A high heat-resistant sealing hole resin composition for a graphite bipolar plate of a hydrogen fuel cell and its application

Abstract

The present invention discloses a high heat-resistant hole-sealing resin composition for a graphite bipolar plate of a hydrogen fuel cell and its application. The resin composition of the present invention comprises a resin mixture and a curing agent mixture, and the weight ratio between the two is 100:(80-100). The resin mixture comprises: 70-90 wt% of an epoxy resin, 5-30 wt% of a diluent, and 0-2 wt% of an auxiliary agent; the curing agent mixture comprises 90-99.5 wt% of an acid anhydride curing agent, 0.1-5 wt% of an accelerator, and 0-5 wt% of an auxiliary agent. The resin mixture provided by the present invention is used for plugging micropores of a graphite bipolar plate of a hydrogen fuel cell. After high-temperature curing, it has excellent heat-resistant performance, its glass transition temperature is greater than 95 °C, and at the same time, it has the characteristics of low viscosity and long operation period, and can realize cyclic operation and use, thereby reducing the generation of waste resin to achieve the purpose of environmental protection and cost reduction.

Description

Technical Field

[0001] The present invention relates to a high heat-resistant hydrogen fuel cell graphite bipolar plate sealing hole resin composition and its application, belonging to the technical field of hydrogen fuel cells. Background Art

[0002] Hydrogen energy has received extensive attention due to its advantages such as pollution-free, high calorific value, and renewable. With the development of electrolytic water hydrogen production technology in recent years and the continuous maturity of hydrogen storage and transportation technologies, the application prospect of hydrogen energy is more extensive. The proton exchange membrane hydrogen fuel cell is one of its important application fields, which can directly convert the chemical energy in hydrogen into electrical energy through an electrochemical reaction, and the theoretical conversion efficiency can reach 85-90%.

[0003] In a proton exchange membrane hydrogen fuel cell, the bipolar plate is an important component of the fuel cell stack. The weight and volume of the bipolar plate account for about 80% of the proton exchange membrane fuel cell, and the cost is about 50%. The main functions of the bipolar plate are to isolate and distribute the oxidant and fuel, conduct current, support the membrane electrode, and regulate the internal temperature of the stack. According to different matrix materials, bipolar plates are mainly divided into metal bipolar plates, graphite bipolar plates, and composite graphite bipolar plates. Among them, graphite bipolar plates have the advantages of high conductivity, high stability, and easy processing.

[0004] In a graphite bipolar plate, after the original graphite plate is sliced by high-temperature calcination, there are various fine holes inside. These holes not only affect the airtightness and corrosion resistance of the bipolar plate, but also reduce its mechanical properties. Through resin impregnation filling and heating curing, the resin can block the micro holes and form a composite structure with graphite, which can solve problems such as airtightness and mechanical strength. Generally, low-viscosity epoxy resin compositions often have a relatively low glass transition temperature and are difficult to meet the heat resistance requirements of high-performance fuel cells. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that in the prior art, the glass transition temperature of the resin used for sealing the holes of the graphite bipolar plate is generally relatively low. When the fuel cell operates under instantaneous high temperature or long-term over-temperature conditions, the resin transforms from a glassy state to a rubbery state, resulting in the softening of the resin in the micropores, the separation of the resin from the inner wall of the holes of the graphite plate, and the emergence of new gaps, which affects the airtightness and mechanical strength of the fuel cell.

[0006] To solve the above technical problems, the present invention provides a high heat-resistant sealing hole resin composition for a graphite bipolar plate of a hydrogen fuel cell. The resin composition comprises a resin mixture and a curing agent mixture, and the weight ratio of the resin mixture to the curing agent mixture is 100:(80 - 100); wherein, the resin mixture comprises 70 - 90 wt% of an epoxy resin, 5 - 30 wt% of a diluent, and 0 - 2 wt% of an auxiliary agent; the curing agent mixture comprises 90 - 99.5 wt% of an acid anhydride curing agent, 0.1 - 5 wt% of an accelerator, and 0 - 5 wt% of an auxiliary agent; the diluent is a combination of a glycerol ether diluent and an alcohol diluent;

[0007] The resin composition needs to meet the following properties:

[0008] 1) The initial mixing viscosity at 25°C is ≤300 mPa·s;

[0009] 2) The gel time of the resin composition at 160°C is ≤5 min;

[0010] 3) After the resin composition is cured at a high temperature of 140 - 160°C for 1 - 3 h, the glass transition temperature >95°C; and

[0011] 4) The surface tension of the resin composition <30 mN / m.

