Bio-based acrylate emulsion having zero SVOC emissions and preparation method therefor

Abstract

The present invention relates to a bio-based acrylate emulsion having zero SVOC emissions. The bio-based acrylate emulsion comprises, by mass percentage, 4% to 15% of an acrylate monomer, 1% to 15% of an ethylene monomer, 12% to 41% of a bio-based acrylate monomer, 0.2% to 2% of a bio-based carboxyl monomer, 0.5% to 3% of other specialty monomers, 1% to 3% of an emulsifier, 0.15% to 3% of an initiator, 40% to 60% of deionized water, 0.1% to 5% of a pH stabilizer, 0.05% to 1% of a post-treatment agent, and 0.05% to 1% of a functional auxiliary. The sum of the mass percentages of the described components is 100%. The bio-based acrylate emulsion having zero SVOC emissions does not contain low-boiling organic substances such as a film-forming aid and an antifreeze agent, and can exhibit low-temperature freeze-thaw cycle stability while maintaining excellent scrub resistance and thick coating crack resistance. The present invention further comprises a method for preparing the bio-based acrylate emulsion having zero SVOC emissions.

Description

A bio-based acrylate emulsion with zero SVOC emissions and its preparation method Technical Field

[0001] This invention relates to the field of architectural coatings, and more specifically to a bio-based acrylic emulsion with zero SVOC emissions for interior wall coatings, and a method for preparing the acrylic emulsion. Background Technology

[0002] With increasing global emphasis on environmental protection and sustainable development, the building materials industry is constantly exploring and developing more environmentally friendly and healthier products. Among these, interior wall coatings, due to their wide application, have gradually become a key area of ​​industry research. Traditional building coatings often contain large amounts of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). These substances are released into the air during the coating drying process, causing adverse effects on human health and the environment.

[0003] In order to achieve better coating film and antifreeze properties, commonly used acrylic emulsions in existing technologies often contain a certain amount of VOCs and SVOCs, such as film-forming aids, solvents, plasticizers, and other additives, making it impossible to achieve zero SVOC emissions. Without the addition of film-forming aids, the resulting coating is prone to cracking and cannot form an effective film. Therefore, acrylic emulsions with zero SVOC emissions need to possess certain film-forming aid properties.

[0004] Bio-based materials are extracted from renewable resources (such as plants and microorganisms), and compared to traditional petroleum-based materials, they have a lower carbon footprint and higher sustainability. Typically, bio-based emulsions can be achieved using bio-based monomers. However, bio-based monomers suffer from problems such as large steric hindrance, low reactivity, and significant electronic effects, leading to a series of challenges including low polymerization conversion rates, poor storage stability, sticky coatings, and poor application performance after paint formulation.

[0005] In view of this, there is an urgent need in the field to develop a bio-based acrylate emulsion with zero SVOC emissions, which can overcome the problems of bio-based monomers while adding no film-forming aids, and maintain excellent scrub resistance and thick coating crack resistance while having low-temperature freeze-thaw cycle stability, so as to solve the problems existing in the prior art. Summary of the Invention

[0006] Based on the above facts, the purpose of this invention is to provide a zero-SVOC emission bio-based acrylate emulsion, which solves the polymerization stability problem caused by bio-based monomers by optimizing monomer ratios, selecting preferred emulsifiers, and improving the production process. Simultaneously, this zero-SVOC emission bio-based acrylate emulsion does not contain low-boiling organic compounds such as film-forming aids and antifreeze agents. Through a core-shell polymerization process, it improves low-temperature film-forming performance and scrub resistance, maintaining excellent scrub resistance and thick-coat cracking resistance while exhibiting low-temperature freeze-thaw cycle stability.

[0007] A first aspect of the present invention provides a zero-SVOC bio-based acrylate emulsion, comprising, by weight percentage:

[0008] The total mass percentage of all the above components is 100%.

[0009] acrylate monomers

[0010] In some embodiments of the present invention, the acrylate monomer is selected from one or more of the following: methyl methacrylate, sec-butyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, hexadecyl methacrylate, coconut oleate methacrylate, octadecyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, isobornyl methacrylate, dimethylaminopropyl methacrylate, glycidyl methacrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and trimethylolpropane tri(meth)acrylate.

