Oil-resistant anti-aging silicone tube and preparation process thereof

Abstract

The preparation process comprises the following steps: firstly, adding methyl vinyl silicone rubber, white carbon black, phenyl silicone oil and methyl silicone resin into a vacuum kneading machine, uniformly mixing at room temperature, and vacuumizing to obtain a rubber compound; then adding modified graphene fibers into the rubber compound, carrying out plasma treatment, carrying out primary uniform mixing, transferring to an open mill, carrying out gamma-ray radiation treatment, adding a vulcanizing agent, and carrying out secondary uniform mixing, so as to obtain a flaky rubber compound; and cutting the sheet rubber compound into strips, extruding on an extruder, vulcanizing, and shaping to obtain the silicone tube. The silicone tube has excellent oil resistance and aging resistance, and meets the use requirements of automobile turbochargers.

Description

Technical Field

[0001] The invention belongs to the technical field of silicone tube preparation, and particularly relates to an oil-resistant and aging-resistant silicone tube and a preparation process thereof. Background Art

[0002] Silicone tubing is a type of rubber tubing. It's made by mixing raw silicone rubber in a two-roll mill or closed kneader, adding silica and other additives, and mixing thoroughly before extrusion. Silicone tubing can be used for both the circulation and coating of liquids and gases, and is widely used in a variety of industries, including food, medical, electronics, and automotive.

[0003] Silicone rubber, the raw material for silicone tubing, is a high-molecular elastic material with excellent high and low temperature resistance, good physiological stability, and the ability to withstand repeated harsh conditions and disinfection. It has excellent resilience and minimal permanent deformation. Consequently, silicone tubing is non-toxic, highly acid and alkali resistant, highly elastic, well-resistant to pressure, and easy to clean and disinfect.

[0004] In the field of automobile manufacturing, silicone tubes are often used in automobile braking systems, fuel systems, cooling systems and other parts. In order to meet the safety requirements of automobiles, higher requirements are placed on the oil resistance and aging resistance of silicone tubes.

[0005] Ordinary silicone hoses have average oil resistance and can only be used when the oil temperature is below 150°C. Above this temperature, the silicone hose will age and even decompose. Currently, the oil resistance of silicone hoses is usually improved by adding organosilicon modifiers containing cycloalkyl groups.

[0006] Ozone and oxygen can cause silicone tubing to age. Ozone causes cracking, while oxygen destroys the molecular chains of silicone tubing. These factors can cause silicone tubing to harden, lose elasticity, or even crack after long-term use. Currently, the aging resistance of silicone tubing is often improved by adding light stabilizers or UV shielding agents.

[0007] Regardless of the means of improving oil resistance or anti-aging performance, there are generally problems such as poor stability and poor compatibility, which affect the final oil resistance and anti-aging performance, and at the same time affect the mechanical properties of the silicone tube.

[0008] Patent CN100520142C discloses a method for preparing a turbocharger hose made of fluororubber, oil-resistant silicone rubber, and silicone rubber. The resulting automotive turbocharger hose consists of an inner fluororubber layer, a middle oil-resistant silicone rubber layer, aramid yarn, and an outer silicone rubber layer. This patented technology utilizes a four-layer structure, improving the hose's oil resistance, high temperature resistance, and permeability resistance, while also increasing its burst pressure. However, multi-layer hoses have drawbacks such as high production and transportation costs, relatively poor recyclability, and poor environmental performance. Furthermore, the resulting hose's oil resistance and aging resistance still require significant improvement. Summary of the Invention

[0009] In view of the deficiencies in the prior art, the present invention aims to provide an oil-resistant and aging-resistant silicone tube and a preparation process thereof.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions: A preparation process for an oil-resistant and aging-resistant silicone tube comprises the following steps, measured in parts by weight: (1) First, add 10 parts of methyl vinyl silicone rubber, 3-4 parts of white carbon black, 0.6-0.8 parts of phenyl silicone oil and 0.5-0.6 parts of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature (25°C), and evacuate the mixture to obtain a rubber compound; (2) Then, 1 to 1.5 parts of modified graphene fiber are added to the rubber mix, plasma treated, mixed evenly once, transferred to an open mixer, γ-ray irradiated, 0.2 to 0.3 parts of a vulcanizing agent are added, mixed evenly twice, and a sheet-like rubber mix is ​​obtained; (3) Cutting the sheet-like mixed rubber into strips, extruding it on an extruder, vulcanizing it, and shaping it to obtain a silicone tube; The modified graphene fiber is prepared by first using expanded graphite as raw material, doping it with cerium and zinc to obtain doped expanded graphite, and then mixing the doped expanded graphite with silicone rubber, peeling it, and then solution spinning it.

