Polymer sealing ring and preparation method thereof

Abstract

The invention discloses a polymer sealing ring and a preparation method thereof, and relates to the technical field of polymer materials. The high-temperature-resistant fluororubber sealing gasket is prepared from the following raw materials in percentage by mass: 30 to 50 percent of fluorinated modified silicone rubber, 15 to 25 percent of fluororubber, 7.2 to 16.4 percent of hybrid white carbon black, 2.5 to 6 percent of hydroxyl silicone oil, 8 to 11 percent of plasma fluorinated modified aluminum oxide, 4 to 8 percent of carbon black, 0.8 to 1.4 percent of palm wax, 0.8 to 1.4 percent of internal release agent, 1 to 2 percent of vulcanizing agent, 3 to 5 percent of triallyl isocyanurate and 0.5 to 1 percent of anti-aging agent. The fluorinated modified silicone rubber is prepared by grafting C2-18-perfluoroalkyl iodoethane on a silicone rubber side chain, so that the low temperature resistance of the silicone rubber is effectively improved, and the phenomenon that methyl vinyl silicone rubber is easy to crystallize at low temperature is successfully inhibited; the sealing ring material has good performance at high and low temperatures, and the use temperature range of the sealing ring material is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of polymer material technology, and in particular to a polymer sealing ring and a preparation method thereof. Background Art

[0002] Sealing rings are elastic, ring-shaped components widely used in industry and everyday life, primarily to prevent fluid or gas leakage and ensure the sealing performance of equipment and systems. Polymer sealing rings are made from polymers such as rubber, silicone rubber, fluororubber, and polytetrafluoroethylene. Polymer materials are ideal for sealing rings due to their unique properties, such as excellent elasticity, wear resistance, and chemical resistance. Compared to traditional metal seals, polymer sealing rings offer advantages such as light weight, low cost, and easy processing. These properties make polymer sealing rings indispensable in modern industry, making them key components for ensuring safe equipment operation and improving production efficiency.

[0003] However, polymer seals often face a series of technical challenges in different temperature environments. For example, due to temperature and pressure fluctuations in high-temperature environments, conventional rubber seals are prone to aging, deformation, and hardening, leading to reduced sealing performance and even failure. With the continuous advancement of technology, the formulation and manufacturing technology of polymer seal materials have undergone significant evolution, especially in the use of fillers and additives. These improvements have significantly improved the temperature resistance of polymer seal materials.

[0004] For related technology, reference may be made to the Chinese invention patent with authorization announcement number CN116751414B, which discloses a high-temperature resistant rubber sealing ring and a preparation method thereof. The raw materials include, by weight: 100 parts of rubber, 4-9 parts of activator, 1-2 parts of co-activator, 1-4 parts of chemical antioxidant, 0.5-1.5 parts of physical antioxidant, 70-90 parts of reinforcing agent, 3-8 parts of plasticizer, 10-15 parts of hydrogenated dimer fatty acid, 4-10 parts of ferric chloride, 2-5 parts of lipoic acid, 3-5 parts of cross-linking agent DCP, and 1-2 parts of accelerator DM.

[0005] Regarding the aforementioned related technologies, the inventors believe that while the addition of fillers and additives can effectively improve the high-temperature resistance of polymer seals, many fillers, due to their large specific surface area, tend to aggregate within the rubber matrix. This not only leads to uneven local performance in the seal but can also cause stress concentration, thereby reducing the material's service life. Furthermore, interfacial defects between the filler and the rubber matrix can affect load transfer efficiency, further reducing the overall performance of the material. Excessive fillers can also impair the rubber's elasticity, wear resistance, or processing properties. Summary of the Invention

[0006] In order to solve the above technical problems, the present application provides a polymer sealing ring and a preparation method thereof.

[0007] The present application provides a polymer sealing ring, which adopts the following technical solution:

[0008] A polymer sealing ring comprises, by mass percentage, 30-50% of fluorinated modified silicone rubber, 15-25% of fluororubber, 7.2-16.4% of hybrid white carbon black, 2.5-6% of hydroxy silicone oil, 8-11% of plasma fluorinated modified alumina, 4-8% of carbon black, 0.8-1.4% of palm wax, 0.8-1.4% of internal mold release agent, 1-2% of vulcanizing agent, 3-5% of triallyl isocyanurate, and 0.5-1% of antioxidant.

