Ceramic material for relay and preparation method thereof

Abstract

The invention relates to the field of ceramic materials, in particular to a ceramic material for a relay and a preparation method of the ceramic material. The super-hydrophobic coating is prepared from the following raw materials in percentage by weight: 4 to 6 percent of macromolecular resin, 0.5 to 1 percent of diphenylmethane bismaleimide, 0.1 to 0.5 percent of silane coupling agent, 1 to 2 percent of organic silicon polymer, 6 to 8 percent of inorganic nano filler, 2 to 4 percent of curing agent and the balance of diluent. The method has important technical significance and application value for improving the safety and reliability of the relay.

Description

Technical Field

[0001] This invention relates to the field of ceramic materials, specifically to a ceramic material for relays and its preparation method. Background Technology

[0002] With the rapid development of new energy vehicles, smart grids, industrial automation, and aerospace, the safety and reliability requirements for power electronic devices are increasing. Ceramic vacuum relays, as high-performance power electronic switching devices based on ceramic substrates and vacuum packaging technology, have become core components in new energy vehicle battery management systems, ultra-high voltage power transmission systems, and industrial automation control due to their excellent insulation performance, high-temperature resistance, and "arc-free switching" advantages. Their working principle utilizes the vacuum environment to suppress arc generation, achieving stable circuit switching control, and they are widely used in high-voltage DC circuit switching scenarios.

[0003] However, during the manufacturing, transfer, and assembly of ceramic vacuum relays, the ceramic housing surface is highly susceptible to adsorbing various contaminants, including but not limited to conductive salts, oil stains, and dust particles from the environment. These contaminants come from diverse sources, and their adsorption on the ceramic housing surface can severely damage the relay's insulation performance, potentially causing surface arcing or leakage current, leading to a decrease in surface insulation resistance, a significant reduction in high-voltage withstand capability, and potential safety hazards.

[0004] Therefore, developing a relay with superhydrophobic properties can effectively prevent the adsorption of contaminants and maintain the stability of surface insulation performance, which is of great technical significance and application value for improving the safety and reliability of relays. Summary of the Invention

[0005] Purpose of the invention: To address the above-mentioned technical problems, this invention proposes a ceramic material for relays and its preparation method.

[0006] The technical solution adopted is as follows: A ceramic material for relays, comprising a ceramic matrix and a superhydrophobic coating; The superhydrophobic coating is made from the following raw materials in weight percentages: The composition consists of 4-6% polymer resin, 0.5-1% diphenylmethane bismaleimide, 0.1-0.5% silane coupling agent, 1-2% organosilicon polymer, 6-8% inorganic nanofiller, 2-4% curing agent, and the remainder is diluent.

[0007] Furthermore, the polymer resin is an epoxy resin.

[0008] Epoxy resin undergoes a ring-opening addition reaction with curing agents DDS (4,4'-diaminodiphenyl sulfone) and HTDA (methylcyclohexanediamine) to form a crosslinked network containing sulfone groups and alicyclic structures. The sulfone groups provide high modulus, while the flexible segments of the alicyclic structure can relieve internal stress, forming a more uniform crosslinked network and reducing stress concentration points. The two work synergistically to improve the crosslinking density and mechanical properties of the coating.

[0009] The diphenylmethane bismaleimide molecule has a rigid bicyclic structure, which can significantly improve the thermal stability and mechanical strength of the superhydrophobic coating.

[0010] Furthermore, the silane coupling agent is KH-560.

[0011] The silane coupling agent KH-560 contains epoxy and silane groups in its structure. Its function is to improve the interfacial bonding between inorganic nanofillers and epoxy resin matrix, and it can also act as a compatibilizer to improve the interfacial compatibility between epoxy resin and organosilicon polymer. It establishes a strong chemical bond at the interface between epoxy resin and organosilicon polymer, significantly improves the compatibility between the two, and prevents phase separation.

[0012] Furthermore, the organosilicon polymer is obtained by reacting hydrogen-containing silicone oil with alkenylamine to obtain an intermediate, which is then reacted with glycidyl furfuryl ether to obtain the final product.

[0013] Furthermore, the structural formula of the alkenylamine is shown below: ;

[0014] Where n≥6.

