Highly dispersed polymer cement waterproof coating and preparation method thereof

Abstract

This invention relates to the field of waterproof coatings, and particularly to a highly dispersible polymer cement waterproof coating and its preparation method. The raw materials include a liquid component A and a powder component B, in parts by mass. Liquid component A comprises: a modified polymer emulsion, defoamer I, a preservative, water, a wetting agent, and a silane coupling agent. Powder component B comprises: cement, heavy calcium carbonate, quartz powder, a highly dispersible water-reducing agent, and defoamer II. The modified polymer emulsion comprises a composite emulsifier, mixed unsaturated acids, mixed monomers, an initiator, and water. The mixed monomers include butyl acrylate and tripropylene phosphite or their homologues. The highly dispersible polymer waterproof coating provided by this invention can effectively improve the dispersion performance of the matrix material, effectively adsorb and encapsulate powder particles, increase the lubrication performance between particles, release more solution, break up agglomerated structures, improve bonding strength, and slightly improve mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of waterproof coatings, and in particular to a highly dispersible polymer cement waterproof coating and its preparation method. Background Technology

[0002] Polymer cement waterproof coatings are widely used for waterproofing bathrooms, kitchens, balconies, and other areas due to their excellent environmental friendliness, strong adhesion to damp substrates, and "rigid yet flexible" properties. They also offer high durability and weather resistance, making them a cost-effective and high-performance water-based waterproof coating. Polymer cement waterproof coatings are two-component flexible coatings with polymer emulsions and fillers such as cement and calcium carbonate as the main binding materials. For on-site use, the liquid and powder components are thoroughly mixed and then directly applied to the substrate. Polymer cement waterproof coatings offer excellent waterproofing effects, are easy to apply, have high film strength, and strong adhesion. They can be applied to masonry, concrete, and gypsum board substrates. After application, mortar plastering and tile adhesion can be directly performed on the waterproof membrane.

[0003] When mixing the powder and liquid components of polymer cement waterproof coatings, prolonged and vigorous mechanical stirring is generally required, especially for Type III products specified in GB / T23445-2009 standard. Incomplete stirring can lead to clumping in the system, severely affecting the workability of the material. This is mainly because cement and other powder particles tend to agglomerate during powder-liquid mixing. Adding appropriate water-reducing agents to polymer cement waterproof coatings can improve the product's mixing and dispersibility, making the coating smoother to apply and resulting in excellent physical and mechanical properties after film formation. However, since polymer cement waterproof coatings are expected to be usable quickly after powder-liquid mixing, existing water-reducing agents have low dispersibility for polymer cement waterproof coatings with low polymer-to-ash ratios, requiring a large solution volume to extend sterically hindered groups. For example, Chinese patent document CN116004059A discloses a rapidly dispersible polymer cement waterproof coating and its preparation method, but the dispersant used is a common polycarboxylate dispersant, which has poor dispersion effects on the coating. Summary of the Invention

[0004] To address the shortcomings of existing polymer cement waterproof coatings in terms of insufficient dispersibility, this invention provides a highly dispersible polymer cement waterproof coating and its preparation method.

[0005] This invention provides a highly dispersible polymer cement waterproof coating, the raw materials of which include liquid component A and powder component B. By mass parts, liquid component A includes: 85-95 parts of modified polymer emulsion, 0.1-1 parts of defoamer I, 0.05-0.1 parts of preservative, 5-15 parts of water, 0.1-0.5 parts of wetting agent, and 0.5-1 parts of silane coupling agent;

[0006] The powder component B includes: 60-100 parts of cement, 10-20 parts of heavy calcium carbonate, 30-80 parts of quartz powder, 0.1-1 parts of highly dispersible water-reducing agent, and 0.1-1 parts of defoamer II;

[0007] The modified polymer emulsion comprises a composite emulsifier, a mixture of unsaturated acids, a mixture of monomers, an initiator, and water, wherein the mixture of monomers comprises butyl acrylate and tripropylene phosphite or their homologues;

[0008] The mass ratio of liquid component A to powder component B is 1:1 to 2.

