A sealing composite material and a method for producing the same

Abstract

The application relates to the technical field of semiconductor sealing, in particular to a sealing composite material and a preparation method thereof. The sealing composite material provided by the application comprises perfluoroether rubber raw rubber and a vulcanizing agent, the vulcanizing agent has a structure shown in formula (I), and the perfluoroether rubber raw rubber has a cyano reaction site. The sealing composite material formed by using a material with a benzene ring structure as the vulcanizing agent has a more dense three-dimensional network structure, further hinders the thermal motion of molecular chains, and further, the pi-pi stacking effect between benzene rings can also enhance the stability of the molecular chains; however, the more the number of benzene rings is, the stronger the rigidity of the formed sealing composite material is, and the hardness of the material is increased; the material with anthracene as the main structure is used as the vulcanizing agent, the heat resistance of the material is improved under the premise of maintaining the hardness of the sealing composite material.

Description

Technical Field

[0001] This invention relates to the technical field of semiconductor sealing, and more specifically to a sealing composite material and its preparation method. Background Technology

[0002] Sealing composite materials are used in equipment sealing applications, and sealing performance is an important factor affecting processing technology and equipment performance.

[0003] With the rapid development of the semiconductor industry, the requirements for processing equipment are becoming increasingly stringent, which has driven the improvement of various properties of sealing materials to meet production needs. High-temperature environments are required in many wafer processing steps in semiconductor technology, such as deposition, photoresist removal, and epitaxial growth. This necessitates that sealing materials possess reliable and excellent high-temperature resistance.

[0004] Perfluoroelastomer (PFE) rubber is commonly used as a sealing material in related technologies, as it can maintain stable performance over long periods from -39°C to 288°C. However, its high-temperature resistance is still not ideal in some harsh high-temperature environments. To address this, related technologies improve its high-temperature performance by modifying the structure of fluoropolymers, for example, by adding additives such as magnesium oxide, calcium hydroxide, and lead oxide to improve the high-temperature resistance, mechanical properties, and processing performance of PFE rubber. However, the use of these additives introduces metallic elements such as magnesium, calcium, or lead, which negatively impacts subsequent wafer etching processes, thereby reducing process yield, and is not particularly effective in improving high-temperature resistance. Summary of the Invention

[0005] Therefore, the present invention provides a sealing composite material and its preparation method, which can improve high temperature resistance in a low cost and effectively, and reduce the adverse effects on the overall process.

[0006] Therefore, on the one hand, the present invention provides a sealing composite material comprising perfluoroether rubber raw rubber and a vulcanizing agent, wherein the vulcanizing agent has the structure shown in formula (I).

[0007]

[0008] The perfluoroether rubber raw rubber has cyano reaction sites.

[0009] In some embodiments, the crosslinking units of the sealing composite material have the structure shown in formula (II).

[0010]

[0011] In some embodiments, the perfluoroether rubber raw rubber comprises tetrafluoroethylene, perfluoroalkyl vinyl ether, and a third monomer, wherein the third monomer comprises perfluoro-4-cyanovinyl ether.

[0012] In some embodiments, the mass ratio of the perfluoroether rubber raw rubber to the vulcanizing agent is 100:1-3, preferably 100:1-2.

[0013] In some embodiments, the accelerator and filler are further included, wherein the accelerator is carbonamide and the filler is carbon black; wherein the mass ratio of the perfluoroether rubber raw rubber, the accelerator and the filler is 100:0.3-2:15-30, preferably 100:0.3-1:15-20.

[0014] In some embodiments, the carbon black is N990 carbon black with a particle size of 280nm-320nm, and the accelerator is carbamide, i.e. urea. Urea needs to be ground before use, and the particle size of urea is 0.85mm-2.80mm.

[0015] On the other hand, the present invention provides a method for preparing a sealing composite material, comprising the following steps: mixing the raw materials in a certain proportion to obtain a composition; placing the composition into a mold and obtaining the sealing composite material through a vulcanization process.

