Multi-layer composite extrusion rubber tube and preparation method thereof

Abstract

The invention discloses a multi-layer composite extrusion rubber tube and a preparation method thereof.The preparation method comprises the steps that zirconium acetylacetonate, polyborosilazane, polydimethylsiloxane and carbon nanofibers serve as raw materials, and zirconium-doped silicon carbide / boron nitride fibers are prepared; then, the zirconium doped silicon carbide / boron nitride fibers are subjected to modification treatment through gamma-methacryloxy propyl trimethoxy silane, and modified fibers are obtained; then taking the modified fiber and an acrylate monomer as raw materials, and reacting to obtain polyacrylate modified fiber; taking acrylate rubber and polyacrylate modified fiber as main raw materials, and mixing to obtain a rubber material; the production method comprises the following steps: extruding an inner rubber layer by using a rubber material, knitting aramid fiber threads on the surface of the inner rubber layer to form a reinforcing layer, uniformly spraying silicone oil on the surface of the reinforcing layer, carrying out electron irradiation treatment, extruding an outer rubber layer by using the rubber material, and carrying out post-treatment. The obtained rubber pipe is excellent in performance, and the working requirement of the turbocharger air inlet rubber pipe is met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of rubber pipe preparation, and particularly relates to a multi-layer composite extruded rubber pipe and a preparation method thereof. BACKGROUND

[0002] With the improvement of people's living standards and the development of the automobile industry, automobiles have become an indispensable important means of transportation in daily life, and people's quality requirements for rubber pipes used in automobiles are also getting higher and higher.

[0003] Taking a turbocharger as an example, the turbocharger increases the intake air volume by compressing air, uses the exhaust energy of the engine to drive the turbine, and drives the compressor to improve the intake pressure of the engine. Specifically, the turbocharger uses the inertial impact force of the exhaust gas discharged by the engine to push the turbine in the turbine chamber, and the turbine drives the impeller on the same shaft to compress the air from the air filter pipe into the cylinder. The exhaust gas discharge speed and the turbine speed increase with the increase of the engine speed, and the impeller can compress more air into the cylinder, so that the pressure and density of the air increase to promote more fuel combustion, increase the fuel quantity and adjust the engine speed, and increase the output power of the engine. The turbocharger increases the fuel quantity by compressing more air into the cylinder, thereby improving the combustion function, greatly improving the fuel economy, reducing the exhaust emission, and greatly improving the maximum output power and torque of the engine. Based on the working environment of the turbocharger, the quality requirements of the turbocharger intake rubber pipe are higher, especially the pressure resistance and pulse fatigue performance.

[0004] At present, the turbocharger intake rubber pipe is mainly obtained by two methods of extrusion molding process and winding molding process. Among them, the rubber pipe obtained by the extrusion molding process has poor pressure resistance, which is difficult to meet the performance requirements of the turbocharger intake rubber pipe. The production cost of the winding molding process is high, and it is difficult to control the production uniformity, the product performance cannot be guaranteed, and it involves one-time raw materials and subsequent cutting, etc., causing resource waste.

[0005] Patent application CN118978769A discloses a UPE multi-layer composite extruded rubber pipe and a preparation method thereof, which uses functional plastic, ethylene-propylene-diene rubber composite material, white filler, pigment, zinc oxide, stearic acid, antioxidant, microcrystalline wax, sulfur, accelerator, etc. as raw materials, uses ultra-high molecular weight polyethylene UPE as the inner lining layer of the rubber pipe, uses medium molecular weight polyethylene modified UPE extrusion process to extrude, and coats EPDM rubber as the outer layer on the outer side of the pipe. The UPE plastic and the ethylene-propylene-diene rubber are tightly combined into a whole, so as to obtain a rubber pipe with the advantages of UPE and EPDM. The multi-layer rubber pipe is a good method to improve the performance of the rubber pipe, but the rubber pipe obtained by the patent application still cannot meet the use requirements of the turbocharger intake rubber pipe. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a multi-layer composite extruded rubber pipe and a preparation method thereof, which has excellent performance and meets the working requirements of turbocharger intake rubber pipes.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: The preparation method of the multi-layer composite extruded rubber pipe comprises the following steps: (1) First, zirconium acetylacetonate, polysilazane, polydimethylsiloxane and carbon nanofiber are used as raw materials to prepare zirconium-doped silicon carbide / boron nitride fiber; (2) Then, the zirconium-doped silicon carbide / boron nitride fiber is modified by using gamma-methacryloxypropyltrimethoxysilane to obtain modified fiber; (3) Then, the modified fiber and acrylate monomer are used as raw materials to react to obtain polyacrylate modified fiber; (4) Acrylate rubber and polyacrylate modified fiber are used as main raw materials to mix and obtain rubber compound; (5) The rubber compound is used to extrude the inner rubber layer, aramid fiber is knitted on the surface of the inner rubber layer to form a reinforcing layer, silicone oil is uniformly sprayed on the surface of the reinforcing layer, electronic irradiation treatment is performed, the rubber compound is used to extrude the outer rubber layer, and post-treatment is performed, thereby obtaining the multi-layer composite extruded rubber pipe.

[0008] Preferably, the specific method of step (1) is as follows: first, zirconium acetylacetonate, polysilazane and carbon nanofiber are uniformly mixed to obtain a mixture, then polydimethylsiloxane is uniformly coated on the surface of the mixture, heating treatment is performed, dimethylbenzene is dissolved, filtration is performed, and reduced pressure distillation is performed to obtain a mixture, then the mixture is placed in a melt spinning cylinder, heated to melting under a nitrogen atmosphere, pressurized, the melt flows through a filter screen and a spinneret plate to form a fiber bundle, heating crosslinking is performed, sintering is performed, and the fiber bundle is crushed to less than 1 μm, thereby obtaining the zirconium-doped silicon carbide / boron nitride fiber.

[0009] Further preferably, the mass ratio of zirconium acetylacetonate, polysilazane, carbon nanofiber and polydimethylsiloxane is 10:1-2:0.05-0.07:110-120; the particle size of the carbon nanofiber is 50-70 nm, and the length is 5-10 μm.

[0010] Further preferably, the process conditions of the heating treatment are as follows: heating at 20-25 ℃ / min to 180-200 ℃, and maintaining the temperature for 2-3 hours.

[0011] Further preferably, heating is performed at 0.5-0.7 ℃ / min to melting, and the pressure is pressurized to 3-5 MPa.

[0012] Further preferably, the heating crosslinking conditions are as follows: heating crosslinking at 330-350 ℃ for 4-6 hours. Further preferably, the heating crosslinking conditions are as follows: heating crosslinking at 330-350 ℃ for 4-6 hours.

[0013] Further preferably, the sintering conditions are as follows: first, pass ammonia gas at a flow rate of 300-350 mL / min, heat to 500-600 ℃ at a rate of 50-70 ℃ / min, and keep the temperature for 2-3 hours; then heat to 800-900 ℃ at the same rate, keep the temperature for 2-3 hours; then pass argon gas at a flow rate of 100-200 mL / min, heat to 1400-1500 ℃ at a rate of 20-30 ℃ / min, keep the temperature for 1-2 hours; then pass air at a flow rate of 100-200 mL / min, keep the temperature for 1-2 hours, and then cool down in the furnace.

