Concrete protective coating and preparation method thereof

Abstract

The invention discloses a concrete protective paint and a preparation method thereof, and belongs to the technical field of building paints.The concrete protective paint comprises a component A and a component B. The component A comprises, by weight, 10 parts of potassium silicate, 2-3 parts of an emulsifier, 2.5 parts of nano-silica, 0.5 part of triethanolamine, 20 parts of a silane coupling agent and 4-5 parts of a curing agent; the component B is prepared from the following raw materials in parts by weight: 12 parts of aluminum dihydrogen phosphate, 1.5 parts of magnesium oxide, 10 parts of potassium silicate, 15 parts of light calcium carbonate, 2-5 parts of composite filler, 10-15 parts of epoxy hybrid acrylic emulsion and 20 parts of water, the protective coating is simple in preparation method and convenient to use, the double effects of permeation and blocking are combined, the protective effect is greatly improved, and the protective coating is friendly to the environment and human bodies.

Description

Technical Field

[0001] The invention belongs to the technical field of building coatings, and in particular relates to concrete protective coatings and a preparation method thereof. Background Art

[0002] Concrete has been widely used in various fields such as roads, bridges, hydropower projects, and seaports. However, concrete is a porous material, and water and corrosive media can easily penetrate into it, causing corrosion damage, thereby reducing its service life. To this end, there are currently two main ways to increase the service life of concrete: one is to reasonably adjust the raw material ratio of concrete to improve the density and stability of the concrete itself; the other is to apply certain concrete protective materials on the surface of concrete to prevent erosion by harmful substances in the environment. The second method is currently the most direct, effective, and economical method.

[0003] At present, concrete protective coatings include epoxy resin, polyurethane, acrylate, chlorinated rubber and ethylene rubber, but these traditional protective coatings have their own shortcomings that are difficult to overcome, such as poor alkali resistance, low adhesion, weather resistance and other problems, and are not effective in practical applications. Summary of the invention

[0004] The purpose of the present invention is to provide a concrete protective coating and a preparation method thereof, so as to solve the problem that the existing concrete protective coating has poor effect in practical application.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A concrete protective coating, comprising a component A and a component B, wherein the mass ratio of the component A to the component B is 1:1;

[0007] The component A comprises the following raw materials in parts by weight: 10 parts of potassium silicate, 2-3 parts of emulsifier, 2.5 parts of nano silicon dioxide, 0.5 parts of triethanolamine, 20 parts of silane coupling agent and 4-5 parts of curing agent;

[0008] The B component comprises the following raw materials in parts by weight: 12 parts of aluminum dihydrogen phosphate, 1.5 parts of magnesium oxide, 10 parts of potassium silicate, 15 parts of light calcium carbonate, 2-5 parts of composite filler, 10-15 parts of epoxy hybrid acrylic emulsion, and 20 parts of water.

[0009] The silane coupling agent is composed of isobutyltriethoxysilane and long carbon chain silane in a mass ratio of 1-2:1.

[0010] Furthermore, the long carbon chain silane is a product obtained by a Schiff base reaction between triethoxysilyl butyraldehyde and a long chain alkylamine.

[0011] The composite filler is a composite product of layered double metal hydroxide and metal organic framework.

[0012] Furthermore, the layered double metal hydroxide is a magnesium-aluminum layered double metal hydroxide.

[0013] Furthermore, the metal organic framework is U i O-66-NH 2 .

[0014] Furthermore, the preparation method of the long carbon chain silane comprises the following steps:

[0015] Anhydrous ethanol, triethoxysilyl butyraldehyde and long-chain alkylamine are added into a flask, and the temperature is raised to 80° C. under nitrogen protection, and stirred for reaction for 6-8 hours. After the reaction is completed, the anhydrous ethanol is removed by rotary evaporation to obtain the long carbon chain silane.

[0016] Furthermore, the molar ratio of triethoxysilylbutyraldehyde to long-chain alkylamine is 1-1.1:1.

[0017] Furthermore, the chemical structural formula of the long-chain alkylamine is: R-NH2, wherein R is a C6-C18 straight-chain or branched-chain alkyl group.

[0018] Furthermore, the long-chain alkylamine is at least one of octadecylamine, hexadecylamine and tetradecylamine.

