A method for preparing chlorosulfonated polyethylene with high efficiency

Abstract

The invention discloses a high-efficiency preparation method of chlorosulfonated polyethylene, belonging to the technical field of chlorosulfonated polyethylene preparation. The preparation method comprises the following steps: grinding, mixing, compounding and reacting; in the grinding, chlorinated polyethylene is ground separately to obtain large chlorinated polyethylene particles and small chlorinated polyethylene particles; in the compounding, white carbon black and a sodium dodecylbenzene sulfonate aqueous solution are mixed, stirred at room temperature, filtered, dried, mixed with sulfonyl chloride, stirred at room temperature to obtain composite white carbon black; the preparation method of the invention has the advantages of fast reaction speed, low equipment investment, short vulcanization time of the prepared chlorosulfonated polyethylene, good physical and mechanical properties and high temperature resistance, and low amount of isolation agent.

Description

Technical Field

[0001] The invention relates to the technical field of chlorosulfonated polyethylene preparation, and in particular to a method for preparing chlorosulfonated polyethylene with high efficiency. Background Art

[0002] Chlorosulfonated polyethylene is an elastomer made from low-density polyethylene or high-density polyethylene through chlorination and chlorosulfonation reactions. It is white or yellow and can be dissolved in aromatic hydrocarbon solvents and chlorinated hydrocarbon solvents, but not in aliphatic hydrocarbon solvents and alcohol solvents. It can only swell but not dissolve in ketone solvents and ether solvents. Chlorosulfonated polyethylene has excellent ozone resistance, aging resistance and chemical corrosion resistance, as well as excellent physical and mechanical properties, insulation properties, high temperature resistance, low temperature resistance, oil resistance, flame resistance and wear resistance. Chlorosulfonated polyethylene is widely used in wires and cables, waterproof membranes and the automotive industry.

[0003] The existing preparation methods of chlorosulfonated polyethylene include solvent method and gas-solid method. The solvent method is a traditional preparation method of chlorosulfonated polyethylene, specifically, polyethylene is dissolved in an organic solvent by heating and pressurizing to obtain an organic solution of polyethylene, and then chlorine and sulfur dioxide are introduced into the organic solution of polyethylene, and the reaction is carried out under the action of ultraviolet rays or initiators to obtain chlorosulfonated polyethylene. Among them, the commonly used organic solvent is carbon tetrachloride, but the solvent method has the problems of large consumption of organic solvent and low utilization rate of sulfur dioxide, and not only a large amount of acidic gas is generated in the reaction, but the prepared chlorosulfonated polyethylene is also easy to condense, resulting in the problem of complex post-processing in the solvent method. The gas-solid method is to introduce chlorine and sulfur dioxide into polyethylene or chlorinated polyethylene, and react under the action of ultraviolet rays or initiators. Compared with the solvent method, the gas-solid method has the advantages of less pollution, low cost and simple post-processing.

[0004] However, when chlorosulfonated polyethylene is prepared by the gas-solid method, the following problems exist: First, when chlorosulfonated polyethylene is produced by the gas-solid method, polyethylene or chlorinated polyethylene is first ground to obtain polyethylene powder or chlorinated polyethylene powder, and then the polyethylene powder or chlorinated polyethylene powder is reacted with chlorine and sulfur dioxide. The particle size and specific surface area of ​​the polyethylene powder or chlorinated polyethylene powder are greatly affected, and the problem of uneven reaction is prone to occur, resulting in a large amount of residual crystals in the chlorosulfonated polyethylene prepared by the gas-solid method, and poor distribution of chlorine groups and sulfonyl groups in the molecular chain of the chlorosulfonated polyethylene, which further leads to a long vulcanization time of the prepared chlorosulfonated polyethylene, and reduced physical and mechanical properties and high temperature resistance; Second, when chlorosulfonated polyethylene is produced by the gas-solid method, there is a problem of slow reaction heat transfer, which leads to uneven reaction, which further leads to poor distribution of chlorine groups and sulfonyl groups in the molecular chain of the prepared chlorosulfonated polyethylene, and also leads to a reduced reaction rate.

[0005] For the first and second problems mentioned above, existing solutions include extending the grinding time when grinding polyethylene or chlorinated polyethylene to reduce the particle size of polyethylene powder or chlorinated polyethylene powder, increasing the reaction temperature to the melting temperature of polyethylene powder or chlorinated polyethylene powder, and adding an isolating agent to avoid the problem of uneven reaction due to adhesion during the reaction; for the second problem mentioned above, existing solutions include using a fluidized bed reactor or using ultraviolet light and an initiator to initiate the reaction, wherein the use of a fluidized bed reactor can speed up the reaction heat transfer to avoid the problem of uneven reaction; the use of ultraviolet light and an initiator to initiate the reaction can increase the generation of free radicals to increase the reaction rate.

