阅读说明：本技术 一种用于橡胶空气弹簧的磁敏橡胶组合物及其制备方法 (Magnetic-sensitive rubber composition for rubber air spring and preparation method thereof ) 是由 危银涛 王静 于 2020-06-28 设计创作，主要内容包括：本发明公开了一种用于橡胶空气弹簧的磁敏橡胶组合物及其制备方法,以重量配比计,其组分包括基体橡胶100份、活性剂2～8份、炭黑0～50份、白炭黑0～20份、硅烷偶联剂0～4份、促进剂1～3份、防老剂3～6份、硫化剂1～2份、改性铁磁性粒子200～600份、自修复剂1～10份。其中,基体橡胶由天然橡胶或氯丁橡胶或氢化丁腈橡胶组成；活性剂由纳米氧化锌和硬脂酸组成；白炭黑为高分散型沉淀法白炭黑；硅烷偶联剂为液体硅烷偶联剂Si-69；促进剂为促进剂CBS；防老剂为防老剂6PPD及防老剂RD并用；硫化剂为硫黄；自修复剂为液体丁腈橡胶-酚醛树脂。本申请的磁敏橡胶组合物拉伸强度达15MPa以上,扯断伸长率400％以上。(The invention discloses a magnetic-sensitive rubber composition for a rubber air spring and a preparation method thereof, and the magnetic-sensitive rubber composition comprises, by weight, 100 parts of matrix rubber, 2-8 parts of an active agent, 0-50 parts of carbon black, 0-20 parts of white carbon black, 0-4 parts of a silane coupling agent, 1-3 parts of a promoter, 3-6 parts of an anti-aging agent, 1-2 parts of a vulcanizing agent, 200-600 parts of modified ferromagnetic particles and 1-10 parts of a self-repairing agent. Wherein the matrix rubber is composed of natural rubber, chloroprene rubber or hydrogenated nitrile rubber; the active agent consists of nano zinc oxide and stearic acid; the white carbon black is high-dispersion type precipitation white carbon black; the silane coupling agent is a liquid silane coupling agent Si-69; the accelerator is accelerator CBS; the anti-aging agent is the combination of anti-aging agent 6PPD and anti-aging agent RD; the vulcanizing agent is sulfur; the self-repairing agent is liquid nitrile rubber-phenolic resin. The magnetic-sensitive rubber composition has the tensile strength of more than 15MPa and the elongation at break of more than 400 percent.)

1. The magnetic-sensitive rubber composition for the rubber air spring is characterized by comprising 100 parts of matrix rubber, 2-8 parts of an active agent, 0-50 parts of carbon black, 0-20 parts of white carbon black, 0-4 parts of a silane coupling agent, 1-3 parts of an accelerator, 3-6 parts of an anti-aging agent, 1-2 parts of a vulcanizing agent, 200-600 parts of modified ferromagnetic particles and 1-10 parts of a self-repairing agent in parts by weight; wherein the matrix rubber is composed of natural rubber, chloroprene rubber or hydrogenated nitrile rubber; the active agent consists of nano zinc oxide and stearic acid; the white carbon black is high-dispersion type precipitation white carbon black; the silane coupling agent is a liquid silane coupling agent Si-69; the accelerator is accelerator CBS; the anti-aging agent is an anti-aging agent 6PPD and an anti-aging agent RD which are used together; the vulcanizing agent is sulfur; the self-repairing agent is liquid nitrile rubber-phenolic resin.

2. The magnetosensitive rubber composition for the rubber air spring as claimed in claim 1, wherein the activator comprises 1-4 parts of nano zinc oxide and the balance of stearic acid.

3. The magnetosensitive rubber composition for a rubber air spring according to claim 2, wherein the nano zinc oxide includes 80% of primary particles having a particle diameter of 100nm or less and 20% of primary particles having a particle diameter of 100nm or more.

