High-performance fluororubber material and preparation method thereof

Abstract

The invention provides a high-performance fluororubber material and a preparation method thereof. The high-performance fluororubber material comprises the following components in parts by weight: 60-90 parts of fluororubber, 5-10 parts of modified ethylene propylene diene monomer, 0.5-3 parts of a plasticizer, 15-40 parts of a reinforcing agent, 1-5 parts of a vulcanizing agent and 0.5-2 parts of an acid acceptor. The prepared high-performance fluororubber material has the advantages of higher tensile strength, higher elongation at break, higher heat conductivity coefficient, lower compression set rate, high mechanical property, high heat conductivity, high elasticity, good aging resistance, difficulty in compressive deformation, high material reliability and long service life.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of rubber materials, and particularly relates to a high-performance fluororubber material and a preparation method thereof. BACKGROUND

[0002] Fluororubber has become the core material of key seals and pipelines in the automobile field due to its excellent high-temperature resistance, oil and medium resistance, and chemical stability. With the development of lightweight and high-power automobiles, more stringent requirements are put forward for the comprehensive performance of fluororubber.

[0003] Since the engine compartment temperature is maintained at 150-200 DEG C for a long time, the local temperature of the new energy automobile battery pack can reach more than 180 DEG C during operation, so it is urgent to have fluororubber with high thermal conductivity to quickly transfer heat and avoid local overheating to cause safety hazards. Moreover, due to the frequent stretching, bending deformation and the like of the pipeline and seal during automobile driving, fluororubber needs to have high strength to resist assembly stress and vibration impact, and low compression permanent deformation to ensure long-term sealing reliability. However, the current fluororubber material for automobiles still has technical bottlenecks in actual application, and it is difficult to simultaneously meet the synergistic requirements of high strength, high thermal conductivity, and low compression deformation.

[0004] At present, although some researches try to modify fluororubber by blending and adding fillers, it is often difficult to balance the above-mentioned performances. For example, simply adding high-thermal-conductivity fillers (such as metal oxides and nitrides) can improve the thermal conductivity of fluororubber material, but due to the uneven dispersion of fillers in the matrix, defects are formed, resulting in a significant decrease in mechanical properties.

[0005] Therefore, it has become a problem to be solved for those skilled in the art to develop a new type of fluororubber material which can simultaneously solve the contradictions between high strength, high elasticity, high thermal conductivity and low compression permanent deformation, and has excellent comprehensive performance. SUMMARY

[0006] The purpose of the present application is to provide a high-performance fluororubber material and a preparation method thereof to solve the problems raised in the background.

[0007] To achieve the above-mentioned purpose, the present application provides a high-performance fluororubber material, which comprises the following components in parts by weight: fluororubber 60-90 parts, modified EPDM 5-10 parts, plasticizer 0.5-3 parts, reinforcing agent 15-40 parts, vulcanizing agent 1-5 parts, and acid absorber 0.5-2 parts. The reinforcing agent is a composite of carbon black and modified silicon carbide.

[0008] As a further improvement, the synthesis of the modified silicon carbide comprises the following steps: The fluorine-containing silane is added into anhydrous ethanol to prepare a mixed solution, then the silicon carbide is added into the mixed solution to continue mixing, after mixing, post-treatment is performed to obtain the modified silicon carbide.

[0009] In order to make the hydrophobically modified silicon carbide have better compatibility, preferably, the fluorine-containing silane is heptadecafluorodecyltriethoxysilane.

[0010] As a further improvement, the particle size of the carbon black is 200-400 nm.

[0011] As a further improvement, the mass ratio of the carbon black to the modified silicon carbide is 3-6:1.

[0012] As a further improvement, the fluorine rubber is at least one of a vinylidene fluoride rubber, a tetrafluoroethylene-propylene rubber, and a perfluoroether rubber.

[0013] In order to have higher stability, preferably, the fluorine rubber is a perfluoroether rubber.

[0014] As a further improvement, the modified ethylene-propylene-diene rubber is a maleic anhydride modified ethylene-propylene-diene rubber.

[0015] As a further improvement, the plasticizer is at least one of methyl fluorosilicone oil, vinyl fluorosilicone oil, diethyl phthalate, and dioctyl phthalate.

[0016] In order to have higher elasticity, preferably, the plasticizer is methyl fluorosilicone oil.

[0017] As a further improvement, the vulcanizing agent is at least one of dicumyl peroxide, 4,4'-(hexafluoroisopropylidene) bisphenol, and 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane.

[0018] In order to have higher strength, preferably, the vulcanizing agent is 4,4'-(hexafluoroisopropylidene) bisphenol.

[0019] As a further improvement, the acid absorbent is at least one of calcium oxide, magnesium oxide, calcium hydroxide, and lead oxide.

