A coolant-resistant capacitor sealing plate and capacitor

Abstract

This invention discloses a coolant-resistant capacitor sealing plate and a capacitor. The sealing plate includes a sealing layer and a supporting layer. The sealing layer is selected from an elastic hydrogenated nitrile butadiene rubber material. The hydrogenated nitrile butadiene rubber material is obtained by vulcanizing a hydrogenated nitrile butadiene rubber composition. The hydrogenated nitrile butadiene rubber composition includes hydrogenated nitrile butadiene rubber, which is prepared by copolymerization of unsaturated nitrile monomers, conjugated diene monomers, and aromatic vinyl acid monomers followed by hydrogenation. By introducing aromatic vinyl acid structural units into the hydrogenated nitrile butadiene rubber, this invention achieves good airtightness while meeting the strength requirements of the capacitor sealing plate. It also exhibits excellent compatibility with various coolants, preventing coolant from penetrating into the capacitor element, thereby extending the service life of the sealing plate and the capacitor.

Description

Technical Field

[0001] This invention belongs to the technical field of capacitors, specifically relating to a coolant-resistant capacitor sealing plate and capacitor. Background Technology

[0002] With the development of the domestic and international electronic information industries, such as high-end servers and data centers, the heat dissipation methods for electronic components have gradually shifted from traditional air cooling to spray or immersion liquid cooling. Commonly used coolants include hydrocarbon compounds, silicone oils, and fluorinated liquids. In this application scenario, aluminum electrolytic capacitors need to operate stably in an oil-containing environment. This places new demands on the sealing performance of aluminum electrolytic capacitors. The sealing material (i.e., the capacitor sealing plate) must not only prevent the evaporation of the internal electrolyte but also prevent oil and other impurities from the external environment from entering the capacitor element.

[0003] The capacitor sealing plate includes a sealing layer, which is typically made of a rubber material with a certain degree of elasticity. This layer, when fitted with the capacitor casing, creates a seal to prevent electrolyte leakage. The rubber material is generally selected from EPDM rubber, butyl rubber, silicone rubber, fluororubber, neoprene rubber, or hydrogenated nitrile butadiene rubber. Among these, hydrogenated nitrile butadiene rubber is receiving more attention due to its good heat resistance and excellent chemical corrosion resistance.

[0004] However, existing hydrogenated nitrile rubber materials are still difficult to handle various coolants. When the sealing plate is immersed in coolant, the rubber material that makes up the sealing plate will absorb the coolant and expand, or the coolant will seep into the capacitor element and cause adverse effects. Summary of the Invention

[0005] To address the incompatibility issues between existing hydrogenated nitrile rubber materials and various coolants, this invention provides a coolant-resistant capacitor sealing plate and capacitor.

[0006] The objective of this invention is achieved through the following technical solution.

[0007] In a first aspect, the present invention provides a coolant-resistant capacitor sealing plate, the sealing plate comprising a sealing layer and a support layer, the sealing layer being selected from an elastic hydrogenated nitrile butadiene rubber material, the hydrogenated nitrile butadiene rubber material being obtained by vulcanization of a hydrogenated nitrile butadiene rubber composition, the hydrogenated nitrile butadiene rubber composition comprising hydrogenated nitrile butadiene rubber, and the hydrogenated nitrile butadiene rubber being prepared by hydrogenation following a copolymerization reaction of an unsaturated nitrile monomer, a conjugated diene monomer, and an aromatic vinyl acid monomer represented by Formula I below:

[0008] Formula I;

[0009] In Formula I, R is selected from H, phenyl, or C1-C6 alkyl groups.

[0010] Furthermore, in the polymer monomers of the hydrogenated nitrile rubber, the weight ratio of the unsaturated nitrile monomer, the conjugated diene monomer, and the aromatic vinyl acid monomer is (15~50):(40~85):(3~8).

