Anti-aging sealing rubber material and preparation process thereof

Abstract

The invention relates to the technical field of sealing rubber, and particularly discloses an anti-aging sealing rubber material and a preparation process thereof, and anti-aging modified styrene-butadiene rubber, butadiene rubber, white carbon black, zinc oxide, stearic acid, load accelerator lignin and other rubber additives are mixed into the anti-aging sealing rubber material in a mixing and vulcanizing manner. The prepared aging-resistant sealing rubber material has good tensile strength and elongation at break, also has excellent aging resistance, and can solve the problem that the aging resistance of the sealing rubber material is not good enough.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing rubbers, in particular to an aging-resistant sealing rubber material and a preparation process thereof. Background Art

[0002] Sealing is a measure implemented at the joints of machinery, equipment, or pipelines to prevent air and water leaks, which could lead to the intrusion of external media into the interior or the intrusion of internal media into the external environment and contaminate the environment. Incomplete sealing of equipment can result in excessive energy or material losses during production, causing economic losses or environmental pollution. Sealing materials, which achieve this sealing function, are widely used in industries such as machinery manufacturing, petrochemicals, transportation, and precision manufacturing.

[0003] Rubber sealing materials are primarily rubber-based sealing materials that exhibit excellent flexibility, elasticity, density, and wear resistance. They also have a wide applicable temperature range and are easy to install, making them suitable for sealing a wide range of equipment. Therefore, rubber sealing materials have become the mainstream sealing material among non-metallic sealing materials. However, in actual applications, rubber sealing materials are often affected by environmental factors such as temperature, corrosion, vibration, and stress, and inevitably age. This leads to changes in the physical and chemical properties of the rubber sealing structure and a decrease in sealing characteristics, manifested specifically in hardening, brittleness, loosening, and even cracking of the rubber sealing material. Rubber aging is an irreversible process. After aging, the performance of the rubber material deteriorates and the rubber material loses its usability. Therefore, developing a sealing rubber material that can slow or inhibit the aging process of rubber is of great significance to the development of rubber sealing materials. Summary of the Invention

[0004] The purpose of the present invention is to provide an aging-resistant sealing rubber material and a preparation process thereof, so as to solve the problem that the aging-resistant performance of the sealing rubber material is not good enough.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A preparation process of an aging-resistant sealing rubber material, specifically comprising: The anti-aging modified rubber, butadiene rubber, zinc oxide, stearic acid, white carbon black, aromatic oil, sulfur and lignin as a loading accelerator are mixed evenly, cooled, sheeted and vulcanized to obtain an anti-aging sealing rubber material.

[0006] As a limitation of the present invention, in the aging-resistant sealing rubber material, the amount of each component is, by mass, 75 to 85 parts of anti-aging modified styrene-butadiene rubber, 75 to 85 parts of butadiene rubber, 75 to 85 parts of zinc oxide, 75 to 85 parts of stearic acid, 75 to 85 parts of white carbon black, 75 to 85 parts of aromatic oil, 75 to 85 parts of sulfur, and 75 to 85 parts of loaded promoter lignin.

[0007] As a limitation of the present invention, the preparation method of the anti-aging modified styrene-butadiene rubber is: Dissolving styrene butadiene rubber in cyclohexane to prepare a styrene butadiene rubber solution, dissolving meta-chloroperbenzoic acid in tetrahydrofuran to prepare a meta-chloroperbenzoic acid solution, heating the styrene butadiene rubber solution to 30-40° C., slowly adding the meta-chloroperbenzoic acid solution while stirring continuously, reacting for 0.5-1 hour, adjusting the pH to 7-8 with a sodium hydroxide solution after the reaction is completed, and then flocculating, precipitating, and drying in anhydrous ethanol to obtain epoxidized styrene butadiene rubber; The epoxidized styrene butadiene rubber is dissolved in tetrahydrofuran to prepare an epoxidized styrene butadiene rubber solution, hydrochloric acid is slowly added to the epoxidized styrene butadiene rubber solution, and the mixture is reacted at 30 to 40° C. for 1 to 3 hours. After the reaction is completed, the mixture is flocculated, precipitated, and dried in anhydrous ethanol to obtain a hydroxylated styrene butadiene rubber. Hydroxylated styrene butadiene rubber is dissolved in dichloromethane to prepare hydroxylated styrene butadiene rubber solution, 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid and 4-pyrrolidinopyridine are added to the hydroxylated styrene butadiene rubber solution, and after stirring and activating for 0.5 to 1 hour, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is added, and the mixture is stirred and reacted at room temperature for 20 to 26 hours under nitrogen as a protective gas. After the reaction is completed, the mixture is flocculated, precipitated and dried in anhydrous ethanol to obtain anti-aging modified styrene butadiene rubber.

