Fluorosilicone modified asphalt waterproof coating as well as preparation method and application thereof

Abstract

The invention provides a fluorosilicone modified asphalt waterproof coating and a preparation method and application thereof, and relates to the technical field of waterproof coatings, the fluorosilicone modified asphalt waterproof coating comprises the following components: a modified acrylate emulsion and emulsified modified asphalt; the modified acrylate emulsion is prepared from methyl methacrylate, butyl acrylate, trifluoroethyl methacrylate, beta-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile through a seed emulsion polymerization method; the modified asphalt comprises asphalt modified by fluorine-containing polymer microspheres and gamma-glycidyl ether oxypropyl trimethoxy silane. The water-based asphalt waterproof coating solves the technical problems that the water-based asphalt waterproof coating is easy to bulge under high temperature and high humidity due to low binding power and low tensile strength, and is poor in high and low temperature resistance, poor in water resistance, poor in chemical resistance stability and poor in weather resistance, and achieves the purpose that the water-based asphalt waterproof coating is exposed for use; and the technical effect of meeting the weather resistance requirement in the current waterproof general standard of buildings and municipal engineering is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of waterproof coatings, and in particular to a fluorosilicone modified asphalt waterproof coating and a preparation method and application thereof. Background Art

[0002] Since water-based modified asphalt waterproof coating uses water instead of organic solvent as a dispersion medium, it reduces the volatilization and release of toxic solvents, and is easy to operate. It can be sprayed or rolled at room temperature, which meets the requirements of green and low-carbon environmental protection. After the water in the water-based modified asphalt waterproof coating evaporates, the cured coating film has the characteristics of strong sealing and large elongation, and is widely used in waterproofing projects such as toilets, building exterior walls, underground projects, and reservoirs. However, the performance of ordinary water-based asphalt waterproof coatings is difficult to fully meet the needs of actual applications. It has the disadvantages of low adhesion and low tensile strength. It is prone to bulging and other problems in hot and humid weather. At the same time, it has poor resistance to high and low temperature differences, water resistance, chemical stability and weather resistance. Therefore, it has huge risks when used in underground projects and roofs for direct exposure, and further modification is necessary.

[0003] At present, polymers are usually used as asphalt modifiers to make the modified water-based asphalt waterproof coating have higher low-temperature flexibility and heat resistance; styrene-butadiene-styrene block copolymer (SBS) is the most commonly used asphalt modifier modified among polymers, which can not only improve the low-temperature flexibility of water-based asphalt waterproof coatings, but also improve the heat resistance. However, due to the large difference in the structural composition of SBS and asphalt, the system is unstable when the two are blended, and phase separation is prone to occur. Maleic anhydride (MAH) modification can increase the high-temperature stability of asphalt and improve the compatibility of asphalt with polymers. By grafting polar groups such as MAH on the SBS molecular chain, the compatibility and adhesion properties of SBS with polar compounds can be improved, thereby improving the stability of the waterproof coating system. Huang Jinhua et al. found through fluorescence microscopy and separation tests that adding a certain amount of MAH can significantly improve the compatibility of asphalt and SBS, thereby effectively improving the stability of the modified asphalt; however, the above modification only improved the stability and high and low temperature resistance of the water-based asphalt coating, and did not significantly improve the shortcomings such as weather resistance, water resistance, chemical stability, low strength and poor adhesion.

[0004] The asphalt coating modified polymer emulsions used in the prior art include styrene-acrylic emulsion, pure acrylic emulsion, VAE emulsion, styrene-butadiene latex and chloroprene latex. Styrene-acrylic emulsion is prepared by emulsion copolymerization of styrene and acrylic monomers, and its cost is low, but in styrene, the tertiary carbon atom connected to the benzene ring is easily oxidized to cause the main chain to break, generating a chromophore group, and the weather resistance is poor. Pure acrylic emulsion is prepared by emulsion copolymerization of acrylic monomers, and has excellent weather resistance and flexibility. Since the polymer molecular chain contains more carboxyl groups, the molecular polarity is relatively large. Although it has strong adhesion to the base layer, its water resistance is worse than that of styrene-acrylic emulsion. Styrene-butadiene latex is obtained by copolymerization of butadiene and styrene emulsions, and its performance in water resistance is better than that of acrylic emulsions, but its bonding strength is average, and it hardens after aging. Chloroprene latex has strong bonding ability and strength, and also has good heat resistance and aging resistance, but it is expensive and has poor low temperature resistance. VAE emulsion is made by high-pressure emulsion polymerization of vinyl acetate and ethylene monomers. It has relatively large molecular polarity and strong adhesion to the base layer, but its long-term water resistance and heat resistance are poor and it will gradually lose its flexibility, making it impossible to use in a directly exposed environment.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] One of the purposes of the present invention is to provide a fluorosilicone modified asphalt waterproof coating that can be used directly exposed to the outside and meet the weather resistance requirements of the current general waterproofing specifications for buildings and municipal engineering.

