A preparation method of high-temperature resistant perfluoroether rubber

Abstract

The present invention discloses a preparation method of high-temperature resistant perfluoroether rubber, which comprises the following steps: mixing perfluoroether rubber, modified silicon carbide, and modified boron nitride nanosheets, then adding a crosslinking agent and mixing evenly, and performing segmented vulcanization to obtain high-temperature resistant perfluoroether rubber; wherein, in the preparation process of the modified boron nitride nanosheets, mixing nanosilicon carbide, boron nitride nanosheets, polymethyl methacrylate, a catalyst, and a solvent evenly, coating on the surface of a substrate, drying to form a film, sintering and crushing the film to obtain an intermediate; grafting and modifying the intermediate with a silane coupling agent containing a carbon-carbon double bond to obtain modified boron nitride nanosheets. The perfluoroether rubber prepared by the present invention has good thermal conductivity, high-temperature resistance, and plasma resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing components, and in particular to a method for preparing high-temperature resistant perfluoroether rubber. Background Art

[0002] In semiconductor manufacturing, the reliability of elastomeric seals is critical. Stopping production to replace seals is extremely costly. To avoid potential risks, the requirements for the cleanliness and purity of seals are very strict. At the same time, the seals must be able to work for a long time in plasma environments and high-temperature environments.

[0003] Perfluoroether rubber is typically produced by the co-polymerization of multiple monomers, including tetrafluoroethylene, a third-vulcanization monomer, and a perfluoroalkyl(oxy) vinyl ether. The perfluoroalkyl vinyl ether may be, for example, perfluoromethyl vinyl ether, while the perfluoroalkoxy vinyl ether may be, for example, perfluoro-2-propoxy vinyl ether.

[0004] Perfluoroelastomer (FFKM) is the most heat-resistant (up to 325°C) and chemical-resistant (over 1,800 different chemical agents) synthetic elastomer available today. However, it is also the most expensive synthetic elastomer, costing tens of thousands of yuan per kilogram, with the price of a product of equal weight approaching that of gold. FFKM is commonly used in the semiconductor industry. However, when exposed to high temperatures and plasma corrosion, FFKM is prone to cracking. Under tension and compression, these cracks can rapidly develop into through-cracks, leading to rubber failure. Therefore, further improvements in the heat and plasma resistance of FFKM are needed. Summary of the Invention

[0005] Based on the technical problems existing in the background technology, the present invention proposes a method for preparing high-temperature resistant perfluoroether rubber. The perfluoroether rubber prepared by the present invention has good thermal conductivity, high-temperature resistance and plasma resistance.

[0006] The present invention provides a method for preparing high-temperature resistant perfluoroether rubber, comprising the following steps: mixing perfluoroether rubber, modified silicon carbide, and modified boron nitride nanosheets, adding a crosslinking agent and mixing evenly, and vulcanizing in stages to obtain the high-temperature resistant perfluoroether rubber;

[0007] In the preparation process of modified boron nitride nanosheets, nano-silicon carbide, boron nitride nanosheets, polymethyl methacrylate, a catalyst and a solvent are mixed, coated on the surface of a substrate, dried into a film, sintered and crushed to obtain an intermediate; the intermediate is grafted and modified with a silane coupling agent containing a carbon-carbon double bond to obtain modified boron nitride nanosheets.

[0008] The third vulcanization point monomer of the perfluoroether rubber of the present invention is a bromine-containing vulcanization point monomer, such as bromotrifluoroethylene, 1-bromo-2,2-difluoroethylene, and the like.

[0009] Preferably, in the preparation process of the modified boron nitride nanosheets, the weight ratio of nano silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and catalyst is 2 - 2.5:10:3 - 4:0.4 - 0.5.

[0010] Preferably, in the preparation process of the modified boron nitride nanosheets, the catalyst is ferrocene.

[0011] Preferably, in the preparation process of the modified boron nitride nanosheets, the solvent is N-methylpyrrolidone.

[0012] Preferably, in the preparation process of the modified boron nitride nanosheets, sintering is carried out at 700 - 750 °C for 30 - 40 min.

[0013] Preferably, in the preparation process of the modified boron nitride nanosheets, sintering is carried out in an inert gas atmosphere.

[0014] Preferably, the modified silicon carbide is silicon carbide modified by a silane coupling agent containing a carbon-carbon double bond.

[0015] The above silane coupling agent containing a carbon-carbon double bond can be γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, etc.

[0016] Preferably, the weight ratio of the modified silicon carbide to the modified boron nitride nanosheets is 40 - 45:8 - 10.

[0017] Preferably, the weight ratio of perfluoroether rubber to the modified silicon carbide is 100:40 - 45.

[0018] Preferably, the weight ratio of perfluoroether rubber to the crosslinking agent is 100:3 - 4.

[0019] Preferably, the crosslinking agent is 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and triallyl isocyanurate.

[0020] The raw materials of the above high-temperature resistant perfluoroether rubber can also contain plasticizers, anti-aging agents, etc.

