Preparation process of building concrete primary color and color difference repairing agent

Abstract

The invention relates to the technical field of building material repairing, in particular to a building concrete primary color and color difference repairing agent preparation technology which comprises the following steps: S1, preparing synthetic resin emulsion; s2, preparing a dispersing agent; s3, preparing a waterproof agent and performing modification; s4, preparing a natural mineral pigment; s5, adding a waterproof agent, a dispersing agent, an anti-ultraviolet agent and a natural mineral pigment into the synthetic resin emulsion, and performing temperature-controlled stirring to obtain a repairing agent emulsion; s6, the PH of the repairing agent emulsion is adjusted to be 7.5-8.0; and S7, filtering the repairing agent emulsion by adopting a 0.22 mu m ceramic membrane to remove undispersed particles so as to obtain a repairing agent finished product, and sub-packaging and storing the repairing agent finished product. The repairing agent prepared by the process has the performance of environmental protection, no toxicity, efficient repairing and long-acting protection.

Description

Technical Field

[0001] The present invention relates to the technical field of building material repair, in particular to a preparation process of a building concrete base color difference repairing agent. Background Art

[0002] As time goes by, the surface of concrete buildings often develops rust, stains, and weathering. In order to ensure the beauty of the building surface and extend the service life of concrete, repair agents are often applied to the surface of concrete buildings.

[0003] However, currently used concrete color-difference repair techniques often rely on a single coating or solid-color masking method, which can lead to recurrence of color differences after repair, poor coating durability, and insufficient environmental performance. Traditional repair agents struggle to achieve a "repair as good as new" visual effect and exhibit poor substrate penetration, adhesion, and weather resistance.

[0004] Therefore, developing a concrete color difference repair agent that is highly efficient, environmentally friendly, non-toxic, and provides long-lasting protection has become a technical problem that needs to be urgently solved in the industry. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation process of a color difference repair agent for building concrete base color, so as to solve the problem that the currently commonly used concrete color difference repair agents are difficult to have both environmental protection and non-toxicity, high efficiency repair and long-term protection performance.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a building concrete base color difference repair agent, which is prepared from the following raw materials in mass percentage: 55-65% synthetic resin emulsion, 22-25% dispersant, 5-8% waterproofing agent, 2-4% anti-ultraviolet agent, and 3-5% natural mineral pigment.

[0007] A preparation process of a building concrete base color difference repair agent comprises the following steps: S1, preparing synthetic resin emulsion; First, select the following raw materials according to mass percentage: Bio-based acrylate monomer 30-40%, water-based epoxy resin 18-25%, nano-silica 5-8%, non-ionic emulsifier 8-12%, UV initiator 1-2%, deionized water 10-15%, ammonium persulfate 1-2%, dodecyl mercaptan 1-3%; Secondly, bio-based acrylate monomer, ammonium persulfate and dodecyl mercaptan were added to the reactor to initiate free radical polymerization; Next, a nonionic emulsifier is added into the reactor to form a preliminary emulsion, and the particle size is controlled to be ≤100 nm; Next, water-based epoxy resin and nano-silica are added to the preliminary emulsion, stirred at high speed to achieve uniform dispersion, and then ultraviolet initiator is introduced and cured under ultraviolet light to promote cross-linking reaction and improve coating density.

[0008] Finally, the solidified emulsion is filtered through an ultrafiltration membrane to remove unreacted monomers, deionized water is added, and the emulsion is bottled under nitrogen protection. The shelf life is ≥12 months.

[0009] S2, preparing a dispersant; First, sugarcane bagasse, concentrated sulfuric acid, ammonia water and purified water are selected as raw materials; Secondly, sugarcane bagasse is hydrothermally carbonized with concentrated sulfuric acid to generate carbon quantum dot precursors; Next, the pH of the carbon quantum dot precursor was adjusted to 8-9 with ammonia water, and the precursor was dispersed in pure water after centrifugal purification. S3, preparing a waterproofing agent and modifying it; First, castor oil, γ-aminopropyltriethoxysilane, and tetrabutyl titanate catalyst were selected as raw materials; Secondly, transesterification reaction is carried out; Castor oil and γ-aminopropyltriethoxysilane are mixed in a molar ratio of 1:2, and tetrabutyl titanate catalyst is added to react; Next, the product after the transesterification reaction is subjected to polycondensation to generate a polysiloxane hydrophobic resin; S4, preparing natural mineral pigments; First, the raw materials are pretreated; Hematite is selected as the natural mineral raw material and crushed to a particle size of less than 100 μm using wet ball milling to reduce dust pollution generated by traditional dry milling. Elutriation is then used to separate particles of different sizes, retaining particles of 20-50 μm as the selected raw material to improve reaction efficiency. The medium used in wet ball milling is water or ethanol.