[0006] However, when conducting experiments based on the above-mentioned solution, the following problems were found: First, the added isolation agent is mainly silicon dioxide, which can be adsorbed on the surface of polyethylene powder or chlorinated polyethylene powder, thereby achieving the effect of preventing adhesion. As the particle size of polyethylene powder or chlorinated polyethylene powder decreases, the specific surface area increases, resulting in an increase in the amount of silicon dioxide used; Second, the use of a fluidized bed reactor will lead to an increase in equipment investment, and silicon dioxide will reflect ultraviolet light, resulting in a decrease in the initiation effect of ultraviolet light, which further leads to a lack of obvious effect on improving the reaction rate when ultraviolet light and initiator are used together for initiation. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides a high-efficiency method for preparing chlorosulfonated polyethylene, which has fast reaction speed, low equipment investment, short vulcanization time of the prepared chlorosulfonated polyethylene, good physical and mechanical properties and high temperature resistance, and low amount of isolation agent.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] A high-efficiency preparation method of chlorosulfonated polyethylene, comprising the following steps: grinding, mixing, compounding, and reacting;

[0010] The grinding comprises grinding the chlorinated polyethylene separately to obtain large chlorinated polyethylene particles and small chlorinated polyethylene particles;

[0011] The chlorine content of the chlorinated polyethylene is 25wt%, the Mooney viscosity ML (1+4) at 100°C is 50, and the volatile matter content is 0.1wt%;

[0012] The particle size of the large chlorinated polyethylene particles is 100-120 mesh;

[0013] The particle size of the small chlorinated polyethylene particles is 325 mesh;

[0014] The mixing is performed by adding small chlorinated polyethylene particles and a hexadecyltrimethylammonium chloride aqueous solution into a reactor, adjusting the stirring speed of the reactor to 30-60 rpm, stirring at room temperature for 2-2.5 hours, filtering, and drying at 80-90° C. to obtain surface-treated small chlorinated polyethylene particles; adding white carbon black and a sodium dodecylbenzene sulfonate aqueous solution into a reactor, adjusting the stirring speed of the reactor to 30-60 rpm, stirring at room temperature for 2-2.5 hours, filtering, and drying at 80-90° C. to obtain surface-treated white carbon black; adding surface-treated small chlorinated polyethylene particles and water into a reactor, adjusting the stirring speed of the reactor to 100-150 rpm, stirring at room temperature for 30-40 minutes, adding the surface-treated white carbon black into the reactor, continuing to stir for 1-1.5 hours after the addition is completed, filtering, and drying at 80-90° C. to obtain mixed small chlorinated polyethylene particles;

[0015] In the mixing, the dosage ratio of small chlorinated polyethylene particles, hexadecyltrimethylammonium chloride aqueous solution, white carbon black, sodium dodecylbenzenesulfonate aqueous solution and water is 1-1.1kg:10-12L:0.024-0.026kg:0.9-1L:10-12L;

[0016] The concentration of the hexadecyltrimethylammonium chloride aqueous solution is 1wt%;

[0017] The white carbon black is fumed white carbon black with a particle size of 20 nm;

[0018] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0019] The addition rate of the surface treated white carbon black is 0.04-0.05 kg / min;

[0020] The composite comprises adding white carbon black and sodium dodecylbenzene sulfonate aqueous solution into a reaction kettle, adjusting the stirring speed of the reaction kettle to 30-60 rpm, stirring at room temperature for 2-2.5 hours, filtering, drying at 100-105° C., adding sulfonyl chloride into a reaction kettle, adjusting the stirring speed of the reaction kettle to 30-60 rpm, stirring at room temperature for 30-40 minutes, and obtaining composite white carbon black;

[0021] In the compounding, the amount ratio of white carbon black, sodium dodecylbenzenesulfonate aqueous solution and sulfonyl chloride is 0.014-0.015kg:0.5-0.6L:0.01-0.012kg;

[0022] The white carbon black is precipitated white carbon black with a particle size of 2 μm;

[0023] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0024] The reaction comprises adding large chlorinated polyethylene particles, mixed small chlorinated polyethylene particles, composite white carbon black and azobisisobutyronitrile into a reactor, fixing an ultraviolet lamp on the reactor cover, sealing the reactor, replacing the air in the reactor with nitrogen, turning on the ultraviolet lamp, raising the temperature in the reactor to 40-45° C., adjusting the stirring speed to 100-200 rpm, stirring for 10-11 minutes, introducing a mixed gas of chlorine and sulfur dioxide into the reactor until the pressure in the reactor is 0.06-0.07 MPa, stirring for 10-11 minutes, cooling the reactor, exhausting the gas to normal temperature and pressure, and continuing to introduce a mixed gas of chlorine and sulfur dioxide into the reactor. The pressure in the reactor is 0.06-0.07MPa, and the mixture is stirred for 10-11min. The reactor is cooled and vented to room temperature and pressure, and a mixed gas of chlorine and sulfur dioxide is continuously introduced into the reactor until the pressure in the reactor is 0.06-0.07MPa, and the mixture is stirred for 10-11min. The reactor is cooled and vented to room temperature and pressure, and nitrogen is introduced to purify the air in the reactor, and active magnesium oxide is added into the reactor, and the mixture is stirred for 15-20min. The materials in the reactor are washed with water, and then filtered, and the filtrate and the filter residue are respectively taken, and the magnesium chloride in the filtrate is recovered, and the filter residue is dried at 80-90°C and crushed to obtain chlorosulfonated polyethylene;

[0025] The dosage ratio of the small chlorinated polyethylene particles in the mixture, the white carbon black in the composite, the large chlorinated polyethylene particles in the reaction, azobisisobutyronitrile, and active magnesium oxide is 1-1.1kg: 0.014-0.015kg: 2-2.3kg: 0.008-0.009kg: 0.024-0.026kg;