[0011] Preferably, the modified graphene fiber is prepared by the following method: (A) first ultrasonically disperse expanded graphite in a 20-30% ethanol aqueous solution having a volume concentration of 6-8 times its weight to obtain an expanded graphite dispersion, stirring and heating to 60-65° C., adding cerium nitrate hexahydrate and zinc nitrate hexahydrate, and conducting a microwave reaction at 800-1000 W. The solid was filtered, washed, and dried to obtain doped expanded graphite; (B) The doped expanded graphite is then mixed with the silicone rubber raw rubber and subjected to a first high-speed shear treatment. A platinum catalyst is then added and subjected to a second high-speed shear treatment to obtain a dispersion. The dispersion is then vacuumed to remove bubbles and the modified graphene fiber is prepared by a solution spinning method.

[0012] More preferably, in step (A), the mass ratio of expanded graphite, cerium nitrate hexahydrate, and zinc nitrate hexahydrate is 10:1-2:1-2.

[0013] More preferably, in step (A), the microwave reaction adopts intermittent irradiation, irradiating for 3 minutes and stopping for 1 minute, until the cumulative irradiation time is 25 to 35 minutes.

[0014] More preferably, in step (A), washing is performed 2 to 3 times with an ethanol aqueous solution having a volume concentration of 20 to 30%.

[0015] Further preferably, in step (B), the mass ratio of the doped expanded graphite, the silicone rubber raw rubber, and the platinum catalyst is 1:8-10:0.8-1, and the silicone rubber raw rubber is fluorosilicone rubber raw rubber.

[0016] Further preferably, in step (B), the process conditions of the first high-speed shearing treatment are: 20,000-30,000 r / min high-speed shearing for 20-30 minutes; the process conditions of the second high-speed shearing treatment are: 8,000-10,000 r / min high-speed shearing for 8-10 minutes.

[0017] Further preferably, in step (B), the solution spinning is specifically: injecting the dispersion into methyl silicone oil at 160-180°C through a syringe, so that the silicone rubber is thermally cured into fibers; wherein the inner diameter of the syringe needle is 0.5-0.6 mm, the injection speed is 5-7 cm / min, and the thermal curing time is 5-7 minutes.

[0018] Preferably, in step (1), the vacuuming condition is: vacuuming to 0.05 Pa at 180°C, and maintaining the temperature and vacuum for 2 to 3 hours.

[0019] Preferably, in step (2), the vulcanizing agent is a mixture of 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate, etc.

[0020] Preferably, in step (2), the plasma treatment conditions are as follows: evacuate to 0.05 Pa, introduce high-purity nitrogen at 1000-1200 sccm, perform the first plasma treatment, the ion source power is 8-10 kW, and the treatment time is 5-7 minutes; evacuate to 0.05 Pa again, introduce high-purity ammonia at 800-1000 sccm, perform the second plasma treatment, the ion source power is 6-8 kW, and the treatment time is 2-4 minutes.

[0021] Preferably, in step (2), the gamma ray radiation treatment conditions are: in an air atmosphere with 60 Co-γ is irradiated and modified with a dose of 80 to 100 kGy.

[0022] Preferably, in step (2), the primary mixing temperature is 60-70°C, and the secondary mixing temperature is 80-90°C.

[0023] Preferably, in step (3), the extrusion conditions are: die head 50-55°C, extrusion section 40-45°C, plasticizing section 40-45°C, screw 45-50°C.

[0024] Preferably, in step (3), the vulcanization conditions are: vulcanization at 150-160° C. for 20-30 minutes.

[0025] An oil-resistant and aging-resistant silicone tube is obtained through the above-mentioned preparation process.

[0026] The aforementioned oil-resistant and aging-resistant silicone tube is used in automobile turbochargers.

[0027] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides an oil-resistant and aging-resistant silicone tube and a preparation process thereof. Methyl vinyl silicone rubber, white carbon black, phenyl silicone oil, and methyl silicone resin are first added to a vacuum kneader, uniformly mixed at room temperature, and evacuated to obtain a rubber mix. Modified graphene fiber is then added to the rubber mix, plasma-treated, and uniformly mixed once. The rubber mix is ​​then transferred to an open mill, irradiated with gamma rays, and a vulcanizing agent is added. The rubber mix is ​​uniformly mixed again to obtain a sheet. The sheet is then cut into strips, extruded on an extruder, vulcanized, and shaped to obtain a silicone tube. The silicone tube has excellent oil resistance and aging resistance, meeting the requirements of automotive turbochargers.

[0028] A key technical aspect of the present invention lies in the modified graphene fiber. Expanded graphite is first doped with cerium and zinc to produce doped expanded graphite, which is then mixed with raw silicone rubber, exfoliated, and solution-spun to produce the fiber. The doped expanded graphite is doped with cerium and zinc, then mixed with raw silicone rubber and exfoliated to produce cerium- and zinc-doped graphene. Silicone-modified graphene fibers are then obtained via solution spinning. The synergistic effects of cerium, zinc, and graphene improve the product's oil resistance and aging resistance. Modifications to the fiber morphology and silicone rubber surface enhance compatibility within the system, further enhancing these benefits.

