A high-cleanliness corrosion-resistant sealing ring and a preparation method and application thereof

Abstract

The application relates to the technical field of sealing ring processing, in particular to a high-cleanliness corrosion-resistant sealing ring and a preparation method and application thereof. The high-cleanliness corrosion-resistant sealing ring comprises an outer coating layer and an inner core, the inner core is composed of a rubber strip and a glue adhesive, the rubber strip is prepared from the following raw materials in parts by weight: 95-105 parts of fluorine rubber, 1.5-2.5 parts of a first vulcanizing agent, 4-5 parts of an activator, 35-45 parts of a filler, 0.4-0.6 parts of a lubricant and 1.3-1.8 parts of an additive. The sealing ring prepared by the application has high tensile strength and corrosion resistance, high sealing performance and long service life.

Description

Technical Field

[0001] This invention relates to the field of sealing ring processing technology, specifically to a high-cleanliness, corrosion-resistant sealing ring, its preparation method, and its application. Background Technology

[0002] As a core sealing element, sealing rings are widely used in key fields such as semiconductor manufacturing, biomedicine, aerospace, new energy, and high-end chemicals. Their sealing performance directly determines the system's operational reliability, media purity, and operational safety. In semiconductor etching scenarios, sealing rings need to be in contact with corrosive media such as strong acids, strong alkalis, and high-temperature plasmas for extended periods. While traditional materials such as nitrile rubber and ordinary fluororubber possess basic sealing capabilities, they suffer from a narrow range of corrosion resistance.

[0003] Patent CN116554622B discloses a modified polytetrafluoroethylene (PTFE) sealing ring and its preparation method. The modified PTFE sealing ring is made from raw materials comprising the following parts by weight: 60-80 parts PTFE; 10-15 parts spherical glass fiber; 4-8 parts polyimide; 2-5 parts wear-resistant additive; 5-10 parts reinforcing agent; and 1-5 parts processing aid. The preparation method involves uniformly mixing the raw materials, cold pressing, sintering and heat preservation, and secondary pressure setting during cooling to obtain the modified PTFE sealing ring. The modified PTFE sealing ring of this application not only possesses high hardness but also excellent elasticity, making it suitable for a wide range of applications.

[0004] Patent CN118580631B discloses a perfluororubber sealing ring and its preparation method, which is prepared from the following raw materials in parts by weight: 60-80 parts of perfluororubber, 20-30 parts of polyurethane resin, 20-40 parts of inorganic nanofiller, 3-5 parts of crosslinking agent, 1-2 parts of accelerator, 1-2 parts of vulcanizing agent, and 4-9 parts of modifier. Each part of the modifier is prepared by mixing maleic anhydride graft copolymer, siloxane copolymer, and dispersant in a weight ratio of (4-5):(6-9):5. The fluororubber sealing ring prepared by the above formula has good low-temperature resistance and can be used for a long time at -40℃.

[0005] With the upgrading of high-end manufacturing worldwide, the sealing requirements under extreme working conditions are becoming increasingly stringent. Traditional sealing ring materials and processes can no longer meet the dual requirements of high cleanliness and strong corrosion resistance, making technological upgrades imperative. Therefore, there is an urgent need in the market for a sealing ring with excellent sealing performance and corrosion resistance. Summary of the Invention

[0006] In view of the problems existing in the prior art, the purpose of this invention is to obtain a high-cleanliness and corrosion-resistant sealing ring with high mechanical properties and corrosion resistance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a high-cleanliness, corrosion-resistant sealing ring comprising an outer covering layer and an inner core, wherein the inner core is composed of a rubber strip and an adhesive, wherein the rubber strip is prepared by weight of the following raw materials: 95-105 parts of fluororubber, 1.5-2.5 parts of a first vulcanizing agent, 4-5 parts of an activator, 35-45 parts of filler, 0.4-0.6 parts of lubricant, and 1.3-1.8 parts of additives.

[0008] In some embodiments, the adhesive is prepared by comprising, by weight, the following raw materials: 90-110 parts of modified fluororubber, 4-5 parts of a second vulcanizing agent, and 230-270 parts of solvent.

[0009] In some embodiments, the method for preparing the modified fluororubber includes the following steps: (1) Under nitrogen protection, p-phenylenediamine and 2-amino-isophthalaldehyde were added to DMF and stirred for 20-30 min. Then, a catalyst was added and the reaction was carried out at 130-140 °C for 40-50 h. The compound was obtained after post-treatment. (2) Add the compound obtained in step (1) along with liquid fluororubber and dicyclohexylcarbodiimide into DMF and stir for 20-24 hours to obtain modified fluororubber.

[0010] In some embodiments, the molar ratio of p-phenylenediamine to 2-aminoisophthalaldehyde is 1:(1-1.2).

[0011] In some embodiments, the mass ratio of the compound to the fluororubber in step (2) is (0.3-0.7):1.

[0012] In some embodiments, the catalyst is glacial acetic acid.

[0013] In some embodiments, the second vulcanizing agent is a combination of triallyl isocyanurate and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane.

[0014] In some embodiments, the mass ratio of the triallyl isocyanurate to 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane is (1.8-2.2):1.

