Sealing element for new energy battery electric box and preparation method of sealing element

Abstract

The invention relates to the technical field of sealing elements, in particular to a sealing element for a new energy battery electric box. Comprising the following components in parts by weight: 75-85 parts of matrix rubber, 5-10 parts of modified carbon nanotubes, 4-8 parts of boron nitride nanosheets, 3-5 parts of fumed silica, 2-3 parts of zinc oxide, 1.5-2 parts of an anti-aging agent, 4-6 parts of a plasticizer, 1-2 parts of a vulcanizing agent, 1-2 parts of an accelerant, 15-25 parts of carbon black, 4-6 parts of modified superfine concentrate powder and 3-5 parts of stearic acid. The performance limitation of a single material is overcome through blending of the fluororubber, the silicone rubber and the nitrile rubber; through the synergistic effect of the modified carbon nanotubes and the boron nitride nanosheets, the thermal conductivity of the sealing element can be improved, and the mechanical strength and the insulativity can be enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of seals, in particular to a seal for a new energy battery electric box and a preparation method thereof. Background Art

[0002] As a core component in fields such as electric vehicles and energy storage systems, the new energy battery electric box is a key structural component for accommodating and protecting the battery pack. Its core function is to provide a stable operating environment for the battery and ensure its safety, reliability, and long life under complex working conditions. As an important part of the battery electric box, the seal plays a two-way protection role of isolating the external environment (such as moisture, dust, corrosive gases) and preventing the leakage of internal electrolyte, directly affecting the overall performance and safety of the battery system. However, the existing seals for battery electric boxes still have significant deficiencies in practical applications: First, traditional rubber-based sealing materials are prone to aging, hardening, or swelling under long-term high and low temperature cycles (-40°C to 80°C) and chemical corrosion environments, resulting in a risk of seal failure; Second, the adaptability of the seal structure design to the deformation of the electric box (such as thermal expansion during charging and discharging, vibration and shock) is insufficient, and local seal gaps are easily caused by stress concentration; Third, the dynamic sealing performance is insufficient, and it is difficult to effectively cope with the transient pressure changes caused by air pressure fluctuations or gas evolution during battery operation. These problems have become important bottlenecks restricting the improvement of battery system safety and the optimization of the full life cycle cost. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a seal for a new energy battery electric box and a preparation method thereof to solve the above problems.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: A seal for a new energy battery electric box, comprising the following components in parts by weight: Matrix rubber 75 - 85 parts Modified carbon nanotubes 5 - 10 parts Boron nitride nanosheets 4 - 8 parts Fumed silica 3 - 5 parts Zinc oxide 2 - 3 parts Antioxidant 1.5 - 2 parts Plasticizer 4 - 6 parts Vulcanizing agent 1 - 2 parts Accelerator 1 - 2 parts Carbon black 15 - 25 parts Modified ultrafine concentrate powder 4 - 6 parts Stearic acid 3 - 5 parts.

[0005] As a further solution of the present invention, the matrix rubber is a mixed rubber of fluororubber, silicone rubber, and nitrile rubber, and the mass ratio of fluororubber, silicone rubber, and nitrile rubber is 1:(1.2 - 1.5):(1.5 - 2).

[0006] As a further solution of the present invention, the modified carbon nanotubes are grafted modification products of hydroxylated carbon nanotubes and silane coupling agents, the grafting rate is 10 - 15%, and the diameter of the carbon nanotubes is 12 - 18 nm and the aspect ratio ≥ 100.

[0007] As a further solution of the present invention, the anti-aging agent is anti-aging agent RD or anti-aging agent D or anti-aging agent 264.

[0008] As a further solution of the present invention, the plasticizer is environmentally friendly epoxy soybean oil.

[0009] As a further solution of the present invention, the vulcanizing agent is dicumyl peroxide, bis-tert-butylperoxide diisopropylbenzene, and 2,4-dichlorobenzoyl peroxide, and the mass ratio of dicumyl peroxide, bis-tert-butylperoxide diisopropylbenzene, and 2,4-dichlorobenzoyl peroxide is 1:2:1.

[0010] As a further solution of the present invention, the accelerator is accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS; the mass ratio of accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS is (1 - 2):(1 - 3):(1 - 2):1.

