Emulsion composition and preparation method and application of waterproof emulsion

Abstract

The invention relates to the technical field of waterproof coatings, and particularly discloses an emulsion composition. Comprising the following components in parts by weight: 330 to 350 parts of butyl acrylate, 30 to 40 parts of styrene, 45 to 55 parts of methyl methacrylate, 15 to 20 parts of 2-ethylhexyl acrylate, 1.5 to 1.8 parts of acrylic acid, 85 to 95 parts of modified epoxy resin, 3.8 to 4.2 parts of an anionic emulsifier, 8.5 to 10.8 parts of a nonionic emulsifier, 13 to 18 parts of a cross-linking agent, 1.5 to 1.8 parts of an oxidant, 1.2 to 1.4 parts of tert-butyl hydroperoxide and 0.8 to 1.0 part of sodium hydrogen sulfite. 1 part of a sterilizing agent and 0.3-0.5 part of a defoaming agent; the modified epoxy resin is selected from one or two of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin. The emulsion composition provided by the invention can be used for preparing the waterproof emulsion with good long-acting waterproofness and excellent mechanical properties, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waterproof coating, in particular to a kind of emulsion composition and the preparation method and application of waterproof emulsion. BACKGROUND

[0002] Water-based acrylic emulsion coating is widely used in the field of building waterproofing, decoration and corrosion protection due to its environmental protection, convenient construction and good weather resistance. However, the residual hydrophilic groups such as carboxyl and hydroxyl on the polymer chain segment, and the micro-pores formed by the accumulation of emulsion particles, limit the water barrier ability of the coating film. In long-term high humidity environment or direct immersion conditions, water molecules easily penetrate and cause coating film swelling, strength reduction, and even blistering and peeling, which seriously affects its long-term waterproof reliability.

[0003] To improve the waterproofness and adhesion of acrylic emulsion, the existing technology often uses physical blending to add hydrophobic resin, such as bisphenol A type epoxy resin. This method can improve the compactness of the coating film and the adhesion to the substrate to some extent, but still has some problems, for example: the compatibility of epoxy resin and acrylic emulsion is poor, and simple mixing can easily lead to system instability, resulting in phase separation or viscosity change during storage; in addition, the rigid structure of epoxy resin may damage the mechanical properties of the coating film, making it prone to micro-cracks when the substrate expands and contracts or vibrates slightly, which forms water penetration channels and reduces the waterproofness of the coating film.

[0004] Therefore, it is of great significance to develop a new emulsion composition that can improve the compactness and surface waterproofness of the coating film simultaneously, to promote the development of water-based waterproof coating technology. SUMMARY

[0005] To overcome the problems of poor long-term waterproofness and the inability to balance multiple properties of existing waterproof emulsion, the present application provides a kind of emulsion composition and the preparation method and application of waterproof emulsion.

[0006] In the first aspect, the present application provides an emulsion composition, which adopts the following technical solution: An emulsion composition, comprising the following components by weight: butyl acrylate 330-350 parts, styrene 30-40 parts, methyl methacrylate 45-55 parts, isooctyl acrylate 15-20 parts, acrylic acid 1.5-1.8 parts, modified epoxy resin 85-95 parts, anionic emulsifier 3.8-4.2 parts, non-ionic emulsifier 8.5-10.8 parts, crosslinking agent 13-18 parts, oxidizing agent 1.5-1.8 parts, tert-butyl hydroperoxide 1.2-1.4 parts, sodium bisulfite 0.8-1.0 parts, bactericide 1 part and defoamer 0.3-0.5 parts; The modified epoxy resin is selected from one or both of a perfluoropolyether-modified bisphenol A epoxy resin and a hyperbranched polyester-amine-modified bisphenol A epoxy resin.