[0029] After adding the modified graphene fiber, the present invention performs plasma treatment and further performs gamma ray radiation treatment after the first mixing, thereby promoting full mixing between the raw materials and further improving the oil resistance and aging resistance of the product. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0031] The methyl vinyl silicone rubber involved in the present invention, brand 110-5, was purchased from Dongguan Bailing New Materials Co., Ltd.; phenyl silicone oil, brand 255-500, was purchased from Datuo Chemical (Guangzhou) Co., Ltd.; methyl silicone resin, brand MQ102, was purchased from Laiyang Shengbang Silicone Technology Co., Ltd.; fluorosilicone rubber raw rubber, brand FSR-808, was purchased from Changshu Hongjia Fluorine Technology Co., Ltd.

[0032] Example 1 A preparation process for an oil-resistant and aging-resistant silicone tube comprises the following steps: (1) First, add 10 kg of methyl vinyl silicone rubber, 3 kg of white carbon black, 0.6 kg of phenyl silicone oil and 0.5 kg of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature (25 ° C), and evacuate to obtain a mixed rubber; (2) Then, 1 kg of modified graphene fiber was added to the rubber mix, plasma treated, mixed evenly once, transferred to an open mixer, γ-ray irradiated, 0.2 kg of vulcanizing agent was added, mixed evenly twice, and a sheet-like rubber mix was obtained; (3) Cutting the sheet-like mixed rubber into strips, extruding it on an extruder, vulcanizing it, and shaping it to obtain a silicone tube; Wherein, the modified graphene fiber is prepared by the following method: (A) first ultrasonically disperse expanded graphite in a 20% ethanol aqueous solution having a volume concentration of 6 times its weight to obtain an expanded graphite dispersion, stirring and heating to 60° C., adding cerium nitrate hexahydrate and zinc nitrate hexahydrate, and conducting a microwave reaction at 800 W. The solid was filtered, washed, and dried to obtain doped expanded graphite; (B) The doped expanded graphite is then mixed with the silicone rubber raw rubber and subjected to a first high-speed shear treatment. A platinum catalyst is then added and subjected to a second high-speed shear treatment to obtain a dispersion. The dispersion is then vacuumed to remove bubbles and the modified graphene fiber is prepared by a solution spinning method.

[0033] In step (A), the mass ratio of expanded graphite, cerium nitrate hexahydrate, and zinc nitrate hexahydrate is 10:1:1.

[0034] The microwave reaction was performed using intermittent irradiation, with irradiation for 3 minutes and rest for 1 minute, until the cumulative irradiation time reached 25 minutes.

[0035] The plate was washed twice with 20% ethanol aqueous solution.

[0036] In step (B), the mass ratio of doped expanded graphite, silicone rubber raw rubber, and platinum catalyst is 1:8:0.8, and the silicone rubber raw rubber is fluorosilicone rubber raw rubber.

[0037] The process conditions for the first high-speed shearing treatment are: 20000r / min high-speed shearing for 20 minutes; the process conditions for the second high-speed shearing treatment are: 8000r / min high-speed shearing for 8 minutes.

[0038] Solution spinning is specifically as follows: the dispersion is injected into methyl silicone oil at 160°C through a syringe, so that the silicone rubber is cured into fibers by heat; wherein, the inner diameter of the syringe needle is 0.5 mm, the injection speed is 5 cm / min, and the heat curing time is 5 minutes.

[0039] In step (1), the vacuuming conditions are: vacuuming to 0.05 Pa at 180°C, and maintaining this temperature and vacuum for 2 hours.

[0040] In step (2), the vulcanizing agent is obtained by mixing 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate and the like.

[0041] The plasma treatment conditions were as follows: evacuate to 0.05 Pa, introduce high-purity nitrogen at 1000 sccm for the first plasma treatment, with an ion source power of 8 kW and a treatment time of 5 minutes; evacuate again to 0.05 Pa, introduce high-purity ammonia at 800 sccm for the second plasma treatment, with an ion source power of 6 kW and a treatment time of 2 minutes.

[0042] The γ-ray radiation treatment conditions are: in air atmosphere with 60 Co-γ was irradiated with a dose of 80 kGy.

[0043] The primary mixing temperature was 60°C, and the secondary mixing temperature was 80°C.

[0044] In step (3), the extrusion conditions are: die head 50°C, extrusion section 40°C, plasticizing section 40°C, and screw 45°C.

[0045] The curing conditions are: 150°C for 20 minutes.

