Inorganic alkali-resistant waterproof material and preparation method thereof

Abstract

The application 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 is prepared from the following raw material components in mass fractions: 45-48 mass parts of quartz sand, 15-20 mass parts of sulphoaluminate cement, 2-4 mass parts of slaked lime, 20-25 mass parts of polymer emulsion, 6-10 mass parts of mineral powder, 7-12 mass parts of fly ash, 4-8 mass parts of sodium silicate, 3-5 mass parts of silica fume, 4.5-7.8 mass parts of composite colloidal particles, and 0.18-0.35 mass parts of early strength agent. The polymer emulsion is obtained by modifying copolymerized acrylate, acrylamide, hydroxyethyl acrylate and 1-dimethylamino-allyl phosphonic acid by a carboxyl PEG maleimide through an emulsion polymerization method. The composite colloidal particles are obtained by mixing stearic acid, zinc oxide, a mixture of polyethylene glycol and MDI, carbon black N550, acrylamide copolymer, modified polyurethane and pore-forming agent into plasticized hydrogenated butyl nitrile rubber, extruding and granulating the mixture, and then compounding the mixture with modified silica microspheres after pore-forming.

Description

Technical Field

[0001] This invention relates to an inorganic alkali-resistant and waterproof material and its preparation method. Background Technology

[0002] With the rapid development of the construction industry, the requirements for the performance of building materials are becoming increasingly stringent. Waterproofing materials, as an indispensable part of construction projects, directly affect the service life and safety of buildings. However, traditional waterproofing materials have revealed a series of problems in practical applications, mainly including insufficient bonding 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 needs to a certain extent, they are prone to aging and cracking during long-term use, leading to the failure of the waterproofing layer. This is especially true for engineering projects with highly alkaline environments, such as basements and tunnels. Due to the long-term damp and alkaline conditions, the limitations of traditional waterproofing materials are even more pronounced; their insufficient alkali resistance makes them susceptible to erosion and renders them ineffective.

[0004] Furthermore, while some existing waterproofing materials improve their performance by adding various additives, their widespread adoption is often hindered by complex construction processes and high costs. Therefore, developing a waterproofing material with excellent alkali resistance, high bonding strength, and good waterproofing effect is particularly important. Summary of the Invention

[0005] The purpose of this invention is to provide an inorganic alkali-resistant and waterproof material and its preparation method to solve the technical problems mentioned in the background section.

[0006] The technical solution to achieve the objective of this invention is:

[0007] In a first aspect, the present invention provides an inorganic alkali-resistant and waterproof material, wherein the inorganic alkali-resistant and waterproof material, by weight, comprises 45-48 parts by weight of quartz sand, 15-20 parts by weight of sulfoaluminate cement, 2-4 parts by weight of hydrated 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 granules, and 0.18-0.35 parts by weight of early strength agent.

[0008] Furthermore, the polymer emulsion is obtained by copolymerizing acrylic acid, acrylamide, maleimide-PEG-acrylamide, hydroxyethyl acrylate, isooctyl acrylate, and 1-dimethylamino-allylphosphonic acid using an emulsion polymerization method.

[0009] Furthermore, the composite particles are obtained by embedding modified silica microspheres into porous water-absorbing and swelling rubber.

[0010] Furthermore, the modified silica microspheres are made by partially hydrolyzing hydrophobic silica microspheres and grafting mercaptosiloxane oligomers onto their surface.

[0011] Furthermore, the porous water-absorbing and swelling rubber is obtained by mixing, extruding and granulating, and forming pores from a mixture of plasticized hydrogenated nitrile butadiene rubber, stearic acid, zinc oxide, polyethylene glycol and MDI, carbon black N550, acrylamide copolymer, allyl polyurethane, vulcanizing agent, co-vulcanizing agent, and pore-forming agent.

[0012] In a second aspect, the present invention provides a method for preparing an inorganic alkali-resistant and waterproof material as described in the first aspect, comprising the following preparation steps:

[0013] (1) Weigh and prepare the raw materials according to the mass fractions of each component;

[0014] (2) Dry the quartz sand, sulfoaluminate cement, hydrated lime, mineral powder, fly ash, and silica fume;

[0015] (3) After mixing sodium silicate and sulfoaluminate cement evenly, add quartz sand, hydrated lime, mineral powder, fly ash and silica fume and continue to stir and mix for 10-15 minutes to obtain dry mix; among them, pre-mixing sulfoaluminate cement and sodium silicate can avoid clumping;

[0016] (4) Slowly add polymer emulsion and composite granules to the dry mixture and stir for 20-30 minutes to form a uniform slurry;

[0017] (5) Add an early strength agent to the uniform slurry and stir for 5 minutes to obtain an inorganic alkali-resistant and waterproof material.