[0011] Ethylene monomers

[0012] In some embodiments of the present invention, the ethylene monomer is selected from at least one of styrene, vinyl acetate, dichloroethylene, acrylonitrile, (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-hydroxymethyl(meth)acrylamide, and divinylbenzene.

[0013] In some preferred embodiments of the present invention, the ethylene monomers are styrene and acrylamide, and more preferably, the mass ratio of styrene to acrylamide is (5-30):1.

[0014] Bio-based acrylate monomers

[0015] In this invention, the bio-based acrylate monomer is a long-chain polymerizable monomer containing unsaturated olefins, prepared through bio-fermentation, chemical degradation, or chemical conversion.

[0016] In some embodiments of the present invention, the bio-based acrylate monomer is selected from one or more of bio-based ethyl (meth)acrylate, bio-based n-butyl (meth)acrylate, bio-based isobutyl (meth)acrylate, bio-based dodecyl (meth)acrylate, bio-based octadecyl (meth)acrylate, and bio-based isobornyl (meth)acrylate.

[0017] Bio-based carboxyl monomers

[0018] In some preferred embodiments of the present invention, the bio-based carboxyl monomer is itaconic acid. Itaconic acid is mainly produced by fermentation, using agricultural by-products as raw materials and fermented with microorganisms. Common raw materials include renewable resources such as corn starch and glucose, all of which fall under the category of biomass and are consistent with the characteristic of bio-based products using renewable biomass as raw materials.

[0019] Other special monomers

[0020] In this invention, the other special monomers are selected from one or more of other special acrylate monomers and olefinic phosphate functional monomers. Their main purpose is to provide polymers with some special properties, such as improving the scrub resistance and waterproof performance of coatings.

[0021] In some embodiments of the present invention, the other special acrylate monomers are selected from one or more of 3-(methacryloyloxy)propyltrimethoxysilane, ethyl urea methacrylate, glycidyl methacrylate, butanediol diacrylate, allyl methacrylate, and ethyl acetoacetate; the olefinic phosphate functional monomers are selected from one or more of Solvay's SIPOMER PAM-100, SIPOMER PAM-200, and SIPOMER PAM-4000.

[0022] The other special monomers preferably include at least olefinic phosphate esters and ethyl acetoacetate methacrylate, with a preferred mass ratio of 1:(5-10), for example 1:5, 1:8, or 1:9; more preferably, the other special monomers are composed of olefinic phosphate esters, ethylidene methacrylate ethoxylate, and ethyl acetoacetate methacrylate in a mass ratio of 1:(1-2):(5-10).

[0023] emulsifier

[0024] In this invention, the emulsifier is selected from one or more of anionic emulsifiers and nonionic emulsifiers.

[0025] In some preferred embodiments of the present invention, the emulsifier contains both anionic and nonionic emulsifiers, wherein the mass ratio of the anionic emulsifier to the nonionic emulsifier is any ratio between (1-7):(1-3). More preferably, the anionic emulsifier is selected from one or more of alkyl polyoxyethylene ether succinate monoester sulfonate disodium, alkyl polyoxyethylene ether sulfate sodium, block copolymer phosphate ester sodium salt, aryl polyoxyethylene ether sulfate sodium, dodecyl sulfate sodium, dodecylbenzene sulfonate sodium, and dodecyl diphenyl ether disulfonate sodium; the nonionic emulsifier is selected from one or more of alkyl polyoxyethylene ether, polyaryl polyoxyethylene ether, and block polyether.

[0026] Initiator

[0027] In some embodiments of the present invention, the initiator is selected from one or more of sodium persulfate, potassium persulfate, and ammonium persulfate.

[0028] pH stabilizer

[0029] In some embodiments of the present invention, the pH stabilizer is selected from one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, and potassium carbonate.

[0030] Post-treatment agent

[0031] In some embodiments of the present invention, the post-treatment agent consists of an oxidant and a reducing agent, wherein the mass ratio of the oxidant to the reducing agent is any ratio between 1:(1-2). Preferably, the oxidant is selected from one or a combination of tert-butyl hydroperoxide and hydrogen peroxide, and the reducing agent is selected from one or more of sodium isoascorbate, sodium bisulfite, sodium metabisulfite, Bruggolite FF6M, and Bruggolite TP1646.

