High-water-resistance, high-transparency and high-weather-resistance pure acrylic waterproof emulsion with multi-layer structure and preparation method of pure acrylic waterproof emulsion

Abstract

The invention aims to provide a high-water-resistance, high-transparency and high-weather-resistance pure acrylic waterproof emulsion with a multi-layer structure and a preparation method of the pure acrylic waterproof emulsion. The pure acrylic waterproof emulsion is applied to the building fields of exterior wall waterproofing, ceramic tile waterproofing and the like. The waterproof emulsion prepared by the invention is mainly characterized in that a sectional reaction mechanism is adopted, and the prepared emulsion particles have a hard-soft-hard multi-layer core-shell structure. According to the structure, the water resistance, weather resistance and pollution resistance of the emulsion after film forming can be improved, and the emulsion has certain formaldehyde absorption capacity. The formula main body is an acrylic emulsion formula, a functional monomer with a special functional group is used, the crosslinking degree of the polymer is improved, the reactive surfactant is selected in the emulsifier and can react with carbon-carbon double bonds, and the water resistance of the product is improved by both the reactive surfactant and the emulsifier. In addition, the preparation method further adopts the synergistic effect of ultrasonic waves and stirring, the pure acrylic waterproof emulsion with fine particle size and high transparency is finally obtained, and the use requirements for durability and attractiveness are met.

Description

Technical Field

[0001] The invention belongs to the technical field of waterproof coatings, and specifically relates to a highly water-resistant, highly transparent, and highly weather-resistant multi-layered pure acrylic waterproof emulsion and a preparation method thereof, which is suitable for construction fields such as exterior wall waterproofing and tile waterproofing. Background Art

[0002] In the current transparent waterproof adhesive system, styrene acrylic waterproof emulsion and pure acrylic waterproof emulsion occupy an important position due to their respective characteristics. Styrene acrylic emulsion has some disadvantages, such as yellowing under ultraviolet light, affecting appearance and durability, and its water whitening resistance may not be sufficient to meet high standards of waterproofing requirements. Pure acrylic waterproof emulsion can provide excellent waterproof performance while forming a film with high transparency, becoming an important choice in the field of waterproof coatings. However, unmodified pure acrylic waterproof emulsion still has problems such as insufficient performance stability in high or low temperature environments, and water whitening phenomenon caused by long-term contact with water.

[0003] In recent years, the construction field has higher requirements for the waterproof performance and special functions of pure acrylic emulsion. Under this background, it is particularly important to develop a new type of pure acrylic waterproof emulsion with high water resistance, high transparency and high weather resistance multi-layer structure. The pure acrylic waterproof emulsion prepared by the present invention can not only provide excellent weather resistance and waterproof performance, but also maintain high transparency of the coating film, and at the same time has a certain formaldehyde absorption capacity, meeting the dual requirements of modern architecture for beauty and practicality.

[0004] The prior art discloses CN111675790A 20200918 freeze-thaw resistant polymer emulsion and its preparation method: The present invention belongs to the field of emulsion polymerization technology, and specifically relates to a freeze-thaw resistant polymer emulsion and its preparation method. The raw materials are composed of deionized water, reactive emulsifier, anionic emulsifier, nonionic emulsifier, initiator, pH buffer, hard monomer, soft monomer, water-soluble monomer, oxidant, reductant, pH regulator and bactericide. The present invention uses reactive emulsifier, anionic emulsifier and nonionic emulsifier as three emulsifiers, and uses "core-shell emulsion polymerization" technology to make the latex particles have a thin, non-sticky "hard shell". The prepared polymer emulsion can withstand long-term and multiple freeze-thaw cycles in the actual environment and will not increase the use of VOC. CN104530302A 20150422 A high silicon content silica sol / polyacrylate emulsion and its preparation method: The present invention discloses a high silicon content silica sol / polyacrylate emulsion and its preparation method. The method uses water-soluble macromolecules to physically modify silica sol, and in-situ polymerizes the modified silica sol with acrylate monomers to prepare silica sol / polyacrylate emulsion. In terms of mass fractions, the formula composition of the raw materials is: 50-70 parts of deionized water, 5-30 parts of silica sol, 0.01-0.5 parts of water-soluble macromolecules, 20-53 parts of acrylate monomers, 1-5 parts of methacrylic acid or acrylic acid, 1-5 parts of emulsifiers, 0.1-0.5 parts of initiators, and 0.1-0.5 parts of pH buffers; in terms of SiO2, the silicon content in the emulsion accounts for 5-30% of the total solid content; the particle size of the latex particles is 60-100nm; the carboxyl and hydroxyl groups on the polymer molecular chain of the present invention and the hydroxyl groups on the surface of the SiO2 particles can undergo esterification crosslinking, so that the hardness of the film reaches more than 5H, and has outstanding water resistance and weather resistance. None of the above can simultaneously achieve the effects of high water resistance, high transparency, high weather resistance, and waterproofness.