[0011] Furthermore, the unsaturated nitrile monomer includes acrylonitrile or methacrylonitrile, the conjugated diene monomer is selected from at least one of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene, and the aromatic vinyl acid includes at least one of styrylic acid (CAS: 140-10-3), 3-methylstyrylic acid (CAS: 3029-79-6), and 4-styrylic acid (CAS: 13026-23-8).

[0012] Furthermore, the hydrogenated nitrile rubber composition also includes a vulcanizing agent, a filler, and a processing aid, wherein the weight ratio of the hydrogenated nitrile rubber to the vulcanizing agent, the filler, and the processing aid is 100:(3~7):(40~60):(0.5~2).

[0013] Furthermore, the vulcanizing agent includes at least one of dicumyl peroxide, di-tert-butyl peroxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane; the filler includes at least one of carbon black, clay, talc, calcium carbonate, and silica; and the processing aid includes at least one of fatty acids, fatty acid salts, and fatty acid esters.

[0014] Furthermore, the fatty acid includes at least one of ricinoleic acid, stearic acid, palmitic acid, and lauric acid; the fatty acid salt includes at least one of barium stearate, calcium stearate, and zinc stearate; and the fatty acid ester includes at least one of ricinoleate, stearate, palmitic acid, and lauric acid.

[0015] Furthermore, the coolant-resistant capacitor sealing plate also includes an isolation layer, which is located on the surface of the support layer opposite to the sealing layer, and the isolation layer is selected from PP film and / or PE film.

[0016] Furthermore, the support layer is a phenolic resin laminate.

[0017] Furthermore, the hydrogenated nitrile rubber has an iodine value of 5-20 mg / 100mg and a Mooney viscosity of ML. (1+4) 100℃ corresponds to 30~160.

[0018] Furthermore, the preparation method of the hydrogenated nitrile butadiene rubber material includes the following steps:

[0019] S1. An nitrile rubber containing aromatic ethylene glycol structural units is prepared by copolymerizing unsaturated nitrile monomers, conjugated diene monomers and aromatic ethylene glycol monomers.

[0020] S2. The nitrile rubber prepared in step S1 is hydrogenated to form hydrogenated nitrile rubber;

[0021] S3. The hydrogenated nitrile butadiene rubber prepared in step S2 is mixed with vulcanizing agent, filler and processing aid, and vulcanized at 140~180℃ to obtain hydrogenated nitrile butadiene rubber material.

[0022] In a second aspect, the present invention provides a capacitor, including a coolant-resistant capacitor sealing plate as described in the first aspect.

[0023] Compared with the prior art, the present invention has the following beneficial effects.

[0024] This invention introduces aromatic vinyl acid structural units into hydrogenated nitrile butadiene rubber (NBR). The phenyl groups enhance thermal stability and mechanical strength, while the unsaturated acidic groups increase the polarity of the NBR, improving the oil (coolant) resistance of the capacitor sealing plate. Fillers in the NBR composition can increase the strength of the rubber material (capacitor sealing plate), while processing aids can improve the dispersibility and flowability of the components in the rubber composition, thereby improving molding processability.

[0025] The hydrogenated nitrile rubber material of this invention, while meeting the strength requirements of capacitor sealing plates, has good airtightness and excellent compatibility with various coolants, preventing coolants from penetrating into capacitor elements, thereby extending the service life of the sealing plate and capacitor. Detailed Implementation

[0026] To make the technical problems solved, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the embodiments described herein are only some, not all, of the embodiments of this invention, and are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the protection scope of this invention.

[0027] It should be noted that, in this invention, as is known to those skilled in the art of chemical synthesis, after the corresponding monomers of each structural unit participate in the polymerization reaction, the structural portion of that monomer present in the resulting polymer (hydrogenated nitrile rubber). The mass ratio of each structural unit is the mass ratio of the monomers providing each structural unit.

