Impregnation resin and preparation method and application thereof

Abstract

The present invention provides an impregnating resin and a preparation method and application thereof, belonging to the technical field of resin materials. In terms of mass percentage, the impregnating resin provided by the present invention comprises the following components: 0-15% epoxy acrylate, 40-50% monofunctional acrylate, 20-50% bifunctional acrylate, and 5-15% multifunctional acrylate. The impregnating resin provided by the present invention has the characteristics of good heat resistance, strong corrosion resistance, good penetration, strong adhesion, etc. The results of the embodiment show that the Tg of the impregnating resin provided by the present invention exceeds 147°C, and it has excellent corrosion resistance to acids, alkalis, water and refrigerants, and can ensure the safety and stability of the battery stack during long-term operation.

Description

Technical Field

[0001] The invention relates to the technical field of resin materials, and in particular to an impregnating resin and a preparation method and application thereof. Background Art

[0002] The increasingly serious energy shortage and environmental pollution in the world today have attracted much attention. Energy and environment have become key factors restricting the sustainable development strategy of human society, and the search for clean new energy is urgent.

[0003] Fuel cells generate electricity through the electrochemical reaction of hydrogen and oxygen. The reaction product is water, which is non-polluting to the environment. Fuel cells meet the requirements of sustainable development with their high efficiency and cleanness, and therefore receive more and more attention at home and abroad. Compared with internal combustion engines, fuel cells are a device that continuously converts the chemical energy in the continuously supplied fuel and oxidant into electrical energy. Since they are not limited by the Carnot cycle, they are highly efficient, and have low pollution and noise.

[0004] As a connecting component of a single cell in a proton exchange membrane fuel cell stack, the bipolar plate mainly plays the role of isolating the gas communication between cells, distributing fuel and oxidant, supporting the membrane electrode and connecting the single cells in series to form an electronic circuit. The cost of the bipolar plate can account for 45% of the total cost, and the weight accounts for 80% of the total weight. Therefore, reducing the cost and weight of the bipolar plate will greatly promote the commercialization of fuel cells. In recent years, due to its low cost, good corrosion resistance, light weight, and simple preparation process, graphite composites have become one of the most promising fuel cell bipolar plate materials.

[0005] Graphite bipolar plates are divided into machined graphite plates (CNC processing technology) and molded graphite plates according to different processing techniques. At present, graphite bipolar plates usually use machined graphite, but this process is complicated to produce, the processing cycle is long, the processing cost accounts for a high proportion of the total cost of the bipolar plate, and the cost reduction space is limited. Its cost is 5 to 8 times that of molded or flexible graphite plates, and its thickness is thicker than molded or flexible graphite plates. Therefore, molded graphite plates and flexible graphite plates have huge advantages in terms of cost, production cycle, production efficiency and lightweight volume, and are the direction of hydrogen fuel cells. The most important raw material impregnated resin material used for molded graphite plates and flexible graphite plates is the basis for providing the strength, air tightness and corrosion resistance of their graphite plates.

[0006] The foreign impregnation resins currently used have serious defects such as insufficient heat resistance, poor corrosion resistance, and precipitation during the operation of the fuel cell stack. Summary of the invention

[0007] The purpose of the present invention is to provide an impregnating resin and a preparation method and application thereof. The impregnating resin provided by the present invention has good heat resistance and corrosion resistance, and can ensure the safety and stability of the fuel cell stack during long-term operation.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0009] The present invention provides an impregnating resin, which comprises the following components in terms of mass percentage:

[0010]

[0011] Preferably, the epoxy acrylate includes at least one of bisphenol A epoxy acrylate and novolac epoxy acrylate.

[0012] Preferably, the monofunctional acrylic acid includes one or more of cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, cycloaliphatic methacrylate, dicyclopentenyl acrylate, 3,3,5-trimethylcyclohexyl acrylate and (3,3,5-trimethylcyclohexyl) methacrylate.

[0013] Preferably, the bifunctional acrylate includes: one or more of 2-methyl-1,3-propanediol diacrylate, ethylene glycol dimethacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate and propoxylated neopentyl glycol diacrylate.