[0021] Preferably, vulcanization is carried out at 160 - 165 °C for 8 - 12 min, and secondary vulcanization is carried out at 200 - 220 °C for 20 - 24 h.

[0022] The present invention mixes nano silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and a catalyst to form a film, and then sinter-catalyzes the polymethyl methacrylate to transform into carbon nanotubes, and makes the carbon nanotubes uniformly distributed between the layers of boron nitride nanosheets, while the nano silicon carbide is uniformly distributed on the surface and between the layers of boron nitride nanosheets. The distribution states of the three can form interconnected heat conduction channels in the surface layer and interlayer gaps of the boron nitride nanosheets, thereby greatly improving the thermal conductivity of the boron nitride nanosheets; and the distribution states of the three can cooperate with each other to improve the plasma resistance performance; graft modification with a silane coupling agent containing carbon-carbon double bonds can improve its compatibility with perfluoroether rubber;

[0023] Moreover, the modified boron nitride nanosheets grafted with carbon-carbon double bonds and the modified silicon carbide grafted with carbon-carbon double bonds can, on the one hand, have good compatibility with perfluoroether rubber, and on the other hand, can cooperate with 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and triallyl isocyanurate, and graft-crosslink with the vulcanization points of perfluoroether rubber, so that the modified silicon carbide and the modified boron nitride nanosheets are uniformly distributed along the main chain of perfluoroether rubber to form continuous heat conduction channels and plasma barrier layers, which can transfer heat, thereby greatly improving the high temperature resistance and plasma resistance performance of perfluoroether rubber; and their uniform distribution along the main chain of perfluoroether rubber can greatly improve the toughness and strength of the rubber, and avoid the problem that the rubber is prone to cracks and breakage after being corroded by plasma. Detailed implementation manners

[0024] Next, the technical solutions of the present invention will be described in detail through specific examples, but it should be clearly stated that these examples are for illustrative purposes only and are not construed as limiting the scope of the present invention.

[0025] Example 1

[0026] A preparation method of high-temperature resistant perfluoroether rubber includes the following steps:

[0027] Mix nano silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and ferrocene according to a weight ratio of 2:10:3:0.4, then add them into N-methylpyrrolidone, disperse them by ultrasonic for 30 min, then stir for 4 h, and then coat them on the surface of the substrate and dry to form a film; then, in an argon atmosphere, sinter the film at 750 °C for 30 min, cool to room temperature and then crush to obtain an intermediate; [[ID=,19]]

[0028] Add the intermediate into an ethanol-water (90:10 v / v) solution of γ-methacryloxypropyltrimethoxysilane with a mass fraction of 5 wt%, stir at 60 °C for 1 h, centrifuge, wash with water, and dry to obtain modified boron nitride nanosheets;

[0029] Mix each raw material according to the weight ratio of perfluoroether rubber, γ-methacryloxypropyltrimethoxysilane modified silicon carbide, modified boron nitride nanosheet, plasticizer carnauba wax, and antioxidant RD of 100:45:8:5:1. Then, according to the weight ratio of perfluoroether rubber, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and triallyl isocyanurate of 100:1:3, add 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and triallyl isocyanurate and mix well. Cure at 165°C for 8 min, and then perform secondary curing at 220°C for 20 h to obtain high-temperature resistant perfluoroether rubber.

[0030] Example 2

[0031] A preparation method of high-temperature resistant perfluoroether rubber includes the following steps:

[0032] Mix nano silicon carbide, boron nitride nanosheet, polymethyl methacrylate, and ferrocene according to the weight ratio of 2.5:10:4:0.5. Then add them to N-methylpyrrolidone, disperse them by ultrasonic wave for 30 min, stir for 4 h, and then coat them on the surface of the substrate and dry to form a film. Then, in an argon atmosphere, sinter the film at 700°C for 40 min, cool to room temperature and then crush it to obtain an intermediate.

[0033] Add the intermediate to an ethanol-water (90:10 v / v) solution of γ-methacryloxypropyltrimethoxysilane with a mass fraction of 5 wt%, stir at 60°C for 1 h, centrifuge, wash with water, and dry to obtain modified boron nitride nanosheets.

[0034] Mix each raw material according to the weight ratio of perfluoroether rubber, γ-methacryloxypropyltrimethoxysilane modified silicon carbide, modified boron nitride nanosheet, plasticizer carnauba wax, and antioxidant RD of 100:40:10:5:1. Then, according to the weight ratio of perfluoroether rubber, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and triallyl isocyanurate of 100:1:2, add 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and triallyl isocyanurate and mix well. Cure at 160°C for 12 min, and then perform secondary curing at 200°C for 24 h to obtain high-temperature resistant perfluoroether rubber.

