Cationic electrolyte functional modified cationic emulsion polymer water clarifier and preparation method thereof

Abstract

The invention discloses a cationic electrolyte functional modified cationic emulsion polymer water clarifier and a preparation method thereof. The preparation method comprises the following steps: firstly, adding a water-phase ingredient consisting of cationic polyelectrolyte, an acrylamide monomer, an oleophylic cationic monomer, a complexing agent, a composite water-soluble initiation system and deionized water into an oil-phase ingredient consisting of an organic solvent, a composite emulsifier system and an oil-soluble initiator, then adding an emulsifier for emulsifying, filling nitrogen, cooling, then sequentially adding a reducing agent and a phase inversion agent, and finally adding a water-phase initiator and an oil-phase initiator to obtain the water-phase emulsion. Obtaining the water clarifier. The prepared high-activity cationic emulsion polymer water clarifier can be applied to offshore oilfield oil-water separation on a large scale, can also replace cationic polymer dry powder on a large scale, is applied to oily sewage and industrial wastewater with high organic matter content, and has a very wide prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of high molecular polymer preparation, and specifically relates to a cationic electrolyte functional modified cationic emulsion polymer water purifier and a preparation method thereof. Background Art

[0002] Cationic polyacrylamide (CPAM) is a linear polymer compound. Due to its multiple active groups, it can adsorb and form hydrogen bonds with many substances. It can flocculate negatively charged colloids and has the functions of decolorization, adsorption, bonding, and turbidity removal. It is widely used in the treatment of wastewater with high organic impurities in industries such as papermaking, dyeing and finishing, mineral processing, oil fields, food, and brewing. It is particularly suitable for the dehydration of urban sludge, papermaking sludge and other industrial sludge. The space of offshore oil platforms is limited, the oil, gas and water separation process of offshore oil fields is short, the sewage treatment process is short, the output liquid treatment volume is large, and the sewage treatment effect requirements are high; with the advancement of "zero emission" measures, conventional inorganic polymer water clarifiers have the characteristics of large alum flowers, large sludge production, low pH value, and strong corrosiveness, and are gradually being replaced as an inevitable trend.

[0003] Therefore, for offshore oilfield platforms, where the working space is relatively small, there is an urgent need for a highly active cationic polyacrylamide that dissolves quickly and has strong water-cleaning effect for oil-water separation. Summary of the invention

[0004] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a cationic electrolyte functional modified cationic emulsion polymer water-clearing agent and a preparation method thereof.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for preparing a cationic electrolyte functional modified cationic emulsion polymer water clarifier comprises the following steps:

[0007] (I) fully mixing and stirring the organic solvent, the composite emulsifier system and the oil-soluble initiator to dissolve to obtain an oil phase formulation;

[0008] (II) fully mixing and stirring the cationic polyelectrolyte, acrylamide monomer, lipophilic cationic monomer, complexing agent, composite water-soluble initiator system and deionized water to dissolve and obtain aqueous phase ingredients;

[0009] (III) slowly adding the water phase ingredients to the oil phase ingredients under stirring conditions, emulsifying with an emulsifier, and after the particle size is tested to be qualified, nitrogen is charged into the emulsified emulsion and stirred;

[0010] (IV) Cooling step (III) stirring the reaction mixture, and keeping nitrogen filling during the cooling process;

[0011] (V) preparing a reducing agent solution;

[0012] (VI) slowly adding the reducing agent solution dropwise to the cooled reactant in step (IV) using a metering pump;

[0013] (VII) When the temperature of the reactants reaches 50°C, the reducing agent solution is added dropwise at a constant temperature until the addition of the reducing agent solution is complete, and the reaction temperature is first raised to 60°C for 1 hour, and then raised to 70°C for 1 hour. After the reaction is complete, nitrogen filling is stopped;

[0014] (VIII) adding a phase inversion agent to the product of step (VII) to invert the phase, thereby obtaining a cationic emulsion polymer water-clearing agent.