[0014] Preferably, the multifunctional acrylate includes one or more of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, propoxylated glycerol triacrylate, ethoxylated trimethylolpropane trimethacrylate and ethoxylated pentaerythritol tetraacrylate.

[0015] The present invention provides a method for preparing the impregnating resin described in the above scheme, comprising the following steps:

[0016] Corresponding to the composition of the impregnating resin, monofunctional acrylate, bifunctional acrylate and multifunctional acrylate are added into a reaction kettle, vacuum dehydration is performed under protective atmosphere and heating conditions, and when the water content is ≤800ppm, the vacuum dehydration and heating are stopped, and epoxy acrylate is added into the reaction kettle. When the water content of the material in the reaction kettle is ≤800ppm, the viscosity at 25°C is between 10 and 30mpa·s, the appearance is clear and transparent, and the surface tension at 20°C is between 20 and 30mN / m, the material is discharged to obtain the impregnating resin.

[0017] Preferably, the heating temperature is 80-100°C.

[0018] The present invention provides the use of the impregnating resin described in the above scheme or the impregnating resin prepared by the preparation method described in the above scheme in impregnating graphite materials.

[0019] Preferably, the graphite material includes a graphite bipolar plate.

[0020] The present invention provides the use of the impregnating resin described in the above scheme or the impregnating resin prepared by the preparation method described in the above scheme in an energy storage device.

[0021] The present invention provides an impregnating resin, which comprises the following components in terms of mass percentage: 0-15% of bisphenol A epoxy acrylate, 40-50% of monofunctional acrylate, 20-50% of bifunctional acrylate, and 5-15% of multifunctional acrylate. Epoxy acrylate has good corrosion resistance, adhesion and heat resistance, monofunctional acrylate has low viscosity, excellent permeability and wettability, multifunctional acrylate has high cross-linking density to provide heat resistance and corrosion resistance, and bifunctional acrylate provides excellent comprehensive ability. The present invention gives full play to the characteristics of each component, so that the final impregnating resin has the characteristics of good heat resistance, strong corrosion resistance, good permeability and strong adhesion. The results of the embodiment show that the Tg of the impregnating resin provided by the present invention exceeds 147°C, and the corrosion resistance of acid, alkali, water and freezing liquid is excellent, which can ensure the safety and stability of the battery stack in long-term operation.

[0022] In addition, the viscosity of the impregnating resin provided by the present invention is controlled between 10 and 30 MPa·s, has strong penetration, is easy to be cleaned with a cleaning agent before solidification, does not pollute the surface of the graphite plate, meets the heating and curing conditions of 70° C. to 90° C. in a water bath, is transparent after solidification, has high hardness, good heat resistance, strong corrosion resistance, and the prepared graphite plate has high bending strength. Therefore, the impregnating resin provided by the present invention has great economic value and use value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the DSC thermal performance curve of the resin-impregnated casting of Example 1;

[0024] Figure 2 This is the DSC thermal performance curve of the resin-impregnated casting of Example 2;

[0025] Figure 3 This is the DSC thermal performance curve of the resin-impregnated casting of Example 3;

[0026] Figure 4 This is the DSC thermal performance curve of the resin-impregnated casting of Comparative Example 1;

[0027] Figure 5 This is the DSC thermal performance curve of the resin-impregnated casting of Comparative Example 2. DETAILED DESCRIPTION

[0028] The present invention provides an impregnating resin, which comprises the following components in terms of mass percentage:

[0029]

[0030] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known in the art.

[0031] In the present invention, the monofunctional acrylate refers to an acrylate containing only one functional group, that is, only an ester group; the difunctional acrylate refers to an acrylate containing two ester groups; and the multifunctional acrylate refers to an acrylate containing three or more ester groups.

[0032] In the present invention, the impregnating resin includes 0-15% of epoxy acrylate, preferably 0 or 3-15%, and more preferably 5-10%, by mass percentage. In an embodiment of the present invention, it is specifically 0, 5% or 15%. In the present invention, the epoxy acrylate preferably includes at least one of bisphenol A epoxy acrylate and novolac epoxy acrylate. In the present invention, the epoxy acrylate molecular structure contains a large number of rigid benzene ring structures and multiple highly active double bonds, which can provide excellent corrosion resistance and excellent heat resistance, and a large number of hydroxyl groups are also conducive to excellent adhesion.

