High-temperature-resistant perfluoroether rubber sealing element and preparation method thereof

Abstract

The invention discloses a preparation method of a high-temperature-resistant perfluoroether rubber sealing element, which comprises the following steps: uniformly mixing a perfluoroether raw rubber emulsion with a fluorine-containing silane coupling agent modified carbon nanotube, condensing, washing, drying and crushing to obtain particles; and spraying the dispersion liquid of the modified boron nitride nanosheets on the surfaces of the particles, drying, adding a cross-linking agent, mixing, molding, and carrying out segmented vulcanization to obtain the high-temperature-resistant perfluoroether rubber sealing element. The invention further discloses the high-temperature-resistant perfluoroether rubber sealing element which is prepared according to the preparation method of the high-temperature-resistant perfluoroether rubber sealing element. The perfluoroether rubber disclosed by the invention has three-dimensional heat-conducting network frames which are communicated with one another, so that the heat conductivity and the high-temperature resistance of the perfluoroether rubber can be greatly improved; and the three-dimensional network framework can improve the plasma barrier property and improve the plasma resistance of the rubber.

Description

Technical Field

[0001] The present invention relates to the technical field of seals, and particularly to a high-temperature resistant perfluoroether rubber seal and a preparation method thereof. Background Art

[0002] Semiconductors are indispensable components in our daily lives and are used in almost all electrical and electronic devices. In the field of semiconductor applications, rubber seals need to have excellent plasma resistance and high-temperature resistance when working under plasma conditions for a long time. Perfluoroether rubber is a high-performance sealing material, and its excellent performance has enabled it to be applied throughout the entire manufacturing system of semiconductor products.

[0003] However, at present, the high-temperature resistance and plasma resistance of perfluoroether rubber are still not high. After being corroded by high temperature and plasma, cracks are likely to occur, and during use, they are prone to develop into through cracks under extrusion or stretching, thus increasing the consumption of perfluoroether rubber sealing materials. Currently, perfluoroether rubber seals are one of the main consumables required for integrated circuit production. The consumption of perfluoroether rubber in the semiconductor industry ranks second among the consumables in wafer fabs, and the expenditure accounts for about 12.5% of the semiconductor wafer manufacturing consumable expenditure. Therefore, it is necessary to improve the high-temperature resistance and plasma resistance of perfluoroether rubber and reduce its consumption. Summary of the Invention

[0004] Based on the technical problems existing in the background art, the present invention proposes a high-temperature resistant perfluoroether rubber seal and a preparation method thereof. The high-temperature resistant perfluoroether rubber seal prepared by the present invention has an interconnected three-dimensional heat conduction network framework, which can greatly improve the thermal conductivity and high-temperature resistance of perfluoroether rubber; and this three-dimensional network framework can improve the barrier performance against plasma and enhance the plasma resistance of the rubber.

[0005] The present invention proposes a preparation method of a high-temperature resistant perfluoroether rubber seal, which includes the following steps: mixing a perfluoroether raw rubber emulsion with carbon nanotubes modified by a fluorosilane coupling agent, coagulating, washing, drying, and pulverizing to obtain fine particles; spraying a dispersion liquid of modified boron nitride nanosheets on the surface of the fine particles, drying, adding a crosslinking agent, and mixing and molding, and performing segmented vulcanization to obtain a high-temperature resistant perfluoroether rubber seal.

[0006] Preferably, the fluorosilane coupling agent is tridecafluorooctyltriethoxysilane.

[0007] Preferably, the modified boron nitride nanosheets are boron nitride nanosheets modified by a silane coupling agent containing a carbon-carbon double bond.

[0008] The above-mentioned boron nitride nanosheets modified with a silane coupling agent containing a carbon-carbon double bond can be purchased from the market or prepared by common methods in the art; the specific steps of its preparation method include: subjecting the boron nitride nanosheets to acid treatment to increase the hydroxyl groups on the surface of the boron nitride nanosheets, and then mixing them with the hydrolysis solution of the silane coupling agent containing a carbon-carbon double bond, and heating and grafting to obtain boron nitride nanosheets modified with a silane coupling agent containing a carbon-carbon double bond.

[0009] The above-mentioned silane coupling agent containing a carbon-carbon double bond can be vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, etc.

[0010] Preferably, the weight ratio of the perfluoroether raw rubber to the carbon nanotubes modified with a fluorosilane coupling agent is 100:0.8 - 1.2.