[0018] Further, 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 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 gas is introduced to remove air, and the mixture is heated to 40-50°C. 4-4.5 parts by mass of ammonium persulfate initiator are added, and the mixture is reacted at a constant temperature for 7.5-8.5 hours to obtain the polymer emulsion.

[0019] Further, the preparation method of the composite granules is as follows: 10 parts by mass of modified silica microspheres are mixed with 90 parts by mass of ethyl acetate, ultrasonically dispersed for 30 min, then 60 parts by mass of porous water-absorbing and swelling rubber are added, ultrasonically dispersed for another 50-70 min, then allowed to stand for 2-4 h, filtered, placed in a vacuum drying oven at 80°C for at least 12 h, and then taken out and allowed to stand in air for at least 24 h to obtain composite granules.

[0020] Furthermore, the preparation method of the porous water-absorbing and swelling rubber is as follows:

[0021] (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 mercapto, and 1~3 parts by mass of methacrylate are added to DMF and stirred to dissolve. Then nitrogen gas is introduced to remove air, 0.14~0.18 parts by mass of initiator ammonium persulfate are added, the mixture is heated to 40~50℃ and reacted at a constant temperature for 3~4 hours. Then the mixture is washed repeatedly with ethanol 2~4 times and dried to obtain acrylamide copolymer;

[0022] (2) Place 100 parts by weight of hydrogenated nitrile rubber on a clean and dry open mill and plasticize for 1-2 minutes. Then, add 1-2 parts by weight of stearic acid, 3-5 parts by weight of zinc oxide, 30-50 parts by weight of a mixture of polyethylene glycol and 6 parts by weight of diphenylmethane diisocyanate, 25-35 parts by weight of carbon black N550, 30-50 parts by weight of acrylamide copolymer, and 53-55 parts by weight of allyl polyurethane and mix evenly. Then, add 1.5-2.5 parts by weight of vulcanizing agent dicumyl peroxide, 0.5-1 parts by weight of co-vulcanizing agent TAIC, and 32-34 parts by weight of pore-forming agent and mix thoroughly again. After standing at room temperature for 24 hours, put it into a twin-screw extruder for extrusion and granulation. Then, soak it in deionized water 2-3 times, replacing the deionized water before each soaking. The soaking time is 8-12 hours each time to obtain porous water-absorbing and expanding rubber.

[0023] Further, the preparation method of the modified silica microspheres is as follows: Acetic acid is added dropwise under stirring to adjust the pH of 300 parts by mass of deionized water to 4-5. Then, an anhydrous ethanol solution containing 2wt% 3-mercaptopropyltriethoxysilane is added at 1 / 3 the volume of the deionized water. After stirring for 8-12 minutes, a mercaptosiloxane oligomer is obtained. Next, 10 parts by mass of hydrophobic silica microspheres are added, and the mixture is ultrasonically dispersed for 30 minutes. The mixture is then continuously stirred at 49-51°C for 3.8-4.2 hours, centrifuged, and the product is... The modified silica microspheres were obtained by centrifuging and washing twice with a 1:1 mixture of ethanol and deionized water, followed by centrifugation and washing once with anhydrous ethanol, and then drying in an oven at 54-56℃ for 23-25 ​​hours. The modified silica microspheres were formed 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 mercaptosiloxane oligomers and dehydrated and condensed, connected by Si-O-Si bonds. Mercapto groups were formed on part of the surface of the silica microspheres, while the remaining surface was covered with hydrophobic groups.

[0024] When using the inorganic alkali-resistant and waterproof material, first apply the inorganic alkali-resistant and waterproof material to the surface of the substrate with a thickness of 1.5~2.0mm, and then allow it to cure naturally for 24 hours before performing wet curing at 20~25℃ and humidity ≥90% for 7 days.

[0025] By adopting the above technical solution, the present invention has the following beneficial effects:

[0026] (1) The inorganic alkali-resistant and waterproof material of the present invention, by mass parts, comprises 45-48 parts by mass of quartz sand, 15-20 parts by mass of sulfoaluminate cement, 2-4 parts by mass of hydrated lime, 20-25 parts by mass of polymer emulsion, 6-10 parts by mass of mineral powder, 7-12 parts by mass of fly ash, 4-8 parts by mass of sodium silicate, 3-5 parts by mass of silica fume, 4.5-7.8 parts by mass of composite granules, and 0.18-0.35 parts by mass of early strength agent. The inorganic alkali-resistant and waterproof material prepared has high bonding strength, good alkali resistance, and excellent alkali prevention effect.

[0027] (2) The polymer emulsion of the present invention works synergistically with sulfoaluminate cement, resulting in better bonding strength.