[0033] The present invention has no special requirements on the source of the bisphenol A epoxy acrylate, and it can be prepared by a preparation method well known in the art. In an embodiment of the present invention, the preparation method of the bisphenol A epoxy acrylate preferably includes: placing 3700g of bisphenol A 128 epoxy resin in a 60°C oven for 1h to dissolve and reduce viscosity, placing 1500g of methacrylic acid in a 30°C oven for heating for 1h; adding 3700g of bisphenol A 128 epoxy resin, 2.5g of inhibitor MEHQ and 9g of catalyst dimethylbenzyl ammonium chloride into a three-necked flask equipped with a temperature sensor and a mechanical stirrer, heating and stirring to 60°C, adding 500g of methacrylic acid and gradually heating to 115°C; keeping stirring and reacting at the temperature for 30min, when the reaction temperature is reduced to 60°C, adding 1000g of methacrylic acid again and gradually heating to 115°C; measuring the acid value every 0.5h, and when the acid value is reduced to 20-30mg KOH / g, the reaction is completed; adding 5g of MEHQ, when the reaction temperature is reduced to 60°C, discharging the material to obtain bisphenol A epoxy acrylate.

[0034] The present invention has no special requirements for the source of the novolac epoxy acrylate, and it can be prepared by a preparation method well known in the art. In an embodiment of the present invention, the preparation method of the novolac epoxy acrylate preferably includes: placing 575g of novolac epoxy resin 638S and 200g of bisphenol A epoxy resin 128 in an 80°C oven for 1h to dissolve and reduce viscosity, and placing 360g of methacrylic acid in a 30°C oven for heating for 1h; in a three-necked flask equipped with a temperature sensor and a mechanical stirrer, add 575g of novolac epoxy resin 638S, 0.4g of inhibitor MEHQ and 8g of catalyst dimethylbenzyl ammonium chloride, heat and stir to 60°C, then add methacrylic acid and gradually heat to 120°C; keep stirring and reacting at temperature for 30min, measure the acid value every 0.5h, and when the acid value drops to 20-30, the reaction is complete; then add 0.25g MEHQ, and when the reaction temperature drops to 60°C, discharge the material to obtain novolac epoxy acrylate.

[0035] In terms of mass percentage, the impregnating resin includes 40-50% of monofunctional acrylate, preferably 42-48%, and more preferably 44-46%. In an embodiment of the present invention, it is specifically 50%. In the present invention, the monofunctional acrylic acid preferably includes one or more of cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, cycloaliphatic methacrylate, dicyclopentenyl acrylate, 3,3,5-trimethylcyclohexyl acrylate and methacrylate (3,3,5-trimethylcyclohexyl) ester. When the monofunctional acrylic acid is a plurality of the above substances, the present invention has no special requirements for the ratio of each substance, and any ratio is acceptable. In the present invention, the monofunctional acrylate has a lower viscosity and a smaller molecular weight, can provide excellent wettability and penetration, and a moderate double bond can reduce the shrinkage of the matrix, balance heat resistance and toughness, and obtain excellent comprehensive performance.

[0036] In terms of mass percentage, the impregnating resin includes 20-50% of the bifunctional acrylate, preferably 20-45%, and more preferably 25-40%. In an embodiment of the present invention, it is specifically 20%, 35% or 45%. In the present invention, the bifunctional acrylate preferably includes: 2-methyl-1,3-propanediol diacrylate, ethylene glycol dimethacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate and one or more of propoxylated neopentyl glycol diacrylate. When the bifunctional acrylate includes multiple of the above substances, the present invention has no special requirements for the ratio of each substance, and any ratio is acceptable. In the present invention, the bifunctional acrylate has relatively high activity and moderate viscosity. A large number of double bonds can increase the crosslinking density, providing the matrix with better heat resistance. The moderate viscosity and crosslinking density can enable the matrix to simultaneously obtain good heat resistance and permeability properties.

