Temperature-resistant and corrosion-resistant rubber composition for sealing electrolytic cell and preparation method of temperature-resistant and corrosion-resistant rubber composition

Abstract

The invention provides a temperature-resistant anti-corrosion rubber composition for sealing an electrolytic bath, which comprises the following components in parts by weight: 20-40 parts of fluororubber, 50-80 parts of perfluoroether rubber, 7-15 parts of carbon black, 3-7 parts of sulfur, 3-8 parts of plasticizer, 4-6 parts of reinforcing fiber, 10-15 parts of reinforcing supplement, 3-10 parts of anti-aging agent, 1-7 parts of scorch retarder, 1-4 parts of anti-reversion agent and 1-4 parts of accelerant. According to the temperature-resistant and corrosion-resistant rubber composition for sealing the electrolytic cell, disclosed by the invention, the fluororubber and the perfluoroether rubber are mixed, and the carbon black and the sulfur are added for mixing, so that the corrosion resistance of the rubber is greatly enhanced, the temperature resistance is improved, and reinforcing fibers and a nano reinforcing supplement are added in the mixing process; a framework-node-rubber structure is formed in rubber after full mixing at a certain temperature, the strength of the rubber in the using process can be greatly enhanced through microscopic modification, meanwhile, the temperature resistance and corrosion resistance of the rubber are further improved, and the sealing problem in the using process of an electrolytic cell is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of electrolytic cell sealing, and in particular relates to a temperature-resistant and corrosion-resistant rubber composition for electrolytic cell sealing and a preparation method thereof. Background Art

[0002] Sealing rubber is a major component of the electrolytic cell. Due to the long-term operation of the electrolytic cell in a relatively high temperature and acid-base corrosive environment, the sealing rubber is prone to aging and corrosion, causing leakage in the electrolytic cell. Especially during start-up and shutdown conditions and conditions with large external temperature fluctuations, there will be significant thermal expansion and contraction. Due to the large differences in thermal expansion and contraction coefficients between the sealing rubber and metal materials such as the tie rod plates, leakage in the electrolytic cell can also be easily caused. Electrolytic cell leakage can affect the operating environment and the life of the electrolytic cell, and may even lead to safety accidents, so sealing is extremely important. Furthermore, the electrolytic cell sealing material also requires good insulation properties, which is one of the key design requirements for ensuring efficient, safe, stable, and reliable operation of the electrolysis process. Therefore, sealing materials with excellent electrical insulation properties that can withstand electrolyte corrosion and operating temperature and pressure are crucial.

[0003] Rubber materials have excellent insulating properties and are commonly used for electrolytic cell seals. However, existing sealing rubbers fail to meet the required heat resistance, strength, and fatigue resistance for electrolytic cell seals, necessitating frequent replacement. Currently, no electrolytic cell-specific sealing rubber materials have been reported that are both heat-resistant and resistant to acid and alkali corrosion. Therefore, there is an urgent need to develop a sealing rubber specifically for electrolytic cells that offers excellent heat resistance (-50°C to +200°C), high strength, and excellent acid and alkali corrosion resistance. Summary of the Invention

[0004] The purpose of the present invention is to provide a sealing rubber with good insulation performance, heat resistance, corrosion resistance and high strength specially used for electrolytic cells and a preparation method thereof, so as to solve the problem that the existing sealing rubber used in electrolytic cells is prone to aging and corrosion, causing leakage of the electrolytic cell.

[0005] The technical solution of the present invention is: a temperature-resistant and anti-corrosion rubber composition for electrolytic cell sealing, comprising the following components in parts by weight: 20-40 parts of fluororubber, 50-80 parts of perfluoroether rubber, 7-15 parts of carbon black, 3-7 parts of sulfur, 3-8 parts of plasticizer, 4-6 parts of reinforcing fiber, 10-15 parts of reinforcing supplement, 3-10 parts of antioxidant, 1-7 parts of scorch retarder, 1-4 parts of anti-reversion agent, and 1-4 parts of accelerator.

[0006] Furthermore, the fluororubber is a ternary copolymer of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene, and the fluorine content is greater than 70%.

[0007] Furthermore, the plasticizer is isoparaffin solvent oil, kerosene or a mixture of isoparaffin solvent oil and kerosene.

[0008] Furthermore, the reinforcing fiber is a mixed fiber of carbon fiber, silicon carbide fiber, calcium carbonate fiber and alumina fiber, with a fiber diameter of 0.1-1 μm and a fiber length of 10-20 μm, and the weight proportions are 3-5 of carbon fiber, 5-8 of silicon carbide fiber, 5-10 of calcium carbonate fiber and 1-4 of alumina fiber.

