Long-acting anti-aging high-bond-strength elastic hybrid adhesive, preparation method and application thereof

Abstract

The application belongs to the technical field of adhesive manufacturing, and discloses a long-acting anti-aging high-adhesion-strength elastic hybrid adhesive, a preparation method and application thereof. The preparation method comprises the following steps: preparing a long-acting A component with weak acidity and high storage stability, and preparing a long-acting B component with high storage stability; through synchronous improvement of the adhesive formula and process, a ternary hybrid system is adopted, and the problems of compatibility of the ternary system and hydrolysis of the MS catalyst are overcome, so that the prepared A and B components can be stored stably for a long time, the adhesive can have high strength, high elasticity, high storage stability and low cost at the same time, the adhesive is convenient to produce and can be stored stably for a long time, and the adhesive can be widely applied to the manufacturing of power battery cells and other products and can meet various actual application requirements of the industry.

Description

Technical Field

[0001] This invention belongs to the field of adhesive manufacturing technology, specifically relating to a long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application. Background Technology

[0002] MS-based adhesives, also known as silane-modified polyether adhesives, are adhesives made using MS polymers as the base polymer, combined with fillers, plasticizers, and other functional additives. Currently, adhesives prepared based on silane-modified polymers (MS resins), such as MS sealants or MS hybrid structural adhesives, are increasingly widely used due to their excellent adhesion to various substrates, superior elasticity, and good strength. However, the widespread use of MS-based adhesives is limited by problems such as hydrolysis (poor storage stability), poor mechanical properties, and high cost. It is particularly important to note that MS-based adhesives cannot simultaneously achieve high strength, high elasticity, and long-term storage stability (i.e., high storage stability), and this problem cannot be solved using conventional technologies.

[0003] For example, Chinese Patent Publication No. CN112552870A discloses a high-strength, high-hardness UV / moisture dual-curing MS adhesive and its preparation method, which uses a single component composed of high-modulus silane-modified polyether polymer to solve the problem of poor strength of traditional MS adhesives; CN111732933A discloses a high-strength, high-hardness epoxy-modified MS sealant and its preparation method, which introduces an epoxy system or an acrylic system into the MS system to improve strength and hardness. While both of these technologies improve the strength of the material, they also increase the hardness of the adhesive and decrease its elasticity, making them unsuitable for bonding and sealing applications with high requirements such as vibration and thermal expansion and contraction. Moreover, neither of them can overcome the problems of moisture absorption and hydrolysis and poor storage stability during long-term storage and transportation.

[0004] For example, Chinese Patent Publication No. CN109880569A discloses an epoxy resin modified MS sealant, which adopts a two-component, binary resin system. Component B includes a small amount of water as a co-catalyst. In a specific embodiment (Example 2), a relatively superior adhesive layer with good strength and elasticity can be obtained. However, this embodiment is a filler-free formulation, which is costly. The adhesive layer prepared by Example 1 after adding fillers (the system is alkaline) has significantly reduced performance and it is difficult to achieve both high strength and high elasticity at the same time. In addition, in the embodiments of this patent, when MS catalyst and deionized water are added to component B at the same time, although deionized water has a curing-promoting effect and can act as a co-catalyst, MS catalyst is a substance that is easily hydrolyzed. Therefore, the catalyst will gradually decompose and become inactive in the presence of water. In the alkaline system, the hydrolysis rate is accelerated. Therefore, it cannot be stored stably for a long time. Actual test results show that its component B usually loses catalytic activity after several weeks to several months under room temperature storage conditions, and loses most of its catalytic activity in just one day under high temperature storage conditions of 50°C.

[0005] In current industrial applications, domestic downstream customers of adhesives typically have an inventory cycle of about three months, while overseas customers need to add another three months or longer for shipping. Currently, the shelf life of MS system adhesives is generally three to four months, and during storage, hydrolysis causes varying degrees of performance degradation. This forces companies to resort to operational measures such as forcibly shortening inventory cycles or technical measures such as increasing adhesive usage to ensure timely use while adhesive performance is still good, or to avoid product quality defects due to performance degradation. However, these methods all increase costs for companies and cannot meet the industry's needs for cost reduction, efficiency improvement, and quality enhancement. Summary of the Invention

[0006] To address the aforementioned shortcomings of existing technologies, this invention provides a long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive, its preparation method, and its applications. By simultaneously improving the adhesive formulation and process, a ternary hybrid system is adopted, and problems such as the compatibility of ternary systems and the hydrolysis of MS catalysts are overcome. This allows both the A and B components to be stored stably for a long period of time, thereby enabling the adhesive to simultaneously achieve high strength, high elasticity, high storage stability, and low cost. It is easy to produce and can be stored stably for a long period of time, thus solving the aforementioned technical problems.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive includes the following steps:

[0009] S1: Preparation of component A

[0010] According to the set ratio, MS resin, acrylic modified MS resin, epoxy resin, plasticizer, filler, and thixotropic additive are added to a double planetary mixer and dispersed, stirred evenly, vacuumed, heated to 110-120℃, and then dispersed and stirred at a constant temperature and high speed to obtain dehydrated material.

[0011] Keep the dehydrated material under vacuum and lower the temperature to below 30°C. Add the coupling agent and epoxy catalytic curing agent. Stir evenly under normal pressure, continue to keep the vacuum, heat to 90-100°C, and disperse and stir at high speed at constant temperature to allow the coupling agent to fully react with the active groups of MS resin, acrylic modified MS resin, epoxy resin, filler, and thixotropic additive to obtain the resin base. Then, cool the material to below 30°C.

[0012] Deionized water and a pH adjustment solution with a pH value of no more than 2, prepared in advance, were added to the resin base. After being stirred and dispersed evenly under normal pressure, the mixture was vacuumed and stirred at low speed to remove bubbles. The mixture was then removed from the reactor and sealed in packaging to obtain a long-lasting component A with a weakly acidic overall system and high storage stability.

[0013] S2: Preparation of component B

[0014] According to the set ratio, MS resin, acrylic modified MS resin, plasticizer, filler, antioxidant, and thixotropic additive are added to a double planetary mixer and disperser. After being stirred evenly, vacuum is applied, and the mixture is heated to 110-120℃. After constant temperature and high-speed stirring, dispersion, and dehydration, dehydrated material is obtained.

[0015] The dehydrated material is cooled to below 30°C under vacuum, then a dehydrating agent is added. The mixture is stirred and dispersed under normal pressure until it is evenly mixed. While maintaining the vacuum, a coupling agent, an epoxy catalytic curing agent, and an MS catalyst are added. The mixture is stirred and dispersed under normal pressure until it is evenly mixed. Then, a vacuum is drawn, and the mixture is stirred at low speed to remove bubbles. The mixture is then removed from the reactor and sealed in packaging to obtain a long-lasting B component with high storage stability.

[0016] S3: Mixing and Curing

[0017] Mix component A and component B evenly at a volume ratio of 2:1, and then apply the mixture to the surface of the substrate to be bonded to form an adhesive coating.

[0018] The adhesive coating is cured at room temperature for at least 5 days or at 50°C for at least 10 hours. During the curing process, the moisture in component A is continuously consumed. After curing, a long-lasting hybrid adhesive layer with high strength, high elasticity, and resistance to humid heat aging is obtained.

[0019] A long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive is prepared using the aforementioned preparation method.

[0020] Application of the aforementioned long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive in the manufacturing of power battery cells.

[0021] The long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided by this invention have at least the following beneficial effects:

[0022] 1. This invention, through simultaneous improvement of adhesive formulation and process, adopts a ternary hybrid system, overcoming problems such as compatibility of ternary systems and hydrolysis of MS resin and MS catalyst. This enables both AB components to be stored stably for a long time, thus allowing the adhesive to simultaneously achieve high strength, high elasticity, high storage stability, and low cost. It is easy to produce and can be stored stably for a long time. Furthermore, after curing, it can produce an adhesive layer with a dense structure, significantly improved sealing performance, and resistance to humid heat aging, thus meeting the needs of practical industrial applications.