[0007] The second object of the present invention is to provide a method for preparing a fluorosilicone modified asphalt waterproof coating, which has a simple process, high efficiency, high success rate and is suitable for industrial production.

[0008] The third object of the present invention is to provide an application of a fluorosilicone modified asphalt waterproof coating, which is beneficial to taking into account high and low temperature resistance, weather resistance, water resistance, chemical stability, strength and adhesion, and is beneficial to reducing the risks when directly exposed to the outside.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] In the first aspect, a fluorosilicone modified asphalt waterproof coating comprises the following components:

[0011] Modified acrylic emulsion and emulsified modified asphalt;

[0012] The modified acrylic emulsion is prepared by seed emulsion polymerization of methyl methacrylate, butyl acrylate, trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile;

[0013] The modified asphalt includes asphalt modified by fluorine-containing polymer microspheres and gamma-glycidyloxypropyltrimethoxysilane.

[0014] Furthermore, the weight ratio of methyl methacrylate, butyl acrylate, trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile is (11-15): (31-37.5): (0.25-2): (0.5-2.5): (0.5-2): (0.25-2).

[0015] Furthermore, the fluorine-containing polymer microspheres are prepared by dispersion polymerization of dodecafluoroheptyl methacrylate, glycidyl acrylate and azobisisobutyronitrile in a dispersion medium.

[0016] Furthermore, the dispersion medium includes ethanol and water.

[0017] Furthermore, the preparation method of the modified asphalt comprises the following steps:

[0018] The asphalt is melted and then dehydrated, and then fluorine-containing polymer microspheres and gamma-glycidyloxypropyltrimethoxysilane are added for dispersion to obtain modified asphalt.

[0019] Furthermore, the amount of the fluorine-containing polymer microspheres added is 2%-5% of the weight of the asphalt.

[0020] Furthermore, the added amount of the γ-glycidyloxypropyltrimethoxysilane is 2%-5% of the weight of the asphalt.

[0021] Furthermore, the components also include at least one of heavy calcium, silicon powder and barium sulfate.

[0022] In a second aspect, a method for preparing the fluorosilicone modified asphalt waterproof coating as described in any one of the above items comprises the following steps:

[0023] The components are mixed to obtain the fluorosilicone modified asphalt waterproof coating.

[0024] A third aspect is the use of a fluorosilicone modified asphalt waterproof coating as described in any of the above items in engineering waterproofing.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] The fluorosilicone modified asphalt waterproof coating provided by the present invention includes modified acrylate emulsion and emulsified asphalt; wherein the modified acrylate emulsion is prepared by seed emulsion polymerization with methyl methacrylate and butyl acrylate as main monomers, trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile as functional monomers, and the modified acrylate emulsion can show excellent tensile properties, weather resistance, stain resistance, water resistance, chemical stability and excellent adhesion; at the same time, the asphalt is modified with fluorine-containing polymer microspheres and γ-glycidyl ether oxygen propyl trimethoxy silane, and the emulsified asphalt obtained has better storage stability, extremely low surface energy, better hydrophobic and oleophobic properties, excellent heat resistance and excellent chemical stability and weather resistance. In short, the asphalt waterproof coating of the present invention can realize the direct exposure of water-based asphalt waterproof coating under the action of specific film-forming substances, meet the weather resistance requirements in the current general specifications for waterproofing of buildings and municipal engineering, and also have high application potential in other industrial fields.

[0027] The preparation method of the fluorosilicone modified asphalt waterproof coating provided by the invention has simple process, high efficiency, high success rate and is suitable for industrial production.

[0028] The application of the fluorosilicone modified asphalt waterproof coating provided by the present invention is beneficial to taking into account high and low temperature resistance, weather resistance, water resistance, chemical stability, strength and adhesion, and is beneficial to reducing the risks when directly exposed to the outside. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] At present, water-based asphalt waterproof coatings are widely used, mainly in building waterproofing, roads and bridges, underground engineering, water conservancy projects and industrial fields, but when used as a waterproof layer directly exposed on the roof of a building, the strategy to achieve the best performance is still very challenging. In view of this, the present invention is specially proposed.

[0031] According to a first aspect of the present invention, there is provided a fluorosilicone modified asphalt waterproof coating, comprising the following components:

[0032] Modified acrylic emulsion and emulsified modified asphalt;

[0033] The modified acrylic emulsion is prepared from methyl methacrylate, butyl acrylate, trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile by seed emulsion polymerization.

[0034] The modified asphalt includes asphalt modified by fluoropolymer microspheres and γ-glycidyloxypropyltrimethoxysilane.