[0028] (3) Sodium silicate of the present invention can form dense calcium silicate gel as an alkali activator, which has good alkali resistance.

[0029] (4) The inorganic alkali-resistant and waterproof material of the present invention can be directly applied and is suitable for damp substrates.

[0030] (5) No organic solvents are added to the raw material components of the inorganic alkali-resistant and waterproof material of the present invention, and the VOC content meets the GB18582-2020 standard.

[0031] (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. By introducing long-chain maleimide-PEG-acrylamide, the molecular side chain length of the polymer is increased. The long side chain polymer chain can penetrate into the interface of the substrate to be adhered, and then form chain entanglement with the surface molecular layer of the substrate to form interfacial adhesion, thereby increasing the bonding strength of the inorganic alkali-resistant and waterproof material. At the same time, by introducing active groups such as hydroxyl and phosphate groups, the bonding strength between the polymer chain and the substrate can be further enhanced.

[0032] (7) The composite granules of the present invention can effectively enhance the elasticity of materials and reduce shrinkage cracks.

[0033] (8) The composite granules of the present invention are obtained by embedding modified silica microspheres into porous water-absorbing and swelling rubber; wherein, the porous water-absorbing and swelling rubber is obtained by mixing, extruding and granulating, and forming pores of a mixture of plasticized hydrogenated nitrile butadiene rubber, stearic acid, zinc oxide, polyethylene glycol and MDI, carbon black N550, acrylamide copolymer, allyl polyurethane, vulcanizing agent, co-vulcanizing agent, and pore-forming agent; the acrylamide copolymer is obtained by copolymerizing acrylamide, acrylamide polyethylene glycol mercapto, and furfuryl methacrylate; and MDI is used as a chain extender. The agent grafts acrylamide copolymer and polyethylene glycol together, forming an interpenetrating crosslinked network composed of repeating segments—acrylamide copolymer, MDI, polyethylene glycol, and the molecular chains of the rubber matrix. Allyl polyurethane is grafted through double bonds on the rubber molecular backbone via isocyanate-acrylamide copolymer reaction, preventing polyethylene glycol, acrylamide copolymer, and allyl polyurethane from precipitating from the rubber matrix and affecting the swelling stability of the water-absorbing and swelling rubber. The polyethylene glycol in the crosslinked network of the water-absorbing and swelling rubber... Acrylamide copolymers and allyl polyurethane continuously absorb water molecules, causing the volume of the water-absorbing and swelling rubber to expand. This volume expansion causes the network molecular chains of the rubber matrix to extend outward, deforming its cross-linked structure. The rubber matrix, with its excellent elastic properties, simultaneously generates a binding force that inhibits 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 copolymers, and allyl polyurethane can absorb a large amount of water, causing the volume expansion ratio of the water-absorbing and swelling rubber to continuously increase. Modified silica microspheres are embedded in the porous water-absorbing and swelling rubber through channels. Then, through the reaction of surface thiol groups with thiol groups in the porous water-absorbing and swelling rubber, they cross-link. When the composite particles are mixed with inorganic alkali-resistant and waterproof materials, the composite particles absorb water and expand, squeezing the channels on the surface of the composite particles. The channels are squeezed and tightened, extruding the hydrophobic part of the modified silica microspheres from the porous water-absorbing and swelling rubber, forming a micron-sized hydrophobic papillary structure on the surface of the composite particles, thereby enhancing the waterproof performance of the inorganic alkali-resistant and waterproof materials.

[0034] (8) In this invention, after the components of the inorganic alkali-resistant and waterproof material are mixed, the composite particles absorb water and swell, so that the composite particles are in full contact with the polymer molecular chains. The furan groups on the composite particles undergo a DA reaction with the maleimide of the polymer molecular chains to crosslink, thereby making the composite particles stable and uniformly dispersed in the inorganic alkali-resistant and waterproof material. This avoids the agglomeration of adhesive powder from affecting the mechanical properties of the inorganic alkali-resistant and waterproof material, while increasing the toughness of the inorganic alkali-resistant and waterproof material.

[0035] (9) In this invention, after mixing the components of the inorganic alkali-resistant waterproof material, the quicklime reacts with the phosphoric acid in the polymer molecular chain to form calcium phosphate insolubles, which can effectively improve the density and hardness of the inorganic alkali-resistant waterproof material and effectively increase the waterproof and seepage-proof performance of the inorganic alkali-resistant waterproof material. Detailed Implementation

[0036] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0037] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0038] The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0039] The following are some of the raw materials used in the embodiments and comparative examples of the present invention:

[0040] Hydrophobic silica microspheres: 2 parts by mass of silica microspheres with a D50 of 20 μm were heated to 120 °C, then mixed with ethanol and ultrasonically dispersed for 30 min to obtain 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 dropwise at 3 s / drop, followed by reflux at 130 °C for 50 min, then centrifuged and washed 4 times with ethanol, and dried to constant weight to obtain hydrophobic silica microspheres.

