Inorganic alkali-resistant waterproof material and preparation method thereof

Abstract

The invention discloses an inorganic alkali-resistant waterproof material and a preparation method thereof, and belongs to the technical field of waterproof materials. The inorganic alkali-resistant waterproof material prepared by the invention is prepared from the following raw material components in parts by mass: 45 to 48 parts of quartz sand, 15 to 20 parts of sulphoaluminate cement, 2 to 4 parts of slaked lime, 20 to 25 parts of polymer emulsion, 6 to 10 parts of mineral powder, 7 to 12 parts of coal ash, 4 to 8 parts of sodium silicate, 3 to 5 parts of silica fume, 4.5 to 7.8 parts of composite colloidal particles and 0.18 to 0.35 part of early strength agent. Wherein the polymer emulsion is obtained by adopting an emulsion polymerization method to copolymerize acrylate, acrylamide, hydroxyethyl acrylate and 1-dimethylamino-allyl phosphonic acid and then adopting carboxyl PEG maleimide to modify; the composite colloidal particles are obtained by sequentially adding stearic acid, zinc oxide, a mixture of polyethylene glycol and MDI, carbon black N550, an acrylamide copolymer, modified polyurethane, a pore-forming agent and the like into plasticized hydrogenated butadiene-acrylonitrile rubber, mixing, extruding, granulating, forming pores, and compounding with modified silicon dioxide microspheres.

Description

Technical Field

[0001] The invention relates to an inorganic alkali-resistant and waterproof material and a preparation method thereof. Background Art

[0002] With the rapid development of the construction industry, the requirements for building material performance are becoming increasingly stringent. As an integral part of construction projects, the quality of waterproofing materials is directly related to the lifespan and safety of buildings. However, traditional waterproofing materials have exposed a series of problems in practical applications, mainly including insufficient bond strength and poor waterproofing performance. These problems seriously affect the waterproofing effect and durability of buildings.

[0003] Traditional waterproofing materials are mostly made of organic or simple inorganic materials. While these materials can meet basic waterproofing requirements to a certain extent, they are prone to aging and cracking over time, leading to waterproofing failure. This is especially true for projects with highly alkaline environments, such as basements and tunnels. Due to the long-term exposure to damp and alkaline conditions, the limitations of traditional waterproofing materials are even more pronounced. Their insufficient alkali resistance makes them susceptible to erosion and loss of effectiveness.

[0004] Furthermore, while some existing waterproof materials improve their performance by adding various additives, they are often difficult to widely promote due to complex construction processes and high costs. Therefore, it is particularly important to develop a waterproof material with excellent alkali resistance, high bonding strength, and good waterproofing effect. Summary of the Invention

[0005] The purpose of the present invention is to provide an inorganic alkali-resistant waterproof material and a preparation method thereof, so as to solve the technical problems mentioned in the above background technology.

[0006] The technical solution for achieving the purpose of the present invention is: In a first aspect, the present invention provides an inorganic alkali-resistant waterproof material, wherein the inorganic alkali-resistant waterproof material comprises, by weight, raw material components including 45-48 parts by weight of quartz sand, 15-20 parts by weight of sulphoaluminate cement, 2-4 parts by weight of slaked lime, 20-25 parts by weight of polymer emulsion, 6-10 parts by weight of mineral powder, 7-12 parts by weight of fly ash, 4-8 parts by weight of sodium silicate, 3-5 parts by weight of silica fume, 4.5-7.8 parts by weight of composite colloid particles, and 0.18-0.35 parts by weight of early strength agent.

[0007] Furthermore, the polymer emulsion is obtained by copolymerizing acrylic acid, acrylamide, maleimide-PEG-acrylamide, hydroxyethyl acrylate, isooctyl acrylate, and 1-dimethylamino-allylphosphonic acid through emulsion polymerization.

[0008] Furthermore, the composite rubber particles are obtained by embedding modified silica microspheres in porous water-swelling rubber.

[0009] Furthermore, the modified silica microspheres are prepared by partially hydrolyzing hydrophobic silica microspheres and then grafting mercaptosiloxane oligomers onto their surfaces.

[0010] Furthermore, the porous water-swellable rubber is obtained by mixing, extruding, granulating and forming pores of plasticized hydrogenated nitrile rubber, stearic acid, zinc oxide, a mixture of polyethylene glycol and MDI, carbon black N550, acrylamide copolymer, allyl polyurethane, vulcanizing agent, co-vulcanizing agent and pore-forming agent.

[0011] In a second aspect, the present invention provides a method for preparing the inorganic alkali-resistant waterproof material as described in the first aspect, comprising the following preparation steps: (1) Weigh and prepare the raw materials according to the corresponding mass fractions of each raw material component; (2) Drying quartz sand, sulphoaluminate cement, slaked lime, mineral powder, fly ash and silica fume; (3) After the sodium silicate and sulphoaluminate cement are evenly mixed, quartz sand, slaked lime, mineral powder, fly ash, and silica fume are added and the mixture is stirred for 10 to 15 minutes to obtain a dry mix. The sulphoaluminate cement and sodium silicate are pre-mixed to avoid agglomeration. (4) Slowly add polymer emulsion and composite particles to the dry mix and stir for 20-30 minutes to form a uniform slurry; (5) Add an early strength agent to the uniform slurry and stir for 5 minutes to obtain an inorganic alkali-resistant waterproof material.