[0012] Preferably, the epoxy resin is selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, hydrogenated bisphenol A epoxy resin, phenolic epoxy resin, alicyclic epoxy resin, polyfunctional epoxy resin, brominated epoxy resin, and flexible long-chain toughened epoxy resin, and the epoxy equivalent of the epoxy resin is 100 - 400 g / equivalent;

[0013] And / or, the auxiliary agent includes at least one of a coupling agent, an antifoaming agent, a toughening agent, a thixotropic agent, a wetting agent, an antioxidant, and a leveling agent.

[0014] More preferably, the epoxy resin is selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, and alicyclic epoxy resin, and the epoxy equivalent of the epoxy resin is 200 - 300 g / equivalent.

[0015] Preferably, the glycerol ether diluent is selected from at least one of benzyl glycidyl ether, butyl glycidyl ether, octyl glycidyl ether, C12 - C14 alkyl glycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, dipropylene glycol diglycidyl ether, 1,2-cyclohexanediol diglycidyl ether, 1,4-cyclohexanediol diglycidyl ether, and pentaerythritol tetraglycidyl ether;

[0016] The alcohol diluent is selected from at least one of benzyl alcohol, low molecular weight polypropylene glycol with a molecular weight ≤ 2000, and low molecular weight polyethylene glycol with a molecular weight ≤ 500.

[0017] Preferably, the anhydride curing agent is selected from at least one of phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, trimellitic anhydride, C8-C9 alkenyl succinic anhydride, dodecenyl succinic anhydride, methyl nadic anhydride, hydrogenated methyl nadic anhydride, tung oil anhydride, maleic anhydride, glutaric anhydride, and methylene tetrahydrophthalic anhydride.

[0018] More preferably, the anhydride curing agent is selected from at least one of phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, and hydrogenated methyl nadic anhydride.

[0019] Preferably, the accelerator is selected from at least one of o-hydroxybenzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, trioleate of 2,4,6-tris(dimethylaminomethyl)phenol, benzyldimethylamine, 1,8-diazabicyclo(5,4,0)-7-undecene, 1,8-diazabicyclo(5,4,0)-7-undecene octoate, 1,8-diazabicyclo(5,4,0)-7-undecene lactate, 1,8-diazabicyclo(5,4,0)-7-undecene phenolate, 1,8-diazabicyclo(5,4,0)-7-undecene p-toluenesulfonate, 1,8-diazabicyclo(5,4,0)-7-undecene phthalate, 1,5-diazabicyclo[4.3.0]-5-nonene, benzyltriethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium bromide, tetraphenylphosphonium bromide, tetrabutylphosphonium acetate, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-phenyl-2-methylimidazole, 1-methylimidazole, 2-methylimidazole, 2,4-dimethylimidazole, and 2,6-di-tert-butyl-p-cresol.

[0020] More preferably, the accelerator is selected from at least one of 2,4,6-tris(dimethylaminomethyl)phenol, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-phenyl-2-methylimidazole, 1-methylimidazole, 2-methylimidazole, 2,4-dimethylimidazole, and 2,6-di-tert-butyl-p-cresol.

[0021] In some embodiments of the present invention, the resin composition comprises a resin mixture and a curing agent mixture with a weight ratio of 100:80-100, wherein the resin mixture contains 70-80 parts of bisphenol A epoxy resin, 10-20 parts of alicyclic epoxy resin, 3-5 parts of 1,4-butanediol diglycidyl ether, 3-10 parts of polypropylene glycol, 0.1-0.3 parts of defoamer, and 0.05-0.2 parts of coupling agent; the curing agent mixture contains 90-99 parts of methyltetrahydrophthalic anhydride and 1-10 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0022] In still other embodiments of the present invention, the resin composition comprises a resin mixture and a curing agent mixture with a weight ratio of 100:80-100, wherein the resin mixture contains 40-60 parts of bisphenol A epoxy resin, 30-40 parts of bisphenol F epoxy resin, 9-11 parts of C12-C14 alkyl glycidyl ether, 4-6 parts of polyethylene glycol, 0.05-0.2 parts of defoamer, and 0.1-0.3 parts of coupling agent; the curing agent mixture contains 85-95 parts of methyltetrahydrophthalic anhydride, 5-15 parts of phthalic anhydride, and 0.5-2 parts of 2,4,6-tris(dimethylaminomethyl)phenol.