[0005] Therefore, the present invention focuses on developing a pure acrylic waterproof emulsion with a highly water-resistant, highly transparent and highly weather-resistant multi-layer structure. The pure acrylic waterproof emulsion is reacted with other additives to form a pure acrylic waterproof emulsion. After curing, the emulsion can form a waterproof film with certain weather resistance, water resistance, extensibility and environmental protection. It can form a waterproof barrier to prevent moisture penetration and protect building structures such as exterior walls and tiles. Summary of the invention

[0006] The present invention aims to provide a pure acrylic waterproof emulsion with a highly water-resistant, highly transparent and highly weather-resistant multilayer structure and a preparation method thereof, and to prepare emulsion particles with a hard-soft-hard structure, so as to address the deficiencies of existing pure acrylic waterproof emulsions in terms of weather resistance and water whitening resistance, and enhance the functionality of pure acrylic emulsions. Through the technical solution of the present invention, the prepared pure acrylic waterproof emulsion has a finer particle size and excellent transparency, ensuring a significant improvement in waterproof performance, weather resistance, water whitening resistance and transparency, and giving the emulsion the ability to absorb formaldehyde. To achieve the above purpose, the present invention is implemented through the following technical solutions:

[0007] In one aspect, the present invention provides a highly water-resistant, highly transparent, and highly weather-resistant multi-layered pure acrylic waterproof emulsion, including main components and proportions:

[0008] 140-330 parts of hard monomer, preferably 180-250 parts,

[0009] Soft monomer 90-180 parts, preferably 120-150 parts,

[0010] Functional monomer A 6-15 parts, preferably 9-13 parts,

[0011] Functional monomer B 1-6 parts, preferably 2-4 parts, functional monomer C 1-6 parts, preferably 2-4 parts, functional monomer D 1-6 parts, preferably 2-4 parts, anionic surfactant 5-30 parts, preferably 15-20 parts,

[0012] Deionized water A 100-200 parts, preferably 130-170 parts,

[0013] Reactive surfactant 0.1-5 parts, preferably 0.5-3.5 parts,

[0014] Deionized water B 150-350 parts, preferably, 230-280 parts,

[0015] 2-14 parts of nonionic surfactant, preferably 5-11 parts,

[0016] Initiator 1-4 parts, preferably 1.5-3 parts,

[0017] Oxidant 0.1-3 parts, preferably 0.5-2 parts,

[0018] Reducing agent 0.1-3 parts, preferably 0.5-2 parts,

[0019] pH adjuster 2-6 parts, preferably 3-5 parts,

[0020] 10-20 parts of fungicide, preferably 12-16 parts,

[0021] Deionized water C50-150 parts, preferably 80-120 parts,

[0022] The solid content is adjusted to 30-80 parts of water, preferably 45-65 parts.

[0023] The main components and proportions of the pure acrylic waterproof emulsion described in the present invention are:

[0024] The hard monomer types include, but are not limited to, one or more monomers such as methyl methacrylate and butyl methacrylate;

[0025] The soft monomer types include but are not limited to one or more monomers such as isooctyl acrylate, ethyl acrylate, and butyl acrylate;

[0026] The types of the functional monomers A / C / D include, but are not limited to, one or more of acrylic acid, methacrylic acid, allyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, acrylamide, acrylonitrile, hydroxypropyl acrylate, hydroxypropyl methacrylate, acrylic acid itaconic acid and the like;

[0027] The functional monomer B includes, but is not limited to, one or more of vinyl triethoxysilane A151, vinyl trimethoxysilane A171, vinyl tri(β-methoxyethoxy)silane A172, γ-aminopropyl triethoxysilane KH-550, γ-aminopropyl trimethoxysilane KH560, and γ-methacryloxypropyl trimethoxysilane KH570;

[0028] The types of anionic surfactants include, but are not limited to, one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, alkyl sulfonates, potassium lauryl phosphate, fatty acid soaps and the like;

[0029] The types of nonionic surfactants include, but are not limited to, one or more of fatty alcohol polyoxyethylene ethers, allyl propylene oxide ethers, fatty acid polyoxyethylene esters, polyoxyethylene-polyoxypropylene copolymers, alkyl polyglucosides, saturated fatty acid glycerides, polysorbates, and the like;

[0030] The materials in the reaction kettle of the pure acrylic waterproof emulsion of the present invention are as follows:

[0031] The types of reactive surfactants include, but are not limited to, one or more of sodium p-styrene sulfonate, sodium vinyl sulfonate, monopolyethylene glycol acrylate, acrylate-terminated waterborne polyurethane, AMPS (2-acrylamide-2-methylpropane sulfonic acid), COPS (methoxyethyl acrylate phosphate) and the like;