[0046] Example 2 A preparation process for an oil-resistant and aging-resistant silicone tube comprises the following steps: (1) First, add 10 kg of methyl vinyl silicone rubber, 4 kg of white carbon black, 0.8 kg of phenyl silicone oil and 0.6 kg of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature (25 ° C), and evacuate to obtain a mixed rubber; (2) Then, 1.5 kg of modified graphene fiber was added to the rubber mix, plasma treated, mixed evenly once, transferred to an open mixer, γ-ray irradiated, 0.3 kg of vulcanizing agent was added, mixed evenly twice, and a sheet-like rubber mix was obtained; (3) Cutting the sheet-like mixed rubber into strips, extruding it on an extruder, vulcanizing it, and shaping it to obtain a silicone tube; Wherein, the modified graphene fiber is prepared by the following method: (A) first ultrasonically disperse expanded graphite in a 30% ethanol aqueous solution having a volume concentration of 8 times its weight to obtain an expanded graphite dispersion, stirring and heating to 65°C, adding cerium nitrate hexahydrate and zinc nitrate hexahydrate, reacting with a 1000W microwave, filtering and collecting a solid, washing, and drying to obtain doped expanded graphite; (B) The doped expanded graphite is then mixed with the silicone rubber raw rubber and subjected to a first high-speed shear treatment. A platinum catalyst is then added and subjected to a second high-speed shear treatment to obtain a dispersion. The dispersion is then vacuumed to remove bubbles and the modified graphene fiber is prepared by a solution spinning method.

[0047] In step (A), the mass ratio of expanded graphite, cerium nitrate hexahydrate, and zinc nitrate hexahydrate is 10:2:2.

[0048] The microwave reaction was performed using intermittent irradiation, with irradiation for 3 minutes and rest for 1 minute, until the cumulative irradiation time reached 35 minutes.

[0049] The plate was washed three times with 30% ethanol aqueous solution.

[0050] In step (B), the mass ratio of doped expanded graphite, silicone rubber and platinum catalyst is 1:10:1, and the silicone rubber is fluorosilicone rubber.

[0051] The process conditions for the first high-speed shearing treatment are: 30,000 r / min high-speed shearing for 30 minutes; the process conditions for the second high-speed shearing treatment are: 10,000 r / min high-speed shearing for 10 minutes.

[0052] Solution spinning is specifically as follows: the dispersion is injected into methyl silicone oil at 180°C through a syringe, and the silicone rubber is cured into fibers by heat; wherein, the inner diameter of the syringe needle is 0.6mm, the injection speed is 7cm / min, and the heat curing time is 7 minutes.

[0053] In step (1), the vacuuming conditions are: vacuuming to 0.05 Pa at 180°C, and maintaining this temperature and vacuum for 3 hours.

[0054] In step (2), the vulcanizing agent is obtained by mixing 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate and the like.

[0055] The plasma treatment conditions were as follows: evacuate to 0.05 Pa, introduce high-purity nitrogen at 1200 sccm for the first plasma treatment, ion source power of 10 kW, and treatment time of 7 minutes; evacuate again to 0.05 Pa, introduce high-purity ammonia at 1000 sccm for the second plasma treatment, ion source power of 8 kW, and treatment time of 4 minutes.

[0056] The γ-ray radiation treatment conditions are: in air atmosphere with 60 Co-γ was irradiated with a dose of 100 kGy.

[0057] The primary mixing temperature was 70°C, and the secondary mixing temperature was 90°C.

[0058] In step (3), the extrusion conditions are: die head 55°C, extrusion section 45°C, plasticizing section 45°C, and screw 50°C.

[0059] The curing conditions are: 160°C for 30 minutes.

[0060] Example 3 A preparation process for an oil-resistant and aging-resistant silicone tube comprises the following steps: (1) First, add 10 kg of methyl vinyl silicone rubber, 3.5 kg of white carbon black, 0.7 kg of phenyl silicone oil and 0.55 kg of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature (25 ° C), and evacuate to obtain a mixed rubber; (2) Then, 1.2 kg of modified graphene fiber was added to the rubber mix, plasma treated, mixed evenly once, transferred to an open mixer, γ-ray irradiated, 0.25 kg of vulcanizing agent was added, mixed evenly twice, and a sheet-like rubber mix was obtained; (3) Cutting the sheet-like mixed rubber into strips, extruding it on an extruder, vulcanizing it, and shaping it to obtain a silicone tube; Wherein, the modified graphene fiber is prepared by the following method: (A) first ultrasonically disperse expanded graphite in a 25% ethanol aqueous solution having a volume concentration of 7 times its weight to obtain an expanded graphite dispersion, and then stir and heat to 63°C, add cerium nitrate hexahydrate and zinc nitrate hexahydrate, and microwave react at 900W. The solid is then filtered, washed, and dried to obtain doped expanded graphite; (B) The doped expanded graphite is then mixed with the silicone rubber raw rubber and subjected to a first high-speed shear treatment. A platinum catalyst is then added and subjected to a second high-speed shear treatment to obtain a dispersion. The dispersion is then vacuumed to remove bubbles and the modified graphene fiber is prepared by a solution spinning method.

[0061] In step (A), the mass ratio of expanded graphite, cerium nitrate hexahydrate, and zinc nitrate hexahydrate is 10:1.5:1.5.

[0062] The microwave reaction was performed using intermittent irradiation, with irradiation for 3 minutes and rest for 1 minute, until the cumulative irradiation time reached 30 minutes.