[0032] Functional additives

[0033] In some embodiments of the present invention, the functional additive is selected from one or more of antifreeze agents, defoamers, and bactericides that meet the zero SVOC requirement.

[0034] Specifically, the antifreeze is selected from one or more of Clariant Genapol X 1005, Aslan Strodex FT-68, Strodex FT-88, and Solvay Rhodoline FT-100.

[0035] A second aspect of the present invention provides a method for preparing the zero SVOC emission bio-based acrylate emulsion described in the first aspect of the present invention, comprising the following steps:

[0036] S1: Preparation of bottom liquid: Mix 30%-40% deionized water and 0.1%-1% emulsifier, and heat to 80-90℃ to obtain bottom liquid;

[0037] S2: Preparation of pre-emulsion: 5%-10% deionized water, 0.4%-2.4% emulsifier, 1%-15% ethylene monomer, 4%-15% acrylate monomer, and 0.2%-2% bio-based carboxyl monomer are stirred until uniformly dispersed to obtain a core layer pre-emulsion; 1%-3% deionized water, 0.5%-1% emulsifier, 12%-41% bio-based acrylate monomer, and 0.5%-3% other special monomers are stirred until uniformly dispersed to obtain a shell layer pre-emulsion.

[0038] S3: Preparation of initiator solution: Mix 0.1%-0.5% initiator with 3%-5% deionized water to obtain initiator solution;

[0039] S4: Preparation of seed emulsion: Keep the temperature at 80-95℃, add 1%-10% by mass of core layer pre-emulsion and 10%-60% by mass of initiator solution to the bottom liquid of the reactor, mix and react. When the emulsion with a bluish glow appears in the reactor, keep the temperature constant for 20 minutes to obtain the seed emulsion.

[0040] S5: Preparation of core layer emulsion: Keep the temperature at 80-95℃, add the remaining core layer pre-emulsion and 2 / 3 of the remaining initiator solution to the seed emulsion, and control the total time for adding the core layer pre-emulsion and initiator solution to 120min. After the addition is completed, keep the temperature constant for 30min to obtain the core layer emulsion.

[0041] S6: Core-shell polymerization: Keep the temperature at 80-95℃, add shell pre-emulsion and remaining initiator solution dropwise to the core layer emulsion, control the total time for adding shell pre-emulsion and remaining initiator solution to 60min, and keep the temperature constant for 60min after the addition is completed to form an acrylic emulsion system;

[0042] S7: Post-treatment and tailings addition: Maintain the temperature at 50-70℃, add 0.05%-2.5% initiator dropwise to the acrylic emulsion system, keep warm for 30-60 minutes, then cool down to 15-45℃, add 0.05%-1% post-treatment agent and 0.05%-1% functional additives, adjust the pH to 7.0-9.0 with 0.1%-5% pH stabilizer, and filter to obtain the zero SVOC emission bio-based acrylic emulsion.

[0043] A third aspect of the present invention provides another method for preparing the zero SVOC emission bio-based acrylate emulsion described in the first aspect of the present invention, comprising the following steps:

[0044] S1: Preparation of bottom liquid: Mix 30%-40% deionized water and 0.1%-1% emulsifier, and heat to 80-90℃ to obtain bottom liquid;

[0045] S2: Preparation of pre-emulsion: 5%-10% deionized water, 0.4%-2.4% emulsifier, 1%-15% ethylene monomer, 12%-41% bio-based acrylate monomer, and 0.2%-2% bio-based carboxyl monomer are stirred until uniformly dispersed to obtain the core layer pre-emulsion; 1%-3% deionized water, 0.5%-1% emulsifier, 4%-15% acrylate monomer, and 0.5%-3% other special monomers are stirred until uniformly dispersed to obtain the shell layer pre-emulsion;

[0046] S3: Preparation of initiator solution: Mix 0.1%-0.5% initiator with 3%-5% deionized water to obtain initiator solution;

[0047] S4: Preparation of seed emulsion: Keep the temperature at 80-95℃, add 1%-10% by mass of core layer pre-emulsion and 10%-60% by mass of initiator solution to the bottom liquid of the reactor, mix and react. When the emulsion with a bluish glow appears in the reactor, keep the temperature constant for 20 minutes to obtain the seed emulsion.

