Search

CN-122011267-A - Acrylate rubber with excellent extrusion fluidity and preparation method thereof

CN122011267ACN 122011267 ACN122011267 ACN 122011267ACN-122011267-A

Abstract

The invention discloses acrylate rubber with excellent extrusion fluidity and a preparation method thereof, and belongs to the technical field of acrylate rubber production. The acrylate rubber consists of 80-100 parts by weight of (methyl) acrylate monomer, 0.01-5 parts by weight of vulcanization point monomer and 0-15 parts by weight of other modified monomers. The invention controls the weight average molecular weight to be 40-80 ten thousand by an oxidation-reduction initiation system and a specific dosage of molecular weight regulator, the molecular weight is distributed in the range of 2.0-6.0, and simultaneously adopts a physical condensation and three-stage temperature zone-separated drying process and takes the conductivity of the discharged liquid as a washing monitoring index. The invention not only realizes the high purity control of ash content less than or equal to 0.1 percent and volatile content less than or equal to 0.5 percent, but also effectively eliminates the non-covalent aggregation among macromolecules, remarkably improves the extrusion speed and the surface smoothness of rubber, solves the problems of easy material returning and orange peel, and is suitable for the fields of special extrusion products such as rubber tubes of automobile cooling systems, power steering rubber tubes, oil-resistant sealing parts and the like.

Inventors

  • YANG ZHENGUO
  • WU ZIRAN
  • DING SHAOPING

Assignees

  • 九江杜威橡胶科技有限公司

Dates

Publication Date
20260512
Application Date
20260211

Claims (8)

  1. 1. The acrylate rubber with excellent extrusion fluidity is characterized by comprising, by weight, 80-100 parts of (meth) acrylate monomers, 0.01-5 parts of vulcanization point monomers and 0-15 parts of other modified monomers, wherein the acrylate rubber is prepared by the following steps: S1, selecting monomer components, putting the monomer components into a reaction kettle containing deionized water, an anionic emulsifier accounting for 1.0-5.0% of the total mass of the monomers and a nonionic emulsifier accounting for 0.5-2.5%, emulsifying for 30-60 min at 20-45 ℃, and inducing the monomers to be fully dispersed to generate high-activity emulsion; s2, initiating polymerization at 5-50 ℃ in the presence of an oxidation-reduction initiation system and a molecular weight regulator with the total mass of 0.01-1.0 per mill, and controlling the weight average molecular weight to be in the range of 40-80 ten thousand and the weight average/number average molecular weight ratio to be in the range of 2.0-6.0 through a free radical polymerization reaction; After the reaction is finished, the temperature of the system is controlled to be kept at 60-80 ℃ for 1-4 hours for post-reaction curing, and then a terminator accounting for 0.1-1.0% of the total mass of the monomers is added for terminating the reaction to obtain a latex product; S4, adding an alkali chloride solution with the mass fraction of 5% -8% into the polymerization emulsion at 55-85 ℃ to perform physical condensation, so as to promote the broken colloidal particles to be fully separated out and generate a water-containing colloidal particle mixed solution; And (5) after vibration filtration, the S5 rubber particles enter a cleaning tank and are circularly cleaned for 30-60 minutes by hot water at 50-80 ℃ until the conductivity of the discharged liquid is 1-300 mu S/cm, so that the ash content of the product is less than or equal to 0.1% and the volatile component is less than or equal to 0.5%, and the obtained acrylate rubber is obtained.
  2. 2. The acrylic rubber excellent in extrusion flowability as claimed in claim 1, wherein the (meth) acrylic monomer in S1 is one or a combination of more of ethyl (meth) acrylate, n-butyl (meth) acrylate, methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate.
  3. 3. An acrylate rubber having excellent extrusion flowability as claimed in claim 1, wherein said vulcanization point monomer is a combination of one or more of monomers containing an active chlorine group, a carboxyl group, an epoxy group or an unsaturated double bond group.
  4. 4. The acrylate rubber with excellent extrusion fluidity according to claim 1, wherein the oxidant in the oxidation-reduction initiation system is one or more of cumene hydroperoxide, tert-butyl hydroperoxide and benzoyl peroxide, the reducing agent is one or more of sodium hydrosulfite, ferrous sulfate and sodium bisulfate, and the molar ratio of the oxidant to the reducing agent is 1.05-1.1:1.
  5. 5. The acrylic rubber having excellent extrusion flowability as claimed in claim 1, wherein the molecular weight regulator in S2 is one or a combination of a thiol regulator, a regulator butyl and an environmentally friendly odorless regulator.
  6. 6. The acrylic rubber having excellent extrusion flowability according to any one of claims 1 to 5, characterized in that the subsequent modification and molding treatment of the acrylic rubber comprises the steps of: S6, sending the acrylate rubber into an extrusion dehydrator, draining and separating under the action of a (double) screw shearing force, controlling the aperture of a die head and the rotating speed of a cutter, and ensuring the water content of the extruded colloidal particles to be 1-20%; S7, placing the dehydrated colloidal particles in a tunnel drying bin, and performing graded heat treatment by using a three-section type warm zone, wherein the temperature of the first zone is 100-120 ℃, the temperature of the second zone is 120-122 ℃ and the temperature of the third zone is 90-100 ℃, cooling in a cooling section of 40-60 ℃, and controlling the total drying time to be 30-60 minutes; s8, after the dried colloidal particles are formed by physical briquetting, putting the colloidal particles, the filler, the accelerator and the cross-linking agent into an internal mixer, and carrying out molecular mixing under a specific shear energy level field to finish the high dispersion of the auxiliary agent in the rubber base core; S9, moving the banburying sizing material to an open mill, carrying out 4-6 times of thinning operation under the conditions that the roll spacing is controlled to be 1-2 mm and the temperature is 80-100 ℃, utilizing the synergistic effect of an acoustic stress field and a mechanical shearing force to counteract non-covalent physical agglomeration, and cooling to room temperature to obtain a required product.
  7. 7. The acrylic rubber with excellent extrusion flowability according to any one of claims 1 to 5, wherein the acrylic rubber has excellent anti-reversion properties and extrusion speed, and the weight average molecular weight, weight average/number average molecular weight ratio, and z average/weight average molecular weight ratio can be calibrated in absolute value by GPC method of chromatographic grade tetrahydrofuran solvent.
  8. 8. The acrylate rubber with excellent extrusion flowability according to any one of claims 1 to 5, wherein the acrylate rubber and the vulcanized and crosslinked composition thereof are suitable for manufacturing rubber tubes of automobile cooling systems, power steering rubber tubes, oil-resistant sealing gaskets and special extrusion rubber products with high flow requirements.

