxane under UV conditions, so that the two types of molecular groups with different reactivity ratios successively and mainly participate in only one stage of the curing reaction to obtain a structural adhesive layer with different performance advantages. The sealing structural adhesive layer of the battery formed after the first stage of UV curing (mainly acrylate molecular groups) in the factory can fully meet the bonding and sealing requirements of the battery. After the first step of UV curing, the proportion of acrylate segments reaches a peak. At this time, the sealing structural adhesive layer has the best air-proof and water-vapor-proof properties. If thermal curing is continued to make the structural adhesive layer completely cured, the polysiloxane segments added after thermal curing will cause the mechanical strength and flame retardant properties of the structural adhesive layer to increase, while the air-proof and water-vapor-proof properties will decrease, which is not conducive to the normal operation of the battery. Under the action of aromatic amine inhibitors, the activity of vinyl siloxane molecular groups in UV photocuring reaction is very low. Compared with acrylate molecular groups, the reactivity rate of vinyl siloxane molecular groups is very low, less than 0.01. Therefore, in a short time of less than 10 seconds and in the UV curing reaction when the acrylate molecular groups are not completely reacted, most of the vinyl siloxane molecular groups do not participate in the UV curing reaction.

[0010] 3. The present invention prepares catalyst sustained-release microcapsules with specific shapes, structures, sizes and rupture temperatures, and seals the catalyst in the capsules so that they do not come into contact with other components. Only when the temperature of the battery system reaches 150°C, the capsule wall shell ruptures, passively and quickly releasing the catalyst to initiate a thermal curing reaction (photothermal dual curing). When the temperature does not reach 150°C, the microcapsules maintain their shape intact, do not affect the UV curing reaction, do not release the catalyst, and do not initiate a thermal curing reaction, thereby maintaining a high level of air and water vapor resistance of the structural adhesive layer after one-step curing. Only when the temperature of the battery system rises to 150°C or above and is in a dangerous operating condition, the catalyst is passively released to initiate a thermal curing reaction, thereby quickly improving the high temperature resistance, mechanical strength, flame retardancy and other disaster tolerance properties of the structural adhesive layer, and coordinating with other safety measures to improve the overall safety of the battery system.

[0011] 4. The present invention designs and prepares highly stable catalyst sustained-release microcapsules, and uses PP resin with a high softening point and a high melting temperature to encapsulate the platinum catalyst, so that the catalyst is completely isolated from other active components. The obtained sealing silicone rubber product can be stored at room temperature (below 25°C) for more than 6 months without performance degradation, making it suitable for long-term storage and transportation, and also overcoming the short shelf life of existing similar products.

[0012] 5. The present invention applies the above-mentioned specially prepared photothermal dual-curing long-lasting sealing silicone rubber with special properties as a structural sealant to the manufacture of hydrogen fuel cells or lithium batteries, and is used to seal the structural surface of hydrogen fuel cells or lithium batteries. After two-stage curing, the structural adhesive layer successively reaches the performance requirements of the structural sealing stage and the disaster recovery stage, that is, it can meet the long-term operating performance requirements of normal working conditions, and can also meet the rapid disaster recovery performance requirements of crisis conditions, breaking through the limitations of existing similar products.

[0013] 6. The preparation method and application of the sealing silicone rubber provided by the present invention have a simple process and a short UV curing time, and can be widely applied to the CIPG (cured in place gasket) process in the production process of new energy batteries. This process is to apply the sealant on the sealing surface and cure it before assembly to achieve single-sided bonding. The conventional silicone rubber curing time is more than 20 minutes, while the first step of UV curing of the present invention can be completed within 10 seconds, and the second step of thermal curing is automatically triggered according to the temperature of the battery and does not take up production time. Since the curing speed of the sealant determines the assembly efficiency of the battery, the present invention realizes UV and thermal dual curing of the support sealant by encapsulating and isolating the acrylic modified silicone and the catalyst. Only UV curing is required in the factory assembly stage, which greatly shortens the assembly processing time, improves assembly efficiency, and reduces production costs. DETAILED DESCRIPTION

[0014] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solution 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 are within the scope of protection of the present invention.

