阅读说明：本技术 一种基于高分子附聚技术制备大粒径聚丁二烯胶乳的方法 (Method for preparing large-particle-size polybutadiene latex based on polymer agglomeration technology ) 是由 曾伟华 杨坡 许家福 邹永春 于 2021-08-10 设计创作，主要内容包括：本申请涉及一种基于高分子附聚技术制备大粒径聚丁二烯胶乳的方法,属于合ABS成树脂领域。传统的高分子附聚方法使用的附聚剂均为丙烯酸酯与丙烯酸(或甲基丙烯酸,衣康酸等)共聚物。这类附聚剂的特点就是在聚合过程中要使用大量的吸附性乳化剂如十二烷基硫酸钠等,因而会对制备大粒径聚丁二烯胶乳的接枝聚合和絮凝过程产生影响,容易引发二次成核和乳化剂残留,影响最终的ABS树脂质量。本发明采用乙烯基硫酸盐或乙烯基磺酸盐作为反应型乳化剂和离子型共聚单体代替了传统的丙烯酸共聚单体,在制备附聚剂过程中不适用任何吸附性乳化剂,且与反应型乳化剂共聚后的聚丙烯酸乳液有很好的附聚效果,可以制备出300nm至500nm左右范围内的窄分布聚丁二烯胶乳。(The application relates to a method for preparing polybutadiene latex with large particle size based on a polymer agglomeration technology, belonging to the field of synthetic ABS resin. The traditional polymer agglomeration method uses the agglomeration agent which is acrylate and acrylic acid (or methacrylic acid, itaconic acid and the like) copolymer. The agglomeration agent is characterized in that a large amount of adsorptive emulsifying agent such as sodium dodecyl sulfate and the like is used in the polymerization process, so that the agglomeration agent can influence the graft polymerization and flocculation processes for preparing polybutadiene latex with large particle size, secondary nucleation and emulsifying agent residue are easily caused, and the quality of the final ABS resin is influenced. The invention adopts vinyl sulfate or vinyl sulfonate as a reactive emulsifier and an ionic comonomer to replace the traditional acrylic comonomer, does not use any adsorptive emulsifier in the process of preparing an agglomerant, has good agglomeration effect with polyacrylic emulsion copolymerized by the reactive emulsifier, and can prepare the narrow-distribution polybutadiene latex within the range of about 300nm to 500 nm.)

1. A method for preparing polybutadiene latex with large particle size based on a polymer agglomeration technology is characterized by comprising the following specific preparation steps:

(1) placing 1-20 parts of reactive emulsifier and 0.1-3 parts of electrolyte into a reaction kettle, adding 30-80 parts of deionized water into the reaction kettle, and stirring to completely dissolve the added reactive emulsifier and electrolyte into the deionized water; then adding 10-30 parts of monomer into the reaction kettle, replacing air in the reaction kettle with nitrogen for 2-3 times, starting stirring and heating the reaction kettle at a stirring speed of 20-400 rpm to 55-80 ℃; adding 1-5 parts of initiator aqueous solution into a reaction kettle, and starting to perform polymerization reaction;

(2) after the polymerization reaction in the step (1) is carried out for 0.5-2 hours, beginning to dropwise add 10-30 parts of monomer into the reaction kettle, wherein 0.001-1 part of chain transfer agent dodecyl mercaptan, 1-15 parts of reactive emulsifier and 1-5 parts of initiator aqueous solution are mixed in the monomer; the dripping time is controlled to be 1-6 hours; after the dropwise addition, heating the reaction kettle to 85-95 ℃, and preserving heat for 0.5-2 hours to fully react to obtain the polymer agglomerant latex;

(3) and (3) adjusting the polymer agglomerating agent latex obtained in the step (2) to 5-40% of solid content by using deionized water, and then adding 0.1-5 parts of the polymer agglomerating agent latex into 100 parts of butadiene latex to be agglomerated at the temperature of 40-70 ℃, wherein the adding mode is one-time adding, batch adding or dropwise adding, and agglomerating for 0.5-3 hours to obtain the large-particle-size polybutadiene latex.