[0035] The fluorosilicone modified asphalt waterproof coating provided by the present invention comprises a modified acrylate emulsion and an emulsified asphalt; wherein the modified acrylate emulsion is prepared by a seed emulsion polymerization method using methyl methacrylate and butyl acrylate as main monomers and trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile as functional monomers, and the modified acrylate emulsion can exhibit excellent tensile properties, weather resistance, stain resistance, water resistance, chemical stability and excellent adhesion; at the same time, the asphalt is modified by using fluorine-containing polymer microspheres and γ-glycidyloxypropyltrimethoxysilane, and the obtained emulsified asphalt has better storage stability, extremely low surface energy, better hydrophobic and oleophobic properties, excellent heat resistance, and outstanding chemical stability and weather resistance.

[0036] In summary, under the action of specific film-forming substances, the asphalt waterproof coating of the present invention can realize the direct exposure use of water-based asphalt waterproof coating, meet the weather resistance requirements in the current general specifications for waterproofing of buildings and municipal engineering, and also have high application potential in other industrial fields.

[0037] In a preferred embodiment, the weight ratio of methyl methacrylate, butyl acrylate, trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile can be (11-15): (31-37.5): (0.25-2): (0.5-2.5): (0.5-2): (0.25-2).

[0038] In the present invention, methyl methacrylate and butyl acrylate are used as main monomers, and a small amount of trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile are used as functional monomers. Under the conditions of specific monomers and specific dosages, the modified acrylic ester emulsion obtained by seed emulsion polymerization has excellent tensile properties, weather resistance, stain resistance, water resistance, chemical stability and excellent adhesion.

[0039] It should be noted that the modified acrylic emulsion uses methyl methacrylate and butyl acrylate as the main monomers. Methyl methacrylate not only has high hardness, but also has good stain resistance and good adhesion to the base layer. Since it does not contain tertiary hydrogen atoms, it is stable to light and oxygen and has excellent weather resistance. Butyl acrylate has excellent flexibility and water resistance, and also has better weather resistance than styrene monomer. In addition, during the polymerization reaction or curing process, the hydroxyl, amide, carboxyl and nitrile groups on the functional monomers will undergo cross-linking reactions to form a three-dimensional network structure, which can further improve the density of the coating, reduce water absorption, and enhance the overall mechanical properties, chemical stability and aging resistance of the coating.

[0040] It should be noted that the use of modified acrylic emulsion as the polymer emulsion in water-based asphalt waterproof coatings has better water resistance when constructed on new cement base surfaces than polyvinyl acetate emulsion. This is because the calcium salt generated by the saponification of acrylic emulsion coatings when exposed to alkali is insoluble in water, while the polyvinyl alcohol generated by the saponification of polyvinyl acetate emulsions when exposed to alkali is water-soluble, so its water resistance is poor.

[0041] It should be noted that the modified acrylic emulsion is modified with a small amount of trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile as functional monomers. In the polymer chain segment of the acrylic polymer, uniformly distributed hydroxyl, amide, carboxyl and nitrile groups are introduced. These functional groups can undergo self-crosslinking during the polymerization process to form a three-dimensional network structure. The introduction of a small amount of polar groups, hydroxyl, carboxyl and nitrile groups, can further improve the tensile properties and chemical resistance of water-based asphalt anti-corrosion coatings compared to ordinary acrylic emulsions without affecting the water resistance. Stability and bonding strength with the base layer; at the same time, the carboxyl group and the amide group can react chemically with the Ca(OH)2 generated by the hydration of cement in the concrete base layer to generate a macromolecular network interwoven structure bonded by ionic bonds, which inhibits the alkali efflux of the coating and improves the appearance of the product; trifluoroethyl methacrylate is a fluorine-containing monomer. Its proper addition will not affect the mechanical and chemical stability of the emulsion. Based on the surface active effect, low surface tension and hydrophobic effect of fluorine, it is more conducive to improving the stability of the emulsion during the polymerization process, and can significantly improve the weather resistance, stain resistance, acid resistance and durability of the acrylic emulsion.

[0042] A typical preparation method of a modified acrylic emulsion comprises the following steps:

[0043] (1) According to the weight ratio, ammonium persulfate (0.05%-0.2%) and sodium bicarbonate (0.02%-0.1%) are dissolved in deionized water to form a solution, and then an anionic non-ionic composite emulsifier (0.5%-4%), sodium bicarbonate solution and deionized water are added to a reaction kettle, and the overhead stirrer is turned on at a speed of 350r / min-450r / min, and the reaction kettle is heated to 83°C-87°C. Then, the ammonium persulfate solution and methyl methacrylate (30%-40%) monomer are added dropwise to the kettle through a peristaltic pump, and the dropping rate is controlled. The addition is completed in about 1.5h-3h. After the addition is completed, the mixture is kept warm for 1h-2h, then cooled to 30°C, the heating and stirring are stopped, and the mixture is filtered through a 120-mesh filter to obtain a seed emulsion;