[0014] Preferably, the specific method of step (2) is as follows: stir and disperse the zirconium-doped silicon carbide / boron nitride fiber in anhydrous ethanol, heat to reflux, keep stirring for 20-30 minutes, then add γ-methacryloxypropyltrimethoxysilane, continue to keep stirring for 80-90 minutes, centrifuge to obtain the precipitate, and dry; the mass ratio of the zirconium-doped silicon carbide / boron nitride fiber, anhydrous ethanol, and γ-methacryloxypropyltrimethoxysilane is 1:3-4:0.02-0.03.

[0015] Preferably, the specific method of step (3) is as follows: mix the modified fiber, acrylic ester monomer, water, initiator, and crosslinking agent uniformly, heat to 65-75 ℃ under a nitrogen atmosphere, keep stirring for 5-6 hours, filter to obtain the solid, wash with water, dry, and crush to below 1 μm; the mass ratio of the modified fiber, acrylic ester monomer, water, initiator, and crosslinking agent is 1:0.8-1:4-5:0.01-0.02:0.01-0.02.

[0016] Further preferably, the acrylic ester monomer is selected from any one of butyl acrylate, methyl methacrylate, or n-butyl methacrylate; the initiator is azobisisobutyronitrile or benzoyl peroxide; and the crosslinking agent is selected from allyl acrylate or allyl methacrylate.

[0017] Preferably, in step (4), the formula of the rubber compound is as follows: 10 parts of acrylic ester rubber, 0.7-0.9 parts of polyacrylate modified fiber, 0.1-0.2 parts of stearic acid, 3-5 parts of carbon black, 0.5-1 part of adipic acid diester, 0.05-0.1 part of stearyl alcohol polyether-2 phosphate, 0.1-0.2 part of 4,4-bis (α, α-dimethylphenyl) diphenylamine, 0.1-0.2 part of hexamethylene diamine carbamate, and 0.1-0.2 part of diphenyl guanidine.

[0018] Preferably, in step (4), the mixing method is as follows: the formula amount of acrylate rubber, polyacrylate modified fiber, stearic acid, carbon black, adipic acid diester, stearyl polyether-2 phosphate, 4,4-bis (alpha, alpha-dimethylphenyl) diphenylamine is added to the mixing machine for mixing, when the temperature reaches 110-120 DEG C, discharge, cooling, again into the mixing machine, and add adipic acid diamine carbamate, diphenyl guanidine, continue to mix until the temperature reaches 100-110 DEG C, discharge, cooling can.

[0019] Preferably, in step (5), the inner rubber layer is extruded using an extruder, and the temperature of the extruder from the head to the screw is 100-90 DEG C, 80-70 DEG C, 80-70 DEG C, 60-50 DEG C, 60-50 DEG C in turn; the outer rubber layer is extruded using an extruder, and the temperature of the extruder from the head to the screw is 100-90 DEG C, 80-70 DEG C, 80-70 DEG C, 60-50 DEG C, 60-50 DEG C in turn.

[0020] Preferably, in step (5), the aramid yarn 2520 dtex is knitted using a 10-needle knitting machine.

[0021] Preferably, in step (5), the spraying amount of silicone oil is 8-10 mL / cm 2 .

[0022] Preferably, in step (5), the electron irradiation treatment conditions are: electron beam energy 5-7 MeV, irradiation dose 70-80 kGy.

[0023] Preferably, in step (5), the post-treatment includes: core rod, 170-180 DEG C vulcanization for 20-30 minutes, cutting.

[0024] A multi-layer composite extruded rubber pipe is obtained by the foregoing preparation method.

[0025] The foregoing multi-layer composite extruded rubber pipe is used in the preparation of turbocharger intake rubber pipe.

[0026] Compared with the prior art, the present application has the following beneficial effects: The application provides a multilayer composite extrusion rubber pipe and a preparation method thereof, and first, zirconium-doped silicon carbide / boron nitride fibers are prepared by taking acetylacetone zirconium, polysilazane, polydimethylsiloxane and carbon nanofibers as raw materials; then, the zirconium-doped silicon carbide / boron nitride fibers are modified by using γ-methacryloxypropyl trimethoxysilane to obtain modified fibers; then, the modified fibers and acrylate monomers are taken as raw materials to react to obtain polyacrylate modified fibers; acrylate rubber and the polyacrylate modified fibers are taken as main raw materials to mix and mill to obtain a rubber compound; the rubber compound is extruded to form an inner rubber layer, aramid yarn is knitted on the surface of the inner rubber layer to form a reinforcing layer, silicon oil is uniformly sprayed on the surface of the reinforcing layer, electron irradiation treatment is performed, an outer rubber layer is extruded by using the rubber compound, and post-treatment is performed, and the multilayer composite extrusion rubber pipe is obtained. The rubber pipe has excellent performance and meets the working requirements of a turbocharger intake rubber pipe.

[0027] The rubber pipe of the application comprises an inner rubber layer, a reinforcing layer and an outer rubber layer, and silicon oil is sprayed between the reinforcing layer and the outer rubber layer, and electron irradiation treatment is combined to enhance the adhesion between the layers and improve the performance of the rubber pipe. If the irradiation dose is not enough, the adhesion improvement is not enough, and if the irradiation dose is too much, the performance of the rubber pipe will be affected.

[0028] The inner rubber layer and the outer rubber layer are prepared by extrusion, and the rubber compound used is prepared by taking acrylate rubber and polyacrylate modified fibers as main raw materials. The acrylate rubber has good heat resistance, aging resistance and oil resistance, and is an ideal raw material for preparing a turbocharger intake rubber pipe. The polyacrylate modified fibers have good compatibility with the acrylate rubber, and further improve the performance of the product.

[0029] The polyacrylate modified fibers are obtained by taking the zirconium-doped silicon carbide / boron nitride fibers as raw materials, modifying the fibers by using γ-methacryloxypropyl trimethoxysilane, and then reacting the modified fibers and acrylate monomers. The surface of the fibers is modified by polyacrylate, so that the compatibility of the fiber material in the acrylate rubber is improved, and the excellent performance of the fiber material is exerted. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0031] The acrylate rubber is purchased from Jiangsu Puleisi Biological Technology Co., Ltd.

[0032] The other goods in the application are purchased through market channels.

[0033] Example 1 A method for preparing a multi-layer composite extruded rubber tube, comprising the following steps: (1) First, zirconium doped silicon carbide / boron nitride fibers are prepared using zirconium acetylacetonate, polyborosilazane, polydimethylsiloxane, and carbon nanofibers as raw materials; The specific method is as follows: first, zirconium acetylacetonate, polyborosilazane, and carbon nanofibers are uniformly mixed to obtain a mixture, then polydimethylsiloxane is uniformly coated on the surface of the mixture, heated, dissolved in xylene, filtered, and distilled under reduced pressure to obtain a mixture, and then the mixture is placed in a melt spinning cylinder, heated to melt under a nitrogen atmosphere, pressurized, and the melt flows through a filter screen and a spinneret to obtain a fiber bundle, which is heated, crosslinked, sintered, and crushed to less than 1 μm to obtain the zirconium doped silicon carbide / boron nitride fibers.