[0009] Preferably, the raw materials include, by mass percentage, 40% fluorinated modified silicone rubber, 20% fluororubber, 11.9% hybrid silica, 4.2% hydroxy silicone oil, 9.5% plasma fluorinated modified alumina, 6% carbon black, 1.1% palm wax, 1.1% internal release agent, 1.5% vulcanizing agent, 4% triallyl isocyanurate, and 0.7% antioxidant.

[0010] Preferably, the fluorinated modified silicone rubber is prepared from the following raw materials in parts by weight: 3-7 parts of methyl vinyl silicone rubber, 27-63 parts of tetrahydrofuran, 6.6-15.4 parts of C2-18-perfluoroalkyl iodide, 0.024-0.056 parts of photoinitiator, and 48-110 parts of anhydrous ethanol.

[0011] Preferably, the photoinitiator is benzoin dimethyl ether.

[0012] Preferably, the preparation method of the fluorinated modified silicone rubber comprises the following steps:

[0013] Methyl vinyl silicone rubber is added to tetrahydrofuran, stirred with a magnetic stirrer to fully dissolve it, and then C2-18-perfluoroalkyl iodide is added and the mixture is stirred for 30-50 minutes. Then a photoinitiator is added and the mixture is irradiated with a UV lamp in a closed environment for 5-10 minutes. After the reaction is completed, the mixed solution is added to anhydrous ethanol for flocculation to obtain a product, and the product is vacuum dried at 55-65°C to obtain a fluorinated modified silicone rubber.

[0014] Preferably, the hybrid silica is prepared from the following raw materials in parts by weight: 240-360 parts of anhydrous ethanol, 5-8 parts of oleic acid, 22-33 parts of tetraethyl orthosilicate, 5-7.5 parts of silane coupling agent KH560, and 100-150 parts of deionized water.

[0015] Preferably, the preparation method of the hybrid silica comprises the following steps:

[0016] Oleic acid is added to anhydrous ethanol and stirred until completely dissolved; then tetraethyl orthosilicate, silane coupling agent KH560 and deionized water are added, stirred evenly and the pH value of the solution is adjusted to 10-11; then, the mixture is magnetically stirred at a temperature of 60-70°C and a stirring speed of 800-1000 rpm for 6-8 hours; after the reaction, the product is washed and dried to obtain hybrid silica.

[0017] Preferably, the method for preparing the plasma fluorinated modified aluminum oxide comprises the following steps:

[0018] S1. In parts by weight, 150-200 parts of an ethanol aqueous solution are added to 10-15 parts of nano-alumina, stirred until fully dissolved, stirred at a temperature of 50-60 ° C and a stirring speed of 4000-5000 rpm for 20-30 min, 1-1.5 parts of a silane coupling agent KH560 are added, and then 50-75 parts of an ethanol aqueous solution are added, stirring is continued for 40-60 min, and the mixed solution is dried at 80-90 ° C for 48-54h and ground into powder to obtain a silane coupling agent-modified nano-alumina;

[0019] S2. Place the silane coupling agent modified nano-alumina into the reactor and evacuate the reactor to a pressure of 1.8×10 -3 -2.8×10 -3 Pa; then a mixed gas of carbon tetrafluoride and nitrogen is introduced into the kettle until the pressure in the kettle rises to 13-14 kPa; voltage is applied, and plasma fluorination treatment is carried out for 30-40 minutes to obtain plasma fluorinated modified alumina.

[0020] Preferably, the voltage is 22-26 kV.

[0021] This application also provides a method for preparing a polymer sealing ring, which adopts the following technical solution:

[0022] A method for preparing a polymer sealing ring comprises the following steps:

[0023] S1. Weigh the raw materials fluorinated modified silicone rubber, fluororubber, hybrid silica, hydroxy silicone oil, plasma fluorinated modified alumina, carbon black, palm wax, internal release agent, vulcanizing agent, triallyl isocyanurate, and antioxidant according to mass percentage; add the raw materials to a mixer and mix at a temperature of 40-50 ° C for 5-8 min to obtain a rubber compound;

[0024] S2. The rubber compound is added to an injection molding machine and injection molded to obtain a silicone rubber sealing ring precursor;