[0009] Furthermore, the enhancement supplement is one or more of nano-titanium oxide microspheres, nano-calcium carbonate microspheres, nano-aluminum oxide microspheres, and nano-silicon dioxide microspheres, and the diameter of the microspheres is 100-1000 nm.

[0010] Furthermore, the antioxidant is one of di-tert-butyl-p-cresol, styrenated phenol, or a mixture of the two, and the scorch retarder is one or more of benzoic acid, phthalic acid, salicylic acid, N-nitroso-diphenylamine, and N-cyclohexylthiophthalimide.

[0011] Furthermore, the anti-reversion agent is one or more of hexamethylene-1,6-dithiosulfate disodium salt, N,N′-m-phenylene bismaleimide, and 1,3-bis(citramidomethyl)benzene.

[0012] Furthermore, the accelerator is one or more of zinc dimethyldithiocarbamate, tetraethylthiuram disulfide, and zinc dibutyldithiocarbamate.

[0013] A method for preparing a heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing comprises the following steps: firstly, adding fluororubber, perfluoroether rubber, carbon black, sulfur, and a plasticizer according to their respective proportions into an internal mixer, and kneading them at 120-150° C. for 30-60 minutes to obtain a preliminary rubber mixture; then, adding reinforcing fiber, reinforcing supplement, anti-aging agent, anti-scorching agent, and anti-reversion agent into the rubber mixture, and kneading them at 100-130° C. in the internal mixer for 60-120 minutes; finally, adding an accelerator, and kneading them at 90-110° C. in an open mixer for 20-40 minutes; and processing and molding the mixture to obtain the heat-resistant and corrosion-resistant rubber composition.

[0014] The heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing disclosed in the present invention is prepared by mixing fluororubber and perfluoroether rubber, and then adding carbon black and sulfur to the mixed mixture, thereby greatly enhancing the corrosion resistance and insulation properties of the rubber and improving the heat resistance. Reinforcing fibers and nano-reinforcement supplements are added during the mixing process, and after sufficient mixing at a certain temperature, a skeleton-node-rubber structure is formed inside the rubber. Microscopic modification can greatly enhance the strength of the rubber during use, while further improving the heat resistance and corrosion resistance of the rubber, thereby solving the sealing problem during the use of the electrolytic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an electron microscope photograph of the rubber composition of the present invention; Figure 2 This is the mass loss curve of the rubber composition prepared in Example 1 after immersion in 10% sodium hydroxide solution; Figure 3 This is the mass loss curve of the rubber composition prepared in Example 1 after immersion in 10% sulfuric acid solution. DETAILED DESCRIPTION Example

[0016] A heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing comprises the following components in parts by weight: 20 parts of fluororubber, 80 parts of perfluoroether rubber, 7 parts of carbon black, 3 parts of sulfur, 8 parts of plasticizer, 4 parts of reinforcing fiber, 10 parts of reinforcing supplement, 3 parts of antioxidant, 1 part of scorch retarder, 1 part of anti-reversion agent, and 1 part of accelerator.

[0017] The fluororubber used is a terpolymer of vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene, with a fluorine content of 71%. The plasticizer is a mixture of isoparaffin solvent oil and kerosene. The reinforcing fiber is a blend of carbon fiber, silicon carbide fiber, calcium carbonate fiber, and aluminum oxide fiber, with a fiber diameter of 0.1 μm and a fiber length of 10 μm. The weight ratio is 3 parts carbon fiber, 5 parts silicon carbide fiber, 10 parts calcium carbonate fiber, and 4 parts aluminum oxide fiber. The reinforcing agent is a mixture of nano-titanium oxide microspheres, nano-calcium carbonate microspheres, nano-aluminum oxide microspheres, and nano-silica microspheres, with a mixing ratio of 1:1:1:1, and a microsphere diameter of 500 nm. The antioxidant used is di-tert-butyl-p-cresol, the anti-scorch agent is benzoic acid, the anti-reversion agent is hexamethylene-1,6-dithiosulfate disodium salt, and the accelerator is zinc dimethyldithiocarbamate.

[0018] A method for preparing a heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing comprises the following steps: firstly, adding fluororubber, perfluoroether rubber, carbon black, sulfur, and a plasticizer according to their respective proportions into an internal mixer, and kneading them at 120°C for 60 minutes to obtain a preliminary rubber mixture; then, adding reinforcing fiber, reinforcing supplement, anti-aging agent, anti-scorching agent, and anti-reversion agent into the rubber mixture, and kneading them at 100°C for 120 minutes in the internal mixer; finally, adding an accelerator, and kneading them at 90°C in an open mixer for 20 minutes; and processing and molding the mixture to obtain the heat-resistant and corrosion-resistant rubber composition.