[0034] The mass ratio of zirconium acetylacetonate, polyborosilazane, carbon nanofibers, and polydimethylsiloxane is 10:1:0.05:110; the particle size of the carbon nanofibers is 50 nm, and the length is 5 μm.

[0035] The process conditions for the heating treatment are as follows: heating at 20 ℃ / min to 180 ℃, and holding for 2 hours.

[0036] Heating to melt at 0.5 ℃ / min and pressurizing to 3 MPa.

[0037] The heating crosslinking conditions are as follows: heating crosslinking at 330 ℃ for 4 hours.

[0038] The sintering conditions are as follows: first, passing ammonia gas at 300 mL / min, heating to 500 ℃ at 50 ℃ / min, and holding for 2 hours; then heating to 800 ℃ at the same rate, holding for 2 hours; then passing argon gas at 100 mL / min, heating to 1400 ℃ at 20 ℃ / min, holding for 1 hour; then passing air at 100 mL / min, continuing to hold for 1 hour, and cooling in the furnace.

[0039] (2) Then, the zirconium doped silicon carbide / boron nitride fibers are modified using γ-methacryloxypropyltrimethoxysilane to obtain modified fibers; The specific method is as follows: the zirconium doped silicon carbide / boron nitride fibers are stirred and dispersed in anhydrous ethanol, heated to reflux, held for 20 minutes, then γ-methacryloxypropyltrimethoxysilane is added, and the mixture is held for 80 minutes, then the precipitate is obtained by centrifugation and dried; the mass ratio of the zirconium doped silicon carbide / boron nitride fibers, anhydrous ethanol, and γ-methacryloxypropyltrimethoxysilane is 1:3:0.02.

[0040] (3) Then, the modified fibers and acrylate monomers are used as raw materials to react to obtain polyacrylate modified fibers. The specific method is: the modified fiber is mixed with acrylic ester monomer, water, initiator, crosslinking agent, heated to 65℃ under nitrogen atmosphere, and stirred for 5 hours. The solid is filtered, washed with water, dried, and crushed to below 1 μm. The mass ratio of the modified fiber to acrylic ester monomer, water, initiator, and crosslinking agent is 1:0.8:4:0.01:0.01.

[0041] The acrylic ester monomer is butyl acrylate; the initiator is azobis isobutyronitrile; and the crosslinking agent is allyl acrylate.

[0042] (4) Using acrylic ester rubber and polyacrylate modified fiber as main raw materials, mixing and obtaining a rubber compound; The formula of the rubber compound is as follows: acrylic ester rubber 10 kg, polyacrylate modified fiber 0.7 kg, stearic acid 0.1 kg, carbon black 3 kg, adipic acid diester 0.5 kg, stearyl alcohol polyether-2 phosphate 0.05 kg, 4,4-bis (α, α-dimethylphenyl) diphenylamine 0.1 kg, hexamethylene diamine carbamate 0.1 kg, and diphenyl guanidine 0.1 kg.

[0043] The mixing method is as follows: the formula amount of acrylic ester rubber, polyacrylate modified fiber, stearic acid, carbon black, adipic acid diester, stearyl alcohol polyether-2 phosphate, 4,4-bis (α, α-dimethylphenyl) diphenylamine are added into a mixing machine for mixing. When the temperature reaches 110℃, the material is discharged and cooled. Then the material is put into the mixing machine again, and hexamethylene diamine carbamate and diphenyl guanidine are added. The mixing continues until the temperature reaches 100℃. The material is discharged and cooled.

[0044] (5) Using the rubber compound to extrude an inner rubber layer, using aramid fiber to knit a reinforcing layer on the surface of the inner rubber layer, spraying silicon oil on the surface of the reinforcing layer, and using the rubber compound to extrude an outer rubber layer. After treatment, a multi-layer composite extruded rubber pipe is obtained.

[0045] An extruder is used to extrude the inner rubber layer. The temperature of the extruder from the head to the screw is 100℃, 80℃, 80℃, 60℃, and 60℃ in sequence. An extruder is used to extrude the outer rubber layer. The temperature of the extruder from the head to the screw is 100℃, 80℃, 80℃, 60℃, and 60℃ in sequence.

[0046] The aramid fiber is 2520 dtex, and is knitted by using a 10-needle knitting machine.

[0047] The spraying amount of the silicon oil is 8 mL / cm. 2 .

[0048] The electronic irradiation treatment condition is: electron beam energy 5 MeV, and irradiation dose 70 kGy.

[0049] Post-processing includes: core rod, 170℃ vulcanization 20 minutes, cutting.

[0050] Example 2 A method for preparing a multi-layer composite extruded rubber tube, comprising the following steps: (1) First, zirconium acetylacetonate, polysilazane, polydimethylsiloxane, carbon nanofiber are used as raw materials to prepare zirconium-doped silicon carbide / boron nitride fiber; The specific method is: first, zirconium acetylacetonate, polysilazane, and carbon nanofiber are uniformly mixed to obtain a mixture, then polydimethylsiloxane is uniformly coated on the surface of the mixture, heated, dissolved in xylene, filtered, and distilled under reduced pressure to obtain a mixture, and then the mixture is placed in a melt spinning cylinder, heated to melt under a nitrogen atmosphere, pressurized, and the melt flows through a filter screen and a spinneret to form a fiber bundle. Crosslinking, sintering, and crushing to 1 μm or less yield the zirconium-doped silicon carbide / boron nitride fiber.

[0051] The mass ratio of zirconium acetylacetonate, polysilazane, carbon nanofiber, and polydimethylsiloxane is 10:2:0.07:120; the particle size of the carbon nanofiber is 70 nm, and the length is 10 μm.

[0052] The process conditions for heating treatment are: heating at 25℃ / min to 200℃, and holding for 3 hours.

[0053] Heating to melt at 0.7℃ / min and pressurizing to 5MPa.

[0054] The crosslinking conditions are: heating at 350℃ for 6 hours.

[0055] The sintering conditions are: first, passing ammonia gas at 350mL / min, heating at 70℃ / min to 600℃, holding for 3 hours; then heating at the same rate to 900℃, holding for 3 hours; then passing argon gas at 200mL / min, heating at 30℃ / min to 1500℃, holding for 2 hours; then passing air at 200mL / min, continuing to hold for 2 hours, and cooling in the furnace.

[0056] (2) Then, the zirconium-doped silicon carbide / boron nitride fiber is modified with γ-methacryloxypropyltrimethoxysilane to obtain a modified fiber; The specific method is: the zirconium-doped silicon carbide / boron nitride fiber is stirred and dispersed in anhydrous ethanol, heated to reflux, and held for 30 minutes of stirring, then γ-methacryloxypropyltrimethoxysilane is added, and the stirring is continued for 90 minutes of holding. The precipitate is obtained by centrifugation and drying; the mass ratio of zirconium-doped silicon carbide / boron nitride fiber, anhydrous ethanol, and γ-methacryloxypropyltrimethoxysilane is 1:4:0.03.