[0015] Basic Example

[0016] The method for preparing the light-thermal dual-curing long-lasting sealing silicone rubber provided in this embodiment comprises the following steps: S1: Prepare the raw materials according to the following mass ratios Acrylic modified polysiloxane 50~80 Vinyl polysiloxane 20~50 Hydrogen silicone oil 8~15 Fumed silica 20~30 Catalyst sustained-release microcapsules 0.3~0.5 Initiator 1.5~3 Thickener 1~2 Aromatic amine inhibitor 0.15~0.25 Among them, the platinum catalyst sustained-release microcapsules are single-component platinum catalyst sustained-release microcapsules with an average particle size of 4-6 μm, a capsule shell formed by PP resin completely covering the spherical particles of the platinum catalyst, and a melting temperature of the capsule shell of not less than 150°C; The step S1-1 of first preparing platinum catalyst sustained-release microcapsules comprises: S1-1-1: Add platinum catalyst and PP resin (melting point greater than 150°C, such as K9927) to D80 solvent oil at a mass ratio of 1.5-2:1, raise the temperature to 60-70°C, stir and dissolve, control the stirring speed to 300-500rpm, and keep stirring for 2-3h; by controlling the ratio of platinum catalyst and PP resin and the stirring speed, the obtained capsule wall shell thickness is 2-3μm; S1-1-2: Then the mixed solution is added dropwise to the polypropylene alcohol aqueous solution, and after the addition, it is stirred at room temperature, and the stirring speed is controlled to be 500-600 rpm for 6-8 hours to obtain spheres with an average particle size of 4-6 μm; The particle size, overall shape and surface roughness of the capsule are mainly controlled by step S1-1-2. The faster the stirring speed, the finer the particle size, the longer the reaction time, the closer the overall shape is to a sphere, and the smoother the surface morphology. S1-1-3: The solvent is removed by distillation under reduced pressure to obtain spherical single-component platinum catalyst sustained-release microcapsules with a capsule wall thickness of 2-3 μm and an average particle size of 4-6 μm; the platinum catalyst sustained-release microcapsules remain stable within 150°C and do not release catalyst; when the temperature reaches 150°C or above, the capsule wall shell melts and can quickly release the catalyst activity to participate in the thermal curing reaction.

[0017] If the particle size of the prepared catalyst sustained-release microcapsules is too large, the number of microcapsules in the structural adhesive layer system will be too small, and the morphological integrity will be difficult to maintain during the working process and will be easily squeezed and broken by the system, affecting the stability of the structural adhesive layer; if the particle size of the microcapsules is too small, the number of microcapsules will be too large, the thickness of the capsule wall shell will be too thin, the integrity of the microcapsule morphology will not be easy to maintain, and the activity may be released at normal temperature, which will also affect the stability of the capsule catalyst; the capsule wall material selected for the microcapsule is PP resin with a melting point of 150°C or above. The physical and chemical properties of PP resin are stable. After mixing with polysiloxane substances at room temperature, it can maintain good chemical and physical inertness. When heated to a temperature above the softening point of PP resin about 145°C, the capsule wall shell of the microcapsule softens; when the temperature reaches 150°C or above, the capsule wall shell melts and quickly releases the catalyst inside, triggering the second step of thermal curing reaction.

[0018] The catalyst sustained-release microcapsules prepared in the embodiment of the present invention are spherical with a particle size of 4-6 μm, a capsule wall shell thickness of 2-3 μm, and a rough outer surface. The particle size and capsule wall shell thickness are moderate, the morphology is regular, and the room temperature stability is good. When heated to above 150° C., the active catalyst can be quickly released to trigger a secondary thermal curing reaction, thereby greatly improving the comprehensive disaster tolerance performance of the structural adhesive layer material.

[0019] The PP resin used in this embodiment is a PP resin with a melting point greater than 150°C, including homopolymer grade PP (PP-H) or copolymer grade PP (PP-R). Specific models may be K9927, EP300M, etc. Of course, other PP resin products with a melting point greater than 150°C may also be used.

[0020] The platinum catalyst is a Karstedt platinum catalyst.

[0021] The step S1-2 of preparing acrylic modified polysiloxane comprises: S1-2-1: 1000 parts by weight of octamethylcyclotetrasiloxane, 2 to 5 parts by weight of tetramethyldivinyldisiloxane, and 200 to 350 parts by weight of hydroxy acrylate were respectively added to a reaction kettle; S1-2-2: Raise the temperature to 90-110°C while stirring at a stirring speed of 700-800 rpm; then add 1-3 parts by weight of tetramethylammonium hydroxide, continue stirring at a speed of 500-600 rpm, and perform polymerization reaction for 5 hours; after the polymerization reaction, compared with the carboxylic acid structure of acrylic modified polysiloxane and the silicon oxygen chain structure of silicone, the carbon-carbon molecular chain has a shorter intermolecular distance and a smaller free volume, which can provide higher gas leakage resistance and lower moisture permeability; S1-2-3: The catalyst and small molecules are then removed at 150~170℃ and 0.1MPa negative pressure to obtain acrylic modified polysiloxane; after the polymerization reaction, acrylate groups are introduced, and the carbon-carbon molecular chain has a shorter intermolecular distance and a smaller free volume, which has two functions: one is to provide higher gas leak-proof performance and lower moisture permeability, and the other is to support UV curing.

[0022] S2: Preparation of silicone rubber base material The acrylic modified polysiloxane and the vinyl polysiloxane were sequentially added into the kneader, and the fumed silica was added in batches, and the mixture was kneaded at room temperature for 1 hour, and then vacuumed at 150°C, and kneaded for another 3 hours, and cooled to room temperature to obtain the silicone rubber base material; S2-1: First, add acrylic modified polysiloxane and vinyl polysiloxane into a kneader in sequence; S2-2: Add fumed silica in batches and knead at room temperature for 1 hour; S2-3: Then, vacuum kneading was performed at 150° C. for 3 h, and the mixture was cooled to room temperature to obtain a silicone rubber base material.