[0015] In the above technical solution, the organic solvent is compounded by No. 3 white oil and No. 5 white oil in a mass ratio of 1:1.

[0016] In the above technical solution, the composite emulsifier system is formed by compounding Span 80 and Tween 60 in a mass ratio of 4:1.

[0017] In the above technical scheme, the cationic polyelectrolyte is a copolymer of DADMAC and methacryloyloxyethyl dimethyl ammonium chloride, and the compounding mass ratio of DADMAC and methacryloyloxyethyl dimethyl ammonium chloride monomers is 1:2; and the viscosity of the cationic polyelectrolyte is 200cp~300cp. The present invention adopts the inverse emulsion polymerization technology, and adds 3%~5% of cationic polyelectrolyte before polymerization to functionally modify the cationic emulsion polymer. The cationic polyelectrolyte itself has a strong charge coagulation effect. Adding the polyelectrolyte to the preparation process of the cationic emulsion polymer has a synergistic effect on the cationic emulsion polymer; in addition, by adding the cationic polyelectrolyte template in the polymerization process, the cationic functional groups of the obtained functionally modified emulsion polymer are more evenly distributed, so that the formed functionally modified cationic emulsion polymer has high stability and strong oil-water separation effect, and a high-activity high-molecular-weight cationic emulsion polymer water clarifier with good oil-water separation performance is obtained.

[0018] In the above technical scheme, the lipophilic cationic monomer is compounded by methacryloyloxyethyl dimethyl benzyl ammonium chloride and dimethyl dodecyl allyl ammonium chloride in a mass ratio of 2: 1. The present invention adds two lipophilic monomers with different structures, wherein methacryloyloxyethyl dimethyl benzyl ammonium chloride has a benzene ring structure and has a natural affinity with aromatic hydrocarbons in crude oil, and dimethyl dodecyl allyl ammonium chloride has a good affinity with long-chain hydrocarbons in crude oil, and the polymers of the two monomers are also very water-soluble. The two lipophilic cationic monomers are used in combination, and the prepared cationic polymer water-clearing agent has better lipophilicity, is more conducive to capturing oil droplets and water-in-oil type latex in wastewater, and achieves a better water-clearing effect.

[0019] In the above technical solution, the complexing agent is prepared by compounding any two of sodium ethylenediaminetetraacetate, sodium ethylenediaminetetrapropionate or sodium diethylenetriaminepentaacetate in a mass ratio of 1:1.

[0020] In the above technical scheme, the oil-soluble initiator is compounded by azobisisobutyronitrile and azobisisovaleronitrile in a mass ratio of 1:1; the composite water-soluble initiator system is compounded by ammonium persulfate, azobisisobutylimidazoline hydrochloride and azobisisobutylamidine hydrochloride in a mass ratio of 4:1:1. Since the decomposition temperatures of thermal initiators are different, when multiple thermal initiators are used in combination, they can be decomposed at different temperatures, and step-by-step polymerization can be achieved, thereby increasing the molecular weight of the polymer, and at the same time, the concentrated decomposition of one initiator can be reduced, resulting in excessive branching structure and reduced product solubility. Similarly, the present invention simultaneously uses two oil-soluble initiators with different decomposition temperatures, which can complement the water-soluble composite initiator system, and gradually initiate polymerization in stages, thereby increasing the molecular weight of the polymer and reducing the residual monomer content.

[0021] In the above technical solution, the duration of emulsification of the emulsifier in step (III) is 30 minutes.

[0022] In the above technical solution, in the step (III), the stirring reaction time after nitrogen is charged into the emulsified emulsion is more than 2 hours.

[0023] In the above technical solution, the step (IV) cools the mixture after the stirring reaction in the step (III) to 5°C to 10°C, and the cooling is carried out by cooling brine.

[0024] In the above technical solution, the mass concentration of the reducing agent solution in step (V) is 2% to 3%, and the solvent of the reducing agent solution is deionized water.