[0063] The plate was washed twice with 25% ethanol solution.

[0064] In step (B), the mass ratio of doped expanded graphite, silicone rubber raw rubber, and platinum catalyst is 1:9:0.9, and the silicone rubber raw rubber is fluorosilicone rubber raw rubber.

[0065] The process conditions for the first high-speed shearing treatment are: 25000 r / min high-speed shearing for 25 minutes; the process conditions for the second high-speed shearing treatment are: 9000 r / min high-speed shearing for 9 minutes.

[0066] Solution spinning is specifically as follows: the dispersion is injected into methyl silicone oil at 170°C through a syringe, so that the silicone rubber is cured into fibers by heat; wherein, the inner diameter of the syringe needle is 0.5mm, the injection speed is 6cm / min, and the heat curing time is 6 minutes.

[0067] In step (1), the vacuuming conditions are: vacuuming to 0.05 Pa at 180°C, and maintaining this temperature and vacuum for 2 hours.

[0068] In step (2), the vulcanizing agent is obtained by mixing 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate and the like.

[0069] The plasma treatment conditions were as follows: evacuate to 0.05 Pa, introduce high-purity nitrogen at 1100 sccm for the first plasma treatment, ion source power of 9 kW, and treatment time of 6 minutes; evacuate again to 0.05 Pa, introduce high-purity ammonia at 900 sccm for the second plasma treatment, ion source power of 7 kW, and treatment time of 3 minutes.

[0070] The γ-ray radiation treatment conditions are: in air atmosphere with 60 Co-γ was irradiated with a dose of 90 kGy.

[0071] The primary mixing temperature was 65°C, and the secondary mixing temperature was 85°C.

[0072] In step (3), the extrusion conditions are: die head 52°C, extrusion section 42°C, plasticizing section 42°C, and screw 48°C.

[0073] The curing conditions are: 155°C for 25 minutes.

[0074] Comparative Example 1 A preparation process for a silicone tube comprises the following steps: (1) First, add 10 kg of methyl vinyl silicone rubber, 3 kg of white carbon black, 0.6 kg of phenyl silicone oil and 0.5 kg of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature (25 ° C), and evacuate to obtain a mixed rubber; (2) Then, 1 kg of modified graphene fiber was added to the rubber mix, plasma treated, mixed evenly once, transferred to an open mixer, γ-ray irradiated, 0.2 kg of vulcanizing agent was added, mixed evenly twice, and a sheet-like rubber mix was obtained; (3) Cutting the sheet-like mixed rubber into strips, extruding it on an extruder, vulcanizing it, and shaping it to obtain a silicone tube; Wherein, the modified graphene fiber is prepared by the following method: (A) first ultrasonically disperse expanded graphite in a 20% ethanol aqueous solution having a volume concentration of 6 times its weight to obtain an expanded graphite dispersion, stirring and heating to 60° C., adding cerium nitrate hexahydrate, conducting a microwave reaction at 800 W, filtering and collecting a solid, washing, and drying to obtain doped expanded graphite; (B) The doped expanded graphite is then mixed with the silicone rubber raw rubber and subjected to a first high-speed shear treatment. A platinum catalyst is then added and subjected to a second high-speed shear treatment to obtain a dispersion. The dispersion is then vacuumed to remove bubbles and the modified graphene fiber is prepared by a solution spinning method.

[0075] In step (A), the mass ratio of expanded graphite to cerium nitrate hexahydrate is 10:1.

[0076] The microwave reaction was performed using intermittent irradiation, with irradiation for 3 minutes and rest for 1 minute, until the cumulative irradiation time reached 25 minutes.

[0077] The plate was washed twice with 20% ethanol aqueous solution.

[0078] In step (B), the mass ratio of doped expanded graphite, silicone rubber raw rubber, and platinum catalyst is 1:8:0.8, and the silicone rubber raw rubber is fluorosilicone rubber raw rubber.

[0079] The process conditions for the first high-speed shearing treatment are: 20000r / min high-speed shearing for 20 minutes; the process conditions for the second high-speed shearing treatment are: 8000r / min high-speed shearing for 8 minutes.

[0080] Solution spinning is specifically as follows: the dispersion is injected into methyl silicone oil at 160°C through a syringe, so that the silicone rubber is cured into fibers by heat; wherein, the inner diameter of the syringe needle is 0.5 mm, the injection speed is 5 cm / min, and the heat curing time is 5 minutes.

[0081] In step (1), the vacuuming conditions are: vacuuming to 0.05 Pa at 180°C, and maintaining this temperature and vacuum for 2 hours.

[0082] In step (2), the vulcanizing agent is obtained by mixing 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate and the like.

[0083] The plasma treatment conditions were as follows: evacuate to 0.05 Pa, introduce high-purity nitrogen at 1000 sccm for the first plasma treatment, with an ion source power of 8 kW and a treatment time of 5 minutes; evacuate again to 0.05 Pa, introduce high-purity ammonia at 800 sccm for the second plasma treatment, with an ion source power of 6 kW and a treatment time of 2 minutes.