2. The method according to claim 1, wherein the reactive emulsifier used in steps (1) and (2) is one or more selected from acrylamide sulfate, acrylamide sulfonate, vinyl sulfate, vinyl sulfonate, propyl sulfate, and allyl sulfonate.

3. The method according to claim 2, wherein the reactive emulsifier used in steps (1) and (2) is one or more selected from sodium acrylamido isopropyl sulfonate, sodium vinyl sulfonate, sodium allyl ether hydroxypropane sulfonate, allyl polyether sulfate, alkyl phenol allyl polyether sulfate, and allyl alcohol ether sulfate.

4. The method according to claim 1, wherein the electrolyte used in step (1) is one or more of potassium carbonate, sodium carbonate, potassium bicarbonate, sodium chloride and ammonium chloride.

5. The method of claim 4, wherein the electrolyte used in step (1) is potassium carbonate or sodium carbonate.

6. The method according to claim 1, wherein the monomer used in steps (1) and (2) is one or more of butyl acrylate, isooctyl acrylate, butyl methacrylate, styrene and acrylonitrile.

7. The method according to claim 1, characterized in that the initiator used in step (1) is one or more of potassium persulfate, ammonium persulfate, sodium persulfate and azoamidine hydrochloride.

8. The process according to claim 1, wherein the polymer agglomerant latex obtained in step (2) is adjusted to 30% solids content with deionized water.

Technical Field

The invention belongs to the field of synthetic resin, and particularly relates to a method for preparing polybutadiene latex with large particle size based on a polymer agglomeration technology.

Background

ABS resin is an engineering plastic with good mechanical property, solvent resistance and processability, and is generally prepared by an emulsion blending method, and the preparation of polybutadiene latex with large particle size is the most central technology in the preparation process. In general, the preparation process of the large-particle size polybutadiene latex can be divided into a one-step process and a two-step process. The one-step method is characterized in that butadiene and various auxiliary agents are fed at one time through an intermittent emulsion polymerization technology and polymerized for about 30 hours at the temperature of 60-85 ℃ to directly prepare the polybutadiene latex with the particle size of more than 300nm, the one-step method for preparing the polybutadiene latex with the large particle size is simple in process, only one-step intermittent polymerization is needed, and the solid content of the product reaches more than 55%. However, the one-step method for preparing polybutadiene latex with large particle size has the disadvantages of long polymerization period, low monomer conversion rate (generally only up to about 90 percent), and long subsequent treatment process. In order to overcome the defects of the one-step method, a process route for preparing polybutadiene latex by a two-step method is gradually proposed and increasingly improved, and large-scale industrial production is realized by a plurality of production devices at home and abroad at present.

The most common method for preparing the large-particle-size polybutadiene latex by the two-step method is an acetic acid agglomeration method, such as the petroleum Daqingpetrochemical process route, wherein small-particle-size polybutadiene latex with the particle size of 100nm is prepared firstly, then low-concentration acetic acid is used for agglomerating the small-particle-size polybutadiene latex, alkali liquor is added to neutralize the acetic acid after the agglomeration until the particle size reaches about 300nm, and the agglomeration of the acetic acid is stopped. The process for preparing the large-particle-size latex by the pressure agglomeration method belongs to a two-step method, is developed by GE company in the first place, and is a preparation technology of the large-particle-size polybutadiene latex used in Tianjin Dagu chemical industry in China, the first step of the technology is to prepare the small-particle-size polybutadiene latex with the particle size of about 100nm, then the small-particle-size polybutadiene latex is put into a high-pressure homogenizer, emulsifier molecules on the surface of the small-particle-size polybutadiene latex are rearranged by utilizing high-pressure airflow, the stability of the small-particle-size polybutadiene latex is damaged, the small-particle-size polybutadiene latex is in a metastable state, the coalescence is promoted among the particles, and finally the large-particle-size polybutadiene latex particles are prepared. How to develop a production process of polybutadiene latex with large particle size, high production efficiency, low cost and high toughening efficiency of the prepared polybutadiene latex is a problem which is urgently needed to be solved by ABS resin production enterprises.