[0008] As a limitation of the present invention, the mass fraction of butylbenzene in the butylbenzene rubber solution is 5-15%, the mass fraction of chloroperbenzoic acid in the meta-chloroperbenzoic acid solution is 30-40%, and the mass ratio of butylbenzene to meta-chloroperbenzoic acid is (95-105): (33-37).

[0009] As a limitation of the present invention, the mass fraction of epoxidized styrene butadiene in the epoxidized styrene butadiene glue is 5-15%, and the mass ratio of epoxidized styrene butadiene to hydrochloric acid is (95-105): (10-12).

[0010] As a limitation of the present invention, the amount of each component in the anti-aging modified styrene-butadiene rubber is, by mass, 95 to 105 parts of hydroxylated styrene-butadiene, 19 to 20 parts of 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid, 4 to 5 parts of 4-pyrrolidinopyridine, and 16 to 17 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride.

[0011] As a limitation of the present invention, the preparation method of the loaded accelerator lignin is: Adding lignin and silane coupling agent KH-560 to a mixed solution of anhydrous ethanol and deionized water, stirring evenly, stirring and reacting at 50-70° C. and 1400-1600 rpm for 1.5-2.5 hours, cooling after the reaction is completed, filtering, washing with anhydrous ethanol and deionized water, and drying to obtain silane coupling agent-modified lignin; N-cyclohexyl-2-benzothiazolesulfenamide is added to a mixed solution of anhydrous ethanol and deionized water, and after stirring evenly, a silane coupling agent is added to modify the lignin. The mixture is stirred at 60-80° C. for 3-5 hours. After the reaction is completed, the mixture is cooled, filtered, washed with anhydrous ethanol, and dried to obtain the promoter-loaded lignin.

[0012] As a limitation of the present invention, the mass ratio of the lignin, the silane coupling agent KH-560, and N-cyclohexyl-2-benzothiazole sulfenamide is (5-15): (3-7): (0.3-0.7).

[0013] As a limitation of the present invention, the specific steps of mixing and vulcanizing to prepare the aging-resistant sealing rubber material are: Anti-aging modified styrene-butadiene rubber and butadiene rubber are added to an internal mixer, the mixing temperature is set to 50-70°C, the speed is set to 20-30 rpm, after mixing for 1-3 minutes, zinc oxide and stearic acid are added in sequence, the speed is increased to 30-40 rpm, after mixing for 5-10 minutes, white carbon black and aromatic oil are added, the temperature is raised to 140-160°C, the speed is increased to 40-50 rpm, the mixing is continued for 1-3 minutes, the rubber is discharged, and the rubber is cooled to room temperature; the cooled discharged rubber is placed in an open mixer and continued to be mixed, and sulfur and a load accelerator lignin are added after the rubber is rolled. The rubber is cut left and right 3-7 times and triangularly packaged and rolled 3-7 times. After mixing evenly, the rubber is cooled and discharged, and the rubber is vulcanized at 130-150°C for 30-50 minutes using a flat vulcanizer to obtain an aging-resistant sealing rubber material.

[0014] Compared with the prior art, the present invention has the following beneficial effects: SBR was modified by epoxidation, hydroxylation, and grafting with the phenolic antioxidant 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid to produce a styrene-butadiene rubber containing epoxy groups, hydroxyl groups, and a phenolic antioxidant on the molecular chain. This significantly improved the rubber's resistance to thermal oxidative aging, effectively reduced the migration of the antioxidant within the rubber, and simultaneously enhanced the rubber's mechanical properties, increasing its tensile strength and elongation at break.

[0015] The rubber accelerator N-cyclohexyl-2-benzothiazole sulfenamide has the effects of preventing scorch and promoting vulcanization in the preparation process of rubber materials. However, as the amount of accelerator increases, the mechanical properties of the rubber material, such as tensile strength and elongation at break, also decrease. The accelerator N-cyclohexyl-2-benzothiazole sulfenamide is reacted with lignin modified with a silane coupling agent so that it is loaded on the lignin. This not only reduces the amount of accelerator in the rubber material, but also improves the mechanical properties of the rubber material to a certain extent. In addition, the presence of sterically hindered phenol groups in the lignin structure can capture free radicals generated by aging of the rubber molecular chain, blocking the chain transfer reaction, thereby improving the anti-oxidative aging performance of the rubber material. DETAILED DESCRIPTION

[0016] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0017] Styrene butadiene rubber (latex polystyrene butadiene rubber 1502, content 25%), butadiene rubber (1,4-vinyl, Mw 200000), lignin (alkaline lignin, pH 8.0-10.1), white carbon black (200nm), aromatic oil (1.02g / cm 3 , 24mm 2 / s).