[0020] In order to prevent corrosion of acidic gas in the processing process, preferably, the acid absorbent is magnesium oxide and calcium oxide.

[0021] The application also provides a preparation method of the high-performance fluorine rubber material, comprising the following steps: (1) Put the fluororubber, modified ethylene-propylene-diene rubber and plasticizer into the internal mixer, mix at 80-100℃ for 1-5min, then continue to add the reinforcing agent and acid absorber and mix for 1-5min, finally add the vulcanizing agent, and mix at 120-130℃ for 0.5-2min by using the plunger, then discharge, roll and sheet to obtain the mixed rubber; (2) The mixed rubber obtained in step (1) is vulcanized at 160-170℃ and 10-15MPa for 5-10min, and then kept at 170-190℃ for 2-6h to obtain the high-performance fluororubber material.

[0022] Compared with the prior art, the high-performance fluororubber material provided by the application has the advantages that: The high-performance fluororubber material provided by the application has high tensile strength, elongation at break and thermal conductivity, indicating that the mechanical properties are strong, the thermal conductivity is high, the anti-aging performance is good, the compression permanent set is low, indicating that the elasticity is high and the compression deformation is not easy to occur, and the material has high reliability and long service life. As a material with high strength and high thermal conductivity, the silicon carbide can be more matched with the surface energy of the fluororubber after being hydrophobically modified by fluorosilane, the intermolecular synergistic force can improve the compatibility with the fluororubber, the distribution is more uniform, and the mechanical properties, thermal conductivity and anti-aging performance of the fluororubber material can be effectively improved. DETAILED DESCRIPTION

[0023] The application will be described below in combination with specific embodiments. It should be noted that the following examples are only used to illustrate the application, and are not used to limit the application. Other combinations and various modifications within the concept of the application can be made without departing from the spirit or scope of the application.

[0024] In the following examples, the used compound monomers and related reagents except for the modified silicon carbide and KH-570 modified silicon carbide can be purchased from the market, wherein the perfluoroether rubber is purchased from Fuzhou Taipuda New Material Co., Ltd., and the model number is TPD-PFE-1000R; the maleic anhydride modified ethylene-propylene-diene rubber is purchased from Dongguan Shenghao Plastic Raw Material Co., Ltd., and the article number is 5541254; the methyl fluorosilicone oil is purchased from Wuhan Lanna Bai Pharmaceutical Chemical Co., Ltd., and the model number is NFS7100-G50; the carbon black is purchased from Shanxi Longfa Carbon Black Technology Co., Ltd., and the model number is N991; and the silicon carbide is purchased from Hubei Xiyu Hong Biological Medicine Technology Co., Ltd., and the model number is N / A.

[0025] The synthesis of the modified silicon carbide A comprises the following steps: A mixture solution was prepared by adding 2 g of heptadecafluorodecyltriethoxysilane into 200 mL of anhydrous ethanol, then 10 g of silicon carbide was added into the mixture and stirred for 2 h, and finally dried at 90 °C for 4 h to obtain modified silicon carbide A.

[0026] Synthesis of modified silicon carbide B, comprising the following steps: A mixture solution was prepared by adding 2 g of silane coupling agent KH-570 into 250 mL of anhydrous ethanol, then 10 g of silicon carbide was added into the mixture and stirred for 2 h, and finally dried at 100 °C for 4 h to obtain modified silicon carbide B.

[0027] The preparation method of examples 1-3 and comparative examples 1-3, comprising the following steps: (1) According to the weight fraction, the fluoroelastomer, the modified EPDM rubber and the plasticizer were put into the internal mixer, and mixed at 80 °C for 1 min, then the reinforcing agent and the acid absorber were added and mixed for 2 min, finally the vulcanizing agent was added, and the plunger was mixed at 120 °C for 1 min, then the material was discharged and rolled out to obtain the rubber compound; (2) The rubber compound obtained in step (1) was vulcanized at 160 °C and 12 MPa for 5 min, and then kept at 180 °C for 4 h to obtain the high-performance fluoroelastomer material.

