Highly lipophilic, ultra-low viscosity cationic emulsion polymer clear water agent and method for preparing same

Abstract

The application provides a high-oil high cationic emulsion polymer water agent and a preparation method thereof, and belongs to the field of preparation of high molecular polymers. The application uses inverse emulsion polymerization, a polymer emulsification system and a low-temperature composite initiation system to initiate polymerization in sections, to prepare a series of polymer emulsifiers with special structures. The emulsion body viscosity is less than 300 cp, and the platform can be directly pumped into use without being separately dissolved. Long-chain oil-wet cationic monomer side groups are introduced through block polymerization, so that the high-oil high cationic emulsion polymer water agent with ultra-low viscosity is obtained. The low-temperature composite initiation system is used to initiate in sections, so that the high-oil high cationic emulsion polymer water agent product with ultra-low viscosity and high molecular weight is prepared. The product can be perfectly combined with the oil-water separation process of offshore oil platforms, and can be widely applied in the field of offshore oil platforms with relatively small operation space.

Description

Technical Field

[0001] The invention belongs to the field of preparation of high molecular polymers, and in particular relates to a highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent and a preparation method thereof. Background Art

[0002] Cationic polyacrylamide (CPAM) is a linear polymer compound. Due to its various active groups, it can adsorb and form hydrogen bonds with many substances. It can flocculate negatively charged colloids and has functions such as decolorization, adsorption, bonding, and turbidity removal. It is widely used in the treatment of wastewater with high organic impurity content in industries such as papermaking, dyeing and finishing, mineral processing, oilfields, food, and brewing. It is particularly suitable for the dewatering of municipal sludge, papermaking sludge, and other industrial sludge. Offshore oilfields have short oil, gas, and water separation processes, large volumes of produced fluids to be processed, and demanding high-quality wastewater treatment. With the advancement of "zero discharge" measures, conventional inorganic polymer water clarifiers have the disadvantages of large flocculants and sludge production, which significantly occupy limited offshore oil platform space and reduce oil-water separation processing speed. Furthermore, their low pH and strong corrosiveness can lead to rapid aging of oil-water treatment equipment and increase treatment costs. Therefore, the gradual replacement of inorganic polymer water clarifiers with organic polymer water clarifiers is inevitable.

[0003] In recent years, organic high-molecular-weight polymer water clarifiers have been developed and widely used in CNOOC's four offshore areas and overseas markets. However, powdered high-molecular-weight polymers dissolve slowly and require bulky dissolution equipment, reducing oil-water separation efficiency and occupying space on offshore production platforms. Solution-based high-molecular-weight polymer water clarifiers, in order to maintain a bulk viscosity below 500 cp, require an effective content of approximately 1%, resulting in prohibitive transportation costs and preventing widespread adoption. Furthermore, existing organic polymer solution-based water clarifiers exhibit limited lipophilicity and slow oil-water separation, hindering the goal of increasing reserves and production. Therefore, the development of higher-performing organic polymer water clarifiers is urgent. Summary of the Invention

[0004] In view of this, the present invention aims to propose a highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent and a preparation method thereof. The prepared highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent has the characteristics of strong lipophilicity, low bulk viscosity, high molecular weight, good low temperature resistance, quick solubility and storage stability.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows: a method for preparing a highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent comprises the following steps:

[0006] Step 1: Add organic solvent, self-made high-efficiency polymer emulsifier, and oil-soluble initiator into the oil phase batching tank and stir and dissolve them thoroughly;

[0007] Step 2: Add acrylamide monomer, long-chain lipophilic cationic monomer, complexing agent, composite water-soluble initiator system and deionized water into the water phase tank and stir thoroughly to dissolve;

[0008] Step 3: Slowly pump the material in the water phase tank into the oil phase tank while stirring the material in the oil phase tank during the pumping process. Then, use an emulsifier to emulsify the material in the oil phase tank for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into the reactor, stirred, and filled with nitrogen for more than 2 hours.