[0025] S3. Place the silicone rubber sealing ring precursor into a vulcanizer and vulcanize it at a temperature of 165-175°C and a pressure of 15-17 MPa for 25-35 minutes. Then, place it in an oven and perform a secondary vulcanization treatment at a temperature of 180-220°C for 3-4 hours to obtain a silicone rubber sealing ring.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. By adopting the above technical solution, the present application prepares fluorinated modified silicone rubber by grafting C2-18-perfluoroalkyl iodide ethane onto the side chain of silicone rubber, thereby effectively improving the low-temperature resistance of silicone rubber and successfully suppressing the low-temperature crystallization phenomenon of methyl vinyl silicone rubber; in addition, fluororubber has stable performance at high temperatures. The modified silicone rubber provided by the present application also solves the problem of poor compatibility of traditional fluorine / silicone blends. By blending fluorinated modified silicone rubber with fluororubber as the base material of the sealing ring, the obtained sealing ring material has good performance at both high and low temperatures, greatly improving the operating temperature range of the polymer sealing ring.

[0028] 2. This application adopts a one-pot method to jointly treat the in-situ generated silica with a silane coupling agent and oleic acid to prepare hybrid silica. The presence of the silane coupling agent enhances the compatibility between silica and rubber molecular chains. The coating modification with oleic acid can form a film on the surface of silica particles, which helps to reduce the agglomeration between silica particles and significantly improves the dispersibility and compatibility of silica in silicone rubber materials, thereby enhancing the reinforcing effect of silica on rubber materials.

[0029] 3. This application uses a silane coupling agent to couple and modify nano-alumina, and then fluorinates the surface of the silane coupling agent-modified alumina through plasma fluorination treatment to achieve fluorination modification of alumina, which significantly improves the dispersibility and compatibility of nano-alumina in silicone rubber materials, effectively accelerates the vulcanization reaction, increases the cross-linking density, and improves the hardness and wear resistance of the sealing ring material. DETAILED DESCRIPTION

[0030] The present application is further described in detail below with reference to the embodiments.

[0031] The chemical reagents used in the preparation examples, embodiments and comparative examples provided by the present invention are all commercially available products, and their brands and manufacturers are as follows:

[0032] Methyl vinyl silicone rubber, Kangdisi Chemical (Hubei) Co., Ltd.;

[0033] C2-18-Perfluoroalkyl iodide, Xiaogan Shenyuan Chemical Co., Ltd.;

[0034] Fluororubber, Guangdong Wengjiang Chemical Reagent Co., Ltd., FKM246;

[0035] Hydroxy silicone oil, Hubei Zhonglong Kangsheng Fine Chemical Co., Ltd.;

[0036] Carbon black, Tianjin Yiborui Chemical Co., Ltd., carbon black N990;

[0037] Palm wax, Wuhan Hongde Yuexin Pharmaceutical Technology Co., Ltd.;

[0038] WS-280, Dongguan Yuebang Rubber Technology Co., Ltd.

[0039] Preparation Example 1 Preparation of fluorinated modified silicone rubber

[0040] Preparation Example 1.1

[0041] 3 g of methyl vinyl silicone rubber was added to 27 g of tetrahydrofuran, and after magnetic stirring to fully dissolve it, 6.6 g of C2-18-perfluoroalkyl iodide was added and the mixture was continued to be stirred for 30 minutes. Then, 0.024 g of benzoin dimethyl ether was added and irradiated with a 365 nm wavelength ultraviolet lamp in a closed environment to induce the grafting reaction for 5 minutes. After the reaction, the mixed solution was added to 48 g of anhydrous ethanol for flocculation to obtain a product, which was then vacuum dried at 55°C to obtain a fluorinated modified silicone rubber.

[0042] Preparation Example 1.2

[0043] 5 g of methyl vinyl silicone rubber was added to 45 g of tetrahydrofuran, and after magnetic stirring to fully dissolve it, 11 g of C2-18-perfluoroalkyl iodide was added and the mixture was continued to be stirred for 40 minutes. Then, 0.04 g of benzoin dimethyl ether was added and irradiated with a 365 nm wavelength ultraviolet lamp in a closed environment to induce the grafting reaction for 8 minutes. After the reaction, the mixed solution was added to 79 g of anhydrous ethanol for flocculation to obtain a product, which was then vacuum dried at 60°C to obtain a fluorinated modified silicone rubber.