[0023] The present invention also provides the application of the above resin composition in sealing holes of graphite bipolar plates. The graphite bipolar plate is the graphite bipolar plate used in hydrogen fuel cells.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The high heat-resistant resin composition for sealing holes of graphite bipolar plates in hydrogen fuel cells provided by the present invention has a high glass transition temperature after heat curing, can meet the temperature resistance requirements of graphite bipolar plates in proton exchange membrane fuel cells under instantaneous high temperature or long-term over-temperature operating conditions, and ensure that the resin will not soften and new pores will not appear, thus affecting airtightness.

[0026] 2. The high heat-resistant resin composition for sealing holes of graphite bipolar plates in hydrogen fuel cells provided by the present invention not only has the characteristic of high heat resistance, but also has the characteristics of low mixing viscosity, good fluidity, and long operable time. Under room temperature impregnation conditions, it can avoid the resin from being difficult to impregnate into the micro holes in the graphite plate due to too fast viscosity rise, so as to achieve the purpose of recycling, reduce the generation of resin waste, and be environmentally friendly while reducing costs.

[0027] 3. The high heat-resistant resin composition for sealing holes of graphite bipolar plates in hydrogen fuel cells provided by the present invention has excellent chemical resistance in deionized water, 50% ethylene glycol solution, dilute sulfuric acid and hydrofluoric acid combined acidic solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the viscosity growth curve of the resin composition in Example and Comparative Example. DETAILED DESCRIPTION

[0029] To make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0030] In the following examples, the materials, reagents, etc. used, unless otherwise specified, are conventional commercially available products.

[0031] Example 1

[0032] A high-heat-resistant hydrogen fuel cell graphite bipolar plate sealing resin composition comprises a resin mixture and a curing agent mixture, wherein the resin mixture comprises 74.7 parts of bisphenol A epoxy resin, 16 parts of alicyclic epoxy resin, 4 parts of 1,4-butanediol diglycidyl ether, 5 parts of polypropylene glycol with a molecular weight of 400, 0.2 parts of a defoaming agent, and 0.1% of a coupling agent; and the curing agent mixture comprises 99 parts of methyltetrahydrophthalic anhydride and 1 part of 1-cyanoethyl-2-ethyl-4-methylimidazole.

[0033] The preparation method of the above resin composition is:

[0034] (1) After accurately weighing bisphenol A epoxy resin, alicyclic epoxy resin, 1,4-butanediol diglycidyl ether, and polypropylene glycol according to the proportion, add them to a container, turn on the stirrer, and stir continuously at 300 rpm for 15 minutes. After stirring, reduce the stirrer speed to 100 rpm, and then add the defoaming agent and coupling agent dropwise while stirring. After the defoaming agent and coupling agent are added, continue stirring at 300 rpm for 15 minutes. Stop stirring after the resin is evenly mixed, and vacuum degas for later use.

[0035] (2) Accurately weigh methyltetrahydrophthalic anhydride, pour it into a container, turn on the stirrer, set the speed to 200 rpm, and add 1-cyanoethyl-2-ethyl-4-methylimidazole dropwise while stirring. After the addition is completed, set the stirrer speed to 300 rpm and continue stirring for 15 minutes. Stop stirring after the curing agent is evenly mixed, and vacuum degas for later use.

[0036] (3) The resin mixture of step (1) and the curing agent mixture of step (2) are evenly mixed in a ratio of 100:90, and a high heat-resistant hydrogen fuel cell graphite bipolar plate sealing resin composition is obtained after degassing.