[0048] S5: Preparation of core layer emulsion: Keep the temperature at 80-95℃, add the remaining core layer pre-emulsion and 2 / 3 of the remaining initiator solution to the seed emulsion, and control the total time for adding the core layer pre-emulsion and initiator solution to 120min. After the addition is completed, keep the temperature constant for 30min to obtain the core layer emulsion.

[0049] S6: Core-shell polymerization: Keep the temperature at 80-95℃, add shell pre-emulsion and remaining initiator solution dropwise to the core layer emulsion, control the total time for adding shell pre-emulsion and remaining initiator solution to 60min, and keep the temperature constant for 60min after the addition is completed to form an acrylic emulsion system;

[0050] S7: Post-treatment and tailings addition: Maintain the temperature at 50-70℃, add 0.05%-2.5% initiator dropwise to the acrylic emulsion system, keep warm for 30-60 minutes, then cool down to 15-45℃, add 0.05%-1% post-treatment agent and 0.05%-1% functional additives, adjust the pH to 7.0-9.0 with 0.1%-5% pH stabilizer, and filter to obtain the zero SVOC emission bio-based acrylic emulsion.

[0051] Beneficial effects of the present invention

[0052] This invention addresses the shortcomings of existing technologies by providing a zero-SVOC (Solid-Volatile Organic Compound) bio-based acrylate emulsion. By optimizing monomer ratios, selecting appropriate emulsifiers, and improving the production process, it solves the polymerization stability problem caused by bio-based monomers. Furthermore, this zero-SVOC bio-based acrylate emulsion is free of low-boiling organic compounds such as film-forming aids and antifreeze agents. Through a core-shell polymerization process, it improves low-temperature film-forming properties and scrub resistance, maintaining excellent scrub resistance and resistance to thick-coat cracking while exhibiting resistance to low-temperature freeze-thaw cycles. Moreover, when applied to interior wall coatings, only 15-20% by weight (approximately 48% emulsion solids) of this zero-SVOC bio-based acrylate emulsion is needed to give the interior wall coating high scrub resistance, high adhesion, and excellent resistance to thick-coat cracking. Detailed Implementation

[0053] To more clearly illustrate the present invention, specific embodiments are described below. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention. The technical concept of the present invention can be implemented in combination with other known technologies or other technologies with the same functions as those known technologies.

[0054] Examples 1-3 and Comparative Examples 1-3

[0055] Bio-based acrylate emulsions of Examples 1-3 and Comparative Examples 1-3 were prepared according to the formulations in Table 1. The bio-based n-butyl acrylate and bio-based ethyl acrylate used were bio-based products from Suzhou Hechuang Chemical Co., Ltd. The preparation steps are as follows:

[0056] S1: Preparation of bottom liquid: Mix 30%-40% deionized water, 0.1%-1% anionic emulsifier and 0.05%-0.1% nonionic emulsifier, and heat to 80-90℃ to obtain bottom liquid;

[0057] S2: Preparation of pre-emulsion: 5%-10% deionized water, 0.4%-2.4% anionic emulsifier, 0.05%-0.5% nonionic emulsifier, 1%-15% ethylene monomers, 12%-41% bio-based acrylate monomers, and 0.2%-2% bio-based carboxyl monomers are stirred until uniformly dispersed to obtain a core layer pre-emulsion; 1%-3% deionized water, 0.5%-1% anionic emulsifier, 4%-15% acrylate monomers, and 0.5%-3% other special monomers are stirred until uniformly dispersed to obtain a shell layer pre-emulsion;

[0058] S3: Preparation of initiator solution: Mix 0.1%-0.5% initiator with 3%-5% deionized water to obtain initiator solution;

[0059] S4: Preparation of seed emulsion: Keep the temperature at 80-95℃, add 10% by mass of core layer pre-emulsion and 20% by mass of initiator solution to the bottom liquid of the reactor, mix and react. When the emulsion with a bluish glow appears in the reactor, keep the temperature constant for 20 minutes to obtain the seed emulsion.