[0044] (2) The polymerization reaction was carried out in a 5L stainless steel polymerization apparatus with an automatic temperature control system;

[0045] First, sodium bicarbonate (0.05%-0.3%), N-hydroxymethyl acrylamide (0.5%-2%) and ammonium persulfate (0.2%-0.5%) were fully dissolved in three beakers with deionized water according to weight ratio; a reaction kettle was fixed, deionized water, trifluoroethyl methacrylate (0.25%-2%), sodium bicarbonate solution, seed emulsion (0.3%-2%) and EDTA (0.01%-0.04%) were added into the reaction kettle, free oxygen in the system was removed by vacuuming, stirring was started, the temperature was raised to 83°C-87°C, and then methyl methacrylate (11%-15%), butyl acrylate (31%-3 7.5%), β-hydroxypropyl methacrylate (0.5%-2.5%), acrylonitrile (0.25%-2%), N-hydroxymethyl acrylamide solution, anionic nonionic emulsifier (0.5%-3%) and ammonium persulfate aqueous solution, during the dropping process, the temperature fluctuation is controlled not to exceed 1.5°C, the dropping rate is controlled, and the dropping is completed in about 2h-4h. After the addition is completed, keep warm for 1h-3h, then cool to 30°C, add 15% sodium hydroxide solution (0.15%-0.5%), adjust the pH to 7-9, then add preservatives and defoamers, evacuate for 30min, stop stirring and heating, and filter with a 120-mesh filter to obtain a modified acrylic ester emulsion.

[0046] In a preferred embodiment, the fluorine-containing polymer microspheres can be prepared by dispersion polymerization of dodecafluoroheptyl methacrylate, glycidyl acrylate and azobisisobutyronitrile in a dispersion medium.

[0047] In a preferred embodiment, the dispersion medium includes but is not limited to ethanol and water.

[0048] In the present invention, dispersion polymerization is adopted, and ethanol and water are used as dispersion media to synthesize fluorine-containing polymer microspheres; the dispersion polymerization method comprises the following steps: firstly, dodecafluoroheptyl methacrylate (DFHMA), glycidyl acrylate, azobisisobutyronitrile, a dispersant, anhydrous ethanol and deionized water are added into a three-necked round-bottom flask for mixing, then nitrogen is introduced into the system by bubbling, and the nitrogen is continuously introduced while stirring the reaction in an oil bath, then the obtained product is washed with ethanol, and then centrifuged to remove the dispersant and unreacted monomers, the above steps are repeated, and finally the obtained product after centrifugation is dried, so as to obtain fluorine-containing polymer microspheres.

[0049] A typical method for preparing fluorinated polymer microspheres comprises the following steps:

[0050] First, 40g of dodecafluoroheptyl methacrylate (DFHMA), 3.55g of acrylic acid glycidyl ether, 0.5g of azobisisobutyronitrile, 4.5g of dispersant PVP-K30, 370g of anhydrous ethanol and 30g of deionized water were added to a three-necked round-bottom flask, and nitrogen was then bubbling into the system for 30 minutes, and nitrogen was continuously introduced to stir the reaction in a 75°C oil bath for 2 hours. The resulting product was then washed with ethanol and centrifuged at 3000r / min to remove the dispersant and unreacted monomers. The above steps were repeated, and the centrifuged product was finally dried in a vacuum oven at 50°C for 24 hours to obtain fluorinated polymer microspheres.

[0051] It should be noted that the fluorinated acrylate polymer microspheres synthesized by dodecafluoroheptyl methacrylate (DFHMA) and glycidyl acrylate contain multiple fluorine atoms, have a large specific surface area, and have highly reactive epoxy groups. Therefore, they can react with asphalt to modify it and interpenetrate to form a three-dimensional network structure, thereby improving the high and low temperature resistance of the asphalt, while making the asphalt have better storage stability, extremely low surface energy, better hydrophobic and oleophobic properties, excellent heat resistance, and outstanding chemical stability and weather resistance.

[0052] At the same time, the asphalt is further modified by γ-glycidyloxypropyltrimethoxysilane, and the epoxy groups on it react with asphalt, which can further improve the high and low temperature resistance of asphalt; after the modified asphalt is emulsified, the silane will hydrolyze to produce silanol; on the one hand, silanol can chemically react with the hydroxyl and carboxyl groups on the modified acrylic emulsion and the hydroxyl groups on the filler to cross-link with each other, which can combine the emulsion phase, filler phase and emulsified asphalt phase more closely to form a three-dimensional network interpenetrating structure, which improves the stability of the coating while also improving the overall mechanical properties of the coating, such as water resistance, tensile properties, high and low temperature resistance, weather resistance and chemical stability; on the other hand, silanol can react with the hydroxyl groups on the inorganic base layer to form hydrogen bonds, thereby building a "molecular bridge" between the inorganic material and the polymer material, which can effectively increase the bonding strength to the base layer.