[0023] S3: Preparation of long-lasting sealing silicone rubber To the silicone rubber base material, hydrogen-containing silicone oil, one-component platinum catalyst sustained-release microcapsules, initiator, viscosity enhancer, aromatic amine inhibitor are added in sequence, and after stirring and mixing evenly, a long-lasting sealing silicone rubber is obtained; among them, two types of molecular groups acrylate and vinyl siloxane with different reactivity rates respectively participate in the first step of UV curing (the double bonds of the acrylate group with high reactivity rate undergo free radical polymerization reaction until complete reaction) and the second step of heating curing (the vinyl siloxane with low reactivity rate participates in catalyzed silylation reaction), and after step-by-step curing, structural adhesive layers with different properties are obtained accordingly. That is, when the sealant coating prepared from long-lasting sealing silicone rubber is cured in two stages, a part of the high-reactivity groups (acrylates) only participate in the first-stage UV curing (factory assembly stage) and are completely consumed after the first UV curing reaction; while the other part of the low-reactivity groups (vinyl siloxanes) protected by the inhibitor, at this time, the activity of the vinyl siloxane groups in the UV light curing reaction is very low, and the reactivity of the vinyl siloxane groups is very low compared with the acrylate groups, less than 0.01. Therefore, in the short time of less than 10s and the first UV curing reaction when the acrylate groups are not completely reacted, most of the vinyl siloxane groups do not participate in the UV curing reaction. This part of the vinyl siloxane groups and the platinum catalyst in the sustained-release microcapsules only participate in the second-stage heating curing at a temperature above 150°C (passively triggered after leaving the factory).

[0024] S3-1: Add hydrogen-containing silicone oil, platinum catalyst slow-release microcapsules, initiator, tackifier, and aromatic amine polymerization inhibitor to the silicone rubber base material in proportion; the aromatic amine polymerization inhibitor is diphenylamine or N-nitrosodiphenylamine; S3-2: Mix in a mixer at room temperature to obtain long-lasting sealing silicone rubber (sealant for short).

[0025] A photothermal dual-curing long-lasting sealing silicone rubber is prepared by the aforementioned method, wherein two types of molecular groups with significantly different reactivity rates participate in the curing reaction in two steps respectively, the first step is mainly a UV curing reaction involving acrylate molecular groups; the second step is mainly a thermal curing hydrosilylation reaction involving vinyl siloxane molecular groups when the temperature reaches above 150°C, together with the platinum catalyst passively released from the platinum catalyst sustained-release microcapsule.

[0026] More specifically, due to the effect of aromatic amine inhibitors, in the first step of UV curing, one type of molecular groups with high reactivity rate (acrylate) participates in UV curing, while another type of molecular groups with low reactivity rate (vinyl siloxane) and platinum catalyst mostly do not participate in the reaction. The specific principle is: due to the protection of aromatic amine inhibitors, the activity of vinyl siloxane groups under UV light curing conditions is very low. Compared with acrylate groups, the reactivity rate of vinyl siloxane groups is very low, less than 0.01. In a limited UV curing time (e.g. within 10s) and with acrylic acid, In the presence of acid ester groups, most of the vinyl siloxane groups do not participate in the UV curing reaction; after UV curing, the proportion of acrylate segments in the structural adhesive layer reaches a peak, so that the structural adhesive layer has the best air permeability and water vapor resistance; when the temperature reaches above 150°C, most of the other type of vinyl siloxane molecular groups are thermally cured together with the platinum catalyst passively released after the capsule wall shell of the platinum catalyst sustained-release microcapsule is melted; during the thermal curing process, the mechanical strength, heat resistance and flame retardancy of the structural adhesive layer can be rapidly increased through addition reactions.

[0027] After the first step of UV curing, the obtained sealing structure adhesive layer can fully meet the bonding and sealing requirements of the battery. After the first step of UV curing, the proportion of acrylate segments reaches a peak. At this time, the sealing structure adhesive layer achieves the best anti-air permeability and water vapor resistance effect. If it is fully cured from the beginning (continue to complete thermal curing), the polysiloxane segments added after silylation will cause the anti-air permeability and water vapor resistance of the sealing structure adhesive layer to decrease.

[0028] When the battery reaches the limit temperature of thermal runaway of 150°C, the cohesive strength and bonding strength of the sealing structure adhesive layer can quickly increase by 30% to 50%; at the same time, the released platinum catalyst also increases the flame retardant effect of the sealing structure adhesive layer, and the flame retardant level is increased from V1 to V0; the temperature resistance of the sealing structure adhesive layer is increased from 160°C to above 220°C; the long-lasting sealing silicone rubber provided in this embodiment can simultaneously support light and thermal dual curing (UV, thermal curing), wherein the second step of thermal curing is passive curing when the battery system temperature reaches 150°C, so as to improve the overall safety of the battery system, and does not react under normal operating conditions of the battery system (system temperature below 120°C), and is in a silent state, which is a safety redundant design.

[0029] The aromatic amine polymerization inhibitor selected in the embodiment of the present invention is specifically diphenylamine or N-nitrosodiphenylamine, which has a weak polymerization inhibition effect and only has a polymerization inhibition effect on vinyl siloxane under UV conditions, but has no polymerization inhibition effect on acrylate. Due to the polymerization inhibition effect of the aromatic amine polymerization inhibitor, during the photocuring process, most of the vinyl siloxane groups can be protected and no free radical polymerization occurs, while the free radical polymerization reaction of the acrylate group is not affected, so that most of the vinyl siloxane groups can participate in the second stage of thermal curing reaction.

