Emulsion-type concrete defoamer and method for preparing the same

Abstract

The present application relates to chemical material technical field, especially provide a kind of emulsion type concrete defoamer and its preparation method, according to mass fraction calculation, including the following components of raw materials are made: 8.5%-23% silicon paste, 3%-8% acetylenic alcohol, 1%-10% emulsifying component, 0.1%-4% thickening component, 0.1%-4% preservative component, the balance is water.The emulsion type concrete defoamer provided by the embodiment of the present application can be used as the main defoaming component by modifying polysiloxane, polyether modified silicone oil and acetylenic alcohol compound, while introducing fluorine element in the defoamer, effectively reducing the surface tension and improving the dispersibility in concrete system, and introducing acetylenic alcohol as the main foam inhibitor component, suitable for concrete system to maintain beneficial small bubbles, defoaming and foam inhibitor component compound speeds up the rupture of bubble membrane, and the defoaming and foam inhibitor performance is good in concrete system, so as to realize the improvement of working performance, and has important practical application value.

Description

Technical Field

[0001] This invention relates to the field of chemical materials technology, and in particular to an emulsion-type concrete defoamer and its preparation method. Background Technology

[0002] With the rapid development of my country's national economy and the large-scale construction of civil engineering projects, my country's construction industry has been driven towards high efficiency, high performance, and sustainability. Concrete, as a crucial civil engineering material, has a profound impact on the advancement of construction technology. The use of various types of water-reducing agents not only affects the workability of concrete in the fresh mixing stage but also improves the structure of hardened concrete at the microscopic and submicroscopic levels. This allows for the modification of concrete through the addition of water-reducing agents to meet requirements for workability, mechanical properties, and durability. Water-reducing agents enable the manufacture and construction of special concretes, such as high-flowability concrete, high-strength concrete, underwater concrete, and shotcrete. Polycarboxylate superplasticizers, due to their unique advantages of customizable molecular structure and properties, are gradually replacing lignin sulfonate superplasticizers, naphthalene-based superplasticizers, and other high-efficiency water-reducing agents, becoming the mainstream water-reducing agent in the market.

[0003] Polycarboxylate superplasticizers are concrete admixtures that reduce the amount of mixing water while maintaining a relatively constant concrete slump, and are widely used in concrete systems. During the use of polycarboxylate superplasticizers, air bubbles are often introduced due to physical mixing in the production equipment, chemical reactions between various additives, and uneven ratios of reagents and water. Furthermore, cement-based material systems introduce a large number of air bubbles during mixing and chemical reactions. Residual air bubbles can affect the hardened strength, durability, and appearance of the material. Therefore, different amounts of defoamers are generally added during concrete mixing to reduce air content and minimize the impact of air bubbles on material properties.

[0004] Because defoamers are specific to certain mixed systems, different defoamers and different dosages will have different defoaming effects on the system. Currently, the commonly available general-purpose polyether emulsion concrete defoamers have good defoaming properties and stability, but they perform worse than single organosilicon defoamers at low dosages, mainly because their surface tension is slightly higher.

[0005] Therefore, in the application of concrete systems, ensuring the workability, strength, and durability of concrete requires the elimination of excess air bubbles, which is a technical problem that those skilled in the art need to solve. Summary of the Invention

[0006] To address the technical problems mentioned in the background section, this invention provides an emulsion-type concrete defoamer, which, based on the total mass of the emulsion-type concrete defoamer as a reference, is made from raw materials comprising the following components according to mass fraction: 8.5%-23% silicone paste, 3%-8% acetylsalicylic acid, 1%-10% emulsifying agent, 0.1%-4% thickening agent, 0.1%-4% preservative agent, and the balance being water;

[0007] The silicone paste is a compound of modified polysiloxane, polyether-modified silicone oil, and hydrophobic particles in a mass ratio of 5-10:3-8:0.5-5.

