CN110467780B - Process for soaking and pretreating filler plasticizer and other materials before rubber mixing - Google Patents

Abstract

A process for infiltrating and pretreating materials such as a filler plasticizer and the like before rubber mixing belongs to the field of rubber. The raw materials of the invention are added into a self-made stirring kettle according to zinc oxide, stearic acid, polyethylene glycol, an anti-aging agent, carbon black N330, vinyl triacetoxy silane, carbon black N774, isopropyl triisostearoyl titanate, bis [ ditridecyl phosphite ] tetraoctyloxy titanium and paraffin oil, the self-made stirring kettle is provided with two stirring blades rotating in the same direction, the rotating speeds of the two stirring blades are different, and the self-made stirring kettle is completed by a heating, standing and soaking pretreatment process. The quality of the product obtained by mixing the raw materials treated by the pre-soaking treatment process with rubber is more stable, the hardness fluctuation range, the strength fluctuation range and the elongation fluctuation range of the rubber are greatly reduced, and the filler dispersion effect is more uniform.

Description

Process for soaking and pretreating filler plasticizer and other materials before rubber mixing

Technical Field

The invention belongs to the field of rubber, and particularly relates to a process for performing infiltration pretreatment on materials such as a filler plasticizer and the like before rubber mixing.

Background

In order to improve the service performance of rubber products, improve the process and reduce the cost, various compounding agents are required to be added into raw rubber. The process of adding various compounding ingredients to raw rubber in a rubber mixing mill to prepare a rubber compound is called mixing, and is one of the most important basic processes for rubber production.

In recent years, in order to improve the mixing efficiency, improve the quality of the mixed rubber and reduce the energy consumption, the physical and chemical characteristics, the rheological principle and the mixing equipment of the rubber in the mixing process are intensively studied to promote the continuous development of the mixing process.

The rubber mixing process is actually a rubber modification process. In the mixing process, the filler is infiltrated and dispersed by the raw rubber and the plasticizer, the adsorption and combination are generated between active points between the raw rubber and the filler, the raw rubber is swelled in the softener, and the mechanical reaction and the chemical reaction are jointly acted, so that a dispersion system tends to be stable. A series of modification processes play a decisive role in the quality of the rubber compound and the properties of the final product.

According to microscopic observation by an electron microscope, all materials in the rubber product form island-shaped dispersion in raw rubber, and all the materials are combined through active point chemical bonds to form intermolecular van der Waals force and partial electron covalent force. As with the common chemical reaction process, the process of combining active points of each material needs to be completed by means of external energy and time consumption, and the similar and compatible characteristics exist among the active points.

In the existing production process of rubber compound, raw rubber, filler and plasticizer are generally put into a rubber mixing machine together, shearing stirring or rolling is carried out through a rotor or a roller, the filler and the plasticizer are uniformly dispersed in the raw rubber after a period of time, and then the raw rubber is taken out for use, and in the process, mechanical energy is consumed in the shearing process to generate heat, so that the mixing effect is improved.

In the general mixing process, the process of combining active points of each material is completed in an internal mixer or an open mill while shearing and stirring are carried out, and the temperature control is unstable and the uniformity of the combining process cannot be maintained because the shearing force cannot be uniformly distributed in the process; meanwhile, because the formation of chemical bonds requires enough time to reach a certain amount, the mixing time is prolonged, and the excessive energy consumption is great waste in the shearing and stirring process, both labor and energy consumption.

Disclosure of Invention

Aiming at the defects, the invention provides a process for soaking and pretreating materials such as a filler plasticizer and the like before rubber mixing. The process can ensure the stability of temperature, effectively shorten the mixing time and reduce the energy consumption.

The invention solves the technical problems that the raw materials comprise: 13000-16000 parts of zinc oxide, 2500-3300 parts of stearic acid, 4300-6300 parts of polyethylene glycol, 3000-4800 parts of an anti-aging agent, 330110000-130000 parts of carbon black N, 774175175000-215000 parts of carbon black N, 175000-215000 parts of paraffin oil, 3000-4500 parts of No. 1 impregnating compound, 1150-2300 parts of No. 2 impregnating compound and 2400-3600 parts of No. 3 impregnating compound.

