Self-cleaning high-performance release agent for non-vibrating concrete and preparation method thereof

Abstract

The application discloses a kind of self-cleaning high-performance release agent for non-vibrating concrete and a preparation method thereof, and belongs to the technical field of building material chemical additives.The self-cleaning high-performance release agent for non-vibrating concrete comprises the following raw materials in mass fraction: hydrophobic modifier 20-40 parts, nano-porous material 10-20 parts, bubble barrier 50-100 parts, base oil 400-550 parts, emulsifier 100-150 parts, defoamer 2-10 parts, and water 130-418 parts.The self-cleaning high-performance release agent for non-vibrating concrete can optimize the appearance quality of concrete (mainly including surface smoothness, air bubbles, and color difference) under difficult construction conditions of concrete formwork cleaning and vibration, and make the formwork free of cleaning release agent.

Description

Technical Field

[0001] This invention belongs to the field of chemical additives for building materials, and particularly relates to a high-performance release agent for self-cleaning, vibration-free concrete and its preparation method. Background Technology

[0002] With the rapid development of the construction industry, in addition to meeting basic workability, mechanical properties, and durability requirements, higher demands are being placed on the surface aesthetics of concrete. The appearance of concrete in piers, bridges, and secondary linings has become a key focus. While the formwork for piers and bridges can be surface-treated by grinding, and the plastic stage of concrete facilitates vibration compaction, and surface air bubbles can be eliminated by significantly extending the vibration time, this treatment damages the coating on the formwork surface, leading to oxidation and the formation of black iron oxide (Fe3O4) substances inside. This results in uneven black spots on the concrete surface after demolding. Prolonged vibration to remove air bubbles can also damage the underlying concrete aggregate, harming the concrete structure. With the significant increase in tunnel engineering, the demand for secondary lining concrete is growing. However, due to the special nature of its construction location, the current formwork treatment (which cannot be ground) and the limited vibration methods (only attached vibration) cannot meet the higher aesthetic requirements through conventional means (cleaning the formwork and strengthening vibration). Furthermore, the coating on the formwork surface is damaged after the formwork is processed, and the interior is oxidized to produce black iron oxide (Fe3O4), resulting in uneven black spots on the concrete surface after demolding. Prolonged vibration to remove air bubbles can also damage the concrete structure by affecting the lower layers of aggregate. Regarding the problems with the No. 2 Village concrete, formwork cleaning and vibration methods are limited (due to tunnel construction techniques). Currently, there is no release agent on the market that can simultaneously solve color difference, air bubbles, and achieve zero adhesion to the formwork (allowing for direct reuse without cleaning). Therefore, there is an urgent need in this field for a self-cleaning, vibration-free, high-performance release agent. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes a high-performance release agent for self-cleaning, vibration-free concrete and its preparation method. The high-performance release agent of this invention is a release agent that can optimize the appearance quality (mainly including surface smoothness, air bubbles, and color difference) of concrete under construction conditions where concrete formwork is difficult to clean and vibration is difficult.

[0004] To achieve the above objectives, the present invention provides a high-performance release agent for self-cleaning, vibration-free concrete, comprising the following raw materials by weight: 20-40 parts of hydrophobic modifier, 10-20 parts of nanoporous material, 50-100 parts of bubble barrier agent, 400-550 parts of base oil, 100-150 parts of emulsifier, 2-10 parts of defoamer, and 130-418 parts of water.

[0005] Furthermore, the hydrophobic modifier is selected from one of heptadecafluorodecyltrimethoxysilane, perfluorooctyltriethoxysilane, tridecafluorooctyltrimethoxysilane, and hexadecyltrimethoxysilane.

[0006] Furthermore, the nanoporous material is selected from nano-silica with a particle size of 100-300 nm.

[0007] Furthermore, the bubble barrier agent is selected from one of oleic acid, linoleic acid, linolenic acid, ricinoleic acid, isostearic acid, and neodecanoic acid.

[0008] Furthermore, the base oil is selected from one of soybean oil, rapeseed oil, and corn oil.

[0009] Furthermore, the defoamer is selected from one of acetylenic diol defoamers and organosilicon defoamers.

[0010] Furthermore, the silicone defoamer includes a polyether-modified silicone defoamer.

[0011] Furthermore, the emulsifier is selected from three of the following: polyoxyethylene hydrogenated castor oil CO-40, triglyceride monooleate, decaglyceride monooleate, dodecylphenol polyoxyethylene ether, sorbitan monooleate, and dehydrated sorbitol fatty acid ester.