[0012] Furthermore, the preparation method of the polymer emulsion is as follows: 6 parts by mass of acrylic acid, 2 parts by mass of acrylamide, 2 to 4 parts by mass of maleimide-PEG-acrylamide, 0.2 to 0.4 parts by mass of hydroxyethyl acrylate, 0.02 parts by mass of isooctyl acrylate, 0.8 to 1.2 parts by mass of 1-dimethylamino-allylphosphonic acid, 4 parts by mass of emulsifier, and 40 parts by mass of pure water are mixed and stirred until fully emulsified and dissolved, the pH is adjusted to 7, nitrogen is introduced to exclude air, the mixture is heated to 40 to 50° C., 4 to 4.5 parts by mass of initiator ammonium persulfate are added, and the mixture is reacted at a constant temperature for 7.5 to 8.5 hours to obtain a polymer emulsion.

[0013] Furthermore, the preparation method of the composite colloidal particles is: 10 parts by mass of modified silica microspheres are mixed with 90 parts by mass of ethyl acetate, ultrasonically dispersed for 30 minutes, then 60 parts by mass of porous water-absorbing and swelling rubber are added, ultrasonication is continued for 50 to 70 minutes, then filtered after standing for 2 to 4 hours, placed in a vacuum drying oven at 80°C and dried for at least 12 hours, then taken out and stood in the air for at least 24 hours to obtain composite colloidal particles.

[0014] Furthermore, the preparation method of the porous water-swellable rubber is as follows: (1) The preparation steps of acrylamide copolymer are as follows: 6 parts by mass of acrylamide, 0.8-1.2 parts by mass of acrylamide polyethylene glycol thiol, and 1-3 parts by mass of furfuryl methacrylate are added to DMF and stirred to dissolve, then nitrogen is introduced to exclude air, 0.14-0.18 parts by mass of initiator ammonium persulfate is added, and the mixture is heated to 40-50°C and reacted at a constant temperature for 3-4 hours, followed by repeated washing with ethanol 2-4 times and drying to obtain acrylamide copolymer; (2) 100 parts by mass of hydrogenated nitrile rubber were placed on a clean and dry open mill for plasticizing for 1-2 minutes, and then 1-2 parts by mass of stearic acid, 3-5 parts by mass of zinc oxide, 30-50 parts by mass of a mixture of polyethylene glycol and 6 parts by mass of diphenylmethane diisocyanate, 25-35 parts by mass of carbon black N550, 30-50 parts by mass of acrylamide copolymer, and 53-55 parts by mass of allyl polyurethane were added in sequence and mixed evenly. Then, 1.5-2.5 parts by mass of vulcanizing agent diisopropyl peroxide, 0.5-1 parts by mass of co-vulcanizing agent TAIC, and 32-34 parts by mass of pore-forming agent were added and mixed again. After being placed at room temperature for 24 hours, the mixture was put into a twin-screw extruder for extrusion and granulation, and then soaked in deionized water for 2-3 times. Fresh deionized water was replaced before each soaking, and each soaking time was 8-12 hours to obtain a porous water-absorbing and swelling rubber.

[0015] Furthermore, the preparation method of the modified silica microspheres is as follows: acetic acid is added dropwise under stirring to adjust the pH value of 300 parts by mass of deionized water to 4-5, and then an anhydrous ethanol solution containing 2 wt% 3-mercaptopropyltriethoxysilane in an amount of 1 / 3 times the volume of deionized water is added, and stirring is continued for 8-12 minutes to obtain a mercaptosiloxane oligomer, and then 10 parts by mass of hydrophobic silica microspheres are added, ultrasonically dispersed for 30 minutes, and continuously stirred at 49-51°C for 3.8-4.2 hours, centrifuged, and used A mixed solution of ethanol and deionized water in a mass ratio of 1:1 was centrifuged and washed twice, and then centrifuged and washed once with anhydrous ethanol, and dried in an oven at 54-56°C for 23-25 ​​hours to obtain modified silica microspheres; the modified silica microspheres were prepared by partially hydrolyzing the hydrophobic groups on the surface of the hydrophobic silica microspheres to form hydroxyl groups, which then formed hydrogen bonds with the silanol groups of the mercaptosiloxane oligomers and then dehydrated and condensed to form Si-O-Si bonds, forming mercapto groups on part of the surface of the silica microspheres, and the remaining surface was all hydrophobic groups.

[0016] When the inorganic alkali-resistant waterproof material is used, the inorganic alkali-resistant waterproof material is first coated on the surface of the substrate with a thickness of 1.5-2.0 mm, and then naturally cured for 24 hours and then wet-cured for 7 days at 20-25° C. and humidity ≥90%.

[0017] By adopting the above technical solution, the present invention has the following beneficial effects: (1) The inorganic alkali-resistant waterproof material of the present invention comprises, by weight, 45-48 parts of quartz sand, 15-20 parts of sulfoaluminate cement, 2-4 parts of slaked lime, 20-25 parts of polymer emulsion, 6-10 parts of mineral powder, 7-12 parts of fly ash, 4-8 parts of sodium silicate, 3-5 parts of silica fume, 4.5-7.8 parts of composite colloid particles, and 0.18-0.35 parts of early strength agent. The inorganic alkali-resistant waterproof material prepared has high bonding strength, good alkali resistance, and excellent alkali-proof effect.

[0018] (2) The polymer emulsion of the present invention works synergistically with sulphoaluminate cement to provide better bonding strength.

[0019] (3) The sodium silicate of the present invention can be used as an alkali activator to form a dense calcium silicate gel with good alkali resistance.

[0020] (4) The inorganic alkali-resistant waterproof material of the present invention can be directly applied and is suitable for wet base surfaces.

[0021] (5) No organic solvent is added to the raw material components of the inorganic alkali-resistant waterproof material of the present invention, and the VOC content complies with the GB18582-2020 standard.