[0084] The γ-ray radiation treatment conditions are: in air atmosphere with 60Co-γ was irradiated with a dose of 80 kGy.

[0085] The primary mixing temperature was 60°C, and the secondary mixing temperature was 80°C.

[0086] In step (3), the extrusion conditions are: die head 50°C, extrusion section 40°C, plasticizing section 40°C, and screw 45°C.

[0087] The curing conditions are: 150°C for 20 minutes.

[0088] Comparative Example 2 A preparation process for a silicone tube comprises the following steps: (1) First, add 10 kg of methyl vinyl silicone rubber, 3 kg of white carbon black, 0.6 kg of phenyl silicone oil and 0.5 kg of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature (25 ° C), and evacuate to obtain a mixed rubber; (2) The mixed rubber is then subjected to plasma treatment, mixed evenly once, transferred to an open mixer, irradiated with gamma rays, 0.2 kg of a vulcanizing agent is added, and mixed evenly a second time to obtain a sheet-like mixed rubber; (3) Cut the sheet-like mixed rubber into strips and extrude them on an extruder, vulcanize them, and shape them to obtain a silicone tube.

[0089] In step (1), the vacuuming conditions are: vacuuming to 0.05 Pa at 180°C, and maintaining this temperature and vacuum for 2 hours.

[0090] In step (2), the vulcanizing agent is obtained by mixing 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate and the like.

[0091] The plasma treatment conditions were as follows: evacuate to 0.05 Pa, introduce high-purity nitrogen at 1000 sccm for the first plasma treatment, with an ion source power of 8 kW and a treatment time of 5 minutes; evacuate again to 0.05 Pa, introduce high-purity ammonia at 800 sccm for the second plasma treatment, with an ion source power of 6 kW and a treatment time of 2 minutes.

[0092] The γ-ray radiation treatment conditions are: in air atmosphere with 60 Co-γ was irradiated with a dose of 80 kGy.

[0093] The primary mixing temperature was 60°C, and the secondary mixing temperature was 80°C.

[0094] In step (3), the extrusion conditions are: die head 50°C, extrusion section 40°C, plasticizing section 40°C, and screw 45°C.

[0095] The curing conditions are: 150°C for 20 minutes.

[0096] Comparative Example 3 A preparation process for a silicone tube comprises the following steps: (1) First, add 10 kg of methyl vinyl silicone rubber, 3 kg of white carbon black, 0.6 kg of phenyl silicone oil and 0.5 kg of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature (25 ° C), and evacuate to obtain a mixed rubber; (2) Then, 1 kg of modified graphene fiber was added to the rubber mix, mixed evenly once, transferred to an open mixer, irradiated with gamma rays, and 0.2 kg of vulcanizing agent was added, mixed evenly for a second time, and a sheet-like rubber mix was obtained; (3) Cutting the sheet-like mixed rubber into strips, extruding it on an extruder, vulcanizing it, and shaping it to obtain a silicone tube; Wherein, the modified graphene fiber is prepared by the following method: (A) first ultrasonically disperse expanded graphite in a 20% ethanol aqueous solution having a volume concentration of 6 times its weight to obtain an expanded graphite dispersion, stirring and heating to 60° C., adding cerium nitrate hexahydrate and zinc nitrate hexahydrate, and conducting a microwave reaction at 800 W. The solid was filtered, washed, and dried to obtain doped expanded graphite; (B) The doped expanded graphite is then mixed with the silicone rubber raw rubber and subjected to a first high-speed shear treatment. A platinum catalyst is then added and subjected to a second high-speed shear treatment to obtain a dispersion. The dispersion is then vacuumed to remove bubbles and the modified graphene fiber is prepared by a solution spinning method.

[0097] In step (A), the mass ratio of expanded graphite, cerium nitrate hexahydrate, and zinc nitrate hexahydrate is 10:1:1.

[0098] The microwave reaction was performed using intermittent irradiation, with irradiation for 3 minutes and rest for 1 minute, until the cumulative irradiation time reached 25 minutes.

[0099] The plate was washed twice with 20% ethanol aqueous solution.

[0100] In step (B), the mass ratio of doped expanded graphite, silicone rubber raw rubber, and platinum catalyst is 1:8:0.8, and the silicone rubber raw rubber is fluorosilicone rubber raw rubber.

[0101] The process conditions for the first high-speed shearing treatment are: 20000r / min high-speed shearing for 20 minutes; the process conditions for the second high-speed shearing treatment are: 8000r / min high-speed shearing for 8 minutes.

[0102] Solution spinning is specifically as follows: the dispersion is injected into methyl silicone oil at 160°C through a syringe, so that the silicone rubber is cured into fibers by heat; wherein, the inner diameter of the syringe needle is 0.5 mm, the injection speed is 5 cm / min, and the heat curing time is 5 minutes.