[0044] Preparation Example 1.3

[0045] 7 g of methyl vinyl silicone rubber was added to 63 g of tetrahydrofuran, and after magnetic stirring to fully dissolve it, 15.4 g of C2-18-perfluoroalkyl iodide was added and the mixture was continued to be stirred for 50 minutes. Then, 0.056 g of benzoin dimethyl ether was added and irradiated with a 365 nm wavelength ultraviolet lamp in a closed environment to induce the grafting reaction for 10 minutes. After the reaction, the mixed solution was added to 110 g of anhydrous ethanol for flocculation to obtain a product, which was then vacuum dried at 65°C to obtain a fluorinated modified silicone rubber.

[0046] Preparation Example 2 Preparation of hybrid silica

[0047] Preparation Example 2.1

[0048] 5 g of oleic acid was added to 240 g of anhydrous ethanol and stirred until completely dissolved; then 22 g of tetraethyl orthosilicate, 5 g of silane coupling agent KH560 and 100 g of deionized water were added, stirred evenly, and the pH value of the solution was adjusted to 10 with ammonia water; then the reaction was carried out under magnetic stirring at a temperature of 60° C. and a stirring speed of 800 rpm for 6 hours; after the reaction, the product was washed and dried to obtain hybrid silica.

[0049] Preparation Example 2.2

[0050] 6.5 g of oleic acid was added to 300 g of anhydrous ethanol and stirred until completely dissolved; then 27.5 g of tetraethyl orthosilicate, 6.3 g of silane coupling agent KH560 and 125 g of deionized water were added, stirred evenly, and the pH value of the solution was adjusted to 10.5 using ammonia water; then the reaction was carried out under magnetic stirring at a temperature of 65° C. and a stirring speed of 900 rpm for 7 hours; after the reaction, the product was washed and dried to obtain hybrid silica.

[0051] Preparation Example 2.3

[0052] 8 g of oleic acid was added to 360 g of anhydrous ethanol and stirred until completely dissolved; then 33 g of tetraethyl orthosilicate, 7.5 g of silane coupling agent KH560 and 150 g of deionized water were added, stirred evenly, and the pH value of the solution was adjusted to 11 using ammonia water; then the reaction was carried out under magnetic stirring at a temperature of 70° C. and a stirring speed of 1000 rpm for 8 hours; after the reaction, the product was washed and dried to obtain hybrid silica.

[0053] Preparation Example 3 Plasma Fluorination Modified Alumina

[0054] Preparation Example 3.1

[0055] S1. Add 150g of ethanol-water solution (the mass ratio of ethanol to water is 6:1) to 10g of nano-alumina and stir until fully dissolved. After stirring at 50°C and 4000rpm for 20min, add 1g of silane coupling agent KH560, and then add 50g of ethanol-water solution (the mass ratio of ethanol to water is 6:1). After stirring for 40min, the mixed solution is dried at 80°C for 48h and ground into powder to obtain silane coupling agent-modified nano-alumina.

[0056] S2. Place the silane coupling agent modified nano-alumina into the reactor and evacuate the reactor to a pressure of 2.8×10 - 3 Pa; then, a mixed gas of carbon tetrafluoride and nitrogen (the volume ratio of carbon tetrafluoride to nitrogen is 4:1) is introduced into the kettle until the pressure in the kettle rises to 14 kPa; a voltage of 22 kV is applied, and plasma fluorination treatment is performed for 30 minutes to obtain plasma fluorinated modified alumina.

[0057] Preparation Example 3.2

[0058] S1. 175 g of an ethanol-water solution (the mass ratio of ethanol to water is 8:1) was added to 12.5 g of nano-alumina and stirred until fully dissolved. After stirring at 55°C and 4500 rpm for 25 min, 1.25 g of a silane coupling agent KH560 was added, followed by 62.5 g of an ethanol-water solution (the mass ratio of ethanol to water is 8:1). After further stirring for 50 min, the mixed solution was dried at 85°C for 51 h and ground into powder to obtain silane coupling agent-modified nano-alumina.

[0059] S2. Place the silane coupling agent modified nano-alumina into the reactor and evacuate the reactor to a pressure of 2.3×10 - 3 Pa; then, a mixed gas of carbon tetrafluoride and nitrogen (the volume ratio of carbon tetrafluoride to nitrogen is 4:1) is introduced into the kettle until the pressure in the kettle rises to 13.5 kPa; a voltage of 24 kV is applied, and plasma fluorination treatment is performed for 35 minutes to obtain plasma fluorinated modified alumina.