[0016] It should be noted that perfluoroelastomers (PFEs), widely used in semiconductors, aerospace, and petrochemicals, possess excellent mechanical properties and chemical resistance. However, PFEs are difficult to process and generally rely on closed-loop plasticizers for mixing. Closed-loop plasticizers offer high shearing efficiency, precise temperature control, and their sealed chambers prevent contamination, making them more suitable for the preparation of high-purity PFEs. Through mixing, debinding, and post-processing in a closed-loop plasticizer, high-performance PFEs can be obtained. Currently, closed-loop plasticizers are equipped with automated control programs to reduce human intervention and strictly control the conditions and parameters at each operating stage to match the target performance of the PFEs. Furthermore, the material, after being mixed in a closed plasticizer, is extruded into strips or blocks using a debinding machine for preliminary shaping. The debinding machine can be either a plunger-type or a screw-type debinding machine. The material after being processed by the debinding machine is transferred to the open mill and mixed again with vulcanizing agent and accelerator. This further homogenizes the raw materials, removes air bubbles, and effectively improves the performance of perfluoroether rubber.

[0017] In some embodiments, the steps to obtain the composition include: first, mixing the perfluoroether rubber once, then adding filler to it and mixing it a second time to form a masterbatch, and then mixing the formed masterbatch with a vulcanizing agent for a third time.

[0018] In some embodiments, the temperature of the first mixing is 105℃-115℃ and the time of the first mixing is 30s-150s; the temperature of the second mixing is 120℃-160℃ and the time of the second mixing is 4min-6min; the temperature of the third mixing is 110℃ and the time of the third mixing is 30s-120s; the first mixing and / or the second mixing is internal mixing, and the third mixing is open milling; before mixing the masterbatch and the vulcanizing agent, the step of letting the masterbatch stand for at least 12h is also included.

[0019] In some embodiments, the vulcanization process includes performing a primary vulcanization and a secondary vulcanization sequentially, wherein the primary vulcanization is compression vulcanization and the secondary vulcanization is high-temperature vulcanization.

[0020] In some embodiments, the temperature of the primary vulcanization is 160℃-180℃, the time of the primary vulcanization is 10min-20min, and the pressure of the primary vulcanization is 10MPa-15MPa; the secondary vulcanization step includes holding at 180℃-220℃ for 6h-10h, raising the temperature to 270℃-320℃ at a heating rate of 8℃ / min-12℃ / min, and holding at 270℃-320℃ for 20h-30h; after the primary vulcanization and before the secondary vulcanization, the product of the primary vulcanization is further subjected to a step of standing for at least 12h.

[0021] The technical solution of this invention has the following advantages:

[0022] 1. The present invention provides a sealing composite material comprising perfluoroether rubber raw rubber and a vulcanizing agent, wherein the vulcanizing agent has the structure shown in formula (I).

[0023]

[0024] The perfluoroether rubber raw material possesses cyano reaction sites. Due to the high thermal and chemical stability of the benzene ring itself, its rigid structure can restrict the movement of molecular chains and reduce relaxation at high temperatures. Using a benzene ring structure as a vulcanizing agent for crosslinking with the perfluoroether rubber raw material containing cyano reaction sites offers the following advantages:

[0025] Firstly, the cyano group has high polarity and bond energy, and after crosslinking with anthracene-2,3,6,7-tetraamine, it can form a relatively stable chemical bond. This chemical bond can restrict the movement of molecular chains, making it more difficult for the material to undergo molecular chain slippage and deformation when heated; furthermore, there is a conjugation effect or electron cloud interaction between the cyano group and anthracene-2,3,6,7-tetraamine, which further enhances the stability of the crosslinked structure, thereby increasing the thermal decomposition temperature of the material and enabling it to maintain stable performance at higher temperatures.