The polymer agglomeration technology is a technology which is receiving attention from the ABS industry in recent years, and has been reported in partial patents and documents, and Taiwan Qimei company also applies the polymer agglomeration technology to industrial actual production. Patent CN104327281A discloses a preparation method of polybutadiene latex with monomodal distribution, which uses a polymer agglomerant to agglomerate the latex with the particle size of about 100nm directly into large-particle-size polybutadiene latex at the temperature of 40-50 ℃. The CN1730505A patent discloses a preparation method of a polymer agglomerating agent and an agglomeration process of polybutadiene latex by using the polymer agglomerating agent, wherein the polymer agglomerating agent used in the patent is an acrylate emulsion microsphere agglomerating agent containing carboxyl prepared by using butyl acrylate and acrylic acid as monomers through an emulsion polymerization method, and the particle size of the polybutadiene latex with large particle size after being agglomerated by using the agglomerating agent is up to 300-700 nm. CN102050889A discloses a method for preparing polybutadiene latex with super large particle size, wherein the polymer agglomerant is prepared by emulsion polymerization by using butyl acrylate, styrene and acrylic acid or methacrylic acid as comonomers. The agglomerant can agglomerate polybutadiene latex with large particle size (260-340 nm) into polybutadiene latex with extra large particle size of 400-1000 nm. CN109517286A discloses ABS resin and a preparation method thereof, wherein a polymer agglomerating agent is adopted to agglomerate a pentandine latex to prepare the large-particle-size pentandine latex, and the impact strength of the prepared ABS resin is 300J/m. Summarizing the polymer agglomeration agents used in the polymer agglomeration methods reported at present are all acrylate agglomeration agents, the preparation method is a random copolymer of acrylate and acrylic acid or methacrylic acid, and the polymer agglomeration agents are characterized by simpler preparation process and lower glass transition temperature of acrylate (usually butyl acrylate). However, the disadvantage of the butyl acrylate polymer agglomerant is that a large amount of adsorptive surfactants such as anionic surfactants such as sodium dodecyl sulfate, dodecyl benzene sulfonate and the like, and nonionic surfactants such as OP-10 and the like are adopted in the synthesis process of the agglomerant, and the emulsifiers are directly introduced into a polybutadiene latex system in the agglomeration process, so that the polybutadiene latex system is complicated, and the emulsifiers such as alkyl sulfate or alkyl sulfonate are added on the basis of the original disproportionated potassium rosinate, potassium fatty acid and potassium oleate. Because the acid resistance stability of the alkyl sulfonate or the sulfate is strong, and the critical micelle concentration of the emulsifier molecules is low, the secondary nucleation of the emulsion is easily induced in the emulsion graft polymerization stage at the later stage of the preparation of the latex with large particle size, and the latex particles with small particle size are generated. And the subsequent flocculation drying process is influenced, so that the consumption of a flocculating agent (sulfuric acid) is obviously increased, the impurity content in the prepared ABS resin is also increased, the phenomena of 'pocking marks' and the like are easy to occur in the preparation of large-area plate products, and the self glossiness and the attractiveness of the resin are influenced.

Therefore, the preparation of large-or ultra-large-particle polybutadiene latex by agglomerating polybutadiene latex using a novel polymer agglomerating agent is very important for the development of the technology. The invention adopts reactive emulsifier (such as vinyl sulfonate, vinyl sulfate and the like) as the emulsifier of the polymer agglomerant, and the emulsifier has stronger hydrophilicity and can be directly copolymerized into a molecular chain as a functional monomer, so that the hydrophilicity and the ductility of the molecular chain can be obviously improved, the emulsifier can be used for replacing monomers of agglomerants such as acrylic acid, methacrylic acid and the like, and the reactive emulsifier belongs to strong base and weak acid salt, so that the system is a weak alkaline system and is easy to match with polybutadiene latex, the stability of the latex system after the agglomeration process and the agglomeration are improved, the gel precipitation amount is less, the system has no adsorptive small molecular emulsifier, the subsequent graft polymerization reaction is not influenced, and the appearance performance and the mechanical strength of the ABS resin are improved.