[0015] In some embodiments, the solvent is methyl isobutyl ketone.

[0016] In some embodiments, the method for preparing the adhesive includes the following steps: Add the modified fluororubber to the solvent and soak it at room temperature for 7-8 days. Then add the second vulcanizing agent and stir for 5-10 minutes. Let it stand for 25-35 minutes to obtain the product.

[0017] In some embodiments, the fluororubber is designated as P959 and manufactured by Solvay.

[0018] In some embodiments, the first vulcanizing agent is LUPEROX 101-45SP2, manufactured by ARKEMA.

[0019] In some embodiments, the activator is designated RHENOFIT TAIC / S and manufactured by Rhein Chemicals. In some embodiments, the lubricant is designated as WS280 and manufactured by STRUKTOL.

[0020] In some embodiments, the filler is a mixture of modified carbon black and barium sulfate in a mass ratio of (7-8):1.

[0021] In some embodiments, the carbon black is of type N990 and manufactured by Kencalborg, Canada; the barium sulfate is Xiangxing brand barium sulfate and manufactured by Guangxi Lianzhuang Technology Co., Ltd.

[0022] In some embodiments, the method for preparing the modified carbon black includes the following steps: A1. Under nitrogen protection, phloroglucinol, 6-bromohexanol, and potassium carbonate were added to anhydrous DMF and reacted at 45-50℃ for 25-30 h. After post-treatment, intermediate 1 was obtained. A2. Add intermediate 1 obtained in step A1, acrylic acid, p-toluenesulfonic acid, and dibutylhydroxytoluene to a toluene solution of DMF, react at 100-120℃ for 5-8 hours, and then perform post-treatment to obtain intermediate 2. A3. Add carbon black and silane coupling agent to ethanol solution, stir for 1-2 hours, then add initiator and intermediate 2 obtained in step A2, react at 60-70℃ for 1-2 hours, filter and wash to obtain modified carbon black.

[0023] In the field of chemical materials, especially high-performance sealing materials, the performance of fillers directly determines the mechanical strength, chemical inertness, processing characteristics, and reliability of the final product under harsh environments. In existing technologies, to improve the performance of the rubber matrix, traditional fillers such as unmodified carbon black and silica are typically used directly, or they are subjected to simple physical impregnation or silane coupling agent treatment. While these methods can improve the reinforcing effect to some extent, they are difficult to establish a strong and durable chemical interface between the filler and the rubber matrix. Especially under conditions of high cleanliness and extreme corrosion resistance, traditional filler treatment techniques have inherent defects such as weak interfacial bonding, easy precipitation of small molecule additives, and insufficient resistance to chemical media penetration.

[0024] This invention utilizes a nucleophilic substitution reaction between phloroglucinol and 6-bromohexanol, followed by esterification with acrylate to obtain a trifunctional compound containing three acrylate double bonds. Through in-situ graft polymerization, the polymer chains are firmly grafted onto the carbon black surface via chemical covalent bonds. The polymerizable double bonds at the ends and the polymerizable structure enable chemical bonding with silicone rubber and modified fluororubber matrices, increasing interfacial compatibility and significantly inhibiting filler agglomeration and interfacial debonding. Simultaneously, the chemically bonded polymer is less prone to migration and precipitation, meeting the stringent requirements of low-precipitate emissions in high-cleanliness applications. Furthermore, the polymer segments grafted onto the carbon black surface effectively block direct attack from corrosive media (such as acids, alkalis, and solvents) on the carbon black-rubber interface, significantly enhancing the overall corrosion resistance of the sealing ring. In addition, it improves the dispersibility of the filler in the rubber matrix, reduces the mixing viscosity, and facilitates smoother processing, thereby significantly improving the material's strength, abrasion resistance, and resistance to compression set while maintaining rubber elasticity.

[0025] In some embodiments, the molar ratio of phloroglucinol to 6-bromohexanol in step A1 is 1:(3-3.2).

[0026] In some embodiments, the mass ratio of intermediate 1 to acrylic acid in step A2 is (1.9-2.3):1.

[0027] In some embodiments, the mass ratio of carbon black, silane coupling agent and intermediate 2 in step A3 is 1:(0.1-0.5):(0.2-0.5).

[0028] In some embodiments, the silane coupling agent is a silane coupling agent containing double bonds.

[0029] In some embodiments, the initiator is any one of azobisisobutyronitrile, azobisisoheptanenitrile, and benzoyl peroxide.

[0030] In some embodiments, the additive is a mixture of DISMO 1822 and DISMO 18D in a mass ratio of 1:(0.3-0.6), and both are manufactured by Zhuhai Kemaowei New Materials Co., Ltd.

[0031] In some embodiments, the outer coating layer is a fluoropolymer tube.