[0053] In a preferred embodiment, the method for preparing modified asphalt comprises the following steps:

[0054] The asphalt is melted and then dehydrated, and then fluorine-containing polymer microspheres and gamma-glycidyloxypropyltrimethoxysilane are added for dispersion to obtain modified asphalt.

[0055] In the present invention, the added amount of fluoropolymer microspheres can be 2%-5% of the weight of asphalt, and its typical but non-limiting addition amount is, for example, 2%, 3%, 4%, and 5%; the added amount of γ-glycidyloxypropyltrimethoxysilane can be 2%-5% of the weight of asphalt, and its typical but non-limiting addition amount is, for example, 2%, 3%, 4%, and 5%.

[0056] In the present invention, the asphalt is first heated, and after it is completely melted, it is dehydrated by stirring, and then fluorine-containing polymer microspheres are added for stirring and dispersion, and then γ-glycidyloxypropyltrimethoxysilane is added for stirring and dispersion, thereby completing the modification of the asphalt to obtain modified asphalt.

[0057] In the present invention, the preheated emulsifier aqueous solution is first added to the opened colloid mill, and then the preheated modified asphalt is evenly poured into the colloid mill for emulsification, and then the emulsified asphalt is cooled to room temperature and filtered through a 120-mesh filter to obtain emulsified modified asphalt.

[0058] A typical preparation method of emulsified modified asphalt comprises the following steps:

[0059] Add 600g of 70# asphalt into a 500ml stainless steel container, heat the asphalt to 140°C, and after it is completely melted, stir for 30min for dehydration treatment at a speed of 300r / min-500r / min, then add 2%-5% of fluorine-containing polymer microspheres and stir and disperse for 2h, then add 2%-5% of γ-glycidyloxypropyltrimethoxysilane and stir and disperse for 2h at a speed of 300r / min-500r / min, thereby completing the modification of the asphalt to obtain modified asphalt;

[0060] 8g of anionic emulsifier, 4g of nonionic emulsifier and 2g of stabilizer are prepared into 400g of emulsifier aqueous solution, the pH is adjusted to 10-11, and heated to 60°C for use; the preheated emulsifier aqueous solution is added to the opened colloid mill, and then the preheated 140°C modified asphalt is evenly poured into the colloid mill, and the machine is stopped after emulsification for 3 minutes, the emulsified asphalt is cooled to room temperature, and filtered with a 120-mesh filter to obtain emulsified modified asphalt.

[0061] In a preferred embodiment, the components of the fluorosilicone modified asphalt waterproof coating of the present invention also include but are not limited to at least one of heavy calcium, silica powder and barium sulfate.

[0062] According to a second aspect of the present invention, there is provided a method for preparing the fluorosilicone modified asphalt waterproof coating as described in any one of the above, comprising the following steps:

[0063] The components are mixed to obtain a fluorosilicone modified asphalt waterproof coating.

[0064] The preparation method of the fluorosilicone modified asphalt waterproof coating provided by the invention has simple process, high efficiency, high success rate and is suitable for industrial production.

[0065] According to a third aspect of the present invention, there is provided a use of the fluorosilicone modified asphalt waterproof coating described in any one of the above items in engineering waterproofing.

[0066] The application of the fluorosilicone modified asphalt waterproof coating provided by the present invention is beneficial to taking into account high and low temperature resistance, weather resistance, water resistance, chemical stability, strength and adhesion, and is beneficial to reducing the risks when directly exposed to the outside.

[0067] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0068] Example 1

[0069] A fluorosilicone modified asphalt waterproof coating, comprising the following components by mass percentage:

[0070] Modified acrylic emulsion 20%, emulsified modified asphalt 40%, defoamer 0.3%, bactericide 0.3%, dispersant 0.2%, wetting agent 0.2%, thickener 0.3%, 1250 mesh heavy calcium 10%, 3000 mesh silica powder 10%, 3000 mesh precipitated barium sulfate 10%, and water 8.7%.

[0071] In this embodiment, the preparation method of the modified acrylic emulsion comprises the following steps:

[0072] (1) According to the weight ratio, ammonium persulfate (0.12%) and sodium bicarbonate (0.06%) are dissolved in deionized water to form a solution, and then an anionic non-ionic composite emulsifier (2%), sodium bicarbonate solution and deionized water are added to the reactor, the overhead stirrer is turned on, the speed is 400r / min, and the reaction is heated to 85°C, and then the ammonium persulfate solution and methyl methacrylate (35%) monomer are added dropwise to the reactor through a peristaltic pump, and the dropping rate is controlled. The addition is completed in 2 hours. After the addition is completed, the mixture is kept warm for 1.5 hours, then cooled to 30°C, the heating and stirring are stopped, and the mixture is filtered with a 120-mesh filter to obtain a seed emulsion. The total amount of deionized water involved in the formula is 62.82%;