[0025] In the above technical solution, the reducing agent is prepared by compounding sodium bisulfite and sodium pyrosulfite in a mass ratio of 1:1.

[0026] In the above technical scheme, the phase inversion agent is compounded by any two of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether or polyoxyethylene ether natural fatty alcohol in a mass ratio of 1:1; the amount of the phase inversion agent added is 1% to 1.5% of the total mass of the reaction product of step (VII). The reason why the inverse emulsion needs phase inversion is that before the phase inversion, the surface of the latex particles is well wrapped by the emulsifier, and the product cannot be quickly dissolved in water. After adding the phase inversion agent, a hydrophilic channel is left on the surface of the latex particles. Once the emulsion is dispersed in water, water can quickly enter the latex particles from the hydrophilic channel, thereby achieving the purpose of rapid dissolution. Adding two emulsifiers with HLB greater than 10 to form a phase inversion agent, the strength of the hydrophilic channel formed on the surface of the latex particles is different, which can adjust the dissolution time of the emulsion and the speed at which water enters the latex particles, thereby adjusting the solubility of the high lipophilic and low viscosity cationic emulsion polymer water-clearing agent.

[0027] A cationic electrolyte functional modified cationic emulsion polymer water purifier is prepared by the above method. The viscosity of the water purifier is less than 450cp; its molecular weight is greater than 8 million, and it can be used as a water purifier to treat industrial wastewater and as a sludge dehydrating agent.

[0028] A cationic electrolyte functional modified cationic emulsion polymer water purifier, the components of the water purifier and the mass fractions of each component are:

[0029]

[0030] Principle of the present invention:

[0031] The invention adopts reverse emulsion polymerization, cationic polyelectrolyte as a template, and a low-temperature composite initiation system to initiate polymerization in stages to prepare a highly active cationic emulsion polymer water-clearing agent.

[0032] Cationic polyelectrolytes themselves have a strong charge coagulation effect. Adding polyelectrolytes to the preparation process of cationic emulsion polymers can enhance the cationic emulsion polymers. The resulting functionally modified emulsion has high stability and a strong oil-water separation effect.

[0033] The inverse emulsion polymerization technology adds 3% to 5% of cationic polyelectrolyte before polymerization to functionalize the cationic emulsion polymer to obtain a high-activity, high-molecular-weight cationic emulsion polymer water-clearing agent with high activity and good oil-water separation performance.

[0034] High molecular weight cationic emulsion polymers have the characteristics of high effective content and high molecular weight. A very low dosage can form a flocculation effect comparable to that of inorganic polymer water-clearing agents. The amount of sludge produced is much lower than that produced by inorganic polymers, and it is almost non-corrosive to equipment and facilities. It can be perfectly combined with the oil-water separation process of offshore oil production platforms, and can be widely used in areas such as offshore oil field platforms where the working space is relatively narrow.

[0035] The beneficial effects of the present invention are:

[0036] The invention provides a cationic electrolyte functional modified cationic emulsion polymer water clarifier and a preparation method thereof. By adding cationic polyelectrolytes of different viscosities into a water phase prepared by an inverse emulsion, a cationic polymer emulsion with uniform cationic functional group distribution in a cationic polyacrylamide molecular chain, high oil-water separation activity and a bulk viscosity of less than 350cp can be prepared. At the same time, the added cationic polyelectrolyte template has a coordinated synergistic effect on a high molecular weight cationic polymer emulsion. By adjusting the dosage of a composite emulsifier system and a phase transfer agent, high lipophilic ultra-low viscosity cationic polymer emulsions with different HLB values ​​can be prepared, thereby obtaining high lipophilic low viscosity cationic polymer emulsion products with different dissolution rates to meet the use in different occasions. A composite oil-soluble initiator is used, and two oil-soluble initiators have different decomposition temperatures, and can continue to decompose at 60°C to 80°C. The initiation can obtain a high lipophilic ultra-low viscosity cationic polymer emulsion product with lower residual monomers, which can better meet environmental protection requirements; a water-soluble composite initiation system is adopted, and different initiators are decomposed at different temperatures during the initial and mid-term reaction processes, and polymerization is initiated step by step, so as to prepare a high molecular weight emulsion polymer product; by controlling the speed of dripping the reducing agent, the reaction speed can be controlled, and the reaction heat can be adjusted to be slowly released, so as to obtain a high lipophilic ultra-low viscosity cationic polymer emulsion product with higher molecular weight and better solubility; by adding a complexing agent, metal ions can be complexed to improve the activity of the polymerized monomers, and the molecular weight of the high lipophilic low viscosity cationic emulsion polymer product can be improved; the cationic electrolyte functionalized modified cationic emulsion polymer water-clearing agent prepared by the present invention has high oil-water separation activity, low bulk viscosity, high molecular weight, good low temperature resistance, quick solubility and storage stability. DETAILED DESCRIPTION

[0037] In order to enable persons skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below through specific implementation methods.

[0038] Example 1

[0039] 280 parts of organic solvent, 20 parts of composite emulsifier system, 0.07 parts of oil-soluble initiator are added to the oil phase batching tank and stirred to dissolve; 15 parts of cationic polyelectrolyte, 145 parts of acrylamide monomer, 250 parts of lipophilic cationic monomer, 0.06 parts of complexing agent (sodium ethylenediaminetetraacetate: sodium ethylenediaminetetrapropionate = 1:1), 0.07 parts of composite water-soluble initiator system and 180 parts of deionized water are added to the water phase tank and stirred to dissolve; the material in the water phase tank is slowly poured into the oil phase tank while stirring, and emulsified for 30 minutes. After the particle size is tested to be qualified, the emulsified emulsion is poured into the polymerization kettle, stirring is started, and nitrogen is filled for more than 2 hours; the temperature of the reactor is reduced to 6°C with cooling brine, and nitrogen filling is continued; the mass concentration of the reducing agent aqueous solution is prepared to be 2% solution, the reducing agent solution is slowly dripped into the reactor with a metering pump, and the dropping speed of the reducing agent solution is adjusted according to the temperature rise. When the temperature of the reactor reaches 40°C, the reducing agent solution is added at a constant temperature until the configured reducing agent is completely added to the reactor. The total amount of reducing agent added is 0.05 parts. The temperature of the reactor is gradually raised to 50°C, 60°C and 70°C for 1 hour each, and nitrogen filling is stopped. The emulsion that has reacted completely is pumped into the post-processing reactor, and 13 parts of a phase transfer agent (nonylphenol polyoxyethylene ether: octylphenol polyoxyethylene ether = 1:1) is added to the post-processing reactor for phase transfer to obtain a high-activity high-molecular-weight cationic emulsion polymer water-clearing agent with a molecular weight of 8.24 million and a bulk viscosity of 352cp.