[0041] Pore-forming agent: 450 mesh potassium chloride.

[0042] Acrylamide polyethylene glycol mercapto: SH-PEG-ACA, molecular weight 2000.

[0043] Maleimide-PEG-AcA: Mal-PEG-AcA, molecular weight 2000

[0044] The polyethylene glycol used is polyethylene glycol-4000.

[0045] 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 3s until the pH value reaches 1. After the addition is complete, acrolein is slowly added dropwise from room temperature to 85℃. After the addition is complete, the reaction is continued for 2 hours to terminate the reaction. The molar ratio of dimethylamine to phosphorous acid and acrolein is 1:1:1. The reaction mechanism is as follows:

[0046] .

[0047] The preparation steps of allyl polyurethane are as follows: the polyether-type PU prepolymer is stirred at 50°C for 30 min; after stirring evenly, hydroxyethyl acrylate is added dropwise to the flask at 2 s / min, the molar ratio of hydroxyethyl acrylate to isocyanate of the polyether-type PU prepolymer is 1:2, and the reaction is carried out at a constant temperature for 4 h to obtain allyl polyurethane. Example 1

[0048] A method for preparing an inorganic alkali-resistant and waterproof material includes the following preparation steps:

[0049] (1) Weigh and prepare the raw materials according to the following mass parts: 45 parts by mass of quartz sand, 15 parts by mass of sulfoaluminate cement, 2 parts by mass of hydrated 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.

[0050] (2) Dry the weighed quartz sand, sulfoaluminate cement, hydrated lime, mineral powder, fly ash and silica fume;

[0051] (3) After the weighed sodium silicate and sulfoaluminate cement are mixed evenly, quartz sand, hydrated lime, mineral powder, fly ash and silica fume are added and stirred at 1000 rpm for 10 min to obtain dry mix.

[0052] (4) Slowly add polymer emulsion and composite granules to the dry mixture and stir at 1500 rpm for 20 min to form a uniform slurry;

[0053] (5) Add an early strength agent to the uniform slurry and stir at 80 rpm for 5 min to obtain an inorganic alkali-resistant and waterproof material.

[0054] The polymer emulsion is prepared 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 gas is introduced to remove air, and 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 the polymer emulsion.

[0055] The method for preparing the composite granules is as follows: 10 parts by mass of modified silica microspheres are mixed with 90 parts by mass of ethyl acetate and ultrasonically dispersed for 30 min. Then, 60 parts by mass of porous water-absorbing and swelling rubber are added and ultrasonically dispersed for another 50 min. After standing for 2 h, the mixture is filtered and placed in a vacuum drying oven at 80°C for at least 12 h. After drying, the mixture is taken out and left to stand in the air for at least 24 h to obtain the composite granules.

[0056] The method for preparing the porous water-absorbing and swelling rubber is as follows:

[0057] (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 mercapto and 1 part by mass of methacrylate are added to DMF and stirred to dissolve. Then nitrogen gas is introduced to remove air, 0.14 parts by mass of initiator ammonium persulfate is added, heated to 40°C, and reacted at a constant temperature for 3 hours. Then the mixture is washed twice with ethanol and dried to obtain acrylamide copolymer.

[0058] (2) After placing 100 parts by weight of hydrogenated nitrile rubber on a clean and dry open mill for 1 min of plasticizing, 1 part by weight of stearic acid, 3 parts by weight of zinc oxide, 30 parts by weight of a mixture of polyethylene glycol and 6 parts by weight of diphenylmethane diisocyanate, 25 parts by weight of carbon black N550, 30 parts by weight of acrylamide copolymer, and 53 parts by weight of allyl polyurethane are added and mixed evenly. Then, 1.5 parts by weight of vulcanizing agent dicumyl peroxide, 0.5 parts by weight of co-vulcanizing agent TAIC, and 32 parts by weight of pore-forming agent are added and mixed thoroughly again. After being placed at room temperature for 24 h, the mixture is extruded and granulated in a twin-screw extruder. Then, it is soaked in deionized water twice, with fresh deionized water replaced before each soaking. Each soaking time is 8 h to obtain porous water-absorbing and expanding rubber. The temperature of the twin-screw extruder is 140~170℃, the feeding frequency is 22Hz, and the main machine speed is 90r / min.