[0103] In step (1), the vacuuming conditions are: vacuuming to 0.05 Pa at 180°C, and maintaining this temperature and vacuum for 2 hours.

[0104] In step (2), the vulcanizing agent is obtained by mixing 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate and the like.

[0105] The γ-ray radiation treatment conditions are: in air atmosphere with 60 Co-γ was irradiated with a dose of 80 kGy.

[0106] The primary mixing temperature was 60°C, and the secondary mixing temperature was 80°C.

[0107] In step (3), the extrusion conditions are: die head 50°C, extrusion section 40°C, plasticizing section 40°C, and screw 45°C.

[0108] The curing conditions are: 150°C for 20 minutes.

[0109] Comparative Example 4 A preparation process for a silicone tube comprises the following steps: (1) First, add 10 kg of methyl vinyl silicone rubber, 3 kg of white carbon black, 0.6 kg of phenyl silicone oil and 0.5 kg of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature (25 ° C), and evacuate to obtain a mixed rubber; (2) Then, 1 kg of modified graphene fiber was added to the rubber mix, plasma treated, mixed evenly once, transferred to an open mixer, 0.2 kg of vulcanizing agent was added, and mixed evenly for a second time to obtain a sheet-like rubber mix; (3) Cutting the sheet-like mixed rubber into strips, extruding it on an extruder, vulcanizing it, and shaping it to obtain a silicone tube; Wherein, the modified graphene fiber is prepared by the following method: (A) first ultrasonically disperse expanded graphite in a 20% ethanol aqueous solution having a volume concentration of 6 times its weight to obtain an expanded graphite dispersion, stirring and heating to 60° C., adding cerium nitrate hexahydrate and zinc nitrate hexahydrate, and conducting a microwave reaction at 800 W. The solid was filtered, washed, and dried to obtain doped expanded graphite; (B) The doped expanded graphite is then mixed with the silicone rubber raw rubber and subjected to a first high-speed shear treatment. A platinum catalyst is then added and subjected to a second high-speed shear treatment to obtain a dispersion. The dispersion is then vacuumed to remove bubbles and the modified graphene fiber is prepared by a solution spinning method.

[0110] In step (A), the mass ratio of expanded graphite, cerium nitrate hexahydrate, and zinc nitrate hexahydrate is 10:1:1.

[0111] The microwave reaction was performed using intermittent irradiation, with irradiation for 3 minutes and rest for 1 minute, until the cumulative irradiation time reached 25 minutes.

[0112] The plate was washed twice with 20% ethanol aqueous solution.

[0113] In step (B), the mass ratio of doped expanded graphite, silicone rubber raw rubber, and platinum catalyst is 1:8:0.8, and the silicone rubber raw rubber is fluorosilicone rubber raw rubber.

[0114] The process conditions for the first high-speed shearing treatment are: 20000r / min high-speed shearing for 20 minutes; the process conditions for the second high-speed shearing treatment are: 8000r / min high-speed shearing for 8 minutes.

[0115] Solution spinning is specifically as follows: the dispersion is injected into methyl silicone oil at 160°C through a syringe, so that the silicone rubber is cured into fibers by heat; wherein, the inner diameter of the syringe needle is 0.5 mm, the injection speed is 5 cm / min, and the heat curing time is 5 minutes.

[0116] In step (1), the vacuuming conditions are: vacuuming to 0.05 Pa at 180°C, and maintaining this temperature and vacuum for 2 hours.

[0117] In step (2), the vulcanizing agent is obtained by mixing 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate and the like.

[0118] The plasma treatment conditions were as follows: evacuate to 0.05 Pa, introduce high-purity nitrogen at 1000 sccm for the first plasma treatment, with an ion source power of 8 kW and a treatment time of 5 minutes; evacuate again to 0.05 Pa, introduce high-purity ammonia at 800 sccm for the second plasma treatment, with an ion source power of 6 kW and a treatment time of 2 minutes.

[0119] The primary mixing temperature was 60°C, and the secondary mixing temperature was 80°C.

[0120] In step (3), the extrusion conditions are: die head 50°C, extrusion section 40°C, plasticizing section 40°C, and screw 45°C.

[0121] The curing conditions are: 150°C for 20 minutes.

[0122] The properties of the silicone tubes obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were tested, specifically including: 1. Initial tensile strength: Type 1 dumbbell specimens were prepared with reference to GB / T 528-2009 “Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties” and tensile strength tests were performed.

[0123] 2. Oil resistance: Immerse the sample in No. 3 standard oil, heat it to 100℃, and keep it warm for 70 hours. Take out the sample, wipe it clean, and then conduct the tensile strength test again to calculate the change rate of tensile strength.

[0124] 3. Anti-aging performance: An aging test (250°C hot air aging for 72 hours) was conducted with reference to GB / T 3512-2014 “Vulcanized rubber or thermoplastic rubber — Hot air accelerated aging and heat resistance tests”. After aging, a tensile strength test was conducted again to calculate the rate of change in tensile strength.