[0012] The present invention also provides a method for preparing the above-mentioned high-performance release agent for self-cleaning, vibration-free concrete, comprising the following steps:

[0013] Accurately weigh each raw material according to the mass fraction, mix the hydrophobic modifier and nanoporous material, stir for the first time, heat to 20-30℃, keep warm, centrifuge, add base oil, bubble blocker, emulsifier and defoamer, stir for the second time, heat to 30-40℃, add water, keep warm, and obtain an oil-in-water emulsion, which is the self-cleaning non-vibrating concrete high-performance release agent.

[0014] Furthermore, in the preparation method of the high-performance release agent for self-cleaning, vibration-free concrete, the rotation speed of the first stirring is 500 rpm;

[0015] And / or, the centrifugation speed is 10000 rpm and the time is 10 min;

[0016] And / or, the second stirring speed is 1000-1500 rpm.

[0017] Furthermore, in the preparation method of the high-performance release agent for self-cleaning, vibration-free concrete, the two heat preservation times are both 30 minutes.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects:

[0019] In this invention, the nanoporous material loaded with a hydrophobic modifier exhibits strong hydrophobic properties. During emulsification with base oil and a bubble barrier, free water is difficult to penetrate the interior of the porous material, and the hydrophobic modifier does not undergo hydrolysis. The nanoporous material provides hydrolysis protection for the hydrophobic modifier. The high-performance release agent for self-cleaning, vibration-free concrete is an oil-in-water emulsion. When this emulsion is applied to the surface of the template, the oil film formed after the emulsion breaks down contains four components: base oil, nanoporous material loaded with a hydrophobic modifier, bubble barrier, and defoamer. When the cement paste comes into contact with the oil film, due to the highly alkaline environment of the cement paste, the nanoporous material reacts rapidly with the alkali to release the hydrophobic modifier. The siloxane in the hydrophobic modifier rapidly hydrolyzes to form silanol groups, which then form covalent bonds with the silicate components in the cement, thereby forming a superhydrophobic layer on the surface of the cement paste. This hydrophobic layer possesses properties that are neither hydrophilic nor oleophilic. In alkaline systems, bubble-blocking agents react with calcium to form polyalkyl calcium carboxylate salts. These salts possess hydrophobicity at one end and hydrophilicity at the other, allowing them to form only at the oil-water interface (i.e., the interface between the oil film and the cement paste). Therefore, these polyalkyl calcium carboxylate salts effectively block air bubbles on the cement paste surface. Due to the limited amount of polyalkyl calcium carboxylate salts produced, their blocking effect on pinhole-sized bubbles is more pronounced, resulting in better performance when used in combination with defoamers. Because the hydrophobic modifier possesses unique properties of being neither hydrophilic nor oleophilic, a sandwich-structured film is ultimately formed on the cement paste surface. From the inside out, this film consists of the polyalkyl calcium carboxylate salt, the base oil, and the hydrophobic modifier. This structure not only blocks small air bubbles on the cement paste surface but also provides a self-cleaning function, ensuring that the template surface in contact with the concrete interface is completely free of adhering paste film. Ultimately, this achieves self-cleaning, vibration-free concrete with virtually no bubble defects in appearance. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 The condition of surface laitance on the template after using the release agent of Examples 1-6;

[0022] Figure 2 The appearance of the specimens after demolding in Examples 1-6;

[0023] Figure 3 The surface laitance of the template after using release agents from Comparative Examples 1 to 5;

[0024] Figure 4 The appearance of the specimens after demolding in Comparative Examples 1-5. Detailed Implementation

[0025] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0026] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0027] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0028] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0029] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0030] The present invention provides a high-performance release agent for self-cleaning, vibration-free concrete, comprising the following raw materials by weight: 20-40 parts hydrophobic modifier, 10-20 parts nanoporous material, 50-100 parts bubble barrier, 400-550 parts base oil, 100-150 parts emulsifier, 2-10 parts defoamer, and 130-418 parts water.

[0031] The self-cleaning, vibration-free, high-performance release agent for concrete of the present invention is a release agent that can optimize the appearance quality (mainly including surface smoothness, air bubbles, and color difference) of concrete under conditions where concrete formwork is difficult to clean and vibration is difficult to apply.