[0009] Furthermore, by mass parts, the modified polymer emulsion comprises 1.5 to 3 parts of a composite emulsifier, 1.5 to 3 parts of a mixed unsaturated acid, 35 to 40 parts of butyl acrylate, 12 to 18 parts of tripropylene phosphite or its homologue, 0.5 to 1 part of an initiator, and 50 to 60 parts of water.

[0010] Furthermore, the composite emulsifier includes a nonionic emulsifier and anionic emulsifier, wherein the mass ratio of the nonionic emulsifier to the anionic emulsifier is 1:0.5 to 1;

[0011] The mixed unsaturated acid includes acrylic acid and methacrylic acid, wherein the mass ratio of acrylic acid to methacrylic acid is 1:0.5 to 1;

[0012] The nonionic emulsifier is OP-10 or OP-15, and the anionic emulsifier is sodium dodecyl sulfate;

[0013] The initiator is ammonium persulfate or potassium persulfate.

[0014] Furthermore, the structural formula of the tripropylene phosphite or its homologue is as follows:

[0015]

[0016] Where a, b, c = 1 to 3; R1, R2, R3 are H or CH3.

[0017] When a, b, c = 1 and R1, R2, R3 are CH3, the compound is tris(2-methylpropenoxy)phosphine; when a, b, c = 2 and R1, R2, R3 are H, the compound is 3-buten-1-olphosphate.

[0018] Furthermore, the preparation method of the modified polymer emulsion includes the following steps:

[0019] S1. Mix the first part of composite emulsifier, mixed unsaturated acid, first part of water and first part of mixed monomer, heat to 45-50℃ and stir evenly to obtain emulsion prepreg;

[0020] S2. Mix the second part of the composite emulsifier, the second part of the water, the first part of the initiator and the second part of the mixed monomer, heat to 45-50℃ and stir evenly to obtain the seed emulsion;

[0021] S3. Mix the second part of the initiator, seed emulsion and emulsion prepreg, heat to 60-90°C and stir evenly to obtain the modified polymer emulsion;

[0022] Preferably, the first part of the composite emulsifier accounts for 75% to 86% of the total composite emulsifier, and the second part of the composite emulsifier accounts for 14% to 25% of the total composite emulsifier;

[0023] And / or, the first portion of the mixed monomers comprises 75% to 86% of the total mixed monomers, and the second portion of the mixed monomers comprises 14% to 25% of the total mixed monomers;

[0024] And / or, the first portion of the initiator comprises 75% to 86% of the total initiator, and the second portion of the initiator comprises 14% to 25% of the total initiator;

[0025] The sum of the amounts of the first and second portions of water is the total amount of water.

[0026] Furthermore, the defoamer I is one or more of polymethylphenylsiloxane and polydimethylsiloxane;

[0027] The preservative is one or more selected from 2-ethyl-4-isothiazolinone or 2-octyl-4-isothiazolinone, and octadecyl dimethyl benzyl ammonium bromide;

[0028] The wetting agent is sodium tripolyphosphate;

[0029] The silane coupling agent is one or more of KH560 and KH570;

[0030] The cement is ordinary Portland cement;

[0031] The heavy calcium carbonate is one or more of 800 mesh calcium carbonate and 1250 mesh calcium carbonate;

[0032] The defoamer II is one or more of polypropylene glycol fatty acid ester, dodecyl polyoxyethylene ether, or nonylphenol polyoxyethylene ether;

[0033] The highly dispersed water-reducing agent includes polyether macromonomers, oxidants, reducing agents, chain transfer agents, acrylic acid, and functional monomers.

[0034] Furthermore, by weight, the highly dispersible water-reducing agent comprises 100 parts of polyether macromonomer, 0.5-3 parts of oxidant, 0.5-3 parts of reducing agent, 0.5-1.5 parts of chain transfer agent, 8-15 parts of acrylic acid, and 0.5-2 parts of functional monomer;

[0035] The polyether macromonomer is ethylene glycol monovinyl polyethylene glycol ether or 4-hydroxybutylvinyl polyoxyethylene ether;

[0036] Furthermore, the functional monomer is trimethylsilylbutyrate or its homologue, and the structural formula of the functional monomer is:

[0037]

[0038] Where a = 0 to 3; b, c = 0 to 4; d = 0 to 5; e = 0 to 2; R1, R2 are H or CH3.