[0019] Furthermore, the preparation method of the composite filler comprises the following steps:

[0020] The magnesium aluminum layered double hydroxide was added to DMF, and after ultrasonic dispersion for 30 minutes, zirconium tetrachloride and 2-aminoterephthalic acid were added, and after stirring for 1 hour, the mixture was transferred to a reactor and reacted at 120° C. for 48 hours. After the reaction was completed, the mixture was naturally cooled to room temperature, filtered, and the filter cake was washed with methanol for 6 times, and then dried at 80° C. for 24 hours to obtain the composite filler.

[0021] Furthermore, the usage ratio of magnesium aluminum layered double hydroxide, DMF, zirconium tetrachloride and 2-aminoterephthalic acid is 5-7g:3-5L:23.32g:18.12g.

[0022] Furthermore, the sheet diameter of the magnesium aluminum layered double hydroxide is 1-4 um, and is preferably the MgA l-LDH two-dimensional layered double hydroxide produced by Xi'an Qiyue Biotechnology Co., Ltd.

[0023] Furthermore, the epoxy value of the epoxy hybrid acrylic emulsion is 500-800 mgKOH / g, and is preferably Dow AEH-20 water-based acrylic epoxy hybrid emulsion.

[0024] Furthermore, the emulsifier is at least one of Tween 80, Span 80 and potassium stearate.

[0025] Furthermore, the curing agent is at least one of T-403 polyetheramine and D2000 polyetheramine.

[0026] The preparation method of the above concrete protective coating comprises the following steps:

[0027] S1. Add potassium silicate, emulsifier, nano-silicon dioxide, triethanolamine, hydrophobic silane and curing agent in the raw materials of component A into a mixer, and stir and mix at a speed of 1000-1500 r / min for 20-30 min to obtain component A;

[0028] S2. Add potassium dihydrogen phosphate, magnesium oxide, potassium silicate, light calcium carbonate, composite filler, epoxy hybrid acrylic emulsion and water in the raw materials of component B into a mixer, and stir and mix at a speed of 500-600 r / min for 0.5-1 h to obtain component B.

[0029] Beneficial effects of the present invention:

[0030] The present invention provides a concrete protective coating, comprising component A and component B. The silane coupling agent of component A can penetrate into the interior of the concrete, and under the action of moisture in the air, hydrolyze to generate silanol, which condenses with hydroxyl groups on the surface of the concrete or condenses itself to form a water-repellent layer. In particular, the effect of long carbon chain silane is more obvious, and its longer hydrophobic chain significantly improves the water resistance of the coating. The molecular chain contains a C=N bond and an unsaturated bond containing heteroatoms as an ultraviolet chromophore, which strengthens the shielding function of the coating against ultraviolet light and significantly improves the weather resistance of the coating.

[0031] The silicate and nano-silicon dioxide in the two components can react with Ca(OH)2 on the surface of concrete, refine Ca(OH)2 grains, and generate calcium silicate hydrate (CSH) gel with strong bonding ability and large specific surface area, thus improving the bonding between the coating and concrete and effectively improving the durability of concrete.

[0032] Aluminum dihydrogen phosphate and magnesium oxide in component B combine to produce a hardening reaction, which effectively improves the hygroscopic resistance of the coating. The composite filler is a magnesium-aluminum layered double hydroxide with U iO-66-NH2 loaded on the surface. Compared with a single layered double hydroxide or metal organic framework, it has a larger size and better dispersibility in the coating. It also contains active amine groups on the surface, which can react with epoxy hybrid acrylic emulsion to increase the crosslinking density inside the coating. Combined with the excellent barrier properties and chloride ion adsorption and carbonate adsorption properties of the layered double hydroxide, and the good carbon dioxide adsorption properties of U iO-66-NH2, not only the density of the coating is improved, but also the adverse effects of corrosive media such as chloride ions and carbon dioxide on concrete are reduced, effectively improving the concrete's resistance to chloride ion penetration and carbonization.

[0033] In summary, the protective coating of the present invention combines the dual functions of penetration and barrier, greatly improves the protective effect, and is friendly to the environment and the human body. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe 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 creative work are within the scope of protection of the present invention.

[0035] In the present application, the sheet diameter of the magnesium aluminum layered double hydroxide is 1-4 um, and it is MgA l-LDH two-dimensional layered double hydroxide produced by Xi'an Qiyue Biotechnology Co., Ltd., and the epoxy hybrid acrylic emulsion is Dow AEH-20 water-based acrylic epoxy hybrid emulsion.