[0018] Example 1: A process for preparing an aging-resistant sealing rubber material, specifically comprising: Step 1: Preparation of epoxidized styrene butadiene rubber 100 g of styrene butadiene rubber 1502 was dissolved in cyclohexane to prepare a styrene butadiene rubber solution with a mass fraction of 10%. 34.5 g of m-chloroperbenzoic acid was dissolved in tetrahydrofuran to prepare a m-chloroperbenzoic acid solution with a mass fraction of 35%. After the styrene butadiene rubber solution was heated to 35°C, the m-chloroperbenzoic acid solution was slowly added with continuous stirring and the reaction was carried out for 1 hour. After the reaction was completed, the pH was adjusted to 8 with sodium hydroxide solution, and then the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain epoxidized styrene butadiene rubber.

[0019] Step 2: Preparation of hydroxylated styrene butadiene rubber 100 g of epoxidized styrene butadiene rubber was dissolved in tetrahydrofuran to prepare a 10% by mass epoxidized styrene butadiene rubber solution. 10.9 g of a 36.5% by mass hydrochloric acid solution was slowly added to the epoxidized styrene butadiene rubber solution and reacted at 35°C for 2 h. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain hydroxylated styrene butadiene rubber.

[0020] Step 3: Preparation of anti-aging modified styrene-butadiene rubber 100 g of hydroxylated styrene butadiene rubber was dissolved in dichloromethane to prepare a hydroxylated styrene butadiene rubber solution with a mass fraction of 10%. 19.4 g of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 4.3 g of 4-pyrrolidinopyridine were added to the hydroxylated styrene butadiene rubber solution. After stirring and activation for 1 h, 16.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride was added. The mixture was stirred and reacted at room temperature for 24 h under nitrogen as a protective gas. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain anti-aging modified styrene butadiene rubber.

[0021] Step 4: Preparation of accelerator-loaded lignin 10 g of lignin and 5 g of silane coupling agent KH-560 were added to a mixed solution of 240 g of anhydrous ethanol and 60 g of deionized water, stirred evenly, and reacted at 60° C. and 1500 rpm for 2 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol and deionized water, and dried to obtain silane coupling agent-modified lignin; 0.5 g of N-cyclohexyl-2-benzothiazolesulfonamide was added to a mixed solution of 200 g of anhydrous ethanol and 50 g of deionized water, stirred evenly, and then the silane coupling agent-modified lignin was added. The mixture was stirred at 70° C. for 4 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol, and dried to obtain promoter-loaded lignin.

[0022] Step 5: Prepare aging-resistant sealing rubber material 80 parts of anti-aging modified styrene-butadiene rubber and 20 parts of butadiene rubber were added to an internal mixer by mass, the mixing temperature was set to 60°C and the speed was 30 rpm. After mixing for 1.5 minutes, 5 parts of zinc oxide and 2 parts of stearic acid were added in sequence, the speed was increased to 35 rpm, and after mixing for 5 minutes, 45 parts of white carbon black and 5 parts of aromatic oil were added. The temperature was raised to 150°C and the speed was increased to 45 rpm. After continuing to mix for 2 minutes, the rubber was discharged and cooled to room temperature. The cooled discharged rubber was placed in an open mixer and continued to be mixed. After it was rolled, 2 parts of sulfur and 15 parts of a load promoter lignin were added. The left and right cutters were used 6 times and the triangle package and roll package were made 6 times. After mixing evenly, it was cooled and discharged. The sheet was vulcanized at 145°C for 30 minutes using a flat vulcanizer to obtain an aging-resistant sealing rubber material.

[0023] Example 2: A process for preparing an aging-resistant sealing rubber material, specifically comprising: Step 1: Preparation of epoxidized styrene butadiene rubber 100 g of styrene butadiene rubber 1502 was dissolved in cyclohexane to prepare a styrene butadiene rubber solution with a mass fraction of 10%. 34.5 g of m-chloroperbenzoic acid was dissolved in tetrahydrofuran to prepare a m-chloroperbenzoic acid solution with a mass fraction of 35%. After the styrene butadiene rubber solution was heated to 35°C, the m-chloroperbenzoic acid solution was slowly added with continuous stirring and the reaction was carried out for 1 hour. After the reaction was completed, the pH was adjusted to 8 with sodium hydroxide solution, and then the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain epoxidized styrene butadiene rubber.