[0032] The auxiliary agent composition of the pure acrylic waterproof emulsion described in the present invention is:

[0033] The initiator types include, but are not limited to, one or more of potassium persulfate, sodium persulfate, ammonium persulfate, benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile and the like;

[0034] The types of pH adjusters include, but are not limited to, one or more of ammonia water, sodium hydroxide, sodium bicarbonate, sodium dihydrogen phosphate and the like;

[0035] The oxidant type includes but is not limited to one or more reagents such as tert-butyl hydroperoxide and diisopropylbenzene hydroperoxide;

[0036] The reducing agent includes, but is not limited to, one or more of sodium sulfite, sodium bisulfite, sodium pyrosulfite, organic sulfinic acid sodium salt, sodium formaldehyde sulfoxylate and the like;

[0037] The types of bactericides include, but are not limited to, one or more of agents such as kasone, phenoxyethanol, parabens, bropol, isothiazolinone, diphenylisothiazolinone, sodium benzoate, potassium sorbate, and hydrogen peroxide;

[0038] In another aspect, the present invention provides a method for preparing a highly water-resistant, highly transparent and highly weather-resistant multi-layered pure acrylic waterproof emulsion, comprising the following steps:

[0039] S1: At a certain temperature in the reactor, a reactive surfactant and deionized water B are added into the reactor and dispersed evenly to prepare a reactor bottom liquid;

[0040] S2: at a certain temperature in the emulsification kettle, part of the hard monomer, functional monomer C, primer initiator, anionic surfactant, and deionized water A are added into the emulsification kettle, and dispersed evenly under the synergistic effect of the ultrasonic device and the stirring device, and the core layer seed emulsion is obtained after heat preservation;

[0041] S3: at a certain temperature in the reactor, the soft monomer, the functional monomer A and the functional monomer B are added into the emulsification reactor, and are evenly dispersed under the synergistic effect of the ultrasonic device and the stirring device to obtain a pre-emulsified liquid;

[0042] S4: Adding a pH regulator into the reactor to adjust the pH of the materials in the reactor to be weakly acidic;

[0043] S5: After the primer initiator is stirred evenly, the pre-emulsion and the initiator are added dropwise into the reactor. During the addition, the ultrasonic device and the stirring device are kept running, and the initiator dilution is added dropwise with a delay; the dropping rate of the pre-emulsion is controlled in stages, and when the pre-emulsion remains at 1 / 4 to 1 / 3 of its weight, the non-ionic surfactant is added dropwise;

[0044] S6: After the reaction is completed, the temperature is kept high, and a shell monomer emulsion composed of a hard monomer, a functional monomer D, an anionic surfactant, deionized water A and the remaining initiator is prepared on the basis of the hard-soft interlayer structure; the ultrasonic device and the stirring device are kept running during the dropwise addition;

[0045] S7: After the reaction is completed, the temperature is kept for a period of time, and an oxidant and a reducing agent are added dropwise for post-treatment;

[0046] S8: After the temperature is lowered to below 55°C, a pH regulator is added to adjust the pH to between 6.5 and 7.5;

[0047] S9: After the temperature continues to drop to below 40°C, a fungicide and solid content adjustment water are added, and the final product is obtained after filtration;

[0048] Step S1 and step S2 are in no particular order;

[0049] As a further solution of the present invention:

[0050] In S1, a hard monomer is added, preferably, the hard monomer is methyl methacrylate;

[0051] Adding a soft monomer, preferably, the soft monomer is butyl acrylate;

[0052] Adding functional monomer A, functional monomer B, functional monomer C, and functional monomer D, preferably, the functional monomer A is methacrylic acid, the functional monomer B is vinyltrimethoxysilane A171, the functional monomer C is hydroxypropyl methacrylate, and the functional monomer D is acrylonitrile;

[0053] An anionic surfactant is added, preferably, the anionic surfactant is sodium dodecyl sulfate; in S1, a reactive surfactant is added, preferably, the reactive surfactant is AMPS; in S1-2, the ultrasonic device used includes but is not limited to an ultrasonic emulsifier, an ultrasonic disperser, an ultrasonic homogenizer, an ultrasonic cleaner, an ultrasonic processor, etc., preferably, the ultrasonic device is a handheld ultrasonic homogenizer;

[0054] The stirring device used includes but is not limited to a magnetic stirrer, a mechanical stirrer, an overhead stirrer, an oscillating stirrer, etc. Preferably, the stirring device is a mechanical stirrer;

[0055] In S1-3, the temperature in the reactor is 58-84°C;

[0056] In S3, a pH regulator is added, preferably, the pH regulator is sodium bicarbonate;