[0060] Preparation Example 3.3

[0061] S1. 200 g of ethanol-water solution (the mass ratio of ethanol to water is 9:1) was added to 15 g of nano-alumina and stirred until fully dissolved. After stirring at 60°C and 5000 rpm for 30 min, 1.5 g of silane coupling agent KH560 was added, followed by 75 g of ethanol-water solution (the mass ratio of ethanol to water is 9:1). After further stirring for 60 min, the mixed solution was dried at 90°C for 54 h and ground into powder to obtain silane coupling agent-modified nano-alumina.

[0062] S2. Place the silane coupling agent modified nano-alumina into the reactor and evacuate the reactor to a pressure of 1.8×10 - 3 Pa; then, a mixed gas of carbon tetrafluoride and nitrogen (the volume ratio of carbon tetrafluoride to nitrogen is 4:1) is introduced into the kettle until the pressure in the kettle rises to 13 kPa; a voltage of 26 kV is applied, and plasma fluorination treatment is performed for 40 minutes to obtain plasma fluorinated modified alumina.

[0063] Example 1

[0064] S1. Based on 100 g of the raw materials, 30 g of the fluorinated modified silicone rubber prepared in Preparation Example 1.1, 25 g of fluororubber, 16.4 g of hybrid silica prepared in Preparation Example 2.1, 6 g of hydroxy silicone oil, 8 g of plasma fluorinated modified alumina prepared in Preparation Example 3.1, 8 g of carbon black, 0.8 g of palm wax, 0.8 g of internal release agent, 1 g of vulcanizing agent, 3 g of triallyl isocyanurate, and 1 g of antioxidant were weighed; the raw materials were added to a mixer and mixed at 40 ° C for 8 min to obtain a rubber compound;

[0065] S2. The rubber compound is added to an injection molding machine, and the barrel temperature of the injection molding machine is 200°C and the nozzle temperature is 190°C to obtain a polymer rubber seal ring precursor by injection molding;

[0066] S3. The silicone rubber sealing ring precursor was placed in a flat-plate vulcanizer and vulcanized at a temperature of 165°C and a pressure of 15 MPa for 25 min; then placed in an oven and subjected to a secondary vulcanization treatment at a temperature of 180°C for 3 h to obtain a polymer rubber sealing ring;

[0067] The internal release agent used in this embodiment is WS-280; the vulcanizing agent used is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane; the antioxidant used is composed of antioxidant BHT, ultraviolet absorber UV-531, and antioxidant DTPD in a mass ratio of 1:1:3.

[0068] Example 2

[0069] S1. Based on 100 g of the raw materials, 40 g of the fluorinated modified silicone rubber prepared in Preparation Example 1.1, 20 g of fluororubber, 11.9 g of the hybrid silica prepared in Preparation Example 2.1, 4.2 g of hydroxy silicone oil, 9.5 g of plasma fluorinated modified alumina prepared in Preparation Example 3.1, 6 g of carbon black, 1.1 g of palm wax, 1.1 g of internal release agent, 1.5 g of vulcanizing agent, 4 g of triallyl isocyanurate, and 0.7 g of antioxidant were weighed; the raw materials were added to a mixer and mixed at 40 ° C for 8 min to obtain a rubber compound;

[0070] S2. The rubber compound is added to an injection molding machine, and the barrel temperature of the injection molding machine is 200°C and the nozzle temperature is 190°C to obtain a polymer rubber seal ring precursor by injection molding;

[0071] S3. The silicone rubber sealing ring precursor was placed in a flat-plate vulcanizer and vulcanized at a temperature of 165°C and a pressure of 15 MPa for 25 min; then placed in an oven and subjected to a secondary vulcanization treatment at a temperature of 180°C for 3 h to obtain a polymer rubber sealing ring;

[0072] The internal release agent used in this embodiment is WS-280; the vulcanizing agent used is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane; the antioxidant used is composed of antioxidant BHT, ultraviolet absorber UV-531, and antioxidant DTPD in a mass ratio of 1:1:3.