[0039] When a, b, c, d, e = 0 and R1, R2 are H, the compound is trimethylsilylbut-3-enoate.

[0040] Furthermore, the preparation method of the highly dispersed water-reducing agent is as follows: the polyether macromonomer is added to a reaction vessel and mixed with water. After stirring evenly, the oxidant is added, and then solution A and solution B are added dropwise respectively. The reaction is carried out at room temperature for 50-70 minutes. After the reaction is completed, the temperature is kept warm for 30-60 minutes, and liquid alkali is added to adjust the pH to 6-7 to obtain the highly dispersed water-reducing agent.

[0041] Solution A is a mixed solution of the reducing agent and the chain transfer agent, and solution B is a mixed solution of the acrylic acid and the functional monomer. It should be understood that room temperature refers to approximately 25°C.

[0042] The present invention also provides a method for preparing the above-mentioned highly dispersed polymer cementitious waterproof coating, comprising the following steps:

[0043] (1) Preparation of liquid component A: Add water, defoamer I and modified polymer emulsion to a container, adjust the speed to 700-1100 rpm, and stir for 2-3 min;

[0044] Reduce the speed to 300-500 rpm, add the second part of defoamer I, silane coupling agent and wetting agent to the container, and continue stirring for 5-10 minutes;

[0045] Add preservatives to the container and stir for 30-40 minutes to obtain liquid component A;

[0046] (2) Preparation of powder component B: Cement, heavy calcium carbonate and quartz powder are ground and then dispersed and mixed with high dispersible water-reducing agent and defoamer II to obtain powder component B;

[0047] (3) Mix the liquid component A and the powder component B in a certain proportion to obtain the highly dispersed polymer cement waterproof coating.

[0048] Furthermore, the first part of defoamer I is half of the total amount of defoamer, and the second part of defoamer I is half of the total amount of defoamer.

[0049] Compared with the prior art, the highly dispersed polymer cement waterproof coating provided by the present invention has the following beneficial effects:

[0050] 1. The polymer emulsion of component A in this invention is modified by introducing highly dispersible groups such as tripropylene phosphite or its homologues to improve the dispersion performance of the polymer emulsion. The inclusion of phosphate-containing monomers into the polymer chain enhances the polymer's hydrophilicity and charge. This is beneficial for the stable dispersion of polymer particles in the aqueous phase. Furthermore, the strong polarity of phosphate-containing monomers during polymerization enhances the mutual repulsion between polymer chain segments, leading to better dispersion.

[0051] 2. Component B of this invention introduces trimethylsilyl but-3-enoate or its homologues, which contain multiple methyl groups, siloxane bonds, and ester groups in the molecule. The multiple methyl groups introduced into the main chain of the water-reducing agent greatly improve the flexibility of the water-reducing agent, enabling it to be quickly adsorbed on the surface of cement and heavy calcium carbonate particles, resulting in a high adsorption rate and thus rapid dispersion of cement particles under low-temperature conditions. Meanwhile, the ester groups are continuously hydrolyzed under alkaline conditions of cement, and sufficient adsorption groups (carboxyl groups) are added in the later stage, resulting in better flow properties of the slurry.

[0052] 3. Both components A and B of this invention contain highly dispersed groups, exhibiting good compatibility when mixed;

[0053] 4. The process of this invention is simple to operate, the reaction conditions are mild, it is easy to scale up production, the production process is safe and pollution-free, and it is an environmentally friendly product. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] This invention provides a highly dispersible polymer cement waterproof coating, the raw materials of which include liquid component A and powder component B. By mass parts, liquid component A includes: 85-95 parts of modified polymer emulsion, 0.1-1 parts of defoamer I, 0.05-0.1 parts of preservative, 5-15 parts of water, 0.1-0.5 parts of wetting agent, and 0.5-1 parts of silane coupling agent;

[0056] The powder component B includes: 60-100 parts of cement, 10-20 parts of heavy calcium carbonate, 30-80 parts of quartz powder, 0.1-1 parts of highly dispersible water-reducing agent, and 0.1-1 parts of defoamer II.