The raw materials are added into a self-made stirring kettle through a feeding pipe according to the sequence of zinc oxide, stearic acid, polyethylene glycol, an anti-aging agent, carbon black N330, No. 1 impregnating compound, carbon black N774, No. 2 impregnating compound, No. 3 impregnating compound and paraffin oil, the upper part of the kettle body of the self-made stirring kettle is provided with the feeding pipe and a material storage pipe, and a stirring shaft is arranged in the kettle body, the self-made stirring kettle of the invention is different from the existing stirring kettle in that the stirring shaft is two stirring shafts with the same axle center and different axle diameters, the stirring shaft is divided into an inner stirring shaft and an outer stirring shaft, the two stirring shafts are respectively controlled by different motors, the inner stirring shaft is connected with a lower stirring blade, the lower stirring blade is W-shaped, the outer stirring shaft is connected with upper stirring blades, the upper stirring blades rotate in the same direction, the stirring speed of the upper stirring blades is 156 revolutions per minute, the stirring speed of the lower stirring blades is 210 revolutions per minute, the kettle body is heated outside the stirring kettle to keep 105 +/-5 ℃, stirring is stopped after stirring for 18 minutes, standing is carried out for 27 minutes to enable the impregnating compound to fully react, the filler and the plasticizer achieve the required impregnating effect, then discharging is carried out through a discharging pipe, the impregnating pretreatment process is completed, and the next rubber compound mixing procedure can be carried out.

Further, the specific types of the above raw materials are zinc oxide (trade name of Nippon Kogyo lime company L-20), stearic acid (trade name of the product sold on the market), polyethylene glycol (trade name of Korea Leshan PEG4000), an anti-aging agent (trade name of Germany Rhine chemical 445), carbon black N330 (trade name of Germany Oliron N330), carbon black N774 (trade name of Germany Oliron N774), paraffin oil (trade name of Germany Han 1968A), a No. 1 impregnating compound (trade name of Japan shin company vinyl triacetoxysilane), a No. 2 impregnating compound (trade name of United states Kenrich company triisostearoyl titanium isopropyl titanate), and a No. 3 impregnating compound (trade name of United states Kenrich company di [ di (tridecyl) phosphite ] tetraoctyloxytitanium).

Further, wherein the filler comprises: zinc oxide, stearic acid, polyethylene glycol, an anti-aging agent, carbon black N330, carbon black N774, a No. 1 impregnating compound, a No. 2 impregnating compound and a No. 3 impregnating compound; the plasticizer is paraffin oil. In the raw materials, the total amount of the filler accounts for 55-70% of the total mass of the mixture in the pretreatment procedure, and the total amount of the plasticizer accounts for 30-45% of the total mass of the mixture in the pretreatment procedure.

Furthermore, the stirring container structure and additional devices (a stirring kettle, a double stirring paddle, a motor, a temperature control device, a timing device, a material introducing device and an automatic control device) required by the pretreatment procedure are designed according to the technical parameters (stirring mode, stirring speed, infiltration temperature, filling sequence, stirring time and standing time) required by the pretreatment procedure, and are only suitable for the process. The process does not study the influence of the volume ratio of the reaction kettle on final energy saving and mixing effect, and the volume ratio of the reaction kettle is 93-98%.

The principle is as follows: according to the invention, the filler, the plasticizer and the impregnating compound are put into a container capable of stirring at a high speed in advance, and the filler and the plasticizer are fully and uniformly contacted by stirring, so that the problem that the filler, the plasticizer and the rubber cannot be fully and uniformly mixed and contacted by only shearing and stirring by a rotor in the traditional process is solved; simultaneously, adding an impregnating compound with dual-phase interface property, forming covalent relation between a filler-phase-affinity interface of the impregnating compound and the filler, forming covalent relation between a plasticizer-phase-affinity interface of the impregnating compound and the plasticizer, and enabling the filler and the plasticizer to form a chelating structure through the bridging action of the impregnating compound so as to fully combine the filler and the plasticizer together to achieve a uniform sea-island structure. Meanwhile, a heating energy supply method is used, so that the impregnating compound which originally needs several hours to be finished can reach the required degree in the shortest time.

Has the advantages that: the quality of the product obtained by mixing the raw materials treated by the pre-soaking treatment process with rubber is more stable, the hardness fluctuation range, the strength fluctuation range and the elongation fluctuation range of the rubber are greatly reduced, and the filler dispersion effect is more uniform.

Drawings

FIG. 1 is a schematic diagram of a reaction vessel for the infiltration pretreatment process.

As shown in figure 1, a material inlet pipe, a material outlet pipe, a kettle body, an outer stirring shaft, an inner stirring shaft, an upper stirring blade and a lower stirring blade, wherein the kettle body is 3, the outer stirring shaft is 4, the inner stirring shaft is 5, the upper stirring blade is 6, and the lower stirring blade is 7.

