Lunar vehicle tire tread rubber composition, mixing method thereof and tire

Abstract

The invention relates to the technical field of tire rubber manufacturing, and discloses a lunar vehicle tire tread rubber composition, a mixing method thereof and a tire. The rubber composition is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: 25-75 parts by weight of silicone rubber, 10-45 parts by weight of fluororubber, 15-30 parts by weight of ethylene propylene diene monomer, 30-50 parts by weight of carbon black, 2-8 parts by weight of an active agent and 2-4 parts by weight of an anti-aging agent. The tread rubber composition has excellent weather resistance and high and low temperature resistance, can obviously improve the high and low temperature resistance, and ensures that the tread of the lunar rover tire does not generate large deformation quantity at low temperature (as low as-100 DEG C) and high temperature (as high as 140 DEG C).

Description

Technical Field

[0001] The invention relates to the technical field of tire rubber manufacturing, and in particular to a lunar rover tire tread rubber composition and a mixing method thereof, and a tire. Background Art

[0002] The National Aeronautics and Space Administration (NASA) developed ground vehicles to support long-distance lunar exploration and the development of a lunar base. These vehicles are heavier and travel greater distances than the Lunar Roving Vehicle (LRV) developed by the Apollo program in the late 1960s. Therefore, new tires are needed to support up to ten times the weight and up to a hundred times the distance than the tires used on the Apollo LRV, requiring operating characteristics similar to those of cars used on Earth. However, traditional rubber pneumatic tires do not work satisfactorily in space. Rubber characteristics vary significantly between low temperatures in the shadow (as low as -100°C) and high temperatures in the sun (up to 140°C), and rubber exposed to direct solar radiation without atmospheric protection degrades.

[0003] The Chinese invention patent (publication number: CN117511227A, publication date: 2024.02.06) discloses a weather-resistant and high-low temperature-resistant tire silicone rubber composition. The raw materials of the silicone rubber composition include the following components based on 100 parts by weight of rubber: 25-65 parts by weight of silicone rubber, 35-75 parts by weight of modified low-cis polybutadiene rubber, 30-50 parts by weight of carbon black, 2-6 parts by weight of active agent, 2-4 parts by weight of antioxidant, and also include appropriate amounts of accelerators and vulcanizers; the silicone rubber is methyl vinyl silicone rubber 110-5. The silicone rubber composition of the invention has certain weather resistance and high and low temperature resistance, and can be used to prepare lunar rover tires to ensure that the tire tread will not undergo large deformation under low temperature (as low as -100°C) and high temperature (up to 140°C) conditions. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a lunar rover tire tread rubber composition and a mixing method thereof, and a tire. The lunar rover tire prepared using the tread rubber composition can withstand lunar temperature changes and solar radiation, operate in a vacuum, and does not require air for load support.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: A lunar rover tire tread rubber composition, wherein the rubber composition is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: Silicone rubber 25-75 parts by weight, Fluororubber 10-45 parts by weight, 15-30 parts by weight of EPDM rubber, 30-50 parts by weight of carbon black, 2-8 parts by weight of active agent, Antiaging agent 2-4 parts by weight.

[0006] Preferably, the rubber composition is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: Silicone rubber 30-70 parts by weight, 10-40 parts by weight of fluororubber, 20-25 parts by weight of EPDM rubber, 30-50 parts by weight of carbon black, 2-8 parts by weight of active agent, 2-4 parts by weight of antioxidant, The accelerator is 0.5-3 parts by weight, The vulcanizing agent is 2-6 parts by weight.

[0007] Preferably, the fluororubber is a ternary copolymer of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene, wherein the content of vinylidene fluoride is 65-70%, and the contents of tetrafluoroethylene and hexafluoropropylene are both 15-17%.

[0008] Preferably, the EPDM rubber is a terpolymer of ethylene, propylene and a third monomer, wherein the content of ethylene and propylene are both 40-60%, and the content of the third monomer is 7-17%.

[0009] Preferably, the carbon black is one or more of N330, N375, N550, and N660; preferably, the carbon black is N375.

[0010] Preferably, the active agent is one or more of zinc oxide, stearic acid, and trimethylolpropane tris(3-mercaptopropionate), wherein zinc oxide is 2-5 parts by weight, stearic acid is 2-4 parts by weight, and trimethylolpropane tris(3-mercaptopropionate) is 1-3 parts by weight.

[0011] Preferably, the antioxidant is antioxidant TMQ and / or antioxidant 6PPD, wherein the antioxidant TMQ is 1-3 parts by weight and the antioxidant 6PPD is 1-3 parts by weight.

[0012] Preferably, the accelerator is accelerator CZ and / or accelerator TBzTD, wherein the accelerator CZ is 1-2 parts by weight and the accelerator TBzTD is 0.5-1.5 parts by weight.