[0032] A second aspect of this invention provides a method for preparing a high-cleanliness, corrosion-resistant sealing ring, comprising the following steps: S1. Preparation of rubber strips: 1) Set the internal mixer temperature to 70-80℃ and the speed to 30-40r / min. Add the fluororubber to the internal mixer and mix for 3-5 minutes. Add 4-5 parts of activator and continue mixing for 1-3 minutes. Then add the pretreated filler in 3-5 portions. After all the filler has been added, mix for 3-5 minutes. Add the lubricant and additives and mix for 1-2 minutes. Then lower the internal mixer temperature to 60-65℃ and adjust the speed to 20-25r / min. Add the first vulcanizing agent and mix for 1-2 minutes to obtain the rubber compound. Put the rubber compound into a preforming machine and extrude it at 50-60℃ to obtain round rubber strips. 2) Place the round rubber strip obtained in step 1) into a flat vulcanizing machine equipped with a mold, vulcanize at 13-17MPa and 155-165℃ for 9-12 minutes, release the pressure, take it out, cool it to room temperature, trim the edges, and then perform a second vulcanization and cool it to obtain a rubber strip. S2, Pipe insertion: The fluoropolymer tube is expanded by passing compressed air through it at 30-40℃ for 5-10 minutes, and then the rubber strip obtained in step S1 is inserted into the tube to obtain the rubber strip after tube insertion. S3, Hot vulcanized molded joint: Cut the rubber strip obtained after tube insertion in step S2 into a circular cross section, apply adhesive, and let it stand at room temperature for 50-70 minutes. Then align the two adhesive-coated surfaces and place them close together in a preheated mold. Vulcanize at 155-165℃ for 15-20 minutes to obtain a semi-finished product. S4. Hot melt welding: The fluoropolymer tube of the semi-finished product obtained in step S3 is fixed with a clamp, and then a counterforce is applied to make the two ends come together tightly. Then the interface is placed on an aluminum mold heated to 340-360℃. The upper and lower molds are semi-circular cylindrical structures. After 30-50 seconds, the joint is cooled and removed to obtain the sealing ring.

[0033] In some embodiments, the specific conditions for the secondary vulcanization are: maintaining at 225-235℃ for 3-5 hours.

[0034] A third aspect of the present invention provides an application of a high-cleanliness, corrosion-resistant sealing ring in semiconductors.

[0035] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention designs a sealing ring with an “outer layer covering and inner core composite” structure. Through the synergistic effect of structure and formula, it resists media penetration, adhesion and corrosion to the greatest extent. At the same time, the composite inner core is formed by rubber strips and adhesive, providing continuous and stable elastic rebound force and structural support, making up for the disadvantage that the covering layer may be too hard, and ensuring the tightness of the overall seal and the ability to adapt to deformation.

[0036] (2) This invention prepares a trifunctional compound containing three acrylate double bonds and grafts it onto the surface of carbon black, thereby increasing its interfacial compatibility with silicone rubber and modified fluororubber, greatly inhibiting filler agglomeration and interfacial debonding. At the same time, the polymer fixed by chemical bonds is not easy to migrate and precipitate, thus meeting the requirements of high cleanliness.

[0037] (3) This invention enhances the overall corrosion resistance of the sealing ring by grafting polymer segments onto the carbon black surface. In addition, it improves the dispersibility of the filler in the rubber matrix, reduces the mixing viscosity, and improves the processing performance, thereby significantly improving the strength, wear resistance and resistance to compression set of the material while maintaining the elasticity of the rubber. Attached Figure Description

[0038] Figure 1 The rubber strip after the tube is inserted in Example 1; Figure 2 The sealing ring is prepared in Example 1. Detailed Implementation

[0039] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0040] In the following examples and comparative examples, the compounds and related reagents used were all commercially available. Among them, the liquid carboxyl-terminated fluororubber CTFR, with a viscosity of 10-20 Pa·s (25°C), was purchased from Wuhan Kemic Biomedical Technology Co., Ltd.

[0041] Unless otherwise specified, the post-processing steps such as "washing", "drying", "filtration", "extraction", and "recrystallization" used below are routine operations for those skilled in the art, and can be selected according to actual operations.

[0042] Preparation Example 1 The preparation method of modified fluororubber includes the following steps: (1) Under nitrogen protection, 0.1 mol of p-phenylenediamine and 0.11 mol of 2-amino-isophthalaldehyde were added to 200 ml of DMF and stirred for 25 min. Then 60 g of 6 mol / L glacial acetic acid was added and reacted at 135 °C for 45 h. The temperature was lowered to room temperature, and the solid was washed with acetone and methanol after centrifugation and dried to obtain the compound. (2) Add 5g of the compound obtained in step (1), 10g of terminal carboxyl liquid fluororubber, and 5g of dicyclohexylcarbodiimide to 100ml of DMF, stir for 22h, wash with deionized water, extract with ethyl acetate, and dry to obtain modified fluororubber.

[0043] Preparation Example 2 The method for preparing the adhesive includes the following steps: By weight, 100 parts of modified fluororubber were added to 250 parts of methyl isobutyl ketone and soaked at room temperature for 7.5 days. Then, 4.5 parts of a second vulcanizing agent were added and stirred for 8 minutes. The second vulcanizing agent was a combination of triallyl isocyanurate and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane in a mass ratio of 2:1. The mixture was allowed to stand for 30 minutes to obtain the final product.

