An oil-resistant hydraulic brake hose and its preparation method

Abstract

This invention relates to the field of rubber materials technology, and proposes an oil-resistant hydraulic brake hose and its preparation method. An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer. The inner rubber layer comprises the following components by weight: 70-80 parts nitrile rubber, 2-3 parts silane coupling agent, 4-6 parts zinc oxide, 2-3 parts stearic acid, 1-2 parts flow aid, 5-10 parts tackifier, 10-20 parts plasticizer, 0.8-1.5 parts sulfur, 3-5 parts accelerator, 60-75 parts carbon black, 10-15 parts silica, and 8-15 parts composite pyrophyllite. The composite pyrophyllite is obtained by modifying pyrophyllite with octyltrimethoxysilane and then compounding it with 1-butyl-3-methylimidazolium hexafluorophosphate. This technical solution solves the problem of poor oil resistance of the inner rubber layer in existing hydraulic brake hoses.

Description

Technical Field

[0001] This invention relates to the field of rubber materials technology, specifically to an oil-resistant hydraulic brake hose and its preparation method. Background Technology

[0002] As a core force-transmitting component of the automotive braking system, the service safety of hydraulic brake hoses directly depends on the oil resistance of the inner rubber layer. As a key structure that comes into direct contact with mineral oil, the inner rubber layer needs to resist the swelling and erosion of oil for a long time, while also withstanding the pressure cycles and alternating high and low temperatures of the braking system. Therefore, improving the oil resistance of the inner rubber layer has become a core technical challenge that the industry urgently needs to overcome.

[0003] Currently, to ensure the oil resistance of the inner rubber layer, existing technologies often use nitrile rubber as the matrix material. Furthermore, to further improve the oil resistance of the inner rubber layer, existing technologies often add layered silicate fillers such as pyrophyllite, utilizing their lamellar structure to extend the penetration path of oil molecules. However, unmodified pyrophyllite has a large number of hydroxyl groups on its surface, exhibiting strong hydrophilicity and poor compatibility with hydrophobic rubber matrices such as nitrile rubber. This leads to agglomeration, making it difficult to fully utilize its layered barrier advantages and potentially even causing a decrease in the mechanical properties of the rubber compound. Therefore, there is an urgent need for an oil-resistant hydraulic brake hose. Summary of the Invention

[0004] This invention proposes an oil-resistant hydraulic brake hose and its preparation method, which solves the problem of poor oil resistance of the inner rubber layer of hydraulic brake hoses in related technologies.

[0005] The technical solution of the present invention is as follows: This invention proposes an oil-resistant hydraulic brake hose, which comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer. The inner rubber layer comprises the following components by weight: 70-80 parts of nitrile rubber, 2-3 parts of silane coupling agent, 4-6 parts of zinc oxide, 2-3 parts of stearic acid, 1-2 parts of flow aid, 5-10 parts of tackifier, 10-20 parts of plasticizer, 0.8-1.5 parts of sulfur, 3-5 parts of accelerator, 60-75 parts of carbon black, 10-15 parts of silica, and 8-15 parts of composite pyrophyllite. The composite pyrophyllite is obtained by modifying pyrophyllite with octyltrimethoxysilane and then combining it with 1-butyl-3-methylimidazolium hexafluorophosphate.

[0006] As a further technical solution, the preparation method of the composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, adjust the pH to 4-5, add octyltrimethoxysilane, stir, filter, and dry to obtain silane-modified pyrophyllite; A2. The silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice, filtered, and dried to obtain composite pyrophyllite.

[0007] As a further technical solution, the mass-to-volume ratio of pyrophyllite to water is 1g:100mL.

[0008] As a further technical solution, the mass-to-volume ratio of pyrophyllite and methanol is 1g:20mL.

[0009] As a further technical solution, the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate is 1:0.1:0.2~0.28.

[0010] In this invention, by further optimizing the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate to 1:0.1:0.2~0.28, the oil resistance of the inner rubber layer of the hydraulic brake hose is further improved.

[0011] As a further technical solution, the temperatures of the stirring and the secondary stirring are each independently 60~70℃; The stirring time is 1 to 1.5 hours; the secondary stirring time is 5 to 6 hours.

[0012] As a further technical solution, the nitrile rubber is composed of a first nitrile rubber and a second nitrile rubber; the acrylonitrile content of the first nitrile rubber and the second nitrile rubber is different.

[0013] As a further technical solution, the acrylonitrile content of the first nitrile rubber is 40.5 wt%; the acrylonitrile content of the second nitrile rubber is 28 wt%.

[0014] In this invention, by compounding a first nitrile rubber with an acrylonitrile content of 40.5 wt% and a second nitrile rubber with an acrylonitrile content of 28 wt%, the oil resistance of the inner rubber layer of the hydraulic brake hose can be guaranteed while improving its elongation at break. The 40.5 wt% high-nitrile first nitrile rubber, with its high-density acrylonitrile groups, has a strong polar barrier effect against oil, but its strong intermolecular dipole interactions and high chain rigidity result in a relatively low elongation at break. The 28 wt% medium-nitrile second nitrile rubber, while retaining a certain degree of oil resistance, has better chain flexibility and elongation at break due to its higher butadiene segment content. After compounding, the high-nitrile first nitrile rubber maintains its oil resistance, while the medium-nitrile second nitrile rubber fills the gaps between the high-nitrile rubber molecules to weaken the strong intermolecular interactions and improve the overall chain mobility, thus synergistically improving the elongation at break of the inner rubber layer of the hydraulic brake hose.

[0015] As a further technical solution, the mass ratio of the first nitrile rubber to the second nitrile rubber is 1:2~3.

[0016] As a further technical solution, the middle rubber layer comprises the following components by weight: 20-30 parts natural rubber, 40-50 parts styrene-butadiene rubber, 6-8 parts plasticizer, 4-6 parts zinc oxide, 2-3 parts stearic acid, 1.5-2.5 parts sulfur, 2.4-4 parts accelerator, 50-70 parts carbon black, and 10-20 parts silica.

[0017] As a further technical solution, the outer rubber layer comprises the following components in parts by weight: 100 parts of EPDM rubber, 2-4 parts of silane coupling agent, 5-7 parts of zinc oxide, 1-2 parts of stearic acid, 1-2 parts of flow aid, 5-10 parts of tackifier, 8-12 parts of plasticizer, 0.5-1.5 parts of sulfur, 3-5 parts of accelerator, 60-80 parts of carbon black, and 15-25 parts of silica.

[0018] As a further technical solution, the flow aids in the inner and outer adhesive layers each independently include one or two of polyethylene wax and calcium stearate.

[0019] As a further technical solution, the tackifier includes terpene resin.

[0020] As a further technical solution, the plasticizers in the inner layer, middle layer and outer layer components each independently include one or two of dioctyl adipate and dioctyl sebacate.

[0021] As a further technical solution, the accelerators in the inner layer, middle layer and outer layer components are each independently accelerator CZ and accelerator M.

[0022] As a further technical solution, the first reinforcing layer and the second reinforcing layer are each independently woven from vinylon yarn.

[0023] This invention also proposes a method for preparing an oil-resistant hydraulic brake hose, comprising the following steps: S1. Mix the nitrile rubber, silane coupling agent, zinc oxide, stearic acid and flow aid in the inner rubber layer component, add carbon black, silica, composite pyrophyllite, plasticizer and tackifier and mix, then add sulfur and accelerator and continue mixing to obtain the inner rubber layer compound. S2. Mix the natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add plasticizer, carbon black and silica and mix, then add sulfur and accelerator and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent, zinc oxide, stearic acid and flow aid in the outer rubber layer components, add carbon black, silica, plasticizer and tackifier and mix, then add sulfur and accelerator and continue mixing to obtain the outer rubber layer compound. S4. The inner rubber layer material is extruded and coated onto the mandrel to obtain the inner rubber layer. Vinylon yarn is braided onto the inner rubber layer to obtain the first reinforcing layer. The middle rubber layer material is extruded and coated onto the first reinforcing layer to obtain the middle rubber layer. Vinylon yarn is braided onto the middle rubber layer to obtain the second reinforcing layer. The outer rubber layer material is extruded and coated onto the second reinforcing layer, vulcanized, and decored to obtain the oil-resistant hydraulic brake hose.

[0024] The working principle and beneficial effects of this invention are as follows: In this invention, the oil resistance of the inner rubber layer of a hydraulic brake hose can be improved by adding composite pyrophyllite obtained by modifying it with octyltrimethoxysilane and then compounding it with 1-butyl-3-methylimidazolium hexafluorophosphate. Pyrophyllite's lamellar structure has a large specific surface area and good barrier properties. This invention first uses octyltrimethoxysilane to modify the surface of pyrophyllite, grafting hydrophobic long-chain octyl groups onto the pyrophyllite lamellar surface, effectively reducing the hydrophilicity of pyrophyllite and initially improving its dispersibility. Based on this, the modified pyrophyllite is further compounded with 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid. Firstly, the polarity of this ionic liquid increases the compatibility of pyrophyllite with nitrile rubber and resists the penetration of non-polar oil into the inner rubber layer. Simultaneously, the ionic liquid acts as a lubricant, further improving the dispersion of pyrophyllite lamellars in the rubber matrix, reducing lamellar agglomeration, and the uniformly dispersed pyrophyllite lamellars can extend the penetration path of oil molecules. Therefore, composite pyrophyllite can synergistically improve the oil resistance of the inner rubber layer of hydraulic brake hoses by both extending the permeation path and resisting permeation. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] In the following examples and comparative examples, the EPDM rubber is model 3640; the natural rubber is model SCR20; the styrene-butadiene rubber is model 1500; the first nitrile butadiene rubber is model 1051M35; the second nitrile butadiene rubber is model 2845; the third nitrile butadiene rubber is model 1965; the terpene resin is model TR-90; the average particle size of the silica is 6 μm; and the pyrophyllite has a mesh size of 600 mesh.

[0027] Example 1 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 70 parts nitrile rubber, 2 parts silane coupling agent KH550, 4 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 5 parts terpene resin, 10 parts dioctyl adipate, 0.8 parts sulfur, 1.5 parts accelerator CZ, 1.5 parts accelerator M, 60 parts carbon black N550, 10 parts silica, and 8 parts composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 2 parts silane coupling agent KH550, 5 parts zinc oxide, 1 part stearic acid, 1 part polyethylene wax, 5 parts terpene resin, 20 parts dioctyl adipate, 0.5 parts sulfur, 1.5 parts accelerator CZ, 1.5 parts accelerator M, 60 parts carbon black N550, and 15 parts silica. The middle layer comprises the following components by weight: 20 parts natural rubber, 40 parts styrene-butadiene rubber, 6 parts dioctyl adipate, 4 parts zinc oxide, 2 parts stearic acid, 1.5 parts sulfur, 1.2 parts accelerator CZ, 1.2 parts accelerator M, 50 parts carbon black N754, and 10 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 4, add octyltrimethoxysilane, stir at 60℃ for 1.5h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1g:100mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 60℃ for 6 hours, filtered, and dried to obtain composite pyrophyllite, wherein the mass-volume ratio of pyrophyllite to methanol was 1 g:20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.15; A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid and polyethylene wax in the inner rubber layer component, add dioctyl adipate, terpene resin, carbon black N550, white carbon black and composite pyrophyllite and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix the natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, and polyethylene wax in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0028] Example 2 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 5, add octyltrimethoxysilane, stir at 70℃ for 1 h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1 g: 100 mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 hours, filtered, and dried to obtain composite pyrophyllite. The mass-to-volume ratio of pyrophyllite to methanol was 1 g:20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane, and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.15. A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0029] Example 3 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 75 parts nitrile rubber, 2.5 parts silane coupling agent KH550, 5 parts zinc oxide, 2.5 parts stearic acid, 1.5 parts calcium stearate, 8 parts terpene resin, 15 parts dioctyl sebacate, 1 part sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 65 parts carbon black N550, 12 parts silica, and 12 parts composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 3 parts silane coupling agent KH550, 6 parts zinc oxide, 1.5 parts stearic acid, 1.5 parts calcium stearate, 8 parts terpene resin, 25 parts dioctyl sebacate, 1 part sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N550, and 20 parts silica. The middle layer comprises the following components by weight: 25 parts natural rubber, 45 parts styrene-butadiene rubber, 7 parts dioctyl sebacate, 5 parts zinc oxide, 2.5 parts stearic acid, 2 parts sulfur, 1.5 parts accelerator CZ, 1.5 parts accelerator M, 60 parts carbon black N754, and 15 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 4, add octyltrimethoxysilane, stir at 60℃ for 1.5h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1g:100mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 60℃ for 6 hours, filtered, and dried to obtain composite pyrophyllite, wherein the mass-volume ratio of pyrophyllite to methanol was 1 g:20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.15; A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, and calcium stearate in the inner rubber layer component, add terpene resin, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix the natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, and calcium stearate in the outer rubber layer component. Add carbon black N550, silica, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0030] Example 4 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 5, add octyltrimethoxysilane, stir at 70℃ for 1 h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1 g: 100 mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 h, filtered, and dried to obtain composite pyrophyllite, wherein the mass-volume ratio of pyrophyllite to methanol was 1 g: 20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.2; A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0031] Example 5 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 5, add octyltrimethoxysilane, stir at 70℃ for 1 h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1 g: 100 mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 hours, filtered, and dried to obtain composite pyrophyllite. The mass-to-volume ratio of pyrophyllite to methanol was 1 g:20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane, and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.28. A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0032] Example 6 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 5, add octyltrimethoxysilane, stir at 70℃ for 1 h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1 g: 100 mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 hours, filtered, and dried to obtain composite pyrophyllite. The mass-volume ratio of pyrophyllite to methanol was 1 g: 20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane, and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.35. A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0033] Example 7 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 40.5 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 5, add octyltrimethoxysilane, stir at 70℃ for 1 h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1 g: 100 mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 h, filtered, and dried to obtain composite pyrophyllite, wherein the mass-volume ratio of pyrophyllite to methanol was 1 g: 20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.2; A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0034] Example 8 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. The nitrile rubber is composed of a first nitrile rubber and a second nitrile rubber in a mass ratio of 1:2. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 5, add octyltrimethoxysilane, stir at 70℃ for 1 h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1 g: 100 mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 h, filtered, and dried to obtain composite pyrophyllite, wherein the mass-volume ratio of pyrophyllite to methanol was 1 g: 20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.2; A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0035] Example 9 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. The nitrile rubber is composed of a first nitrile rubber and a second nitrile rubber in a mass ratio of 1:3. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 5, add octyltrimethoxysilane, stir at 70℃ for 1 h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1 g: 100 mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 h, filtered, and dried to obtain composite pyrophyllite, wherein the mass-volume ratio of pyrophyllite to methanol was 1 g: 20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.2; A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0036] Example 10 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts nitrile rubber, 3 parts silane coupling agent KH550, 6 parts zinc oxide, 3 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 10 parts dioctyl adipate, 10 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 75 parts carbon black N550, 15 parts silica, and 15 parts composite pyrophyllite. The nitrile rubber is composed of a third nitrile rubber and a second nitrile rubber in a mass ratio of 1:3, and the acrylonitrile content in the third nitrile rubber is 19%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, add acetic acid to adjust the pH to 5, add octyltrimethoxysilane, stir at 70℃ for 1 h, filter, and dry to obtain silane-modified pyrophyllite, wherein the mass-volume ratio of pyrophyllite to water is 1 g: 100 mL. A2. Silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 h, filtered, and dried to obtain composite pyrophyllite, wherein the mass-volume ratio of pyrophyllite to methanol was 1 g: 20 mL, and the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate was 1:0.1:0.2; A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0037] Comparative Example 1 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: Pyrophyllite was dispersed in water, acetic acid was added to adjust the pH to 5, octyltrimethoxysilane was added, and the mixture was stirred at 70°C for 1 hour. After filtration and drying, composite pyrophyllite was obtained, wherein the mass-volume ratio of pyrophyllite to water was 1 g: 100 mL, and the mass ratio of pyrophyllite to octyltrimethoxysilane was 1: 0.1. A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0038] Comparative Example 2 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts of nitrile rubber, 3 parts of silane coupling agent KH550, 6 parts of zinc oxide, 3 parts of stearic acid, 1 part of polyethylene wax, 1 part of calcium stearate, 10 parts of terpene resin, 10 parts of dioctyl adipate, 10 parts of dioctyl sebacate, 1.5 parts of sulfur, 2.5 parts of accelerator CZ, 2.5 parts of accelerator M, 75 parts of carbon black N550, 15 parts of silica, and 15 parts of composite pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. The preparation method of composite pyrophyllite includes the following steps: Pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice at 70℃ for 5 h, filtered, and dried to obtain composite pyrophyllite, wherein the mass-volume ratio of pyrophyllite to methanol was 1 g: 20 mL, and the mass ratio of pyrophyllite to 1-butyl-3-methylimidazolium hexafluorophosphate was 1: 0.15. A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and composite pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0039] Comparative Example 3 An oil-resistant hydraulic brake hose comprises, from the inside out, an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer; The inner rubber layer comprises the following components by weight: 80 parts nitrile rubber, 3 parts silane coupling agent KH550, 6 parts zinc oxide, 3 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 10 parts dioctyl adipate, 10 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 75 parts carbon black N550, 15 parts silica, and 15 parts pyrophyllite. Among these, the nitrile rubber is a second nitrile rubber with an acrylonitrile content of 28 wt%. The outer rubber layer comprises the following components by weight: 100 parts EPDM rubber, 4 parts silane coupling agent KH550, 7 parts zinc oxide, 2 parts stearic acid, 1 part polyethylene wax, 1 part calcium stearate, 10 parts terpene resin, 15 parts dioctyl adipate, 15 parts dioctyl sebacate, 1.5 parts sulfur, 2.5 parts accelerator CZ, 2.5 parts accelerator M, 80 parts carbon black N550, and 25 parts silica. The middle layer comprises the following components by weight: 30 parts natural rubber, 50 parts styrene-butadiene rubber, 4 parts dioctyl adipate, 4 parts dioctyl sebacate, 6 parts zinc oxide, 3 parts stearic acid, 2.5 parts sulfur, 2 parts accelerator CZ, 2 parts accelerator M, 70 parts carbon black N754, and 20 parts silica. A method for preparing an oil-resistant hydraulic brake hose includes the following steps: S1. Mix the nitrile rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the inner rubber layer component. Add terpene resin, dioctyl adipate, dioctyl sebacate, carbon black N550, silica, and pyrophyllite and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the inner rubber layer compound. S2. Mix natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add dioctyl adipate, dioctyl sebacate, carbon black N754 and silica and mix, then add sulfur, accelerator CZ and accelerator M and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent KH550, zinc oxide, stearic acid, polyethylene wax, and calcium stearate in the outer rubber layer components. Add carbon black N550, silica, dioctyl adipate, dioctyl sebacate, and terpene resin and mix. Then add sulfur, accelerator CZ, and accelerator M and continue mixing to obtain the outer rubber layer compound. S4. Extrude the inner rubber layer material to cover the mandrel to obtain the inner rubber layer. Braid the vinylon yarn to the outside of the inner rubber layer to obtain the first reinforcing layer. Extrude the middle rubber layer material to cover the outside of the first reinforcing layer to obtain the middle rubber layer. Braid the vinylon yarn to the outside of the middle rubber layer to obtain the second reinforcing layer. Extrude the outer rubber layer material to cover the outside of the second reinforcing layer, vulcanize, and remove the core to obtain the oil-resistant hydraulic brake hose.

[0040] Experimental Example 1 The oil resistance of the inner rubber layer of the oil-resistant hydraulic brake hoses prepared in Examples 1-10 and Comparative Examples 1-3 was tested. Oil resistance: The inner rubber layer of the oil-resistant hydraulic brake hoses prepared in Examples 1-10 and Comparative Examples 1-3 was measured according to the method specified in GB / T1690-2010 "Test Method for Resistance of Vulcanized Rubber or Thermoplastic Rubber to Liquids". The oil was liquid B (70% isooctane and 30% toluene), the thickness of the sample was 2 mm, the immersion temperature was 23°C, and the immersion time was 168 h. The test results are shown in Table 1. Table 1 Oil resistance test results

[0041] By comparing the data of Examples 1-3 and Comparative Examples 1-3, it was found that the mass change rate of the inner rubber layer of the oil-resistant hydraulic brake hose prepared by adding composite pyrophyllite modified with octyltrimethoxysilane and compounded with 1-butyl-3-methylimidazolium hexafluorophosphate in Examples 1-3 was smaller than that in Comparative Examples 1-3. This indicates that the oil resistance of the inner rubber layer of the oil-resistant hydraulic brake hose can be improved by adding composite pyrophyllite modified with octyltrimethoxysilane and compounded with 1-butyl-3-methylimidazolium hexafluorophosphate. By comparing the data of Examples 2 and Examples 4-6, it was found that the oil resistance of the inner rubber layer of the oil-resistant hydraulic brake hose in Examples 4-5 can be further improved by optimizing the mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate to 1:0.1:0.2-0.28.

[0042] Experimental Example 2 The elongation at break of the inner rubber layer of the oil-resistant hydraulic brake hoses prepared in Examples 4 and 7-10 was tested. Tensile strength: The elongation at break of the inner rubber layer of the oil-resistant hydraulic brake hoses prepared in Examples 4 and 7-10 was tested according to the method specified in GB / T528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber". The specimen was a type 1 dumbbell-shaped specimen and the moving speed of the testing machine was 500 mm / min. The test results are shown in Table 2. Table 2 Results of Elongation at Break Test

[0043] By comparing the data of Examples 4 and 7-10 in Tables 1 and 2, Examples 8-9 can improve the elongation at break of the inner rubber layer of the oil-resistant hydraulic brake hose while ensuring the oil resistance of the inner rubber layer.

[0044] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oil resistant hydraulic brake hose characterized by, From the inside out, it includes an inner rubber layer, a first reinforcing layer, a middle rubber layer, a second reinforcing layer, and an outer rubber layer. The inner rubber layer comprises the following components by weight: 70-80 parts of nitrile rubber, 2-3 parts of silane coupling agent, 4-6 parts of zinc oxide, 2-3 parts of stearic acid, 1-2 parts of flow aid, 5-10 parts of tackifier, 10-20 parts of plasticizer, 0.8-1.5 parts of sulfur, 3-5 parts of accelerator, 60-75 parts of carbon black, 10-15 parts of silica, and 8-15 parts of composite pyrophyllite. The composite pyrophyllite is obtained by modifying pyrophyllite with octyltrimethoxysilane and then combining it with 1-butyl-3-methylimidazolium hexafluorophosphate.