[0011] Preferably, the weight ratio of the perfluoroether raw rubber to the modified boron nitride nanosheets is 100:4 - 6.

[0012] Preferably, the weight ratio of the perfluoroether raw rubber to the crosslinking agent is 100:6 - 7.

[0013] Preferably, the crosslinking agent is a mixture of bis-25 vulcanizing agent and triallyl isocyanurate.

[0014] The weight ratio of the above-mentioned bis-25 vulcanizing agent to triallyl isocyanurate is 1:1.5 - 2.

[0015] Preferably, the solid content of the perfluoroether raw rubber emulsion is 50 - 60 wt%.

[0016] Preferably, the drying temperature is 90 - 110 °C.

[0017] The above-mentioned program for stepwise vulcanization is: vulcanizing at 165 - 175 °C for 10 - 15 min, and then performing secondary vulcanization at 250 - 260 °C for 18 - 24 h.

[0018] The particle size of the above-mentioned particles is 30 - 40 mesh.

[0019] In the dispersion of the above-mentioned modified boron nitride nanosheets, the mass fraction of the modified boron nitride nanosheets is 2 - 4 wt%, and the solvent of the dispersion can be water.

[0020] The present invention also provides a high-temperature resistant perfluoroether rubber seal, which is prepared according to the preparation method of the above-mentioned high-temperature resistant perfluoroether rubber seal.

[0021] In the present invention, carbon nanotubes modified with fluorosilane coupling agent are first mixed with perfluoroether raw rubber emulsion to prepare microparticles, so that the carbon nanotubes are evenly distributed in the perfluoroether raw rubber microparticles. Then, a dispersion liquid of boron nitride nanosheets grafted with carbon-carbon double bonds is sprayed on the surface of the microparticles, and dried at an appropriate temperature to copolymerize part of the carbon-carbon double bonds, so that the boron nitride nanosheets are coated on the surface of the microparticles; then a crosslinking agent is added for mixing and molding, and segmented vulcanization is carried out. The remaining carbon-carbon double bonds can participate in the crosslinking vulcanization of the perfluoroether rubber, so that the boron nitride nanosheets are tightly connected to the high-temperature resistant perfluoroether rubber seal. The boron nitride nanosheets can separate the rubber matrix into multiple tightly connected units, so as to form a three-dimensional network framework of boron nitride nanosheets uniformly distributed in the perfluoroether rubber matrix; and carbon nanotubes are also evenly distributed in the perfluoroether rubber of each unit, which are interconnected with the three-dimensional network framework of the boron nitride nanosheets to form an interconnected heat conduction network, thereby greatly improving the heat conductivity and heat resistance of the high-temperature resistant perfluoroether rubber seal; and this network structure can play a protective and barrier role on the perfluoroether rubber, improve its plasma resistance performance, and also improve the mechanical properties.

[0022] The method of the present invention can form a three-dimensional heat conduction network with uniform distribution in the perfluoroether rubber matrix with less carbon nanotubes and boron nitride nanosheets, and improve the heat resistance and plasma resistance performance of the perfluoroether rubber. Brief Description of the Drawings

[0023] Figure 1 It is a photograph of the high-temperature resistant perfluoroether rubber seal prepared in Example 3 after plasma etching.

[0024] Figure 2 It is a photograph of the high-temperature resistant perfluoroether rubber seal prepared in Comparative Example 2 after plasma etching.

[0025] Figure 3 It is a photograph of the high-temperature resistant perfluoroether rubber seal prepared in Comparative Example 3 after plasma etching. Detailed Description of the Invention

[0026] Next, the technical solutions of the present invention will be described in detail through specific examples. However, 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.

[0027] Example 1

[0028] A preparation method of a high-temperature resistant perfluoroether rubber seal includes the following steps:

[0029] Take a perfluoroether raw rubber latex with a solid content of 50 wt%, add an aqueous dispersion of carbon nanotubes modified with tridecafluorooctyltriethoxysilane, stir for 3 h to mix evenly, then salting out with an aqueous calcium chloride solution with a mass fraction of 1.5 wt% to cause the latex to coagulate and precipitate, filter, wash, dry, and pulverize to obtain fine particles with a particle size of 30 - 40 mesh;

[0030] Then spray an aqueous dispersion of boron nitride nanosheets modified with vinyltrimethoxysilane with a mass fraction of 2 wt% on the surface of the fine particles, dry at 110 °C, add a crosslinking agent and mix and mold, vulcanize at 165 °C for 15 min, and then perform secondary vulcanization at 250 °C for 24 h to obtain a high-temperature resistant perfluoroether rubber seal;

[0031] Among them, the weight ratio of perfluoroether raw rubber, carbon nanotubes modified with tridecafluorooctyltriethoxysilane, crosslinking agent, and boron nitride nanosheets modified with vinyltrimethoxysilane is 100:1.5:7:6;

[0032] The crosslinking agent is a mixture of bis-25 vulcanizing agent and triallyl isocyanurate;

[0033] The weight ratio of bis-25 vulcanizing agent and triallyl isocyanurate is 1:2.