[0023] 2. The adhesive provided by this invention has two components, A and B, that work together. It simultaneously introduces an acrylic system and an epoxy system into the MS system. By controlling the reasonable proportion of the three systems through formulation design, and by controlling the amount of filler, pH adjuster, and water added, it solves the problems of material compatibility, hydrolysis resistance, and delamination resistance, as well as the problem of not being able to simultaneously achieve high strength, high elasticity, high density, and resistance to damp heat aging of the cured adhesive layer. Thus, it provides a low-cost, easy-to-prepare, high-adhesion-strength (9-14MPa), high-tensile-strength (10-15MPa), high-elasticity (200%-500%), and long-stable storage period (more than 12 months) two-component MS hybrid adhesive system.

[0024] 3. The two-component MS hybrid adhesive system provided by this invention improves the long-term storage stability of the two-component MS hybrid adhesive by adjusting the proportions of the three systems and improving the corresponding catalysts and storage conditions, and by introducing an acidic pH adjuster and deionized water into component A. Components A and B show virtually no performance change after 6 months of storage at room temperature, and the performance loss is less than 5% after 12 months of storage; the performance loss after 30 days of storage at 50°C is also less than 10%, all within the range allowed for industrial applications. At the same time, because the provided deionized water enables the curing process to occur uniformly from the inside of the adhesive layer, it significantly improves the density and various properties of the cured adhesive layer. After long-term use, when the performance loss of the adhesive layer of ordinary MS hybrid adhesive formulation exceeds 60% after hygrothermal aging, the performance loss of the adhesive layer of this invention does not exceed 20%.

[0025] 4. The technical solution adopted in this invention is to simultaneously introduce acrylic-modified MS and epoxy systems into the MS system for hybridization. Component A is designed to contain MS resin, acrylic-modified MS resin, epoxy resin, and deionized water, and is generally weakly acidic. Component B is designed to contain MS resin and acrylic-modified MS resin. By controlling the ratio of MS / acrylic-modified MS / epoxy resin after mixing components A and B, better material compatibility and comprehensive performance can be obtained. At the same time, the three resins in component A are pre-treated with coupling agents to modify them and to coat fillers, thereby enhancing the hybridization uniformity of the MS resin, acrylic-modified MS, and epoxy systems after the components A and B are mixed and cured, and preventing the fillers from reacting with acidic pH adjusters during storage and transportation. Based on the above optimizations, the final cured colloid can simultaneously achieve high strength, high elasticity, and resistance to damp heat aging.

[0026] 5. This invention employs the addition of water to component A, enabling the mixture of A and B to exhibit rapid, deep, and uniform curing properties. Simultaneously, the introduction of water and an acidic pH adjuster into component A makes the overall system of component A weakly acidic, thereby preventing the MS catalyst and MS resin from hydrolyzing in the presence of water in component A. Furthermore, the weak acidity also inhibits further cross-linking of the MS resin during long-term storage and transportation, which could lead to performance degradation.

[0027] 6. The two-component MS hybrid adhesive of the present invention improves the bonding strength (8-10 MPa) of the MS two-component hybrid adhesive to different substrates by optimizing the performance of the acrylic system and epoxy system. It can be widely used on a variety of substrates with different polarities, including metal materials such as aluminum and stainless steel, and various plastics such as high polarity plastics PVC and PA and low polarity plastics PET, thus meeting the industrial application needs for bonding different materials.

[0028] 7. The application of the long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive provided by this invention, when used for bonding and fixing the cells of a power battery, results in a high-strength and highly elastic adhesive layer after curing. This can solve the structural failure problem caused by damage to the adhesive layer under alternating conditions such as battery vibration and thermal expansion and contraction. When used for sealing power battery modules, the higher structural density (sealing performance) and damp heat aging performance of the cured adhesive layer can effectively extend the life of the power battery pack and synergistically improve the overall safety performance of the power battery pack. Attached Figure Description

[0029] Figure 1 This is a scanning electron microscope (SEM) image of the cross-section of the adhesive layer after curing in Example 3 of the present invention, at a scale of 20 μm.

[0030] Figure 2 This is a scanning electron microscope image of the cross-section of the adhesive layer at a scale of 4 μm after curing, according to Example 3 of the present invention.

[0031] Figure 3 This is a scanning electron microscope image of the cross-section of the adhesive layer after curing in Comparative Example 3 of the present invention at a scale of 20 μm.

[0032] Figure 4 This is a scanning electron microscope (SEM) image of the 4μm cross-section of the adhesive layer after curing of the adhesive of Comparative Example 3 of the present invention. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Basic Implementation

[0035] The preparation method of the long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive provided in this embodiment includes the following steps:

[0036] S1: Preparation of component A

[0037] According to the set ratio, MS resin (silane-terminated polyether resin), acrylic modified MS resin (acrylic modified silane-terminated polyether resin), epoxy resin, plasticizer, filler, and thixotropic additive are added to a double planetary mixer and stirred evenly. Vacuum is applied, and the mixture is heated to 110-120℃. After constant temperature and high-speed dispersion and stirring to dehydrate, dehydrated material is obtained.

[0038] Maintaining a vacuum over the dehydrated material and lowering the temperature to below 30°C, add the coupling agent and epoxy catalytic curing agent. Stir evenly under normal pressure, then continue to maintain a vacuum and heat to 90-100°C. Maintain constant temperature and high-speed dispersion stirring to ensure sufficient reaction between the coupling agent and the active groups of MS resin, acrylic-modified MS resin, epoxy resin, filler, and thixotropic additive, obtaining a resin base. Cool to below 30°C. In this step, the full reaction between the coupling agent and the active groups of MS resin, acrylic-modified MS resin, epoxy resin, filler, and thixotropic additive occurs after the high-temperature dehydration in the previous step. The filler (nanocarbon)... After the water molecules adsorbed on the surface of the filler (calcium oxychloride) or thixotropic additive (fumed silica) dissociate or are removed, the hydroxyl groups on the filler surface are exposed in the resin. The active groups on the filler surface are mainly hydroxyl groups and modified ester groups. When the coupling agent is stirred at normal pressure in the presence of trace amounts of water, some of the silanoxy groups of the coupling agent hydrolyze to generate silanols, and some silanols also condense to form oligomeric silanes. The ester groups improve the compatibility between the filler and the resin. The silane oxygen bonds in the unhydrolyzed coupling agent and oligomeric silanes, as well as the silanols generated by the hydrolysis of the coupling agent, react with the hydroxyl groups on the filler surface to form a molecular modification layer. The amino group at the other end of the coupling agent is exposed in the resin. The amino group can react with the epoxy group at one end of the epoxy resin, causing part of the epoxy resin to encapsulate the filler. 2,4,6-tris(dimethylaminomethyl)phenol also plays a catalytic role in this process. During atmospheric pressure stirring, the silanoxy groups at the ends of some MS resins and acrylic-modified MS resins undergo hydrolysis in the presence of trace amounts of water and catalysis by 2,4,6-tris(dimethylaminomethyl)phenol. These hydrolysates can then react with the hydroxyl groups on the filler surface to encapsulate the filler; or they can condense with partially hydrolyzed coupling agents. Simultaneously, the amino group at the other end of the condensed coupling agent reacts with the epoxy groups of the epoxy resin, causing partial cross-linking of the two resin molecules to form a larger polymer. This polymer entangles with the resin molecules on the filler surface, further strengthening the resin's encapsulation of the filler surface.

