A corrosion-resistant sealing ring material and its preparation method

Abstract

This invention relates to a corrosion-resistant sealing ring material and its preparation method, belonging to the technical field of fluororubber sealing materials. The sealing ring material comprises: 100 parts fluororubber, 4.2-5.5 parts potassium titanate whiskers, 6.8-9.3 parts organosilicon additives, 12-15 parts reinforcing agent, 2.4-3.1 parts vulcanizing agent, 0.5-0.7 parts accelerator, and 1.5-2 parts activator. The potassium titanate whiskers and organosilicon additives synergistically modify the material. The organosilicon barrier slows down the initial solvent penetration rate, and the whisker network blocks the transmission of swelling deformation, allowing the material to maintain a tighter cross-linking density at swelling equilibrium. This ensures stable contact pressure at the sealing interface in harsh media, completely resolving the contradiction between "suppressing swelling" and "maintaining elasticity" in traditional modification techniques, and significantly improving the swelling and corrosion resistance of the sealing ring material.

Description

Technical Field

[0001] This invention belongs to the technical field of fluororubber sealing materials, specifically, it relates to a corrosion-resistant sealing ring material and its preparation method. Background Technology

[0002] In modern industry, sealing technology is a core component ensuring the stable operation of hydraulic and pneumatic systems. Sealing materials, constantly in contact with lubricants and chemical media, are susceptible to corrosion and swelling, leading to seal failure. Rubber materials, due to their excellent elasticity and adaptability, have become the primary choice for sealing systems. Among them, fluororubber, with its high fluorine content in its molecular chain, exhibits outstanding chemical corrosion resistance and is widely used in harsh environments such as petroleum, chemical, and aerospace industries.

[0003] However, fluororubber is prone to swelling in media such as organic solvents and lubricating oils, leading to a decrease in its corrosion resistance. During the swelling process, the molecular chains extend after the medium penetrates, and shrinkage upon unloading generates alternating internal stress, inducing micro-cracks. The increased volume of the swollen seal increases the dynamic seal contact pressure, raises the friction coefficient, and accelerates wear. Therefore, corrosion caused by the swelling of the sealing ring material is a significant factor leading to seal failure. Existing improvement methods have the following drawbacks: 1. Using high-fluorine-content rubber to increase the fluorine content and enhance the molecular chain shielding ability, but the high cost limits its application; 2. Blending swelling-resistant materials, such as using silicone rubber, easily leads to interface defects due to insufficient compatibility and anti-migration properties, affecting sealing performance; 3. Increasing the crosslinking density can inhibit swelling, but the material becomes harder and more brittle, reducing the sealing effect and posing a significant risk. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background art, the purpose of this invention is to provide a corrosion-resistant sealing ring material and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A corrosion-resistant sealing ring material, comprising the following components by weight: 100 parts fluororubber, 4.2-5.5 parts potassium titanate whiskers, 6.8-9.3 parts organosilicon additives, 12-15 parts reinforcing agent, 2.4-3.1 parts vulcanizing agent, 0.5-0.7 parts accelerator, and 1.5-2 parts activator.

[0007] The organosilicon additive is prepared by the following method:

[0008] Step A1: Under nitrogen protection, premix single-ended hydrogen-containing silicone oil, allyl glycidyl ether and toluene, then add platinum catalyst and mix. Heat to 75-90℃ and stir for 4.5-6.2h. After the reaction is completed, remove toluene by rotary evaporation under reduced pressure. After the substrate is cooled to room temperature, add deionized water to wash, centrifuge to separate the aqueous phase and vacuum dry to obtain ether-containing epoxy intermediate.

[0009] Furthermore, the ratio of the silane content of the single-ended hydrogen-containing silicone oil, allyl glycidyl ether, platinum catalyst, and toluene is 0.1 mol: 0.15-0.18 mol: 0.08-0.1 g: 300-400 mL. The allyl glycidyl ether undergoes hydrosilylation with the single-ended hydrogen-containing silicone oil, introducing an ether-containing epoxy structure to the molecular end of the single-ended hydrogen-containing silicone oil for end capping.

