A fair-faced concrete protective agent and preparation method thereof

Abstract

The application relates to the technical field of building materials, and particularly discloses a fair-faced concrete protective agent, which comprises epoxy acrylic acid / phenylpropyl blended emulsion 40-55 parts by weight, epoxy-based modified inorganic fillers 40-55 parts by weight and fluorosilane coupling agents and the like characteristic materials, and further comprises at least one of commonly used additives, namely film forming additives, pH regulators, wetting agents, defoaming agents, leveling agents, drying catalysts, light stabilizers, anti-freezing agents and thickening agents, and a preparation method of the fair-faced concrete protective agent is further provided. The inorganic matter and the organic matrix in the fair-faced concrete protective agent are coupled with each other, the mechanical property of the coating film is good, the salt resistance, acid and alkali resistance and high and low temperature aging performance are good, the shortcoming that the concrete protective agent is prone to peeling is overcome, the cement concrete component can be effectively protected, and the color of the fair-faced cement is reflected.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a protective agent for fair-faced concrete and its preparation method. Background Technology

[0002] In recent years, with my country's policy guidance on carbon emissions and carbon neutrality, fair-faced concrete structures have seen significant development as a representative of low-carbon and energy-saving buildings. However, fair-faced concrete components often suffer from unavoidable defects such as micro-cracks, color differences, and formwork marks, which seriously affect their environmental damage resistance and appearance. To address this, fair-faced concrete finishing coatings have emerged. These coatings provide protection and decoration for concrete structures and are widely used in highways, railways, bridges, factory buildings, and many other fields. Fair-faced concrete exposed to the atmosphere is susceptible to erosion and damage from water vapor, carbon dioxide, and ultraviolet radiation, thus affecting its lifespan and quality. Currently, concrete corrosion and damage resistance mainly include four mechanisms: surface film formation, pore sealing, hydrophobic impregnation, and multifunctional surface treatment. Since concrete requires a fair-faced appearance and the ability to conceal cracks, color differences, and formwork marks, the development of multifunctional fair-faced concrete coatings is essential. Currently, construction typically involves initial necessary anti-corrosion treatments, such as pore sealing and hydrophobic impregnation, followed by conventional outdoor coating decoration. Existing market products include fair-faced concrete protective coatings based on cement sealants, cement color difference adjusting coatings, and cement surface film-forming coatings. These are independent products developed based on traditional coating and finishing processes. Due to their low technological content, they often suffer from poor compatibility between the sealing layer, color difference adjusting layer, and surface film-forming coating layer, leading to difficulties in construction. Furthermore, there are no relevant patents. Developing an easy-to-apply fair-faced cement coating that addresses the technical challenges of poor compatibility with cement or functional layers, achieving convenient construction, meeting standard requirements, and saving time, effort, and money, is a necessary requirement and result of technological innovation. Therefore, we propose a fair-faced concrete protective agent and its preparation method. Summary of the Invention

[0003] The purpose of this invention is to provide a protective agent for fair-faced concrete and its preparation method, thereby solving the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a protective agent for fair-faced concrete, comprising 40-55 parts by weight of a water-based styrene-acrylic emulsion and an epoxy acrylic mixed emulsion, 40-55 parts by weight of a modified inorganic filler, 0.1-3 parts by weight each of a film-forming aid, a pH adjuster, a wetting agent, a defoamer, a leveling agent, a light stabilizer, an antifreeze agent, a thickener, and deionized water, and 0.02-0.03 parts by weight of a perfluoroalkyl silane coupling agent.

[0005] A method for preparing a protective agent for fair-faced concrete includes the following steps:

[0006] S1: Prepare a silane coupling agent ethanol solution with a concentration of 20-50%. The steps for preparing the silane coupling agent ethanol solution are as follows: add KH550 silane coupling agent to the ethanol solution, mix evenly, and then add a small amount of ammonia water to obtain mixed solution A. Add KH560 silane coupling agent to another part of the ethanol solution to obtain mixed solution B.