[0039] Deionized water and a pH adjustment solution with a pH value of no more than 2, prepared in advance, were added to the resin base. After being stirred and dispersed evenly under normal pressure, the mixture was vacuumed and stirred at low speed to remove bubbles. The mixture was then removed from the reactor and sealed in packaging to obtain a long-lasting component A with a weakly acidic overall system and high storage stability.

[0040] Specifically, the steps include the following:

[0041] S1-1: Prepared according to the following mass ratios: 30-50 parts MS resin; 5-30 parts acrylic modified MS resin; 20-50 parts epoxy resin; 0-15 parts plasticizer; 5-25 parts filler; 0-2 parts thixotropic agent; 1-3 parts coupling agent; 0.3-0.75 parts epoxy catalytic curing agent; appropriate amount of acidic pH adjuster and deionized water;

[0042] S1-2: Preparation of dehydrated material: MS resin, acrylic modified MS, epoxy resin, plasticizer, filler, and thixotropic agent are added to a double planetary mixer and disperser. After stirring at atmospheric pressure and 25°C for 30 minutes, vacuum is applied and the vacuum degree is maintained at ≤-95kPa. The mixture is heated to 110-120°C and then dispersed and stirred at high speed for 2 hours to obtain the dehydrated material.

[0043] S1-3: Mutual reaction: Keep the vacuum degree of the dehydrated material ≤-95kPa and lower the temperature to below 30℃. Add coupling agent and epoxy catalytic curing agent to the dehydrated material. Stir under normal pressure for 30min. Keep the vacuum degree ≤-95kPa and heat to 90~100℃. Disperse and stir at high speed at constant temperature to allow the coupling agent to react with the active groups of MS resin, acrylic modified MS resin, epoxy resin and filler for 1.5 hours. Make the resin completely coat the surface of the filler to obtain resin base. Keep the vacuum degree ≤-95kPa and lower the temperature to below 30℃.

[0044] In this step, the coupling agent reacts with the active groups on the surface of the ternary resin and filler, establishing a strong physical-chemical bond between the resin and the filler. This also makes the polymer resin more uniform and tightly encapsulate the filler, which can improve the strength of the cured adhesive layer and prevent the filler from reacting with acidic pH adjusters during manufacturing and storage.

[0045] S1-4: Preparation of pH Adjuster Solution: Take 1.5-2.0 times the amount of deionized water required for the complete hydrolysis reaction of MS resin and coupling agent, dissolve an appropriate amount of acidic pH adjuster in the deionized water, and obtain a pH adjuster solution with a pH of 1-2; the amount of water required for the complete hydrolysis reaction of MS resin and coupling agent can be calculated according to conventional techniques, such as the following formula:

[0046]

[0047] In the formula:

[0048] · M The mass of MS resin (in kg)

[0049] · S The mass of the coupling agent (in kg).

[0050] · T Hydrolysis temperature (in °C)

[0051] · t Hydrolysis time (in hours)

[0052] · wThe amount of water required for complete hydrolysis (in kg).

[0053] · The specific parameters in the above formula (such as 0.6 and 0.035) can be adjusted as needed.

[0054] S1-5: Adjusting the pH of the system: Add a pH adjusting agent solution to the resin base to make the system weakly acidic, and stir and disperse for 30 minutes under normal pressure;

[0055] In this step, the filler has been pre-encapsulated by the resin material and will not react with the acidic pH adjuster. The addition of the acidic pH adjuster makes the system weakly acidic overall. This is to prevent the MS catalyst and MS resin from undergoing hydrolysis or pre-crosslinking during storage and transportation. The quantitatively added water is used for the curing of the MS resin after the AB components are mixed. It is completely consumed during the curing process, which can significantly improve the curing speed and effect (achieving deep and uniform curing).

[0056] S1-6: Discharge: Vacuum and low-speed stirring for 10 minutes to remove bubbles, then discharge from the reactor and seal in packaging to obtain long-lasting component A that can be stored stably for a long time.

[0057] In this embodiment, water is added to component A, so the curing process is not affected by the humidity of the curing environment and there is no need to deliberately control the humidity in the curing environment. An acidic pH adjuster is introduced to make the system weakly acidic (pH 5-6), thereby inhibiting the MS catalyst and MS resin in component A from undergoing hydrolysis or further cross-linking reaction under the presence of added moisture and during long-term storage and transportation, which would lead to an increase in the viscosity and a decrease in the performance of the adhesive.

[0058] S2: Preparation of component B

[0059] According to the set ratio, MS resin, acrylic modified MS resin, plasticizer, filler, antioxidant, and thixotropic additive are added to a double planetary mixer and disperser. After being stirred evenly, vacuum is applied, and the mixture is heated to 110-120℃. After constant temperature and high-speed stirring, dispersion, and dehydration, dehydrated material is obtained.

[0060] The dehydrated material is cooled to below 30°C under vacuum, then a dehydrating agent is added. The mixture is stirred and dispersed under normal pressure until it is evenly mixed. While maintaining the vacuum, a coupling agent, an epoxy catalytic curing agent, and an MS catalyst are added. The mixture is stirred and dispersed under normal pressure until it is evenly mixed. Then, a vacuum is drawn, and the mixture is stirred at low speed to remove bubbles. The mixture is then removed from the reactor and sealed in packaging to obtain a long-lasting B component with high storage stability.

[0061] Specifically, the steps include the following:

[0062] S2-1: Prepared according to the following mass ratios: 20-40 parts MS resin; 5-45 parts acrylic modified MS resin; 0-30 parts plasticizer; 5-40 parts filler; 10-25 parts epoxy catalytic curing agent; 2-10 parts antioxidant; 0.5-3 parts dehydrating agent; 2-20 parts coupling agent; 0-5 parts thixotropic agent; 2-6 parts MS catalyst;

[0063] S2-2: Preparation of dehydrated material: MS resin, acrylic modified MS, plasticizer, filler, antioxidant, and thixotropic agent are added to a double planetary mixer and disperser. After stirring at atmospheric pressure and 25°C for 30 minutes, vacuum is applied and the vacuum degree is maintained at ≤-95kPa. The mixture is heated to 110-120°C and dispersed and dehydrated by constant temperature and high-speed stirring for 2 hours to obtain dehydrated material. The dehydrated material is kept under vacuum of ≤-95kPa and cooled to below 30°C.

[0064] S2-3: Dehydration: Add dehydrating agent to the dehydrated material under vacuum, stir and disperse under normal pressure for 10 minutes until the material is evenly mixed, then evacuate and maintain the vacuum degree at ≤-95kPa, stir and disperse again for 10 minutes to fully dehydrate;

[0065] S2-4: Additive mixing: Add coupling agent, epoxy catalytic curing agent and MS catalyst to the dehydrated material after water removal. Stir and disperse under normal pressure for 5 minutes until the material is evenly mixed. Then, apply vacuum and maintain the vacuum degree at ≤-95kPa, and stir and disperse for 30 minutes.

[0066] S2-5: Discharge: Vacuum-assisted low-speed stirring for 10 minutes to remove bubbles, discharge from the reactor and seal packaging to obtain a stable long-lasting component B;

[0067] S3: Mixing and Curing

[0068] Mix component A and component B evenly at a volume ratio of 2:1, and then apply the mixture to the surface of the substrate to be bonded, or to the gap between the bonding surfaces of two substrates to be bonded, to form an adhesive coating.

[0069] The adhesive coating is cured at room temperature for at least 5 days or at 50°C for at least 10 hours. During the curing process, the moisture in component A is continuously consumed. After curing, a long-lasting hybrid adhesive layer with high strength, high elasticity, and resistance to humid heat aging is obtained. The specific steps include the following:

[0070] S3-1: Mixing: Mix component A and component B evenly at a volume ratio of 2:1, and then apply the mixture to the surface of the substrate to be bonded, or to the gap between the bonding surfaces of two substrates to be bonded, to form an adhesive coating.