[0073] (2) The polymerization reaction was carried out in a 5L stainless steel polymerization apparatus with an automatic temperature control system;

[0074] First, sodium bicarbonate (0.18%), N-hydroxymethyl acrylamide (1.2%) and ammonium persulfate (0.3%) were fully dissolved in three beakers with deionized water according to the weight ratio; the reaction kettle was fixed, deionized water, trifluoroethyl methacrylate (1%), sodium bicarbonate solution, seed emulsion (1.5%) and EDTA (0.03%) were added into the reaction kettle, free oxygen in the system was removed by vacuuming, stirring was started, the temperature was raised to 85°C, and then methyl methacrylate (13%), butyl acrylate (34%), β-hydroxypropyl methacrylate (34%) and methyl methacrylate (34%) were added dropwise. (1.5%), acrylonitrile (1%), N-hydroxymethyl acrylamide solution, anionic nonionic emulsifier (2%) and ammonium persulfate aqueous solution are added. During the dropping process, the temperature fluctuation is controlled not to exceed 1.5°C, the dropping rate is controlled, and the dropping is completed in 3 hours. After the addition is completed, the mixture is kept warm for 2 hours, then cooled to 30°C, and 15% sodium hydroxide solution (0.3%) is added. The pH is adjusted to 7-9, and then a preservative and a defoaming agent are added. The mixture is vacuumed for 30 minutes, stirring and heating are stopped, and the mixture is filtered with a 120-mesh filter to obtain a modified acrylic ester emulsion. The total amount of deionized water involved in the formula is 45.49%.

[0075] In this embodiment, the preparation method of emulsified modified asphalt includes the following steps:

[0076] 600g of 70# asphalt was added to a 500ml stainless steel container, and the asphalt was first heated to 140°C, and after being completely melted, it was stirred for 30 minutes for dehydration treatment at a speed of 400r / min, and then 3% of fluorinated polymer microspheres were added and stirred and dispersed for 2h, and then 3% of γ-glycidyloxypropyltrimethoxysilane was added and stirred and dispersed for 2h at a speed of 400r / min, thereby completing the modification of the asphalt to obtain modified asphalt;

[0077] 8g of anionic emulsifier, 4g of nonionic emulsifier and 2g of stabilizer are prepared into 400g of emulsifier aqueous solution, the pH is adjusted to 10-11, and heated to 60°C for use; the preheated emulsifier aqueous solution is added to the opened colloid mill, and then the preheated 140°C modified asphalt is evenly poured into the colloid mill, and the machine is stopped after emulsification for 3 minutes, the emulsified asphalt is cooled to room temperature, and filtered with a 120-mesh filter to obtain emulsified modified asphalt.

[0078] The method for preparing fluorinated polymer microspheres comprises the following steps:

[0079] First, 40g of dodecafluoroheptyl methacrylate (DFHMA), 3.55g of acrylic acid glycidyl ether, 0.5g of azobisisobutyronitrile, 4.5g of dispersant PVP-K30, 370g of anhydrous ethanol and 30g of deionized water were added to a three-necked round-bottom flask, and nitrogen was then bubbling into the system for 30 minutes, and nitrogen was continuously introduced to stir the reaction in a 75°C oil bath for 2 hours. The resulting product was then washed with ethanol and centrifuged at 3000r / min to remove the dispersant and unreacted monomers. The above steps were repeated, and the centrifuged product was finally dried in a vacuum oven at 50°C for 24 hours to obtain fluorinated polymer microspheres.

[0080] Example 2

[0081] A fluorosilicone modified asphalt waterproof coating, comprising the following components by mass percentage:

[0082] Modified acrylic emulsion 30%, emulsified modified asphalt 30%, defoamer 0.3%, bactericide 0.3%, dispersant 0.2%, wetting agent 0.2%, thickener 0.3%, 1250 mesh heavy calcium 10%, 3000 mesh silica powder 10%, 3000 mesh precipitated barium sulfate 10%, and water 8.7%.

[0083] Wherein, the preparation method of modified acrylic ester emulsion and emulsified modified asphalt is the same as that in Example 1.

[0084] Example 3

[0085] A fluorosilicone modified asphalt waterproof coating, comprising the following components by mass percentage:

[0086] Modified acrylic emulsion 40%, emulsified modified asphalt 20%, defoamer 0.3%, bactericide 0.3%, dispersant 0.2%, wetting agent 0.2%, thickener 0.3%, 1250 mesh heavy calcium 10%, 3000 mesh silica powder 10%, 3000 mesh precipitated barium sulfate 10%, and water 8.7%.

[0087] Wherein, the preparation method of modified acrylic ester emulsion and emulsified modified asphalt is the same as that in Example 1.