[0022] (6) The polymer emulsion of the present invention is obtained by copolymerizing acrylic acid, acrylamide, maleimide-PEG-acrylamide, hydroxyethyl acrylate, isooctyl acrylate, and 1-dimethylamino-allylphosphonic acid by emulsion polymerization. The molecular side chain length of the polymer is increased by introducing long-chain maleimide-PEG-acrylamide. The polymer chain with long side chains can penetrate into the interface of the adhered substrate and then form chain entanglement with the surface molecular layer of the adhered substrate, thereby forming interfacial adhesion, thereby increasing the bonding strength of the inorganic alkali-resistant waterproof material; at the same time, the bonding strength between the polymer chain and the substrate can be further enhanced by introducing active groups such as hydroxyl groups and phosphate groups.

[0023] (7) The composite particles of the present invention can effectively enhance the elasticity of the material and reduce shrinkage cracks.

[0024] (8) The composite rubber particles of the present invention are obtained by embedding modified silica microspheres in porous water-absorbing and swelling rubber; wherein the porous water-absorbing and swelling rubber is obtained by mixing and extruding plasticized hydrogenated nitrile rubber, stearic acid, zinc oxide, a mixture of polyethylene glycol and MDI, carbon black N550, acrylamide copolymer, allyl polyurethane, vulcanizing agent, vulcanizing agent, pore-forming agent, granulating and forming pores; acrylamide copolymer is obtained by copolymerizing acrylamide, acrylamide polyethylene glycol thiol and furfuryl methacrylate; MDI is used as chain extender The agent grafts acrylamide copolymer and polyethylene glycol together to form an interpenetrating cross-linked network composed of repeating chain segments - acrylamide copolymer - MDI - polyethylene glycol - and the molecular chain of the rubber matrix. Allyl polyurethane is grafted onto the double bonds on the main chain of the rubber molecule through allyl groups, and is grafted through the counter-reaction of isocyanate and acrylamide copolymer to prevent polyethylene glycol, acrylamide copolymer, and allyl polyurethane from precipitating from the rubber matrix, affecting the expansion stability of the water-swelling rubber. The polyethylene glycol in the cross-linked network of the water-swelling rubber , acrylamide copolymer, and allyl polyurethane continuously absorb water molecules to expand the volume of the water-absorbing and swelling rubber. The volume expansion causes the network molecular chains of the rubber matrix to expand outward and causes its cross-linking structure to deform. The rubber matrix with excellent elastic properties will simultaneously produce a binding force to inhibit the outward expansion of the molecular chains. In the early stage of expansion, the water-absorbing and swelling force of the water-absorbing and swelling rubber is much greater than the shrinkage force that resists deformation. Polyethylene glycol, acrylamide copolymer, and allyl polyurethane can absorb a large amount of water, causing the volume expansion ratio of the water-absorbing and swelling rubber to continue to increase; modified silica microspheres are embedded in the porous water-absorbing and swelling rubber through the pores, and then cross-linked through the thiol groups on the surface and the thiol groups in the porous water-absorbing and swelling rubber. When the composite particles are added to the inorganic alkali-resistant waterproof material, the composite particles absorb water and swell to squeeze the pores on the surface of the composite particles. The pores are squeezed and tightened to squeeze the hydrophobic part of the surface of the modified silica microspheres out of the porous water-absorbing and swelling rubber, forming a micron-level hydrophobic papillary structure on the surface of the composite particles, thereby enhancing the waterproof performance of the inorganic alkali-resistant waterproof material.

[0025] (8) After the components of the inorganic alkali-resistant waterproof material are mixed, the composite colloid particles absorb water and swell, so that the composite colloid particles are fully in contact with the polymer molecular chains. The furan groups on the composite colloid particles react with the maleimide of the polymer molecular chains to form DA cross-linking, and the composite colloid particles are firmly and evenly dispersed in the inorganic alkali-resistant waterproof material. This prevents the agglomeration of the rubber powder from affecting the mechanical properties of the inorganic alkali-resistant waterproof material, while increasing the toughness of the inorganic alkali-resistant waterproof material.

[0026] (9) After the components of the inorganic alkali-resistant waterproof material are mixed, the slaked lime reacts with the phosphoric acid in the polymer molecular chain to form insoluble calcium phosphate, which can effectively improve the density and hardness of the inorganic alkali-resistant waterproof material and effectively increase the waterproof and anti-seepage performance of the inorganic alkali-resistant waterproof material. DETAILED DESCRIPTION

[0027] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0028] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0029] The following examples are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0030] Some of the raw materials of the embodiments of the present invention and the comparative examples are as follows: Hydrophobic silica microspheres: 2 parts by mass of silica microspheres with a D50 of 20 μm were heated to 120°C, mixed with ethanol, and ultrasonically dispersed for 30 minutes to prepare a 4.8 wt% silica microsphere dispersion; then, 6 parts by mass of dimethyldichlorosilane were added, and 1.2 parts by mass of water were added at a rate of 3 seconds per drop. The mixture was then refluxed at 130°C for 50 minutes, followed by centrifugal washing four times with ethanol and drying to constant weight to obtain hydrophobic silica microspheres.

[0031] Pore-forming agent: 450 mesh potassium chloride.

[0032] Acrylamide polyethylene glycol thiol: SH-PEG-ACA, molecular weight of 2000.

[0033] Maleimide-PEG-acrylamide: Mal-PEG-AcA, molecular weight 2000 The polyethylene glycol used was polyethylene glycol-4000.