Detailed Description

The invention is further defined by reference to the following specific examples, which are not intended to be limiting of the invention. The structure of the reaction vessel used in this example is shown in FIG. 1.

In the impregnation pretreatment step, no rubber is added, and in order to verify the effect of the impregnation pretreatment step, the physical and mechanical properties of the rubber compound after mixing need to be detected, so in the following examples, rubber material components, a crosslinking agent and a crosslinking assistant need to be added in comparison with the content of the invention.

The specific brand and model of the raw materials used in the examples were ethylene propylene diene monomer (brands of alexan-seika 4869C, alexan-seika 4450S), zinc oxide (brands of japan kojic lime L-20), stearic acid (market general brand), polyethylene glycol (brands of korea-hills PEG4000), anti-aging agent (brands of german lain chemical 445), carbon black N330 (brands of german oleuron N330), carbon black N774 (brands of german oleuron 774), paraffin oil (brands of german han san 1968A), size 1 (brands of japan shin-chen co vinyltriacetoxysilane), size 2 (brands of Kenrich co triisostearoyl titanium isopropyl), size 3 size (brands of Kenrich co di [ di (tridecyl) phosphite ] tetraoctyloxy titanium), peroxide crosslinking agent (brands of akronobjel DCP), crosslinking coagent (brands of german laic).

The production equipment and the detection equipment used in the examples were a plate vulcanizer production line (manufacturer, second rubber and plastic machinery co., ltd.) of an internal mixer open mill (dongyu oil pressure industry co., ltd.) Shao er a type rubber durometer (shanghai liu ling instrument factory), a rubber tensile tester (taiwan high-speed rail detection instrument co., ltd., china) electronic densitometer (taiwan high-speed rail detection instrument co., ltd., china) carbon black analyzer (taiwan high-speed rail detection instrument co., ltd., china)

Example 1

Without a soaking pretreatment process, 300000 g of ethylene propylene diene monomer, 15000 g of zinc oxide, 4500 g of anti-aging agent, 330120000 g of carbon black, N774195000 g of carbon black, 195000 g of paraffin oil, 6000 g of polyethylene glycol, 3000 g of stearic acid, 8400 g of cross-linking agent and 4500 g of cross-linking assistant are added into a rubber mixing mill for mixing in the following stated order; mixing results: the mixing working hour is 10050 units, and the electric energy consumption is 195 units; the hardness fluctuation range of the sizing material is 8A, the tensile strength fluctuates between 9.8 and 11.3 MPa, the elongation at break fluctuates between 221 percent and 287 percent, the specific gravity of the sizing material fluctuates between 1.155 and 1.195, and the dispersion degree of the carbon black is in the grade of 6 to 7.

Example 2

Carrying out an infiltration pretreatment process, sequentially adding 15000 g of zinc oxide, 3000 g of stearic acid, 6000 g of polyethylene glycol, 4500 g of anti-aging agent, 330120000 g of carbon black N, 4020 g of No. 1 impregnating agent, 774195000 g of carbon black N, 2180 g of No. 2 impregnating agent, 3460 g of No. 3 impregnating agent and 195000 g of paraffin oil into a self-made stirring kettle through a feed pipe 1, stirring at an upper stirring speed of 156 rpm by an upper stirring blade 6, stirring at a lower stirring speed of 210 rpm by a lower stirring blade 7, heating outside the stirring kettle to keep the kettle body at 105 ℃, stopping stirring after stirring for 18 minutes, standing for 27 minutes to fully react the impregnating agent, enabling the filler and the plasticizer to achieve the required infiltration effect, discharging materials through a discharge pipe 2, and finishing the infiltration pretreatment process.

300000 g of ethylene propylene diene monomer rubber soaking pretreatment mixture 548160 g is added into a rubber mixing mill for mixing according to the following stated sequence; mixing results: mixing working hours are 4950 units, and electric energy consumption is 84.5 units; the hardness fluctuation range of the sizing material is 3A, the tensile strength fluctuates between 13.1 and 13.7 MPa, the elongation at break fluctuates between 323 and 341 percent, the specific gravity of the sizing material fluctuates between 1.175 and 1.185, and the dispersion degree of the carbon black is in a grade of 9 to 10 (the higher the grade is, the better the dispersion effect is, and the more uniform the sizing material is).