[0010] Furthermore, single-ended hydrogen-containing silicone oils have a relative molecular weight of no more than 3000, exhibiting good reactivity. The moderate silicon chain length facilitates dispersion in fluororubber systems and the formation of a good shielding effect.

[0011] Step A2: Premix the ether-containing epoxy intermediate, tetrabutylammonium bromide and acetone, control the temperature in a water bath at 35-45℃, slowly add tris(2-aminoethyl)amine and stir for 2-3 hours, then raise the temperature to 60℃ and reflux for 30-50 minutes. After the reaction is complete, remove the acetone by rotary evaporation. Wash the substrate with ethanol and deionized water in sequence and dry to obtain the organosilicon additive.

[0012] Furthermore, the ratio of tri(2-aminoethyl)amine, the epoxy content of the ether-containing epoxy intermediate, the amount of tetrabutylammonium bromide, and the amount of acetone is 10 mmol: 35-40 mmol: 20-30 mg: 220-300 mL, and the ether-containing epoxy intermediate undergoes ring-opening with tri(2-aminoethyl)amine.

[0013] Preferably, the length of the potassium titanate whiskers is controlled at 3-5 μm and the aspect ratio is controlled at 10-15. The whiskers under this size specification maintain good dispersion and can also play a good pinning and strengthening effect.

[0014] Preferably, the accelerator is composed of bisphenol AF and benzyltriphenylphosphine chloride, which can quickly and efficiently promote the crosslinking of fluororubber, forming a uniform crosslinking network, which is beneficial to improving the swelling resistance of the sealing ring.

[0015] A method for preparing a corrosion-resistant sealing ring material, specifically comprising:

[0016] Step S1: Mix fluororubber and silicone additives and grind them together. Add potassium carbonate whiskers, reinforcing agent, accelerator, activator and vulcanizing agent in sequence and mix evenly. Cut into thin sheets to obtain composite rubber.

[0017] Step S2: The composite rubber material is molded and then transferred into a vulcanizing kettle for vulcanization to obtain the sealing ring material.

[0018] Furthermore, the molding temperature is 160-170℃, the pressure is 10-12MPa, the vulcanization temperature is 190-200℃, and the vulcanization time is 2.5-3h.

[0019] The beneficial effects of this invention are:

[0020] This invention employs potassium titanate whiskers and organosilicon additives for synergistic modification, constructing an organic-inorganic synergistic anti-swelling network in a fluororubber matrix, significantly improving the swelling and corrosion resistance of the sealing ring material; the organosilicon additive is prepared by hydrosilylation of single-end hydrogen-capped silicone oil with allyl glycidyl ether to form an ether-containing epoxy intermediate, and then ring-opening of the ether-containing epoxy intermediate with tris(2-aminoethyl)amine to form the organosilicon additive.

[0021] Compared with existing technologies, the organosilicon additive molecules have a radially branched central structure. The molecular center is enriched with secondary amines and hydroxyl groups formed by ring-opening reactions, which form hydrogen bonds with the fluorine structures in the fluororubber macromolecular chain. This allows the organosilicon additive to be uniformly dispersed and anchored in the fluororubber matrix. At the same time, the polyamine structure at the center of the organosilicon additive molecule forms a chelating effect, which then combines with potassium titanate whiskers, improving its compatibility. In terms of anti-swelling mechanism, the organosilicon segments construct a solvent-repellent barrier between the fluororubber molecular chains, forcing solvent molecules to bypass the toughened penetration path. The potassium titanate whiskers, through their high-rigidity structural physical pinning of the cross-linked network, generate a reverse restraining force when solvent molecules attempt to open the rubber chain, significantly inhibiting the movement of the macromolecular chain segments. The synergistic effect of the two is as follows: the organosilicon barrier slows down the initial solvent penetration rate, and the whisker network blocks the transmission of swelling deformation, so that the material maintains a tighter cross-linking density when the swelling is in equilibrium. This ensures the stability of the contact pressure of the sealed interface in harsh media, and completely solves the contradiction between "suppressing swelling" and "preserving elasticity" in traditional modification technology. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: Preparation of corrosion-resistant sealing ring material. The specific implementation process is as follows:

[0024] (1) Preparation of organosilicon additives

[0025] Step A1: Under nitrogen protection, premix single-ended hydrogen-containing silicone oil, allyl glycidyl ether, and toluene, then add platinum catalyst and mix. Heat to 75℃ and stir for 6.2 h. The single-ended hydrogen-containing silicone oil is IOTA-611 type raw material, and the platinum catalyst is 5000ppm Castrol catalyst. The ratio of the hydrogen silane content of the single-ended hydrogen-containing silicone oil, allyl glycidyl ether, platinum catalyst, and toluene is 0.1mol:0.15mol:0.08g:300mL. After the reaction is completed, remove toluene by rotary evaporation under reduced pressure. After the substrate is cooled to room temperature, add deionized water to wash, centrifuge to separate the aqueous phase, and vacuum dry to obtain the ether-containing epoxy intermediate.

[0026] Step A2: Premix the ether-containing epoxy intermediate, tetrabutylammonium bromide, and acetone. Control the temperature in a water bath at 35°C, slowly add tris(2-aminoethyl)amine, and stir for 3 hours. Then, heat to 60°C and reflux for 50 minutes. The ratio of tris(2-aminoethyl)amine, epoxy group content of the ether-containing epoxy intermediate, and the amount of tetrabutylammonium bromide to acetone is 10 mmol: 35 mmol: 20 mg: 220 mL. After the reaction is complete, remove the acetone by rotary evaporation. Wash the substrate with ethanol and deionized water in sequence and dry to obtain the organosilicon additive.

[0027] (2) Preparation of sealing ring material

[0028] Ingredients: 100 parts fluororubber, Viton B-600 type raw rubber; 4.2 parts potassium titanate whiskers, commercially available high-purity powder, with an average whisker length of 3.2 μm and an aspect ratio of 10; 6.8 parts organosilicon additives, prepared in this embodiment; 15 parts reinforcing agent, commercially available N990 type carbon black; 2.4 parts vulcanizing agent, bisphenol A; 0.5 parts accelerator, composed of bisphenol AF and benzyltriphenylphosphine chloride in a weight ratio of 3:1; 1.5 parts activator, magnesium oxide.

[0029] Step S1: Mix fluororubber and silicone additives and add them to the open mill. Control the roller temperature to 55℃ and mill for 12 minutes. Add potassium carbonate whiskers, reinforcing agent, accelerator, activator and vulcanizing agent in sequence and mix for 30 minutes. Adjust the roller gap to 5mm and pass through the mill 10 times to obtain the composite rubber material.

[0030] Step S2: The composite rubber material is molded with the following parameters: temperature 160℃, pressure 10MPa, holding pressure for 10min, and then transferred to a vulcanizing kettle with the temperature controlled at 190℃ and the vulcanization time at 2.5h. The sealing ring material is obtained by vulcanization.

[0031] Example 2: Preparation of corrosion-resistant sealing ring material. The specific implementation process is as follows:

[0032] (1) Preparation of organosilicon additives

[0033] Step A1: Under nitrogen protection, premix single-ended hydrogen-containing silicone oil, allyl glycidyl ether, and toluene, then add platinum catalyst and mix. Heat to 90℃ and stir for 4.5 h. The single-ended hydrogen-containing silicone oil is RH-H222-10 type raw material, and the platinum catalyst is 5000ppm Castrol catalyst. The ratio of the hydrogen silane content of the single-ended hydrogen-containing silicone oil, allyl glycidyl ether, platinum catalyst, and toluene is 0.1mol:0.18mol:0.1g:400mL. After the reaction is completed, remove toluene by rotary evaporation under reduced pressure. After the substrate is cooled to room temperature, add deionized water to wash, centrifuge to separate the aqueous phase, and vacuum dry to obtain the ether-containing epoxy intermediate.