[0028] In a first aspect, the present invention provides a coolant-resistant capacitor sealing plate, the sealing plate comprising a sealing layer and a support layer, the sealing layer being selected from an elastic hydrogenated nitrile butadiene rubber material, the hydrogenated nitrile butadiene rubber material being obtained by vulcanization of a hydrogenated nitrile butadiene rubber composition, the hydrogenated nitrile butadiene rubber composition comprising hydrogenated nitrile butadiene rubber, and the hydrogenated nitrile butadiene rubber being prepared by copolymerization of unsaturated nitrile monomers, conjugated diene monomers and aromatic vinyl acid monomers followed by hydrogenation.

[0029] In some specific embodiments, the weight ratio of the unsaturated nitrile monomer, the conjugated diene monomer and the aromatic vinyl acid monomer in the polymer monomer of the hydrogenated nitrile rubber is (15~50):(40~85):(3~8).

[0030] In some specific embodiments, the unsaturated nitrile monomer includes acrylonitrile or methacrylonitrile, preferably acrylonitrile; the higher the content of unsaturated nitrile monomer, the better the oil resistance, but the rebound performance decreases and the cold resistance deteriorates.

[0031] In some specific embodiments, the conjugated diene monomer is selected from at least one of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene, preferably 1,3-butadiene.

[0032] In some specific embodiments, the aromatic vinyl acid includes at least one of styrenic acid (CAS: 140-10-3), 3-methylstyrenic acid (CAS: 3029-79-6), and 4-styrenic acid (CAS: 13026-23-8), preferably 4-styrenic acid.

[0033] In some specific embodiments, the hydrogenated nitrile rubber composition further includes a vulcanizing agent, filler, and processing aid, wherein the weight ratio of the hydrogenated nitrile rubber to the vulcanizing agent, filler, and processing aid is 100:(3~7):(40~60):(0.5~2).

[0034] In some specific embodiments, the vulcanizing agent includes at least one selected from dicumyl peroxide, di-tert-butyl peroxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane. The filler includes at least one selected from carbon black, clay, talc, calcium carbonate, and silica, wherein the silica can be surface-treated with a silane coupling agent; carbon black is preferred as it can improve the strength of the rubber material (capacitor sealing plate). The processing aid includes at least one selected from fatty acids, fatty acid salts, and fatty acid esters.

[0035] In some specific embodiments, the fatty acid includes at least one selected from ricinoleic acid, stearic acid, palmitic acid, and lauric acid; the fatty acid salt includes at least one selected from barium stearate, calcium stearate, and zinc stearate; and the fatty acid ester includes at least one selected from ricinoleic acid ester, stearic acid ester, palmitic acid ester, and lauric acid ester. Stearic acid is preferred, as it can improve the dispersibility and flowability of the components in the hydrogenated nitrile rubber composition, thereby improving molding processability.

[0036] In some embodiments, the coolant-resistant capacitor sealing plate further includes an insulating layer located on the surface of the support layer opposite to the sealing layer. The insulating layer is selected from PP film and / or PE film. The insulating layer serves to prevent direct contact between the electrolyte and the support layer.

[0037] In some specific embodiments, the support layer is a phenolic resin laminate.

[0038] In some specific embodiments, the preparation method of the hydrogenated nitrile butadiene rubber material includes the following steps:

[0039] S1. An nitrile rubber containing aromatic ethylene glycol structural units is prepared by copolymerizing unsaturated nitrile monomers, conjugated diene monomers, and aromatic ethylene glycol monomers. Any one of the known emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization methods can be used, with emulsion polymerization being preferred. In the copolymerization reaction, an emulsifier (sodium dodecylbenzenesulfonate), a molecular weight regulator (e.g., tert-dodecyl mercaptan), a polymerization initiator (e.g., cumene hydroperoxide), and a polymerization terminator (e.g., hydroquinone) can be added.