[0010] Secondly, the selected raw materials are calcined at high temperature to promote the transformation of Fe2O3 crystal form and enhance the light resistance and tinting power of the pigment.

[0011] Next, the selected raw materials after high-temperature calcination are purified by acid leaching and then separated by ultrafiltration membrane to obtain Fe³⁺ solution; From this, Fe³⁺ solution and urea are hydrothermally synthesized at 80-100°C to generate nano-sized α-Fe2O3 particles to improve the dispersibility and hiding power of the pigment.

[0012] Finally, the nano-sized α-Fe2O3 particles were encapsulated in chitosan using a complex coacervation method to ensure that the shelf life of the pigment was extended to more than 2 years.

[0013] S5. Add a waterproofing agent, a dispersant, an anti-ultraviolet agent, and a natural mineral pigment to the synthetic resin emulsion and stir under controlled temperature to obtain a repair agent emulsion; Among them, tannic acid is used as the anti-ultraviolet agent; S6. Adjust the pH of the repair agent emulsion to 7.5-8.0 to ensure the stability of the repair agent emulsion; use 0.1M citric acid / sodium bicarbonate to adjust the pH.

[0014] S7. Use a 0.22 μm ceramic membrane to filter the repair agent emulsion to remove undispersed particles to obtain the finished repair agent, and then package and store the finished repair agent.

[0015] Preferably, in step S1, the temperature in the reactor is controlled at 70-80° C. when initiating free radical polymerization, and 365 nm ultraviolet light is used for curing the emulsion for 5 minutes.

[0016] Preferably, in step S2, when the sugarcane bagasse and concentrated sulfuric acid are subjected to hydrothermal carbonization reaction, the mass ratio of sugarcane bagasse to concentrated sulfuric acid is 1:3, the reaction temperature is 600° C., and the reaction time is 6 hours.

[0017] Preferably, in step S2, the pH of the carbon quantum dot precursor is adjusted to 8-9 with aqueous ammonia, and the concentration is adjusted to 2 mg / mL when dispersed in pure water after centrifugal purification.

[0018] Preferably, the temperature of the transesterification reaction in step S3 is 80°C and the reaction time is 4 hours. Preferably, the temperature of the polycondensation of the product after the transesterification reaction in step S3 is 120°C.

[0019] Preferably, when the selected raw materials are calcined at high temperature in step S4, the calcination temperature is 600-800° C. and the calcination time is 2-4 hours.

[0020] Preferably, when the Fe³⁺ solution is subjected to ultrafiltration membrane separation in step S4, a ceramic membrane with a pore size of 0.1 μm is used to intercept undissolved mineral residues, and the solution is concentrated by nanofiltration membrane to a Fe³⁺ concentration of ≥10%.

[0021] Preferably, when the mixture is stirred under controlled temperature in step S5, the temperature is 25° C., a magnetic stirrer is used, and the stirring time is 2 h.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The present invention relates to a preparation process of a building concrete base color difference repair agent. During the preparation of the repair agent, a large amount of biomass raw materials are used to reduce carbon emissions; the adhesion and oxidation resistance of the repair agent are enhanced; and a bio-based waterproofing agent is used to better achieve the effects of water release and anti-fouling; thereby better solving the problems of traditional repair agents such as high toxicity, easy shedding, and color difference recurrence, and the method can be widely used in the fields of building repair, infrastructure maintenance, etc. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0024] Example: A color difference repair agent for building concrete base color is prepared from the following raw materials in percentage by mass: 55-65% synthetic resin emulsion, 22-25% dispersant, 5-8% waterproofing agent, 2-4% anti-ultraviolet agent, and 3-5% natural mineral pigment.

[0025] A preparation process of a building concrete base color difference repair agent comprises the following steps: S1, preparing synthetic resin emulsion; First, the following raw materials are selected according to mass percentage: bio-based acrylate monomer 30-40%, water-based epoxy resin 18-25%, nano-silica 5-8%, non-ionic emulsifier 8-12%, ultraviolet initiator 1-2%, deionized water 10-15%, ammonium persulfate 1-2%, and dodecyl mercaptan 1-3%; Secondly, bio-based acrylate monomer, ammonium persulfate and dodecyl mercaptan were added to the reactor to initiate free radical polymerization; The temperature in the reactor is controlled at 70-80° C. when initiating free radical polymerization, and 365 nm ultraviolet light is used for ultraviolet curing of the emulsion, and the curing time is 5 minutes.