[0035] Example 3

[0036] A preparation method of high-temperature resistant perfluoroether rubber includes the following steps:

[0037] Mix nano silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and ferrocene in a weight ratio of 2.2:10:3.5:0.5, then add them to N-methylpyrrolidone, disperse them by ultrasonic for 30 min, stir for 4 h, then coat them on the surface of the substrate and dry to form a film; then sinter the film in an argon atmosphere at 730 °C for 35 min, break it after cooling to room temperature to obtain an intermediate;

[0038] Add the intermediate to an ethanol-water (90:10 v / v) solution of 5 wt% γ-methacryloxypropyltrimethoxysilane, stir at 60 °C for 1 h, centrifuge, wash with water, and dry to obtain modified boron nitride nanosheets;

[0039] Mix each raw material according to the weight ratio of perfluoroether rubber, γ-methacryloxypropyltrimethoxysilane modified silicon carbide, modified boron nitride nanosheets, plasticizer carnauba wax, and antioxidant RD of 100:42:9:5:1, and then according to the weight ratio of perfluoroether rubber, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and triallyl isocyanurate of 100:1:2.5, add 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and triallyl isocyanurate and mix evenly, vulcanize at 165 °C for 10 min, and then perform secondary vulcanization at 210 °C for 22 h to obtain high-temperature resistant perfluoroether rubber.

[0040] Comparative Example 1

[0041] A method for preparing high-temperature resistant perfluoroether rubber includes the following steps:

[0042] Without γ-methacryloxypropyltrimethoxysilane modified silicon carbide and modified boron nitride nanosheets, and the others are the same as in Example 3.

[0043] Comparative Example 2

[0044] A method for preparing high-temperature resistant perfluoroether rubber includes the following steps:

[0045] Replace "modified boron nitride nanosheets" with "γ-methacryloxypropyltrimethoxysilane modified silicon carbide", and the others are the same as in Example 3.

[0046] Comparative Example 3

[0047] A method for preparing high-temperature resistant perfluoroether rubber includes the following steps:

[0048] Replace "γ-methacryloxypropyltrimethoxysilane modified silicon carbide" with "modified boron nitride nanosheets", and the others are the same as in Example 3.

[0049] Comparative Example 4

[0050] A preparation method of high-temperature resistant perfluoroether rubber, comprising the following steps:

[0051] Add boron nitride nanosheets into an ethanol-water (90:10 v / v) solution of γ-methacryloxypropyltrimethoxysilane with a mass fraction of 5 wt%, stir at 60 °C for 1 h, centrifuge, wash with water, and dry to obtain modified boron nitride nanosheets; others are the same as in Example 3.

[0052] Take the perfluoroether rubbers prepared in Examples 1-3 and Comparative Examples 1-4, and detect their properties respectively. The results are shown in Table 1.

[0053] Plasma resistance experiment: Place the rubber on the reaction table of a plasma etching machine, with the heating plate temperature at 200 °C, RPS 6000W, the gas is NF3, and the flow rates are 3000 sccm respectively, and etch for 48 h; then detect the weight loss rate, cracks and compression set of the rubber.

[0054] Table 1 Detection results

[0055]

[0056] As can be seen from Table 1: The high-temperature resistant perfluoroether rubber prepared by the present invention has good high-temperature resistance, plasma resistance and mechanical properties.

[0057] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A method for preparing high-temperature resistant perfluoroether rubber, characterized in that: The method comprises the following steps: mixing perfluoroether rubber, modified silicon carbide and modified boron nitride nanosheets, adding a crosslinking agent and mixing evenly, and vulcanizing in sections to obtain high-temperature resistant perfluoroether rubber; In the preparation process of the modified boron nitride nanosheets, nano-silicon carbide, boron nitride nanosheets, polymethyl methacrylate, a catalyst and a solvent are mixed, coated on the surface of a substrate, dried into a film, sintered and crushed to obtain an intermediate; the intermediate is grafted and modified with a silane coupling agent containing a carbon-carbon double bond to obtain the modified boron nitride nanosheets; In the preparation process of modified boron nitride nanosheets, the weight ratio of nano-silicon carbide, boron nitride nanosheets, polymethyl methacrylate, and catalyst is 2-2.5:10:3-4:0.4-0.5; In the preparation process of modified boron nitride nanosheets, the catalyst is ferrocene; During the preparation of the modified boron nitride nanosheets, the sheets were sintered at 700-750°C for 30-40 minutes; During the preparation of the modified boron nitride nanosheets, sintering is performed in an inert gas atmosphere.

2. The method for preparing high temperature resistant perfluoroether rubber according to claim 1, characterized in that: During the preparation of the modified boron nitride nanosheets, the solvent is N-methylpyrrolidone.

3. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: Modified silicon carbide is silicon carbide modified by a silane coupling agent containing a carbon-carbon double bond.

4. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: The weight ratio of the modified silicon carbide to the modified boron nitride nanosheets is 40-45:8-10.

5. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: The weight ratio of perfluoroether rubber to modified silicon carbide is 100:40-45.

6. The method for preparing high temperature resistant perfluoroether rubber according to claim 1 or 2, characterized in that: The weight ratio of perfluoroether rubber to cross-linking agent is 100:3-4.

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