[0026] In the reaction, the power of the ultraviolet lamp is 1 kW and the wavelength is 380 nm;

[0027] The volume ratio of chlorine to sulfur dioxide in the mixed gas of chlorine and sulfur dioxide is 1-1.2:1;

[0028] The particle size of the active magnesium oxide is 1 μm.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The method for preparing chlorosulfonated polyethylene with high efficiency of the present invention comprises four steps of grinding, mixing, compounding and reacting. The grinding step is to grind chlorinated polyethylene to obtain chlorinated polyethylene particles with different particle sizes, namely large chlorinated polyethylene particles and small chlorinated polyethylene particles. The mixing step is to use a hexadecyltrimethylammonium chloride aqueous solution to surface treat the small chlorinated polyethylene particles, and adsorb hexadecyltrimethylammonium chloride with positive charge on the surface of the small chlorinated polyethylene particles. The surface of fumed silica is treated with a sodium dodecylbenzene sulfonate aqueous solution, and sodium dodecylbenzene sulfonate with negative charge is adsorbed on the surface of the fumed silica. The chlorinated polyethylene particles are mixed with fumed silica to obtain small chlorinated polyethylene particles with a fumed silica layer on the surface, namely, mixed small chlorinated polyethylene particles; the compounding is to use a sodium dodecylbenzene sulfonate aqueous solution to treat the surface of precipitated silica, adsorb negatively charged sodium dodecylbenzene sulfonate on the surface of the precipitated silica, and then mix it with sulfonyl chloride, fix and disperse the sulfonyl chloride through the adsorption of the precipitated silica, and obtain precipitated silica with sulfonyl chloride fixed, namely, composite silica; the reaction is to mix large chlorinated polyethylene particles, mixed small chlorinated polyethylene particles, composite silica, and azobisisobutyronitrile, and then mix the small chlorinated polyethylene particles and the composite silica. The negative charge on the surface of composite silica promotes dispersion, thereby ensuring that the large chlorinated polyethylene particles and the mixed small chlorinated polyethylene particles can be quickly and evenly dispersed. The fumed silica on the surface of the mixed small chlorinated polyethylene particles acts as an isolating agent, avoiding adhesion between the large chlorinated polyethylene particles and the small chlorinated particles in the mixed small chlorinated polyethylene particles, thereby avoiding the uneven dispersion phenomenon when the chlorinated polyethylene particles are mixed with the isolating agent. The composite silica can further isolate and prevent adhesion. Under the protection of nitrogen and stirring under ultraviolet light, the sulfonyl chloride on the surface of the composite silica forms free radicals, which react with the unbound gas on the surface. The large chlorinated particles of gas phase silica react to form a layer of chlorosulfonated polyethylene shell, which further avoids the bonding problem. Then, chlorine and sulfur dioxide are introduced, and the gas phase silica on the surface of the mixed small chlorinated polyethylene particles can reflect ultraviolet light and reflect the ultraviolet light to the surface of the large chlorinated polyethylene particles, thereby increasing the reaction speed of the large chlorinated polyethylene particles. As the reaction proceeds, the small chlorinated particles are gradually chlorosulfonated, thereby ensuring the reaction speed, reducing equipment investment and the amount of isolation agent used, and reducing the residual crystallization amount of chlorosulfonated polyethylene, avoiding the problem of poor random distribution of chlorine groups and sulfonyl groups in the chlorosulfonated polyethylene molecular chain;

[0031] (2) The high-efficiency method for preparing chlorosulfonated polyethylene of the present invention has a fast reaction speed. When the reaction temperature is 40-45°C and the total reaction time is 40-44 minutes, the chlorine content of the prepared chlorosulfonated polyethylene is 35.2-36.0% and the sulfur content is 1.24-1.31%;

[0032] (3) The highly efficient method for preparing chlorosulfonated polyethylene of the present invention can accelerate the reaction heat transfer without using a fluidized bed reactor to avoid the problem of uneven reaction;

[0033] (4) The high-efficiency preparation method of chlorosulfonated polyethylene of the present invention has a short vulcanization time of the prepared chlorosulfonated polyethylene, and the positive vulcanization time t90 is 457-476s;

[0034] (5) The high-efficiency preparation method of chlorosulfonated polyethylene of the present invention has good physical and mechanical properties. The chlorosulfonated polyethylene after vulcanization has a tensile strength of 35.2-37.1 MPa, an elongation at break of 634-658%, and a tear strength of 63-65 kgf / cm;

[0035] (6) The high-efficiency preparation method of chlorosulfonated polyethylene of the present invention has good high temperature resistance. After the vulcanized chlorosulfonated polyethylene is heat aged in hot air at 110°C for 240 hours, the change rate of tensile strength is -2.5% to -1.7%, and the change rate of elongation at break is -3.4% to -2.9%;

[0036] (7) The method for preparing chlorosulfonated polyethylene with high efficiency of the present invention requires a small amount of release agent used in the preparation. DETAILED DESCRIPTION

[0037] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described.