[0034] Example 2

[0035] A preparation method of a high-temperature resistant perfluoroether rubber seal, comprising the following steps:

[0036] Take a perfluoroether raw rubber latex with a solid content of 60 wt%, add an aqueous dispersion of carbon nanotubes modified with tridecafluorooctyltriethoxysilane, stir for 3 h to mix evenly, then salting out with an aqueous calcium chloride solution with a mass fraction of 1.5 wt% to cause the latex to coagulate and precipitate, filter, wash, dry, and pulverize to obtain fine particles with a particle size of 30 - 40 mesh;

[0037] Then spray a dispersion (its solvent is N,N-dimethylformamide) of boron nitride nanosheets modified with vinyltrimethoxysilane with a mass fraction of 4 wt% on the surface of the fine particles, dry at 80 °C, add a crosslinking agent and mix and mold, vulcanize at 175 °C for 10 min, and then perform secondary vulcanization at 260 °C for 18 h to obtain a high-temperature resistant perfluoroether rubber seal;

[0038] Among them, the weight ratio of perfluoroether raw rubber, carbon nanotubes modified with tridecafluorooctyltriethoxysilane, crosslinking agent, and boron nitride nanosheets modified with vinyltrimethoxysilane is 100:2:6:4;

[0039] The crosslinking agent is a mixture of bis-25 vulcanizing agent and triallyl isocyanurate;

[0040] The weight ratio of bis-25 vulcanizing agent and triallyl isocyanurate is 1:1.5.

[0041] Example 3

[0042] A preparation method of a high-temperature resistant perfluoroether rubber seal, comprising the following steps:

[0043] Take a perfluoroether raw rubber latex with a solid content of 55 wt%, add an aqueous dispersion of carbon nanotubes modified with tridecafluorooctyltriethoxysilane, stir for 3 h to mix evenly, then salting out with an aqueous calcium chloride solution with a mass fraction of 1.5 wt% to cause the latex to coagulate and precipitate, filter, wash, dry, and pulverize to obtain fine particles with a particle size of 30-40 mesh;

[0044] Then spray a dispersion of boron nitride nanosheets modified with vinyltrimethoxysilane (the solvent is N,N-dimethylformamide) with a mass fraction of 3 wt% on the surface of the fine particles, dry at 110 °C, add a crosslinking agent and mix and mold, vulcanize at 170 °C for 10 min, and then perform secondary vulcanization at 255 °C for 24 h to obtain a high-temperature resistant perfluoroether rubber seal;

[0045] Wherein, the weight ratio of the perfluoroether raw rubber, carbon nanotubes modified with tridecafluorooctyltriethoxysilane, crosslinking agent, and boron nitride nanosheets modified with vinyltrimethoxysilane is 100:1.8:6.5:5;

[0046] The crosslinking agent is a mixture of bis-25 vulcanizing agent and triallyl isocyanurate;

[0047] The weight ratio of the bis-25 vulcanizing agent and triallyl isocyanurate is 1:1.7.

[0048] Comparative Example 1

[0049] A preparation method of a high-temperature resistant perfluoroether rubber seal, comprising the following steps:

[0050] When preparing the microspheres, do not add carbon nanotubes modified with tridecafluorooctyltriethoxysilane, and the others are the same as in Example 3.

[0051] Comparative Example 2

[0052] A preparation method of a high-temperature resistant perfluoroether rubber seal, comprising the following steps:

[0053] Do not spray the dispersion of boron nitride nanosheets modified with vinyltrimethoxysilane on the surface of the microspheres, and the others are the same as in Example 3.