[0034] The preparation method of 1-dimethylamino-allylphosphonic acid is as follows: dimethylamine and phosphorous acid are mixed, and 1M dilute hydrochloric acid is added dropwise at a rate of 3 seconds until the pH reaches 1. After the addition is complete, acrolein is slowly added dropwise from room temperature to 85°C. After the addition is complete, the reaction is continued for 2 hours to terminate the reaction. The molar ratio of dimethylamine to phosphorous acid to acrolein is 1:1:1. The reaction mechanism is as follows: .

[0035] The preparation steps of allyl polyurethane are as follows: stir the polyether PU prepolymer at a constant temperature of 50°C for 30 minutes; after stirring evenly, add hydroxyethyl acrylate into the flask at a rate of 2s / min, the molar ratio of hydroxyethyl acrylate to the isocyanate of the polyether PU prepolymer is 1:2, and react at a constant temperature for 4 hours to obtain allyl polyurethane. Example 1

[0036] A method for preparing an inorganic alkali-resistant waterproof material comprises the following steps: (1) Weigh and prepare the following raw materials according to the corresponding parts by mass: 45 parts by mass of quartz sand, 15 parts by mass of sulphoaluminate cement, 2 parts by mass of slaked lime, 20 parts by mass of polymer emulsion, 6 parts by mass of mineral powder, 7 parts by mass of fly ash, 4 parts by mass of sodium silicate, 3 parts by mass of silica fume, 4.5 parts by mass of composite granules, and 0.18 parts by mass of early strength agent; (2) Dry the weighed quartz sand, sulphoaluminate cement, slaked lime, mineral powder, fly ash and silica fume; (3) After the weighed sodium silicate and sulphoaluminate cement are mixed evenly, quartz sand, slaked lime, mineral powder, fly ash and silica fume are added and stirred at 1000 rpm for 10 minutes to obtain a dry mix; (4) Slowly add the polymer emulsion and composite particles to the dry mix and stir at 1500 rpm for 20 min to form a uniform slurry; (5) Add an early strength agent to the uniform slurry and stir at 80 rpm for 5 minutes to obtain an inorganic alkali-resistant waterproof material.

[0037] The preparation method of the polymer emulsion is as follows: 6 parts by mass of acrylic acid, 2 parts by mass of acrylamide, 2 parts by mass of maleimide-PEG-acrylamide, 0.2 parts by mass of hydroxyethyl acrylate, 0.02 parts by mass of isooctyl acrylate, 0.8 parts by mass of 1-dimethylamino-allylphosphonic acid, 4 parts by mass of emulsifier OP-10, and 40 parts by mass of pure water are mixed and stirred until fully emulsified and dissolved, the pH is adjusted to 7, nitrogen is introduced to exclude air, the mixture is heated to 40° C., 4 parts by mass of initiator ammonium persulfate are added, and the mixture is reacted at a constant temperature for 7.5 hours to obtain a polymer emulsion.

[0038] The composite colloid particles are prepared by mixing 10 parts by mass of modified silica microspheres with 90 parts by mass of ethyl acetate, performing ultrasonic dispersion for 30 minutes, then adding 60 parts by mass of porous water-swellable rubber, continuing ultrasonic dispersion for 50 minutes, then standing for 2 hours and filtering, placing in a vacuum drying oven at 80° C. and drying for at least 12 hours, then taking out and standing in the air for at least 24 hours to obtain the composite colloid particles.

[0039] The preparation method of the porous water-swellable rubber is as follows: (1) The preparation steps of acrylamide copolymer are as follows: 6 parts by mass of acrylamide, 0.8 parts by mass of acrylamide polyethylene glycol thiol, and 1 part by mass of furfuryl methacrylate are added to DMF and stirred to dissolve, then nitrogen is introduced to remove air, 0.14 parts by mass of initiator ammonium persulfate is added, and the mixture is heated to 40°C and kept at this temperature for 3 hours, followed by repeated washing with ethanol twice and drying to obtain acrylamide copolymer; (2) 100 parts by mass of hydrogenated nitrile rubber were placed on a clean and dry open mill and plasticized for 1 minute. Then, 1 part by mass of stearic acid, 3 parts by mass of zinc oxide, a mixture of 30 parts by mass of polyethylene glycol and 6 parts by mass of diphenylmethane diisocyanate, 25 parts by mass of carbon black N550, 30 parts by mass of acrylamide copolymer, and 53 parts by mass of allyl polyurethane were added in sequence and mixed evenly. Then, 1.5 parts by mass of vulcanizing agent diisopropyl peroxide, 0.5 parts by mass of co-vulcanizing agent TAIC, and 32 parts by mass of pore-forming agent were added and mixed again. After being placed at room temperature for 24 hours, the rubber was extruded into pellets in a twin-screw extruder and then soaked in deionized water twice. Fresh deionized water was replaced before each soaking. The soaking time was 8 hours each time to obtain a porous water-absorbing and swelling rubber. The temperature of the twin-screw extruder was 140-170°C, the feeding frequency was 22 Hz, and the main engine speed was 90 r / min.

[0040] The preparation method of the modified silica microspheres is as follows: acetic acid is added dropwise under stirring to adjust the pH value of 300 parts by mass of deionized water to 4, then an anhydrous ethanol solution containing 2wt% 3-mercaptopropyltriethoxysilane in an amount 1 / 3 times the volume of the deionized water is added, and stirring is continued for 8 minutes to obtain a mercaptosiloxane oligomer, followed by adding 10 parts by mass of hydrophobic silica microspheres, ultrasonically dispersing for 30 minutes, continuously stirring at 49°C for 3.8 hours, centrifuging, and washing twice with a mixed solution of ethanol and deionized water in a mass ratio of 1:1, and then washing once with anhydrous ethanol, and drying in an oven at 54°C for 23 hours to obtain the modified silica microspheres.