[0038] Example 1

[0039] A method for preparing chlorosulfonated polyethylene with high efficiency, specifically comprising:

[0040] 1. Grinding: Grinding the chlorinated polyethylene to particle sizes of 100 mesh and 325 mesh respectively to obtain large chlorinated polyethylene particles and small chlorinated polyethylene particles;

[0041] The chlorine content of the chlorinated polyethylene is 25wt%, the Mooney viscosity ML (1+4) at 100°C is 50, and the volatile matter content is 0.1wt%;

[0042] 2. Mixing: Add 1kg of small chlorinated polyethylene particles and 10L of hexadecyltrimethylammonium chloride aqueous solution into a reactor, adjust the stirring speed of the reactor to 30rpm, stir at room temperature for 2h, filter, and dry at 80°C to obtain surface-treated small chlorinated polyethylene particles; add 0.024kg of white carbon black and 0.9L of sodium dodecylbenzene sulfonate aqueous solution into a reactor, adjust the stirring speed of the reactor to 30rpm, stir at room temperature for 2h, filter, and dry at 80°C to obtain surface-treated white carbon black; add the surface-treated small chlorinated polyethylene particles and 10L of water into a reactor, adjust the stirring speed of the reactor to 100rpm, stir at room temperature for 30min, slowly add the surface-treated white carbon black into the reactor, control the addition rate to 0.04kg / min, continue stirring for 1h after the addition, filter, and dry at 80°C to obtain mixed small chlorinated polyethylene particles;

[0043] The concentration of the hexadecyltrimethylammonium chloride aqueous solution is 1wt%;

[0044] The white carbon black is fumed white carbon black with a particle size of 20 nm;

[0045] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0046] 3. Compounding: Add 0.014 kg of white carbon black and 0.5 L of sodium dodecylbenzene sulfonate aqueous solution into a reactor, adjust the stirring speed of the reactor to 30 rpm, stir at room temperature for 2 h, filter, dry at 100 ° C, add 0.01 kg of sulfonyl chloride into the reactor, adjust the stirring speed of the reactor to 30 rpm, stir at room temperature for 30 min, and obtain composite white carbon black;

[0047] The white carbon black is precipitated white carbon black with a particle size of 2 μm;

[0048] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0049] 4. Reaction: 2g of large chlorinated polyethylene particles, the mixed small chlorinated polyethylene particles obtained in the second mixing step, the composite white carbon black obtained in the third compounding step, and 0.008kg of azobisisobutyronitrile are added to a reactor. A UV lamp is fixed on the lid of the reactor. After the reactor is sealed, nitrogen is used to replace the air in the reactor. Then the UV lamp is turned on, the temperature in the reactor is raised to 40°C, the stirring speed is adjusted to 100rpm, and stirred for 10min. A mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor is 0.06MPa, and stirred for 10min. The reactor is cooled and vented to room temperature and pressure, and the reactor is continued to be passed. A mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor reaches 0.06 MPa, and the mixture is stirred for 10 minutes. The reactor is cooled and vented to room temperature and pressure. The mixed gas of chlorine and sulfur dioxide is continued to be introduced into the reactor until the pressure in the reactor reaches 0.06 MPa, and the mixture is stirred for 10 minutes. The reactor is cooled and vented to room temperature and pressure. Nitrogen is introduced to purify the air in the reactor. 0.024 kg of active magnesium oxide is added into the reactor, and the mixture is stirred for 15 minutes. The materials in the reactor are washed with water, and then filtered. The filtrate and the filter residue are respectively taken, and the magnesium chloride in the filtrate is recovered. The filter residue is dried at 80° C. and crushed to obtain chlorosulfonated polyethylene.

[0050] The power of the ultraviolet lamp is 1 kW and the wavelength is 380 nm;

[0051] The volume ratio of chlorine to sulfur dioxide in the mixed gas of chlorine and sulfur dioxide is 1:1;

[0052] The particle size of the active magnesium oxide is 1 μm.

[0053] Example 2

[0054] A method for preparing chlorosulfonated polyethylene with high efficiency, specifically comprising:

[0055] 1. Grinding: Grinding the chlorinated polyethylene to particle sizes of 100 mesh and 325 mesh respectively to obtain large chlorinated polyethylene particles and small chlorinated polyethylene particles;

[0056] The chlorine content of the chlorinated polyethylene is 25wt%, the Mooney viscosity ML (1+4) at 100°C is 50, and the volatile matter content is 0.1wt%;

[0057] 2. Mixing: Add 1.05kg of small chlorinated polyethylene particles and 11L of hexadecyltrimethylammonium chloride aqueous solution into a reactor, adjust the stirring speed of the reactor to 40rpm, stir at room temperature for 2.5h, filter, and dry at 85°C to obtain surface-treated small chlorinated polyethylene particles; add 0.025kg of white carbon black and 0.95L of sodium dodecylbenzene sulfonate aqueous solution into a reactor, adjust the stirring speed of the reactor to 40rpm, stir at room temperature for 2.5h, filter, and dry at 85°C to obtain surface-treated white carbon black; add the surface-treated small chlorinated polyethylene particles and 11L of water into a reactor, adjust the stirring speed of the reactor to 120rpm, stir at room temperature for 35min, slowly add the surface-treated white carbon black into the reactor, control the addition speed to 0.04kg / min, continue stirring for 1.5h after the addition, filter, and dry at 85°C to obtain mixed small chlorinated polyethylene particles;