[0044] Preparation Example 3 The preparation method of modified carbon black-1 includes the following steps: A1. Under nitrogen protection, 0.1 mol of phloroglucinol, 0.31 mol of 6-bromohexanol, and 0.1 mol of potassium carbonate were added to 200 ml of anhydrous DMF and reacted at 48 °C for 28 h. The mixture was extracted with deionized water and ethyl acetate, and the organic phase was collected and recrystallized with hexane to obtain intermediate 1. A2. Add 6.3g of intermediate 1 obtained in step A1, 3g of acrylic acid, 0.05g of p-toluenesulfonic acid, and 0.02g of dibutylhydroxytoluene to 60ml of DMF toluene solution (V / V, 1:1), react at 110℃ for 6h, cool to 70℃, add 10wt% sodium bicarbonate solution to adjust pH to neutral, remove solvent by vacuum distillation, wash with deionized water, and dry to obtain intermediate 2; A3. Add 10g of carbon black N990 and 3g of γ-methacryloxypropyltrimethoxysilane to 100ml of 90wt% ethanol solution, stir for 1.5h, then add 0.1g of azobisisobutyronitrile and 4g of intermediate 2 obtained in step A2, react at 65℃ for 1.5h, filter and wash to obtain modified carbon black-1.

[0045] Preparation Example 4 The preparation method of modified carbon black-2 is the same as that in preparation example 3, except that the amount of 6-bromohexanol added in step A1 is 0.25 mol.

[0046] Preparation Example 5 The preparation method of modified carbon black-3 is the same as that of preparation example 3, except that the amount of intermediate 1 added in step A2 is 7.5g.

[0047] Preparation Example 6 The preparation method of modified carbon black-4 is the same as that in preparation example 3, except that the amount of intermediate 2 added in step A3 is 6g.

[0048] Preparation Example 7 The preparation method of modified carbon black-5 includes the following steps: 10g of carbon black N990 and 3g of γ-methacryloxypropyltrimethoxysilane were added to 100ml of 90wt% ethanol solution, stirred for 1.5h, filtered and washed to obtain modified carbon black-5.

[0049] Example 1 A high-cleanliness, corrosion-resistant sealing ring comprises an outer coating layer and an inner core. The inner core is composed of a rubber strip and an adhesive. The rubber strip is prepared by weight of the following raw materials: 100 parts of fluororubber P959, 2 parts of the first vulcanizing agent LUPEROX 101-45SP2, 4.5 parts of the activator RHENOFIT TAIC / S, 30 parts of filler, 0.5 parts of lubricant WS280, and 1.5 parts of additives. The filler is modified carbon black-1 and Xiangxing brand barium sulfate, with a mass ratio of 7.5:1; the additive is a mixture of DISMO 1822 and DISMO 18D, with a mass ratio of 1:0.5.

[0050] The method for preparing the high-cleanliness, corrosion-resistant sealing ring in this embodiment includes the following steps: S1. Preparation of rubber strips: 1) Set the internal mixer temperature to 75℃ and the speed to 35r / min. Add fluororubber P959 to the internal mixer and mix for 4 minutes. Add activator RHENOFIT TAIC / S and continue mixing for 2 minutes. Then add the pretreated filler in 4 batches. After all the filler is added, mix for 4 minutes. Add lubricant WS280 and additives and mix for 1.5 minutes. Then reduce the internal mixer temperature to 63℃ and adjust the speed to 23r / min. Add the first vulcanizing agent LUPEROX 101-45SP2 and mix for 1.5 minutes to obtain the rubber compound. Put the rubber compound into a preforming machine and extrude at 55℃ to obtain round rubber strips. 2) Place the round rubber strip obtained in step 1) into a flat vulcanizing machine equipped with a mold, vulcanize at 15MPa and 160℃ for 10min, release the pressure, take it out, cool it to room temperature, trim the edges, and then keep it at 230℃ for 4h for secondary vulcanization, cool it to obtain the rubber strip. S2, Pipe insertion: The PFA tube (wall thickness 0.6±0.1mm, inner diameter 5±0.5mm) was expanded by compressed air at 35℃ for 8 minutes. Then, the rubber strip obtained in step S1 was inserted into the tube to form the inserted rubber strip. Figure 1 As shown; S3, Hot vulcanized molded joint: Cut the rubber strip obtained after tube insertion in step S2 into a circular cross section, apply adhesive with a thickness of 1±0.5mm, let it stand at room temperature for 60 minutes, then align the two adhesive-coated surfaces and place them together in a preheated mold, and vulcanize at 160℃ for 18 minutes to obtain a semi-finished product. S4. Hot melt welding: The PFA tube of the semi-finished product obtained in step S3 is fixed with a clamp, and then a counterforce is applied to make the two ends tightly together. The joint is then placed on an aluminum mold heated to 350°C. The upper and lower molds are both semi-circular cylindrical structures. The joint is left to cool for 40 seconds, then removed to obtain the sealing ring. Figure 2 As shown.