[0041] When the inorganic alkali-resistant waterproof material is used, the inorganic alkali-resistant waterproof material is first coated on the surface of the substrate with a thickness of 2 mm, and then naturally cured for 24 hours and then wet-cured for 7 days at 25° C. and humidity ≥90%. Example 2

[0042] A method for preparing an inorganic alkali-resistant waterproof material comprises the following steps: (1) Weigh and prepare the following raw materials according to the corresponding parts by mass: 48 parts by mass of quartz sand, 18 parts by mass of sulphoaluminate cement, 3 parts by mass of slaked lime, 22 parts by mass of polymer emulsion, 8 parts by mass of mineral powder, 10 parts by mass of fly ash, 6 parts by mass of sodium silicate, 4 parts by mass of silica fume, 6 parts by mass of composite colloidal particles, and 0.27 parts by mass of early strength agent; (2) Dry the weighed quartz sand, sulphoaluminate cement, slaked lime, mineral powder, fly ash and silica fume; (3) After the weighed sodium silicate and sulphoaluminate cement are evenly mixed, quartz sand, slaked lime, mineral powder, fly ash and silica fume are added and stirred at 1000 rpm for 13 minutes to obtain a dry mix; (4) Slowly add the polymer emulsion and composite particles to the dry mix and stir at 1500 rpm for 25 min to form a uniform slurry; (5) Add an early strength agent to the uniform slurry and stir at 80 rpm for 5 minutes to obtain an inorganic alkali-resistant waterproof material.

[0043] The preparation method of the polymer emulsion is as follows: 6 parts by mass of acrylic acid, 2 parts by mass of acrylamide, 3 parts by mass of maleimide-PEG-acrylamide, 0.3 parts by mass of hydroxyethyl acrylate, 0.02 parts by mass of isooctyl acrylate, 1 part by mass of 1-dimethylamino-allylphosphonic acid, 4 parts by mass of emulsifier OP-10, and 40 parts by mass of pure water are mixed and stirred until fully emulsified and dissolved, the pH is adjusted to 7, nitrogen is introduced to exclude air, the mixture is heated to 45° C., 4.3 parts by mass of initiator ammonium persulfate is added, and the mixture is reacted at a constant temperature for 8 hours to obtain a polymer emulsion.

[0044] The composite colloid particles are prepared by mixing 10 parts by mass of modified silica microspheres with 90 parts by mass of ethyl acetate, performing ultrasonic dispersion for 30 minutes, then adding 60 parts by mass of porous water-swellable rubber, continuing ultrasonic dispersion for 60 minutes, then standing for 3 hours and filtering, placing in a vacuum drying oven at 80° C. and drying for at least 12 hours, then taking out and standing in air for at least 24 hours to obtain the composite colloid particles.

[0045] The preparation method of the porous water-swellable rubber is as follows: (1) The preparation steps of acrylamide copolymer are as follows: 6 parts by mass of acrylamide, 1 part by mass of acrylamide polyethylene glycol thiol, and 2 parts by mass of furfuryl methacrylate are added to DMF and stirred to dissolve, then nitrogen is introduced to remove air, 0.16 parts by mass of initiator ammonium persulfate is added, and the mixture is heated to 45°C and reacted at a constant temperature for 3.5 hours, followed by repeated washing with ethanol 3 times and drying to obtain acrylamide copolymer; (2) 100 parts by mass of hydrogenated nitrile rubber was placed on a clean and dry open mill and plasticized for 1.5 minutes. Then, 1.5 parts by mass of stearic acid, 4 parts by mass of zinc oxide, a mixture of 40 parts by mass of polyethylene glycol and 6 parts by mass of diphenylmethane diisocyanate, 30 parts by mass of carbon black N550, 40 parts by mass of acrylamide copolymer, and 54 parts by mass of allyl polyurethane were added in sequence and mixed evenly. Then, 2 parts by mass of vulcanizing agent diisopropyl peroxide, 0.8 parts by mass of co-vulcanizing agent TAIC, and 33 parts by mass of pore-forming agent were added and mixed again. After being placed at room temperature for 24 hours, the rubber was extruded into pellets in a twin-screw extruder and then soaked in deionized water for 3 times. Fresh deionized water was replaced before each soaking. The soaking time for each time was 12 hours to obtain a porous water-absorbing and swelling rubber. The temperature of the twin-screw extruder was 140-170°C, the feeding frequency was 22 Hz, and the main engine speed was 90 r / min.

[0046] The preparation method of the modified silica microspheres is as follows: acetic acid is added dropwise under stirring to adjust the pH value of 300 parts by mass of deionized water to 5, then an anhydrous ethanol solution containing 2wt% 3-mercaptopropyltriethoxysilane with a volume of 1 / 3 times the volume of the deionized water is added, and stirring is continued for 10 minutes to obtain a mercaptosiloxane oligomer, followed by adding 10 parts by mass of hydrophobic silica microspheres, ultrasonically dispersing for 30 minutes, continuously stirring at 50°C for 4 hours, centrifuging, and washing twice with a mixed solution of ethanol and deionized water with a mass ratio of 1:1, and then washing once with anhydrous ethanol, and drying in an oven at 55°C for 24 hours to obtain the modified silica microspheres.