[0015] The reaction of hydrogen-containing silicone oil with alkenylamine introduces amino groups, providing active sites for subsequent reactions. The carbon chain length (n≥6) ensures a flexible chain structure, avoiding excessive rigidity that could lead to coating embrittlement. The intermediate then reacts with glycidyl furfuryl ether to introduce furan groups. During the curing process of the superhydrophobic coating, these groups undergo a Diels-Alder (DA) reaction with diphenylmethane bismaleimide to form high-energy covalent bonds, significantly improving the interfacial bonding strength between the resin matrix and the organosilicon and enhancing its high-temperature resistance. This allows the coating to maintain its superhydrophobic properties even after 5 hours at an ambient temperature of 120±5℃.

[0016] Furthermore, the inorganic nanofiller is a trimetallic layered hydroxide.

[0017] Furthermore, the trimetallic layered hydroxide is a combination of TiMgAl-layered hydroxide nanospheres and TiMgAl-layered hydroxide nanosheets.

[0018] Ti 4+ It possesses stronger Lewis acidity, and its introduction may promote ring-opening reactions with epoxy groups, thereby enhancing the interfacial bonding strength between the inorganic nanofiller and the resin matrix. Furthermore, Ti...4+ The introduction of Ti enables the formation of Ti-O bonds on the surface of the layered hydroxide. Ti-O bonds have lower surface energy than Mg-O and Al-O bonds, thus improving the superhydrophobic properties of the coating. Furthermore, Ti... 4+ The light absorption of the introduced layered hydroxide can be extended to the visible light region, which theoretically can endow the coating with the ability to photocatalytically degrade organic pollutants and achieve self-cleaning.

[0019] Furthermore, the mass ratio of the TiMgAl-layered hydroxide nanospheres to the TiMgAl-layered hydroxide nanosheets is 1-4:1-4.

[0020] Nanosheets and nanoplatelets provide micron- and nanometer-level roughness, respectively, forming a "micro-nano secondary structure." This rough surface of the "micro-nano secondary structure" can trap an air layer, forming an "air cushion," reducing the solid-liquid contact area and providing the necessary structural basis for superhydrophobicity. The two work together to ensure that the droplet only makes point contact with the surface, achieving superhydrophobicity. Moreover, due to the small solid-liquid contact area, the adhesion of contaminants to the surface is weak, making them easily captured by the droplet, thus achieving self-cleaning.

[0021] Furthermore, the preparation method of the TiMgAl-layered hydroxide nanospheres is as follows: Dissolve water-soluble titanium salt, water-soluble magnesium salt, water-soluble aluminum salt, polyethylene glycol, and glutamic acid in deionized water, add a precipitant, and then seal the mixture for hydrothermal reaction at 120-140℃. After the reaction is complete, collect the product, wash it, and dry it.

[0022] Furthermore, the preparation method of the TiMgAl-layered hydroxide nanosheets is as follows: Dissolve water-soluble titanium salt, water-soluble magnesium salt, and water-soluble aluminum salt in deionized water, add a precipitant, and then seal the mixture for hydrothermal reaction at 120-140℃. After the reaction is complete, collect the product, wash it, and then dry it.

[0023] Furthermore, the precipitant is preferably urea.

[0024] Furthermore, the curing agent is a combination of curing agent DDS and curing agent HTDA, and the mass ratio of curing agent DDS to curing agent HTDA is 1-4:1-4.

[0025] This invention also provides a method for preparing ceramic materials for relays: A coating is obtained by uniformly mixing a polymer resin, diphenylmethane bismaleimide, silane coupling agent, organosilicon polymer, inorganic nanofiller, curing agent and diluent, and then applying the coating to the surface of the ceramic substrate.