4. The magnetosensitive rubber composition for a rubber air spring according to claim 1, wherein the white carbon has a BET surface area of 120 to 200m2/g measured with nitrogen gas, a dibutyl phthalate absorption value of 2.00 to 3.50cm3/g, and a pH value of 5.0 to 8.0 when the white carbon is dispersed in water to form a 5% aqueous solution.

5. The magnetosensitive rubber composition for a rubber air spring according to claim 1, wherein the molecular weight of the liquid nitrile rubber-phenolic resin is less than 10000 g/mol.

6. The magnetosensitive rubber composition for a rubber air spring according to claim 1, wherein the liquid nitrile rubber-phenolic resin is prepared by the following method: the mol ratio of phenol to formaldehyde is 1:1.2-3.0, formaldehyde is heated and reacted for 3h at 80-95 ℃ by 36-50% of aqueous solution and 1-5% of NaOH as catalyst to obtain phenolic resin pre-polymerized liquid, then liquid nitrile rubber emulsion is added and stirred, and the liquid nitrile rubber-phenolic resin microcapsule with a core-shell structure is obtained by adjusting the pH of the solution.

7. The magnetosensitive rubber composition for a rubber air spring according to claim 1, wherein the modified ferromagnetic particles are selected from those having-OH, -COOH, -CO-groups.

8. The magnetosensitive rubber composition for a rubber air spring according to claim 7, wherein the modification method of the modified ferromagnetic particles is as follows:

weighing a certain amount of carbonyl iron powder and vinyl trimethoxy silane (the added mass fraction is 2%) according to a proportion, respectively dispersing the carbonyl iron powder and the vinyl trimethoxy silane in a mixed solution consisting of absolute ethyl alcohol and a small amount of distilled water, ultrasonically dispersing for a period of time, and mixing the two; mechanically stirring, and carrying out water bath reaction at 70-80 ℃ for a certain time; and drying at 70-80 ℃ to obtain the modified ferromagnetic particles.

9. A method for preparing a magnetosensitive rubber composition for a rubber air spring, characterized by comprising the steps of:

preparing a liquid nitrile rubber-phenolic resin bonding system (self-repairing agent) with a core-shell structure by adopting an emulsion compounding method, and characterizing the appearance and the size of the crack self-repairing agent by utilizing SEM and TEM; the mol ratio of phenol to formaldehyde is 1:1.2-3.0, formaldehyde is heated and reacted for 3h at 80-95 ℃ by 36-50% of aqueous solution and 1-5% of NaOH as catalyst to obtain phenolic resin pre-polymerized liquid, then liquid nitrile rubber emulsion is added and stirred, and liquid nitrile rubber-phenolic resin microcapsule with a core-shell structure is obtained by adjusting the PH of the solution;

adding natural rubber/chloroprene rubber/hydrogenated nitrile rubber, carbon black, white carbon black, a self-repairing agent and all compounding agents except a vulcanization system into an internal mixer, mixing for 3-4 minutes, discharging rubber at the temperature of 150-160 ℃ (the temperature of the chloroprene rubber does not exceed 120 ℃), and finishing the preparation of a section of masterbatch; placing the rubber sheet for 4 hours, adding the primary masterbatch into an internal mixer, mixing for 2-3 minutes, discharging rubber at the temperature of 140-150 ℃ (the temperature of chloroprene rubber does not exceed 120 ℃), and finishing the preparation of the secondary masterbatch; after the rubber sheet is parked for 8 hours, adding the secondary masterbatch and all compounding agents of a vulcanization system into an internal mixer, mixing for 2-3 minutes, and discharging rubber at the temperature of 95-105 ℃ to finish the preparation of final rubber; and (3) injecting the rubber compound into a mold, carrying out pre-structuring treatment under a magnetic field, and then carrying out vulcanization molding on a flat vulcanizing machine to obtain the magnetic-sensitive rubber composition.