[0047] When the inorganic alkali-resistant waterproof material is used, the inorganic alkali-resistant waterproof material is first coated on the surface of the substrate with a thickness of 2 mm, and then naturally cured for 24 hours and then wet-cured for 7 days at 25° C. and humidity ≥90%. Example 3

[0048] A method for preparing an inorganic alkali-resistant waterproof material comprises the following steps: (1) Weigh and prepare the following raw materials according to the corresponding parts by mass: 47 parts by mass of quartz sand, 20 parts by mass of sulphoaluminate cement, 4 parts by mass of slaked lime, 25 parts by mass of polymer emulsion, 10 parts by mass of mineral powder, 12 parts by mass of fly ash, 8 parts by mass of sodium silicate, 5 parts by mass of silica fume, 7.8 parts by mass of composite granules, and 0.35 parts by mass of early strength agent; (2) Dry the weighed quartz sand, sulphoaluminate cement, slaked lime, mineral powder, fly ash and silica fume; (3) After the weighed sodium silicate and sulphoaluminate cement are evenly mixed, quartz sand, slaked lime, mineral powder, fly ash and silica fume are added and stirred at 1000 rpm for 15 minutes to obtain a dry mix; (4) Slowly add the polymer emulsion and composite particles to the dry mix and stir at 1500 rpm for 30 min to form a uniform slurry; (5) Add an early strength agent to the uniform slurry and stir at 80 rpm for 5 minutes to obtain an inorganic alkali-resistant waterproof material.

[0049] The preparation method of the polymer emulsion is as follows: 6 parts by mass of acrylic acid, 2 parts by mass of acrylamide, 4 parts by mass of maleimide-PEG-acrylamide, 0.4 parts by mass of hydroxyethyl acrylate, 0.02 parts by mass of isooctyl acrylate, 1.2 parts by mass of 1-dimethylamino-allylphosphonic acid, 4 parts by mass of emulsifier OP-10, and 40 parts by mass of pure water are mixed and stirred until fully emulsified and dissolved, the pH is adjusted to 7, nitrogen is introduced to exclude air, the mixture is heated to 50° C., 4.5 parts by mass of initiator ammonium persulfate is added, and the mixture is reacted at a constant temperature for 8.5 hours to obtain a polymer emulsion.

[0050] The composite colloid particles are prepared by mixing 10 parts by mass of modified silica microspheres with 90 parts by mass of ethyl acetate, performing ultrasonic dispersion for 30 minutes, then adding 60 parts by mass of porous water-swellable rubber, continuing ultrasonic dispersion for 70 minutes, then standing for 4 hours and filtering, placing in a vacuum drying oven at 80° C. and drying for at least 12 hours, then taking out and standing in the air for at least 24 hours to obtain the composite colloid particles.

[0051] The preparation method of the porous water-swellable rubber is as follows: (1) The preparation steps of acrylamide copolymer are as follows: 6 parts by mass of acrylamide, 1.2 parts by mass of acrylamide polyethylene glycol thiol, and 3 parts by mass of furfuryl methacrylate are added to DMF and stirred to dissolve, then nitrogen is introduced to remove air, 0.18 parts by mass of initiator ammonium persulfate is added, and the mixture is heated to 50°C and kept at this temperature for 4 hours, followed by repeated washing with ethanol 4 times and drying to obtain acrylamide copolymer; (2) 100 parts by mass of hydrogenated nitrile rubber were placed on a clean and dry open mill for plasticizing for 2 minutes, and then 2 parts by mass of stearic acid, 5 parts by mass of zinc oxide, 50 parts by mass of a mixture of polyethylene glycol and 6 parts by mass of diphenylmethane diisocyanate, 35 parts by mass of carbon black N550, 50 parts by mass of acrylamide copolymer, and 55 parts by mass of allyl polyurethane were added in sequence and mixed evenly. Then, 2.5 parts by mass of vulcanizing agent diisopropyl peroxide, 1 part by mass of co-vulcanizing agent TAIC, and 34 parts by mass of pore-forming agent were added and mixed again. After being placed at room temperature for 24 hours, the rubber was extruded into pellets in a twin-screw extruder and then soaked in deionized water for 3 times. Fresh deionized water was replaced before each soaking. The soaking time for each time was 12 hours to obtain a porous water-absorbing and swelling rubber. The temperature of the twin-screw extruder was 140-170°C, the feeding frequency was 22 Hz, and the main engine speed was 90 r / min.

[0052] The preparation method of the modified silica microspheres is as follows: acetic acid is added dropwise under stirring to adjust the pH value of 300 parts by mass of deionized water to 5, then an anhydrous ethanol solution containing 2wt% 3-mercaptopropyltriethoxysilane in an amount 1 / 3 times the volume of the deionized water is added, and stirring is continued for 12 minutes to obtain a mercaptosiloxane oligomer, followed by adding 10 parts by mass of hydrophobic silica microspheres, ultrasonically dispersing for 30 minutes, continuously stirring at 51°C for 4.2 hours, centrifuging, and washing twice with a mixed solution of ethanol and deionized water in a mass ratio of 1:1, and then washing once with anhydrous ethanol, and drying in an oven at 56°C for 25 hours to obtain the modified silica microspheres.