[0051] Example 2 A high-cleanliness, corrosion-resistant sealing ring comprises an outer coating layer and an inner core. The inner core is composed of a rubber strip and an adhesive. The rubber strip is prepared by weight of the following raw materials: 95 parts of fluororubber P959, 1.5 parts of the first vulcanizing agent LUPEROX 101-45SP2, 4 parts of the activator RHENOFIT TAIC / S, 35 parts of filler, 0.4 parts of lubricant WS280, and 1.3 parts of additives. The filler is modified carbon black-1 and Xiangxing brand barium sulfate, with a mass ratio of 7:1; the additive is a mixture of DISMO 1822 and DISMO 18D, with a mass ratio of 1:0.3.

[0052] The method for preparing the high-cleanliness, corrosion-resistant sealing ring in this embodiment includes the following steps: S1. Preparation of rubber strips: 1) Set the internal mixer temperature to 70℃ and the speed to 30r / min. Add fluororubber P959 to the internal mixer and mix for 3min. Add activator RHENOFIT TAIC / S and continue mixing for 1min. Then add the pretreated filler in 3 batches. After all the filler is added, mix for 3min. Add lubricant WS280 and additives and mix for 1min. Then reduce the internal mixer temperature to 60℃ and adjust the speed to 20r / min. Add the first vulcanizing agent LUPEROX 101-45SP2 and mix for 1min to obtain the rubber compound. Put the rubber compound into a preforming machine and extrude at 50℃ to obtain round rubber strips. 2) Place the round rubber strip obtained in step 1) into a flat vulcanizing machine equipped with a mold, vulcanize at 13MPa and 165℃ for 9 minutes, release the pressure, take it out, cool it to room temperature, trim the edges, and then keep it at 225℃ for 5 hours for secondary vulcanization, cool it, and obtain the rubber strip. S2, Pipe insertion: The PFA tube (wall thickness 0.6±0.1mm, inner diameter 5±0.5mm) was expanded by passing compressed air through it at 30℃ for 10 minutes, and then the rubber strip obtained in step S1 was inserted into the tube to obtain the rubber strip after tube insertion. S3, Hot vulcanized molded joint: Cut the rubber strip obtained after tube insertion in step S2 into a circular cross section, apply adhesive with a thickness of 1±0.5mm, let it stand at room temperature for 50 minutes, then align the two adhesive-coated surfaces and place them together in a preheated mold, and vulcanize at 155℃ for 20 minutes to obtain a semi-finished product. S4. Hot melt welding: The PFA tube of the semi-finished product obtained in step S3 is fixed with a clamp, and then a counterforce is applied to make the two ends come together tightly. Then the interface is placed on an aluminum mold heated to 340°C. The upper and lower molds are semi-circular cylindrical structures. After 50 seconds, the joint is cooled and removed to obtain the sealing ring.

[0053] Example 3 A high-cleanliness, corrosion-resistant sealing ring comprises an outer coating layer and an inner core. The inner core is composed of a rubber strip and an adhesive. The rubber strip is prepared by weight of the following raw materials: 105 parts of fluororubber P959, 2.5 parts of the first vulcanizing agent LUPEROX 101-45SP2, 5 parts of the activator RHENOFIT TAIC / S, 45 parts of filler, 0.6 parts of lubricant WS280, and 1.8 parts of additives. The filler is modified carbon black-1 and Xiangxing brand barium sulfate, with a mass ratio of 8:1; the additive is a mixture of DISMO 1822 and DISMO 18D, with a mass ratio of 1:0.6.

[0054] The method for preparing the high-cleanliness, corrosion-resistant sealing ring in this embodiment includes the following steps: S1. Preparation of rubber strips: 1) Set the internal mixer temperature to 80℃ and the speed to 40r / min. Add fluororubber P959 to the internal mixer and mix for 5 minutes. Add activator RHENOFIT TAIC / S and continue mixing for 3 minutes. Then add the pretreated filler in 5 portions. After all the filler is added, mix for 5 minutes. Add lubricant WS280 and additives and mix for 2 minutes. Then reduce the internal mixer temperature to 65℃ and adjust the speed to 25r / min. Add the first vulcanizing agent LUPEROX 101-45SP2 and mix for 2 minutes to obtain the rubber compound. Put the rubber compound into a preforming machine and extrude at 60℃ to obtain round rubber strips. 2) Place the round rubber strip obtained in step 1) into a flat vulcanizing machine equipped with a mold, vulcanize at 17MPa and 155℃ for 12min, release the pressure, take it out, cool it to room temperature, trim the edges, and then keep it at 235℃ for 3h for secondary vulcanization, cool it, and obtain the rubber strip. S2, Pipe insertion: The PFA tube (wall thickness 0.6±0.1mm, inner diameter 5±0.5mm) is expanded for 5 minutes by passing compressed air through it at 40℃, and then the rubber strip obtained in step S1 is inserted into the tube to obtain the rubber strip after tube insertion. S3, Hot vulcanized molded joint: Cut the rubber strip obtained after tube insertion in step S2 into a circular cross section, apply adhesive with a thickness of 1±0.5mm, place at room temperature for 60 minutes, then align the two adhesive-coated surfaces and place them together in a preheated mold, and vulcanize at 165℃ for 15 minutes to obtain a semi-finished product. S4. Hot melt welding: The fluoropolymer tube of the semi-finished product obtained in step S3 is fixed with a clamp, and then a counterforce is applied to make the two ends come together tightly. Then the interface is placed on an aluminum mold heated to 360°C. The upper and lower molds are semi-circular cylindrical structures. After 30 seconds, the joint is cooled and removed to obtain the sealing ring.