[0060] S5: Preparation of core layer emulsion: Keep the temperature at 80-95℃, add the remaining core layer pre-emulsion and 2 / 3 of the remaining initiator solution to the seed emulsion, and control the total time for adding the core layer pre-emulsion and initiator solution to 120min. After the addition is completed, keep the temperature constant for 30min to obtain the core layer emulsion.

[0061] S6: Core-shell polymerization: Keep the temperature at 80-95℃, add shell pre-emulsion and remaining initiator solution dropwise to the core layer emulsion, control the total time for adding shell pre-emulsion and remaining initiator solution to 60min, and keep the temperature constant for 60min after the addition is completed to form an acrylic emulsion system;

[0062] S7: Post-treatment and tailings addition: Maintain the temperature at 50-70℃, add 0.05%-2.5% initiator dropwise to the acrylic emulsion system, keep warm for 30-60 minutes, then cool down to 15-45℃, add 0.05%-1% post-treatment agent and 0.05%-1% functional additive, adjust the pH to 7.0-9.0 with 0.1%-2% pH adjuster, and after filtration, the zero SVOC emission bio-based acrylic emulsion is obtained.

[0063] The particle sizes of Examples 1-3 and Comparative Examples 1-3 prepared by the above method were 140 nm, 144 nm, 150 nm, 141 nm, 143 nm, and 153 nm, respectively, and the solid contents were 48.4%, 49.9%, 48.1%, 48.2%, 48.9%, and 47.7%, respectively.

[0064] Table 1. Formulation of zero SVOC emission bio-based acrylate emulsions in Examples 1-3 and Comparative Examples 1-3

[0065] It should be noted that Comparative Examples 1-3 are still within the scope of protection of this invention. The only difference between them and Examples 1-3 is the composition of other special monomers. Since Comparative Examples 1-3 did not select the preferred formulation described in this invention, they are inferior to Examples 1-3 in terms of scrub resistance, freeze-thaw stability, and low-temperature thick coating cracking, but they can still achieve the basic objective of the invention regarding bio-based zero SVOC.

[0066] The emulsions obtained in Examples 1-3 and Comparative Examples 1-3 were formulated into coatings according to the following process and formulation, and then their performance was evaluated.

[0067] Formulated as a coating:

[0068] The emulsions obtained in Examples 1-3 and Comparative Examples 1-3 were used in interior wall coatings. Except for the emulsions, all components of the coatings were selected from conventional coating preparation components, and the preparation method employed conventional coating preparation methods. By weight, the coatings comprised 18 parts of the corresponding emulsion, 80 parts of a conventional ordinary slurry without any SVOC-containing film-forming aids or antifreeze agents, and 2 parts of water.

[0069] The testing methods shall be carried out in accordance with the following standards:

[0070] Scrub resistance: As per GB / T 9756-2020, 5.5.11;

[0071] Freeze-thaw stability: Comply with 5.5.6 of GB / T 9756-2020;

[0072] Low-temperature thick coating cracking: Follow the Nippon Paint method, the main operating steps are as follows:

[0073] 1. Prepare two A4 general-purpose putty boards and two A4 loose putty boards;

[0074] 2. After performing simple dust removal treatment on each putty board, place it on an analytical balance;

[0075] 3. Using a damp wool brush, apply 40g of paint evenly to the putty board (for superior grade products, use ≥40g of paint; for first grade and below, use ≥30g of paint. This test adopts the test method for superior grade products).

[0076] 4. Place one A4 general-purpose putty board and one A4 loose putty board in a specified 25℃ environment to form a film. Place another A4 general-purpose putty board and another A4 loose putty board in a specified 5℃ environment to form a film. Observe the cracking of the paint film after 24 hours.

[0077] 5. Evaluation method: All putty boards placed at 25℃ and 5℃ are considered to have passed if there are no obvious cracks on the paint film surface.

[0078] The test results are shown in Table 2 below.

[0079] Table 2. Test results of coatings prepared in Examples 1-3 and Comparative Examples 1-3.

[0080] Note: Bio-based content percentage refers to the percentage of total emulsion content.