[0040] Example 2

[0041] 285 parts of organic solvent, 23 parts of composite emulsifier system, 0.06 parts of oil-soluble initiator are added to the oil phase batching tank and stirred and dissolved fully; 16 parts of cationic polyelectrolyte, 150 parts of acrylamide monomer, 250 parts of lipophilic cationic monomer, 0.06 parts of complexing agent (sodium ethylenediaminetetraacetate: sodium diethylenetriaminepentaacetate = 1:1), 0.07 parts of composite water-soluble initiator system and 190 parts of deionized water are added to the water phase tank and stirred and dissolved fully; the material in the water phase tank is slowly poured into the oil phase tank while stirring, and emulsified for 30 minutes. After the particle size is tested to be qualified, the emulsified emulsion is poured into the polymerization kettle, stirring is started, and nitrogen is filled for more than 2 hours; the temperature of the reactor is reduced to 6°C with cooling brine, and nitrogen filling is continued; the mass concentration of the reducing agent aqueous solution is prepared to be 2.5% solution, the reducing agent solution is slowly added to the reactor with a metering pump, and the dropping speed of the reducing agent solution is adjusted according to the temperature rise. When the temperature of the reactor reaches 40°C, the reducing agent solution is added at a constant temperature until the configured reducing agent is completely added to the reactor. The total amount of reducing agent added is 0.05 parts. The temperature of the reactor is gradually raised to 50°C, 60°C and 70°C for 1 hour each, and nitrogen filling is stopped. The emulsion that has reacted completely is pumped into the post-processing reactor, and 14 parts of a phase transfer agent (nonylphenol polyoxyethylene ether: polyoxyethylene ether natural fatty alcohol = 1:1) are added to the post-processing reactor for phase transfer to obtain a high-activity high-molecular-weight cationic emulsion polymer water-clearing agent with a molecular weight of 8.28 million and a bulk viscosity of 362cp.

[0042] Example 3

[0043] 290 parts of organic solvent, 24 parts of composite emulsifier system, 0.08 parts of oil-soluble initiator are added to the oil phase batching tank and stirred to dissolve; 17 parts of cationic polyelectrolyte, 160 parts of acrylamide monomer, 240 parts of lipophilic cationic monomer, 0.06 parts of complexing agent (sodium ethylenediaminetetrapropionate: sodium diethylenetriaminepentaacetate = 1:1), 0.07 parts of composite water-soluble initiator system and 185 parts of deionized water are added to the water phase tank and stirred to dissolve; the material in the water phase tank is slowly poured into the oil phase tank while stirring, and emulsified for 30 minutes. After the particle size is tested to be qualified, the emulsified emulsion is poured into the polymerization kettle, stirring is started, and nitrogen is filled for more than 2 hours; the temperature of the reactor is reduced to 6°C with cooling brine, and nitrogen filling is continued; the mass concentration of the reducing agent aqueous solution is prepared to be 2% solution, the reducing agent solution is slowly added to the reactor with a metering pump, and the dropping speed of the reducing agent solution is adjusted according to the temperature rise. When the temperature of the reactor rises to 40°C, the reducing agent solution is added at a constant temperature until the configured reducing agent is completely added to the reactor. The total amount of reducing agent added is 0.05 parts. The temperature of the reactor is gradually raised to 50°C, 60°C and 70°C for 1 hour each, and nitrogen filling is stopped. The emulsion that has reacted completely is pumped into the post-processing reactor, and 13 parts of a phase inversion agent (octylphenol polyoxyethylene ether: polyoxyethylene ether natural fatty alcohol = 1:1) is added to the post-processing reactor for phase inversion to obtain a high-activity high-molecular-weight cationic emulsion polymer water-clearing agent with a molecular weight of 8.33 million and a bulk viscosity of 378cp.

[0044] Example 4

[0045] 287 parts of organic solvent, 22 parts of composite emulsifier system, 0.09 parts of oil-soluble initiator are added to the oil phase batching tank and stirred and dissolved fully; 18 parts of cationic polyelectrolyte, 150 parts of acrylamide monomer, 260 parts of lipophilic cationic monomer, 0.06 parts of complexing agent (sodium ethylenediaminetetrapropionate: sodium diethylenetriaminepentaacetate = 1:1), 0.08 parts of composite water-soluble initiator system and 200 parts of deionized water are added to the water phase tank and stirred and dissolved fully; the material in the water phase tank is slowly poured into the oil phase tank while stirring, and emulsified for 30 minutes. After the particle size is tested to be qualified, the emulsified emulsion is poured into the polymerization kettle, stirring is started, and nitrogen is filled for more than 2 hours; the temperature of the reactor is reduced to 8°C with cooling brine, and nitrogen filling is continued; the mass concentration of the reducing agent aqueous solution is prepared to be 3% solution, the reducing agent solution is slowly dripped into the reactor with a metering pump, and the dropping speed of the reducing agent solution is adjusted according to the temperature rise. When the temperature of the reactor rises to 40°C, the reducing agent solution is added at a constant temperature until the configured reducing agent is completely added to the reactor. The total amount of reducing agent added is 0.05 parts. The temperature of the reactor is gradually raised to 50°C, 60°C and 70°C for 1 hour each, and nitrogen filling is stopped. The emulsion that has reacted completely is pumped into the post-processing reactor, and 14 parts of a phase transfer agent (nonylphenol polyoxyethylene ether: octylphenol polyoxyethylene ether = 1:1) is added to the post-processing reactor for phase transfer, and a high-activity high-molecular-weight cationic emulsion polymer water-clearing agent with a molecular weight of 8.36 million and a bulk viscosity of 358cp is obtained.