[0008] Based on the above technical solution, the emulsifying component is further composed of two or more nonionic surfactants and / or anionic surfactants with different HLB levels.

[0009] Based on the above technical solution, the nonionic surfactant is further selected from at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, fatty alcohol polyoxyethylene ether; sorbitan monostearate, sorbitan monooleate, sorbitan tristearate, sorbitan trioleate; polyoxyethylene sorbitan ether stearate, sorbitan monooleate polyoxyethylene ether, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan trioleate, and castor oil polyoxyethylene ether.

[0010] The alkylphenol polyoxyethylene ether includes at least one of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, dodecylphenol polyoxyethylene ether, and dinonylphenol polyoxyethylene ether.

[0011] The fatty acid polyoxyethylene ether includes at least one of lauric acid polyoxyethylene ether, oleic acid polyoxyethylene ether, palmitic acid polyoxyethylene ether, and stearic acid polyoxyethylene ether;

[0012] The anionic surfactant includes one of carboxylates, sulfates, sulfonates, and phosphates, specifically selected from at least one of sodium dodecyl polyoxyethylene ether sulfate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, sodium hexadecyl sulfonate, sodium hexadecylbenzene sulfonate, and sodium dodecyl diphenyl ether disulfonate.

[0013] Based on the above technical solution, the thickening component is further composed of one or more of the following: vinylon gum, xanthan gum, polysaccharide, carbomer, xanthan gum, guar gum, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, sodium carboxymethyl cellulose, polyacrylate, polyacrylamide, polyacrylic acid, polyacrylamide, polyacrylate, sodium polyacrylate, polyoxyethylene, polyvinylpyrrolidone, propylene glycol alginate, sodium starch phosphate, sodium alginate, casein, organobentonite, and chitosan solution.

[0014] Based on the above technical solution, the preservative component is further described as an isothiazolinone series preservative component, preferably one or more of 2-methyl-4-isothiazolin-3-one, 2-methyl-5-chloro-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, and 2-methyl-5-chloro-4-isothiazolin-3-one.

[0015] Based on the above technical solution, furthermore, the hydrophobic particles are at least one of nano-silica, methyl MQ type silicone resin, alum, magnesium salt of fatty acid, calcium salt of fatty acid, aluminum salt of fatty acid, zinc salt of fatty acid, and particulate polyisobutylene.

[0016] This invention also provides a method for preparing the above-mentioned emulsion-type concrete defoamer, comprising the following steps:

[0017] Preparation of modified polysiloxane: The reactor temperature is controlled at 100-130℃. Epoxy fluorosilicone oil, hydroxyl-containing polyether, and catalyst are added sequentially to the reactor. Nitrogen gas is introduced, and the mixture is stirred continuously for 2-4 hours. The modified polysiloxane is obtained by separation and purification. The mass ratio of the epoxy fluorosilicone oil, hydroxyl-containing polyether, and catalyst is 50-200:40-180:0.5-1.

[0018] Preparation of silicone paste: Control the reactor temperature at 110-150℃, add modified polysiloxane, polyether-modified silicone oil and hydrophobic particles to the reactor, stir continuously for 2-5 hours, and cool to room temperature to obtain silicone paste.

[0019] Preparation of emulsion-type concrete defoamer: Control the reactor temperature at 60-90℃, mix silicone paste, alkynol and emulsifying components, stir at 500-1000 r / min for 0.5-1.5 h, slowly add 10%-20% water, increase the speed to 1000-2000 r / min and stir for 0.5-1.5 h, slowly add the remaining water, and simultaneously add thickening and anti-corrosion components, increase the speed to 1500-3000 r / min and stir for 0.5-1.5 h, cool to room temperature to obtain the emulsion-type concrete defoamer.