[0024] Step 2: Preparation of hydroxylated styrene butadiene rubber 100 g of epoxidized styrene butadiene rubber was dissolved in tetrahydrofuran to prepare a 10% by mass epoxidized styrene butadiene rubber solution. 10.9 g of a 36.5% by mass hydrochloric acid solution was slowly added to the epoxidized styrene butadiene rubber solution and reacted at 35°C for 2 h. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain hydroxylated styrene butadiene rubber.

[0025] Step 3: Preparation of anti-aging modified styrene-butadiene rubber 100 g of hydroxylated styrene butadiene rubber was dissolved in dichloromethane to prepare a hydroxylated styrene butadiene rubber solution with a mass fraction of 10%. 19.4 g of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 4.3 g of 4-pyrrolidinopyridine were added to the hydroxylated styrene butadiene rubber solution. After stirring and activation for 1 h, 16.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride was added. The mixture was stirred and reacted at room temperature for 24 h under nitrogen as a protective gas. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain anti-aging modified styrene butadiene rubber.

[0026] Step 4: Preparation of accelerator-loaded lignin 10 g of lignin and 5 g of silane coupling agent KH-560 were added to a mixed solution of 240 g of anhydrous ethanol and 60 g of deionized water, stirred evenly, and reacted at 60° C. and 1500 rpm for 2 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol and deionized water, and dried to obtain silane coupling agent-modified lignin; 0.5 g of N-cyclohexyl-2-benzothiazolesulfonamide was added to a mixed solution of 200 g of anhydrous ethanol and 50 g of deionized water, stirred evenly, and then the silane coupling agent-modified lignin was added. The mixture was stirred at 70° C. for 4 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol, and dried to obtain promoter-loaded lignin.

[0027] Step 5: Prepare aging-resistant sealing rubber material By mass, 85 parts of anti-aging modified styrene-butadiene rubber and 25 parts of butadiene rubber were added to an internal mixer, the mixing temperature was set to 60°C and the speed was 30 rpm. After mixing for 1.5 minutes, 7 parts of zinc oxide and 3 parts of stearic acid were added in sequence, the speed was increased to 35 rpm, and after mixing for 5 minutes, 50 parts of white carbon black and 7 parts of aromatic oil were added. The temperature was raised to 150°C, the speed was increased to 45 rpm, and the mixing was continued for 2 minutes before the rubber was discharged and cooled to room temperature. The cooled discharged rubber was placed in an open mixer and continued to be mixed. After it was rolled, 3 parts of sulfur and 20 parts of load promoter lignin were added. The left and right cutters were used 6 times and the triangle packages and roll packages were made 6 times. After mixing evenly, it was cooled and discharged. The sheet was vulcanized at 145°C for 30 minutes using a flat vulcanizer to obtain an aging-resistant sealing rubber material.

[0028] Example 3: A process for preparing an aging-resistant sealing rubber material, specifically comprising: Step 1: Preparation of epoxidized styrene butadiene rubber 100 g of styrene butadiene rubber 1502 was dissolved in cyclohexane to prepare a styrene butadiene rubber solution with a mass fraction of 10%. 34.5 g of m-chloroperbenzoic acid was dissolved in tetrahydrofuran to prepare a m-chloroperbenzoic acid solution with a mass fraction of 35%. After the styrene butadiene rubber solution was heated to 35°C, the m-chloroperbenzoic acid solution was slowly added with continuous stirring and the reaction was carried out for 1 hour. After the reaction was completed, the pH was adjusted to 8 with sodium hydroxide solution, and then the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain epoxidized styrene butadiene rubber.

[0029] Step 2: Preparation of hydroxylated styrene butadiene rubber 100 g of epoxidized styrene butadiene rubber was dissolved in tetrahydrofuran to prepare a 10% by mass epoxidized styrene butadiene rubber solution. 10.9 g of a 36.5% by mass hydrochloric acid solution was slowly added to the epoxidized styrene butadiene rubber solution and reacted at 35°C for 2 h. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain hydroxylated styrene butadiene rubber.

[0030] Step 3: Preparation of anti-aging modified styrene-butadiene rubber 100 g of hydroxylated styrene butadiene rubber was dissolved in dichloromethane to prepare a hydroxylated styrene butadiene rubber solution with a mass fraction of 10%. 19.4 g of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 4.3 g of 4-pyrrolidinopyridine were added to the hydroxylated styrene butadiene rubber solution. After stirring and activation for 1 h, 16.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride was added. The mixture was stirred and reacted at room temperature for 24 h under nitrogen as a protective gas. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain anti-aging modified styrene butadiene rubber.