[0026] Secondly, the presence of the cyano group gives the monomer a certain degree of chemical inertness, making it less likely to react with common chemical substances. When crosslinked with anthracene-2,3,6,7-tetraamine, the resulting crosslinked network structure can fix the cyano group within it, reducing the contact area between the cyano group and external chemical substances, and lowering the possibility of chemical reactions. At the same time, the rigid structure of anthracene-2,3,6,7-tetraamine also helps to improve the overall chemical stability of the material.

[0027] Thirdly, the cross-linking reaction can transform the raw perfluoroether rubber from a linear structure to a three-dimensional network structure, restricting the relative sliding between molecular chains, increasing the strength and hardness of the material, thereby improving the high-temperature cracking damage and further enhancing its high-temperature resistance.

[0028] Furthermore, the π-π stacking effect between benzene rings can also enhance the stability of the molecular chain. The more benzene rings there are, the stronger the rigidity of the formed perfluoroether rubber, resulting in increased material hardness. This invention uses anthracene-2,3,6,7-tetraamine as a vulcanizing agent to improve the heat resistance of the material while maintaining the hardness of the perfluoroether rubber.

[0029] 2. This invention provides a method for preparing a sealing composite material, comprising the following steps: mixing and vulcanizing various raw materials according to a certain ratio to obtain the sealing composite material. The method for preparing the sealing composite material provided by this invention has a simple process, and the resulting sealing composite material exhibits good performance.

[0030] 3. The present invention provides a method for preparing a sealing composite material. The steps of mixing the raw materials include first mixing the perfluoroether rubber raw rubber, then adding fillers and mixing it a second time to form a masterbatch, and finally mixing the formed masterbatch with a vulcanizing agent for a third time. This invention utilizes staged mixing, with additives added in each mixing stage, to fully disperse the raw materials for preparing the sealing composite material, thereby further improving the high-temperature resistance and mechanical properties of the resulting sealing composite material.

[0031] 4. The present invention provides a method for preparing a sealing composite material, wherein the vulcanization step includes sequentially performing a primary vulcanization and a secondary vulcanization, wherein the primary vulcanization is compression molding vulcanization and the secondary vulcanization is high-temperature vulcanization. The crosslinking units formed by the vulcanization system used in the present invention can greatly improve the high-temperature resistance of the sealing composite material, and at the same time ensure that the chemical bonds of the sealing composite material are not easily broken at high temperatures, thereby enhancing the stability of the molecular chain. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the chemical reaction process in the formation of the sealing composite material provided in Embodiment 1 of the present invention. Detailed Implementation

[0034] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0035] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0036] Example 1

[0037] This embodiment provides a method for preparing a sealing composite material, the specific steps and parameters of which are as follows:

[0038] (1) Set the internal mixer temperature to 110℃. After the internal mixer temperature stabilizes, add the perfluoroether rubber raw material (purchased from Solvay Group, containing cyano vulcanization reaction sites). Specifically, the perfluoroether rubber raw material includes tetrafluoroethylene, perfluoroalkyl vinyl ether, and perfluoro-4-cyanovinyl ether, which can be purchased directly. Add the perfluoroether rubber raw material to the mixing chamber and mix for 150 seconds until the torque stabilizes, completing one mixing process.

[0039] Then, the filler is put into the mixing chamber through the feeding port. After the feeding port is sealed by the top bolt, the mixture is mixed at 140°C for 5 minutes to obtain the masterbatch. The masterbatch is then discharged at a temperature of 140°C. The mass ratio of perfluoroether rubber raw rubber to filler is 100:20. The filler is carbon black N990 with a particle size range of 280nm-320nm. This completes the secondary mixing process.

[0040] Place the masterbatch on a two-roll mill with a roll gap of 0.1 mm and roll it through a triangular shape 6 times. Then adjust the roll gap to 1.5 mm and calender the sheet. Let the resulting masterbatch rest for more than 12 hours before use.