[0020] Based on the above technical solution, the epoxy fluorosilicone oil further has the following structural formula:

[0021]

[0022] The structural formula of the hydroxyl-containing polyether is:

[0023]

[0024] The modified polysiloxane has the following structural formula:

[0025]

[0026] Wherein, a is 0–45, b is 5–60, c is 5–60, m is 10–50, n is 10–50, and R1 is at least one of -SiO(CH3)3 or -CH2-CH2-CH2-O-CH2-C3H3O.

[0027] Based on the above technical solution, the polyether-modified silicone oil further has the following structural formula:

[0028]

[0029] Where d values ​​range from 1 to 60, e values ​​range from 1 to 10, f values ​​range from 1 to 60, p values ​​range from 10 to 35, and q values ​​range from 10 to 40;

[0030] R2 is either -H or -CH3.

[0031] Specifically, the polyether-modified silicone oil is prepared by hydrosilylation reaction of end-hydrogen-containing silicone oil or side-hydrogen-containing silicone oil and vinyl polyether. The specific preparation method is known to those skilled in the art.

[0032] Based on the above technical solution, the structural formula of the alkynol is further shown below:

[0033]

[0034] R3 is either -H or -CH3;

[0035] R4 is one of -H, -CH3, or -CH2CH3;

[0036] R5 is one of -H, -CH3, -CH2CH3, -CH(CH2)2, -CH2CH2CH3, -CH2CH(CH2)2, -CH2CH2CH2CH3, -CH2CH2CH(CH2)2, -CH2CH2CH2CH2CH3, -CH2CH2CH2CH(CH2)2.

[0037] Based on the above technical solution, the catalyst is further selected from at least one of triethylenediamine, N-alkylmorpholine, bis(2-methyloxyethyl), ethylenediamine, triethylamine, m-phenylenediamine, and p-phenylenediamine.

[0038] The emulsion-type concrete defoamer provided by this invention has the following technical effects:

[0039] The emulsion-type concrete defoamer provided by this invention uses modified polysiloxane with fluorinated groups on its side chains. By combining it with polyether-modified silicone oil and hydrophobic particles to form silicone paste as the main defoaming component, it effectively reduces surface tension and improves defoaming efficiency. Furthermore, the introduction of hydrophilic polyether segments into the modified polysiloxane and polyether-modified silicone oil effectively improves the dispersibility of the defoaming active substances in concrete, making it easier for them to exert their defoaming and foam-suppressing effects in the concrete system.

[0040] Furthermore, this invention introduces alkynol as the main defoaming component, which is suitable for maintaining beneficial small air bubbles in concrete systems and avoiding the formation of harmful large air bubbles, thus meeting the requirements of actual concrete work. It also increases the spreading coefficient and lowers the entry barrier by combining defoaming and defoaming components, making it easier to form an unstable film on the surface of the foam, thereby accelerating the rupture of the foam. At the same time, it is beneficial to use it in combination with polycarboxylate superplasticizer.

[0041] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description and claims. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] In the emulsion-type concrete defoamer technical solution provided by this invention, the epoxy fluorosilicone oil has the following structural formula:

[0044]

[0045] The structural formula of the hydroxyl-containing polyether is:

[0046]

[0047] The modified polysiloxane has the following structural formula:

[0048]

[0049] The value of a is 0-45, the value of b is 5-60, the value of c is 5-60, the value of m is 10-50, the value of n is 10-50, and R1 is at least one of -SiO(CH3)3 or -CH2-CH2-CH2-O-CH2-C3H3O.

[0050] The polyether-modified silicone oil has the following structural formula:

[0051]

[0052] Where d values ​​range from 1 to 60, e values ​​range from 1 to 10, f values ​​range from 1 to 60, p values ​​range from 10 to 35, and q values ​​range from 10 to 40;

[0053] R2 is one of -H or -CH3. The polyether-modified silicone oil is prepared by hydrosilylation reaction of terminal hydrogen-containing silicone oil or side-containing hydrogen-containing silicone oil and vinyl polyether; the preparation method is well known in the industry.