[0031] Step 4: Preparation of accelerator-loaded lignin 10 g of lignin and 5 g of silane coupling agent KH-560 were added to a mixed solution of 240 g of anhydrous ethanol and 60 g of deionized water, stirred evenly, and reacted at 60° C. and 1500 rpm for 2 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol and deionized water, and dried to obtain silane coupling agent-modified lignin; 0.5 g of N-cyclohexyl-2-benzothiazolesulfonamide was added to a mixed solution of 200 g of anhydrous ethanol and 50 g of deionized water, stirred evenly, and then the silane coupling agent-modified lignin was added. The mixture was stirred at 70° C. for 4 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol, and dried to obtain promoter-loaded lignin.

[0032] Step 5: Prepare aging-resistant sealing rubber material By mass, 75 parts of anti-aging modified styrene-butadiene rubber and 15 parts of butadiene rubber were added to an internal mixer, the mixing temperature was set to 60°C and the speed was 30 rpm. After mixing for 1.5 minutes, 3 parts of zinc oxide and 1 part of stearic acid were added in sequence, the speed was increased to 35 rpm, and after mixing for 5 minutes, 40 parts of white carbon black and 3 parts of aromatic oil were added. The temperature was raised to 150°C and the speed was increased to 45 rpm. After continuing to mix for 2 minutes, the rubber was discharged and cooled to room temperature. The cooled discharged rubber was placed in an open mixer and continued to be mixed. After it was rolled, 2 parts of sulfur and 10 parts of load promoter lignin were added. The left and right cutters were used 6 times and the triangle packages and roll packages were made 6 times. After mixing evenly, it was cooled and discharged. The sheet was vulcanized at 145°C for 30 minutes using a flat vulcanizer to obtain an aging-resistant sealing rubber material.

[0033] Based on Example 1, control experiments were conducted, specifically Comparative Example 1, Comparative Example 2 and Comparative Example 3, as described below: Comparative Example 1: This comparative example relates to a preparation process of an aging-resistant sealing rubber material. The difference from Example 1 is that hydroxylated styrene-butadiene rubber is used as a raw material. Specifically: Step 1: Preparation of epoxidized styrene butadiene rubber 100 g of styrene butadiene rubber 1502 was dissolved in cyclohexane to prepare a styrene butadiene rubber solution with a mass fraction of 10%. 34.5 g of m-chloroperbenzoic acid was dissolved in tetrahydrofuran to prepare a m-chloroperbenzoic acid solution with a mass fraction of 35%. After the styrene butadiene rubber solution was heated to 35°C, the m-chloroperbenzoic acid solution was slowly added with continuous stirring and the reaction was carried out for 1 hour. After the reaction was completed, the pH was adjusted to 8 with sodium hydroxide solution, and then the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain epoxidized styrene butadiene rubber.

[0034] Step 2: Preparation of hydroxylated styrene butadiene rubber 100 g of epoxidized styrene butadiene rubber was dissolved in tetrahydrofuran to prepare a 10% by mass epoxidized styrene butadiene rubber solution. 10.9 g of a 36.5% by mass hydrochloric acid solution was slowly added to the epoxidized styrene butadiene rubber solution and reacted at 35°C for 2 h. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain hydroxylated styrene butadiene rubber.

[0035] Step 3: Preparation of accelerator-loaded lignin 10 g of lignin and 5 g of silane coupling agent KH-560 were added to a mixed solution of 240 g of anhydrous ethanol and 60 g of deionized water, stirred evenly, and reacted at 60° C. and 1500 rpm for 2 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol and deionized water, and dried to obtain silane coupling agent-modified lignin; 0.5 g of N-cyclohexyl-2-benzothiazolesulfonamide was added to a mixed solution of 200 g of anhydrous ethanol and 50 g of deionized water, stirred evenly, and then the silane coupling agent-modified lignin was added. The mixture was stirred at 70° C. for 4 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol, and dried to obtain promoter-loaded lignin.

[0036] Step 4: Preparation of aging-resistant sealing rubber material 80 parts of hydroxylated styrene butadiene rubber and 20 parts of butadiene rubber were added to an internal mixer by mass, the mixing temperature was set to 60°C and the speed was 30 rpm. After mixing for 1.5 minutes, 5 parts of zinc oxide and 2 parts of stearic acid were added in sequence, the speed was increased to 35 rpm, and after mixing for 5 minutes, 45 parts of white carbon black and 5 parts of aromatic oil were added. The temperature was raised to 150°C and the speed was increased to 45 rpm. After continuing to mix for 2 minutes, the rubber was discharged and cooled to room temperature. The cooled discharged rubber was placed in an open mixer and continued to be mixed. After it was rolled, 2 parts of sulfur and 15 parts of a load promoter lignin were added. The left and right cutters were used 6 times and the triangle packages and roll packages were made 6 times. After mixing evenly, the rubber was cooled and discharged. The rubber was vulcanized at 145°C for 30 minutes using a flat vulcanizer to obtain an aging-resistant sealing rubber material.