[0073] Example 3

[0074] S1. Based on 100 g of the raw materials, 50 g of the fluorinated modified silicone rubber prepared in Preparation Example 1.1, 15 g of fluororubber, 7.2 g of hybrid silica prepared in Preparation Example 2.1, 2.5 g of hydroxy silicone oil, 11 g of plasma fluorinated modified alumina prepared in Preparation Example 3.1, 4 g of carbon black, 1.4 g of palm wax, 1.4 g of internal release agent, 2 g of vulcanizing agent, 5 g of triallyl isocyanurate, and 0.5 g of antioxidant were weighed; the raw materials were added to a mixer and mixed at 40 ° C for 8 min to obtain a rubber compound;

[0075] S2. The rubber compound is added to an injection molding machine, and the barrel temperature of the injection molding machine is 200°C and the nozzle temperature is 190°C to obtain a polymer rubber seal ring precursor by injection molding;

[0076] S3. The silicone rubber sealing ring precursor was placed in a flat-plate vulcanizer and vulcanized at a temperature of 165°C and a pressure of 15 MPa for 25 min; then placed in an oven and subjected to a secondary vulcanization treatment at a temperature of 180°C for 3 h to obtain a polymer rubber sealing ring;

[0077] The internal release agent used in this embodiment is WS-280; the vulcanizing agent used is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane; the antioxidant used is composed of antioxidant BHT, ultraviolet absorber UV-531, and antioxidant DTPD in a mass ratio of 1:1:3.

[0078] Example 4

[0079] S1. Based on 100 g of the raw materials, 30 g of the fluorinated modified silicone rubber prepared in Preparation Example 1.1, 25 g of fluororubber, 16.4 g of hybrid silica prepared in Preparation Example 2.1, 6 g of hydroxy silicone oil, 8 g of plasma fluorinated modified alumina prepared in Preparation Example 3.1, 8 g of carbon black, 0.8 g of palm wax, 0.8 g of internal release agent, 1 g of vulcanizing agent, 3 g of triallyl isocyanurate, and 1 g of antioxidant were weighed; the raw materials were added to a mixer and mixed at 45 ° C for 7 min to obtain a rubber compound;

[0080] S2. The rubber compound is added to an injection molding machine, and the barrel temperature of the injection molding machine is 210°C and the nozzle temperature is 200°C, and injection molding is performed to obtain a polymer rubber seal ring precursor;

[0081] S3. The silicone rubber sealing ring precursor was placed in a flat-plate vulcanizer and vulcanized at a temperature of 170°C and a pressure of 16 MPa for 30 min; then placed in an oven and subjected to a secondary vulcanization treatment at a temperature of 200°C for 3.5 h to obtain a polymer rubber sealing ring;

[0082] The internal release agent used in this embodiment is WS-280; the vulcanizing agent used is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane; the antioxidant used is composed of antioxidant BHT, ultraviolet absorber UV-531, and antioxidant DTPD in a mass ratio of 1:1:3.

[0083] Example 5

[0084] S1. Based on 100 g of the raw materials, 30 g of the fluorinated modified silicone rubber prepared in Preparation Example 1.1, 25 g of fluororubber, 16.4 g of hybrid silica prepared in Preparation Example 2.1, 6 g of hydroxy silicone oil, 8 g of plasma fluorinated modified alumina prepared in Preparation Example 3.1, 8 g of carbon black, 0.8 g of palm wax, 0.8 g of internal release agent, 1 g of vulcanizing agent, 3 g of triallyl isocyanurate, and 1 g of antioxidant were weighed; the raw materials were added to a mixer and mixed at 50 ° C for 5 min to obtain a rubber compound;

[0085] S2. The rubber compound is added to an injection molding machine, and the barrel temperature of the injection molding machine is 220°C and the nozzle temperature is 230°C, and injection molding is performed to obtain a polymer rubber seal ring precursor;

[0086] S3. The silicone rubber sealing ring precursor was placed in a flat-plate vulcanizer and vulcanized at a temperature of 175°C and a pressure of 17 MPa for 35 minutes; then placed in an oven and subjected to a secondary vulcanization treatment at a temperature of 220°C for 4 hours to obtain a polymer rubber sealing ring;

[0087] The internal release agent used in this embodiment is WS-280; the vulcanizing agent used is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane; the antioxidant used is composed of antioxidant BHT, ultraviolet absorber UV-531, and antioxidant DTPD in a mass ratio of 1:1:3.