[0013] Furthermore, the present invention also provides a mixing method for the tread rubber composition, comprising the following steps: 1) Mixing: Use a tangent type internal mixer, set the internal mixer rotor speed to 40-55rpm, the upper bolt pressure to 4.2±0.2bar, and the internal mixer cooling water temperature to 25-40℃; a. Add all silicone rubber, fluororubber and EPDM rubber, press the top bolt and keep it for 10-20 seconds; b. Raise the top bolt, add carbon black, activator and antioxidant, and press the top bolt to raise the temperature of the rubber to 100-110℃; c. Raise the top bolt and hold for 6-10 seconds; d. Press the top bolt to raise the temperature of the rubber material to 120-130℃, raise the top bolt, discharge the rubber and press it into sheets to obtain the masterbatch; 2) Final refining and sulfur addition: Use a tangent type internal mixer, set the internal mixer rotor speed to 15-30rpm, the upper bolt pressure to 4.2±0.2bar, and the internal mixer cooling water temperature to 25-40℃; a. Add the mixed masterbatch, vulcanizer and accelerator, and press the top bolt to raise the temperature of the rubber to 70-80℃; b. Raise the top bolt and hold for 6-10 seconds; c. Press the top bolt to raise the temperature of the rubber to 80-90℃; d. Raise the top bolt and hold for 6-8 seconds; e. Press the top bolt to raise the temperature of the rubber material to 90-95℃, discharge the rubber and press it into sheets.

[0014] Furthermore, the present invention also provides a lunar rover tire, wherein the non-tread portion of the tire is made of metal, and the tread is prepared by vulcanizing the tread rubber composition.

[0015] The tread rubber composition provided by the present invention has excellent weather resistance and high and low temperature resistance, and can significantly improve the high and low temperature resistance, ensuring that the tread of the lunar rover tire will not undergo large deformation at low temperatures (as low as -100°C) and high temperatures (as high as 140°C). DETAILED DESCRIPTION

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

[0017] The formulations of the embodiments, comparative examples and reference examples are shown in Table 1.

[0018] Table 1 Reference ratio Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 Example 4 Silicone rubber*1 100 / / 80 60 40 50 60 70 Fluororubber*2 / 100 / / 40 40 30 20 10 EPDM*3 / / 100 20 / 20 20 20 20 N375 40 40 40 40 40 40 40 40 40 Zinc Oxide 3 3 3 3 3 3 3 3 3 Stearic acid 2 2 2 2 2 2 2 2 2 Trimethylolpropane tris(3-mercaptopropionate)*4 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Antioxidant TMQ 2 2 2 2 2 2 2 2 2 Antioxidant 6PPD 2 2 2 2 2 2 2 2 2 Accelerator CZ 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Accelerator TBzTD 1 1 1 1 1 1 1 1 1 sulfur 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 Source of raw materials: 1. Silicone rubber 107, a product of Shenzhen Jingyi Chemical Co., Ltd. 2. Fluororubber 246, a product of LG, South Korea; 3. EPDM rubber KEP350, a product of Kumho, South Korea. 4. Trimethylolpropane tris(3-mercaptopropionate), a product of Shanghai Yuanye Biotechnology Co., Ltd.; The rest of the products are commercially available.

[0019] Embodiment The mixing method is as follows: 1) Mixing: Use a tangent type internal mixer, set the internal mixer rotor speed to 50 rpm, the upper bolt pressure to 4.2 bar, and the internal mixer cooling water temperature to 30 °C; a. Add all silicone rubber, fluororubber and EPDM rubber, press the top bolt and keep it for 15 seconds; b. Raise the top bolt, add carbon black, activator and antioxidant, and press the top bolt to raise the temperature of the rubber to 105℃; c. Raise the top bolt and hold for 8 seconds; d. Press the top bolt to raise the temperature of the rubber to 125°C, raise the top bolt, discharge the rubber and press it into sheets to obtain the masterbatch; 2) Final refining and sulfur addition: Use a tangent type internal mixer, set the internal mixer rotor speed to 25rpm, the upper bolt pressure to 4.2bar, and the internal mixer cooling water temperature to 30℃; a. Add the mixed masterbatch, vulcanizer and accelerator, and press the top bolt to raise the temperature of the rubber to 75℃; b. Raise the top bolt and hold for 8 seconds; c. Press the top bolt to raise the temperature of the rubber to 85°C; d. Raise the top bolt and hold for 7 seconds; e. Press the top bolt to raise the temperature of the rubber to 95℃, and then discharge the rubber and press it into sheets.

[0020] The mixing method of comparative example and reference example is the same as that of the embodiment.

[0021] The tread rubber compositions obtained from the reference examples, comparative examples, and examples were subjected to aging tests. The results are shown in Table 2. The data of the examples and comparative examples were processed with the reference example performance as 100% for each performance.

[0022] Aging tests are carried out at different temperatures, and the tensile strength and elongation at break are tested using a tensile testing machine. The larger the value, the greater the tensile strength and the elongation at break.

[0023] Low temperature tensile test: vulcanization condition 160℃×15min, aging condition: -100℃*7days.

[0024] High temperature tensile test: vulcanization condition 160℃×15min, aging condition: first -100℃*7 days, then 140℃*7 days.