[0037] Comparative Example 2: This comparative example relates to a preparation process of an aging-resistant sealing rubber material. The difference from Example 1 is that epoxidized styrene-butadiene rubber is used as a raw material. Specifically: Step 1: Preparation of epoxidized styrene butadiene rubber 100 g of styrene butadiene rubber 1502 was dissolved in cyclohexane to prepare a styrene butadiene rubber solution with a mass fraction of 10%. 34.5 g of m-chloroperbenzoic acid was dissolved in tetrahydrofuran to prepare a m-chloroperbenzoic acid solution with a mass fraction of 35%. After the styrene butadiene rubber solution was heated to 35°C, the m-chloroperbenzoic acid solution was slowly added with continuous stirring and the reaction was carried out for 1 hour. After the reaction was completed, the pH was adjusted to 8 with sodium hydroxide solution, and then the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain epoxidized styrene butadiene rubber.

[0038] Step 2: Preparation of accelerator-loaded lignin 10 g of lignin and 5 g of silane coupling agent KH-560 were added to a mixed solution of 240 g of anhydrous ethanol and 60 g of deionized water, stirred evenly, and reacted at 60° C. and 1500 rpm for 2 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol and deionized water, and dried to obtain silane coupling agent-modified lignin; 0.5 g of N-cyclohexyl-2-benzothiazolesulfonamide was added to a mixed solution of 200 g of anhydrous ethanol and 50 g of deionized water, stirred evenly, and then the silane coupling agent-modified lignin was added. The mixture was stirred at 70° C. for 4 h. After the reaction was completed, the mixture was cooled, filtered, washed with anhydrous ethanol, and dried to obtain promoter-loaded lignin.

[0039] Step 3: Preparation of aging-resistant sealing rubber material 80 parts of epoxidized styrene butadiene rubber and 20 parts of butadiene rubber were added to an internal mixer by mass, the mixing temperature was set to 60°C and the speed was 30 rpm. After mixing for 1.5 minutes, 5 parts of zinc oxide and 2 parts of stearic acid were added in sequence, the speed was increased to 35 rpm, and after mixing for 5 minutes, 45 parts of white carbon black and 5 parts of aromatic oil were added. The temperature was raised to 150°C and the speed was increased to 45 rpm. After continuing to mix for 2 minutes, the rubber was discharged and cooled to room temperature. The cooled discharged rubber was placed in an open mixer and continued to be mixed. After it was rolled, 2 parts of sulfur and 15 parts of a load promoter lignin were added. The left and right cutters were used 6 times and the triangle package and roll package were made 6 times. After mixing evenly, it was cooled and discharged. The sheet was vulcanized at 145°C for 30 minutes using a flat vulcanizer to obtain an aging-resistant sealing rubber material.

[0040] Comparative Example 3: This comparative example relates to a preparation process of an aging-resistant sealing rubber material. The difference from Example 1 is that the accelerator is not loaded with lignin. Specifically: Step 1: Preparation of epoxidized styrene butadiene rubber 100 g of styrene butadiene rubber 1502 was dissolved in cyclohexane to prepare a styrene butadiene rubber solution with a mass fraction of 10%. 34.5 g of m-chloroperbenzoic acid was dissolved in tetrahydrofuran to prepare a m-chloroperbenzoic acid solution with a mass fraction of 35%. After the styrene butadiene rubber solution was heated to 35°C, the m-chloroperbenzoic acid solution was slowly added with continuous stirring and the reaction was carried out for 1 hour. After the reaction was completed, the pH was adjusted to 8 with sodium hydroxide solution, and then the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain epoxidized styrene butadiene rubber.

[0041] Step 2: Preparation of hydroxylated styrene butadiene rubber 100 g of epoxidized styrene butadiene rubber was dissolved in tetrahydrofuran to prepare a 10% by mass epoxidized styrene butadiene rubber solution. 10.9 g of a 36.5% by mass hydrochloric acid solution was slowly added to the epoxidized styrene butadiene rubber solution and reacted at 35°C for 2 h. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain hydroxylated styrene butadiene rubber.

[0042] Step 3: Preparation of anti-aging modified styrene-butadiene rubber 100 g of hydroxylated styrene butadiene rubber was dissolved in dichloromethane to prepare a hydroxylated styrene butadiene rubber solution with a mass fraction of 10%. 19.4 g of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 4.3 g of 4-pyrrolidinopyridine were added to the hydroxylated styrene butadiene rubber solution. After stirring and activation for 1 h, 16.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride was added. The mixture was stirred and reacted at room temperature for 24 h under nitrogen as a protective gas. After the reaction was completed, the mixture was flocculated, precipitated and dried in anhydrous ethanol to obtain anti-aging modified styrene butadiene rubber.