[0032] In some preferred embodiments of the present invention, the hydrophobic modifier is selected from one of heptadecafluorodecyltrimethoxysilane, perfluorooctyltriethoxysilane, tridecafluorooctyltrimethoxysilane, and hexadecyltrimethoxysilane. The silanol groups formed by the rapid hydrolysis of the siloxane in the above-mentioned hydrophobic modifier can form covalent bonds of silicon-oxygen with the silicate components in cement, thereby forming a superhydrophobic layer on the surface of the cement paste. This hydrophobic layer has the properties of being neither hydrophilic nor oleophilic.

[0033] In some preferred embodiments of the present invention, the nanoporous material is selected from nano-silica with a particle size of 100-300 nm. Nano-silica particles can fill the micropores in the cement matrix, reducing surface defects and making the concrete denser and smoother. Nano-silica also significantly reduces Cl- by generating CSH gel and a three-dimensional network structure. - It also improves water permeability, reducing surface spalling and cracking caused by corrosion or freeze-thaw cycles. Nano-silica can also reduce the risk of macroscopic cracking and prevent noticeable cracks from appearing on concrete surfaces by optimizing the interfacial transition zone (ITZ) structure.

[0034] In some preferred embodiments of the present invention, the bubble barrier is selected from oleic acid, linoleic acid, linolenic acid, castor oil, isostearic acid, and neodecanoic acid. Oleic acid, linoleic acid, and linolenic acid are all alkyl groups containing 18 carbons, and their hydrophobic tails can be inserted into the bubble film layer, forming a stable interfacial film through close arrangement via van der Waals forces. The polyunsaturated structures of linoleic acid and linolenic acid produce rigid bending of the molecular chains, increasing the mechanical strength of the bubble film and inhibiting bubble coalescence and rupture. The methyl branches of isostearic acid and the short branches of neodecanoic acid reduce molecular symmetry, improving solubility in cement paste and preventing barrier failure due to crystallization. The hydroxyl groups (-OH) of castor oil provide polar anchoring sites, enhancing adsorption to cement particles and preventing hydrolysis of the bubble barrier in alkaline environments. The α-branched structure of neodecanoic acid shields the ester groups, reducing the interaction with Ca in cement. 2+ The saponification reaction of ricinoleic acid (traditional stearic acid saponification rate can reach 70%, neodecanoic acid only 15%); the hydroxyl groups of ricinoleic acid react with Ca... 2+ They form chelates, further stabilizing the interfacial film; the low freezing point of linolenic acid (-11℃) allows it to effectively block air bubbles during low-temperature application, significantly widening the application temperature range compared to stearic acid (freezing point 69℃). The p-values ​​of the above fatty acids... KaThe pH value (approximately 4.5-5.5) ensures that it remains deprotonated in the highly alkaline environment of concrete (pH>12.5), inhibiting bubble aggregation through electrostatic repulsion. Oleic acids, linoleic acid, and linolenic acid can be extracted from vegetable oils such as olive oil, peanut oil, and flaxseed oil; ricinoleic acid can be extracted from castor oil; isostearic acid and neodecanoic acid can also be obtained through chemical synthesis or extraction from natural oils. The raw material sources for these fatty acids are relatively abundant, meeting the needs of large-scale production of high-performance release agents for self-cleaning, non-vibrating concrete.