[0037] In terms of mass percentage, the impregnating resin includes 5-15% of multifunctional acrylate, preferably 7-15%, and more preferably 8-12%. In the embodiments of the present invention, it is specifically 5%, 10% or 15%. In the present invention, the multifunctional acrylate preferably includes one or more of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, propoxylated glycerol triacrylate, ethoxylated trimethylolpropane trimethacrylate and ethoxylated pentaerythritol tetraacrylate; when the multifunctional acrylate includes multiple of the above substances, the present invention has no special requirements for the ratio of each substance, and any ratio is acceptable. In the present invention, the multifunctional acrylate can provide more double bonds and higher crosslinking density, which can effectively improve the heat resistance and corrosion resistance of the substrate.

[0038] In the present invention, the viscosity of the impregnating resin at 25° C. is 10 to 30 mPa·s; the surface tension at 20° C. is 20 to 30 mN / m; Tg>147° C.; and the water content is ≤800 ppm.

[0039] The present invention provides a method for preparing the impregnating resin described in the above scheme, comprising the following steps:

[0040] Corresponding to the composition of the impregnating resin, monofunctional acrylate, bifunctional acrylate and multifunctional acrylate are added into a reaction kettle, vacuum dehydration is performed under protective atmosphere and heating conditions, and when the water content is ≤8000ppm, the vacuum dehydration and heating are stopped, and epoxy acrylate is added into the reaction kettle. When the water content of the material in the reaction kettle is ≤800ppm, the viscosity at 25°C is between 10 and 30mpa·s, the appearance is clear and transparent, and the surface tension at 20°C is between 20 and 30mN / m, the material is discharged to obtain the impregnating resin.

[0041] In the present invention, the gas providing the protective atmosphere is preferably nitrogen; the heating temperature is preferably 80°C to 100°C. The present invention has no special requirements for the vacuum dehydration conditions, and the vacuum dehydration conditions well known in the art can be used. In the present invention, the vacuum dehydration is preferably carried out under stirring conditions. The present invention uses vacuum dehydration to reduce the moisture content of the impregnating resin. If the moisture content of the impregnating resin is too high, excessive moisture will vaporize during the resin curing process to produce bubbles and voids, increasing the defects of the material.

[0042] The present invention adds epoxy acrylate when the moisture content is ≤800ppm because epoxy acrylate has a relatively large viscosity and a relatively low dosage. Adding it in the early stage will prolong the mixing time and increase the vacuum dehydration time, thus greatly prolonging the production time. Therefore, adding it after dehydration can improve production efficiency and optimize the process flow.

[0043] After the heating is stopped, the residual temperature in the kettle is used to evenly mix the epoxy acrylate and the resin in the kettle.

[0044] The present invention provides the use of the impregnating resin described in the above scheme or the impregnating resin prepared by the preparation method described in the above scheme in impregnating graphite materials. In the present invention, the graphite material preferably includes a graphite bipolar plate. The present invention has no special requirements for the conditions of the application, and the application conditions well known in the art can be used.

[0045] The present invention also provides the use of the impregnating resin described in the above scheme or the impregnating resin prepared by the preparation method described in the above scheme in an energy storage device. The present invention has no special requirements for the energy storage device, and any energy storage device known in the art can be used, such as a hydrogen energy stack, a lithium battery, etc.; the impregnating resin provided by the present invention can be used as a bonding material, a filling material or an impregnating material in the energy storage device.

[0046] The impregnating resin provided by the present invention and its preparation method and application are described in detail below in conjunction with the embodiments, but they should not be understood as limiting the protection scope of the present invention.

