High-wear-resistance fluorinated silicone rubber compound as well as preparation method and application thereof

Abstract

The invention provides a high-wear-resistance fluorinated silicone rubber compound as well as a preparation method and application thereof, and belongs to the technical field of special rubber materials. Fluorine-containing polyimide modified fluorosilicone rubber is adopted to develop a high-wear-resistance fluorosilicone rubber compound, and a fluorine-containing polyimide chain segment has extremely high rigidity and self-lubricating property and is dispersed in a rubber matrix to form a rigid micro-area, so that the wear resistance can be greatly improved and is far superior to that of conventional fluorosilicone rubber; meanwhile, the rubber compound is excellent and stable in strength. The preparation process is simple, easy to operate and easy to industrialize, and has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of special rubber materials technology, specifically relating to a high wear-resistant fluorosilicone rubber compound, its preparation method, and its application. Background Technology

[0002] Fluorosilicone rubber, with its combination of the excellent high and low temperature resistance and low-temperature flexibility of silicone rubber and the outstanding oil resistance, solvent resistance and chemical corrosion resistance of fluororubber, plays an irreplaceable role in key sealing components, dynamic parts and special protective products in high-end fields such as aerospace, automotive industry, petrochemical industry and semiconductor manufacturing.

[0003] Especially in my country, with the rapid development of high-end equipment manufacturing, new energy vehicles, and the semiconductor industry, and the ever-increasing demands for equipment reliability and lifespan, the market demand for high-performance, long-life, wear-resistant sealing materials has experienced explosive growth. However, under dynamic friction or harsh wear conditions (such as high-speed rotating seals, reciprocating motion components, and environments containing abrasive particles), the wear resistance of traditional fluorosilicone rubber often fails to meet the increasingly stringent usage requirements, leading to premature seal failure, shortened lifespan, and consequently, equipment leakage, performance degradation, and even safety accidents. This has become a key bottleneck restricting its application in broader or higher-performance scenarios. Therefore, developing a fluorosilicone rubber with significantly improved wear resistance has significant industrial application value and market prospects.

[0004] Existing methods for improving the wear resistance of fluorosilicone rubber have many drawbacks. They generally rely on complex organic modification processes (such as multi-step polymer synthesis, silane coupling agent treatment, plasma treatment, etc.) or the introduction of various special fillers (such as polytetrafluoroethylene, fluorinated graphene, modified carbon nanotubes, molybdenum disulfide / zirconium phosphate, etc.), resulting in cumbersome overall preparation processes, high operational difficulty, and high energy consumption (such as long-term high-temperature mixing), significantly increasing the complexity and cost of industrial production. At the same time, inorganic fillers at high addition levels can easily lead to a sharp increase in the hardness of the rubber compound, loss of elasticity, and deterioration of processability; fluoropolymers such as PTFE have poor compatibility with the fluorosilicone rubber matrix, easily causing phase separation, and uneven dispersion can actually reduce mechanical strength; existing modifiers have limited improvement in wear resistance and are difficult to apply to the long-term stability and uniformity of material properties.

[0005] Patent application CN106380752A discloses an ultra-high wear-resistant fluorinated elastomer, which significantly improves wear resistance and service life by adding high wear-resistant inorganic organic materials zirconium dioxide and thermoplastic polyimide, self-lubricating material polytetrafluoroethylene micro powder, and thermally conductive and wear-resistant additives carbon nanotubes or graphene to the composition of the fluorinated elastomer and performing one or two vulcanization processes. However, the fluorinated elastomer in patent application CN106380752A has the following problems: (1) Poor wear resistance: its fluorinated elastomer relies on the physical mixing of multiple fillers (zirconia + thermoplastic polyimide + polytetrafluoroethylene micro powder + thermally conductive and wear-resistant additives carbon nanotubes / graphene, etc.), which has poor multiphase interface compatibility and is prone to phase separation, and the high filler content sacrifices elasticity; (2) Poor elongation at break (180%~280%), which needs to be further improved. Summary of the Invention

[0006] In view of the problems existing in the prior art, the purpose of this invention is to provide a highly wear-resistant fluorosilicone rubber compound, its preparation method and application.