[0028] The components and weight fractions used in examples 1-3 and comparative examples 1-3 are shown in Table 1 below: Table 1 The high-performance fluoroelastomer materials prepared in examples 1-3 and comparative examples 1-3 were tested for tensile strength, elongation at break, thermal conductivity and compression set, and the specific test methods were as follows: Tensile strength: according to GB / T 528-2009 standard; Elongation at break: according to GB / T 528-2009 standard; Thermal conductivity: according to GB / T 11205-2009 standard; Compression set: according to GB / T 7759.1-2015 standard, the compression device was used to compress the material at a compression rate of 25%, and the test conditions were 200 °C x 24 h, and the compression set was measured; The test results are shown in Table 2: Table 2 As can be seen from the test results of Example 1 and Comparative Example 1 in Table 2, compared with the high-performance fluororubber material prepared by using unmodified ethylene-propylene-diene rubber, the high-performance fluororubber material prepared by using the maleic anhydride modified ethylene-propylene-diene rubber has higher tensile strength, elongation at break and thermal conductivity, and lower compression set, indicating that the maleic anhydride modified ethylene-propylene-diene rubber can improve the compatibility with the fluororubber, and the composite with the remaining materials can further improve the mechanical properties and thermal conductivity of the fluororubber material, so that the material has good anti-aging performance, is not prone to compression deformation, has high reliability and long service life.

[0029] As can be seen from the test results of Example 1 and Comparative Examples 2-3 in Table 2, compared with the high-performance fluororubber material prepared by using carbon black and unmodified silicon carbide as reinforcing agents, or by using carbon black and KH-570 modified silicon carbide as reinforcing agents, the high-performance fluororubber material prepared by using carbon black and the modified silicon carbide composite prepared by the method of the present application as reinforcing agents has higher thermal conductivity, indicating that the addition of the modified silicon carbide of the present application can enhance the thermal conductivity of the high-performance fluororubber material, so that the material avoids local overheating and causes thermal aging, ensures long-term reliability of the material, prolongs the service life, and to some extent, can improve the tensile strength, elongation at break, and reduce the compression set, indicating that the mechanical properties are good, the strength is high, the elasticity is good, and the adaptability is strong.

[0030] As can be seen from the test results of Examples 1-3, the high-performance fluororubber material prepared by the preparation method of the present application has higher tensile strength, elongation at break and thermal conductivity, and lower compression set, indicating that the mechanical properties are strong, the thermal conductivity is high, and the compression deformation is not prone to occur, and as can be seen from the test results of Examples 1-2 and Example 3, when the mass ratio of carbon black to modified silicon carbide is within a suitable range, the fluororubber material prepared has better strength, thermal conductivity, elasticity and other properties.

[0031] The above embodiments only serve to illustrate the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application, and any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A high-performance fluororubber material, characterized in that, The high-performance fluororubber material comprises the following components in parts by weight: 60-90 parts fluororubber, 5-10 parts modified EPDM rubber, 0.5-3 parts plasticizer, 15-40 parts reinforcing agent, 1-5 parts vulcanizing agent, and 0.5-2 parts acid scavenger. The reinforcing agent is a composite of carbon black and modified silicon carbide.

2. The high-performance fluororubber material according to claim 1, characterized in that, The synthesis of the modified silicon carbide includes the following steps: Fluorosilane was added to anhydrous ethanol to prepare a mixed solution. Then, silicon carbide was added to the mixed solution and the mixture was stirred. After stirring, the solution was post-treated to obtain modified silicon carbide.

3. The high-performance fluororubber material according to claim 1, characterized in that, The carbon black has a particle size of 200-400 nm.

4. The high-performance fluororubber material according to claim 1, characterized in that, The mass ratio of carbon black to modified silicon carbide is 3-6:

1.

5. The high-performance fluororubber material according to claim 1, characterized in that, The fluororubber is at least one of polyvinylidene fluoride rubber, tetrapropylene fluororubber, and perfluoroether rubber.

6. The high-performance fluororubber material according to claim 1, characterized in that, The modified EPDM rubber is maleic anhydride modified EPDM rubber.

7. The high-performance fluororubber material according to claim 1, characterized in that, The plasticizer is at least one of methyl fluorosilicone oil, vinyl fluorosilicone oil, diethyl phthalate, and dioctyl phthalate.

8. The high-performance fluororubber material according to claim 1, characterized in that, The vulcanizing agent is at least one of dicumyl peroxide, 4,4'-(hexafluoroisopropylidene)bisphenol, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

9. The high-performance fluororubber material according to claim 1, characterized in that, The acid absorbent is at least one of calcium oxide, magnesium oxide, calcium hydroxide, and lead oxide.

10. A method for preparing a high-performance fluororubber material according to any one of claims 1-9, comprising the following steps: (1) Add fluororubber, modified EPDM rubber and plasticizer into a mixer and mix at 80-100℃ for 1-5 minutes. Then add reinforcing agent and acid absorber and mix for 1-5 minutes. Finally add vulcanizing agent and mix at 120-130℃ with a hammer for 0.5-2 minutes. Discharge the material and pass it through rollers and sheet to obtain the compound rubber. (2) The compound obtained in step (1) is vulcanized at 160-170℃ and 10-15MPa for 5-10 minutes, and then kept at 170-190℃ for 2-6 hours to obtain high-performance fluororubber material.

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