[0088] Example 4

[0089] This embodiment is a method for preparing the fluorosilicone modified asphalt waterproof coating of Embodiment 1-3, comprising the following steps:

[0090] The components are mixed evenly according to proportion to obtain a fluorosilicone modified asphalt waterproof coating.

[0091] Comparative Example 1

[0092] An asphalt waterproof coating comprises the following components by mass percentage:

[0093] Commercially available styrene acrylic emulsion FS-698Y 40%, commercially available emulsified asphalt DS-1 20%, defoamer 0.3%, fungicide 0.3%, dispersant 0.2%, wetting agent 0.2%, thickener 0.3%, 1250 mesh heavy calcium 10%, 3000 mesh silica powder 10%, 3000 mesh precipitated barium sulfate 10%, and water 8.7%.

[0094] The components are mixed evenly according to proportion to obtain an asphalt waterproof coating.

[0095] Comparative Example 2

[0096] An asphalt waterproof coating comprises the following components by mass percentage:

[0097] 40% of commercial modified acrylic emulsion 5592, 20% of commercial emulsified asphalt DS-1, 0.3% of defoamer, 0.3% of fungicide, 0.2% of dispersant, 0.2% of wetting agent, 0.3% of thickener, 10% of 1250 mesh heavy calcium, 10% of 3000 mesh silica powder, 10% of 3000 mesh precipitated barium sulfate, and 8.7% of water.

[0098] The components are mixed evenly according to proportion to obtain an asphalt waterproof coating.

[0099] Comparative Example 3

[0100] An asphalt waterproof coating comprises the following components by mass percentage:

[0101] 40% of commercial styrene-butadiene latex Lipaton SB-60B11, 20% of commercial emulsified asphalt DS-1, 0.3% of defoamer, 0.3% of fungicide, 0.2% of dispersant, 0.2% of wetting agent, 0.3% of thickener, 10% of 1250 mesh heavy calcium, 10% of 3000 mesh silica powder, 10% of 3000 mesh precipitated barium sulfate, and 8.7% of water.

[0102] The components are mixed evenly according to proportion to obtain an asphalt waterproof coating.

[0103] Comparative Example 4

[0104] An asphalt waterproof coating comprises the following components by mass percentage:

[0105] Chloroprene latex Lipern B-2207 40%, commercially available emulsified asphalt DS-1 20%, defoamer 0.3%, fungicide 0.3%, dispersant 0.2%, wetting agent 0.2%, thickener 0.3%, 1250 mesh heavy calcium 10%, 3000 mesh silica powder 10%, 3000 mesh precipitated barium sulfate 10%, and water 8.7%.

[0106] The components are mixed evenly according to proportion to obtain an asphalt waterproof coating.

[0107] Comparative Example 5

[0108] The difference between this comparative example and Example 1 is that β-hydroxypropyl methacrylate is not added in the preparation process of the modified acrylate emulsion, and methyl methacrylate is used to make up the difference to obtain the corresponding modified acrylate emulsion;

[0109] The remaining components and their proportions are the same as those in Example 1 to obtain an asphalt waterproof coating.

[0110] Compared with Example 1, the defects of the asphalt waterproof coating in this comparative example are that its tensile properties, chemical resistance, adhesion and water resistance are all poor.

[0111] Comparative Example 6

[0112] The difference between this comparative example and Example 1 is that acrylonitrile is not added during the preparation of the modified acrylic ester emulsion, and methyl methacrylate is used to make up the difference to obtain the corresponding modified acrylic ester emulsion;

[0113] The remaining components and their proportions are the same as those in Example 1 to obtain an asphalt waterproof coating.

[0114] Compared with Example 1, the defects of the asphalt waterproof coating in this comparative example are that its tensile properties, chemical resistance and adhesion are all poor.

[0115] Comparative Example 7

[0116] The difference between this comparative example and Example 1 is that N-hydroxymethyl acrylamide is not added during the preparation of the modified acrylic ester emulsion, and methyl methacrylate is used to make up the difference to obtain the corresponding modified acrylic ester emulsion;

[0117] The remaining components and their proportions are the same as those in Example 1 to obtain an asphalt waterproof coating.

[0118] Compared with Example 1, the defects of the asphalt waterproof coating in this comparative example are that its tensile properties, chemical resistance, adhesion and water resistance are all poor.

[0119] Comparative Example 8

[0120] The difference between this comparative example and Example 1 is that trifluoroethyl methacrylate is not added during the preparation of the modified acrylate emulsion, and methyl methacrylate is used to make up the difference to obtain the corresponding modified acrylate emulsion;

[0121] The remaining components and their proportions are the same as those in Example 1 to obtain an asphalt waterproof coating.

[0122] Compared with Example 1, the defect of the asphalt waterproof coating in this comparative example is that its chemical stability, weather resistance and water resistance are all poor.