[0053] When the inorganic alkali-resistant waterproof material is used, the inorganic alkali-resistant waterproof material is first coated on the surface of the substrate with a thickness of 2 mm, and then naturally cured for 24 hours and then wet-cured for 7 days at 25° C. and humidity ≥90%. Comparative Example 1

[0054] The difference between Comparative Example 1 and Example 2 is that the raw material components of the inorganic alkali-resistant waterproof material only include 48 parts by weight of quartz sand, 18 parts by weight of sulfoaluminate cement, 22 parts by weight of polymer emulsion, 8 parts by weight of mineral powder, 10 parts by weight of fly ash, 6 parts by weight of sodium silicate, 4 parts by weight of silica fume, 6 parts by weight of composite colloid, and 0.27 parts by weight of early strength agent. The remaining components and steps are the same as those in Example 2. Comparative Example 2

[0055] The difference between Comparative Example 2 and Example 2 is that the raw material components of the inorganic alkali-resistant waterproof material only include 48 parts by weight of quartz sand, 18 parts by weight of sulfoaluminate cement, 3 parts by weight of slaked lime, 22 parts by weight of polymer emulsion, 8 parts by weight of mineral powder, 10 parts by weight of fly ash, 6 parts by weight of sodium silicate, 4 parts by weight of silica fume, 5 parts by weight of rubber powder, and 0.27 parts by weight of early strength agent. The remaining components and steps are the same as those in Example 2. Comparative Example 3

[0056] The difference between Comparative Example 3 and Example 2 is that the polymer emulsion is obtained by copolymerizing only acrylic acid, acrylamide, hydroxyethyl acrylate, isooctyl acrylate, and 1-dimethylamino-allylphosphonic acid, and the other components and steps are the same as those in Example 2. Comparative Example 4

[0057] The difference between Comparative Example 4 and Example 2 is that the polymer emulsion is obtained by copolymerization of only acrylic acid, acrylamide, hydroxyethyl acrylate, isooctyl acrylate, and maleimide-PEG-acrylamide, and the other components and steps are the same as those in Example 2. Comparative Example 5

[0058] The difference between Comparative Example 5 and Example 2 is that the composite rubber particles are obtained by mixing the plasticized hydrogenated nitrile rubber, stearic acid, zinc oxide, a mixture of polyethylene glycol and MDI, carbon black N550, acrylamide copolymer, allyl polyurethane, vulcanizing agent, and co-vulcanizing agent, extruding and granulating them, and then mixing them with modified silica microspheres. The remaining components and steps are the same as those in Example 2. Comparative Example 6

[0059] The difference between Comparative Example 6 and Example 2 is that the composite rubber particles are porous water-swelling rubber, and the other components and steps are the same as those in Example 2. Effect Examples

[0060] Alkali resistance: The inorganic alkali-resistant waterproof material prepared in the examples and comparative examples was coated on the surface of the substrate in accordance with standard JC / T984-2011 with a thickness of 2 mm. After natural curing for 24 hours, it was wet-cured at 25°C and humidity ≥90% for 7 days. After the curing, it was immersed in 10% sodium hydroxide solution for 30 days, and the mass loss rate was calculated.

[0061] Table 1 below shows the performance data of the inorganic alkali-resistant waterproof materials prepared in Examples and Comparative Examples tested according to the standard JC / T984-2011: Table 1

[0062] As can be seen from Table 1 above, the inorganic alkali-resistant and waterproof materials prepared in Examples 1 to 3 have good bonding strength, good flexural strength, good waterproof and anti-permeability properties, and good alkali resistance.

[0063] The difference between Comparative Example 1 and Example 2 is that no slaked lime is added to the inorganic alkali-resistant waterproof material, and calcium phosphate cannot be formed in the inorganic alkali-resistant waterproof material, resulting in poor anti-seepage performance, flexural strength, and alkali resistance.

[0064] The difference between Comparative Example 2 and Example 2 is that the inorganic alkali-resistant waterproof material does not add composite rubber powder but uses conventional rubber powder. The bonding strength, waterproof and impermeability, and flexural strength of the inorganic alkali-resistant waterproof material are poor. The water-absorbing and swelling rubber also has a certain promoting effect on the increase of the bonding strength of the inorganic alkali-resistant waterproof material.

[0065] The difference between Comparative Example 3 and Example 2 is that the polymer emulsion does not adopt maleimide-PEG-acrylamide copolymerization, and the bonding strength and flexural strength of the obtained inorganic alkali-resistant waterproof material are poor.

[0066] The difference between Comparative Example 4 and Example 2 is that the polymer emulsion does not use 1-dimethylamino-allylphosphonic acid copolymerization, and the bonding strength, flexural strength, anti-seepage performance and alkali resistance of the inorganic alkali-resistant waterproof material prepared are worse than those of the inorganic alkali-resistant waterproof material prepared in the example.

[0067] The difference between Comparative Example 5 and Example 2 is that the composite particles use water-absorbing and swelling rubber instead of porous water-absorbing and swelling rubber and modified silica to compound, and the bonding strength and anti-permeability of the inorganic alkali-resistant waterproof material prepared are worse than those of the inorganic alkali-resistant waterproof material prepared in the example.

[0068] The difference between Comparative Example 6 and Example 2 is that the composite rubber particles use porous water-absorbing and swelling rubber, and the anti-seepage performance of the inorganic alkali-resistant waterproof material prepared without adding modified silica is worse than that of the inorganic alkali-resistant waterproof material prepared in the example.

[0069] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An inorganic alkali-resistant waterproof material, characterized in that: The inorganic alkali-resistant waterproof material comprises, by weight, raw material components including 45-48 parts by weight of quartz sand, 15-20 parts by weight of sulphoaluminate cement, 2-4 parts by weight of slaked lime, 20-25 parts by weight of polymer emulsion, 6-10 parts by weight of mineral powder, 7-12 parts by weight of fly ash, 4-8 parts by weight of sodium silicate, 3-5 parts by weight of silica fume, 4.5-7.8 parts by weight of composite colloid particles, and 0.18-0.35 parts by weight of an early strength agent.