[0007] The waterproof emulsion provided by the present application has a core-shell structure and is prepared by using specific acrylate monomers and functional modified epoxy resins as raw materials. The waterproof emulsion can form a continuous and dense high-strength waterproof coating film after curing, thereby achieving long-term protection of the substrate. Specifically, the two novel modified resins, i.e., a perfluoropolyether-modified bisphenol A epoxy resin and a hyperbranched polyester-amine-modified bisphenol A epoxy resin, are compounded in a specific ratio. On the one hand, the surface energy of the coating film can be effectively reduced, and excellent hydrophobicity is imparted to the coating film, so that water droplets are difficult to wet and spread, thereby reducing water adhesion and permeation from the source. On the other hand, the formation of a dense network structure of the coating film is promoted, so that the final coating film not only has sufficient toughness and elasticity to adapt to slight deformation of the substrate and prevent cracking, but also has high hardness, excellent abrasion resistance and chemical corrosion resistance, thereby ensuring the durability of the waterproof effect and prolonging the service life of the coating. The carboxyl groups provided by methyl methacrylate and acrylic acid can enhance the integrity of the polymer network in cooperation with the interaction with the modified epoxy resin and the crosslinking agent. In summary, the selection and ratio optimization of the components of the emulsion composition provided by the present application obtain a waterproof coating with excellent instant waterproofness and long-term water permeation resistance, good adhesion and good toughness, which effectively solves the problems of poor waterproofness and poor toughness of traditional waterproof coatings and provides a reliable solution for realizing high-performance and long-life waterproofing.

[0008] Optionally, the modified epoxy resin is a mixture of the perfluoropolyether-modified bisphenol A epoxy resin and the hyperbranched polyester-amine-modified bisphenol A epoxy resin in a weight ratio of 10: (2.5-6).

[0009] Optionally, the modified epoxy resin is a mixture of the perfluoropolyether-modified bisphenol A epoxy resin and the hyperbranched polyester-amine-modified bisphenol A epoxy resin in a weight ratio of 10: (3.5-5).

[0010] In some embodiments, the weight ratio of the perfluoropolyether-modified bisphenol A epoxy resin and the hyperbranched polyester-amine-modified bisphenol A epoxy resin can be 10: (2.5-3.5), 10: (2.5-4), 10: (2.5-5), 10: (2.5-6), 10: (3.5-4), 10: (3.5-5), 10: (3.5-6), 10: (4-5), 10: (4-6), or 10: (5-6).

[0011] In one specific implementation, the weight ratio of the perfluoropolyether-modified bisphenol A epoxy resin and the hyperbranched polyester-amine-modified bisphenol A epoxy resin can also be 10:2.5, 10:3.5, 10:4, 10:5 or 10:6.

[0012] Optionally, the weight ratio of the perfluoropolyether-modified bisphenol A epoxy resin and the hyperbranched polyester-amine-modified bisphenol A epoxy resin is 10:4.

[0013] Optionally, the anionic emulsifier is an alkyl sulfate; the nonionic emulsifier is an isomeric alcohol ether.

[0014] Secondly, this application provides a method for preparing a waterproof emulsion, which is prepared using the aforementioned emulsion composition, specifically including the following steps: Preparation of emulsion A: Water, anionic emulsifier, nonionic emulsifier, crosslinking agent, butyl acrylate, styrene, and methyl methacrylate are added to an emulsification tank, stirred evenly, and emulsified to obtain emulsion A; Preparation of emulsion B: Water, anionic emulsifier, nonionic emulsifier, crosslinking agent, butyl acrylate, isooctyl acrylate, styrene, acrylic acid, and modified epoxy resin are added to an emulsification tank, stirred evenly and emulsified to obtain emulsion B. Core layer polymerization: Water, anionic emulsifier and nonionic emulsifier are mixed to obtain a base solution, and the temperature is raised to 84-86℃. Then, emulsion A and oxidant solution are slowly added dropwise. After the addition is completed, the mixture is kept warm and stirred for 30-60 minutes. Shell polymerization: After the heat preservation is completed, emulsion B and oxidant solution are added dropwise; after the addition is completed, the reaction is kept at the heat for 1-2 hours.

[0015] Optionally, the preparation method further includes a post-processing step, specifically: after the reaction is completed, the temperature is lowered to 60-70℃, and then tert-butyl hydrogen peroxide solution and sodium bisulfite solution are added dropwise simultaneously. After the reaction is completed, the temperature is maintained for 20-30 minutes; the temperature is further lowered to 40-45℃, the pH is adjusted to 7.8-8.5, and finally an antifoaming agent and a bactericide are added, stirred evenly, and filtered to obtain a waterproof emulsion.

[0016] Optionally, the anionic emulsifier in emulsion A is 2-2.5 parts by weight, and the nonionic emulsifier is 5.2-6.5 parts by weight; the anionic emulsifier in emulsion B is 1-1.2 parts by weight, and the nonionic emulsifier is 2.3-2.8 parts by weight; and the anionic emulsifier in the base coat is 0.5-0.8 parts by weight, and the nonionic emulsifier is 1-1.5 parts by weight.