[0037] Example 2

[0038] A high heat-resistant sealing hole resin composition for graphite bipolar plates of hydrogen fuel cells, comprising a resin mixture and a curing agent mixture. Among them, the resin mixture contains 50 parts of bisphenol A epoxy resin, 35 parts of bisphenol F epoxy resin, 9.7 parts of C12-C14 alkyl glycidyl ether, 5 parts of polyethylene glycol 200 (with a molecular weight of 190-210), 0.1 part of defoaming agent, and 0.2 part of coupling agent; the curing agent mixture contains 89 parts of methyl tetrahydrophthalic anhydride, 10 parts of phthalic anhydride, and 1 part of 2,4,6-tris(dimethylaminomethyl)phenol.

[0039] The preparation method of the above resin composition is as follows:

[0040] (1) Weigh accurately bisphenol A epoxy resin, bisphenol F epoxy resin, C12-C14 alkyl glycidyl ether, and polyethylene glycol according to the proportion, add them to a container, start the stirrer, and continuously stir at a speed of 300 rpm for 15 min. After the stirring is completed, reduce the stirrer speed to 100 rpm, then add the defoaming agent and coupling agent dropwise while stirring. After the defoaming agent and coupling agent are added dropwise, continue to stir at a speed of 300 rpm for 15 min. Stop stirring after the resin is evenly mixed, and vacuum degas for standby.

[0041] (2) Weigh accurately methyl tetrahydrophthalic anhydride, pour it into the reaction kettle, and add flaky phthalic anhydride. Start the stirrer, set the speed to 300 rpm, heat up to 120 °C while stirring. After the flaky phthalic anhydride is completely dissolved, cool down to 60 °C, and add 2,4,6-tris(dimethylaminomethyl)phenol dropwise while stirring. After the addition is completed, set the stirrer speed to 400 rpm, continuously stir for 15 min, then cool down to room temperature, and vacuum degas for standby.

[0042] (3) Mix the resin mixture in step (1) and the curing agent mixture in step (2) evenly according to a ratio of 100:90, and obtain a high heat-resistant sealing hole resin composition for graphite bipolar plates of hydrogen fuel cells after degassing.

[0043] Comparative Example 1

[0044] A sealing hole resin composition for graphite bipolar plates of hydrogen fuel cells, comprising a resin mixture and a curing agent mixture. Among them, the resin mixture contains 10 parts of bisphenol A epoxy resin, 61.9 parts of bisphenol F epoxy resin, 13 parts of 1,4-butanediol diglycidyl ether, 15 parts of polypropylene glycol diglycidyl ether, and 0.1 part of defoaming agent; the curing agent mixture contains 99 parts of methyl tetrahydrophthalic anhydride and 1 part of 1,8-diazabicyclo(5,4,0)-7-undecene lactate.

[0045] The preparation method of the above resin composition is as follows:

[0046] (1) Weigh bisphenol A epoxy resin, bisphenol F epoxy resin, 1,4-butanediol diglycidyl ether, and polypropylene glycol diglycidyl ether accurately according to the proportion, add them to a container, start the stirrer, and continuously stir at a speed of 300 rpm for 15 min. After stirring, reduce the stirrer speed to 100 rpm, then add the defoaming agent dropwise while stirring. After the defoaming agent is added dropwise, continuously stir at a speed of 300 rpm for 15 min. Stop stirring after the resin is evenly mixed, and perform vacuum defoaming for standby.

[0047] (2) Weigh methyltetrahydrophthalic anhydride accurately, pour it into the container, start the stirrer, set the speed to 200 rpm, add 1,8-diazabicyclo(5,4,0)-7-undecene lactate dropwise while stirring. After the addition is completed, set the stirrer speed to 300 rpm and continuously stir for 15 min. Stop stirring after the curing agent is evenly mixed, and perform vacuum defoaming for standby.

[0048] (3) Mix the resin mixture in step (1) and the curing agent mixture in step (2) evenly according to the ratio of 100:90, and obtain the sealing hole resin composition for the graphite bipolar plate of the hydrogen fuel cell after defoaming.