Disclosure of Invention

The invention relates to a method for preparing polybutadiene latex with large particle size based on a polymer agglomeration technology, which comprises the following specific preparation steps:

(1) placing 1-20 parts of reactive emulsifier and 0.1-3 parts of electrolyte into a reaction kettle, adding 30-80 parts of deionized water into the reaction kettle, and stirring to completely dissolve the added reactive emulsifier and electrolyte into the deionized water; then adding 10-30 parts of monomer into the reaction kettle, replacing air in the reaction kettle with nitrogen for 2-3 times, starting stirring and heating the reaction kettle at a stirring speed of 20-400 rpm to 55-80 ℃; adding 1-5 parts of initiator aqueous solution into a reaction kettle, and starting to perform polymerization reaction;

(2) after the polymerization reaction in the step (1) is carried out for 0.5-2 hours, beginning to dropwise add 10-30 parts of monomer into the reaction kettle, wherein 0.001-1 part of chain transfer agent dodecyl mercaptan, 1-15 parts of reactive emulsifier and 1-5 parts of initiator aqueous solution are mixed in the monomer; the dripping time is controlled to be 1-6 hours; after the dropwise addition, heating the reaction kettle to 85-95 ℃, and preserving heat for 0.5-2 hours to fully react to obtain the polymer agglomerant latex;

(3) and (3) adjusting the polymer agglomerating agent latex obtained in the step (2) to 5-40% of solid content by using deionized water, and then adding 0.1-5 parts of the polymer agglomerating agent latex into 100 parts of butadiene latex to be agglomerated at the temperature of 40-70 ℃, wherein the adding mode is one-time adding, batch adding or dropwise adding, and agglomerating for 0.5-3 hours to obtain the large-particle-size polybutadiene latex.

The reactive emulsifier used in the steps (1) and (2) is acrylamide sulfate or acrylamide sulfonate or vinyl sulfate or vinyl sulfonate or allyl sulfate or allyl sulfonate, and specifically is one or a mixture of more of acrylamide isopropyl sodium sulfonate, vinyl sodium sulfonate, allyl ether hydroxyl propane sodium sulfonate, allyl polyether sulfate (trade mark V-10S), alkylphenol allyl propyl polyether sulfate (trade mark V-20S) and allyl alcohol ether sulfate (trade mark NRS-10).

The electrolyte used in step (1) of the invention is one or a mixture of more of potassium carbonate, sodium carbonate, potassium bicarbonate, sodium chloride and ammonium chloride, preferably potassium carbonate and sodium carbonate.

The monomer used in the steps (1) and (2) is one or a mixture of butyl acrylate, isooctyl acrylate, butyl methacrylate, styrene and acrylonitrile.

The initiator used in the step (1) in the invention is one or a mixture of potassium persulfate, ammonium persulfate, sodium persulfate and azoamidine hydrochloride (trade mark V50).

Preferably, the polymer agglomerant latex obtained in step (2) is adjusted to 30% solids content with deionized water.

The invention is characterized in that a sulfonate or sulfate type reactive emulsifier containing double bonds is used to prepare a polymer agglomerating agent, and the polymer agglomerating agent is used to agglomerate commercial grade polybutadiene latex.