[0058] The concentration of the hexadecyltrimethylammonium chloride aqueous solution is 1wt%;

[0059] The white carbon black is fumed white carbon black with a particle size of 20 nm;

[0060] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0061] 3. Compounding: 0.014 kg of white carbon black and 0.55 L of sodium dodecylbenzene sulfonate aqueous solution were added to a reactor, the stirring speed of the reactor was adjusted to 40 rpm, stirred at room temperature for 2.5 h, filtered, dried at 105 ° C, and then added to the reactor with 0.011 kg of sulfonyl chloride, the stirring speed of the reactor was adjusted to 40 rpm, and stirred at room temperature for 35 min to obtain composite white carbon black;

[0062] The white carbon black is precipitated white carbon black with a particle size of 2 μm;

[0063] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0064] 4. Reaction: 2.1 kg of large chlorinated polyethylene particles, the mixed small chlorinated polyethylene particles obtained in the second mixing step, the composite white carbon black obtained in the third compounding step, and 0.009 kg of azobisisobutyronitrile are added to the reactor. A UV lamp is fixed on the lid of the reactor. After the reactor is sealed, nitrogen is used to replace the air in the reactor. Then the UV lamp is turned on, the temperature in the reactor is raised to 42°C, the stirring speed is adjusted to 150 rpm, and stirred for 11 minutes. A mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor is 0.07 MPa, and stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure, and the reactor is continued to be heated to 42°C. A mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor reaches 0.07 MPa, and the mixture is stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure. A mixed gas of chlorine and sulfur dioxide is continued to be introduced into the reactor until the pressure in the reactor reaches 0.07 MPa, and the mixture is stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure. Nitrogen is introduced to purify the air in the reactor. 0.025 kg of active magnesium oxide is added into the reactor, and the mixture is stirred for 18 minutes. The materials in the reactor are washed with water, and then filtered. The filtrate and the filter residue are respectively taken, and the magnesium chloride in the filtrate is recovered. The filter residue is dried at 85° C. and crushed to obtain chlorosulfonated polyethylene.

[0065] The power of the ultraviolet lamp is 1 kW and the wavelength is 380 nm;

[0066] The volume ratio of chlorine to sulfur dioxide in the mixed gas of chlorine and sulfur dioxide is 1.1:1;

[0067] The particle size of the active magnesium oxide is 1 μm.

[0068] Example 3

[0069] A method for preparing chlorosulfonated polyethylene with high efficiency, specifically comprising:

[0070] 1. Grinding: Grinding the chlorinated polyethylene to particle sizes of 120 mesh and 325 mesh respectively to obtain large chlorinated polyethylene particles and small chlorinated polyethylene particles;

[0071] The chlorine content of the chlorinated polyethylene is 25wt%, the Mooney viscosity ML (1+4) at 100°C is 50, and the volatile matter content is 0.1wt%;

[0072] 2. Mixing: Add 1.1 kg of small chlorinated polyethylene particles and 12 L of hexadecyltrimethylammonium chloride aqueous solution into a reactor, adjust the stirring speed of the reactor to 60 rpm, stir at room temperature for 2.5 h, filter, and dry at 90 ° C to obtain surface-treated small chlorinated polyethylene particles; add 0.026 kg of white carbon black and 1 L of sodium dodecylbenzene sulfonate aqueous solution into a reactor, adjust the stirring speed of the reactor to 60 rpm, stir at room temperature for 2.5 h, filter, and dry at 90 ° C to obtain surface-treated white carbon black; add the surface-treated small chlorinated polyethylene particles and 12 L of water into a reactor, adjust the stirring speed of the reactor to 150 rpm, stir at room temperature for 40 min, slowly add the surface-treated white carbon black into the reactor, control the addition rate to 0.05 kg / min, continue stirring for 1.5 h after the addition, filter, and dry at 90 ° C to obtain mixed small chlorinated polyethylene particles;

[0073] The concentration of the hexadecyltrimethylammonium chloride aqueous solution is 1wt%;

[0074] The white carbon black is fumed white carbon black with a particle size of 20 nm;

[0075] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0076] 3. Compounding: 0.015 kg of white carbon black and 0.6 L of sodium dodecylbenzene sulfonate aqueous solution were added to a reactor, the stirring speed of the reactor was adjusted to 60 rpm, stirred at room temperature for 2.5 h, filtered, dried at 105 ° C, and then added to the reactor with 0.012 kg of sulfonyl chloride, the stirring speed of the reactor was adjusted to 60 rpm, and stirred at room temperature for 40 min to obtain composite white carbon black;

[0077] The white carbon black is precipitated white carbon black with a particle size of 2 μm;

[0078] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0079] 4. Reaction: 2.3 kg of large chlorinated polyethylene particles, the mixed small chlorinated polyethylene particles obtained in the second mixing step, the composite white carbon black obtained in the third compounding step, and 0.009 kg of azobisisobutyronitrile are added to the reactor. A UV lamp is fixed on the lid of the reactor. After the reactor is sealed, nitrogen is used to replace the air in the reactor. Then the UV lamp is turned on, the temperature in the reactor is raised to 45 ° C, the stirring speed is adjusted to 200 rpm, and stirred for 11 minutes. A mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor is 0.07 MPa, and stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure, and the reactor is continued to be heated to 45 ° C. A mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor is 0.07 MPa, and the mixture is stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure. A mixed gas of chlorine and sulfur dioxide is continued to be introduced into the reactor until the pressure in the reactor is 0.07 MPa, and the mixture is stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure. Nitrogen is introduced to purify the air in the reactor. 0.026 kg of active magnesium oxide is added into the reactor, and the mixture is stirred for 20 minutes. The materials in the reactor are washed with water, and then filtered. The filtrate and the filter residue are respectively taken, and the magnesium chloride in the filtrate is recovered. The filter residue is dried at 90° C. and crushed to obtain chlorosulfonated polyethylene.