[0040] S2. The nitrile rubber prepared in step S1 is hydrogenated to form hydrogenated nitrile rubber. There is no particular limitation on the hydrogenation method; known methods can be used, such as oil layer hydrogenation (where the latex of the copolymer (nitrile rubber) obtained through emulsion polymerization is coagulated and then hydrogenated in an oil layer), or aqueous layer hydrogenation (where the latex of the obtained copolymer is directly hydrogenated). The iodine value of the hydrogenated nitrile rubber is preferably 5~20 mg / 100mg, and its Mooney viscosity (ML) is... (1+4) 100℃ is preferably 30~160℃;

[0041] S3. Mix the hydrogenated nitrile butadiene rubber prepared in step S2 with vulcanizing agent, filler and processing aid, and vulcanize at 140~180℃ for 20~40 min to obtain hydrogenated nitrile butadiene rubber material.

[0042] The sealing plate for the capacitor described in this invention is prepared by stacking a support layer and a hydrogenated nitrile rubber material, followed by hot pressing.

[0043] In a second aspect, the present invention provides a capacitor, including a coolant-resistant capacitor sealing plate as described in the first aspect.

[0044] The specific embodiments of the present invention will be further explained and described below through examples and comparative examples.

[0045] Unless otherwise specified, all reagents, materials, and instruments used in the following description are conventional reagents, materials, and instruments, all of which are commercially available. The reagents involved can also be synthesized using conventional synthetic methods. Unless otherwise specified, the methods in the examples are conventional methods in the art. Monomers conforming to this invention are commercially available.

[0046] Example 1

[0047] 1) Preparation of hydrogenated nitrile butadiene rubber

[0048] In a reactor, 180 parts by weight of deionized water, 25 parts by weight of a 10 wt% sodium dodecylbenzenesulfonate aqueous solution, 25 parts by weight of acrylonitrile, and 0.5 parts by weight of tert-dodecyl mercaptan were added sequentially. After purging the internal gas with nitrogen three times, 60 parts by weight of 1,3-butadiene and 6 parts by weight of 4-styrenic acid were added. The reactor was kept at 5°C, and 0.1 parts by weight of cumene hydroperoxide were added. Emulsion polymerization was carried out for 16 hours while the reactor was rotated. The polymerization reaction was terminated by adding 0.1 parts by weight of a 10 wt% hydroquinone aqueous solution. Residual monomers were removed using a rotary evaporator at 60°C to obtain the latex of the copolymer nitrile rubber (solid content approximately 30 wt%).

[0049] Then, using an aqueous hydrogenation method, the latex of the copolymer nitrile butadiene rubber and a palladium catalyst were added to a high-pressure reactor. The palladium catalyst was a solution composed of a 1 wt% palladium acetate-acetone solution and an equal weight of ion-exchanged water. The amount of palladium catalyst used was preferably 1100 ppm, based on 100 parts by weight of the un-hydrogenated copolymer nitrile butadiene rubber (the target material for hydrogenation) and expressed as a palladium equivalent. The hydrogenation reaction was carried out at a hydrogen pressure of 3.2 MPa and a temperature of 60°C for 8 hours to obtain hydrogenated nitrile butadiene rubber.

[0050] 2) Preparation of hydrogenated nitrile butadiene rubber materials

[0051] 100 parts by weight of hydrogenated nitrile butadiene rubber, 5 parts by weight of dicumyl peroxide, 50 parts by weight of carbon black and 1 part by weight of stearic acid were mixed and vulcanized at 160°C for 30 minutes to obtain hydrogenated nitrile butadiene rubber material.

[0052] Example 2

[0053] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the amounts of the three monomers used to prepare hydrogenated nitrile butadiene rubber are different: 50 parts by weight of acrylonitrile, 85 parts by weight of 1,3-butadiene, and 8 parts by weight of 4-styrenic acid.

[0054] Example 3

[0055] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the amounts of the three monomers used to prepare hydrogenated nitrile butadiene rubber are different: 15 parts by weight of acrylonitrile, 40 parts by weight of 1,3-butadiene, and 3 parts by weight of 4-styrenic acid.