[0011] A preparation method of a seal for a new energy battery electric box, the specific steps are as follows: Step 1, weigh fluororubber, silicone rubber, and nitrile rubber according to the mass ratio, and mix and put them into a mixer at 60 - 80 °C for 15 - 30 min to form matrix rubber; Step 2, weigh modified carbon nanotubes, boron nitride nanosheets, modified ultrafine concentrate powder, and fumed silica according to the mass parts and add them to the matrix rubber successively, heat up to 85 - 100 °C, and mix for 20 - 30 min until the fillers are evenly dispersed; Step 3, weigh zinc oxide, anti-aging agent, and plasticizer according to the mass parts and put them into the mixture in Step 2, and mix at 70 - 80 °C for 20 - 30 min; Step 4, weigh vulcanizing agent, accelerator, carbon black, and stearic acid according to the mass parts and add them, and mix at low speed at 45 - 60 °C for 5 - 10 min to avoid early vulcanization; Step 5, process the mixed rubber into a seal blank through a dynamic molding process; Step 6, place the blank in a vulcanizing device to vulcanize into a seal.

[0012] As a further solution of the present invention, in step five, the molding pressure is 10 - 20 MPa, the temperature is 150 - 170 °C, and the time is 5 - 10 min.

[0013] As a further solution of the present invention, in step six, pre-vulcanization is first carried out at 100 - 120 °C for 1 - 2 h, and then secondary vulcanization is carried out at 200 - 220 °C for 4 - 6 h.

[0014] Since the present invention adopts the above technical solutions, the advantages and positive effects of the present invention are as follows: By blending fluororubber, silicone rubber, and nitrile rubber, the performance limitations of single materials are overcome; Through the synergistic effect of modified carbon nanotubes and boron nitride nanosheets, the thermal conductivity, mechanical strength, and insulation of the seal can be improved; By means of a segmented process of stepwise increasing pressure, low-temperature pre-vulcanization - high-temperature secondary vulcanization, the internal stress of the material is eliminated, so that the compression set rate of the seal under long-term high and low temperature cycles is ≤ 20%; An environmentally friendly epoxy soybean oil is used to solve the problem of poor compatibility between traditional plasticizers and silicone rubber, and prevent migration and precipitation. Specific embodiments

[0015] Example 1 A seal for a new energy battery electrical box according to the present invention comprises the following components in parts by weight: Matrix rubber 75 parts Modified carbon nanotubes 5 parts Boron nitride nanosheets 4 parts Fumed silica 3 parts Zinc oxide 2 parts Antioxidant 1.5 parts Plasticizer 4 parts Vulcanizing agent 1 part Accelerator 1 part Carbon black 15 parts Modified ultrafine concentrate powder 4 parts Stearic acid 3 parts; Among them, the matrix rubber is a mixed rubber of fluororubber, silicone rubber, and nitrile rubber, and the mass ratio of fluororubber, silicone rubber, and nitrile rubber is 1:1.2:1.5; the modified carbon nanotubes are grafted modified products of hydroxylated carbon nanotubes and silane coupling agent, the grafting rate is 10%, and the diameter of the carbon nanotubes is 12 nm and the aspect ratio ≥ 100; the antioxidant is antioxidant RD; the plasticizer is environmentally friendly epoxy soybean oil; the vulcanizing agent is dicumyl peroxide, bis(tert-butylperoxy)diisopropylbenzene, and 2,4-dichlorobenzoyl peroxide, and the mass ratio of dicumyl peroxide, bis(tert-butylperoxy)diisopropylbenzene, and 2,4-dichlorobenzoyl peroxide is 1:2:1; the accelerator is accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS; the mass ratio of accelerator TMTD, accelerator MBTS, accelerator MBT, and accelerator CBS is 1:1:1:1.

[0016] A preparation method of a seal for a new energy battery electric box, the specific steps are as follows: Step 1, weigh fluororubber, silicone rubber, and nitrile rubber according to the mass ratio, and mix and put them into a mixer at 60 °C for 15 min to form matrix rubber; Step 2, weigh modified carbon nanotubes, boron nitride nanosheets, modified ultrafine concentrate powder, and fumed silica according to the mass parts and add them to the matrix rubber successively, heat up to 85 °C, and mix for 20 min until the fillers are evenly dispersed; Step 3, weigh zinc oxide, anti-aging agent, and plasticizer according to the mass parts and put them into the mixture in Step 2, and mix at 70 °C for 20 min; Step 4, weigh vulcanizing agent, accelerator, carbon black, and stearic acid according to the mass parts and put them in, and mix at low speed at 45 °C for 5 min to avoid early vulcanization; Step 5, process the mixed rubber into a seal blank through a dynamic molding process; Step 6, place the blank in a vulcanizing device to vulcanize into a seal; Among them, the molding pressure in Step 5 is 10 MPa, the temperature is 150 °C, and the time is 5 min; in Step 6, pre-vulcanize at 100 °C for 1 h first, and then perform secondary vulcanization at 200 °C for 4 h.