[0057] The present invention also provides an operational example of the preparation method of the above-mentioned highly dispersed polymer cementitious waterproof coating, including the following steps:

[0058] (1) Preparation of modified polymer emulsion:

[0059] S11. Mix the first part of composite emulsifier, mixed unsaturated acid, first part of water and first part of mixed monomer, heat to 45-50℃ and stir evenly to obtain emulsion prepreg.

[0060] S12. Mix the second part of the composite emulsifier, the second part of the water, the first part of the initiator and the second part of the mixed monomer, heat to 45-50°C and stir evenly to obtain the seed emulsion.

[0061] S13. The second part of the initiator, seed emulsion and emulsion prepreg are mixed, heated to 60-90°C and stirred to obtain the modified polymer emulsion;

[0062] (2) Preparation of liquid component A:

[0063] S21. Take water, defoamer I (part 1), and modified polymer emulsion and add them to a container. Adjust the speed to 700-1100 rpm and stir for 2-3 minutes.

[0064] S22. Reduce the speed to 300-500 rpm, add the second part of defoamer I, silane coupling agent and wetting agent to the container, and continue stirring for 5-10 minutes;

[0065] S23. Add preservative to the container and stir for 30-40 minutes to obtain liquid component A;

[0066] (3) Preparation of highly dispersed water-reducing agent: Add polyether macromonomer to the reaction vessel and mix with water. After stirring evenly, add oxidant, and then add solution A and solution B dropwise. React at room temperature for 50-70 min. After the reaction is completed, keep warm for 30-60 min, add liquid alkali to adjust pH to 6-7, and the highly dispersed water-reducing agent is obtained.

[0067] Solution A is a mixed solution of a reducing agent and a chain transfer agent, and solution B is a mixed solution of acrylic acid and a functional monomer.

[0068] (4) Preparation of powder component B: Cement, heavy calcium carbonate and quartz powder are ground and then dispersed and mixed with high dispersible water-reducing agent and defoamer II to obtain powder component B;

[0069] (5) Mix the liquid component A and the powder component B in a certain proportion to obtain the highly dispersed polymer cement waterproof coating.

[0070] Example 1

[0071] (1) Preparation of modified polymer emulsion:

[0072] S1. Mix the first part of the composite emulsifier (0.75 parts of OP-10 and 0.375 parts of sodium dodecyl sulfate), the mixed unsaturated acid (1 part of acrylic acid and 1 part of methacrylic acid), the first part of the mixed monomer (26.25 parts of butyl acrylate and 13.5 parts of tripropylene phosphite) with 48 parts of water, heat to 40°C, and stir at 900 rpm for 30 minutes. After mixing evenly, a stable emulsion preform is obtained.

[0073] S2. Mix the second part of the composite emulsifier (0.25 parts OP-10, 0.125 parts sodium dodecyl sulfate), 8 parts water, 0.375 parts ammonium persulfate with the second part of the mixed monomers (8.75 parts butyl acrylate, 4.5 parts tripropylene phosphite), heat to 40°C, and stir at 900 rpm for 80 min. After mixing evenly, the seed emulsion is obtained.

[0074] S3. Mix 0.125 parts of ammonium persulfate, the emulsion prepreg prepared in S1 and the seed emulsion prepared in S2, heat to 90°C and stir at 900 rpm for 5 hours. After the reaction is completed, the modified polymer emulsion is obtained.

[0075] (2) Preparation of liquid component A:

[0076] S21. Add 85 parts of the modified polymer emulsion obtained in step (1), 8 parts of water, and 0.4 parts of polymethylphenylsiloxane to the reaction vessel and stir at 700 rpm for 2 min.