[0007] S2: Add inorganic filler to a high-speed mixer, and while stirring at medium speed, spray equal amounts of mixed solution A and mixed solution B from step S1. The total amount of mixed solution A and mixed solution B accounts for 10-20 wt% of the amount of inorganic filler. After completion, stir at high speed for 15 minutes, let stand for 12-24 hours, and dry off the ethanol to obtain the modified inorganic filler with glycerol ether group and amino group.

[0008] S3: Add deionized water, the modified inorganic filler with glycerol ether and amino groups obtained in step S2, wetting agent, pH adjuster, defoamer, light stabilizer and antifreeze to the container according to the formula ratio. In step S3, only 50% of the original amount of defoamer is added. Stir at medium speed for 10 minutes and then stir at high speed for 30 minutes.

[0009] S4: Pour the aqueous styrene-acrylic emulsion, the epoxy acrylic emulsion, and the perfluoroalkyl silane coupling agent into another container for blending. Stir at medium speed for 30 minutes and let stand for 12-24 hours to obtain the blended emulsion.

[0010] S5: Add the blended emulsion obtained in step S4 to the corresponding container in step S3, add the remaining defoamer, leveling agent and thickener in the formula ratio, and disperse at low to medium speed to obtain the fair-faced concrete protective agent.

[0011] Preferably, the aqueous styrene-acrylic emulsion accounts for 40% to 60% of the total amount of the aqueous styrene-acrylic emulsion and the epoxy acrylic emulsion, and the epoxy acrylic accounts for 40% to 60% of the total amount of the aqueous styrene-acrylic emulsion and the epoxy acrylic emulsion.

[0012] Preferably, the modified inorganic filler is a modified inorganic filler with glycerol ether groups and amino groups, and the inorganic filler includes any two or more of rutile titanium dioxide, wollastonite, barium sulfate and calcined kaolin.

[0013] Preferably, the film-forming aid is any one of propylene glycol phenyl ether, propylene glycol butyl ether, and dodecyl alcohol ester.

[0014] More preferably, the film-forming aid is dodecyl alcohol ester.

[0015] Preferably, the pH adjuster is AMP-95 pH adjuster.

[0016] Preferably, the wetting agent is ammonium acrylate.

[0017] Preferably, the defoamer is an organosilicone defoamer.

[0018] Preferably, the leveling agent is KYC-615 leveling agent.

[0019] Preferably, the light stabilizer is UV-1130 light stabilizer.

[0020] Preferably, the antifreeze agent is any one of 1,3-propylene glycol, 1,2-propylene glycol, and propylene glycol methyl ether.

[0021] More preferably, the antifreeze agent is propylene glycol methyl ether.

[0022] Preferably, the thickener includes alkali-soluble thickeners and polyurethane thickeners.

[0023] Preferably, the perfluorosilane coupling agent is any one of tridecafluorooctyltriethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane.

[0024] More preferably, the perfluorosilane coupling agent is tridecylfluorooctyltriethoxysilane.

[0025] Preferably, the surface group type of the modified inorganic filler with glycerol ether and amino groups is any one of the following: all-glycerol ether, all-amino, or a mixture of glycerol ether and amino groups.

[0026] Preferably, the emulsification systems of the aqueous styrene-acrylic emulsion and the epoxy acrylic emulsion are the same, and the pH value of the epoxy acrylic emulsion is equal to that of the aqueous styrene-acrylic emulsion.

[0027] Preferably, low-speed mixing is below 500 rpm, medium-speed mixing is 500-1000 rpm, and high-speed mixing is 1200-1500 rpm.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. The technical solution of this application improves the interaction between the epoxy groups in the blended emulsion and cement by utilizing the epoxy groups in the blended emulsion. Due to its good compatibility with styrene-acrylic emulsion, the whole system has good adhesion to cement, which can give full play to the acid and alkali resistance of styrene-acrylic emulsion and has the advantages of low cost.