[0017] Example 2 A seal for a new energy battery electric box according to the present invention, characterized in that it comprises the following components in parts by weight: Matrix rubber 78 parts Modified carbon nanotubes 7 parts Boron nitride nanosheets 5 parts Fumed silica 3 parts Zinc oxide 2 parts Antioxidant 1.5 parts Plasticizer 5 parts 1 part of vulcanizing agent 1 part of accelerator 18 parts of carbon black 4 parts of modified superfine concentrate powder 3 parts of stearic acid; The matrix rubber is a mixed rubber of fluororubber, silicone rubber and nitrile rubber, and the mass ratio of fluororubber, silicone rubber and nitrile rubber is 1:1.3:1.7; the modified carbon nanotubes are grafted modified products of hydroxylated carbon nanotubes and silane coupling agent, the grafting rate is 12%, and the carbon nanotube diameter is 14 nm and the aspect ratio ≥ 100; the antioxidant is antioxidant D; the plasticizer is environmentally friendly epoxy soybean oil; the vulcanizing agent is dicumyl peroxide, bis-tert-butyl peroxide diisopropylbenzene and 2,4-dichlorobenzoyl peroxide, and the mass ratio of dicumyl peroxide, bis-tert-butyl peroxide diisopropylbenzene and 2,4-dichlorobenzoyl peroxide is 1:2:1; the accelerator is accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS; the mass ratio of accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS is 1.3:1.8:1.5:1.

[0018] A preparation method of a seal for a new energy battery electric box, the specific steps are as follows: Step 1, weigh fluororubber, silicone rubber and nitrile rubber according to the mass ratio, and mix and put them into a mixer at 65 °C for 20 min to form matrix rubber; Step 2, weigh modified carbon nanotubes, boron nitride nanosheets, modified superfine concentrate powder and fumed silica according to the mass parts and add them to the matrix rubber successively, heat up to 90 °C, and mix for 24 min until the fillers are uniformly dispersed; Step 3, weigh zinc oxide, anti-aging agent and plasticizer according to the mass parts and put them into the mixture in Step 2, and mix at 74 °C for 24 min; Step 4, weigh vulcanizing agent, accelerator, carbon black and stearic acid according to the mass parts and put them in, and mix at low speed at 50 °C for 6 min to avoid early vulcanization; Step 5, process the mixed rubber into a seal blank through a dynamic molding process; Step 6, place the blank in a vulcanizing device to vulcanize into a seal; Among them, the molding pressure in Step 5 is 14 MPa, the temperature is 158 °C, and the time is 7 min; in Step 6, pre-vulcanize at 110 °C for 1.5 h first, and then perform secondary vulcanization at 210 °C for 5 h.

[0019] Example 3 A seal for a new energy battery electric box of the present invention comprises the following components in parts by weight: 82 parts of matrix rubber 8 parts of modified carbon nanotubes 7 parts of boron nitride nanosheets 4 parts of fumed silica 3 parts of zinc oxide 2 parts of antioxidant 5 parts of plasticizer 2 parts of vulcanizing agent 2 parts of accelerator 23 parts of carbon black 5 parts of modified ultra-fine concentrate powder 4 parts of stearic acid; The matrix rubber is a mixed rubber of fluororubber, silicone rubber and nitrile rubber, and the mass ratio of fluororubber, silicone rubber and nitrile rubber is 1:1.4:1.8; the modified carbon nanotubes are grafted modified products of hydroxylated carbon nanotubes and silane coupling agent, the grafting rate is 14%, and the diameter of the carbon nanotubes is 16 nm and the aspect ratio ≥ 100; the antioxidant is antioxidant 264; the plasticizer is environmentally friendly epoxy soybean oil; the vulcanizing agent is dicumyl peroxide, bis(tert-butylperoxy)diisopropylbenzene and 2,4-dichlorobenzoyl peroxide, and the mass ratio of dicumyl peroxide, bis(tert-butylperoxy)diisopropylbenzene and 2,4-dichlorobenzoyl peroxide is 1:2:1; the accelerator is accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS; the mass ratio of accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS is 1.8:2.7:1.8:1.