[0077] S22. Reduce the stirring speed to 300 rpm, add 0.4 parts of polymethylphenylsiloxane, 0.5 parts of sodium tripolyphosphate and 0.8 parts of KH560 to the reaction vessel, and continue stirring for 7 min;

[0078] S23. Add 0.05 parts of 2-ethyl-4-isothiazolinone to the reaction vessel and continue stirring for 30 min to obtain liquid component A;

[0079] (3) Preparation of highly dispersed water-reducing agent:

[0080] 100 parts of ethylene glycol monovinyl polyethylene glycol ether and 80 parts of water were added to a reaction vessel and stirred until homogeneous. Then, 2 parts of cumene hydrogen peroxide were added. 3 parts of sodium hypophosphite, 1.1 parts of mercaptoacetic acid, and 30 parts of water were mixed to form solution A in the first dropping device. 12 parts of acrylic acid, 0.5 parts of trimethylsilyl butyl-3-acrylate, and 8 parts of water were mixed to form solution B in the second dropping device. The materials from the first and second dropping devices were added dropwise to the reaction vessel sequentially at room temperature. The materials from the second and first dropping devices were added dropwise after 50 minutes, and the reaction was maintained at a constant temperature for 30 minutes. 2 parts of 32% sodium hydroxide were added to obtain the highly dispersed water-reducing agent with a concentration of 50%.

[0081] (4) Preparation of powder component B:

[0082] 80 parts of ordinary silicate cement, 10 parts of 800-mesh calcium carbonate and 50 parts of quartz powder were added to a planetary ball mill and ground for 3 hours. Then, the ground material, 0.3 parts of the highly dispersible water-reducing agent obtained in step (3) and 0.3 parts of polypropylene glycol fatty acid ester were added to a dispersion kettle and dispersed for 5 minutes to obtain powder component B.

[0083] (5) Preparation of highly dispersed polymer cementitious waterproof coating:

[0084] Mix 100 parts of liquid component A obtained in step (2) with 100 parts of powder component B obtained in step (4) using a stirring rod, and after stirring evenly, obtain the highly dispersed polymer cement waterproof coating.

[0085] Comparative Example 1

[0086] Unlike Example 1, in step (1) of preparing the modified polymer emulsion, tripropylene phosphite is not added, and the remaining raw materials and processes are the same as in Example 1.

[0087] Comparative Example 2

[0088] Unlike Example 1, in step (1) of preparing the modified polymer emulsion, tripropylene phosphite was replaced by dipropylene methylphosphonate by mass, while the other raw materials and processes were the same as in Example 1.

[0089] Comparative Example 3

[0090] Unlike Example 1, in step (3) of preparing the highly dispersed water-reducing agent, trimethylsilyl but-3-olefin ester is not added, and the other raw materials and processes are the same as in Example 1.

[0091] Comparative Example 4

[0092] Unlike Example 1, in step (3) preparation of the highly dispersed water-reducing agent, trimethylsilyl butyl-3-enoate was replaced by benzyl-2-methyl-3-butenoate, and the remaining raw materials and processes were the same as in Example 1.

[0093] Comparative Example 5

[0094] Unlike Example 1, in step (3) of preparing the highly dispersed water-reducing agent, ethylene glycol monovinyl polyethylene glycol ether is replaced by isopentenyl polyethylene glycol ether by mass, and the remaining raw materials and processes are the same as in Example 1.

[0095] Comparative Example 6

[0096] The commercially available BYW-03JS type polymer cement waterproof coating is available.

[0097] Comparative Example 7

[0098] Unlike Example 1, in step (5), the weight of powder B is 210 parts, and the remaining raw materials and processes are the same as in Example 1.

[0099] The polymer cement waterproof coatings prepared in the examples and comparative examples were subjected to performance tests:

[0100] (1) Flowability test: Refer to the test method in 6.7 of JC / T 985-2005 "Cement-based self-leveling mortar for ground", use a cylinder with an inner diameter of 3cm and a height of 5cm, fill it with the sample and lift it up. Utilize the weight of the sample to flow and form a circular plane. Measure the diameter in two perpendicular directions. The test result is expressed as the average diameter.

[0101] (2) Mechanical property testing:

[0102] The polymer cement waterproof coating was applied in three coats to the mold specified in GB / T 23445 7.4.1. Each coat was allowed to fully dry before the next coat was applied. The thickness of the polymer cement waterproof coating film reached 1.5 ± 0.2 mm. The film was cured under standard test conditions for 96 hours before demolding. The demolded sample was then turned over and cured in an oven at 40 ± 2℃ for 48 hours. After cooling to room temperature in a desiccator, the film was cut into Type I dumbbell shapes according to GB / T 23445 7.4.2, and its tensile strength and elongation at break were tested according to GB / T 23445 7.4.3.