[0009] Step 4: Use cooling brine to lower the temperature of the reactor to 5-10°C and continue to keep nitrogen filling;

[0010] Step 5: Prepare the reducing agent solution, add oil and emulsifier, and emulsify it with an emulsifier for use. Use a metering pump to slowly add the reducing agent dropwise to the reactor, and adjust the reducing agent addition speed according to the temperature rise;

[0011] Step 6: When the temperature of the reactor reaches 50°C, add the reducing agent dropwise at a constant temperature until the prepared reducing agent is completely added to the reactor. Then, gradually increase the temperature of the reactor to 60°C and 70°C, react for one hour respectively, and then stop nitrogen charging;

[0012] Step 7: The fully reacted emulsion is pumped into a post-processing phase inversion kettle, and 1%-1.5% of a phase inversion agent is added to the phase inversion kettle to invert the phase to obtain a finished product of a high molecular weight cationic emulsion polymer water clarifier.

[0013] Furthermore, the organic solvent is a composite of No. 3 white oil and D80 solvent oil in a ratio of 1:1;

[0014] The self-made high-efficiency polymer emulsifier is a copolymer of three monomers: methyl methacrylate, tetradecyl acrylate, and hexadecyl acrylate. The monomer compounding ratio is 1:2:1, and the polymer emulsifier requires a viscosity of 1500-2500cp;

[0015] The oil-soluble initiator is a compound of azobisisobutyronitrile and azobisisovaleronitrile, and the weight ratio is 1:1.

[0016] Furthermore, the long-chain lipophilic cationic monomer is a compound of methacryloyloxyethyl dimethylbenzyl ammonium chloride and dimethyl dodecyl allyl ammonium chloride, and the weight ratio is 2:1.

[0017] Furthermore, the complexing agent is a compound of any two of sodium ethylenediaminetetraacetate, sodium ethylenediaminetetrapropionate, and sodium diethylenetriaminepentaacetate, with a ratio of 1:1.

[0018] Furthermore, the composite water-soluble initiator system comprises ammonium persulfate, azobisisobutylimidazoline hydrochloride and azobisisobutylamidine hydrochloride, and the ratio of the three initiators is 4:1:1.

[0019] Furthermore, the reducing agent is one or more of sodium bisulfite, sodium dithionite and sodium metabisulfite.

[0020] Furthermore, the phase inversion agent is any two of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether and polyoxyethylene ether natural fatty alcohol, with a ratio of 1:1.

[0021] Furthermore, the polymer raw material, in parts by mass, includes the following components:

[0022] 280-290 parts of organic solvent, 3-4 parts of homemade high-efficiency polymer emulsifier, 0.05-0.1 parts of oil-soluble initiator, 140-160 parts of acrylamide monomer, 240-260 parts of long-chain lipophilic cationic monomer, 0.05-0.08 parts of complexing agent, 0.07-0.08 parts of composite water-soluble initiator system and 0.05-0.06 parts of reducing agent.

[0023] A highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent is prepared using the above-mentioned method for preparing the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent, and has a bulk viscosity of less than 300 cp.

[0024] Furthermore, the molecular weight of the emulsion polymer water clarifier is higher than 8 million.

[0025] The highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent is a water-soluble high molecular weight polymer, and produces little sludge during deoiling of clear water. Furthermore, the bulk viscosity of the product is less than 300 cp, which satisfies the requirement of offshore oil platform pumping equipment that the system viscosity is less than 500 cp. Furthermore, the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent has high lipophilic activity and can rapidly achieve oil-water separation. In summary, the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent of the present invention is highly compatible with offshore platform oil-water separation processes and will be widely used in oil fields.

[0026] Compared with the prior art, the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent and its preparation method of the present invention have the following advantages:

[0027] (1) The present invention can prepare a cationic polymer emulsion with a bulk viscosity of less than 300 cp by adding polymer emulsifiers of different block structures to the oil phase of the inverse emulsion. The platform does not need to be dissolved separately and can be directly pumped into use. At the same time, by adjusting the block structure of the polymer emulsifier, a high lipophilicity and ultra-low viscosity cationic polymer emulsion with better low-temperature resistance can be prepared.

[0028] (2) By adjusting the amount of polymer emulsifier and phase inverting agent, high lipophilicity and ultra-low viscosity cationic polymer emulsions with different HLB values ​​can be prepared, thereby obtaining high lipophilicity and low viscosity cationic polymer emulsion products with different dissolution rates to meet the needs of different occasions;

[0029] (3) The present invention uses a composite oil-soluble initiator. The two oil-soluble initiators have different decomposition temperatures. Therefore, they can continue to decompose and initiate at 60-70°C, resulting in a highly lipophilic ultra-low viscosity cationic polymer emulsion product with lower residual monomers, better meeting environmental protection requirements.