[0059] The modified silica microspheres are prepared as follows: Acetic acid is added dropwise under stirring to adjust the pH of 300 parts by mass of deionized water to 4. Then, an anhydrous ethanol solution containing 2wt% 3-mercaptopropyltriethoxysilane is added at 1 / 3 volume of deionized water. After stirring for 8 minutes, mercaptosiloxane oligomers are obtained. Next, 10 parts by mass of hydrophobic silica microspheres are added, and the mixture is ultrasonically dispersed for 30 minutes. The mixture is then continuously stirred at 49°C for 3.8 hours, centrifuged, and washed twice with a 1:1 mixture of ethanol and deionized water. It is then washed once with anhydrous ethanol and dried in an oven at 54°C for 23 hours to obtain the modified silica microspheres.

[0060] When using the inorganic alkali-resistant and waterproof material, first apply the inorganic alkali-resistant and waterproof material to the surface of the substrate with a thickness of 2mm, and then allow it to cure naturally for 24 hours before performing wet curing at 25℃ and humidity ≥90% for 7 days. Example 2

[0061] A method for preparing an inorganic alkali-resistant and waterproof material includes the following preparation steps:

[0062] (1) Weigh and prepare the raw materials according to the following mass parts: 48 parts quartz sand, 18 parts sulfoaluminate cement, 3 parts hydrated lime, 22 parts polymer emulsion, 8 parts mineral powder, 10 parts fly ash, 6 parts sodium silicate, 4 parts silica fume, 6 parts composite granules, and 0.27 parts early strength agent.

[0063] (2) Dry the weighed quartz sand, sulfoaluminate cement, hydrated lime, mineral powder, fly ash and silica fume;

[0064] (3) After the weighed sodium silicate and sulfoaluminate cement are mixed evenly, quartz sand, hydrated lime, mineral powder, fly ash and silica fume are added and stirred at 1000 rpm for 13 min to obtain dry mix.

[0065] (4) Slowly add polymer emulsion and composite granules to the dry mixture and stir at 1500 rpm for 25 min to form a uniform slurry;

[0066] (5) Add an early strength agent to the uniform slurry and stir at 80 rpm for 5 min to obtain an inorganic alkali-resistant and waterproof material.

[0067] The polymer emulsion is prepared 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 gas is introduced to remove air, and the mixture is heated to 45°C. 4.3 parts by mass of initiator ammonium persulfate are added and reacted at a constant temperature for 8 hours to obtain the polymer emulsion.

[0068] The method for preparing the composite granules is as follows: 10 parts by mass of modified silica microspheres are mixed with 90 parts by mass of ethyl acetate and ultrasonically dispersed for 30 min. Then, 60 parts by mass of porous water-absorbing and swelling rubber are added and ultrasonically dispersed for another 60 min. After standing for 3 h, the mixture is filtered and placed in a vacuum drying oven at 80°C for at least 12 h. After that, it is taken out and left to stand in the air for at least 24 h to obtain the composite granules.

[0069] The method for preparing the porous water-absorbing and swelling rubber is as follows:

[0070] (1) The preparation steps of acrylamide copolymer are as follows: 6 parts by mass of acrylamide, 1 part by mass of acrylamide polyethylene glycol mercapto and 2 parts by mass of methacrylate are added to DMF and stirred to dissolve. Then nitrogen gas is introduced to remove air, 0.16 parts by mass of initiator ammonium persulfate is added, heated to 45°C, and reacted at a constant temperature for 3.5 h. Then the copolymer is washed repeatedly with ethanol 3 times and dried to obtain acrylamide copolymer.

[0071] (2) After placing 100 parts by weight of hydrogenated nitrile rubber on a clean and dry open mill for plasticizing for 1.5 min, 1.5 parts by weight of stearic acid, 4 parts by weight of zinc oxide, 40 parts by weight of a mixture of polyethylene glycol and 6 parts by weight of diphenylmethane diisocyanate, 30 parts by weight of carbon black N550, 40 parts by weight of acrylamide copolymer, and 54 parts by weight of allyl polyurethane were added and mixed evenly. Then, 2 parts by weight of vulcanizing agent dicumyl peroxide, 0.8 parts by weight of co-vulcanizing agent TAIC, and 33 parts by weight of pore-forming agent were added and mixed thoroughly again. After being placed at room temperature for 24 h, the mixture was extruded and granulated in a twin-screw extruder. Then, it was soaked in deionized water 3 times, with fresh deionized water replaced before each soaking. Each soaking time was 12 h to obtain porous water-absorbing and expanding rubber. The temperature of the twin-screw extruder was 140~170℃, the feeding frequency was 22Hz, and the main machine speed was 90r / min.