[0047] Example 1

[0048] The impregnating resin provided in this embodiment is composed of the following components in terms of mass percentage:

[0049]

[0050] The preparation method is as follows:

[0051] 1. First, add monofunctional, difunctional and multifunctional acrylate monomers into a stainless steel reactor, pass nitrogen protection, start stirring, and heat to 80°C. Vacuum dehydration is carried out at this temperature for 1 hour, and then the moisture content is tested to ensure that the moisture content is ≤800ppm;

[0052] 2. After the moisture content reaches the standard, turn off the vacuum pump, then put the phenolic epoxy acrylate into the kettle, turn off the heating, and use the residual temperature in the kettle to mix the phenolic epoxy acrylate and the resin in the kettle evenly;

[0053] 3. Stir evenly and cool to room temperature, test the moisture content, viscosity, color appearance, and surface tension. When the moisture content is ≤800ppm, the viscosity at 25℃ is between 10 and 30mpa·s, the appearance is clear and transparent, and the surface tension is between 20 and 30mN / m (20℃), then discharge the material and put it into barrels;

[0054] 4. After the discharge is completed, the stirring is stopped. The properties of the impregnated resin are shown in Table 1. The test standard refers to GB / T 6283-2008.

[0055] Table 1 Performance of the impregnated resin in Example 1

[0056]

[0057]

[0058] An initiator accounting for 0.5 wt% of the impregnated resin was added to the impregnated resin prepared in Example 1, wherein the initiator was an azo diisocyanate mixture (azobisisobutyronitrile and azobisisoheptanenitrile were mixed in a mass ratio of 1:1), stirred evenly, poured into a glass mold, and then placed in a 90°C oven for curing for 1 hour to obtain a resin casting, and then its Tg and hardness were measured. The specific performance test results are shown in Table 2. Figure 1 This is the DSC thermal performance curve of the resin-impregnated casting of Example 1.

[0059] Table 2 Performance of the resin-impregnated casting of Example 1

[0060] Shore Hardness (Shore D) 88 GB / T2411-2008 Tg 154.61℃ GB / T19466.2-2004

[0061] Example 2

[0062] The impregnating resin provided in this embodiment is composed of the following components in terms of mass percentage:

[0063]

[0064] The preparation method is the same as Example 1.

[0065] Table 3 Performance of the impregnated resin in Example 2

[0066] Viscosity (cps / 25℃) 30 Curing time, min (90℃ water bath) 4 Moisture content (%) 500ppm Surface tension, mN / m (20℃) 25

[0067] Sample preparation method: Add 0.8wt% of initiator to the impregnating resin in Example 2, wherein the initiator is an azo diisocyanate mixture (azobisisobutyronitrile and azobisisoheptanenitrile are mixed in a mass ratio of 1:1), stir evenly and pour into a glass mold, then put it into a 90°C oven for curing for 1h to obtain a resin casting, and then measure its Tg and hardness. Figure 2 This is the DSC thermal performance curve of the resin-impregnated casting body of Example 2. The specific test results are shown in Table 4.

[0068] Table 4 Performance of the resin-impregnated casting of Example 2

[0069] Shore Hardness (Shore D) 90 Tg 165.97℃

[0070] Example 3

[0071] The impregnating resin provided in this embodiment is composed of the following components in terms of mass percentage:

[0072]

[0073] The preparation method is the same as Example 1.

[0074] Table 5 Performance of the impregnated resin in Example 3

[0075] Viscosity (cps / 25℃) 12 Curing time, min (90℃ water bath) 4 Moisture content (%) 700ppm Surface tension, mN / m (20℃) 24

[0076] Sample preparation method: Add 1.0% wt of an initiator to the impregnating resin of Example 3, wherein the initiator is an azo diisocyanate mixture (azobisisobutyronitrile and azobisisoheptanenitrile are mixed in a mass ratio of 1:1), stir evenly and pour into a glass mold, then put it into a 90°C oven for curing for 1 hour to obtain a resin casting, and then measure its Tg and hardness. Figure 3 This is the DSC thermal performance curve of the resin-impregnated casting body of Example 3. The specific test results are shown in Table 6.