Technical Field

The invention relates to a magnetic-sensitive rubber, which comprises a rubber composition consisting of modified carbonyl iron powder and a self-repairing agent, in particular to a magnetic-sensitive rubber composition for a rubber air spring.

The invention particularly relates to a magnetic-sensitive rubber composition mainly composed of modified carbonyl iron powder and a self-repairing agent and used for a rubber air spring and a preparation method thereof.

Background

With the continuous development and progress of scientific technology, mechanical equipment gradually turns from passive control to active control, and the magnetic-sensitive rubber is an intelligent material for active control. The magneto-sensitive rubber is a micro-nano magnetic powder reinforced rubber composite material, and the rigidity and the damping of the magneto-sensitive rubber generate millisecond-level controllable response under the action of a magnetic field, so that the bottleneck problem of magneto-rheological fluid sedimentation is overcome, and the magneto-sensitive rubber has wide application prospects in the fields of shock absorption, vibration isolation, active control and the like. For example, the 'new four-in-one' (electromotion, intellectualization, networking and sharing) of automobiles and the development of new energy automobiles (battery modules of electric automobiles can generate looseness, short circuit and disconnection under the action of road spectrums, the safety of the automobiles is affected, and electronic devices such as motors and controllers of the new energy automobiles provide more severe requirements for damping) are brand-new drives for the active damping of the magnetic sensitive rubber; however, the magnetic-sensitive rubber has the fatal problems of low tensile strength and poor fatigue resistance, and no feasible academic thought exists in the research and process control of the fatigue resistance mechanism and the fatigue resistance material.

Disclosure of Invention

The invention aims to provide a composite material with excellent mechanical property, good processing property and magnetorheological effect for an active shock absorber.

The technical solution is as follows:

the invention discloses a magnetic-sensitive rubber composition for a rubber air spring, which comprises, by weight, 100 parts of matrix rubber, 2-8 parts of an active agent, 0-50 parts of carbon black, 0-20 parts of white carbon black, 0-4 parts of a silane coupling agent, 1-3 parts of an accelerator, 3-6 parts of an anti-aging agent, 1-2 parts of a vulcanizing agent, 200-600 parts of modified ferromagnetic particles and 1-10 parts of a self-repairing agent. Wherein the matrix rubber is composed of natural rubber, chloroprene rubber or hydrogenated nitrile rubber; the active agent consists of nano zinc oxide and stearic acid; the white carbon black is high-dispersion type precipitation white carbon black; the silane coupling agent is a liquid silane coupling agent Si-69; the accelerator is accelerator CBS; the anti-aging agent is the combination of anti-aging agent 6PPD and anti-aging agent RD; the vulcanizing agent is sulfur.

Preferably, the magnetic-sensing rubber composition for the rubber air spring comprises the following components in parts by weight:

100 parts of matrix rubber, 2-8 parts of an active agent, 0-50 parts of carbon black, 0-20 parts of white carbon black, 0-4 parts of a silane coupling agent, 1-3 parts of an accelerator, 3-6 parts of an anti-aging agent, 1-2 parts of a vulcanizing agent, 200-600 parts of modified ferromagnetic particles and 1-10 parts of a self-repairing agent.

Preferably, the magnetic-sensing rubber composition for the rubber air spring comprises the following components in parts by weight:

100 parts of matrix rubber, 5 parts of active agent, 10 parts of white carbon black, 40 parts of carbon black, 2 parts of silane coupling agent, 3 parts of accelerator, 4 parts of anti-aging agent, 2 parts of vulcanizing agent, 400 parts of modified ferromagnetic particles and 6 parts of self-repairing agent.

Preferably, in the active agent, 2-4 parts of nano zinc oxide and the balance of stearic acid are used.

Preferably, the nano zinc oxide includes 80% of primary particles having a particle size of 100nm or less and 20% of primary particles having a particle size of 100nm or more.