[0081] The semi-volatile organic compound (SVOC, g / L) content of the emulsions and coatings prepared in Examples 1-3 and Comparative Examples 1-3 was determined according to Appendix 11.4 of GB / T 23896.2-2023. The test results are shown in Table 3 below:

[0082] Table 3. Results of semi-volatile organic compound content detection in emulsions and coatings of Examples 1-3 and Comparative Examples 1-3.

[0083] Note: The detection limit for semi-volatile organic compounds (SVOC) is 0.01%.

[0084] As shown in Tables 2 and 3, the preparation process of this invention is simple and easy to operate. The prepared zero-SVOC emission bio-based acrylate emulsion has high polymerization stability, scrub resistance, thick coating crack resistance, and 6-cycle freeze-thaw stability, all of which meet the application requirements. No semi-volatile organic compounds were detected after it was formulated into a coating, so it can be used as a water-based bio-based SVOC-free interior wall coating for building.

[0085] Meanwhile, generally speaking, a resin content of 30 parts or more in interior wall coatings is required to achieve good scrub resistance, low-temperature thick coating crack resistance, and other properties. Although this invention uses only 18 parts of acrylic emulsion in the coating, the resulting coating still meets the application requirements for scrub resistance, thick coating crack resistance, and stability after 6 cycles of freeze-thaw cycles. This fully demonstrates that the method described in this invention can further improve the low-temperature film-forming performance of the resin.

[0086] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A bio-based acrylate emulsion with zero SVOC emissions, comprising, by mass percentage: The total mass percentage of all the above components is 100%.

2. The zero SVOC emission bio-based acrylate emulsion according to claim 1, characterized in that, The acrylate monomers are selected from methyl methacrylate, sec-butyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, hexadecyl methacrylate, coconut acrylate, octadecyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, isobornyl methacrylate, dimethylaminopropyl methacrylate, glycidyl methacrylate, and ethylene glycol di(methyl)propylene. The ethylene monomer is selected from one or more of styrene, vinyl acetate, dichloroethylene, acrylonitrile, (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, and divinylbenzene; preferably, the ethylene monomer is styrene and acrylamide, more preferably, the mass ratio of styrene to acrylamide is (5-30):

1.

3. The zero SVOC emission bio-based acrylate emulsion according to claim 1, characterized in that, The bio-based acrylate monomer is selected from one or more of the following: bio-based ethyl methacrylate, bio-based n-butyl methacrylate, bio-based isobutyl methacrylate, bio-based dodecyl methacrylate, bio-based octadecyl methacrylate, and bio-based isoborneol methacrylate.

4. The zero SVOC emission bio-based acrylate emulsion according to claim 1, characterized in that, The bio-based carboxyl monomer is itaconic acid.

5. The zero SVOC emission bio-based acrylate emulsion according to claim 1, characterized in that, The other special monomers are selected from one or more of other special acrylate monomers and olefinic phosphate functional monomers; preferably, the other special acrylate monomers are selected from one or more of 3-(methacryloyloxy)propyltrimethoxysilane, ethylene urea methacrylate, glycidyl methacrylate, butanediol diacrylate, allyl methacrylate, and ethyl acetoacetate methacrylate; the olefinic phosphate functional monomers are selected from one or more of Solvay's SIPOMER PAM-100, SIPOMER PAM-200, and SIPOMER PAM-4000; preferably, the other special monomers include at least olefinic phosphate and ethyl acetoacetate methacrylate, and the mass ratio of the olefinic phosphate to ethyl acetoacetate methacrylate is preferably 1:(5-10); more preferably, the other special monomers are composed of olefinic phosphate, ethylene urea methacrylate, and ethyl acetoacetate methacrylate in a mass ratio of 1:(1-2):(5-10).

6. The zero SVOC emission bio-based acrylate emulsion according to claim 1, characterized in that, The emulsifier is selected from one or more of anionic emulsifiers and nonionic emulsifiers; preferably, the emulsifier is selected from a combination of anionic emulsifiers and nonionic emulsifiers, and the mass ratio of the anionic emulsifier to the nonionic emulsifier is any ratio between (1-7):(1-3); more preferably, the anionic emulsifier is selected from one or more of alkyl polyoxyethylene ether succinate monoester disodium sulfonate, alkyl polyoxyethylene ether sodium sulfate, block copolymer phosphate sodium salt, aryl polyoxyethylene ether sodium sulfate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and sodium dodecyl diphenyl ether disulfonate, and the nonionic emulsifier is selected from one or more of alkyl polyoxyethylene ether, polyaryl polyoxyethylene ether, and block polyether.