[0034] Step A2: Premix the ether-containing epoxy intermediate, tetrabutylammonium bromide, and acetone. Control the temperature in a water bath at 45°C, slowly add tris(2-aminoethyl)amine, and stir for 2 hours. Then, heat to 60°C and reflux for 30 minutes. The ratio of tris(2-aminoethyl)amine, epoxy group content of the ether-containing epoxy intermediate, and the amount of tetrabutylammonium bromide to acetone is 10 mmol: 40 mmol: 30 mg: 300 mL. After the reaction is complete, remove the acetone by rotary evaporation. Wash the substrate with ethanol and deionized water in sequence and dry to obtain the organosilicon additive.

[0035] (2) Preparation of sealing ring material

[0036] Ingredients: 100 parts fluororubber, Viton B-600 type raw rubber; 5.5 parts potassium titanate whiskers, commercially available high-purity powder, with an average whisker length of 4.7 μm and an aspect ratio of 12; 9.3 parts organosilicon additives, prepared in this embodiment; 12 parts reinforcing agent, commercially available N990 type carbon black; 3.1 parts vulcanizing agent, bisphenol A; 0.7 parts accelerator, composed of bisphenol AF and benzyltriphenylphosphine chloride in a weight ratio of 3:1; 2 parts activator, magnesium oxide.

[0037] Step S1: Mix fluororubber and silicone additives and add them to the open mill. Control the roller temperature to 55℃ and mill for 14 minutes. Add potassium carbonate whiskers, reinforcing agent, accelerator, activator and vulcanizing agent in sequence and mix for 30 minutes. Adjust the roller gap to 5mm and pass through the mill 10 times to obtain the composite rubber material.

[0038] Step S2: The composite rubber material is molded with the following parameters: temperature 170℃, pressure 12MPa, holding pressure for 10min, and then transferred to a vulcanizing kettle with the temperature controlled at 200℃ and the vulcanization time at 3h. The sealing ring material is obtained by vulcanization molding.

[0039] Example 3: Preparation of corrosion-resistant sealing ring material, the specific implementation process is as follows:

[0040] (1) Preparation of organosilicon additives

[0041] Step A1: Under nitrogen protection, premix single-ended hydrogen-containing silicone oil, allyl glycidyl ether, and toluene, then add platinum catalyst and mix. Heat to 85℃ and stir for 5 hours. The single-ended hydrogen-containing silicone oil is RH-H222-10 type raw material, and the platinum catalyst is 5000ppm Castrol catalyst. The ratio of the hydrogen silane content of the single-ended hydrogen-containing silicone oil, allyl glycidyl ether, platinum catalyst, and toluene is 0.1mol:0.17mol:0.1g:380mL. After the reaction is completed, remove toluene by rotary evaporation under reduced pressure. After the substrate is cooled to room temperature, add deionized water to wash, centrifuge to separate the aqueous phase, and vacuum dry to obtain the ether-containing epoxy intermediate.

[0042] Step A2: Premix the ether-containing epoxy intermediate, tetrabutylammonium bromide, and acetone. Control the temperature in a water bath at 40°C, slowly add tris(2-aminoethyl)amine, and stir for 3 hours. Then, heat to 60°C and reflux for 50 minutes. The ratio of tris(2-aminoethyl)amine, epoxy group content of the ether-containing epoxy intermediate, and the amount of tetrabutylammonium bromide to acetone is 10 mmol: 40 mmol: 25 mg: 270 mL. After the reaction is complete, remove the acetone by rotary evaporation. Wash the substrate with ethanol and deionized water in sequence and dry to obtain the organosilicon additive.

[0043] (2) Preparation of sealing ring material

[0044] Ingredients: 100 parts fluororubber, Viton B-600 type raw rubber; 5 parts potassium titanate whiskers, commercially available high-purity powder, with an average whisker length of 4μm and an aspect ratio of 15; 7.5 parts organosilicon additives, prepared in this embodiment; 14 parts reinforcing agent, commercially available N990 type carbon black; 2.7 parts vulcanizing agent, bisphenol A; 0.6 parts accelerator, composed of bisphenol AF and benzyltriphenylphosphine chloride in a weight ratio of 3:1; 1.8 parts activator, magnesium oxide.