[0030] This embodiment introduces acrylic modified silicone to achieve dual curing of the sealant by UV and heat, and enables the sealant to be UV cured within 10 seconds, which greatly shortens the processing time and improves the assembly efficiency of the battery.

[0031] An application of a light-heat dual-curing long-lasting sealing silicone rubber is used as a structural sealant in the manufacture of hydrogen fuel cells or lithium batteries to seal the structural surface of hydrogen fuel cells or lithium batteries. It is cured in two steps to make the structural adhesive layer meet different performance requirements of the structural sealing stage and the disaster recovery stage respectively. It includes the following steps: A1: Apply the light-heat dual-curing long-lasting sealing silicone rubber on the sealing structure surface of the hydrogen fuel cell or lithium battery, and use UV to cure the structural adhesive layer in the first step to form a structural adhesive layer, and make its performance meet the requirements of the structural sealing stage; A2: Bond another sealing structure surface to the structural adhesive layer to form a layered sealing adhesive structure of the battery; A3: When the temperature of any sealing structure surface rises to greater than 150°C, the capsule shell of the platinum catalyst sustained-release microcapsule melts due to the heat, quickly releasing the liquid platinum catalyst inside the microcapsule, and undergoing a thermal curing reaction with the vinyl siloxane molecular groups, so that the sealing structure adhesive layer is thermally cured, and the mechanical properties, heat resistance and flame retardancy of the sealing structure adhesive layer are rapidly increased, so that it meets the performance requirements of the disaster recovery stage, thereby combining with other safety measures to enhance the overall disaster recovery performance of the battery system, delay thermal runaway, and improve the safety of the battery system.

[0032] The following is a detailed description with reference to a number of specific embodiments.

[0033] Example 1

[0034] The photothermal dual-curing long-term sealing silicone rubber (sealant for short), preparation method and application thereof provided in this embodiment are specific selections based on the aforementioned basic embodiment. The difference between the photothermal dual-curing long-term sealing silicone rubber and the basic embodiment is that the preparation method of the photothermal dual-curing long-term sealing silicone rubber is specifically as follows: First, 60 parts of acrylic modified polysiloxane, 40 parts of 50000mm 2 / s vinyl polysiloxane is added to a kneader, and then 20 parts of fumed silica are added in batches, kneaded at room temperature for 1 hour, and then vacuum kneaded at 150°C for 3 hours, cooled to room temperature to obtain a basic rubber compound; then 12 parts of 1.0% hydrogen-containing silicone oil, 0.4 parts of a single-component platinum catalyst, 2 parts of 1-hydroxycyclohexyl phenyl ketone (photoinitiator), 1.5 parts of γ-glycidyloxypropyltrimethoxysilane (tackifier), and 0.15 parts of diphenylamine are added, and mixed in a mixer at room temperature to obtain a light-thermal dual-curing long-lasting sealing silicone rubber.

[0035] The step S1-1 of first preparing platinum catalyst sustained-release microcapsules is as follows: Karstedt platinum catalyst and PP resin K9927 are added to D80 solvent oil in a mass ratio of 1:1, the temperature is raised to 60-70°C, and the mixture is stirred and dissolved to obtain a mixed solution, and then the mixed solution is added dropwise to the polypropylene alcohol aqueous solution, and the reaction is stirred at room temperature for 8 hours after the addition is completed, and the solvent is removed by reduced pressure distillation to obtain platinum catalyst sustained-release microcapsules (microcapsule encapsulated catalyst); wherein the mass ratio of the mixed solution to the polypropylene alcohol aqueous solution is 2:1. The melting point of the PP resin K9927 used in this embodiment is about 160°C. This melting point temperature can ensure that the prepared platinum catalyst sustained-release microcapsules will not melt during subsequent processing procedures, assembly, and normal operation, and can ensure the integrity of the microcapsule appearance structure and isolate the catalyst from other components.

[0036] In this embodiment, the thickness of the capsule wall can be obtained at 2~3μm by controlling the ratio of platinum catalyst and PP resin; the stirring speed and reaction time affect the particle size and surface morphology of the capsule. By controlling the stirring speed at 500~600rpm and the reaction time at 6~8h, spherical microcapsules with an average particle size of 4~6μm can be obtained. If the particle size of the prepared microcapsules is too large, they are easily damaged by pressure during the subsequent assembly and use process, and the morphological integrity of the microcapsules will be difficult to maintain, affecting the stability of the microcapsules; and if the particle size of the microcapsules is too small, the capsule wall thickness is too thin and it is also easy to break, which also affects the integrity of the shape of the microcapsules. The wall material selected for the microcapsules is a high-melting-point PP resin. The PP resin has stable physical and chemical properties. After mixing with polysiloxane substances at room temperature, it can maintain good chemical and physical inertness. Only when the temperature reaches the melting point of the capsule wall material PP resin above 160°C, the activity of the microcapsules can be quickly released. The spherical microcapsules finally prepared in this embodiment have a particle size of 4-6 μm and a thickness of 2-3 μm. The particle size is moderate, the shape is regular, and the stability at room temperature is good. Only when heated to above 160° C. can the activity be quickly released to participate in the reaction, and when the temperature is below 160° C., the shape can always be kept intact.

[0037] The aforementioned application of the light-heat dual-curing long-lasting sealing silicone rubber is to use it as a structural sealant in the manufacture of hydrogen fuel cells (the normal operating temperature is between 60°C and 120°C) or lithium batteries (the normal operating temperature of the ternary lithium battery system is between -20°C and 60°C). It is used to seal the structural surface of hydrogen fuel cells or lithium batteries. It is cured in two steps to make the structural adhesive layer meet the different performance requirements of the structural sealing stage and the disaster recovery stage respectively. It includes the following steps: A1: Apply the light-thermal dual-curing long-lasting sealing silicone rubber on the sealing structure surface of the hydrogen fuel cell or lithium battery, and use a UV light source to irradiate for 8s to cure the structural adhesive layer in the first step to form a structural adhesive layer, and make its performance meet the requirements of the structural sealing stage (high sealing performance); A2: Bond another sealing structure surface to the structural adhesive layer to form a layered sealing adhesive structure of the battery; A3: When the temperature of any sealing structure surface of the battery system rises to greater than 150°C, the capsule shell of the platinum catalyst sustained-release microcapsule melts due to the heat, quickly releasing the liquid platinum catalyst inside the microcapsule, and undergoing a thermal curing reaction with the vinyl siloxane molecular groups, so that the sealing structure adhesive layer is thermally cured, and the mechanical properties, heat resistance and flame retardancy of the sealing structure adhesive layer are rapidly increased, so that it meets the performance requirements of the disaster recovery stage (high safety), thereby combining with other safety measures to enhance the overall disaster recovery performance of the battery system, delay thermal runaway, and improve the overall safety of the battery system.

[0038] Example 2

[0039] The photothermal dual-curing long-term sealing silicone rubber, preparation method and application thereof provided in this embodiment are specific selections based on the aforementioned basic embodiment and embodiment 1. The difference between the basic embodiment and embodiment 1 is that the preparation method of the photothermal dual-curing long-term sealing silicone rubber is specifically as follows: 50 parts of acrylic modified polysiloxane, 50 parts of 50000mm 2 / s vinyl polysiloxane is added to a kneader, and 25 parts of fumed silica are added in batches. The mixture is kneaded at room temperature for 1 hour, and then vacuum kneaded at 150°C for 3 hours. The mixture is cooled to room temperature to obtain a basic rubber compound. Then, 15 parts of 1.0% hydrogenated silicone oil, 0.5 parts of a single-component platinum catalyst, 1.5 parts of 1-hydroxycyclohexyl phenyl ketone, 1.5 parts of γ-glycidyloxypropyltrimethoxysilane and 0.2 parts of diphenylamine are added. The mixture is mixed in a mixer at room temperature to obtain a light-thermal dual-curing long-lasting sealing silicone rubber.

[0040] The PP resin used in this embodiment is a PP resin with a melting point greater than 160°C, specifically EP300M, and its melting point is about 160°C to 170°C.

[0041] The step S1-1 of first preparing platinum catalyst sustained-release microcapsules is as follows: Karstedt platinum catalyst and PP resin EP300M are added to D80 solvent oil in a ratio of 1:1, the temperature is raised to 60-70°C, and the mixture is stirred to dissolve to obtain a mixed solution, and then the mixed solution is added dropwise to the polypropylene alcohol aqueous solution. After the addition, the mixture is stirred at room temperature for 8 hours, and the solvent is removed by distillation under reduced pressure to obtain platinum catalyst sustained-release microcapsules (microcapsule encapsulated catalyst); the mass ratio of the mixed solution to the polypropylene alcohol aqueous solution is 2:1.

[0042] The spherical microcapsules prepared by the invention have a particle size of 4-6 μm and a capsule wall shell thickness of 2-3 μm. The particle size and capsule wall shell thickness are both moderate, the morphology is regular, and the room temperature stability is good. When heated to above 160° C., the active catalyst can be quickly released to initiate the second step of thermal curing reaction.

[0043] Example 3

[0044] The photothermal dual-curing long-term sealing silicone rubber, preparation method and application thereof provided in this embodiment are specific selections based on the aforementioned basic embodiment and embodiment 1. The difference between the basic embodiment and embodiment 1 is that the preparation method of the photothermal dual-curing long-term sealing silicone rubber is specifically as follows: 65 parts of acrylic modified polysiloxane, 35 parts of 50000mm 2 / s vinyl polysiloxane is added to a kneader, and 25 parts of fumed silica are added in batches. The mixture is kneaded at room temperature for 1 hour, and then vacuum kneaded at 150°C for 3 hours. The mixture is cooled to room temperature to obtain a basic rubber compound. Then, 11.5 parts of 1.0% hydrogenated silicone oil, 0.4 parts of a single-component platinum catalyst, 2.5 parts of 1-hydroxycyclohexyl phenyl ketone, 1 part of γ-glycidyloxypropyltrimethoxysilane and 0.25 parts of N-nitrosodiphenylamine are added. The mixture is mixed in a mixer at room temperature to obtain a light-thermal dual-curing long-lasting sealing silicone rubber.