[0046] Example 5

[0047] 285 parts of organic solvent, 24 parts of composite emulsifier system, 0.06 parts of oil-soluble initiator are added to the oil phase batching tank and stirred to dissolve; 16 parts of cationic polyelectrolyte, 140 parts of acrylamide monomer, 250 parts of lipophilic cationic monomer, 0.06 parts of complexing agent (sodium ethylenediaminetetraacetate: sodium diethylenetriaminepentaacetate = 1:1), 0.08 parts of composite water-soluble initiator system and 195 parts of deionized water are added to the water phase tank and stirred to dissolve; the material in the water phase tank is slowly poured into the oil phase tank while stirring, and emulsified for 30 minutes. After the particle size is tested to be qualified, the emulsified emulsion is poured into the polymerization kettle, stirring is started, and nitrogen is filled for more than 2 hours; the temperature of the reactor is reduced to 9°C with cooling brine, and nitrogen filling is continued; the mass concentration of the reducing agent aqueous solution is prepared to be 2.5%, the reducing agent solution is slowly added to the reactor with a metering pump, and the dropping speed of the reducing agent solution is adjusted according to the temperature rise. When the temperature of the reactor reaches 40°C, the reducing agent solution is added at a constant temperature until the configured reducing agent is completely added to the reactor. The total amount of reducing agent added is 0.06 parts. The temperature of the reactor is gradually raised to 50°C, 60°C and 70°C for 1 hour each, and nitrogen filling is stopped. The emulsion that has reacted completely is pumped into the post-processing reactor, and 14 parts of a phase transfer agent (nonylphenol polyoxyethylene ether: polyoxyethylene ether natural fatty alcohol = 1:1) are added to the post-processing reactor for phase transfer to obtain a high-activity high-molecular-weight cationic emulsion polymer water-clearing agent with a molecular weight of 8.03 million and a bulk viscosity of 325cp.

[0048] Example 6

[0049] 290 parts of organic solvent, 23 parts of composite emulsifier system, 0.08 parts of oil-soluble initiator are added to the oil phase batching tank and stirred to dissolve; 18 parts of cationic polyelectrolyte, 160 parts of acrylamide monomer, 240 parts of lipophilic cationic monomer, 0.06 parts of complexing agent (sodium ethylenediaminetetrapropionate: sodium diethylenetriaminepentaacetate = 1:1), 0.07 parts of composite water-soluble initiator system and 185 parts of deionized water are added to the water phase tank and stirred to dissolve; the material in the water phase tank is slowly poured into the oil phase tank while stirring, and emulsified for 30 minutes. After the particle size is tested to be qualified, the emulsified emulsion is poured into the polymerization kettle, stirring is started, and nitrogen is filled for more than 2 hours; the temperature of the reactor is reduced to 8°C with cooling brine, and nitrogen filling is continued; the mass concentration of the reducing agent aqueous solution is prepared to be 2% solution, the reducing agent solution is slowly dripped into the reactor with a metering pump, and the dropping speed of the reducing agent solution is adjusted according to the temperature rise. When the temperature of the reactor rises to 40°C, the reducing agent solution is added at a constant temperature until the configured reducing agent is completely added to the reactor. The total amount of reducing agent added is 0.05 parts. The temperature of the reactor is gradually raised to 50°C, 60°C and 70°C for 1 hour each, and nitrogen filling is stopped. The emulsion that has reacted completely is pumped into the post-processing reactor, and 14 parts of a phase transfer agent (octylphenol polyoxyethylene ether: polyoxyethylene ether natural fatty alcohol = 1:1) is added to the post-processing reactor for phase transfer to obtain a high-activity high-molecular-weight cationic emulsion polymer water-clearing agent with a molecular weight of 8.27 million and a bulk viscosity of 396cp.