[0088] Example 6

[0089] The difference between Example 6 and Example 1 is that the fluorinated modified silicone rubber used in Example 6 is prepared by Preparation Example 1.2.

[0090] Example 7

[0091] The difference between Example 7 and Example 1 is that the fluorinated modified silicone rubber used in Example 7 is prepared by Preparation Example 1.3.

[0092] Example 8

[0093] The difference between Example 8 and Example 1 is that the hybrid silica used in Example 8 is prepared by Preparation Example 2.2.

[0094] Example 9

[0095] The difference between Example 9 and Example 1 is that the hybrid silica used in Example 9 is prepared by Preparation Example 2.3.

[0096] Example 10

[0097] The difference between Example 10 and Example 1 is that the plasma fluorination-modified alumina used in Example 10 is prepared by Preparation Example 3.2.

[0098] Example 11

[0099] The difference between Example 11 and Example 1 is that the plasma fluorination-modified alumina used in Example 11 is prepared by Preparation Example 3.3.

[0100] Comparative Example 1

[0101] The difference between Comparative Example 1 and Example 1 is that the silicone rubber used in Comparative Example 1 is methyl vinyl silicone rubber that has not been fluorinated.

[0102] Comparative Example 2

[0103] The difference between Comparative Example 2 and Example 1 is that the white carbon black used in Comparative Example 2 is commercially available fumed white carbon black purchased from Jiangxi Hongbai New Materials Co., Ltd.

[0104] Comparative Example 3

[0105] The difference between Comparative Example 3 and Example 1 is that the aluminum oxide used in Comparative Example 3 is not a nano-aluminum oxide modified by plasma fluorination.

[0106] Comparative Example 4

[0107] The difference between Comparative Example 4 and Example 1 is that no fluororubber is added in Comparative Example 4, and an equal amount of fluorinated modified silicone rubber is used instead.

[0108] Performance testing

[0109] 1. The tensile strength and elongation at break of the polymer sealing rings obtained in Examples 1-11 and Comparative Examples 1-4 were tested with reference to ASTM-D3574-08. The results are shown in Table 1.

[0110] 2. Weathering resistance test: Referring to GB / T 3511-2018, the polymer sealing rings obtained in Examples 1-11 and Comparative Examples 1-4 were irradiated for 168 hours, and the tensile strength retention percentage was measured and calculated. The results are shown in Table 1.

[0111] 3. High and low temperature alternating environment test: The polymer sealing rings obtained in Examples 1-11 and Comparative Examples 1-4 were placed in an environment of 100°C for 5 hours, and then placed in an environment of -20°C for 5 hours, and the cycle was repeated 100 times. The tensile strength performance retention percentage was tested and calculated. The results are shown in Table 1.

[0112] The specific test results are as follows:

[0113] It can be seen from the test results in Table 1 that the polymer sealing ring provided by the present application has strong tensile strength and elongation at break, and after 168 hours of irradiation, the performance retention rate of the tensile strength can reach more than 98%, indicating that the polymer sealing ring provided by the present application has excellent weather resistance; in addition, after the polymer sealing ring provided by the present application is subjected to a cyclic alternating placement test in an environment of 100°C and -20°C, the performance retention rate of its tensile strength can reach more than 98%, indicating that the polymer sealing ring provided by the present application has excellent temperature change resistance and has a wide range of applications.

[0114] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A polymer sealing ring, characterized by: The raw materials include, by mass percentage, 30-50% of fluorinated modified silicone rubber, 15-25% of fluororubber, 7.2-16.4% of hybrid silica, 2.5-6% of hydroxy silicone oil, 8-11% of plasma fluorinated modified alumina, 4-8% of carbon black, 0.8-1.4% of palm wax, 0.8-1.4% of internal release agent, 1-2% of vulcanizing agent, 3-5% of triallyl isocyanurate, and 0.5-1% of antioxidant.

2. The polymer sealing ring according to claim 1, characterized in that: The raw materials include, by mass percentage, 40% of fluorinated modified silicone rubber, 20% of fluororubber, 11.9% of hybrid silica, 4.2% of hydroxy silicone oil, 9.5% of plasma fluorinated modified alumina, 6% of carbon black, 1.1% of palm wax, 1.1% of internal mold release agent, 1.5% of vulcanizing agent, 4% of triallyl isocyanurate, and 0.7% of antioxidant.