Reason analysis: because of the soaking pretreatment process, the components such as various fillers, additives, plasticizers and the like such as carbon black are stirred by a certain reasonable method, and are fully contacted, dispersed and soaked; and the impregnating compound is heated and powered by correct temperature, the coupling effect is formed between the filler and the plasticizer, a highly-hydrophilic covalent interface is formed between the filler and the plasticizer, the impregnating pretreatment mixture is uniformly dispersed and tightly combined, and can be quickly and fully contacted with rubber in the mixing process to quickly form physical adsorption, so that the mixing progress is greatly accelerated, and the mixing working hours and the consumed energy are greatly reduced.

Meanwhile, in the infiltration pretreatment process, the surface active points of fillers such as carbon black and the like are strengthened, so that a plurality of active electrons are formed, and more chemical bonding bonds can be formed with rubber; the surface activity of fillers such as carbon black is increased, the physical adsorption quantity with rubber is also increased, more bound rubber (rubber with fillers such as carbon black as a central point and a plurality of rubber macromolecular chains coated around the fillers) is formed, and the strength and the elongation of the rubber are improved to a great extent by the two changes.

Meanwhile, after the filler and the plasticizer are subjected to the infiltration pretreatment process, all phases are dispersed very uniformly and are also dispersed uniformly in the rubber, so that the uniform rubber compound surface and the high carbon black dispersion degree are formed after the rubber is mixed; therefore, the change interval of the rubber hardness is reduced, the change value of the specific gravity is narrowed, the uniformity of rubber products is well improved, the actual use working condition is well improved, and the fatigue resistance of the rubber is improved.

Example 3

Carrying out an infiltration pretreatment process, namely adding 15000 g of zinc oxide, 3000 g of stearic acid, 6000 g of polyethylene glycol, 4500 g of anti-aging agent, 330120000 g of carbon black N, 4020 g of No. 1 impregnating compound, 774195000 g of carbon black N, 2180 g of No. 2 impregnating compound, 3460 g of No. 3 impregnating compound and 195000 g of paraffin oil into a self-made stirring kettle through a feeding pipe 1 in sequence, stirring at 235 rpm by an upper stirring blade 6 and 130 rpm by a lower stirring blade 7, heating outside the stirring kettle to keep the kettle body at 105 ℃, stopping stirring after stirring for 18 minutes, standing for 27 minutes, discharging materials through a discharging pipe 2, and finishing the infiltration pretreatment process.

300000 g of ethylene propylene diene monomer rubber soaking pretreatment mixture 548160 g is added into a rubber mixing mill for mixing according to the following stated sequence; mixing results: 7732 units of mixing man-hour and 123.9 units of electric energy consumption; the hardness fluctuation range of the rubber material is 6A, the tensile strength fluctuates between 10.7 and 12.5 MPa, the elongation at break fluctuates between 243 and 291 percent, the specific gravity of the rubber material fluctuates between 1.165 and 1.185, and the dispersion degree of the carbon black is in the grade of 7 to 8.

Reason analysis: because the upper stirring blade 6 has a fast rotating speed and the lower stirring blade 7 has a slow rotating speed, an upper material self-circulation state is formed, and the upper material slowly moves to a lower layer, so that an up-and-down convection state in the stirring kettle cannot be formed. The material dispersion was not as uniform as in example 2. Therefore, during stirring, the stirring must be carried out quickly, a certain material gap is formed, the upper material is convenient to move towards the lower part, the lower material is extruded towards the upper part at the edge of the lower stirring blade, and when the two stirring blades form rotary stirring, the upper material and the lower material are also moved and exchanged. Meanwhile, the rotation speed of the upper stirring blade and the lower stirring blade needs to meet a certain proportion, and an optimal stirring state can be formed.

Example 4

Carrying out an infiltration pretreatment process, namely adding 15000 g of zinc oxide, 3000 g of stearic acid, 6000 g of polyethylene glycol, 4500 g of anti-aging agent, 330120000 g of carbon black N, 4020 g of No. 1 impregnating compound, 774195000 g of carbon black N, 2180 g of No. 2 impregnating compound, 3460 g of No. 3 impregnating compound and 195000 g of paraffin oil into a self-made stirring kettle through a feeding pipe 1 in sequence, stirring at an upper stirring blade 6 at a stirring speed of 156 rpm and at a lower stirring blade 7 at a stirring speed of 210 rpm, heating outside the stirring kettle to keep the kettle at 75 ℃, stopping stirring after stirring for 18 minutes, standing for 27 minutes, discharging materials through a discharging pipe 2, and finishing the infiltration pretreatment process.