[0125] The test results are shown in Table 1.

[0126] Table 1. Silicone tube performance test results As shown in Table 1, the silicone tubes obtained in Examples 1 to 3 have good mechanical properties, excellent oil resistance and anti-aging properties, and can meet the use requirements of automotive turbochargers.

[0127] In Comparative Example 1, zinc nitrate hexahydrate was omitted when preparing the doped expanded graphite, the modified graphene fiber was omitted in Comparative Example 2, the plasma treatment was omitted in Comparative Example 3, and the gamma-ray radiation treatment was omitted in Comparative Example 4. The mechanical properties, oil resistance, and aging resistance were significantly deteriorated, indicating that the specially prepared modified graphene fiber of the present invention has a reinforcing effect and improves the oil resistance and aging resistance of the product. The plasma treatment and gamma-ray radiation treatment help to fully mix the raw materials and ensure product performance.

[0128] While the present invention is illustrated by the aforementioned embodiments, the present invention is not limited to these embodiments, nor does it necessarily rely on these embodiments for implementation. Those skilled in the art will appreciate that any improvements to the present invention, equivalent replacements for individual raw materials in the present invention, additions of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A preparation process for an oil-resistant and aging-resistant silicone tube, characterized in that: Calculated by weight, comprising the following steps: (1) First, add 10 parts of methyl vinyl silicone rubber, 3-4 parts of white carbon black, 0.6-0.8 parts of phenyl silicone oil and 0.5-0.6 parts of methyl silicone resin into a vacuum kneader, mix them evenly at room temperature, and evacuate the mixture to obtain a rubber mixture; (2) Then, 1 to 1.5 parts of modified graphene fiber are added to the rubber mix, plasma treated, mixed evenly once, transferred to an open mixer, γ-ray irradiated, 0.2 to 0.3 parts of a vulcanizing agent are added, mixed evenly twice, and a sheet-like rubber mix is ​​obtained; (3) Cutting the sheet-like mixed rubber into strips, extruding it on an extruder, vulcanizing it, and shaping it to obtain a silicone tube; The modified graphene fiber is prepared by first using expanded graphite as raw material, doping it with cerium and zinc to obtain doped expanded graphite, and then mixing the doped expanded graphite with silicone rubber, peeling it, and then solution spinning it.

2. The preparation process according to claim 1, characterized in that The modified graphene fiber is prepared by the following method: (A) first ultrasonically disperse expanded graphite in a 20-30% ethanol aqueous solution having a volume concentration of 6-8 times its weight to obtain an expanded graphite dispersion, stirring and heating to 60-65° C., adding cerium nitrate hexahydrate and zinc nitrate hexahydrate, and conducting a microwave reaction at 800-1000 W. The solid was filtered, washed, and dried to obtain doped expanded graphite; (B) The doped expanded graphite is then mixed with the silicone rubber raw rubber and subjected to a first high-speed shear treatment. A platinum catalyst is then added and subjected to a second high-speed shear treatment to obtain a dispersion. The dispersion is then vacuumed to remove bubbles and the modified graphene fiber is prepared by a solution spinning method.

3. The preparation process according to claim 1, characterized in that In step (1), the vacuuming conditions are: vacuuming to 0.05 Pa at 180°C, and maintaining the temperature and vacuum for 2 to 3 hours.

4. The preparation process according to claim 1, characterized in that In step (2), the vulcanizing agent is obtained by mixing 2,4-dichlorobenzoyl peroxide, diisopropylbenzene peroxide, triallyl isocyanurate and the like.

5. The preparation process according to claim 1, characterized in that: In step (2), the plasma treatment conditions are as follows: evacuate to 0.05 Pa, introduce high-purity nitrogen at 1000-1200 sccm, perform the first plasma treatment, the ion source power is 8-10 kW, and the treatment time is 5-7 minutes; evacuate to 0.05 Pa again, introduce high-purity ammonia at 800-1000 sccm, perform the second plasma treatment, the ion source power is 6-8 kW, and the treatment time is 2-4 minutes.

6. The preparation process according to claim 1, characterized in that In step (2), the gamma ray radiation treatment conditions are: in an air atmosphere with 60 Co-γ is irradiated and modified with a dose of 80 to 100 kGy.

7. The preparation process according to claim 1, characterized in that In step (2), the primary mixing temperature is 60-70°C, and the secondary mixing temperature is 80-90°C.

8. The preparation process according to claim 1, characterized in that In step (3), the extrusion conditions are: die head 50-55°C, extrusion section 40-45°C, plasticizing section 40-45°C, screw 45-50°C; The vulcanization conditions are: 150-160°C for 20-30 minutes.

9. An oil-resistant and anti-aging silicone tube, characterized in that: The invention is obtained by the preparation process according to any one of claims 1 to 8.

10. Use of the oil-resistant and anti-aging silicone tube according to claim 9 in an automobile turbocharger.

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