[0036] Preparation Example 1

[0037] The steps for preparing the composite filler are as follows:

[0038] 5 g of magnesium aluminum layered double hydroxide was added to 3 L of DMF, and after ultrasonic dispersion for 30 min, 23.32 g of zirconium tetrachloride and 18.12 g of 2-aminoterephthalic acid were added, and after stirring for 1 h, the mixture was transferred to a reactor and reacted at 120° C. for 48 h. After the reaction was completed, the mixture was naturally cooled to room temperature and filtered. The filter cake was washed with methanol for 6 times and dried at 80° C. for 24 h to obtain the composite filler.

[0039] Preparation Example 2

[0040] The steps for preparing the composite filler are as follows:

[0041] 7 g of magnesium aluminum layered double hydroxide was added to 5 L of DMF, and after ultrasonic dispersion for 30 min, 23.32 g of zirconium tetrachloride and 18.12 g of 2-aminoterephthalic acid were added, and after stirring for 1 h, the mixture was transferred to a reactor and reacted at 120° C. for 48 h. After the reaction was completed, the mixture was naturally cooled to room temperature and filtered. The filter cake was washed with methanol for 6 times and dried at 80° C. for 24 h to obtain the composite filler.

[0042] Example 1

[0043] Concrete protective coating, the concrete protective coating comprises component A and component B, and the mass ratio of component A to component B is 1:1;

[0044] Component A includes the following raw materials in parts by weight: 10 parts of potassium silicate, 2 parts of Tween 80, 2.5 parts of nano-silicon dioxide, 0.5 parts of triethanolamine, 20 parts of silane coupling agent and 4 parts of T-403 polyetheramine;

[0045] Component B includes the following raw materials in parts by weight: 12 parts of aluminum dihydrogen phosphate, 1.5 parts of magnesium oxide, 10 parts of potassium silicate, 15 parts of light calcium carbonate, 2 parts of the composite filler of Preparation Example 1, 10 parts of epoxy hybrid acrylic emulsion, and 20 parts of water.

[0046] The silane coupling agent is composed of isobutyltriethoxysilane and long carbon chain silane in a mass ratio of 1:1.

[0047] The preparation method of long carbon chain silane comprises the following steps:

[0048] 500 mL of anhydrous ethanol, 0.1 mol of triethoxysilylbutyraldehyde and 1 mol of octadecylamine were added into a flask, and the temperature was raised to 80° C. under nitrogen protection, and stirred for reaction for 6 hours. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation to obtain the long carbon chain silane.

[0049] The preparation method of the above concrete protective coating comprises the following steps:

[0050] S1. Add potassium silicate, Tween 80, nano-silica, triethanolamine, hydrophobic silane and T-403 polyetheramine in the raw materials of component A into a mixer, and stir and mix at a speed of 1000 r / min for 20 min to obtain component A;

[0051] S2. Add potassium dihydrogen phosphate, magnesium oxide, potassium silicate, light calcium carbonate, composite filler, epoxy hybrid acrylic emulsion and water in the raw materials of component B into a mixer, and stir and mix at a speed of 500 r / min for 0.5 h to obtain component B.

[0052] Component A and component B are mixed in a mass ratio of 1:1.

[0053] Example 2

[0054] Concrete protective coating, the concrete protective coating comprises component A and component B, and the mass ratio of component A to component B is 1:1;

[0055] Component A includes the following raw materials by weight: 10 parts of potassium silicate, 2.5 parts of Span 80, 2.5 parts of nano-silicon dioxide, 0.5 parts of triethanolamine, 20 parts of silane coupling agent and 4.5 parts of D2000 polyetheramine;

[0056] Component B includes the following raw materials in parts by weight: 12 parts of aluminum dihydrogen phosphate, 1.5 parts of magnesium oxide, 10 parts of potassium silicate, 15 parts of light calcium carbonate, 3.5 parts of the composite filler of Preparation Example 2, 12 parts of epoxy hybrid acrylic emulsion, and 20 parts of water.

[0057] The silane coupling agent is composed of isobutyltriethoxysilane and long carbon chain silane in a mass ratio of 1.5:1.

[0058] The preparation method of long carbon chain silane comprises the following steps:

[0059] 800 mL of anhydrous ethanol, 0.1 mol of triethoxysilylbutyraldehyde and 1 mol of hexadecylamine were added into a flask, and the temperature was raised to 80° C. under nitrogen protection, and the mixture was stirred for reaction for 7 hours. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation to obtain the long carbon chain silane.