[0077] Table 6 Performance of the resin-impregnated casting of Example 3

[0078] Shore Hardness (Shore D) 84 Tg 147.54℃

[0079] It can be seen from Tables 1 to 6 that the products prepared in Examples 1 to 3 have a Tg of above 147°C and have good heat resistance; the product prepared in Example 2 has the highest content of epoxy acrylate and multifunctional acrylate, the highest reaction activity, higher hardness, and greater viscosity of the product; in Example 3, the content of epoxy acrylate and multifunctional acrylate is the lowest, and the content of rigid groups such as benzene rings and double bonds in the system is relatively the least, so the relative hardness is low, but the viscosity of the product is the lowest, and the impregnation speed will be faster.

[0080] Comparative Example 1

[0081] The impregnation resin provided in this comparative example is the currently imported American Hernon resin HERNON994M 。

[0082] Table 7 Performance of impregnated resin in Comparative Example 1

[0083] Viscosity (cps / 25℃) 13 Curing time, min (90℃ water bath) 5 Moisture content (%) 750ppm Surface tension, mN / m (20℃) 24.5

[0084] Sample preparation method: Add 1.0% wt of an initiator to the impregnating resin of Comparative Example 1, wherein the initiator is an azo diisocyanate mixture (azobisisobutyronitrile and azobisisoheptanenitrile are mixed in a mass ratio of 1:1), stir evenly and pour into a glass mold, then put it into a 90°C oven for curing for 1 hour to obtain a resin casting, and then measure its Tg and hardness. Figure 4 This is the DSC thermal performance curve of the resin-impregnated casting body of Comparative Example 1. The specific test results are shown in Table 8.

[0085] Table 8 Performance of the resin-impregnated casting body of Comparative Example 1

[0086] Shore Hardness (Shore D) 82 Tg 141.68℃

[0087] Comparative Example 2

[0088] The impregnating resin provided in this comparative example is composed of the following components in terms of mass percentage:

[0089] Isobornyl acrylate 50%,

[0090] Neopentyl glycol propoxylate diacrylate 50%,

[0091] The preparation method is the same as Example 1.

[0092] Table 9 Performance of the impregnated resin in Comparative Example 2

[0093] Viscosity (cps / 25℃) 10 Curing time, min (90℃ water bath) 6 Moisture content (%) 620ppm Surface tension, mN / m (20℃) 22.6

[0094] Sample preparation method: same as Example 1. Figure 5 This is the DSC thermal performance curve of the resin-impregnated casting body of Comparative Example 2. The specific test results are shown in Table 10.

[0095] Table 10 Properties of the resin-impregnated casting body of Comparative Example 2

[0096] Shore Hardness (Shore D) 78 Tg 124.92℃

[0097] Corrosion resistance immersion test:

[0098] Referring to the sample preparation and curing conditions in each embodiment and comparative example, a cured resin casting sample was obtained and cut into strips of 20 cm in length, 10 cm in width and 2 mm in thickness.

[0099] Experimental methods:

[0100] Take 15 5L glass jars, respectively fill them with automobile antifreeze night, 5% concentration of HCl, and deionized water, put the prepared 5 groups of resin casting body solidified specimens (3 specimens in each group) of Examples 1 to 3 and Comparative Examples 1 to 2 into the 15 jars, make sure that all specimens are completely immersed in the solution, then seal the glass jars with plastic wrap and aluminum foil and wrap them with tape for a week to seal. Place the sealed soaking jars in a constant temperature water area of ​​38°C, the entire soaking process is 180 days, take out the specimens every 30 days, clean and dry them, and test their mass changes (take the average value after testing 3 specimens).

[0101] The test results are shown in Tables 11 to 15.

[0102] Table 11 Corrosion resistance immersion data of resin-impregnated castings of Example 1

[0103]

[0104] Table 12 Corrosion resistance immersion data of resin-impregnated castings of Example 2

[0105]

[0106] Table 13 Corrosion resistance immersion data of resin-impregnated castings of Example 3

[0107]

[0108] Table 14 Corrosion resistance immersion data of resin casting body impregnated with comparative example 1

[0109]

[0110] Table 15 Corrosion resistance immersion data of the resin casting body impregnated with comparative example 2

[0111]

[0112] It can be seen from the results of Tables 11 to 15 that the impregnating resins prepared in Examples 1 to 3 have excellent corrosion resistance to acids, alkalis, water and refrigerants, and can ensure the safety and stability of the fuel cell stack during long-term operation.