Preferably, the white carbon black has a BET surface area measured by nitrogen gas of 120 to 200m²(ii) dibutyl phthalate absorption value of 2.00-3.50 cm³(ii)/g, and when the white carbon black is dispersed in water, 5% of water is formedThe pH value of the solution is 5.0-8.0.

Preferably, the modified ferromagnetic particles are vinyltrimethoxysilane modified carbonyl iron powder.

Preferably, the liquid nitrile rubber has a molecular weight of less than 10000 g/mol.

A preparation method of a magnetic-sensitive rubber composition for a rubber air spring comprises the following steps:

preparation of a self-repairing agent: preparing a liquid nitrile rubber-phenolic resin bonding system with a core-shell structure by adopting an emulsion compounding method, and performing appearance and size characterization on the crack self-repairing agent by utilizing SEM, TEM and the like; the molar ratio of phenol to formaldehyde is 1:1.2-3.0, formaldehyde is heated and reacted for 3 hours at 80-95 ℃ by 36-50% aqueous solution and 1-5% NaOH catalyst; obtaining phenolic resin pre-polymerized liquid, then adding liquid nitrile rubber emulsion, stirring, and adjusting the pH of the solution to obtain a liquid nitrile rubber-phenolic resin microcapsule with a core-shell structure;

adding natural rubber/chloroprene rubber/hydrogenated nitrile rubber, modified ferromagnetic particle carbon black, high-dispersion white carbon black, a self-repairing agent and all compounding agents except a vulcanization system into an internal mixer, mixing for 3-4 minutes, discharging rubber at the temperature of 150-160 ℃ (the temperature of chloroprene rubber does not exceed 120 ℃), and finishing the preparation of a first-stage masterbatch; placing the rubber sheet for 4 hours, adding the primary masterbatch into an internal mixer, mixing for 2-3 minutes, discharging rubber at the temperature of 140-150 ℃ (the temperature of chloroprene rubber does not exceed 120 ℃), and finishing the preparation of the secondary masterbatch; after the rubber sheet is parked for 8 hours, adding the secondary masterbatch and all compounding agents of a vulcanization system into an internal mixer, mixing for 2-3 minutes, and discharging rubber at the temperature of 95-105 ℃ to finish the preparation of final rubber; and (3) injecting the rubber compound into a mold, carrying out pre-structuring treatment under a magnetic field, and then carrying out vulcanization molding on a flat vulcanizing machine to obtain the magnetic-sensitive rubber composition.

The magnetic-sensitive rubber composition adopts the self-repairing agent to repair, and because of the defects or initial cracks in the rubber caused by the addition of ferromagnetic particles, the magnetic-sensitive rubber produced by the repairing agent not only can meet the use requirements of the shock absorber in use performance, but also has certain scientific research value.

The tread rubber composition of the present invention can be produced and processed by a method known to those skilled in the art, such as kneading, calendering, molding, and vulcanization. It is to be noted that after the final batch is obtained, the batch is injected into a mold and the pre-structuring is carried out under a magnetic field.

The shock absorber prepared from the magnetic-sensitive rubber composition has the tensile strength of more than 15MPa and the elongation at break of more than 400 percent.

Compared with the prior art, the invention has the advantages that:

(1) the invention adopts modified ferromagnetic particles, selects the modified ferromagnetic particles containing-OH, -COOH, -CO-and the like (as shown in figure 1), is easy to strengthen the binding force between rubber and filler, and has better dispersibility in a rubber matrix. The ferromagnetic particles can be combined with rubber, filler and the like more firmly, reduce aggregation and relieve stress concentration, thereby improving the tensile strength and fatigue life of the magnetic-sensitive rubber.

(2) According to the invention, the self-repairing agent is added into the rubber formula, the phenolic resin part in the self-repairing agent can form a chelate (shown in figure 2) with the ferromagnetic particles, the liquid nitrile rubber can be co-vulcanized with the rubber substrate, the binding force between the magnetic particles and the rubber is improved, the size of the initial crack of the rubber is controlled, and the expansion of the initial crack of the rubber is prevented, so that the tensile strength of the magnetic sensitive rubber is improved, and the service life of the magnetic sensitive rubber is prolonged. In addition, even if the core-shell structure is destroyed in the mixing process, the self-repairing agent does not affect the combination with the ferromagnetic particles and the rubber.