[0054] The structural formula of the alkynol is shown below:

[0055]

[0056] R3 is either -H or -CH3;

[0057] R4 is one of -H, -CH3, or -CH2CH3;

[0058] R5 is one of -H, -CH3, -CH2CH3, -CH(CH2)2, -CH2CH2CH3, -CH2CH(CH2)2, -CH2CH2CH2CH3, -CH2CH2CH(CH2)2, -CH2CH2CH2CH2CH3, -CH2CH2CH2CH(CH2)2.

[0059] Therefore, the following examples are provided:

[0060] Table 1

[0061]

[0062]

[0063] Specifically, the present invention provides the following preparation methods for embodiments and comparative examples:

[0064] Example 1

[0065] This embodiment provides a method for preparing modified polysiloxane A1: The reactor temperature is controlled at 110℃, and epoxy fluorosilicone oil, hydroxyl-containing polyether, and triethylenediamine are added sequentially to the reactor in a mass ratio of 80:105:0.8. Nitrogen gas is introduced, and the mixture is stirred continuously for 4 hours. The modified polysiloxane A1 is then obtained through separation and purification.

[0066] Example 2

[0067] This embodiment provides another method for preparing modified polysiloxane A2: The reactor temperature is controlled at 120°C. Epoxy fluorosilicone oil, hydroxyl-containing polyether, and triethylenediamine are added sequentially to the reactor in a mass ratio of 90:140:1.0. Nitrogen gas is introduced, and the mixture is stirred continuously for 4 hours. Modified polysiloxane A2 is then obtained through separation and purification.

[0068] Example 3

[0069] This embodiment provides a method for preparing an emulsion-type concrete defoamer: the reactor temperature is controlled at 120°C, and modified polysiloxane A1, polyether modified silicone oil, nano silica, and methyl MQ type silicone resin are added to the reactor in a mass ratio of 40:22:3:2.5. The mixture is stirred continuously for 2.5 hours and then cooled to room temperature to obtain silicone paste.

[0070] Controlling the reactor temperature at 70℃, 17 parts of silicone paste, 5 parts of alkynol, and 6 parts of emulsifying agent (sorbitan monostearate (Span-60): polyoxyethylene sorbitan ether stearate (Tween-60) = 1.6:1) were mixed according to the mass ratio and stirred at 1000 r / min for 1 h. 14 parts of water were slowly added, and the stirring speed was increased to 1500 r / min for 1 h. The remaining water was slowly added, along with 1 part of thickening agent (sodium carboxymethyl cellulose) and 0.1 part of preservative agent (2-methyl-4-isothiazolin-3-one). The stirring speed was increased to 3000 r / min for 1.5 h. The mixture was then cooled to room temperature to obtain an emulsion-type concrete defoamer.

[0071] Example 4

[0072] This embodiment provides a method for preparing an emulsion-type concrete defoamer: the reactor temperature is controlled at 130°C, and modified polysiloxane A1, polyether modified silicone oil, nano silica, and methyl MQ type silicone resin are added to the reactor in a mass ratio of 42:18:2:3. The mixture is stirred continuously for 3 hours and then cooled to room temperature to obtain silicone paste.

[0073] Controlling the reactor temperature at 75℃, 16 parts of silicone paste, 6 parts of alkynol, and 5.5 parts of emulsifying agent (sorbitan monostearate (Span-60): polyoxyethylene sorbitan ether stearate (Tween-60) = 1.4:1) were mixed according to the mass ratio and stirred at 1000 r / min for 1 h. 12 parts of water were slowly added, and the stirring speed was increased to 1800 r / min for 0.5 h. The remaining water was slowly added, along with 0.7 parts of thickening agent (sodium carboxymethyl cellulose) and 0.1 parts of preservative agent (2-methyl-4-isothiazolin-3-one). The stirring speed was increased to 3000 r / min for 1.5 h. The mixture was then cooled to room temperature to obtain an emulsion-type concrete defoamer.