[0045] Step S1: Mix fluororubber and silicone additives and add them to the open mill. Control the roller temperature to 55℃ and mill for 13 minutes. Add potassium carbonate whiskers, reinforcing agent, accelerator, activator and vulcanizing agent in sequence and mix for 30 minutes. Adjust the roller gap to 5mm and pass through the mill 10 times to obtain the composite rubber material.

[0046] Step S2: The composite rubber material is molded with the following parameters: temperature 165℃, pressure 11MPa, holding pressure for 10min, and then transferred to a vulcanizing kettle with the temperature controlled at 200℃ and the vulcanization time at 2.8h. The sealing ring material is obtained by vulcanization molding.

[0047] Example 4: Preparation of corrosion-resistant sealing ring material. The specific implementation process is as follows:

[0048] (1) Preparation of organosilicon additives

[0049] Step A1: Under nitrogen protection, premix single-ended hydrogen-containing silicone oil, allyl glycidyl ether, and toluene, then add platinum catalyst and mix. Heat to 80℃ and stir for 6 hours. The single-ended hydrogen-containing silicone oil is IOTA-611 type raw material, and the platinum catalyst is 5000ppm Castrol catalyst. The ratio of the hydrogen silane content of the single-ended hydrogen-containing silicone oil, allyl glycidyl ether, platinum catalyst, and toluene is 0.1mol:0.17mol:0.09g:350mL. After the reaction is completed, remove toluene by rotary evaporation under reduced pressure. After the substrate is cooled to room temperature, add deionized water to wash, centrifuge to separate the aqueous phase, and vacuum dry to obtain the ether-containing epoxy intermediate.

[0050] Step A2: Premix the ether-containing epoxy intermediate, tetrabutylammonium bromide, and acetone. Control the temperature in a water bath at 40°C, slowly add tris(2-aminoethyl)amine, and stir for 3 hours. Then, heat to 60°C and reflux for 40 minutes. The ratio of tris(2-aminoethyl)amine, epoxy group content of the ether-containing epoxy intermediate, and the amount of tetrabutylammonium bromide to acetone is 10 mmol: 38 mmol: 30 mg: 240 mL. After the reaction is complete, remove the acetone by rotary evaporation. Wash the substrate with ethanol and deionized water in sequence and dry to obtain the organosilicon additive.

[0051] (2) Preparation of sealing ring material

[0052] Ingredients: 100 parts fluororubber, Viton B-600 type raw rubber; 4.8 parts potassium titanate whiskers, commercially available high-purity powder, with an average whisker length of 3.2 μm and an aspect ratio of 10; 8.2 parts organosilicon additives, prepared in this embodiment; 13 parts reinforcing agent, commercially available N990 type carbon black; 2.9 parts vulcanizing agent, bisphenol A; 0.55 parts accelerator, composed of bisphenol AF and benzyltriphenylphosphine chloride in a weight ratio of 3:1; 1.7 parts activator, magnesium oxide.

[0053] Step S1: Mix fluororubber and silicone additives and add them to the open mill. Control the roller temperature to 55℃ and mill for 10 minutes. Add potassium carbonate whiskers, reinforcing agent, accelerator, activator and vulcanizing agent in sequence and mix for 30 minutes. Adjust the roller gap to 5mm and pass through the mill 10 times to obtain the composite rubber material.

[0054] Step S2: The composite rubber material is molded with the following parameters: temperature 170℃, pressure 10MPa, holding pressure for 10min, and then transferred to a vulcanizing kettle with the temperature controlled at 200℃ and the vulcanization time at 2.7h. The sealing ring material is obtained by vulcanization molding.

[0055] Comparative Example 1 was carried out in accordance with the process of Example 4, without the addition of potassium titanate whiskers and organosilicon additives.

[0056] Comparative Example 2, referring to the prior art and Example 4, uses an AFS®-LIM-2100 type fluorosilicone rubber composite to prepare a sealing ring, the specific components of which are as follows:

[0057] The mixture consists of 100 parts fluororubber, 4.8 parts potassium carbonate whiskers, 10 parts raw fluorosilicone rubber, 13 parts reinforcing agent, 3.5 parts vulcanizing agent, 0.6 parts accelerator, and 2.2 parts activator. The fluororubber and raw fluorosilicone rubber are mixed together, and the rest of the process is the same.