[0071] S3-2: Curing: The adhesive coating is cured by heating at room temperature (15-35℃) for 7 days or at 50℃ for 16 hours. During the curing process, the moisture in component A is continuously consumed. After curing, a long-lasting hybrid adhesive layer with no free water molecules inside is obtained, which combines high strength and high elasticity and is resistant to humid heat aging.

[0072] In the long-lasting hybrid adhesive layer after component A and component B are mixed and cured:

[0073] The weight ratio of MS resin, acrylic modified MS resin, and epoxy resin is (40-60):(10-40):(20-35), and the ratio of the total weight parts of MS resin and acrylic modified MS resin to the weight parts of epoxy resin is ≥2.

[0074] In the total weight parts of MS resin and acrylic-modified MS resin, the proportion of acrylic-modified MS resin is ≥20%;

[0075] The filler mass percentage is ≤20%;

[0076] The mass ratio of MS catalyst to the total mass of MS resin and acrylic acid-modified MS is 1%-3%.

[0077] The mass ratio of epoxy resin curing agent to epoxy resin is 15%-25%;

[0078] The deionized water in the pH adjuster solution is completely consumed during the curing reaction.

[0079] The MS resin is a silane-terminated polyether resin, specifically one or a mixture of Kaneka resin SAX750, SAX400, SAX260, Ruiyang Antai TUPS400T, TUPS303T, and TUPS350D.

[0080] The acrylic-modified MS resin is an acrylic-modified silane-terminated polyether resin, specifically a mixture of at least one or more of the following resins: MA480, MA490, and MA602.

[0081] The epoxy resin is E51 or E44;

[0082] The MS catalyst is one or more of the following: stannous octoate, dibutyltin dilaurate, dioctyltin dilaurate, di-n-butylbis(acetylacetonyl)tin, and 1,3-dilauroyloxy-1,1,3,3-tetrabutyldistannous oxide (U-130), preferably U-130 from Nitto Chemicals.

[0083] The plasticizer is a polyether polyol with a molecular weight greater than 1000, such as PPG3000;

[0084] The epoxy catalytic curing agent is 2,4,6-tris(dimethylaminomethyl)phenol or tert-butylphenol;

[0085] The antioxidant is one of IRGANOX 1010, IRGANOX 1076, and IRGANOX 1135;

[0086] The dehydrating agent is a vinylmethoxysilane, specifically one of vinyltrimethoxysilane (A-171), methylvinyldimethoxysilane, or vinyltris(2-methoxyethoxy)silane;

[0087] The coupling agent is an amino coupling agent, specifically one or a mixture of KH-540, KH-550, and KH-792;

[0088] The filler is nano-calcium carbonate with an oil absorption value of ≤35±1mL / 100g and an average particle size of ≤100nm. Specifically, it is one or a mixture of CCS-18, CCS-25, and CCS-25i.

[0089] The filler can be further supplemented with reinforcing carbon black, preferably Cabot M570 or M460, with the amount of carbon black added not exceeding 2 parts by weight;

[0090] The thixotropic agent is one or a mixture of two of fumed silica or polyamide wax;

[0091] The acidic pH adjuster in component A is a water-soluble weak acid, specifically citric acid or succinic acid. The amount added is such that the pH of the pH adjuster solution is between 1 and 2, and the mass ratio is no more than 3% of the filler weight in component A.

[0092] A long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive is prepared using the aforementioned preparation method.

[0093] The aforementioned long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive can be used in the manufacturing of power battery cells as a structural adhesive or sealant to bond and seal the structural surfaces of the power battery cell substrate to be bonded.

[0094] The key feature of this invention is the simultaneous improvement of adhesive formulation and process, employing a ternary hybrid system. This overcomes issues such as compatibility of ternary systems and hydrolysis of MS resin and MS catalyst, enabling both AB components to be stored stably for a long period. Consequently, the adhesive simultaneously achieves high strength (mainly contributed by epoxy resin and fillers), high elasticity (mainly contributed by acrylic / MS resin), high storage stability (mainly contributed by high compatibility and weakly acidic system), and low cost (contributed by fillers). This facilitates production and allows for long-term stable storage. Furthermore, after curing, it yields an adhesive layer with a dense structure, significantly improved sealing performance, and enhanced resistance to damp heat aging, thus meeting the needs of practical industrial applications.

[0095] The present invention will be further described in detail below with reference to the accompanying drawings, several specific embodiments, comparative examples, and test results.

[0096] Example 1

[0097] The long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided in this embodiment are specific modifications based on the basic embodiment, with the following differences:

[0098] The specific components and proportions used in components A and B of this embodiment are shown in Table 1.

[0099] The preparation method of the long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive provided in this embodiment specifically includes the following steps:

[0100] S1: Preparation of component A

[0101] S1-1: Prepared according to the following mass ratios: SAX750 (Kaneka MS resin) 45 parts; MA480 (Kaneka acrylic modified MS resin) 9 parts; epoxy resin E51 30 parts; plasticizer PPG3000 2 parts; filler CCS-18 nano calcium carbonate 8 parts; thixotropic agent fumed silica 1 part; KH540 coupling agent 2 parts; epoxy catalytic curing agent K54 (2,4,6-tris(dimethylaminomethyl)phenol) 0.45 parts; acidic pH adjuster citric acid 0.16 parts; deionized water 1.5 parts.

[0102] S1-2: Preparation of dehydrated material: MS resin (silane-terminated polyether resin), acrylic modified MS resin (acrylic modified silane-terminated polyether resin), epoxy resin, plasticizer, filler, and thixotropic agent are added to a double planetary mixer and dispersed. After stirring at atmospheric pressure and 25°C for 30 min, vacuum is applied and the vacuum degree is maintained at ≤-95 kPa. The mixture is heated to 110-120°C and then dispersed and stirred at high speed for 2 hours to obtain the dehydrated material.

[0103] S1-3: Mutual reaction: Keep the vacuum degree of the dehydrated material ≤-95kPa and lower the temperature to below 30℃. Add coupling agent and epoxy catalytic curing agent to the dehydrated material. Stir under normal pressure for 30min. Keep the vacuum degree ≤-95kPa and heat to 90~100℃. Disperse and stir at high speed at constant temperature to allow the coupling agent to react with the active groups of MS resin, acrylic modified MS resin, epoxy resin and filler for 1.5 hours. Make the resin completely coat the surface of the filler to obtain resin base. Keep the vacuum degree ≤-95kPa and lower the temperature to below 30℃.

[0104] S1-4: Preparation of pH adjustment solution: Take twice the amount of deionized water required for the complete hydrolysis reaction of MS resin and coupling agent, dissolve an appropriate amount of acidic pH adjustment agent in deionized water to obtain a pH adjustment solution with a pH of approximately 1.7.

[0105] S1-5: Adjusting the pH of the system: Add a pH adjusting agent solution to the resin base to make the system weakly acidic, and stir and disperse for 30 minutes under normal pressure;

[0106] S1-6: Discharge: Vacuum and low-speed stirring for 10 minutes to remove bubbles, then discharge from the reactor and seal in packaging to obtain long-lasting component A that can be stored stably for a long time.