[0030] 2. The technical solution of this application activates and modifies the filler to form an organic-inorganic hybrid network in the cured coating system. This network interpenetrates with the blended emulsion, increasing the strength of the coating, avoiding the possibility of microcracks, and thus improving the ability to block carbon dioxide penetration.

[0031] 3. The technical solution of this application introduces a fluoroalkylsilane coupling agent, which utilizes its low surface energy to seal some of the new water groups in the coating after hydrolysis, and utilizes its strong electronegativity to enhance water resistance and salt resistance. Attached Figure Description

[0032] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0033] Figure 1 It is a reaction formula for preparing amination-modified inorganic fillers.

[0034] Figure 2 It is a reaction formula for preparing glycerol-based inorganic fillers.

[0035] Figure 3 This is a diagram of the network reaction mechanism of organic-inorganic fillers. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0037] This invention provides a technical solution: a protective agent for fair-faced concrete includes an aqueous styrene-acrylic emulsion with a solid content of 40%~60% and an epoxy acrylic emulsion with a solid content of 40%~60%; inorganic fillers are rutile titanium dioxide, barium sulfate, and wollastonite, with the ratio of rutile titanium dioxide, barium sulfate, and wollastonite being 1:2:5; pH adjuster is AMP-95, wetting and dispersing agent is SN-5040, leveling agent is KYC-615, antifreeze agent is propylene glycol butyl ether, thickener is RM8W, defoamer is an organosilicon defoamer, and silane coupling agents are KH550, KH560, and tridecafluorooctyltriethoxysilane.

[0038] Example 1: The preparation method of the water-based cement protective coating is as follows:

[0039] S1: Add 50 ml of KH550 silane coupling agent to 125 ml of ethanol solution, mix well, and then add 1 ml of ammonia water; take another 125 ml of ethanol solution and add 50 ml of KH560 silane coupling agent.

[0040] S2: Add 1000g of mixed inorganic filler to a high-speed mixer, and spray KH550 ethanol solution first while stirring at 400 rpm, followed by KH560 ethanol solution. After spraying, stir at 1500 rpm for 15 minutes, let stand for 12-24 hours, and dry off the ethanol to obtain the modified inorganic filler with glycerol ether group and amino group.

[0041] S3: Add 100g of deionized water, 400g of modified inorganic filler powder, 1.5g of wetting agent, 10g of pH adjuster, 2g of defoamer (partial), 0.1g of light stabilizer, and 15g of antifreeze to a container, stir at 400 rpm for 10 minutes, and then stir at 1500 rpm for 30 minutes.

[0042] S4: Pour 300g of waterborne styrene-acrylic emulsion and 200g of epoxy acrylic emulsion prepared by the same emulsification system into another container for mixing, stir at 400 rpm for 30 minutes, and let stand for 12-24 hours.

[0043] S5: Take 480g of the mixed emulsion from S4 and add it to the mixture from S3. At the same time, add 10g of tridecafluorooctyltriethoxysilane. After mixing for 10 minutes, add 2g of defoamer, 20g of leveling agent and 20g of thickener. Shear and disperse at 400 rpm to obtain the fair-faced concrete protective agent.

[0044] Example 2, the preparation method of the water-based cement protective coating is as follows:

[0045] S1: Prepare modified inorganic fillers according to the method in Example 1;

[0046] S2: Add 100g of deionized water, 400g of modified inorganic filler powder, 1.5g of wetting agent, 10g of pH adjuster, 2g of defoamer (partial), 0.1g of light stabilizer, and 15g of antifreeze to a container, stir at 400 rpm for 10 minutes, and then stir at 1500 rpm for 30 minutes.

[0047] S3: Pour 300g of styrene-acrylic emulsion and 300g of epoxy-acrylic emulsion prepared by the same emulsification system into another container for mixing, stir at 400 rpm for 30 minutes, and let stand for 12-24 hours.