[0057] In S2 and S5-6, an initiator is added, preferably, the initiator is ammonium persulfate;

[0058] In S5, the total dripping time is 4 h, and the dripping speed in the last three and a half hours is twice that in the first half hour;

[0059] In S5, a nonionic surfactant is added, preferably, the nonionic surfactant is fatty alcohol polyoxyethylene ether;

[0060] In S7, after the reaction is completed, the temperature is kept for 0.5-1.5 hours, and after the temperature is kept, the temperature is lowered to 68-72° C., and an oxidant and a reducing agent are added dropwise, and after the addition is completed, the temperature is kept for 0.5-1.5 hours; in S7, an oxidant is added, preferably, the oxidant is tert-butyl hydroperoxide; and a reducing agent is added, preferably, the reducing agent is tert-butyl hydroperoxide;

[0061] In S8, a pH regulator is added, preferably, the pH regulator is aqueous ammonia;

[0062] In S9, a fungicide is added, preferably, the fungicide is used in a mixture of BIT:MIT=3:1;

[0063] In S9, the final solid content range is controlled at 49-53% after adding solid content adjustment water;

[0064] In S9, a 250-mesh filter cloth is used for filtering.

[0065] The primer initiator and the subsequent dripping initiator are both added in the form of aqueous solution, and the weight ratio of the primer initiator to the subsequent dripping initiator is 3:1; the primer initiator is first dripped with an initiator, and then the same initiator is dripped again subsequently.

[0066] The beneficial effects of the present invention are:

[0067] The present invention greatly improves the waterproof performance, increases the film thickness, significantly improves the use performance, and can be applied to more scenarios by compounding monomers, functional monomers, anionic surfactants, nonionic surfactants, reactive surfactants (emulsifiers), initiators (anions), pH adjusters (sodium hydroxide, baking soda), reducing agents, bactericides and deionized water in appropriate proportions, especially compounding methacrylic acid with vinyltrimethoxysilane.

[0068] The functional monomer A methacrylic acid used in the present invention contains a carboxyl group, which can provide the polarity of the polymer, enhance the adhesion and water resistance of the coating film, and also increase the hardness and chemical resistance of the emulsion.

[0069] The functional monomer B vinyltrimethoxysilane used in the present invention can participate in the polymerization reaction during the emulsion polymerization process and combine with the polymer chain, thereby improving the comprehensive properties of the coating film, such as adhesion, water resistance, hardness, moisture resistance, solvent resistance and the like.

[0070] The functional monomer C hydroxypropyl methacrylate used in the present invention can increase the stability of the core-shell structure by introducing hydroxypropyl methacrylate with relatively weak hydrophilicity into the intermediate layer structure.

[0071] The functional monomer D acrylonitrile used in the present invention is helpful to improve the stability and performance of the emulsion.

[0072] The invention improves on the basic pure acrylic emulsion core-shell structure, and manufactures a multilayer core-shell structure with hard-soft-hard characteristics through segmented reaction, thereby having better mechanical properties.

[0073] The handheld ultrasonic homogenizer used in the present invention generates a cavitation effect through high-frequency vibration. This special preparation process can effectively promote the mixing and emulsification of different components, improve the dispersibility of polymer particles in the emulsion, reduce bubbles generated by stirring during the production process, reduce particle agglomeration, achieve the purpose of reducing the emulsion particle size, make the reaction more uniform, improve the overall quality of the emulsion, and increase the solid content of the emulsion.

[0074] The three surfactants used in the present invention can produce a synergistic effect and improve the comprehensive performance of the emulsion.

[0075] (1) The anionic surfactant sodium lauryl sulfate provides good emulsification effect and water resistance.

[0076] (2) Nonionic surfactant fatty alcohol polyoxyethylene ether enhances the stability of the emulsion and improves the coating properties.

[0077] (3) The reactive surfactant 2-acrylamide-2-methylpropanesulfonic acid significantly improves the degree of reaction by participating in the polymerization reaction, reduces the residual monomer content in the emulsion, and improves the water whitening resistance and mechanical properties of the emulsion through copolymerization.

[0078] The weight ratio of the primer initiator used in the present invention to the subsequent dripping initiator is 3:1, which helps to quickly start the reaction at the initial stage of the polymerization reaction to form a stable emulsion seed, and then maintain a stable polymerization rate by dripping the initiator, thereby controlling the particle size and distribution of the polymer particles. Finally, an emulsion product with uniform particle size, good stability and high transparency is obtained. DETAILED DESCRIPTION

[0079] The embodiments of the present invention are further described below in conjunction with the examples.