[0007] This invention provides a fluorosilicone rubber compound comprising the following raw materials in parts by weight: 100 parts of fluorosilicone rubber raw rubber, 5-15 parts of fluorinated polyimide prepolymer, 25-40 parts of filler, 3-5 parts of structure control agent, 0.8-1.2 parts of vulcanizing agent, and 0.2-1 parts of vulcanization accelerator.

[0008] Furthermore, the fluorosilicone rubber compound comprises the following raw materials in parts by weight: 100 parts of fluorosilicone rubber raw rubber, 5-15 parts of fluorinated polyimide prepolymer, 30-40 parts of filler, 3 parts of structure control agent, 1 part of vulcanizing agent, and 0.2-0.5 parts of vulcanization accelerator.

[0009] Furthermore, the fluorosilicone rubber compound comprises the following raw materials in parts by weight: 100 parts of fluorosilicone rubber raw rubber, 12 parts of fluorinated polyimide prepolymer, 30 parts of filler, 3 parts of structure control agent, 1 part of vulcanizing agent, and 0.5 parts of vulcanization accelerator.

[0010] Furthermore, the filler is any one or a mixture of any of the following: diatomaceous earth, silica powder, and silica.

[0011] The structure control agent is either hydroxyl fluorosilicone oil or hydroxyl silicone oil;

[0012] The vulcanizing agent is bis-2,5-(2,5-dimethyl-2,5-bis(tert-butadiene)hexane);

[0013] The vulcanization accelerator is any one or a mixture of any of the following: triallyl isocyanurate and trimethylolpropane trimethacrylate.

[0014] Furthermore, the preparation method of the fluorinated polyimide prepolymer includes the following steps: reacting hexafluorodianhydride with 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl to obtain a polyamic acid solution; adding maleic anhydride to the system and continuing the reaction to obtain the fluorinated polyimide prepolymer.

[0015] Further, the molar ratio of hexafluorodianhydride, 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl and maleic anhydride is 1:1:0.1-0.15; the solvent for the reaction is an organic solvent; the reaction temperature is 10-40°C and the time is 2-6 hours; the temperature for further reaction is 40-60°C and the time is 1-3 hours.

[0016] The present invention also provides a method for preparing the above-mentioned fluorosilicone rubber compound, the method comprising the following steps: mixing fluorosilicone rubber raw rubber and fluorinated polyimide prepolymer, heating to remove solvent, then mixing with filler, structure control agent, vulcanizing agent and vulcanization accelerator, heating and vacuuming, placing and then re-mixing, vulcanizing, to obtain the final product.

[0017] Furthermore, the mixing temperature is 25℃~60℃, and the time is 0.5~2h; the heating and vacuuming temperature is 60℃~100℃; the heating and vacuuming time is 0.1~1h; the placement time is 20~30h; and the number of re-mixing passes is 5~10.

[0018] Furthermore, the vulcanization is divided into a first-stage vulcanization and a second-stage vulcanization; the temperature of the first-stage vulcanization is 160℃~180℃, and the time is 5~15min; the temperature of the second-stage vulcanization is 190℃~210℃, and the time is 2~6h.

[0019] The present invention also provides the use of the above-mentioned fluorosilicone rubber compound in the preparation of fluororubber products.

[0020] The present invention has achieved the following beneficial effects:

[0021] (1) This invention introduces a specific structure of fluorinated polyimide at the molecular level to achieve entanglement with the molecular chain of fluorosilicone rubber and improve the wear resistance of fluorosilicone rubber. This solves the problem that untreated fluorosilicone rubber has weak wear resistance and cannot maintain its performance under harsh conditions, which poses a huge safety hazard.

[0022] (2) Compared with the patent application CN106380752A, the wear resistance of the fluorosilicone rubber compound of the present invention is significantly better. The present invention uses a synthesized fluorinated polyimide prepolymer (F-PI) to modify the fluorosilicone rubber matrix through molecular entanglement to form a rigid micro-region reinforcement structure, which not only takes into account self-lubrication and rigidity and avoids filler agglomeration, but also improves wear resistance while maintaining high elasticity.