7. The zero SVOC emission bio-based acrylate emulsion according to claim 1, characterized in that, The initiator is selected from one or more of sodium persulfate, potassium persulfate, and ammonium persulfate; the pH stabilizer is selected from one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, and potassium carbonate; and the functional additive is selected from one or more of antifreeze, defoamer, and bactericide.

8. The zero SVOC emission bio-based acrylate emulsion according to claim 1, characterized in that, The post-treatment agent consists of an oxidant and a reducing agent, wherein the mass ratio of the oxidant to the reducing agent is any ratio between 1 and (1-2); preferably, the oxidant is selected from one or a combination of tert-butyl hydrogen peroxide and hydrogen peroxide, and the reducing agent is selected from one or more of sodium isoascorbate, sodium bisulfite, sodium metabisulfite, Bruggolite FF6M, and Bruggolite TP1646.

9. A method for preparing a zero-SVOC emission bio-based acrylate emulsion as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Preparation of bottom liquid: Mix 30%-40% deionized water and 0.1%-1% emulsifier, and heat to 80-90℃ to obtain bottom liquid; S2: Preparation of pre-emulsion: 5%-10% deionized water, 0.4%-2.4% emulsifier, 1%-15% ethylene monomer, 4%-15% acrylate monomer, and 0.2%-2% bio-based carboxyl monomer are stirred until uniformly dispersed to obtain a core layer pre-emulsion; 1%-3% deionized water, 0.5%-1% emulsifier, 12%-41% bio-based acrylate monomer, and 0.5%-3% other special monomers are stirred until uniformly dispersed to obtain a shell layer pre-emulsion. S3: Preparation of initiator solution: Mix 0.1%-0.5% initiator with 3%-5% deionized water to obtain initiator solution; S4: Preparation of seed emulsion: Keep the temperature at 80-95℃, add 1%-10% by mass of core layer pre-emulsion and 10%-60% by mass of initiator solution to the bottom liquid of the reactor, mix and react. When the emulsion with a bluish glow appears in the reactor, keep the temperature constant for 20 minutes to obtain the seed emulsion. S5: Preparation of core layer emulsion: Keep the temperature at 80-95℃, add the remaining core layer pre-emulsion and 2 / 3 of the remaining initiator solution to the seed emulsion, and control the total time for adding the core layer pre-emulsion and initiator solution to 120min. After the addition is completed, keep the temperature constant for 30min to obtain the core layer emulsion. S6: Core-shell polymerization: Keep the temperature at 80-95℃, add shell pre-emulsion and remaining initiator solution dropwise to the core layer emulsion, control the total time for adding shell pre-emulsion and remaining initiator solution to 60min, and keep the temperature constant for 60min after the addition is completed to form an acrylic emulsion system; S7: Post-treatment and tailings addition: Maintain the temperature at 50-70℃, add 0.05%-2.5% initiator dropwise to the acrylic emulsion system, keep warm for 30-60 minutes, then cool down to 15-45℃, add 0.05%-1% post-treatment agent and 0.05%-1% functional additives, adjust the pH to 7.0-9.0 with 0.1%-5% pH stabilizer, and filter to obtain the zero SVOC emission bio-based acrylic emulsion.

10. A method for preparing a zero-SVOC emission bio-based acrylate emulsion as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Preparation of bottom liquid: Mix 30%-40% deionized water and 0.1%-1% emulsifier, and heat to 80-90℃ to obtain bottom liquid; S2: Preparation of pre-emulsion: Mix 5%-10% deionized water, 0.4%-2.4% emulsifier, 1%-15% ethylene monomer, 12%-41% bio-based acrylate monomer, and 0.2%-2% bio-based carboxyl monomer until uniformly dispersed to obtain a core layer pre-emulsion; mix 1%-3% deionized water, 0.5%-1% emulsifier, 4%-15% acrylate monomer, and 0.5%-3% other special monomers until uniformly dispersed to obtain a shell layer pre-emulsion;

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