[0048] S4: Add 480g of emulsion to the mixture of S3, and simultaneously add 10g of tridecafluorooctyltriethoxysilane. After mixing for 10 minutes, add 2g of defoamer, 20g of leveling agent and 20g of thickener. Shear and disperse at 400 rpm to obtain the fair-faced concrete protective agent.

[0049] Example 3: The preparation method of the water-based cement protective coating is as follows:

[0050] S1: Prepare modified inorganic fillers according to the method in Example 1:

[0051] S2: Add 100g of deionized water, 500g of modified inorganic filler powder, 1.5g of wetting agent, 10g of pH adjuster, 2g of defoamer (partial), 0.1g of light stabilizer, and 15g of antifreeze to a container, stir at 400 rpm for 10 minutes, and then stir at 1500 rpm for 30 minutes.

[0052] S3: Pour 200g of waterborne styrene-acrylic emulsion and 300g of epoxy acrylic emulsion prepared by the same emulsification system into another container for mixing, stir at 400 rpm for 30 minutes, and let stand for 12-24 hours.

[0053] S4: Add 480g of emulsion to the mixture of S3, and simultaneously add 15g of tridecafluorooctyltriethoxysilane. After mixing for 10 minutes, add 2g of defoamer, 20g of leveling agent and 20g of thickener. Shear and disperse at 400 rpm to obtain the fair-faced concrete protective agent.

[0054] Example 4,

[0055] S1: Prepare modified inorganic fillers according to the method in Example 1:

[0056] S2: Add 100g of deionized water, 500g of modified inorganic filler powder, 1.5g of wetting agent, 10g of pH adjuster, 2g of defoamer (partial), 0.1g of light stabilizer, and 15g of antifreeze to a container, stir at 400 rpm for 10 minutes, and then stir at 1500 rpm for 30 minutes.

[0057] S3: Add 480g of epoxy acrylic emulsion to the mixture of S2, and simultaneously add 15g of tridecafluorooctyltriethoxysilane. After mixing for 10 minutes, add 2g of defoamer, 20g of leveling agent and 20g of thickener. Shear and disperse at 400 rpm to obtain the fair-faced concrete protective agent.

[0058] Comparative Example 1,

[0059] The main difference between Comparative Example 1 and Example 1 is that the emulsion was replaced with 480g of pure styrene-acrylic emulsion to prepare a protective agent for fair-faced concrete.

[0060] Comparative Example 2,

[0061] The main difference between Comparative Example 2 and Example 1 is that the amount of modified inorganic filler was changed to 500g, and the emulsion was changed to 480g of pure styrene-acrylic emulsion to prepare a protective agent for fair-faced concrete.

[0062] Comparative Example 3,

[0063] The main difference between Comparative Example 3 and Example 1 is that the inorganic filler is used directly without modification.

[0064] Comparative Example 4,

[0065] The main difference between Comparative Example 4 and Example 1 is that no tridecafluorooctyltriethoxysilane was added.

[0066] The water resistance of the coating film was tested according to GB / T1733-1993. The salt spray resistance of the coating film was tested according to GB / T10125-2021, the alkali resistance of the coating was tested according to GB / T9265-2009 Standard for Determination of Alkali Resistance of Architectural Coatings, and the acid resistance of the coating was tested according to GB / T9274-1988. The water resistance and salt spray resistance test results of the above water-based environmentally friendly anti-corrosion coatings are shown in Table 1 below.

[0067] Table 1. Tests on the water resistance, salt spray resistance, and acid and alkali resistance of clear water cement coatings.