300000 g of ethylene propylene diene monomer rubber soaking pretreatment mixture 548160 g is added into a rubber mixing mill for mixing according to the following stated sequence; mixing results: mixing working hours are 8861 units, and electric energy consumption is 145.9 units; the hardness fluctuation range of the rubber material is 5A, the tensile strength fluctuates between 11.1 and 12.6 MPa, the elongation at break fluctuates between 234 and 283 percent, the specific gravity of the rubber material fluctuates between 1.165 and 1.185, and the degree of dispersion of the carbon black is 8 to 9.

Reason analysis: because the temperature of the heating function outside the stirring kettle is lower, the activity of the impregnating compound is insufficient, the number of the affinity interfaces formed between the fillers such as carbon black and the plasticizer is small, the surface activity of the fillers such as carbon black is insufficient, the number of chemical bonds and physical adsorption points formed between the fillers and rubber is small, and the tensile strength and the elongation at break of the rubber are not improved by the value of example 2.

Example 5

Carrying out an infiltration pretreatment process, namely adding 15000 g of zinc oxide, 3000 g of stearic acid, 6000 g of polyethylene glycol, 4500 g of anti-aging agent, 330120000 g of carbon black N, 4020 g of No. 1 impregnating compound, 774195000 g of carbon black N, 2180 g of No. 2 impregnating compound, 3460 g of No. 3 impregnating compound and 195000 g of paraffin oil into a self-made stirring kettle through a feeding pipe 1 in sequence, stirring at an upper stirring blade 6 at a stirring speed of 156 rpm and at a lower stirring blade 7 at a stirring speed of 210 rpm, heating outside the stirring kettle to keep the kettle at 105 ℃, stopping stirring after stirring for 25 minutes, discharging materials through a discharging pipe 2, and finishing the infiltration pretreatment process.

300000 g of ethylene propylene diene monomer rubber soaking pretreatment mixture 548160 g is added into a rubber mixing mill for mixing according to the following stated sequence; mixing results: the mixing working time is 5533 units, and the electric energy consumption is 97.3 units; the hardness fluctuation range of the sizing material is 4A, the tensile strength fluctuates between 11.4 and 12.5 MPa, the elongation at break fluctuates between 257 and 297 percent, the specific gravity of the sizing material fluctuates between 1.175 and 1.190, and the dispersion degree of the carbon black is in the grade of 7 to 8.

Reason analysis: although the stirring time was longer than that in example 2, the discharge was carried out without the standing process, which resulted in too short a bonding and reaction process among the materials such as filler, plasticizer and sizing agent, insufficient reaction of the sizing agent, insufficient bonding between the filler such as carbon black and plasticizer, and insufficient surface activity of the filler such as carbon black, and thus poor effect of the sizing pretreatment. Therefore, the standing and parking link is indispensable in the infiltration pretreatment process.

The foregoing examples are provided for illustration and description of the invention only and are not intended to limit the invention to the scope of the described examples. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed.

Claims (1)

1. A process for pre-treating materials before rubber mixing by infiltration is characterized in that raw materials in parts by weight are added into a self-made reaction kettle through a feeding pipe (1) according to the sequence of filling materials and plasticizers, wherein the filling materials comprise: 13000-16000 parts of zinc oxide, 2500-3300 parts of stearic acid, 4300-6300 parts of polyethylene glycol, 3000-4800 parts of an anti-aging agent, 330110000-130000 parts of carbon black, 3000-4500 parts of vinyltriacetoxysilane, 774175000-215000 parts of carbon black, 1150-2300 parts of triisostearoyltitanium isopropyl ester, 2400-3600 parts of bis [ ditridecyl phosphite ] tetraoctyloxytitanium, and sequentially adding the components into a self-made reaction kettle through a feeding pipe (1) according to the sequence; adding 175000-215000 parts of paraffin oil serving as a plasticizer into a self-made stirring kettle, stirring and heating at 100-110 ℃, standing for 27 minutes, discharging through a discharge pipe (2), and finishing the soaking pretreatment process; wherein the total amount of the filler accounts for 55-70% of the total mass of the raw materials, and the total amount of the plasticizer accounts for 30-45% of the total mass of the raw materials; the stirring shaft is two (mixing) shafts with different axle diameters of axle center in the self-control stirred tank, and this (mixing) shaft divide into interior (mixing) shaft (5) and outer (mixing) shaft (4), and two (mixing) shafts are controlled respectively through the motor of difference, and stirring leaf (7) are down connected to interior (mixing) shaft (5), and stirring leaf (6) are connected to outer (mixing) shaft (4), and stirring leaf corotation about stirring leaf goes up stirring leaf (6) stirring speed 156 revolutions per minute, and stirring leaf (7) stirring speed 210 revolutions per minute down, and the churning time is 18 minutes.

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