[0107] S2: Preparation of component B

[0108] S2-1: Prepared according to the following mass ratios: SAX750 (MS resin) 30 parts; MA480 (acrylic modified MS resin) 20 parts; PPG3000 plasticizer 4 parts; filler CCS-18 nano calcium carbonate 12 parts; M570 carbon black 1 part; K54 (epoxy catalytic curing agent) 12 parts; IRGANOX 1010 antioxidant 5 parts; A171 dehydrating agent 1 part; KH540 coupling agent 8 parts; polyamide wax SL thixotropic agent 1 part; U-130 MS catalyst 3 parts;

[0109] S2-2: Preparation of dehydrated material: MS resin, acrylic modified MS, plasticizer, filler, antioxidant, and thixotropic agent are added to a double planetary mixer and disperser. After stirring at atmospheric pressure and 25°C for 30 minutes, vacuum is applied and the vacuum degree is maintained at ≤-95kPa. The mixture is heated to 110-120°C and dispersed and dehydrated by constant temperature and high-speed stirring for 2 hours to obtain dehydrated material. The dehydrated material is kept under vacuum of ≤-95kPa and cooled to below 30°C.

[0110] S2-3: Dehydration: Add dehydrating agent to the dehydrated material under vacuum, stir and disperse under normal pressure for 10 minutes until the material is evenly mixed, then evacuate and maintain the vacuum degree at ≤-95kPa, stir and disperse again for 10 minutes to fully dehydrate;

[0111] S2-4: Additive mixing: Add coupling agent, epoxy catalytic curing agent and MS catalyst to the dehydrated material after water removal. Stir and disperse under normal pressure for 5 minutes until the material is evenly mixed. Then, apply vacuum and maintain the vacuum degree at ≤-95kPa, and stir and disperse for 30 minutes.

[0112] S2-5: Discharge: Vacuum and low-speed stirring for 10 minutes to remove bubbles, then discharge from the reactor and seal the package to obtain a stable long-lasting B component.

[0113] S3: Mixing and Curing

[0114] S3-1: Mixing: Mix component A and component B at a volume ratio of 2:1 until homogeneous. After mixing components A and B, the weight ratio of MS resin, acrylic-modified MS resin, and epoxy resin is 55:17:28. Apply the mixed adhesive to the surface of the substrate to be bonded, or into the gap between the bonding surfaces of two substrates to be bonded, to form an adhesive coating.

[0115] S3-2: Curing: The adhesive coating is cured by heating at room temperature (15-35℃) for 7 days or at 50℃ for 16 hours. During the curing process, the moisture in component A is continuously consumed. After curing, a long-lasting hybrid adhesive layer with no free water molecules inside is obtained, which combines high strength and high elasticity and is resistant to humid heat aging.

[0116] Example 2

[0117] The long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided in this embodiment are basically the same as those in Example 1. The difference lies in that the formulation components, proportions, and preparation process of the long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive provided in this embodiment are slightly different.

[0118] When preparing component A in step S1, S1-1 is as follows:

[0119] The following components were prepared according to the following mass ratios: SAX750 (Kaneka MS resin) 45 parts; MA480 (Kaneka acrylic modified MS resin) 10 parts; epoxy resin E51 25 parts; plasticizer PPG3000 8 parts; filler CCS-25 calcium carbonate 5 parts; KH540 coupling agent 1 part; K54 (epoxy catalytic curing agent 2,4,6-tris(dimethylaminomethyl)phenol) 0.38 parts; and the acidic pH adjuster consisted of citric acid 0.1 parts and deionized water 1.5 parts, with the pH value of the pH adjuster solution being approximately 1.8.

[0120] When preparing component B in step S2, S2-1 is as follows:

[0121] Prepared according to the following mass ratios: 30 parts SAX750 (MS resin); 6 parts MA480 (acrylic modified MS resin); 10 parts PPG3000 plasticizer; 6 parts filler CCS-25 nano calcium carbonate; 1 part M570 carbon black; 10 parts K54 (epoxy catalytic curing agent); 4 parts IRGANOX 1010 antioxidant; 2 parts A171 dehydrating agent; 12 parts KH540 coupling agent; 0.7 parts polyamide wax SL thixotropic agent; 2.6 parts U-130 MS catalyst.

[0122] Example 3

[0123] The long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided in this embodiment are basically the same as those in Example 1. The difference lies in that the formulation components, proportions, and preparation process of the long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive provided in this embodiment are slightly different.

[0124] When preparing component A in step S1, S1-1 is as follows:

[0125] The following components were prepared according to the following mass ratios: SAX750 (Kaneka MS resin) 45 parts; MA480 (Kaneka acrylic modified MS resin) 26 parts; epoxy resin E51 44 parts; plasticizer PPG3000 12 parts; filler CCS-25i nano calcium carbonate 18 parts; KH540 coupling agent 3 parts; K54 (epoxy catalytic curing agent 2,4,6-tris(dimethylaminomethyl)phenol) 0.66 parts; and the acidic pH adjuster consisted of citric acid 0.35 parts and deionized water 1.5 parts, with the pH value of the pH adjuster solution being approximately 1.6.

[0126] When preparing component B in step S2, S2-1 is as follows:

[0127] Prepared according to the following mass ratios: 30 parts SAX750 (MS resin); 40 parts MA480 (acrylic modified MS resin); 20 parts PPG3000 plasticizer; 30 parts CCS-25i nano calcium carbonate filler; 2 parts M570 carbon black; 20 parts K54 (epoxy catalytic curing agent); 7 parts IRGANOX 1010 antioxidant; 2 parts A171 dehydrating agent; 12 parts KH540 coupling agent; 1 part polyamide wax SL thixotropic agent; and 4.4 parts U-130 MS catalyst.

[0128] Example 4

[0129] The long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided in this embodiment are basically the same as those in Example 1. The difference lies in that the formulation components, proportions, and preparation process of the long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive provided in this embodiment are slightly different.

[0130] When preparing component A in step S1, S1-1 is as follows:

[0131] The following components were prepared according to the following mass ratios: 15 parts SAX750 (Kaneka MS resin); 15 parts SAX400 (Kaneka MS resin); 10 parts MA480 (Kaneka acrylic modified MS resin); 10 parts MA490 (Kaneka acrylic modified MS resin); 30 parts epoxy resin E51; 5 parts plasticizer PPG3000; 5 parts filler CCS-18 nano calcium carbonate; 2 parts thixotropic agent fumed silica; 2 parts KH792 coupling agent; 0.45 parts K54 (epoxy catalytic curing agent 2,4,6-tris(dimethylaminomethyl)phenol); and 0.15 parts citric acid and 2 parts deionized water as acidic pH adjusters, resulting in a pH adjuster solution with a pH of approximately 1.8.

[0132] When preparing component B in step S2, S2-1 is as follows:

[0133] Prepared according to the following mass ratios: 20 parts SAX750 (Kaneka MS resin); 20 parts SAX400 (Kaneka MS resin); 25 parts MA480 (acrylic modified MS resin); 20 parts MA490 (Kaneka acrylic modified MS resin); 20 parts PPG3000 plasticizer; 38 parts CCS-18 nano calcium carbonate filler; 2 parts M570 carbon black; 25 parts K54 (epoxy catalytic curing agent); 5 parts IRGANOX1010 antioxidant; 3 parts A171 dehydrating agent; 20 parts KH540 coupling agent; 5 parts polyamide wax SL thixotropic agent; and 6 parts U-130 MS catalyst.

[0134] Example 5

[0135] The long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided in this embodiment are basically the same as those in Example 1. The difference lies in that the formulation components, proportions, and preparation process of the long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive provided in this embodiment are slightly different.

[0136] When preparing component A in step S1, S1-1 is as follows:

[0137] The following components were prepared according to the following mass ratios: 30 parts of SAX400 (Kaneka MS resin); 15 parts of MA480 (Kaneka acrylic modified MS resin); 15 parts of MA490 (Kaneka acrylic modified MS resin); 40 parts of epoxy resin E51; 15 parts of plasticizer PPG3000; 20 parts of filler CCS-18 nano calcium carbonate; 2 parts of KH792 coupling agent; 0.60 parts of K54 (epoxy catalytic curing agent 2,4,6-tris(dimethylaminomethyl)phenol); and 0.4 parts of citric acid and 3 parts of deionized water as acidic pH adjuster, resulting in a pH adjuster solution with a pH of approximately 1.7.