[0068] Performance Samples Water resistance (720h) Salt spray resistance (3% NaCl, 168h) Acid resistance (3% sulfuric acid, 168h) Alkali resistance (3% NaOH, 720h) Example 1 No abnormalities No abnormalities No abnormalities No abnormalities Example 2 No abnormalities No abnormalities No abnormalities No abnormalities Example 3 No abnormalities No abnormalities No abnormalities No abnormalities Example 4 No abnormalities No abnormalities No abnormalities No abnormalities Comparative Example 1 No abnormalities No abnormalities No abnormalities No abnormalities Comparative Example 2 No abnormalities Surface roughening No abnormalities No abnormalities Comparative Example 3 No abnormalities Surface roughening Local thickening Local thickening Comparative Example 4 No abnormalities Surface roughening slight changes slight changes

[0069] After testing, the concrete protective agents of Examples 1-4 of this invention generally showed good results. The fundamental reason is twofold: firstly, the epoxy in the blended emulsion has good interfacial interaction with cement, and also reacts with the amino groups in the inorganic powder, resulting in good overall system compatibility; secondly, the inorganic filler, through activation, may assemble into an organic-inorganic cross-linked network, increasing the overall strength of the system, making it less prone to cracking and forming microcracks, and further preventing the penetration of harmful ions from water, acids, alkalis, and salts, thereby improving the coating quality.

[0070] Comparative Example 1 did not contain any epoxy groups, but the formulation used a large amount of epoxy coupling agent, which partially acted as an epoxy acrylic emulsion, increasing the interaction with the surface of the cement and improving the strength of the emulsion coating, thus resulting in better performance.

[0071] Comparative Example 2 only increased the amount of modified filler-free material, and the results were similar to those of Comparative Example 1, which also shows that the epoxy-modified inorganic powder played a good synergistic role.

[0072] Comparative Example 3 used unmodified inorganic fillers, which had an incompatible interface with the matrix, resulting in a significant decrease in performance.

[0073] Comparative Example 4 only removed the fluorosilane surfactant, indicating that the fluorinated group has a significant impact on the penetration of chloride ions.

[0074] The present application has been described in detail above with reference to the embodiments, but the present application is not limited to the above embodiments. The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, 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. A protective agent for fair-faced concrete, characterized in that: include 40-55 parts by weight of a mixed emulsion of waterborne styrene-acrylic emulsion and epoxy-acrylic acid; 40-55 parts by weight of modified inorganic filler; Film-forming aid, pH adjuster, wetting agent, defoamer, leveling agent, light stabilizer, antifreeze agent, thickener and deionized water, 0.1-3 parts by weight each; perfluoroalkyl silane coupling agent, 0.02-0.03 parts by weight. The modified inorganic filler is a modified inorganic filler with glycerol ether group and amino group, and the inorganic filler includes any two or more of rutile titanium dioxide, wollastonite, barium sulfate and calcined kaolin. The film-forming aid is any one of propylene glycol phenyl ether, propylene glycol butyl ether, and dodecyl alcohol ester; The antifreeze agent is any one of 1,3-propylene glycol, 1,2-propylene glycol, and propylene glycol methyl ether. The perfluoroalkyl silane coupling agent is any one of tridecafluorooctyltriethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, and heptadecafluorodecyltriethoxysilane.

2. The fair-faced concrete protective agent according to claim 1, characterized in that: The aqueous styrene-acrylic emulsion accounts for 40% to 60% of the total amount of the aqueous styrene-acrylic emulsion and the epoxy acrylic emulsion, and the epoxy acrylic emulsion accounts for 40% to 60% of the total amount of the aqueous styrene-acrylic emulsion and the epoxy acrylic emulsion.

3. The fair-faced concrete protective agent according to claim 1, wherein the pH adjuster is AMP-95 pH adjuster, the wetting agent is ammonium acrylate, the defoamer is silicone defoamer, the leveling agent is KYC-615 leveling agent, the light stabilizer is UV-1130 light stabilizer, and the thickener includes alkali-soluble thickener and polyurethane thickener.

4. The protective agent for fair-faced concrete according to claim 1, characterized in that: The film-forming aid is dodecyl alcohol ester.

5. The fair-faced concrete protective agent according to claim 1, characterized in that: The antifreeze agent is propylene glycol methyl ether.

6. The protective agent for fair-faced concrete according to claim 1, characterized in that: The perfluorosilane coupling agent is tridecafluorooctyltriethoxysilane.

Images