[0080] Hard monomer 225 parts (first stage ( 步骤S1-S2) 85 parts, the third stage (steps S6-S7) 140 parts), soft monomer 135 parts, functional monomer A 10 parts, functional monomer B 3 parts, functional monomer C 3 parts, functional monomer D 3 parts, anionic surfactant 17 parts, deionized water A 150 parts (60 parts in the first stage, 90 parts in the third stage), deionized water B 245 parts, non-ionic surfactant 7 parts, initiator 2 parts, oxidant 1 part, reductant 1 part, pH regulator 4 parts, bactericide 14 parts, deionized water C 100 parts, solid content adjustment water 55 parts, the deionized water is the same pure water, but the number of deionized water AC is different.

[0081] S1: At a certain temperature in the reactor, a reactive surfactant and deionized water B are added into the reactor and dispersed evenly to prepare a reactor bottom liquid;

[0082] S2: at a certain temperature in the emulsification kettle, part of the hard monomer, functional monomer C, primer initiator, anionic surfactant, and deionized water A are added into the emulsification kettle, dispersed evenly under the synergistic effect of the ultrasonic device and the stirring device, and kept warm to obtain the core layer seed emulsion;

[0083] S3: at a certain temperature in the reactor, the soft monomer, the functional monomer A and the functional monomer B are added into the emulsification reactor, and are evenly dispersed under the synergistic effect of the ultrasonic device and the stirring device to obtain a pre-emulsified liquid;

[0084] S4: Adding a pH regulator into the reactor to adjust the pH of the materials in the reactor to be weakly acidic;

[0085] S5: After the primer initiator is stirred evenly, the pre-emulsion and the initiator are added dropwise into the reactor. During the addition, the ultrasonic device and the stirring device are kept running, and the initiator dilution is added dropwise with a delay; the dropping rate of the pre-emulsion is controlled in stages, and when the pre-emulsion remains at 1 / 4 to 1 / 3 of its weight, the non-ionic surfactant is added dropwise;

[0086] S6: After the reaction is completed, the temperature is kept high, and a shell monomer emulsion composed of a hard monomer, a functional monomer D, an anionic surfactant, deionized water A and the remaining initiator is prepared on the basis of the hard-soft interlayer structure; the ultrasonic device and the stirring device are kept running during the dropwise addition;

[0087] S7: After the reaction is completed, the temperature is kept for a period of time, and an oxidant and a reducing agent are added dropwise for post-treatment;

[0088] S8: After cooling to below 55°C, add a pH adjuster to adjust the pH to between 6.5 and 7.5;

[0089] S9: After the temperature continues to drop to below 40°C, a fungicide and solid content adjustment water are added, and the final product is obtained after filtration;

[0090] Step S1 and step S2 are in no particular order;

[0091] The hard monomer is methyl methacrylate, the soft monomer is butyl acrylate, the functional monomer A is methacrylic acid, the functional monomer B is vinyl trimethoxysilane A171, the functional monomer C is hydroxypropyl methacrylate, and the functional monomer D is acrylonitrile. The anionic surfactant is sodium dodecyl sulfate. The reactive surfactant is AMPS, the pH regulator is sodium bicarbonate, the initiator is ammonium persulfate, the nonionic surfactant is fatty alcohol polyoxyethylene ether, the oxidant is tert-butyl hydroperoxide, the reducing agent is tert-butyl hydroperoxide, the pH regulator is ammonia water, and the bactericide is a mixture of BIT:MIT=3:1.

[0092] The ultrasonic device used includes, but is not limited to, an ultrasonic emulsifier, an ultrasonic disperser, an ultrasonic homogenizer, an ultrasonic cleaner, an ultrasonic processor, etc. Preferably, the ultrasonic device is a handheld ultrasonic homogenizer.

[0093] The stirring device used includes, but is not limited to, a magnetic stirrer, a mechanical stirrer, an overhead stirrer, an oscillating stirrer, etc. Preferably, the stirring device is a mechanical stirrer.

[0094] In S1-3, the temperature in the reactor is 79-84°C;

[0095] In S5, the total dripping time is 4 h, and the dripping speed in the last three and a half hours is twice that in the first half hour;

[0096] In S7, after the reaction is completed, the temperature is kept at 0.5-1.5 hours, after the temperature is kept at 58-63°C, an oxidant and a reducing agent are added dropwise, and after the addition is completed, the temperature is kept at 0.5-1.5 hours;

[0097] In Example 1, no vinyl trimethoxysilane, no reactive surfactant, and no handheld ultrasonic homogenizer are used in the multilayer emulsion formula. The finished product has low water absorption, excellent yellowing resistance, and similar particle size, solid content, viscosity, transparency, water resistance, and adhesion to general pure acrylic waterproof emulsions. It has a certain ability to purify formaldehyde, but does not meet the use requirements.