[0138] When preparing component B in step S2, S2-1 is as follows:

[0139] Prepared according to the following mass ratios: 40 parts SAX400 (Kaneka MS resin); 5 parts MA480 (acrylic modified MS resin); 15 parts PPG3000 plasticizer; 19 parts CCS-18 nano calcium carbonate filler; 1 part M570 carbon black; 15 parts K54 (epoxy catalytic curing agent); 5 parts IRGANOX 1010 antioxidant; 2 parts A171 dehydrating agent; 10 parts KH540 coupling agent; 2 parts polyamide wax SL thixotropic agent; and 3 parts U-130 MS catalyst.

[0140] Example 6

[0141] The long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided in this embodiment are basically the same as those in Example 1. The difference lies in that the formulation components, proportions, and preparation process of the long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive provided in this embodiment are slightly different.

[0142] When preparing component A in step S1, S1-1 is as follows:

[0143] The following components were prepared according to the following mass ratios: 10 parts of SAX750 (Kaneka MS resin); 30 parts of SAX400 (Kaneka MS resin); 20 parts of MA490 (Kaneka acrylic modified MS resin); 50 parts of epoxy resin E51; 10 parts of plasticizer PPG3000; 25 parts of filler CCS-18 nano calcium carbonate; 2 parts of KH792 coupling agent; 0.75 parts of K54 (epoxy catalytic curing agent 2,4,6-tris(dimethylaminomethyl)phenol); and 0.4 parts of citric acid and 3 parts of deionized water as acidic pH adjusters, resulting in a pH adjuster solution with a pH of approximately 1.7.

[0144] When preparing component B in step S2, S2-1 is as follows:

[0145] Prepared according to the following mass ratios: 10 parts SAX750 (Kaneka MS resin); 30 parts SAX400 (Kaneka MS resin); 20 parts MA490 (Kaneka acrylic modified MS resin); 0 parts PPG3000 plasticizer; 4 parts CCS-18 nano calcium carbonate filler; 1 part M570 carbon black; 10 parts K54 (epoxy catalytic curing agent); 5 parts IRGANOX 1010 antioxidant; 1 part A171 dehydrating agent; 10 parts KH540 coupling agent; 2 parts polyamide wax SL thixotropic agent; and 3 parts U-130 MS catalyst.

[0146] Example 7

[0147] The long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided in this embodiment are basically the same as those in Example 1. The difference lies in that the formulation components, proportions, and preparation process of the long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive provided in this embodiment are slightly different.

[0148] When preparing component A in step S1, S1-1 is as follows:

[0149] The following components were prepared according to the following mass ratios: 35 parts of SAX750 (Kaneka MS resin); 15 parts of SAX400 (Kaneka MS resin); 5 parts of MA480 (Kaneka acrylic modified MS resin); 20 parts of epoxy resin E51; 5 parts of plasticizer PPG3000; 10 parts of filler CCS-18 nano calcium carbonate; 1 part of thixotropic agent fumed silica; 1 part of KH792 coupling agent; 1 part of KH540 coupling agent; 0.30 parts of K54 (epoxy catalytic curing agent 2,4,6-tris(dimethylaminomethyl)phenol); and 0.2 parts of citric acid and 2 parts of deionized water as acidic pH adjuster, resulting in a pH adjuster solution with a pH of approximately 1.7.

[0150] When preparing component B in step S2, S2-1 is as follows:

[0151] Prepared according to the following mass ratios: 15 parts SAX750 (Kaneka MS resin); 5 parts SAX400 (Kaneka MS resin); 25 parts MA480 (acrylic modified MS resin); 5 parts PPG3000 plasticizer; 5 parts filler CCS-18 nano calcium carbonate; 5 parts K54 (epoxy catalytic curing agent); 2 parts IRGANOX 1010 antioxidant; 0.5 parts A171 dehydrating agent; 2 parts KH540 coupling agent; and 2 parts U-130 MS catalyst.

[0152] Example 8

[0153] The long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided in this embodiment are basically the same as those in Example 1. The difference lies in that the formulation components, proportions, and preparation process of the long-lasting anti-aging high-adhesion-strength elastic hybrid adhesive provided in this embodiment are slightly different.

[0154] When preparing component A in step S1, S1-1 is as follows:

[0155] The following components were prepared according to the following mass ratios: 15 parts SAX750 (Kaneka MS resin); 35 parts SAX400 (Kaneka MS resin); 5 parts MA480 (Kaneka acrylic modified MS resin); 40 parts epoxy resin E51; 10 parts plasticizer PPG3000; 10 parts filler CCS-18 nano calcium carbonate; 1 part thixotropic agent fumed silica; 2 parts KH792 coupling agent; 1 part KH540 coupling agent; 0.60 parts K54 (epoxy catalytic curing agent 2,4,6-tris(dimethylaminomethyl)phenol); and 0.2 parts citric acid and 2 parts deionized water as acidic pH adjusters, resulting in a pH adjuster solution with a pH of approximately 1.7.

[0156] When preparing component B in step S2, S2-1 is as follows:

[0157] Prepared according to the following mass ratios: 5 parts SAX750 (Kaneka MS resin); 15 parts SAX400 (Kaneka MS resin); 45 parts MA480 (acrylic modified MS resin); 10 parts PPG3000 plasticizer; 5 parts CCS-18 nano calcium carbonate filler; 15 parts K54 (epoxy catalytic curing agent); 2 parts IRGANOX 1010 antioxidant; 0.5 parts A171 dehydrating agent; 10 parts KH540 coupling agent; and 3 parts U-130 MS catalyst.

[0158] Table 1

[0159]

[0160] Comparative Examples 1-3

[0161] The hybrid adhesives, preparation methods, and applications provided in Comparative Examples 1-3 are basically the same as those in Example 1, except that the specific materials and proportions of components A and B are shown in Table 1, and the preparation steps are as follows:

[0162] Preparation of component A:

[0163] 1. Add MS resin (or acrylic modified MS), epoxy curing agent, plasticizer, filler, antioxidant, thixotropic agent to a double planetary mixer and disperse, heat and vacuum disperse, maintain pressure ≤-95kPa, temperature 110-120℃, heat and disperse for 60-120min;

[0164] 2. After the rubber compound cools to below 30℃, add the dehydrating agent and coupling agent, stir evenly, and then vacuum stir and disperse for 30 minutes, maintaining a pressure ≤-95kPa.

[0165] 3. Vacuum and stir at low speed for 10 minutes to remove bubbles, then remove from the reactor and seal in plastic packaging.

[0166] Preparation of component B:

[0167] 1. Add epoxy resin, plasticizer, and filler to a double planetary mixer, disperse and stir under vacuum, and cool to below 30°C.

[0168] 2. Add deionized water and stir to disperse for 30 minutes.

[0169] 3. Vacuum-assisted, low-speed stirring to remove bubbles for 10 minutes.

[0170] 4. Add the catalyst, stir until homogeneous, then vacuum-stir and disperse for 15-30 minutes, maintaining a pressure ≤-95 kPa.

[0171] 5. Vacuum and stir at low speed for 10 minutes to remove bubbles, then remove from the reactor and seal in plastic packaging.

[0172] Application Test Examples

[0173] The two-component hybrid adhesives prepared in Examples 1-8 and Comparative Examples 1-3 were applied to the manufacture of power lithium battery cells under the same conditions, and tested after curing.

[0174] The performance testing methods and steps are as follows:

[0175] 1. The two-component MS hybrid adhesives prepared in Examples 1-8 and Comparative Examples 1-3 were mixed evenly with component A and component B at a volume ratio of 2:1 and coated onto the surface of a substrate of the same material to prepare a coating of the same thickness. The coating was then cured at 25°C and 50%RH for 7 days and then tested.