[0060] The preparation method of the above concrete protective coating comprises the following steps:

[0061] S1. Add potassium silicate, Span 80, nano-silica, triethanolamine, hydrophobic silane and D2000 polyetheramine in the raw materials of component A into a mixer, and stir and mix at a speed of 1200 r / min for 25 min to obtain component A;

[0062] S2. Add potassium dihydrogen phosphate, magnesium oxide, potassium silicate, light calcium carbonate, composite filler, epoxy hybrid acrylic emulsion and water in the raw materials of component B into a mixer, and stir and mix at a speed of 550 r / min for 0.8 h to obtain component B.

[0063] Component A and component B are mixed in a mass ratio of 1:1.

[0064] Example 3

[0065] Concrete protective coating, the concrete protective coating comprises component A and component B, and the mass ratio of component A to component B is 1:1;

[0066] Component A includes the following raw materials in parts by weight: 10 parts of potassium silicate, 3 parts of potassium stearate, 2.5 parts of nano silicon dioxide, 0.5 parts of triethanolamine, 20 parts of silane coupling agent and 5 parts of T-403 polyetheramine;

[0067] Component B includes the following raw materials in parts by weight: 12 parts of aluminum dihydrogen phosphate, 1.5 parts of magnesium oxide, 10 parts of potassium silicate, 15 parts of light calcium carbonate, 5 parts of the composite filler of Preparation Example 2, 15 parts of epoxy hybrid acrylic emulsion, and 20 parts of water.

[0068] The silane coupling agent is composed of isobutyltriethoxysilane and long carbon chain silane in a mass ratio of 2:1.

[0069] The preparation method of long carbon chain silane comprises the following steps:

[0070] 1000 mL of anhydrous ethanol, 0.11 mol of triethoxysilylbutyraldehyde and 1 mol of tetradecylamine were added into a flask, and the temperature was raised to 80° C. under nitrogen protection, and the mixture was stirred for reaction for 8 hours. After the reaction was completed, the anhydrous ethanol was removed by rotary evaporation to obtain the long carbon chain silane.

[0071] The preparation method of the above concrete protective coating comprises the following steps:

[0072] S1. Add potassium silicate, potassium stearate, nano-silicon dioxide, triethanolamine, hydrophobic silane and T-403 polyetheramine in the raw materials of component A into a mixer, and stir and mix at a speed of 1500 r / min for 30 min to obtain component A;

[0073] S2. Add potassium dihydrogen phosphate, magnesium oxide, potassium silicate, light calcium carbonate, composite filler, epoxy hybrid acrylic emulsion and water in the raw materials of component B into a mixer, and stir and mix at a speed of 600 r / min for 1 hour to obtain component B.

[0074] Component A and component B are mixed in a mass ratio of 1:1.

[0075] Comparative Example 1

[0076] The concrete protective coating is different from Example 1 in that the long carbon chain silane in Example 1 is replaced by an equal weight portion of isobutyltriethoxysilane.

[0077] Comparative Example 2

[0078] The concrete protective coating is different from Example 1 in that the composite filler in Example 1 is replaced by a mixture of equal parts of magnesium-aluminum layered double hydroxide and U iO-66-NH 2 in a mass ratio of 1:8.

[0079] Comparative Example 3

[0080] The concrete protective coating is different from Example 1 in that the composite filler in Example 1 is replaced by an equal weight portion of magnesium-aluminum layered double metal hydroxide.

[0081] Comparative Example 4

[0082] The concrete protective coating is different from Example 1 in that the composite filler in Example 1 is replaced by an equal weight portion of U i O-66-NH 2.

[0083] The concrete protective coatings obtained from Examples 1 to 3 and Comparative Examples 1 to 4 were tested, and the strength grade of the concrete test blocks was C30. The test process was as follows:

[0084] Aging resistance: refer to JG / T 337-2011 "Penetrating coatings for concrete structure protection", put the specimens in 3.3 into the QUV aging instrument, and irradiate with QUV-A ultraviolet light at an intensity of 1.5W / m 2 , the temperature is 50℃, after 1000h of UV irradiation, the water absorption ratio of the test specimen is tested (general environment);

[0085] Chloride ion penetration resistance evaluation: The concrete penetration resistance test adopts the electric flux method, which is carried out in accordance with GB / T50082-2009 "Standard for Test Methods of Long-term Performance and Durability of Ordinary Concrete";