[0019] The electron microscope photograph of the rubber composition obtained in this example is shown in the attached Figure 1 As shown in the figure, the reinforcing fibers and the nano-microspheres of the reinforcing agent can be clearly seen. The prepared rubber composition is processed into a 5mm*5mm rubber strip and immersed in a 10% sodium hydroxide solution and a 10% sulfuric acid solution for 30 days. The mass loss is shown in the attached figure. Figure 2 and attached Figure 3The comparison of the heat resistance and tensile strength of the rubber composition prepared in this embodiment with those of commonly used EPDM rubber, fluororubber, and butyl rubber is shown in Table 1.

[0020] Table 1 Performance parameter comparison Serial number Rubber Type Temperature resistance ℃ Tensile breaking strength MPa 1 Example 1 Rubber composition 220 42 2 EPDM 150 30 3 Fluororubber 200 33 4 Butyl rubber 100 28 Example

[0021] A heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing comprises the following components in parts by weight: 40 parts of fluororubber, 50 parts of perfluoroether rubber, 15 parts of carbon black, 7 parts of sulfur, 3 parts of a plasticizer, 6 parts of reinforcing fiber, 15 parts of a reinforcing supplement, 10 parts of an antioxidant, 1 part of a scorch retarder, 4 parts of an anti-reversion agent, and 4 parts of an accelerator.

[0022] The fluororubber used is a terpolymer of vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene, with a fluorine content of 72%. The plasticizer is isoparaffin solvent oil. The reinforcing fibers are a blend of carbon fiber, silicon carbide fiber, calcium carbonate fiber, and aluminum oxide fiber, with a fiber diameter of 1 μm and a fiber length of 20 μm. The weight ratio is 5 parts carbon fiber, 8 parts silicon carbide fiber, 5 parts calcium carbonate fiber, and 1 part aluminum oxide fiber. The reinforcing agent is a mixture of titanium dioxide nanospheres, calcium carbonate nanospheres, aluminum oxide nanospheres, and silicon dioxide nanospheres, with a mixing ratio of 1:2:2:1, and a microsphere diameter of 100 nm. The antioxidant used is styrenated phenol, the anti-scorch agent is phthalic acid, the anti-reversion agent is N′-m-phenylene bismaleimide, and the accelerator is tetraethylthiuram disulfide.

[0023] A method for preparing a heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing comprises the following steps: firstly, adding fluororubber, perfluoroether rubber, carbon black, sulfur, and a plasticizer according to their respective proportions into an internal mixer, and kneading them at 150° C. for 30 minutes to obtain a preliminary rubber mixture; then, adding reinforcing fiber, reinforcing supplement, anti-aging agent, anti-scorching agent, and anti-reversion agent into the rubber mixture, and kneading them at 130° C. in the internal mixer for 60 minutes; finally, adding an accelerator, and kneading them at 110° C. in an open mixer for 40 minutes; and processing and molding the mixture to obtain the heat-resistant and corrosion-resistant rubber composition.

[0024] Table 2 shows the comparison of the heat resistance and tensile strength of the rubber composition prepared in this example with those of commonly used EPDM rubber, fluororubber, and butyl rubber.

[0025] Table 2 Performance parameter comparison Serial number Rubber Type Temperature resistance ℃ Tensile breaking strength MPa 1 Example 2 Rubber composition 260 51 2 EPDM 150 30 3 Fluororubber 200 33 4 Butyl rubber 100 28 Example

[0026] A heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing comprises the following components in parts by weight: 30 parts of fluororubber, 60 parts of perfluoroether rubber, 7-15 parts of carbon black, 5 parts of sulfur, 5 parts of plasticizer, 5 parts of reinforcing fiber, 12 parts of reinforcing supplement, 8 parts of antioxidant, 6 parts of scorch retarder, 3 parts of anti-reversion agent, and 3 parts of accelerator.

[0027] The fluororubber used is a terpolymer of vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene, with a fluorine content of 73%. The plasticizer is kerosene. The reinforcing fibers are a blend of carbon fiber, silicon carbide fiber, calcium carbonate fiber, and aluminum oxide fiber, with a fiber diameter of 0.5 μm and a fiber length of 15 μm. The weight ratio is 4 parts carbon fiber, 6 parts silicon carbide fiber, 6 parts calcium carbonate fiber, and 3 parts aluminum oxide fiber. The reinforcing supplement is a mixture of titanium oxide nano-microspheres, calcium carbonate nano-microspheres, aluminum oxide nano-microspheres, and silicon dioxide nano-microspheres, with a mixing ratio of 2:1:2:1, and the microspheres have a diameter of 1000 nm. The antioxidant used is a mixture of di-tert-butyl-p-cresol and styrenated phenol, the scorch retarder is a mixture of salicylic acid and N-nitroso-diphenylamine, the anti-sulfurization reversion agent is a mixture of hexamethylene-1,6-dithiosulfate disodium salt and 1,3-bis(citrafurylimidemethyl)benzene, and the accelerator is a mixture of zinc dimethyldithiocarbamate and zinc dibutyldithiocarbamate.