[0057] (3) Then the modified fiber and acrylate monomer as raw material, reaction, obtain polyacrylate modified fiber; The specific method is as follows: the modified fiber is uniformly mixed with acrylate monomer, water, initiator and crosslinking agent, heated to 75℃ under nitrogen atmosphere, and stirred for 6 hours. The solid is filtered, washed with water, dried, and crushed to below 1μm. The mass ratio of the modified fiber to the acrylate monomer, water, initiator and crosslinking agent is 1:1:5:0.02:0.02.

[0058] The acrylate monomer is methyl methacrylate; the initiator is benzoyl peroxide; and the crosslinking agent is allyl methacrylate.

[0059] (4) Using acrylate rubber and polyacrylate modified fiber as main raw materials, mixing, obtaining rubber compound; The formula of the rubber compound is as follows: acrylate rubber 10kg, polyacrylate modified fiber 0.9kg, stearic acid 0.2kg, carbon black 5kg, adipic acid diester 1kg, stearyl alcohol polyether-2 phosphate 0.1kg, 4,4-bis (α, α-dimethylphenyl) diphenylamine 0.2kg, hexamethylene diamine carbamate 0.2kg, and diphenyl guanidine 0.2kg.

[0060] The mixing method is as follows: the formula amount of acrylate rubber, polyacrylate modified fiber, stearic acid, carbon black, adipic acid diester, stearyl alcohol polyether-2 phosphate, 4,4-bis (α, α-dimethylphenyl) diphenylamine are added into a mixing machine for mixing. When the temperature reaches 120℃, the material is discharged and cooled. Then the material is put into the mixing machine again, and hexamethylene diamine carbamate and diphenyl guanidine are added. The mixing continues until the temperature reaches 100-110℃. Then the material is discharged and cooled.

[0061] (5) Using the rubber compound to extrude the inner rubber layer, using aramid fiber to knit the reinforcing layer on the surface of the inner rubber layer, spraying silicon oil on the surface of the reinforcing layer, electronic irradiation treatment, using the rubber compound to extrude the outer rubber layer, and post-treatment, thus obtaining the multi-layer composite extruded rubber pipe.

[0062] The extruder is used to extrude the inner rubber layer, and the temperature of the extruder from the head to the screw is 90℃, 70℃, 70℃, 50℃, and 50℃ in sequence. The extruder is used to extrude the outer rubber layer, and the temperature of the extruder from the head to the screw is 90℃, 70℃, 70℃, 50℃, and 50℃ in sequence.

[0063] The aramid fiber is 2520 dtex, and is knitted by using a 10-needle knitting machine.

[0064] The spraying amount of silicon oil is 10mL / cm 2 .

[0065] The electron irradiation treatment condition is: electron beam energy 7 MeV, irradiation dose 80 kGy.

[0066] The post-treatment includes: core rod penetration, 180℃ curing for 30 minutes, and cutting.

[0067] Example 3 A preparation method of a multi-layer composite extruded rubber pipe, comprising the following steps: (1) first, zirconium acetylacetonate, polysilazane, polydimethylsiloxane, and carbon nanofiber are used as raw materials to prepare zirconium-doped silicon carbide / nitride boride fiber; The specific method is: first, zirconium acetylacetonate, polysilazane, and carbon nanofiber are uniformly mixed to obtain a mixture, then polydimethylsiloxane is uniformly coated on the surface of the mixture, heated, dissolved in xylene, filtered, and distilled under reduced pressure to obtain a mixture, and then the mixture is placed in a melt spinning cylinder, heated to melt under a nitrogen atmosphere, pressurized, and the melt flows through a filter screen and a spinneret plate to form a fiber bundle. Crosslinking, sintering, and crushing to below 1 μm are performed to obtain the zirconium-doped silicon carbide / nitride boride fiber.

[0068] The mass ratio of zirconium acetylacetonate, polysilazane, carbon nanofiber, and polydimethylsiloxane is 10:1:0.07:110; the particle size of the carbon nanofiber is 70 nm, and the length is 5 μm.

[0069] The process conditions for the heating treatment are: heating to 180℃ at 25℃ / min and holding for 3 hours.

[0070] Heating to melt at 0.5℃ / min and pressurizing to 5 MPa.

[0071] The crosslinking conditions are: heating at 330℃ for 6 hours.

[0072] The sintering conditions are: first, ammonia gas is passed at 300 mL / min, heated to 500℃ at 70℃ / min, and held for 3 hours; then heated to 800℃ at the same heating rate, held for 3 hours; then argon gas is passed at 100 mL / min, heated to 1400℃ at 30℃ / min, and held for 2 hours; then air is passed at 100 mL / min, and held for another 2 hours, and then the furnace is cooled.

[0073] (2) then, the zirconium-doped silicon carbide / nitride boride fiber is modified with γ-methacryloxypropyltrimethoxysilane to obtain modified fiber; The specific method is: the zirconium-doped silicon carbide / boron nitride fiber is stirred and dispersed in anhydrous ethanol, heated to reflux, and stirred for 20 minutes, then γ-methacryloxypropyl trimethoxysilane is added, and stirring is continued for 90 minutes, the precipitate is taken by centrifugation, and dried; the mass ratio of zirconium-doped silicon carbide / boron nitride fiber, anhydrous ethanol and γ-methacryloxypropyl trimethoxysilane is 1:3:0.03.

[0074] (3) Then the modified fiber is used as raw material to react with an acrylate monomer to obtain a polyacrylate modified fiber; The specific method is: the modified fiber is uniformly mixed with an acrylate monomer, water, an initiator and a crosslinking agent, heated to 65℃ under a nitrogen atmosphere, and stirred for 6 hours, then the solid is filtered, washed with water, dried, and pulverized to below 1 μm.

[0075] The acrylate monomer is n-butyl methacrylate; the initiator is azobisisobutyronitrile; and the crosslinking agent is allyl acrylate.

[0076] (4) An acrylate rubber and the polyacrylate modified fiber are used as main raw materials to mix and obtain a rubber compound; The formula of the rubber compound is as follows: acrylate rubber 10 kg, polyacrylate modified fiber 0.7 kg, stearic acid 0.2 kg, carbon black 3 kg, adipic acid diester 1 kg, stearyl alcohol polyether-2 phosphate 0.05 kg, 4,4-bis (α, α-dimethylphenyl) diphenylamine 0.2 kg, hexamethylene diamine carbamate 0.1 kg, and diphenyl guanidine 0.2 kg.

[0077] The mixing method is as follows: the formula amount of acrylate rubber, polyacrylate modified fiber, stearic acid, carbon black, adipic acid diester, stearyl alcohol polyether-2 phosphate, 4,4-bis (α, α-dimethylphenyl) diphenylamine are added into a mixing machine for mixing, when the temperature reaches 110℃, the material is discharged, cooled, again put into the mixing machine, and hexamethylene diamine carbamate and diphenyl guanidine are added, and the mixing is continued until the temperature reaches 110℃, the material is discharged, and cooled.