[0045] The step S1-1 of first preparing platinum catalyst sustained-release microcapsules is as follows: Karstedt platinum catalyst and PP resin are added to D80 solvent oil in a mass ratio of 1.5:1, the temperature is raised to 60-70°C, and the mixture is stirred and dissolved to obtain a mixed solution, which is then added dropwise to a polypropylene alcohol aqueous solution. After the addition, the mixture is stirred and reacted at room temperature for 8 hours, and the solvent is removed by reduced pressure distillation to obtain platinum catalyst sustained-release microcapsules; wherein the mass ratio of the mixed solution to the polypropylene alcohol aqueous solution is 2.3:1.

[0046] The PP resin used in this embodiment is LG SEETEC PP H1315, a PP resin with a melting point greater than 150°C. In other embodiments, it can also be selected from homopolymer grade PP (PP-H) or copolymer grade PP (PP-R), specifically according to the requirements of the battery thermal runaway safety trigger temperature.

[0047] Example 4

[0048] The photothermal dual-curing long-term sealing silicone rubber, preparation method and application thereof provided in this embodiment are specific selections based on the aforementioned basic embodiment and embodiment 1. The difference between the basic embodiment and embodiment 1 is that the preparation method of the photothermal dual-curing long-term sealing silicone rubber is specifically as follows: 80 parts of acrylic modified polysiloxane, 20 parts of 50000mm 2 / s vinyl polysiloxane is added to a kneader, and 30 parts of fumed silica are added in batches. The mixture is kneaded at room temperature for 1 hour, and then vacuum kneaded at 150°C for 3 hours. The mixture is cooled to room temperature to obtain a basic rubber compound. Then, 8 parts of 1.0% hydrogen-containing silicone oil, 0.3 parts of a single-component platinum catalyst, 3 parts of 1-hydroxycyclohexyl phenyl ketone, 2 parts of γ-glycidyloxypropyltrimethoxysilane and 0.2 parts of N-nitrosodiphenylamine are added. The mixture is mixed in a mixer at room temperature to obtain a light-thermal dual-curing long-lasting sealing silicone rubber.

[0049] The PP resin used in this embodiment is RP340P resin, which has a melting point of about 160°C.

[0050] The step S1-1 of first preparing platinum catalyst sustained-release microcapsules is as follows: Karstedt platinum catalyst and PP resin are added to D80 solvent oil in a ratio of 1.25:1, the temperature is raised to 60-70°C, and the mixture is stirred to dissolve to obtain a mixed solution, which is then added dropwise to the polypropylene alcohol aqueous solution. After the addition, the mixture is stirred at room temperature for 8 hours, and the solvent is removed by distillation under reduced pressure to obtain platinum catalyst sustained-release microcapsules; wherein the mass ratio of the mixed solution to the polypropylene alcohol aqueous solution is 2.2:1.

[0051] Comparative Example The photothermal dual-curing long-term sealing silicone rubber and the preparation method thereof provided in this embodiment are substantially the same as those in Example 1, except that a catalyst that is not encapsulated by microencapsulation is directly used, which cannot support photothermal curing in two stages and can only be cured directly during factory assembly, does not have disaster tolerance characteristics, and has a relatively short shelf life. The preparation method of the photothermal dual-curing long-term sealing silicone rubber is specifically as follows: 100 pieces of 50000mm 2 / s vinyl polysiloxane is added to a kneader, and 25 parts of fumed silica are added in batches, kneaded at room temperature for 1 hour, and then vacuum kneaded at 150°C for 3 hours, cooled to room temperature to obtain a basic rubber material, and then 13.5 parts of 1.0% hydrogen-containing silicone oil, 0.4 parts of a one-component liquid platinum catalyst (free state, not microencapsulated), 2 parts of 1-hydroxycyclohexyl phenyl ketone, and 1.5 parts of γ-glycidyloxypropyltrimethoxysilane are added, and mixed in a mixer at room temperature to obtain a sealing silicone rubber.

[0052] The structural adhesive layer of the sealing silicone rubber prepared in the above embodiments after two-step curing was tested, and the main physical and chemical properties and index parameters obtained are shown in Table 1 (performance after UV curing in the first stage) and Table 2 (performance after heating curing in the second stage).

[0053] Table 1

[0054] Table 2

[0055] As can be seen from Table 1 and Table 2, the above-mentioned Examples 1-4 of the present invention prepare catalyst slow-release microcapsules of specific shape, structure, size and melting temperature, isolate the catalyst from other components, enable UV curing and thermal curing to be carried out in stages, and obtain two structural adhesive layers with different advantages and performances to meet the requirements of manufacturing, use, safety, etc. of the battery system. When the battery system reaches a dangerous operating temperature of 150°C or above, the capsule wall shell of the catalyst slow-release microcapsule is passively melted, quickly releasing the catalyst, triggering the second stage of thermal curing reaction, quickly increasing the main disaster tolerance performance of the structural adhesive layer, and cooperating with other measures to improve the overall safety of the battery system.