[0123] Comparative Example 9

[0124] The difference between this comparative example and Example 1 is that no fluorine-containing polymer microspheres are added during the preparation of the emulsified modified asphalt to obtain the corresponding emulsified modified asphalt;

[0125] The remaining components and their proportions are the same as those in Example 1 to obtain an asphalt waterproof coating.

[0126] Compared with Example 1, the defects of the asphalt waterproof coating in this comparative example are that its tensile properties, chemical stability, weather resistance, low temperature resistance, water resistance and adhesion are all poor.

[0127] Comparative Example 10

[0128] The difference between this comparative example and Example 1 is that γ-glycidyloxypropyltrimethoxysilane is not added during the preparation of the emulsified modified asphalt to obtain the corresponding emulsified modified asphalt;

[0129] The remaining components and their proportions are the same as those in Example 1 to obtain an asphalt waterproof coating.

[0130] Compared with Example 1, the defects of the asphalt waterproof coating in this comparative example are that its tensile properties, chemical stability, weather resistance, high and low temperature resistance, water resistance and adhesion are all poor.

[0131] Test example

[0132] The properties of the asphalt waterproof coatings of Examples 1-3 and Comparative Examples 1-10 are shown in Tables 1 and 2.

[0133] Specimen preparation and test methods:

[0134] (1) The solid content, heat resistance, impermeability, surface drying, actual drying time, low temperature temperature, tensile strength, elongation at break, and water absorption of the test pieces shall be prepared, cured, and tested in accordance with GB / T 16777-2008. The tensile speed for tensile strength and elongation at break shall be 500 mm / min.

[0135] (2) The bonding strength between coating and cement concrete shall be tested in accordance with JC / T 975-2005;

[0136] (3) Artificial weathering: The test specimens were placed under standard test conditions for 4 h after artificial weathering according to 6.21 of JC / T 864-2023. The appearance was visually observed and the low temperature temperature was measured according to 13.2.6 of GB / T 16777-2008.

[0137] Table 1

[0138]

[0139] Table 2

[0140]

[0141] In summary, the fluorosilicone modified asphalt waterproof coatings of Examples 1-3 of the present invention can effectively take into account high and low temperature resistance, weather resistance, water resistance, chemical stability, strength and adhesion, and are therefore helpful in reducing the risks associated with direct outdoor use. The comprehensive performance is significantly better than the asphalt waterproof coatings of Comparative Examples 1-10.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 fluorosilicone modified asphalt waterproof coating, characterized in that: Includes the following components: Modified acrylic emulsion and emulsified modified asphalt; The modified acrylic emulsion is prepared by seed emulsion polymerization of methyl methacrylate, butyl acrylate, trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile; The modified asphalt includes asphalt modified by fluorine-containing polymer microspheres and gamma-glycidyloxypropyltrimethoxysilane.

2. The fluorosilicone modified asphalt waterproof coating according to claim 1, characterized in that: The weight ratio of the methyl methacrylate, butyl acrylate, trifluoroethyl methacrylate, β-hydroxypropyl methacrylate, N-hydroxymethyl acrylamide and acrylonitrile is (11-15): (31-37.5): (0.25-2): (0.5-2.5): (0.5-2): (0.25-2).

3. The fluorosilicone modified asphalt waterproof coating according to claim 1, characterized in that: The fluorine-containing polymer microspheres are prepared by dispersion polymerization of dodecafluoroheptyl methacrylate, glycidyl acrylate and azobisisobutyronitrile in a dispersion medium.

4. The fluorosilicone modified asphalt waterproof coating according to claim 3, characterized in that: The dispersion medium includes ethanol and water.

5. The fluorosilicone modified asphalt waterproof coating according to claim 1, characterized in that: The preparation method of the modified asphalt comprises the following steps: The asphalt is melted and then dehydrated, and then fluorine-containing polymer microspheres and gamma-glycidyloxypropyltrimethoxysilane are added for dispersion to obtain modified asphalt.

6. The fluorosilicone modified asphalt waterproof coating according to claim 5, characterized in that: The added amount of the fluorine-containing polymer microspheres is 2%-5% of the weight of the asphalt.

7. The fluorosilicone modified asphalt waterproof coating according to claim 5, characterized in that: The added amount of the γ-glycidyloxypropyltrimethoxysilane is 2%-5% of the weight of the asphalt.

8. The fluorosilicone modified asphalt waterproof coating according to any one of claims 1 to 7, characterized in that: The components also include at least one of heavy calcium, silicon powder and barium sulfate.

9. A method for preparing the fluorosilicone modified asphalt waterproof coating according to any one of claims 1 to 8, characterized in that: The following steps are involved: The components are mixed to obtain the fluorosilicone modified asphalt waterproof coating.

10. Use of the fluorosilicone modified asphalt waterproof coating according to any one of claims 1 to 8 in engineering waterproofing.

Images