[0035] In some preferred embodiments of the present invention, the base oil is selected from soybean oil, rapeseed oil, and corn oil. These base oils are rich in unsaturated double bonds, which endow the oil molecules with excellent surface activity and can significantly reduce the liquid-gas interfacial tension. Base oils such as soybean oil, rapeseed oil, and corn oil contain various fatty acids, such as linoleic acid and oleic acid. These fatty acids can give the concrete release agent good lubricity, allowing it to spread effectively on the surface of the concrete mold panel, playing a role in isolation and defoaming, thereby reducing the formation of bubbles and improving the smoothness of the concrete surface. Moreover, these base oils have a moderate viscosity, which can form a uniform film on the concrete surface. The viscosity is neither too high, affecting the workability, nor too low, failing to effectively cover the concrete surface, thus better fulfilling its isolation and lubrication functions. Soybean oil, rapeseed oil, and corn oil, among other base oils, are derived from plants and are renewable resources. Compared to non-renewable resources like mineral oil, they offer better environmental friendliness and sustainability, aligning with modern society's demands for green and environmentally friendly practices. These base oils can be decomposed by microorganisms in the natural environment, resulting in less pollution and avoiding the long-term residues and ecosystem hazards associated with synthetic chemicals. Therefore, their application in high-performance release agents for self-cleaning, non-vibrating concrete is more in line with environmental protection principles. Soybean oil, rapeseed oil, and corn oil, with their unique molecular structure, environmental friendliness, and multifunctional synergistic effects, have become ideal base oil choices for concrete release agents. They not only effectively block air bubbles and optimize surface aesthetics but also significantly improve the overall performance of concrete through additional functions such as lubrication and self-healing, while simultaneously meeting the industrial demands for sustainable development. In this invention, the nanoporous material loaded with hydrophobic modifier has strong hydrophobic properties. During the emulsification process with base oil and bubble barrier agent, free water has difficulty entering the interior of the porous material. The hydrophobic modifier will not undergo hydrolysis reaction, preventing premature hydrolysis and cross-linking of the hydrophobic modifier, which would damage the stability of the emulsion. Furthermore, it cannot achieve the formation of covalent bonds between silanol groups and silicate components in cement, thus losing the function of forming a superhydrophobic layer on the surface of cement paste and ultimately losing the effect of no template and no cleaning required.

[0036] In some preferred embodiments of the present invention, the defoamer is selected from one of acetylenic diol defoamers and silicone defoamers, wherein the silicone defoamer includes polyether-modified silicone defoamers. For example, the acetylenic diol defoamer is Evonik 740, the polyether-modified silicone defoamer is Toho DF210, and the silicone defoamer is BASF 1300.

[0037] In some preferred embodiments of the present invention, the emulsifier is selected from three of the following: polyoxyethylene hydrogenated castor oil CO-40, triglyceride monooleate, decaglyceride monooleate, dodecylphenol polyoxyethylene ether, sorbitan monooleate, and dehydrated sorbitol fatty acid ester. These emulsifiers, through their unique chemical structure, emulsifying and dispersing capabilities, and multi-scale durability enhancement mechanisms, not only significantly improve the surface aesthetic quality of concrete but also construct a long-lasting protective system at the microstructural level. Simultaneously, these emulsifiers also possess environmental advantages, aligning with the development trend of green building materials.

[0038] The present invention also provides a method for preparing the above-mentioned high-performance release agent for self-cleaning, vibration-free concrete, comprising the following steps:

[0039] Accurately weigh each raw material according to the mass fraction, mix the hydrophobic modifier and nanoporous material, stir for the first time, heat to 20-30℃, keep warm, centrifuge, add base oil, bubble blocker, emulsifier and defoamer, stir for the second time, heat to 30-40℃, add water, keep warm, and obtain an oil-in-water emulsion, which is a high-performance release agent for self-cleaning, vibration-free concrete.

[0040] In some preferred embodiments of the present invention, the stirring speed for the first stirring is 500 rpm;

[0041] And / or, the centrifugation speed is 10000 rpm and the time is 10 min;

[0042] And / or, the second stirring speed is 1000-1500 rpm.

[0043] In some preferred embodiments of the present invention, the duration of each heat preservation is 30 minutes.

[0044] The high-performance release agent provided in this invention can be used to beautify self-cleaning, vibration-free concrete. Under conditions where concrete formwork is difficult to clean and vibration is difficult to apply, it optimizes the appearance quality of concrete (mainly including surface smoothness, air bubbles, and color difference).

[0045] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0046] Unless otherwise specified, "parts" in the embodiments and comparative examples of this invention refer to parts by mass.

[0047] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0048] The technical solution of the present invention will be further illustrated by the following embodiments.

[0049] Example 1

[0050] This embodiment provides a method for preparing a high-performance release agent for self-cleaning, vibration-free concrete, the steps of which are as follows:

[0051] Add 20 parts of heptadecafluorodecyltrimethoxysilane and 10 parts of nanoporous silica (particle size 100 nm) to a reaction vessel, start stirring (500 rpm), heat to 20°C, and hold for 30 min to perform hydrophobic modification of the nanoporous silica; centrifuge at 10000 rpm for 10 min to remove the upper layer of heptadecafluorodecyltrimethoxysilane; then add 400 parts of soybean oil, 50 parts of oleic acid, and 30 parts of polyoxyethylene hydrogen. Mix castor oil CO-40, 30 parts of triglyceride monooleate, 40 parts of decaglyceride monooleate, and 6 parts of Evonik 740. Adjust the stirring speed in the reactor to 1000 rpm, heat to 30°C, and add water dropwise to 1000 parts (i.e., the sum of the mass parts of all raw materials is 1000 parts, the same below). The dropwise addition time is 30 minutes. After the dropwise addition is completed, keep warm for 30 minutes. The final water-in-oil emulsion is the high-performance release agent for self-cleaning, vibration-free concrete.