[0056] In the above embodiments, only the first stage of UV curing is required during factory assembly so that the obtained structural adhesive layer maintains high sealing performance to meet the requirements of battery manufacturing and normal operation, and the second stage of passive thermal curing is used as safety redundancy, with 150°C as the safety critical temperature. When this temperature is reached or exceeded, thermal curing is passively initiated; the thermal curing reaction quickly enhances the disaster tolerance performance of the structural adhesive layer, such as high temperature resistance, mechanical strength, and flame retardancy, while sacrificing a part of the sealing performance (the air permeability of the structural adhesive layer after thermal curing is significantly increased) to delay catastrophic conditions such as thermal runaway and improve the overall safety of the battery system.

[0057] The above embodiments of the present invention, on the one hand, improve the defect that ordinary silicone rubber has high air permeability but does not meet the sealing requirements for highly permeable gases such as hydrogen, oxygen, and water vapor by introducing acrylic modified polysiloxane, thereby significantly reducing the air permeability and moisture permeability of the structural adhesive layer after UV curing; compared with the carboxylic acid structure of acrylic modified polysiloxane and the silicon-oxygen chain structure of silicone, the carbon-carbon molecular chain has a shorter intermolecular distance and a smaller free volume, which can provide higher gas leakage prevention performance and lower moisture permeability; on the other hand, through the specially prepared catalyst sustained-release microcapsules, the thermal curing reaction is passively initiated to improve the safety performance of the structural adhesive layer.

[0058] The light-heat dual-curing long-lasting sealing silicone rubber provided in the above-mentioned embodiment of the present invention has also been collaboratively improved for the situation where the hydrogen fuel cell sealant construction process mainly adopts ‌CIPG (cured in place gasket). The ‌CIPG process is to apply the sealant to the sealing surface and solidify it before assembly to achieve single-sided bonding. The conventional silicone rubber curing time is more than 20 minutes (the patented technology in the background technology uses UV light curing for 20 seconds); since the curing speed of the sealant determines the assembly efficiency of the battery module at the factory stage, therefore. The present invention application is cured in two stages. On the one hand, it realizes that the sealant supports UV and heat dual curing modes at the same time. On the other hand, the sealant can be cured within 10 seconds during the factory assembly stage, which greatly shortens the processing time, improves assembly efficiency, and reduces manufacturing costs.

[0059] The light-heat dual-curing long-lasting sealing silicone rubber samples prepared by the above embodiment of the present invention have been put into trial use and applied to the assembly of power lithium battery modules and hydrogen fuel cell modules of the ternary system, specifically to connect and seal the gap between two battery metal shells. The actual trial shows that the sealing structural adhesive layer prepared by the method can meet the high sealing and high disaster tolerance performance requirements required by new energy batteries.

[0060] In addition to introducing a small amount of polymerization inhibitor, the two-stage reaction method provided in the above embodiment of the present invention can also implement the polymerization inhibition strategy under specific conditions to reduce the polymerization activity of vinyl siloxane by reasonably adjusting the polymerization conditions during UV curing. For example, the wavelength and intensity of the light source are adjusted, and the excitation efficiency of the photoinitiator is adjusted by using UV light of appropriate wavelength and intensity, thereby controlling the generation rate of free radicals and affecting the polymerization activity of the vinyl siloxane molecular group under UV conditions. The details will not be elaborated in detail.

[0061] It should be particularly pointed out that the components, proportions, particle sizes and process parameters used in the above-mentioned specific embodiments of the present invention are only examples. Other different implementation schemes obtained by making specific selections within the scope recorded in the basic embodiments of the present invention can achieve the technical effects recorded in the present invention, so the present invention will not list them one by one.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. All equivalent changes made according to the components, proportions and processes of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a light-heat dual-curing long-lasting sealing silicone rubber, characterized in that: It includes the following steps: S1: Prepare the raw materials according to the following mass ratios Acrylic modified polysiloxane 50~80 Vinyl polysiloxane 20~50 Hydrogen silicone oil 8~15 Fumed silica 20~30 Catalyst sustained-release microcapsules 0.3~0.5 Initiator 1.5~3 Thickener 1~2 Aromatic amine inhibitor 0.15~0.25 The catalyst sustained-release microcapsules are single-component platinum catalyst sustained-release microcapsules with an average particle size of 4 to 6 μm, a capsule wall shell formed by PP resin completely covering spherical particles of platinum catalyst, and a melting temperature of the capsule wall shell of not less than 150°C; S2: Preparation of silicone rubber base material The acrylic modified polysiloxane and the vinyl polysiloxane are sequentially added into a kneader, and the fumed silica is added in batches, kneaded at room temperature, and then vacuumed at 150°C, kneaded again, and cooled to room temperature to obtain a silicone rubber base material; S3: Preparation of long-lasting sealing silicone rubber To the silicone rubber base material, hydrogen-containing silicone oil, catalyst sustained-release microcapsules, initiator, viscosity enhancer and aromatic amine inhibitor are added in sequence, and after stirring and mixing evenly, a long-lasting sealing silicone rubber is obtained; under the action of the aromatic amine inhibitor, two types of molecular groups acrylate and vinyl siloxane with different reactivity rates participate in the first step of UV curing and the second step of heating curing, respectively, and after step-by-step curing, structural adhesive layers with different properties are obtained accordingly.