[0030] (4) The present invention adopts a composite water-soluble initiation system. During the initial and mid-term reaction processes, different initiators decompose at different temperatures, initiating polymerization step by step, thereby facilitating the preparation of high molecular weight emulsion polymer products;

[0031] (5) The present invention can control the reaction rate by controlling the speed of adding the reducing agent, can adjust the slow release of the reaction heat, and can obtain a high-lipophilic ultra-low viscosity cationic polymer emulsion product with higher molecular weight and better solubility;

[0032] (6) The present invention can complex metal ions by adding a complexing agent, thereby increasing the activity of the polymerization monomer and increasing the molecular weight of the high-lipophilic and low-viscosity cationic emulsion polymer product;

[0033] (7) The highly lipophilic and ultra-low viscosity cationic emulsion polymer water purifier prepared by the inverse emulsion of the present invention is an organic high molecular polymer, does not contain free chloride ions, and is much less corrosive to equipment than inorganic high molecular water purifiers.

[0034] In summary, the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent prepared in the present invention has the following characteristics: strong lipophilicity, low bulk viscosity, high molecular weight, good low temperature resistance, quick solubility and storage stability. DETAILED DESCRIPTION

[0035] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0036] In view of the limited space of offshore oil platforms and the short sewage treatment process, a cationic polyacrylamide with high lipophilic activity and low viscosity that dissolves quickly and has strong water-clearing effect is needed for demulsification and flocculation of oil and water separation. The present invention provides a cationic emulsion polymer water-clearing agent with high lipophilicity and ultra-low viscosity and a preparation method thereof, which adopts inverse emulsion polymerization, a polymer emulsification system, and a low-temperature composite initiation system for segmented polymerization. The core technology of the present invention is: preparing a series of polymer emulsifiers with special structures. By using this series of polymer emulsifiers, the viscosity of the emulsion body can be obtained to be lower than 300cp. The platform does not need to be dissolved separately and can be directly pumped in for use. At the same time, long-chain lipophilic cationic monomer side groups are introduced through block polymerization to obtain a cationic emulsion polymer water-clearing agent with high lipophilicity and ultra-low viscosity; then, by segmented initiation through a low-temperature composite initiation system, a high molecular weight cationic emulsion polymer water-clearing agent with high lipophilicity and ultra-low viscosity can be prepared, which has broad application prospects in the field of oil-water separation in offshore oil fields.

[0037] The present invention provides a method for preparing a highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent, comprising the following steps:

[0038] Step 1: Add an organic solvent, a self-made high-efficiency polymer emulsifier, and an oil-soluble initiator into an oil phase batching tank, stir and dissolve them thoroughly; the organic solvent is a composite of No. 3 white oil and D80 solvent oil in a ratio of 1:1;

[0039] Step 2: adding acrylamide monomer, long-chain lipophilic cationic monomer, complexing agent, composite water-soluble initiator system and deionized water into the water phase tank and stirring and dissolving them thoroughly; the complexing agent is a mixture of any two of sodium ethylenediaminetetraacetate, sodium ethylenediaminetetrapropionate and sodium diethylenetriaminepentaacetate in a ratio of 1:1;

[0040] Step 3: Slowly pump the material in the water phase tank into the oil phase tank while stirring the material in the oil phase tank during the pumping process. Then, use an emulsifier to emulsify the material in the oil phase tank for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into the reactor, stirred, and filled with nitrogen for more than 2 hours.

[0041] Step 4: Use cooling brine to lower the temperature of the reactor to 5-10°C and continue to keep nitrogen filling;

[0042] Step 5: Prepare the reducing agent solution, add oil and emulsifier, and then emulsify it with an emulsifier for use. Slowly add the reducing agent dropwise to the reactor using a metering pump, and adjust the reducing agent addition speed according to the temperature rise. The reducing agent is one or more of sodium bisulfite, sodium dithionite, and sodium metabisulfite.

[0043] Step 6: When the temperature of the reactor reaches 50°C, add the reducing agent dropwise at a constant temperature until the prepared reducing agent is completely added to the reactor. Then, gradually increase the temperature of the reactor to 60°C and 70°C, react for one hour respectively, and then stop nitrogen charging;

[0044] Step 7: The fully reacted emulsion is pumped into a post-processing phase inversion kettle, and 1%-1.5% of a phase inversion agent is added to the phase inversion kettle to invert the phase to obtain a finished product of a high molecular weight cationic emulsion polymer water clarifier.