[0103] (3) Bond strength test: Apply the polymer cement waterproof coating in multiple layers to the substrate specified in GB / T 23445 7.6.2.1, with a coating thickness of 1.5 mm. Cure the substrate and the coating under standard test conditions for 96 h, in an oven at 40±2℃ for 48 h, and place under standard test conditions for 4 h. Perform the bond strength test according to GB / T 23445 7.6.3.1.

[0104] (4) Permeability pressure test: Apply polymer cement waterproof coating in multiple layers to the permeable mortar specimen in Appendix A 2.1 of GB / T 23445. Apply two coats on the back side. After the first coat (0.5-0.6 mm) is surface dry, apply the second coat (the total thickness of the two coats is 1.0-1.2 mm). After the second coat is surface dry, place it in the cement standard curing room for 168 hours. The curing conditions are: temperature 20±1℃, relative humidity not less than 90%.

[0105] The test results are shown in Table 1:

[0106] Table 1. Sample Waterproof Performance Test Record

[0107]

[0108] As can be seen from the test results in Table 1:

[0109] Adding the highly dispersible polymer cement waterproof coating prepared according to this invention significantly improves the fluidity of the slurry, and the higher the ratio of liquid to powder, the better the fluidity. Simultaneously, the tensile strength, elongation at break, and bond strength of the coating film also increase substantially. This indicates that the highly dispersible polymer cement waterproof coating of this invention has good dispersibility. The phosphate groups in the modified polymer emulsion and the multiple methyl, siloxane, and ester groups in the highly dispersible water-reducing agent adsorb and encapsulate the powder particles, increasing the lubrication between particles, releasing more solution, and breaking down agglomerated structures. On the one hand, this facilitates the waterproof coating's easy penetration into the shallow surface layer of the material; on the other hand, it helps to ensure uniform distribution of powder particles, improving the overall density of the waterproof material and thus enhancing its waterproof performance.

[0110] The test results from Example 1 and Comparative Examples 1-2 show that:

[0111] The difference between Comparative Example 1 and Example 1 is that Comparative Example 2 did not contain tripropylene phosphite; the difference between Comparative Example 2 and Example 1 is that Comparative Example 2 used diallyl methylphosphonate instead of tripropylene phosphite.

[0112] In this embodiment of the invention, tripropylene phosphite is used to prepare modified polymer emulsions. Compared to Comparative Example 1, the waterproof coating prepared in this embodiment exhibits significantly improved fluidity. Compared to Comparative Example 2, the fluidity of this embodiment is slightly improved, thanks to the strong polarity of the phosphate groups, which enhances the adsorption performance of powder particles and improves dispersibility. Comparative Example 2 also contains phosphate groups, but compared to this embodiment, it has one less propionate ester group attached to the phosphate group, resulting in a less significant improvement in fluidity. Similarly, the mechanical properties of this embodiment are superior to those of the comparative example, thanks to the excellent dispersibility provided by tripropylene phosphite, which results in better adhesion to the substrate.

[0113] The test results from Example 1 and Comparative Examples 3-4 show that:

[0114] The difference between Comparative Example 3 and Example 1 is that it does not contain trimethylsilylbut-3-enoate; the difference between Comparative Example 4 and Example 1 is that it uses benzyl 2-methyl-3-butenoate instead of trimethylsilylbut-3-enoate.

[0115] In this embodiment of the invention, trimethylsilylbut-3-enoate is used to prepare a highly dispersible water-reducing agent in component B of the powder. Compared with the schemes of Comparative Examples 3-4, the waterproof coating prepared in this embodiment has a significantly better flowability than the comparative examples. This is due to the excellent dispersibility of trimethylsilylbut-3-enoate, which helps to break up the agglomeration of powder particles and release more solution.

[0116] The test results from Example 1 and Comparative Example 5 show that:

[0117] The difference between Comparative Example 5 and Example 1 is that it uses isopentenyl polyethylene glycol ether instead of ethylene glycol monovinyl polyethylene glycol ether;

[0118] In this embodiment of the invention, ethylene glycol monovinyl polyethylene glycol ether is used to prepare a highly dispersed water-reducing agent in the powder component. Compared with the scheme of Comparative Example 5, the waterproof material prepared in this embodiment has greater flow properties, mechanical properties and impermeability pressure than the comparative example. The water-reducing agent is synthesized using this polyether, and its water-reducing agent performance is lower than that of the highly dispersed water-reducing agent in this embodiment.

[0119] The test results from Example 1 and Comparative Example 6 show that:

[0120] Compared to the commercially available BYW-03JS polymer cement waterproof coating in Comparative Example 6, the waterproof coating provided in this embodiment of the invention has higher fluidity, as well as higher bonding strength and impermeability.

[0121] The test results from Example 1 and Comparative Example 7 show that:

[0122] Compared to Comparative Example 7, where the liquid-to-material ratio was 1:2.1, the liquid-to-material ratio of the Example 1:1 is within a reasonable range. The flowability of the Example is higher than that of Comparative Example 7. The high flowability of the Example greatly helps the waterproof coating penetrate into the substrate and improves the adhesion performance.

[0123] In summary, the highly dispersible polymer waterproof coating provided by this invention effectively improves the dispersion performance of the matrix material, effectively adsorbs and encapsulates powder particles, increases the lubrication performance between particles, releases more solution, breaks up agglomerated structures, and its high fluidity allows for better penetration into the matrix, improving adhesion strength and slightly enhancing mechanical properties. It also exhibits good impermeability and waterproofing properties, demonstrating promising application prospects and widespread application value.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly dispersible polymer cementitious waterproof coating, characterized in that: The raw materials include liquid component A and powder component B. By mass parts, liquid component A includes: 85-95 parts of modified polymer emulsion, 0.1-1 parts of defoamer I, 0.05-0.1 parts of preservative, 5-15 parts of water, 0.1-0.5 parts of wetting agent, and 0.5-1 parts of silane coupling agent. The powder component B includes: 60-100 parts cement, 10-20 parts heavy calcium carbonate, 30-80 parts quartz powder, 0.1-1 parts highly dispersible water-reducing agent, and 0.1-1 parts defoamer II; The modified polymer emulsion comprises a composite emulsifier, a mixture of unsaturated acids, a mixture of monomers, an initiator, and water, wherein the mixture of monomers comprises butyl acrylate and tripropylene phosphite or their homologues; The mass ratio of liquid component A to powder component B is 1:1 to 2; The structural formula of the tripropylene phosphite or its homologue is: Where a = 1; b = 1; c = 1, R1, R2, and R3 are all CH3 or a = 2; b = 2; c = 2, R1, R2, and R3 are all H.

2. The highly dispersed polymer cementitious waterproof coating according to claim 1, characterized in that: The modified polymer emulsion comprises, by mass parts, 1.5 to 3 parts of composite emulsifier, 1.5 to 3 parts of mixed unsaturated acid, 35 to 40 parts of butyl acrylate, 12 to 18 parts of tripropylene phosphite or its homologue, 0.5 to 1 part of initiator, and 50 to 60 parts of water.

3. The highly dispersed polymer cementitious waterproof coating according to claim 1, characterized in that: The composite emulsifier includes a nonionic emulsifier and anionic emulsifier, and the mass ratio of the nonionic emulsifier to the anionic emulsifier is 1:0.5 to 1. The nonionic emulsifier is OP-10 or OP-15, and the anionic emulsifier is sodium dodecyl sulfate; The mixed unsaturated acid includes acrylic acid and methacrylic acid, wherein the mass ratio of acrylic acid to methacrylic acid is 1:0.5 to 1; The initiator is ammonium persulfate or potassium persulfate.

4. The highly dispersed polymer cementitious waterproof coating according to claim 3, characterized in that: The method for preparing the modified polymer emulsion includes the following steps: S1. Mix the first part of composite emulsifier, mixed unsaturated acid, first part of water and first part of mixed monomer, heat to 45-50℃ and stir evenly to obtain emulsion prepreg; S2. Mix the second part of the composite emulsifier, the second part of the water, the first part of the initiator and the second part of the mixed monomer, heat to 45-50℃ and stir evenly to obtain the seed emulsion; S3. Mix the second part of the initiator, seed emulsion and emulsion prepreg, heat to 60-90°C and stir evenly to obtain the modified polymer emulsion; The first part of the composite emulsifier accounts for 75% to 86% of the total composite emulsifier, and the second part of the composite emulsifier accounts for 14% to 25% of the total composite emulsifier; The first part of the mixed monomers accounts for 75% to 86% of the total mixed monomers, and the second part of the mixed monomers accounts for 14% to 25% of the total mixed monomers; The first part of the initiator accounts for 75% to 86% of the total initiator, and the second part of the initiator accounts for 14% to 25% of the total initiator.

5. The highly dispersed polymer cementitious waterproof coating according to claim 1, characterized in that: The defoamer I is one or more of polymethylphenylsiloxane and polydimethylsiloxane; The preservative is one or more selected from 2-ethyl-4-isothiazolinone, 2-octyl-4-isothiazolinone, and octadecyl dimethyl benzyl ammonium bromide; The wetting agent is sodium tripolyphosphate; The silane coupling agent is one or more of KH560 and KH570; The cement is ordinary Portland cement; The heavy calcium carbonate is one or more of 800 mesh calcium carbonate and 1250 mesh calcium carbonate; The defoamer II is one or more of polypropylene glycol fatty acid ester, dodecyl polyoxyethylene ether, or nonylphenol polyoxyethylene ether; The highly dispersed water-reducing agent includes polyether macromonomers, oxidants, reducing agents, chain transfer agents, acrylic acid, and functional monomers.

6. The highly dispersed polymer cementitious waterproof coating according to claim 5, characterized in that: By weight, the highly dispersible water-reducing agent comprises 100 parts of polyether macromonomer, 0.5-3 parts of oxidant, 0.5-3 parts of reducing agent, 0.5-1.5 parts of chain transfer agent, 8-15 parts of acrylic acid, and 0.5-2 parts of functional monomer; The polyether macromonomer is ethylene glycol monovinyl polyethylene glycol ether or 4-hydroxybutylvinyl polyoxyethylene ether.

7. The highly dispersed polymer cementitious waterproof coating according to claim 6, characterized in that: The structural formula of the functional unit is: Where a=0; b=0; c=0; d=0; e=0; R1 and R2 are both H.

8. The highly dispersed polymer cementitious waterproof coating according to any one of claims 5 to 7, characterized in that: The preparation method of the highly dispersed water-reducing agent is as follows: the polyether macromonomer is added to the reaction vessel and mixed with water. After stirring evenly, the oxidant is added, and then solution A and solution B are added dropwise respectively. The reaction is carried out at room temperature for 50-70 minutes. After the reaction is completed, the temperature is kept for 30-60 minutes, and the pH is adjusted to 6-7 by adding alkali solution to obtain the highly dispersed water-reducing agent. Solution A is a mixed solution of the reducing agent and the chain transfer agent, and solution B is a mixed solution of the acrylic acid and the functional monomer.

9. The method for preparing the highly dispersed polymer cementitious waterproof coating according to any one of claims 1 to 8, characterized in that: Includes the following steps: (1) Preparation of liquid component A: Add water, defoamer I and modified polymer emulsion to a container, adjust the speed to 700-1100 rpm, and stir for 2-3 min; Reduce the speed to 300-500 rpm, add the second part of defoamer I, silane coupling agent and wetting agent to the container, and continue stirring for 5-10 minutes; Add preservatives to the container and stir for 30-40 minutes to obtain liquid component A; (2) Preparation of powder component B: Cement, heavy calcium carbonate and quartz powder are ground and then dispersed and mixed with high dispersible water-reducing agent and defoamer II to obtain powder component B; (3) Mix the liquid component A and the powder component B in a certain proportion to obtain the highly dispersed polymer cement waterproof coating.

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