2. The method for preparing the light-heat dual-curing long-lasting sealing silicone rubber according to claim 1, characterized in that: S1 also includes the following steps: S1-1: Preparation of catalyst sustained-release microcapsules S1-1-1: Add platinum catalyst and PP resin to D80 solvent oil at a mass ratio of (1.5-2):1, raise the temperature to 60-70°C, stir and dissolve, control the stirring speed to 300-500 rpm, and keep stirring for 2-3 hours. By controlling the ratio of platinum catalyst and PP resin and the stirring speed, the obtained capsule wall shell thickness is 2-3 μm; S1-1-2: Then the mixed solution is added dropwise to the polypropylene alcohol aqueous solution, and after the addition, it is stirred at room temperature, and the stirring speed is controlled to be 500-600 rpm for 6-8 hours to obtain spheres with an average particle size of 4-6 μm and a smooth outer surface; S1-1-3: Remove the solvent by distillation under reduced pressure to obtain spherical single-component platinum catalyst sustained-release microcapsules with a capsule wall thickness of 2-3 μm and an average particle size of 4-6 μm.

3. The method for preparing the light-heat dual-curing long-lasting sealing silicone rubber according to claim 2, characterized in that: S1-1 specifically includes the following steps: The PP resin is a PP resin with a melting point greater than 150°C, including homopolymer grade PP or copolymer grade PP; The platinum catalyst is a Karstedt platinum catalyst.

4. The method for preparing the light-heat dual-curing long-lasting sealing silicone rubber according to claim 1, characterized in that: S1 also includes the following steps: S1-2: Preparation of acrylic modified polysiloxane S1-2-1: 1000 parts by weight of octamethylcyclotetrasiloxane, 2 to 5 parts by weight of tetramethyldivinyldisiloxane, and 200 to 350 parts by weight of hydroxy acrylate were respectively added to a reaction kettle; S1-2-2: Raise the temperature to 90-110°C while stirring, then add 1-3 parts by weight of tetramethylammonium hydroxide, continue stirring, and polymerize for 5 hours; S1-2-3: Remove the catalyst and small molecules at 150-170°C and 0.1 MPa negative pressure to obtain acrylic acid-modified polysiloxane.

5. The method for preparing the light-thermal dual-curing long-lasting sealing silicone rubber according to claim 1, characterized in that: Step S2 is to prepare a silicone rubber base material, comprising the following specific steps: S2-1: First, add acrylic modified polysiloxane and vinyl polysiloxane into a kneader in sequence; S2-2: Add fumed silica in batches and knead at room temperature for 1 hour; S2-3: Evacuate at 150°C, knead for 3 hours, and then cool to room temperature to obtain a silicone rubber base material.

6. The method for preparing the light-heat dual-curing long-lasting sealing silicone rubber according to claim 1, characterized in that: Step S3 is to prepare the long-lasting sealing silicone rubber, comprising the following specific steps: S3-1: Add hydrogen-containing silicone oil, platinum catalyst slow-release microcapsules, initiator, tackifier, and aromatic amine inhibitor to the silicone rubber base material in proportion; S3-2: Mix evenly in a mixer at room temperature to obtain a long-lasting sealing silicone rubber; The aromatic amine polymerization inhibitor is diphenylamine or N-nitrosodiphenylamine.

7. A light-heat dual-curing long-lasting sealing silicone rubber, characterized in that: The invention discloses a method for preparing the invention.

8. The light-heat dual-curing long-lasting sealing silicone rubber according to claim 7, characterized in that: Under the action of aromatic amine inhibitors, two types of molecular groups with significantly different competitive polymerization rates participate in the curing reaction in two steps. The first step is a UV curing reaction involving acrylate molecular groups. The second step is a thermal curing hydrosilylation reaction in which the vinyl siloxane molecular groups participate together with the platinum catalyst passively released from the platinum catalyst sustained-release microcapsules when the temperature reaches above 150°C.

9. An application of a light-heat dual-curing long-lasting sealing silicone rubber, characterized in that: The photothermal dual-curing long-lasting sealing silicone rubber described in claim 7 or 8 is used as a structural sealant in the manufacture of hydrogen fuel cells or lithium batteries to seal the structural surface of hydrogen fuel cells or lithium batteries. After two-step curing, the structural adhesive layer successively meets the different performance requirements of the structural sealing stage and the disaster recovery stage.

10. The use of the light-heat dual-curing long-lasting sealing silicone rubber according to claim 9, characterized in that: It includes the following steps: A1: Apply the light-heat dual-curing long-lasting sealing silicone rubber on the sealing structure surface of the hydrogen fuel cell or lithium battery, use UV to cure the structural adhesive layer in the first step, and under the action of aromatic amine inhibitors, the double bonds of the acrylate groups undergo free radical polymerization to form a structural adhesive layer, and its performance meets the requirements of the structural sealing stage; A2: Bond another sealing structure surface to the structural adhesive layer to form a layered sealing adhesive structure of the battery; A3: When the temperature of any sealing structure surface rises to greater than 150°C, the capsule shell of the platinum catalyst sustained-release microcapsule melts due to the heat, quickly releasing the platinum catalyst inside the microcapsule, and undergoing a thermal curing reaction with the vinyl siloxane molecular groups, so that the sealing structure adhesive layer is thermally cured, rapidly increasing the mechanical properties, heat resistance and flame retardancy of the sealing structure adhesive layer, so that it meets the performance requirements of the disaster recovery stage.

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