[0026] The beneficial effects of this invention are: This invention provides a ceramic material for relays, comprising a ceramic matrix and a superhydrophobic coating. In the superhydrophobic coating, a polymer resin serves as the mechanical skeleton, an organosilicon polymer provides the superhydrophobic network, and diphenylmethane bismaleimide not only enhances the strength of the superhydrophobic coating but also provides thermal protection for the superhydrophobic network. A trimetallic layered hydroxide, by constructing a "micro-nano secondary structure," reduces the solid-liquid contact area and achieves self-cleaning. The multiple components of this invention synergistically enhance the antifouling and surface insulation properties of the ceramic material, which has significant technical importance and application value for improving the safety and reliability of relays. Detailed Implementation

[0027] Unless otherwise specified in the examples, the conditions were performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

[0028] Example 1: A ceramic material for relays, comprising an alumina ceramic matrix and a superhydrophobic coating; The superhydrophobic coating is made from the following raw materials in weight percentages: The composition is as follows: epoxy resin E-51 5%, diphenylmethane bismaleimide 0.8%, silane coupling agent KH-560 0.3%, organosilicon polymer 1.5%, TiMgAl-layered hydroxide nanospheres 6%, TiMgAl-layered hydroxide nanosheets 2%, curing agent DDS 1.5%, curing agent HTDA 1.5%, and the balance is acetone.

[0029] The organosilicon polymer is obtained by reacting hydrogen-containing silicone oil with 1-amino-10-undecene to obtain an intermediate, which is then reacted with glycidyl furfuryl ether. The specific method is as follows: Under nitrogen protection, 10g of hydrogen-containing silicone oil (Zhongbao Silicon Material, hydrogen mass fraction 0.8%), 50μg of Karstedt catalyst, and 150ml of toluene were added to a flask. After stirring evenly, the temperature was adjusted to 55℃. Then, 13.54g of 1-amino-10-undecene and 50ml of toluene were mixed evenly and slowly added dropwise to the flask. The mixture was kept warm and stirred continuously for 8 hours. After the reaction was completed, 10g of activated carbon was added, and the mixture was kept warm and stirred for 30 minutes for adsorption. The mixture was then filtered, and the filtrate was passed through a silica gel column. The eluent was collected and distilled under reduced pressure to obtain intermediate 1. Under nitrogen protection, 10g of intermediate 1, 1g of glycidyl furfuryl ether, and 150ml of toluene were added to a flask. After stirring evenly, the temperature was adjusted to 90℃ and the mixture was reacted for 8 hours. After the reaction was completed, the small molecules were removed by distillation under reduced pressure.

[0030] The preparation method of TiMgAl-layered hydroxide nanospheres is as follows: 5 mmol Ti(SO4)2, 100 mmol MgCl2• 6H2O, 50 mmol AlCl3• 9H2O, 1 g polyethylene glycol-2000 and 11 g glutamic acid were dissolved in 500 ml deionized water, and then 36 g urea was added. The mixture was then transferred to a hydrothermal reactor, sealed, and the temperature was adjusted to 130 °C. The mixture was then stirred and hydrothermally reacted for 10 h. After the reaction was completed, the product was collected by filtration, thoroughly washed with deionized water, dried, and ground. The microstructure of the product, observed by scanning electron microscopy, showed that it consisted of nanospheres with a diameter of approximately 200 nm.

[0031] The preparation method of TiMgAl-layered hydroxide nanosheets is as follows: 5 mmol Ti(SO4)2, 100 mmol MgCl2•6H2O and 50 mmol AlCl3•6H2O were dissolved in 500 ml of deionized water, and then 36 g of urea was added. The mixture was then transferred to a hydrothermal reactor, sealed, and the temperature was adjusted to 130 °C. The mixture was then stirred and hydrothermally reacted for 10 h. After the reaction was completed, the product was collected by filtration, thoroughly washed with deionized water, dried, and ground. The microstructure of the product, observed by scanning electron microscopy, showed regular hexagonal nanosheets with a size of about 2 μm and a thickness of about 50 nm.

[0032] The preparation method of the above-mentioned ceramic material for relays: Epoxy resin E-51, diphenylmethane bismaleimide, silane coupling agent KH-560, organosilicon polymer, TiMgAl-layered hydroxide nanospheres, TiMgAl-layered hydroxide nanosheets, curing agent DDS, curing agent HTDA, and acetone were mixed and stirred evenly. Then, the mixture was dispersed in a homogenizer for 15 minutes (speed 20000 r / min) to obtain a coating. The alumina ceramic substrate was cleaned, sanded with 240# sandpaper, and dried. The coating was then sprayed onto the surface of the alumina ceramic substrate using a spray gun. The spraying process parameters were: spraying distance 200 mm, spraying pressure 0.74 MPa, spraying angle 90°, and spraying thickness approximately 200 ± 10 μm. Finally, the coating was cured at room temperature for 48 hours.