[0045] The self-made high-efficiency polymer emulsifier is a copolymer of three monomers: methyl methacrylate, tetradecyl acrylate, and hexadecyl acrylate. The monomer compounding ratio is 1:2:1, and the polymer emulsifier requires a viscosity of 1500-2500cp;

[0046] The present invention can prepare the emulsion polymer that bulk viscosity is lower than 300cp by adding self-made polymer emulsifier in the emulsion oil phase, the multi-block polymer emulsifier, the emulsifier length and short branched chain that forms combines, can increase the latex particle interface film thickness, can obtain larger interface strength again, the collision friction between the latex particles reduces, thereby reaches the purpose that reduces the emulsion bulk viscosity.In addition, the segment length of polymer emulsifier is very big on the low temperature resistance impact of emulsion, and the latex particle flowability that the polymer emulsifier that segment is short forms is good, thereby can improve the low temperature resistance of emulsion.Add polymer emulsifier along with the long-chain monomer in the structural unit from long to short, and the low temperature resistance of emulsion system is also from weak to strong.Its reason may be that the structural unit chain of polymer emulsifier is longer, and the temperature resistance of emulsion is worse, and this estimation is mainly because the freezing point of the polymer emulsifier structural unit is lower, and then the low temperature resistance of emulsion is just better.

[0047] In a further embodiment, the long-chain lipophilic cationic monomer is a compound of methacryloyloxyethyl dimethylbenzyl ammonium chloride and dimethyldodecyl allyl ammonium chloride, and the weight ratio is 2:1.

[0048] The present invention adds highly lipophilic cationic monomers, namely, methacryloyloxyethyl dimethylbenzyl ammonium chloride and dimethyl dodecyl allyl ammonium chloride, to an emulsion in a compounding ratio of 2:1. The two lipophilic monomers with different structures are added. The methacryloyloxyethyl dimethylbenzyl ammonium chloride has a benzene ring structure and has a natural affinity with aromatic hydrocarbons in crude oil, while the dimethyl dodecyl allyl ammonium chloride has a good affinity with long-chain hydrocarbons in crude oil. The polymers of the two monomers are also very water-soluble. The cationic polymer water purifier prepared by the composite use of the two lipophilic cationic monomers has better lipophilicity, is more conducive to capturing oil droplets and oil-in-water latex in wastewater, and achieves a better water purification effect.

[0049] In a further embodiment, the composite water-soluble initiator system is ammonium persulfate, azobisisobutylimidazoline hydrochloride and azobisisobutylamidine hydrochloride, and the ratio of the three initiators is 4:1:1; the oil-soluble initiator is a compound of azobisisobutyronitrile and azobisisovaleronitrile, and the weight compounding ratio is 1:1.

[0050] Because thermal initiators have different decomposition temperatures, when used in combination, multiple thermal initiators can decompose at different temperatures, enabling gradual, staged polymerization, thereby increasing polymer molecular weight while reducing the excessive branching that can occur when a single initiator decomposes in a concentrated manner, thereby reducing product solubility. Similarly, the present invention utilizes two oil-soluble initiators with different decomposition temperatures, complementing the composite water-soluble initiation system to initiate polymerization in a gradual, staged manner, thereby increasing polymer molecular weight and reducing residual monomer content.

[0051] In a further embodiment, the phase inversion agent is any two of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether and polyoxyethylene ether natural fatty alcohol, with a ratio of 1:1.

[0052] The reason inverse emulsions require phase inversion is that before the phase inversion, the surface of the latex particles is well coated with the emulsifier, making it difficult for the product to dissolve quickly when dispersed in water. The addition of a phase inversion agent creates hydrophilic channels on the surface of the latex particles. Once the emulsion is dispersed in water, water can quickly enter the latex particles through the hydrophilic channels, achieving rapid dissolution. By adding two emulsifiers with an HLB greater than 10 as a phase inversion agent, the hydrophilic channels formed on the surface of the latex particles vary in strength, adjusting the dissolution time of the emulsion and the speed at which water enters the latex particles, thereby adjusting the solubility of the highly lipophilic, low-viscosity cationic emulsion polymer water-clearing agent.