Description

Acrylate rubber with excellent extrusion fluidity and preparation method thereof Technical Field The invention discloses acrylate rubber with excellent extrusion fluidity and a preparation method thereof, and belongs to the technical field of acrylate rubber production. Background With the rapid development of the global automotive industry, modern internal combustion engines and hybrid systems place near-stringent demands on the performance of the components within the engine compartment. Particularly with the popularity of turbocharging technology, the ambient temperature in the engine compartment increases significantly, and the sustained operating temperature of the core region tends to exceed 150 ℃, with transient peaks even breaking through 175 ℃. Under the high temperature condition, the traditional rubber materials such as nitrile rubber and chloroprene rubber are difficult to compete, and the problems of insufficient heat resistance stability and easy hardening and cracking seriously restrict the safety and the service life of the automobile. The automobile rubber pipe is used as a core conveying component of a cooling system, a fuel system, a power steering system and an air conditioning system, and is not only required to bear high-temperature corrosion, but also required to maintain excellent physical stability, namely oil resistance and chemical inertness when contacting various lubricating oil, fuel oil and chemical cooling liquid. In such an industrial background, the acrylate rubber is used as a saturated polymer formed by copolymerizing an acrylate main monomer and a small amount of vulcanization point monomers, the main chain does not contain double bonds, and the unique saturated structure endows the polymer with excellent heat and oxygen aging resistance, ozone resistance and excellent weather resistance and ultraviolet resistance. Meanwhile, the existence of the side chain ester group enables the polyurethane to have good mineral oil resistance and high temperature resistance and air permeability. Therefore, the acrylate rubber is an irreplaceable special rubber in the automobile industry, and is widely applied to manufacturing various sealing rings, gaskets and key automobile rubber tube products working at high temperature. The global high performance acrylate rubber market has been firmly monopolized by both European and Japanese enterprises for a long time. The ethylene acrylic rubber produced by DuPont in the United states is represented, and the ethylene structure is introduced to greatly improve the processing fluidity, cold resistance and physical property balance of the material, so that the ethylene acrylic rubber becomes the preferred scheme of the high-end rubber pipe market. Meanwhile, enterprises such as japanese rayleigh, japanese nook, da Cao and electrochemical industry have been developed in a cluster type for decades, and a deep technical barrier is constructed in this field. The national huge heads not only realize full-flow automatic control on the synthesis process, but also accumulate extremely rich experience on molecular weight design, topological structure regulation and processing aid development, and the product has excellent consistency and excellent extrusion molding performance. In contrast, the acrylate rubber industry in China is in a catch-up situation for a long time although starting earlier. Domestic products face the technical elbows of lack of variety brands, large fluctuation of quality stability, high difficulty in high molecular weight control, low automation level of production devices and the like for a long time. Until recently, with the tightening of domestic environmental protection policies and the enhancement of autonomous controllable demands of special rubber, domestic acrylate rubber has come to truly grow in explosive manner. However, in practical popularization and application, especially in the production of high-precision and long-size automobile rubber pipes, the application drop between domestic materials and imported high-end materials is still obvious. The drop is not mainly reflected on the physical properties at normal temperature, but is concentrated on the rheological property and extrusion fluidity in the processing process, which directly affects the yield and processing efficiency of downstream production enterprises. In the industrial production of rubber pipes, extrusion processing is one of the most critical process links. The ideal rubber material should have a smooth extrusion rate, a low die swell ratio and excellent surface quality. However, the conventional domestic acrylate rubber exposes a series of key technical problems in a continuous extrusion production line, namely the problems of low extrusion speed and unsmooth discharge. Domestic acrylate rubbers tend to exhibit relatively high apparent viscosities in the extruder, resulting in excessive shear stresses. When the rotating speed of the screw is increased