2. An oil resistant hydraulic brake hose according to claim 1, wherein The preparation method of the composite pyrophyllite includes the following steps: A1. Disperse pyrophyllite in water, adjust the pH to 4-5, add octyltrimethoxysilane, stir, filter, and dry to obtain silane-modified pyrophyllite; A2. The silane-modified pyrophyllite and 1-butyl-3-methylimidazolium hexafluorophosphate were dispersed in methanol, stirred twice, filtered, and dried to obtain composite pyrophyllite.

3. An oil resistant hydraulic brake hose according to claim 2, characterised in that, The mass ratio of pyrophyllite, octyltrimethoxysilane and 1-butyl-3-methylimidazolium hexafluorophosphate is 1:0.1:0.2~0.

28.

4. An oil resistant hydraulic brake hose according to claim 2, wherein The temperatures for the stirring and secondary stirring are each independently 60~70℃; The stirring time is 1 to 1.5 hours; the secondary stirring time is 5 to 6 hours.

5. An oil resistant hydraulic brake hose according to claim 1, wherein The nitrile rubber is composed of a first nitrile rubber and a second nitrile rubber; the first nitrile rubber and the second nitrile rubber have different acrylonitrile contents.

6. An oil resistant hydraulic brake hose according to claim 5, wherein The first nitrile rubber has an acrylonitrile content of 40.5 wt%; the second nitrile rubber has an acrylonitrile content of 28 wt%.

7. An oil resistant hydraulic brake hose according to claim 6, characterised in that The mass ratio of the first nitrile rubber to the second nitrile rubber is 1:2~3.

8. An oil resistant hydraulic brake hose according to claim 1 wherein, The middle rubber layer comprises the following components by weight: 20-30 parts natural rubber, 40-50 parts styrene-butadiene rubber, 6-8 parts plasticizer, 4-6 parts zinc oxide, 2-3 parts stearic acid, 1.5-2.5 parts sulfur, 2.4-4 parts accelerator, 50-70 parts carbon black, and 10-20 parts silica. The outer rubber layer comprises the following components in parts by weight: 100 parts EPDM rubber, 2-4 parts silane coupling agent, 5-7 parts zinc oxide, 1-2 parts stearic acid, 1-2 parts flow aid, 5-10 parts tackifier, 20-30 parts plasticizer, 0.5-1.5 parts sulfur, 3-5 parts accelerator, 60-80 parts carbon black, and 15-25 parts silica.

9. An oil resistant hydraulic brake hose according to claim 1 wherein, The first and second reinforcing layers are each independently woven from vinylon yarn.

10. A method for producing an oil-resistant hydraulic brake hose, for producing an oil-resistant hydraulic brake hose according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Mix the nitrile rubber, silane coupling agent, zinc oxide, stearic acid and flow aid in the inner rubber layer component, add carbon black, silica, composite pyrophyllite, plasticizer and tackifier and mix, then add sulfur and accelerator and continue mixing to obtain the inner rubber layer compound. S2. Mix the natural rubber, styrene-butadiene rubber, zinc oxide and stearic acid in the middle layer component, add plasticizer, carbon black and silica and mix, then add sulfur and accelerator and continue mixing to obtain the middle layer rubber compound. S3. Mix the EPDM rubber, silane coupling agent, zinc oxide, stearic acid and flow aid in the outer rubber layer components, add carbon black, silica, plasticizer and tackifier and mix, then add sulfur and accelerator and continue mixing to obtain the outer rubber layer compound. S4. The inner rubber layer material is extruded and coated onto the mandrel to obtain the inner rubber layer. Vinylon yarn is braided onto the inner rubber layer to obtain the first reinforcing layer. The middle rubber layer material is extruded and coated onto the first reinforcing layer to obtain the middle rubber layer. Vinylon yarn is braided onto the middle rubber layer to obtain the second reinforcing layer. The outer rubber layer material is extruded and coated onto the second reinforcing layer, vulcanized, and decored to obtain the oil-resistant hydraulic brake hose.

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