[0176] 2. The tensile shear strength test was conducted in accordance with the national standard GB 7124—2008 Determination of tensile shear strength of adhesives (rigid material to rigid material) with an adhesive layer thickness of 0.2 mm; the tensile strength and elongation at break were conducted in accordance with the national standard GBT 528—2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber. The comparative test results are shown in Table 2-3.

[0177] 3. Storage stability test: The samples of component A and component B were sealed and stored in an oven at 50±2℃ for 30 days, and then tensile shear strength, tensile strength and elongation at break were tested. The test results are shown in Table 4.

[0178] Table 2

[0179]

[0180] Table 3

[0181]

[0182] Table 4

[0183]

[0184] The comparative test data in Tables 2-4 above show that the two-component MS hybrid adhesives provided in Examples 1-3, while reducing costs by adding fillers, maintain high strength and high elasticity. With a strength > 9 MPa, the elongation at break is greater than 500%, and even with a further increase in bond strength to > 14 MPa, the elongation at break is still greater than 200%. Moreover, they maintain high performance after damp heat aging and high-temperature storage. In contrast, Comparative Examples 1-3 cannot maintain both high strength and high elasticity simultaneously, and the elongation decreases significantly after the strength is increased to 8 MPa. The bonding strength of each example to different substrates is also significantly higher than that of the comparative examples.

[0185] See appendix Figures 1-2 (Cureable adhesive layer of Example 3) The ternary hybrid adhesive system provided in Examples 1-8, by introducing acrylic-modified MS resin, and under the set ratio of MS resin, acrylic-modified MS resin, and epoxy resin, based on the characteristics of acrylic-modified MS resin having better compatibility with epoxy resin and also being compatible with MS resin, can serve as a transition layer between the two phase separation systems, making the microstructure after curing more uniform and dense. This prevents stress concentration caused by defects in the cured adhesive layer due to the phase separation of the epoxy system and the MS system, thereby improving the strength and density of the adhesive layer, thus enhancing the sealing performance and effectively reducing the penetration of water molecules during humid heat aging. At the same time, the rigid epoxy resin curing segments and acrylic resin curing segments can be evenly distributed in the flexible segments of the MS system, improving the adhesive bonding strength and bulk strength while maintaining high flexibility.

[0186] See appendix Figures 3-4In Comparative Example 3, after curing, the epoxy and MS systems are incompatible, resulting in phase separation at the microscopic level and an uneven microstructure. In each comparative example, increasing the proportion of acrylic-modified MS and epoxy resin improved both adhesive and bulk strength. However, due to the low proportion of MS resin, rigid segments aggregated during curing, leading to an irregular microstructure. While the higher polarity of the rigid segments improved macroscopic adhesive and bulk strength, the microscopic structural irregularities made stress concentration more likely, resulting in decreased elongation at break. This increased the likelihood of adhesive failure due to vibration and thermal expansion / contraction of the substrate.

[0187] The key feature of the embodiments of this invention is the construction of a ternary hybrid system (MS / acrylic-modified MS / epoxy), which allows for controlled hybridization of the three material systems (materials, proportions, processes, parameters) and synergistic effects among the components. Performance balance is achieved through optimization of the A / B component ratio. Acrylic-modified MS and epoxy are simultaneously introduced into the MS system for hybridization. Through a formulation design different from existing MS hybrid adhesive formulations, the ratio of MS / acrylic-modified MS / epoxy resin is optimized, resulting in a balance of high strength and high elasticity, along with good storage stability. In particular, the synergistic effect of MS resin (improving elasticity), acrylic-modified MS (improving bond strength), and epoxy resin (improving rigidity) is utilized. Addressing the issues of MS catalyst hydrolysis and MS resin pre-crosslinking, a formulation design that incorporates an acidic pH adjuster and moisture effectively inhibits pre-crosslinking of MS resin during storage and transportation, overcoming the traditional limitation of requiring strict waterproofing for MS adhesives and significantly improving long-term storage stability. By pre-adding moisture to component A (instead of relying on ambient humidity), a controllable curing speed is achieved, promoting rapid and deep curing of the adhesive layer, increasing the structural density of the adhesive layer, and ultimately obtaining an adhesive layer with high strength, high elasticity, low cost, and resistance to damp heat aging.

[0188] The long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive, its preparation method, and its application provided by the above embodiments of the present invention offer a two-component MS hybrid adhesive that is easy to produce and has good storage properties through a novel technical concept. It effectively solves the problems of compatibility between different material systems, the balance between high strength and high elasticity, and the problem that component A cannot be stored for a long period of time, thus meeting a variety of practical application needs in the industry.

[0189] It should be noted that the components, proportions, particle sizes and process parameters used in the above specific embodiments of the present invention are only examples. Other different implementation schemes obtained by making specific selections within the scope of the basic embodiments of the present invention can achieve the technical effects described in the present invention. Therefore, the present invention will not list them one by one.

[0190] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. All equivalent changes made based on the components, proportions, and processes of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a long-term anti-aging high adhesive strength elastic hybrid adhesive, characterized by, It at least includes the following steps: S1: Preparation of A component According to the mass ratio of MS resin 30-50 parts; acrylic modified MS resin 5-30 parts; epoxy resin 20-50 parts; plasticizer 0-15 parts; filler 5-25 parts; thixotropic agent 0-2 parts; coupling agent 1-3 parts; epoxy catalytic curing agent 0.3-0.75 parts; acidic pH adjuster, deionized water in appropriate amount, MS resin, acrylic modified MS resin, epoxy resin, plasticizer, filler, thixotropic agent are added to the double planetary stirring disperser respectively and stirred uniformly, vacuumized, heated to 110-120℃, constant temperature, high speed dispersion stirring dehydration to obtain dehydrated material; The dehydrated material is kept in vacuum, the temperature is lowered to below 30℃, the coupling agent and the epoxy catalytic curing agent are added, stirred uniformly under normal pressure, then vacuum is kept, heated to 90-100℃, constant temperature, high speed dispersion stirring, so that the active groups between the coupling agent and MS resin, acrylic modified MS resin, epoxy resin, filler, thixotropic agent fully react, to obtain resin base material, and the temperature is lowered to below 30℃; The pH adjuster solution with pH value not greater than 2 prepared by deionized water and acidic pH adjuster is added to the resin base material, stirred and dispersed uniformly under normal pressure, vacuumized, low speed stirring to remove bubbles, discharged from the kettle and sealed for packaging, to obtain long-acting type A component with weak acidity and high storage stability; S2: Preparation of B component According to the mass ratio of MS resin 20-40 parts; acrylic modified MS resin 5-45 parts; plasticizer 0-30 parts; filler 5-40 parts; epoxy catalytic curing agent 10-25 parts; antioxidant 2-10 parts; water removing agent 0.5-3 parts; coupling agent 2-20 parts; thixotropic agent 0-5 parts; MS catalyst 2-6 parts, MS resin, acrylic modified MS resin, plasticizer, filler, antioxidant, thixotropic agent are added to the double planetary stirring disperser respectively, stirred uniformly, vacuumized, heated to 110-120℃, constant temperature, high speed stirring and dispersion dehydration, to obtain dehydrated material; The dehydrated material is cooled to below 30℃ under vacuum, then the water removing agent is added, stirred and dispersed under normal pressure until the material is mixed uniformly, vacuum is kept, the coupling agent, epoxy catalytic curing agent and MS catalyst are added, stirred and dispersed under normal pressure until the material is mixed uniformly, vacuumized, low speed stirring to remove bubbles, discharged from the kettle and sealed for packaging, to obtain long-acting type B component with high storage stability.