[0023] (3) Compared with patent application CN106380752A, the elongation at break of the fluorosilicone rubber compound of the present invention is significantly better. The elongation at break of patent application CN106380752A is 180% to 280%, while the elongation at break of the fluorosilicone rubber compound of the present invention is 426% to 516%.

[0024] This invention develops a highly wear-resistant fluorosilicone rubber compound using fluorinated polyimide-modified fluorosilicone. The fluorinated polyimide segments possess extremely high rigidity and self-lubricating properties, and their dispersion in the rubber matrix forms rigid microdomains, significantly improving wear resistance far superior to conventional fluorosilicone rubbers. Simultaneously, this compound exhibits excellent and stable strength. The preparation process of this invention is simple, easy to operate, and readily industrialized, demonstrating promising application prospects.

[0025] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention.

[0026] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention. Detailed Implementation

[0027] The raw materials and equipment used in this invention are all known products, obtained by purchasing commercially available products.

[0028] In this embodiment of the invention, "room temperature" refers to 25±5℃.

[0029] The materials used in the embodiments of this invention are as follows:

[0030] Fluorosilicone rubber raw material: purchased from Fuzhou Aluda New Material Co., Ltd., model / specification ALD-D-F100.

[0031] 2,5-Dimethyl-2,5-bis(tert-butylperoxy)hexane.

[0032] TAIC: Triallyl isocyanurate.

[0033] Silica: Purchased from Cabot, model / specification D2150.

[0034] Hydroxyfluorosilicone oil: Purchased from Guangzhou Fuze New Materials Co., Ltd., model / specification DFO-MF-50.

[0035] Example 1: Fluorosilicone rubber compound

[0036] This embodiment provides a fluorosilicone rubber compound, comprising the following raw materials in parts by weight:

[0037] Fluorosilicone rubber raw material 100 copies Fluorinated polyimide prepolymer 5 copies Double 25 1 copy TAIC 0.5 copies precipitate 30 copies Hydroxyfluorosilicone oil 3 copies

[0038] The preparation method of fluorinated polyimide prepolymer (F-PI) is as follows:

[0039] Equimolar amounts of hexafluorodianhydride (6FDA) and 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB) were dissolved in anhydrous DMF solvent and reacted for 4 hours to generate a polyamic acid solution. Subsequently, the temperature was raised to 50°C, and maleic anhydride (10%–15% of the molar amount of TFDB) was added dropwise to the system. The reaction was continued for 2 hours to end-cap the polyimide, yielding a fluorinated polyimide prepolymer containing double bonds (F-PI).

[0040] The preparation method of fluorosilicone rubber compound is as follows:

[0041] In a kneader, the fluorinated polyimide prepolymer solution and fluorosilicone rubber raw rubber are first mixed and sheared at a mass ratio of 5:100 to form a homogeneous blend. Then, the DMF is removed at high temperature to obtain fluorinated polyimide modified fluorosilicone. This is then added to the kneader along with silica, hydroxyl fluorosilicone oil, bis(2,5-dimethyl)methacrylate (DDM) and TAIC for 1 hour. The kneading temperature is 25℃~60℃, and the speed is controlled at 25~34 r / min. After mixing, the mixture is vacuumed at 80℃ for 0.5 hours, then left to stand at room temperature for 24 hours. Finally, it is thin-passed through a rolling mill 5~10 times. The vulcanization is carried out according to the following steps: first stage vulcanization at 170℃ / 10min, second stage vulcanization at 200℃ / 4h.

[0042] Example 2: Fluorosilicone rubber compound

[0043] This embodiment provides a fluorosilicone rubber compound, comprising the following raw materials in parts by weight:

[0044] Fluorosilicone rubber raw material 100 copies Fluorinated polyimide prepolymer 8 copies Double 25 1 copy TAIC 0.2 copies precipitate 30 copies Hydroxyfluorosilicone oil 3 copies

[0045] The preparation method of the fluorinated polyimide prepolymer and the fluorosilicone rubber compound is as described in Example 1.