[0098] In Example 2, the multilayer emulsion formula does not use vinyl trimethoxysilane, does not use reactive surfactants, and uses a handheld ultrasonic homogenizer, which can improve the emulsification effect, but has no significant effect on the control of particle size. The particle size of the finished product is slightly reduced, the formaldehyde purification ability is slightly reduced, the solid content is increased, the viscosity is increased, the transparency and water resistance do not change significantly, the water absorption rate is improved, and the adhesion does not meet the use requirements.

[0099] In Example 3, vinyl trimethoxysilane is not used in the multilayer emulsion formula, but a reactive surfactant is used. A handheld ultrasonic homogenizer is used. After adding the reactive surfactant, the particle size of the emulsion is reduced. AMPS contains a sulfonic acid group and can provide good water resistance. The particle size of the finished product is reduced to below 50 nm, the formaldehyde purification capacity does not change much, the solid content is significantly increased, the viscosity is increased, the transparency and water resistance are significantly changed, the water absorption rate is slightly reduced, and the adhesion meets the use requirements.

[0100] In Example 4, vinyl trimethoxy silane is used in the emulsion formula of the multilayer structure, and no reactive surfactant is used. A handheld ultrasonic homogenizer is used. After adding vinyl trimethoxy silane, it can react with water to form silanol, thereby improving the water resistance and chemical resistance of the emulsion, and improving the stability of the emulsion and the mechanical properties of the emulsion. The particle size of the finished product is about 50nm, the formaldehyde purification ability is slightly improved, the solid content is slightly improved, the viscosity is significantly increased, the transparency and water resistance meet the requirements, the water absorption rate is slightly reduced, and the adhesion meets the use requirements.

[0101] In Example 5, vinyl trimethoxysilane, a reactive surfactant, and a handheld ultrasonic homogenizer are used in the multilayer emulsion formula. This embodiment can provide a highly water-resistant, highly transparent, multilayer pure acrylic emulsion formula without sacrificing the performance of the emulsion. The particle size of the finished product remains at about 50nm, the formaldehyde purification ability does not change much, the solid content is slightly improved, the viscosity is large, the appearance is clear, the water resistance is excellent, the water absorption rate is low, and the adhesion meets the use requirements, achieving the innovative purpose of the present invention, as the final solution.

[0102] Comparative Example 1 is a commercially available pure acrylic waterproof emulsion. The test results show that the water absorption rate is high, the solid content is low, the water whitening resistance is insufficient, the adhesion is unqualified, the film-forming strength is low, and it is easy to yellow. It is used as a comparative example to compare with other embodiments of this patent.

[0103] Comparative Example 2 is a commercially available pure acrylic waterproof core-shell structure emulsion. The test results are: the particle size is relatively large, the solid content is high, the water whitening resistance is average, the water absorption rate is low, the adhesion is unqualified, and the yellowing resistance is high. It is used as a comparative example to compare with other embodiments of this patent.

[0104] In the multi-layer emulsion formula of Comparative Example 3, the functional monomer A methacrylic acid is not used, and an equal amount of functional monomer B is used instead, and the rest is the same as in Example 5.

[0105] In the multi-layer emulsion formula of Comparative Example 4, the functional monomer C hydroxypropyl methacrylate is not used, and an equal amount of functional monomer B is used instead, and the rest is the same as in Example 5.

[0106] In the emulsion formula of the multilayer structure of Comparative Example 5, the functional monomer D acrylonitrile is not used, and an equal amount of functional monomer B is used instead, and the rest is the same as in Example 5.

[0107] In summary, functional monomer A methacrylic acid, functional monomer B vinyltrimethoxysilane A171, functional monomer C hydroxypropyl methacrylate, functional monomer D acrylonitrile, and reactive surfactant need to be used in combination with a synergistic effect to jointly exert the effects of high water resistance, high transparency and high weather resistance to obtain a multi-layered pure acrylic waterproof emulsion with stable and moderate particle size, strong formaldehyde purification ability, increased solid content, high viscosity, clear appearance, excellent water resistance, low water absorption, and adhesion that meets the requirements for use.

[0108] The differences and test results of Examples 1-5 and Comparative Examples 1-5 are detailed in the following table, Table 1.