[0072] The modified silica microspheres are prepared as follows: Acetic acid is added dropwise under stirring to adjust the pH of 300 parts by mass of deionized water to 5. Then, an anhydrous ethanol solution containing 2wt% 3-mercaptopropyltriethoxysilane is added at 1 / 3 the volume of deionized water. After stirring for 10 minutes, mercaptosiloxane oligomers are obtained. Next, 10 parts by mass of hydrophobic silica microspheres are added, and the mixture is ultrasonically dispersed for 30 minutes. After stirring continuously at 50°C for 4 hours, the mixture is centrifuged and washed twice with a 1:1 mixture of ethanol and deionized water. Then, it is washed once with anhydrous ethanol and dried in an oven at 55°C for 24 hours to obtain modified silica microspheres.

[0073] When using the inorganic alkali-resistant and waterproof material, first apply the inorganic alkali-resistant and waterproof material to the surface of the substrate with a thickness of 2mm, and then allow it to cure naturally for 24 hours before performing wet curing at 25℃ and humidity ≥90% for 7 days. Example 3

[0074] A method for preparing an inorganic alkali-resistant and waterproof material includes the following preparation steps:

[0075] (1) Weigh and prepare the raw materials according to the following mass parts: 47 parts by mass of quartz sand, 20 parts by mass of sulfoaluminate cement, 4 parts by mass of hydrated 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.

[0076] (2) Dry the weighed quartz sand, sulfoaluminate cement, hydrated lime, mineral powder, fly ash and silica fume;

[0077] (3) After weighing the sodium silicate and sulfoaluminate cement and mixing them evenly, add quartz sand, hydrated lime, mineral powder, fly ash and silica fume and stir at 1000 rpm for 15 min to obtain dry mix.

[0078] (4) Slowly add polymer emulsion and composite granules to the dry mixture and stir at 1500 rpm for 30 min to form a uniform slurry;

[0079] (5) Add an early strength agent to the uniform slurry and stir at 80 rpm for 5 min to obtain an inorganic alkali-resistant and waterproof material.

[0080] The polymer emulsion is prepared 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 gas is introduced to remove air, and the mixture is heated to 50°C. 4.5 parts by mass of initiator ammonium persulfate are added and reacted at a constant temperature for 8.5 hours to obtain the polymer emulsion.

[0081] The method for preparing the composite granules is as follows: 10 parts by mass of modified silica microspheres are mixed with 90 parts by mass of ethyl acetate and ultrasonically dispersed for 30 min. Then, 60 parts by mass of porous water-absorbing and swelling rubber are added and ultrasonically dispersed for another 70 min. After standing for 4 h, the mixture is filtered and placed in a vacuum drying oven at 80°C for at least 12 h. After drying, the mixture is taken out and left to stand in the air for at least 24 h to obtain the composite granules.

[0082] The method for preparing the porous water-absorbing and swelling rubber is as follows:

[0083] (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 mercapto and 3 parts by mass of methacrylate are added to DMF and stirred to dissolve. Then nitrogen gas is introduced to remove air, 0.18 parts by mass of initiator ammonium persulfate is added, heated to 50°C, and reacted at a constant temperature for 4 hours. Then the mixture is washed repeatedly with ethanol 4 times and dried to obtain acrylamide copolymer.

[0084] (2) After 100 parts by weight of hydrogenated nitrile rubber were plasticized on a clean and dry open mill for 2 minutes, 2 parts by weight of stearic acid, 5 parts by weight of zinc oxide, 50 parts by weight of a mixture of polyethylene glycol and 6 parts by weight of diphenylmethane diisocyanate, 35 parts by weight of carbon black N550, 50 parts by weight of acrylamide copolymer, and 55 parts by weight of allyl polyurethane were added and mixed evenly. Then, 2.5 parts by weight of vulcanizing agent dicumyl peroxide, 1 part by weight of co-vulcanizing agent TAIC, and 34 parts by weight of pore-forming agent were added and mixed thoroughly again. After being placed at room temperature for 24 hours, the mixture was extruded and granulated in a twin-screw extruder. Then, it was soaked in deionized water 3 times, with fresh deionized water replaced before each soaking. Each soaking time was 12 hours to obtain porous water-absorbing and expanding rubber. The temperature of the twin-screw extruder was 140~170℃, the feeding frequency was 22Hz, and the main machine speed was 90r / min.