[0033] Example 2: A ceramic material for relays, comprising an alumina ceramic matrix and a superhydrophobic coating; The superhydrophobic coating is made from the following raw materials in weight percentages: The composition is as follows: epoxy resin E-51 6%, diphenylmethane bismaleimide 1%, silane coupling agent KH-560 0.5%, organosilicon polymer 2%, TiMgAl-layered hydroxide nanospheres 4%, TiMgAl-layered hydroxide nanosheets 4%, curing agent DDS 2%, curing agent HTDA 2%, and the balance is acetone.

[0034] The preparation methods of the organosilicon polymer, TiMgAl-layered hydroxide nanospheres, and TiMgAl-layered hydroxide nanosheets are the same as in Example 1.

[0035] The preparation method of the above-mentioned ceramic material for relays: Epoxy resin E-51, diphenylmethane bismaleimide, silane coupling agent KH-560, organosilicon polymer, TiMgAl-layered hydroxide nanospheres, TiMgAl-layered hydroxide nanosheets, curing agent DDS, curing agent HTDA, and acetone were mixed and stirred evenly. Then, the mixture was dispersed in a homogenizer for 15 minutes (speed 20000 r / min) to obtain a coating. The alumina ceramic substrate was cleaned, sanded with 240# sandpaper, and dried. The coating was then sprayed onto the surface of the alumina ceramic substrate using a spray gun. The spraying process parameters were: spraying distance 200 mm, spraying pressure 0.74 MPa, spraying angle 90°, and spraying thickness approximately 200 ± 10 μm. Finally, the coating was cured at room temperature for 48 hours.

[0036] Example 3: A ceramic material for relays, comprising an alumina ceramic matrix and a superhydrophobic coating; The superhydrophobic coating is made from the following raw materials in weight percentages: The composition is as follows: epoxy resin E-51 4%, diphenylmethane bismaleimide 0.5%, silane coupling agent KH-560 0.1%, organosilicon polymer 1%, TiMgAl-layered hydroxide nanospheres 3%, TiMgAl-layered hydroxide nanosheets 3%, curing agent DDS 1%, curing agent HTDA 1%, and the balance is acetone.

[0037] The preparation methods of the organosilicon polymer, TiMgAl-layered hydroxide nanospheres, and TiMgAl-layered hydroxide nanosheets are the same as in Example 1.

[0038] The preparation method of the above-mentioned ceramic material for relays: Epoxy resin E-51, diphenylmethane bismaleimide, silane coupling agent KH-560, organosilicon polymer, TiMgAl-layered hydroxide nanospheres, TiMgAl-layered hydroxide nanosheets, curing agent DDS, curing agent HTDA, and acetone were mixed and stirred evenly. Then, the mixture was dispersed in a homogenizer for 15 minutes (speed 20000 r / min) to obtain a coating. The alumina ceramic substrate was cleaned, sanded with 240# sandpaper, and dried. The coating was then sprayed onto the surface of the alumina ceramic substrate using a spray gun. The spraying process parameters were: spraying distance 200 mm, spraying pressure 0.74 MPa, spraying angle 90°, and spraying thickness approximately 200 ± 10 μm. Finally, the coating was cured at room temperature for 48 hours.

[0039] Example 4: A ceramic material for relays, comprising an alumina ceramic matrix and a superhydrophobic coating; The superhydrophobic coating is made from the following raw materials in weight percentages: The composition is as follows: epoxy resin E-51 6%, diphenylmethane bismaleimide 0.5%, silane coupling agent KH-560 0.5%, organosilicon polymer 1%, TiMgAl-layered hydroxide nanospheres 4%, TiMgAl-layered hydroxide nanosheets 3%, curing agent DDS 2%, curing agent HTDA 1%, and the balance is acetone.