[0053] The polymer raw materials, in parts by mass, include the following components:

[0054] 280-290 parts of organic solvent, 3-4 parts of homemade high-efficiency polymer emulsifier, 0.05-0.1 parts of oil-soluble initiator, 140-160 parts of acrylamide monomer, 240-260 parts of long-chain lipophilic cationic monomer, 0.05-0.08 parts of complexing agent, 0.07-0.08 parts of composite water-soluble initiator system and 0.05-0.06 parts of reducing agent.

[0055] A highly lipophilic, ultra-low viscosity cationic emulsion polymer water clarifier is prepared using the aforementioned method for preparing a highly lipophilic, ultra-low viscosity cationic emulsion polymer water clarifier. Its bulk viscosity is less than 300 cp. The emulsion polymer water clarifier has a molecular weight greater than 8 million and can be used as a water clarifier for treating offshore platform wastewater, other oily industrial wastewater, and industrial wastewater sludge dehydration agents.

[0056] This patent uses inverse emulsion polymerization technology to produce a high-molecular-weight (molecular-weight over 8 million) cationic polymer with a bulk viscosity of less than 300 cp, resulting in a highly lipophilic high-molecular-weight cationic emulsion polymer water-clearing agent. This high-molecular-weight cationic emulsion water-clearing agent boasts high effective content and high molecular weight, achieving a flocculation effect comparable to inorganic polymer water-clearing agents at very low dosages. The amount of sludge produced is far less than that produced by inorganic polymers, and it is virtually non-corrosive to equipment and facilities, making it ideally suited for oil-water separation processes on offshore production platforms. This is particularly true in areas like offshore oilfield platforms, where operating space is relatively limited. Based on this, this technology produces a highly lipophilic, ultra-low-viscosity high-molecular-weight cationic emulsion polymer water-clearing agent, which can be used for large-scale offshore oilfield oil-water separation and can also replace cationic polymer powder on a large scale for applications in oily wastewater and industrial wastewater with high organic content, promising promising applications.

[0057] The present invention will be further described below with reference to the embodiments. The examples of the embodiments are intended to explain the present invention but should not be construed as limiting the present invention.

[0058] Example 1

[0059] 280 parts of organic solvent, 3.5 parts of polymer emulsifier, and 0.07 parts of oil-soluble initiator are added to an oil phase batching tank and stirred thoroughly to dissolve; 140 parts of acrylamide monomer, 260 parts of long-chain lipophilic cationic monomer, 0.06 parts of complexing agent, 0.07 parts of composite water-soluble initiator system, and deionized water are added to an aqueous phase tank and stirred thoroughly to dissolve; while stirring, the materials in the aqueous phase tank are slowly pumped into the oil phase tank and emulsified with an emulsifier for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into a reactor, stirred, and filled with nitrogen for more than 2 hours; the temperature of the reactor is lowered to 6°C with cooled brine and nitrogen is continued to be filled; a solution with a reducing agent concentration of 2% is prepared, and oil and emulsifier are added and emulsified for use, and the reducing agent is slowly added dropwise to the reactor using a metering pump, and the reducing agent addition rate is adjusted according to the temperature rise. After the reactor temperature reached 50°C, the initiator was added dropwise at a constant temperature until the prepared reducing agent was completely added to the reactor. The total amount of reducing agent added was 0.05 parts. The reactor temperature was gradually raised to 60°C and 70°C, and the reaction was continued for one hour each. The nitrogen filling was stopped. The emulsion after the reaction was completed was pumped into a post-processing phase inversion kettle, to which 1.1% of a phase inversion agent was added for phase inversion. The resulting product was a highly lipophilic and ultra-low viscosity cationic emulsion polymer water clarifier with a molecular weight of 8.62 million and a bulk viscosity of 285 cp.

[0060] Example 2

[0061] 285 parts of organic solvent, 3 parts of polymer emulsifier, and 0.06 parts of oil-soluble initiator are added to an oil phase batching tank and stirred thoroughly to dissolve; 150 parts of acrylamide monomer, 250 parts of long-chain lipophilic cationic monomer, 0.06 parts of complexing agent, 0.07 parts of composite water-soluble initiator system, and deionized water are added to an aqueous phase tank and stirred thoroughly to dissolve; while stirring, the materials in the aqueous phase tank are slowly pumped into the oil phase tank and emulsified with an emulsifier for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into a reactor, stirred, and filled with nitrogen for more than 2 hours; the temperature of the reactor is lowered to 6°C with cooled brine and nitrogen is continued to be filled; a solution with a reducing agent concentration of 2% is prepared, and oil and emulsifier are added and emulsified for use, and the reducing agent is slowly added dropwise to the reactor using a metering pump, and the reducing agent addition rate is adjusted according to the temperature rise. After the reactor temperature reached 50°C, the initiator was added dropwise at a constant temperature until the prepared reducing agent was completely added to the reactor. The total amount of reducing agent added was 0.05 parts. The reactor temperature was gradually raised to 60°C and 70°C, and the reaction was continued for one hour each. The nitrogen filling was stopped. The emulsion after the reaction was completed was pumped into a post-processing phase inversion kettle, to which 1.1% of a phase inversion agent was added for phase inversion. The resulting product was a highly lipophilic and ultra-low viscosity cationic emulsion polymer water clarifier with a molecular weight of 8.94 million and a bulk viscosity of 279 cp.