[0085] The modified silica microspheres are prepared as follows: Acetic acid is added dropwise under stirring to adjust the pH of 300 parts by mass of deionized water to 5. Then, an anhydrous ethanol solution containing 2wt% 3-mercaptopropyltriethoxysilane is added at 1 / 3 the volume of deionized water. After stirring for 12 minutes, mercaptosiloxane oligomers are obtained. Next, 10 parts by mass of hydrophobic silica microspheres are added, and the mixture is ultrasonically dispersed for 30 minutes. After stirring continuously at 51°C for 4.2 hours, the mixture is centrifuged and washed twice with a 1:1 mixture of ethanol and deionized water. Then, it is washed once with anhydrous ethanol and dried in an oven at 56°C for 25 hours to obtain modified silica microspheres.

[0086] When using the inorganic alkali-resistant and waterproof material, first apply the inorganic alkali-resistant and waterproof material to the surface of the substrate with a thickness of 2mm, and then allow it to cure naturally for 24 hours before performing wet curing at 25℃ and humidity ≥90% for 7 days. Comparative Example 1

[0087] The difference between Comparative Example 1 and Example 2 is that the inorganic alkali-resistant and waterproof material raw material components, by weight, 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 granules, and 0.27 parts by weight of early strength agent. The remaining components and steps are the same as in Example 2. Comparative Example 2

[0088] The difference between Comparative Example 2 and Example 2 is that the inorganic alkali-resistant and waterproof material raw material components, by weight, only include 48 parts by weight of quartz sand, 18 parts by weight of sulfoaluminate cement, 3 parts by weight of hydrated 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 adhesive powder, and 0.27 parts by weight of early strength agent. The remaining components and steps are the same as in Example 2. Comparative Example 3

[0089] 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, while the other components and steps are the same as in Example 2. Comparative Example 4

[0090] The difference between Comparative Example 4 and Example 2 is that the polymer emulsion is obtained by copolymerizing only acrylic acid, acrylamide, hydroxyethyl acrylate, isooctyl acrylate, and maleimide-PEG-acrylamide, while the other components and steps are the same as in Example 2. Comparative Example 5

[0091] The difference between Comparative Example 5 and Example 2 is that the composite granules are obtained by mixing plasticized hydrogenated nitrile butadiene 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, and then mixing with modified silica microspheres. The remaining components and steps are the same as in Example 2. Comparative Example 6

[0092] The difference between Comparative Example 6 and Example 2 is that the composite granules are porous water-absorbing and swelling rubber, while the other components and steps are the same as in Example 2.

[0093] Example of effect

[0094] Alkali resistance: The inorganic alkali-resistant and waterproof materials prepared in the examples and comparative examples were coated on the substrate surface according to standard JC / T984-2011 with a thickness of 2 mm. After natural curing for 24 hours, they were wet-cured for 7 days at 25°C and humidity ≥90%. After curing, they were soaked in 10% sodium hydroxide solution for 30 days, and the mass loss rate was calculated.

[0095] Table 1 below shows the performance data of the inorganic alkali-resistant and waterproof materials prepared in the examples and comparative examples, tested according to standard JC / T984-2011:

[0096] Table 1

[0097]

[0098] As shown in 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 impermeable properties, and good alkali resistance.

[0099] The difference between Comparative Example 1 and Example 2 is that the inorganic alkali-resistant waterproof material does not contain slaked lime, so calcium phosphate cannot be formed in the inorganic alkali-resistant waterproof material, resulting in poor impermeability, flexural strength, and alkali resistance.

[0100] The difference between Comparative Example 2 and Example 2 is that the inorganic alkali-resistant and waterproof material does not contain composite adhesive powder but uses conventional adhesive powder. The bonding strength, waterproof and impermeable properties, and flexural strength of the inorganic alkali-resistant and waterproof material are not good. The water-absorbing and swelling rubber also has a certain promoting effect on increasing the bonding strength of the inorganic alkali-resistant and waterproof material.

[0101] The difference between Comparative Example 3 and Example 2 is that the polymer emulsion did not use maleimide-PEG-acrylamide copolymerization, resulting in inorganic alkali-resistant and waterproof materials with poor bonding strength and flexural strength.

[0102] The difference between Comparative Example 4 and Example 2 is that the polymer emulsion was not copolymerized with 1-dimethylamino-allylphosphonic acid. The resulting inorganic alkali-resistant and waterproof material had poorer bonding strength, flexural strength, impermeability, and alkali resistance than the inorganic alkali-resistant and waterproof material obtained in the Example.

[0103] The difference between Comparative Example 5 and Example 2 is that the composite granules are made of water-absorbing and swelling rubber instead of porous water-absorbing and swelling rubber combined with modified silica. The resulting inorganic alkali-resistant and waterproof material has poorer bonding strength and impermeability than the inorganic alkali-resistant and waterproof material prepared in the Example.

[0104] The difference between Comparative Example 6 and Example 2 is that the composite granules are made of porous water-absorbing and expanding rubber. The inorganic alkali-resistant and waterproof material prepared without the addition of modified silica has poorer impermeability than the inorganic alkali-resistant and waterproof material prepared in the Example.