Drawings

FIG. 1: the particle size distribution diagram of the small-particle-size polybutadiene latex to be agglomerated;

FIG. 2: example 1 polybutadiene latex particle size distribution plot after agglomeration;

FIG. 3: example 2 polybutadiene latex particle size distribution plot after agglomeration;

FIG. 4: example 3 polybutadiene latex particle size distribution plot after agglomeration;

FIG. 5: comparative example 1 particle size distribution plot of agglomerated polybutadiene latex;

FIG. 6: comparative example 2 particle size distribution plot of agglomerated polybutadiene latex;

the following examples and comparative examples are intended to understand the specific application of the present invention, but do not limit the scope of the present invention.

Detailed Description

Example 1

(1) 3 parts of acrylamide isopropyl sodium sulfonate as a reactive emulsifier, 2 parts of sodium vinylsulfonate, 0.4 part of electrolyte potassium carbonate and 0.1 part of sodium carbonate are placed in a reaction kettle, and 50 parts of deionized water is added into the reaction kettle and stirred so that the added reactive emulsifier and the electrolyte are completely dissolved in the deionized water. Then 10 parts of monomer butyl acrylate is added into the reaction kettle, nitrogen is used for replacing air in the reaction kettle for 2 times, then the reaction kettle starts stirring and is heated up, the stirring speed is 400rpm, and the temperature is raised to 55 ℃.2 parts of a 10% strength aqueous solution of potassium persulfate as an initiator was added to the reaction system to start the polymerization reaction.

(2) After the polymerization reaction in the step (1) is carried out for 0.5 hour, 20 parts of monomer butyl acrylate (mixed with 0.1 part of chain transfer agent dodecyl mercaptan), 10 parts of reactive emulsifier allyl ether sodium hydroxy propane sulfonate and 2.5 parts of initiator potassium persulfate aqueous solution are dripped into the reaction kettle. The dropping time was controlled to 6 hours. After the dropwise addition, the temperature of the reaction kettle is raised to 85 ℃, and the temperature is kept for 2 hours, so that the polymer agglomerant latex is obtained after full reaction.

(3) Adjusting the polymer agglomerating agent latex obtained in the step (2) to have a solid content of 30% by using deionized water, adding 2 parts of the diluted polymer agglomerating agent into 100 parts of polybutadiene latex to be agglomerated (the latex to be agglomerated is provided by Shanghai chemical technology Co., Ltd., the solid content is 40%, the average particle size is 103nm, the emulsifying system is a disproportionated rosin system, the particle size distribution diagram is shown in figure 1), and after 0.5 hour of agglomeration at 40 ℃, obtaining the large-particle-size polybutadiene latex, and testing the obtained large-particle-size polybutadiene latex by using a British Malvern laser particle sizer (ZS-90), wherein the particle size is 302nm, and the PDI value is 0.076, and is shown in figure 2.

Example 2

(1) 5 parts of allyl alcohol ether sulfate serving as a reactive emulsifier, 2 parts of potassium bicarbonate serving as an electrolyte and 1 part of sodium bicarbonate are placed in a reaction kettle, 50 parts of deionized water is added into the reaction kettle, and stirring is carried out to ensure that the added reactive emulsifier and the electrolyte are completely dissolved in the deionized water. Then 25 parts of monomer butyl acrylate and 5 parts of styrene are added into the reaction kettle, air in the reaction kettle is replaced by nitrogen for 3 times, then the reaction kettle starts stirring and is heated up, the stirring speed is 200rpm, and the temperature is raised to 60 ℃.2 parts of an aqueous ammonia persulfate solution as an initiator having a concentration of 10% was added to the reaction system to start the polymerization reaction.

(2) After the polymerization reaction in the step (1) is carried out for 0.5 hour, 10 parts of monomer butyl acrylate, 10 parts of isooctyl acrylate (mixed with 0.01 part of chain transfer agent dodecyl mercaptan), 10 parts of reactive emulsifier alkylphenol allyl polyether sulfate and 2 parts of initiator sodium persulfate aqueous solution are dripped into the reaction kettle. The dropping time was controlled to 4 hours. After the dropwise addition, the temperature of the reaction kettle is raised to 95 ℃, and the temperature is kept for 1 hour, so that the polymer agglomerant latex is obtained after full reaction.