[0050] Example 7

[0051] 280 parts of organic solvent, 24 parts of composite emulsifier system, 0.06 parts of oil-soluble initiator are added to the oil phase batching tank and stirred to dissolve; 17 parts of cationic polyelectrolyte, 140 parts of acrylamide monomer, 240 parts of lipophilic cationic monomer, 0.06 parts of complexing agent (sodium ethylenediaminetetraacetate: sodium diethylenetriaminepentaacetate = 1:1), 0.08 parts of composite water-soluble initiator system and 180 parts of deionized water are added to the water phase tank and stirred to dissolve; the material in the water phase tank is slowly poured into the oil phase tank while stirring, and emulsified for 30 minutes. After the particle size is tested to be qualified, the emulsified emulsion is poured into the polymerization kettle, stirring is started, and nitrogen is filled for more than 2 hours; the temperature of the reactor is reduced to 7°C with cooling brine, and nitrogen filling is continued; the mass concentration of the reducing agent aqueous solution is prepared to be 2.5%, the reducing agent solution is slowly added to the reactor with a metering pump, and the dropping speed of the reducing agent solution is adjusted according to the temperature rise. When the temperature of the reactor rises to 40°C, the reducing agent solution is added at a constant temperature until the configured reducing agent is completely added to the reactor. The total amount of reducing agent added is 0.06 parts. The temperature of the reactor is gradually raised to 50°C, 60°C and 70°C for 1 hour each, and nitrogen filling is stopped. The emulsion that has reacted completely is pumped into the post-processing reactor, and 15 parts of a phase inversion agent (nonylphenol polyoxyethylene ether: octylphenol polyoxyethylene ether = 1:1) is added to the post-processing reactor for phase inversion to obtain a high-activity high-molecular-weight cationic emulsion polymer water-clearing agent with a molecular weight of 8.15 million and a bulk viscosity of 362cp.

[0052] The present invention prepares a series of cationic polyelectrolytes with suitable viscosity. By using the series of cationic polyelectrolytes, the cationic groups of the prepared cationic emulsion polymers can be more evenly distributed on the molecular chain, and the cationic polyelectrolytes can play a synergistic role. At the same time, long-chain lipophilic cationic monomer side groups are introduced through block polymerization to obtain a highly active cationic emulsion polymer water-clearing agent, which has broad application prospects in oil-water separation in offshore oil fields.

[0053] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a cationic electrolyte functional modified cationic emulsion polymer water clarifier, characterized in that: The following steps are involved: (I) fully mixing and stirring the organic solvent, the composite emulsifier system and the oil-soluble initiator to dissolve to obtain an oil phase formulation; (II) fully mixing and stirring the cationic polyelectrolyte, acrylamide monomer, lipophilic cationic monomer, complexing agent, composite water-soluble initiator system and deionized water to dissolve and obtain aqueous phase ingredients; (III) slowly adding the water phase ingredients to the oil phase ingredients under stirring conditions, emulsifying, and after the particle size is tested to be qualified, nitrogen is charged into the emulsified emulsion and stirred; (IV) Cooling step (III) stirring the reaction mixture, and keeping nitrogen filling during the cooling process; (V) preparing a reducing agent solution; (VI) slowly adding the reducing agent solution dropwise to the cooled reactant of step (IV) using a metering pump; (VII) When the temperature of the reactants reaches 50°C, the reducing agent solution is added dropwise at a constant temperature until the addition of the reducing agent solution is complete, and the reaction temperature is first raised to 60°C for 1 hour, and then raised to 70°C for 1 hour. After the reaction is complete, nitrogen filling is stopped; (VIII) adding a phase inversion agent to the product of step (VII) to invert the phase, thereby obtaining a cationic emulsion polymer water-clearing agent.