[0026] Next, a nonionic emulsifier is added into the reactor to form a preliminary emulsion; Next, water-based epoxy resin and nano-silica are added to the preliminary emulsion, stirred at high speed to achieve uniform dispersion, and then a UV initiator is introduced and cured under UV light; Finally, the solidified emulsion is filtered through an ultrafiltration membrane to remove unreacted monomers, deionized water is added, and the emulsion is bottled under nitrogen protection. S2, preparing a dispersant; First, sugarcane bagasse, concentrated sulfuric acid, ammonia water and purified water are selected as raw materials; Secondly, sugarcane bagasse is hydrothermally carbonized with concentrated sulfuric acid to generate carbon quantum dot precursors; Among them, when the sugarcane bagasse and concentrated sulfuric acid are subjected to hydrothermal carbonization reaction, the mass ratio of sugarcane bagasse to concentrated sulfuric acid is 1:3, the reaction temperature is 600°C, and the reaction time is 6h.

[0027] Next, the pH of the carbon quantum dot precursor was adjusted to 8-9 with ammonia water, and after centrifugal purification, it was dispersed in pure water and the concentration was adjusted to 2 mg / mL.

[0028] S3, preparing a waterproofing agent and modifying it; First, castor oil, γ-aminopropyltriethoxysilane, and tetrabutyl titanate catalyst were selected as raw materials; Secondly, transesterification reaction is carried out; Castor oil and γ-aminopropyltriethoxysilane were mixed in a molar ratio of 1:2, and tetrabutyl titanate catalyst was added to react; the temperature of the transesterification reaction was 80° C., and the reaction time was 4 h.

[0029] Next, the product after the transesterification reaction is subjected to polycondensation to generate a polysiloxane hydrophobic resin; wherein the temperature during the polycondensation is 120°C.

[0030] S4, preparing natural mineral pigments; First, the raw materials are pretreated; Hematite is selected as the natural mineral raw material, and the mineral is crushed to a particle size of less than 100 μm by wet ball milling. Then, particles of different sizes are separated by elutriation, and particles of 20 to 50 μm are retained as selected raw materials; Secondly, the selected raw materials are calcined at high temperature; The calcination temperature is 600-800° C., and the calcination time is 2-4 hours.

[0031] Next, the selected raw materials after high-temperature calcination are purified by acid leaching and then separated by ultrafiltration membrane to obtain Fe³⁺ solution; Among them, when the Fe³⁺ solution is separated by ultrafiltration membrane, a ceramic membrane with a pore size of 0.1 μm is used to intercept undissolved mineral residues, and the solution is concentrated by nanofiltration membrane to a Fe³⁺ concentration of ≥10%.

[0032] Next, Fe³⁺ solution and urea are hydrothermally synthesized at 80-100°C to generate nano-sized α-Fe2O3 particles; Finally, nano-sized α-Fe2O3 particles were encapsulated in chitosan using a complex coacervation method; S5. Add a waterproofing agent, a dispersant, an anti-ultraviolet agent, and a natural mineral pigment to the synthetic resin emulsion and stir under controlled temperature to obtain a repair agent emulsion; Among them, tannic acid is used as the anti-ultraviolet agent; the temperature of the temperature control stirring is 25°C, and a magnetic stirrer is used, and the stirring time is 2 hours.

[0033] S6. Adjust the pH of the repair agent emulsion to 7.5-8.0; S7. Use a 0.22 μm ceramic membrane to filter the repair agent emulsion to remove undispersed particles to obtain the finished repair agent, and then package and store the finished repair agent.

[0034] In Test Example 1, based on the preparation process of the embodiment, the raw materials selected by mass percentage are: 65% synthetic resin emulsion, 22% dispersant, 5% water repellent, 3% anti-ultraviolet agent, and 5% natural mineral pigment. In Test Example 2, based on the preparation process of the embodiment, the raw materials selected by mass percentage are: 60% synthetic resin emulsion, 25% dispersant, 7% water repellent, 4% anti-ultraviolet agent, and 4% natural mineral pigment.

[0035] The performance of the repair agents prepared from the two components of Test Example 1 and Test Example 2 was tested. The test items included curing time, adhesion, UV aging resistance, and biological toxicity. The test results are shown in Table 1.

[0036] Table 1

[0037] The above description is only an embodiment of the present invention and does not limit the scope of the present invention. Any equivalent structure or equivalent process transformation made by utilizing the contents of the present invention specification, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A building concrete base color difference repair agent, characterized in that: The invention is prepared from the following raw materials in percentage by mass: 55-65% of synthetic resin emulsion, 22-25% of dispersant, 5-8% of waterproofing agent, 2-4% of anti-ultraviolet agent and 3-5% of natural mineral pigment.