[0078] (5) The rubber compound is used to extrude an inner rubber layer, aramid fiber is knitted on the surface of the inner rubber layer to form a reinforcing layer, silicon oil is uniformly sprayed on the surface of the reinforcing layer, and the rubber compound is used to extrude an outer rubber layer, and post-processing is performed, thus obtaining the multi-layer composite extruded rubber pipe.

[0079] The inner rubber layer is extruded using an extruder, and the temperature of the extruder from the die head to the screw is 100 DEG C, 70 DEG C, 70 DEG C, 60 DEG C and 60 DEG C in sequence.

[0080] The aramid yarn 2520 dtex is knitted by using a 10-needle knitting machine.

[0081] The spraying amount of the silicone oil is 10 mL / cm 2 .

[0082] The electron irradiation treatment condition is: electron beam energy 5 MeV, irradiation dose 80 kGy.

[0083] The post-treatment includes: core rod penetration, vulcanization at 170 DEG C for 30 minutes, and cutting.

[0084] Example 4 A preparation method of a multi-layer composite extruded rubber pipe, comprising the following steps: (1) first, zirconium acetylacetonate, polysilazane, polydimethylsiloxane, carbon nanofiber are used as raw materials to prepare zirconium-doped silicon carbide / nitride fiber; The specific method is: first, zirconium acetylacetonate, polysilazane, carbon nanofiber are uniformly mixed to obtain a mixture, then polydimethylsiloxane is uniformly coated on the surface of the mixture, heated, dissolved in xylene, filtered, distilled under reduced pressure, to obtain a mixture, then the mixture is placed in a melt spinning cylinder, heated to melt under nitrogen atmosphere, pressurized, the melt flows through the filter screen and the spinneret plate to obtain a fiber bundle, heated and crosslinked, sintered, and crushed to below 1 μm to obtain the zirconium-doped silicon carbide / nitride fiber.

[0085] The mass ratio of zirconium acetylacetonate, polysilazane, carbon nanofiber and polydimethylsiloxane is 10:1.5:0.06:115; the particle size of the carbon nanofiber is 60 nm, and the length is 8 μm.

[0086] The process conditions of the heating treatment are: heating at 22 DEG C / min to 190 DEG C, and keeping for 2 hours.

[0087] Heating to melt at 0.6 DEG C / min, and pressurizing to 4 MPa.

[0088] The heating crosslinking condition is: heating crosslinking at 340 DEG C for 5 hours.

[0089] The sintering conditions are as follows: first, ammonia gas is passed at 320 mL / min, heating to 550℃ at 60℃ / min, and holding for 2 hours; then, heating to 850℃ at the same heating rate, and holding for 2 hours; then, argon gas is passed at 150 mL / min, heating to 1450℃ at 25℃ / min, and holding for 1.5 hours; then, air is passed at 150 mL / min, and holding for 1.5 hours, and then cooling in the furnace.

[0090] (2) The zirconium-doped silicon carbide / boron nitride fiber is modified by using γ-methacryloxypropyl trimethoxysilane to obtain a modified fiber; Specifically, the zirconium-doped silicon carbide / boron nitride fiber is dispersed in anhydrous ethanol by stirring, heated to reflux, and held for 25 minutes of stirring, then γ-methacryloxypropyl trimethoxysilane is added, and the stirring is continued for 85 minutes of holding, the precipitate is taken by centrifugation, and dried to obtain the modified fiber; the mass ratio of the zirconium-doped silicon carbide / boron nitride fiber, the anhydrous ethanol, and the γ-methacryloxypropyl trimethoxysilane is 1:3.5:0.02.

[0091] (3) Then, the modified fiber is used as a raw material to react with an acrylate monomer to obtain a polyacrylate modified fiber; Specifically, the modified fiber, the acrylate monomer, water, an initiator, and a crosslinking agent are uniformly mixed, heated to 70℃ under a nitrogen atmosphere, and held for 5 hours of stirring, the solid is taken by filtration, washed with water, dried, and pulverized to below 1 μm to obtain the polyacrylate modified fiber; the mass ratio of the modified fiber, the acrylate monomer, water, the initiator, and the crosslinking agent is 1:0.9:4.5:0.01:0.01.

[0092] The acrylate monomer is n-butyl methacrylate; the initiator is azobis isobutyronitrile; and the crosslinking agent is allyl acrylate.

[0093] (4) An acrylate rubber and the polyacrylate modified fiber are used as main raw materials to mix and obtain a rubber compound; The formula of the rubber compound is as follows: acrylate rubber 10 kg, polyacrylate modified fiber 0.8 kg, stearic acid 0.15 kg, carbon black 4 kg, adipic acid diester 0.7 kg, stearyl alcohol polyether-2 phosphate 0.07 kg, 4,4-bis (α, α-dimethylphenyl) diphenylamine 0.15 kg, hexamethylene diamine carbamate 0.15 kg, and diphenyl guanidine 0.15 kg.

[0094] The mixing method is as follows: Add the formulated amounts of acrylate rubber, polyacrylate modified fiber, stearic acid, carbon black, adipate, stearyl alcohol polyether-2-phosphate, and 4,4-bis(α,α-dimethylphenyl)diphenylamine to a mixer for mixing. When the temperature reaches 115℃, discharge the material, cool it, and put it back into the mixer. Add hexamethylenediamine carbamate and diphenylguanidine, and continue mixing until the temperature reaches 108℃. Then discharge the material and cool it.

[0095] (5) The inner rubber layer is extruded using rubber material, and an aramid yarn is used to knit a reinforcing layer on the surface of the inner rubber layer. Silicone oil is sprayed evenly on the surface of the reinforcing layer, and electron irradiation is performed. The outer rubber layer is extruded using rubber material, and then post-processed to obtain the multi-layer composite extruded rubber tube.

[0096] When extruding the inner rubber layer using an extruder, the extruder temperatures from the die head to the screw are 95℃, 75℃, 75℃, 55℃, and 55℃, respectively. When extruding the outer rubber layer using an extruder, the extruder temperatures from the die head to the screw are 95℃, 75℃, 75℃, 55℃, and 55℃, respectively.

[0097] The 2520 tex aramid yarn is knitted using a 10-needle knitting machine.

[0098] The spraying rate of silicone oil is 9 mL / cm². 2 .

[0099] The electron irradiation treatment conditions were: electron beam energy 6 MeV and irradiation dose 75 kGy.

[0100] Post-processing includes: core rod insertion, vulcanization at 175°C for 25 minutes, and cutting.

[0101] Comparative Example 1 A method for preparing a multilayer composite extruded hose includes the following steps: (1) Silicon carbide / boron nitride fibers were prepared using polyborosilazane, polydimethylsiloxane and carbon nanofibers as raw materials. The specific method is as follows: First, polyboron silazane and carbon nanofibers are mixed evenly to obtain a mixture. Then, polydimethylsiloxane is evenly coated on the surface of the mixture, heated, dissolved in xylene, filtered, and distilled under reduced pressure to obtain a mixture. Then, the mixture is placed in a melt spinning cylinder, heated to melt under a nitrogen atmosphere, pressurized, and the melt flows out through a filter screen and spinneret to obtain a fiber bundle. The bundle is then heated for cross-linking, sintered, and pulverized to below 1 μm to obtain the silicon carbide / boron nitride fiber.