2. The method of claim 1, wherein the long-term anti-aging high adhesive strength elastic hybrid adhesive is prepared by mixing a polyurethane prepolymer, a polyol, a crosslinking agent, and a catalyst. It also includes the following steps: S3: Mixing and curing After the A component and the B component are mixed uniformly according to the volume ratio of 2:1, they are coated on the surface of the substrate to be bonded or in the gap between the bonding surfaces of two substrates to form an adhesive coating; The adhesive coating is cured at room temperature for not less than 5 days or heated at 50℃ for not less than 10 hours, the moisture in the A component is continuously consumed during the curing process, and a long-acting hybrid adhesive layer with high strength and high elasticity and resistance to wet heat aging is obtained after the curing is completed.

3. The method for preparing the long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive according to claim 1 or 2, characterized in that, The step S1 specifically includes the following steps: S1-1: Prepare MS resin, acrylic modified MS resin, epoxy resin, plasticizer, filler, thixotropic aid, coupling agent, epoxy catalytic curing agent, acidic pH regulator, deionized water respectively; S1-2: Prepare dehydrated material: add MS resin, acrylic modified MS resin, epoxy resin, plasticizer, filler, thixotropic aid into double planetary stirring dispersion machine respectively, after stirring for 30 min under normal pressure and 25℃, vacuumize and keep vacuum degree ≤-95kPa, heat to 110-120℃, keep constant temperature, high speed dispersion stirring dehydration for 2 hours, then get dehydrated material; S1-3: Mutual reaction: keep dehydrated material vacuum degree ≤-95kPa, drop temperature to below 30℃, add coupling agent and epoxy catalytic curing agent into dehydrated material, after stirring for 30 min under normal pressure, keep vacuum degree ≤-95kPa, heat to 90-100℃, keep constant temperature, high speed dispersion stirring, make coupling agent and active groups of MS resin, acrylic modified MS resin, epoxy resin, filler, thixotropic aid fully react with each other for 1.5 hours, make resin completely coat filler surface, get resin base material, keep vacuum degree ≤-95kPa, drop temperature to below 30℃; S1-4: Prepare pH regulator solution: take deionized water which is 1.5-2.0 times of water amount required for complete hydrolysis reaction of MS resin and coupling agent, dissolve appropriate amount of acidic pH regulator in deionized water, get pH regulator solution with pH no more than 2; S1-5: Adjust pH of system: add pH regulator solution into resin base material, stir and disperse for 30 min under normal pressure; S1-6: Discharge: vacuumize, stir and degas for 10 min at low speed, discharge from reactor and seal for packaging, get long-acting type A component which can be stored stably.

4. The preparation method of the long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive according to claim 1, characterized in that, The step S2 specifically comprises the following steps: S2-1: Prepare MS resin, acrylic modified MS resin, plasticizer, filler, epoxy catalytic curing agent, antioxidant, water removing agent, coupling agent, thixotropic aid, MS catalyst respectively; S2-2: Prepare dehydrated material: add MS resin, acrylic modified MS resin, plasticizer, filler, antioxidant, thixotropic aid into double planetary stirring dispersion machine respectively, after stirring for 30 min under normal pressure and 25℃, vacuumize and keep vacuum degree ≤-95kPa, heat to 110-120℃, keep constant temperature, high speed stirring and dispersion dehydration for 2 hours, get dehydrated material, keep dehydrated material vacuum degree ≤-95kPa and drop temperature to below 30℃; S2-3: Water removal: add water removing agent into dehydrated material in vacuum state, stir and disperse for 10 min under normal pressure until material is mixed uniformly, vacuumize and keep vacuum degree ≤-95kPa, stir and disperse for 10 min again, remove water sufficiently; S2-4: Additive mixing: add coupling agent, epoxy catalytic curing agent, MS catalyst into dehydrated material after water removal, stir and disperse for 5 min under normal pressure until material is mixed uniformly, vacuumize and keep vacuum degree ≤-95kPa, stir and disperse for 30 min; S2-5: discharging: vacuum low-speed stirring to remove bubbles for 10 min, discharging from the reactor and sealing for packaging, to obtain long-acting B component for stable storage.

5. The preparation method of the long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive according to claim 2, characterized in that, The step S3 specifically comprises the following steps: S3-1: mixing: mixing A component and B component uniformly at a volume ratio of 2:1, and then coating on the surface of the substrate to be bonded or in the gap between the bonding surfaces of two substrates to be bonded to form an adhesive coating; S3-2: curing: curing the adhesive coating at room temperature for not less than 5 days or heating at 50℃ for not less than 10 hours, continuously consuming the water in A component during the curing process, and obtaining a long-acting hybrid adhesive layer with no free water molecules in the interior, high strength, high elasticity and resistance to wet heat aging after curing.

6. The preparation method of the long-lasting, anti-aging, high-adhesion-strength elastic hybrid adhesive according to claim 5, characterized in that, In the long-acting hybrid adhesive layer after mixing and curing of A component and B component: The weight ratio of MS resin, acrylic modified MS resin and epoxy resin is (40-60):(10-40):(20-35), and the ratio of the total weight of MS resin and acrylic modified MS resin to the weight of epoxy resin is ≥2; The proportion of acrylic modified MS resin in the total weight of MS resin and acrylic modified MS resin is ≥15%; The mass proportion of filler is ≤20%; The mass ratio of MS catalyst to the sum of MS resin and acrylic modified MS resin is 1%-3%; The mass ratio of epoxy resin curing agent to epoxy resin is 15%-25%; The deionized water in the pH regulator solution is completely consumed in the curing reaction.

7. The preparation method of the long-acting anti-aging high-adhesion-strength elastic hybrid adhesive according to claim 6, characterized in that: The MS resin is at least one or a mixture of multiple of the following: Zhonghua Resin SAX750, SAX400, SAX260, Ruoyang Antai TUPS400T, TUPS303T and TUPS350D; The acrylic modified MS resin is at least one or a mixture of multiple of the following: Zhonghua Resin MA480, MA490 and MA602; The epoxy resin is E51 or E44; The MS catalyst is at least one or a mixture of multiple of the following: stannous octoate, dibutyltin dilaurate, dioctyltin dilaurate, di-n-butylbis(acetylacetonato)tin and 1,3-dilauryloxy-1,1,3,3-tetrabutyldistannoxane; The plasticizer is a polyether polyol with a molecular weight greater than 1000; The epoxy catalytic curing agent is 2,4,6-tris(dimethylaminomethyl)phenol or tert-butyl phenol; The antioxidant is at least one of the following: IRGANOX 1010, IRGANOX 1076 and IRGANOX 1135; The water removal agent is one of the following: vinyltrimethoxysilane, methylvinyl dimethoxysilane or vinyltris(2-methoxyethoxy)silane; The coupling agent is at least one or a mixture of multiple of the following: KH-540, KH-550 and KH-792; The filler is at least one or a mixture of multiple of the following: CCS-18, CCS-25 and CCS-25i. The thixotropic aid is one or a mixture of both of fumed silica or polyamide wax.

8. The method of claim 6, wherein the long-term anti-aging high adhesive strength elastic hybrid adhesive is prepared by the method of any one of claims 1 to 8. The weight ratio of the MS resin, the acrylic modified MS resin, and the epoxy resin is 55:17:

28. The acidic pH adjuster of the component A is citric acid or succinic acid, and the amount of the addition is such that the pH of the pH adjuster solution is 1-2, and the mass ratio is not more than 3% of the weight of the filler in the component A.

9. A long-lasting anti-aging high adhesive strength elastic hybrid adhesive, characterized by, It is prepared by the method of any one of claims 1-8.

10. The long-term anti-aging high adhesive strength elastic hybrid adhesive of claim 9 for use in the manufacture of power battery cells.

Images