[0055] Example 4 A high-purity, corrosion-resistant sealing ring and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified carbon black-1 is replaced with modified carbon black-2 in equal amounts.

[0056] Example 5 A high-purity, corrosion-resistant sealing ring and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified carbon black-1 is replaced with modified carbon black-3 in equal amounts.

[0057] Example 6 A high-purity, corrosion-resistant sealing ring and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified carbon black-1 is replaced with modified carbon black-4 in equal amounts.

[0058] Example 7 A high-purity, corrosion-resistant sealing ring and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified carbon black-1 is replaced with modified carbon black-5 in equal amounts.

[0059] Example 8 A high-purity, corrosion-resistant sealing ring and its preparation method are described. The specific implementation method is the same as in Example 1, except that modified carbon black-1 is replaced with carbon black N990 in equal amounts.

[0060] Comparative Example 1 A high-purity, corrosion-resistant sealing ring and its preparation method are disclosed. The specific implementation method is the same as in Example 1, except that the modified fluororubber is replaced with an equal amount of liquid-terminated carboxyl fluororubber.

[0061] Comparative Example 2 A high-cleanliness, corrosion-resistant sealing ring is composed of a rubber strip and an adhesive. The rubber strip, by weight, comprises the following raw materials: 100 parts of fluororubber P959, 2 parts of the first vulcanizing agent LUPEROX 101-45SP2, 4.5 parts of the activator RHENOFIT TAIC / S, 30 parts of filler, 0.5 parts of lubricant WS280, and 1.5 parts of additives. The filler is modified carbon black-1 and Xiangxing brand barium sulfate, with a mass ratio of 7.5:1; the additive is a mixture of DISMO 1822 and DISMO 18D, with a mass ratio of 1:0.5.

[0062] The method for preparing the high-cleanliness, corrosion-resistant sealing ring in this embodiment includes the following steps: S1. Preparation of rubber strips: 1) Set the internal mixer temperature to 75℃ and the speed to 35r / min. Add fluororubber P959 to the internal mixer and mix for 4 minutes. Add activator RHENOFIT TAIC / S and continue mixing for 2 minutes. Then add the pretreated filler in 4 batches. After all the filler is added, mix for 4 minutes. Add lubricant WS280 and additives and mix for 1.5 minutes. Then reduce the internal mixer temperature to 63℃ and adjust the speed to 23r / min. Add the first vulcanizing agent LUPEROX 101-45SP2 and mix for 1.5 minutes to obtain the rubber compound. Put the rubber compound into a preforming machine and extrude at 55℃ to obtain round rubber strips. 2) Place the round rubber strip obtained in step 1) into a flat vulcanizing machine equipped with a mold, vulcanize at 15MPa and 160℃ for 10min, release the pressure, take it out, cool it to room temperature, trim the edges, and then keep it at 230℃ for 4h for secondary vulcanization, cool it to obtain the rubber strip. S2, Hot vulcanized molded joints and hot melt welding: Cut the rubber strip obtained in step S1 into a circular cross section, apply adhesive to it with a thickness of 1±0.5mm, and let it sit at room temperature for 60 minutes. Then, align the two adhesive-coated surfaces and place them close together in a preheated mold. Cure at 160℃ for 18 minutes and remove to obtain the sealing ring.

[0063] Comparative Example 3 A high-cleanliness, corrosion-resistant sealing ring is composed of a rubber strip and an adhesive. The rubber strip is prepared by weight of the following raw materials: 100 parts of premixed adhesive FOR7353 (manufacturer Solvay), 4.5 parts of activator RHENOFIT TAIC / S, 30 parts of filler, 0.5 parts of lubricant WS280, and 1.5 parts of additives. The filler is modified carbon black-1 and Xiangxing brand barium sulfate, with a mass ratio of 7.5:1; the additive is a mixture of DISMO 1822 and DISMO 18D, with a mass ratio of 1:0.5.

[0064] The method for preparing the high-cleanliness, corrosion-resistant sealing ring in this embodiment includes the following steps: S1. Preparation of rubber strips: 1) Set the internal mixer temperature to 75℃ and the speed to 35r / min. Add the premixed rubber FOR7353 to the internal mixer and mix for 4 minutes. Add the activator RHENOFIT TAIC / S and continue mixing for 2 minutes. Then add the pretreated filler in 4 batches. After all the filler is added, mix for 4 minutes. Add the lubricant WS280 and the additives and mix for 1.5 minutes. Then reduce the internal mixer temperature to 63℃ and adjust the speed to 23r / min. Mix for 1.5 minutes to obtain the rubber compound. Put the rubber compound into the preforming machine and extrude at 55℃ to obtain round rubber strips. 2) Place the round rubber strip obtained in step 1) into a flat vulcanizing machine equipped with a mold, vulcanize at 15MPa and 160℃ for 10min, release the pressure, take it out, cool it to room temperature, trim the edges, and then keep it at 230℃ for 4h for secondary vulcanization, cool it to obtain the rubber strip. S2, Hot vulcanized molded joints and hot melt welding: Cut the rubber strip obtained in step S1 into a circular cross section, apply adhesive to it with a thickness of 1±0.5mm, and let it sit at room temperature for 60 minutes. Then, align the two adhesive-coated surfaces and place them close together in a preheated mold. Cure at 160℃ for 18 minutes and remove to obtain the sealing ring.