[0113] The high temperature bending strength test of the graphite plates impregnated with resin was carried out at 100°C;

[0114] Table 16 Bending strength of graphite plates impregnated with different resins at 100°C

[0115]

[0116] It can be seen from the above embodiments and comparative examples that the impregnating resin provided by the present invention has the characteristics of good heat resistance, strong corrosion resistance, high flexural strength, etc. The viscosity of the impregnating resin provided by the present invention is controlled between 10 and 30 MPa·s. The low viscosity makes it easy to clean with a cleaning agent before curing without contaminating the surface of the graphite plate. It meets the heating curing conditions of 70°C to 90°C in a water bath. After curing, it has high hardness, good heat resistance, strong corrosion resistance, and high flexural strength. Therefore, the present invention has great economic value and use value.

[0117] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An impregnation resin, characterized in that Calculated by mass percentage, it is composed of the following components: Epoxy acrylate 0~15%, Monofunctional acrylate 40~50%, Bifunctional acrylate 20~50%, Multifunctional acrylate 5~15%; The multifunctional acrylate refers to an acrylate containing three or more ester groups; The preparation method of the impregnating resin comprises the following steps: Corresponding to the composition of the impregnating resin, monofunctional acrylate, difunctional acrylate and multifunctional acrylate are added to a reaction kettle, vacuum dehydration is performed under protective atmosphere and heating conditions, and when the water content is ≤800ppm, the vacuum dehydration and heating are stopped, and epoxy acrylate is added to the reaction kettle. When the water content of the material in the reaction kettle is ≤800ppm, the viscosity at 25°C is between 10 and 30mpa·s, the appearance is clear and transparent, and the surface tension at 20°C is between 20 and 30mN / m, the material is discharged to obtain the impregnating resin; The monofunctional acrylic acid includes one or more of cyclohexyl methacrylate, isobornyl acrylate, isobornyl methacrylate, cycloaliphatic methacrylate, dicyclopentenyl acrylate, 3,3,5-trimethylcyclohexyl acrylate and (3,3,5-trimethylcyclohexyl) methacrylate.

2. The impregnation resin according to claim 1, characterized in that The epoxy acrylate includes at least one of bisphenol A epoxy acrylate and novolac epoxy acrylate.

3. The impregnation resin according to claim 1, characterized in that The bifunctional acrylate includes one or more of 2-methyl-1,3-propanediol diacrylate, ethylene glycol dimethacrylate, 3-methyl-1,5-pentanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate and propoxylated neopentyl glycol diacrylate.

4. The impregnation resin according to claim 1, characterized in that The multifunctional acrylate includes one or more of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, propoxylated glycerol triacrylate, ethoxylated trimethylolpropane trimethacrylate and ethoxylated pentaerythritol tetraacrylate.

5. The method for preparing the impregnating resin according to any one of claims 1 to 4, characterized in that: The following steps are involved: Corresponding to the composition of the impregnating resin, monofunctional acrylate, difunctional acrylate and multifunctional acrylate are added into a reaction kettle, vacuum dehydration is performed under protective atmosphere and heating conditions, and when the water content is ≤800ppm, the vacuum dehydration and heating are stopped, and epoxy acrylate is added into the reaction kettle. When the water content of the material in the reaction kettle is ≤800ppm, the viscosity at 25°C is between 10 and 30mpa·s, the appearance is clear and transparent, and the surface tension at 20°C is between 20 and 30mN / m, the material is discharged to obtain the impregnating resin.

6. The preparation method according to claim 5, characterized in that: The heating temperature is 80-100°C.

7. Use of the impregnating resin according to any one of claims 1 to 4 or the impregnating resin prepared by the preparation method according to any one of claims 5 to 6 in impregnating graphite materials.

8. The use according to claim 7, characterized in that: The graphite material includes a graphite bipolar plate.

9. Use of the impregnating resin according to any one of claims 1 to 4 or the impregnating resin prepared by the preparation method according to any one of claims 5 to 6 in energy storage devices.

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