[0080] The power of the ultraviolet lamp is 1 kW and the wavelength is 380 nm;

[0081] The volume ratio of chlorine to sulfur dioxide in the mixed gas of chlorine and sulfur dioxide is 1.2:1;

[0082] The particle size of the active magnesium oxide is 1 μm.

[0083] Comparative Example 1

[0084] A method for preparing chlorosulfonated polyethylene with high efficiency, specifically comprising:

[0085] 1. Grinding: Grind the chlorinated polyethylene to a particle size of 325 meshes to obtain chlorinated polyethylene particles;

[0086] The chlorine content of the chlorinated polyethylene is 25wt%, the Mooney viscosity ML (1+4) at 100°C is 50, and the volatile matter content is 0.1wt%;

[0087] 2. Mixing: Add 3.15kg of chlorinated polyethylene particles and 33L of hexadecyltrimethylammonium chloride into a reactor, adjust the stirring speed of the reactor to 40rpm, stir at room temperature for 2.5h, filter, and dry at 85°C to obtain surface-treated chlorinated polyethylene particles; add 0.075kg of white carbon black and 2.85L of sodium dodecylbenzene sulfonate aqueous solution into a reactor, adjust the stirring speed of the reactor to 40rpm, stir at room temperature for 2.5h, filter, and dry at 85°C to obtain surface-treated white carbon black; add the above-mentioned surface-treated chlorinated polyethylene particles and 33L of water into a reactor, adjust the stirring speed of the reactor to 120rpm, stir at room temperature for 35min, slowly add the above-mentioned surface-treated white carbon black into the reactor, control the addition rate to 0.04kg / min, continue stirring for 1.5h after the addition is completed, filter, and dry at 85°C to obtain mixed chlorinated polyethylene particles;

[0088] The concentration of the hexadecyltrimethylammonium chloride aqueous solution is 1wt%;

[0089] The white carbon black is fumed white carbon black with a particle size of 20 nm;

[0090] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0091] 3. Reaction: Add the mixed chlorinated polyethylene particles obtained in the mixing step of step 2, 0.011 kg of sulfonyl chloride, and 0.009 kg of azobisisobutyronitrile into a reactor. A UV lamp is fixed on the lid of the reactor. After the reactor is sealed, nitrogen is used to replace the air in the reactor. Then, the UV lamp is turned on. The temperature in the reactor is raised to 42°C, the stirring speed is adjusted to 150 rpm, and stirred for 11 minutes. A mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor is 0.07 MPa. Stir for 11 minutes, cool the reactor, exhaust it to room temperature and pressure, and continue to introduce chlorine and sulfur dioxide into the reactor. The mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor is 0.07 MPa, and the mixture is stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure. The mixed gas of chlorine and sulfur dioxide is continued to be introduced into the reactor until the pressure in the reactor is 0.07 MPa, and the mixture is stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure. Nitrogen is introduced to purify the air in the reactor. 0.025 kg of active magnesium oxide is added into the reactor, and the mixture is stirred for 18 minutes. The materials in the reactor are washed with water, filtered, and the filtrate and filter residue are respectively taken. The magnesium chloride in the filtrate is recovered, and the filter residue is dried at 85°C and crushed to obtain chlorosulfonated polyethylene.

[0092] The power of the ultraviolet lamp is 1 kW and the wavelength is 380 nm;

[0093] The volume ratio of chlorine to sulfur dioxide in the mixed gas of chlorine and sulfur dioxide is 1.1:1;

[0094] The particle size of the active magnesium oxide is 1 μm.

[0095] That is, this comparative example is based on the high-efficiency preparation method of chlorosulfonated polyethylene in Example 2, omitting the use of large chlorinated polyethylene particles, and directly adding the sulfonyl chloride in the third step of the compounding step in Example 2 to the fourth step of the reaction step.