[0065] Comparative Example 4 A high-cleanliness, corrosion-resistant sealing ring is composed of a rubber strip and an adhesive. The rubber strip, by weight, comprises the following raw materials: 100 parts of fluororubber PFR5920M (manufacturer: Solvay), 2 parts of the first vulcanizing agent LUPEROX101-45SP2, 4.5 parts of the activator RHENOFIT TAIC / S, 30 parts of filler, 0.5 parts of lubricant WS280, and 1.5 parts of additives. The filler is modified carbon black-1 and Xiangxing brand barium sulfate, with a mass ratio of 7.5:1; the additive is a mixture of DISMO 1822 and DISMO 18D, with a mass ratio of 1:0.5.

[0066] The method for preparing the high-cleanliness, corrosion-resistant sealing ring in this embodiment includes the following steps: S1. Preparation of rubber strips: 1) Set the internal mixer temperature to 75℃ and the speed to 35r / min. Add the fluororubber PFR5920M to the internal mixer and mix for 4 minutes. Add the activator RHENOFIT TAIC / S and continue mixing for 2 minutes. Then add the pretreated filler in 4 batches. After all the filler is added, mix for 4 minutes. Add the lubricant WS280 and the additives and mix for 1.5 minutes. Then reduce the internal mixer temperature to 63℃ and adjust the speed to 23r / min. Add the first vulcanizing agent LUPEROX 101-45SP2 and mix for 1.5 minutes to obtain the rubber compound. Put the rubber compound into the preforming machine and extrude at 55℃ to obtain round rubber strips. 2) Place the round rubber strip obtained in step 1) into a flat vulcanizing machine equipped with a mold, vulcanize at 15MPa and 160℃ for 10min, release the pressure, take it out, cool it to room temperature, trim the edges, and then keep it at 230℃ for 4h for secondary vulcanization, cool it to obtain the rubber strip. S2, Hot vulcanized molded joints and hot melt welding: Cut the rubber strip obtained in step S1 into a circular cross section, apply adhesive to it with a thickness of 1±0.5mm, and let it sit at room temperature for 60 minutes. Then, align the two adhesive-coated surfaces and place them close together in a preheated mold. Cure at 160℃ for 18 minutes and remove to obtain the sealing ring.

[0067] Performance testing The sealing rings obtained in each embodiment were subjected to the following tests: 1. Tensile strength: The sealing ring was tested for tensile strength in accordance with the national recommended standard GB / T528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber" at a tensile speed of 500 mm / min.

[0068] 2. Compression stress relaxation test: The sealing ring was subjected to compression stress relaxation test according to the national recommended standard GB / T 7759.1-2015 Determination of compression set of vulcanized rubber or thermoplastic rubber - Part 1: Under normal and high temperature conditions. The compression amount was 15% and the compression was carried out at room temperature (23℃) for 72 hours.

[0069] 3. Corrosion resistance: In accordance with GB / T1690-2010 Test method for liquid resistance of vulcanized rubber or thermoplastic rubber, the sealing ring was immersed in 30wt% H2SO4 solution and 50wt% NaOH solution for 72h respectively, and the compression set test was carried out again in accordance with the above method for compression stress relaxation test.

[0070] The test results are shown in Table 1: Table 1 As shown in Table 1, the sealing rings prepared in Examples 1-3 have high mechanical properties and good corrosion resistance. A comparison of the data from Example 4 and Example 1 shows that changing the ratio of phloroglucinol to 6-bromohexanol may alter compatibility with other substrates, resulting in a decrease in all properties. A comparison of the data from Example 5 and Example 1 shows that changing the ratio of intermediate 1 to acrylic acid may alter the functionality of intermediate 1, leading to a decrease in both corrosion resistance and mechanical properties of the sealing ring. A comparison of Example 6 and Example 1 shows that changing the ratio of carbon black, silane coupling agent, and intermediate 2 may result in excessive grafting, making it difficult for the filler to disperse in the rubber compound, increasing the mixing viscosity, affecting uniformity, and causing a decrease in mechanical properties. A comparison of Examples 7 and 8 with Example 1 shows that using carbon black or silane-modified carbon black directly as filler, respectively, results in a decrease in all properties of the sealing ring. A comparison of Comparative Example 1 with Example 1 shows that directly using liquid-terminated carboxyl fluororubber reduces the corrosion resistance of the sealing ring.

[0071] 2. Plasma etching was performed using an ICP etching machine with a power of 1000W, a test time of 180 minutes, a test temperature of 200℃, and process gases of NF3 (50 sccm) and O2 (150 sccm). The test data are shown in Table 2. Table 2 As can be seen from the data in Table 2, the rubber ring prepared by this invention has good corrosion resistance and is suitable for the semiconductor field.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present application in any way. Although the present application discloses the preferred embodiment as described above, it is not intended to limit the present application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of the present application using the disclosed technical content are equivalent to equivalent implementation cases. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention are still within the scope of the technical solution.