[0041] (2) Cool water is passed through the open mill, and the roll gap of the open mill is adjusted to 1.5 mm. The masterbatch is then fed into the open mill for calendering and softening. The masterbatch is then wrapped around the rolls. The vulcanizing agent anthracene-2,3,6,7-tetraamine (CAS No.: 64535-63-3) and the accelerator carbamide are gradually added and mixed. The mixing temperature is 110℃ and the time is 100s. The mass ratio of the perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:2:0.5 based on the mass of the perfluoroether rubber raw rubber in step (1). The rubber is cut and turned from side to side. After the mixture is evenly mixed, a composition is formed. The roll gap of the open mill is adjusted to 0.1 mm and passed through the mill 6 times. The roll gap of the open mill is then adjusted to 1.5 mm and calendered. The three mixing processes are completed and the mixture is left to stand for more than 12 hours for later use.

[0042] (3) The composition obtained in step (2) is placed in a mold, and the mold is placed in a flat vulcanizing machine for a first-stage molding vulcanization to obtain a first-stage vulcanized product. After the first-stage vulcanized product is left to stand for 12 hours, it is placed in an oven for a second-stage vulcanization to prepare a sealing composite material. The vulcanization temperature of the first-stage molding vulcanization is 170℃, the vulcanization time is 20 min, and the vulcanization pressure is 15 MPa. The processing technology of the second-stage vulcanization is to uniformly raise the oven temperature from 25℃ to 200℃ at a rate of 10℃ / min, hold it at 200℃ for 8 hours, raise it to 290℃ at a rate of 10℃ / hour, hold it at 290℃ for 24 hours, and then slowly lower it to 25℃.

[0043] See the schematic diagram of the sealing composite material formation process provided in this embodiment of the invention. Figure 1 .

[0044] Example 2

[0045] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:1:0.3.

[0046] Example 3

[0047] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1, except that the mass ratio of perfluoroether rubber raw rubber to filler in step (1) is 100:15.

[0048] Example 4

[0049] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (1), the mass ratio of perfluoroether rubber raw rubber to filler is 100:15, and in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:1:0.3.

[0050] Example 5

[0051] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:1:0.5.

[0052] Example 6

[0053] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:1.5:0.5.

[0054] Example 7

[0055] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:3:0.5.

[0056] Example 8

[0057] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:1.5:0.3.

[0058] Example 9

[0059] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (1), the mass ratio of perfluoroether rubber raw rubber to filler is 100:15, and in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:1.5:0.5.

[0060] Example 10

[0061] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (1), the mass ratio of perfluoroether rubber raw rubber to filler is 100:15, and in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:1.5:1.

[0062] Example 11

[0063] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as those in Example 1. The difference is that in step (1), the mass ratio of perfluoroether rubber raw rubber to filler is 100:15, and in step (2), the mass ratio of perfluoroether rubber, vulcanizing agent and accelerator is 100:1.5:2.

[0064] Example 12

[0065] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 9, except that the mass ratio of perfluoroether rubber raw rubber to filler in step (1) is 100:15.

[0066] Example 13

[0067] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 9, except that the mass ratio of perfluoroether rubber raw rubber to filler in step (1) is 100:30.

[0068] Example 14

[0069] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 9, except that the mass ratio of perfluoroether rubber raw rubber to filler in step (1) is 100:40.

[0070] Example 15

[0071] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that in step (1), the mass ratio of perfluoroether rubber raw rubber to filler is 100:30, and in step (2), the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator is 100:2:1.

[0072] Example 16

[0073] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1, except that the mass ratio of perfluoroether rubber raw rubber, vulcanizing agent and accelerator in step (2) is 100:2:1.