[0102] The mass ratio of polyborosilazane, carbon nanofibers, and polydimethylsiloxane is 1:0.05:110; the carbon nanofibers have a particle size of 50 nm and a length of 5 μm.

[0103] The process condition of the heating treatment is: heating to 180℃ at 20℃ / min, and keeping for 2 hours.

[0104] Heating to melt at 0.5℃ / min, and pressurizing to 3MPa.

[0105] The heating cross-linking condition is: heating cross-linking at 330℃ for 4 hours.

[0106] The sintering condition is: first, passing ammonia gas at 300mL / min, heating to 500℃ at 50℃ / min, and keeping for 2 hours; then, heating to 800℃ at the same heating rate, and keeping for 2 hours; again, passing argon gas at 100mL / min, heating to 1400℃ at 20℃ / min, and keeping for 1 hour; then, passing air at 100mL / min, continuing to keep for 1 hour, and cooling in the furnace.

[0107] (2) The silicon carbide / boron nitride fiber is modified by using γ-methacryloxypropyl trimethoxysilane to obtain a modified fiber; The specific method is: the silicon carbide / boron nitride fiber is stirred and dispersed in anhydrous ethanol, heated to reflux, kept for 20 minutes, then γ-methacryloxypropyl trimethoxysilane is added, and kept for 80 minutes, the precipitate is obtained by centrifugation, and dried.

[0108] (3) Then, the modified fiber is used as raw material to react with an acrylate monomer to obtain a polyacrylate modified fiber; The specific method is: the modified fiber is mixed with an acrylate monomer, water, an initiator, and a cross-linking agent, heated to 65℃ under nitrogen atmosphere, kept for 5 hours, the solid is obtained by filtration, washed with water, dried, and pulverized to below 1μm; the mass ratio of the modified fiber, the acrylate monomer, water, the initiator, and the cross-linking agent is 1:0.8:4:0.01:0.01.

[0109] The acrylate monomer is butyl acrylate; the initiator is azobis isobutyronitrile; and the cross-linking agent is allyl acrylate.

[0110] (4) An acrylate rubber and the polyacrylate modified fiber are used as main raw materials to mix and obtain a rubber compound; The formula of the rubber compound is as follows: acrylate rubber 10kg, polyacrylate modified fiber 0.7kg, stearic acid 0.1kg, carbon black 3kg, adipic acid diester 0.5kg, stearyl alcohol polyether-2 phosphate 0.05kg, 4,4-bis (α, α-dimethylphenyl) diphenylamine 0.1kg, hexamethylene diamine carbamate 0.1kg, and diphenyl guanidine 0.1kg.

[0111] The mixing method is as follows: the formula amount of acrylate rubber, polyacrylate modified fiber, stearic acid, carbon black, adipic acid diester, stearyl alcohol polyether-2 phosphate, 4, 4-bis (α, α-dimethylphenyl) diphenylamine is added to the internal mixer for mixing, when the temperature reaches 110℃, the material is discharged, cooled, recharged into the internal mixer, and adipic acid diamine carbamate, diphenyl guanidine is added, and the mixing is continued until the temperature reaches 100℃, the material is discharged, and cooled.

[0112] (5) The inner rubber layer is extruded by using the rubber material, the reinforcing layer is formed by using aramid wire knitting on the surface of the inner rubber layer, the surface of the reinforcing layer is uniformly sprayed with silicone oil, electron irradiation treatment is carried out, the outer rubber layer is extruded by using the rubber material, and post-treatment is carried out, so that the multi-layer composite extruded rubber pipe is obtained.

[0113] The inner rubber layer is extruded by using the extruder, and the temperature of the extruder from the head to the screw is 100℃, 80℃, 80℃, 60℃ and 60℃ in sequence; the outer rubber layer is extruded by using the extruder, and the temperature of the extruder from the head to the screw is 100℃, 80℃, 80℃, 60℃ and 60℃ in sequence.

[0114] The aramid wire 2520 is 10 needles, and knitting is realized by using a 10-needle knitting machine.

[0115] The spraying amount of silicone oil is 8 mL / cm 2 .

[0116] The electron irradiation treatment condition is that the electron beam energy is 5 MeV, and the irradiation dose is 70 kGy.

[0117] The post-treatment includes: core rod penetration, vulcanization at 170℃ for 20 minutes, and cutting.

[0118] Comparative example 2 A preparation method of a multi-layer composite extruded rubber pipe comprises the following steps: (1) Zirconium-doped silicon carbide / boron nitride fibers are prepared by using zirconium acetylacetonate, polysilazane, polydimethylsiloxane and carbon nanofiber as raw materials; The specific method is as follows: first, zirconium acetylacetonate, polysilazane and carbon nanofiber are uniformly mixed to obtain a mixture, then polydimethylsiloxane is uniformly coated on the surface of the mixture, heated, dissolved in xylene, filtered, and distilled under reduced pressure to obtain a mixed material, and then the mixed material is placed in a melt spinning cylinder, heated to melt under a nitrogen atmosphere, pressurized, and the melt flows through a filter screen and a spinneret plate to form a fiber bundle, which is heated, crosslinked, sintered and crushed to less than 1 μm to obtain the zirconium-doped silicon carbide / boron nitride fibers.

[0119] The mass ratio of zirconium acetylacetonate, polysilazane, carbon nanofiber and polydimethylsiloxane is 10:1:0.05:110; the particle size of the carbon nanofiber is 50 nm, and the length is 5 μm.

[0120] The process condition of the heating treatment is: heating to 180℃ at 20℃ / min, and holding for 2 hours.

[0121] Heating to melt at 0.5℃ / min, and pressurizing to 3MPa.

[0122] The heating cross-linking condition is: heating cross-linking at 330℃ for 4 hours.

[0123] The sintering condition is: first, passing ammonia gas at 300mL / min, heating to 500℃ at 50℃ / min, and holding for 2 hours; then, heating to 800℃ at the same heating rate, and holding for 2 hours; again, passing argon gas at 100mL / min, heating to 1400℃ at 20℃ / min, and holding for 1 hour; then, passing air at 100mL / min, continuing to hold for 1 hour, and cooling in the furnace.

[0124] (2) Then, the zirconium-doped silicon carbide / boron nitride fiber is used as raw material to react with an acrylate monomer to obtain a polyacrylate modified fiber; The specific method is: the zirconium-doped silicon carbide / boron nitride fiber is uniformly mixed with an acrylate monomer, water, an initiator, and a cross-linking agent, heated to 65℃ under a nitrogen atmosphere, and held for 5 hours of stirring, then the solid is filtered, washed with water, dried, and pulverized to below 1μm; the mass ratio of the zirconium-doped silicon carbide / boron nitride fiber, the acrylate monomer, the water, the initiator, and the cross-linking agent is 1:0.8:4:0.01:0.01.

[0125] The acrylate monomer is butyl acrylate; the initiator is azobisisobutyronitrile; and the cross-linking agent is allyl acrylate.