(3) Adjusting the polymer agglomerating agent latex obtained in the step (2) to have a solid content of 30% by using deionized water, adding 3 parts of the diluted polymer agglomerating agent into 100 parts of polybutadiene latex to be agglomerated (the latex to be agglomerated is provided by Shanghai chemical technology Co., Ltd., the solid content is 40%, the average particle size is 103nm, the emulsifying system is a disproportionated rosin system, the particle size distribution diagram is shown in figure 1), and after 0.5 hour of agglomeration at 40 ℃, obtaining the large-particle-size polybutadiene latex, and testing the obtained large-particle-size polybutadiene latex by using a British Malvern laser particle sizer (ZS-90), wherein the particle size is 425nm, and the PDI value is 0.053, and is shown in figure 3.

Example 3

(1) 20 parts of reactive emulsifier allyl polyether sulfate (trade mark NRS-10), 0.1 part of electrolyte potassium bicarbonate and 0.1 part of sodium bicarbonate are placed in a reaction kettle, and 50 parts of deionized water is added into the reaction kettle and stirred to ensure that the added reactive emulsifier and the electrolyte are completely dissolved in the deionized water. Then 5 parts of monomer butyl acrylate and 5 parts of isooctyl acrylate are added into the reaction kettle, the air in the reaction kettle is replaced by nitrogen for 2 times, then the reaction kettle starts stirring and is heated up, the stirring speed is 200rpm, and the temperature is raised to 65 ℃.2 parts of a 10% aqueous solution of initiator sodium persulfate was added to the reaction system to start the polymerization reaction.

(2) After the polymerization reaction in the step (1) is carried out for 0.5 hour, 5 parts of monomer butyl acrylate, 5 parts of isooctyl acrylate (mixed with 0.01 part of chain transfer agent dodecyl mercaptan), 10 parts of reactive emulsifier alkylphenol allyl polyether sulfate and 2 parts of initiator sodium persulfate aqueous solution are dripped into the reaction kettle. The dropping time was controlled to 4 hours. After the dropwise addition, the temperature of the reaction kettle is raised to 95 ℃, and the temperature is kept for 1 hour, so that the polymer agglomerant latex is obtained after full reaction.

(3) Adjusting the polymer agglomerating agent latex obtained in the step (2) to have a solid content of 30% by using deionized water, dropwise adding 5 parts of the diluted polymer agglomerating agent into 100 parts of polybutadiene latex to be agglomerated (the latex to be agglomerated is provided by Shanghai chemical technology Co., Ltd., the solid content is 40%, the average particle size is 103nm, the emulsifying system is a disproportionated rosin system, the particle size distribution diagram is shown in figure 1), the dropwise adding time is 0.5 hour, and after 0.5 hour of agglomeration at 60 ℃, the large-particle-size polybutadiene latex can be obtained, and the obtained large-particle-size latex is tested by a laser particle sizer (ZS-90) of British Malvern company, wherein the particle size is 513nm, and the PDI value is 0.051, and is shown in figure 4.

Comparative example 1

(1) 3 parts of adsorption type emulsifier sodium dodecyl sulfate, 0.4 part of electrolyte potassium carbonate and 0.1 part of sodium carbonate are placed in a reaction kettle, 50 parts of deionized water is added into the reaction kettle, and stirring is carried out, so that the added adsorption type emulsifier and electrolyte are completely dissolved in the deionized water. Then 10 parts of monomer butyl acrylate is added into the reaction kettle, nitrogen is used for replacing air in the reaction kettle for 2 times, then the reaction kettle starts stirring and is heated up, the stirring speed is 400rpm, and the temperature is raised to 55 ℃.2 parts of a 10% strength aqueous solution of potassium persulfate as an initiator was added to the reaction system to start the polymerization reaction.