[0074] Example 5

[0075] This embodiment provides a method for preparing an emulsion-type concrete defoamer: the reactor temperature is controlled at 130°C, and modified polysiloxane A2, polyether modified silicone oil, nano silica, and alum are added to the reactor in a mass ratio of 46:16:4:2.5. The mixture is stirred continuously for 3 hours and then cooled to room temperature to obtain silicone paste.

[0076] Controlling the reactor temperature at 70℃, 15 parts of silicone paste, 7 parts of alkynol, and 6 parts of emulsifying agent (sorbitan monooleate (Span-80): sorbitan monooleate polyoxyethylene ether (Tween-80) = 2:1) were mixed according to the mass ratio. The mixture was stirred at 800 r / min for 0.5 h, and 15 parts of water were slowly added. The stirring speed was increased to 1500 r / min and stirred for 1 h. The remaining water was slowly added, along with 1.0 part of thickening agent (polyacrylate) and 0.1 part of anti-corrosion agent (2-methyl-4-isothiazolin-3-one). The stirring speed was increased to 3000 r / min and stirred for 2 h. The mixture was then cooled to room temperature to obtain an emulsion-type concrete defoamer.

[0077] Example 6

[0078] This embodiment provides a method for preparing an emulsion-type concrete defoamer: the reactor temperature is controlled at 125°C, and modified polysiloxane A2, polyether modified silicone oil, nano silica, and alum are added to the reactor in a mass ratio of 49:15:5:4. The mixture is stirred continuously for 3 hours and then cooled to room temperature to obtain silicone paste.

[0079] Controlling the reactor temperature at 80℃, 18 parts of silicone paste, 8 parts of alkynol, and 7 parts of emulsifying agent (sorbitan monooleate (Span-80): sorbitan monooleate polyoxyethylene ether (Tween-80) = 1.7:1) were mixed according to the mass ratio. The mixture was stirred at 1000 r / min for 0.5 h, and 14 parts of water were slowly added. The stirring speed was increased to 2000 r / min and stirred for 1 h. The remaining water was slowly added, along with 1.4 parts of thickening agent (polyacrylate) and 0.1 parts of anti-corrosion agent (2-methyl-4-isothiazolin-3-one). The stirring speed was increased to 3000 r / min and stirred for 1.5 h. The mixture was then cooled to room temperature to obtain an emulsion-type concrete defoamer.

[0080] The parameters provided in this embodiment are for specific reference in implementing this embodiment and are not intended to limit the concept of the present invention. Those skilled in the art can make corresponding changes to the parameters according to the inventive concept of the present invention to achieve the corresponding technical effects of the present invention.

[0081] The present invention also provides the following comparative examples:

[0082] Comparative Example 1:

[0083] Polyether-modified silicone defoamer, KZJ-X12 from Kezhijie New Materials Group Co., Ltd.;

[0084] Comparative Example 2:

[0085] Based on Example 3, an equal amount of dimethyl silicone oil was used to replace the modified polysiloxane A1, and the other conditions remained the same as in Example 3, to obtain the defoamer of Comparative Example 2.

[0086] Comparative Example 3:

[0087] Based on Example 5, an equal amount of dimethyl silicone oil was used to replace the modified polysiloxane A2, and the other conditions remained the same as in Example 5, to obtain the defoamer of Comparative Example 3.

[0088] To further illustrate the performance of the emulsion-type concrete defoamer provided by this invention, the above-mentioned examples and comparative examples were tested for cement concrete workability according to GB 8076-2008 "Concrete Admixtures" standard. The results were verified through concrete experiments with different mix proportions. Using the same compounding conditions (water-reducing agent: air-entraining agent: water = 50:1:199), the defoamer dosage was 0.05% of the concrete binder weight. The concrete mix proportions are shown in Table 2, and the concrete performance test results are shown in Table 3.