2. The inorganic alkali-resistant waterproof material according to claim 1, characterized in that: The polymer emulsion is obtained by copolymerizing acrylic acid, acrylamide, maleimide-PEG-acrylamide, hydroxyethyl acrylate, isooctyl acrylate and 1-dimethylamino-allylphosphonic acid through an emulsion polymerization method.

3. The inorganic alkali-resistant waterproof material according to claim 1, characterized in that: The composite rubber particles are obtained by embedding modified silicon dioxide microspheres in porous water-absorbing and swelling rubber.

4. The inorganic alkali-resistant waterproof material according to claim 3, characterized in that: The modified silica microspheres are prepared by partially hydrolyzing hydrophobic silica microspheres and grafting mercaptosiloxane oligomers onto their surfaces.

5. The inorganic alkali-resistant waterproof material according to claim 3, characterized in that: The porous water-swelling rubber is obtained by mixing plasticized hydrogenated nitrile rubber, stearic acid, zinc oxide, a mixture of polyethylene glycol and MDI, carbon black N550, acrylamide copolymer, allyl polyurethane, a vulcanizing agent, a vulcanizing aid, and a pore-forming agent, extruding granulation, and forming pores.

6. A method for preparing the inorganic alkali-resistant waterproof material according to any one of claims 1 to 5, characterized in that: The method comprises the following preparation steps: (1) Weigh and prepare the raw materials according to the corresponding mass fractions of each raw material component; (2) Drying quartz sand, sulphoaluminate cement, slaked lime, mineral powder, fly ash and silica fume; (3) After evenly mixing sodium silicate and sulphoaluminate cement, add quartz sand, slaked lime, mineral powder, fly ash and silica fume and continue stirring for 10-15 minutes to obtain a dry mix; (4) Slowly add polymer emulsion and composite particles to the dry mix and stir for 20-30 minutes to form a uniform slurry; (5) Add an early strength agent to the uniform slurry and stir for 5 minutes to obtain an inorganic alkali-resistant waterproof material.

7. The method for preparing the inorganic alkali-resistant waterproof material according to claim 6, characterized in that: The preparation method of the polymer emulsion is as follows: 6 parts by mass of acrylic acid, 2 parts by mass of acrylamide, 2-4 parts by mass of maleimide-PEG-acrylamide, 0.2-0.4 parts by mass of hydroxyethyl acrylate, 0.02 parts by mass of isooctyl acrylate, 0.8-1.2 parts by mass of 1-dimethylamino-allylphosphonic acid, 4 parts by mass of an emulsifier, and 40 parts by mass of pure water are mixed and stirred until fully emulsified and dissolved, the pH is adjusted to 7, nitrogen is introduced to exclude air, the mixture is heated to 40-50° C., 4-4.5 parts by mass of an initiator, ammonium persulfate, is added, and the mixture is reacted at a constant temperature for 7.5-8.5 hours to obtain a polymer emulsion.

8. The method for preparing the inorganic alkali-resistant waterproof material according to claim 6, characterized in that: The composite colloidal particles are prepared by mixing 10 parts by mass of modified silica microspheres with 90 parts by mass of ethyl acetate, performing ultrasonic dispersion for 30 minutes, then adding 60 parts by mass of porous water-swellable rubber, continuing ultrasonic dispersion for 50 to 70 minutes, then standing for 2 to 4 hours and filtering, placing in a vacuum drying oven at 80° C. and drying for at least 12 hours, then taking out and standing in air for at least 24 hours to obtain the composite colloidal particles.

9. The method for preparing the inorganic alkali-resistant waterproof material according to claim 8, characterized in that: The preparation method of the porous water-swellable rubber is as follows: (1) The preparation steps of acrylamide copolymer are as follows: 6 parts by mass of acrylamide, 0.8-1.2 parts by mass of acrylamide polyethylene glycol thiol, and 1-3 parts by mass of furfuryl methacrylate are added to DMF and stirred to dissolve, then nitrogen is introduced to exclude air, 0.14-0.18 parts by mass of initiator ammonium persulfate is added, and the mixture is heated to 40-50°C and reacted at a constant temperature for 3-4 hours, followed by repeated washing with ethanol 2-4 times and drying to obtain acrylamide copolymer; (2) 100 parts by mass of hydrogenated nitrile rubber were placed on a clean and dry open mill for plasticizing for 1-2 minutes, and then 1-2 parts by mass of stearic acid, 3-5 parts by mass of zinc oxide, 30-50 parts by mass of a mixture of polyethylene glycol and 6 parts by mass of diphenylmethane diisocyanate, 25-35 parts by mass of carbon black N550, 30-50 parts by mass of acrylamide copolymer, and 53-55 parts by mass of allyl polyurethane were added in sequence and mixed evenly. Then, 1.5-2.5 parts by mass of vulcanizing agent diisopropyl peroxide, 0.5-1 parts by mass of co-vulcanizing agent TAIC, and 32-34 parts by mass of pore-forming agent were added and mixed again. After being placed at room temperature for 24 hours, the mixture was put into a twin-screw extruder for extrusion and granulation, and then soaked in deionized water for 2-3 times. Fresh deionized water was replaced before each soaking, and each soaking time was 8-12 hours to obtain a porous water-absorbing and swelling rubber.

10. The method for preparing the inorganic alkali-resistant waterproof material according to claim 6, characterized in that: When the inorganic alkali-resistant waterproof material is used, the inorganic alkali-resistant waterproof material is first coated on the surface of the substrate with a thickness of 1.5-2.0 mm, and then naturally cured for 24 hours and then wet-cured for 7 days at 20-25° C. and humidity ≥90%.

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