[0017] Optionally, the dripping time of emulsion A is 1-1.5h, and the dripping time of emulsion B is 2-2.5h.

[0018] Thirdly, this application provides the use of an emulsion composition in a waterproof coating.

[0019] In summary, this application has the following beneficial effects: 1. This application uses butyl acrylate as the matrix and adds one or both of the following as modified epoxy resin components: perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin, thereby preparing a waterproof coating with good mechanical properties and excellent long-lasting waterproof performance.

[0020] 2. In the modified epoxy resin of the further emulsion composition of this application, the weight ratio of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin is controlled in the range of 10:(3.5-5). The resulting waterproof coating has better performance, with a tensile strength of 2.52-2.65 MPa (≥2.50 MPa) after film formation, an elongation at break of 442.7-456.8% (≥440%), an initial water absorption rate of only 6.18-6.63% (<7.0%), and a water absorption rate of only 6.33-6.95% (<7.0%) after temperature and humidity cycling test. Detailed Implementation

[0021] This application provides an emulsion composition comprising the following components in parts by weight: 330-350 parts butyl acrylate, 30-40 parts styrene, 45-55 parts methyl methacrylate, 15-20 parts isooctyl acrylate, 1.5-1.8 parts acrylic acid, 85-95 parts modified epoxy resin, 3.8-4.2 parts anionic emulsifier, 8.5-10.8 parts nonionic emulsifier, 13-18 parts crosslinking agent, 1.5-1.8 parts oxidant, 1.2-1.4 parts tert-butyl hydroperoxide, 0.8-1.0 parts sodium bisulfite, 1 part bactericide, and 0.3-0.5 parts defoamer. The modified epoxy resin is selected from one or both of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin; further, the modified epoxy resin is a mixture of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin in a weight ratio of 10:(2.5-6); even further, the modified epoxy resin is a mixture of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin in a weight ratio of 10:(3.5-5).

[0022] This application also provides a waterproof emulsion prepared using the above-mentioned emulsion composition, the preparation method of which includes the following steps: (1) Preparation of emulsion A: 100-150 parts of water, 2-2.5 parts of anionic emulsifier, 5.2-6.5 parts of nonionic emulsifier, 9-12 parts of crosslinking agent, 200-250 parts of butyl acrylate, 15-20 parts of styrene, and 45-55 parts of methyl methacrylate are added to the emulsion tank in sequence, stirred evenly and emulsified to obtain emulsion A; (2) Preparation of emulsion B: 60-80 parts of water, 1-1.2 parts of anionic emulsifier, 2.3-2.8 parts of nonionic emulsifier, 4-6 parts of crosslinking agent, 100-130 parts of butyl acrylate, 15-20 parts of isooctyl acrylate, 15-20 parts of styrene, 1.5-1.8 parts of acrylic acid, and 85-95 parts of modified epoxy resin are added to the emulsification tank in sequence, stirred evenly and emulsified to obtain emulsion B; (3) Preparation of oxidant: Dissolve 1.5-1.8 parts of oxidant in 10-15 parts of water to obtain an oxidant solution; (4) Core layer polymerization: Add 3-5 parts of water, 0.5-0.8 parts of anionic emulsifier and 1-1.5 parts of nonionic emulsifier to the reactor to obtain the base liquid. Heat to 84-86℃, then add 20% of the total emulsion A. Stir for 3-5 min and then add 10% of the total oxidant solution. After reacting for 15-20 min, raise the temperature to 86-88℃ and then start adding the remaining emulsion A and 50% of the total oxidant solution. Control the adding time of emulsion A to 1-1.5 h and the adding time of oxidant to 0.5-1 h. After the emulsion A is added, continue to keep warm and stir for 30-60 min.

[0023] (5) Shell polymerization: After the heat preservation is completed, emulsion B and oxidant solution accounting for 40% of the total amount are added dropwise, and the dropwise addition time of emulsion B is controlled to be 2-2.5h; after the dropwise addition is completed, the reaction is kept at heat for 1-2h.

[0024] (6) Post-treatment: After the reaction is completed, the temperature is lowered to 60-70℃, and then 60-70% tert-butyl hydrogen peroxide solution (containing 1.2-1.4 parts of tert-butyl hydrogen peroxide) and 30-40% sodium bisulfite solution (containing 0.8-1 parts of sodium bisulfite) are added dropwise in 25-30 minutes. After the reaction is completed, the temperature is kept warm for 20-30 minutes. The temperature is then lowered to 40-45℃, and the pH is adjusted to 7.8-8.5 with 4-5wt% sodium hydroxide solution. Finally, defoamer and bactericide are added, and the mixture is stirred evenly. The mixture is then filtered through a 200-mesh filter cloth to obtain a waterproof emulsion.