[0109] Table 1 Differences among groups and test results

[0110]

[0111]

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly water-resistant, highly transparent and highly weather-resistant multi-layered pure acrylic waterproof emulsion, characterized in that: The main ingredients and proportions include: emulsion, reactor materials, and additives; The emulsion comprises: 140-330 parts of hard monomer, preferably 180-250 parts; 90-180 parts of soft monomer, preferably 120-150 parts; 6-15 parts of functional monomer A, preferably 9-13 parts; 1-6 parts of functional monomer B, preferably 2-4 parts; 1-6 parts of functional monomer C, preferably 2-4 parts; 1-6 parts of functional monomer D, preferably 2-4 parts; 5-30 parts of anionic surfactant, preferably 15-20 parts; 100-200 parts of deionized water A, preferably 130-170 parts; The materials of the reactor include: 0.1-5 parts of reactive surfactant, preferably 0.5-3.5 parts; 150-350 parts of deionized water B, preferably 230-280 parts; The auxiliary agent composition includes: 2-14 parts of non-ionic surfactant, preferably 5-11 parts; 1-4 parts of initiator, preferably 1.5-3 parts; 0.1-3 parts of oxidant, preferably 0.5-2 parts; 0.1-3 parts of reducing agent, preferably 0.5-2 parts; 2-6 parts of pH regulator, preferably 3-5 parts; 10-20 parts of bactericide, preferably 12-16 parts; 50-150 parts of deionized water, preferably 80-120 parts; 30-80 parts of solid content adjusting water, preferably 45-65 parts.

2. The highly water-resistant, highly transparent and highly weather-resistant multi-layer pure acrylic waterproof emulsion according to claim 1, characterized in that: The hard monomer types include, but are not limited to, one or more monomers such as methyl methacrylate and butyl methacrylate; The soft monomers include, but are not limited to, one or more of isooctyl acrylate, ethyl acrylate, butyl acrylate, and the like; The types of the functional monomers A / C / D include, but are not limited to, one or more of acrylic acid, methacrylic acid, allyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, acrylonitrile, acrylamide, hydroxypropyl acrylate, hydroxypropyl methacrylate, acrylic acid itaconic acid and the like; The functional monomer B includes, but is not limited to, one or more of vinyl triethoxysilane A151, vinyl trimethoxysilane A171, vinyl tri(β-methoxyethoxy)silane A172, γ-aminopropyl triethoxysilane KH-550, γ-aminopropyl trimethoxysilane KH560, and γ-methacryloxypropyl trimethoxysilane KH570; The types of anionic surfactants include, but are not limited to, one or more of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, alkyl sulfonates, potassium lauryl phosphate, fatty acid soaps and the like; The types of nonionic surfactants include, but are not limited to, one or more of fatty alcohol polyoxyethylene ethers, allyl propylene oxide ethers, fatty acid polyoxyethylene esters, polyoxyethylene-polyoxypropylene copolymers, alkyl polyglucosides, saturated fatty acid glycerides, polysorbates, and the like.

3. The highly water-resistant, highly transparent and highly weather-resistant multi-layered pure acrylic waterproof emulsion according to claim 1, characterized in that: The types of reactive surfactants include, but are not limited to, one or more of sodium p-styrene sulfonate, sodium vinyl sulfonate, monopolyethylene glycol acrylate, terminal acrylate-based waterborne polyurethane, AMPS (2-acrylamide-2-methylpropane sulfonic acid), COPS (methoxyethyl acrylate phosphate) reagents, and the like.

4. The highly water-resistant, highly transparent and highly weather-resistant multi-layer pure acrylic waterproof emulsion according to claim 1, characterized in that: The initiator types include, but are not limited to, one or more of potassium persulfate, sodium persulfate, ammonium persulfate, benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile and the like; The types of pH adjusters include, but are not limited to, one or more of ammonia water, sodium hydroxide, sodium bicarbonate, sodium dihydrogen phosphate and the like; The oxidant type includes but is not limited to one or more of tert-butyl hydroperoxide, hydrogen peroxide, diisopropylbenzene hydroperoxide and the like; The reducing agent includes, but is not limited to, one or more of sodium sulfite, sodium bisulfite, sodium pyrosulfite, organic sulfinic acid sodium salt, sodium formaldehyde sulfoxylate and the like; The types of bactericides include, but are not limited to, one or more of kasone, phenoxyethanol, parabens, bromopol, isothiazolinone, diphenylisothiazolinone, sodium benzoate, potassium sorbate, hydrogen peroxide and the like.