2. A preparation process of a building concrete base color difference repair agent, used to prepare a building concrete base color difference repair agent according to claim 1, characterized in that: The following steps are involved: S1, preparing synthetic resin emulsion; First, select the following raw materials according to mass percentage: Bio-based acrylate monomer 30-40%, water-based epoxy resin 18-25%, nano-silica 5-8%, non-ionic emulsifier 8-12%, UV initiator 1-2%, deionized water 10-15%, ammonium persulfate 1-2%, dodecyl mercaptan 1-3%; Secondly, bio-based acrylate monomer, ammonium persulfate and dodecyl mercaptan were added to the reactor to initiate free radical polymerization; Next, a nonionic emulsifier is added into the reactor to form a preliminary emulsion; Next, water-based epoxy resin and nano-silica are added to the preliminary emulsion, stirred at high speed to achieve uniform dispersion, and then a UV initiator is introduced and cured under UV light; Finally, the solidified emulsion is filtered through an ultrafiltration membrane to remove unreacted monomers, deionized water is added, and the emulsion is bottled under nitrogen protection. S2, preparing a dispersant; First, sugarcane bagasse, concentrated sulfuric acid, ammonia water and purified water are selected as raw materials; Secondly, sugarcane bagasse is hydrothermally carbonized with concentrated sulfuric acid to generate carbon quantum dot precursors; Next, the pH of the carbon quantum dot precursor was adjusted to 8-9 with ammonia water, and the precursor was dispersed in pure water after centrifugal purification. S3, preparing a waterproofing agent and modifying it; First, castor oil, γ-aminopropyltriethoxysilane, and tetrabutyl titanate catalyst were selected as raw materials; Secondly, transesterification reaction is carried out; Castor oil and γ-aminopropyltriethoxysilane are mixed in a molar ratio of 1:2, and tetrabutyl titanate catalyst is added to react; Next, the product after the transesterification reaction is subjected to polycondensation to generate a polysiloxane hydrophobic resin; S4, preparing natural mineral pigments; First, the raw materials are pretreated; Hematite is selected as the natural mineral raw material, and the mineral is crushed to a particle size of less than 100 μm by wet ball milling. Then, particles of different sizes are separated by elutriation, and particles of 20 to 50 μm are retained as selected raw materials; Secondly, the selected raw materials are calcined at high temperature; Next, the selected raw materials after high-temperature calcination are purified by acid leaching and then separated by ultrafiltration membrane to obtain Fe³⁺ solution; Next, Fe³⁺ solution and urea are hydrothermally synthesized at 80-100°C to generate nano-sized α-Fe2O3 particles; Finally, nano-sized α-Fe2O3 particles were encapsulated in chitosan using a complex coacervation method; S5. Add a waterproofing agent, a dispersant, an anti-ultraviolet agent, and a natural mineral pigment to the synthetic resin emulsion and stir under controlled temperature to obtain a repair agent emulsion; Among them, tannic acid is used as the anti-ultraviolet agent; S6. Adjust the pH of the repair agent emulsion to 7.5-8.0; S7. Use a 0.22 μm ceramic membrane to filter the repair agent emulsion to remove undispersed particles to obtain the finished repair agent, and then package and store the finished repair agent.

3. The preparation process of a building concrete base color difference repairing agent according to claim 2, characterized in that: In the step S1, the temperature in the reactor is controlled at 70-80° C. when initiating free radical polymerization, and 365 nm ultraviolet light is used for ultraviolet curing of the emulsion for 5 minutes.

4. The preparation process of a building concrete base color difference repairing agent according to claim 2, characterized in that: In step S2, when the sugarcane bagasse and concentrated sulfuric acid are subjected to hydrothermal carbonization reaction, the mass ratio of the sugarcane bagasse to the concentrated sulfuric acid is 1:3, the reaction temperature is 600° C., and the reaction time is 6 hours.

5. The preparation process of a building concrete base color difference repairing agent according to claim 2, characterized in that: In step S2, the pH of the carbon quantum dot precursor is adjusted to 8-9 with ammonia water, and the concentration is adjusted to 2 mg / mL when dispersed in pure water after centrifugal purification.

6. The preparation process of a building concrete base color difference repair agent according to claim 2, characterized in that: The temperature of the transesterification reaction in step S3 is 80° C., and the reaction time is 4 hours.

7. The preparation process of a building concrete base color difference repair agent according to claim 2, characterized in that: The temperature for polycondensing the product after the transesterification reaction in step S3 is 120°C.

8. The preparation process of a building concrete base color difference repair agent according to claim 2, characterized in that: In the step S4, when the selected raw materials are calcined at high temperature, the calcination temperature is 600-800° C. and the calcination time is 2-4 hours.

9. The preparation process of a building concrete base color difference repair agent according to claim 2, characterized in that: When the Fe³⁺ solution is subjected to ultrafiltration membrane separation in step S4, a ceramic membrane with a pore size of 0.1 μm is used to intercept undissolved mineral residues, and the solution is concentrated to an Fe³⁺ concentration of ≥10% by a nanofiltration membrane.

10. The preparation process of a building concrete base color difference repairing agent according to claim 2, characterized in that: When the mixture is stirred under controlled temperature in step S5, the temperature is 25° C., a magnetic stirrer is used, and the stirring time is 2 h.

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