[0056] Example 4

[0057] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the three monomers used to prepare hydrogenated nitrile butadiene rubber and their amounts are different: 20 parts by weight of methacrylonitrile, 50 parts by weight of isoprene, and 5 parts by weight of styrene.

[0058] Example 5

[0059] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the three monomers used to prepare hydrogenated nitrile butadiene rubber are different: 25 parts by weight of methacrylonitrile, 60 parts by weight of 1,3-pentadiene, and 6 parts by weight of methylstyrenic acid.

[0060] Example 6

[0061] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the three monomers used to prepare hydrogenated nitrile butadiene rubber are different: 25 parts by weight of methacrylonitrile, 60 parts by weight of 2,3-dimethyl-1,3-butadiene, and 6 parts by weight of 4-styrenic acid.

[0062] Example 7

[0063] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the three monomers used to prepare hydrogenated nitrile butadiene rubber are different: 25 parts by weight of methacrylonitrile, 60 parts by weight of 1,3-butadiene, and 6 parts by weight of 4-styrenic acid.

[0064] Example 8

[0065] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber material. The difference is that the amount of hydrogenated nitrile butadiene rubber, vulcanizing agent, filler and processing aid used to prepare the hydrogenated nitrile butadiene rubber material is different: 100 parts by weight of hydrogenated nitrile butadiene rubber, 3 parts by weight of dicumyl peroxide, 40 parts by weight of carbon black and 0.5 parts by weight of stearic acid.

[0066] Example 9

[0067] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber material. The difference is that the amount of hydrogenated nitrile butadiene rubber, vulcanizing agent, filler and processing aid used to prepare hydrogenated nitrile butadiene rubber material is different: 100 parts by weight of hydrogenated nitrile butadiene rubber, 7 parts by weight of dicumyl peroxide, 60 parts by weight of carbon black and 2 parts by weight of stearic acid.

[0068] Example 10

[0069] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber material. The difference is that the hydrogenated nitrile butadiene rubber used to prepare the hydrogenated nitrile butadiene rubber material is different from the vulcanizing agent, filler and processing aid: 100 parts by weight of hydrogenated nitrile butadiene rubber, 5 parts by weight of di-tert-butyl peroxide diisopropylbenzene, 50 parts by weight of calcium carbonate and 1 part by weight of stearate.

[0070] Example 11

[0071] This embodiment uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the hydrogenated nitrile butadiene rubber, vulcanizing agent, filler, and processing aids used to prepare the hydrogenated nitrile butadiene rubber material are different in their amounts: 100 parts by weight of hydrogenated nitrile butadiene rubber, 4 parts by weight of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 45 parts by weight of silica, and 0.8 parts by weight of barium stearate.

[0072] Comparative Example 1

[0073] This comparative example uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the monomers used to prepare the hydrogenated nitrile butadiene rubber do not contain aromatic vinyl acid monomers.

[0074] Comparative Example 2

[0075] This comparative example uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the amount of aromatic vinyl acid monomer used to prepare hydrogenated nitrile butadiene rubber is excessive, which is 10 parts by weight of 4-styrenic acid.

[0076] Comparative Example 3

[0077] This comparative example uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the monomer used to prepare the hydrogenated nitrile butadiene rubber does not contain aromatic vinyl acid monomers, but instead contains acrylic acid.

[0078] Comparative Example 4

[0079] This comparative example uses most of the operating steps in Example 1 to prepare hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials. The difference is that the monomer used to prepare the hydrogenated nitrile butadiene rubber does not contain aromatic vinyl acid monomers, but instead contains styrene.

[0080] Performance testing:

[0081] To better understand the present invention, the hydrogenated nitrile butadiene rubber and hydrogenated nitrile butadiene rubber materials prepared in the above embodiments and comparative examples were tested as follows. The test results of the iodine value, Mooney viscosity of the hydrogenated nitrile butadiene rubber and the tensile strength of the hydrogenated nitrile butadiene rubber material are shown in Table 1.