[0062] Example 3

[0063] 290 parts of organic solvent, 3 parts of polymer emulsifier, and 0.08 parts of oil-soluble initiator are added to an oil phase batching tank and stirred thoroughly to dissolve; 160 parts of acrylamide monomer, 240 parts of long-chain lipophilic cationic monomer, 0.06 parts of complexing agent, 0.07 parts of composite water-soluble initiator system, and deionized water are added to an aqueous phase tank and stirred thoroughly to dissolve; while stirring, the materials in the aqueous phase tank are slowly pumped into the oil phase tank and emulsified with an emulsifier for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into a reactor, stirred, and filled with nitrogen for more than 2 hours; the temperature of the reactor is lowered to 6°C with cooled brine and nitrogen is continued to be filled; a solution with a reducing agent concentration of 2% is prepared, and oil and emulsifier are added and emulsified for use, and the reducing agent is slowly added dropwise to the reactor using a metering pump, and the reducing agent addition rate is adjusted according to the temperature rise. After the reactor temperature reached 50°C, the initiator was added dropwise at a constant temperature until the prepared reducing agent was completely added to the reactor. The total amount of reducing agent added was 0.05 parts. The reactor temperature was gradually raised to 60°C and 70°C, and the reaction was continued for one hour each. The nitrogen filling was stopped. The emulsion after the reaction was completed was pumped into a post-processing phase inversion kettle, to which 1.2% of a phase inversion agent was added for phase inversion. The resulting product was a highly lipophilic and ultra-low viscosity cationic emulsion polymer water clarifier with a molecular weight of 9.33 million and a bulk viscosity of 283 cp.

[0064] Example 4

[0065] 280 parts of organic solvent, 4 parts of polymer emulsifier, and 0.09 parts of oil-soluble initiator are added to an oil phase batching tank and stirred thoroughly to dissolve; 150 parts of acrylamide monomer, 260 parts of long-chain lipophilic cationic monomer, 0.06 parts of complexing agent, 0.08 parts of composite water-soluble initiator system, and deionized water are added to an aqueous phase tank and stirred thoroughly to dissolve; while stirring, the materials in the aqueous phase tank are slowly pumped into the oil phase tank and emulsified with an emulsifier for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into a reactor, stirred, and filled with nitrogen for more than 2 hours; the temperature of the reactor is lowered to 8°C with cooled brine and nitrogen is continued to be filled; a solution with a reducing agent concentration of 2% is prepared, and oil and emulsifier are added and emulsified for use, and the reducing agent is slowly added dropwise to the reactor using a metering pump, and the reducing agent addition rate is adjusted according to the temperature rise. After the reactor temperature reached 50°C, the initiator was added dropwise at a constant temperature until the prepared reducing agent was completely added to the reactor. The total amount of reducing agent added was 0.05 parts. The reactor temperature was gradually raised to 60°C and 70°C, and the reaction was continued for one hour each. The nitrogen filling was stopped. The emulsion after the reaction was completed was pumped into a post-processing phase inversion kettle, to which 1.1% of a phase inversion agent was added for phase inversion. The resulting product was a highly lipophilic and ultra-low viscosity cationic emulsion polymer water clarifier with a molecular weight of 8.56 million and a bulk viscosity of 293 cp.