[0043] Step 3: Preparation of aging-resistant sealing rubber material 80 parts of anti-aging modified styrene-butadiene rubber and 20 parts of butadiene rubber were added to an internal mixer by mass, the mixing temperature was set to 60°C and the speed was 30 rpm. After mixing for 1.5 minutes, 5 parts of zinc oxide and 2 parts of stearic acid were added in sequence, the speed was increased to 35 rpm, and after mixing for 5 minutes, 45 parts of white carbon black and 5 parts of aromatic oil were added. The temperature was raised to 150°C and the speed was increased to 45 rpm. After continuing to mix for 2 minutes, the rubber was discharged and cooled to room temperature. The cooled discharged rubber was placed in an open mixer and continued to be mixed. After it was rolled, 2 parts of sulfur and 15 parts of accelerator N-cyclohexyl-2-benzothiazole sulfonamide were added. The left and right cutters were used 6 times and the triangle package and roll package were made 6 times. After mixing evenly, it was cooled and discharged. The sheet was vulcanized at 145°C for 30 minutes using a flat vulcanizer to obtain an aging-resistant sealing rubber material.

[0044] Detection experiment: Sealing rubber materials were prepared according to the preparation methods of Example 1, Example 2, Example 3, Example 4, Comparative Example 1, Comparative Example 2, and Comparative Example 3, respectively.

[0045] Mechanical property test: The mechanical property test was conducted in accordance with "Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties" (GB / T 528-2009). Dumbbell-shaped specimens (35 mm × 6 mm, with a narrow portion 12 mm long and 2 mm wide) were cut from the prepared sealing rubber material using a cutter. The cut specimens were fixed on a tensile testing machine to measure the tensile strength and elongation at break. The tensile speed was 500 mm / min, and each sealing rubber material was measured five times.

[0046] Thermal oxygen aging resistance test: The thermal oxygen aging resistance test is based on the "Hot Air Accelerated Aging and Heat Resistance Test for Vulcanized Rubber or Thermoplastic Rubber" (GB / T 3512-2014). The test is conducted in a GT-7014-E thermal aging oven. Two sets of dumbbell-shaped specimens (35mm×6mm, with a narrow part of 12mm long and 2mm wide) are cut out of the prepared sealing rubber material using a cutter. The specimens are vertically hung in the thermal aging oven, and the aging temperature is set at 100°C. The aging times for the two sets of specimens are set to 3 days and 7 days, respectively. After the aging time is reached, the specimens are removed and the tensile strength and elongation at break of the specimens after different aging times are measured using a tensile testing machine.

[0047]

[0048] Conclusion: It can be seen from the test data that the tensile strength, elongation at break of the aging-resistant sealing rubber material prepared by the preparation process of Example 1, and the tensile strength and elongation at break after thermal oxidative aging for 3 days and 7 days are better than those of the aging-resistant sealing rubber materials prepared by the preparation processes of Comparative Example 1, Comparative Example 2 and Comparative Example 3. The aging-resistant sealing rubber material prepared by the preparation process of Example 1 has good mechanical properties and aging resistance, and can solve the problem of insufficient aging resistance of sealing rubber materials.

[0049] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A process for preparing an aging-resistant sealing rubber material, characterized in that: Specifically: The anti-aging modified rubber, butadiene rubber, zinc oxide, stearic acid, white carbon black, aromatic oil, sulfur and lignin as a loading accelerator are mixed evenly, cooled, sheeted and vulcanized to obtain an anti-aging sealing rubber material.

2. The process for preparing an aging-resistant sealing rubber material according to claim 1, characterized in that: Calculated by mass, the amount of each component in the aging-resistant sealing rubber material is: 75 to 85 parts of anti-aging modified styrene-butadiene rubber, 75 to 85 parts of butadiene rubber, 75 to 85 parts of zinc oxide, 75 to 85 parts of stearic acid, 75 to 85 parts of white carbon black, 75 to 85 parts of aromatic oil, 75 to 85 parts of sulfur, and 75 to 85 parts of loaded promoter lignin.