[0126] (3) The acrylate rubber and the polyacrylate modified fiber are used as main raw materials to mix and obtain a rubber compound. The formula of the rubber compound is as follows: acrylate rubber 10kg, polyacrylate modified fiber 0.7kg, stearic acid 0.1kg, carbon black 3kg, adipic acid diester 0.5kg, stearyl alcohol polyether-2 phosphate 0.05kg, 4,4-bis(α,α-dimethylphenyl)diphenylamine 0.1kg, hexamethylene diamine carbamate 0.1kg, and diphenyl guanidine 0.1kg.

[0127] The mixing method is as follows: the formula amount of acrylate rubber, polyacrylate modified fiber, stearic acid, carbon black, adipic acid diester, stearyl alcohol polyether-2 phosphate, 4,4-bis(α,α-dimethylphenyl)diphenylamine are added into a mixing machine to mix, when the temperature reaches 110℃, the material is discharged, cooled, again added into the mixing machine, and hexamethylene diamine carbamate and diphenyl guanidine are added to continue mixing until the temperature reaches 100℃, the material is discharged, and cooled.

[0128] (4) using the rubber extrusion inner rubber layer, using aramid yarn knitting on the surface of the inner rubber layer to form a reinforcing layer, spraying silicon oil on the surface of the reinforcing layer, electronic irradiation treatment, using rubber extrusion outer rubber layer, post-processing, thus obtaining the multi-layer composite extruded rubber pipe.

[0129] The inner rubber layer is extruded using an extruder, and the temperature of the extruder from the head to the screw is 100℃, 80℃, 80℃, 60℃, and 60℃ in sequence.

[0130] The aramid yarn 2520 dtex is knitted using a 10-needle knitting machine.

[0131] The spraying amount of silicon oil is 8 mL / cm. 2 .

[0132] The electronic irradiation treatment condition is: electron beam energy 5 MeV, irradiation dose 70 kGy.

[0133] The post-processing includes: core rod, vulcanization at 170℃ for 20 minutes, and cutting.

[0134] Comparative Example 3 A preparation method of a multi-layer composite extruded rubber pipe, comprising the following steps: (1) first, zirconium acetylacetonate, polysilazane, polydimethylsiloxane, and carbon nanofiber are used as raw materials to prepare zirconium-doped silicon carbide / boron nitride fiber; The specific method is: first, zirconium acetylacetonate, polysilazane, and carbon nanofiber are uniformly mixed to obtain a mixture, then polydimethylsiloxane is uniformly coated on the surface of the mixture, heated, dissolved in xylene, filtered, and distilled under reduced pressure to obtain a mixture, and then the mixture is placed in a melt spinning cylinder, heated to melt under a nitrogen atmosphere, pressurized, and the melt flows through a filter screen and a spinneret plate to obtain a fiber bundle, which is heated, crosslinked, sintered, and crushed to below 1 μm, thus obtaining the zirconium-doped silicon carbide / boron nitride fiber.

[0135] The mass ratio of zirconium acetylacetonate, polysilazane, carbon nanofiber, and polydimethylsiloxane is 10:1:0.05:110; the particle size of the carbon nanofiber is 50 nm, and the length is 5 μm.

[0136] The process conditions for the heating treatment are: heating at 20℃ / min to 180℃, and keeping for 2 hours.

[0137] Heating to melt at 0.5℃ / min, and pressurizing to 3 MPa.

[0138] The heating crosslinking condition is: heating crosslinking at 330℃ for 4 hours.

[0139] The sintering conditions are as follows: first, ammonia gas is passed at a flow rate of 300 mL / min, and heating is performed at a rate of 50 ℃ / min to 500 ℃, and then the temperature is kept for 2 hours; then, heating is performed at the same rate to 800 ℃, and then the temperature is kept for 2 hours; then, argon gas is passed at a flow rate of 100 mL / min, and heating is performed at a rate of 20 ℃ / min to 1400 ℃, and then the temperature is kept for 1 hour; then, air is passed at a flow rate of 100 mL / min, and the temperature is kept for 1 hour, and then the furnace is cooled.

[0140] (2) The zirconium-doped silicon carbide / boron nitride fiber is modified by using γ-methacryloxypropyl trimethoxysilane to obtain a modified fiber; Specifically, the zirconium-doped silicon carbide / boron nitride fiber is dispersed in anhydrous ethanol by stirring, heated to reflux, and kept for 20 minutes of stirring, then γ-methacryloxypropyl trimethoxysilane is added, and the temperature is kept for 80 minutes of stirring, the precipitate is obtained by centrifugation, and then dried.

[0141] (3) Then, the modified fiber is used as a raw material to react with an acrylate monomer to obtain a polyacrylate modified fiber; Specifically, the modified fiber, the acrylate monomer, water, an initiator, and a crosslinking agent are uniformly mixed, heated to 65 ℃ under a nitrogen atmosphere, and kept for 5 hours of stirring, and then the solid is obtained by filtration, washed with water, dried, and pulverized to less than 1 μm.

[0142] The acrylate monomer is butyl acrylate, the initiator is azobisisobutyronitrile, and the crosslinking agent is allyl acrylate.

[0143] (4) An acrylate rubber and the polyacrylate modified fiber are used as main raw materials to mix and obtain a rubber compound; The rubber compound has the following formula: 10 kg of acrylate rubber, 0.7 kg of polyacrylate modified fiber, 0.1 kg of stearic acid, 3 kg of carbon black, 0.5 kg of adipic acid diester, 0.05 kg of stearyl alcohol polyether-2 phosphate, 0.1 kg of 4,4-bis (α, α-dimethylphenyl) diphenylamine, 0.1 kg of hexamethylene diamine carbamate, and 0.1 kg of diphenyl guanidine.

[0144] The mixing method is as follows: the formula amount of acrylate rubber, polyacrylate modified fiber, stearic acid, carbon black, adipic acid diester, stearyl alcohol polyether-2 phosphate, 4, 4-bis (α, α-dimethylphenyl) diphenylamine are added into the mixing machine for mixing, when the temperature reaches 110℃, discharge, cool down, put into the mixing machine again, and add adipamide, diphenyl guanidine, continue to mix until the temperature reaches 100℃, discharge, cool down.

[0145] (5) The inner rubber layer is extruded by using a rubber material, the reinforcing layer is formed by using aramid yarn knitting on the surface of the inner rubber layer, the outer rubber layer is extruded by using a rubber material, and the post-processing is performed, thereby obtaining the multi-layer composite extruded rubber pipe.

[0146] The inner rubber layer is extruded by using an extruder, and the temperature of the extruder from the head to the screw is 100℃, 80℃, 80℃, 60℃ and 60℃ in sequence; the outer rubber layer is extruded by using an extruder, and the temperature of the extruder from the head to the screw is 100℃, 80℃, 80℃, 60℃ and 60℃ in sequence.

[0147] The aramid yarn 2520 dtex is knitted by using a 10-needle knitting machine.

[0148] The post-processing includes: threading the mandrel, vulcanizing at 170℃ for 20 minutes, and cutting.

[0149] Test example The rubber pipes (inner diameter 50mm x 4mm x 300mm) obtained in Examples 1-4 and Comparative Examples 1-3 are respectively taken for performance testing: 1. The pressure resistance test is performed according to ISO1402.