[0058] Samples were taken from the sealing ring material prepared above, and the resistance to swelling under various media was tested according to ASTM D471-2006 standard. The specific testing environments were: 92# gasoline (23℃, 168h), 0# diesel (23℃, 168h), L-HM22 hydraulic oil (80℃, 168h), and acetone (23℃, 168h). The specific test results are shown in Table 1.

[0059] Table 1. Test results of the swelling properties of the sealing ring

[0060]

[0061] As shown in Table 1, the sealing ring prepared in the example has significantly better anti-swelling performance than the comparative example, and maintains good stability in common swelling media.

[0062] The sealing rings prepared above were subjected to dynamic load corrosion tests using acetone as the corrosive medium. Loading: The sealing rings were immersed in acetone at 25% of their compression capacity for 24 hours. Unload: The sealing rings were removed and left to stand unloaded for 12 hours. After 100 cycles, compression set tests were conducted according to ASTM D395-2014. Seal leakage rate tests were performed according to ISO 3601-3:2005, using L-HM22 as the medium, at 20 MPa. Specific test results are shown in Table 2.

[0063] Table 2. Sealing performance test results of the sealing rings.

[0064]

[0065] As can be seen from the test results in Table 2, the sealing ring prepared in the example maintains stable sealing performance after dynamic load corrosion.

[0066] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0067] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A corrosion-resistant sealing ring material, characterized in that, The product comprises the following components by weight: 100 parts fluororubber, 4.2-5.5 parts potassium titanate whiskers, 6.8-9.3 parts organosilicon additives, 12-15 parts reinforcing agent, 2.4-3.1 parts vulcanizing agent, 0.5-0.7 parts accelerator, and 1.5-2 parts activator. The organosilicon additive is prepared by the following method: Step A1: Premix single-ended hydrogen-containing silicone oil, allyl glycidyl ether, and toluene under nitrogen protection, add platinum catalyst, mix, and heat to 75-90℃ and stir for 4.5-6.2 h to prepare an ether-containing epoxy intermediate. The ratio of the silane content of the single-ended hydrogen-containing silicone oil, the amount of allyl glycidyl ether, the amount of platinum catalyst, and the amount of toluene is 0.1mol: 0.15-0.18mol: 0.08-0.1g: 300-400mL. Step A2: Premix the ether-containing epoxy intermediate, tetrabutylammonium bromide, and acetone. Control the temperature in a water bath at 35-45℃, slowly add tris(2-aminoethyl)amine, and stir for 2-3 hours. Then, heat to 60℃ and reflux for 30-50 minutes to prepare an organosilicon additive. The ratio of tris(2-aminoethyl)amine, epoxy group content of the ether-containing epoxy intermediate, and amount of tetrabutylammonium bromide to acetone is 10mmol:35-40mmol:20-30mg:220-300mL.

2. The corrosion-resistant sealing ring material according to claim 1, characterized in that, The relative molecular weight of single-ended hydrogen-containing silicone oil is no higher than 3000.

3. The corrosion-resistant sealing ring material according to claim 1, characterized in that, The length of potassium titanate whiskers is controlled at 3-5 μm, and the aspect ratio is controlled at 10-15.

4. The corrosion-resistant sealing ring material according to claim 1, characterized in that, The accelerator is composed of bisphenol AF and benzyltriphenylphosphine chloride.

5. A method for preparing a corrosion-resistant sealing ring material according to any one of claims 1-4, characterized in that, Specifically: Step S1: Mix fluororubber and silicone additives and start milling. Add potassium titanate whiskers, reinforcing agent, accelerator, activator and vulcanizing agent in sequence and mix evenly. Cut into thin sheets to obtain composite rubber. Step S2: The composite rubber material is molded and then transferred into a vulcanizing kettle for vulcanization to obtain the sealing ring material.

6. The method for preparing a corrosion-resistant sealing ring material according to claim 5, characterized in that, The molding temperature is 160-170℃, the pressure is 10-12MPa, the vulcanization temperature is 190-200℃, and the vulcanization time is 2.5-3h.

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