[0089] Table 2 Concrete Mix Proportions (Unit: kg / m³) 3

[0090] conch 2.9 0.4 0.3 8.8 9.3 1.4

[0091] Table 3. Air Content Test of Concrete

[0092]

[0093] The experimental results in Table 3 show that, compared with Comparative Example 1, Examples 3-6 have significantly lower air content at 0h and 3h under the same dosage, better workability, and higher 28d compressive strength, indicating that they better meet the requirements of concrete workability. Compared with the examples, Comparative Examples 2 and 3 have weaker defoaming and foam-suppressing performance, indicating that the introduced modified polysiloxane effectively improves the defoaming and foam-suppressing performance of the prepared organosilicon defoamer.

[0094] The emulsion-type concrete defoamer provided in this invention uses modified polysiloxane, polyether-modified silicone oil, and alkynyl alcohol as the main defoaming and foam-suppressing components. By introducing fluorine into the defoamer and grafting polyether segments, the surface tension is effectively reduced and the dispersibility in the concrete system is improved. The introduction of alkynyl alcohol as the main foam-suppressing component is suitable for maintaining beneficial small air bubbles in the concrete system. The combination of defoaming and foam-suppressing components accelerates the rupture of the bubble film, resulting in good defoaming and foam-suppressing performance in the concrete system, thereby improving the workability.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An emulsion-type concrete defoamer, characterized in that, Based on the total mass of the emulsion-type concrete defoamer as a reference, and calculated according to mass fraction, it is made from the following raw materials: 8.5%-23% silicone paste, 3%-8% acetylsol, 1%-10% emulsifying component, 0.1%-4% thickening component, 0.1%-4% anti-corrosion component, and the balance being water; The silicone paste is a compound of modified polysiloxane, polyether-modified silicone oil, and hydrophobic particles in a mass ratio of 5-10:3-8:0.5-5. The modified polysiloxane is prepared by the following steps: controlling the reactor temperature at 100-130℃, adding epoxy fluorosilicone oil, hydroxyl-containing polyether and catalyst to the reactor in sequence, introducing nitrogen gas, stirring continuously for 2-4 hours, and separating and purifying to obtain the modified polysiloxane. The mass ratio of the epoxy fluorosilicone oil, the hydroxyl-containing polyether, and the catalyst is 50-200 : 40-180 : 0.5-1. The catalyst is at least one selected from the following: triethylenediamine, N-alkylmorpholine, ethylenediamine, triethylamine, m-phenylenediamine, and p-phenylenediamine; The epoxy fluorosilicone oil has the following structural formula: ； The structural formula of the hydroxyl-containing polyether is: ； The modified polysiloxane has the following structural formula: ； Wherein, a is 0–45, b is 5–60, c is 5–60, m is 10–50, n is 10–50, and R1 is at least one of -SiO(CH3)3 or -CH2-CH2-CH2-O-CH2-C3H3O; The polyether-modified silicone oil has the following structural formula: ;or ； Where d values ​​range from 1 to 60, e values ​​range from 1 to 10, f values ​​range from 1 to 60, p values ​​range from 10 to 35, and q values ​​range from 10 to 40; R2 is either -H or -CH3.

2. The emulsion-type concrete defoamer according to claim 1, characterized in that: The emulsifying component is a combination of two or more nonionic surfactants and / or anionic surfactants with different HLB levels.