[0046] Example 3: Fluorosilicone rubber compound

[0047] This embodiment provides a fluorosilicone rubber compound, comprising the following raw materials in parts by weight:

[0048] Fluorosilicone rubber raw material 100 copies Fluorinated polyimide prepolymer 12 copies Double 25 1 copy TAIC 0.5 copies precipitate 30 copies Hydroxyfluorosilicone oil 3 copies

[0049] The preparation method of the fluorinated polyimide prepolymer and the fluorosilicone rubber compound is as described in Example 1.

[0050] Example 4: Fluorosilicone rubber compound

[0051] This embodiment provides a fluorosilicone rubber compound, comprising the following raw materials in parts by weight:

[0052] Fluorosilicone rubber raw material 100 copies Fluorinated polyimide prepolymer 15 copies Double 25 1 copy TAIC 0.2 copies precipitate 30 copies Hydroxyfluorosilicone oil 3 copies

[0053] The preparation method of the fluorinated polyimide prepolymer and the fluorosilicone rubber compound is as described in Example 1.

[0054] Example 5: Fluorosilicone rubber compound

[0055] This embodiment provides a fluorosilicone rubber compound, comprising the following raw materials in parts by weight:

[0056] Fluorosilicone rubber raw material 100 copies Fluorinated polyimide prepolymer 8 copies Double 25 1 copy TAIC 0.2 copies precipitate 40 copies Hydroxyfluorosilicone oil 3 copies

[0057] The preparation method of the fluorinated polyimide prepolymer and the fluorosilicone rubber compound is as described in Example 1.

[0058] The following section describes the preparation of comparative samples.

[0059] Comparative Example 1: Fluorosilicone Rubber Compound

[0060] This comparative example provides a fluorosilicone rubber compound, comprising the following raw materials in parts by weight:

[0061] Fluorosilicone rubber raw material 100 copies Double 25 1 copy TAIC 0.2 copies precipitate 30 copies Hydroxyfluorosilicone oil 3 copies

[0062] The preparation method of fluorosilicone rubber compound is as follows:

[0063] Add the raw fluorosilicone rubber, silica, hydroxyl fluorosilicone oil, bis(2,5)5 and TAIC to a kneader and mix for 1 hour. The mixing temperature is 25℃~60℃ and the speed is controlled at 25~34r / min. After mixing, vacuum at 80℃ for 0.5 hours, then let it stand at room temperature for 24 hours. Then, perform a thin pass re-rolling on an open mill 5~10 times. Vulcanization is carried out according to the following procedure: first stage vulcanization at 170℃ / 10min, second stage vulcanization at 200℃ / 4h.

[0064] Comparative Example 2: Fluorosilicone Rubber Compound

[0065] This comparative example provides a fluorosilicone rubber compound, comprising the following raw materials in parts by weight:

[0066] Fluorosilicone rubber raw material 100 copies Double 25 1 copy TAIC 0.2 copies precipitate 40 copies Hydroxyfluorosilicone oil 3 copies

[0067] The preparation method of fluorosilicone rubber compound is as described in Comparative Example 1.

[0068] The following experimental examples demonstrate the beneficial effects of the present invention.

[0069] Experimental Example 1: Performance Testing of Fluorosilicone Rubber Compound

[0070] 1. Experimental Methods

[0071] The hardness, mechanical properties, and Akron abrasion of the fluorosilicone rubber compounds of Examples 1-5 and Comparative Examples 1-2 were tested using the national standard methods GB / T531.1-2008, GB / T 528-2009, and GB / T1689-2014.

[0072] 2. Experimental Results

[0073] The specific experimental results are as follows:

[0074] Table 1. Performance Comparison of Fluorosilicone Rubber Compounds

[0075]

[0076] As shown in Table 1, compared with Comparative Examples 1-2, the fluorosilicone rubber compound prepared by the method of the present invention (Examples 1-5) can significantly improve the wear resistance of the rubber while maintaining excellent mechanical properties, among which Example 3 has the best overall performance.