[0052] Example 2

[0053] This embodiment provides a method for preparing a high-performance release agent for self-cleaning, vibration-free concrete, the steps of which are as follows:

[0054] Add 30 parts of perfluorooctyltriethoxysilane and 15 parts of nanoporous silica (particle size 200nm) to a reactor, start stirring (500rpm), heat to 25℃, and keep warm for 30min to perform hydrophobic modification of nanoporous silica; centrifuge at 10000rpm for 10min to remove the upper hydrophobic modifier (i.e., perfluorooctyltriethoxysilane); then add 500 parts of corn oil, 70 parts of linolenic acid, 40 parts of triglyceride monooleate, 40 parts of decaglyceride monooleate, 40 parts of dodecylphenol polyoxyethylene ether, and 4 parts of Dongbang DF210, respectively. Adjust the stirring speed in the reactor to 1200rpm, heat to 40℃, and add the remaining water dropwise to 1000 parts over 45min. After the addition is complete, keep warm for 30min. The final oil-in-water emulsion is the high-performance release agent for self-cleaning, vibration-free concrete.

[0055] Example 3

[0056] This embodiment provides a method for preparing a high-performance release agent for self-cleaning, vibration-free concrete, the steps of which are as follows:

[0057] Add 40 parts of tridecafluorooctyltrimethoxysilane and 20 parts of nanoporous silica (particle size 100 nm) to a reactor, start stirring (500 rpm), heat to 30°C, and keep warm for 30 min to perform hydrophobic modification of the nanoporous material (i.e., nanoporous silica); centrifuge at 10000 rpm for 10 min to remove the upper hydrophobic modifier, then add 550 parts of rapeseed oil, 100 parts of isostearic acid, 50 parts of dodecylphenol polyoxyethylene ether, 50 parts of sorbitan monooleate, 50 parts of dehydrated sorbitan fatty acid ester, and 2 parts of BASF 1300, adjust the stirring speed in the reactor to 1500 rpm, heat to 35°C, add water dropwise to 1000 parts, add over 60 min, and keep warm for 30 min after the addition is complete. The final water-in-oil emulsion is the high-performance release agent for self-cleaning, vibration-free concrete.

[0058] Example 4

[0059] This embodiment provides a method for preparing a high-performance release agent for self-cleaning, vibration-free concrete, the steps of which are as follows:

[0060] Add 35 parts of hexadecyltrimethoxysilane and 10 parts of nanoporous silica (particle size 200 nm) to a reactor, start stirring (500 rpm), heat to 20°C, and keep warm for 30 min to perform hydrophobic modification of the nanoporous material (i.e., nanoporous silica); centrifuge at 10000 rpm for 10 min to remove the upper hydrophobic modifier; then add 450 parts of soybean oil, 60 parts of linoleic acid, 35 parts of polyoxyethylene hydrogenated castor oil CO-40, 35 parts of triglyceride monooleate, 50 parts of dehydrated sorbitol fatty acid ester, and 3 parts of BASF 1300, respectively. Adjust the stirring speed in the reactor to 1100 rpm, heat to 35°C, add water dropwise to 1000 parts over 35 min, and keep warm for 30 min after the addition is complete. The final oil-in-water emulsion is the high-performance release agent for self-cleaning, vibration-free concrete.

[0061] Example 5

[0062] This embodiment provides a method for preparing a high-performance release agent for self-cleaning, vibration-free concrete, the steps of which are as follows:

[0063] Add 35 parts of hexadecyltrimethoxysilane and 10 parts of nanoporous silica (particle size 150 nm) to a reactor, start stirring (500 rpm), heat to 25°C, and hold for 30 min to perform hydrophobic modification of the nanoporous material (i.e., nanoporous silica); centrifuge at 10000 rpm for 10 min to remove the upper hydrophobic modifier; then add 450 parts of corn oil, 60 parts of neodecanoic acid, 30 parts of dodecylphenol polyoxyethylene ether, 30 parts of decaglycerol monooleate, 40 parts of dehydrated sorbitol fatty acid ester, and 10 parts of BASF 1300, respectively. Adjust the stirring speed in the reactor to 1200 rpm, heat to 35°C, add water dropwise to 1000 parts over 35 min, and hold for 30 min after the addition is complete. The resulting oil-in-water emulsion is the high-performance release agent for self-cleaning, vibration-free concrete.