[0020] A preparation method of a seal for a new energy battery electric box, the specific steps are as follows: Step 1, weigh fluororubber, silicone rubber and nitrile rubber according to the mass ratio, mix and put them into a mixer at 75 °C and blend for 25 min to form matrix rubber; Step 2, weigh the modified carbon nanotubes, boron nitride nanosheets, modified ultra-fine concentrate powder and fumed silica according to the mass parts and add them to the matrix rubber successively, raise the temperature to 95 °C, and knead for 27 min until the fillers are uniformly dispersed; Step 3, weigh zinc oxide, anti-aging agent and plasticizer according to the mass parts and put them into the mixture in Step 2, and knead at 78 °C for 28 min; Step 4, weigh the vulcanizing agent, accelerator, carbon black and stearic acid according to the mass parts and put them in, and knead at low speed at 55 °C for 8 min to avoid early vulcanization; Step 5, process the kneaded rubber into a seal blank through a dynamic molding process; Step 6, place the blank in a vulcanizing device and vulcanize it into a seal; Among them, the molding pressure in Step 5 is 18 MPa, the temperature is 165 °C, and the time is 8 min; in Step 6, pre-vulcanization is carried out at 115 °C for 2 h first, and then secondary vulcanization is carried out at 215 °C for 5 h.

[0021] Example 4 A seal for a new energy battery electrical box of the present invention comprises the following components by weight: Matrix rubber: 85 parts Modified carbon nanotubes: 10 parts Boron nitride nanosheets: 8 parts Fumed silica: 5 parts Zinc oxide: 3 parts Antioxidant: 2 parts Plasticizer: 6 parts Vulcanizing agent: 2 parts Accelerator: 2 parts Carbon black: 25 parts Modified ultrafine concentrate powder: 6 parts Stearic acid: 5 parts; Among them, the matrix rubber is a mixed rubber of fluororubber, silicone rubber and nitrile rubber, and the mass ratio of fluororubber, silicone rubber and nitrile rubber is 1:1.5:2. The modified carbon nanotubes are grafted modified products of hydroxylated carbon nanotubes and silane coupling agent, the grafting rate is 15%, and the diameter of the carbon nanotubes is 18 nm and the aspect ratio ≥ 100; the antioxidant is antioxidant 264; the plasticizer is environmentally friendly epoxy soybean oil; the vulcanizing agent is dicumyl peroxide, bis(tert-butylperoxy)diisopropylbenzene and 2,4-dichlorobenzoyl peroxide, and the mass ratio of dicumyl peroxide, bis(tert-butylperoxy)diisopropylbenzene and 2,4-dichlorobenzoyl peroxide is 1:2:1; the accelerator is accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS; the mass ratio of accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS is 2:3:2:1.

[0022] A preparation method of a seal for a new energy battery electrical box comprises the following specific steps: Step 1: Weigh fluororubber, silicone rubber and nitrile rubber according to the mass ratio, mix and put them into a mixer at 80 °C for 30 min to form matrix rubber; Step 2: Weigh modified carbon nanotubes, boron nitride nanosheets, modified ultrafine concentrate powder and fumed silica according to the parts by weight and add them to the matrix rubber successively, heat up to 100 °C, and mix for 30 min until the fillers are evenly dispersed; Step 3: Weigh zinc oxide, antioxidant and plasticizer according to the parts by weight and put them into the mixture in Step 2, and mix at 80 °C for 30 min; Step 4: Weigh vulcanizing agent, accelerator, carbon black and stearic acid according to the parts by weight and put them in, and mix at low speed at 60 °C for 10 min to avoid early vulcanization; Step 5: Process the mixed rubber into a seal blank through a dynamic molding process; Step 6: Place the blank in a vulcanizing device to vulcanize into a seal. Among them, in step five, the molding pressure is 20 MPa, the temperature is 170 °C, and the time is 10 min; in step six, pre-vulcanization is first carried out at 120 °C for 2 h, and then secondary vulcanization is carried out at 220 °C for 6 h.