[0025] Table 2 The above test results show that Example 1 is the best example, which can significantly improve the physical tensile properties of the rubber composition under low and high temperature conditions. The physical tensile properties of the rubber composition provided in the example at low and high temperatures are better than those of the rubber composition of the reference example. Through the comparative examples and examples, it can be seen that the scientific proportioning of silicone rubber, fluororubber and EPDM rubber, as well as the synergistic effect of fluororubber and EPDM rubber, can effectively improve the weather resistance and high and low temperature resistance of the rubber composition, and the physical tensile properties at low and high temperatures are improved.

[0026] The above is a description of the embodiments of the present invention. Through the above description of the disclosed embodiments, professionals and technicians in the field can implement or use the present invention. Various modifications to these embodiments will be apparent to professionals and technicians in the field. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown in this article, but will conform to the widest range consistent with the principles and novelties disclosed herein.

Claims

1. A lunar rover tire tread rubber composition, characterized in that: The rubber composition is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: Silicone rubber 25-75 parts by weight, Fluororubber 10-45 parts by weight, 15-30 parts by weight of EPDM rubber, 30-50 parts by weight of carbon black, 2-8 parts by weight of active agent, Antiaging agent 2-4 parts by weight.

2. The tread rubber composition according to claim 1, characterized in that: The rubber composition is prepared by mixing the following raw materials based on 100 parts by weight of raw rubber: Silicone rubber 30-70 parts by weight, 10-40 parts by weight of fluororubber, 20-25 parts by weight of EPDM rubber, 30-50 parts by weight of carbon black, 2-8 parts by weight of active agent, 2-4 parts by weight of antioxidant, The accelerator is 0.5-3 parts by weight, The vulcanizing agent is 2-6 parts by weight.

3. The tread rubber composition according to claim 1 or 2, characterized in that: The fluororubber is a ternary copolymer of vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene, wherein the content of vinylidene fluoride is 65-70%, and the contents of tetrafluoroethylene and hexafluoropropylene are both 15-17%.

4. The tread rubber composition according to claim 1 or 2, characterized in that: The EPDM rubber is a terpolymer of ethylene, propylene and a third monomer, wherein the content of ethylene and propylene is 40-60% each, and the content of the third monomer is 7-17%.

5. The tread rubber composition according to claim 1 or 2, characterized in that: The carbon black is one or more of N330, N375, N550, and N660; preferably, the carbon black is N375.

6. The tread rubber composition according to claim 1 or 2, characterized in that: The active agent is one or more of zinc oxide, stearic acid, and trimethylolpropane tris(3-mercaptopropionate), wherein zinc oxide is 2-5 parts by weight, stearic acid is 2-4 parts by weight, and trimethylolpropane tris(3-mercaptopropionate) is 1-3 parts by weight.

7. The tread rubber composition according to claim 1 or 2, characterized in that: The antioxidant is antioxidant TMQ and / or antioxidant 6PPD, wherein the antioxidant TMQ is 1-3 parts by weight and the antioxidant 6PPD is 1-3 parts by weight.

8. The tread rubber composition according to claim 1 or 2, characterized in that: The accelerator is accelerator CZ and / or accelerator TBzTD, wherein the accelerator CZ is 1-2 parts by weight and the accelerator TBzTD is 0.5-1.5 parts by weight.

9. The mixing method of the tread rubber composition according to any one of claims 1 to 8, characterized in that: The following steps are involved: 1) Mixing: Use a tangent type internal mixer, set the internal mixer rotor speed to 40-55rpm, the upper bolt pressure to 4.2±0.2bar, and the internal mixer cooling water temperature to 25-40℃; a. Add all silicone rubber, fluororubber and EPDM rubber, press the top bolt and keep it for 10-20 seconds; b. Raise the top bolt, add carbon black, activator and antioxidant, and press the top bolt to raise the temperature of the rubber to 100-110℃; c. Raise the top bolt, add plasticizer, and keep it for 6-10 seconds; d. Press the top bolt to raise the temperature of the rubber material to 120-130℃, raise the top bolt, discharge the rubber and press it into sheets to obtain the masterbatch; 2) Final refining and sulfur addition: Use a tangent type internal mixer, set the internal mixer rotor speed to 15-30rpm, the upper bolt pressure to 4.2±0.2bar, and the internal mixer cooling water temperature to 25-40℃; a. Add the mixed masterbatch, vulcanizer and accelerator, and press the top bolt to raise the temperature of the rubber to 70-80℃; b. Raise the top bolt and hold for 6-10 seconds; c. Press the top bolt to raise the temperature of the rubber to 80-90℃; d. Raise the top bolt and hold for 6-8 seconds; e. Press the top bolt to raise the temperature of the rubber material to 90-95℃, discharge the rubber and press it into sheets.

10. A lunar rover tire, characterized in that: The non-tread part of the tire is made of metal, and the tread is prepared by vulcanizing the tread rubber composition according to any one of claims 1 to 8.

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