[0025] In this application, the bisphenol A epoxy resin is designated E-51 with an epoxy equivalent of 188-192 g / eq; the carboxyl-terminated perfluoropolyether has a molecular weight of 2000 g / mol and an acid value of 32±5 mg KOH / g; and the hydroxyl-terminated hyperbranched polyester-amine is designated Boltorn.® H2O, hydroxyl value 480-520 mg KOH / g; anionic emulsifier is alkyl sulfate CO-436; nonionic emulsifier is isomeric alcohol ether type EH-3; oxidant is ammonium persulfate; crosslinking agent is isocyanate crosslinking agent, model Bayhydur®XP 2655; bactericide is Kathon DL504; defoamer is BYK-012; all raw materials, reagents, solvents, etc. used in this application are commercially available.

[0026] The following describes this application in further detail with reference to preparation examples, embodiments, and performance testing. Preparation Example 1

[0027] Preparation Example 1 provides a perfluoropolyether modified bisphenol A epoxy resin.

[0028] The preparation method of the above-mentioned perfluoropolyether modified bisphenol A epoxy resin includes the following steps: 850g of bisphenol A epoxy resin and 150g of carboxyl-terminated perfluoropolyether are added to a dry four-necked flask. Nitrogen gas is continuously introduced into the system, the temperature is raised to 80℃, and the mixture is stirred at 300 r / min for 30 min. Then, 1.5g of triphenylphosphine catalyst is added to the reaction system, and 200g of toluene is added as a dehydrating agent. A reflux condenser and a water separator are installed, and the reaction system is slowly heated to 120℃ and refluxed for 10 h. After the reaction is completed, the temperature is lowered, and then vacuum distillation is carried out at 70℃ and -0.095 MPa to obtain a light yellow, viscous, transparent perfluoropolyether modified bisphenol A epoxy resin. Preparation Example 2

[0029] Preparation Example 2 provides a hyperbranched polyester-amine modified bisphenol A epoxy resin.

[0030] The preparation method of the above-mentioned mixture of hyperbranched polyester-amine modified bisphenol A epoxy resin includes the following steps: 900g of bisphenol A epoxy resin is added to a dry four-necked flask, nitrogen gas is introduced, the temperature is raised to 60°C, 100g of terminal hydroxyl hyperbranched polyester-amine and 0.05g of hydroquinone are added, and the mixture is stirred and mixed at 60°C and 300r / min for 30min, then the temperature is raised to 80°C and the mixture is stirred and mixed for another 30min; then 1.0g of triphenylphosphine catalyst is added to the system, the temperature is raised to 110°C, and the reaction is stirred continuously for 4-6h; after the reaction is completed, the temperature is lowered, and then vacuum distillation is carried out at 70°C and -0.095 MPa to obtain amber-colored transparent hyperbranched polyester-amine modified bisphenol A epoxy resin. Example 1

[0031] Example 1 provides a waterproof emulsion.

[0032] The preparation method of the above-mentioned waterproof emulsion includes the following steps: (1) Preparation of emulsion A: 130g of water, 2.3g of anionic emulsifier, 5.8g of nonionic emulsifier, 10g of crosslinking agent, 230g of butyl acrylate, 18g of styrene and 50g of methyl methacrylate are added to the emulsion tank in sequence, stirred evenly and emulsified to obtain emulsion A; (2) Preparation of emulsion B: 70g of water, 1.1g of anionic emulsifier, 2.5g of nonionic emulsifier, 5g of crosslinking agent, 120g of butyl acrylate, 18g of isooctyl acrylate, 18g of styrene, 1.6g of acrylic acid, and 90g of perfluoropolyether modified bisphenol A epoxy resin were added to the emulsification tank in sequence, stirred evenly and emulsified to obtain emulsion B; (3) Preparation of oxidant: Dissolve 1.7g of oxidant in 13g of water to obtain an oxidant solution; (4) Core layer polymerization: Add 4g water, 0.6g anionic emulsifier and 1.3g nonionic emulsifier to the reactor as a base liquid, heat to 85℃, then add 20% of the total emulsion A, stir for 3 min and then add 10% of the total oxidant solution. After reacting for 20 min, raise the temperature to 88℃, and then start to add the remaining emulsion A and 50% of the total oxidant solution dropwise. Control the dropwise addition time of emulsion A to about 1 h and the dropwise addition time of oxidant to 0.5 h. After the emulsion A is added, continue to keep warm and stir for 30 min.