[0023] Table 1 shows the performance tests of Examples 1-4 As can be seen from Table 1, the present invention overcomes the performance limitations of single materials through the blending of fluororubber, silicone rubber, and nitrile rubber; through the synergistic effect of modified carbon nanotubes and boron nitride nanosheets, the thermal conductivity of the seal can be improved, the mechanical strength and insulation can be enhanced; through the stepped increase in pressure and the segmented process of low-temperature pre-vulcanization - high-temperature secondary vulcanization, the internal stress of the material is eliminated, so that the compression set rate of the seal under long-term high and low temperature cycles is ≤20%; the use of environmentally friendly epoxy soybean oil solves the problem of poor compatibility between traditional plasticizers and silicone rubber and avoids migration and precipitation.

[0024] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes or modifications can be made to these embodiments without departing from the principle and essence of the present invention. The protection scope of the present invention is only limited by the appended claims.

Claims

1. A seal for a new energy battery electrical box, characterized in that: It includes the following components by weight: 75 - 85 parts of matrix rubber 5 - 10 parts of modified carbon nanotubes 4 - 8 parts of boron nitride nanosheets 3 - 5 parts of fumed silica 2 - 3 parts of zinc oxide 1.5 - 2 parts of antioxidant 4 - 6 parts of plasticizer 1 - 2 parts of vulcanizing agent 1 - 2 parts of accelerator 15 - 25 parts of carbon black 4 - 6 parts of modified ultrafine concentrate powder 3 - 5 parts of stearic acid.

2. The seal for a new energy battery electrical box according to claim 1, wherein: The matrix rubber is a mixed rubber of fluororubber, silicone rubber and nitrile rubber, and the mass ratio of fluororubber, silicone rubber and nitrile rubber is 1:(1.2 - 1.5):(1.5 - 2).

3. The seal for a new energy battery electrical box according to claim 1, wherein: The modified carbon nanotubes are grafted modified products of hydroxylated carbon nanotubes and silane coupling agent, the grafting rate is 10 - 15%, and the diameter of the carbon nanotubes is 12 - 18nm and the aspect ratio ≥100.

4. The seal for a new energy battery electrical box according to claim 1, characterized in that: The antioxidant is antioxidant RD or antioxidant D or antioxidant 264.

5. A seal for a new energy battery electrical box according to claim 1, characterized in that: The plasticizer is environmentally friendly epoxy soybean oil.

6. The seal for a new energy battery electrical box according to claim 1, characterized in that: The vulcanizing agent is dicumyl peroxide, bis - tert - butylperoxide - diisopropylbenzene and 2,4 - dichlorobenzoyl peroxide, and the mass ratio of dicumyl peroxide, bis - tert - butylperoxide - diisopropylbenzene and 2,4 - dichlorobenzoyl peroxide is 1:2:

1.

7. A seal for a new energy battery electrical box according to claim 1, characterized in that: The accelerator is accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS; the mass ratio of accelerator TMTD, accelerator MBTS, accelerator MBT, accelerator CBS is (1 - 2):(1 - 3):(1 - 2):

1.

8. The preparation method of a seal for a new energy battery electrical box according to any one of claims 1-7, characterized in that: Specific steps are as follows: Step 1, weigh fluororubber, silicone rubber and nitrile rubber according to the mass ratio, mix and put them into a mixer at 60 - 80°C for 15 - 30 min to form matrix rubber; Step 2, weigh modified carbon nanotubes, boron nitride nanosheets, modified ultrafine concentrate powder and fumed silica according to the parts by weight and add them to the matrix rubber successively, heat up to 85 - 100°C, and mix for 20 - 30 min until the fillers are evenly dispersed; Step 3, weigh zinc oxide, antioxidant and plasticizer according to the parts by weight and put them into the mixture in Step 2, and mix at 70 - 80°C for 20 - 30 min; Step 4, weigh vulcanizing agent, accelerator, carbon black and stearic acid according to the parts by weight and put them in, and mix at a low speed at 45 - 60°C for 5 - 10 min to avoid early vulcanization; Step 5, process the mixed rubber into a seal blank through a dynamic molding process; Step 6, place the blank in a vulcanizing device to vulcanize into a seal.

9. The preparation method of a seal for a new energy battery electric box according to claim 8, characterized in that: In Step 5, the molding pressure is 10 - 20 MPa, the temperature is 150 - 170°C, and the time is 5 - 10 min.

10. The preparation method of a seal for a new energy battery electrical box according to claim 8, characterized in that: In Step 6, first pre - vulcanize at 100 - 120°C for 1 - 2 h, and then perform secondary vulcanization at 200 - 220°C for 4 - 6 h.

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