3. The emulsion-type concrete defoamer according to claim 2, characterized in that: The nonionic surfactant is selected from at least one of alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ether, fatty alcohol polyoxyethylene ether, sorbitan monostearate, sorbitan monooleate, sorbitan tristearate, sorbitan trioleate; polyoxyethylene sorbitan ether stearate, sorbitan monooleate polyoxyethylene ether, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan trioleate, and castor oil polyoxyethylene ether. The alkylphenol polyoxyethylene ether includes at least one of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, dodecylphenol polyoxyethylene ether, and dinonylphenol polyoxyethylene ether. The fatty acid polyoxyethylene ether includes at least one of lauric acid polyoxyethylene ether, oleic acid polyoxyethylene ether, palmitic acid polyoxyethylene ether, and stearic acid polyoxyethylene ether; The anionic surfactant includes one of carboxylates, sulfates, sulfonates, and phosphates; the anionic surfactant is selected from at least one of sodium dodecyl polyoxyethylene ether sulfate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, sodium hexadecyl sulfonate, sodium hexadecylbenzene sulfonate, and sodium dodecyl diphenyl ether disulfonate.

4. The emulsion-type concrete defoamer according to claim 1, characterized in that: The thickening component is composed of one or more of the following: vinylon gum, xanthan gum, polysaccharide, carbomer, xanthan gum, guar gum, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, sodium carboxymethyl cellulose, polyacrylate, polyacrylamide, polyacrylic acid, sodium polyacrylate, polyoxyethylene, polyvinylpyrrolidone, propylene glycol alginate, sodium starch phosphate, sodium alginate, casein, organobentonite, and chitosan solution.

5. The emulsion-type concrete defoamer according to claim 1, characterized in that: The preservative component is one or more of 2-methyl-4-isothiazolin-3-one, 2-methyl-5-chloro-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, and 2-methyl-5-chloro-4-isothiazolin-3-one.

6. The emulsion-type concrete defoamer according to claim 1, characterized in that: The hydrophobic particles are at least one of nano-silica, methyl MQ type silicone resin, alum, magnesium salt of fatty acid, calcium salt of fatty acid, aluminum salt of fatty acid, zinc salt of fatty acid, and particulate polyisobutylene.

7. A method for preparing an emulsion-type concrete defoamer according to any one of claims 1-6, characterized in that, Includes the following steps: Preparation of modified polysiloxane: The reactor temperature is controlled at 100-130℃. Epoxy fluorosilicone oil, hydroxyl-containing polyether, and catalyst are added sequentially to the reactor. Nitrogen gas is introduced, and the mixture is stirred continuously for 2-4 hours. The modified polysiloxane is obtained by separation and purification. The mass ratio of the epoxy fluorosilicone oil, hydroxyl-containing polyether, and catalyst is 50-200 : 40-180 : 0.5-1. Preparation of silicone paste: Control the reactor temperature at 110-150℃, add modified polysiloxane, polyether-modified silicone oil and hydrophobic particles to the reactor, stir continuously for 2-5 hours, and cool to room temperature to obtain silicone paste. Preparation of emulsion-type concrete defoamer: Control the reactor temperature at 60-90℃, mix silicone paste, alkynol and emulsifying components, stir at 500-1000 r / min for 0.5-1.5 h, slowly add 10%-20% water, increase the speed to 1000-2000 r / min and stir for 0.5-1.5 h, slowly add the remaining water, and simultaneously add thickening and anti-corrosion components, increase the speed to 1500-3000 r / min and stir for 0.5-1.5 h, cool to room temperature to obtain the emulsion-type concrete defoamer.

8. The method for preparing the emulsion-type concrete defoamer according to claim 7, characterized in that: The structural formula of the alkynol is shown below: ； R3 is either -H or -CH3; R4 is one of -H, -CH3, or -CH2CH3; R5 is one of -H, -CH3, -CH2CH3, -CH(CH2)2, -CH2CH2CH3, -CH2CH(CH2)2, -CH2CH2CH2CH3, -CH2CH2CH(CH2)2, -CH2CH2CH2CH2CH3, -CH2CH2CH2CH(CH2)2.

9. The method for preparing the emulsion-type concrete defoamer according to claim 7, characterized in that: The catalyst is at least one of triethylenediamine, N-alkylmorpholine, ethylenediamine, triethylamine, m-phenylenediamine, and p-phenylenediamine.

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