[0064] Example 6

[0065] This embodiment provides a method for preparing a high-performance release agent for self-cleaning, vibration-free concrete, the steps of which are as follows:

[0066] Add 35 parts of perfluorooctyltriethoxysilane and 10 parts of nanoporous silica (particle size 200 nm) to a reactor, start stirring (500 rpm), heat to 25°C, and hold for 30 min to perform hydrophobic modification of the nanoporous material (i.e., nanoporous silica); centrifuge at 10000 rpm for 10 min to remove the upper hydrophobic modifier; then add 500 parts of soybean oil, 80 parts of castor oil acid, 35 parts of dodecylphenol polyoxyethylene ether, 30 parts of polyoxyethylene hydrogenated castor oil CO-40, 45 parts of sorbitan monooleate, and 5 parts of Evonik 740, respectively. Adjust the stirring speed in the reactor to 1200 rpm, heat to 35°C, add water dropwise to 1000 parts over 35 min, and hold for 30 min after the addition is complete. The resulting oil-in-water emulsion is the high-performance release agent for self-cleaning, vibration-free concrete.

[0067] Comparative Example 1

[0068] Same as Example 1, except that no nanoporous silica was added, that is, the raw materials for preparing the release agent in this comparative example do not contain nanoporous materials.

[0069] Comparative Example 2

[0070] Same as Example 1, except that heptadecafluorodecyltrimethoxysilane was not added, that is, the raw materials for preparing the release agent in this comparative example do not contain hydrophobic modifiers.

[0071] Comparative Example 3

[0072] Same as Example 1, except that oleic acid was not added, that is, the raw materials for preparing the release agent in this comparative example do not contain bubble barrier agents.

[0073] Comparative Example 4

[0074] Same as Example 1, except that Evonik 740 was not added, that is, the raw materials for preparing the release agent in this comparative example do not contain defoamers.

[0075] Comparative Example 5

[0076] This embodiment provides a method for preparing a concrete release agent, the steps of which are as follows:

[0077] Add 20 parts of heptadecafluorodecyltrimethoxysilane and 10 parts of nanoporous silica (particle size 100 nm) to a reactor, start stirring (500 rpm), heat to 20°C, and keep warm for 30 min to perform hydrophobic modification of nanoporous silica; then add 400 parts of soybean oil, 50 parts of oleic acid, 30 parts of polyoxyethylene hydrogenated castor oil CO-40, 30 parts of triglyceride monooleate, 40 parts of decaglyceride monooleate, and 6 parts of Evonik 740, respectively. Adjust the stirring speed in the reactor to 1000 rpm, heat to 30°C, add water dropwise to 1000 parts, and add over 30 min. After the addition is complete, keep warm for 30 min. The final emulsion is the concrete release agent.

[0078] In this comparative example, after hydrophobic modification of nanoporous silica, no centrifugation was performed to remove the upper layer of hydrophobic modifier.

[0079] According to the standard JC / T949-2005 "Release Agents for Concrete Products", the amount of paste adhering to the formwork (adhesion amount) and the appearance of the specimens after demolding were measured after using the release agents of Examples 1-6 and Comparative Examples 1-5. The vibration time was 5 seconds. The results are shown in […]. Figures 1-4 And Table 1.

[0080] Table 1. Adhesion amount and appearance of specimens after demolding in Examples 1-6 and Comparative Examples 1-5

[0081] <![CDATA[Adhesion amount (g / m 2 )]]> Appearance of the specimen after demolding Example 1 0 Smooth surface, no color difference, and almost no bubbles. Example 2 0 Smooth surface, no color difference, and almost no bubbles. Example 3 0 Smooth surface, no color difference, and almost no bubbles. Example 4 0 Smooth surface, no color difference, and almost no bubbles. Example 5 0 Smooth surface, no color difference, and almost no bubbles. Example 6 0 Smooth surface, no color difference, and almost no bubbles. Comparative Example 1 1.9 The surface has a layer of dust, obvious color difference, and many bubbles. Comparative Example 2 2.5 The surface has some dust, no color difference, and almost no bubbles. Comparative Example 3 0.6 The surface has some dust, no color difference, and many small air bubbles. Comparative Example 4 0.4 The surface has loose dust, no color difference, and many large air bubbles. Comparative Example 5 3.2 The surface has a layer of dust, obvious color difference, and many bubbles.