[0074] Example 17

[0075] (1) According to the mass ratio of perfluoroether rubber raw rubber, filler, vulcanizing agent and accelerator of 100:20:2:0.5, perfluoroether rubber raw rubber, carbon black N990, anthracene-2,3,6,7-tetraamine and carbamide are mixed to obtain a mixture;

[0076] Set the internal mixer temperature to 110℃. After the internal mixer temperature stabilizes, put the mixture into the internal mixing chamber and internally mix for 450s until the torque stabilizes. Then, place it on an open mill with a roll gap of 0.1mm and pass it through a triangular roll 6 times. Adjust the roll gap to 1.5mm and calender the sheet. Let the resulting composition stand for more than 12 hours for later use.

[0077] (2) The composition is placed in a mold, and the mold is placed in a flat vulcanizing machine for a first-stage molding vulcanization to obtain a first-stage vulcanized product. After the first-stage vulcanized product is left to stand for 12 hours, it is placed in an oven for a second-stage vulcanization to prepare a sealing composite material. The vulcanization temperature of the first-stage molding vulcanization is 170℃, the vulcanization time is 20 min, and the vulcanization pressure is 15 MPa. The processing technology of the second-stage vulcanization is to uniformly raise the oven temperature from 25℃ to 200℃, keep it at 200℃ for 8 hours, raise it to 290℃ at a rate of 10℃ per hour, keep it at 290℃ for 24 hours, and then slowly lower it to 25℃.

[0078] In step (1), under the condition of 110℃, the vulcanizing agent will undergo side reactions such as oxidation to a certain extent, and the vulcanizing agent cannot play its role. The resulting sealing composite material has poor mechanical properties.

[0079] Example 18

[0080] This embodiment provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Embodiment 1, except that the vulcanization process in step (3) is as follows:

[0081] The vulcanization temperature of the first-stage molding vulcanization is 170℃, the vulcanization time is 20min, and the vulcanization pressure is 15MPa; the second-stage vulcanization process involves uniformly raising the oven temperature from 25℃ to 200℃ at a rate of 10℃ / min, maintaining it at 250℃ for 24h, and then slowly cooling it down to 25℃.

[0082] The vulcanization temperature in this embodiment was too low, resulting in insufficient vulcanization density and poor mechanical properties of the resulting sealing composite material.

[0083] Comparative Example 1

[0084] This comparative example provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that an equal mass of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (CAS No. 83558-87-6) is used to replace anthracene-2,3,6,7-tetraamine in step (2).

[0085] Comparative Example 2

[0086] This comparative example provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that an equal mass of triallyl isocyanurate (CAS No. 1025-15-6) is used to replace anthracene-2,3,6,7-tetraamine in step (2), and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (CAS No. 78-63-7) is used as the initiator. The amount of initiator is 1 / 3 of the amount of vulcanizing agent.

[0087] Comparative Example 3

[0088] This comparative example provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that an anthracene-2,3,6,7-tetraamine in step (2) is replaced with an equal mass of 1,3,6,8-tetraaminopyrene (CAS: 28496-13-1).

[0089] Comparative Example 4

[0090] This comparative example provides a method for preparing a sealing composite material. The specific steps and parameters are the same as in Example 1. The difference is that an equal mass of 2,4,6,7-diaminonaphthalene (CAS:31656-47-0) is used to replace anthracene-2,3,6,7-tetraamine in step (2).

[0091] Experimental Example

[0092] The properties of the sealing composite materials prepared in Examples 1-18 and Comparative Examples 1-4 were tested, and the test results are shown in Table 1.

[0093] Among them, tensile strength and elongation at break are tested according to GB / T528-2009, hardness is tested according to GB / T531.1-2008, compression set at 290℃×70h is tested according to GB / T1683-2018, and high temperature resistance is tested according to GB / T19466.2-2004.