[0105] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely 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 within the protection scope of the present invention.

Claims

1. An inorganic alkali-resistant waterproofing material, characterized by comprising: The inorganic alkali-resistant waterproof material comprises, in parts by mass, 45-48 parts of quartz sand, 15-20 parts of sulphoaluminate 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 colloidal particles, and 0.18-0.35 parts of early strength agent. The polymer emulsion is obtained by copolymerization of acrylic acid, acrylamide, maleimide-PEG-acrylamide, hydroxyethyl acrylate, isooctyl acrylate and 1-dimethylamino-allyl phosphonic acid by emulsion polymerization. The composite colloidal particles are obtained by embedding modified silica microspheres in porous water-absorbing and swelling rubber.

2. The inorganic alkali-resistant waterproofing material according to claim 1, characterized by, The modified silica microspheres are obtained by partially hydrolyzing hydrophobic silica microspheres and grafting mercaptosiloxane oligomers on the surface of the silica microspheres.

3. The inorganic alkali-resistant waterproofing material according to claim 1, characterized in that, The porous water-absorbing and swelling rubber is obtained by mixing, kneading, extruding, granulating and porating a mixture of plasticized hydrogenated nitrile rubber, stearic acid, zinc oxide, polyethylene glycol and MDI, carbon black N550, acrylamide copolymer, allyl polyurethane, vulcanizing agent, vulcanizing aid and pore-forming agent.

4. A method for producing the inorganic alkali-resistant waterproofing material according to any one of claims 1 to 3, characterized by, The method comprises the following steps: (1) weighing the raw materials according to the corresponding mass fractions; (2) drying the quartz sand, sulphoaluminate cement, slaked lime, mineral powder, fly ash and silica fume; (3) mixing the sodium silicate and sulphoaluminate cement uniformly, then adding the quartz sand, slaked lime, mineral powder, fly ash and silica fume and continuing to stir and mix for 10-15 minutes to obtain dry mixture; (4) slowly adding the polymer emulsion and composite colloidal particles to the dry mixture and stirring for 20-30 minutes to form a uniform slurry; (5) adding the early strength agent to the uniform slurry and stirring for 5 minutes to obtain the inorganic alkali-resistant waterproof material.

5. The method for producing an inorganic alkali-resistant waterproof material according to claim 4, characterized by, The polymer emulsion is prepared by mixing 6 parts of acrylic acid, 2 parts of acrylamide, 2-4 parts of maleimide-PEG-acrylamide, 0.2-0.4 parts of hydroxyethyl acrylate, 0.02 parts of isooctyl acrylate, 0.8-1.2 parts of 1-dimethylamino-allyl phosphonic acid, 4 parts of emulsifier and 40 parts of pure water, stirring until emulsification and dissolution, adjusting the pH to 7, purging air by nitrogen, heating to 40-50℃, adding 4-4.5 parts of initiator ammonium persulfate and constant-temperature reacting for 7.5-8.5 hours to obtain the polymer emulsion.

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

7. The method for producing an inorganic alkali-resistant waterproof material according to claim 6, characterized by, The porous water-absorbing and swelling rubber is prepared by the following method: (1) The preparation steps of the 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 into DMF and stirred and dissolved, then nitrogen is introduced to remove air, 0.14-0.18 parts by mass of initiator ammonium persulfate is added, heated to 40-50 DEG C, constant temperature reaction for 3-4 h, then washed repeatedly with ethanol for 2-4 times, and dried to obtain the acrylamide copolymer; (2) 100 parts by mass of hydrogenated butyl rubber is placed on a clean and dry open mill for plasticizing for 1-2 min, 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 diphenyl methane diisocyanate, 25-35 parts by mass of carbon black N550, 30-50 parts by mass of acrylamide copolymer, 53-55 parts by mass of allyl polyurethane are added and uniformly mixed, then 1.5-2.5 parts by mass of vulcanizing agent dicumyl peroxide, 0.5-1 part by mass of auxiliary vulcanizing agent TAIC, and 32-34 parts by mass of pore-forming agent are added and fully mixed, placed at room temperature for 24 h, then put into a double-screw extruder for extruding and granulating, then soaked in deionized water for 2-3 times, the deionized water is replaced every time, and the soaking time is 8-12 h each time, to obtain the porous water-absorbing and swelling rubber.

8. The method for preparing the inorganic alkali-resistant waterproof material according to claim 4, 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 base material with a thickness of 1.5-2.0 mm, and then naturally cured for 24 h, and then wet-cured at 20-25 DEG C and humidity ≥90% for 7 days.

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