[0082] Figure 1 The results show the surface slurry condition of the template after using the release agent from Examples 1-6. It can be seen that after the release agent from Examples 1-6 is applied to the steel template, the slurry hardens for 24 hours before demolding. There is no floating dust on the surface of the steel template, and the template can be reused without cleaning.

[0083] Figure 2 The images show the appearance of the specimens after demolding in Examples 1-6. It can be seen that the slurry was demolded after 24 hours of hardening. The surface of the hardened slurry was uniform in color and had almost no visible air bubbles.

[0084] Figure 3The results showed that after applying the release agent to the steel molds, the surface of the molds was covered with slurry of Comparative Examples 1-5. It was found that after the release agent was applied to the steel molds, the slurry hardened for 24 hours before demolding. Different degrees of dust appeared on the surface of the steel molds, and the molds needed to be cleaned before they could be used again.

[0085] Figure 4 The appearance of the specimens after demolding in Comparative Examples 1-5 shows that after demolding the slurry for 24 hours, there were different degrees of color difference and air bubbles on the surface of the hardened slurry, which seriously affected the overall appearance of the hardened slurry.

[0086] Tests conducted according to the JC / T949-2005 standard for "Release Agents for Concrete Products" demonstrate that the high-performance release agent of this invention achieves excellent release performance with only basic leveling and vibration time. Concrete released using this release agent exhibits a smooth surface, is virtually bubble-free, and the formwork can be reused without any further treatment.

[0087] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-performance release agent for self-cleaning, vibration-free concrete, characterized in that, The ingredients, by weight, include the following: 20-40 parts hydrophobic modifier, 10-20 parts nanoporous material, 50-100 parts bubble blocker, 400-550 parts base oil, 100-150 parts emulsifier, 2-10 parts defoamer, and 130-418 parts water. The hydrophobic modifier is selected from one of heptadecafluorodecyltrimethoxysilane, perfluorooctyltriethoxysilane, tridecafluorooctyltrimethoxysilane, and hexadecyltrimethoxysilane; The nanoporous material is selected from nano-silica with a particle size of 100-300nm. The bubble barrier agent is selected from one of oleic acid, linoleic acid, linolenic acid, ricinoleic acid, isostearic acid, and neodecanoic acid; The base oil is selected from one of soybean oil, rapeseed oil, and corn oil; The defoamer is selected from one of acetylenic diol defoamer and organosilicon defoamer; The emulsifier is selected from three of the following: polyoxyethylene hydrogenated castor oil CO-40, triglyceride monooleate, decaglyceride monooleate, dodecylphenol polyoxyethylene ether, sorbitan monooleate, and dehydrated sorbitol fatty acid ester. The preparation method of the self-cleaning, vibration-free high-performance release agent for concrete includes the following steps: Accurately weigh each raw material according to the mass fraction, mix the hydrophobic modifier and nanoporous material, stir for the first time, heat to 20-30℃, keep warm, centrifuge, add base oil, bubble blocker, emulsifier and defoamer, stir for the second time, heat to 30-40℃, add water, keep warm, and obtain an oil-in-water emulsion, which is the self-cleaning non-vibrating concrete high-performance release agent. The stirring speed for the first stirring was 500 rpm; The centrifugation speed was 10,000 rpm and the time was 10 min; The second stirring speed is 1000-1500 rpm.

2. A method for preparing a high-performance release agent for self-cleaning, vibration-free concrete as described in claim 1, characterized in that, Includes the following steps: Accurately weigh each raw material according to the mass fraction, mix the hydrophobic modifier and nanoporous material, stir for the first time, heat to 20-30℃, keep warm, centrifuge, add base oil, bubble blocker, emulsifier and defoamer, stir for the second time, heat to 30-40℃, add water, keep warm, and obtain an oil-in-water emulsion, which is the self-cleaning non-vibrating concrete high-performance release agent.

3. The preparation method of the high-performance release agent for self-cleaning, vibration-free concrete according to claim 2, characterized in that, The two heat preservation times were both 30 minutes.

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