2. The method for preparing the cationic electrolyte functional modified cationic emulsion polymer water clarifier according to claim 1, characterized in that: The organic solvent is compounded by No. 3 white oil and No. 5 white oil in a mass ratio of 1:1; the composite emulsifier system is compounded by Span 80 and Tween 60 in a mass ratio of 4:1; and the oil-soluble initiator is compounded by azobisisobutyronitrile and azobisisovaleronitrile in a mass ratio of 1:

1.

3. The method for preparing the cationic electrolyte functional modified cationic emulsion polymer water clarifier according to claim 1, characterized in that: The cationic polyelectrolyte is a copolymer of DADMAC and methacryloyloxyethyl dimethyl ammonium chloride, and the mass ratio of DADMAC and methacryloyloxyethyl dimethyl ammonium chloride monomers is 1:2; and the viscosity of the cationic polyelectrolyte is 200cp-300cp; the lipophilic cationic monomer is compounded by methacryloyloxyethyl dimethyl benzyl ammonium chloride and dimethyl dodecyl allyl ammonium chloride in a mass ratio of 2:1; the complexing agent is compounded by any two of sodium ethylenediaminetetraacetate, sodium ethylenediaminetetrapropionate or sodium diethylenetriaminepentaacetate in a mass ratio of 1:1; the composite water-soluble initiator system is compounded by ammonium persulfate, azobisisobutylimidazoline hydrochloride and azobisisobutylamidine hydrochloride in a mass ratio of 4:1:

1.

4. The method for preparing the cationic electrolyte functional modified cationic emulsion polymer water clarifier according to claim 1, characterized in that: The emulsification time in the step (III) is 30 minutes; the stirring time after nitrogen is charged into the emulsified emulsion in the step (III) is more than 2 hours.

5. The method for preparing the cationic electrolyte functional modified cationic emulsion polymer water clarifier according to claim 1, characterized in that: In the step (IV), the mixture after the stirring reaction in the step (III) is cooled to 5°C to 10°C, and the cooling is carried out by cooling brine.

6. The method for preparing the cationic electrolyte functional modified cationic emulsion polymer water clarifier according to claim 1, characterized in that: The mass concentration of the reducing agent solution in step (V) is 2% to 3%, and the solvent of the reducing agent solution is deionized water.

7. The method for preparing the cationic electrolyte functional modified cationic emulsion polymer water clarifier according to claim 6, characterized in that: The reducing agent is prepared by mixing sodium bisulfite and sodium pyrosulfite in a mass ratio of 1:

1.

8. The method for preparing the cationic electrolyte functional modified cationic emulsion polymer water clarifier according to claim 1, characterized in that: The phase transfer agent is prepared by compounding any two of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether or polyoxyethylene ether natural fatty alcohol in a mass ratio of 1:1; the added amount of the phase transfer agent is 1% to 1.5% of the total mass of the reaction product of step (VII).

9. A cationic electrolyte functional modified cationic emulsion polymer water purifier, characterized in that: Prepared by the method of any one of claims 1 to 8, the modified cationic emulsion polymer water-clearing agent has a viscosity of less than 450cp; and a molecular weight of greater than 8 million.

10. A cationic electrolyte functional modified cationic emulsion polymer water purifier, characterized in that: The components of the water purifier and the mass fractions of each component are:

Images