[0096] Comparative Example 2

[0097] A method for preparing chlorosulfonated polyethylene with high efficiency, specifically comprising:

[0098] 1. Grinding: Grind the chlorinated polyethylene to a particle size of 100 mesh to obtain chlorinated polyethylene particles;

[0099] The chlorine content of the chlorinated polyethylene is 25wt%, the Mooney viscosity ML (1+4) at 100°C is 50, and the volatile matter content is 0.1wt%;

[0100] 2. Compounding: Add 0.014 kg of white carbon black and 0.55 L of sodium dodecylbenzene sulfonate aqueous solution into a reactor, adjust the stirring speed of the reactor to 40 rpm, stir at room temperature for 2.5 h, filter, dry at 105 ° C, add 0.011 kg of sulfonyl chloride into the reactor, adjust the stirring speed of the reactor to 40 rpm, stir at room temperature for 35 min, and obtain compound white carbon black;

[0101] The white carbon black is precipitated white carbon black with a particle size of 2 μm;

[0102] The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%;

[0103] 3. Reaction: 3.15kg of chlorinated polyethylene particles, 0.025kg of white carbon black, the composite white carbon black obtained in the second step of the composite step, and 0.009kg of azobisisobutyronitrile are added to the reactor. A UV lamp is fixed on the lid of the reactor. After the reactor is sealed, nitrogen is used to replace the air in the reactor, and then the UV lamp is turned on. The temperature in the reactor is raised to 42°C, the stirring speed is adjusted to 150rpm, and stirred for 11 minutes. A mixed gas of chlorine and sulfur dioxide is introduced into the reactor until the pressure in the reactor is 0.07MPa, and stirred for 11 minutes. The reactor is cooled and vented to room temperature and pressure, and chlorine is continued to be introduced into the reactor. and sulfur dioxide until the pressure in the reactor is 0.07MPa, stir for 11min, cool the reactor, exhaust the gas to room temperature and pressure, continue to introduce chlorine and sulfur dioxide into the reactor until the pressure in the reactor is 0.07MPa, stir for 11min, cool the reactor, exhaust the gas to room temperature and pressure, introduce nitrogen to purify the air in the reactor, add 0.025kg of active magnesium oxide into the reactor, stir for 18min, wash the materials in the reactor with water, filter, take the filtrate and filter residue respectively, recover the magnesium chloride in the filtrate, dry the filter residue at 85°C, and crush to obtain chlorosulfonated polyethylene;

[0104] The white carbon black is fumed white carbon black with a particle size of 20 nm;

[0105] The power of the ultraviolet lamp is 1 kW and the wavelength is 380 nm;

[0106] The volume ratio of chlorine to sulfur dioxide in the mixed gas of chlorine and sulfur dioxide is 1.1:1;

[0107] The particle size of the active magnesium oxide is 1 μm.

[0108] That is, this comparative example is based on the high-efficiency preparation method of chlorosulfonated polyethylene in Example 2, omitting the use of small chlorinated polyethylene particles and the mixing of small chlorinated polyethylene particles with white carbon black, and directly adding the white carbon black in the mixing step 2 in Example 2 to the reaction step 4.

[0109] Test Example 1

[0110] The chlorine content in the chlorosulfonated polyethylene prepared in Example 1-3 and Comparative Example 1-2 was measured according to the oxygen bottle combustion method in the national standard GB / T 9872-1998, and the sulfur content in the chlorosulfonated polyethylene prepared in Example 1-3 and Comparative Example 1-2 was measured according to the oxygen bottle combustion method in the national standard GB / T 4497-2010. The measurement results are as follows:

[0111]

[0112] Test Example 2

[0113] The chlorosulfonated polyethylene prepared in Example 1-3 and Comparative Example 1-2 were respectively added to an internal mixer with magnesium oxide, carbon black N330, carbon black N774, trioctyl trimellitate TOTM, pentaerythritol, accelerator DPTT, and chlorinated paraffin oil in a mass ratio of 100:10:20:20:15:4:2:3 to obtain a mixed rubber, which was then vulcanized on a flat vulcanizer, the vulcanization temperature was adjusted to 160°C, and the positive vulcanization time t90 was measured. The measurement results are as follows:

[0114]

[0115] Test Example 3

[0116] The chlorosulfonated polyethylene prepared in Example 1-3 and Comparative Example 1-2 were respectively added to an internal mixer with magnesium oxide, carbon black N330, carbon black N774, trioctyl trimellitate TOTM, pentaerythritol, accelerator DPTT, and chlorinated paraffin oil in a mass ratio of 100:10:20:20:15:4:2:3 to obtain a mixed rubber, and then vulcanized at 160°C according to the respective positive vulcanization times determined in Test Example 2, cooled, and then the tensile strength, elongation at break, and tear strength were measured. The measurement results are as follows:

[0117]

[0118] Test Example 4

[0119] The chlorosulfonated polyethylene prepared in Examples 1-3 and Comparative Examples 1-2 were respectively added to an internal mixer with magnesium oxide, carbon black N330, carbon black N774, trioctyl trimellitate TOTM, pentaerythritol, accelerator DPTT, and chlorinated paraffin oil in a mass ratio of 100:10:20:20:15:4:2:3 to obtain a mixed rubber, and then vulcanized at 160°C according to the respective positive vulcanization times determined in Test Example 2, cooled, and then the tensile strength and elongation at break were measured, and then after heat aging in hot air at 110°C for 240h, the tensile strength and elongation at break were tested, and the change rate of tensile strength and the change rate of elongation at break were calculated. The calculation results are as follows:

[0120]

[0121] After analyzing the results of Test Examples 1-4, it was found that the chlorosulfonated polyethylene prepared in Comparative Example 1 had lower chlorine and sulfur contents than the chlorosulfonated polyethylene prepared in Example 2, a slightly longer vulcanization time, and poorer tensile strength, elongation at break, tear strength, and heat aging resistance after vulcanization, and more white carbon black was used in the preparation;

[0122] Compared with the chlorosulfonated polyethylene prepared in Example 2, the chlorosulfonated polyethylene prepared in Comparative Example 2 has lower chlorine and sulfur contents, longer vulcanization time, and poorer tensile strength, elongation at break, tear strength, and heat aging resistance after vulcanization.