[0049] Comparative Example 2

[0050] A sealing hole resin composition for the graphite bipolar plate of a hydrogen fuel cell, comprising a resin mixture and a curing agent mixture. Among them, the resin mixture contains 78.5 parts of phenolic epoxy resin, 9 parts of 1,6-hexanediol diglycidyl ether, 11.9 parts of polypropylene glycol diglycidyl ether, 0.1 part of defoaming agent, and 0.5 part of coupling agent; the curing agent mixture contains 94.2 parts of methyltetrahydrophthalic anhydride, 3.2 parts of carboxyl-terminated polybutadiene, 2.5 parts of 2,4-dimethylimidazole, and 0.1 part of 2,6-di-tert-butyl-p-cresol.

[0051] The preparation method of the above resin composition is as follows:

[0052] (1) Weigh phenolic epoxy resin, 1,6-hexanediol diglycidyl ether, and polypropylene glycol diglycidyl ether accurately according to the proportion, add them to a container, start the stirrer, and continuously stir at a speed of 300 rpm for 15 min. After stirring, reduce the stirrer speed to 100 rpm, then add the defoaming agent and coupling agent dropwise while stirring. After the defoaming agent and coupling agent are added dropwise, continuously stir at a speed of 300 rpm for 15 min. Stop stirring after the resin is evenly mixed, and perform vacuum defoaming for standby.

[0053] (2) Weigh methyltetrahydrophthalic anhydride and carboxyl-terminated polybutadiene accurately, pour them into a glass reaction kettle, add 2,4-dimethylimidazole, heat the reaction kettle to 95 - 100 °C, stir while heating, set the rotation speed at 200 rpm. After 2,4-dimethylimidazole is completely dissolved, add 2,6-di-tert-butyl-p-cresol, continue heating and stirring. After 2,6-di-tert-butyl-p-cresol is completely dissolved, cool down to 25 - 35 °C, add the coupling agent dropwise while stirring. After the dropping is completed, set the rotation speed of the stirrer at 300 rpm, continue stirring for 15 min. After the curing agent is mixed evenly, stop stirring and carry out vacuum defoaming for standby.

[0054] (3) Mix the resin mixture in step (1) and the curing agent mixture in step (2) evenly according to the ratio of 100:90, and obtain the resin composition for sealing holes of the graphite bipolar plate of the hydrogen fuel cell after defoaming.

[0055] Performance test:

[0056] The viscosity and heat resistance performance of the resin compositions in the above-mentioned examples and comparative examples were tested respectively. The results are shown in Table 1. It can be seen from Table 1 that the glass transition temperature and heat distortion temperature of the resin composition provided by the examples of the present invention are high, and it has good heat resistance. After the resin compositions in the above-mentioned examples and comparative examples were made into resin specimens, the mass change (mass increase rate) of the resin specimens was detected after boiling in different media at 96 °C for 1000 h, and the results are shown in Table 2. The density change of the resin specimens was detected after boiling in different media at 96 °C for 1000 h, and the results are shown in Table 3. The hardness change of the resin specimens was detected after boiling in different media at 96 °C for 1000 h, and the results are shown in Table 4. The increase of conductivity and ion precipitation of the resin specimens were detected after boiling in deionized water at 96 °C for 1000 h, and the results are shown in Table 5. It can be seen from Tables 2 - 5 that the resin composition provided by the examples of the present invention has good chemical corrosion resistance and acid resistance. In the measured media, compared with the comparative examples, the mass increase rate of the resin composition provided by the examples is lower than that of the comparative examples, and the increase amount of its conductivity and the precipitation amount of Cl - ions are lower than those of the comparative examples, and the overall performance is better than that of the comparative examples. Among them, the acid combination solution in Tables 2 - 4 refers to the acidic solution composed of dilute sulfuric acid and hydrofluoric acid (hydrofluoric acid concentration 0.1 mmol / L).

[0057] Table 1 Resin viscosity and heat resistance performance

[0058]

[0059] In Table 1, X represents poor sealing effect and O represents good sealing effect; the sealing effect is detected by the PT penetration test method. The PT penetration test method is a non-destructive testing technique based on the principle of liquid capillary action. In this method, a penetrant containing dye (in this test, the sealing resin composition is used as the penetrant) is applied to penetrate into the micropores of the graphite bipolar plate, and then the penetrant in the micropores is adsorbed onto the surface of the bipolar plate by the developer, and the imaging result is observed under a certain light source (such as black light or white light) to evaluate the sealing effect. If there are obvious penetrant traces on the surface of the bipolar plate, it indicates that the sealing effect of the resin composition is poor; otherwise, it indicates good sealing effect.