[0066] Example 5

[0067] 285 parts of organic solvent, 3.5 parts of polymer emulsifier, and 0.06 parts of oil-soluble initiator are added to an oil phase batching tank and stirred thoroughly to dissolve; 140 parts of acrylamide monomer, 250 parts of long-chain lipophilic cationic monomer, 0.06 parts of complexing agent, 0.08 parts of composite water-soluble initiator system, and deionized water are added to an aqueous phase tank and stirred thoroughly to dissolve; while stirring, the materials in the aqueous phase tank are slowly pumped into the oil phase tank and emulsified with an emulsifier for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into a reactor, stirred, and filled with nitrogen for more than 2 hours; the temperature of the reactor is lowered to 9°C with cooled brine and nitrogen is continued to be filled; a solution with a reducing agent concentration of 2% is prepared, and oil and emulsifier are added and emulsified for use, and the reducing agent is slowly added dropwise to the reactor using a metering pump, and the reducing agent addition rate is adjusted according to the temperature rise. After the reactor temperature reached 50°C, the initiator was added dropwise at a constant temperature until the prepared reducing agent was completely added to the reactor. The total amount of reducing agent added was 0.06 parts. The reactor temperature was gradually raised to 60°C and 70°C, and the reaction was continued for one hour each. The nitrogen filling was stopped. The emulsion after the reaction was completed was pumped into a post-processing phase inversion kettle, to which 1.1% of a phase inversion agent was added for phase inversion. The resulting product was a highly lipophilic and ultra-low viscosity cationic emulsion polymer water clarifier with a molecular weight of 8.47 million and a bulk viscosity of 288 cp.

[0068] Example 6

[0069] 290 parts of organic solvent, 3 parts of polymer emulsifier, and 0.08 parts of oil-soluble initiator are added to an oil phase batching tank and stirred thoroughly to dissolve; 160 parts of acrylamide monomer, 240 parts of long-chain lipophilic cationic monomer, 0.06 parts of complexing agent, 0.07 parts of composite water-soluble initiator system, and deionized water are added to an aqueous phase tank and stirred thoroughly to dissolve; while stirring, the materials in the aqueous phase tank are slowly pumped into the oil phase tank and emulsified with an emulsifier for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into a reactor, stirred, and filled with nitrogen for more than 2 hours; the temperature of the reactor is lowered to 8° C. with cooled brine and nitrogen is continued to be filled; a solution with a reducing agent concentration of 2% is prepared, and oil and emulsifier are added and emulsified for use, and the reducing agent is slowly added dropwise to the reactor using a metering pump, and the reducing agent addition rate is adjusted according to the temperature rise. After the reactor temperature reached 50°C, the initiator was added dropwise at a constant temperature until the prepared reducing agent was completely added to the reactor. The total amount of reducing agent added was 0.05 parts. The reactor temperature was gradually raised to 60°C and 70°C, and the reaction was continued for one hour each. The nitrogen filling was stopped. The emulsion after the reaction was completed was pumped into a post-processing phase inversion kettle, to which 1.1% of a phase inversion agent was added for phase inversion. The resulting product was a highly lipophilic and ultra-low viscosity cationic emulsion polymer water clarifier with a molecular weight of 9.45 million and a bulk viscosity of 263 cp.

[0070] Example 7

[0071] 280 parts of organic solvent, 4 parts of polymer emulsifier, and 0.06 parts of oil-soluble initiator are added to an oil phase batching tank and stirred thoroughly to dissolve; 140 parts of acrylamide monomer, 240 parts of long-chain lipophilic cationic monomer, 0.06 parts of complexing agent, 0.08 parts of composite water-soluble initiator system, and deionized water are added to an aqueous phase tank and stirred thoroughly to dissolve; while stirring, the materials in the aqueous phase tank are slowly pumped into the oil phase tank and emulsified with an emulsifier for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into a reactor, stirred, and filled with nitrogen for more than 2 hours; the temperature of the reactor is lowered to 7°C with cooled brine and nitrogen is continued to be filled; a solution with a reducing agent concentration of 2% is prepared, and oil and emulsifier are added and emulsified for use, and the reducing agent is slowly added dropwise to the reactor using a metering pump, and the reducing agent addition rate is adjusted according to the temperature rise. After the reactor temperature reached 50°C, the initiator was added dropwise at a constant temperature until the prepared reducing agent was completely added to the reactor. The total amount of reducing agent added was 0.06 parts. The reactor temperature was gradually raised to 60°C and 70°C, and the reaction was continued for one hour each. The nitrogen filling was then stopped. The emulsion that had completed the reaction was pumped into a post-processing phase inversion kettle, to which 1.1% of a phase inversion agent was added for phase inversion. The resulting product was a highly lipophilic and ultra-low viscosity cationic emulsion polymer water clarifier with a molecular weight of 8.97 million and a bulk viscosity of 294 cp.