(2) After the polymerization reaction in the step (1) is carried out for 0.5 hour, 20 parts of monomer butyl acrylate (mixed with 0.1 part of chain transfer agent dodecyl mercaptan), 10 parts of adsorption type emulsifier sodium dodecyl sulfate (aqueous solution with the concentration of 2%) and 2.5 parts of initiator potassium persulfate aqueous solution are dripped into the reaction kettle. The dropping time was controlled to 6 hours. After the dropwise addition, the temperature of the reaction kettle is raised to 85 ℃, and the temperature is kept for 2 hours, so that the polymer agglomerant latex is obtained after full reaction.

(3) Adjusting the polymer agglomerating agent latex obtained in the step (2) to have a solid content of 30% by using deionized water, adding 2 parts of the diluted polymer agglomerating agent into 100 parts of polybutadiene latex to be agglomerated (the latex to be agglomerated is provided by Shanghai chemical technology Co., Ltd., the solid content is 40%, the average particle size is 103nm, the emulsifying system is a disproportionated rosin system, the particle size distribution diagram is shown in figure 1), and after 0.5 hour of agglomeration at 40 ℃, obtaining the large-particle-size polybutadiene latex, and testing the obtained large-particle-size polybutadiene latex by using a British Malvern laser particle sizer (ZS-90), wherein the particle size is 109nm, and the PDI value is 0.083, and is shown in figure 5. This shows that there is no agglomeration effect in the acrylic ester emulsion to which only the adsorption type emulsifier is added, and it cannot be used as a polymer agglomerating agent.

Comparative example 2

(1) 2 parts of adsorption type emulsifier sodium dodecyl sulfate, 1 part of ionic emulsifier isotridecanol polyoxyethylene ether (T-8), 0.4 part of electrolyte potassium carbonate and 0.2 part of sodium carbonate are placed in a reaction kettle, and 50 parts of deionized water is added into the reaction kettle and stirred to ensure that the added adsorption type emulsifier and electrolyte are completely dissolved in the deionized water. Then 10 parts of monomer butyl acrylate is added into the reaction kettle, nitrogen is used for replacing air in the reaction kettle for 2 times, then the reaction kettle starts stirring and is heated up, the stirring speed is 400rpm, and the temperature is raised to 55 ℃.2 parts of a 10% strength aqueous solution of potassium persulfate as an initiator was added to the reaction system to start the polymerization reaction.

(2) After the polymerization reaction in the step (1) is carried out for 0.5 hour, 20 parts of monomer butyl acrylate (mixed with 0.1 part of chain transfer agent dodecyl mercaptan), 10 parts of adsorption emulsifier sodium dodecyl sulfate (aqueous solution with the concentration of 2%), 1 part of isotridecanol polyoxyethylene ether (T-8) and 2.5 parts of initiator potassium persulfate aqueous solution are dripped into the reaction kettle. The dropping time was controlled to 6 hours. After the dropwise addition, the temperature of the reaction kettle is raised to 85 ℃, and the temperature is kept for 2 hours, so that the polymer agglomerant latex is obtained after full reaction.

(3) Adjusting the polymer agglomerating agent latex obtained in the step (2) to have a solid content of 30% by using deionized water, adding 2 parts of the diluted polymer agglomerating agent into 100 parts of polybutadiene latex to be agglomerated (the latex to be agglomerated is provided by Shanghai chemical technology Co., Ltd., the solid content is 40%, the average particle size is 103nm, the emulsifying system is a disproportionated rosin system, the particle size distribution diagram is shown in the figure 1), and after 0.5 hour of agglomeration at 40 ℃, obtaining the large-particle-size polybutadiene latex, and testing the obtained large-particle-size polybutadiene latex by using a British Malwinia laser particle sizer (ZS-90), wherein the particle size is 106nm, and the PDI value is 0.072, and is shown in the figure 6. This shows that the acrylic ester emulsion containing only the adsorption-type emulsifier still has no agglomeration effect and cannot be used as a polymer agglomerating agent.

The above-described embodiments should not be construed as limiting the scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.