[0028] A method for preparing a heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing comprises the following steps: firstly, adding fluororubber, perfluoroether rubber, carbon black, sulfur, and a plasticizer according to their respective proportions into an internal mixer, and kneading them at 130°C for 40 minutes to obtain a preliminary rubber mixture; then, adding reinforcing fiber, reinforcing supplement, anti-aging agent, anti-scorching agent, and anti-reversion agent into the rubber mixture, and kneading them at 120°C for 100 minutes in the internal mixer; finally, adding an accelerator, and kneading them at 100°C in an open mixer for 30 minutes; and processing and molding the mixture to obtain the heat-resistant and corrosion-resistant rubber composition.

[0029] Table 2 shows the comparison of the heat resistance and tensile strength of the rubber composition prepared in this example with those of commonly used EPDM rubber, fluororubber, and butyl rubber.

[0030] Table 3 Performance parameter comparison Serial number Rubber Type Temperature resistance ℃ Tensile breaking strength MPa 1 Example 3 Rubber composition 240 48 2 EPDM 150 30 3 Fluororubber 200 33 4 Butyl rubber 100 28 While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing, characterized in that: The invention comprises the following components in parts by weight: 20-40 parts of fluororubber, 50-80 parts of perfluoroether rubber, 7-15 parts of carbon black, 3-7 parts of sulfur, 3-8 parts of plasticizer, 4-6 parts of reinforcing fiber, 10-15 parts of reinforcing supplement, 3-10 parts of antioxidant, 1-7 parts of scorch retarder, 1-4 parts of anti-reversion agent and 1-4 parts of accelerator.

2. The heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing according to claim 1, characterized in that: The fluororubber is a ternary copolymer of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene, and the fluorine content is greater than 70%.

3. The heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing according to claim 1, characterized in that: The plasticizer is isoparaffin solvent oil, kerosene or a mixture of isoparaffin solvent oil and kerosene.

4. The heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing according to claim 1, characterized in that The reinforcing fiber is a mixed fiber of carbon fiber, silicon carbide fiber, calcium carbonate fiber and aluminum oxide fiber, with a fiber diameter of 0.1-1 μm and a fiber length of 10-20 μm. The weight proportions are 3-5 of carbon fiber, 5-8 of silicon carbide fiber, 5-10 of calcium carbonate fiber and 1-4 of aluminum oxide fiber.

5. The heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing according to claim 1, characterized in that The enhancement supplement is one or more of nano titanium oxide microspheres, nano calcium carbonate microspheres, nano aluminum oxide microspheres, and nano silicon dioxide microspheres, and the diameter of the microspheres is 100-1000 nm.

6. The heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing according to claim 1, characterized in that The antioxidant is one of di-tert-butyl-p-cresol and styrenated phenol or a mixture of the two, and the scorch retarder is one or more of benzoic acid, phthalic acid, salicylic acid, N-nitroso-diphenylamine, and N-cyclohexylthiophthalimide.

7. The heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing according to claim 1, characterized in that The anti-reversion agent is one or more of hexamethylene-1,6-dithiosulfate disodium salt, N,N'-m-phenylene bismaleimide, and 1,3-bis(citrafurimidemethyl)benzene.

8. The heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing according to claim 1, characterized in that The accelerator is one or more of zinc dimethyldithiocarbamate, tetraethylthiuram disulfide, and zinc dibutyldithiocarbamate.

9. The method for preparing a heat-resistant and corrosion-resistant rubber composition for electrolytic cell sealing according to claims 1-8, characterized in that: The method comprises the following steps: First, fluororubber, perfluoroether rubber, carbon black, sulfur, and plasticizer are added to an internal mixer according to their weight and kneaded at 120-150° C. for 30-60 minutes to obtain a preliminary rubber mixture. Then, reinforcing fiber, reinforcing supplement, antioxidant, scorch retarder, and anti-reversion agent are added to the rubber mixture and kneaded at 100-130° C. for 60-120 minutes in an internal mixer. Finally, an accelerator is added and kneaded at 90-110° C. in an open mixer for 20-40 minutes. The heat-resistant and corrosion-resistant rubber composition is obtained by processing and molding.

Images