Claims

1. A high-cleanliness, corrosion-resistant sealing ring, characterized in that, It comprises an outer coating layer and an inner core, wherein the inner core is composed of a rubber strip and an adhesive, wherein the rubber strip is prepared by weight of the following raw materials: 95-105 parts of fluororubber, 1.5-2.5 parts of a first vulcanizing agent, 4-5 parts of an activator, 35-45 parts of filler, 0.4-0.6 parts of lubricant, and 1.3-1.8 parts of additives.

2. The high-cleanliness, corrosion-resistant sealing ring according to claim 1, characterized in that, The adhesive is prepared by means of the following raw materials in parts by weight: 90-110 parts of modified fluororubber, 4-5 parts of second vulcanizing agent, and 230-270 parts of solvent.

3. The high-cleanliness, corrosion-resistant sealing ring according to claim 1, characterized in that, The filler is a mixture of modified carbon black and barium sulfate, with a mass ratio of (7-8):

1.

4. The high-cleanliness, corrosion-resistant sealing ring according to claim 3, characterized in that, The method for preparing the modified carbon black includes the following steps: A1. Under nitrogen protection, phloroglucinol, 6-bromohexanol, and potassium carbonate were added to anhydrous DMF and reacted at 45-50℃ for 25-30 h. The reaction was quenched and then post-treated to obtain intermediate 1. A2. Add intermediate 1 obtained in step A1, acrylic acid, p-toluenesulfonic acid, and dibutylhydroxytoluene to a toluene solution of DMF, react at 100-120℃ for 5-8 hours, and then perform post-treatment to obtain intermediate 2. A3. Add carbon black and silane coupling agent to ethanol solution, stir for 1-2 hours, then add initiator and intermediate 2 obtained in step A2, react at 60-70℃ for 1-2 hours, filter and wash to obtain modified carbon black.

5. The high-cleanliness, corrosion-resistant sealing ring according to claim 4, characterized in that, The molar ratio of phloroglucinol to 6-bromohexanol in step A1 is 1:(3-3.2).

6. The high-cleanliness, corrosion-resistant sealing ring according to claim 4, characterized in that, The mass ratio of intermediate 1 to acrylic acid in step A2 is (1.9-2.3):

1.

7. The high-cleanliness, corrosion-resistant sealing ring according to claim 4, characterized in that, The mass ratio of carbon black, silane coupling agent and intermediate 2 in step A3 is 1:(0.1-0.5):(0.2-0.5).

8. A method for preparing a high-cleanliness, corrosion-resistant sealing ring according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Preparation of rubber strips: 1) Set the internal mixer temperature to 70-80℃ and the speed to 30-40r / min. Add the fluororubber to the internal mixer and mix for 3-5 minutes. Add 4-5 parts of activator and continue mixing for 1-3 minutes. Then add the pretreated filler in 3-5 portions. After all the filler has been added, mix for 3-5 minutes. Add the lubricant and additives and mix for 1-2 minutes. Then lower the internal mixer temperature to 60-65℃ and adjust the speed to 20-25r / min. Add the first vulcanizing agent and mix for 1-2 minutes to obtain the rubber compound. Put the rubber compound into a preforming machine and extrude it at 50-60℃ to obtain round rubber strips. 2) Place the round rubber strip obtained in step 1) into a flat vulcanizing machine equipped with a mold, vulcanize at 13-17MPa and 155-165℃ for 9-12 minutes, release the pressure, take it out, cool it to room temperature, trim the edges, and then perform a second vulcanization and cool it to obtain a rubber strip. S2, Pipe insertion: The fluoropolymer tube is expanded by passing compressed air through it at 30-40℃ for 5-10 minutes, and then the rubber strip obtained in step S1 is inserted into the tube to obtain the rubber strip after tube insertion. S3, Hot vulcanized molded joint: Cut the rubber strip obtained after tube insertion in step S2 into a circular cross section, apply adhesive, and let it stand at room temperature for 50-70 minutes. Then align the two adhesive-coated surfaces and place them close together in a preheated mold. Vulcanize at 155-165℃ for 15-20 minutes to obtain a semi-finished product. S4. Hot melt welding: The fluoropolymer tube of the semi-finished product obtained in step S3 is fixed with a clamp, and then a counterforce is applied to make the two ends come together tightly. Then the interface is placed on an aluminum mold heated to 340-360℃. The upper and lower molds are semi-circular cylindrical structures. After 30-50 seconds, the joint is cooled and removed to obtain the sealing ring.

9. The method for preparing the high-cleanliness, corrosion-resistant sealing ring according to claim 8, characterized in that, The specific conditions for the secondary vulcanization are: maintaining at 225-235℃ for 3-5 hours.

10. The application of a high-cleanliness, corrosion-resistant sealing ring according to any one of claims 1-7 or a sealing ring obtained by the preparation method according to claims 8 / 9 in semiconductors.

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