[0033] (5) Shell polymerization: After the heat preservation is completed, emulsion B and oxidant solution accounting for 40% of the total amount are added dropwise, and the dropwise addition time of emulsion B is controlled to be 2h; after the dropwise addition is completed, the heat preservation reaction is continued for 2h.

[0034] (6) Post-treatment: After the reaction is completed, the temperature is lowered to 60°C, and then 70% tert-butyl hydrogen peroxide solution (containing 1.2-1.4g of tert-butyl hydrogen peroxide) and 35% sodium bisulfite solution (containing 0.8-1g of sodium bisulfite) are added dropwise simultaneously. The addition is completed in 30 minutes, and the temperature is kept warm for 30 minutes after the reaction is completed. The temperature is then lowered to 40°C, and the pH is adjusted to 8.0 with 4wt% sodium hydroxide solution. Finally, defoamer and bactericide are added, stirred evenly, and filtered through a 200-mesh filter cloth to obtain a waterproof emulsion. Example 2

[0035] Example 2 provides a waterproof emulsion.

[0036] The difference between the above embodiments and Embodiment 1 is that the perfluoropolyether modified bisphenol A epoxy resin is replaced with hyperbranched polyester-amine modified bisphenol A epoxy resin. Examples 3-7

[0037] Examples 3-7 each provide a waterproof emulsion.

[0038] The difference between the above embodiments and Embodiment 1 is that the modified epoxy resin is a mixture of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin, and its formulation is shown in Table 1 below.

[0039] Table 1. Types and proportions of modified epoxy resins in Examples 3-7 Comparative Example 1

[0040] Comparative Example 1 provides a waterproof emulsion.

[0041] The difference between the above comparative example and Example 1 is that the perfluoropolyether modified bisphenol A epoxy resin is replaced with bisphenol A epoxy resin. Application Examples 1-7

[0042] Application Examples 1-7 each provide a waterproof coating.

[0043] The difference between the above application examples is that the waterproof emulsion in the waterproof coating is derived from Examples 1-7.

[0044] The above-mentioned waterproof coating is made by mixing the following raw materials in the following proportions: 400g of waterproof emulsion, 4.0g of ammonium salt dispersant 9180, 2.0g of defoamer 4201, 1.0g of organic amine additive AMP-95, 50.0g of titanium dioxide 298, 400.0g of high-gloss barium sulfate, 2.0g of defoamer 4201, 1.0g of bactericide, 3.3g of 50wt% 936 thickener solution, and 130g of water are mixed evenly to obtain the waterproof coating. Comparative Application Example 1

[0045] Comparative application example 1 provides a waterproof coating.

[0046] The difference between the above comparative application example and application example 1 is that the waterproof emulsion in the waterproof coating of comparative application example 1 is derived from comparative example 1. Performance testing

[0047] The tensile strength, elongation at break, and water absorption of the waterproof coating in Application Example 1 were tested in accordance with Examples 1-7, and the results are shown in Table 2 below.

[0048] (1) Tensile strength and elongation at break shall be tested in accordance with JC / T 864-2023; (2) Water absorption rate and long-term waterproof performance: The waterproof coating was sprayed according to the standard process and cured for 7 days to obtain a coating film with a thickness of 200±20μm. The initial water absorption rate of the coating film was tested. Then the coating film was placed under the following temperature and humidity cycling conditions: 50℃, 90%RH, 12h → 25℃, 30%RH, 12h, for a total of 50 cycles. After the cycle, the water absorption rate of the coating film was tested. The water absorption rate was tested according to the mass change rate in JC / T 2663-2022, with a soaking time of 168±1h.