[0150] 2. The air pressure alternating pulse test is performed by using an air pressure alternating pulse tester (Simit). The test medium is water, the pulse pressure is 50MPa, the pulse frequency is 20 times / min, and the room temperature.

[0151] 3. The compression permanent deformation test is performed by using a rubber compression permanent deformation tester (Beijing Zhongke Luda Test Instrument Co., Ltd.).

[0152] The test results are shown in Table 1.

[0153] Table 1. Performance test of rubber pipe As shown in Table 1, the rubber pipes obtained in Examples 1-4 have excellent pressure resistance, fatigue resistance and elasticity, which meet the working requirements of turbocharger rubber pipes.

[0154] The performance of each of the comparative examples 1 to 3 is obviously deteriorated, which indicates that the compatibility of the zirconium-doped silicon carbide / boron nitride fiber prepared according to the present application with the rubber matrix is modified, and the silicon oil spraying and the synergistic effect between the multi-layer structure are cooperated to improve the performance of the rubber tube.

[0155] The present application is illustrated by the above examples, but the present application is not limited to the above examples, i.e. it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of individual raw materials of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for preparing a multilayer composite extruded hose, characterized in that, Includes the following steps: (1) Zirconium-doped silicon carbide / boron nitride fibers were prepared using zirconium acetylacetonate, polyborosilazane, polydimethylsiloxane, and carbon nanofibers as raw materials. (2) The zirconium-doped silicon carbide / boron nitride fibers are then modified with γ-methacryloyloxypropyltrimethoxysilane to obtain modified fibers; (3) Then, the modified fiber and acrylate monomers are reacted to obtain polyacrylate modified fiber; (4) Using acrylate rubber and polyacrylate modified fiber as the main raw materials, the mixture is compounded to obtain the rubber compound; (5) The inner rubber layer is extruded using rubber material, and an aramid yarn is used to knit a reinforcing layer on the surface of the inner rubber layer. Silicone oil is sprayed evenly on the surface of the reinforcing layer, and electron irradiation is performed. The outer rubber layer is extruded using rubber material, and then post-processed to obtain the multi-layer composite extruded rubber tube.

2. The preparation method according to claim 1, characterized in that, The specific method of step (1) is as follows: First, zirconium acetylacetonate, polyborosilazane, and carbon nanofibers are mixed evenly to obtain a mixture. Then, polydimethylsiloxane is evenly covered on the surface of the mixture, heated, dissolved in xylene, filtered, and distilled under reduced pressure to obtain a mixture. Then, the mixture is placed in a melt spinning cylinder, heated to melt under a nitrogen atmosphere, pressurized, and the melt flows out through a filter screen and a spinneret to obtain a fiber bundle. The bundle is then heated for cross-linking, sintered, and pulverized to below 1 μm to obtain the zirconium-doped silicon carbide / boron nitride fiber.

3. The preparation method according to claim 2, characterized in that, The mass ratio of zirconium acetylacetonate, polyborosilazane, carbon nanofibers, and polydimethylsiloxane is 10:1-2:0.05-0.07:110-120; the carbon nanofibers have a particle size of 50-70 nm and a length of 5-10 μm. The heat treatment process conditions are as follows: heat to 180-200℃ at a rate of 20-25℃ / min, and hold for 2-3 hours; Heat at 0.5–0.7 °C / min until melted, and pressurize to 3–5 MPa; The heating crosslinking conditions are: heating at 330–350℃ for 4–6 hours; The sintering conditions are as follows: First, purge with ammonia gas at 300-350 mL / min and heat to 500-600℃ at 50-70℃ / min, holding for 2-3 hours; then heat to 800-900℃ at the same heating rate and hold for 2-3 hours; next, purge with argon gas at 100-200 mL / min and heat to 1400-1500℃ at 20-30℃ / min, holding for 1-2 hours; then purge with air at 100-200 mL / min and continue holding for 1-2 hours, then cool with the furnace.

4. The preparation method according to claim 1, characterized in that, The specific method for step (2) is as follows: Zirconium-doped silicon carbide / boron nitride fibers are stirred and dispersed in anhydrous ethanol, heated to reflux, and stirred for 20-30 minutes. Then, γ-methacryloyloxypropyltrimethoxysilane is added, and stirred for another 80-90 minutes. The precipitate is then centrifuged and dried. The mass ratio of zirconium-doped silicon carbide / boron nitride fibers, anhydrous ethanol, and γ-methacryloyloxypropyltrimethoxysilane is 1:3-4:0.02-0.

03.

5. The preparation method according to claim 1, characterized in that, The specific method of step (3) is as follows: Mix the modified fiber with acrylate monomers, water, initiator and crosslinking agent evenly, heat to 65-75°C under nitrogen atmosphere, keep warm and stir for 5-6 hours, filter to take solid, wash with water, dry, and pulverize to below 1μm; The mass ratio of modified fiber to acrylate monomer, water, initiator, and crosslinking agent is 1:0.8-1:4-5:0.01-0.02:0.01-0.

02.

6. The preparation method according to claim 1, characterized in that, In step (4), the composition of the rubber compound by weight is as follows: 10 parts acrylate rubber, 0.7-0.9 parts polyacrylate modified fiber, 0.1-0.2 parts stearic acid, 3-5 parts carbon black, 0.5-1 parts adipate, 0.05-0.1 parts stearyl alcohol polyether-2 phosphate, 0.1-0.2 parts 4,4-bis(α,α-dimethylphenyl)diphenylamine, 0.1-0.2 parts hexamethylenediamine carbamate, and 0.1-0.2 parts diphenylguanidine.

7. The preparation method according to claim 1, characterized in that, In step (4), the mixing method is as follows: Add the formulated amounts of acrylate rubber, polyacrylate modified fiber, stearic acid, carbon black, adipate, stearyl alcohol polyether-2 phosphate, and 4,4-bis(α,α-dimethylphenyl)diphenylamine to a mixer for mixing. When the temperature reaches 110-120℃, discharge the material, cool it, and put it back into the mixer. Add hexamethylenediamine carbamate and diphenylguanidine, and continue mixing until the temperature reaches 100-110℃. Then discharge the material and cool it.

8. The preparation method according to claim 1, characterized in that, In step (5), the inner rubber layer is extruded using an extruder, and the extruder temperature from the die head to the screw is as follows: 100~90℃, 80~70℃, 80~70℃, 60~50℃, 60~50℃; the outer rubber layer is extruded using an extruder, and the extruder temperature from the die head to the screw is as follows: 100~90℃, 80~70℃, 80~70℃, 60~50℃, 60~50℃. The aramid yarn is 2520 tex and is knitted using a 10-needle knitting machine. The spraying rate of silicone oil is 8–10 mL / cm². 2 ; The electron irradiation treatment conditions are: electron beam energy 5-7 MeV, irradiation dose 70-80 kGy; Post-processing includes: core rod insertion, vulcanization at 170-180℃ for 20-30 minutes, and cutting.

9. A multi-layer composite extruded hose, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 8.

10. The application of the multilayer composite extruded hose of claim 9 in the preparation of turbocharger intake hose.

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