3. A polymer sealing ring according to claim 1 or 2, characterized in that: The fluorinated modified silicone rubber is prepared from the following raw materials in parts by weight: 3-7 parts of methyl vinyl silicone rubber, 27-63 parts of tetrahydrofuran, 6.6-15.4 parts of C2-18-perfluoroalkyl iodide ethane, 0.024-0.056 parts of photoinitiator, and 48-110 parts of anhydrous ethanol.

4. The polymer sealing ring according to claim 3, characterized in that: The photoinitiator is benzoin dimethyl ether.

5. The polymer sealing ring according to claim 3, characterized in that: The preparation method of the fluorinated modified silicone rubber comprises the following steps: Methyl vinyl silicone rubber is added to tetrahydrofuran, magnetically stirred to fully dissolve it, and then C2-18-perfluoroalkyl iodide is added and the mixing and stirring is continued for 30-50 minutes. Then, a photoinitiator is added and the mixture is irradiated with a UV lamp in a closed environment for 5-10 minutes. After the reaction is completed, the mixed solution is added to anhydrous ethanol for flocculation to obtain a product, and the product is vacuum dried at 55-65°C to obtain a fluorinated modified silicone rubber.

6. A polymer sealing ring according to claim 1 or 2, characterized in that: The hybrid white carbon black is prepared from the following raw materials in parts by weight: 240-360 parts of anhydrous ethanol, 5-8 parts of oleic acid, 22-33 parts of tetraethyl orthosilicate, 5-7.5 parts of silane coupling agent KH560, and 100-150 parts of deionized water.

7. The polymer sealing ring according to claim 6, characterized in that: The preparation method of the hybrid silica comprises the following steps: Oleic acid is added to anhydrous ethanol and stirred until completely dissolved; then tetraethyl orthosilicate, silane coupling agent KH560 and deionized water are added, stirred evenly and the pH value of the solution is adjusted to 10-11; then, the mixture is magnetically stirred at a temperature of 60-70°C and a stirring speed of 800-1000 rpm for 6-8 hours; after the reaction, the product is washed and dried to obtain hybrid silica.

8. A polymer sealing ring according to claim 1 or 2, characterized in that: The preparation method of the plasma fluorinated modified aluminum oxide comprises the following steps: S1. In parts by weight, 150-200 parts of an ethanol aqueous solution are added to 10-15 parts of nano-alumina, stirred until fully dissolved, stirred at a temperature of 50-60 ° C and a stirring speed of 4000-5000 rpm for 20-30 min, 1-1.5 parts of a silane coupling agent KH560 are added, and then 50-75 parts of an ethanol aqueous solution are added, stirring is continued for 40-60 min, and the mixed solution is dried at 80-90 ° C for 48-54h and ground into powder to obtain a silane coupling agent-modified nano-alumina; S2. Place the silane coupling agent modified nano-alumina into the reactor and evacuate the reactor to a pressure of 1.8×10 -3 -2.8×10 -3 Pa; then a mixed gas of carbon tetrafluoride and nitrogen is introduced into the kettle until the pressure in the kettle rises to 13-14 kPa; voltage is applied, and plasma fluorination treatment is carried out for 30-40 minutes to obtain plasma fluorinated modified alumina.

9. The polymer sealing ring according to claim 8, characterized in that: The voltage is 22-26 kV.

10. A method for preparing a polymer sealing ring according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Weigh the raw materials fluorinated modified silicone rubber, fluororubber, hybrid silica, hydroxy silicone oil, plasma fluorinated modified alumina, carbon black, palm wax, internal release agent, vulcanizing agent, triallyl isocyanurate, and antioxidant according to mass percentage; add the raw materials to a mixer and mix at a temperature of 40-50 ° C for 5-8 min to obtain a rubber compound; S2. The rubber compound is added to an injection molding machine and injection molded to obtain a polymer rubber seal ring precursor; S3. Place the silicone rubber sealing ring precursor into a vulcanizer and vulcanize it at a temperature of 165-175°C and a pressure of 15-17 MPa for 25-35 minutes. Then, place it in an oven and perform a secondary vulcanization treatment at a temperature of 180-220°C for 3-4 hours to obtain a polymer rubber sealing ring.

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