[0060] Table 2 Mass increase rate of resin specimens after boiling in different media at 96°C for 1000 h

[0061]

[0062] Table 3 Density change of resin specimens after boiling in different media at 96°C for 1000 h

[0063]

[0064] Table 4 Hardness change of resin specimens after boiling in different media at 96°C for 1000 h

[0065]

[0066] Table 5 Ion precipitation of resin specimens after boiling in deionized water at 96°C for 1000 h

[0067]

[0068] In Example 1 of the present invention, a low-viscosity alicyclic epoxy resin is selected and compounded with a bisphenol A-type epoxy resin to reduce the dosage of the diluent, and it is paired with an imidazole accelerator with better heat resistance. While retaining the relatively low initial viscosity of the system, the curing crosslinking density of the resin is increased, thereby increasing its glass transition temperature. When the glass transition temperature of the resin is higher, the material not only exhibits better heat resistance, but also the chemical resistance of the resin cured product in different media is more excellent. The main reason is that the higher the three-dimensional network crosslinking density of the resin, the less likely the small-molecule chemical medium is to penetrate into the interior of the resin cured product, thereby reducing the influence on the resin cured product; another reason is that when the glass transition temperature of the resin is higher than the medium temperature, the resin cured product has not yet changed from the glassy state to the high elastic state, and the activity of the molecular chain segments inside the resin cured product is relatively small, making it easier to resist the influence of the medium. In Example 2, the viscosity of the system is reduced by compounding bisphenol F-type epoxy resin and bisphenol A-type epoxy resin, the dosage of the diluent is reduced, and the curing agent is selected as a compound of tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride to increase the glass transition temperature.

[0069] Comparing Comparative Example 1 with Comparative Example 2, although the initial mixing viscosities of the two are not very different, the sealing effect of Comparative Example 2 is better than that of Comparative Example 1. The main reason is that the viscosity increase rate of the resin in Comparative Example 1 at room temperature is too slow (as Figure 1 shown), resulting in too low viscosities of the resin on the surface of the graphite plate and in the holes inside the graphite plate when the impregnation is completed. Since the resin needs to reach a certain temperature condition for gel curing, during the curing heating stage, the low-viscosity resin is likely to drip from the surface of the graphite plate, leading to poor sealing effect.

[0070] As mentioned above, only the preferred embodiments of the present invention are provided, and there is no restriction on the present invention in any formal or substantial form. It should be noted that for those of ordinary skill in the art, several improvements and supplements can still be made without departing from the present invention, and these improvements and supplements should also be regarded as within the protection scope of the present invention.

Claims

1. A high heat-resistant hydrogen fuel cell graphite bipolar plate sealing resin composition, characterized in that: The resin composition comprises a resin mixture and a curing agent mixture, wherein the weight ratio of the resin mixture to the curing agent mixture is 100:(80-100); the resin mixture comprises 40-60 parts of bisphenol A epoxy resin, 30-40 parts of bisphenol F epoxy resin, 9-11 parts of C12-C14 alkyl glycidyl ether, 4-6 parts of polyethylene glycol, 0.05-0.2 parts of a defoaming agent, and 0.1-0.3 parts of a coupling agent; the curing agent mixture comprises 85-95 parts of methyltetrahydrophthalic anhydride, 5-15 parts of phthalic anhydride, and 0.5-2 parts of 2,4,6-tris(dimethylaminomethyl)phenol; The resin composition must meet the following properties: 1) Initial mixed viscosity ≤ 300mPa.s at 25℃; 2) The gel time of the resin composition at 160°C is ≤ 5 minutes; 3) The resin composition has a glass transition temperature greater than 95°C after being cured at a temperature of 140°C to 160°C for 1 to 3 hours; and 4) The surface tension of the resin composition is less than 30 mN / m.

2. Use of the resin composition according to claim 1 in sealing graphite bipolar plates.

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