[0086] Carbonation resistance evaluation: refer to JG / T 335-2011 "Film-forming coatings for concrete structure protection" to test the carbonation depth ratio for evaluation;

[0087] The test results are shown in Table 1:

[0088] Table 1

[0089]

[0090]

[0091] It can be seen from the test results in Table 1 that the concrete protective coating prepared by the present invention has good water repellency, weather resistance, resistance to chloride ion penetration and carbonization resistance. Specifically, it can be seen from the test results of Example 1 and Comparative Example 1 that the absence of long carbon chain silane will cause a significant decrease in the water repellency and weather resistance of the protective coating, and the change in the preparation method of the composite filler and the absence of magnesium-aluminum layered double metal hydroxide or U i O-66-NH2 will cause the protective coating to significantly reduce the resistance to chloride ion penetration and carbonization.

[0092] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0093] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A concrete protective coating, characterized in that: The method comprises component A and component B, wherein component A comprises the following raw materials in parts by weight: 10 parts of potassium silicate, 2-3 parts of emulsifier, 2.5 parts of nano silicon dioxide, 0.5 parts of triethanolamine, 20 parts of silane coupling agent and 4-5 parts of curing agent; The B component includes the following raw materials in parts by weight: 12 parts of aluminum dihydrogen phosphate, 1.5 parts of magnesium oxide, 10 parts of potassium silicate, 15 parts of light calcium carbonate, 2-5 parts of composite filler, 10-15 parts of epoxy hybrid acrylic emulsion, and 20 parts of water; The silane coupling agent is composed of isobutyltriethoxysilane and long carbon chain silane in a mass ratio of 1-2:1; The long carbon chain silane is a product obtained by a Schiff base reaction between triethoxysilyl butyraldehyde and a long chain alkylamine; The composite filler is a composite product of layered double metal hydroxide and metal organic framework.

2. The concrete protective coating according to claim 1, characterized in that: The mass ratio of component A to component B is 1:

1.

3. The concrete protective coating according to claim 1, characterized in that: The layered double metal hydroxide is magnesium aluminum layered double metal hydroxide, and the metal organic framework is U i O-66-NH 2 .

4. The concrete protective coating according to claim 1, characterized in that: The preparation method of the long carbon chain silane comprises the following steps: Anhydrous ethanol, triethoxysilyl butyraldehyde and long-chain alkylamine are added into a flask, and the temperature is raised to 80° C. under nitrogen protection, and stirred for reaction for 6-8 hours. After the reaction is completed, the anhydrous ethanol is removed by rotary evaporation to obtain the long carbon chain silane.

5. The concrete protective coating according to claim 4, characterized in that: The molar ratio of triethoxysilylbutyraldehyde to long-chain alkylamine is 1-1.1:

1.

6. The concrete protective coating according to claim 1 or 4, characterized in that: The chemical structural formula of the long-chain alkylamine is: R-NH2, wherein R is a C6-C18 straight-chain or branched-chain alkyl.

7. The concrete protective coating according to claim 6, characterized in that: The long-chain alkylamine is at least one of octadecylamine, hexadecylamine and tetradecylamine.

8. The concrete protective coating according to claim 1, characterized in that: The preparation method of the composite filler comprises the following steps: The magnesium aluminum layered double metal hydroxide is added to DMF, ultrasonically dispersed for 30 minutes, and then zirconium tetrachloride and 2-aminoterephthalic acid are added. After stirring for 1 hour, the mixture is transferred to a reactor and reacted at 120° C. for 48 hours. After the reaction is completed, the mixture is naturally cooled to room temperature, filtered, and the filter cake is washed and dried to obtain the composite filler.

9. The concrete protective coating according to claim 7, characterized in that: The usage ratio of magnesium aluminum layered double metal hydroxide, DMF, zirconium tetrachloride and 2-aminoterephthalic acid is 5-7g:3-5L:23.32g:18.12g.

10. A method for preparing a concrete protective coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Stir and mix the potassium silicate, emulsifier, nano-silicon dioxide, triethanolamine, hydrophobic silane and curing agent in the raw materials of component A for 20-30 minutes to obtain component A; S2. The potassium dihydrogen phosphate, magnesium oxide, potassium silicate, light calcium carbonate, composite filler, epoxy hybrid acrylic emulsion and water in the raw materials of component B are stirred and mixed for 0.5-1h to obtain component B.

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