[0082] [Iodine value] The iodine value of hydrogenated nitrile rubber is determined according to JIS K6235.

[0083] [Mooney viscosity] The Mooney viscosity of hydrogenated nitrile rubber was determined according to JIS K6300.

[0084] [Tensile Strength Test] The tensile strength of hydrogenated nitrile rubber materials shall be tested according to the test method specified in GB / T 528-2009.

[0085] Table 1 Test Results

[0086]

[0087] [Immersion Test] Hydrogenated nitrile rubber material was cut into sheets with an area of ​​2*2 square centimeters and a thickness of 5 mm. The hardness and volume before immersion were tested. The sheets were immersed in test tubes containing different coolants: hydrocarbons (polyalphaolefins), silicone oils (polymethylphenylsiloxanes), and fluorinated liquids (1,1,2,3,3,3-hexafluoropropyl methyl ether). The test tubes were placed in an oven at a set temperature of 85°C for 200 hours. The test tubes were then removed from the oven and allowed to cool at room temperature for 1 hour. After cooling, the sheets were removed, and the test coolant adhering to the sheets was wiped off. The hardness and volume after immersion were then tested. The Shore A hardness (Shore hardness) was tested using a GSD-719K rubber hardness tester according to the test method specified in GB / T 531.1-2008. The test results are shown in Table 2. The rate of change in hardness and volume before and after immersion were calculated.

[0088] Hardness change rate (%) = (Hardness after immersion - Hardness before immersion) / Hardness before immersion * 100%;

[0089] Volume change rate (%) = (Volume after immersion - Volume before immersion) / Volume before immersion * 100%.

[0090] Table 2 Test results of immersion test

[0091]

[0092] As shown in the test results in Tables 1 and 2, this invention introduces aromatic vinyl acid structural units into hydrogenated nitrile butadiene rubber. The phenyl groups enhance thermal stability and mechanical strength, while the acidic groups increase the polarity of the hydrogenated nitrile butadiene rubber, thus improving the oil (coolant) resistance of the capacitor sealing plate. While meeting the strength requirements of the capacitor sealing plate, the hydrogenated nitrile butadiene rubber material not only exhibits good airtightness but also demonstrates excellent compatibility with various coolants. After immersion in different coolants, the absolute value of the hardness change rate is less than 5%, and the volume change rate is less than 3%.

[0093] The test results from Examples 1-11 and Comparative Examples 1 and 2 show that: if the monomer used to prepare hydrogenated nitrile butadiene rubber does not contain aromatic vinyl acid monomers, the tensile strength of the hydrogenated nitrile butadiene rubber material is low, and its hardness and volume changes after immersion in different coolants are large, resulting in poor oil resistance. If too much aromatic vinyl acid monomer is used, the improvement in tensile strength and oil resistance of the hydrogenated nitrile butadiene rubber material is not significant, and the hardness and volume changes after immersion in different coolants are still relatively large, indicating poor compatibility with different coolants. However, the hardness and volume changes are smaller compared to Comparative Example 1. This also shows that the addition of aromatic vinyl acid monomers can improve compatibility with different coolants. When the amount of aromatic vinyl acid monomer added is within a suitable range, the tensile strength and compatibility with coolants of the hydrogenated nitrile butadiene rubber material can be effectively improved, meeting the strength requirements of the capacitor sealing plate.

[0094] As can be seen from Examples 1-11 and Comparative Examples 3 and 4, if the monomer used to prepare hydrogenated nitrile butadiene rubber is replaced with a monomer containing only acidic groups, the tensile strength of the hydrogenated nitrile butadiene rubber material is not enhanced. Moreover, its hardness and volume change are large after immersion in different coolants, and its compatibility with different coolants is poor. If it is replaced with a monomer containing only benzene rings, the tensile strength of the hydrogenated nitrile butadiene rubber material is improved, but its oil resistance is not significantly improved.