5. A method for preparing a highly water-resistant, highly transparent and highly weather-resistant multi-layered pure acrylic waterproof emulsion, characterized in that: The raw materials of the emulsion include the main components and proportions as described in any one of claims 1 to 4, The following steps are involved: S1: At a certain temperature in the reactor, a reactive surfactant and deionized water B are added into the reactor and dispersed evenly to prepare a reactor bottom liquid; S2: At a certain temperature in the emulsification kettle, hard monomer, functional monomer C, primer initiator, anionic surfactant and deionized water A are added into the emulsification kettle, dispersed evenly under the synergistic effect of ultrasonic device and stirring device, and the core layer seed emulsion is obtained after heat preservation; S3: at a certain temperature in the reactor, the soft monomer, the functional monomer A and the functional monomer B are added into the emulsification reactor, and are evenly dispersed under the synergistic effect of the ultrasonic device and the stirring device to obtain a pre-emulsified liquid; S4: Adding a pH regulator into the reactor to adjust the pH of the materials in the reactor to be weakly acidic; S5: After the primer initiator is stirred evenly, the pre-emulsion and the initiator are added dropwise into the reactor. During the addition, the ultrasonic device and the stirring device are kept running, the initiator dilution is added dropwise with a delay, and the dropping rate of the pre-emulsion is controlled in stages. When the pre-emulsion is added until 1 / 4 to 1 / 3 of its weight remains, a non-ionic surfactant is added dropwise to form an intermediate layer structure. S6: After the reaction is completed, the temperature is kept high, and a shell monomer emulsion composed of a hard monomer, a functional monomer D, an anionic surfactant, deionized water A and the remaining initiator is prepared on the basis of the hard-soft interlayer structure, and the ultrasonic device and the stirring device are kept running during the dropwise addition; S7: After the reaction is completed, the temperature is kept for a period of time, and an oxidant and a reducing agent are added dropwise for post-treatment; S8: After cooling to below 55°C, a pH regulator is added; S9: After the temperature continues to drop to below 40°C, a fungicide and solid content adjustment water are added, and the final product is obtained after filtration; There is no particular order for step S1 and step S2.

6. The method for preparing the highly water-resistant, highly transparent and highly weather-resistant multi-layered pure acrylic waterproof emulsion according to claim 5, characterized in that: The preparation method satisfies at least one of the following conditions: In S1, a hard monomer is added, preferably, the hard monomer is methyl methacrylate; a soft monomer is added, preferably, the soft monomer is butyl acrylate; functional monomer A, functional monomer B, functional monomer C, functional monomer D are added, preferably, the functional monomer A is methacrylic acid, the functional monomer B is vinyltrimethoxysilane A171, the functional monomer C is hydroxypropyl methacrylate, and the functional monomer D is acrylonitrile; an anionic surfactant is added, preferably, the anionic surfactant is sodium dodecyl sulfate; In S1, a reactive surfactant is added, preferably, the reactive surfactant is AMPS; In S1-2, the ultrasonic device used includes but is not limited to an ultrasonic emulsifier, an ultrasonic disperser, an ultrasonic homogenizer, an ultrasonic cleaner, an ultrasonic processor, etc. Preferably, the ultrasonic device is a handheld ultrasonic homogenizer; the stirring device used includes but is not limited to a magnetic stirrer, a mechanical stirrer, an overhead stirrer, an oscillating stirrer, etc. Preferably, the stirring device is a mechanical stirrer; In S1-3, the temperature in the reactor is 58-84°C; In S3, a pH regulator is added, preferably, the pH regulator is sodium bicarbonate; In S2 and S5-6, an initiator is added, preferably, the initiator is ammonium persulfate; In S5, the total dripping time is 4 h, and the dripping speed in the last three and a half hours is twice that in the first half hour; In S5, a nonionic surfactant is added, preferably, the nonionic surfactant is fatty alcohol polyoxyethylene ether; In S7, after the reaction is completed, the temperature is kept for 0.5-1.5 hours, and after the temperature is kept, the temperature is lowered to 68-72° C., and an oxidant and a reducing agent are added dropwise, and after the addition, the temperature is kept for 0.5-1.5 hours; in S7, an oxidant is added, preferably, the oxidant is tert-butyl hydroperoxide; and a reducing agent is added, preferably, the reducing agent is sodium formaldehyde sulfoxylate; In S8, a pH regulator is added, preferably, the pH regulator is aqueous ammonia; In S9, a fungicide is added, preferably, the fungicide is used in a mixture of BIT:MIT=3:1; In S9, the final solid content range is controlled at 49-53% after adding solid content adjustment water; In S9, a 250-mesh filter cloth is used for filtering.

7. The method for preparing the highly water-resistant, highly transparent and highly weather-resistant multi-layered pure acrylic waterproof emulsion according to claim 6, characterized in that: The primer initiator and the subsequent dripping initiator are both added in the form of aqueous solution, and the weight ratio of the primer initiator to the subsequent dripping initiator is 3:

1.

8. A highly water-resistant, highly transparent and highly weather-resistant multi-layered pure acrylic waterproof emulsion, characterized in that: The invention is prepared by the method for preparing a highly water-resistant, highly transparent and highly weather-resistant multi-layered pure acrylic waterproof emulsion as claimed in any one of claims 5 to 7.

9. An application of the highly water-resistant, highly transparent and highly weather-resistant multi-layer pure acrylic waterproof emulsion as described in any one of claims 1 to 4 or the preparation method as described in any one of claims 5 to 7 in the field of exterior wall waterproofing and tile waterproofing construction.

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