[0054] Comparative Example 3

[0055] A preparation method of a high-temperature resistant perfluoroether rubber seal, comprising the following steps: Take a perfluoroether raw rubber latex with a solid content of 55 wt%, salting out with an aqueous calcium chloride solution with a mass fraction of 1.5 wt% to cause the latex to coagulate and precipitate, filter, wash, dry, and pulverize to obtain fine particles with a particle size of 30-40 mesh;

[0056] Mix the fine particles, carbon nanotubes modified with tridecafluorooctyltriethoxysilane, boron nitride nanosheets modified with vinyltrimethoxysilane, and a crosslinking agent, and then carry out kneading and molding. Cure at 170 °C for 10 min, and then carry out secondary curing at 255 °C for 24 h to obtain a high-temperature resistant perfluoroether rubber seal;

[0057] Among them, the weight ratio of the perfluoroether raw rubber, carbon nanotubes modified with tridecafluorooctyltriethoxysilane, the crosslinking agent, and boron nitride nanosheets modified with vinyltrimethoxysilane is 100:1:6.5:5;

[0058] The crosslinking agent is a mixture of bis-25 vulcanizing agent and triallyl isocyanurate;

[0059] The weight ratio of the bis-25 vulcanizing agent and triallyl isocyanurate is 1:1.7.

[0060] Take the high-temperature resistant perfluoroether rubber seals prepared in Examples 1-3 and Comparative Examples 1-3, and detect their properties respectively. The results are shown in Table 1.

[0061] Plasma etching conditions: Place the rubber on the reaction table of the plasma etching machine. The temperature of the heating plate is 220 °C, RPS is 5000 W, and the gas is NF 3 , and the flow rates are 2800 sccm respectively, and carry out etching for 48 h; then detect the weight loss rate and compression set of the rubber.

[0062] Table 1 Detection results

[0063]

[0064]

[0065] As can be seen from Table 1: Due to the three-dimensional network structure therein, the perfluoroether rubber of the present invention has good heat conduction, high-temperature resistance performance and good plasma etching resistance performance; and has good mechanical properties.

[0066] Typical pictures are as Figures 1 - 3 shown. Figure 1 It is a photograph of the plasma-etched high-temperature resistant perfluoroether rubber seal prepared in Example 3. Figure 2 It is a photograph of the plasma-etched high-temperature resistant perfluoroether rubber seal prepared in Comparative Example 2. Figure 3 It is a photograph of the plasma-etched high-temperature resistant perfluoroether rubber seal prepared in Comparative Example 3.

[0067] The above are only the preferred specific embodiments 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, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a high temperature resistant perfluoroether rubber seal, characterized in that: The method comprises the following steps: mixing a perfluoroether rubber latex and carbon nanotubes modified by a fluorinated silane coupling agent, and obtaining microparticles through agglomeration, washing, drying, and crushing; spraying a dispersion of modified boron nitride nanosheets on the surface of the microparticles, adding a crosslinking agent to mix and form after drying, and performing segmented vulcanization to obtain a high-temperature resistant perfluoroether rubber seal; The modified boron nitride nanosheets are boron nitride nanosheets modified by a silane coupling agent containing a carbon-carbon double bond.

2. The method for preparing the high temperature resistant perfluoroether rubber seal according to claim 1, characterized in that: The fluorine-containing silane coupling agent is tridecafluorooctyltriethoxysilane.

3. The method for preparing the high temperature resistant perfluoroether rubber seal according to claim 1, characterized in that: The weight ratio of the perfluoroether rubber to the carbon nanotubes modified by the fluorine-containing silane coupling agent is 100:1.5-2.

4. The method for preparing the high temperature resistant perfluoroether rubber seal according to claim 1, characterized in that: The weight ratio of the perfluoroether rubber to the modified boron nitride nanosheets is 100:4-6.

5. The method for preparing the high temperature resistant perfluoroether rubber seal according to claim 1, characterized in that: The weight ratio of the perfluoroether rubber to the cross-linking agent is 100:6-7.

6. The method for preparing the high temperature resistant perfluoroether rubber seal according to claim 1, characterized in that: The crosslinking agent is a mixture of bis-25 vulcanizing agent and triallyl isocyanurate.

7. The method for preparing the high temperature resistant perfluoroether rubber seal according to claim 1, characterized in that: The solid content of the perfluoroether raw rubber latex is 50-60wt%.

8. The method for preparing the high temperature resistant perfluoroether rubber seal according to claim 1, characterized in that: The drying temperature is 90-110℃.

9. A high temperature resistant perfluoroether rubber seal, characterized in that: The method for preparing a high temperature resistant perfluoroether rubber seal according to any one of claims 1 to 8 is used.

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