[0040] The preparation methods of the organosilicon polymer, TiMgAl-layered hydroxide nanospheres, and TiMgAl-layered hydroxide nanosheets are the same as in Example 1.

[0041] The preparation method of the above-mentioned ceramic material for relays: Epoxy resin E-51, diphenylmethane bismaleimide, silane coupling agent KH-560, organosilicon polymer, TiMgAl-layered hydroxide nanospheres, TiMgAl-layered hydroxide nanosheets, curing agent DDS, curing agent HTDA, and acetone were mixed and stirred evenly. Then, the mixture was dispersed in a homogenizer for 15 minutes (speed 20000 r / min) to obtain a coating. The alumina ceramic substrate was cleaned, sanded with 240# sandpaper, and dried. The coating was then sprayed onto the surface of the alumina ceramic substrate using a spray gun. The spraying process parameters were: spraying distance 200 mm, spraying pressure 0.74 MPa, spraying angle 90°, and spraying thickness approximately 200 ± 10 μm. Finally, the coating was cured at room temperature for 48 hours.

[0042] Example 5: A ceramic material for relays, comprising an alumina ceramic matrix and a superhydrophobic coating; The superhydrophobic coating is made from the following raw materials in weight percentages: The composition is as follows: epoxy resin E-51 4%, diphenylmethane bismaleimide 1%, silane coupling agent KH-560 0.1%, organosilicon polymer 2%, TiMgAl-layered hydroxide nanospheres 3%, TiMgAl-layered hydroxide nanosheets 4%, curing agent DDS 1%, curing agent HTDA 2%, and the balance is acetone.

[0043] The preparation methods of the organosilicon polymer, TiMgAl-layered hydroxide nanospheres, and TiMgAl-layered hydroxide nanosheets are the same as in Example 1.

[0044] The preparation method of the above-mentioned ceramic material for relays: Epoxy resin E-51, diphenylmethane bismaleimide, silane coupling agent KH-560, organosilicon polymer, TiMgAl-layered hydroxide nanospheres, TiMgAl-layered hydroxide nanosheets, curing agent DDS, curing agent HTDA, and acetone were mixed and stirred evenly. Then, the mixture was dispersed in a homogenizer for 15 minutes (speed 20000 r / min) to obtain a coating. The alumina ceramic substrate was cleaned, sanded with 240# sandpaper, and dried. The coating was then sprayed onto the surface of the alumina ceramic substrate using a spray gun. The spraying process parameters were: spraying distance 200 mm, spraying pressure 0.74 MPa, spraying angle 90°, and spraying thickness approximately 200 ± 10 μm. Finally, the coating was cured at room temperature for 48 hours.

[0045] Comparative Example 1: It is basically the same as Example 1, except that no organosilicon polymer is added.

[0046] Comparative Example 2: It is basically the same as Comparative Example 1, except that hydrogen-containing silicone oil (Zhongbao Silicon Material, with a hydrogen mass fraction of 0.8%) is used instead of organosilicon polymer.

[0047] Comparative Example 3: It is basically the same as Comparative Example 1, except that diphenylmethane bismaleimide is not added.

[0048] Comparative Example 4: The example is basically the same as Example 1, except that only TiMgAl-layered hydroxide nanospheres with a mass percentage of 8% are added as inorganic nanofillers.

[0049] Comparative Example 5: The example is basically the same as Example 1, except that only 8% by mass TiMgAl-layered hydroxide nanosheets are added as inorganic nanofillers.

[0050] Comparative Example 6: It is basically the same as Comparative Example 5, except that MgAl-layered hydroxide nanosheets (Xianfeng Nano) are used instead of TiMgAl-layered hydroxide nanosheets as inorganic nanofillers.

[0051] Performance testing The ceramic materials prepared in Examples 1-5 and Comparative Examples 1-6 were used as samples for performance testing.

[0052] According to GB / T 6739-2006, the hardness of superhydrophobic coatings is tested using the pencil hardness test method. The hardness of the superhydrophobic coating is the pencil hardness at which the coating no longer breaks after being scratched by a pencil.

[0053] The static contact angle of a droplet on a superhydrophobic coating surface was measured using an SDC-100 optical contact angle meter via the seated drop method. The roll-off angle of a droplet just beginning to roll off the superhydrophobic coating surface was measured using a GFSG60-35 manual angle stage.