[0049] Table 2 Performance test results of waterproof coatings in Application Examples 1-7 and Comparative Application Example 1

[0050] According to the test results in Table 2, the waterproof coatings prepared using the waterproof emulsions of Examples 1-7 have a tensile strength of 2.07-2.65 MPa, an elongation at break of 404.8-463.1%, an initial water absorption rate of 6.18-8.10%, and a water absorption rate of 6.33-9.35% after a temperature and humidity cycling test. In contrast, the waterproof coating prepared using the waterproof emulsion of Comparative Example 1 has a tensile strength of only 1.47 MPa, an elongation at break of only 341.0%, an initial water absorption rate as high as 11.07%, and a water absorption rate as high as 14.89% after a temperature and humidity cycling test. Therefore, this application demonstrates that the waterproof emulsion prepared using one or both of the following epoxy resin components—perfluoropolyether-modified bisphenol A epoxy resin and hyperbranched polyester-amine-modified bisphenol A epoxy resin—possesses excellent mechanical properties and hydrophobicity, and the waterproof coatings prepared using it can achieve long-term protection of the substrate.

[0051] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. An emulsion composition, characterized in that, The product comprises the following components in parts by weight: 330-350 parts butyl acrylate, 30-40 parts styrene, 45-55 parts methyl methacrylate, 15-20 parts isooctyl acrylate, 1.5-1.8 parts acrylic acid, 85-95 parts modified epoxy resin, 3.8-4.2 parts anionic emulsifier, 8.5-10.8 parts nonionic emulsifier, 13-18 parts crosslinking agent, 1.5-1.8 parts oxidant, 1.2-1.4 parts tert-butyl hydroperoxide, 0.8-1.0 parts sodium bisulfite, 1 part bactericide, and 0.3-0.5 parts defoamer; The modified epoxy resin is selected from one or both of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin.

2. The emulsion composition according to claim 1, characterized in that, The modified epoxy resin is a mixture of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin in a weight ratio of 10:(2.5-6).

3. The emulsion composition according to claim 1, characterized in that, The modified epoxy resin is a mixture of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin in a weight ratio of 10:(3.5-5).

4. The emulsion composition according to claim 1, characterized in that, The modified epoxy resin is a mixture of perfluoropolyether modified bisphenol A epoxy resin and hyperbranched polyester-amine modified bisphenol A epoxy resin in a weight ratio of 10:(4).

5. The emulsion composition according to any one of claims 1-4, characterized in that, The anionic emulsifier is an alkyl sulfate; the nonionic emulsifier is an isomeric alcohol ether.

6. A method for preparing a waterproof emulsion, characterized in that, The emulsion composition prepared using any one of claims 1-5 specifically includes the following steps: Preparation of emulsion A: Water, anionic emulsifier, nonionic emulsifier, crosslinking agent, butyl acrylate, styrene, and methyl methacrylate are added to an emulsification tank, stirred evenly, and emulsified to obtain emulsion A; Preparation of emulsion B: Water, anionic emulsifier, nonionic emulsifier, crosslinking agent, butyl acrylate, isooctyl acrylate, styrene, acrylic acid, and modified epoxy resin are added to an emulsification tank, stirred evenly and emulsified to obtain emulsion B. Core layer polymerization: Water, anionic emulsifier and nonionic emulsifier are mixed to obtain a base solution, and the temperature is raised to 84-86℃. Then, emulsion A and oxidant solution are slowly added dropwise. After the addition is completed, the mixture is kept warm and stirred for 30-60 minutes. Shell polymerization: After the heat preservation is completed, emulsion B and oxidant solution are added dropwise; after the addition is completed, the reaction is kept at the heat for 1-2 hours.

7. The method for preparing the waterproof emulsion according to claim 6, characterized in that, The preparation method also includes a post-processing step, specifically: after the reaction is completed, the temperature is lowered to 60-70℃, and then tert-butyl hydrogen peroxide solution and sodium bisulfite solution are added dropwise simultaneously. After the reaction is completed, the temperature is maintained for 20-30 minutes; the temperature is further lowered to 40-45℃, the pH is adjusted to 7.8-8.5, and finally defoamer and bactericide are added, stirred evenly, and filtered to obtain a waterproof emulsion.

8. The method for preparing the waterproof emulsion according to claim 6, characterized in that, The emulsion A contains 2-2.5 parts by weight of anionic emulsifier and 5.2-6.5 parts by weight of nonionic emulsifier; the emulsion B contains 1-1.2 parts by weight of anionic emulsifier and 2.3-2.8 parts by weight of nonionic emulsifier; and the base coat contains 0.5-0.8 parts by weight of anionic emulsifier and 1-1.5 parts by weight of nonionic emulsifier.

9. The method for preparing the waterproof emulsion according to claim 6, characterized in that, The dripping time of emulsion A is 1-1.5h, and the dripping time of emulsion B is 2-2.5h.

10. The use of the emulsion composition according to any one of claims 1-5 in waterproof coatings.

Images