[0123] Unless otherwise specified, all percentages used in the present invention are by mass.

[0124] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing chlorosulfonated polyethylene with high efficiency, characterized in that: It consists of the following steps: grinding, mixing, compounding, and reacting; The grinding comprises grinding the chlorinated polyethylene separately to obtain large chlorinated polyethylene particles and small chlorinated polyethylene particles; The particle size of the large chlorinated polyethylene particles is 100-120 mesh; The particle size of the small chlorinated polyethylene particles is 325 mesh; The mixing comprises mixing small chlorinated polyethylene particles and a hexadecyltrimethylammonium chloride aqueous solution, stirring at room temperature, filtering, and drying to obtain surface-treated small chlorinated polyethylene particles; mixing white carbon black and a sodium dodecylbenzene sulfonate aqueous solution, stirring at room temperature, filtering, and drying to obtain surface-treated white carbon black; mixing the surface-treated small chlorinated polyethylene particles and water, stirring at room temperature, adding the surface-treated white carbon black, continuing stirring after the addition, filtering, and drying to obtain mixed small chlorinated polyethylene particles; In the mixing, the dosage ratio of small chlorinated polyethylene particles, hexadecyltrimethylammonium chloride aqueous solution, white carbon black, sodium dodecylbenzenesulfonate aqueous solution and water is 1-1.1kg:10-12L:0.024-0.026kg:0.9-1L:10-12L; In the mixing, the white carbon black is fumed white carbon black with a particle size of 20 nm; The composite comprises mixing white carbon black and an aqueous solution of sodium dodecylbenzene sulfonate, stirring at room temperature, filtering, drying, mixing with sulfonyl chloride, and stirring at room temperature to obtain composite white carbon black; In the compounding, the amount ratio of white carbon black, sodium dodecylbenzenesulfonate aqueous solution and sulfonyl chloride is 0.014-0.015kg:0.5-0.6L:0.01-0.012kg; In the composite, the white carbon black is precipitated white carbon black with a particle size of 2 μm; The reaction comprises adding large chlorinated polyethylene particles, mixed small chlorinated polyethylene particles, composite white carbon black and azobisisobutyronitrile into a reactor, fixing an ultraviolet lamp on the reactor cover, sealing the reactor, replacing the air in the reactor with nitrogen, turning on the ultraviolet lamp, raising the temperature in the reactor to 40-45° C., stirring for 10-11 minutes, introducing a mixed gas of chlorine and sulfur dioxide into the reactor until the pressure in the reactor is 0.06-0.07 MPa, stirring for 10-11 minutes, cooling the reactor, exhausting the gas to room temperature and pressure, and continuing to introduce a mixed gas of chlorine and sulfur dioxide into the reactor until the pressure in the reactor is 0.06-0.07 MPa. The pressure in the reactor is 0.06-0.07MPa, and the reactor is stirred for 10-11 minutes. The reactor is cooled and vented to normal temperature and pressure, and a mixed gas of chlorine and sulfur dioxide is continuously introduced into the reactor until the pressure in the reactor is 0.06-0.07MPa, and the reactor is stirred for 10-11 minutes. The reactor is cooled and vented to normal temperature and pressure, and nitrogen is introduced to purify the air in the reactor. Active magnesium oxide is added into the reactor, and the mixture is stirred. The materials in the reactor are washed with water, and then filtered. The filtrate and the filter residue are respectively taken, and the magnesium chloride in the filtrate is recovered. The filter residue is dried and crushed to obtain chlorosulfonated polyethylene. The dosage ratio of the small chlorinated polyethylene particles in the mixture, the white carbon black in the composite, the large chlorinated polyethylene particles in the reaction, azobisisobutyronitrile, and active magnesium oxide is 1-1.1kg: 0.014-0.015kg: 2-2.3kg: 0.008-0.009kg: 0.024-0.026kg.

2. The method for preparing high-efficiency chlorosulfonated polyethylene according to claim 1, characterized in that: The chlorinated polyethylene has a chlorine content of 25 wt %, a Mooney viscosity ML (1+4) of 50 at 100° C., and a volatile matter content of 0.1 wt %.

3. The method for preparing high-efficiency chlorosulfonated polyethylene according to claim 1, characterized in that: In the mixing, the concentration of the hexadecyltrimethylammonium chloride aqueous solution is 1wt%; The concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%; The addition rate of the surface treated white carbon black is 0.04-0.05 kg / min.

4. The method for preparing high-efficiency chlorosulfonated polyethylene according to claim 1, characterized in that: In the compounding, the concentration of the sodium dodecylbenzenesulfonate aqueous solution is 1wt%.

5. The method for preparing high-efficiency chlorosulfonated polyethylene according to claim 1, characterized in that: In the reaction, the power of the ultraviolet lamp is 1 kW and the wavelength is 380 nm; The volume ratio of chlorine to sulfur dioxide in the mixed gas of chlorine and sulfur dioxide is 1-1.2:1; The particle size of the active magnesium oxide is 1 μm.

Images