[0054] The samples were placed in an oven at 120±5℃ for 5 hours, and then the static contact angle and roll-off angle were measured. The test results are shown in Table 1 below: The test results are shown in Table 1 below: Table 1:

[0055] As shown in Table 1 above, the superhydrophobic coating on the surface of the ceramic material of the present invention not only has high hardness, but also has good superhydrophobic properties. After being kept in an oven at 120±5℃ for 5 hours, the contact angle still remains above 160°, demonstrating excellent high-temperature resistance.

[0056] A comparison of the data from Example 1 and Comparative Example 1 shows that the addition of organosilicon polymer can effectively improve the superhydrophobic properties and high-temperature resistance of the coating.

[0057] A comparison of the data from Example 1 and Comparative Example 2 shows that the addition of hydrogen-containing silicone oil after modification with 1-amino-10-undecene and glycidyl furfural ether can effectively improve the superhydrophobic properties and high-temperature resistance of the coating.

[0058] A comparison of the data from Example 1 and Comparative Example 3 shows that the addition of diphenylmethane bismaleimide significantly improves the mechanical properties, superhydrophobic properties, and high-temperature resistance of the coating.

[0059] A comparison of the data from Example 1 and Comparative Examples 4-5 shows that the combination of TiMgAl-layered hydroxide nanospheres and TiMgAl-layered hydroxide nanosheets as inorganic nanofillers can effectively improve the superhydrophobic properties of the coating.

[0060] A comparison of the data from Comparative Example 5 and Comparative Example 6 shows that, compared to MgAl-layered hydroxide nanosheets, using TiMgAl-layered hydroxide nanosheets as inorganic nanofillers results in coatings with better superhydrophobic properties.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ceramic material for relays, characterized in that, It consists of a ceramic substrate and a superhydrophobic coating; The superhydrophobic coating is made from the following raw materials in weight percentages: The composition consists of 4-6% polymer resin, 0.5-1% diphenylmethane bismaleimide, 0.1-0.5% silane coupling agent, 1-2% organosilicon polymer, 6-8% inorganic nanofiller, 2-4% curing agent, and the remainder is diluent.

2. The ceramic material for relays as described in claim 1, characterized in that, The polymer resin is epoxy resin.

3. The ceramic material for relays as described in claim 1, characterized in that, The silane coupling agent is KH-560.

4. The ceramic material for relays as described in claim 1, characterized in that, Organosilicon polymers are obtained by reacting hydrogen-containing silicone oil with alkenylamine to obtain an intermediate, which is then reacted with glycidyl furfuryl ether to obtain the final product.

5. The ceramic material for relays as described in claim 4, characterized in that, The structural formula of the alkenylamine is shown below: Where n≥6.

6. The ceramic material for relays as described in claim 1, characterized in that, The inorganic nanofiller is a trimetallic layered hydroxide.

7. The ceramic material for relays as described in claim 6, characterized in that, The trimetallic layered hydroxide is a combination of TiMgAl-layered hydroxide nanospheres and TiMgAl-layered hydroxide nanosheets.

8. The ceramic material for relays as described in claim 7, characterized in that, The mass ratio of the TiMgAl-layered hydroxide nanospheres to the TiMgAl-layered hydroxide nanosheets is 1-4:1-4.

9. The ceramic material for relays as described in claim 7, characterized in that, The preparation method of the TiMgAl-layered hydroxide nanospheres is as follows: Dissolve water-soluble titanium salt, water-soluble magnesium salt, water-soluble aluminum salt, polyethylene glycol, and glutamic acid in deionized water, add a precipitant, and then seal the mixture for hydrothermal reaction at 120-140℃. After the reaction is complete, collect the product, wash it, and dry it.

10. A method for preparing a ceramic material for a relay as described in any one of claims 1-9, characterized in that, A coating is obtained by uniformly mixing a polymer resin, diphenylmethane bismaleimide, silane coupling agent, organosilicon polymer, inorganic nanofiller, curing agent and diluent, and then applying the coating to the surface of the ceramic substrate.

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