[0077] In summary, this invention provides a highly wear-resistant fluorosilicone rubber compound, its preparation method, and its applications. This invention utilizes fluorinated polyimide-modified fluorosilicone to develop a highly wear-resistant fluorosilicone rubber compound. The fluorinated polyimide segments possess extremely high rigidity and self-lubricating properties, and their dispersion in the rubber matrix forms rigid microdomains, significantly improving wear resistance, far exceeding that of conventional fluorosilicone rubbers. Simultaneously, this compound exhibits excellent and stable strength. The preparation process of this invention is simple, easy to operate, and readily industrialized, demonstrating promising application prospects.

Claims

1. A fluorosilicone rubber compound, characterized in that, It comprises the following raw materials in parts by weight: 100 parts of fluorosilicone rubber raw rubber, 5-15 parts of fluorinated polyimide prepolymer, 25-40 parts of filler, 3-5 parts of structure control agent, 0.8-1.2 parts of vulcanizing agent, and 0.2-1 parts of vulcanization accelerator.

2. The fluorosilicone rubber compound according to claim 1, characterized in that, The fluorosilicone rubber compound comprises the following raw materials in parts by weight: 100 parts of fluorosilicone rubber raw rubber, 5-15 parts of fluorinated polyimide prepolymer, 30-40 parts of filler, 3 parts of structure control agent, 1 part of vulcanizing agent, and 0.2-0.5 parts of vulcanization accelerator.

3. The fluorosilicone rubber compound according to claim 2, characterized in that, The fluorosilicone rubber compound comprises the following raw materials in parts by weight: 100 parts of fluorosilicone rubber raw rubber, 12 parts of fluorinated polyimide prepolymer, 30 parts of filler, 3 parts of structure control agent, 1 part of vulcanizing agent, and 0.5 parts of vulcanization accelerator.

4. The fluorosilicone rubber compound according to any one of claims 1 to 3, characterized in that, The filler is any one or a mixture of any of the following: diatomaceous earth, silica powder, and precipitated silica. The structure control agent is either hydroxyl fluorosilicone oil or hydroxyl silicone oil; The vulcanizing agent is bis-2,5-(2,5-dimethyl-2,5-bis(tert-butadiene)hexane); The vulcanization accelerator is any one or a mixture of any of the following: triallyl isocyanurate and trimethylolpropane trimethacrylate.

5. The fluorosilicone rubber compound according to any one of claims 1 to 3, characterized in that, The preparation method of the fluorinated polyimide prepolymer includes the following steps: reacting hexafluorodianhydride with 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl to obtain a polyamic acid solution; adding maleic anhydride to the system and continuing the reaction to obtain the fluorinated polyimide prepolymer.

6. The fluorosilicone rubber compound according to claim 5, characterized in that, The molar ratio of hexafluorodianhydride, 2,2-bis(trifluoromethyl)-4,4'-diaminobiphenyl, and maleic anhydride is 1:1:0.1-0.15; the solvent for the reaction is an organic solvent; the reaction temperature is 10-40°C, and the reaction time is 2-6 hours; the temperature for further reaction is 40-60°C, and the reaction time is 1-3 hours.

7. A method for preparing the fluorosilicone rubber compound according to any one of claims 1 to 6, characterized in that, The method includes the following steps: mixing raw fluorosilicone rubber and fluorinated polyimide prepolymer, heating to remove solvent, then mixing with filler, structure control agent, vulcanizing agent and vulcanization accelerator, heating and vacuuming, placing and then re-refining and vulcanizing to obtain the final product.

8. The method according to claim 7, characterized in that, The mixing temperature is 25℃~60℃, and the time is 0.5~2h; the heating and vacuuming temperature is 60℃~100℃; the heating and vacuuming time is 0.1~1h; the standing time is 20~30h; and the number of re-mixing passes is 5~10.

9. The method according to claim 7, characterized in that, The vulcanization process is divided into a first-stage vulcanization and a second-stage vulcanization. The temperature of the first-stage vulcanization is 160℃~180℃, and the time is 5~15min. The temperature of the second-stage vulcanization is 190℃~210℃, and the time is 2~6h.

10. Use of the fluorosilicone rubber compound according to any one of claims 1 to 6 in the preparation of fluororubber products.

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