[0094] Table 1 Performance parameters of sealing composite materials

[0095]

[0096]

[0097] As shown in Table 1, compared with the use of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and triallyl isocyanurate as vulcanizing agents, and compared with the use of pyrene with four benzene rings and naphthalene with two benzene rings as the main structure of vulcanizing agents in Comparative Examples 3 and 4, the mechanical properties of the prepared sealing composite material are not ideal, especially in terms of high temperature resistance, which can only support a maximum temperature of 309℃. However, the sealing composite material formed by using anthracene-2,3,6,7-tetraamine as a vulcanizing agent in the embodiments of the present invention has a tensile strength greater than or equal to 13.8 MPa, an elongation at break greater than or equal to 170%, a hardness of 75HA, a compression set of less than or equal to 24% at 290℃×70h, and can withstand high temperatures above 310℃, even 336℃.

[0098] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A sealing composite material, characterized in that, It includes perfluoroether rubber raw material and a vulcanizing agent, said vulcanizing agent having the structure shown in formula (I). Equation (I); The perfluoroether rubber raw rubber has cyano reaction sites; The mass ratio of the perfluoroether rubber raw rubber to the vulcanizing agent is 100:1-3.

2. The sealing composite material according to claim 1, characterized in that, The crosslinking unit of the sealing composite material has the structure shown in formula (II). Formula (II).

3. The sealing composite material according to claim 2, characterized in that, The perfluoroether rubber raw rubber includes tetrafluoroethylene, perfluoroalkyl vinyl ether and a third monomer, wherein the third monomer includes perfluoro-4-cyanovinyl ether.

4. The sealing composite material according to claim 3, characterized in that, The mass ratio of the perfluoroether rubber raw rubber to the vulcanizing agent is 100:1-2.

5. The sealing composite material according to any one of claims 1-4, characterized in that, It also includes accelerators and fillers, The accelerator is carbonamide, and the filler is carbon black; The mass ratio of the perfluoroether rubber raw rubber, accelerator, and filler is 100:0.3-2:15-30.

6. The sealing composite material according to claim 5, characterized in that, The mass ratio of the perfluoroether rubber raw rubber, accelerator, and filler is 100:0.3-1:15-20.

7. A method for preparing a sealing composite material as described in any one of claims 1-6, characterized in that, Includes the following steps, The raw materials are mixed in a certain proportion to obtain a composition. The composition is placed in a mold and subjected to a vulcanization process to obtain a sealing composite material.

8. The method for preparing the sealing composite material according to claim 7, characterized in that, The steps to obtain the composition include: first, mixing the perfluoroether rubber raw rubber once, then adding filler to it and mixing it a second time to form a masterbatch, and then mixing the formed masterbatch with a vulcanizing agent for a third time.

9. The method for preparing the sealing composite material according to claim 8, characterized in that, The temperature for one mixing step is 105℃-115℃, and the mixing time is 30s-150s; The temperature for the second mixing is 120℃-160℃, and the time for the second mixing is 4min-6min; The temperature for the three mixing processes is 110℃, and the mixing time for the three processes is 30s-120s. One or two rounds of mixing is called intensive refining, and three rounds of mixing is called initial refining. Before mixing the masterbatch and vulcanizing agent, the process also includes a step of letting the masterbatch stand for at least 12 hours.

10. The method for preparing the sealing composite material according to claim 9, characterized in that, The vulcanization process includes a first vulcanization and a second vulcanization, wherein the first vulcanization is compression vulcanization and the second vulcanization is high-temperature vulcanization.

11. The method for preparing the sealing composite material according to claim 10, characterized in that, The temperature of the first vulcanization is 160℃-180℃, the time of the first vulcanization is 10min-20min, and the pressure of the first vulcanization is 10MPa-15MPa; The secondary vulcanization step includes maintaining the temperature at 180℃-220℃ for 6h-10h, then raising the temperature to 270℃-320℃ at a heating rate of 8℃ / min-12℃ / min, and maintaining the temperature at 270℃-320℃ for 20h-30h. The process after the first vulcanization and before the second vulcanization also includes a step of letting the product of the first vulcanization stand for at least 12 hours.

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