[0095] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the nature and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention.

Claims

1. A coolant resistant capacitor sealing plate, said sealing plate comprising a sealing layer and a support layer, said sealing layer being selected from a hydrogenated nitrile butadiene rubber material having an elasticity, characterized in that, The hydrogenated nitrile rubber material is obtained by vulcanizing a hydrogenated nitrile rubber composition, the hydrogenated nitrile rubber composition comprises hydrogenated nitrile rubber, and the hydrogenated nitrile rubber is prepared by copolymerization of unsaturated nitrile monomers, conjugated diene monomers and aromatic vinyl acid monomers represented by the following formula I and hydrogenation: Formula I; In formula I, R is selected from phenyl or C1-C6 alkyl; the weight ratio of the unsaturated nitrile monomers, the conjugated diene monomers and the aromatic vinyl acid monomers in the polymerized monomers of the hydrogenated nitrile rubber is (15-50):(40-85):(3-8).

2. The coolant fluid resistant capacitor sealing plate of claim 1, wherein, The unsaturated nitrile monomers comprise acrylonitrile or methacrylonitrile, the conjugated diene monomers are selected from at least one of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and 1,3-pentadiene, and the aromatic vinyl acid monomers comprise at least one of 3-methylstyrene acid and 4-styrene acid.

3. The coolant fluid resistant capacitor sealing plate of claim 1, wherein, The hydrogenated nitrile rubber composition further comprises a vulcanizing agent, a filler and a processing aid, and the weight ratio of the hydrogenated nitrile rubber, the vulcanizing agent, the filler and the processing aid is 100:(3-7):(40-60):(0.5-2).

4. The coolant fluid resistant capacitor sealing plate of claim 3, wherein, The vulcanizing agent comprises at least one of dicumyl peroxide, di-tert-butyl peroxide and 2,5-dimethyl-2,5-di(tert-butyl peroxy)hexane, the filler comprises at least one of carbon black, clay, talc, calcium carbonate and silicon dioxide, and the processing aid comprises at least one of fatty acid, fatty acid salt and fatty acid ester.

5. The coolant fluid resistant capacitor sealing plate of claim 4, wherein, The fatty acid comprises at least one of ricinoleic acid, stearic acid, palmitic acid and lauric acid, the fatty acid salt comprises at least one of barium stearate, calcium stearate and zinc stearate, and the fatty acid ester comprises at least one of ricinoleate, stearate, palmitate and laurate.

6. The coolant fluid resistant capacitor sealing plate of claim 1, wherein, The coolant-resistant capacitor sealing plate further comprises a separation layer on the surface of the support layer away from the sealing layer, and the separation layer is selected from a PP film and / or a PE film.

7. The coolant fluid resistant capacitor sealing plate of claim 1, wherein, The hydrogenated nitrile rubber has an iodine value of 5 to 20 mg / 100 mg, a Mooney viscosity ML (1+4) 100°C is 30 to 160.

8. The coolant fluid resistant capacitor sealing plate of claim 3, wherein, The preparation method of the hydrogenated nitrile rubber material comprises the following steps: S1, copolymerizing unsaturated nitrile monomers, conjugated diene monomers and aromatic vinyl acid monomers to prepare a nitrile rubber containing aromatic vinyl acid structural units; S2, hydrogenating the nitrile rubber prepared in step S1 to form a hydrogenated nitrile rubber; S3, mixing the hydrogenated nitrile rubber prepared in step S2 with a vulcanizing agent, a filler and a processing aid, and vulcanizing at 140-180°C to obtain a hydrogenated nitrile rubber material.

9. A capacitor characterized by The coolant-resistant capacitor sealing plate comprises the coolant-resistant capacitor sealing plate according to any one of claims 1 to 8.

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