(3) The self-repairing agent has the advantages of simple and easily obtained raw materials and low cost.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 shows the surface of ferromagnetic particles modified with silane coupling agent (vinyltrimethoxysilane);

FIG. 2 is a structural formula of a chelate formed by phenolic resin and ferromagnetic particles.

Detailed Description

With the continuous development and progress of scientific technology, mechanical equipment gradually turns from passive control to active control, and the magnetic-sensitive rubber is an intelligent material for active control. The magneto-sensitive rubber is a micro-nano magnetic powder reinforced rubber composite material, and the rigidity and the damping of the magneto-sensitive rubber generate millisecond-level controllable response under the action of a magnetic field, so that the bottleneck problem of magneto-rheological fluid sedimentation is overcome, and the magneto-sensitive rubber has wide application prospects in the fields of shock absorption, vibration isolation, active control and the like. For example, the 'new four-in-one' (electromotion, intellectualization, networking and sharing) of automobiles and the development of new energy automobiles (battery modules of electric automobiles can generate looseness, short circuit and disconnection under the action of road spectrums, the safety of the automobiles is affected, and electronic devices such as motors and controllers of the new energy automobiles provide more severe requirements for damping) are brand-new drives for the active damping of the magnetic sensitive rubber; however, the magnetic-sensitive rubber has the fatal problems of low tensile strength and poor fatigue resistance, and no feasible academic thought exists in the research and process control of the fatigue resistance mechanism and the fatigue resistance material. The durability of the rubber damper is improved as the tensile strength is increased. Based on the above consideration, the invention creatively provides a method for improving the tensile strength of the magnetic-sensitive rubber. The tensile strength of the magnetic-sensitive rubber is improved by adding the self-repairing agent to form a stable chelate with the ferromagnetic particles. The magnetic-sensitive rubber can be used for an air spring of a motor vehicle, can improve the shock absorption performance of the motor vehicle, and improves the riding comfort and the operation stability.

Natural Rubber (NR) has good wear resistance, high elasticity, high tensile strength at break and high elongation, is one of the rubbers with the best comprehensive performance, and is widely applied. The Chloroprene Rubber (CR) has good wear resistance, direct sunlight resistance, distortion resistance, refrigerant resistance, oil resistance, good elasticity, good compression deformation and flame retardant property. The chloroprene rubber has stronger crystallization capability, is favorable for improving the fatigue resistance of materials, and is commonly used for automobile suspension. Hydrogenated Nitrile Butadiene Rubber (HNBR) is a combinationThe special rubber with excellent performance contains polar groups in the molecular structure, has high saturation of the main chain, and has good oil resistance, heat resistance, high pressure resistance, steam resistance, acid resistance, chemical solvent resistance, dynamic fatigue resistance and O resistance₃And simultaneously HNBR also has the characteristics of high strength, high tearing performance, excellent wear resistance and the like. HNBR is used as the material of products such as high-performance rubber tubes, adhesive tapes, sealing and damping parts, automobile engine system sealing parts, special wires and cables and the like. Therefore, the three rubbers are selected as the matrix material in the invention.

The tread rubber composition (magnetic sensitive rubber composition) may be mixed by a rubber mixing process, for example, mixing the rubber with various additives. The additive materials comprise: reinforcing materials such as carbon black, white carbon, vulcanization aids such as sulfur, accelerators, activators such as zinc oxide, processing aids such as tackifying resins, plasticizers, protective materials such as antioxidants, antiozonants, protective waxes, and the like.

The present invention can be more clearly understood by reference to the following examples, but the present invention is not limited to the following examples, and specific examples are as follows: