Waterproof anti-cracking JS coating, emulsion for JS coating and preparation method of emulsion

Abstract

The invention discloses a waterproof anti-cracking JS coating, an emulsion for the JS coating and a preparation method of the emulsion, and belongs to the field of waterproof coatings. The emulsion for the waterproof and anti-cracking JS coating comprises deionized water, n-butyl acrylate, styrene, 2-ethylhexyl acrylate, acrylamide, 1-2 parts of 2-hydroxyethyl acrylate, methacrylic acid, a functional aid, a defoaming agent, an emulsifier, a bactericide, an initiator, an oxidant, a reducing agent, a buffering agent and a pH regulator. According to the emulsion for the waterproof and anti-cracking JS coating, the acrylate monomer and the styrene monomer are matched for use, so that the glass-transition temperature of the emulsion for the waterproof and anti-cracking JS coating is between-30 DEG C and-20 DEG C, and flexibility can be provided for the waterproof and anti-cracking JS coating containing the emulsion; the cracking risk caused by cement shrinkage in the drying and film forming process of the waterproof anti-cracking JS coating is reduced, so that the waterproof anti-cracking JS coating can play a waterproof role for a long time.

Description

Technical Field

[0001] The invention relates to the technical field of waterproof coatings, and in particular to a waterproof and crack-resistant JS coating, an emulsion for the JS coating, and a method for preparing the emulsion. Background Art

[0002] The development of waterproof coatings has gone through several stages. In recent years, with the acceleration of urbanization, the scale and complexity of buildings have continued to increase, and the requirements for waterproof quality and environmental protection of waterproof coatings have also increased. Traditional waterproof materials such as asphalt felt have deficiencies in flexibility, weather resistance, construction convenience and environmental protection, and cannot meet the diverse waterproofing needs of modern buildings, thus promoting the development of new waterproof materials such as JS waterproof coatings. However, the existing JS waterproof coatings are used for the corners of the wall and the parts that require thick coatings to resist cracking. There is a risk of cracking during the drying and film-forming process of the JS waterproof coating, and the building will still leak.

[0003] It can be seen that the existing technology still needs to be improved and enhanced. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a waterproof and crack-resistant JS coating, an emulsion for JS coating and a method for preparing the emulsion, aiming to solve the problem that the existing JS coating is prone to cracking during the drying and film-forming process, and the problem that water leakage in buildings still occurs.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A waterproof and crack-resistant JS coating emulsion comprises the following components in parts by weight:

[0007] 115-123 parts of deionized water, 59-73 parts of n-butyl acrylate, 24-27 parts of styrene, 0-10 parts of 2-ethylhexyl acrylate, 1-2 parts of acrylamide, 1-2 parts of 2-hydroxyethyl acrylate, 0-1 part of methacrylic acid, 0.5-2 parts of functional additives, 0.2-1.5 parts of defoaming agent, 1-2 parts of emulsifier, 0.5-0.8 parts of bactericide, 0.3-0.5 parts of initiator, 0.3-0.6 parts of oxidant, 0.3-0.6 parts of reducing agent, 0.2-0.5 parts of buffer, and 0.1-0.3 parts of pH adjuster.

[0008] Optionally, the emulsifier includes an anionic emulsifier and a nonionic emulsifier, and the weight ratio of the anionic emulsifier to the nonionic emulsifier is (2-3):1.

[0009] Optionally, the anionic emulsifier includes at least one of ethoxylated alkyl sulfate sodium salt, alkyl diphenyl ether disulfonic acid sodium salt, and alkyl polyoxyethylene ether sulfate sodium salt.

[0010] Optionally, the nonionic emulsifier includes 40E0 isomeric tridecyl polyoxyethylene ether.

[0011] Optionally, the functional auxiliary agent includes at least one of potassium aluminum sulfate dodecahydrate, sodium gluconate, and sodium pyrophosphate.

[0012] Optionally, the defoamer comprises a mineral oil defoamer.

[0013] Optionally, the initiator includes at least one of potassium persulfate and sodium persulfate.

[0014] Optionally, the oxidizing agent includes tert-butyl hydroperoxide; and the reducing agent includes sodium metabisulfite.

[0015] The present invention also provides a method for preparing the waterproof and anti-cracking JS coating emulsion, comprising the following steps:

[0016] S001. Adding a buffer and deionized water to a polymerization reactor to obtain a bottom feed solution;

[0017] S002. Add an emulsifier and deionized water, acrylamide, 2-hydroxyethyl acrylate, methacrylic acid, styrene, n-butyl acrylate, 2-ethylhexyl acrylate to a pre-emulsification tank at room temperature and pressure, and stir to obtain a pre-emulsion;

[0018] S003. Add an initiator and deionized water to the initiator tank at room temperature and pressure, and stir until completely dissolved to obtain an initiator solution A;

[0019] S004. Add an initiator and deionized water to the initiator tank at room temperature and pressure, and stir until completely dissolved to obtain an initiator solution B;

[0020] S005. Add oxidant and deionized water to the oxidant tank at room temperature and pressure, and stir until completely dissolved to obtain an oxidant solution:

[0021] S006. Add a reducing agent and deionized water to a reducing agent tank at room temperature and pressure, and stir until completely dissolved to obtain a reducing agent solution;

[0022] S007. The temperature in the polymerization kettle was raised to 90°C, the initiator solution A was initially added to the polymerization kettle, and then the pre-emulsion and all the initiator solution B were uniformly added dropwise to the polymerization kettle, the reaction temperature was 86-88°C, and after the addition was completed, the temperature was kept for another 60 minutes;

[0023] S008. When the temperature in the polymerization kettle is lowered to 79-81°C, an oxidant solution and a reducing agent solution are added dropwise to the polymerization kettle to treat the residual monomers;

[0024] S009. After the residual monomer treatment is completed, wait for the temperature in the polymerization kettle to drop below 45°C, add a pH adjuster to adjust the pH to 7-9, then add a defoaming agent, a functional additive and the remaining deionized water, stir for 0.5-1h, filter the material, and obtain an emulsion for waterproof and anti-cracking JS coating.

[0025] The present invention also provides a waterproof and crack-resistant JS coating, comprising a liquid material and a powder material; the weight ratio of the liquid material to the powder material is 1:2;

[0026] The liquid material comprises the following components in parts by weight:

[0027] 85-95 parts of the aforementioned waterproof and anti-cracking JS coating emulsion, 9-10 parts of deionized water, 0.3-0.5 parts of defoaming agent, and 0.1-0.3 parts of bactericide;

[0028] The powder comprises the following components in parts by weight:

[0029] 45-55 parts of Portland cement, 30-40 parts of quartz sand, and 12-16 parts of heavy calcium carbonate.

[0030] Beneficial effects:

[0031] The invention provides an emulsion for waterproof and crack-resistant JS coatings. By using an acrylic ester monomer and a styrene monomer in combination, the glass transition temperature of the emulsion for waterproof and crack-resistant JS coatings is between -30°C and -20°C, flexibility can be provided for the waterproof and crack-resistant JS coatings containing the emulsion, the cracking risk caused by cement shrinkage during the drying and film-forming process of the waterproof and crack-resistant JS coatings is reduced, and the waterproof and crack-resistant JS coatings can play a waterproof role for a long time.

[0032] The present invention also provides a method for preparing an emulsion for waterproof and crack-resistant JS coatings, which adopts a pre-emulsification dropwise polymerization method, has a mild reaction process, and is beneficial to controlling the quality of the emulsion and waterproof coating products.

[0033] The present invention also provides a waterproof and anti-cracking JS coating, which is configured using the waterproof and anti-cracking JS coating emulsion and can have excellent anti-cracking performance in application scenarios such as corners and thick coatings, and can play a waterproof and anti-cracking role for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention provides a flow chart of a method for preparing a waterproof and crack-resistant JS coating emulsion. DETAILED DESCRIPTION

[0035] The present invention provides a waterproof and crack-resistant JS coating, an emulsion for JS coating, and a preparation method of the emulsion. In order to make the purpose, technical scheme and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] A waterproof and crack-resistant JS coating emulsion comprises the following components in parts by weight:

[0037] 115-123 parts of deionized water, 59-73 parts of n-butyl acrylate, 0-10 parts of 2-ethylhexyl acrylate, 24-27 parts of styrene, 1-2 parts of acrylamide, 0-1 part of methacrylic acid, 1-2 parts of 2-hydroxyethyl acrylate, 0.5-2 parts of functional additives, 0.2-1.5 parts of defoaming agent, 1-2 parts of emulsifier, 0.5-0.8 parts of bactericide, 0.3-0.5 parts of initiator, 0.3-0.6 parts of oxidant, 0.3-0.6 parts of reducing agent, 0.2-0.5 parts of buffer, and 0.1-0.3 parts of pH adjuster.

[0038] In the above composition, 2-ethylhexyl acrylate and n-butyl acrylate are both soft monomers of acrylic esters. The molecular structure of the above acrylic ester monomers contains a long carbon chain. These long carbon chains have good flexibility. After polymerization to form a polymer emulsion, the material after the emulsion is formed into a film can be given good softness and elasticity, so that the waterproof coating can better adapt to the deformation of the base layer, and it is not easy to cause the waterproof layer to rupture due to the cracking of the base layer. Styrene is an aromatic monomer that can form a polymer segment with strong rigidity after polymerization. These segments can increase the hardness of the emulsion after film formation, so that the waterproof coating can better resist external physical pressure and wear. The joint use of soft and hard monomers can construct the main skeleton of the waterproof and crack-resistant JS coating emulsion, thereby facilitating further polymerization reactions in the subsequent step to obtain a waterproof and crack-resistant JS coating emulsion.

[0039] In the above composition, methacrylic acid and acrylamide are functional monomers. Methacrylic acid mainly plays a role in enhancing the adhesion of the coating and improving water resistance. The carboxyl group contained in the methacrylic acid molecule can react chemically with the active groups such as hydroxyl and amino groups on the surface of the base layer during the emulsion film formation process to form a chemical bond. At the same time, it can also produce physical adsorption with the surface of the base layer. Acrylamide mainly improves the strength and toughness of the coating. The amide group in the acrylamide molecule can participate in the polymerization reaction to form a polymer chain with higher strength. At the same time, these polymer chains can also interact through hydrogen bonds and other interactions to further enhance the intermolecular forces, so that the coating formed by the emulsion has good strength and toughness.

[0040] In the above composition, 2-hydroxyethyl acrylate helps to improve the film-forming properties of the emulsion. The molecular structure of 2-hydroxyethyl acrylate contains a long carbon chain, which gives the polymer good flexibility. When it participates in the polymerization reaction to form the polymer film of the emulsion, it can make the film maintain good elasticity under different temperatures and environmental conditions, forming a uniform and continuous film, avoiding film defects such as holes and cracks, and effectively preventing the cracking of the coating caused by temperature changes or slight deformation of the base layer, thereby ensuring the integrity and waterproof effect of the waterproof layer; while the functional additives mainly play a role in extending the curing time of the coating, improving the rheology of the coating, and refining the hydration products of cement in the waterproof and crack-resistant JS coating, so that the formed waterproof membrane structure is denser and reduces cracking.

[0041] The glass transition temperature (Tg) of the waterproof and crack-resistant JS coating emulsion provided by the present invention is between -30°C and -20°C. When the glass transition temperature of the waterproof and crack-resistant JS coating emulsion is within a suitable range, it can provide flexibility for the waterproof coating containing the emulsion, reduce the risk of cracking caused by cement shrinkage during the drying and film-forming process of the waterproof and crack-resistant JS coating, and enable the waterproof and crack-resistant JS coating to play a waterproof role for a long time. Specifically, when the glass transition temperature of the waterproof and crack-resistant JS coating emulsion is lower than -30°C, the flexibility of the macromolecular chain of the emulsion increases, which will greatly reduce the bonding strength of the waterproof and crack-resistant JS coating, and the hardness and wear resistance of the coating after the waterproof coating is film-formed will also deteriorate. When the glass transition temperature of the waterproof and crack-resistant JS coating emulsion is higher than -20°C, the rigidity of the prepared waterproof and crack-resistant JS coating will be large, while the flexibility and anti-cracking performance will deteriorate.

[0042] Optionally, the emulsifier includes anionic emulsifier and nonionic emulsifier. Among them, the anionic emulsifier can include at least one of ethoxylated alkyl sulfate sodium salt, alkyl diphenyl ether disulfonic acid sodium salt, and alkyl polyoxyethylene ether sulfate sodium salt. The alkyl diphenyl ether disulfonic acid sodium salt can be sodium dodecyl diphenyl ether disulfonate, which can still be used for emulsified polymer reactions at 80-120°C without losing surface activity. The alkyl polyoxyethylene ether sodium sulfate can copolymerize with styrene and acrylic monomers, which can improve the stability of the emulsion and improve the construction performance. The ethoxylated alkyl sulfate sodium salt has good emulsifying properties and can disperse the core part of the emulsion in the aqueous phase and keep it uniform and stable.

[0043] Optionally, the nonionic emulsifier includes isomeric tridecyl polyoxyethylene ether of 40E0. The isomeric tridecyl polyoxyethylene ether of 40E0 can form a stable emulsion between the aqueous phase and the oil phase to achieve emulsification and dispersion effects. In addition, the isomeric tridecyl polyoxyethylene ether of 40E0 does not contain sulfur, so that the waterproof and crack-resistant JS coating obtained by the configuration will not react with metal ions to cause discoloration.

[0044] Of the two emulsifiers, anionic emulsifier and nonionic emulsifier, the amount of anionic emulsifier should not be too much, otherwise the emulsion is more likely to experience stratification, precipitation and demulsification, and the water resistance of the emulsion will also decrease. In addition, when the emulsion is used in a waterproof coating, an excessive amount of anionic emulsifier will affect the bonding force between the waterproof coating and the substrate, causing the adhesion of the waterproof coating to the substrate to decrease. When the amount of nonionic emulsifier is too much, the water resistance of the waterproof coating will decrease. Preferably, the weight ratio of the anionic emulsifier to the nonionic emulsifier is (2 to 3): 1. When the amount ratio of the two emulsifiers is within the above range, the waterproof coating can maintain excellent water resistance and strong bonding force.

[0045] Optionally, the functional auxiliary agent includes at least one of potassium aluminum sulfate dodecahydrate, sodium gluconate, and sodium pyrophosphate.

[0046] Optionally, the buffer comprises sodium bicarbonate. The defoaming agent comprises a mineral oil defoaming agent.

[0047] Optionally, the initiator includes at least one of potassium persulfate and sodium persulfate.

[0048] Optionally, the oxidant includes tert-butyl hydroperoxide; the reducing agent includes sodium pyrosulfite. The oxidant and reducing agent are used to treat the residual monomers in the emulsion, improve the conversion efficiency of soft and hard monomers and functional monomers, eliminate irritating odors, reduce the odor of the coating, and improve the health of the construction workers while being environmentally friendly.

[0049] The present invention also provides a method for preparing the waterproof and anti-cracking JS coating emulsion, comprising the following steps:

[0050] S001. Add a buffer and 38 to 42 parts of deionized water to a polymerization reactor to obtain a bottom feed solution;

[0051] S002. Add an emulsifier and 23 to 28 parts of deionized water, acrylamide, 2-hydroxyethyl acrylate, methacrylic acid, styrene, n-butyl acrylate, 2-ethylhexyl acrylate to a pre-emulsification tank at room temperature and pressure, and stir to obtain a pre-emulsion;

[0052] S003. Add 0.05 to 0.1 parts of initiator and 2 to 3 parts of deionized water to the initiator tank at room temperature and pressure, and stir until completely dissolved to obtain an initiator solution A;

[0053] S004. Add 0.2 to 0.4 parts of initiator and 5 to 7 parts of deionized water to the initiator tank at room temperature and pressure, and stir until completely dissolved to obtain an initiator solution B;

[0054] S005. Add 0.3-0.6 parts of oxidant and 3-4 parts of deionized water to the oxidant tank at room temperature and pressure, and stir until completely dissolved to obtain an oxidant solution:

[0055] S006. Add 0.3 to 0.6 parts of reducing agent and 3 to 4 parts of deionized water to the reducing agent tank at room temperature and pressure, and stir until completely dissolved to obtain a reducing agent solution;

[0056] S007. The temperature in the polymerization kettle was raised to 90°C, the initiator solution A was initially added to the polymerization kettle, and then the pre-emulsion and all the initiator solution B were uniformly added dropwise to the polymerization kettle, the reaction temperature was 86-88°C, the addition was continued for 240min, and after the addition was completed, the temperature was kept at 86-88°C for another 60min. The insulation temperature was controlled at 86-88°C.

[0057] S008. When the temperature in the polymerization reactor is lowered to 79-81°C, an oxidant solution and a reducing agent solution are added dropwise to the polymerization reactor to treat the residual monomers;

[0058] S009. After the residual monomer treatment is completed, wait for the temperature in the polymerization kettle to drop below 45°C, add a pH adjuster to adjust the pH to 7-9, then add a defoaming agent, a functional additive and the remaining deionized water, stir for 0.5-1h, filter the material, and obtain an emulsion for waterproof and anti-cracking JS coating.

[0059] The preparation method provided by the present invention adopts a pre-emulsification dropwise polymerization method, and the reaction process is mild, which is beneficial to controlling the quality of the product.

[0060] The present invention also provides a waterproof and crack-resistant JS coating, comprising a liquid material and a powder material; the weight ratio of the liquid material to the powder material is 1:2;

[0061] The liquid material comprises the following components in parts by weight:

[0062] 85-95 parts of the aforementioned waterproof and anti-cracking JS coating emulsion, 9-10 parts of deionized water, 0.3-0.5 parts of defoaming agent, and 0.1-0.3 parts of bactericide;

[0063] The powder comprises the following components in parts by weight:

[0064] 45-55 parts of Portland cement, 30-40 parts of quartz sand, and 12-16 parts of heavy calcium carbonate.

[0065] The waterproof and anti-cracking JS coating provided by the present invention has excellent anti-cracking performance in application scenarios such as corners and thick coatings, and can play a waterproof and anti-cracking role for a long time.

[0066] By using two different fillers, quartz sand and heavy calcium, at the same time, and utilizing the characteristics of different filler sizes and shapes, the filler can fill more gaps in silicate cement, thereby effectively increasing the density of the powder, and improving the water-proof ability of the waterproof and crack-resistant JS coating. The present invention also strictly controls the weight ratio of the liquid material and the powder, while reducing the cost of the JS waterproof coating, it can also maintain the water-proof ability of the waterproof and crack-resistant JS coating at a better level, and the waterproof and crack-resistant JS coating has good film-forming properties, a high elongation at break of the coating, and is not easy to crack, so that the waterproof and crack-resistant JS coating can play a waterproof and crack-resistant role for a long time.

[0067] In order to further illustrate the waterproof and crack-resistant JS coating, the emulsion for JS coating and the preparation method of the emulsion of the present invention, the following examples and comparative examples are provided.

[0068] Example 1

[0069] The present embodiment provides an emulsion for waterproof and crack-resistant JS coating, which is composed of the following components in parts by weight: 116 parts of deionized water, 1 part of acrylamide, 2 parts of 2-hydroxyethyl acrylate, 0.35 parts of methacrylic acid, 27 parts of styrene, 59.6 parts of n-butyl acrylate, 10 parts of 2-ethylhexyl acrylate, 1.5 parts of emulsifier, 0.25 parts of sodium bicarbonate (buffer), 0.37 parts of potassium persulfate (initiator), 0.48 parts of tert-butyl hydroperoxide (oxidant), 0.44 parts of sodium pyrosulfite (reducing agent), 0.23 parts of pH adjuster, 1 part of sodium gluconate (functional additive), 0.3 parts of defoamer, and 0.6 parts of bactericide.

[0070] The emulsifier comprises 1.1 parts of anionic emulsifier and 0.4 parts of nonionic emulsifier, the anionic emulsifier is sodium dodecyl diphenyl ether disulfonate, and the nonionic emulsifier is 40E0 isomeric tridecyl polyoxyethylene ether.

[0071] This embodiment also provides a method for preparing a waterproof and crack-resistant JS coating emulsion, comprising the following steps:

[0072] S001. A buffer and 40 parts of deionized water were added to the polymerization reactor to obtain a bottom feed solution;

[0073] S002. At room temperature and pressure, an emulsifier and 25 parts of deionized water, acrylamide, 2-hydroxyethyl acrylate, methacrylic acid, styrene, n-butyl acrylate, 2-ethylhexyl acrylate were added to the pre-emulsification tank and stirred to obtain a pre-emulsion;

[0074] S003. 0.1 parts of initiator and 2.8 parts of deionized water were added to the initiator tank at room temperature and pressure, and stirred until completely dissolved to obtain an initiator solution A;

[0075] S004. 0.27 parts of initiator and 7 parts of deionized water were added to the initiator tank at room temperature and pressure, and stirred until completely dissolved to obtain an initiator solution B;

[0076] S005. Add 0.48 parts of oxidant and 3.4 parts of deionized water to the oxidant tank at room temperature and pressure, and stir until completely dissolved to obtain an oxidant solution:

[0077] S006. Add 0.44 parts of reducing agent and 3.2 parts of deionized water to the reducing agent tank at room temperature and pressure, and stir until completely dissolved to obtain a reducing agent solution;

[0078] S007. The temperature in the polymerization kettle was raised to 90°C, the initiator solution A was initially added to the polymerization kettle, and then the pre-emulsion and all the initiator solution B were uniformly added dropwise to the polymerization kettle, the reaction temperature was 86-88°C, the addition was continued for 240min, and after the addition was completed, the temperature was kept at 86-88°C for another 60min. The insulation temperature was controlled at 86-88°C.

[0079] S008. When the temperature in the polymerization kettle is lowered to 79-81°C, an oxidant solution and a reducing agent solution are added dropwise to the polymerization kettle to treat the residual monomers;

[0080] S009. After the residual monomer treatment is completed, wait for the temperature in the polymerization kettle to drop below 45°C, add a pH adjuster to adjust the pH to 7-9, then add a defoaming agent, a functional additive and the remaining deionized water, stir for 0.5-1h, filter the material, and obtain an emulsion for waterproof and anti-cracking JS coating.

[0081] Example 2

[0082] The present embodiment provides an emulsion for waterproof and crack-resistant JS coating, which is composed of the following components in parts by weight: 120 parts of deionized water, 1.2 parts of acrylamide, 2 parts of 2-hydroxyethyl acrylate, 0.35 parts of methacrylic acid, 24 parts of styrene, 72.4 parts of n-butyl acrylate, 0 parts of 2-ethylhexyl acrylate, 1.1 parts of emulsifier, 0.25 parts of sodium bicarbonate (buffer), 0.37 parts of potassium persulfate (initiator), 0.48 parts of tert-butyl hydroperoxide (oxidant), 0.44 parts of sodium pyrosulfite (reducing agent), 0.17 parts of pH adjuster, 1 part of sodium pyrophosphate (functional additive), 0.2 parts of defoamer, and 0.55 parts of bactericide.

[0083] The emulsifier comprises 0.7 parts of anionic emulsifier and 0.3 parts of nonionic emulsifier, the anionic emulsifier is sodium dodecyl diphenyl ether disulfonate, and the nonionic emulsifier is 40E0 isomeric tridecyl polyoxyethylene ether.

[0084] This embodiment also provides a method for preparing a waterproof and crack-resistant JS coating emulsion, which is the same as the preparation method provided in Example 1.

[0085] Example 3

[0086] The present embodiment provides an emulsion for waterproof and crack-resistant JS coating, which is composed of the following components in parts by weight: 120 parts of deionized water, 1.4 parts of acrylamide, 2 parts of 2-hydroxyethyl acrylate, 0.25 parts of methacrylic acid, 24 parts of styrene, 72.3 parts of n-butyl acrylate, 0 parts of 2-ethylhexyl acrylate, 1.8 parts of emulsifier, 0.25 parts of sodium bicarbonate (buffer), 0.37 parts of potassium persulfate (initiator), 0.48 parts of tert-butyl hydroperoxide (oxidant), 0.44 parts of sodium pyrosulfite (reducing agent), 0.18 parts of pH regulator, 1 part of potassium aluminum sulfate dodecahydrate (functional additive), 0.2 parts of defoamer, and 0.55 parts of bactericide.

[0087] The emulsifier comprises 1.1 parts of anionic emulsifier and 0.4 parts of nonionic emulsifier, the anionic emulsifier is sodium dodecyl diphenyl ether disulfonate, and the nonionic emulsifier is 40E0 isomeric tridecyl polyoxyethylene ether.

[0088] This embodiment also provides a method for preparing a waterproof and crack-resistant JS coating emulsion, which is the same as the preparation method provided in Example 1.

[0089] Comparative Example 1

[0090] This comparative example provides a JS coating emulsion, which is composed of the following components by weight: 120 parts of deionized water, 1.2 parts of acrylamide, 2 parts of 2-hydroxyethyl acrylate, 0.35 parts of methacrylic acid, 35 parts of styrene, 61.45 parts of n-butyl acrylate, 1.8 parts of emulsifier, 0.25 parts of sodium bicarbonate, 0.37 parts of potassium persulfate, 0.48 parts of tert-butyl hydroperoxide, 0.44 parts of sodium pyrosulfite, 0.23 parts of pH regulator, 1 part of sodium pyrophosphate, 0.2 parts of defoamer, and 0.6 parts of bactericide.

[0091] The emulsifier includes a reactive anionic emulsifier and a nonionic emulsifier. The anionic emulsifier is 1.1 parts of sodium dodecyl diphenyl ether disulfonate, and the nonionic emulsifier is 0.4 parts of 40E0 isomeric tridecyl polyoxyethylene ether.

[0092] This comparative example also provides a method for preparing the JS coating emulsion, which is the same as the preparation method provided in Example 1.

[0093] Comparative Example 2

[0094] This comparative example provides a JS coating emulsion, which is composed of the following components by weight: 120 parts of deionized water, 1.2 parts of acrylamide, 2 parts of 2-hydroxyethyl acrylate, 0.35 parts of methacrylic acid, 15 parts of styrene, 81.45 parts of n-butyl acrylate, 1.8 parts of emulsifier, 0.25 parts of sodium bicarbonate, 0.37 parts of potassium persulfate, 0.48 parts of tert-butyl hydroperoxide, 0.44 parts of sodium pyrosulfite, 0.23 parts of pH regulator, 1 part of sodium pyrophosphate, 0.2 parts of defoamer, and 0.6 parts of bactericide.

[0095] The emulsifier includes a reactive anionic emulsifier and a nonionic emulsifier. The anionic emulsifier is 1.1 parts of sodium dodecyl diphenyl ether disulfonate, and the nonionic emulsifier is 0.4 parts of 40E0 isomeric tridecyl polyoxyethylene ether.

[0096] This comparative example also provides a method for preparing the JS coating emulsion, which is the same as the preparation method provided in Example 1.

[0097] The waterproof and anti-cracking emulsions prepared in Examples 1 to 3, Comparative Example 1 and Comparative Example 2 are used to prepare waterproof and anti-cracking JS coatings or JS coatings. The formula of the waterproof and anti-cracking JS coatings or JS coatings is as follows:

[0098] Liquid material: 90 parts of emulsion, 9.4 parts of deionized water, 0.4 parts of defoamer, and 0.2 parts of bactericide.

[0099] Powder: 50 parts of 42.5PO ordinary Portland cement, 35 parts of 70-110 mesh quartz sand, and 15 parts of 200 mesh heavy calcium.

[0100] The ratio of liquid to powder is 1:2.

[0101] Test methods for each performance indicator

[0102] With reference to the standard "GB / T 23445-2009 Polymer Cement Waterproof Coating", the waterproof and anti-cracking JS coating or JS coating obtained by the above configuration was subjected to tensile strength test, elongation at break test, impermeability test and bonding strength test.

[0103] Determination method for cracking resistance at yin and yang corners: In a constant temperature and humidity laboratory, apply the waterproof and crack-resistant JS coating or JS coating obtained by the above configuration on the concrete slab substrate with yin and yang corners. After curing for 7 days, observe the cracking of the yin and yang corners and give a score based on the experimental results. The score range is 0-5 points, with 5 being good.

[0104] Determination method for thick coating cracking resistance: In a constant temperature and humidity laboratory, the waterproof and crack-resistant JS coating or JS coating obtained by the above configuration is applied on a concrete slab substrate with a 3mm thick steel bar. After curing for 7 days, the thick coating cracking is observed and scored based on the experimental results. The score range is 0-5 points, with 5 being good.

[0105] Table 1:

[0106] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Solid content% 55 55 55 55 55 PH 7.5 7.8 7.8 7.7 7.9 Viscosity 3#30r / cps 522 605 491 360 500 Glass transition temperature (TG) -27.5℃ -28.77℃ -28.64℃ -15.4℃ -38.7℃

[0107] Table 2:

[0108]

[0109] The theoretical Tg of the emulsion for waterproof and anti-cracking JS coating prepared in Examples 1-3 is controlled between -30°C and -20°C. It can be seen from the test results in the above table that the waterproof and anti-cracking JS coating prepared in Examples 1-3 has high tensile strength and good elongation at break. Both anti-cracking test scores are 4 points, which has an improved effect on resisting cracking at corners and thick coating cracking.

[0110] The theoretical Tg of the JS coating emulsion in Comparative Example 1 is -15.4°C. If the theoretical Tg is too high, it will lead to insufficient flexibility. As shown in the test results of Table 2 above, the waterproof coating prepared therefrom has poor anti-cracking effect, with two anti-cracking test scores of only 2 points, and it is water-impermeable and does not pass.

[0111] The theoretical Tg of the JS coating emulsion in Comparative Example 3 is -38.7°C. If the theoretical Tg is too low, its strength will be insufficient. As shown in the test results in Table 2 above, the tensile strength and bonding strength of the waterproof coating prepared therefrom are lower than the standard requirements.

[0112] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all these changes or substitutions should fall within the protection scope of the claims attached to the present invention.

Claims

1. A waterproof and crack-resistant JS coating emulsion, characterized in that: The invention comprises the following components in parts by weight: 115-123 parts of deionized water, 59-73 parts of n-butyl acrylate, 24-27 parts of styrene, 0-10 parts of 2-ethylhexyl acrylate, 1-2 parts of acrylamide, 1-2 parts of 2-hydroxyethyl acrylate, 0-1 part of methacrylic acid, 0.5-2 parts of functional additives, 0.2-1.5 parts of defoaming agents, 1-2 parts of emulsifiers, 0.5-0.8 parts of bactericides, 0.3-0.5 parts of initiators, 0.3-0.6 parts of oxidants, 0.3-0.6 parts of reducing agents, 0.2-0.5 parts of buffers and 0.1-0.3 parts of pH regulators.

2. The waterproof and anti-cracking JS coating emulsion according to claim 1, characterized in that: The emulsifier includes anionic emulsifier and nonionic emulsifier; The anionic emulsifier includes at least one of ethoxylated alkyl sulfate sodium salt, alkyl diphenyl ether disulfonic acid sodium salt, and alkyl polyoxyethylene ether sulfate sodium salt; The nonionic emulsifier includes 40E0 isomeric tridecyl polyoxyethylene ether.

3. The waterproof and crack-resistant JS coating emulsion according to claim 2, characterized in that: The weight ratio of the anionic emulsifier to the nonionic emulsifier is (2-3):

1.

4. The waterproof and anti-cracking JS coating emulsion according to claim 1, characterized in that: The functional auxiliary agent includes at least one of potassium aluminum sulfate dodecahydrate, sodium gluconate, and sodium pyrophosphate.

5. The waterproof and anti-cracking JS coating emulsion according to claim 1, characterized in that: The defoaming agent includes a mineral oil defoaming agent.

6. The waterproof and crack-resistant JS coating emulsion according to claim 1, characterized in that: The initiator includes at least one of potassium persulfate and sodium persulfate.

7. The waterproof and crack-resistant JS coating emulsion according to claim 1, characterized in that: The oxidizing agent includes tert-butyl hydroperoxide; the reducing agent includes sodium metabisulfite.

8. A method for preparing the waterproof and anti-cracking JS coating emulsion according to any one of claims 1 to 8, characterized in that: The following steps are involved: S001. Adding a buffer and deionized water to a polymerization reactor to obtain a bottom feed solution; S002. Add an emulsifier and deionized water, acrylamide, 2-hydroxyethyl acrylate, methacrylic acid, styrene, n-butyl acrylate, 2-ethylhexyl acrylate to a pre-emulsification tank at room temperature and pressure, and stir to obtain a pre-emulsion; S003. Add an initiator and deionized water to the initiator tank at room temperature and pressure, and stir until completely dissolved to obtain an initiator solution A; S004. Add an initiator and deionized water to the initiator tank at room temperature and pressure, and stir until completely dissolved to obtain an initiator solution B; S005. Add oxidant and deionized water to the oxidant tank at room temperature and pressure, and stir until completely dissolved to obtain an oxidant solution: S006. Add a reducing agent and deionized water to a reducing agent tank at room temperature and pressure, and stir until completely dissolved to obtain a reducing agent solution; S007. The temperature in the polymerization kettle was raised to 90°C, the initiator solution A was initially added to the polymerization kettle, and then the pre-emulsion and all the initiator solution B were uniformly added dropwise to the polymerization kettle, the reaction temperature was 86-88°C, and after the addition was completed, the temperature was kept for another 60 minutes; S008. When the temperature in the polymerization kettle is lowered to 79-81°C, an oxidant solution and a reducing agent solution are added dropwise to the polymerization kettle to treat the residual monomers; S009. After the residual monomer treatment is completed, wait for the temperature in the polymerization kettle to drop below 45°C, add a pH adjuster to adjust the pH to 7-9, then add a defoamer, a functional additive and deionized water, stir for 0.5-1h, filter the material, and obtain a waterproof and anti-cracking JS coating emulsion.

9. A waterproof and crack-resistant JS coating, characterized in that: It comprises liquid material and powder material; the weight ratio of the liquid material to the powder material is 1:2; The liquid material comprises the following components in parts by weight: 85-95 parts of the waterproof and anti-cracking JS coating emulsion according to any one of claims 1 to 8, 9-10 parts of deionized water, 0.3-0.5 parts of a defoaming agent, and 0.1-0.3 parts of a bactericide; The powder comprises the following components in parts by weight: 45-55 parts of Portland cement, 30-40 parts of quartz sand, and 12-16 parts of heavy calcium carbonate.

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