3. The process for preparing an aging-resistant sealing rubber material according to claim 1, characterized in that: The preparation method of anti-aging modified styrene-butadiene rubber is: Dissolving styrene butadiene rubber in cyclohexane to prepare a styrene butadiene rubber solution, dissolving meta-chloroperbenzoic acid in tetrahydrofuran to prepare a meta-chloroperbenzoic acid solution, heating the styrene butadiene rubber solution to 30-40° C., slowly adding the meta-chloroperbenzoic acid solution while stirring continuously, reacting for 0.5-1 hour, adjusting the pH to 7-8 with a sodium hydroxide solution after the reaction is completed, and then flocculating, precipitating, and drying in anhydrous ethanol to obtain epoxidized styrene butadiene rubber; The epoxidized styrene butadiene rubber is dissolved in tetrahydrofuran to prepare an epoxidized styrene butadiene rubber solution, hydrochloric acid is slowly added to the epoxidized styrene butadiene rubber solution, and the mixture is reacted at 30 to 40° C. for 1 to 3 hours. After the reaction is completed, the mixture is flocculated, precipitated, and dried in anhydrous ethanol to obtain a hydroxylated styrene butadiene rubber. Hydroxylated styrene butadiene rubber is dissolved in dichloromethane to prepare hydroxylated styrene butadiene rubber solution, 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid and 4-pyrrolidinopyridine are added to the hydroxylated styrene butadiene rubber solution, and after stirring and activating for 0.5 to 1 hour, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is added, and the mixture is stirred and reacted at room temperature for 20 to 26 hours under nitrogen as a protective gas. After the reaction is completed, the mixture is flocculated, precipitated and dried in anhydrous ethanol to obtain anti-aging modified styrene butadiene rubber.

4. The process for preparing an aging-resistant sealing rubber material according to claim 3, characterized in that: The mass fraction of styrene butadiene in the styrene butadiene rubber solution is 5-15%, the mass fraction of chloroperbenzoic acid in the meta-chloroperbenzoic acid solution is 30-40%, and the mass ratio of styrene butadiene to meta-chloroperbenzoic acid is (95-105): (33-37).

5. The process for preparing an aging-resistant sealing rubber material according to claim 3, characterized in that: The mass fraction of epoxidized styrene butadiene in the epoxidized styrene butadiene rubber solution is 5-15%, and the mass ratio of epoxidized styrene butadiene to hydrochloric acid is (95-105):(10-12).

6. The process for preparing an aging-resistant sealing rubber material according to claim 3, characterized in that: Calculated by mass, the amount of each component in the anti-aging modified styrene-butadiene rubber is: 95 to 105 parts of hydroxylated styrene-butadiene, 19 to 20 parts of 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid, 4 to 5 parts of 4-pyrrolidinopyridine, and 16 to 17 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride.

7. The process for preparing an aging-resistant sealing rubber material according to claim 1, characterized in that: The preparation method of the loaded promoter lignin is as follows: Adding lignin and silane coupling agent KH-560 to a mixed solution of anhydrous ethanol and deionized water, stirring evenly, stirring and reacting at 50-70° C. and 1400-1600 rpm for 1.5-2.5 hours, cooling after the reaction is completed, filtering, washing with anhydrous ethanol and deionized water, and drying to obtain silane coupling agent-modified lignin; N-cyclohexyl-2-benzothiazolesulfenamide is added to a mixed solution of anhydrous ethanol and deionized water, and after stirring evenly, a silane coupling agent is added to modify the lignin. The mixture is stirred at 60-80° C. for 3-5 hours. After the reaction is completed, the mixture is cooled, filtered, washed with anhydrous ethanol, and dried to obtain the promoter-loaded lignin.

8. The process for preparing an aging-resistant sealing rubber material according to claim 7, characterized in that: The mass ratio of lignin, silane coupling agent KH-560, and N-cyclohexyl-2-benzothiazolesulfenamide is (5-15): (3-7): (0.3-0.7).

9. The process for preparing an aging-resistant sealing rubber material according to claim 1, characterized in that: The specific steps of mixing and vulcanizing to prepare the aging-resistant sealing rubber material are as follows: Anti-aging modified styrene-butadiene rubber and butadiene rubber are added to an internal mixer, the mixing temperature is set to 50-70°C, the speed is set to 20-30 rpm, after mixing for 1-3 minutes, zinc oxide and stearic acid are added in sequence, the speed is increased to 30-40 rpm, after mixing for 5-10 minutes, white carbon black and aromatic oil are added, the temperature is raised to 140-160°C, the speed is increased to 40-50 rpm, the mixing is continued for 1-3 minutes, the rubber is discharged, and the rubber is cooled to room temperature; the cooled discharged rubber is placed in an open mixer and continued to be mixed, and sulfur and a load accelerator lignin are added after the rubber is rolled. The rubber is cut left and right 3-7 times and triangularly packaged and rolled 3-7 times. After mixing evenly, the rubber is cooled and discharged, and the rubber is vulcanized at 130-150°C for 30-50 minutes using a flat vulcanizer to obtain an aging-resistant sealing rubber material.

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