[0072] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent, characterized in that: The steps include: Step 1: Add organic solvent, self-made high-efficiency polymer emulsifier, and oil-soluble initiator into the oil phase batching tank and stir and dissolve them thoroughly; Step 2: Add acrylamide monomer, long-chain lipophilic cationic monomer, complexing agent, composite water-soluble initiator system and deionized water into the water phase tank and stir thoroughly to dissolve; Step 3: Slowly pump the material in the water phase tank into the oil phase tank while stirring the material in the oil phase tank during the pumping process. Then, use an emulsifier to emulsify the material in the oil phase tank for 30 minutes. After the particle size is tested and qualified, the emulsified emulsion is pumped into the reactor, stirred, and filled with nitrogen for more than 2 hours. Step 4: Use cooling brine to lower the temperature of the reactor to 5-10°C and continue to keep nitrogen filling; Step 5: Prepare the reducing agent solution, add oil and emulsifier, and emulsify it with an emulsifier for use. Use a metering pump to slowly add the reducing agent dropwise to the reactor, and adjust the reducing agent addition speed according to the temperature rise; Step 6: When the temperature of the reactor reaches 50°C, add the reducing agent dropwise at a constant temperature until the prepared reducing agent is completely added to the reactor. Then, gradually increase the temperature of the reactor to 60°C and 70°C, react for one hour respectively, and then stop nitrogen charging; Step 7: The emulsion after the reaction is completed is poured into a post-processing phase inversion kettle, and 1%-1.5% of a phase inversion agent is added to the phase inversion kettle to invert the phase, thereby obtaining a finished product of a high molecular weight cationic emulsion polymer water clarifier; The organic solvent is a composite of No. 3 white oil and D80 solvent oil in a ratio of 1:1; The self-made high-efficiency polymer emulsifier is a copolymer of three monomers: methyl methacrylate, tetradecyl acrylate, and hexadecyl acrylate. The monomer compounding ratio is 1:2:1, and the polymer emulsifier requires a viscosity of 1500-2500cp; The oil-soluble initiator is a compound of azobisisobutyronitrile and azobisisovaleronitrile, with a weight ratio of 1:1; The long-chain lipophilic cationic monomer is a compound of methacryloyloxyethyl dimethylbenzyl ammonium chloride and dimethyl dodecyl allyl ammonium chloride, and the weight ratio is 2:

1.

2. The method for preparing the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent according to claim 1, wherein: The complexing agent is a compound of any two of sodium ethylenediaminetetraacetate, sodium ethylenediaminetetrapropionate, and sodium diethylenetriaminepentaacetate, with a ratio of 1:

1.

3. The method for preparing the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent according to claim 1, wherein: The composite water-soluble initiator system comprises ammonium persulfate, azobisisobutylimidazoline hydrochloride and azobisisobutylamidine hydrochloride, and the ratio of the three initiators is 4:1:

1.

4. The method for preparing the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent according to claim 1, wherein: The reducing agent is one or more of sodium bisulfite, sodium dithionite and sodium metabisulfite.

5. The method for preparing the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent according to claim 1, characterized in that: The phase inversion agent is any two of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether and polyoxyethylene ether natural fatty alcohol, with a ratio of 1:

1.

6. The method for preparing the highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent according to claim 1, characterized in that: The polymer raw materials, in parts by mass, include the following components: 280-290 parts of organic solvent, 3-4 parts of homemade high-efficiency polymer emulsifier, 0.05-0.1 parts of oil-soluble initiator, 140-160 parts of acrylamide monomer, 240-260 parts of long-chain lipophilic cationic monomer, 0.05-0.08 parts of complexing agent, 0.07-0.08 parts of composite water-soluble initiator system and 0.05-0.06 parts of reducing agent.

7. A highly lipophilic and ultra-low viscosity cationic emulsion polymer water clarifier, characterized in that: The cationic emulsion polymer water-clearing agent with high lipophilicity and ultra-low viscosity is prepared by the preparation method of any one of claims 1 to 6, and its bulk viscosity is less than 300 cp.

8. The highly lipophilic and ultra-low viscosity cationic emulsion polymer water-clearing agent according to claim 7, characterized in that: The molecular weight of the emulsion polymer water clarifier is higher than 8 million.